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Dispersion And Physiological Ecology Of Mosquito Adults In Louisiana Ricelands., Alan Richard Holck

LSU Historical Dissertations and Theses

A sampling technique for estimating the size of adult mosquito populations in vegetation was developed. Regression analysis was used to obtain absolute density estimates from sweep net. Diurnal population size estimates of Louisiana riceland mosquitoes were made on a 35.6-square km site 5 km south of Kaplan, LA. Four mosquito species were present: Psorophora columbiae, Anopheles quadrimaculatus, An. crucians and Culex salinarius. Mosquito species were highly stratified in their distribution. Psorophora columbiae was primarily observed in pastures with livestock and in rice fields. Both Anophelines were found only in structures. Culex salinarius did not exhibit habitat preference. Anopheles quadrimaculatus exhibited …

Molecular Biological Studies On The Degradation Of Diphenyl Ethers By Bacteria., Hung-Ming James Liaw

LSU Historical Dissertations and Theses

Microbial degradation of diphenyl ethers was studied utilizing several different approaches. The first approach was to isolate mutants from a ligninolytic Erwinia sp. by conventional mutagenesis and selection. A copper-resistant mutant, designated as Erwinia sp. CU3614, was isolated and characterized to be capable of degrading diphenyl ethers as well as one dibenzo-p-dioxin in the presence of copper ions. Isolation of Tn5 transposon-induced mutants of Erwinia sp. CU3614, which lost degradation ability, demonstrated that in all probability a copper-associated activity in the biotransformation of aromatic ethers was involved. In order to study the degradation at the molecular biological level, a 2.1 …

Ecological Consequences Of Variation In Pollinator Availability: Ocotillo, Carpenter Bees, And Hummingbirds In Two Deserts., Peter Evans Scott

LSU Historical Dissertations and Theses

I studied the pollination ecology of a widespread desert shrub, ocotillo (Fouquieria splendens), and some of the consequences of geographic variation in availability of pollinators. I studied ocotillo in the Chihuahuan Desert of western Texas (Big Bend National Park) for three flowering seasons, and in the Sonoran Desert of southern California (Anza-Borrego Desert State Park) for parts of two flowering seasons. In both areas, ocotillo flowers profusely for one month each year, and requires outcross pollination to mature more than 5% of its potential seed crop. In Texas, carpenter bees (Xylocopa californica arizonensis) and their nest plants (species of Agave, …

Avian Influenza Viruses In Coastal Louisiana Waterfowl: Host And Environmental Factors Affecting Prevalence And Viral Persistence., David Edward Stallknecht

LSU Historical Dissertations and Theses

Cloacal and tracheal swabs were collected from 1,389 hunter-killed ducks in Cameron Parish, Louisiana during the 1986 and 1987 waterfowl seasons. These included 605 blue-winged teal (Anas discors), 75 mottled ducks (A. fulvigula), 375 gadwalls (A. strepera) and 334 green-winged teal (A. crecca). Twenty-eight avian influenza viruses (AIVs) were isolated. Prevalence estimates of AIV in ducks during September, November and December/January were 3.1%, 2.1%, and 0.4%, respectively. Differences in prevalence were detected by season ($P$ =.044) and age class ($P$ =.036). Two isolations from resident mottled ducks indicate local transmission of AIV on these wintering areas. Much subtype diversity was …

Phosphatidylethanolamine Synthesis By A Base Exchange Reaction In Castor Bean Endosperm., Sungho Shin

LSU Historical Dissertations and Theses

An ethanolamine base exchange enzyme has been assayed in the endoplasmic reticulum (ER) of castor bean (Ricinus communis L. var. Hale) endosperm. The activity was maximal at ethanolamine concentrations of 30 uM in the presence of 2 mM CaCl$\sb2$. The optimum pH was 7.8 using HEPES buffer. Under these conditions, the enzyme had a maximum enzyme velocity of approximately 0.3 nmol h$\sp{-1}$ mg$\sp{-1}$ protein and an apparent Km of 5.0 uM for ethanolamine. A maximum velocity of approximately 1.7 nmol h$\sp{-1}$ mg$\sp{-1}$ protein was obtained under similar conditions with L-serine at about 400 uM in a serine base exchange reaction. …

The Evolution Of Igg And Igm Antibodies To Antigens Of Mycobacterium Leprae In Experimentally Inoculated Armadillos., Abdul Reza Vadiee

LSU Historical Dissertations and Theses

The nine-banded armadillo (Dasypus novencinctus linn.) is highly susceptible to infection with M. leprae and has become an important animal model in the study of leprosy. In an attempt to define the major immunogens of M. leprae and the isotypic antibody response to these molecules during infection, the IgG and IgM antibody responses of experimentally-infected armadillos to the sonicated M. leprae, supernatant fraction of sonicated M. leprae, lipoarabinomannan derived from M. tuberculosis, and phenolic glycoliopid-I was analyzed using immunoblot and ELISA. Antibodies to the specific epitope (defined by monoclonal antibody IIIE9) on the 65-kDa protein of M. leprae were analyzed …

Studies On Trypanosoma Cruzi Isolates From Louisiana Mammals With Particular Reference To Infectivity To Dogs., Stephen Charles Barr

LSU Historical Dissertations and Theses

This dissertation describes studies on three Trypanosoma cruzi isolates from Louisiana mammals with particular reference to infectivity to dogs. Isolates from an opossum (Tc-O) and armadillo (Tc-A) were obtained during a blood culture survey of these animal populations in Louisiana. Prevalence of T. cruzi were 37.5% and 1% in opossums and armadillos respectively. Further, 48% opossums had myocarditis suggestive of T. cruzi infection. Rural dogs with known contact with T. cruzi hosts, housed rural dogs, urban animal shelter dogs and household pets showed 4.7, 0, 2.3 and 0% serological prevalence to T. cruzi respectively. Tc-O and Tc-A (wild isolates) displayed …

Floral Ontogeny Of Mimosoid Legumes., Jose Israel Ramirez-Domenech

LSU Historical Dissertations and Theses

Comparative floral ontogeny in mimosoid legumes was analyzed among representative genera in three major tribes Mimoseae, Acacieae and Ingeae. Details on floral and inflorescence ontogeny in one mimosoid species is described and illustrated for Mimosa strigillosa Torr. & Gray. Three features studied developmentally include: variation in number of parts, patterns of arrangement and inflorescence architecture. Suppression occurs along inflorescences that develop synchronously, when basal flowers are retarded. Tetramerous flowers are considered a reduction or suppression from basic pentamerous flower. Divergent patterns in order of sepal initiation and stamen initiation and proliferation are found during early ontogeny. Four patterns found in …

Characterization Of The Transcriptional Properties Of Equine Infectious Anemia Virus., Siyamak Rasty

LSU Historical Dissertations and Theses

The transcriptional properties of equine infectious anemia virus were examined in two distinct equine cell lines in which the virus establishes either a persistent or a cytopathic infection. Northern hybridization analyses were performed to determine the number, sizes, and relative levels of the EIAV transcripts encoded during persistent or cytopathic infections. Three species of viral mRNA were detected in infected cells: an 8.2-kb full-length genomic mRNA, a 3.5-kb single-spliced mRNA, and a low abundance 1.5-kb mRNA, presumably formed by a double-splicing event of the full-length mRNA. Analysis of the levels of EIAV-specific RNA's present during persistent and cytopathic infections has …

Age And Growth Of Red Drum, Sciaenops Ocellatus, And Black Drum, Pogonias Cromis, In The Northern Gulf Of Mexico., Daniel William Beckman

LSU Historical Dissertations and Theses

The objectives of this study were to obtain age estimates and describe growth for the two sciaenid fish species, red drum Sciaenops ocellatus and black drum Pogonias cromis, in the northern Gulf of Mexico. Age estimates were made using annulus counts in transverse sections of otoliths (inner ear bones). Aging techniques were validated for juvenile red drum by imparting oxytetracycline into otoliths as a time marker. Recaptures validated that annuli were deposited in otoliths yearly up to 2.5 years age, with the first annulus formed in the second winter at 1-1.5 years age. Age estimates for remaining age classes of …

Feeding And Foraging Behaviors Of Subterranean Termites (Isoptera:Rhinotermitidae)., Keith Scott Delaplane

LSU Historical Dissertations and Theses

Six studies were done on feeding and foraging behaviors of three species of subterranean termites, Coptotermes formosanus Shiraki, Reticulitermes flavipes (Kollar), and R. virginicus (Banks) (Isoptera: Rhinotermitidae). When presented with four equal wood blocks, C. formosanus did not forage randomly but concentrated on a few preferred blocks. When R. flavipes and C. formosanus were each placed in foraging arenas with linear, successive wood blocks, C. formosanus consumed a greater percentage dry mass of a wood block before moving to the next block (10.3%) than did R. flavipes (4.2%). Groups of C. formosanus were offered wood blocks that differed in initial …

Molecular Characterization Of Fall Armyworm Mitochondrial-Dna (Spodoptera Frugiperda (J. E. Smith);)., Li Dao Ke

LSU Historical Dissertations and Theses

Chapter I. Mitochondrial DNA (mtDNA) was isolated, purified from pooled samples of fall armyworm (FAW), Spodoptera frugiperda, and characterized. The yield of mtDNA from adults ranged from 45 to 114 ng per moth. Entire mtDNA from adult FAW showed 1 to 3 electrophoretic bands when electrophoresed on agarose gels. When digested with SalI or XhoI restriction endonucleases, all DNA forms co-migrated as single bands with the same mobility. XbaI cleaved the mtDNA into three fragments of 8083 $\pm$ 524, 6179 $\pm$ 430, and 1990 $\pm$ 140 base pairs (bp). The FAW mitochondrial genome size was calculated to be 16,253 $\pm$ …

Vegetation Of The Coniferous-Deciduous Forest Overlap Region Along The Niobrara River Valley Of North-Central Nebraska., Carol Sue Crosby

Student Work

Introduction: The Niobrara River Valley of north central Nebraska is recognized as an area in which elements of the Rocky Mountain (coniferous), Boreal, and Eastern Deciduous forests meet. These elements occur primarily along river bluffs in an area surrounded by grasslands (Bessey 1887, Pound and Clements 1900, Tolstead 1947, Nixon 1967, Kaul 1975). In this region many species of plants and animals reach their distributional limits (Tolstead 1942). Diverse topography, north/south slope microclimates, soil, hydrology and geologic history have contributed to creating this biological crossroads amidst a chiefly grassland climate.

Age-Related Changes In The Cardiorespiratory Response To Exercise And Physical Training, Joan Elizabeth Himann

Digitized Theses

The age-related decrease in cardiorespiratory fitness in the elderly has been attributed to the aging process and to reduced activity levels. The cardiorespiratory response to exercise across the ages (19-102y) was examined in order to describe the age-related rate of decline of cardiovascular function, study the effect of an exercise training program on this decline and discover whether the control mechanisms of the integrated response to exercise are affected by aging.;Both men and women showed a curvilinear decrease in self-selected walking speed with age (19-102y). In the older age range ({dollar}>{dollar}60y), minimal oxygen consumption (VO{dollar}\sb2{dollar}max) was predicted best by …

The Role Of The Subfornical Organ In The Control Of Cardiovascular Function And Fluid Homeostasis, Michael Bentov Gutman

Digitized Theses

Increased circulating levels of angiotensin II (ANG II) are known to act at the subfornical organ (SFO) to produce increases in arterial pressure, drinking and secretion of arginine vasopressin (AVP). These studies were done to investigate whether the SFO projections to the nucleus medianus (NM), supraoptic nucleus (SON) and paraventricular nucleus of the hypothalamus (PVH) mediate these responses.;Experiments done in urethane anesthetized rats showed that the SFO was the most sensitive area in the region for eliciting cardiovascular responses consisting of short and long latency increases in arterial pressure, when electrically stimulated or microinjected with L-glutamate. Ganglionic blockade abolished the …

Studies On The Regulation Of Oocyte Maturation In The Rat With Assessment By In Vitro Fertilization And Fetal Development, Barbara Catharine Vanderhyden

Digitized Theses

The purposes of this study were: (1) to develop techniques for in vitro maturation of rat oocytes which would permit fertilization and normal embryonic development, and (2) to investigate the role of somatic cell-germ cell interactions, and hormonal influences, in the physiological regulation of oocyte maturation as assessed by these techniques.;Procedures for in vitro fertilization (IVF) of rat oocytes were developed and validated by transferring the resulting embryos to recipient females. Although embryos resulting from IVF were less successful in establishing pregnancy than appropriate in vivo fertilized controls, optimization of culture and transfer techniques enabled minimization of embyronic losses and …

Genetic Control Of Immune Responsiveness To The Avian Coccidium Eimeria Tenella, Robert Andrew Clare

Doctoral Dissertations

Specific inbred lines of chickens expressing different major histocompatibility (B) complex haplotypes were studied for their immunogenetic response to the avian coccidium Eimeria tenella and genetically-engineered antigens cloned from this parasite species. The relative influence of the B-F vs. B-G chromosomal regions on innnate resistance and immunity to E. tenella was studied among six B-F/B-G recombinant hosts. F$\sb1$ chicks of similar genotypes, $B\sp{\rm R3}$ and $B\sp{\rm R4} (B\sp{\rm F2-G23}B\sp{17}$), gained significantly more weight than those with $B\sp{\rm R1}(B\sp{\rm F24-G23}B\sp{17})$ and $B\sp{\rm R5} (B\sp{\rm F21-G19}B\sp{17})$ following exposure to a single high dose of 25,000 oocysts, although no differences in cecal lesion …

Investigations Into Bovine Luteolytic Mechanisms Utilizing A Long-Term Cell Culture System, Shari Jean Litch

Doctoral Dissertations

Luteal regression in the cow occurs every cycle in which pregnancy does not occur. The agent which induces luteolysis is a uterine prostaglandin, PGF$\sb{2\alpha}$, although the mechanism of its action remains unknown. The purpose of this study was to investigate the mode of action of PGF$\sb{2\alpha}$ in a long-term, serum-free culture system of bovine luteal cells. Experiment I investigated the influence of LH and PGF$\sb{2\alpha}$ on 3$\beta$-HSD presence in cultured luteal cells. Total numbers of cells dropped slightly throughout the 8 day culture. Numbers of 3$\beta$-positive cells also dropped in all treatment groups. 3$\beta$-HSD was best maintained in the presence …

Peptide And Amine Actions On The Neurogenic Limulus Heart: Biochemical Mechanisms Of Modulation, James Richard Groome

Doctoral Dissertations

The biochemical basis underlying the chronotropic and inotropic effects of peptides and amines on the neurogenic heart of the horseshoe crab, Limulus polyphemus, was investigated. This study focused on the role of cyclic nucleotide and phosphatidylinostiol metabolism in specific actions of amines and peptides endogenous to the Limulus nervous system. Biochemical and electrophysiological analyses of amine and peptide actions on specific cellular targets within the neurogenic heart network were performed to characterize the intracellular mechanisms responsible for the excitatory effects of these neuromodulators.

Octopamine and the catecholamines dopamine, norepinephrine and epinephrine utilize the second messenger cyclic AMP at multiple cellular …

Regulation Of Zooplankton Vertical Migrations By Light, Food, And Fish, Elizabeth Susan Mclean

Doctoral Dissertations

The regulation of zooplankton vertical migration has been attributed to the physical environment, and, more recently, to biological factors. This study evaluated the influence of light, food and fish on vertical migration. Laboratory experiments quantified changes in vertical migrations of Daphnia pulex in tall columns in response to short term changes in food concentration and the presence of a fish, under a wide range of natural light conditions.

A stimulus-threshold model predicted the time of the start of migration from a threshold rate of relative light intensity change. Hypotheses that migrations follow isopleths of light intensity, and that velocity of …

Rowcover Modification Of Carbon And Mineral Nutrient Partitioning In Strawberry (Fragaria Ananassa, Duch), Karen Lynn Brownlee Gast

Doctoral Dissertations

In cool temperature climates where plant growth may be limited by short growing seasons and low temperature stress rowcovers are being used to increase production of fruit and vegetable crops. Two field experiments were conducted to investigate how floating rowcovers applied during autumn, winter and spring affect plant growth and development. The first experiment, 1985-86, examined mineral nutrient and biomass partitioning in a short-day cultivar, 'Sparkle', and a day-neutral cultivar, 'Fern', in rowcovered and nonrowcovered plants in autumn. The second experiment, 1986-87 examined carbon, nitrogen and biomass partitioning over time in autumn and in spring and development of yield components …

Characterization And Application Of Monoclonal Antibody And Bovine Neutrophil Reactivity To Pasteurella Haemolytica Antigens., Frank William Austin

LSU Historical Dissertations and Theses

Monoclonal antibodies (McAbs) were prepared against Pasteurella haemolytica serotype 1 (Ph-1) capsular material to identify, quantitate and purify antigens. McAbs were selected by ELISA and characterized according to their isotype, cross-reactivity with P. haemolytica and P. multocida serotypes in ELISA, antigen formalin sensitivity and ability to cause bacterial agglutination. Four groups of McAbs were established each recognizing a different epitope. Various P. haemolytica and P. multocida serotypes were found to share several epitopes demonstrating their antigenic relatedness. A colorimetric assay, based on tetrazolium dye reduction by bovine neutrophils, was adapted for the measurement and characterization of Ph-1 cytotoxin activity. Using …

Multisensory Discrimination And Representational Memory Deficits In Post-Thiamine Deficient Rats: Testing An Animal Model Of Human Wernicke-Korsakoff's Disease, Russell Laine Knoth

Doctoral Dissertations

The most common cause of diencephaic amnesia in human is Wernicke-Korsakoff's disease, the psychological component of a nutritional polyneuropathy associated with chronic alcoholism. It has long been understood that Wernicke-Korsakoff's disease is caused by thiamine deficiency. The symptoms of the acute Wernicke's phase of this disease include disorientation, ataxia, and ocular nystagmus, and if left untreated, death. If treated with thiamine, the acute symptoms quickly subside. However, following recovery from the acute Wernicke's symptoms, many patients evidence the symptoms of the chronic Korsakoff's syndrome, which includes both global anterograde and retrograde memory deficits and personality changes. The memory deficits observed …

Epidemiology Of Campylobacter Jejuni., Kanagasundaram Yogasundram

LSU Historical Dissertations and Theses

A study was conducted to determine the prevalence of Campylobacter jejuni in various avian species and humans. Cloacal swabs derived from birds submitted to the Louisiana Veterinary Medical Diagnostic Laboratory for necropsy examination during the period February 1987 through July 1988 were routinely cultured for C. jejuni using Butzler's selective medium. Campylobacter jejuni was isolated from 10.1% of the cases examined. The isolation rate was 25.2% in Galliformes, 12.9% in Anseriformes, 8.3% in Columbiformes, 7.7% in Falconiformes, and 0.6% in Psittaciformes. None of the other orders of birds examined yielded C. jejuni. Prevalence data demonstrated that Galliformes are important reservoirs …

Antigenic Analysis Of Equine Infectious Anemia Virus Using Monoclonal Antibodies., Khalid Abdullah Hussain

LSU Historical Dissertations and Theses

Monoclonal antibodies (MCAbs) produced against the prototype cell-adapted Wyoming strain of equine infectious anemia virus (EIAV), a lentivirus, were studied for reactivity with the homologous prototype and 16 heterologous isolates. Eighteen hybridomas producing MCAbs were isolated. Western blot (immunoblot) analyses indicated that 10 were specific for the major envelope glycoprotein (gp90) and 8 for the transmembrane glycoprotein (gp45). Four MCAbs specific to epitopes of gp90 neutralized prototype EIAV infectivity. These neutralizing MCAbs apparently reacted with variable regions of the envelope gp90, as evidenced by their unique reactivity with the panel of isolates, suggesting recognition of at least three different neutralization …

A Study On The Toxicity Of Sesbania Drummondii In Chickens And Rats., Marie-Lorraine Marceau-Day

LSU Historical Dissertations and Theses

A comparative study of two susceptible species, the chicken and the rat, to crude and partially purified extracts of the plant Sesbania drummondii was undertaken. Partial physical and chemical characterization of crude sesbania extracts has been accomplished including temperature and pH stability, molecular weight fractionation and high pressure liquid chromatography and thin layer chromatography retention times. The toxicity of these different fractions could be differentiated with respect to weight loss, mortality, morbidity, serum protein changes and effect on PChE (Pseudocholinesterase) activities. The results indicated that more than one toxin exists in crude extracts of this plant. The pathophysiological findings could …

Physiological And Behavioral Responses To Aerial Exposure In The Asian Clam, Corbicula Fluminea (Muller)., Roger Anthony Byrne

LSU Historical Dissertations and Theses

Aerially exposed, bivalve molluscs face opposing problems of preventing water loss, and maintaining metabolism. Because of the unpredictability of emersion duration, most freshwater bivalve families are capable of extensive emersion tolerance. Corbicula fluminea (Muller) is a relatively recent invader of freshwater and shares many physiological features with its estuarine ancestors. It might be expected to be intermediate in its emersion responses between those of more ancient freshwater forms, and those of estuarine clams. In air, C. fluminea displayed ventilatory behaviors which were associated with high rates of aerial O$\sb2$ uptake and CO$\sb2$ release. Normoxically exposed clams had bursts of heat …

The Effects Of Temperature Stress On The Bovine Pituitary-Adrenal-Ovarian Axis: An In-Vitro Study., Terry Davis

LSU Historical Dissertations and Theses

The effect of temperature stress on profiles of LH and FSH from pituitary cells; aldosterone, progesterone, cortisol and corticosterone from adrenocortical cells; and estradiol and progesterone from granulosa cells were evaluated using bovine anterior pituitary, adrenocortical and granulosa cells in primary cultures. Cells were grown to confluency in a 37$\sp\circ$C humidified incubator containing 95% O$\sb2$ and 5% CO$\sb2$. Upon reaching confluency, half of the wells were assigned to 40$\sp\circ$C incubation temperature while the other half remained at 37$\sp\circ$C. The 37$\sp\circ$C temperature represented control conditions whereas 40$\sp\circ$C represented heat stress. Various biological substances, that have been reported to alter hormone production, …

Biochemical And Physiological Mechanisms Involved In Insecticide Toxicity And Host Plant Resistance To The Soybean Looper, Pseudoplusia Includens (Walker)., Randy Lynn Rose

LSU Historical Dissertations and Theses

Permethrin, fenvalerate, methomyl, acephate and methyl parathion were bioassayed on larvae of the soybean looper, Pseudoplusia includens (Walker) and the velvetbean caterpillar, Anticarsia gemmatalis (Hubner) fed on susceptible (Bragg) versus resistant (PI 227687) soybean, Glycine max (L.) Merr., cultivars. Soybean loopers reared on resistant leaves were significantly more susceptible to acephate (2-fold) than when reared on susceptible leaves. Velvetbean caterpillars fed resistant leaves were more susceptible to both fenvalerate (1.5-fold) and acephate (1.6-fold) than when fed susceptible leaves. Differences in toxicity of other insecticides due to host plant were not observed. Midgut homogenates from last instar soybean loopers reared on …

The Dextranase Of Lipomyces Starkeyi And Its Use In Sugar Cane Processing., David William Koenig

LSU Historical Dissertations and Theses

Dextranase is an enzyme which destroys dextran, a contaminant in sugar and a main constituent of dental plaque. Dextranase utilization can solve a major economic problem in the sugar industry, and in dental preparations it can keep teeth essentially free of plaque. The dextranase from the yeast Lipomyces starkeyi was investigated because this organism has been used in food related processes. This attribute should allow for Food and Drug Administration (FDA) approval for use of a Lipomyces dextranase. None of the existing commercial dextranase preparations have FDA approval. L. starkeyi was found to produce maximum amounts of dextranase when grown …