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Full-Text Articles in Life Sciences

Disentangling Factors Contributing To Population Performance Of Zion Bighorn Sheep, Ian Montgomery May 2025

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 …


Optimizing Nutrient Recycling To Achieve Zero–Discharge Management For Controlled Environment Agriculture, Noah James Langenfeld May 2025

Optimizing Nutrient Recycling To Achieve Zero–Discharge Management For Controlled Environment Agriculture, Noah James Langenfeld

All Graduate Theses and Dissertations, Fall 2023 to Present

Controlled environment agriculture (CEA) allows for human control of one or more environmental factors affecting crop production. Optimizing nutrient management in such systems allows for translation and predictions of sustainable management strategies in the field. These systems will be used to supply fresh food as public and private space agencies are planning to send humans to the Moon and Mars in the near future. Food resupply becomes increasingly difficult as the distance from Earth increases. Plants can be grown off-Earth as a food source, but their growth must be carefully managed to ensure long-term sustainability. I describe a model used …


Investigating The Role Of The Hypocretin/Orexin System In A Novel Model Of Polysubstance Dependence, Tyler Zarin May 2025

Investigating The Role Of The Hypocretin/Orexin System In A Novel Model Of Polysubstance Dependence, Tyler Zarin

Electronic Theses and Dissertations

Substance use disorders (SUD) in the United States are steadily increasing. Potent and dangerous substances such as methamphetamine (MA) and fentanyl (FEN) are often co-used as a polysubstance (POLY), either intentionally or unknowingly as FEN is a common adulterant. SUD is characterized by physiological and psychological dependence involving the negative reinforcement of anhedonia and withdrawal which drive hypermotivated drug-taking behaviors. Current theory suggests that recruitment of hypocretin/orexin (HCRT) neuropeptide in reward and stress associated brain regions contributes to drug dependence. Despite strong evidence for HCRT’s role in mono-drug dependence, a relevant model for POLY dependence has yet to be developed, …


Intraspecific Genetic Variation In Green Salamanders (Aneides Aeneus) At Bays Mountain Park, Brianna Drake May 2025

Intraspecific Genetic Variation In Green Salamanders (Aneides Aeneus) At Bays Mountain Park, Brianna Drake

Electronic Theses and Dissertations

Accurate taxonomy is crucial for conserving vulnerable cryptic species like the green salamander (Aneides aeneus) in the Southern Appalachian Mountains. Prior studies identified three distinct lineages within the A. aeneus complex: Northern Appalachians, Southern Appalachians, and Blue-Ridge Escarpment. One previously collected sample indicated green salamanders in northeast Tennessee fit within the Northern lineage. The present study uses molecular data of A. aeneus at Bays Mountain Park (BMP) in Kingsport, Tennessee, to determine where the BMP population fits within these lineages. It was hypothesized that individuals from BMP belong in the northern lineage. Tail tips were collected from thirty-four …


Impacts Of Reef Fish Length On Foraging Radius: Exploring Behavioral Patterns Within A Patch Reef Ecosystem, Kilia Brawand May 2025

Impacts Of Reef Fish Length On Foraging Radius: Exploring Behavioral Patterns Within A Patch Reef Ecosystem, Kilia Brawand

Undergraduate Honors Capstone Projects

Reef fish exhibit various behaviors upon the Great Barrier Reef. One of these behaviors includes that of limiting their grazing distances from a patch reef refuge to a certain maximum distance in order to avoid predators. This is defined as a ‘foraging radius’ or ‘margin of safety’. This ‘foraging radius’ varies among fish due to many factors- including species, morphology, ontogenesis, habitat complexity, and importantly: speed. Quicker fish can outswim predators to safety more efficiently than slower fish, and can therefore afford to travel farther distances to forage. Speed varies among fish for a number of reasons, including fish size …


Phylogeny And Historical Biogeography Of Uroleucon Aphids, Audrey Michelle Mullen May 2025

Phylogeny And Historical Biogeography Of Uroleucon Aphids, Audrey Michelle Mullen

Undergraduate Honors Capstone Projects

The aphid genus Uroleucon (Aphididae: Aphidinae: Macrosiphini) is a diverse group of about 230 species found globally in most temperate regions, principally in the northern hemisphere. Only 23 species are described from the southern hemisphere, in South American temperate regions such as Chile, Argentina, and Peru. However, the origins of the South American species are unknown, as are the relationships of these taxa to northern hemisphere Uroleucon species. This study seeks to establish the relationships between Uroleucon aphids native to South America and their North American and Eurasian counterparts using genetic data. We use phylogenetic analysis of cytochrome c oxidase …


Establishing Methods For In Vitro Static Culture Of Gut Microbiomes For Nutritional Intervention Studies, Jeremy Mathew Case May 2025

Establishing Methods For In Vitro Static Culture Of Gut Microbiomes For Nutritional Intervention Studies, Jeremy Mathew Case

Undergraduate Honors Capstone Projects

Lipid oxidation products (LOPs), which form during high-heat processing of oils common in Western diets, are known to cause inflammation and cellular damage. While LOPs have been implicated in exacerbating colitis and promoting colon tumorigenesis in mouse models, their direct impact on the gut microbiome remains poorly understood. This capstone project aimed to develop a low-cost in vitro protocol to culture the mouse gut microbiome under anaerobic conditions, enabling future investigations into the direct effects of bioactive dietary compounds such as LOPs. The study also assessed whether viable microbial communities could be recovered from fecal samples stored at -80°C. Fecal …


Transcription Factor Y- Box Binding Protein 1 (Ybx1) Enhances Sorafenib Resistance And Tumorigenic Capacities In Hepatocellular Carcinoma (Hcc), Dennis Kwabiah May 2025

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 May 2025

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 …


Improving Nutrition Outcomes Through Enhanced Allocative Efficiency Of Investments In 24 High Risk Counties In Kenya: An Optima Nutrition Modelling Study, Morris Ogero, Nick Scott, Veronica Kirogo, Anthony Ngugi May 2025

Improving Nutrition Outcomes Through Enhanced Allocative Efficiency Of Investments In 24 High Risk Counties In Kenya: An Optima Nutrition Modelling Study, Morris Ogero, Nick Scott, Veronica Kirogo, Anthony Ngugi

Population Health, East Africa

Introduction ;Undernutrition remains a significant global challenge, severely impacting children’s development and growth. To address this, the Sustainable Development Goals target a substantial reduction in stunting and wasting by 2025. Achieving these goals requires scaling up evidence-based nutritional interventions; however, limited budgets pose challenges in funding all necessary programs. To assist policymakers in making informed decisions, the World Bank developed the Optima Nutrition Modelling tool, which optimizes the allocation of nutrition investments. Kenya, with its high prevalence of stunting, was the focus of this study. Using the Optima Nutrition model, we aimed to (1) assess the impact of scaling up …


Assessing The Implicit Prices Of Health And Wellness Product Attributes In Pet Food: A Hedonic Analysis Approach, Lonnie Hobbs Jr., Andrew Anderson May 2025

Assessing The Implicit Prices Of Health And Wellness Product Attributes In Pet Food: A Hedonic Analysis Approach, Lonnie Hobbs Jr., Andrew Anderson

Agricultural Economics and Agribusiness Faculty Publications and Presentations

Here we examine product attributes present in dry dog food to show there exist potential price premiums and discounts associated with health and wellness attributes in dry dog food. The findings indicate price premiums are associated with attributes related to digestion and allergy care. Pricing discounts are found to be associated with immune support and dental attributes. The results of this study are anticipated to be a starting point for more sophisticated and dynamic analysis of pricing and willingness-to-pay studies in the pet food industry.


Effects Of Environmentally Relevant Concentrations Of Roundup On Oxidative-Nitrative Stress, Cellular Apoptosis, Prooxidant-Antioxidant Homeostasis, Renin And Cyp1a Expressions In Goldfish: Molecular Mechanisms Underlying Kidney Damage During Roundup Exposure, Md Imran Noor, Md Saydur Rahman May 2025

Effects Of Environmentally Relevant Concentrations Of Roundup On Oxidative-Nitrative Stress, Cellular Apoptosis, Prooxidant-Antioxidant Homeostasis, Renin And Cyp1a Expressions In Goldfish: Molecular Mechanisms Underlying Kidney Damage During Roundup Exposure, Md Imran Noor, Md Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Roundup is one of the most widely used glyphosate-based harmful herbicides in the United States as well as globally, which poses a severe risk for terrestrial and aquatic organisms. In order to identify the detrimental effects of Roundup exposure in aquatic organisms, we investigated the environmentally relevant concentrations of Roundup exposure (low dose: 0.5 μg/L and high dose: 5.0 μg/L for 2 weeks) on renin expression, oxidative-nitrative stress biomarkers (e.g., 2,4-dinitrophenol, DNP; and 3-nitrotyrosine protein, NTP), prooxidant-antioxidant enzymes expressions (e.g., superoxide dismutase, SOD; and catalase, CAT), cellular apoptosis, and cytochrome P450 1A (CYP1A) mRNA levels in the kidneys of goldfish …


Comparison Analyses Of Consumer Acceptance, Evoked Emotions, And Purchase Intent Between Gluten-Containing Versus Gluten-Free Chocolate Chip Cookie Products, Shaelyn Frauenhoffer, Eniola Ola, Suzanne Jervis, Susan E. Gauch, Han-Seok Seo May 2025

Comparison Analyses Of Consumer Acceptance, Evoked Emotions, And Purchase Intent Between Gluten-Containing Versus Gluten-Free Chocolate Chip Cookie Products, Shaelyn Frauenhoffer, Eniola Ola, Suzanne Jervis, Susan E. Gauch, Han-Seok Seo

Food Science Faculty Publications and Presentations

The demand for gluten-free products has increased significantly over the past few decades. This study aimed to determine differences in consumer acceptance, emotional responses, and purchase intent between gluten-containing versus gluten-free chocolate chip cookies. Twelve commercially available chocolate chip cookie products from 11 brands were evaluated, including 7 gluten-free and 5 gluten-containing options. Eighty-nine participants without celiac disease took part in this 2-day study, evaluating six cookies per day. Participants rated sensory acceptance (appearance, flavor, texture, and overall liking) using a 9-point hedonic scale and evaluated specific sensory attributes (chocolate flavor, sweetness, chewiness, and hardness) using a 5-point just-about-right (JAR) …


Investigating Fatty Acid Influence On West Nile Virus In Mosquitoes And Birds, Hayley Moree May 2025

Investigating Fatty Acid Influence On West Nile Virus In Mosquitoes And Birds, Hayley Moree

Honors Program: Senior Projects (Public)

Vector-borne diseases, including Zika virus (ZIKV), Dengue virus (DENV), and West Nile virus (WNV), pose considerable global health threats, accounting for over 400 million infections and more than 700,000 deaths annually. Many vector-borne diseases are within the Flaviviridae family. Despite this, effective treatments have not been found for some flaviviruses. Flaviviruses exploit host cellular machinery to facilitate their replication and survival, reprogramming metabolic pathways, including lipid metabolism. Lipids play essential roles in the viral life cycle, providing structural components for the viral envelope, enabling membrane rearrangements for replication complexes, and supplying energy resources necessary for particle assembly.

Targeting lipid metabolism …


Novel Chloroviruses With Unique Glycans On Their Major Capsid Proteins, Cayden J. Homolka May 2025

Novel Chloroviruses With Unique Glycans On Their Major Capsid Proteins, Cayden J. Homolka

Honors Program: Senior Projects (Public)

Chloroviruses, of the family Phycodnaviridae, are large, dsDNA viruses with a genome of 290 to 410 kb. These virus genomes are so large that they are classified as “giant viruses”. Within this genome, up to 16 tRNAs and 330 to 450 proteins are encoded. Among the massive amounts of genes and proteins are unique carbohydrate synthesis/metabolism genes, which are responsible for the glycosylation of chloroviruses major capsid proteins. In most viruses, these proteins are glycosylated by the host enzymes located in the endoplasmic reticulum. Instead, Chloroviruses encode their own glycosylation machinery; essentially decorating themselves. Furthermore, these chlorovirus glycans are unlike …


Investigation Into Mycorrhizae Associated With Native Venus' Flytrap Root Tissue, Anna Carnaggio May 2025

Investigation Into Mycorrhizae Associated With Native Venus' Flytrap Root Tissue, Anna Carnaggio

Electronic Theses and Dissertations

Dionaea muscipula, a plant commonly known as the Venus' flytrap, is found native to the southeast corner of North Carolina and the northeast corner of South Carolina. Several populations of native Venus' flytraps are known to exist in the nutrient-poor peat bog conditions in and around Lewis Ocean Bay Heritage Preserve (LOBHP) in Northeastern South Carolina. Anthropogenic pressures in Horry County, specifically surrounding LOBHP, have resulted in a loss of habitat for several native and endangered species. As a result, conservation efforts are focused on relocating native Venus' flytraps into adjacent habitats to ensure survival. This is only a temporary …


Understanding The Impact Of Fall Armyworm (Spodoptera Frugiperda) Feeding, And Drought Stress On Drought-Tolerant And Drought-Resistant Soybean (Glycine Max)., Adriana G. Peissel May 2025

Understanding The Impact Of Fall Armyworm (Spodoptera Frugiperda) Feeding, And Drought Stress On Drought-Tolerant And Drought-Resistant Soybean (Glycine Max)., Adriana G. Peissel

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Drought and insect herbivory are two major stressors on high-value crops like soybean (Glycine max). However, few studies have explored how these stressors interact, despite their presence in tandem under field conditions. We investigated how drought stress and fall armyworm (Spodoptera frugiperda) caterpillar herbivory impact Magellan (drought-tolerant) and Blackhawk (drought-susceptible) soybean cultivars. The soybean plants were subject to four treatment groups (1. Drought 2. Herbivory 3. Drought + Herbivory 4. Well-Watered) during a treatment period of 7 days in a greenhouse. We then measured plant height, physiological traits, trichome density, soil moisture, and larval mass gain. …


Understanding Factors That Drive Wildlife Mortality During Prescribed Fire Management Of Prairie Restorations, Hunter M. Griffey May 2025

Understanding Factors That Drive Wildlife Mortality During Prescribed Fire Management Of Prairie Restorations, Hunter M. Griffey

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Fire is a key ecological disturbance, which plays a vital role in maintaining biodiversity and early successional species. For today’s land managers, prescribed fire is key in the restoration and maintenance of prairie ecosystems, halting woody encroachment and creating habitat desperately needed by many species. However, fire may have unintended effects on wildlife populations through direct mortality. Among taxa living in fire-dependent ecosystems, reptiles are predisposed to direct mortality, and several studies have recorded significant mortality during prescribed burns. However, the few studies investigating reptile mortality in prescribed fire are limited by small sample sizes and generally have limited analysis …


A Stakeholder-Informed Conceptual Framework For Evaluating Genomics In Precision Oncology, Julie A. Wiedower May 2025

A Stakeholder-Informed Conceptual Framework For Evaluating Genomics In Precision Oncology, Julie A. Wiedower

All Dissertations

This dissertation explores the value of genomic testing in precision oncology with an emphasis on how US payers conceptualize and prioritize elements of value. This research aims to address gaps in understanding payer perspectives and proposes a stakeholder-informed framework for evaluating genomic testing in oncology. To achieve this aim, the presented research investigates payer perspectives, value-based cancer care priorities, and the conceptual understanding of the value of a genetic diagnosis to establish a framework for value with the payer audience in mind. Chapter 1 outlines relevant background information relating to the genomic revolution and challenges in translating genomic testing technologies …


The Genomic Landscape And Prognostic Impact Of Kras, Stk11, And Smarca4 Mutations And Co-Mutations On Survival Outcomes In Non-Small Cell Lung Cancer, Peter Manolakos May 2025

The Genomic Landscape And Prognostic Impact Of Kras, Stk11, And Smarca4 Mutations And Co-Mutations On Survival Outcomes In Non-Small Cell Lung Cancer, Peter Manolakos

All Dissertations

Non-small lung cancer (NSCLC) accounts for 85% of lung cancer cases, and Kirsten rat sarcoma viral oncogene homolog (KRAS), Serine/Threonine Kinase 11 (STK11), and SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4 (SMARCA4) mutations and co-mutations have been increasingly recognized for their potential prognostic significance. However, clear knowledge gaps remain regarding which treatments should be selected for patients who present clinically with KRAS/STK11 or KRAS/SMARCA4 co-mutations, as outlined in Chapter 1. Despite significant clinical development advancements in immunotherapy and targeted therapy, a deeper understanding of the influence of these genomic …


Toward The Application Of Natural Language Processing In Electronic Health Record Analysis For Taxonomy Development, Latoya Mcdonald May 2025

Toward The Application Of Natural Language Processing In Electronic Health Record Analysis For Taxonomy Development, Latoya Mcdonald

All Dissertations

Electronic health records (EHRs) are pivotal resources for nurse practice because they increase the timeliness and reliability of patient information at the point of care and support access by multiple healthcare providers and the individual patients themselves. However, it is widely recognized that data extraction from EHRs is challenging due to the variability in the language used in clinical care notes and the lack of standardized terminology across healthcare systems. The broad objective of this dissertation is to develop taxonomy-based classification models for nursing care by applying feature engineering approaches to EHRs that include nursing care of ostomy patients following …


Development Of Small-Molecule Inhibitors For Bacteroides, Naegleria, And Toxoplasma Microorganisms And Synthesis Of N-Heterocycles From Thiolated Ene-Ynes And Azodicarboxylates, Samuel Kwain May 2025

Development Of Small-Molecule Inhibitors For Bacteroides, Naegleria, And Toxoplasma Microorganisms And Synthesis Of N-Heterocycles From Thiolated Ene-Ynes And Azodicarboxylates, Samuel Kwain

All Dissertations

Humans and microorganisms are intricately interconnected, with microbes constituting an essential component of human biology and ecology. This interdependence necessitates a delicate balance between leveraging beneficial microbes and mitigating the impact of harmful ones. The human gut microbiome, home to trillions of microorganisms, predominantly comprises commensal species that support health. However, dysbiosis within this ecosystem has been linked to serious diseases. For instance, an overrepresentation of Bacteroides species is associated with Type I diabetes mellitus (T1D) and various chronic gut disorders, including ulcerative colitis, inflammatory bowel disease, celiac disease, and colorectal cancer. Similarly, Naegleria fowleri, a free-living amoeba, causes …


Exploring Community Change Of North American Stream Fish Communities Due To Species Introductions, William K. Annis Jr May 2025

Exploring Community Change Of North American Stream Fish Communities Due To Species Introductions, William K. Annis Jr

All Dissertations

The introduction of nonnative species has facilitated global changes in beta diversity, and these changes have been coined biotic homogenization (loss in beta diversity) and differentiation (gain in beta diversity). Homogenization represents a key conservation threat. Therefore it is imperative to understand the processes that allow nonnative species to establish and how these species contribute to beta diversity change. In this dissertation, I assess three key challenges exist in our ability to address these goals. One challenge is that we have inconsistent support among hypotheses of invasion drivers due to context dependency. Context dependency can arise due to differences in …


Perspectives On Clinical Oncogenomics: Secondary Germline Variants Associated With Tumor Genomic Profiling In Community Cancer Care And Advanced Practitioner Oncogenomic Proficiency, Sarah Moncado May 2025

Perspectives On Clinical Oncogenomics: Secondary Germline Variants Associated With Tumor Genomic Profiling In Community Cancer Care And Advanced Practitioner Oncogenomic Proficiency, Sarah Moncado

All Dissertations

Precision medicine in oncology is defined by the sequencing of tumor genomic variants that can be used to identify targeted treatment for patients. Secondary pathogenic and likely pathogenic germline variants (P/LPGVs) can incidentally be detected on tumor genomic profiling (TGP). With the rise in precision medicine over the past 15 years, secondary P/LPGVs on TGP have been an increasingly important clinical issue. However, there are factors that can lead to misidentification and underreporting of P/LPGVs. Germane to this clinical practice issue is healthcare provider oncogenomic literacy and proficiency.

A scoping review was conducted to evaluate the variability of the prevalence …


A System And Method For Measuring Spatially Varying Surface Appearances With A Study Of Feathers, Jessica Baron-Lis May 2025

A System And Method For Measuring Spatially Varying Surface Appearances With A Study Of Feathers, Jessica Baron-Lis

All Dissertations

Real-world materials, particularly biological structures such as feathers exhibit complex appearances that vary spatially across their surfaces. The field of computer graphics provides a means of understanding such surfaces through material modeling which uses both analytical models and data acquired from light-surface interactions. There are many efforts within the past decade in measuring materials for graphics, but common limitations in these works include not accounting for spatially varying properties and reliance on neural networks and synthetic datasets.

Feathers from modern birds present diverse appearances due to how light interacts with their unique hierarchical microstructures. Variations in those structures lead to …


Identification And Characterization Of Intermediate Phenotypes To Decipher Genetic Architecture Of Stalk Lodging Resistance In Maize (Zea Mays L.), Bharath Kunduru May 2025

Identification And Characterization Of Intermediate Phenotypes To Decipher Genetic Architecture Of Stalk Lodging Resistance In Maize (Zea Mays L.), Bharath Kunduru

All Dissertations

Maize is a key contributor to global food security and incurs severe yield losses due to stalk lodging, the permanent displacement of plants from an upright growth habit due to mechanical damage to the stem (stalk). Stalk lodging resistance, an indicator of the stalk ability to resist lodging, is a complex trait and determined by several structural, geometric, and material properties of stalks, collectively referred to as intermediate phenotypes, whose identity and genetic framework are poorly understood. Therefore, progress in resolving the genetic architecture of stalk lodging resistance was impeded by a lack of standardized phenotyping methodologies and a poor …


Understanding The Genetic And Metabolic Underpinnings Of Complex Traits In C4 Grasses, Manwinder Singh Brar May 2025

Understanding The Genetic And Metabolic Underpinnings Of Complex Traits In C4 Grasses, Manwinder Singh Brar

All Dissertations

Maize (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) are two important cereal crops cultivated worldwide for food, animal feed, and industrial products. Productivity of these crops is significantly impacted by various biotic and abiotic stresses, such as diseases, insect pests, drought, salinity, and heat. Among factors influencing crop performance under stress, the regulation of leaf longevity plays a critical role in determining yield. Leaf senescence is a highly regulated process essential for nutrient remobilization through the degradation of cellular components in aging leaves, but premature or accelerated senescence reduces photosynthetic efficiency and yield. Staygreen, a phenotype …


Spatial Variaiton In Host-Associated Microbiota, Daniel Malagon May 2025

Spatial Variaiton In Host-Associated Microbiota, Daniel Malagon

All Dissertations

Many organisms rely upon the internal and/or external microbial communities they harbor. Microbial communities which depend upon other organisms for survival are known as host-associated (HA) microbial communities. HA microbial communities differ in diversity and composition from surrounding environmental microbiota and are generally less diverse than surrounding soil microbiomes. Although distinct bacterial profiles exist between host and environment, microbial scale dispersal often links the two. For this reason, host and environmental microbial communities can be correlated (e.g., dominant taxa in HA microbiota are dominant in the host microenvironment or vice versa). Eukaryotic hosts act as islands for HA microbiota. Unlike …


Investigate The Use Of Nucleic Acids As Pesticides To Manage Major Pests And Pathogens Of Crops In South Carolina, Prasanna Valavanur Shekar May 2025

Investigate The Use Of Nucleic Acids As Pesticides To Manage Major Pests And Pathogens Of Crops In South Carolina, Prasanna Valavanur Shekar

All Dissertations

The sugarcane aphid (SCA, Melanaphis sorghi), first discovered on grain sorghum in late 2013, has gradually become a major insect pest of sorghum. It inflicts significant damage to the crop year after year, causing millions of dollars in losses throughout the sorghum-producing regions of the United States. Similarly, Armillaria root rot—also referred to as oak root rot—is a major cause of decline in peach (Prunus persica) production in the southeastern United States. This disease is caused by Armillaria mellea and Armillaria tabescens. Current management practices for controlling M. sorghi include the use of synthetic pesticides, resistant varieties, and regular scouting. …


Amyloid Aggregation And Mitigation, Zhenzhen Zhang May 2025

Amyloid Aggregation And Mitigation, Zhenzhen Zhang

All Dissertations

The buildup of protein in tissues and organs plays a major role in unfunctional several serious diseases, including Alzheimer’s disease, Parkinson’s disease, and Type 2 diabetes, each tied to specific proteins that form harmful amyloid deposits. Amyloid aggregation typically follows a sigmoidal kinetic curve, beginning with a slow lag phase, followed by rapid fibril growth, and eventually reaching a plateau where mature, stable fibrils are formed. However, the early stage of aggregation remains particularly difficult to capture experimentally due to the highly dynamic nature and low abundance of small oligomeric species. In this dissertation, we employed discrete molecular dynamics (DMD) …