Life Sciences Commons^™

Effects Of Environmental Stress And Antimicrobials On The Health, Microbiome, And Product Shelf-Life Of Channel And Hybrid Catfish, Guyue Tang

Theses and Dissertations

Two studies investigated various aspects of channel and hybrid catfish production and processing. The first study examined the effects of ammonia stress (15 mg/L vs. 1 mg/L control) on growth performance and fillet quality. While channel catfish demonstrated superior growth, ammonia stress minimally impacted the sensory profiles of both species. Gut microbiota analysis revealed species-specific differences, with Lactococcus lactis dominating hybrid catfish communities. The second study evaluated buffered vinegar treatment (1.5%) on fillet shelf life during refrigerated storage. Vinegar-treated fillets maintained better microbiological quality, with aerobic plate counts remaining below 7 log cfu/g through day 6, while untreated fillets exceeded …

Evaluation Of Plant Growth Regulators On Sweetpotato Slip Propagation, Kerington Lyn Bass

Theses and Dissertations

Sweetpotato production is often impacted by high mortality of slips during transplantation to the field, particularly with greenhouse-grown slips. These slips develop thinner stems, thus being more vulnerable to transplant shock, resulting in reduced establishment. To address this issue, the study evaluated the effects of four plant growth regulators on the morphological and anatomical characteristics of sweetpotato slips. In the first experiment, external growth parameters were recorded over four weeks, followed by post-harvest assessments of plant and root material. In the second experiment, the widths of various stem structures in stained cross-sections of slip stems were measured. Results showed that …

The Effects Of Ataxin-1 Overexpression In The Central Nervous System On Specific Behavioral And Physiological Characteristics Of Drosophila Melanogaster, Sydney Davis

Theses and Dissertations

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited neurodegenerative disease caused by a CAG repeat expansion in the ataxin-1 gene, which results in an abnormally long polyglutamine tract. Similarly, overexpression of wildtype Ataxin-1 (wt-Atx-1) in Drosophila melanogaster leads to neurodegeneration, reduced lifespan, and impaired negative geotaxis. Observations include disruptions in sleep-wake cycles, increased oxidative stress biomarkers (like protein carbonyls), and dysregulation of developmental genes such as armadillo (arm) and nemo kinase (nmo). Additionally, elevated expression of SUMOylation-related genes (Aos-1, Uba2, and dSmt3 or dSumo) and increased SUMO protein levels indicate enhanced SUMOylation in the brain. Quantitative analysis of neuronal …

Evaluating The Efficacy Of Functional Feed Additives In Broilers With Or Without A Live Coccidiosis Vaccine Challenge, Dalton Gerard Dennehy

Theses and Dissertations

Functional feed additives, such as probiotics, prebiotics, and phytogenics, have seen increased usage in commercial poultry production due to their ability to improve growth performance, meat yield, and overall health status. Therefore, the objective of this research was to evaluate the efficacy of functional feed additives in broilers with or without an enteric challenge induced via a live coccidiosis vaccine (LCV). In the first study (Chapter II), broilers were raised on used litter without an LCV challenge and fed varying levels of a multi-strain Bacillus-based probiotic in the starter phase (1x or 2x dose). Reduced performance was observed in early …

Impact Of An Automated Brush System On Intensively Managed Lactating Dairy Cattle Behavior, Production, And Stress Physiology, Allison Lyn Griffin

Theses and Dissertations

The dairy industry has increasingly prioritized improving animal welfare for intensively housed cows. This study evaluated the effects of environmental enrichment (EE) using an automated brush system on stress physiology, behavior, and productivity of lactating dairy cows. Fifty-nine pregnant and lactating dairy cows were divided into two groups: CON (no brush) and TRT (automated brush system). Saliva samples were collected to measure cortisol concentrations, and behaviors were monitored in the morning (07:00 h - 11:00 h) and evening (19:00 h - 23:00 h) using high-resolution cameras. The results indicated that cows with brush access had lower cortisol concentrations, suggesting reduced …

Exploring Sexual Dimorphism In A Drosophila Melanogaster Model Of Spinocerebellar Ataxia Type 1, Madelyn Hunter

Theses and Dissertations

Neurodegenerative diseases affect over 36 million people and are characterized by loss of motor control, neuronal degradation, and behavioral changes. The most common of these diseases exhibit sexually dimorphic effects. In this study, Spinocerebellar ataxia type 1 (SCA1) was modeled in the Drosophila central nervous system using the yeast hybrid UAS/GAL4 system. Locomotor activity and clock gene expression was monitored for male and female SCA1 and control flies. Clock genes such as per, tim, Clk, and cyc were monitored over a 24-hour period using qRT-PCR, and distinct sexual dimorphism was detected in locomotor activity and in gene expression for SCA1 …

Biomechanics Of Softball Pitching And The Relationship Between Functional Field Tests And Pitching Performance, Joshua Spencer Johnson

Theses and Dissertations

Over 2 million people in the United States play softball alone, yet softball literature in exercise science and biomechanics is still sparse. Research that exists for softball pitching has focused on injury mechanisms and prevention, with a small portion of the literature reporting on performance. Studies have reported evidence suggesting that vertical ground reaction forces of the stride leg are related to pitch velocity. However, no studies have investigated the role of the stride leg during the initial launch phase of the pitch. Research has investigated kinematics such as pelvic and thoracic rotation during the pitch, but no research has …

Evaluating The Use Of Translucency Score As An Effective Parameter Of Eggshell Quality, Cassidy Autumn Morris

Theses and Dissertations

The objective of this thesis was to determine if an egg’s translucency score (TS) could be used as an effective predicting parameter to determine eggshell quality in both broiler breeders and commercial laying hens. In broiler breeders, it was determined that TS could be used as an effective predicting parameter for eggshell thickness (P< 0.001) and L* scores (P< 0.001). It was also found that the supplementation of organically sourced trace minerals could significantly decrease the TS of eggs, resulting in a better-quality eggshell (P< 0.001). In two different aged commercial laying hen experiments, there was no conclusive evidence for TS to be a predictive parameter of eggshell quality throughout the storage period. It was found, however, that the storage period did significantly increase the TS throughout storage in both experiments (P< 0.001).

The Effect Of X-Ray Irradiation Technology On Salmonella Spp. And Quality Parameters Of Ready-To-Bake Chocolate Chip Cookie Dough, Kala Grace Morris

Theses and Dissertations

Salmonella contamination in cookie dough poses a threat to consumers. This study investigated the effect of X-ray irradiation on Salmonella-inoculated ready-to-bake chocolate chip cookie dough and its impact on dough quality. A Salmonella cocktail (~10 log CFU/g) was prepared and inoculated into cookie dough samples (~6.5 log CFU/g) and then treated with X?ray irradiation (0.25, 0.5, and 1 kGy). Salmonella decreased by 1.15, 1.79, and 2.49 log CFU/g, at an exposure of 0.25, 0.5, and 1 kGy, respectively. Quality parameters (pH, aw, and colorimetry) were evaluated for two brands. No statistical difference (P>0.05) in pH was observed for Brand …

Ecology And Management Of Alligatorweed (Alternanthera Philoxeroides) And An Associated Thrips Biological Control Agent (Amynothrips Andersoni), Samuel Alec Schmid

Theses and Dissertations

Alligatorweed (Alternanthera philoxeroides), native to South America, is a highly invasive aquatic macrophyte that is globally distributed and particularly problematic in the southeastern United States. In the United States, alligatorweed management has a long history, particularly of chemical and biological control. Alligatorweed management saw early success with a South American flea beetle (Agasicles hygrophila), but this agent’s utility has waned. Despite the long history of alligatorweed invasion, several important research questions remain, and the research in this dissertation seeks to answer some of these questions. This research focuses on multiple and diverse aspects of alligatorweed biology, ecology, and management: (1) …

Assessing The Kinematics And Kinetics About The Knee With An Isokinetic Dynamometer And Force Plates During Field-Based And Lab-Based Trials., Samantha Ann Searles

Theses and Dissertations

The incidence rate in knee injuries has increased over the last 20 years, with women at a 2-8 times higher incidence rate compared to men. This is likely a result of lower neuromuscular control of the trunk, generating less hip muscle activation, and more reliance on the quadriceps, alongside reduced hip, knee, and dorsiflexion angles, paired with increased knee valgus angles, ground reaction forces (GRF), hip adduction, and knee rotation upon landing from jumps. The focus of this study is to determine if knee kinetics and kinematics during field- and lab-based trials are associated with knee injury predictors. Theoretically, if …

Combined Effect Of Chitosan And Lemon Essential Oil-Infused Slush Ice On The Shelf Life Of Channel Catfish, Dianna Wilson

Theses and Dissertations

The objective of this research was to investigate the biopreservative effects of chitosan and lemon essential oil in slush ice treatments on the microbial shelf life of refrigerated catfish fillets. Catfish fillets were stored in slush ice treatments containing chitosan (CH), lemon essential oil (LO), a combination (CH+LO), water (CTRL), and no slush (NS) for three d at 4 C, then stored at 4C for twelve d post-slush. The growth of background microflora in catfish fillets treated with CH and CH+LO was reduced (P<0.05), maintaining total aerobic counts below 4.5 log CFU/g, while the control reached spoilage levels (>7 log CFU/g) by Day 6. Chitosan effectively extended the microbial shelf life but lowered pH, …

Myxozoan Diversity And Life Cycles In Catfish Production Ponds In Mississippi, Usa, Ethan Woodyard

Theses and Dissertations

Catfish aquaculture is a critical industry in the United States and Mississippi in particular. The industry is beset by depredation, rising feed costs, competition with imports, and loss to disease. Chief among these is the myxozoan parasite and causative agent of proliferative gill disease, Henneguya ictaluri. In chapter 2, novel molecular markers for greater resolution in species identification of these parasites are provided, allowing more robust life cycle inference, species-level identifications, and inference of evolutionary relationships through molecular phylogenetic analyses. Chapters 3–5 apply the approaches developed in Chapter 2 to a broad array of taxa beyond catfish-infecting Henneguya spp. These …

Evaluating The Feeding Value Of Almond Hulls And The Supplementation Of Carbohydrases On Performance, Egg Quality, Nutrient Digestibility And Intestinal Health In Lsl-Lite Hens, Nelly Giovanna Cribillero Chuquihuaccha

Theses and Dissertations

Almond hulls (AH) are a by-product of the almond nut processing rich mainly in insoluble fiber. Addition of fiber in the diet has been shown positive results in performance in poultry. However, scientific literature on the use of AH in poultry is limited. The objective of this dissertation was to determine the effect of the supplementation of ground AH and cellulase-xylanase carbohydrase enzyme (E) inclusions on performance, egg quality, ileal nutrients digestibility, jejunum gene expression and ceca microbiota of Lohmann LSL-Lite pullets and laying hens from 0 to 70 weeks of age. Chapter I describe the knowledge on the composition …

Assessment Of Pagp Gene Function In Avian Pathogenic Escherichia Coli Pathogenicity Using Different Challenge Models, Hailey Fugate

Theses and Dissertations

Avian pathogenic Escherichia coli (APEC) is a leading cause of morbidity and mortality in poultry, contributing an estimated $40 million in annual losses in the U.S. broiler industry alone, and contributing to growing concerns over antibiotic resistance. This study investigated the role of the pagP gene, which encodes a lipid A palmitoyl transferase involved in immune evasion, using both a broiler chick and embryo challenge model. Deletion of pagP significantly reduced mortality and lesion severity in broilers, indicating its role in APEC pathogenicity. However, in embryos, pagP deletion had minimal effects on survival and bacterial colonization, suggesting alternative virulence mechanisms …

Evaluation Of Broiler Performance And Processing Metrics Through Sodium Bisulfate Application To Litter And Varying Inclusions In Feed, Samantha Suzanne Plocher

Theses and Dissertations

Poultry producers must continuously evaluate current practices and determine new ones to further optimize broiler production. Sodium bisulfate (SB) is used as a poultry litter amendment (SBL), but also in human food to control pH; thus, initiating interest for SB in feed (SBF) for performance and gut health benefits. This thesis utilized common diets varying in SBF (Chapters II and III) and SBL (Chapter II; SBL1- d 0 and SBL2 – d 0 and 18) to optimize 40 d broiler performance, litter quality, and d 41 processing metrics. For Chapter II, d 0 SBL1 dramatically lowered litter pH, while minimally …

Sustainable Process Valorization For Bioactives From Invasive Plants Environmental Burden And Their Efficacy As Antimicrobial Agents, Shamprasad Br

Theses and Dissertations

Agri-food industries produce large quantities of fruit waste which are usually discarded and one such major beverage juice waste is Citrus waste. Likewise, invasive plants like Prosopis juliflora, which is richly distributed across Tamil Nadu, are underutilized for secondary metabolites/bioactives isolation. Halophytes are another rich source of bioactives present around mangrove forests and distributed in the salt rich marshy land.

1. Separation of phenylpropanoids from the Citrus waste through solvent extraction and pH-assisted precipitation was developed. The PPCM precipitated (phenylpropanoids form Citrus medica) were analysed by HPTLC and were found to contain Rutin, Naringin, Quercetin-3-beta-glycoside, Chlorogenic acid, Ferulic acid and optimization …

Unpaired Virtual Histological Staining Of Tissue From Autofluorescence Using Regularized Cycle-Consistent Adversarial Networks, Zhesi Wen

Theses and Dissertations

We present a regularized CycleGAN with a Dense Residual U-Net to virtually stain autofluorescence images of tissue into H&E-like images. Our method outperforms standard architectures, reduces artifacts, and achieves superior FID scores, enabling efficient, label-free, and accurate digital pathology for unpaired datasets using multi-channel fluorescence inputs.

Quantification Of Blue Carbon Within The Marine Animal Forest On The Rio Grande Valley Artificial Reef, Michelle Kathryn King

Theses and Dissertations

The protection and enhancement of coastal ecosystems provides a number of benefits such as heightened biodiversity, increased fisheries, and enhanced carbon capture (Yeemin et al., 2024). The study of blue carbon ecosystems has expanded rapidly in the last two decades since the term was coined in 2009 (Lovelock & Duarte, 2019). The most well-known blue carbon ecosystems include vegetation-dominated ecosystems such as seagrass meadows, salt marshes, and mangrove forests (Howard et. al., 2014). Prior studies have overlooked Marine Animal Forests (MAF) ability to capture carbon, until recent studies on soft coral (Coppari et al., 2019) and sponge (Rix et al., …

Cover Crop-Induced Improvements To Soil Hydraulic Properties And The Role Of Termination Time In Mitigating Negative Soil Moisture Impacts, Fabrizio Javier Pilco

Theses and Dissertations

In the Lower Rio Grande Valley of South Texas, water scarcity and drought pose ongoing challenges for farmers. Although cover crops are promoted for improving soil health and moisture, their effects on soil hydraulic properties in this region remain understudied. This thesis addresses both long-term (Chapter 2) and short-term (Chapter 3) impacts of cover crops on soil hydraulic properties and soil moisture. Long-term effects were evaluated through a three-year participatory field trial across four farms using a BACI design, while short terms were evaluated using a complete randomized block design. Soil hydraulic properties (residual water content θr, saturated water content …

Drug-Target Binding Affinity Prediction With Graph-Based Models: The Impact Of 3d Structural Information, Angel Antonio Peredo

Theses and Dissertations

Drug–target affinity (DTA) prediction is a critical step in accelerating drug discovery and reducing its associated costs. Existing computational approaches often employ one-dimensional protein sequences or two-dimensional molecular graphs, which can overlook important three-dimensional (3D) structural features. The present study investigates whether incorporating 3D information of both proteins and ligands can yield more meaningful representations for binding affinity prediction. Specifically, Graph Transformers (GT) are utilized, and the integration of Equivariant Graph Neural Networks (EGNN) is explored to preserve and leverage spatial information during learning.

Using the CrossDocked2020 dataset, which provides protein structures in Protein Data Bank (PDB) format, proteins and …

Identification Of Cadmium As A Structural And Functional Modulator Of Psd-95 Regulating Nmdars At Postsynaptic Membranes, Claudia Garza

Theses and Dissertations

Postsynaptic density-95 (PSD-95) is an essential scaffolding protein in excitatory neurons. PSD-95’s N-terminal palmitoylation region elicits synaptic plasticity by targeting, anchoring, and trafficking glutamate receptors, such as N-methyl-d-aspartate receptors (NMDAR), to the postsynaptic membrane. The molecular interactions of PSD-95 and its dysregulation in excitatory synapses are currently being explored as primary causes of neurodegenerative diseases and disorders, such as Alzheimer’s disease, Schizophrenia, and Parkinson’s disease. Recent studies demonstrate an overaccumulation of zinc at two cysteines (C3 and C5) and two histidines (H24 and H28) of PSD-95 blocks palmitoylation, causing a loss of NMDAR at the postsynaptic membrane. In addition, exposure …

Climate Resilience In Texas Assessing The Impact Of Extreme Weather On Energy Poverty And The Mitigating Role Of Tree Canopy Coverage, Yongwen Yang

Theses and Dissertations

Extreme weather events, including severe heat and cold waves —increasingly threaten public health, economic stability, and energy equity. This two-part study examines the interplay between extreme weather, energy poverty, and green infrastructure (tree canopy coverage) in Texas, a state characterized by climatic extremes and socioeconomic diversity.

This study consists of four chapters. The first chapter in the Introduction includes the research background, existing research, research gaps, research questions, and potential contributions. Followed by two core chapters. Chapter II aims to assess the impact of extreme weather on energy poverty at the household level. Chapter III aims to identify whether tree …

Survival, Biofilm Formation, And Control Of Foodborne Pathogens In Hydroponic Systems, Sai Rithin Reddy Kothur Thirupathi

Theses and Dissertations

The growing global population and increasingly unpredictable weather patterns have intensified the demand for sustainable food production methods. Hydroponics, a form of Controlled Environment Agriculture (CEA), has gained attention as a viable solution due to its efficient use of resources such as land and water. Although hydroponic systems are perceived as safer alternatives to conventional farming, recent foodborne outbreaks associated with these systems have raised significant public health concerns. This thesis research investigated the food safety risk in hydroponic, particularly the survival and persistence of foodborne pathogens. Chapters I and II provide a comprehensive overview of hydroponics and the microbial …

The Influence Of Solar Energy Infrastructure On Pollinators And Crops, Deisy Garcia

Theses and Dissertations

As the human population grows, demand for agriculture and renewable energy rises. Landuse competition is caused by the expansion of area-intensive solar photovoltaic (PV) facilities. While solar energy is crucial to mitigate climate change, it presents challenges related to land availability and effects on habitats for essential pollinators. In Chapter II, a spatial analysis was conducted to examine the relationship between solar panel density and pollinator diversity, exploring regions with the least interaction between these two factors. Our findings can inform solar siting and management strategies at landscape levels, in conjunction with field studies, that both mitigate potential interaction and …

Cloning And Heterologous Expression Of Human Nachrs And A Unique Spider Venom Toxin, Christine M. Vega

Theses and Dissertations

Drug development research has long focused on synthesizing novel therapeutics while overlooking isolation from naturally available sources. Recently, the discovery of the therapeutic effects of highly bioavailable animal venom caused the field of venom research to soar in popularity. Animal venom serves as a natural, sophisticated tool optimized over millions of years by evolution with the ability to bind to ion channels such as nAChRs, non-specific ligand-gated ion channels distributed throughout the human nervous system, with high selectivity and specificity. However, purifying individual venom toxins from crude venom is challenging due to its availability. Therefore, synthesizing large quantities of venom …

A Comparative Study Of Urban And Natural Nesting Gray Hawks In The Lower Rio Grande Valley Of South Texas, Evan Farese

Theses and Dissertations

Urbanization can negatively impact birds of prey, which occupy higher trophic levels. The Gray Hawk (Buteo plagiatus) is a neotropical raptor inhabiting the Lower Rio Grande Valley (LRGV) of Texas, where it is threatened. The species’ ecology has been little studied and it is unclear how urbanization may affect population viability. I studied Gray Hawk reproductive success, diet, and thermal ecology at nests in urban and natural habitats in the LRGV. Camera trap data showed adults at urban nests delivered mostly avian prey, while mammalian prey was most frequently brought to natural nests. Data from temperature loggers showed …

Transcription Factor Y- Box Binding Protein 1 (Ybx1) Enhances Sorafenib Resistance And Tumorigenic Capacities In Hepatocellular Carcinoma (Hcc), Dennis Kwabiah

Theses and Dissertations

Hepatocellular carcinoma (HCC) is the most common liver cancer, with early-stage cases potentially benefiting from surgical treatments like liver transplantation and hepatectomy. However, advanced HCC stages have poor prognosis due to resistance to therapies, especially sorafenib, a tyrosine kinase inhibitor approved for late-stage HCC. Despite its clinical use, sorafenib has limited efficacy in prolonging survival, and the mechanisms of resistance remain unclear. Analysis of The Cancer Genome Atlas (TCGA) HCC dataset shows elevated Y-box binding protein 1 (YBX1) expression in HCC tumors compared to normal liver tissues. Previous studies have indicated that YBX1 is involved in drug resistance in various …

Climate Change And The Field Of Farm Labor In The Lower Rio Grande Valley, Texas, Cody Richard Mortell

Theses and Dissertations

Farm workers in the United States are often vulnerable to adverse impacts of climate change, particularly extreme heat. This study explores farm workers’ climate change perceptions (CCP) as a mediating force in climate adaptation. Using latent class analysis, in-person survey data (n=404) from Lower Rio Grande Valley, TX (2024) and NOAA data were analyzed. Results were interpreted using Bourdieu’s field analysis framework and his notions of capital and symbolic power. Findings include: a social hierarchy with three latent classes of workers based on economic, cultural, social, and symbolic capital, which statistically significantly affected CCP. Workers in higher structural positions were …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …