Pontifical Catholic University of Puerto Rico, Ponce March 5, 2016

51st ACS Junior Technical Meeting 36th Puerto Rico Interdisciplinary Scientific Meeting (PRISM)

SPONSORED BY

American Chemical Society – Puerto Rico Section Puerto Rico Louis Stokes Alliance for Minority Participation Resource Center for Science and Engineering, UPR Central Administration Pontifical Catholic University of Puerto Rico 3

51st ACS Junior Technical Meeting 36th Puerto Rico Interdisciplinary Scientific Meeting (PRISM) Pontifical Catholic University of Puerto Rico, Ponce March 5, 2016

TABLE OF CONTENTS

Map of the Pontifical Catholic University of Puerto Rico, Ponce ...... 5 Organizing And Scientific Committees ...... 7 Invited Speaker ...... 9 Program Agenda ...... 11

Oral Sessions ...... 13 Agricultural Sciences ...... 15 Astronomy ...... 21 Chemistry ...... 25 Computer Science ...... 121 Electronics ...... 129 Engineering ...... 135 Environmental Sciences ...... 173 General Sciences ...... 205 Geosciences ...... 213 Industrial Pharmacy ...... 217 Life/Biological Sciences ...... 221 Mathematics ...... 317 Pharmaceutical Sciences ...... 325 Physics ...... 331

Poster Session ...... 339 Chemistry ...... 341 Engineering ...... 363 Environmental Sciences ...... 373 General Sciences ...... 388 Geosciences ...... 392 Life/Biological Sciences ...... 398 Mathematics ...... 428 Physics ...... 432

Map of the Pontifical Catholic University of Puerto Rico, Ponce

51st ACS Junior Technical Meeting 36th Puerto Rico Interdisciplinary Scientific Meeting (PRISM) Pontifical Catholic University of Puerto Rico, Ponce March 5, 2016 Organizing and Scientific Committees

Puerto Rico Local Section American Chemical Society Officers 2016

Chair Dr. Brenda J. Ramos Past Chair Dr. Edmy J. Ferrer Chair Elect Dr. José Ramírez Secretary Ms. Stephanie Chaparro Treasurer Dr. Jorge L. Colón Northeastern Representative Ms. Sara M. Delgado Southwestern Representative Dr. Nilka M. Rivera Counselor Dr. Néstor Carballeira Counselor Dr. Agnes Costa Counselor Dr. Ángela M. González Counselor Ms. Myrna Otaño Alternate Counselor Dr. Jorge L. Colón Alternate Counselor Dr. Carlos Ruiz Alternate Counselor Mr. Orlando J. Morales Alternate Counselor Ms. Bárbara Casañas Director at Large Dra. Ingrid Montes

PCUPR-College of Science Research and JTM/PRISM Committee

President Dr. Jorge Iván Vélez Arocho Dean, College of Science Dr. Alma Santiago Committee President Dr. Zaira Mateo Biology Department Representative Dr. Sandra Molina Chemistry Department Representative Dr. Margarita Rodríguez Prof. Javier Carrasquillo Dr. Carmen Velázquez de Collazo Dr. Monica Marie Arroyo Math & Physics Department Prof. Jorge López Representative Nursing Department Representative Dr. Zulma Torres Psychology Department Representative Dr. Luis Cañals Collaborators and Special Thanks Ms. Daisy Morales Ms. Carmen Gómez Ms. Lourdes M. Matos Mr. Julio Palmer Ms. Rosita Archevald Mr. Melvin Maldonado Physical Plant Personnel 8

RCSE

Acting Director Dr. Frederick A. Just-Agosto Associate Director Dr. María Vargas-Capriles Special Assistant Ing. José A. Muñoz-Álvarez Admin. Assistant Mr. Héctor R. Méndez-Rubio

PR-LSAMP

Co-PI Dr. Antonio Martinez-Collazo Academic Coordinator Prof. Javier Figueroa Santiago Magement Coordinator Ms. Zulma I. Crespo-Figueroa

UPR-Central Administration

UPR President/PR-LSAMP PI Dr. Uroyoán Walker-Ramos Vice President for Research Dr. José A. Lasalde-Dominici and Technology Associate Vice President for Dr. Gladys Escalona de Motta Research and Technology

51st ACS Junior Technical Meeting 36th Puerto Rico Interdisciplinary Scientific Meeting (PRISM) Pontifical Catholic University of Puerto Rico, Ponce March 5, 2016

INVITED SPEAKER

Dr. Giovanna Guerrero-Medina Director, Yale Ciencia Initiative Associate Research Scientist for the Center for Scientific Teaching, Department of Molecular and Cell Biology at Yale University, New Haven, Connecticut

Ciencia Puerto Rico: Improving STEM Education and Careers through a Network for Puerto Rican Science

SHORT BIO Dr. Giovanna Guerrero-Medina, is the Executive Director of Ciencia Puerto Rico, an international network of scientists, students and educators committed to promoting scientific outreach, education and careers among Puerto Ricans and Latinos. She is also Director of the Yale Ciencia Initiative in the Center for Teaching and Learning at Yale University, where she studies the impact of scientific networks like Ciencia Puerto Rico in improving access and participation in science. Under her leadership, CienciaPR has become one of the largest networked communities of Hispanic scientists in the world, has secured several large grants to support diversity in science education and career development, and in 2015 received recognition as a Bright Spot in science education by the White House. Prior to her current position, Dr. Guerrero-Medina was Head of Science Policy at the Van Andel Research Institute in Grand Rapids, MI and a Health Science Policy Analyst at the National Institutes of Health. Dr. Guerrero-Medina has a Ph.D. in Molecular and Cell Biology, University of California, Berkeley and a B.A. in Biology from the University of Puerto Rico, Rio Piedras.

ABSTRACT

Science, technology, engineering, and math (STEM) are essential for countries and individuals in the 21st century and open doors to some of the fastest growing, most rewarding, and best paying careers. Unfortunately, many students do not pursue these disciplines because they don’t see the relevance of these fields to their lives, because they lack role models they can identify with, or because they don’t have access to mentors or resources that can facilitate training opportunities and help them navigate the ups and downs of a career in these fields. STEM professionals can play a crucial role in helping to improve science education resources, experiences and trajectories of students interested in these careers. Since 2006, Ciencia Puerto Rico (CienciaPR, http://www.cienciapr.org) has helped connect the geographically dispersed Puerto Rican scientific community for the promotion of science education and scientific careers. Today, more than 7,300 STEM professionals, students and educators are members of CienciaPR. Through their example, contributions, and connections, CienciaPR has increased the visibility of STEM role models, improved science communication and educational resources in Puerto Rico, and facilitated access to academic and professional advice, resources and opportunities for students and young scientists. This presentation will provide an overview of CienciaPR's emergence and achievements and give concrete examples of how young scholars can explore their academic and career options through CienciaPR, as well as contribute themselves to impact others through their own knowledge and example. 11 51st ACS JUNIOR TECHNICAL MEETING 36th PUERTO RICO INTERDISCIPLINARY SCIENTIFIC CONFERENCE (PRISM) PONTIFICAL CATOLIC UNIVERSITY OF PUERTO RICO, PONCE CAMPUS MARCH 5, 2016 PROGRAM AGENDA 7:30 am – 9:30 am Registration Vicente Murga Theater, Lobby 7:30 am – 9:00 am Breakfast In front of Vicente Murga Theater, Left side (opposite of the parking lot) 9:00am – 9:30 am Vicente Murga Theater, Pontifical Catholic University Master of Ceremony of Puerto Rico  Prof. Javier Carrasquillo Chemistry Department Pontifical Catholic University of Puerto Rico

Invocation  Dr. Margarita Rodríguez Chemistry Department Pontifical Catholic University of Puerto Rico

Welcome Remarks  Dr. Jorge I. Veléz Arocho, President Pontifical Catholic University of Puerto Rico

 Dr. José A. Lasalde, Vice-President Research and Technology University of Puerto Rico

 Dr. Frederick Just-Agosto, Acting Director Resource Center for Science and Engineering

 Dr. Alma Santiago, Dean of the College of Science Pontifical Catholic University of Puerto Rico

 Dr. Antonio Martínez Collazo, Co-PI PR-LSAMP University of Puerto Rico

 Dr. Brenda Ramos, President American Chemical Society - Puerto Rico Section University of Puerto Rico, Aguadilla

9:30 am – 9:45 am Presentation of Plenary Speaker  Dr. Braulio D. Jiménez Department of Biochemistry Medical Science Campus, University of Puerto Rico

9:45 am – 10:45am PLENARY CONFERENCE  Dr. Giovanna Guerrero-Medina, Associate Research Scientist Yale University

11:00 am - 12:00 pm Concurrent Scientific Sessions McManus Building, Perea Building, Student Center and Mother Teresa Hall 12:00 pm – 1:30 pm Lunch Outdoor Vicente Murga Theater, Left side (opposite to the parking lot) 1:40pm – 4:00pm Concurrent Scientific Sessions McManus Building, Perea Building, Student Center and Mother Teresa Hall 8:00am - 3:00pm Poster Set Up Perea Building Lobby (1st Floor)

3:00pm – 5:00pm Poster Session Perea Building Lobby (1st Floor)

51st ACS Junior Technical Meeting 36th Puerto Rico Interdisciplinary Scientific Meeting (PRISM)

Oral Sessions

(Arranged in Alphabetical order by field and presenter´s last name)

● Agricultural Sciences

● Astronomy

● Chemistry

● Computer Sciences

● Electronics

● Engineering

● Environmental Sciences

● General Sciences

● Geosciences

● Industrial Pharmacy

● Life/Biological Sciences

● Mathematics

● Pharmaceutical Sciences

● Physics

Agricultural Sciences

Agricultural Sciences Presenter: Colon Carion, Nicole M.

Mentor: Lozada, Chad

Title: Fungal Contamination in Rice Grains

Authors: Nicole Colon Carrion (UPR-Cayey), Chad Lozada (UPR-Cayey)

Abstract

Rice represents around 75% of our daily diet. Crops and stored grains are susceptible to various pathogens that represent a threat to our health. The study presented herein compares the normal fungal microflora and the endophytic fungal microflora present on white and brown rice grains. 100 samples of commercially sold rice were analyzed for fungal contamination. Grains were isolated in SDA media, and purified in PDA; macroscopical and microscopical characterization were performed followed by the amplification of ITS region using PCR. Analysis of normal fungal microflora germination indicated a 10% of germination in sterilized regular rice grains, and 44% in brown rice. A decrease in fungal growth was observed when analyzing the germination on endophytic fungi: 6% on regular grains and 8% in brown rice. In addition, a higher fungal diversity was found on brown rice grains compared to white rice. This variation may be due to differences in the processing methods used for each rice grain type. Pesticides and preservatives used for fungal growth control often reduce the number of endophytic fungi within the grains. Blast analysis revealed the presence of toxigenic strains Aspergillus flavus and Penicillium viridicatum. The study of fungal growth in rice grains can contribute to the minimization of mycotoxin production by its prevention and control; therefore decreasing crop contamination and human exposure.

Agricultural Sciences Presenter: Plaza Torres, Stephanie M.

Mentor: Feliciano Rivera, Merari

Title: High-throughput screening and characterization of fungi attacking the staple crop Dioscorea rotundata

Authors: Stephanie Plaza-torres (University of Puerto Rico, Mayagüez Campus), Merari Feliciano- rivera (University of Puerto Rico, Mayagüez Campus)

Abstract

Colletotrichum is an ascomycete that contains numerous pathogenic species that attack important crops worldwide. Currently, there is a crucial dilemma with the taxonomy and nomenclature of these fungal species due to incomplete genetic data, variation of host specificity, high similarity and variability of morphological traits, and high similarity between species when using ITS (fungi barcode gene) sequences. This study aims to explore alternatives to these methods and find new means to characterize these fungi in a quick and reliable way. Nine foliage samples were collected from Dioscorea rotundata cv. Guinea plants located at the UPRM'S Agricultural Research Station at Isabela, P.R. and their symptomatic tissues described. A total of twenty-one lesions were observed, prepared by superficial sterilization, and later cultured in PDAa media to stimulate fungal growth and inhibit bacteria. Afterwards, the main objective was isolating all the pathogens found in the tissues cultured to successfully separate each fungi from each other. Following Koch's Postulates, each different fungus observed in the tissue isolates was cultured in individual PDA plates to purify each fungus. A total of two hundred and sixty-one isolates were obtained, from these less than 2% were not pure and approximately 20% are estimated to be Colletotrichum based on preliminary screenings. These, will be identified using various methods like pathogenicity tests and morphology, but the primary focus will reside in the genetic characterization, were novel methods will be employed using restriction endonucleases and other genetic regions beside ITS.

Agricultural Sciences Presenter: Torres Caraballo, Jennifer

Mentor: Berrios Villarini, Rosa

Title: Micropropagation of Olea europaea L. (olive) in Puerto Rico

Authors: Jennifer Torres Caraballo (Pontifical Catholic University of Puerto Rico)

Abstract

Olive trees are very important in the food and health industry especially in the Mediterranean. Studies have shown that ninety-five percent of the world's olive trees are grown in this region. These trees are constantly being attacked by disease caused by fungi, bacteria and pest like Spilocaea oleagina, Xylella fastidiousa and Bactrocera oleae. The goal of this investigation is to obtain Olive (Olea europaea L.) disease-free tissues, to proceed with micropropagation and distribute to interested horticultural growers in Puerto Rico.

Two trials with different disinfection concentration and three media formulation were attempted with a total of nineteen explants. The media formulation used in this study were Rugini Olive Medium supplemented with 50 ml l-1 of Coconut water, 0.50 mg l-1 of BAP, 30 g l-1 of D-mannitol and 6.5 g l-1 of agar powder. The second media was Lloyd & McCown's Woody Plant Basal Medium supplemented with 19

0.50 mg l-1 of Zeatin, 3 g l-1 of activated charcoal, 30 g l-1 of D-mannitol and 6.5 g l-1 of agar powder. The third media was Lloyd & McCown's Woody Plant Basal Medium supplemented with 0.50 mg l-1 of Zeatin, 3 g l-1 of activated charcoal, 0.025 mg l-1 of Biotin, 0.25 mg l-1 of Folic acid, 30 g l-1 of D- mannitol and 6.5 g l-1 of agar powder. The media formulation that proved to be more effective in the growth of the explants within five days was Rugini Olive Medium, supplemented with 50 ml/lt Coconut water, 0.50 mg l-1 BAP, 30 g l-1 D-mannitol and 6.5 g l-1 of agar powder. Shootlets were regenerated from nodal explants of stem through auxiliary shoot proliferation.

Three additional disinfection treatments with a total of thirty-four explants tissues were tested with Rugini Olive Medium. The most effective treatment was 20% Sodium Hypochlorite and 70% Isopropyl alcohol, from fourteen explants were recovered 71% tissues free of contamination. Micropropagation protocols will follow.

Agricultural Sciences Presenter: Torres Rodríguez, Janmarys

Mentor: Berrios Villarini, Rosa

Title: Micropropagation of Mentha piperita In Puerto Rico

Authors: Janmarys Torres Rodríguez (Pontifical Catholic University of Puerto Rico)

Abstract

Mint species are of major importance in the organic food and health industry. This study aims for the micropropagation of Mentha piperita for horticultural and medicinal purpose. Three trials with two disinfection treatments were tested with twenty tissues. Each trial was incubated at 23-25?C, 50-70% RH and an approximate light intensity of 3000 lux. The first treatment consisted in sterile 70% isopropyl alcohol for one minute followed by 20% Sodium hypochlorite and Tween 20 for twenty minute and the second treatment consisted in 17% Sodium hypochlorite and Tween 20 for one minute followed by three distilled water rinses. The media formulation consisted of Murashige and Skoog (1962) basal salt containing the growing hormones 0.5 mg/l naphthaleneacetic Acid (NAA) and 0.5 mg/l 6- benziladenine (BA) and 0.7% agar powder. Shootlets were regenerated from nodal explants of stem through auxiliary shoot proliferation. The most effective disinfection treatment was 17% Sodium hypochlorite and Tween 20 which showed a recovery of sixty eight percent in comparison with thirty five percent of the 70% isopropyl alcohol followed by 20% Sodium hypochlorite and Tween 20 treatment. Nodal tissue presented shoot proliferation after five days incubation at 25+-2C, 50-60% RH and 3000 lux. Micropropagation protocols will follow

Agricultural Sciences Presenter: Valero David, Guillermo E.

Mentor: Rivera-Vargas, Lydia I.

Title: Foliar and Inflorescences Pathogens of "Recao" (Eryngium foetidum L.)

Authors: Guillermo E. Valero David (University of Puerto Rico, Mayagüez Campus), Lydia I. Rivera- vargas (University of Puerto Rico, Mayagüez Campus)

Abstract

Foliar and Inflorescences Pathogens of "Recao" (Eryngium foetidum L.)

Guillermo E. Valero David, Lydia I. Rivera-Vargas, Department of Agro-Environmental Sciences,

University of Puerto Rico, College of Agricultural Sciences, Mayagüez Campus, Mayagüez Puerto Rico.

Abstract: In America and the Caribbean, Eryngium foetidum L. best known as "recao" or "culantro", is one of the most common aromatic herb used in the daily cuisine. In Puerto Rico, E. foetidum production had a market value of $543,000 from 2013 to 2014. Foliar and inflorescences symptoms are often observed in E. foetidum plants and have been associated with pathogens, but very limited studies had been conducted to identify and characterize them. Thus the purpose of this research was to conduct a wider study of pathogens affecting foliage and inflorescences of E. foetidum. Symptomatic tissue was collected at various locations: UPR Agricultural Research Station at Gurabo, P.R. and at local markets. Tissue was disinfected and placed on to acidified Potato Dextrose Agar (PDA) and Trypticase Soy Agar (TSA) for fungal and bacterial isolation, respectively. Plates were incubated at 26ºC and colonies were purified for identification and characterization. In vitro pathogenicity tests were conducted on healthy detached leaves of E. foetidum for 40 fungal isolates and 11 bacterial isolates under controlled laboratory conditions at 25ºC. Tissues suspicious of viral infections were analyzed using "immunostrips" and ELISA tests for Cucumber Mosaic Virus (CMV) and potyvirus, respectively. None of the bacterial isolates tested were pathogenic. Of 40 fungal isolates, 45% were pathogenic on detached leaves. Pathogenic fungi were identified using morphology and taxonomic keys. Six fungal genera were identified: Alternaria spp., Colletotrichum spp., Curvularia spp., Fusarium spp., Nigrospora spp., Stemphylium spp. All tests for virus detection were negative. Pathogenicity tests in planta will confirm our findings. Fungal molecular characterization is in progress to provide a more robust and accurate diagnostic.

Keywords: Apiaceae, recao, culantro, ELISA, Potyvirus, CMV, Fungi, Bacteria 21

Astronomy

Astronomy Presenter: Del Valle Rodríguez, Yashira Marie

Mentor: Muller, Rafael

Title: Position Angle and Separation of Binary Stars Selected from the Washington Double Star Catalog

Authors: Juan C. Cersocimo (University of Puerto Rico-Humacao), Raphael Muller Porrata (University of Puerto Rico-Humacao), Yashira M. Del Valle Rodriguez (University of Puerto Rico-Humacao), Gabriela Lynnette Espinosa Rodriguez (University of Puerto Rico- Humacao), Marjory Reyes (University of Puerto Rico-Humacao), Nelson Vergara (University of Puerto Rico-Humacao)

Abstract

We use binaries stars system to calculate the position angle and separation to update the data of the "Washington double star catalog'. Using the 31 inch NURO telescope at Anderson Mesa near Flagstaff, Arizona to take our main data. A CCD camera coupled to the NURO telescope allows for a simple and straightforward procedure for obtaining the images of the binaries. Analysis of the images is straightforward and both direct and software methodology yield the separation and position angle of the binary stars. Using Pythagoras system we do the measurements of both position angle and separation of the binaries system. The data obtained is suitable for insertion in the Washington Double Star Catalog of the US Naval Observatory.

Astronomy Presenter: Lopez Oquendo, Andy J.

Mentor: Muller, Rafael

Title: Determine the distance of Binary Stars based on distance module

Authors: Andy Lopez Oquendo (University of Puerto Rico at Humacao), Juan C. Cersosimo (University of Puerto Rico at Humacao), Rafael Muller (University of Puerto Rico at Humacao)

Abstract

Distances of binary stars are an important parameter to measure in astrophysics. This measurement is not given in the stars catalogues. The Washington Double Star catalogue (WDS) is the world's principal database of astrometric double and multiple star information. Because we are taken separation of 24

double star using a small telescope (NURO 31 inch), the aim of this research is to compute distances of the systems by using the spectral type data provided by the catalogue. From the spectral data of the primary star we derive the absolute magnitude and then using the "distance module" to compute the distance for each system. To measure absolute magnitude (Mabs) we use H-R diagram and also we obtain the galactic coordinates by using the NASA/IPAC Extragalactic Database. As a result we present distance measurement of about thirty binary star which were observed by the team of the Humacao University Observatory selected form WDS catalogue. The distances of binary stars were found between ~3 and ~1000 pc, with an estimated error of 35%. As a future work our results will allow to measure the real separation of the binary systems.

Astronomy Presenter: Reyes, Marjory

Mentor: Muller, Rafael

Title: Separation

Authors: Marjory Reyes (Physics), Rafael J. Muller (Physics), Juan C. Cersosimo (Physics), Gabriela L. Espinosa (Physics), Yashira M. Del Valle (Physics), Nelson E. Vergara (Physics)

Abstract

We report on a sample of the data acquired on may 2012 at the 31 inch NURO telescope at Anderson Mesa nearby Flagstaff, Arizona pertaining the separation and position angle of selected binary stars. A CCD camera coupled to the NURO telescope allows for a simple and straightforward procedure for obtaining the images of the binary star system. Analysis of the images is straightforward and both direct and software methodology yield the separation and position angle of the binary stars. The data obtained is suitable for insertion in the Washington Double Star Catalog of the US Naval Observatory.

Chemistry

Chemistry Presenter: Adorno, Cindy

Mentor: Carballeira, Néstor

Title: Recent developments the first total synthesis of 2R,5Z,9Z,13Z-2- methoxyoctadecatrienoic acid isolated from the Caribbean sponge Asteropus niger

Authors: Cindy J. Adorno Rivera (Universidad de Puerto Rico Recinto de Río Piedras), Denisse Alequín Torres (Universidad de Puerto Rico Recinto de Río Piedras), Néstor M. Carballeira (Universidad de Puerto Rico Recinto de Río Piedras)

Abstract

Natural products have been the source of new structural entities having potential pharmacological activities. In addition, these novel structures are a motivation to develop new synthetic strategies for their construction. The ?-methoxylated fatty acids are rare in nature and have principally been identified in the phospholipids of sponges. Our group recently identified the novel 2R,5Z,9Z,13Z-2- methoxyoctadecatrienoic acid (1) with a relative abundance of less than 1% in the Caribbean sponge Asteropus niger. Acid 1 is new in nature and could display interesting biological activities for its polyunsaturation pattern. Our approach in this work is to synthesize 1 in order to examine its biomedical properties and confirm the proposed structure. Our progress towards the first total synthesis of 1 from 1,5-decadiyne will be presented.

[1] Saikia, B., Devi, T. J., Barua, N. C. Org. Biomol. Chem. 2013, 11, 905-913.

[2] Bugni, T.S., Richards, B., Bhoite, L., Cimbora, H., Harper, M. K., Ireland, C. M. J. Nat Prod. 2008, 71,1095

Chemistry Presenter: Adorno Rivera, Linet E.

Mentor: Diaz-Vazquez, Liz

Title: Biosynthesis of Gold Nanoparticles Using Osmundaria Obtusiloba Extract and their Potential Use in Optical Sensing Applications.

Authors: Arnulfo Rojas (UPR-RP), Linet Adorno (UPR-RP), Maria Del Mar Cordero (UPR-RP), Zoar Mercado (UPR-RP), Alexander Rodriguez (UPR-RP), Liz Díaz (UPR-RP) 28

Abstract

The optical properties of gold nanoparticles depend on particles size, shape, protective ligand and the synthesis method used for their production. The present study describes an eco-friendly method for the synthesis of gold nanoparticles (AuNPs) the macroalgae Osmundaria Obtusiloba. The optical properties of the obtained nanoparticles and whether the use of the macroalgae extract confers them with additional properties were evaluated and compared with NPs obtained via traditional methods. The formation of AuNPs was confirmed by the presence of an absorption peak at 540 nm using UV-VIS spectrophotometry and was observed within 10 min. Au NPs were physical and chemically characterized by FTIR, TEM, SEM-EDS, XRD. TEM images reveled several shapes including spherical, triangular and diamond shaped nanoparticles with size ranges between 10 to 20 nm. XRD pattern confirmed that nanoparticles have a face centered cubic (fcc) crystalline structure. The presence of 83.58 %wt. of elemental gold in the obtained nanoparticles was confirmed by EDS. As well the utility of the generated gold nanoparticles for fluorescence was evaluated using methyl orange.

Chemistry Presenter: Alsina Sanchez, Ambar M.

Mentor: Montes, Ingrid

Title: Synthesis of Ferrocenyl Chalcones containing heterocyclic moieties as potential antimalarial agents

Authors: Ambar M. Alsina Sanchez (University of Puerto Rico Rio Piedras Campus), Sara M. Delgado Rivera (University of Puerto Rico Rio Piedras Campus), Jesus Muniz Oliver, Ms (University of Puerto Rico Medical Sciences Campus), Emilee Colon Lorenzo, Phd (University of Puerto Rico Medical Sciences Campus), Adelfa E. Serrano, Phd (University of Puerto Rico Medical Sciences Campus), Ana R. Guadalupe Quinones, Phd (University of Puerto Rico Rio Piedras Campus)

Abstract

Malaria remains one of the most devastating diseases in the world. On a yearly basis, approximately 600,000 million people are infected and around a million die because of this disease. One of the major problems is that parasites have developed resistance to the drugs that are currently available in the market. Therefore, there is an increasing need to find new anti-malarial agents. Chalcones and their heterocyclic derivatives are among the natural products that have shown a wide range of biological activities, including promising antimalarial drug potential. It has been studied that replacing one of the aromatic rings of a chalcone for a ferrocenyl group results in activity enhancement, possibly due to the lipophilicity of the ferrocenyl group and bioavailability. Moreover, according to the literature, the presence of aromatic heterocycles moieties in the molecule's scaffold improves their potential as antimalarial active compounds. Therefore, we expect that ferrocenyl chalcones based scaffolds 29

containing heterocyclic core will exhibit enhanced antimalarial activity. Ferrocenyl chalcones with an array of heterocyclic substituents were synthesized by a base catalyzed Claisen-Schmidt reaction using a solvent-free approach. Products with good yields and high purity have been obtained. This purity has been confirmed via 1H-NMR and 13C-NMR spectroscopy as well as melting point range determinations. The methodology and characterization will be elaborated. This research is supported by MARC grant 2T34GM007821-36.

Chemistry Presenter: Alvarado Aguilar, Abrahan J.

Mentor: González González, Ileana

Title: Pt-Urease Nanodisc for a Self-Sustainable Urea Bio Device

Authors: Ileana González González (Universidad del Turabo), Abrahán J Alvarado Aguilar (Universidad del Turabo)

Abstract

Kidneys remove waste by-products of metabolism in the body, such as urea. Urea buildup can occur because of kidney failure, causing various medical conditions such as fluid retention, fatigue, insomnia, among others. Our research is focused on creating a bio device that is able to break down urea in a complex matrix, such as blood. For this, we suggest the use of a urease nanodisc, which is a membrane like structure that protects the enzyme from degradation. Our aim is to break down urea into ammonia, and then oxidize it into nitrogen using Pt nanoparticles embedded into the nanodisc membrane interface. We carried out the synthesis of two types of nanodiscs (NDP and NDM) using a membrane scaffold protein, two different types of membrane lipids and Jack Bean urease in a 0.1 M PBS buffer at 7.4 pH. We tested the activity of the urease using a Urease Activity Assay Kit and used the Berthelot method to determine the urease units per L, obtaining 23.9 units/L for the NDP sample and 23.7 units/L for the NDM sample. Dynamic Light Scattering (DLS) was used to obtain the hydrodynamic size in the PBS solution in which we were able to find particles of around the 12-15nm range which correspond to the nanodisc size. Atomic Force Microscopy (AFM) was used to image the topography of the surface of the nanodiscs. Cyclic Voltammetry was used to determine the amount of ammonia formed thanks to the breakdown of a urea solution of 0.1 M. In conclusion, we were able to image the topography and obtain the size of the urease nanodiscs, while confirming the urease activity with electrochemical methods and a urease activity assay kit.

Chemistry Presenter: Alvarez Benedicto, Ester

Mentor: Carballeira, Nestor

Title: Total Synthesis of 10-Cyclohexyl-6-decynoic Acid for Biomedical Applications

Authors: Alvarez Benedicto, Ester (Universidad de Puerto Rico, Recinto de Rio Piedras), Morales Guzman, Christian (Universidad de Puerto Rico, Recinto de Rio Piedras), Rodriguez Betancourt, Leonel (Universidad de Puerto Rico, Recinto de Rio Piedras), Carballeira, Nestor M. (Universidad de Puerto Rico, Recinto de Rio Piedras)

Abstract

Álvarez Benedicto, Ester1; Morales Guzmán, Christian1; Rodríguez Betancourt, Leonel1; Carballeira, Néstor M.1

1Department of Chemistry, University of Puerto Rico, Río Piedras Campus, P.O. Box 23346, San Juan, Puerto Rico 00931-3346.

Keywords: Biochemistry, Biomedical, Organic Chemistry

Acetylenic fatty acids have been recognized by their potential biological activities. Specifically, ?6 alkynoic fatty acids are known to possess antifungal, antimicrobial and antileishmanial activity1,2,3. Fatty acids containing double or triple bonds are characterized by their efficiency towards fungal pathogens such as C. albicans and A. fumigatus4. The location of the unsaturation and the chain length of these acids have been associated with their biological properties3,4. The 10-cyclohexyldec-6-ynoic acid (1) was synthesized in 5 steps and in 30% overall yield in order to study the effect of the rigidity of the chain, caused by the cyclohexyl substituent, in its biological properties. The complete synthesis of 1 and the preliminary bioassay results will be presented.

References:

1. Gershon, H., et. al. Antifungal Properties of 2-Alkynoic Acids and their Methyl Esters. Can. J. Microbiol. 1978, 24, 593-597.

2. Carballeira, N. M., et. al. 2,6-Hexadecadiynoic Acid and 2,6-Nonadecadiynoic Acid: Novel Synthesized Acetylenic Fatty Acids as Potent Antifungal Agents. Lipids. 2006, 41, 507-511.

3. Carballeira, N. M., et. al. Total Synthesis and Antileishmanial Activity of the Natural Occurring Acetylenic Fatty Acids 6-Heptadecynoic Acid and 6-Icosynoic Acid, Lipids. 2009, 44,953-961.

4. Li, X., et. al. Potent In Vitro Antifungal Activities of Naturally Occurring Acetylenic Acids, Antimicrob. Agents Chemother. 2008, 52, 24

Chemistry Presenters: Aponte Jimenez, Genesis Rivera Perales, Carolina

Mentor: Alegria, Antonio E

Title: Photosensitized oxidation of N-nitroso-N-cyclohexyl-hydroxylamine.

Authors: Génesis Aponte Jiménez (UPR-Humacao)

Abstract

It has been found that nitric oxide (NO) is a hypoxic radiosensitizer in the radiotherapy of tumors. Also, at near micromolar concentrations nitric oxide from extracellular sources induces apoptosis and tumor cell death by several mechanisms. NO is also used in many biomedical applications. Furthermore, NO is a wound healing promoting agent and due to its antibacterial activity it is a promising agent for reducing implant-associated infections and promoting tissue regeneration in orthopedic procedures. However, it's usefulness is limited by its short half-life, instability during storage, and potential toxicity, including it's influence on the systemic blood pressure. Thus, the selective delivery of NO to tissues in adequate concentrations is a present and needed area of research. The ultimate purpose of this project is the development of a selective tool to deliver NO and possibly other reactive oxygen and reactive nitrogen species (ROS and RNS, respectively) using photosensitization. We have prepared N-nitroso-N-cyclohexyl- hydroxylamine for the selective production of NO. We have found that this compound releases NO if photosensitized by the red-light-absorbing dye aluminum phthalocyanine tetrasulfonate (AlPcS4). Evidence has been obtained which supports a photosensitized oxidation pathway for this release.

Besides, this project was designed to develop the use of N-nitroso-N-cyclohexyl-hydroxylamine (NNCH) for the selective production of nitric oxide (NO). NNCH was synthesized using N-cyclohexyl- hydroxylamine (NCH). I use the recrystallization technique to purify and eliminate the impurities of the compound. N -Hexane was chosen as the ideal solvent to carry out the recrystallization of NNCH. To confirm the purity of the compound I obtain the Melting Point. The melting point was performed with the purpose to determine the identity of the NNCH. I characterized the compound using NMR of protons, NMR of carbon 13 and IR. The infrared (IR) technique allowed us to know the functional groups present in the NNCH by bands. These bands occurred due to vibrations and rotations atoms. Also, NNCH can produce NO while the photoirradation in N_2. The obtained results indicate that photoirradation in N_2 in 675nM of an anaerobic solution that contain NNCH, Carboxy-PTIO, Phosphate Buffer pH 7.4 and AlPcS4 produced NO from the derivated Carboxy-PTI in the EPR spectrum. This result indicates that NO in presence of NNCH reacts with Carboxy-PTIO producing Carboxy-PTI. Meanwhile, the photoirradation in N_2 in 675nM of an anaerobic solution containing NNCH, Phosphate Buffer (pH 7.4), AlPcS4 and less concentration of the previous sample of the Carboxy-PTIO produced NO from the derivated Carboxy-PTI in a greater quantity. The EPR spectrum allow us to see the compound's signals as the molecules dissociates because of the effect of light NNCH is constituted for the production of NO to obtain a better stability. 32

As part of the investigation, we want to know whether the presence of UBQ-0 makes more efficient the photoexcitation of the compound. In addition, it will be determined the amount of Carboxy-PTI in the presence and absence of the UBQ-0. The analysis will be done in an EPR spectrum. The reaction is carried out it is reversible and this indicates that there may be a transfer of electrons from products to reactants and vice versa.

Chemistry Presenter: Aponte Ortiz, Christian M.

Mentor: Colon, Jorge

Title: Intercalation of Curcumin into Zirconium Phosphate Nanoparticles as an Anti-Cancer Drug Delivery System

Authors: Christian Miguel Aponte Ortiz (Department of Chemistry, UPR-Rio Piedras Campus), Julissa R. González Villegas (Department of Chemistry, UPR-Rio Piedras Campus), Jorge L. Colón (Department of Chemistry, UPR-Rio Piedras Campus)

Abstract

Cancer is the second leading cause of death in the United States, accounting for 22 percent of all deaths. Different chemotherapeutic approaches have been developed in order to treat cancer patients. During the last decades curcumin has turned into a scientific spotlight due to its anti-oxidant, anti- inflammatory, and anti-cancer properties. Curcumin has shown anti-proliferative effect in multiple cancers and its action mechanism consists on the inhibition of the transcription factor NF-kB and downstream gene products (including c-myc, Bcl-2, COX-2, NOS, Cyclin D1, TNF-a, interleukins and MMP-9). Among the new potential delivery systems are the inorganic layered nanomaterials, specifically zirconium phosphate nanoparticles (?-ZrP). The acidic ion exchange capacity of ?-ZrP allows the incorporation of bioactive species. We propose the intercalation of curcumin into zirconium phosphate layers as a drug delivery system for chemotherapy treatment. This intercalation can be selective to cancer cells mainly by the enhanced permeability and retention effect of ?-ZrP nanoparticles. In addition, ZrP nanoparticles are thermally and chemically stable. The intercalation procedure of curcumin (Cur) into ?-ZrP was performed at a 1:1 Cur:ZrP molar ratio in 100 and 50% ethanolic solution. Results from characterization techniques such as X-ray Powder Diffraction (XRPD), Infrared Spectroscopy (IR), and Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM-EDS) will be presented.

Chemistry Presenter: Arango Lozano, Juan C.

Mentor: Marquez, Francisco

Title: Photocatalytic Hydrogen Production Via Water Splitting Using Different Gold-Based Catalysts

Authors: Juan Camilo Arango Lozano (University of Turabo), Abniel Machín De Jesus (University of Turabo), Francisco Márquez Linares (University of Turabo)

Abstract

In order to avoid serious environmental and economic damages from energy use, humans must stop using fossil fuels altogether, as soon as possible. One possible strategy to cut the dependence of fossil fuels and, at the same time create a new economic force, is to develop a hydrogen based energy economy. A potentially viable way forward is to produce H2 from water by combining solar energy and heterogeneous photocatalysts. For these reasons the objectives of this investigation were: 1) synthesize high surface area TiO2 nanowires (TiO2 NWs) catalysts in rutile phase, 2) incorporate different amount of gold nanoparticles on the surface of the as-synthesized and commercial catalysts, using a chemical reduction method, and 3) produce hydrogen via water splitting using UV-vis light. The hypotheses of the study were: a) The catalyst with higher surface area, will produce the higher amount of hydrogen, and b) The gold nanoparticles will enhance the hydrogen production and will allow the use of visible light. Interestingly, the incorporation of gold nanoparticles on the titania surface enhanced the surface area in both P25 and TiO2 NWs catalysts. The hydrogen production obtained by using Au/P25 catalysts was measured to be 800 ?molg-1h-1 under irradiation at 400 nm and 1,436 ?molg-1h-1 using Au/TiO2 NWs at the same wavelength. The characterization of the synthetized compounds was performed by using: I) X-ray diffraction (XRD) to confirm the crystalline form of the TiO2 NWs. II) Field emission scanning electron microscopy (FESEM), to confirm the morphology of the synthetized compounds. III) Surface area (BET), to measure the surface area of the gold based catalysts. IV) Gas Chromatographer with a Thermal Conductive detector (GC-TCD), to measure hydrogen production. And V) UV-vis spectroscopy (UV-VIS), to characterize the absorption thresholds of the catalysts before and after gold deposition.

Chemistry Presenter: Aviles Martin, Cristian Jose

Mentor: Alamo Nole, Luis

Title: Synthesis of CdSTe Quantum Dots Using a Microwave Assisted Method

Authors: Cristian J. Aviles Martin (PCUPR), Luis Alamo Nole (PCUPR)

Abstract

Quantum dots (QDs) are semi-conductive nanocrystals with tunable optical and physical properties. These nanoparticles have been used in applications such as solar cells, medical imaging, LED's, and photo or thermodynamic therapy. The size, band gap, and fluorescent emission can be controlled by changing synthesis parameters such as temperature. In this project, the synthesis of CdSTe QDs was achieved using a microwave assisted method. Thioglycolic acid, cadmium nitrate, and reduced tellurium (by NaBH4 reducing agent) were used as precursors. The solution was placed in a reaction vessel and irradiated in a microwave system during two steps: a pre-heating step and a reaction step. The temperature during the reaction step was changed to obtain crystals of different sizes. The optical properties of the crystals were evaluated by UV-Vis spectrometry and fluorescence analysis. UV-Vis analysis showed absorption wavelengths around 385nm. Fluorescence analysis demonstrated that the emission wavelengths are between 490 nm and 650 nm. The results suggest that an increase in synthesis temperature causes a red shift. In contrast, low synthesis temperatures produce blue shift on the emission wavelength. In future projects, these particles will be used as photo-catalysts in the photodegradation of organic dyes and pharmaceuticals.

Chemistry Presenter: Caballero León, Paola

Mentor: Medina Torres, Zuleika

Title: Building Connections across the Three Levels of Representation to Enhance Students' Conceptual Understanding about Bonding

Authors: Paola G. Caballero León (UPR-Cayey), Edgardo Ortiz (UPR-Cayey), Zuleika Medina (UPR- Humacao)

Abstract

Chemical bonding is one of the most important topics in chemistry, upon which more complex topics are based. Research studies have reported alternative conceptions related to this concept impeding 35

learning. One common alternative conception with the topic is the idea that ionic compounds exist as molecules. Previous studies have focused mainly on symbolic and macroscopic representations to develop activities in which students can explore the concept of chemical bonding. According to Johnstone, a conceptual understanding of a chemical concept requires the connection between the three representations: macroscopic, submicroscopic, and symbolic. In this project, we developed a hands-on activity to help students explore and understand the nature of chemical bonding, by incorporating the three levels of representation. Students' alternative conceptions with this topic were identified in the literature and used to develop the learning objectives that guided the development of the hands-on activity. It is expected that this new approach will enable students to acquire meaningful conceptual understanding about chemical bonding.

Chemistry Presenter: Caban-Bravo, Fabiola M.

Mentor: Kumar, Ajay

Title: Green Synthesis of Novel Aza-podophyllotoxin under Microwave Irradiation

Authors: Fabiola M. Cabán-Bravo (UMET), Ajay Kumar (UMET)

Abstract

Keywords: Pharmacology, Organic Chemistry and Toxicology

Podophyllotoxin is a natural precursor in the semi-synthesis of anticancer drugs that works as an antitumor and antibacterial ligand. The medicinal use of this ligand may include cancer, antirheumatic, cholagogue, cytostatic and purgative purposes. Podophyllotoxin is a derivative from Podophyllum peltatum and Podophyllum emodi (Berberidaceae), cultivated on high altitudes. The core structure has a dual mode action that inhibit DNA topoisomerase II and microtubule assembly through binding tubulin protein. Aza-podophyllotoxin derivatives developed by our research group, showed long-range antitumor activity at National Cancer Institute (NCI) against 60 types of human cell lines.

This project presents green synthesis of novel aza-podophyllotoxin derivatives (AP-211 and AP-211NH), using microwave irradiation in ethylene glycol and water. This method follows the American Chemical Society 12 principles of green chemistry. It has the advantage of short time reaction, high yield and minimal environmental impact of the hazardous chemicals used in traditional reactions. The current synthesis was conducted in microwave irradiation at a temperature of 110º C (Celsius), power of 300 W (watts) and a pressure of 250 psi with nontoxic solvents such as water, glycerol, glycol etc.

This Project was supported by INBRE-UPR NCCR-NIGMS Grant # 8 P20 GM 103475.

Chemistry Presenter: Caldero Rodriguez, Naishka Enid

Mentor: Montes, Ingrid

Title: Synthesis and characterization of 1,1'-symmetric ferrocenyl chalcones from 1,1'- diacetylferrocene

Authors: Naishka Enid Caldero Rodríguez (UPR-RIO PIEDRAS), Ingrid Lehman Andino (UPR-RIO PIEDRAS), Ingrid Montes González (UPR-RIO PIEDRAS)

Abstract

Since their discovery, ferrocenyl derivatives have great importance for the scientific community. Their numerous potential uses are based on their behavior as reducing agents and as excellent organic carriers of iron in high concentration. These derivatives exhibit remarkable stability in their structure and magnificent properties. Also, the framework of ferrocenyl chalcones can be considered a potent inhibitory agent, which promises treatments to outrageous diseases, including cancer and as synthetic precursors for other biological active compounds. Additionally, it has been reported that incorporating ferrocene, presented improvements in scaffolds and specific properties of previously proven compounds. Our rationale is based on the wide range of synthetic chalcones tested, and the pharmacological properties of these compounds on the literature. Our aim is to develop an efficient and selective methodology to synthesize and characterize 1,1'-symmetric ferrocenyl chalcones as the principal product from 1,1'-diacetylferrocene. So far we have synthesized these products in moderate yields by a Claisen-Schmidt condensation at high temperatures. Some of them have been obtained in short reaction times by applying a solvent-free approach. However, a mixture of cyclic product and the desired symmetric chalcone product have been obtained. We have found a relationship between the principal product obtained and the substituents and its position on the benzene ring. The synthetic methodology and characterization of these compounds will be presented.

Chemistry Presenter: Camacho Velazquez, Lizmarie

Mentor: Rodriguez Lopez, Margarita

Title: Electrochemical characterization of custom made gold electrodes in acid media by cyclic voltammetry

Authors: Lizmarie Camacho Velazquez (Pontifical Catholic University of Puerto Rico), Joelyann Valles Rivera (Pontifical Catholic University of Puerto Rico), Margarita Rodriguez Lopez 37

(Pontifical Catholic University of Puerto Rico), Jose Mercado Adrover (Pontifical Catholic University of Puerto Rico)

Abstract

Knowledge of the structure and composition of the electrochemical interface is an important question in electrochemistry. The aim of this study is to control the surface structure of custom made thin layer gold electrodes as the initial point to control one of the variables of the electrochemical interface: the electrode surface. This work is aligned with the necessity to be effective in the proper use of waste materials, for that reason we recycled fragments of salvaged thin-layer gold supported on glass from various sources and from previous projects. In this presentation it is shown the preparation and electrochemical characterization of thin layer gold electrodes that will be used as supporting phase in sensor design. Cyclic voltammetry is an electroanalytical technique useful to study electroactive species. Potential is applied to the working electrode and the signal is recorded as current vs voltage, called cyclic voltammogram (CV). CV is used as fingerprint of the electrode surface composition and structure. To obtain well characterized gold electrode surfaces, is necessary the optimization of the electrode pretreatment. Several thin layer gold electrodes were prepare. Annealing procedures were performed to alter the microstructure of the electrode in order to achieve a well characterized surface. The surface pre-treatment produces reproducible blank signals of gold electrodes in 0.1 M sulfuric acid solution in contrast with chemical pretreatment typical used in this type of electrodes.

Chemistry Presenter: Cardona Valle, Carla M.

Mentor: Pares-Matos, Elsie I.

Title: Determination of Target of Rapamycin (TOR) expression levels in Saccharomyces cerevisiae, cultivated in nutrient-limited media, via Western Blot

Authors: Carla M. Cardona Valle (University of Puerto Rico - Mayagüez), Dr. Elsie Parés-matos (University of Puerto Rico - Mayagüez)

Abstract

Many diseases are associated with disruption of the cell cycle and uncontrolled cell growth and thus, identifying molecular regulators can be useful for the development of innovative and improved medicine and treatment. Target of Rapamycin has been identified as a highly-conserved eukaryote cell growth regulator, forming a complex that is in charge of mediating metabolic processes in response to nutrient availability and other stressful environmental stimuli. This function is inactivated in presence of the drug Rapamycin, which, associated to FKBP 12 forms an immunosuppressive complex that binds to TORC 1. The objective of this study was to determine the expression levels of TOR proteins in S. cerevisiae, CFY-7 strain, incubated in galactose and glucose-limited media for 3, 6 and 12 hours. Protein 38

was quantified via BCA technique and TOR presence was identified via SDS-PAGE. Decrease in protein concentration was observed in relation to decreased carbon availability and increased time of incubation, indicating activation of TOR function. Western Blot analysis was delayed until arrival of antibodies.

Chemistry Presenter: CARRASQUILLO QUINTANA, ODEMARIS

Mentor: Perales-Perez, Oscar

Title: Synthesis and Characterization of Cd(Se,S) & Zn(Se,S) Quantum Dots for Potential Biological Applications

Authors: Odemaris Carrasquillo Quintana (University of Puerto Rico - Mayaguez), Eric Calderón Ortíz (University of Puerto Rico - Medical Sciences Campus), Oscar Juan Perales Pérez (University of Puerto Rico - Mayaguez), Sonia Bailón Ruiz (University of Puerto Rico - Ponce)

Abstract

Photo-dynamic therapy (PDT) is a treatment where photo-reactive chemicals, known as Photosensitizers (PS), are injected into the patient and irradiated with light strong enough to activate the chemicals. Photo-activation of PS causes the formation of singlet oxygen, which also form reactive oxygen species that can cause cell damage, destroying the targeted abnormal cells. Nano-particles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in PDT applications. With this aim in mid, this research addresses the synthesis of water- stable Cd- & Zn- based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- or Zn- and S-precursors, respectively. For this, thioglycolic acid concentration,temperature and reaction time were the principal parameters controlled in the microwave assisted synthesis process. The effect of reaction temperature and reaction time on the photo-luminescence properties of the synthesized nano-materials was evaluated. In addition, Photo- luminescence (PL) measurements where performed in order to determine the optimum conditions for the synthesis.

Chemistry Presenter: Citron Díaz, Yarixa L.

Mentor: Pinero, Dalice

Title: Development of phthalocyanine based water resistant NO2 Sensor

Authors: Yarixa L. Cintrón Díaz (University of Puerto Rico, Rio Piedras), Soraya Y. Flores Chalco (University of Puerto Rico, Rio Piedras), Dr. Dalice M. Piñero Cruz (University of Puerto Rico, Rio Piedras), Dr. Luis F. Fonseca (University of Puerto Rico, Rio Piedras)

Abstract

Metal phthalocyanines are one of the most widely studied family of metal complexes in the industrial and chemical research areas. One of the applications in which they are employed is in the development of gas sensor devices due to their reversible binding affinities and high sensitivities, which largely depends on the metal center in the phthalocyanine and the nature of the gas. To have a low detection limit of toxic gases is extremely important, specially in confined areas like airplanes and space shuttles, or in high combustion urban areas, like highways, among others. However, the problem of sensing low concentrations of toxic gases, like NO2, is the loss of sensitivity when exposed to high humidity concentrations (relative humidity index). The objective of this project is to develop an NO2 gas sensor capable of detecting ppm and ppb levels of the gas without being disrupted with high percentages of relative humidity. For the NO2 sensing materials, we will test nanowires synthesized from metal phthalocyanines with cobalt, aluminum, nickel, copper, iron and manganese. The synthesis of the metal phthalocyanines wires through Chemical Vapor Deposition methods will be presented. Subsequently, fluorinated and perfluoromethylated metal phthalocyanines will be tested with the idea of having hydrophobic groups on the surface, as to prevent water vapor passage towards the NO2 sensing layer.

Chemistry Presenter: Collazo Acevedo, Glorimaris

Mentor: De Jesus-Echevarria, Maritza

Title: Total Suspended Particulates (TSP) measurements in Puerto Rico Stations

Authors: Collazo Acevedo, Glorimaris (UPR-Mayagüez), De Jesús Echevarría Maritza* (UPR- Mayaguez) 40

Abstract

The distribution of the total suspended particles, TSP/PM10 depends on the sources, meteorology conditions, or time of year, and samples locations. Particles are either emitted by fossil-fuel incomplete combustion, metallurgical process, natural events such as volcanoes and dust storm. The Mayagüez Station located in the Chemistry Department of the University of Puerto Rico is recording the TSP from 2004 to the present in order to generate a database to correlate any atmospheric activities. The TSP value from Mayagüez Station was compared with the data from the different stations located around the island provided by "Junta de Calidad Ambiental de Puerto Rico" (JCA) during the year of 2015. The highest average TSP value per month in Mayagüez was 73 µg/m3 in the month of May and it exceeds the Environmental Protection Agency (EPA). The arithmetic mean for the Adjuntas, Cataño and Ponce station in May also The Guaynabo station had their highest average TSP/PM10 per month value on August. These stations do not exceed the EPA monthly parameter. The highest TSP value per day reported in the Mayagüez Station was 99 µg/m3 and the others stations had highest values in the range of 65 µg/m3 to 134 µg/m3 and also they did not exceed the EPA TSP/PM10 daily parameter. The X-Ray Diffraction analysis of the filter with the TSP highest value of Mayagüez Database shows the present of several minerals, calcite, metaschoepite, yugawaralite, scorodite, hoelyte, alunogen, anorthite and quartz.

Chemistry Presenters: Colón Ríos, Daniel A. Aldarondo Torres, Álani

Mentor: Lopez Garriga, Juan

Title: Hydrogen Sulfide as a Potential Inhibitor of Insulin (IBP) Amyloid Fibrils

Authors: Daniel A. Colón Ríos (Department of Chemistry, University of Puerto Rico, Mayaguez Campus), Álani Aldarondo Torres (Department of Industrial Biotechnology, University of Puerto Rico, Mayaguez Campus), Alfredo Reyes Oliveras (Department of Chemistry, University of Puerto Rico, Mayaguez Campus)

Abstract

Amyloid fibrils are formed by soluble proteins that, through the process of protein unfolding, assemble into undegradable insoluble fibers. These amyloid fibrils are associated to many types of diseases, like Diabetes Type 2, that are characterized by the specific protein or peptide chain that aggregates extracellularly to a body tissue. The process of protein unfolding and fibrillation can be promoted by applying extreme conditions of high temperature and low pH to the desired protein. It has been proven that by adding hydrogen sulfide (H2S), hen egg white lysozyme (HEWL) amyloid fibrils can be inhibited (Rosario, 2014). Due to the fact that lysozyme possesses structural similarities with insulin, it was 41

considered a biological model to carry out the experimentation with Insulin from Bovine Pancreas (IBP). With the goal of thoroughly studying the H2S-protein interactions, 10 mg/mL IBP solutions were prepared with different ratios of H2S. The existence of amyloid fibers was determined by qualitative methods, such as the careful examination of the samples at different time intervals, and by quantitative methods, such as ThT Fluorescence. The samples without H2S and the samples with a one on one molar ratio (IBP: H2S) showed a fibril-like structure characteristic of amyloid aggregates. Contrary to the results with lysozyme, the samples with small ratios of H2S suggest the presence of amyloid fibrils. Furthermore, HEWL and IBP protein samples express the same behavior when exposed to high H2S concentrations and extreme temperature; both promote gelification. When performing ThT Fluorescence, all samples presented fibril formation, although a decrease in fluorescence was observed as the H2S concentration increased. Future analyses like Circular Dichroism, Atomic Force Microscopy (AFM), Raman Spectroscopy and Scanning Electron Microscopy (SEM) will be performed to study the structure and kinetics of these substances.

Chemistry Presenter: Cordero Landron, Mari•a Del Mar

Mentor: Diaz-Vazquez, Liz

Title: Fabrication of an Amperometric Biosensor to Detect the Neurotoxin Domoic Acid in Estuarine Environments

Authors: Maria Del Mar Cordero Landron (UPR Rio Piedras), Liz Diaz Vazquez (UPR Rio Piedras)

Abstract

Some algal species are capable of producing toxins which threaten human health. The genus Pseudo- nitzschia includes several species of diatoms that produce the neurotoxin Domoic Acid (DA). In mammals DA acts as a neurotoxin, causing short-term memory loss, brain damage and in severe cases, death. Currently, the most common method for the detection of DA uses high performance liquid chromatography with fluorimetric detection (HPLC-FLD). We need far more sensitive and fastest detection methods. This project is directed towards determining whether the fabrication of an immunosensor using gold nanoparticles (AuNPs), graphene and anti-DA antibody is capable of a sensitive, specific, and a fast detection of DA or not. If we create an immunosensor using AuNPs, graphene and an antibody, the recognition and sensing activity of the generated device will be better that the existing DA sensors. This is because AuNPs and graphene will increase the conductivity and provide more superficial area for the binding of the antibody. The antibody will be responsible for the selective detection of DA. Thus, contributing to the improvement of the detection and quantification limits of the immunosensor. The progress and quality of the fabrication process of the proposed immunosensor will be monitored performing cyclic voltammetry (CV) of each successive immobilization step into glassy carbon electrodes using ferricyanide as a standard. The efficacy of the fabricated 42

biosensor for the detection of DA will be tested by CV. The detection is based on the change in the potentiometric response before and after the antigen-antibody reaction. With this project we propose a new method for the detection of domoic acid and thus, an effort to decrease the incidence of intoxication cases by DA.

Chemistry Presenter: Cruz Echevarría, Juan C.

Mentor: Santos-Santori, Lizette

Title: Effects in the Cytochrome P450 System of Chinese Hamster Ovary Cells Treated with Low Concentrations of Formulas of Azadirachta indica

Authors: Juan Carlos Cruz-echevarría (Pontifical Catholic University of Puerto Rico), Lizette Santos-santori, Phd. (Pontifical Catholic University of Puerto Rico)

Abstract

Azadirachta indica, commonly known as Neem tree, is one of the oldest medicinal plants used in the world. The Neem tree grow mostly in India. Among its applications are properties associated with the immune system, dermatological, anti-cancer, diabetes, and possible insecticide. The objective of this research is to analyze the effects of extracts of Neem leaf in the cytochrome P450 system of Chinese Hamster Ovarian cells (CHO cells). CHO cells were cultured and sub cultured. Dried leaves and undried leaves extracts were prepared. Cells were treated with different concentrations of the extracts: 100 mg/L, 300 mg/L and 3000 mg/L. Microsomes were prepared and the following assays were performed: Bradford, Cytochrome P450 content, p-Nitrophenol Hydroxylase, Erythromycin-N-demethylase (ERND), and 7-Ethoxyresorufin deethylase (EROD). Protein content, following Bradford assay, showed a higher concentration for the cells treated with the tea of the undried leaf. ERND enzyme activity and p- Nitrophenol hydroxylase decreased for all extracts concentrations with the exception of those treated with the extracts of the dried leaf of 3000 mg/L. EROD showed a higher activity for the extracts of the dried leaf of 3000 mg/L. All cells treated showed a decrease in the activity of the cytochrome P450 with the exception of those treated with the extracts of the dried leaf of 300 and 3000 mg/L. Components of the extracts will be studied using the method of HPLC and the effects of these components will be analyzed on the activity of the isoenzymes. The results will be validated by performing statistical analysis methodology.

Chemistry Presenter: Dávila Barreiro, Arielys M.

Mentor: Oyola, Rolando

Title: The study of the oligomerization of A?1-40 in the presence of Nicotine derivatives.

Authors: Arielys M. Dávila Barreiro (UPR-Humacao), Ambar S. Delgado Carrión (UPR-Humacao), Arisdelsy Cervantes (UPR-Humacao), Margarita Ortiz (UPR-Humacao), Rolando Oyola Martínez (UPR-Humacao)

Abstract

Alzheimer disease has been related to the presence of plaques due to the Ab(1-40) peptide oligomerization. Thus, it has been proposed that a probable alternative to minimize plaque formation is using drugs that inhibit Ab(1-40) oligomerization. Nicotine inhibits Ab(1-40) oligomerization but new derivatives with higher efficiency/potency are desirable. In this work, we test two new nicotine derivatives, Drug B and C) as an alternative inhibitors. To fulfill this objective we measured the Ab(1-40) oligomerization kinetics using thioflavin as fluorescence probe. Briefly, Ab(1-40) was purified by liquid chromatography, lyophilize, and the solutions were prepared to measure the oligomerization kinetics using a microplate reader. The results shows that the emission follows a typical sigmoidal response for all samples. The lag phase relative to Ab(1-40), the control, is Drug B > Drug C ~ nicotine. The emission maximum, which is related to the number of oligomers, shows that Drug C promotes higher number of oligomers than nicotine or Drug B. C. Experiments are underway to verify this behavior as a function of drugs concentration. In addition, the diameter of the oligomers in solution will be determine using dynamic light scattering.

Chemistry Presenter: Dávila Calderón, Jesse

Mentor: Montes, Ingrid

Title: Ferrocenyl epoxide derivatives as potential bioactive anticancer compounds

Authors: Jesse Davila Calderon (University of Puerto Rico, Rio Piedras Campus), Ingrid Montes, Phd (University of Puerto Rico, Rio Piedras Campus), Juan C. Aponte (University of Puerto Rico, Rio Piedras Campus) 44

Abstract

Exploration of drugs with a specific biological target has become a challenge for research. Studies with several compounds have been started, including colchicine. This compound is known for its anti- inflammatory properties and antitumor activity. Therefore, it is believed that synthetic compounds or analogues that maintain similar structures or properties, will result in an increment in the bioactivity. Among them are the combretastatin A-4 derivatives, where an epoxy ketone analogue has been tested for cytotoxicity in melanoma (B16) and leukemia (L1210) cancer cell lines, with IC50 in a range from 25 to >100 ?M. Other analogues of interest and with prominent characteristics are the chalcones, that have also demonstrated antibacterial activity. The literature highlights that the incorporation of ferrocene in the structure of known compounds increases the ability of biological activity. Furthermore, the addition of a heterocycle, in combination with ferrocene, promises to improve the bioactivity of ferrocenyl compounds. Our research focuses on the synthesis of ferrocenyl chalcones derivatives, demanding an importance to ferrocenyl chalcones and the addition of an epoxide as a heterocycle to its structure. We are leading our specific purpose, with a study to determinate essential structural properties of compounds to predict and correlate biological properties. We are aiming to synthesize and characterize ferrocenyl chalcones epoxide derivatives via a Darzen-type reaction, from ferrocenecarboxaldehyde and ?-chloroacetophenones. Precursors for epoxide derivatives have been achieved in moderate to good yields. They have been characterized by 1H and 13C NMR spectra. Likewise, we will study the effect of different substituents in the phenyl group such as: methoxy, nitro, and fluorine, based on literature reviewed, as the most prominent for cancer treatment. Synthetic methodology and characterization of these compounds will be elaborated.

Chemistry Presenter: De Jesus, Pedro R

Mentor: Rivera-Tirado, Edgardo

Title: Análisis de compuestos volátiles presentes en aceites comerciales utilizando las técnicas de SPME y GC-MS

Authors: Pedro R. De Jesús Cruz (University of Puerto Rico at Cayey)

Abstract

El uso de aceites para la lubricación de partes de equipos mecánicos es una práctica común, tanto en la industria de la construcción como en la industria automotriz. Los aceites comerciales, entre los cuales se encuentra el Purple, poseen aditivos que hacen más eficientes el mismo. Muchos de estos compuestos son volátiles y pueden ser tóxicos a altas concentraciones, por lo que una exposición prolongada y frecuente a estos aceites puede provocar problemas de salud. El propósito de esta investigación es desarrollar un método eficiente y de bajo costo para analizar compuestos volátiles presentes en los aceites, tales como los alcoholes, tioles, fosfatos, etc. utilizando la técnica de Micro-Extracción en Fase 45

Sólida (SPME) junto con un equipo acoplado de cromatografía de gas-espectrometría de masas (GC-MS). El análisis se realizó a muestras pequeñas, y las ventajas principales de este método son que no requiere el uso excesivo de solvente, es de bajo costo, detecta concentraciones pequeñas (partes por millón; ppm) y el tiempo que se invierte para el análisis de las muestras es corto. Tras llevar a cabo la parte experimental de este proyecto, se obtuvo como resultado que los compuestos analizados, sobrepasaban los límites de detección que las agencias reguladoras establecen, por lo que una exposición continua a este aceite puede ser perjudicial para la salud del ser humano.

Chemistry Presenter: De Jesús Morales, Gilberto L.

Mentor: Lopez-Mejias, Vilmali

Title: Design of Biotemplated High Porosity Metal Oxide Electrodes for Dye-Sensitized Solar Cells

Authors: Vilmalí López Mejías (University of Puerto Rico, Río Piedras Campus), Gilberto De Jesús Morales (University of Puerto Rico, Río Piedras Campus), Andrew Kirtek (University of Puerto Rico, Río Piedras Campus)

Abstract

Dye-sensitized solar cells (DSSCs) are a flexible, low cost and easily manufactured alternative to harvest energy from sunlight. Despite these advantages, DSSCs have not presented a significant increase in their efficiency over the past decade. The crystallization of highly porous metal oxide morphologies with well- defined and narrow pore size distribution is a key factor for the successful device operation in DSSCs. The proposed research aims to synthesize highly porous anatase TiO2 with narrow pore distribution using several cellulose-based polymers as soft templates to control the crystallization of the metal oxide, heterogeneously. The effect of the structural diversity of single and multi-component bio-polymer mixtures, as well as different deposition and processing methods will be tested systemically to reveal the most efficient bio-template for the DSSC. Four different cellulose-based polymers (CBPs), methyl 2-hydroxyethyl cellulose (M2HE), hydroxyethyl cellulose (HEC), ethyl cellulose (EC) and hydroxypropyl cellulose (HPC), were employed as bio-templates in the synthesis of TiO2 through a sol- gel method. The effects of polymer percent composition, titanium precursor, water, acetic and nitric acid concentration in the sol-gel synthesis were tested systematically to achieve an understanding of the effects of each one of these components on the average TiO2 particle size. Experimentally, the TiO2 morphologies and particle size have been characterized utilizing powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Preliminary PXRD results have shown a significant decrease in the particle size of the produced TiO2 from 13 ±1 nm in samples synthesized without the use of a bio- template to 7.7 ± 0.4 nm for the samples in which HEC was employed as the bio-template. These results suggests that bio-templation can be used to create unique mesoporous TiO2 morphologies with control 46

over particle size, porosity, and surface area. Future work includes the study of multi-component biopolymer mixtures and the exploration of different CBPs during the sol-gel synthesis of TiO2.

Chemistry Presenter: De Jesús Santa, Evony C.

Mentor: Rivera Claudio, Mirna

Title: Synthesis and Characterization of Chalcones

Authors: Evony C. De Jesús Santa (University of Puerto Rico at Humacao), Mirna Rivera Claudio (University of Puerto Rico at Humacao)

Abstract

Synthesis and Characterization of Chalcones

Chalcones are aromatic ketones that form a central core for a variety of biological activity. They can conceive as open-chain flavonoids, where the two aromatic rings are linked by a conjugated three- carbon system, with a carbonyl and an alkene group. In nature, chalcones have the characteristic of producing compounds such as flavonoids, which have been proven to work as antibacterial, antifungal and anticancer agents, depending on their aromatic substitution. It has been found that chalcones have shown a wide variety of antibacterial, anticancer and anti-inflammatory activities. It has been proven that the inhibitory action of chalcones on the pathogens in humans correlates directly with the substitution in the aromatic ring. This means that chalcones are excellent antibacterial agents. In recent years, cancer has become one of the leading causes of death in the United States and Puerto Rico. That is why scientists are trying to find new molecules with the capacity to inhibit tumor initiation and progression. According to the literature, halogenated chalcones are the best compounds that show high anticancer activity.

According to the literature, the main way of obtaining chalcones is the synthesis of these compounds through the condensation of an aldehyde with a ketone. Following a modified literature procedure, a ketone (1) in basic pH was reacted with the selected aldehyde (2) in order to obtain our desired chalcone (3).4 The compounds were placed in a three-necked round bottom flask and stirred about 24 hours. After synthesizing, the product was extracted with an organic solvent and dried with sodium sulfate. The solvent was removed and the crude was analyzed by FT- Infrared Spectroscopy. In order to find the optimum separation conditions, thin layer chromatography (TLC) was used. After finding the ideal separation conditions, column chromatography was used to purify the compounds. This research is currently in the stage of full characterization of the product, which consist in the used of FT - infrared Spectroscopy, Gas Chromatography-Mass Spectroscopy (GC-MS) and Nuclear Magnetic Resonance (NMR). It is our goal to optimize the conditions to improve the yield of the reaction. In the next stage of 47

the research one specific aim is to evaluate the anti cancer or anti inflammatory properties of the new compounds.

References:

1) Ramírez, M., Barajas, L., Pérez,C., Sáenz, A., Silva,S.; Synthesis and Biological Activity of Chalcones; (September 10,2012); Retrieved October 28,2015, from http://www.redalyc.org/articulo.oa?id=57928311002

2) Pereira,H., Albino, E., Deller, F., Smania, A. (2008). Structure–activity relationship of antibacterial chalcones. Bioorganic & Medicinal Chemistry, 9790-9794. Retrieved December 28, 2015, from www.elsevier.com.

3) Dias, T., Duarte, C., Lima, C., Proenca, F., Pereira, C. (2013). Superior anticancer activity of halogenated chalcones and flavonols over the natural flavonol quercetin. European Journal of Medicinal Chemistry. Retrieved November 13, 2015, from www.elsevier.com.

4) Robinson, M. W., Overmeyer, J. H., Young, A. M., Erhardt, P. W., & Maltese, W. A. (n.d.). Synthesis and evaluation of indole-based chalcones as inducers of methuosis, a novel type of nonapoptotic cell death. [Scholarly project]. Retrieved September 14, 2015, from http://www.ncbi.nlm.nih.gov/pubmed/22335538

Chemistry Presenter: Delgado Carrión, Ambar S.

Mentor: Oyola, Rolando

Title: The study of the oligomerization process of IAPP in presence of Au-Nanoparticles.

Authors: Ambar Delgado Carrión (UPR- Humacao), Arielys Davila (UPR- Humacao), Rolando Oyola Martínez (UPR- Humacao), Carlos Andino Ramos (UPR- Humacao)

Abstract

Islet amyloid polypeptide or IAPP is a peptide that is co-secreted together with insulin by the beta cells of the pancreas. It is believed that when this protein suffers from miss folding or wrong post- transduction processing, the cell does not accomplish its degradation properly and the peptide exits the cell and starts to form what is known as oligomers. This process causes permanent damage to the beta cells affecting the production of insulin. The study of the effect of gold nanoparticles (Au-Nanoparticles) 48

in the formation of IAPP oligomers will be performed using the analysis of fluorescence emission with thioflavine (as a probe), tris buffer solution (pH 7.5) and different concentrations of 13 nm gold nanoparticles. The main objective of this study is to observe if the nanoparticles makes any type of interaction or if the polypeptide feels affinity with the nanoparticles' surface, and how this interaction may cause any change in the kinetics, quantity of oligomers and size of the oligomers formed in this process. In the results we can observe that with 180 uL of gold nanoparticles solution caused a decrease in the quantity of oligomers formed in contrast with the control group and the other experimental groups which had different volumes of nanoparticles solution. Finally with the purpose of analyzing the variability in diameter of the oligomers, the Dynamic Light Scattering (DLS) technique will be performed to the solutions previously used in the fluorescence analysis as soon as possible after the fluorescence analysis ends.

Chemistry Presenters: Diaz Reyes, Zaibeth Flores Rivera, Mariola M.

Mentor: Melendez, Enrique

Title: Estrogen's Functionalized With Ferrocene As Pendant Group: A Potential Therapeutic Drug For Estrogen Receptor Positive (ER+) Breast Cancer

Authors: Zaibeth Diaz Reyes (Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus), Mariola Flores (Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus), Enrique Melendez (Department of Chemistry, University of Puerto Rico, Mayagüez Campus), Jose Carmona (Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus)

Abstract

Breast cancer represents about 50% of the cancer incidence rate in women's population, being the Estrogen Receptor Positive (ER+) the most common in this group. In fact, the over-expression of the alpha estrogen receptor (ER?) in hormone dependent cancer is responsible for the abnormally increase of cell proliferation rate. Conventional metal-based therapeutics drugs, such as cisplatin and derivatives, are still used in order to inhibit this abnormal cellular proliferation rate. However, cisplatin-based drugs are highly cytotoxic, triggering a series of side effects that become detrimental to the body, due to their lack of selectivity between healthy and cancerous tissue. In order to develop a novel metal-based therapeutic drug with a high selective index over the cancer tissue, estrogen hormones have been functionalized with ferrocene as pendant group on estrogen's D ring. Previously, 16-ferrocenylidene-3- hydroxyestra-1, 3 , 5 (10)-trien-17-one (16-Fc-E1) was synthetized with ferrocene as pendant group using estrone and ferrocene carboxaldehyde as starting material in 86% yield, showing cytotoxic activities on MCF-7 hormone dependent breast cancer cell line. This ferrocene complex has been used 49

as a template molecule to synthetize a series of estrogen derivatives with ferrocene as pendant group. Subsequently, reduction of the carbonyl group and hydrogenation of the doble bond were realized as modifications to observe its anti-cancer properties. In this work, we present these series of synthesized ferrocene complexes with its characterization by X-ray crystallography, in vitro cytotoxic studies on hormone-dependent MCF-7 breast cancer cell line, and docking studies on the ER?.

Chemistry Presenter: Dieppa, Diomedes

Mentor: Rivera, Jose

Title: Redox-responsive Supramolecular Hacky Sacks

Authors: Diómedes Dieppa Matos (University of Puerto Rico, Río Piedras), Luis M. Negrón (University of Puerto Rico, Río Piedras), Maxier Acosta Santiago (University of Puerto Rico, Río Piedras), José M. Rivera (University of Puerto Rico, Río Piedras)

Abstract

The cytoplasm of a cell has a reductive environment resulting from biothiols such as glutathione (GSH). GSH is becoming an important stimulus for therapeutic delivery agents. 8-aryl-2'-deoxyguanosine (8ArG) derivatives can self-assemble in the presence of potassium cations to form higher ordered structures known as supramolecular G-quadruplexes (SGQs). These SGQs respond to external stimuli (change in temperature and/or pH) to form colloidal particles we term supramolecular hacky sacks (SHS). We have shown that such SHS are suitable carriers for therapeutic agents like anticancer drugs and genes. The goal of this project is to develop redox-responsive SHS, specifically, responsive to the reductive environment of a cell, which could serve as the basis for the controlled release of therapeutic agents. This redox-responsiveness arises from the Michael-type addition of thiols to the -carbon of an ,- unsaturated ketone. We also want to study the absorption and emission properties of the 8ArG derivatives and their Michael adducts in order to develop a tracking method of the redox behavior of these particles inside cells. We hypothesize that thiols (e.g., mercaptoethanol, cysteine, GSH) will react in a Michael-type addition with the 8ArG constituents of the SHS and that the resulting modifications will result in physical and chemical properties (e.g., hydrophilicity, size) that will promote the release of any encapsulated therapeutic agent. We will present characterization of the the monomer, self- assembly studies, and thermo-responsive studies by techniques such as nuclear magnetic resonance, UV-Vis spectroscopy, and turbidity studies. The impact of these modifications on the biological properties of these SHS particles will be discussed, with the aim of expanding the toolbox for the delivery and controlled release of biomedically relevant molecules.

Chemistry Presenter: Echevarria Maldonado, Carlos

Mentor: Batista, Adalgisa

Title: Synthesis of Cathecol Analogs

Authors: Carlos L. Echevarria Maldonado (PCUPR), Adalgisa Batista (PCUPR)

Abstract

Catechols are very important molecules that are being studied in the fields of chemistry and biology. These molecules are used in the industry for the synthesis of pharmaceuticals, agrochemicals and antioxidants. Antifungal activity has also been studied in catechols. It is well known that catechols have a major role in biological systems. Catechols are active participants in the transport of electrons. Because of this characteristic the quinone/hydroquinone capabilities of the catechol is being studied. Also it has been found that catechols have the ability to interfere with the proliferation of human lymphocyte, production of nitric acid and growth of human cancer lines. It has been found by recent studies that catechols are able to form complexes that can create organometallic bonds. There are many pathways to synthetize catechol. Industrially catechol is synthetized primarily by the oxidation of phenol. It can also be obtained by transforming D-glucose with E. coli. The goal of this research is to prepare catechols with different structures. The method to synthesize each catechol analog will vary. We are currently performing the synthesis of six catechol analogs. Five of the analogs will have the same base catechol, 1,4-dimethoxybenzene, the difference will be the carbon chain attached to the catechol. Recently we were able to synthesize Bis (3,4 dimethoxyphenyl) methanone using as starting materials 3,4 dimethoxybenzoic acid and 1,2 dimethoxybenzene. The compound will be reduced to create another catechol analog called 4,4 methanediylbenzene 1,2 diol. After being synthetized the electrochemical behavior of each analog will be studied.

Chemistry Presenter: Figueroa Cosme, Darinelys

Mentor: Torres, Wildeliz

Title: Studies toward an In(III)-catalyzed one-pot methodology for the synthesis of substituted indoles and benzofurans

Authors: Darinelys Figueroa Cosme (University of Puerto Rico at Mayaguez) 51

Abstract

Indoles and benzofurans are widespread in synthetic drugs and bioactive natural products. Not surprisingly, their synthesis and reactivity has been extensively studied. Domino or one-pot processes are very efficient ways to access organic molecules since time and resource consuming isolation and purification steps are avoided. Thus, we are interested in developing a one-pot methodology that lead to multi-functionalized indoles and benzofurans from 2-iodoanilines and 2-iodophenols, respectively. We chose In(III) catalysis based on its affordable price, low toxicity, recyclability and compatibility with functional groups. The basis of this methodology and our developments will be presented.

Chemistry Presenter: Figueroa Gordián, Katherine J.

Mentor: Alamo Nole, Luis

Title: Toxicity of CdSSe and CdSTe nanoparticles on Artemia Salina

Authors: Katherine J. Figueroa Gordián (PUCPR), Luis Alamo Nole (PUCPR)

Abstract

Artemia salina is a brine shrimp considered as aquatic crustaceans. There is data that shows it has been present for millions of years on our planet. They have been used to perform many experiments because of they survived a lot of drastic changes over the years. Brine shrimp is widely used for toxicity bioassays of different chemicals. The purpose of this research is to determine the toxicity of the CdSSe and CdSTe quantum dots (QDs) with and without light irradiation. The QDs were synthesized using a microwave system at 180 ° C of reaction temperature. CdSTe nanoparticles were synthesized in an oxygen free environment. Both nanoparticles were characterized by UV-VIS and photoluminescence analysis. The excitation and emission wavelengths were 380 nm and 654 nm, respectively. LD50 test measures the dose that kill fifty percent of the group of animal due to any kind of alteration. It is expected that the LD50 test provides the CdSSe and CdSTe concentrations which may have undesirable effects on living organisms.

Chemistry Presenter: Flores, Andrea Del Mar

Mentor: Primera-Pedrozo, Oliva M.

Title: Encapsulation of CdSe Quantum dots with Silica to increase biocompatibility

Authors: Andrea Del Mar Flores Hernández (Universidad Metropolitana (UMET)), Jonathan Alfredo López (Universidad Metropolitana (UMET)), Joshua Medina (Universidad Metropolitana (UMET))

Abstract

Quantum dots (QDs) have a key role in bioimaging as fluorescent probes for biological sensing. Cadmium selenide (CdSe) QDs are considered toxic due to the release of Cd2+. QDs can be coated polymers or silica to prevent degradation. The challenge was to prepare highly luminescent semiconductors, biocompatible and water soluble QDs. Direct water synthesis of CdSe/QDs was performed using thioglycolic acid (TGA), mercaptopropionic acid (MPA), L-Cysteine (L-Cys) and Glutathione (GHS) as capping agents. Experiments with E.coli, B.subtillus, S.aureus, P.aeruginosa, M. smegmatis showed that the QDs could cause harm depending on their ligament. Using the Kirby–Bauer antibiotic testing technique, several culture plates were prepared for each of the bacteria, with different concentration of the nanoparticles. Using the antibiotic penicillin as a positive control and water as a negative control, in addition, a concentration of 0.01mM of cadmium was also present as a control. This was performed with MPA, TGA and L-Cys QDs using concentration of 0.1mM and 0.01mM, with three replicas each. Preliminary results proved that cadmium on their own was toxic to gram positive and acid resistant bacteria while the gram-negative were not affected. In the other hand, the MPA QDs at 0.1 mM presented harm to the bacteria while the other concentration and ligands did not present any effect. Future experiments will be looking at the growing curve of the bacteria while the QDs are present and put to test the stability of the QDs in the bacteria media.

Chemistry Presenter: Frias, Cecilia

Mentor: Diaz-Vazquez, Liz

Title: Coupling of Seawater Anaerobic Digestion and Hydrothermal Liquefaction of the Macroalgae Sargassum spp. to Enhance Energy and Nutrients Recovery

Authors: Cecilia B. Frias-flores (Environmental Sciences Department, University of Puerto Rico-Rio Piedras), Arnulfo Rojas-perez (Chemistry Department, University of Puerto Rico-Rio 53

Piedras), Jodany Fortuné (Environmental Sciences Department, University of Puerto Rico-Rio Piedras), Antonin Forestil (Environmental Sciences Department, University of Puerto Rico-Rio Piedras), Gary W. Gervais (Environmental Sciences Department, University of Puerto Rico-Rio Piedras), Liz M. Díaz-Vázquez1 (Chemistry Department, University of Puerto Rico-Rio Piedras)

Abstract

The use of macro-algae has become popular for as a feedstock for the production of energy using different conversion processes. A blend of Sargassum spp. from the northern coast of Puerto Rico was fed to two bioreactors at different salinities (1.0% & 3.5% w/w) for biogas production. Afterwards, the reactor effluents were collected and characterized to determine their composition and subsequently submitted to HTL. The HTL process took place at 340 ºC with a minimum of 100 psi and 300 rpm. The products of the reaction were separated and each phase was analyzed using Fourier Transform Spectroscopy (FTIR-ATR), Gas Chromatography-Mass Spectrometry (GC-MS), elemental analyses for Carbon, Hydrogen, Nitrogen, Sulfur and Oxygen content (CHNS/O) and Energy-dispersive X-Ray Spectroscopy (EDS). The bio-oil yield obtained was 13.50% for the 1.0% w/w salinity effluent and 6.03% from the 3.5% w/w bioreactor.

Chemistry Presenter: Fuentes Rivera, Jose J.

Mentor: Cabrera, Carlos

Title: Detection of cervical cancer cells by electrochemical impedance spectroscopy

Authors: Carlos Cabrera, Ph.d., Griselle Hernández, Ph.d, Etienne Colón, José Fuentes

Abstract

Biosensors are a promising technology for cancer detection due to their high sensitivity and fast response. Although biosensors utilizing biomolecules (e.g., DNA, RNA, proteins) are effective, they tend to suffer from the same disadvantage; they are sensitive to environmental conditions. Thus, reducing considerably their shelf life thereby diminishing their utility and reliability. In this work, a robust, inexpensive, flexible, and effective sensor was constructed and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The sensor was constructed using polyimide film with gold deposited on its surface. The first step of the sensor construction was the formation of a cysteamine self-assembled monolayer (SAM) used to immobilize covalently folic acid (FA). AFM and XPS experiments confirmed the SAM formation and the FA immobilization. EIS technique was used to track the binding between the folic acid molecule and the overexpressed folate receptor on the HeLa cell surface. A gradual increase of resistance on the electrode's surface was observed through 54

time while exposed to the HeLa cells in solution. The change in charge resistance of the sensor was linear from 100 cells mL-1 to 5000 cells mL-1. Eventually, this sensor can be used as a screening tool in potentially vulnerable patients for the early detection of multiple types of cancers that overexpress folate receptors as well.

Chemistry Presenter: García Almedina, Derek

Mentor: Diaz-Vazquez, Liz

Title: Synthesis of a Whole-Cell Imprinted Polysaccharide-Silica Matrix for the Immobilization of V. fischeri, as a Biosensor of Emerging Contaminants

Authors: Derek M. García Almedina (Department of Chemistry, University of Puerto Rico Río Piedras Campus), Zomary Flores-cruz (Department of Biology, University of Puerto Rico Río Piedras Campus), Liz M. Díaz Vázquez (Department of Chemistry, University of Puerto Rico Río Piedras Campus)

Abstract

Throughout history, humankind has created countless substances for the improvement of their quality of life, such as personal care products and pharmaceuticals. However, only a fraction of these man- made substances are regulated, and most of them end up in bodies of water and affect aquatic as well as terrestrial organisms. It is very difficult for relevant agencies to keep up with the millions of compounds that have been found or created, and thus the development of methods for their detection and remediation is very important. This project aims to construct a biosensor for the detection of environmental pollution, through the synthesis of a whole cell imprinted polysaccharide-silica matrix. For this purpose, Ulvan (a polyanionic algal polysaccharide) was extracted from Ulva lactuca and purified. BCA protein assay showed that the protein content of the extract was approximately 3%. IR Spectrum of the polysaccharide showed the characteristic ulvan peaks. After the extraction, Ulvan - along with THEOS as the silica precursor- was used in the synthesis of a nanostructured material through the sol-gel method. Using the whole cell imprinting technique, the material was imprinted with V. fischeri cells, for their eventual immobilization and use as the biological component of the biosensor. Thermogravimetric Analysis (TGA) of the whole cell imprinted gels showed that the material was thermally stable up to 700C, losing only 14% of its initial weight with 10% being solvent loss. SEM micrographs revealed that the first attempt at immobilizing the bacteria was only partly successful, as they underwent cell lysis. For the next attempts, reaction conditions must be modified to avoid this. V. fischeri was chosen as the biological component because of its ability to grow and emit bioluminescence. The bacteria were grown in the presence of various emerging contaminants, which had no effect on its growth, except when the bacteria were exposed to known antibiotics. Conversely, bioluminescence did change significantly in presence of caffeine and amlodipine besylate, which would 55

allow V. fischeri to be used for the detection of these contaminants in water. Future work includes the supercritical drying of the gel, metabolomics of the bacteria, and testing the bacteria against other contaminants for the eventual construction of the biosensor.

Chemistry Presenter: Garcia Betancourt, Adlin V.

Mentor: Rivera, Jose

Title: Design, synthesis and fluorescence studies of a hydrogen peroxide-responsive chalconyl derivative

Authors: Adlin V. Garcia Betancourt (UPR RIO PIEDRAS), Luis A. Prieto Costas (UPR RIO PIEDRAS), Yanira Rodriguez (UPR RIO PIEDRAS), Jose M. Rivera (UPR RIO PIEDRAS)

Abstract

Reactive oxygen species (ROS) are reactive molecules that are a byproduct of the metabolism of oxygen. Hydrogen peroxide (H2O2), an example of ROS necessary to maintain cell fitness, is linked to aging and diseases such as neurodegeneration, diabetes and cancer. Boronic esters are used as ROS probes because they are chemoselective towards H2O2 generating phenols as oxidation products. As a long- term goal, we will take advantage of this and make a drug delivery system based on H2O2-responsive supramolecules made from guanosine derivatives containing boronic ester groups. In the short-term, we need to study the physicochemical properties of boronic ester based model compounds. Herein, we will present the synthesis and fluorescent properties of a model compound (an heteroaryl-boronic ester) at various concentrations of hydrogen peroxide. Specifically, we will present the synthesis of a model compound using a DIMCARB-promoted Claisen-Schmidt condensation between acetophenone and a boronic ester aldehyde. We will also show the characterization studies of such compound using various 1D/2D NMR experiments. The synthesis and fluorescence studies of model compounds will enable the development of a peroxide-responsive supramolecules for applications in biomedicine.

Chemistry Presenter: Garcia Rodriguez, Jennifer M.

Mentor: Ortiz-Marciales, Margarita

Title: Synthesis of Chiral Oxetanes via the Enantioselective Reduction of Prochiral 2- Halogenated Ketones

Authors: Jennifer M. Garcia Rodriguez (UPR-H), Javier E. Lopez Hernandez (UPR-H), Blanca Quinones Diaz (UPR-H), Sandraliz Espinosa Diaz (UPR-H), Margarita Ortiz Marciales (UPR-H)

Abstract

The enantioselective reduction of prochiral 2-halogenated ketones is a practical and effective way to synthesize nonracemic g-halogenated alcohols, which can be transformed into enantiopure oxetanes. The ring opening of oxetanes with amino compounds can produce a variety of optically active amino alcohols, which are key precursors in the synthesis of biological active compounds, particularly, for the treatment of neurological diseases, such as depression and anxiety. Our work is based on the asymmetric borane–mediated reduction of prochiral ?-halogenated aryl ketones to their corresponding optically active alcohols using as catalyst the spiroaminoborate ester derived from ethylene glycol, triisopropyl borate and (S)-(-)-diphenyl-2-pyrrolidinemethanol. The enantiopure alcohols were purified by column chromatography with silica gel and characterized by 1H NMR, 13C NMR, IR, GC/Chiral Column and GC/MS. The cyclization of the nonracemic alcohols to form the oxetane was successfully achieved using 3 equivalents of potassium tert-butoxide as base, obtaining the oxetane in good yield.

Chemistry Presenter: Garcia-Vazquez, Nelson

Mentor: López-Mejías, Vilmalí

Title: Development of Biocompatible Metal-Organic Frameworks for Drug Delivery Applications

Authors: Nelson García-vázquez (University of Puerto Rico - Río Piedras), Vilmalí López-mejías (University of Puerto Rico - Río Piedras)

Abstract

Metal-organic frameworks (MOFs) are materials composed of metal ions or clusters coordinated to organic linkers, forming single or multi-dimensional structures that can exhibit high porosity. These 57

materials also present interesting physical properties attributable to their high surface area, making them prospects for different applications in catalysis, gas storage, and separations. Recently, studies have focused on designing MOFs for drug delivery. In some of these studies the produced MOFs fails to be completely biocompatible, or the synthetic procedure is done in solvents that present high toxicity, thus, restricting its usage to merely academic curiosity. This work aims to develop a set of completely biocompatible MOFs, denoted as bioMOFs, utilizing non-toxic, biocompatible, metals and organic linkers in hydrothermal conditions. MOFs syntheses have been performed using Zn2+, Ca2+, Mg2+, or Fe3+ as the metal ion in combination with biocompatible organic linkers that are currently used as excipients, supplements, and drugs in pharmaceutical formulations. Preliminary results include single crystal formation of possible iron-maleicate, zinc-citrate, zinc-tricarballilate, and calcium-adipicate MOFs. Additionally, other attempted syntheses have lead to powder formation of possible magnesium-citrate, calcium-citrate, iron-fumarate, zinc-malicate, and calcium-dicarbozamide MOFs. Resulting crystals and powders are characterized utilizing techniques such as optical microscopy, Raman spectroscopy, powder X-ray diffraction (PXRD), and single crystal X-ray diffraction (SCXRD). Upon completion of the characterization, selected drug molecules will be encapsulated onto the porous bioMOFs. These bioMOFs will be tested for their efficacy in drug loading and delivery in vitro.

Chemistry Presenters: González Canales, Verónica M. Báez Colón, Mariangelie

Mentor: Ortiz-Marciales, Margarita

Title: Synthesis of 1- Benzazepines for Biological Research

Authors: Verónica González Canales (University of Puerto Rico at Humacao), Mariangelie Báez Colón (University of Puerto Rico at Humacao), Raiza Santiago Rosario (University of Puerto Rico at Humacao), Sandraliz Espinosa-díaz (University of Puerto Rico at Humacao), Margarita Ortiz-marciales (University of Puerto Rico at Humacao)

Abstract

Recent increase for multiple cases of neurodegenerative diseases with limited effective treatments has motivated us for the development of new drugs that can work as nicotinic acetylcholine agonists. Oximes and oxime ethers are used as convenient intermediates for the preparation of a variety of organic molecules, such as cyclic and acyclic anilines due to their convenient preparation from carbonyl compounds and their facile transformations to other functional groups. This organic compounds are used as intermediates for the synthesis of a variety of pharmaceutical products. Cyclic amino derivatives, such as 1-benzazepines, have been recently studied as relevant biologically active compounds and have gained interest in the treatment of neurodegenerative diseases, such as Alzheimer's and Parkinson. Our purposes is to develop new methods for the synthesis of cyclic amino 58

compounds from oxime ethers and to study their biological activity as potential therapeutic drugs for neurological disorders. We are interested in investigating convenient methods for the synthesis of new analogues of Galantamine, to use them as allosteric nicotinic receptors agonists. Previously, our laboratory developed an efficient method for the synthesis of 1-benzazepines by the reductive rearrangement of O-tert-butyldimethylsilyl oximes using boron triflouride and borane in THF under reflux conditions. Now, we have synthesized 7-methoxy-2,4,5-tetrahydro-1-benzazepine and 7,8- dimethoxy-2,4,5-tetrahydro-1-benzazepine and prepared new benzazepine analogues with different substituents at the nitrogen atom to further study their neurobiological an toxicological properties.

Chemistry Presenter: Gonzalez Ojeda, Indra

Mentor: Lopez Garriga, Juan

Title: Gelification of Lysozyme Under High Concentrations of Sulfhydric Acid (H2S) as an Alternative to the Formation of Amiloid Fibrils

Authors: Indra González Ojeda (UPR-Mayaguez), Juan López Garriga (UPR-Mayaguez)

Abstract

Amyloid fibrils are conformations of misfolded proteins with a stable ?-sheet structure. They are believed to be the main cause of neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Fibrillization can be initiated by applying extreme conditions of temperature and pH to a protein. It has been proven than by adding sulfhydric acid (H2S), hen egg white lysozyme (HEWL) amyloid fibers are inhibited (Rosario, 2014). This inhibition results in small spherical aggregates of unordered protein that exhibit almost no cytotoxicity. During this study the concentration of H2S in samples of HEWL was varied to explore the acid's effect on the resulting protein conformations. This was done by preparing vials containing a lysozyme solution with a concentration of 50mg/mL, 20% Acetic Acid and 0.1M NaCl. These samples were divided into four groups and a different ratio of lysozyme:H2S was added to each group. The ratios used were 1:0 (control), 1:1, 1:5, and 1:10. Afterwards, all the samples were placed in an oven at a temperature of 60°C for 48 hours. It was clear that the samples without H2S (1:0) were the only ones that showed definitive fibril formation, and the samples with the smallest concentration of H2S (1:1) yielded spherical aggregates similar to those expected in the inhibition. However, for the samples with higher concentrations of H2S (1:5, 1:10) a gelatinous structure was observed. This structure was subjected to various techniques of spectroscopy such as Raman and Fluorescence to characterize its properties. Therefore, the results indicate that the concentration of H2S influences the way in which the protein orders itself whilst undergoing fibrillation. The discovery of this gelification mechanism also opens the door to further research into the procedure responsible for fibril formation, and brings the possibility of applying these structures as both an industrial material and/or a therapy for amyloidosis. 59

Chemistry Presenters: Gonzalez Velez, Johalis Serrano Gonzalez, Juliannette

Mentor: Pena, Guido

Title: Ethanol Production and its Application as Fuel in a Four Cylinder Car

Authors: Johalis Gonzalez Velez (UPR Arecibo), Juliannette Serrano Gonzalez (UPR Arecibo), Wendifer Reyes (UPR Arecibo), Fabiola Liciaga Echevarria (UPR Arecibo), Adriana Adrover (UPR Arecibo)

Abstract

The objective of this investigation was, produce ethanol from molasses of cane and sugar cane juice by fermentation. Basically the fermentation process consist in using sugar from molasses cane and cane juice; making the right solutions in a fermenter and adding yeast in anaerobic conditions so we can get ethanol. At the end of the fermentation, distillation operation was use for get a high concentration of alcohol. Therefore the use of ethanol produced by the fermentation can be used for running a gasoline car. By this reason we develop this project with the vision of substitute the 5% of consume of gasoline in P.R. with ethanol, for light vehicle that works with gasoline that will be needing about 216 ML/y of ethanol. The terrain needed for planting sugar cane (use as molasses) for supplying the demand it would be of 56,568 hectares. We would able to make seven fermentations at 30° brix average obtaining 27.2L of alcohol at 82.48% volume/volume. This alcohol was proved in a Datsun 210 – 1982, making some modifications in the carburetor needles and advancing the time of ignition, we tested the combustion of alcohol running the car in the facilities of the University of Puerto Rico at Arecibo. The results was satisfactory. Other technic of adjustment will be done on the future.

Chemistry Presenter: González-Pérez, Maroly C.

Mentor: Rey, Rosamil

Title: Characterization of Fibers using Fourier Transform Infrared Spectroscopy

Authors: Maroly González Pérez (Inter American University of PR) 60

Abstract

The identification of fibers is of high importance in forensic science as it can yield trace evidence in a criminal case. Fourier Transform Infrared Spectroscopy (FT-IR) is a very powerful technique to characterize the chemical composition of natural and synthetic fibers, both organic and inorganic in nature. Using the ATR (Attenuated Total Reflectance) technique minimal sample preparation is required to perform an FTIR-microscopic measurement. The objectives for this research is analyzed and compare different fibers using ATR-FTIR. Eventually analyzing microscopic characteristics using Light Polarized Microscope will de perform in order to validate the method for fiber identification.

Chemistry Presenter: Graniela, Mya E.

Mentor: De Jesus-Echevarria, Maritza

Title: Volatile Composition of the Fresh, Dried and Smoked of Lippia dulcis Trev. by Headspace Solid Phase Micro-Extraction Coupled with GC/MS

Authors: Graniela Marty, Mya E. (UPR-Mayagüez), Negrón Ramos, Darisabel (UPR-Mayaguez), De Jesús-echevarría, Maritza* (UPR-Mayagüez)

Abstract

Lippia dulcis Trev. is a perennial plant that grows and bloom over the spring and summer. This herb is a fast growing, spreading plant from Central America and the Caribbean with sweet pungent odor, bears short spikes of small white flowers, and the leaves have curious and intensely sweet flavor. The volatile composition of the fresh and dried smoke was analyzed by gas chromatography coupled to mass spectrometry, GC/MS and headspace solid phase micro-extraction, HS/SPME. A total of 73 and 52 volatile compounds representing 83.6% and 80.8% representing of the totals quantum of volatile present in fresh leaves and seeds respectively were identified. The main characterized volatile components for leaves were alpha copaene and trans caryophyllene, delta-cadinene and for the seeds gamma 1-cadinene, trans caryophyllene and germacrene B. Due to the found uses of the Lippia dulcis as a bio insecticide an assay was conducted using ants insect and the smoke of the dried and fresh leaves were characterized. In the smoke the main volatile components were 6-methyl-5-hepten-2-one and 2- cyclohexen-1-one the decomposition compounds of the Lippia dulcis leaves, hernandulcin. Other monoterpene, aldehyde, phenols and furans and many toxicity compounds were found. The assay conducted using ants insect was successful.

Chemistry Presenter: Hall Laureano, Stephanie

Mentor: De Jesus, Marco A.

Title: Quantification of sulfonamide in water using Silver enclosed PDMS nano-composites as SERS substrates

Authors: Stephanie Hall (Universidad de Puerto Rico Recinto de Mayaguez), Hector I. Areizaga Martinez (Universidad de Puerto Rico Recinto de Mayaguez)

Abstract

Sulfonamides are antibiotics used to treat diseases to both humans and animals. However, these are partially metabolized and they may be accumulated in waste waters due to urine and excretion of the living organism that may have ingested them. In this study, surface enhanced Raman spectroscopy (SERS) was used to analyze 4-carboxybenzenesulfonamide. The substrate used for this method was an Ag/PDMS nano-composite. In addition, a sample translation technique (STT) was used to decrease the decomposition of the sample due to the constant irradiation of the laser beam. The characteristic bands obtained for the compound were found at 1600cm-1, ~1400cm^-1, ~1020-1190cm-1, and ~830cm-1 Raman shifts. The quantification of the sulfonamide was done by analyzing a set of standard solutions and graphing the concentrations versus the peak area of the most predominant Raman shift, 830cm-1. The standard curves obtained were not completely linear, which indicates that an error could've occurred in the preparation of the PDMS, the preparation of the standard solutions, the deposition of silver, or at the process of the SERS analysis.

Chemistry Presenter: Herdocia Lluberes, Claudia S.

Mentor: Nicolau, Eduardo

Title: Evaluation of Synthesized Nanohydroxyapatite-Nanocellulose Composites as Biocompatible Scaffolds for Applications in Bone Tissue Engineering

Authors: Claudia S. Herdocia-lluberes (Department of Biology, University of Puerto Rico, Rio Piedras Campus), Simara Laboy-lópez (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus), Stefannie Morales (Molecular Science Research Center, University of Puerto Rico), Tania J. Gonzalez-robles (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus), José A. González-feliciano (Molecular 62

Science Research Center, University of Puerto Rico), Eduardo Nicolau (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus)

Abstract

Basic calcium phosphate (BCP) crystals have been associated with many diseases due to their activation of signaling pathways that lead to their mineralization and deposition in intra-articular and periarticular locations in the bones. In this study, hydroxyapatite (HAp) has been placed in a polysaccharide network as a strategy to minimize this deposition. This research consisted of the evaluation of varying proportions of the polysaccharide network, cellulose nanocrystals (CNCs), and HAp synthesized via a simple sol-gel method. The resulting biocompatible composites were extensively characterized by means of thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potential, and scanning electron microscopy (SEM). It was found that an nHAp = CNC ratio presented greater homogeneity in the size and distribution of the nanoparticles without compromising the crystalline structure. Also, incorporation of bone morphogenetic protein 2 (BMP-2) was performed to evaluate the effects that this interaction would have in the constructs. Finally, the osteoblast cell (hFOB 1.19) viability assay was executed and it showed that all of the materials promoted greater cell proliferation while the nHAp > CNC proportion with the inclusion of the BMP-2 protein was the best composite for the purpose of this study.

Chemistry Presenter: Ingles, Natasha

Mentor: Pares-Matos, Elsie I.

Title: Human Serum Amyloid A: Expression Levels and Determination of New Protein Complexes using Crude Extracts of Induced THP-1 and HL-60 Cells

Authors: Natasha N. Inglés-martínez (University of Puerto Rico, Mayagüez), Elsie Parés-matos (University of Puerto Rico, Mayagüez)

Abstract

Serum Amyloid A (SAA) is one of the major acute phase proteins in humans. When inflammation occurs, expression levels could reach up to a 100-1000 fold increase. SAA loss of alfa-helix conformation during its expression peak is directly linked to secondary amyloidosis. Even though evidence indicates that this family of proteins has remained highly conserved, not much is known about its structure and interaction with other proteins within the cell. Due to their association with acute phase response, we assume that SAA proteins may have a regulatory role mediated through protein-protein interactions with their C- terminal domain, where it may recruit proteins involved in membrane signaling and transcription regulation. This study has two specific aims: 1) Identify the expression levels of SAA protein members in lipopolysaccharide, phorbol-12-myristate-13-acetate and dexamethasone induced THP-1 and HL-60 63

cells, and 2) Identify possible SAA interactions with other proteins using their crude protein extracts. The amount of SAA in THP-1 and HL-60 extracts was estimated by SDS-PAGE and Western blot. The formation of protein complexes with SAA will be determined by co-immunoprecipitation, and these bound proteins will be resolved by SDS-PAGE prior mass spectrometry analysis. To date, we are still working on the ideal conditions for SAA detection by Western blot. Knowing better the interactions of SAA with other cellular proteins can allow us to determine other unknown roles that SAA can play in mammalian cells, including human.

Chemistry Presenters: Laureano Otero, Ashley A López Feliciano, Génesis

Mentor: Ospina, Claudia

Title: Chemical Analysis of Brown Algae: Sargassum polyceratium and Stypopodium zonale

Authors: Claudia A. Ospina Millán (UPR-CAYEY), Ashley A. Laureano Otero (UPR-CAYEY), Génesis López Feliciano (UPR-CAYEY)

Abstract

Algae are known to possess biological properties such as antimicrobial, antibiotic, antifungal, inhibitor, UV radiation protection, etc. Sargassum polyceratium (S. polyceratium) and Stypopodium zonale (S. zonale) are brown algae that can be found in tropical and subtropical regions. The purpose of this study is to identify the chemical compounds responsible for the biological activity. The collection of the algae was in the beach Pozuelo at Guayama, Puerto Rico. These algae were dried and lyophilized to obtain a dry weight of 97.98 g and 150.0 g of S. polyceratium and S. zonale, respectively. It was macerated in a mixture of methylene chloride and methanol (1:1) to prepare the crude extract through vacuum filtration and concentrate. The final product of the extract of S. polyceratium and S. zonale has a weight of 0.901 g and 2.20 g, respectively. With the crude extract of each alga, a column chromatography was prepared in silica gel to obtain fractions that were analyzed by Nuclear Magnetic Resonance (NMR). Purification of these fractions is in process in order to identify the chemical compounds.

Chemistry Presenter: León Feliciano, Isannette N.

Mentor: Alamo Nole, Luis

Title: Effect of Cd(S,Te) quantum dots on the germination of Ocimum basilicum in liquid medium

Authors: Luis Alamo Nole (PCUPR), Isannette N. León Feliciano (PCUPR)

Abstract

The plant Ocimum basilicum "basil" has multiple uses not only in culinary and medicine but as well for research purposes. Basil and others plants have the ability to absorb heavy metals such as cadmium, zinc, mercury, etc. This property makes the plants be vulnerable to metal accumulation that can alter their germination and growth. The production of nanoparticles such as Quantum Dots (QDs) has risen over the last years due to their numerous properties and applications. Currently there are no discarding regulations for these nanomaterials and they can reach the water bodies. In this research Cd(S,Te) QDs were synthesized under microwave irradiation at different temperatures in aqueous phase. The nanomaterials were characterized by Ultraviolet-Visible spectrum (UV-Vis) and Photoluminescence (PL). Ocimum basilicum seeds were exposed to Cd(S,Te) QDs in liquid medium to evaluate the effect in the germination rates. Also, the seeds will be analyzed by Inductively Coupled Plasma (ICP) to determine the concentration of cadmium.

Chemistry Presenter: Lopez Llegus, Maria M.

Mentor: Santos-Santori, Lizette

Title: The effect of the combination of chlorzoxazone and dehydroepiandrosterone in CYP3A4 and CYP2E1.

Authors: María Milagors López Llegus (Pontifical Catholic University Of Puerto Rico), Lizette Santos Santori (Pontifical Catholic University Of Puerto Rico)

Abstract

The cytochrome P450 consists of hemeproteins that use a molecule of oxygen to catalyze many reactions. Chlorzoxazone is an analgesic muscle relaxant that is rapidly metabolized by the cytochrome P450 and produce 6-hydroxichlorzoxazone. This drug is a substrate for the isoenzyme 2E1 and 1A2 of the cytochrome P450 system. Dehydroepiandrosterone is a hormone produced by the adrenal gland, 65

sold as a dietary supplement, which induces the production of androgens and estrogens. Both drugs are related to cardiovascular diseases such as hypertension. Through the combination of chlorzoxazone and dehydroepiandrosterone the cytochrome P450 content, the enzyme activities and the changes in activity will be analyzed. The study was performed using Chinese Hamster Ovarian cells. Cell cultures were treated with each drug individually and a group with the drug combination. A control group was included. The content of cytochrome P450 in the drug combination cultures show less activity that the cultures with each drugs separately and the control groups. CYP2E1 showed more activity for the treated groups than the control group. Finally, CYP3A4 where less present in the treated groups than the control group. The assays that were used to determine the cytochrome activity included Bradford for protein total content, cytochrome P450 assays, P-nitrophenol hydroxylation assay, 7- etoxyresorufineactivity assay and N-dimethylase-erythromycin.

Chemistry Presenter: López-Nieves, Marjorie

Mentor: Cabrera, Carlos

Title: Electrochemical PCR for DNA Amplification

Authors: Marjorie López Nieves (University of Puerto Rico, Rio Piedras Campus), Nadja E. Solis Marcano (University of Puerto Rico, Rio Piedras Campus), Carlos R. Cabrera (University of Puerto Rico, Rio Piedras Campus)

Abstract

The analysis and detection of specific viruses, bacteria and parasites has important implications in the clinical and biotechnological sectors. Thus, the demand for the development of biosensors technology in the biomedical areas has increased over the last decade do to simple, fast, cost effective and easy diagnostic of diseases. Therefore, the concept of providing an in-hand analytical laboratory to the patients and doctors will potentially change and improve clinical practices. Presently, scientists have found that polymerase chain reaction (PCR) is improving patient care in the molecular laboratory through accuracy and convenient time results. This technology has a positive impact in patient care by delivering highly specific, sensitive and fast information to physicians in shorter timeframes. The purpose of this project is to develop a PCR biosensor for detection of microbial DNA to gain insights and to study the behavior of the specific DNA primers on the sensor platform and to test its reproducibility for detection of selective diseases. If the sample contains the disease specific primers in question, then the DNA sequence will be amplified through the PCR technique because we may identify and diagnose the disease by the use of electrochemical analysis. In order to evaluate whether the sample contains these specific DNA primers, the gold microelectrodes surface will be prepared, modified with solutions containing the DNA primers and amplified by the PCR technique. To detect effective DNA elongation impedimetric analysis will be performed and methods like gel electrophoresis and Atomic Force 66

Microscopy will be used to study the microelectrode gold surface and observe the behavior of DNA primers. If successful DNA elongation is observed then the PCR biosensor could be a useful tool in medical applications for the improvement of patient care.

Chemistry Presenter: Machine Rivera, Roger

Mentor: Ospina, Claudia

Title: Study of the Chemical Composition and Cytotoxic Properties of Puerto Rican plant Simarouba tulae

Authors: Roger Machín Rivera (University of Puerto Rico at Cayey)

Abstract

Puerto Rico contains a vast of endemic plants species that are not taxonomical recognized, or if they are, a chemical screening of this plant are unknown. Similar happens with the endemic plant Simarouba tulae, which happens to have cytotoxic properties interesting for cancer research. The Quassinoids are highly oxygenated terpenes and the responsible of the anticancer properties of the Simarouba species. Previous work shown, that the hexane extract of S. tulae is cytotoxic to T47D (breast) cancer cells. In order to know the metabolites that shown anticancer properties we need to purify the extract with the classic technique Column Chromatography. From past purifications a S2H2 bioactive fraction was obtained. Eleven subfractions from this fraction were obtained in silica gel column chromatography with 2% of methanol in chloroform. The last subfraction is now being purifying in silica gel column chromatography with 5% of methanol in methylene chloride. After obtain the new fractions a H1 & C13 –NMR analyses are realizing for study the signals of the compounds in the fractions. This analysis allows us to determinate where we can find the desire compounds, the Quassinoids. It is important to study the endemic plants because we can find new molecules that can be precursor for new treatments of harmful diseases, like this cases, cancer disease.

Chemistry Presenter: Martinez Adorno, Valerie

Mentor: Peña, Guido

Title: Production of Biodiesel from New and Used Vegetable Oil

Authors: Valerie Martínez Adorno (University of Puerto Rico at Arecibo), Glorivee González Mercado (University of Puerto Rico at Arecibo), María A. López Aquino (University of Puerto Rico at Arecibo), Karla M. Rosario Alvarez (University of Puerto Rico at Arecibo), Evalerie K. Ortiz Reyes (University of Puerto Rico at Arecibo)

Abstract

PRODUCTION OF BIODIESEL FROM NEW AND USED VEGETABLE OIL

ABSTRACT

The purpose of this research is to demonstrate that biodiesel can be produced from new and used vegetable oil, without relying on fossil fuel. Biodiesel is prepared by transesterification reaction using a reactor of controlled agitation, the oil and sodium methoxide mixture, maintaining the temperature at 48 ° C for a period of 50 minutes. By operation of decantation, the biodiesel is separated of the glycerin, then subjected to various washing steps with distilled water to remove any impurities. The percentage of average yield for the new oil was 85%, while for the oil used was 82%. The average viscosity for biodiesel from vegetable oil was 6.12 g / cm-s, this indicates that it is within range of the industrial biodiesel. The biodiesel produced was tested in a Ford 250 pickup truck and digger owned by the University of Puerto Rico Arecibo Campus, with an excellent performance.

Chemistry Presenter: Marti•nez Marquez, Francisco Roberto

Mentor: Colon, Jorge

Title: Intercalation and chemical characterization of two neurological agents in zirconium phosphate layers for drug delivery application

Authors: Francisco R. Martínez (UPR-RIO PIEDRAS), Bárbara Casañas (UPR-RIO PIEDRAS), Jorge L. Colón (UPR-RIO PIEDRAS), José Agosto (UPR-RIO PIEDRAS), Tugrul Giray (UPR-RIO PIEDRAS) 68

Abstract

Zirconium(IV) bis(monohydrogen phosphate) hexahydrate is a highly hydrated phase of zirconium phosphate (ZrP), known as the 10.3 Å phase. ZrP is a layered inorganic compound and throughout the years many applications have been developed based on this material. The purpose of this research involved the intercalation and characterization of both dopamine (DA) and carbamazepine (CBZ), into the 10.3 Å phase of ZrP to study the use of the layered material as a potential host for drug delivery of neurological agents. One of the most important neurotransmitters in the brain is dopamine. While carbamazepine functions as an anticonvulsant and mood stabilizing drug to treat various neurodegenerative diseases. One of the major problems about DA and CBZ is that they are photosensitive and easily degraded. The intercalation into ZrP layers would provide a stable environment that will protect and help deliver both compounds to their corresponding targets. The intercalation procedure of DA was performed at a pH level equal to 8 at a drug:ZrP molar ratio of 5:1 in aqueous solution. Upon intercalation the X-ray powder diffraction pattern of the product indicated that a new expanded phase of ZrP was obtained with an interlayer distance of 10.5 Å. The intercalation procedure for CBZ was performed as well at a molar ratio of 5:1. Upon intercalation a new expanded phase of ZrP was obtained with an interlayer distance of 10.0 Å. These results suggest that for both agents ZrP layers are a suitable material for the intercalation of these compounds. Fourier Transform- Infrared spectroscopy (FTIR) results of the intercalated products suggest that the chemical nature of CBZ and DA are not altered within ZrP upon intercalation. In addition, UV-vis spectrophotometry spectra for CBZ upon intercalation also shows similar spectra to that of the non-intercalated complex. Further studies will corroborate if ZrP is a suitable material for the intercalation of both dopamine and carbamazepine. The characterization of both compound-intercalated products using FTIR, UV-vis spectrophotometry, and energy dispersive X-ray spectroscopy (EDS) will be presented as well.

Chemistry Presenters: Martinez Vazquez, Robby L. Alicea Valle, Everick C.

Mentor: Rodriguez-Berrios, Raul

Title: Studies Toward The Development Of A Short-Step Synthesis Of Functionalized Allylic Alcohols Methodology Based On The Cleavage Of Epoxides With Oxygenated Alkenyl Aluminum And Grignard Derivatives

Authors: Raul R. Rodríguez Berrios (PCUPR), Robby L. Martínez Vázquez (PCUPR), Everick C. Alicea Valle (PCUPR), Christian Hernández Ayala (PCUPR), Alexis Franceschi Galarza (PCUPR), Stephanie Pérez Ruiz (PCUPR)

Abstract 69

Several methods for the synthesis of polyketide fragments have been developed, but the epoxide cleavage with carbon nucleophiles for such synthesis has become a useful approach. In order to contribute to this area, we have proposed the development of a short-step methodology for the construction of polyketide chains. This consist of either, hydroalumination or carbometalation of propargyl alcohol to afford the alkenyl aluminum or Grignard derivative which mediate the ring opening of terminal epoxides to the construction of chiral allylic alcohols as key intermediates in the synthesis. We have explored a two-step procedure, which incorporate 1) the hydroalumination-iodination of propargyl alcohols using LiAlH4 and DIBAL-H to obtain the corresponding cis- and trans-vinyl iodides in moderate to good yields (60-80%), 2) the subsequent preparation of the alkenyl alanates reagents to cleavage the terminal epoxides will afford the chiral cis-and trans-allylic alcohols. Alternatively, a one- step procedure has been also proposed and explored. This novel procedure is based on the in situ hydroalumination with DIBAL-H in hexanes of propargyl alcohol to afford the E-allylic alcohol. In addition, we have incorporate the Zr-catalyzed carbometalumination of alkynes and subsequent epoxide cleavage step to form the corresponding E-allylic alcohol. Furthermore, we will explore the reactivity of copper-catalyzed carbomagnesiation procedure of propargyl alcohols to produce an alkenyl Grignard intermediate toward the cleavage of various terminal epoxides to obtain the complementary Z-allylic alcohol. These procedures will demonstrate the utility of our new epoxide-cleavage methodology mediated by oxygenated alkenyl alanates and Grignard reagents to the enantio- and regioselective construction of polypropionate and polyols fragments in few steps. This will expand the applicability of our methodology for the synthesis of polyketide natural products and present potential opportunities for increase or modified biological and therapeutic activity.

Chemistry Presenter: Mayorga, Isabel

Mentor: Nicolau, Eduardo

Title: Development of impedimetric aptasensor for the analytical determination of inorganic arsenic

Authors: Eduardo Nicolau (University of Puerto Rico-Rio Piedras), Edwin O. Ortiz Quiles (University of Puerto Rico-Rio Piedras), Isabel Mayorga Pérez (University of Puerto Rico- Rio Piedras), Ana Rivera Rivera (University of Puerto Rico-Rio Piedras)

Abstract

The reliable detection of toxic substances in the environment is critical for the design and implementation of preventive public health programs. Several toxic substances are known to be present in the environment, from both natural and anthropogenic sources. Among these, inorganic arsenic (e.g. As3+) in surface and groundwater has attracted much attention during the last decade due to its lethal effects on humans. Therefore, different strategies had been employed to detect arsenic, including 70

aptamers-based biosensors. Aptamers are oligonucleotides that have emerged as an innovative sensing tool due to their high affinity and specificity towards specific targets. To test the aptamers interaction with arsenic, Ars-3 were immobilized on gold electrodes through Au–S interaction. Afterwards, the modified electrode was submerged in a sodium arsenite solution. This process is expected to produce strong interactions between arsenic ions and the immobilized aptamers. Electrochemical techniques, such as Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were employed to investigate and elucidate the capacity of the system for sensing applications. EIS changes in resistance provided insight about the surface interactions of the electrodes. An increment in resistance is expected as more arsenic trioxide is added to the system. The recognition of small molecules by the aptamer- based electrode resulted in a larger electron transfer resistance for the redox pair probe used in the electrochemical setup. The designed aptasensor will be used to detect arsenic levels in well-drinking waters.

Chemistry Presenter: Medina, Nataniel

Mentor: Pinero, Dalice

Title: Bulk synthesis of TCNQ radical anion salts and derivatives: Development of Paramagnetic Linkers

Authors: Nataniel Medina Berríos (Univeristy of Puerto Rico Río Piedras Campus), Gellyz González Díaz (Univeristy of Puerto Rico Río Piedras Campus), Dalice Piñero Cruz (Univeristy of Puerto Rico Río Piedras Campus)

Abstract

TCNQ, 7,7,8,8-tetracyanoquinodimethane, is an organic electron accepting molecule considered to be a potential building block for the development of more efficient supramolecular magnets. It has the ability to form many powerful semiconductors with a large number of counter cations. In this work, four previously reported methods for the bulk synthesis of TCNQ radical anion salts were analyzed with the objective of determining the most adequate route for synthesizing TCNQ radical anion salts: complexation of TCNQ with nickel in a water sensitive reaction, electrochemical reduction, synthesis of alkali-TCNQ salts via CVD in textiles, and reduction of TCNQ in a reaction with 1,10-phenanthroline and hydroquinone. We have succeeded in identifying an efficient route to reduce TCNQ in bulks quickly applying the Chemical Vapor Deposition technique. The aim is to synthesize TCNQ radical anion salts in bulk quantities for the development of new paramagnetic linkers with greater magnetic response.

Chemistry Presenter: Mendez Olivencia, Amelines

Mentor: Pares-Matos, Elsie I.

Title: Expression and Isolation of rFAP1 (short) in Two Prokaryotic Systems

Authors: Amelinés Méndez Olivencia (UPR-MAYAGUEZ), Elsie I. Pares-matos (UPR-MAYAGUEZ)

Abstract

FAP1 is a protein originally found in Saccharomyces cerevisiae. Recent studies have demonstrated that this protein competes with rapamycin, an immunosuppressive drug that prevents rejection in organ transplants, for binding to FKBP12. The long-term goal of this project is to study the interactions of FAP1 with other proteins in yeast, but first, an antibody reactive to FAP1 is required. Thus, for the synthesis of an in house antibody raised against yFAP1, a plasmid containing the fap1 gene was cloned in BL- 21C43(DE3)pLysS+ and KRX, two strains of E. coli. The objective here is to determine which of these two E. coli strains is capable to produce more recombinant protein. In a previous work performed by another undergraduate student, transformants of BL-21C43(DE3)pLysS+ were induced with IPTG, but the presence of rFAP1 in the lysates was not observed with SDS-PAGE. To solve this problem, the experiment was repeated and inclusion bodies were now solubilized in order to determine if the expressed protein has been trapped as an insoluble complex. Our results have shown presence of rFAP1 in the lysates of BL-21C43(DE3)pLysS+, but not in KRX. In addition, after solubilization of their inclusions bodies, no presence of rFAP1 was observed.

Chemistry Presenter: Millan Serrano, Nathania

Mentor: De Jesus, Walleska

Title: Alpinia zerumbet as antibacterial and antifungal agent

Authors: Nathania Millanserrano (UPR-Aguadilla), Edwin Lopez (UPR-Aguadilla), Angelica Tomassini (UPR-Aguadilla)

Abstract

The bacterial strains resistant to antibiotics and the appearance of strains with low susceptibility to antibiotics are continuously increasing. Alpinia zerumbet is a species of perennial ginger plant which is native to the eastern of Asia, and that has a long history of medicinal use. The chemical composition of a plant may vary depending on their origin, due to environmental changes to which it is exposed, having 72

phenological and chemical evolution. It is our main interest to measure the antibacterial and antifungal activities of the components extracted from the leaves from A. Zerumbet, collected in the west region of Puerto Rico. The ethanolic extract was prepared using the reflux technique, and concentrated by rotoevaporation. The extract was used to test the antibacterial activity by the disk diffusion method using Mueller Hinton agar. The bacterial strains used were: (Gram positive) Staphylococcus epidermis, Enterococcus faecalis, and (Gram negative) Alcaligene faecalis, Escherichia coli, Enterobacter aerogenes, Micrococcus roseus, and Proteus mirabilis. The ethanolic extract was tested for their antifungal potential against the species Fusarium, Penincillium notatum, and Aspergillus niger. Preliminary results showed an average inhibition zone with diameters of 1.03cm, 0.53cm, 1.16cm, and 0.73cm for S. epidermis, P. mirabilis, M. roseus, and A. faecalis, respectively. The antibacterial activity of the A. Zerumbet is due to the presence of high phenolic content on the leaf, which may serve for human nutrition and health. These studies will help in the future to use this plant against bacterial and fungal infections.

Chemistry Presenter: Molina Villarino, Andrés

Mentor: Guadalupe, Ana

Title: Electrochemical Studies of Ferrocenyl Chalcones Immobilized in Nafion®

Authors: Andrés Molina Villarino (Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Puerto Rico), Juan C. Aponte Santini (Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Puerto Rico), Ingrid Montes González, Ph.d. (Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Puerto Rico), Ana R. Guadalupe Quiñones, Ph.d. (Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Puerto Rico)

Abstract

Bacteria and other types of microbes growing on surfaces are sources of biological contamination and infectious diseases, and thus a health hazard, especially in health-related scenarios such as hospitals, day care centers and elderly's home care. To address this problem and prevent infections, coatings containing biologically active materials that function as antimicrobial agents can be developed to inhibit or kill microbes at the surfaces of interest. Some commonly studied materials for this purpose include inorganic species such as metals (e.g. Ag, Pt, Fe) or metal oxides such as TiO2, although some biologically active organic compounds have been the subject of study. In this project, we take advantage of some organometallic compounds and the electrochemical properties that relate to their biological activity, to assess the possibility of producing antimicrobial coatings that will arrest microbial growth. We propose the immobilization of a series of biologically active Ferrocenyl Chalcones in Nafion®. These compounds have inherent biological activity, and in many cases, this activity is directly related to the electrochemical 73

ability of the ferrocene moiety to produce hydroxyl radicals that can damage DNA. We compare the compounds' electrochemical properties when immobilized in Nafion® versus those exhibited in solution, to see if they hold when immobilized in a coating. With this data, along with other chemical and physical parameters, we expect to gather information about the suitability of these materials for the intended purposes. This work will contribute to expanding the library of options of available materials for antimicrobial coatings.

Chemistry Presenter: Morales Ortiz, Kathleen

Mentor: Nicolau, Eduardo

Title: Surface modification of cellulose nanocrystals by TEMPO-mediated oxidation for applications in water remediation

Authors: Kathleen Morales Ortiz (UPR-Rio Piedras), Jairo Herrera Morales (UPR-Rio Piedras), Eduardo Nicolau López (UPR-Rio Piedras)

Abstract

Emerging contaminants directly impact human health by polluting water supplies, however, the specific consequences are still unknown. To address this environmental concern, different strategies suggest the use of biomaterials capable of adsorbing emerging contaminants (e.g. pharmaceuticals, personal care products, and metal nanoparticles). These biomaterials must possess properties such as high adsorption capacity, durability, and can be easily modified. In this sense, cellulose nanocrystals (CNCs) have a great potential for water remediation since they are a highly abundant biopolymer, stable, biocompatible, and relatively renewable material. Furthermore, CNCs have a high surface area with abundant hydroxyl groups which can be functionalized to capture specific contaminants. Chemical oxidation is commonly used to transform these hydroxyl groups into carboxyl functional groups. This modification facilitates a further derivatization of cellulose functionalities to increase the interactions with specific contaminants. Accordingly, we performed a surface modification of the CNCs using TEMPO-mediated oxidation. The CNCs and modified CNCs were characterized using FTIR, DLS, Raman, XRD, TGA, SEM, and Z-potential analysis. Results confirmed CNCs was successfully oxidized. In addition, an analysis correlating the molar ratio of the reagents and the degree of oxidation of the CNCs was done.

Chemistry Presenter: Munet Colon, Charlene

Mentor: Tinoco, Arthur

Title: Improving the Solubility and Cytotoxicity of Titanium(IV) deferasirox Complexes for Anticancer Application

Authors: Charlene Munet-colon (University of Puerto Rico, Rio Piedras Campus), Sergio A. Loza- rosas (University of Puerto Rico, Rio Piedras Campus), Aleannette Lopez (University of Puerto Rico, Rio Piedras Campus), Arthur D. Tinoco (University of Puerto Rico, Rio Piedras Campus)

Abstract

Titanium (IV) complexes have excellent potential for anticancer therapeutic application. Our strategy is to form Ti(IV) complexes with high affinity Fe(III) chelating ligands. These ligands are proposed to stabilize Ti(IV) for successful travel through blood but to facilitate the release of the metal into cancer cells, in exchange for Fe(III), to attack at intracellular sites. One such ligand is deferasirox, an FDA approved iron chelator that is currently used for iron overload disease. This is a tridentate ligand. The Ti(IV) complex of this ligand, Ti(deferasirox)2, and its derivative BHPT, Ti(BHPT)2 demonstrate high cytotoxicity against human lung cell lines A549 and MRC5. For this study the objective was to evaluate approaches to improve the cytotoxicity of these complexes by investigating the influence of the protein transporter serum albumin on the solubility of these complexes and by coordinating a reactive oxygen species on the Ti(IV) center without loss of the Fe(III) chelator. The Ti(BHPT)2 complex is poorly soluble due to its hydrophobic periphery and improvement of its solubility was sought by interacting the complex with serum albumin, which is known to solubilize and transport the highly hydrophobic fatty acids. The solubility study demonstrated that serum albumin did not improve the compound solubility nor have any appreciable binding affinity to the complex. The same was true for Ti(deferasirox)2. We are currently working to prepare a peroxo derivative of the Ti(deferasirox)2 and Ti(BHPT)2 complexes. These derivatives are expected to have a mixed ligation in the form of Ti(O2)(iron chelator). The hypothesis is that the coordination of the iron chelator will weaken the O-O bond of the peroxo ligand enabling it to become a highly active reactive oxygen species. Preliminary coordination chemistry studies suggest initial success in the synthesis.

Chemistry Presenter: Muñiz Rivera, Arnaldo

Mentor: Pares-Matos, Elsie I.

Title: Identifying the best micro flow conditions in the first prototype of a VEGF biosensor

Authors: Dr. Elsie I. Parés-matos (UPR-Mayaguez), Dr. Pedro J. Resto Irizarry (UPR-Mayaguez), Arnaldo Muñiz Rivera (UPR-Mayaguez), Luis F. Anaya Escobar (UPR-Mayaguez)

Abstract

A biosensor is still on development for the isolation of the vascular endothelial growth factor (VEGF) protein. This protein acts on endothelial cells and has various effects, including mediating increased vascular permeability. The biosensor is an analytical device, for the detection of an analyte. This can provide cost-effective, easy-to-use, sensitive and a highly accurate detection. The material used for this biosensor was polydemethylsiloxane (PDMS), since it is easy to use, to fabricate and to test microfluidic systems rapidly. For the model, made with PDMS, three layers or compartments will be included where each one has an exit for insertions of tubings and with a 90? channel distance from each other.

Chemistry Presenters: Muñoz Padilla, José E. Medina, Nataniel

Mentor: Pinero, Dalice

Title: Bulk Synthesis of Coronene: Developing the Shortest and Easiest Synthetic Route

Authors: José E. Muñoz (UPR-RIO PIEDRAS), Dalice Piñero (UPR-RIO PIEDRAS), Nataniel Medina (UPR-RIO PIEDRAS)

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are compounds that have large ?-conjugated systems and hence are often regarded as promising, yet challenging, building blocks for the construction of organic semiconducting materials. Coronene, a yellow powder PAHs that consist of six benzenes, has a unique electronic structure due to the perfect delocalization of the aromaticity among the six outer ring. In comparison to other smaller ?-conjugated systems molecules, coronene has shown to be useful for the film formation and crystallization of other conjugated molecules due to it six-fold symmetry. In this 76

work, in order to upscale and develop an efficient synthesis of coronene, a novel synthetic route via acylation without the use of a metallic catalyst is proposed.

Chemistry Presenters: Negrón García, Michelle Montañez Barreto, Gardimar

Mentor: Ferrer Torres, Edmy

Title: Effects of adrenaline and silver nanoparticles exposure on Daphnia Magna

Authors: Michelle Negron Garcia (Interamerican University- Ponce), Gardimar Montanez Barreto (Interamerican University- Ponce), Kelvin Cintron Silva (Interamerican University- Ponce), Jose J. Colon Rodriguez (Interamerican University- Ponce)

Abstract

EFFECTS OF ADRENALINE AND SILVER NANOPARTICLES EXPOSURE ON DAPHNIA MAGNA

Cintrón Silva, Kelvin1; Colón Rodríguez, José1; Negrón García, Michelle1; Montañez Barreto, Gardimar1.

[email protected]

1Interamerican University of P.R., Ponce Campus

Keywords: Nano/Materials, Toxicology, Environmental, Biomedical.

Abstract

Daphnia magna is used to conduct a bioassay in order to explore the effect of adrenaline combined with silver nanoparticles based on the time of exposure with the drug. The properties of silver nanoparticles are suitable for modifying some drugs in the medical industry. Daphnia magna are often used as a standard species for analysis of toxicity due to their susceptibility. Our work is based on short-term exposure studies of silver nanoparticles and adrenaline drug effects on Daphnia Magna, that are particularly useful due to their short lifespan and reproductive capacity. Their heart rate and the time of mortality are monitored. The synthesis of the silver nanoparticles was successfully achieve using AgNO3 and NaBH4 in a reduction reaction. The nanoparticles was characterized using optical studies and dynamic light scattering (DLS) techniques. The silver nanoparticles primary size is 40.3 nm. Three variables were studied: volume, heartbeat and survival time. The results were: control (15 µl, 92 hb and 1 h), adrenaline drug (120 µl, 120 hb and 14 min), silver nanoparticles (150 µl, 150 hb and 19 min), and drug + silver nanoparticles (450 µl, 106 hb and 26 min). This data shows the inhibitory effects of the action of the drug and silver nanoparticles and how it increases the survival time of the specimen.

Chemistry Presenter: Nieves Santiago, Liz A.

Mentor: Colon, Jorge

Title: Surface nodificatuon of doxorubicin intercakated into nanoparticles of zirconium phosphate

Authors: Liz Ariana Nieves Santiago (UPR Rio Piedras), Julissa González (UPR Rio Piedras), Jorge Colón (UPR Rio Piedras)

Abstract

Cancer is one of the leading causes of death worldwide. In 2014, 14.5 million were diagnosed with cancer in U.S.A. Therefore, it has brought many repercussions in our society and this is why there has been much research on this topic. One of the most widely used anti-cancer drugs is doxorubicin. This agent acts by insertion between the bases of the DNA double helix inhibiting the Topoisomerase II binding, which unwind DNA during the transcription process. In addition, doxorubicin forms free radical intermediates which create superoxide ions that can enter the cells' membrane and block the G1 phase in the cell cycle inducing apoptosis. Although doxorubicin is a very effective anticancer drug, its also known for its toxic side effects that could lead to death. Inorganic layered compounds, such as zirconium phosphate (ZrP), are chemical and thermally stable materials that can serve as hosts of bioactive species, such as doxorubicin. The purpose of our research is the intercalation of doxorubicin into ZrP layers to produce a highly effective drug delivery system. We intend to modify the surface of doxorubicin intercalated in ZrP with monomethyl- polyethylene glycol- monophosphate (m-PEG-PO3) as a way to improve the biocompatibility of the nanoparticle. The intercalation procedure of doxorubicin (Doxo) into ZrP layers was performed at a 5:1 Doxo:ZrP molar ratio in water. Surface modification of Doxo:ZrP consists in the addition of a Zr(IV) layer followed by m-PEG-PO3 bonding to the tetravalent metal ion layer. The characterization by X-Ray powder diffraction of the Doxo:ZrP intercalated product and the m-PEG-PO3:Zr@Doxo:ZrP surface modification product showed that both products have an interlayer distance of ca. 20 Å. Results from 31P NMR and IR spectroscopies and SEM-EDX will be presented.

Chemistry Presenter: Nieves Santiago, Ricardo

Mentor: Santiago, MitkEl

Title: Synthesis of Lead Selenide Magic-Cluster Modified With Benzoic Acid Ligand for Solar Energy Harvesting Applications

Authors: Ricardo Nieves Santiago (UMET), Jadiel Colon Perez (UMET), Mitkel Santiago-berríos (UMET)

Abstract

Lead selenide quantum dots (PbSe QDs) are semiconductor nanoparticles with energy absorption in the near IR to UV electromagnetic spectrum. One of the attractive properties of PbSe QDs is that the particle size can be accurately controlled to enhance performance and stability for applications in energy harvesting devices. Recent efforts of PbSe synthesis have yielded particles that allowed a 6% solar energy conversion efficiency which kindled a race to optimize and develop better synthesis methods. Magic sized clusters PbSe synthesis using oleic acid as ligand, have reported particles of approximately bsorption peak at 1400nm consistent with previous results. Adjustments in synthesis temperature and nanocrystal growth and nucleation temperature produced a broad 800nm absorption peak and decreased particle size. In this presentation, we will present preliminary data, which shows the complete characterization of PbSe Magic Cluster modified with BA. Preliminary results of this material tested in a photoelectrochemical cell showed a 0.05% increase in a dye sensitized solar cell configuration.

Chemistry Presenter: Olmeda-Viera, Natalia N.

Mentor: Tremont, Rolando

Title: Study of Gold Surface Modified with Acrylamide: Electrochemical Studies and Surface Analysis

Authors: Natalia Olmeda-viera (University of Puerto Rico-Humacao), Rolando Tremont (University of Puerto Rico-Humacao)

Abstract

Cancer is probably one of the most studied diseases around the world, it can be caused by natural or external reasons such as the exposition or consume of some products. Recently, throughout a research investigation a compound from the amides group, acrylamide, was found to be a potential cancer agent. 79

Acrylamide is utilized by industries, but also found in components of cigarettes and in common food prepared in high temperatures, such as fried potatoes, baked food, and others. The purpose of this investigation is to create an electrochemical sensor that allows the immediate detection of acrylamide on daily consumed foods. During the first stage of this project an electrochemical method has been optimized for the cleansing of gold surface electrodes using sulfuric acid (1.00M) applying the "Cyclic voltammetry" technique. Potassium ferricyanide (III) solution (2.5mM) was utilized to verify the cleansing made to the surface of the gold electrode before its modification. After the successful corroboration of the clean surface, an alcoholic solution of 3-mercapto-1-propanol (3-MP, 2.5mM) was utilized to modify the surface for 24 hours. Electrochemistry technique was then applied to the modified surface in the Potassium ferricyanide (III) solution to corroborate the modification. The next stage of this project is to analyze the electrochemical behavior of the acrylamide over the clean surface of the gold electrode and then over the modified surface of gold in 3-MP. FT-IR Spectrometry analysis will be utilized to corroborate the modification of the gold electrode and to study the interactions of the 3-MP with acrylamide.

Chemistry Presenter: Ortiz, Lilliana

Mentor: Oyola, Rolando

Title: "The Photophysical Properties of a Borazine Derivarive"

Authors: Rolando Oyola Martinez (UPRH), Margarita Ortiz Marciales (UPRH), Lilliana I. Ortiz Rodriguez (UPRH), Luis A. Ortiz Rodriguez (UPRH)

Abstract

Borazine derivatives (BD) are multifunctional and thermally stable materials with high electron and moderate hole mobilities for applications in electroluminescent devices, as gasoline additives, polymerization catalyst and as neutron detectors. This work is focused on the determination of the photophysical properties of a borazine derivative with formula C18H12B3N3O3, a derivative of 2- aminophenol. To fulfill this objective, we will use spectroscopic techniques, including UV-Vis, and fluorescence. UV-Vis spectroscopy will be used to determine absorption cross sections of the BD in different solvents, such as acetonitrile, dimethyl sulfoxide and methanol. Fluorescence spectroscopy will be used to measure the intrinsic fluorescence quantum yield (?_F^BD). The? ??_F^BD obtained where: 0.012 ± (8%) for MeCN, 0.0050 ± (10%) for DMSO, and 0.0080 ± (10%) for MeOH. These measurements are useful for obtaining a complete scope of the properties of this compound in different microenvironments. More importantly, these measurements can help us to predict the potential uses of the BD for possible optoelectronic applications.

Chemistry Presenters: Ortiz Castillo, Stephanie N. Bas, Jesbaniris

Mentor: Pinero, Dalice

Title: Synthesis of MRI contrast agents: Designing new ligands for the coordination of paramagnetic transition metal ions

Authors: Stephanie Ortiz (UPR-RIO PIEDRAS), Jesbaniris Bas (UPR-RIO PIEDRAS), Alexis Guzman (UPR-RIO PIEDRAS), Kristian Calderon (UPR-RIO PIEDRAS), Priscila Rodriguez (UPR-RIO PIEDRAS), Oliver Pichardo (Escuela Bilingüe Padre Rufo)

Abstract

The medical diagnosis tool of Magnetic Resonance Imaging (MRI) uses in nearly 30% of the contrast agents to produce high quality resolution images for assessing areas of interest in the body. Gadolinium (Gd) chelates are widely popular as orally or intravenously contrast agents because of their effectiveness in enhancing the images' contrast. However, there may be health risks associated to the toxicity of the Gd3+ cation. Our aim is to synthesize a non-gadolinium based contrast agent using other transitional metal ions that can have similar effectiveness but less cytotoxicity. To achieve this goal, we have synthesized a novel ligand from dithiolenes called dmit-4,5-acac in order to form metal complexes with the following transitional metals: Mn(II), Fe(II), and Co(II). Herein, we present their effectiveness to alter the relaxation times of water protons in an aqueous/organic medium. T1 measurements of Gd(DTPA) and Gd(NO3)3 from 0.2mM to 1.0 mM solutions were taken in MeCN/H2O. The results of their T1 values will be presented in comparison to the other metal ions solutions with equivalent molarities. In addition, it will be presented the new developments in the synthesis of dithiolenes ligands from amino acids and pyrazole functional groups to provide more coordination sites for anchoring multiple paramagnetic transition metals. [1-2]

References:

[1] Maurice, M.; Goergen, S.; Gadolinium Contrast Medium (MRI contrast agents). http://www.insideradiology.com.au/pages/view.php?T_id=38 (accessed August 2014).

[2] Zhang, Q.; Gorden, J. D.; Beyers, R. J.; Goldsmith, C. R. Manganese (II)- Containing MRI Contrast Agent Employing a Neutral and Non-Macrocyclic Ligand. Inorg. Chem. 2011, 50, 9365.

Chemistry Presenter: Ortiz Rodriguez, Angel

Mentor: Cabrera, Carlos

Title: Electrochemistry

Authors: Angel Manuel Ortiz Rodriguez (UPR-Rio Piedras), Luis E. Betancourt De Leon (UPR-Rio Piedras), Carlos R. Cabrera (UPR-Rio Piedras)

Abstract

With the introduction of fuel cells catalysts for energy conversion, the science community has shown a particular interest in the use of this mechanism for the future, instead of the squandering of fossil fuels resources which leads to environmental and health complications. The aim of this investigation is to synthesize an efficient catalyst for ethanol oxidation in alkaline media with minimal metal loading using an innovative electrodeposition technique called Rotating Disk Slurry Electrodeposition (RoDSE). The RoDSE method to obtain highly dispersed Au nanoparticles does not require the use of a reducing agent or surfactant to deposit metal nanoparticles on a carbonaceous support and the noble-metal loading can be modified by the addition of metal precursor volume. This technique was employed to obtain Au nanoparticles dispersed on a highly conductive carbonaceous support for ethanol electro-oxidation in alkaline media. This study focuses on electrodepositing Au NP on Vulcan XC-72R using different electrolyte media: H¬2SO4, KCl and KOH. The media used for electrodeposition determined the physical and electrochemical properties of our catalyst, showing a higher activity using alkaline pH as confirmed by cyclic voltammetry and chronoamperometry techniques. The amount of electrodeposited Au on the support was corroborated by ICP-AES. Particle size and specific Au crystal facets were determined by X- Ray Diffraction. TEM showed differences in terms of agglomeration and particle size as a function of different electrolyte media. Surface area analysis of the Au NP was performed using the associated cathodic stripping of the Au-OH species.

Chemistry Presenter: Ortiz Rodríguez, Luis A.

Mentor: Oyola, Rolando

Title: Direct Measurement of the Singlet Oxygen Quantum Yield of 6-Thioguanosine

Authors: Luis A. Ortiz-rodríguez (Universidad de Puerto Rico-Humacao, Biology Department), Marvin Pollum (Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University), Steffen Jockusch (Department of Chemistry, Columbia 82

University), Carlos Crespo-hernández (Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University)

Abstract

Thiopurines have been prescribed as a treatment for cancers, chronic inflammatory diseases, and autoimmune diseases for over five decades. These drugs are metabolized to the nucleoside analogue, 6- thioguanosine (6tGuo), which is subsequently incorporated into the DNA of proliferating cells. While this metabolic activity makes thiopurines useful as pharmaceuticals, recently the long-term use of these drugs has been associated with up to a 200-fold increase in the incidence of skin cancer. In contrast to the natural DNA bases, thiopurines and their metabolites have the ability to absorb UVA radiation (320 to 400 nm). This is the major type of UV radiation reaching the Earth's surface and is able to penetrate deep into the replicating dermal layers of the skin. Earlier works have shown that 6tGuo acts as a dangerous photosensitizer, causing DNA damage upon UVA exposure and eventually leading to mutations and skin cancer formation. Surprisingly, the mechanism by which thiopurines induce these mutagenic responses remains unclear. In an effort to better understand the photosensitization mechanism of 6tGuo, we report a detailed kinetic investigation of this metabolite based on advanced photophysical and photochemical techniques. In particular, previous reports suggest that the mutagenicity of 6tGuo may be mediated by its ability to efficiently form the reactive oxygen species, singlet oxygen. Significantly, our re-evaluation of 6tGuo has revealed a singlet oxygen quantum yield more than fourfold lower than that previously reported under similar conditions (13% vs 55%). The potential implications of this new finding will be discussed.

Chemistry Presenters: Padín López, Arlyn V. Mendoza Soto, David G.

Mentor: De Jesus, Walleska

Title: Antioxidant capacity and polyphenol content of Alpinia zerumbet extracts in Puerto Rico

Authors: Arlyn V. Padín López (University of Puerto Rico-Aguadilla Campus), David G. Mendoza Soto (University of Puerto Rico-Aguadilla Campus), Melanie Z. Rodríguez Rivera (University of Puerto Rico-Aguadilla Campus)

Abstract

Reactive oxygen species (ROS) are mostly free radicals generated by normal metabolism of oxygen. ROS can cause oxidative stress, due to its excessive accumulation in cells, or to decreased antioxidant capacity of the latter. To counteract or minimize the effects of ROS, cells use antioxidants. These molecules prevent chain reactions of free radicals to occur in cells, by stabilizing them. One of the most 83

important classes of natural antioxidants are phenolic compounds, such as: phenolic acids, flavonoids, stilbenes and lignans.

Alpinia zerumbet is a perennial plant native to the tropical region of East Asia, but it is also found in South America and Central America. It has several medicinal properties, and the oil extract is used as hypotensive, analgesic, antibacterial, and antifungal agents. In addition, the phenolic compounds contained in the leaves and rhizomes function as antioxidants, which can reduce the risk of developing cancer, cardiovascular diseases, among others.

The amount of total phenolics in the strain of A. zerumbet in Puerto Rico was determined by using the Folin-Ciocalteu reagent method. DPPH and ABTS free radical scavenging activity assays were performed to identify the antioxidant capacity of phenolic compounds. The total phenolic content and the antioxidant activity from the A. zerumbet strains in Puerto Rico and Japan were compared. Extractions with ethanol (1 hr), ethanol (24 hr), methanol, and acetone were performed. The Folin-Ciocalteu test data suggested that the most effective solvent to isolate the phenolic compounds is ethanol 24 hr, with the higher phenol concentration (26.93±0.35), compared to the other extractions performed.

The phenol concentration and antioxidant capacity of extracts were also determined, in terms of the percentage of free radical scavenging activity. The DPPH results showed a 66.0 % for the methanol extraction, while the ABTS test showed an 86.5 % for the ethanol 24 hr extraction. It is suggested repeating the DPPH test, since it is expected the ethanol 24 hr sample to have the higher antioxidant activity. Further statistical analysis should be performed to compare the data expressed as IC50.

Chemistry Presenter: Perez Ortiz, Giovanny E.

Mentor: Montes, Ingrid

Title: Synthesis and Characterization of Monosubstituted Ferrocenyl Chalcones Salts Derivatives

Authors: Giovanny E. Perez Ortiz (University of Puerto Rico Rio Piedras Campus), Sara M. Delgado Rivera (University of Puerto Rico, Rio Piedras Campus), Ricardo Gutierrez (Inter American University Of PR, Metropolitan Campus), Yaritza Rivera Torres (Inter American University Of PR, Metropolitan Campus), Ana R. Guadalupe Quinones, Phd (University of Puerto Rico, Rio Piedras Campus), David J. Sanabria Rios, Phd (Inter American University Of PR, Metropolitan Campus)

Abstract

Science and medicine have grown immensely over the years, creating new treatments for diseases and new techniques for better diagnosis'. With this being said, there has also been an increment in the immunity of many bacterial strains to the effects of different drugs at a worrying pace. The creation of 84

newer drugs, capable of eliminating harmful bacterial strains, is an ongoing battle that will always exist. Many studies have demonstrated that 90 % of drugs are given orally, which means that these new compounds must be soluble in an aqueous medium. Several of the treatments used for many diseases and infections are groups of drugs that work in tandem to achieve a better outcome. For this reason, it is important to contribute to the diversification and development of new compounds able to work together and be assimilated in the body for better medical outcomes. The incorporation of ferrocene in the structure of many compounds has shown to increase the biological activity potential. The salts that are derived from ferrocenyl chalcones are soluble in aqueous medium, which is why they are the suitable objects of study for our research. Our main interest focuses on the synthesis, characterization, and electrochemical studies of monosubstituted ferrocenyl chalcones salts derivatives and explore their anti-bacterial activity. This research specifically works with dimethyl amines and pyridines as substituents and then prepares the corresponding salts in moderate to good yields by a nucleophilic substitution in their corresponding nitrogen atom. Our goal is to improve the salts' bioavailability, solubility in water and their anti-bacterial activity. The synthetic methodology, characterization and preliminary biological assays of these compounds will be elaborated.

Chemistry Presenter: Quiñones Vélez, Gabriel E.

Mentor: Lopez-Mejias, Vilmali

Title: Design of Phosphonate-based Biocompatible Metal-Organic Frameworks (pBioMOFs) as a Drug Delivery System

Authors: Gabriel Quiñones Vélez (University of Puerto Rico, Rio Piedras)

Abstract

The design of metal-organic frameworks (MOFs) is gaining popularity in the field of chemistry due to the many practical applications that arise from their high porosity. Recently, several studies have suggested that MOFs can be employed to encapsulate pharmaceutically active ingredients for therapeutic purposes. The research attempts to design biocompatible MOFs capable of encapsulating active pharmaceutical ingredients (APIs), and employs these porous structures as a drug delivery system. To this end, it is proposed to use biocompatible phosphonic acids as the organic linkers, and biologically relevant metals will form a porous structure denominated as phosphonate-based biocompatible metal- organic frameworks (pBioMOFs). The selected phosphonic acids have been previously employed to treat bone related diseases. Furthermore, the calcium ion serves as a supplement that prevents bone loss and contributes to regeneration. Therefore, the resulting porous material could be potentially employed as a drug delivery system to treat bone related diseases (bone metastases, bone cancer, osteoporosis, etc.) if a sufficient quantity of API could be encapsulated and later released for oral treatment. Experimentally, the first pBioMOF has been developed using a green hydrothermal method under mild temperature 85

conditions. This pBioMOF is composed of phosphonomethyl iminodiacetic acid (PMIDA) as the organic linker, and calcium (II) as the metal ion. Characterization of the resulting white precipitate was performed using powder X-ray diffraction (PXRD), Raman spectroscopy and single crystal X-ray diffraction (SCXRD) analysis. Results demonstrate the formation of a crystalline structure composed by coordination bonds between the metal and the phosphonic acid, and unambiguously confirms that the synthetic route proposed for this pBioMOF was successful. Future work will encompass the exploration of the size requirements, available porous surface area to determine the capacity of these materials for drug delivery applications.

Chemistry Presenter: Ramos Sanfiorenzo, Barbara A.

Mentor: Ramos, Maiella

Title: Determination of cobalt, zinc and copper in water, sediment and Najas marina wetland plant in an aquatic ecosystem

Authors: Bárbara A. Ramos (Universidad de Puerto Rico Recinto de Arecibo), Alyssa Fernández (Universidad de Puerto Rico Recinto de Arecibo), Sonia M. Liciaga (Universidad de Puerto Rico Recinto de Arecibo), Natán J. Pérez (Universidad de Puerto Rico Recinto de Arecibo), Bárbara S. Ramos (Universidad de Puerto Rico Recinto de Arecibo)

Abstract

In this work we will address the content of cobalt (Co), copper (Cu) and zinc (Zn) by Najas marina (spiny water nymph) from the Caño Tiburones wetland. This hydrological system has been exposed to contamination by aqueous effluents produced from the Arecibo Regional Landfill, Barceloneta treatment sludge plant, agricultural activities, industrial activities, local or municipal sewage, among others. Sampling site selected in the Caño Tiburones was nearby the Arecibo Regional Landfill. Plant sediment and surface water samples were collected during an entire year per seasonal station. Levels of metals in studied samples were determined by means of an atomic absorption spectrometer with a flame atomizer. Spikes were also prepared to check for metal recovery. Surface water exhibited relatively low levels of Co, Cu and Zn. Trace element concentrations in sediment were in most cases higher than in plants as found in other studies (Mazej, et al, 2009). N. marina exhibited higher concentrations of Cu and Zn metals. Results may suggest that Najas marina could be used as a potential tool to study the trace metal pollution levels in the Caño Tiburones wetland.

Chemistry Presenter: Ramos Vicente, Andrea D.

Mentor: Ospina, Claudia

Title: Study and isolation of compounds of Croton discolor for cytotoxic and Antitumor activities

Authors: Andrea Del Mar Ramos Vicente (University of Puerto Rico Cayey), Pilar Paola De Jesús Gutiérrez (University of Puerto Rico Cayey)

Abstract

From past generations, our grand and greatgrandparents have been using plant leaves in different ways to treat colds, coughs, headache, and upset stomach among many others. Therefore, folk medicine has opens the doors for the study of a broad world of natural products for the treatment of diseases. Past studies on several specific kinds of native and endemic plants of Puerto Rico have shown to have growth inhibition activity against some breast adenocarcinoma cell lines. One of the most active plants against these cell lines was Croton discolor. Studies made by our laboratory group showed that the crude and solvent extracts (hexane, chloroform and ethyl acetate) of Croton discolor leaves have a synergistic and antagonistic effect in different mammary cancer cell lines. In other croton species, they have isolated two proaporphine alkaloid compounds, crotonosine and discolorine, which may be the principal components of their positive effects against cancer cell lines. Extracts made with chloroform have had the most growth inhibition results specifically with MCF-7 and T47D cell lines having 84% or more of inhibitory activity.1 At present, the plant was collected for a second time and solvent extracts of leaves and cortex have been made. Purification by column chromatography of the chloroform extract of the leaves is in process. The aim of this work is to isolate and identify the chemical compounds in leaves and cortex of Croton discolor responsible for the observed biological activity. In addition, evaluate the cytotoxic and antitumor activities of extracts and pure compounds of Croton discolor in different cell lines derived from solid tumors including ovarian (A2780, SKOV3), breast (MCF-7, MDA-MB-435), prostate (PC-3, LNCAP), and mammary epithelial cells (MCF-10A).

Chemistry Presenters: Rios Cruz, Isabel C Velez Vega, Paola J.

Mentor: Roman, Felix

Title: Synthesis of magnetite oleate with oxidation to the carbon double bond using potassium permanganate.

Authors: Isabel C. Rios Cruz (University of Puerto Rico-Mayaguez, Chemistry Department), Paola J. Velez Vega (University of Puerto Rico-Mayaguez, Chemistry Department), Victor Fernandez Alos (University of Puerto Rico-Mayaguez, Chemistry Department), Feliz R. Roman (University of Puerto Rico-Mayaguez, Chemistry Department), Tatiana Luna (University of Puerto Rico-Mayaguez, Chemistry Department), Oscar Perales (University of Puerto Rico-Mayaguez, Engineering Department)

Abstract

The compounds classified as endocrine destructors found in water systems such as hormones, personal and pharmaceutical products, antibiotics and polycyclic aromatic hydrocarbons, among others, are related to health effects in humans and aquatic life as well. Applying the nanoscale technology to plants (WWTP- Waste Water Treatment Plant) of current treatments, requires low cost applications and a high percentage of removal in the previously mentioned systems. The use of magnetite (Fe3O4) covered with surfactants as sodium oleate, facilitates the specific functionality to trap or attract specific compounds of interest and high risk to the endocrine system. To optimize this process of nanoparticles production, experimental parameters in the co-precipitation such as: temperature, stirring of the mixture, stoichiometric ratios and solvents, were used to design the particles at a nano level size. To determine the functional characteristics and size, the infrared and laser scatter light detector were used, respectively.

Chemistry Presenter: Ríos Santiago, Jessica N.

Mentor: Gonzalez, Karilys

Title: Synthesis of Transition Metal Complexes Based on Pyrene Derivatives

Authors: Jessica N. Ríos Santiago (University of Puerto Rico, Rio- Piedras Campus), Dr. Karilys González (University of Puerto Rico, Carolina Campus), Dr. Dalice Piñero (University of Puerto Rico, Rio- Piedras Campus) 88

Abstract

Nowadays scientists are working on the synthesis of new magnetic metal complexes for their application in memory devices. The area dedicated to the study of magnetic molecules as single domains is called Single Molecular Magnets (SMMs). SMMs are metalorganic complexes that could be magnetized by external magnetic fields keeping their magnetic behavior under a critical temperature. The incorporation of certain organic molecules can serve as linkers of metal complexes to provide the necessary magnetic interactions among them. So far, one of the problems faced within this line of research is the lack of structural control over the SMMs. We propose the modification of pyrene as suitable ligand to gain the expected structural control over the synthesis of SMMs. Pyrene is a polycyclic aromatic hydrocarbon with extraordinary electrochemical and photochemical properties. Due to pyrene's predictable interaction with neighboring aromatic rings and the charge-transfer properties gained from this, the synthesis of magnetic molecules is expected. Thus, the main goal of this project is to accomplish the synthesis of new series of ligands from polycyclic aromatics molecules to coordinate paramagnetic transition metal centers. Herein, we present the synthesis of 2,7-dicarboxylate pyrene ligand through the Birch reduction method follow by nucleophilic aromatic substitution. The characterization of the modified pyrene was performed by IR, H-NMR and GC-MS. Subsequently, reactions with paramagnetic metal centers will be undertaken with the new pyrene-based ligand.

Chemistry Presenter: Rivera, Glorimar

Mentor: Alamo Nole, Luis

Title: PHOTODEGRADATION OF METHYLENE BLUE USING Cd(S,Se) AND Cd(S,Te) QUANTUM DOTS SYNTHESIZED AT 180° C

Authors: Glorimar Rivera Rodríguez (Pontifical Catholic University of Puerto Rico, Ponce), Luis Alamo Nole (Pontifical Catholic University of Puerto Rico, Ponce)

Abstract

Some organic compounds such as dyes are hazardous to aquatic environments. Methylene Blue (MB) is an organic dye that has a diversity of applications in industries like biomedical, textile and paper manufacture. It can reach the environment due to an inappropriate handling by the industries. In the other hand, Quantum Dots (QDs) are nanomaterials with crystal sizes between 2 and 10 nanometers. They have the capacity to degrade some organic compounds through redox reactions. In this investigation, MB was photodegraded using QDs of Cd(S,Se) and Cd(S,Te) synthesized at 180° C. QDs have the ability to emit fluorescence and produce the formation of the electron/hole pair which can oxidize and reduce directly the contaminants and/or produce reactive oxygen species (ROS). These two mechanisms are responsible of the degradation of MB. The emission wavelength of Cd(S,Se) and Cd(S,Te) are 560 and 636 nm, respectively. The photo-degradation of MB was induced with an 89

ultraviolet lamp emitting radiation at 365 nm. The concentration of MB in the samples was analyzed by High Performance Liquid Chromatography (HPLC). The degradation of the MB depended on the concentration used of the QDs. The percentage of photodegradation of 10 uM solution of MB contacted with 100 mg/L of Cd(S,Se) and Cd(S,Te) were 99.0% and 44.3%, respectively. The results suggest that the photodegradation of MB with Cd(S,Se) is greater than Cd(S,Te) at 365 nm.

Chemistry Presenter: Rivera Cora, Milagros I.

Mentor: Rivera, Jose

Title: Development of Chalcones for Immunomodulating Systems

Authors: Milagros Rivera (UPR-RP), Maxier Acosta-santiago (UPR-RP), Jose M. Rivera-ortiz (UPR- RP)

Abstract

Immunomodulating particles have potential uses as immunotherapy, as adjuvant for vaccines and drug carriers yet these systems need to be improved. These particles are not cost effective for companies to use due to long and unreliable synthesis, low yields etc. We are currently working with colloidal particle we termed Supramolecular Hacky Sacks (SHS) which preliminary data shows immunomodulatory activity in vitro and in vivo. These are formed by thermo- and pH responsive Supramolecular Guanine Quadruplexes (SGQ), the self-assembly of 8-Aryl-2'deoxyguanosine (8ArdG) derivative subunits. These have shown to be very fitting to serve as a carrier for bio-relevant molecules as anti-cancer drugs, polysaccharides, DNA and proteins. Our goal is to make a library of 8ArdG derivatives to study the structure activity relationship (SAR) between the immunomodulatory activity and the addition of aromatic system in the C8 position. These aromatic chalcone systems tend to have fluorescence. This is an exceptional property for systems to have for it to be studied in cells and animals. In this study we will present the synthesis and characterization model compounds which we make via an aldol condensation reaction with a resulting library of fluorescent chalcones. These we study through the spectrophotometry and spectrofluorometry to evaluate the most promising derivatives that may have fluorescence in the cell. With those key experiments, we expect to have a developed as a fluorescent probe to add to the immunomodulator system for future cell work.

Chemistry Presenter: Rivera González, Osvaldo

Mentor: Primera-Pedrozo, Oliva M.

Title: Cellular Internalization of ligand-capped CdSe Quantum Dots

Authors: Osvaldo D. Rivera González (Universidad Metropolitana), Oliva M. Primera Pedrozo (Universidad Metropolitana)

Abstract

Cadmium selenide quantum dots (CdSe QDs) possess size-tunable optical properties that grant them the ability to serve as fluorescent probes for faster and more efficient bioimaging. Using specific capping ligands, such as glutathione-S (GSH), L-Cystine (L-Cys), mercaptopropionic acid (MPA), and thioglycolic acid (TGA) respectively, we were able to perform a direct-water synthesis of CdSe QDs, reducing toxicity, and avoiding the use of organic solvents. There have been many improvements done in our lab regarding nanoparticle design, stabilization, and biocompaibility. Recent published data has shown that our nanoparticles can potentialy withstand biological systems without the toxic effects that are usually due to cadmium ion liberation. Nevertheless, more experiments need to be performed to effectively characterize the quantum dots within the cellular system. The overall goal of this project was to determine the successful cellular internalization of capped CdSe QDs. To achieve this, cells were treated with varying aqueous solutions of CdSe QDs capped with four different biological ligands. Preliminary experiments began by simply exposing cells to stock solutions, and hence, different concentrations of purified quantum dots. Flow cytometry analysis showed minor shift in the fluorescent intensity of the cell population, suggesting cellular internalization. The experiments were later done exposing the cells to equal molar concentrations of the different QDs diluted in PBS buffer, to eliminate variability and make comparable sample sets. Cells treated with all four ligands show a minor population expressing increased fluorescent intensity at constant detector mV. TGA-capped CdSe-QDs appeared to show the highest relative increase in fluorescent intensity upon excitation at 462 nm. Each different capped nanocrystal expresses a specific excitation wavelength characterized via UV-Vis spectroscopy. At 462 nm, the laser wavelength is closest to the TGA characterized absorption wavelength, which stands at ~ 450 nm. This proximity explains why cells exposed to TGA-capped nanoparticles experienced the highest relative increase in fluorescent intensity. Nevertheless, all of the experimental groups experienced notable differences when compared to the control group. By performing these experiments, we are a few steps closer into adapting the use of CdSe QDs for molecular bioimaging purposes.

Chemistry Presenter: Rivera López, Gretchen M.

Mentor: Barletta, Gabriel

Title: Non-toxic and stable nano-carriers for delivering an antitumor agent in vivo

Authors: Gretchen M. Rivera López (Universidad de Puerto Rico en Humacao)

Abstract

In vivo targeted delivery of the growing number of promising novel short interfering RNA (siRNA)-based therapeutics is an important, but currently challenging, aspect of the drug development process for a variety of diseases, including cancer, viral infections, and autoimmune and neurodegenerative disorders. Our long-term goal is to develop evidence-based clinically-useful drug delivery systems to improve targeted therapies for human disease. Our objective is to develop optimized Super-Paramagnetic Nano Carriers (SPNCs) that can successfully deliver siRNAs to target tissues. Their efficiency will be evaluated using two in vivo models: Drosophila melanogaster and the mouse. The central hypothesis is that SPNCs designed with modified poly(ethylene imines) (PEI) will yield maximal delivery of siRNA molecules to targeted tissues in vivo.Different SPNC's were tested in CHO-K1 and HeLa cell lines for their transfection efficiency of firefly luciferase (GL2 + GL3) siRNA and we explored the benefits of magnetofection. Drosophila was successfully used to assess the SPNC's toxicity and their effects on the flies circadian rhythm. Reducing the polyctionic character of the nanoparticles eases their toxicity while maintaining their high transfection efficiency, which is actually increased by magnetofection. Toxicity results obtained with four additional cell lines highlight that cells tolerate these new nanoparticles differently. The circadian rhythm of Drosophila melanogaster was affected, and a dependence on the SPNC's surface groups was observed. There is a fine balance between the polycationic character of a carrier to its toxicity and transfection efficiency. Magnetofection is a powerful tool to deliver the carrier-siRNA complex to a target cell or tissue.

Chemistry Presenters: Rivera Ramirez, Cristina I. Garcia Gonzalez, Carlos M.

Mentor: Nicolau, Eduardo

Title: Synthesis and characterization of nanocellulose-based nanodiamond coatings for bone tissue engineering

Authors: Carlos García (UPR-Rio Piedras), Karlene Vega (UPR-Rio Piedras), Cristina Rivera (UPR- Rio Piedras)

Abstract

Diamond nanoparticles (DNP's) are physically hard and non-cytotoxic structures that can be easily modified and intermixed with other materials due to their easily modifiable surface sp and sp2 carbons. In order to expand the usability of DNP's herein we present the modification of this material with the novel cellulose nanocrystals (CNC's). The synthesis and characterization of these CNC's coupled covalently with DNP's were carried out in this project to explore its possible uses in bone tissue engineering. In brief, the CNC's were silylated with APTES at its 1° hydroxyl group to install a –NH2 group. Then, non-oxidized DNP's (nonoxDNP) were carboxylated at their surface moieties following a strong acid oxidation reaction to yield oxidized DNP's. This oxidation was evidenced by FTIR analysis. Thereafter, the CNC and oxDNP were coupled covalently through the well-known EDC/Sulfo-NHS reaction to form a peptide linkage between the two compounds. The resulting construct and its analogues were characterized through: Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), Raman spectroscopy and subject to an MTS cytotoxicity assay to study its compatibility with osteoblasts. The FTIR analysis provided evidence for the formation of the peptide bond, albeit not at 100% yield. TGA thermograms show that the addition of cellulose to the construct reduces thermal stability, but all constructs showed considerable stability until approximately 300°C. Furthermore, as shown in the MTS assay, CNC does not negatively affect osteoblast viability, but all DNP constructs lower it below 30%. Future works for this project include further characterization by: Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Lethal Dose 50% (LD50) assays and zeta potential analyses.

Chemistry Presenter: Robles Fontan, Monica M.

Mentor: López-Encarnación, Juan

Title: A Combined Experimental and Density Functional Theory Computations of Atomic Iron Supported by Organic Fibers

Authors: Mónica M. Robles Fontán (University of Puerto Rico at Cayey), Nelson Granda (University of Puerto Rico at Cayey), Julius Jellinek (Argonne National Laboratory), Wilfredo Otaño (University of Puerto Rico at Cayey), Juan M. López Encarnación (University of Puerto Rico at Cayey)

Abstract

The adsorption energetics and thermal stability of supported single metal atom reaction centers play a central role in the overall performance of these novel heterogeneous catalysts. The temperature effects, as well as those of the oxidation-state of the reaction center, may lead to the weakening of the center- support bonds and a consequent diffusion and agglomeration, and/or leaching, of the catalytic material and deterioration of the catalytic performance. Evidence for this has been observed in a variety of supports such as oxides (e.g., silica, alumina, and zeolites) and organic/organometallic polymers (e.g., porous organic polymers, covalent organic and metal-organic frameworks, and organic fibers).

This part of the project focuses on computational/experimental explorations of the coordination environment of metal-centers, i.e., single atom/ion centers on anchoring-groups of an organic fiber support. The computational study performed is based on the state-of-the-art density functional theory, molecular models of the organic polymer based fiber with and without the metal-center were designed and their atomic structure optimized. The adsorption energy of metal-center was explored for several adsorption sites at the fiber which is build from a polymeric matrix containing poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) as a building-blocks. In addition, we have simulated the infrared spectra of these models with/without the metal and make a direct comparison with the measured counterparts. The preliminary results give us an idea of the coordination environment of the metal and the most energetically favorable metal/fiber anchoring molecular structure.

Chemistry Presenter: Rodriguez Arbelo, Rafael E.

Mentor: Rivera, Jose

Title: Synthesis, self-assembly studies and Raman spectroscopy characterization of guanosine derivatives Raman tags

Authors: Rafael E. Rodriguez Arbelo (UPRRP), Luxene Belfeur (UPRRP)

Abstract

Our group has described the discovery and development of a family of colloidal particles we refer to as Supramolecular Hacky Sacks (SHS), which are suitable for the encapsulation and controlled delivery of drugs and genes to cells and whole organisms. These SHS particles are made from a sequential self- assembly of 8-aryl-2'-deoxyguanosine (8ArG) derivatives to supramolecular G-quadruplexes (SGQs), followed by a pH- and/or thermally-triggered assembly. It is essential to develop means to characterize these SHS in complex environments both in vitro and in vivo because of their promise for biomedical applications. We have recently started using Raman microspectroscopy to characterize these systems, and while in vitro characterization looks very promising, to enhance their detection in future studies with complex biological environments will likely require labeling these systems with "Raman tags" (alkynyl and deuterated methyl groups). We will present the results of the first synthetic efforts to make 8ArGs with "Raman tags, specifically propargyl and deuterated methyl groups, and also a characterization via NMR and Raman spectroscopies of the 8ArGs and preliminary self-assembly studies will also be presented.

Chemistry Presenter: Rodríguez Betancourt, Leonel E.

Mentor: Carballeira, Nestor

Title: Total Synthesis of 10-(4-methoxyphenyl)-6-decynoic Acid for Biomedical Applications

Authors: Rodríguez Betancourt, Leonel E. (University of Puerto Rico, Rio Piedras), Álvarez Benedicto, Ester (University of Puerto Rico, Rio Piedras), Morales Guzmán, Christian (University of Puerto Rico, Rio Piedras), Carballeira, Néstor M. (University of Puerto Rico, Rio Piedras) 95

Abstract

Natural acetylenic fatty acids have been isolated from a wide variety of plants, fungi cultures and marine invertebrates. These fatty acids are of particular interest to lipid chemists since many of these display important biological activities such as antitumor, antibacterial, antimicrobial, antifungal and HIV- inhibitory properties.1 Recent research has shown that the addition of phenyl groups into the structure of fatty acids enhances its topoisomerase inhibitory property by increasing the interaction of the fatty acid with the topoisomerase active site.2 Under this reasoning, we undertook the synthesis of the 10-(4- methoxyphenyl)-6-decynoic acid (1) to study how the addition of a p-methoxyphenyl group affects the fatty acid's inhibitory properties. The synthesis of 1 was performed in 4 steps and in a 33% overall yield. The total synthesis and preliminary bioassay results will be presented.

References:

(1) Dembitsky, V. Lipids 2006, 41, 883-924.

(2) D?yakonov, V.; Dzhemileva, L.; Makarov, A.; Mulukova, A.; Baev, D.; Khusnutdinova, E.; Tolstikova, T.; Dzhemilev, U. Bioorganic & Medicinal Chemistry Letters 2015, 25, 2405-2408.

Chemistry Presenter: Rodriguez Burgos, Dianelymar

Mentor: Pena, Guido

Title: Inhibición Bacteriana con Extractos de Alga Padina Gymnospora

Authors: Dianelymar Rodriguez Burgos (Universidad de Puerto Rico, Arecibo), Anumis Serrano Guitierez (Universidad de Puerto Rico, Arecibo), Jimary Colon Nuñez (Universidad de Puerto Rico, Arecibo), Victoria S. Rivera Diaz (Universidad de Puerto Rico, Arecibo), María G. Toledo Del Valle (Universidad de Puerto Rico, Arecibo)

Abstract

Desde el pasado, las algas marinas fueron utilizadas como alimento y por sus propiedades curativas como medicina. El propósito de esta investigación es comprobar si las Algas Marinas Padina Gymnospora inhiben el crecimiento bacteriano. Muestras de algas fueron recolectadas en las zonas de arrecifes de La Parguera en Lajas, Puerto Rico, debidamente preservadas y refrigeradas se trasladaron al laboratorio 236B de la UPR Arecibo. Después de lavar y moler las algas se procedió a la extracción con disolventes orgánicos en la proporción de 2:1 de cloroformo y metanol. Mediante roto evaporación, los disolventes orgánicos fueron separados de los extractos liposolubles de las algas. Los extractos liposolubles y los antibióticos comerciales Penicilina y Gentamicina, fueron inoculados en cultivos de bacterias, dos Gram (+): Bacillus cereus, Staphylococcus aureus y dos Gram (-): Escherichia coli y Enterobacter Aurogenes, para comparar su inhibición bacteriana. Los resultados mostraron que la 96

inhibición varía de acuerdo al tipo de bacteria. Al interpretar las dos graficas de la desviación estándar de la actividad inhibitoria de Enero- Mayo del 2010 y Agosto-Diciembre del 2010 se observó que en la bacteria E. Coli en los muestreos de Enero-Mayo tuvieron una mayor inhibición que en Agosto- Diciembre. Además, al realizar la desviación estándar de la actividad inhibitoria en las bacterias Staphylococcus aureus vs Enterobacter Aurogenes observamos que la alga Padina tuvo mayor inhibición de 5.20 mm en la bacteria E. Aurogenes mientras que en la S. Aureus fue de 4.85 mm. Además, que la Penicilina y la Gentamicina inhibieron en la S. Aureus valores de 1.65 mm y 3.87 mm mientras que en la B. cereus no inhibieron. Por los resultados obtenidos se puede concluir que los extractos liposolubles de las algas marinas inhiben el crecimiento bacteriano. Por otro lado, se ha observado que también existe un efecto estacional en la inhibición, que probablemente esté relacionado con el ciclo de reproducción de las algas marinas.

Chemistry Presenter: Rodríguez Narváez, Gabriel O.

Mentor: Diaz-Vazquez, Liz

Title: Catalytic Hydrothermal Liquefaction Of The Macroalgae Ulva Fasciata Using Iron Species From Different Sources.

Authors: Gabriel Rodríguez-narváez (University of Puerto Rico Rio Piedras), Arnulfo Rojas-perez (University of Puerto Rico Rio Piedras), Cecilia B. Frias-flores (University of Puerto Rico Rio Piedras), Héctor Pabón-colón (University of Puerto Rico Rio Piedras), María Adrover- castellano (University of Puerto Rico Rio Piedras), Liz M. Díaz-vázquez (University of Puerto Rico Rio Piedras)

Abstract

The depletion of fossil fuels has lead us to search for alternative sustainable and clean energy sources. Hydrothermal liquefaction (HTL) is the process used to convert biomass into biofuels using subcritical water as a reaction medium. This research focused on the HTL conversion of Ulva fasciata into biofuel using three different iron species: iron nanoparticles (FeNPs), red mud (RM), and magnetite sand (MagS). The main objective of this project was to determine which catalyst would produce the best quality and yield of biofuel. To achieve this, an aqueous Ulva Fasciata mix (15%) was submitted to the HTL process at 330°C, 300rpm and a reaction time of 15 min in presence of the mentioned catalysts. Once the system was cooled down the products were separated into three phases: solid, liquid and gaseous. Characterization analyses were performed by using Thermal Gravimetrical Analysis (TGA), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES), Gas Chromatography Mass Spectrometry (GCMS) and Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR). The bio- oil produced for each HTL run was 22.31 ± 2.97%wt. without the catalyst, 21.75 ± 2.75%wt. for RM, 20.30 ± 0.38%wt. for FeNPs and 20.10 ± 1.26%wt. for MagS. To determine the quality of the oil their 97

constituents were studied. The GC-MS analysis shed light into the amount of nitrogenized, sulfonated and other energy relevant compounds present in the bio-oil that were used as the criteria to determine its quality.

Chemistry Presenter: Rodríguez Rivera, Elys P.

Mentor: Ospina, Claudia

Title: Biological Screening of Moringa oleifera for cytotocixity and antitumor activities

Authors: Elys Paola Rodríguez Rivera (University of Puerto Rico ay Cayey)

Abstract

Moringa oleifera, also known as the miracle tree, has a vast reputation regarding folk medicine. It is known to relieve symptoms of arthritis, cancer, cardiovascular problems, asthma and others. In the present study, the leaves and cortex were chemically scrutinized in the search of biologically active compounds. The plant was subjected to maceration, liquid-liquid extraction and column chromatography. The leaves crude was evaluated against prostate, breast and ovarian cancer cell lines, exhibiting LC50 values of 0.17 ?g/mL, 0.25 ?g/mL and 0.27 ?g/mL respectively. The M. oleifera hexane leaves extract yield 13 fractions, in which one is currently being analyzed and further purified.

Chemistry Presenter: Rodriguez Torres, Yamil M.

Mentor: Pares-Matos, Elsie I.

Title: Isolation, Purification and Characterization of VEGF-A??? for Aptamer Complex Studies

Authors: Yamil M. Rodriguez Torres (University of Puerto Rico-Mayaguez), Dr. Elsie I. Pares Matos (University of Puerto Rico-Mayaguez)

Abstract

VEGF and its five isoforms are proteins responsible for events such as cell migration,endothelial cell proliferation and inhibition of apoptosis, among others. All known VEGF isoforms come from a single VEGF gene, spliced in different ways and present significant structural differences, such as in molecular 98

weight. Among its isoforms VEGF121, VEGF145 and VEGF165 have been the ones reported to induce endothelial cell proliferation and in vivo angiogenesis, the formation of new blood vessels, with the 165 form predominating among these. Unregulated angiogenesis has been linked to diseases such as rheumatoid arthritis and retinopathy and cancer. With regards to the latter, unregulated VEGF expression can be observed in the development of tumors, as new blood vessels are essential for the delivery of nutrients necessary for solid tumoral growth. As such the isolation, purification and biophysical characterization of this protein is central to its study. We utilize a GST-VEGF recombinant fusion protein, expressed by a KRX strain of E. coli bacterium. So far the protein has been able to be successfully expressed and isolated, but successful purification of said protein has not been achieved by means of an affinity column chromatography.

Chemistry Presenter: Rodriguez Valdes, Yanira

Mentor: Rivera, Jose

Title: Synthesis of boronic esters for the development of Hydrogen Peroxide-Responsive Supramolecular G-quadruplexes

Authors: Yanira Rodríguez (University of Puerto Rico, Rio Piedras Campus), Luis A. Prieto Costas (University of Puerto Rico, Rio Piedras Campus), Adlin V. García (University of Puerto Rico, Rio Piedras Campus), José M. Rivera (University of Puerto Rico, Rio Piedras Campus)

Abstract

Hydrogen peroxide (H2O2) and other reactive oxygen species (ROS) are generated regularly as products of normal oxidative metabolism, and act as essential signaling molecules in many biological processes. However, an imbalance in ROS regulation has been linked to aging and other diseases such as chronic inflammation, diabetes, Alzheimer's and cancer. Probes for H2O2 have been previously developed and studied, but it remains a challenge to develop systems that serve as both probes and drug delivery systems. Our group has developed pH- and thermo-responsive supramolecular G-quadruplexes (SQGs) whose properties are modulated by specific modifications in the constituent 8-aryl-2'-deoxyguanosine (8ArG) derivatives. Aryl boronate esters (BE) have been reported to oxidize to phenols in the presence of H2O2 with a frequent concomitant change in fluorescence. Thus, we hypothesize that the addition of a BE group to 8ArG will enable H2O2-responsive SGQs, which can have a change in fluorescence and this reaction/responsiveness of the boronic ester-containing guanosine derivative (BEG) with H2O2 would be trackable, as reported in previous studies in the field. We will present the initial studies to test our hypothesis. Specifically, to evaluate the feasibility of our strategy, we designed and synthesized a series of model pinacol BE compounds via aldol condensation of acetophenone and various BE aldehydes. The preliminary studies we will show indicate that a change in fluorescence is, in fact, observed when H2O2 99

is added to a solution of a model BE compound. For the next steps in the development of the H2O2- responsive SGQs we will choose the most suitable boronic ester aldehyde(s) for the system and use it/them to synthesize BEGs. We expect that the resulting SGQs will enable the construction of particle delivery systems that release a therapeutic agent selectively upon activation by hydrogen-peroxide.

Chemistry Presenter: Rodríguez Vélez, Astrid C.

Mentor: Pares-Matos, Elsie I.

Title: Determination of FAP1 RNA levels in Saccharomyces cerevisiae cultured in nitrogen- deficient media

Authors: Astrid Rodríguez-vélez (University of Puerto Rico at Mayaguez), Elsie Parés-matos (University of Puerto Rico at Mayaguez)

Abstract

The protein FAP1 was found in the cytoplasm of Saccharomyces cerevisiae, and it confers resistance to the immunosuppressive drug and antifungal Rapamycin, by competing with the drug for the binding site, which is mutually exclusive for both, thus preventing the formation of the Fpr1p-Rapamycin complex. This complex inhibits the products of the TORC1 which regulates essential pathways that control some cytoplasmic and nuclear events, and some nutrient regulated genes. In preliminary studies, it has been observed that FAP1 needs to be over expressed in other to confer this resistance to the yeast. The complex FAP1-Fpr1p has been also observed in the absent of Rapamycin, especially when some nutrient levels are low. By using these observations, we propose here that the concentration of FAP1 might be inversely proportional to the availability of nutrients in culturing media. To prove this hypothesis, the strain CFY7-PJ69-6A of Saccharomyces cerevisiae will be cultured in nitrogen-limited media and at different time periods. The technique RT-qPCR will be used to quantify the amount of FAP1 RNA available at different concentrations of ammonium sulfate (the nitrogen source), and at incubation points of 3 h, 6 h, 12 h and 24 h. The expression levels observed with the RT-qPCR could be useful to optimize bioprocesses at industry by monitoring FAP1 in order to determine the availability of target nutrients in media in yeast cultures.

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Chemistry Presenter: Roman, Kharina

Mentor: Santos-Santori, Lizette

Title: Quantification and identification of sulforaphane from different types of Brassica oleracea var. botrytis by HPLC

Authors: Kharina M. Román Rivera (Pontifical Catholic University of Puerto Rico), Lizette Santos Santori (Pontifical Catholic University of Puerto Rico)

Abstract

The isothiocyanate sulforaphane is a compound that is found in a wide variety of cruciferous of the gender of Brassicaceae, including cauliflower. This substance has anticancer and antimicrobial properties. The objective of this research is to quantify and identify what type of cauliflower contained more sulforaphane in the inflorescence, because this vegetable is present in cauliflower of different colors (green, purple, white, and yellow). To perform the quantification of sulforaphane the conversion of glucoraphanin to sulforaphane is required. Procedure to obtained the sulforaphane include the elimination of moisture through drying the cauliflower in an oven, extraction with dichloromethane, purification of the extract in columns of solid phase extraction, and detection by HPLC-UV. For the identification of sulforaphane, the retention times were measured. Standards and samples were compared. A calibration curve was generated using five concentrations of standard sulforaphane with a range of 0 to 75 ?g/ml to quantify each sample of the different types of cauliflowers. Once the process was completed, the results show that the white cauliflower contains more amount of the substance with an area of 61,897.02 mAU*s. In comparison with the yellow cauliflower that show an area of 29,444.10 mAU*s. Therefore, the white cauliflower contains more sulforaphane and will have greater anti-carcinogenic activity. These results can be used to create a new method to fight and prevent the appearance of cancer cells.

Chemistry Presenter: Roque Gonzalez, Shamarie

Mentor: Goenaga-Jimenez, Miguel

Title: Synthesized Nanostructures Photocells

Authors: Shamarie Roque Gonzalez (Turabo University), Abrahan Garcia Cintron (Turabo Univeesity) 101

Abstract

The need for alternative energy sources have recently become a priority. The growing demand for energy, the alarming increase in greenhouse gas emissions and the variability of fossil fuel prices have driven the need for clean energy. In this situation we find the source of a great ally, solar UV is about to achieve the price-per-watt needed to become a competitive source. The discovery of the photo-voltaic effect and solar cells to convert sunlight into electricity, is attributed to French physicist Edmond Becquerel in 1839. After discovering the use of different applications of solar cells to improve the efficiency of generation current, and flexible solar panels or other. For this reason we want to achieve forge a solar cell that is effective and in turn easy to apply to any surface, this with the purpose of generating power by a photo catalytic synthesis working next to a viscous product culminating as "energetic painting" .What main in this research has been the synthesis nano-structure silicon surface, which is capable of great reduction in reflectance, being a cheap and scalable method. Silicon is the best options to generate electron hole, which will produce energy to be transported by the anode and the cathode, with a difference of electric potential between the two electrolytes. To interaction dissolved cations moving towards the cathode, we are using silver nano-wires, for their different magnetic and electrical properties. As for the anions toward the anode, we will use copper nano-wires for ease of synthesis, low cost and effective transfer of electrons. For this purpose, the silicon nano-wires have been synthesize hyper branched mono-crystalline using wafer holder and the etching method. The synthesize product will be characterized with various techniques to know their morphology, diameters and lengths. These techniques are SEM, BET and XRD. The last three synthesis to build the new solar cell performance in terms of cost and simplicity thoughts about this process to be the most promising for our task realized.

Chemistry Presenter: Rosa Vega, Jurynelliz

Mentor: De Jesus, Walleska

Title: Enzymatic and Bacterial Activity of Fungal strains isolated from Alpinia zerumbet

Authors: Jurynelliz Rosa Vega (UPR-AGUADILLA), David Pacheco (UPR-AGUADILLA), Gloria Orta (UPR-AGUADILLA), Carlos Robert (UPR-AGUADILLA)

Abstract

The endophytes of medicinal plants are being studied in recent years for its potential as sources of bioactive products. The host and endophytes can have a variety of symbiotic relationships: antagonist or opportunistic pathogen. A. zerumbet has been used as a medicinal plant for the treatment of influenza and pain. It contains several bioactive compounds and has shown pharmacological properties such as antihypertensive, cardiovascular protective effects and antioxidant effects. The objectives of this study are to isolate and identify the endophytes from the leaves and flowers from A. zerumbet, study the 102

interaction of these fungi with bacteria, and identify the presence or absence of specific enzymes in fungi. Six fungi have been isolated from the leaves and flowers of the plant. Strains are being identified by traditional morphological methods. One of the identified fungi is the species Pestalotia macrotricha. The antagonic interaction of fungal isolation are going to be assessed with the bacteria's S. epidermis, E. faecalis, A. faecalis, E. coli, E. aerogenes, M. roseus, and P. mirabilis. Solid medium was used to identify the presence or absence of extracellular enzymes such as amylase, lipase, cellulase, protease, and laccase. The experiments showed that 36% of the fungal strains have amylolytic activity, 54% have laccase activity, 54% have proteolytic activity, 27% have lipolitic activity and 36% have cellulose activity. It is the first time that studies of the endophytes of A. zerumbet are conducted. These results are important for future clinical microbiological studies, and to understand the dynamic interactions of fungal endophytes to produce specific enzymes as defense mechanisms.

Chemistry Presenters: Rosado Rosa, Joenisse M. Ramos Freyre, Ricardo J.

Mentor: Guzmán Blas, Rolando

Title: Preparation of magnetic nanoparticles of ZnxCo1-xFe2O4 for applications in biomedicine

Authors: Joenisse M. Rosado Rosa (Universidad del Sagrado Corazón), Paloma C. Opio Ramírez (Universidad del Sagrado Corazón), Ricardo J. Ramos Freyre (Universidad del Sagrado Corazón)

Abstract

Magnetic nanoparticles have been proposed for use in biomedical purposes to a large extent for several years. In recent years, nanotechnology has developed to a stage that makes it possible to produce, characterize and speci?cally tailor the functional properties of nanoparticles for clinical applications. This has led to various opportunities such as improving the quality of magnetic resonance imaging, hyperthermic treatment of malignant cells, site-speci?c drug delivery and the manipulation of cell membranes. To this end, we will prepare a variety of ZnxCo1-xFe2O4 nanoparticles, using the method of precipitation. In our case, the magnetic material will be prepared for use in hyperthermic treatment of malignant cells and site-speci?c drug delivery. We will hope to get particles with a ranging size of 5 to 20nm.

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Chemistry Presenter: Rullan Varela, Valeria

Mentor: Rivera Portalat, Nilka M.

Title: Evaluation of the bioactivity, antioxidant and anticancer properties of Cnidoscolus chayamansa

Authors: Valeria Rullan Varela (UPR- Mayagüez)

Abstract

Oxidative damage in the DNA is a cause of abnormal cell division leading to cancer. This is due to the presence of free radicals that inhibit biological mechanisms and promote the peroxidation of lipids. It is a common idea that natural products, such as plants, are important sources of anti-cancer (lead or hit) molecules. This research is focuses on the different extracts of the plant Cnidoscolus chayamansa (also known as Chaya). The bioactivity of the plant extracts using the brine shrimp lethality test was determined. Also, the Total Phenolic Content using the Folin-Ciocalteu reagent, and the determination of its antioxidant properties using the di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) assay will be reported. The extracts were also used to determine their anticancer activity against the colon cancer cell line (HT-29) using the MTT assay to measure the cytotoxic effects. A strong correlation between the lethality rate of brine shrimps in the presence of natural products and the cytotoxicity against different cancer cell lines has been found. The anticancer activity of plants has also been strongly correlated with their phenolic content and antioxidant properties. An analysis of the correlation between total phenolic content and antioxidant activity, as well as the cytotoxic effect of the fractions isolated towards the shrimps and the cell line will be presented.

Chemistry Presenter: Santiago, Ismarie

Mentor: Hernandez Castillo, Ramon

Title: Synthesis of trans-[Pd(2-amino-5-methylthiazole)2Cl2]: Optimization of Crystallization Conditions

Authors: Ismarie Santiago Rivera (Pontifical Catholic University), Ramón Hernández Castillo (Pontifical Catholic University) 104

Abstract

Cisplatin, cis-diamminedichloroplatinum(II), was the first inorganic compound to show antitumoral properties. Various unrelated Pt(II) compounds are active in a wide variety of cancer types and can overcome resistance mechanisms. The complex [Pt(NH3)(2-methylpyridine)Cl2], ZD0473, is a well- known example of these new platinum drugs. In early stages of metal-based anticancer drug development, metals other than platinum were somewhat discarded based on reactivity profiles. Anyhow, an appropriate selection of ligands has produced complexes with activities close to that exerted by cisplatin. With detoxification via cellular thiols in mind and potential tuning of substitution reactions at the metal center via incorporation of functional groups, new palladium complexes have been synthesized and their structures solved by single crystal X-ray diffraction. This study is focused on the synthesis and crystallization of the complex trans-Pd(2-amino-5-methylthiazole)2Cl2]. Although the synthesis of this complex as a good yield and the IR and NMR spectra point to the synthesis of the desired product, elemental analysis determinations differ slightly from the calculated values. The crystallization of this complex is intended for purification as well as structural characterization, if appropriate crystals are obtained. Optimization of crystallization conditions has rendered crystalline particles with somewhat defined edges similar to those obtained previously which has been used for X- ray diffraction. Any structural information obtained could have tremendous implications in the biological activity of these new complexes.

Chemistry Presenter: Santiago Maldonado, Xaimara

Mentor: Montes, Ingrid

Title: Synthesis and Characterization of Curcumin Analogías

Authors: Xaimara Santiago Maldonado (University of Puerto Rico, Rio Piedras Campus), Josué Rivera Hernández (University of Puerto Rico, Rio Piedras Campus), Myrna Otaño Vega, M.s. (University of Puerto Rico, Rio Piedras Campus), Ingrid Montes González, Ph.d. (University of Puerto Rico, Rio Piedras Campus)

Abstract

Present in the indian spice Curcuma longa, commonly known as tumeric, curcumin is a natural chalcone with wide range of biomedical applications. Within them we find: antioxidant, chemopreventive, chemotherapeutic, cardiovascular and pulmonary diseases, diabetes, depression, among others. Recent studies even explore the possibility of using curcumin and its derivatives as potential drugs for the treatment of Alzheimer's disease and malaria. Unfortunately, the bioavailability of the compound is restricted because of its poor absorption, limited tissue distribution, rapid metabolism, and short half- life. This research is centered in the synthesis of curcumin analogues encompassing the ferrocene moiety. Literature reported shows that the incorporation of this ferrocenyl moiety to produce analogues 105

of well-known drugs, improves the bioavailability and bioactivity of them. Our specific aim is to synthesize and characterize curcumin analogues from acetylferrocene. Moreover, this research also aims to study some modifications of the substituents as well as their positions in the phenyl group. Eventually, the main goal is to determine possible biomedical applications of this analogues and how the variation in substituents affect these activities. The methodology for the synthesis, characterization and preliminary bioassay results will be elaborated. This research is sponsored by RISE program, with a NIH funding grant number 5R25GM061151-14.

Chemistry Presenter: Santiago-Martoral, Liz N.

Mentor: Nicolau, Eduardo

Title: Preparation and Characterization of Metalized Nanocellulose Composites as Precursors for Forward Osmosis Membranes

Authors: Liz N. Santiago Martoral (UPR-RP), Valerie O. Morán (UPR-RP), Melivette Feliciano (UPR- P), Perla Cruz (UPR-RP), Michael Flynn (N.A.S.A.), Eduardo Nicolau (UPR-RP)

Abstract

Cellulose nanocrystals (CNC) are a revolutionary bionanopolymer that offers promising mechanical and chemical properties to further advance the field of nanotechnology. In this work, we are exploring the feasibility of synthesizing CNC-based composites which are resistant to microbial growth for the development of Forward Osmosis (FO) membranes that can be later employed for water purification purposes. CNC were chemically modified, through a silylation reaction of the exposed CNC-hydroxyl groups using 3-Aminopropyl)triethoxysilane (APTES). These constructs were then modified with Silver (Ag) and Platinum (Pt) nanoparticles to obtain composites with antimicrobial and electrochemical active properties. All CNC-based composites were characterized and analytically compared by Thermo Gravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD). Membrane supports were tested in a forward osmosis system to test their efficiency and establish initial parameters for further comparison. Our data suggest that the expected CNC-based composites were successfully obtained. Currently, the work is directed towards the development of the membrane via phase inversion process and their testing in a Forward Osmosis system.

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Chemistry Presenter: Santos, Christian

Mentor: Cabrera, Carlos

Title: Electrodeposition of Pd and on highly conductive Vulcan XC-72R for direct ethanol electrooxidation.

Authors: Carlos Cabrera, Carlos Velez, Christian Santos Homs

Abstract

The electrodeposition of Pd nanoparticles on highly conductive Vulcan XC-72R was accomplished via the rotating disk slurry electrodeposition technique (RoDSE). Cyclic voltammetry (CV) and chronoamperometry demonstrate that the Pd/Vulcan catalyst possesses enhanced activity and stability towards the electrooxidation of ethanol in alkaline media in the different synthetized of Pd/Vulcan XC- 72R. The synthesized was making with different revolution of the rotating disk. The different rotating was (400, 800, 1200, 1600, 2000) rpm. Additionally, to further understand the synthesized Pd/Vulcan catalyst physical characterization was done to the same. A typical Pd diffraction pattern is appreciated by X-ray diffraction (XRD).

Chemistry Presenter: Serrano Vazquez, Yamice M.

Mentor: De Jesús-Echevarría, Maritza

Title: Chronic Obstructive Pulmonary Disease (COPD) correlation with Total Suspended Particles (TSP) in Mayagüez City Environmental Health Impact

Authors: Serrano Vázquez, Yamice M. (UPR-Mayagüez), De Jesús Echevarría Maritza* (UPR- Mayaguez)

Abstract

Air pollution has persistently grown as an environmental health issue, mostly in urban and metropolitan areas. Atmospheric activities, anthropogenic sources and many other extracurricular events contribute to the deterioration of air quality. A research study of the environmental and health impact in the municipality of Mayagüez was completed to quantify total suspended particles – particulate matter 10?g (TSP/PM10) during the wet seasons of 2013 and 2014. Results were correlated with the amount of hospitalizations provided by the ASES (Administración de Seguro de Salud de Puerto Rico) due to chronic obstructive pulmonary diseases (COPD) during the seasons. A high volume air sampler (HVAS) system 107

was used to collect air samples daily from August to November 2013 and 2014 to determine the average TSP using the gravimetric method. The annual average TSP values for the wet seasons of 2013 and 2014 were 25.50 µg/m3 and 29.64 µg/m3, correspondingly. The highest monthly TSP value in 2013 was in August, 29.89 µg/m3 and in October 2014, 36.14 µg/m3. The highest daily value for 2013 was 67.22 µg/m3 on September 9. and 109.45 µg/m3 on October 3, 2014. The highest number of hospitalizations occurred during these precise months ranging from 423-494 in 2013 and 989-1032 in 2014 in Mayagüez. The results show a preliminary correlation of the TSP value with the hospitalizations for Chronic Obstructive Pulmonary Disease (COPD). None of the values obtained exceeded the limits stipulated by the National Ambient Air Quality Standard (NAAQS) but awareness must be taken to prevent further environmental and health complications.

Chemistry Presenter: Soto Pérez, Joesene J.

Mentor: Cabrera, Carlos

Title: Study of the urease enzyme at different pH for the detection of Urea

Authors: Joesene Soto Pérez (University of Puerto Rico, Río Piedras), Myreisa Morales Cruz (University of Puerto Rico, Río Piedras), Carlos R. Cabrera (University of Puerto Rico, Río Piedras)

Abstract

Urea is a small-uncharged molecule that represents an important role on the metabolism of nitrogen in urine. Modern clinical laboratories use spectroscopic methods to detect it, but they are time consuming and widely dependable on the sample preparation. Here, we propose a study to monitor the quantity of urea in urine that is secreted by the kidneys, because is know that high amount of urea concentration can led to a wide variety of conditions including renal failure. We monitored urea using the urease enzyme, which catalyzes the hydrolysis of urea to produce ammonia and carbonic acid. Urea is electrochemical inactive, therefore, we concentrate our experiment on the oxidation of ammonia using a platinum electrode. We used cyclic voltammetry technique to monitor the oxidation peaks of ammonia in a conventional electrochemical cell. The pH was evaluated to get the best response of oxidation considering the activity of the enzyme in a synthetic urine solution and the ammonia available. Results indicate that pH 8 has the better oxidation current with 0.001 mA/cm2, although is under the ammonia pKa. In conclusion the activity of the enzyme limits the oxidation current more than the available ammonia to oxidize. This research represents an encouraging attempt to develop a biosensor for the detection of urea in real urine samples.

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Chemistry Presenter: Strubbe-Rivera, Jasiel O.

Mentor: Rodriguez-Quiñones, Jose

Title: Effect of Copper Imbalance in Cell Viability in the Budding Yeast Saccharomyces cerevisiae

Authors: Jasiel O. Strubbe-rivera (Pontifical Catholic University of Puerto Rico), Yaritza I. Vélez- burgos (Pontifical Catholic University of Puerto Rico), José F. Rodríguez-quiñones (Pontifical Catholic University of Puerto Rico)

Abstract

Copper transport inside the cells is important since this transition metal catalyzes many reactions required for proper cellular functions. This mechanism in Saccharomyces cerevisiae is controlled by the copper transport protein (Ctr1p), a membrane protein that regulates this high affinity copper transport machinery by assisting and bringing copper to the intracellular compartment. In addition, other three major proteins (Cox17p, Atx1p, and Ccs1p) serve as chaperones routing this metal to specific organelles. In order to elucidate the copper transfer mechanism in yeast, wild type (wt), ctr1? and atx1? mutant cells were grown under low and rich copper conditions. These conditions were achieved by treating cells with the chelating agent bathocuproinedisulfonate (BCS) and copper (II) sulfate (CuSO4), respectively. Cell growth sensitivity assays revealed that both ctr1? and wt cells grew normal under copper deficient conditions. However, atx1? cells, which lack targeting of copper to the secretory compartment, grew significantly faster at higher copper-deficient conditions. This data suggest that copper deprivation on atx1? cells activates the high affinity copper transport machinery, increasing the copper uptake, hence the cell growth increase in these mutant cells. On the other hand, our results showed that CuSO4 strongly affected the growth in wt and ctr1? cells. However, this decrease in growth was strongly observed in wt compared ctr1? mutant cells. These results suggest that since copper is not being effectively recruited in ctr1? mutant cells, deletion of the CTR1 gene provide higher resistance in rich copper conditions. Elucidation of the copper transport machinery in Saccharomyces cerevisiae will allow us to identify target genes involved in the response to copper imbalance associated with health conditions in humans. This research is supported by an Institutional Development Award (IDeA) from the NIGMS of the NIH (P20 GM103475) and the PRLSAMP program from the (NSF) (GRANT NUMBER).

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Chemistry Presenter: Torres Garcia, Xiomaries

Mentor: López-Encarnación, Juan

Title: Comparative Energetics of Reaction Steps Involved in Alkane Metathesis on a Porous Organic Polymer vs Silica Supported Ta-Complex Catalyst: A Computational Study

Authors: Xiomaries Torres Garcia (Department of Chemistry, University of Puerto Rico at Cayey), Jullius Jellinek (Chemical Sciences and Engineering Division, Argonne National Laboratory), Juan M. López Encarnación (Department of Mathematics-Physics, University of Puerto Rico at Cayey)

Abstract

Our society is currently confronting problems related to energy conversion; therefore the application of different important reactions in the industrial environment may afford solutions to these difficulties. Currently, hydrocarbons are the primary energy sources; becoming compounds of high interest in the chemical industries. The efficient and economically feasibility conversion of alkanes and alkenes would greatly enhance global prosperity for transportation and energy consumption fuels. However, the transformation of these hydrocarbons is a challenge, because the stability and inertness of carbon- hydrogen and carbon-carbon bonds. Alkane/Alkene metathesis is a catalytic reaction that transforms molecules of a given alkane/alkene into its homologues (higher and lower), representing a powerful tool for the petrochemical industries.

Here, we are focus on the fundamental mechanistic aspects of alkane/alkene metathesis reaction by computationally design and test a biomimetic inspired catalyst. Our goal is to explorer the support effect on the energy barriers involved in the carbon-carbon bond formation of alkane metathesis[1]. As a model, we have investigated the reaction of ethene, an alkene, with a tantalum-complex embedded into a catechol porous organic polymer [2] catalyst [POP(Ta(=CH2)H] vs silica supported tantalum-complex. We are comparing the porous organic polymers (POPs) with silica as catalysts-support because the POPs material brings the best feature of homogenous and heterogeneous catalysis and they are gaining interest as potential and important new catalytic support in the catalysis community.

[1] J. Am. Chem. Soc. 2008, 130, 7984-7987

[2] Chem. Mat. 2012, 24, 1292-1296

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Chemistry Presenter: Torres Olivencia, Nolishka L.

Mentor: De Jesus-Echevarria, Maritza

Title: Biopesticide Compounds in the Fresh and Dried Leaves of Momordica charantia L. by HS-SPME and GC/MS

Authors: Torres Olivencia, Nolishka (UPR-Mayagüez), Jesús Echevarría, Maritza* (UPR-Mayaguez)

Abstract

Various studies on natural plant products against insects indicate them as possible alternatives to synthetic chemical insecticides. Leaf extracts have demonstrated broad-spectrum antimicrobial activity. The composition of volatile emitted by the fresh and dried leaves and the smoke of the Momordica charantia L. was analyzed by headspace solid phase micro extraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC/MS). Major different were found in the fresh leaves and the smoke. The most abundance compound in the fresh leaves, with water and combining water and heat was 2-hexenal and it is classified as pesticide. Several toxic compounds were found in the fresh and dried smoke, like toluene, styrene, limonene, benzaldehyde among others. Insecticidal compounds identified were 2-hexanal, benzaldehyde, beta ionone, 1-hexanol, and beta cyclocitral in the fresh leaves and toluene, limonene, and benzaldehyde in the smoke. The feeding bioassay response test using ants with chopped fresh leaves was successful.

Chemistry Presenter: Torres Rodriguez, Kyabeth M.

Mentor: Oyola, Rolando

Title: In Vitro Study of the Interaction Between Gold and Gallium Nanoparticles with Human Serum Albumin

Authors: Kyabeth M. Torres Rodriguez (University of Puerto Rico, Humacao), Rolando Oyola Martinez (University of Puerto Rico, Humacao)

Abstract

Nanotechnology has a great impact in areas such as chemistry, physics, biology, and medicine, among others. More specifically, the effect of nanoparticles in human health is of great interest. When nanoparticles are in contact with human serum they binds to proteins forming what is known as a corona. In this work we study the effect of gold and gallium nanoparticles interaction with human serum 111

albumin in vitro. Specifically, the HSA thermal stability was measured in the presence of those nanoparticles using FTIR probing the secondary structure. The results show the emergence of an absorption band at 1620 and a shoulder at 1680 cm-1, characteristics of aggregated beta structures at temperatures higher than 75 ° C. In addition, the presence of gold nanoparticles does not change the HSA thermal stability under our experimental conditions.

Chemistry Presenter: Valles Rivera, Joelyann

Mentor: Rodriguez Lopez, Margarita

Title: An electrochemical study of thin film gold electrode surface composition and structure by cyclic voltammetry.

Authors: Joelyann Valles Rivera (Pontifical Catholic University of Puerto Rico), Lizmarie Camacho Velazquez (Pontifical Catholic University of Puerto Rico), Margarita Rodriguez Lopez (Pontifical Catholic University of Puerto Rico)

Abstract

Cyclic Voltammetry is an electroanalytical technique that correlates the current at the working electrode versus the applied potential to give the cyclic voltammogram (CV) signal. CV serves as a fingerprint of the electrode surface. The analysis of the CV obtained at precise values of sweep rate, electrode pretreatment, concentration and nature of the electrolyte leads to an affluence of information of the electrode surface composition and structure. In this presentation it is shown an electrochemical study of thin films gold electrodes prepared by recycling fragments of recovered thin-layer gold supported on glass from various sources. Electrode pretreatment procedures were performed to alter the microstructure of the electrode in order to achieve a reproducible surface. The formation of an oxide layer and its subsequent reduction and the electrochemical double layer region under defined experimental conditions are used as reference for checking in situ gold electrode surfaces status. The surface pretreatment produces reproducible blank signals of gold electrodes in sulfuric acid solutions. CV can be used to both check the surface state at the metal solution interface and also to find out correlations between surface structure and applied potential.

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Chemistry Presenter: Vargas Vazquez, Juan A.

Mentor: Rivera, Harry

Title: Automatic Fuel Cell Catalyst Ink Applier

Authors: Juan A. Vargas Vazquez (Universidad Interamericana Recinto Bayamon)

Abstract

Fuel cells are being studied as an alternative to energy sources we use today. Its main component, the membrane-electrode assembly (MEA) is responsible for making the fuel and the oxidant supplied to the cell to convert chemical energy directly into electrical energy. Furthermore, the byproduct of the reaction is pure water; a feature that makes this technology very attractive. Actually, the most widely fuel used is hydrogen, but other fuels, like ammonia, are being studying for electrical energy generation and waste water remediation. Reproducibility is a major obstacle in the preparation of MEA's. Currently, the catalyst is applied manually to the membrane of the Fuel Cells. Thus, it increases the risk of disproportion errors due to an uneven layer of catalytic. Because of this, each cell provides a different and unpredictable amount of electrical energy. The goal of this research is to make an update to the design of a prototype device, which applies a uniform catalyst layer in the form of ink on a membrane, in order to achieve effective implementation. . The prototype was improved, being capable of painting a maximum of three hundred (300) square centimeters. Also, the servo motors was changed with stepper motors, they are harder to programing but have more torque to move all the painting mechanism without problems. The "servo" library in Arduino software environment was replaced with the function "stepperWrite()".This function keeps updating global variables that stores the position of each stepper motor, as they do not have position sense, global variables are needed to count each motor step for each motor. The function can choose the motor I want to move, how many units I want to rotate, how many steps have each unit (scale, 200 steps per turn) and the global variable that stores the step count for that motor. In that way, we can control a stepper motor in the same way we can control a servo: using only a position or angle number. Thus, we can significantly improve the reproducibility in the preparation of MEA's, thus achieving optimize the preparation thereof.

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Chemistry Presenter: Vazquez, Alexandra

Mentor: Tinoco, Arthur

Title: Determining Ti(Deferasirox)2 superiority over Deferasirox as a potential anticancer agent

Authors: Sergio Loza Rosas (University of Puerto Rico, Rio Piedras), Alexandra M. Vázquez Salgado (University of Puerto Rico, Rio Piedras), Arthur D. Tinoco (University of Puerto Rico, Rio Piedras)

Abstract

Titanium based complexes have been promising anti-cancer drugs since the early 1980s, but their hydrolytic instability at physiological conditions has made it difficult to achieve more advanced faces in clinical trials. Even though transferrin (Tf), the Fe(III) transport protein, accomplishes Ti(IV) stability and carries out the transportation function, the cytotoxicological activity of the Ti(IV) in cancer cells wasn't significant. Deferasirox, drug currently used as an iron chelator, is a ligand that could act as a Tf biomimetic, a molecule that imitates the binding site and that offers the same stabilizing and transporting function. The proposed pharmacological design suggests that once the Ti(Deferasirox)2 complex enters the cell, metal exchange of the Deferasirox and Ti(IV) will occur, based on the ligands higher affinity to Fe(III) than with Ti(IV). Even though Deferasirox must prove higher affinity to Fe(III) than to Ti(IV) it still must be able to coordinate into a stable complex at physiological conditions with Ti(IV) for the possible transportation of the complex into the cell. Preliminary results using UV-Vis Spectrophotometry show that a reaction between Ti(Def)2 and Fe(Citrate)2 occurs after 24h. The time lapse for the reaction to take place is slow enough so that it gives the complex time for a stable transportation to the cell. Ti(Def)2 and Def were both reacted with a more physiologically relevant source of Fe (III), Fe2Tf. For Ti(Def)2 and Def with Fe2Tf, no significant displacement in the signals was noticed. Results suggest that even though Ti(Def)2 and Def react similarly when faced with different metal sources, Ti(Def)2 proves superiority with its ability of delivering Ti(IV) intracellularly. Cell viability assay results show that Def demonstrates an unstable behavior in its cell viability effect given that the ligand caused an increase in the proliferation of normal cells (MRC5) and even cancer cells (A549), proving again Ti(Def)2 superiority over the ligand by itself as a potential anticancer drug.

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Chemistry Presenter: Vazquez Moreno, Noralejandra

Mentor: Sanabria, David

Title: Encapsulation of a nitrochalcone into PLGA nanoparticle and its potential as anticancer agent

Authors: Noralejandra Vázquez (Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus), Gamalier Dominguez (Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus), Hector Maldonado (Department of Pharmacology, Universidad Central del Caribe School of Medicine), Beatriz Zayas (School of Environmental Affairs, Universidad Metropolitana), Lisandro Cuncci (School of Science and Technology, University of Turabo), David J. Sanabria-ríos (Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus)

Abstract

Curcumin is a yellow poliphenolic compound that has proven to be effective as treatment for certain types of cancer. However, consuming dietary curcumin shows poor bioavailability due to rapid metabolization by the body. Due to the pharmacokinetics limitations above, compounds with similar chemical structure to curcumin were prepared with the objective of prolonging the presence of these compounds in the blood plasma and thus increasing their therapeutic action. In our research we have synthesized several nitro chalcone compounds with similar structure of curcumin. Among these compounds, nitro chalcone 3b displayed interesting anticancer activity against both prostate and colorectal cancer cells. This research is intended at employing PLGA NP´s to improve the delivery of 3b- nitrochalcone in both prostate and colon cancer cells. To accomplishes this goal, we prepared and characterized PLGA-NP's containig 3b through a single emulation evaporation methodology described in the literature. Then, 3b-PLGA NPs were analyzed by scanning electron microscope (SEM) and Zetasizer approaches. The anticancer activity of 3b-PLGA NPs against colorectal cancer cells also was studied. Results of this research will be discussed.

Acknowledgement: This Project was supported by NIH-PR INBRE (Grant # 2P20GM103475-14)

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Chemistry Presenter: Vega, Karlene

Mentor: Nicolau, Eduardo

Title: Nanocellulose based nanodiamond constructs as precursors for forward osmosis membrane applications

Authors: Karlene Vega Figueroa (University of Puerto Rico, Río Piedras Campus), Perla Cruz Tato (University of Puerto Rico, Río Piedras Campus), Dr. Edwin O. Ortiz (University of Puerto Rico, Río Piedras Campus), Dr. Eduardo Nicolau (University of Puerto Rico, Río Piedras Campus)

Abstract

Forward osmosis (FO) has proven to work efficiently in liquid separation by using the energy produced by the osmotic pressure of aqueous solution. Nonetheless, the absence of membrane technology powered by the FO process hinders the need for advanced research in such area. To address present limitations, this work focuses on the fabrication of FO membranes by using a polysulfone (PSF)/polyester (PE) mesh membrane backbone that is known to provide high performance due to its high permeability and water flux. Consequently, in this research we proposes to use silylated cellulose nanocrystal (CNCSi) based diamond nanoparticle (DNP) constructs as precursor components for the active side of the film. Specifically, cellulose's role in environmental remediation is based on its mechanical properties, which gives certain rigidity to the membrane, as well as its hydrophilicity. Similarly, DNP's antimicrobial activity is crucial in preventing the spread of pathogens throughout the purification process. Moreover, their high surface functionalizability enables the membrane to target specific contaminants present in water. The development of these novel FO membranes involves the preparation of a strong support system to later incorporate a CNCSi-DNP composite on the active side of the material via a sol-gel preparation. As a first approach, the EDC-linker mediated covalent coupling of silylated cellulose and DNP's as well as the characterization of the composite took place. Fourier transform infrared spectroscopy (FTIR) was used to ascertain the formation of the strong peptide bond generated between the amine present in CNCSi and the carboxyl group in DNPs. Although not 100% yield, a peak at 1633 cm-1 in the FTIR spectrum demonstrated a successful reaction. Consequently, the membrane was produced through the phase inversion technique and tested through FO setup tests using a 5% NaCl solution. The system demonstrated an 8.5 LMH water flux while the commercial HTI membrane exhibits a 5.48 LMH flux. As future works, microbiological assays would prove the construct's antimicrobial capabilities. Further membrane characterization would include Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and porosity analysis. Also, the incorporation of the CNCSi-DNP construct with the support system would be necessary to determine CNCSi-DNP's effect on the permeability and water flux of the membrane.

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Chemistry Presenter: Vega Collazo, Brian

Mentor: Cabrera, Carlos

Title: Exfoliated MoS2 for Dye Sensitized Solar Cell

Authors: Brian Vega Collazo (University of Puerto Rico Río Piedras Campus), Camila Morales Navas, Carlos Cabrera

Abstract

One of the biggest challenges in the world is the develop of alternative sources of energy and innovative achieve to replace the currently one in use (hydrocarbons) as would be the transformation of the radiation emitted by the sun into electrical energy using materials such as Molibdenum disulfide (MoS2) in photoelectrochemical cells. The arrangement of this semiconductor material is based on a Molibdenum atom hexagonally surrounded by another six tungsten, which in turn is compacted on both sides by a flat hexagonal selenium layers.

The energy production process consists in synthesizing LixWSe2 from n-butyllithium and MoS2. It is followed by an exfoliation with water to create a separation of layers of WSe2 to work as an anode in solar cells. The preparation of solar cells based on TiO2 deposited on indium tin-oxide and then heated to a certain temperature. Then, we deposited MoS2 over TiO2 and repeat the process to form the anode. In another indium tin-oxide, amorphous carbon is deposited to be used as a cation. After that, both electrodes are compacted and dropped a drop of electrolite solution prepared in acetonitrile with LiI and I2 and put it in the ICPE for some minutes to have the results.

Thanks to Raman spectroscopy, ICPE and XRD this experiment was successfully. We can determine the thickness of WSe2 layers and if is possible to use it as material to absorbe solar energy to make the change to electrical energy.

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Chemistry Presenter: Vera Rosado, Adelfa A.

Mentor: Colon, Jorge

Title: Intercalation of Ferrocene Derivatives into Zirconium Phosphate Layers for Drug Delivery Applications

Authors: Adelfa A. Vera Rosado (University of Puerto Rico, Río Piedras), Jorge L. Colón (University of Puerto Rico, Río Piedras), Bárbara Casañas (University of Puerto Rico, Río Piedras), Ingrid Montes (University of Puerto Rico, Río Piedras), Juan C. Aponte (University of Puerto Rico, Río Piedras)

Abstract

The study and research of the biomedical applications of nanotechnology has been up and rising during the last decade. One active field of investigation is the use of nanoparticles as an alternative, targeted drug delivery system, particularly for the delivery of chemotherapeutic drugs for cancer treatment. Zirconium phosphate (ZrP) is a layered inorganic nanomaterial that intercalates organometallic compounds. In its alpha phase (?-ZrP), it is monohydrate (Zr(HPO4)2•H2O) with an interlaminar distance of 7.6 Å. However, in its hydrated theta phase (Zr(HPO4)2•6H2O, ?-ZrP), the interlaminar distance expands to 10.3 Å, and has been previously reported in our laboratory for its use in drug carrier applications. Ferrocene and ferrocene derivatives are redox-active compounds that have been used as electron mediators in amperometric sensors, and are organometallic compounds that have been intercalated in zirconium phosphate. Both the ferrocenyl chalcone, Fc-N(CH3)2, which has antiplasmodial activity, and the ferrocenyl chalcone analogue, ferrocene-indanone, which has shown cytotoxicity activity against cancer cells in previous studies, have been intercalated successfully into ?- ZrP at different ratios, in order to optimize the intercalations. The characterization of the intercalation products was done using X-ray powder diffraction (XRPD), and the results show expanded interlayer distances of 9.70 Å for Fc-N(CH3)2 and 9.96 Å for Fc-Indanone. The in-vitro drug release experiments have been started using PBS buffer at different pHs to study the release response of the ferrocene derivative-intercalated ZrP. The characterization of the Fc-N(CH3)2 and the ferrocene-indanone intercalation product, using cyclic voltammetry (CV), Fourier Transform-Infrared spectroscopy (FT-IR), electronic spectroscopy (UV-vis and diffuse reflectance), and energy dispersive X-ray spectroscopy (EDS) by means of scanning electron microscopy (SEM) are underway as well. The long-term goal of the laboratory is to develop new controlled drug release carriers using zirconium phosphate.

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Chemistry Presenters: Yu De Jesus, Crystal L Fonseca Montes, Angelica A.

Mentor: Infante, Ricardo

Title: Synthesis of the new 2-methylbenzimidazole derivatives with potential biological activity

Authors: Crystal L.yu De Jesús (UPRA), Angélica A. Fonseca Montes (UPRA)

Abstract

Benzimidazole is an important synthetic precursor in the discovery of new drugs with anti-viral properties, anti-carcinogenic, anti-microbial, anti-bacterial, among others. These therapeutic properties highlight this pharmacophore to be used in the search of the synthesis of new compounds with potential bioactivity. Through this research, 2-methylbenzimidazole (2-MBZ) was coupled with two different organic molecules that have therapeutic properties that makes them attractive compounds for possible new. The chosen substituent are 4-(chloroacetyl)morpholine and 6-chloroacetyl-1,4-benzodioxane. The 4-(chloroacetyl)morpholine compound is present in many different drugs that are used for treating multiple sclerosis and psoriasis, it is also used for DNA repair in malignant tumor cells and as an inhibitor of HIV integrase. The other substituent, 6-chloroacetyl-1,4-benzodioxane, has been chosen since it is used in many antibiotics, anthelmintic and insecticidal compositions. Prior to synthesis, theoretical studies were performed both to 2-MBZ as to the substituents 4-(chloroacetyl)morpholine and 6- chloroacetyl-1,4-benzodioxane. Computational chemistry was used to predict the electronic chemical and magnetic properties of this derivatives using Density Functional Theory (DFT) method and the B3LYP functional. The obtained data was collected, tabulated and thoroughly study. This data is used for the characterization and prediction of the behavior of the molecule that will be obtain when the organic synthesis of the substituents takes place with the 2-MBZ using physical methods that will be contrast with the theoretical calculations.

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Chemistry Presenters: Zorrilla Veloz, Rocío Rivera, Kevin E.

Mentor: López-Mejías, Vilmalí

Title: Biocompatible-Tailored-Nanocrystals-Drug Nanocarriers for Colorectal Cancer Treatment

Authors: Vilmalí López-mejías (University of Puerto Rico, Rio Piedras Campus), Rocío Zorrilla Veloz (University of Puerto Rico, Rio Piedras Campus), Kevin Rivera Galán (University of Puerto Rico, Rio Piedras Campus)

Abstract

This project is directed to improve the current strategies for polysaccharide-based drug carrier systems, by understanding the encapsulation of polymorphs (different crystal forms) of hydrophobic active pharmaceutical ingredients (APIs) on natural polymers, specifically alginate and chitosan. The scope of work addresses issues that pertain the poor bioavailability following oral administration of cancer- related therapeutic agents by developing a novel nanoformulation strategy based on these two polysaccharides. The proposed methodology offers a dual improvement over current formulation strategies for cancer-related therapeutic agents because it improves solubility, and hence bioavailability, by 1) increasing the surface area of the solute through the reduction of the size of the crystals into the nano-scale range and 2) providing selective access to energetically viable polymorphs, which in many cases offer better solubility for an API. Chitosan-Ca-alginate blended nanoparticles have been chosen for this study as they have already been used for colon-specific drug delivery. Attempts to develop the nanoparticles using both alginate and chitosan blends will be discussed. Chitosan-Ca-alginate blended particles have been characterized using optical microscopy, and scanning electron microscopy (SEM). Thus far, the smallest particle developed average 920 nm, therefore, further optimization is needed. Furthermore, a systematic crystallization procedure for the discovery of specific polymorphs of colorectal cancer-related therapeutic agent (5-Fluororuracil) has been developed under a 2D setup utilizing polysaccharide coated surfaces to be later used on the actual nanoparticles. To develop this crystallization procedure the solubility of the drug has been determined at 37 C using Class 3 solvents. Based on the solubility data, the cooling crystallization method has been chosen. The outcome of the crystallizations has been analyzed using optical microscopy, Raman spectroscopy, and powder X-ray diffraction to reveal possible drug-polymer interactions, as well as the polymorph crystallized.

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Computer Science

123

Computer Science Presenter: Collazo Martis, Ramón L.

Mentor: Arce-Nazario, Rafael

Title: Combinational Circuit Optimization for the Rijndael S-box

Authors: Rafael Arce-nazario (UPR-RIO PIEDRAS), Ramón L. Collazo-martis (UPR-RIO PIEDRAS)

Abstract

Circuit optimisation is the process of reducing the depth and number of gates in a Boolean circuit. It is particularly important in the implementation of cryptographic procedures because by reducing the number of gates, the processing time and energy utilization are reduced. Circuit optimisation is an NP- complete problem, thus we must rely on heuristic algorithms to solve it. In this work we study the method and heuristics proposed by [BP10] to optimise the parts of the Rijndael S-box, which is a key component of the Advanced Encryption Standard (AES). We have implemented the algorithm and validated its results. We are in the process of adapting it to try to minimise the inverse S-box in terms of the number of XOR gates used.

[BP10] Boyar, J., Peralta, R.: A new combinational logic minimisation technique with applications to cryptology. In: Festa, P. (ed.) SEA 2010. LNCS, vol. 6049, pp. 178–189. Springer, Heidelberg (2010)

Computer Science Presenter: Garcia Herrera, Yaileen M.

Mentor: Guzmán Blas, Rolando

Title: Empirical Model of Polymer Electrolyte Membrane Fuel Cells (PEMFC) using Scilab

Authors: Yaileen M. García Herrera (University of Sacred Heart), Leilani M. Lotti Díaz (University of Sacred Heart), Krystel Ocasio Norat (University of Sacred Heart), Dr. Rolando P. Guzmán Blas (University of Sacred Heart)

Abstract

The technology of fuel cells has received much attention in recent years due to its high efficiency and low emissions. There are different types of fuel cells, in our case we will focus on the Polymer Exchange Membrane Fuel Cell (PEMFC). Hydrogen or alcohol can be used in these cells as fuel for the anode and air or oxygen for the cathode. Simulations and models are helpful for developers of fuel cells because it can help improve the design of fuel cells as well as reduce costs, optimize and make them more efficient. 124

A good model should predict the performance of fuel cells in a wide range of operating conditions. Some important parameters to include in a fuel cell model are the cell temperature, fuel temperature, temperature of the oxidant, the pressure of fuel or oxidant, voltage and electric current of the cell, and the fraction weight of each reagent. It is possible to develop models and simulations using Scilab program. The fuel cell models obtained will be used to fit the experimental data and use it as an analytical tool that describes the characteristics of voltage vs. electricity in a fuel cell.

Computer Science Presenter: Ponce García, Kevin J.

Mentor: Valenzuela-Andrade, Eliana

Title: Using RobotC on Lego MindStorm

Authors: Kevin J. Ponce García (University of Puerto Rico at Arecibo)

Abstract

Robots are becoming an integral component of our society and have great potential in being utilized as an educational technology. The purpose of the projects is to develop a workshop series, based on the LEGO NXT Mindstorms and RobotC platform for the basics concepts of programming. The goal is to motivate young Puerto Rican students to consider career in any field of STEM. In order to do it, we prepared a guide to assembling a NXT robot and a set of presentations that provide the main foundations of the programming to the students. We also developed a guide for the mentor to ensure that these tools may spread widely in the future.

From the references used we get that we can increase diversity in computing by engaging females and underrepresented minorities with peer support and other activities that retain and transition them to the computing workforce. Also, undergraduate programming classes attempts to engage the students in problem-solving and team working activities led the students wishing to extend their skill beyond those that are taught in the course and push themselves to produce work which far exceeds the requirements of the course.

In conclusion it is expected that our work can provide the positive impact and help reduce the deficit on STEM carriers especially on Hispanic students. For our future work, we hope to get feedback on the work we developed by students of Puerto Rico and be able to do continuous improvement over the material.

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Computer Science Presenter: Rodríguez Rivera, Amaury O.

Mentor: Latorre, Edward

Title: Mobile Application Development in iOS for the Community of UPRA

Authors: Amaury O. Rodríguez Rivera (UPR-ARECIBO), Cheylianie Rivera Maldonado (UPR- ARECIBO), Yaraliz Mercado Bernier (UPR-ARECIBO)

Abstract

Our objective is to develop the application Pregunta Lobo for the iOS system. This application has three different sections which are questions-answering, student associations and the map. These sections will keep the users informed about every important details about the University of Puerto Rico in Arecibo. We started by researching the requirements for developing an iOS application. It is possible to create a native app using the Xcode IDE or third party alternatives, but all of them require the use of a Mac and an Apple developer account in order to upload the application to the App Store.

For this project, we decided to use Apple's new programming language, Swift. We implemented the question-answering section, which uses a natural language processing algorithm and an SQLite database to respond to questions related to the institution. Also, as an improvement to the original version in Android, we designed additional databases for the student associations and map sections. Furthermore, the application meets the interface requirements of all iOS devices.

Currently, we are working on a method to obtain user feedback and usage data, and send this information to our web server. The purpose is to know which questions are being asked by the users, if the application is answering correctly and which questions should be added into the database. Likewise, the student associations and map localizations viewed by the users will also be gathered. In addition, we are researching ways to improve our natural language processing system using probabilistic methods.

As a future plan, we shall add to the application a system of notifications. We expect to upload Pregunta Lobo into the App Store by spring 2016.

Computer Science Presenter: Rosado Martínez, Génesis

Mentor: Valenzuela-Andrade, Eliana

Title: Alice 3 as a Learning Strategy to Engage Students to Computer Science Careers

Authors: Génesis Rosado-martínez (University of Puerto Rico at Arecibo) 126

Abstract

Alice3 is a 3D drag and drop free programming environment design for creating animations which we are using to design an attractive curriculum for students. Our material will contain a variety of lessons that will help students to learn how to program and it also introduces them to basic but important concepts of computer science and arts, logics skills, creativity, behind other. Our project involves the development of material for teachers that will train them, video tutorials that will guide teachers and students to make the process easier, presentations, and rubrics. To start with this learning process we will give workshops to prepare teachers, visit students at schools which will show us if they are interest on the material and also give us their feedback to make improvements. The main goal of this project is to attract students that are interesting in different study areas to also promote how their future could be is they choose STEM careers which involve a lot of team work. Finally, we are looking forward to encourage teachers, students, very special to girls in STEM which are very important. As a future work, we will do summer camps, workshops, and Saturday academies for students, girls, and teachers where we will use the material that we developed during this project.

Computer Science Presenter: Santana Roman, Jesus

Mentor: Valenzuela-Andrade, Eliana

Title: Using RobotC on Tetrix

Authors: Jesus J. Santana Roman

Abstract

he purpose of our project was to develop innovative strategies to motivate young students in Puerto Rico to consider a career in STEM areas.

In this case ROBOTC was used as the basis for programming with the Tetrix and Lego Mindstorms NXT platforms. In addition, the literature review that where done gave us successful examples of this type of practice, for both students and teachers in other places, and gave us ideas on how to actually make these initiatives for students in Puerto Rico a reality.

This project includes the familiarization with the ROBOTC development platform, and the TETRIX with NXT robotics education platforms A series of workshops on topics were developed such as: security, project management, teamwork, RobotC for Tetrix, robot assembly, motors, gears and sensors; using presentations, assembly guides, guides for teachers, challenges and solutions.

With these workshops we also expect to improve skills such as creativity, problem solving, real-world applications of physics and geometry plus the development of computational thinking that the K-12 127

curriculum today do not have and are considered important to increase the probability of success of young Puerto Ricans as Professional.

The combination of Tetrix and ROBOTC present a great opportunity to continue the development of innovative learning tools not only for K-12 students but also university students, since we can make from simple applications to more complex ones in different robotics platforms. As for our future work, we hope to collect feedback from students and teachers in order to improve the instruments made.

Computer Science Presenter: Santos Freytes, Ezequiel

Mentor: Latorre, Edward

Title: Pregunta Lobo, the Mobile Personal Assistant for the UPRA Community

Authors: Ezequiel Santos Freytes (UPR-Arecibo), Emmanuel Castro Soto (UPR-Arecibo), Daniel Damudt Galera (UPR-Arecibo), Carlos Nieves Cardona (UPR-Arecibo), Rafael Sierra Soto (UPR-Arecibo)

Abstract

The purpose of this work was to identify the needs of our university's students and develop a mobile application that would provide a notable solution that would respond to these needs. We identified that a main need in our university was obtaining all kinds of information related to everyday activities. We researched the most frequently asked questions of our community through interviews of the faculty, students, and other campus personnel, and by gathering information from the multiple university resources. Through this study, we developed the most comprehensive university information source for students. We then studied the alternatives to provide this information in the most effective method and decided to build three modules, i.e., natural language interface with text and voice inputs, a campus map with location based information and a student organization list. Our first prototype was built as an Android app and released to the campus community during promotion events, where we gathered user feedback. We also obtained anonymous usage feedback using a web-based data collection process we designed. We obtained close to 100 installs which provided data on the user questions, the app features used and overall user satisfaction. Our data shows that the average user has accessed the app over 5 times, with about half of these using the FAQ module. Our future plans include improving the natural language algorithms, adding a notifications modules with a web-based input system to provide users with the latest campus events, and completing the iOS version.

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Electronics

131

Electronics Presenters: La Santa Maldonado, Anthony Jr. Rodriguez, Jose

Mentor: Sanchez-Rios, Ismael

Title: Implementation of Electronic Components to Control the Operation of a Mono Piston Internal Combustion Engine of four Cycles

Authors: Anthony La Santa Maldonado (UPR-BAYAMON), Jose Rodriguez Valentin (UPR- BAYAMON)

Abstract

Electronics is one of the branches of science that has most evolved and keeps growing each passing day. It deals with the development and application of devices that work by using the flow of electrons. This can be found implemented on simple tools like electronic drills and amplifiers to more complex systems like computers, and the automation of processes in an industry. Nowadays, technology consists of the integration of different branches of science working together in harmony, leading to the advancement and discovery of new ways of cutting edge technology. This presentation will provide an overview of the purpose of our research and a detailed explanation of the process and steps necessary for the automation of a lathe machine using microcontrollers, which will be used for the creation of a disk and a set of stubs of different materials to make a disc clutch for the engine of four cycles. It will also provide schematics of the circuit boards and flowcharts of the programming code currently implemented on the lathe machine.

Electronics Presenter: Ortiz, Deliris Nairy

Mentor: Pinto, Nicholas

Title: Schottky diode based on WS2 crossed with PEDOT/PSSA

Authors: Deliris Nairy Ortiz Ortiz (University of Puerto Rico at Humacao), Nicholas J Pinto (University of Puerto Rico at Humacao), Carl Hugo Naylon (University of Pennsylvania), A. T Charlie Johnson (University of Pennsylvania) 132

Abstract

An easy technique to fabricate a Schottky diode with WS2 and PEDOT-PSSA under ambient conditions is presented. WS2 is an air stable transition metal dichalcogenide semiconductor. When connected as a field effect transistor, WS2 exhibited n-type behavior with a charge mobility of \textasciitilde 7cm2/V-s on SiO2. PEDOT/PSSA is a conducting polymer that can be electro-spun to form fibers with a conductivity of \textasciitilde 1 S/cm. In this work we fabricated a Schottky diode by crossing a CVD grown monolayer WS2 crystal with a single electro-spun PEDOT/PSSA fiber. The resulting diode characteristics were analyzed assuming the standard thermionic emission model of a Schottky junction. Analysis of the results includes the ideality parameter of 4.75, diode

rectification ratio \textasciitilde 10, and a turn on voltage of 1.4V. Efforts to investigate if these parameters are tunable with a back gate will also be presented.

Electronics Presenter: Ortiz Flores, Luis A.

Mentor: Vedrine, Josee

Title: Alignment of P3HT:ICBM active layers for improved optical and solar cell device efficiency.

Authors: Luis A. Ortiz-flores (University of Puerto Rico at Humacao), Gabriel A. Calderon-ortiz (University of Puerto Rico at Humacao), Josee Vedrine-pauléus (University of Puerto Rico at Humacao)

Abstract

Fabrication of large area solar cells on printable and flexible substrates using organic photovoltaic (OPV) devices is a developing field, and increasing device efficiency is coupled to understanding their functional chemistry and nanoscale-engineered properties. With this information, we can to identify these properties and use them to develop new and improved devices. In our research, we align the OPV thin polymer film surface to study absorption and transmission properties that can improve solar efficiency. Our interest is to analyze the behavior of these aligned polymers, particularly, that of P3HT fibrils within a network of ICBM matrix. We expect this process of cell fabrication will facilitate the flow of current through the active layer to increase solar devices efficiency. We will use characterization tools such UV-Vis, FTIR, XRD and AFM spectroscopies.

133

Electronics Presenter: Pérez Rosario, Héctor David

Mentor: Gonzalez-Sanchez, Juan

Title: Electrospinning Magnetic Design to make Polymer Nanofibers

Authors: Dr. Juan Gonzalez-sanchez (University of Puerto Rico-Bayamon (Profesor)), Hector David Perez-rosario (University of Puerto Rico-Bayamon (Student)), Suilan Roman-sang (University of Puerto Rico-Bayamon (Student)), Fernando Vargas-jimenez (University of Puerto Rico-Bayamon (Student))

Abstract

This study attempts to presents results of synthesized polymeric nanofibers by using a Magnetic Field Assisted Electrospinning (MFAES) setup designed with a MakerBot 3-D Printer. First, we designed full set up by using AutoCAD and MakerBot printing software. We implemented a Van de Graaff generator to obtain the higher voltage necessary to accomplish the electrospray and electrospinning in the solutions. We created two Helmholtz coils in order to obtain the uniform magnetic field with 300 turns with copper wire. After building the first prototype, we diluted the PVDF using alcohol and acetone separately obtaining a viscous solution of 15 wt. % calculated by using in house dilution software application. We took our first samples using aluminum foil as a substrate to be further physical analysis.

Electronics Presenter: Vargas Jimenez, Fernando L.

Mentor: Gonzalez-Sanchez, Juan

Title: Digital Controller of Magnetic Field Assisted Electrospinning

Authors: Juan Gonzalez Sanchez (UPR Bayamon), Fernando Vargas Jimenez (UPR Bayamon), Suilan Roman Sang (UPR BAyamon), Hector Perez Rosario (UPR Bayamon), 5

Abstract

Our project is to design an electronic control system by using Arduino microcontroller to be implement in a Magnetic Field Assisted Electrospinning. Our goal is to get full automatization of the electrospinning process by adjusting the speed of the needle or changing the time of deposition. We used stepper motors with a driver controller called L298H which is attachable to the Arduino board. To control the speed and direction of the needle, we added a nunchuk controller and a LCD screen to keep track of the coordinates and information related to deposition. 135

Engineering

137

Engineering Presenter: Alomar Otero, Osvaldo

Mentor: Calderón Arteaga, Hermes E.

Title: Design and Construction of a Seismic Table

Authors: Osvaldo Alomar Otero (STUDENT), Dr. Hermes E. Calderón, Advisor

Abstract

This project involves the design and construction of a seismic table for educational purposes, as a contribution for the Structural Analysis course. The goal of this work is the realistic modeling of earthquake loads based on the selection of three different earthquake events for the last 15 years. This is going to be done by developing patterns identified with the name of country and date when each event occurred. Each pattern is going to be designed and developed to virtually recreate the spectral acceleration and displacement of each event acting on high raised buildings. This valuable project is to challenge and inspire civil engineering students to design safe structures and engineering controls based on earthquake loads.

Keywords:

Design, Construction, Seismic Table, Pattern

Engineering Presenter: Baez Montanez, Alexander M.

Mentor: Caiseda, Carmen

Title: Optimizing aerial stability simulation of quadcopters

Authors: Alexander M. Baez Montanez (Interamerican University of Puerto Rico Bayamon Campus), Kathleen Mclane (George Mason University), Byong Kwon (George Mason University), Nithin Ellanki (George Mason University), Carmen Caiseda (Interamerican University of Puerto Rico Bayamon Campus), Padmanabhan Seshaiyer (formerly George Mason University; now National Science Foundation)

Abstract

At any given moment our world encounters challenging events that affect our natural resources, wildlife or human populations. Many companies, in their search for mitigating the impact of these events, 138

have invested in the advancement of technology that will allow them to manage these assignments, and such advacements include the development of more accurate UAVs (unmanned aerial vehicles). With the use of these vehicles wider perspectives and regions of our planet can be efficiently monitored at a safe distance. The moisture level of crops can be measured, water rafts can be delivered to people in distress at sea or an area can surveyed for suspects. These devices, being radio controlled or autonomous, have the great benefit of being maneuvered into difficult regions, but in contrast, they also demand faster response time in the job appointed. In our collaborative effort to improve the UAV's performance while airborne, we have undergone the task of investigating the flight dynamics of this machine. We have studied the Newton-Euler equations of quadcopter flight implemented within a MATLAB simulation and visualization with PD Control, conducted case studies on the stability of this UAV and compared the differences in stability behavior when utilizing different numerical methods.

Engineering Presenter: Barreto-Rodriguez, Erick

Mentor: Pagan Torres, Yomaira

Title: Quantum Mechanical Study of CO2 and CO Hydrogenation on Cu(111) Surfaces Doped with Ga, Mg, and Ti

Authors: Maria Curet-arana (UPRM), Yohaselly Santiago-rodriguez (UPRM), Erick Barreto- rodríguez (UPRM)

Abstract

Currently, a growing effort towards counteracting the negative effects brought by rising carbon dioxide (CO2) concentrations in the atmosphere is taking place. Excess of greenhouse gases can radically change our planet ecosystem, it's agriculture and the way every animal and plant lives in it, that is, if it does not kill us first. Noting the relevance of such effort, time and resources are being invested in trying to accelerate this area to a point where the human species (the main cause of such excess) finally becomes a carbon neutral inhabitant of the only planet we have, yet.

This problem arises from the use of fossil fuels as the main chemical for most of our energy needs. This problem is trying to be addressed by wind and solar power generation, but such technology suffers the handicapping property of not being financially efficient for the extensive propagation in large areas needed by current demands. Even if this was not a problem, the use of such areas would inhibit land of being agriculturally productive.

The most efficient way however, is the energy conversion and storage inside bonds created in chemical reactions. All the carbon needed for the creation of fuels for such purpose is being liberated in large quantities by us in the atmosphere since the industrial revolution. For this, our research is looking for the way to store energy by hydrogenating CO2 to useful fuels and chemicals. This is not in any way a 139

new process, since it is currently being done industrially, but again at a high cost due to the energy input needed for a high pressure and temperature reaction that only gives a 10% yield of Methanol. This chemical is of particular interest because it is the smallest alcohol and can be stored as liquid and directly used in combustion engines or as feedstock for other reactions. This research is investigating the way we could have an ambient pressure hydrogenation of CO2 to methanol by using a metallic alloy catalyst which lowers the energy input required and improves the process for higher yields and different pathways for chemicals other than methanol. The way this is being done requires density functional theory (DFT) in order to understand every step of the reaction kinetics and how they are affected by the interaction of the species with different metallic alloys.

Engineering Presenter: Bonet Santiago, Benny X.

Mentor: Acosta, Angel

Title: Cave Cartography: ZEB1 LiDAR and caveGEOmap.

Authors: Benny Bonet Santiago (Physics and Chemistry Department, University of Puerto Rico at Arecibo), Angel Acosta (Physics and Chemistry Department, University of Puerto Rico at Arecibo)

Abstract

Our research group are developing and using two modern techniques to create 3D digital cartography of caves; these are: i) ZEB1 LiDAR and ii) caveGEOmap. Light Detection And Ranging (LiDAR) is being used to create 3-D cave maps. The Geoslam ZEB1 (3-D Laser Mapping) hand held mobile LiDAR was used to obtain the measurements. This system provides us with more than 40,000 data points per second in a totally random three-dimensional pattern with a 270o angular field of view. After the data collection, which provides us with millions of data points, a powerful computer and advance software are needed to create the 3-D high-resolution cave maps. Secondly, CaveGEOmap is a Matlab® code developed that uses basic surveyor cartography measurements to create 2-D and 3-D maps of the cave with minimal user interaction. Commonly, a cave cartographer will use a digital laser distance measurer, clinometer and a compass to obtain the measurements of the cave, however this method is time consuming and as a result few measurements are usually obtained. Our method consisted in measuring distances as a function of the azimuth and inclination for a total of 54 data points per station. Then, caveGEOmap evaluates the given measurements using Spatial Analysis and uses the data itself to estimate the necessary variables to produce the 2-D and 3-D cave maps. In this study, both methods will be presented and compared (based on data points collected, quality of data, time, cost effectiveness, maps created and surveying difficulties) for caves in the north coast karst belt region of Puerto Rico. In conclusion, comparisons between two modern cave cartography methods were used for this study and the main objective was to verify if caveGEOmap (uses basic surveyor measurements, is time consuming 140

and inexpensive) method is comparable to the ZEB1 LiDAR (high quantity data collection, expensive and less time consuming) method.

Engineering Presenter: Bonilla Alvarado, Harry

Mentor: Carbajal, Gerardo

Title: Vertical-Axis Wind Turbine (VAWT) Design for Integrated Light Pole Wind Turbine Systems

Authors: Harry Bonilla Alvarado (Universidad del Turabo)

Abstract

The present paper contributes to the modeling of unsteady flow analysis of vertical axis wind turbine for urban application. Double Multiple Stream Tube model was applied for the performance prediction of straight bladed fixed pitch VAWT at low wind speed. Numerous of airfoils were analyzed, five airfoils were chosen because of their camber, symmetry and drag polar performance. Afterward the turbine geometry was selected using an iterative process with the different length parameters. The following parameter were constraint to a distance of 1.5m by 1.5m. Q-Blade open-source software for wind turbine analysis was used to iterate the different design parameter, this program makes used of Double Multiple Stream-tube Model for the analysis. The radius, height and chord were varied and the best performing geometry was picked with a radius of 0.7m, 1.2 height and 0.25 chord length. The airfoils used for the design process were the DU 06-W-200, NACA 0012, NACA 23015, NACA 24112 and OAF095. The NACA 23015 airfoil had the best performance with a power coefficient of 0.41 and approximately 85 Watts at wind speed of 5.50 m/s.

Engineering Presenter: Burgos Rossy, Edwin A.

Mentor: Almodovar, Jorge

Title: Evaluating the effect of degree of crosslinking and RGD peptide over cellular adhesion in combinations of polymeric bilayers

Authors: Edwin Burgos-rossy (University of Puerto Rico-Mayaguez), David Castilla (University of Puerto Rico-Mayaguez), Jorge Almodovar (University of Puerto Rico-Mayaguez) 141

Abstract

Bioactive coatings prepared with polymers that simulate the extracellular matrix composition are known to increase biocompatibility and cellular adhesion of implantable biomaterials. Understanding and employing the electrostatic behavior of polymers, multiple polymeric multilayers have been engineered. Applying the layer-by-layer technique, biomaterial surfaces have been successfully coated, thus improving the biocompatibility, compared to uncoated biomaterials. In search of new options that augment the biocompatibility of a surface and generate a more suitable environment, the objective of this work is to evaluate the effect of crosslinking in polymeric multilayer combinations and the addition of a peptide to the multilayers. In this study, multilayers of chitosan and heparin with top layers of heparin-maleamide and heparin-RGD peptide were evaluated. After preparing six bilayers, the multilayers were crosslinked using carbodiimide (EDC/NHS) chemistry at varying concentration. RDG peptide functionalization was carried out using maleimide chemistry in combination with EDC/NHS chemistry. Nuclear magnetic resonance (1H-NMR) was used to confirm effective conjugation of heparin with maleamide and heparin/maleimide with RGD. NIH-3T3 cells were used to assess biocompatibility and cell-adhesion. Fluorescence microscopy using Hoechst dye was used to assess cell adhesion. Our results indicate that non-crosslinked surfaces do not represent an attractive surface for cells. Multilayers crosslinked with 30 mg/mL of EDC showed improved cellular adhesion, having a preference in adhesion on HEP-terminated multilayers. Multilayers crosslinked with 70 mg/mL of EDC, showed increased cellular adhesion, independent of the combination of polymer/polysaccharide composing the multilayers. These results demonstrate that polymeric layers composed of HEP and CHI, with high degree of crosslinking provides a more apt surface for cellular adhesion. Studies utilizing NIH-3T3 cells show an increase in cellular adhesion in wells containing the heparin-RGD peptide combination. Our work has demonstrated that chitosan and heparin crosslinked multilayers functionalized with RGD peptide have higher cell adhesion, therefore increasing applications in the field of tissue engineering.

Keywords: RGD peptide, layer-by-layer, polysaccharide, biocompatibility

Engineering Presenter: Caro Suarez, Carlos

Mentor: Lugo Ortiz, Jose

Title: Visualization of CAD parts in Virtual Environments

Authors: Carlos E. Caro Suarez (University of Puerto Rico at Mayaguez), Ian Mendez (University of Puerto Rico at Mayaguez), Jose Lugo (University of Puerto Rico at Mayaguez)

Abstract

Recent advances on virtual reality reproduction have generated a new wave of applications. 142

The project's mission is to empower designers and innovators through the development of a tool that provides them with a Virtual Reality (VR) visualization mechanism before passing to the manufacturing or research phase. The VR system is composed of a Head Mounted Display (HMD), a PC with a dedicated graphics card, and controllers. The use of development kits and software licenses will enable the assembly of a relatively low cost VR system and product, which could lead to profitable sales.

The project is currently on the software development phase, which includes the implementation of an organic user interface, detailed guidelines to part files import, external devices configuration, effective visualization strategies, and part selection method. Our goal is to visualize CAD parts and assemblies in VR, currently in this first stage it is done by exporting CAD files into game engines available in the market. The goal is to be able to visualize CAD parts within CAD software.

The end product will be commercialized as a software toolbox for Computer-Aided Design software for the use of designers and researchers alike.

Engineering Presenters: Colón Reyes, Gabriel Enrique Gonzalez Afanador, Ian

Mentor: Ortiz Rivera, Eduardo

Title: Wind Power Systems: Optimization Characterization

Authors: Eduardo I. Ortiz Reyes (University of Puerto Rico, Mayaguez), Gabriel E. Colón Reyes (University of Puerto Rico, Mayaguez), Ian González Afanador (University of Puerto Rico, Mayaguez), Abraham J. González Román (University of Puerto Rico, Mayaguez)

Abstract

The purpose of this project is to design a charge controller that is able to optimize the electricity that is drawn by batteries connected to a wind turbine. This method prevents overcharging and at the same time helps avoid reducing battery performance. This is achieved by either disconnecting the system or dumping excess power into a dummy load. In cases like this, a portion of the energy generated is wasted. Commercial generators are found at moderate prices but the management of energy is not at its optimal efficiency. The motivation stems from the need to develop charge controllers that are able to take advantage of the energy produced at low wind speeds and reduce the need to dissipate energy at high wind speeds. The project's objective is to design and build an efficient charge controller that uses DC to DC converters and has the capability of taking advantage of low wind speeds. 143

Engineering Presenter: Corchado Albelo, Marcel F.

Mentor: Suarez, Oscar Marcelo

Title: Experimental Design Analysis of Stir Casting of Enhanced Aluminum Filler Reinforced with NbB2 Nanoparticles

Authors: Andrés F. Calle (University Of Puerto Rico, Mayaguez Campus), Christian Vázquez (University Of Puerto Rico, Mayaguez Campus), Jorge De Jesús Silva (University Of Puerto Rico, Mayaguez Campus), Marcel F. Corchado (University Of Puerto Rico, Mayaguez Campus), Oscar Marcelo Suárez (University Of Puerto Rico, Mayaguez Campus)

Abstract

This study focuses on the manufacture of a filler bearing NbB2 nanoparticles intended for aluminum welding. The nanoparticles were obtained by high energy ball mill fragmentation and mixed with aluminum powder. A central composite design of experiment allows assessing the effect of casting factors, namely melt stirrer speed and stirring time, and estimating a second-degree polynomial model, which enables the optimization of the manufacturing process. The filler wires are prepared with two nanoparticle levels (0.5 wt.% and 1.5 wt.% NbB2) and an Al - 5 wt.% Mg binary alloy. Filler rods with 2.4 mm in diameter are obtained via rolling and tested using the tungsten inert gas welding method. This research also evaluates the weld hardness, its porosity and microstructure via optical microscopy, to find the optimal manufacturing variables.

Engineering Presenter: De Jesus Villanueva, Nerida H.

Mentor: Padilla, Ingrid

Title: Water Quality for Rural Non-PRASA Communities in Puerto Rico

Authors: Nerida H. De Jesus (University of Puerto Rico- Mayaguez Campus), Arshley Rey (University of Puerto Rico- Mayaguez Campus), Angeliz Vangas (University of Puerto Rico- Mayaguez Campus), Isabelle Martinez (University of Puerto Rico- Mayaguez Campus) 144

Abstract

The project consists of conducting procedural water quality analysis for a local community who is not affiliated to the local AAA water Authority. The purpose consists of providing the hands on experience on planning, design, preparation and execution for the field sample collection and laboratory processing in order to obtain values for several parameter and assess the water quality. Several principal and secondary standards established by the EPA are used as a guideline for: pH, Turbidity, Temperature, Conductivity, DO, TOC, Arsenic, Chlorine, Total Coliforms, E. Coli, Phthalates and Volatile Organic Compounds. Additionally, the project provides the experience on community service and research translation

Engineering Presenter: Diaz, Miguel

Mentor: Carbajal, Gerardo

Title: Experimental Characterization of a 1.2 kW PEM Fuel Cell

Authors: Miguel A. Diaz (University of Turabo)

Abstract

A Nexa Power Module was experimentally tested for output performance and efficiency as a function of fuel consumption and load. The nominal output power operation according to the OEM was 1.2 kW with nominal DC voltages and currents of 26 V and 46 A respectively, whereas the net output power at 90% load capacity was measured at 1.17 kW with DC voltages and currents of 28 V and 41.7 A, respectively. Moreover, the efficiency of the power module varies by load percentage. The loads were varied from 0% to 100%, and the net efficiencies were calculated at 59.64% and 37.08% for these load percentages, respectively. Currently, the power module operates with an approximate inlet H2 pressure of 100 psi.

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Engineering Presenters: Díaz Resto, Kevin A. Rodríguez Nieves, Josué D.

Mentor: Yeckle, Jaime

Title: Cyber Security in Fluid Reservoir

Authors: Rafael Isaac Santiago (UIPRB), Brian Fernández Burgos (UIPRB), Jaime Yeckle (UIPRB)

Abstract

Security is a big issue for all networks in today's enterprise environment. Hackers and intruders have made many successful attempts to bring down high-profile company networks and web services. Now almost everything can be accessed remotely and can be also controlled. New kinds of vulnerabilities has emerged that threaten to damage many kinds of physical infrastructure. To maintain reliability in control systems with software components it has become a requirement to create systems dedicated to the protection of these CPS devices. In this paper, we show how using three security method can assure a more secure protection to any basic system. We use two security based techniques for attack detection and a third to oversee and analyze. The ?rst method utilizes specific set of rules to compare to environment. The second method filters data to analyze traffic. The results demonstrate the effectiveness of preprocessed the data and the use of dual security methods in the detection of the attack and normal operation modes.

Engineering Presenter: Esteves Klomsingh, Silvia T.

Mentor: Suarez, Oscar Marcelo

Title: High Strength Air Entrained Concrete Containing Nanoparticles and Aluminum

Authors: Silvia T. Esteves (UPR-MAYAGUEZ), Carlos M. Medina (UPR-MAYAGUEZ), Hildelix Soto (UPR-MAYAGUEZ), Oscar Marcelo (UPR-MAYAGUEZ)

Abstract

Air entrained concrete contains microscopic air cells that assists in the material durability of the concrete by decreasing the internal pressure when water freezes. Thus, this type of concrete is commonly used in cold regions that experience freezing temperatures. Because of such porosity, this concrete is not commonly used for structural applications. As a consequence, the goal of the present 146

research has been to formulate a high strength air entrained concrete mixture bearing better structural capacity. Such concrete mixture contained aluminum powder as an air incorporating agent and cementitious replacements, such as fly ash, to enhance the mechanical properties. Nanostructured SiO2 (nS) was added to counterbalance the strength loss since fly ash lowers the strength of concrete at early age. Specimens with 0.01%, 0.02%, 0.05%, and 0.08% of aluminum powder were tested in compressive and tensile strength at different days of aging. The results proved the feasibility of using this air entrained concrete with partial replacement of nS and fly ash for structural purposes.

Engineering Presenter: Garcia Sierra, Inti

Mentor: Sundaram, Paul

Title: Tissue Printing of Complex Structures through Micro Extrusion

Authors: Inti Garcia (University of Puerto Rico Mayaguez Campus), Geoffrey Navarro (University of Puerto Rico Mayaguez Campus), Paul Sundaram (University of Puerto Rico Mayaguez Campus), Nanette Diffoot (University of Puerto Rico Mayaguez Campus)

Abstract

3D printing is a method of manufacturing which has been employed to create objects which via conventional methods is complicated or not possible. It is possible to take digital images, such as MRIs, and convert them into a single coordinate map and print with biomaterials such as agarose. The objective of this project is to capacitate a low cost 3D printer to print a mixture of biomaterial and living cells to construct living tissue. This mixture has been carefully selected and developed so that cells can be mixed in safely while in the liquid state and gradually becomes solid at optimal cell growth temperatures for effective printing.

The design makes use of a syringe pump controlled via Arduino to properly coordinate extrusion of cell/agarose mixture relative to axis displacement in space. Over a period of time, a tissue part will be sectioned for histological observation to verify normal growth of tissue. The overall goal of this phase of this project is to create living tissue interspersed in a solid scaffold made of agarose. Through this proof of concept, agarose will be substituted with a biodegradable material such as Alginate. The growth of normal tissue is expected to eventually replace Alginate to engineer a solid tissue construct as a step toward organ printing.

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Engineering Presenter: Gonzalez Lopez, Lorelis

Mentor: Martinez Inesta, Maria

Title: Methane and Carbon Dioxide conversion using Zinc Modified Zeolites

Authors: Lorelis González López (University of Puerto Rico- Mayaguez), Dr. María M. Martínez Inesta (University of Puerto Rico- Mayaguez), Dr. Yomaira Pagán Torres (University of Puerto Rico- Mayaguez)

Abstract

Zeolites are important catalytic materials whose properties can be improved by introducing different cations into their structures. This makes them ideal for producing valuable chemicals from reactants that have a high activation energy. Our goal is to use zinc exchanged zeolites for the production of acetic acid from methane and carbon dioxide. The importance of the zeolites in this process is that they can activate the strong C-H bonds of methane at mild conditions. The three zeolites studied were: zeolites NaX, ZSM-5 and mordenite. To achieve a succesful ion-exchange, three main parameters were controlled: exchange solution concentration, duration and frequency of the exchange, and solution temperature. Due to the sensitivity of the ion-exchange to the acidity of the solution, the pH was monitored throughout the exchange. The resulting samples were characterized with XRD. The analysis showed only small changes in the intensities of the peaks. Although we want to keep the structure as unchanged as possible, it is to be expected that after a long procedure at mildly acidic conditions the structure may suffer some damage. An Inductively Coupled Plasma (ICP) - Elemental Analysis will be performed to verify the insertion of Zn into the zeolite.

Engineering Presenter: Gonzalez Perez, Massiel

Mentor: Calderón Arteaga, Hermes E.

Title: Reuse of Graywater

Authors: Massiel Gonzalez Perez (Caribbean University), Dr. Hermes E. Calderón, Advisor

Abstract

The goal of this project is to design a domestic system that allows toilets to flush graywater instead of clean water, as part of the solution of the drought the island is confronting. The water resources we have are not infinite. Despite the fact that the planet is covered in water (70% of the Earth's surface is 148

water), only 1% of the Earth's water is available as potable and we are wasting it every time we flush our toilets. The project presents the importance of finding solutions to this problem and the impact this design could have if the project is successful. It will include detailed information on the technology available as of today that are related to the solution and a description of the research method applied in the development of this project.

Keywords: Reused Water, Clean Water, Flush Graywater, System Design

Engineering Presenter: Gonzalez Vargas, Jessica M.

Mentor: Medina, Lourdes

Title: An Industrial Engineering Outreach Initiative to Increase Hispanic Participation

Authors: Lourdes A. Medina Aviles (Professor & Mentor), Jessica M. Gonzalez Vargas (Undergraduate Student), Maria Hernandez Cancel (Undergraduate Student), Caroline Lopez Melendez (Undergraduate Student)

Abstract

RealTimePC is an initiative to promote high schools to develop the tools and ability needed to solve today's emerging and most challenging problems through the Industrial Engineering (IE) field. RealTimePC began with a first summer camp in 2013 and has continued throughout the years. Now, this initiative has transitioned into a commotion that includes a RealTimePC Day and Tour. Our purpose is to foment high school students, especially females, to visualize what they are capable to create, learn, and develop through workshops, tours, and summer camps. The summer camp offers a one-week experience of an IE from the vision of an automation process. The workshop offers a one day experience of conferences with Industrial Engineers. At the same time, this workshop impacts their parents with orientations of how to prepare for their children's new journey. At last, the tours are realized to promote the IE field in high schools around Puerto Rico. Through these initiatives we have accomplish for students to have admiration, motivation, extensive knowledge, and encourage their interest for IE. Also, we have successfully implanted in many of them a seed for always do their best, pursue their dreams, break down comfort barriers, and consider IE as a professional career.

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Engineering Presenters: Green Cámara, Miguel Lopez Perez, Brian

Mentor: Salazar, Gerardo

Title: Design, Construction, Troubleshooting & Star-Up Of An Unmanned Aerial Vehicle (UAV)

Authors: Heidy Sosa Martínez, Brian López Pérez, Héctor M. Ríos Nieves

Abstract

Is a fact that future aircraft development is driven by intelligent automated systems, which definitely will lead to profound evolution in airspace technology as actually known. With these challenge on hand we have started the second and third stage of research project by designing & construction of an unmanned aerial vehicle (UAV). The project as a whole is divided in three phases: i. - the completion of the basis of design of an UAV; ii. - model design; iii. - model construction, troubleshooting and start-up. The main objective of this work is to complete an UAV design, construction, troubleshooting and start- up of an UAV capable of takeoff; move to the front, back, left and right; and land. To achieve this mission, we stared from a basis of design previously developed to provide a theoretical revision of terms and concepts that applies to a technology like UAV. The design process will be comprised of detailed plans and specifications. Troubleshooting and Start-Up step will be manage with purpose of detect failures (if any) and correct it until achieve our mission goal, based on research. Also, a constant feedback will be developed to actualize the Basis of Design (BOD) and design itself.

Engineering Presenter: Herrera Monegro, Ronard

Mentor: Saliceti-Piazza, Lorenzo

Title: Ethanol production through the fermentation Saccharomyces cerevisiae using recycled paper as biomass

Authors: Ronard Herrera Monegro (UPR-Mayaguez)

Abstract

The research is focused in using photocopy paper (with and without ink) as a biomass to generate glucose through hydrolysis. it has been proven experimentally that glucose can be obtain from the paper with and without ink in enzymatic conditions (40°C and atmospheric pressure) with cellulase and 150

hemicelulase from different species. Also that the concentration of glucose obtained from the paper depends on the type of paper, the quantity of enzymes and paper used. For this experiment it has been obtained a maximum concentration of glucose of 9.86 g/L and a minimum concentration of 5.45 g/L. In addition, the differences between rate of production for paper with and without ink were almost the same (A difference of 0.10 g/L), which means that ink does not affect the production of glucose. These sugars can be used to obtain bioethanol through yeast fermentation in order to test the viability of using waster paper as an option for the renewable energy industry.

Engineering Presenter: Lopez Marcial, Gabriel R.

Mentor: Diaz-Rivera, Ruben

Title: High-Throughput Single-Cell Electroporation With Geometrically Induced Pulses

Authors: Gabriel R. López Marcial (University of Puerto Rico-Mayaguez), Manuel Dávila (University of Puerto Rico-Mayaguez), Rubén E. Díaz-rivera (University of Puerto Rico- Mayaguez)

Abstract

Electroporation (EP) is a commonly used technique in gene therapy and very recently CRISPR genome editing that consists of applying a high intensity electric field across a biological cell in order to reversibly increase the permeability of the cell membrane. Although common, this technique is associated with certain limitations such as low transfection yield for large groups of cells or being too time consuming to be effective when applied to single cells. In this work, we present a polydimethylsiloxane (PDMS) microfluidic device in which flow-through, single-cell electroporation can be reliably performed for large volumes of cells. The device was fabricated via soft lithography and incorporates a single channel with multiple height and width reductions in series. Voltage is applied across the channel through Ag/Cl electrodes at the inlets and outlets. The cells, pushed through the channel with a syringe pump, create a seal when transiting the geometric reduction, known as the EP zone. This seal forces the current from the applied voltage to go directly through the cell, theoretically electroporating the cell membrane in a reversible manner. We have succeeded in visually and electrically confirming the flow of cells through the geometric constrictions. Electrical recordings of the ionic current through the system agrees well with electrical equivalent models based on the resistance created by a single cell while deformed in the EP zone. We have also collected data for the difference in current drop as the cell passes through multiple constrictions. Future work includes experimental corroboration of single cell electroporation by monitoring the transport of a fluorescent dye (Calcein AM) and the associated electrical recordings in real time.

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Engineering Presenter: Maldonado Martínez, Rubén I.

Mentor: Rodriguez, Hector

Title: Wind Energy Assessment for lighting pole Applications

Authors: Ruben Maldonado (Universidad del Turabo)

Abstract

The aim of this project is to perform a wind energy forecasting for commercially available vertical axis wind turbines in urban light pole applications. The study considers two off-the-shelf wind turbines with rated powers of 200W and 300W and four different types of light bulbs for light pole applications. In particular, the study considered a conventional light bulb of 200W and three LED lightbulbs with 40W, 60W, and 90W, respectively. In the investigation, the power curves for each wind turbine were used in conjunction to actual wind speed measurements at Universidad del Turabo to estimate the energy output. As shown in the results, the 300W machine will be required to energize a 40W LED bulb. The results will be used in the development of a vertical axis wind turbine for the U.S. Department of Energy Collegiate Wind Competition 2016.

Engineering Presenter: Martinez Rosa, Hector D.

Mentor: Perez, Jannette

Title: Development of a Business Plan for an Integrated Light Pole-Wind Turbine System in Puerto Rico

Authors: Hector Martinez (Author), Pedro Rodriguez (Co-Author), Jannette Perez (Mentor)

Abstract

A multidiscipline team, including IE's, through the appropriate market research is working on a new product development to minimize the island energy costs by using green energy. The benefits of this research are the development opportunities in eolic energy considering the substitution of oil as an energy source and replacing with renewable energy. Objectives include the development of a business plan that proposes replacing the current energy source with eolic energy to impact 95% of the public illumination sources in the island. Due to only having 1% of renewable energy used for power generation, there is an area of opportunity in this business venture. A significant development for public 152

illumination could benefit about 1 million users, with savings to the government of approximately $ 100 million annually. The research includes the study of market conditions, such as innovation needs and knowledge of Green Energy focused on eolic sources. The deliverable of this research is presenting a business plan for a small wind turbine public illumination system that is 100% self-sustainable.

All activities within this research follow the methodology of System Engineering, to ensure the process of developing this creative Eco-friendly initiative take into consideration the customer requirements, design specifications, development and implementation activities. Research will explore potential risks involved in all phases of developing the system as well as recommendations to mitigate or minimize these risks.

KeyWords: Energy Management, Business Plan, Engineering Management, Renewable Energy

Engineering Presenter: Martínez Santana, Eliseo

Mentor: Medina, Lourdes

Title: Assessing Triggered Component Interaction Design Complexity from Process Automation Software

Authors: Eliseo Martinez Santana (UPRM), Lourdes Medina (UPRM), Carlos D. Jusino (UPRM), Zachary Soto (UPRM)

Abstract

Technological advances in manufacturing processes have made automation a norm at many industries with increased quality, security and productivity, while decreasing costs from the reduction of human intervention. The implementation of process automation is essential for many industries to stay competitive in countries with higher minimum wages in comparison to other countries. Implementing this technology is complex, with interactions between the structure, electrical connections and software. This research entails the assessment of process automation design complexity from the point of view of the program (software) where component interact. We have called this metric Triggered Component Interaction (TCI) Design Complexity since it is measures physical component interactions that can only be observed through the Process Automation Software. However, implementing this metric is complex itself. Extensive research was done to develop a method that would allow implementing the proposed metric. This works advances the literature on complexity metrics by combining two types of metrics: "component and interactions" with "software" metrics. The literature includes software metrics such as McCabe's Cyclomatic Complexity or Lines of Codes that measure programs volume or size but do not take into account the interactions between components neither how components triggered actions as a group of interacting conditions or independently.

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Engineering Presenter: Martinez Torres, Kenneth J.

Mentor: Perez, Jannette

Title: Evaluation of Occupational Risks in the Operation and Installation of Small Wind Turbines

Authors: Kenneth José Martínez Torres (Turabo University), Prof. Jannette Perez, Ms, Pe (Turabo University)

Abstract

The research reviews the occupational risks within the operation, installation and maintenance/repair stages applicable to a small-scale wind energy system, for a public sector application. One of the objectives of the research is to identify the risk factors associated to the accidents during the lifecycle (this lifecycle comprises the stages previously mentioned) of the system to recommend alternatives that mitigate or minimize these risks. The research includes various reviews of literature for findings in large horizontal wind turbines to serve as baseline for the number and origin of common accidents.

The process of coming up with suggestible alternatives to safely perform the tasks during the lifecycle will consider both human factors and quality management techniques, such as Job Safety Analysis (JSA) and Failure Mode and Effect Analysis (FMEA). The alternatives will suggest on tools, protective equipment, postures and working methods.

The results of the research will assist in designing an appropriate general procedure to assemble, maintain and repair the turbine safely while minimizing ergonomic risks. Once the ergonomic procedures are in place, the workers may securely execute the many tasks involved within the lifecycle of the system.

Engineering Presenter: Masters Arcelay, Amber N.

Mentor: Hwang, Sangchul

Title: Stormwater BMP: Pervious Concrete Pavement and Bamboo Bio-retention

Authors: Amber N. Masters (University of Puerto Rico at Mayaguez) 154

Abstract

Impervious areas in urban environments contribute to the increase in runoff and allows the quicker and increased transport of non-source pollutants such as oil, grease, metals, pathogens, and nutrients. In efforts to control stormwater many detention ponds have been used. Unfortunately, this method has certain disadvantages such as land constraints in small sites and a tendency to attract wildlife, which can be sources of disease-causing bacteria. This study will test the performance of two Best Management Practices (BMP) that better suit an urban environment.

Two optimum mixes of pervious concrete and one impervious mix are tested along with bamboo bio- retention to determine feasibility as a combined system. These systems could then function as a pre- and post- treatment for urban runoff. To test the performance of the three reactors or systems, they are exposed to pollutants and a simulated rainfall.

Results from this short term study demonstrate 40-50% reduction in runoff produced, 33-52% reduction in phosphate and 80-100% in fecal coli (FC) removal run from both BMP's. Bamboo bio-retention alone has proved to be an excellent neutralizer for pH level, even when receiving a variety of influent pH levels. And proved better performance for reducing organic pollution levels with a consistent 60-100% removal with in the first 24 hours.

Overall, the BMP's chosen can replace regular parking areas and sidewalks in urban areas and effectively reduce the volume stormwater drained and increase the quality before stormwater reaches waterways. In fact, the impressive FC removal could potentially lower statistics of pathogens that impair approximately 6,000 miles of Puerto Rico's streams and rivers as of 2014.

Also, optimum mixes used are made with local fly ash which is a waste unless otherwise utilized, making this pervious concrete pavement eco-friendly and cost-effective. While bamboo bio-retention is ideal for the tropical island's climate and has drought-tolerant properties.

Engineering Presenter: Mercado Montijo, Jomary

Mentor: Calcagno, Barbara

Title: Synthesis and Characterization of Liquid Crystalline Elastomer Microactuators

Authors: Jomary Mercado Montijo (University of Puerto Rico Mayaguez, Department of Chemical Engineering), Stephany Herrera Posada (University of Puerto Rico Mayaguez, Department of Chemical Engineering), Barbara O. Calcagno (University of Puerto Rico Mayaguez, Department of General Engineering), Aldo Acevedo (University of Puerto Rico Mayaguez, Department of Chemical Engineering) 155

Abstract

Liquid crystalline elastomers (LCEs) are materials that combine the properties of liquid crystals with polymeric elastomers. LCEsare able to change their optical and mechanical properties and to experience reversible deformationsin response to the application of external stimulus. Due to this characteristic these materials are defined as actuators and are potential candidates for applications in sensing, active substrates, smart devices for microfluidics systems and self-propulsed materials, to name a few.LCEs are commonly synthesized or prepared as macroscopic films of few centimeters, and these systems have been extensively studied and characterized in the literature. Only few works deal with LCEs at the micro scale, and more studies are needed in order to fully understand their behavior, optimize their formulation parameters and expand their applicability range. The synthesis ofLCEs as small microactuators involves the synthesis of liquid crystalline polymers(LCP) in a first stepand the crosslinking of the polymer chains in a second stage after microparticles have been obtained through an O/W emulsion. In this work, the preparation of a nematic side chain LCPthrough a platinum catalyzedhydrosylation reaction where the liquid crystal monomer and the photo-crosslinker 4-(10- undecenyloxy) benzhophenone are attached to the polymeric backbone poly(methylhydrosiloxane), is presented, as well as the preparation of LCE microspheres by emulsion and subsequent crosslinking using UV irradiation. Results of the LCP characterization using different techniques will be discussed including Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Polarized Optical Microscopy (POM). Additionally, the behavior of the microspheres before and after photo-crosslinking studied with POM will also be discussed.

Engineering Presenter: Mercado Montijo, Jonathan

Mentor: Calcagno, Barbara

Title: Composite Liquid Crystalline Elastomers for Sensing Applications

Authors: Jonathan Mercado Montijo (University of Puerto Rico Mayaguez;Department of Mechanical Engineering), Stephany Herrera Posada (University of Puerto Rico Mayaguez;Department of Chemistry Engineering), Barbara O. Calcagno (University of Puerto Rico Mayaguez;Department of General Engineering), Aldo Acevedo (University of Puerto Rico Mayaguez;Department of Chemistry Engineering)

Abstract

Liquid crystalline Elastomers (LCEs) are structurally anisotropic materials capable of changing their physical and mechanical properties when exposed to external stimuli e.g. temperature changes. These smart materials have advantageous number of functionalities; some of them are sensing, mechanical actuation, self-propelled systems, small motors, active substrates, and also bioengineering tissue replacements to name a few. The presence of magnetic particles, Oleic Acid Coated Iron Oxide 156

Nanoparticles, enables triggering in a controlled and contactless way reversible deformations in these materials through the application of alternating magnetic fields. As such, characterization of LCEs under static and dynamic loadings before and after incorporation of magnetic nanoparticles is crucial in order to render them suitable for multiple applications. In this work, the evaluation of LCEs mechanical transient behavior at different stress levels using an Instron ElectroPulse model E3000 is presented as well as the evaluation of their mechanical properties such as the Young's moduli, Ultimate Tensile Strength, toughness, and average life cycle, and how they are affected by the presence of magnetic particles.

Engineering Presenter: Millet, Alexander

Mentor: Suleiman, David

Title: Density Functional Theory Studies of Hydrogen Bonding Interactions Between Water Clusters and Sulfonated PEEK Polymers

Authors: Alexander Millet Ayala (University of Puerto Rico, Mayagüez campus), Paul Meza Morales (University of Puerto Rico, Mayagüez campus), David Suleiman Rosado (University of Puerto Rico, Mayagüez campus)

Abstract

Sulfonated Polyether ether ketone (PEEK) membranes have been studied over the past 15 years due to their potential as proton exchange membranes (PEM) for fuel cell or specialty separation applications. Their capacity to be sulfonated and the presence of ether groups in their backbone could create synergistic effects for the transport of protons that could potentially be superior to the state of the art Nafion membranes. The interactions between the sulfonated PEEK sulfonic group and water clusters affect the morphology of the membrane, forming ion exchange channels that facilitate the transport of protons. These mechanisms are currently not well understood, and computational simulations can aid advancing the knowledge of these interactions. Density functional theory (DFT) calculations can be used to predict the orientations and positions of molecules in their characteristic electronic environment, and we can obtain an insight of the influence of water in the transport properties of sulfonated PEEK polymer membranes. Four functional/basis set combination calculations were conducted and compared with state of the art CCSD calculations using Gaussian09B to determine the most accurate weak bond descriptor. For this, the criterion considered was an interaction energy calculation of 2 and 3 water molecules that interacted with themselves in a hydrogen-bonding environment An accurate description was achieved with a wB97XD/aug-cc-pvtz combination, which out-performed the commonly used in literature B3LYP/6311++G(d,p) combination. Using this result, next efforts will be focused in simulating a more accurate electronic environment of sulfonated PEEK copolymers with 1 and 2 water molecules interacting around the sulfonic groups. Experimental validation of the simulations is also being planned 157

out with membrane casted sulfonated PEEK samples, and FT-IR analysis of the dry and lowly hydrated membranes.

Engineering Presenter: Moreno Hernandez, Amanda D.

Mentor: Torres-Garcia, Wandaliz

Title: Identification of Transcriptomic Patterns for Endometriosis Characterization using Random Forest Models

Authors: Amanda D. Moreno Hernandez (University of Puerto Rico, Mayaguez Campus)

Abstract

Ten percent of women worldwide have endometriosis which is a disease that yields higher risk of infertility and cancer. Methods used to diagnose endometriosis are mostly invasive despite efforts and biotechnology growth knowledge in this condition. In average it takes 7.5 years from onset of symptoms to get a diagnosis. Improvement of diagnosis may be achieved through molecular characterization. We aim to build an ensemble classification model using transcriptomic data to distinguish patients with and without endometriosis and through this model identify relevant molecular patterns. We gathered the gene expression profiles of 127 genes from 47 patient samples available at the Gene Expression Omnibus database. These were used to classify endometriosis versus normal (control) samples using a data mining approach. Samples were evaluated using random forest in two separate expression platforms measuring accuracy, error rates and partial variable contribution. The variation of across the different platforms was evaluated finding slight differences among them. Depending on the platform used the ranking of important genes was different exposing the need to separate this variation source. Furthermore, the random forest model constructed for each platform provided high accuracy metrics (~95%) and revealed important genes such as FOXC1 and GDF11. Partial Variable Contribution showed FOXC1 overexpressed and GDF11 downregulated for patient samples with endometriosis. These two genes have been found to affect endometrial cancer and endometriosis in limited literature work. Hence, these results show the potential of gene expression contribution to a better understanding of endometriosis and supply new diagnostic method.

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Engineering Presenter: Orraca Rosario, Lian

Mentor: Leon, Leyda

Title: Radar Location Survey and Clutter Blockage Analysis for Radar Networks Covering Puerto Rico

Authors: Lian R. Orraca Rosario (UPR-Mayaguez), Leyda V. León Colón, Ph.d. (UPR-Mayaguez)

Abstract

This project optimizes current algorithms that analyze radar beam clutter blockage in order to obtain elevation angle and tower height for minimum blockage. These algorithms detect blockage caused by the geographical location of the radar. Therefore the visible blockage of the algorithms output accounts for mostly mountains around the radar. It is expected to use these algorithms to identify new locations for the OTG X-band weather radars in order to properly install them. UPR Carolina and UPRRP were two locations targeted in the research. After analyzing the results of the algorithms and obtaining the proper locations and height the results are recorded in the Puerto Rico Weather Radar Network servers. Students in these universities, interested in installing the Puerto Rico Weather Radar Network OTG X- band radars will be handed the results in order to assist them on the correct placement and installation of the radars; while expanding a low cost and high resolution weather radar network in Puerto Rico. The expansion of a high resolution radar network is necessary in order to gather better and more precise data of weather in the tropic.

Engineering Presenter: Ortiz Mercado, Danabet X

Mentor: Medina, Lourdes

Title: How Stakeholders Contribute to Medical Device Decisions? A Conceptual Framework.

Authors: Jessica M. Gonzalez Vargas (Undergraduate Research, UPRM), Marivette Rullan Semidey (Undergraduate Research, UPRM), Danabet X. Ortiz Mercado (Undergraduate Research, UPRM), Alondra M. Ortiz Ortiz (Undergraduate Research, UPRM), Lourdes A. Medina Aviles (Professor & Mentor, UPRM)

Abstract

Medical devices represent the majority of the expenses that patients and insurance companies incur. The entities involved in the decision making process of selecting the criteria used in a medical device 159

are: doctors, hospital administrators, distributors, manufacturers, and ultimately patients. These stakeholders present barriers of integration and lack of a standardized process in the medical device supply chain. Our hypothesis is that the criteria used by each of the stakeholders is different from one to the other. This situation makes us wonder to urgency research for a standardized process to ensure the safety, satisfaction, and needs of the patient. In order to find the criteria used by stakeholders in the decision making process, various scientific articles were revised, and a conceptual framework was developed to summarize the obtained data. The results found in the literature review are summarized in four principal categories: Patient Safety, Physician Preference Items (PPIs), Quality, and Financial, which were subdivided for enhanced understanding. This framework will be used to interview medical device manufacturers, distributors, hospital administrators, physicians, and patients with the purpose of making the selection of a medical device a standardized process.

Engineering Presenter: Ortiz Ortiz, Alondra Michelle

Mentor: Medina, Lourdes

Title: User-centered Design of Medical Devices: Patients' Needs and Decision Makers Criteria

Authors: Alondra M. Ortiz (University of Puerto Rico at Mayaguez), David Claudio (Montana State University), Lourdes A. Medina (University of Puerto Rico at Mayaguez), Luisa V. Niño (Montana State University), Marlyn Santana (University of Puerto Rico at Mayaguez)

Abstract

Designing an efficient global supply chain is part of the organization's transformation process for expanding its markets. An efficient supply chain is distinguished by the integration of all the entities involved in the development process of medical devices: manufacturers, distributors, providers and patients. However, literature shows that healthcare supply chain is not well connected between customers (hospital administrators and physicians) and manufacturers and that patients are rarely seen as being able to provide valuable input into the development process.

This research focuses on two projects that have a user-centered design approach to understand patients' needs and explores the criteria decision makers use across the supply chain. These projects are: (1) Evaluating Chronic Pain Management: the Needs for Medical Devices; and (2) A Multiple Stakeholder Analysis of the Decision Making Criteria for Medical Devices. The first project focuses in understanding the clinical needs of a medical device used as a treatment of chronic pain diseases. This device is called a neuroestimulator and provides pain relief by blocking pain messages that the nervous system send to the brain. With a survey to be completed by patients of chronic pain conditions we expect to find the variables that patients consider important at the moment of selecting a specific medical device. With this information the manufacturers can understand what they need to take into account at the moment of designing a medical device to meet patient's needs and expectations. 160

The second project has the objective of defining the criteria that is taken into account by all the stakeholders at the moment of selecting a medical device. We also expect to find the level of participation of patients in this process. To accomplish this, two surveys were designed and distributed between all the entities involved in the decision-making process.

The main objective of this research is to produce a standardized method for the selection of medical devices, which includes the participation of the patients. We need to educate all the entities involved in the supply chain of medical devices regarding the importance of including the patients in the design, development, and decision-making processes of medical devices.

Engineering Presenter: Perez De Jesus, Carlos E.

Mentor: Cordova-Figueroa, Ubaldo M.

Title: Polymer dynamics in active Brownian particle suspensions - A Brownian dynamics study

Authors: Carlos E. Perez-de Jesus (UPR-MAYAGUEZ), Mir Karim (UPR-MAYAGUEZ), Ubaldo M. Cordova-figueroa (UPR-MAYAGUEZ)

Abstract

Biopolymers, such as motor proteins, have interesting dynamics that occur in bacteria due to ATP driven processes which include activity in the medium. This non-equilibrium phenomenon is fundamentally different from the realm of equilibrium statistical thermodynamics. The chain-like conformations and length-scale dependent dynamics of biopolymers give rise to complex structural and dynamical occurrences even in thermally equilibrium cases. So it is of interest to understand these phenomena in non-equilibrium conditions. Prior studies in this field considered active components as a continuum and showed their effects on enhanced polymer dynamics. In this study, we address similar problem numerically by considering active component and polymer entity explicitly. To do so, we represent polymers as bead-spring chains and active components as active Brownian particles (ABP) in our Brownian dynamics (BD) simulations. Our key objectives are to find out the resultant change in polymer dynamics in presence of ABPs and the effect of flexible confinements – long polymers – on ABP dynamics. The outcomes of this work may elucidate the fundamental dynamics and physics of intracellular organelle transport, motions of bacteria inside human gastronomical tract etc.

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Engineering Presenter: Quiñones Colón, Beatriz A.

Mentor: Almodovar, Jorge

Title: Polysaccharide-based polyelectrolyte multilayers: Physicochemical characterization and in vitro studies

Authors: Beatriz A. Quiñones Colón (University of Puerto Rico - Mayaguez Campus), David A. Castilla Casadiego (University of Puerto Rico - Mayaguez Campus), Jorge Almodovar Montañez (University of Puerto Rico - Mayaguez Campus)

Abstract

Implants over the years have caused many unpleasant reactions and infections. This occurs because the body rejects them after a period of time since they are not biocompatible. One alternative to improve their biocompatibility is to generate a bioactive surface that helps in cell processes such as cell adhesion and therefore improves biocompatibility. Our work was composed of developing three and six bilayers of Chitosan (Chi) and Heparin (Hep) over a silicon substrate using the layer-by-layer (LBL) method, simulating the surface of the tissue's extracellular matrix to enhance the biocompatibility and cellular adhesion of the substrate. NIH/3T3 cells were used for in vitro studies. Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE) allowed us to study the thickness and chemistry of the CHI/HEP bilayers, while cellular adhesion and morphology was observed via scanning electron microscopy (SEM). The IR-VASE analysis reported the distinctive peaks of polysaccharides, enabling us to see their chemistry and presence in the substrate. SEM demonstrated that three bilayers were not able to completely cover the silicon surface while six bilayers were able to cover completely the silicon substrate and generate a homogenous surface. Our in vitro studies reported that six bilayers generate an attractive surface for cells to adhere and survive in comparison to the three bilayers. This demonstrates that the development of these polymeric bilayers can become a promising way to increase the biocompatibility of biomaterials' surfaces.

Key words: layer-by-layer, biocompatibility, polysaccharides, biomaterials

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Engineering Presenters: Ramirez Nazario, Catalina M Castro Cortes, Alfer I.

Mentor: Suarez, Oscar Marcelo

Title: Synthesis of Aluminum Multiwalled Carbon Nanotubes by Mechanical Alloying and Sintering

Authors: Catalina Ramírez (Undergraduate Students of University of Puerto Rico at Mayagüez), Alfer Castro (Undergraduate Students of University of Puerto Rico at Mayagüez), Héctor Colón (Undergraduate Students of University of Puerto Rico at Mayagüez), Johnny López (Undergraduate Students of University of Puerto Rico at Mayagüez), Catherine Castro (Undergraduate Students of University of Puerto Rico at Mayagüez), Oscar Marcelo Suárez (Professor of University of Puerto Rico at Mayagüez)

Abstract

Aluminum matrix composites are widely used in applications demanding high strength and high density materials. The approach in this research is to study the strengthening of a pure aluminum matrix by the addition of multiwalled carbon nanotubes (MWCNTs). The synthesis of the composite was based on a – COOH ligand as a functionalizing agent of the MWCNTs, which were dissolved in isopropanol as solvent media. This was followed by mechanically alloying the MWCNTs with the aluminum matrix via high- energy ball milling. The resulting composite was then compressed into pellets and sintered at 500ºC. It was then compared to pure aluminum based on thermal and mechanical properties. The experimental results revealed higher hardness and wear resistance than pure aluminum, as measured on the track left on the specimens by a pin-on-disk apparatus. Thus, this provides a simple and cost effective fabrication methodology to prepare an aluminum matrix for applications were high thermal conductivity and high mechanical strength are required.

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Engineering Presenter: Ramos Sepúlveda, María E.

Mentor: Suarez, Oscar Marcelo

Title: Study of high-strength concrete reinforced with bamboo fibers.

Authors: María Elisa Ramos Sepúlveda (University of Puerto Rico, Civil Engineering), Raúl Marrero Rosa (University of Puerto Rico, Civil Engineering), Fernando Benítez Ortíz (University of Puerto Rico, Civil Engineering), Hildélix Soto Toro (University of Puerto Rico, Civil Engineering), Oscar Marcelo Suarez (University of Puerto Rico, General Engineering)

Abstract

Cement is the most common material used for construction and the responsible of approximately 5% of carbon emissions on the atmosphere. To assist in the amelioration of this problem in our research bamboo is used a constituent of concrete mix. This mix includes fly ash (FA) and nanostructured silica (nS), materials use for reducing the amount of cement to attain high strength building materials. Guadua angustifolia bamboo is abundant, economical, fast growing, lighter and their fibers have a high modulus of elasticity equivalent to soft metals. Five different designs were produced with different proportions of the constituents of the mix. Tensile and compressive strengths were assessed. Bamboo-containing mixes showed increases in compressive and tensile strength approximately in 22% and 17%, respectively, compared to unreinforced concrete. The research led to a better understanding of the natural fibers and cementitious interactions. The results will open the path to new ideas for a more eco- friendly concrete production.

Engineering Presenter: Rivera González, Ivonnemary

Mentor: Perales-Perez, Oscar

Title: Ti-doped ZnO Nanoparticles as Novel Direct Generator of Singlet Oxygen for Photodynamic Therapy.

Authors: Milton Martinez Julca (University of Puerto Rico, Mayaguez), Oscar Perales Pérez (University of Puerto Rico, Mayaguez), Sonia Bailón (University of Puerto Rico, Ponce), Melina Pérez (University of Puerto Rico, Mayaguez) 164

Abstract

Photodynamic therapy (PDT) is an alternative to traditional cancer treatments. This approach involves the use of photosensitizing (PS) agents and their interaction with light. As consequence, cytotoxic reactive oxygen species (ROS) are generated that, in turn will destroy tumors . On the other hand, ZnO is a biocompatible, nontoxic, and biodegradable material with the capability to generate ROS, specifically singlet oxygen (SO), which makes this material a promising candidate for 2-photon PDT. Doping ZnO with Ti species is expected to induce the formation of oxygen vacancies in the host oxide structure that should affect the electronic transitions related to the generation of SO. The present work reports the effect of the level of Ti-doping on the structure and capability to generate SO. Ti-doped ZnO nanoparticles were synthesized under size-controlled conditions using a modified version of the polyol route. The structural and optical properties of these nanostructures were studied by X-Ray diffraction (XRD), FTIR spectroscopy (IR), Photoluminescence spectroscopy (PL) and UV-Vis spectroscopy (UV-Vis ). XRD measurements confirmed the development of well-crystallized ZnO Wurtzite; the average crystallite sizes ranged between 11.7 and 14.2 nm, with an increase in Ti content. The corresponding band gap energy values, estimated from UV-vis measurements, decreased from 3.32 to 3.29 eV. PL measurements of Ti-ZnO revealed the presence of emission peaks centered on 361, 390, and 556 nm; these emisiion peaks correspond to the exciton emission, transition of shallow donor levels near of the conduction band to valence band, and oxygen vacancies, respectively . The observed decrease of the emission intensity in the 556 nm broad peak was attributed to the reduction of the defects (vacancies) due to the incorporation of dopant species into the host oxide lattice. The fact that Ti-doped ZnO nanoparticles produce high levels of SO species when compared to pure ZnO, enable this nanomaterial as a potential direct PS agent for cancer treatment by PDT . Forthcoming efforts will be focused on the analysis of the correlation between type and concentration of structural defects with the yield of SO generation in presence of Ti and other dopants (e.g. Li+)

Engineering Presenter: Rodriguez Calero, Ilka

Mentor: Medina, Lourdes

Title: Decision Support for the Product Development Process of Medical Devices

Authors: Lourdes Medina (University of Puerto Rico - Mayagüez), Ilka Rodriguez-calero (University of Puerto Rico - Mayagüez)

Abstract

Several sources in literature concur in saying, the medical device development process is an interdisciplinary field that combines elements of research, engineering, regulations, marketing, and business. Strict standards and regulations, combined with design controls specific to medical devices, results in a complex product design process. In order to alleviate the design process, a comprehensive 165

model that encompasses the entire product design and development process for medical devices has been developed. In such model, a complete view of all the steps and elements relevant to different stages of the medical device development process is captured. The framework of this research is based in the realization that the model could be improved to add usability to it by working as a decision support tool for medical device development using a web platform as the user interface. This tool will serve as a logical, reliable decision support system to aid all the stakeholders involved in the development of a new-to-the-world medical device. With this in mind, the tool points at new ventures and individuals who seek to understand and address the complexities of designing a medical device.

Engineering Presenter: Roman Sang, Suilan

Mentor: Gonzalez-Sanchez, Juan

Title: Design of a Magnetic Field Assisted Electrospinning by using a MakerBot 3D Printer

Authors: Dr. Juan Gonzalez Sanchez (UPR Bayamon), Suilan Roman Sang (UPR Bayamon), Fernando Vargas Jimenez (UPR Bayamon), Hector Perez Rosario (UPR Bayamon)

Abstract

This study will present the design process of a Magnetic Field Assisted Electrospinning (MFAES) setup by using a MakerBot 3-D Printer and AutoCAD 2015. The material used to create the parts was Acrylonitrile Butadiene Styrene (ABS) plastic rolls. We added to our setup a design a Van de Graaff generator in order to obtain the high voltage necessary to obtain the electrospinning process. We will show in details the design blueprints and renders of our components. Also, we developed different mask shapes for sputtering to create contacts and developed different UV sensors.

Engineering Presenter: Roque Gonzalez, Shamarie

Mentor: Goenaga-Jimenez, Miguel

Title: Synthesized Nanostructures Photocells

Authors: Shamarie Roque Gonzalez (Turabo University), Abrahan Garcia Cintron (Turabo Univeesity) 166

Abstract

Engineering Presenters: Sanchez Rodriguez, Lianne Martínez Reyes, Karina N.

Mentor: Santiago, Nayda

Title: The Tech. Carnival: An Outreach Program for Creating Awareness of STEM Fields in Public High School Students

Authors: Lianne Sanchez Rodriguez (UPRM), Karina Martinez (UPRM)

Abstract

Less students from public high schools are considering higher education careers within STEM fields as an option in comparison with those of private schools. Research has found that one of the causes for this is the low levels of exposure to these areas that public school students receive due to budget insufficiency. The aim of this research project is to expose these students to the electrical and computer engineering 167

fields, without it being too expensive for the schools and students. In order to do this a workshop based outreach program has been developed. This outreach program consists of the creation of fun and interactive game modules assembled by using recycled material, dynamic hardware and software components. By using these modules the students will learn the basics of electrical and computer engineering. Additionally, supporting materials, such as teaching manuals and lesson plans for teachers, and instructional booklets for students will be paired with the series of workshops to aid in the development of these modules. A webpage is being designed to provide additional material such as videos and useful documentation for the modules. Each instructional booklet will give detailed instructions on how to build the modules, while the theory of hardware and software will be discussed in the teacher's guide so that it can be taught in the workshops after school hours. Ultimately, the vision of this research is to provide student with the knowledge of what is engineering and demonstrate to them that a career in STEM fields is well within their reach.

Engineering Presenter: Sepulveda Ramos, Nelson E.

Mentor: Suarez, Oscar Marcelo

Title: Study of the Electrical Properties of Bio-Ferroelectric Composite Containing STO Nanoparticles

Authors: Nelson Seplúveda-ramos (Electrical Engineering), Amarilis Declet (Mechanical Engineering), Javier Martínez (Mechanical Engineering)

Abstract

Scientists have focused on studying bio-ferroelectric composites to develop new environmentally friendly and inexpensive electronic elements such as capacitors, actuators and transistors. In the present research, bio-ferroelectric nanocomposites were prepared with a matrix composed of chitosan- cellulose, which was reinforced with strontium titanate (STO) nanoparticles. In this study some of the composite characteristics evaluated were the effect of the cellulose concentration in the matrix at different amounts of STO nanoparticles. To fabricate the bio-ferroelectric composites, a chitosan- cellulose layer was synthesized followed by a layer containing the ferroelectric nanoparticles. These composites underwent electrical tests to determine their dielectric constant, current density and conductivity. The results revealed that the addition of nanoparticles raised the dielectric constant and lowered the current density and the conductivity of the bio-ferroelectric nanocomposites. The highest value of the dielectric constant obtained was 505.83 for the composite containing 15 v% cellulose and 20 wt% at 1 KHz frequency. The dielectric strength test, using a "step by step" method, was performed by varying the voltage from zero to 60 V. At this value the samples have not reached their breakdown voltage. It is believed that this biopolymer-based composites reinforced with STO ferroelectric 168

nanoparticles have promising characteristics suitable for radio frequency and microwave applications in which high electrical tunability and flexible dielectric waveguide are required.

Engineering Presenter: Serrano Carrasquillo, Marizabeth

Mentor: Romero, Edwar

Title: Wind Tunnel Design

Authors: Marizabeth Serrano ((Turabo University)), Edwar Romero (PE (Turabo University))

Abstract

It's necessary to make sure that this invention work for what its designed or witch problem might came on the creation behind the number and the simulation of the drawings. Therefore the idea of this low speed wind tunnel was to create a tool that will help the Juracán Energy Team to test their wind turbine. In order to achieve this the wind tunnel should have a cross sectional testing area of at least 20 in x 20 in with a range of velocity of 0 – 20 m/s (45 mph). But this taking in consideration the available space and budget of the university. To accomplish these necessities some of the initial requirements were compromise after several designs, investigation and simulations the best option for this purpose shows to be a basic wind tunnel made with the idea that in the future this one can and will be modified to be a multi used wind tunnel for different kinds of research such as, fluid dynamics, aerospace, aerodynamics, and even structural testing. With an 24 in x 24 in cross sectional testing area an simple fan this wind tunnel arrives only to 13 m/s (29 mph) witch its enough to test this wind turbine.

Engineering Presenters: Torres, Saul Osorio Chevere, Cidmarie

Mentor: Salazar, Gerardo

Title: Basis Of Design For An Unmanned Aerial Vehicle

Authors: Cidmarie Osorio Chevere, Roberto Golderos, Suzette Rojas Viera 169

Abstract

Nowadays the big picture of future aircraft development is driven by intelligent automated systems. This might lead to a paradigm change in aircraft design and it will definitely lead to profound evolution in airspace operation. Due to these constant movements in aviation we have started the beginning stage of research by developing the base of design of an Unmanned Aerial Vehicle (UAV). The project as a whole is divided in three phases: i. - the completion of the basis of design towards the successful development of an UAV; ii. - model design; iii. - is model construction, troubleshooting and start-up. The main objective of this work is to complete the first stage, which is to create a basis of design capable of providing sufficient information to guide the next two stages to final goal: a UAV that flies and is able to carry out assigned missions. The first step to achieve the target was to develop a theoretical revision of terms and concepts that applies to a technology like UAV. Then, it was completed a research of commercially available components. The idea was to compile a manufacturer part list and a reference of how it can be implemented to design, build and operate a UAV (e.g. airframe material, electrical and fossil powered engines, control systems, and others). Finally, four (4) proposed layout models were developed and proposed, as a starting point of design stage. Those can be modified further ahead of the program to obtain a final detailed design. In addition, all of them have initial design recommendations and general specifications to be followed for next design-construction team.

Engineering Presenter: Vazquez, Mairym

Mentor: Calderón Arteaga, Hermes E.

Title: Failure Analysis of Matrix/Reinforcement interface by FEA

Authors: Mairym Vazquez (Caribbean University) , Dr. Hermes E. Calderón, Advisor

Abstract

Mg-AlB2 interaction in Al-Cu-Mg matrix reinforced with AlB2 particles was reported for the first time [1]. It was assumed this interaction was responsible for a weakening of the reinforced matrix on the vicinity of particles. The goal of this research is to employ the Finite Element Analysis (FEA) method to model the composite failure considering the drop of strength in the matrix and identify if this interaction was the responsible for specific fracture characteristics of the matrix/reinforcement interface. SAP2000 software will be used to model the matrix with the Mg-AlB2 interaction and the reinforcement particle. The material properties will be feed to the program while tension conditions will be studied.

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[1] Calderón, H. E., Hidalgo, R. G., Melgarejo, Z. H., & Suárez, O. M. (2010). Effect of AlB 2–Mg interaction on the mechanical properties of Al-based composites. Materials Science and Engineering: A, 527(9), 2258-2264.

Engineering Presenters: Vazquez Ramos, Leida M. Rodríguez Nieto, Tarymar

Mentor: Cardona Martinez, Nelson

Title: Solvent Effects in the Catalytic Conversion of Fructose to Lactic Acid

Authors: Christian G. Rivera-goyco (University of Puerto Rico at Mayaguez), Nitza Padilla-fuentes (University of Puerto Rico at Mayaguez), Michelle Marrero-vázquez (University of Puerto Rico at Mayaguez), Yomaira J. Pagán-torres (University of Puerto Rico at Mayaguez), Nelson Cardona-martínez (University of Puerto Rico at Mayaguez)

Abstract

Lactic acid is an industrial bulk chemical with production higher than 300,000 metric tons per year in 2010. Due to its high versatility and importance as a platform chemical it is forecasted that its market demand will increase in the following years. Current lactic acid production from fermentation routes will not be able to satisfy the forecasted demand due to technical challenges such as high side production of salts as by products and slow production rate. In this work we demonstrate that the combination of a Sn-Beta zeolite with mainly Lewis acidity prepared using a post-synthetic procedure and a solution of GVL and water as solvent is an effective catalytic process for the production of lactic acid from fructose. Highly crystalline Sn-Beta zeolite catalyst was synthesized with a surface area of 536 m2 g-1 and a weight percentage composition of 0.131% Al, 0.907% Sn, and 41.4% Si (Si:Sn 193). The results indicate that when the reaction is conducted, using Sn-Beta, in GVL:H2O there is an almost three-fold increase in the initial fructose conversion rate and a four-fold increase in the production rate of lactic acid when compared against using only water as a solvent. Therefore the use of Sn-Beta zeolite prepared using a post-synthetic procedure amenable to scale up and GVL:water as solvent offers a viable pathway for the conversion of fructose to the commodity chemical lactic acid in high yields.

Engineering Presenter: Villalongo Andino, Germara 171

Mentor: Pagan Torres, Yomaira

Title: Hydrogenation of Carbon Dioxide (CO2) to Fuels and Chemicals over Metal-supported Catalysts

Authors: Germara L. Villalongo-andino (University of Puerto Rico - Mayaguez (UPRM)), Wella Vidal-urquiza (University of Puerto Rico - Mayaguez (UPRM)), Yomaira Pagan-torres (University of Puerto Rico - Mayaguez (UPRM))

Abstract

Carbon dioxide (CO2) conversion has presented a challenge throughout the years due to its molecular stability and low efficacy of the catalysts developed to date. CO2 is being explored as a sustainable source for the production of some of the world's largest commodity chemicals, such as methanol. This research focused on the optimization of bimetallic copper-gallium (Cu-Ga) catalysts for the production of methanol through unique structural and chemical properties. Different variables were studied for the optimization of catalytic activity and determination of optimal reaction parameters and the catalysts were studied by means of Transmission Electron Microscopy (TEM) and DFT calculations. Based on theoretical and experimental comparisons, Cu-Ga catalysts exhibited increased CO2 conversion and selectivity towards the production of methanol in reference to other bimetallic catalysts. The presence of gallium enhanced catalytic stability and reduced aggregation, increasing availability of active sites for the reaction. Future work consists on gaining deeper understanding of reaction pathways, along with further characterization and understanding of catalysts and their development. This research project could enable a greater conversion efficiency of carbon dioxide, addressing one of the biggest challenges of the millennium, and lead to the production of one of the world's largest commodity chemicals from a sustainable carbon source that the planet urgently needs to reduce.

Engineering Presenter: Weintraub De Jesus, Karen L.

Mentor: Martinez Inesta, Maria

Title: Methane and Carbon Dioxide conversion using Zinc Modified Zeolites

Authors: Karen Weintraub De Jesus (University of Puerto Rico - Mayagüez), Dr. Maria Martinez Inesta (University of Puerto Rico - Mayagüez), Dr. Maria Curet-arana (University of Puerto Rico - Mayagüez), Brian Montejo Valencia (University of Puerto Rico - Mayagüez)

Abstract

Producing acetic acid through the conversion of carbon dioxide and methane can result as an economical and environmental advantage. The project aims to design a sustainable catalytic system for 172

the direct production of acetic acid (CH3COOH) from CO2 and CH4. We hypothesize that different coordination environments of metals in Faujasite (FAU) zeolite as well as different aluminum coordination will affect both the methane activation and the formation of Brønsted acid sites that facilitate C-C bond scission that are necessary to produce acetic acid. This semester the computation methodology applied was the density functional theory (DFT) using wB97XD and M06L functionals. Validation of functionals were done through reaction energy calculation for the production of acetic acid. To further validate the chosen method, the resulting vibrational modes were compared to reported values. To determine possible intermediates of the activation of methane in an ion exchanged Zn-FAU, reaction energy calculation were executed with different configurations. It was determined wB97XD functional that best described the system studied. Reaction calculations showed the instability of the studied methane intermediates within the framework. To continue to determine the possibility of a lower reaction energy, future work will consist of introducing carbon dioxide to the model to observe its interaction with the methane and the zeolite.

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Environmental Sciences

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Environmental Science Presenter: Álamo Rodríguez, Kenya F.

Mentor: Perez-Jimenez, Jose R.

Title: Colonization Factors among Hexadecane-Degrading Bacteria for Efficient Soil Remediation

Authors: Kenya F. Álamo Rodríguez (Universidad del Turabo), Yomarie Bernier-casillas (Universidad del Turabo), José R. Pérez-jiménez (Universidad del Turabo)

Abstract

Rhizoremediation has improved by efficient combination, based on colonization factors, of plants and microbes to reduce the harm of pollutants in nature. Bacterial contribution to alkane degradation was documented for polluted and temperate sites. Which colonization factors are harbored in hexadecane- degrading bacteria for efficient soil rhizoremediation? We hypothesized that if we stimulate specific strains naturally selected in soil then plant development will be enhanced and remediation will take place. The objective is to evaluate which strains of hexadecane-degrading bacteria (HDB) promote plant development in the presence of hexadecane. Soil samples, collected at Caño Martín Peña, were inoculated, as consortium, on rich media. HDB were isolated by aerobic cultivation on mineral media supplemented with hexadecane as sole carbon source and subjected to 16S rDNA sequencing. Colonization factors were evaluated among isolates, such as polyhydroxyalkanoates (PHA) production and resilience test that are advantageous for plant development. Results have demonstrated ten strains capable of producing PHA, important in the production of bioplastics and rhizosphere survival. All prospects have been able to grow in a 1% hexadecane concentration. Colonization factors tests revealed diverse capabilities among fifty-eight strains: phosphate solubilization (7%), production of indole acetic acid (3%), ammonia (17%), protease (34%), and siderophore (4%). Among fifty-eight strains, twenty strains harbors most of the colonization factors and includes members of the genus Klebsiella and Pseudomonas. HDB prevails across Neotropical ecosystems, despite pollution level, are phylogenetically diverse, and harbors novel genetic variants. These alkane-degrading bacteria provide novel isolates to deal with pollution and disclose processes in nature.

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Environmental Science Presenter: Aponte Marcano, Patria

Mentor: Roberson, Loretta

Title: Growth ratio and Symbiodinium density of Porites astreoides juvenile.

Authors: Patria Aponte Marcano (University of Puerto Rico Rio Piedras Campus), Neidibel Martinez (University of Puerto Rico Rio Piedras Campus), Loretta Roberson (University of Puerto Rico Rio Piedras Campus)

Abstract

Coral reefs are ecologically and economically important ecosystems that sustain twenty five percent of marine life and also provide us food, medicine and coastal protection. To grow and develop in their environment, corals perform a process whereby they deposit calcium carbonate (Ca?CO?_3), called calcification. If this process is affected, the coral population too. Changes in coral population are set by comparing growth, recovery and calcification rates with bleaching and mortality rates. One reason why corals die from a stressor is because of the losing of their Symbiodinium algae that reside in symbiosis with the coral host providing it with nutrients. The algae perform photosynthesis to produce oxygen and sugars, which are used by the polyps, and feed on coral catabolites. The purpose of this study is to describe the growth ratio and the Symbiodinium abundance in the Caribbean coral Porites astreoides juvenile. In this experiment, Porites astreoides larvae were maintained in a controlled aquarium-based study. The polyps were photographed and analyzed one time week, to determine Symbiodinium abundance and coral calcification ratio. Polyps height data were collected by analizing 3D pictures in NIS Elements computer program and the Symbiodinium abundance was measured with Image J-Fiji software.

Environmental Science Presenter: Arroyo, Axel

Mentor: Morell, Geraldo

Title: Carbon-based Nanomaterial as an alternative disinfectant agent for Water Treatment Plants

Authors: Axel Arroyo (Department of Chemistry, University of Puerto Rico), Abelardo Colón (Department of Environmental Science, University of Puerto Rico), Javier Avalos (Department of Physics, University of Puerto Rico), Gerardo Morell (Department of Physics, University of Puerto Rico,), Rafael Rios (Department of Environmental Science, 177

University of Puerto Rico), Brad R. Weiner (Department of Chemistry, University of Puerto Rico)

Abstract

Current US water treatment plants use chlorine to disinfect water, but improper management of this hazardous gas can cause lethal effects on water plant workers. Furthermore, disinfection by products (DBP's) produced by the chlorine disinfection process has raised health concerns because they can cause cancer to the population that drinks the water. Ultra-Disperse Nano diamond (UDD), is an interesting carbon allotrope since it has a small particle size (4-5 nm) and have great biocompatibility properties. These properties make this material an interesting one for anti-bacterial/anti-viral treatments. We have carried out studies of UDD as a bactericidal agent as an alternative disinfection process for water treatment plants. We mixed different concentration of UDD powder with river water from an urban watershed to determine the effectiveness of UDD as a biocompatible reusable water treatment agent. We cleaned the UDD by thermal method and tested again for disinfection properties after usage. TEM, EDS & FTIR where done for UDD surface characterization, bacteria sampling, qualitative (normal imaging) and quantitative data (statistical analysis) were done for UDD bactericidal properties characterization. TEM results showed UDD from 4-10 nm size; EDS and FTIR showed no change in UDD surface composition and molecular structure. Bacteria sampling results showed strong bactericidal properties of UDD on fecal bacteria Escherichia coli present in the river before and after UDD usage and cleaning method. These promising results demonstrate that UDD can be used to disinfect surface water, providing a biocompatible and reusable new disinfection material for water treatment plants.

Environmental Science Presenter: Báez-Del Valle, Christian D.

Mentor: Perez-Velez, Mariel E.

Title: Determination of Microplastic Concentration and Size Distribution in Personal Care Products to Improve Knowledge of Their Environmental Occurrence

Authors: Christian D. Báez-del Valle (Universidad del Este), Jeremy L. Conkle (Texas A&M University Corpus Christi)

Abstract

Microplastics function as a sorption medium for hydrophobic, organic chemicals and are found in many consumer personal products. Also function as vector for pathogens such as Vibrio spp. Some include toothpaste, face scrubs, anti-aging creams and body wash. After normal use of these personal care products, microplastics go down the drain and into wastewater treatment facilities, where buoyant particles pass through the system and are released into the environment. Their small size (uantity and size distribution of microplastic particles in classes of personal care products that include face scrubs (6), 178

toothpaste (4) and body wash (4). Microplastics were extracted in sizes from 1000 to 50 ?m using standard sieves. For the quantification where use an arithmetical calculation using the mass obtain and the density of the PE (0.96g/mL). Face scrub contained the highest concentration of polyethylene particles (37±0.02 mg/g) with ~80% of mass ranging from 399 to 100 ?m. The average polyethylene mass in products surveyed was 74.2±0.02 mg/g. The overall quantity founded where ~2.24x107 particles of PE in all products. These plastic particles are designed to enter our aqueous waste stream, where some amount is discharged into the environment. Furthermore, ~67±0.02 % of the plastic mass from all the products sampled was

Environmental Science Presenter: Borras-Pacheco, Tania M.

Mentor: Mendez, Loyda

Title: Introducing Toxicology Concepts in General Biology Courses through Inquiry Based Modules.

Authors: Tania M. Borrás-pacheco (School of Science and Technology, URGREAT-MBRS-RISE, Universidad Del Este, Carolina, P.R.), Hector M. Orozco-mercado (School of Science and Technology, URGREAT-MBRS-RISE, Universidad Del Este, Carolina, P.R.), Wilmarie Torres-rivera (School of Science and Technology, Universidad Del Este, Carolina, P.R.), Loyda B. Méndez (School of Science and Technology, Universidad Del Este, Carolina, P.R.)

Abstract

Inquiries based teaching laboratory exercise modules are used as a strategy in science courses to enhance critical thinking, formulate hypotheses, and acquire problem-solving skills among others competencies. In teaching institutions with limited research capabilities, such as ours, most undergraduate (UG) students do not have the opportunity to participate in research projects. Therefore, the main goal of this project was to design inquiry lab modules to introduce toxicology concepts through research activities in the General Biology course, which is usually the first science course students enrolled in life science programs take. The objective of this project is to develop research-oriented activities to assess the adverse health effects of air pollutants. The modules are based on ongoing research efforts at our institution and were developed with UG students who have previously taken the General Biology course. The following concepts were incorporated in the modules: air quality index, bioindicators, model organisms, phylogeny and bioinformatics, toxicity and dose-response relationships. To introduce the air quality index concept, strips for passive sampling of particulate matter (PM) and ozone were used. Lichens were used as bioindicators to assess the relative amount of metals present in PM. Planarians were used as a model organism of mucociliary impairment. Bioinformatics tools were used to generate phylogenetic trees to determine genetic relatedness of invertebrate and vertebrate 179

cilia. To assess toxicity and dose-response relationships, planarians were exposed to increasing concentrations of PM and their locomotion was determined before and after exposure. Determination of the air quality index and data obtained from the lichens provided the basis for UG students to formulate hypotheses to be tested in-vivo with the planarians. While the use of bioinformatics tools allowed students to understand the usefulness of model organisms in toxicology. The feedback from UG students who had previously taken the General Biology course permitted the tailoring of modules to the course syllabus, the time allotted for the laboratories, and to incorporate their suggestions regarding its applications to other science courses. In the future we will implement the modules in the General Biology course and evaluate student attitudes regarding the experience.

Environmental Science Presenter: Bruno Laureano, Yesenia

Mentor: Sabat, Alberto M.

Title: Physiological response of Siderastrea siderea to thermal stress.

Authors: Yesenia Bruno-laureano (University of Puerto Rio, Rio Piedras Campus), Alex E. Mercado-molina (University of Puerto Rio, Rio Piedras Campus), Jaime Fonseca (University of Puerto Rio, Rio Piedras Campus), Fabiola Rivera-irizarry (University of Puerto Rio, Rio Piedras Campus)

Abstract

Warming of the ocean water?is one of the major causes of coral bleaching, a phenomenon that disrupt the?obligate?endosymbiotic?relationships that corals has with dinoflagellates of the genus Symbiodinium. Because it is predicted that sea surface temperature are going to increase 1-3°C in the next 10 years, it is important to understand how coral species will respond to such changes. It is known that the coral Siderastrea siderea is a scleractinian coral common to the Caribbean reefs that has shown to be very resistant to environmental stressors such as sedimentation and water contamination. However, little is known about its capacity to overcome high temperatures. But several studies suggest that Siderastrea siderea can recover faster?than?other corals from thermal-stress. The purpose of this study??is?to determine ?whether the physiology S. siderea?varies with respect to?an increase in water temperature. We conducted a controlled laboratory experiments where the coral were exposed to?typical (27.5°C)?and elevated temperatures (31.5°C).?We?quantified the densities of the endosymbiotic Symbiodinium spp. as well as physiological parameters such as?protein and chlorophyll concentration to determine whether they change in response to?an?increase in temperature. Results show no significant differences or a direct relation between the thermal stress and the physiological mechanisms studied. Which would suggest that S. siderea indeed has the mechanisms to cope to high temperature scenarios.

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Environmental Science Presenter: Castillo Maldonado, Alexis E.

Mentor: Acosta, Angel

Title: Efraín López Cave Characterization: Guano-Soil Analysis

Authors: Alexis E. Castillo Maldonado (Department of Physics and Chemistry, University of Puerto Rico at Arecibo), Angel A. Acosta Colón

Abstract

Efraín Lopéz Cave is located in the north coast karst belt region of Puerto Rico, specifically in the municipality of Isabela, PR. The main objective of this study is to characterize the guano-soil of the cave. For this study we developed a methodology to characterize the guano-soil and its impact to the mesofauna and minerals in the cave. This study presents a geochemical analysis of the guano-soil found at the surface of the cave. The analysis consisted in measuring the acidity (EPA method 9045D), soil moisture, nutritional composition (loss on ignition method) and chemical and mineral composition by using Fourier Transform Infrared (FTIR) spectroscopy and Munsell color value methods as a function of the depth of the cave. The abiotic parameters such as: acidity, water content and nutritional component are the main factor that affect the mesofauna biodiversity of the cave. A positive correlation was found between these parameters and the population of organisms found in the soil-guano. Additionally, a spectroscopy analysis of pre- and post- loss of ignition samples can provide us information of the mineralogy of the soil. This results were validated using optical Munsell color values. The results show a dominance of carbonates and clay minerals and it was expected based on the geology of the surrounding area (San Sebastian Limestone Formation). This study presents methodology that can be used to study cave guano-soil to understand the bio-activity and mineral-activity in the cave. Nonetheless, this can have application to any soil.

Environmental Science Presenter: Classen Rodriguez, Leticia

Mentor: Ramirez, Alonso

Title: Leaf-litter decomposition in urban streams of the Rio Piedras basin

Authors: Leticia M. Classen Rodriguez (University of Puerto Rico - Rio Piedras Campus), Dr. Alonso Ramirez (University of Puerto Rico - Rio Piedras Campus) 181

Abstract

Puerto Rico is an island that experiences an increase in urban growth each year. Studies estimate that approximately 40% of the island is under urban sprawl, especially the metropolitan area. This urban increase alters the processes and functions that occur in stream ecosystems. The objective of this study was to determine the leaf-litter decomposition and aquatic macroinvertebrate assemblages along an urban gradient. Our study watershed was the Rio Piedras, draining the San Juan Metropolitan Area. Six streams were selected varying in their level of urbanization. Six leaf-litter bags were placed in three pools in each stream. We measured the change in weight of the leaf-litter, the rate of decomposition and the macroinvertebrates colonizing the leaves. Results show that the most urbanized streams have lower decomposition rates, in which an approximately 0.04% of the leaf-litter is decomposed per day; while the less urbanized streams decompose approximately 1% of the leaf-litter per day. Macroinvertebrate abundance and richness also responded to the urban gradient, with higher diversity in less urbanized streams. We found that the decomposition rate and macroinvertebrate assemblages are affected by the amount of urbanization on the watershed. Urbanization alters sediment deposition, channel morphology and water chemical composition affecting the processes that occur in an ecosystem, such as leaf-litter decomposition, the macroinvertebrate assemblage and their food webs.

Environmental Science Presenter: Declet Nieves, Carlos G

Mentor: Diaz-Vazquez, Liz

Title: Biosorption of phenolic compounds from aqueous solutions using marine macroalgae

Authors: Carlos G. Declet Nieves (University of Puerto Rico Rio Piedras), Aníbal A. Hernández Vega (University of Puerto Rico Rio Piedras), Sofía B. Marrero-medina (University of Puerto Rico Rio Piedras), Liz M. Díaz-vázquez (University of Puerto Rico Rio Piedras)

Abstract

The contamination of our water resources with inorganic and organic species is an important health issue for which different solutions has been proposed. Some of these solutions include the remediation of waters using biological organisms. However, the use of seaweeds for the bioremediation of contaminated waters have been proved to be a cost-effective mechanisms and without secondary effects for the environment.

In our laboratory, we have been testing the bioadsorption capacity of different species of seaweeds toward phenol and derivatives from aqueous solutions. Phenol and phenolic compounds are generated by, among others, the oil industry and are considered priority pollutants by the US Environmental Protection Agency and the World Health Organization. Different species of the red macroalgae Gracilaria collected from several parts of Puerto Rico's north coast are being tested in their bioadsorption capacity 182

toward these compounds. In addition, different parameters, including pH of the solution and mass of adsorbent, are being optimized to determine the best conditions for the adsorption of these phenolic compounds. The results provide an insight into the adsorption mechanism of phenol and analogues and their use as powerful and inexpensive adsorbents for the treatment of phenol-containing real wastewaters.

Environmental Science Presenters: Diaz Fuentes, Luis Casellas Cruzado, Nicole M.

Mentor: Infante, Gabriel

Title: Traces of Chemical Compounds in Carraízo Reservoir and Sergio Cuevas Water Treatment Plant in Puerto Rico

Authors: Luis A. Díaz Fuentes (Universidad Metropolitana), Nicole M. Casellas Cruzado (NSF), Eduardo J. Estrada Rosado (REU), Gabriel A. Infante Mendez (MSEIP)

Abstract

Using Inductively Coupled Plasma Atomic Emission (ICP-AES) and Atomic Absorption Spectroscopy (AA) techniques and the Environmental Protection Agency (EPA) established procedures certain metals concentrations such as: Al, Ca, Cu, Fe, K, Mg, Na, and Pb on water samples from Carraízo Reservoir and Sergio Cuevas Water Treatment Plant were analyzed. The main goal of his investigation is to compare and examine concentrations of such metals in both, the reservoir and water treatment plant to determine if they comply with the regulations of the EPA and local Environmental Quality Board. Previous results of these analysis have shown that the concentrations of most analyzed metals were lower than the standards established by the regulating agencies. However, the concentrations of Cd, Mn, Al and Pb were higher than the established standards. All the obtained results will be fully discussed during the presentation. It is anticipated that the results of this investigation will provide some appropriate parameters to maintain the quality of water in Puerto Rico.

183

Environmental Science Presenter: Duprey Rivera, Jayleen M

Mentor: Malave-Llamas, Karlo

Title: Diversity of Uncommon Pathogens in Puerto Rico's Recreational Waters and their Impact in Public Health

Authors: Jayleen M. Duprey (Universidad del Este), Daisy Consuegra (Universidad del Este), Josué Lugo (Universidad del Este), Héctor Rosa-lópez (Universidad del Este), Nelson O. Reyes (Universidad del Este), Carlos Rodríguez (Universidad del Este)

Abstract

The vast bodies of water with recreational purposes located in Puerto Rico have been a major attraction not only to the local population but also to tourists from various parts of the world. Therefore, itis important to maintain vigilance on the quality of these recreational bodies of water, thus reducing health risks and infections.The objectives of this research are: (a) evaluate the diversity of pathogens in different bodies of water, (b) compare them to the parameters established by the EPA and EQB of Puerto Rico, (c) assess the public health implications from our samples, and (d) evaluate the anthropogenic factors that influence the rise of the microbial count. For this study, we sample two (2) bodies of water, 30 samples (100ml each) per sampling site, in the north and south-west region of the island.The Membrane Filtration Procedure was used to process the samples and the filters (0.45?m pore size) were incubated on top of Selective and Differential Agar.Bacteria's were counted; Gram stained and identified using the BIOLOG Gen-III System.The Kirby-Bauer Method was used to assess the isolates antibiotic resistant patterns to10 antibiotics.Results showed resistance to Penicillin and Ampicillin and a high degree of susceptibility to Rifampin, Tetracycline and Chloramphenicol.All of the study sites presented some degree of anthropogenic impact and high concentrations of bacteria.Fifty percent of the bacteria identified were from the Vibrio spp.Other species were Proteus vulgaris, Escherichia coli, Klebsiella pneumonia,Comamonas terrigena, Pseudomonas resinovorans, Shewanella algae etc. The presence ofS. algae, P. resinovorans and C. terrigena suggest heavy metal pollution. This is a preliminary study which isin progress and the results obtained will allow usto analyze the water quality on the sample sites; thus understanding the probability of waterborne diseases to the public

184

Environmental Science Presenter: Feliciano, Angel Felix

Mentor: Malave-Llamas, Karlo

Title: The Impact of Pathogens Isolated in Canal Suarez, Puerto Rico, their Antibiotic Resistance and the Negative Effects on Human Health and Economic Activities

Authors: Angel F. Feliciano (Universidad del Este), Jayleen M. Duprey (Universidad del Este), Josue Lugo (Universidad del Este), Nelson O. Reyes (Universidad del Este), Hector Rosa (Universidad del Este), Franco Negron (Universidad del Este)

Abstract

Across the Caribbean, water bodies are found to have unique ecosystems, though abiotic conditions such as temperature and salinity are analogous. The bionetworks of each are composed of a wide variety of organisms which comprise their unique profile. Canal Suarez is a water canal situated on the north coast of Puerto Rico. It is an attraction not only to local fisherman but also to tourists. The objectives of the study are (a) to evaluate the bacterial community of the water canal (b) the anthropogenic influence on the water quality parameters, (c) to compare the bacteria concentration and antibiotic resistant characteristics in the samples, and (d) assess the public health implications from our samples. In this study we took triplicate water samples from three zones; for a total of 60 samples. Samples were diluted by a factor of 10-3 and filtered using the Membrane Filtration Procedure. The samples were incubated on top of TCBS, mENDO, McConkey I-II and Enterococcus Agar at 35oC for 24 hours. Bacteria were counted; Gram stained and identified using the BIOLOG Gen-III System. We identified 52 microorganisms which were 46% Vibrio spp, 21% Klebsiella spp and 33% other species. The Kirby-Bauer Method was used to assess the isolates antibiotic resistance patterns to 10 antibiotics which showed resistance to Penicillin and Ampicillin and a high degree of susceptibility to Rifampin, Tetracycline and Chloramphenicol. This is a preliminary study which will allow us to analyze the water quality of the sample sites; thus understanding the probability of waterborne diseases.

Environmental Science Presenter: Franqui Bernard, Norbert

Mentor: Davila, Saylisse

Title: Adaptive Capacity to Floods: A Case Study of Rincón, PR

Authors: Saylisse Dávila Padilla (Associate Professor at University of Puerto Rico at Mayaguez), Norbert Franqui Bernard (Student at University of Puerto Rico at Mayaguez), Lourdes 185

Medina Aviles (Asistant Professor at University of Puerto Rico at Mayaguez), Melissa Carrasco Gonzales

Abstract

The detrimental effects of floods and tsunamis in Caribbean islands are well known and numerous efforts, such as the Tsunami Warning Program, have focused on mitigating the effects of these natural hazards. The construct of vulnerability is often used as an attempt to quantify how susceptible geographical locations are to different natural hazards, and it is typically depicted as a function of exposure, sensitivity, and adaptive capacity. This work focuses on developing an instrument to measure the vulnerability dimension of adaptive capacity, which, in turn, can be characterized in terms of how well individuals prepare for (mitigation), address (response), and overcome (recovery) any given natural hazard. The instrument was developed to capture all three dimensions of adaptive capacity and targeted floods in the municipality of Rincón, PR (including both residents and tourists). The questionnaire was carried out in a series of interviews on a stratified sample of size 138. Results will include the validation of the instrument using Cronbach's alpha for the three dimensions of adaptive capacity

Environmental Science Presenter: García Y Robles, Frances

Mentor: Roberson, Loretta

Title: Assessment of San Juan Bay Estuary water quality from 2012- 2015

Authors: Frances García-robles (University of Puerto Rico Rio Piedras Campus), Mayra Sánchez- garcía (University of Puerto Rico Rio Piedras Campus), Claudia P. Ruiz (University of Puerto Rico Rio Piedras Campus), Loretta Roberson (University of Puerto Rico Rio Piedras Campus)

Abstract

Estuarine ecosystems are dynamic, they are subjected to periodic natural changes from the mixing of freshwater from rivers and saltwater from the sea. Moreover, anthropogenic activities like septic tank inputs and urban expansion have led to sharp declines in water quality. In this study we identify how many stations in the San Juan Bay Estuary (SJBE) do not comply with the Puerto Rico Water Quality Standards (PRWQS) based on several physicochemical parameters (i.e. dissolved oxygen, pH, and turbidity) at 25 stations as well as fecal coliform and Enterococcus from 3 stations. Physicochemical data were collected at monthly intervals and microbiological data were collected biannually from 2011-2015 published at SJBE program web page (www.estuario.org). The San Juan Bay Estuary is one of the largest estuaries in Puerto Rico, containing a third of all mangrove forests in Puerto Rico that provides homes to more than 160 bird, 19 reptiles and amphibian species, 124 fish species, and 300 species of wetland 186

plants. Additionally, the SJBE is of great economic importance to Puerto Rico because it receives most of the imported products and cruise ships for the island. Our results show that the overall water quality of the SJBE is in non-compliance with PRWQS. On average, 14/25 stations are below the dissolved oxygen requirement, 9/25 have high turbidity, and 4/25 stations have a pH above or below the optimum level every month of the year. Additionally, the microbial water quality for fecal coliforms and Enterococcus exceeds the PRWQS limits. The biological data suggest that the urban environment around the SJBE may be a significant factor affecting water quality, altering water chemistry and leading to negative impacts on the aquatic flora and fauna that inhabit this ecosystem.

Environmental Science Presenters: Gómez Frontera, Joffre E. Burgos Figueroa, Edmundo A.

Mentor: Peez-Matos, Ana

Title: Chemical and Microbiological Remediation of Nickel in Guánica Bay

Authors: Joffre E. Gómez Frontera (UIA-SAN GERMAN), Edmundo A. Burgos Figueroa (UIA-SAN GERMAN)

Abstract

Guánica Bay is one of the most important estuaries in southern Puerto Rico. However, this estuary has been impacted by the excessive discharge of organic pollutants such as PCB's and PAH's, and inorganic pollutants such as heavy metals. Nickel (Ni), a heavy metal reported in the bay, may affect the ecosystem, and human health. Furthermore, Ni is related to pulmonary diseases and cancer in humans. Therefore, any attempt to remove this heavy metal from Guánica Bay becomes necessary. On this basis, adsorption of Ni onto easily available polymeric chitosan-cellulose matrixes exhibiting adsorption capacities on heavy metals, and the use of Ni resistant bacteria for the remediation of Ni will be evaluated. The expected results should evidence that by incorporating these chemical and microbiological methods, Ni concentrations will be decreased in the water column and in sediments. An initial sediment sample yielded Ni resistant bacterial isolates. These bacterial isolates will be characterized to determine their level of resistance to Ni. Furthermore, additional sediment samples will be collected from different sites around Guánica Bay in order to isolate additional Ni resistant bacteria.

187

Environmental Science Presenter: Liquet Y Gonzalez, Jose E.

Mentor: Rios Velazquez, Carlos

Title: Detection of Fungal's Capabilities to Degrade 2,4,6-Trinitrotoluene Using Cyclic Voltammetry

Authors: Jose Liquet Y Gonzalez (University of Puerto Rico-Mayagüez), Jorge Castellanos (University of Puerto Rico-Mayagüez), Issac Cortez (University of Puerto Rico- Mayagüez), Viridis Miranda (University of Puerto Rico-Mayagüez), Ricky Padilla (University of Puerto Rico-Mayagüez), Freddie Morales (University of Puerto Rico- Mayagüez)

Abstract

2,4,6-Trinitrotoluene (TNT) is a man-made explosive used in military shells, bombs, and grenades, in industrial uses, and in underwater blasting. Besides TNT presence and distribution in the environment throughout diverse locations, it is also known to accumulate in animals and plants. Although its effects on human health are not completely understood, the Environmental Protection Agency, has classified it as a possible human carcinogen. Biodegradation is regarded as an option to clean up many environmental pollutants. However, there is a need for TNT biodegradation experiments using fungi where the metabolic activity can be easily detected. Cyclic voltammetry (CV) is an electrochemical technique that applies an alternating potential, oxidizes and reduces molecules, producing a detectable current signal. The main focus of this research is the use of CV as an effective technique to detect the TNT degradation capabilities of a fungal bioprospect isolated in Puerto Rico. Spores suspensions of the prospective TNT-degrader, Aspergillus sp., were spreaded on Potato Dextrose Agar, and after 7 days of incubation, 5mm fungal disks were placed in tubes with Bushnell-Haas broth with 68 ppm TNT for 58 days. After applying CV for TNT, three reduction peaks were observed with decreasing potential and a prominent oxidation peak in the return sweep at 0.050V (peak 4). Each of the resulting reductions were identified sequentially as the two "ortho" (peak 1 and peak 2) and "para" (peak 3) nitro groups with respect to the methyl group at -0.545, -0.745 and -0.885 V (vs saturated Ag/AgCl). In the the first five days of incubation, the TNT concentration decreased almost 10ppm on average as per Peak 1 and Peak 4. After 58 days of incubation, the TNT concentration had decreased almost 20 ppm on average for the mentioned peaks. For Peak 2 and 3 we did not found a drastic decrease in concentration, only a reduction of 8ppm on average after 58 days of incubation. There was no noticeable change in the fungus morphology after 58 days of incubation with exposure to TNT, determined by using a scanning electron microscope. Further studies to determine the biodegradation product are underway. These findings could potentially propose a cost-effective mechanism to biodegrade environmental TNT into a less- hazardous compounds. Moreover, it is expected to be able to discover enzymes with particular industrial purposes.

188

Environmental Science Presenter: López-Carrasquillo, Jonathan J.

Mentor: Perez-Jimenez, Jose R.

Title: Diversity of Sulfate Reducing Bacteria in Response to a simulated hurricane at El Yunque Rain Forest

Authors: Jonathan López-carrasquillo (Universidad del Turabo), José Pérez-jiménez (Universidad del Turabo)

Abstract

Sulfate-reducing bacteria, SRB, are relevant participants of sulfur and carbon biogeochemical cycle in anoxic environments, such as hypersaline sites, minimal oxygen zones in oceans, mangrove sediments and elfin forest soils. A Canopy Trimming Experiment, that simulated the pass of a hurricane, has been done in the Tabonuco forest. Samples were collected at various times to monitor changes in microbiota. Our goal is to determine temporal diversity of SRB among the experimental plots as consequence of detritus deposition of the simulated hurricane. Soil samples were collected from plots, every week. Two treatments were applied: with and without detritus deposition trimmed from the local canopy. Total genomic DNA was extracted for amplification of the dissimilatory sulfite reductase gene (dsrAB) and terminal restriction fragment length polymorphisms analysis of their MboI digests. According to the Dice similarity index, under no detritus deposition, the similarity decreased as time progress, 44% at time 0 to 17% at week 10. In contrast, diversity increased over time where detritus was added. Sulfidogenic abundance was lower in the absence of detritus: 33 versus 94 phylotypes. The overall sulfidogenic community was dominated by major phylotypes decreasing over time. Only two phylotypes, 184- and 474-bp, persisted for both treatments and the five time periods examined. A simple sulfidogenic community seems to prevail in the Tabonuco forest soils that diversify as anoxic conditions are exacerbated by the addition of plant residues and their sulfate-containing residues are released to the soil. qPCR and Next Generation Sequencing will be applied to further characterize the sulfidogenic microbiome.

189

Environmental Science Presenters: Morales Dávila, Alexandra Rodriguez Velazquez, Adolfo

Mentor: Conde, Carlos

Title: Heterotrophic microbial production at selected cave-associated streams, Puerto Rico

Authors: Carlos Conde Costas (University of Sacred Heart), Adolfo Rodríguez Velázquez (University of Sacred Heart), Alexandra Morales Dávila (University of Sacred Heart), Ileana Fasick Fumero (University of Sacred Heart)

Abstract

In streams ecosystems heterotrophic microorganisms are important components of the benthic or submerged surfaces communities. A major role of the benthic microbial communities is the assimilation and retention of dissolved organic matter and nutrients from the overlying water. Many tropical cave streams receive a large input of organic material and nutrients in the form of bat's metabolic solid and liquid wastes (guano). A literature review revealed that the dynamics of benthic heterotrophic microbial production (the amount of biomass generated over a given time) in cave-associated streams is poorly documented. Thus, in order to examine and further validate hypotheses concerning the impact of bat populations in such processes, measurements of the benthic microbial metabolic activity were determined at the Rio Camuy, Aguas Buenas and Convento cave-associated streams by following changes in oxygen concentration as an indicator of benthic microbial respiration. Relevant findings concerning benthic heterotrophic microbial production and assimilation capacity in such representative cave-associated streams are discussed.

The ecological importance of these processes is is the transfer of odissolved organic carbon to the stream bottom wher it can be metabolized by te benthic hetrrotrophic microbial thus retaining dom. Caves ecosystem by means of bat guano are a source of DOC. Differences will depend on the quality . Measurements of microbial metabolic activity can be compared and contrasted amon different representative cave-associated streams.. Such can be measured by measuring oxygen concentration as a measure of respiration an indicator of metabolic activity.bat population species and diversityAssimilatory uptake by heterotrophs is mostly responsible for the retention of organic matter and inorganic nutrients. Was investigated at Production is the amount of biomass generated over a given time and productivity is the rate of biomass production per unit time. The speleolotic (cave- stream) systems are heterotrophic systems that rely almost entirely upon allochthonous sources of organic matter imported from the surface.

The purpose of the investigation is to examine the heterotrophic microbial production at distinctive cave-associated streams by quantifying the metabolic activity of the benthic community. Measurements will be compared and contrasted among the selected streams. The study will be conducted at the Rio Camuy, Aguas Buenas and Convento cave associated streams due its representative natural trophic conditions and exceptional ecological value. The study will test the following hypotheses: The rate of 190

heterotrophic microbial productivity is dependent on the water temperature and the quality and concentration of the organic matter. An increase in water temperature will increased the respiration rate of the heterotrophic microbial community. Results will contribute to elucidate relevant aspects about the intensity of heterotrohic communities. Results are expected to promote further research.

Microbial community metabolisms and response to experimental treatment will be determined by following changes in oxygen concentration Change in oxygen concentration as a measure of microbial respiration. There is expected difference among the selected cave stream and the metabolic response of heterotrophic microbial communities to treatments can

Environmental Science Presenter: Nevárez, Maritza

Mentor: Perez-Velez, Mariel E.

Title: Daily samples monitoring of nutrients and water quality control in urbanized estuaries in Corpus Christi, Texas

Authors: Maritza Nevárez Cruz (School of Science and Technology, Universidad Del Este, Carolina, Puerto Rico), Michael Wetz (Estuarine and Coastal Dynamics Lab, Texas A&M University Corpus Christi)

Abstract

Drastic impacts in ecosystems are observed worldwide in recent decades by the massive urbanization because of life styles of human being. Estuarine life is one of the most affected ecosystems. The excessive use of pesticides in agriculture then wasted in estuaries can be a cause of vast changes in terms of nutrients and the sustaining life itself. Eutrophication or excessive concentration of nutrients is a phenomenon that has been observed in recent years in these water bodies. The increase of organic matter through the bays and estuaries does not allow the exchange of oxygen, photosynthesis and essential nutrients for life in the estuaries. Hypoxia or low oxygen levels can affect an ecosystem and species that cannot adapt providing dangerous conditions to this underwater environment. Changes in water quality parameters, such as salinity and eutrophication can cause events of brown tides or other algal blooms which negatively impact the estuarine product consumption that reduce the light penetration and prevent fishery products for consumption fully develop and die. This phenomenon observed in different estuaries of Corpus Christi prevents major processes for the survival of estuarine biology. A period of seven weeks has been monitored at the Oso Bay next to Corpus Christi Bay by the Estuarine and Coastal Dynamics Lab, water samples were taken daily. We believe hypoxia events in the ecosystems can be observed and brown tides in other estuaries can be predicted. The water quality parameters indicate that there is relationship between the winds and the dissolved oxygen in water surface. The increased levels of chlorophyll-a indicated that there was greater amount of phytoplankton 191

in response to eutrophication in underwater ecosystems. The results analysis allows us to know and predict hypoxia events in the estuarine environment and algal blooms events.

Environmental Science Presenter: Pabón Castro, Angélica L.

Mentor: Mendez, Loyda

Title: Concentration and Particle Size Distribution of Endotoxin and Beta-glucan Present in Ambient Particulate Matter

Authors: Angélica L. Pabón Castro (Universidad del Este), Emmanuel Gonzalez Figueroa (Universidad del Este), Wilmarie Torres Rivera (Universidad del Este), Loyda B. Mendez Torres (Universidad del Este)

Abstract

Asthma is the most common chronic childhood disease in the US. Among the environmental factors associated with increased asthma morbidity are exposures to indoor allergens, bioaerosols (e.g. endotoxins and beta-glucans) and air pollutants, such as particulate matter (PM). The main objective of this study was to determine the concentration and size distribution of endotoxin and beta-glucans present in ambient PM. Air samples were obtained in the vicinity of an elementary school in Puerto Rico. Samples were collected for 2 consecutive weeks with an 8-stage cascade impactor and particles were extracted from the filters with pyrogen-free water by sonication for 2 hours. Endotoxin and beta-glucans present in each stage were measured using a kinetic chromogenic limulus amebocyte lysate and glucatell assay, respectively. The mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD) were calculated using the log-probability method. Endotoxin concentrations varied between 0.78 and 18.80 pg/m3. In contrast, the beta-glucans levels ranged between 87.52 and 522.77 pg/m3. Approximately 50% of the detected endotoxins and beta-glucans were associated with particles of 2.5 ?m or less in diameter. This data will be used as complimentary information for exposure assessments to evaluate if endotoxin and beta-glucans present in ambient PM are associated with respiratory effects in asthmatic children.

192

Environmental Science Presenters: Perez Rodriguez, Celimar Ramos Solis, Nicole

Mentor: Perez-Rivera, Raul A.

Title: Reproductive niche segregation of four species of Columbiformes, at the campus of the UPR-Humacao

Authors: Celimar Perez Rodriguez (University of P.R at Humacao), Raul A Perez Rivera (University of P.R at Humacao), Nicole Ramos Solis (University of P.R at Humacao)

Abstract

The Ground Dove (Columbina passerina portoricensis), the White-winged Dove ( Zenaida asiatica), Zenaida Dove (Z. aurita), and the Red-necked Pigeon (Patagioenas squamosal) are resident at the campus of the UPR-Humacao. The objectives of the work were to determine where the species were nesting and if these were segregating the reproductive niche. Since 2014 to 2015 we examined the campus' vegetation every week to determine the places used for nesting by these species. Once a nest was found we identified the vegetation, used a binocular to identify the species attending the nest and used a calibrated bar to determine the height of the nest. The Ground Dove used the lowest vegetation substrate (under 20 ft), particularly pruned trees, and artifacts such as empty boxes of air conditioning units. Average nesting height was 9.5 ft (range 4-20 ft). The White-winged Dove used the middle strata with a preference to trees of Ucar (Bucida buceras; 57 nests) and White-oak (Tabebuia heterophylla; 42 nests). The average height of nesting was 24 ft (range 15-45 ft). Only a few nests were found of the Zenaida Dove in 2014 and none in 2015. Particularly, species are using for nesting vegetation not used by other pigeons and the data recollected didn't allowed us to determine preferences. Meanwhile, the Red-necked Pigeon used the upper strata nesting particularly on Caribean Pine (Pinus caribaea), Australian Pine (Casuarina equisetifolia), and the Royal Palm (Roystonea borinquena). The average nesting height was 41 ft (range 23-55). In conclusion the species seems to be segregating the reproductive niche and the White-winged Dove seems to be eliminating competitively the Zenaida Dove.

193

Environmental Science Presenter: Ramos Solis, Nicole

Mentor: Perez-Rivera, Raul A.

Title: Construction of a nest for sleeping and breeding by the Bananaquit (Coereba flaveola portoricensis) at the campus of the UPR-Humacao.

Authors: Nicole Ramos Solis (University of P.R at Humacao), Celimar Pérez Rodriquez (University of P.R at Humacao), Raúl A. Pérez River (University of P.R at Humacao)

Abstract

The Bananaquit (Coereba flaveola portoricensis) is one of the most common and abundant birds of Puerto Rico. The bird can be observed from the mountain range to the lowlands of the Island. Nests of this species can be found year around, since the Bananaquit construct nests for sleeping. The objectives of this work were to determine if the bird breeds year around, and if there are differences between the vegetation and height used to construct nests used for roosting and breeding. Our hypothesis was that the bird should construct a nest for breeding in places higher and more protected than the nest for roosting. We examined four hundred and thirty five nests of Bananaquit during the years 2014 and 2015. We found one hundred and eighty nine nests used for nesting and two hundred and forty six for roosting. We found nests with eggs or chicks throughout the year. The pair of Bananaquit could use the material of the roosting nest to construct a nest for breeding. No nests were reused, although this behavior has been reported in urban areas. We found nests for breeding in fourteen species and seven for roosting on trees, respectively. The trees more commonly used for nesting were Tabebuia heterophylla (tween one), Calophyllum calaba (nineteen), Delonix regia (eighteen) and Sweitenia mahogany (fourteen). The average height of the nest was 6.05 m (range1.14 -15.41). The vegetation most commonly used for roosting was Tabebuia argentea (fifty-nine), Calophyllum calaba (fifty) and Delonix regia (Forty-one). The average height for roosting nests was 6.49 m (range 1.05 – 13.64). There was no significant difference between the height used for nesting and roosting (t-test). Nevertheless, the results imply that the bird construct nests higher in the vegetation for sleeping than breeding, which make us reject our hypothesis. In conclusion, the Bananaquit nest year around, and construct nests for roosting and breeding in similar vegetation and similar height.

194

Environmental Science Presenter: Rodriguez Velazquez, Adolfo

Mentor: Johnson, Jerry

Title: Determining the habitat and microhabitat utilized by two species of rattlesnakes (Crotalus atroxandCrotalus ornatus) using radiotelemetry at Indio Mountains Research Station, Hudspeth County, Texas

Authors: Adolfo Rodríguez Velázquez (Universidad del Sagrado Corazón), Jerry D. Johnson (University of Texas at El Paso), Vicente Mata Silva (University of Texas at El Paso), Dominic De Santis (University of Texas at El Paso)

Abstract

Long-term radio telemetry studies investigating the ecology and behavior of two large-bodied rattlesnakes, Crotalus atrox and Crotalus ornatus have been ongoing since 2008 at Indio Mountains Research Station (IMRS) Hudspeth Co, Texas, in the northern Chihuahua Desert. Despite being two ecologically similar species with small mammal-based diets, both C. atrox and C. ornatus occur in sympatry throughout the Chihuahuan Desert. The goal of the study reported herein was to compare and examine for differences in patterns of habitat and microhabitat selection between these two species on IMRS. Five individuals of each species (C. atrox and C. ornatus) were tracked for varying durations over a three-year period (2008-2010). Thus far, during the summer of 2015, two C. ornatus and one C. atrox have been radiotracked, and all data collected regarding habitat and microhabitat selection were used to supplement the existing dataset. Habitat and microhabitat data were also recorded for the point of capture for individuals encountered but not radiotracked. Preliminary data suggests that these two rattlesnakes differ in both habitats and microhabitats utilized at IMRS. Crotalus atrox was found most frequently on alluvial slopes, alluvial flats, and in arroyo habitats; most representing habitats below the increasingly rocky western slopes of the Indio Mountains. Conversely, C. ornatus were more often found on rocky slopes, alluvial rocky slopes, and alluvial slope habitats; habitat types associated with steep, rocky terrain. In terms of microhabitat selection, C. atrox was most often found within burrows, while C. ornatus was observed more frequently in cracks and/or under rocks. These preliminary findings suggest potential partitioning of habitat, microhabitat, and thus resources by these two ecologically similar Chihuahuan Desert rattlesnakes an IMRS.

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Environmental Science Presenter: Rodriguez-Gonzalez, Mayra I.

Mentor: Ortiz-Zayas, Jorge

Title: Land-use change implications on landscape quality for the identification of priority conservation zones: a case study in Las Cucharillas Marsh, Cataño, PR

Authors: Mayra Rodríguez-gonzález (Department of Biology, University of Puerto Rico at Bayamón, Bayamón), Arístides Martínez-cintrón (Department of Environmental Science, University of Puerto Rico, Río Piedras), Jorge Ortiz-zayas (Department of Environmental Science, University of Puerto Rico, Río Piedras)

Abstract

Natural and anthropogenic disturbances have caused an array of changes in forested wetlands and other natural land-use classes in the Island. Assessing indicator plant species distribution and soil quality in Las Cucharillas Marsh, an ecological hotspot for the San Juan Bay Estuary and buffer zone against water runoff and industrial waste in Cataño, can help evaluate land-use effects on valuable and resource-rich landscapes. This kind of assessment, however, cannot be achieved until land-use change itself is evaluated. With this goal in mind, aerial photographs and colonial maps were used to digitize and depict land-use trajectories since the late 1800s. Initial results from this ongoing project showed a noticeable increase of urban areas due to social and economic factors. Implications of this findings include the constant decrease of natural areas and the ongoing pollution that affects residents of Cataño. Therefore, the development of a framework for the identification of priority conservation zones is of crucial importance. Time and resources, however, limited the successfulness and completion of this stage. Nonetheless, continuing to pursue this project can shed light to many environmental issues not being addressed in the municipality of Cataño and serve as benchmark for the development of similar studies across the Island.

Environmental Science Presenter: Rosaly Velazquez, Sara M

Mentor: Colon, Abner

Title: Analysis of heavy metals in the Cerrillos Reservoir of Ponce, Puerto Rico

Authors: Abner Colon (PCUPR), Sara Rosaly Velazquez (PCUPR) 196

Abstract

Water is a natural resource essential for life. 97.24% of the water on earth is in the oceans, while 2.76% of the water is distributed in rivers, glaciers, atmosphere, groundwater and lakes (US Geological Survey, 1984). Lakes ecosystems support complex and important interactions provide food chains and habitats necessary to support numerous endangered species (EPA, 2013). Cerrillos Reservoir, located in the city of Ponce, is one of the largest reservoirs in southern Puerto Rico area. Its construction was completed in 1992 by the US Army Corp of Engineers. It is even larger reservoir in the Caribbean. The main purposes of Cerrillos Reservoir Ponce, Puerto Rico are to control floods, supply water to the inhabitants and recreation (US Geological Survey, 2008).

The purpose of this research was to determine the presence and concentration of heavy metals in the Cerrillos Reservoir of Ponce, Puerto Rico. To analyze the purpose of this study a simple sampling of heavy metals was performed at three points Reservoir Cerrillos Ponce for a period of six months, which were identified as area A, B and C. Area A, it was held at the entrance the main river that supplies water to the reservoir. The area B was conducted at the midpoint of the reservoir. Finally, Zone C, was part of deeper and water storage reservoir. These samples were analyzed using an Inductor Coupled Plasma Optical Emission Spectroscopy (ICP-OES 3300 XL).

Environmental Science Presenter: Salazar Ortiz, Monica

Mentor: Cuevas, Elvira

Title: Cambios en el uso y manejo de los terrenos que comprenden el actual Manglar Maracayo y sus alrededores en Camuy, Puerto Rico y su impacto en la ecología del área

Authors: Mónica Salazar Ortiz (UPR-Rio Piedras), Elvira Cuevas (UPR-Rio Piedras)

Abstract

A través de la historia de Puerto Rico, las necesidades económicas y políticas han provocado cambios en los usos de los terrenos para la agricultura, ganadería y, actualmente, para el desparrame urbano. Por esto, esta investigación se especificó en documentar los cambios producidos por los distintos usos y manejos dados a una finca colindante al mar en la costa norte de Puerto Rico. El área de estudio se encuentra en el municipio de Camuy, Puerto Rico. En el área de estudio, se encuentra actualmente el Manglar Maracayo, un manglar cuyos terrenos han sufrido cambios en su uso y manejo. El objetivo de nuestro estudio es reconstruir de qué manera la historia del uso y manejo de los terrenos han impactado el área de lo que hoy en día es un manglar. Se hipotetiza que el impacto del cambio en el uso y manejo de estos terrenos afectó la hidrología del área, dando paso como resultado la salinización del área, dejando el nicho adecuado para el desarrollo del actual manglar. Los recursos que se estudiaron fueron una serie de fotografías aéreas del pasado siglo del área, recopilación de historia oral de los 197

ciudadanos que viven aledaños a los terrenos para conocer su estado del pasado, hallar documentos de análisis del manglar en el pasado y análisis de la actual salinidad, pH, conductividad, porcentaje de humedad, carbono orgánico y mineral de los suelos en tres sitios distintos en el manglar. Se concluye que el manglar ha sufrido cambios en la composición del ecosistema por la extracción de las dunas de arena, evidenciado por el análisis en ArcGIS. Con la recuperación de las dunas de arena, el área, con dos ojos de agua existentes, presenta una hidrología totalmente cambiada a la registrada en el estudio hecho en el 1979. La continuidad de estudios ecofisiológicos e hidrogeológicos de esta área son inminentes para entender este ecosistema en su plenitud.

Environmental Science Presenter: Santiago Cárdenas, Vanessa

Mentor: Roberson, Loretta

Title: Concentration and temporal distribution of contaminants of emerging concern in the San Juan Bay Estuary from 2012 to 2015

Authors: Vanessa Santiago-cárdenas (Department of Biology, UPR-Río Piedras, San Juan, PR.), Xochitl Perez (Department of Environmental Science, UPR-Río Piedras, San Juan, PR.), Claudia Ruiz-diaz (Department of Environmental Science, UPR-Río Piedras, San Juan, PR.), Alexander Rodriguez (Department of Environmental Science, UPR-Río Piedras, San Juan, PR.), Liz Diaz-vazquez (Department of Chemistry, UPR-Río Piedras, San Juan, PR.), Loretta Roberson (Department of Environmental Science, UPR-Río Piedras, San Juan, PR.)

Abstract

Contaminants of emerging concern (CECs) are chemical compounds that could harm the environment and human health but are not regulated or commonly monitored. Many of these chemicals are frequently used as pharmaceutical products, plasticizers, solvents, and poly-aromatic hydrocarbons, and leach into the aquatic environment altering the pH, nutrient concentration and water temperature of aquatic ecosystem.

The exposure of these chemical have been linked to declines in a number of wildlife species. For instance, crabs and fishes exposed to some of these chemicals have been linked to reproductive failure, abnormal developmental, behavioral, neurologic, endocrine, and immunologic disorders. One such place impacted by CECs is the San Juan Bay Estuary of Puerto Rico (SJBE).

The SJBE is located in the northern coast of Puerto Rico and as is the only estuary, among the 28 National Estuary Program sites, located in a densely populated, intensely industrialized, highly developed, and ecologically sensitive tropical area. Therefore, it is highly impacted by human activities. The specific aims of this study are to: (1) quantify the concentrations of ten contaminants of emerging 198

concern in the San Juan Bay Estuary of Puerto Rico (SJBE); (2) compare the spatial and temporal variation in concentration of these contaminants in the SJBE during four years of monitoring.

To address these questions, water samples were collected at 16 stations annually from 2012 to 2015. Samples were processed by solid-phase extraction using ethyl acetate as elution solvent and liquid-liquid extraction using dichloromethane as solvent. All samples were analyzed by gas chromatography-mass spectrometry and identified with AMDIS-NIST computer program. Ten different targets compounds were quantified: dibutyl phthalate, diethyl phthalate, caffeine, acetophenone, benzyl benzoate, 1,4- diclorobenzene, hexadecane, naphthalene, tributyl phosphate and benzaldehyde.

The results show that the concentration of CECs varied through time and across stations. Also, that several compounds such as dibutyl phthalate and diethyl phthalate are persistent in the SJBE. The most prevalent contaminant quantified was dibutyl phthalate, which appear in most sites every year. Most compounds show the influence of human activity; also, water flow may be responsible for differences in concentrations among sampling sites. With this analysis we can have a better understanding of the ecosystem and the risk to estuary organisms.

Funding Acknowledgement(s): This project has been supported by the NSF CREST Grant # HRD-1137725, through the Puerto Rico Center of Environmental Neuroscience and the Department of Environmental Science, UPR-Río Piedras, San Juan, PR.

Environmental Science Presenters: Santiago Pagan, Melanie Alvarado Pujals, Veronica N.

Mentor: Santiago, Xiomara

Title: Epidemiological Study of a Community in the Southern Area of Puerto Rico

Authors: Xiomara Santiago Rodriguez (University of Puerto Rico- Cayey), Ismael Santiago (University of Puerto Rico- Cayey), Gabriel Ramos (University of Puerto Rico- Cayey), Flor C. Diaz (University of Puerto Rico- Cayey), Yllen Figueroa (University of Puerto Rico- Cayey), Jennifer Ramos (University of Puerto Rico- Cayey), Marielys Morales Diaz (University of Puerto Rico-Cayey), Tanya D. Lebrón Steidel (University of Puerto Rico- Cayey), Abraham Torres (University of Puerto Rico- Cayey), Melanie Santiago Pagan (University of Puerto Rico- Cayey), Verónica N. Alvarado Pujals (University of Puerto Rico- Cayey), Anamaris E. Torres Colón (University of Puerto Rico- Cayey)

Abstract

The Rio Jueyes Sector of Coamo has increased in numbers of affected residents with various diseases like respiratory, different types of cancer and other health conditions. However, the origin of such 199

escalation is unknown. The main objective is to carry out a descriptive study of the most common diseases suffered; in addition, to have a collective of data on socio-demographic characteristics of the community. Never the less, to define which factors are causing the dramatic increase in cases in the sector. Also, determine if residents are aware of the risks near the community and if they have any preventive measures. If not, develop one with the purpose to improve their life quality, and finally, to identify what kind of people are affected by these different diseases and conditions.

Environmental Science Presenter: Santiago-Nieves, Casandra L.

Mentor: Perez-Jimenez, Jose R.

Title: Bioprospecting: Xylose-fermentating Bacteria for Biofuel

Authors: Casandra Lee Santiago-nieves (Universidad del Turabo), Yomarie Bernier-casillas (Universidad del Turabo), José R. Pérez-jiménez (Universidad del Turabo)

Abstract

Fermentation of lignocellulosic components is improving the ability to produce biofuel and recycling agricultural waste. Xylose fermentation at high yields for the development to ethanol processes has been documentated. Microorganisms, mostly fungi or recombinants with bacteria have been found to ferment xylose. The Caño Martín Peña in San Juan, Puerto Rico is a natural resource of the capital as it is an area for recreation for habitants and tourist; however it is also known for its contaminated waters. The objective is to isolate, characterize and identify xylose-fermentating bacteria for cost-effective biofuel production. Soil samples were collected from the Caño Martín Peña, which were then inoculated on modified rich media. Tests were performed with the Durham Tube Test and on xylose broth, which were incubated at 37°C for 24 hours. Isolates were further characterized through 16S rDNA sequencing. Results have shown xylose-fermentating bacteria and others that do not ferment xylose but grow in the media. Among seventeen isolates, seven Klebsiella species were identified to positively ferment xylose. The remaining isolates will be further characterized and identified. Caño Martín Peña harbors novel strains of bacteria capable of xylose fermentation.

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Environmental Science Presenter: Valle Perez, Nicole

Mentor: Reyes-Colón, Carmen María

Title: Rat eradication project as a habitat restauration strategy for the management and protection of Isla Del Frio Cay in Ponce, Puerto Rico

Authors: Nicole Valle Perez (presentor), Carmen Reyes (mentor pucpr), Eduardo Ventosa (biologist in field)

Abstract

This project consists of the conservation and protection of habitat and bird species that inhabit the Isla del Frio Cay. The population of marine birds inhabiting the cay has been affected by the invasion of rats in different cays in Puerto Rico. This problem results in the decline of birds and reptiles population in many small islands or cays by 40-60%. The reason for this situation is the invasion of rats which are considered responsible for the endangerment or extinction of species that live on islands. Twenty-four sampling points were examined During October 30 and November 11 of 2015. At each trap located in the sampling point 84.40 g of poison were placed. The traps were examined daily and the remains were taken to the laboratory to weight poison leftovers. Consumption of the poison was very low at the end of the survey period indicating the success of the project. A bird census will be conducted to know if the population return to the island and to measure the success of the project.

Environmental Science Presenter: Vazquez Maestre, Bethany

Mentor: Ramirez, Alonso

Title: Ensamblajes de macroinvertebrados en quebradas de bosque en Puerto Rico: Importancia de los camarones y los factores climáticos

Authors: Bethany Vazquez Maestre (Universidad de Puerto Rico - Rio Piedras), Alonso Ramirez (Universidad de Puerto Rico - Rio Piedras)

Abstract

Los factores abióticos y bióticos son importantes estructurando las comunidades bénticas de las quebradas. Dos factores importantes que interactúan entre si son el clima (factor abiótico) y los depredadores / competidores (biótico). En las quebradas de Puerto Rico los ensamblajes de macroinvertebrados están controlados por la presencia de macroconsumidores. Las sequias afectan la 201

disponibilidad de hábitats para ambos grupos, lo cual puede causar interacciones más frecuentes entre los consumidores y sus presas. ¿Cuál es la composición de ensamblajes de macroinvertebrados en dos quebradas tropicales? y ¿Qué papel juegan los camarones y la sequía en determinar los patrones de distribución en los macroinvertebrados? Las variaciones espaciales en abundancia de los camarones resultaran en cambios en los ensamblajes de insectos acuáticos dentro de hábitats de pozas y rápidos. La sequia reducirá los hábitats disponibles incrementando la densidad de camarones, lo cual podría influenciar los ensamblajes de macroinvertebrados. Se estudiaron dos quebradas (Prieta y Bisley) en el bosque Experimental de Luquillo, Puerto Rico. Estas son similares en elevación y vegetación, pero contrastan en abundancia de camarones (Prieta: ~35 camarones/m2; Bisley ~1 camarón/m2). El periodo de estudio fue durante una sequía moderada en junio-julio 2014 y otra severa en junio-julio 2015. Se muestrearon seis pozas por quebrada utilizando un nucleador (0.025m2) y seis rápidos utilizando un Surber (0.023m2). Con respecto al primer año de muestreo, se observó un incremento en la riqueza taxonómica de macroinvertebrados en pozas y rápidos en ambas quebradas (promedio: 3-6/m2). Sin embargo, la abundancia solo incrementó en las pozas (promedio: 300-1500/m2). En el primer año de muestreo los camarones fueron el factor principal estructurando el ensamblaje de macroinvertebrados, mientras que en el segundo periodo la reducción de flujo, causado por la sequía, afectó los camarones que a su vez influenciaron los macroinvertebrados. Los resultados apoyan nuestra hipótesis de que los macroinvertebrados son afectados por la presencia de camarones. Sin embargo, eventos a gran escala como la sequía son factores que dominan y enmascaran el efecto de los camarones sobre los otros organismos. Nuestro estudio determinó que los ensamblajes de macroinvertebrados están relacionados a la presencia de macroconsumidores, pero que las sequías tienen una influencia importante sobre las comunidades bénticas.

Environmental Science Presenter: Velazquez Cruz, Johnathan

Mentor: Cantrell, Sharon A

Title: Microbial diversity and nutrient mineralization in green litter decomposition in a simulated hurricane experiment.

Authors: Johnathan Velazquez Cruz (Universidad del Turabo), Ivia Moreno (Universidad del Turabo), María F. Barberena-arías (Universidad del Turabo), Sharon A. Cantrell (Universidad del Turabo)

Abstract

fungal community structure in soil and forest floor litter can help understand the factors that influence ecosystem recovery. This study is part of the Canopy Trimming Experiment 2 performed by the Luquillo LTER at El Verde Field Station. For this, three blocks (A, B and C) were selected, each with two plots of 20m x 20m, one plot was used for control and the other was subject to canopy opening and debris addition (Trim plus debris). Each plot was subdivided into 16 sub-plots, from which three sub-plots (5m x 5m) were randomly selected. In each subplot, litterbags with different mesh sizes were placed. This experimental design represents 3 blocks x 2 plots/block (1 trim+debris/ 1 control) x 3 subplots x 3 litterbag mesh sizes x 4 collecting times, for a total of 216 litterbags. A pool sample for each mesh size from the 3 subplots/per plot/time was obtained for DNA extraction and stored at -70C. DNA was extracted using Power Soil DNA Isolation kit from MoBio. The TRFLP technique was used to obtain the profiles of the fungal communities of each sample using the fungal ITS region. The diversity between samples was analyzed using NMDS and UPGMA Cluster analysis using the Dice and Bray-Curtis similarity index. Various types of fungal microorganisms were found in each of the mesh sized litterbags. The fungal communities found are potential decomposers in the forest floor.

Environmental Science Presenters: Yassin Dayekh, Shahrazad Santana Allende, Dilian J.

Mentor: Fuentes-Claudio, Lymari

Title: On the development of a metal bioremediation method using the combination of algae biomass and the sol-gel method.

Authors: Shahrazad Yassin (Universidad Metropolitana), Dilian J. Santana (Universidad Metropolitana), Marinel Rodríguez (Universidad Metropolitana), Lymari Fuentes- claudio, Phd (Universidad Metropolitana)

Abstract

Contamination with metals is a vast problem around the world. Many methods have been developed to address this issue. Among those methods, seaweeds has been considered as a suitable specie to be used for bioremediation of metals. Numerous species of seaweed has been object of research for these purposes with excellent results. It is important that the presence of the algae biomass in water bodies does not contribute to a larger environmental problem. Our investigation focusses on the ability of the immobilized Sargassum fluitans (S. fluitans) and Falkenbergia Rufolanosa (F. rufolanosa) algae biomasses for the removal of metals from aqueous solutions. This study will show the results obtained for the analysis of the intake of metals in controlled solutions when the biomass is suspended in the metal solution. These results are compare to the metal intake when the biomass is immobilized using the sol- gel technique. The effect of two experimental conditions were evaluated; pH and interaction time. A 203

difference in the intake of the metal were observed according to the experimental conditions. Metal concentration in solution was determined by atomic absorption spectroscopy.

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General Sciences 207

General Sciences Presenter: Bernard Vazquez, Faviola

Mentor: Suarez, Edu

Title: Effect of Covalent TAK1 Inhibitors on the Viability of Pancreatic, Renal and Colon Cancer Cells

Authors: Faviola Bernard (UPR-Ponce), William Singer (UT-Southwestern Medical Center), Deepak Gurbani (UT-Southwestern Medical Center), Kenneth Westover (UT-Southwestern Medical Center)

Abstract

Pancreatic, renal, and colon cancers are highly resistant to chemotherapy. A major contributor to this resistance is relatively high level of TGF-?-activated kinase-1 (TAK1) in the cancer cells, whose kinase activity leads to the suppression of pro-apoptotic signaling pathways. Molecules, which impede the binding developed as a strategy to overcome this resistance. They contain acrylamide groups that covalently attach to a cysteine in close proximity to the ATP-binding site and irreversibly inhibit the activity of TAK1. Reversible analogs lacking the acrylamide group have been synthesized for comparison. We have examined the effect of three covalent- and non-covalent-binding pairs of inhibitors on the viability of six cell lines derived from these cancers. In many instances, the viability of these cell lines in culture was inhibited 50% – 100% compared to untreated controls following a 72-hour treatment with 1?M concentrations of the drugs. The covalent inhibitors were generally more inhibitory than their non- covalent analogs. One of the three pairs of analogs reduced viability of every cell line to a greater extent than the other two. The IC50 values for this effect were determined by dose-response analysis, and the most potent covalent inhibitor often produced values lower than 100 nM. Future experiments will examine whether the reduction in vitality is a direct result of inhibition of the TAK1 signaling axis. Ultimately, these compounds may have potential as clinical candidates.

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General Sciences Presenter: Colón López, Yolimar

Mentor: Mateo, Zaira

Title: Obesity induces changes in the number of Astrocytes with high fat diet in mice Striatum.

Authors: Yolimar Colón López (Pontifical Catholic University of Puerto Rico in Ponce), Zaira Mateo (Ponce Health Sciences University), Yahurio Yamamura (Ponce Research Institute), Caroline Appleyard, Gladys Chompre

Abstract

Obesity is one of the main health concerns in our society due to the implications associated with depression and cognitive disorder. Studies using mouse models fed with high fat diet (HFD) demonstrate plasticity-related changes in the reward circuitry are associated with depressive-like phenotypes. Clinical studies done human subjects with severe depression demonstrates that reorganization in the connectivity of the striatum contributes to depression episodes. Moreover, recent work demonstrates that immune system plays an important role in depressive disorder. In fact, HFD increases circulating pro-inflammatory cytokines release from microglial cells resulting in neuroinflammation. Studies done in our laboratory found increase levels of Liposaccharides and Leptin in the blood from animals fed with High Fat Diet (HFD) which also showed depressive like syndrome. However, due to the close relation between microglial cells and astrocytes, both are link to be important contributors of the neuroinflammatory mechanisms. The aim of this project we will be to examine the number of glial fibrillary acidic protein (GFAP) positive astrocytes between HFD and LFD in dorsal striatum in the frontal cortex. Animals were fed with high HFD and LFD for 30 days. After behavior, animals were sacrifice and brain was removing. The brain was cut in three sections using rat brain matrix. Rostral, mid, and caudal brain sections were separated and embedded in paraffin. After embedding, various 8µm slices were prepare for hematoxylin and eosin staining from rostral section to identify the dorsal striatum for later immunohistochemistry analysis. PCUPR seed grant money; G12RR003050/G12MD007579; P20 GM103475-14.

209

General Sciences Presenter: Martínez Resto, Zulmari

Mentor: Chiesa, Ricardo

Title: Efectos ansioliticos de extracto orgánico de algas pardas de las costas de Puerto Rico en comportamiento relacionado a ansiedad en Drosophila Melanogaster

Authors: Zulmari Martinez Resto (UPR-Cayey), Keysh Mejias Martinez (UPR-Cayey), Grisel Robles Del Valle (UPR-Cayey), Anamaris Torres Sanchez (UPR-Cayey), Lee J. Algarin Sepulveda (UPR-Cayey), Ricardo Chiesa Chiesa (UPR-Cayey)

Abstract

La naturaleza tiene una gran diversidad de organismos con el potencial para estudiar sus compuestos bioactivos. Si nos enfocamos en la vida acuática, encontramos que las algas son organismos poco estudiados pero esto no opaca la gran capacidad que podrían tener para desarrollarse como fármacos en diversas áreas. Por consiguiente, la hipótesis del proyecto es que los extractos orgánicos y proteicos de algas pardas nativas de Puerto Rico disminuyen comportamientos de ansiedad. Para realizar las extracciones orgánicas se utilizaron dos géneros de algas Sargassum y Stypopodium, las cuales fueron recolectadas en las costas de Puerto Rico. Los efectos ansiolíticos de los extractos fueron estudiados en un modelo ansiogénico de Drosophila melanogaster. Para crear un comportamiento de ansiedad en Drosophila se utilizó el paradigma de Open Field Arena (OFA). Al validar el paradigma se demostró que Drosophila tiene fobia a estar en el centro del OFA, y la fobia es un comportamiento de ansiedad. Para poder utilizar los extractos orgánicos estos fueron disueltos en Sulfóxido de Dimetilo (DMSO), y luego se realizaron ensayos de toxicidad en los que se descartó la toxicidad del DMSO y del extracto crudo. Para realizar los ensayos conductuales, se colocó 1ml del extracto crudo en 5ml de agua y esta solución fue vertida en 1.8g de comida. Las moscas adultas fueron colocadas en el tubo preparado con extracto hasta que se observó una cantidad considerable de larvas, luego las adultas fueron retiradas del tubo y las larvas emergentes fueron las utilizadas para el ensayo conductual. Los ensayos conductuales fueron grabados con una cámara de video para poder cuantificar los resultados. Luego de realizar ambos ensayos conductuales (moscas expuestas o no al extracto) se realizó una comparación de los resultados en los que se muestra una reducción en el comportamiento de ansiedad en las moscas que crecieron en la comida con extracto. En conclusión, con los resultados preliminares obtenidos podemos decir que los extractos orgánicos de Sargassum tienen efectos ansiolíticos en un modelo de ansiedad de Drosophila melanogaster.

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General Sciences Presenter: Mendez Vazquez, Erika J.

Mentor: Mateo, Zaira

Title: Effect of Acute Sucralose Exposure on Dopamine Levels in Zebrafish Brain

Authors: Erika Mendez Vazquez (PUCPR), Zaira Mateo Mayol (PUCPR)

Abstract

Sucralose is a non-nutritive sweetener used in small amounts to reduce caloric intake while sustaining the desired taste in many food products. The derived products from its metabolism have been shown to have degenerative effects on nerve cells. Studies with crustaceans showed alterations in swimming behavior, suggesting potential neurotoxic effects in aquatic animals. Zebrafish is widely used due to its physiological and genetic homology to humans allowing the effective modeling of neurotransmitter systems and neurobehavioral disorders. Therefore to determine a potential effect of sucralose in neurotransmitter production a High Performance Liquid Chromatography (HPLC) method was used to detect changes in zebrafish brain dopamine levels following 48h acute sucralose treatment. After sucralose exposure, the fish brain was removed and homogenized according to standard procedures. Homogenates were centrifuged at 10,000 rpm for 10min; supernatants were collected, neutralized to pH 6 and then analyzed in the HPLC. The chromatographic system uses a reversed-phase C18; the mobile phase consisted of acetonitrile and tetrahydrofuran at a ratio of 94:3.5:0.7 at a flow rate of 1.0 ml/min. Currently, preliminary results and experiments are under analysis.

General Sciences Presenter: Mercado Velez, Karla I

Mentor: Ramos-Ortolaza, Dinah

Title: Can Estrogen Protect Female Rats against Negative Impact of Morphine Dependence?

Authors: Karla I Mercado Velez (Pontifical Catholic University of Puerto Rico)

Abstract

Addiction to opiates such as morphine is a major public health concern. Morphine is an analgesic drug used to treat chronic pain. Its long term use can induce dependence, which can lead to a higher risk of developing anxiety disorders. Our primary question was: Can morphine dependence cause anxiety disorders? We decided to observe sex differences as well, based on previous studies showing differences in drug dependence and anxiety disorders incidence between males and females. To answer 211

the question, male and female Sprague Dawley rats (60 days old) were injected with morphine (s.c., 5-50 mg/kg) every 12 hours for 10 consecutive days to induce dependence. Ninety six hours after the last morphine injection, when no signs of withdrawal were observed, rats were trained on fear conditioning and extinction. Results showed that chronic morphine administration had no effect on fear conditioning. That is, all animals learned that they would receive a foot shock after a tone, so they froze whenever the tone was presented to them. Interestingly, during the extinction, when the animals were presented with the tone, without the foot shock, morphine treated female rats decreased their fear over time, while males continued to show fear, even in the absence of the foot shock. This effect persisted 24 hours after extinction. These results suggest that morphine dependent female rats learned that the tone no longer predicted a foot shock. Meanwhile, morphine dependent male rats did not learn, which explains why their fear was still high. Based on these results we proposed that the behavioral differences observed were due to differences in sex hormones. Therefore, we decided to see if there were changes in levels of estrogen receptors in the brain of these animals. We saw an increase in estrogen receptor alpha in the Nucleus accumbens of morphine dependent rats, which was significantly higher in females than males. Since previous studies have suggested that estrogen is a neuroprotector, we believe that higher estrogen receptor activity in the brain is protecting female rats from the negative effects of morphine. To understand better what happened with morphine dependent male rats, we will study the regulation of MAPK signaling cascades in the hippocampus. Based on a previous study, decreased activation of specific members of this signaling cascade is associated with anxiety and depression. Therefore, it is possible that the persistent fear observed in morphine dependent male rats is due to dysregulation of MAPK signaling cascades.

General Sciences Presenter: Morales García, Yahaira

Mentor: Perez-Velez, Mariel E.

Title: Elevated potential for EMA in egg products as a result of production shortages due to highly pathogenic avian influenza.

Authors: Yahaira Morales García (Universidad del Este), Aisha Ramos Adamas (Universidad del Este), Dr. Karen Everstine (Food Protection and Defense Institute)

Abstract

There is no statutory definition of economically motivated adulteration (EMA) of comestibles or food ingredients, which are generally considered a subset of food fraud. Although the majority of food fraud incidents do not pose a public health threat, there have been cases that have resulted in actual or potential public health risks. Risks from other types of fraudulent foods are not as well-documented and may be less immediate or may never be known. A common form of EMA, undeclared substitution with alternative and replacements ingredients, is one of the most concerning adulteration because of 212

allergen labeling requirements risking the consumer life. The objective of this study is to determine the EMA incidents of egg products and shell eggs during December 2014 to July 2015 produced by the high pathogenic avian influenza outbreak. The program database available for EMA incidents, food shield, are going to help us find the multiple cases in adulterated products. The food shield web based tools that enhance threat prevention, response, risk management, communication and asset coordination; as well as public education. Some of the earliest reported cases of food adulteration have shown that some industries sold adulterated shell eggs with biological risk to the population and manufacturing companies. The beginning of these incidents starts the new era; the food fraud in the egg production. Several types of EMA incidents have been reported in the egg industry including mislabeling, intentional distribution of contaminated product, substitution with non-food grade substance and artificial enhancement. Although the avian influenza outbreak had been regulated by taking action and rationing the consumption, selling and exportation; limiting the shell eggs and products egg for priority use purposes. Regulatory agencies and trade organization had ensured the good quality of the exports and imports of shell egg and egg product. Prevention and detection of EMA cannot depend on traditional food safety strategies to be aggressive and well planned to create an effective approach to prevent adulterated incidents. Comprehensive food protection and defense, as outlined by the Food Safety and Modernization Act, will require innovative methods for targeting crucial resources towards the adulteration of high risk shell eggs and egg products. This preliminary study could lead to develop novels, fast and sensible methods of detection for these specifics products and apply it to the federal regulatory requirements for food industries.

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Geosciences

215

Geosciences Presenter: Hernández González, Paola N.

Mentor: Santos, Hernan

Title: Paleobotany of the San Sebastián Formation exposed in the Guatemala River: taxonomy of plants using leaf physiognomy

Authors: Paola Nanichy Hernández González (University of Puerto Rico at Mayagüez)

Abstract

Three paleobotanical sites were identified along the Guatemala River in San Sebastián, Puerto Rico. Rock samples and fossils of the area were collected and curated. 33 specimens of fossil plant remains were properly examined, classified morphologically and analyzed in a sequence stratigraphy context. 15 different morphotypes of fossil leaves, 1 seed and two different root systems have been found along the Guatemala River exposures of the San Sebastián Formation. Also herbivory signs and other leaf damage features are reported in this study. Based in the geologic and paleobotanic settings, the paleoenvironmental implications of the paleoflora present in the Guatemala Group suggest estuarine depositional environments with marine influence, typical of transgressive system tracts preservation.

Geosciences Presenter: Santiago Torres, Alejandra

Mentor: Ramirez, Wilson

Title: Morphology, Texture, and Composition of Ooids of the Little Bahama Bank Platform

Authors: Alejandra Santiago Torres (University of Puerto Rico at Mayagüez)

Abstract

The carbonate platform of Little Bahama Bank is known for having oolitic shoals whose geomorphology varies with factors such as hydrodynamics. By studying Holocene ooids from four oolitic shoals that show different physical factors, new insights can be learned about how the physical parameters of the environment of the shoals affect the morphology, texture, and composition of the ooids. This investigation provides insights such as trends in mineralogy, grain size distribution, composition, crust thickness, and relative diameter of the ooids present between localities. The information available from these Holocene ooids can be used to comprehend the character of ancient oolitic shoals that are often very good reservoirs.

216

Geosciences Presenter: Vélez Rosado, Kevin I

Mentor: Santos, Hernan

Title: Vertebrate Paleontology and Paleoenvironmental Analysis in the Yanigua-Los Haitises Formations, Dominican Republic

Authors: Kevin Ian Vélez Rosado, Hernán Santos Mercado, Jorge Vélez-juarbe

Abstract

During the Cenozoic the Greater Antilles was a place with ecologic niches occupied by predators such as crocodiles. Dispersal of terrestrial mammals from South America through GAARlandia was a hypothesis proposed 11 years ago, and may be the reason as well that these reptiles are found in the geologic record of the Greater Antilles. Here, we properly describe crocodylian remains from the Yanigua-Los Haitises Fm. in the Dominican Republic. Different skeletal elements were collected from a single stratigraphic horizon, including fragmentary rostrum, skull and mandibles, dorsal and caudal vertebrae, fragmentary teeth, an ilium, and a partially preserved rib. Characteristics of the cranium and postcranium show that the material belongs to a new genus and species of gharial (Gavialoidea), closely related to the Gryposuchinae from the Oligocene and Neogene of the Greater Antilles and South America. The occurrence of a gharial in the Dominican Republic allows for new insights about the paleobiogeography and paleoenvironment of this group during the late Miocene to early Pliocene. The geologic settings where the Dominican gharial was collected reveals that this species lived in fluvial or near brackish water environments represented as minor river deposits during the Messinian to middle Zanclean. This setting was formed during relative changes of sea level creating hiatuses or sequence boundaries due to a Falling Stage System Track (FSST) that can be seen in the outcrop as regressions- transgressions and are consistent with the depositional models mentioned by earlier workers.

217

Industrial Pharmacy

219

Industrial Pharmacy Presenter: Sang-Laboy, Brian

Mentor: Perez-Jimenez, Jose R.

Title: Biopospecting Antimicrobial Aactivity from the San Juan Bay Estuary

Authors: Brian Sang-laboy (Universidad del Turabo), Abisrael Morales-feliciano (Universidad del Turabo), Jose R. Perez-jimenez (Universidad del Turabo)

Abstract

This study analyzed the biodiversity present in the Bay San Juan Estuary is a system of interconnected lagoon and channels that flow into the Bay. Throughout this ecosystem, the water column receives discharges from natural sites, houses, and commercials facilities that have compromised its quality. Thus, the estuarine system harbors challenges among diverse microbes. Our objective is to isolate bacteria from the San Juan Bay Estuary that exhibits antimicrobial activity. Water samples were cultivated in Tryptic Soy Agar plates aiming for dense cultures. Bacterial exhibiting inhibition zones were isolated and characterized according to morphology, selected biochemical tests, and 16S rDNA sequencing. Antimicrobial activity was demonstrated by inhibition zone in concurrent cultivation with reference stains. The collections of forty-nine bacteria were isolated with antimicrobial activity. However, these are halotolerant stains, Gram-positive rods, producing catalase, and unable to reduce nitrate. Most of the antimicrobial activity was detected against Pseudomonas putida, Enterococcus raffinosus, Staphylococcus epidermidis, Bacillus subtilis, and Lysobacter antibioticus. The twenty-six isolated were able to inhibit the growth of four reference stains. Sequencing of the 16S rDNA demonstrated the presence of three Alcaligenes strains, Bacillus sp., Achromobacter sp. and Psedomonas sp. The 16S rDNA is being sequenced for additional bioprospects. The potencial of these microorganisms to produce useful antimicrobial compounds is great and must be better explored

221

Life/Biological Sciences

223

Life/Biological Sciences Presenter: Agosto Guzman, Genesis L.

Mentor: Arroyo-Cruz, Luz V.

Title: Antimicrobial activity of Annona muricata, Ananas comosus and Carica papaya against Enterobacter aerogenes

Authors: Genesis L. Agosto Guzman (Universidad del Turabo)

Abstract

Enterobacter aerogenes is a gram negative bacteria that causes nosocomial infections in immunosuppressed patients. This bacteria has mechanisms of antibiotic resistance, making it difficult to treat infections caused by E. aerogenes. New drugs are needed to infections with antibiotic-resistant strains. Carica papaya plants, Ananas comosus and Annona muricata has been shown to have antimicrobial properties against pathogenic bacterium, however none of these plants have been tested against E. aerogenes. This research aims to find antimicrobial properties in the leaves of the plants C. papaya, A. muricata and A. comosus against the microorganism E. aerogenes, to increase awareness of existing antibiotics and natural remedies. The alcohol extraction method was used to obtain the extract from the leaves of each species. The leaves were macerated and diluted in 250ml of alcohol at 100% in a lidded jar for 72hrs at room temperature. The extracts were filtered by vacuum filtration to remove impurities and were concentrated by evaporation for 48 hrs. The Kirby-Bauer method was used for the antibiosis. The culture of E. aerogenes used was provided by the Universidad del Turabo Centro de Barceloneta. Statistical student t-test (less or equal than 0.98) and antimicrobial activity of the extracts used was found, in turn E. aerogenes resistance against ampicillin was also demonstrated. It is recommended in the future to do biochemical tests to identify chemicals responsible for the antimicrobial activity found in leaves of plants used.

224

Life/Biological Sciences Presenter: Alvarado Rodríguez, Edrick J.

Mentor: Rios Velazquez, Carlos

Title: Comparing and Searching for UV-C Radiation Resistant Bioprospects from Puerto Rico Soils

Authors: Edrick J. Alvarado Rodríguez (University of Puerto Rico at Mayaguez), Carlos Ríos Velázquez (University of Puerto Rico at Mayaguez)

Abstract

There are three different types of Ultraviolet (UV) radiation: type-A, B and C. C-type UV radiation is the most harmful, but is mostly blocked by the Earth's atmospheric contents. The higher above sea level the more of this type of radiation is received, for there is less material for it to interact with. Exposure to these types of radiation has increased throughout the last decade due to atmospheric complications such as ozone depletion and atmospheric optical thickness decreases. This increase of UV radiation causes many health complications, for it is harmful and even lethal in large doses. The biomedical challenge this problem creates can be fought through different methods of bioremediation and protection strategies. To date we are capable of using UV radiation resistant microorganisms as a model to understand UV-resistance and develop innovative methods to help confront this situation. The objective of this research is to find cultivatable bacteria capable of tolerating ultraviolet radiation and determine their degree of resistance. The radiation resistant bioprospects were isolated from different environments of Puerto Rico by irradiating soil samples from the sampling sites with C-type ultraviolet radiation. To determine the extent of resistance of the bacteria they were exposed to UV radiation from 15 up to 120 seconds and then grown at 37ºC for 24 hours, covered in aluminum foil to avoid DNA repair by photo-reactivation. The survival percentages per dose of radiation were calculated and plotted. After processing 6 different soil samples from Cerro Punta, the highest peak in Puerto Rico, 12 UV-C resistant bioprospects were isolated. Also, three gram-positive bacilli previously isolates from the Cabo Rojo Salterns had a higher survival percentage when compared to the control Escherichia coli. The highest survival rate was 10%, followed by 1.83% for moderate and 0.86% as the lowest survival rate. A total of 11 isolates from Cerro Punta have been tested and 2 of these isolates have shown moderate resistance. It has also been observed that many of the isolates are capable of producing different pigmentation that depends on the culture media used. We are in the process of determining the effect of the different pigmentation in UV-C resistance, and compare these data with non-pigmented and endospore-producing bacteria isolated from the sampling sites. The bacteria found are potential bioprospects to search for gene(s) or physiological strategies responsible for their resistance and to use as biological models in the fight against UV radiation induced damage.

225

Life/Biological Sciences Presenter: Alvarado Vega, Jusilmarie

Mentor: Chompre, Gladys

Title: Primary Rat astrocytes supernatants showed the presence of HIV-Nef associated with the exosomal pathway

Authors: Jusilmarie Alvarado Vega (PCUPR)

Abstract

Primary Rat astrocytes supernatants showed the presence of HIV-Nef associated with the exosomal pathway Jusilmarie Alvarado1, Richard Noel Jr2, and Gladys Chompré1 Sciences University, Ponce Research Institute, Ponce, PR Pontifical Catholic University of Puerto Rico, Biology Department, and Ponce Health HIV infection is associated with a spectrum of neurological disorders and opportunistic infections in the central nervous system (CNS). Some cells in the brain, particularly astrocytes, are susceptible to HIV infection but will only express early HIV proteins such as the viral Nef protein. Previous studies in post-mortem brain from neuroAIDS patients found HIV-1 Nef expression in the astrocytes. We have shown that infusion of astrocytes expressing HIV-1 Nef into the rat hippocampus produces learning impairment. Concurrent studies of those astrocytes in vitro showed that the cells secrete HIV-1 Nef protein. The hypothesis is that HIV-1 Nef in the astrocytes is secreted within exosomes in our cultures. Primary rat astrocytes are cultured in exosome-free medium for a week prior to transfection with a pcDNA3.1 HIV-1 Nef expression plasmid and incubated for 48 hours. Supernatants were removed from the cultures and centrifuge to remove the cell debris and cells were collected in parallel for comparison. Cell lysates and cell-free supernatants were used to perform western blot to assess the presence of HIV-1 Nef protein inside and outside the astrocytes, respectively. Result showed the presence of HIV-1 Nef both intracellularly and extracellularly. Future directions in this project will include assessment of exosomal markers such as actin and CD63. Knowing the mechanism by which HIV- 1 Nef is secreted will help us to understand HIV neuropathogenesis in future studies and to elucidate the manner by which Nef acts as a neurotoxin in vivo. Support: Ponce Health Sciences University, Ponce Research Institute MAGIC laboratory (grant number MD007579)

226

Life/Biological Sciences Presenters: Alvarez-Colón, Nelson I. Vázquez Ramos, Wilmarie

Mentor: Avalos, Javier

Title: Wireless Bacteria Nanosensor Based on Carbon Materials

Authors: Nelson I. Alvarez-colón (Department of Biology, University of Puerto Rico - Río Piedras), Wilmarie Vázquez-ramos (Department of Biology, University of Puerto Rico - Bayamón), Javier Avalos (Department of Physics, University of Puerto Rico - Bayamón), Gerardo Morell (Department of Physics, University of Puerto Rico- Río Piedras), Brad Weiner (Department of Chemistry, University of Puerto Rico - Río Piedras)

Abstract

Hospital and health communities need a more effective electronic bio-interface to better reduce or eliminate bacterial threat. The biosensor industry fabricates solid devices that are not suitable for biological surfaces because of its morphological irregularities, for that reason the sensor must possess the ability to attach conformably to such surfaces. In order to solve this problem, we propose a flexible resonance wireless sensor that will detect bacteria and their population density. The bio-sensor consists of a printed radiofrequency wireless sensor made of gold, to which graphene and peptides were incorporated. This part of the sensor is attached to a Kapton substrate; this device will neither work with any batteries nor use wire to transfer the information from the bio-sensor to another device. The Kapton based substrate will allow the biotransfer of the sensors onto the biomaterials in a simple and efficient manner. Preliminary results have shown that when exposing the nano and microcrystalline diamond to bacteria a change in resistivity of the material is observed, this will produce changes in the radiofrequency response. This innovative platform to build nanosensors for biomedical applications will improve bioelectronics for interface monitoring.

Life/Biological Sciences Presenter: Arias-Delfi, Yvette M.

Mentor: Suarez, Edu

Title: The Role of REM Sleep in the Development of PTSD Using a Rodent Model

Authors: Yvette Marie Arias Delfi (University of Puerto Rico at Ponce), James Delorme (University of Michigan), Gina Poe (University of Michigan) 227

Abstract

Sleep disturbances resulting from an acute trauma predict the development of posttraumatic stress disorder (PTSD) symptoms. Sleep abnormalities can aggravate PTSD and may result in failure of extinction memory, allowing fear to persist. Currently, the electrophysiological properties of sleep that are associated with trauma are not well understood. Rapid eye moment (REM) sleep plays a critical role in memory consolidation and emotional regulation but it may be maladaptive in those experiencing PTSD. We hypothesize that normal, adaptive REM sleep following a traumatic event will lessen the severity of a PTSD-like phenotype. Male Sprague Dawley rats were REM sleep deprived prior to (n=6) or after (n=6) a single prolonged stress (SPS) protocol (three acute stressors followed by a 7-day isolation period) to develop a PTSD-like phenotype, and to assess the contribution of sleep disruption to phenotype development. We evaluated freezing levels on a fear-associated memory test to assess the severity of the PTSD-like phenotype in the two sleep deprivation groups compared with controls who never experienced the trauma (n=6) and traumatized rats who were never sleep deprived (n=6). Interestingly, sleep deprivation after the acute phase of SPS and prior to the 7 day isolation period ameliorated the PTSD like symptom of impaired extinction recall a week later. The data suggests that REM sleep deprivation after a traumatic event reduces PTSD-like phenotype, and that sleep disruption before the trauma exposure did not have a similar effect in rescuing the animals from the posttraumatic disorder symptoms. Our findings, preventing possibly maladaptive sleep following trauma, and timing sleep to adaptive windows normalize later fear extinction abilities. This may be beneficial as part of a treatment for PTSD and other stress associated disorders.

Life/Biological Sciences Presenter: Arroyo, Gerardo A.

Mentor: Suarez-Martinez, Edu

Title: Effects of Resveratrol in CXCR4 Expression and Apoptotic Markers in Normal Cell Lines Derived from a Breast Cancer Patient

Authors: Gerardo Arroyo (University of Puerto Rico at Ponce), Kevin Muñoz-forti (Pontificia Universidad Católica), Alexandra Maldonado (University of Puerto Rico at Ponce), Sharylin Almodóvar (University of Colorado Denver - Anschutz Medical Campus), Edu Suarez (University of Puerto Rico at Ponce), Abigail Ruiz (University of Puerto Rico at Ponce)

Abstract

The cellular and molecular environment of normal cells from breast cancer patients are particulary understood. Chemokines and their receptors have roles in cellular proliferation, metastasis, and angiogenesis. Specifically, CXCR4, a G-protein coupled receptor is expressed in high levels in breast neoplastic tissues and in low levels in normal breast tissue. CXCR4 expression may induce proliferation, 228

migration, invasion and angiogenesis. Recent studies have identify resveratrol (a natural polyphenol) to play a role on inflammation, apoptosis, and neovascularization. Due to limited scientific literature on the effects of resveratrol on CXCR4, the biological process in which both coincide, (inflammation, apoptosis, and neovascularization), and the potential use of resveratrol, as a therapeutic agent in cancer, we studied the effect of this polyphenol on CXCR4. In addition, we explored the effects on the apoptosis mediator Bax. We hypothesized that resveratrol increases the expression of CXCR4 in normal cells from a breast cancer patient. We determined the effects of resveratrol at concentrations of 25, 50, 100, 200 µM after 24 hours of treatment in the protein levels of CXCR4 and Bax-2 by western blot using CCD1097 a fibroblastic cell line, derived from normal skin from the breast of a patient undergoing biopsy of a grade III infiltrating ductal carcinoma. Our preliminary results indicate that higher doses increased expression of CXCR4 in a dose-dependent compared to control vehicle treated cells. Similarly, Bax expression increased in all treated cells but in a non-dependent dose manner. These results may suggest that resveratrol have an effect on CXCR4 protein levels, leading to an increase in proliferation in normal cells from cancer patients. As reported, at lower doses resveratrol may have antiapoptotic effects and at higher doses may induce apoptosis. Resveratrol may prompt for clearance of cancer cells using different pathways but additional experiments will be necessary to identify the exact mechanism of action. Additional experiments are underway to identify the proliferative effects of resveratrol including apoptosis (caspases) and inflammation (TNF-? and SOD-2).

Life/Biological Sciences Presenter: Asencio Quiñones, Yanelle I

Mentor: Fuentes-Claudio, Lymari

Title: Evaluating Plastocyanin from spinach as an antitumor agent

Authors: Dr. Lymari Fuentes-claudio (Universidad Metropolitana)

Abstract

The phytochemical Plastocyanin (Pc) is a protein present in plants and has been extensively studied in relation to its function as an electron transporter between the photosystems during the photosynthesis process. Due to its relation to the bacterial protein Azurin, we wanted to know if like Azurin, Pc also has antitumor properties. Our preliminary results indicated that Pc has an inhibitory effect on the proliferation of the human breast adenocarcinoma cell line MDA-MB231. A decrease in the number of cells were observed when the protein interact with the cell culture. This change is related to the concentration of the protein used during the treatment. Although, further studies are necessary we can say that plastocyanin have the potential to act as an antineoplastic agent.

229

Life/Biological Sciences Presenter: Báez Bravo, Gabriela A.

Mentor: Baerga-Ortiz, Abel

Title: Outer membrane vesicles from E. coli IHE3034 induce megalocytosis in eukaryotic cells

Authors: Gabriela A. Báez Bravo (University of Puerto Rico, Río Piedras), Yermary Morales Lozada (University of Puerto Rico, Río Piedras), Ramón Gomez Moreno (University of Puerto Rico, Medical Sciences Campus), Abel Baerga Ortiz (University of Puerto Rico, Medical Sciences Campus)

Abstract

E. coli clinical isolate IHE3034 (pks+) has been shown to induce megalocytosis in eukaryotic cells. The pks genomic island encodes for the biosynthesis of a genotoxin known as colibactin. Colibactin is presumably made in the bacterial cytosol and transported to the periplasmic space by a transporter encoded in ClbM. However, it is not known how the compound gets from the periplasm to the infected cell. In this project, we explore the possibility that the bacteria are using outer membrane vesicles (OMVs) as a transport mechanism for colibactin. OMVs provide an insoluble secretion pathway for gram-negative bacteria and are responsible for the release of outer membrane and periplasm out of the cell. In addition, these vesicles can travel far away from the cell and convey biological functions on to other cells. We incubated HeLa cells and exposed them to OMVs from various E. coli strains: IHE3034 (pks+) and DH10B (pks-). Our results show megalocytosis in HeLa cells when exposed to OMVs from IHE3034, but not when exposed to OMVs from DH10B.

Life/Biological Sciences Presenters: Barrios Rosario, Nicole Rivera Baez, Nitza

Mentor: Vargas, Maria

Title: Inhibitory effects of Pimpinella ansium and Citrus limon oils in presence of Aspergillus Niger

Authors: Maria M. Vargas (UPR- Mayaguez), Nitza Rivera (UPR- Mayaguez), Nicole Barrios (UPR- Mayaguez) 230

Abstract

Based on the characteristics from essentials oils, their antifungal and antiseptic properties that had been founded in recent literature, it was decided to use Pimpinella ansium and Citrus limon oils to observed the inhibitory effects in the ascomycete mold Aspergillus niger. The first method was the Agar Diffusion using almond oil as a control and diluent. The second method was Well Diffused Assay in which some wells were made for both oils at 1:1, 1:2 and 1:3 concentrations. The objective was to analyze the individual and synergism effect of both oils in the presence of A. niger. The effects were observed during a 10 day period. For the first method, Pimpinella ansium in the 1:1 concentration, diluted in almond oil, was very effective inhibiting growth. Citrus limon inhibits growth by itself, but diluted with almond oil it did not had the same effect. Synergism effect creates 2 inhibition zones as concentric rings. For the second method, Pimpinella ansium inhibited growth aggressively, instead of Citrus limon effect that was of short duration. Synergist effect demonstrated that Pimpinella ansium had a better effect at 3:1 concentration. In general, Pimpinella ansium had the best effect of inhibiting this mold. Citrus limon had less or non effect. In cases of A.niger diseases, therapeutic treatment with essentials oils can be a viable treatment. This is a preliminary study and it will continue further in the future.

Life/Biological Sciences Presenters: Betancourt Ponce, Mayra A. De Jesús Colón, Charlotte M.

Mentor: Garcia Arraras, Jose

Title: Characterization of H. glaberrima primary muscle cell cultures as a tool to screen drugs that mediate regenerative responses

Authors: Mayra A. Betancourt Ponce (University of Puerto Rico, Río Piedras Campus), Charlotte M. De Jesús Colón (University of Puerto Rico, Río Piedras Campus), Christian Castro (University of Puerto Rico, Río Piedras Campus), José E. García Arrarás (University of Puerto Rico, Río Piedras Campus)

Abstract

Echinoderms are recognized for their impressive regenerative skills. Two main steps for muscle regeneration in these animals have been documented: dedifferentiation and myogenesis. In dedifferentiation, structures known as "spindle-like structures" (SLS), form in muscle cells as they eliminate their contractile apparatus. This is followed by nuclear activation, where the cell prepares for proliferation and then redifferentiation. Myogenesis consists of the formation of the new muscle cells. Sea cucumbers have the most developed musculature system of the echinoderms and their muscles are easy to extract and manipulate, thus they have been subject of study for muscle regeneration. In our model system, the sea cucumber Holothuria glaberrima, the process of muscle dedifferentiation begins 231

soon after the injury to the muscle bundles, and their restoration, continues up to 2-3 weeks. We have now characterized muscles cells in a primary cell culture and describe here their changes in number, morphology and composition. Five different morphologies were identified: round (big and small), fiber- like, fusiform (thin at the ends and bigger in the middle), and conglomerates (formed groups). To be able to characterize the culture, changes in and number of morphologies present are observed throughout time. These cell cultures can be manipulated with different drugs and substrata. A treatment with Efavirenz drug was performed to see its effect in an in vitro study of the muscle cells of the species. This drug acts as a non-nucleoside reverse transcriptase inhibitor. The cells were exposed to different concentrations of the drug and observed throughout a period of time. They were then treated with FITC Phalloidin and DAPI to mark the actin filaments in the cytoplasm and the nuclei of the cells, respectively, followed by data analysis. Concentrations of 0.0016M and 0.00016M were found to have a strong effect on cellular morphology. These results suggest that cell cultures might be of great use to decipher the process of cell dedifferentiation in echinoderms.

Life/Biological Sciences Presenter: Boria Gonzalez, Fernando

Mentor: Domenech, Maribella

Title: Mesenchymal –driven hedgehog signaling promo tes tumor cell growth in triple negative breast cancer

Authors: Maribella Domenech (Assitant Professor), Karla P. Ramos (Undergraduate researcher), Wandaliz Torres (Professor), Fernando Boria (Undergraduate researcher)

Abstract

Triple negative breast cancer (TNBC) is a clinical therapeutic challenge due to the lack of receptors for estrogen, progesterone, and human epidermal growth factor receptor2 which limits treatment options to chemotherapy and radiation. With current standard therapy less than 30% will survive the 5-year remission rate, especially Hispanic and African-American women where TNBC is more frequent and has the lowest (nowledge regarding the role of mesenchymal cells derived from various sources in the development, progression and response to therapy of TNBC and other cancers. Here we developed a tumor-mesenchyme in vitro model to evaluate the role of mesenchymal cells from different sources in the proliferative potential of breast cancer cells using custom designed multiwell array. Using qRT-PCR we confirmed up-regulation of canonical Hh target genes Gli1 and Patch1 in TGF-b treated NIH3t3 fibroblasts and Hs578t (epithelial–mesenchymal transition). Paracrine Hh signaling significantly increased proliferation rates in 184B5 cell line (normal human epithelial breast cell line) and MDA-MB-468 (TNBC cell line). Cells that undergo EMT promoted cell growth at higher rates than myofibroblasts. SHH treatment alone (without TGF-b-pre-treatment) had an inhibitory effect in the proliferation rates 232

of the adjacent epithelium compartment. Computational analysis of Hh target genes in basal breast cancers show high correlation among TNBC patients and mesenchymal driven Hh signaling. Thus, mesenchymal component can modulate tumor growth behavior induced by Hh signaling.

Life/Biological Sciences Presenter: Calzada Jorge, Natalia S.

Mentor: Washington, A. Valance

Title: Use of Ferrocene-Estradiol as a Promising Treatment for Breast Cancer Cells

Authors: Anthony Washington (Universidad de Puerto Rico, Recinto de Río Piedras, Departamento de Biología), Liz Hernández-matías (Universidad de Puerto Rico, Recinto de Río Piedras, Departamento de Biología), Natalia Calzada Jorge (Universidad de Puerto Rico, Recinto de Río Piedras, Departamento de Biología), Enrique Meléndez-martínez (Universidad de Puerto Rico, Recinto de Mayagüez, Departamento de Química), José Ramírez (Universidad de Puerto Rico, Recinto de Mayagüez, Departamento de Química), Julyanas Ramírez Rodríguez (Universidad de Puerto Rico, Recinto de Río Piedras, Departamento de Biología)

Abstract

Transition metals such as cisplatin, are effective at killing certain types of cancer cells. This drug can crosslink DNA, affecting DNA synthesis and ultimately leading to cell apoptosis or necrosis. However, cisplatin can affect DNA synthesis of cancer cells as well as healthy cells because of its poor selectivity. To overcome cisplatin's poor selectivity, this research attempts to identify if other transitional metals compounds such as ferrocene can induce mortality on breast cancer cells without affecting healthy cells. In order to confer selectivity to ferrocene, the hormone estradiol, which is present in high concentrations in breast cancer, has been ligated to ferrocene. To date, this new compound, ferrocene- estradiol (FES) has shown to induce mortality of MDA-231 breast cancer cell line and when comparing it to ferrocene it was found to be more effective. Further on, we carried out cell cycle experiments to determine at what stage of the cell cycle FE induced mortality in the MDA-231 cells. Results showed that cells were arrested in the S phase; further experiments will be done to confirm these results in a period of 24 hours. These results might be an indicator of a better and more effective treatment when dealing with breast cancer.

233

Life/Biological Sciences Presenters: Caro Ortiz, Giovanni S. Garcia Pabon, Kenny

Mentor: Morell, Gerardo

Title: Biosensor prototype based on carbon nanotubes for the detection and treatment of HeLa cells

Authors: Giovanni S. Caro Ortiz (University of Puerto Rico-Río Piedras), Kenny Garcia Pabon (University of Puerto Rico-Río Piedras), Marcia Fernández (University of Puerto Rico-Río Piedras), Javier Avalos (University of Puerto Rico-Bayamón), Gerardo Morell (University of Puerto Rico-Río Piedras)

Abstract

The World Health Organization's Annual Report on Cancer indicates that, in 2008, 12.4 million new cases and 7.6 million deaths from cancer alone were recorded around the world. Some of the treatments for HeLa cancer cells include surgery, chemotherapy, radiation therapy as well as combinations of these. Though widely utilized, these treatments are not entirely effective as some cancer cells are resistant to their use. This prototype aims to create an effective alternative for the detection and therapy against this disease. Recently, with the advance of nanotechnology, we have synthesized new nanomaterials, which have various applications towards the detection and therapy of cancer. This wireless radio frequency sensor (RF) is based on carbon nanotubes (CNTs) to allow a timely detection of cancer cells and permit a selective destruction by thermal ablation (AT) due to the excitement of CNTs with harmless radiation of radio frequency (RF) and near infrared (NIR). The sensor is a gold resonant coil LRC circuit for wireless transmission and in its capacitive component CNTs and Gr are deposited and functionalized. The detection is based on a change in the detected RF signal with respect to that emitted by the sensor, when a cancer cell is present. Treatment will be administered through photothermal therapy, which will rely on the excitement of CNTs with NIR, CNTs will then absorb radiation and convert it into heat, which will also occur if they are excited with RF.

234

Life/Biological Sciences Presenter: Carrera-Martinez, Roberto

Mentor: Santos Flores, Carlos

Title: First record of earthworms on the Benhamiinae subfamily (Oligochaeta, Octochaetidae) in Puerto Rico

Authors: Roberto Carrera-martínez (University of Puerto Rico, Mayagüez Campus), Patricia Rodríguez-matos (University of Puerto Rico, Mayagüez Campus), Carlos Santos-flores (University of Puerto Rico, Mayagüez Campus)

Abstract

The earthworm fauna of Puerto Rico represents one of the best studied in the Caribbean, with a total of 18 native species. However, there are still vast areas of the Island that have never been surveyed, and potentially are home of species unknown to science. One of these zones are the rural areas in San German, where we carried a series of small surveys. We also surveyed the "experimental forest" of the Biology Building at the University of Puerto Rico, Mayagüez Campus. The rural samples from San German were collected in an abandoned guava plantation, with secondary forest growth and understory removal of weeds and bushes, and an area used to raise chickens and ducks. In San German, we found Pontoscolex corethrurus, P. cinthyae, Polypheretima enlongata and "Dichogaster" sp. 1, while in Mayaguez we found P. corethrurus, Eudrilus eugeniae and "Dichogaster" sp. 2. We present the first reports of "Dichogaster" in the main island of Puerto Rico, as two additional species (D. affinis and D. saliens) were previously reported from Vieques. In addition, this is the first earthworm collection conducted for the municipality of San German. Our current work is concentrated in the detailed study of these two "Dichogaster", as they show some characters that might represent species of Eutrigaster including the presence of a proventiculus in segment 5 and two gizzards on segment 6 and 7. Afterwards, we will identify the specimens down to species and assign a name if they are new to science, and produce a description with illustrations for publication. Together, Dichogaster and Eutrigaster count with more than 200 species distributed on the African continent, South and Central America and some islands of Caribbean, but their presence in Puerto Rico had never been confirmed before. These new reports confirm the need for more extensive earthworm surveys in previously unexplored areas on the Island to better understand the biodiversity of these ecologically important group of organisms.

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Life/Biological Sciences Presenter: Cintron Arroyo, Kevin

Mentor: Noel, Richard

Title: Genetic Modifiers of Cardiac Development in 22q11 DS Mouse Models

Authors: Kevin Cintron Arroyo (University of Puerto Rico in Ponce), Silvia Racedo (Albert Einstein University), Jonathan Chung (Albert Einstein University), Bernice Morrow (Albert Einstein University)

Abstract

Over 70% of patients with 22q11.2 Deletion Syndrome (22q11DS) have congenital heart defects. The prevalence and severity of these defects make it critical for us to strive to understand the underlying mechanism of the syndrome by elucidating the gene pathways that are involved in heart development, as their disruption may lead to congenital heart diseases (CHDs). TBX1 and CRKL, the main genes that have implicated in 22q11DS as responsible for patient CHDs, are required for normal development of the heart. It's been suggested that some genes located outside of the 22q11 deleted region can act as genetic modifiers of CHDs in the syndrome and may also be required for normal development of the heart. Three of these genes are NTRK3, WNT5A and ROR2. Mutations in WNT5A and ROR2 were identified in patients with CHDs and 22q11DS, while mutations in NTRK3 were identified in non- syndromic patients with CHDs. One of the overarching aims of this study is to test whether genetic modifiers of heart defects associated with the 22q11.2 deletion are the same genes as the genes that alter risk for heart defects in non-syndromic CHD patients. First, we must test where these three genes are expressed in normal developing embryonic hearts and we have decided to use the mouse as a model to do this. Digoxigenin-labeled RNA probes for Ntrk3, Wnt5a and Ror2 were designed and used for in situ hybridization in order to observe the expression of these genes in mouse embryos specifically in the heart and regions that contribute to the formation of the heart. Ntrk3, Ror2 and Wnt5a were expressed in the pharyngeal arches and heart region. The expression of the genes Ntrk3, Ror2 and Wnt5a were not only restricted to the heart regions but were also seen in the neural tube area. We also examined the expression of Ror2 in Crkl knock-out embryos, but observed no change. The results may support our hypothesis that NTRK3, WNT5A, and ROR2 may be causative of CHDs, since they were found to be expressed in the heart and regions required for heart development, however, more work is needed to prove this. More work is also needed to show whether any of these genes act in the same pathway as genes in the 22q11 deleted region to function in normal heart development.

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Life/Biological Sciences Presenter: Claudio Vázquez, Patricia N.

Mentor: Rubin, Michael

Title: Molecular Phylogenetic Analyses of Plant Genomic Regions Amplified Using PCR

Authors: Patricia N. Claudio Vázquez (UPR-CAYEY), Paola K. Pereira (UPR-CAYEY), Nicole S. Rivera (UPR-CAYEY), Marlene D. Rivera (UPR-CAYEY), Perla M. Elosegui (UPR-CAYEY), Nicolle A. Rosa (UPR-CAYEY)

Abstract

The conventional way of classifying plants involves using gross morphological criteria to divide them into similar groups. We have selected several DNA barcoding regions in hopes of identifying a marker that will allow us to taxonomically classify plants more accurately. The genomic regions of interest are rpoC1, rpoB, trnH-psbA, rbcL, matK, accD and ycf5, and these were chosen based on their potential to identify species. We PCR amplified these regions using specific primers after extracting the genomic DNA from several plants endemic to Puerto Rico or possessing medicinal value: A. thaliana, M. charantia, P. major, R. officinalis, M. piperita, A. indica. M. indica. Putative PCR products of the predicted sizes for rpoC1, trnH-psbA and rbcL from M. charantia and R. officinalis genomic regions, as well as accD from R. officinalis were visualized using agarose gel electrophoresis. Only rpoC1 and trnH-psbA putative PCR products were detected in P. major genomic DNA. Putative PCR products of the predicted sizes for rpoC1, trnH-psbA, rbcL and accD were detected in M. piperita genomic DNA. The only PCR product detected in A. thaliana was PCR amplified using trnH-psbA specific primers. Based on these results, we conclude that trnH-psbA is a prospective marker for taxonomic classification, due to PCR amplification of putative products of the expected size for this primer pair in numerous plants. Future work includes DNA sequence determination and analyses using bioinformatics tools, which will help us elucidate their evolutionary history and construct phylogenetic trees. The RISE Program and the Department of Biology at UPR-Cayey supported this work.

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Life/Biological Sciences Presenter: Collazo Meléndez, Samuel A.

Mentor: García Arrarás, José

Title: Amphibian Sex Determination

Authors: Samuel A. Collazo Meléndez (Universidad de Puerto Rico - Recinto de Río Piedras), Vilmarys Figueroa (Universidad de Puerto Rico - Recinto de Río Piedras), Zuania Colón (Universidad de Puerto Rico - Recinto de Río Piedras), Carla Restrepo (Universidad de Puerto Rico - Recinto de Río Piedras), José García Arrarás (Universidad de Puerto Rico - Recinto de Río Piedras)

Abstract

The mechanisms of sex determination are very diverse. In amphibians, the most common system is genetic (GSD), however, within this system there is significant variation. In some species, the determination of sex is based on XX (?) and XY (?) sex chromosomes, in other species it is based on ZZ (?) and ZW (?), and still in other species there is an absence of sex chromosomes. In these species, the identification of sex determining genes is the only way to determine specific mechanisms of sex determination. Discovering the mechanism of sex determination is vital for our conceptual knowledge and its practical implications. For example, this knowledge can be important for managing endangered species or understanding the impact of environmental factors on animal populations. Such is the case with Eleutherodactylus coqui, the most common frog in Puerto Rico. Previous observations showed that coqui frogs from highly disturbed habitats had a higher prevalence of subtle skeletal abnormalities than those from protected ones. Also, work by others has shown that E. coqui lacks sex chromosomes. As a preliminary step to establish an association between the prevalence of skeletal abnormalities and frog gender at hatching, we aimed to identify sex determining genes in E. coqui. Due to substantial progress in genomics, the genes involved in the sex determination in several Anuran species have been identified. For this investigation, four genes were selected (CYP19, SF-1, Sox9 and Sox17) as candidates of the sex determining gene of E. coqui. Reproductively mature male and female adults were captured in the metropolitan area of San Juan in order to obtain testes, ovaries, and toes. Afterwards, DNA and RNA was extracted using standard methods and Polymerase Chain Reaction (PCR) primers were prepared according to the gene sequences found in the database of the National Center for Biotechnology Information (NCBI). In addition, complementary DNA (cDNA) was synthesized with the extracted RNA. The analyses of PCR and Gel Electrophoresis showed that Sox9 and Sox17 were present and expressed in the testes and ovaries of reproductively mature male and female E. coqui. Work in progress is aimed at determining whether other sex-related genes can serve as sex determination markers.

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Life/Biological Sciences Presenter: Colon Morales, Bryan

Mentor: Garcia Arraras, Jose

Title: Cellular Components of the Intestinal Connective Tissue in Normal and Regenerating Sea Cucumbers

Authors: Bryan Colón Morales (University of Puerto Rico, Rio Piedras Campus), Daniela Díaz Rubayo (University of Puerto Rico, Rio Piedras Campus), Jasmine Santana Pérez (University of Puerto Rico, Rio Piedras Campus), José E. García Arrarás (University of Puerto Rico, Rio Piedras Campus)

Abstract

The formation of the blastema or rudiment is a key step during organ regeneration. Thus, many investigations have focused on determining the type of cells and the site of origin of the cells involved in this process. The sea cucumber, Holothuria glaberrima, has the capacity to regenerate most of its internal organs, followed by a typically induced evisceration. Studies using different antibodies, that label many different cellular components, have been done during intestinal regeneration in this model system. Although many different cellular markers have been used to characterize cells at different stages of regeneration, it is not clear whether we can account for all cells present within the connective tissue of the growing rudiment. At present we are working with several cell markers (antibodies IF6, 2E6 and X1E1) that label spherule containing cells, (antibody Meso1) that labels mesothelial components or (antibodies RN1, EN1, B-Tubulin) that label nervous components of the sea cucumber intestinal system. DAPI nuclei staining is used to determine the total number of cells. Our results show that while certain cell populations do not change during the regenerative process, others such as spherulocytes and mesothelial cells increment in the connective tissue at certain stages of regeneration. This corresponds to a previously observed epithelial to mesenchymal transition. Additional results are in progress to determine the origin of the cell populations. We are also working with other antibodies in order to be able to account for 100% of the cells within the regenerating rudiment so as to be able to determine the cells that make up the intestinal blastema.

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Life/Biological Sciences Presenter: Correa Pascuas, Nicolas

Mentor: Fahey, Robert

Title: Net primary production beyond the disturbance threshold in changing world: Does lack of subcanopy growth limit resilience?

Authors: Nicolas Correa Pascuas (University of Puerto Rico Rio Piedras)

Abstract

Climate change related largely to high greenhouse gas emissions is a process that is leading to alteration in the biosphere. These rapid changes can induce higher frequency of disturbances and catastrophes, which in turn may impact the balance and function of forest ecosystems. Forests play a role as natural carbon sinks, helping mitigate climate change. Severe, stand-replacing disturbance events can result in the complete loss of forest canopy and a resulting change in function, severe disturbances are well documented. However, it is unclear how forests respond to less severe, moderate disturbance events, in which only a portion of the canopy is removed. In previous studies it was shown that forest productivity was resilient to increasing disturbance severity up to a threshold, in which net primary production abruptly decreased. The causes undermining the suggested threshold are not well understood, subcanopy response may play an important role in sustaining productivity. In this study, we build previous work and ask: 1.Does productivity drop with increasing disturbance? 2. Is there a lack of subcanopy response at high disturbance severity? And 3. Is a lack of subcanopy response related to mortality? We suggest that higher disturbance will limit productivity, subcanopy response may not compensate at very high disturbance and higher disturbance is related to subcanopy mortality

Life/Biological Sciences Presenter: Cruz Castro, Stephanie

Mentor: Nufio, Cesar

Title: The effects of climate change on the fitness and longevity of a subalpine grasshopper

Authors: Stephanie Cruz Castro (University of Puerto Rico, Rio Piedras)

Abstract

Over the last few decades, global climatic change has had a dramatic effect on the biology and demography of plants and animals. Three of the most commonly documented effects include advancements in the phenology organism's , changes in species distribution patterns, and changes in 240

community composition that alter the species interactions. These changes can also have strong have effects on the fitness and longevity of organisms. In this experiment we worked with the species Melanoplus dodgei which are a short winged grasshopper species with a high potential for local adaptation and forb feeders. We test the hypothesis that as cooler climates may set limits on the reproductive capacity and longevity of grasshoppers, a warmer climate should increase the reproductive output and longevity of grasshoppers. To prove that, two field cage studies were conducted: one in 2012 (warm year) and one 2015 (cool year). In the field cage experiment, 24 males and 56 females M. dodgei, were collected from the field site (the meadows) and placed in cages. Then the initial weight and length (femur size) were measured, they were marked with non-toxic paint and then 6 males and 14 females were placed into one of four cages. They were individually measured every three days. After collecting many data, our hypothesis was supported because on warmer years, grasshoppers deposited egg pods more frequently and laid larger clutches. As to longevity,females lived longer in 2012.

Life/Biological Sciences Presenters: Cruz Mendoza, Alberto C. Concepcion Cruz, Mark A.

Mentor: Velazquez, Iris

Title: Foraging Devices to Stimulate Puerto Rican Parrots (Amazona vittata) to Explore and Maneuver for Food Location Before Field Reintroduction: 2015 Series II

Authors: Alberto C. Cruz Mendoza (University of Puerto Rico - Humacao Campus), Mark A. Concepción Cruz (University of Puerto Rico - Humacao Campus), Iris M. Velzquez Oliveras (University of Puerto Rico - Humacao Campus), Josean Maldonado (University of Puerto Rico - Humacao Campus), Ricardo R. Claudio Gonzalez (University of Puerto Rico - Humacao Campus), Jafet Velez (US Fish and Wildlife Service - Aviary Iguaca El Yunque)

Abstract

Every year, after closely monitoring the population of captive parrots, a sample is selected and is evaluated to select potential subjects for field reintroduction. On 2014, we introduced a new phase to the already stablished protocol of PRE-RELEASE TRAINING. In this training, parrots were presented to a FORAGING APPARATUS (FA) designed to stimulate them to explore and to maneuver in order to get access to food. The 2015 release sample consisted of 24 parrots. Each trial consisted in two-hour observation periods made on the same day, prior to the routine food provisioning. During the first hour of observation, parrots were observed in the absence of a FA or other food sources (i.e. No-FA Trials). Every minute, after a signal given by a timer, the number of parrots in each of the four areas of the cage (A, B, C and D) was annotated (60 time intervals/trial). During the second hour, the same procedure was repeated, but in the presence of two FA (Two-FA Trials; hereafter called Series I). Series II consisted in 241

presenting only one randomly located FA. Similar to preliminary results from the 2014 sample, 0% of the parrots from the 2015 sample learned to use the FA. In Series I, parrots showed a preference for one site of the cage during the No-FA Trials. But, during the Two-FA trials of series I, cage preference changed, possibly avoiding one of the FA that was located on their preferred place. The preliminary results of Series II suggest suggests parrots tend to avoid the site of the cage where the FA is located. In some trials the whole sample displaced to the non-preferred site of the cage when the FA was located on the preferred site. The study suggests these parrots are neophobic (i.e. afraid of novelty). This study is still in progress and we are examining the 2016 release sample. We expect parrots will habituate to different FA and will learn to maneuver in order to find food.

Life/Biological Sciences Presenter: Cuevas Cruz, Julio M.

Mentor: Garcia Arraras, Jose

Title: Antibiotic Effects on Intestinal Regeneration of the Sea Cucumber Holothuria glaberrima

Authors: Lymarie Díaz (UPR- Rio Piedras), Julio M. Cuevas Cruz (UPR- Rio Piedras), Paola I. Rodriguez (UPR- Rio Piedras), Sonya J. Cajigas (UPR- Rio Piedras)

Abstract

Throughout the years, bacteria have been mostly recognized for the pathogenic roles; however, studies in the last few decades proved how these microorganisms play an essential part in living systems. Some researchers have been studying the relevance of intestinal microbiota on different hosts, and found that gut microbiota plays an important role on the organisms' metabolism and overall health. We are therefore evaluating the effect of the intestinal microbiota in the process of intestinal regeneration in our animal model, the sea cucumber Holothuria glaberrima. Previous laboratory studies established the presence of commensal bacteria in this animal model. In order to dissect the role of these bacteria, a group of animals were treated with Kanamycin, Erythromycin, Pen/Strep or Neomycin to reduce the bacterial population during the regeneration process. The effects were measured at the histological level; several cellular processes were evaluated for potential changes in: intestinal growth, proliferation, cellular differentiation and remodeling of the extracellular matrix. Our results suggest that after treatment with certain antibiotics, the intestinal rudiment size in regenerating sea cucumbers was smaller than in animals that did not receive antibiotics. Although further experimentation is required to determine if the microbiota plays a direct role in the process of regeneration our results strongly suggest that gut microbiota can delay and disrupt the mechanism of wound healing and regeneration. Research was funded by NSF (IOS-0842870), NIH (R15NS01686) and the University of Puerto Rico. Julio M. Cuevas Cruz and Paola Rodriguez were funded by PR-LSAM program of the University of Puerto Rico.

242

Life/Biological Sciences Presenter: Davila Pagan, Alejandro

Mentor: Morales, Reginald

Title: The study of phosphatidylcholine pool in the red blood cell membrane

Authors: Alejandro Davila Pagan (University of Puerto Rico Rio Piedras Campus), Reginald Morales (University of Puerto Rico Rio Piedras Campus)

Abstract

The human red blood cell (RBC) membrane lipid composition is an object of pathological investigation because it is a good indicator of many pathological conditions. Recent studies have determined the lipidomics of RBC but these have been primarily of total membrane lipids. One mayor problem being that the composition of phospholipids the inner and outer leaflet of RBC membrane varies and more than likely, only the outer leaflet composition is a good indicator of serum lipids. These studies do not show the different composition of the leaflets. The objective is to determine experimentally if the RBC phosphatidylcholine (PC) has different sn-1 acyl compositions on the external leaflet versus the internal leaflet of the membrane bilayer. The RBC are enucleated and do not have any cytoplasm membranes. The composition was precise because there will not be membranes from other organelles affecting the results. Phospholipase A2 (PLA2) from Naja mossambica was used to obtain the PC from the outer membrane. PLA2 release the sn-2 acyl group of glycerophospholipids from the exterior of the membrane. In this experiment, high levels of PLA2 (400ug/ml) were used to hydrolyze membrane surface glycerophospholipids. The lipid fraction was separated by TLC and the individual phospholipids were then subjected to methanolysis by refluxing with 1% sulfuric acid in methanol. These FAME were analyzed by Gas Chromatography in a Model 7890A Agilent chromatograph using a DB-23 capillary column.

Key words: red blood cell, PC, PLA2, FFA

243

Life/Biological Sciences Presenter: De Jesus Astacio, Luis Miguel

Mentor: Baez, Carlos

Title: Electrical Fingerprinting Characterization of the Interaction between alpha7 and dupalpha7

Authors: Carlos Báez Pagán (UPR-RP), Jose Lasalde Dominicci (UPR-RP)

Abstract

The goal was to probe if these hybrid pentamers form and measure the effects of co-expression in the channel's functionality. We hypothesized that hybrid pentamers containing both subunits exist and can explain the altered functionality of alpha7 ion channels, as opposed to protein-protein interactions between homogeneous alpha7 and dupalpha7 complexes. Using the patch clamp technique seems a logical approach towards solving the problem but immediate obstacles arise; alpha7 nAChR ion channels (with or without the possible hybridization) desensitizes very quickly, in the order of 10^-3s. Thus, it is extremely difficult and imprecise to determine the amplitude of the single-channel openings. We used the positive allosteric modulator PNU-120596 to extend the open-state 10^4 fold and thus enable reliable determinations of current amplitudes. Such intervention, in conjunction with three alpha7 point mutations that reduces single-channel conductance, constituted our electrical fingerprinting strategy to test our hypothesis. Our results suggest that dupa7 regulates the functionality of the alpha7 by forming alpha7-dupalpha7 hybrid channels. In conclusion, we have provided evidence that regulation of the important alpha7 nicotinic receptor can result from the introduction of dupalpha7 subunits into alpha7 pentamers.

Life/Biological Sciences Presenter: Detrés Román, Carlos R.

Mentor: Planas, Jose

Title: Halobacteria as a Source of Food Coloring Pigment

Authors: Jose M. Planas Rivera (UPR-Aguadilla), Carlos Ruiz Martinez (UPR-Aguadilla), Carlos R. Detres Roman (UPR-Aguadilla), David M. Perez Pardo (UPR-Aguadilla)

Abstract

Food coloring is an important area of the food processing industry. Actually, there are three ways to obtain these pigments which are, synthetic, natural and by fermentation. The majority of the one used 244

in the industry are the synthetic ones, which are expensive to produce. This investigation will address the following problem: Could be possible to obtain these pigments by fermentation process using halobacteria as a source? Our hypothesis is that halobacteria can produce pigments that can be use as food coloring. This project will address the first phase of it which will isolate the carotenoids pigments produced by four different halobacteria, characterize them by Thin Layer Chromatography, HPLC and LC- MS analysis. We will determine the levels of expression of these pigments and compare them among the halobacterias.

Life/Biological Sciences Presenter: Diaz Tañón, Ambareliz

Mentor: Arroyo-Cruz, Luz V.

Title: Diversity Profiles in the Oral Cavity Bacteria in three Species of Micro Chiroptera Related to their Diets in the North of Puerto Rico

Authors: Ambareliz Díaz Tañón (Universidad del Turabo), Marlenne Trinidad Pabón (Universidad del Turabo), Luz V. Arroyo Cruz (Universidad del Turabo)

Abstract

There's at least 13 species of bats that can be found in the island of Puerto Rico. These are the only flying native mammals to the island, and are active at pollinating native flora, dispensing seeds, and controlling insects such as mosquitoes. The diversity in their diets of each different species can be seen in their bacterial ecology, as it varies for each, according to what it consumes.

The purpose of this research is to identify three different species of bats (Eptesicus fuscus, Noctilio leporinus, and Artibeus jamaicensis) according with their oral microbiota using their saliva as a sample.

Samples where obtained in two different days, in Bosque Julio Enrique Monagas, Bayamón. Each bat differ from their physiological aspect and age. All saliva samples (6) have been obtained using a sterile swab and incubated (33.7°C) in test tubes containing nutrient broth for two days. Then it was transferred to 50ml flask with nutrient broth, to increase bacteria concentration. Isolated microscopic individuals were studied for their morphological aspects and microscopic structure.

At this moment, there's only samples of E. fuscus species. Our preliminary results demonstrate presence of coccus and rods, and bacteria Gram-positives and Gram-negatives. Two bacteria have been recognized by their morphological aspects and microscopic structure: Serratia marcescens, and Pseudomonas aeruginosa.

Future work include a series of biochemical tests will be conducted to improve the identification of the isolated bacteria, followed by a T-RFLP analysis to understand the diversity of bacterial communities 245

when all samples of the three species have been obtained and reach to a conclusion if it is possible to identify the species of bats for their oral microbiota.

Life/Biological Sciences Presenter: Figueroa, Patricia

Mentor: Avalos, Javier

Title: Effects of Ag-GQD Nanocomposites and Electric Bias on the Bacterial Growth of S. aureus and P. aeruginosa

Authors: Patricia Figueroa (University of Puerto Rico- Bayamón), Andre Marra (University of Puerto Rico- Rio Piedras), Coral Ramos (University of Puerto Rico- Bayamón), Javier Avalos (University of Puerto Rico- Bayamón), Brad Weiner (University of Puerto Rico- Rio Piedras), Gerardo Morell (University of Puerto Rico- Rio Piedras)

Abstract

Ag-Graphene nanocomposite solution exhibits strong antibacterial activity against both Gram positive and Gram Negative bacteria. The functionalization of this Ag-Graphene nanocomposite with polyethylene glycol provides stabilization and higher solubility in aqueous solution. The antibacterial property of this nanocomposite was previously tested by Kirby-Bauer assay disk diffusion and Minimum Inhibitory Concentration (MIC) assay using Pseudomonas aeruginosa and Staphylococcus aureus as model strains for both types of bacteria. We hypothesize that by applying an external electric bias; a decrease in the bacterial inhibition time (less than 6 hrs.) can be attained. Gram positive and negative bacteria's cell wall differ greatly in structure; therefore, concentrations of the Ag-GQD solution will vary for both types of bacteria. Preliminary data from this method suggests a significant difference in terms of decreased bacterial growth between control and experimental groups treated with the bias electrical field. As expected, the concentration of Ag-GQD had to be different between strains due to their cell wall composition and different interactions between the Ag ions and the negatively charged proteins in their cell wall. Taking advantage of the high biocompatibility of graphene and the antibacterial activity of silver, the Ag-GQD nanocomposite becomes an effective nontoxic biomaterial suitable for numerous applications, such as self-sterile textiles, biomedical devices, coatings and cosmetics.

246

Life/Biological Sciences Presenter: Figueroa Ríos, Lysmarie

Mentor: Suarez, Edu

Title: Characterization of the Unique Viscoelastic Properties of the Mitral Valve Anterior Leaflet

Authors: Lysmarie Figueroa-ríos (University of Puerto Rico at Ponce), Bryn Brazile (Mississippi State University), Sallie Lin (Mississippi State University), Brandon Nelson (University of Pittsburg), Jun Liao (Mississippi State University)

Abstract

The most common mitral valve (MV) disease is the MV regurgitation, in which the anterior leaflet and the posterior leaflet cannot coapt well and hence result in the leaking of blood from the left ventricle to the left atrium during the systolic phase. The treatment options include MV replacement and repair. In order to develop a bioprosthetic or a tissue engineered mitral valve leaflets that behaves similarly to the native MV, the mechanical properties of the native MV leaflets must be well understood (Grashow et al., 2006). In this study, we aim to characterize the unique viscoelastic properties of mitral valve anterior leaflet by studying the mechanical behavior of the tissue in regards to stress-relaxation, creep, and tissue failure. Mitral valve anterior leaflets (MVAL) of porcine specimens were obtained from a local abattoir. These specimens were then further dissected in the circumferential direction into a dog-bone shape samples for mechanical testing at a target load level of 600 grams. The testing protocol for each sample was performed as follows: after preconditioning, leaflet tissue was subjected to (1) stress- relaxation for 15 minutes, followed by (2) creep for 15 minutes, and finally (3) the sample is ultimately pulled to failure. All testing was performed in a PBS bath using a Test Resources uniaxial testing machine. We observed a normal degree of stress relaxation similar to other types of collagenous tissues (~30% - 50%), but negligible creep. Understanding the unique viscoelastic properties of the native MV leaflets at different loading levels would help to better design bioprosthetics or tissue engineered mitral valves that mimics the natural design and the optimal tissue behavior.

247

Life/Biological Sciences Presenter: Flores, Ian G.

Mentor: Acevedo, Miguel

Title: Hosts have similar probabilities of being infected

Authors: Ian Flores Siaca (University of Puerto Rico; Rio Piedras Campus), Miguel Acevedo (University of Puerto Rico; Rio Piedras Campus)

Abstract

Mosquito-borne diseases (MBD) are prevalent in nature causing more than 17% of all infectious diseases in humans. They are also responsible for regulating other vertebrate host populations and mediating species coexistence. Mathematical models help us improve our understanding of the complex relationship between hosts, vectors and pathogens . Most models assume homogenous mixing--that all hosts have the same probability of being infected. Homogeneous mixing may be rare in nature where just a small number of individuals are responsible for most of the infections. These highly infective individuals may correspond to particular stage classes or may live clustered in space with some sites with high probability of infection and some with low probability of infection. Based on this, we hypothesize that infective individuals are clustered in space, violating an important assumption of classical models. To test this hypothesis, we studied lizard-malaria infections in El Verde Field Station where three Plasmodium species naturally infect Anolis gundlachi. A. gundlachi forages in the ground and in the trees in the montane forests of Puerto Rico. We examined the distribution of the trees where lizards forage (N=1,294) in a primary growth forest, which showed a clumped distribution. Then, we examined the distribution of lizards (N=122), correcting for body size. We found that both the lizard host and infections were spatially clustered. Our results suggest that infections are spatially heterogeneous violating important assumptions of MBD theoretical models.

Life/Biological Sciences Presenter: Garcia Collazo, Cid M

Mentor: Arroyo-Cruz, Luz V.

Title: Presence of Bacterial Flora in Artisanal and Commercial Honey in Puerto Rico

Authors: Cid Marie Garcia Collazo (Universidad del Turabo Barceloneta) 248

Abstract

Honey is a rich and nutritious substance produced by Apis mellifera bee. It is used as medicine or as an effective remedy against various infections since ancient times. Much is known about the use of honey, but little is spoken about the bacteria found in the natural flora of honey. Particularly, how they are present in pure artisan honey versus pure commercially honey. The main objective of this research is to compare and describe the bacterial flora of the two types of pure honey (artisanal versus commercial) in Puerto Rico. The applied methodology consisted of both qualitative and quantitative analysis of three samples of honey, two artisan samples from (a hive from Mayagüez, and a Beekeeping School in Camuy) and a commercial sample brand (El Cafetal). Samples were serially diluted 10-1 to 10-5 and inoculated into culture medium Tryptic Soy Agar, in triplicate, for colony counting. Additionally, were isolated by grooved and Gram staining was to the colonies in each sample honey. On all three honeys evaluated average number of colonies for artisan honey were obtained from 56 and 67 respectively, and 88 for commercial honey. Presence of Cocci and Bacillus, Gram positive and Gram negative was found; and 14 unknown bacteria (4, 5 and 5, respectively) were isolated. According to this research, we conclude that the largest population of bacteria was obtained by commercial pure honey and a predominant presence of Cocci, and Gram negative bacteria between all three samples. For future studies it is suggested: biochemical tests to identify unknown bacteria isolated and relate them to the bacterial flora of the bees.

Life/Biological Sciences Presenter: González Segarra, Amanda J.

Mentor: Garcia Arraras, Jose

Title: Neural Circuit Characterization of the adult sea cucumber H. glaberrima

Authors: Amanda González-segarra (Universidad de Puerto Rico, Río Piedras), José E. García- arrarás (Universidad de Puerto Rico, Río Piedras)

Abstract

Echinoderms, like vertebrates, are deuterostomes. Due to their evolutionary proximity to vertebrates, they could be key in improving our knowledge of the mammalian nervous system. The sea cucumber, an echinoderm, has been used as a model in many scientific studies because of their regenerative capacities. However, what is known about the nervous system of the sea cucumber has been achieved studying the larval stage of the animal. This project's goal is to elucidate the neural network of the adult species Holothuria glaberrima. To achieve this we are inserting neuronal tracers that mark the nervous system retrogradely and anterogradely. Since this experiment has not been done previously in sea cucumbers, we first had to determine the best neuronal tracer and method of insertion. We used 3 different neuronal tracers, Micro-Emerald, NeuroVue Jade, and Texas Red. We also used several strategies to insert the neuronal tracer, varying the solvent, area of insertion, and exposure time to the 249

neuronal marker. Data suggest that the best neuronal tracers were Micro-Emerald and Texas Red, the best solvents were water and Vaseline, and the best area of insertion was the radial nerve. We have found at least four projections from the radial nerve that extend between the longitudinal and circular muscles. Our findings, along with further experimental analysis, can provide greater insight into the anatomy, function, development and evolution of the mammalian nervous system.

Life/Biological Sciences Presenter: González Torres, Mayra I.

Mentor: Appleyard, Caroline

Title: Effect of the Probiotic Mixture VSL#3 on Macrophage and Proliferating Cell Numbers in the Liver of Rats Undergoing Acute Colitis

Authors: Mayra I. González Torres (University of Puerto Rico - Ponce Campus), Raymond A. Isidro (Ponce Health Sciences University & Ponce Research Institute), Abdón López (University of Puerto Rico - Ponce Campus), Myrella L. Cruz (Ponce Health Sciences University & Ponce Research Institute), Angel A. Isidro (Ponce Health Sciences University & Ponce Research Institute), Caroline B. Appleyard (Ponce Health Sciences University & Ponce Research Institute)

Abstract

Introduction: Patients with Inflammatory Bowel Disease are vulnerable to developing extra-intestinal disorders, usually in the liver and biliary system. Macrophages have been shown to accumulate in the liver in several animal models of colitis. The probiotic mixture VSL#3, which consists of 8 bacterial strains, has been suggested to exert its beneficial effects in part by decreasing proliferation. As with most tissue-resident macrophages, Kupffer cells (hepatic macrophages) are thought to have proliferative capacity. Our aim was to examine the effect of the probiotic mixture VSL#3 on the liver of rats undergoing acute colitis. Methods: Male Sprague Dawley rats were randomly assigned to normal (n=5), colitis (n=9) or colitis+VSL#3 (n=12) groups. For a week prior to colitis induction and until the time of sacrifice, colitis+VSL#3 rats were treated daily with 10 billion CFU of the probiotic in drinking water. Control rats received water during this period. Colitis was induced by intracolonic administration of trinitrobenzene sulfonic acid (0.5 mL, 60 mg/mL). Rats were euthanized three days after colitis induction. At the time of sacrifice liver samples from each rat were collected. Hematoxylin and eosin staining of liver tissue was used to assess histology. Macrophage numbers and cell proliferation was assessed using double immunofluorescence staining of formalin-fixed paraffin-embedded liver tissue for CD68 and Ki67. Total macrophages (CD68+), proliferating cells (Ki67+) and proliferating macrophages (CD68+Ki67+) were quantified in the hepatic parenchyma surrounding the central vein and the portal areas of each sample. Results: Tissue from rats undergoing colitis demonstrated inflammatory infiltrates in the portal areas, sinusoids, and hepatic parenchyma. Colitis rats predominantly contained mild portal 250

infiltrates and patchy but diffuse sinusoidal infiltrates, with occasional neutrophilic infiltration in the parenchyma. Colitis+VSL#3 rats mostly displayed inflammatory infiltration of the larger portal areas with mixed neutrophilic and mononuclear infiltration in the sinusoids. The total number of macrophages (CD68+) in proximity to the central veins and the portal areas was significantly higher in colitis (p

Life/Biological Sciences Presenter: Gorbea Colón, Jose J.

Mentor: Agosto Rivera, Jose Luis

Title: Zirconium phosphate nanoparticle studies on sleep behavior and mortality in Drosophila melanogaster

Authors: Jose J. Gorbea Colón (Universidad de Puerto Rico Río Piedras), Norma Rodríguez (Universidad de Puerto Rico Río Piedras), Bárbara Casañas (Universidad de Puerto Rico Río Piedras), Jorge L. Colón (Universidad de Puerto Rico Río Piedras), José L. Agosto Rivera (Universidad de Puerto Rico Río Piedras)

Abstract

Recent efforts in search of "magic bullet molecules", that achieve desired therapeutic effects whilst diminishing side-effects, have become exceedingly expensive and in most cases futile. Drug delivery systems aim to circumvent this problem in modern drug discovery by taking known compounds and modifying their in vivo activity. Zirconium phosphate (ZrP) nanoparticles have shown to be a viable non- cytotoxic platform for the encapsulation and administration of drugs such as cis-platin, doxorubicin, carbamazepine and even insulin. The fact that such molecules can be introduced via the ZrP system hints at a very enticing opportunity for the development of new treatments for diseases such as cancer and diabetes. Given the potential future uses of the ZrP system in medicine, we use Drosophila melanogaster, (a thoroughly studied animal model where the effects of nanoparticle drug delivery systems have been previously examined), in order to test the effects of peroral ZrP administration on fly sleep behavior and establish a lethal dose for future experimentation using this drug delivery system/animal model combination. We also investigate whether these sleep behavior effects can be reversed and mortality reduced by means of ending continuous peroral administration of ZrP. To achieve this, ZrP nanoparticles were synthesized from zirconium (IV) chloride and phosphoric acid and assayed using powder XRD. ZrP nanoparticles were then suspended in fly food in ascending concentrations of 0.00 mg/mL, 0.25 mg/mL, 2.50 mg/mL and 25.00 mg/mL. The sleep patterns of wild type Oregon R (OreR) flies were assayed under standard Light/Dark (LD) cycles. Assayed flies had continuous access to food stocks for 1 week before exchanging stocks with new ones containing either the same ZrP concentrations (continuous treatment) or switching their stocks to new food without ZrP (non-continuous treatment). After monitoring the data for two weeks, data was analyzed with MatLab, Prism and JMP computer software. From these studies we report that concentrations of up to 2.50 251

mg/mL were safe in terms of mortality rate. However in terms of sleep behavior, we did observe alterations suggesting that sleep is a more sensitive measure of toxicity. Non-continuous treatment reversed sleep behavior phenotypes in some cases as well as reduced mortality for some groups. In conclusion, further studies are needed, however in lower concentrations this ZrP system seems to be a promising alternative for the development of new drug delivery strategies.

Life/Biological Sciences Presenter: Grau Cruz, Emilio E

Mentor: Rivera-Marchand, Bert

Title: Evaluation of Sociality In a Caribbean Halictid Bee

Authors: Emilio E. Grau-cruz (Universidad Interamericana Recinto de Bayamon), Bert Rivera- marchand (Universidad Interamericana Recinto de Bayamon)

Abstract

Environmental conditions have been associated with the evolution of sociality in bees of the Halictidae family where eusociality is more common in warmer than in colder environments. This hypothesis has not been examined closely in a tropical island context. Although the tropical islands are known for their warm climates, in some cases resource limitations make them more like temperate regions than the continental tropics. The Caribbean sweat bee Lasioglossum (Dialictus) gundlachii Baker (Hymenoptera: Halictidae) has been reported to be communal or semi-social. However, this has not been evaluated with morphological and genetic methods. In this study, we collected foraging individuals and dissected them to determine if they were inseminated. Our preliminary results indicate that most of the examined individuals had developed ovaries suggesting that L. (Dialictus) gundlachii is likely to be communal rather than social. We plan to corroborate this data with microsatellite markers.

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Life/Biological Sciences Presenter: Haddock III Soto, Luis A

Mentor: Gonzalez, Carlos

Title: Functional Role of UPF2 Phosphorylated Regions in Translation Termination in Yeast

Authors: Luis Antonio Haddock Iii Soto (Department of Biology, University of Puerto Rico – Río Piedras), Edgardo M Colón Morales (Department of Biology, University of Puerto Rico – Río Piedras), Qishal Lin (Proteomics and Mass Spectrometry Services, Center for Functional Genomics, University at Albany, SUNY), Clarivel Lasalde (5Department of Biology, University of Puerto Rico- Bayamon), Dr. Carlos I Gonzalez Vargas (Department of Biology, University of Puerto Rico – Río Piedras, 2Department of Biochemistry, UPR- Medical Sci)

Abstract

Eukaryotes have evolved a unique mechanism for recognizing premature termination codons (PTC) present in the mRNA. These PTC-containing mRNAs are recognized and degraded by a mechanism known as nonsense-mediated mRNA decay (NMD), which prevents the formation and accumulation of non-functional or truncated proteins that can be the starting point for several human diseases, such as Cystic Fibrosis and Duchenne Muscular Dystrophy. One of the proteins involved in NMD is the up- frameshift protein 2 (UPF2), which has been shown to be phosphorylated and essential for the accuracy of translation termination. However, the functional role of Upf2 phosphorylated residues in the translational termination accuracy is still unknown. To test this, we generated deletions of several UPF2 regions containing phosphorylated residues and measured the growth rate of a Saccharomyces cerevisiae strain that harbors the can1-100allele in the presence of Canavanine. Results demonstrated that deletion of the regions in Upf2 corresponding to amino acids (aa) 50-59 and 421-430, showed less growth due to a higher sensitivity to Canavanine caused by a faulty translation termination. Also, sub- region deletions within the previously described regions of Upf2 (aa 50-53, 57-59, 421-423, 425-428) showed no disruption in the Translation Termination process measured by the presence of the can1-100 PTC containing gene in the Canavanine sensitivity assay. This suggests that the regions corresponding to aa 50-59 and 421-428 of Upf2 are crucial for translation termination accuracy and provide a foundation for future studies to determine the role of Upf2 phosphorylation in the fidelity of translation termination in eukaryotes.

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Life/Biological Sciences Presenter: Hernandez Hernandez, Cristal I.

Mentor: Martinez-Cruzado, Juan

Title: Distribution of a Wilson's Disease Causing Loss of Function Mutation in Gene ATP7B in Southwest Puerto Rico

Authors: Cristal I. Hernandez Hernandez (University of Puerto Rico at Mayaguez), Raquel Vicario (University of Puerto Rico at Mayaguez)

Abstract

The ATP7B gene encodes for an ATPase which mainly codes for cellular transport of copper within hepatocytes. Ninety percent of Wilson's Disease (WD) cases are caused by a loss-of-function mutation in this gene, leading to a decreased excretion of copper into bile. Copper then accumulates in the liver and eventually flows with the bloodstream and is accumulated in other organs, such as the kidneys, corneas and the brain with probable fatal consequences. A mutation altering the acceptor splicing site of intron #11 that is strongly predicted to bar gene function has been detected in a family afflicted by WD in southwestern Puerto Rico. This single nucleotide polymorphism (SNP) was recently detected in Phase 3 of the 1000 Genomes Project only in a heterozygous Puerto Rican among the 2504 individuals sampled by the Project worldwide. It was given the ID rs367956522. We have now found it in its homozygous form in one case, and in its heterozygous form in seventeen, out of 217 samples assayed in southwest Puerto Rico. These seventeen cases have been found within four families with a genealogy of very few generations- the biggest being of only five generations. We have further found that homozygous and heterozygous individuals are conversely homozygous or heterozygous for a second mutation located within the pyrimidine tract of the intron #16 of the gene (rs140708492). We have also found three samples heterozygous for only the rs140708492 polymorphism, which is a rare variant specific to Europe, and therefore we deduce that the SNPs are linked and that the mutation generating rs367956522 occurred in a chromosome that already had rs140708492. We are now expanding the study to other areas of Puerto Rico. In addition, people heterozygous for any of the mutations are being given free access to medical tests that will allow us to determine their phenotypic effects, if any, in their heterozygous form. With this information we will try to trace the origin of rs367956522 and may be able to determine if a recommendation should be made to test for this SNP as a possible routine exam to newborns in the region or across Puerto Rico.

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Life/Biological Sciences Presenter: Hernández Rodríguez, Rey

Mentor: Quesada, Orestes

Title: Effects of TAT Peptide and Membrane Bending Energy in Ca2+-Triggered Exocytosis of Chromaffin Cells

Authors: Rey Hernández-rodríguez (University of Puerto Rico, Río Piedras Campus), Che-wei Chang (University of Wisconsin-Madison), Meyer B. Jackson (University of Wisconsin- Madison)

Abstract

Fusion pores are necessary intermediates in the release of vesicles content. This pore is known to be initially formed by a core complex between transmembrane proteins in both membranes. However, this complex bends the membrane into a highly curve shape, causing membrane stress, and pore dilation. The interaction of a cell penetrating peptide (CPP), called TAT peptide, with chromaffin cells altered the fusion pore stability and the exocytosis activity. These results support the importance of membrane bending in regulating fusion pores kinetics in Ca2+-triggered exocytosis.

Life/Biological Sciences Presenter: Hernandez-Muñiz, Rayza Melissa

Mentor: Ríos-López, Neftalí

Title: Drought-driven reproduction and population fluctuation of the Puerto Rican Melodious Coquí, Eleutherodactylus wightmanae, from a mountain forest at the Sierra de Cayey

Authors: Rayza M. Hernandez Muñz (University of Puerto Rico- Humacao), Eliacim Agosto Torres (University of Puerto Rico- Humacao), Coralys Vicens López (University of Puerto Rico- Humacao), Ashley Bernardi Salinas (University of Puerto Rico- Humacao), Neftalí López Ríos (University of Puerto Rico- Humacao)

Abstract

The Melodious Coquí, Eleutherodactylus wightmanae, is a small frog (mean SVL = 20.2 mm) common in high elevation forests and inhabits forest leaf litter. In a study site at the Sierra de Cayey, the species is the second most abundant in the Eleutherodactylus assemblage, and shows a population variation and breeding phenology typical of other Eleutherodactylus from Puerto Rico: abundance and production of egg clutches increases with an increase in ambient temperature and rainfall, during months between 255

May and November, and decreases between December and April, months of lower temperature and less rainfall. Between year 2014 and 2015 (July 2014 and April 2015), an extreme ?11-mo drought–that equaled that between December 1974 and November 1975 in record–kept the amount of rainfall reaching to the leaf litter below that required to keep it a wet microenvironment suitable for frogs. Presumably, the extended and long period of dry leaf litter influence breeding activity in E. wightmanae: (1) in 2014, egg clutch production showed a significant 2nd degree polynomial function (egg clutches = - 0.5097Time2 + 5.6474Time - 3.4286, R=0.65453, p=0.0087), typical of a seasonal variation in egg clutch production, but (2) in 2015, egg clutch production showed a non-significant 2nd degree polynomial function (egg clutches = -0.1591Time2 + 2.2409Time + 1.1667, R=0.29075, p=0.1341), had fluctuated erratically but rather linearly since the end of the drought period (i.e. May 2015) to the end of 2015. We frequently found adults in holes in the ground, a behavior suggestive of hydric stress or animals living in their physiological limit for their rehydration capacity. We suggest that adults limited their breeding behavior (i.e. reduced calling, courtship, and mating) as water deficit in the leaf litter dropped below the minimum required for normal physiology and behavior in the species inhabiting the leaf litter (e.g., 1.5mm of rain reaching the leaf litter). A lag-time breeding phenology driven by this drought may have occurred, with consequences at the population level that remain to be documented in the near future.

Life/Biological Sciences Presenter: Jusino, Shirley

Mentor: Suarez, Edu

Title: Role of the Human Parainfluenza Virus Type 3 Fusion Machinery in Viral Growth in the Natural Host

Authors: Shirley Jusino (University of Puerto Rico in Ponce), Laura Palermo (Weill Cornell University), Anne Moscona (Weill Cornell University)

Abstract

Human parainfluenza virus type 3 (HPIV3) is a single-stranded, negative-sense RNA enveloped virus that causes severe respiratory diseases in children; including croup, bronchiolitis and pneumonia. HPIV3 infects its target cells by the coordinated action of the receptor binding protein hemagglutinin- neuraminidase (HN) and the fusion (F) envelope glycoprotein, which together comprise the molecular fusion machinery. Previous studies from our lab show that viruses bearing HN-F machinery that confer excellent growth in monolayer cultures cannot thrive in vivo. In turn, viruses that efficiently replicate in vivo- for example clinical isolates (CIs) - bear HN-F machinery that cannot cope with in vitro cell culture. Our aim is to characterize the fusion machinery properties of lung adapted HPIV3 virions. We hypothesized that circulating HPIV3 viruses (CIs) bear HN-F fusion machineries well suited to the natural environment. In order to characterize the different functions of the CIs HNs and F HPIV3, viral RNA was extracted from CIs and the genomic sequences were analyzed by deep sequencing techniques. The 256

cDNA encoding the CIs viral glycoproteins were inserted in expression vectors and assayed for expression levels by a biotinlyation assay. Additionally, neuraminidase activity was tested for all CIs HNs. Results were expressed as relative percentage of lab adapted -HPIV3 HN. Preliminary results suggest that HPIV3 CIs have a higher neuraminidase activity in comparison to lab adapted -HPIV3 HN and low fusogenicity. Overall, our results suggest that the fusion machinery of CIs is more stable and less readily activated than viruses adapted to growth in culture.

Life/Biological Sciences Presenter: Laureano, Stephanie M.

Mentor: Esteban, Ernesto

Title: An Analytical Study of Prostate-Specific Antigen Dynamics for Patients with Prostate Cancer and Benign Prostatic Hyperplasia

Authors: Ernesto P. Esteban (University of Puerto Rico Humacao Campus), Stephanie M. Laureano Figueroa (University of Puerto Rico Humacao Campus), Giovanni Deliz (University of Puerto Rico Humacao Campus), Jaileen Rivera (University of Puerto Rico Humacao Campus)

Abstract

The objectives of this research are two-fold. First, to carry out a novel quantitative studyof prostate- specific antigen (PSA) dynamics for patients with prostatic diseases, such asbenign prostatic hyperplasia (BPH) and localized prostate cancer (LPC). Secondly, toreduce the overdiagnosis and overtreatment of prostatic diseases by introducing as adiagnosis tool nomograms to predict LPC stage (T2a, T2b), as well as the progression ofPSA, and tumor size with age.

Life/Biological Sciences Presenter: López Pabón, María G.

Mentor: Berrios Villarini, Rosa

Title: Nephrolepis biserrata (Male) Fern Micropropagation

Authors: María G. López Pabón (Pontifical Catholic University of Puerto Rico) 257

Abstract

The Nephrolepis biserrata fern is a very important fern among horticultural growers and landscaping designers in Puerto Rico due to their vigorous growing properties. This research aims to develop a micropropagation methodology for massive propagation of the plant. Three trials of two disinfections treatments were tested with 15% Sodium hypochlorite for 15 minutes and 10% Sodium hypochlorite for 20 minutes followed by three distilled water rinses. In both treatments stolons are used as the explant in the first stage of culture initiation. The media used was Murashige and Skoog (1962) with vitamins, 0.30% sucrose and 0.7% agar. Tissues were separated into a control group and a testing group containing the growing hormones: 0.5 mg/l Naphthaleneacetic Acid (NAA) and 1.0 mg/l 6- benziladenine (BA). Each trial tested twenty tissues and were incubated at 23+/-25C, 50-70% RH and an approximate light intensity of 3000 lux. The most effective disinfection treatment was the treatment with 15% Sodium hypochlorite which showed fronds within seven days of incubation. A total of sixty fronds with green leaves were recovered from twenty tissues for an average of three fronds per run. The apical section of the stolon tissue showed the first green fronds growing within seven days of incubation. The 15% Sodium hypochlorite disinfection reported a ten percent contamination rate and a ninety percent tissue recovery. In the tissue treated with 10% Sodium Hypochlorite a twenty percent contamination rate was obtained and growth detected after nine days of incubation. Micropropagation protocols for massive propagation will follow.

Life/Biological Sciences Presenter: Lugo Monserrat, Carlos D.

Mentor: Acosta, Angel

Title: Efraín López Cave: Mesofauna Diversity and Inventory.

Authors: Carlos D. Lugo Monserrat (Department of Biology, University of Puerto Rico at Arecibo)

Abstract

Efraín López Cave is located in the north coast karst belt region of Puerto Rico, specifically in the municipality of Isabela, PR. The main objective of this study is to characterize the mesofauna organisms that live in the cave. For this study, two traps were used: i) cardboard trap (organisms used the voids as shelters) and ii) dead leaves trap (organisms used as food source). The traps were cleaned and the specimens were collected and classified by biological class/orders as a function of the depth of the cave. A statistical analysis was performed after the quantification and identification. The analysis consisted in Shannon index, species frequencies, relative abundance and species richness. Preliminary results show 19 different species. The understanding of this ecosystem will help us understand cave food webs and energy movement. Additionally, a population analysis can be an indicator of guanophillic fungi and bacteria that can be harmful to human health. In conclusion, we present the biodiversity of Efraín López 258

Cave as part of the complete characterization of the cave as a function of depth of the cave and spatial analysis results of the diverse mesofauna.

Life/Biological Sciences Presenters: Lugo-Cuevas, Josue J. Consuegra, Daisy

Mentor: Roig-Lopez, Jose L.

Title: The Effect of the Global Hypo-methylation in the Differentiation and Commitment of in Vitro Human Fetal Neural Stem Cells (hNSC).

Authors:

Abstract

It is imperative to have a clear understanding of how changes in the epigenetic status of a stem cell modify the gene expression profile that can result in an alteration in cell fate and determination. In this project we used primary cultures of hNSC derived from discarded human neural as a model system studying how in vitro demethylation affects their cellular commitment as well as differentiation towards neural or glial lineages. We hypothesized that DNA methylation will affect the in vitro differentiated cell population. Therefore, we conducted a double label indirect immunohistochemistry to stain the derived cells with glial and neuronal markers. The population was characterized by cell staining and quantify neuron (anti-Beta tubulin III) and glial cells (anti-GFAP and anti-Olig 2) with Image J software. Results suggested that the treatment with the hypo-methylating agent 5-Aza-2-Deoxycytidine significantly increases the percentage of neurons in one biological. However, a second biological sample shows no statically difference on the numbers of neurons and glial cells between control and experimental. Due to differences in labeling GFAP, we think that the current experimental strategy can bias the number of glial cells in the cultures. With this rationale we were using a second glial-oligodendrocyte lineage Olig 2 marker. These results will help predict changes in the commitment and differentiation of hNSC and could be applied to the development of cell replacement therapies.

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Life/Biological Sciences Presenter: Maldonado, Natalia

Mentor: Vazquez, Edwin

Title: Isolation and characterization of Agarase producing bacteria from tropical waters of Puerto Rico

Authors: Natalia Maldonado (University of Puerto Rico at Cayey), Edwin Vázquez (University of Puerto Rico at Cayey)

Abstract

There are currently several agarase-producing bacterial species that have been identified, mainly from marine water but some from freshwater and soil. Agarase is an enzyme responsible for the hydrolysis of agar as their primary source of carbon. Some agarases have been isolated and used in various research applications while others have been used for agar-derived oligosaccharide production. We describe three agarase-producing bacteria isolated from tropical marine waters in Puerto Rico. Samples were obtained from the South coast and plated on marine agar. Colonies that formed pits were purified by streaking at least twice in the same medium and incubated at 30°C. Isolates were characterized by pigment formation and morphological characteristics using Gram staining, followed by PCR amplification and sequencing of the 16s rRNA gene. At least three distinct bacterial species have been isolated belonging to the Rheineimera, Psychrobacter and Vibrio genera. We are currently isolating and purifying the enzymes to characterize them in terms of their specific activity and molecular weight. This will help us understand the relationship of these bacteria to other agarase producers isolated from other habitats.

Life/Biological Sciences Presenter: Martes Bermúdez, María C.

Mentor: Burrowes, Patricia

Title: Arboreality predicts infection loads of the pathogenic chytrid fungus in direct- developing frogs

Authors: Patricia A. Burrowes (Department of Biology, University of Puerto Rico, San Juan), María Celeste Martes (Department of Biology, University of Puerto Rico, San Juan) 260

Abstract

Retreat sites are important in determining disease dynamics because animals spend a large proportion of the day there. In Puerto Rico, direct developing frogs of the genus Eleutherodactylus utilize dark, humid retreats in the forest, where they remain inactive during the day. These sites are beneficial for the growth of the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (= Bd), which is a threat to amphibians around the world. The objective of this study was to determine if the microhabitats used by frogs when they are active are also associated to Bd infection level and prevalence. We analyzed data on Bd diagnosis of 157 adults and 122 juveniles of Eleutherodactylus coqui from the Palo Colorado forest in El Yunque, Puerto Rico. These frogs were sampled during ten years, from 2005 to 2015. The specific nocturnal microhabitat where frogs were found active was categorized as follows: forest floor, curled palm fronds in the floor, bromeliads above ground, and foliage or tree trunks ?50 cm above ground. We found that frogs in the forest floor had the greatest overall infection prevalence (73%). Comparatively, infection prevalence among frogs active in vegetation above ground was 55%, and the majority carried low Bd loads. To understand the effect of arboreality, we divided active sites in two major categories, above-ground and forest-floor, and found that individuals using perches in higher vegetation carry significantly lower Bd loads. Infection probability was significantly associated to height above ground, and the probability of infection for frogs utilizing microhabitats in the forest floor was twice as much as for those on arboreal substrate. These data provide evidence that "healthier" frogs utilize microhabitats that are higher above ground. There are several alternative explanations for these findings that may explain the complexity of disease dynamics in tropical ecosystems.

Life/Biological Sciences Presenter: Mesleh Shayeb, Shirin

Mentor: Jimenez, Braulio

Title: Establishing a method for Heavy metals in dry blood-spots from pre-term birth children in Puerto Rico

Authors: Shirin Mesleh Shayeb (University of Puerto Rico-Rio Piedras), Braulio Jimenez-velez Ph.d (University of Puerto Rico-Medical Sciences Campus), Hector Jirau Colon (University of Puerto Rico-Medical Sciences Campus)

Abstract

Heavy metal pollutants have become a global threat, accounting for a significant amount of health disparities' related to environmental causes. Trace metal toxicity has been correlated with a vast amount of developmental disorders, among which preterm birth is suspected. Some studies suggest that trace metals such as lead (Pb), cadmium (Cd), among others have a significant impact in the development of neurodevelopmental disorders such as Autism. Of utmost importance is the metabolic system that functions on the removal and clearance of these metals in biological tissues. Proteins such 261

as metallothioneine, and peptides such as Glutathione are responsible of regulating blood levels of these trace elements. Therefore, it is important to evaluate the relative levels of heavy metals in preterm birth children, and determine if there are significant differences when compared to levels in children born by normal birth. We will develop and optimize various protocols for the extraction of metals from dry blood spots samples taken from preterm birth and normal patients. These samples were analyzed using atomic absorption spectroscopy to determine the concentrations of four different heavy metals: lead (Pb), Cadmium (Cd), Aluminum (Al), and Nickel (Ni). DBS extracted samples were diluted in nitric acid combined with a matrix modifier to ensure stability during the extraction. Samples were measured for the four metals in preterm and none preterm patients. The resulting metal profiles are established for each group sample. We found higher levels of certain heavy metals in preterm children when compared to the normal population.

Life/Biological Sciences Presenter: Miranda Santiago, Angel

Mentor: Fasoli, Ezio

Title: Purification and characterization of a new esterase isolated from Cabo Rojo Salterns.

Authors: Angel Miranda (UPR Recinto de Humacao), Ezio Fasoli (UPR Recinto de Humacao), Steven Toro (UPR Recinto de Humacao), Mahmoud Matar (UPR Recinto de Humacao), Iris Flores (UPR Recinto de Humacao), Lilliam Casillas (UPR Recinto de Humacao)

Abstract

Purification and characterization of a new esterase isolated from Cabo Rojo Salterns

Angel Mirandaa, Mahmoud Matara, Steven Toroa , Iris Floresa, Lilliam Casillasb, and Ezio Fasolia a: Department of Chemistry University of Puerto Rico at Humacao b: Department of Biology University of Puerto Rico at Humacao

Esterases are used as biocatalysts for the hydrolytic resolution of important pharmaceutical intermediates with excellent chemo-, regio-, and stereo- selectivity. With the aim of finding new esterases highly stable in a broad range of organic solvents, 148 halophilic microorganisms from the salterns of Cabo Rojo (Puerto Rico) were cultivated in marine broth, and screened for esterase activity using p-nitrophenyl acetate as chromogenic substrate. Microorganisms positive for esterase were tested for activity and stability after 24 hours of incubation in a broad range of organic solvent/water mixtures at different ratios (15%, 30% and 50% (v/v)). A new halophilic esterase (MO-12) closely related to Bacillus subtilis was selected as the most promising enzyme for biotechnological application. The enzyme was characterized in terms stability to organic solvents, optimum salt concentration, pH and temperature. The crude enzymatic preparation was precipitated with ammonium sulphate, and after 262

dialysis and lyophilization it was purified using SDS-PAGE . The esterase band will be excised from the gel, eluted, and analyzed through mass spectroscopy.

Life/Biological Sciences Presenter: Montero Marín, Nichole E.

Mentor: Rivera, Harry

Title: Application of Synthetic Biology to Bioregenerative Life Support for Human Spaceflight: Assembling Metabolic Pathways to Optimize the Production of Vitamin K in E. coli

Authors: Montero Marín, Nichole E. (Inter-American University of Puerto Rico Bayamón Campus), Dougherty, Michael J. (Wyle Laboratories: Life Sciences Research NASA Ames Research Center, San José CA.)

Abstract

One of the potential applications of synthetic biology to bioregenerative life support for human spaceflight is the production of specific nutrients using genetically engineered microbes. One such candidate nutrient is vitamin K, an essential nutrient for humans that has potential issues with shelf life during long duration spaceflight. The summer project will involve doing molecular biology work; assembling pathways for gene expression to optimize production of vitamin K in E. coli. Additional work in modifying the host strain may also be undertaken. The work will provide experience in modern molecular biology methods applicable to metabolic engineering and many other areas of biomedical research. The objective of this project is the production of nutrients necessary for maintaining optimum health of astronauts on long duration missions. Vitamin K is essential in humans for blood coagulation and bone metabolism. Many bacteria have the ability to synthesize vitamin K, for example: B. cereus, B. subtilis, M. phlei and E. coli, which will be the focus of this project. The production of this molecule and other nutrients will require genetic engineering which to increase titers of specific nutrients that are important for human health. It will reach this objective by understanding E. coli metabolism. To begin, menaquinone or MK-8 (Vitamin K2) is naturally synthesized by E. coli, functioning in the electron transport chain during anaerobic respiration. On the other hand under aerobic conditions, E. coli synthetizes mainly ubiquinone-8, (Q-8). UbiCA is knocked out because is the precursor of the unwanted formation of Q-8. The genetic engineering strategy for this project will be the replacement of the native isoprenoid pathway of E. coli by mevalonate pathway. This metabolic pathway is synthesized by the sequential activity of eight (UbiE included) pathway enzymes: MenA, MenB, MenC, MenD, Men E, MenF, MenH and UbiE that are required for MK-8 synthesis.

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Life/Biological Sciences Presenter: Morales, Roberto

Mentor: Suarez-Martinez, Edu

Title: Role of Hippocampal Neurogenesis in Drug Addiction

Authors: Roberto Morales-silva (University of Puerto Rico at Ponce, Ponce), M.h. Galinato (Department of Neurosciences, University of California San Diego), C.d. Mandyam (Commitee on the Neurobiology of Addictive Disorders, The Scripps Research Institute)

Abstract

Methamphetamine, a psychostimulant and neurotoxic drug, has been shown to inhibit neurogenesis in the hippocampal region of the brain. The hippocampus is responsible for functions such as short-term and long-term memory, spatial orientation, and connecting emotions and senses. Also the hippocampus is involved in forming context-specific memories associated with reinstatement of drug-seeking. Neurogenesis is the process of stem-like precursor cells that proliferate into preneuronal progenitor cells that then differentiate into immature neurons that become granule cell neurons in the dentate gyrus. This process is impaired by methamphetamine and other drugs of abuse. The objective of this study is to determine the role of spontaneous neurogenesis in the dentate gyrus in drug addiction. To address this, we took a genetic approach using GFAP-TK transgenic animals to conditionally inhibit the process of neurogenesis. GFAP-TK+ and TK- (wild-type controls) were submitted to intravenous surgery to implant a catheter to the jugular vein for intravenous drug self-administration. The self- administration behavior was divided in 5 phases: drug acquisition, forced abstinence from drug (withdrawal), extinction, and context- and cue- induced reinstatement. During withdrawal GFAP-TK+ animals received valganciclovir diet (valcyte) to inhibit the proliferation and differentiation of neural precursor cells in the dentate gyrus. Controls received vehicle diet. One hour following reinstatement session, TK+ and TK- animals were sacrificed and the brain was processed for immunohistochemistry. Valcyte treatment in TK+ rats reduced the number of Ki-67 and NeuroD cells in the hippocampus compared to vehicle TK- controls. In parallel, TK+ rats showed impaired lever discrimination during extinction sessions and context-induced reinstatement, but not cue-induced reinstatement, indicating enhanced motivation to seek methamphetamine in the absence of the drug. These results indicate that hippocampal neurogenesis plays a role in extinguishing drug seeking behavior and suppresses motivation during context induced reinstatement.

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Life/Biological Sciences Presenter: Munet Colon, Clariliz

Mentor: Toranzos, Gary

Title: Inactivation of bacteria in Drinking Water by Pasteurization using Solar Irradiation in AquaPak®

Authors: Clariliz Munet Colón (UPR-RIO PIEDRAS), Emmanuel A. Carrasquillo Dones (UPR-RIO PIEDRAS), Nathalia C. Millán Borrero (University of Connecticut), John R. Donato Valle (UPR-RIO PIEDRAS), Tayyebe Aghaei (Solar Solution LLC), Gary A. Toranzos Soria (UPR- RIO PIEDRAS)

Abstract

Contaminated drinking water and the resulting diseases are one of the greatest problems of public health faced by man. Water contamination together with a lack of water treatment plants such as the case of developing countries or rural areas in industrialized countries present a unique public health problem. Increased access to improved microbiological water quality is one of the most important goals to improve overall public health. Pasteurization is one of the methods proposed to improve water quality and decrease the waterborne diseases. This method consists of the application of heat over a period of time and has proven to be highly effective in inactivating pathogenic microorganisms in products such as milk, juices and other types of liquid food and water. AquaPak® is a low-cost solar water pasteurizer that absorbs the IR wavelength of sunlight to heat the water during a period of time and inactivate the pathogenic microorganisms. The procedure was divided in two phases. During phase one, the AquaPaks® were filled with dechlorinated tap water and inoculated with E. coli and Enterococcus spp. (both strains are known to contain a lysogenized bacteriophage). The AquaPaks® were exposed to temperatures ranging from 63°C to 65°C, and samples were taken at increasing time intervals. Aquapaks® were removed from the heat and left at room temperature overnight. In the second phase, samples were taken every 2hrs for the detection of possible regrowth. Both microorganisms suffered a decrease from its initial bacterial load, starting from 1x10^8 CFU's (E. coli) and 1x10^7 CFU's (Enterococcus sp.) to a level where they could no longer be detected on the first day. We were surprised to detect regrowth on the second day. We were also surprised to detect the induction of lysogenic phages both days. These data indicate that solar pasteurization is very effective in the inactivation of high concentrations of indicator bacteria; however, the unexpected regrowth as well as the induction of the lysogenized phages brings into play other possible complications to this type of treatment. Future work will focus on this and the presentation of alternate methods to eliminate possible added health risks to public health.

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Life/Biological Sciences Presenter: Muriel-Mundo, Chris A

Mentor: Rodriguez-Bonano, Nydia

Title: Partial Characterization of pEc. 6.2 Isolated from Enterococccus casseliflavus from Recreational Waters in Puerto Rico

Authors: Chris A Muriel Mundo (Universidad Del Este), Nydia Rodriguez-bonano (Universidad Del Este)

Abstract

Plasmids are extrachromosomal DNA elements associated with the acquisition of new bacterial metabolic and virulent traits. It is well known that these elements contribute significantly to gene flux, evolution and adaptation of bacteria in the environment. Recently, we recovered an Enterococcus casseliflavus isolate harboring a 6.2 kb plasmid (pEC6.2) from a recreational water sample in Puerto Rico. The isolate exhibited susceptibility to 18 antibiotics tested including tetracycline, vancomycin and penicillin. It is unknown if pEC6.2 encodes for antibiotic resistance to other antibiotics besides the ones tested in the laboratory. However, it is also unknown whether pEC6.2 is related to any metabolic traits in E. casseliflavus. Therefore, the aim of this project was to characterized pEC6.2 and determine which traits are encoded by the plasmid. Prolonged subculturing without selective pressure, DNA extraction and agarose gel electrophoresis demonstrated that pEC6.2 is a stable and high copy number plasmid. Restriction enzyme digestions, cloning techniques using vector pZERO-2 and transformations in Escherichia coli Top10 cells were used to obtain a series of recombinant plasmids that allowed us to determine the partial sequence of pEC6.2. Based on sequence analysis, we have determined that there is no similarity between pEC6.2 and other known and characterized E. casseliflavus plasmids, like pEC30. We have not identified antibiotic resistant traits in pEC6.2. Yet, we have identified the replication region (rep) and it exhibits similarity with rep regions from other enterococcal plasmids. Well characterized plasmids from other Enterococcus spp. do not share the same size, stability and copy number with pEC6.2. For these reasons, we believe that pEC6.2 is a new enterococcal plasmid. More recently, we have perform next generation sequencing for pEC6.2 and de novo assembly of pEC6.2 is currently in progress.

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Life/Biological Sciences Presenters: Nieves Ríos, Christian J. Alvarez Falcón, Samuel A.

Mentor: Garcia Arraras, Jose

Title: The mesentery nervous system and the changes it undergoes during intestinal regeneration in an invertebrate deuterostome

Authors: José E. García-arrarás (University of Puerto Rico, Rio Piedras Campus), Christian J. Nieves-ríos (University of Puerto Rico, Rio Piedras Campus), Samuel A. Álvarez-falcón (University of Puerto Rico, Rio Piedras Campus)

Abstract

The mesenterial tissues play a key anatomical role in the connections between the viscera and the rest of the organism. They serve as the physical substrate for nerves connecting the visceral nervous components to the central nervous system. Although the mesenterial nervous system component has been well described in vertebrates, particularly in mammals, a description in other deuterostomes is lacking. It is crucial to describe this component in view that the nervous system has been shown to play a role in many regenerative events. Thus, our main focus is to describe the nervous component of the intestinal mesentery in the sea cucumber Holothuria glaberrima, and the changes that it endures during the regeneration progress. H. glaberrima is an echinoderm with the ability to regenerate its internal organs. Previous studies demonstrate that in this species intestinal regeneration depends on the mesentery. We have used immunohistochemistry and tissue whole mounts to describe the nervous components within the mesentery of normal or uneviscerated and regenerating animals. Most of the results were obtained using the RN1 antibody, a neuronal marker. Nerve fibers and cells were described and quantified using UV microscope. Our results conclude that, the orientations of nerve fibers in both mesotheliums are perpendicular to those in the connective tissue, and that both mesotheliums are anatomically similar regarding their quantity and distribution.Our experiments show that most of the nerve fibers within the mesentery remain, during the regenerative process, with two major changes: there is a disorganization and retraction of nerve fibers near the tip of the mesentery during the first days of regeneration, and they also accumulate close to the body wall. Our results present descriptive and quantitative evidence of the anatomical distribution of nerve fibers in the mesentery, and provide useful techniques for studies of the nervous system in intestinal regeneration of sea cucumbers. Research was funded by NSF (IOS-0842870), NIH (R15NS01686) and the University of Puerto Rico. JMR was funded by NIH-MBRS (RISE) program of the University of Puerto Rico.

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Life/Biological Sciences Presenter: Nieves-Rosado, Hector

Mentor: Rios Velazquez, Carlos

Title: Using Multiplex-PCR to Detect Virulence Factor Genes from Vibrio parahaemolyticus isolates from the Oyster Crassostrea rhizophorae and Clam Phacoides pectinatus from Puerto Rico

Authors: Hector Nieves-rosado (University of Puerto Rico- Mayaguez), Karlen Correa-velez (University of Puerto Rico- Mayaguez), Carlos Rios-velazquez (University of Puerto Rico- Mayaguez)

Abstract

Infections with pathogenic strains of V. parahaemolyticus is the leading cause of food-borne acute gastroenteritis worldwide. The Center for Disease Control and Prevention (CDC) in 2013 reported that large outbreaks of V. parahaemolyticus in USA have occurred even when active monitoring of these strain in oysters from suspected sites were low. Therefore, detection of V. parahaemolyticus from shellfish and in the harvesting waters do not represent an appropriate way to ensure public health if pathogenic markers are not taken into account when characterizing this strain. The Food and Drug Administration (FDA) has recommended the use of PCR, DNA hybridization and a modified version of PCR, known as Multiplex-PCR for detection of pathogens in food. The Multiplex-PCR involves the use of more than one set of primers for amplification of several different DNA sequences simultaneously in one polymerase chain reaction. In Puerto Rico, there are no regulatory agencies that control the handling and quality conditions for selling raw shellfish such as oysters and clams. Detection of pathogenic strains of V. parahaemolyticus from environmental samples can allow us to potentially predict and compare outbreaks in PR with other countries and will develop awareness to local population about the health issues that can potentially be caused by eating raw seafood. Our goal is to determine the presence of pathogenicity associated genes in V. parahaemolyticus isolates from the oyster Crassostrea rhizophorae and the clam Phacoides pectinatus from the southwest coast of PR. DNA extractions were performed from presumptive V. parahaemolyticus strains previously isolated using TCBS media. The extracted DNA was processed following the standardized multiplex-PCR protocol recommended by the FDA in the Bacteriological Analytical Manual. Multiplex PCR was performed for the amplification of tdh (270bp) and trh (500bp) genes associated with pathogenic activity, and tlh (450bp) a specie specific marker. V. parahaemolyticus O4:K12 strain 48057 (NR-21990) ATCC® was used as a positive control. A total 3 samples for each oyster and clam were obtained. All resulted positive to V. parahaemolyticus based on the presence of a tlh gene amplicon and none of them resulted to be pathogenic due to the absence of a tdh and trh amplicons by modified electrophoresis in a 3% agarose gel. The isolates analyzed in this study lack pathogenicity markers and might not represent a risk to the population in terms of V. parahaemolyticus' associated infections. Future monitoring is necessary using this molecular techniques to detect the pathogenic levels of any V. parahaemolyticus isolated from the coasts of Puerto Rico.

268

Life/Biological Sciences Presenter: Orriz Ithier, Tara Marina

Mentor: Jimenez, Carlos

Title: Effects of PKM? inhibitor (ZIP) on the initiation and maintenance of cocaine sensitization

Authors: Tara Marina Ortiz-ithier (Department of Natural Sciences, University of Sacred Heart, San Juan, P.R.), Ana Vaquer-alicea (Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, P.R.), Rafael Vazquez-torres (Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, P.R.), Bermary Santos-vera (Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, P.R.), Carlos A. Jimenez-rivera (Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, P.R.)

Abstract

Cocaine addiction induces long-lasting alterations in the mesocorticolimbic system; some of which may be mediated by the mechanisms of long-term potentiation (LTP). Persistent phosphorylation by protein kinase M zeta (PKM?) mediates the maintenance of late-LTP (L-LTP). The myristoylated z- pseudosubstrate inhibitory peptide (ZIP) selectively inhibits atypical PKCs, including PKM?, and reverses established L-LTP. Previous laboratory data showed that ZIP microinjection in the ventral tegmental area (VTA) (important for initiation) on day 5 of a cocaine behavioral sensitization protocol blocked initiation of sensitization but not expression. We hypothesized that uninterrupted neural signaling from the VTA to the nucleus accumbens (NAc) (important for expression) for 5 days before inhibiting PKM?, triggered plastic changes in the NAc. In accordance with this hypothesis, ZIP microinjections into the NAc after 7 days of withdrawal blocked expression. These data indicate that VTA LTP plays a role in the initiation of sensitization and NAc LTP allows sensitization expression. To elucidate if VTA LTP is essential for plasticity changes in the NAc to occur, we continuously interrupted VTA LTP formation and looked for changes in expression. For this, male Sprague-Dawley rats (250g) were stereotaxically implanted with bilateral cannulas into the VTA and were given daily ZIP microinjections for 5 days, 6 hours after cocaine i.p. injection followed by a 7 day withdrawal period and a cocaine challenge. Results showed a decrease in total and stereotypic locomotion on day 5, but not on challenge day. This suggests that PKM? is important but not essential for the initiation phase and that NAc neuroadaptations can develop independently of VTA LTP. In order to see if these neuroadaptations in the NAc can be naturally restored once interrupted, we inhibited PKM? a week after a withdrawal period and allowed another 7 days of withdrawal. A cocaine challenge was given on day 20. We observed a persistent decrease in total and stereotypic locomotion by day 20, indicating NAc LTP disruptions during the maintenance phase of the cocaine sensitization protocol are long-lasting. Further studies regarding PKM?'s role in cocaine-induced LTP formation in the reward circuit, will shed some light into the pathological mechanisms that underlie cocaine addiction. 269

This project was supported in part by grants from NIHGM (2SC1GM084854-05A1), the National Center for Research Resources (5R25GM061838-15, 2G12-RR003051) and the National Institute on Minority Health and Health Disparities (8G12-MD007600) from the National Institutes of Health.

Life/Biological Sciences Presenter: Ortiz, Ricardo

Mentor: Rios Velazquez, Carlos

Title: Detection and identification of human lungs proteins that binds Bacillus anthracis lethal factor using T7-Phage Display

Authors: Ricardo Ortiz Loubriel (University of Puerto Rico, Mayaguez Campus), Carlos Rios- velazquez (University of Puerto Rico, Mayaguez Campus)

Abstract

Anthrax is a serious infectious disease caused by gram-positive, rod-shaped bacteria known as Bacillus anthracis (CDC, 2015). After a bio-terrorist attack on 2001, B. anthracis has become a serious target to biomedical research. B. anthracis infections have been noticed in three types, the cutaneous, the inhalation and the gastrointestinal anthrax. Anthrax toxin action is due to a tripartite protein components protective antigen (PA), lethal toxin (LT) and edema factor (EF). While the virulence of LF causes death in the cell by the inhibition of the MAPK pathway, which leads the cell to apoptosis, the interaction with other protein families has been proposed. For its virulence factor, understanding of anthrax lethal toxin and its interaction with new ligands is an important question that needs to be answer. This project is focused on identification of LF specific interaction proteins using the combinatorial chemistry approach named T7 Phage Display. This technique allowed us to identify protein-protein interaction between LF and human peptides, by observing cell lysis after infection. Human Lung cDNA libraries expressed on the surface of a T7 Phage were exposed to wild type and mutant LF as a target. After a biopanning process, the T7 phages that remained bound to the target and detected by overlay assay were selected for further molecular analysis. After three biopannings, 1 x 103 plaques with putative displayed interaction peptides were found suggesting the presence of putative interaction peptides. A total of thirty plaques were isolated, fifteen from each type of LF. Sequencing and bioinformatics are in progress to determine the identity of the selected peptides and protein family where they belong.

270

Life/Biological Sciences Presenter: Pacheco Lebrón, Amanda I.

Mentor: Washington, A. Valance

Title: Differential Responses of Bone Marrow-Derived Macrophages To Lipopolysaccharide In the Treml1 Null Mouse

Authors: Amanda I. Pacheco Lebrón (Universidad de Puerto Rico, Rio Piedras), Marieli González- cotto (Universidad Central del Caribe), Anthony Valance Washington (Universidad de Puerto Rico, Rio Piedras)

Abstract

Cardiovascular diseases remain one of the leading causes of death worldwide. Atherosclerosis, the hardening and narrowing of the arteries, is a chronic inflammatory disease driven by a crosstalk of signaling molecules between circulating immune cells and the vessel wall. In the classic view of the disease, hyperlipidemia initiates an inflammatory cascade that promotes macrophage infiltration into the vessel wall leading to a feedback mechanism which exacerbates lesion growth and ultimately, atherothrombosis. Despite recent advances in its understanding, the underlying mechanisms fine-tuning these responses remain incompletely understood. Our laboratory has characterized a novel atherosclerotic mice model, in which deletion of the platelet receptor Triggering Receptor Expressed in Myeloid cells (TREM)-like Transcript 1 (TLT-1) on a apolipoprotein E (apoe-/-/treml1-/-) background dampens early macrophage infiltration into the vessel wall. This leads to decreased lesion size, instability, and calcification of atherosclerotic lesions. We have demonstrated that one of the mechanisms for dampened lesion progression is decreased platelet activation and we hypothesize that the macrophage infiltration differences may also be due to fundamental differences in macrophage phenotypic functions. In order to further define the mechanism by which TLT-1 modulates macrophage infiltration, we analyzed macrophage function in vitro. Analysis of bone marrow-derived macrophages (BMDM) from apoe-/-/treml1-/- and apoe-/-/treml1-/+ mice revealed no significant differences in the phagocytic function of long chain fatty acids in vitro. However, analysis of basal levels of monocyte chemoattractant protein-1 (MCP1), a key chemokine regulating monocyte infiltration, were significantly decreased in the apoe-/-/treml1-/- BMDM supernatants. Accordingly, levels of Interleukin 6 (IL6) and Interleukin 10 (IL10) were significantly decreased in the apoe-/-/treml1-/- BMDM supernatants after two hours of lipopolysaccharide (LPS) stimulation (p

271

Life/Biological Sciences Presenter: Padilla Del Valle, Ricky

Mentor: Rios Velazquez, Carlos

Title: Accessing Antibiotic Resistance in Pristine vs Anthropogenic Impacted Environments Using Metagenomics

Authors: Ricky Padilla Del Valle (University of Puerto Rico at Mayaguez)

Abstract

The outbreak of infectious diseases with Antibiotic Resistance (AR) has threat the first line of the medical defense in the world. During years, classic microbiology tried to resolve this problem by producing new antibiotics but its continuous overuse only increased the frequency of AR pathogenic infections. In other hand, functional metagenomic analysis have reveal that world's ecosystems have a diverse collection of AR genes. The purpose of our research was to generate metagenomic libraries (ML) from two different types of conditions: from a pristine environment and a human anthropogenic impacted ecosystem (HAIE). Then, explore for AR genes against ampicillin, kanamycin and tetracycline.

Two ML from compost, a vegetable waste and a human biosolid, were generated (representing HAIE) and two ML from soils of Isla de Mona, PR were also generated (representing pristine environment). The high molecular weight (40kbp) DNA of each one was end-repaired, electro eluted, and ligated into the fosmid vector pCCFOS1, then, transduced to Escherichia coli Epi300-T1R using T1 bacteriophage. The Minimal Inhibitory Concentration (MIC) of ampicillin, kanamycin and tetracycline were determined. The AR clones from the libraries were isolated by selection on culture media supplemented with 1X-10X MIC of each antibiotic separately. While many clones in the ML of composts showed AR to 1X-10X MIC of ampicillin, no AR to ampicillin was detected in the clones from the pristine environment. These results represents that HAIE are potential reservoirs of ?-lactams AR in contrast to the pristine environment. Further analysis will confirm AR against the other two antibiotics.

Life/Biological Sciences Presenter: Pagán Rolón, Karelis

Mentor: Chiesa, Ricardo

Title: Ethanol-Induced locomotion in Drosophila melanogaster is decreased by the administration of an organic extract of the seaweed Stypopodium zonale

Authors: Adbiel Rodriguez Santiago (UPR Cayey), Elba L. Gonzalez Marquez (UPR Cayey), Almarely L. Berrios Negron (UPR Cayey), Romina Gonzalez Pons (UPR Cayey) 272

Abstract

The objective of this project is to determine if crude organic extracts of brown algae, encountered in Puerto Rican coasts, show anxiolytic-like properties and are capable of decreasing ethanol-induced hyper-locomotion in Drosophila melanogaster. We have selected this model since it offers several advantages for behavioral and pharmacological studies due to its similarities in cellular and neurobiological processes with vertebrate organisms. In order to study drug-induced hyper-locomotion and anxiety related behaviors in flies we administer ethanol, which increases locomotion in our model. This behavior serves as a paradigm to measure the capacity of the extract to decrease locomotion and evoke any other anxiolytic-like effects in Drosophila. To study the possible anxiolytic-like effects in flies exposed to ethanol, the model was given a organic extract of Stypopodium zonale over a two week period. After the exposure to the food containing the organic extract of Stypopodium zonale, the effects in the behavior in locomotion were evaluated by video recordings and quantitative analysis. Preliminary data shows a decrease in locomotion in Drosophila melanogaster that was given the extract before the ethanol exposure. Additional repetitions of the experiment are planned and needed for the validation of the effect in the behavior on our model and to perform a statistical analysis. If the capacity of this extract to counter-effect ethanol-induced hyper-locomotion and to produce anxiolytic-like effects is further validated, this project opens possibilities to understand and create new pharmacological treatments for drug-induced hyper-locomotion and anxiety-related behaviors.

Life/Biological Sciences Presenter: Paniagua Delgado, Jenniffer

Mentor: Fant, Jeremie

Title: Hidden complexity: The population genetic structure of Hyles lineata

Authors: Jenniffer Paniagua Delgado (University of Puerto Rico, Rio Piedras), Rick Overson (Chicago Botanic Garden), Jeremie Fant (Chicago Botanic Garden)

Abstract

Hyles lineata, commonly known as the White-lined Sphinx, plays a fundamental part in the reproduction of many moth-pollinated flora across North America. This species is known to be a long distances traveler which makes it peculiar between moths. Consequently, this make us question how can this affect their behavioral patterns. In this study, we are focusing on understanding the genetic structure of the population of H. lineata through the Western United States. To accomplish this, we use mtDNA and nuclear markers to comprehend the behavioral patterns of the species; expecting one of two different hypothesis. One of this hypothesis used as a model the population genetic structure of Hyles euphorbiae, that has been found in their behavioral patterns an association with sexuality; females having a tendency to be more faithful to their habitat than males. The second hypothesis is based on the migrational patterns of the Monarchs, who are known for being long distances traveler like the White- 273

lined Sphinx. Despite the fact that monarchs have this unique behavioral pattern, in many studies they present low genetic structure; which can be interpreted as they being a huge population across North America that are breeding philopatric. Using basic protocols for sequencing, we found high mtDNA diversity and genetic structure in three of the six states that we sampled. This means that in contrast to the monarchs, H. lineata has a complex structure in maternally inherited mtDNA marker as in comparison to the structure in the nuclear marker. This suggest that males disperse further distances and females tend to be more philopatric, which was expected if H. lineata follows the genetic structures of the European sphingid H. euphorbiae.

Life/Biological Sciences Presenters: Pares Torres, Olivia Viaud-dimanche Dorsainvil, Louis

Mentor: Guzmán Blas, Rolando

Title: Juvenile Toxin potency on HeLa cells

Authors: Olivia Pares Torres (University of Sacred Heart (USC)), Louis Viaud-dimanche Dorsainvil (University of Sacred Heart (USC)), Dr. Jose Luis Quiñones (University of Sacred Heart (USC))

Abstract

Lionfish toxin has been tested by (M Sri Balasubashini, 2006) to induce apoptosis in HeLa cells. This study will compare the peptide of the adult and juvenile lionfish antitumor effects on HeLa cells. Cancer cell cultures have been useful models to evaluate gene expression and to establish in vitro experiments aimed at the control of tumor cell growth (Akiva S Cohen, 1989). The cell lines will be maintained in (DMEM) supplemented with 10% Fetal calf serum, amphotericin (3 ?g/ml), gentamycin (400 ?g/ml), streptomycin (250 ?g/ml), penicillin (250 units/ml) in a carbon dioxide incubator at 5% CO2 (M Sri Balasubashini, 2006).The fish will be captured and preserved in ice. The extraction will be carried out using (Akiva S Cohen, 1989) and the toxin will then be purified. The cells will all have the same concentration of purified toxin and will be analyzed every 4 hours. Each test will consist of 2 groups. The first group will have healthy cells and HeLa cells, both with juvenile peptide. The second group will have healthy cells and HeLa cells, both with adult peptide. There will also be a control group composed of HeLa cells without peptide. Apoptosis will be analyzed using an ApoDETECT V-FITC with fluorescence microscope.

274

Life/Biological Sciences Presenter: Parham, Louis

Mentor: Tinoco, Arthur

Title: Exploring possible strategies of Reactive Oxygen Species induction through the formation of insoluble titanium based compounds inside cancer cells

Authors: Louis R. Parham (University of Puerto Rico, Rio Piedras Campus), Mallesh Pandrala (University of Puerto Rico, Rio Piedras Campus), Arthur D. Tinoco (University of Puerto Rico, Rio Piedras Campus)

Abstract

Titanium is found abundantly in the human body, this is due to either the ingestion of it in our diet or through its use in dental and orthopedic prosthetics. However, due to the fact that it can leach from such artificial implants, ongoing studies are trying to determine possible detrimental health problems associated with elevated concentrations of titanium. Its poor solubility in water is the main reasons why it has been disregarded as a potential threat, seeing as it implies biological inertness. One of the concerns with respect to titanium in the body is the ability of its insoluble form, titanium dioxide, to generate reactive oxygen species (ROS) which can interfere with biological processes and cause cell structure damage due to oxidative stress. Targeting the formation of such species in cancer cells provides a baseline for the development of various anticancer drug designs. My project focuses on working on exploiting human serum albumin (HSA) and its metal binding property as a transport method for titanium as well as titanium complexes such as Titanocene Dichloride (Cp2TiCl2) into cancer cells due to the known ability of this protein for preventing hydrolysis of these complexes at physiological pH. When titanocene dichloride is hydrolyzed its chlorine (Cl) and "Cp" rings dissociate and titanium precipitates as titanium dioxide, this implies that the prodrug properties of titanocene dichloride reside in the metal itself and not necessarily in the intact complex. Due to the fact that cancer cells require a higher rate of metabolism, it is expected that within the cell HSA will be subject to an enzymatic breakdown, exposing the titanocene complex to aqueous surroundings, thus promoting its precipitation. Through our research work we explored the intracellular formation of titanium oxides since such compounds can be UV activated to induce the formation of ROS. In this study we observed the effect of cancer cell lysate in solutions of HSA bound to titanocene dichloride. Through colorimetric assays we were able to demonstrate that titanium concentrations decreased in the presence of cell lysate, moreover, titanium concentration decrease was most prominent at higher concentrations of cell lysate. Further analysis through EDS were able to help us confirm the presence of a titanium compound in our sample precipitate. Future works will be directed towards analyzing the form of the titanium compound that is precipitating in order to determine if the formation of ROS can be induced.

275

Life/Biological Sciences Presenter: Peguero-Pereira, Eveliz

Mentor: Garcia Arraras, Jose

Title: Characterization of Retinoic acid Pathway Components in Sea Cucumber Holothuria glaberrima

Authors: Eveliz Peguero-pereira (University of Puerto Rico at Rio Piedras), Jorge Viera-vera (University of Puerto Rico at Rio Piedras), José E. García-arrarás (University of Puerto Rico at Rio Piedras)

Abstract

Regeneration is a regulated process that consists in restoring wounds or lost tissue. In many organisms where it takes place, regeneration is modulated by retinoic acid, a signaling molecule that serves as a transcription factor through a nuclear-receptor mediated pathway. The role of this pathway remains unknown in echinoderm regeneration. As a first step to determine if retinoic acid is involved in the regeneration of echinoderm tissues, we have characterized two components of the signaling pathway in the sea cucumber Holothuria glaberrima: the enzymes Raldh4 and Cyp26. Bioinformatics tools were used to find sequences that corresponded to these enzymes in the sea cucumber. For Raldh4, we had previously confirmed its open reading frame (ORF). We blasted the ORF in the sea cucumber database to find its untranslated regions. For Cyp26, we blasted a sea urchin sequence of the enzyme to our sea cucumber database. We designed primers and performed Polymerase Chain Reactions (PCRs) with a mix of mRNA from normal and regenerating animals as template. The successful products were sent to sequence and confirmed we had the expected sequences. The sea cucumber enzymes showed over 40% identity and 60% similarity to equivalents of these enzymes in evolutively similar animals such as the sea urchin Stronglyocentrotus purpuratus. In conclusion, our data shows that these two enzymes are present in the sea cucumber genome and are expressed during regenerative processes. This is the first step towards performing expression level studies of these enzymes to deduct if retinoic acid plays a role during echinoderm regeneration. Research was funded by NSF (IOS-0842870), NIH (R15NS01686) and the University of Puerto Rico. EPP was funded by the NIH-MBRS-RISE(5R25GM061151-14) program of the University of Puerto Rico.

276

Life/Biological Sciences Presenter: Perez Medina, Kiara

Mentor: Maldonado, Sandra

Title: Molecular analysis of endophytes in Oplonia spinosa an endemic plant in Guajataca, Puerto Rico.

Authors: Kiara L. Pérez Medina (University of Puerto Rico, Mayaguez campus), Hector J. Rivera Jiménez (University of Puerto Rico, Mayaguez campus)

Abstract

Fungal endophytes cause infections within tissues of healthy plants. The infection could be parasitic or symbiotic depending on the host plant. A study on Oplonia spinosa was conducted to identify endophytes associated to the population of this endemic plant in Guajataca, Puerto Rico. Healthy leaves were surface sterilized using ethanol (70%) and sodium hypochlorite (0.15%). The leaf fragments were sectioned in apex, center and base inoculated in Potato Dextrose Agar and incubated for two weeks at 22?C. Amplification and sequencing of 18S rRDNA using the ITS1 and ITS4 primers was performed on the endophytes isolated from Oplonia spinosa. The sequencing findings were Neopestolatiopsis, Colletotrichum gleosporoides, Nigrospora sphaerica, Pleroporales 99%ID and Hypocreales 90% ID.

Life/Biological Sciences Presenter: Pichardo Velázquez, Julian

Mentor: Santiago, Eugenio

Title: Estudio cuantitativo de la morfología foliar de dos especies de Tabebuia de los bosques nublados de Puerto Rico

Authors:

Abstract

Tabebuia es un género de árboles neotropicales pertenecientes a la familia Bignonaceae que exhibe una impresionante diversificación y para su clasificación, se utiliza un conjunto de caracteres morfológicos diagnósticos que permiten diferenciar las especies dentro de este género. En ocasiones los caracteres no son lo suficientemente distintivos para diferenciar algunas de sus especies y ese es el caso de Tabebuia rigida y Tabebuia schumanniana. En esta investigación se propone analizar cuantitativamente los caracteres diagnósticos de T. rigida y T. schumanniana para determinar si los mismos no son significativamente diferentes, o si por el contrario exhiben gran diferencia entre sí. La hipotesis a ser 277

evaluada es, "Si no ha habido aislamiento geográfico marcado entre las poblaciones de Tabebuia de los bosques nublados de la Cordillera Central y la Sierra de Luquillo, entonces se espera que no exista variabilidad morfológica marcada entre los arboles de estas dos regiones, porque no ha habido divergencia evolutiva suficiente entre las poblaciones. Por lo tanto, existe una sola especie de Tabebuia en los bosques nublados de la Cordillera Central y la Sierra de Luquillo". Esta hipótesis se pondrá a prueba haciendo un análisis estadístico para obtener el coeficiente de correlación de Pearson entre las variables para medir la relación entre estas utilizando datos de mediciones realizadas a hojas de T. rigida y T. schumanniana obtenidas de muestras recolectadas en el campo y otras ya depositadas en los herbarios. Con este trabajo se busca entender los límites taxonómicos de algunas de las especies de Tabebuia endémicas de Puerto Rico y así refinar el conocimiento sobre la diversidad de este género en el Caribe.

Life/Biological Sciences Presenter: Pichardo-González, Priamo A

Mentor: Vazquez, Edwin

Title: Isolation, Characterization and Genomic Analysis of Priamo, a Novel Soil Mycobacteriophage from Gurabo, Puerto Rico.

Authors: Priamo A. Pichardo-gonzalez (University of Puerto Rico at Cayey), Xavier D. Ortiz-torres (University of Puerto Rico at Cayey), Mariceli Fernandez-martinez (University of Puerto Rico at Cayey), Natalia Maldonado-vazquez (University of Puerto Rico at Cayey)

Abstract

We report on the isolation, characterization and genomic analysis of Priamo, a novel mycobacteriophage from Gurabo, Puerto Rico. A soil sample was collected and enriched in special media with Mycobacterium smegmatis serving as a host. Samples were filtered with a 0.2 um membrane and the filtrate used to streak a plate that was overlaid with top agar containing the host cells. After plaques were observed, a phage agar plug was suspended in phage buffer and used to streak a new plate as before. This was repeated at least three times to purify the plaques. A high titer phage lysate was then prepared with a titer of 5.9 X 10^11 PFU/mL. Phage genomic DNA was purified using a DNA extraction column and digested with BamH1, EcoRI, ClaI, HaeI and HindIII. The resulting fragments were separated in a 1% agarose gel. The mycobacteriophage coat proteins were precipitated and analyzed using 1D polyacrylamide gel electrophoresis. The migration patterns of the DNA digestion products and the capsid components were used to compare with other isolated phages to ascertain its uniqueness. Genomic DNA was sequenced at the Pittsburgh Bacteriophage Institute using an Illumina sequencer. Sequence analysis shows that its genome is 51633 pb long, with a GC content of 61.4%, and classified as a cluster A6 mycobacteriophage. Preliminary gene annotation analyses predict 96 open reading frames and three tRNA genes. BLAST sequence alignment shows a 97% homology to cluster A6 278

phages EricB, isolated in Virginia and 96% homology with DaVinci, from Pennsylvania and VohminGhazi from Texas. Comparison of the genome sequence and architecture of phages provides insights into phage genome evolution including the processes of gene flux by horizontal genetic exchange. This work is supported by the Howard Hughes Medical Institute and the University of Puerto Rico at Cayey.

Life/Biological Sciences Presenter: Ponce De León Guzmán, Solimar L.

Mentor: Griebenow, Kai

Title: "Mutation of the omega-loop impacts stability and function of human cytochrome c"

Authors: Manoj Saxena (University of Puerto Rico, Rio Piedras Campus), Solimar L. Ponce De León-guzmán (University of Puerto Rico, Rio Piedras Campus), Josell Ramirez-paz (University of Puerto Rico, Rio Piedras Campus), Rohit K. Sharma (University of Puerto Rico, Rio Piedras Campus), Kai Griebenow (University of Puerto Rico, Rio Piedras Campus)

Abstract

Cytochrome c (cyt c) is an evolutionarily conserved globular protein that is often used as a model for studying protein stability and folding. Although its role as an electron carrier in the electron transport chain is well documented, findings related to its role as a protein that it could trigger apoptosis upon its release from mitochondria has reignited interest in cyt c structure and function.

We have studied the role of two alanine-to-cys mutations that were designed in the omega loop of the cytochrome c on cyt c apoptotic function. It is important to note that natural variants of the omega loop in humans have been linked to diseases, e.g., G to S mutation at residue 42 occurs in thrombocytopenia. Also, in vitro studies have shown that mutations in this loop impact the apoptotic function of cyt c. Protein stability data obtained by differential scanning calorimetry suggest that the A44C and A51C mutants are less stable than the wild-type protein with A44C being least stable while A51C displays intermediate stability between A44C and the wild type. Additionally, the preliminary results from the in vitro cell-free caspase 3 activity assay indicate altered apoptotic activities of these mutants. Results from the secondary structure comparison using CD suggests that the secondary structure of these mutants is not changed much while a change in the tertiary structure is clearly evident. We propose that on mutating Ala to Cys at these locations a possible conformational change occurs which could facilitate the change in caspase activity while decreasing the overall stability of the protein.

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Life/Biological Sciences Presenter: Raimundi Raimundi, Antonio T.

Mentor: González, Carlos

Title: Role of p38 MAPK on Interleukin-3 mRNA subcellular localization upon T-cell activation

Authors: Antonio T. Raimundí Raimundí (UPR-RIO PIEDRAS), Stephanie Rivera Rivera (UPR-RIO PIEDRAS), Maria F. Duque Osorno (UPR-RIO PIEDRAS), Carlos I. González Vargas (UPR- RIO PIEDRAS)

Abstract

Interleukin-3 (IL-3) is a pro-inflammatory cytokine secreted by helper T-cells upon stimulation. It has been shown that IL-3 supports proliferation and differentiation of the myeloid cells. Deregulation of this cytokine has been implicated in chronic inflammation and is sometimes overexpressed in many diseases such as coronary artery disease, atherosclerosis, schizophrenia, asthma and mostly in Multiple Myeloma. Its mRNA is expressed upon T-cell activation. Previous results from our laboratory demonstrated that the post-transcriptional regulation of IL-3 depends on the presence of AREs (Adenosine and Uridine-Rich Elements) in the 3' UTR of the mRNA. The p38 MAPK signaling cascade is an important component of the inflammatory signal and also plays a role in the regulation of ARE- containing mRNAs. To determine the spatial localization of the endogenous IL-3 mRNA, nuclear and cytoplasmic RNA was extracted from activated Jurkat T-cells at 0, 0.5, 6 and 12 hour time-points. These RNA extractions were obtained from cells treated with a p38 inhibitor (SB202190) or without the inhibitor. qPCR analysis was performed using primers for IL-3 mRNA and Granulocyte Macrophage- Colony Stimulating Factor (GM-CSF). Initial results from the qPCR assay revealed the appearance of primer dimers for IL-3 and GM-CSF, and a signal for the 18S mRNA (positive control). Ongoing experiments to optimize the qPCR protocol (e.g., using different cDNA concentrations, annealing temperatures and/or different primers) are necessary in order to obtain a positive signal for both IL-3 and GM-CSF transcripts. Elucidating the spatial localization of the IL-3 mRNA will allow us to better understand the post-transcriptional control of IL-3 and its role in inflammation and cancer.

280

Life/Biological Sciences Presenter: Ramirez Aponte, Edwin G.

Mentor: Martinez-Cruzado, Juan

Title: Characterization of the Z-Chromosome of the Puerto Rican Parrot (Amazona vittata)

Authors: Edwin G. Ramírez-aponte (Department of Biology, University of Puerto Rico at Mayagüez), Juan C. Martínez-cruzado (Department of Biology, University of Puerto Rico at Mayagüez)

Abstract

Puerto Rican parrot (Amazona vittata) genome data became publicly available thanks to the community effort of the people of Puerto Rico. To advance the description of rearrangements, conserved regions, protein-coding genes and other important protein and gene features, we are focusing on sex chromosome Z from the latest genome assembly (http://genomes.uprm.edu/parrot). Some annotation resources and tools used for this work are: Stand-alone Blast, Blast from NCBI, UCSC Genome Browser, Gene Model Checker, Ensembl, MEGA 6, and Repeat Masker. Fluorescence in situ hybridization of chicken's chromosomes against Puerto Rican Parrot shows that chromosome Z from both species hybridize completely and do not present any translocation with other chromosomes. We started the annotation by identifying 937 scaffolds of the parrot genome matching to the chicken (Gallus gallus) chromosome Z. Chicken and budgerigar (Melopsittacus undulatus) sequence files were used as major templates for this work, but occasionally it was necessary to use other genomes such as that of the zebra finch (Taeniopygia guttata), turkey (Meleagris gallopavo), collared flycatcher (Fidecula albicolis), saker falcon (Falco cherrug) and peregrine falcon (Falco peregrinus). We analyzed the larger 66 scaffolds and found in them 212 genes, most of them with a molecular function for binding or catalytic activity . The total length of these scaffolds adds to 23.3 Mb, which represents approximately 28.3% to 38.9% of Z chromosome. Most of the analyzed scaffolds are in synteny with other bird species, but Scaffolds 583 and 605 show unique gene inversions for A. vittata, and Scaffold 563 shows an inversion only present in Psittaciformes.

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Life/Biological Sciences Presenter: Ramos Adams, Aisha A

Mentor: Perez-Velez, Mariel E.

Title: Economically Motivated Adulteration incidents in Spanish Speaking Regions

Authors: Aisha Ramos Adams (Universidad del Este), Yahaira Morales García (Universidad del Este), Karen Everstine, Phd (University of Minnesota)

Abstract

"Economically motivated adulteration (EMA) of food, also known as food fraud, is the intentional adulteration of food for financial advantage. EMA incidents reveal gaps in quality assurance testing methodologies that could be exploited for intentional harm. In contrast to foodborne disease outbreaks, EMA incidents present a particular challenge to the food industry and regulators because they are deliberate acts that are intended to evade detection. Large-scale EMA incidents have been described in the scientific literature, but smaller incidents have been documented only in media sources." (Karen Everstine, 2012) Part of our objectives in this research were: to understand what is EMA and what are the different adulteration types, update the incident database with cases from Spanish speaking regions. In general we managed to update the database with 38 cases from which 24 were from Spanish speaking regions. Sixteen of these were from South American Countries in which around 28% of the cases were detected in Colombia, 19% of the other cases were detected on Argentina and Brazil respectively. The primarily adulteration type detected on these cases were dilution and dilution with non-food grade substance. As a conclusion we discovered that EMA is a practice adopted by many at a global scale. Each day more countries develop systems to reduce this phenomena, but the sad part is that these systems are put in practice once a major public health hazard occurs. Meaning that the prevention of these cases is not a priority but instead a reaction when it is sometimes already too late.

Life/Biological Sciences Presenter: Ramos Orta, Jenifer

Mentor: Fernandez-del-Viso, Denny

Title: Varietal comparison of essential oils in Pimenta racemosa (Malagueta)

Authors: Jenifer Ramos Orta (University of Puerto Rico at Humacao) 282

Abstract

We are studying the possible differences in morphological and chemical characteristics of Malagueta trees (Pimenta racemose, Myrtaceae) that smell very differently. Our hypothesis is that the trees belong to at least two varieties reported for Puerto Rico, producing different essential oils. The trees are found in the University of Puerto Rico at Humacao. Morphological differences were observed using a dissecting microscope, which indicate that the trees belong to the varieties P. racemosa var. racemosa, and P. racemosa var. grisea. We extracted essential oils with steam distillation, from air dried leaves of separated trees, and are in the process of analyzing the extracted oils using gas chromatography, to look for chemical evidence, supporting the difference between varieties.

Life/Biological Sciences Presenter: Real Ramirez, Imperio

Mentor: Ortiz-Bermudez, Patricia

Title: Insights into the mechanism behind the synergistic effect of the combination of a synthetic beta-peptide with fluconazole on Candida albicans by use of a killing-curve approach

Authors: Imperio Real-ramírez (UPR-MAYAGUEZ), Jean Caraballo-león (UPR-MAYAGUEZ), Patricia Ortiz-bermúdez (UPR-MAYAGUEZ)

Abstract

Candida spp. are one of the most common causes of fungal infections in hospital settings. These infections primarily target the immunocompromised, which includes cancer and organ transplant patients as well as neonates. Moreover, these infections have high mortality rates due to the fact that traditional treatments against these infections, such as fluconazole, are becoming less effective because of rising fungal resistance. An alternative for treating these infections is the use of synthetic antimicrobial peptides, the beta-peptides. These materials can mimic the 3D conformation of natural antimicrobial peptides, which is necessary for their antimicrobial activity, while being resistant to proteases due to their synthetic nature. The beta-peptides also possess tunable properties based on the rational selection of the synthetic beta-amino acids subunits, which makes them a suitable platform for development of new antifungal treatments. Previous work has demonstrated that co-treatment of fluconazole and a beta-peptide exhibit a synergistic effect, but the mechanism of action of this synergy is still unknown. Our hypothesis is that the beta-peptide's initial disruption of the yeast cell's cytoplasmic membrane facilitates the uptake of fluconazole, inhibiting the biosynthesis of ergosterol, which further debilitates the membrane. To find evidence for this sequential mechanism, an approach utilizing killing curves was utilized to determine if the order of exposure to the agents caused a change in the magnitude of the synergistic effect. Assays were done to expose Candida albicans cells to both agents added at the same time, and to pre-expose the cells to one of the agents followed by addition of the 283

second agent. This comparison of the killing curves gives us insight into the mechanism of action of the co-treatment.

Life/Biological Sciences Presenter: Reyes De Leon, Adriana

Mentor: Rubin, Michael

Title: Isolation and Characterization of Cellulase-Producing Bacteria from Termite Gut and Ruminant Feces

Authors: Mariceli Fernandez-martinez (UPR-CAYEY), Natalia Maldonado-vazquez (UPR-CAYEY), Eliezer Cartagena-lopez (BENJAMIN HARRISON HIGH SCHOOL, CAYEY, PR), Hernando G. Steidel-rodriguez (UPR-CAYEY), Edwin Vazquez (UPR-CAYEY), Michael R. Rubin (UPR- CAYEY)

Abstract

Isolating and characterizing bacteria capable of converting the vast amount of biomass into usable biofuels is important to develop alternative energy sources and address global warming. Cellulose is an abundant polysaccharide and an important polymer comprising biomass. Cellulose-degrading bacteria produce cellulase enzymes that hydrolyze cellulose and convert it to glucose. Sources for cellulase- degrading bacteria can be found in the microbiomes in the gut of organisms that thrive on cellulosic biomasses as their major nutrient source. Cellulose-degrading bacteria were isolated and purified from termite gut and ruminant feces, by screening on media enriched with cellulose. After purification and cryogenic freezing, these bacteria were characterized using colony morphology and gram staining. Genomic DNA was purified and PCR was used to amplify 16S rRNA gene-specific products for sequence analysis and species identification. The isolated bacteria were screened using the Congo red clearing zone assay to detect cellulase activity. Several cellulose-degrading Gram-positive bacilli with central endospores were isolated from termite gut and ruminant feces and are being further characterized. Degenerate PCR primers are being designed and used to amplify genes encoding cellulases for sequence determination followed by analyses using bioinformatics tools. Cellulase enzymatic activities will be characterized using biochemical assays. Additional screenings are underway to isolate bacteria capable of using cellulose as well as other abundant biomass polymers as sole sources of carbon. Characterization of these isolates and their metabolic potential furthers our understanding of the composition and enzymatic activities of microbial communities. This project provides an opportunity for many undergraduate students to participate in original research experiences enriching their understanding of theoretical and experimental biology. The Howard Hughes Medical Institute (52007565) supported this work.

284

Life/Biological Sciences Presenter: Rivera, Maria I.

Mentor: Matchett, Ash

Title: What's Milk got to do with it? Characterizing the Milk Microbiota of the Endangered Caribbean Sea Cow.

Authors: Maria I. Rivera Diaz (Interamerican University of Puerto Rico, Bayamón Campus), Ashley Matchett, Phd (Interamerican University of Puerto Rico, Bayamón Campus), Antonio A. Mignucci-giannoni, Phd (Interamerican University of Puerto Rico, Bayamón Campus)

Abstract

Recent advances in the understanding of the human microbial flora or microbiome have highlighted the importance of the lactation and microorganisms in eukaryote health and longevity. In contrast the microbiome of the Antillean Manatee, an endangered marine mammal and indicator species, is poorly understood. Understanding the Manatee microbiome is key to understanding the developmental association of bacteria with mammals and monitoring changes in the local ecosystem. As a protected species, environmental monitoring of calf rearing, along with rescue centers efforts, is key to local conservation efforts. The benefits of breastfeeding are well established in mammals, these include microbial colonization, establishment of a healthy immune system along with other developmental roles that are still being investigated. Furthermore, conservation centers have been reporting frequent events of Manatee calf rejection in artificial environments.

The objective of this study was to characterize and compare the microbial milk flora of the Caribbean Manatee with other mammals and controls in the literature to determine possible associations, roles, and unique bacterial flora of the Puerto Rican Manatee.

Milk was expressed directly from a cleaned teat of lactating female Manatee. Sample milk DNA was extracted and sequenced using Next Generation Sequencing (NGS) for the 16S rRNA gene to determine the microbial diversity in the mammary gland. Bacterial population dynamics, variation, characterization were analyzed and determined with comparative bioinformatics studies from known microbiomes, principally from other lactating mammals and known species from the maritime ecosystem. Current developments, further progress, insights and future perspectives will be discussed.

285

Life/Biological Sciences Presenter: Rivera Carrión, Adalís

Mentor: Esteban, Ernesto

Title: Age References for Prostate Cancer in Puerto Rico

Authors: Adalís Rivera Carrión (UPR-Humacao), Ernesto Esteban Avila (UPR-Humacao)

Abstract

Prostate cancer in Puerto Rico ranks first among all cancers in incidence and mortality. In this research, we analyze data provided by the Puerto Rico Cancer Registry. In particular, age and PSA of 17000 Puerto Rican men with histological proven prostate cancer. We carry out a regression analysis of the data, and plot histograms age vs PSA to establish age references for PSA and prostate cancer. Further, by using a relationship between PSA and tumor, we predict the tumor progression by age.

Life/Biological Sciences Presenter: Rivera De Jesús, Mariela A.

Mentor: Maldonado-Ramirez, Sandra

Title: Areobiological Study of the UPRM Biology Building during the August 2015 Semester

Authors: Mariela A. Rivera De Jesús (University of Puerto Rico - Mayagüez), Keishla Hidalgo Vargas (University of Puerto Rico - Mayagüez), Marcel L. Fuentes Rivera (University of Puerto Rico - Mayagüez)

Abstract

Aerobiology is the study of airborne biological particles, such as pollen and spores. There is an element in indoor air quality that involves aerobiology and the regulation and monitoring of these airborne particles in order to ensure that the amount and types of biological particles in the air are within acceptable levels. This research is focused on the study of fungal spores and particles in the air of the University of Puerto Rico at Mayagüez (UPRM) Biology Building and the assurance of the building's air quality. During the semester of August 2015, two samplings using Andersen Cascade Impacter and Rodac Surface Plates were conducted to collect air and surface fungal samples, which were then incubated to grow fungal colonies. Colonies of interest, being mycelial colonies, were isolated and identified to genus level. It was found that the number of fungal spores was within acceptable levels. Also, while the volume of colonies from this semester was larger compared to the previous semester's samplings, the frequency of the found genera was similar. 286

Life/Biological Sciences Presenter: Rivera Mendoza, Jariangely

Mentor: Matchett, Ash

Title: Investigación Integradora de las Dinámicas de Descomposición en un Ambiente Tropical de Puerto Rico

Authors: Jariangely Rivera Mendoza (UIPR-BC), Dr. Ash Matchett (UIPR-BC)

Abstract

Intervalo Post-Mortem (PMI), o el tiempo transcurrido luego de la muerte, es importante para proporcionar información y una perspectiva científica a las investigaciones forense. Establecer PMI de los cadáveres humanos es de suma importancia, debido a su contribución al ambiente forense, por ejemplo, en la reconstrucción de la escena y el tiempo aproximado en que ocurrieron los hechos. Esto es particularmente importante en lugares de ambiente tropical donde los procesos de descomposiciones se aceleran debido al calor y la humedad. Sin embargo, las investigaciones forenses se enfocan en determinar el intervalo post-mortem mediante un solo método o dinámica de descomposición afectando la corroboración de los resultados. Es decir, que la estimación del PMI es propenso a inexactitud debido a que las distintas técnicas de monitoreo son independiente unas de otras aunque tienen el mismo enfoque en determinar el PMI.

El objetivo de este estudio en la investigación forense es determinar el PMI mediante la integración de una serie de técnicas desarrolladas recientemente en la estimación de PMI con un enfoque multidisciplinario correlativo. Esta investigación es un estudio en proceso en la descomposición en Puerto Rico, para establecer correlaciones y diferencias entre los múltiples ambientes que se encuentran en el clima tropical ciclónico del Atlántico durante los años 2014/2015. La recogida de muestras se realizó por duplicado, junto con los datos, en tres intervalos de tiempo diarios con la observación continua del ambiente y el clima.

Los datos de climatología fueron monitoreados por una estación vecina de meteorología. Se recopilo la medición de la dirección del viento, la presión, la lluvia, la humedad y la temperatura con el fin de observar la relación con la descomposición del organismo. En adicción, se monitoreo la variación internamente y externamente de la temperatura en el cadáver para ver los cambios en la contribución biológica en la descomposición.

Los cambios y las etapas de descomposición incluyendo la población entomológica fue recopilada por fotografías y toma de datos durante los procesos de descomposición. La estimación total de los artrópodos fue calculada con el fin de estimar aproximadamente la cantidad y tipo de insectos que pueden estar presentes durante la descomposición en Puerto Rico. Además, en las diferentes etapas los insectos fueron muestreados para realizar estudios futuros sobre la identificación morfológica y genética.

De esta investigación preliminar, obtuvimos un mayor entendimiento de las dinámicas de descomposición en un ambiente tropical y la correlación de diversas técnicas incluyendo la población 287

entomológica, la variación climática, la duración y determinación de las etapas de descomposición y como afectan al intervalo post-morten. Este estudio preliminar nos brindó información suficiente para determinar que el clima es un factor de suma importancia que debe ser considerado para la determinación del intervalo post-mortem. Los estudios futuros nos darán un entendimiento más claro de la interrelación entre el ambiente, la dinámica de descomposición con las variaciones físicas biológicas y químicas del cadáver post-mortem. La importancia de esta investigación es evidente y puede contribuir el aumento de la precisión en la determinación del PMI a través de la integración de múltiples técnicas independientes.

Life/Biological Sciences Presenter: Rivera Rivera, Stephanie

Mentor: González, Carlos

Title: Characterization of HuR protein partners on activated T-cells

Authors: Stephanie Rivera Rivera (UPR-RIO PIEDRAS), Antonio T. Raimundí Raimundí (UPR-RIO PIEDRAS), Maria F. Duque Osorno (UPR-RIO PIEDRAS), Carlos I. González Vargas (UPR- RIO PIEDRAS)

Abstract

Interleukin-3 (IL-3) is a pro-inflammatory cytokine secreted by T-cells that promotes stimulation and differentiation of myeloid cells. Previous results from our laboratory have demonstrated that IL-3 expression is regulated by the Adenine/Uridine-Rich Elements (AREs) present in the 3'-untranslated region (3'-UTR). AREs ability to modulate gene expression is dependent on ARE-Binding Proteins (ARE- BPs) that specifically recognize these regulatory sequences. IL-3 AREs are recognized by the ARE-BP, Human antigen R (HuR). HuR is a nuclear protein that shuttles to the cytoplasm to stabilize the mRNA and controls translation after being phosphorylated by the p38MAPK pathway. To assess the role of p38 in HuR regulation and how it affects the interaction of HuR with other ARE-BPs, we activated Jurkat T- cells at 0, 0.5, 6 and 12 hours after pre-treatment with and without SB202190, a p38 inhibitor. Nuclear/cytoplasmic protein extracts were obtained for immunoprecipitation of HuR to identify potential protein partners. Fractions from the immunoprecipitation assay were separated by SDS-PAGE and subjected to Silver Staining for band visualization. Results from the immunoprecipitation experiment demonstrate 5 distinct bands of different molecular mass in the elution fraction from a cytoplasmic extract at 6 hours of activation in the presence of SB202190. Ongoing experiments are intended to confirm these initial immunoprecipitation results by Western blot analysis and optimize the conditions required for higher protein concentration yields and further identification of HuR interacting proteins. Ultimately, elucidating the role of these novel factors in IL-3 expression can provide new insights about ARE-mediated post-transcriptional control, inflammation and cancer.

288

Life/Biological Sciences Presenter: Rivera Rodríguez, Jaileen M.

Mentor: Esteban, Ernesto

Title: Nomograms as Prediction Tools for Prostatic Diseases

Authors: Jaileen Rivera Rodriguez (University of Puerto Rico -Humacao)

Abstract

Using an analytical solution of a non-linear differential equation we have developed nomograms as prediction tools designed to understand the relationship between PSA, age, and tumor size.

Two nomograms summarize our results for Japanese patients with localized prostate cancer (T2a, T2b) and enlarged prostate volume (BPH). It is showed that a given PSA value can be reached by patients with different age, tumor size, and prostate volume. These nomograms also are useful to distinguish between T2a and T2b localized prostate cancer. Further, PSA level values are higher in a T2b stage as compared to T2a stage.

This research may be useful to improve the diagnostic and prognosis of prostatic diseases.

Life/Biological Sciences Presenter: Rivera-Cruz, Cosette M.

Mentor: Rubin, Michael

Title: Characterization of Cellulose-Degrading Bacteria Isolated from Tropical Soils of Puerto Rico

Authors: Cosette M. Rivera Cruz (University of Puerto Rico at Cayey), Mariceli Fernandez- martinez (University of Puerto Rico at Cayey), Michael R. Rubin (University of Puerto Rico at Cayey) 289

Abstract

Some studies suggest that crude oil reserves will be nearing depletion in the next 50 years. Due to the abundance of cellulose and its capacity to hydrolyze into glucose, biofuel production from plant tissue is considered a viable alternative for energy production. However, there are some existing limitations to the current biofuel production protocols, one of them being the lack of biocatalysts or enzymes for the conversion of plant biomass into bioethanol that can work efficiently and cost effectively at extreme temperature or pH conditions. These enzymes, called cellulases, are found in nature often synthesized by microorganisms including fungi and bacteria. Some of these microorganisms establish symbiotic relationships with organisms that consume plant tissue as part of their diet such as graminivores and xylophages. With this project we attempt to characterize microorganisms found in termite digestive tracts, as well as in their immediate environment, for their ability to produce cellulases; by using both culture dependent and independent protocols, with the aim of identifying bacterial species that could potentially be used for the optimization of existing biofuel production protocols. Through preliminary experiments, we found three bacterial isolates capable of producing cellulase, by performing Congo Red staining on carboxymethyl cellulose agar plates. In addition, metagenomic DNA has been isolated in order to assess the bacterial biodiversity within a sample by sequencing PCR amplified products using primers specific for 16S rRNAs and various cellulase genes. Isolation and characterization of genes encoding cellulases as well as biochemical assays of their cellulase activities can help to optimize the production of bioethanol improving their use as an alternative energy source.

Life/Biological Sciences Presenter: Rodriguez Deliz, Carla L.

Mentor: Suarez-Martinez, Edu

Title: Pain Related Behaviors in Mice Expressing Sickle Cell Hemoglobin: Modulation by Bivalent Ligands

Authors: Carla L. Rodriguez-deliz (University of Puerto Rico at Ponce), Guillermo Puig (School of Dental Medicine University of Puerto Rico at Rio Piedras), Giuseppe Cataldo (University of Minnesota Twin Cities), Donald A. Simone (University of Minnesota Twin Cities)

Abstract

Sickle cell disease (SCD) is a genetic disorder that produces abnormal hemoglobin, leading to vaso- occlusion. The hallmark of this condition is pain. Little is known about the mechanisms of SCD, therefore, treatment remains inefficient. Several types of transgenic mice have been developed which mimic human pathology in order to study therapeutic options for SCD, including the Townes mice. In this study, we aimed to characterize pain-related behaviors in the Townes sickle mouse, as well as identify the onset of SCD-associated hyperalgesia. In addition, we sought to study the effect of a new drug, MCC22, on such pain-related behaviors. For this, we measured paw withdrawal frequency (PWF) 290

and mechanical threshold, as well as grip force to compare between control (AA), sickle trait (AS) and sickle cell (SS) mice. MCC22 was administrated through intraperitoneal (IP) injection and mechanical tests were conducted at 15, 30 and 60 minutes to evaluate its effects. We observed that sickle mice had significantly higher PWF, lower mechanical thresholds and grip force when compared to AA and AS mice. Administration of MCC22 reduced PWF in SS mice. Decreases in relevant pain behaviors suggest that MCC22 may prove to be a novel effective therapeutic in SCD.

Life/Biological Sciences Presenter: Rodríguez Flores, Eneric J.

Mentor: Garcia Arraras, Jose E.

Title: Effects of Wnt Pathway Activation and Inhibition in the Intestinal Regenerative Process in the Echinoderm Holothuria glaberrima

Authors: Eneric J. Rodríguez Flores (UPRRP), Natalia Rodríguez Sosa (UPRRP)

Abstract

Holothurians are known for their extraordinary regenerative capacities. Several studies have focused on the molecular mechanisms involved in this process. The canonical Wnt pathway has been previously linked to development and regeneration in many animal species. In-situ hybridization experiments in our laboratory showed an up-regulation of Wnt transcript during intestinal regeneration; however, the possible function of this pathway during the regenerative process remains unclear. In an attempt to elucidate this question, we studied the role of the Wnt signaling pathway in the intestinal regeneration of the Holothuria glaberrima by means of Wnt pathway activation and inhibition. In this study H. glaberrima individuals were treated in vivo with a Wnt pathway inhibitor epigallocatechin-3-gallate (EGCG) and activator lithium chloride (LiCl). Animals were treated for 8 days post-evisceration (dpe) and sacrificed at 10-dpe. We then carried immunohistochemical analyses of the characteristic processes of sea cucumber intestinal regeneration that have been well documented in our laboratory. These included muscle dedifferentiation, collagen degradation and rudiment growth. For EGCG treated animals a significant decrease in collagen degradation, a slowed process of SLS formation and a decrease in rudiment size was observed. In contrast, LiCl treatment increased the size of the rudiment. Our results suggest that the Wnt pathway plays a role in modulating certain regeneration mechanisms that lead to the formation and growing of the rudiment into a new intestine. Research was funded by NSF (IOS- 0842870), NIH (R15NS01686) and the University of Puerto Rico. JMR was funded by NIH-MBRS (RISE) program of the University of Puerto Rico.

291

Life/Biological Sciences Presenter: Rodri•guez Lopez, Julymar

Mentor: Tremblay, Raymond

Title: Shadows and growth potential in Campylocentrum fasciola

Authors: Julymar Rodríguez López (University of Puerto Rico at Humacao)

Abstract

Light is one of the most important factors in the growth and reproduction of plants. Even though epiphytes may seem to be continuously exposed to light, variation in light environment can influence growth and reproduction. In this case we evaluate the variation in light enviornment in the epiphytic leafless orchid Campylocentrum fasciola in two abandoned Guava farm in Puerto Rico. We tested the hypothesis that light environment influences plant size and reproductive potential using the following indices: Leaf Area Index, Visible Sky, Indirect Site Factor and uniformity of canopy across the image measured with a Hemisferical Photography (Fisheye/Canopy Photography) above individual plants. We collected morphological information from 45 individuals and correlated the previous indices with the size of the plant, lenght of the longest root, number of roots, number of inflorescences, flowers and fruits.

Life/Biological Sciences Presenter: Rodríguez Mártir, Keishla M.

Mentor: Malavez, Yadira

Title: Evaluation of the antibacterial activity of the Tamarindus indica

Authors: Keishla M. Rodríguez Mártir (University of Puerto Rico at Aguadilla), Mario Vendrell Martínez (University of Puerto Rico at Aguadilla), Stephanie Ríos Cordero (University of Puerto Rico at Aguadilla), Angel D. Ramos Mercado (University of Puerto Rico at Aguadilla), Yadira Malavez (University of Puerto Rico at Aguadilla)

Abstract

Annually infectious diseases cause the death of 23,000 people in United States. The overuse and misuse of antibiotics, hand sanitizers and antibacterial agents has been associated with bacterial resistance. The identification of novel antimicrobial substances is important to protect us against pathogenic bacteria. For many years, Tamarindus indica (tamarind) has been used as a medicinal plant. It contains flavonoids and other polyphenols that have been recorded as antimicrobial agents. The aim of the study was to 292

identify parts of the Tamarindus indica plant with antimicrobial activity effective against gram-negative bacteria. Fresh and dry extracts were prepared in water or ethanol 95%,for a total of 12 different extracts. The antibacterial properties of the extracts were analyzed using five different bacteria strains. Proteus mirabilis presented the highest susceptibility. Were used to determine the minimum concentration that contains antimicrobial activity. Ethanol extracts showed antimicrobial activity in all gram-negative bacteria tested. In summary, ethanol tamarind seed extracts demonstrated to have antibacterial properties against gram-negative pathogenic bacteria. The use of medicinal plant extracts such as tamarind is an alternative to synthetic antibacterial agents in the fight against pathogens.

Life/Biological Sciences Presenter: Rodríguez Núñez, Kiara M.

Mentor: Rios Velazquez, Carlos

Title: Identification of Mercuric Reductase Genes in Purple Non- Sulfur Bacteria (PNSB) isolates from Microbial Mats in Puerto Rico

Authors: Kiara M. Rodríguez Núñez (UPR- Mayaguez), Jesie M. Rullán Cardec (UPR- Mayaguez), Prof. Carlos Ríos Velázquez (UPR- Mayaguez)

Abstract

A mayor concern has arisen after the Environmental Protection Agency revealed in 2014 that 79.7% of rivers and streams used as drinking supply in Puerto Rico were impaired with toxic metals such as mercury. This heavy metal is bio-accumulative and its consumption leads to kidney and liver damage. Several cases of human intoxication have been reported after mercury intake. For example, the Agency for Toxic Substances and Disease Registry recorded the poisoning of 290 civilians in Puerto Rico after eating fish grown in mercury contaminated waters. Electrochemical processes, evaporation, filtration and other techniques have been employed to extract these metals from aquatic environments. Unfortunately, by-products such as toxic waste, low effectivity and high costs limit its use. However, bioprospectors such as purple non sulfur bacteria (PNSB) has been studied for its possible use in mercury removal from water reservoirs. The benthic hypersaline microbial mats PNSB collection of the Laboratory of Microbial Biotechnology and Bioprospecting was studied for the presence of genes related to bacterial mercury resistance. During this study, 7% of the isolates presented a positive amplification for mercuric reductase genes (1,238 bp). Other amplifications will be proved by in silico analysis in order to validate their genetic identity. The same analysis of the 16S rDNA was used to suggest that PNSB isolates belong to Rhodopseudomonas, Rhodospirillaceae and Rhodobacter family. The results suggest an unknown biotechnological potential of these isolates from extreme and unexplored environments by the presence of mercury reductase genes and further bioremediation applications in metal resistance.

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Life/Biological Sciences Presenter: Rodriguez Ramos, Josue

Mentor: Rios Velazquez, Carlos

Title: Transduction Facilitating Genes of Rhodobacter sphaeroides

Authors: Josue A. Rodriguez Ramos (Undergraduate Researcher), Moises De Jesus Cruz (Graduate Researcher), Carlos Rios Velazquez (Professor/Mentor)

Abstract

Bacteriophages can be utilized as an efficient way to introduce genetic material into host cells. This process, known as transduction, is used as a bio-prospecting tool in order to perform genetic and biochemical analysis. Transduction is also very useful in Biotechnology, where it is commonly used in order to mass produce desired molecules. Our laboratory has isolated and characterized several Rhodobacter sphaeroides specific bacteriophages able of performing lysis, but to date, no transduction capability has been detected. The goal of this research is to identify genetic targets in R. sphaeroides that are involved in the susceptibility of infection by the phages and the integration of the phage into the R. sphaeroides genome. A series R. sphaeroides 2.4.1 and 630 Tn mutants were generated and its susceptibility for infection by seven different bacteriophages were determined by an overlay plaque assay. A total of 23 R. sphaeroides 2.4.1 and 5 R. sphaeroides 630 Tn mutants have been generated. There is a notable difference between the mutation success rate of the mutants of R. sphaeroides 2.4.1 and those of R. sphaeroides 630. R. sphaeroides 2.4.1 has a higher success rate of mutation. Viral plaque assays will be performed on the isolated mutants in order to screen for a change in infection rate by the previously isolated phages. Once we obtain a positive result in the viral plaque assay, we will sequence the mutant and identify the genes that are responsible for the integration and susceptibility of infection.

Life/Biological Sciences Presenter: Rodriguez Sastre, Nahomie

Mentor: Soto-Nieves, Noemi

Title: Induced apoptosis in COLO-205 cells by aza-podophyllotoxin derivatives

Authors: Nahomie Rodriguez-sastre (Universidad Metropolitana), Noemí Soto-nieves (Universidad Metropolitana), Ajay Kumar (Universidad Metropolitana) 294

Abstract

Colon cancer is the third most common cancer in Puerto Rico. This cancer is currently treated with invasive treatments, therefore new therapeutic treatment are needed. Our group is evaluating several azapodophyllotoxin (AZP) derivatives, such as 8a (AP201), 9a (AP301), 8c (AP203) and 9c (AP303), to treat colon cancer. AZP is a heterocyclic compound with 5 fused rings (A, B, C, D, E) synthesized in the laboratory analogous to a biologically active natural lignin, podophyllotoxin (PD). Previously, our group published that derivatives 8a and 9a induce cell death by different signaling pathways, although the difference in these two compounds was on ring A. These project will study the apoptosis induction in COLO205 cells using derivatives 8c and 9c. This will allow the establishments of the structural activity relationship (SAR) of the best AZP derivatives against colon cancer cell lines. In these experiments COLO 205 cells were treated with 8c or 9c AZP derivatives, DMSO (negative control) and etoposide (positive control) for 24 hrs. The cell viability was measured and an Annexin V was performed. The cell viability was as expected with DMSO, etoposide and 9c, however 8c viability was very similar to our negative control, which is incongruent with our previous observations. We are in the process of repeating these experiments to confirm our results. Also, we started the analysis of microarray data obtained from experiments of treatments of COLO 205 cells with derivatives 8a and 9a.

Life/Biological Sciences Presenters: Rodriguez Valentin, Camila Beatriz Rosa Marín, Angelique

Mentor: Sloan, Steven

Title: Odonata

Authors: Camila B. Rodriguez Valentin (University of Puerto Rico at Bayamon), Xavier Marrero Nieves (University of Puerto Rico at Bayamonm), Angelique Rosa Marin (University of Puerto Rico at Bayamon), Isamar Sanchez Calafell (University of Puerto Rico at Bayamon)

Abstract

El proyecto Odonata tiene como objetivo realizar un censo sobre la población actual de las libélulas en Puerto Rico. Desde el 1938, no se tiene conocimiento sobre la biodiversidad de este orden en la Isla, incluso esta investigación servirá para comparar la diversidad de este orden con otras islas cercanas donde habite la especie. Estos macroinvertebrados acuáticos son los principales bioindicadores de la biodiversidad y el estado de los ecosistemas acuáticos. Además, estos depredadores son de gran ayuda en la regulación de otros insectos que puedan causar algún daño ecológico o antropológico. Por otro lado, se pretende verificar el impacto masivo que ha tenido el desparramamiento urbano y como este ha afectado las especies existentes de libélulas en Puerto Rico. 295

Bajo la dirección y auspicio del programa PR-LSAMP, se dividió a Puerto Rico en ocho zonas con coordenadas específicas. Se le asignó cada zona a cada una de las universidades participantes. La primera fase de este proyecto consiste en la caza de las especies. A los participantes de la Universidad de Puerto Rico, Recinto Bayamón el área localizada entre las coordenadas 18.500, -66.500 18.208, - 66.117. Hasta el momento, se han capturado 140 libélulas en los pueblos de Corozal, Guaynabo, Bayamón y Dorado. La segunda fase consistirá en la clasificación de la taxonomía de las libélulas capturadas. Por último, se procederá a la conservación de los organismos para realizar el censo total de las especies encontradas en Puerto Rico.

Life/Biological Sciences Presenters: Romero Pagan, Patricia M. Roman Acevedo, Arnaldo J.

Mentor: Romero, Lizbeth

Title: Development and Optimization of Molecular Protocols for Harvestmen Species Identification

Authors: Patricia M. Romero Pagan (Interamerican University-Arecibo), Arnaldo J. Roman Acevedo (Interamerican University-Arecibo), Ignailiz Moldovan Arroyo (Interamerican University-Arecibo), Jorge Domena Barrios (Interamerican University-Arecibo), Lizbeth Romero Perez (Interamerican University-Arecibo)

Abstract

From the phylum Arthropods and under the Arachnid class we can find the order of Opiliones, which are organisms similar to spiders. This is a cosmopolitan group commonly known as Harvestmen that includes approximately 5000-7000 species worldwide. Opiliones are often found in disturbed habitats as well as in forest, under stones, in caves, on the trunks of trees, on the soil, in forest litter, in soil crevices, and sometimes rather deep in the soil. They are divided into four suborders: Cyphophtalmi, Dyspnoi, Eupnoi and Laniatores. Not much is known about Harvestmen and their classification has been object of multiple disputes. In Puerto Rico only 10 species have been identified. The objective of our research is to optimize a DNA extraction method that will allow the isolation of DNA from one Harvestmen leg in order to be able to perform a genetic analysis for the identification of species. Harvestmen samples were collected and saved on 95% alcohol. DNA was extracted using lysis buffer, salt buffer and precipitation with isopropanol. Our results show that a simple method of extraction with a 24 hour lysis step was successful in allowing the isolation of pure DNA and in high concentration. The purified DNA was used for PCR analysis using primers for the 16S rDNA, 28S rDNA and NADH genes. More studies are required for the optimization of the PCR reaction using other primer sequences.

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Life/Biological Sciences Presenter: Rosa Mercado, Nicolle A.

Mentor: Rubin, Michael

Title: Evolutionary Relationship Between GAPDH Genes in Plants Found in Puerto Rico

Authors: Nicolle A. Rosa Mercado (UPR Cayey), Charlene N. Rivera (UPR Cayey), Patricia N. Claudio (UPR Cayey)

Abstract

Glyceraldehyde-3-phosphate dehydrogenases (GAPDH) belong to a family of housekeeping genes that catalyze a reaction in glycolysis, a metabolic pathway that turns glucose into pyruvate during cellular respiration. There are eight different GAPDH genes throughout the Arabidopsis thaliana genome. Characterizing the GAPDH genes from different plants is important for studying the evolutionary relationship between this gene family. We hypothesize that specific protein domains encoded by these GAPDH genes are conserved due to important functional restraints. We have selected plants with valuable properties found in Puerto Rico. The specific aims of this project include extracting genomic DNA in order to PCR amplify GAPDH genes using specific primers, cloning PCR products into vectors, sequencing these products, and analyzing the data using bioinformatics tools. BLAST analyses revealed the cloned genes to be: GAPC (cytosolic NAD+-dependent enzyme) for the genes cloned from Cyperus alternifolius, Schefflera actinophylla, and Oxalis corniculata and GAPDH (chloroplastic NADP+-dependent enzyme) for the gene cloned from Plectranthus amboinicus. These GAPDH sequences were submitted to GenBank. BLAST similarity analysis confirmed that the cloned genes from Petiveria alliceae and Polygala cowellii also belong to the GAPDH gene family. Future work includes cloning and characterizing GAPDH and DNA barcoding genes (such as accD, ITS2, and ITS) from additional economically important plants. We will then address the hypothesis regarding whether or not amino acids important for protein structure and function are conserved increasing our understanding of plant genes and their encoded protein products.

297

Life/Biological Sciences Presenter: Rosado, Irvin

Mentor: Rosado, Irvin

Title: Assesment of the Functionality and Stability of Detergent Purified Nicotinic Acetylcholine Receptor from Torpedo californica

Authors: Irvin D. Rosado (Department of Biology, University of Puerto Rico, Río Piedras Campus), Jesús A. Acevedo (Department of Biology, University of Puerto Rico, Río Piedras Campus), Joel E. González-nieves (Department of Biology, University of Puerto Rico, Río Piedras Campus), José A. Lasalde-dominicci (Department of Biology, University of Puerto Rico, Río Piedras Campus), Orestes Quesada-gonzález (Department of Physical Sciences, University of Puerto Rico, Río Piedras Campus), José O. Colon-sáez (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus;)

Abstract

Lipidic Cubic Phase (LCP) is a crystallization platform for membrane proteins that has increased exponentially the number of crystal structures in the past decade. However, little is known about the effect of the isolation methodologies to LCP. We examined the affinity-purified nicotinic acetylcholine receptors (nAChRs) from Torpedo californica (Tc) functionality prior to LCP preparation, using planar lipid bilayer (PLB) and two electrode voltage clamp (TEVC); and the stability in the LCP for a period of 30 days using fluorescence recovery after photobleaching (FRAP). These are essential parameters for nAChR crystallization. Our studies show that nAChRs extraction is feasible by employing phospholipid analog detergents, for instance Foscholine (FC) and Lysofoscholine (LFC) head groups with 12, 14 and 16 carbon chains (FC-12, FC-14, FC-16, LFC-12, LFC-14, LFC-16) and the Cyclofos family with 4, 6 and 7 carbon chains. The mean amplitude of acetylcholine evoked currents using TEVC for FC and LFC family behave different in term of the acyl chain length, being FC-12 (-177 ± 23 nA) and LFC-14 (-488 ± 64 nA) the leaders in their respective family. The functional activity recorded using TEVC was consistent with the PLB assays. The stability of nAChR-detergent complex (nAChR-DCs) in FC and LFC families display a correlation with the length of the acyl chain and the Mobile fraction (MF); longer acyl chains nAChR preserve higher MF (approximately 90%), compared to 40-60 for shorter acyl chains for the period assayed. For the Cyclofos family, the (MF) values alternate from 0.30 to 0.70, and variability between days was also observed. Moreover, cholesterol addition to the Cyclofos extracted nAChR reduced MF variability, suggesting that cholesterol could stabilize the nAChR in LCP. These results demonstrate that some of these detergents could be used for crystallization studies.

298

Life/Biological Sciences Presenter: Rosario Meléndez, Natalia

Mentor: Flores-Cruz, Zomary

Title: Vibrio fischeri as a biosensor of emerging contaminants

Authors: Natalia Rosario-meléndez (Univeristy of Puerto Rico-Rio Piedras, Dept of Biology), Meraris Del Mar Tolentino (Univeristy of Puerto Rico-Rio Piedras, Dept of Biology), Derek M. Garcia, Josell Perez (University of Puerto Rico-Rio Piedras, Dept of Chemistry), Zoar Y. Mercado (University of Puerto Rico-Rio Piedras, Dept of Chemistry), Liz Díaz (University of Puerto Rico-Rio Piedras, Dept of Chemistry), Zomary Flores-cruz (Univeristy of Puerto Rico-Rio Piedras, Dept of Biology)

Abstract

Fertilizers, pesticides, pharmaceuticals, and personal care products are used in everyday life by millions of people. However, the disposal of these substances is not regulated; therefore they are not being removed in treatment facilities, which cause them to end up in the ocean. The effect these chemicals might have on living organisms, or their combination is not known and there are no efficient ways to detect them. As an alternative to these problems we used the marine bioluminescent bacterium Vibrio fischeri as a biosensor. V. fischeri is a well studied bacteria known for its ability emit bioluminescence. For this purpose we grew the bacteria in the presence of various emerging contaminants. The growth of V. fischeri was not affected by the tested contaminants, with the exception of known antibiotics. In contrast, bioluminescence changed significantly in presence of caffeine (dietary supplement) and amlodipine besylate (prescription medication). These results suggest that V. fischeri could be used for the detection of emerging contaminants. Future work includes testing other emerging contaminants, and a metabolomic analysis to observe how V. fischeri is metabolizing the contaminants.

Life/Biological Sciences Presenter: Rubio Marrero, Angel

Mentor: Rios Velazquez, Carlos

Title: Production of Antibacterial Substances by Purple non Sulfur Bacteria against Bacillus subtillis

Authors: Angel M. Rubio-marrero (University of Puerto Rico Mayaguez Campus), Jesie Rullan- cardec (University of Puerto Rico Mayaguez Campus), Carlos Ríos-velázquez (University of Puerto Rico Mayaguez Campus) 299

Abstract

During the last decade the antimicrobial resistance by several microorganisms has gone from being a myth to reality that affects all of us progressively. According to the Center for Disease Control and Prevention (CDC) each year in the United States at least 2 millions of people have been infected with bacteria with antibiotic resistance from which 23 thousands die due to these infections. Purple non sulfur Bacteria (PNSB) are ubiquitous group of microbes and with versatility in their metabolism that allows them to grow under different environmental conditions. Our laboratory has a collection of PNSB isolated in different environments in Puerto Rico such as water reservoirs, phytothelmata and microbial mats. One of the advantages provided by the versatility of such group is their potential production of inhibitory agents against microbes capable of antimicrobial resistance. In this way PNSB can be used as bioprospects in the pharmaceutical industry to produce antimicrobial substances and avoid millions of dollars in losses thanks to their versatility in their metabolism that allows them to grow in different conditions in which the opportunist microorganisms cannot grow. In this investigation we are interested in studying the capability of 52 isolated from Puerto Rico to produce antimicrobial substances against Bacillus subtillis. The PNSB bioprospects were cultured aerobically and anaerobically in LB Miller Agar and Sistrom Agar under phototrophic conditions at 32°C for 72 hours to determine the optimal conditions to produce the antibiotics. After patching the culture media with the PNSB, top agar with B. subtillis was poured on top of the bioprospects and incubated at the different conditions and analyzed after 24, 48 and 72 hours to determine the sensibility by the target by the presence of an inhibition zone. A total of 6 PNSB were capable of inhibiting the target in LB Miller Agar aerobically. In Sistrom Agar, 15 and 5 PNSB showed inhibition under aerobic and anaerobic conditions respectively. These results suggest that the PNSB isolated in Puerto Rico are bioprospects with potential used as a source for antimicrobial agents production.

Life/Biological Sciences Presenter: Ruiz Ortiz, Jenelys

Mentor: Massey, Steven

Title: Testing the influence of population size on underlying mutation rates across eukaryotes using whole genome coalescence analysis

Authors: Steven E. Massey (University of Puerto Rico-Rio Piedras Campus), Jenelys Ruiz Ortiz (University of Puerto Rico-Rio Piedras Campus and Bayamon Campus)

Abstract

The purpose of this project is to examine Drake's rule, which establishes that the average mutation rate within a particular phylum is approximately constant and inversely proportional to genome size. Over the years our lab has developed the idea that the size of proteome-the entire amount of information that can be expressed within a genome- exerts a selective pressure on mutation rates, given that the 300

larger the proteome the larger the mutational target (and so a greater selective pressure to evolve better DNA repair and proofreading). A countervailing argument has been that population size influences mutation rates, with smaller population sizes leading to a decreased selection pressure on mutation minimization. We will test this by calculating the effective population sizes from a wide range of eukaryotes for which we possess both the mutation rate and a complete genome sequence; this will be calculated using genome wide coalescent analysis using the PSMC software. Then, we will determine if there is a correlation between mutation rate and population size.

Life/Biological Sciences Presenter: Sanchez Peña, Andrea

Mentor: Flores-Cruz, Zomary

Title: ahpC expression in Vibrio fischeri

Authors: Andrea Sánchez Peña (University of Puerto Rico - Río Piedras), Wesley X. Torres Pérez (University of Puerto Rico - Río Piedras), Zomary Flores-cruz (University of Puerto Rico - Río Piedras)

Abstract

Vibrio fischeri is a bioluminescent marine bacterium that forms a beneficial symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. During the interaction, V. fischeri experiences oxidative stress when exposed to host derived reactive oxygen species (ROS). This bacterium contains a high abundance of Alkyl hydroperoxide reductase (AhpC), which is predicted to degrade peroxides, suggesting that it may be important during host interaction. In this study we investigated ahpC expression in different V. fischeri mutant backgrounds, different growth phases and oxidative stress conditions caused by methyl viologen. The mutant backgrounds used were ahpC mutant, catalase mutant and an ahpC/catalase double mutant. ahpC expression increased as the growth phases progressed, was significantly higher in the mutant backgrounds than in the wild-type parental strain, and was further induced when grown in the presence of methyl viologen. Among the mutant backgrounds, on average, ahpC expression was highest in the ahpC mutant strain. Together, these results suggest that the mutant strains are experiencing oxidative stress and that this stress induces the expression of ahpC. Future work will include expression studies of catalase gene.

301

Life/Biological Sciences Presenter: Sanchez Ruiz, Josian

Mentor: Ramirez, Alonso

Title: Natural history observation of Telebasis vulnerata in Puerto Rico

Authors: Josian Sánchez Ruiz (Universidad de Puerto Rico- Rio Piedras), Alonso Ramirez (Universidad de Puerto Rico- Rio Piedras)

Abstract

Natural history studies provide useful information on species dynamics, population structure and the role of a species in its environment. Odonata are good models for these studies, but there is limited information for tropical species. Here we present the natural history of Telebasis vulnerata (Coenagrionidae), a dominant species of damselfly in Puerto Rico. We assessed its population structure and describe its behavior (e.g, territoriality, sex ratio, reproduction and microhabitat use). The study took place during summer 2015 at El Yunque National Forest, Puerto Rico. A mark-recapture method was used to study territoriality and population characteristics, along with individual behavioral observations. Males exhibited the expected territorial behavior; defending ovipositional areas, staying within a small area (

Life/Biological Sciences Presenter: Sanfiorenzo, Charles

Mentor: Massey, Steven

Title: Testing the link between mutation load and body size in mammals using whole genome SNP impact analysis

Authors: Steven E. Massey (University of Puerto Rico - Rio Piedras Campus), Charles Sanfiorenzo Cruz (University of Puerto Rico - Rio Piedras Campus and Bayamon Campus)

Abstract

Although numerous studies have exposed the effects of genetic drift, demographic stochasticity, and inbreeding depression within small population groups, mutational load has yet to be fully explored for many organisms. Recent published works have slowly provided proof of the overall significance of having an estimate of mutational load within select individuals, populations, and species. More so, identifying key factors that influence the mutational load of assorted populations (or individuals) within a given species, and their true impact on biological fitness is vital for our current understanding of 302

biological dynamics. This in turn has led us to make several inquiries and propose the following correlations for animal populations: (i) body size is inversely correlated with population size, and (ii) a small population size leads to increased drift and so a greater accumulation of mutations. Thus, animals with larger body sizes should have smaller population sizes and so experience a higher mutation load. For the purpose of testing our working hypothesis, we will determine the mutation load of mammals of different body sizes by analyzing their complete genome sequences. This will be accomplished using SNPEff software, which assigns impact values to individual mutations; these will be summed across all mutations present in each genome to calculate the total mutation load. This study is of considerable importance for conservation genomics, as it means that endangered species of reduced population size may experience an elevated mutation load.

Life/Biological Sciences Presenter: Santana Rivera, Yasmarie

Mentor: Alves, Janaina

Title: The effects of LIF cytokine on modulating the outcome of apoptosis in HIV-Nef infection

Authors: Yasmarie Santana Rivera (Universidad de Puerto Rico Recinto de Río Piedras), Mariolga Masa Pereira (Universidad de Puerto Rico Recinto de Río Piedras)

Abstract

The effects of Human Immunodeficiency Virus (HIV) on the central nervous system (CNS) are particularly important, leading to causing neurological deterioration in form of altered cognitive abilities, motor dysfunction and eventually dementia. In spite of pharmacological control of the infection, HIV- associated neurocognitive disorders (HAND) remain intractable. Prior studies have shown that HIV infection of the astrocytes leads to the production of HIV-Nef without viral replication. In addition, Nef expression in the astrocytes of post-mortem patients with HIV associated dementia suggests the role of Nef as a key mediator. An alternative approach is needed which will prevent or alleviate the CNS damage following HIV infection. We propose to evaluate the effectiveness of leukemia inhibitor factor (LIF) to modulate the inflammatory effects in HIV infection in Neural Progenitor Cells (NPC), and anti- inflammatory and neural protective effects in Nef expression astrocytes. LIF is a cytokine known to be released from hematopoietic and NPCs, among others with anti-inflammatory and neuroprotective effects. We expect that the secretion of LIF induces neuroprotection of HIV-Nef mediated neural damage due to its anti-inflammatory and neuroprotective factors, and that it will have immune effects restoring the learning that is disrupted by Nef. There will be four experimental phases: NPC extraction and culture, the measurement of LIF in culture supernatant, functional evaluation of LIF induced neuroprotection, and histological evaluation of LIF. Proving the value of LIF as an anti-apoptotic agent resulting in HIV neuroprotective effect a system of infusing LIF via alternative systematic administration will began to be worked on. 303

Life/Biological Sciences Presenter: Santiago-Rivera, Nydia N.

Mentor: Restrepo, Carla

Title: Using the leaf "iome" to distinguish functional groups of vines in Puerto Rico

Authors: Nydia N. Santiago (UPR-RP), Diana Delgado (UPR-RP), Yakshi Ortiz (UPR-RP), Carla Restrepo (UPR-RP)

Abstract

Plant traits are increasingly used to examine the roles that plants play within ecosystems, as well as to understand their defense mechanisms and adaptation abilities. For example, at community-scales specific leaf area (SLA) provides information about strategies to capture light, carbon and nitrogen leaf content provides information regarding energy acquisition through photosynthesis, and leaf carbon and nitrogen stable isotopes can be used to determine plant specialization to climate and mechanisms for the acquisition of nitrogen. Much less is known about mineral nutrient and trace element composition - ionome - of leaves. Our objectives were three-fold. First, develop a protocol to establish the elemental composition of leaves based on X-ray fluorescence spectroscopy (XRF). Second, characterize the elemental composition of leaves of proliferating vine species. Third, establish functional groups of vines based on leaf traits related to plant's ability to capture light (specific leaf area), conduct photosynthesis [%Carbon (C), %Nitrogen (N), C:N ratios, delta 13C, delta 15N], and grow (major, minor, and trace element concentrations). Leaves of 27 vine species belonging to 13 families were collected across a broad area in central Puerto Rico. Fresh leaves (20-25 per species) were passed through a leaf area meter and then oven-dried (60°C for at least 48 hours) to record their fresh area and dry-weight, respectively. A second sample of leaves was oven-dried and subsequently the leaves were cut, granulated, and pulverized for analysis. One set of samples was sent out for C, N, and stable isotope analyses (Stable Isotope Facility, UC Davis) whereas a second set will be used to develop a protocol and measure the elemental composition using XRF. Preliminary data indicates that the specific leaf area in our sampled vine species is 219.10 ± 68.54 cm2g-1. The C and N concentration was 40.33 ± 3.09 % and 2.98 ± 0.90%, respectively. In addition, the mean value for the delta 13C and delta 15N was -28.11 ± 3.01‰ and 3.62 ± 2.80‰, respectively. This preliminary data indicates that vine traits exhibit a large variability at community-scales. Together with the elemental composition of leaves we will establish functional groups of vines that could be associated with their proliferation in a diverse array of habitats.

304

Life/Biological Sciences Presenter: Soriano, Berliza M.

Mentor: Rios Velazquez, Carlos

Title: Screening and Detection of Antimicrobial Agents Production Bioprospects, in Metagenomic Libraries from Aquatic Bodies in Puerto Rico

Authors: Berliza Marie Soriano (undergraduate student UPRM), Laura M. Del Valle Perez (graduate students UPRM), Carlos Ríos Velázquez (UPRM's Department of Biology faculty member)

Abstract

Antimicrobials have revolutionized human health care, but in recent years, their effectiveness has been diminishing. Over 70% of bacterial pathogens found in US hospitals are resistant to at least one antibiotic and more than 14,000 patients die annually from resistant nosocomial infections. Being aware of the enormous repercussions of this problem, and the scarcity of novel antimicrobials discovered by culture-dependent methods is necessary to implement culture-independent methods such as Metagenomics. For this, an antimicrobial agent production functional analysis methods were performed to four high molecular weight aquatic bodies metagenomic libraries (AML) generated from samples of Guajataca water reservoir (GWR- G1 and G2), Rio Grande de Añasco (RGA), Playuela Beach (PB). The functional screening was done using two assays: (1) overlay inhibition test and (2) Kirby Bauer assay (KBA). In the first test, 500 clones of the respective AML were spreaded on Petri plates with Luria Bertani (LB) and after 24 hrs of incubation, an overlay of Bacillus subtilis as target was done on top of the AML clones. A total of 1% of the clones per AML was screened for antimicrobial agents production. In the KBA, supernatants of the AML, one after centrifuging the un-lysed AML culture (S1) and the other one after lysing the AML culture (S2). After spreading B. subtilis on LB plates, 5mm individual disks impregnated with S1 and S2 were placed on top and incubated for 24 hrs. While no antibiosis halos were detected for S1, halos with variable inhibition zones were found in the S2 tested. For PB 35.7% of the disk demonstrated inhibition halos, for G1 14.3% inhibition halos, for G2 the inhibition ratio was 42.9 % and 36% inhibition ratio for RGA. These results demonstrated the reliability of Metagenomics in the discovery of antimicrobial products in these environments, representing an opportunity and a new alternative in solving the antibiotic resistant issue.

305

Life/Biological Sciences Presenter: Toro Domínguez, Daniel W.

Mentor: Hendricks, Timothy

Title: A Study of Phenotype of Mice With WT1 Gene Mutated

Authors: Daniel W. Toro Domínguez (Inter American University - Bayamón), Timothy Hendricks (Inter American University - Bayamón)

Abstract

The WT1 gene in mice is a gene that is expressed in a class of interneuron involved in locomotor behaviors, the dl6 interneurons (Andersson et al., 2012). The interneurons expressing the WT1 gene are inhibitory commissural interneurons. Mutation of the Wt1 gene in mice affects the differentiation of dI6 interneurons (Martinez and Hendricks, manuscript in preparation). Fewer dI6 interneurons are observed when the Wt1 gene is mutated. In the current proposal, we seek to address the question of whether there are additional phenotypic defects observed in the Wt1 mutant mouse. Inhibitory interneurons such as the dI6 produce gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter. Additionally they express glutamate decarboxylase (GAD65/67), an enzyme which is required for the biosynthesis of GABA. The transcription factor Pax2 is also expressed and is proposed to be an important determinant of the inhibitory interneuron phenotype (Batista and Lewis, 2008). We hypothesize that the levels of GABA, GAD65/67 and Pax2 will be altered in mice carrying a mutation in the Wt1 gene. We propose to collect wildtype, heterozygous and Wt1 null mutant E12.5 mouse embryos and determine the number of cells positive for these three markers by immunofluorescence. In addition we will examine the level of Vglut2 expression, a marker of excitatory neurons to determine if there is evidence of dI6 interneurons switching to an excitatory neurotransmitter phenotype. As a control, the expression of the V3 interneuron marker Nkx2.2 will be assayed. If the expression of GABA, GAD65/67 and Pax2 change in the mutated mice, we will seek to determine if the WT1 gene activate the expression of these markers in future studies.

306

Life/Biological Sciences Presenters: Torres, Patricia Resto Carrasquillo, Ivana N.

Mentor: Restrepo, Carla

Title: Temperature effects on late stage embryonic development in Eleutherodactylus coqui

Authors: Patricia Torres Santiago (Biology Department, University of Puerto Rico), Ivana N. Resto (Biology Department, University of Puerto Rico), Zuania Colón-piñeiro (Biology Department, University of Puerto Rico), Carla Restrepo (Biology Department, University of Puerto Rico)

Abstract

Developmental processes of many species can be disrupted by abiotic factors, including temperature. Changing temperatures not only can affect developmental times but also the external and internal morphology of individuals with variable consequences on their performance and fitness. Frogs with direct development - no tadpole stage - are an important component of tropical sites. Yet, their developmental trajectories and the extent to which temperature can influence these have been little studied. Our objective was to assess the effect of temperature on late embryonic development (stages 7 to 14 according to Townsend and Stewart 1985) of Eleutherodactylus coqui, a tropical frog with direct development. We collected egg clutches from captive coqui frogs, divided the eggs into three groups, and subjected them to three temperature treatments (20, 25, 30°C). Each developing embryo was photographed thrice daily until hatching. These photographs were used to identify the stage of each individual per time period and to collect measurements for eleven morphological characters. We used ANOVA and linear regressions to examine differences between temperature treatments. Our results show differences in developmental times, size, and morphological characters. Eggs subjected to 30°C temperatures developed faster than those at the other two temperatures. Likewise, yolk diameter (Yolk_diam) and eye diameter (ED) were larger in animals developing at 30°C than 20°C. Although not significant, we observed a trend towards larger head widths (HW) at 20°C. After reaching stage 9 we observed more variability in morphological; this is a stage when E.coqui features start to grow and develop in an accelerated manner. At this stage the tail is almost completely grown and limbs begin to develop faster aiding embryo movement. The observed morphological changes may have consequences on the performance and fitness of these frogs later in their life. Thus, under rising temperatures we might observe changes in the size and morphology of frogs.

307

Life/Biological Sciences Presenter: Torres Gutiérrez, Cesar

Mentor: Suarez, Edu

Title: The effect of Body Mass Index on Pain Levels of Patients with Fibromyalgia

Authors: Torres-gutiérrez Cj (University of Puerto Rico in Ponce), Merriwether En (University of Iowa), Rakel Ba (University of Iowa), Dailey Dl (University of Iowa), Abdelhamid R (University of Iowa), Sluka Ka (University of Iowa)

Abstract

Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread pain, depression, and mood and sleep disturbances. There is currently no consensus on the pathogenesis of FM. Overweight women are 60-70% more likely to develop fibromyalgia and experience more severe pain symptoms than normal women.Adipose cells release pro-inflammatory cytokines (IL-6, TNF-?, Leptin) that are linked to pain pathogenesis.This study aims to determine the relationship between weight or body mass index (BMI) and pain in fibromyalgia.A sample of 93 women was recruited for participation in a set of tests which classify the pain felt by the participants. Pearson Product Moment Correlation (r) analyses were done between BMI and the pain levels. One-way analysis of variance (ANOVA) was used to determine group differences in pain measures. For a sub-analysis consisting of 27 patients, blood samples were acquired from the participants. The Peripheral Blood Mononuclear Cell layer (PBMC) was isolated. Monocyte phenotype was determined using fluorescence-activated cell sorting (FACS) and a Pearson Product Moment Correlation (r) analysis was done. We found that there is no relationship between BMI, Pain levels and Monocyte phenotype.

Life/Biological Sciences Presenters: Torres Rodriguez, Orlando I Maldonado Laboy, Lizette Andrea

Mentor: Porter, James

Title: Fear Conditioning and Extinction Induce Plasticity of Ventral Hippocampus Synapses in the Medial Prefrontal Cortex

Authors: Omar Soler-cedeño (Basic Sciences Department, Ponce Research Institute , Ponce Health Sciences University, Ponce, PR.), Orlando I. Torres-rodríguez (Department of Science and Technology, Interamerican University of Puerto Rico Ponce Campus, Ponce, PR), Lizette Maldonado-laboy (Chemistry Department, Pontifical Catholic University of Puerto Rico 308

Ponce Campus, Ponce, PR.), Anixa Hernández (Basic Sciences Department, Ponce Research Institute , Ponce Health Sciences University, Ponce, PR.), James T. Porter (Basic Sciences Department, Ponce Research Institute , Ponce Health Sciences University, Ponce, PR.)

Abstract

Patients with posttraumatic stress disorder (PTSD) show impairments in discriminating safe and dangerous contexts. A useful approach for improving PTSD treatment is to study how contextual information modifies the neural circuits of the rodent brain during Pavlovian fear conditioning and extinction. Studies suggest that alterations in the synaptic communication between the ventral hippocampus (vHPC) and the medial prefrontal cortex (mPFC) could be important for the contextual modulation of fear responses. However, the precise synaptic changes occurring in the specific vHPC- mPFC circuit after fear conditioning and extinction have not been well studied. The mPFC is composed of the prelimbic (PL) and infralimbic (IL) cortices, which have opposed roles in fear expression. Therefore, we hypothesized that fear conditioning and extinction will induce differences in vHPC connectivity with PL and IL. We also hypothesized that extinguishing fear in the same context to that where the conditioning occurred will cause dissimilar synaptic changes than extinguishing the fear in a different context. To measure synaptic changes, we combined patch-clamp electrophysiology with selective optical stimulation of vHPC synapses in mPFC to record excitatory postsynaptic currents and presynaptic release of neurotransmitter. We found that fear conditioning induced postsynaptic plasticity in vHPC inputs to PL and IL. Same context extinction reversed the changes induced by fear conditioning in vHPC inputs to PL and IL, whereas different context extinction was less effective in reverting such changes. Taken together, these findings could explain why rodents renew an extinguished fear to a cue when experienced outside of the extinction context. Also, these findings provide a possible explanation for the relapse observed in some patients with PTSD after completing exposure therapy, which is normally conducted in a context different to that of the trauma.

Life/Biological Sciences Presenter: Valentin Acevedo, Antonio J.

Mentor: Planas, Jose

Title: Cytosolic versus Membrane Protein Profile of Guánica Salterns Halobacterias

Authors: Antonio J.valentín Acevedo (UPR-Aguadilla), Javier A. Valentín Acevedo (UPR-Aguadilla), José M. Planas Rivera (UPR-Aguadilla)

Abstract

Halobacterias are archeas that live in high salt concentration and they are found in Solar Salterns. Our laboratory has isolated a halobacteria from Guánica Solar Salterns and is involved in their molecular 309

characterization. Previous experiments suggest that it could be a different halobacteria, when compare results against Halobacterium salinarum, Haloferax mediterraneii and Halogeometricum borinquense. This investigation address the following problem: There are variations in the cytosolic versus membrane protein profile among these halobacterias. Our hypothesis is that based in previous experiments we should expect differences among them. To accomplish my objectives the following activities were carried out: (1) the preparation of halobacterias medium at 5M NaCl, (2) the growth of halobacterias at 37°C, (3) cytosolic and transmembrane proteins isolation by means of Acetone and Trichloroacetic acid (TCA) precipitation, (4) determination of protein concentration and (5) run an SDS-PAGE gel. I successfully completed these activities. I separated the cytosolic and membrane fractions by centrifugation at 14,000 rpm for 15 minutes. Protein isolation by TCA and Acetone was carried out and proteins concentration was determined by BCA. Protein concentration were confirmed by spectrophotometric method and the SDS-PAGE gel was standardized by concentration at 10ug/ul. The 10% SDS-PAGE showed that the cytosolic proteins range were from 185.5 Kd to 88Kd. This project will address a second phase which we will isolate total proteins and run 2D gels using a pH range from 2 to 11, and run a 10% SDS-PAGE.

Life/Biological Sciences Presenter: Vega Rosario, Emmanuel

Mentor: Garcia Arraras, Jose

Title: Decellularization Procedure for the Production of a Natural Acellular Intestinal Scaffold of Holothuria glaberrima Large Intestine.

Authors: Emmanuel Vega Rosario (Universidad de Puerto Rico- Rio Piedras)

Abstract

One of the areas of research most active in recent years is the development of decellularized organs as scaffolds for new organ formation. Decellularization is the process of removing all the cellular and nuclear matter from a tissue, preserving only its native extracellular matrix (ECM) from which the removed cells were naturally fixed. The ECM is mainly composed of macromolecular networks of proteins and glycoproteins such as collagens, fibronectin, and elastin. It provides support and protection to the cells and is related to various cell behaviors including: development, migration, proliferation, differentiation, adhesion, and wound healing. Our objective is to obtain a natural acellular scaffold with maximal preservation of the biological-architectural properties and macromolecular complexes found in the natural extra cellular matrix of the sea cucumber Holothuria glaberrima large intestine. The decellularization technique employed followed the principle of removing the cells form the tissue by immersing it in solutions of varying agents in a specific order. Thus, the large intestines of adult sea cucumbers were removed and subjected to immersion treatment with distilled water, followed by immersion in a solution of Triton-X , and finally treated with DNase-I enzymatic solution. The efficiency 310

of the procedure was inspected by histological and indirect immunofluorescence assays reporting minimal traces of nuclear remains as well as varying levels of preservation of mayor ECM structural protein complexes and bio-architectural properties. The decellularized intestines are now being probed as natural matrices for seeding cells that might form the new organ.

Life/Biological Sciences Presenter: Velázquez González, Yoheilly E.

Mentor: Suarez-Martinez, Edu

Title: Loss of Nf1 Function Causes Stereotypic Grooming Behavior in Drosophila melanogaster

Authors: Yoheilly Velazquez (University of Puerto Rico in Ponce), Seth M. Tomchik (The Scripps Research Institute Florida)

Abstract

Neurofibromatosis type 1 (NF1) is a common neurogenetic disorder characterized by the development of tumors in the nervous tissue, and 50-80% of patients suffer moderate to severe impairment in one or more areas of cognitive functioning. NF1 is highly comorbid with attention deficit-hyperactivity disorder (ADHD), and since ADHD shows dysfunction of dopamine (DA) neurotransmission, this suggests that Nf1 activity patterns may be altered in a dopamine-dependent manner as well. In previous experiments, we studied diurnal activity of Nf1 and dopamine transporter (DAT) mutants, and noticed intermittent peaks of activity, instead of an elevation of baseline activity. This led us to hypothesize that an increase in grooming behavior, rather than locomotion, may underlie the activity phenotype. To understand how Nf1 regulates activity, and to test for a link to dopamine signaling, we used high-resolution video tracking to examine head/eye, front legs, hind legs, abdomen, and wing grooming behavior in flies with loss of function mutations in the nf1 and dopamine transporter (DAT; fumin, fmn) genes. We found that loss of Nf1 function increases grooming behavior, specifically, head/eye grooming, while dopamine transporter (DAT) mutations increase locomotion, and reduces head/eye grooming. These results suggest that different molecular pathways underlie each phenotype. For future directions, studying how loss of candidate genes involved in the Nf1 signaling pathway affects behavior and how these genes regulate other known nf1 phenotypes will shed a light to understand the function of the Nf1 protein in the brain.

311

Life/Biological Sciences Presenter: Vergne Montes, Ralphdy

Mentor: Suarez-Martinez, Edu

Title: Tamoxifen affects in PLCg1 expression in ER+ breast cancer cells

Authors: Ralphdy Vergne Montes (University of Puerto Rico in Ponce), Carmen Ortiz Sánchez (Ponce Health Sciences University), Lenin Godoy Muñoz (Ponce Health Sciences University), Jaime Matta (Ponce Health Sciences University)

Abstract

Phospholipase C gamma 1 (PLCg1) can be found in the cytoplasm and in the nucleus of the cells and is involved in signal transduction pathways and proliferation. Previous data from our lab shows that PLCg1 expression in breast cancer cells is higher in comparison to non-tumorigenic cells. Also, oxidative stress- induced PLCg1 activation enhances cell survival. Many anticancer drugs can cause oxidative stress as a side effect, such as tamoxifen. Tamoxifen is currently used for the treatment of both early and advanced estrogen receptor positive (ER+) breast cancer in pre- and post-menopausal women. In addition, patients using tamoxifen have a higher probability to develop oxidative stress by consequence of the drug. Our aim is to compare and analyze PLCg1 expression in an ER+ breast cancer cell line (MCF-7) under the effect of tamoxifen. Our hypothesis is that there will be a high expression of PLCg1 in cells treated with tamoxifen in comparison to untreated cells. To achieve this, we cultured MCF-7 cells using complete media without phenol red and 4µM tamoxifen. After 24hrs, cells were lysed and protein and RNA were extracted. To determine PLCg1 expression we used a Taqman gene expression assay using GAPDH as housekeeping gene. Our results shows that PLCg1 expression was two times higher in MCF-7 cells treated with tamoxifen compared to untreated cells at 24 hrs. However, this effect was not statistically significant. This preliminary data indicates that the PLCg1 expression might be involved in ER modulation. Currently, we are developing an MCF-7 cell line resistant to tamoxifen to further study the changes in PLCg1 protein and gene expression upon acquired resistance.

312

Life/Biological Sciences Presenter: Vicens Lopez, Coralys

Mentor: Rios-Lopez, Neftali

Title: Drought-driven population dynamics of the Puerto Rican Mountain Coquí, Eleutherodactylus portoricensis from a mountain forest at the Sierra de Cayey

Authors: Coralys Vicéns-lópez (University of Puerto Rico - Humacao Campus), Eliacim Agosto- torres (University of Puerto Rico - Humacao Campus), Ashley Bernardi-salinas (University of Puerto Rico - Humacao Campus), Rayza M. Hernández-muñiz (University of Puerto Rico - Humacao Campus), Neftali Ríos-lópez (University of Puerto Rico - Humacao Campus)

Abstract

The Mountain Coquí, Eleutherodactylus portoricensis, is a mediun-large sized frog (mean SVL ~ 32.0 mm) found in high elevation forests at El Yunque and Sierra de Cayey. The species is designated Vulnerable by the Department of Natural and Environmental Resources of the Commonwealth of Puerto Rico and Endangered on the IUCN Red List. In a Cayey forest site, the Mountain Coquí is the most abundant Eleutherodactylus and shows a population phenology similar to other Eleutherodactylus in Pureto Rico: abundance varies with ambient temperature and rainfall, reaching the highest abundance during months of higher ambient temperature and rainfall (May to November), and decreases its abundance during months with lower temperature and rainfall (December to April). Between year 2014 and 2015, an extreme ?11-mo drought (July 2014 and April 2015), which equaled that between December 1974 and November 1975 in record, kept the amount of rainfall reaching to the leaf litter below that required to keep it a wet microenvironment suitable for frogs. Here we document the population variation in abundance for adults and juveniles and found that: (1) abundance of adults varied little between 2014 and 2015, but (2) abundance of small-sized juveniles (~8mm SVL) decreased >65% in 2015 compared to 2014 for the same period. Adults frequently engaged in water-conservative posture at periods of low ambient humidity, and abundance of adults showed little monthly variation in response to drought. In contrast, the drastic lag-time decline in abundance of small juveniles– presumably in response to drought–may have resulted from two processes: (1) either adults kept their breeding phenology relatively unaffected through time (i.e. breed in equal frequency year-round) and recently hatched and young juveniles died by being critically stressed in their rehydration capacity during this drought or (2) adults reduced their breeding activity and egg clutch production resulting in fewer juveniles by the onset of this drought. We have not found egg clutches at high portions of the vegetation in this forest and we believe that in this species, egg clutches are being deposited in the ground, within layers of the leaf litter (e.g., all egg clutches found so far in our study site have been deposited in artificial retreat sites placed on the ground). The decreased abundance of juveniles has profound consequences for the species' population dynamics: fewer recruits may replace adults by 2016, which could drive the species to population sizes with increased risk of local extinction in the event of another extreme climate disturbance in the immediate future.

313

Life/Biological Sciences Presenter: Vicente-Reyes, Jesica

Mentor: Chiesa, Ricardo

Title: Anxiolytic-Like Effects of Organic and Protein Extracts of Brown Seaweeds of the Coasts of Puerto Rico in the Behavior of Drosophila Melanogaster in the Dark/Light Box Test

Authors: Jesica Vicente Reyes (UPR Cayey), Jeslie M Ramos Cartagena (UPR Cayey), Angeliz Rivas Bonilla (UPR Cayey), Valeria Pedraza Baez (UPR Cayey), Alejandra Ferrer Diaz (UPR Cayey), Ricardo Chiesa (UPR Cayey)

Abstract

The main objective of this investigation is to determine if we can observe anxiolytic-related effects of organic and protein extracts obtained of brown seaweeds of the coast of Puerto Rico in a model of anxiety in Drosophila Melanogaster. We will use the behavioral paradigm of the Dark/Light box as an innate behavior with anxiety-like characteristics. This behavior can be used as an anxiety paradigm because is an innate behavior of the fly to spend more time in the dark side of the box, while crossing or exposing part of her body to the illuminated side of the box is a measure of exploratory (less anxiety) behavior. To perform the assay, an acrylic box was constructed and was divided in two halves: one painted with black nail polish while the other was left completely transparent. Five males and five females flies are going to be used as the control group and their behavior will be recorded for fifteen minutes, using the last five minutes for the analysis. Exploratory (less anxiety-like) behavior is scored when the head and at least part of the torso is on the side with light. The experimental group (five females and five males) will consist of flies exposed to 1 ml of crude seaweed organic extract since the embryo stages. The procedure for the behavioral measurements will be the same as with the control group. The results of both groups will be compared and quantitatively analyzed. Our experimental hypothesis is that flies exposed to the crude organic extract will show less anxiety in this behavioral paradigm, and that would be assessed by the number of visits to the illuminated side of the box.

314

Life/Biological Sciences Presenter: Vilanova Vélez, Luis

Mentor: Martinez-Cruzado, Juan

Title: Demographic study of MET polymorphisms associated with autism spectrum disorders in Puerto Rico

Authors: Luis Roberto Vilanova-vélez (University of Puerto Rico at Mayaguez), Juan Carlos Martínez-cruzado (University of Puerto Rico at Mayaguez)

Abstract

Autism spectrum disorders (ASDs) are a complex, highly heritable (90%) group of neurodevelopmental disorders. It involves different levels of disability, from barely noticeable, to severe, affecting 1 in every 68 children born in the United States. However, the incidence in Puerto Rico is 42% higher. Nearly 700 genes distributed across all chromosomes have been associated to ASDs. Furthermore, studies have identified a region in chromosome 7q as the autism susceptibility locus 1 (AUTS1). Specifically, three single nucleotide polymorphisms (SNPs), rs1858830, rs38841, and rs38845, near the 5' UT region of the gene MET, located in the locus 7q31, have been identified to affect its expression, and increase the risk of developing ASDs. Its signaling have a function in cerebral cortex and cerebellum development, both seen disrupted in autistic children. The Island is an ideal venue to study the genetic patterns of ASDs due to the dramatic increase of autism diagnosis and the genetic diversity of the population. Thus, using the data of the 104 Puerto Ricans sequenced in the third phase of the 1000 Genomes Project we analyzed using haplotype blocks and dbSNP the SNPs in the gene MET. The ASDs associated alleles of these three SNPs were generally distributed in the Puerto Rican population with a frequency of 54%, 61%, and 42%, respectively. All the haplotypes were present in the population, specifically, the haplotype with the three alleles associated to ASDs had a frequency of 0.12. No association with one of the ancestral populations was observed. We hypothesized that the SNPs should be uniformly distributed across the Puerto Rican population, however, the three alleles associated with ASDs should be enriched in a representative sample of the autistic Puerto Rican population. The genetic diversity of the Puerto Rican population creates an ideal venue to understand the patterns that involve an increased risk to develop ASDs, link them to the Island's ancestral constituent populations and identify associations with environmental factors.

315

Life/Biological Sciences Presenter: Williams Mestre, Shane

Mentor: Matchett, Ash

Title: Optimizing DNA Extractions for Fossilized Samples Recovered from Tropical Environments

Authors: Shane Williams (UIA-BAYAMON), Ashley A Matchett (UIA-BAYAMON)

Abstract

DNA extractions from fossilized remains has a turbulent history of successes and failures and remains a controversial topic. The successful recovery of DNA from these remains, simply called as ancient DNA, is important for archeological, and historical investigation, and allows us to trace back human, and animal origins. It however remains a difficult and challenging undertaking, predominantly due to the trace quantity of DNA present in the sample, poor quality of the template DNA, high level of possible contaminates and a plethora of associated biological artifacts that inhibit subsequent DNA amplification. DNA amplification, through procedures such as PCR has made the analysis of trace DNA a reality, and, along with further developments in the areas of DNA manipulation and Next Generation Sequencing has allowed great progress in the understanding of the early history of humans and human activity.

Despite recent developments in the field, the core component issues encountered in early studies remains the same, how to successfully extract, the maximum quantity of the trace DNA, in the best condition, with the minimum of contamination and inhibiting artifacts. In brief the initial sample DNA extraction remains pivotal for successful DNA analysis, furthermore in tropical samples, which generally show high degrees of degradation, due to predominant environmental conditions.

It is the objective of this study to optimize the Extraction and purification procedures, specifically for the challenging samples encountered in the bio-archaeological remains of Puerto Rico and the Caribbean.

This study will demonstrate through a number of assays, recent advances and outcomes of a comparative series of techniques in the decalcification, digestion and purification steps of a number of local ancient DNA samples of historical interest in order to ascertain the highest recovery, quality and minimal handling of ancient DNA samples.

All samples were assayed under stringent clean room conditions in a specifically designated facility, under controlled access and dedicated resources to reduce possible contamination events. In order to optimize these initial experiments and detect possible human contamination issues, all samples were of non-human, albeit historical, origin. Through these results we hope to show, not only the possibility, but a robust method of recovering high quality DNA from suitably preserved remains from Tropical environments.

317

Mathematics 319

Mathematics Presenters: COLON, KIARA Luna, Nathalie M.

Mentor: Suazo, Erwin

Title: Modeling Wave Phenomena using Riccati-System to Construct Nonlinear Schrödinger Equations

Authors: Kiara Colon (UPR-Mayaguez), Nathalie Luna (UPR-Mayaguez), Erwin Suazo (UPR- Mayaguez)

Abstract

Transformations are used in order to construct Nonlinear Schrödinger equations admitting bright, dark and Peregrine soliton solutions. We find explicit solutions for a nonlinear Riccati system with selected variable coefficients to construct the transformations. NLS is the standard model of how light propagates inside of a fiber optic with rich mathematical properties such as being integrable. Some of the most important applications are rogue waves, pulse dynamics in the dispersion-managed fibers and Bose-Einstein condensates.

Mathematics Presenter: De Jesus Pagan, Francisco J.

Mentor: Ortiz-Albino, Reyes

Title: Ordered Factors

Authors: Dr.reyes M. Ortiz-albino (University of Puerto Rico, Mayaguez), Francisco J. De Jesús Pagán (University of Puerto Rico, Mayaguez)

Abstract

Between 2004 and 2006, Anderson and Frazier defined the concept of a T-factorization on an integral domain D. With this they generalized the theory of non-atomic factorizations over domains. Anderson and Frazier considered T to be a symmetry relation over a set of nonzero and nonunit elements of an integral domain. If T is considered to be an order relation then the notion of a T-factorization or a T- product is an example of ordered factorizations, defined but never been studied before. We study such type of factorizations and some number theory properties as: the existence of the greatest common T- factor of any two nonzero nonunit elements, and the least common T-product. We will focus on the 320

integers, but this can be easily generalized to a PID. We give examples and characterized some behaviors.

Mathematics Presenter: Galan Rivera, Jean C.

Mentor: Torres-Saavedra, Pedro

Title: Investigating Crime Data in Puerto Rico through Statistical Analyses

Authors: Jean C. Galan-rivera (UPR-MAYAGUEZ), Pedro A. Torres-saavedra (UPR-MAYAGUEZ)

Abstract

In an exploratory analysis of PR crime data reported by the police department in 2014, we found that Bayamon is the police region with the largest number of crime events (12,411 crimes) and the second largest crime rate (1,849 crimes per 100,000 inhabitants). Because of its high crime prevalence, we are focusing our analyses in this region. Using a descriptive data analysis, we found that theft is the most frequent type of crime (6,696 crimes, 53.95%) in the region; more than the double of the second type of crime that has occurred, which is burglary (2,453 events, 19.76%). The period between 7:00pm and 8:00pm exhibited the largest number of crimes in Bayamon with 685 crimes (5.5%). In average, about 1.32 crimes occurred per hour in the region. Using georeferentiation we found that the mean centre of the data was located at Bucarabones, Mucarabones, Toa Alta, 00949. The data is clearly clustered in certain areas and boroughs showing some crime hotspots. The original data had location information in decimal degrees coordinates, so a transformation to eastings/northings coordinates was necessary in order to interpret intensity results in metric units. We used kernel-smoothing techniques to analyze the spatial distribution of crime intensity. To determine the optimal bandwidth for the kernel smoothing we used the Least-Squared Cross-Validation (LSCV) criterion. LSCV found that 12 hectometers is the optimal bandwidth for the kernel smoothing of the study region. We found that crime intensity changes by month, but the crime hotspots remains almost equally distributed spatially across time. The results of this research will lead to better understanding of crime pattern in this region and could be used to design public policies by the police department and policymakers.

Acknowledgement: This research was sponsored by the Puerto Rico Louis Stokes Alliance for Minority Participation (PR-LSAMP) research program.

Keywords: data analysis, statistics, point-pattern analysis, RStudio.

321

Mathematics Presenter: Martínez Oquendo, Pamela D.

Mentor: Vázquez González, Wanda

Title: El aspecto matemático de figuras y nombres dados a las mismas por niños de una escuela elemental

Authors: Pamela Martínez Oquendo (PCUPR)

Abstract

Al comparar pseudopalabras como "bouba" y "kiki" con figuras puntiagudas y redondas, el 98% de la muestra pareó la palabra "bouba" con la figura redonda y "kiki" con la figura puntiaguda (Köhler, 1947). Estos resultados me inspiraron a investigar el aspecto matemático de figuras y nombres dados a las mismas por niños de una escuela elemental. Esto se hará comparando la curvatura de figuras y de las palabras creadas por niños para esas figuras y ver cuán cercana o lejana están una de la otra. Se pretende responder si existe relación entre la curvatura de las figuras y el nombre creado por niños de escuela elemental. Se escogerá una muestra de aproximadamente 300 estudiantes de una escuela elemental pública de los grados de primero a sexto. A los estudiantes se le administrará un cuestionario que consta de dos figuras. Los estudiantes crearán un nombre para cada figura. Las figuras se coordenalizarán usando el programa Geogebra y se escogerán puntos de los cuales se obtendrá la curvatura. Luego usaremos el promedio de esas curvaturas puntuales como curvatura de la figura. Haremos lo mismo con las letras del abecedario. Al final se calculará la curvatura de las palabras utilizando el promedio de curvaturas de las letras usadas y se compararán los resultados con la curvatura de la figura correspondiente. Finalmente, se determinará si se asemejan estas medidas.

322

Mathematics Presenters: Rivera-Lopez, Yesenia M. Velazquez Reyes, Genesis R.

Mentor: Candelaria Soberal, José

Title: caveGEOmap: MATLAB Code Implementations in Order to Create 3 Dimensional Maps for Territorial Caves

Authors: Yesenia Marie Rivera-lopez (University of Puerto Rico - Arecibo), Genesis Velazquez- reyes (University of Puerto Rico - Arecibo)

Abstract

caveGEOmap is a code to create 2D and 3D maps of caves developed in MATLAB, a high-level technical computing language with interactive environment. Mapping is significant when studying caves, which is used to produce a territorial aspect map. Preliminary exploration takes place in the cave, where the required data is collected in order to produce the maps. During this project, real cave data were used which contains coordinates of altitude and azimuth latitude, and longitude. The main objective, of this project, is to create an easy to use and cost-efficient software for the scientific community. For this project, implementations to the MATLAB code were made; for caves that contains more than one path/ramification territorially or data that contains the same range values of X, and Y axis. We adjusted the code to several cases that can be found during the compilation of data: 1) a cave inside a cave [an overlap], 2) a partial overlap or 3) separated data.

Mathematics Presenter: Rosado Perez, Michelle N.

Mentor: Rios-Soto, Karen

Title: A Mathematical Epidemiological Model to Study the Impact of the Prodrome Period on Herpes Simplex Viruses Epidemics

Authors: Michelle N. Rosado Pérez (University of Puerto Rico, Mayaguez), Emmie Román Meléndez (Univeristy of Puerto Rico, Mayaguez), Luis Almonte Vega (University of Puerto Rico, Mayaguez), Luis Ramos Soto (University of Puerto Rico, Mayaguez) 323

Abstract

Herpes Simplex Viruses (HSV-1 and/or HSV-2) has reached epidemic proportions worldwide in recent years. HSV are an infection of the skin transmitted by direct contact with the infected area. HSV-1 commonly establishes in the orofacial area, but only 5-10% in the genital area. On the other hand, HSV- 2 typically establishes in the genital area. There is no known cure for HSV, but the viruses are not active nor contagious all the time, quiescent (dormant) stage. Six to forty-eight hours before visible lesions, HSV are in the prodrome period, where the individual may be infectious and experience constitutional symptoms. There are several bio-mathematical studies on HSV-2, but only few in HSV-1, and none that includes the prodrome period explicitly. The objective of this work is to built a mathematical epidemiological model of non-linear ordinary differential equations to study the impact of the prodrome period on new HSV infections. The model stratifies the population into susceptible individuals, HSV infectious individuals (with lesions), individuals on the prodrome period under primary infection, individuals on the prodrome period under reactivation of the virus and individuals in quiescent state (non-infectious). At this preliminary stage we investigate the system equilibria, the basic reproductive number and other partial results through simulations.

Mathematics Presenter: Rosario Santos, Angelica M.

Mentor: Cruz Aponte, Maytee

Title: Epidemiological model of Chikungunya with climatological variables

Authors: Angélica M. Rosario Santos (Universidad de Puerto Rico en Cayey)

Abstract

According to the Department of Health of Puerto Rico, the Chikungunya epidemic began in May 2014, by the end of this year about 27, 000 suspected cases of 4,335 which were recorded were confirmed with only 15 deaths associated with the virus. During this semester we studied different strategies to consider temperature variables in an SIR-type model type we constructed for this vector born disease. In order to accomplish this, we extracted the temperatures recorded for San Juan, Aibonito and Guayama in 2014 from the NOAA. The life cycle of the vector is linked to several climatic factors, including temperature during the summer. The temperature in the summer mainly promotes the speed of development of the immature insects and precisely 2014 was the third year registered highest temperatures during that period in Puerto Rico. Researches by various authors show a correlation between the parameters related to the vector's life cycle and temperature. Using these equations we determine the vector function capability, which is the average of new cases generated per unit time for infected case introduced in a fully susceptible population during the infectious period. According to our preliminary results we conclude that most of the cases registered in Aibonito were exported and in the cases of San Juan and Guayama the temperatures where ideal for the development of the mosquito. In 324

addition, we consider the population of vectors and hosts to calculate the basic reproduction number. According to our results, two people can become infected if an infected vector and an infected human host are introduced to fully susceptible population.

325

Pharmaceutical Sciences

327

Pharmaceutical Sciences Presenters: Cruz-Lebron, Junellie L. Ortiz Hernandez, Christian J.

Mentor: Fasoli, Ezio

Title: Cellulose membranes for protein purification

Authors: Junellie Cruz Lebrón (Department of Chemistry University of Puerto Rico at Humacao), Christian Ortiz Hernandez (Department of Chemistry University of Puerto Rico at Humacao), Zurisadai Rivera (Department of Chemistry University of Puerto Rico at Humacao), Vibha Bansal (Department of Chemistry University of Puerto Rico at Cayey), Rolando Oyola (Department of Chemistry University of Puerto Rico at Humacao), Ezio Fasoli (Department of Chemistry University of Puerto Rico at Humacao)

Abstract

Plasminogen activators are important therapeutic proteins used as emergency thrombolytic agents for the treatment of thrombovascular disorders such as myocardial infarction and stroke. The separation and purification of these proteins from complex mixtures of cell cultures is a challenging task due to the lack of efficient and suitable processes available. The objective of this study is to synthetize new affinity cellulose membranes which can selectively bind plasminogen activators with the aim of developing a fast, efficient, and economic viable purification method.

Cellulose membranes with different pore size distribution and with different ligand density were synthetized using epichlorhydrin as spacer arm and para-aminobenzamidine (pABA) as selective ligand for binding of plasminogen activator. The chemical modification of cellulose membrane was confirmed by FTIR spectra.

In order to quantify the amount of pABA linked to the membranes, a new fluorescence analytical technique was developed. The method is based on the reaction of the amidine moiety with sodium glyoxal and benzaldehyde. The so formed adduct had maximum excitation at 405 nm and emission at 620 nm. The technique was first optimized in liquid and then in solid phase, showing a linear correlation between pABA concentration and fluorescent emission which allow us the determine the ligand density on the cellulose membranes.

328

Pharmaceutical Sciences Presenter: Mooney-Garozzo, Joseph W.

Mentor: Sanabria, David

Title: Synthesis of alkynoic fatty acids and evaluation their conjugation-inhibitory activity of the antibiotic resistance-conferring plasmid R388 among Escherichia coli strains

Authors: Joseph W. Mooney-garozzo (Department of Natural Sciences, Inter American University of Puerto Rico-Metropolitan Campus), Yaritza Rivera (Department of Natural Sciences, Inter American University of Puerto Rico-Metropolitan Campus), Christian Morales (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus), Fernando De La Cruz (Molecular Biology Department, Universidad de Cantabria), Néstor M. Carballeira (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus), David Sanabria-ríos (Department of Natural Sciences, Inter American University of Puerto Rico-Metropolitan Campus)

Abstract

Antibiotic-resistant (AbR) bacteria pose a colossal threat to global health as they are poised to undermine the efficacy of life-saving treatments for infections that modern medicine had previously been able to efficiently abate. Biomedical innovations to halt or slow the spread of AbR are drastically needed. Due to the antibacterial and conjugation-inhibitory (COIN) activity of 2-hexdecynoic acid (2- HDA), synthesis and assays to test the COIN of HDA analogs were implemented. The obtention of these analogs was accomplished in four steps that included, 1) the tetrahydropyranyl protection of a primary alcohol with a terminally brominated carbon; 2) coupling with a terminal alkyne in the presence of n- BuLi; 3) deprotection of the THP-protected alkynol to yield hexadecyn-1-ol; and 4) oxidation of hexadecyn-1-ol to afford the desired HDA. This synthetic route was used to obtain 9-, 10-, and 12-HDA with minimal variation in procedure or efficiency, and overall yields were, respectively, 16%, 30%, and 17% from starting materials. Some of these alkynoic fatty acids were subjected to plate-mating conjugation assays with two strains of Escherichia coli in order to test the conjugation frequency of the AbR-conferring plasmid R388. Preliminary findings revealed that 2-HDA and 12-HDA showed conjugation frequencies of 3% and 14%, respectively. Thus, our data show that analogs of 2-HDA exhibit interesting COIN activity suggesting that further studies of COIN activity of other alkynoic fatty acids are needed to provide the groundwork to develop novel antibiotic cocktails chemically equipped to inhibit the conjugation of AbR-conferring plasmids.

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Pharmaceutical Sciences Presenters: Ortíz Torres, Desire M. Hernández Espinell, José R.

Mentor: Stelzer, Torsten

Title: Polymorphism in Polymer-Based Solid Dosage Formulations

Authors: Desire M. Ortiz Torres (UPR- Rio Piedras Campus), José R. Hernández Espinell (UPR- Rio Piedras Campus), Vilmali López-mejías (UPR- Rio Piedras Campus; Molecular Science Research Center), Torsten Stelzer (UPR-MEDICAL SCIENCE CAMPUS)

Abstract

To replace cost and time intensive conventional batch dominated pharmaceutical solid dosage formulation processes, the pharmaceutical industry is interested in exploring new manufacturing technologies such as polymer-based extrusion processes that enable continuous formulation of complex products for peroral administration. The determination of the thermodynamic and kinetic behavior as well as the interactions of drug-polymer blends are critical process parameters (CPP), which affect critical quality attributes (CQA) such as crystal size, distribution, morphology, polymorphism, and phase purity. Polymorphism, a phenomenon that enables molecules to exhibit multiple crystalline phases, is one of the most scrutinized CQA during the manufacturing of solid formulations. Polymorphism is estimated to occur in over 80% of molecules that display a pharmaceutical application, affecting primarily their solubility, which correlates with their bioavailability. The inadvertent occurrence of solid- state phase transformation events during an extrusion process of crystalline pharmaceutical solids dispersed in a molten polymer and the careless (re)crystallization of dissolved or molten pharmaceutical compounds subsequent to an extrusion process can lead to undesired polymorphs, which might have an adverse effect on the product's properties, such as solubility and bioavailability. Therefore, investigating the effects of these CPP is of outmost importance to control CQA of the produced formulation, as well as facilitating the translation of extrusion processes into a continuous manufacturing setting with broader applications. This study presents (1) thoroughly characterized thermodynamic behavior of drug- polymer blends of different compositions including recrystallization and (2) understanding of solid phase transition kinetics of drug-polymer blends at different temperature and exposure times in simulated extrusions. Moreover, it will be demonstrated that the polymorphism and its control is crucial in polymer-based extrusion formulation processes.

331

Physics 333

Physics Presenter: Adames, Ruth

Mentor: Morell, Gerardo

Title: Nitrogen-Doped Graphene-Electrodes for Electrophysiological Recordings

Authors: Ruth L. Adames Méndez (University of Puerto Rico, Río Piedras Campus), Samuel Escobar (University of Puerto Rico, Río Piedras Campus), Frank Mendoza (University of Puerto Rico, Río Piedras Campus), Gerardo Morell (University of Puerto Rico, Río Piedras Campus)

Abstract

We report the study and development of graphene-based flexible cutaneous electrodes that are suitable for short- and long-term contact with the skin for physiological recordings. Nitrogen-doped graphene layers were grown on copper foils by Hot Filament Chemical Vapor Deposition (HFCVD) technique and transferred onto polyimide substrate (Kapton) that contains patterned gold contacts integrated to PEDOT:PSS (conductive polymer). The performance of these electrodes was assessed at 1 kHz. The graphene electrodes show lower impedance in comparison with Ag/Al-based electrodes, which can be useful for medical large data that involve long periods of time. The study wants to demonstrate that nitrogen-doped graphene remains stable, inert, and suitable for wearable medical devices intended for long-term electrophysiological recordings.

Physics Presenter: Diaz Aponte, Kevin O.

Mentor: Vedrine, Josee

Title: Lab-VIEW interface and automatization software for measure the resistance per square unit of organic films

Authors: Kevin O.diaz Aponte (UPR - Humacao), Grabriel A. Calderon Ortiz (UPR - Humacao), Josee Vedrine-pauleus (UPR - Humacao)

Abstract

Process automatization measures experiments in a manner more efficient than manual measurements. So we are looking to automate and standardize laboratory instruments, controlling them with a computer program that measures the resistance of thin films composed of metals and semiconducting polymers. The problem is that we do not know the resistance per square unit of the films made of P3HT, 334

PCBM and ICBA. To measure the physical characteristics of the films, have to use the technique of four points. This technique works by four simultaneous aligned prove on the sample by the ends proves crosses a current and the half prove measure a voltage. To facilitate and minimize measurement errors, I work on program designing in Lab -View to measure the resistance per square unit of the films made of P3HT, PCBM, ICBA with greater ease and lower percentage of possible error.

Physics Presenter: Espinosa, Gabriela Lynnette

Mentor: Muller, Rafael

Title: Research and Measurement of Binary Stars

Authors: Rafael J. Muller Porrata (University of Puerto Rico in Humacao), Juan C. Cersosimo (University of Puerto Rico in Humacao)

Abstract

Our job it's to measure Binary Stars selected by the Washington Double Star Catalog. The data that we receive comes from a 31 inch Schminal-Cassegrain Nuro Telescope from Flagstaff, Arizona. This 31 inch Schminal-Cassegrain Nuro Telescope was built by AstroMechanics. Following the standard procedure to calibrate the images, we pixelate the images to measure the separation of the Binary Stars system also measuring the angle of the star system. We use a software to check our results for any error. Then our data it's published at the Washington Double Star Catalog. This research project is part of the ongoing data gathering investigation that has been active from several years.

Physics Presenter: Morales Vicéns, Jorge

Mentor: Lysenko, Sergiy

Title: Nucleation dynamics of new phase near the transition point of vanadium oxides

Authors: Dr. Sergiy Lysenko (University of Puerto Rico - Mayagüez), Dr. Armando Rúa (University of Puerto Rico - Mayagüez), Jorge Morales Vicéns (University of Puerto Rico - Mayagüez) 335

Abstract

Vanadium dioxides can exhibit both conductive and insulating behavior, depending to the temperature at which it are exposed. This property makes vanadium dioxides invaluable materials with many applications in Science and Technology fields. Among many of the physical changes that occur on the insulator-to-metal phase transition, it can be noted both a rate of change of the number of nuclei per unit area with respect to temperature and a rate of change of the average size of the nuclei with respect to temperature. Therefore, this work will focus on studying quantitatively those changes, in order to obtain more information about the energetic changes of vanadium dioxides during the insulator-to- metal phase transition.

Physics Presenter: Passalacqua Alvarado, Normarieli M

Mentor: Martinez Valdes, Ricardo

Title: Development of electrospun multiferroic nanofibers (Synthesis, microstructure, characterization and applications)

Authors: Dr. Ricardo Martínez Valdés (University of Puerto Rico at Cayey)

Abstract

This project is focused to the combination of the electrospinning technique and sol-gel route to synthetize continuous and functional ceramic nanofibers from various ferroelectric and ferromagnetic materials. In electrospinning of ceramic nanofibers, conventional sol–gel precursors are prepared first, then mixed with the polymer poly(vinyl pyrrolidone) (PVP) directly and stirred continuously to form homogeneous electrospinning solutions. In this manner is possible to integrate ferroelectric/ferromagnetic phases for fabricating multiferroic nanocomposites and then to investigate their structural and physical properties. The main focus of this research is the control of nanoscale structures in nanofibers and understanding how to utilize them for the applications in novel multiferroic devices much as to develop the technical and scientific expertise required to exploit their potential. The research has an interdisciplinary nature in the field of physics, chemistry, materials science and engineering. This project is carried out thanks to the equipment and facilities of University of Puerto Rico at Cayey and Rio Piedras campuses and is aligned with NASA vision for space exploration: development of new materials with robust and stable physical and chemical sensing properties for devices operation in harsh conditions and low power consumption faster electronics devices. In the initial stage of this project our efforts have been focused on the synthesis, structures and morphology of lead free nanofibers based in ferroelectric materials as barium titanate (BaTiO3 ? BTO). Below are some of our first results and achievements.

336

Physics Presenter: Pérez Gómez, Francisco J.

Mentor: Martinez Valdes, Ricardo

Title: Development of electrospun multiferroic nanofibers (Synthesis, microstructure, characterisation and applications)

Authors: Dr. Ricardo Martinez Valdés (Universidad de Puerto Rico recinto de Cayey), Normarieli Passalacqua Alvarado (Universidad de Puerto Rico recinto de Cayey), Francisco Javier Pérez Gómez (Universidad de Puerto Rico recinto de Cayey)

Abstract

This project is focused to the combination of the electrospinning technique and sol-gel route to synthesise continuous and functional ceramic nanofibers from various ferroelectric and ferromagnetic materials. In electrospinning of ceramic nanofibers, conventional sol–gel precursors are prepared first, then mixed with the polymer poly(vinyl pyrrolidone) (PVP) directly and stirred continuously to form homogeneous electrospinning solutions. In this manner is possible to integrate ferroelectric/ferromagnetic phases for fabricating multiferroic nanocomposites and then to investigate their structural and physical properties. The main focus of this research is the control of nanoscale structures in nanofibers and understanding how to utilise them for the applications in novel multiferroic devices much as to develop the technical and scientific expertise required to exploit their potential. The research has an interdisciplinary nature in the field of physics, chemistry, materials science and engineering. This project is carried out thanks to the equipment and facilities of University of Puerto Rico at Cayey and Rio Piedras campuses and is aligned with NASA vision for space exploration: development of new materials with robust and stable physical and chemical sensing properties for devices operation in harsh conditions and low power consumption faster electronics devices. In the initial stage of this project our efforts have been focused on the synthesis, structures and morphology of lead free nanofibers based in ferroelectric materials as barium titanate (BaTiO3 BTO).

337

Physics Presenter: Sepulveda Medina, Pablo I.

Mentor: Pinto, Nicholas

Title: Electrical response of monolayer MoS2 to vapors of aliphatic alcohols

Authors: Pablo I. Sepulveda Medina (University of Puerto Rico-Humacao), Idalia Ramos (University of Puerto Rico-Humacao), Carl Naylor (University of Pennsylvania), A.t. Charlie Johnson (University of Pennsylvania), Nicholas Pinto (University of Puerto Rico- Humacao)

Abstract

Monolayer MoS2 crystals were used to sense vapors of Methanol, Ethanol and 1-Propanol. Due to the large surface area, these sensors are expected to show rapid response and recovery times. The current through the sensor was monitored as a function of time with a constant applied voltage. This current decreased in the presence of the sensing gas and recovered upon its removal. Our results show that the response time gets longer as the size of the alcohol increases, but the recovery time stays approximately the same (\textasciitilde 20s) regardless of the size of the alcohol. The sensitivity was also seen to decrease as the size of the alcohol increased. These observations could be associated with the slower diffusion of the larger alcohol molecules into the MoS2 crystal. The sensors are also fairly robust since the same sensor was used in all of the measurements after annealing in air at 70C for 10 minutes. Additional sensing measurements as a function of gas concentration will also be presented.

Physics Presenter: Toro De Leon, Steven J.

Mentor: Furlan, Rogerio

Title: Formation of Nano Fibers Containing Aloe Vera Using Electrospinning

Authors: Steven J. Toro De Leon (University of Puerto Rico at Humacao)

Abstract

Aloe vera is an herb that promotes skin regeneration and is known to be effective in the treatment of various wounds. It is a promising material to be incorporated in nanofibers, aiming at tissue engineering. Many of the health benefits associated with aloe vera have been attributed to the 75 potentially active constituents of the plant, including: vitamins, enzymes, minerals, sugars, lignin, 338

saponins, salicylic acids and amino acids. This healing property is possible because of the presence of polysaccharides.

In this work we are studying the formation of polymeric nanofibers containing aloe vera using electrospinning, aiming at to explore the effects of nanostructured materials. Electrospun nanofiber mats/webs exhibit a number of outstanding properties such as high surface area compared to film, light weight and high porosity, which can improve wound healing. Commercial aloe vera (Fruit of the Earth, Inc., natural, 99.8% pure) was used to dissolve the polymer. A fixed amount of aloe vera (10 ml) was used for all cases. Different types of polymers were investigated, including Cellulose Acetate, Polyvinylidene Fluoride (PVDF), Poly (ethylene oxide) (PEO), and Poly (ethylene glycol) (PEG). Solutions/dispersions with different concentrations were prepared. It was verified that solutions with Cellulose Acetate resulted very heterogeneous, PVDF was either difficult to dissolve or formed agglomerates, PEO had a trend to form viscous solutions but at the same time with a proper flow, and PEG dissolved easily, but the solution was too liquid. Based on this preliminary analysis, solutions containing aloe vera (10 ml) and PEO (0.2g) were prepared and used for electrospinning. Conventional electrospinning was used with voltages between 15 kV and 20 kV and distances between the tip of the syringe and collector (aluminum foil) of 20 and 25 cm. The figure below presents images of typical microfibers deposited under these conditions. Further work will be focused on exploring conditions to obtain aligned nano fibers.

Physics Presenter: Ulloa Machado, Josue J.

Mentor: Mendez-Tejeda, Rafael

Title: Diurnal Temperature range in Puerto Rico 1950-2014

Authors: Mendez-tejeda Rafael (University of Puerto Rico at Carolina), Ulloa-machado Josué (University of Puerto Rico at Carolina)

Abstract

This paper presents an analysis of the variability of daily maximum and minimum temperatures in thirteen meteorological stations located in different climatic zone of Puerto Rico. We found a negative trend in the Diurnal temperature Range (DTR) in twelve of the stations studied, this trend is mainly caused by an increase in the trend of minimum temperature greater than the maximum temperature in some cases this increase reach be three times higher.

We also study the behavior of the amount of warm days versus the amount of cold days in 6 decades, increasing finding a significant decrease in the number of cold day ( 32 °C) . Which leads us to conclude that climate is changing island.

339

51st ACS Junior Technical Meeting 36th Puerto Rico Interdisciplinary Scientific Meeting (PRISM)

Poster Session

Titles for Poster Sessions (Arranged in Alphabetical order by field and presenter´s last name)

● Chemistry

● Engineering

● Environmental Sciences

● General Sciences

● Geosciences

● Life/Biological Sciences

● Mathematics

● Physics

341

Chemistry 343

Chemistry Presenter: Acosta Santiago, Maxier

Mentor: Rivera Ortiz, Jose

Title: Synthesis and Self-Assembly Studies of Potentially Immunomodulatory Particles made from Guanosine Derivatives

Authors: Maxier Acosta-santiago (University of Puerto Rico, Rio Piedras Campus), Milagros I. Rivera-cora (University of Puerto Rico, Rio Piedras Campus), Jose M. Rivera-ortiz (University of Puerto Rico, Rio Piedras Campus)

Abstract

Immune system modulation is a strategy used for a variety of purposes, such as immunotherapy for anticancer treatment, as adjuvant for vaccines among others. In this field of research particles are emerging to become an important tool of immunomodulation. Yet for most immunomodulating particles to a become viable option for clinical applications, significant challenges must be overcome, like: unreliable properties, high costs of manufacturing in large scales, significant complications due to low yields and difficult purification. We have developed a family of colloidal particles made from guanosine derivatives we term Supramolecular Hacky Sacks (SHS). SHS are suitable for the encapsulation and cellular delivery of a number of biologically active molecules including anti-cancer drugs, polysaccharides, DNA and proteins. Preliminary results of this system also show to have Immunostimulatory activity in vitro and in vivo. This has become decisive information for us to start exploring SHS as a viable immunomodulatory system. We aim to develop a new library of SHS particles to understand it's immunomodulatory properties. In this presentation we will show the initial results of the synthesis and characterization of a small library of 8ArG derivatives that will eventually be used to establish structure activity relationships (SAR) between the resulting SHS and their immunological activity. We expect the resulting new particles to have applications in the field of vaccine delivery.

344

Chemistry Presenter: Belfleur, Luxene

Mentor: Rivera, Jose

Title: Interrogation in vitro of supramolecular colloidal particles made from guanosine derivatives using Raman spectroscopy

Authors: Luxene Belfleur (UMET), Dra. Oliva M. Primera-Pedrozo (UMET)

Abstract

The high demand in the last decades for noninvasive methods to investigate complex biological systems has seen Raman microscopy emerged as important tool to study and to detect small molecules and biomacromolecules in cells. This technique has enabled the development of signatures for biological macromolecules, like DNA and proteins, in living systems. We recently described a new family of colloidal particles (termed, Supramolecular Hacky Sacks or SHS), which are made via a hierarchical self- assembly from 8-aryl-2'-deoxyguanosine (8ArG) derivatives, via supramolecular G-quadruplexes (SGQs). We have shown that these SHS can encapsulate biomedically useful molecules like anticancer drugs and genes, which in turn can be delivered to cells and mice. Because of their potential for biomedical applications, it is imperative to elucidate how the supramolecular structure of the SHS changes as function of the environment. While we have characterized these systems extensively using a number of techniques (NMR, SEM, DLS, DSC), it is important to develop a method that could be applied equally effectively to in vitro and in vivo experiments. Raman microspectroscopy meets these criteria, and in this presentation we will show the initial results on the characterization of the SHS and its constituents with this technique. Principal component analysis (PCA) of the spectroscopic data enables the distinction of different species like 8ArG, SGQs and SHS in the solid state. Ongoing studies in solution also look promising and we will present our progress along those lines, and will correlate them with characterization using other techniques such as NMR spectroscopy. Finally, we will show our progress in the development of 8ArG derivatives labeled with groups that provide higher Raman signals ("bio- orthogonal Raman tags" like alkynyl and deuterated methyl groups) in anticipation of future studies in cells.

345

Chemistry Presenter: Betancourt, Luis

Mentor: Cabrera, Carlos

Title: Fine tailoring of Au NP using RoDSE electrodeposition for EtOH electrooxidation

Authors: Luis Eduardo Betancourt De León (University of Puerto RIco), Ángel Ortiz (University of Puerto Rico), Carlos R. Cabrera (University of Puerto Rico)

Abstract

The focus of this investigation is to synthesize a very efficient catalyst for ethanol oxidation in alkaline media with minimal metal loading using a novel electrodeposition technique called Rotating Disk Slurry Electrodeposition (RoDSE). The RoDSE method to obtain highly dispersed Au nanoparticles does not require the use of a reducing agent or surfactant to deposit metal nanoparticles on a carbonaceous support and the noble-metal loading can be tuned by the addition of metal precursor volume. This technique was employed to obtain Au nanoparticles dispersed on a highly conductive carbonaceous support for ethanol electro-oxidation in alkaline media. This study focuses on electrodepositing Au NP on Vulcan XC-72R using different electrolyte media: H2SO4, KCl and KOH. The media used for electrodeposition determined the physical and electrochemical properties of our catalyst, showing a higher activity using alkaline pH as confirmed by cyclic voltammetry and chronoamperometry techniques. The amount of electrodeposited Au on the support was corroborated by ICP-AES. Particle size and specific Au crystal facets were determined by X-Ray Diffraction. TEM showed differences in terms of agglomeration and particle size as a function of electrolyte media. Surface area analysis of the Au NP was performed using the associated cathodic stripping of the Au-OH species.

346

Chemistry Presenter: Carmona-Negron, Jose A.

Mentor: Melendez, Enrique

Title: Crystallographic Studies of Ferrocene-Estrogen Derivatives Complexed with Human Serum Albumin and Estrogen Receptor alpha as Potential Drug Delivery Targets

Authors: José A. Carmona-negrón (University of Puerto Rico, Department of Chemistry, Mayagüez, PR), Wiliam J. Bauer (Hauptman-Woodward Medical Research Institute, Buffalo, NY), Edward E. Snell (Hauptman-Woodward Medical Research Institute, Buffalo, NY), Belinda Pastrana-rios (University of Puerto Rico, Department of Chemistry, Mayagüez, PR), Arnold L. Rheingold (University of California-San Diego, Chemistry and Biochemistry Department, La Jolla, CA), Enrique Meléndez (University of Puerto Rico, Department of Chemistry, Mayagüez, PR)

Abstract

Unlike common drugs that consist of entirely organic groups, incorporation of metals in organic frames provides a new range of not only structure and bonding properties but also reactivity. A new chapter in bioinorganic chemistry was open after cisplatin antineoplastic activity was discovered and introduced as a chemotherapeutic agent 30 years ago. However, secondary side effects caused by a lack of selectivity between healthy and cancer tissues limited the cisplatin drug application. Recently, ferrocene has been introduced for biological applications due its antineoplastic properties on Erlich ascite tumor. In order to develop a new class of metal-based therapeutic drugs with high selective index for hormone dependent breast cancer, a series of estrogen hormones have been functionalized with ferrocenes as pendent groups. These ferrocene complexes will be used to target estrogen dependent breast cancer (ER+), which account more than the 50% percent among the different breast cancers. The synthesized ferrocene-estrogen complex derivatives showed similar micromolar antiproliferative activity on hormone dependent MCF-7 breast cancer cell lines comparable to conventional therapeutic drugs activity such as tamoxifen and cisplatin. Computational studies of the interaction of the ferrocene complex with estrogen receptor protein demonstrated docking interactions of these ferrocene complexes in the ligand binding pocket of the estrogen receptor alpha (ER?). In this work we will present our ongoing efforts to elucidate and validate the effectiveness of the hormone moiety part of the ferrocene complex that is serving as a vector to target hormone-dependent breast cancer as a specific physiological target. Two main proteins were used as models: Human Serum Albumin (HSA), a protein carrier in blood serum plasma, and estrogen receptor alpha (ER?), a nuclear protein. Elucidation of specific drug-receptor interactions will contribute to our understanding of drug delivery and inhibition and will allow the prediction of future novel drug actions.

347

Chemistry Presenter: Corchado García, Juan

Mentor: Cabrera, Carlos

Title: Synthesis and Characterization of TiO2 supported Pt Nanoparticles via Photodeposition: Probing the Mechanism with In-Situ FTIR Spectroscopy

Authors: Juan Corchado García (Universidad de Puerto Rico Río Piedras), Nicolás Alonso-vante (Université de Poitiers), Cláudia Morais (Université de Poitiers), Carlos R. Cabrera (Universidad de Puerto Rico Río Piedras)

Abstract

Direct Ethanol Alcohol Fuel Cells are of great interest due to their theoretically high voltage output and the high amount of electrons transferred in the ethanol oxidation reaction (EOR). However, these two parameters can only be fully exploited if the oxidation of ethanol proceeds to completion; a notoriously difficult endeavor. In this work we synthesize TiO2 supported Pt nanoparticles in order to increase the efficiency of the EOR. First, Carbon/TiO2 nanocomposites were created by mixing Vulcan Carbon in isopropanol and titanium isopropoxide (TIP). The TIP was hydrolyzed with water, yielding the TiO2/C support. Platinum was deposited on the support by illuminating the samples with UV light in the presence of H2PtCl6. The ration of TiO2: C was varied from 20%, 50% and 80% but the amount of platinum was always 20% by total catalyst weight. The synthesized catalysts were analyzed by Cyclic Voltammetry and Linear Sweep Voltammetry where the current was found to double in the synthesized catalysts when compared to a Pt/C standard. In order to determine the reason for the increase in current, in-situ FT-IR studies were carried out at different potentials. It was found that the ratios of the bands associated to carbonate and acetate differed between the synthesized catalysts and the Pt/C standard. The carbonate bands were more pronounced in the synthesized catalysts than in the Pt/C control. This allows us to conclude that the Pt-TiO2 interactions favor the C-C bond cleavage and, thus, the full oxidation of ethanol. We propose that the charge transfer from TiO2 to Pt in the catalysts allows a nucleophilic attack to the electrophilic carbon in ethanol. This initial Pt-C adsorption has been found to favor full oxidation, as opposed to an initial Pt-O adsorption which favor acetate formation.

348

Chemistry Presenter: Estrella Martínez, Bárbara D

Mentor: Alamo Nole, Luis

Title: Absorption of Cd-based and Zn-based Quantum Dots by Ocimum Basilicum Seeds

Authors: Bárbara D Estrella Martínez (Pontifical Catholic University of Puerto Rico), Luis Alamo Nole (Pontifical Catholic University of Puerto Rico)

Abstract

Quantum Dots (QDs) are nano-structured semiconductors with size between 1 and 10 nanometers. QDs have been studied because their optical properties can be used for different applications such as the production of diodes and lasers. The most important property of QDs is their ability to absorb light and emit the energy as photons, a phenomenon known as fluorescence. The synthesis and commercialization of QDs have augmented in last years, which increase the probability to reach water bodies due to an inappropriate disposal. The normal growth of plants can be inhibited by the metal presence on the soil. The small size of the QDs can promote the absorption of high concentrations of these nanomaterials. High metal concentrations can be toxic and affect the growth of plants. In this study, Ocimum basilicum seeds were exposed to Cd-based and Zn-based QDs at different concentrations to evaluate the effect on the germination rates. For comparison purposes the seeds were also exposed to Cd and Zn ion solutions.

Chemistry Presenter: Garcia, Maria Del Mar

Mentor: Guadalupe, Ana

Title: Synthesis and Characterization of Polystyrene Inimers

Authors: María Del Mar García (University of Puerto Rico, Rio Piedras), Ana R. Guadalupe, Ph.d. (University of Puerto Rico, Rio Piedras)

Abstract

Polymer modified electrodes have shown advantages of chemical and physical stability. The modification of the electrodes gains relevance in the construction of biosensors because of the 349

structure, morphology and composition given by the attached molecules or polymers. In this research, polymers were synthesized to play a role of the scaffold in the assembly of amyloid detection elements. Two types of polymers were synthesized through nitroxide-mediated living radical polymerization. The first type, Polystyrene with carboxylic and 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) terminal groups was synthesized in DMF at 135°C. The second type Poly(Styrene-co-N-acryloxysuccinimide) 75:25 with carboxylic and TEMPO terminal groups were synthesized in THF at 85 °C. Polymers were synthesized in a reflux system or using a Schlenk line. The polymers were characterized by FTIR-ATR (diamond). Their molecular weight was determined by HPLC-light scattering. FTIR results confirmed the polymerization with the disappearance of the vinyl C=C stretch at 1631 cm-1, showing the C-H stretching bands of styrene from 3080 to 3030 cm-1, the TEMPO C-H stretching at 2923 and 2849 cm-1 and the succinimide group C=O stretching at 1779 and 1809 cm-1. The homopolymer M.W. was 28582 g/mol; the copolymer M.W. was 10799 g/mol both synthesized in a Schlenk system. The copolymer synthesized under reflux yielded 34.2 %. The copolymer synthesized in the Schlenk flask yielded 57%. The improvement in the yield is probably triggered by the complete absence of oxygen in the polymerization.

Chemistry Presenter: Gaur, Kavita

Mentor: Tinoco, Arthur

Title: Determination of Ti(IV)metallome in cellular environment

Authors: Kavita Gaur (University of Puerto Rico, Rio Piedras), Arthur Tinoco (University of Puerto Rico, Rio Piedras)

Abstract

There are a number of studies where titanium is used for the development of potential anticancer metal complexes. For this reason, during the last few decades, titanium metallomics has become an important and challenging field to understand its role in the organisms. Generally, titanium is found in a bound state in the blood to the Fe(III) transport protein transferrin. However, the Ti(IV) metallome in cells is not well-characterized. It is expected that the binding of Ti(IV) to biomolecules will depend on both the formulation of the metal and on the cellular environment, which varies in diseased and healthy cells. For instance, in healthy cells at physiological pH, Ti(IV) does not interact with DNA to inhibit replication and transcription, whereas in cancer cells there are a number of evidence to show a significant interaction of Ti(IV) with DNA, specifically with electron rich phosphate groups. The hypothesis is based on the study of the interaction of Ti(IV) with biomolecules, which is essential to the design of Ti(IV)-containing anticancer drugs. The possible interactions of Ti(IV) with cellular components which might be affected by the variability in cellular conditions are vaguely understood. In order to identify these interactions, 350

we are using the immobilized metal-affinity chromatography technique which operates principally through bio-specific interactions of the immobilized Ti(IV) with different amino acids, peptides, proteins, and nucleic acids. Such biomolecules have a capability of binding to the metals due to the presence of electron rich atoms on certain moieties. This binding ability of the biomolecules to the essential, non- essential or toxic metals plays an imperative physiological role in both, healthy and diseased cells. However, the interactions of above-mentioned biomolecules with Ti(IV) in the cellular environment are poorly understood. In this study, we will try to understand these interactions in more details. The outcome of this study will contribute to a better designing of Ti(IV) anticancer drugs. I have investigated these interactions on some proteins. My preliminary data shows that transferrin binds ~68% whereas albumin does not show a significant binding, however when these two proteins were taken in mixtures having different proportions [1:1, 1:10 (transferrin-to-albumin)], albumin binding in 1:10 proportion was comparatively higher than expected. I also analyzed fetal bovine serum (FBS) and found higher binding of transferrin than albumin. The data was analyzed by UV-Vis, SDS-PAGE, and MALDI-MS.

Chemistry Presenter: Gonzalez, Naqueira

Mentor: Gonzalez, Angela

Title: Growth and Survival rate of tropical oyster Crassostrea rhizophorae in presence of Cerium oxide nanoparticles

Authors: Naqueira Gonzalez Colon (Interamerican University San German)

Abstract

Nanotechnology is an important field of modern research dealing with design, synthesis, and manipulation of particles and structures within 1 - 100 nm. By the year 2015, it was estimated the investment of more than 1 trillion dollars in products based on nanotechnology worldwide. The increase in applications of nanomaterials in consumer products and other areas as health care, food products, environmental health, mechanics, chemical industries, electronics and optics have created the need to understand their destiny, transport and behavior in aquatic ecosystems. During the last decade, CeO2 NP's have been widely use due to their chemical structure and physical properties. Some applications included catalysts for the oxidation of fossil fuels, petrochemicals, sunscreens, cosmetics and coatings. CeO2NP's are insoluble in water, therefore they may stay longer in the media. This prevalence may represent a problem for the wide selection of marine organisms and ecosystems. In this study, we evaluated the growth and survival rate of the tropical oyster Crassostrea rhizophorae in presence of two different concentrations of CeO2 NP's for a period of 8 weeks. Results showed that the presence of CeO2 NP's did not inhibit the growth of oysters, however, survival of the oysters, grown with large concentrations of CeO2 NP's, was adversely affected. 351

Chemistry Presenter: Laboy Lopez, Simara

Mentor: Nicolau, Eduardo

Title: Evaluation of Synthesized Nanohydroxyapatite-Nanocellulose Composites as Biocompatible Scaffolds for Applications in Bone Tissue Engineering

Authors: Simara Laboy Lopez (University of Puerto Rico Rio Piedras Campus), Claudia S. Herdocia Lluberes (University of Puerto Rico Rio Piedras Campus), Jose A. Gonzalez Feliciano (University of Puerto Rico Rio Piedras Campus), Eduardo Nicolau (University of Puerto Rico Rio Piedras Campus)

Abstract

The growth and advances of new technologies have permitted humankind to expand the limits to where we have been able to travel. Space is not a frontier anymore and our position in space is something biological evolution has yet to perfect. In the meantime, scientists can work in order to alleviate many of the effects space travel has on our bodies. One of the effects of being out of our planet is that without gravity, the body has less load to bear. Our skeletons are what supports our structure overall and it is used to bear the amount of weight each individual carries on their body. When there is no gravity or is less gravity, the mass of the body remains equal, however, the weight applied to the skeleton, the bones, is different; is less. With this phenomenon the bones start losing its density and with it can become prone to fracture or break.In this work we present the creation of a nanohydroxyapatite- nanocellulose composite to work as a scaffold that can be employed in several scenarios and individuals such as astronauts and patients with conditions such as osteoporosis, who need to regain some of the bone density loss by either space travel or medical condition. These composites were evaluated with varying proportions of the polysaccharide network, cellulose nanocrystals (CNCs), and hydroxyapatite (HAp) synthesized via a simple sol-gel method.

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Chemistry Presenter: Lopez Cubero, Aleannette

Mentor: Tinoco, Arthur

Title: Affinity Study of a New Model of Coordination for Ti2-sTf: Insights of the Speciation the Metal in the Body

Authors: Aleannette Lopez Cubero (University of Puerto Rico, Río Piedras Campus), Talia M. Planas (University of Puerto Rico, Río Piedras Campus), Yamixa Delgado (University of Puerto Rico, Río Piedras Campus), Siul J. Muñoz Serrano (Escuela Especializada CIMATEC), Arthur D. Tinoco (University of Puerto Rico, Río Piedras Campus)

Abstract

Ti-containing implants have made an excellent contribution to the medical field. More and more our dependence on Ti for implant use will rise as the life expectancy rises. However, Ti is known to leach from these materials and it is not clear what the biological fate of this metal is. Recent studies have shown that serum transferrin (sTf) captures the leached metal. This protein is the main mammalian transporter of iron(III) into cells. It consists of two identical binding sites that bind Fe(III) with the help of a synergistic anion carbonate. A high resolution x-ray crystal structure from our laboratory for Ti(IV)- bound sTf demonstrates that Ti(IV) coordinates in a distinct fashion to the protein assisted by the synergistic anions carbonate and citrate, a property never before seen for this bioactive molecule. To understand the blood speciation of Ti(IV), particularly why Ti(IV) is specific to sTf and not serum albumin, the protein at highest concentration in blood and known to interact with different formulations of Ti(IV) in vitro, we studied the affinity of sTf to Ti(IV). Differential scanning calorimetry experiments helped to determine the validity of the binding model used to determine the affinity constant. In addition, a series of competition studies were performed with serum albumin. We discovered that Ti(IV) has very high affinity to sTf (log K = 23.5 and 25.2 for each binding site) but interestingly, serum albumin can inhibit this interaction on a physical level. This work sheds light on the importance of molecular crowding influencing metal biological speciation.

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Chemistry Presenter: Loza Rosas, Sergio A.

Mentor: Tinoco, Arthur

Title: Evaluating the potential of deferasirox, a commercial chemical transferrin mimetic, in Ti(IV) anticancer drug design

Authors: Sergio A. Loza-rosas (University of Puerto Rico), Alexandra M. Vázquez (University of Puerto Rico), Kennett I. Rivero (University of Puerto Rico), Lenny M. Negrón (University of Puerto Rico), Timothy B. Parks (VA Caribbean Health System), Arthur D. Tinoco (University of Puerto Rico)

Abstract

Serum transferrin is responsible for distributing Fe(III) to cells throughout the body. It has been postulated as the hydrolysis stabilizer of compounds of Ti(IV), which are known to be highly unstable in aqueous solution, by effectively chelating the metal ion and transporting it to cells by means via the same endocytotic route as Fe(III). Although this mechanism suggests a promising new anticancer drug design based on the cellular delivery of cytotoxic Ti(IV), efforts to develop a drug sustained in transferrin does not generate results favoring the improvement of the cytotoxic activity of Ti(IV) on cancer cells. Instead, it is proposed to design compounds of Ti(IV) using mimetic transferrin ligands to facilitate not only the stabilization and deliver of Ti(IV), but also to ensure the reduction of intracellular levels of Fe(III), which is detrimental to cancer cells because of their high requirement for Fe(III). deferasirox, a molecule designed to reduce excess of Fe(III) levels in pharmacological uses has been proposed as a potential chemical transferrin mimetic ligand. It stabilizes Ti(IV) but because it has a stronger affinity for Fe(III), it would be able to exchange Ti(IV) for capture of Fe(III) intracellularly. This study focuses on the synthesis of Ti(IV)-deferasirox complexes, the characterization of their structures in solution and solid state, and the kinetic studies of deferasirox metal exchange between Ti(IV) and Fe(III). The in vitro evaluation of the cytotoxicity of Ti(IV)-deferasirox complexes against A549 (lung carcinoma) and MRC5 (lung epithelial cells healthy) cell lines suggest a high activity comparable to other Ti(IV) complexes currently in development and even more activity versus the metal-free ligand.

354

Chemistry Presenter: Mercado Velazquez, Jose J.

Mentor: Rodriguez Lopez, Margarita

Title: Molecular Adsorption Studies at Bead Type Polycrystalline Platinum Electrodes

Authors: Jose J. Mercado Velazquez (PCUPR Ponce Campus), Margarita Rodriguez Lopez (PCUPR Ponce Campus), Arnaldo Carrasquillo Jimenez (UPR Mayaguez Campus)

Abstract

Electrochemical reactivity is sensitive to compositional and structural changes in the electrode surface. However, it is necessary to use ultra clean glassware, ultra pure water and high-purity reagents in order to control the composition of the electrode interface. It is possible to induce the presence of well- ordered Pt (111) facets on platinum bead type electrodes by gently heating the metal and cool ultra- pure water. This technique called Zone Refining spontaneously creates Pt (111) facets on the surface of the noble metal bead and also serves to purify the metal. In this work Cyclic Voltammetry (CV) is used, to correlate Current (i) vs Potential (V) curves that served as a fingerprint of the electrode surface composition and structure. CV allow us to corroborate the presence of small Pt(111) well ordered- domains at Pt bead type electrodes prepared in this project. Organic molecules as Catechol or Hydroquinone have been previously reported in our laboratory as domain selective probes. These molecules reveal a signal associated to reductive desorption that only occurs at well-ordered Pt (111) facets. We can use these domain selective molecules or probes to confirm the presence well-ordered Pt (111) facets at our bead type electrodes. This association was established when well-ordered Pt (111) facets were disordered electrochemically. If the facets are disordered, quinone-reductive desorption process associated to the well-ordered Pt (111) facets disappears. We can assume that this protocol detection can help to study others quinoidal molecules of biological interest to elucidate if they exhibit the same electrochemical behavior. Finally, we can use domain selective reactivity to induce molecularly-directed deposition of copper in at platinum surface electrodes. In these experiments we have found, macroscopic evidence, that copper is deposited preferentially to some areas of the platinum surface.

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Chemistry Presenter: Morales Guzmán, Christian

Mentor: Carballeira, Nestor

Title: Conjugation inhibitory activity of newly-synthesized alkynoic fatty acids

Authors: Christian Morales Guzmán (Department of Chemistry, University of Puerto Rico, Río Piedras Campus, ), Yaritza Rivera Torres (Interamerican University of Puerto Rico, Metropolitan Campus,), Joseph Mooney (Interamerican University of Puerto Rico, Metropolitan Campus), David J. Sanabria-Ríos (Interamerican University of Puerto Rico, Metropolitan Campus), Fernando De La Cruz (Molecular Biology Department, Universidad de Cantabria, Santander, Spain), Néstor M. Carballeira (Department of Chemistry, University of Puerto Rico, Río Piedras Campus)

Abstract

Antimicrobial agents have been used for the last decades in the treatment of infectious diseases. These drugs have been used for so long that these infectious organisms have adapted; for this reason these drugs have become less effective.(1) To prevent the development of resistance against antimicrobial agents the inhibition of bacterial conjugation is key. The bacteriological properties of acetylenic fatty acids have been widely studied, but their potential for the inhibition of bacterial conjugation processes aren't well known. Recently, Sanabria-Ríos and collaborators determined that the acetylenic moiety and carboxylic functionality in the 2-hexadecynoic acid are essential for an efficient conjugation inhibition (COIN) of the plasmid R388 in Escherichia coli.(2) Sanabria's group performed in silico molecular docking studies and determined that a group of C16 alkynoic fatty acids with a triple bond at ?6, ?8, ?10, ?12 could provide increased COIN activity. Based on these computational results we performed the synthesis of these alkynoic fatty acids. The total synthesis, characterization and COIN assays results will be presented.

Acknowledgement: This project was supported by NIH-PR INBRE (Grant # 2P20GM103475-14).

References:

1. Holmes, R.K.; Jobling, M.G. Genetics: Exchange of Genetic Information. Baron's Medical Microbiology ; (4th ed.). University of Texas Medical Branch, 1996.

2. Getino, M.; Sanabria, D.; Fernández, R.; Campos-Gómez, J.; Sánchez, J.; Fernández A, Carballeira, N.M.; de la Cruz, F., mBio 2015, 6, 1-8.

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Chemistry Presenter: Morales-Navas, Camila

Mentor: Cabrera, Carlos

Title: Exfoliated WSe2 for Solar Dye Sensitized Cells

Authors: Camila Morales Navas (UPR-Rio Piedras)

Abstract

Humanity needs many resources in order to satisfy its modern lifestyle. Large sums of Money and effort is being invested in search for alternative energy sources as a result from our current fossil fuel dependence. Hence other energy alternatives have been employed such as solar energy, which can take advantage of the sun's radiation and convert it to electrical energy. Solar cells have been designed for this energy transformation and choosing the right materials is essential to decrease its cost. Tungsten diselende (WSe2) is a semiconductor, and with titanium dioxide (TiO2), can be utilized as a photo harvester. An aggressive chemical treatment has been performed to modify the WSe2 crystal structure, from stacked array to a convenient separate layered array. This project focuses on monolayered WSe2 synthesis, specifically in the intercalation time variable. The synthesis has been made in a dry box, using lithium ions as an intercalate agent and deionized water as exfoliating agent. To characterize the material crystal array X-ray diffraction and Raman spectroscopy has been performed. The XRD results show a successful intercalation- exfoliation procedure, with a peak shifting in the pattern. Raman spectroscopy also gives a structural evidence of the layered material. Incident photon to current efficiency (IPCE) also has been performed, showing a good insight of photo-harvesting material behavior.

Chemistry Presenter: Prieto, Luis

Mentor: Rivera, Jose

Title: Synthesis and Development of Hydrogen Peroxide-Responsive Supramolecular G- Quadruplexes

Authors: Luis A. Prieto Costas (UPR-RIO PIEDRAS), Yanira Rodríguez (UPR-RIO PIEDRAS), Adlin V. García (UPR-RIO PIEDRAS), Jose M. Rivera* (UPR-RIO PIEDRAS) 357

Abstract

Reactive oxygen species (ROS) like hydrogen peroxide (H2O2) are small molecules that play a role in intracellular signaling as well as in cellular damage. This duality sparks the interest of researchers to design ROS-probes with the goal of understanding the role of H2O2 in normal and pathological conditions of the cellular environment. Even though H2O2-sensing systems have been studied, there are few examples of H2O2-responsive materials that are capable of drug delivery at biologically relevant concentrations of H2O2 (50-100?M). Boronic acid derivatives such as aryl boronates are used as selective H2O2 probes that have a change in fluorescence after the H2O2-mediated oxidation reaction. Recently we reported that colloidal particles made by pH/thermo-responsive supramolecular G- quadruplexes (SGQs) were suitable for the delivery of therapeutic agents. Addition of an aryl boronic ester to 8-aryl-2'-deoxyguanosine (8ArG) by an aldol condensation should result in a H2O2-responsive SGQ after self-assembly. Herein, we will show the synthesis and NMR characterization of six boronic ester model compounds, obtained with reasonable yields via aldol condensation of acetophenone and the corresponding aldehydes. We will also show the results of fluorescence spectroscopy studies, which will allow us to select the most appropriate aldehydes to be used for further development. Finally, we will discuss the results of molecular modeling studies to predict how the changes resulting from oxidation by hydrogen peroxide are likely to affect the structure of the target SGQs. We expect that the resulting H2O2-responsive SGQs will expand the repertoire of such particles, thus opening the door to new sensing and therapeutic applications.

Chemistry Presenter: Rivera González, Uriel

Mentor: Guadalupe, Ana

Title: Synthesis and Characterization of N-(ferrocenylmethyl)-5-amine-1,10-phenanthroline for the electrochemical detection of Fe(II)

Authors: Uriel Rivera González (Department of Chemistry, University of Puerto Rico, Río Piedras Campus), Stephen E. Uriarte Rodríguez (Department of Biology, University of Puerto Rico, Río Piedras Campus), Ana R. Guadalupe Quiñones (Department of Chemistry, University of Puerto Rico, Río Piedras Campus)

Abstract

Disruption of the homeostasis of metal ions like Fe(II), Fe(III), Cu(II), Zn(II), that are known to be essential for normal biological functions, is identified as an important factor in the development of various neurological conditions. To fully understand the role of these metals ions in diseases like Alzheimer, Parkinson, Prion-related, and Friedreich Ataxia, there is the need for measuring devices that can 358

interrogate them in biological specimens. Our principal goal is to develop an electrochemical device capable of detecting iron (II) in biological samples under physiological conditions. Our strategy consists in the modification of an electrode surface with a molecular recognition entity to electrochemically detect this analyte.

For this purpose, 1,10-phenanthrolin-5-amine was reacted with ferrocenemonocarboxaldehyde, to produce an imine, followed by a reduction to the final product. Also, the complex with the ferrous ion was synthesized and precipitated with hexafluorophosphate anion. The products were characterized by 1H-Nuclear Magnetic Resonance, 13C-Nuclear Magnetic Resonance, Fourier Transform- Infrared, and Ultraviolet-visible. The formation constant for the complex was calculated using the Continuous Variation Method, which resulted in 1014.78. Also, the new ligand was exposed to other cations and did not show any colorimetric change. For the electrochemical characterization, Cyclic Voltammetry, Square Wave Voltammetry, and Chronocoulometry were employed. It resulted in two redox processes for the conjugate, one for the ferrocene at 458 mV vs. Ag/AgCl (3 M NaCl) and other for the amine at higher potential. Also, a third redox event was observed for the formation of the complex in 1,020 mV vs. Ag/AgCl (3 M NaCl). Inclusive, exposure to iron, resulted in a positive movement of the oxidation potential of the ferrocene. Interesting features were noticed in the electrochemical characterization where the current density for the redox processes decreases with the continuous cycling which corresponds to the oxidation of the conjugate's amine.

The experimental results in this presentation consist in the first stage of the development of this sensor which is the synthesis and the characterization of the recognition molecule, Ferrocene-Ligand conjugate.

Chemistry Presenter: Rivera Sanchez, Maria Del C.

Mentor: Rivera, José M.

Title: Tuning the performance of 8-aryl-2'-deoxyguanosine derivatives as supramolecular ligand prototypes

Authors: María Del C. Rivera-sánchez (UPR - Rio Piedras and Molecular Sciences Research Center), José M. Rivera (UPR - Rio Piedras and Molecular Sciences Research Center)

Abstract

Beyond the use of small molecules, development of systems that can target certain biomacromolecules becomes very challenging and the subject of many recent strategies on the construction of novel drugs and drug delivery systems. The strategy of using supramolecular ligands has the potential to become a versatile and effective tool in drug development. Our strategy for the recognition of biomacromolecules 359

is to construct supramolecular G-quadruplexes (SGQ) formed by the self-assembly of 8-aryl-2'- deoxyguanosine (8ArG) derivatives. G-quadruplex DNA (QDNA) structures were choose as our first target since they have an exposed planar surface and variable topologies based on their loops organization. We also aimed to validate QDNAs as feasible targets for pharmacological intervention (e.g., anticancer treatments) but since there is a need to develop ligands having high affinity and selectivity, our strategy using SGQs as supramolecular ligands has a lot of potential.

We will present the synthesis and characterization of a family of 8ArG derivatives that was accomplished with moderate yields. Self-assembly studies based on 1D/2D NMR, DLS and DSC experiments suggest that only those compounds bearing an 8-metaacetylpahenyl ring can form discrete hexadecameric SGQs. Evaluation of their affinity for telomeric and oncogenic QDNA structures based on FRET melting assays reveal that structural variations on 8ArGs have the potential to modulate its affinity and selectivity towards specific QDNA structures. Also, only those derivatives that form discrete hexadecameric SGQs in solution are the ones with the highest stabilization capacity. The implications of our findings go beyond targeting QDNA structures since the structure of 8ArG derivatives can in principle be tuned to modulate the properties of their behavior as supramolecular ligands when self- assembled into SGQs.

Chemistry Presenter: Rojas Pérez, Arnulfo

Mentor: Diaz-Vazquez, Liz

Title: Caribbean macro-alga Osmundaria obtusiloba as potential reducer for biosynthesis of metal nanoparticles

Authors: Arnulfo Rojas Pérez (University of Puerto Rico - Rio Piedras campus), Lineth Adorno (University of Puerto Rico - Rio Piedras campus), María Del Mar Cordero (University of Puerto Rico - Rio Piedras campus), Liz M Díaz Vázquez (University of Puerto Rico - Rio Piedras campus)

Abstract

Marine macro-algae have chemical compounds with greater potential. It has been proposed that terrestrial plant extracts and fungi can work efficiently for the synthesis of metallic nanoparticles (NPs). In this research, an innovative biological method was elaborated through the use of Caribbean macroalgae Osmundaria obtusiloba. Algae extracts were used to synthesize gold (Au), silver (Ag), palladium (Pd), platinum (Pt) and nickel (Ni) NPs. Pd, Pt, Ag and Au NPs were biosynthesized at room temperature using Caribbean macro-algae extract as a reducing agent which was added to a 1.0 mM metallic solution. Ni NPs were biosynthesized at 50°C and added to a 0.100M of NiCl2-6H2O. UV-Visible 360

spectroscopy was used to monitor the formation of metallic NPs as a function of reaction time. Results revealed that the bio reduction of metal ions in aqueous solution absorbed in the predicted wavelength region and consequent solution color changes were observed. The NPs characterization was determined using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectroscopy. These analyses determined the average particle size and morphology of NPs as well as the identification of biomolecules for capping and efficient stabilization of metallic nanoparticles, respectively. Our work is concentrated in contributing to NPs synthesis via green chemistry methods to improve the use of renewable energy

Chemistry Presenter: Sanchez Alvarez, Annelis O

Mentor: Cabrera, Carlos

Title: Graphene Quantum Dots Biosensor for Early Cancer Detection

Authors: Annelis O. Sanchez (UPR - Rio Piedras)

Abstract

Graphene Quantum dots (GQDs) are of great scientific interest in many research areas such as electronics, imaging, and medicine. GQDs is a semiconductor material in the range of 2-10 nm in diameter. Its small size allows for its quantum-confinement property, which permits their fluorescence behavior upon excitation.1 However, their complex synthesis, and the materials used to achieve the desired nanocrystals have been an obstacle to further their application and commercialization. Cd/Se or some other metal combination of periodic groups II/VI or III/V are commonly used to synthesize GQDs.2 Although coating methods have been developed to avoid the metal exposure to the body, this metal component has raised a polemic discussion regarding the use of GQDs in medicine due to its possible toxicity if exposed to the body.2 Recently, Tang et al. published a sugar based GQDs synthesis using microwaves (MW).3 This is a huge advantage in terms of green chemistry, fast synthesis, and economic starting material. Because of their properties, GQDs have been modified to be used as cargo molecules for drug delivery, fluorescent probes, and biosensors among others.

It is known that most cancer cells exhibit an excess of reverse transcriptase; a RNA protein that recognizes a particular oligonucleotide sequence in the telomere, and lengthen it by using its intrinsic RNA. 4 With each cell division, cells lose about 50-200 base pairs of its telomere, and when it gets significantly shortened, the cell enters a state of growth arrest called senscence.4 Most cancer cells have short telomere and an overexpression of telomerase, preventing the cell from entering cell arrest and inducing proliferation. Normal somatic cells do not have the telomerase protein activated and once their 361

telomere gets shortened, they enter cell arrest.4 The herein project aims to use an economic GQDs synthesis to develop an efficient cancer biosensor optimized on cost, sensitivity, and selectivity. GQDs have been previously used coupled to biomolecules in order to obtain a signal and achieve a biosensor,5,6 but no biosensor has been done using a telomerase approach. The GQD biosensor will incorporate a chain of oligonucleotides that upon telomerase recognition, will enlarge the chain and create an electric and/or spectroscopic signal to be used as a sensor.

Chemistry Presenter: Vargas Santiago, Jennifer

Mentor: Lopez Garriga, Juan

Title: Hydrogen sulfide (H2S) measurement by Hemoglobin I from Lucina pectinata encapsulated in sol-gel using spectrophotometry

Authors: Jennifer Vargas Santiago (UPR-Mayaguez), Juan Lopez Garriga (UPR-Mayaguez)

Abstract

Due to numerous physiological effects and therapeutic implications of H2S, the scientific community has shown interest in developing a sensitive method for H2S detection within specific tissue and biological system. In this work we describe a protocol to measure gaseous and aqueous H2S using Hemoglobin I (HbI). This hemeprotein present in the clam Lucina pectinata possesses high affinity for H2S. The experiment consists of encapsulating HbI in tetramethylorthosilicate (TMOS) gel to evaluate the ability of the polymer to trap H2S in aqueous and/or gaseous state. The goal is to use it as a sensor by measuring the 407nm and 426nm transitions for the metHbI and HbI(FeIII)-H2S complexes, respectively. Here, we focus on determining the association and dissociation rate constants for the HbI(FeIII)-H2S complex upon the reaction of HbI with gaseous H2S using a simple kinetic model. The affinity towards the H2S was smaller than the corresponding value in solution as a consequence of hydrogen bond interactions between H2S and the TMOS structure. Therefore, these results show that the encapsulated HbI is a good prototype to trap H2S. Nevertheless, further improvements in the HbI immobilization system are necessary before future applications in biosensing. In future work, the association constant of HbI(FeIII)-H2S will be determine with the encapsulated HbI in TMOS but using H2S in solution instead of the gas.

362

Chemistry Presenter: Vega Avila, Ana L

Mentor: Perales-Perez, Oscar

Title: SYNTHESIS, CHARACTERIZATION AND BACTERICIDAL ASSESSMENT OF MgO-POLYMERIC FIBER NANOCOMPOSITES FOR WATER DISINFECTION

Authors: Ana Lucia Vega Avila (Universidad de Puerto Rico (Mayaguez))

Abstract

The increasing number of antimicrobial resistant infectious diseases has generated great interest in the development of new antimicrobial agents. Metal oxide nanoparticles are among these compounds.

Metal oxide nanoparticles such as magnesium oxide (MgO), zinc oxide (ZnO), calcium oxide (CaO), titanium dioxide (TiO2), aluminum oxide (Al2O3), etc. are among the nanoparticles with antimicrobial activity, these are stable under harsh process conditions and are considered harmless to human beings due to the lack of toxicity of the bulk material.

Among metal oxide nanoparticles, MgO have demonstrated bactericide effect against E-coli and salmonella, which are pathogen agents commonly found in aqueous environments. Also has exhibited bactericide effect against staphylococcus aureus and spores.

Despite its promising antibacterial properties, the recovery of MgO nanoparticles after the treatment in aqueous environments remains as a limiting factor for its practical applications. The immobilization of MgO nanoparticles in polymeric electrospun membranes is a feasible solution to this drawback.

In this work MgO nanoparticles were synthesized and incorporated into polyacrilonitrile (PAN) nanofibers via electrospinning, and were assessed as water disinfection material. The Bactericide activity of MgO nanoparticles and PAN-MgO membranes against E-Coli was assessed by plate spread method. MgO nanoparticles with average crystallite size of 8.6 nm completely inhibited E-Coli growing at concentrations of 2000 ppm. In the other hand PAN- 20%MgO (%wt) electrospun nanofibers completely inhibited E-Coli growing when 0.1g of the membranes were used in the treatment of 10 ml of medium containing E-Coli at concentration of 10^7 CFU/mL.

This results indicates that electrospun membranes are a suitable supports for MgO nanoparticles immobilization, which allows its practical use for water disinfectation.

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Engineering

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Engineering Presenter: Cabán Nevárez, Rebeca B.

Mentor: Perales-Perez, Oscar

Title: Processing and Characterization of Talc Nanoparticles for Biopolymer Nanocomposites

Authors: Rebeca B. Cabán Nevárez (University of Puerto Rico-Mayaguez), Oscar J. Perales Pérez (University of Puerto Rico-Mayaguez)

Abstract

Food packaging involves a great demand of non-degradable plastics. There is potential for biopolymers to substitute petroleum-derived plastics to help reduce environmental impacts. However, biopolymeric materials present several disadvantages, e.g. poor mechanical and barrier and thermal properties and strong water sensitivity. The use of nanoclay fillers in biopolymeric matrixes has the potential to minimize some of these shortcomings under a cost-efficient basis. Talc has potential as suitable filler for food packaging biopolymers due to its high aspect ratio and chemical inertness. Besides, the hydrophobic nature of talc would also decrease the water sensitivity in the resulting polymeric nanocomposite. In this regard, the dependence of talc hydrophobicity on particle size has not been studied systematically yet. Accordingly, the present research focuses on the systematic investigation of the effect of talc particle size on the corresponding hydrophobicity. For this purpose, micron-size talc samples were ground using a high-intensity planetary ball mill at different milling times as an attempt to reduce particle size. XRD results confirmed the decrease in the powder crystallinity (i.e. crystallite size) by prolonging the milling time; the crystallite size varied from starting 10um sample down to the nanoscale when the milling time was prolonged up to 5 hours. Fourier Transform – Infrared spectroscopy (FTIR) analyses revealed the talc characteristic bands centered on 3677 cm-1and 669 cm-1 for the O-H bonds and 1018 cm-1 for the Si-O bonds. Broadening of the peaks was also observed in the FTIR spectra, which coincides with XRD results that particle size reduction was achieved. The influence of the milling time on the BET Specific Surface Area of the ground powders and the corresponding results from contact angle measurements will be presented and discussed.

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Engineering Presenter: Delgado Castro, Miguel A.

Mentor: Romero, Edwar

Title: Raspberry PI programming for Vibration Trendline Monitoring

Authors: Miguel A. Delgado Castro (Turabo University)

Abstract

In vibration monitoring it is common to observe the vibration changes. These changes show the condition of the equipment and help in the maintenance of it. A common technique used to measure and learn about the equipment status is the Vibration trend line analysis in which the behavior of the system vibrations is observed and compare with an initial test result. This research aims to perform this analysis using a Raspberry PI microprocessor. The use of a raspberry pi for this testing will reduce the cost of vibration monitoring and may result in an increase of possibilities within the vibration analysis and other tools due to the Raspberry PI connectivity.

Engineering Presenter: Linares Blasini, Maximino

Mentor: Méndez-Piñero, Mayra

Title: Site Selection in Renewable Energy: A Look within OTEC

Authors: Maximino Linares Blasini

Abstract

The use of optimization models for solving the location problem have been implemented in a different range of industries and research fields. Renewable energy is resource dependent, these resources are not available everywhere and all the time. Making site selection for a renewable energy systems a key topic when considering the development of any kind of renewable energy plant. The trend of using site selection optimization models in renewable energy is growing. Literature in the application of optimization models for site selection can be found in almost all types of renewable energy except for ocean thermal energy converter (OTEC) systems. The area of OTEC site selection is still very raw the only factor taken into consideration is the presence of the thermal gradient. The current literature in the 367

OTEC energy field has yet to investigate a detailed site selection process, which leads my investigation of the development of site selection optimization model for the OTEC energy field. A heuristic approach will be developed to solve this site selection problem considering the following parameters: thermal gradient, economics, grid distance, coastline distance, plant size and population.

Engineering Presenter: Narvaez Bandera, Isis Y.

Mentor: Torres-Garcia, Wandaliz

Title: Data-driven approach to extract molecular patterns in breast cancer using transcriptomic and clinical data

Authors: Isis Yanina Narvaez Bandera (University of Puerto Rico), Wandaliz Torres-garcía (University of Puerto Rico)

Abstract

Despite significant biotechnology growth in recent years, cancer mechanisms are still not fully understood. Breast cancer is a disease of the genome and the most common cancer leading to death among Puerto Rican women. To improve diagnosis and treatment it is necessary to characterize molecular patterns that contribute to tumor progression. There is wealth of literature on biomarker detection through the study of gene expression using microarray assays that has yielded important discoveries. Nonetheless there is massive amount of data available from different molecular assays that require more complex and efficient data mining methodologies to extract insightful knowledge. Therefore, we proposed to integrate information from gene expression (i.e. microarray, RNA-sequence), immunohistochemistry assays and clinical patient features (i.e. menopause status) available for over 500 breast tumor tissue samples from patients under The Cancer Genome Atlas repository to discriminate among breast cancer subtypes (PAM50). Consequently, the main challenge of integration lies in the high data dimensionality and class imbalance.

To solve the high dimensionality problem we evaluated the performance of three-feature selection methods (Information Gain, ReliefF, Correlation-based (CFS)) aimed to distinguish between different subtypes. Before implementing these methods, we performed an initial filtering step by considering only cancer-related genes from Cosmic, Vogelstein and the Candidate Cancer Gene Database. This resulted in ~6000 genes from ~20,000 which were used for further feature extraction. The evaluation was performed by measuring accuracy and AUC through three well-known classification methods (Support Vector Machine, Random Forest and K-nearest Neighbor) in a cross validated manner. We observed that CFS was the best method overall yielding low error rates (~10%) and high AUC values (~90%). It extracted 79 and 76 vital genes from two expression platforms. Lastly, we integrated extracted genes 368

with clinical factors, although no significant improvements were observed through Multi-Dimensional Scaling.

To evaluate the biological significance of our findings we investigated the relevant features using the cBioPortal tool. The results were encouraging since extracted genes were altered in 98% of the samples for Basal and 95% for HER2. Genes such as FOXC1, ESR1 and FOXA1 have had a proven to have high impact in breast cancer. These findings validate the prediction efficacy of our model and allows us to explore even further other genes such as MIA, THSD4, and ANLN that had lesser amount of literature available. Further experiments are recommended to understand its causality effect in breast cancer. Future studies should consider optimizing feature selection and classifier parameters. Also integrating other types of genomic assays could reveal higher degree of interactions to better understand the mechanisms of breast cancer subtypes.

Engineering Presenter: Rivera-Goyco, Christian G.

Mentor: Cardona Martinez, Nelson

Title: Synthesis of Sulfonic Acid Based – CMK-3 Catalytic Materials for the Dehydration of Fructose to 5-(Hydroxymethyl)furfural in Polar Solvents

Authors: Christian Rivera-goyco (UPR-Mayaguez), Leida Vázquez-ramos (UPR-Mayaguez), Nelson Cardona-martínez (UPR-Mayaguez)

Abstract

The burning of fossil fuels has been associated with Climate Change. Biomass is the main renewable source that can substitute fossil fuels, but to achieve this some technical challenges must be overcome. One of them is the design of catalysts with good thermo solvent stability, and this is especially true for aqueous liquid phase processing as is the case of fructose dehydration reaction to 5-hydroxymethyl- furfural (HMF). In this work we report the production of HMF from fructose catalyzed with CMK-3 carbon materials with different sulfonic acid groups (aliphatic or aromatic) and the study of the effect of using different polar reaction medias on the activity and selectivity towards HMF. Characterization of the materials before reaction was performed using different polar reaction scanning electron microscope (SEM), nitrogen adsorption - desorption isotherms, X-Ray diffraction (XRD), and elemental analysis. Results to date indicate that the synthesized carbon materials have the desired ordered range of mesopores, textural properties and have been grafted with the desired sulfonic functional groups. All of the sulfonic acid functionalized materials shown good catalytic activity, and selectivity towards HMF production. Results to date suggest that there is a different in the activity and selectivity between the different sulfonic acid groups. Finally, the solvent used in the reaction have a strong effect in the activity 369

and selectivity in the dehydration of fructose to HMF, obtaining the best activities and selectivities when GVL and THF are being used as reaction medias, respectively.

Engineering Presenter: Salazar Aquino, Cesar M.

Mentor: Ramirez, Nazario

Title: Estimation of precipitable water using satellite data

Authors: Cesar M. Salazar Aquino (University of Puerto Rico Mayaguez Campus), Nazario D. Ramirez Beltran (University of Puerto Rico Mayaguez Campus), Joan M. Castro Sanchez (University of Puerto Rico Mayaguez Campus), Jorge E. Gonzalez (City College of New York)

Abstract

To understand, estimate and/or predict atmospheric variables has become an important scientific issue, based on multiple application on science and society. Satellite data provides a good quantity of information to do these analysis, usually for large geographical areas and, depending on the satellite, with a good spatial and temporal resolution. however the amount of missing values is high in some satellites observations, based on their coverage areas or clouds interference, and some products are not directly obtained but have to be derived from others variables. Working with those satellite dataset is not only useful but also is a complex process. It is not enough to download data, it has to be preprocessed, geolocated, and sometimes is necessary to apply data quality process and regression analysis to develop some specific products from it.

Precipitable water is an important product in many climatological investigation and can be obtained from satellite as the Moderate-Resolution Imaging Spectroradiometer (MODIS), an instrument mounted in a group of polar satellites: TERRA and AQUA. However, even when spatial resolution is high (1 km), temporal resolution is insufficient, since provides observations two times per day, and many of these observations do not cover the complete area of study, in this case Puerto Rico and Caribbean islands. There are geostationary satellites that provide information in a good time intervals and always over the same area, this is the case of The Geostationary Operational Environmental Satellite (GOES). GOES-13 is constantly over the area of study and offering observations every 15 minutes, however the spatial resolution decrease to 4 km. to optimize the quality of precipitable water from satellite became necessary to use GOES data to estimate MODIS product, taking advantage of the high temporal resolution and constant observations of GOES and the high spatial resolution of MODIS. 370

The objective of this study is to use regression techniques to estimate precipitable water based on MODIS data. Two models were developed: one based on MODIS AQUA and another on MODIS TERRA. Preliminary results has shown that using MODIS TERRA an R squared value of 0.217 and a RMSE of 0.397mm were obtained, and using MODIS AQUA an R squared value of 0.422 and a RMSE of 0.641 mm. were obtained.

Engineering Presenter: Soto Maldonado, Zachary M.

Mentor: Medina, Lourdes

Title: A Study of Complexity in Project-Based Learning for Ebgineering Undergraduate Education

Authors: Zachary Soto (UPRM), Lourdes Medina (UPRM), Melissa Rosado (UPRM)

Abstract

This research aims to measure complexity in engineering education, specifically in Project Based Learning (PBL). Literature shows there are research in managing complexity but there is not much effort spend on measuring and understanding complexity for engineering education in general in our area of interest, process automation.

For example by interviewing engineering professors with open-ended questions we want to know if complexity is considered for PBL in engineering education and if it should be assessed for projects. More specific when the requirements are the same, we want to understand if the complexity of the multiple solutions generated is significantly different? Or when students are assigned different project, the project definitions is significantly different?

With limited research to consider in this area, several metrics in the literature have been identified and will be studied in depth for the adaptation and creation of new metrics that would help measure design complexity in PBL specifically for projects of the course ININ 4057 (Process Automation) offered at UPRM. These metrics will show how we can assess design complexity in PBL when students have the same requirements. At the end with the result of the surveys and the process automation complexity metrics we will be able to identify, analyze and control complexity in PBL for engineering undergraduate education and promote a culture of complexity thinking.

371

Engineering Presenter: Valencia Romero, Ambrosio D.

Mentor: Lugo Ortiz, Jose

Title: Quantification of Symmetry, Parallelism, and Continuity as Continuous Design Variables for Three-Dimensional Product Representations

Authors: Ambrosio Valencia-romero (UPR-MAYAGUEZ), José E. Lugo (UPR-MAYAGUEZ)

Abstract

This work builds upon and introduces a new methodology to quantify the form of a three-dimensional (3D) product representation using the classical Gestalt principles as design variables in the product development process. Vastly discussed for two-dimensional (2D) representations, Gestalt principles explain how humans group elements in an image to devise them as a whole, and previous work has identified a strong relationship between quantified Gestalt levels and aesthetic subject preference. Although the use of 2D projections has proved to be significant to the study of subjects' judgments about real objects, depth and vergence cues characteristic of 3D representations are required for a better understanding of aesthetics perception. Herein, consistent expressions to quantify the Gestalt principles of symmetry, parallelism, and continuity for parametrized 3D representations in a definite scale are presented, and a generalized methodology applicable to any product form is discussed. It starts with the identification of important aesthetic forms of the product, next step is to identify which principles are more relevant to those forms, and finally the Gestalt principles for the 3D product representations are quantified. The expressions to quantify the three Gestalt principles in question are validated through an online survey in which subjects indicated in a Likert-scale how much they recognize symmetry, parallelism, or continuity from irregular shapes. Finally, random-effects ordered logit regression is used to determine if the expressions effectively describe the level of recognition of each Gestalt principle.

Engineering Presenter: Vargas Martinez, Juan C.

Mentor: Suarez, Oscar Marcelo

Title: Selective Dissolution of Al-Cu-Mg Alloys for Porous Metals Applications 372

Authors: Juan Carlos Vargas Martinez (University of Puerto Rico, Mayaguez Campus), Abel Urbán Rios (University of Puerto Rico, Mayaguez Campus), Oscar Marcelo Suárez (University of Puerto Rico, Mayaguez Campus)

Abstract

Nanoporous metals are innovative materials that can be formed by selective dissolution of a given alloy. In particular, such dissolution of Al-Cu-Mg alloys can turn a polished smooth surfaces into porous specimen, as less noble atoms are removed from the alloy. The present research attempts to produce an optimum pore size by varying different solidification parameters. The samples bore a ternary eutectic composition with about 8.5 at.% Mg. The Al-Cu-Mg alloy grains are refined by water-quenching. Then the microstructure was stabilized via annealing under different heat treating conditions under study. Optical microscopy showed that three phases were present in the treated alloys: ?-Al, ?-(Al2Cu), and S- Al2CuMg. The first solid phases enclosed the S-phase upon solidification. A 10% NaOH solution achieved the complete removal of aluminum to produce the sought porosity. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were conducted to corroborate those results.

373

Environmental Sciences

375

Environmental Science Presenter: Bernier, Yomarie

Mentor: Pérez-Jiménez, José R.

Title: Hexadecane-Degrading Bacteria: Inoculums for Efficient Soil Rhizoremediation

Authors: Yomarie Bernier-casillas (Universidad del Turabo), Kenya F. Álamo Rodríguez (Universidad del Turabo), José R. Pérez-jiménez (Universidad del Turabo)

Abstract

Rhizoremediation has been improved by efficient combination of plants and microbes to reduce harm of pollutants in nature. Bacterial contribution to alkane degradation has been documented for polluted and temperate sites. Alkanes, as hexadecane, reach the environment by anthropogenic activities and natural processes, including plant exudates. We hypothesized that if we stimulate microbes naturally selected in soil then plant development will be enhanced and remediation will proceed. Our objective is to evaluate which hexadecane-degrading bacteria (HDB) promote plant development. Soil samples were collected along Caño Martín Peña (San Juan, PR). HDB were isolated by aerobic cultivation on mineral media supplemented with hexadecane as sole carbon source and subjected to 16S rDNA sequencing. Isolates were tested in vitro for colonization factors. A selection of them was inoculated in soil microcosms, with Phaseolus vulgaris seeds, to evaluate their contribution to plant growth. All prospects were able to grow in hexadecane (1% v/v). Colonization factors revealed diverse capabilities among fifty- eight strains: phosphate solubilization (7%), production of indole acetic acid (3%), ammonia (17%), protease (34%), and siderophore (4%). Most of the factors were harbored in twenty strains, including members of Klebsiella and Pseudomonas. Plant microcosms have shown efficient plant growth, mostly by Klebsiella sp. HDB prevailed across Neotropical ecosystems, despite pollution level, are phylogenetically diverse, and harbors novel genetic variants. In the elucidation of colonization factors, the most specialized ones occur in a minimal fraction of the isolates. These hexadecane-degrading bacteria provide novel isolates to deal with pollution and disclose processes in nature.

376

Environmental Science Presenter: Castro Sanchez, Joan M.

Mentor: Ramirez, Nazario

Title: Rainfall Nowcasting Algorithm Based Hydro-Estimator Data and detecting warm raining clouds

Authors: Joan M. Castro Sanchez (1Department of Civil Engineering, University of Puerto Rico - Mayaguez), Nazario D. Ramirez-beltran (2Department of Industrial Engineering, University of Puerto Rico - Mayaguez), Robert J. Kuligowski (NOAA/NESDIS Center for Satellite Applications and Research (STAR), Camp Springs, MD)

Abstract

This work includes a summary of two research topics: a nowcasting algorithm and detecting warm raining clouds.

(1) A nowcasting algorithm based on satellite (Hydro-Estimator) data is introduced in this work. The Short Time Rainfall Prediction (STRaP) algorithm is a real time procedure for predicting the spatial and temporal distribution of rainfall rate for Puerto Rico. The most likely raining areas are predicted and then the expected intensity of rainfall rate in each rain pixel is forecasted. The Otsu's method based on discriminant analysis was adopted to identify contiguous rain pixels. A tracking algorithm is introduced in this work and maximizes persistent pixels and minimizes the size-difference of a single rainfall cell observed at two instant of times. The cloud motion vector is used to predict the most likely rainfall areas. The predicted rainfall areas are divided into smaller regions to best represent the spatial and temporal rainfall variability. An exponential regression model in time and spatial domain is developed for each region to predict the growth and decay of rainfall intensity. It is assumed that the potential predictors are the two previous observations of reflectivity located in a neighborhood region with center on a predicted pixel. An iterative forward selection algorithm is used to eliminate irrelevant pixels and determine the best predictors for each region; and finally, the intensity of rainfall rate is forecasted at pixel level. STRaP makes short forecasts every 15 minutes with lead time that varies from 15 to 90 minutes. Nine tropical storms that occurred in Puerto Rico during 2003-2013 were used to validate the proposed algorithm. The Eulerian and Lagrangian algorithms were compared with our algorithm and results show that the performances of Eulerian and Lagrangian algorithms were slightly better than our algorithm.

(2) It has been shown passive microwave techniques significantly underestimate warm rain, and most of the underestimations occur for clouds with low tops (

377

Environmental Science Presenter: Deliz Garcia, Carlos H

Mentor: Nieto Ramos, Santander

Title: Catalysis in Environmental Application: Carbon Monoxide Converter Emission by Osmium support in Titanium Oxide

Authors: Carlos H. Deliz Garcia (Turabo University)

Abstract

Carbon monoxides contribute to several environmental hazards to humans, including respiratory illness, global warming, and acid rain. Many transition metals such as cobalt, platinum and gold are used in heterogeneous catalysis to reduce pollution emissions.One significant drawback to these materials such as platinum and gold is their high cost. To address this concern, a search for lower cost, alternative materials has led to the study of transition metal catalysts. Osmium is proposed as a good candidate because it has been shown to be active for CO oxidation and is less expensive than gold and platinum. The Osmium electron configuration [Xe] 4f14 5d6 6s2 is similar to Platinum Electron configuration [Xe] 4f14 5d9 6s1.The high orbital d deficiency causes a stronger interaction with negatively charged molecules. 10 % of Osmium and Platinum were supported on TiO2 and prepared by solid by solid, sol- gel (SG) and incipient wetness impregnation (IWI) techniques. The catalysts have been characterized by surface area analysis, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and diffuse reflectance Fourier transforms infrared spectroscopy (DRIFTS). The characterization demonstrated that this metal oxide phase is more dominant on the sol-gel and solid by solid impregnation support than on wetness impregnation. The complete oxidation of CO to CO2 could also be observed below 100°C for the sol-gel and solid by solid impregnation.

378

Environmental Science Presenter: Díaz Mercado, Jayleen M.

Mentor: Perez-Jimenez, Jose R.

Title: Lignin Degrading Bacteria At Laguna Grande And Laguna Aguas Prietas' Water In Fajardo.

Authors: Jayleen M. Díaz-mercado (Universidad del Turabo), José R. Pérez-jiménez (Universidad del Turabo)

Abstract

Lignin is often the most difficult portion of plant biomass to degrade and plays an important role in the cell wall structure of plants as it serves as its support. It is also the most abundant natural aromatic polymer in the world. Lignin is a complex heteropolymer linked to cellulose, giving plants structural integrity. The deconstruction of lignin and its dissociation from cellulose presents a challenge for soil microbes and biofuels engineers alike. The purpose of this study is to find bacteria that degrade lignin at bioluminescent bay Laguna Grande and Laguna Aguas Prietas in Fajardo Puerto Rico. Water samples from both lagoons were obtained, which were added to culture media. Liquid culture medium were used: LS4D for measuring absorbance, medium culture with Remazol Brilliant Blue R indicating lignin degradation, and enriched medium with lignin as the only sole carbon source. Dilutions were made from the cultures and then cultivated in trypticase soy agar, isolating the bacterial colonies. Also, DNA extractions were done to identify bacteria by 16S rDNA sequencing. For eleven days absorbance was increasing for both lagoons enrichments, indicating that phenolic compounds concentrations were decreasing. Seven isolated bacteria were closely related to Staphylococcus sp. and Shewanella sp.. These bacteria constitute novel lignin-degrading bacteria.

379

Environmental Science Presenter: López González, Luis F.

Mentor: Marquez, Francisco

Title: Silicon Substrates for the Growth of Carbon Nanotubes, and its Application for the Development of Ionizing Radiation Sensors

Authors: Luis F. López (University of Turabo), Jenipher D. González (University of Turabo), José Ducongé (University of Turabo), María Cotto (University of Turabo), Carmen Morant (Universidad Autónoma De Madrid), Francisco Márquez (University of Turabo)

Abstract

Detection of ionizing radiation is crucial in different fields including energy, national security, biological and nuclear research, and other applications. In general, the systems for the detection of ionizing radiation usually have one or several of the following drawbacks: incapability to produce stable signals, expensive and complicated manufacturing processes, operation at low or very low temperatures, low sensitivity or even voluminous size, as is the case of Geiger counters. Single Walled Carbon Nanotubes (SWCNTs) have attracted much interest for the design of advanced nano-devices, due to its excellent mechanical, optical, thermal properties and electrical conductivity. Among the possible applications, these materials can be successfully used as efficient ionizing radiation sensors. For this purpose, the critical steps in the design and fabrication of devices are focused on the growth of SWCNTs into controlled architectures and onto appropriate substrates. In this research we report a method for the treatment of the silicon substrates with TiN and a mixture of Co and Mo salts as catalyst precursor for the synthesis of the carbon nanotubes. XPS and AFM results show an appropriate distribution of the catalyst precursors on the Si surface.

380

Environmental Science Presenter: Martinez, Neidibel

Mentor: Roberson, Loretta

Title: Impact of thermal stress on growth and photosynthesis in larvae and adult stages of Porites astreoides

Authors: Neidibel Martinez Gonzalez (UPR-RP), Loretta M. Roberson (UPR-RP)

Abstract

Coral reefs face a number of environmental changes, chief among them rising temperatures, with consequences that are not entirely understood. A rise in sea surface temperature can affect physiological processes in different ways during each development stage, leading to higher or lower growth rates, or decreased survivorship. Here we determine the impact of thermal stress on photosynthesis and growth in P. astreoides at different developmental stages. Photosynthetic efficiency (Fv/Fm) of adults and larvae were measured using a Diving PAM (Walz). Growth rates of adults were measured using the buoyant weight technique and larval growth rates (planar area) were measured using light microscopy and Image J-Fiji software. The preliminary data for both stages show high values of effective quantum yield (Fv/Fm) when exposed to a temperature of 30°C, which may suggest an ability to acclimate to higher temperatures. With an exposure time of five days however, there was a reduction in effective quantum yield, indicating that in the long term this may be a stressful condition for corals. We see similar responses in growth rates at 30°C for adult and larvae stages. This suggests that P. astreoides is relatively tolerant to high temperatures but that they are dependent on diurnal temperature decreases to avoid a build-up of damage to the photosynthetic machinery.

381

Environmental Science Presenter: Millan Diaz, Karin J.

Mentor: Perez-Jimenez, Jose R.

Title: Bioprospecting for xylose-ferment bacteria

Authors: Karin J. Millan Diaz (Turabo University), Casandra Santiago-nieves (Turabo University), Jose Perez-jimenez (Turabo University)

Abstract

Soceity seeks renewable generation of biofuels to meet global demand. For the production of biofuel it is necessary to generate enough ethanol, which has been the main obstacle. Etahnol is produced by the fermentation of simple sugars. Microorganisms capable of producing ethanol by fermentation are yeasts and fungi, but they do not produce enough ethanol. Nature has a variety of microorganisms with the ability to use biomass as a source of nutrient generated some of these are: yeast, fungi and bacteria. Bacteria can use the organic matter that is generated from different productive activities, transforming waste into useful and renewable resources. The production of biofuel from bacteria do not cause wear and occupies large areas. Our goal is to isolate bacteria capable of fermenting xylose. Agricultural soil samples were inoculated into xylose enriched medium and observed color change to identify as indicative of xylose fermentation. Samples were obtained at the Experimental Station of the University of Puerto Rico in Gurabo. One hundred twenty bacteria capable of fermenting xylose have been isolated, including close homologues to Pseudomonas putida, Citrobacter sp., Enterobacter sp., Burkholderia cenocepacia, Klebsiella pneumoniae and Stenotrophomonas sp.

Environmental Science Presenter: Moreno, Ivia I.

Mentor: Barberena-Arias, Maria Fernanda

Title: Arthropod diversity and nutrient mineralization in green litter decomposition in a simulated hurricane experiment

Authors: Ivia I. Moreno (Universidad del Turabo), Maria F. Barberena-arias (Universidad del Turabo), Sharon Cantrell (Universidad del Turabo) 382

Abstract

Hurricanes generate disturbances in forests such as canopy opening, fallen trees and leaves which in turn alter physicochemical characteristics of the habitat, as well as, decomposer activity and nutrient fluxes. Litter decomposition depends primarily on the interaction among climate, litter quality and biota, as a consequence any change in habitats will result in changes in these factors. Our objective is to evaluate the effects of hurricane driven changes to forests on decomposition, decomposer communities and nutrient mineralization. Specifically, we will study the effect of a hurricane in green litter decomposition, decomposer fauna and nutrient mineralization. This study is part of the Canopy Trimming Experiment 2 performed by the Luquillo LTER at El Verde Field Station. For this, three blocks (A, B and C) were selected, each with two plots of 20m x 20m, one plot was used for control and the other Canopy opening (Trim). Each plot was subdivided into 16 sub-plots, from which three sub-plots (5m x 5m) were randomly selected. In each subplot, litterbags with different mesh sizes were placed. This experimental design represents 3 blocks x 2 plots/block (1 trim/ 1 control) x 3 subplots x 3 litterbag mesh sizes x 4 collecting times, for a total of 216 litterbags. Each of these litterbags were used as the sampling unit. In each one, decomposer fauna and nutrients were measured. Decomposer fauna were retrieved using Berlese Funnels and mineralized nutrients were quantified using WesternAg PRS probes. Preliminary results suggest significant differences in abundance of decomposer fauna and in available nutrient concentration between trim and control plots, and among litterbags. For example nitrogen and phosphorous were significantly higher in trim plots and in large mesh litterbags. Also, decomposer arthropod abundance was higher in large mesh litterbags. These results suggest that when all decomposer arthropods are present, available nutrients are higher. These results will be further analyzed, and interpreted in the context of food web dynamics.

Environmental Science Presenter: Ortiz Rodrí•guez, Dayna M.

Mentor: Marquez, Francisco

Title: SiO2 as catalyst support for the production of synthetic diesel, as a possible source of clean energy

Authors: Dayna M. Ortiz Rodríguez (University of Turabo), Juan C. Arango Lozano (University of Turabo), Abniel Machín De Jesús (University of Turabo), Francisco Márquez Linares (University of Turabo), María D. Cotto Maldonado (University of Turabo)

Abstract

Nowadays we are facing the necessity to find new ways to produce clean fuels. This need becomes from the excessive use of fossil fuels and the well-known adverse environment effects than these fuels 383

represents. This dependency has brought some important problems of contamination such as global warming and climate change, acid rain, alterations of the carbon cycle, among many others. The increase of price and demand of this fuels and the contamination generated by them, makes imperative the search of viable clean technologies looking for the production of clean fuels with high commercial value. Contaminants produced by the combustion of fossil fuels exposed before, represents the challenge to develop new clean fuels.

One alternative that does not require new technology or the investment of a lot of money is the synthesis of clean diesel fuel through the Fischer-Tropsch method (FT). This method produces clean diesel starting from a mix of H2 and CO obtained from renewable or not energy sources. This synthesis produces a mix of linear high weighted hydrocarbons with high purity. The fuel produced this way is clean since doesn't present aromatic compounds or heteroatoms like N or S, hence after combustion these fuels eliminates the production of NOx and SOx, as environment contaminants. To develop the FT reaction is necessary the use of heterogeneous catalyzers. These catalyzers consist in high surface solids where there are deposited metallic particles like Co, Ru and Fe. These high surface solids are known as supports, one of the most popular compounds used to achieve this end is SiO2. Silica oxide (SiO2), is an important inorganic material, it has received research interest over the past decade because of its applications in a vast array of technological fields.

This research introduces the most popular method to synthetize SiO2 microspheres, the St?ber method. Which uses reactants that are not expensive, are easily available; and requires no organic additives. This method allows synthesizing monodisperse microspheres with desired diameter and sizing. The St?ber method consists of hydrolysis and condensation of alcoholic tetra ethyl orthosilicates (TEOS) in the presence of aqueous ammonia. Generally, the synthesis procedure involves mixing the alcohol(s) and ammonia solutions followed by the addition of the TEOS under stirring.

The main objective of this research is to present an easy way to synthetize SiO2 microspheres. Different synthesis temperatures were tested to study the correlation between temperature and size of the microsphere. The characterization of the obtained products were performed through a Scanning Electron Microscopy, equipped with an Energy Dispersive Spectrometer (SEM-EDS). The resulting support could be used for the deposition of catalytic metals to develop the Fischer and Tropsch method to produce clean diesel fuels.

384

Environmental Science Presenter: Ortiz-Maldonado, Yakshi N

Mentor: Restrepo, Carla

Title: Testing a protocol for soil elemental analyses using X-Ray Fluorescence Spectroscopy

Authors: Yakshi Ortiz-maldonado (University of Puerto Rico - Rio Piedras campus), Nydia Santiago (University of Puerto Rico - Rio Piedras campus), Carla Restrepo (University of Puerto Rico - Rio Piedras campus)

Abstract

Silicate rocks rich in calcium (Ca) play an important role in the long-term carbon cycle. Of particular interest are Ca-silicate rocks with coarse textures because they weather into soils highly susceptible to the formation of landslides. Thus recently exposed rock surfaces - landslides and road cuts - have a high potential for weathering of Ca-bearing minerals. As part of a larger study aimed at understanding the role of root microbial communities on weathering of these rocks we focus on granodiorite to develop a protocol that will allow us to establish the elemental composition of rocks and soils and ultimately estimate weathering rates. Towards this end we will use X-ray fluorescence spectroscopy (XRF) to determine the concentration of major, minor, and trace elements in a non-destructive way, while reducing toxic waste. We collected soil samples underlain by granodiorite in the Central Mountain Range of Puerto Rico, in the municipalities of Jayuya and Ponce (~1060 m asl). These soil samples were air-dried, pulverized to 53µm, and mixed with a binder (9:1). We combined different pressures and pressuring times to produce soil pellets. The pellets will be run through a Rigaku ZSX Primus II-XRF analyzer, calibrated using a granite standard (USGS, Silver Plume Granodiorite). The elemental characterization of soils and rocks not only will inform us about the elemental composition and their respective concentrations but also will allow us to estimate weathering rates.

385

Environmental Science Presenter: Soto-Vázquez, Loraine

Mentor: Marquez, Francisco

Title: Synthesis, characterization and photocatalytic activity of ZnONPs in the degradation of phenylbenzimidazole sulfonic acid

Authors: Loraine Soto-vázquez (Universidad del Turabo), Francisco Márquez (Universidad del Turabo)

Abstract

Water pollution has emerged as a primary concern in environmental issues due to the over- consumption of UV-filters specifically in geographical zones such as the Caribbean because of the resilience of these compounds to traditional remediation methods. Photocatalysis, as an advanced oxidation process, has been considered as a promising decontamination method because of it capability to mineralize the pollutant. Zinc oxide nanoparticles (ZnONPs) were synthesized, characterized and employed as the catalyst to evaluate its photocatalytic activity towards the degradation of phenylbenzimidazole sulfonic acid (PBSA). Sphere-like particles of 100 nm were identified with a wurtzite crystal structure. A 90% of photodegradation was achieved under optimum experimental conditions after evaluating the catalyst loading, initial pH and PBSA concentration. Moreover, the degradation of PBSA undergo mainly by a synergistic effect caused by the incident radiation, the oxygen sources and the catalyst employed. Our results suggest the process is a viable option to clean polluted water sources. The photoproducts of PBSA should be characterized to confirm this process as an environmentally viable remediation solution.

Environmental Science Presenter: Derilus, Dieunel

Mentor: Steven Massey

Title: Bioinformatic characterization of rare methanogenic enzymes and Pathways in a seawater anaerobic bioreactor

Authors: Massey, Steven; Louime, Clifford; Gervais, Gary 386

Abstract

Due to its cost effectiveness and sustainability, Anaerobic Digestion (AD) is reputed to be one of the most prominent biotechnologies for wastewater treatment and bioenergy production. Understanding the direct relationship between microbial community structure and the whole metabolome is a prerequisite to enhancing bioreactor performance. However, the traditional 16S rRNA sequencing approach is limited not only because different species respond differently to the Polymerase Chain Reaction (PCR) but also it does not give a good snapshot of the metabolome that is considered as the sum of all metabolic pathways in the system.

In this work, Illumina shotgun sequencing was used to understand deeply the microbial community structure, their function and different dominant metabolic pathways in a two-stage anaerobic reactor fed with Sargassum sp. operated in seawater. Furthermore, the quality of the methane produced, the dominant methanogenesis pathway and the presence of some rare enzymes were also determined.

Taxonomic analysis of the overall microbial community-based M5RN database reveals that Bacteria were the dominant domain (79%), followed by archaea (5.9%), Virus (1.30%) and Eukaryota (1%). A total of 13.7% of the total sequences considered as unknown. Among the archaea, the dominant order was methanomicrobiales (60%) followed by methanosarcinales (38%). In spite of small proportion of methanogenic Archaea detected, Fourier Transform Infrared Spectrophotometry (FTIR) analysis reveals that 65% of the total biogas produced by the system was methane. The functional analysis based reveals that Clustered Based Subsystems (14.47%), carbohydrate (12.5%) and amino acids (8%) metabolism genes were dominant. Interestingly, based on our local BLAST analysis pyrrolysyl-tRNA synthetase that is responsible for the incorporation of the recently discovered 22nd amino acid (pyrrolysine) was detected in our system. The methanomicrobiales are well characterized as hydrogenotrophic archaea, this suggests that hydrogenotrophic methanogenesis is the most dominant methanogenic pathway in high salinity bioreactor contrary to the freshwater system where acetotrophic methanogenesis is reported to be dominant.

388

General Sciences

390

General Sciences Presenter: Rivera-Ramírez, Brenda L

Mentor: Arteaga-Narváez, Edilberto

Title: Dynamic System Modeling in the Learning Process: Attempts for the Building a Model

Authors: Brenda L. Rivera Ramírez (UIA-Metropolitano)

Abstract

In this study we want to describe the initial state and also predict the future states and development of the students' behavior on their academic performance through a computational model. This model is grounded into System Dynamic (SD). We want to respond the question: how change the academic performance of the sciences students in the basic science courses (Physics, Chemistry and Biology)? Among different factor in this process we have three fundamentally factor: the self-efficacy (Bandura, 1977), the motivation (Weiner, 1985) and attitude (Fishbein y Ajzen, 1967) of the students. Other auxiliary variables we consider, were the social context, the affective, the emotional and the curiosity. Also, we consider all possible interactions between the principal variables and between the auxiliary variables through stock and flow diagrams. Our dynamic hypothesis was: "if the level of self- efficacy, motivation and attitude of students is upper then students exhibit higher level of academic performance". We use various computers software in order to build a causal-model and also we used a sensitivity analysis in order to determine how change the structure's model through the time if change some parameters.

According Forrester (1998) the system dynamics combines theory, methods and philosophy for analyzing the behavior of systems. That application has been extended to environmental change, politics, economic behavior, medicine, engineering, psychology and education, and other fields. The SD approach is good for study of complex problems o real problems such as student's learning due no-lineal nature in the learning process.

Academic achievement was classified as high, moderate and low. High academic achievement means that the factor values are in the range of 100% to 80%. Moderate academic achievement in the range of 79% to 60% and under 59% to 0% correspond to low academic achievement.

In the future work, we make field measurement in order to obtain experimental data for help to contract different scenarios of student behavior in academic achievement and obtain a better approximation to the understanding of the academic performance.

392

Geosciences 394

Geosciences Presenter: Benítez Ou, Ashley G.

Mentor: Arce-Nazario, Javier

Title: Analyzing Roads' Density as a Proxy for Impervious Areas in the Watersheds of Puerto Rico Using Spatial Analysis and Statistical Programs

Authors: Ashley G. Benítez Ou (University of Puerto Rico - Cayey)

Abstract

The study of impervious areas of a country is often used to determine the impacts of constructed areas on the hydrography and land resources. Although roads and paved areas prone to be categorized as impervious factors there is no such study that can correlate total impervious areas to roads density in Puerto Rico. In this study, it is assessed the frequency of imperviousness in comparison with roads density based on a land use dataset generated with satellite imagery at 30m resolution. As a result, the extent of impervious areas in the watersheds, were correlated to the roads density calculated for each one. Even though the developed methodology was useful to establish a correlation between imperviousness and roads, it is recommended to generate a detailed classification for the basins to determine with exactitude the contribution of roads for the total impervious areas of Puerto Rico.

Geosciences Presenter: Herrera, Yesenia

Mentor: Ramirez, Wilson

Title: Developing a high resolution record of sea surface temperature and coral reef development from an early Holocene (8,400 to 6,200 ybp..) reef exposure in Cañada Honda, Dominican Republic

Authors: Yesenia Herrera (University of Puerto Rico, Mayagüez Campus), Wilson R. Ramírez Martínez (University of Puerto Rico, Mayagüez Campus)

Abstract

Corals are important paleo-climatological tools because as they accrete their aragonite skeletons they also store a record of fluctuations in the chemical and physical conditions that existed in the sea water 395

surrounding them. The Cañada Honda outcrop located in Enriquillo Lake in southwestern Dominican Republic is a rare and excellently preserved fossil coral reef which allows for the collection of paleo- climate information from the early Holocene. Montastraea faveolata were collected from this outcrop ranging in age from 8,400 to 6,200 years before present. Slabs from these corals were x-rayed to show annual growth bands which were analyzed for annual growth rates. Powdered samples were taken at a millimeter intervals though out each coral slab. Powders were analyzed for ?18O values which were used to calculate sea surface temperatures (SST). Preliminary results show that annual growth rates range from 0.53 cm to 1.0 cm and SST ranged from 20.0 to 29.7°C.

Geosciences Presenter: Toledo Rivera, Jennifer

Mentor: Ramirez, Wilson

Title: Reflectance Variations of Puerto Rican Mangroves Correlated to Heavy Metal Contamination

Authors: Jennifer Toledo Rivera (University of Puerto Rico, Mayagüez Campus)

Abstract

REFLECTANCE VARIATIONS OF PUERTO RICAN MANGROVES CORRELATED TO HEAVY METAL CONTAMINATION

Jennifer Toledo Rivera

Department of Geology, University of Puerto Rico, Mayagüez, PR

Remote sensing techniques have been frequently used to monitor vegetation in coastal environments. Studies have shown that high concentrations of heavy metals have been found in mangrove sediments reflecting a long accumulation period of these metals mostly due to anthropogenic activities. However, spectral studies in mangroves of Puerto Rico are limited. Therefore, this study aimed to retrieve information about the spectral signatures in leaf reflectance of Rhizophora mangle that could be correlated to the presence of heavy metals. Such correlation was evaluated in two mangrove sites along the coast of Puerto Rico (Guánica and Arecibo). Chemical analyses for sediments and mangrove leaves were done for As, Cd, Co, Cu, Mg, Ni, Pb, and Zn using a standard operating procedure based on a manual cold-vapor atomic absorption (CVAA) spectroscopy technique and by an inductively coupled plasma-atomic emission spectrometry (ICP-AES). Sediments samples were found to have higher heavy metal concentration in comparison to leaf samples for both sites. The Normalized Difference Vegetation Index (NDVI) was calculated using field reflectance data and IKONOS images. Arecibo showed to have a higher greener density with a field NDVI of 0.83 ± 0.04 and an IKONOS NDVI of 0.63 ± 0.03 while 396

Rhizophora mangle leaves at Guánica resulted in a field NDVI mean of .81± 0.04 and 0.58 ± 0.03 for IKONOS. Significant difference was found between the field NDVI means for Arecibo and Guánica (P=0.003). No correlation was found between heavy metals and field NDVI values. The same pattern was found between field NDVI and IKONOS NDVI (Arecibo, R2=0.04; Guánica R2=0.03). However, the application of these techniques to digital images requires more investigation and improvement of the processing methods, as well as, the integration of other parameters such as mangrove coastal proximity, tidal events and chlorophyll-a content.

Keywords: Mangrove; NDVI; Heavy Metals; Puerto Rico

398

Life/Biological Sciences

400

Life/Biological Sciences Presenter: Alejandro, Michel

Mentor: Acevedo, Miguel

Title: Exotic species as drivers of ecological networks: Implications for community stability

Authors: Michel Alejandro (University of Puerto Rico - Río Piedras), Elvis Melendez-ackerman (University of Puerto Rico - Río Piedras), Miguel A. Acevedo (University of Puerto Rico - Río Piedras)

Abstract

Natural communities are more than just the assembly of species in a given space, they also encompass the amount and frequency of interactions among these species resulting in complex ecological networks. In 1972, Robert May linked these components of ecological networks consisting of different types of interactions (e.g. mutualistic, trophic, etc.) with community stability. Other studies followed, showing that variation in architectural patterns of natural communities were linked to the types of interactions of the beholding communities. For example, in mutualistic networks, a nested architectural pattern (i.e. when specialist species interact with generalists and vice versa) has been found to increment network cohesiveness, facilitating biodiversity maintenance. In contrast, modular patterns (i.e. degree of compartmentalization of interactions) are believed to destabilize mutualistic networks. The fact that mutualistic interactions mediate important ecological processes shaped the guideline of this study to look at how ecological disturbances, such as the introduction of an exotic species, alter the topological features of mutualistic networks. Building on the introduction of exotic species, their effects vary across a wide spectrum, altering the architecture of ecological networks accordingly. They are known to impact mutualistic systems in their introduced range by: modifying community's species composition, establishing more connections with generalist over specialist partners, disassembling native communities through competitive dynamics, among others. Although exotic species effects on their introduced range have been widely studied, we still know very little how their varied strategies of impact on natural communities modify the architectural pattern of mutualistic networks and its consequences for community stability. Thus, the major aim of this study is to translate the ecological impacts of exotic species in resulting architectural patterns of ecological networks and asses its implications for community stability. To do this, I'll address the following questions: i) Is the architectural pattern of ecological networks of natural communities different between communities with and without exotic species?; and if so, ii) What are the implications associated with the resulting network structure for community stability? I hypothesize that i) the architectural pattern of the ecological networks will be different between communities with and without exotic species, predicting exotic species to stablish more connections with generalist partners and possibly disrupting interactions of other network participants through competitive strategies. Additionally, ii) these differences in structure will translate 401

into meaningful ecological implications for community stability, explained in terms of community persistence (i.e. the proportion of persisting species once equilibrium is reached in a series of simulations).

Life/Biological Sciences Presenter: Correa Velez, Karlen E.

Mentor: Rios Velazquez, Carlos

Title: Detection of Vibrio parahaemolyticus in the Clam Phacoides (Lucina) pectinatus and the Oyster Crassostrea rhizophorae from the Southwest Coast of Puerto Rico

Authors: Karlen E Correa-vélez (UPR-Mayaguez), Carlos Ríos-velázquez (UPR-Mayaguez), Mildred Chaparro-serrano (UPR-Mayaguez)

Abstract

Seafood has become a healthy food choice for people, but along with nutritional benefits come with the potential risks to become a vehicle of transmission of foodborne bacteria that can cause illness. Bivalves such as clams and oysters have a particular concern for the presence of pathogenic bacteria such as Vibrio parahaemolyticus and Vibrio vulnificus. This invertebrates accumulate bacteria during their filter feeding. Recently, the United State Centers for Disease Control and Prevention (CDC) estimates an increases incidence of Vibrio infections of 7,880 cases per year. The Food and Drug Administration (FDA) in the United States and other regulatory agencies throughout the world, recognized Vibrio parahaemolyticus as the leading cause of human gastroenteritis associated with seafood consumption and other seafood-associated illness. In Puerto Rico, there are no laws or regulatory agencies that assess the quality of bivalves for sale. Therefore, the Island does not have statistics on the incidence of foodborne diseases caused by consumption of raw bivalves. This study was driven using the FDA in the Bacteriological Analytical Manual (BAM) for the detection of Vibrio parahaemolyticus strains on oysters and clams samples from the southwest coast. The enrichment on alkaline peptone water, the selection of Vibrio on selective- differential media Thiosulfate Citrate Bile Salts Sucrose (TCBS) and differentiation of species based on grow in different concentration of NaCl (0%, 3%, 6%, 8% and 10%) were performed such as standardized test. The study was able to detect a 13 strains of Vibrio parahaemolyticus that show a typically colonies of 2-3mm in diameter, round, opaque, green or bluish. All isolates can grow in concentration of 3%, 6% and 8% of NaCl, such as characteristic from the specie. These results show the presence of Vibrio parahaemolyticus in bivalves of the southwest coast of Puerto Rico. Although, this study aims to develop awareness of the risks that exist by consuming raw shellfish.

402

Life/Biological Sciences Presenter: De Jesus Cruz, Moises

Mentor: Rios Velazquez, Carlos

Title: Genome-based Molecular Characterization of the Rhodobacter sphaeroides bacteriophage øR3-PR2 isolated from Puerto Rico

Authors: Moises De Jesus Cruz (University of Puerto Rico-Mayaguez Campus), Dr. Carlos Rios Velazquez (University of Puerto Rico-Mayaguez Campus)

Abstract

Numerous bacteriophages have been extensively well characterized, mostly in Gram-positive bacteria and ?-proteobacteria. Nonetheless, knowledge of the mechanisms of the Rhodospirillaceae-specific bacteriophages is little. A DNA-containing Rhodobacter-specific bacteriophage designated øR3-PR2 has been isolated from a water reservoir in Puerto Rico, and its entire genome sequence was obtained and analyzed. The R. sphaeroides phage øR3-PR2 is capable of infecting Rhodobacter sphaeroides 7001 and 2.4.1 under aerobic conditions. The øR3-PR2 genome was sequenced through the construction of the shotgun library and Illumina next-generation sequencing.

A whole-genome analysis of the bacteriophage øR3-PR2 showed that its virion encapsulates 52.5 kb linear DNA which contains 85 putative CDSs. The analysis done using Glimmer and GeneMarkS revealed that the phage genome consists of 39 coding sequences in upstream orientation, and 46 are transcribed in downstream orientation. Annotation via protein comparisons using BLASTP led us to the identification of the phage tail tape measure protein and a putative DNA polymerase. The bacteriophage øR3-PR2 belongs to the family Siphoviridae, but its sequence is different to other Siphoviridae and to other Rhodobacter-specific bacteriophages. All the data collected in this study confirm that the bacteriophage øR3-PR2 is different from the previously R.sphaeroides bacteriophages previously reported in the literature and contains a different genome sequence in comparison with the genome sequences submitted in the data bases. The information gathered through the genome-based molecular characterization of the R. sphaeroides phage øR3-PR2 and its further analysis might enlighten the mechanisms and genes involved in the host-phage interaction, infection and transduction; data that will be basic for the development of transductional genetic tools.

Keywords: Bacteriophages, Rhodobacter sphaeroides, Full genome sequence

403

Life/Biological Sciences Presenter: De Jesus Villanueva, Christina

Mentor: Papa, Riccardo

Title: Invading social media: Invasive species awareness through the web.

Authors: Christina N. De Jesús Villanueva (Universidad de Puerto Rico-Rio Piedras), Angel Rivera- colón (Universidad de Puerto Rico-Rio Piedras), Steven Van Belleghem (Universidad de Puerto Rico-Rio Piedras), Yazmin M. Sostre Reyes (Universidad de Puerto Rico- Humacao), Rafael A. Rivero (Universidad de Puerto Rico-Rio Piedras), Riccardo Papa (Universidad de Puerto Rico-Rio Piedras)

Abstract

Social media has become a predominant platform to inform large masses of people in short amounts of time. They have gone beyond their initial purpose of keeping friends connected, to becoming an outlet for the dissemination of information. In a matter of hours information can travel throughout the world. If a natural disaster strikes, disaster relief information becomes readily available. Similarly, educational material is condensed into small clusters and is shared by thousands of people. In this project, we use social media platforms, mainly Facebook, Twitter and WordPress, to provide information on invasive species. Invasive species pose a major conservation concern; they are regarded as the second (to habit loss) largest threat to biodiversity. By providing information about the problems associated with these species, our goal is to increase awareness and advocate for their prevention. We present a subset of the information found on our websites, together with the extent of the audience reached. We focus on number of user demographics and expose the content that has been most successful in gaining attention. We expect to contribute to a growing body of scientific social media sites aimed at conservation.

404

Life/Biological Sciences Presenter: Del Rio Ramos, Christian

Mentor: Rios-Hernandez, Luis A.

Title: Diversity and Variability of the Dominant Enterococci in Human Stool Samples

Authors: Christian Del Rio Ramos (University of Puerto Rico at Mayaguez), Luis A. Ríos-hernández (University of Puerto Rico at Mayaguez)

Abstract

The intestinal flora of humans is known to harbour a multitude of microorganisms. One important genus is Enterococcus, while it only composes less than 1% of the total gut flora, the ability to harbour a wide array of virulence factors and antibiotic resistance grant it medical importance. However, not much is known about how the species composition behaves in the human gut. In order to fill this gap, the focus of our study was to analyse and compare the dominant enterococci population of two subjects via daily stool sampling for a period of 7 consecutive days. A total of 140 Enterococci per subject were isolated and subjected to antibiotic resistance assays and molecular analysis. Molecular analysis allowed the comparison of isolates at the species level, presence of virulence factors and ultimately at the strain level. Total enterococci population was around 106 to 108 for both subjects; however species composition and dominance were different. In subject #1, the dominant enterococci vary daily but were limited to E. faecium and E. faecalis, with two transitions in seven days. Of the two species, E. faecalis was the most virulent with vancomycin resistance and gelE virulence factor for 3 days while E. faecium only had gelE. In subject #2, E. faecalis was the only dominant species during the sampling period. Although species dominance was consistent, the strains and the frequency of virulent factors among the dominant species were different and higher than in subject #1. Although Enterococci were always present at similar densities, the dominant population changed daily. One subject had a higher frequency of strains with virulence factors, gelE and esp, while the other had a wider range of antibiotic resistances, vancomycin being the most notable. Screening for colonization of virulent strains during hospital admittance might not safeguard the patient's health because of the high strain transition frequency.

405

Life/Biological Sciences Presenter: Delgado, Peter

Mentor: Burrowes, Patricia

Title: Retreat site temperatures may explain recent range contraction in Eleutherodactylus portoricensis

Authors: Peter Delgado-suazo (Department of Biology, University of Puerto Rico, Rio Piedras), Patricia A. Burrowes (Department of Biology, University of Puerto Rico, Rio Piedras)

Abstract

The rates of global warming are predicted to increase with latitude, however, tropical species may be facing greater risks due to higher physiological sensitivity. While also affecting phenology, breeding patterns, and disease occurrence, climate change is having an impact on many species' geographic range. Several tropical ectotherms, particularly amphibians and reptiles, have altered their distribution ranges, either by seeking cooler microhabitats in their current range or by displacing to higher elevations. Such impact can be seen in amphibian populations of continental tropical America, where climate change may be a main driver of biodiversity loss. Herpetofaunal distribution change as a consequence of climate warming in the Caribbean, however, has been seldom studied. Here we study the daily operative temperatures of Eleutherodactylus portoricensis, a species that has undergone recent population declines and extirpations from most of its historical distribution range, particularly at low elevations. Using frog agar models and thermocouplers, we assessed operative temperatures of E. portoricensis along its historical elevation gradient at the Luquillo and Cayey mountains, Puerto Rico, during the cool-dry season. As expected, retreat site temperatures were highest during mid-afternoon hours, representing critical values for E. portoricensis thermal tolerance. In addition, retreat site temperatures in the Cayey mountains were generally slightly warmer at comparable elevations. Body temperatures obtained using frog agar models serve as a proxy to predict potential physiological limitations to a species' altitudinal distribution. Considering the narrow thermal and hydric tolerance of this species, our results suggest that climate change may be the driver of the observed altitudinal range contraction. Experimental studies will confirm the physiological limitations of this species.

406

Life/Biological Sciences Presenter: Figueroa Rosado, Maria M

Mentor: Suárez, Edu

Title: Role of Calcium Sulfide Nanoclusters in Intrinsic and Extrinsic Apoptotic Pathways in Non-Small Lung Cell Adenocarcinoma

Authors: Maria M Figueroa Rosado (Pontifical Catholic University), Kevin Muñoz Forti (Pontifical Catholic University), Bryan Torres (University of Puerto Rico at Ponce), Miguel Castro (University of Puerto Rico at Mayagüez), Edu Suárez (University of Puerto Rico at Ponce)

Abstract

Apoptosis is the process of programmed cell death, which is characterized by metabolic changes and energy-dependent mechanisms. This process is normal in the development and regeneration of tissues to insure proper functionality of these systems and it can also function as a defensive system against disease or noxious agents. Still, a variety of internal and external agents can trigger the apoptotic cascade. They are categorized in two signaling pathways based on the origin of the stimuli and the mediators involved as extrinsic and intrinsic. In apoptosis, caspases-8 and -9 are responsible for the activation of both apoptotic pathways. Failure on activation of pro-apoptotic caspases is considered a major contributor to the survival of tumor cells, inducing a malignant transformation that supports tumor growth and cancer metastasis. Previous studies in our laboratory, showed that non-small lung cell adenocarcinoma cell line (HCC827) treated with patented calcium sulfide nanoclusters (CaS) (Castro & Rivera, 2015) had an increase trend for inducing apoptosis starting at 48 hours that become statistically significant at 72 hours (pusters may represent the next generation for treatment, not only of lung cancers, but many other types of cancers by inducing apoptosis.

407

Life/Biological Sciences Presenter: García Recinos, Liza I.

Mentor: Burrowes, Patricia

Title: Skin Microbiota Variation at Individual and Population Level in the Common Coqui (Eleutherodactylus coqui)

Authors: Liza I. García Recinos (UPR-Río Piedras), Patricia Burrowes (UPR-Rio Piedras), María G. Domínguez-bello (NY University School of Medicine)

Abstract

Microbial communities from amphibian skin have been of interest lately due to its possible protective role against the fungal pathogen Batrachochytrium dendrobatidis. The majority of studies focus on the ventral surface of the skin and others on whole-body surface. However, differences among skin regions have not been well studied to determine a possible effect on the results obtained. In addition, a few studies have shown differences in skin microbial communities among populations of the same species. Here we characterize the skin microbiota in two populations of a terrestrial frog, Eleutherodactylus coqui located at different elevations (480 and 820 msnm) at El Yunque National Forest, Puerto Rico. In addition, we determine if there is a difference in microbial composition between dorsal and ventral surfaces of frogs, and if this difference is maintained among populations. For this we swabbed the skin of 10 adults E. coqui at each location, to obtain microbial DNA and sequenced the 16S rRNA gene. Results revealed that microbial community composition is significantly different between both populations of E. coqui, while no significant differences were found for ventral and dorsal skin surfaces. These findings will help to better characterize the skin microbiota of E. coqui in ongoing studies, taking into account that while skin regions sampled are not important, elevation may explain population-level variation in skin microbial communities.

408

Life/Biological Sciences Presenter: Gonzalez-Rosario, Karleen M.

Mentor: Perez-Jimenez, Jose R.

Title: Enviromental Risk Encompassed by Biocatalytic Diversity for Arsenate Respiration

Authors: Karleen M. Gonzalez-rosario (Universidad del Turabo), Jose R. Perez-jimenez (Universidad del Turabo)

Abstract

Arsenic represents a priority pollutant due to diverse health effects and hardly noticeable presence in nature. Arsenate (AsV) usually is bound to the geological matrix while arsenite (AsIII) is more mobile in the water column. The dissimilatory arsenate-reducing prokaryotes (DARP) constitute a taxonomically diverse group that derives energy from arsenate respiration. Despite the limited biochemical understanding, arsenate respiration is ultimately catalyzed by the arsenate respiratory reductase, encoded by the arrA gene. Most information currently available on ARR is provided from genomes minimally annotated. The congruency between nearly complete arrA and 16S rDNA phylogenies suggests ancient origin for arsenate respiration. There is need to assess the diversity of the arrA genes to describe and model predominant features for risk assessment. Our aim is to examine the prevalence and diversity of arrA genes to resolve sentinel regions for environmental health. Genetic homologs for arrA from known DARP (Desulfosporosinus sp. Y5, Bacillus macyae, Shewanella sp. ANA-3, and Sulfurospirilum carboxyolevorans) were searched in GenBank and deposited genomes. We established a database of thirty-one nearly complete arrA sequences (10 for Firmicutes and 6 for Epsilonproteobacteria). Nine additional homologues were detected among bacterial genome projects for Firmicutes (921) or Epsilonproteobacteria (81). Additional homologues were fond for Archaea (9), Gammaproteobacteria (7), and Betaproteobacteria (4). No bidirectional oxido-reductases were detected. In silico analyses for arsenate reductase produced several sentinel regions to design bioreporters. The absence of arrA gene from most prokaryotic genomes suggests prevalence limited to uncommon taxons. However, the nearly complete arrA represents a useful biomarker to ascertain prokaryotes capable of arsenate respiration and monitor the risk of arsenic mobilization in nature.

409

Life/Biological Sciences Presenter: Hernandez- Matias, Liz

Mentor: Washington, A. Valance

Title: Use of CRISPR-CAS9 laboratory experience to increase students academic knowledge, auto-conception and simultaneously advance scientific knowledge.

Authors: Anthony Valance Washington (University of Puerto Rico), Liz Hernandez Matias (Univesity of Puerto Rico)

Abstract

Calreticulin (CALR) protein is involved in many cell functions, including the cell surface expression of MHC class I (MHCI) peptides.1 It is known that C and P-domain of CALR are responsible of MHCI expression into the surface, but which specific amino acids (s) are responsible for this expression is still not known. For this reason, my research project will be focused on (Aim 1) create model cell lines using CRISPR- Cas9 technique to identify the specific amino acids in the protein Calreticulin (CALR) responsible for the surface expression of MHCI. Furthermore, I will incorporate an educational research component that (Aim 2) will evaluate if the use of CRISPR-Cas9 technique as a laboratory experience could increase students' auto-conception, academic knowledge development, and perception of science.

In order to identify those amino acids responsible for MHCI surface expression, I have used CRISPR-Cas9 on hepatocytes cells to induce mutations on the CALR C-terminal domain. Endonuclease and Sequencing results have shown an efficient cut in the target sequence. Now, I am characterizing the cells that were modified to categorize them by the presence of MHCI on the surface of the cell. Afterward, with the help of high school students and using the CRISPR- Cas9, I will identify the specific amino acids involved in the cell's surface expression of MHCI.

410

Life/Biological Sciences Presenter: Lopez De Jesus, Edgardo

Mentor: Massey, Steven

Title: Relationship between body size, effective population size and DNA repair capacities

Authors: Edgardo Lopez De Jesus (University of Puerto Rico Rio Piedras), Steven E. Massey (University of Puerto Rico Rio Piedras), Jenelys Ruiz (University of Puerto Rico Bayamon), Charles Sanfiorenzo (University of Puerto Rico Bayamon)

Abstract

The most essential molecules of all living organism, that store the genetic information is DNA. The stability and integrity of this molecule can suffer damage thanks to the environment or errors in replication during cell division, leading to possible mutations and even disease. To counteract these possible situations, species have evolved mechanisms to repair DNA and try to maintain the purity that distinguishes us as different species. It is predicted that the DNA repair capacity (DRC) in large bodied mammals (Whales, elephants, etc.) is higher, and this should correlate to the number of DNA repair genes present. This research is focus to test the body size hypothesis of DNA repair and tumor suppressor genes using genome sequences. To maintain a QC environment, we will perform an analysis of false positives produced by assembly errors using read depth analysis, those allows the analysis of recently diverged ORFs, and also understand positive correlation between body size and longevity, which has been linked to an increased efficiency in DNA repair. Pairwise sequentially Markovian coalescent-(PSMC) method will be implemented to calculated link effective population size-Ne with body size. To get a direct method to measure the strength of selection, levels in genome heterozigocity will be analyze using protein coding genes, the relative frequency, and predicted effects of nonsynonymous SNPs. The aim of this project is to test the predicted link between body size and DRC and establish an inverse relationship between body size and Ne using mammalian genomes in silico analysis.

411

Life/Biological Sciences Presenter: Lopez-Cruz, Luis M.

Mentor: Serrano, Adelfa E.

Title: DNA Repair Mechanisms as a Factor in Drug Resistance in the Human Malaria Parasite Plasmodium falciparum

Authors: Luis M. Lopez-cruz

Abstract

The rapid development of drug resistance by the human malaria parasite Plasmodium falciparum is a subject of concern and interest for the medical and research community around the world. This resistance is due to various factors that can be either cellular or environmental. One of these factor can be defective DNA repair mechanisms. Recent studies suggest that defective DNA repair mechanisms in the parasite are related with development of drug resistance and these defective mechanisms can be the first step of the Accelerated Resistance to Multiple Drugs (ARMD) phenotype proliferation. Here, we present a general overview and description of the DNA Repair mechanisms in the malaria parasite P. falciparum. Also, we evaluate the importance of understand the ways by which these mechanisms work and their relationship with the development of drug resistance.

Life/Biological Sciences Presenter: Maldonado-Hernández, Rafael

Mentor: Lasalde, Jose

Title: Preparation of nAChR crystals for high resolution studies using the detergent analog LFC16.

Authors: Rafael Maldonado Hernández (UPRRP), Bianca Valdés (UPRRP), José O. Colón (UPRRP), Orestes Quesada (UPRRP), José A. Lasalde (UPRRP)

Abstract

The nicotinic acetylcholine receptor (nAChR) is a prime example of a multimeric membrane complex that although one of the most widely studied ion channels, its high-resolution structure has remained elusive. These receptors are important as the biological target for the therapeutic development is in a 412

great number of diseases such as the Alzheimer Syndrome, Myasthenia Syndrome Parkinson disease, among others. We have recently carried out lipidomics/activity studies with nAChR solubilized in different detergents that indicated that a comprehensive approach on detergent structure and solubilization conditions could provide important information on the preparation of functionally active complex membrane proteins for structural studies. Using the aforementioned approaches our laboratory has prepared nAChR crystals for structural studies. We extracted the protein from the tissue of Torpedo california, using LFC-16 as a detergent, followed by purification and concentration for crystallization trials. We have performed X-ray diffraction experiments using the GM/CA-23 ID beam line at the Argonne laboratory in Chicago (APS). Also in collaboration with CDI (http://www.cdi-lab.com) we managed to prepare 17 monoclonal antibodies (mAbs) specifics for nAChR. Our next goal is to use these mAbs to enhance crystal formation and also improve the quality of the nAChR crystal diffractions.

This research was supported by the National Institutes of Health NIGMS grants 1R01GM098343 (JALD) and COBRE NIEF 1P20GM103642 (J.R and JALD)

Life/Biological Sciences Presenter: Matías López, Katia Y

Mentor: Lugo, Ana

Title: Characterization and validation of the CDC Pan-Dengue Real Time RT-PCR Assay for Dengue Diagnosis

Authors: Katia Y. Matías (1Centers for Disease Control and Prevention, Division of Vector Borne Diseases, Dengue Branch, San Juan, PR. and InterAmerican U), Gilberto A. Santiago (Centers for Disease Control and Prevention, Division of Vector Borne Diseases, Dengue Branch, San Juan, PR), Jorge L. Muñoz-Jordán (Centers for Disease Control and Prevention, Division of Vector Borne Diseases, Dengue Branch, San Juan, PR)

Abstract

Dengue virus (DENV) is the most widespread mosquito borne viral disease in the world. DENV is a positive-sense, single stranded RNA virus from the genus flavivirus, family Flaviviridae. There are four genetically distinct but closely related dengue virus serotypes that are transmitted by the mosquito Aedes sp. It was estimated that by 2010 there were 96 million symptomatic and 294 million non- symptomatic cases of dengue worldwide.

Typical laboratory diagnosis is achieved by a testing algorithm of acute and convalescent phase paired samples; however, an accurate diagnosis can be achieved in the acute or febrile stage 0-5 days of symptoms with a single serum specimen. During this stage, viremia levels are high and present an 413

optimal target for molecular diagnostics. Although the WHO recommends detection of viral RNA during the acute stage, there is only one assay approved by the FDA for the diagnosis of dengue in humans: the CDC DENV 1-4 Real Time RT-PCR assay for detection and typing of dengue virus. This assay has been proven to be highly specific, highly sensitive and provides the capacity of serotype identification with the convenience of a multiplex format where all 4 serotypes can be tested simultaneously in the same sample and same reaction. A caveat for the use of this assay is that it requires a complex qPCR thermocycler with the capacity to detect fluorescence at 4 specific wavelengths. Many public health and diagnostic laboratories are not equipped with such instruments, therefore are unable to use the aforementioned assay.

The CDC Pan-Dengue Real Time RT PCR assay is a molecular diagnostic system that simplifies dengue virus RNA detection using a simple set of oligonucleotides complementary to a highly conserved region among all dengue virus serotypes. A single Taqman probe is used 5'-labeled with FAM is used: the most common fluorescent dye present in every qPCR instrument. This simple approach provides users with a simple and easy to use assay that can be run in any qPCR instrument. The simplicity of the assay significantly reduces the space for user error but sacrifices the serotyping capacity. This assay has been recently introduced into clinical testing at the CDC Dengue Branch and has been shown to perform with high sensitivity and specificity; nonetheless a comprehensive performance evaluation is required.

To evaluate the analytical performance of this assay, a panel of heat-inactivated contemporary strains of dengue virus suspended in human serum was constructed per serotype. The analytical sensitivity and limit of detection were determined. Performance in clinical samples was evaluated using a panel of clinical specimens PCR positive obtained from dengue confirmed patients in Puerto Rico through the Passive Dengue Surveillance System. To assess the ability of the assay to detect contemporary dengue strains circulating globally, a panel of international dengue virus isolates representing all clinically- relevant genotypes was tested. To this point, the analytical and clinical sensitivity of the Pan-Dengue Assay on all dengue serotypes is comparable to the FDA-approved CDC DENV 1-4 Real Time RT-PCR assay.

Life/Biological Sciences Presenter: Morales-Medina, William R.

Mentor: Rios-Hernandez, Luis A.

Title: Assessing the Potential of Different Tropical Biomasses as Feedstock for Biogas Production through Anaerobic Digestion

Authors: William R. Morales-Medina (University of Puerto Rico at Mayaguez), Luis A. Ríos- Hernández (University of Puerto Rico at Mayaguez) 414

Abstract

Second generation biofuels are considered a potential alternative to face the peak oil crisis. The challenge in the development of these non contaminant fuels is the finding of a viable biomass. Puerto Rico, a sub-tropical island, is rich in flora and other potential biomasses. In this island, climbing vines compose the 20% of the flora population, meanwhile marine algae and seagrasses are highly abundant in the littoral zone. This fact lead us to study the potential of these biomasses as feedstock for biogas production through anaerobic digestion. We used 10 species of biomasses and submitted them to a aqueous extraction pretreatment through blending, in which we separated the water-soluble and non- soluble fractions. Both fractions were anaerobically digested and compared with untreated biomass. Reactors were prepared using 160mL serum bottles and inoculated with effluent from anaerobic reactors previously enriched with similar biomasses. Methane production and biodegradation were measure by GC and HPLC. Results showed that climbing vines yielded more methane than seagrasses and most algae. The effect of the pretreatment varies with every biomass, but liquid fraction yielded less methane than untreated biomass in all cases. Up to 78.16 L/Kg of methane was obtained from the solid fraction of Epipremnum spp., potentially producing up to 720 W/hr per Kg of biomass, meanwhile untreated Dioscorea spp. and Acanthophora spp. yielded almost 60 L/Kg (~560 W/hr per Kg). These three feedstocks showed a net methane production greater than the woody biomass production average of 50 L/kg, what makes them excellent candidates for industrialization.

Life/Biological Sciences Presenter: Muñoz-Forti, Kevin

Mentor: Suarez, Edu

Title: In-Vitro Effect of Calcium Sulfide Nanostructures on Non-Small Cell Lung Adenocarcinoma Cell Cycle Succession and Oxidative Environment

Authors: Kevin Muñoz-forti (Pontifical Catholic University of Puerto Rico), Maria Figueroa (Pontifical Catholic University of Puerto Rico), Bryan Torres (University of Puerto Rico at Ponce), Miguel Castro (University of Puerto Rico at Mayagüez), Edu Suarez (University of Puerto Rico at Ponce)

Abstract

Lung cancer is the number one cause of death among deaths due to cancer in the United States independent of gender. Current treatments focus on surgical removal of tumors and surround tissue, chemotherapy and radiation therapy. Side effects of the aforementioned treatments have been shown to be detrimental to a patient's health and wellbeing and are capable of causing secondary neoplasms. Recently, nanotechnology has shown promise in providing safer and more efficient therapy options for 415

cancer patients. Our colleagues from the University of Puerto Rico at Mayagüez synthesized nanostructures composed of calcium sulfide (CaS). Due to both calcium and sulfur being incorporated in numerous biological pathways with the former being a mediator in apoptosis, we expect these nanostructures to be biocompatible and with low side effects. In this study, we evaluated the effect of CaS nanostructures on pulmonary adenocarcinoma cells by incubating ATCC CRL-2124 cell line in the presence of CaS nanostructures [3.8 µM], Etoposide [10 µM], and DMSO (vehicle) for 24-, 48-, and 72- hours after a single dose at time 0. We hypothesized that CaS nanostructures would suppress the cells' proliferation by interfering with their cell cycle phases. We performed cell-based assays to estimate the stage of mitotic cell division and viability. We observed that CaS nanostructures suppressed the Sub-G1 phase at 24 hours and S phase after 48 hours resulting in an increase of cells in the aforementioned phases compared to control (p?0.05). Based on these results we analyzed the oxidative stress levels of the supernatants at each time point to evaluate if the oxidative/antioxidant environment contributed to the cell cycle results. We observed decreased oxidative stress in samples treated with CaS nanostructures after 48 and 72 hours when compared to the DMSO control (p?0.05). These results provide a platform for elucidating the mechanism of action of CaS interfering with the cell cycle, which may lead to new alternative therapies for lung cancer. Currently we are planning PCR arrays targeting cell cycle mediators and cytokines.

Life/Biological Sciences Presenter: Ortiz Orengo, Viviana M.

Mentor: Guzmán Blas, Rolando

Title: Mathematical Simulation on T-CD4 Cells Behavior Analysis Against HIV Infection

Authors: Viviana Ortiz Orengo (Universidad del Sagrado Corazón), Krystel Ocasio (Universidad del Sagrado Corazón), Ysabel Colón (Universidad del Sagrado Corazón), Prof. María Lázaro (Universidad del Sagrado Corazón)

Abstract

Using a mathematical model the behavior of CD4 T cells against infection with HIV virus is simulated. Being able to describe this dynamic is a crucial factor in the development and possible complications of the infection in the future. Values such as death rates, activation rates, and infection rates are acquired in order to determine if in fact these values offer enough susceptibility to be manipulated in the future. Programs such as "SciLab" and "Mathematica" help demonstrate, with previously determined parameters, how the quantity of infected T cells and viral charge affect or not the immunologic system's response.

416

Life/Biological Sciences Presenter: Pena Jimenez, Janelle

Mentor: Burrowes, Patricia

Title: Frogs that select retreat sites in forest light-gaps are more likely to avoid an infectious disease

Authors: Patricia Burrowes (Universidad de Puerto Rico Recinto Rio Piedras), Janelle Peña (Universidad de Puerto Rico Recinto Rio Piedras)

Abstract

During the past decades, the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd), has played an important role in driving amphibian declines by causing a skin disease known as chytridiomycosis. Nevertheless, in certain places of the world, some species of amphibians have persisted despite Bd. This is the case of the Puerto Rican frog, Eleutherodactylus coqui. Mechanisms for host persistence after an epidemic, involve pathogen avoidance, or the evolution of more complex resistance or tolerance strategies. The objective of our study was to evaluate the potential for behavioral thermoregulation, as a way to avoid Bd. We hypothesized that E. coqui utilizing retreat sites under forest light gaps are able to avoid Bd, by maintaining body temperatures that are above the temperature optimum for Bd growth (18-21°C, in Puerto Rico). We used agar models and thermal couplers to measure operative body temperatures (Te) of frogs in different forest retreat sites under: (1) light gaps and (2) dense canopy. Results revealed significant heterogeneity of temperatures between treatments independent of season. Operative temperatures were on average 0.75 °C warmer under forest light gaps. More importantly, we found that during the cool-dry season, when frogs are more vulnerable to disease, they can avoid Bd only by selecting retreat sites under the forest light-gaps. Our results are important because they provide the baseline data for further experimentation to determine if Bd-infected frogs choose warmer retreat sites, and if there is differential rate of recovery from chytridiomycosis associated to retreat choice.

417

Life/Biological Sciences Presenter: Rabelo Fernandez, Robert J.

Mentor: Rios Velazquez, Carlos

Title: Seaching for Caracolus Marginella Resistome

Authors: Robert J. Rabelo Fernandez (University of Puerto Rico at Mayaguez), Carlos Rios Velazquez (University of Puerto Rico at Mayaguez)

Abstract

Caracolus marginella is a land snail from Caribbean islands and Central America with the ability to adapt to different environments where biotechnological potential has not been explored. Antibiotic Resistance (AR) is currently one of the most important public health threats faced worldwide. Recent studies highlighted the unappreciated diversity and novel genes in the snails' microbiome and their impact in activities such as copper homeostasis and Resistance to heavy metals, including genes involved in AR. The use of culture independent approaches such as metagenomics has become a powerful culture independent technique that facilitated the unraveling of novel activities including AR in diverse environments. Our research focused in the generation of Caracolus marginella gut microbiome metagenomic libraries from three different regions of Puerto Rico and assess the AR activity. High molecular weight (40kb) metagenomic libraries were generated from East, South and West regions of Puerto Rico using a direct DNA isolation method and Epicentre CopyControl Kit averaging 11,000, 16,700 and 16,000 clones, respectively. After determining the Minimal Inhibitory Concentration (MIC) to Ampicillin (Amp) of Escherichia coli Epi300 with pCC1FOS vector with no inserts; the Metagenomic Libraries generated were spread on LB plates with MICs ranging from 1X-10X. Clones of all three libraries showed AR (too numerous to count) for MIC 1X and 2X, while libraries from South and West showed AR for MIC as high as 8X;specifically, sixteen (0.66%) and twenty-two (0.26%) clones respectively of the each population screened. Meanwhile, libraries from East only showed clones resistance up to 4X MIC. These results are the first steps in gaining a better understanding of C. marginella gut microbiome resistome. Work is in process to identify the gene(s) responsible for the resistance activity in snail gut libraries by TN mutagenesis.

418

Life/Biological Sciences Presenter: Rivera Rosario, Francisco

Mentor: Hendricks, Timothy

Title: Retinoic Acid Induced Differentiation of dI6 Dorsal Interneurons from E12.5 Mouse Spinal Cord Neural Stem Cells.

Authors: Francisco Rivera Rosario (Interamerican University Bayamon), Timothy Hendricks (Interamerican University Bayamon), Jose Luis Roig (Universidad del Este)

Abstract

During mammalian development of the neural tube, eleven distinct progenitor cell populations are specified by the combinatorial expression of unique combinations of transcription factors. This patterning program is specified by dorsal, ventral and lateral, exogenous morphogenic signaling molecules. While the specification of certain progenitor populations, specifically those located at the dorsal and ventral extremes, has been recapitulated in vitro, the specification of intermediate progenitors is incompletely understood. Here we examine the signaling events that lead to the specification of the intermediate pd6 progenitors, which give rise to dI6 interneurons. For our analysis we utilize the dI6 interneuron marker WT1. Embryonic mouse spinal cords were used to generate embryonic neural stem cells (NSC). Original NSC cultures were expanded utilizing proliferative factors EGF and FGF-2. NSC cultures were then removed from proliferative media and resuspended in a differentiation media containing Retinoic Acid (100 nM) for the induction of dI6 dorsal interneurons. Cell specific TF expression was assessed by immunocytochemistry. Preliminary data of differentiated mouse E12.5 NSCs cultures demonstrates the induction of the WT1+ dI6 interneuron population in vitro, four days following RA exposure, while after six days of RA exposure, no WT1+ cell population is observed. These observations suggest that the induction of WT1+ dI6 dorsal interneurons is mediated exclusively by RA signaling and is independent of exogeneous dorsal and ventral morphogenic signaling molecules. Our induction protocol will allow for further delineation of the molecular mechanisms that govern dI6 interneuron differentiation in the developing spinal cord.

419

Life/Biological Sciences Presenter: Rivera-Colon, Angel G.

Mentor: Papa, Riccardo

Title: Genomic architecture of dorsal hindwing eyespot number variation in the butterfly Bicyclus anynana

Authors: Angel G. Rivera-colón (Department of Biology, University of Puerto Rico-Rio Piedras), Antónia Monteiro (Department of Biological Sciences, National University of Singapore), Riccardo Papa (Department of Biology, University of Puerto Rico-Rio Piedras)

Abstract

Butterfly wing patterns provide excellent examples for integrative research at the interface of the genetics and development of phenotypic diversity, as they present complexity in the genetics underlying the formation of a wide variety of phenotypic traits. In the butterfly Bicyclus anynana, the wing pattern consists of marginal eyespots in the ventral and dorsal sides of fore and hind wings of both males and females. Previous studies have identified specific genes involved in eyespot development, but the genetic architecture underlying eyespot number variation is unknown. Thus, the objective of this study is to characterize the genetic basis of eyespot number variation using a wide genome approach utilizing RAD seq to determine genotype variation among individuals that exhibit different dorsal hindwing eyespots number phenotypes. Our results indicate that this trait appears to be polygenic, as we found 46 independent genetic regions displaying high genotype-to-phenotype association. Also, downstream targets involved in known eyespot development networks were observed to be highly associated: tok, known modulator of Dpp signaling; ImpE1, activated by EcR signaling; and ct regulated by Notch. This suggests that dorsal hindwing eyespot number variation in B. anynana is the result of modulation of the known genetic networks normally involved in eyespot development, giving insight on how variation can arise from complex developmental systems.

420

Life/Biological Sciences Presenter: Rivero, Rafael

Mentor: Betancur, Ricardo

Title: Divergence Time Estimation and the Phylogenetic Relationships of Extant and Extinct Lungfishes

Authors: Rafael A. Rivero (Universidad de Puerto Rico - Recinto de Rio Piedras), Dahiana Arcila (The George Washington University), Ricardo Betancur-r (Universidad de Puerto Rico - Recinto de Rio Piedras)

Abstract

Lungfish represent one of the most well-known yet enigmatic clades, with a long and diverse fossil record beginning in the Devonian and dwindling to six species in the present. Current knowledge is underpinned by a host of morphological studies, each mostly focusing on unique characters, fossils, and groups with only minor overlap. These studies also traditionally relied upon antiquated cladistic or phylogenetic analyses, the latter of which generally estimated divergence times based exclusively on the geologic record. Here, we offer a modern phylogenetic analysis and divergence time estimation of all the available morphological data found in these disparate studies over the last 30 years. The data were combined via a stepwise approach to form a "supermatrix" spanning the known fossil and extant lungfish, and divergence times were estimated through Bayesian analyses, using the geologic record to inform the prior probability distributions of fossil representatives of the clade. The results reveal the importance of using large matrices that are able to capture the range of extant and extinct diversity in phylogenetic analyses as well as the power of Bayesian methods for jointly estimating branching patterns and divergence times.

421

Life/Biological Sciences Presenter: Rullan, Jesie

Mentor: Rios Velazquez, Carlos

Title: Purple non-sulfur bacteria from aquatic environments in Puerto Rico and its potential for copper bioremediation

Authors: Jesie M. Rullan-cardec (University of Puerto Rico at Mayaguez), Carlos Rios-velazquez (University of Puerto Rico at Mayaguez)

Abstract

Purple Non-Sulfur Bacteria (PNSB) are members of the Proteobacteria that caught the attention of the scientific community due to its metabolic diversity. These microorganisms have the ability to adapt to fluctuations in oxygen levels and can use a great variety of carbon sources. These bacteria can growth as anoxic phototrophs under anaerobic conditions or as chemotrophs in the presence of oxygen. In addition to their metabolic diversity, these microorganisms are widely distributed in nature and had been isolated from pond water, marine environments, soils and extreme environments such as saline soda lakes and Antarctic microbial mats. The biotechnological potential of these microorganisms has being explored and several applications have been proposed like bioremediation of heavy metals. The main focus of this research is to explore copper (Cu) tolerance of PNSB from bromeliads and heliconias phytotelmata and water reservoirs from Puerto Rico. A total of 20 isolates of PNSB were inoculated in Rhodospirillaceae media with CuCl2 concentrations ranging from 0 to 0.52mM and were incubated under anaerobic conditions with light at approximately 32oC. The growth of the isolates on the broth was determined by turbidimetry. From the 20 PNSB tested, 13 were able to growth in the presence of Cu in the media and 8 of this isolates were able to growth in 0.52mM of Cu. Interestingly 7 of this 8 PNSB were isolated from the phytotelmata of bromeliads. According to 16SrDNA analysis four belong to the genus Rhodopseudomonas, one to Rhodocyclus, and two of the isolates may belong to new genus of PNSB. This research place bromeliads phytotelmata as a suitable microenvironment source for heavy metal resistant PNSB. These findings can be used in the development of methods for bioremediation of environments contaminated with heavy metals by this anoxic phototrophic bacterial group.

422

Life/Biological Sciences Presenter: Saxena, Manoj

Mentor: Griebenow, Kai

Title: Targeted Cytochrome C Delivery using the Transferrin-receptor

Authors: Manoj Saxena (University of Puerto Rico, Rio Piedras campus, Dept. Environmental Sciences), Shweta Sharma (University of Puerto Rico, Rio Piedras campus, Dept. Environmental Sciences), Arthur D. Tinoco (University of Puerto Rico, Rio Piedras campus, Department of Chemistry), Kai Griebenow (University of Puerto Rico, Rio Piedras campus, Department of Chemistry)

Abstract

Cytochrome c is a protein that resides loosely associated with the inner mitochondrial membrane. Its long recognized role is as a member of the mitochondrial electron transport chain to transfer an electron from complex III to complex IV. However, it also plays a significant role in the activation of apoptosis. In the event of certain types of cell injuries or stresses, cytochrome c is released from the mitochondria and activates the caspase cascade inducing apoptosis. Based on these observations, our lab and others have developed methods for the delivery of cytochrome c to cancer cells to induce apoptosis. Although the release of cytochrome c into the cytoplasm could trigger apoptosis in cancer cells, the efficient and selective delivery of cytochrome c to cancer cells still remains a major bottleneck in the cytochrome c based drug development. We propose a transferrin receptor (Tfr) mediated delivery of cytochrome c as an effective way to target cancer cells. Compared to healthy cells, the majority of cancer cells display higher levels of Tfr on their surfaces. On treatment with the proposed transferrin - cytochrome c conjugate, the cancer cells will preferentially uptake this conjugate via their transferrin receptors. Once delivered into the cells, this conjugate will be transported through the canonical transferrin transport system via acidic endosomes. This construct is designed in such a way that the cytochrome c-transferrin bond is an acid labile S-S bond which upon reaching endosome will dissociate leaving the cytochrome c free. The free cytochrome c could be further released into the cytoplasm via its co-expressed cell penetration peptide moiety triggering cell death.

423

Life/Biological Sciences Presenter: Sharma, Shweta

Mentor: Tinoco, Arthur

Title: Synergism of citrate and transferrin revealing Ti-Tf binding, transport and regulation

Authors: Shweta Sharma (University of Puerto Rico, Rio Piedras Campus, Department of Environmental Sciences), Manoj Saxena (University of Puerto Rico, Rio Piedras Campus, Department of Environmental Sciences), Arthur D. Tinoco (University of Puerto Rico, Rio Piedras Campus, Department of Chemistry)

Abstract

Humans are exposed to titanium(IV) through its presence in food, cosmetic additive and by implants degradation. Studies have shown that Ti concentration greater than 100µM shows cytotoxicity. However, the dominant soluble Ti(IV) species in blood exhibit no cytotoxicity even at 100 µM concentration. Serum Transferrin (sTf) and citrate are supposed to be responsible for maintaining nontoxic Ti(IV) speciation in the blood. Our X-ray structure of Ti(IV) bound sTf reveals the molecular details of Ti(IV) interaction with serum transferrin (sTf) where sTf binds Ti(IV) in an unusual open conformation with citrate as a synergistic anion. Cellular studies of Ti uptake in A549 cells show that contrary to some previous reports, open conformation of transferrin is capable of transporting Ti(IV) into cells. Our results provide the first glimpse into citrate-transferrin synergism in Ti(IV) transport and how citrate anion impact Ti speciation, providing an explanation for the failure of anticancer Ti drugs like titanocene dichloride in clinical trials.

Life/Biological Sciences Presenter: Soler-Cedeño, Omar

Mentor: Porter, James

Title: Fear Conditioning and Extinction Induce Plasticity of Ventral Hippocampus Synapses in the Medial Prefrontal Cortex

Authors: Omar Soler-cedeño (Basic Sciences Department, Ponce Research Institute , Ponce Health Sciences University, Ponce, PR), Orlando I. Torres-rodríguez (Department of Science and Technology, Interamerican University of Puerto Rico Ponce Campus, Ponce, PR), Lizette 424

Maldonado-laboy (Chemistry Department, Pontifical Catholic University of Puerto Rico Ponce Campus, Ponce, PR), Anixa Hernández (Basic Sciences Department, Ponce Research Institute , Ponce Health Sciences University, Ponce, PR), James T. Porter (Basic Sciences Department, Ponce Research Institute , Ponce Health Sciences University, Ponce, PR)

Abstract

Life/Biological Sciences Presenter: Torres Toledo, Fabiola

Mentor: Tossas, Adrianne

Title: Avian Community Composition In Guajataca State Forest

Authors: Fabiola B. Torres Toledo (University of Puerto Rico - Aguadilla), Adrianne G. Tossas, Ph.d. (University of Puerto Rico - Aguadilla) 425

Abstract

Bird populations of Guajataca State Forest in northwestern Puerto Rico have been monitored in order to assess long-term trends. Two hundred forty-nine point counts were conducted in spring from 2009 to 2015. A total of 26 species was recorded during that period, ranging from 13 species in 2012 to 20 species in 2015. The overall number of individuals detected per count did not varied significantly among years (average = 0.5). However, the average number of individuals detected per count of the five most common species, Puerto Rican Bullfinch (Loxigilla portoricensis), Black-whiskered Vireo (Vireo altiloquus), Puerto Rican Vireo (Vireo latimeri), Adelaide's Warbler (Dendroica adelaidae), and Bananaquit (Coereba flaveola), ranged from 2.4 to 2.9. Only slight changes were noted on average detections among years, probably due to annual differences in the onset of the singing/breeding behavior, and not related to real population fluctuations. While most species remained stable throughout the seven-year period, only one species, the Ruddy Quail-Dove (Geotrygon montana), showed a steady increase through time. This woodland species is highly sensitive to forest fragmentation, thus, its population increase can be an indicator of improving habitat quality. Moreover, the stable populations of 12 out of 17 insular endemic species suggest that resources in this natural reserve are adequate for sustaining this avian community.

Life/Biological Sciences Presenter: Torres-Alvarez, Victor N

Mentor: Hendricks, Timothy

Title: Genetic Programming of dI6 Neurons in vitro

Authors: Victor N. Torres-alvarez (Inter American University of Puerto Rico, Bayamon, Puerto Rico), Jose L. Roig (Universidad del Este, Carolina, Puerto Rico), Timothy Hendricks (Inter American University of Puerto Rico, Bayamon, Universidad Central del Caribe, Bayamon, Puerto Rico)

Abstract

A population of commissural inhibitory interneurons known as dI6 is an important component of the neural circuitry that drives locomotor rhythms in mammals. These interneurons migrate ventromedially after exiting the ventricular zone, settle into lamina VIII and IX, and integrate into the central pattern generator (CPG), which is responsible for generating the patterned motor output required for locomotion. While the function of dI6 interneurons remains incompletely understood, they have a strong influence on locomotor rhythms in both horses and mice. We have recently established an in vitro system to differentiate dI6 interneurons from mouse neural stem cells (NSCs) in order to study the molecular mechanisms governing the specification and differentiation of this cell type. We utilized a 426

recently identified dI6-specific marker, Wilms' Tumor Suppressor 1 (Wt1). In vivo Wt1 is expressed in early post-mitotic dI6 interneurons near the ventricular zone, at the dorsoventral midpoint of the neural tube. This gene, which encodes a zinc-finger transcription factor, is also expressed in kidney, epicardium and retinal ganglion cells where it plays an important developmental role in cell cycle regulation, survival and differentiation. In order to determine if Wt1 also plays a key role in the generation of dI6 interneurons, we performed ectopic expression in NSCs and in cells induced to differentiate into dI6 interneurons. For these studies NSCs derived from both wild-type and Wt1EGFP/+ E12.5 mouse embryos were used. In order to determine the functional effects of Wt1 overexpression, immunohistochemistry and qPCR against subtype-specific interneuron markers was performed to determine the number of dI6 interneurons generated. Currently, successfully transfected NSCs with the a specific Wt1 isoform (–KTS) showed presence of myc-tagged Wt1. Currently marker analysis is focused on the excitatory marker VGLUT2 and the inhibitory marker Gad65/67. Additionally non-dI6 interneurons have been identified by expression of Brn3A (dI5) and Pax2 (V0). This work will allow the construction of a working model for the functional role of Wt1 in the generation of dI6 interneurons.

Life/Biological Sciences Presenter: Torres-Alvarez, Victor N

Mentor: Hendricks, Timothy

Title: Genetic Programming of dI6 Neurons in vitro

Abstract

A population of commissural inhibitory interneurons (CIN's) known as dI6 is an important component of the neural circuitry that drives locomotion rhythms in mammals. These IN's migrate ventromedially after exiting the ventricular zone, settle into lamina VIII and IX, and integrate into the central pattern generator (CPG), which is responsible for generating the patterned motor output required for locomotion. While the function of dI6 CIN's remains incompletely understood, they have a strong influence on locomotor rhythms in both horses and mice. We have recently established an in vitro system to differentiate dI6 CIN's from mouse neural stem cells (NSC's) in order to study the molecular mechanisms governing the specification and differentiation of this cell type. We utilized a recently identified dI6-specific marker, Wilms' Tumor Suppressor 1(Wt1). In vivo Wt1 is expressed in early post- mitotic dI6 CIN's near the ventricular zone, at the dorsoventral midpoint of the neural tube. This gene encodes a zinc-finger transcription factor, it's expressed in kidney, epicardium and retinal ganglion cells, 427

where it plays an important developmental role in cell cycle regulation, survival and differentiation. Its multifunctionality resides in the fact that Wt1 can produce at least 24 isoforms, mainly due to lternative splicing. Here we address the functional role of Wt1 in the generation of dI6 CIN's. NSC's derived from spinal cord of both Wt1+/+ and Wt1+/eGFP embryos were transfected with isoform-specific constructs. Immunohistochemical (IHC) analysis was performed to determine the number of dI6 interneurons. Also, markers of neighboring types of cells will be used to study the possibility of transdifferentiation, including the excitatory interneuron marker VGLUT2, GAD65/67, which marks inhibitory interneurons, and Brn3A and Pax2, which marks dI5's and V0 interneurons, respectively. This work will allow the construction of a working model for the functional role of Wt1 in the generation of dI6 interneurons.

428

Mathematics

430

Mathematics Presenter: Dennis Aponte, Christian J.

Mentor: Marcano, Mariano

Title: Kidney Epithelial Cell: Mathematical Model and Cellular Homeostasis

Authors: Christian J. Dennis Aponte (University of Puerto Rico), Mariano Marcano (University of Puerto Rico)

Abstract

Maintaining an optimal cytosolic volume is critical for the epithelial cell viability. The control system that regulates the transcellular movement of water and ions is essential to avoid radical changes in the cytosol volume that could lead to the cell death. The exposition of the cell to hypertonic conditions will cause it to shrink; that because the water flux tends to move from a lower concentration to a higher concentration of solute. Similarly, if exposed to hypotonic conditions, the volume of the cell is going to increase. The body uses certain hormones to control the water and solute permeability in cells. One of these hormones is the aldosterone, which main objective is to regulate the absorption of Na+ and secretion of K+. Another of these hormones is the antidiuretic hormone (ADH). The ADH has among its main functions, water retention by increasing the reabsorption of water in the collecting duct and distal convoluted tubule of the kidney. The goal of this study is to identify the principal factors that could affect the homeostasis of the cell. To achieve this, a mathematical model is used to study the changes of the cytosolic volume and solute concentrations when the cell model is exposed to different abnormal conditions.

431

Mathematics Presenter: INNOCENT, Jean Keveny

Mentor: Pericchi, Luis

Title: Bayes Factors Consistency for Linear Models with Increasing Dimensions

Authors:

Abstract

The theory of priors has been proved as one of theories on the regression coefficient of the normal linear models for testing hypothesis and construct the model selection when proper priors are considered for the simpler null hypotheses in the computations of Bayes factors. On this ways, the intrinsic priors and the power expected-posterior (PEP) priors have been introduced and developed respectively by Berger and Pericchi (1996); and Fouskakis, Ntzoufras and Draper (2014) in Bayesian approach to study the consistency.

The consistency is one of important reasons that Berger and Pericchi (2001) discuss the advantage and motivation for using a Bayesian approach to the model comparison problem over the classical approach.

Consistency means that the true hypothesis need to be selected in the model comparison,which refers to use the observed data by assuming one of the competing models is true. Usually, consistency can be provided by Bayesian model comparison, which is one of various procedures and a natural approach that use the Bayes factor based on the posterior model probabilities.

In this paper, considering the intrinsic priors and Je reys power expected-posterior (JPEP) priors, we prove and analyze the Bayes factors consistency in the class of normal linear regression models, the first one established by Casella et al.(2009) and the other one by Fouskakis Ntzoufras and Draper (2014) , which are both depend on the sample size, the parameter space of the models or both. Particularly for nested models, we investigate and evaluate the consistency problem for Bayes factor of these two models, when the dimension of the reduced model is a fi xed non negative natural number and:

1) Dimension of the full model is a fixed constant.

2) the dimension of the full model dimensions p of the parameter space is so that n = rp ; r > 1; increases with the sample size n, and in fi rst the particular case where r = 2.

432

Physics 434

Physics Presenter: Bhattarai, Mohan

Mentor: Katiyar, Ram

Title: Structural and dielectric studies of Sc substituted lead zirconate titanate at the morphotropic phase boundary

Authors: Mohan K. Bhattarai (Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, PR 00936-), Shojan P. Pavunny (Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, PR 00936-), Alvaro Instan (Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, PR 00936-), Ram S. Katiyar (Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, PR 00936-)

Abstract

The simple PbZr1-xTixO3 (PZT), one of the most researched and technologically important perovskite oxides shows excellent properties in the vicinity of the morphotropic phase boundary (MPB) such as high dielectric constant and piezoelectric constant so that these materials are of importance to many applications such as ferroelectric memories, electronic resonators, electrostrictive actuators, sensors etc. The crystal structure, dielectric and other related physical properties such as Curie temperature, electrical conductivity, and ferroelectric coercitivity of PZT can be tuned by doping as well as by substituting isovalent or heterovalent ions into Pb and/or Zr/Ti sites. With this motivation a systematic study on structural, microstructural, dielectric, electrical and ferroelectric properties of scandium doped lead zirconate titanate electroceramics with the stoichiometric formula Pb0.90Sc0.10Zr0.53Ti0.47O3 (PSZT) and synthesized by high energy solid-state reaction method have been carried out. X-ray diffractometry was used to probe the phase purity and to derive the crystallographic parameters. Furthermore, structural phase transition was investigated by the damped harmonic oscillator modeling of the Raman spectra recorded in the temperature window of 80-570 K. The size (?2.1 micron), shape and distribution of grains were examined through a scanning electron microscope (SEM) and the sample was subjected to energy dispersive spectroscopy (EDS) for elemental analysis. A direct optical bandgap Eg of 3.42 eV was measured for the PSZT sample using diffuse re?ectance spectroscopy. The dielectric and electrical measurements were conducted on Pt/PSZT/Pt metal-ferroelectric-metal capacitors using impedance analyzer and electrometer, respectively, as a function of temperature (80-600 K) and frequency (102-106 Hz). At room temperature a high dielectric constant (?') ~237 and low tangent loss ~0.03 were measured and the dc current-voltage analysis suggests that, it obeys the interface limited Schottky charge transport. The remnant polarization and coercive field of the ferroelectric capacitors measured using Sawyer Tower test configuration were ~2.97 ?C/cm2 and ~12.98 kV/cm, respectively. 435

These results provide insights into fundamental physics and material science of the PSZT metal oxide and its potential application in the future electronic devices.

Physics Presenter: Escobar Veras, Samuel A.

Mentor: Morell, Gerardo

Title: SnO2/Graphene/Graphene Oxide composite as photo-catalyst for water treatment: NO3 abatement.

Authors: Samuel Escobar (Department of Physics, University of Puerto Rico - Rio Piedras.), Laura Méndez (Department of Anatomy & Neurobiology, University of Puerto Rico Medical Science), Frank Mendoza (Institute for Functional Nanomaterials, University of Puerto Rico - Rio Piedras), Salvador Guavalda (Department of Chemistry, University of Puerto Rico - Rio Piedras), Brad Weiner (Department of Chemistry, University of Puerto Rico - Rio Piedras), Gerardo Morell (Department of Physics, University of Puerto Rico - Rio Piedras.)

Abstract

Hereby we report the results on the reduction of nitrate (NO_3^-) due to the photocatalytic reaction with the semiconductor tin dioxide (SnO_2) incorporated within graphene/graphene oxide (G/GO) sheets. Such process is carry by exposing an aqueous nitrate solution containing the SnO2-G/GO composite to UV radiation (~365 nm). The G/GO template expands the surface-to-volume ratio interaction of SnO2 nanoparticles with the nitrate molecules, demonstrating an enhanced photocatalytic performance over bare SnO2. This enhancement is attributed to the avoidance of electron – hole pair recombination; due to the availability of lower energy states in the conduction band (CB) of the template (G/GO), which allows for photo generated electrons in the SnO2 CB to migrate to G/GO's owns. Results suggest that such properties are what allow this material to successfully reduce NO_3^-, providing a suitable route for the control on the attenuation of such compound; lessening its unfavorable effects on the environment and on ourselves.

436

Physics Presenter: Guzmán Olivos, Fernando A.

Mentor: Morell, Gerardo

Title: Amorphous carbon nanoflakes deposited by RF magnetron sputtering

Authors: Fernando Guzmán Olivos (Universidad de Chile), Rodrigo Espinoza González (Universidad de Chile)

Abstract

Properties of the amorphous carbon (a-C) films can be further controlled by inserting into the carbon film different chemical elements. Particularly, doping of the film by metals such as gold, silver, or copper results in additional benefits such as surface plasmon resonance effect, antibacterial surface properties as well as good hemocompatibility, increased wear resistance, and substantial reduction of the film residual stress. Carbon nanostructures were prepared by RF magnetron sputtering at deposition times from 30 to 120 min. and temperatures on silicon substrates from 390 °C to 510 °C. Scanning and transmission electron microscopy (TEM) observations showed that carbon films deposited at 510 ºC consisted of nanostructured polycrystalline carbon nanoflakes. Dark field TEM images showed carbon nanocrystals of 1 nm average size. The sp2 hybridization decreases with increasing deposition time, as it was confirmed by X-ray photoelectron spectroscopy. The nature of these carbon nanostructures would be turbostratics, an intermediate state between hexagonal and amorphous phases. Field emission properties of the films are also presented, for future semiconductors applications.

437

Physics Presenter: Limbu, Tej B.

Mentor: Morell, Gerardo

Title: Study on the Optical and Electrical Properties of Tetracyanoethylene Doped Bilayer Graphene Stack for Transparent Conducting Electrodes

Authors: Tej B. Limbu (Institute for Functional Nanomaterials, University of Puerto Rico), Frank Mendoza (Institute for Functional Nanomaterials, University of Puerto Rico), Danilo Barrionuevo (Department of Physics, University of Puerto Rico, Rio Piedras Campus), Jennifer Carpena (National Research Council, Washington D.C.), Brad R. Weiner (Department of Chemistry, University of Puerto Rico, Rio Piedras Campus,), Gerardo Morell (Department of Physics, University of Puerto Rico, Rio Piedras Campus)

Abstract

We report the optical and electrical properties of chemically-doped bilayer graphene stack by tetracyanoethylene (TCNE), a strong electron acceptor. Large area and uniform bilayer graphene was synthesized by hot filament chemical vapor deposition (HFCVD) with methane gas as the carbon precursor. The TCNE doping on the bilayer graphene via charge transfer was confirmed by Raman spectroscopy and Fourier transform spectroscopy (FTIR). Doped graphene shows a significant increase in the sheet carrier concentration of up to 1.5×1013 cm-2 with a concomitant reduction of the sheet resistance down to 414.1 ?/sq. The high optical transmittance (ca. 84%) in the visible region in combination with the low sheet resistance of the TCNE-doped bilayer graphene stack opens up the possibility of making transparent conducting electrodes for practical applications.