Life Sciences Commons^™

Neuronal Calcium Regulation And Cellular Stress In A Malignant Hyperthermia Disease Model, Jason Santiago

Electronic Theses and Dissertations

Calcium ions (Ca2+) are essential signaling molecules and must be carefully regulated to preserve specificity in function. One indispensible Ca2+ signaling protein is the ryanodine receptor (RyR) calcium release channel. RyR1 is essential for muscle contraction, and RyR1mutations can lead to severe muscle disorders such as malignant hyperthermia (MH). Recently, a mouse model of human MH (Y522S-RyR1) has been developed. In skeletal muscle, Y522S-RyR1 exhibits an increased sensitivity to activation resulting in Ca2+ leak, mitochondrial disorganization, and cellular stress. Although RyR1 expression is limited in the brain, the cerebellum may be particularly vulnerable to this disease because RyR1 is highly …

The Influence Of Sexual Selection On Behavioral And Physiological Mechanisms Underlying Reproductive Success In Male Cape Ground Squirrels (Xerus Inauris), Mary Beth Manjerovic

Electronic Theses and Dissertations

Sexual selection is considered a powerful evolutionary force responsible for the enormous diversity found in reproductive morphology, physiology, and behavior. I addressed questions related to selection in the Cape ground squirrel (Xerus inauris), a species characterized as highly social and promiscuous. These attributes often are responsible for variance in male reproductive success and as such, sexual selection theory predicts increased opportunity for sexual selection. I confirm that the predominant mechanism underlying genital evolution and competition for paternity in X. inauris is sperm competition. I find evidence that investment in sperm competition is costly and may reflect immunocompetence. I quantify reproductive …

Mechanistic Importance Of Redox Potentials And Conformational Flexibility In Electron-Transferring Flavoproteins, Michael Anthony Swanson

Electronic Theses and Dissertations

The mitochondrial matrix flavoproteins electron transfer flavoprotein (ETF) and electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) are responsible for linking fatty acid β-oxidation with the main mitochondrial respiratory chain. Electrons derived from flavoprotein dehydrogenases are transferred sequentially through ETF and ETF-QO to ubiquinone and then into the respiratory chain via complex III. In this study, the effects of changes in ETF-QO redox potentials on its activity and the conformational flexibility of ETF were investigated.

ETF-QO contains one [4Fe-4S]^2+,1+ and one flavin adenine dinucleotide (FAD). In the porcine protein, threonine 367 is hydrogen bonded to N1 and O2 of the flavin ring …

Development Of Ultra-Sensitive Fluorescence Photoamplification Assays For The Detection Of Molecular Recognition Events, Tiffany Priscilla Gustafson

Electronic Theses and Dissertations

During the course of this research a novel method which couples the molecular recognition-triggered photoamplification chain in diaryl ketone adducts of dithiane with a "turn-off" or "turn-on" fluorescence-based assay for the detection of biological targets and ligands, regardless of their nature, through a molecular recognition event has been developed. This research has included several key steps, the most significant being: (1) the design of fluorophore adducts or dyads which recover fluorescence upon photocleavage for a "turn-on" assay and the identification of fluorophores which are quenched upon the photochemical release of a quencher for a "turn off" assay; (2) Optimization of …

Treefrog (Hyla Squirella) Responses To Rangeland And Management In Semi-Tropical Florida, Usa, Kathryn Windes

Electronic Theses and Dissertations

As urban areas expand, agricultural lands become increasingly important habitat for many species. Compared to some types of agricultural land-use, ranchlands provide vast expanses of minimally modified habitat that support many threatened and endangered species. Conservation biologists can promote ecologically sound management approaches by quantifying the effects of agricultural practices on resident species. I examined the effects of pasture management, cattle grazing, and landscape characteristics on both adult and larval treefrogs in a ranchland in south-central Florida. I experimentally determined optimal deployment of artificial treefrog shelters constructed of polyvinylchloride (PVC) pipe to efficiently sample adult treefrogs (Chapter 1). Seventy-two shelters …

Identification Of Novel Antimalarials From Marine Natural Products For Lead Discovery, Stephenie M. Alvarado

Electronic Theses and Dissertations

An estimated 500 million cases of malaria occur each year. The increasing prevalence of drug resistant strains of Plasmodium in most malaria endemic areas has significantly reduced the efficacy of current antimalarial drugs for prophylaxis and treatment of this disease. Therefore, discovery of new, inexpensive, and effective drugs are urgently needed to combat this disease. Marine biodiversity is an enormous source of novel chemical entities and has been barely investigated for antimalarial drug discovery. In an effort to discover novel therapeutics for malaria, we studied the antimalarial activities of a unique marine-derived peak fraction library provided by Harbor Branch Oceanographic …

Science Based Authentication Of Dietary Supplements: Studies On The Chemical Constituents, Analytical Method And Biological Activities Of Scutellaria Spp And Pfaffia Paniculata, Jing Li

Electronic Theses and Dissertations

During the last decade, the use of herbal medicine has expanded globally and gained popularity. With the tremendous expansion in the use of herbal medicine worldwide, safety and efficacy as well as quality control of herbal medicines have become more and more issues of concern for both health authorities and the public. Although herbal medicine has been in use for hundreds to thousands years, very limited science-based data exist to explicit its chemical constituents, pharmacological activities and toxicity. Therefore, lack of scientific evidence for herbal medicine usage elicits the need for systematic studies of herbal medicine, including phytochemical, analytical, and …

The Fungal Connection: Characterizing The Ectomycorrhizal Community And Belowground Response To Restoration Treatments In Northern Mississippi., Ashley Jane Craig

Electronic Theses and Dissertations

Ectomycorrhizal (ECM) fungi are symbionts on the roots of woody plant species throughout the world. These fungi provide plants with nutrients and are important drivers of ecosystem processes. ECM fungi vary in their effect on host plants and host-specificity, making them important considerations in restoration projects seeking to restore target tree species. Restoration strategies such as burning and thinning may have strong impacts on ECM fungi, and given the that ECM are important in structuring aboveground communities and maintaining certain dominant plant taxa, knowledge of ECM fungal response is needed to ensure restoration efforts succeed. Using molecular methods, this research …

Differences In Bone Mineral Density Among Adolescent Female Tennis Players And Non-Tennis Players, Kevser Ermin

Electronic Theses and Dissertations

Approximately 10 million Americans have osteoporosis. Physical activity (PA) is an important step in preventing osteoporosis and is one of the major determinants of peak bone mass during adolescence. However, type of pa plays an important role when examining the effects of pa on bone mineral density (BMD). Purpose: 1) to determine the differences in BMD among adolescent female tennis players (TP) and non-tennis players (NTP); 2) to determine the differences in body composition (BC) between adolescent female TP and NTP; 3) to determine whether BC variables (weight, fat mass, and lean mass) were predictive of differences in BMD; and …

The Effects Of Ecological Restoration On Soil Microbial Enzyme Activities And Leaf Litter Decomposition, Anthony Jason Rietl

Electronic Theses and Dissertations

This study examined the immediate effects of ecological restoration on soil enzyme activities and decomposition. The activities of five enzymes: phosphatase, ?-glucosidase, ?-N-acetylglucosadminidase (NAGase), phenol oxidase, and lignin-peroxidase were measured in both soils and on decomposing Quercus falcata leaf litter in unburned, burned, and burned and thinned plots in a mesic forest in northern Mississippi. Rates of decomposition were also assessed for Q. falcata leaf litter at each plot. The restoration treatments decreased phosphatase activity in relation to an increase in soil organic matter after the fire, and increased NAGase activity in relation to a decrease in leaf litter after …

Species Composition And Spatiotemporal Pattern Of The Seed Bank And Vegetation In Native And Degraded Florida Rosemary Scrub, Jennifer J. Navarra

Electronic Theses and Dissertations

The soil seed bank plays a dynamic role in the regeneration of plant communities after natural and anthropogenic disturbance. In this thesis, I addressed how disturbances influence the vegetation and seed bank of Florida rosemary scrub. In Chapter One I evaluated changes in species composition and spatiotemporal pattern of the vegetation and seed bank along a gradient of disturbance. During the summers and winters of 2007-2009 percent ground cover and seed bank species composition were assessed among replicates of three vegetation types subjected to minimal, moderate, and extreme anthropogenic disturbance (native rosemary scrub, degraded scrub, and agriculturally improved pasture, respectively). …

Characterizing The Vertical Structure And Structural Diversity Of Florida Oak Scrub Vegetation Using Discrete-Return Lidar, James J. Angelo

Electronic Theses and Dissertations

Vertical structure, the top-to-bottom arrangement of aboveground vegetation, is an important component of forest and shrubland ecosystems. For many decades, ecologists have used foliage height profiles and other measures of vertical structure to identify discrete stages in post-disturbance succession and to quantify the heterogeneity of vegetation. Such studies have, however, required resource-intensive field surveys and have been limited to relatively small spatial extents (e.g.,

Using Landscape Genetics To Assess Population Connectivity In A Habitat Generalist, Tyler Duncan Hether

Electronic Theses and Dissertations

Understanding the nature of genetic variation in natural populations is an underlying theme of population genetics. In recent years population genetics has benefited from the incorporation of landscape and environmental data into pre-existing models of isolation by distance (IBD) to elucidate features influencing spatial genetic variation. Many of these landscape genetics studies have focused on populations separated by discrete barriers (e.g., mountain ridges) or species with specific habitat requirements (i.e., habitat specialists). One difficulty in using a landscape genetics approach for taxa with less stringent habitat requirements (i.e., generalists) is the lack of obvious barriers to gene flow and preference …

Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data, Juan Manuel Daza Rojas

Electronic Theses and Dissertations

Lineage diversification in the Neotropics is an interesting topic in evolutionary biology and one of the least understood. The complexity of the region precludes generalizations regarding the historical and evolutionary processes responsible for the observed high diversity. Here, I use molecular data to infer evolutionary relationships and test hypotheses of current taxonomy, species boundaries, speciation and biogeographic history in several lineages of Neotropical snakes. I comprehensively sampled a widely distributed Neotropical colubrid snake and Middle American pitvipers and combined my data with published sequences. Within the colubrid genus Leptodeira, mitochondrial and nuclear markers revealed a phylogeograhic structure that disagrees with …

Clonality And Genetic Diversity In Polygonella Myriophylla, A Lake Wales Ridge Endemic Plant, Genevieve Metzger

Electronic Theses and Dissertations

Although capable of sexual reproduction, many plants also rely heavily on clonal reproduction. The formation of multiple, physiologically-independent units with the same genotype has important implications for spatial genetic structure and genetic diversity in these plants. The endangered scrub-dwelling perennial, Polygonella myriophylla is known to reproduce both sexually and clonally but no study to date has been able to investigate the spatial genetic patterns that occur in this species. I use microsatellite markers to investigate questions about clonal structure and genetic diversity in five populations of P. myriophylla and address some of the implications of my findings for conservation of …

Taxonomy Versus Phylogeny Phylogeography Of Marsh Rabbits Without Hopping To Conclusions, Rosanna M. Tursi

Electronic Theses and Dissertations

Subspecific taxonomic designations solely based on morphological characters can often lead to erroneous assumptions about the evolutionary history of populations. This study sought to investigate evolutionary questions and conservation implications associated with morphological subspecific designations of island populations. To this end, I focused my attention on the Lower Keys of Florida, a unique chain of islands with well-known geologic history and rich in endemic, endangered subspecies. I employed genetic analyses to evaluate historical variation and contemporary restriction of gene flow between the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) and its sister mainland taxa. A Bayesian phylogeny using 1063 …

Low Cost Production Of Proinsulin In Tobacco And Lettuce Chloroplasts For Injectable Or Oral Delivery Of Functional Insulin And, Diane Burberry

Electronic Theses and Dissertations

Current treatment for type I diabetes includes delivery of insulin via injection or pump, which is highly invasive and expensive. The production of chloroplast-derived proinsulin should reduce cost and facilitate oral delivery. Therefore, tobacco and lettuce chloroplasts were transformed with the cholera toxin B subunit fused with human proinsulin (A, B, and C peptides) containing three furin cleavage sites (CTB-PFx3). Transplastomic lines were confirmed for site-specific integration of transgene and homoplasmy. Old tobacco leaves accumulated proinsulin up to 47% of total leaf protein (TLP). Old lettuce leaves accumulated proinsulin up to 53% TLP. Accumulation was so stable that up to …

Abiotic Differences Between Green Turtle (Chelonia Mydas) Nests In Natural Beach And Engineered Dunes: Effects On Hatching Success, Martha Balfour

Electronic Theses and Dissertations

Habitat loss is among the biggest threats to conservation worldwide, so habitat restoration plays an increasing role in endangered species management. This is especially true for species with high site fidelity, such as nesting marine turtles. Sand replenishment is commonly used to restore coastal beaches after severe erosion events, and may affect marine turtles and other species that live or reproduce in that habitat. I investigated how abiotic characteristics of sand used in a dune restoration project at Archie Carr National Wildlife Refuge, Florida, affected reproduction of the federally-endangered green turtle (Chelonia mydas). Sand structure and composition can affect egg …

An Assessment Of Sea Turtle Nesting Behavior In Relation To Hurricane- And Restoration-Induced Beach Morphodynamics, Tonya Michele Long

Electronic Theses and Dissertations

Coastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote sensing methods allow for broad evaluation of the shoreline and thus the ability to assess sea turtle nesting habitat at a landscape scale. I collected nesting data …

Geographic Variation In Post-Mating Immune Gene Expression In Drosophila Melanogaster, Cheryl Ann Pinzone

Electronic Theses and Dissertations

An organism's immune response may vary due to pathogen pressure in its environment, as well as due to interactions with other organisms. These factors, along with geographic rules (i.e. Gloger's rule) may influence the geographic distribution of the immune response within populations of a species. Here we use real-time quantitative PCR to measure the immune gene expression in six populations collected along the eastern U.S. of Drosophila melanogaster after mating. Antimicrobial genes did not show significant differences in expression due to location, whereas we did observe differences in anti-fungal and pro-phenoloxidase (anti-macromolecule) related genes. These differences in anti-macromolecule resistance are …

Acetazolamide-Induced Decrease Of Apical Fluid Flow In Choroid Plexus Is Independent Of The Concomitant Changes In Aquaporin-1 Expression, Pouya Alexander Ameli

Electronic Theses and Dissertations

Acetazolamide (AZA), the only drug approved for treatment of hydrocephalus, is effective in only 25-30% of patients while its effect on fluid flow in the choroid plexus (CP) is unknown. The drug reversibly inhibits Aquaporin 4 (AQP4), the most highly expressed „water pore‟ in the brain, and it is postulated that it reduces cerebrospinal fluid (CSF) production by modulating AQP1 (mostly found in the apical membrane of the CP). In this study, we sought to elucidate the effect of AZA on AQP1 and fluid flow in CP. Primary CP culture from p10 Sprague-Dawley rats and TRCSF-B cell line were grown …

Estimating Diet And Food Selectivity Of The Lower Keys Marsh Rabbit Using Stable Isotope Analysis, Matthew James Gordon

Electronic Theses and Dissertations

Understanding the effect of food abundance on feeding behavior can benefit conservation efforts in many ways, such as to determine whether impacted environments need food supplementation, whether different locations of threatened species contain different food abundances, or whether reintroduction sites are missing key components of a species’ diet. I studied the relationship between feeding behavior and food abundance in the Lower Keys marsh rabbit (Sylvilagus palustris hefneri), an endangered subspecies endemic to the lower Florida Keys. Specifically, my study set out to measure the relative abundance of the primary plants within the natural habitat of the Lower Keys marsh rabbit …

The Role Of The Feral Pig (Sus Scrofa) As A Disturbance Agent And Seed Disperser In Central Florida's Natural Lands, Camille Rose Brescacin

Electronic Theses and Dissertations

Feral pigs (Sus scrofa) are considered to be among the world’s worst invasive species due to their successful invasion and ecological and economic impact to native and agricultural plants and animals around the world. Feral pigs are significant disturbance agents that destroy plant communities, change soil characteristics, alter nutrient cycling, and create open sites for colonization of both native and non-native plant species through their foraging behavior called rooting. In contrast to native animal disturbances, rooting is a striking feature in the landscape that varies in space, seasonal timing, frequency (number of times rooted), and intensity (depth of rooting). During …

Reproductive Success Of American Kestrels (Falco Sparverius) Nesting In Boxes Along An Interstate In Northeastern Tennessee., Jennifer Robertson Powers

Electronic Theses and Dissertations

Nest box programs provide supplemental nest sites for American Kestrels, Falco sparverius. When the availability of nest sites is a limiting factor, the addition of nest boxes can increase local breeding populations. These programs also facilitate the collection of data on breeding kestrels.

This study focuses on an American Kestrel (Falco sparverius) nest box trail along Interstate 26 in northeastern Tennessee during the breeding seasons of 1998, 1999, 2000, 2003, 2004, 2006, and 2009. Productivity measures and reproductive success of nesting birds are provided and compared to other programs. The data are analyzed across years and by …

Investigating Nectar Rhythms In Squash (Cucurbita Pepo): Effects On Honey Bee (Apis Mellifera) Foraging Behavior., Samuel David Boyd

Electronic Theses and Dissertations

Experiments were performed to investigate the influence of water availability on the diel patterns of nectar secretion (volume, concentration, sugar production) in male squash flowers as well as to discover what physical component of nectar honey bees use to trigger their time-memory. Squash plants were grown in the greenhouse and in the field under both constant and variable watering regimes. Throughout anthesis, nectar volume and sugar concentration were recorded. In the field, the temporal distribution of arrivals to squash was observed with and without blossoms present. In the greenhouse and in the field, squash flowers exhibit a consistent diel pattern …

Dopamine D2 Receptor Priming Enhances Dopaminergic Response To Amphetamine In The Nucleus Accumbens: Role Of The D1 And D2 Receptors., Kimberly Norris Huggins

Electronic Theses and Dissertations

In past work, we have shown neonatal quinpirole (dopamine D₂/D₃ agonist) treatment produces a significant increase in dopamine D₂ receptor sensitivity, a phenomenon known as D₂ receptor priming. Dopamine D₂ receptor priming is common in psychosis. Male and female rats were administered quinpirole (1mg/kg) or saline from postnatal days 1-11 and raised to adulthood (P60). As adults, rats were administered d-amphetamine sulfate (1mg/kg) or saline every other day for 14 days. Approximately 10 min before each amphetamine or saline injection, animals were administered the D1 antagonist SCH 23390 (0.1 mg/kg), the D2 antagonist eticlopride …

Genetic Structure Of Yonahlossee Salamander Populations., Joshua Andrew Rudd

Electronic Theses and Dissertations

Plethodon yonahlossee is the largest eastern Plethodontid salamander. It has been classified as a species of greatest conservation need by the Tennessee Wildlife Resources Agency (TWRA). Found only in mountainous areas along the borders of Tennessee, North Carolina, and Virginia, populations of the yonahlossee are considered to be rare and local throughout their range. Genetic differentiation among populations of any species is usually attributable to long-standing, extrinsic barriers to gene flow. Because of their disjunct population structure and some observed morphological variation, genetic differentiation among yonahlossee populations is expected. A genetic structure study of yonahlossee was conducted to identify any …

Effects Of Participation In Inquiry Science Workshops And Follow-Up Activities On Middle School Science Teachers' Content Knowledge, Teacher-Held Misconceptions, And Classroom Practices, Linda F. Cepeda

Electronic Theses and Dissertations

An important aspect of developing science literacy for all students is developing science-literate teachers. With the implementation of the No Child Left Behind Act, many middle school teachers found themselves in a position where they were no longer qualified to teach middle school science. This study was designed to help science teachers increase their science content knowledge, identify and resolve misconceptions/errors they may have, and assist them in their teaching by providing strategies for inquiry-based teaching, science laboratory exercises, and science equipment.

Teachers enrolled in biology courses offered by the Rocky Mountain Middle School Math and Science Partnership participated in …

Reversed-Phase Hplc Determination Of Alliin In Diverse Varieties Of Fresh Garlic And Commercial Garlic Products., Aaron Kwaku Apawu

Electronic Theses and Dissertations

Alliin is a predominant flavor precursor in garlic cloves. It interacts with the enzyme alliinase when garlic cloves are crushed, cut, or chewed to produce allicin, an unstable thiosulfinate that is the main biologically active component of fresh crushed garlic. Biological functions and health benefits of garlic include reduction of cancer risk in humans, improving immune system, and anti-microbial, anti-oxidant, and anti-hypertensive activities. The quality of fresh garlic and garlic products is usually related to its alliin content and allicin release potential. This research presents a simple, rapid, and precise HPLC method for alliin determination. It involves the use of …

A Practical Comparison Between Traditional Periodization And Daily-Undulated Weight Training Among Collegiate Track And Field Athletes., Keith Ballard Painter

Electronic Theses and Dissertations

Recently, comparisons of "periodized" strength training methods have become a focus of sport science. Daily undulating periodization (DUP), using daily alterations in repetitions, has been developed and touted as a superior method of training. The purpose of this study is to compare traditional periodization (TRA) to DUP in Division I track and field athletes. Thirty-one athletes were assigned to either a TRA or the DUP group training programs based on sex, year, and event. Training lasted 10 weeks. There were 4 testing sessions focusing on strength characteristics. Although, trends favored the TRA group for strength and rate of force development, …