Life Sciences Commons^™

A Multi-State Molecular Epidemiological Survey Of 16 Beef, Dairy, Poultry And Swine Farms To Facilitate Risk Assessment Of Listeria Monocytogenes, David Dean Rasmussen

Doctoral Dissertations

Listeria monocytogenes s an intracellular pathogen that poses serious risks for immuno-compromised individuals. On the farm risk assessment is needed to reduce exposure of such individuals to this pathogen. Base line epidemiological surveys for this pathogen are needed to identify common ecological reservoirs and sources. A 21 month survey of 4 animal farm types for L. monocytogenes in five different states was conducted to determine the level of occurrence in various environments. An overall occurrence of 1.4% (20/1432 samples) for L. monocytogenes was observed in this 21 month survey. Each sample type (soil, bedding/litter, feed/grass and animal rectal swabs) produced …

Immunotoxicological Study Of Depleted Uranium, Bin Wan

Doctoral Dissertations

The purpose of this study was to examine toxicity of depleted uranium (DU) to the immune system and the gene expression profile of DU-exposed immune cells including peritoneal macrophages, primary CD4⁺ T-cells and T Cell Hybridoma (TCH) PLP1 5B6. Flow cytometry analysis of annexin-V and Propidium Iodide (PI) binding revealed that DU causes death in those cells at various concentrations. The non-cytotoxic concentrations of DU determined in macrophages, primary CD4⁺ T-cells, and T cells hybridoma are 50µM, 100 µM, and 500 µM, respectively. Findings also revealed that DU-exposed macrophages are able to promote CD4⁺ T-cell proliferation in …

Antimicrobial Activity And Effect Of Selected Essential Oil Components On Cell Membrane Lipids, Valerie W. Ling

Doctoral Dissertations

The objectives of this study were to evaluate the antimicrobial activity of essential oil components (EOC) against Salmonella Typhimurium and Listeria monocytogenes and evaluate changes in bacterial membrane composition by observing changes in the fatty acids of Salmonella associated with exposure and adaptation to (or growth in the presence of) cinnamaldehyde (CIN) and carvacrol (CRV) EOC. Ten EOC were tested for efficacy using the broth microdilution and macrodilution methods. Beta-caryophyllene, limonene, alpha-pinene, and thymol were not lethal to Salmonella and Listeria at 2800mg/L. Dose-response models showed that the most effective EOC against Salmonella were CIN and CRV (50% probability of …

In Vitro Propagation, Regeneration, Attempted Tetraploid Induction, And Agrobacterium-Mediated Transformation Of Euphorbia Pulchurrima ‘Winter Rose’™, Kimberly Ann Pickens

Doctoral Dissertations

Poinsettia, Euphorbia pulchurrima, is the number one potted flowering plant in the United States. ‘Winter Rose’™ is a very popular cultivar with more than one million plants sold each year. To further improve this cultivar, particularly for larger flower heads and free branching, this research aimed at establishing some in vitro systems for application of biotechnology to poinsettia genetic improvement.

A protocol was established for in vitro axillary bud proliferation using greenhouse grown terminal buds. Buds were placed on Murashige-Skoog (MS) basal medium supplemented with benzlyaminopurine (BA). Explants produced the greatest number of axillary buds on medium containing between 2.2-8.8 …

Using A Bioluminescent Bacterial Bioreporter To Assess Iron Bioavailability In The Oceans, Cecile Elise Mioni

Doctoral Dissertations

Recent improvements in modern analytical methods have considerably increased our understanding of Fe biogeochemistry in the Ocean. Compiled data have shown that Fe concentrations are low in most open ocean surface waters and that the bioavailability of this Fe is influenced by organic complexation. Of presumed biotic origin, the importance of this organic complexation to Fe availability remains to be elucidated. Unfortunately, current analytical tools do not allow for a linkage to be established between Fe speciation to Fe bioavailability.

To supplement chemical analyses, we have developed a bioanalytical tool: a heterotrophic bacterial bioluminescent reporter system that responds quantitatively to …

Structure–Function Studies Of The Yeast Saccharomyces Cerevisiae Α–Mating Factor Pheromone Receptor Ste2p, Ayça Akal–Strader

Doctoral Dissertations

G protein–coupled receptors (GPCRs) are seven transmembrane domain cell surface proteins that respond to a variety of environmental cues. Response of these receptors to their cognate stimuli on the extracellular region of the cell results in a concurrent activation of a complex series of intracellular signaling pathways that prepare the cell for the required adjustments through regulation of gene expression levels. Participation of GPCRs in such intricate signal transduction pathways renders them important players in human diseases. The GPCR family of proteins therefore represents one of the largest classes of proteins to be targeted in the development of drug design …

The Role Of History In The Diversification Of The Funnel-Web Spiders, Agelenopsis Aperta, And Its Congeners, Nadia Antoine Ayoub

Doctoral Dissertations

Identifying the influence of history on the diversity of life is an important goal of evolutionary biology, whether it is an historical event that is extrinsic to the organism such as past climate change or an intrinsic event such as a single switch in behavior. Phylogenetic trees offer an indirect record of the history of diversification in a group of organisms and can be used in conjunction with other information to deduce the multiple roles of history affecting a particular group. Intra- and inter-specific phylogenetic relationships in the spider genus Agelenopsis Geibel (Araneae: Agelenidae) were analyzed using sequence data from …

An Analysis Of The End-Of-Life Choices Of Elderly Patients And Their Healthcare Providers At A Community Hospital In Tennessee, Elizabeth Harder Dobbins

Doctoral Dissertations

The Patient Self-Determination Act of 1990 was expected to popularize the use of advance directives (living wills and durable powers of attorney for healthcare (DPOA-HC)). Since the law was passed, researchers have found that the use of the documents has not increased as expected and that the documents, when present, were not always respected by healthcare providers.

The purpose of this study was to analyze the end-of-life choices of elderly patients and their healthcare providers in a community hospital setting. The subjects of this study were 160 patients, aged 65 years and older, who died in a community hospital in …

Online Atmospherics: An Investigation Of Feeling And Internet Purchase Intention, Kelly Price Rankin

Doctoral Dissertations

This study examines the online atmospheric cues of color and music and their impact upon feeling, attitude and purchase intention of consumers in the online environment. The research design was experimental and used data from a questionnaire. A pilot test of the instrument was conducted. The final questionnaire contained 39 items and a demographic section. A total of 200 questionnaires were collected. Participants were randomly assigned to one of four groups. Each group of 50 participants was exposed to a specific set of online atmospheric elements. The results indicated that Hypotheses 1, 3 and 4 were rejected while Hypotheses 2 …

The Dynamics, Distribution, And Activity Of Viruses In Lake Erie, Amanda Dean

Masters Theses

As viruses-- specifically pervasive pathogens of aquatic microorganisms-- are now included in most studies of aquatic food webs and nutrient cycles, presented here is new information from samples collected in July 2003 which demonstrates that bacteria lysed by viruses released 122 - 1080 nM of phosphorus per day throughout Lake Erie, implying that viruses acted as a major mechanism of phosphorus recycling in the lake. Viruses have been shown to be ubiquitous throughout Lake Erie, with a weak correlation between their distribution and the distribution of bacteria. Moreover, evidence suggests that virus production rates are tightly tied to the growth …

Physicochemical And Antimicrobial Properties Of Antimicrobials Encapsulated In Surfactant-Based Nanoparticles, Sylvia Gaysinksy Segura

Masters Theses

Phytophenols, components of essential oil extracts, are antimicrobials that may inhibit the growth of foodborne pathogens. However, their antimicrobial activity in food systems is low because of low water solubility and association with other food components. Incorporation of phytophenols in nanoscale surfactant micelles may offer a potential solution to increase solubility and improve activity in food systems. The objectives of this study were to determine the stability and physicochemical and antimicrobial properties of micellar antimicrobial-surfactant systems.

Carvacrol and eugenol containing micelles were prepared by dispersing Surfynol^® 485W and Surfynol^® 465 in water at room temperature. Stability was determined …

Levels And Patterns Of Genetic Diversity In The Rare And Endangered Cumberland Stitchwort, Minuartia Cumberlandensis (Caryophyllaceae), Charles Thomas Winder

Masters Theses

Sequences of a highly variable nuclear gene (G3pdh) were used to characterize genetic diversity within and among populations of the endangered rockhouse endemic, Minuartia cumberlandensis (Wofford and Kral) McNeill (Caryophyllaceae), and compared to a widespread and abundant related species, M. glabra (Michaux) McNeill. By reconstructing phylogenetic relationships among G3pdh variants (haplotypes) and observing the geographical distribution of those ordered variants, an attempt was made to gauge the effects of historical and contemporary population processes acting within the species, particularly those with potential implications for long-term conservation. Both M. cumberlandensis and M. glabra were found to have high overall …

Effect Of Resin And Wax Ratio On Osb Properties, Trairat Neimsuwan

Masters Theses

Oriented Strandboard (OSB) was made for construction purpose. Mat structure especially resin and wax ratio had an influence on major panel properties such as bending strength properties, stiffness properties, internal bonding, water absorption, thickness swell and so on. Thickness swell was an important property of OSB for using in construction and outdoor facilities. The purpose of this study was to investigate the effects of resin and wax ratio on OSB properties and rapidly predict OSB properties using near infrared spectroscopy. The laboratory OSB panels were fabricated as a multiple layer (three layers) mat structure including, orientation, resin types (phenol formaldehyde …

“Participation And Life Skill Development Of The Tennessee Junior Livestock Skillathon Programs, Amy Margaret Powell

Masters Theses

This study examined the Tennessee Junior Livestock Skillathon Program and its objectives. Research was conducted to determine what motivates or deters youth participation, how youth prepare for the skillathon and life skill development in the areas of communication, critical thinking and self-confidence. A self-developed, eleven question, likert scale survey was mailed to 200 randomly selected youth that exhibited livestock in the 2003 Tennessee Junior Livestock beef, sheep or market hog shows. Fifty-two percent (112) participants responded.

Youth that participate in the skillathon do so because they want to see how much they know about their project and they felt the …

Evaluation Of Botanical Oil Formulations For Management Of Powdery Mildew And Mites, Adriane Lorraine Cannon

Masters Theses

Experiments were conducted to evaluate the effects of newly created soybean oil formulations on powdery mildew (Erysiphe pulphra ), photosynthesis, phytotoxicity, and broad mites (Polyphagotarsonemus latus (Banks)) on dogwood ( Cornus florida (L.) 'Cloud Nine') trees, and to evaluate the amounts of formulations that are deposited and washed off of peach (Prunus persica, (L.)) leaves, dormant oak (Quercus phellos, (L.) ), and viburnum ( Viburnum x juddii) twigs after simulated rainfall. Oil treatments were applied using a back pack mist blower sprayed pre- and post- inoculation of powdery mildew to evaluate powdery mildew, …

Occurrence Of Escherichia Coli0157:H7 In Diverse Farm Environments In Five States, Carl Andrew Doane

Masters Theses

In the United States, foodborne outbreaks of Escherichia coli O157:H7 illness have often been linked to the consumption of contaminated, undercooked ground beef. However, the occurrence of E. coli O157:H7 in other animals has also been reported. The objective of this study was to determine the occurrence of E. coli O157:H7 in cattle, swine, poultry, and farm environments. Environmental samples (n=576) and fecal swab samples (n=1686) from sixteen locations in the U.S. were collected over 22 months. Overall, in fecal swabs E. coli O157:H7 was positive (serologically confirmed) in 4.7% of beef cattle (n = 408), 3.9% of dairy cattle …

Assessing Capacity For Collaborative Land Management In A Western Tennessee Community, Leslie Ann Horner

Masters Theses

Human and natural alterations resulting in sedimentation, flooding, and hardwood tree mortality in western Tennessee’s Hatchie River watershed represent a landscape-level natural resource problem. Flooding and tree mortality have significant negative economic impacts on the residents of the watershed’s communities. Efforts to address these ecological problems will need to be conducted at a landscape level, across various boundaries, involving multiple private landowners. In order to succeed in a cross-boundary restoration approach, the needs of the people and the ecosystem must be addressed. Collaboration in natural resource management has emerged as one tool for discovering and maintaining a balance between community …

Relationships Between Muskrats And Freshwater Mussels Prior To River Otter Restoration At Mammoth Cave National Park, Kentucky, Kimberly Ann Asmus

Masters Theses

The southeastern United States has a great diversity of freshwater mussel species, many of which are threatened with extinction. The muskrat (Ondatra zibethicus) is one of the few animals to extensively prey on freshwater mussels, and it has been implicated in retarding the recovery of, or further threatening, some endangered mussel populations. Muskrat predation on mussels may be significant at Mammoth Cave National Park (MCNP) where a river otter (Lontra canadensis) restoration has been proposed. Anecdotal observations suggest that the reintroduction of river otters dramatically reduces muskrat populations, which, in tum, may reduce the number of …

Seasonal Abundance Of Mosquitoes (Diptera: Culicidae) At A High And Low Prevalence Site For La Crosse Encephalitis In Eastern Tennessee, Nathan David Caldwell

Masters Theses

La Crosse (LAC), a California (CAL) serogroup bunyavirus, is the most prevalent pediatric arboviral disease in the United States and accounts for virtually all encephalitis cases associated with CAL serogroup arboviruses. In Tennessee, USA, prior to the drastic increase of confirmed La Crosse (LAC) encephalitis cases in 1997, the sum of documented cases reported to the Tennessee Department of Health totaled 9. During subsequent years in Tennessee (1997 to 2003), an average of 12 cases has been reported annually. Approximately 62% of these reported cases have occurred in the months of July and August. The native, container-inhabiting mosquito Ochlerotatus triseriatus …

Insulin Sensitivity And The Onset Of Hyperphagia In Fatty Rats, Holiday Agnes Durham

Masters Theses

Hyperphagia emerges suddenly after 22 days of age in Zucker fatty (fa/fa) rats, and fatties become visibly obese within days. This rapid increase in growth rate is likely to be associated with substantial changes in glucose metabolism. The objective of these experiments was to determine the relationship between insulin resistance and the onset of hyperphagia. Insulin tolerance tests showed that fatties were remarkably insulin resistant prior to the onset of hyperphagia, hyperinsulinemia, and obesity, but become as insulin sensitive as their lean littermates after the onset of hyperphagia. Furthermore, fatties became increasingly insulin resistant prior to the onset of …

Prostaglandin E2 Secretion And Effect On Adipocyte Lipogenesis, Patrick Allen Wortman

Masters Theses

With the current focus on the role of n-3 PUFAs as beneficial dietary interventions in the fields of cardiovascular disease and cancer, there has been a vastly increased awareness and focus on the mechanism of action for these essential fatty acids.

Many of the effects of PUFAs are mediated via changes in prostaglandin (PG) levels. One primary substrate for PGs is arachidonic acid (AA) (20:4 n-6), which results in the production of 2-series PGs. Increased concentrations of AA have been shown to increase levels of PGE₂ in vitro and in vivo. The omega-3 fatty acid EPA (20:5 n-3) is …

Antimicrobial Activity Of Trypsin And Pepsin Hydrolysates Derived From Acid-Precipitated Bovine Casein, Kellie Parks Burris

Masters Theses

Foodborne pathogens are a major concern to the food industry and consumers but they may be controlled with antimicrobials. Naturally occurring antimicrobials may be isolated from a variety of plant, animal and microbial sources. Previous studies have demonstrated that peptides isolated from enzyme hydrolyzed milk proteins may have in vivo and in vitro antimicrobial activity. Such compounds could be of use as inhibitors of foodborne pathogens. The objectives of this study were to determine the antimicrobial effectiveness against Salmonella Typhimurium and Listeria monocytogenes of digests of bovine acid-precipitated casein with the enzymes pepsin and trypsin and to determine if these …

Modifier Of Mdg4 Encodes A Protein Involved In Homologous Chromosome Pairing In Drosophila Melanogaster Males, Morvarid Soltani Bejnood

Doctoral Dissertations

Our research interest is to uncover mechanisms underlying meiotic chromosome pairing and segregation. pairing failure 2 (pf-2) is a gene involved in this process during meiosis I of male Drosophila. The three pf-2 alleles recovered in a screen for chemically induced (EMS) mutations on chromosome III that cause paternal loss of chromosome IV display strong meiotic phenotypes. Cytological analysis of testes of pf-2 mutant flies revealed unpaired chromosomes at prophase and metaphase I and “laggard chromosomes” at anaphase I in primary spermatocytes. Meiosis II appears relatively normal. Genetic data confirm that non-disjunction occurs at the first meiotic division …

Systematics And Species Concepts In The Genera Lentinus Fr. And Panus Fr., With Emphasis On The Lentinus Tigrinus, L. Crinitus And Panus Lecomtei Complexes, Edward A. Grand

Doctoral Dissertations

The monographic work of Pegler (1983) on Lentinus has established the taxonomic guidelines for most recent studies involving members of the genus (Moncalvo et al. 2002, Rolen 2001, Krüger 2002). Pegler’s taxonomic hierarchy combined both Lentinus Fr. and Panus Fr. into one large genus, Lentinus Fr. The combination of these genera and its validity was one of the reasons for beginning this study. For generic level comparisons, ribosomal DNA sequence data can be helpful for determining relationships among taxa (Binder and Hibbett 2002, Hibbett and Vilgalys 1991, 1993, Hibbett and Donoghue 2001, Moncalvo et al. 2002, Thorn et al. 2000). …

Integrating Geographic Information Systems And Remote Sensing With Spatial Economic And Mixed Logit Models For Environmental Valuation, Aaron Raymond Wells

Doctoral Dissertations

This research focuses on the Emory and Obed Watersheds in the Cumberland Plateau in Central Tennessee and the Lower Hatchie River Watershed in West Tennessee. A framework based on market and nonmarket valuation techniques was used to empirically estimate economic values for environmental amenities and negative externalities in these areas. The specific techniques employed include a variation of hedonic pricing and discrete choice conjoint analysis (i.e., choice modeling), in addition to geographic information systems (GIS) and remote sensing. Microeconomic models of agent behavior, including random utility theory and profit maximization, provide the principal theoretical foundation linking valuation techniques and econometric …

Role Of Mitochondrial Uncoupling Protein 2 (Ucp2) In Modulation Of Adiposity, Xiaocun Sun

Doctoral Dissertations

Obesity is a disorder of energy balance in which energy intake exceeds energy expenditure. Methods to control obesity through limiting energy intake have had limited success, and it is widely recognized that energy expenditure must also be increased if long-term weight loss is to be achieved. Uncoupling proteins (UCPs) are a family of integral membrane proteins of mitochondrial inner membrane, where they uncouple the process of mitochondrial respiration from oxidative phosphorylation, diminishing the resulting production of ATP and decreasing the metabolic efficiency of the organism. Thus, UCPs provide new molecular targets for increasing energy expenditure. Unlike the other UCP family …

Biological Knowledge Discovery Through Mining Multiple Sources Of High-Throughput Data, Yu Chen

Doctoral Dissertations

As we are moving into the post-genomic era, various high-throughput experimental techniques have been developed to characterize biological systems at the genome scale. The high-throughput data are becoming fundamentally important resources to shed new insights on system-level understanding of the ‘organization’ and ‘dynamics’ of molecules (e.g. genes and proteins), relationships between them, interaction cascades, pathways, modules and various networks (i.e. regulation, co-expression and metabolism). This dissertation focuses on developing computational tools to facilitate the process of translating the ever-growing volumes of high-throughput data into significant biological knowledge on protein functions, pathways and modules.

Although high-throughput data provide a …

Group Differences In Safety Climate Among Workers In The Nuclear Decommissioning And Demolition Industry In The United States, Michael Everett Findley

Doctoral Dissertations

This study investigated group differences in safety climate among workers in the nuclear decommissioning and demolition (D&D) industry in the United States. The study population representative of workers in a high reliability industry included employees and subcontractors who worked at one of 10 locations in the United States managed by a multi-national corporation performing nuclear D&D operations. Safety climate was measured with a self-reported questionnaire, the Health and Safety Executive’s Health and Safety Climate Survey Tool (CST). The voluntary and anonymous responses totaled 1,587 out of an available population of 3,296 for an overall response rate of 48.1 percent. Significant …

Mechanisms Of Paracrine And Endocrine Actions Of Angiotensin Ii, Suyeon Kim

Doctoral Dissertations

Adipose tissue expresses high levels of angiotensinogen (agt), the only known precursor of Angiotensin II (Ang II) and we have previously shown that this hormone plays a paracrine role in regulation of adipocyte metabolism by increasing activity and gene expression of two key liogenic enzymes, fatty acid synthase (FAS) and glycerol-3-phosephate dehydrogenase (GPDH). However, molecular mechanisms by which Ang II regulates an adipocyte lipogenic gene, namely FAS and transcription factors mediating this regulation are largely unknown. Furthermore, signaling mechanisms whereby Ang II induces adiposity need to be further explored. Accordingly, our studies were designed to investigate transcriptional regulation of FAS …

Prescribed Burning In Tennessee: Importance And Barriers, Goals, And Information Needs Of Private, State, And Federal Managers, Brian T. Hemel

Masters Theses

Early in the 20^th century, intense and severe wildfires were frequent due to abundant fuels generated by logging and the presence of anthropogenic ignition sources in close proximity to these fuels. As timber was depleted, this period of lumbering ceased and the realization that vast tracts of cutover land had to be reforested and protected led to the inception of fire suppression organizations and techniques. The fire exclusion that occurred over much of the 20^th century due to organized fire suppression efforts has led to two sets of problems: the buildup of fuels and the decline of fire-adapted …