Life Sciences Commons^™

Occurrence, Antibiotic Resistance, And Survival Of Fecal Enterococci In Turkey Litter, Steven Glynn Mcbride Ii

Masters Theses, 2010-2019

The United States Environmental Protection Agency’s National Water Quality Inventory and the Commonwealth of Virginia’s 305(b)/303(d) Water Quality Assessment Integrated Report show fecal bacteria to be the most common cause of impairment for both streams and estuaries. Human and animal sources have both been identified as significant contributors of pathogenic bacteria to surface waters. In this study, turkey litter from a farm in Shenandoah County, VA was surveyed for total culturable bacteria and total culturable enterococci before and after a transition to organic rearing practices. The enterococci were identified to species phenotypically using the Biolog Microbial Identification System and resistance …

Variation In Female Mating Behavior And Success In The Damselfly, Calopteryx Maculata, Suzanne E. Allison

Masters Theses, 2010-2019

Traditionally, the study of sexual selection has focused on the evolution of elaborate male traits and how they enhance the ability to out-compete other males directly (access to females) and indirectly (access to desirable territories or resources). Female trait studies have focused most on evolved preferences for male traits. While we know much about how sexual selection acts on males, there is a deficit of equivalent study on females. In insects, including damselflies, male size and pigmentation are positively correlated with fat reserves and immune abilities, and therefore with male competitive ability. Here, we show that phenotypic variation that has …

Vertical Movement Of The Endangered James Spinymussel (Pleurobema Collina) And The Notched Rainbow Mussel (Villosa Constricta) In Response To Floods At Different Temperatures And Substrates: Implications For Conservation And Management, Dorottya Boisen

Masters Theses, 2010-2019

Freshwater mussels are keystone species in their ecosystems, improving water and substrate quality for other organisms while they are alive, and buffering stream pH and providing shelter with their shells after they die. Approximately 70% of all freshwater mussel species are endangered globally. The James Spinymussel (Pleurobema collina) is a critically endangered species that lives in disparate tributaries of the James River of Virginia. Like other freshwater mussels, they have a cryptic appearance and behavior, making them difficult to find and therefore, to study and conserve. Previous studies indicate a higher percentage of mussels are surfaced during their …

A 16-Week Run Sprint Interval Training Does Not Have An Effect On Cardiovascular Risk Measured By Framingham Risk Score On Prediabetic Women, Joan A. Mandelson

Masters Theses, 2010-2019

The Framingham risk score (FRS) was developed to determine the likelihood of developing cardiovascular disease (CVD) in the next 10 years using an individual’s age, gender, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), smoking habits, and systolic blood pressure (SBP). Run-sprint interval training (R-SIT) has shown improvements in various health and blood markers while reducing total exercise time. To date there has not been a study that examines the effects of R-SIT and moderate intensity training (MIT) on framingham risk. The purpose of this study was to determine if a reduction of the 10-year risk of CVD (determined by …

A Low-Carbohydrate Ketogenic Diet Combined With Six Weeks Of Crossfit Training Improves Body Composition And Performance, Rachel M. Gregory

Masters Theses, 2010-2019

A low-carbohydrate ketogenic diet (LCKD) is a popular approach to weight and fat loss. CrossFit is a high-intensity power training (HIPT) type exercise for all levels of age and fitness that has gained recognition as one of the fasting growing sports in America. No previous research has been found which examines body composition changes or performance in individuals consuming a LCKD and participating in CrossFit training. PURPOSE: The purpose of this research was to examine the effects of a 6-week LCKD and CrossFit program on body composition and performance. METHODS: Twenty-seven non-elite CrossFit subjects (mean ± SD age = …

The Effect Of Water Quality On The Survival And Fitness Of Brook Trout (Salvelinus Fontinalis) Eggs, Alevins And Fry In Aquaculture And Deep Springs Along The South River In Waynesboro, Va, Thomas D. Teears

Masters Theses, 2010-2019

Brook trout populations have been extirpated in many Virginia streams due to poor water quality thus establishing populations of brook trout for recreational fishing is an important priority of fisheries management. The ability of a stream to protect developing brook trout (Salvelinus fontinalis) eggs and larval fish from adverse effects from acidification and metal toxicity as well as provide needed minerals such as magnesium (Mg²⁺) and calcium (Ca²⁺) for early-stage development is controlled primarily by geology, which influences water hardness and acid-neutralizing capacity (ANC). The focus of this research was on the effects of …

A Single Night Of Sleep Restriction Impairs Recovery From Heavy Exercise, John D. Chase

Masters Theses, 2010-2019

We examined the effects of one night of sleep restriction (Sleep-; 2.5 hrs) on subsequent 3-km cycling performance and skeletal muscle recovery from heavy exercise compared to a full night of rest (Sleep+; 7 hrs). Seven recreational cyclists (n=6 male, n=1 female; age = 24.4 ± 7 yrs; height = 170 ± 10 cm; weight = 68 ± 13 kg VO_2max = 61.5 ± 4.4 ml/kg/min) completed four simulated 3-km time trials (TT) and six peak isokinetic torque trials at different speeds (30 and 120°/sec) under both conditions. The first exercise trial (EX1) consisted …

The Effect Of Sleep Restriction On Coagulation And Fibrinolysis After Heavy Exercise, Paul A. Roberson

Masters Theses, 2010-2019

Introduction: Research has shown exercise elicits a hemostatic response affecting coagulation and fibrinolysis. Furthermore, prior research has determined circadian fluctuations exist where clotting potential increases in the morning as a result of increased PAI-1 and decreased tPA which is further exacerbated by exercise. These circadian fluctuations and exercise responses have the potential to be accentuated by poor sleep. The purpose of this study is to determine the effects of sleep restriction on tPA activity, PAI-1 activity, and Factor VIII antigen activity (FVIII) while resting and after exercise.

Methods: 7 Subjects underwent two similar exercises sessions (EX). EX1 occurred in the …

The Effect Of Stimulus Location And Initial Posture On The Kinematics Of The Nociceptive Withdrawal Reflex Of The Tail In Intact And Unanaesthetized Rats, Yulhea Kim

Masters Theses, 2010-2019

The nociceptive withdrawal reflex (NWR) is a protective reflex that allows mammals to avoid noxious stimuli by withdrawing the affected area of the body away from the stimulus. Although previous studies on non-human mammals showed that the NWR depends on stimulus location and initial posture, these studies were performed on spinalized or anaesthetized animals, which may yield results differing from intact animals. Therefore, the purpose of this study was to determine whether the kinematics of the NWR of the tail depends on stimulus location and initial posture in intact and unanesthetized animals. The NWR was evoked by heat applied to …

Next-Generation Sequencing Of A Multi-Drug Resistance Plasmid Captured From Stream Sediment, Kevin G. Libuit

Masters Theses, 2010-2019

Plasmids in agriculturally-impacted bodies of water may play a significant role in the dissemination of antibiotic resistance. Previously, Erika Gehr, as part of her M.S. thesis work in our laboratory, captured environmental plasmids without cultivation of host bacteria from stream sediment into Escherichia coli. Individual plasmids were capable of conferring resistance to a surprising array of antibiotics including aminoglycosides and extended-spectrum β-lactams. In this study, we developed a method to sequence multi-drug resistance plasmids using both Oxford Nanopore MinION and Ion Torrent Personal Genome Machine sequencers. Plasmid pEG1-1 was sequenced on both platforms and a hybrid assembly utilizing data …

The Influence Of Time-Of-Day Consumption And Training Status On The Ergogenic Properties Of Caffeine, James C. Boyett

Masters Theses, 2010-2019

Purpose: The objectives were to determine the effects of time-of-day consumption and training status on the benefits of caffeine supplementation for cycling performance and peak muscle strength. METHODS: Twenty untrained and trained subjects completed four trials consisting of isokinetic peak torque testing and 3-km time trials (TT). Subjects ingested either 6 mg/kg of caffeine or a placebo one hour prior to each trial. Treatments were: morning + placebo, morning + caffeine, evening + placebo, evening + caffeine. Magnitude based inferences were used to evaluate treatment differences. RESULTS: Caffeine (‘very likely’ and ‘likely’) improved 3-km TT performance in the morning and …

The Effects Of Chronic Partial Sleep Deprivation And Chronic Voluntary Alcohol Consumption On Δfos B Accumulation, Kristian Ponder

Masters Theses, 2010-2019

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors. Accumulation of the transcription factors ΔFosB is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between ΔFosB and chronic alcohol consumption. There were four experimental groups in this study: Control (C), Sleep Deprivation only (SD), Alcohol Exposure only (AO), and both sleep deprivation and alcohol exposure (B). Levels of ΔFosB accumulation in the Nucleus Accumbens (NAc) revealed a significant main effect of sleep deprivation, but no …

Using Morphometrics To Evaluate Taxonomic Relationships In Eleocharis Tenuis (Cyperaceae), Lane D. Gibbons

Masters Theses, 2010-2019

North America is host to multiple complex taxa, and unresolved relationships in the genus Eleocharis (Cyperaceae). Of noteworthy significance, are lasting taxonomic uncertainties involving plants referable to E. tenuis (var. tenuis, var. verrucosa, and var. pseudoptera) of the E. tenuis species complex. Morphology of E. tenuis is traditionally recognized as being widely variable, and intermediate among taxa along a broad geographic gradient. Cytological and morphometric data however, indicate that the varieties of E. tenuis are unique in cytology, and are consistently delimited by five morphological characters. Furthermore, this study shows that cytological data correlates with unique morphological …

Prioritizing Eastern Hemlock (Tsuga Canadensis) For Secondary Imidacloprid Treatment Against The Invasive Hemlock Woolly Adelgid (Adelges Tsugae) In Shenandoah National Park, Katelyn Walters

Masters Theses, 2010-2019

Shenandoah National Park (SNP) contains over 20,000 eastern hemlocks (Tsuga canadensis); a foundation species in the southern Appalachian Mountains. Hemlock is shade-tolerant and retains a dense needle canopy year-round, creating a unique microclimate providing habitat for many species. The decline in eastern hemlock from hemlock woolly adelgid (Adelges tsugae; HWA) infestation has negative implications for the overall function of forest ecosystems. The effect of slope aspect and time since imidacloprid insecticide treatment on crown health change and diameter growth of eastern hemlock in SNP was quantified. Data was compared from hemlock trees located on southeastern (SE) and …