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The Uptake And Distribution Of Diethyltoluenediamine In The Male Sprague Dawley Rat., Michael Charles Babin Jan 1997

The Uptake And Distribution Of Diethyltoluenediamine In The Male Sprague Dawley Rat., Michael Charles Babin

LSU Historical Dissertations and Theses

Diethyltoluenediamine (CAS 68479-98-1) is a ring-ethylated analog of toluenediamine (TDA) and like TDA, consists of the 2,4- and 2,6-diamine isomers. DETDA was developed by Albermarle Corporation as a substitute for TDA in some applications. To determine the uptake and distribution of 2,4- and 2,6-DETDA, 5 groups of 4 adult male Sprague Dawley rats were gavaged at 179 $\mu$mol/kg body weight with ($\sp3$H) -2,4- or ($\sp3$H) -2,6-DETDA. Multiple tissues were collected at 1, 4, 8, 24 and 48 hours. Very high levels of label occurred in the gastrointestinal system and bladder during the first 8 hours while liver and kidney exhibited …

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Reductive Precipitation Of Uranium By Free And Immobilized Cells And Cell Fractions Of Facultative And Anaerobic Bacteria., Boyce Lamont Clark Jan 1997

Reductive Precipitation Of Uranium By Free And Immobilized Cells And Cell Fractions Of Facultative And Anaerobic Bacteria., Boyce Lamont Clark

LSU Historical Dissertations and Theses

This study examines the interaction between two genera of bacteria and the biochemical reduction of uranium. The bacteria studied are the obligate anaerobe, Desulfovibrio desulfuricans, and the facultative aerobe, Escherichia coli. Preliminary experiments established the pH, cell concentration, substrate concentration, and type of substrate that favored reduction of hexavalent uranium in aqueous solutions. Uranium reduction is most complete at pH 7 and 9, with cell concentrations of at least 33.5 mg/ml (dry cell weight). Whole cells of D. desulfuricans were found to reduce uranium in the presence of lactate and hydrogen whereas in E. coli, reduction was achieved only in …

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Flight Muscle Histolysis In The Female House Cricket, Acheta Domesticus., Rush Hoyet Oliver Jan 1997

Flight Muscle Histolysis In The Female House Cricket, Acheta Domesticus., Rush Hoyet Oliver

LSU Historical Dissertations and Theses

Flight muscle histolysis was investigated in the dorsal longitudinal muscles (DLMs) of the cricket. Histolysis in the DLMs was characterized by analysis of total protein content, tissue wet weight, and relative percent muscle shortening. Initial declines of total protein indicated the JH signal initiating histolysis occurred by Day 2. Histolysis was essentially complete by Day 3. Ligation of Day 1 crickets prevented histolysis but this inhibition could be prevented by continual topical treatments with methoprene. Ligation of Day 2 crickets did not prevent histolysis. A requirement for active protein expression was demonstrated by analysis of synthesis block by cycloheximide and …

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Self-Mutilation In A Community Sample Of Adolescents., Elizabeth Eden Lloyd Jan 1997

Self-Mutilation In A Community Sample Of Adolescents., Elizabeth Eden Lloyd

LSU Historical Dissertations and Theses

The purpose of this study was to examine the provisional prevalence rates and characteristics of self-mutilative behavior in a community sample of adolescents. A total of 368 adolescents between the ages of 12 and 19 participated in this investigation. Thirty-nine percent of high school students sampled (n = 143) engaged in self-mutilation within the past year. Commonly endorsed behaviors were biting self, hitting self on purpose, and cutting/carving skin. Self-mutilators were likely to engage in these behaviors to reduce internal tension, as well as to gain attention. Self-mutilators were compared with non-mutilating adolescents (n = 225) on self-report measures of …

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The Development Of Behavioral And Emotional Self-Regulation During The Preschool Period., Maria D. Kalpidou Jan 1997

The Development Of Behavioral And Emotional Self-Regulation During The Preschool Period., Maria D. Kalpidou

LSU Historical Dissertations and Theses

The study investigates age-related changes in behavioral and emotional self-regulation during the preschool period and the relationship between them. Behavioral self-regulation was measured by compliance without external monitors. Emotional self-regulation was measured by the expressed control of emotions and coping strategies. Eighty-eight preschoolers (45 5-year-olds; 43 3-year-olds) participated in a compliance-delay task. They were left alone for 10 min (self-regulated compliance) to sort cutlery in the presence of toys. The demand for emotional self-regulation was manipulated by hiding (low demand) or exposing (high demand) the toys. Children experienced both sessions. All procedures were video-taped. The expressed emotional comfort during the …

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Feedback Linearizing Control Strategies For Chemical Engineering Applications., Michael James Kurtz Jan 1997

Feedback Linearizing Control Strategies For Chemical Engineering Applications., Michael James Kurtz

LSU Historical Dissertations and Theses

Two widely studied control techniques which compensate for process nonlinearities are feedback linearization (FBL) and nonlinear model predictive control (NMPC). Feedback linearization has a low computational requirement but provides no means to explicitly handle constraints which are important in the chemical process industry. Nonlinear model predictive control provides explicit constraint compensation but only at the expense of high computational requirements. Both techniques suffer from the need for full-state feedback and may have high sensitivities to disturbances. The main work of this dissertation is to eliminate some of the disadvantages associated with FBL techniques. The computation time associated with solving a …

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Genetics And Functions Of Herpes Simplex Virus Type 1 (Hsv-1) Glycoprotein K (Gk) In Virus Envelopment And Egress., Sukhanya Jayachandra Jan 1997

Genetics And Functions Of Herpes Simplex Virus Type 1 (Hsv-1) Glycoprotein K (Gk) In Virus Envelopment And Egress., Sukhanya Jayachandra

LSU Historical Dissertations and Theses

HSV-1(KOS)$\Delta$gK, a virus lacking the UL53 gene coding for glycoprotein K(gK) was constructed, characterized and compared to the partially deleted gK-null virus HSV-1(F)-gK$\beta$. $\Delta$gK and F-gK$\beta$ viruses produced microscopic plaques on Vero cells at 48 hours post infection. F-gK$\beta$ plaques at 72 hours post infection contained fused cells (syn), while $\Delta$gK plaques resembled wild-type KOS plaques ($syn\sp+$). $\Delta$gK replicated efficiently in exponentially dividing Vero cells whereas F-gK$\beta$ yields were 10 and 1000-fold lower than $\Delta$gK yields in HEp-2 or log-phase Vero cells, respectively. Electron micrographs of $\Delta$gK-infected Vero cells revealed large numbers of capsids in the nuclei of Vero, but …

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Acute Effects Of Passive Muscle Stretching On The Stretch-Shortening Phenomenon., Andrew Cornwell Jan 1997

Acute Effects Of Passive Muscle Stretching On The Stretch-Shortening Phenomenon., Andrew Cornwell

LSU Historical Dissertations and Theses

Two experiments examined the acute effects of passive muscle stretching on the performance of a skill (vertical jump) which takes advantage of the stretch-shortening phenomenon. Because recent work suggests that passive stretching might impede the mechanisms (elastic and myoelectrical potentiation) thought to be responsible for this phenomenon, it was hypothesized that stretching would decrease the jump height of jumps executed with a preparatory countermovement (CMJ), but not the jump height of those initiated from a static, squatting position (SJ). In the first experiment, subjects performed CMJ and SJ jumps under two different conditions: after passively stretching the knee and hip …

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Cloning, Sequencing And Regulation Of The Rhodobacter Capsulatus Hemh Gene., Ekaterina Vladislavova Kanazireva Jan 1997

Cloning, Sequencing And Regulation Of The Rhodobacter Capsulatus Hemh Gene., Ekaterina Vladislavova Kanazireva

LSU Historical Dissertations and Theses

Rhodobacter capsulatus, a purple non-sulfur photosynthetic bacterium, synthesizes four tetrapyrrole end products: heme, bacteriochlorophyll, siroheme and vitamin B$\sb{12}$ via the common tetrapyrrole biosynthetic pathway. The biosynthesis of tetrapyrroles in R. capsulatus is a complex and precisely controlled process which has been under extensive investigation. In order to study the regulation of tetrapyrrole biosynthesis, the R. capsulatus hemH gene was cloned by complementation of an E. coli $\Delta hemH$ mutant and sequenced. The enzyme ferrochelatase, encoded by the hemH gene, catalyzes the insertion of ferrous iron into protoporphyrin IX, thus producing heme. The consensus ferrochelatase signature sequence was found in the …

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The Influence Of Violence Upon Academic Achievement Among African American First Time College Students., Diana F. Kelly Jan 1997

The Influence Of Violence Upon Academic Achievement Among African American First Time College Students., Diana F. Kelly

LSU Historical Dissertations and Theses

This study examined the relationship between early exposure to violence--both personal and community--and the later academic achievement of African American first time college students. The study incorporated several variables that were thought to impinge upon the academic achievement process. Specifically, those variables were divided into several groups: background factors (socioeconomic status, high school academic record, personal and community violence exposure), student characteristics (locus of control, educational aspirations and expectations), and university characteristics (campus safety, academic and social integration). Student achievement was measured by students' expected grade point average, as indicated on a student questionnaire. University administrators, professors, and researchers who …

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Academic Discipline, Mentoring, And The Career Commitment Of Women Faculty., Gloria Tara Nye Jan 1997

Academic Discipline, Mentoring, And The Career Commitment Of Women Faculty., Gloria Tara Nye

LSU Historical Dissertations and Theses

Women continue to be underrepresented as faculty at U.S. universities, especially in the physical sciences and engineering. The belief that only women can adequately serve as role models and mentors for other women may be a roadblock to progress for women in disciplines where they are underrepresented. This study of women faculty investigates how female career commitment is influenced by academic discipline and mentoring. The survey responses of sixty-six tenure-track women faculty were used to obtain data for both science or engineering and non-science or engineering academic disciplines at three public Ph.D. granting research universities. The women faculty in science …

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Structure-Activity Relationships Of Nitroarenes: Mutagenicity, Oxygen Consumption, Toxicity, And Xenobiotic Radical Production., Caroline Ann Metosh-Dickey Jan 1997

Structure-Activity Relationships Of Nitroarenes: Mutagenicity, Oxygen Consumption, Toxicity, And Xenobiotic Radical Production., Caroline Ann Metosh-Dickey

LSU Historical Dissertations and Theses

The nitroreduction of 4NQO and five structural analogs were studied with respect to radical production and mutagenicity. In the umu assay, 4NQO was the most mutagenic analog. Addition of microsomal and cytosolic protein from induced and uninduced rat liver samples decreased 4NQO mutagenicity in the standard strain (Salmonella typhimurium TA 1535/psk1002) 4NQO mutagenicity was also found to be decreased in the nitroreductase-deficient strain (Salmonella typhimurium TA1535NR/psk1002). In several strains of the Protox$\rm\sp{TM}$ assay 4NQO yielded the highest induction rate as compared to other compounds tested. In the presence of ascorbate 4NQO cytotoxicity, but not mutagenicity, was substantially enhanced. Oxygen consumption …

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Nature, Culture And Big Old Trees: Human Relationships With Ceiba (Ceiba Pentandra) And Live Oak (Quercus Virginiana) In The Landscapes Of Guatemala And Louisiana., Katharine Anderson Jan 1997

Nature, Culture And Big Old Trees: Human Relationships With Ceiba (Ceiba Pentandra) And Live Oak (Quercus Virginiana) In The Landscapes Of Guatemala And Louisiana., Katharine Anderson

LSU Historical Dissertations and Theses

The ceiba in Guatemala and the live oak in Louisiana are examples of two trees that attain great size and age within the cultural landscape. Humans have adopted both as symbolic trees; they protect, encourage and even plant them. As the trees age, they become historic landmarks, are indicators of important places, and give character to the landscape. Although each tree is native within portions of each study area, both have taken advantage of human disturbance to expand beyond their original habitats. In addition, they have been moved deliberately by humans to new areas well beyond their geographical limits. Other …

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Macrofaunal Community Structure In The Introduced And Native Submerged Macrophyte Beds Of The Lake Pontchartrain Estuary., Kenneth Charles Duffy Jan 1997

Macrofaunal Community Structure In The Introduced And Native Submerged Macrophyte Beds Of The Lake Pontchartrain Estuary., Kenneth Charles Duffy

LSU Historical Dissertations and Theses

Introductions of exotic aquatic plants raise concerns for the health of assemblages of native species. The possible influence of the establishment of the exotic Eurasian watermilfoil Myriophyllum spicatum on fish and invertebrate assemblages in the Lake Pontchartrain estuary was examined with a microhabitat approach. Fish and invertebrate assemblage structure and population responses were compared among macrophyte species and unvegetated areas. Native macrophytes included wild celery Vallisneria americana and wigeongrass Ruppia maritima. Additionally, the relationships of the common submerged macrophytes to environmental and temporal variables were analyzed. A total of 517 samples, collected with a modified Wegener ring, included 3,564 fishes …

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Development And In Vivo Evaluation Of A Pura Mutant Strain Of The Channel Catfish Pathogen Edwardsiella Ictaluri., Mark Lee Lawrence Jan 1997

Development And In Vivo Evaluation Of A Pura Mutant Strain Of The Channel Catfish Pathogen Edwardsiella Ictaluri., Mark Lee Lawrence

LSU Historical Dissertations and Theses

Edwardsiella ictaluri is the causative agent of enteric septicemia of catfish (ESC), which is the most serious disease affecting the channel catfish industry. Killed vaccines have been inconsistent in providing protection against ESC, and no live attenuated vaccines have been described. The purpose of this study was to develop a nutritionally attenuated mutant strain of E. ictaluri and evaluate its virulence and vaccine efficacy. An E. ictaluri genomic library was constructed, and a clone containing the purA gene was isolated and sequenced. The E. ictaluri purA gene was found to have several features in common with the E. coli purA …

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Genotype By Environment Interaction For Ear Moisture Loss Rate In Corn., Robert T. Magari Jan 1997

Genotype By Environment Interaction For Ear Moisture Loss Rate In Corn., Robert T. Magari

LSU Historical Dissertations and Theses

Corn (Zea mays L.) hybrids with rapid ear moisture loss rate (EMLR) are needed to reduce post-harvest production costs relative to artificial grain drying. Previous investigations indicated that genetic variation for grain dry-down rate existed; however, genotype by environment interaction (GEI) for this trait has not been specifically investigated. The objectives of this study were: (1) to evaluate EMLR and stability of selected commercial corn hybrids in different environments, (2) to determine approximate optimum numbers of plants per plot, replications, and environments for evaluating EMLR, and (3) to assess the contribution of known environmental factors to GEI for EMLR. Experiments …

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Coastal Management Regarding Beach And Dune Protection: An Exploratory Analysis., Melissa Lee Gordon Jan 1997

Coastal Management Regarding Beach And Dune Protection: An Exploratory Analysis., Melissa Lee Gordon

LSU Historical Dissertations and Theses

The Congressional declaration of national coastal policy in Section 303 of the Federal Coastal Zone Management Act (CZMA) of 1972 charges the coastal states to meet the objective of coastal resource protection. At this time, when the appropriate mix of authority between federal and state governments concerning environmental regulations is in debate; it is important to determine whether the inter-governmental partnership created by CZMA is effective in protecting coastal resources. This research is an exploratory analysis of coastal management regarding beach and dune protection within the twenty-four coastal states. The dissertation objectives are as follows: (1) determine the level of …

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Synthesis Of Monodisperse Poly(Gamma-Benzyl-Alpha,L-Glutamate) Oligomers And Their Star-Shaped Derivatives., Xiaolan Wang Jan 1997

Synthesis Of Monodisperse Poly(Gamma-Benzyl-Alpha,L-Glutamate) Oligomers And Their Star-Shaped Derivatives., Xiaolan Wang

LSU Historical Dissertations and Theses

Poly($\gamma$-benzyl-$\alpha$,L-glutamate), PBLG, is a widely studied example of polypeptides. The preparation of monodisperse samples of PBLG and PBLG oligomer is difficult to achieve. In this work we probe the possibility of preparation of PBLG oligomers by polymerization of L-glutamic acid N-carboxyanhydride (NCA) with different initiators such as primary amine, sterically hindered secondary amine, tertiary amine, and strong base. Information regarding molecular weight distribution of these oligomers was obtained by applying MALDI-TOF mass spectrometry and reversed phase HPLC. While some researchers reported that application of primary amine initiators or polar solvents such as DMF could improve the molecular weight distributions of …

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Visualizing Autobiography: Intersections Of Gender, Representation, Curriculum Theory., Anne Elizabeth Pautz Jan 1997

Visualizing Autobiography: Intersections Of Gender, Representation, Curriculum Theory., Anne Elizabeth Pautz

LSU Historical Dissertations and Theses

Defined by customs of femininity, women who transcend those definitions find it difficult to represent themselves in a comprehensible manner. The contradictions between the actual activities of life and the demands of femininity require woman to adopt unique approaches to self-representation in order to be accepted. Tied to the biological functions of their bodies through images in the media and social institutions, as well as their internalized images, women often find trying to represent themselves beyond or against their body problematic. The female body is presented as controller of destiny, both through beauty and motherhood requirements. Women often create representations …

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Causes Of Vegetation Dieback And Subsequent Wetland Loss In Two Louisiana Coastal Marshes., Eric Courtney Webb Jan 1997

Causes Of Vegetation Dieback And Subsequent Wetland Loss In Two Louisiana Coastal Marshes., Eric Courtney Webb

LSU Historical Dissertations and Theses

Vegetation dieback is an important component of the wetland loss process in coastal Louisiana. To determine the factors causing vegetation dieback in a Louisiana salt marsh and oligohaline marsh, field monitoring and manipulative field experiments were conducted in both marsh types. In the salt marsh, a three-year field study was conducted in which biotic and edaphic characteristics were measured and the effect of elevation on four salt marsh plant species was tested in a manipulative field experiment. In the oligohaline marsh, a two-year field study was conducted which evaluated the relationship between biotic and edaphic characteristics. Additionally, the effects of …

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Caprine Sperm Cells As Vectors For Gene Transfer., Yongxin Sun Jan 1997

Caprine Sperm Cells As Vectors For Gene Transfer., Yongxin Sun

LSU Historical Dissertations and Theses

Goat sperm cells were used as a model to evaluate sperm-mediated gene transfer. Fresh and frozen-thawed goat sperm cells were co-incubated with radio-labelled foreign DNA. After 10 extensive washings, the compacted sperm retained foreign DNA. Confocal microscopy confirmed that the position on the sperm cell responsible for binding of foreign DNA was located in both the anterior and the posterior heads of caprine sperm cells. Furthermore, confocal longitudinal sections of the sperm cells showed that foreign DNA had penetrated into goat sperm nuclei. In this study, 37% of the fresh goat sperm and 33% of the frozen-thawed goat sperm cells …

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Acid Solubilization Of Fish Protein For Production Of Protein Hydrolysate., Ercument Ozer Jan 1997

Acid Solubilization Of Fish Protein For Production Of Protein Hydrolysate., Ercument Ozer

LSU Historical Dissertations and Theses

The mechanism of fish protein solubilization by acid hydrolysis at elevated temperatures was investigated. Rate expressions for the solubilization were determined using pilot scale data with two different rate determination methods. A postulated mechanism was verified and estimated rates were evaluated on five independent verification experiments. A functional relationship between nonprotein byproduct concentration and whiteness of fish protein hydrolysate (FPH) was developed. Initial and set-point operating variables were calculated to produce FPH with acceptable color characteristics for food use. A batch reactor was used for duplicate hydrolysis trials conducted at three acid and three temperature levels for four hours. Samples …

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Late Quaternary Foraminifera From Lower Bathyal And Abyssal Sediments, Gulf Of Mexico: A Record Of Paleoceanographic Change., Megan H. Jones Jan 1997

Late Quaternary Foraminifera From Lower Bathyal And Abyssal Sediments, Gulf Of Mexico: A Record Of Paleoceanographic Change., Megan H. Jones

LSU Historical Dissertations and Theses

Striking late Quaternary surface- and deep-water oceanographic changes and a link to North Atlantic thermohaline circulation are identified by analyses of high-resolution, benthic and planktic foraminiferal census data from the lower bathyal and abyssal Gulf of Mexico (GOM). The recognized environmental, watermass, preservation, and productivity signals reveal a detailed paleoenvironmental and paleoceanographic history. A paleoceanographic model developed for surface and deep waters of the abyssal Gulf describes a four-stage sequence of oceanographic changes from the Last Glacial Maximum (LGM) to the present. Compared to present-day surface waters, those of LGM were nutrient-enriched and had reduced productivity. The influx of glacial …

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Negotiating Literacy Instruction: Pedagogical Perceptions Of Secondary Preservice Teachers., Julie Hill Lester Jan 1997

Negotiating Literacy Instruction: Pedagogical Perceptions Of Secondary Preservice Teachers., Julie Hill Lester

LSU Historical Dissertations and Theses

Secondary teachers face the challenge of planning instructional activities that combine their own subject knowledge with information from textbooks and other forms of text to help students learn content material. This study explores preservice teachers' perceptions regarding literacy instruction within the context of teaching and learning content material. The participants are senior secondary education students enrolled in a content area literacy course at a regional university in the southeast. Case studies are constructed for six preservice teachers representing different content areas. Qualitative data collection procedures included a questionnaire, guided journal entries, literacy autobiography, and personal interviews. Cross-case analysis was employed. …

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Preparation Of Strained Nitrogen Heterocycles For Spin Trapping Applications., Anna Patrice Shanklin Jan 1997

Preparation Of Strained Nitrogen Heterocycles For Spin Trapping Applications., Anna Patrice Shanklin

LSU Historical Dissertations and Theses

This work discusses the synthesis of bicyclic nitrogen heteorocycles with the emphasis placed on the design and evaluation of a bicyclic nitrone for spin trapping applications. Camphorolactams, 1,7,7-trimethyl-2-aza-bicyclo(2.2.1) heptan-3-one and 1,7,7-trimethyl-3-azabicyclo (2.2.1) heptan-2-one were prepared from camphoric anhydride under Curtius conditions with sodium azide and dimethylformamide. 2-azabicyclo(2.2.1) heptan-3-one was also prepared under Curtius conditions from cis-1,3-cyclopentane-dicarboxylic acid anhydride. N-benzyl-2-azabicyclo (2.2.1) -heptane and N-benzyl-2-azabicyclo (2.2.2) octane were prepared from their aliphatic amine derivatives under Hofmann-Loeffler conditions in low yields. 1,3,3-trimethyl-6-azabicyclo (3.2.1) octane, N-oxide was prepared from its parent amine under sodium tungstate catalyzed oxidation with hydrogen peroxide. The bicyclic nitrone was …

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Relative Rates Of Molecular Evolution In Rodents And Their Symbionts., Theresa Ann Spradling Jan 1997

Relative Rates Of Molecular Evolution In Rodents And Their Symbionts., Theresa Ann Spradling

LSU Historical Dissertations and Theses

The focus of this dissertation is the relative tempo of molecular evolution among organisms of varying levels of relatedness. Because this is a rapidly expanding area of research, Chapter 1 is devoted to a review of the current state of knowledge on rates of molecular evolution. In Chapter 2, I present an analysis of relative rates of evolution among several distantly related rodents. The heterogeneity in rate of evolution of the cytochrome b gene observed here cannot be explained by metabolic rate, body size, generation time, or nucleotide-generation time. Likewise, there is no evidence that these differences in rate of …

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Syntheses, Separations, And Applications Of Water-Soluble Chiral Calixarenes., Yuling Zhang Jan 1997

Syntheses, Separations, And Applications Of Water-Soluble Chiral Calixarenes., Yuling Zhang

LSU Historical Dissertations and Theses

This dissertation focuses on the study of water-soluble calixarene derivatives as receptors for fluorescence probes and as chiral selectors. The synthesis of sulfonated calixarenes was first pursued and a method for the separation of sulfonated calixarenes (4), (6), (8) and the 4-hydroxylbenzene sulfonate monomer by capillary zone electrophoresis with direct UV absorbance detection is described. Fluorescence and absorption studies of water-soluble sulfonated calix(6)arene (SCX6) are reported. A red shift in the absorption spectrum and a change in the fluorescence spectrum of the calixarenes are observed upon an increase in pH from 2.0 to 13.0. The spectroscopic changes are attributed to …

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A Theory Of Cortical Neural Processing., David Timothy Young Jan 1997

A Theory Of Cortical Neural Processing., David Timothy Young

LSU Historical Dissertations and Theses

This dissertation puts forth an original theory of cortical neural processing that is unique in its view of the interplay of chaotic and stable oscillatory neurodynamics and is meant to stimulate new ideas in artificial neural network modeling. Our theory is the first to suggest two new purposes for chaotic neurodynamics: (i) as a natural means of representing the uncertainty in the outcome of performed tasks, such as memory retrieval or classification, and (ii) as an automatic way of producing an economic representation of distributed information. We developed new models, to better understand how the cerebral cortex processes information, which …

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Cloning And Expression Of Capsid Proteins Of Hepatitis A Virus In Escherichia Coli., Lingaiah Chandrashekar Jan 1997

Cloning And Expression Of Capsid Proteins Of Hepatitis A Virus In Escherichia Coli., Lingaiah Chandrashekar

LSU Historical Dissertations and Theses

Hepatitis A virus (HAV), the causative agent of food and water borne acute hepatitis worldwide, is very difficult and expensive to propagate in tissue culture. Large scale production of HAV proteins in E. coli by recombinant DNA techniques would be invaluable for antisera production, biochemical analyses and in developing sensitive diagnostic tests. Therefore, PCR amplified DNA fragments encoding the HAV capsid proteins were cloned individually into prokaryotic expression vectors for production of either recombinant fusion or non-fusion proteins. Cloning and expression of HAV capsid genes, which induced toxic effects in certain host E. coli, was tolerated better by protease-deficient host …

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The Synthesis Of Novel Phosphine-Modified Ligands For Use In Bimetallic Hydroformylation., Howard Frederick Koch Iii Jan 1997

The Synthesis Of Novel Phosphine-Modified Ligands For Use In Bimetallic Hydroformylation., Howard Frederick Koch Iii

LSU Historical Dissertations and Theses

The tetraphosphine ligand, Et$\sb2$P(CH$\sb2)\sb2$P(Ph)CH$\sb2$P(Ph)(CH$\sb2)\sb2$PEt$\sb2 ,$ et,ph-P4, was designed to be a binucleating ligand for use in bimetallic hydroformylation catalysis. This ligand can be tailored for both electronic and steric factors at the internal and external phosphorus atoms. It is hoped that through careful tuning of this ligand, the rate and selectivity of our bimetallic catalyst can be optimized for various substrates. Modification of the original ligand may also lead us to a better understanding of the mechanism involved in the catalytic cycle. My goal has been to replace the phenyl substituents on the internal phosphorus atoms with various alkyl groups. …

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