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The Physiological Role And Characterization Of Melanin Produced By Shewanella Algae Bry, Charles Edwin Turick

Doctoral Dissertations

Shewanella algae BrY is a Gram negative, facultative anaerobe isolated from the Great Bay Estuary of New Hampshire. This member of the gamma Proteobacteria demonstrates extensive versatility in the variety of terminal electron acceptors it uses for anaerobic respiration. Since the natural habitat of this non-fermenting organism is the oxiclanoxic interface of sediments, the ability to utilize various terminal electron acceptors contributes to its survival and growth. Among the terminal electron acceptors used by S. algae BrY are insoluble iron minerals. The transfer of electrons from a bacterial cell to an insoluble compound presents a strategic challenge for this organism. …

Identification Of Suppressors Of Spt10 That Affect Adh2 Expression In The Yeast Saccharomyces Cerevisiae, Bradley David Anderson

Doctoral Dissertations

Suppression of the effects of an spt10 mutation on ADH2 expression is a phenotype shared by a small number of genes involved in the regulation of gene expression. All six known suppressors of spt10 are either components of the CCR4-NOT Complex (CCR4, CAF1, NOT4), or have been shown to interact with the complex ( DBF2, SRB9, SRB10). This indicated that spt10 suppression may be characteristic of CCR4-like gene regulation. In this work, I conducted a screen for additional suppressors of spt10 at ADH2. The screen identified no less than ten complementation groups, including ADH2 and two known suppressors of spt10, …

Relational Learning For A Sustainable Future: An Eco -Spiritual Model, Mary Elizabeth Westfall

Doctoral Dissertations

We are facing unprecedented environmental challenges as we enter the new millennium as human choices and practices have repeatedly led to environmental degradation. Increasingly there are individuals and groups seeking to address this environmental crisis and move toward more sustainable patterns of living. But in order to make alternative choices it will be essential to draw upon the wealth and variety of human capabilities.

For nearly 350 years Western culture has looked to reason and rationality to provide truth and direction. The affective side of being human, feelings, intuition, love, care, wonder, mystery and hope have largely been devalued. In …

The Ecological, Behavioral, And Genetic Factors Influencing The Diversification Of Lake Malawi's Rock -Dwelling Cichlids, Patrick D. Danley

Doctoral Dissertations

Rapid evolutionary radiations provide insight into the fundamental processes involved in species formation. Here I examine the diversification of one such group, the rock-dwelling cichlid fishes of Lake Malawi (mbuna), which have radiated from a single ancestor into more than 200 species over the past 700,000 years. Through the examination of several molecular phylogenies, a phylogenetic history of the mbuna is proposed. The diversification of this group has proceeded in three major bursts of cladogenesis each of which has been dominated by a single selective force (selection on habitat preferences, trophic morphology, and male nuptial coloration, respectively). A divergence with …

Detection Of Giardia Lamblia And Cryptosporidium Parvum In The Eastern Oyster (Crassostrea Virginica) Harvested From The Great Bay Estuary, Kim Marie Stowell

Doctoral Dissertations

The Great Bay Estuarine system is being impacted by point source and nonpoint source pollution that affect shellfish quality. Many outbreaks of human gastroenteritis are potentially caused by the consumption of raw or undercooked oysters in which the protozoan pathogens, Giardia lamblia and Cryptosporidium parvum are present. The development of a rapid and sensitive technique to detect infectious protozoa in oysters is a necessity.

Immunofluorescence has been employed as a technique for the detection of these organisms in drinking water. Cross reactivity with algae and the production of false positive results limits the usefulness of this technique in environmental studies. …

The Effect Of Freeze /Thaw Temperature Fluctuations On Microbial Metabolism Of Petroleum Hydrocarbon Contaminated Antarctic Soil, Conrad George Leszkiewicz

Doctoral Dissertations

Petroleum contaminated soil exists at McMurdo Station in Antarctica. These soils were contaminated with historic releases of JP-8 jet fuel. Over time, there does not appear to have been significant reduction in the petroleum concentrations in these soils. This lack of reduction has been attributed to the extremely cold Antarctic environment and the lack of available moisture.

Cold temperatures and/or lack of moisture may not be the factors inhibiting biodegradation. Soil temperatures can exceed 20 degrees centigrade (°C) during the austral summer and melt water becomes available. However, the soil temperatures have also been reported to fluctuate rapidly. Swings of …

The Relationship Between Fruit Color Traits And Anthocyanin Genes In Diploid Fragaria, Chaoyang Deng

Doctoral Dissertations

A candidate gene approach was used to determine the likely molecular identity of the c locus (yellow fruit color) in Fragaria vesca, a diploid (2n = 2x = 14) strawberry. Using PCR with degenerate primer pairs, intron-containing segments of structural genes coding for the enzymes: chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanindin synthase (ANS), and one Del-like regulatory gene (RAN) in the anthocyanin biosynthetic pathway were amplified, cloned and sequenced. Intron length polymorphisms for each of these genes were detected among three diploid varieties: F. vesca Alpine variety 'Yellow Wonder' (YW) (Europe); DNIC, an …

Regulation Of Mammalian Photoreceptor Phosphodiesterase (Pde) By Its Noncatalytic Gaf Domains And Its Two Small Subunits, Gamma And Delta, Hongmei Mou

Doctoral Dissertations

cGMP phosphodiesterase (PDE) is the central effector of visual transduction in retinal rod photoreceptors. The overall goal of this work was to investigate the possible regulatory mechanisms of PDE in mammalian rod photoreceptors by its noncatalytic cGMP binding sites on the PDE catalytic dimer (Palphabeta), and by the interactions between the inhibitory Pgamma subunit and Palphabeta in their phosphorylated and non-phosphorylated states.

First, the binding of cGMP to the noncatalytic sites on membrane-associated PDE (PDE-M) and soluble PDE (PDE-S) was characterized. We found that PDE-M holoenzyme contains 2 non-identical high-affinity cGMP binding sites; one of the cGMP binding sites is …

Nitric Oxide And Cnidarian-Dinoflagellate Symbioses: Pieces Of A Puzzle, Henry G. Trapido-Rosenthal, Katherine H. Sharp

Arts & Sciences Faculty Publications

The presence of nitric oxide synthase (NOS) activity is demonstrated in the tropical marine cnidarian Aiptasia pallida and in its symbiotic dinoflagellate algae, Symbiodinium bermudense. Enzyme activity was assayed by measuring the conversion of arginine to citrulline. Biochemical characterization of NOS from Aiptasia was characterized with respect to cellular localization, substrate and cofactor requirements, inhibitors, and kinetics. In response to acute temperature shock, anemones retracted their tentacles. Animals subjected to such stress had lower NOS activities than did controls. Treatment with NOS inhibitors caused tentacular retraction, while treatment with the NOS substrate L-arginine inhibited this response to stress, as did …

Carbon And Oxygen Isotope Ratios In Rona Limestone, Romania, Dana Pop, Stela Cuna, Alexandru Hosu

KIP Articles

No abstract provided.

Introduction: Fear And Loathing Of Evolutionary Psychology In The Social Sciences, Daniel Leger, Alan Kamil, Jeffrey French

Psychology Faculty Publications

When one looks at the intellectual landscape of the modern university, at the scholarly and scientific interests of its faculty, the panorama is seamless. There are no discontinuities. The interests of physicists transmogrify into those of chemists, those of chemists into those of biologists, and so on. The lines, the divisions, between departments have been created out of administrative, not intellectual, necessity.

Computer Aided Learning Environment For Biology, Pek Hin Foong

Student Works (2000-2009)

Traditional learning on biology requires of memory rather than understanding. As better educational technology emerges, we are able to utilise the computer as an important tool in learning. Many educational and pedagogical issues, particularly in the field or Artificial intelligence are looked at to help consider a good design for a computer learning tool. Existing computer aided learning materials are also studied to pinpoint their better features and incorporate them into the learning tool. A learning tool is proposed for effective learning in relating facts, rules, text and graphics. This system will have a Study Section containing notes that incorporates …

Pathobiology Of Streptococcus Iniae Infections In Cultured Tilapia., Alvin Cyril Camus

LSU Historical Dissertations and Theses

Streptococcus iniae was first isolated in 1972 from an Amazon River dolphin. It reappeared as a fish pathogen in Japan several years later. Since then it has steadily increased in incidence and host range worldwide, and is a known zoonotic agent. In the United States it is the most significant pathogen affecting growth of tilapia aquaculture. Histopathologic descriptions are incomplete and little is known concerning pathogenesis of the disease or virulence mechanisms of the organism. A composite of lesions was compiled from diseased tilapia evaluated by the Aquatic Animal Disease Diagnostic Laboratory, Louisiana State University from 1995--2001. In common with …

Isolation And Characterization Of A Rhodobacter Capsulatus Hemc Mutant., Karen Coleman Sullivan

LSU Historical Dissertations and Theses

Rhodobacter capsulatus, a purple, nonsulfur photosynthetic bacterium, uses the tetrapyrrole pathway to synthesize four end products: heme, bacteriochlorophyll, vitamin B12, and siroheme. This laboratory has focused on the regulation of the common pathway leading from aminolevulinate to protoporphyrin IX in R. capsulatus. The common portion of the pathway is regulated up to 100-fold by changes in oxygen tension. Research on the regulation of this pathway has been hampered due to a lack of mutants. Until now, the only mutants isolated which block heme production are hemA mutants, which lack aminolevulinate synthase. Since R. capsulatus lacks a cytochrome-independent growth mechanism, mutations …

The Role Of Immunity In Resistance Of Gulf Coast Native Sheep To Haemonchus Contortus Infection., Maria Teresa Pena

LSU Historical Dissertations and Theses

Haemonchus contortus is a serious constraint for sheep production in tropical and subtropical regions of the world. The use of genetically resistant animals is a promising alternative for controlling nematode infections without relying on the use of anthelmintics. Extensive epidemiological studies demonstrated that Gulf Coast Native sheep are naturally resistant to H. contortus infection, but the mechanism underlying this resistance is not well known. The main purpose of this research was to define the components of the immune response that may be involved in resistance of GCN to H. contortus infection. Three studies were conducted. In the first study, a …

Factors Affecting Community Structure Of Mangroves Associated With Point Bars And Islands In A Costa Rican Estuary., Patricia Delgado-Sanchez

LSU Historical Dissertations and Theses

A conceptual model of relationships between mangrove community structure and their physico-chemical environment is developed for point bars and islands in the Tempisque-Bebedero estuarine system, Pacific coast, Costa Rica. The model identifies key variables whose relationships to mangrove forest structure are the focus of extended field and mesocosm studies. Point bars and islands are very dynamic features constantly modified by hydrology and sediment dynamics. In the Tempisque-Bebedero system, they are additionally modified by extensive agricultural activities. High riverine sediment loads, associated with irrigation and seasonal wind-driven resuspension, result in significantly higher sediment deposition in lower intertidal zones; upper intertidal zones …

Systemic And Colonic Hemodynamic And Vasomotor Responses To Adenosine Triphosphate In Horses., Joanne Tetens

LSU Historical Dissertations and Theses

Clinically healthy horses were instrumented to measure hemodynamic, metabolic, hematologic, and serum biochemical variables and monitor clinical signs during and after IV infusion of ATP-MgCl2. Conscious horses were administered ATP-MgCl2 (0.05 mg ATP/kg body weight/min; 0.05 mg/kg/min increments; maximum rate-1.0 mg/kg/min), which caused a rate-dependent increase in cardiac output, decrease in systemic vascular resistance, and mild pulmonary hypertension. The maximal safe infusion rate was 0.3 mg ATP/kg body weight/min. Anesthetized horses administered ATP-MgCl2 (0.1 to 1 mg/kg/min; 0.1 mg/kg/min increments) developed a rate-dependent decrease in systemic and colonic vascular resistance via vasodilatation. In conscious horses administered lowdose endotoxin, ATP-MgCl2 (dose-100 …

Red Morningglory (Ipomoea Coccinea L.) And Sugarcane Response To Soil-Applied Herbicides., Blaine Joseph Viator

LSU Historical Dissertations and Theses

Laboratory and greenhouse studies were conducted to determine if reported red morningglory (Ipomoea coccinea L.) control failures with atrazine in sugarcane are due to triazine-resistant mutants. Terminal fluorescence of leaf material from locations with and without a history of atrazine use increased after treatment with atrazine, indicating electron transport inhibition and hence, triazine susceptibility. Postemergence (POST) application of atrazine controlled plants from all populations at least 99%, supporting findings of the fluorescence assay. A field study was conducted to evaluate red morningglory control and sugarcane injury with herbicides applied at layby. At 45 days after treatment (DAT), control with sulfentrazone …

Metal Partitioning Among Tissues And Exoskeleton Of Palaemonetes Pugio And Its Role In Depuration And Trophic Transfer., Kristen Annette Keteles

LSU Historical Dissertations and Theses

The objective of this dissertation was to determine the partitioning of Cu, Zn and Cd between tissues and exoskeleton of the grass shrimp, Palaemonetes pugio Holthius, and to examine the consequences of this association. The role of the exoskeleton in the potential for depuration of metals through ecdysis was examined first. The portion eliminated with the exuviae varied for each metal; 11% Cu, 18% Zn, and 26% Cd of the total intermolt body burden was associated with exuviae. Some fraction of Cu and Cd in the exoskeleton was likely reabsorbed before molting but excess Zn was likely depurated through excretion. …

The Across-Shelf Distribution Of Larval, Postlarval And Juvenile Fishes Collected At Oil And Gas Platforms And A Coastal Jetty Off Louisiana West Of The Mississippi River Delta., Frank Joseph Hernandez Jr

LSU Historical Dissertations and Theses

A cross-shelf transect of three petroleum platforms and a coastal rock jetty (another hard-substrate, artificial habitat) in the northcentral Gulf were sampled to examine the role that oil and gas platforms (hard substrate habitat) may play in the early life history stages of reef-dependent and reef-associated fishes. The ichthyoplankton and juvenile fish assemblages were sampled at Green Canyon 18 (GC 18; 230 m depth, shelf slope); Grand Isle 94 (GI 94; 60 m depth, mid-shelf); and South Timbalier 54 (ST 54; 20 m depth, inner shelf) with passive plankton nets and light-traps and at a coastal rock jetty (Belle Pass; …

Systematics Of Neotropical Satyrine Butterflies (Nymphalidae: Satyrinae: Euptychiina) Based On Larval Morphology And Dna Sequence Data And The Evolution Of Life History Traits., Debra Lynne Murray

LSU Historical Dissertations and Theses

Although satyrine butterflies (Lepidoptera: Nymphalidae: Satyrinae) are highly diverse and found worldwide in most terrestrial habitats, they have received little attention from systematists. This research focuses on one of the largest satyrine groups, the euptychiines, found from central United States to Argentina, with the greatest diversity in the Amazon. The subtribe Euptychiina has a troubled taxonomic history. Most genera were erected without diagnoses and placed within the subtribe without being examined. Before this project was initiated, little was known of their basic biology and morphology. Therefore, considerable attention was given to this area in my research. I describe the larvae …

Two Splice Variants Of Nopp140 In Drosophila Melanogaster., John Mark Waggener

LSU Historical Dissertations and Theses

The activities of non-ribosomal nucleolar proteins are now understood to be important for the normal functions of both nucleoli and C&barbelow;ajal B&barbelow;odies (CBs). Although these proteins have been studied extensively in other eukaryotes, knowledge of non-ribosomal nucleolar proteins in Drosophila melanogaster lags far behind. The n&barbelow;ucleo&barbelow;lar p&barbelow;hosphop&barbelow;rotein of 140 kDa (Nopp140) may function to shuttle box C/D and box H/ACA s&barbelow;mall n&barbelow;ucleo&barbelow;lar (sno)RNAs from the nucleus to the nucleolus, where they function in the 2 '-O-methylation and pseudouridylation of rRNA, respectively. Nopp140 homologues have been described in rat, human, Xenopus laevis , and yeast. This dissertation describes the cloning of …

Lipopolysaccharide Receptor, Toll -Like Receptor 4, Mediated Signaling Pathways Leading To Cyclooxygenase-2 Expression In Murine Macrophages., Sang Hoon Rhee

LSU Historical Dissertations and Theses

Genetic evidence indicating that Toll-like receptor 4 (TLR4) is the lipopolysaccharide (LPS) receptor in mice was reported. However, biochemical evidence that murine TLR4 confers LPS responsiveness has not been convincingly demonstrated. Inducible cyclooxygenase (COX-2) is selectively expressed in LPS-stimulated macrophages in part mediated through activation of NFkappaB. Thus, we determined whether murine TLR4 confers LPS responsiveness as evaluated by activation of NFkappaB and COX-2 expression. Expression of the constitutively active form (DeltaTlr4) of TLR4 in murine macrophage cell line (RAW 264.7) is sufficient to activate NFkappaB and COX-2 expression and to stimulate prostaglandin E2 synthesis. The truncated form [DeltaTlr4 (P712H)] …

Epidemiology Of Salmonella In The Green Iguana (Iguana Iguana)., Mark Anthony Mitchell

LSU Historical Dissertations and Theses

The incidence of iguana-associated salmonellosis reported in humans during the 1990's is a public health concern. This research is the first attempt to describe the epidemiology of Salmonella in the green iguana. Seasonal prevalence of Salmonella in green iguanas and their environment were estimated at a commercial iguana farm in El Salvador. The prevalence of Salmonella was lower in adult iguanas (44%) than in yearlings (50%) (Odds ratio (OR): 0.77, 95% Confidence Intervals (CI): 0.6--0.96) and higher in male iguanas (50%) than females (41%) (OR: 1.5, 95% CI: 1.2--1.8). Salmonella recovery was lower in the fall (41%) sampling period than …

Meiofaunal Colonization Of Artificial Substrates., Nazan Atilla

LSU Historical Dissertations and Theses

Meiofaunal colonization of artificial substrates was investigated in a shallow estuarine embayment. Meiofauna colonized various artificial substrates rapidly, at a rate of 1000 individuals collector-1 day -1 regardless of season, suggesting that high abundances of meiofauna commonly exist in the water column. These water-column meiofauna may be important in fish diets and may serve as a dispersing pool that aids recolonization after disturbance events. Colonization of artificial substrates by transient meiofauna of unknown origin(s) occurred through the water column. To determine the source of meiofauna colonizing artificial substrates, sediment and pier-piling meiofauna were sampled and compared to artificial-substrate colonists. Assemblages …

A Drifter Study Of Advection, Deformations, And Patch Variances With Application To Larval Transport And Dispersal In Barataria Bay, Louisiana., Terry L. Schaefer

LSU Historical Dissertations and Theses

Field studies were conducted to characterize flow fields and their effect on larval transport and retention within Barataria Bay, Louisiana. Drifter tracking and passive larval sampling was conducted monthly during the spring and summer months from 1994 through 1996. Fifteen drifter tracking sessions were conducted over full tidal cycles (diurnal). Drifter positions were determined approximately every thirty minutes using a GPS receiver. A spline interpolation was used to estimate drifter positions at synchronous five-minute intervals. An analytical methodology of Okubo and coworkers was used to compute deformations; and changes in patch variances from the drifter positions. Mean tidal advection and …

Ecological Structure Of Estaurine Fish Communities: Habitat Linkages Among Dominant Species Groups In Terminos Lagoon, Mexico., Ana Laura Lara-Dominguez

LSU Historical Dissertations and Theses

Terminos Lagoon in the southern Gulf of Mexico has 5 ecological subsystems: (1) fluvial lagoon systems (FLS) with permanent river discharge, low salinity, high turbidity and nutrients. (2) Central basin (CB) between marine and river conditions, intermediate salinity and variable transparency. (3) Inner littoral of Carmen Island (ILCI) with strong marine influence, high transparency and extensive seagrass meadows. (4) Carmen inlet (Estero Pargo, ESP) with a net outflow of water and high turbidity. (5) Puerto Real inlet (PR) with a net inflow of waters, high transparency and seagrasses. During a 15-month sampling, 13,691 individuals of 79 different species were collected …

T -Cell Cytokines And Equine Nematode Infections., Jenifer Dee Edmonds

LSU Historical Dissertations and Theses

To address the role of parasites on subsequent antigenic challenge, humoral, lymphoproliferative and cytokine responses to a single intramuscular injection of keyhole limpet haemocyanin (KLH) were compared between groups of ponies with high, medium or low gastrointestinal parasite burdens. Heavy and moderately parasitised animals showed a trend towards reduced KLH-specific lymphoproliferation and reduced antigen specific total immunoglobulin, IgG(T) and IgA compared to lightly parasitised ponies. The peripheral blood mononuclear cells (PBMC) from medium and heavily parasitised ponies also had significantly lower levels of IL-4. These data indicate that heavily parasitised animals have uniformly decreased cellular and humoral immune responses to …

Body Condition, Leptin, And Reproductive Characteristics In Horses., Laura Roland Gentry

LSU Historical Dissertations and Theses

A series of experiments was conducted to gain a better understanding of the effects of nutrition and hormonal manipulation on the reproductive processes of the horse. In Experiment 1, body condition score (BCS) and ultrasonic backfat measurements were highly correlated in mares, especially over the tailhead area. In Experiment 2, high BCS (HBCS) mares continued to ovulate during the winter anestrous period, whereas low BCS (LBCS) mares went deeply anestrous. Daily hormone concentrations were not affected by BCS, however, responses to hormonal challenges indicated cyclicity in HBCS mares and reproductive quiescence in LBCS mares. In Experiment 3, treatment of average …

Statistical And Simulation Modeling Of Brown Shrimp Population Dynamics In The Northern Gulf Of Mexico., Heather Lynn Haas

LSU Historical Dissertations and Theses

This dissertation used statistical and simulation modeling to examine population dynamics of brown shrimp, Penaeus (Farfantepenaeus ) aztecus. Brown shrimp are ideal to use in examining recruitment because shrimp represent a common life history strategy, because they are commercially important, and because there are extensive data available. In the first section of this dissertation, I used long-term monitoring data to examine correlative relationships between annual, stage-specific abundance estimates and environmental factors. Criticisms of traditional correlative studies were addressed by using a spatially and temporally-extensive dataset, by comparing stepwise multiple regression to Bayesian model averaging, and by investigating nonlinear relationships with …