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Honduras' Transisthmian Corridor: An Historical Geography Of Roadbuilding In Colonial Central America., Scott Arlen Brady Jan 1996

Honduras' Transisthmian Corridor: An Historical Geography Of Roadbuilding In Colonial Central America., Scott Arlen Brady

LSU Historical Dissertations and Theses

Historical route geographers consider the factors that influenced past roadbuilding, and the changes that result from roadbuilding. The earliest Spanish colonial officials in Central America initiated roadbuilding projects that were sensitive to physical and cultural factors. Officials had to consider the region's aboriginal routes, Spain's trade flows, the isthmus' topography, and the region's population distribution. The roads the Spaniards opened four centuries ago guided early settlement. In some cases, these early roads persist in the region's route network. During the 16th-century Spaniards sought to establish transisthmian roadways that would link Spain's Atlantic and Pacific maritime networks. Partial fluvial routes across …

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Cloning, Sequencing And Regulation Of The Rhodobacter Capsulatusheme Gene., Georgia Ineichen Jan 1996

Cloning, Sequencing And Regulation Of The Rhodobacter Capsulatusheme Gene., Georgia Ineichen

LSU Historical Dissertations and Theses

In Rhodobacter capsulatus, a purple nonsulfur bacterium, the tetrapyrrole pathway yields four end products: siroheme, vitamin B12, heme and bacteriochlorophyll. Growth of R. capsulatus under low oxygen tension increases carbon flow through the tetrapyrrole pathway up to 100 fold. The mechanism(s) for this regulation is currently unknown. One regulatory mechanism could be transcriptional control of one or more of the genes in the common portion of the tetrapyrrole pathway. The fifth gene in the pathway, hemE, has been cloned by complementation of an Escherichia coli hemE::miniTn10 mutant. Sequence data of hemE revealed the presence of an upstream palindrome that is …

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Importance Of A Siderophore In The Pathogenesis And Virulence Of Photobacterium Damsela Subsp. Piscicida In Hybrid Striped Bass (Morone Saxatili X Morone Chrysops)., John Phillip Hawke Jan 1996

Importance Of A Siderophore In The Pathogenesis And Virulence Of Photobacterium Damsela Subsp. Piscicida In Hybrid Striped Bass (Morone Saxatili X Morone Chrysops)., John Phillip Hawke

LSU Historical Dissertations and Theses

Photobacterium damsela subsp. piscicida, formerly Pasteurella piscicida, is an important new pathogen of hybrid striped bass cultured in brackish water on Louisiana mariculture farms. Louisiana isolates compared with strains of P. damsela subsp. piscicida from Greece, Japan, Israel and Chesapeake Bay, USA and were found to be identical in biochemical phenotype and enzymic activity. Small plasmids of 8 and 5 kb were unique to Louisiana strains. Sequential daily bacteriology and histopathology on hybrid striped bass experimentally infected by immersion revealed that following high doses (13,000 CFU/ml) the gills and spleen are colonized first as early as 24 hours PI, followed …

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The "Sacred Harp" In The Urban North: 1970-1995., Mark David Johnson Jan 1996

The "Sacred Harp" In The Urban North: 1970-1995., Mark David Johnson

LSU Historical Dissertations and Theses

In 1994 the Sacred Harp, a southern, shape-note tunebook, entered its 150th year of continuous use. First compiled in 1844 by B. F. White and E. J. King, and updated numerous times, The Sacred Harp books in the "Denson" tradition, including The Sacred Harp: 1991 Edition, are today the most popular and widely used twentieth-century revisions of any nineteenth-century tunebook. Sacred Harp singing has been a largely rural, Southern tradition and in the years between 1844 and the early 1970s several hundred separate singings were founded, many of which continue to be active. In the early 1990s the Sacred Harp …

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Experimental Lymphatic Filariasis In Gerbils (Meriones Unguiculatus): Molecular Cloning And Expression Of Gerbil Cytokines And Measurement Of Cytokine Gene Expression During A Primary Infection Of Brugia Pahangi., Zhiming Mai Jan 1996

Experimental Lymphatic Filariasis In Gerbils (Meriones Unguiculatus): Molecular Cloning And Expression Of Gerbil Cytokines And Measurement Of Cytokine Gene Expression During A Primary Infection Of Brugia Pahangi., Zhiming Mai

LSU Historical Dissertations and Theses

Cytokines play an important role in regulation of T cell responses. Two T helper cell subsets have been identified in some species and are defined by their cytokine secretion profiles. Th1 cells produce IL-2 and IFN-$\gamma,$ whereas Th2 cells express IL-4, IL-5, and IL-10. Precursor T cells that express a mixture of these cytokines are considered Th0 cells. It is hypothesized that primary infections of Brugia pahangi in gerbils induce an initial Th0 or Th1 like response which with time becomes a Th2 like response. To test this dynamic parasitism induced shift in cytokine profile, it is necessary to measure …

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Inflammatory Responses Of The Jird To Brugia Pahangi: Parasite Stage Specificity And Role Of The Macrophage., Carmen Nasarre Jan 1996

Inflammatory Responses Of The Jird To Brugia Pahangi: Parasite Stage Specificity And Role Of The Macrophage., Carmen Nasarre

LSU Historical Dissertations and Theses

The host systemic and peritoneal inflammatory responses against different stages of Brugia pahangi were compared in intraperitoneally infected-jirds. Systemic inflammatory responses were assessed by measuring the pulmonary granulomatous response to B. pahangi antigen-coated beads (PGRN). Peritoneal inflammation was characterized by enumeration of different cell types in peritoneal exudates following infection. Further, the toxoplasmacidal activity and TNF-$\alpha$-like production of peritoneal macrophages were also characterized. Infection with L3, L4, male worms, female worms, microfilariae (MF) or dead adult worms induced a rapid PGRN. This response decreased to levels of controls in jirds inoculated with living parasites at the chronic time period, indicating …

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Effect Of Diet On Respiratory Fuel Mixture, Insulin Sensitivity, And Autonomic Nervous System Function., Heli J. Roy Jan 1996

Effect Of Diet On Respiratory Fuel Mixture, Insulin Sensitivity, And Autonomic Nervous System Function., Heli J. Roy

LSU Historical Dissertations and Theses

Introduction. A high amount of dietary fat has been shown to have a negative effect on metabolism, causing insulin resistance, weight gain, and other metabolic alterations. Several studies have found a direct link between lack of activity and obesity. Purpose. The purpose of this study was to see if a diet had an effects on insulin sensitivity, autonomic nervous system function, and substrate utilization as predicted by Flatt, in healthy young men. Subjects. The subjects studied were 6 nonathletes (NA), 6 aerobically trained (AT), and 5 weight trained (WT) men. Their body mass index (BMI) was 22.1 $\pm$ 2.92 kg/m$\sp2$ …

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Image Analysis Quantification Of Decondensation Of Bovine Spermatozoa And Pcr Amplification Of A Y Chromosome Specific Sequence., Hilde Christina Steinholt Jan 1996

Image Analysis Quantification Of Decondensation Of Bovine Spermatozoa And Pcr Amplification Of A Y Chromosome Specific Sequence., Hilde Christina Steinholt

LSU Historical Dissertations and Theses

The first objective of this research was to develop a decondensation treatment for bovine spermatozoal DNA that worked consistently across bulls and breeds. The second objective was to use the decondensed DNA for polymerase chain reaction analysis of levels of Y-bearing spermatozoa in different ejaculates and in sex sorted spermatozoa. Decondensation of spermatozoa with dithiothreitol and potassium hydroxide was compatible with in vitro amplification and did not inhibit amplification. The polymerase chain reaction and image analysis were used to differentiate between proportions of Y spermatozoa by measuring fluorescent intensities of electrophoresed, polymerase chain reaction-amplified DNA. There were differences in intensities …

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The Amazon Myth In Western Literature., Bruce Robert Magee Jan 1996

The Amazon Myth In Western Literature., Bruce Robert Magee

LSU Historical Dissertations and Theses

This dissertation identifies and evaluates the ways in which the Amazon myth has functioned. The Amazon myth functions within broader discourses about the Orient, Africa, and women. It has implications for the ways we define "self" and "other." Because they are often represented as a threat to the border from long ago and/or far away, Amazons can serve both as an excuse for fortifying the center against the margin, and as a way of projecting fantasies into the void. The Amazon myth has incited men to action as they have searched for adventure and Amazons abroad. Intended in part as …

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The Use Of Communication Facilitators With Severely Brain Injured Non-Responsive Adults., Alisa Judith Mendoza Jan 1996

The Use Of Communication Facilitators With Severely Brain Injured Non-Responsive Adults., Alisa Judith Mendoza

LSU Historical Dissertations and Theses

Slow-to-Recover (STR) individuals are a subset of the neurologically impaired population who remain non-responsive for extended periods of time before beginning to demonstrate improvement in cognitive, communicative, or motor function. This investigation focuses on the development and implementation of a facilitator-based intervention program carried out with an STR brain injured adult residing in a long-term care facility. The model involved: (1) sensory stimulation techniques to increase responses to external stimuli, (2) augmentative techniques which enabled the subject to control his immediate environment and, (3) training of qualified residents within the facility to act as communication facilitators. Ethnographic procedures were employed …

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An Integrated Network Architecture For A High Speed Distributed Multimedia System., Nitin Subrao Naik Jan 1996

An Integrated Network Architecture For A High Speed Distributed Multimedia System., Nitin Subrao Naik

LSU Historical Dissertations and Theses

Computer communication demands for higher bandwidth and smaller delays are increasing rapidly as the march into the twenty-first century gains momentum. These demands are generated by visualization applications which model complex real time phenomena in visual form, electronic document imaging and manipulation, concurrent engineering, on-line databases and multimedia applications which integrate audio, video and data. The convergence of the computer and video worlds is leading to the emergence of a distributed multimedia environment. This research investigates an integrated approach in the design of a high speed computer-video local area network for a distributed multimedia environment. The initial step in providing …

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The Association Between Chronic Aerobic Activity And Heart Rate Variability In Patients With Coronary Artery Disease., Robert Howard Wood Jan 1996

The Association Between Chronic Aerobic Activity And Heart Rate Variability In Patients With Coronary Artery Disease., Robert Howard Wood

LSU Historical Dissertations and Theses

Poor heart rate variability (HRV) among patients with coronary artery disease (CAD) is predictive of future incidence of sudden arrhythmic and all-cause death. Furthermore, mental stress appears to further depress HRV in these patients. Chronic aerobic activity level appears to be positively related to HRV among the general population; however, the extent to which this relationship exists among patients with CAD is not clear. Therefore, this study investigated the association between level of chronic aerobic activity and HRV among CAD patients during conditions of paced respiratory control and during the Stroop Color-Word Conflict Test (CWCT). CAD patients were assigned to …

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Microsatellite-Based Paternity Analysis In Hexaploid Sweetpotato (Ipomoea Batatas (L.) Lam.)., Mario Ignacio Buteler Jan 1996

Microsatellite-Based Paternity Analysis In Hexaploid Sweetpotato (Ipomoea Batatas (L.) Lam.)., Mario Ignacio Buteler

LSU Historical Dissertations and Theses

The use of genetic markers for paternity identification was investigated in hexaploid sweetpotato. Traditional sweetpotato breeding relies on the open pollination of numerous parents and the visual selection of progeny. Previous empirical and theoretical evidence shows this type of breeding system is extremely inefficient. Typically, only a few of these maternal parents routinely produce superior progeny. A similar scenario exists for the paternal parent. Identifying specific parental combinations which produce superior progeny would improve breeding efficiency, hence the need to identify paternity in superior progeny. A computer simulation study established the minimum number of alleles and loci required for paternity …

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Movements, Habitat Use, And Survival Of Female Northern Pintails In Southwestern Louisiana., Robert Ripley Cox Jr Jan 1996

Movements, Habitat Use, And Survival Of Female Northern Pintails In Southwestern Louisiana., Robert Ripley Cox Jr

LSU Historical Dissertations and Theses

I developed portable platforms for setting rocket nets in open-water habitats, and used them to capture 1116 waterfowl of 7 species during winters 1991-92 and 1992-93 in southwestern Louisiana. Distance and duration of evening flights of female northern pintails (Anas acuta; hereafter pintails) from Lacassine National Wildlife Refuge increased with date within wintering period, and generally were greater than previously reported estimates for wintering waterfowl. I found that diurnal use of refuges by females increased during hunting seasons, contradicting Tamisier's hypothesis that use of refuges by pintails in southwestern Louisiana is not influenced by hunting. Female pintails extensively used privately …

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Cytogenetic And Molecular Analysis Of The Channel Catfish (Ictalurus Punctatus) Genome., Quiyang Zhang Jan 1996

Cytogenetic And Molecular Analysis Of The Channel Catfish (Ictalurus Punctatus) Genome., Quiyang Zhang

LSU Historical Dissertations and Theses

This research presents studies on cytogenetics and molecular genetics of channel catfish (Ictalurus punctatus), the most important fish species cultured in the United States. The goals of this project were to analyze the genome of the channel catfish and to develop a direct method of mapping single-locus genes. A series of techniques were developed to facilitate these studies, including culture of fibroblast cells, preparation of chromosomes from catfish of different ages, staining for nucleolus organizer regions (NOR) and heterochromatin (C-banding), restriction enzyme banding, replication R-banding, simultaneous detection of sister-chromatid exchange (SCE) and C-banding, fluorescent in-situ hybridization (FISH) and indirect and …

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Molecular Systematics Of Red Algae., Jeffrey Craig Bailey Jan 1996

Molecular Systematics Of Red Algae., Jeffrey Craig Bailey

LSU Historical Dissertations and Theses

Phylogenetic analyses of nucleotide sequences for the nuclear-encoded small subunit ribosomal RNA (SSU) gene were used to test current hypotheses of relationships within the Corallinales and among the florideophycidaean orders of red algae. Analyses of SSU gene sequences indicate that the order Corallinales includes four major lineages. The Sporolithaceae is resolved as the earliest-diverging lineage within the order and forms the sister group to a monophyletic Corallinaceae. The molecular data also support the monophyly of the subfamilies Melobesioideae and Corallinoideae. The latter subfamily is inferred as sister to a fourth lineage including non-geniculate and geniculate species classified in the subfamilies …

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Immobilization Of P. Digitatum And Bioconversion Of Limonene To Alpha-Terpineol., Qiang Tan Jan 1996

Immobilization Of P. Digitatum And Bioconversion Of Limonene To Alpha-Terpineol., Qiang Tan

LSU Historical Dissertations and Theses

The parameters of bioconversion of limonene to $\alpha$-terpineol by Penicillium digitatum were determined. This bioconversion was carried out stereo-specifically and selectively by this fungus. (R)-(+)-limonene was selectively converted to (R)-(+)-$\alpha$-terpineol by mycelia of this fungus during early growth phase. Immobilization of the fungal mycelia for use in continuous production of this product was possible. Aeration was critical to this bioconversion. The optimum aeration was about 1.6 mg/L for growing cells and immobilized cells. Substrate inhibition of the bioconversion was not observed when the substrate concentration was below 4% (v/v). End product inhibition was observed. The $\rm Ki\sb{app}$ was 12.08 mM. …

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Reduction And Management Of Vibrio Vulnificus In Gulf Coast Oyster (Crassostrea Virginica)., Yu-Pin Chen Jan 1996

Reduction And Management Of Vibrio Vulnificus In Gulf Coast Oyster (Crassostrea Virginica)., Yu-Pin Chen

LSU Historical Dissertations and Theses

The AmeriPure Process (AmeriPure Oyster Company, New Orleans, Louisiana), which is a mild heat treatment for a specific time period, proved effective in eliminating Vibrio vulnificus from the Gulf Coast oysters (Crassostrea virginica), thus reducing the risk of possible V. vulnificus infections. The treatment was effective in the reduction of V. vulnificus in both $1.5\times10\sp5$ MPN/g (high artificially contaminated level) and $2.4\times10\sp3$ MPN/g (low artificially contaminated level) to undetectable level (MPN $<$ 3/g). The mild heat treatment also reduced naturally occurring V. vulnificus $(8.9\pm3.7\times10\sp4$ MPN/g) present in shellstock oysters harvested in warmer months to undetectable levels. The D value for V. vulnificus present in shellstock oyster averaged 45.6 $\pm$ 3.3 seconds at the AmeriPure Process temperature. Mild heat treatment can also control aerobic plate count numbers during refrigerated storage (0-2$\sp\circ$C) and extend the shelf-life of raw oysters for at least 7 days over unprocessed samples. Mild heat treated oysters need to be refrigerated (${<}4\sp\circ$C) to ensure the safety and quality, as well as shelf-life. Oysters treated according to the AmeriPure Process when exposed to an average room temperature of 27$\sp\circ$C were found unacceptable after 24 hours due to the high number of aerobic plate count (10$\sp7$ CFU/g) and were considered not safe to eat. Although there was a slight lightening in color, sensory panels, composed of both traditional raw oyster consumers and infrequent consumers, found the treated product to be comparable in flavor, texture and smell to untreated oysters. According to the result of sensory evaluation, the good oyster flavor of treated samples increased and the off-flavor and off-odor of the treated oysters were significantly lower than the control samples after 7 days of storage on ice. Possible temperature variations, which could occur during the transportation and storage were studied in a temperature abuse study. The result showed that no Vibrio vulnificus was recovered and no significant microbiological quality change was observed after 10 hours of exposure to the room temperature of $22\pm2\sp\circ$C.

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Synthesis Of Novel Amino Acids With Incorporation Into Peptides And Synthesis Of Peptides With Novel Aggregation States., Scott Michael Cowell Jan 1996

Synthesis Of Novel Amino Acids With Incorporation Into Peptides And Synthesis Of Peptides With Novel Aggregation States., Scott Michael Cowell

LSU Historical Dissertations and Theses

Peptides exhibit properties based on the amino acids present in the peptide and structure the peptide assumes in its environment. For example, peptides have been shown to be antimicrobial when they are amphipathic and in an $\alpha$-helical shape. The mechanism for this antimicrobial activity is subject to dispute. One theory states that the peptides work by forming a "pore" through the cell membrane which causes a depolarization of the membrane and the cell lysis because of osmosis. Another theory states that the peptides merely compromise the integrity of the membrane by solubilizing the membrane. In order for the "pore" theory …

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Genetic Components Of (Co)Variance For Postweaning Growth, Carcass Composition And Meat Quality Traits Among Brahman-Influenced Beef Steers., D. H. Denny Crews Jr Jan 1996

Genetic Components Of (Co)Variance For Postweaning Growth, Carcass Composition And Meat Quality Traits Among Brahman-Influenced Beef Steers., D. H. Denny Crews Jr

LSU Historical Dissertations and Theses

A genetic analysis was conducted on preweaning and postweaning growth and carcass composition records from steers produced in two long-term crossbreeding studies. In phase I, Angus (A), Brahman (B), Brangus (BR), Charolais (C) and Hereford (H) sires produced straightbred, F$\sb1$, back-cross, three-breed cross and 2- and 3-breed rotational crossbred steers (N = 708) from 1960 to 1968. Straightbred, F$\sb1$, back-cross, three-breed cross and 2-, 3- and 4-breed rotational crossbred steers (N = 1530) were produced from 1970 to 1988 by A, B, C and H sires in phase II. Direct and maternal additive and non-additive genetic effect contrasts were obtained. …

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Analysis Of Host-Parasite Cospeciation: Effects Of Spatial And Temporal Scale., James W. Demastes Jan 1996

Analysis Of Host-Parasite Cospeciation: Effects Of Spatial And Temporal Scale., James W. Demastes

LSU Historical Dissertations and Theses

All species of pocket gophers (Geomyidae) are parasitized by at least one species of chewing louse (Trichodectidae), and recent genetic studies have demonstrated that a pattern of cospeciation exists between these hosts and parasites (Hafner and Nadler, 1988; Hafner et al., 1994). Little work has been done on this host-parasite system at lower taxonomic (intrageneric) levels. Although cospeciation is evident in a study of pocket gophers within the genus Geomys and their chewing lice (Geomydoecus), reticulate evolution and retention of ancestral lineages obscure the pattern (Chapter 2). One key to understanding how these patterns of cospeciation are produced and how …

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Foraging Behavior And Habitat Selection Of Insectivorous Migratory Songbirds At Gulf Coast Stopover Sites In Spring., Chao-Chieh Chen Jan 1996

Foraging Behavior And Habitat Selection Of Insectivorous Migratory Songbirds At Gulf Coast Stopover Sites In Spring., Chao-Chieh Chen

LSU Historical Dissertations and Theses

Abundance of some species of Nearctic-Neotropical migrants has been declining dramatically since 1970. Most literature about Neotropical migrants is from the breeding grounds, and some is from the wintering grounds; very little is from stopover sites. I studied foraging behavior and habitat selection of insectivorous migratory songbirds at three stopover sites along northern coast of the Gulf of Mexico during spring migrations of 1993-1995. Each migrant species had its unique combination of foraging behavior and habitat use during stopover. Migrants selected certain habitat strata and plant species and avoided others. The decrease of understory vegetation in the reduced plots had …

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Polymerase Chain Reaction (Pcr) Assay For The Detection And Differentiation Of The Virulent Strains Of Mycoplasma Mycoides Subspecies Mycoides "Small Colony" Type From The Vaccine T1 Strain In Purified Dna And In Field Samples From Africa., Abdullahi Sheikh Hassan Kalif Jan 1996

Polymerase Chain Reaction (Pcr) Assay For The Detection And Differentiation Of The Virulent Strains Of Mycoplasma Mycoides Subspecies Mycoides "Small Colony" Type From The Vaccine T1 Strain In Purified Dna And In Field Samples From Africa., Abdullahi Sheikh Hassan Kalif

LSU Historical Dissertations and Theses

Two primer sets were manufactured from the cytadhesin P1 gene of M. Pneumoniae in an attempt to amplify homologous sequences in M. mycoides subsp. mycoides "SC" Type in a search for a P1-like gene in the latter organism. The first primer set MP-2 amplifies a 488 bp fragment in M. pneumoniae. The second primer set MP-3 amplifies a 303 bp fragment bracketing the 13-amino acid binding domain in the same organism. Both primer sets amplified the expected fragments in all the virulent strains of M. mycoides subsp. mycoides "SC" type. The primer sets did not however amplify the expected fragments …

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Physical And Functional Characterization Of Long Terminal Repeat Of Equine Infectious Anemia Virus., Soo Ho Kim Jan 1996

Physical And Functional Characterization Of Long Terminal Repeat Of Equine Infectious Anemia Virus., Soo Ho Kim

LSU Historical Dissertations and Theses

The U3 region of long terminal repeat (LTR) of equine infectious anemia virus (EIAV) contains transcriptional regulatory elements. To identify the elements in prototype (P), fetal donkey dermal cell-adapted (A), and two variant (V) EIAV LTRs, DNase I footprinting, gel shift, and transient gene expression assays were performed. The assays used U937 monocytic cells which can be induced into macrophages by 12-O-tetradecanoylphorbol-13-acetate (TPA). For study of AP1 sites, c-Jun/AP1 was also used. Footprinting with nuclear extracts from TPA-induced and uninduced U937 cells localized methylated DNA-binding protein (MDBP), PEA2, AP1, PU.1, and CCAAT enhancer-binding protein (C/EBP) sites as common elements in …

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Chemical Effects On Microbial And Sensory Qualities Of Catfish In Planktonic And Dynamic Systems., Michael Adrain Land Jan 1996

Chemical Effects On Microbial And Sensory Qualities Of Catfish In Planktonic And Dynamic Systems., Michael Adrain Land

LSU Historical Dissertations and Theses

Listeria monocytogenes has the potential to be a serious pathogen for the compromised health segment of our population (immunocompromised, young, elderly and the pregnant). While the infectious dose is generally believed to be high 1.0 $\times$ 10$\sp6$, infectious dosages of 1.0 $\times$ 10$\sp3$ have been reported. Listeria monocytogenes poses a threat because of several factors: ubiquity in nature, isolation from fresh/salt waters, soil, ruminates and 17% of the human population. Listeria monocytogenes can colonize surfaces within 20 minutes, evade sanitizing, and is capable of growth from 37$\sp\circ$C to below refrigeration temperature. Fish and seafoods are high in water activity and …

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Impacts Of Fire And Vertebrate Herbivores On Plant Community Characteristics And Soil Processes In A Coastal Marsh Of Eastern Louisiana, United States Of America., Mark Alan Ford Jan 1996

Impacts Of Fire And Vertebrate Herbivores On Plant Community Characteristics And Soil Processes In A Coastal Marsh Of Eastern Louisiana, United States Of America., Mark Alan Ford

LSU Historical Dissertations and Theses

Both vertebrate herbivores and fire have long been known to have dramatic and important effects on wetlands. In the first part of this study, conducted in the Pearl River Basin coastal marshes of Louisiana, the interaction between the effects of mammalian herbivores, especially nutria and wild boar, and fire was examined in three marsh community types: those dominated by Sagittaria lancifolia, Panicum virgatum, or Spartina patens/Scirpus americanus. Overall, above-ground biomass was reduced by burning but increased by fencing. Richness only increased in plots that were both burned and fenced. In the three communities, only Scirpus americanus cover was enhanced by …

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Relationships Between Brain Biogenic Amines And Reproductive And Defense Behavior In Honey Bees (Apis Mellifera L.)., Jeffrey Wayne Harris Jan 1996

Relationships Between Brain Biogenic Amines And Reproductive And Defense Behavior In Honey Bees (Apis Mellifera L.)., Jeffrey Wayne Harris

LSU Historical Dissertations and Theses

This dissertation represents an attempt to relate behavioral states of worker honey bees to brain levels of biogenic amines. The first chapter describes the results of experiments which indicated that brain levels of octopamine, dopamine and serotonin were affected by factors including the degree of handling stress, worker age, season of sampling and the source colony from which the workers were sampled. These results helped shape the methods employed in the subsequent chapters. The second and third chapters relate changes in brain dopamine levels to worker honey bee ovarian development. In particular, chapter II showed that an increase in brain …

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Conditioning The Auditory System With Continuous Versus Interrupted Noise Of Equal Acoustic Energy: Is Either Exposure More Protective?, Ruth Ann Skellett Jan 1996

Conditioning The Auditory System With Continuous Versus Interrupted Noise Of Equal Acoustic Energy: Is Either Exposure More Protective?, Ruth Ann Skellett

LSU Historical Dissertations and Theses

Prior exposure to moderate-level acoustic stimulation (conditioning) can reduce and/or prevent the deleterious effects of subsequent higher level exposures (Canlon et al., 1988; Campo et al., 1991). Both continuous and interrupted schedules of moderate-level noise have been used as conditioning exposures, and both schedules have been effective in providing protection against subsequent noise trauma. However, there is evidence to suggest that continuous noise exposures are more damaging to the cochlea than interrupted exposures of equal acoustic energy (Bohne et al., 1985, 1987), and moderate-level continuous and interrupted noise exposures differ in the pattern of auditory sensitivity change that they produce …

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Postexercise Hypotension (Peh) In The Dog: Possible Role Of Immune System Cytokines., Gerald Dwayne Thompson Jan 1996

Postexercise Hypotension (Peh) In The Dog: Possible Role Of Immune System Cytokines., Gerald Dwayne Thompson

LSU Historical Dissertations and Theses

This study investigated postexercise hypotension (PEH) in five normotensive dogs testing these hypotheses: (1) PEH is present in the dog model; (2) high intensity exercise of 85% HR$\rm\sb{max}$ as compared to moderate intensity exercise of 60% HR$\rm\sb{max}$ induces a greater PEH; and (3) IL-1 and its activation of PGE$\sb2$ are associated with PEH. In experiment I, it was found that 85% HR$\rm\sb{max}$ exercise decreased systolic blood pressure (SBP) and mean arterial blood pressure (MABP) at 30 and 60 minutes postexercise (p $<$ 0.05). Both IL-1 and PGE$\sb2$ increased immediately following intense exercise, although temporal patterns were dissimilar. During non-exercise infusion of ibuprofen or dexamethasone (experiment II), blood pressure was not affected, but ibuprofen led to an overall inhibition of PGE$\sb2$. However, dexamethasone infusion led to a significant increase in PGE$\sb2$ at 180 and 210 minutes postinfusion. In experiment IIIA, after intense exercise following ibuprofen or saline infusion, PGE$\sb2$ increased at 120 to 180 minutes postexercise. Similar results were noted after exercise during dexamethasone treatment (experiment IIIB). In experiment IIIA & B, neither ibuprofen nor dexamethasone significantly affected PEH, although non-significant reductions in PEH was observed in dexamethasone treated animals. However, PGE$\sb2$ significantly increased after exercise at time points when PEH was not observed. These data indicate that (1) the intensity of exercise may have an effect on PEH, (2) there is partial support for the involvement of IL-1 and PGE$\sb2$ in PEH due to their immediate increase after exercise although a direct relationship was not observed, and (3) IL-1 still remains a possible mechanism responsible for PEH because of trends for attenuated PEH and PGE$\sb2$ responses following dexamethasone treatment.

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Famine, Plague, And Greed: Socio-Historical Factors Affecting The Development Of The Middle English Dialect Of London., George Vincent Yonek Jan 1996

Famine, Plague, And Greed: Socio-Historical Factors Affecting The Development Of The Middle English Dialect Of London., George Vincent Yonek

LSU Historical Dissertations and Theses

A significant factor in the rise of Standard English was the importance of London as a center of commerce and government, yet the foundation for Modern Standard English is not derived from the Southern dialects, which heavily influenced London in the late Old English and early Middle English period. The variety of English we speak and write today is derived mainly from the East Midland dialect and, to a lesser extent, the North in late Middle English. The purpose of this thesis is to explore the socio-historical causes behind this change in the distribution of features of the London dialect. …

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