Student Research Poster Symposium

April 23, 2010 Villanova University

Sigma Xi Research Poster Symposium, April 23, 2010 This volume is also available electronically on the Sigma Xi chapter’s website,

Proceedings of the 2010 http://www.csc.villanova.edu/~sigmaxi/

Student Research Symposium

April 23, 2010 Villanova Room Villanova University Villanova, PA 19085 USA

Supported by: The Villanova Chapter of Sigma Xi, the Scientific Research Society

Sigma Xi Research Poster Symposium, April 23, 2010 Sigma Xi Research Poster Symposium, April 23, 2010 Welcome from the Poster Symposium Organizers Poster Judges Carol Ambruster Assistant Professor, Astronomy & Astrophysics Welcome to the 2010 Villanova University Sigma Xi’s Student Ronald Balsamo Associate Professor of Biology Research Poster Symposium! Sigma Xi is the international honor Anil Bamezai Associate Professor of Biology society for research scientists and engineers. The Villanova chapter of Mary E. Desmond Professor of Biology Sigma Xi is proud to sponsor this poster symposium event to Gang Feng Assistant Professor of Mechanical Engineering recognize and celebrate the research work accomplished by our Vijay Gehlot Associate Professor of Computer Science students, and to give students an opportunity to further develop their Don Goelman Associate Professor of Computer Science skills in communicating those accomplishments. Edward Guinan Professor of Astronomy and Astrophysics Vikram Iyengar Assistant Professor of Biology This book contains abstracts of 40 contributed posters. Many thanks Daniel Joyce Associate Professor of Computer Science to all students who contributed to this symposium. We gratefully Frank Klassner Associate Professor of Computer Science acknowledge the dedicated poster judges who committed to Adam Langley Research Assistant Professor of Biology evaluating the research posters and providing written feedback at the Edward Sion Professor of Astronomy and Astrophysics end of the symposium. Special thanks for their time and commitment John W. Ullrich Assistant Professor of Chemistry to promoting research at Villanova University. Ani Ural Assistant Professor of Mechanical Engineering Melanie Vile Research Assistant Professor of Biology Outstanding posters will be recognized in the form of poster awards. In Thomas Way Associate Professor of Computer Science keeping with recent tradition, the induction ceremony for new Sigma Xi James Wilson Assistant Professor of Biology members will follow the student award presentations.

Congratulations to all!

Phil Maurone Sigma Xi Chapter President Robert Styer Sigma Xi Chapter Past-President Mirela Damian Sigma Xi Chapter President-Elect Sridhar Santhanam Sigma Xi Chapter Secretary-Treasurer

Sigma Xi Research Poster Symposium, April 23, 2010 Sigma Xi Research Poster Symposium, April 23, 2010 Table of Contents Are Main Sequence K-type Stars the "Goldilocks" Stars for Hosting Long-term Habitable Planets? Astronomy and Astrophysics (9) Aaron V. WolfeUG, Edward F. Guinan, Kellie M. DatinUG, Laurence E. DeWarf and Scott G. Engle ……..9 40 Eridani: The Vulcan Sun as a Benchmark for the Evolutionary Properties of White Dwarfs and Cool Stars Biology (22) Ronald BallouzUG, Edward Guinan, Rick Wasatonic and Scott EngleG ……..1 The effect of diet and training on ketone body metabolism Surface activity analysis of the eclipsing binary in the muscles of the European Starling (Sturnus vulgaris) UG UG UV Leonis based on new spectrophotometric data Katherine Allport , John Olson and Patrick Kealey …….10 Kyle ConroyUG, Scott EngleG, Ronald BallouzUG, Andrej Prsa and Edward Guinan ……..2 Role of membrane rafts in apoptosis via a glycosylphosphatidyl-inositol anchored protein, Ly-6 The Night Time Sun: XMM-Newton X-Ray Philip BalzanoG and Anil Bamezai …….11 Observations of Solar Twin 18 Scorpii Jared CoughlinUG, Edward F. Guinan, Scott G. EngleG, Analysis of Fliz1 Contribution to Tumorigenesis in Larry E. DeWarf, J.C. Hall, J. DePasquale Mouse Mammary Tumor Virus-Infected Mice and R.R. Thompson ……..3 Amanda BernierUG and Janice Knepper …….12

Exposing the Sun's Exuberant Youth: A Multi-wavelength The use of a Brd2 antibody to understand the Study of the Young ZAMS Sun Analog HD 49855 role of the protein in Zebrafish development K.M. DatinUG, L.E. DeWarf, E.F. Guinan, Catharine ComstockUG and Angela DiBenedetto …….13 S.G. Engle and T. Mizusawa ……..4 The effect of mutations in unexplored Salmonella The Relationship Between Hα Emission and Age in M Stars regulatory genes on host cell interactions Vinicio DiazUG, Ronald Louis-Ballouz and Edward Guinan ……..5 Kathleen CrosbyUG and James W. Wilson …….14

Get a Clue with AI Hya and ZZ Boo Identification of amino acid residues critical for Brian KirkUG, Cindy VillamilUG, Andrej Prsa acid phosphatase activity in Candida glabrata and Edward Guinan ……..6 Danielle DaviesUG, Brianne OrkwisG , Christine Kerwin and Dennis Wykoff …….15 The Prototype Dwarf Nova SS Cygni: The White Dwarf Expose J. A. MyszkaUG, E. M. Sion and P. Godon ……..7 Quantification and Localization of Tmem170 Expression in Mouse Mammary Tumor Cells The Eclipsing Binary DI Herculis: One mystery solved, Edward GillUG and Janice Knepper …….16 but another takes its place Nicole ZimmermanUG, Edward Guinan and Frank Maloney ……..8

Sigma Xi Research Poster Symposium, April 23, 2009 1 Sigma Xi Research Poster Symposium, April 23, 2009 2 A systematic screen of a fission yeast deletion collection The dynamics of cell proliferation and death in the chick embryo for mutants defective in phosphate-starvation-regulated neuroepithelium acid phosphatase Courtney ShipmanUG and Mary Desmond …….27 Theresa HenryUG, Julie PowerUG, Christine Kerwin and Dennis Wykoff …….17 Eutrophication Alters Mangrove-Salt Marsh Community Competition Lorae' T SimpsonG and Samantha Chapman …….28 Effects of Fatty Acid Diet and Flight Training on Ketone Body Metabolism in Liver and Kidneys of European Starlings Analysis of the role of inflammatory pathways on estrogen-induced Patrick KealeyUG and John Olsen …….18 uterine tissue remodeling in the ovariectomized immature rat Shreya TrivediUG, Alec VishnevskyUG and Louise Russo …….29 Glial Cell Progression in the Developing Chick Neuroepithelium Julie LeberUG and Mary Desmond …….19 How does N Pollution Affect the Decomposition in a Brackish Marsh? G Le Wang and Adam Langley …….30 Neuronal Differentiation in the Developing Chick Embryo Brain Robert J MillsUG and Mary Desmond …….20 Hybrid chickadees show higher survival than Black-capped and Carolina chickadees in southeastern Pennsylvania Stephanie G. WrightG and Robert L. Curry …….31 Role of Membrane Rafts in CD4+ T Cells Sanya NawareUG and Anil Bameza …….21 Computer Science (6) Analysis of Specific Gene Deletions in Schizosaccharomyces pombe: Effects of Phosphate Starvation on Pho1 Processing and Pho7 Localization CPATH: Distributed Expertise - Collaborating with other Disciplines UG UG Lillian Cassel, Thomas Way, Kim Pearson, Deborah Tatar, Juliette Power , Theresa Henry , G G Steve Harrison and Sridhara Potluri …….32 Christine Kerwin and Dennis D. Wykoff …….22 ENSEMBLE: Enriching Communities and Collections to Support How does a western Canadian bog get its nitrogen? Education in Computing G Tatjana Prša and Melanie A. Vile …….23 Lillian Cassel, Ed Fox, Weiguo Fax, Richard Furuta, Frank Shipman, Dan Garcia, Lois Delcambre, A comparison of the effects of tamoxifen and 17b-estradiol Peter Brusilovsky, Greg Hislop and Sridhara PotluriG …….33 on tissue remodeling and inflammation in the ovariectomized rat uterus CSTA Source: A Web Repository of K-12 Computer Science UG Alexandra Rowan and Louise Russo …….24 Teaching and Learning Materials Bala Krishna ChitneniG and Lillian Cassel …….34 Characterization of the ydcI gene in Esherichia coli UG Ashka Shah and James W. Wilson …….25 The Computing Ontology and its Implications in Computing Education The effects of sea-level rise and species composition on Siva Kumar InguvaG, Lillian N Cassel and productivity and decomposition in a brackish marsh Sandeep N SreerambhatlaG …….35 UG Katherine A. Shepard and J. Adam Langely …….26

Sigma Xi Research Poster Symposium, April 23, 2009 3 Sigma Xi Research Poster Symposium, April 23, 2009 4 Colored Petri Nets Based Models of Economic Systems and Integration into an Asset Planning Tool 40 Eridani: The Vulcan Sun as a Benchmark for the Carmen NigroUG, Vijay Gehlot and Thomas Way …….36 Evolutionary Properties of White Dwarfs and Cool Stars An Efficient Routing Topology for Wireless Networks UG with Directional Antennas Ronald Ballouz , Edward Guinan, Rick Wasatonic and G Kristin RaudonisUG and Mirela Damian …….37 Scott Engle Department of Astronomy and Astrophysics, Villanova University

Mechanical Engineering (3) 40 Eridani is a bright nearby triple star system. 40 Eri A is a 4.4-mag K1 V star and its two more distant (~ 400 AU) companion stars, 40 Eri Blast Shield Protection B and 40 Eri C are a 9th mag DA4 white dwarf & an ~11th mag M4.5 G G Ledjan Qato , Devin Pellicone , Gerard Jones, star. 40 Eri A is well known (in science fiction circles) as the probable Sridhar Santhanam and Ed Dougherty …….38 host star to the planet Vulcan; however, 40 Eri is also only one of a handful of white dwarfs that has well-determine dynamical masses. Comparison of Silicon Nitride Nanowires synthesized Utilizing archival X-ray, ultraviolet (IUE) data, and Mg II HK emission by silica nanopowders and silica gel measures, we determined the properties of the system members. G Sanket Deshmukh , Kei-Peng Jen and Sridhar Santhanam …….39 Using calibrated age-rotation-activity relations developed by us and others, we determine an age of ~5.2+/-1.2 Gyr for 40 Eri A (and thus Mechanical Characterization of the Cement Line in the system). This age is in good agreement with the age estimated Multi-Species Femur Bone through Nanoindentation from white dwarf component of ~ 5.0+/-1 Gyr [main-sequence + Timothy MontalbanoG and Gang Feng …….40 cooling time (0.1Gyr)]. The accurate age, evolution, and mass of the hot white dwarf star provide a firm benchmark for calibrating ages/cooling times of lower mass white dwarfs. The implications of this new age determination on the evolution & cooling times of low mass white dwarfs and cosmochronology are discussed.

Sigma Xi Research Poster Symposium, April 23, 2009 1 Sigma Xi Research Poster Symposium, April 23, 2009 5 Surface activity analysis of the eclipsing binary UV The Night Time Sun: XMM-Newton X-Ray Leonis based on new spectrophotometric data Observations of Solar Twin 18 Scorpii Kyle ConroyUG, Scott EngleG, Ronald BallouzUG, Andrej Jared CoughlinUG, Edward F. Guinan, Scott G. EngleG, Prsa and Edward Guinan Larry E. DeWarf, J.C. Hall1, J. DePasquale2 and R.R. Department of Astronomy and Astrophysics, Villanova University Thompson2 Department of Astronomy and Astrophysics, Villanova University 1Lowell Observatory, CfA, 2Orbital Science Corporation SOFIA UV Leonis is an eclipsing binary system consisting of two type G stars Telescope with a period of ~0.6 days. Evidence has been found of a period change in 1980, as previously reported by Wunder (1995) and Snyder (1998), but the exact nature and cause is still debatable. Stellar The nearby bright G2V star 18 Scorpii has been considered the best activity models have been explored by Frederik and Etzel (1996) but solar twin, being a near-perfect match to our Sun in all physical should be reexamined in light of more recent observations. characteristics. 18 Sco has a rotation period of PRot=22.7±0.5 d, Additional spectroscopic and photometric data were acquired by which is very close to the Sun's. CaII H&K observations indicate a Kjurkchieva and Marchev (2007) but stellar activity was not analyzed. possible ~7-11yr. activity cycle. Until our X-ray observations with In an attempt to gain better insight into the period change and stellar XMM-Newton in Aug 2005, 18 Sco had never been observed in this activity, we have obtained forty nights of photometric data from the spectral region. The analysis of these measurements yield an X-ray 30” Automated Photoelectric Telescope in Patagonia, Arizona and luminosity and coronal plasma temperature of L =8±1.5ergs/s and have used echelle spectra from the 1.8m Mt. Ekar telescope in X Asiago, Italy. We propose a stellar activity model with two spots TCorona~1.5-2 MK. These data were taken near maximum magnetic about the same size as in the previous model, but with spot-to- activity. This observed value falls within the solar range LX~6- photosphere temperature ratios of about 0.95 instead of ~0.8. As 30ergs/s; TCorona~2 MK. Interferometric angular radius measured opposed to two polar spots, our model consists of two migrating with the PTI yield a radius of 0.975±0.162 R/RSun. Evolution models equatorial spots on the primary star. indicate a Mass=0.98±0.05 MSun and an age of 4-5 Gyr. These observations demonstrate that 18 Sco is a bonafide solar twin through the X-ray portion of the spectrum. This distinction makes is a very important star to use as a proxy “Night Time” Sun for standardization purposes, an excellent candidate for asteroseismic studies, and as a target for searches for life-bearing terrestrial planets.

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Exposing the Sun's Exuberant Youth: A Multi- The Relationship Between Hα Emission and Age in M wavelength Study of the Young ZAMS Sun Analog HD Stars 49855 UG UG Vinicio Diaz , Ronald Louis-Ballouz and Edward Guinan K.M. Datin , L.E. DeWarf, E.F. Guinan, S.G. Engle and Department of Astronomy and Astrophysics, Villanova University 1 T. Mizusawa Department of Astronomy and Astrophysics, Villanova University 1IPAC/NStED/Caltech Through analyzing the Hα wavelength emission lines from dwarf M stars, we will extrapolate a relationship between the strength of these emission lines and the age of the stars. Observable data shows that Over the last several years we have been carrying out a study of Hα emissions decrease as the star ages. By measuring the stellar magnetic activity and dynamos, atmospheric physics, and X- chromospheric activity of these stars (which is tied to the strength of UV spectral irradiances from a sample of G0-5 V stars with different spectra emission), we have made correlation between the strength of ages. One of the major goals of this program is to study the change the chromospheric activity and the age of M dwarfs. To find this in rotation with time for solar-type stars, measuring the spin down of relation, we are using dwarf M stars with known ages and observed G-type stars as they age through the main sequence. Of particular Hα emissions in order to find an accurate age-activity relation. By interest in this study is the physical parameters and magnetic activity mining online astronomical databases, as well as our own recent of zero age main sequence (ZAMS) solar twins, because it allows a observations, we have measured the Hα emission M dwarfs. rare look into our own Sun's distant past shortly after planet formation. Furthermore, we have resolved the age-activity relationship by binning The young ZAMS Sun was spinning rapidly and consequently the spectral classification of M-dwarfs, into 5 subgroups. This allows possessed a vigorous magnetic dynamo that resulted in intense for a more accurate analysis and more precise age-activity corona X-ray and chromospheric UV emissions. The focus of this relationships. It is our hope that our research will set the groundwork study is on the 8th mag G5 V star HD49855. As a member of the for using Hα emissions to determine the ages of Stars of other Tuc/HorA association, HD49855 is only ~30 Myr, providing a near spectral classifications. perfect ZAMS analog for the Sun. Photometric, spectroscopic, and parallax measures yield: L/L⊙ ≈ 0.7, R/R⊙ ≈ 0.9 and Teff ≈ 5650K -- very close to what are expected for the properties of 1M⊙ ZAMS age Sun. Utilizing available All-Sky Automated Survey (ASAS) photometry, we were able to determine the rotation period (3.83 ± 0.02 days), and investigate the magnetic activity of this young star (starspot coverage, X-ray/FUV emissions). This young star is an important analog for investigating planet formation and remnant debris disk properties for young solar stars and the young Sun.

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The Prototype Dwarf Nova SS Cygni: The White Get a Clue with AI Hya and ZZ Boo Dwarf Expose UG UG Brian Kirk , Cindy Villamil , Andrej Prsa and Edward J. A. MyszkaUG, E. M. Sion and P. Godon Guinan Department of Astronomy and Astrophysics, Villanova University Department of Astronomy and Astrophysics, Villanova University

We have carried out a combined Hubble Space Telescope and FUSE An eclipsing binary is a binary system in which the orbit plane of the FUV spectroscopic analysis of the prototype dwarf nova SS Cygni two stars is aligned in the line of sight of the observer so that the stars during quiescence. The FUSE and HST spectra were obtained at undergo mutual eclipses. Because a large proportion of stars exist in comparable times after outburst and have matching flux levels where binary systems, binaries are particularly important to our in the overlapping region. In our synthetic spectral analysis, we have understanding of the processes by which stars form. If light curves used SS Cygni's accurate HST FGS parallax, d = 166 pc, a newly and spectroscopic data are acquired, eclipsing binaries provide determined mass for the accreting white dwarf (Bitner, Robinson, & astrophysicists with the orbital and physical parameters of the binary; Behr, 2007) of M_wd= 0.81 Msun (lower than the previous 1.2 Msun) distance, projection, system velocity, inclination, mass, luminosities, and widely adopted reddening of E(B-V) = 0.04. Our best-fit model temperature ratios, radii, period, and changes in period (Green, 2004). solution to the combined HST + FUSE spectral energy distribution Furthermore it has been demonstrated that eclipsing binaries are consists of a hot white dwarf with T_eff= 50,000K, log g = 8.5 with a excellent distance indicators, permitting the calibration of the cosmic solar composition accreted atmosphere. Accretion disk models distance scale essentially free from many assumptions and matching a distance of 166 pc fit badly in the FUSE range while, if the uncertainties plaguing other less direct methods (Bonanos, 2006). distance is a free parameter, the only accretion disk model which fits Eclipsing binaries have incredible potential for scientific discovery as well is for a distance of 600-800 pc and the accretion rate (10^-8 they are the only astrophysical objects where these properties can be Msun/yr!) is unacceptably high for a dwarf nova in quiescence. We directly determined. AI Hya and ZZ Boo, a pair of unique eclipsing discuss the implications of the white dwarf temperature on the time- binaries, yield these parameters which are used to calibrate our averaged accretion rate and long term compressional heating models. current evolutionary models. These observations give physical confirmation of our theories and allow us to resolve a mass-luminosity relationship from which the masses of single stars can be estimated.

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The Eclipsing Binary DI Herculis: One mystery Are Main Sequence K-type Stars the "Goldilocks" solved, but another takes its place Stars for Hosting Long-term Habitable Planets? Nicole ZimmermanUG, Edward Guinan and Frank Maloney Aaron V. WolfeUG, Edward F. Guinan, Kellie M. DatinUG, Department of Astronomy and Astrophysics, Villanova University Laurence E. DeWarf and Scott G. Engle Department of Astronomy and Astrophysics, Villanova University The 8th-mag eclipsing binary DI Herculis has perplexed scientists for the past few decades due to its anomalously slow apsidal motion rate. DI Her consists of two main-sequence stars (B5V, B6V), with P(orb) = As an extension of the Villanova “Sun in Time” program, we have 10.55 days, and eccentricity(e= 0.489). Since the apsidal motion is been studying the suitability of dK stars as hosts to habitable planets. dominated by General Relativity, the system is one of the few tests To this end we have measured the coronal X-ray and chromospheric available for verifying the theory. Combining the expected classical (1. emissions of dK0-8 stars with wide ranges of age, rotation, and °93/100 yr) and relativistic (2. °34/100 yr) effects, the predicted magnetic-dynamo-generated coronal and chromospheric X-UV apsidal motion rate is 4. °27/100 yr. Our recent determination of the activity. We have established well defined age-rotation-activity apsidal motion yields 1. °33±0. 25 /100 yr, based on eclipse timings relations for this sample. We have used archival X-ray (mostly from 1936-2008. Recently, Albrecht et al (2009) have apparently ROSAT) and UV data (from FUSE and IUE). The rotation periods solved the apsidal motion anomaly of DI Her, finding that the axes of were determined using photometry from star spot modulations. both stars are significantly inclined from the normal to the orbital Although their optical luminosities remain essentially fixed up to ~10+ plane. This was determined from the radial velocity curves and Gyrs, the magnetic dynamo X-UV radiances decay rapidly with age. observing the Rossiter-McLaughlin effect during primary and Young dK stars rotate rapidly and have correspondingly strong secondary eclipses. Having significantly misaligned axes of rotation magnetic dynamos and strong coronal X-ray and chromospheric UV produces a perturbation that greatly reduces the classical apsidal emissions (as well as frequent flaring). Here we discuss the suitability motion effect, thus explaining the observed small apsidal motion rate. of dK stars as hosts for life supporting planets where long-term life is Even though this discovery apparently solves the problem, it raises sustainable and compare them with properties planets hosted by G new questions as to how the axes are so tilted. Additionally, tilted and M-type stars. From this study we conclude that these orange axes are expected to contribute to other orbital effects, such as dwarf stars may be the best choices for hosting planets with evolved, changes in orbital inclination, which have not yet observed from the complex life. apparent constancy in eclipse depths over time. We have also searched for evidence of small periodic oscillations in the eclipse timings and found no evidence of a light travel time effect arising from a possible tertiary component. Further, we find evidence that the projected rotation axes of the stars may be precessing, since it appears that the value of vrot sin i has increased over the past 30 years.

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The effect of diet and training on ketone body Role of membrane rafts in apoptosis via a metabolism in the muscles of the European Starling glycosylphosphatidyl-inositol anchored protein, Ly-6 (Sturnus vulgaris) G Philip Balzano and Anil Bamezai UG Katherine Allport , John Olson and Patrick KealeyUG Department of Biology, Villanova University Department of Biology, Villanova University The surface of a cell is not homogenous; there are regions and Migratory birds are capable of performing long-distance flights with domains scattered across the membrane known as lipid rafts whose little food intake, relying heavily on nutrient stores enriched in high- lipid composition is different from that of the rest of the membrane energy fatty acids. One consequence of fatty acid use is the bilayer. Lipid rafts are more densely packed than the rest of the production of water-soluble ketone bodies. For this project, 60 young bilayer, but float freely around it. Lipid rafts perform a key role in European Starlings (Sturnus vulgaris) were caught in the wild. 30 signal transduction for the cell, possibly by clustering together to serve birds were placed on a polyunsaturated fatty acid (PUFA) diet and 30 as a formation point for signaling proteins on both sides of the birds were placed on a monounsaturated fatty acid (MUFA) diet. membrane. One such signaling pathway lipid rafts may be a part of is Birds from both diets were placed on a training regimen and flown for the apoptosis, or signaled cell suicide, pathway. One outcome of increasingly long individual flights in a wind tunnel. Birds from both engaging GPI-anchored proteins on T cells is their growth inhibition diets were also left untrained and tissue samples were collected. Key and cell death; it is not yet entirely clear whether the enzymes associated with ketone body metabolism (oxoacid-CoA glycosylphosphatidyl-inositol (GPI) anchor signaling protein involved transferase and HMG-CoA synthase) were assayed in four in the apoptosis pathway uses lipid rafts to help carry the death signal experimental groups (trained-PUFA, untrained-PUFA, trained-MUFA, along. I hypothesize that by disabling the lipid rafts on a population of and untrained-MUFA). It is hypothesized that birds fed a PUFA diet target cells, apoptosis will not be able to proceed when the proper will have a higher capacity for ketone body metabolism in the heart signals are given. Thusly, the percentage of dead cells in a population and pectoralis compared to the birds fed a MUFA diet. The effect of with its lipid rafts disabled will be significantly lower than a population diet and training on these capacities will be more pronounced in left untreated. Data indicates that stimulation with anti-Ly-6 antibodies trained birds. The results of this study will contribute to knowledge induces cell death by apoptosis that is dependant on the about the effect of diet and training on substrate use in migrant concentration of antibody. Disruption of the lipid rafts does not prevent passerine birds. apoptosis, indicating that lipid rafts are not involved in cell death via the GPI-anchored protein Ly-6. Future experiments will contend with which pathway, possibly the Fas-dependant pathway, Ly-6 is using to induce apoptosis.

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The use of a Brd2 antibody to understand the role of Analysis of Fliz1 Contribution to Tumorigenesis in the protein in Zebrafish development Mouse Mammary Tumor Virus-Infected Mice Catharine ComstockUG and Angela DiBenedetto UG Amanda Bernier and Janice Knepper Department of Biology, Villanova University Department of Biology, Villanova University

Mouse mammary tumor virus (MMTV) is a retrovirus that integrates The Brd2 gene is part of a Bromodomain and Extraterminal doman randomly into the mouse genome. It causes tumorigenesis when it (BET) containing family of genes that is conserved in species from integrates adjacent to and activates a protooncogene in the mammary Drosophila, zebrafish, mice and humans. The conserved gland. In the Knepper lab, overexpression of Fliz1 in cV1a 03-31 bromodomain associates with acetyl-lysine histones and acts as a tumor cells was observed. Fetal liver zinc finger protein 1, the product scaffold in recruiting other transcription factors to promoters of genes of Fliz1, has been shown to bind the regulatory region of GATA-3 and implicated in mitosis and apoptosis. Developing zebrafish have repress promoter activity. Low GATA-3 levels correlate with low enriched brd2 mRNAs in the central nervous system and embryos estrogen receptor (ER) levels. Tumors with low ER levels will not deficient of brd2, MO1 (knockdowns) have shown extensive respond to Tamoxifen, a selective estrogen receptor modulator used morphological defects in the brain at 24hpf. Zebrafish are a useful to treat breast cancers because of its anti-estrogenic activity. genetic model system to study development because they are Experiments to test the role of Fliz1 and GATA-3 in tumor cells with transparent and are easy to breed, collect embryos and knockdown Fliz1 overexpression were conducted. Fliz1 knockout cell lines were the gene of interest. This study focuses on tracking and identifying generated. Mice were injected with normal 03-31 tumor cells and Fliz1 the localization pattern of the brd2 protein in developmentally staged knockout cells. The mice were treated with Tamoxifen at a dose rate and fixed zebrafish embryos using immunohistochemistry and equivalent to a human therapeutic dose. Growth was observed by western blotting. The protein is the true functional member in vivo measuring the tumors with external calipers. Tumors that developed and while the pattern of mRNA in zebrafish has been identified, from Fliz1 knockout cells are expected to have high GATA-3 levels, protein localization is critical to understand because it may not solely high ER levels, and respond to Tamoxifen. Tumors with Fliz1 mimic mRNA expression. In addition, this study will determine the overexpression are expected to exhibit little responsiveness to effectiveness of the MO1 knockdown zebrafish by comparing wild Tamoxifen. type and MO1 knockdowns side by side to detect presence of brd2 at different stages.

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Identification of amino acid residues critical for acid The effect of mutations in unexplored Salmonella phosphatase activity in Candida glabrata regulatory genes on host cell interactions UG G Kathleen CrosbyUG and James W. Wilson Danielle Davies , Brianne Orkwis , Christine Kerwin Department of Biology, Villanova University and Dennis Wykoff Department of Biology, Villanova University

A low fluid shear growth environment, as obtained in a rotating wall vessel (RWV) and in space flight, increases the virulence of The evolution of signal transduction pathways in single-cell organisms Salmonella typhimurium, the bacterium identified for causing is critical for survival in changing environments. Most organisms gastroenteritis. The increased virulence induced by these growth cues developed responses to phosphate starvation, a selective pressure, to may have important consequences for Salmonella growing in the low ensure survival. When phosphate is scarce the phosphate signal fluid shear environment between brush border microvilli in epithelial transduction pathway in yeasts leads to the secretion of phosphatase cells. Previous research has indicated altered expression of 163 which makes phosphate available by cleaving it from organic sources. Salmonella genes in the RWV and spaceflight, including genes with This pathway is well-characterized in Saccharomyces cerevisiae, but homology to transcriptional regulators. Due to the possible wide there is no PHO5 (phosphatase) ortholog in Candida glabrata. spread effects of transcriptional regulators on genome function, these Utilizing a genomic library of C. glabrata, three similar genes genes have been targeted as sites to introduce mutations. In this (CgPMU1, CgPMU2, and CgPMU3) were identified as potential acid study, we used P22 phage transduction in order to construct a strain phosphatases. PMU1, PMU2, and PMU3 have 70-80% amino acid containing mutations in a group of seven targeted genes. Mutations identity; deletion of each gene indicates PMU2 is the major acid were verified using PCR and combined to form strains with various phosphatase. The similarity of these three genes along with the mutations in a “one-by-one” process. So far, we have constructed presence of PMU1 across many different yeast genomes indicates a strains with two, three, four, and five mutations. Future work will duplication event followed by neofunctionalization may be responsible involve testing the invasion of these mutant strains into epithelial for evolution of the major acid phosphatase in C. glabrata. The goal of tissue culture cells. The invasion effects of these mutants will provide my thesis is to analyze the differences between PMU1 and PMU2 by insight into the virulence strategies of Salmonella and reveal possible identifying the amino acids that are responsible for the enzymatic new targets for drug and vaccine design. activity of the phosphatase through fusion of genes and mutagenesis of specific amino acids. These results along with characterization of mutagenized gene products will further the understanding of inter- and intra- species molecular evolution and neofunctionalization.

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Quantification and Localization of Tmem170 A systematic screen of a fission yeast deletion Expression in Mouse Mammary Tumor Cells collection for mutants defective in phosphate- UG starvation-regulated acid phosphatase Edward Gill and Janice Knepper Department of Biology, Villanova University Theresa HenryUG, Julie PowerUG, Christine Kerwin and Dennis Wykoff Department of Biology, Villanova University Mouse Mammary Tumor Virus (MMTV) is a retrovirus responsible for the production of a majority of tumors appearing in the mammary glands of mice. The integration of the pro-viral DNA sequence into During inorganic phosphate starvation, the phosphate-responsive the host genome of a mammary epithelial stem cell may lead to signal transduction (PHO) pathway in Schizosaccharomyces pombe altered expression of genes in close proximity. When the gene in induces transcription of genes that allow yeast cells to survive close proximity to the integration site encodes a protein pivotal to the starvation. One of these induced genes, PHO1, encodes a process of cell growth, the amplification of this gene's expression by phosphatase which accesses alternative forms of environmental the MMTV enhancer region results in a mammary carcinoma. In the phosphate. While the PHO pathway has been characterized in Knepper Lab, researchers identified in three separate cell lines a Saccharomyces cerevisiae, S.cerevisiae and S.pombe diverged over common site of MMTV integration on chromosome 8, and a potential 500MYA, and the components of the two species' PHO pathways oncogene in close proximity to this site labeled Gene Adjacent to Viral differ. Utilizing an S. pombe genomic deletion library, we identified 34 Insertion Site (GAV) was identified to be overexpressed through strains defective in their phosphate starvation response. The goal of integration of MMTV. Amino acid sequence analysis of GAV suggests my thesis was to analyze these mutants and identify key components it encodes a transmembrane protein, a family of proteins that function of the PHO pathway in S. pombe. Using p-nitrophenylphosphatase as receptors and intermediates in signal transduction pathways. (PNPP) assays, I measured acid phosphatase activity for each strain. Although evidence strongly suggests Tmem170 plays a major role in 26 mutants are unable to induce secreted acid phosphatase, while 8 tumorigenesis, the protein's function is still largely unknown. To mutants constitutively secrete phosphatase. I performed rt-qPCR and provide insight into Tmem170's function in tumorigenesis, we aim to epistatic tests on the strains to help determine regulation of the PHO both quantify Tmem170 expression and localize the protein within the pathway. I identified a zinc finger domain-containing protein that is cell. likely to be the main transcription factor for the phosphatase in S. pombe. The epistatic tests and assays have revealed other possible regulators of the PHO pathway. Together, my data suggest a potential framework for the PHO pathway of S. pombe.

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Effects of Fatty Acid Diet and Flight Training on Ketone Body Metabolism in Liver and Kidneys of Glial Cell Progression in the Developing Chick European Starlings Neuroepithelium UG Patrick Kealey and John Olsen Julie LeberUG and Mary Desmond Department of Biology, Villanova University Department of Biology, Villanova University

Migratory birds use fats as their main source of energy over long Embryonic chick development occurs in stages that are defined by the distance flights. Fats have different types of compositions, namely presence of morphological features, from 1 (conception) to 46 (hatch). monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids Brain growth occurs with stage progression, and the composition of (PUFA). Each has different energetic properties and even have tissue in each brain region throughout development is currently being different effects on membrane fluidity and fatty acid mobilization. This explored. A recent study of stages 21 through 30 showed that the leads to different activity levels of select enzymes, namely the presence of mature (fully differentiated) neurons appears to increase enzymes involved in ketone body catabolism and metabolism. with stage progression as the number of immature neurons Training is also believed to have a profound effect on enzyme activity decreases. This study's focus is on the presence of glial cells, for levels. This study is aiming to test the effects of different fatty acid these cells play a principal role in the activity of neurons. To test compositions as well as the effects of training on the enzyme activity whether glial cells showed a developmental trend related to that of levels of oxoacid CoA transferase as well as HMG CoA synthase in neurons, brain tissue from chick embryos at selected stages was the liver and kidneys of migratory birds. It is believed that HMG CoA stained for the presence of glial cells using Glial Fibrillary Acidic synthase levels will be higher in flight trained birds, as well as in Protein (GFAP). This revealed the number of glial cells present in MUFA fed birds. The study organism in this experiment was the each stage, and allowed regional differences in each stage to be European Starling (Sturnus Vulgaris). Enzyme levels were measured assessed. Stages included in this study were 21, 23, 25, 28, 30, 32, using a plate reader and analyzed using a two way ANOVA. Results 34, 36, and 38. and conclusions are pending.

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Neuronal Differentiation in the Developing Chick Role of Membrane Rafts in CD4+ T Cells Embryo Brain UG Sanya Naware and Anil Bamezai Robert J MillsUG and Mary Desmond Department of Biology, Villanova University Department of Biology, Villanova University

As specialized domains in the cell membrane, membrane rafts are Chick embryos are used as a model organism when studying thought to perform many essential functions in cell signaling, vertebrate brain growth because they are analogous to human brain endocytosis and exocytosis. Membrane rafts coalesce at the site of during development. The brain is unique because it is comprised of activation in T lymphocytes in response to the activation of T cell tissue and cavity. A crucial time in this development occurs when the receptors through the interaction of membrane bound proteins with tissue becomes greater than the cavity. During this, cell proliferation the actin cytoskeleton. The hypothesis raft structure proposes that and differentiation are increased due to various factors and pressure rafts are “liquid ordered” phases which have a tighter packing density caused by the cerebrospinal fluid (CSF). During proliferation, neuronal and stability because of the high levels of cholesterol, differentiation is prevalent and neurons are in various stages of glycosylphosphatidyl-inositol anchored proteins, and sphingolipids. development at different times. My project looks to determine the volume of neurons at these times in development at various stages of The purpose of this research is to better characterize the functional development. There are three stages of neurons, defined by the role of membrane raft coalescence in the signal pathway of T cell presence of an axon. This study used later chick stages. Each stage activation and proliferation. Oxysterol 7-ketocholesterol (7-KC) was studied to determine the presence of neurons. I hypothesize that prevents the formation of membrane rafts by causing disorder in the all stages will contain neurons at all stages of development. I believe rafts because the ketone on the seventh carbon disrupts the tight that the relative amounts will vary, with early neurons being prevalent packing which characterizes the rafts. Disruption of membrane rafts in the earlier stages and later neurons being prevalent in the later by the 7-ketocholesterol will provide evidence that membrane rafts stages. To detect neuronal differentiation, specific antibodies were play a significant role in T cell activation and proliferation. introduced. Nestin was used to detect early neuronal differentiation, while beta-III-tubulin detected middle stage neurons, and neuroD1 detected late neurons.

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How does a western Canadian bog get its nitrogen? Analysis of Specific Gene Deletions in G Tatjana Prša and Melanie A. Vile Schizosaccharomyces pombe: Effects of Phosphate Department of Biology, Villanova University Starvation on Pho1 Processing and Pho7 Localization Juliette PowerUG, Theresa HenryUG, Christine KerwinG Bogs are moss-dominated, ombrotrophic peatlands in which N and other nutrients enter via atmospheric wet/dry deposition. The only and Dennis D. Wykoff other potential input of N is through a microbially-driven process of N2- Department of Biology, Villanova University fixation. Until recently, N2-fixation in boreal regions has been thought to be of low importance. Several studies focusing on N2-fixation in moss carpets from western European boreal forests, however, When conditions do not provide substantial phosphate (PO4), yeast reported much greater N2-fixation rates than previously determined. activates the Phosphate Signal Transduction Pathway (PHO) to Therefore, N2-fixation may be an especially important and overlooked survive. The PHO pathway in Schizosaccharomyces pombe is input of N into bogs in western Canada. Due to exponential growth of relatively undefined but does have a phosphatase encoded by PHO1 the Oil Sands Mining in Alberta Canada, more N will be deposited -1 -1 that is upregulated during PO4 starvation, so that PO4 is cleaved from onto historically pristine bogs (inputs less than 1 kg ha yr ). The extracellular molecules. To provide insight into the effects of individual objective of this study was to examine current N atmospheric genes in PO4 starved environments, a deletion library was obtained deposition rates in bogs near pollution and to determine presence of with knockouts whose yeast open reading frame (ORF) were replaced N2-fixation in different mosses. I used ion exchange resin columns to with Kanamycin (KAN). Deletion with KAN was confirmed for each determine N inputs in bogs near Oil Sands industry and compare strain by PCR with primers designed to amplify only in the presence of them to a pristine bog. I also measured N2-fixation rates in different each of the genes. Therefore, when a gene knockout occurred, no moss communities in summer 2009 using acetylene reduction assay. Despite current atmospheric N deposition rates not exceeding 1 kg amplification of gene product was obtained. After gene deletion was -1 -1 confirmed, linkage of these deletions to the PHO pathway was ha yr , my preliminary results suggest that N2-fixation is an important analyzed in mating the mutant strain with a wild-type strain. N input. Phosphatase assays were then performed to determine if secretion of Pho1, and subsequent extracellular PO4 cleavage, was inhibited. Pho7, a suspected Pho1 transcription factor, was tagged with Yellow Fluorescent Protein (YFP) and stained with DAPI to demonstrate that Pho7 is localized in the nucleus regardless of PO4 concentration.

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A comparison of the effects of tamoxifen and 17b- Characterization of the ydcI gene in Esherichia coli estradiol on tissue remodeling and inflammation in UG Ashka Shah and James W. Wilson the ovariectomized rat uterus Department of Biology, Villanova University Alexandra RowanUG and Louise Russo Department of Biology, Villanova University The virulence of Salmonella typhimurium is significantly increased during growth in environments of low fluid shear force (approx. less Selective estrogen receptor modulators (SERMS) are chemical than 1 dyne/cm2) such as spaceflight and ground-based low shear agents that bind to the estrogen receptor (ER) and induce mixed culture models. Certain niches in the human body may serve to agonist and antagonistic responses. An mixed effect SERM, generate similar signals that modulate the virulence of pathogens. tamoxifen (Tam) was developed as a therapeutic agent to treat Previous studies have identified a stimulon of S. typhimurium genes women with ER-positive breast cancer. In breast tissue, Tam binds to that are differentially-regulated in response to growth in low fluid shear the ER and blocks the potential growth stimulating effects of estrogen. force environments. The analysis of these genes will reveal important However, it has been found that in the uterus, Tam is an estrogen clues about the nature of the response of bacteria to low fluid shear agonist and induces hypertrophy in the uterine lining. The pathway in environments. The gene ydcI is a member of this stimulon and is which Tam mimics estrogen's pathway in the uterus is poorly conserved in a range of gram negative bacteria. Studies in S. characterized. The focus of my thesis is to examine the effects of Tam typhimurium have found ydcI to be an important regulator of full on uterine biology using the ovariectomized (OVX) immature rat. resistance to acid stress. However, no data about the function of ydcI Previously, in the Russo laboratory, Tam and estrogen have been has been obtained in any other Gram negative bacteria. I have found to induce an increase in endometrial volumes and luminal cell constructed a ydcI deletion in the Gram negative bacterial Escherichia proliferation and height in the OVX immature rat. the lab also coli genome and have compared the survival of this mutant under established estrogen's upregulation of MMPs 2, 3, 7, 9, and various stresses to the isogenic wild type strain. Future research is inflammation markers, TNF-α and MCP-1. My first experimental aim aimed at determining if the E. coli ydcI gene controls other aspects of is to identify any upregulation of MMP mRNA by Tam. My second aim the biology of this species. is to establish whether or not Tam plays a role in the recruitment of TNF-α and MCP-1. In order to assess the effects of Tam in uterine biology, 21 day old OVX rats were treated with a 20 mg/1kg dose of tamoxifen and tissues were harvested for seven time points (0, 4, 12, 24, 48, 72, 96 hrs) before RNA extractions. Change in mRNA expression for the MMPs and TNF-α and MCP-1 were assessed with Real Time Quantitative Polymerase Chain Reaction using 18s rRNA as a comparative control gene. Second, MMP and inflammation marker protein levels were assessed by performing protein extraction, followed by Western blots and immunoblotting.

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The effects of sea-level rise and species The dynamics of cell proliferation and death in the composition on productivity and decomposition in a chick embryo neuroepithelium brackish marsh UG Courtney Shipman and Mary Desmond Katherine A. ShepardUG and J. Adam Langely Department of Biology, Villanova University Department of Biology, Villanova University Smithsonian Environmental Research Center The processes of mitosis (cell division) and apoptosis (programmed cell death), allow a tissue to establish and maintain a functional Vertical accretion of organic matter has historically been able to number of cells. Little is known about the dynamics of these maintain elevation relative to sea-level in many marshes, but as sea- processes in the neuroepithelium (brain tissue) of the chick embryo as level rise (SLR) accelerates to the highest rates in the last 5000 years, it approaches the point of hatching. The purpose of this project is to ocean inundation threatens to overtake these critical ecosystems. determine the growth of the neuroepithelium in the late stage chick embryo as it is becoming fully differentiated by establishing the However, the community shifts induced by elevated atmospheric CO2 number of mitotic cells and apoptotic cells. It is hypothesized that the (favoring C plant productivity) and increased N availability (favoring 3 number of mitotic cells will remain relatively low, while the number of C4 plant productivity) may alter plant productivity and soil organic apoptotic cells may increase, resulting in an overall plateau in cell matter decomposition, the primary determinants of elevation change number. Results of this experiment will establish normal rates of brain in peat-forming marshes. To determine these effects of SLR and growth in late stages of the chick embryo, and can be applied in the community shifts, I established a marsh organ in a brackish marsh. future to study normal and abnormal brain tissue development of Above-ground and below-ground productivity decreased with rising vertebrates. sea-level, although the decline was stronger in the C4 grass Spartina patens than the C3 sedge Schoenoplectus americanus. Spartina fine roots were reduced under SLR, while Schoenoplectus decreased coarse root production. Decomposition rate, measured by direct mass loss and soil redox potential, decreased as sea-level rose in soils with both species. This data suggests that plant productivity will be reduced with SLR, decreasing vertical accretion, with a pronounced effect under high N conditions. However, organic matter decomposition rates will also decrease, potentially counteracting the loss of organic matter inputs to maintain vertical accretion rates.

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Eutrophication Alters Mangrove-Salt Marsh Analysis of the role of inflammatory pathways on Community Competition estrogen-induced uterine tissue remodeling in the UG ovariectomized immature rat Lorae' T Simpson and Samantha Chapman Department of Biology, Villanova University Shreya TrivediUG, Alec VishnevskyUG and Louise Russo Department of Biology, Villanova University The salt marsh-mangrove ecotone occurs in many geographic locations and consequently represents an important transitional plant The administration of a single physiological dose of 17β-estradiol community where the effects of global change may be first evident. (E2:40μg/kg) to an ovariectomized female rat causes a dramatic Vegetation response to global change is predicted to be most rapid at dissembling of the dense collagen matrix in the endometrial stromal transitional boundaries because species are at their physiological architecture of the rat uterus. Previous data indicates that proteolytic limits and are most sensitive to environmental change. We examined enzymes, matrix-metalloproteinases (MMPs), are critical for estrogen- the population dynamics and growth of Avicennia germinans, the induced matrix remodeling during tissue growth. However, how black mangrove, which reaches its northern limit in Florida's salt estrogen binding to its receptor causes MMP activation is unclear. marsh mangrove ecotone. At its northern extent, A. germinans Because there is an inflammatory-like response within four hours after competes with salt marsh vegetation for limiting resources such as estrogen administration, analyzing if inflammation is important for nitrogen. We performed a field experiment examining the interaction MMP expression is of a particular interest. Indomethacin is an inhibitor of nitrogen enrichment and interspecies competition on A. germinans of the COX enzyme pathway that is key in prostaglandin production productivity. Plots containing an A. germinans seedling surrounded and inflammation. Pretreatment with indomethacin in conjunction with by temperate salt marsh species were subjected to competition estrogen to the ovariectomized immature female rat will help reduction by root trenching or above ground clearing and fertilized demonstrate the importance of estrogen-induced inflammation for the with urea. A. germinans biomass increased (35%) when trees were activation of MMPs that ultimately alter the endometrial matrix. The subjected to increased N in the above ground competition reduction. data shows that inhibiting the COX pathway with Indomethacin Conversely, trenching had a negative effect on mangrove productivity partially blocked matrix turnover in the estrogen-induced rat uterus and N could not reverse this suppression. The results of this and suggests that hormone-induced inflammation is important in experiment will be useful in teasing apart the importance of matrix degradation. In addition, indomethacin does not change gene competition and N enrichment on the maintenance of transitional expression of MMPs and other inflammatory mediators, but does have communities. an effect at the protein level for MMP-2, MMP-9, Tnf-alpha, mast cell tyrptase and neutrophil elastase, indicating a post-transcriptional regulation.

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Hybrid chickadees show higher survival than Black- How does N Pollution Affect the Decomposition in a capped and Carolina chickadees in southeastern Brackish Marsh? Pennsylvania Le WangG and Adam Langley Stephanie G. WrightG and Robert L. Curry Department of Biology, Villanova University Department of Biology, Villanova University

Marshes accumulate mineral and organic matter to maintain a The Black-capped and Carolina chickadee hybrid zone is a rare constant soil elevation relative to sea level. Recently, accelerating moving hybrid zone: it is shifting northward, but the causes for this sea-level rise resulting from global warming has contributed to vast movement are unknown. Our goal was to use AICC to investigate the losses of marsh area. An ongoing field experiment has shown that influence of site, sex, and year on the survival and recapture rates of increased nitrogen (N) pollution may enhance plant productivity, which Black-caped, Carolina, and hybrid chickadees over approximately ten should help marshes accumulate soil. However, it remains unknown years at three sites, a Carolina Chickadee-only site, a hybrid-only site, how N pollution affects marsh decomposition that could partially and a site that consists of predominantly Black-capped Chickadees negate peat accumulation. We conducted a field manipulation in a with a few hybrids. Sex and site were the most important factors brackish marsh to determine the N effects on peat decomposition. We influencing survival and recapture rate in all populations. Hybrid found that N pollution tends to reduce the decomposition rate of peat chickadees showed higher average survival rates than both parental and inhibits the enzyme activity of polyphenol oxidase. In contrast, species. Recapture rate differed among sites, but only among sexes elevated CO2, which reduces soil N availability, tends to stimulate at the Carolina-only site. These data indicate that hybrid chickadees decomposition. We also conducted a companion laboratory may have survival advantages over their parental species despite incubation to isolate the direct effects of N on decomposition and to evidence that they may be reproductively less successful. The explore how N may interact with O2 availability. N addition reduced evolutionary divergence between the Carolina Chickadee and Black- peat respiration rates, suppressed production of dissolved organic capped Chickadee clades is at least 2.5 million years, a number in carbon and organic nitrogen at low O2 concentrations, and agreement with estimates for the minimum divergence required for the constrained the accumulation of inorganic carbon in the porewater. hybrids of two avian species to show hybrid vigor. These results Because of the ecosystem services provided by marshes, it is critical indicate the potential for some hybrid vigor, a trend not yet noted in to understand the impact of N pollution on the processes that sustain the chickadee literature. marshes.

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CPATH: Distributed Expertise - Collaborating with ENSEMBLE: Enriching Communities and Collections other Disciplines to Support Education in Computing Lillian Cassel1, Thomas Way1, Kim Pearson2, Deborah Lillian Cassel1, Ed Fox2, Weiguo Fax2, Richard Furuta3, Tatar3, Steve Harrison3 and Sridhara PotluriG Frank Shipman3, Dan Garcia4, Lois Delcambre5, Peter 1 6 7 G Department of Computing Sciences, Villanova University Brusilovsky , Greg Hislop and Sridhara Potluri 2 3 1 TCNJ, Virginia Tech Department of Computing Sciences, Villanova University 2 3 Virginia Tech, TAMU, 4University of California Berkeley, 5 6 Distributed Expertise is collaborating with another discipline or in the Portland State University, University of Pittsburg, 7Drexel University same discipline. The collaboration may involve complementary topics or one topic explored from multiple perspectives. It emphasizes the Ensemble is the computing pathway project in the NSF National exploration of the challenges and potential of collaboration across STEM Digital Library. Ensemble is building a distributed portal department and university boundaries. The goals of the project are to providing access to a broad range of educational resources for develop resources that support creative explorations of the entirety of computing while preserving the collections and their associated the computing and information subject and to develop inter and multi- curation processes. CITIDEL and CSTA are two of the major disciplinary partnerships among computing and non-computing educational resources that are part of this expanding collection. We programs for the benefit of all. want to encourage contribution, use, reuse, review and evaluation of

educational materials at multiple levels of granularity and we seek to One initial experience involved a game development course taught support the full range of computing education communities including simultaneously at Villanova University and The College of New Jersey computer science, computer engineering, software engineering, (TCNJ). This involved experience in faculty collaboration, student information science, information systems and information technology collaboration and cross-institutional schedule coordination. Another as well as other areas often called “computing + X” or “X informatics”. project combined faculty at Virginia Tech with a colleague at the

University of Limerick, Ireland. A current project explores complex Ensemble provides content, communities, and tools for computing interactions among two courses at the TCNJ and two at Villanova. educators and students. The content consists of freely available The courses cover Games Programming, Interactive Story Telling, computing education resources stored within Ensemble or at other Software Engineering, and Computing with Images. This project tries locations. Ensemble provides federated search, indexing, to demonstrate how four courses, each with its own learning annotation, reviews, and other services to make these resources outcomes, can be coordinated to enhance learning and support accessible, visible, and more useful to the community. Ensemble faculty expertise in a multidisciplinary manner through the also provides other sources of information of interest to computing development of three deliverables: an iPhone game, a Sprite editor, educators. This content includes information streams such as news, and a Storytelling Engine. The project website is setup with Drupal (a event notices, and blogs. This project is funded by the National Content Management System) to provide information and to support Science Foundation via the NSDL Pathways program. different communities and people of similar interests. This project is funded by NSF.

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CSTA Source: A Web Repository of K-12 Computer The Computing Ontology and its Implications in Science Teaching and Learning Materials Computing Education Bala Krishna ChitneniG and Lillian N Cassel Siva Kumar InguvaG, Lillian N Cassel and Sandeep N Department of Computing Sciences, Villanova University SreerambhatlaG Department of Computing Sciences, Villanova University

The Computer Science Teachers Association is a membership organization that supports and promotes the teaching of computer An ontology of all of the computing disciplines is available for use in a science and other computing disciplines. The project is about number of applications. It describes various disciplines, topics, designing and maintaining CSTA portal which is a web repository of subtopics that belong to the domain of computing. The computing K-12 Computer Science Teaching and Learning Materials. It is a ontology is a comprehensive collection of topics, put in order by collection of materials developed specifically for computer science experts in the various subfields. All the fields and subfields are and information technology education. The repository content is organized as classes and objects in a hierarchical conceptual organized as Communities and sub communities. Within each structure with parent, child or sibling relationships among them. Apart community are a number sub communities and collections. Each from these relations the fields/classes also have the properties Isa, collection has a number of items relating to the collection, which can Uses, Used By, Equals, Is Part of, Has Part etc. Protégé, an open be in any format. The repository provides the flexibility to source ontology editor is used to build, organize and maintain these accommodate differing needs of communities by allowing them to properties; inter-dependencies between these properties are decide on policies such as: who contributes content, whether there maintained by symmetric, inverse and transitive relationships within will be a review process, who will have access, workflow - reviewing, the properties eg. Uses -> Used By are inverse to each other. Protégé editing, metadata, management of collections. The CSTA web generates a special type of XML file called OWL (Web Ontology repository is customized to include new features to address the needs Language). OWL is an ontology modeling language having a XML of K-12 teachers and students. Some of the recent enhancements surface syntax. include the ability of users to comment and give ratings to the resources in the repository, adding a counter which counts the An important task of the current work is to provide a usable, visible number of visits to the K-12 repository, adding a counter which counts interface to the Ontology. This visualization provides a graphical the number of downloads of individual resources in the repository, representation of the ontology that is essential for effective dividing users into groups and providing different access privileges to understanding of bridges between domains. The Computing Ontology people in the different groups. The various aspects of our project also provides a controlled vocabulary to be used as an indexing tool include: (1) making various enhancements to the web repository by in collections of resources for computing education. Examples in the adding new features, (2) defining appropriate metadata and methods CITIDEL project, implemented in DSpace, and the Ensemble project, for indexing computing resources - including using an ontology to built with Drupal, will be illustrated on the poster. describe computing topics, (3) instrumenting the portal so that we can track use and reuse of resources (so that faculty can easily get metrics analogous to citation counts for the educational resources that they create), (4) integrating social software into the portal, (5) providing access to resources at multiple levels of granularity.

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An Efficient Routing Topology for Wireless Networks Colored Petri Nets Based Models of Economic with Directional Antennas Systems and Integration into an Asset Planning Tool UG UG Kristin Raudonis and Mirela Damian Carmen Nigro , Vijay Gehlot and Thomas Way Department of Computing Sciences, Villanova University Department of Computing Sciences, Villanova University

Recent years have seen significant advances in directional antenna Asset planning tool is a system architecture that incorporates technologies, and the beginnings of deployment of directional ‐ participatory and asset based community development antennas into wireless networks. A directional antenna is capable of methodologies. For defense applications, such tools can give concentrating its transmission energy within a narrow angle, aimed in commanders, field personnel, U.S. civilians, citizens, NGOs, etc. an intended direction. Our research is centered around the following (stakeholders) strategic and operational understanding of friendly and question: Can we provide each node with multiple directional neutral populations with the end goal of influencing positive change antennas, and configure these antennas appropriately to form efficient through maximization of assets and resources. The Computing communication graphs? Towards resolving this question, we analyze Sciences department at Villanova is engaged in a research and the suitability of nearest-neighbor graphs as communication graphs development effort to create an asset planning tool for the US Army. for networks with directional antennas. One could divide the plane One component of this toolset is a module for modeling and analyzing around each wireless device into a small number of cone-shaped economies of different scales. This work focused on identifying the regions, and orient antennas to laser-point to a nearest-neighbor in computational approach to modeling economic systems, creation of each region. We establish theoretically that the nearest-neighbor such a system and integrating it into a Content Management System graph with four quadrants per node has very nice properties: it is (CMS) that forms the basis of the proposed asset planning toolset. planar, meaning that no two edges cross each other, and each of its We followed the agent‐based approach to computational economics planar faces is either a triangle or a quadrilateral. Furthermore, this and used Colored Petri Nets (CPNs), a formal graphical modeling graph is a spanner, meaning that it contains short paths between language, to create executable models. The agent‐based approach each pair of nodes. These properties are essential to efficient end-to- is the computational study of economic processes modeled as end communication, low power consumption and reduced signal dynamic systems of interacting agents. Since the modeling toolset is interference. Another significant advantage is that the nearest- decoupled from the content management system, we used a neighbor graph can be constructed and maintained in a local manner, distributed processing approach to integrate the two systems. based on the information at each node obtained from a small neighborhood. These characteristics make the nearest-neighbor graph a highly efficient routing topology for mobile wireless networks with directional antennas.

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Blast Shield Protection G G Comparison of Silicon Nitride Nanowires synthesized Ledjan Qato , Devin Pellicone , Gerard Jones, Sridhar by silica nanopowders and silica gel Santhanam and Ed Dougherty G Department of Mechanical Engineering, Villanova University Sanket Deshmukh , Kei-Peng Jen and Sridhar Santhanam Department of Mechanical Engineering, Villanova University Enhanced energy dissipation in blast protection systems is considered in this work. Our approach is to consider materials and structures historically used in lightweight blast-protection systems, such as in Sillicon nitride nanowires were synthesized by heating mixtures of armored vehicles, and improve the energy dissipation ability. The silica nanopowders (5-15nm) and/or silica gel (~300 mesh size) with geometry of the structure chosen for study is a parallel array of thin- activated charcoal at 1450°C for 6hrs in the presence of constant flow walled steel tubes joined side-by-side. This array of tubes is of high purity nitrogen without metal catalysts. The powder mixtures sandwiched between two thin steel plates. The tubes are welded to were molded to form cylindrical pellets that were interlaced with the steel plates on both sides. This geometry is modeled both with graphite wafers and placed inside a cylindrical graphite crucible. The and without liquid filling. Without liquid filling, the sandwich plate cylindrical crucible was then placed either horizontally or vertically in absorbs the energy of a blast primarily by plastic deformation in the horizontal alumina tube furnace with a nitrogen inlet. The bending and crushing of the structure. In the case where the array of thickness of the nanowire layer that grew on the graphite wafer was steel tubes is liquid-filled, a number of capillary tubes of 3-mm 75-150µm. By using the SEM and TEM, the width and thickness of diameter or smaller and variable lengths are connected to the liquid- nanowires was determined and ranged from 1.5-1.8µm and 300- filled cavities. When the geometry is compressed upon exposure to a 450nm, respectively. X-ray Diffraction (XRD) and ATF-FTIR high-pressure blast wave, the liquid is forced through the capillaries at Spectroscopy confirmed the presence of α-Si3N4, growing along high speeds, increasing energy dissipation through viscous [001] direction. The vapor-solid mechanism was established to mechanisms thereby reducing the negative effects on personnel, interpret the growth of the nanowires. Based on the experimental equipment, and structures. Analytical and numerical models are used results, the theory of “nitrogen trapping cloud” was proposed and to estimate the energy dissipated by the verified to explain the favorable formation of silicon nitride nanowires. sandwich plates. This paper also summarizes the pattern of growth, quantity and quality of silicon nitride nanowires using silica nanopowders and silica gel as base materials.

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Mechanical Characterization of the Cement Line in Multi-Species Femur Bone through Nanoindentation Timothy MontalbanoG and Gang Feng Department of Mechanical Engineering, Villanova University

The secondary osteon of adult cortical bone has been well characterized by nanoindentation in several species. The border of the osteon --the cement line --is less often studied because of its <5µm radius. This interface is nevertheless important due to its ability to arrest or deflect cracks of certain lengths. In this study, nanoindentation was used to characterize the mechanical properties of the cement line to better understand the role of these properties in crack arrestment. Two distinct osteons from the femur of a lamb and two from that of a steer were indented around the cement line region. In the femur of both species indented, the average modulus and hardness of the cement line were found to be less than the surrounding osteon and interstitial bone. Also, the nanoindenter tip was used to raster scan the topography of the cement line region. The cement line was shown to lie in a local valley relative to its neighboring bone. In addition to better understanding the cement line as a barrier to crack propagation, this research may have some bio- mimetic applications, considering the small, relative size of the cement line to the larger, encapsulated structure of the osteon.

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