Life Sciences Commons^™

Impact Of Hydration Status On Electromyography And Ratings Of Perceived Exertion During The Vertical Jump, Paul T. Donahue, Samuel J. Wilson, Charles C. Williams, Melinda Valliant, John C. Garner

Faculty Publications

Background: The vertical jumping task is commonly used to assess lower-body power output in athletic populations, in addition to being commonly used to during investigations of hydration and anaerobic performance. Changes in neuromuscular function during a hypohydrated state have been proposed as a potential mechanism to decreases in anaerobic performance.

Objectives: The primary purpose of this investigation was to examine the impact of hydration state on electromyography during the vertical jumping task.

Methods: Twenty recreationally trained males were tested in three hydration conditions (hypohydrated, euhydrated, and control). Testing included maximal voluntary contractions of the vastus lateralis, vastus …

Current Understanding Of West Nile Virus Clinical Manifestations, Immune Responses, Neuroinvasion, And Immunotherapeutic Implications, Fengwei Bai, E. Ashley Thompson, Parminder J.S. Vig, A. Arturo Leis

Faculty Publications

West Nile virus (WNV) is the most common mosquito-borne virus in North America. WNV-associated neuroinvasive disease affects all ages, although elderly and immunocompromised individuals are particularly at risk. WNV neuroinvasive disease has killed over 2300 Americans since WNV entered into the United States in the New York City outbreak of 1999. Despite 20 years of intensive laboratory and clinical research, there are still no approved vaccines or antivirals available for human use. However, rapid progress has been made in both understanding the pathogenesis of WNV and treatment in clinical practices. This review summarizes our current understanding of WNV infection in …

Scl: A Lattice-Based Approach To Infer 3d Chromosome Structures From Single-Cell Hi-C Data, Hao Zhu, Zheng Wang

Student Publications

Motivation: In contrast to population-based Hi-C data, single-cell Hi-C data are zero-inflated and do not indicate the frequency of proximate DNA segments. There are a limited number of computational tools that can model the 3D structures of chromosomes based on single-cell Hi-C data.

Results: We developed single-cell lattice (SCL), a computational method to reconstruct 3D structures of chromosomes based on single-cell Hi-C data. We designed a loss function and a 2 D Gaussian function specifically for the characteristics of single-cell Hi-C data. A chromosome is represented as beads-on-a-string and stored in a 3 D cubic lattice. Metropolis–Hastings simulation …

Parasitic Microbiome Project: Grand Challenges, Nolwenn M. Dheilly, Joaquín Martínez Martínez, Karyna Rosario, Paul J. Brindley, Raina N. Fichorava, Jonathan Z. Kaye, Kevin D. Kohl, Laura J. Knoll, Julius Lukeš, Susan L. Perkins, Robert Poulin, Lynn Schriml, Luke R. Thompson

Faculty Publications

No abstract provided.

Late Pleistocene Range Expansion Of North American Topminnows Accompanied By Admixture And Introgression, David D. Duvernell, Eric Westhafer, Jacob F. Schaefer

Faculty Publications

Aim: We used genome‐scale sampling to assess the phylogeography of a group of topminnows in the Fundulus notatus species complex. Two of the species have undergone extensive range expansions resulting in broadly overlapping distributions, and sympatry within drainages has provided opportunities for hybridization and introgression. We assessed the timing and pattern of range expansion in the context of late Pleistocene–Holocene drainage events and evaluated the evidence for introgressive hybridization between species.

Location: Central and southern United States including drainages of the Gulf of Mexico Coastal Plain and portions of the Mississippi River drainage in and around the Central …

Food Consumption Patterns And Body Composition In Children: Moderating Effects Of Prop Taster Status, Lee Stoner, Nicholas Castro, Anna Kucharska-Newton, Abbie E. Smith-Ryan, Sally Lark, Michelle A. Williams, James Faulkner, Paula Skidmore

Faculty Publications

This cross-sectional study determined whether 6-n-propylthiouracil (PROP) taster status moderates the relationship between food consumption patterns and body composition in children. Children were recruited (n = 342, 50% female, 8–10 y) from across New Zealand. Using a food frequency questionnaire, these food consumption patterns were derived: Processed Foods, Fruit and Vegetables, and Breakfast Foods. Body composition variables included: body fat (%), fat mass (kg), fat mass index (FMI, kg/m²), body mass index (kg/m²) and waist to height ratio (W:Ht). Following adjustment for confounders, Processed Foods were positively associated with %fat (p = 0.015), fat mass (p …

Evaluation Of The Stock Structure Of Cobia (Rachycentron Canadum) In The Southeastern United States By Using Dart-Tag And Genetics Data, Matt Perkinson, Tanya Darden, Maggie Jamison, Matt J. Walker, Michael R. Denson, James Franks, Read Hendon, Susanna Musick, Eric S. Orbensen

Faculty Publications

Available tag-recapture and population genetics data for cobia (Rachycentron canadum) in the southeastern United States were evaluated to provide information on population structure and determine the geographic boundary between stocks in the Gulf of Mexico and the Atlantic Ocean. The movements of 1750 cobia were evaluated on the basis of assigned tagging and recapture zones. Genetic samples from an additional 2796 cobia collected during the presumed spawning season were genotyped at 10 microsatellite loci, and standard population genetic statistical analyses were applied to the resulting sample data set. Tag-recapture results indicate that cobia tagged south of Cape Canaveral, …

Prospects For The Sustainable Management Of Public Oyster Resources, Thomas M. Soniat, Nathan A. Cooper, Eric N. Powell

Faculty Publications

Common-pool resources such as public oyster grounds are especially vulnerable to overexploitation and habitat loss. Like those elsewhere, oyster populations and habitat of Louisiana public grounds are in decline. To maintain reef habitat and increase oyster abundance, a sustainable harvest model is applied, which allows harvest above that required to maintain reef cultch stasis. The model is restrained to promote shell gain by limiting fishing by area, type (sack versus seed), effort, and season. Harvest quotas and cultch removal rates derived from shell-budget–based modeling are a foundation for sustainable management of public oyster resources.

The Evolutionary Diversity And Biological Function Of Phenazine Metabolite Biosynthesis In Burkholderia Spp, Samuel Hendry

Master's Theses

Burkholderia encompass a group of ubiquitous Gram-negative bacteria that include numerous saprophytes, as well as several species that cause infections in animals, immunocompromised patients, and plants. Some species of Burkholderia produce colored redox-active secondary metabolites called phenazines (Phz). In the model opportunistic pathogen Pseudomonas aeruginosa, phenazines strongly contribute to the competitiveness, formation of biofilms, and virulence in multiple models of infection. Similar depth of knowledge on the diversity, biosynthesis, and biological functions of phenazines in Burkholderiais missing. This project aimed to bridge this gap in knowledge by focusing on phenazine pathways of B. lata and closely related …

The Effects Of Aqueous Atorvastatin On Steroidogenesis Of Xenopus Laevis At Environmentally Relevant Concentrations, Jeremy Johnson

Master's Theses

Statin drugs are a class of drug that work to reduce endogenous production of cholesterol by competitively inhibiting 3-hydroxy-3-methyl-glutaryl-CoA reductase (Hmgcr) thus inhibiting production of mevalonic acid in the mevalonate pathway. Atorvastatin (Lipitor) is one of the most widely prescribed statin drugs and contamination of wastewater effluent is a growing environmental concern because of the potential to interfere with steroidogenesis in wildlife. Amphibians may be particularly susceptible to the effects of atorvastatin contamination because of their highly permeable integument. I used an amphibian model, Xenopus laevis to test the hypothesis that chronic exposure to low concentrations of atorvastatin …

The Ecology And Evolution Of The Freshwater Turtles Of Southern Mississippi, Gabrielle Berry

Master's Theses

Turtles are one of the most threatened group of animals in existence today. The Southeastern United States is one of two global biodiversity hotspots for turtle species, including the state of Mississippi, where over 30 species can be found. However, very few studies have occurred within the state. This lack of research is even more startling given the ongoing decline, or even extirpation, of numerous turtle species across the world, due to a number of factors, including habitat degradation, and harvest for food or the pet trade.

The overarching goal of this project was to perform a species inclusive freshwater …

Effects Of Light And Macroinvertebrate Consumers On Detrital Microbial Biofilms In Streams, Cheyenne M. Brady

Master's Theses

In lotic freshwater systems, aquatic macroinvertebrates are key processors of biofilms that grow upon organic matter. Although macroinvertebrate effects on biofilms may depend on light availability, the combined effects of consumers and light remain unexplored. Here, I conducted experiments to test effects of presence/absence of the omnivorous shrimp Macrobrachium ohione and the shredding caddisfly Pycnopsyche sp. on Liriodendron tulipifera litter biofilms in experimental streams under light or darkness. I measured litter-associated algal, fungal and bacterial biomasses and production rates, as well as litter decomposition, over 49 days. Both experiments exhibited significant positive effects of light on algal productivity and interactions …

Influence Of Varying Inorganic Nutrients Supply On Ergosterol And Glucosamine Concentrations And Biomass Nutrient Stoichiometry In Ectomycorrhizal Fungi, Stephanie S. Koury

Master's Theses

Ectomycorrhizal (ECM) fungi are critical for the health of forest ecosystems where they can sequester large amounts of carbon in the form of soil organic matter, a matter of growing interest due to anthropogenic climate change. A clear understanding of their growth dynamics and responses to environmental changes is imperative for future work in forest management and the possible mitigation of increased atmospheric CO₂. Six ECM fungal species were grown in liquid culture under varying nitrogen and phosphorus concentrations and ratios to assess how exogenous nutrient supplies affect fungal biomass stoichiometry and the degree of elemental homeostasis. Additional …

Acute Cardiovascular Response To Low-Load Unilateral, Bilateral, And Alternating Resistance Exercise With Blood Flow Restriction In The Lower Body, Daphney Stanford

Master's Theses

Resistance exercise with blood flow restriction (BFR) has been suggested to exaggerate the exercise pressor response over traditional non-BFR exercise. While applying BFR relative to an individual’s arterial occlusion pressure (AOP) and exercising at low-loads seems to produce a comparable cardiovascular response to traditional moderate or high-load training, it is beneficial to identify modifications for reducing the cardiovascular response to BFR exercise. PURPOSE: To determine if unilateral (UNI), bilateral (BI), or alternating (ALT) exercise modalities elicit different cardiovascular responses during BFR exercise. METHODS: 18 participants (13 male and 5 female) performed four sets of UNI, BI, and ALT knee-extensions at …

Molecular Responses To Deepwater Horizon Oil Spill Contaminants In Estuarine Fish, Elizabeth Jones

Dissertations

The 2010 Deepwater Horizon (DWH) oil spill resulted in the oiling of approximately 2100 km of shoreline. During that time, resident organisms had to contend with the effects of multiple contaminants and suboptimal environmental conditions. This research examines the molecular effects of DWH oil spill contaminants in estuarine fish (CyprinodonvariegatusandFundulusgrandis) across multiple life stages, contaminant concentrations, and in conjunction with environmental stressors.

Our results indicate that:

1. Oil elicits substantial transcriptional effects across life stages in C. variegatus. In adults, exposure to low concentrations of oil and dispersant results in transcriptional effects related …

Microrna Identification And Target Prediction In The Whitefly (Bemisia Tabaci), Alexis Aleman

Honors Theses

RNA interference, referred to as RNAi, is a biological phenomenon whereby knock-down of gene expression can be achieved through the use of RNA molecules, including small interfering RNAs (siRNAs) and microRNAs (miRNAs). The use of miRNAs is an endogenous pathway that results in the degradation of the miRNA strand’s complementary messenger RNA (mRNA), preventing the translation of the mRNA and therefore the production of the proteins necessary for gene expression. While RNAi is a biological phenomenon that occurs naturally, it is also a method that can be used and manipulated in the laboratory to try to control the expression of …

Differences In Falls And Recovery From A Slip Based On An Individual's Lower Extremity Corrective Response, Samuel J. Wilson, Paul T. Donahue, Charles C. Williams, Christopher M. Hill, Jeffrey D. Simpson, Dwight E. Waddell, Jeremy P. Loenneke, Harish Chander, Chip Wade, John C. Garner

Faculty Publications

Background: Slips and falls account for high rates of injury and mortality in multiple populations. The corrective responses during the slip perturbation have been well documented. However, when a fall results from a slip, it is unclear which of these responses were inadequate.

Objective: The purpose of this study was to examine differences in lower extremity corrective responses of the slip recovery response between individuals who fall and those who recover.

Methodology: Sixty-four participants completed this study (32 males & 32 females). Participant’s gait kinematics and kinetics were collected during normal gait (NG) and an unexpected slip …

Comparison Of Age And Growth Parameters Of Invasive Red Lionfish (Pterois Volitans) Across The Northern Gulf Of Mexico, Alexander Q. Fogg, Joseph T. Evans, Mark S. Peterson, Nancy Brown-Peterson, Eric R. Hoffmayer, G. Walter Ingram Jr.

Faculty Publications

Invasive red lionfish (Pterois volitans) have spread rapidly throughout the northern Gulf of Mexico (GOM) partly because of their high growth rate. Red lionfish were collected from the northern GOM across 3 ecological regions from 2012 through 2015. For male and female red lionfish, relationships between weight and total length (TL) were differnt by ecological region. Males acheives a greater mean weight adjusted for TL (333.6 g [standar errer (SE) 3.6]) than females (195.1 g [SE 3.7]). A subsample of 1607 pairs of sagittal otoliths (from 744 males, 716 females, and 147 fish of unknown or undetermined sex) …

Preliminary Investigation Of A Diverse Megafossil Floral Assemblage From The Middle Miocene Of Southern Mississippi, Usa, Daniel M. Mcnair, Debra Z. Stults, Brian Axsmith, Mac H. Alford, James E. Starnes

Faculty Publications

Our understanding of Miocene floras in eastern North America is hampered by the rarity of megafossil sites. An early report from the middle Miocene Hattiesburg Formation in Mississippi included palms and Ulmus. A later report listed Taxodium, Salix, either Morus or Celtis, and monocot fragments. The floral assemblage described here was recently recovered from along the Bouie River in southern Mississippi. Ferns are represented by complete Salvinia specimens including attached sporocarps, Woodwardia, and Osmunda. Conifers are represented by branchlets of Taxodium. Angiosperms include leaves attributable to the Lauraceae. Platanus is known from leaves, stipules, and fruits. …

Scale Dependence Of Sex-Specific Movement In A Small-Bodied Stream Fish, Scott R. Clark, Brian R. Kreiser, Jacob F. Schraefer, Laura K. Stewart

Faculty Publications

1. Animal movement at localised scales is often modulated by competing pressures such as avoiding predators while acquiring resources and mates. The relative magnitude of these trade‐offs may affect males and females differently, often resulting in sex‐specific differences in movement.
2. Sex‐biases in movement have been linked to mating systems (e.g. monogamy or polygamy) in birds and mammals; however, this relationship has received less attention among fishes. Using passive integrated transponder tags and a series of stationary antennas, we evaluated the movement dynamics of a small‐bodied, sexually dimorphic stream fish Fundulus olivaceus over a 30‐day period in a fourth‐order tributary to the …

The Molecular Biogeography Of The Indo-Pacific: Testing Hypotheses With Multispecies Genetic Patterns, Eric D. Crandall, Cynthia Riginos, Chris E. Bird, Libby Liggins, Eric Treml, Maria Beger, Paul H. Barber, Sean R. Connolly, Peter F. Cowman, Joseph D. Dibattista, Jeff A. Eble, Sharon F. Magnuson, John B. Horne, Marc Kochzius, Harilaos A. Lessios, Shang Yin Vanson Liu, William B. Ludt, Hawis Madduppa, John M. Pandolfi, Robert J. Toonen, Michelle R. Gaither

Faculty Publications

Aim: To test hypothesized biogeographic partitions of the tropical Indo-Pacific Ocean with phylogeographic data from 56 taxa, and to evaluate the strength and nature of barriers emerging from this test.

>Location: The Indo-Pacific Ocean.

Time Period: Pliocene through the Holocene.

Major Taxa Studied: Fifty-six marine species.

Methods: We tested eight biogeographic hypotheses for partitioning of the Indo-Pacific using a novel modification to analysis of molecular variance. Putative barriers to gene flow emerging from this analysis were evaluated for pairwise Φ_ST, and these Φ_ST distributions were compared to distributions from randomized datasets and …

Linking Nutrient Stoichiometry To Zika Virus Transmission In A Mosquito, Andrew S. Paige, Shawna K. Bellamy, Barry W. Alto, Catherine L. Dean, Donald A. Yee

Faculty Publications

Food quality and quantity serve as the basis for cycling of key chemical elements in trophic interactions; yet the role of nutrient stoichiometry in shaping host–pathogen interactions is under appreciated. Most of the emergent mosquito-borne viruses affecting human health are transmitted by mosquitoes that inhabit container systems during their immature stages, where allochthonous input of detritus serves as the basal nutrients. Quantity and type of detritus (animal and plant) were manipulated in microcosms containing newly hatched Aedes aegypti mosquito larvae. Adult mosquitoes derived from these microcosms were allowed to ingest Zika virus-infected blood and then tested for disseminated infection, transmission, …

Discovery And Characterization Of Bacteriophage Luckybarnes, Savannah L. Underwood, Amanda Foto, Amanda F. Ray, Alexander E. Nelms, Keyshawn L. Kennedy, Shelby G. Hartley, Logan M. Ryals, Chandan Gurung, William A. D'Angelo, Welkin H. Pope, Dmitri V. Mavrodi

Faculty Publications

Here, we report the genome sequence of LuckyBarnes, a newly isolated singleton siphovirus that infects Brevibacterium iodinum ATCC 15728 and has a 50,774-bp genome with 67 predicted genes.

Repurposing Of Glycine-Rich Proteins In Abiotic And Biotic Stresses In The Lone-Star Tick (Amblyomma Americanum), Rebekah Bullard, Surendra Raj Sharma, Pradipta Kumar Das, Sarah E. Morgan, Shahid Karim

Faculty Publications

Tick feeding requires the secretion of a huge number of pharmacologically dynamic proteins and other molecules which are vital for the formation of the cement cone, the establishment of the blood pool and to counter against the host immune response. Glycine-rich proteins (GRP) are found in many organisms and can function in a variety of cellular processes and structures. The functional characterization of the GRPs in the tick salivary glands has not been elucidated. GRPs have been found to play a role in the formation of the cement cone; however, new evidence suggests repurposing of GRPs in the tick physiology. …

Changes In The Spatial Distribution And Anatomy Of A Range Shift For The Atlantic Surfclam Spisula Solidissima In The Mid-Atlantic Bight And On Georges Bank, Jeremy R. Timbs, Eric N. Powell, Roger Mann

Faculty Publications

The Atlantic surfclam Spisula solidissima supports one of the largest fisheries on the US northeast coast. Using ~30 yr of data from surfclam stock surveys, variance-to-mean ratios (VtMRs) were calculated both temporally and spatially for a range of surfclam size classes to determine the degree of patchiness. The VtMR declined from the 1980s to present in all regions (offshore Delmarva, New Jersey, Long Island, Southern New England, Georges Bank); however, VtMR rose with increasing clam size. Taylor’s power law (TPL) analysis corroborated the VtMR; the surfclam is highly patchy across its range. The surfclam’s proclivity for a patchy distribution varied …

Linking Water Quality To Aedes Aegypti And Zika In Flood-Prone Neighborhoods, Susan Harrell Yee, Donald A. Yee, Rebeca De Jesus Crespo, Autumn Oczkowski, Fengwei Bai, Stephanie Friedman

Faculty Publications

The ability of ecosystems to regulate water quality and flood events has been linked to health outcomes, including mosquito-borne illnesses. In the San Juan Bay Estuary watershed of Puerto Rico, habitat alterations and land-use development have disrupted watershed hydrology, exacerbating wastewater discharges and subjecting some neighborhoods to frequent flooding events. In 2016, the mosquito-borne illness Zika became a new cause for concern. We hypothesized that nutrient-enriched flood water could provide pulses of supplemental nutrients to local mosquito populations. We conducted a field study in six neighborhoods adjacent to the estuary to assess whether environmental variability of nutrient inputs could be …

Is Selenoprotein K Required For Borrelia Burgdorferi Infection Within The Tick Vector Ixodes Scapularis?, Deepak Kumar, Monica Embers, Thomas N. Mather, Shahid Karim

Faculty Publications

Background: Tick selenoproteins are involved in regulating oxidative and endoplasmic reticulum stress during prolonged tick feeding on mammalian hosts. How selenoproteins are activated upon tick-borne pathogen infection is yet to be defined.

Methods: To examine the functional role of selenoprotein K in Borrelia burgdorferi infection within the tick host Ixodes scapularis, RNA interference (RNAi)-based gene silencing was performed.

Results: Selenoprotein K is an endoplasmic reticulum (ER)-resident protein and a component of the ERAD complex involved in ER homeostasis. A qRT-PCR assay revealed the significant upregulation of selenogene K (selenoK) expression in B. burgdorferi-infected …

Expenditure, Coping, And Academic Behaviors Among Food-Insecure College Students At 10 Higher Education Institutes In The Appalachian And Southeastern Regions, Rebecca L. Hagedorn, Laura H. Mcarthur, Lanae B. Hood, Maureen Berner, Elizabeth T. Anderson Steeves, Carol L. Connell, Elizabeth Wall-Bassett, Marsha Spence, Oyinlola Toyin Babatunde, E. Brooke Kelly, Julia F. Waity, J. Porter Lillis, Melissa D. Olfert

Faculty Publications

Background

A number of studies have measured college student food insecurity prevalence higher than the national average; however, no multicampus regional study among students at 4-y institutions has been undertaken in the Appalachian and Southeast regions of the United States. Objectives

The aims of this study were to determine the prevalence of food insecurity among college students in the Appalachian and Southeastern regions of the United States, and to determine the association between food-insecurity status and money expenditures, coping strategies, and academic performance among a regional sample of college students. Methods

This regional, cross-sectional, online survey study included 13,642 college …

In Silico Identification Of Genetic Mutations Conferring Resistance To Acetohydroxyacid Synthase Inhibitors: A Case Study Of Kochia Scoparia, Yan Li, Michael D. Netherland, Chaoyang Zhang, Huixiao Hong, Ping Gong

Faculty Publications

Mutations that confer herbicide resistance are a primary concern for herbicide-based chemical control of invasive plants and are often under-characterized structurally and functionally. As the outcome of selection pressure, resistance mutations usually result from repeated long-term applications of herbicides with the same mode of action and are discovered through extensive field trials. Here we used acetohydroxyacid synthase (AHAS) of Kochia scoparia (KsAHAS) as an example to demonstrate that, given the sequence of a target protein, the impact of genetic mutations on ligand binding could be evaluated and resistance mutations could be identified using a biophysics-based computational approach. Briefly, …

Comparison Of Anthracnose Resistance With The Presence Of Two Scar Markers Associated With The Rca2 Gene In Strawberry, Melinda A. Miller-Butler, Barbara J. Smith, Brian R. Kreiser, Eugene K. Blythe

Faculty Publications

Strawberry anthracnose diseases are caused primarily by three Colletotrichum species: C. acutatum J.H. Simmonds, C. fragariae A.N. Brooks, and C. gloeosporioides (Penz.) Penz. & Sacc. Molecular markers are being used in breeding programs to identify alleles linked to disease resistance and other positive agronomic traits. In our study, strawberry cultivars and breeding germplasm with known anthracnose susceptibility or resistance to the three anthracnose-causing Colletotrichum species were screened for two sequence characterized amplified region (SCAR) markers linked to the Rca2 gene. The Rca2 resistant allele SCAR markers were associated with varying degrees of significance for a strawberry plant’s anthracnose resistance to …