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Effects Of Low-Oxygen Atmosphere On The Growth And Development Of Arabidopsis Thaliana (L.) Heynh., Katrina Maria Ramonell
Effects Of Low-Oxygen Atmosphere On The Growth And Development Of Arabidopsis Thaliana (L.) Heynh., Katrina Maria Ramonell
LSU Historical Dissertations and Theses
Interest in the improvement of crop productivity through repression of photorespiration led to experimental growth of plants in low O2 and the surprising finding that reproduction is inhibited under these conditions. Using Arabidopsis thaliana (L.) Heynh. cv. Columbia, studies were undertaken to understand the mechanism behind oxygen control of plant development. The hypothesis that developmental changes observed in low O 2 are due to repression of the plant hormones ethylene and brassinolide (which require O2 for biosynthesis) was tested. Arabidopsis was grown for 35 days in Sun bags in one of five altered O 2 atmospheres (210, 160, 100, 50, …
Epidemiology Of Anthrax In The Kruger National Park, South Africa: Genetic Diversity And Environment., Kimothy Lyn Smith
Epidemiology Of Anthrax In The Kruger National Park, South Africa: Genetic Diversity And Environment., Kimothy Lyn Smith
LSU Historical Dissertations and Theses
The Kruger National Park, (KNP), in the Republic of South Africa, provides a unique opportunity to investigate interesting and unresolved aspects of the epidemiology of the disease anthrax. Anthrax is a disease of primarily mammals caused by the Gram-positive, rod-shaped, spore-forming bacteria Bacillus anthracis. Beyond it's great historical significance anthrax is clearly important in the world today. From a rich legacy of empirical investigations and observations in the form of ecological and epidemiological studies conducted around the world this work endeavors to distill and extract the essence of what biotic and abiotic factors of environment might be causally associated with …
Community Structure And The Effects Of Experimental Fires On Hardwood Shrub Species In Southeastern Longleaf Pine Savannas., Paul Boguslaw Drewa
Community Structure And The Effects Of Experimental Fires On Hardwood Shrub Species In Southeastern Longleaf Pine Savannas., Paul Boguslaw Drewa
LSU Historical Dissertations and Theses
The main objective of this dissertation is to describe and examine how altering fire regimes in southeastern longleaf pine savannas may affect the abundances and distributions of indigenous plant species. In chapter one, I investigate whether herbs, compared to shrubs, have greater utility in delineating communities along elevation gradients of several meters in longleaf pine savannas. Herbaceous and shrub abundance data were analyzed separately for areas in Louisiana and Florida using cluster analysis and ordination. In Louisiana, three plant communities were sharply delineated and strongly correlated with gradients in elevation, surface soil moisture, and other surface soil properties. Herbaceous species …
Capability Of Recombinant Insect Viruses For Environmental Persistence And Transport., Yihua Lee
Capability Of Recombinant Insect Viruses For Environmental Persistence And Transport., Yihua Lee
LSU Historical Dissertations and Theses
Wild-type and recombinant nucleopolyhedroviruses (NPVs) were compared with respect to their capability to produce epizootics in Trichoplusis ni (Hubner) larvae infesting collards in a greenhouse microcosm. Viruses tested were variants of Autographa californica (Speyer) NPV (AcNPV): wild-type virus (AcNPV.WT), AcNPV expressing a scorpion toxin (AcNPV.AaIT), and AcNPV expressing juvenile hormone esterase (AcJHE.SG). Epizootics of AcNPV.WT lasted 8 weeks after a single viral release in the replicated, greenhouse micro-plots. AcJHE.SG epizootics also lasted 8 weeks after viral release, but this virus and AcNPV.AaIT were both out-competed by AcNPV.WT. AcNPV.AaIT was no longer detected in the T. ni population by the fourth …
Influence Of Environment And Genotype On The Expression Of Host Plant Resistance In Sweet Potato To The Sweet Potato Weevil, Cylas Formicarius (Fab.)., Lixin Mao
LSU Historical Dissertations and Theses
Field and laboratory experiments were conducted to study the influence of environment and genotype on the expression of sweetpotato resistance to the sweetpotato weevil (SPW), Cylas formicarius (Fab.). Roots of four genotypes ("W-244", "W-250", "Beauregard", "Centennial") were evaluated for SPW feeding and oviposition at three different storage times. Roots from Louisiana, South Carolina and Mississippi were also evaluated. Genotype had a significant effect on feeding and oviposition. Storage time and production sites appeared to affect resistance expression; the outcomes depend on the genotypes. The effect of nitrogen on sweetpotato resistance to SPW was studied. Four genotypes were grown in the …
Characterization Of A Simian Hemorrhagic Fever Virus Large Envelope Glycoprotein Gene And Its Product., Xiaochun Wang
Characterization Of A Simian Hemorrhagic Fever Virus Large Envelope Glycoprotein Gene And Its Product., Xiaochun Wang
LSU Historical Dissertations and Theses
The goal of this project was to determine the genome organization, replication strategy and identification of the large envelope glycoprotein (GL) gene of simian hemorrhagic fever virus (SHFV). This virus is the fourth member of the new virus family Arteriviridae. The 3' end of the RNA genome from the prototype isolate of SHFV was cloned and sequenced. This 6,314 nucleotide (nt) sequence consisted of nine complete overlapping open reading frame (ORFs 2, 2a, 3, 4, 5, 6, 7, 8, and 9). At the 5' end of this sequence is a partial ORF, ORF 1b, and the 3' end is a …
Molecular Genetics And Functions Of Herpes Simplex Virus Type 1 (Hsv-1) Glycoprotein K (Gk) In The Morphogenesis Of Infectious Virion Particles., Timothy Paul Foster
Molecular Genetics And Functions Of Herpes Simplex Virus Type 1 (Hsv-1) Glycoprotein K (Gk) In The Morphogenesis Of Infectious Virion Particles., Timothy Paul Foster
LSU Historical Dissertations and Theses
Herpes simplex virus type 1 (HSV-1) specifies at least 11 glycoproteins that are expressed in infected cells and in virions. HSV-1 enters into cells via fusion of the viral envelope with cellular membranes and can spread to adjacent cells via fusion of cellular membranes. Glycoproteins gB, gD, gH, and gL are known to be essential for virus entry, virus spread, and virus induced cell-to-cell fusion. The majority of spontaneous single amino acid changes that cause extensive cell fusion map within the UL53 gene encoding glycoprotein K (gK); however, the role of gK in virus entry and virus egress had not …
Null Codon-Based Models Of Synonymous And Nonsynonymous Substitution From A Phylogenetic Perspective., David A. Mcclellan
Null Codon-Based Models Of Synonymous And Nonsynonymous Substitution From A Phylogenetic Perspective., David A. Mcclellan
LSU Historical Dissertations and Theses
This dissertation focuses on the relationship between codon composition and the molecular evolution of protein-coding DNA sequences. Chapter 1 emphasizes the role of codon structure in determining patterns of nucleotide substitution, as well as the influence codon composition has on the evolution of the structure and function of the protein. The overall purpose of Chapter 1 is to establish the need to study molecular evolution at the codon level. In Chapter 2, the codon-degeneracy model (CDM) of molecular evolution is constructed. This model considers codon structure in terms of patterns of nucleotide site degeneracy. It allows the prediction of patterns …
Spatial Modeling Of Coastal Landscapes: Methodological And Scientific Applications., Mary Louise White
Spatial Modeling Of Coastal Landscapes: Methodological And Scientific Applications., Mary Louise White
LSU Historical Dissertations and Theses
A number of issues related to landscape scale ecological modeling of the wetlands of southern Louisiana are examined in this study. First, using geostatistical methods, a new contour map of the wetland habitats in the Terrebonne basin of southern Louisiana is constructed from data collected in 1994. This map is proposed as the best field verified habitat map of the Terrebonne basin and contains statistical confidence intervals associated with the habitat contours. Second, the problem of how to evaluate the success of a landscape model prediction is investigated. The multiple resolution goodness of fit parameter Ft(k) is evaluated in detail …
Effects Of Fluctuating Salinity, Nutritional State, And Temperature On Leptasterias Spp. From Little Port Walter, Alaska., Jeffrey William Tamplin
Effects Of Fluctuating Salinity, Nutritional State, And Temperature On Leptasterias Spp. From Little Port Walter, Alaska., Jeffrey William Tamplin
LSU Historical Dissertations and Theses
The effects of fluctuating salinity, nutritional state, and temperature on activity, oxygen consumption, feeding, and growth rates were analyzed on seasonally collected Leptasterias spp. (Echinodermata: Asteroidea) from Little Port Walter, AK. Leptasterias aspera and L. epichlora were collected on June 10, 1994, divided into size groups, and perivisceral fluid osmolality was measured every three hours during a 12 h 30-10-30‰S fluctuating cycle. The perivisceral fluid osmolality of larger individuals fluctuated less than that of smaller sea stars. The perivisceral fluid osmolality of small and large Leptasterias spp. closely tracks the ambient water osmolality during tidal cycles. Leptasterias spp. were collected …
Production Of L-(+) Lactic Acid From Blackstrap Molasses By Lactobacillus Casei Subspecies Rhamnosus Atcc 11443., Narumol Thongwai
Production Of L-(+) Lactic Acid From Blackstrap Molasses By Lactobacillus Casei Subspecies Rhamnosus Atcc 11443., Narumol Thongwai
LSU Historical Dissertations and Theses
Lactobacillus casei subspecies rhamnosus grew on non-supplemented blackstrap molasses. The bacteria grew best at the optimal temperature of 40 +/- 2°C, and at pH 5.5. Addition of yeast extract to molasses shortened the lag phase and increased cell mass. In batch fermentations without pH control, the highest ratio of lactic acid produced to cell mass was 12 from non-supplemented molasses. For pH controlled batch fermentations, the ratio's of lactic acid produced/cell mass were 81, 79, 51 and 31 for 0, 0.2, 0.4 and 0.8% yeast extract supplementation, respectively. Non-supplemented molasses, 8% Brix, produced 28 +/- 2 g/l of lactic acid …
Effects Of Repeated Restraint Stress On Tissue Metabolism In Rats., Jun Zhou
Effects Of Repeated Restraint Stress On Tissue Metabolism In Rats., Jun Zhou
LSU Historical Dissertations and Theses
It has been reported that repeated restraint stress (RS), 3 hours/day for 3 days, in rats caused sustained weight loss and a temporary drop in daily food intake with no subsequent compensatory overeating during the post stress period. The hypothesis tested in the present study is that RS causes peripheral tissue metabolism changes which account for the abnormal regulation of body weight and food intake during the post stress period. Adult male Sprague Dawley rats were assigned to control, pair fed (PF) or RS groups. One day after the end of RS, midbrain urocortin mRNA was at control levels in …
Phylogeography Of Two Loligo Squid (Cephalopoda: Myopsida) In The Gulf Of Mexico And The Northwestern Atlantic Ocean., Scott William Herke
Phylogeography Of Two Loligo Squid (Cephalopoda: Myopsida) In The Gulf Of Mexico And The Northwestern Atlantic Ocean., Scott William Herke
LSU Historical Dissertations and Theses
Based on restriction fragment length polymorphisms (RFLP) in mitochondrial DNA, the population structures of two species of Loligo squid were analyzed in the context of the classic Gulf of Mexico-Atlantic Ocean phylogeographic pattern. A 709-bp fragment of the cytochrome c oxidase (subunit I) gene was amplified by PCR from 356 L. pealei and 431 L. plei. Between latitudes 25°N and 43°N, each species had three common (>5% frequency) haplotypes and many rare haplotypes. Sequence data from all haplotypes indicated that nucleotide divergence between the two species ranged from 13.7 to 15.0% (transition-transversion ratio of ∼1.5; two inferred amino acid …
Production Of Transgenic Eastern Oysters., John Terrell Buchanan
Production Of Transgenic Eastern Oysters., John Terrell Buchanan
LSU Historical Dissertations and Theses
The eastern oyster, Crassostrea virginica, supports a valuable industry in the United States and Louisiana. In recent years this industry has been plagued by diseases, creating interest in the use of gene transfer to produce oysters capable of eliminating pathogens. The goal of this work was to develop techniques for laboratory research of eastern oysters, and for transfer of genes to oyster gametes, larvae, and adults. Cell culture provides an effective alternative to work in whole animals. Cell attachment and spreading on various culture substrates was improved, and poly-D-lysine was identified as a superior substrate. Toxicity of the antibiotic G418 …
Systematics Of The Common Garter Snake, Thamnophis Sirtalis., John Jeffrey Boundy
Systematics Of The Common Garter Snake, Thamnophis Sirtalis., John Jeffrey Boundy
LSU Historical Dissertations and Theses
Character variation was examined in the snake Thamnophis sirtalis . Initially, 187 characters were examined on five populations (OTUs). Only 12% of the characters failed to show geographic variation by ANOVA. A reduced data set of 72 characters remained after eliminating those that were invariant and correlated. The reduced data set was analyzed for interpopulation variation between 37 OTUs, of T. sirtalis. Numbers of significantly differentiated characters between OTUs, determined by ANOVA, were used to generate a UPGMA tree. The tree placed Texas and Chihuahuan populations as sister groups to all other OTUs, and grouped OTUs from west of the …
Systematics, Ecology, And Social Biology Of The Musk Duck (Biziura Lobata) Of Australia., Kevin Grant Mccracken
Systematics, Ecology, And Social Biology Of The Musk Duck (Biziura Lobata) Of Australia., Kevin Grant Mccracken
LSU Historical Dissertations and Theses
Musk Ducks (Biziura lobata) exhibit a number of unusual morphological and behavioral traits. The most notable of these include: greatly abducted hind-limbs for underwater swimming efficiency, extreme sexual size dimorphism and pronounced structural dimorphism, lek display activity, elaborate sexual display repertoires, and the distinctly non-waterfowl-like trait of provisioning young with all their food from the time of hatch until fledging. Despite such peculiarities and obvious theoretical potential in the areas of comparative morphology, sexual selection, and brood ecology, few studies of Musk Ducks have been undertaken, and those to date have been either small in scope and design, or focused …