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The Evolution Of Prezygotic Reproductive Isolation In The Drosophila Pseudoobscura Subgroup, Sheri Dixon Schully

LSU Doctoral Dissertations

Newly forming species that have differentiated in allopatry may evolve numerous barriers that prevent the interbreeding when they come back into contact with each other. The objective of this dissertation is to evaluate some mechanisms of prezygotic reproductive isolation in the D. pseudoobscura subgroup. I begin by evaluating how the evolution of female preferences and male sexual characters lead to reinforcement between Drosophila pseudoobscura and its congener D. persimils. In particular, I will evaluate two alternative hypotheses; Preference Evolution and Discrimination Enhancement, to determine how selection reduces hybridization between these sister species. Both hypotheses predict a reduction in the overlap …

Dna Supercoiling With A Twist, Edwin Kamau

LSU Doctoral Dissertations

The level of torsion in double-stranded DNA regulates base-pair stability and DNA conformation. It is important in initiation and regulation of specific DNA metabolic processes as well as chromatin assembly. High mobility group proteins (HMGB) are architectural proteins whose HMG DNA binding domains confer significant preference for distorted DNA, such as supercoiled DNA and 4-way junctions. HMGB proteins play a role in transiently regulating or conserving DNA torsion. Topoisomerases regulate DNA supercoiling, which has been argued to provide a coherent explanation for the main modes of transcriptional control - stringent control, growth-rate control and growth-phase control during the normal cell …

Evaluation Of The Spatial Removal Of Nitrogen In The Marshland Upwelling System, Andrea Reneé Turriciano

LSU Master's Theses

The Marshland Upwelling System (MUS) is an alternative onsite wastewater treatment technology designed to utilize the natural ecology of saltwater marshes to remove human-borne contaminants. Over the past twelve years, MUSs have been installed in Port Fourchon, Louisiana, Moss Point, Mississippi, and Bayou Segnette, Louisiana. The purpose of this study was to investigate the nitrogen reduction capabilities of the Bayou Segnette system. The objectives of this research were to: 1) determine the first-order removal constants necessary for the development of nitrogen transport equations, 2) explore the spatial dependencies of nitrogen concentrations within the Bayou Segnette system, and 3) determine the …

Sites Of Resistance: Language, Intertextuality, And Subjectivity In The Poetry Of Diane Wakoski, Cordelia Maxwell Hanemann

LSU Doctoral Dissertations

This dissertation explores the interconnectedness of language and related cultural texts and women’s subjectivity. The poststructuralist feminist enterprise of examining and critiquing language and signifying practices for the ways in which they impose social values and of interrogating and undermining the fixity of meanings in cultural texts will serve as my primary frame. Concerned with the individual (gendered) consciousness, poststructuralist feminist theory of subject formation posits that while language, along with ideologically biased texts of the culture, construct subjects, language and the cultural texts also serve as sites of resistance for the deconstruction and reconception of individual and collective subjectivities. …

Regulatory Intricacies That Confer Temporal Control Of Conjugation And Antibiotic Production Functions In Streptomyces: New Variations On Old Themes, Kevin Lee Schully

LSU Doctoral Dissertations

The complex life style of streptomycetes requires that the appropriate program of genes be expressed at the appropriate times. For example, conjugation occurs solely within the substrate mycelium stage of development while antibiotic production occurs in the aerial mycelium. Thus, complex regulatory mechanisms involving numerous modes of control have evolved that confer temporal regulation of functions governing these expression programs. Conjugation of the Streptomyces lividans plasmid pIJ101 utilizes only seven plasmid functions in its transmission. Two of these, tra and clt, are essential while three additional functions, spdA, spdB and kilB augment the process, with KorA and KorB regulating the …

Alu Retrotransposition-Mediated Genomic Variation Within The Primate Order, Pauline Ann Callinan

LSU Doctoral Dissertations

Retrotransposons are an active family of mobile elements within primate genomes and the Short INterspersed Element (SINE) Alu is the most abundant member. These non-autonomous elements are responsible for introducing genomic diversity on an intra- and inter- species level that is useful in studies of forensic identity, population genetics, and evolutionary biology. In a computational survey of the human sex chromosomes, 344 recently integrated Alu elements were detected and subjected to empirical testing by polymerase chain reaction to determine presence/absence polymorphism. Sixteen elements were found to be polymorphic on the X chromosome, and only one polymorphic element on the Y …

Characteristics Of Reduced Fat Milks As Influenced By The Incorporation Of Folic Acid, Kamalesh Achanta

LSU Master's Theses

Folic acid plays an important role in the prevention of neural tube defects such as spina bifida and anencephaly, heart defects, facial clefts, urinary abnormalities and limb deficiencies. Milk and milk products serve as a potential source for folic acid fortification due to the presence of folate binding proteins which seem to be involved in the folate bioavailability. Though milk is a not a good source of folic acid, fortification could help in the prevention of the above mentioned defects. The objective of this study was to examine the physico-chemical characteristics of reduced fat milks fortified with folic acid. Reduced …

Yellow Fever In The Felicianas: The Epidemic Of 1878 And Its Effects Upon The Residents Of These Rural Parishes, Mary Jane Duke Russell

LSU Master's Theses

This research documents the spread of yellow fever across the rural Louisiana parishes of East Feliciana and West Feliciana in 1878 and examines the reactions and responses of the residents to medical, social and economic stresses produced by that epidemic. Descriptive details highlight the variability of individual ideas and mindsets at play against the backdrop of accepted paradigms, belief systems and current technology. In 1878 the Aëdes aegypti mosquito had not yet been identified as the vector of the arbovirus (arthropod borne virus) that causes yellow fever. A short history of yellow fever in the United States and a discussion …

Development And Characterization Of Antimicrobial Edible Films From Crawfish Chitosan, Kandasamy Nadarajah

LSU Doctoral Dissertations

Inherent antibacterial/antifungal properties and film-forming ability of chitosan make it ideal for use as a biodegradable antimicrobial packaging material. This study was attempted to develop antimicrobial films from crawfish chitosan. Traditional chitosan production involves: deproteinization (DP), demineralization (DM), decolorization (DC), and deacetylation (DA). Modification of chitosan production affects film properties. Effects of chitosan production protocols, film-casting solvents, and plasticizer contents on physicochemical, mechanical and antibacterial properties were investigated. Four chitosans were prepared from traditional (DPMCA) and modified processes [excluding either DP, DC or both DP and DC]. Chitosan (1%w/v) was dissolved in 1% acetic, ascorbic, citric, formic, lactic and/or malic …

Belowground Productivity Of Mangrove Forests In Southwest Florida, Beatriz Eugenia Giraldo Sánchez

LSU Doctoral Dissertations

Studies in belowground dynamics are limited mainly due to the difficulty of studying roots despite wide recognition of its importance. This dissertation focused on methods for analyzing mangrove roots, root responses to phosphorus and flooding, and variation in root production between forest types. Techniques to separate live and dead roots such as colorimetric, fluorescence, buoyancy, and visual assessment were compared. The traditional method of visual assessment combined with root buoyancy was accurate, fast, and applicable to larger samples. Additionally, techniques such as rhizotrons, root ingrowth cores, and root image analysis were useful to study mangrove roots. Root and litter production, …

Modulation Of Adipocyte Genes By Signal Transducers And Activators Of Transcription, Jessica C. Hogan

LSU Doctoral Dissertations

Members of the STAT transcription factor family are expressed in adipocytes, including STATs 1, 3, 5A, 5B, and 6. Although STATs 1 and 5 proteins are known to be induced during adipogenesis, the functions of these STATs in mature adipocytes are not known. Hence we have sought to identify adipocyte genes which are transcriptionally regulated by STATs to elucidate a role of these proteins in fat cells. We have characterized STAT binding sites in the promoters of four adipocyte genes, PPARγ2, LPL, FAS and C/EBPδ. PPARγ2 expression decreases in adipocytes following exposure to IFNγ, an activator of STAT1. IFNγ induces …

Arthur Koestler's Hope In The Unseen: Twentieth-Century Efforts To Retrieve The Spirit Of Liberalism, Kirk Michael Steen

LSU Doctoral Dissertations

The analysis in this dissertation connects Arthur Koestler’s nonfiction and fiction to the political circumstances that defined Europe during the early twentieth century. It draws particular attention to events in the 1930s as representing a paucity of choices that frustrated certain liberal values held by Koestler and others. It shows how after taking sides with the German Communist Party in the early 1930s, he confronted then rejected the politics of the extreme left and right, leading himself toward a dual career as social philosopher and anti-Communist. This paper will explain how Koestler’s reporting of the Spanish Civil War, combined with …

Plasmid-Mediated High-Level Gentamicin Resistance In Bacteria For The Turtle Farm Environment In Louisiana, Maria Alejandra Diaz

LSU Doctoral Dissertations

The sale of small turtles is banned from the US market due to concerns about their excretion of Salmonella spp. To produce a safe pet for the export market, the Louisiana pet turtle industry uses 1000 μg/ml gentamicin sulfate baths to eradicate Salmonella spp. from turtle eggs. In 1999, we analyzed bacterial samples recovered from turtle farms and found that strains of Salmonella enterica subsp. arizonae and other bacteria such as Salmonella enterica subsp. enterica, Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, were resistant to high concentrations of gentamicin (>2000 μg/ml) and to other aminoglycosides. The goal …

Associations Among Mothers' Reports Of Family Daily Hassles And Family Resources And Children's Cognitive Ability: An Exploratory Study, Troy D. Stuart

LSU Doctoral Dissertations

The purpose of this study was to examine the relationships among daily hassles, family resources, and children’s cognitive ability. Particular emphasis was placed on examining the relationships among the variables by family structure. A total of 205 children in first-grade and third-grade and their mothers participated in the study. There were 120 children from intact families and 85 children from single mother families in the study. All mothers completed assessments on family level variables and all children completed the BIA test of cognitive ability. Multiple regression analyses were utilized to examine the relationships among the variables. Daily hassles and cohesion …

Common Sense Philosophy And Politics In America: John Witherspoon, James Mccosh, And William James, Scott Philip Segrest

LSU Doctoral Dissertations

This dissertation examines the political significance of the two leading strains of common sense thought in the history of American philosophy—Scottish Common Sense and Pragmatism—as suggested in the writings of John Witherspoon and James McCosh in the Scottish Common Sense line, and of the more famous co-founder of Pragmatism, William James. These two strains of American common sense are placed in context of the larger Western common sense tradition. Each is shown to aim at finding a solid middle ground epistemologically between skeptical doubt and idealistic certitude that could serve as a stable basis for moral and political life. Witherspoon, …

Nutrient Interactions, Plant Productivity, Soil Accretion, And Policy Implications Of Wetland Enhancements In Coastal Louisiana, Christopher Brantley

LSU Doctoral Dissertations

Ecosystem response, stakeholder interactions, and the policy implications to a wetland assimilation project are reported here for the City of Mandeville, St. Tammany Parish, Louisiana. Between September 1998 and October 2004, input of secondarily treated wastewater effluent was found to have a net positive effect on the downstream wetland receiving basin. The major hydrologic inputs to the system are the effluent, precipitation, and back water flooding from Lake Pontchartrain. Nutrient levels were generally low except in the immediate vicinity of the outfall and removal efficiencies of N and P ranged from 44% to 87% and 25% to 93%, respectively. On …

Uric Acid-Mediated Modulation Of The Transcriptional Regulator Hucr From Deinococcus Radiodurans, Steven P. Wilkinson

LSU Doctoral Dissertations

The MarR family of transcriptional regulators comprises a subset of winged helix DNA-binding proteins and includes numerous members that function in environmental surveillance of aromatic compounds. This study presents a biochemical characterization of a novel MarR homolog, HucR (hypothetical uricase regulator), from the DNA damage-resistant eubacterium, Deinococcus radiodurans. Circular dichroism spectroscopy suggests that HucR has ~47% alpha-helix and 10% beta-strand conformation at 25 deg C, and undergoes a transition to a disordered state with Tm = 51.1 ± 0.0 deg C. HucR binds as a homodimer with high sequence-specificity to a single site in its promoter region (hucO) with an …

Molluscan Taphonomy As A Proxy For Recognizing Fossil Seagrass Beds, Jill Suzanne Leonard-Pingel

LSU Master's Theses

Seagrass beds, important marine ecosystems both economically and environmentally, have a poor fossil record. As a result, little is known about the geographic distribution of seagrasses over historic and geologic time, or their abundance when unaltered by anthropogenic effects. The purpose of this study is to define a taphonomic signature unique to seagrass beds that can be used as a proxy for identifying the seagrass habitat in the fossil record. In order to develop this proxy, sediment samples from Recent seagrass and non-seagrass environments were collected, and the molluscan bioclasts from these samples were categorically ranked for the following taphonomic …

Civic Orientation Predictors Of Black Students: An Exploratory Study, Joe Lee Lott Jr

LSU Doctoral Dissertations

Institutions are becoming more cognizant of preparing students for global leadership through measures such as service-learning and community service. Colby and her colleagues (2003) suggest that institutions should guide students to believe that they are members of a shared social structure. Black students are a group whose civic participation has sharply declined between the 1970s and 1990s (Putnam, 2000) when 50 years ago they were one of the most active civic groups (Davis, 1993). This exploratory study investigated the relationships between Black students’ citizenship perspectives and independent variables such as institution type, racial identity, gender, classification, major, age, and socioeconomic …

A Proteomic Approach To Indentifying Defense Related Proteins In Rice Challenged With The Fungal Pathogen Rhizoctonia Solani, Joohyun Lee

LSU Doctoral Dissertations

Sheath blight caused by the fungal pathogen fungus Rhizoctonia solani Kuhn, is an economically important disease of rice in the southern United States. The overall goal of this study was to identify proteins that were affected by sheath blight development by comparing protein expression patterns between the susceptible, wild-type cultivar Labelle and the resistant, mutant line LSBR-5. Protein samples were extracted from inoculated and non-inoculated rice leaf sheaths after 24 hrs and then loaded onto a Bio-Rad 2-DE gel system. Approximately 1,000 protein spots stained with Sypro-Ruby were reproducibly resolved in all gels used in the comparison analysis. The comparison …

A Comprehensive Analysis Of Human Pre-Ta Line-1 And Ya-Lineage Alu Mobile Elements, Anthony Canaan Otieno

LSU Doctoral Dissertations

Long INterspersed Elements (LINEs or L1)and Short INterspersed Elements (SINEs) have played a critical role in shaping the human genomic landscape, making up about 33% of the human genomic mass. In this work, preTa, an L1 subfamily and the Ya-lineage of Alu SINEs were examined to determine their impact on the human genomic architecture and diversity. We analyzed 362 preTa L1 elements and 2318 Ya lineage Alu elements using computational methods and polymerase chain reaction (PCR) assays. PCR analysis on a geographically distinct panel of human populations indicated that 33 (14%) of preTa L1 elements and 313 (22%) of Ya-lineage …

Development, Evaluation And Characterization Of Protein-Isoflavone Enriched Soymilk, Janette Ethel-Pessi Saidu

LSU Doctoral Dissertations

Adequate provision of soy isoflavone and protein in soybean products is essential in meeting the soy health claim and the promotion of a healthy product. Commercial soymilks contain inadequate amounts of protein and isoflavone to meet the FDA recommended 25g and 40-50mg/day level, respectively, in 1-2 servings. This research study set out to investigate the possibility of producing a protein-isoflavone enriched (PIE) soymilk by incorporating soy germ in soymilk to provide the recommended FDA level in 1-2 servings. Three PIE soymilks containing 25 (SG25), 30 (SG30), and 35% (SG35) germ were prepared and compared to 100% whole soybean milk (WSB-control) …

Long-Term Freshwater Input And Sediment Load From Three Tributaries To Lake Pontchartrain, Louisiana, Kangsheng Wu

LSU Doctoral Dissertations

Lake Pontchartrain and the drainage basin have experienced environmental degradation because of human settlement, land use and climate changes. A thorough understanding of hydrologic trends and variability associated with the changes is critical for sustainable water resources management and ecosystem restoration in the region. This study examined freshwater inflow (1940-2002) and suspended solids loadings (1978-2001) from three upper Lake Pontchartrain watersheds that contribute to the lake estuary: the Amite, Tickfaw, and Tangipahoa river watersheds. The relationships of freshwater inflow and suspended solids loadings with climate variables and population growth were investigated. Using observed daily discharge, a spatially-distributed hydrologic model (SWAT) …

Synthesis, Characterization And Application Of Polymeric Surfactants In Micellar Electrokinetic Chromatography: Use Of Ionic Liquids As Modifiers, Simon M. Mwongela

LSU Doctoral Dissertations

The goal of the research presented in this dissertation is to synthesize, characterize, and apply a novel chiral amino acid-based surfactant and achiral sulfate-based surfactants for the effective separations of chiral and achiral compounds in micellar electrokinetic chromatography (MEKC). The first part of this research involves novel synthesis, characterization, and application of polysodium oleyl-L-leucyl-valinate (poly-L-SOLV) for the separation of chiral compounds in MEKC. Surface tensiometry, proton nuclear magnetic resonance, infrared spectroscopy, densitometry and analytical ultracentrifugation were used as the characterization techniques. Optimal MEKC separating conditions were established by varying surfactant concentration, buffer concentration and pH, applied voltage, and capillary temperature. …

V-Atpase Expression And Function In The Brine Shrimp, Artemia Franciscana: Role Of Proton Gradients In Anoxia-Induced Quiescence, Joseph Antonio Covi

LSU Doctoral Dissertations

Upon exposure to anoxia, encysted embryos of the brine shrimp, Artemia franciscana, enter a severely depressed metabolic state, the transition into which is facilitated in part by one of the largest intracellular acidifications ever reported for a eukaryotic organism. However, the endogenous origin of this pH shift remains largely unexplained. We hypothesize that the unexplained acidification is produced by a net flux of protons into the cytoplasm from compartments acidified by a V-type proton pump (V-ATPase) during aerobic development. Northern blots demonstrate expression of the V-ATPase subunit-B mRNA during early development, while Western blots demonstrate the expression of at …

Trends In Extreme Daily Temperature Events In The South-Central United States, Gregory S. Bohr

LSU Doctoral Dissertations

Extreme daily temperatures are meteorological events that can have significant impacts on human and natural systems. As natural and anthropogenic climate changes occur, the frequency of extreme events is likely to change. Because extremes do not change linearly with mean temperatures, it is important to directly examine the record of extremes. This dissertation analyzes the temporal pattern of daily extremes over 1948-2001 in the south-central United States, and identifies significant changes in frequency and persistence, as well as relationships between extreme events and atmospheric circulation.

A global warming of approximately 0.6 Centigrade has occurred over the past century, and further …

Cryopreservation Of Reproductive Cells And Tissues, Guanglei Li

LSU Master's Theses

Cryopreservation of reproductive cells and tissues is a useful technique to deliver intact genomes, maximize the distribution of favorable genes, control disease spread. It is widely applied to many fields such as biology, medicine, ecology and agriculture. To optimize the cryopreservation procedure, the biophysical responses of reproductive tissues at different cooling conditions and in different mediums must be clearly understood. Here we studied the biophysical response during freezing of: 1) bovine sperm frozen at a cooling rate of 20 ˚C/min in three media: without cryopreservation agents(CPAs), with 0.7 M glycerol, and with 0.7 M glycerol along with 1.5 mg/ml of …

Development Of Non-Dairy Frozen Dessert Containing Soy Protein And Coconut Milk, Luciana Soler

LSU Master's Theses

As consumers have pursued healthier lifestyles in recent years, consumption of soy foods has risen steadily, encouraged by scientific studies showing health benefits from these products. There is a large market for ice cream in the United States. However, since ice cream contains dairy ingredients, a number of Americans are not able to consume it because of dietary habits due to religious beliefs, lactose intolerance, vegetarianism or other related ideologies. For years, these groups of consumers have been able to substitute ice cream with frozen desserts containing soy protein as a substitute for milk protein, but never in the United …

A Correlational Study Examining The Relationship Between Invented Spelling And Beginning Reading, Jane Mcdaniel Grove

LSU Doctoral Dissertations

This research study was designed to investigate correlations between invented spelling patterns and beginning reading for low-performing and on-level boys and girls in kindergarten. Two research questions were examined: (1) Is there a statistically significant relationship between invented spelling as displayed in task and reading skills as measured by DIBELS? and (2) Does the performance displayed in task and reading skills as measured by DIBELS differ significantly for boys and girls in kindergarten? Student performance data was gathered using extant school Dynamic Indicators of Basic Early Literacy Skills (DIBELS) benchmarks at collected at midyear of kindergarten. It was hypothesized that …

Ecotoxicology Of Metal-Hydrocarbon Mixtures In Benthic Invertebrates, Kurt A. Gust

LSU Doctoral Dissertations

Metal-hydrocarbon mixtures are becoming increasingly prevalent in natural environments due to expanding industrial activity and urbanization. The ecotoxicology of metal-hydrocarbon mixtures in benthic environments is of particular concern because both classes of contaminants partition to sediments and can thereby exert toxic effects in benthic organisms. Mixtures of dissimilar chemicals (including metals and hydrocarbons) are broadly hypothesized to elicit independent toxic effects however; this hypothesis has little supporting data. The purpose of this dissertation was to test this hypothesis for metal-hydrocarbon mixtures using environmentally relevant exposures and to determine mechanisms for observed interactive effects. Sediment and water-only bioassays were conducted employing …