Digital Commons Network^™

The Effects Of Intracerebroventricular Leptin On Milk Availability In Lactating Rats, Brittany Lynita Moore

Electronic Theses and Dissertations

Reports have linked energy balance along with adipocyte derived leptin action to improved fertility. Recent evidence indicates that leptin hormone is present in breast milk and leptin receptors are well expressed in mammary epithelial cells. The hypothesis that insufficiency of leptin restraint in the hypothalamus may underlie infertility in rodents and the failure of lactating breast to express adequate amount of milk was tested. Female Sprague-Dawley rats were injected leptin through intracerebroventricular cannulation (ICVC) of the third ventricle. Female rats were mated with stud males and observed throughout gestation. Compared to the control groups, leptin treatment increased prolactin levels in …

Characterization Of Fhua 104/149c: A Double Cysteine Fhua Mutant With Normal Binding And Diminished Transport, Ada K. Hagan

Electronic Theses and Dissertations

Iron is an essential element for most bacteria and is commonly acquired by siderophores, molecules secreted under iron restricted environment to bind ferric iron. Gram negative cells actively uptake these complexes via outer membrane-transport proteins such as FhuA in Escherichia coli. Structural analysis of receptors revealed a conserved β-barrel occluded by an N-terminal plug domain. The cell membrane TonB/ExbB/ExbD complex presumably supplies energy via interaction between the FhuA N-terminal TonB box and the C-terminal domain of TonB. In order to better understand the mechanism of action the FhuA mutant 104/149C, tethering the central β-strands 4 and 6 of the …

Biogenic Amine Levels Correlate With Time Of Day, Age, Light Cycle, And Aggressive State In The Flesh Fly, Sarcophaga Crassipalpis, Veronica L. Fregoso

Electronic Theses and Dissertations

The biogenic amines serotonin (5HT), dopamine (DA), and octopamine (OA) have been indicated in the regulation of behaviors, including aggression. The flesh fly, Sarcophaga crassipalpis, was used to investigate ontogenetic and circadian changes in amines and aggression. Heads of male flies were analyzed for amine content using high performance liquid chromatography with electrochemical detection (HPLC-ECD) at 3 time points on each of 4 consecutive days in 2 light cycles, 12:12 LD and 15:9 LD. Both DA and OA levels decreased with age. Light-cycle dependent differences were observed for all amines in overall levels and patterns of change throughout the …

Net Impulse And Net Impulse Characteristics In Vertical Jumping, Satoshi Mizuguchi

Electronic Theses and Dissertations

The purpose of this dissertation was to explore the potential use of net impulse and its characteristics in vertical jumping to monitor athletes' performance status and responses/adaptations to interventions. Five variables were proposed as net impulse characteristics: net impulse height and width, rate of force development, shape factor, and net impulse proportion. The following were then examined: 1) test-retest reliability of a new approach to identify net impulse in a force-time curve and of net impulse characteristics and criterion validity of the new approach; 2) effective measures of net impulse characteristics; 3) relationships between training-induced changes in its characteristics and …

Application Of Multivariate Statistical Methodology To Model Factors Influencing Fate And Transport Of Fecal Pollution In Surface Waters, Kimberlee K. Hall

Electronic Theses and Dissertations

Degraded surface water quality is a growing public health concern. While indicator organisms are frequently used as a surrogate measure of pathogen contamination, poor correlation is often observed between indicators and pathogens. Because of adverse health effects associated with poor water quality, an assessment of the factors influencing the fate and transport of fecal pollution is necessary to identify sources and effectively design and implement Best Management Practices (BMPs) to protect and restore surface water quality. Sinking Creek is listed on the State of Tennessee’s 303D list as impaired due to pathogen contamination. The need to address the listing of …

An Investigation Of Bacterial Ribonucleases As An Antibiotic Target, Ashley Denise Frazier

Electronic Theses and Dissertations

Antibiotics have been commonly used in medical practice for over 40 years. However, the misuse and overuse of current antibiotics is thought to be the primary cause for the increase in antibiotic resistance.

Many current antibiotics target the bacterial ribosome. Antibiotics such as aminoglycosides and macrolides specifically target the 30S or 50S subunits to inhibit bacterial growth. During the assembly of the bacterial ribosome, ribosomal RNA of the 30S and 50S ribosomal subunits is processed by bacterial ribonucleases (RNases). RNases are also involved in the degradation and turnover of this RNA during times of stress, such as the presence of …

Phylogeny Of Panthera, Including P. Atrox, Based On Cranialmandibular Characters, Leigha M. King

Electronic Theses and Dissertations

Over the past 20 years both morphological and molecular phylogenies have been proposed for extant and extinct members of the family Felidae. However, there remain several discrepancies, particularly within the genus Panthera and the position of Panthera atrox. Consequently, morphologic characters from the skull and dentary were analyzed within Panthera (including all extant and one extinct taxa) to gain a better understanding of pantherine phylogeny. Multiple specimens of each taxon were analyzed, including: P. leo, P. tigris, P. onca, P. pardus , Uncia uncia, and Neofelis nebulosa. Four outgroups were used; Crocuta crocuta, Metailurus ssp., Proailurus lemanensis …

Cloning, Expression, And Biochemical Characterization Of Recombinant Putative Glucosyltransferases Clone 3 And 8 From Grapefruit (Citrus Paradisi), Deborah Hayford

Electronic Theses and Dissertations

The grapefruit plant, Citrus paradisi, tends to accumulate high levels of flavonoid glycosides such as flavanones and flavones. Flavonoids have a vast array of important functions in plants and also in humans. Glucosyltransferases (GTs) are enzymes responsible for glucosylation reactions. In our pursuit to study the structure and function of flavonoid GTs, we have used molecular approaches to identify, clone, express, and functionally characterize the enzymes. This research was designed to test the hypothesis that PGT3 is a flavonoid glucosyltransferase and is subject to biochemical regulation. PGT3 has been tested for GT activity with compounds representing subclasses of flavonoids …

Cloning, Heterologous Expression In Yeast, And Biochemical Characterization Of Recombinant Putative Glucosyltransferase Clones 9 And 11 From Grapefruit (Citrus Paradisi), Anye Wamucho

Electronic Theses and Dissertations

Flavonoids are plant secondary metabolites that play diverse roles in plants and human health. These compounds in most part exist in the glucosylated form. Grapefruit accumulates high levels of glucosylated flavonoids. Plant secondary product glucosyltransferases (GTs) catalyze the glucosylation reaction, but due to low homology at both the nucleotide and amino acid sequence level of different GTs, it is not possible to ascribe function based on sequence only. The hypotheses that PGT clones 9 and 11 are plant secondary product GTs and are biochemically regulated were tested. PGT 9 has been cloned into Pichia pastoris using the pPICZA and pPICZAα …