Life Sciences Commons^™

Application Of Path Analysis To Determine The Impact Of Age And Sex On The Neural Circuits That Promote Nicotine Withdrawal Severity, Veronika Espinoza

Open Access Theses & Dissertations

The rising prevalence of electronic cigarette (e-cigarette) use presents a major public health concern, particularly in adolescent females who are most susceptible to nicotine use and its long-term negative health consequences. The goal of this dissertation was to utilize preclinical rodent models to understand how group differences in age and sex influence neural activation patterns in brain circuits believed to promote nicotine withdrawal. Prior pre-clinical work, conducted largely in male rodents, has established that there are two major brain pathways that modulate the behavioral effects of nicotine withdrawal. These include the mesolimbic and medial habenula-interpeduncular nucleus (MHb-IPN) pathways. To assess …

Prediabetes Prediction Before Disease Onset Using Multimodal Health Data: A Machine Learning Approach, Luisa Veronica Gracia Mazuca

Open Access Theses & Dissertations

Prediabetes is a critical health condition that increases the risk of developing type 2 diabetes. The hemoglobin A1c (HbA1c) test diagnoses patients with prediabetes, but the disease has already caused metabolic alterations. Early detection is essential for timely interventions, and machine learning models offer a promising approach to identify prediabetic individuals through the analysis of biomarkers such as cytokines. We compared four classifiers-logistic regression, decision tree, random forest, and k-nearest neighbors - using cytokines (TNF-α, MCP-1, IL-1β, IL-6, IFN-γ), age, BMI, and waist-to-hip ratio (WHR). Models were evaluated using stratified 5-fold cross-validation and ROC-AUC. K-Nearest Neighbors (k-NN) achieved the highest …

Design And Optimization Of Peptide Inhibitors Targeting Kinesin: Molecular Modeling Studies And Virtual Screening For Therapeutic Candidate Development, Maraf Mbah Bake

Open Access Theses & Dissertations

Kinesins are ATP-driven molecular motors essential for intracellular transport and mitotic spindle assembly, and their mechanochemical behavior has been extensively characterized through computational tools. The first project reviews decades of advances in molecular dynamic simulations, including all-atom and coarse-grained molecular dynamics, Markov state models, Brownian dynamics, and free-energy approaches, which have collectively deepened our understanding of conformational transitions, microtubule-binding interfaces, and ligand interactions, especially for the mitotic motor Eg5. The second review examines the rapid emergence of quantum computing as a transformative technology for drug discovery, highlighting key historical milestones, recent progress in hybrid quantum-classical algorithms, quantum-enhanced docking, and quantum …

Novel Roles Of G-Beta-Gamma Signaling In Microtubule Dynamics And Neurodegeneration, Diana I. Olivas

Open Access Theses & Dissertations

Neurodegenerative disorders (NDDs), including Alzheimer's disease (AD), are characterized by progressive neuronal dysfunction, cytoskeletal disruption, and cognitive decline. Although Tau hyperphosphorylation and neurofibrillary tangle (NFT) formation are classical hallmarks of AD, emerging evidence suggests that microtubule (MT) dysfunction may precede and occur independently of Tau pathology. Understanding upstream regulators of MT dynamics is therefore critical for elucidating early mechanisms of neurodegeneration. Previous work from our laboratory demonstrated that G protein βγ (Gβγ) subunits directly interact with tubulin and promote MT assembly. However, the mechanism of Gβγ signaling in neuronal cytoskeletal stability and neurodegeneration remained poorly understood. The present study investigated …

Drug Repurposing Against Giardia Targeting Lipid Rafts, Extracellular Vesicles, And Sphingolipid Synthesis, Breanna Chantal Pence

Open Access Theses & Dissertations

Giardia lamblia is a protozoan parasite responsible for the intestinal disease giardiasis worldwide. Giardia is one of the major intestinal parasites in the world, with over 500,000 new cases annually. Symptoms of giardiasis include diarrhea, abdominal pain, and nausea. Children are particularly vulnerable to giardiasis, with cases of malnutrition, stunted growth, and cognitive impairment in countries where the disease is endemic. Giardia consists of two morphologic forms: an infective cyst which transmits the disease and a motile trophozoite which attaches to the epithelium of the small intestine during infection. Metronidazole is a common treatment for giardiasis, but cases of toxicity …

Determining Zap-70 Signaling Pathways Mediated By Ccr7 In Tcr T Cell Activation, Vivian Torres

Open Access Theses & Dissertations

Activation of T lymphocytes is the main event that occurs in the adaptive immune response after engagement of the T cell receptor (TCR) with the peptide of the major histocompatibility complex (pMHC) molecules that are demonstrated by antigen presenting cells [1]. A key step in this process is the recruitment and activation of the zeta chain associated protein of 70 kDa (ZAP-70). ZAP-70 couples TCR engagement to downstream intracellular signaling pathways through phosphorylation of tyrosine residues within intracellular tyrosine activation motifs (ITAMs) [2]. Although there have been extensive studies on the signaling response through TCR activation, the regulatory influence of …

From Soils To Plants And Back Again: The Effects Of Small Mammals On Arctic Ecosystem Processes, Andrew Uccello

Open Access Theses & Dissertations

Herbivores are essential drivers of above and belowground processes in ecosystems across the globe. Through their effects on ecosystem processes, herbivores represent a critical force shaping ecosystems undergoing rapid environmental changes, such as the Arctic. However, there are critical gaps in our knowledge of herbivores as drivers of Arctic ecosystem processes, especially concerning the role of small mammal herbivores. While previous research has made significant strides in identifying the role of small mammal herbivores as both top down and bottom up forces in Arctic ecosystems, we still lack an understanding that explicitly connects plant and soil responses to herbivory, especially …

Molecular Mechanisms Of Pfas Induced Protein Dysfunction: Implications For Neurodegenerative Risk, Daisy Lee Wilson

Open Access Theses & Dissertations

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with widespread human exposure and well-established links to adverse health outcomes. However, despite increasing epidemiological and experimental evidence, the molecular mechanisms underlying PFAS-induced neurotoxicity remain incompletely defined. This dissertation investigates PFAS toxicity across biological scales, integrating protein biophysics with neuronal cell models to elucidate pathways relevant to neurodegeneration. At the molecular level, we demonstrate that PFAS disrupts the structure and function of globular proteins, including the impairment of α-lactalbumin's calcium-binding capacity and of β-lactoglobulin's retinol binding, through concentration-dependent conformational destabilization. By applying these findings to a neuronal model, we show that …

Metabolomics In The Dryland Critical Zone: The Role Of Soil Metabolites In Phosphorus Acquisition, Kalpana Kukreja

Open Access Theses & Dissertations

Earth's Critical Zone (CZ) plays a key role in sustaining life through carbon, water, and nutrient cycling from the top of the canopy to the groundwater. A key feature of critical zone research is the integration of multiple interdisciplinary techniques. An emerging set of techniques that can add to this approach is the field of metabolomics, the quantification and study of comprehensive metabolite profiles. In this dissertation, I apply metabolomics to address knowledge gaps in dryland critical zone ecosystems, specifically how soil metabolite dynamics influence biogeochemical processes, and with a particular emphasis on phosphorus (P) cycling in the Chihuahuan Desert. …

Plant Communities Of Arid Ephemeral Stream Streams, Biogeographic Filters, Climatic Sensitivity, Urban Impacts Across Spatial And Temporal Scales, Luis Miranda

Open Access Theses & Dissertations

Ephemeral stream networks, locally known as arroyos, are among the most ecologically significant yet least protected habitats in arid landscapes. Despite supporting a disproportionately high plant biodiversity compared to surrounding uplands, these riparian systems lack regulatory protection in most arid U.S. states and face increasing pressure from urban expansion and intensifying climate change. There is an urgent need to understand how these factors influence riparian plant communities and hinder their ability to recover, enabling effective conservation and management strategies. In this dissertation, I explored the interplay of biogeographic gradients, precipitation variability, and urbanization in shaping arroyo riparian plant communities across …

Salience Network Circuit Dynamics In Distress Tolerance And Drug-Seeking Vulnerability, Marina Alicia Smoak

Open Access Theses & Dissertations

The psychological distress experienced during drug withdrawal can lead individuals with substance use disorder to abandon their goal of abstinence. Numerous human studies demonstrate that an inability to persist in challenging, goal-directed behavior while experiencing psychological distress is associated with multiple stages of substance use, including relapse. This behavioral construct is referred to as low distress tolerance (DT). Rodent models of DT similarly show that low DT predicts elevated cocaine relapse, particularly when DT is assessed following extended abstinence. This abstinence period corresponds with the incubation of craving, a phenomenon characterized by progressively increased cocaine-seeking over time. Importantly, relapse vulnerability …

High-Resolution Mapping Of Brainstem Feeding Circuits: A Framework For Targeted Neuroscience Tools, Geronimo Tapia

Open Access Theses & Dissertations

The neural control of energy balance is mediated in part by distributed brainstem circuits that integrate metabolic, visceral, and hormonal signals to coordinate appropriate motivated behaviors and autonomic responses. Despite extensive study, the precise neuroanatomical architecture regulating metabolism remains incompletely defined within standardized atlas frameworks. This work addresses that gap through complementary studies examining an acute glycemic challenge methodology known to stimulate feeding, the acute delivery of an anorexigenic-associated neurohormone, and the chemoarchitecture of a major feeding-related region, the parabrachial nucleus. First, utilizing 2-deoxy-D-glucose (2-DG) induced glucoprivation, we map the rapid response of dorsal medullary neuronal populations with high spatial …

Characterization Of The Antiviral Activity Of Mouse Schlafen Proteins, Wendy Paola Alvarez Leal

Open Access Theses & Dissertations

The goal of this work was to characterize the anti-viral role of mouse Schlafen8 and Schlafen9. Expression of these proteins is induced by type I interferon in response to viral infections. Importantly, their human functional orthologs exhibit anti-viral functions, and the structural element required for these activities are conserved in Schlafen8 and Schlafen9. Therefore, it is expected that these proteins will also impair viral replication. An important limitation in this field is that the anti-viral function of human SLFNs has been evidenced only in in vitro cellular models. No informative mutations have been described in human populations so far. Thus, …

Applying Motivational Interviewing-Based Health Coaching Within An Existing Exercise Referral Program: A Cost, Implementation, And Effectiveness Analysis, Zachary Joseph Friedman

Graduate Theses and Dissertations

Higher levels of physical activity (PA) are known to be associated with lower rates of chronic disease and better quality of living. However, population-wide deficits in PA continue to demand strategies for supporting PA-related behavior change. Health coaching represents a promising intervention strategy for behavior change, but its effectiveness in generally healthy, non-clinical populations is not clear. The purpose of this project was to evaluate the feasibility, cost, and effectiveness of integrating student-delivered, motivational interviewing (MI)-based health coaching into an existing university-based exercise referral program (ERP). Additionally, this study aimed to use students as health coaches, and to document training …

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …

Evaluating Management Strategies And Technology To Improve Grazing Efficiency, Thomas E. Aquino

Department of Animal Science: Dissertations, Theses, and Student Research

Increasing land costs and labor constraints continue to challenge beef producers. More intensive practices can increase harvest efficiency; however, many producers are deterred from implementing them due to increased labor and management considerations. Virtual fencing (VF) may provide a reduced labor alternative to traditional fencing for managing intensive grazing. This dissertation evaluated management strategies and VF technology to improve grazing efficiency of stocker cattle systems. In Experiment 1, VF was used to effectively manage groups of steers grazing in adjacent paddocks separated by only virtual boundaries. There was no difference in VF containment (99%) when steers were grazing co-fenced, with …

Decomposition Study Using Pigs In Southeastern Nebraska During The Fall And Winter Seasons, Ryan Bodine

Department of Anthropology: Theses and Student Research

When an individual is found deceased, one of the tools used in the identification process is estimating the post-mortem interval (PMI). This estimate is used to determine how long an individual has been deceased once their remains are found. To estimate an accurate PMI, knowing how decomposition is affected by external factors is key. The transition period from fall to winter in southeastern Nebraska consists of fluctuating temperatures as the seasons transfer from fall to winter. This thesis investigates how decomposition is affected during this transition period while also looking at two different environments that are common in Nebraska, prairies …

Exploring The Biocultural Profile Of The Undocumented Populations Of The Sonoran Corridor: A Skeletal Assessment Of The Prevention Through Deterrence Strategy, Mary A. Vaughn

Department of Anthropology: Theses and Student Research

Over the last thirty years the mortality rate of the undocumented population at the US-Mexico border has risen, requiring methods distinguishing US-born individuals from immigrants to improve the likelihood of identification and repatriation through foreign consulates. Forensic anthropologists with the Pima County Office of the Medical Examiner (PCOME) have advocated for the use of the biocultural profile, combining the biological profile with factors including oral health, osteological stress, and personal effects. The biocultural profile serves two purposes, functioning both as a tool for identification and with which to document structural inequality within communities of origin.

This study examines changes in …

Intraday Cotton Futures Price Responses To World Agricultural Supply And Demand Estimates (Wasde) News, Owen Mclane Tyrone

Graduate Theses and Dissertations

Price discovery in agricultural futures markets is augmented by information about supply and demand, leading markets to react when public reports are released. Effective price discovery in futures markets is vital to allocate physical commodities across time, synthesize information, and provide hedging tools. Price discovery in cotton markets is unique because it is less liquid than many other commodity markets. Therefore, our objective is to measure the initial price response in the cotton futures market to unanticipated ending stocks information in the WASDE report; then determine if markets continue to adjust after the initial price change. To meet our objective, …

Nadh Flim Reveals Cellular Bioenergetics And Mitochondrial Morphology During Drosophila Convergent Extension, Maria Espana Pena

Graduate Theses and Dissertations

Mitochondria are dynamic organelles that can fragment or fuse to support different bioenergetic demands and cellular processes, although the role of mitochondrial fission and fusion during embryonic development is not well understood. Fluorescence lifetime imaging (FLIM) of the mitochondrial cofactor NADH can be used to visualize mitochondrial networks and infer aspects of cellular bioenergetics in a label-free manner. We used NADH FLIM to test whether germband cells undergo changes in cellular metabolism during Drosophila convergent extension (CE)––a process in which hundreds of epithelial cells undergo coordinated intercalation to elongate the embryo. Contrary to our expectations, we did not observe significant …

Exploring Agricultural Pathways: An Analysis Of Arkansas Community Colleges, Natasha Hightower

Graduate Theses and Dissertations

As demand for a highly skilled agricultural workforce continues to grow, Arkansas must strengthen accessible and clearly defined academic and career pathways to prepare future agricultural professionals. Community colleges serve as a critical entry point into higher education, particularly for rural and first-generation students, and play a vital role in both workforce development and transfer preparation. However, information related to agricultural education offerings, transfer pathways, and faculty at Arkansas community colleges is often decentralized and difficult for students and stakeholders to locate. The purpose of this study was to examine agricultural education offerings at community colleges in Arkansas, specifically agricultural …

Genomic Surveillance Of Guillain–Barré Syndrome-Associated Genes In Campylobacter Jejuni Across Human And Non-Human Reservoirs, Emma Doughty

Biological Sciences

Campylobacter jejuni is a leading cause of foodborne illness and a major trigger of Guillain–Barré Syndrome (GBS), an autoimmune neuropathy caused by molecular mimicry between bacterial lipooligosaccharides (LOS) and host nerve gangliosides. While prior genomic studies have focused primarily on human clinical isolates, the prevalence and distribution of GBS-associated genes in non-human reservoirs remain poorly characterized. This study used genomic datasets derived from analyses of human and non-human C. jejuni isolates to assess the distribution of GBS-associated genes, with a focus on the neuABC sialylation pathway. Results demonstrate that these genes are present in both host types, across multiple geographic …

Alternative Abl1 Isoform Expression In Oncogenic Translocations: Implications For Cancer Progression, Jessica Teague

Biological Sciences

Abstract (also on poster): Previous studies in our lab show that an alternate isoform of Bruton’s tyrosine kinase, BTK-C, is required for the survival of several epithelial-derived cancer cells. BTK-C is transcribed from an alternative promoter and includes a 34-amino-acid N- terminal extension with a palmitoylation sequence that alters its subcellular localization. Nine other human kinases have similar alternative N-termini (ANT), often producing palmitoylated or non-palmitoylated isoforms from different transcriptional start sites. Among these, ABL1 is a known oncogenic kinase and key drug target. Translocation mutations at the 5′ end of ABL1 are a major cause of adult leukemias. This …

Donor And Recipient Microbiome Interactions Determine Functional Outcomes Of Fecal Microbiota Transplantation For Clostridioides Difficile Infection, Sophie A. Millard

All Dissertations

Clostridioides difficile is a major cause of healthcare-associated diarrhea. Infection typically occurs after antibiotic treatment disrupts the gut microbiome, allowing C. difficile to colonize and produce toxins leading to disease (CDI). Standard antibiotic treatments can resolve acute infection but frequently lead to recurrence, highlighting the need for alternative strategies that restore the gut ecosystem. Fecal microbiota transplantation (FMT), the transfer of stool from a healthy donor, has emerged as an effective therapy for recurrent C. difficile infection (rCDI). Understanding the mechanisms underlying the success of FMT for treatment of rCDI could lead to safer, more defined microbial mixtures.

This dissertation …

High Throughput Phenomics Pipeline For Pulse Crop Nutritional Breeding, Amod Udayanga Madurapperumage

All Dissertations

Dry pea (Pisum sativum L.), lentil (Lens culinaris Medik.), and chickpea (Cicer arietinum L.) are major pulse crops valued for their high nutritional composition and importance to global food systems. Pulses are rich in carbohydrates, protein, and essential minerals, making them ideal whole foods and critical contributors to food and nutrition security. Due to these advantages, pulse breeding programs are increasingly focusing on enhancing nutritional traits, such as protein quality, amino acid balance, and micronutrient density, through the process of biofortification. However, improvement of agronomic traits remains equally essential. Characteristics such as plant height, standability, stress tolerance, …

Integrating Incentive Design And Spatial Prioritization For Climate-Smart Forestry Adoption In South Carolina, United States, Miah Maye Pormon

All Dissertations

Forests provide essential ecosystem services, including carbon sequestration, water regulation, timber production, and habitat provision. However, increasing development pressures and land-use changes threaten forest persistence and long-run ecosystem service provision. Climate-smart forestry (CSF) practices, such as improved forest management and extended rotation, offer opportunities to enhance carbon storage, forest resilience, and economic livelihoods. The effectiveness of these practices depends on forest owners’ participation and the strategic allocation of financial resources or incentives. This dissertation develops an integrated framework that combines behavioral economic analysis and mapping to improve the design of current incentive programs. The first chapter employs the Contingent Valuation …

Redeveloping Mississippi: A Case Study On Brownfields In Central & Southern Mississippi, Sahrah R. Yeroozedek

Master's Theses

Brownfields, or properties that are or possibly are contaminated with dangerous materials, represent a common obstacle for communities in Mississippi. The real or potential presence of contaminants at these sites often deters investors due to costly cleanup requirements (EPA, n.d. -b). The Environmental Protection Agency (EPA), through its Brownfield Revitalization Program, implemented guidelines for covering the costs and labor associated with the remediation of these properties. The EPA is not, however, responsible for redevelopment that supports long-term environmental and economic sustainability. Although the EPA maintains inventories of all Brownfields, there is also no comprehensive database of Brownfields and their current …

Creatures Of Habit? Impact Of Chick Feeder Tray Location On Feed Consumption At 0-7 Days Of Age, Emily Kate Green

Graduate Theses and Dissertations

Early chick nutrition is critical for establishing target growth performance characteristics in broiler chickens. This study evaluated factors within commercial broiler houses that potentially influence feed consumption during the first 7 days. Three trials were conducted in a 12.2 x 122 m commercial broiler house to assess the effects of house sectioning, spatial barriers, and feedline location. In Trial 1, a one-way experimental design was used in which the house was divided into four equal sections using migration fencing every 30.5 m. House sections served as a fixed factor. Feed was provided using chick trays placed beneath the feed line …

Exploring The Spectrum Of Anxiety During Concussion Recovery: A Comprehensive Examination Of Symptom-Based Anxiety Disorders, Kori J. Durfee

Graduate Theses and Dissertations

Background: Anxiety is common following a concussion, arising from both psychosocial and physiological changes, and can manifest in diverse ways. Despite its complexity and association with worse outcomes, post-concussion anxiety is often assessed as a single construct. Characterizing anxiety presentations following injury may improve the identification of clinically meaningful symptoms and help inform future targeted interventions that can improve concussion outcomes. Purpose: The primary purpose was to determine if symptom-based anxiety disorders occur in adults with concussion and identify pre- and post-injury predictors associated with these disorders. Additionally, the clinical utility and predictive abilities of symptom-based anxiety disorders and variability …

Analyzing The Effects Of Message Testing On The Public's Opinion About Gene Editing In Agriculture And Medicine, Luke Sanford Wimpy

Graduate Theses and Dissertations

This paper will present results from the final survey of a multi-stage project examining factors that influence opinions about gene editing in agriculture and medicine. In this final survey, 3,200 U.S. respondents were recruited and randomized to view one of eight videos that communicated the safety of gene editing to determine which factors are most influential in changing opinions. The eight videos were designed based on data collected from focus groups and three previous surveys in this multi-stage project. The eight videos varied by three attributes: messenger, message, and application. The messenger in the videos was either a researcher or …