Life Sciences Commons^™

Cytokinins, Gibberellins, And Ethylene On Plant Form And Flowering In Streptocarpus, Rachel Bobo

Theses and Dissertations

Plant form and flowering of Streptocarpus x hybridus Ladyslippers® ‘Grape Ice’ and ‘Deep Blue Vein’ were examined in response to exogenous application of ethephon [(2-chloroethyl) phosphonic acid], gibberellin 3 (GA3), benzyladenine (BA), and growth retardants ancymidol and chlormequat chloride. 750 mg L-1 ethephon applied at 3 weeks post-transplant (WPT) is effective in chemically pinching premature floral buds, delaying flowering by up to 10 days without restricting final plant size. Early applications of GA3 and BA hasten flowering by up to 10 days. GA3 and BA also interacted to promote floral development when applied early in the production cycle; increasing flower …

Determining Agricultural Literacy Proficiency Of Extension Professionals And Primary Volunteers In Mississippi, Molly Campbell

Theses and Dissertations

The development of agricultural literacy is a lifelong process, moving from gaining agricultural knowledge to communicating with others to applying to societal issues, and extends beyond the formal classroom. The Mississippi State University Extension Service has the ability to reach various audiences through educational programming, making them a potential catalyst for change in increasing agricultural literacy across the state. The study aims to determine the agricultural literacy levels of Extension professionals and primary volunteers in Mississippi and the factors potentially influencing these levels. Twenty-nine Extension professionals and eleven primary volunteers completed a survey of demographic questions and the Judd-Murray Agricultural …

The Development And Evaluation Of An Automated Tactical Tillage Tool To Identify And Control Weeds In Row-Crop Production Systems Using Vision-Based Machine Learning., Clara Anne Cobb

Theses and Dissertations

Controlling in-field weeds in row-crop production systems is vital to the success of the operation. To control weeds, most producers use combinations of weed control strategies, including tillage and herbicide applications. Cotton production operations across the country have been trending toward conservation tillage practices in an effort to minimize soil disruption and maintain crop residues on the soil surface. This practice, in addition to the adoption of herbicide-tolerant cotton varieties, has encouraged more use of chemical herbicides. The overuse of these herbicides has resulted in an increase in herbicide-resistant weeds, making weed control difficult for farmers. This research aimed to …

Patterns Of Molecular Evolution Driving Reproductive And Genomic Processes In Sauropsids, Taylor Green

Theses and Dissertations

Sexual reproduction is an important driver of genetic diversity and speciation through such forces as selection, mutation, and drift. Sauropsids are an appropriate clade to study shared molecular drivers of sexual and genomic evolution due to their genome architecture, sex determination mechanism (SDM) plasticity, and large syntenous genomic regions. Using comparative phylogenetic methods, I identify predictable patterns of selection in meiotic recombination genes and clade-specific drivers of recombination rate evolution. Then, leveraging whole genome sequencing, I demonstrate that American alligator genomes are characterized by an ancient loss of genetic diversity driven by drift and historic inbreeding. I also generate a …

Assessment Of Energy And Hydration Demands Of Farm Workers In Mississippi, Mckenzie Lynne Hargrove

Theses and Dissertations

The agricultural community in Mississippi is critical to the state’s economy and the health of its communities. Farm workers meet these needs by performing highly demanding work with long hours of labor, limited resources, and stressful environmental conditions. The purpose of this investigation was to examine and measure indicators of physiological and behavioral adaptations to the heat such as whole body sweat rate (WBSR), sweat sodium (Na+) content, urine specific gravity (USG), and fluid intake, as well as determine total daily energy expenditure (TEE) and water influx (rH2O) via the doubly labeled water technique (DLW) in farm workers during the …

Evaluation Of Critical Nitrogen Requirements For Commercial Tomato Production In Mississippi, Prakash Khanal

Theses and Dissertations

Optimizing nitrogen (N) management is critical for tomato production, as crop requirements vary with soil, climate, and production practices. Despite the importance of tomato in Mississippi, region-specific N recommendations remain limited. Field studies (2024-2025) and a high tunnel study (2025) were conducted at the North Mississippi Research and Extension Center to determine critical N rates for fresh-market tomato. Six N rates were evaluated using a randomized complete block design with four replications. Results provide system-specific guidance, highlighting differences in N requirements between open-field and high tunnel production. Tailoring N inputs to production environments can improve yield and fruit quality, enhance …

Reproductive Genetics Of Caenorhabditis Nematodes, Dharani U. Matharage

Theses and Dissertations

Variation in reproductive traits and genome evolution reflects the interaction between selection, environment, and life-history. In the genus Caenorhabditis, recombination rate and sperm size exhibit a striking variation between strains and species. Here, Iintegrate three projects investigating recombination rate variation and recombination plasticity in C. elegans and sperm size divergence across Caenorhabditis species. First, I quantify recombination rates in two genetically distinct strains, N2 and CB4856, with different levels of laboratory adaptation using fluorescent markers spanning across gene-rich and gene-poor regions of the chromosome IV. I identify significant differences in recombination rate between the two strains within both gene-rich and …

Characterizing The Microbial Structure And Function In Black Soldier Fly Digested Dairy Manure And Subsequent Larvae, Branden N. Pierce

Theses and Dissertations

This work examined the microbial structure and gene expression found in Black Soldier Fly larval guts and their frass when reared on dairy cattle manure that had been amended with either R. rhodococcus 21198, P. polymyxa 8158, or both and compare the results to larvae reared on untreated manure. First an overview of literature surrounding projected global food supplies and the possible use of insects to either increase them or mitigate the environmental effect of producing said supply. A cellulose degradation assay was performed to assist in determining which bacterial species to use as amendments. Characterization of the microbial communities …

No-Till Versus Conventional Tillage Cover Crop Systems Effects On Cotton In The Blackland Prairie Region Of Mississippi, Mallie West Rivenbark

Theses and Dissertations

Nitrogen (N) plays a critical role in cotton production systems. Management practices such as tillage systems and cover crops (CC) can influence nutrient cycling and availability within the soil. The present study assessed the effects of CC in a conventional tillage (CT) vs. no-tillage (NT) system on cotton yield, fiber quality and N use efficiency. Ramifications for CC and N rates on lint yield and cotton N uptake were investigated during the 2024 and 2025 growing seasons in Verona, MS. Cover crop treatments include cereal rye (Secale cereale), crimson clover (Trifolium incaranatum) and a mix of cereal rye and crimson …

Accuracy Of Parameter Estimation For A Simple Gene Regulatory Network Model Is Sensitive To Network Motif, Number Of Parameters Estimated, And Magnitude And Direction Of Regulatory Relationships, Nikki C. Chun, Kam Dahlquist

Honors Thesis

A gene regulatory network (GRN) is a set of transcription factors that regulate the expression of genes encoding other transcription factors. The dynamics of a GRN explain how gene expression changes over time. GRNmap is a MATLAB software package that uses ordinary differential equations to model dynamics of small-scale GRNs. We used the program to estimate production rates, expression thresholds, and regulatory weights for each transcription factor in three related literature-derived GRNs based on yeast cold shock microarray data previously collected in the Dahlquist Lab. We noticed large differences in estimated weight values when 1-2% of the expression values were …

Potential Innate And Adaptive Roles Played By Γδ T Cells In A Bacterial Immunization Model, Lee Anne Talbot

Seton Hall University Dissertations and Theses (ETDs)

Francisella tularensis is a highly infectious intracellular bacterium and the causative agent of tularemia, with pulmonary infection resulting in severe disease and high mortality if untreated. While protective immunity to F. tularensis has been largely attributed to CD4⁺ T cell–mediated IFN-γ responses, the contribution of γδ T cells to mucosal immunity and vaccine-induced protection remains poorly defined. The objective of this study was to characterize the role of γδ T cells during primary pulmonary infection with F. tularensis live vaccine strain (LVS) and following intranasal immunization with inactivated F. tularensis (iFt) prior to LVS challenge.

Using a murine intranasal infection …

Exploring Health Insurance’S Role In Chronic Disease Management Among Hispanics, Romelyn Dones

Seton Hall University Dissertations and Theses (ETDs)

This qualitative study examined how insured non-English- and English-speaking Hispanic adults perceive the role of health insurance in the management of chronic disease. Chronic conditions remain a leading cause of morbidity in the United States, and although prior research suggests that insurance coverage improves access to care, it does not always enhance how individuals understand or utilize support for chronic disease management. Limited research has explored how individuals with chronic conditions interpret the role of insurance in their daily self-management practices, particularly among Hispanic populations. Guided by Andersen’s Behavioral Model of Health Services Use, this study explored how contextual, enabling, …

Interpretable Deep Learning Models For Trustworthy Prediction Of Enzyme Functions, Louis Dumontet

UNLV Theses, Dissertations, Professional Papers, and Capstones

Trustworthy prediction of enzyme function from protein sequences remains a central challenge in computational biology, particularly when annotated data are limited, imbalanced, or incomplete. This dissertation develops interpretable deep learning methods for enzyme discovery and enzyme function prediction from amino acid sequences. First, it introduces PEPIC, an interpretable convolutional neural network for substrate-level prediction of hydrolytic plastic-degrading enzymes. Using curated and expanded sequence datasets, PEPIC improved predictive performance over benchmark methods, identified sequence regions aligned with catalytic and substrate-binding residues, and supported the discovery and experimental validation of a previously uncharacterized PET-degrading enzyme. Second, this dissertation investigates the integration of …

From Flight To Hatching: Adult Sexual Dimorphism, Life History, And Egg-Stage Ecology Of Pseudocotalpa Giulianii, Mandylene Mountain

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada endemic dune beetle Pseudocotalpa giulianii is currently known only from two dune systems in Amargosa Valley, Nevada, yet much of its life cycle occurs below the sand surface and remains poorly documented. This thesis addresses key gaps in adult-stage biology and egg-stage development that are relevant to understanding reproduction, vulnerability, and habitat requirements in this dunerestricted species.

To characterize adult sexual dimorphism and life history, I quantified morphological differences between males and females and measured sex-specific adult survival under laboratory conditions relative to the aboveground flight season. Males and females overlapped broadly in external body size, but tarsal …

Application Of Occupational Therapy Task-Oriented For Chronic Post-Stroke Rehabilitation: A Case Study, Gia Nghi Vu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Stroke remains the leading cause of long-term disability, with persistent upper extremity (UE) impairment limiting engagement in daily tasks, reducing quality of life and contributing to learned non-use in the chronic stage among stroke survivors. The Occupational Therapy Task Oriented (OTTO) approach is proposed to optimize occupational performance through the use of meaningful, functional and highly individualized tasks that enable clients to fulfill their valued roles and participate in desired daily activities. The purpose of this capstone project was to advance clinical skills by applying the OTTO approach to examine its effect on occupational performance and UE motor function in …

Ecological And Nutritional Drivers Of Floral Fidelity In Wild Pollinators, Adelaide Elise Ergastolo

Master's Theses

Plants must receive pollen from the same species in order to successfully reproduce. For most flowering plants, the transfer of pollen occurs via animal pollinators while they forage on plants to obtain food. Therefore, the fidelity of pollinators to individual plant species during foraging trips is directly related to the amount of conspecific pollen plants receive. Low floral fidelity of pollinators can reduce plant reproductive success, which in turn has the potential to lower food resources for pollinators in the future. While many factors can potentially influence pollinator floral fidelity, several important ones may be the nutritional resources provided by …

Community Development Professionals’ Perceptions Of Agritourism In Mississippi, Emma Jane Berry

Theses and Dissertations

Agritourism has emerged as a strategy for supporting rural economies, strengthening community identity, and increasing agricultural literacy. Although prior research has examined agritourism operators and visitors, limited attention has been given to the perceptions of community development professionals who influence local planning and program support. The purpose of this qualitative exploratory study was to examine community development professionals’ perceptions of agritourism’s role in community development, economic growth, and agricultural literacy in Mississippi. Guided by Social Exchange Theory, data were collected through two semi-structured virtual focus groups with 12 professionals representing Extension, tourism, economic development, and Main Street organizations. Data were …

From Miocene Origins To Ecological Diversification: Unraveling Evolutionary Dynamics Of North American Asters (Symphyotrichum), Sushil Dahal

Theses and Dissertations

Symphyotrichum, a plant genus traditionally treated within the genus Aster L., comprises >100 species of annual or perennial plants in the Compositae family Asteraceae. One of the most diverse genera in the southeastern US flora, the genus extends across the Americas, the Caribbean as well as eastern Eurasia. Despite its presence across the major American biomes and with distinctive floristic characteristics, several question regarding Symphyotrichum remains obscure. This research project focuses on exploring diverse aspects of Symphyotrichum systematics, biogeography and evolution. I tested three main hypotheses: (1a) Symphyotrichum originated ancestrally across Mexico and eastern North America in the Miocene ( …

Evaluating The Spray Patterns Of Boomless Spray Nozzles At Increasing Application Speeds, Thomas Hayden Duncan

Theses and Dissertations

Boomless nozzles have been largely ignored in spray studies, resulting in limited understanding of their spray patterns and how they are affected by operating parameters. A study was conducted to evaluate the effect of application speed on the performance of four boomless nozzles. Dyed water was applied to Kromekote® paper to assess spray distribution based on coverage data at three speeds, and MSMA was applied to a mixed turf stand to evaluate the effect of speed on performance. Overlap simulations were done to evaluate how uniformity could be improved, and nozzle performance was compared to manufacturer claims. Spray patterns of …

Assessing Biotic And Abiotic Drivers Of Hybridization And Species Delimitation In A Highly Reticulate Syngameon, Nicholas John Engle-Wrye

Theses and Dissertations

Hybridization, or the flow of genetic materials between varieties or species, shapes evolution by generating novel genotypes, altering allele frequencies, and driving diversification. Yet, the rate at which hybridization occurs is heterogeneous across the tree of life and the ecological and evolutionary factors that govern its occurrence remain poorly understood. This dissertation examines how conserved biotic and abiotic niches influence hybridization and uses integrative methods to delimit species boundaries within Heuchera (Saxifragaceae), a genus notable for widespread interspecific gene flow and cryptic morphological diversity. Results reveal that hybridization is most frequent where pre- and postzygotic barriers are weak, as with …

Effects Of Melatonin Supplementation On Exercise Induced Stress In Horses, Hannah Clark Valigura

Theses and Dissertations

Exercise is a necessary component of athletic conditioning but imposes substantial physiological stress on horses, resulting in oxidative stress, inflammation, muscle damage, and thermal strain that can impair performance and recovery. Melatonin, a neurohormone with potent antioxidant and thermoregulatory properties, has been proposed as a novel nutritional strategy to mitigate these effects. This dissertation aimed to (1) characterize serum melatonin concentrations following oral supplementation, (2) evaluate the effects of melatonin on oxidative stress, inflammation, and muscle damage biomarkers after exercise, and (3) examine its influence on physiological parameters during exercise under warm weather conditions. Across a series of controlled experiments …

Harnessing Mechanobiology Of Resident Stem Cells To Refine Cell Based Therapeutics, Dakota R. Kamm

WUSM Theses and Dissertations – All Programs

Mesenchymal stem cells (MSCs) are resident cells residing with many adult tissues such as adipose tissue and bone marrow that have the potency for multiple lineage differentiation as well as the capacity to secrete a litany of beneficial factors to maintain homeostasis and promote tissue repair. Since 1995, MSCs have been used therapeutically to treat a variety of conditions from osteoarthritis to heart disease to muscle pathologies. Great leaps have been made in improving MSC-based therapies through optimization of culture methods and select enrichment of cellular subpopulations. More recently, the physical microenvironment of tissue in vivo and culture conditions in …

Cortical Bone Density And Thickness Assessment Of Intraradicular Sites In Adolescent Patients Using Cbct Imaging, Sara Endo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: The indications for the use of cone beam computed tomography (CBCT) in orthodontics has grown since it was first introduced and dentists are discovering new ways that 3D images enhance diagnosis and treatment planning. Evaluating bone quality and quantity can be measured as bone density and thickness in CBCT imaging and is helpful for temporary anchorage device (TAD) placement in orthodontic treatment. TADs rely on primary stability and are commonly used in orthodontic treatment to increase anchorage and expand the limit that nonsurgical orthodontics can provide.

Objectives: This study aims to assess the bone thickness and density at different …

A Tale Of Two Mammals: Tenrec Ecaudatus And Homo Sapiens, Debra Renee Kerr

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most modern mammals maintain stable body temperatures (Tb) ~37ºC and high metabolic rates. Hibernators, like ground squirrels, are homeothermic during the active summer season, but are heterothermic during the hibernation season. During the hibernation season, ground squirrels follow a predictable pattern of torpor bouts interrupted by interbout arousals. Tenrecs are unusual because they are heterothermic and heterometabolic even during the active season. Previously, ground squirrel bile constituents were shown to be predictive of whether a squirrel is in the summer active or winter hibernation season. We found tenrec bile constituents were highly variable and not predictive of seasonal and metabolic …

Skin Of Frog And Scale Of Dragon: Nutritional Cues, Life Cycle Kinetics, And Secretome Dynamics In Batrachochytrium Dendrobatidis, Naomi C. Okada

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nearly 50% of amphibian species are at risk of extinction, making them the most threatened group of vertebrates on the planet. A major driver of these declines is the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd), which causes the fatal skin disease chytridiomycosis. Since its discovery in the late 1990s, Bd has been directly implicated in the extinction of 90 species of amphibians and the declines of hundreds more. Despite this devastating ecological impact, relatively little is known about its basic cellular biology.

Bd has a multi-stage asexual life cycle consisting of a motile and infectious zoospore, which encysts (into a …

Thermal Physiological Ecology Of The Relict Leopard Frog At Hot And Cold Springs, Robert P. Pelletier Iii

UNLV Theses, Dissertations, Professional Papers, and Capstones

The relict leopard frog (Rana onca) once ranged across drainages in southern Nevada, northwestern Arizona, and southwestern Utah. Following a decline, the species only persisted in a few geothermally influenced hot springs, which led to the perspective that hot springs were high-quality habitat. Rana onca has been under intensive, multiagency management and the species has been translocated to establish additional populations, including at cold-water sites. Three research studies are presented into the thermal physiological ecology of R. onca with the aim of informing conservation strategy. The research was focused at a thermally influenced hot spring and a cold-water spring to …

Methylation-Dependent Regulatory Pathway That Governs The Stability Of The Sox Family Proteins And Related Developmental Regulators, Keshari Gayathri Rajawasam

UNLV Theses, Dissertations, Professional Papers, and Capstones

The SRY (Sex-determining Region Y) protein is a transcription factor encoded on the Y chromosome and is the key regulator responsible for initiating male sex determination in mammals. During early embryonic development, SRY activates the genetic program that leads to testis formation by promoting the expression of downstream genes involved in male gonadal differentiation. Mutations or dysregulation of SRY can lead to disorders of sex development such as male-to-female sex conversion and hermaphroditism, highlighting its critical role in sex determination.

SRY belongs to the SOX (SRY-related HMG-box) family of transcription factors, which includes the proteins SOX1, SOX2 and SOX3. These …

Examining Demographic And Contextual Differences In Stress-Related Sport Interference Among U.S. Collegiate Sport Participants, Heather Tran

UNLV Theses, Dissertations, Professional Papers, and Capstones

Collegiate athletes experience a range of stressors that may interfere with sport performance; however less is known about how stress-related sport interference varies across demographic groups and contexts. Guided by the transactional model of stress and coping, this study examined differences in stress-related sport interference by gender, race/ethnicity, and year in school, as well as across situational contexts (training, competition, and life outside of sport). Data were drawn from a secondary dataset of 288 collegiate sport participants who completed the Sport Interference Checklist (SIC). Independent samples t-test and analyses of variance (ANOVA) were used to examined demographic differences, and a …

Effectiveness Of Cognitive Stimulation Therapy On The Quality Of Life Of Adults With Dementia: A Secondary Analysis, Evelyn Airam

UNLV Theses, Dissertations, Professional Papers, and Capstones

This secondary analysis study evaluated the effectiveness of Cognitive Stimulation Therapy (CST) on quality of life (QoL), depressive symptoms, and cognitive function in 108 community-dwelling older adults with cognitive impairments, including dementia. Outcomes involved Quality of Life (QoL) measured by the Quality of Life in Alzheimer’s Disease (QoL-AD), symptoms of depression by the Cornell Scale for Depression in Dementia (CSDD), and cognitive function using the Saint Louis University Mental Status (SLUMS). After the CST, significant improvements were observed in QoL (p = .004), depressive symptoms (p = .002), and cognitive function (p < .001), with small effect sizes. Additionally, a significant interaction between sex and dementia diagnosis status was found in predicting cognitive changes, suggesting that the relationship between dementia diagnosis and cognitive improvement differs by sex. No between-group differences were found for QoL or depression. Findings support CST as a multidimensional, non-pharmacological intervention that improves cognitive, psychological, and social outcomes. Although effects were small, consistent improvements are clinically meaningful given the progressive nature of dementia. This study extends existing literature by demonstrating CST’s effectiveness in a community-based setting and reinforces its alignment with occupational therapy’s emphasis on participation and holistic care. Results highlight the need for early intervention and expanded access to CST programs to enhance quality of life in this population.

Unknowing Sacrifices: Public Health And Radiation Illness In New Mexico And Nevada, 1940s-1960s, Beatriz Avila-Marquez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The detonation of the first atomic bomb in the early morning of July 16, 1945, in New Mexico welcomed the atomic age that forever changed the world. After that day, thousands of lives were lost due to nuclear weapons, and hundreds of thousands more continued to suffer from the effects of atomic testing. The Atomic Energy Commission, fueled by the arms race of the Cold War, chose Nevada to continue the United States’ nuclear weapons testing. Knowledge of the dangers of radiation exposure, the effects of radiation, and techniques to prevent exposure are now available in part due to the …