Digital Commons Network^™

Apolipoprotein Status And Cognitive Functioning In Adulthood: Role Of Physical Health And Social Network Characteristics, Jennifer Lee Silva

LSU Doctoral Dissertations

This study examined the relationships among cognitive function, physical health, social network characteristics, and apolipoprotein (APOE) genotype in participants from the Louisiana Healthy Aging Study. Prior literature has shown that the ε4 allele of APOE is associated with cognitive deficits (Wisdom, Callahan, & Hawkins, 2009). This study failed to find any relation between APOE genotype (ε4 carrier vs. non-carrier) and cognitive ability after controlling for age and education level. Tests for physical health mediation and social network moderation did not alter the ε4/cognition null results. This finding conflicts with prior research suggesting that physical activity and health modify the association …

Cbod₅ Treatment And Nitrogen Transformations Of The Marshland Upwelling System In Intermediate And Saltwater Marshes, Lorna Anne Putnam

LSU Doctoral Dissertations

The marshland upwelling system (MUS) was designed to treat domestic wastewater from coastal dwellings where conventional methods are inadequate due to high water tables, poor hydraulic soil conditions, anaerobic soils, and saline groundwater. Currently there is no adequate treatment system available and coastal dwellings are contributing to water quality problems. This study focused on determining the treatment effectiveness of the MUS for organic matter and understanding the specific processes involved in nitrogen treatment.

The treatment of organic matter, measured as five-day carbonaceous biological oxygen demand (CBOD₅), was effective in field tests for both saltwater and intermediate marshes. Global …

Characterization Of The 'Glutamate Effect' On The Solution Thermodynamics And Function Of The Large Fragments Of The Type I Dna Polymerases From E.Coli And T.Aquaticus, Daniel J. Deredge

LSU Doctoral Dissertations

In this study, it is shown that the large fragments of the type I DNA polymerase from E.coli (Klenow) and T.aquaticus (Klentaq) display enhanced DNA binding affinity in glutamate vs. chloride. Across the relatively narrow salt concentration ranges often used to obtain salt linkage data, Klenow also displays an apparently decreased linked ion released (¦¤n_ions) in Kglutamate vs. KCl while Klentaq does not display such an effect. The osmotic stress technique reveals that Klenow and Klentaq DNA binding is associated with the release of ~500 to 600 waters in KCl. For both proteins, replacing chloride with glutamate results …

Distribution, Diversity And Ecology Of Aerobic Carbon Monoxide-Oxidizing Bacteria In Hawaiian Volcanic Deposits, Carolyn Frances Weber

LSU Doctoral Dissertations

Carbon monoxide-oxidizing bacteria are among the first colonists of recently formed volcanic deposits despite environmental conditions that challenge their survival, such as oscillating water regimes and lack of endogenous sources of organic carbon and nitrogen. Activity assessments and molecular surveys of the coxL gene (large subunit carbon monoxide dehydrogenase) across a vegetation gradient on a 1959 volcanic deposit on Kilauea Volcano (Hawai’i) indicated that CO-oxidizing communities continue to expand, diversify and remain competitive during ecosystem development. Distinct compositional shifts occurred across the gradient with Firmicutes-like coxL sequences dominating clone libraries from unvegetated sites (Bare) and Proteobacteria coxL sequences dominating libraries …

Evolution Of Vocal Signals In A Neotropical Avian Lineage, Brian J. O'Shea

LSU Doctoral Dissertations

In this dissertation I explored variation in vocalizations of the avian genus Synallaxis (Passeriformes: Furnariidae) and the use of vocal characters to determine phylogenetic relationships at the species level. Vocalizations of suboscine passerines have recently gained favor as a proxy for genetic material in systematic studies; however, individual and geographic variation are both widespread in suboscines, complicating the definition and analysis of vocal characters. This is particularly true for species that have simple, phylogenetically conserved vocalizations. Moreover, the use of vocal characters in suboscine systematics depends on the confident assessment of homologous vocalizations, as well as a thorough understanding of …

Studies On The Effect Of Natural Organic Matter And Hydration On The Sorption And Desorption Of Trifluorinated Pesticides, Charisma Vinarao Lattao

LSU Doctoral Dissertations

This work was done in order to deepen our molecular level understanding of how soil organic matter (SOM) is assembled in a whole soil and to provide further insight on the effect of SOM assembly on the uptake and release of hydrophobic organic compounds. Various techniques, including ultraviolet absorbance, fluorescence, and total carbon analysis, demonstrate that hydration/solvation of SOM is kinetically controlled. Initial wetting of a soil releases the hydrophobic moieties that are located at the outer surface of SOM, and longer wetting times exfoliate more hydrophobic quinone type moieties that are present in the middle layer, which in turn …

Categorization And Indentification Of Mechanisms Of Sugarcane Resistance To The Sugarcane Aphid (Hemiptera: Aphididae), Waseem Akbar

LSU Doctoral Dissertations

Sugarcane in Louisiana is colonized and sometimes heavily infested by two aphid species, the sugarcane aphid, Melanaphis sacchari (Zehntner), and the yellow sugarcane aphid,Sipha flava(Forbes). Melanaphis sacchari, the main vector of sugarcane yellow leaf virus, is distributed throughout Louisiana’s sugarcane-growing regions. Five cultivars representing 90% of the commercial acreage in Louisiana (LCP 85-384, HoCP 91-555, Ho 95-988, HoCP 96-540,L 97-128) were evaluated for resistance to aphids in the greenhouse. Antibiosis was the primary category of resistance to both aphid species. Based on the intrinsic rate of natural increase, L 97-128 and HoCP 91-555 were comparatively susceptible and resistant cultivars, respectively. …

Effects Of An Audience Response System On Student Learning Outcomes In An Applied Kinesiology Course, Katherine Krieg

LSU Doctoral Dissertations

The purpose of this study was to examine the effects of using audience response systems (ARS) on student learning outcomes and learning processes, when the instructional strategy of using sequentially challenging questions and collaborative discussions were held constant across both treatment and control conditions. A quasi-experimental AB alternating research design was employed. Two sections of a Functional Anatomy and Kinesiology course at a small faith-based college participated in the study. One section served as control and the other section as treatment groups until midsemester, when the roles of the groups switched. Both quantitative and qualitative data were collected and analyzed. …

A Modular Approach To Lung Nodule Detection From Computed Tomography Images Using Artificial Neural Networks And Content Based Image Representation, Omer Muhammet Soysal

LSU Doctoral Dissertations

Lung cancer is one of the most lethal cancer types. Research in computer aided detection (CAD) and diagnosis for lung cancer aims at providing effective tools to assist physicians in cancer diagnosis and treatment to save lives. In this dissertation, we focus on developing a CAD framework for automated lung cancer nodule detection from 3D lung computed tomography (CT) images. Nodule detection is a challenging task that no machine intelligence can surpass human capability to date. In contrast, human recognition power is limited by vision capacity and may suffer from work overload and fatigue, whereas automated nodule detection systems can …

Insights Into The Streptomycete Conjugation Mechanism And Interstrain Inhibitor Production By The Sweet Potato Pathogen Streptomyces Ipomoeae, Jing Wang

LSU Doctoral Dissertations

Conjugation in Streptomyces invokes a unique mechanism involving few plasmid-encoded loci. Transfer of circular plasmid pIJ101 requires only a tra gene, and a cis-acting locus clt. Here, I investigated whether the transfer genes of pIJ101 could promote transfer of a linear plasmid. While pIJ101 Tra could transfer circularized versions of the linear plasmid containing clt, the linear plasmid itself could not be transferred efficiently by Tra. All plasmids isolated from transconjugants appeared to be circular regardless of the configuration of the plasmid in the initial donor cells. However the linear plasmid could be transferred in linear form from JW1, which …

Influence Of Cultural Practices And Herbicides On Torpedograss [Panicum Repens (L.) Beauv.] Infestation In Centipedegrass [Eremochloa Ophiuroides (Munro, Hack)], James Taverner

LSU Master's Theses

Torpedograss (Panicum repens L. Beauv.) is a common weed problem along the Gulf Coast in highly managed turf. Non-selective herbicides are currently used to control torpedograss within centipedegrass [Eremochloa ophiuroides (Munro) Hack.] and St. Augustinegrass [Stenotaphrum secundatam (Walt.) Kuntze], but turfgrass injury can be extensive. Research was conducted to evaluate torpedograss and centipedegrass response to the application of the selective, post-emergence herbicides quinclorac, sethoxydim, and clethodim. Quinclorac applied at 0.42 kg ai ha-1 three times 4 wks apart reduced torpedograss to 25% coverage (55% of control) 10 weeks after initial treatment (WAIT), but re-establishment was rapid and by 16 WAIT …

Comparative Phylogeography Of Neotropical Birds, Curtis Wade Burney

LSU Doctoral Dissertations

Despite the theoretical link between the ecology and the population genetics of species, little empirical evidence is available that corroborates the association. Here, I examined genetic variation in 40 co-distributed species of lowland Neotropical rainforest birds that have populations isolated on either side of the Andes, Amazon River, and Madeira River. I found widely varying levels of genetic divergence among these taxa between the same biogeographic barriers. My investigation of the extent to which ecological traits predicted the level of cross-barrier divergence revealed a significant relationship between the forest stratum at which a species forages and the level of within-population …

A Critical Examination Into Motivation And Gender In Youth Physical Fitness Testing, Elizabeth A. Domangue

LSU Doctoral Dissertations

Fitness testing in physical education classes has emerged as an important component in efforts to assess and address health concerns related to children’s physical inactivity. To date, motivational aspects of fitness testing, especially in regard to students’ future intention to participate in fitness-related activities, have not been closely examined. Fitness testing practices have been identified as a dominant discourse in physical education that continue to separate girls’ and boys’ physicalities along gendered lines. This lack of understanding about the motivational implications of fitness testing programs, coupled with concerns related to the gendered nature of fitness testing, emphasize the significance of …

Functional Implications Of The Neuromuscular Transform In Decapod Crustacean Locomotion, Richard Burkett Dewell

LSU Doctoral Dissertations

All animals face the same basic challenges in controling movement through their environment. The central nervous system must activate and effectively control muscle fibers capable of accomplishing the behavior. For multi functional muscles, an array of muscle fiber types must be selectively activated based on the behavioral task. In arthropods that have few motor neurons, it is not understod how the nervous system accomplishes this selective activation. If the selection cannot be achieved by recruitment of different motor neurons, then it most likely results from careful adjustment to the firing patterns of the motor neurons. I used the neuromuscular system …

Evidence That The Boundary Element-Associated Factors Beaf-32a And Beaf-32b Affect Chromatin Structure In Drosophila Melanogaster, Matthew Kenneth Gilbert

LSU Doctoral Dissertations

The Boundary Element-Associated Factors, BEAF-32A and BEAF-32B bind to hundreds of loci on Drosophila chromosomes. These proteins function as insulators; they can prevent promoter activation by an enhancer when placed between them and protect transgenes from chromosomal position effects. To gain insight into BEAF function we designed and expressed a transgene encoding a dominant-negative form of BEAF. This peptide, BID, consists of the BEAF self-interaction domain. We demonstrate here that this peptide interferes with BEAF’s ability to bind DNA and prevents it from functioning as an insulator. In addition, expression of BID leads to a global disruption of polytene chromosome …

Integrated Management Of Creeping Rivergrass In Rice, Sunny Lynn Bottoms

LSU Doctoral Dissertations

Studies were conducted to evaluate growth and reproductive capabilities of creeping rivergrass in response to flood depth, burial depth, desiccation, herbicide programs and interference with rice. Seed production of a natural population of creeping rivergrass was 0.8 seeds per panicle. Germination was 45% and seedling vigor was poor. Flowers from surviving seedlings were male sterile. A 5 and 10 cm flood depth increased fresh weight, stolon length, and node production of creeping rivergrass compared with non-flooded plants. However, depths at 15 and 20 cm did not differ from no-flood; therefore permanent flooding should be delayed until rice can survive a …

A Social Vulnerability-Based Genetic Algorithm To Locate-Allocate Transit Bus Stops For Disaster Evacuation In New Orleans, Louisiana, Xiaojun Qin

LSU Master's Theses

In the face of severe disasters, some or all of the endangered residents must be evacuated to a safe place. A portion of people, due to various reasons (e.g., no available vehicle, too old to drive), will need to take public transit buses to be evacuated. However, to optimize the operation efficiency, the location of these transit pick-up stops and the allocation of the available buses to these stops should be considered seriously by the decision-makers. In the case of a large number of alternative bus stops, it is sometimes impractical to use the exhaustive (brute-force) search to solve this …

Computational Studies On Fatty Acid Synthesis: From Mechanisms To Drug Design, Matthew Edward Mckenzie

LSU Doctoral Dissertations

The first committed steps of the Fatty Acid synthesis pathway involves the de/carboxylation reactions of biotin. By understanding this step, potential novel antimicrobial agents could be discovered. The current tools of drug discovery can only help the research in finding and modifying potential hits. Finding a lead candidate from these programs are often equated to finding a needle in a haystack, which is due to the many assumptions used in molecular docking. The fundamental reaction kinetics can not be described by these techniques and a detailed study of the decarboxylation reaction is investigated using ab initio molecular dynamics. In this …

Under Construction: Recollecting The Museum Of The Moving Image, Andr&Eacutee Elise Comiskey Betancourt

LSU Doctoral Dissertations

On February 27, 2008 the Museum of the Moving Image launched its $65 million renovation and expansion with a digital groundbreaking. Since opening its doors in Astoria, New York in 1988, the museum, originally devoted to film and television, has embraced digital media. From its “Hollywood East” Astoria Studio historic landmark site to its popular website, the Museum of the Moving Image provides a unique setting for studying the museumification of moving image culture, particularly the production and consumption of moving images. In response to the Museum of the Moving Image’s domestication of moving image culture in its core exhibition, …

Psychopathology In Person With And Without Co-Morbid Autism, Martin Nicholas Ancona

LSU Doctoral Dissertations

Autism and intellectual disability are frequently co-occurring. In addition, a diagnosis of mild, moderate, severe, or profound intellectual disability increases the risk for co-occurring Axis I psychiatric disorders. This study utilized multivariate analyses of variance (MANOVA) to determine whether mean differences exist across three diagnostic groups: ID only, ID and autism, and ID and pervasive developmental disorder not otherwise specified (PDD-NOS) on the linear combination of subscales present on the Diagnostic Assessment of the Severely Handicapped-II (DASH-II), a psychometrically sound measure that assesses psychopathology in those with ID. The results of this study supported an association between the presence of …

Children Of Men: The American Jeremiad In Twentieth And Twenty-First Century Science Fiction And Film, Joseph Franklin Brown Jr.

LSU Doctoral Dissertations

This dissertation considers the dynamic and resilient influence of the jeremiad, an early American religious and literary mode, on contemporary American literature and culture. It argues that the polemical, dystopian, and apocalyptic narratives so abundant in twentieth-century literature and film participate in an ingrained literary tradition that accounts for society's misfortunes as penalty for its social and moral evils while, at the same time, emphasizing an American exceptionalism born out of a belief in the society's election through its covenant with God. The project makes connections between early-American texts and related works of twentieth and twenty-first century American literature and …

Capillary Electrophoretic Separations Of Enzyme Inhibitors With Activity-Based Detection, Xiaoyan Yan

LSU Master's Theses

A technique for separating and detecting enzyme inhibitors was developed using capillary electrophoresis with an enzyme microreactor. The on-column enzyme microreactor was constructed using one or two NdFeB magnets in two configurations to immobilize alkaline phosphatase-coated superparamagnetic beads with diameters of 2.8 µm inside a capillary before the detection window. Enzyme inhibition assays were performed by injecting a plug of inhibitor into a capillary filled with an alkaline phosphatase substrate, AttoPhos. Product generated in the enzyme microreactor was detected by laser-induced fluorescence. Inhibitor zones electrophoresed through the capillary, passed through the enzyme microreactor, and were observed as negative peaks due …

Characterization Of Porcine Adipose Tissue-Derived Stem Cells, Kellie J. Williams

LSU Doctoral Dissertations

Nuclear transfer (NT) results in low success rates and research has reported problems with the welfare of cloned animals produced. Evidence suggests the use of a less differentiated donor cell, such as a stem cell, may lead to an increase in the efficiency of the NT procedure. Stem cell characteristics must be clearly defined in order to isolate, identify and optimally culture potential donor cells. Stem cell characteristics such as self-renewal and differentiation have not been identified in stem cells from porcine adipose tissue, an easily attainable tissue resource. The phenotypic profile of cell surface proteins and chromosomal stability of …

Dna Topoisomerases I From Pseudomonas Aeruginosa And Vaccinia Virus And Their Use As Drug Targets, Teesta Jain

LSU Doctoral Dissertations

Pseudomonas aeruginosa encodes a putative topoisomerase with sequence similarity to the type IB topoisomerase enzyme from vaccinia virus. Residues in the active site are conserved, notably Tyr292 which would be predicted to form the transient covalent bond to DNA. The gene encoding the P. aeruginosa topoisomerase I (PAT) was cloned and expressed in E. coli. The enzyme relaxes supercoiled DNA, while a mutant of P. aeruginosa containing a Tyr292 to Phe substitution at the active site was found to be catalytically inert. This is consistent with the role of Tyr in forming the covalent intermediate. Like vaccinia topoisomerase (VT), PAT …

The Economic Importance And Management Of Mercury Contamination In Pelagic Fisheries, Tina Marie Willson

LSU Doctoral Dissertations

The presence of mercury in the U.S. fish supply is a growing public health concern. At high levels, mercury can be harmful to humans and ecosystems, and represents a growing threat not only to public health, but also to the economic and ecological viability of many fisheries. This research examined the economic issues surrounding mercury contamination in fish, developed a population dynamics and bioeconomic model to investigate the problem, and compared a variety of management actions to reduce consumer exposure to contaminants. The dissertation begins with an overview of contamination issues in U.S. fisheries, including a review of the historical …

Remediating Impacts Of Global Climate Change-Induced Submergence On Salt Marsh Ecosystem Functions, Camille Lafosse Stagg

LSU Doctoral Dissertations

Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase the elevation of the marsh surface, thus ameliorating the effects of excessive inundation. Although this technique is growing in popularity, the successful restoration of ecological function after sediment addition has received little attention. The purpose of this research was to determine if sediment subsidized salt marshes are functionally equivalent to natural marshes and whether salt marshes …

Experimental Design, Synthesis And Application Of Molecular Micelle Modified Polymeric Nanoparticles For Drug Delivery Systems And Free Radical Detection, Gabriela M. Ganea Visser

LSU Doctoral Dissertations

Biodegradable and biocompatible polymeric nanoparticles such as poly (lactide-co-glycolide) (PLGA) nanoparticles have been extensively studied as drug delivery systems for a variety of pharmaceutical agents. Nanoparticle surface properties are primarily determined by the emulsifiers used in the synthesis process, which have a significant impact on nanoparticle physico-chemical and biological properties. Anionic amino acid – based molecular micelles were used in the emulsification process to prepare monodisperse, small (below 100 nm) PLGA nanoparticles with a well defined spherical shape. Such molecular micelle – modified nanoparticles were used as drug carriers for delivery of antioxidants. Thymoquinone is a natural antioxidant, and an …

Isoflavone Distribution In Soy Seed And Antioxidant Activity Of Defatted Soy Flour Extract, Xiaohua Yue

LSU Doctoral Dissertations

Soy isoflavones distribution in soy cotelydon, coat and germ were determined. The ƒÀ-Glucoside form of isoflavones was the major class of isoflavones in all three soy parts. Soy germ was the richest source of the isoflavones among the three soybean parts. Distribution of the isoflavones in soy cotyledon was different from that in soy coat or germ. As defatted soy flour is a main byproduct in the soy oil refining process, utilizing the low value byproduct as a valuable food antioxidant was investigated in this study. The level of isoflavones in the defatted soy flour extract was 55 mg/g, which …

Bacterial Characterization Of Louisiana Groundwater Contaminated By Dnapl-Containing Chloroethanes And Other Solvents, Kimberly Bowman

LSU Doctoral Dissertations

In support of an effort to determine the feasibility of using an in-situ bioremediation strategy for cleanup of groundwater in an area containing chlorinated solvents present as a dense non-aqueous phase liquid (DNAPL), the bacterial population in the groundwater at a Superfund site located near Baton Rouge, Louisiana was characterized. More than 3¡Á107 cells/mL in the groundwater were observed via microscopy. Universal bacterial and ¡°Dehalococcoides¡±-specific 16S rRNA gene libraries were constructed and analyzed. Universal clones grouped into 18 operational taxonomic units (OTUs), as defined by sequence similarity ¡Ý97.0%, which included several as yet undescribed organisms. Multiple unique sequences closely related …

Using Demographic Models To Manage Chinese Privet (Ligustrum Sinense Lour.), Metha Martine Klock

LSU Master's Theses

Colonization of natural areas by Chinese privet (Ligustrum sinense Lour.) threatens biodiversity and preservation of native habitat in the southeastern United States. High rates of seed production and dispersal, coupled with clonal growth, result in a competitive advantage when introduced to novel areas. Land managers have attempted to control L. sinense through prolonged flooding, prescribed fire, and herbicide application with little success. I determined presence of L. sinense invasion in four sites in Louisiana and assessed key reproductive, growth, and survivorship characteristics defining its life course. I used vegetation surveys, germination trials, dendrochronology, and demographic models to elucidate stages in …