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Head Stabilization And Cortical Activation In Contact Sport Athletes During Walking Under Different Visual Task Constraints, Sam Zeff

Doctoral Dissertations

Contact sport participation exposes athletes to repetitive sub-concussive head impacts, which have been shown to elicit cortical neurophysiologic, cognitive, and motor performance alterations that have the potential to disrupt visual perception. Despite the growing concern regarding sub-concussive impacts, our understanding of their implications on motor performance and risk for further injury is limited. A stable head provides a consistent perceptual platform for the visual and vestibular sensory systems, but the effects of contact sport participation on head stability and visual perception remain poorly understood. The goal of this dissertation was to understand whether contact sport participation modifies athletes’ ability to …

Incorporating Biodiversity-Ecosystem Function Relationships Into Models And Conservation Planning, Sarah R. Weiskopf

Doctoral Dissertations

Unsustainable use of nature and climate change are leading to unprecedented biodiversity declines. These declines have cascading impacts on ecosystem function and ecosystem services, and ultimately on human well-being. International agreements have been adopted that aim to address both crises. The Paris Agreement, adopted in 2015, set global emission reductions targets. In 2022, most countries agreed to the Kunming-Montreal Global Biodiversity Framework (GBF). The GBF sets 23 ambitious targets for 2030 ranging from reducing threats to biodiversity, meeting people’s needs through sustainable use and benefit sharing, and solutions for implementation. Although adopting global goals and targets is an important first …

Atomistic Simulations Of Intrinsically Disordered Protein Folding And Dynamics, Xiping Gong

Doctoral Dissertations

Intrinsically disordered proteins (IDPs) are crucial in biology and human diseases, necessitating a comprehensive understanding of their structure, dynamics, and interactions. Atomistic simulations have emerged as a key tool for unraveling the molecular intricacies and establishing mechanistic insights into how these proteins facilitate diverse biological functions. However, achieving accurate simulations requires both an appropriate protein force field capable of describing the energy landscape of functionally relevant IDP conformations and sufficient conformational sampling to capture the free energy landscape of IDP dynamics. These factors are fundamental in comprehending potential IDP structures, dynamics, and interactions. I first conducted explicit solvent simulations to …

A Shift In Rna Fate: Investigating The Role Of C19orf66 During Kshv Lytic Replication, William Rodriguez Jr.

Doctoral Dissertations

During viral infection, virus and host clash for control of the cell in a conflict that ultimately drives the evolution of both sides and has lasting consequences in the form of pathogenesis. At the heart of this struggle is a contest for control of cellular gene expression, a struggle epitomized by an evolutionary tug-of-war for supremacy over RNA fate. During lytic replication, Kaposi’s sarcoma-associated herpesvirus (KSHV) triggers a massive RNA decay event known as viral “Host Shutoff” which decimates greater than 70% of the host transcriptome, simultaneously suppressing the cellular anti-viral response and freeing host resources for viral replication. However, …

Landscape Ecology And Conservation Of Freshwater Turtles Across The Eastern United States, H. Patrick Roberts

Doctoral Dissertations

Space use and movement patterns are integral to population dynamics and are often indicative of vulnerability to anthropogenic threats. Spatial ecology research can be fundamental to conservation strategies but is largely biased toward short-term intra- and interannual patterns. Without an understanding of space use over temporal scales commensurate with lifespan and the processes that may influence movement, conservation tools derived from short-term (2–4 yrs) movement patterns may be misguided or ineffective, particularly for long-lived species. The goal of Chapter 1 was to characterize the long-term (multi-decadal) spatial ecology of three long-lived (80–110 yrs) turtle species. We revisited six areas where …

The Role Of Lkb1 Spliceoforms In Itreg-Th17 Plasticity And Their Interactions With Pkcθ And Sirt1 Downstream Of Il-6 Signaling, Deeksha Mohan

Doctoral Dissertations

Following activation, CD4 T cells undergo metabolic and transcriptional changes as they respond to external cues and differentiate into T helper (Th) cells. T cells exhibit plasticity between Th phenotypes in highly inflammatory environments, such as colitis, in which high levels of IL-6 promote plasticity between regulatory T (Treg) cells and Th17 cells. Protein Kinase C theta (PKCθ) is a T cell-specific serine/threonine kinase that promotes Th17 differentiation while negatively regulating Treg differentiation. Liver kinase B1 (LKB1), also a serine/threonine kinase and encoded by Stk11, is necessary for Treg survival and function. Stk11 can be alternatively spliced to produce a …

Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi

Doctoral Dissertations

Anadromous river herring (alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis)) make annual spring spawning migrations from the ocean to freshwater, where juveniles reside before emigrating to the ocean. Climate change may alter environmental and biological cues that prompt both adult migration and juvenile emigration, with implications for adult spawning success and offspring survival for these imperiled species. Shifts in adult migration have been observed in some rivers, while impacts on reproductive success and juvenile survival remain unknown. Cues for juvenile emigration are poorly understood as they have been explored at limited spatial and temporal scales. …

The Consolidation Of Memory Associations, Kyle A. Kainec

Doctoral Dissertations

Creating memories is a fundamental challenge for the human brain. To create memories, defining features of experiences must be stored distinguishably without forgetting other memories. Memory associations represent co-occurring features and defining features across experiences. Memory associations are represented as networks of information that are stored in the brain. New memory associations are encoded during experiences and can be used to update existing memory associations during offline intervals. However, the mechanisms that underlie how encoded memory associations are stored within existing networks during offline intervals remains unclear. The experiments in this dissertation address a significant theoretical gap in understanding the …

Role Of Fat Content On The Structure And Function Of Human Skeletal Muscle, Joseph A. Gordon Iii

Doctoral Dissertations

Muscle size does not fully explain variations in muscle strength. Fat content has been implicated in muscle weakness, though this relationship remains unclear. The relationship between fat and strength may vary between scales (e.g., cellular, organ, and organism). The goal of this dissertation was to clarify the role of fat in the structure and function of muscle using in vitro and in vivo techniques across multiple scales in adults 21-45 years old. Study 1 tested the agreement of intramyocellular lipid (IMCL) content between oil red o (ORO) and magnetic resonance spectroscopy (MRS) techniques. These measures of IMCL were also compared …

Noradrenergic Regulation Of Decision-Making In Female And Male Rats, Emma S. Dauster

Doctoral Dissertations

Decision-making is regulated by many associated brain regions, including the locus coeruleus (LC) and the prefrontal cortex (PFC). Disruptions in decision-making are a key feature of many disorders including attention-deficit/hyperactivity disorder which is disproportionately diagnosed in one sex over another for reasons unknown. LC or its primary neurotransmitter norepinephrine (NE) have been implicated in the etiology or treatment of disrupted decision-making. Understanding the relationship among LC, PFC, and decision-making across sexes may provide insight into the basic neurobiology of cognition and disorders that lead to disrupted decision making. There are sex differences in LC anatomy, however studies investigating sex differences …

The Influence Of Spectral Quality On Primary And Secondary Metabolism Of Hydroponically Grown Basil, Hunter Albright Hammock

Doctoral Dissertations

This dissertation explores the influence of spectral quality from supplemental lighting and seasonal changes on primary and secondary metabolism in hydroponically grown greenhouse basil. It aims to enhance understanding of plant/light interactions and provide practical insights for light emitting diode (LED) manufacturers and commercial growers. The research is premised on the hypothesis that altering spectral quality can significantly impact primary and secondary metabolism, potentially improving flavor and increasing phytonutrients with health benefits. This project involved four phases, each building on the results of the previous ones. In Phase 1, different basil varieties were evaluated to determine aroma volatile profiles and …

Roles Of Soil Pores In Determining Water Retention And Microbial Dynamics, Huihui Sun

Doctoral Dissertations

Soil pore provides an essential habitat for microbial communities to participate in various biogeochemical processes. The complex pore spaces, which are defined by the arrangement of particles of varying sizes, govern the distribution of water for microbial dispersal and movement and microbial interaction with one another, such as bacterial cell-to-cell and bacterium-virus interactions. This research focused on exploring how soil pores influence soil water retention and bacterial interactions and quantify the spatial distribution of bacteria and viruses in fine-scale of soil pores. Using a mathematical model, this study simulated a soil water retention curve based on the relationship between soil …

"You're Not Thriving, You're Just Trying To Survive The Environment That You're In:" Mental Performance Consultants' Narratives Of Emotional Abuse In Sport, Victoria Lynn Bradshaw

Doctoral Dissertations

Emotional abuse is defined as “a pattern of deliberate non-contact behaviors by a person with a critical relationship that has the potential to be harmful” (Stirling & Kerr, 2008, p. 178). Specifically, in the context of sport, emotional abuse is one of the more frequently occurring forms of abuse (Kavanagh, Brown & Jones, 2017; Kirby, Greaves & Hankvisky, 2000; Wilson & Kerr, 2021). Years after the termination of those emotionally abusive experiences, athletes are left to try and cope with and manage the short and long-term impacts that tend to develop as a result of repeated exposure to harmful behaviors …

Retinoic Acid, Insulin, And Cycloheximide Alter Glycogen Homeostasis In Differentiating L6 Myoblasts, Aaron Armstrong

Doctoral Dissertations

Glycogen synthesis in skeletal muscle (SM) is responsible for the majority of post-prandial glucose disposal in healthy individuals. In type 2 diabetes mellitus (T2DM), compromised skeletal muscle glycogen synthesis contributes to hyperglycemia. L6 rat SM cells can develop insulin resistance with prolonged insulin stimulation and provide an in vitro model for mechanistic dysfunction in glycogen homeostasis. SM glycogen is synthesized by glycogen synthase (GS) in response to insulin stimulation. Canonically, insulin signaling increases GS activity through inhibition of its Ser641 regulator glycogen synthase kinase-3β (GSK3β) by protein kinase B (AKT). Proximal insulin signaling activates AKT via Ser473 phosphorylation which proceeds …

Population Abundance And Growth Of Elk (Cervus Canadensis) In Western North Carolina, Jessica Braunstein

Doctoral Dissertations

In an effort to restore extirpated elk to their previous range, 52 elk were reintroduced to Great Smoky Mountains National Park (GRSM) in North Carolina during 2001 and 2002. Since their reintroduction, elk numbers have increased and their range has extended beyond GRSM boundaries. My primary research objectives included estimating population abundance, apparent survival, per capita recruitment, and population growth rate of elk in North Carolina. I used spatially explicit capture-recapture (SECR) models based on fecal DNA to identify individual elk and estimate population abundance and growth in the region. Technicians and I walked a series of transects throughout the …

Phenotyping Regression In A Female Mouse Model For Rett Syndrome Using Computational Neuroethology Tools, Michael J. Mykins

Doctoral Dissertations

Regression is defined as loss of acquired skills over time and is a key feature of many neurodevelopmental disorders such as Rett syndrome (RTT). RTT is caused by mutations in the X-linked gene Methyl CpG-Binding Protein 2 (MECP2) and is characterized by a period of typical development with subsequent regression of previously acquired motor and speech skills in girls. In human and animal models, it is clear syndromic phenotypes are dynamic over time but phenotyping regression over time in animal models has remained elusive. Lack of established timelines to study the molecular, cellular, and behavioral features of regression in female …

Multidimensional Investigation Of Tennessee’S Urban Forest, Jillian L. Gorrell

Doctoral Dissertations

Preserving existing trees in urban areas and properly cultivating urban forest conservation and management opportunities is valuable to the ever-growing urban environment and necessary for creating optimal experiences and educational tools to meet the needs of increasing urban populations. This dissertation contains studies investigating several facets of the urban forest, including environmental effects of deforestation and urbanization, tree equity, and urban forest facility management and accessibility. Community education and outreach at arboreta about the importance of the tree canopy can help promote environmental stewardship. A digital questionnaire was electronically distributed to representatives of arboreta certified through the Tennessee Division of …

Increasing Productivity And Biodiversity Of Tall Fescue Swards By Intercropping Cool And Warm-Season Forage Species, Michael Dereck Corbin

Doctoral Dissertations

Mixed pastures are known to produce greater biomass yields and higher nutritive value than monocultures. Intercropping biologically N fixating legumes, along with the use of intercropping warm-season annual grasses, such as crabgrass [Digitaria ciliaris Retz.], provides the potential to aid tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] productivity. To determine the benefits of intercropping species into tall fescue forage systems in the Southeastern U.S., two studies were developed. The first study consisted of 9 tall fescue paddocks, in which 3 paddocks contained red clover (Trifolium pratense L. [TRC]) mixed with tall fescue, 3 paddocks contained sunn …

Application Of Machine Learning Approaches To Empower Drug Development, Yue Shen

Doctoral Dissertations

Human health, one of the major topics in Life Science, is facing intensified challenges, including cancer, pandemic outbreaks, and antimicrobial resistance. Thus, new medicines with unique advantages, including peptide-based vaccines and permeable small molecule antimicrobials, are in urgent need. However, the drug development process is long, complex, and risky with no guarantee of success. Also, the improvements in techniques applied in genomics, proteomics, computational biology, and clinical trials significantly increase the data complexity and volume, which imposes higher requirements on the drug development pipeline. In recent years, machine learning (ML) methods were employed to support drug development in various aspects …

Methods To Hasten Zoysiagrass Establishment From Sprigs, Tyler Carr

Doctoral Dissertations

Zoysiagrasses (Zoysia spp. Willd.) are commonly used on golf course fairways and tees in addition to residential and commercial lawns due to lower input requirements relative to bermudagrass (Cynodon spp.). This has led to increased interest in using zoysiagrass for golf course putting greens; however, zoysiagrass establishment from sprigs is prolonged compared to bermudagrass. A series of experiments were conducted in glasshouses in Knoxville, TN in 2022 to evaluate the effects of environmental conditions and management practices on the establishment of Prizm zoysiagrass from sprigs. To determine the optimal soil temperature for Prizm zoysiagrass establishment, sprigs were exposed …

Effects Of A Movement-Based Curriculum On The Motor And Cognitive Development Of Preschool-Aged Children, Aaron Wood

Doctoral Dissertations

Physical activity has been shown to be positively associated with improved motor skill and cognitive development in young children. Intervention designs are often constructed without focus on interrelatedness of the development of motor and cognitive self-regulatory skills. Purpose: To investigate the impact of a movement-based curriculum designed to integrate both motor skill and cognitive development in preschool children. Methods: Preschool-aged children [n=34; intervention group (n=28); control group (n=6)] participated in the study. Locomotor and object control motor skills were assessed via the Test of Gross Motor Development – 3rd Edition. Cognitive self-regulation (attention, working memory, and inhibition) was assessed via …

Induction And Evasion Of Neutrophil Extracellular Traps By Campylobacter Jejuni And Its Implication In Disease, Sean M. Callahan

Doctoral Dissertations

Campylobacteriosis, the foodborne disease caused by Campylobacter spp., infects one out of 10 individuals every year. C. jejuni accounts for 90% of these infections resulting in numerous postinfectious disorders including the development of colorectal cancer, Guillain-Barré syndrome, irritable bowel syndrome, and reactive arthritis. Despite its large impact on human health, the host immune response to the bacterium is largely uncharacterized. Chapter two of this dissertation addresses the development of neutrophil extracellular traps (NETs) within human and ferret campylobacteriosis. We observed NET-associated proteins increase in the feces of C. jejuni-infected patients and that in vitro C. jejuni induces NETs, which …

Investigating Drivers Of Algal Bloom Succession In Lake Erie, Brittany Zepernick

Doctoral Dissertations

Harmful Algal Blooms (HABs) are algae undergoing prolific, unregulated growth. A well-documented HAB taxa is the cyanobacterium Microcystis spp., which induces anthropogenic, ecological, and economic consequences due to the production of toxins and biomass which results in lake hypoxia. Microcystis spp. blooms are globally distributed in freshwater systems, with climate change and the aquatic continuum serving to further exacerbate bloom distribution, duration, and frequency. Thus, there is a need to elucidate the factors driving the ecological success of Microcystis spp., and the ecological “failures” of their competitors, such as diatoms. In Lake Erie, a seasonal pattern of algal bloom succession …

Cell-Free Metabolic Engineering Strategies For Accelerated Biomanufacturing, Jaime Lorenzo N. Dinglasan

Doctoral Dissertations

Biomanufacturing propels the bioeconomy. Accelerating bioeconomic growth thus requires the expedited development of biomanufacturing processes that can expand the current bioproduct portfolio. Lysate-based cell-free systems provide unique advantages for simplified metabolic pathway construction. Their central metabolic pathways and transcriptional-translational (TX-TL) machineries are free from genome regulation and are amenable to direct manipulation, enabling the streamlined construction of biomanufacturing processes. While their utility as prototyping platforms for accelerating cellular metabolic engineering has been demonstrated, the potential to rapidly build commercial “cell-free factories” capable of sophisticated bioconversion has not been fully realized. Lysates with high-yield pathways are projected to enable commercialized cell-free …

Understanding Host-Microbe Interactions In Maize Kernel And Sweetpotato Leaf Metagenomic Profiles., Alison K. Adams

Doctoral Dissertations

Functional and quantitative metagenomic profiling remains challenging and limits our understanding of host-microbe interactions. This body of work aims to mediate these challenges by using a novel quantitative reduced representation sequencing strategy (OmeSeq-qRRS), development of a fully automated software for quantitative metagenomic/microbiome profiling (Qmatey: quantitative metagenomic alignment and taxonomic identification using exact-matching) and implementing these tools for understanding plant-microbe-pathogen interactions in maize and sweetpotato. The next generation sequencing-based OmeSeq-qRRS leverages the strengths of shotgun whole genome sequencing and costs lower that the more affordable amplicon sequencing method. The novel FASTQ data compression/indexing and enhanced-multithreading of the MegaBLAST in Qmatey allows …

Computational Analysis Of Microbial Sequence Data Using Statistics And Machine Learning, Zhixiu Lu

Doctoral Dissertations

Since the discovery of the double helix of DNA in 1953, modern molecular biology has opened the door to a better understanding of how genes control chemical processes within cells, including protein synthesis. Although we are still far from claiming a complete understanding, recent advances in sequencing technologies, increased computational capacity, and more sophisticated computational methods have allowed the development of various new applications that provide further insight into DNA sequence data and how the information they encode impacts living organisms and their environment. Sequencing data can now be used to start identifying the relationships between microorganisms, where they live, …

Airborne Transmission Of Pathogens Emerging In The Poultry Industry, Xuan Dung Nguyen

Doctoral Dissertations

Poultry houses might have high levels of airborne pathogens, including Escherichia coli (E. coli) and avian influenza (AI), which may be transmitted through the air and pose risks of infection. The objective of the dissertation is to provide an insightful understanding the of airborne transmission of E. coli and AI which were attached to poultry dust particles.

Chapter I and VI summarized background, gap in knowledge, and discussed the limitations and implications of the study.

Chapter II compared the efficiency of Andersen six-stage impactor, all-glass impinger, and ACD-200 Bobcat, in collecting airborne E. coli carried by dust particles. The results …

The Development Of Tailored Amphiphilic Copolymers For Detergent-Free Integral Membrane Protein Extraction, Cameron Edward Workman

Doctoral Dissertations

Integral membrane proteins are prolific targets for the design, development, and delivery of pharmaceuticals. In fact, over 60% of all currently available drugs target these proteins to accomplish their therapeutic effect. However, integral membrane proteins remain the least characterized class of all proteins, accounting for only ~2% of all solved protein structures. One of the primary reasons for this low number of solved protein structures is that many membrane proteins lose their native conformation when extracted using conventional methods (e.g. detergents), convoluting accurate structure determination. In contrast, amphiphilic styrene-maleic acid copolymers (SMAs) were recently discovered to readily isolate membrane proteins …

Role Of Kinases And An Epigenetically Regulated Gene In Soybean Cyst Nematode Resistance, Tracy Elizabeth Hawk

Doctoral Dissertations

Soybean cyst nematode (SCN) is the most devastating and economically important pathogen of soybean across the United States and globally. The current primary control for SCN is with the use of resistant cultivars, however, SCN populations are shifting to overcome most common sources of soybean resistance. This research was conducted to identify novel sources of genetic resistance to SCN. First, I functionally characterized two protein kinase hub genes whose function are predicted to be essential for mediating soybean susceptibility to SCN. I generated kinase-dead variants by mutating two amino acids required for the kinase enzymatic activity. Overexpression of the kinase-dead …

Unraveling Plant-Microbe-Microbe Interactions: Host And Microbial Colonization Determinants Across Experimental Scales, Bridget O'Banion

Doctoral Dissertations

Plant microbiomes are assembled and modified through a complex milieu of biotic and abiotic factors. Despite dynamic and fluctuating contributing variables, specific host and microbial mechanisms are likely important mediators of interactions. We combine information from large-scale datasets across diverse plant hosts with experimental genetic manipulation assays in model Arabidopsis seedlings to converge on a conserved role for metabolite production and transport in mediating host-microbe interactions. Applying a diverse set of analytical tools to microbial communities at various complexity levels will advance our knowledge of the scalability of observed phenotypes and, ultimately, help to decipher the mechanisms dictating plant–microbe interactions …