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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 …

Evaluation Of Palm Oil As An Ingredient In Finishing Beef Cattle Diets On Performance, Carcass Characteristics, And Meat Quality, And The Composition Of Spayed Heifers To Intact Heifers Fed Melengestrol Acetate On Feedlot Performance And Carcass Characteristics, Tate S. Johnson

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

Heifers represent a large proportion of cattle placed in feedlots, making pregnancy management an important consideration for maintaining performance and carcass value. Melengestrol acetate (MGA) is commonly included in feedlot diets to suppress estrus and prevent pregnancy in intact heifers during the finishing period. Alternatively, spaying has historically been utilized as a management practice to allow heifers to graze alongside breeding cattle without the risk of pregnancy. Despite its historical use, there is limited contemporary research comparing the growth performance and carcass characteristics of spayed heifers with intact heifers managed with MGA under modern feedlot conditions. Therefore, a commercial study …

Optimized Ultrasound Imaging Of Phase-Change Nanodroplets, Charles R Dyall, Dmitry Nevozhay, Andy Liu, Trevor M Mitcham, George J Lu, Konstantin V Sokolov, Richard R Bouchard

Faculty, Staff and Student Publications

Phase-change nanodroplets (PCNDs) continue to generate significant research interest due to their potential to extravasate into tissue, to be targeted for molecular imaging and drug delivery, and to undergo an induced phase-change to "activated" microbubbles (MBs) for ultrasound (US) imaging. To accurately quantify molecular markers, however, one assumes a consistent proportion of PCNDs in a region of interest (ROI) are stably activated and imaged. Herein we present a framework for developing a diagnostic sequence that is optimized for PCND activation uniformity, contrast, and acquisition time. To develop this framework, activation was examined at three scales of increasing complexity: single, adjacent, …

Potential Impact Of Parasites In The Transmission Of Chronic Wasting Disease, Paulina Soto, Rodrigo Morales

Faculty, Staff and Student Publications

No abstract provided.

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 …

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 …

Unravelling Taxonomic Complexity In Elusive Cetaceans: Mitogenome Insights Into Evolutionary History And Cryptic Diversity Of Bryde's Whales, Dominique Paynee, Paulette Bloomer, Gwenith Penry, Simon Elwen, Ada Natoli, Vaisakh Dhanalakshmy, Thyago Cardoso, Els Vermeulen

All Works

Cetaceans, despite their ability to cross wide distances, enabling mostly high levels of gene flow, can develop unique genetic lineages driven by variations in life-history traits, diverse migratory routes and local adaptation, complicating taxonomy and delineation of conservation units. Comprehensive genetic data are essential to overcome the challenges of obtaining suitable sample sizes from wild cetaceans while untangling cryptic species diversity. The Bryde's whale (Balaenoptera edeni) has a complicated discovery and taxonomic history that hinders accurate conservation assessments. In southern Africa, two populations are recognised: the inshore (SAi) and the offshore southeast Atlantic population (SEA). This study examines their phylogenetic …

Cell-Type Specific Control Of Visual Fixation In Drosophila Melanogaster, Meagan Leung

Biological Sciences

Navigation in complex environments requires precise visual processing. To move effectively through their surroundings, animals must orient toward and maintain fixation on objects of interest to preserve a stable heading. However, the neural mechanisms underlying this behavior remain poorly understood. We use Drosophila melanogaster as our model organism because its visual behavior can be precisely measured and the availability of genetic tools which enables us to perturb the underlying neural circuits. Using a closed-loop virtual reality environment combined with locomotion tracking, we developed a stimulus protocol that reliably elicits fixation responses. To determine whether specific visual neurons drive fixation responses, …

Impact Of Salt Block Utilization During Dry-Aging On Pork Loin Microbial And Meat Quality, Cason H. Frisby

Food Science Undergraduate Honors Theses

This study aimed to investigate the effects of dry-aging and salt block utilization during dry aging on pork loin quality attributes. Pork loins were collected at 7 days postmortem, cut into three equal sections, and randomly assigned to wet aging (WA), traditional dry-aging (DA), and salt block dry-aging (SDA) groups to be aged for 28 days. During the dry-aging period, SDA cabinet exhibited lower humidity fluctuation (Avg. 71.52, St. Dev. 4.7) compared to DA cabinet (Avg 70.76, St. Dev. 7.9). Following the aging period, no differences were found in pH or Warner Bratzler shear force values between treatments (P>0.05). …

Precision To Protein: Comparative Characterization Of Printability, Physicochemical, And Nutritional Properties Of Cricket, Pea, And Whey Proteins In 3d-Printed Nutrition Bars, Sophia Hinkebein

Food Science Undergraduate Honors Theses

Protein is a priority nutrient in the American diet, being fueled by the demands of weight loss drugs, diet culture, and new dietary guidelines. However, meeting these elevated protein goals sustainably requires diversifying beyond standard sources like whey protein isolate. 3D printing offers an opportunity to present a variety of protein sources in a palatable, customized, and consumer-acceptable format. In this study, 3 protein sources (cricket, whey, and pea), were optimized within food inks for 3D printing. Optimization involved different hydration levels, with whey requiring 7 grams of added water, cricket 22 grams, and pea the most at 47 grams. …

Mammalian Biodiversity Of The Easley Conservation Stewardship Area, Grayson C. Belt

Honors College Theses

Monitoring wildlife is an important part of conservation and is particularly vital for newly acquired conservation areas to provide a baseline of what is present. In 2025, the 22 ha Murray State University Easley Conservation Stewardship Area (MSU ECSA) was established following a donation to the university by Melissa Easley. I conducted a survey using trail cameras at the ECSA in fall 2025 and winter 2025/26 to record mammalian diversity. The survey consisted of two subprojects: a mesomammal subproject of 18 knee height trail cams and a small mammal subproject using 15 custom small mammal bucket cameras. I uploaded all …

Landscape Connectivity And Wildlife Access To Water Across An International Border: Barriers And Opportunities For Facilitating Transboundary Movement, Bogdan Chivoiu, Erin L. Koen, Michael J. Osland, Christopher A. Gabler, Jerald T. Garrett, Ernesto Reyes, Stephanie A. Bilodeau, Mitch A. Sternberg, Jude A. Benavides, James Martinez

School of Earth, Environmental, & Marine Sciences Faculty Publications

Rapid global acceleration in the construction of physical barriers along international borders has greatly influenced biodiversity and animal movement. Physical barriers can fragment landscapes, hinder access to essential resources, impact long-distance migrations, and inhibit dispersal and gene flow. The effects of physical barriers on animal movement and landscape connectivity can be exacerbated in dryland environments where access to water is a limiting factor. In recent decades, the construction of border barrier infrastructure has accelerated along the international boundary between the United States and Mexico. Here, we used a landscape connectivity model to investigate the effects of barriers on wildlife access …

Foraging Plasticity And Mercury Contamination In Red-Legged Kittiwakes: A Multiple Stressor Perspective, Sam E. Clay

All-Inclusive List of Electronic Theses and Dissertations

Arctic seabirds are facing increasing stress from climate change, yet the interactive effects of multiple stressors on behavior remain poorly understood. Adopting a multiple stressor perspective promises to advance understanding of avian behavioral responses to climate change, as climate change is exposing Arctic and subarctic animals to a complex set of stressors rather than a single stressor in isolation. Using the red-legged kittiwake (Rissa brevirostris) as a model, I examined how multiple stressors, including mercury (Hg) exposure, shifting wind conditions, and varying foraging conditions linked to sea surface temperature (SST) may interact to constrain behavioral plasticity and energetically expensive behavior …

Microplastic Composition And Exposure Pathways In Freshwater Systems: A Multi-Matrix Comparison Between Streams And Retention Ponds In Hamilton County, In, Mya Whaley

All-Inclusive List of Electronic Theses and Dissertations

Since the early 1900s, the use of plastics has increased exponentially. The breakdown of plastic materials has exposed all ecosystems to microplastics (small particles of plastic < 5 mm), which are now ubiquitous in natural settings. Microplastics have a relatively large surface area, and many chemicals adsorb to these small particles, impacting their fate and transport of pollution. While microplastics have been found in virtually every setting on Earth, research is necessary to understand their impact on freshwater ecosystems and biogeochemical cycles. The focus of this research was to investigate microplastic compositions in crayfish, sediments, and water samples collected in streams and retention ponds. We analyzed trends in microplastic counts across different land-cover classes, waterbody types, and species, and compared concentrations among matrices to improve our understanding of microplastic exposure pathways in freshwater ecosystems. As a secondary objective, lead and arsenic concentrations were analyzed from sediment samples to investigate metal burdens and compare them to microplastic concentrations. Our findings revealed that, in general, urban streams had the highest microplastic concentrations within land cover categories, and retention ponds had higher microplastic counts than streams. Crayfish, such as F. rusticus had higher microplastic concentrations than F. virilis and F. propinquus, although these results may be influenced by study design. The most common microplastic type was fibers, and most common color was transparent. There was no significant correlation between microplastic and metal concentrations in sediments. We found crayfish to be adequate bioindicators of microplastic pollution, because they were less impacted by environmental variability than sediment and water samples. This research presents the first evidence of microplastics in our study species, F. propinquus, F. rusticus, and F. virlis. This work presents new evidence of microplastic accumulation in crayfish, sediments, and water from freshwater systems in the Midwestern United States. Microplastics were found in every sample type—crayfish, water, and sediment—across urban, rural, and forested landscapes, highlighting their pervasive distribution. The findings provide foundational data for assessing emerging ecological and human-health risks and emphasize the importance of sustained monitoring and research on MP contamination in freshwater environments.

Which Energy Expenditure Equation Is Most Accurate In A Field-Based Setting?, Merrill C. Ward

All Graduate Reports and Creative Projects, Fall 2023 to Present

Several energy expenditure prediction equations for walking on varied terrain exist; however, these predictions are often theoretical and have not undergone rigorous field testing for accuracy. Field research on this topic is sparse. The aim of this study was to determine if any existing energy expenditure prediction equations are accurate in a field-based setting with load and gradient being taken into account (i.e., under conditions that are most applicable to day hiking). This was done by directly measuring relative VO₂ (ml/kg/min) of study participants and comparing these direct measurements to the values generated from the existing prediction equations. Fifteen …

Long Term Changes In Elk Group Size And Composition (2002-2023) In Relation To Wolf Hunting Sucess, Kennedy Price

Undergraduate Honors Capstone Projects

Elk (Cervus elaphus) in Yellowstone National Park exist within a predator-prey system shaped by long-term interactions with wolves (Canis lupus). This predator-prey system represents an important model for understanding how predation influences ungulate behavior and social organization. Predators affect prey behavior through direct and indirect interactions and may cause long-term changes. What this study strives to answer is if predator success can have long term effects on prey grouping behavior and age-sex structure. In a previous study, wolves were found to be most successful hunting medium sized group of elk (20-49 individuals) in Yellowstone National Park. …

Understanding Vaccine Hesitancy In Veterinary Medicine: A Review Of Client Attitudes, Grace Moore

Undergraduate Honors Capstone Projects

Uncertainty toward vaccination, long recognized as a public health concern in human medicine, is increasingly recognized within veterinary contexts, posing risks to both animal and community health. This literature review examines the development, causes, and implications of reduced vaccine confidence in veterinary medicine, with emphasis on small animal and some large animal practices. The review combines historical and current research to explore how vaccination perceptions have evolved among veterinarians and clients, and how factors such as the COVID-19 pandemic have shaped current attitudes.

The literature highlights recurring themes surrounding vaccine reluctance in veterinary settings. Client perceptions of safety, efficacy, and …

Influence Of Induced Brumation On Health And Stress Indicators In Captive Thamnophis Elegans, Preston Papa

Undergraduate Honors Capstone Projects

Reptiles that live in temperate environments undergo prolonged periods of inactivity and reduced metabolism called brumation to survive seasonal periods of cold. Garter snakes (Thamnophis spp.) are known for congregations during seasonal brumation and are often held in captivity for research or as pets. Additionally, changing climate has influenced the brumation period of temperate reptiles including garter snakes all across North America. Understanding how natural populations may respond to changing environmental conditions such as shorter winters is important for conservation of the ecosystem. This study examined the health implications of artificially inducing brumation in garter snakes (Thamnophis …

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 …

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 …

Effects Of Tourist Feeding On The Gut Microbiome And Ecophysiology Of Endangered Northern Bahamian Rock Iguana (Cyclura Cychlura), Erin Lucy Lewis

All Graduate Theses and Dissertations, Fall 2023 to Present

The lifespan and reproduction of an animal depends on maintaining a healthy physiology. The proportion of individuals that survive to an age at which procreation can occur is important to long-term stability of populations and contributes to species survival. Health in an animal is measured in a variety of ways, including through monitoring of the body’s physiological systems, as well as its ability to respond to invading pathogens, and through the different types of bacteria present in the gut. Relationships among those different health metrics have been discovered in recent years and have been found to play important roles in …

Impact Of Inhibiting Mitochondrial Calcium Uptake On Calcium Homeostasis And Postmortem Metabolism In Porcine Muscle, Fatema Rahaman Mishu

All Graduate Theses and Dissertations, Fall 2023 to Present

After harvesting the animal, pork muscle continues to undergo changes as it turns from muscle into meat. During this early period, the muscle uses up energy and produces acid, which lowers pH and can affect important quality traits such as color and how well the meat holds water. A key driver of these early changes is calcium, a natural mineral inside muscle cells that helps control contraction and energy use. In this study, we tested whether mitochondria (the cell’s “powerhouse”) help control calcium after harvest and, in turn, influence early postmortem changes in pork. We used a research compound (DS16570511) …