Life Sciences Commons^™

Disentangling Factors Contributing To Population Performance Of Zion Bighorn Sheep, Ian Montgomery

All Graduate Theses and Dissertations, Fall 2023 to Present

Bighorn sheep populations across the western United States face increasing challenges from habitat loss, disease, and predation. In Zion National Park and surrounding areas, survey-based estimates indicate that the desert bighorn sheep population declined from over 800 individuals in 2018 to fewer than 500 in 2021. Understanding what drives these population changes is critical for effective wildlife management and conservation. This research examined key factors influencing population growth and individual survival to inform strategies for recovery in this bighorn population.

First, we analyzed which vital rates contributed most to population trends by estimating survival and reproduction rates from ground and …

Antiproliferative Effects Of Salvia On Breast Cancers., Allison C. Portaro

College of Arts & Sciences Senior Theses

Breast cancer is the most common cancer diagnosed in female adults, with 2.3 million new cases worldwide in 2020. Plants have been used in traditional medicine and are a potential source of pharmaceuticals. One example is the large Lamiaceae (mint) family. The Salvia genus, commonly known as the sages, is the largest genus in Lamiaceae with almost 900 known species. Salvia lyrata (lyre-leaved sage) has a history of Native American medicinal use to treat cancers and other ailments resulting in this plant being referred to as ‘cancer weed.’ Extracts were produced from the leaves of S. lyrata, S. lyrata …

The Effects Of Prenatal Cigarette Smoke Exposure On Developmental Milestones, Megan Jacobs

College of Arts & Sciences Senior Theses

In Kentucky, a reported 12.7% of mothers smoke cigarettes during pregnancy. Nicotine readily crosses the placental and blood-brain barriers, with fetal blood concentrations reaching 15% higher than maternal levels. By stimulating and desensitizing nicotinic acetylcholine receptors in the autonomic nervous system, nicotine disrupts uteroplacental blood flow, potentially altering fetal growth and development.

To investigate the effects of prenatal cigarette smoke exposure (CSE) on developmental milestones, C57Bl6 mice were exposed to either cigarette smoke (CSE, n = 30) or filtered room air (Sham, n = 20) for 3 hours daily from two days before mating until the day before birth. Offspring …

The Impact Of Acute Beetroot Juice Supplementation On Resting Cardiovascular Responses In Young Women, Manuel Munoz Ii, Robert L. Herron

Undergraduate Research (Journal)

Research has shown that acute supplementation with dietary nitrate will increase the amount of circulating nitrate, boosting NO bioavailability via the nitrate-nitrite-NO pathway, providing enhanced vasodilation. There are limited dietary nitrate studies including young, healthy female participants. The purpose of this study was to investigate the influence of acute dietary nitrate, via beet root juice (BRJ) supplementation, on resting heart rate and blood pressure in young, healthy women. A total of 11 women (aged 18-22) performed a repeated-measures, placebo-controlled, counter-balanced, crossover design investigated the impact of dietary nitrate on the cardiovascular system’s resting measurements after one hour. All participants completed …

Mitigating Nitrogen Losses: The Role Of Enhanced Efficiency Fertilizers In Sustainable Corn Production, Dipesh Giri

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen (N) is essential for crop production, but its inefficient use often leads to environmental losses through nitrate leaching, ammonia volatilization, and nitrous oxide (N₂O) emissions. Enhanced efficiency fertilizers (EEFs), such as nitrification inhibitors (NIs) and urease inhibitors (UIs), have been developed to minimize these losses and improve nitrogen use efficiency (NUE). This research combined a multi-year field experiment and a controlled laboratory study to evaluate how dual-inhibitor fertilizers compare to conventional urea and single-inhibitor formulations in Nebraska cropping systems. The main objective was to understand how nitrogen inhibitors influence N availability, crop performance, and nitrogen losses across different environmental …

Improving Nitrogen Management And Corn Productivity Through Enhanced Efficiency Fertilizer And Cover Crop Integration In Nebraska Cropping Systems, Madhusudhan Adhikari

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Effective nitrogen (N) management is vital for sustaining corn yield and reducing environmental impacts in Nebraska cropping systems. Three field studies were conducted to evaluate the impact of 1) fertilizer type (anhydrous ammonia [AA] with nitrification inhibitor: enhanced efficiency fertilizer [EEF] or AA without EEF) and N application timing (pre-plant vs. split with side-dress UAN) on in-season soil N availability, crop response, nitrous oxide (N₂O) emissions, residual soil N and N use efficiencies (NUEs); 2) winter cover crop (CC) species and crop rotation variability on CC biomass production, N uptake, soil N dynamics, and cash crop performance in …

Extending Cover Crop Growing Window To Improve The Health Of Environmentally Sensitive Soils, Noshin Ara Tunazzina

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Sloping and sandy soils are highly susceptible to degradation. The health of these soils could be improved with cover crops (CCs). However, CC effectiveness in improving soil health mainly depends on CC biomass production, which is often low in temperate regions. The question is: how can we increase CC biomass production? Lengthening the CC growing window can be a potential strategy. This study assessed how 1) interseeded and terminated early (2-3 weeks before crop planting) CC, 2) interseeded and terminated late (at crop planting) CC, 3) drilled (after harvest) and terminated early CC, 4) drilled and terminated late CC, and …

Leveraging Natural Variation In Yeast To Understand Susceptibility Differences In Parkinson’S Disease, Julio Andres Molina Pineda

Graduate Theses and Dissertations

Parkinson’s Disease (PD) is a neurodegenerative disorder that causes countless suffering around the world. Both forms, familial and sporadic, have been associated with the misfolding and cytotoxicity of α-synuclein, an otherwise non-pathogenic protein suspected to have various roles in the normal maintenance of the central nervous system. Model organisms have emerged as great vessels to uncover the cellular and molecular mechanisms that shape α-syn biology, and great strides have been made to understand it. Yet, it is still unclear why some individuals are affected by α-syn toxicity, while others not so much. Since it’s extremely complicated to study and probe …

Identification Of New Germplasm Sources And Traits For Breeding Heat-Tolerant Soybean Varieties, Shelby Hammond

All Theses

The heat-tolerant soybean breeding is constrained by limited genetic diversity for heat tolerance, lack of efficient selection criteria, and incomplete knowledge of heat tolerance mechanisms. The objectives of this study were to characterize the heat tolerance of a soybean recombinant inbred line (RIL) population based on traits defining leaf function, pollen viability and yield, and identify genotypes and traits that can be included in breeding programs for heat tolerance. Field trials were conducted at Pendleton, SC in 2022 and 2023 to test the heat stress responses of 192 RILs [derived from DS 25-1 (heat tolerant) x DT97-4290 (heat-susceptible)], parental lines, …

Characterizing Xylella Fastidiosa Pathogen Dynamics On Diverse Small Fruit Farms, Alexandra Ratay

All Theses

Global agriculture has been threatened for over a century due to the emergence of the plant pathogenic bacteria Xylella fastidiosa (Lysobacterales: Lysobacteraceae) (Xf). Xf comprises five main subspecies and induces severe physiological symptoms in a diverse set of host plant species by limiting xylem function. Xylem-feeding insect vectors can transmit Xf to host plants, spreading disease and reducing fruit yield. Here I studied Xf prevalence on small fruit farms to determine Xf host plant and vector infective status to the Xf subspecies level. I detected Xf in 28 host plants in South Carolina containing either Xf subspecies fastidiosa …

Don’T Be A Big Baby: Phenotypic Novelty In The Facultative Paedomorph Ambystoma Talpoideum., Andrew S. Kanes

All Theses

This thesis explores the relationship between heterokairy and the skin microbiota of amphibians, specifically focusing on the facultatively paedomorphic salamander, Ambystoma talpoideum. Heterokairy refers to variations in developmental timing that generate phenotypic novelty within life stages. The first chapter investigates how reordering metamorphosis relative to sexual maturation affects the skin microbiota in this species. By sampling different life stages—larval, paedomorphic, and metamorphic—results show the emergence of novel microbial combinations, resulting from both microbial gain and loss in the heterokairic paedomorphic stage. These findings suggest that changes in microbial communities may lead to phenotypic novelty and have broader eco-evolutionary implications. …

Application Of Remote Sensing In Mapping Callery Pear Distribution And Biomass Estimation In The Southeastern United States, Kavi Raj Awasthi

All Theses

Callery pear (Pyrus calleryana Decne. Rosaceae) is a rapidly spreading invasive species in the southeast United States (US) that hampers the function of native tree species and the forest ecosystem. Native to Southeast Asia, the species has encroached on the natural and secondary vegetation habitats of the Southern US in recent years. This study attempted to 1) map the Callery pear across the southeast US and 2) model the aboveground biomass (AGB) of individual Callery pear trees.

We used Callery pear locations and winter imageries of Sentinel-2, Sentinel-1, L-band radar, and terrain imagery for mapping purposes. In addition, we …

A Review On Treatment, Prevention, And Research Of Worldwide Parasitic Disease: Toxoplasmosis, Hannah Skinner

All Theses

Toxoplasmosis is a worldwide, yet often overlooked, parasitic disease caused by the protozoan parasite, Toxoplasma gondii. The parasite is capable of infecting humans and almost all warm-blooded vertebrates. Over a million people are infected in the United States with toxoplasmosis each year. Most infections are asymptomatic but severe cases can lead to vision impairment, neurological disorders, and congenital birth defects. T. gondii is transmitted through undercooked meat, infected feline feces, or contaminated water and soil. The burden of T. gondii infection is most notable in livestock, felines, and immunocompromised humans. Despite being a widespread disease, toxoplasmosis is neglected in …

Thymosin Beta-4: A Novel Treatment For Acanthamoeba Keratitis, Victoria A. Murphey

All Theses

Acanthamoeba keratitis (AK) is a severe corneal infection caused by the free-living amoeba, Acanthamoeba. Both stages of its life cycle (trophozoite and cyst) cause infection, primarily in contact lens wearers. It is often misdiagnosed, leading to delayed treatment and poor clinical outcomes. Current treatment options for AK rely on anti-amoebic agents that are toxic to corneal epithelial cells. Further, no single drug can eliminate both forms of the amoeba. Approximately 30% of all AK infections require a corneal transplant.

Thymosin beta-4 (Tβ4) is a G-actin binding protein synthesized in almost all human cells, including corneal epithelial cells. Tβ4 exhibits …

The Effect Corrugated Fiberboard Has On The Environment In Terms Of Compostability, Plant Growth, And Per-And-Poly-Fluoroalkyl Substance Contamination, Meredith Clem

All Theses

The “Lasagna Method” is a popular and sustainably perceived technique that many gardeners use as a free and convenient method to dispose of cardboard (corrugated fiberboard) packaging while also improving their gardens. Many claim that this creates benefits for your garden, but many others have proposed their concerns, including the safety of the practice. This research analyzes the compostability of cardboard, the effect it has on plant growth and development of lettuce, and its contamination of a prominent chemical that has known negative effects on human health. The results of these studies showed that cardboard, as it is currently produced …

Evaluating The Role Of Electrostatic Forces In The Adsorption Of Perfluoroalkyl Substances To Granular Activated Carbon, Thomas A. Mccall

All Theses

In response to new drinking water regulations announced by the EPA in 2024, many municipalities will need to monitor concentrations and implement new treatments to address PFAS, a class of anthropogenic organic contaminants. A leading technology for this application is GAC adsorption due to its familiarity and availability. The adsorption of four PFAS species (PFBA, PFBS, PFOA and PFOS) to Calgon Filtrasorb400 (F400) was evaluated for a range of pH and ionic strength conditions to investigate the role of electrostatic interactions in adsorption capacity. These PFAS are all strong acids, so pH was used as a control for GAC surface …

Chromosome Evolution Model Reveals Hidden Variation In Karyotype-Driven Speciation In Ferns, Thomas Buchloh

All Theses

Because karyotype change commonly generates reproductive isolation between diverging species, rapid karyotype evolution, like that seen in plants, may increase the total rate of diversification. However, few studies have investigated this predicted relationship. Tests of this prediction have identified a positive correlation between the rate of karyotype change (specifically whole genome duplications) and diversification, but tests have been restricted to relatively small and young clades. Fortunately, novel macroevolutionary models have recently become available to investigate patterns of karyotype evolution in large phylogenies, providing new opportunity to investigate variation in karyotype driven diversification. Ferns are one of the most karyotype rich …

Assessing The Viability Of A Proposed Third-Party Reusable Foodware System: An Environmental And Economic Comparison, Margaret Milani

All Theses

The United States generates 73 million tons of plastic waste annually, with over 6% attributed to the restaurant industry. The EPA recommends that restaurants reduce their plastic waste by transitioning to reusable foodware items. Previous studies have shown that using a single reusable foodware item, such as a cup, can result in lower environmental impacts and greater economic benefits compared to single-use plastic alternatives. However, the upfront costs of purchasing reusables, commercial dishwashers, and other associated expenses remain significant barriers for restaurants, leading many to continue using single-use plastic foodware. This study aims to analyze and compare the environmental impacts …

Healthy Dietary Patterns’ Impact On Depressive Symptoms: A Meta-Analysis Of Randomized Controlled Trials, Angela Encardone

All Theses

As the search for innovative mental health treatments expands, dietary interventions have emerged as a promising approach for alleviating depressive symptoms. This thesis presents a meta-analysis of randomized controlled trials (RCTs) examining the efficacy of whole-of-diet nutritional interventions in reducing depression symptoms among adults. Grounded in Bronfenbrenner’s Bioecological Model and Engel’s Biopsychosocial Model, this study explores the intersection of biological, psychological, and social factors that influence mental health outcomes. A systematic review identified six eligible RCTs assessing the impact of healthy dietary patterns, including the Mediterranean diet and other plant-based interventions, on depression symptoms. A random-effects meta-analysis revealed a significant …

Spatiotemporal Changes In The Imperiled And Diverse Mussel Assemblage Of The Spring River In Kansas In Response To Known And Emerging Pollutants, Joshua Holloway

Electronic Theses & Dissertations

Kansas was historically home to 50 species of freshwater mussels, of which 42 remain extant. The Spring River of southeastern Kansas is home to 34 of the remaining 42 mussels, many of which are imperiled. Elevated metal concentrations that resulted from past lead and zinc mining in the Tri-State Mining District historically imperiled Spring River mussels, but this threat has abated over the last 20 years. Ammonia pollution may have replaced the threat of metals, however, with potentially severe consequences for Spring River mussels. Our objectives were to evaluate contemporary mussel assemblage structure, in addition to spatiotemporal trends in the …

The Effect Of Implementing A Development Program Using Mental Imagery On The Time To Master Psychomotor Skills, Randal Agee

Dissertations

Psychomotor skills development programs that use mental imagery have been demonstrated to help individuals acquire psychomotor skills (Anu et al., 2020; Seymore-Walsh et al., 2020; Toth et al., 2020). The commercial trucking industry is presently experiencing a global shortage of qualified truck drivers (American Trucking Association, 2019; Staats et al., 2017). One reason individuals are avoiding or leaving careers as commercial truck drivers is the time spent away from home (Staats et al., 2017). A couple logistical strategies have been developed to improve the situation (Mittal et al., 2018; Prime Inc, 2024); however, for the solutions to be sustainable, the …

Unraveling The Antiviral Mechanisms Of Bat Cells: Processing Of Genomic Rnas By Dicer In Bat Cells Limits Sars-Cov-2 Replication, Iyanuoluwani Owolabi

Dissertations

Bats are reservoirs for numerous viruses that cause serious diseases in other animals and humans. Several mechanisms are proposed to contribute to the tolerance of bats to these pathogens. This study investigates the response of bat cells to double-stranded RNA generated by SARS-CoV-2 replication. Here, we found the involvement of Dicer in the processing of viral genomic RNAs during SARS-CoV-2 infection. Examining RNA sequencing of infected cells, small-interfering RNA (siRNA)-like fragments were found derived from viral RNAs. Depletion of Dicer showed a reduction in these RNAs and an increase in viral loads suggesting unlike other mammals, bats may use Dicer …

Determining The Influence Of A Low-Head Dam On Macroinvertebrate Communities In The Bouie River, Natalie Santiago

Honors Theses

The Bouie River is a tributary of the Leaf River and belongs to the Pascagoula River watershed, the latter of which has no flow impediments in the form of sills or dams. The Bouie River has been heavily altered in the lower 10 river kilometers (rkm) from aggregate mining (creating a series of deep gravel pits) and the presence of an earthen and concrete low-head dam (sill) located 6 rkm from the mouth of the river. However, despite these alterations, the immediate stretch of river below the low-head dam is a known spawning habitat for diadromous fish species, including the …

Examining The Molecular Mechanisms Of Glucagon-Like Peptide-1 Receptor Agonists In Cancer Cell Biology, Oliver G. Sabet

Honors Scholar Theses

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are synthetic analogs of glucagon-like peptide-1 (GLP-1) used to treat obesity and diabetes by reducing blood glucose levels and appetite. While early rodent studies suggested a link between GLP-1RAs and thyroid cancer pathogenesis, evidence in humans remains inconclusive, with randomized controlled trials not supporting that link. Due to the rapid, widespread use of these drugs, concerns have expanded to other obesity-associated cancers, with conflicting findings on their role in cancer progression. With this contradictory evidence in a novel intersection of obesity medicine and oncology, this literature review aims to summarize current understandings between GLP-1-RAs and …

The Role Of Myosin L In The Survival Of Toxoplasma Gondii And The Importance Of Mlc1 For In Vitro And In Vivo Myosin F Motility, Victoria K. Yi

Honors Scholar Theses

My thesis discusses the work that I have conducted on two myosins in Toxoplasma gondii, which is an obligate intracellular parasite that has chronically infected around 10% of the American population. It causes toxoplasmosis and severe health consequences for individuals with compromised immune systems or when infections occur in utero. However, immunocompetent individuals are asymptomatic or present with subclinical symptoms. In the Heaslip lab, I investigated two myosins in the parasite: Myosin L and Myosin F. MyoL is an uncharacterized motor that localizes at the apical end of the parasite. It was shown to be important for parasite …

Effects Of Cholesterol Concentration On Liposome And Proteoliposome Behavior, Ehsaneh Khodadadi

Graduate Theses and Dissertations

Cholesterol is crucial in modulating the behavior and characteristics of biological membranes, liposomes, and proteoliposomes, for instance in drug delivery applications. Cholesterol regulates membrane stability by influencing lipid density, phase separation, and protein-membrane interactions. In planar bilayers, cholesterol enhances membrane thickness, reduces permeability, and promotes lipid ordering, adding rigidity and fluidity. Cholesterol also modulates membrane curvature in curved bilayers and vesicles, stabilizing low-curvature regions. In this work, all-atom molecular dynamics (MD) simulations were employed to examine how varying cholesterol concentrations influence the structure and dynamics of membranes, focusing on planar and curved geometries. Bilayers with cholesterol molar ratios of 0%, …

Crispy Not Risky: Effects Of Environmental Conditions On Low-Moisture Food Persistent Bacterial Pathogens, Manita Adhikari

Graduate Theses and Dissertations

Low-moisture foods (LMFs) were not historically seen as safety risks due to their ability to inhibit pathogen growth, but evidence shows pathogens can survive in LMFs long-term, causing outbreaks and recalls. Previous studies have lacked the ability to replicate real-world contamination scenarios in LMF processing environments. This research aimed to develop inoculation methods to form LMF persistent bacterial populations (LMF PBPs) and assess pathogen responses to environmental factors, culturing methods (broth vs. lawn), and matrix type and ratio. Inoculation methods tested were “direct” (combining bacterial culture and powder on a stainless-steel coupon) and “slurry” (premixing culture and powder). Matrices included …

Polyphenol-Protein Interactions In Pigmented Cereals – A Clean-Label Approach To Tailor Starch Viscosity, Annegret Jannasch

Graduate Theses and Dissertations

Viscosity plays an important role in the food industry as it affects the quality, processing stability, and shelf-life of food and impacts physiological responses such as satiation and satiety. Greater viscosity reduces food intake by increasing the perception of satiety, primarily by delaying gastric emptying and increasing tactile stimulation. Starch is commonly added to food products as a viscosifying ingredient, which often involves chemically modifying the starch via cross-linking, to enhance its resistance to high shear, temperature and acidity. However, chemically modified starches are not “clean-label” ingredients due to the use of toxic chemicals. Therefore, further exploration is needed to …

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 …

Impacts Of Toxic Fescue Seed Consumed By Pregnant Heifers On Maternal Blood Flow And Offspring Growth Parameters: Potential For Melatonin As A Therapeutic To Improve Offspring Growth, Rachel Scott

Graduate Theses and Dissertations

The southeastern United States is home to endophyte-infected (E+), toxic, tall fescue grass. Consumption of E+ fescue by livestock has been linked to fescue toxicosis, a disease reported to cost the United States beef industry around $1 billion in annual losses. The primary objective of this dissertation was to evaluate the influence of pregnant cattle consuming E+ seed during gestation on uterine artery blood flow and growth performance of female offspring. The secondary objective was to investigate melatonin supplementation as a mitigation strategy for expected fescue-associated decreases in uterine artery blood flow and offspring growth performance. The study reported in …