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Oxidation Of Reduced Sulfur Compounds: A Triple-Oxygen-Isotope Perspective, Issaku E. Kohl

LSU Doctoral Dissertations

The Earth’s geochemical evolution is recorded in the rocks that compose its lithosphere. Specifically, sulfate minerals have been identified as being repositories of information concerning the past hydrosphere, atmosphere and biosphere. This is due to the non-labile nature of SO42- and its ability to store a record of the oxidative reactions and oxygen sources involved in its formation. Microbial dissimilatory sulfate reduction (MDSR) and sulfide oxidation cause oxygen from H2O and O2 to be trapped to varying degrees in ambient, dissolved SO42-. In order to better interpret the H2O and O2 signals in SO42-, we must deepen our understanding of …

Modeling And Simulation For Shape Memory Polymer Based Self-Healing Syntactic Foam, Wei Xu

LSU Doctoral Dissertations

Syntactic foams, renowned for their low density and high mechanical properties, are enjoying continuing growth in various civilian and military sectors. However, like laminated composites, foam cored structures are vulnerable to impact damages and suffering from inabilities in repairing macro-scale cracks. A self-healing mechanism for structural damage is genuinely desired. A recent development in self-healing structural damage is a two-step close then heal (CTH) scheme proposed by Li and Nettles [1] and elucidated by Li and Uppu [2], by mimicking the self-healing process of human skin. This concept has been further demonstrated in Nji and Li’s work [3] that a …

Study Of Host-Fungus Interactions Between Soybean And Phakopsora Pachyrhizi Using Proteomics, Sunjung Park

LSU Doctoral Dissertations

Asian soybean rust, caused by Phakopsora pachyrhizi, is an emerging disease in the continental U. S. and resistant commercial varieties have not been reported. In an effort to understand the interactions during rust infection of soybean, protein profile changes were examined over a 14-day period in soybean leaves of one susceptible commercial line (Pioneer 93M60) with or without soybean rust inoculation using proteomics in this study. Forty protein spots differentially expressed after rust inoculation were identified and fourteen of them were recovered and sequenced. These included proteins involved in plant defense, stress, metabolism, and other biological processes. During the time-course …

A Peptide-Based Platform For Displaying Antibodies To Engage T Cells, Ying Zheng

Electronic Theses and Dissertations

This study investigated a strategy by which antibodies were displayed on a gel-like substance to engage T cells. The substance, a peptidic composite, was characterized in vitro and explored as an injectable system in vivo. The composite consists of two amphiphilic peptides, AEAEAKAKAEAEAKAK (referred to as "EAK") and AEAEAKAKAEAEAKAKHHHHHH ("EAKH6"). Spectroscopic analysis showed the two peptides integrated into a single structure. Prior to combination, conformational analysis revealed that EAKH6 adopts a mixed alpha-helix/bata-strand conformation. In the presence of EAK, EAKH6 exists predominantly in a beta;-strand conformation. Using nickel-bound horseradish peroxidase as a probe, the composite of EAK-EAKH6 was found to …

A Study Of The Interactions Of Lipid Bilayers And Dendrimers Using Small Angle X-Ray Scattering And Freeze Fracture Transmission Electron Microscopy, Derek R. Dorman

LSU Doctoral Dissertations

Lipids are fundamental to all life forms, a key component of cell walls, and essential to proper respiratory function. They are amphiphilic molecules and readily form bilayers. Dendrimers are designer molecules that can be tailored to provide a variety of endgroup moieties, sizes, and charges. The interaction of liposomes and dendrimers can provide information on how medicine interacts with cells and an array of unique structures can be imagined from their assembly into superstructures. Polypropylenimine tetraamine (DAB-Am) and 1-directional arborol dendrimers have been studied in different molar concentrations with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers. One-directional arborols are amphiphilic dendrimers with a hydrophilic …

Classical And Nonclassical Antifolates: Synthesis Of Furo-[2,3-D] Pyrimidines Pyrrolo[2,3-D]Pyrimidines And Pyrimido-[4, 5-B]-Indoles, Lei Wang

Electronic Theses and Dissertations

The dissertation will give an introduction, background and our research progress in the areas of antifolates. The design and synthesis of both classical and nonclassical bicyclic furo[2,3-d]pyrimidines, pyrrolo[2,3-d]pyrimidines and tricyclic pyrimido[4,5-b]indoles as potential antifolates have been described. As a part of this study, a total of one hundred and fifty-three new compounds have been synthesized and characterized. Of these, sixty-seven final compounds were submitted for biological evaluation.

Dynamic Model Of Ecological Factors Impacting The Gulf Of Mexico Dead Zone, Jimmie Arnold Brumfield Ii

LSU Doctoral Dissertations

The industrial agriculture complex of the Mississippi River Drainage Basin has the positive effect of feeding more individuals with less land via the use of chemical nutrients, pesticides and drainage. The negative effects of the agricultural nutrient load are carried by the Mississippi River to the Gulf of Mexico. After the flood of 1927 the Flood Control Act of 1928 began changing the Mississippi River into a navigation and flood control project. While successful, the river was turned into a channel where nutrient input was discharged into the Gulf of Mexico. Nitrogen compounds discharged from the Mississippi are claimed to …

Synthesis Of Bicyclic Pyrrolo[2,3-D]Pyrimidines, And Tricyclic Indeno[2,1-D]/[1,2-D]Pyrimidines As Receptor Tyrosine Kinase (Rtk) Inhibitors And Antimitotic Agents, Ying Zhao

Electronic Theses and Dissertations

The dissertation will give an introduction, background and our research progress in the areas of receptor tyrosine kinases inhibitors and antimitosis inhibitors. The design and syntheses of bicyclic pyrrolo[2,3-d]pyrimidines, and tricyclic indeno[2,1-d]- and [1,2-d]pyrimidines as receptor tyrosine kinase inhibitors and bicyclic pyrrolo[2,3-d]pyrimidines, and tricyclic indeno[2,1-d]pyrimidines as antimitotic inhibitors have been described. As a part of this study, a total of two hundred and eleven new compounds have been synthesized and characterized. Of these, ninety five final compounds were submitted for biological evaluation.

Synthesis And Characterization Of Rare Earth-Nickel-Gallium Ternary Intermetallics, Kandace R. Thomas

LSU Doctoral Dissertations

The structural and physical characterization of several early and latter rare earth Ln-Ni-Ga systems, which include Ln2NiGa12 (Ln = Pr, Nd, Sm), alpha-LnNiGa4 (Ln = Y, Gd – Yb) and beta-LnNiGa4 (Ln = Tb – Ho) will be presented in this work. These systems are thermodynamically located within a copious, robust phase space and provide a rich understanding of how slight modifications to synthetic preparations can yield the adoption of different structure types in a Ga-rich regime. Each of these phases is made up of well-studied substructures which lend an additional angle of apperception as to how their structure and …

Pharmaceutical Compounds In Treatment Wetlands: Potential Removal And Effects On Microbial Processes, Jeremy Landon Conkle

LSU Doctoral Dissertations

active compounds (PhACs) have been detected in the aquatic environment as a result of loading from various sources. In Louisiana, USA, many municipalities treat wastewater using natural systems, such as lagoons and wetlands, rather than using conventional wastewater treatment technologies and may discharge PhACs into the environment. These treatment systems are not designed to remove PhACs from wastewater, nor is it currently a regulatory requirement. Research on the fate of PhACs in the environment is needed to understand impacts on Louisiana’s important coastal system. Wastewater sampling for PhACs at the Mandeville, LA wastewater treatment plant (WWTP) determined that this system …

Structure And Organization Of Canopy Bird Assemblages In Lowland Neotropical Rainforests, David Lawrence Anderson

LSU Doctoral Dissertations

Although birds of the forest canopy are an important component of tropical forest ecosystems, difficulty accessing the forest canopy has limited the advancement of knowledge pertaining to this group of species. Here I test methods for the study of canopy birds in lowland Neotropical rainforests, and identify recurring patterns of community structure in canopy bird assemblages as well as processes potentially responsible for these patterns. I used three methods to assess differences in ground-based and canopy-based methods for detecting forest birds in a 100-ha plot of lowland rainforest in northern Honduras: (1) point counts from the ground; (2) repeat censuses …

Endocrine Disruptors And Obesity: An Examination Of Selected Persistent Organic Pollutants In The Nhanes 1999-2002 Data, Mai A. Elobeid, Miguel A. Padilla, David W. Brock, Douglas M. Ruden, David B. Allison

Psychology Faculty Publications

Recent evidence suggests that endocrine disrupting chemicals (EDCs) may cause perturbations in endogenous hormonal regulation that predispose to weight gain. Using data from NHANES (1999-2002), we investigated the association between body mass index (BMI), waist circumference (WC) and selected persistent organic pollutants (POPs) via multiple linear regressions. Consistent interaction was found between gender, ln oxychlordane and ln p,p' DDT. Also, we found an association between WC and ln oxychlordane and ln hpcdd in subjects with detectable levels of POPs, whereas an association between WC and ln p,p' DDT was observed in all subjects. Furthermore, ln Ocdd showed an increase with …

Predator-Prey Interaction In Estuarine Bivalves: Size Selection, Effects Of Salinity, And Indirect Interactions, Barry Richard Aronhime

LSU Doctoral Dissertations

High stress environments can reduce species diversity. How such stress-induced reduction in predator diversity impacts prey survival is less well studied. Brackish waters in estuaries are stressful, species depauperate areas, but also prime oyster habitat in Louisiana. Surveys revealed reduced bivalve predator diversity at the low salinity (high stress) site. Exclosure experiments indicated highest prey mortality at the high salinity (low stress) site. Predator enclosures corroborated the field study results, with reduced consumption rates at the low salinity site for both stone crabs, Menippe adina and oyster drills Stramonita haemastoma, but not blue crabs, Callinectes sapidus. Blue crab mortality in …

Spatial Analyses Of Pedosphere Carbon Stock And Sequestration Potential In Louisiana's Watersheds, Biao Zhong

LSU Doctoral Dissertations

This dissertation research aimed to quantify current soil organic carbon (SOC) stocks across Louisiana’s landscape, examine the spatial relationships between SOC and terrain factors at the watershed and river basin scales, and predict SOC changes in surface soils during future climate change. Using Louisiana as an example, a spatially-explicit modeling framework was developed that is conducive to watershed-scale prediction of soil carbon stock and change. SOC densities at the watershed scale were estimated using the USDA NRCS Soil Geographic Database (STATSGO). Louisiana watersheds and National Land Cover Database (NLCD) were used to aggregate total soil carbon and estimate average soil …

Modulation Of Cholinergic Signaling In Embryonic Zebrafish: Anatomical And Behavioral Consequences, Evdokia Menelaou

LSU Doctoral Dissertations

Smoking during pregnancy remains a major health concern in the United States. Nicotine is one of the main ingredients of cigarettes and a neurotoxicant which has been purported to affect many aspects of nervous system development causing long-term abnormalities in the offspring. We took advantage of the zebrafish model to investigate the effects of nicotine in nervous system anatomy and function. It was previously reported that embryonic nicotine exposure causes pathfinding errors in secondary motoneuron (SMN) axons through the activation of nicotine acetylcholine receptors (nAChRs). However, the nicotine-induced effects on SMN pathfinding coincided with muscle degeneration. We hypothesized that nicotine …

Sorption Mechanisms Of Zinc In Different Clay Minerals And Soil Systems As Influenced By Various Natural Ligands, Mohammed Hashem Stietiya

LSU Doctoral Dissertations

The bioavailability and fate of Zinc (Zn) in soils is influenced by reactions occurring at the water-mineral interface. Understanding Zn interaction with mineral surfaces is essential to the understanding of Zn fate and toxicity. In this study, adsorption experiments investigated the impact of ligands and pH on the adsorption of Zn to mineral surfaces. X-Ray Absorption Fine Structure Spectroscopy (XAFS) was used to elucidate the adsorption mechanisms of Zn to mineral surfaces as impacted by ligands. Impact of ligands on Zn adsorption was dependent on mineral type and pH of the system. XAFS analysis showed that adsorption mechanisms of Zn …

Parent Education In A Child Welfare Setting: Understanding Maltreatment Following An Intervention For Parents And Their Infants, Toddlers, And Pre-School Children, Rhenda Hotard Hodnett

LSU Doctoral Dissertations

Child abuse and neglect is a complex, multi-faceted problem that often has lifelong, negative consequences for its victims; most significantly affecting infants, toddlers and pre-school age children. Parenting classes are the most common intervention used by child welfare agencies as a means to prevent repeat maltreatment, yet there is very little research involving these targeted families. Prior research has primarily focused on the prevalence of and risk factors for child maltreatment, with much less attention on specific parenting program outcomes as implemented in a child welfare setting. In 2005, focusing on a more deliberate and systematic approach in the use …

Edaphic And Vegetative Controls On Mercury Cycling In Oligohaline Wetlands, Jonathan M. Willis

LSU Doctoral Dissertations

With the expansion of the human population and associated industries there is a concomitant increase in both resource utilization and the production of waste and deleterious by-products. Mercury is a naturally-occurring toxic metal with a complicated and unique biogeochemical cycle, and is often a contaminant of ecotoxicological concern in unindustrialized aquatic habitats. The research described herein was designed to elucidate multiple aspects regarding the behavior of mercury in oligohaline wetland habitats, particularly with respect to edaphic and vegetative effects, through a monitoring and characterization study as well as a series of manipulative experiments. The observational study, conducted in the wetlands …

Model Based Analysis Of Some High Speed Network Issues, Suman Kumar

LSU Doctoral Dissertations

The study of complex problems in science and engineering today typically involves large scale data, huge number of large-scale scientific breakthroughs critically depends on large multi-disciplinary and geographically-dispersed research teams, where the high speed network becomes the integral part. To serve the ongoing bandwidth requirement and scalability of these networks, there has been a continuous evolution of different TCPs for high speed networks. Testing these protocols on a real network would be expensive, time consuming and more over not easily available to the researchers worldwide. Network simulation is well accepted and widely used method for performance evaluation, it is well …

Microfluidic Devices Interfaced To Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry For Proteomics, Jeonghoon Lee

LSU Doctoral Dissertations

Microfluidic interfaces were developed for off-line matrix-assisted laser desorption/ionization mass spectrometry (MALDI). Microfluidic interfaces allow samples to be manipulated on-chip and deposited onto a MALDI target plate for analysis. For this research, microfluidic culturing devices and automated digestion and deposition microfluidic chip platforms were developed for the identification of proteins. The microfluidic chip components were fabricated on a poly(methyl methacrylate), PMMA, wafer using the hot embossing method and a molding tool with structures prepared via micromilling. One of the most important components of the chip system was a trypsin microreactor. An open channel microreactor was constructed in a 100 µm …

Caring Attitudes Among Child Welfare Caseworkers: Associations With Client Participation In Services, Karen Faulk

LSU Doctoral Dissertations

The purpose of this study was to determine if there is an association between the caring attitudes and commitment toward clients of child welfare workers and their clients’ completion of a parenting education program. This line of inquiry is intended to expand the scope of research on caring attitudes associated with child welfare workers intent to remain employed. A logical extension of identifying characteristics associated with child welfare workforce retention is to determine if those characteristics are also associated with positive client outcomes. Part of the examination of worker caring attitudes involved testing the Child Welfare Inventory (CWI), a modified …

The Roles Of Transcription Factors In Nucleotide Excision Repair In Yeast, Baojin Ding

LSU Doctoral Dissertations

Nucleotide excision repair (NER) is a conserved DNA repair mechanism capable of removing a variety of helix-distorting lesions, such as UV-induced cyclobutane pyrimidine dimers (CPDs). NER can be grouped into two pathways: global genomic NER (GGR), which refers to repair throughout the genome, and transcription coupled NER (TCR), which refers to a repair mechanism that is dedicated to the transcribed strand (TS) of actively transcribed genes. In yeast S. cerevisiae, Rad7, Rad16, and Elc1 are specifically required for GGR. TCR is believed to be initiated by RNA polymerase II (Pol II) stalled at a lesion in the TS of a …

Enhancing Healthy Adolescent Development, Registered Nurses' Association Of Ontario

General Submissions: Community and Population-based Materials

The nursing profession has long been considered a leader in the area of health promotion and disease prevention. The goal of this document is to assist nurses working with youth in a variety of practice settings, i.e. schools, public health units, community health centres, adolescent clinics, hospitals, and in family practice. Recommendations are inclusive of adolescent development across diverse contexts (e.g. cultural, socioeconomic, structural, political). This guideline is intended for nurses who are not necessarily experts in the above-mentioned practice areas, and who work in a variety of practice settings across the continuum of care. It is acknowledged that individual …

Embyronic Nicotine Exposure And Its Impact On Spinal Neuron Development In Zebrafish, Latoya Telameca Paul

LSU Doctoral Dissertations

Nicotine, a drug of abuse, has been shown to have deleterious outcomes on nervous system development in vertebrates. Using zebrafish behavior as a diagnostic tool, we aimed to understand the effects of embryonic nicotine exposure on spinal neuron development. We initially quantified nicotine incorporation into zebrafish embryos. We found that only a fraction of the waterborne concentration of nicotine was incorporated into embryos. Also, when embryos were exposed to epibatidine and ABT 418, potent alpha 4/beta 2 nAChRs agonists, the embryos exhibited a robust swim-like behavioral response similar to that of nicotine. We then performed immunohistochemistry utilizing the mAB290 antibody …

Design And Development Of Chiral And Achiral Molecularly Imprinted Stationary Phases, Jason Paul Lejeune

LSU Doctoral Dissertations

Although the cross-linker can comprise over 80% of the polymer composition, improving the nature of the cross-linker in molecularly imprinted polymers has not been studied extensively. The goal of this research is to develop novel cross-linking monomers to either use in the One MoNomer Molecularly Imprinted Polymer system (OMNiMIP) or use in conjunction with other commercially available cross-linkers and functional monomers. Chapter 2 contains research into the understanding of the performance of a new cross-linking monomer (N, O - bismethacryloyl ethanolamine, NOBE) discovered in the Spivak Research Group. The ability of this monomer to outperform traditional two monomer systems in …

The Feminization Of Private Investigation: A Sociological Analysis, Jessica Simpson Pearce

LSU Doctoral Dissertations

This dissertation outlines the occupation of private investigation and the role that females play within that profession. The difficulties women experience in male-oriented occupations remains noteworthy in sociological research today. Progress has been made, yet many barriers still exist for women. These include structural, social, and cultural factors that influence women and/or the jobs that they hold. With the completion of interviews with twenty-six female private investigators, I was able to analyze the existing structural, interactional, and gender barriers which moderate the number of women that work as private investigators. Few studies have examined this occupation and this gap may …

Urate Responsive Marr Homologs, Inoka Chinthana Perera

LSU Doctoral Dissertations

Differential gene expression in response to internal and external stimuli is studied in detail to understand the intricate mechanisms underlying response to various environmental stressors in microorganisms. MarR family transcriptional regulators have been studied for their involvement in such mechanisms. This work elucidates the mechanism of urate-induced attenuation of DNA binding of HucR, a MarR homolog, and extends this mechanism to describe a novel subfamily of MarR homologs responsive to urate, proposing a physiological relevance of utilizing urate as a signaling molecule.

HucR (hypothetical urate regulator) binds to the shared promoter region between uricase and hucR genes. It has high …

Revealing The Role Of Receptor Wsx1: A Double-Edged Sword In Tumor Progession, Denada Dibra

LSU Doctoral Dissertations

Tumor initiation and progression are dependent on both aberrant gene expression in tumor cells and the communication between tumor cells and its micro- and systemic microenvironment. Many tumor suppressor genes and oncogenes have been characterized to suppress or promote tumor growth, but fewer genes in tumors are well-characterized as interacting with immune cells in the host to promote or inhibit tumor growth. The interleukin (IL) 27 receptor WSX1 is expressed in immune cells and induces an IL27-dependent immune response. Opposing this conventional dogma, our initial results reveal a much higher level of WSX1 expression in multiple types of epithelial tumor …

The Care Plan As An Indicator Of Change In Nursing Science Instruction: A Textbook-Based Analysis, Lindsay Bratton-Mullins

LSU Doctoral Dissertations

Sciences are critical in nursing education to aid the nurse in understanding health and disease processes. Accrediting bodies for nursing education have emphasized that educators teach in ways that encourage critical thinking and, therefore, produce safe-practicing, competent nurse graduates. Nursing care plans best reflect nursing education’s central goals. Because of its longevity of use and familiarity, in this study, the nursing care plan was used as a proxy for nursing science’s learning objectives. This research was a study of the nursing care plan as an indicator for change in nursing science education in the United States to determine if change …

Functional Characterization Of A Zinc Finger Protein Aebp2, Hana Kim

LSU Doctoral Dissertations

AEBP2 is a zinc finger protein that has been shown to interact with the mammalian Polycomb Repression Complex 2 (PRC2). I characterized this unknown protein and tested its potential targeting roles for the PRC2. AEBP2 is an evolutionarily well-conserved gene that is found in animals ranging from flying insects to mammals. The transcription of mammalian AEBP2 is driven by two alternative promoters and produces multiple transcripts that give rise to at least two isoforms of the protein. These isoforms show developmental stage-specific expression patterns: the larger adult-specific form (52 kDa) and the smaller embryo-specific form (31 kDa). The AEBP2 protein …