Biology Commons^™

Photoproduction Of Ammonium In The Southeastern Beaufort Sea And Its Biogeochemical Implications, H. Xie, S. Belanger, G. Song, Ronald Benner, A. Taalba, M. Blais, J. É. Tremblay, M. Babin

Faculty Publications

Photochemistry of dissolved organic matter (DOM) plays an important role in marine biogeochemical cycles, including the regeneration of inorganic nutrients. DOM photochemistry affects nitrogen cycling by converting bio-refractory dissolved organic nitrogen to labile inorganic nitrogen, mainly ammonium (NH₄⁺).During the August 2009 Mackenzie Light and Carbon (MALINA) Program, the absorbed photon-based efficiency spectra of NH₄⁺ photoproduction (i.e. photoammonification) were determined using water samples from the SE Beaufort Sea, including the Mackenzie River estuary, shelf, and Canada Basin. The photoammonification efficiency decreased with increasing wavelength across the ultraviolet and visible regimes and was higher in offshore waters …

A Molecular Perspective On The Ageing Of Marine Dissolved Organic Matter, R. Flerus, O. J. Lechtenfeld, B. P. Koch, S. L. Mccallister, P. Schmitt-Kopplin, Ronald Benner, G. Kattner

Faculty Publications

Dissolved organic matter (DOM) was extracted by solid-phase extraction (SPE) from 137 water samples from different climate zones and different depths along an eastern Atlantic Ocean transect. The extracts were analyzed with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI). Δ14C analyses were performed on subsamples of the SPE-DOM. In addition, the amount of dissolved organic carbon was determined for all water and SPE-DOM samples as well as the yield of amino sugars for selected samples. Linear correlations were observed between the magnitudes of 43 % of the FT-ICR mass peaks and the extract Δ14C …

Differential Responses Of Eastern Red-Backed Salamanders (Plethodon Cinereus) To Conspecifics And Centipedes, A. A. Burgett, Geoffrey R. Smith

Faculty Publications

No abstract provided.

Temporal Variation In The Abundance Of Poblana Alchichica In Near-Shore Habitat Of The High Elevation Lake, Lago De Alchichica, Puebla, Mexico, G. A. Woolrich-Pina, Geoffrey R. Smith, J. A. Lemos-Espinal, R. Montoya-Ayala, L. E. Avila-Bocanegra, E. B. Carduno

Faculty Publications

No abstract provided.

Coping Behaviour As An Adaptation To Stress: Post-Disturbance Preening In Colonial Seabirds, Shandelle M. Henson, Lynelle M. Weldon, James L. Hayward, Daniel Greene, Libby C. Megna, Maureen C. Serem

Faculty Publications

In humans, coping behaviour is an action taken to soothe oneself during or after a stressful or threatening situation. Some human behaviours with physiological functions also serve as coping behaviours, for example, comfort sucking in infants and comfort eating in adults. In birds, the behaviour of preening, which has important physiological functions, has been postulated to soothe individuals after stressful situations. We combine two existing modelling approaches – logistic regression and Darwinian dynamics – to explore theoretically how a behaviour with crucial physiological function might evolve into a coping behaviour. We apply the method to preening in colonial seabirds to …

The Rice Miniature Inverted Repeat Transposable Element Mping Is An Effective Insertional Mutagen In Soybean, C. Nathan Hancock, Feng Zhang, Kristen Floyd, Aaron O. Richardson, Peter Lafayette, Donna Tucker, Susan R. Wessler, Wayne A. Parrott

Faculty Publications

Insertional mutagenesis of legume genomes such as soybean (Glycine max) should aid in identifying genes responsible for key traits such as nitrogen fixation and seed quality. The relatively low throughput of soybean transformation necessitates the use of a transposon-tagging strategy where a single transformation event will produce many mutations over a number of generations. However, existing transposon-tagging tools being used in legumes are of limited utility because of restricted transposition (Ac/Ds: soybean) or the requirement for tissue culture activation (Tnt1: Medicago truncatula). A recently discovered transposable element from rice (Oryza …

Alterations In The Transciptome And Antibiotic Susceptibility Of Staphylococcus Aureus Grown In The Presence Of Diclofenac, James T. Riordan, Joanne M. Dupre, Stephanie A. Cantore-Matyi, Atul Kumar-Singh, Yang Song, Shahrear Zaman, Sonia Horan, Nada S. Helal, Vijayaraj Nagarajan, Mohamed O. Elasri, Brian J. Wilkinson, John E. Gustafson

Faculty Publications

Background

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) which has been shown to increase the susceptibility of various bacteria to antimicrobials and demonstrated to have broad antimicrobial activity. This study describes transcriptome alterations in S. aureus strain COL grown with diclofenac and characterizes the effects of this NSAID on antibiotic susceptibility in laboratory, clinical and diclofenac reduced-susceptibility (Dc^RS) S. aureus strains.

Methods

Transcriptional alterations in response to growth with diclofenac were measured using S. aureus gene expression microarrays and quantitative real-time PCR. Antimicrobial susceptibility was determined by agar diffusion MICs and gradient plate analysis. Ciprofloxacin accumulation was measured …

Multiplicity: An Organizing Principle For Cancers And Somatic Mutations, Lewis J. Frey, Stephen R. Piccolo, Mary E. Edgerton

Faculty Publications

Background: With the advent of whole-genome analysis for profiling tumor tissue, a pressing need has emerged for principled methods of organizing the large amounts of resulting genomic information. We propose the concept of multiplicity measures on cancer and gene networks to organize the information in a clinically meaningful manner. Multiplicity applied in this context extends Fearon and Vogelstein’s multi-hit genetic model of colorectal carcinoma across multiple cancers.

Methods: Using the Catalogue of Somatic Mutations in Cancer (COSMIC), we construct networks of interacting cancers and genes. Multiplicity is calculated by evaluating the number of cancers and genes linked by the measurement …

Copy Number Variants In Candidate Genes Are Genetic Modifiers Of Hirschsprung Disease, Qian Jiang, Yen Yi Ho, Li Hao, Courtney Nichols Berrios, Aravinda Chakravarti

Faculty Publications

Hirschsprung disease (HSCR) is a neurocristopathy characterized by absence of intramural ganglion cells along variable lengths of the gastrointestinal tract. The HSCR phenotype is highly variable with respect to gender, length of aganglionosis, familiality and the presence of additional anomalies. By molecular genetic analysis, a minimum of 11 neuro-developmental genes (RET, GDNF, NRTN, SOX10, EDNRB, EDN3, ECE1, ZFHX1B, PHOX2B, KIAA1279, TCF4) are known to harbor rare, high-penetrance mutations that confer a large risk to the bearer. In addition, two other genes (RET, NRG1) harbor common, low-penetrance polymorphisms that contribute only partially to risk and can act as genetic modifiers. To …

Aintegumenta And Aintegumenta-Like6 Regulate Auxin-Mediated Flower Development In Arabidopsis, Beth A. Krizek

Faculty Publications

Background: Two related genes encoding AP2/ERF-type transcription factors, AINTEGUMENTA (ANT) and AINTEGUMENTA-LIKE6 (AIL6), are important regulators of floral growth and patterning in Arabidopsis. Evidence suggests that these genes promote several aspects of flower development in response to auxin. To investigate the interplay of ANT, AIL6 and auxin during floral development, I have examined the phenotypic consequences of disrupting polar auxin transport in ant, ail6 and ant ail6 mutants by either genetic or chemical means.

Results: Plants containing mutations in ANT or AIL6 alone or in both genes together exhibit increased sensitivity to disruptions in polar auxin transport. …

Morphological Convergence During Pregnancy Among Predator And Nonpredator Populations Of The Livebearing Fish Brachyrhaphis Rhabdophora (Teleostei: Poeciliidae), Jeff S. Wesner, Eric J. Billman, Adam Meier, Mark C. Belk

Faculty Publications

Predation can drive morphological divergence in prey populations, although examples of divergent selection are typically limited to nonreproductive individuals. In livebearing females, shape often changes drastically during pregnancy, reducing speed and mobility and enhancing susceptibility to predation. In the present study, we document morphological divergence among populations of nonreproductive female livebearing fish (Brachyrhaphis rhabdophora) in predator and nonpredator environments. We then test the hypothesis that shape differences among nonreproductive females are maintained among reproductive females between predator and nonpredator environments. Nonreproductive females in predator environments had larger caudal regions and more fusiform bodies than females in nonpredator environments; …

Across Bacterial Phyla, Distantly-Related Genomes With Similar Genomic Gc Content Have Similar Patterns Of Amino Acid Usage, John Lightfield, Noah R. Fram, Bert Ely

Faculty Publications

The GC content of bacterial genomes ranges from 16% to 75% and wide ranges of genomic GC content are observed within many bacterial phyla, including both Gram negative and Gram positive phyla. Thus, divergent genomic GC content has evolved repeatedly in widely separated bacterial taxa. Since genomic GC content influences codon usage, we examined codon usage patterns and predicted protein amino acid content as a function of genomic GC content within eight different phyla or classes of bacteria. We found that similar patterns of codon usage and protein amino acid content have evolved independently in all eight groups of bacteria. …

Analysis Of Common And Specific Mechanisms Of Liver Function Affected By Nitrotoluene Compounds, Youping Deng, Sharon A. Meyer, Xin Guan, Barbara Lynn Escalon, Junmei Ai, Mitchell S. Wilbanks, Ruth Welti, Natàlia Garcia-Reyero, Edward J. Perkins

Faculty Publications

Background: Nitrotoluenes are widely used chemical manufacturing and munitions applications. This group of chemicals has been shown to cause a range of effects from anemia and hypercholesterolemia to testicular atrophy. We have examined the molecular and functional effects of five different, but structurally related, nitrotoluenes on using an integrative systems biology approach to gain insight into common and disparate mechanisms underlying effects caused by these chemicals.

Methodology/Principal Findings: Sprague-Dawley female rats were exposed via gavage to one of five concentrations of one of five nitrotoluenes [2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2ADNT) 4-amino-2,6-dinitrotoulene (4ADNT), 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT)] with necropsy …

The Evolution Of Multi-Component Visual Signals In Darters (Genus Etheostoma), Jennifer M. Gumm, Tamra C. Mendelson

Faculty Publications

As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evolution in multiple components of a complex courtship signal in darters, specifically addressing the question of how nuptial coloration evolves across different areas of the body. Using spectral reflectance, we defined 4 broad color classes present on the body and fins of 17 species of freshwater fishes (genus Etheostoma) and quantified differences in hue within each color class. Ancestral state reconstruction suggests that most color traits were expressed in …

Rotavirus Nsp4: Cell Type-Dependent Transport Kinetics To The Exofacial Plasma Membrane And Release From Intact Infected Cells, Thomas F. Gibbons, Stephen M. Storey, Cecelia V. Williams, Avery Mcintosh, Deanne M. Mitchel, Rebecca D. Parr, Friedhelm Schroeder, Judith M. Ball

Faculty Publications

Background

Rotavirus NSP4 localizes to multiple intracellular sites and is multifunctional, contributing to RV morphogenesis, replication and pathogenesis. One function of NSP4 is the induction of early secretory diarrhea by binding surface receptors to initiate signaling events. The aims of this study were to determine the transport kinetics of NSP4 to the exofacial plasma membrane (PM), the subsequent release from intact infected cells, and rebinding to naïve and/or neighboring cells in two cell types.

Methods

Transport kinetics was evaluated using surface-specific biotinylation/streptavidin pull-downs and exofacial exposure of NSP4 was confirmed by antibody binding to intact cells, and fluorescent resonant energy …

An Exotic Species Is The Favorite Prey Of A Native Enemy, Yiming Li, Zunwei Ke, Supen Wang, Geoffrey R. Smith, Xuan Liu

Faculty Publications

No abstract provided.

A Proposal For A Common Minimal Topic Set In Introductory Biology Courses For Majors, Eileen Gregory, Jane P. Ellis, Amanda N. Orenstein

Faculty Publications

A common complaint among instructors of introductory biology courses is the course covers too much material. Without a national consensus specifying which topics are essential, instructors are leery of excluding material. A survey was administered to Two-Year College and Four-Year College and University section members of the National Association of Biology Teachers (NABT) to identify the topics and skills college and university biology instructors believe students completing introductory biology should know and comprehend. Analysis identified a strong consensus for twenty topics and seven skills that should be included in all year-long introductory college biology course sequences for majors.

Possible Behavioral Avoidance Of Uv-B Radiation And Sunlight In Wood Frog (Lithobates Sylvaticus) Tadpoles, J. C. Connolly, B. L. Kress, Geoffrey R. Smith, Jessica E. Rettig

Faculty Publications

No abstract provided.

Distribution Of Tadpoles (Hyla Arenicolor) In The Pools Associated With The Rio Salado, Puebla, Mexico, G. A. Woolrich-Pina, J. A. Lemos-Espinal, Geoffrey R. Smith, R. Montoya-Ayala, Luis Oliver-López

Faculty Publications

No abstract provided.

Effects Of Elevation On Litter-Size Variation Among Lizard Populations In The Sceloporus Grammicus Complex (Phrynosomatidae) In Mexico, A. Ramirez-Bautista, A. Leyte-Manrique, J. C. Marshall, Geoffrey R. Smith

Faculty Publications

No abstract provided.

Distribution And Conservation Status Of Antillean Manatees (Trichechus Manatus Manatus) In Honduras, Daniel González-Socoloske, Cynthia R. Taylor, Olivia R. Rendon Thompson

Faculty Publications

The Antillean manatee, Trichechus manatus manatus, is among the most threatened mammals in Honduras, yet the last published study is from 1980. Since then, the North Coast of Honduras has experienced rapid population growth and land cover change possibly causing habitat loss for manatees. We conducted aerial, boat, and interview surveys between 2005-2007 along the northern and remote eastern coasts of Honduras to assess the current status and distribution of manatees. In addition, we compiled all available data on manatee mortality from museum specimens, unpublished reports, and interviews to determine current threats. We averaged 1.2 manatee sightings per survey hour …

Diets Of Three Species Of Bufonids (Amphibia, Anura) From Northern Mexico, Geoffrey R. Smith, J. A. Lemos-Espinal, A. B. Burner, K. E. Winter, C. B. Dayer

Faculty Publications

No abstract provided.

Effects Of Mosquitofish (Gambusia Affinis) Cues On Wood Frog (Lithobates Sylvaticus) Tadpole Activity, K. F. Buttermore, P. N. Litkenhaus, D. C. Torpey, Geoffrey R. Smith, Jessica E. Rettig

Faculty Publications

No abstract provided.

Body Temperatures Of Hyla Arenicolor From Sierra De Tepozotlan, Estado De Mexico, Mexico, F. Correa-Sanchez, Geoffrey R. Smith, G. A. Woolrich-Pina, J. A. Lemos-Espinal

Faculty Publications

No abstract provided.

The Effects Of Temperature And Salinity On Wood Frog (Lithobates Sylvaticus) Tadpole Growth And Survival, J. H. Clemmer, E. Z. Miller, Geoffrey R. Smith, Jessica E. Rettig

Faculty Publications

No abstract provided.

The Mathematics Of Animal Behavior: An Interdisciplinary Dialogue, Shandelle M. Henson, James L. Hayward

Faculty Publications

No abstract provided.

Structures Of Human Thymidylate Synthase R163k With Dump, Fdump And Glutathione Show Asymmetric Ligand Binding, Lydia M. Gibson, Lesa R. Celeste, Leslie L. Lovelace, Lukasz Lebioda

Faculty Publications

Thymidylate synthase (TS) is a well validated target in cancer chemotherapy. Here, a new crystal form of the R163K variant of human TS (hTS) with five subunits per asymmetric part of the unit cell, all with loop 181-197 in the active conformation, is reported. This form allows binding studies by soaking crystals in artificial mother liquors containing ligands that bind in the active site. Using this approach, crystal structures of hTS complexes with FdUMP and dUMP were obtained, indicating that this form should facilitate high-throughput analysis of hTS complexes with drug candidates. Crystal soaking experiments using oxidized glutathione revealed that …

Repression Of Wnt Signaling By A Fer-Type Nonreceptor Tyrosine Kinase, Aaron P. Putzke, Joel H. Rothman

Faculty Publications

The Wnt signaling pathway must be properly modulated to ensure an appropriate output: pathological conditions result from either insufficient or excessive levels of Wnt signal. For example, hyperactivation of the Wnt pathway is associated with various cancers and subnormal Wnt signaling can lead to increased invasiveness of tumor cells. We found that the Caenorhabditis elegans ortholog of the Fer nonreceptor tyrosine kinase, FRK-1, limits Wnt signaling by preventing the adhesion complex-associated beta-catenin, HMP-2, from participating in Wnt-dependent specification of the endoderm during embryogenesis. Removal of FRK-1 function results in relocalization of HMP-2 to the nucleus of epidermal cells, and allows …

Glutamine Synthetase Partitioning In Native And Introduced Salt Marsh Grasses, Eric L.G. Hazelton, Thomas J. Knight Phd, Theresa A. Theodose Phd

Faculty Publications

Plants with higher glutamine synthetase (GS) activity in photosynthetic tissues than below-ground structures (high leaf:root [L:R] GS activity) show growth advantages over plants with a low L:R GS activity ratio. The benefits of a high L:R GS activity ratio are well documented in agricultural systems, but little is known about the ecology of GS partitioning in natural systems. To determine the ecological significance of GS partitioning, we measured above- and below-ground GS activity in Spartina grasses field-collected from a Maine salt marsh and others raised in a growth chamber from seed. The more stress-tolerant, faster growing S. alterniflora had a …

Weeds In The Flower Garden: An Exploration Of Plagiarism In Graduate Students’ Research Proposals And Its Connection To Enculturation, Esl, And Contextual Factors, Joanna Gilmore, Denise Strickland, Briana Eileen Timmerman, Michelle Maher, David Feldon

Faculty Publications

Existing literature provides insight into the nature and extent of plagiarism amongst undergraduate students (e.g., Ellery, 2008; Parameswaran & Devi, 2006; Selwyn, 2008). Plagiarism amongst graduate students is relatively unstudied, however, and the existing data are largely based on self-reports. This study investigated the rates and potential causes of plagiarism amongst graduate students in master’s and doctoral programmes in science, technology, engineering, mathematics, and science or mathematics education by examining actual research proposals written by graduate students. Results indicate that plagiarism is a prevalent issue at each of the three university sites sampled and across all of the investigated disciplines. …