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The Putative Role Of Fatty Acids In The Activation Of Trehalose Synthesis In The Fat Body Of The Cockroach Periplaneta Americana L, Irshad Ali

Digitized Theses

Hypertrehalosemic hormones produced by the corpus cardiacum increase the concentration of several fatty acids in cockroach fat body trophocytes. The phospholipase A{dollar}\sb2{dollar} (PLA{dollar}\sb2){dollar} activator melittin has a similar effect. The fatty acids include palmitic, stearic, oleic and linoleic acid. The hormone mediated release of these fatty acids is blocked by the PLA{dollar}\sb2{dollar} inhibitors mepacrine and {dollar}\rho{dollar}-bromophenacyl bromide. These observations suggest that hormonal release of fatty acids, may be due to the activation of PLA{dollar}\sb2.{dollar};The increase in non-esterified fatty acids appears to be linked to the increase in trehalose efflux since sugar efflux is stimulated by stearic, oleic, linoleic and arachidonic …

Mechanisms Of Autonomic Control By The Insular Cortex In The Rat, Kenneth Scott Butcher

Digitized Theses

The insular cortex (IC) has been proposed to act as visceral sensory and autonomic cortex. The mechanism of control by the IC, however, is not clear. The nature of insular cortical function in hypertension is also unknown.;Middle cerebral artery occlusion (MCAO) in Wistar rats has been shown to cause cortical infarction, including the IC, resulting in increases in sympathetic nerve discharge (SND). MCAO in the urethane anesthetized spontaneously hypertensive rat (SHR) resulted in decreases in arterial pressure (AP) and SND.;To determine if the autonomic effects of MCAO in the SHR and Wistar rat are due to insular damage, a lesion …

Characterization Of Fungal Fimbriae, Martina Celerin

Digitized Theses

Fungal fimbriae are surface appendages that were first described by Poon and Day (1974) on the haploid cells of Microbotryum violaceum. They are long (1 to 20 {dollar}\mu{dollar}m), narrow (7 nm) flexuous fibres that were implicated in important cellular functions such as mating and pathogenesis. Since this initial description, numerous other fungi from all five phyla have been shown to produce fimbriae on their extracellular surfaces. Because they are easy to purify, the fimbriae from M. violaceum have been investigated most extensively. The present study extends the earlier characterizations of M. violaceum fimbriae, and expands on the biochemical description of …

Effects Of Industrial Effluents On Populations Of The Freshwater Mussel Lampsilis Radiata In The St Lawrence River, Lee Curtis Grapentine

Digitized Theses

The objective of this study was to assess the effects of industrial discharges, contaminated primarily with trace metals, on populations of Lampsilis radiata (Bivalvia: Unionidae) in the upper St. Lawrence River. Effects on shell growth were examined by (a) comparing growth curves derived from analyses of external annual rings of clams sampled from sites located upstream and downstream of four localized sources of discharges, and (b) measuring shell growth for one year from clams that were transplanted into contaminated and uncontaminated sites. Allozyme frequencies in clams from above and below discharges were determined for glucose-phosphate isomerase (GPI) and phosphoglucomutase (PGM), …

Evolutionary Dynamics At Two Loci Of The Human Genome As Assessed By Examination Of Nucleotide Sequence Diversity And Organization, Kathleen Allen Hill

Digitized Theses

Accurate and comprehensive measurement of the extent and pattern of nucleotide diversity is necessary to refine theories on the dynamics of evolution. It is possible to determine the sequence of any genomic region for numerous individuals using the polymerase chain reaction (PCR) and associated techniques of DNA sequence analysis. The two regions of the human genome examined in this study were the third exon of the highly conserved (two major alleles) alcohol dehydrogenase, Adh2 locus and the second exon of the highly polymorphic (26 alleles) human leukocyte antigen, HLA-DQ{dollar}\beta{dollar}1 gene. Sequence information was determined from 25 individuals from Southwestern Ontario …

The Regulation Of A Type Iv Phosphodiesterase From L6 Myoblasts, A Thomas Kovala

Digitized Theses

A potential role for cAMP in regulating the differentiation of myoblasts has lead to the examination of the components of the cAMP signalling system, in this case a cyclic nucleotide phosphodiesterase (PDE). A Type IV PDE isozyme was identified in L6 myoblasts using consensus sequence PCR primers, and its regulation by cAMP studied. Sequencing of RT-PCR products showed the presence of a Type IV PDE mRNA known as ratPDE 3.1. High levels of cAMP induced dramatic increases in the PDE mRNA levels as demonstrated by northern blot analysis. Run-off transcription experiments showed increased rates of transcription. L6 myoblasts which had …

Photosynthetic Acclimation To Light And Temperature: Excitation Pressure And Redox Sensing, Denis Philip Maxwell

Digitized Theses

Photosynthetic acclimation to low temperature has been studied extensively. However, since low temperature causes a preferential decrease in the rates of biochemical as compared to photochemical reactions, some alterations brought about by acclimation to low temperature may be the result of the light-harvesting apparatus absorbing more light energy than can be readily dissipated through photosynthesis. This possibility was investigated by using two species of green algae, Chlorella vulgaris and Dunaliella salina and the techniques of chlorophyll a fluorescence, O{dollar}\sb2{dollar}-evolution, protein electrophoresis and Western blotting, high performance liquid chromatography, RNA blot hybridization, and enzyme and metabolite assays. Compared to algae grown …

Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin

Digitized Theses

Skeletal muscle consists of multinucleated fibres which are classified as slow (I) or fast (IIA, IIB, IIX) muscle fibre types which differ in their contractile properties and their expression of contractile protein isoforms. Individual muscles contain characteristic distributions of fibre types which can be identified based on their myosin heavy chain (MyHC) content. While classical studies have demonstrated that the fibre type composition of adult muscles can be altered by extrinsic factors (such as changes in the pattern of innervation), recent studies suggest that different fibre types may be formed from distinct myoblast lineages. The purpose of this study was …

Epidermal Growth Factor Regulation Of Porcine Oocyte Maturation And Cumulus Cell Expansion In Vitro, Balwant Singh

Digitized Theses

The overall objective of this study was to investigate the role in vitro of epidermal growth factor (EGF) in the regulation of both nuclear and cytoplasmic maturation of the porcine oocyte, and in the expansion of cumulus cells.;Studies aimed at the induction of oocyte maturation and cumulus expansion revealed that EGF is a potent stimulant of the resumption of meiosis in the oocyte and that the addition of FSH, but not LH, to EGF further enhances its effect on germinal vesicle breakdown (GVBD). Both estradiol-17{dollar}\beta{dollar} (E{dollar}\sb2{dollar}) and androstenedione (A{dollar}\sb4{dollar}) inhibited FSH-stimulated GVBD, but had no effect on EGF-stimulated GVBD, suggesting …

Feedback Control Mechanisms Regulating Breathing In Humans, Croix Claudette St

Digitized Theses

The respiratory system regulates alveolar ventilation (V{dollar}\sb{lcub}\rm A{rcub}{dollar}) almost exactly to the demands of the body so that the PCO{dollar}\sb2{dollar} and PO{dollar}\sb2{dollar} of the arterial blood are hardly altered, even during strenuous exercise or other types of respiratory stress. The feedback control of ventilation was studied in human subjects using the technique of dynamic end-tidal forcings to produce perturbations in end-tidal PCO{dollar}\sb2{dollar} (P{dollar}\sb{lcub}\rm ET{rcub}{dollar}CO{dollar}\sb2{dollar}) and end-tidal PO{dollar}\sb2{dollar} (P{dollar}\sb{lcub}\rm ET{rcub}{dollar}O{dollar}\sb2{dollar}) to stimulate the respiratory chemoreceptors.;The purpose of the first study was to investigate the interaction between ventilatory drives from the central (cR{dollar}\sb{lcub}\rm c{rcub}{dollar}) and peripheral (pR{dollar}\sb{lcub}\rm c{rcub}{dollar}) chemoreceptors using their different …

Programming Of Muscle Activity In Arm Movements In Relation To Force Requirements, Naznin Virji-Babul

Digitized Theses

Analysis of the relationship between movement kinematics and muscle activity is a widely used approach for understanding how the nervous system formulates motor commands to produce movements. In planar single joint movements, phasic muscle activity is highly correlated with specific kinematic variables. Such correlations have not proven to be as direct in complex movements. The rules used by the nervous system in movement coordination are thus poorly understood. The purpose of this study was first, to examine kinematics, dynamics and electromyographic (EMG) activity during single and two-joint arm movements to discern the common planning strategies between these movements; and second, …

The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu

Digitized Theses

Bacteriophage Mu is one of the model systems to study DNA transposition. The availability of an in vitro soluble system greatly facilitates the dissection of the transposition mechanisms at the molecular levels. Several aspects of the in vitro mini-Mu DNA transposition have been dealt with in this thesis.;First, the flanking host DNA sequences on the strand cleavage step mediated by Mu transposase (Mu A protein) was investigated. We found that certain flanking host sequences could inhibit the strand cleavage step without affecting the earlier synapsis step. Furthermore, this cleavage defect could be overcome by the Mu B protein in the …

A Comparative Study Of The Ecology Of Smooth Flounder, Pleuronectes Putnami, And Winter Flounder, Pleuronectes Americanus, From Great Bay Estuary, New Hampshire, Michael Patrick Armstrong

Doctoral Dissertations

Smooth flounder, Pleuronectes putnami, and winter flounder, Pleuronectes americanus, co-occur in estuaries along the east coast of North America from Labrador to Massachusetts. Results of a three year sampling program indicated that the two species were partially segregated along salinity and depth gradients in upper Great Bay Estuary, New Hampshire. Along the salinity gradient, smooth flounder were most abundant at the oligo-mesohaline riverine habitat while winter flounder were most abundant at the meso-polyhaline open bay habitat. Both species exhibited a generalized up-river movement with seasonally increasing salinity. Smooth flounder showed ontogenetic changes in distribution along the depth gradient, with the …

Nucleotide And Energy Metabolism During Visual Transduction In Electropermeabilized Rod Outer Segments, Vincent J. Coccia

Doctoral Dissertations

Cyclic GMP and calcium are known to be messengers involved with visual transduction in vertebrate rod photoreceptor outer segments (ROS). However, it has been difficult to study the interrelationship of the calcium and cGMP signaling pathways using biochemical methods. An electropermeabilized rod outer segment (EP-ROS) preparation has been developed to examine these problems.

Square-wave electric field pulses were used to generate permanent disruptions in the plasma membrane of ROS. This treatment also permeabilized the disk membranes within the organelle. EP-ROS retain the characteristic morphology of osmotically intact ROS at the light microscopic level, but are permeable to low molecular weight …

Comparison Of Chlorine And Chlorine Dioxide As Disinfectants For Surface Waters, Kristen S. Tilton

Doctoral Dissertations

Safe supplies of drinking water free of pathogenic agents such as viruses and protozoa are essential for humankind. The evaluation of current treatment practices for the removal of pathogens has become increasingly important with the occurrence of waterborne disease outbreaks. Shortcomings associated with chlorine have prompted the need to assess alternative disinfectants.

The overall objective of this research is to compare chlorine and chlorine dioxide as disinfectants for surface waters using Giardia muris cysts, bacteriophage MS2, total and fecal coliforms, and heterotrophic bacteria. Concentration x time (CT) values for the inactivation of Giardia muris cysts and MS2 bacteriophage as a …

A Proposed Acrosomal System For Identifying Stages Of The Cycle Of The Seminiferous Epithelium And A Model For The Kinetics Of Spermatogenesis In The Rabbit, Antonio Carlos S Castro

Doctoral Dissertations

Most quantitative investigations of spermatogenesis requites identification of stages of the cycle of the seminiferous epithelium. The current "tubular morphology" system of staging for the rabbit permits identification of only eight stages and is not applicable to all experimental conditions. A more advantageous staging system, based on changes in the acrosome and morphology of the developing spermatids, had not been developed for the rabbit. Knowledge of spermatogonial kinetics, including the identity of spermatogonial subtypes and the number and timing of spermatogonial divisions, is also important, but had not been fully elucidated in this species. This investigation was undertaken to develop …

Molar And Local Effects Of The Fixed-Ratio Changeover Requirement On Choice, Changeovers, And Visits: A Parametric Examination Of The Fixed-Ratio Changeover Requirement, Michael B. Ehlert

Doctoral Dissertations

The distribution of behavior by organisms in choice situations is of long-standing interest to psychologists. The generalized matching relation accurately predicts choice between concurrent variable-interval schedules of reinforcement. Researchers have assumed, on weak grounds, that the effect of the changeover requirement on sensitivity to reinforcement--the exponent in the generalized matching equation--was consistent. This experiment considered the effects of the changeover requirement by parametrically manipulating the fixed-ratio schedule required to switch alternatives. Pigeons pecked either of two side-response keys in a standard three-key operant chamber for food, delivered according to independent variable-interval schedules. No changeover delay was used, instead completion of …

Chilling Photoinhibition In Zea Mays L And Zea Diploperennis Iltis, Doebely And Guzman: The Role Of Oxygen And Antioxidants, Kajal Bose Ghoshroy

Doctoral Dissertations

Light absorbed by photosynthetic pigments must be distributed either for chemical work, reemitted as fluorescence or safely dissipated as heat. Adverse environmental conditions reduce the dissipation capacity of plants and the excess energy leads to damage to the photosynthetic mechanism, termed photoinhibition. Low, non-freezing temperatures cause such photoinhibition, especially in tropical plants grown in the temperate zone. This damage occurs in the photosystem II and is triggered by highly reactive radicals or reactive forms of dioxygen. Numerous studies point to the involvement of oxygen and antioxidant enzymes and substrates in amelioration of these damages. In C$\sb3$ plants, dioxygen is thought …

Population Dynamics And Recruitment Ecology Of Some Caribbean Reef Corals, David B. Carlon

Doctoral Dissertations

Processes that limit the distribution arid abundance of marine species may affect larvae, juveniles, or adults. I focus on larval and early benthic phases of reef corals as determinants of spatial pattern. In CHAPTER I examine larval behavior during dispersal and settlement as a mechanism for aggregated spatial pattern in two corals. A short swimming period and non-selective settlement behavior explains the highly aggregated spatial pattern in Favia fragum. Spatial pattern in Agaricia agaricites probably reflects larval behavior at settlement and post-settlement mortality. These larvae had a longer planktonic period and were selective in settlement surfaces.

In CHAPTER II, I …

Isolation And Characterization Of The Ccr4 Associated Factors, Haiyan Liu

Doctoral Dissertations

In yeast, Sacchoromyces cerevisiae, transcription of $\underline{ADH2}$ gene (encodes alcohol dehydrogenase II) under glucose derepression conditions requires not only the gene-specific activator, Adr1p, but also the general transcriptional factors like Ccr4p. Ccr4p belongs to the LRR-containing protein superfamily, members of which have often been found to associate with other proteins to form a functional protein complex. This dissertation reports three major conclusions from my research.

1. The CCR4 protein is associated with at least three other proteins by immunoprecipitation using the CCR4 antibody, and more importantly, the LRR in the CCR4 protein is not only essential, but also sufficient to …

Characterization Of The Adherence Mechanisms Of Listeria Monocytogenes To Host Cells And Their Role In The Pathogenesis Of Listeriosis, Marcia M. Pierce

Doctoral Dissertations

Listeria monocytogenes is the facultative intracellular pathogen responsible for causing the foodborne illness known as listeriosis. Disease occurs following invasion of cells of the intestinal tract by the organism following consumption of contaminated foods. In this study, a mechanism of opsonin-independent attachment of L. monocytogenes to host cells was identified. A clinical isolate of L. monocytogenes, together with murine-derived primary peritoneal macrophages were used to study this adherence phenomenon.

Transmission and scanning electron microscopy were used to visualize the attachment and uptake of L. monocytogenes by murine macrophages, while organism enumeration by viable bacterial cell colony counts was used as …

The Molecular Process By Which Streptococcus Pneumoniae Activates The Immune System During Pneumococcal Infection, Brandon Abeyta

Whittier Scholars Program

This project includes a review of literature detailing the human body's defense mechanisms against Streptococcus pneumoniae. Research includes the use of a rabbit-model of the human immune system searching for a vaccine by experimenting with different portions of pneumococcal cell wall. Comprehend infection with the conclusions the cell walls are a powerful inducer of inflammatory response. Studied at Rockefeller University and learned under Dr. Elaine Tuomanen at Laboratory of Molecular Infectious Diseases.

Biology Of The Tao, Matthew D. Sellers

Whittier Scholars Program

Much of this project is merely based on perspective. My perspective, that of the philosophies that I am attempting to highlight, and that of the sources where I am lifting facts from as fast as I can grab them, all go into this work. I feel myself to be somewhat of an editor, quilting together pieces of intuition and data in ways that attempt to unify these perspectives. The essays that follow seek to look at ways in which nature follows the quiet, yielding tenets of the Tao; reciprocally, the Tao Te Ching will be shown to accurately reflect the …

Increased Salinity And Water Depth As Constraints On Growth Of Freshwater Marsh Plants., Rebecca J. Howard

LSU Historical Dissertations and Theses

Three experiments were conducted to evaluate the response of freshwater-oligohaline marsh macrophytes to increased water depth and salinity. In the first experiment, marsh sods containing Sagittaria lancifolia were manipulated in the field to decrease elevation (i.e., increase water depth) by 7.5 and 15 cm. Marsh sods at 15 cm below the marsh surface had the lowest redox potential and highest interstitial water sulfide concentration. Plants in the 15-cm water depth treatment had higher mean and maximum leaf heights than disturbed control plants, but aboveground biomass was not affected. In the second study, the effects of salinity pulses on plant growth …

Pollen Influence On Developmental Physiology Of Southern Highbush Blueberry (Vaccinium Corymbosum) Fruit., Yue He Huang

LSU Historical Dissertations and Theses

To study the physiological and biochemical effects of pollen sources on fruit growth and development of southern highbush blueberry (Vaccinium corymbosum hybrids), five-year old 'Sharpblue' plants were grown in a greenhouse for self- and cross-pollination experiments. Cross-pollination with 'Gulfcoast' and 'O'Neal' as pollen sources increased fruit weight by 58.2% and 54.9%, respectively, compared to self-pollination. Coincidentally, cross-pollination doubled the number of mature ovules, and increased their size by 14%. Ovule abortion occurred between 5 and 10 days after pollination (DAP) in both pollination treatments. More abortion occurred in self-pollination (35%), compared with cross-pollination (22% for 'Sharpblue' $\times$ 'O'Neal' and 29% …

Behavioral And Morphological Development Of Immature Hawaiian Freshwater Fishes., David Chestine Tate

LSU Historical Dissertations and Theses

Studies of recent fish collections from 17 streams on four islands in Hawai'i provided key characteristics for species identification of immature forms of five native species of freshwater gobioids. Young Eleotris sandwicensis lack fused pelvic fins. A suborbital bar identifies Stenogobius hawaiiensis. Awaous guamensis can be distinguished by lack of notches in the upper lip, Lentipes concolor by a single median notch, and Sicyopterus stimpsoni by three notches. Recruitment from oceanic plankton occurred year round but peaked from February to April. Lentipes invaded streams mainly during the day with the wave surge; Sicyopterus entered mostly during the day regardless of …

Functional Anatomy Of The Integument And Subcutaneous Structures Of The Head, Neck And Thorax Of The Domestic Turkey, Meleagris Gallopavo., Kumudini Nishantha De Silva

LSU Historical Dissertations and Theses

The microdissection of the integument and subcutaneous structures of the head, neck, and thorax of the Domestic Turkey, Meleagris gallopavo, revealed a complex system with several distinct layers of connective tissue, smooth and striated musculature, and fat bodies (corpora adiposa). These layers show structural variations across the body surface, and the patterns of variation of the different layers correlate with one another. The smooth apterial muscles and the striated subcutaneous muscles complement each other in moving certain feather tracts. Fat tissue is deposited in the dermis as dermal fat, in the Fascia superficialis, and in distinct fat bodies associated with …

Biogeographic, Ecological, And Evolutionary Aspects Of South American Austral Migration, With Special Reference To The Family Tyrannidae., Robert Terry Chesser

LSU Historical Dissertations and Theses

South American austral migrants are bird species that breed in temperate South America in the southern summer and migrate north, towards or into northern South America, for the southern winter. Austral migration is similar to other avian migration systems in many ways, but its uniquely South American locale is reflected geographically by the relatively short-distance migrations of most austral migrants, and taxonomically by the numerical dominance of the suboscine family Tyrannidae (the tyrant-flycatchers), of which more than 70 species migrate. Detailed examination of the distributions of austral migrant flycatchers revealed that each is to some extent unique, but that discernible …

Scientific Discipline And The Origins Of Race: A Foucaultian Reading Of The History Of Biology, Ladelle Mcwhorter

Philosophy Faculty Publications

Foucault's "power-knowledge" is a controversial concept. Brought into English-speaking theoretical circles less than two decades ago, its meaning and range of applicability are still in dispute. While no one denies that some fields of social scientific knowledge (such as criminology) intersect institutionally with mechanisms of power, these intersections do not seem, to many, to constitute any essential relation of "mutual reinforcement" between knowledge and power. If, in rare cases, politics and scientific research are admitted to be mutually constitutive, the results of their mingling are typically dismissed as propaganda or pseudo-science. A few thinkers are willing to allow the entirety …

Life History And Description Of Immature Stages Of Euaresta Stigmatica (Diptera: Tephritidae) On Ambrosia Spp. (Asteraceae) In Southern California, David H. Headrick, Richard D. Goeden, Jeffrey A. Teerink

Horticulture and Crop Science

Euaresta stigmatica Coquillett is bivoltine and nearly monophagous on four native ragweeds, Ambrosia spp. (Asteraceae), in the southwestern United States. In southern California, larvae of the spring (F₁) generation develop singly in and feed on one or both ovules of young fruiting involucres of Ambrosia ilicifolia (Gray) Payne, with a small proportion infesting the staminate involucres. Adults emerge after ≈1 mo, with their reproductive organs immature. The F₂ generation develops in the involucres of fall-blooming Ambrosia acanthicarpa Hooker. The egg is described and illustrated for the first time for any species of Euaresta. First, second, and …