Life Sciences Commons^™

Reproductive Characteristics Of The Stripetail Darter (Etheostoma Kennicotti) Relative To Monogenean Gill Parasite Infection In Estill Fork In North Alabama, Joy L. Garcia, Zeina Celine Sleiman, Corinne N. Preacher, Bruce Stallsmith

Southeastern Fishes Council Proceedings

What relationship exists between Aethycteron sp. gill parasite infection and the reproductive characteristics of stripetail darters, Etheostoma kennicotti? 450 E. kennicotti were collected over 11 months from Estill Fork in Jackson County, Alabama. Gonads were removed and photographed. All oocytes were counted and then classified into one of four developmental stages based on size and appearance. Gill parasites belonging to the monogenean genus Aethycteron were excised, photographed, and counted. Sexual dimorphism in length and mass was observed in E. kennicotti. The number of males found at the 25> mm SL range far outnumbered the females while almost all …

Exploring Soil Microbial Dynamics In Southern Appalachian Forests: A Systems Biology Approach To Prescribed Fire Impacts, Saad Abd Ar Rafie

Doctoral Dissertations

Prescribed fires in Southern Appalachian forests are vital in ecosystem management and wildfire risk mitigation. However, understanding the intricate dynamics between these fires, soil microbial communities, and overall ecosystem health remains challenging. This dissertation addresses this knowledge gap by exploring selected aspects of this complex relationship across three interconnected chapters.

The first chapter investigates the immediate effects of prescribed fires on soil microbial communities. It reveals subtle shifts in porewater chemistry and significant increases in microbial species richness. These findings offer valuable insights into the interplay between soil properties and microbial responses during the early stages following a prescribed fire. …

The Identification Of Small Molecule Inhibitors To Candida Albicans Phosphatidylserine Synthase, Yue Zhou

Doctoral Dissertations

Candida albicans phosphatidylserine (PS) synthase, encoded by the CHO1 gene, has been identified as a potential drug target for new antifungals against systemic candidiasis due to its importance in virulence, absence in the host and conservation among fungal pathogens. This dissertation is focused on the identification of inhibitors for this membrane enzyme. Cho1 has two substrates: cytidyldiphosphate-diacylglycerol (CDP-DAG) and serine. Previous studies identified a conserved CDP-alcohol phosphotransferase (CAPT) binding motif present within Cho1, and here we revealed that mutations in all but one conserved amino acid within the CAPT motif resulted in decreased Cho1. For serine, we have predicted a …

Characterization Of Radiotolerance In Potato And Development Of A Gamma Radiation Phytosensor., Robert Graham Sears

Doctoral Dissertations

As humans pursue space travel and nuclear energy, the risk of harm from ionizing radiation increases. On Earth or in space, plants are essential to our personal and environmental health. Plants serve as sentinels, bioremediators and food sources in areas of high ionizing radiation, therefore it is essential to understand how ionizing radiation affects plant biology. This work aimed to understand plant responses to ionizing radiation in the potato chassis and apply that knowledge to generate novel phenotypes for nuclear energy and space applications. The first gamma radiation phytosensor was developed for monitoring at standoff distances greater than three meters. …

Impact Of Cadmium Stress On Soil Virus Reproduction And The Persistence Of Viruses Under Abiotic Conditions, Zhibo Cheng

Doctoral Dissertations

Soil viruses are ubiquitous and greatly impact the structure and function of soil microbial communities, with their effects modulated by various environmental factors. This study investigates the inactivation of naturally occurring soil viruses in sterilized soil, as well as the effects of cadmium (Cd) exposure and carbon (C) and nitrogen (N) nutrient availability on the population dynamics of virus-host communities in agricultural soil.

Lab-scale slurry and unsaturated experiments were performed to examine virus inactivation in the absence of host bacteria in sterilized soil. In slurry experiments, virus abundance declined by over 90% after 10 days of incubation. The addition of …

Integration Of Raman Spectroscopy And Python-Based Data Analysis For Advancing Neurobiological Research, Natalie E. Dunn

Doctoral Dissertations

The field of Raman spectroscopy continues to expand into biological applications due to its usefulness as a non-invasive technique that can be utilized qualitatively and quantitatively. However, the inherent weakness of Raman scattering leads to the need for each collected spectra to undergo a preprocessing step to remove noise, background drift, and cosmic rays. Biological research in particular needs large datasets due to the increased variability in samples. As datasets grow, the need to perform preprocessing on each individual spectra becomes daunting. Often, these steps are done by hand with the help of specialized software programs. Preprocessing can be accelerated …

Characterization Of Lignin Structural Variability And The Associated Application In Genome Wide Association Studies, Nathan D. Bryant

Doctoral Dissertations

Poplar (Populus sp.) is a promising biofuel feedstock due to advantageous features such as fast growth, the ability to grow on marginal land, and relatively low lignin content. However, there is tremendous variability associated with the composition of biomass. Understanding this variability, especially in lignin, is crucial to developing and implementing financially viable, integrated biorefineries. Although lignin is typically described as being comprised of three primary monolignols (syringyl, guaiacyl, p-hydroxyphenyl), it is a highly irregular biopolymer that can incorporate non-canonical monolignols. It is also connected by a variety of interunit linkages, adding to its complexity. Secondary cell wall …

Regulation Of Protein Synthesis In Arabidopsis Thaliana Through A Bioinformatic And Mathematical Lens, Ricardo Andres Urquidi Camacho

Doctoral Dissertations

Organisms exist under constantly varying environmental and internal conditions, which necessitate the differential regulation of gene expression. To synthesize proteins, the ribosome translates the information encoded in the nucleotide sequence of an mRNA into the final, functional amino acid sequence. Knockouts of ribosomal proteins lead to lethality. One such protein is the ribosomal protein 6 of the small subunit (eS6/RPS6). We confirmed that the knockout of either one of two eS6 paralogs in Arabidopsis leads to stunted growth and chlorosis. Here, these phenotypes have been further characterized in seedlings by precisely quantifying the ribosome loading of mRNAs as well as …

Assessing The Effects Of The Spring Hunting Season Start Date On Wild Turkey Seasonal Productivity And Hunter Behavior, Joseph Quehl

Masters Theses

Many states throughout the Southeast have documented declines in wild turkey (Meleagris gallopavo) harvest and estimates of recruitment in poult-per-hen ratios. Wild turkey populations are driven by seasonal productivity, so the decline in these parameters may indicate a decline in the overall population. One hypothesis as to why we are seeing a reduction in productivity and a potential population decline is that the spring hunting season is disrupting the reproductive cycle by harvesting too many males before they have had the opportunity to breed, or by harvesting dominant males and disrupting the social hierarchy of the flock. Our …

Bioregenerative Dietary Supplementation: Optimizing Brassica Production For Space Travel Through Light Intensity, Photoperiod, And Harvest Methodology, Ethan W. Darby

Masters Theses

Bioregenerative dietary supplementation, a component of bioregenerative life support, will be necessary for the success of future exploration-length space endeavors. Plants, as autotrophic producers of calories, nutrients, and oxygen, will be indispensable in the development of these systems. Previous work has identified leafy greens from the genus Brassica as promising candidates for in-flight production of necessary human nutrients such as vitamins C, B₁, and K₁, in addition to β-carotene, the primary vitamin A precursor in the human diet. These plants also produce lutein and zeaxanthin, two compounds important in protecting the eye from radiation-induced damage, as …

Variability In Microclimate And Carbon Dynamics In Hardwood Forests Managed With The Irregular Shelterwood Reproduction Method, Melody June Mount

Masters Theses

How do forest edges compare to intact interior forests in terms of carbon dynamics, and how is the microclimate altered through the creation of forest edges? Woody plants and trees can act as a carbon sink by using live and dead tissue to store varying amounts of carbon. However, factors such as age, species, respiration rates, and death alter the amount of carbon sequestered by the forest (Gorte, 2009). Additionally, widespread forest fragmentation has resulted in 20% of forests worldwide being located within 100 meters (m) of a forest edge (Haddad et al., 2015). Despite this fragmentation, current carbon models …

Exploring The Regulation Of A Bacillus Pumilus Bioplastic Degrading Protein, Elise Keara Phillips

Doctoral Dissertations

Biodegradable plastics are being adopted to reduce the environmental impacts associated with petroleum-based plastics, including long residence times, and reliance on fossil fuels as a feedstock. Microbial degradation of bioplastics is still poorly understood, which leads to inconsistent degradation outcomes and challenges for implementation. Bacillus pumilus B12 degrades the biodegradable bioplastic polylactic acid (PLA) via the protease AprE, but the regulatory mechanisms controlling aprE expression in B. pumilus B12 are largely unknown. To explore this question, we established developed a conjugation- based method to introduce DNA into B. pumilus B12 and diverse Bacillus species that is applicable to environmental and …

A Robust Agroinfiltration Method, Bryce N. Trull

Masters Theses

Stable transformation of soybean (Glycine max) is a markedly slow and laborious process. Thus, a tool that enables rapid evaluation of genetic elements in planta is critical to advance complex research and genetic engineering in soybean. To that end, a substantially robust agroinfiltration method was innovated in this work. Agroinfiltration is a technique that leverages Agrobacterium-mediated transient transformation to deliver genetic elements to the cells of whole plant tissues, usually leaves. Several factors were found to be relevant to successful soybean leaf agroinfiltration, including genotype, surfactant, developmental stage, and Agrobacterium culture medium. The research represents not only …

Novel Microbial Guilds Implicated In N2o Reduction, Guang He

Doctoral Dissertations

N₂O is a long-recognized greenhouse gas (GHG) with potential in global warming and ozone depletion. Terrestrial ecosystems are a major source of N₂O due to imbalanced N₂O production and consumption. Soil pH is a chief modulating factor controlling net N₂O emissions, and N₂O consumption has been considered negligible under acidic conditions (pH <6). In this dissertation, we obtained solids-free cultures reducing N₂O at pH 4.5. Furthermore, a co-culture (designated culture EV) comprising two interacting bacterial population was acquired via consecutive transfer in mineral salt medium. Integrated phenotypic, metagenomic and metabolomic analysis dictated that the Serratia population excreted certain …

Demand For Guided Tours On The Tennessee River., Gessika Lee Guerra

Masters Theses

Knoxville, TN is a major urban center in east Tennessee. Knoxville’s urban planners recognized the need for green space and have installed free greenways and parks within the downtown area over several decades. These attractions are immensely popular and promote urban ecotourism. There is an opportunity to begin or expand guided tour services. This research will analyze the demand and willingness to pay for guided river activities – kayaking and pontoon boating – on the Tennessee River in downtown Knoxville. Primary data were collected by 1000 on site flyers connected to an online survey platform. These data were uploaded into …

The Impacts Of Tilled-In Biodegradable Plastic Mulch On Soil Microbial Communities, Corissa L. Martin

Masters Theses

Plastics mulch films are used in agriculture to help increase crop production by regulating soil water retention and soil temperature while also preventing weed growth. Despite these benefits, plastic mulches have led to higher levels of microplastic pollution as weathering occurs. In response to this issue, biodegradable plastic mulches (BDMs) have been introduced to help reduce plastic pollution as they are designed to be tilled into soil after each growing season to continue degradation. Degradation of these mulch films is dependent on climate and, in some areas, complete degradation can take years. Since some biodegradable plastic mulches are made of …

Age Impacts Perineuronal Net Density In The Somatosensory Genital Cortex Independently Of Gonadal Steroid Hormones, Ian D. Warren

Masters Theses

A hallmark of pubertal development is the rise in gonadal hormone secretions and the subsequent onset of sexual behavior. The size of the somatosensory genital cortex increases in response to both this rise in gonadal steroid hormones and sexual experience. However, whether specific markers of brain plasticity are similarly impacted by gonadal hormones during puberty is not known. Perineuronal nets (PNNs) are specialized extracellular matrix structures that unsheathe neurons as they mature, and their maturation coincides with the closure of sensitive periods across several sensory systems. PNNs in somatosensory cortex, as an example, respond to experience-dependent plasticity. Although experience-depended changes …

Establishing And Optimization Of Tissue Culture Work With Erigeron Canadensis, Robert Petursson

Masters Theses

Glyphosate resistance among weed species has been an increasing problem in crop production over the past two decades. Glyphosate resistant Erigeron canadensis (horseweed) has been found on multiple continents and 20 U.S. states. It appears that the resistance is of non-target type, with mechanisms of action that have yet to be elucidated at the gene level. For the first portion of the study, I focused on reproducing the original indirect organogenesis protocol but discovered biotype variability can influence regeneration success. An improved indirect organogenesis method was then developed using the previously published methods that could be used across biotypes. A …

Evaluation Of Forage Nutritive Value And Dry Matter Yield Of Stockpiled Tall Fescue Across Plant Hardiness Zones 7 And 8, Malerie Elizabeth Fancher

Masters Theses

Pastures in Tennessee comprise mainly tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.], a cool-season perennial grass. Tennessee producers feed hay for an average of 143 days per year, there is interest in utilizing stockpiling to extend the grazing season. Although this practice has been proven to reduce hay needs (Freeman et al., 2019), it is vital to maintain up-to-date recommendations using data from across the southeastern US to inform nutritional management decisions. The objective of this study is to determine the nutritive value and dry matter yield of stockpiled tall fescue across plant hardiness zones 7 and 8. Fourteen farms …

Assessing The Impact Of The Tennessee Equine Industry, Olivia Watson

Masters Theses

The Tennessee equine industry is alive and prevalent across the entire state. However, due to the expansiveness of the industry, lack of consistent record keeping, and large discrepancies among reporting agencies, it has proven to be difficult to accurately account for the total impact of the industry in terms of population, demographics, and overall economic impact. The objective of this study was to 1) determine population demographics and economic impact of the equine industry in Tennessee and 2) determine the public perception on the addition of live equine racing within the state. An anonymous, online assessment was developed (March-August 2022; …

It’S All About Fishing: Robert Ellis Jenkins (1940-2023) And His Life Among Freshwater Fishes Of Virginia And The Redhorse Suckers, Eric J. Hilton

Southeastern Fishes Council Proceedings

Robert (Bob) Ellis Jenkins passed away in Salem, Virginia, on Wednesday, July 12, 2023. Bob was born February 9, 1940 in Brooklyn, New York. As a child, Bob took an early interest in natural history, and was a particularly avid fisherman. He attended Roanoke College (Salem, VA) as an undergraduate and entered into a Masters degree program at Virginia Tech (Blacksburg, VA), only to leave before finishing for a position at the NOAA Systematics Lab based at the Smithsonian Institution’s National Museum of Natural History. He eventually became faculty at his alma mater, Roanoke College, where he would spend virtually …

Johne’S Disease In A Pygmy Doe: A Diagnostic Dilemma, Madison Callicott, Kaitlyn Upton, Joseph Smith, Camille Cordero Aponte

Faculty Publications and Other Works -- Large Animal Clinical Sciences

No abstract provided.

Discovery Of An Introduced Florida Flagfish (Jordanella Floridae) Population In Coastal Mississippi, Robert Ellwanger, Samuel E. Hunt, Calvin R. Rezac, Matthew D. Wagner

Southeastern Fishes Council Proceedings

The recent discovery of Jordanella floridae (Florida Flagfish) in Harrison County, Mississippi represents the first known occurrence of the species in the state. Native along the Atlantic and Gulf Coasts of Florida from Jacksonville to Tallahassee, this species has been introduced outside of its range via aquarium introductions. We hypothesize that an aquarium introduction was also the source of the newly discovered population, which has persisted at the location since 2020. Multiple collections of the species have been taken from a small waterbody which has a direct connection to the Tchoutacabouffa River (25mm-47mm TL). While it is unknown if this …

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 …

Advancing Natural White Oak (Quercus Alba.) Reproduction Through A Midstory Removal, Canaan Jeffrey Dugger

Masters Theses

In recent decades, there has been an alarming decline in white oak (Quercus alba.) regeneration and recruitment occurring within eastern forests. Historically, the frequency and the intensity of anthropogenic disturbances was dynamic over the landscape. However, over just the last century a major compositional shift has occurred from this change in disturbance regimes. Eastern forests are now promoting the regeneration of mesic species that obstruct white oaks’ ability to compete successfully and establish in the upper canopy.

The majority of successful white oak regeneration and recruitment is now occurring on the average to more xeric sites. Limited studies …

Management And Investment: Two Pillars Of Automatic Milking Systems Efficiency, Abby N. Mccalmon

Masters Theses

Fetch cows, dairy cattle that do not voluntarily enter automated milking systems (AMS), increase labor costs, and decrease efficiency. The objective of this study was to describe fetch cows based on fetch lists and herd-management software data. This study was conducted on a commercial dairy farm (n = 510 cows) using 8 AMS from October 1, 2021, to May 10, 2022. Data were collected via PCDART, DairyComp, and a proprietary interface. Two fetch categories by cow, EverFetch (EF) and NeverFetch (NF), and three status groups by cow by day, True Fetch (on fetch list …