Life Sciences Commons^™

Winter Roost Selection Of Eastern Red Bats And Impacts Of Non-Growing Season Prescribed Fire On Foraging Activity Of Forest Roosting Bats In Tennessee, Ashley D. Epstein

Masters Theses

With an increase in wind energy development and continued deforestation and habitat degradation, eastern red bats (Lasiurus borealis; LABO) and other migratory foliage roosting bats (hoary bat [Lasiurus cinereus; LACI], silver-haired bat [Lasionycteris noctivagans; LANO]) are at risk of severe population declines, potentially leading to the need for protection under the Endangered Species Act. While studies have been done examining the ecology of these species, there is still a lack of research on winter roosting and foraging behaviors. This research aims to fill some of those knowledge gaps by 1) Examining roost use (i.e., trees vs. litter) …

Aquatic Transitions And Interspecific Relationships In Fissidens Mosses, Julia R. Butler

Masters Theses

Embryophytes have undergone numerous re-invasions to aquatic habitats, impacting their morphological evolution. Despite the prominence of these transitions, their phylogenetic implications and morphological adaptations are just beginning to be investigated, especially as molecular methodologies become more accessible. We investigate these phenomena using the genus Fissidens, a diverse group of mosses encompassing both terrestrial and aquatic species. Our study integrates phylogenetic methods with morphological analyses to elucidate the evolutionary patterns within Fissidens and explore correlations between habitat transitions and morphological traits. Through extensive taxon sampling from herbarium specimens, DNA extraction, and sequencing, we construct robust phylogenetic trees using concatenated and …

Designing A Serious Game To Simulate Ecological Processes On A Post-Eruption Mount St. Helens Landscape, Parker Maynard

Masters Theses

Developing strategies to successfully manage landscapes to meet ecological, economic, and social goals is an increasing concern in a world experiencing anthropogenic global changes. The 1980 eruption of Mount St. Helens in Washington state provided a major learning opportunity in managing resource effectively after a major disturbance. This information is explored through Resilience: After The Eruption: a serious game developed as part of this thesis that synthesizes research about ecological recovery and resource management following the eruption of Mount St. Helens. The digital game allows players to take on the role of four different stakeholders performing landscape-based operations while …

Evaluation Of Regression Methods And Competition Indices In Characterizing Height-Diameter Relationships For Temperate And Pantropical Tree Species, Sakar Jha

Masters Theses

Height-diameter relationship models, denoted as H-D models, have important applications in sustainable forest management which include studying the vertical structure of a forest stand, understanding the habitat heterogeneity for wildlife niches, analyzing the growth rate pattern for making decisions regarding silvicultural treatments. Compared to monocultures, characterizing allometric relationships for uneven-aged, mixed-species forests, especially tropical forests, is more challenging and has historically received less attention. Modelling how the competitive interactions between trees of varying sizes and multiple species affects these relationships adds a high degree of complexity. In this study, five regression methods and five distance-independent competition indices were evaluated for …

Agrobacterium-Mediated Transformation Of Hemp (Cannabis Sativa L.)., Carthel Tyler Newton

Masters Theses

Agrobacterium­-mediated transformation has long been utilized as a method of producing stable, transgenic plants. This project describes an attempt to develop a system of producing stably transformed hemp (C. sativa (L.)) plants. Because of its recalcitrance to in vitro tissue culture and regeneration, transformation studies of hemp have been severely limited. In this study, I combined media components that have been shown to improve tissue culture health and regeneration. Additionally, I used hemp cultivars and explant sources that have been reported to function well in in vitro systems. The results showed that the improved media components did not …

Two Essays On The Economics Of Global Food Demand, Savant Nzayiramya

Masters Theses

This study provides an understanding of global consumption patterns across major spending and food categories using data from the 2017 International Comparison Program (ICP). The first chapter examines the demand for food and non-food items across 162 countries using the Quadratic Almost Ideal Demand System (QUAIDS) to estimate demand for nine spending categories: food, clothing, furnishings, transport, housing, health, recreation, education, and miscellaneous. We calculated expenditure, own-price, cross-price elasticities, and marginal shares across these spending categories and performed a welfare analysis to determine the compensation required to maintain the same utility following inflationary periods. The findings indicate that food is …

Enhanced Efficiency Nitrogen Fertilizer As Tool To Control Nitrogen Loss In Row Crop Production, Samuel Kudzo Okai

Masters Theses

The efficiency of urea-based fertilizers is substantially reduced through nitrogen (N) losses via ammonia volatilization. Soil pH, clay content, soil organic matter (SOM), and field capacity can affect ammonia loss. Incubation experiments were conducted on eight soils using a controlled environment system to study the effects of soil properties on ammonia volatilization from urea and urea ammonium nitrate (UAN) applied at 134.5 kg N/ha. Each experiment was set up as a randomized complete block design with four replicates. Ammonia loss was measured on 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, and 16 DAF (days after N application). …

The Role Of Hypoxia Inducible Factor-1 Alpha (Hif-1⍺) In Human Coronavirus Oc43 Infection, Olivia Faith Riffey

Masters Theses

The importance of altering host cell metabolism for promoting infection and propagation of coronaviruses highlights the intricate play between viruses and the cells they infect (1). Upregulation of the glycolytic pathway in host cells infected with coronaviruses was observed in single-cell RNAseq, although the mechanism(s) that mediate this effect are still being investigated(2). Hypoxia-inducible factor-1 alpha (HIF-1⍺) is a transcription factor that regulates many glycolytic enzymes. Recent studies have identified SARS-CoV-2 upregulation of HIF-1⍺, which suggests it may have an important role in virus production (3, 4). However, the exact role and physiological relevance of HIF-1⍺ during viral infection is …

Identification, Creation, And Characterization Of Bio-Based Antifreeze Agents, Joshua Samuel Saad

Masters Theses

Ice recrystallization is a key problem leading to quality deterioration of frozen foods and biomedical materials. Molecules possessing ice recrystallization inhibition (IRI) activity can control ice crystal size after freezing, reducing the degree of freezing-induced damage. While these IRI active molecules have shown promise in maintaining the quality of frozen foods, their slow discovery, limited creation strategies, and lack of mechanistic understanding limit their hypothesis-driven design. In this work, we address these above-stated needs required for the streamlined implementation of these materials into frozen systems by the creation of a machine-learning-based IRI screening method, the development of a new IRI …

Pollen-Specific Expression Of Ecori Restriction Endonuclease For Bioconfinement In Panicum Virgatum L., Jessica Nicole Stockdale

Masters Theses

The dispersal of pollen from genetically engineered (GE) crops can lead to unintended transgene flow, especially in wind-pollinated and obligate-outcrossing species such as switchgrass (Panicum virgatum L.). Various bioconfinement approaches have been studied for their potential to eliminate transgene flow from GE crops including selective male sterility, which aims to inhibit the germination of transgenic pollen grains. In this study, pollen-specific promoters controlling the expression of the EcoRI endonuclease, interrupted by a catalase intron, was evaluated for its efficacy to produce sterile pollen. The TaPSG719, PvPS1, Osg6B, OsRTS, and Zm13 promoters were assessed for pollen-specific expression patterns, none …

Defining A Haplotype Encompassing The Lcorl-Ncapg Locus Associated With Increased Lean Growth In Beef Cattle, Leif E. Majeres

Masters Theses

Numerous studies have shown genetic variation at the LCORL-NCAPG locus is strongly associated with growth traits in beef cattle. However, a causative molecular variant has yet to be identified. To define all possible candidate variants, 34 Charolais-sired calves were whole genome sequenced including 17 homozygous for a long-range haplotype associated with increased growth (QQ), and 17 homozygous for potential ancestral haplotypes for this region (qq). The Q haplotype was refined to an 814-kb region between chr6:37,199,897-38,014,080 and contained 218 variants not found in qq individuals. These variants include an insertion in an intron of NCAPG, …

Current Perceptions, Use, And Field Implementation Of Precision Poultry Farming Technologies, Tanner Alan Thornton

Masters Theses

The agricultural sector is experiencing a profound shift driven by technological advancements and the imperative for sustainable food production. Within this context, Precision Livestock Farming (PLF) has emerged as a transformative approach to animal management (Berckmans, 2017), leveraging data-driven decision-making, automation, and monitoring systems to enhance livestock production efficiency while minimizing resource usage and environmental impact. This thesis delves into a comprehensive examination of PLF as applied to broiler farming, particularly focusing on current usage perceptions, needs, and its potential to revolutionize the poultry industry.

Research in Precision Livestock Farming has steadily increased since 2000, with a growing percentage 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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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; …

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 …

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 …

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 …

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 …

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 …

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 …

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 …