Life Sciences Commons^™

Neural Activity Within And Between Visual And Executive Areas Is Modulated Post-Locomotion In Rhesus Macaques, Sergey Egranov

Dissertations and Theses (Open Access)

Physical activity has been shown to benefit cognitive and mental health by improving cerebrovascular perfusion and regulating hormone-mediated processes on a systemic level. However, the acute effects of physical activity, such as locomotion, on the neuronal circuits underlying cognitive processes have yet to be fully characterized. This body of work seeks to rectify this gap in knowledge through analysis of how both behavioral performance and neuronal activity signatures in visual and executive brain regions are modulated post-locomotion in rhesus macaques.

To this end, we performed high-yield electrophysiological recordings simultaneously from area V4, a mid-tier visual cortical region, and the dorsolateral …

Investigating Metabolic And Mitochondrial Adaptations Triggered By Blood Flow During The Endothelial-To-Hematopoietic Transition, Paulina Horton

Dissertations and Theses (Open Access)

Hematopoietic stem cell (HSC) transplant is the standard of care for many hematologic diseases. However, many patients cannot benefit from this potentially curative treatment because they cannot find a suitable donor, contributing to a high level of unmet need. Recently, bona fide HSCs capable of robust engraftment and differentiation have been generated from iPSCs utilizing wall shear stress (WSS) to help promote HSC generation. However, the mechanisms through which WSS regulates hematopoiesis remain poorly understood. Scientists, therefore, continue to look for the mechanotransduction pathways that promote hematopoiesis, and key answers may lie in examining the role of extrinsic factors that …

Differential Progression Of Pancreatic Premalignancy In Geographically Distant Murine Transgenic Cohorts Uncovers Key Role Of Microbial Metabolites, Rian M. Howell

Dissertations and Theses (Open Access)

Cancer is a leading cause of death worldwide. Despite recent advances in diagnostic and therapeutic modalities, pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that remains highly lethal. Efforts have been made to increase the understanding of the underlying mechanisms driving early stages of tumor development, when the cancer is most susceptible to intervention. To this end, genetically engineered mouse models (GEMMs) have been developed with the mutations most commonly seen in the patient population. Expression of these mutations in select cellular compartments has resulted in the ability to recapitulate characteristics of human pancreatic cancer such as the development of …

The Evolving Changes In The Regionalization Of Export Bans On U.S. Poultry Trade From The 2015 And 2022 Highly Pathogenic Avian Influenza Events, Kylie A. Roesler

Graduate Theses and Dissertations

As food security becomes a growing concern worldwide in a trading system dominated by globalization, the safeguarding of a bio-secure food system is at risk. One of the greatest risks to this stability of the system is, highly pathogenic avian influenza or HPAI which is growing in frequency and impact. Therefore, the global response to disease events is evolving into a newfound understanding of disease prevalence across the animal protein industries. This study will analyze the 2022 HPAI event in the United States regarding the regionalization of restrictions imposed by trading partners accounting for trade agreements executed. The examination of …

Physiological And Molecular Responses Of Diverse Rice Genotypes Under Drought Stress, Huda Mohmmed Alshaya

Graduate Theses and Dissertations

Climate change-induced drought stress is a significant constraint on global rice (Oryza sativa L.) production, threatening food security. This study evaluated the drought resilience of 15 diverse rice genotypes from the USDA mini-core collection under field, greenhouse, and osmotic stress conditions. Field trials assessed reproductive-stage drought tolerance based on panicle length (PL), number of spikelets per panicle (NSP), and spikelet sterility (SS). Greenhouse experiments examined moisture retention at the vegetative stage. Significant genotypic variation was observed, with genotypes 310724, 310779, 311181, 311603, 311793, and Vandana exhibiting drought tolerance through stable PL and SS. Additionally, genotypes 310100, 310428, 311255, N22, …

Ecological Specialisation Of Reef Fishes Peaks In Global Biodiversity Hotspots, Zoé Delecambre, Renato A. Morais, Alexandre C. Siqueira, Emma Paul Costesec, Caroline E. Dubé, Sergio R. Floeter, Alan M. Friedlander, Fabien Leprieur, Yves Letourneur, Lucas T. Nunes, Jordan M. Casey, Valeriano Parravicini

Research outputs 2022 to 2026

Aim: The role of ecological specialisation in shaping biogeographic and evolutionary patterns remains unresolved. To date, few studies have quantitatively examined consumer niche breadth at a global scale. We describe global biogeographic and diversification patterns of specialisation, measured using trophic and thermal niches, for a highly diverse assemblage of consumers: reef fishes. First, we investigated the confluence of specialisation with global biogeographic patterns in species richness and reef area. Then, we tested whether these patterns could be explained by differences in diversification rates and geographic ranges. Location: Tropical reefs across the globe. Time Period: Present. Major Taxa Studied: Reef fishes. …

Clostridioides Difficile In Feral Horse Populations In Australia, Natasza M.R. Hain-Saunders, Daniel R. Knight, Andrea Harvey, Mieghan Bruce, Brian A. Hampson, Thomas V. Riley

Research outputs 2022 to 2026

Clostridioides difficile is a known cause of diarrhea and colitis in human and non-human animals. While C. difficile is regularly isolated from domesticated horses, little is known about its prevalence in wild or feral populations. In Australia, the horse population encompasses a mix of both domesticated and feral animals, with the feral population of 400,000 estimated to be the largest in the world. This study investigated the presence and characteristics of C. difficile in Australian feral horses and evaluated their potential as a source or reservoir of C. difficile in the wider community. Fecal samples (n = 380) were collected …

Comparison Analyses Of Consumer Acceptance, Evoked Emotions, And Purchase Intent Between Gluten-Containing Versus Gluten-Free Chocolate Chip Cookie Products, Shaelyn Frauenhoffer, Eniola Ola, Suzanne Jervis, Susan E. Gauch, Han-Seok Seo

Food Science Faculty Publications and Presentations

The demand for gluten-free products has increased significantly over the past few decades. This study aimed to determine differences in consumer acceptance, emotional responses, and purchase intent between gluten-containing versus gluten-free chocolate chip cookies. Twelve commercially available chocolate chip cookie products from 11 brands were evaluated, including 7 gluten-free and 5 gluten-containing options. Eighty-nine participants without celiac disease took part in this 2-day study, evaluating six cookies per day. Participants rated sensory acceptance (appearance, flavor, texture, and overall liking) using a 9-point hedonic scale and evaluated specific sensory attributes (chocolate flavor, sweetness, chewiness, and hardness) using a 5-point just-about-right (JAR) …

Advancing Marine Animal Movement Studies Using An Open Innovation Framework, Jacob Levenson

Graduate Doctoral Dissertations

This dissertation investigates the application of open innovation to migratory marine animal movement studies, addressing critical challenges in understanding, managing and ultimately conserving highly mobile and migratory species (HMMS). The species examined herein, including manta rays, sea turtles, and marine mammals, face threats including habitat disruption and behavioral changes to adapt to anthropogenic stressors. Traditional monitoring techniques, while valuable, are often costly, limited in scale, and protected by proprietary intellectual property, all of which decrease accessibility. Ambitious conservation goals, such as protecting 30% of the ocean by 2030, require more data that are indubitably sharable and thus will need to …

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, …

Impacts Of Reef Fish Length On Foraging Radius: Exploring Behavioral Patterns Within A Patch Reef Ecosystem, Kilia Brawand

Undergraduate Honors Capstone Projects

Reef fish exhibit various behaviors upon the Great Barrier Reef. One of these behaviors includes that of limiting their grazing distances from a patch reef refuge to a certain maximum distance in order to avoid predators. This is defined as a ‘foraging radius’ or ‘margin of safety’. This ‘foraging radius’ varies among fish due to many factors- including species, morphology, ontogenesis, habitat complexity, and importantly: speed. Quicker fish can outswim predators to safety more efficiently than slower fish, and can therefore afford to travel farther distances to forage. Speed varies among fish for a number of reasons, including fish size …

Transcription Factor Y- Box Binding Protein 1 (Ybx1) Enhances Sorafenib Resistance And Tumorigenic Capacities In Hepatocellular Carcinoma (Hcc), Dennis Kwabiah

Theses and Dissertations

Hepatocellular carcinoma (HCC) is the most common liver cancer, with early-stage cases potentially benefiting from surgical treatments like liver transplantation and hepatectomy. However, advanced HCC stages have poor prognosis due to resistance to therapies, especially sorafenib, a tyrosine kinase inhibitor approved for late-stage HCC. Despite its clinical use, sorafenib has limited efficacy in prolonging survival, and the mechanisms of resistance remain unclear. Analysis of The Cancer Genome Atlas (TCGA) HCC dataset shows elevated Y-box binding protein 1 (YBX1) expression in HCC tumors compared to normal liver tissues. Previous studies have indicated that YBX1 is involved in drug resistance in various …

Climate Change And The Field Of Farm Labor In The Lower Rio Grande Valley, Texas, Cody Richard Mortell

Theses and Dissertations

Farm workers in the United States are often vulnerable to adverse impacts of climate change, particularly extreme heat. This study explores farm workers’ climate change perceptions (CCP) as a mediating force in climate adaptation. Using latent class analysis, in-person survey data (n=404) from Lower Rio Grande Valley, TX (2024) and NOAA data were analyzed. Results were interpreted using Bourdieu’s field analysis framework and his notions of capital and symbolic power. Findings include: a social hierarchy with three latent classes of workers based on economic, cultural, social, and symbolic capital, which statistically significantly affected CCP. Workers in higher structural positions were …

Structural Stability Of Fgf1-Fgf2 Dimer Established Via Salt Bridges With Mutation K296q, Ashleigh Letterman

Chemistry & Biochemistry Undergraduate Honors Theses

Fibroblast Growth Factors (FGFs) are a family of cell-signaling proteins. FGF, specifically the FGF-1 subfamily, which contains FGF-1 and FGF-2, is important in several biological functions such as wound healing, cell proliferation, and angiogenesis. FGF-1 has cell proliferation properties and FGF-2 has angiogenic properties. These FGFs have great potential for wound-healing therapy medications...

Under Embargo: Available for viewing on Friday, May 01, 2026

Activity-Based Protein Profiling On Nucleophilic Amino Acid Residues With Pyrocarbonates, James Van Horn

Chemistry & Biochemistry Undergraduate Honors Theses

The complexity of the proteome requires strategies that efficiently characterize protein functions. Activity-Based Protein Profiling (ABPP) is a method that identifies enzyme activity by targeting key catalytic residues. This study focused on histidine, a residue involved in enzymatic catalysis, metal coordination, and protein-protein interactions. Despite its importance, histidine-specific chemical probes are limited due to its variable reactivity. This work developed and characterized a histidine-specific probe using a pyrocarbonate-based mechanism. Singleresidue assays confirmed selective reactivity of the probe with histidine over other nucleophilic amino acids. Further testing on enzymatic proteins and lysed cell proteomes showed that the probe modified histidine residues …

Impact Of Invasive Pine Trees And Their Ectomycorrhizal Fungi Symbionts Upon The Properties And Functions Of Soils In Southern Hemisphere Eucalyptus Forests, Jack T. Baker

Honors Theses

P. radiata trees are invading Southern Hemisphere Eucalyptus forests within New Zealand and southeastern Australia, resulting in a novel codominant forest system. This codominant invasion is unique relative to other pine invasions throughout the Southern Hemisphere. Ectomycorrhizal fungi (EMF) play an important role in all pine invasions and are found within each instance of invasion. The impact of ectomycorrhizal fungi and Pinus trees upon the properties of the soil within Eucalyptus forests is not very well studied nor understood. Our study sought to provide insight into the implications of this invasion upon the soil, and consequently the ecosystem as …

A Sex Comparison On The Effects Of Caveolin Scaffolding Domain On Fibrosis Formation After Chronic Sympathetic Stimulation, Crimsyn Price

Undergraduate Honors Theses

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. There are various trends that influence the rates of cardiovascular disease in each country. Factors that create these trends involve diet, exercise, genetics, socioeconomic status, and geographical location. Additionally, CVD is typically higher in middle-income and lower-income classes. Hospital routes, rates of poverty, insurance policies, and lifestyle culture are all factors that can impact the time of treatment which in turn affect the rate of CVD. However, we explored in this study the shift in CVD women experience after menopause. Women were excluded from clinical trials until 1986, and the …

Sliding Window Method For Simulating Action Potentials In Axons, Hayden Reed

Honors Theses

ABSTRACT Hodgkin and Huxley’s nonlinear partial differential equations model the excitation and propagation of action potentials in neurons, and there have been numerous attempts at finding the best numerical solution method. This thesis proposes a novel approach to solving these equations: the Sliding Window method, in which a fixed sub-interval is found through capturing the signal’s head and tail. The system is then solved on the sub-interval instead of the entire interval. Using the Sliding Window technique also involves implementing the backward and forward Euler methods and the finite difference method. It will be demonstrated that, in utilizing the Sliding …

Investigating Self-Healing Mechanisms In Host-Pathogen Interactions: A Literature Review Of Macrophage Functions In Tuberculosis, Blessing Savusa

Open Access Theses & Dissertations

Tuberculosis (TB) remains a leading cause of mortality, particularly in underdeveloped regions. Mycobacterium tuberculosis (Mtb) is regarded as one of the most successful pathogens due to its ability to evade host immunity and persist within granulomas. Macrophages are the first-line host defenders that engulf Mtb into phagosomes, which initiates lysosomal activity for degradation. However, the virulence factor of Mtb is able to inhibit phagolysosome fusion. The host immune system forms granulomas to contain the mycobacterium at the site of inflammation. This, in turn, causes a necrotic state and causes tissue damage from the prolonged inflammation. Studies suggest that the host's …

Computational Framework For Integrating Single Nucleotide Variant Scores To Identify Novel Genes In Cancers, Amanda Maria Bataycan

Open Access Theses & Dissertations

A quantitative integrated scoring function, iQ(G) was developed to assess the cumulative effects of nonsynonymous single nucleotide variants (SNVs) on the protein-coding genes with the goal to find novel candidate cancer-related genes from patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and ovarian cancer (OC). With Genomic Data Commons as primary data resource for this project, whole-exome SNV data were extracted on patients with one of these three cancers. For each specific cancer, the iQ(G) function sums up the deleterious effects of individual SNVs with respect to the transcripts of the gene G in which they occur, weighted …

Leveraging Predictive Analytics To Improve Prognostic Models For Uterine Cancer, Arnav Joshi

Open Access Theses & Dissertations

Uterine Corpus Endometrial Carcinoma (UCEC) presents notable disparities in incidence and outcomes across racial groups, warranting deeper investigation through transcriptomic and predictive modeling approaches. This thesis presents a comprehensive transcriptomic analysis of RNA-Seq data from 177 individuals, comprising both tumor and control samples, specifically from the UCEC_CN_High molecular subtype. The cohort was stratified by race, focusing on differences between Black and White individuals to explore race-associated gene expression patterns. To uncover genes with prognostic significance, LASSO (Least Absolute Shrinkage and Selection Operator) regression was applied for feature selection, identifying a subset of genes most strongly associated with overall survival. These …

The Bullied Prairie Vole: Modeling Depression And Anxiety Through Social Defeat Stress, Minerva Rodriguez

Open Access Theses & Dissertations

Stress-induced illnesses, such as major depression and anxiety, are significant global causes of disability. This highlights the need for reliable animal models that accurately mimic social stress-induced maladaptations, thus, allowing the experimental study of the etiology of such disorders. Prairie voles (Microtus ochrogaster), known for their human-like bi-parental behavior and monogamous partner preferences, are a relevant model for the study of stress-induced psychopathologies. For this reason, in this dissertation, I examined whether exposing voles to the social defeat stress (SDS) paradigm, an experimental approach that captures bullying behavior, would result in both depression and anxiety-related profiles. To do this, experimental …

Regulation Of Ccr7 Signaling Events By G-Protein-Coupled Receptor Kinases 2 And 3, Anahi Sanchez

Open Access Theses & Dissertations

G protein-coupled receptors (GPCR) can bind multiple ligands, leading to differential signaling events termed biased signaling. C-C chemokine receptor 7 (CCR7) is a GPCR known to have biased signaling between the two ligands it binds to, CCL19 and CCL21. Binding of C-C Chemokine Ligand 19 (CCL19) promotes a high level of CCR7 phosphorylation, while CCL21 leads to a much lower level of CCR7 phosphorylation; findings observed in HEK and dendritic cells. GPCR kinases (GRKs), which can control the phosphorylation patterns of a GPCR, are hypothesized to regulate biased signaling of a receptor. GRK expression differs between cell lines and cell …

Ghrelin And Decision-Making: Exploring Its Role In Food Reward, Novelty-Seeking, And Cost Valuation, Serina A. Batson

Open Access Theses & Dissertations

When low energy levels are detected, Ghrelin, a peptide hormone, is produced in the fundus of the stomach. Referred to as the "hunger hormone", Ghrelin is traditionally associated with increased food intake and blood sugar levels. A key modulator in the gut-brain interaction, Ghrelin's growth hormone secretagogue receptor can be found widely across the cortico-striosomal circuit. Critical for decision-making, Ghrelin-based manipulation of this circuit can directly affect reward and cost valuation. While Ghrelin is uniformly considered to increase the valuation of food-based rewards, little research has explored its impact on non-food-based rewards or its effects on cost valuation. Therefore, to …

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 …

Identifying Microbial Complexities And Control Strategies At Pre-Harvest Poultry Production, Tolulope Tiwa Ogundipe

Graduate Theses and Dissertations

While significant progress has been made in post-harvest control of Salmonella in the poultry industry, the development of effective pre-harvest intervention strategies remains critical for reducing foodborne pathogens. Environmental reservoirs such as poultry litter and drinking water systems (DWS) are potential harborage sites for Salmonella and other microbial communities. Understanding the microbiota of these environments, including biofilms within water lines, is essential to identifying factors contributing to Salmonella colonization and improving pre-harvest control approaches. This study aimed to evaluate the incidence and quantity of Salmonella in poultry litter and water lines, characterize the microbial populations in these environments, and assess …

Flexible Microelectrode-Based Impedance Immunosensor For Rapid Detection Of E. Coli O157:H7, Sonatan Kumar Biswas

Graduate Theses and Dissertations

Abstract Food contamination poses a significant threat to public health, the economy, and human health worldwide, occurring at any stage of the food supply chain, from farm to fork. Escherichia coli 0157:H7, recognized as one of the principal causes of foodborne illness, poses a considerable risk to food safety. The primary objective of this investigation is to devise a flexible microelectrode-based immunosensor capable of swiftly identifying E. coli O157:H7 cells without the need for incubation in a pure culture environment. In the development of the biosensor, the gold electrode (composed of 50% Au) underwent an initial coating process involving 2-aminoethanethiol/cysteamine, …

Evaluation Of Fluridone In Rice, Maria Carolina De Carvalho Rocha Souza

Graduate Theses and Dissertations

The increasing pressure of Palmer amaranth [Amaranthus palmeri (S.) Watson] in rice (Oryza sativa L.) fields demands new chemical control options to manage this weed. The recent labeling of fluridone on this crop from the three-leaf rice stage offers an additional residual herbicide for battling Palmer amaranth; however, research is needed to evaluate its effectiveness and rice tolerance. Field experiments were conducted to evaluate Palmer amaranth control and rice tolerance to fluridone across different locations in Arkansas in 2022, 2023, and 2024. Preemergence (PRE) applications of fluridone at 168 g ai ha^⁻1; (1× label rate) and 336 …

Crispr-Cas9 Integration Of Salmon Elovl2 In Zebrafish Enhances Lc-Pufa Biosynthesis And Growth Across Diets, Waleed Sami J. Al-Bachry

Graduate Theses and Dissertations

Fish are a rich source of EPA and DHA, which are well-known long-chain polyunsaturated fatty acids (LC-PUFAs). The sustainable production of these essential fatty acids poses significant challenges, mainly due to our dependence on marine fish and certain nuts. CRISPR-Cas system was utilized to insert the elongation of long-chain fatty acids-like2 (Elovl2) gene from Salmo salar into Danio rerio. Elovl2 was introduced at 10-15-minute post-fertilization, and successful integration confirmed by PCR genotyping, sequencing and expression of EGFP. Approximately 67% of injected embryos successfully exhibited EGFP and sequence results verified the gene integration of Salmo salar Elovl2 at the first start …

Variation In Stress Response Regulation Across Natural Isolates Of Saccharomyces Cerevisiae, Crystal Christine Crook

Graduate Theses and Dissertations

The stress response of Saccharomyces cerevisiae is a valuable area of study for understanding cellular adaptation mechanisms that govern survival in fluctuating environments. This dissertation investigates stress response regulation in yeast through the roles of Hog1 mitogen-activated protein kinase (MAPK) and the post-transcriptional regulator Mkt1, a key post-transcriptional regulator, in diverse wild yeast isolates. Hog1 is traditionally known for its central role in osmotic stress regulation in the high-osmolarity glycerol (HOG) pathway. This study expands the functional scope of Hog1 to include oxidative and ethanol-induced stress responses.

In parallel, we investigate post-transcriptional regulation of stress responses by the Mkt1 interactome, …