Digital Commons Network^™

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 …

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 …

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 …

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; …

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 …

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 …

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 …

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 …

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 …

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 …

Using Novel Phenotypes To Understand And Predict Fertility In Beef Cows, Cassidy Catrett

Masters Theses

Reproduction plays a major role in the production efficiency of livestock species. However, cow-centric reproductive traits are lowly heritable and are not expressed until later in an animal’s lifetime, making phenotypic selection ineffective at generating genetic gain. We can generate genetic progress by focusing selection on the genetic component of reproductive traits using Expected Progeny Differences (EPDs). We used the American Simmental Association’s performance and Total Herd Enrollment data, made up of 533,155 calving records from 303,158 females (132,403 cows and 170,755 heifers), 33,732 of which are genotyped, to develop two continuous and two discrete phenotypes focused on quantifying early …

Development Of Domestic Oleochemicals For Coating Applications, Caleb M. Metzcar

Masters Theses

The overall objective of the present work is to explore new applications of soybean oil based oleochemicals. Two main applications are developed; one using soybean oil, acrylic acid, and nonthermal plasma (NTP) treatment to dye para-aramids with cationic and non-ionic pigments, the other using fatty acids to synthesize waxes with bound quaternary ammonium compounds (QAC), an antimicrobial functional group, for fruit and vegetable postharvest coating. The color strength of the dyed fabric was quantified and the effect of the dyeing on material strength was evaluated to identify the optimal treatment condition. Antimicrobial waxes have been successfully developed that some structures …

Pregnancy Influences On The Rumen Environment Of Angus Heifers Differing In Feed Efficiency, Miranda Gabrielle Martin

Masters Theses

With an expected increase in population by 2050, the demand for more animal protein will increase. To improve the sustainability of US cattle production, producers and researchers have historically focused on improving the feed efficiency of steers, producing a more marketable beef product. However, without a successful pregnancy, there would be no marketable animal to feed. The objective of this study was to examine the physiological changes that occur during pregnancy and their impact on the rumen microbial communities and the correlation to feed efficiency status in Angus heifers. Utilizing 17 cannulated Angus heifers, feed efficiency data was previously collected …

A Watershed Prioritization Model For Community-Centered Riparian Forest Restoration In Tennessee, Madison Johnson

Masters Theses

Riparian forests are unique ecosystems that act as transitional areas between land and water that are a vital part of a healthy and functional stream ecosystem. Due to the rapidly changing landscape, riparian forests are increasingly threatened by urban development, agriculture, and invasive species, which contributes to a trend of degrading water quality in Tennessee. To address declining riparian forest quality in the face of land-use changes, the purpose of this study was to develop a simple watershed prioritization model that identifies areas that are highly susceptible to poor water quality, and where riparian plantings would be most beneficial. This …

Multiphysics Modeling To Understand Microwave-Food Interactions In A Multi-Port Solid-State Microwave System., Kartik Verma

Masters Theses

Multiphysics modeling plays a crucial role in understanding the complexities of microwave-food interactions, especially in multi-port solid-state microwave systems where microwave parameters can be precisely and dynamically controlled. However, previous models using simplistic or manually measured oven geometries face challenges in accurately simulating the microwave heating process. This study first developed a robust 3-D scanning approach to capture precise geometric details of the oven cavity, incorporating them into multiphysics modeling for solid-state microwave heating. Furthermore, a quantitative validation approach was also developed to characterize modeling accuracy against experimental results. The results showed that multiphysics modeling with 3-D scanned geometry demonstrated …

Black Bear Population Health Monitoring In The Southeast, Kathleen Elizabeth Riese

Masters Theses

Recent growth of the American black bear (Ursus americanus) population in the southeast raises concerns about the potential spread of density-dependent diseases among bears, particularly sarcoptic mange. However, research on the health of bears in this area is limited. We analyzed samples from 169 bears in the region. We performed Knotts tests, skin scrapes, fecal floats; Canine adenovirus (CAV), canine parvovirus (CPV), canine distemper virus (CDV), and Toxoplasma gondii serology, Trypanosoma, Rickettsia rickettsii, and apicomplexan PCR, and identified ecto- and endoparasites found grossly or histologically. We found that 69% (63 of 91) had microfilaria; genetic analysis identified …

Communication Distance Predicts Territory Size For An Urban Songbird, Ruth A. Simberloff

Masters Theses

Many studies demonstrate that urban noise interferes with animal communication by masking acoustic signals such as birdsong, but the functional consequences of impaired communication are still not well understood. Although many bird species sing at higher amplitude in noise pollution, communication distance is still reduced in noisy urban soundscapes. Song is a long-distance signal that functions to attract a mate and defend a territory, so a reduction in communication distance could negatively influence a male’s reproductive or competitive success. Reduced territorial success could manifest as more frequent territorial intrusions, reduced territory quality, or reduced territory size. We examined the relationship …

Analyzing Youth Engagement And Gender Roles In The Groundnut Value Chain In Uganda Using The Photovoice Research Methodology, Annie Faye Carter

Masters Theses

In regions of East Africa, groundnut (Arachis hypogaea L.) is cultivated as a common cash crop in areas of food insecurity and agricultural-dependent communities. Groundnut, also known as peanut, is a legume with a variety of important uses. This crop is especially popular with small-scale farmers and youth, who seek to harvest a crop which is affordable. As an expected 440 million young people enter the global labor market by 2030, those living in rural areas are at a disadvantage when searching for job opportunities. In Africa, this rural-urban divide has impacted the economic sector and the activities …

Characterization Of Key Odorants In Cumberland Rosemary, Conradina Verticillata, Claire Mackenzie Gorman

Masters Theses

Conradina verticillata Jennison, commonly known as Cumberland Rosemary, is a threatened plant from the mint family Lamiaceae. This species is a flowering, perennial shrub found in only a few counties of Kentucky and Tennessee. Cumberland Rosemary possesses a unique aroma profile; however, the odorants responsible for its aroma have not been previously identified. In this study, a total of 32 odorants were identified in Cumberland Rosemary using gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Odorant flavor dilution (FD) factors were determined through the application of aroma extract dilution analysis (AEDA). Seven odorants with FD factors ≥ [greater than or …

An Analysis Of Dairy Farm Financial Efficiency And Price Expectations In Seedstock Bull Markets, Seth H. Ingram

Masters Theses

The first thesis chapter employs two single-stage data envelopment analysis (DEA) models under varying returns to scale assumptions to provide technical efficiency estimates for 26 dairy farms in Tennessee, Kentucky, and North Carolina participating in the UT Dairy Gauge program. These analyses reveal how efficiently farms utilize inputs (cows, feed, labor, forage) to generate farm income relative to other sample farms. Under the assumption of constant returns to scale (CRS) 7 farms are estimated to be technically efficient, while 13 farms display comparative efficiency under an assumption of variable returns to scale (VRS). No …

Exploring Alternative Methodologies To Estimate By-Species Sawlog Volume In The Southeastern United States, Tara Skiba

Masters Theses

The Forest Inventory and Analysis (FIA) conducts Timber Products Output (TPO) studies to assess timber resource use across the United States. The TPO studies gather information through surveys of primary wood processing facilities to quantify the utilization of roundwood by geographic location, tree species, and timber product type. However, not all responding mills provide information on tree species utilized. As a result, a portion of the reported volume falls into the “unknown/unclassified” softwood or hardwood category, which account for up to 74% of total hardwood/softwood southern volumes in some cases. In addition, the detailed species in the TPO survey forms …

Characterization Of Arabidopsis Eukaryotic Translation Initiation Factor 2Α (Eif2Α) Mutants, Mark Edens

Masters Theses

Plants are stationary organisms that are charged with overcoming a multitude of biotic and abiotic stresses. The eukaryotic translation initiation factor 2 (eIF2) is responsible for charging the P-site of the forming 80S ribosome with the initiator methionyl-tRNA. Thus, eIF2 is a protein of utmost consequence in the growth and development of organisms. The eIF2 protein is also a mediator of global translational regulation in the eukaryotic integrated stress response (ISR), where the α-subunit is phosphorylated by protein kinases, such as the kinase GCN2. Here, five eIF2α allele mutants in Arabidopsis were found to be deleterious to plant growth, development, …

Brown People, Green Spaces: Colonial Imaginaries And The Whiteness Of Nature, Jeffrey Michael Desalu

Masters Theses

For several years, conversations about the absence of racial and ethnic diversity in ecology and evolutionary biology (EEB) and the conservation movement have been growing in scope. Critics argue that the overwhelmingly white demography of EEB departments and conservation organizations deprive both of a necessary diversity of perspective and, more importantly, deprive people of color and other minoritized groups of a voice in the study of and advocacy for their lived environments. Here, I situate the current conversations in historical context, arguing that the current lack of diversity is in part a reflection of the material and ideological bases for …

Food Insecurity And The Value Of Best If Used By Dates, Lun Luo

Masters Theses

Food insecurity affected 10.2% of United States households in 2021. While food pantries offer free food to households in need, prior research suggests that stigma may prevent households from utilizing this valuable resource. The purpose of this study is to investigate a potential additional barrier to food pantry used posed by the near-to best if used by dates (BUBD) commonly found on foods donated to foodbanks. If food pantry users perceive this food to be less valuable, even though it is still safe for consumption, they may not be willing to accept the food even when it is free. Data …

Two Essays On International Beef And Poultry Consumer Demand, Bhishma Raj Dahal

Masters Theses

This study examines meat preferences in China and Rwanda. In China, we analyzed the factors associated with frequent beef purchasing decisions. Using a survey of 560 consumers in Beijing, Shanghai, and Guangzhou, we found that nearly 50% of respondents purchased beef at least 2-3 times a week. Those who purchased specific cuts of beef from wet markets and supermarkets and considered the country of origin and growth hormone-free products important were likely to buy beef more often. The frequency of consumption was also higher for younger respondents with higher wages and those who prioritized price and premium quality. Our findings …

Impact Of Cover Crop Species Diversity On Soil Nutrient Availability And Crop Productivity, Amanda Kramer

Masters Theses

Cover crops provide multiple environmental benefits that improve both soil and water quality; however, farmers only utilize them on approximately 5% of harvested U.S. cropland. Low adoption rates are attributed to yield impact concerns, seed and planting costs, and lack of advocacy. This study, which began in October 2019, assessed the effects of nitrogen rate and cover crop diversity on weed biomass, soil coverage, in-situ residue decomposition, soil nitrogen and phosphorus availability, and cash crop yield to better understand the costs and benefits of cover crop adoption at two locations in Tennessee (Milan and Spring Hill). Treatments were replicated 4 …

Rumen Biogeographical Regions And Their Impact On Microbial And Metabolome Variation, Macey P. Soltis

Masters Theses

The rumen microbiome is a complex microbial network critical to the health and nutrition of its host, due to their inherent ability to convert low-quality feedstuffs into energy. In rumen microbiome studies, the ventral sac is sampled from due to ease of access and repeatability. However, anatomical musculature demarcates the rumen into five sacs which may support distinct microbial communities. The distinction among the microbes may generate functional variation among the rumen microbiome, thus, specialized tasks within different sacs. The objective of this study was to determine the rumen liquid metabolome and epimural, planktonic, and fiber-adherent bacterial communities among each …

Predicting Immunization Status At Arrival In Tennessee Stocker Calves, Claire E. Hunkler

Masters Theses

Bovine respiratory disease is a multifaceted disease with agent, host, and environmental factors. Stocker calves are at high risk of contracting the disease through many stressors like weaning, transportation, commingling, etc. The purpose of this project was to test if externally observed physical characteristics of calves on arrival at a stocker facility can be used to predict calfhood vaccination status determined based on antibody titer levels. Knowledge of highly correlated characteristics could allow stocker operators to reduce the occurrence of BRD through targeted management strategies, thus lowering morbidity, mortality, and treatment costs. Ear notches, blood, and visual characteristics were collected …