Life Sciences Commons^™

Cholesterol Mass Fingerprinting To Probe Cholesterol-Protein Interactions, Warren Lowther

Electronic Theses and Dissertations

Cryomicroscopy, crystallography and NMR have been considered the “gold standard” of structural biophysics for some time. Recent successes in using these techniques has provided us with a plethora of insight into the architecture of different macromolecules like channels, transporters, and other molecular machines. However, information is often limited to a single allosteric state with the macromolecule in a non-native environment. Additionally, these traditional methods tend to be expensive and labor-intensive, requiring samples that are concentrated and highly purified. Chemical crosslinking coupled with mass spectrometry (CX-MS) has emerged as the ideal accessory for the aforementioned structural tools. In order to address …

Impact Of Unconventional Gas Extraction On Tributaries Of Tenmile Creek, Greene County, Pennsylvania: A 12-Year Perspective, Christian L. Beall

Electronic Theses and Dissertations

Much of southwestern Pennsylvania has been central to a rapid increase in development for unconventional natural gas extraction in the past two decades. The continued monitoring of streams over their lifetime as extraction sites is pivotal to understanding the effects of fracking on local waterways and their ability to provide for wildlife and human use. Here, using multiple indices of biotic integrity (IBI), I perform analyses of fish and macroinvertebrate communities as well as water chemistry on two streams, Bates Fork (with shale wells) and Fonner Run (without), as part of a follow-up to work performed there from 2010-2012. Fish …

Demography Of Alligator Snapping Turtles (Macrochelys Temminckii) Along A Fishing Pressure Gradient, Luke T. Micek

Electronic Theses and Dissertations

Passive fishing gear is a threat to the alligator snapping turtle (Macrochelys temminckii). The spatio-temporal persistence of this threat and its impacts on M. temminckii populations has not been quantified. I quantified the density of passive fishing gear and the demographic parameters of M. temminckii along a fishing pressure gradient in East Texas streams. Most gear was abandoned and illegally deployed, with densities varying seasonally. Detectability of passive fishing gear declined with increasing gear age, water depth, and volume, but increased with increasing precipitation. Macrochelys temminckii catch per unit effort, abundance, and survival was lower at sites with …

Swine Solutions: Enhancing Ffa Supervised Agricultural Experience Projects, Hannah M. Daily, Dr. John Michael Mehaffey, Dr. Candis Scallan, Dr. Amy Mehaffey, Dr. Joe Mask

Electronic Theses and Dissertations

Supervised Agricultural Experience (SAE) is a portion of the three-circle model of agriculture education, providing experiential learning opportunities for students. The immersion SAE encourages students to build upon foundational learning components in a real-world application. A popular area of the immersion SAE includes ownership of market swine being raised for exhibition. This study serves as a pilot mentorship program for agricultural science educators and students, creating an educational resource encouraging record-keeping techniques and skill development, leading to eventual independence from the student’s standpoint. The model for the Swine Solutions Program includes utilization of the provided handbook, completion of daily observation …

Evaluating Predictive Models For Predicting Total Score Of Beef Carcasses, Emmanuel Forson

Electronic Theses and Dissertations

The beef industry plays a vital role in global agriculture, with carcass quality and consumer preference being key determinants of market success. This thesis examines predictive modeling techniques for estimating the Total Score of beef carcasses, a composite measure representing yield and quality, primarily used by the Nebraska Cattlemen Association. Using data from the Nebraska Cattlemen’s Foundation Retail Value Steer Challenge (2000–2023), the study compares the performance of First Order Multiple Linear Regression (MLR) with three machine learning techniques: K-Nearest Neighbors (KNN), Random Forest, and Gradient Boosting Machine (GBM).

The analysis focuses on six key predictors: Hot Carcass Weight, Back …

Patterns Of Taxonomic, Functional, And Phylogenetic Diversity, And Ecological Drivers Of Stream Fish Assemblages In East Texas, Anastasia M. Umstott

Electronic Theses and Dissertations

Freshwater ecosystems in East Texas contain a rich freshwater biodiversity, with the Neches and Sabine River basins supporting some of the greatest freshwater fish diversity in the state. Given the heterogeneity of habitats and species diversity, these rivers serve as excellent natural systems for examining the ecological processes shaping biodiversity patterns and species distributions. In 2023-2024, 60 streams in the Neches and Sabine River basins were surveyed across three seasons to investigate the patterns and ecological drivers of taxonomic (TDβ), functional (FDβ), and phylogenetic β-diversity (PDβ) facets of freshwater fish assemblages. Additionally, I created two ecological niche models for a …

Mechanisms Of Particulate Hexavalent Chromium-Induced Inhibition Of Homologous Recombination Repair: Targeting The Bcdx2 Complex Considered Through A One Health Perspective., Aggie W. Brownell

Electronic Theses and Dissertations

Lung cancer remains the leading cause of cancer death, often linked to smoking. However, smoking alone does not account for all cases. Exposure to environmental metals like hexavalent chromium [Cr(VI)] also contributes to lung cancer. Cr(VI) causes lung cancer by inducing chromosome instability (CIN), an early hallmark of its carcinogenic mechanism. While it has been established that Cr(VI) induces chromosome instability, the precise mechanisms underlying the chromosome instability are poorly understood. This dissertation investigates the mechanisms of carcinogenesis associated with zinc chromate, a particularly potent particulate form of hexavalent chromium. Studies show Cr(VI) induces DNA double-strand breaks and impairs the …

Genetic Influence Of Allelic Variation On The Phenotypic Variability Of Cognitive Outcomes In Individuals With Williams Syndrome., Marinie P. Joseph

Electronic Theses and Dissertations

Williams syndrome (WS) is caused by a rare microdeletion of 25 – 27 genes on chromosome 7q11.23, characterized by a distinctive cognitive profile with considerable phenotypic heterogeneity. However, the genetic factors underlying this phenotypic variability remain unclear. I explored two genetic mechanisms—parent-of-origin (PoO) effects and genome-wide polygenic variation, as measured by polygenic scores (PGSs)—to elucidate possible influences on cognitive variability in WS. The first study examined PoO effects on cognitive abilities in two overlapping samples of children with WS (N = 211, N = 251). PoO refers to which parental homolog of chromosome 7 contains the WS deletion. Despite …

Volatile Organic Compounds And Their Relation To Sympathetic Activation And Autonomic Balance In Humans., Cameron Kyle Stopforth

Electronic Theses and Dissertations

Cardiovascular disease (CVD) is a multifaceted pathology that affects almost half of Americans ≥20 years old. One modifiable risk factor associated with CVD is air pollution exposure. The intricacy of air pollution exposure and CVD can make it difficult to elucidate on the multitude of mechanisms underpinning these associations. In this dissertation, we selected a relevant exposure (i.e., volatile organic compounds (VOC)) and an intermediate outcome (i.e., autonomic balance) that may represent one of these pertinent mechanisms. We tested the central hypothesis that higher VOC exposures would lead to increased sympathetic activation and autonomic imbalance. Aim 1 (Chapter III …

Investigation Into Mycorrhizae Associated With Native Venus' Flytrap Root Tissue, Anna Carnaggio

Electronic Theses and Dissertations

Dionaea muscipula, a plant commonly known as the Venus' flytrap, is found native to the southeast corner of North Carolina and the northeast corner of South Carolina. Several populations of native Venus' flytraps are known to exist in the nutrient-poor peat bog conditions in and around Lewis Ocean Bay Heritage Preserve (LOBHP) in Northeastern South Carolina. Anthropogenic pressures in Horry County, specifically surrounding LOBHP, have resulted in a loss of habitat for several native and endangered species. As a result, conservation efforts are focused on relocating native Venus' flytraps into adjacent habitats to ensure survival. This is only a temporary …

Life History Inhibits Deleterious Effects Of Dams On Genetic Health And Structure Of A Headwater Stream Fish, Riley Phelps

Electronic Theses and Dissertations

Habitat loss, fragmentation, and land use changes in river networks are common globally. The resulting fragmentation of landscapes and riverscapes threatens biodiversity and can affect dispersal and subsequently, gene flow and genetic health of species. Headwater streams are an integral part of river networks and contribute to biodiversity by providing habitat for temporary and permanent residents, yet they are easily altered and fragmented. The sandhills chub (Semotilus lumbee) is an endemic headwater leuciscid that lives in highly fragmented streams of the sandhills ecoregion in North and South Carolina, USA. New knowledge on the population genetics of the sandhills chub is …

Investigating Stress Hormone Variations In Green Frogs (Lithobates Clamitans) During The Mating Season, Abby Mciver

Electronic Theses and Dissertations

Monitoring stress hormones in wildlife populations is increasingly used to understand how human activities may impact the environment. The goal of this study was to quantify corticosterone in green frogs (Lithobates clamitans) at baseline levels and in response to an acute stressor throughout the mating season. The project was conducted from May to September of 2024 at Bays Mountain Park in Kingsport, Tennessee. Corticosterone levels were determined over six consecutive days each month from May to September using a non-invasive dermal swab technique. Additionally, body metrics, water chemistry, and weather and habitat conditions were evaluated on each sampling …

Movement Ecology Of Sandhills Chub, A Carolina Endemic, Zachary Adam Ramsey

Electronic Theses and Dissertations

Fish movement studies have traditionally focused on species that support commercial and recreational fisheries, but recently more focus has been given to non-game, stream fishes because of their recognized importance in maintaining biodiversity within these ecosystems. Stream fish movement is described as being “restricted” and following a leptokurtic distribution via diffusive spread related to environmental and biological factors. Many studies of stream fish movement ecology in North America have occurred in high-gradient streams with coarse substrate in mountains or in streams of the interior plains. Sandhills streams of the southeastern USA are characterized as warm-water, low gradient, and dominated by …

Flow Field Surrounding Bluegill (Lepomis Macrochirus) During Suction-Feeding, Jensine Caroline Coggin

Electronic Theses and Dissertations

Suction-feeding is a common method for capturing prey by aquatic organisms and contributed to the diversification of fishes by enabling them to consume a wide range of prey. Suction-feeding is a complex fish-fluid interaction governed by various hydrodynamic forces: inertia, unsteady, viscous, and pressure gradients. These forces are described by the coupling between the flow physics equations (Navier-Stokes) and the dynamic behavior of the fish (motion and forces). However, the distribution of the pressure field that drives this process, and the extent to which suction-feeding is three-dimensional, remain underexplored. I estimated the pressure within the flow field surrounding the mouth …

Heterotopias Of Confinement: Zoo Architecture And The Loss Of Elephant Agency, Clayton Gill Beasley

Electronic Theses and Dissertations

Zoos functions as a site where human-animal relationships are structured through built environments that mediate control and representation. This study examines zoos as heterotopias—spaces where power and surveillance are negotiated between human observers and captive nonhuman animals. While zoos are often framed as spaces of conservation and education, their architectural design reinforces hierarchies of observation and confinement, shaping both human perceptions of nature and the lived experiences of nonhuman animals. This research focuses on Asian elephants as a critical species within this framework, exploring how their captivity illuminates tensions between human-imposed structures and nonhuman autonomy. Drawing from theories of heterotopia, …

Translation Of The Carcinogenic Dna Breakage-Repair Inhibition Mechanism For Hexavalent Chromium To Its Key Targets: Lung Epithelial Cells, Lung Tissue And Impacts On The Genome., Idoia Meaza Isusi

Electronic Theses and Dissertations

Lung cancer is the leading cause of cancer death worldwide. Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread occupational and environmental exposure. Despite the known health risks, how Cr(VI) causes lung cancer remains unclear. This dissertation investigates the mechanisms of Cr(VI)-induced carcinogenesis. Cr(VI) causes DNA damage, specifically DNA double strand breaks, and inhibits homologous recombination repair, a high-fidelity repair pathway. Unrepaired DNA double strand breaks or those repaired through error-prone pathways, progress to chromosomal damage, and chromosome instability. The latter is a common characteristic of Cr(VI)-exposed cells, and a hallmark of lung cancer. Although the mechanism of Cr(VI)-induced …

Dirty Dianthus: A Review Of The Microbotryum-Dianthus Plant Pathogen System., Roxanne Kaaren Hayes

Electronic Theses and Dissertations

Microbotryum dianthorum is a species complex of smut fungi that act as biotrophic plant pathogens of Dianthus flowering plants. This group of pathogenic fungi are situated within a larger group of fungi that act as biotrophic plant pathogens, some of which are responsible for extensive crop loss in our agricultural system. These pathogens are distinct from other Microbotryum species in their ability to infect not only a single host, but multiple hosts. Their unique ability to parasitize several plant hosts may unlock potential clues about the potential for emergent infection disease in crop systems. Previous work has established that these …

Knowledge And Perceptions About Feeding And Growth In Infants And Young Children Among Early Interventionists, Kayla Chambers

Electronic Theses and Dissertations

Nutrition plays a vital role in early childhood, where rapid growth and development occur. This study investigates Early Interventionists’ (EIs) nutrition knowledge and perceptions of nutrition-related concerns in children receiving services through the Tennessee Early Intervention System (TEIS). An electronic survey was distributed to EIs in Tennessee to assess their nutrition knowledge and perceptions and to identify nutrition concerns. Findings revealed that most EIs have never received any nutrition education, despite being asked for nutrition guidance by families and being open to nutrition-related training. The EIs reported seeing nutrition concerns such as growth delays, food refusal, and picky eating, but …

The Reliability And Validity Of Accelerometry And Gnss, Christine Coniglio

Electronic Theses and Dissertations

This dissertation seeks to evaluate the reliability, validity, and utility of accelerometers and GNSS in sport-like scenarios, assess accelerometry-derived metrics and GNSS for distance prediction, and explore how accelerometer placement, specifically chest and back, affect the detection of various locomotor events. In Study I, the purpose was to investigate the accelerometer reliability and predictive capabilities of accelerometers and GNSS to predict a known distance. Thirty physically active female participants (mean height = 163.6 ± 6.8 cm, mean weight = 57.8 ± 8.7 kg) completed jogging trials over two courses (5m and 20m). Each participant wore two tri-axial accelerometers (100Hz) and …

The Forest Through The Trees: Modeling The Ecological Niche And Potential Assemblage Distribution Of Oak-Hickory Forests Across The Eastern U.S., Elijah Worley

Electronic Theses and Dissertations

Understanding how tree species’ ranges and populations may shift by the end of the 21^st Century is critical for effective conservation and forest management. Ecological niche models are widely used to predict species distributions by modeling the relationships between environmental variables and species presence. While numerous models have been developed for individual tree species across the USA, there is limited research on how tree species assemblages, such as oak-hickory forests, will respond to changes in climate over time. Maxent modeling software was used to predict potential shifts in suitable habitat for the oak-hickory forest type, based on environmental variables …

Unraveling The Unknown: Characterization Of A Novel Antimicrobial Compound Found In Klebsiella Pneumoniae, Jasmal Cruz Perez

Electronic Theses and Dissertations

Klebsiella pneumoniae, a pathogenic bacterium resistant to numerous antimicrobials, is a worldwide health issue due to its ability to cause healthcare-associated diseases such as pneumonia and urinary tract infections. This study investigated an antimicrobial compound secreted by K. pneumoniae. The compound was found to possess inhibitory activity against Enterobacteriaceae members, including other Klebsiella pneumoniae strains, Citrobacter freundii, and Enterobacter cloacae. The inhibitory activity is mediated via a secreted protein that is active across a wide range of pH and temperature conditions. Higher concentrations of the compound enhanced antimicrobial activity. The antimicrobial protein suppressed biofilm formation during both …

Exploring The Antagonistic Polymicrobial Interaction Of Alcaligenes Faecalis With Prokaryotic And Eukaryotic Microorganisms, Aly Hargrave

Electronic Theses and Dissertations

Alcaligenes faecalis, a generally nonpathogenic, Gram-negative bacterium, has been observed by our laboratory to possess antagonistic activity against antimicrobial-resistant genera Staphylococcus, Candida, and Bacillus. This study focused on exploring the inhibition mechanism of A. faecalis against the three genera, with an emphasis on S. aureus. A library of A. faecalis transposon mutants was constructed and identified fourteen possible genetic factors linked to this inhibitory activity. Characterization of this inhibition indicated that A. faecalis suppressed S. aureus planktonic and biofilm growth via a contact-dependent mechanism, with pronounced effects during biofilm attachment phase. In a Caenorhabditis elegans …

Investigating The Role Of The Hypocretin/Orexin System In A Novel Model Of Polysubstance Dependence, Tyler Zarin

Electronic Theses and Dissertations

Substance use disorders (SUD) in the United States are steadily increasing. Potent and dangerous substances such as methamphetamine (MA) and fentanyl (FEN) are often co-used as a polysubstance (POLY), either intentionally or unknowingly as FEN is a common adulterant. SUD is characterized by physiological and psychological dependence involving the negative reinforcement of anhedonia and withdrawal which drive hypermotivated drug-taking behaviors. Current theory suggests that recruitment of hypocretin/orexin (HCRT) neuropeptide in reward and stress associated brain regions contributes to drug dependence. Despite strong evidence for HCRT’s role in mono-drug dependence, a relevant model for POLY dependence has yet to be developed, …

Initial Impacts Of Different Fertilizers On Improved East Texas Equine Pastures, Carolina De Leon, Brian Oswald, Leland Thompson, Candis Scallan

Electronic Theses and Dissertations

ABSTRACT

In Texas, approximately 1.6 million acres support an equine population exceeding 748,000 horses. This study assessed the effects of organic and inorganic fertilizer treatments on improved Bermudagrass (BG) and other vegetation (OTH) in overgrazed equine pastures at the Stephen F. Austin State University Equine Center. Treatments included equine manure (H), broiler poultry litter (P), and a commercial 13-13-13 fertilizer (C), with application rates based on pasture requirements.

Initial vegetation cover was evaluated using the Daubenmire cover class method in September 2024, followed by a 60-day undisturbed growing period. Final biomass (g/2ft² converted to lbs/ac) and percent cover measurements were …

The Impacts Of Management Practices On Industrial Hemp Chemistry, Physiology, And Microbiome Ecology., Allison Marie Rietman

Electronic Theses and Dissertations

Agroecology incorporates ecology and agronomy to inform crop management. Industrial hemp (Cannabis sativa L.) is a prime system to investigate agroecological questions because it has only recently been authorized for commercial cultivation and its sensitivity to biotic and abiotic stressors is unresolved. Here, I investigate how some conventional management choices, including the application of fungicide, plastic mulch, and irrigation, impact the physiology, chemistry, and microbial ecology of industrial hemp. Overall, I found that industrial hemp can be both resilient and resistant to these stressors, an important development for the industry. In Chapter II, I tested the impacts of fungicide application …

What Happens To Soil And Native Plant Life After Removal Of Lonicera Maackii In An Urban Temperate Forest?, Sheryl A. Gipson Hammond

Electronic Theses and Dissertations

In evaluating the potential effects of nitrogen cycles and pH on plant diversity and richness after the removal of Lonicera maackii in a temperate urban forest in Louisville, Kentucky, data was collected including nitrogen, pH, canopy, stem count, and plant surveys. The cutting and treatment with chemicals to remove L. maackii were successful one year after the treatments, but legacy effects ensued about five years thereafter. Native diversity waned as monoculture proliferated in some areas, including second invasions of the invasive. It was expected that nitrogen and pH would explain the success (or lack thereof) of native plant response as …

The Effects Of Geographic Isolation And Anthropogenic Activity On The Social Behavior Of Caribbean Green Monkeys., Rose Amrhein

Electronic Theses and Dissertations

Green monkeys (Chlorocebus sabaeaus) arrived to the Caribbean with the Trans-Atlantic slave trade. Since then, they have experienced unique environments to those of their native ranges in West Africa. Additionally, recent taxonomic changes within the genus make previous knowledge about the species hard to determine to be accurate. In this dissertation, I both assess some of the effects the island environment may have had on monkey behavior as well as build on the understanding of their vocal communication across three islands: Barbados, St. Kitts, and St. Martin. In chapter one, I investigate how human activity in Barbados affects …

Analyzing The Association Of Competitive Food Policy On Competitive Food Content In U.S. Schools., Mary E. Curnutte

Electronic Theses and Dissertations

OBJECTIVES: School food can have a profound effect on the population’s health. Thirty million children receive food at school and consume half their daily calorie intake at school. Competitive foods are foods sold outside of school breakfast and lunch, such as those sold in vending machines. A new ruling for Smart Snacks Standards, a set of competitive food guidelines, started in the school year 2014-2015. It is known that competitive foods undermine school lunch participation, and a decrease in school lunch consumption is associated with poorer student health. Additionally, an increase in competitive foods tends to be of nutrient-poor …

Sars-Cov-2 Modulates Pla2g2d/Pgd2 Signaling To Manipulate Host Immune Response To Increase Disease Severity., Dante L. Hamiel

Electronic Theses and Dissertations

Background: Previous studies suggested that SARS-CoV-2 infection could cause diverse immune and metabolic dysregulations, although the underlying mechanisms remain poorly understood. In addition, viruses may escape the immune response by modulating cellular metabolism, mitochondria, and protein functions indicating that immune or metabolic components may represent novel targets for anti-viral strategies. However, whether immune and metabolic disorders interact or affect each other waits to be determined. On the other hand, previous investigations identified the critical roles of a cell membrane-bound phospholipase PLA₂G2D and its downstream products PGD₂ in regulating the metabolism and inflammation in respiratory system. More importantly, …

Integration Of Multi-Omics Datasets Evaluating Structural And Functional Features Of The Gut Microbiome In People With Hiv (Pwh)., Aakarsha Vijayakumar Rao

Electronic Theses and Dissertations

Gut dysbiosis characterized by reduced abundance of beneficial butyrate-producing bacteria has been independently linked to HIV-1 infection and heavy alcohol drinking. Further, gut dysbiosis results in loss of gut barrier integrity, microbial translocation and host-specific systemic inflammation. Therefore, to evaluate the functional consequences of structural changes in the gut microbiome, integrated data analysis is imperative. In this dissertation, we perform integrated analyses using data from multi-omics platforms to examine the structural and functional features of the gut microbiome of PWH. Gut microbiome composition was evaluated by sequencing V4 region of 16S rDNA, concentrations of metabolites and host-specific immune markers were …