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2017

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Articles 571 - 600 of 1882

Full-Text Articles in Biology

Foliar Mineral Accumulation Patterns Of Gypsophiles And Their Relatives From The Usa And Spain, Clare Muller Jul 2017

Foliar Mineral Accumulation Patterns Of Gypsophiles And Their Relatives From The Usa And Spain, Clare Muller

Masters Theses

Gypsum endemism in plants (gypsophily) is common on gypsum outcrops worldwide, but little is known about the functional ecology of Chihuahuan Desert gypsophiles. We investigated whether leaf chemistry of gypsophile lineages from the northern Chihuahuan Desert are similar to leaves of related non-endemic (gypsovag) species relative to their soil chemistry. We expected widely-distributed gypsophiles, hypothesized to be older lineages on gypsum, would have distinct leaf chemistry from narrowly-distributed, relatively younger lineages endemic to gypsum and gypsovags, reflecting adaptation to gypsum. We collected leaves from 23 gypsophiles and related non-endemic taxa growing on non-gypsum soils. Soils and leaves were analyzed for …


Review Of The Sub-Saharan Africa Species Of Dignomus And Phylogenetic Analysis Of The Bostrichoids (Coleoptera: Bostrichoidea: Ptinidae), Amelia Lesbeth Smith Jul 2017

Review Of The Sub-Saharan Africa Species Of Dignomus And Phylogenetic Analysis Of The Bostrichoids (Coleoptera: Bostrichoidea: Ptinidae), Amelia Lesbeth Smith

Masters Theses & Specialist Projects

Sub-Saharan Africa is home to nine described species of Dignomus Wollaston, 1862. Study and dissection of specimens has led me to the hypothesis that there are nine undocumented species in this region. Descriptions and images of the new species are presented and discussed, along with a compiled list of all described species from the Sub- Saharan region. The probable biology as geographic distributions for members of the genus are also given.

Additionally, a phylogenetic analysis of 95 species of bostrichoids using CO1 molecular data was done with a focus on the origins of Dignomus and Pseudomezium. parsimony and bayesian analyses …


Reply To Marques Et Al. (2017): How To Best Handle Potential Detectability Bias, Richard L. Hutto Jul 2017

Reply To Marques Et Al. (2017): How To Best Handle Potential Detectability Bias, Richard L. Hutto

Biological Sciences Faculty Publications

Marques et al. (2017) write in response to a communications paper in which I (Hutto 2016) question whether a model-based approach is the only way to deal with the detectability problem inherent in bird survey work. The model-based approach to dealing with potential detectability bias is widely viewed as the operational gold standard, and I welcome the comments from experts in this field. The authors did uncover some errors on my part, which I address below, but they also misrepresented my most important points, so I am glad to have the opportunity to respond here. [1st paragraph]


Too Important To Tamper With: Predation Risk Affects Body Mass And Escape Behaviour But Not Escape Ability, Benjamin T. Walters, Tin Nok Natalie Cheng, Justin Doyle, Chistopher G. Guglielmo, Michael Clinchy, Liana Y. Zanette Jul 2017

Too Important To Tamper With: Predation Risk Affects Body Mass And Escape Behaviour But Not Escape Ability, Benjamin T. Walters, Tin Nok Natalie Cheng, Justin Doyle, Chistopher G. Guglielmo, Michael Clinchy, Liana Y. Zanette

Biology Publications

Escaping from a predator is a matter of life or death, and prey are expected to adaptively alter their physiology under chronic predation risk in ways that may affect escape. Theoretical models assume that escape performance is mass dependent, whereby scared prey strategically maintain an optimal body mass to enhance escape. Experiments testing the mass-dependent predation risk hypothesis have demonstrated that prior experience of predation risk can affect body mass, and the behavioural decisions about evasive actions to take. Other studies on natural changes in body mass indicate that mass can affect escape. No single experiment has tested if all …


Draft Genome Sequence Of Staphylococcus Epidermidis (Winslow And Winslow) Evans (Atcc 14990), Catherine Putonti, Laurynas Kalesinskas, Evan Cudone, Alan J. Wolfe, Kathleen C. Engelbrecht, David W. Koenig Jul 2017

Draft Genome Sequence Of Staphylococcus Epidermidis (Winslow And Winslow) Evans (Atcc 14990), Catherine Putonti, Laurynas Kalesinskas, Evan Cudone, Alan J. Wolfe, Kathleen C. Engelbrecht, David W. Koenig

Biology: Faculty Publications and Other Works

Here, we report the draft genome sequence for the type strain Staphylococcus epidermidis (Winslow and Winslow) Evans (ATCC 14990). The assembly consisted of 2,457,519 bp with an observed G+C content of 32.04%. Thirty-seven contigs were produced, including two putative plasmids, with a 296.8× coverage and an N50 of 180,848 bp.


Risk-Averse Personalities Have A Systemically Potentiated Neuroendocrine Stress Axis: A Multilevel Experiment In Parus Major, Alexander T. Baugh, Rebecca A. Senft , '15, Marian L. Firke , '14, Abigail P. Lauder , '15, J. Schroeder, S. L. Meddle, Kees Van Oers, M. Hau Jul 2017

Risk-Averse Personalities Have A Systemically Potentiated Neuroendocrine Stress Axis: A Multilevel Experiment In Parus Major, Alexander T. Baugh, Rebecca A. Senft , '15, Marian L. Firke , '14, Abigail P. Lauder , '15, J. Schroeder, S. L. Meddle, Kees Van Oers, M. Hau

Biology Faculty Works

Hormonal pleiotropy—the simultaneous influence of a single hormone on multiple traits—has been hypothesized as an important mechanism underlying personality, and circulating glucocorticoids are central to this idea. A major gap in our understanding is the neural basis for this link. Here we examine the stability and structure of behavioral, endocrine and neuroendocrine traits in a population of songbirds (Parus major). Upon identifying stable and covarying behavioral and endocrine traits, we test the hypothesis that risk-averse personalities exhibit a neuroendocrine stress axis that is systemically potentiated—characterized by stronger glucocorticoid reactivity and weaker negative feedback. We show high among-individual variation and covariation …


Cache Valley Resident Exposure To Pm2.5, Kristina Krepinski Jul 2017

Cache Valley Resident Exposure To Pm2.5, Kristina Krepinski

Undergraduate Honors Capstone Projects

Air pollution poses one of the largest environmental risks to human health, and greatly contributes to increased mortality within populations. Of the different types of pollutants, fine particulate matter (PM2.5) has the most adverse health effects. Long-term exposure to PM2.5 is known to have serious health outcomes; however, evidence has indicated that even short-term exposure to moderate concentrations of PM2.5 is detrimental to human health. While PM2.5 does contribute to various respiratory conditions by affecting lung function, it also significantly affects the cardiovascular system. Elevated PM2.5 exposure increases risk for cardiovascular disease, congestive heart …


Geographic Strain Differentiation Of Schistosoma Japonicum In The Philippines Using Microsatellite Markers, Kharleezelle J. Moendeg Jul 2017

Geographic Strain Differentiation Of Schistosoma Japonicum In The Philippines Using Microsatellite Markers, Kharleezelle J. Moendeg

Biology Faculty Publications

Background

Microsatellites have been found to be useful in determining genetic diversities of various medically-important parasites which can be used as basis for an effective disease management and control program. In Asia and Africa, the identification of different geographical strains of Schistosoma japonicum, S. haematobium and S. mansoni as determined through microsatellites could pave the way for a better understanding of the transmission epidemiology of the parasite. Thus, the present study aims to apply microsatellite markers in analyzing the populations of S. japonicum from different endemic areas in the Philippines for possible strain differentiation.

Methodology/ Principal …


Sexual Selection And Sex Ratios In Anolis Lizards, Pavitra Muralidhar, Michele A. Johnson Jul 2017

Sexual Selection And Sex Ratios In Anolis Lizards, Pavitra Muralidhar, Michele A. Johnson

Biology Faculty Research

Biased sex ratios, or unequal numbers of males and females in a population, can alter the intensity of sexual selection by enhancing competition for mates, and thus may affect the evolution of reproductive strategies. Studies of sex ratio variation across a clade provide an opportunity to examine the morphological or behavioral consequences of different levels of sexual selection. We examined sex ratio variation, using phylogenetic comparative methods, across a diverse clade of terrestrial vertebrates, the Anolis lizards. Across a sample of 14 species in 21 localities, we found remarkable bidirectional variation in sex ratios across the Anolis clade: males are …


Response To Drought Of A Stream Fish Assemblage In A High Elevation Stream In The Intermountain West, Richard M. Simkins Jul 2017

Response To Drought Of A Stream Fish Assemblage In A High Elevation Stream In The Intermountain West, Richard M. Simkins

Theses and Dissertations

One of the most influential disturbances for stream fish assemblages is large-scale declines in flow caused by periods of drought. Although stream characteristics are known to influence the response of stream fishes to drought, we asked if ecological traits of stream fishes determine, in part, their population level response to drought. To test for ecological trait-based responses to drought in a stream fish assemblage, we quantified species abundances over a period of 5 years that represented a wet to dry period. We sampled stream fishes in Yellow Creek, Wyoming, USA, a high elevation stream dependent on snow-storage for most of …


To Stress Or Not To Stress: Physiological Responses To Tetrodotoxin In Resistant Garter Snakes Vary By Sex, Lorin A. Neuman-Lee, Edmund D. Brodie Jr., Tyler Hansen, Edmund D. Brodie Jr., Susannah S. French Jul 2017

To Stress Or Not To Stress: Physiological Responses To Tetrodotoxin In Resistant Garter Snakes Vary By Sex, Lorin A. Neuman-Lee, Edmund D. Brodie Jr., Tyler Hansen, Edmund D. Brodie Jr., Susannah S. French

Biology Faculty Publications

The activation of the hypothalamic pituitary adrenal (HPA) axis is one of the most important physiological processes in coping with any deviation in an organism’s homeostasis. This activation and the secretion of glucocorticoids, such as corticosterone, allow organisms to cope with perturbations and return to optimal physiological functioning as quickly as possible. In this study, we examined the HPA axis activation in common gartersnakes (Thamnophis sirtalis) as a response to a natural toxin, tetrodotoxin (TTX). This neurotoxin is found in high levels in the Rough-skinned Newt (Taricha granulosa), which is a prey item for these snakes. …


Sex Differences In The Drinking Response To Angiotensin Ii (Angii): Effect Of Body Weight, Jessica Santollo, Ann-Marie Torregrossa, Derek Daniels Jul 2017

Sex Differences In The Drinking Response To Angiotensin Ii (Angii): Effect Of Body Weight, Jessica Santollo, Ann-Marie Torregrossa, Derek Daniels

Biology Faculty Publications

Sex differences in fluid intake stimulated by angiotensin II (AngII) have been reported, but the direction of the differences is inconsistent. To resolve these discrepancies, we measured water intake by male and female rats given AngII. Males drank more than females, but when intake was normalized to body weight, the sex difference was reversed. Weight-matched males and females, however, had no difference in intake. Using a linear mixed model analysis, we found that intake was influenced by weight, sex, and AngII dose. We used linear regression to disentangle these effects further. Comparison of regression coefficients revealed sex and weight differences …


Counterintuitive Roles Of Experience And Weather On Migratory Performance, Adrian I. Rus, Adam E. Duerr, Tricia A. Miller, James R. Belthoff, Todd Katzner Jul 2017

Counterintuitive Roles Of Experience And Weather On Migratory Performance, Adrian I. Rus, Adam E. Duerr, Tricia A. Miller, James R. Belthoff, Todd Katzner

Biology Faculty Publications and Presentations

Migration allows animals to live in resource-rich but seasonally variable environments. Because of the costs of migration, there is selective pressure to capitalize on variation in weather to optimize migratory performance. To test the degree to which migratory performance (defined as speed of migration) of Golden Eagles (Aquila chrysaetos) was determined by age- and season-specific responses to variation in weather, we analyzed 1,863 daily tracks (n = 83 migrant eagles) and 8,047 hourly tracks (n = 83) based on 15 min GPS telemetry data from Golden Eagles and 277 hourly tracks based on 30 s data …


Blurred Lines Between Competition And Parasitism, Tara E. Stewart, Stefan A. Schnitzer Jul 2017

Blurred Lines Between Competition And Parasitism, Tara E. Stewart, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Accurately describing the ecological relationships between species is more than mere semantics-doing so has profound practical and applied implications, not the least of which is that inaccurate descriptions can lead to fundamentally incorrect predicted outcomes of community composition and functioning. Accurate ecological classifications are particularly important in the context of global change, where species interactions can change rapidly following shifts in species composition. Here, we argue that many common ecological interactions-particularly competition and parasitism-can be easily confused and that we often lack empirical evidence for the full reciprocal interaction among species. To make our case and to propose a theoretical …


Draft Genome Sequence Of Escherichia Coli K-12 (Atcc 29425), Catherine Putonti, Kathleen C. Engelbrecht, David W. Koenig, Alan J. Wolfe Jul 2017

Draft Genome Sequence Of Escherichia Coli K-12 (Atcc 29425), Catherine Putonti, Kathleen C. Engelbrecht, David W. Koenig, Alan J. Wolfe

Biology: Faculty Publications and Other Works

A draft genome sequence for Escherichia coli ATCC 29425 was investigated. The size of the genome was 4,608,319 bp, with an observed G+C content of 50.68%. This assembly consisted of 80 contigs, with an average coverage of 122.2×, including one contig representative of the complete genome for the temperate phage P1.


Draft Genome Sequences Of Two Atcc Staphylococcus Aureus Subsp. Aureus Strains, Catherine Putonti, Laurynas Kalesinskas, Evan Cudone, Kathleen C. Engelbrecht, David W. Koenig, Alan J. Wolfe Jul 2017

Draft Genome Sequences Of Two Atcc Staphylococcus Aureus Subsp. Aureus Strains, Catherine Putonti, Laurynas Kalesinskas, Evan Cudone, Kathleen C. Engelbrecht, David W. Koenig, Alan J. Wolfe

Biology: Faculty Publications and Other Works

Draft genome sequences for Staphylococcus aureus subsp. aureus Rosenbach ATCC 14458 and ATCC 27217 strains were investigated. The genome sizes were 2,880,761 bp and 2,759,100 bp, respectively. Strain ATCC 14458 was assembled into 39 contigs, including 3 plasmids, and strain ATCC 27217 was assembled into 25 contigs, including 2 plasmids.


Essentials Of Biology I & Ii (Gsw), Stephanie Harvey, Ian Brown, Otto Lorenz, Thomas Wright, Anh-Hue Thi Tu, Yonnie Williams Jul 2017

Essentials Of Biology I & Ii (Gsw), Stephanie Harvey, Ian Brown, Otto Lorenz, Thomas Wright, Anh-Hue Thi Tu, Yonnie Williams

Biological Sciences Grants Collections

This Grants Collection for Essentials of Biology was created under a Round Four ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

  • Linked Syllabus
  • Initial Proposal
  • Final Report


Introduction To Biological Principles (Georgia Tech), Chrissy Spencer, Jung Choi, Shana Kerr Jul 2017

Introduction To Biological Principles (Georgia Tech), Chrissy Spencer, Jung Choi, Shana Kerr

Biological Sciences Grants Collections

This Grants Collection for Introduction to Biological Principles was created under a Round Three ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

  • Linked Syllabus
  • Initial Proposal
  • Final Report


Foundations Of Biology (Ghc), Tom Harnden, Sharryse Henderson, Andrew Dawson, Jason Christian, Greg Ford, Christin Collins Jul 2017

Foundations Of Biology (Ghc), Tom Harnden, Sharryse Henderson, Andrew Dawson, Jason Christian, Greg Ford, Christin Collins

Biological Sciences Grants Collections

This Grants Collection for Foundations of Biology was created under a Round Five ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

  • Linked Syllabus
  • Initial Proposal
  • Final Report


Role Of Terrestrial Organic Matter In Food Webs Of The Rocky Intertidal Zone, Douglas O. Fairbanks Jul 2017

Role Of Terrestrial Organic Matter In Food Webs Of The Rocky Intertidal Zone, Douglas O. Fairbanks

Theses and Dissertations

Terrestrial organic matter (TOM) constitutes an important source of energy in many aquatic environments (streams, lakes, wetlands). This is the first study to examine the role of TOM in food webs of the rocky intertidal zone. We compared the consumption of red alder leaves (Alnus rubra) to common marine sources of drifting detritus along the southern Oregon coast (Nereocystis luetkeana, Phyllospadix spp., and Fucus gardneri). We used short term (hours to days) and long term (months) feeding experiments to compare the rate of consumption among each plant species during the Spring and Fall of 2014 …


The Implications Of Eco-Evolutionary Processes For The Emergence Of Marine Plankton Community Biogeography, Boris Sauterey, Ben Ward, Jonathan Rault, Chris Bowler, David Claessen Jul 2017

The Implications Of Eco-Evolutionary Processes For The Emergence Of Marine Plankton Community Biogeography, Boris Sauterey, Ben Ward, Jonathan Rault, Chris Bowler, David Claessen

Entomology Faculty Publications

Models of community assembly have been used to illustrate how the many functionally diverse species that compose plankton food webs can coexist. However, the evolutionary processes leading to the emergence of plankton food webs and their interplay with migratory processes and spatial heterogeneity are yet to be explored. We study the eco-evolutionary dynamics of a modeled plankton community structured in both size and space and physiologically constrained by empirical data. We demonstrate that a complex yet ecologically and evolutionarily stable size-structured food web can emerge from an initial set of two monomorphic phytoplankton and zooplankton populations. We also show that …


A Genomics Education Alliance, Sarah C.R. Elgin, Gita Bangera, Vincent Buonaccorsi, Douglas L. Chalker, Elizabeth Dinsdale, Erin L. Dolan, Linnea Fletcher, Arthur G. Hunt, Carolyn Lawrence-Dill, Wilson Leung, Laura Reed, Anne Rosenwald, Sandesh Subramanya, Emily Wiley, Jason Williams Jul 2017

A Genomics Education Alliance, Sarah C.R. Elgin, Gita Bangera, Vincent Buonaccorsi, Douglas L. Chalker, Elizabeth Dinsdale, Erin L. Dolan, Linnea Fletcher, Arthur G. Hunt, Carolyn Lawrence-Dill, Wilson Leung, Laura Reed, Anne Rosenwald, Sandesh Subramanya, Emily Wiley, Jason Williams

Biology Faculty Research

Scientists are sequencing new genomes at an increasing rate with the goal of associating genome contents with phenotypic traits. After a new genome is sequenced and assembled, structural gene annotation is often the first step in analysis. Despite advances in computational gene prediction algorithms, most eukaryotic genomes still benefit from manual gene annotation. Undergraduates can become skilled annotators, and in the process learn both about genes/genomes and about how to utilize large datasets. Data visualizations provided by a genome browser are essential for manual gene annotation, enabling annotators to quickly evaluate multiple lines of evidence (e.g., sequence similarity, RNA-Seq, gene …


The Tension-Sensitive Ion Transport Activity Of Msl8 Is Critical For Its Function In Pollen Hydration And Germination, Eric S. Hamilton Jul 2017

The Tension-Sensitive Ion Transport Activity Of Msl8 Is Critical For Its Function In Pollen Hydration And Germination, Eric S. Hamilton

Biology Faculty Research

All cells respond to osmotic challenges, including those imposed during normal growth and development. Mechanosensitive (MS) ion channels provide a conserved mechanism for regulating osmotic forces by conducting ions in response to increased membrane tension. We previously demonstrated that the MS ion channel MscS-Like 8 (MSL8) is required for pollen to survive multiple osmotic challenges that occur during the normal process of fertilization, and that it can inhibit pollen germination. However, it remained unclear whether these physiological functions required ion flux through a mechanically gated channel provided by MSL8. We introduced two point mutations into the predicted pore-lining domain of …


The Role Of N-Acetylcysteine Amide In Defending Primary Human Retinal Pigment Epithelial Cells Against Tert-Butyl Hydroperoxide-Induced Oxidative Stress, Hsiu-Jen Wang, Yue-Wern Huang, Shakila B. Tobwala, Annelise Pfaff, Robert Aronstam, Nuran Ercal Jul 2017

The Role Of N-Acetylcysteine Amide In Defending Primary Human Retinal Pigment Epithelial Cells Against Tert-Butyl Hydroperoxide-Induced Oxidative Stress, Hsiu-Jen Wang, Yue-Wern Huang, Shakila B. Tobwala, Annelise Pfaff, Robert Aronstam, Nuran Ercal

Biological Sciences Faculty Research & Creative Works

Background: Age-related macular degeneration (AMD) is a leading cause of blindness in the United States among adults age 60 and older. While oxidative stress is implicated in the pathogenesis of AMD, dietary antioxidants have been shown to delay AMD progression in clinical studies. We hypothesized that N-acetylcysteine amide (NACA), a thiol antioxidant, would protect retinal pigment epithelium and impede progression of retinal degeneration.

Methods: tert-Butyl hydroperoxide (TBHP) was used to induce oxidative stress in cell cultures. The goal was to evaluate the efficacy of NACA in an in vitro model of AMD in primary human retinal pigment epithelial cells …


Oxidative Insults Disrupt Mitochondrial Dynamics, Iraselia A. Garcia Jul 2017

Oxidative Insults Disrupt Mitochondrial Dynamics, Iraselia A. Garcia

Theses and Dissertations

Mitochondria form an organellar network to provide ATP to the cell. Mitochondrial DNA (mtDNA) combines with nuclear DNA to encode polypeptides critical to forming the complexes of oxidative phosphorylation in the mitochondrial inner membrane, which generate a transmembrane potential (ΔΨm) to synthesize ATP. This ΔΨm is required to maintain mitochondria fission/fusion dynamics: organellar fusion (mediated by OPA1) and fission events (mediated by DRP1) coordinately regulate mitochondrial dynamics. While oxidative stress correlates with mitochondrial dysfunction, it is unclear how oxidants affect mitochondrial structure/function homeostasis. This project seeks to establish and examine the impact of reactive oxygen species (ROS) on mitochondrial dynamics. …


Effectiveness Of The Flipped Classroom Model In Anatomy And Physiology Laboratory Courses At A Hispanic Serving Institution, Gerardo Sanchez Jul 2017

Effectiveness Of The Flipped Classroom Model In Anatomy And Physiology Laboratory Courses At A Hispanic Serving Institution, Gerardo Sanchez

Theses and Dissertations

A flipped laboratory model involves significant preparation by the students on lab material prior to entry to the laboratory. This allows laboratory time to be focused on active learning through experiments. The aim of this study was to observe changes in student performance through the transition from a traditional laboratory format, to a flipped format. The data showed that for both Anatomy and Physiology (I and II) laboratories a more normal distribution of grades was observed once labs were flipped and lecture grade averages increased. Chi square and analysis of variance tests showed grade changes to a statistically significant degree, …


The Noncanonical Roles Of Two Primordial Molecules In Flagella, Xiaoyan Zhu Jul 2017

The Noncanonical Roles Of Two Primordial Molecules In Flagella, Xiaoyan Zhu

Dissertations (1934 -)

Motile cilia and flagella are ancient organelles that eukaryotic organisms today still rely on to thrive in their natural environment. Not surprisingly, accumulated evidence has shown that the intricate motility machinery, the microtubule-based axoneme, is evolutionarily conserved down to the molecular level. This notion is epitomized by the signature axonemal complex, the radial spoke (RS). The RS is part of a control center conferring the high frequency and tightly regulated movement. Key RS proteins discovered in biflagellate green alga, Chlamydomonas reinhardtii, are also generated by nearly all ciliated organisms, including Homo sapiens. Among them are two subunits from primordial protein …


Abundance And Distribution Of Microbial Cells And Viruses In An Alluvial Aquifer, Donald Pan, Jason Nolan, Kenneth H. Williams, Karrie A. Weber Jul 2017

Abundance And Distribution Of Microbial Cells And Viruses In An Alluvial Aquifer, Donald Pan, Jason Nolan, Kenneth H. Williams, Karrie A. Weber

School of Biological Sciences: Faculty Publications

Viruses are the most abundant biological entity on Earth and their interactions with microbial communities are recognized to influence microbial ecology and impact biogeochemical cycling in various ecosystems. While the factors that control the distribution of viruses in surface aquatic environments are well-characterized, the abundance and distribution of continental subsurface viruses with respect to microbial abundance and biogeochemical parameters have not yet been established. In order to begin to understand the factors governing virus distribution in subsurface environments, we assessed microbial cell and virus abundance in groundwater concurrent with groundwater chemistry in a uranium impacted alluvial aquifer adjoining the Colorado …


How Question Types Reveal Student Thinking: An Experimental Comparison Of Multiple-True-False And Free-Response Formats, Joanna K. Hubbard, Macy A. Potts, Brian A. Couch Jul 2017

How Question Types Reveal Student Thinking: An Experimental Comparison Of Multiple-True-False And Free-Response Formats, Joanna K. Hubbard, Macy A. Potts, Brian A. Couch

School of Biological Sciences: Faculty Publications

Assessments represent an important component of undergraduate courses because they affect how students interact with course content and gauge student achievement of course objectives. To make decisions on assessment design, instructors must understand the affordances and limitations of available question formats. Here, we use a crossover experimental design to identify differences in how multiple-true-false (MTF) and free-response (FR) exam questions reveal student thinking regarding specific conceptions. We report that correct response rates correlate across the two formats but that a higher percentage of students provide correct responses for MTF questions. We find that MTF questions reveal a high prevalence of …


Identification Of The Atpase Subunit Of The Primary Maltose Transporter In The Hyperthermophilic Anaerobe Thermotoga Maritima, Raghuveer Singh, Derrick White, Paul H. Blum Jul 2017

Identification Of The Atpase Subunit Of The Primary Maltose Transporter In The Hyperthermophilic Anaerobe Thermotoga Maritima, Raghuveer Singh, Derrick White, Paul H. Blum

School of Biological Sciences: Faculty Publications

Thermotoga maritima is a hyperthermophilic anaerobic bacterium that produces molecular hydrogen (H2) by fermentation. It catabolizes a broad range of carbohydrates through the action of diverse ABC transporters. However, in T. maritima and related species, highly similar genes with ambiguous annotation obscure a precise understanding of genome function. In T. maritima, three putative malK genes, all annotated as ATPase subunits, exhibited high identity to each other. To distinguish between these genes, malK disruption mutants were constructed by gene replacement, and the resulting mutant cell lines were characterized. Only a disruption of malK3 produced a defect in maltose …