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Measurement Of Deforestation In The Brazilian Amazon Using Satellite Remote Sensing, David Lewis Skole Jan 1992

Measurement Of Deforestation In The Brazilian Amazon Using Satellite Remote Sensing, David Lewis Skole

Doctoral Dissertations

A clear understanding of the role of the biota in the global carbon cycle is limited by an absence of accurate measurements of deforestation rates in the tropics. This study measures the rate and extent of deforestation in the Brazilian Amazon, a tropical forest biome approximately 5 $\times$ 10$\sp6$ km$\sp2$ in size and the largest extant tropical forest biome in the world. The study focuses on remote sensing measurements of deforestation rates and the area of secondary vegetation, but also utilizes tabular data to document deforestation when satellite data are not available. The analysis concludes: (1) Regression analysis of SPOT, …

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Molecular Phylogenies And Biogeography Of Central American Birds., Shannon J. Hackett Jan 1992

Molecular Phylogenies And Biogeography Of Central American Birds., Shannon J. Hackett

LSU Historical Dissertations and Theses

This dissertation presents data on the biogeography and molecular systematics of seven independent lineages of birds; both allozyme and mitochondrial DNA (mtDNA) characters were used. The purpose of this study was to discover biogeographic patterns among endemic taxa distributed in the highlands and lowlands of southern Central America and sister taxa in either North or South America. Analyses of the genera Diglossa, Buarremon, Pselliophorus, and Pezopetes suggested a complex biogeographic pattern in the highlands of southern Central America; divergence of some highland lineages occurred relatively recently (during the Pleistocene), after the landbridge connection between Central and South America was completed, …

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White Pine Weevil Response To Oak Overstory Girdling - Results From A 16-Year-Old Study, S.A. Katovich, F.S. Morse Jan 1992

White Pine Weevil Response To Oak Overstory Girdling - Results From A 16-Year-Old Study, S.A. Katovich, F.S. Morse

Aspen Bibliography

No abstract provided.

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The Purification Of Mcrb And Mcrc Proteins In Mcrbc Restriction System Of Escherichia Coli K12 And Dna Sequencing Of The Region Downstream Of Mcrc., Ling Zheng Jan 1992

The Purification Of Mcrb And Mcrc Proteins In Mcrbc Restriction System Of Escherichia Coli K12 And Dna Sequencing Of The Region Downstream Of Mcrc., Ling Zheng

LSU Historical Dissertations and Theses

The McrBC restriction system of Escherichia coli K12 degrades methylcytosine-containing foreign DNA. Two genes mcrB and mcrC had been shown to be required for the McrBC restriction (Ross, et al., J. Bacteriol., 1989b). To explore the involvement of additional gene(s), a 1.7 kb fragment downstream of the mcrC was cloned and sequenced. Also mutants containing deletion in mcrBC or the downstream region were isolated by transposon excision. Genetic complementation studies confirmed that only DNA containing mcrB and mcrC gene on a high copy plasmid were needed to fully restored McrBC restriction. Deletion of the 1.7 kb fragment from or addition …

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Physiology And Biochemistry Of A Lignin-Degrading Bacterium Erwinia Sp. Cu 3614., Janardhanan S. Rajan Jan 1992

Physiology And Biochemistry Of A Lignin-Degrading Bacterium Erwinia Sp. Cu 3614., Janardhanan S. Rajan

LSU Historical Dissertations and Theses

Previous researchers have reported the isolation of a diphenylether cleaving organism, Erwinia sp., using an enrichment medium containing lignin. A copper and dinitrophenol resistant mutant of this organism, Erwinia sp. Cu3614, has also been reported. To assess the effect of copper on the growth and biochemistry of this organism, continuous cultivation was used employing an apparently optimized medium containing ethanol as carbon source. Upon increasing the concentration of copper sulfate in the medium from 5 $\mu$g/ml to 10 $\mu$g/ml increases in maximum specific growth rate and growth yield were seen. Also decrease in the values for doubling time and the …

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Shoot Growth And Form Of Senna Obtusifolia In Response To Soybean And Intraspecific Competition., James Edward Smith Jan 1992

Shoot Growth And Form Of Senna Obtusifolia In Response To Soybean And Intraspecific Competition., James Edward Smith

LSU Historical Dissertations and Theses

Effects of competition on growth and formation of shoot structure in sicklepod (Senna obtusifolia) were examined, with particular emphasis on the effect of nearest neighbors on branching and canopy formation. Sicklepod was established as (1) stands of 26 plants m$\sp{-2}$ added to soybean, (2) individuals widely enough spaced to produce only interspecific competition when added to soybean, or (3) regularly spaced monoculture stands with 15, 25, 35, and 50 cm interplant distances. Repeated surveys of individual shoots characterized sicklepod growth and shoot structure in terms of position of and growth at each node. Sicklepod leaf area, internode elongation, node production, …

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Selection And Characterization Of Populations Of Rapid-Cycling Brassica Rapa L. Differing In Their Response To Rootzone Hypoxia., Christine Jo Daugherty Jan 1992

Selection And Characterization Of Populations Of Rapid-Cycling Brassica Rapa L. Differing In Their Response To Rootzone Hypoxia., Christine Jo Daugherty

LSU Historical Dissertations and Theses

Challenging a heterogenous population of plants (rapid-cycling Brassica rapa L.) with waterlogging, we selected plants which differed in their response to rootzone hypoxia. Based on visual criteria, individuals from the waterlogged wild-type population were separated into "tolerant" and "sensitive" groups and mass pollinated to produce the next generation. This selection protocol was continued for seven generations. Under waterlogged conditions, chlorophyll concentrations in the tolerant population were significantly greater than in the sensitive population. After eight days of waterlogging, tolerant plants had significantly greater dry root and shoot weights than the sensitive plants. However, when tolerant and sensitive populations were grown …

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Investigations Into The Pathogenesis Of Acute Equine Laminitis., Linda Elizabeth Cummings Jan 1992

Investigations Into The Pathogenesis Of Acute Equine Laminitis., Linda Elizabeth Cummings

LSU Historical Dissertations and Theses

A profound decrease in perfusion of the laminar capillaries has been documented during acute equine laminitis, resulting in ischemia of the laminar tissue. Oxygen radicals are believed to mediate ischemia/reperfusion injury. The effects of (1) three hours of surgical ligation of the major blood supply of the equine digit followed by ligature release, (2) resection of the medial and lateral palmar digital arteries, and (3) digital intraarterial infusions of an oxygen radical generating system, were investigated. Laminitis was not induced by any of these manipulations. Clinical signs and alterations in hemograms observed following these procedures are reported. Preliminary identification of …

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Physiological Studies On Postharvest Leaf Blackening In Cut Flower Protea Species., Margaret Robyn Mcconchie Jan 1992

Physiological Studies On Postharvest Leaf Blackening In Cut Flower Protea Species., Margaret Robyn Mcconchie

LSU Historical Dissertations and Theses

To develop an understanding of the physiology which results in postharvest leaf blackening, cut flower Protea species were studied in relation to changes in leaf carbohydrate metabolism, membrane deterioration, and oxidative enzyme activity. Rapid development of leaf blackening in the dark was correlated with low starch and sucrose concentrations. Postharvest decline in leaf carbohydrate status appears to be associated with inflorescence sink demand. Leaf blackening was reduced in the light and carbohydrate pools were maintained due to photosynthesis. In floral stems of P. neriifolia, P. Susannae x compacta and P. eximia (which have differing susceptibilities to leaf blackening), leaf blackening …

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The Molecular Systematics Of Unitunicate, Perithecial Ascomycetes., Joseph William Spatafora Jan 1992

The Molecular Systematics Of Unitunicate, Perithecial Ascomycetes., Joseph William Spatafora

LSU Historical Dissertations and Theses

Maximum parsimony analysis of partial sequences from the small subunit ribosomal DNA (ssrDNA) rejects the monophyly of unitunicate, perithecial ascomycetes (pyrenomycetes). The genera Kathistes, Pyxidiophora and Subbaromyces are separated from a large clade of relatively derived pyrenomycetes. This derived pyrenomycete clade is supported by a bootstrap confidence level of 100% and a decay index of $>$10 steps, and contains two subclades, A and B. Subclade A comprises the orders Clavicipitales, Hypocreales, Microascales and the genus Ceratocystis; subclade B consists of the Diaporthales, Sordariales, Xylariales and the genus Ophiostoma. The Clavicipitales is a sister taxon to the Hypocreales, which consists …

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Studies On Escherichia Coli Cell Division: Overexpression, Purification, And Quantitative Determination Offtsa Protein., Haichao Wang Jan 1992

Studies On Escherichia Coli Cell Division: Overexpression, Purification, And Quantitative Determination Offtsa Protein., Haichao Wang

LSU Historical Dissertations and Theses

FtsA is an essential cell division protein which is synthesized in minute amounts in Escherichia coli. To study the effects of overexpressing ftsA on the phenotype of E. coli cells, DNA fragments encoding the ftsA gene were subcloned downstream of a lac or a tac promoter in two plasmids. High-level expression of the ftsA gene from these promoters inhibited normal cell septation and caused the cells to become long, nonseptate filaments. Continued overexpression of ftsA resulted in the filaments developing spherical bulges up to 4 um in diameter. It is suggested that these bulges may emanate from septation sites because …

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The Role Of Bovine Herpesvirus-1 Glycoprotein Iii In Molecular Pathogenesis And Immunomodulation., Katherine Marie Byrne Jan 1992

The Role Of Bovine Herpesvirus-1 Glycoprotein Iii In Molecular Pathogenesis And Immunomodulation., Katherine Marie Byrne

LSU Historical Dissertations and Theses

Bovine herpesvirus-1 (BHV-1) is the pathogenic agent for infectious bovine rhinotracheitis. Current vaccines to protect against infection have serious disadvantages to producers and have been implicated in epizootic outbreaks. The virus has also been shown to cause suppression of the immune system. BHV-1 vaccines could be improved by identifying and genetically deleting those aspects of the virus responsible for immunosuppression and providing a marker within the genome which would distinguish the vaccine strain from wild types in the case of disease outbreaks. This study examined the role of gIII in viral infection and immunosuppression. This was accomplished by expressing full …

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Effects Of Hydrologic Alterations On The Vegetation And Soils Of Marshes In Southern Louisiana., Kathryn Marie Flynn Jan 1992

Effects Of Hydrologic Alterations On The Vegetation And Soils Of Marshes In Southern Louisiana., Kathryn Marie Flynn

LSU Historical Dissertations and Theses

Hydrology is the primary forcing function in wetlands. Therefore, alterations to hydrology, which can result from either natural or anthropogenic causes, can have dramatic effects on wetland structure and function. Structural marsh management, one type of anthropogenic alteration, employs levees and water control structures to reduce or reverse wetland loss and enhance the productivity of natural renewable resources. Its use is becoming increasingly popular in southern Louisiana as a solution to the problem of marsh deterioration despite the fact that very line comprehensive data is available on the effectiveness of this practice. Associated with the use of structural marsh management …

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Development Of Various Quantitative And Analytical Methods For The Analysis Of The Dynamics Of Fish Populations: An Application To The Spotted Seatrout Population In Coastal Louisiana., Thomas Earl Helser Jan 1992

Development Of Various Quantitative And Analytical Methods For The Analysis Of The Dynamics Of Fish Populations: An Application To The Spotted Seatrout Population In Coastal Louisiana., Thomas Earl Helser

LSU Historical Dissertations and Theses

Presented in this dissertation are analytical and quantitative methods developed for an experimental gillnet sampling program for the analysis of the dynamics of fish populations, illustrated here on Louisiana's spotted seatrout population. Chapter 1 presents a new method of estimating gillnet selectivity using a system of simultaneous equations and a non-linear iterative maximum likelihood approach. The model solution is a set of parameter estimates which mathematically describe the response surface of capture probabilities for fish of size-class j in mesh size i. As an extension to the nonlinear maximum likelihood gillnet selectivity model, Chapter 2 presents a second approach using …

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Chemical And Immunological Properties Of Polysaccharide Extracted From Vibrio Parahaemolyticus., Mina Jassemzadeh Izadjoo Jan 1992

Chemical And Immunological Properties Of Polysaccharide Extracted From Vibrio Parahaemolyticus., Mina Jassemzadeh Izadjoo

LSU Historical Dissertations and Theses

The capsular polysaccharide (CPS) of Vibrio parahaemolyticus was extracted from agar grown cells and purified by ethanol precipitation, hi-speed centrifugation and chromatography on Sepharose CL-4B and Detoxi columns. The CPS was found to be acidic when chromatographed on DEAE cellulose. The three constituting sugars were determined by gas-liquid chromatography to be glucose, galactose and fucose. The molecular weight of CPS is one million or greater and in its pure form appeared to be non-immunogenic for rabbits. A monoclonal antibody (Mab) reactive by ELISA to CPS was generated. The Mab agglutinated whole cell suspensions in the slide test. Latex beads armed …

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Genetic And Systematic Study Of Viviparus Georgianus (Lea), A Freshwater Snail Species Complex., Masaya Katoh Jan 1992

Genetic And Systematic Study Of Viviparus Georgianus (Lea), A Freshwater Snail Species Complex., Masaya Katoh

LSU Historical Dissertations and Theses

Genetic and morphological variation were studied in a brooding (ovoviviparous) and morphologically variable freshwater snail (Viviparus georgianus (Lea)) in the southeastern United States. Eleven populations were clustered into three genetically isolated, allopatric species characterized by 7 to 15 diagnostic loci out of the 38 loci examined. These allopatric species were an eastern species (in eastern and southern Florida), a western species (in the Florida panhandle), and a central species in the Ochlockonee River. Nei's standard genetic distances between species were large (0.23-0.52) compared to within-species distances (0.00-0.06). Moreover, genetic distances between the Ochlockonee River species and other species were larger …

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Control Of Phytoplankton Production In A Shallow, Turbid Estuary., Christopher J. Madden Jan 1992

Control Of Phytoplankton Production In A Shallow, Turbid Estuary., Christopher J. Madden

LSU Historical Dissertations and Theses

Water column primary production and chlorophyll were sampled between 1986-1991 in Fourleague Bay, LA, a shallow (1.5 m), river-dominated estuary that is extremely turbid (K$\sb{\rm D}$ = 4.44 m$\sp{-1}$). A high speed system for continuous flow-through sampling, Dataflow$\sp\copyright$, was developed to measure physicochemical variables and in vivo chlorophyll fluorescence at high temporal (1 s) and spatial (5 m) resolution from a small boat. Phytoplankton net primary production (NPP) was measured using an incubator which rotated bottles to prevent settling of the contents. NPP was found to be artificially increased by 10-83% at high light levels in non-rotated bottles when cells …

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Host Quality Of Baldcypress And Its Influence On Fruittree Leafroller, Archips Argyrospila (Walker) (Lepidoptera: Tortricidae), Performance In Forested Wetlands Of Louisiana., James R. Meeker Jan 1992

Host Quality Of Baldcypress And Its Influence On Fruittree Leafroller, Archips Argyrospila (Walker) (Lepidoptera: Tortricidae), Performance In Forested Wetlands Of Louisiana., James R. Meeker

LSU Historical Dissertations and Theses

Ecological relationships between the fruittree leafroller (FTLR), (Archips argyrospila (Walker)) and a new host, baldcypress (Taxodium distichum (L.)), were investigated in southern Louisiana where persistent annual defoliation over increasingly larger areas has occurred since 1983. Defoliation was observed to correspond with common types of baldcypress foliage morphology; designated as open and appressed. Pondcypress, Shumard oak and citrus foliage also were examined. The objectives were to: (1) determine the relative suitability/susceptibility of foliage types, and (2) quantify parameters of foliage quality possibly influencing FTLR performance. Levels of defoliation, egg mass counts, and laboratory bioassays of: initial survival, host preference, growth, feeding, …

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Diagnostic Techniques For Detection Of Permethrin-Resistant Soybean Loopers, Pseudoplusia Includens (Walker), Determination Of The Impact Of Insecticide Treatments On Age-Specific Mortality And Feeding Activity, And Estimation Of Field Control., Jeffrey Scott Mink Jan 1992

Diagnostic Techniques For Detection Of Permethrin-Resistant Soybean Loopers, Pseudoplusia Includens (Walker), Determination Of The Impact Of Insecticide Treatments On Age-Specific Mortality And Feeding Activity, And Estimation Of Field Control., Jeffrey Scott Mink

LSU Historical Dissertations and Theses

A glass vial bioassay was developed to detect permethrin resistance in soybean looper, Pseudoplusia includens (Walker), larvae. Third, fourth, fifth, and sixth instar soybean loopers from laboratory (susceptible) and field strains were exposed to several concentrations of permethrin in 20 ml glass vials. LC$\sb{50}$'s for third, fourth, and fifth instars from each field strain were not significantly different. A discriminating concentration of 0.5 $\mu$g permethrin per vial was identified for detection of permethrin resistance in soybean looper field populations. Field strains from cotton-soybean agroecosystems exhibited higher levels of resistance than strains from soybean-corn agroecosystems. The reliability of the vial bioassay …

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The Effect Of Threecornered Alfalfa Hopper Populations On Alfalfa Growth And The Development Of Host Plant Resistance Screening Techniques., Daniel John Moellenbeck Jan 1992

The Effect Of Threecornered Alfalfa Hopper Populations On Alfalfa Growth And The Development Of Host Plant Resistance Screening Techniques., Daniel John Moellenbeck

LSU Historical Dissertations and Theses

This dissertation research was designed with three main objectives: to evaluate the effects of threecornered alfalfa hopper, Spissistilus festinus (Say), feeding on alfalfa, Medicago sativa L., yield, regrowth, root carbohydrate composition, and disease incidence; to screen alfalfa cultivars for resistance to the threecornered alfalfa hopper and develop effective screening techniques; and to determine the mechanism(s) of this resistance. Greenhouse studies determined the effects of threecornered alfalfa hopper infestations on alfalfa growth and their relationship with Fusarium crown-rot. Significant interaction effects between insect population and the presence of Fusarium were found for number of harvestable stems and acid detergent fiber concentration. …

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Integrated Pest Management Studies Of The Cotton Aphid, Aphis Gossypii Glover., Patti Jane O'Brien Jan 1992

Integrated Pest Management Studies Of The Cotton Aphid, Aphis Gossypii Glover., Patti Jane O'Brien

LSU Historical Dissertations and Theses

Studies were conducted to characterize insecticide resistance and to document aspects of the basic biology of the cotton aphid, Aphis gossypii Glover, that were related to recommendations for integrated pest management. Laboratory, greenhouse, and field techniques were employed in these investigations. Significant levels of resistance were demonstrated to four recommended insecticide classes. Resistance appeared more stable over time for the organophosphate insecticide (chlorpyrifos) than for the organochlorine (endosulfan) and pyrethroid (bifenthrin) insecticide tested. The organophosphate resistance ratio of a clonal line of the cotton aphid was significant, but relatively low. Carboxylesterases, as studied by spectrophotometric and electrophoretic techniques, appeared involved …

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Phylogenetic Systematics Of The Ulvophyceae (Chlorophyta) Based On Cladistic Analyses Of Ribosomal Rna Genes And Morphology., Frederick William Zechman Jan 1992

Phylogenetic Systematics Of The Ulvophyceae (Chlorophyta) Based On Cladistic Analyses Of Ribosomal Rna Genes And Morphology., Frederick William Zechman

LSU Historical Dissertations and Theses

Cladistic analyses of non-molecular and nuclear-encoded rRNA sequence data provided the basis for hypotheses of relationships for the green algal class Ulvophyceae. Non-molecular data rooted with Chara support hypotheses which group the Chlorophyceae and Pleurastrophyceae with ulotrichalean and ulvalean Ulvophyceae. Analyses of rRNA sequence data group the siphonous and siphonocladous Ulvophyceae (i.e. Caulerpales, Siphonocladales, and Dasycladales) with the Chlorophyceae and Pleurastrophyceae. Although hypotheses supported by these independent data sets are incongruent, they suggest that the Ulvophyceae is not monophyletic. Based on rRNA sequences, pleurastrophycean taxa, which, like the Ulvophyceae, possess a counter-clockwise arrangement of flagellar basal bodies, are more closely …

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Taxonomic Treatment Of Indigofera L. (Fabaceae: Faboideae) In The New World., Alan Wayne Lievens Jan 1992

Taxonomic Treatment Of Indigofera L. (Fabaceae: Faboideae) In The New World., Alan Wayne Lievens

LSU Historical Dissertations and Theses

The current taxonomic study of Indigofera (Fabaceae) as it occurs in the New World has several aims. The first addresses taxonomic and nomenclatural issues related to North American taxa. Because such issues have not been well understood for many of these taxa at various ranks, a synopsis of all taxa known to be referable to North America is presented along with a thorough discussion of nomenclatural issues (including synonymy) for each. This discussion is initially placed within the framework of the species groups proposed by Rydberg in 1923. A preliminary cladistic analysis of these North American species groups is presented. …

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Influences On The Instream Distribution Of Astyanax Fasciatus In A Small River In Costa Rica., Cecil Kelly Swing Jan 1992

Influences On The Instream Distribution Of Astyanax Fasciatus In A Small River In Costa Rica., Cecil Kelly Swing

LSU Historical Dissertations and Theses

The instream distribution of the tetra, Astyanax fasciatus, was investigated through approximately 700 hours of field observations in a small Costa Rican stream on the southwestern Pacific coast near Golfito. Individuals tended to remain in particular pools where they subsisted primarily on a diet of terrestrial insects. These fish were able to migrate, and only as many individuals stayed in any pool as could be sustained there by available food resources. Because the water intercepted insects fairly uniformly over its surface, the biomass of fish occupying any particular pool was proportional to its surface area (r$\sp2$ = 0.652). The amount …

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Effects Of Vertebrate Herbivory On Louisiana Coastal Marshes., Katherine Lynn Taylor Jan 1992

Effects Of Vertebrate Herbivory On Louisiana Coastal Marshes., Katherine Lynn Taylor

LSU Historical Dissertations and Theses

The disturbances of herbivory, simulated "eat-outs" (clipping and removal of above-ground biomass), and burning were examined for their effect on total biomass, individual species abundance, and species richness in several different marsh communities. Herbivory significantly reduced the total community biomass of all the marshes studied. Simulated "eat-outs" reduced the total biomass of the freshwater marsh but had no persistent effect on the total biomass of either the oligohaline or mesohaline marshes of the Pearl River. Both the oligohaline and the mesohaline marshes were able to recover from a removal of above-ground biomass (simulated "eat-out") within two years. The freshwater marsh …

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Characterization Of Gentamicin Resistance In Enteric Bacteria Isolated From Pseudomys Scripta-Elegans From Commercial Turtle Farms., Michelle Anne Brassett Jan 1992

Characterization Of Gentamicin Resistance In Enteric Bacteria Isolated From Pseudomys Scripta-Elegans From Commercial Turtle Farms., Michelle Anne Brassett

LSU Historical Dissertations and Theses

Several genera of aminoglycoside resistant enteric bacteria were isolated from commercial turtle farms. Citrobacter freundii and Proteus vulgaris were the most prevalent organisms. Gentamicin resistance, measured by minimum inhibitory concentrations (MIC), ranged as high as 100 $\mu$g/ml. While resistance to other antibiotics was detected in gentamicin-resistant isolates, no correlation was observed between antibiotic resistance and plasmid content. Spontaneous mutation to gentamicin could not account for the high levels of gentamicin resistance found in the original isolates. Regions of chromosomal DNA encoding gentamicin resistance of 100 $\mu$g/ml were obtained from two Citrobacter freundii, two Proteus vulgaris, and two Salmonella enteritidis strains. …

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The Use Of Hydrologically Altered Wetlands To Treat Wastewater In Coastal Louisiana., Andree Marie Breaux Jan 1992

The Use Of Hydrologically Altered Wetlands To Treat Wastewater In Coastal Louisiana., Andree Marie Breaux

LSU Historical Dissertations and Theses

Two major environmental problems currently affecting Louisiana are a high rate of coastal wetland loss and high levels of surface water pollution. The application of secondarily treated wastewater to wetlands is proposed as a means of dealing with these problems. The benefits of wetland wastewater treatment include improved surface water quality, increased accretion rates to balance subsidence, improved plant productivity, and decreased capital outlays for conventional engineering treatment systems. Wetland treatment systems can be designed and operated to restore deteriorating wetlands to previous levels of productivity. Hydrologically altered wetlands in the Louisiana coastal zone have been selected as appropriate for …

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A Novel Process For The Production Of Clinical Dextran., Doman Kim Jan 1992

A Novel Process For The Production Of Clinical Dextran., Doman Kim

LSU Historical Dissertations and Theses

A new process for the production of clinical (or controlled size) dextran was developed. This process is simpler, cheaper and more economical than traditional methods. It involves the use of a mixed culture fermentation with a dextranase producing strain (Lipomyces starkeyi ATCC 74054) and a dextransucrase producing strain (Leuconostoc mesenteroides ATCC 10830). The new process produced 84% (w/w) of theoretical yield clinical dextran with an average polydispersity between 1.2 and 1.5. The mechanism of clinical dextran formation is the competitive production of acceptors from newly formed dextran molecules by dextranase. The acceptors compete for the existing glucosyl portion of sucrose, …

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Behavioral Influences On Predator-Prey Interactions Between Juvenile Teleosts And Meiofauna., John Nathan Mccall Jan 1992

Behavioral Influences On Predator-Prey Interactions Between Juvenile Teleosts And Meiofauna., John Nathan Mccall

LSU Historical Dissertations and Theses

Predator-prey relationships between post-larval and juvenile teleosts are greatly influenced by the manner in which feeding behavior of fish interacts with the behavior of meiofaunal prey. Juvenile starry flounder (Platichthys stellatus Pallas) in a southeastern Alaskan bay fed disproportionately on the harpacticoid copepod Microarthridion littorale (Poppe), particularly on males. This apparent selectivity was not due to differing vertical distribution of harpacticoid species or to feeding in other locations. Comparison of ingested prey to harpacticoid assemblages collected by various techniques (including near-bottom collections) suggested that the prey selection shown by starry flounder may be the result of emergent behavior of its …

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Assemblage Of Spinach Photosystem Ii Proteins: Cpa-1 And Msp Interactions., Carlos Benito Queirolo Jan 1992

Assemblage Of Spinach Photosystem Ii Proteins: Cpa-1 And Msp Interactions., Carlos Benito Queirolo

LSU Historical Dissertations and Theses

This work focuses on the production and characterization of crosslinked products obtained from PS II preparations, with the aim of better understanding the structural relationships between the manganese stabilizing protein (MSP) and the interior antenna protein CPa-1. Two oxygen evolving reaction center (OERC) preparations, OERC complex and OERC core, produced various crosslinked products with the hydrophobic crosslinker dithio-bis-(succinimidyl propionate) (DTSP). Crosslinking experiments with OERC complex demonstrated that a close association of MSP to CPa-1 occurs, as both proteins were found to be present simultaneously in various crosslinked products revealed by one- and two-dimensional electrophoretic and immunoblotting techniques. These crosslinked products …

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