Digital Commons Network^™

Investigation Of Host Responses Upon Infection Of Distinct Toxoplasma Strains, Rachel Devonne Hill

Doctoral Dissertations

Toxoplasma gondii is the causative agent of Toxoplasmosis in human and animals. T. gondii isolates are highly diverse. Hundreds of genotypes have been identified, but only three clonal lineages, namely Type I, II and III are prevalent worldwide. In mouse model, T. gondii strains can be divided into three groups based on their virulence, including the virulent (LD₁₀₀=1), the intermediately virulent (LD₅₀ = 10³-10⁴) and the non virulent (LD₅₀ > 10⁵). The clonal Type I, II and III T. gondii strains belong to these three groups, respectively. Epidemiologic studies suggest the …

The Role Of A Glycosyltransferase, St6gal I In Regulating Viral Specific T And B Cell Responses, Junwei Zeng

Doctoral Dissertations

Glycosylation is one of the most abundant post-translational modifications of proteins. Glycoproteins participate in virtually all aspects of cellular functions. ST6Gal I is a glycosyltransferase highly expressed by B and T cells. Here, we interrogated the role of ST6Gal I in viral specific B and T cell immune responses, as well as examined how loss of this enzyme impacted viral pathogenesis.

First, to understand how loss of ST6Gal I expression impacted viral specific humoral responses, we infected ST6Gal I^-/- mice with influenza virus. We discovered that loss of ST6Gal I expression results in both reduced influenza specific antibodies levels …

Assessing The Efficiency Of Phenotypic And Molecular Genotype Selection Methods For Complex Traits In Soybean, Catherine Nyaguthii Nyinyi

Doctoral Dissertations

Soybean [Glycine max (L.) Merrill] is an important source of protein and oil for both nutritional and industrial applications. Increasing seed yield and protein concentration is the main goal of many soybean breeders to meet market demands. Soybean breeders have occasionally succeeded in producing high yielding cultivars with increased protein content using conventional means despite the negative correlation that exists between these two traits. The efficiency of breeding for seed yield and protein concentration improvement in soybean could be increased using marker assisted selection (MAS) breeding strategies to select genotypes containing favorable alleles for faster cultivar development. The objective …

Nano-Dispersing Lipophilic Antimicrobials For Improved Food Safety, Bhavini Dipak Shah

Doctoral Dissertations

Naturally occurring food antimicrobials such as plant essential oils are receiving tremendous interest as intervention systems to enhance microbiological safety and quality. Poor water solubility of essential oils makes it difficult to incorporate them in foods, impacting visual appearance, antimicrobial effectiveness, and possibly organoleptic properties. Engineered nanoscale delivery systems can principally solve these challenges, but those based on low-cost food ingredients and inexpensive and scalable processes are currently scarce. This dissertation presents a simple and scalable two-step technology to prepare nano-delivery systems. The first encapsulation step, based on emulsion-evaporation, involves preparing emulsions composed of an oil phase with thymol or …

Aqueous Micellar Gels Of Multiresponsive Hydrophilic Aba Linear Triblock Copolymers, Jeremiah Wallace Woodcock

Doctoral Dissertations

This dissertation presents the synthesis of a series of well-defined multiresponsive hydrophilic ABA linear triblock copolymers and the study of their aqueous micellar gels. By incorporating a small amount of stimuli-responsive groups into thermosensitive outer blocks of ABA triblock copolymers, the lower critical solution temperatures (LCST) of thermosensitive blocks can be modified by external stimuli. Consequently, the sol-gel transition temperatures (T_sol-gel) of their aqueous solutions can be altered.

Chapter 1 describes the synthesis and solution behavior of a series of thermo- and light-sensitive triblock copolymers, poly(ethoxytri(ethylene glycol) acrylate-co-o-nitrobenzyl acrylate)-b-poly(ethylene oxide)-b …

Comparing The Midgut Regenerative Responses In Bacillus Thuringiensis-Susceptible And Resistant Heliothis Virescens Larvae, Anais Severiana Castagnola

Doctoral Dissertations

The crystal (Cry) toxins from Bacillus thuringiensis (Bt) display high specificity and toxicity against relevant insect pests and the use of Bt-based products continues to contribute to insect pest management. To protect this investment, further its potential, and investigate possible unintended effects, various research questions have been proposed. One issue related to Bt usage is the evolution of pest resistance to Bt toxins. The midgut epithelium is targeted by Cry toxins killing enterocytes, facilitating invasion of the hemocoel, leading to septicemia and mortality. While resistance may emerge from alterations to these steps, most research efforts have been focused on reduced …

Production And Roles Of Volatile Secondary Metabolites In Interactions Of The Host Plant Tomato (Solanum Lycopersicum L.) With Other Organisms At Multi-Trophic Levels., Gitika Shrivastava

Doctoral Dissertations

Tomato (Solanum lycopersicum L.) produces an array of volatile secondary metabolites that act as constitutive and induced defenses against a variety of insect pests and diseases. We studied the effect of beneficial microorganisms, an arbuscular mycorrhiza fungus (AM), Glomus intraradices, an entomopathogenic fungus (Bb), Beauveria bassiana and a combination of both (AM+Bb), as well as, pests, such as rootknot nematode (RKN) (Meloidogyne incognita) and beet armyworm (BAW) (Spodoptera exiguae H.) on the production of volatile compounds in the leaves and roots of tomato. Benzyl alcohol, 3-hexenoic acid, total other compounds and β-myrcene were significantly increased ( …

Suppression Of Chronically Induced Breast Carcinogenesis And Role Of Mesenchymal Stem-Like Cells, Kusum Rathore

Doctoral Dissertations

Sporadic breast cancers are mainly attributable to long-term exposure to environmental factors, via a multi-year, multi-step, and multi-path process of tumorigenesis involving cumulative genetic and epigenetic alterations in the chronic carcinogenesis of breast cells from a non-cancerous stage to precancerous and cancerous stages. Epidemiologic and experimental studies have suggested that various dietary compounds like green tea and grape seed may be used as preventive agents for breast cancer control. In this research, I have developed a cellular model that mimics breast cell carcinogenesis chronically induced by cumulative exposures to low doses of environmental carcinogens. I used the chronic carcinogenesis model …

Characterization Of The Human Host Gut Microbiome With An Integrated Genomics / Proteomics Approach, Alison Russell Erickson

Doctoral Dissertations

The new field of ‘omics’ has spawned the development of metaproteomics, an approach that has the ability to identify and decipher the metabolic functions of a proteome derived from a microbial community that is largely uncultivable. With the development and availabilities of high throughput proteomics, high performance liquid chromatography coupled to mass spectrometry (MS) has been leading the field for metaproteomics. MS-based metaproteomics has been successful in its’ investigations of complex microbial communities from soils to the human body.

Like the environment, the human body is host to a multitude of microorganisms that reside within the skin, oral cavity, vagina, …

Immunity And Immunopathology In Acute Viral Infections, Shalini Sharma

Doctoral Dissertations

Herpetic stromal keratitis (HSK) is an immunopathological and tissue destructive corneal lesion caused by herpes simplex virus (HSV) infection, which induces an intense inflammatory response and finally leads to blindness. Accumulating evidence using the murine model has shown that Th-1 phenotype CD4⁺ T cells orchestrating the inflammation mainly contribute to the immunopathological reaction in HSV-1 infected cornea. Initially various innate immune cells recruit and produce numerous inflammatory and angiogenic molecules into the corneal stroma those in turn drive the corneal immunopathology.

While the basic principles of immunity to the influenza A viruses (IAV) are probably similar for all vertebrates, …

An Evaluation Of Disturbance-Induced Nutrient Changes And Climate Responses Of Loblolly Pine Xylem, Rebecca Lynne Stratton

Doctoral Dissertations

Dendrochronological techniques are currently limited to the identification of visible fire scars. However, through the development of new dendrochemical techniques, the potential exists to provide insight into a broader array of pyric ecosystems. In addition, the ability to identify historic climate-growth responses provides a better understanding of the conditions under which historic fire regimes occurred.

This study provides the groundwork for the identification of a dendrochemical nutrient fire signature in xylem and identifies the climate-radial growth responses of loblolly pine (Pinus taeda L.) on five sites in the Piedmont of South Carolina. Changes in N, P, K, Ca, Mg, …

Development And Application Of Liquid Chromatography-Tandem Mass Spectrometry Methods To The Understanding Of Metabolism And Cell-Cell Signaling In Several Biological Systems, Jessica Renee Gooding

Doctoral Dissertations

Liquid chromatography tandem mass spectrometry has become a powerful tool for investigating biological systems. Herein we describe the development of both isotope dilution mass spectrometry methods and targeted metabolomics methods for the study of metabolic and cell-cell signaling applications.

A putative yeast enzyme was characterized by discovery metabolite profiling, kinetic flux profiling, transcriptomics and structural biology. These experiments demonstrated that the enzyme shb17 was a sedoheptulose bisphosphatase that provides a thermodynamically dedicated step towards riboneogenesis, leading to the redefinition of the canonical pentose phosphate pathway.

An extension of metabolic profiling and kinetic flux profiling methods was developed for a set …

The Utilization Of Mouse Models To Study Gene Functions: The Role Of Foxn3 And Chd2 In Murine Development And Cancer, George Azaz Samaan

Doctoral Dissertations

Murine model organisms are an essential tool in the scientific community quest to decipher the molecular etiology of human diseases. Currently, several methods are used to induce or reproduce human diseases in mouse models using advanced genetic engineering techniques to mutate the wild-type genes. We utilized the Baygenomics gene-trap method to study the effects of two mammalian genes: FOXN3 and CHD2. The Forkhead Box (FOX) family of transcription factors shares a common DNA-binding domain and has been associated with organ development, differentiation, cell growth and proliferation, and cancer. Meanwhile, the CHD (Chromodomain helicase DNA binding protein) family of proteins is …

Riparian Ecosystem Response To Hemlock Woolly Adelgid (Adelges Tsugae) Induced Eastern Hemlock (Tsuga Canadensis) Mortality In The Great Smoky Mountains National Park, Usa, Misty Dawn Huddleston

Doctoral Dissertations

An invasive insect, hemlock woolly adelgid (HWA), has initiated widespread hemlock decline and mortality in the Great Smoky Mountains National Park (GSMNP). Riparian hemlock mortality impacts on vegetative and aquatic systems of first-order, headwater streams were evaluated. Reference sites for this study were representative of the best available conditions within the GSMNP, with initial stages of HWA presence. Impacted sites were defined as areas with over 90 percent hemlock mortality. Impacted streams had decreased canopy coverage and increased light availability. Residual red maple, yellow birch, and sweet birch capitalized on the loss of hemlock, with increases in relative basal area …

Interaction Of A G Protein-Coupled Receptor (Ste2p) Of Saccharomyces Cerevisiae With Its Ligand And Its G-Protein Alpha Subunit, Li-Yin Huang

Doctoral Dissertations

The G protein-coupled receptor (GPCR) family is composed of hundreds of members and is expressed in eukaryotes. Each GPCR has seven transmembrane domains and is in charge of sensing changes from the environment, transducing signals, and activating a series of biological responses. The signal transduction pathway of the receptor starts from sensing outside signal and then activates G proteins. This signaling requires a tight control for activation without which impaired cellular function leads to pathology. We have used the pheromone alpha-factor receptor (Ste2p) of the yeast Saccharomyces cerevisiae as a model system to understand ligand binding, receptor activation, and G …

Multiple Responses By Cerulean Warblers To Experimental Forest Disturbance In The Appalachian Mountains, Than James Boves

Doctoral Dissertations

The Cerulean Warbler (Setophaga cerulea) is a mature forest obligate and one of the fastest declining songbird species in the United States. This decline may be related to a lack of disturbance within contemporary forests; however, the consequences of disturbance on the species have not been rigorously evaluated. Thus, we assessed multiple responses by Cerulean Warblers to a range of experimental forest disturbances across the core of their breeding range in the Appalachian Mountains. We quantified individual and population responses to these manipulations, and assessed the potential consequences of disturbance on the sexual signaling system. Male ceruleans were …

Functional Genomic Studies Of Soybean Defenses Against Pests And Soybean Meal Improvement, Jingyu (Lynn) Lin

Doctoral Dissertations

Soybean [Glycine max (L.) Merr.] is an important crop worldwide. It has been widely consumed for protein, oil and other soy products. To develop soybean cultivars with greater resistance against pests and improved meal quality, it is important to elucidate the molecular bases of these traits. This dissertation aims to investigate the biochemical and biological functions of soybean genes from four gene families, which are hypothesized to be associated with soybean defense against pests and soybean meal quality. There are three specific objectives in this dissertation. The first one is to determine the function of components in the salicylic …

Physical And Chemical Stability Of Fish Oil-In-Water Emulsions Prepared With Preheated Wpi And Maltodextrins, Sutida Watthanapimol

Masters Theses

Fish oil has abundant polyunsaturated fatty acids that are important to health but are oxidized easily during shelf-life storage. Engineering oil/water interfaces of emulsions has been studied extensively, but practical technologies are still demanded by the food industry. Whey proteins aggregate during heating, and the preheated whey protein/aggregate may increase the robustness of interfaces and in turn improve oxidative and physical stability of fish oil emulsions. In this study, whey protein isolate (WPI) solutions were prepared at 0-100 mM NaCl and pH 7.0 and preheated at 85 °C for 5-30 min. The preheated WPI was used to prepare fish oil …

Integrated Strategies For Controlling Warm-Season Turfgrass Weeds, Matthew Thomas Elmore

Masters Theses

Herbicidal inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPPD) such as mesotrione, topramezone and tembotrione were evaluated in greenhouse experiments for activity against bermudagrass. While topramezone and tembotrione exhibited greater activity than mesotrione, none of these herbicides provided acceptable bermudagrass control. These herbicides reduced leaf tissue chlorophyll and carotenoid pigment concentrations in bermudagrass. Changes in turfgrass pigmentation were quantified using HPLC analogy as well as evaluations of visual bleaching and measurements of chlorophyll fluorescence yield (F_v/F_m). Results indicated that these more expeditious methods of evaluating HPPD-inhibiting herbicide activity (visual evaluations and F_v/F_m) cannot be used …

Getting Heavy: An Exploration Into The Effects Of D2o And High Hydrostatic Pressure On R67 Dihydrofolate Reductase, Mary Jane Timson

Masters Theses

Chromosomal dihydrofolate reductase (DHFR) enzymatically reduces dihydrofolate (DHF) to tetrahydrofolate (THF) using NADPH as a cofactor. R67 DHFR is an R-plasmid encoded enzyme that confers resistance to trimethoprim (TMP), an antibacterial drug. It shares no structural homology with TMP targeted, chromosomal DHFRs.

Previous osmolyte studies in our lab have indicated that DHF binding to R67 DHFR is accompanied by water uptake and NADPH binding is accompanied by water release. These data suggest that water plays a role in balancing the binding affinity. This may happen as R67 DHFR has a generalized binding surface and may need differential water effects to …

Bee Visitation To Crops And Other Flowers Planted As Bee Food, Michael Edward Wilson

Masters Theses

Farms that require insect pollination and reside in diverse landscapes benefit from pollination by native bees. However, populations of native bees and honey bees are generally in decline and this threatens food production. Documentation of crop pollination as an ecosystem service is needed to identify potential impacts from declining bee populations. This study identifies communities of bees providing pollination and how they vary across different crops and environmental conditions. Managing landscapes to provide additional food sources for bees may improve the health of wild and managed bees. This study also evaluated the attractiveness of bees to selected species of plants …

Impact Of Switchgrass Bioenergy Feedstock Production On Soil Carbon Dioxide Flux And Below Ground Soil Organic Carbon Storage In East Tennessee, Leah Denise Soro

Masters Theses

Bioenergy production from switchgrass has shown promise in restoring degraded soils and helping to mitigate greenhouse gas (GHG) emissions. CO₂ loss and C-sequestration in soils are important topics for research to better understand the environmental impacts of bioenergy crops. The need for more thorough research of the carbon cycle in soils used for bioenergy production precipitated the primary interest of this study. The specific objectives of this study were 1) to measure SOC under switchgrass production in order to predict storage of carbon in soils based on previous cropping history, land management, soil physical characteristics, and time; and to …

An Evaluation Of Population Estimators And Forage Availability And Nutritional Quality For White-Tailed Deer In Tennessee, Jared Tyler Beaver

Masters Theses

Given the white-tailed deer’s (Odocoileus virginianus; deer) popularity and potentially negative impact on forested systems; Arnold Air Force Base (AAFB) in Tullahoma, Tennessee, USA has made minimizing negative deer impacts on biodiversity a priority. To address these management issues, I initiated a study on AAFB to investigate deer survey techniques and the effects of deer density on forage availability across vegetative communities.

Current use of infrared-triggered cameras (camera) for estimating deer populations does not provide a measure of precision critical for density estimation. I conducted a camera survey for deer in Wildlife Management Area (WMA) Units 1 and …

Plant Genotype, Not Nutrients, Shape Aphid Population Dynamics, Heather E. Tran, Lara Souza, Nathan J. Sanders, Aimee T. Classen

Chancellor’s Honors Program Projects

No abstract provided.

Localization Of Sources Producing Substrate-Borne Vibrations By The Fiddler Crab, Rachel Keiper

Chancellor’s Honors Program Projects

No abstract provided.

Eat The Rainbow! An Evaluation Of A Short-Term Fruit And Vegetable Nutrition Education Intervention For Elementary School Children, Elizabeth Diane Miller

Masters Theses

Objective: To test differences on mean fruit and vegetable (FV) eaten, liking, preference, and self-efficacy scores among 3 modes of nutrition education intervention after a 3-week intervention.

Design: Convenience sample, pre- and post-test, quasi-experimental design.

Setting: Three elementary schools in a rural Eastern Tennessee County.

Participants: Participants were 160 3^rd-5^th graders.

Interventions: Three study schools: experiential (nutrition education, taste tests, and learning activity), conventional (nutrition education and learning activity), and control (learning activity).

Main Outcome Measures: Changes in pre- to post-intervention mean FV eaten, liking, preference, and self-efficacy scores.

Analysis: Mixed model ANOVA to compare the mean …

Factors Related To Nest Survival And Over-Winter Survival Of A Northern Bobwhite (Colinus Virginianus) Population In Southwest Florida, Steven Kenneth Brinkley

Masters Theses

The northern bobwhite (Colinus virginianus) is a gallinaceous upland game bird dependent on early successional grassland habitat for reproduction and survival. Bobwhite populations have been declining range-wide for nearly a half century. The habitat of Babcock-Webb Wildlife Management Area (BWWMA) in southwest Florida is mostly virgin, early successional grassland and pine flatwoods. Although BWWMA is located in the far southern end of the bobwhite range, the area is a popular public land for bobwhite hunting. The BWWMA bobwhite population has declined evidenced by a dramatic decrease in harvest over the last 20 years. The two objectives of my …

Capture-Recapture Of White-Tailed Deer Using Dna Sampling From Fecal Pellet-Groups, Matthew James Goode

Masters Theses

Reliable density estimates of game and keystone species such as white-tailed deer (Odocoileus virginianus) are desirable to set proper management strategies and for evaluating those strategies over time. However, traditional methods for estimating white-tailed deer density have been inhibited by behavior, densely forested areas that can hamper observation (detection), and invalid techniques of estimating effective trapping area. We wanted to evaluate a noninvasive method of mark-recapture estimation using DNA extracted from fecal pellets as the individual marker and for gender determination, coupled with a spatial detection function to estimate density (Spatially Explicit Capture-Recapture, SECR). We collected pellet groups …

Development Of An Environmental Monitoring System For Greenhouse Disease Management, Crystal Marie Kelly

Masters Theses

A commercial African violet (Saintpaulia ionantha) grower experiences yield loss due to a leaf spot disease known as Corynespora casssiicola. Spotted leaves make the plants unmarketable. Outbreaks of the disease are costly and difficult to prevent. Greenhouse monitoring systems currently available on the commercial market do not have sufficient spatial or temporal resolution to be able to correlate the environmental conditions of the greenhouse with disease outbreaks. A new system was designed specifically to monitor for disease favorable conditions. The system developed for this project consists of several sensor stations and a coordinator station. The coordinator station …

Influence Of Timing Of Prescribed Burn On Native-Warm Season Grass Forage Quality In Tennessee, Amanda L. Mathenia

Masters Theses

Native warm-season grass stands have the prospective to provide nutritious summer forage in grazing systems. The study examined the influence of timing of prescribed burn on native warm-season grass stands in Tennessee. The purpose of the study was to determine the nutritional quality of forage as it relates to the timing of prescribed burns on native warm-season grass stands in Tennessee. The prescribed burns were conducted in March, April, May, and September. Forage samples were collected at Ames Plantation, West Tennessee Research and Education Center, Bridgestone/Firestone Wildlife Management Area, and Yuchi Wildlife Management Area. These samples were then analyzed for …