DOCSLIB.ORG

Information to Users

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Information to Users INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adverselyaffect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning ,H the upper left-hand corner and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. University Microfilms International A Beil & Howell Information Company 300 North Zeeb Road. Ann Arbor. M148106-1346 USA 313, 761-4700 800.521-0600 ~_..,------ Order Number 9215041 Stability in closed ecological systems: An examination of material and energetic parameters Shaffer, Jonathon Andrew, Ph.D. University of Hawaii, 1991 Copyright @1991 by Shaffer, Jonathon Andrew. All rights reserved. V-M-I 300N. ZeebRd. Ann Arbor, MI48106 STABILITY IN CLOSED ECOLOGICAL SYSTEMS: AN EXAMINATION OF MATERIAL AND ENERGETIC PARAMETERS A DISSERTATION SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAII IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN MICROBIOLOGY DECEMBER 1991 BY Jonathon Shaffer Dissertation Committee: Francoise Robert, Chairwoman Agnes Fok Roger Fujioka David Karl Bruce McConnell © copyright 1991 by Jonathon A. Shaffer iii ACKNOWLEDGMENT "All men must escape at times from the deadly rhythm of their private thoughts. It is part of the process of life among thinking beings." - R. Chandler. This dissertation is dedicated to the memory of Clair Edwin Folsome - the father of closed system ecology and my mentor. When searching a book on baby names, Ivone noticed that the name Clair Edwin translates as an "illuminating friend" - he was that exactly. Clair showed by example that science was not a burden but a privilege, an enjoyment and an exercise of spirit. His offering ~o the world of "little planets in bottles" was part paradigm and part whimsy. I hope in my dissertation the element of wonder didn't get too lost in numbers. I thank my colleague Andrew Brittain for being incorruptible, and for the intelligence to make this research exciting. It would otherwise have been a very dark laboratory after Clair's death. I also thank Don Obenhuber for getting me interested in CES in the first place. I thank Susanna Murata and Charles Buck for their decency as scientists and human beings and simply for their friendship. I thank Edward Siwak for his wise insights into iv the human condition and for a million laughs. I thank Ron Kennedy and John Spencer for showing me the ropes. And I thank Debra Brittain, Cindy Fukunaga, Ira Fujisaki, and Bettye Shines for being with me. You all mean a lot. I thank my dissertation committee for a job well done. I especially thank my chairwoman Francoise Robert for unselfishly rising to the occasion after Clair's death. This dissertation owes much to her. My mother, father, brother, sister, wife and children I wouldn't know where to begin - perhaps there is something in this work that Louie, AUdrey and Jondi-Dondi can use some day to make the big CES a better place to live. v ABSTRACT Closed ecological systems (CES) are gas-sealed microcosms. One-liter CES have been shown to maintain life in a consistent manner for over 25 years (Folsome and Hanson, 1986). Operationally: stability was defined as a constant total biomass (live plus dead organic material) for a period exceeding one turnover of all carbon pools. CES differing solely in total concentrations of carbon (30-150 roM), nitrogen (4-13 roM) and phosphorus (0.3-0.9 roM), or in a fundamental aspect of configuration (i.e., gas-open versus true materially-closed microcosms), were compared to determine: 1) which systems attain a stable state; 2) how biomass levels varied relative to material composition; and 3) whether a given stable biomass concentration was related to some unique set drawn from other parameter-defined relations. Twenty-seven of a total of 28 CES prototypes achieved stability in about 60 days. Stable biomass-C levels (typically 10-40 roM) could be described solely as a linear function of the total C concentration. Limiting N concentrations depressed expected biomass levels, whereas limiting P conditions caused an increase in biomass. vi Limitations in Nand P coincided to those predicted by the Redfield biomass C:N:P ratios (106:16:1). Various parameters measured in stable CES, such as detrital-C, live-C, carbon production, respiration, chlorophyll-a concentration, viable counts, and heterotrophic substrate range, were differentially affected by total C, N, and/or P concentrations. Furthermore, for a given radiant energy flux and comparative physical conditions, data showed no unique level of stable biomass, nor was a given biomass level indicative of some unique parameter-defined system configuration. Gas-open systems were similar in most attributes to closed systems except for about a 2- to 6-fold relative increase in detritus, fluctuating biomass levels, and longer time periods necessary for stabilization. These data suggest that laboratory-scale material closure may facilitate ecosystem stability. Overall, results suggest that CES prioritize the establishment of some characteristic bioelemental pool structure over that of energy flux or efficiency of energy utilization. Results also indicate that it should be possible to predictably scale-·up small CES as regards technological applications. vii TABLE OF CONTENTS ACKNOWLEDGMENT.. ..•• . .iv ABSTRACT .•.. .••• .. vi LIST OF TABLES.. •.•• .. xi LIST OF FIGURES •....•.••.•....•••.•. xaa a LIST OF ABBREVIATIONS. • • ••••....•. xiv KEY TO CARBON-NORMALIZED POOLS AND TURNOVERS .•..•. .xv CHAPTER I. BACKGROUND 1.1 Summary of Closed Ecological System Research .1 1.2 Scope of this Dissertation ••....•.•. .4 CHAPTER II. INTRODUCTION 2.1 In Vitro Microecosystems. ....••....5 2.2 Gas-open Microcosms in Ecologic Research •••••.•6 2.3 Closed System Biology .•...•..•.... .10 2.4 Terminology .•...••..•...••••• •. .12 CHAPTER III. LITERATURE ~EVIEW 1: CLOSURE AS A UNIQUE RESEARCH TOOL 3.1 Biology and Nonequilibrium Thermodynamic (NET) Theory ..••.•......•14 3.1.1 Problems in Applying NET Theory to Biology. ••.....•.•• 15 3.2 Bioregenerative Space Life Support •.•••••. 18 3.2.1 The Engineering Approach to Life Support . 20 3.2.2 The Holistic Approach to Life-Support ....23 CHAPTER IV. LITERATURE REVIEW 2: ECOLOGICAL CONCEPTS IMPORTANT TO CLOSED AND OPEN MICROCOSMS 4.1 Per~istence and Stability....•..•..•.•• 30 4.2 Persistence in sediment~Type Microecosystems... 31 4.2.1 Persistence in Nutrient-Amended Microecosystems.•..•.......•.. 31 4.2.2 Persis'tence in Nutrient-Poor Open Microcosms. •..••.. .33 4.2.3 Factors Influencing Persistence in Microecosystems. ...•..... .37 viii 4.3 The Concept of stability in Ecology. 38 4.3.1 stability in Microecosystems . .. 43 4.3.2 stability as Balanced Growth in (Open) Microcosms ...... .• .. 46 4.3.3 stability as Balanced Growth in CES: Importance of Closure ...........•50 4.4 Total Biomass Concentration as the Indicator of Microecosystem stability. ..•..... .... 52 CHAPTER V. DISSERTATION GOALS AND OBJECTIVES 5.1 Introduction.•....•.........•.... 54 5.2 Open Versus Closed Microecosystems 54 5.3 Stability and Material Potential in CES..•....•55 CHAPTER VI. MATERIALS AND METHODS 6.1 Closed System Media. .. 57 6.2 Total Biomass Carbon. .. •. ..... .. 60 6.3 Respiration. ••••. .. •.... 62 6.4 Live Biomass Carbon .... 65 6.5 Carbon-Specific DNA Synthesis Rate. .. •. .66 6.6 Chlorophyll-a. ..•....•....... •. .69 6.7 Heterotrophic Viable Counts and CFU Morphotypes ..•70 6.8 Metabolic Processes. .•.•...• .•. .71 6.9 Epifluorescence Acridine Orange Microscopy ••.•. 76 6.10 Heterotrophic Substrate Range•...•....... 78 6.11 Parameter Relations. ..•...... •. .. 78 CHAPTER VII. EFFECTS OF BIOLOGICAL DIVERSITY ON STABILITY IN CES 7.1 Preliminary Gnotobiotic Experiments... 0 ••••• 81 7.2 Effects of Inoculum Concentration .. •... 84 7.3 Experimental Design. ..•.. .. • ....•..•87 7.4 Results ................... G ••• 88 7.5 Discussion. .... 108 7.6 Conclusion. ................... 110 CHAPTER VIII. ASPECTS OF STABILITY AND MATERIAL BUDGETS IN OPEN VERSUS CLOSED MICROCOSMS 8.1 Introcluction. ..... .. ........•... .111 8.2 Experimental Design. .. 113 8.3 Results. .•.... .. •........... 114 8.4 Discussion. .... .. 127 8.5 Conclusion...................•..137 ix CHAPTER IX. RESPONSE OF STABLE CLOSED SYSTEMS TO OPENING 9.1 Introduction. • • ••••••••••••••139 9.2 Experimental Design •••••••••••••••• 139 9.3 Results. , Cl ••••••••••••••••••••141 9.4 Discussion. ••••••••••• • .148 9.5 Discussion Open
Load more

Recommended publications
  • The Search for Extraterrestrial Intelligence
    THE SEARCH FOR EXTRATERRESTRIAL INTELLIGENCE Are we alone in the universe? Is the search for extraterrestrial intelligence a waste of resources or a genuine contribution to scientific research? And how should we communicate with other life-forms if we make contact? The search for extraterrestrial intelligence (SETI) has been given fresh impetus in recent years following developments in space science which go beyond speculation. The evidence that many stars are accompanied by planets; the detection of organic material in the circumstellar disks of which planets are created; and claims regarding microfossils on Martian meteorites have all led to many new empirical searches. Against the background of these dramatic new developments in science, The Search for Extraterrestrial Intelligence: a philosophical inquiry critically evaluates claims concerning the status of SETI as a genuine scientific research programme and examines the attempts to establish contact with other intelligent life-forms of the past thirty years. David Lamb also assesses competing theories on the origin of life on Earth, discoveries of ex-solar planets and proposals for space colonies as well as the technical and ethical issues bound up with them. Most importantly, he considers the benefits and drawbacks of communication with new life-forms: how we should communicate and whether we could. The Search for Extraterrestrial Intelligence is an important contribution to a field which until now has not been critically examined by philosophers. David Lamb argues that current searches should continue and that space exploration and SETI are essential aspects of the transformative nature of science. David Lamb is honorary Reader in Philosophy and Bioethics at the University of Birmingham.
    [Show full text]
  • Nicholas Georgescu-Roegen Whose Contribution Was Directed Toward the Integration of Economic Theory with the Principles of Thermo- Dynamics
    The Complex History of Sustainability An index of Trends, Authors, Projects and Fiction Amir Djalali with Piet Vollaard Made for Volume magazine as a follow-up of issue 18, After Zero. See the timeline here: archis.org/history-of-sustainability Made with LATEX Contents Introduction 7 Bibliography on the history of sustainability 9 I Projects 11 II Trends 25 III Fiction 39 IV People, Events and Organizations 57 3 4 Table of Contents Introduction Speaking about the environment today apparently means speaking about Sustainability. Theoretically, no one can take a stand against Sustain- ability because there is no definition of it. Neither is there a history of Sustainability. The S-word seems to point to a universal idea, valid any- where, at any time. Although the notion of Sustainability appeared for the first time in Germany in the 18th century (as Nachhaltigkeit), in fact Sustainability (and the creative oxymoron ’Sustainable Development’) isa young con- cept. Developed in the early seventies, it was formalized and officially adopted by the international community in 1987 in the UN report ’Our Common Future’. Looking back, we see that Western society has always been obsessed by its relationship with the environment, with what is meant to be outside ourselves, or, as some call it, nature. Many ideas preceded the notion of Sustainability and even today there are various trends and original ideas following old ideological traditions. Some of these directly oppose Sustainability. This timeline is a subjective attempt to historically map the different ideas around the relationship between humans and their environment. 5 6 Introduction Some earlier attempts to put the notion of sustainability in a historical perspective Ulrich Grober, Deep roots.
    [Show full text]
  • When Corridors Work: Insights from a Microecosystem
    ecological modelling 202 (2007) 441–453 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/ecolmodel When corridors work: Insights from a microecosystem Martin Hoyle ∗ School of Biology, University of Nottingham, Nottingham NG7 2RD, UK article info abstract Article history: Evidence for a beneficial effect of corridors on species richness and abundance in habitat Received 14 February 2006 patches is mixed. Even in a single microecosystem of microarthropods living in moss patches Received in revised form connected by a moss corridor, experiments have had different results (positive and neutral). 2 November 2006 This paper attempts to provide an explanatory framework for understanding these results. I Accepted 7 November 2006 developed a stochastic individual-based model of the moss—microarthropod microecosys- Published on line 12 December 2006 tem. Some of the movement parameter values were estimated from two manipulation experiments. Assuming mortality independent of the season, and assuming the corridors Keywords: merely increase migration rates between patches, only a very weak beneficial effect of corri- Conservation dors was possible in simulations. Incorporating a seasonal pattern to mortality caused some Habitat fragmentation simulated populations to die out, which were then occasionally rescued by migrants from Individual-based model the adjacent patch. Corridors were slightly beneficial if there was little or no immigration Metapopulation from the surrounding matrix. In contrast, corridors were very beneficial in simulations that Microarthropod incorporated lower emigration to the matrix when a corridor was present, even for moder- ate levels of immigration from the matrix. Thus corridors may reduce the chance of species extinction in patches even when the lifespan of the individuals is long relative to the time- scale in question.
    [Show full text]
  • Flourishing and Discordance: on Two Modes of Human Science Engagement with Synthetic Biology
    Flourishing and Discordance: On Two Modes of Human Science Engagement with Synthetic Biology by Anthony Stavrianakis A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Anthropology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Paul Rabinow, Chair Professor Xin Liu Professor Charis Thompson Fall 2012 Abstract Flourishing and Discordance: On Two Modes of Human Science Engagement with Synthetic Biology by Anthony Stavrianakis Doctor of Philosophy in Anthropology University of California, Berkeley Professor Paul Rabinow, Chair This dissertation takes up the theme of collaboration between the human sciences and natural sciences and asks how technical, veridictional and ethical vectors in such co-labor can be inquired into today. I specify the problem of collaboration, between forms of knowledge, as a contemporary one. This contemporary problem links the recent past of the institutional relations between the human and natural sciences to a present experience of anthropological engagement with a novel field of bioengineering practice, called synthetic biology. I compare two modes of engagement, in which I participated during 2006–2011. One project, called Human Practices, based within the Synthetic Biology Engineering Research Center (SynBERC), instantiated an anthropological mode of inquiry, explicitly oriented to naming ethical problems for collaboration. This project, conducted in collaboration with Paul Rabinow and Gaymon Bennett, took as a challenge the invention of an appropriate practice to indeterminate ethical problems. Flourishing, a translation of the ancient Greek term eudaemonia, was a central term in orienting the Human Practices project. This term was used to posit ethical questions outside of the instrumental rationality of the sciences, and on which the Human Practices project would seek to work.
    [Show full text]
  • Closed Ecological Systems, Space Life Support and Biospherics
    11 Closed Ecological Systems, Space Life Support and Biospherics Mark Nelson, Nickolay S. Pechurkin, John P. Allen, Lydia A Somova, and Josef I. Gitelson CONTENTS INTRODUCTION TERMINOLOGY OF CLOSED ECOLOGICAL SYSTEMS:FROM LABORATORY ECOSPHERES TO MANMADE BIOSPHERES DIFFERENT TYPES OF CLOSED ECOLOGICAL SYSTEMS CONCLUSION REFERENCES Abstract This chapter explores the development of a new type of scientific tool – man- made closed ecological systems. These systems have had a number of applications within the past 50 years. They are unique tools for investigating fundamental processes and interactions of ecosystems. They also hold the potentiality for creating life support systems for space exploration and habitation outside of Earth’s biosphere. Finally, they are an experimental method of working with small “biospheric systems” to gain insight into the functioning of Earth’s biosphere. The chapter reviews the terminology of the field, the history and current work on closed ecological systems, bioregenerative space life support and biospherics in Japan, Europe, Russia, and the United States where they have been most developed. These projects include the Bios experiments in Russia, the Closed Ecological Experiment Facility in Japan, the Biosphere 2 project in Arizona, the MELiSSA program of the European Space Agency as well as fundamental work in the field by NASA and other space agencies. The challenges of achieving full closure, and of recycling air and water and producing high- production crops for such systems are discussed, with examples of different approaches being used to solve these problems. The implications for creating sustainable technologies for our Earth’s environment are also illustrated. Key Words Life support r biospherics r bioregenerative r food r air r water recycling r microcosm rclosed ecological systems rBios rNASA rCEEF rBiosphere 2 rBIO-Plex.
    [Show full text]
  • A Keystone Predator Controls Bacterial Diversity in the Pitcher-Plant (Sarracenia Purpurea) Microecosystem
    Environmental Microbiology (2008) 10(9), 2257–2266 doi:10.1111/j.1462-2920.2008.01648.x A keystone predator controls bacterial diversity in the pitcher-plant (Sarracenia purpurea) microecosystem Celeste N. Peterson,1,2* Stephanie Day,3,4† Introduction Benjamin E. Wolfe,1 Aaron M. Ellison,4 Bacterial assemblages may be structured by many Roberto Kolter2 and Anne Pringle1 forces at both local and regional scales. They are inte- 1Department of Organismic and Evolutionary Biology, grated into complex food webs and their composition, in Harvard University, Cambridge, MA 02138, USA. terms of species diversity and cell abundance, may be 2Department of Microbiology and Molecular Genetics, controlled by a combination of ‘top-down’ factors, such Harvard Medical School, Boston, MA 02115, USA. as grazing by predators, and ‘bottom-up’ factors, such 3Department of Biology, Howard University, Washington, as nutrient availability or other environmental param- DC 20059, USA. eters (Moran and Scheidler, 2002). Simple and well- 4Harvard Forest, Harvard University, Petersham, characterized natural model ecosystems can be used to MA 01366, USA. determine how each of these forces function and inter- act with each other at different scales. However, there is Summary a dearth of such systems available for field studies. That makes the model ecosystem of the carnivorous pitcher- The community of organisms inhabiting the water- plant Sarracenia purpurea (Sarraceniaceae) particularly filled leaves of the carnivorous pitcher-plant Sarrace- valuable. nia purpurea includes arthropods, protozoa and The food web that forms in the water-filled leaves of bacteria, and serves as a model system for studies of S. purpurea (Sarraceniaceae) has been used as a model food web dynamics.
    [Show full text]
  • Lessons Learned from Biosphere 2 and Laboratory Biosphere Closed Systems Experiments for the Mars on Earth® Project
    Biological Sciences in Space, Vol.19 No.4 (2005): 250-260 © 2005 Jpn. Soc. Biol. Sci. Space Lessons Learned from Biosphere 2 and Laboratory Biosphere Closed Systems Experiments for the Mars On Earth® Project Abigail Alling1, Mark Van Thillo1, William Dempster2, Mark Nelson3, Sally Silverstone1, John Allen2 1Biosphere Foundation, P.O. Box 201 Pacific Palisades, CA 90272 USA 2Biospheric Design (a division of Global Ecotechnics) 1 Bluebird Court, Santa Fe, NM 87508 USA 3Institute of Ecotechnics, 24 Old Gloucester St., London WC1 U.K. Abstract Mars On Earth® (MOE) is a demonstration/research project that will develop systems for maintaining 4 people in a sustainable (bioregenerative) life support system on Mars. The overall design will address not only the functional requirements for maintaining long term human habitation in a sustainable artificial environment, but the aesthetic need for beauty and nutritional/psychological importance of a diversity of foods which has been noticeably lacking in most space settlement designs. Key features selected for the Mars On Earth® life support system build on the experience of operating Biosphere 2 as a closed ecological system facility from 1991-1994, its smaller 400 cubic meter test module and Laboratory Biosphere, a cylindrical steel chamber with horizontal axis 3.68 meters long and 3.65 meters in diameter. Future Mars On Earth® agriculture/atmospheric research will include: determining optimal light levels for growth of a variety of crops, energy trade-offs for agriculture (e.g. light intensity vs. required area), optimal design of soil-based agriculture/horticulture systems, strategies for safe re-use of human waste products, and maintaining atmospheric balance between people, plants and soils.
    [Show full text]
  • Author's Instructions For
    Feasibility Analysis for a Manned Mars Free-Return Mission in 2018 Dennis A. Tito Grant Anderson John P. Carrico, Jr. Wilshire Associates Incorporated Paragon Space Development Applied Defense Solutions, Inc. 1800 Alta Mura Road Corporation 10440 Little Patuxent Pkwy Pacific Palisades, CA 90272 3481 East Michigan Street Ste 600 310-260-6600 Tucson, AZ 85714 Columbia, MD 21044 [email protected] 520-382-4812 410-715-0005 [email protected] [email protected] Jonathan Clark, MD Barry Finger Gary A Lantz Center for Space Medicine Paragon Space Development Paragon Space Development Baylor College Of Medicine Corporation Corporation 6500 Main Street, Suite 910 1120 NASA Parkway, Ste 505 1120 NASA Parkway, Ste 505 Houston, TX 77030-1402 Houston, TX 77058 Houston, TX 77058 [email protected] 281-702-6768 281-957-9173 ext #4618 [email protected] [email protected] Michel E. Loucks Taber MacCallum Jane Poynter Space Exploration Engineering Co. Paragon Space Development Paragon Space Development 687 Chinook Way Corporation Corporation Friday Harbor, WA 98250 3481 East Michigan Street 3481 East Michigan Street 360-378-7168 Tucson, AZ 85714 Tucson, AZ 85714 [email protected] 520-382-4815 520-382-4811 [email protected] [email protected] Thomas H. Squire S. Pete Worden Thermal Protection Materials Brig. Gen., USAF, Ret. NASA Ames Research Center NASA AMES Research Center Mail Stop 234-1 MS 200-1A Moffett Field, CA 94035-0001 Moffett Field, CA 94035 (650) 604-1113 650-604-5111 [email protected] [email protected] Abstract—In 1998 Patel et al searched for Earth-Mars free- To size the Environmental Control and Life Support System return trajectories that leave Earth, fly by Mars, and return to (ECLSS) we set the initial mission assumption to two crew Earth without any deterministic maneuvers after Trans-Mars members for 500 days in a modified SpaceX Dragon class of Injection.
    [Show full text]
  • Molecular Musings in Microbial Ecology and Evolution Rebecca J Case* and Yan Boucher*
    Case and Boucher Biology Direct 2011, 6:58 http://www.biology-direct.com/content/6/1/58 REVIEW Open Access Molecular musings in microbial ecology and evolution Rebecca J Case* and Yan Boucher* Abstract: A few major discoveries have influenced how ecologists and evolutionists study microbes. Here, in the format of an interview, we answer questions that directly relate to how these discoveries are perceived in these two branches of microbiology, and how they have impacted on both scientific thinking and methodology. The first question is “What has been the influence of the ‘Universal Tree of Life’ based on molecular markers?” For evolutionists, the tree was a tool to understand the past of known (cultured) organisms, mapping the invention of various physiologies on the evolutionary history of microbes. For ecologists the tree was a guide to discover the current diversity of unknown (uncultured) organisms, without much knowledge of their physiology. The second question we ask is “What was the impact of discovering frequent lateral gene transfer among microbes?” In evolutionary microbiology, frequent lateral gene transfer (LGT) made a simple description of relationships between organisms impossible, and for microbial ecologists, functions could not be easily linked to specific genotypes. Both fields initially resisted LGT, but methods or topics of inquiry were eventually changed in one to incorporate LGT in its theoretical models (evolution) and in the other to achieve its goals despite that phenomenon (ecology). The third and last question we ask is “What are the implications of the unexpected extent of diversity?” The variation in the extent of diversity between organisms invalidated the universality of species definitions based on molecular criteria, a major obstacle to the adaptation of models developed for the study of macroscopic eukaryotes to evolutionary microbiology.
    [Show full text]
  • 2006 Research Accomplishments
    International Space Station Research Accomplishments Overview Julie A. Robinson, Ph.D., ISS Program Scientist, NASA Outreach Seminar on the ISS United Nations February 2011 Outline • Why space research? And why on the International Space Station? • What has been done? • What are the most important results? • How have non-partners participated? 2 Disciplines that use the Laboratory • Biology & Biotechnology • Human Physiology & Performance • Physical Sciences • Technology Development & Demonstration • Earth and Space Science • Education 3 Biology: Animal Cells in Space m G Changes: Fluid distribution Gene expression signal transduction Locomotion Differentiation Metabolism 1 G Glycosylation 1 G Cytoskeleton Tissue morphogenesis Courtesy of Neal Pellis Biology: Plant Research in Space • Discovery potential for plant biology – Growth and development – Gravitropism, Circumnutation – Plant responses to the environment: light, temp, gases, soil – Stress responses – Stem cells/pluripotency • Plants as a food source • Plants for life support Moss grown in the dark On the Space Shuttle Earth Microgravity Soil structure Peas grown on ISS Biology: Microbes in Space More virulent Multiply more 3 modes of response rapidly No change Human Physiology: Response to Spaceflight Astronauts experience a •Neurovestibular spectrum of adaptations in flight and postflight •Cardiovascular •Bone •Muscle •Immunology Balance disorders •Nutrition Cardiovascular deconditioning Decreased immune function Muscle atrophy •Behavior Bone loss •Radiation ISS includes international
    [Show full text]
  • Linking the Development and Functioning of a Carnivorous Pitcher Plant’S Microbial Digestive Community
    The ISME Journal (2017) 11, 2439–2451 © 2017 International Society for Microbial Ecology All rights reserved 1751-7362/17 www.nature.com/ismej ORIGINAL ARTICLE Linking the development and functioning of a carnivorous pitcher plant’s microbial digestive community David W Armitage1,2 1Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA and 2Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA Ecosystem development theory predicts that successional turnover in community composition can influence ecosystem functioning. However, tests of this theory in natural systems are made difficult by a lack of replicable and tractable model systems. Using the microbial digestive associates of a carnivorous pitcher plant, I tested hypotheses linking host age-driven microbial community development to host functioning. Monitoring the yearlong development of independent microbial digestive communities in two pitcher plant populations revealed a number of trends in community succession matching theoretical predictions. These included mid-successional peaks in bacterial diversity and metabolic substrate use, predictable and parallel successional trajectories among microbial communities, and convergence giving way to divergence in community composition and carbon substrate use. Bacterial composition, biomass, and diversity positively influenced the rate of prey decomposition, which was in turn positively associated with a host leaf’s nitrogen uptake efficiency. Overall digestive performance was
    [Show full text]
  • Biodiversity and Ecosystem Functioning in Soil
    Article Lijbert Brussaard et al. Biodiversity and Ecosystem Functioning in Soil ognition of the pivotal role of the world's biota as the life-sup- We review the current knowledge on biodiversity in soils, port system for planet Earth, has revived interest in soil its role in ecosystem processes, its importance for human biodiversity as an asset to conserve, to understand and to man- purposes, and its resilience against stress and disturbance. age wisely in terms of its contribution to ecosystem services. The number of existing species is vastly higher than the The objective of this paper is to review the knowledge on the number described, even in the macroscopically visible diversity of soil biota and its role in ecosystem functioning, and taxa, and biogeographical syntheses are largely lacking. to identify key areas for future research. A major effort in taxonomy and the training of a new Although the diversity of soil organisms is worth conserving generation of systematists is imperative. This effort has to and studying in its own right, their functional roles offer a use- be focussed on the groups of soil organisms that, to the ful framework for making this effort more meaningful. We will best of our knowledge, play key roles in ecosystem functioning. To identify such groups, spheres of influence first define functional roles in a utilitarian way as ecosystem (SOI) of soil biota-such as the root biota, the shredders services. We will then have a closer look at what we mean by of organic matter and the soil bioturbators-are recognized biodiversity in soil, emphasizing spheres of influence (2; 'bio- that presumably control ecosystem processes, for logical systems of regulation' in 3) of the biota in soil and vari- example, through interactions with plants.
    [Show full text]