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Evaluation Of Insecticide Resistance In Louisiana Adult Mosquitoes And The Efficacies Of Selected Larvicides., Stacy Lee Bearden
Evaluation Of Insecticide Resistance In Louisiana Adult Mosquitoes And The Efficacies Of Selected Larvicides., Stacy Lee Bearden
LSU Historical Dissertations and Theses
Pesticide resistance in Louisiana mosquitoes has never been examined on a state-wide basis. In 1996, first component of this monitoring program examined selected pesticide efficacies and documented current pesticide resistance. Ground ULV-applied FyfanonRTM (96.8% malathion and Pyrocide RTM (96.8% + 1% natural pyrethrum) were applied to caged Culex quinquefasciatus adults (Denham Springs [Livingston Parish] and Lake Charles [Calcasieu Parish]) and Aedes sollicitans (Vermilion Parish). FyfanonRTM caused significantly different (p < 0.05) mortalities among each species and strain within 24hrs (95% Aedes, 48% Denham Springs, and 14% Lake Charles). Pyrocide RTM also produced significantly different mortalities (99%, 70%, and 38%, respectively). Malathion and permethrin were topically applied to 3--5 day old adult mosquitoes from 14 parishes. St. Martin parish Cx. quinquefasciatus was most susceptible to malathion (2.58 mug/mul), and the Vermilion strain was most resistant (417.05 mug/mul). Resistance is based on a ≥5-fold resistance ratio. Calcasieu parish strain was least resistant to permethrin (1.93 mug/mul), and the St. Tammany parish strain was most resistant (40.86 mug/mul). Detecting pesticide resistance by bottle bioassay technique was compared to topical bioassay. Both techniques were effective in detecting resistance for selected Aedes, Anopheles, and Culex species in Louisiana. Ground ULV 97% malathion was applied to caged Cx. quinquefasciatus adults from a mosquito abatement district, agrichemical farmland, and a susceptible colony. No significance (p > 0.05) existed in mosquito mortality between the agrichemical area and the abatement district. Bacillus thuringiensis var. israeliensis (VectoBacRTM WDG and VectoBacRTM 12AS) and Bacillus sphaericus (VectoLexRTM WDG and VectoLexRTM CG) were …
Litterfall Dynamics And Nutrient Cycling In Mangrove Forests Of Southern Everglades, Florida And Terminos Lagoon, Mexico., Carlos Antonio Coronado Molina
Litterfall Dynamics And Nutrient Cycling In Mangrove Forests Of Southern Everglades, Florida And Terminos Lagoon, Mexico., Carlos Antonio Coronado Molina
LSU Historical Dissertations and Theses
The objective of this dissertation was to investigate the processes that control litterfall and nutrient dynamics in two contrasting mangrove ecosystems at the Southeastern (SE) Everglades and Terminos Lagoon. The main objectives were: (a) to determine the spatial and temporal variability of litterfall dynamics, (b) to evaluate the relative importance of nutrient use efficiency as a nutrient conservation mechanism along a natural nutrient gradient, and (c) to assess the relative importance of nutrient resorption on litterfall dynamics. Two hypotheses were tested: (a) mangrove species living in nutrient-poor environments and in nutrient-rich environments do not differ in the efficiency in using …
A Case Study In Amazonian Biogeography: Vocal And Dna -Sequence Variation In Hemitriccus Flycatchers., Mario Cohn-Haft
A Case Study In Amazonian Biogeography: Vocal And Dna -Sequence Variation In Hemitriccus Flycatchers., Mario Cohn-Haft
LSU Historical Dissertations and Theses
Ongoing debate about the evolutionary history of the Amazonian avifauna suffers from a shortage of data. Especially needed are thorough geographic sampling, sensitive markers of genetic diversity, and historical data in the form of explicit phylogenies. I examined patterns of geographic variation in three widespread species complexes of nearly identical Amazonian flycatchers in the genus Hemitriccus, based on spectrographic analysis of vocalizations and phylogenetic analysis of DNA sequences (1026 base pairs of cytochrome b from 44 individuals) from throughout Amazonia. Although members of the three complexes are extremely difficult to distinguish morphologically and have long been confused by taxonomists, they …
Molecular Systematics And Historical Biogeography Of The Tree Shrews (Tupaiidae)., Kwai Hin Han
Molecular Systematics And Historical Biogeography Of The Tree Shrews (Tupaiidae)., Kwai Hin Han
LSU Historical Dissertations and Theses
This dissertation examined the molecular systematics and historical biogeography of tree shrews (Tupaiidae). Comparison of cytochrome b sequences and DNA hybridization data suggests that cytochrome b sequences evolved 7.9 to 13.4 times faster than single-copy nuclear DNA. These two data sets are taxonomically congruent. They indicate that the Mindanao tupaiid Urogale everetti is a member of Tupaia, and that there is lineage-based variation in rates of evolution among the tupaiids. A new species of Tupaia from Sarawak (Malaysia), T. stuebingi, was described using morphological, ecological, and cytochrome b sequence data. This lowland species is generally similar in size to the …
Isolation And Characterization Of Newly Emerging Coronaviruses In Acute Respiratory Tract Diseases Of Cattle., Xiaoqing Lin
Isolation And Characterization Of Newly Emerging Coronaviruses In Acute Respiratory Tract Diseases Of Cattle., Xiaoqing Lin
LSU Historical Dissertations and Theses
A total of 411 G clone cell-dependent virus strains recently were isolated from nasal, trachea and lung samples in etiological investigations of acute respiratory tract diseases of vaccinated cattle, including shipping fever pneumonia. The virus infectivity titers reached up to 1.2 x 10 7 plaque forming units per gram of lung tissues of fatal cases. These viral agents were isolated in the 1st G clone cell passage without trypsin enhancement, and induced cell fusion. They have a restricted hemagglutination pattern, agglutinating only rat and mouse erythrocytes. Majority of them has receptor-destroying enzyme activities. They are round and enveloped with a …
Effects Of Bacillus Thuringiensis Transgenic Cotton On Soybean Looper, Pseudoplusia Includens (Walker) (Lepidoptera: Noctuidae): Larval Development, Mortality, Population Dynamics, And Resistance Management On Soybean., Christopher Glen Clemens
Effects Of Bacillus Thuringiensis Transgenic Cotton On Soybean Looper, Pseudoplusia Includens (Walker) (Lepidoptera: Noctuidae): Larval Development, Mortality, Population Dynamics, And Resistance Management On Soybean., Christopher Glen Clemens
LSU Historical Dissertations and Theses
In laboratory bioassays, total mortality (neonate to pupation) among Bt-cotton varieties ranged from 13 to 89%; however, only cvs. CK 312/531, NuCOTN 33B, and PM 1220 RR/BG caused greater mortality than the soybean and meridic diet controls. Several Bt-cotton hosts increased larval developmental time, but none of the commercial Bt-cotton varieties (excluding CK 312/531) significantly affected adult longevity, generation time, doubling time, or intrinsic rate of increase (rm). Soybean looper larval and predator densities were monitored in soybean fields to determine the impact of Bt-cotton production on soybean looper seasonal abundance. Throughout the study, peak soybean looper larval densities were …
Evaluation Of Heterologous Promoter Function In The Eastern Oyster (Crassostrea Virginica)., Ta Philip Chih Cheng
Evaluation Of Heterologous Promoter Function In The Eastern Oyster (Crassostrea Virginica)., Ta Philip Chih Cheng
LSU Historical Dissertations and Theses
The goal of this work was to evaluate the feasibility of using antimicrobial peptide gene transfer to enhance oyster immunity. The specific objectives were to: (1) compare the efficiency of collagenase, pronase, and trypsin to dissociate atrium, ventricle and mantle into individual cells for the initiation of primary cell culture; (2) develop cryopreservation conditions to preserve the dissociated cells; (3) establish a serum-free transfection system; (4) evaluate inducible promoter function using the established serum-free transfection system; (5) evaluate the effects of the transfer of antimicrobial peptide genes on oyster immunity. Pronase was found to be the most effective enzyme for …
The Effects Of Equine Somatotropin (Est) On Reproductive Function In The Domestic Mare., Richard Anthony Cochran
The Effects Of Equine Somatotropin (Est) On Reproductive Function In The Domestic Mare., Richard Anthony Cochran
LSU Historical Dissertations and Theses
The effects of somatotropin on ovarian reproductive function has become a keen research area in mammalian species over the past decade. However, to date, very little information is available as to the effects of somatotropin administration on reproduction in the domestic mare. Therefore, the purpose of these experiments was (1) to determine the potential effects (if any) of administration of exogenous equine somatotropin on ovarian follicular development and plasma and follicular fluid hormone concentrations in cyclic and noncyclic mares, (2) to determine the mechanism(s) of action of somatotropin treatment on these parameters in the mare, (3) to develop an efficient …
The Early Local And Regional Immune Response To Recall Inoculations Of Mycobacterium Leprae In The Skin Of Rhesus Macaques (Macaca Mulatta)., Thomas Xavier D Lemarchand
The Early Local And Regional Immune Response To Recall Inoculations Of Mycobacterium Leprae In The Skin Of Rhesus Macaques (Macaca Mulatta)., Thomas Xavier D Lemarchand
LSU Historical Dissertations and Theses
Epidemiological studies have failed to show any important impact of human immunodeficiency virus (HIV) infection and disease on leprosy, in contrast to the well documented increase in incidence and morbidity with other mycobacteria in these patients, notably Mycobacterium tuberculosis. The early events following exposure and repeated exposure to Mycobacterium leprae (ML) have not still been studied. Previous studies of first inoculations of ML in the skin of rhesus monkeys have indicated delayed recruitment of CD4+ cells and delayed interleukin (IL) 2 secretion in skin inoculation sites in simian immunodeficiency (SIV) positive animals. The development of the secondary immune response against …
Ecology Of Seagrass Fishes And Macroinvertebrates On Guatemala's Atlantic Coast., Alejandro Arrivillaga
Ecology Of Seagrass Fishes And Macroinvertebrates On Guatemala's Atlantic Coast., Alejandro Arrivillaga
LSU Historical Dissertations and Theses
The ecology of fishes and macroinvertebrates inhabiting shallow seagrass beds was studied at Bahia La Graciosa, located in Amatique Bay in the Caribbean coast of Guatemala. The study area included extensive turtle grass, Thalassia testudinum, meadows over muddy substrate, whereas a more exposed shoreline also supported turtle grass meadows over sandy substrates outside the bay. A total of 166 samples were collected across two seasons and habitat types in three sampling trips to the area with a cylindrical drop sampler. Diversity and abundance of fishes and macroinvertebrates inhabiting seagrass and adjacent bare-sand sites were described to assess the relative importance …
Suspended Sediment And Nutrient Flux Dynamics In Fourleague Bay, Louisiana: The Role Of Winter Cold Fronts And Atchafalaya River Discharge., Brian Christopher Perez
Suspended Sediment And Nutrient Flux Dynamics In Fourleague Bay, Louisiana: The Role Of Winter Cold Fronts And Atchafalaya River Discharge., Brian Christopher Perez
LSU Historical Dissertations and Theses
Material concentrations and fluxes in Oyster Bayou, a tidal channel connecting Fourleague Bay, Louisiana and the northern Gulf of Mexico, were sampled every three hours for 3-months, to examine the importance of atmospheric cold fronts and riverine forcing on the functioning of this estuarine system. The Atchafalaya River was the primary source of nitrate+nitrite (NO2+NO3), total nitrogen (TN), and total phosphorus (TP) to the estuary with greater influence associated with northerly post-frontal winds. Riverine influence coupled with wind-forced resuspension events led to the greatest concentrations of total suspended sediment (TSS) and particulate organic carbon (POC). Ammonium (NH4) concentrations were highly …
Molecular Systematics Of The Green Algal Order Trentepohliales (Chlorophyta)., Juan Manuel Lopez-Bautista
Molecular Systematics Of The Green Algal Order Trentepohliales (Chlorophyta)., Juan Manuel Lopez-Bautista
LSU Historical Dissertations and Theses
Molecular, karyological, and nuclear genome quantification data from representatives of the order Trentepohliales (Chlorophyta) were used to infer evolutionary relationships with other green algal classes and orders. Phylogenetic analyses of the nuclear-encoded small subunit ribosomal DNA (18S rDNA) sequences from taxa representing all of the major lineages of green algae consistently indicated that the subaerial Trentepohliales are closely related to Ulvophycean marine green algae, particularly to the siphonous and hemisiphonous orders. The phylogenetic distribution of continuous and discontinuous types of mitochondrial large subunit ribosomal RNAs (mtLSU rRNA) in green algae has been shown to be consistent with phylogenetic relationships previously …
Creation And Characterization Of 25 Kda Outer Membrane Protein (Omp25) Deletion Mutants In Brucella Species., Matthew David Edmonds
Creation And Characterization Of 25 Kda Outer Membrane Protein (Omp25) Deletion Mutants In Brucella Species., Matthew David Edmonds
LSU Historical Dissertations and Theses
The genus Brucella is composed of Gram-negative, facultative intracellular pathogens that impact man and animals. Brucella species express a 25 kDa major outer membrane protein termed Omp25. To determine the role of Omp25 in virulence, mutants were created in Brucella abortus (BA25), Brucella melitensis (BM25), and Brucella ovis (BO25) that contain disruptions in the omp25 gene (Deltaomp25 mutants). In the murine brucellosis model, each Deltaomp25 mutant was attenuated when compared to the virulent parental strain. To assess the ability of the B. abortus and B. melitensis mutants to colonize and induce abortions in the ruminant host, cattle and goats in …
Habitat And Demography Of Understory Trees In Mixed Species Hardwood Forests In Northern Florida, United States Of America., Charles Kwit
Habitat And Demography Of Understory Trees In Mixed Species Hardwood Forests In Northern Florida, United States Of America., Charles Kwit
LSU Historical Dissertations and Theses
Temperate mixed-species hardwood forests of northern Florida, USA, contain a high diversity of understory tree species, some of which have been hypothesized to require disturbance (e.g., hurricanes and/or treefall gaps). Taxus floridana is a rare understory conifer endemic to midslopes of ravines of the Apalachicola River Bluffs, and is found primarily on north-facing slopes. Vegetation sampling in the southern portion of T. floridana's range revealed the presence of an upslope oak-hickory community of suggested recent origin, and higher densities of American beech (Fagus grandifolia ), southern magnolia (Magnolia grandiflora), and evergreen understory trees on north-facing midslopes with T. floridana than …
Pathogenesis Of Bartonella Henselae In The Domestic Cat: Use Of A Pcr-Based Assay For The Detection And Differentiation Of B. Henselae Genotype I And Genotype Ii In Chronically Infected Cats., Alma Faye Roy
LSU Historical Dissertations and Theses
Bartonella henselae is a zoonotic agent in which the domestic cat serves as the natural reservoir, and humans acquire potentially serious infections associated with this microorganism. The purpose of this research is to contribute to the understanding of the pathogenesis of B. henselae in the domestic cat using a molecular approach. Using sequence differences in a portion of the I 6S rRNA gene between B. henselae genotype I, and B. henselae genotype II, a nested polymerase chain reaction (nPCR) was designed and used to investigate various phases of feline bartonellosis. The nPCR detected 3.2 organisms per milliliter of blood which …
Insecticide Resistance And Resistance Mechanisms In The Southern House Mosquito, Culex Quinquefasciatus., Jeffrey Dwayne Stancil
Insecticide Resistance And Resistance Mechanisms In The Southern House Mosquito, Culex Quinquefasciatus., Jeffrey Dwayne Stancil
LSU Historical Dissertations and Theses
Significant resistance to malathion and resmethrin was found in insecticide-treated field populations of adult Culex quinquefasciatus , Say, compared with a laboratory and non-treated field strain. Resistance to both insecticides varied during the active control season and was associated with the frequency of insecticide application. Geographic variations in resistance levels were noted, and significant differences occurred between separate populations within the same mosquito control districts. Four model substrates were assessed for their suitability in detecting elevated esterase activity associated with malathion resistance. Esterase activities towards all substrates were significantly higher in field stains than a laboratory strain. Esterase activities toward …
Visual And Semiochemical Disruption Of Host Finding In Pine Bark Beetles., Brian Lee Strom
Visual And Semiochemical Disruption Of Host Finding In Pine Bark Beetles., Brian Lee Strom
LSU Historical Dissertations and Theses
Pine bark beetles (Coleoptera: Scolytidae) affect ecological and anthropocentric processes in coniferous forests. Certain aggressive species, particularly among the Dendroctonus, cause widespread damage. As forests become increasingly valued for diverse commodities, protection strategies must be developed to meet a wide variety of landowner values. Disruption of the host selection process is one important strategy for managing pine bark beetles. The objectives of this work were: to describe the oleoresin flow and constituency of loblolly pines (Pinus taeda) whose parents escaped mass attack by the southern pine beetle, Dendroctonus frontalis (SPB); to ascertain the utility of altering visual silhouettes to disrupt …
Floral Ontogeny And Phylogeny In Malvaceae., Teresa Shuff Crozier
Floral Ontogeny And Phylogeny In Malvaceae., Teresa Shuff Crozier
LSU Historical Dissertations and Theses
Floral ontogeny in representatives of Malvaceae was compared using scanning electron microscopy. Many aspects of floral development have been resolved by this research, including the presence of a petal-stamen ring meristem in malvaceous taxa. There are several ontogenetic pathways to the formation of this ring meristem; in addition, common petal-stamen mounds are usually present during some stage of development. Stamen proliferation is achieved by partitioning of the ring meristem and furcation of common stamen primordia. Time of initiation overlaps between the corolla and the androecium, and between the androecium and the gynoecium. Helical initiation occurs in the outer organ whorl …
Glucocorticoid Regulation Of The Leptin Receptor Signaling System In The Rat., Abram Madimabe Madiehe
Glucocorticoid Regulation Of The Leptin Receptor Signaling System In The Rat., Abram Madimabe Madiehe
LSU Historical Dissertations and Theses
Obesity, a recognized health problem, is associated with cardiovascular disease, diabetes and hypertension. Removal of adrenal steroids by adrenalectomy (ADX) slows the development of obesity. Leptin decreases food intake through effects initiated by activation of the JAK-STAT pathway. Defects in leptin signaling lead to obesity, which is associated with hyperleptinemia and leptin resistance. In chapter 4, leptin induces phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression and increases glucose production in hepatocytes from lean but not obese Zucker rats. This suggests that hyperleptinemia in obesity causes hyperglycemia. In chapter 5, ADX decreased the levels of PEPCK mRNA, and increased leptin receptor mRNA expression …
Host And Parasite Interactions Among Three Symbionts: Pocket Gophers, Chewing Lice, And Endosymbiotic Bacteria., David Lee Reed
Host And Parasite Interactions Among Three Symbionts: Pocket Gophers, Chewing Lice, And Endosymbiotic Bacteria., David Lee Reed
LSU Historical Dissertations and Theses
This study investigates the patterns of cophylogeny documented between pocket gophers (Rodentia: Geomyidae) and their ectoparasitic chewing lice (Phthiraptera: Trichodectidae). The first two chapters investigate the mechanisms that reinforce cospeciation in this system. Chapter one examines whether mammalian hair diameter is a resource tracked by chewing lice, and thus reinforces the patterns of cospeciation. I found that hair diameter of pocket gophers is correlated with gopher body size and the body size of the ectoparasitic chewing lice. Hair diameter also is correlated with size of the rostral groove, which chewing lice use to grasp hair shafts of pocket gophers. In …
Oxidation -Reduction Chemistry Of Methane And Nitrous Oxide In Soils And An Approach To Minimize Their Emissions From Irrigated Rice Fields., Kewei Yu
LSU Historical Dissertations and Theses
Rice fields are an important source of the greenhouse gases methane (CH 4) and nitrous oxide (N2O). In this dissertation study, experiments were conducted at three levels---in soil suspensions, in soil cores, and under actual field conditions, to investigate the impact of soil redox potential on CH4 and N2O emissions to the atmosphere. Methane and N2O emissions occurred at distinctively different redox conditions in the homogenous soil suspensions. No significant amounts of CH4 was produced when the soil redox potentials were above -150 mV. In the denitrification process, both N2O production and reduction occurred in the soil redox potential range …
Comparative Biology And Ecology Of The Formosan Subterranean Termite, Coptotermes Formosanus Shiraki (Isoptera: Rhinotermitidae) In Louisiana., Huixin Fei
LSU Historical Dissertations and Theses
A laboratory study was conducted to investigate the effects of sibship patterns and different origins of colonies on mate mortality and growth of incipient colonies in the subterranean termite, Coptotermes formosanus Shiraki. Primary reproductives from New Orleans in nonsibling pairs had significantly higher mortality than sibling pairs. The average egg production for sibling and nonsibling pairs showed no overall significance in the first oviposition period, however, the average number of larvae was consistently higher in nonsibling than in sibling-founded colonies from New Orleans. After two years, the average number of eggs or larvae present in nonsibling-founded colonies was significantly higher …
Dna Alkylation And Its Repair In Small Fish Species., Thomas James Vicek
Dna Alkylation And Its Repair In Small Fish Species., Thomas James Vicek
LSU Historical Dissertations and Theses
Mechanisms of DNA alkylation and repair were investigated in 3 small fish species. Following aqueous exposure to either N-methyl- N'-nitro-N-nitrosoguanidine or ethyl methanesulfonate, the hepatic DNA from the western mosquitofish, Gambusia affinis, was analyzed for alkyl-DNA adducts via high performance liquid chromatography - mass spectrometry/mass spectrometry. Although potential tissue detection limits ranged from 14--101 fmoles of alkyl adducts/mg tissue, no alkyl-DNA adducts were detected in the exposed tissues. To assess the potential repair of alkyl-DNA adducts in 2 other small fish species, alkyltransferase activities within hepatic protein extracts of the Gulf killifish, Fundulus grandis, and Gambusia affinis were determined using …
Biometrical Models For Predicting Future Performance In Plant Breeding., Monica Graciela Balzarini
Biometrical Models For Predicting Future Performance In Plant Breeding., Monica Graciela Balzarini
LSU Historical Dissertations and Theses
The plant breeding process begins with the selection of parents and crosses. Promising progeny from these crosses progress through a series of selection stages that typically culminate in multi-environment trials. I evaluated best linear unbiased predictors (BLUP), other predictors and prediction models at the initial (cross prediction), early replicated testing and late (multi-location) stages of a sugarcane breeding selection cycle. Model and predictor accuracy was assessed in the first two stages by using cross-validation procedures. I compared statistical models of progeny test data in their ability to predict the cross performance of untested sugarcane crosses. Random parental effect predictors and …
Systematics Of The Polymorphic North American Rat Snake (Elaphe Obsoleta)., Frank Thomas Burbrink
Systematics Of The Polymorphic North American Rat Snake (Elaphe Obsoleta)., Frank Thomas Burbrink
LSU Historical Dissertations and Theses
The North American rat snake (Elaphe obsoleta) complex is composed of seven uniquely colored subspecies of E. obsoleta and the sister species E. bairdi. Maximum parsimony (MP) and maximum likelihood (ML) analysis of two mitochondrial DNA genes from 73 E. obsoleta and E. bairdi, produced well-supported trees that do not conform to the currently accepted subspecies. Both ML and MP trees were significantly shorter than the trees in which each subspecies was constrained to be monophyletic. The subspecies of E. obsoleta do not represent genetic lineages. Instead, molecular evidence revealed the existence of four well-supported mtDNA clades confined to particular …