Life Sciences Commons^™

Management Of Ticks And Tick-Borne Disease In A Tennessee Retirement Community, Jessica Rose Harmon

Masters Theses

Human Monocytic Ehrlichiosis (HME) is an emerging disease first described in 1987 and is transmitted by the bite of Amblyomma americanum. Over the past 10 years, the CDC has documented increasing ehrlichiosis case reports nationwide. Our study site is a golf-oriented retirement community located in the Cumberland Plateau of Tennessee. In 1993, four men at the study site had symptoms consistent with HME which prompted a CDC outbreak investigation and led community managers to mitigate ticks feeding on deer. The objectives of this study were to measure the efficacy of current tick mitigation attempts, to determine the level of …

Soil Moisture Profiles And Root Growth Of Hardwood Trees Planted In Different Groundcovers On The Steep Slopes Of Reclaimed Mine Sites, Elizabeth Anne Aubuchon

Masters Theses

Surface mining is a major industry in eastern Tennessee that removes much of the native forest. To restore the forest, reclamation practices are used. These include planting a ground cover species with native hardwoods. Competition between the ground cover and tree species for soil resources could hinder growth and decrease survival of the trees. Northern red oak (Quercus rubra) was used for this study to examine the possible effects of this competition and the relationships between root growth and soil moisture through a field and a greenhouse experiment.

A field experiment was designed using four different ground cover treatments (Soldiago …

Perceptions Related To Dietary Supplements Among College Students, Bethany Hope Brown

Masters Theses

Introduction: Prior research has shown that dietary supplement use is a common practice among college students. Most of these studies used surveys and questionnaires to provide an overview of supplement use in the U.S. However, in-depth information on college students’ perceptions and/or concerns related to dietary supplement use is lacking. The aim of this study was to capture a deeper understanding of how college students perceive dietary supplements.

Methods: A qualitative case study design was used, which allowed a greater understanding of the case through content analysis. The study used a secondary database, which consisted of web log (blog) posts …

An Improved Tissue Culture And Transformation System For Switchgrass (Panicum Virgatum L.), Jason Neil Burris

Masters Theses

Switchgrass (Panicum virgatum), a summer perennial grass native to North America, is currently being explored for its potential use in the production of biofuels. With these interests, genetic manipulation of switchgrass to produce plants that are easier to digest, have an increased resistance to diseases and stresses, and maintain viability longer in the field are required. Therefore, it was necessary to develop a reliable and efficient tissue culture system for the transformation of switchgrass. Current switchgrass tissue culture requires months for regeneration of transformants with relatively poor transformation efficiencies and are limited to derivatives of a single variety, Alamo. We …

Developing, Refining, And Validating A Survey To Measure Adolescent Food Safety Self-Efficacy, Monica K Brandon

Masters Theses

Self-efficacy is a proven indicator of predicting risky behaviors, but without a baseline level of adolescent food safety self-efficacy to develop targeted interventions it is difficult to produce meaningful behavior change. The research question around which this study was designed is: To what extent can a validated instrument accurately capture adolescent beliefs of food safety self-efficacy. Through rigorous field testing and statistical analysis we hypothesize a valid and reliable instrument can be created for measuring adolescents’ food safety self-efficacy. The purposes of this study included: (a) development of a high quality, food safety self-efficacy instrument, (b) validation of the instrument …

Antimicrobial Activity Of Casein Hydrolysates Against Listeria Monocytogenes And Escherichia Coli O157:H7, Jessica M Christman

Masters Theses

Listeriosis has the highest fatality and hospitalization rate among foodborne illnesses. Listeria monocytogenes causes listeriosis and is a difficult bacterium for ready-to-eat food processors to eliminate because of its ability to grow in the absence of oxygen and under refrigeration. Recently, milk and its proteins have gained recognition as the largest source of biologically active peptides, and, it stands reason that several antimicrobial peptides (AMP) can be released from casein as it is the most abundant milk protein. AMPs are commonly obtained by cutting the whole protein into peptide fragments using enzymes or by acidification. The objective of this study …

Youth Can! Grow Healthy!, Andrew Nils Carberry

Masters Theses

This study presents a formative evaluation of an afterschool program that combined youth development and school garden curricula. This program used a novel approach to teach elementary school children about fruits and vegetables and to engage them in advocacy for the physical activity and nutrition environments in their community. The youth development curriculum included sessions on team building, community pride, healthy eating and physical activity, and advocacy. Photovoice was used as a method to allow participants to assess their community and communicate findings with leaders. Participants selected community leaders to invite to their school and shared their findings via a …

The Effects Of Living Mulches On Organic, Reduced-Till Broccoli Growth And Management, Sarah Elizabeth Broughton

Masters Theses

Conservation tillage programs have been successfully implemented for many agronomic cropping systems, but adoption of reduced tillage for vegetable crops has been slow. As many conventionally managed conservation tillage programs rely on synthetic herbicides for clean cultivation, alternative methods must be devised to suppress weed pressure and reduce reliance on mechanical cultivation to aid in the development of reduced tillage programs for organic cropping system. Strip tillage is a reduced tillage method that is well suited to vegetable crop production, and the utilization of cover crops and living mulches between rows provides a viable weed management option for organic systems. …

Structural And Functional Analysis Of Toc75, Ashita Mukul Dave

Masters Theses

The majority of chloroplast proteins are nuclear-encoded and post-translationally imported into the chloroplast. These newly imported proteins are translocated from the cytosolic compartment to the stroma by the Translocons of the Outer/Inner membranes of Chloroplast (TOC/TIC). In order to understand protein transport across the chloroplast outer membrane, it is crucial to investigate the structure and function of these complexes. The TOC complex is composed of the beta-barrel channel protein Toc75 and the GTPase receptors Toc34 and Toc159.

Toc75 is a member of the OMP85 (Outer Member Protein, 85 kDa) superfamily. Other proteins of the OMP85 superfamily also exist in Gram-negative …

Novel Approaches For The Efficient Sampling And Detection Of Listeria Monocytogenes And Brochothrix Thermosphacta On Food Contact Surfaces, Jessica Anne Clemons

Masters Theses

The primary step in the microbiological assessment of highly dynamic and complex food processing conditions is environmental sampling. The objectives of this study were to: (1) compare the efficacy of four sampling devices including Microbial-Vac system (MV), cellulose sponge (SP), polyester swab (SW) and composite tissue (CT), for the recovery of Listeria monocytogenes and Brochothrix thermosphacta on five surfaces and (2) to determine if there was a significant difference between the recovery of low (10 CFU/900cm²) and high (100 CFU/900cm²) L. monocytogenes inoculum levels using the sampling devices in a simulated food processing environment. Surfaces used …

The Effects Of Weaning Strategy On The Physiology And Performance Of Beef Calves, Cristina Campistol

Masters Theses

Two experiments examined growth performance and physiological measures of stress in pre- and postweaned Angus steers (313 ± 24.5 kg; n = 48/Exp.), where steers were fitted with (YD) or without (ND) an anti-suckling device (Exp. 1), or provided (YS) or not provided (NS) a grain supplement (Exp. 2) for 7 d and weaned by fenceline (FS) or total separation (TS). Steers in Exp. 1 were weighed and bled on d 0, 3, 7 10, 14, 21, and 42, and in Exp. 2, on d 0, 7, 10, 14, and 21 and provided a grain supplement on d 7-21. In …

Assessment Of Control Charts For Evaluating Dynamic Accuracy Of Forest Growth Models, Richard Raymond Cristan

Masters Theses

The purpose of this study was to determine if control charts are an effective tool to identify trends in forest growth and yield model accuracy. Accurate forest growth and yield models are important for projecting future forest composition. However, environmental factors have the potential to make forest growth models created from historic data inaccurate. Control charts in this study determine if forest growth predictions fall within confidence limits established for historic growth at a number of points in time. Two data sets were used in this study: the first was a Continuous Forest Inventory (CFI) from three tracts at the …

Applied Ecosystem Services In Working Forests: A Direct Market Valuation, Darin Stuart Hale

Masters Theses

Ecosystem services, or the benefits humans obtain from natural ecosystems, have long been recognized as critical to human health. Efforts have been taken by many to determine the non-market values of these services but few have offered a direct market valuation. Increasing awareness, scarcity, and regulation have fostered transactions, and markets are emerging that can allow for direct valuation and could provide landowners the opportunity to merchandise this natural capital. This paper provides a valuation and comparison, as a case study, of a traditional management scheme, including the marketing of fiber and recreational leases, and an ecosystem services management scheme, …

Impacts Of Predation Risk And Development On Susceptibility Of North American Anurans To Ranaviruses, Nathan Alden Haislip

Masters Theses

For over three decades, amphibian populations have been declining across the globe. Emerging infectious diseases are responsible for some of these declines. Ranaviruses have caused die-offs in wild amphibian populations on 4 continents, in 5 Canadian provinces, and in over 25 U.S. states. In order to understand host-pathogen dynamics, it is critical to establish baseline information on species susceptibility and the effects of natural stressors. The goal of my thesis research was to quantify the effects of anuran development and exposure to invertebrate predators on species-specific susceptibility to ranavirus. My experiments were designed in factorial arrangements, and consisted of exposure …

Competitive Interactions Between Appalachian Hardwoods And Different Groundcovers On Reclaimed Mine Sites, Adam David Klobucar

Masters Theses

Coal mining is a significant industry in Appalachia. Herbaceous groundcovers are commonly planted to reduce soil erosion and protect water quality during mine reclamation, but many groundcovers may be too competitive to be compatible with trees. The objectives of this research were to investigate the performance of trees planted within different groundcovers and to measure how different groundcovers influence resource availability, specifically soil moisture and light

Two studies were performed; one in a greenhouse and the other on 3 mine sites in east Tennessee where seedlings were planted and grown in competition with different groundcovers. Growth, biomass, leaf area, and …

Study Of The Structure And Function Of Cxc Chemokine Receptor 2, Hae Ryong Kwon

Masters Theses

It has been shown that the amino terminus and second extracellular loop (EC2) of CXCR2 are crucial for ligand binding and receptor activation. The lack of an ionic lock motif in the third intracellular loop of CXCR2 focuses an investigation of the mechanism by which these two extracellular regions contribute to receptor recognition and activation.

The first objective of this investigation was to predict the structure of CXCR2 based on known structures of crystallized GPCRs. Rhodopsin, β2-adrenergic receptor, CXCR4 were used for homology modeling of CXCR2 structure. Highly conserved motifs found in sequence alignments of the template GPCRs were helpful …

Study Of Population Diversity Of Toxoplasma Gondii, Debashree Majumdar

Masters Theses

Toxoplasma gondii, the causal agent of toxoplasmosis, is an important water and food borne protozoan parasite. T. gondii was previously shown to have a distinct clonal population structure composed of Type I, II and III lineages in North America and Europe. But more recent studies demonstrated high diversity in South America. In the present project we have conducted an intensive study of the population diversity of T. gondii and surveyed the extent of genetic variation among natural T. gondii isolates on a global scale in order to better understand the population dynamics and pathogenesis of this parasite. To this …

Control Of Glyphosate Resistant Horseweed (Conyza Canadensis) With Saflufenacil And Tank-Mixture Partners., Brock Steven Waggoner

Masters Theses

Field and labratory studies were conducted to determine the efficacy of saflufenacil alone and with mixture partners for burndown. Field studies were conducted in 2009 and 2010 to evaluate saflufenacil in mixtures with glyphosate, glufosinate, or paraquat for control of glyphosate-resistant (GR) horseweed prior to planting cotton. Saflufenacil and saflufenacil mixtures were applied 7 days before planting (DBP). Saflufenacil at 25 and 50 g ai ha-1 in mixture with all three non-selective herbicides provided similar GR horseweed control when compared to the current standard of glyphosate plus dicamba. Control of GR horseweed was also not different at the 25 and …

Regional Differences In Adipose Tissue Of The Sinclair Minipig, Suzanne Lauren Booker

Masters Theses

Adipose tissue is an endocrine organ, and its homeostatic mechanisms in normal weight, overweight and obese subjects must be elucidated. We sought to determine the basal adipose tissue biology of visceral (VIF) and subcutaneous (SQF) fat depots in 8 month old Sinclair minipigs, an animal that has been shown to be physiologically similar to humans.

Metabolic analysis showed a decrease in LDL, white blood cells (WBC), and lymphocyte percentages as the minipigs aged from 6 to 8 months (p <0.0001 and = 0.0046 and 0.0165 respectively). There were no significant changes in triglycerides, HDL, VLDL, and neutrophil percentages. There was a trend in insulin increase (P=0.0722).

Microarray analysis was performed to determine transcriptome differences between VIF and SQF. When VIF was compared to SQF, expression of a …

Family Mealtimes, Dietary Quality, And Body Mass Index In Children, Claudia Christine Favre

Masters Theses

Frequency of family mealtimes has been positively linked to dietary quality and weight status in children; however, there is a lack of research identifying what components of family mealtimes are associated with this positive effect. This study investigated family mealtime components that may impact dietary intake and weight status in children aged 5-11 years.

Participants were 50 parent/child pairs (child: age = 7.3 ± 2.0 years, female = 44%, standardized body mass index (zBMI) = 0.55 ± 1.0, overweight/obese = 26.0%; parent: age = 36.8 ± 8.7 years, female = 76%, BMI = 29.0 ± 6.6 kg/m2, overweight/obese = 74.0%) …

Soil Nitrogen Amendments And Insect Herbivory Alter Above-And Belowground Plant Biomass In An Old-Field Ecosystem, Jarrod Dwayne Blue

Masters Theses

Nutrient availability and herbivory can regulate primary production in ecosystems, but little is known about how, or whether, they may interact with one another. Here I investigate how nitrogen availability and insect herbivory interact to alter above- and belowground plant community biomass in an old-field ecosystem. In 2004, 36 experimental plots were established in which soil nitrogen (N) availability (at three levels) was manipulated and insect abundance (at two levels) in a completely randomized plot design. In 2009, after six years of treatment, I measured aboveground biomass and assessed root production at peak growth. Overall, I found a significant effect …

Drought Response Of Populus Transformed With Stress Response Transcription Factors, Alina S. Campbell

Masters Theses

The economic feasibility of producing biomass-based fuels requires high-yielding feedstocks to supply biomass to biorefineries. Populus trees are a potential biomass feedstock due to their high yield, but their high water requirement limits productivity under drought conditions.

The number of genes controlling drought tolerance, and the long generation time for perennial species, slows cultivar development. Accelerated domestication proposes using the sequenced Populus genome to quickly incorporate target traits into productive clones by transgenesis.

Six putative drought tolerance transcription factors: DREB2A, DREB2B, AtMYB, AREB1/ABF2, MYB, and NAC, had been previously identified and manipulated in eastern cottonwood (Populus deltoides). Three …

Effect Of Tilted Surfaces On Ankle Kinematics And Emg Activities In Landing, Divya Bhaskaran

Masters Theses

The purpose of this study was to examine the effects of landing on a combined inverted and plantarflexed surface on the ankle kinematics and electromyographic (EMG) activities of the medial gastrocnemius (MG), peroneal longus (PL) and anterior tibialis muscles (TA). Twelve recreational athletes performed five drop landings from an overhead bar of 30 cm height on to each of these surfaces: a flat surface, a 25° inversion surface (inverted), and a combined surface (combined) of 25° inversion and 25° plantarflexion. The three dimensional kinematic variables and integrated EMG (IEMG) of the three muscles were assessed using one-way repeated measures analysis …

Population Abundance And Genetic Structure Of Black Bears In Coastal South Carolina, John Michael Drewry

Masters Theses

Because of increasing frequency of bear sightings, vehicle collisions, and nuisance incidents in coastal South Carolina, the South Carolina Department of Natural Resources is developing a comprehensive black bear management plan. However, no reliable estimates of population abundance or density are available. I used genotypes of black bears determined from hair samples collected in Lewis Ocean Bay and Carvers Bay to estimate population abundance and density. I obtained hair samples from snares during 8 weekly sampling periods in 2008 and 2009. I used Huggins closed population models to estimate abundance and spatially explicit capture- recapture models to estimate density. Based …

Effect Of Double Interspiking On Fertility, Behavior, And Blood Parameters In Broiler Breeder Males Reared Under Heat Stress Conditions, Karianne Mei-Ying Chung

Masters Theses

Broiler breeders experience a natural decline in fertility levels as a flock ages. A male management practice such as double interspiking could be applied to counteract this decline. Our objective was to investigate the effects of double interspiking on flock fertility, testosterone concentrations, stress responses, and behavioral responses of broiler breeders in heat stressed environments. Two hundred and eighty-eight broiler breeder pullets and thirty-six broiler breeder roosters (Ross 708) were assigned to three groups at 21 weeks of age (WOA). All three groups were housed in slatted floor pens in which room temperature cycled from 23.8 to 30 C to …

Naive And Memory T Cell Trafficking In Selectin Ligand-Deficient Mice: The Role Of Fucosyltransferase –Iv And –Vii In The Differential Migration Of T Cell Populations, John Robert Harp

Masters Theses

The correct and timely delivery of immune cells is critical for protection against foreign antigen. In order for cells to access most organs, there are requirements that must be met to facilitate exit from the blood into extravasculature. The initial requirement is selectin-selectin ligand interactions that mediate tethering and rolling to allow shear resistance. For proper selectin-selectin ligand interaction, glycoproteins must be modified by fucosyltransferases –IV and –VII, which adds fucose to an acceptor substrate to form the sialyl-LewisX moiety. Using fucosyltransferase –IV and –VII double knockout (FtDKO) mice, we made several novel observations. Our first observation showed increased numbers …

Microstegium Vimineum Spread Rate In Relation To Two Different Leaf Litter Disturbances And An Evaluation Of Aboveground Biomass Accumulation And Photosynthetic Efficiency In Response To Four Light Treatments, John Andrew Hull

Masters Theses

Microstegium vimineum is a non-native invasive plant species classified as an annual, shade-tolerant C4 grass. There is limited research regarding variables affecting the spread of M. vimineum. Two studies were conducted to investigate the spread of M. vimineum. A field study was undertaken in 2009 to determine how M. vimineum spreads in relation to litter disturbance. In 2010, a greenhouse study was conducted to determine the impact light has on M. vimineum aboveground biomass, height growth, and photosynthetic efficiency.

The field study consisted of three treatments, Undisturbed (Control), Stirring, and Removal of leaf litter, employed along the boundary of existing …

Influenza-Specific B Cell Responses In Hla-Dr1 Transgenic Mice, Lifang Huan

Masters Theses

HLA-DR1 transgenic (DR1 Tg) mice provide a model for evaluating the breadth and specificity of CD4 T cell responses that may develop in humans following influenza infection or vaccination. Recent studies identified a tremendously broad HLA-DR1-restricted CD4 T cell responses in DR1 Tg mice infected intranasally with influenza A/New Caledonia/20/99 (NC). In this study, our goals were to characterize B cell responses after NC infection in DR1 Tg mice and establish the correlation between B cell responses and CD4 T cell responses in this system. Influenza-specific B cell responses following virus administration were analyzed in DR1 Tg mice and in …

Fungal Endophytes Enhance Growth And Production Of Natural Products In Echinacea Purpurea (Moench.), Richard James Gualandi Jr.

Masters Theses

Echinacea purpurea is a native herbaceous perennial with substantial economic value for its medicinal and ornamental qualities. Arbuscular mycorrhizae are symbiotic fungi that form relationships with plant roots and are known to enhance growth in the host. Mycorrhizae and other fungal endophytes often affect stress resistance and secondary metabolism in the host, as well as the ecology of other endophytes in the plant. A newly emerging paradigm in sustainable biotechnique is the targeted use of fungal endophytes to enhance growth and secondary metabolism in crops. Many of the therapeutic compounds in E. purpurea could be affected by fungal colonization. In …

Physical Characteristics And Metal Binding Applications Of Chitosan Films, Joshua B. Jones

Masters Theses

Chitosan films are an excellent media for binding metal ions due to the electrostatic nature of the chitosan molecules. Addition of cross-linking or plasticizing agents alters texture of the films, but their effect on metal-binding capacity has not been fully characterized. The objective of this research was to determine effects of plasticizers and cross-linkers on physical and metal-binding properties of chitosan films and coatings prepared by casting and by spincoating. Chitosan films were prepared using 1% w/w chitosan in 1% acetic acid with or without (control) additives. Plasticizing agents were tetraethylene glycol (TEG) and glycerol while citric acid, ethylenediamine tetraacetic …