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Characterization Ofp53 Gene Sequence In Exons 5-8 Of The Western Mosquito Fish, Gambusia Affinis., Neeraja Kondapi Erraguntla

LSU Historical Dissertations and Theses

Cancer is a multistage disease that involves both genetic and epigenetic factors. The number of physical and chemical agents with which human beings come in contact on a regular basis is increasing everyday. Somatic mutations can result due to such exposures and trigger uncontrolled cell division resulting in cancer. The p53 tumor suppressor gene has been identified in several vertebrate species ranging from man to fish. In addition, inactivation of p53 has been observed in a wide variety of tumors. Fish models are becoming increasingly popular for assessing environmental exposure. Low background incidence of mutations, relatively low cost tumor studies, …

Comparative Structure And Function Of Intrinsic Gill Muscles In Freshwater Bivalve Molluscs., Scott Medler

LSU Historical Dissertations and Theses

The lamellibranch gill is used for various vital functions ranging from food capture to ion regulation. The foundation for many of these functions is the transport of water through the gill. This dissertation examines the organization of intrinsic gill muscles and the associated connective tissue in the freshwater bivalve Dreissena polymorpha with comparisons made to Corbicula fluminea and Toxolasma texasensis. Gill muscles can be divided into two groups: those associated with the connective tissue sheets that underlie external and internal gill epithelia; and those encased in connective tissue bands oriented perpendicular to the bases of gill filaments. The sets of …

Early Fertilization Events In The Freshwater Zebra Mussel, Dreissena Polymorpha., Michael James Misamore

LSU Historical Dissertations and Theses

The morphological and functional mechanisms involved in the early fertilization events in the freshwater zebra mussel Dreissena polymorpha (Bivalvia:Veneroida:Dreissenidae) are presented. Mature adults release gametes in response to external applications of 5-hydroxytryptamine. Sperm retain a primitive morphology consisting of a head, midpiece and tail The head is approximately 1.6 $\mu$m in diameter and 4 $\mu$m in length. An acrosomal vesicle is highly compartmentalized with a central axial core containing actin. The midpiece is composed of 4 mitochondria and a pair of centrioles. A single flagellum is elaborated from the distal centriole. The eggs of D. polymorpha are 50-60 $\mu$m in …

Cerebral Hemoglobin Oxygen Saturation In Patients With Restless Legs Syndrome And Periodic Limb Movements In Sleep., Mark Jude Hurry

LSU Historical Dissertations and Theses

Pathogenic theories of Restless Legs Syndrome (RLS) and Periodic Limb Movements in Sleep (PLMS) were reviewed and critiqued, and a new theory for the pathogenesis of RLS and PLMS was presented. It was proposed that both disorders are caused by sleep-related hypoperfusion in the area of the cerebral cortex that mediates sensation and movement in the legs. The hypoperfusion was proposed to be caused by high amplitude oscillations in total cerebral blood flow known as B-waves and by flow-reducing turbulence at several of the bifurcations in the anterior cerebral artery. This theory was tested by using near infrared spectroscopy (NIRS) …

Detection Of Mechanisms Of Profenofos Resistance In The Tobacco Budworm, Heliothis Virescens (F.)., John Ambrose Harold

LSU Historical Dissertations and Theses

Biochemical and physiological mechanisms of profenofos resistance in laboratory and field populations of the tobacco budworm, Heliothis virescens (F.) were studied. High frequencies of profenofos resistance were recorded in all field-collected strains and were strongly correlated with esterase (EST) activity and moderately correlated with glutathione S-transferase activity. Mean levels of acetylcholinesterase (AChE) sensitivity to inhibition by chlorpyrifos oxon were lower in some field strains than levels in an insecticide-susceptible strain; however, AChE sensitivity and resistance were poorly correlated in all field strains. There was no correlation between resistance and the activities of P450-monooxygenase or glutathione S-transferase measured. Studies with laboratory-selected …

Identification Of Antigens Of Edwardsiella Ictaluri, The Causative Agent Of Enteric Septicemia Of Catfish (Esc)., Michelle Marie Moore

LSU Historical Dissertations and Theses

Edwardsiella ictaluri, causative agent of enteric septicemia of catfish (ESC), is the primary bacterial pathogen of commercially produced channel catfish (Ictalurus punctatus). The purpose of this study was to make progress towards development of a successful ESC vaccine by generating and characterizing a pool of E. ictaluri antigens and determining if they were protective against ESC in catfish. Antigenic protein expression was evaluated in E. ictaluri cells under different conditions of growth using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and western blotting with pooled convalescent catfish serum (CCS). Results showed protein bands separated by one-dimensional PAGE may consist of one or …

Airbirds: Adaptative Strategies To The Aerial Lifestyle From A Life History Perspective., Manuel Marin-Aspillaga

LSU Historical Dissertations and Theses

"Airbirds" are defined as those birds that are adapted to almost constant life on the wing and do not perch, except for breeding and roosting. They use the air as the only medium in which to find and gather food. One taxon meets that definition: the swifts (Apodidae). Foraging zones of airbirds can be segregated in terms of clutch size, commuting foraging distance, nestling period, and nestling feeding rate. This study looked at foraging behavior and nestling diet, incubation patterns and mode of development in cypseloidine swifts, that as a group has extreme life history patterns. In a temperate one-egg …

The Effects Of Pah-Contaminated Sediments On Benthic-Feeding Fishes And Their Associated Prey., Candace Gay Hinkle-Conn

LSU Historical Dissertations and Theses

Subtidal sediments near Port Fourchon, Louisiana, USA, have been contaminated with produced water, as indicated by the levels of polycyclic aromatic hydrocarbons (PAH) for over four decades. Studies were undertaken to examine the effect of produced water/PAH on the potential for trophic transfer (from meiofauna and small macrofauna to benthic-feeding fishes) of sediment-bound contaminants. A survey of meiofaunal communities along a putative pollution gradient from the produced water outfall to a distance of 1 km found that meiofauna densities were significantly higher at the most contaminated sites ($\sim$10,000 ng PAH g$\sp{-1}$ dry sediment). The community at the most contaminated sites, …

Serological And Molecular Biological Studies Of Marine Predator-Prey Systems., Marilyn J. Hoyt

LSU Historical Dissertations and Theses

Two aspects of species identification were addressed; a molecular approach to identify anchovy larval and serological methods for prey detection in predator gut washes. Analysis of the pattern of restriction fragments of mitochondrial DNA (mtDNA) from adult anchovies from the Gulf of Mexico was employed to speciate four anchovy species. MtDNA isolated from white muscle of adult Anchoa mitchilli, A. hepsetus, A. nasuta and Engraulis eurystole produced an amplified 2.4 Kb DNA product when primers for NADH dehydrogenase 5 and 6 genes were used in polymerase chain reactions (PCR). Digestion of the amplified sequence with Dpn II produced a unique …

A Study On Ecology And Biology Of Microtus Guentheridanford And Alston,1880 (Mammalia: Rodentia) In Turkey, Ercüment Çolak, Mustafa Sözen, Nuri Yi̇ği̇t, Şakir Özkurt

Turkish Journal of Zoology

In this study, ecology and biology of Microtus guentheriwere investigated based on both field and laboratory observations along with its effects on agricultural crops. It was determined that this vole has a shallow burrow with numerous entrances and does not store food in its burrow. In captivity, M. guentherigave litters from September to June and a female produced 42 pups, being seven litters during a reproduction season. The duration of pregnancy varied 20 to 21 days. The average litter size was 5.5 and young were born in an average weight of 3.3 g. The fur developed at an age of …

Reproductive Isolation Between Two Species Of Topminnow, Fundulus Olivaceus And F. Euryzonus., Thomas Allen Blanchard

LSU Historical Dissertations and Theses

Fundulus olivaceus and F. euryzonus are sister species that commonly occur syntopically in the Amite and Tangipahoa River drainages in Louisiana and Mississippi. Although the habitats of the two species are quite similar, and the timing of their reproductive activity overlaps extensively, no natural hybrids between them have been documented. I examined physiological, as well as behavioral, factors that could potentially serve as effective isolating mechanisms between them. The courtship and spawning behaviors of the two species were relatively generalized and showed a number of similarities. Under forced mating conditions in which females were allowed to associate with heterospecific males …

Cloning And Identification Of Chlamydomonas Reinhardtii Genes And Proteins Upregulated Under Low Carbon Dioxide Conditions., Aravind Somanchi

LSU Historical Dissertations and Theses

A mechanism that concentrates CO$\sb2$ in cells of Chlamydomonas reinhardtii, is induced when cells are grown at low CO$\sb2$ conditions. This mechanism increases the CO$\sb2$ concentration at the site of RuBisCO, and thereby improves the efficiency of C$\rm\sb{i}$ uptake and fixation. Cells adapting to low CO$\sb2$ show significant physiological changes. Few of the genes encoding proteins needed to produce these changes have been identified. A cDNA library has been constructed from C. reinhardtii to identify genes involved in these changes. The cloning and identification of several cDNAs that are upregulated under low CO$\sb2$ conditions are reported here. The possible roles …

Dynamics And Management Of Insecticide Resistance In The Horn Fly, Haematobia Irritans Irritans (L.) (Diptera: Muscidae)., Antonio Thadeu Medeiros De Barros

LSU Historical Dissertations and Theses

Studies on resistance of the horn fly, Haematobia irritans irritans (L.), to insecticides were conducted in Louisiana from 1989 to 1998. These studies included monitoring resistance and resistance dynamics under different strategies of insecticide use, monitoring the efficacy of insecticide products, establishing a relationship between bioassay findings and product efficacy, and evaluation of a new insecticide class. In four years (1989--1992), efficacy of 20% diazinon-impregnated car tags used yearly was reduced from greater than twenty to just one week of control, and tag failure was observed with resistance ratios (RR) from 1.8 to 5.7. Diazinon resistance developed more slowly and …

Purification Of Porphobilinogen Deaminase And The Sequencing And Expression Of Thehemc Gene Of Rhodobacter Capsulatus., Keith A. Canada

LSU Historical Dissertations and Theses

Rhodobacter capsulatus uses the common tetrapyrrole pathway to synthesize heme, bacteriochlorophyll, siroheme and vitamin B-12. As part of our studies on the regulation of this pathway, the product of the hemC gene, porphobilinogen deaminase was purified approximately 200-fold. The molecular weight, isoelectric point, pH optimum and Km of the enzyme were all similar to other porphobilinogen deaminases. The stoichiometry of the enzyme was found not to be the expected four porphobilinogens used per one uroporphyrin formed. Rather a 9:1 ratio was typically seen. Further study of this atypical ratio uncovered evidence of possible in vivo regulation of porphobilinogen deaminase dependant …

Materials Fluxes Across Different Scales Of Time And Space In The Rhone Delta, France., Philippe Francois Hensel

LSU Historical Dissertations and Theses

A study of materials fluxes across different scales of time and space was conducted in the Rhone Delta, France, to test the applicability of a conceptual model of deltaic ecosystem function in a scenario of accelerated sea-level rise to a mediterranean delta which has been heavily altered by human activities. Natural pulsing events such as tides, river floods and storms cause sediment surfaces to maintain elevation in the face of relative sea level rise through the process of soil formation. These pulses also enhance ecosystem function through habitat creation, food production, materials transformation, water quality and storm and flood protection. …

Biology And Ecology Of The Anopheles Quadrimaculatus Sibling Species Complex In Louisiana., Cynthia Roxanne Rutledge

LSU Historical Dissertations and Theses

A polymerase chain reaction method for identifying individuals in the Anopheles quadrimaculatus Say sibling species complex was validated for wild mosquitoes from Louisiana and Mississippi. This method distinguished An. quadrimaculatus species A, B, C, and D by detecting species-specific differences in the 2nd internal transcribed spacer of ribosomal DNA and was 100% specific and 95% sensitive. A polymerase chain reaction assay that detects differences in the second internal transcribed spacer of ribosomal DNA was tested for its usefulness in identifying all immature stages of two representatives in the An. quadrimaculatus sibling species complex. The technique was successful in amplifying DNA …

Partial Sequencing Of A Balbiani Ring Gene And Development Of A Molecular Probe, Kerri Ann Kurzeja

Seton Hall University Dissertations and Theses (ETDs)

The Environmental Protection Agency is currently developing sediment quality criteria in order to protect the nation's water sources. In order to assist in the development of standards for the disposal of heavy metals, our laboratory is undergoing sediment toxicity studies on Chironomus riparius. It is an EPA approved test organism that spends most of its life in the sediment. Following a previous study (Cochrane et al., 1994), the organism's response to heavy metals will be monitored on the genetic level. Several genes, including a Balbiani ring (BR) gene, which was the focus of this thesis, will be studied to determine …

Modulation Of The Rat Potassium Channel Kv1.5, Daniel Benjamin Saal

Yale Medicine Thesis Digital Library

1. Kv1.5 is a delayed rectifier-type potassium channel. We have examined the localization of the channel protein using a polyclonal antibody against Kv1.5. This channel is expressed in numerous regions of the brain, primarily in glial cells. Its expression is particularly intense in the endfoot processes which abut the microvasculature of the brain. It is also expressed in the cell bodies and cellular processes in the pituitary.2. Immunoprecipitation of the Kv1.5 protein, from HEK 293 cells which were transformed with the Kv1.5 gene, revealed that the channel is phosphorylated and that treatment of cells with dibutyryl cyclic AMP (dibcAMP) or …

Teaching General Biology For Nonmajors Through Community Service Projects, Mary Wells Phillips

Higher Education

For many students, especially for the biology nonmajors, science is often one of the last courses they take before completing their degree. Often, these students enter my course with a previous "bad" experience from courses in high school or have developed anxieties regarding what science is all about. They are reluctant learners who frequently shy from questions and classroom discussions. Their own insecurities and presumed lack of knowledge frequently !eaves them floundering and confused. The message is, "I am here because I need 'x' number of science units before completing my degree."

A Transcription-Dependent Switch Controls Competence Of Adult Neurons For Distinct Modes Of Axon Growth, Deanna S. Smith, J.H. Pate Skene

Faculty Publications

Although maturing neurons undergo a precipitous decline in the expression of genes associated with developmental axon growth, structural changes in axon arbors occur in the adult nervous system under both normal and pathological conditions. Furthermore, some neurons support extensive regrowth of long axons after nerve injury. Analysis of adult dorsal root ganglion (DRG) neurons in culture now shows that competence for distinct types of axon growth depends on different patterns of gene expression. In the absence of ongoing transcription, newly isolated neurons can extend compact, highly branched arbors during the first day in culture. Neurons subjected to peripheral axon injury …

Predation By Nucella Lapillus (Linnaeus, 1758) On Littorina Obtusata (Linnaeus, 1758) And Mytilus Edulis (Linnaeus, 1758), Helena Matthews Cascon

Doctoral Dissertations

Prey preference and recognition by individuals of Nucella lapillus from 13 different populations from New England were studied, to determine if individuals of this species kept on a single prey diet develops a preference for this prey, and if prey availability affects prey recognition in this predator. Individuals from all 13 populations showed a preference for Mytilus edulis over Littorina obtusata in laboratory experiments, including those from a population that prey only on L. obtusata in the field. Individuals from another population were not able to recognize L. obtusata as a prey. N. lapillus kept in a diet of M. …

Molecular Characterization Of A Cytotoxic Porin Protein From Campylobacter Jejuni And Its Role In Campylobacteriosis, David John Bacon

Doctoral Dissertations

Campylobacter jejuni is a major cause of enteritis in developed and developing countries. A cytotoxic complex was isolated from organism-free filtrates of broth grown organisms by screening for activity in HEp-2 cells following high performance liquid chromatography using a combination of size exclusion and DEAE column chromatography. The toxin was found to coincide with a 45 kDa protein possessing an N-terminus sequence indicative of a bacterial outer membrane porin protein together with a high molecular weight carbohydrate which was determined to be lipopolysaccharide (LPS).

The carbohydrate portion of the LPS had reactivity for the lectins Galanthus nivalis agglutinin, Maakia amurensis …

Numerical Analysis For Blood Distribution In Complete Flow Cross-Section Microvascular Networks, Jewen Xiao

Doctoral Dissertations

As the blood flows through a bifurcation, the axisymmetric red blood cell concentration profile is skewed by plasma skimming. In the downstream segment of the bifurcation the concentration profile of red blood cells recovers symmetry by the red blood cell dispersion process.

In this study, the concentration convective equation, which models the red blood cell dispersion process, is solved with the method of finite differences in cylindrical coordinates. In the computation, a shear-induced diffusivity coefficient is used. The computed hematocrit ratios at the second bifurcation are compared with in vitro experimental data obtained from 50 $\mu$m serial trees with two …

Variation In Reproductive Success Within A Natural Population Of The American Toad (Bufo Americanus), Paulo Cascon

Doctoral Dissertations

The purpose of this study was to investigate if mating success and clutch size are good estimates of reproductive success in a population of Bufo americanus, through the study of the contribution of life history parameters to the variation in individual reproductive success. A B. americanus population that breeds in a pond located in Madbury, NH was studied during the 1994, 1995 and 1996 mating seasons. In 1995 and 1996 clutches were also studied and the larvae were used in laboratory and field experiments. The following fitness parameters were investigated: mating success, clutch and egg size, growth rate and survivorship …

A Biosystematic Monograph Of The Genus Nuphar Sm (Nymphaeaceae), Donald Jay Padgett

Doctoral Dissertations

The genus Nuphar (Nymphaeaceae) comprises 10 perennial species native to freshwaters of the Northern Hemisphere. This taxonomic assessment utilizes morphometric analyses, cladistic analyses of morphology, nuclear and chloroplast DNA sequences, evaluation of randomly amplified polymorphic DNA, and pollen fertility estimations. Evolutionary reconstructions position Nuphar at the base of the family, most closely allied to Barclaya. Phylogenetic estimates within Nuphar indicate two major evolutionary lines, largely congruent with present biogeographical distributions that indicate an Old World/New World divergence. Accordingly, the genus is subdivided into two sections, Nuphar and Astylata. Section Nuphar includes the type of the genus, N. lutea, as well …

Neuroethology Of The Swimming Behavior In The Pacific Nudibranch, Melibe Leonina, Kathryn Ann Lawrence

Doctoral Dissertations

Melibe leonina is a subtidal nudibranch which is found in association with eelgrass and kelp. Melibe swims when disturbed, or knocked off of its substrate, by slow lateral undulations. Swimming is stereotyped in its form and execution, and can be reliably reproduced in the laboratory. Swimming consists of phases: (1) withdrawal, (2) flattening, (3) lateral flexions, (4) unfolding and swinging and (5) termination. Swimming can be reliably elicited using 1M KCl or contact with the tube feet of the predatory seastar Pycnopodia helianthoides. The duration of a single swim cycle and the amplitude of swimming flexions remain relatively constant, however, …

Foraging Strategies Of Two Sympatric Lagomorphs: Implications Of Habitat Fragmentation, Douglas Foxall Smith

Doctoral Dissertations

I studied the effects of variation in food patch quality and predation risk on the foraging patterns and measures of foraging behavior of New England (S. transitionalis) and eastern (S. floridanus) cottontails, and their survivorship and weight change during these experiments. I then superimposed the results of these experiments onto real habitat patches to determine the amount of habitat each species could occupy and maintain similar survivorship. Finally, I measured an adaptation (eye size), and predator detection of both species in an effort to explain the difference in survival between S. floridanus and S. transitionalis.

In outdoor enclosures (5.7 x …

The Use Of An Artificial Light System To Assess The Influence Of Relative Light Change On Diel Activity Cycles Of Nymphs Of The Mayfly, Stenonema Modestum, In The Presence And Absence Of Predators, Annette L. Schloss

Doctoral Dissertations

A mechanism by which light controls diel changes in locomotor activity and surface location of mayfly nymphs (Stenonema modestum Banks), named the Stimulus-based Timing and Activity-Rate (STAR) Model, was tested. Nymph movements were video-recorded in time-lapse from underneath unglazed artificial substrates in a laboratory stream. Light/dark cycles were simulated using computer-controlled halogen lamps. Light increases and decreases were generated to maintain constant rates of relative light change throughout simulated twilight periods. Nymph locomotor activity and position on the substrate were measured in response to rate of light change. Experiments tested whether adaptation light intensity (10$\sp{-4}$ or 10$\sp{-6}$ W cm$\sp{-2}$), time …

Porin Proteins Of Salmonella Typhimurium Mediate Adherence To Macrophages, Robert Solomon Negm

Doctoral Dissertations

Salmonellosis continues to be a major infectious disease in both the United States and elsewhere. The outer membrane porin proteins (Omp) from Salmonella typhimurium play a key role in the initial adherence of this microorganism to murine macrophages and this mechanism is a critical event in the pathogenesis of infections. In this study macrophages were found to make contact with an OmpC-like protein of S. typhimurium and inhibition assays using the purified protein significantly reduced bacterial binding to macrophage. The ompC gene in a strain of S. typhimurium that is resistant to killing by macrophage was inactivated by transposon mutagenesis. …

Seasonal Changes In Gnrh Neurons And Effects Of Dietary Monoamine Precursors On The Hypothalamic-Gonadal Axis In House Sparrows (Passer Domesticus)., Christopher Andrew Meseke

LSU Historical Dissertations and Theses

Mechanisms modulating avian seasonal reproduction involve a complex interaction between exogenous environmental information and internal physiologic systems, such as functional changes in the hypothalamic-gonadal axis and changes in the influence of monoaminergic neurotransmitters on hypothalamic neuroendocrine cells. This project was undertaken to describe seasonal changes of the testes and immunoreactive-(ir)-gonadotropin-releasing hormone (GnRH) neurons in House Sparrows in southeastern Louisiana, and to examine the role of monoaminergic neurotransmitters in modulating seasonal reproduction through the use of dietary monoamine precursors. Testicular weights rapidly increased from February to March, peaked from April to July, when the seminiferous tubules were spermatagenically active and filled …