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Melanin Production By The Black Yeast Phaeococcomyces Sp, Michael John Butler Jan 1987

Melanin Production By The Black Yeast Phaeococcomyces Sp, Michael John Butler

Digitized Theses

A black yeast isolated from oak bark was identified as a species of Phaeococcomyces. The yeast produced black pigment constitutively which was identified as a pentaketide melanin, since its production was inhibited by the systemic fungicide tricyclazole. The black yeast melanin was produced as granules with a diameter of ca. 30 nm. Three types of pigmentation mutant were produced; albino mutants, which did not produce melanin, diffusion mutants which were not melanized, and excreted 2-hydroxy-juglone and flaviolin in culture media, and cross feeder mutants which were not melanized and excreted scytalone, a component of the main pentaketide pathway, into culture …

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Seasonal Reproduction And Group Dynamics Of Bushy-Tailed Woodrats, Neotoma Cinerea, Graham John Hickling Jan 1987

Seasonal Reproduction And Group Dynamics Of Bushy-Tailed Woodrats, Neotoma Cinerea, Graham John Hickling

Digitized Theses

It has been proposed that bushy-tailed woodrats (Neotoma cinerea) exhibit a harem-polygynous social system (Escherich 1981). I monitored 16 groups of N. cinerea in rocky habitat in the Kananaskis Valley, Alberta, from 1984 through 1986 to determine whether reproduction, growth, group size, and group sex ratio of this species were proximately limited by food abundance. Supplemental food was supplied to 8 groups through 2 successive breeding seasons, and the fed and unmanipulated groups were monitored using mark-recapture techniques. N. cinerea first bred as yearlings, with females producing 1 or 2 litters each season. Food addition resulted in early breeding (p …

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The Effect Of Chilling Temperatures On Aspects Of Porphyrin Metabolism In Leaves Of Seedlings Of Maize (Zea Mays L), Robert Russell Hodgins Jan 1987

The Effect Of Chilling Temperatures On Aspects Of Porphyrin Metabolism In Leaves Of Seedlings Of Maize (Zea Mays L), Robert Russell Hodgins

Digitized Theses

The effect of chilling temperatures on porphyrin biosynthesis was studied in maize (Zea mays, L.). The results were consistent with the hypothesis that there are at least 3 temperature sensitive sites that compromise the accumulation of chlorophyll. Week old 28{dollar}\sp\circ{dollar}C light grown seedlings synthesized negligible amounts of chlorophyll when exposed to 12{dollar}\sp\circ{dollar}C for a subsequent 6 d. The effects were reversible in that plants returned to 28{dollar}\sp\circ{dollar}C had the chlorophyll content restored to control levels. The results were not consistent with a low temperature mediated decrease of carotenoid content, depletion of chlorophyll per chloroplast, accelerated senescence, or a dessication mediated …

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Polysome Metabolism In Winter Rye (Secale Cereale Cv Puma), Andre Laroche Jan 1987

Polysome Metabolism In Winter Rye (Secale Cereale Cv Puma), Andre Laroche

Digitized Theses

The effect of growth at low temperature on polysome metabolism in winter rye (Secale cereale cv Puma) has been investigated. A method for isolation of highly polymerized polysomes from mature leaf tissues has been developed. The degree of intactness of isolated polysomes was monitored by two independent but complementary methods: size class distribution on sucrose gradients and in vitro translation. The composition of the optimal polysome isolation buffer for mature rye leaves is similar for leaves grown at low (5{dollar}\sp\circ{dollar}) or high (20{dollar}\sp\circ{dollar}) temperature but different from that reported for young tobacco and pea leaves. The quantity of polysomes (per …

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The Psychosocial Characteristics Of Alcoholics In Treatment Who Were Arrested For Driving While Impaired, Scott Arthur Macdonald Jan 1987

The Psychosocial Characteristics Of Alcoholics In Treatment Who Were Arrested For Driving While Impaired, Scott Arthur Macdonald

Digitized Theses

The purpose of this study was to explore the relationship between various psychosocial characteristics and Driving While Impaired (DWI) arrests, within a sample of male alcoholics in treatment. Four main groups of variables were studied: socio-demographic characteristics, drinking characteristics, driving characteristics and psychosocial characteristics. People were subdivided into three groups according to their number of DWI arrests in the previous ten years, as determined by self-reports and official driving records: Group 0 had zero DWI arrests, Group 1 had one DWI arrest, and Group 2 had multiple DWI arrests. Two hundred and fifty-eight people completed the self-administered questionnaire.;The results of …

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Hemolymph Proteins: Origin And Developmental Changes In The Last Larval Instar Of Calpodes Ethlius (Lepidoptera: Hesperiidae), Subba Reddy Palli Jan 1987

Hemolymph Proteins: Origin And Developmental Changes In The Last Larval Instar Of Calpodes Ethlius (Lepidoptera: Hesperiidae), Subba Reddy Palli

Digitized Theses

Sheets of dorsal abdominal integument, ligated tubes of midgut, sheets of fat body and suspended hemocytes from mid fifth instar larvae of Calpodes ethlius (Lepidoptera: Hesperiidae) were incubated in artificial hemolymph in the presence of ({dollar}\sp{lcub}35{rcub}{dollar}S) methionine to investigate protein synthesis and secretion. Epidermis secretes at least 13 polypeptides basally and 15 apically. Four basally secreted polypeptides were identified in the hemolymph labelled in vivo. Midgut secretes at least eight polypeptides basally and seven apically. Two basally secreted polypeptides were similar to those in the hemolymph. Fat body releases more than 14 polypeptides into the incubation medium and 12 of …

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Influence Of Biogenic Amines On Bovine Luteal Steroidogenesis, Paul Jeffrey Battista Jan 1987

Influence Of Biogenic Amines On Bovine Luteal Steroidogenesis, Paul Jeffrey Battista

Doctoral Dissertations

To investigate the role of catecholamines and biogenic amines in the control of bovine luteal steroidogenesis, studies were conducted utilizing collagenase-dispersed luteal cells in a short-term incubation system. Studies designed to assess the role of catecholamines showed that the stimulatory response to the primary catecholamines norepinephrine and epinephrine was mediated by both $\beta\sb{1}$- and $\beta\sb{2}$- adrenergic receptors. The alternative pathway catecholamines octopamine, synephrine and deoxyepinephrine enhanced basal progesterone production, and this response was mediated by $\beta$-adrenergic receptors. Analysis of luteal tissue using high performance liquid chromatography showed nondetectable levels of norepinephrine and epinephrine. The in vivo administration of norepinephrine and …

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Community Ecology Of Chilean Sandy Beaches, Eduardo Jaramillo Jan 1987

Community Ecology Of Chilean Sandy Beaches, Eduardo Jaramillo

Doctoral Dissertations

Monthly abundances and life history traits of peracarid species (Orchestoidea and Excirolana), and the anomurid crab Emerita analoga were studied during May, 1978 to April, 1980 in an exposed sandy beach of southern Chile (Mehuin Beach, Bahia de Maiquillahue). Beach characteristics differed significantly during these years; i.e. more sand erosion and coarser sand occurred during the first year. The lowest abundances of the total macroinfauna (46-111 ind ${\rm m}\sp{-2})$ occurred during winter 1978, while the highest abundances (896-1251 ind ${\rm m}\sp{-2})$ occurred during winter 1979. The low abundances were a result of severe erosion of the habitat rather than just …

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Parasites Of The Yellowtail Flounder (Limanda Ferruginea, Storer, 1839) From The Western North Atlantic, Salvatore Anthony Testaverde Jan 1987

Parasites Of The Yellowtail Flounder (Limanda Ferruginea, Storer, 1839) From The Western North Atlantic, Salvatore Anthony Testaverde

Doctoral Dissertations

A study was conducted of parasites from the yellowtail flounder, Limanda ferruginea (Storer, 1839) taken from the western North Atlantic, United States. Monthly studies, from the Cape Ann, Massachusetts area, April 1977 to 1979, were initiated to determine prevalence, mean intensity, and range of parasites in relation to host and environmental factors. A second study was conducted to determine parasite-mix between the Cape Cod and the Georges Bank subareas, including preliminary findings from the southern New England and the Middle Atlantic subareas. From 40 previously reported parasites, including adults, metacercariae, plerocercoids, and juvenile forms, a total of 15 species of …

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Microaerophilic Physiology Of Aquaspirillum Magnetotacticum, Kevin Allen Short Jan 1987

Microaerophilic Physiology Of Aquaspirillum Magnetotacticum, Kevin Allen Short

Doctoral Dissertations

Little is known concerning the physiology of obligate microaerophiles. This thesis describes research aimed at furthering our understanding of the obligately microaerophilic nature of the magnetic diazotrophic denitrifier, Aquaspirillum magnetotacticum. Included are studies of iron respiration-driven proton translocation, of microaerobic denitrification and associated NO$\sbsp{2}{-}$ toxicity, and of expression and cellular location of O$\sb2$ detoxifying enzymes in this organism.

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Cerebroprotective Activity Of U-50488h: Relationship To Interactions With Excitatory Amino Acids And Calcium., Marlene Camacho Ochoa Jan 1987

Cerebroprotective Activity Of U-50488h: Relationship To Interactions With Excitatory Amino Acids And Calcium., Marlene Camacho Ochoa

LSU Historical Dissertations and Theses

The mechanism underlying the anticonvulsant and cerebroprotective activity of U-50488H was evaluated using $\sp{45}$Ca$\sp{++}$ uptake in rat Ficoll purified synaptosomes, ($\sp3$H)-2-deoxyglucose uptake in selected mouse brain regions, ($\sp3$H)kainic acid binding to mouse forebrain synaptic membranes and incidence of KA-induced lesions in the CA3 region of the mouse hippocampus. U-50488H causes reduction in K$\sp+$-evoked $\sp{45}$Ca$\sp{++}$ uptake. These effects are comparable to those of the calcium channel blockers verapamil and nifedipine and seem to be related to calcium dependent mechanisms. Changes in saturability, specificity and dissociation constant values of kainic acid receptor binding were demonstrated in the presence of U-50488H at concentrations …

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Dimethylnitrosamine - Induced Neoplasms In F344 Male Rats With Various Manipulations Of The Mixed-Function-Oxidase System: Macroscopic, Microscopic, Ultrastructural, And Immunocytochemical Evaluation., John Michael Gliatto Jan 1987

Dimethylnitrosamine - Induced Neoplasms In F344 Male Rats With Various Manipulations Of The Mixed-Function-Oxidase System: Macroscopic, Microscopic, Ultrastructural, And Immunocytochemical Evaluation., John Michael Gliatto

LSU Historical Dissertations and Theses

Aminopyrine and nitrite were administered to male F344 rats at concentrations of 1 mg each per ml drinking water as precursors of dimethylnitrosamine (DMN). Rats were divided into groups based on manipulations of the mixed-function-oxidase (MFO) system including: partial hepatectomy, subcutaneous injections of aminoacetonitrile (AAN), phenobarbital (plus 1.75% ethanol) and 1.75% ethanol. Rats were killed at 4 weeks, 12 weeks, 24 weeks, and 36 weeks following initiation of the carcinogenic regimen. DMN-induced neoplasms occurred in the liver, kidneys, and lungs. The number and types of tumors, as well as the target organ affected depended on the particular MFO system manipulation. …

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Somaclonal Variation In Hibiscus Acetosella Welw. Ex Hiern: Altered Fertility And Floral Ontogeny., James Robert Ault Jan 1987

Somaclonal Variation In Hibiscus Acetosella Welw. Ex Hiern: Altered Fertility And Floral Ontogeny., James Robert Ault

LSU Historical Dissertations and Theses

A study was undertaken to examine fecundity and floral ontogeny in wild type (WT) and tissue culture-derived (TC) plants of Hibiscus acetosella Welw. ex Hiern. Twenty-eight plants regenerated in vitro from somatic embryos were outplanted and established in the greenhouse, as were three WT plants from seed. The TC and WT plants were self-pollinated. Nine of the TC plants were self-fertile but exhibited a reduction in fruit set and seed set when compared to WT. Days to maturity for fertile fruit varied significantly among TC plants. There was no correlation of days to maturity and number of seed set. Days …

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Production And Evaluation Of Antisera And Monoclonal Antibodies Directed Against The Serovar-Specific Lipopolysaccharide Antigens Of Vibrio Cholerae., Linda Benton Adams Jan 1987

Production And Evaluation Of Antisera And Monoclonal Antibodies Directed Against The Serovar-Specific Lipopolysaccharide Antigens Of Vibrio Cholerae., Linda Benton Adams

LSU Historical Dissertations and Theses

Vibrio cholerae is typed serologically on the basis of somatic O-antigens. The serovar-specific antigens A, B, and C of V. cholerae O1 are located in the polysaccharide (PS) moiety of the lipopolysaccharide (LPS) in the cell wall, but the exact structure and composition of these antigens are unknown. Presently, V. cholerae non-O1 serovars are differentiated serologically by two independent typing systems. Each system utilizes whole cell vaccines which result in typing sera containing serovar-specific, anti-PS activity and non-specific, cross-reacting activities. Serovar-specific anti-PS sera were produced in rabbits immunized with PS extracted from selected vaccine strains of V. cholerae O1 and …

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Effects Of Riverine Barriers On Genetic Differentiation Of Amazonian Forest Undergrowth Birds (Peru)., Angelo Paul Capparella Jan 1987

Effects Of Riverine Barriers On Genetic Differentiation Of Amazonian Forest Undergrowth Birds (Peru)., Angelo Paul Capparella

LSU Historical Dissertations and Theses

The high frequency with which rivers delimit phenotypically differentiated bird taxa is unique to Amazonia, where major rivers often form the boundaries between allospecies and subspecies pairs of understory terra firme forest birds. In contrast, many such forest species with life history traits similar to these differentiated forms show no variation in plumage across even the largest rivers. To determine whether such species are nonetheless genetically differentiated, I obtained tissue samples from populations of forest understory birds from opposite banks of the Napo and Amazon rivers of northeastern Peru. These included three species that are not phenotypically differentiated across the …

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Effects Of Interaction Between Red Rice And Two Rice Cultivars On Morphological, Physiological And Ecological Characteristics., Jairo Clavijo Jan 1987

Effects Of Interaction Between Red Rice And Two Rice Cultivars On Morphological, Physiological And Ecological Characteristics., Jairo Clavijo

LSU Historical Dissertations and Theses

Germination, emergence, and early seedling development patterns were analyzed for red rice (Oryza sativa L.) and the rice (Oryza sativa L.) cultivars Mars, Saturn, Lemont and Bellemont. Red rice had the highest germination percentage, fastest emergence rate, and earliest development of both shoots and roots. These results suggest that the competitive ability of red rice is based on these characteristics which enable it to preempt more resources at early stages of stand development. Interaction between red rice and Lemont or Mars was evaluated by comparing morphological and physiological characteristics of these plants when grown in pure stands and in 50:50 …

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Molecular Cloning And Sequencing Of The Bacillus Stearothermophilus 6-Phosphofructo-1-Kinase Gene And Of A Partial Rabbit Muscle 6-Phosphofructo-1-Kinase Complementary-Dna., Brent Arthur French Jan 1987

Molecular Cloning And Sequencing Of The Bacillus Stearothermophilus 6-Phosphofructo-1-Kinase Gene And Of A Partial Rabbit Muscle 6-Phosphofructo-1-Kinase Complementary-Dna., Brent Arthur French

LSU Historical Dissertations and Theses

A system is presented for determining the relationships between structure and function in the allosteric enzyme 6-phosphofructo-1-kinase (PFK). The ATP-dependent phosphorylation of fructose 6-phosphate to fructose 1,6-bisphosphate catalyzed by PFK is the first reaction unique to the glycolytic pathway. The structure-function relationships in PFK can now be addressed by site-specific mutagenesis. This is a method for directly testing hypotheses concerning the functions of individual amino acids in a protein molecule. The main body of this dissertation is composed of three sections. The first two sections describe the development of a system by which the structure-function relationships in Bacillus stearothermophilus PFK …

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In Vitro Regeneration And Protein Changes Associated With Two Cultivars Of Agrostis Palustris Huds. Cultured Under High Sodium-Chloride Conditions., John Casper Hovanesian Jan 1987

In Vitro Regeneration And Protein Changes Associated With Two Cultivars Of Agrostis Palustris Huds. Cultured Under High Sodium-Chloride Conditions., John Casper Hovanesian

LSU Historical Dissertations and Theses

Calli from 'Penneagle' and 'Seaside' creeping bentgrass (Agrostis palustris Huds.) were selected for enhanced ability to proliferate on media supplemented with 514 mM NaCl. Based on dry matter production and vigor, growth of plants regenerated from NaCl-adapted calli of both cultivars in saline hydroponic nutrient medium, was superior to that of plants regenerated from non-adapted calli. At 257 mM NaCl, plants from NaCl-sensitive calli died or were unable to produce measurable dry matter whereas plants from NcCl-adapted calli grew well. Growth of plants from NaCl-adapted calli was inhibited at 340 mM NaCl. At 514 mM NaCl, resistant plants no longer …

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The Rabbit Phosphofructokinase Genes: Molecular Cloning, Sequencing And Characterization., Ming-Ching Kao Jan 1987

The Rabbit Phosphofructokinase Genes: Molecular Cloning, Sequencing And Characterization., Ming-Ching Kao

LSU Historical Dissertations and Theses

Two rabbit phosphofructokinase (PFK) genomic clones were isolated from a lambda Charon 4A rabbit liver DNA library. A 180-bp rabbit muscle PFK cDNA encoding 60 amino acids in the C-terminal region of RM-PFK was used as a probe. By using the shotgun subcloning approach, we cloned, sequenced and characterized two rabbit PFK genomic clones. The two clones overlapped and represented a total length of 17 kb which encoded the entire RM-PFK protein. The organization of this gene was elucidated by restriction mapping and DNA sequencing. It contains 22 exons, ranging in size from 45 to 190 bp, separated by 21 …

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Insulin Receptors Of Erythrocytes And Liver Membranes In Dogs., Karen Johnson Wolfsheimer Jan 1987

Insulin Receptors Of Erythrocytes And Liver Membranes In Dogs., Karen Johnson Wolfsheimer

LSU Historical Dissertations and Theses

Insulin receptor assays using canine liver membranes and erythrocytes were validated for use in evaluating insulin receptor binding parameters within a healthy population of dogs. Association, dissociation, saturability and specificity were demonstrated for insulin receptors of canine liver membranes and erythrocytes. Assay precision was evaluated by measuring interassay coefficient of variation (liver membrane = 25.0%; erythrocytes = 9.3%). Because the number of high-affinity receptor sites and high-affinity K$\sb{\rm D}$ were determined using physiological concentrations of insulin, they were considered to be more physiologically important than the total number of receptor sites, low-affinity K$\sb{\rm D}$ and Ke, which were derived using …

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Feeding And Microspatial Relationships Of Meiobenthic Harpacticoid Copepods With Microbial Flora., Alan William Decho Jan 1987

Feeding And Microspatial Relationships Of Meiobenthic Harpacticoid Copepods With Microbial Flora., Alan William Decho

LSU Historical Dissertations and Theses

Feeding processes and their relationship to microspatial patterns were examined for several harpacticoid species. Field evidences and laboratory radiolabel experiments suggest that diatoms comprise a major portion of the food resources ingested by harpacticoids. Bacteria and mucus-exopolymer secretions (associated with the bacteria and diatoms) are also ingested, coincidently while ingesting diatoms. Also, significant ontogenetic shifts in food resource utilization occur from naupliar to adult stages. Field grazing rate studies were conducted on an intertidal mudflat over different portions of a tidal cycle using several harpacticoid species (Scottolana canadensis, Microarthridion littorale, Paronychocamptus huntsmani). Highest grazing rates for S. canadensis occurred just …

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The Production, Culture And Cryopreservation Of Bovine Demi-Embryos., Rickey Wayne Rorie Jan 1987

The Production, Culture And Cryopreservation Of Bovine Demi-Embryos., Rickey Wayne Rorie

LSU Historical Dissertations and Theses

The objective of experiment (Exp) I was to develop and evaluate a simplified method for producing bovine demi-embryos (DE). Treatment (Trt) A and B were the bisection zona pellucida intact (ZI) and free (ZF) embryos, respectively, using a microscope slide micromanipulator. In Trt C and D, ZI and ZF embryos, respectively, were bisected with a hand-held razor blade method. More DE were produced by the razor blade method (Trt C and D) than by the microscope slide micromanipulator method (Trt A and B). More DE were produced from ZF embryos (Trt B and D) than from ZI embryos (Trt A …

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Salinity Effects On The Development And Larval Tolerance Of Five Species Of Echinoderms., Richard Allen Roller Jan 1987

Salinity Effects On The Development And Larval Tolerance Of Five Species Of Echinoderms., Richard Allen Roller

LSU Historical Dissertations and Theses

Salinity effects on the developmental rates, larval tolerances and various metabolic processes of five species of echinoderms were investigated. Development of Lytechinus variegatus (Lamarck), Strongylocentrotus droebachiensis (O. F. Muller, 1776), Strongylocentrotus purpuratus (Stimpson, 1857), Strongylocentrotus pallidus (G. O. Sars, 1871), and Pisaster ochraceus (Brandt, 1835) larvae were observed. Developmental rates and larval survival to metamorphosis of S. droebachiensis and S. pallidus varied directly with salinity and were well within the observed salinity tolerance and distributional limits for the adults. For each species, embryos and larvae at lower salinities (20, 22.5, and $25\sp{o}\!/\!\sb{oo})$ tended to develop more slowly than those at …

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Regulation Of Dextransucrase Secretion By Proton Motive Force In Leuconostoc Mesenteroides., David Roland Otts Jan 1987

Regulation Of Dextransucrase Secretion By Proton Motive Force In Leuconostoc Mesenteroides., David Roland Otts

LSU Historical Dissertations and Theses

The relationship between proton motive force and the secretion of the enzyme dextransucrase (E.C. 2.4.1.5) in Leuconostoc mesenteroides was investigated. The transmembrane pH gradient was determined by measurement of the uptake of radiolabeled benzoate or methylamine while the membrane potential was determined by measurement of the uptake of radiolabeled tetraphenylphosphonium bromide. Leuconostoc mesenteroides was able to maintain a constant proton motive force of $-130$ mV when grown in fermenters at constant pH while a value of $-140$ mV was determined from concentrated cell suspensions. The contribution of the membrane potential and transmembrane pH gradient to the proton motive force varied …

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Physiological Aspects Of Bovine Mammary Involution: A Biochemical And Morphological Investigation., Lorraine Marie Sordillo Jan 1987

Physiological Aspects Of Bovine Mammary Involution: A Biochemical And Morphological Investigation., Lorraine Marie Sordillo

LSU Historical Dissertations and Theses

Quarter milk secretion samples and blood serum for compositional analysis were collected weekly from 29 cows beginning at drying off and continuing until 2 weeks postpartum. Quarter biopsies were taken from 5 additional animals at weekly intervals beginning at drying off through parturition. Histological and cytological parameters of tissues were correlated with biochemical characteristics of secretions. Increased tight junction permeability and decreased synthetic ability of secretory epithelium became evident by changes in mammary secretion composition and tissue morphology during the first 2 weeks of involution. Somatic cell counts, serum albumin, lactoferrin, immunoglobulin G, pH, total protein, and serum concentrations of …

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Ultrastructural And Molecular Studies Of The Fungus {\It Mucor\/}: The Mitochondrion And The Recombinant-Rna Genome., Geun Eog Ji Jan 1987

Ultrastructural And Molecular Studies Of The Fungus {\It Mucor\/}: The Mitochondrion And The Recombinant-Rna Genome., Geun Eog Ji

LSU Historical Dissertations and Theses

Mitochondria from aerobic hyphae of Mucor racemosus displayed a relatively elongated morphology with well developed cristae and stained in positive contrast. Mitochondria from anaerobic yeast cells were more circular in form, displayed less distinct but well recognizable cristae, and stained in negative contrast. Tween 80, ergosterol or cerulenin did not alter mitochondrial morphology when added to cultures. Mitochondria from cells grown in the presence of chloramphenicol displayed a morphology intermediate between those of yeast and hyphae and stained in negative contrast. Mitochondria were isolated by isopycnic centrifugation in Percoll. A single band in hyphal preparations displayed cyanide-sensitive respiration and was …

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Characterization Of Equine Infectious Anemia Virus Variants Generated In Vivo And In Vitro And A Rapid Assay For Virus-Specific Antibody., Paul Murumba Rwambo Jan 1987

Characterization Of Equine Infectious Anemia Virus Variants Generated In Vivo And In Vitro And A Rapid Assay For Virus-Specific Antibody., Paul Murumba Rwambo

LSU Historical Dissertations and Theses

Three Shetland ponies (A, B and C) were inoculated with plasma from a pony with clinical signs of equine infectious anemia (EIA) and observed for 165 to 440 days. Clinical signs of EIA marked by high fever (39.5$\sp\circ$C) lasting 2-4 days were observed 2-3 weeks after infection and one to four such episodes occurred in each pony. EIAV was reisolated from plasma by end-point dilution in fetal equine kidney (FEK) cells and a plasma viremia 10$\sp{3.5}$ TCID$\sb{50}$/ml was observed during each episode. A total of seven virus isolates were recovered. Cross-neutralization tests with sequential serum samples showed that four viruses …

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Interactions Of Weed, Nematode, And Arthropod Management Strategies With The Louisiana Sugarcane Agroecosystem: A Holistic Perspective., Allan Thomas Showler Jan 1987

Interactions Of Weed, Nematode, And Arthropod Management Strategies With The Louisiana Sugarcane Agroecosystem: A Holistic Perspective., Allan Thomas Showler

LSU Historical Dissertations and Theses

Interactions among Louisiana sugarcane (Saccharum hybrids), weeds, nematodes, sugarcane mosaic virus (SCMV), and pest, prey, and predatory arthropods were mediated through tropic, host plant biochemical, and intra- and interspecific competitive relationships. Weed competition reduced crop biomass (15%, P $\le$ 0.005), and sugar yield (13%, P $\le$ 0.05). Weeds, however, were associated with more predatory arthropods, including Solenopsis invicta Buren, on the soil, weeds, and sugarcane plants, and with reduced Diatraea saccharalis (F.) injury (over 25%, P $\le$ 0.05). Without chemical D. saccharalis control, sugarcane production in weedy habitats was economically superior to that in weed-free habitats. Aldicarb, a nematicide-insecticide, diminished …

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Geographic Variation In Morphology And Allozymes Within Tree Squirrels, Sciurus Niger And S. Carolinensis, Of The Lower Mississippi River Valley., Nancy D. Moncrief Jan 1987

Geographic Variation In Morphology And Allozymes Within Tree Squirrels, Sciurus Niger And S. Carolinensis, Of The Lower Mississippi River Valley., Nancy D. Moncrief

LSU Historical Dissertations and Theses

Geographic variation was studied in fox squirrels, Sciurus niger, and gray squirrels, S. carolinensis, by comparing patterns of differentiation within and between these two sympatric species. Patterns of variation were examined in light of the lower Mississippi River as a potential barrier to dispersal and gene flow in these squirrels. Differences within and between species were analyzed using morphologic (15 cranial and mandibular measurements) and allozymic (35 presumptive gene loci) characters. Geographic patterns of variation among populations were apparent in the morphology and allozymes of both species; patterns of differentiation in morphologic and allozymic characters are similar between species; however, …

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A Study Of The Effects Of Utilizing The Writing Process As An Instructional Strategy On Student Thinking Skills In Ninth-Grade Biology Courses, Gene P Butler Jan 1987

A Study Of The Effects Of Utilizing The Writing Process As An Instructional Strategy On Student Thinking Skills In Ninth-Grade Biology Courses, Gene P Butler

UNLV Retrospective Theses & Dissertations

This was an initial study that examined the effect of the type of instruction used in biology I classrooms on learner development of critical thinking, as measured by the Watson-Glaser Critical Thinking Appraisal. Form A of the instrument was used as the pretest, and Form B of the instrument was used as the posttest. The independent variable was teaching method and consisted of two levels: (1) "the writing process," as a teaching method adapted for science instruction, and (2) the "traditional" teaching method, which relied on lecture, discussion, textbook assignments, and verification laboratories; Three teachers from schools within the Clark …

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