Life Sciences Commons^™

Exploring Patterns Of Genetic Diversity Of A Malagasy Ant Species: Anochetus Madagascarensis, Nicole Annette Lewis

Electronic Theses and Dissertations

Madagascar is extremely diverse and imperiled. Close to 90% of all land dwelling species are endemic to Madagascar (plants, reptiles, mammals and amphibians). Understanding patterns of genetic diversity for species can aid in better conservation efforts. In this study, I focus on the endemic Malagasy ant species, Anochetus madagascarensis. By employing a broad geographic sample of this species from throughout its distribution and a multilocus genetic data set, I explored population structure and historical factors that affected these patterns. I tested hypotheses proposed to be responsible for generating population structure, and by extension the process of speciation in Madagascar, including …

Ectomycorrhizal Fungal Succession In A Native Monterey Pine Forest And Its Potential Influence Upon Forest Population Dynamics, Kristopher Jordan Hennig

Electronic Theses and Dissertations

Ectomycorrhizal fungi are plant symbionts influential to the growth and survival of many plant species found within forest ecosystems throughout the globe. The succession of ectomycorrhizal communities during forest maturation has been observed in a number of systems; however, though it is generally assumed that this process is important for forest dynamics, we do not fully understand the causes of succession and whether it strongly influences metrics of plant population dynamics such as population growth rates or size class structure. I studied a secondary successional chronosequence to test the hypothesis that ectomycorrhizal fungal succession occurs within a native Monterey pine …

Molecular Details Of The Catalytic Activity Of Carboxylesterases, Xiaozhen Yu

Electronic Theses and Dissertations

Carboxylesterases (CEs; EC 3.1.1.1) are ubiquitous enzymes responsible for the detoxification of xenobiotics. CEs hydrolyze carboxyl esters into their corresponding alcohol and carboxylic acid. Because of their biological functions, especially their roles in converting inactive prodrugs, such as the anti-cancer drug CPT-11, to their active metabolites, a good understanding of the mechanism of the hydrolysis reaction will give us a better direction for drug design. In this study, we used a multidisciplinary approach (computational simulation, molecular biology techniques and enzyme kinetic methods) to study the dynamic motions of CEs and the potential role of these motions in the catalytic mechanism …

Influence Of Vegetation On Sediment Bacterial Community Structure, Microbial Enzyme Activities And Phosphorus Retention In Constructed Freshwater Wetlands, Rani Menon

Electronic Theses and Dissertations

Agricultural activities are major sources of non-point pollutants causing eutrophication. Constructed wetlands are used as a best management practice for sequestration of nutrients from agricultural runoff. This dissertation focuses on the influence of vegetation on bacterial community structure, microbial enzyme activities, and phosphorus retention capacity of constructed wetland systems. A greenhouse experiment was conducted using unvegetated or vegetated mesocosms with Juncus effusus, Carex lurida or Dichanthelium acuminatum var. acuminatum in monoculture or mixed culture.

To study the influence of vegetation on the bacterial community structure and microbial enzyme activities, sediment samples were taken from monoculture mesocosms in the greenhouse. β-1,4-glucosidase, …

Nutrition Assessment And Intervention Improves Body Composition And Diet In Ncaa Female Volleyball Players, Rachel Wenzel

Electronic Theses and Dissertations

Intercollegiate volleyball is a powerful sport that consists of two to three hour matches; therefore, optimal physical condition is critical for top performance. This study assessed nutrition and anthropometric parameters at the start and conclusion of both the spring 2009 (no intervention) and spring 2010 (intervention) off-seasons as well as additional measurements four months after the intervention. The subject' body composition, total energy, carbohydrate and protein needs were calculated and intakes were assessed. The intervention consisted of monthly individual nutrition counseling sessions based on analysis of intake from three-day food records. Food records were analyzed using Nutrient Data System for …

Relationship Between Coastal Vegetation Biomass With Elevation And Salinity Gradients, Ying Chen

Electronic Theses and Dissertations

Surges and waves generated by hurricanes and other severe storms can cause devastating damage to property and loss of life in coastal areas. Vegetation in wetlands and coastal fringes can reduce storm surges and waves while complementing traditional coastal defense approaches such as permanent levees, seawalls and gates. The effectiveness of marsh vegetation in attenuating storm surge energy and reducing soil erosion depends on the level of primary production at the time of the storm surge and the ability of marsh vegetation to recover rapidly from damage caused by the storm surge. Marsh production depends on a variety of abiotic …

Development Of Molecular And Cellular Imaging Tools To Evaluate Gene And Cell Based Therapeutic Strategies In Vivo, Jixiang Xia

Electronic Theses and Dissertations

Molecular imaging modalities are important tools to evaluate the efficacy of gene delivery systems and cell-based therapies. Development and application of these modalities will advance our understanding of the mechanism of transgene expression and cell fate and functions. Physical gene transfer methods hold many advantages over viral vectors among gene therapeutic strategies. Here, we evaluated the efficacy of biolistic (“gene gun”) gene targeting to tissues with non-invasive bioluminescence imaging (BLI) methods. Plasmids carrying the firefly luciferase reporter gene were transfected into mouse skin and liver using biolistics, and BLI was measured at various time points after transfer. With optimized DNA …

Biology, Ecology And Control Of The Invasive Channeled Apple Snail, Pomacea Canaliculata, Christina M. Trexler

Electronic Theses and Dissertations

Invasive species are detrimental to native biotas worldwide. Recently, Florida was invaded by a freshwater snail (Pomacea canaliculata) native to Argentina. This snail is a serious pest of rice crops in Asia, but little is known about its interactions within Florida ecosystems. Possible competitive exclusion of the native congener (P. paludosa) is a concern because it is the almost exclusive prey of the federally endangered Everglades snail kite (Rostrhamus sociabilis). My research consisted of three parts. First, to identify possible methods to control P. canaliculata in the egg stage, I experimentally evaluated the effects of photoperiod, substrate availability, and food …

The Innate Anti-Hiv-1 Activity Of Human Seminal Plasma, Julie A. Martellini-Moore

Electronic Theses and Dissertations

Human immunodeficiency virus (HIV) has become a global pandemic over the past few decades, with new infections and related deaths in the millions each year. There is no cure in sight for HIV-1 infection, and there has been little progress in developing an efficacious vaccine. Heterosexual transmission of HIV-1 remains the principal mode of transmission throughout the world and thus measures, such as topical vaginal microbicides, to prevent infection of the female reproductive tract are actively being explored. Recent trials of topical vaginal microbicides have shown that their interaction with the mucosal surfaces of the female reproductive tract as well …

Variability Of Carbon Stock In Florida Flatwoods Ecosystems Undergoing Restoration And Management, Kathryn Elizabeth Becker

Electronic Theses and Dissertations

The global community is struggling with mitigating the effects of widespread habitat loss and degradation; the effects of which are being further magnified in the face of global climate change. Quality natural habitat is becoming increasingly limited and atmospheric carbon levels continue to rise. Therefore, land managers responsible for multiuse management are often faced with the dilemma of managing ecosystems for biodiversity, as well as optimizing ecosystem services such as carbon storage and sequestration. However, some management techniques used to meet these objectives may yield conflicting results, specifically, the management tool of prescribed fire. Fire is crucial in maintaining species …

Surface Entropy Reduction To Increase The Crystallizability Of The Fab-Rna Complex, Priyadarshini Palaniandy Ravindran

Electronic Theses and Dissertations

Crystallizing RNA has been an imperative facet and a challenging task in the world of RNA research. Assistive methods such as Chaperone Assisted RNA Crystallography (CARC), employing monoclonal antibody fragments (Fabs) as crystallization chaperones have enabled us to obtain RNA crystal structures by increasing the crystal contacts and providing initial phasing information. Using this technology the crystal structure of [delta]C209 P4-P6 RNA (an independent folding domain of the self-splicing Tetrahymena group I intron) complexed to Fab2 (high affinity binding Fab) has been resolved to 1.95 Å (1). Although the complexed class I ligase ribozyme has also been crystallized using CARC …

Applications Of Airborne And Portable Lidar In The Structural Determination, Management, And Conservation Of Southeastern U.S. Pine Forests, Claudia De Mendonca Costa Synek Listopad

Electronic Theses and Dissertations

Active remote sensing techniques, such as Light Detection and Ranging (LiDAR), have transformed the field of forestry and natural resource management in the last decade. Intensive assessments of forest resources and detailed structural assessments can now be accomplished faster and at multiple landscape scales. The ecological applications of having this valuable information at-hand are still only being developed. This work explores the use of two active remote sensing techniques, airborne and portable LiDAR for forestry applications in a rapidly changing landscape, Southeastern Coastal Pine woodlands. Understanding the strengths and weaknesses of airborne and portable LiDAR, the tools used to extract …

Response Of Riparian Plant Communities To Hydrological Alteration: Are Seed Banks A Means Of Restoration?, Siobhan Boyer Gorham

Electronic Theses and Dissertations

The effects of anthropogenic modifications of stream systems on in situ plant community composition and seed bank composition were examined at five riparian sites in the Yazoo River watershed in northern Mississippi. This analysis was performed to determine if the soil seed bank can provide a means for the restoration of riparian floodplain plant communities. The study sites represented five different kinds of hydrological alteration: a highly incised riparian terrace isolated from the stream channel, a deforested original stream with reduced flow due to channelization and standing water due to levees, a forested original stream with reduced flow due to …

Conservation Genetics And Distribution Of The Yazoo Darter (Etheostoma Raneyi), Kenneth Alan Sterling

Electronic Theses and Dissertations

The Yazoo Darter is a range-restricted endemic fish in north-central Mississippi. Because the limited and fragmented range of this species puts it at risk of extinction, the Yazoo Darter has been classified as vulnerable or sensitive by several agencies and conservation organizations. However, the actual conservation status of this species is uncertain. Information necessary for conservation management is relatively sparse and is scattered among published and unpublished sources, particularly collection records. I have consolidated all known collection records for this species into a standardized database which has not only yielded valuable information presented here, but will provide a resource for …

Cross-Validation Of A Recently Published Equation Predicting Energy Expenditure To Run Or Walk A Mile In Normal Weight And Overweight Adults, Cody Edward Morris

Electronic Theses and Dissertations

An equation recently published by Loftin, et al. (2010) was cross-validated using 30 subjects consisting of 10 normal weight walkers, 10 overweight walkers, and 10 distance runners. Gender was balanced across sub-groups. Participants walked or ran for 5 minutes at their preferred pace. Preferred walking pace was determined by six timed 50-ft trials and preferred running pace by the runner's typical training pace. Energy expenditure (EE) was determined via indirect calorimetry and reported in absolute units (kcal), and corrected to a mile distance. Body composition was assessed via DXA. EE per mile was predicted using the Loftin, et al. (2010) …

Population Biology Of A Coastal Dune-Dwelling Spider (Arctosa Sanctaerosae) Along The Hurricane Disturbed Northern Gulf Of Mexico Coast, Robert A. Hataway

Electronic Theses and Dissertations

With the continued increase in the number of tourists visiting the Northern Gulf coast in the last century and the resulting development of this coastline the habitat of Arctosa sanctaerosae has become fragmented; and the sprawl of large cities along the coast has further degraded available habitat. In addition to anthropogenic disturbance to this coastal region, hurricanes are an additional and natural perturbation to the ecosystem. This habitat has seen a number of major tropical storms over the last decade and I have sought to explore the impact of habitat destruction and storm-induced disturbance on a species of spider endemic …

The Effects Of Chronic Prophylactic Naproxen Sodium On Skeletal Muscle Adaptation To Resistance Exercise In Recreationally-Trained College-Aged Males, Christi Brewer

Electronic Theses and Dissertations

Resistance exercise causes exercise-induced muscle injury (EIMI), triggering an acute local inflammatory response associated with delayed-onset muscle soreness (DOMS). DOMS is characterized by a predictable discomfort and decreased level of muscle performance and is believed to be the product of both mechanical and inflammatory processes. From the latter perspective, non-steroidal anti-inflammatory drugs (NSAIDs) have been investigated for their potential to alleviate DOMS-associated symptoms. Such analgesics exert their effects by blocking the formation of prostaglandins; however, prostaglandins, specifically prostaglandin F 2?, also play an important role in skeletal muscle regeneration. While some have advocated the use of NSAIDs for the relief …

Effect Of Uv-A Irradiance On Lipid Accumulation In Nannochloropsis Oculata, Rathy Srinivas

Electronic Theses and Dissertations

The marine microalgae Nannochloropsis spp. are of both ecological and economic importance as they contribute to the base of the food chain of marine systems, and can accumulate a considerable amount of lipids. Their lipids can be grouped into two categories, storage lipids, which are mainly triglycerides (TGs), and structural lipids, which are composed of polyunsaturated fatty acids (PUFAs). PUFAs are essential nutrients for both aquatic animals and humans, while TGs can be transesterified to produce biodiesel. Lipid formation in microalgae depends on several environmental factors and Nannochloropsis spp. have been shown to accumulate excess storage lipids under stressful conditions. …

Epigenetic Effects Of Benzo(A)Pyrene In Fundulus Heteroclitus And Danio Rerio, Xiefan Fang

Electronic Theses and Dissertations

DNA methylation is one of the epigenetic mechanisms that controls gene expression and is vulnerable to early life environmental toxicant exposures. Our goal was to use two fish models, Fundulus heteroclitus and Danio rerio (zebrafish), to study the benzo(a)pyrene (BaP) effects on DNA methylation status and whether the alterations could contribute to BaP-mediated reproductive and developmental toxicities. Initially, we used Fundulus to study BaP effects on glycine N-methyltransferase (GNMT) expression throughout development. Fundulus embryos were exposed to waterborne BaP at nominally 10 or 100 μg/L and both GNMT mRNA expression and enzyme activity were measured. Quantitative PCR and whole mount …

Stable Expression Of Tuberculosis Vaccine Antigen In Lettuce Chloroplasts, Priya Saikumar Lakshmi

Electronic Theses and Dissertations

Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is one of the leading reasons of death by an infectious bacterial pathogen. The development of TB vaccines has been recognized as a major public health priority by the World Health Organization. In this study, a potential candidate antigen, ESAT-6 (6 kDa early secretory antigenic target) was fused with cholera toxin B subunit (CTB). Transplastomic lettuce plants were generated expressing these fusion proteins. Site-specific transgene integration into the chloroplast genome was confirmed by polymerase chain reaction and Southern blot analysis. In transplastomic leaves, expression levels of fusion protein (CTB-ESAT6) varied depending upon …

Evolutionary Relationships Among Staphylococci And The Prevention Of Staphylococcus Aureus Nasal Colonization, Ryan Paul Lamers

Electronic Theses and Dissertations

Staphylococcus is a significant cause of human infection and mortality, worldwide. Currently, there are greater than 60 taxa within Staphylococcus, and nearly all are pathogenic. The collective potential for virulence among species of Staphylococcus heightens the overall clinical significance of this genus and argues for a thorough understanding of the evolutionary relationships among species. Within Staphylococcus, aureus is the most common cause of human infection, where nasal carriage of this bacterium is a known risk factor for autoinfection. The predisposition to infection by nasal carriers of S. aureus, and the ease with which strains are transferred between individuals, suggests that …

Indirect Estimates Of Gene Flow And Its Conservation Implications In The Striped Newt (Notophthalmus Perstriatus), Sarah Elizabeth May

Electronic Theses and Dissertations

This study used indirect methods to estimate patterns of gene flow in a rare salamander species, the striped newt (Notophthalmus perstriatus). First, we used combined genetic and ecological methods to determine whether populations that appear to exist in two regions separated by 125 km, exhibited genetic and ecological distinctness such that the regions demarcate separate conservation units. Using mtDNA (cyt-b), we found that haplotypes were shared between localities within each region but none were shared between regions. Niche-based distribution modeling revealed significant differences in the ecological setting between the two regions. In combination, the absence of evidence for recent genetic …

The Effects Of Urbanization On Cypress (Taxodium Distichum) In Central Florida, Lisa A. Mccauley

Electronic Theses and Dissertations

Urbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of urbanization on cypress domes. Specifically, I tested how urbanization and its effects on fragmentation, hydrology, and fire regime) affected (a) the numbers and spatial pattern of cypress …

Synthesis, Characterization And Antibacterial Activity Of Silver Embedded Silica Nanoparticle/Nanogel Formulation, Roseline Menezes

Electronic Theses and Dissertations

The antibacterial property of silver (Ag) has been known since ancient time. It is reported in the literature that silver nanoparticles (AgNPs) exhibit improved antibacterial properties in comparison to silver ions of equivalent metallic Ag concentration. Such improvement in antibacterial activities is due to the high surface area to volume ratio of AgNPs (which facilitates interaction with the bacterial cells), increased release of silver ions and direct intra-cellular uptake of AgNPs leading to localized release of Ag ions. To date, over 300 consumer products containing AgNPs are available in the market and the inventory is rapidly expanding. The antibacterial efficacy …

Expression And Functional Evaluation Of Exendin 4 Fused To Cholera Toxin B Subunit In Tobacco Chloroplast To Treat Type 2 Diabetes, Ramya Nityanandam

Electronic Theses and Dissertations

The prevalence of type 2 diabetes has been steadily increasing around the globe. Glucagon like peptide (GLP-1), a powerful incretin increases insulin secretion in a glucose dependent manner. But GLP-1 is subjected to rapid enzymatic degradation (half-life: 2 min in circulation). The commercially available GLP-1 analog, exenatide has a longer half life with potent insulinotropic effects (about 2.4 hr) which requires cold storage and daily subcutaneous injections. In this study, exendin 4 (EX4), lizard derived GLP-1R agonist, was expressed as cholera toxin B subunit (CTB)-fusion protein in chloroplasts of tobacco to facilitate transmucosal delivery in the gut by utilizing the …

Expression Of Trichoderma Reesei Beta]-Mannanase In Tobacco Chloroplasts And Its Utilization In Lignocellulosic Woody Biomass Hydrolysis, Pankaj M. Agrawal

Electronic Theses and Dissertations

Lignocellulosic ethanol offers a promising alternative to conventional fossil fuels. One among the major limitations in the lignocellulosic biomass hydrolysis is unavailability of efficient and environmentally biomass degrading technologies. Plantbased production of these enzymes on large scale offers a cost effective solution. Cellulases, hemicellulases including mannanases and other accessory enzymes are required for conversion of lignocellulosic biomass into fermentable sugars. β- mannanase catalyzes endo-hydrolysis of the mannan backbone, a major constituent of woody biomass. In this study, man1 gene encoding β-mannanase was isolated from Trichoderma reesei and expressed via the chloroplast genome. PCR and Southern hybridization analysis confirmed the site-specific …

The Effects Of Seasonal Changes And Turbidity On Swimming Performance In White Crappie Pomoxis Annularis And Black Crappie Pomoxis Nigromaculatus., Caleb Joseph Gaston

Electronic Theses and Dissertations

Factors that affect swimming performance in fish can also affect fitness. I tested the effects of time of day, season and turbidity on swimming performance in black crappie Pomoxis nigromaculatus and white crappie Pomoxis annularis. These closely related fish co-occur and their relative abundance is thought to be governed by the levels of turbidity in the form of suspended sediments. Black crappie predominate in clear bodies of water and exhibited significantly greater critical swimming speeds in clear water than did white crappie during spring days and winter nights. A significant reduction in critical swimming speed was observed in black crappie …

Development And Evaluation Of Let's Eat Smart: A Pilot School-Based Nutrition Intervention For Elementry School Children In Kuwait, Sondos Ahmad Kalendar

Electronic Theses and Dissertations

Due to nutrition transition, the prevalence of childhood obesity is increasing significantly worldwide especially in affluent developing countries such as Kuwait. Obesity is associated with adverse chronic health conditions and financial burdens which provides an incentive for prevention. The objective of the study was to examine the effectiveness of a multi-component school-based nutrition intervention designed to improve healthy eating knowledge, attitudes, self efficacy and dietary behaviors among fourth and fifth graders in Kuwait. The Let's Eat Smart program was based on the social cognitive theory and used short interactive lessons, DVD sessions, posters, food models and parental letters to promote …

A Menu Analysis Of Sorority Meals At The University Of Mississippi, Jessica Lauren Moosa

Electronic Theses and Dissertations

Students transitioning to university life face numerous challenges including the problem of making healthy dietary choices. Sorority members are uniquely suited to examining dietary habits because of their access to regular planned meals and because of the social stresses they experience in regards to body image. Menus are not required to follow nutrient specific guidelines and the nutrient content of sorority meals has not been evaluated at the University of Mississippi. The purpose of this study is to analyze nutrient content of sorority meals and determine if members are able to obtain adequate amounts of nutrients from the foods offered. …

Impact Of Land Management On House Mice And Red Imported Fire Ants, Jesse R. Abelson

Electronic Theses and Dissertations

Understanding of mechanisms that limit the abundance and distribution of species is central to ecology. The failure of mechanisms to regulate populations can result in population outbreaks. There have been two outbreaks of house mice in the past decade in central Florida. In my study, I examine the efficacy of landscape management in the form of mowing and plowed soil barriers to limit or prevent outbreaks of house mice in a former agricultural area. House mouse populations were highly variable, but were unaffected by mowing or plowed soil barriers. Red imported fire ants were ubiquitous in the study area regardless …