Life Sciences Commons^™

Are Sticky Prices Present In Us Ag Land Lease Rates, John Tyler Blazzard

Graduate Theses and Dissertations

Land is an essential resource in production agriculture. Limited supply and high demand for land have resulted in increasing land values which are a barrier to entry for beginning farmers and ranchers with limited access to capital and credit. One way to overcome the high costs of purchasing land is to lease it. While more affordable than purchasing land, cash rents are also increasing. The objective of this research is to determine whether agricultural cash rents follow farm income symmetrically over time. This is accomplished by implementing Ordinary Least Squares (OLS) regressions with two-way fixed effects which account for rental …

A Series Of Investigations On The L. Cornutus Host System And Bivesiculid Sp. Cercariae, Briana K. Zaffiro

All HCAS Student Capstones, Theses, and Dissertations

Rising global temperatures are likely modulating parasite-host interactions, yet the direction and magnitude of these changes remain uncertain. Rarely are these interactions viewed from both a host and parasite perspective. Using both CT_max, or Critical Thermal Maximum, and Clark-type polarographic oxygen microelectrodes, the physiological metabolic effects are investigated. CT_max is examined in Common Shiners, Luxilis cornutus, and is shown to be modulated by parasitism: uninfected fish had the highest CT_max average of 37.0°C, whereas heavily infected fish had decreased CT_max averaging 35°C. Prior to the parasite metabolic investigation, a suitable medium was determined, as …

Geospatial Science And The Changing Environment: Applied Methods For Sustainable Agriculture And Landscape Management, Harrison Wakefield Smith

Graduate Theses and Dissertations

Rapid environmental change is disrupting agricultural productivity, ecological function, and the long-term resilience of managed landscapes. At the same time, the rapid growth of geospatial data science has improved our understanding of environmental change and increasingly is being used to improve sustainability in agricultural and environmental management. However, critical gaps remain that limit the applicability of data-driven insights in landscape management. This dissertation investigates the potential of geospatial analytics for sustainable agriculture and landscape management, with a focus on applied methods that operate across spatial and temporal scales. Using field, landscape, regional, and national datasets, it explores the capabilities and …

Genome-Wide Phenotypic Characterization Of Mycobacteriophage Mercurio, Tyler Downs

Departmental Honors & Graduate Capstone Projects

Bacteriophages, or phages, are being piloted as a supplemental or alternative therapeutic to antibiotics against drug-resistant Mycobacterium pathogens, such as M. tuberculosis, which pose a global public health crisis.  Characterizing bacteriophage genomes can provide insights into efficacy in phage therapy before implementation or elucidate new targets to manipulate bacterial growth.  Overexpression of individual phage genes is useful to study a gene product’s function independent of others.  Here, the results of phage Mercurio plasmid library overexpression in plate-based assays are described.  Mercurio infects nonpathogenic Mycobacterium smegmatis and is genetically related to bacteriophages infecting pathogenic Mycobacterium species.  Eleven gene products of …

Aggregation And Collation Of Texas Crayfish Museum Specimens To Determine Their Current Conservation Statuses, Adrian Alvarez

Biology Theses

Crayfish account for over half of the macroinvertebrate biomass in many ecosystems and serve as crucial bioindicators because of their behavioral and physiological adaptability to environmental changes. Despite being home to approximately 52 native crayfish species, Texas currently lacks protective regulations. This gap is primarily because of insufficient information regarding their distribution and occurrences within the state, including their statuses as Species of Greatest Conservation Need (SGCN). This study focuses on compiling and comparing crayfish museum records with current iNaturalist field survey data across Texas to address these knowledge gaps and recommend updates to SGCN statuses. Five species not currently …

Quantitative Genetics, Genomics, And Phenomics In Maize And Sorghum, Nikee Shrestha

Complex Biosystems Program: Dissertations and Student Research

Generating the best crop varieties and hybrids requires identifying genes associated with the phenotype of interest and screening thousands of varieties across multiple locations. Quantitative genetics, along with comparative genomics, phenomics, and machine learning approaches, can help us identify target genes associated with the phenotype of interest to develop the right genotypes. Satellite platforms offer logistical and technical advantages in scalability and accessibility and could facilitate plot-level predictions, especially with steadily improving spatial resolution, thereby empowering the large-scale screening of thousands of genotypes across diverse locations. In the first chapter, I evaluated over 20,000 plot-level images of over 80 hybrid …

The Effect Of Including A Yeast Culture Containing Essential Oils In Receiving Cattle Diets On Growth Performance And Health, Taylor Deanna Foster

Animal Science Undergraduate Honors Theses

Due to the increased risk of bacterial populations developing resistance to current antibiotics, consumer perceptions surrounding the utilization of antibiotics use in cattle, and the endemic incidence of bovine respiratory disease (BRD) among growing and finishing cattle, alternative management strategies to improve the health of cattle must be developed. The objective of this study was to evaluate the use of a supplement containing a yeast culture and an essential oils blend (YEO) on the health and growth performance of stocker calves at high-risk for BRD. Crossbred male beef calves (n = 185) received on two separate dates were used in …

Influence Of Increased Supplementation Of Organic-Complexed Zinc To Beef Cows During Gestation: Effects On Preweaning Health Of Offspring, Naija N. Sharpley

Animal Science Undergraduate Honors Theses

The objective of this study was to determine the effect of increasing zinc supplementation from organic-complexed sources to beef cows during gestation on calf performance. In May 2025, during gestation, Angus crossbred cows were confirmed pregnant with female sexed semen (n = 83) and enrolled in the current study. Cows (4.7 ± 2 years of age and 531 ± 84.4 kg body weight, mean ± standard deviation) were allotted to 4 groups (20 to 21 cows/group) based on, sire of heifer calf, cow age, and cow body weights taken at weaning. Assigned groups received 1 of 2 treatments (2 groups/treatment): …

Identifying The Role Of Human Dna Polymerase Delta During Human Cytomegalovirus Genome Synthesis, Rachel Laree Dansereau

Dartmouth College Master’s Theses

Human cytomegalovirus (HCMV) is a large double stranded DNA virus and member of the Herpesviridae family. Like all herpesviruses, HCMV presents with characteristics of persistent, lifelong infections that transition between lytic and latent states. The replication of the viral genome is traditionally thought to occur by a rolling circle mechanism, but this model is supported by little evidence. It is known that HCMV actively recruits several host proteins to viral replication compartments (RCs), including proteins involved in the DNA damage response (DDR). The exact mechanisms of how these proteins are used and in what ways they help the virus remain …

Using The Flexon Approach To Rnai For Analysis Of Gene Function In Gonadal Development In C. Elegans, Andrew D. Spalding

Undergraduate Theses

C. elegans, a nematode worm, was used as a model organism to analyze the developmental effects of knocking down the expression of genes that are both essential to worm viability and highly enriched in reproductive tissues. In earlier research, approximately 70 C. elegans genes were identified that are both gonad-enriched and essential. To prioritize which genes should be the focus of future studies, a new strain of C. elegans was produced with three specific genetic variations that: 1) silence essential, somatic gonad-enriched gene expression, 2) limit the effects of this gene silencing to the gonad, and 3) yield a …

Expanding Access To Noninvasive Spinal Neuromodulation For Pediatric Spinal Cord Injury Rehabilitation: A Comparative Device Study, Alice E C Palmer

College of Arts & Sciences Senior Theses

Paralysis following spinal cord injury (SCI) has traditionally been considered permanent due to the disruption of supraspinal input to spinal motor circuits. However, growing evidence suggests that spinal networks below the level of injury retain intrinsic motor-generating capabilities through central pattern generators. Transcutaneous spinal cord stimulation (scTS) is a noninvasive neuromodulation technique that delivers electrical stimulation through the skin to reactivate these spinal networks. Although prior studies demonstrate that scTS delivered through research-grade devices is safe and effective in adults and children with chronic SCI, clinical translation remains limited by lack of FDA-approved systems, high costs, and restricted access to …

Using A Toxic Aging Coin To Assess Hexavalent Chromium Neurotoxicity: Impact Of Cr(Vi) On The Blood-Brain Barrier, Liam Buchanan

College of Arts & Sciences Senior Theses

The US population faces simultaneous public health threats from both aging and environmental pollutants. Chief among these is hexavalent chromium [Cr(VI)], whose toxic effects in peripheral tissues are well-established but its effects on the brain are still understudied. Following previous results indicating hippocampal metals dyshomeostasis after Cr(VI) exposure, we aim to assess Cr(VI)’s impact on the blood-brain barrier (BBB), a key structure for brain protection. We exposed young, middle-aged, and geriatric rats of both sexes to low levels of Cr(VI) in their drinking water for 90 days, after which we used immunofluorescence and confocal microscopy to analyze tissues for evidence …

Cholesterol Effect On The P-Glycoprotein Conformational Dynamics, Zane Bunn

Biological Sciences Undergraduate Honors Theses

P-Glycoprotein (Pgp) is a human efflux pump that belongs to the ABC transporter family. This protein consists of two transmembrane domains (TMD) that convert between inward to outward facing configurations to remove a wide variety of structurally different compounds from the intracellular membrane into the extracellular space using ATP.  This non-specific efflux of compounds has brought Pgp to scientific light as having a major role in multi-drug resistance of many diseases, and researchers are focused on developing a deeper understanding of the protein. To further this understanding, this study analyzed how the structure of Pgp is affected by a 10% …

Hormonal, Cytokinetic, And Skeletal Response To A Single Weighted Vest Exercise Treatment: A Pilot Study To Determine Weighted Vest “Rucking” Treatment For Osteoporosis In Post-Menopausal Women, Eleanor Pell

Master's Theses

Osteoporosis is characterized by a deteriorating of bone tissue leading to brittleness and increased fracture risk that affects both men and women as they age. Postmenopausal women are of particular interest due to high risk of declining bone density, a characteristic of this population. Treatments for osteoporosis range from menopause hormone therapy, bisphosphonates, biologics, nutritional changes, and exercise. Load bearing exercise interventions have shown effectiveness for stimulating bone growth, but many factors such as lack of access, motivation, self-confidence or knowledge, prevent long term compliance. “Weighted vest rucking” refers to a variation of rucking, which is a form of exercise …

Companion Parrot Vocal Learning And Reproduction Of Human Speech Sounds, Karla Vilches Castaño

Master's Theses

Vocal learning is rare among animals but is well developed in parrots, which can imitate novel sounds and, in captive settings, reproduce human speech. This study helps address a larger evolutionary question about vocal learning. Specifically, whether vocal learning ability is best understood as a single generalized trait or as a multi-dimensional system in which different acoustic features can be learned and reproduced with varying degrees of fidelity. This thesis quantifies how closely companion parrots match their human tutors across three acoustic dimensions (spectrographic structure, intensity contour, and pitch contour) and tests whether mimicry accuracy varies among individuals, differs between …

Investigating The Taxonomic Uncertainties Of Potentilla Rupincola, Natalie Elizabeth Hieber

Master's Theses

Landscape stewardship is an integral role for land managers that becomes more important when rare or endangered species occur within managed areas. Conservation across the landscape is a primary concern for land managers, but resources allocated for conservation can be limited due to many competing goals. Taxonomic uncertainty surrounding rare and endangered taxa, particularly plant taxa, that have historically been classified solely using morphological features further complicates conservation planning. One such taxon is Potentilla rupincola, a rare plant endemic to the eastern Rocky Mountains in Colorado. For over a century, botanists have debated whether P. rupincola is a distinct species …

The Effects Of Impervious Land Cover And Red Tide (Karenia Brevis) On The Florida Manatee (Trichechus Manatus Latirostris) In The Gulf Coast Of Florida, Anna Compton

Honors College Theses

Red tide, caused by the dinoflagellate Karenia brevis, is an algal bloom event that occurs annually in the West Florida Continental Shelf. The algae releases brevetoxin, a toxin that can be fatal to wildlife in high concentrations. These algal bloom events are thought to be exacerbated by warming ocean temperatures and increased nutrient runoff from urbanization. Red tide is responsible for the mass mortality of various marine organisms like the Florida manatee (Trichechus manatus latirostris). This study analyzes the changes in nutrient runoff and sea surface temperatures, and how these factors affected red tide cell concentrations and Florida manatee mortalities …

2026 Workshop On Bridging The Gaps: Tackling Microplastics And Nanoplastics Challenges In Coastal Ecosystems, Shenghua Wu, Kaushik Venkiteshwaran, Melike Dizbay-Onat, Alexandra Stenson, Jinhui Wang, Tina Miller-Way, Ebenezer Nyadjro, Bhuvnesh Bharti, John Weinstein, Yi Bao, Shihui Shen, Valerie Longa, Shenghua Zha, John Cleary, Marty Lind

Workshops

This report presents the findings from the 2026 Workshop on Tackling Microplastics and Nanoplastics (MNPs) in Coastal Ecosystems, which took place in Mobile, Alabama. More than 140 experts from universities, government, industry, and community organizations gathered to address the increasing issue of MNPs in coastal regions.

Sorghum Grain Secondary Metabolites And Underlying Genetics To Reduce Foodborne Pathogens In Poultry, Maria A. Conti

All Dissertations

The rise in antibiotic-resistant pathogens poses a threat to the poultry industry's ability to maintain animal health, prompting growing interest in alternatives to synthetic antibiotics. The use of non-tannin sorghum [Sorghum bicolor (L.) Moench] in poultry rations offers a valuable alternative, as this cereal grain has a high bioactive profile that can provide health benefits, including antimicrobial (AM) activity. The scope of this study was to examine the AM potential of non-tannin sorghum grain against Clostridium perfringens, a major foodborne pathogen that negatively impacts poultry health and production. To that end, the inhibitory effects of a non-tannin sorghum …

Developing Warning Signage For Harmful Algal Blooms At Lake Fayetteville, Abigail R. Evans

Biological Sciences Undergraduate Honors Theses

The presence of harmful algal blooms (HABs) poses many risk factors for human health, and once microcystin concentration has reached a certain level, that water source will be closed for the duration of the bloom. Agencies tend to use static signage with limited information to inform the public about the current status of the water, but a sign similar to the one used by the National Fire Danger Rating System can allow for constant updates detailing specific risk levels for the public. Using previously reported data on Lake Fayetteville, thresholds for risk factors that are easily measurable were determined. The …

The Genetic Basis Of High Transformation Efficiency In The Model Yeast Saccharomyces Cerevisiae, Mary Kathryn E. Cheek

Biological Sciences Undergraduate Honors Theses

Transformation, a type of horizontal gene transfer, describes the uptake, maintenance, and integration of environmental DNA by cells. Despite the known effects of transformation on evolutionary processes, little is known about the genetic basis of this phenomenon. Saccharomyces cerevisiae is a eukaryote able to transform at quantifiable rates when made chemically competent and treated with a heat shock. S. cerevisiae also has variation in transformation efficiencies between various strains, and high recombination rates allow for sufficient allele “shuffling” in intercross populations. This project utilizes a bulk segregant analysis approach to compare sequencing data between transformant pools and non-transformant pools of …

Exploring Exercise Motivation And Mental Well-Being In College Students, Elaine M. Lindesmith, Anqi Deng Dr

Health, Human Performance and Recreation Undergraduate Honors Theses

This study examined the relationship between physical activity, exercise motivation, and mental well-being among 48 undergraduate students at the University of Arkansas. Guided by Self-Determination Theory, the study used survey data to measure depression, anxiety, physical activity, and open-ended exercise motivation responses. Motivation responses were coded as autonomous or controlled.

Results showed that physical activity was weakly and negatively related to depression and anxiety, but these relationships were not statistically significant. There were also no significant differences in mental health between autonomous and controlled motivation groups, and motivation did not significantly predict mental health outcomes in regression analyses. Overall, the …

Dried Water Treatment Residuals Might Be An Option To Reduce Soluble Reactive Phosphorus Release From Soils, Katie B. Mckay

Biological and Agricultural Engineering Undergraduate Honors Theses

Nonpoint source pollution from agricultural landscapes contributes to freshwater eutrophication, with legacy phosphorus (P) in soils potentially driving soluble reactive phosphorus (SRP) losses to surface waters. The objectives of this study were to evaluate SRP adsorption by dried water treatment residuals (WTRs) produced by Beaver Water District, quantify reductions in soil SRP release across increasing WTR application rates, and compare dried WTR performance to prior WTR studies.

Dried WTRs (~98% solids) were assessed using batch sorption experiments and soil core incubations. Phosphorus sorption was measured by mixing WTRs with CaCl₂ solutions containing increasing SRP concentrations and fitting results to …

Cross-Facility Reliable Deep Learning Based Beef Marbling Assessment Via Unsupervised Domain Adaptation Regression, Samuel Vinson

Biological and Agricultural Engineering Undergraduate Honors Theses

Inconsistent quality grading in beef production leads to inefficiencies, economic disparity, and consumer mistrust. While USDA meat grading traditionally relies on skilled visual inspectors, these human evaluations suffer from cross-facility variability and subjectivity. This paper introduces the first known application of unsupervised domain adaptation regression for cross-facility beef marbling score prediction—an innovation that improves generalization across diverse environments in the beef supply chain. Utilizing numerical scores ranging from 100-900, the research employed convolutional neural networks (CNNs), including ResNet, VGG, and AlexNet architectures. The study specifically introduced and validated a unified unsupervised domain adaptation regression method using the ResNet-50 architecture to …

Preserving The Past: Exploring The Last Frontier's Ecosystem Shifts And Biodiversity Of The Tallgrass Prairies, Gisell Maldonado, Amelia Villaseñor

Anthropology Undergraduate Honors Theses

In North America, grasslands are a cornerstone of the environment. Historically, the tallgrass prairie was expansive and reached from Manitoba in Canada to Texas. Today this unique ecosystem is highly fragmented and reduced, but it remains an important ecosystem for biodiversity and cattle management. While there are many complex ecological interactions in the prairie, recent research shows that large herbivores are vital in maintaining grasslands through grazing and other behaviors that reduce woody encroachment and support nutrient cycling. Here, we examine cow and bison dietary behaviors and connect these to the ecosystem services provided by these large herbivores. In the …

Historical Comparison Of Bridal Fashion Symbolism: Contrasting Queen Elizabeth Ii, Princess Diana, And Catherine, Princess Of Wales, Rebecca O'Dea

Apparel Merchandising and Product Development Undergraduate Honors Theses

The purpose of this study was to gain understanding and insight into the profoundness behind the practice of dress. Throughout history, royal attire has been used to demonstrate aspects about the individual and regency. Royal fashion served as an excellent area to narrow in on, due to the influential status, and high standards expected of their appearance and actions. This research project studied members of British royal family, Queen Elizabeth II, Princess Diana, and Catherine, Princess of Wales, and analyzed fashion elements of their wedding dresses. The examination of bridal fashion was conducted through thematic framework determining if the concepts …

Fisheries Management Paper No. 313: Western Australian Statewide Small Pelagic Scalefish Resource Harvest Strategy, Department Of Primary Industries And Regional Development, Western Australia

Fisheries Management Papers

Harvest strategies for Western Australia’s (WA) aquatic resources are formal documents developed by the Department of Primary Industries and Regional Development (DPIRD, the Department) to support decision-making processes that ensure the outcomes are consistent with the principles of Ecologically Sustainable Development (ESD; Fletcher 2002a) and Ecosystem Based Fisheries Management (EBFM; Fletcher et al. 2012).

Harvest strategies are a key component of all contemporary fishery management systems and a requirement for certification under the Marine Stewardship Council (MSC; Marine Stewardship Council 2018). The objectives of ESD are reflected in the objects of the Fish Resources Management Act 1994 (FRMA).

This Statewide …

Three Essays On Veterinary Drug Maximum Residue Limits, Akinbode Okunola

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This dissertation consists of three essays: the first examines the prevalence of veterinary drug maximum residue limits (MRLs), the regulatory behavior of countries in setting these MRLs, and the degree of country-level compliance with international standards of Codex Alimentarius (Codex). The second evaluates the extent to which compliance with international standards across countries can help to manage potential transmission of resistant bacterial from animals to humans through consumption of contaminated meat, dairy and aquaculture products. The third focuses on how differences in regulatory standards across countries can impact international trade in the global beef, pork, and poultry markets.

The first …

The Undergraduate Education And Scientific Literacy: Exploring How College Influences Student Perception Of Covid-19 Events, Peyton Brooking

Theses/Capstones/Creative Projects

Current undergraduate students received much of their education following the events of the COVID-19 pandemic. Many of these students experienced pandemic events before receiving any or most of their science-based higher education. Exploring their progress through higher education, and how it retroactively influenced their perception of pandemic events, serves as an informative research area. This study explores how undergraduate education in the sciences influences student engagement with complex recent events in science. In addition, this study asked how higher education builds confidence in interpreting this information. Additionally, students were surveyed to understand their scientific literacy baseline at the beginning of …

Analysis Of The Effects Of Astaxanthin On Human Colorectal Cancer Cells, Kara A. Walters

Theses/Capstones/Creative Projects

Astaxanthin (AXT) is an antioxidant carotenoid that is produced by the microalgae Haemococcus pluvialis. This supplement is best known for its potential health benefits including anti-inflammatory, antitumor, immunomodulatory, anticancer and antidiabetic activities. Astaxanthin is marketed as an oral dietary supplement and is widely used in the nutraceutical industry as well as a coloring agent in the food industry. Since Astaxanthin has been increasingly popular as a dietary supplement, cytotoxicity is relevant to consumer exposure. Obtaining the IC50, the concentration that inhibits 50% of cell growth, is important to find how Astaxanthin may interact with cancer, and this can be found …