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The Tangled Web Of Community Ecology: Making Sense Of Complex Data, Monica Lynn Beals

Doctoral Dissertations

Ecological communities are governed by complicated processes that give rise to observable patterns. Making sense of these patterns, much less inferring the underlying processes, has proved challenging for several reasons. Manipulative experiments in natural communities may not be feasible due to large numbers of variables, lack of adequate replication, or the risk of undesirable consequences (e.g., introducing an invasive species). The multivariate nature of ecological datasets presents analytical problems as well; many statistical techniques familiar to ecologists have difficulty handling large numbers of potentially collinear variables. I present results from three studies of spider communities in which I employ a …

Avian Community Ecology: Patterns Of Co-Occurrence, Nestedness, And Morphology, Michael David Collins

Doctoral Dissertations

A central tenet of the competition paradigm is that community structure is governed by deterministic rules. The competition paradigm pervades nearly all subdisciplines and extends to the broadest, deepest questions in ecology. To determine whether patterns of co-occurrence, nestedness, and morphology in avian communities are consistent with a competition hypothesis, I use null models to compare observed patterns to patterns expected in the absence of competition.

I use presence-absence matrices of birds in three archipelagoes to test whether species exhibit exclusive distributions. Congeneric birds co-occur significantly less frequently than predicted in two archipelagoes, consistent with a competition hypothesis. However, when …

Studies On Cytochrome P450 Genes In Drosophila Melanogaster: Relationship Between Over Expression And Ddt Resistance, And Xenobiotic Induction, Srilalitha Kuruganti

Doctoral Dissertations

Cytochrome P450 monooxygenases (CYPs), are involved in the metabolism of a diverse group of endogenous and xenobiotic compounds. In insects, CYPs are involved in conferring resistance against insecticides. In Drosophila, the expression of Cyp6a2, Cyp6a8, Cyp6g1, Cyp6w1 and Cyp12d1 is higher in the resistant compared to susceptible strains. Recent study by Daborn et al (2002, Science, 297, 2253-2256) showed that Cyp6g1 alone can confer resistance phenotype. The aim of my first objective was to re- examine this claim and second to examine the effect of common xenobiotic compounds on the transcriptome of Drosophila.

In first objective, six strains …

An Integrated Experimental And Computational Approach To Proteomics: Scaling From High Resolution Qualitative Analysis To Quantitative Measurements With Confidence Evaluation, Chongle Pan

Doctoral Dissertations

As a component of systems biology, proteomics aims to characterize the entire protein complement of an organism, including qualitative identification of protein types and quantitative measurement of protein abundance changes as a function of different cellular states. This dissertation presents an integrated experimental and computational approach to improve proteomic measurements, including qualitative measurements using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and quantitative measurements with statistically derived confidence evaluation.

Although FT-ICR-MS provides high-performance mass measurements, its potential has not yet been fully explored for proteomics applications. A novel tandem mass spectrometry method was developed for FT-ICR-MS to obtain sequence …

Cross-Species Comparison Of Spermatocyte Responses To Induced Dna Damage: The Laboratory Mouse And Drosophila Melanogaster, Shannon Marie Matulis

Doctoral Dissertations

Maintenance of genomic stability is of crucial importance for all organisms. Cells are continually exposed to exogenous and endogenous agents that can damage DNA. Of special interest is the manner in which male germ cells respond to and repair induced DNA double strand breaks (DSBs), as the propagation of cells carrying damaged DNA can lead to the production of heritable mutations, genetic diseases, and sterility. In addition, treatment of male germ cells with DNA damaging agents, such as many chemotherapeutic drugs, can ultimately result in infertility. This research focused on investigating the mechanisms by which male germ cells, specifically those …

Physicochemical Characterization And Antibacterial Potential Of Naturally-Occurring Antimicrobial Polypeptide-Bearing Phospholipid Liposomes Against The Foodborne Pathogens Listeria Monocytogenes And Escherichia Coli O157:H7, Thomas Matthew Taylor

Doctoral Dissertations

Liposomes are spherical bilayer vesicles formed from dispersion of polar lipids in aqueous solvents and have been studied for their ability to act as drug delivery vehicles by shielding reactive or sensitive compounds prior to release. In the food industry, liposomes have been used to deliver food flavors and nutrients; more recently they have been investigated for their ability to incorporate food antimicrobials.

Thermal stability of liposomes, in the presence and absence of nisin, was evaluated using differential scanning calorimetry (DSC) and low-intensity ultrasonic spectroscopy (US). Observed phase transition temperatures for liposomes measured via DSC and US were in close …

The Effects Of Processing On Hydrophilic Antioxidant Capacity Of Black Beans, Elizabeth Roberson Mcgee

Masters Theses

Dry, uncooked black beans have been found to contain a significantly high amount of antioxidants compared to many other foods. There is little information available on the influence of thermal processing on antioxidant capacity of foods. The antioxidant capacity, reported in μmol Trolox Equivalents per gram of uncooked, blanched, or retorted black beans was evaluated using the oxygen radical absorbance capacity (ORAC) assay. A boiling water blanch of black beans for 30, 60 or 90 sec resulted in a 33% reduction in antioxidant capacity compared to uncooked beans. There was no significant difference among antioxidant capacity of beans blanched for …

Established Predators Of Fiorinia Externa Ferris (Hemiptera: Diaspididae) On Eastern Hemlock (Tsuga Canadensis (L.) Carriere) In Urban And Forest Sites, Christine Ann Lynch

Masters Theses

A project was initiated in September 2004 to determine the indigenous predators of Fiorinia externa Ferris, the elongate hemlock scale (EHS), on eastern hemlock and their impact on the pest populations. Branch samples were taken monthly from four sites (two forest and two urban) in eastern Tennessee and western North Carolina to assess predator damage from October 2004 to April 2006. Predators of this exotic pest were collected from beat sheet samples from September 2004 to May 2006. Laboratory tests were conducted from field-collected predators to assess food consumption, feeding behavior, and intraguild competition among predators of EHS. From field …

Bmp Adoption In Two East Tennessee Watersheds, Michael Barrowclough

Masters Theses

Voluntary adoption of Best Management Practices (BMPs) has been the foundation among many environmental conservation programs geared towards non-point source pollution. While farmers view BMPs as being both appropriate and problematic, there remain many constraints to BMP adoption on the farm. The objective of this research was to determine the criteria beef and dairy producers used in their decision making process on whether or not to adopt a given BMP or set of BMPs in the Pond Creek and Oostanaula Creek watersheds located in East Tennessee. Results are presented of exploratory sociological research designed to better understand how farmers select …

Associations Of Subjective Social Status And Perceived Stress To Dietary Behaviors In College Students, Eriko M. Grover

Masters Theses

The purpose of this study was to examine the relationship that subjective social status indicators and perceived stress share with unhealthy diet behaviors. A total of 898 incoming freshmen students at the University of Tennessee, Knoxville (UTK) completed a web-based survey as part of a pilot study prior to their arrival at the UTK. Two versions of the Subjective Social Status (SSS) scale were used to assess incoming freshmen’s perceptions of social standing in their high school environment and in a larger societal context. The Perceived Stress Scale (PSS) was used to assess stress. Diet was analyzed by assessing frequency …

Occupancy Of Small Mammals On Private Lands In The Emory/ Obed Watershed, Tennessee, Carrie Hedio Salyers

Masters Theses

The Emory/Obed watershed of the Cumberland Plateau area of Tennessee is an important area for wildlife conservation and has recently been subjected to land-use changes. This study was conducted to determine if occupancy of selected mammalian species was affected by land-use and habitat characteristics, and to provide baseline data before further land-use changes occur in the region. Small mammal trapping was conducted in a total of 132 sample sites from June through August in 2002, 2003, and 2004 using live traps. A total of 11 mammalian species was trapped. Three species were trapped in sufficient numbers to evaluate occupancy and …

Consumer Perceptions Of Branded Beef Products, Leslie Erin Williams

Masters Theses

This study examined consumer perceptions of branded beef products. Research was conducted to determine what motivates consumers to purchase branded beef products. In addition, this study focused on consumer perceptions of quality, risk, added value, credibility and loyalty toward both branded beef products in general and branded beef products when compared to non-branded beef products.

A self-developed question guide was used as a guide for the focus group and the in-depth interviews. This study entailed one focus group with nine participants and nine one-on-one in-depth interviews.

The majority of participants in this study held a positive impression of branded beef …

Probing Precursor Interactions With The Chloroplast Import Apparatus, Sarah Jean Wright

Masters Theses

The majority of plastid proteins are nuclear-encoded and imported post-translationally. A cleavable N-terminal extension, the transit peptide, targets these preproteins to the plastid. Transit peptides show very little primary sequence homology, yet are able to direct the precursor protein to interact with the protein components of the translocation complexes located within the inner and outer membranes of the chloroplast. In this study, a semi-conserved motif of the transit peptide, (F/W)(P/G)h(R/K) has been targeted for deletion in order to probe its importance. Two corresponding regions were deleted in the transit peptide of the precursor to the small subunit of Rubisco (prSSU) …

Insights Into The Etheostoma Spectabile Species Complex: Incongruence Between Mitochondrial And Nuclear Gene Sequence Data, Christen M. Bossu

Masters Theses

Hybridization is recognized as an evolutionary process that can provide a significant source of genetic variation and whose genetic consequences have been investigated across a wide taxonomic range of plants and animals. Darters (Percidae: Etheostomatinae) are a clade with documented interspecific hybridization and many species with a recent evolutionary origin, yet most molecular phylogenetic analyses of darters to date have relied primarily on mitochondrial DNA (mtDNA) sequences. Inferring relationships within and between closely related species using a single locus gene tree is potentially confounded by introgression as well as retention of ancestral polymorphisms. This can lead to incongruence between the …

Horizontal Gene Transfer To Bacteria Of An Arabidopsis Thaliana Abc Transporter That Confers Kanamycin Resistance In Transgenic Plants, Kellie Parks Burris

Masters Theses

The use of antibiotic resistance markers is an important tool in the production and selection of transgenic plants. There have been increased concerns about the potential horizontal gene transfer (HGT) from transgenic plants to bacteria of medical and environmental importance. Until recently all antibiotic resistance genes used in transgenic studies have been bacterial in origin. An Arabidopsis thaliana ABC transporter, Atwbc19, was the first plant gene shown to confer kanamycin resistance when overexpressed in transgenic plants. The Atwbc19 gene was evaluated for its ability to transfer antibiotic resistance to Escherichia coli, which are found in the human gut and environment. …

Occurrence Of Antibiotic Resistance In Environmental And Amphibian E. Coli Isolates Associated With Cattle And Aquatic Environments, Robin Lynn Cissell

Masters Theses

The widespread use of antibiotics in human medicine and livestock production has been linked to an increase in resistant bacteria, which may carry transferable resistance factors, including integrons. Foodborne pathogens, such as Escherichia coli and salmonella, commonly reside in livestock, including cattle, and these pathogens may acquire resistance genes as a result of routine antibiotic use. As cattle are often located in close proximity to aquatic environments, they may disperse antibiotic resistant pathogens into such environments, which may lead to contamination of aquatic wildlife. We hypothesize that class 1 integrons and/or antibiotic resistant bacteria occur more frequently in environments with …

Evaluation Of Socioeconomic Characteristics Of Farmers Who Choose To Adopt A New Type Of Cropand Factors That Influence The Decision To Adopt Switchgrass For Energy Production, Pamela C. Ellis

Masters Theses

Evaluating farmers’ perceptions and obtaining feedback about the adoption of a new crop is necessary for improving the efficiency of research, technology exchange, and information flow to policymakers. New technology has created new uses for non- traditional crops (such as switchgrass) as a sustainable source of energy. With new technology utilizing non-traditional crop uses, it is important to discern and understand the determinants of farmers’ behavior and attitudes toward new crop adoption rather than new technology adoption. Farmers must analyze financial and social costs and benefits of new crops, farming practices, and economic activities. Better understanding of the factors farmers …

The Effects Of Pathogen Infection On Nitrogen Remobilization In Arabidopsis Thaliana, Michelle Ann Boercker

Masters Theses

The natural enemies of plants are ubiquitous and can reduce plant fitness. Plants have evolved two defense strategies to ameliorate the fitness cost associated with natural enemy attack. The first strategy, resistance, reduces the frequency and/or severity of natural enemy damage. The second strategy, tolerance, attenuates the fitness cost of natural enemy damage. Very little is known about the traits through which tolerance is manifested, particularly with respect to plant-pathogen systems (pathosystems). Diseased and naturally senescing leaves are often similar in their visible symptoms and molecular activities, suggesting that they may involve similar processes. One process that may be shared …

Cultivation Of Phylogenetically Diverse And Metabolically Novel Atrazine Degrading Soil Bacteria Using Bio-Sep® Beads, Emily Catherine Martin

Masters Theses

The s-triazine herbicide atrazine is among the most widely used herbicides worldwide. The human health effects of atrazine exposure remain unclear, but atrazine and its metabolites appear to cause developmental abnormalities in amphibians. A mounting body of knowledge concerning the ecology of atrazine degradation suggests the current collection of microorganisms and genetic biomarkers of atrazine degradation cannot accurately predict the natural attenuation of atrazine. To this end, a novel in situ enrichment approach using highly porous, atrazine-impregnated Bio-Sep® beads was employed to isolate a taxonomically diverse group of atrazine-degrading bacteria from soil and wetland environments in Tennessee and Ohio. The …

Supplementation Of Purified Fiber To Tall Fescue Grass Hay Diets, Howard Martin Blalock

Doctoral Dissertations

Experiments were conducted to define the degradation kinetics of purified fiber products compared to conventional feedstuffs. In situ analysis was conducted on soybean hulls, dried distillers grains, dried corn gluten feed, rice mill, wheat middlings, solka floc, oat fiber (200 and 300 series), corn bran, red and white wheat bran using nylon bags. In situ results determined oat fiber (300) and solka floc were most similar to soybean hulls and secondly to corn gluten feed. An oat fiber: solka floc mixture was formulated for subsequent experiments. The in vitro experiment consisted of alfalfa hay, soybean hulls, corn gluten feed, oat …

Inhibition Of Direct Prostaglandin F2Α Effects On Pre-Attachment Embryos Improves Reproductive Efficiency In Cattle, Fernando Nestor Scenna

Doctoral Dissertations

Prostaglandin F_2α (PGF_2α) has been shown to have detrimental effects on embryonic development, quality and hatching ability of embryos and pregnancy rates in cows. However, information about PGF_2α receptor (FPr) mRNA and protein in the preattachment bovine embryo is absent in the literature. The first experiment was design to identify the period of time during in vitro embryo development that is most susceptible to PGF_2α and to determine FPr mRNA and protein in bovine embryos. Prostaglandin F_2α decreased development of embryos to compact morula, but had no effect on development to blastocyst. In addition, …

Sp307-K-Pruning Neglected Fruit Trees, The University Of Tennessee Agricultural Extension Service

Home Garden, Lawn, and Landscape

When trees have not been properly pruned and trained, fruit yields and quality may decline. As trees grow taller and more dense, lower limbs and interior limbs lose their ability to produce quality fruit, due to increased shading. Many of these weakened limbs will die. Over time, most fruit will be produced in the outer periphery of the tree, primarily in the top, as this is the only area exposed to adequate sunlight.

These trees often can be pruned back and restored to a point where quality fruit may be obtained once again. It may require several years to restore …

Pb1764-Managing Pests In Childcare Facilities, The University Of Tennessee Agricultural Extension Service

Insects, Pests, Plant Diseases and Weeds

Everyone agrees it is important to protect children and childcare workers from needless contact with products used to manage pests. It is equally as important to make sure children and workers are not harmed or made sick by coming in contact with pests. For example, many people do not know that cockroaches can make people sick. German cockroaches are the most common pests in kitchens. They, along with flies and other pests, can spread germs that can cause food poisoning. Cockroaches can even cause someone with asthma to have an attack. Mosquitoes, ticks, rodents and birds can transfer organisms that …

An Anaerobic Methane Oxidizing Community Of Anme-1b Archaea In Hypersaline Gulf Of Mexico Sediments, Karen Lloyd, Laura Lapham, Andreas Teske

Microbiology Publications and Other Works

Sediments overlying a brine pool methane seep in the Gulf of Mexico (Green Canyon 205) were analyzed using molecular and geochemical approaches to identify geochemical controls on microbial community composition and stratification. 16S rRNA gene and rRNA clone libraries, as well as mcrA gene clone libraries, showed that the archaeal community consists predominantly of ANME-1b methane oxidizers; no archaea of other ANME subgroups were found with general and group-specific PCR primers. The ANME-1b community was found in the sulfate-methane interface, where undersaturated methane concentrations of ca. 100 to 250 _M coexist with sulfate concentrations around 10 mM. Clone libraries of …

Third Thursday 11-2006, Institute Of Agriculture

Third Thursday

No abstract provided.

Pb1766 Saving Trees And Making Money In Residential Development, The University Of Tennessee Agricultural Extension Service

Forestry, Trees, and Timber

It’s a common sight in developments that are 3 – 5 years old. A homeowner had initially purchased a property for its wooded and natural aesthetic appeal and thinks he or she has succeeded in preserving this beauty. When the home is finished and the nearby trees still cast shade, the owner considers the trees to be past the critical stage. It isn’t until after the interior is furnished and the lawn is established that the homeowner soon notices he or she is picking up a few more fallen branches in the yard than is customary. Eventually, the owner looks …

Sp683 Tree Wounds - Response Of Trees And What You Can Do, The University Of Tennessee Agricultural Extension Service

Forestry, Trees, and Timber

Trees are commonly wounded and the causes are many: broken branches; impacts, abrasions and scrapes; animal damage; insect attack; fire; etc. Wounds usually break the bark and damage the food- (phloem or inner bark) and water- (xylem or wood) conducting tissues. Wounds also expose the inside of the tree to organisms, primarily bacteria and fungi that may infect and cause discoloration and decay of the wood. Decay can result in structurally weakened tree stems and unsightly trees and can shorten the life of a tree. Decay in a tree cannot be cured. However, proper tree care can limit the progress …

Sp682 Watering Trees, The University Of Tennessee Agricultural Extension Service

Forestry, Trees, and Timber

Water is the most limiting factor for tree survival and growth. Trees use water during photosynthesis and lose water during transpiration. Water shortages affect both young and old trees. Drought conditions can lead to tree decline, making the tree more susceptible to pest problems. Supplemental watering can greatly assist trees during stressful drought periods in the summer and in the dormant season when soil moisture is limited. Desiccating winds and lack of precipitation can increase transpiration in evergreens (conifers) and create soil moisture deficits even during the winter.

Sp684 Selecting A Tree-Care Company, The University Of Tennessee Agricultural Extension Service

Forestry, Trees, and Timber

Choosing a tree-care company is similar to choosing most any professional service. The people performing the work must be knowledgeable, properly equipped, safetyconscious and have the experience to perform the service. Outlined below are a few questions that will help the informed consumer select a tree-care company and expect quality work at a reasonable cost.

Sp686 Dieback And Decline Of Trees, The University Of Tennessee Agricultural Extension Service

Forestry, Trees, and Timber

Tree decline is a general loss of vitality throughout the entire tree caused by a systemic disease or by a sequence of stressing events that causes the tree to deplete its energy reserves. Twig and branch dieback is initiated in the tree as a response to poor growing conditions, physical injury to the tree and/or pest attack. Usually a combination of physical, climatic and pest problems lead to decline and dieback of trees. The factors that contribute to this decline are the subject of this publication, as well as management practices to prevent decline.