Life Sciences Commons^™

Phylogenetics, Morpohology, And Genomic Evolution In Physarieae (Brassicaceae), Sara Fuentes-Soriano

Dissertations

The mustard family (Brassicaceae) is economically important but the evolution of its morphology is not well understood. I investigate the evolution of morphological and genomic characters and calculate ancestral trait values in the Brassicaceae within a phylogenetic context using the tribe Physarieae as a model system. Physarieae are a unique and diverse group of American mustards characterized by multi-aperturate pollen. Phylogenetic analyses of DNA sequences (chloroplast ndhF and nuclear ITS and LUMINIDEPENDENS) were used to test the monophyly and explore evolutionary relationships of Physarieae. The phylogenetic inferences were used to identify morphological traits to delimit the tribe, to interpret the …

Development Of A Methodology To Attain High Levels Of Storage Proteins In Cassava Tuberized Roots And Its Implications, Mohammad Abhary

Dissertations

Cassava (Manihot esculenta Crantz.) is a member of the Euphorbiaceae family, cultivated in the tropics and subtropical areas as a staple food crop for more than 700 million people around the world. The starchy storage roots of cassava are rich in calories and deficient in all other nutrients, cassava meals has the lowest of all sources of dietary protein. Severe protein deficiencies and malnutrition problems are common among those who rely on cassava as their daily meal. Although cassava is ranked the fifth most important crop in the world, the research on this crop is very limited. Among the limited …

Avian Developmental Endocrinology: The Effects And Role Of Yolk Hormones, Sibling Dynamics, And Life-History, Corinne Patricia Kozlowski

Dissertations

Inter-specific variation of the endocrine system is an underlying component for variation in avian life-history. Females deposit hormones into the yolks of their eggs, and embryonic exposure affects nestling phenotype. Hormones are also produced endogenously by developing nestlings, further influencing their behavior and physiology. This dissertation examines the role of the endocrine system in development by focusing on several different avian taxa. Yolk hormone concentrations often vary across the laying order and may mediate hatching asynchrony. These patterns were characterized in two species that lay asynchronously hatching clutches: Eastern screech owls (Megascops asio) and cockatiels (Nymphicus hollandicus). The patterns described …

4-H Leaders: Factors That Affect Their Persistence In The 4-H Youth Development Program, Regina Schinker

Dissertations

For over one hundred years, the 4-H youth development program has educated millions of children across the country in a variety of programs; from livestock husbandry to leadership skills. Like all programs that have endured, 4-H has had to adjust its focus as society has changed. One area in the 4-H program that has not changed is the heavy reliance on adult volunteer leaders to deliver the educational programs to 4-H youth. Because of the reliance on volunteer 4-H leaders, 4-H professionals and extension office staff are concerned about issues of retention.

The case study examines two related issues: First, …

Geological And Ichthyological Investigations Into Palaeodrainage Hypothesis For The Tennessee River, Andrea Karen Persons

Dissertations

The course of the ancestral Tennessee River has been debated in both the geological and biological literature for over 100 years. Several of the proposed courses for the ancestral Tennessee place its course across the state of Mississippi. Geochemical analysis of sedimentary rocks in the Pascagoula River basin supports these hypotheses suggesting that the rocks in the Pascagoula basin were derived from the Highland Rim of Tennessee and northern Alabama, while geochemical analysis of rocks from the Pearl River basin point to deposition from a mixture of sources including the ancestral Mississippi River and perhaps the ancestral Tennessee. To delve …

Regulation Of Biofilm And Antibiotic-Resistance By The Modulator Of Sara (Msa) In Staphylococcus Aureus, Antony Schwartz

Dissertations

Staphylococcus aureus is an important human pathogen that is the causative agent of life-threatening diseases such as endocarditis and osteomyelitis. The ability of S. aureus to thrive as a successful pathogen can be partially attributed to its ability to form biofilm. Biofilm is an extracellular polysaccharide, protein, and DNA-based slime layer that protects the bacterial community. The global regulator sarA is essential for biofilm formation. Since the modulator of sarA (msa) gene regulates several virulence factors and is required for the full expression of sarA, the capacity of the msa mutant to form a biofilm was examined. The mutation of …

Toxicogenomics Analysis Of Non-Model Transcriptomes Using Next-Generation Sequencing And Microarray, Arun Rawat

Dissertations

With the advent of next generation technologies like Roche/454 Life Sciences that require low cost and less time for sequencing will help in providing a workable draft of non-model species genomes. Availability of high throughput microarray technologies for gene expression profiling provides low-cost tools for investigation of highly-integrated responses to various stimuli. These advancements along with bioinformatics processing have led to an increasing number of non-model species having well-annotated transcriptomes. The project focuses on the life cycle of development, functional annotation, and utilization of genomic tools for the avian wildlife species to determine the molecular impacts of exposure to munitions …

A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves

Dissertations

This dissertation describes an automated technique for ascertaining the values of the geometric calibration parameters of an airborne lidar. A least squares approach is employed that adjusts the point cloud to a single planar surface which could be either a narrow airport runway or a dynamic sea surface. Going beyond the customary three boresight angles, the proposed adjustment can determine up to eleven calibration parameters to a precision that renders a negligible contribution to the point cloud’s positional uncertainty.

Presently under development is the Coastal Zone Mapping and Imaging Lidar (CZMIL), which, unlike most contemporary systems that use oscillating mirrors …

Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle

Dissertations

The Alabama shad, Alosa alabamae, is an anadromous species that is in decline and has seen extirpations from impoundments as well as decreased water quality. Alabama shad live in the Gulf of Mexico and ascend Northern Gulf of Mexico Drainages to reproduce early in the year (January-May). The juveniles spend the majority of the year in these freshwater systems before emigrating out to the Gulf of Mexico as late as December.

This dissertation focuses on the juvenile life stages that occur within the Northern Gulf of Mexico drainages. Spawning conditions of the river, as well as the habitat and diet, …

Folate Receptor-Targeted Delivery Of Small Interfering Rna To Cancer Cells, Yilin Zhang

Dissertations

The vitamin folic acid (folate, FA) has been extensively explored as a targeting ligand to deliver a variety of diagnostic/prognostic/therapeutic agents into various tumors through the assistance of its receptor – the folate receptor (FR). FR is over-expressed in many types of human cancer and can mediate internalization of FA-conjugates through an endocytic pathway. The discovery of small interfering RNA (siRNA), which is cable of inducing potent gene silencing in a sequence-specific manner, provides an excellent molecular tool to suppress aberrant gene expression in malignancies, and therefore siRNA has the potential to revolutionize cancer therapeutics. Towards the goal of developing …

The Role Of Puf3p And Puf4p In The Regulation Of Mrna Decay In Yeast Saccharomyces Cerevisiae, Florencia Andrea Lopez Leban

Dissertations

Proper regulation of gene expression at a cellular level is required in all organisms for their successful adaptation and survival to physiological or environmental changes. In eukaryotes, a convenient way of regulating gene expression is achieved by post-transcriptionally adjusting the decay rates of different mRNAs. The Puf family of proteins in yeast belong to a widespread group of eukaryotic RNA-binding proteins that regulate the lifespans of target mRNAs by sequence specifically binding to 3' untranslated regions (UTRs) and modulating their decay rates. For example, the yeast Puf3 protein binds the COX17 3' UTR, stimulating its deadenylation and subsequent decay. However, …

Algal Community Structure In Water Bodies Of Mississippi: The Role Of Environmental Factors In Its Spatial And Temporal Dynamics, Nestor Raul Anzola

Dissertations

A meta-analysis was done on studies that included six major taxa groups: Cyanobacteria, Chlorophyta, Chrysophyta (primarily diatoms), Euglenophyta, Pyrrophyta, and Rhodophyta and six aquatic habitats of Mississippi to determine the abundance and richness of the algal community and to identify relevant environmental drivers of algal assemblage composition. Twenty algae data sets on small order streams, large streams and rivers, lakes and reservoirs, fish production ponds, brackish water, and marine water were analyzed. Chlorophyta was dominant in lakes and reservoirs and was the most diverse taxa in the phytoplankton of small order streams and large streams and rivers. Cyanobacteria were the …

Patterns Of Diversity, Zoogeography, And Ecological Gradients In Honduran Freshwater Fishes, Wilfredo Antonio Matamoros

Dissertations

Nineteen major river drainages across Honduras were sampled from 2005-2009 in order to understand Honduran geographical patterns of freshwater fish distribution, to delineate the Honduran freshwater fishes ichthyographical provinces, and to understand patterns of species assemblage at the drainage level. A total of 166 species of freshwater fishes were sampled, a 64% increase over previously published reports. Eight species belong to primary freshwater families, 47 to secondary, and 111 to peripherals. In order to understand the species-drainages relationships, a presence-absence matrix was built for the 19 major drainages and 55 primary and secondary freshwater fishes. Correspondence and cluster analysis clearly …

Information Acquisition And Sociality Among Migratory Birds, Zoltán Németh

Dissertations

Information use is a key feature of adaptive behavior: the better informed an individual, the better it is able to adjust its behavior to meet the demands of a variable world. Therefore, most animals attempt to reduce environmental uncertainty by gathering information when it is available. However, tracking unpredictable ecological factors may carry costs as individuals invest valuable time and energy in the process of information acquisition. Social learning (i.e., use of social information inadvertently produced by other individuals) enables the individual to gain rapid and more complete assessment of its novel environment. This process may be particularly important for …

Individuals Differences In Exploratory Behavior Of Prairie Voles, Microtus Ochrogaster, Danielle N. Lee

Dissertations

Individual differences in behavior are significant because they serve as the substrate for natural selection. Within the Behavioral Syndromes framework, researchers study individual differences in behavior of animals. Behavioral Syndromes are defined as correlations between behaviors in different environmental contexts or testing situations. In this study, I examined the effects of litter size and sex ratio, familial relationships, and age and sex on exploratory behavior of prairie voles, Microtus ochrogaster. Exploratory behavior, defined as spontaneous behavioral responses to unfamiliar stimuli, was examined in three novel situations: an open-field with novel objects, a two-way novel choice apparatus, and a complex maze. …

Conservation And Ecology Of The Yellow-Blotched Sawback (Graptemys Flavmaculata), William Winsyl Selman Ii

Dissertations

The role of species conservation is becoming increasingly important due to the mounting pressures from humans on habitats and populations of organisms. This is particularly evident in riverine ecosystems throughout the world where the human demand for freshwater resources is increasing, and consequently, the number of imperiled aquatic organisms is also growing. The seven chapters of this dissertation primarily focus on the Yellow-blotched Sawback, Graptemys flavimaculata, an endangered riverine turtle that is endemic to the Pascagoula River system of southeast Mississippi, USA. At the population level, we aimed to study the impacts of Hurricane Katrina on two study populations within …

Relationships Between Particle Properties And Scattering In Coastal Waters Of The Northern Gulf Of Mexico Influenced By The Mississippi River, Bruce Alan Spiering

Dissertations

This study was conducted to determine how the characteristics of an assemblage of suspended particles, including their composition and size affect the relationship between the optical scattering coefficient b (m-1), and the dry mass of the particles in suspension. Knowledge of the scattering to total suspended matter (TSM) ratio, i.e. the mass specific scattering coefficient b* (m2/g), is important because the light detected by optical imaging sensors used for remote sensing is the light that has been scattered by particles back through the water surface. If this ratio is not known or varies within the region of interest, accurate estimates …

Determining The Relationship Of Human Enteric Viruses In Clinical, Wastewater, And Environmental Samples Utilizing Molecular And Cell Culture Techniques, Jacquelina Susann Williams Woods

Dissertations

This study was the first to examine five significant enteric viruses in human fecal material, sewage, and oysters to show a genetic relationship between human enteric viruses and different sample matrices. Fecal samples were collected from an area hospital and examined for norovirus genotype I (NoV GI), norovirus genotype II (NoV Gil), hepatitis A virus (HA V), adenovirus (ADV), and enteroviruses. During this study, sewage samples were collected from a Waster Water Treatment Plant (WWTP) in Mobile, ALand oyster sentinels were placed at 0.1 nautical miles (nm) (station 1 ), 0.2nm (station 2}, 1.5nm (station 3), and 4nm (station 4) …

Development Of Representative Species-Level Molecular Markers And Morphological Character Analysis Of Leucothoid Amphipods (Crustacea: Amphipoda), Kristine Nicolle White

Dissertations

Leucothoid amphipods were investigated using morphology and molecular rDNA gene sequence fragments. The morphological diagnostic characters for traditional taxonomy have been clarified, a molecular marker for representative species has been developed, and one of the current anamorph-leucomorph connections has been confirmed with molecular sequence data. Ultimately this study has combined traditional morphological and modern molecular methods to clarify the taxonomy and to propose a preliminary phylogeny of the Leucothoidae. Analysis of 18S rDNA gene fragments from 13 species in two genera supported the current morphological species designations and the separation of the family into two clades. Combined analysis of 18S …

Systematic Revision Of The Kalliapseudidae (Crustacea: Peracarida: Tanaidacea) And The Population Genetic Structure And Phylogeography Of A Species Along The Southeastern And Gulf Coasts Of North America, David Thomas Drumm

Dissertations

The Kalliapseudidae is a family of shallow burrow-dwelling marine and estuarine tanaidaceans. There are currently 39 known species of 12 genera and three subfamilies. They are primarily circumtropical in distribution; however, several species are found in temperate waters. The phylogeny of Kalliapseudidae is assessed to test the monophyly of currently accepted subfamilies and genera, based largely on examination of material loaned from various museums and institutions. Multiple exemplars from other apseudomorph families were also included in the ingroup to test the monophyly of the family. Parsimony analyses included 41 terminal taxa and 64 binary and multistate morphological characters. Analyses based …

Soccer Penalty Kick Pre-Impact Cues Of Male Right-Footed High School Soccer Players, Jason Ryan Jones

Dissertations

The purpose of this study was to use direct observation methods to collect evidence of pre-impact cues in a soccer penalty kick and to analyze their predictive powers in determining shot direction. The five pre-impact cues were position of the approachru n, alignmento f the hips,leano ftrunk, placemenot f non-kickingf oot, and actiono f the non-kickings idea rm.V ideo wasc ollecteda ndt hena nalyzedu singa Dartfishrn tagging panel. There were a total of fifty male high school right-footed participants.C oachesfr om areah igh schools occert eamsp rovidedt heir top penaltyk ick takerst o participatein the study.V ideo wasc ollectedo n …

The Natural Provenance: Ecoliteracy In Higher Education In Mississippi, Sarah Elizabeth Wheeless

Dissertations

Researchers have suggested that there is an increasing apathy in the study of natural history both in academic settings and in the scientific community (Schmidly, 2005). Natural history is the cornerstone of ecological literacy. However, most studies of environmental knowledge do not directly address knowledge of local natural history. Instead, they concern knowledge of human environmental issues, environmental concepts, or broad ecological knowledge. Ecoliteracy established the study of natural history as fundamental to environmental knowledge and seeks to determine levels of knowledge of local environments and factors associated with that knowledge (Pilgrim et al., 2007).

This study investigated ecoliteracy in …

High-Throughput Screening Studies Of Inhibition Of Human Carbonic Anhydrase Ii And Bacterial Flagella Antimicrobial Activity, Albert A. Barrese Iii

Dissertations

Complete abstract attached as supplemental file.

The Tumor Suppressor Pkcδ Is Critical For Uv-Induced G2/M Checkpoint Activation And Apoptosis, Edward Lewis Lagory

Dissertations

Protein kinase C delta (PKCδ) is an essential component of the intrinsic apoptotic program. Following DNA damage, such as exposure to UV radiation, PKCδ is cleaved in a caspase-dependent manner, generating a constitutively active catalytic fragment (PKCδ-cat) which is necessary and sufficient for keratinocyte (KC) apoptosis. We found that in addition to inducing apoptosis, expression of PKCδ-cat caused a pronounced G2/M cell cycle arrest in both primary human KCs and immortalized HaCaT cells. Consistent with a G2/M arrest, PKCδ-cat induced phosphorylation of Cdk1 (Tyr15), a critical event in the G2/M checkpoint. Treatment with the ATM/ATR inhibitor caffeine was unable to …

Gabab Regulation Of Methamphetamine-Induced Associative Learning, Robin Michelle Voigt

Dissertations

Addiction is a chronic, relapsing disorder for which strikingly few effective therapies exist, and there are no FDA-approved pharmacotherapies for methamphetamine (Meth) addition. There is an immense need to identify the neurobiological underpinnings of psychostimulant addiction and develop efficacious drug therapies to compliment the current mainstay treatment of behavioral/cognitive therapy.

Re-exposure to cues associated with psychostimulants (e.g., drug paraphernalia) increase neuronal activity and can elicit drug-craving and -seeking; an effect which is profound and long-lasting. A mechanism to disrupt those brain processes which are necessary to maintain the association may reduce the incidence of cue-elicited relapse.

Conditioned place preference (CPP) …

Deconstructing Ihf-Mediated Inhibition Of The Complex Acs Promoter, David S. Thach

Dissertations

acs encodes a high affinity enzyme that permits survival during carbon starvation. As befits a survival gene, its transcription is subject to complex regulation. Previously, the Wolfe lab reported that CRP activates acs transcription by binding tandem DNA sites located upstream of the major acsP2 promoter and that the nucleoid protein IHF binds three specific sites located just upstream. The most proximal site (IHF III) exhibits reduced transcription compared to the full-length promoter or to a construct lacking all three IHF sites. The goal of my research was to understand how IHF III inhibits CRP-dependent acs transcription. First, I helped …

Developmental Characterization Of Cara Mitad: A Drosophila Nuclear Receptor Co-Regulator, Chhavi Chauhan

Dissertations

In insects and vertebrates, hormone titers drive cellular proliferation and differentiation events that guide proper development. Nuclear receptors (NR) respond to these hormone signals by activating cascades of gene expression, along with coregulator protein complexes. In Drosophila melanogaster, fluctuating titers of the steroid hormone ecdysone are responsible for coordinating the timing of organismal development. Despite major advances in our understanding of Drosophila NR activities, we lack essential knowledge of the coregulators that are required for their proper function.

We have recently identified the Drosophila cara mitad (cmi) (`dear half') gene. The deduced CMI protein is closely related to the N-terminal …

Polyomavirus Enhancer Activator 3 (Pea3), A Member Of The Ets Family Of Transcription Factors, Is A Transcriptional Activator Of Notch-1 And Notch-4 In Breast Cancer: An Opportunity For Novel Combinational Therapy, Anthony George Clementz

Dissertations

Women diagnosed with triple-negative breast cancer have the worst overall prognosis and frequently present with metastatic tumors. To date, there are no targeted therapies available to combat this aggressive form of breast cancer due to the lack of expression of well-known targets such as ER-alpha, PR, or HER2/neu. Therefore, there is an immediate need to identify novel targets that are responsible for the proliferation, survival, and invasive phenotype. Notch-1 and Notch-4, both potent breast oncogenes, are overexpressed in triple-negative breast cancers-associated with the poorest overall survival. PEA3 (polyomavirus enhancer activator 3), a member of the Ets family of transcription factors, …

The Role Of Igf-1 And Notch Signaling In Thoracic Malignancies., Sandra Eliasz

Dissertations

Thoracic malignancies are one of the deadliest of all cancers, being the leading cause of cancer death in the Western world. Thoracic malignancies arise from different tissues; however the most common are of epithelial (commonly referred to as non-small cell lung cancer, or NSCLC), neuroendocrine (small cell lung cancer, or SCLC) and mesothelial origin (malignant mesothelioma, or MM). The DNA oncogenic virus Simian Virus 40 (SV40) has been shown to cooperate with environmental oncogenic fibers in the onset of MM. Insulin like growth factor-1 (IGF-1) signaling plays a central role in all thoracic malignancies and in the process of SV40-mediated …

Notch Signaling Is Important In The Survival, Proliferation, And Self-Renewal Of The Putative Breast Cancer Stem Cell Population, Peter Grudzien

Dissertations

Numerous studies have identified stem-like cells, termed cancer stem cells (CSCs), in breast tumors and established cell lines. It has been hypothesized that CSCs are responsible for breast cancer formation, progression and recurrence; therefore, a deeper understanding of the signaling pathways regulating CSC survival will benefit development of novel therapeutic strategies. Notch signaling, which is dysregulated in breast cancer and has been implicated in mammary stem cell self-renewal, and can be effectively blocked by gamma-secretase inhibitors (GSIs). While GSIs are currently in clinical trials for breast cancer, it is not fully understood how these compounds will affect CSCs or if …