Life Sciences Commons^™

Assessing The Functional Similarity Of Native And Invasive Anolis Lizards In The Food Webs Of Structurally-Simple Habitats In Florida, Nathan W. Turnbough

Doctoral Dissertations

Invasive species often displace ecologically-similar native species, but the extent to which invading and displaced species function similarly in the food web processes of invaded communities is largely unknown. I investigated whether populations and individuals of an invasive Anolis lizard (the brown anole, Anolis sagrei) and the native congener it displaces in Florida (the green anole, Anolis carolinensis) are functionally equivalent in the food webs of open and structurally-simple habitats. In a system of invaded and uninvaded dredge-spoils islands, I found that both arthropod communities and winter bird communities covaried with brown anole abundance (and therefore the identity …

Ecology Of Organohalide-Respiring Dehalococcoides Mccartyi: Corrinoid Cofactor-Related Community Interactions And Controls Over Strain Selection, Burcu Şimşir

Doctoral Dissertations

Organohalides such as tetrachloroethene (PCE) and trichloroethene (TCE) are among the most prevalent toxic groundwater contaminants. Remediation of organohalide-contaminated sites has high priority, and efficient and cost-effective remedies are needed to prevent environment and human exposure through contaminated water. Bacterial organohalide-respiration plays a major role in organohalide detoxification. Dehalococcoides mccartyi (Dhc) are key mediators in bioremediation, since only Dhc strains have been documented in complete detoxification of chlorinated ethenes to benign ethene. Dhc depends on other microorganisms in the environment for essential growth requirements (e.g., hydrogen and vitamins). For successful implementation of the reductive dechlorination to remediate contaminated …

Antibacterial Activity And Chemical Characterization Of Resin From Sciadopitys Verticillata (Thunb.) Siebold And Zuccarini, David Ira Yates

Doctoral Dissertations

Sciadopitys verticillata produces white viscous resin that is unique among the conifers. This research investigated effects of resin on bacteria from different ecological niches and the chemical composition of the resin. Each bacterial species was evaluated separately for response to winter- and summer-collected resins. Exposure to winter-collected resin reduced numbers of colonies of Bacillus cereus, Erwinia amylovora, Agrobacterium tumefaciens, and Escherichia coli and increased numbers of Xanthomonascampestris, Pseudomonas fluorescens, and Pseudomonas syringae. Summer-collected resin affectedpopulation growth of two bacterial species; population counts of E. amylovora decreased and those of P. fluorescens increased. Selected strains of …

Bioremediation Of Chlorinated Ethenes: Ph Effects, Novel Dechlorinators And Decision-Making Tools, Yi Yang

Doctoral Dissertations

Chlorinated solvents have been widely used in different areas of modern society. Usage of these chlorinated solvents was not necessarily accompanied with proper handling and disposal of these hazardous compounds, which caused a variety of environmental problems and continues to affect human health. Remediation of chlorinated ethenes contaminated sites has high priority for state regulators and site owners. Among the available treatment technologies, bioremediation shows great promise as a cost-effective corrective strategy for a variety of environmental pollutants. Prerequisites are that the microbiology involved in contaminant degradation and geochemical factors, such as pH, are understood, so that bioremediation technologies can …

Towards Understanding Osmolyte Effects On Folate(S) And Dihydrofolate Reductase Proteins, Purva Prashant Bhojane

Doctoral Dissertations

Osmolytes are small molecules that alter water activity and probe role of water in biological processes. Osmotic stress approach explored the role of water in ligand binding to dihydrofolate reductase (DHFR). DHFR catalyzes NADPH dependent reduction of dihydrofolate (DHF) to tetrahydrofolate (THF), which is essential for the synthesis of DNA, amino acids and other metabolic intermediates. R67 DHFR is a plasmid-encoded DHFR that confers resistance against trimethoprim, which is a potent inhibitor of E.coli chromosomal DHFR.

Osmolytes addition decreases the affinity of the substrate towards both the DHFRs. Weak preferential interactions between the osmolytes and DHF impede substrate binding to …

Utilizing Cover Crops To Improve Sustainability Of Conventional Weed Management Programs, Garret Brown Montgomery

Doctoral Dissertations

Research was conducted from the fall of 2014 to the fall of 2016 to evaluate the optimal utilization of cover crops for weed control in no-till environments. Studies included a corn (Zea mays L.) termination timing study to evaluation different termination intervals of cereal rye (Cereal rye L.), hairy vetch (Vicia villosa Roth.), and a combination of cereal rye and hairy vetch cover crops on corn growth and development, an evaluation of a roller crimper for cover crop termination prior to corn study, an evaluation of a roller crimper for cover crop termination prior to soybeans [ …

Improved Fungicidal Control Of Large Patch Through Optimal Use Of Surfactants And Spray Rate Volume, Jesse J. Benelli

Doctoral Dissertations

Large patch (Rhizoctonia solani AG 2-2LP) epidemics cause significant damage to Japanese lawngrass (JLG; Zoysia japonica) in the transition zone. Large patch primarily affects the stems and sheaths of JLG and is difficult to control using traditional fungicide sprays. Field and growth chamber experiments were conducted during 2015-2016 in TN and GA to evaluate methods to enhance fungicidal control of large patch in JLG landscapes. The 1^st experiment evaluated the most critical application target site that resulted in the greatest amount large patch control. In this experiment, four fungicides (azoxystrobin, flutolanil, tebuconazole, and chlorothalonil) were dispensed as …

Molecular And Ecological Aspects Of The Interactions Between Aureococcus Anophagefferens And Its Giant Virus, Mohammad Moniruzzaman

Doctoral Dissertations

Viruses are increasingly being recognized as an important biotic component of all ecosystems including agents that control the rapid ecological events that are harmful algal blooms (HABS). Aureococcus anophagefferens is a pelagophyte which causes recurrent ecosystem devastating brown tide blooms along the east coast of the USA and has recently spread to China and South Africa. It has been suggested that a large virus (AaV) is possibly an important agent for demise of brown tide blooms. This observation is consistent with the recognition of a number of other giant viruses modulating algal blooms in marine systems. In this dissertation, we …

Spatial Crowding And Confinement Effects On Bursty Gene Expression, Charles Wei-Shing Chin

Doctoral Dissertations

Synthetic biology and genetic engineering are valuable tools in the development of new, sustainable energy generation technologies. The characterization of stochastic gene expression is vital to the efficient application of genetic engineering techniques. Transcriptional bursting, in which periods of high expression are punctuated by periods of no expression, is extensively observed in gene expression. While various molecular mechanisms have been hypothesized to be responsible for transcriptional bursting, spatial considerations have largely been neglected. This work uses computational modeling to examine in detail the influence of spatial factors such as macromolecular crowding and confinement on gene expression.

In the first part …

Exploring Enrichment Cultures Of Denitrifying Microorganisms From El Yunque National Forest, Samiha Ahsan, Jenny Onley, Frank Loeffler

Chancellor’s Honors Program Projects

No abstract provided.

The Impact Of Stability Ball Seating On Behavior And Academic Achievement Among Elementary School Students In Grades 1 Through 4., Sheila R. Borders

Doctoral Dissertations

This study was designed to answer three questions: 1) What is the impact of stability ball seating on the behavior of students in grades 1 through 4? 2) What is the impact of stability ball seating on the mathematics scores of students in grades 1 through 4? and 3) What is the impact of stability ball seating on the reading scores of students in grades 1 through 4? Research has shown that stability ball seating is linked to behavior and academic achievement among students diagnosed with attention deficit hyperactivity disorder (ADHD) and/or autism spectrum disorder (ASD). This study examines the …

Cohesion Without Cohesins In Drosophila Meiosis, Avik Mukherjee

Doctoral Dissertations

Meiosis is essential for sexual reproduction. The proper segregation of chromosomes in meiosis requires multiple functions of a multi-subunit protein complex known as cohesin. Cohesin forms a ring around duplicated sister chromatids and prevents them from separating prematurely. In Drosophila, mitotic cohesin is composed of four subunits: SMC1 and SMC3 and SCC1/RAD21 and SCC3/SA and are required for mitotic cohesion. However, RAD21 is dispensable for meiotic cohesion and although SMC1 and SMC3 are present on meiotic centromeres and on synapsed chromosome arms, as expected, their functions in meiosis remain poorly characterized. Moreover, unlike in other eukaryotes in which screens for …

Whole Genome Sequencing As A Tool For Identifying Phenotypic Properties And Underlying Genetic Mechanisms In Staphylococcus Pseudintermedius, Matthew C. Riley

Doctoral Dissertations

Staphylococcus pseudintermedius is a Gram-positive bacterial opportunistic pathogen commonly associated with dermal infections in canines, but capable of causing serious disease in other species. Reports of human infections caused by S. pseudintermedius along with an increase in resistance to multiple antibiotics highlights the importance of this organism. Whole genome sequencing can allow large scale investigation of genetic mechanisms underlying phenotypic properties that contribute to the expansion of successful S. pseudintermedius clonal lineages.

The increase in multidrug and methicillin-resistant S. pseudintermedius (MRSP) may result from horizontal transfer of genetic material between bacterial isolates, yet is thought to be rare in Staphylococci …

Tetrameric Photosystem I: From Initial Discovery And Characterization In Chroococcidiopsis Sp. Ts-821 To Exploration Of Its Distribution And Understanding Of Its Significance In Cyanobacteria, Meng Li

Doctoral Dissertations

Photosystem I (PSI) forms trimeric complexes in most characterized cyanobacteria. We had reported the tetrameric form of PSI in the unicellular cyanobacterium, Chroococcidiopsis sp. TS-821 (TS-821). Using Cryo-EM, a 3D model of the PSI tetramer structure at 11.5 [Angstrom] resolution was obtained and a 2D map within the membrane plane of at 6.1 [Angstrom]. In contrast to the three-fold symmetry in trimeric PSI crystal structure from T. elongatus, two different inter-monomer interactions involving PsaLs are found in the PSI tetramer. Phylogenetic analysis based on PsaL protein sequences shows that TS-821 is closely related to heterocyst-forming cyanobacteria. Additionally, this tetrameric …

Microbial Respiration And Community Response To Crude Oil In Deep Eastern Mediterranean And The Great Australian Bight, Jiang Liu

Doctoral Dissertations

The Deep Water Horizon (DWH) oil spill in 2010 was the largest deep ocean oil spill in world history. Very limited information about oil biodegradation is available in deep oceans other than GOM since DWH. In this study, we investigate the microbial communities’ response to crude oil contamination in the deep Eastern Mediterranean sea (E.Med) and Great Australian Bight (GAB). In addition, we will assess feasible methods for oil bioremediation in those locations.

First, we discovered the fast adaption of the E.Med deep water microbial community to oil contamination in terms of phylogeny and functional genes. Based on the 16S …

On The Quantification Of Complexity And Diversity From Phenotypes To Ecosystems, Zachary Harrison Marion

Doctoral Dissertations

A cornerstone of ecology and evolution is comparing and explaining the complexity of natural systems, be they genomes, phenotypes, communities, or entire ecosystems. These comparisons and explanations then beget questions about how complexity should be quantified in theory and estimated in practice. Here I embrace diversity partitioning using Hill or effective numbers to move the empirical side of the field regarding the quantification of biological complexity.

First, at the level of phenotypes, I show that traditional multivariate analyses ignore individual complexity and provide relatively abstract representations of variation among individuals. I then suggest using well-known diversity indices from community ecology …

Crop Tree Enhancement Of Green Ash (Fraxinus Pennsylvanica) In A West Tennessee Hardwood Bottom, John Luke Bowers

Masters Theses

Crop tree enhancement is a forest management technique undertaken to maintain, enhance, and improve the species composition, growth rate, and stem quality of stands so that management objectives may be better and more quickly accomplished. In 1996, a crop tree enhancement study involving green ash (Fraxinus pennsylvanica) in a 16-year-old, naturally regenerated, mixed-species, pole-sized, bottomland hardwood stand was initiated at Ames Plantation in West TN. Treatments included a crown-touching release, a crown-touching release plus one-time fertilizer application, and a control, applied in a randomized block design with five 25-crop tree repetitions of the three treatments. Initial crop tree …

Comparison Of Mesophyll Protoplast Isolation And Transformation Between Panicum Virgatum And Panicum Hallii, Andrea Grace Collins

Masters Theses

Protoplasts are appropriate targets for genome editing, DNA functional screens and transgenesis. This project focuses on the comparison of inexpensive mesophyll protoplast isolation via the use of food-grade enzymes and transformation between diploid Panicum hallii Vasey (PAH) and polyploid cellulosic feedstock Panicum virgatum L (switchgrass), a relative of PAH. PAH has great potential as a C4 model species for crop and bioenergy research. Here an inexpensive switchgrass and PAH mesophyll protoplast isolation and transformation system was developed; the first protoplast system for PAH. Using low-cost commercial food-grade enzymes, a cost reduction of ~1000-fold was achieved compared to traditional protoplast isolating …

Reasons Youth Choose Or Do Not Choose To Be Involved In 4-H Livestock Projects In Tennessee, Leigh Erin Fuson

Masters Theses

The purpose of this study was to find reasons youth choose or do not choose to be involved in 4-H livestock projects. Livestock projects are an important part of 4-H youth development because they teach life skills like responsibility and hard work. However, many youth are unable to participate or do not have the interest. This study sought to discover what motivates some youth to become involved in a livestock project and why others do not.

Focus groups were used as the data collection tool. Two groups of youth livestock participants and two groups of non-livestock participants were utilized. Themes …

Characterization Of Fusarium Species And Alternaria Alternata, And Their Effects On Switchgrass Health And Chemical Components, Sara Beth Collins

Masters Theses

Panicum virgatum L., readily referred to as Switchgrass, is a perennial warm-season bunch grass, used as an alternative energy source for biofuel production. There is insufficient research on switchgrass pathogens, and is expected that an increase in disease pressure will result as more land is reserved for this perennial crop. The purpose of this research was to identify and characterize pathogenic Alternaria alternata and Fusarium species on Switchgrass (Panicum virgatum L.), and to evaluate their impact on stand establishment and plant health. Molecular identifications of fungal isolates obtained from infected commercial switchgrass seed yielded eight species (A. alternata, …

Beneficial Effects Of Naringenin And Indomethacin On White And Brown Adipocytes, Jamie Ann Kearns

Masters Theses

As obesity continues to grow and medical costs in the United States are estimated at $147 billion annually, novel ways to prevent and treat obesity are needed. One approach is to promote thermogenesis to improve energy balance by increasing the activities of thermogenic brown and beige adipocytes.

Naringenin, a citrus flavanone, has been shown to act as anti-inflammatory and lipid lowering agent as well as activate PPARgamma. However, it is unclear whether it can activate thermogenic activity in white adipocytes, i.e., promote formation of beige adipocytes. Indomethacin (INDO) is an FDA approved drug used to treat pain related to inflammation …

A Population Genetics Study Of Discula Destructiva, The Causal Agent Of Dogwood Anthracnose, Kristie Lynn Mantooth

Masters Theses

Flowering dogwood (Cornus florida L.) is prized as an ornamental and contributes millions of dollars to the economy through tourism and sales each year. Dogwood anthracnose, caused by Discula destructiva Redlin, was observed in the late 1970s on the east and west coasts of the United States and by 1991 had quickly spread throughout much of the native ranges of C. florida and C. nuttalli. The objectives of this study were to investigate the genetic diversity and population structure of D. destructiva using simple sequence repeats (SSRs), and to test the cross-transferability of these markers to other Discula …

Rapid Molecular Detection And Population Genetics Of Pityophthorus Juglandis, A Vector Of Thousand Cankers Disease In Juglans Spp., Emel Oren

Masters Theses

Thousand Cankers Disease (TCD) is a disease complex involving the fungal pathogen Geosmithia morbida, an insect vector Pityophthorus juglandis, and the hosts, Juglans spp. and Pterocarya spp. Signs and symptoms of TCD include crown thinning due to branch dieback, yellowing and wilting of the leaves, appearance of epicormic shoots, numerous entrance/exit holes, gallery formation by P. juglandis, and the development of small, dark brown cankers underneath the bark. TCD originally described from western U.S., has now expanded to eastern U.S. and northwestern Italy. The disease complex is often difficult to diagnose due to the absence of symptoms …

Effect Of Omega-3 Polyunsaturated Fatty Acid (N-3 Pufa) Supplementation To Lactating Sows On Growth And Indicators Of Stress In The Post-Weaned Pig, John M. Mcafee

Masters Theses

The first experiment was designed to determine the concentration of protected fish oil product (PFO), as Gromega^TM, to be added that would sufficiently decrease the polyunsaturated fatty acid (PUFA) ratio in the sows’ milk and colostrum. Of the 3 diets tested (0.25%, 0.5% and 1%) with a control (0% PFO), only the 1% PFO diet had an effect on the PUFA concentrations. The docosahexaenoic acid (DHA) concentration tended (P = 0.05) to be greater in the 1% PFO diet for both colostrum and milk samples. A second experiment was designed to …

Intercanine Distance Used As A Measure To Rule Out Biters In Bite Mark Forensics, Alana Joy Scudiere Ohana

Masters Theses

The science of identification by bite mark analysis has recently been called into serious question. (Reesu and Brown 2016) Human dentition is truly variable, but often not unique. When animal bites are considered, a proper ID of the perpetrator is nearly impossible. Primary distortion (when the bite is made) and secondary distortion (during decomposition or healing) both further disrupt landmarks that might be used for identification. (Sheasby and MacDonald 2001) Using only ink marks and intercanine distance on live subjects, this study attempts to determine maximum distortion possible for a variety of bite mark locations on skin. (Pretty and Sweet …

Follicular Dynamics In Insulin Resistant Mares, Julio Cesar Prado

Masters Theses

Obesity and insulin resistance have been linked to prolonged interovulatory period, aberrations in the estrous cycle, and continuous reproductive activity during the non-breeding season. EMS has been determined to influence the intrafollicular environment of mare ovaries. In humans, insulin resistance has been linked to polycystic ovaries as part of Polycystic Ovarian Syndrome (PCOS). A study was conducted to determine 1) the impact of insulin resistance on follicle growth and size at ovulation, and 2) whether predicted ovulatory follicles respond to hCG administration in Insulin-resistant (IR) mares. Mares were selected for the study based on insulin sensitivity and separated into an …

Effects Of Wider Step Width On Knee Biomechanics In Obese And Healthy-Weight Participants During Stair Ascent, Derek Scott Yocum

Masters Theses

An increased likelihood of developing obesity-related knee osteoarthritis may be associated with increased peak internal knee abduction moment. Increases in step width may act to reduce this moment. This study focused on how step width influenced the knee joint during stair ascent by healthy and obese participants. Participants ascended stairs while walking at their preferred speed and under one of two step width conditions – preferred and increased. Obese participants experienced greater mediolateral and vertical ground reaction forces (GRFs), as well as increased peak knee extensor moments and push-off peak internal knee adduction moments. The findings of this study indicate …

Lignin Maximization: Analyzing The Impact Of Different Feedstocks And Feedstock Ratios Using Organosolv Fractionation, Marc Banholzer

Masters Theses

Over-exploitation of fossil fuels coupled with increasing pressure to reduce carbon emissions are prompting a transition from conventional petrochemical feedstocks to sustainable and renewable sourced carbon. The use of lignocellulosic biomass as a feedstock for integrated biorefining is of current high interest, as separation into its component parts affords process streams of cellulose, hemicellulose and lignin, each of which can serve as a starting point for the production of biobased chemicals and fuels. Given the large number of potential sources of lignocellulosic feedstocks, the biorefinery will need to adapt to the supplies available over a normal growing season. Of particular …

Effect Of Varying Rumen Degradable And Undegradable Protein On Milk Production And Nitrogen Efficiency In Lactating Dairy Cows Under Summer Conditions, Jeffrey D. Kaufman

Masters Theses

The objective is to determine the effect of reducing nitrogen input through feeding low rumen degradable protein (RDP) and rumen undegradable protein (RUP) proportions on milk production, nitrogen efficiency and metabolism in heat-stressed cows. Forty-eight mid-lactating, Holstein cows were assigned to treatments using a randomized block design in a 2x2 factorial arrangement of treatments (n = 12/treatment). Treatments included two levels of RDP (10 and 8%) and two levels of RUP (8 and 6%). From d 1 to 21, a common diet (10% RDP-8% RUP) was fed to cows followed with their respective treatment diets fed from d 22 to …

Understanding Stakeholder Attitudes And Involvement In Habitat Conservation Plans And The Endangered Species Act, Kyle Andrew Rodgers

Masters Theses

The Endangered Species Act (ESA), established in 1973, was a landmark piece of environmental legislation and remains the standard for endangered species conservation. Implementation of the ESA has often been framed as pitting economic development against species conservation, inciting passions for and against endangered species conservation. The strength of opposing public opinions is highlighted by high-profile controversies such as those around the snail darter, northern spotted owl and the greater sage grouse. In an attempt to reduce conflict, the US Fish and Wildlife Service (USFWS) increasingly seeks to utilize collaborative, stakeholder-based processes that address stakeholder interests, attitudes, and values.

In …