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Identification And Characterization Of A 14-Kilodalton Brucella Abortus Protein Reactive With Antibodies From Naturally And Experimentally Infected Hosts And T Lymphocytes From Experimentally Infected Balb/C Mice, R. L. Chirhart-Gilleland, M. E. Kovach, P. H. Elzer, S. R. Jennings, R. M. Roop Jan 1998

Identification And Characterization Of A 14-Kilodalton Brucella Abortus Protein Reactive With Antibodies From Naturally And Experimentally Infected Hosts And T Lymphocytes From Experimentally Infected Balb/C Mice, R. L. Chirhart-Gilleland, M. E. Kovach, P. H. Elzer, S. R. Jennings, R. M. Roop

Faculty Publications

A low-molecular-weight recombinant Brucella abortus protein reactive with antibodies from a variety of naturally and experimentally infected hosts and T lymphocytes from experimentally infected mice was identified and given the designation BA14K. The gene encoding BA14K was cloned and characterized, and the predicted amino acid sequence of this immunoreactive protein showed no significant homology with previously described proteins. Sequences homologous to the cloned fragment encoding BA14K were identified by Southern blot analysis of genomic DNAs from representatives of all of the currently recognized Brucella species. Studies employing BA14K should contribute to our efforts to better understand the antigenic specificity of …

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The Physiological And Psychological Responses To Submaximal Exercise At Different Times In Renal Disease Patients., Marta Amaral-Melendez Jan 1998

The Physiological And Psychological Responses To Submaximal Exercise At Different Times In Renal Disease Patients., Marta Amaral-Melendez

LSU Historical Dissertations and Theses

This study investigated cardiorespiratory, hematological, and psychological responses to acute submaximal exercise, and recovery in end stage renal disease patients. Five African-American males on hemodialysis, were randomly assigned to three exercise treatments (30 minutes on the treadmill at 60% VO$\sb2$ peak): pre dialysis (2 hours before), post dialysis (1 hour after), and off dialysis (24 hours after last dialysis). The cardiorespiratory (CR) variables were: ventilation (V$\sb{\rm E}$), oxygen consumption (VO$\sb2$), carbon dioxide production (VCO$\sb2$), respiratory exchange ratio (R), and kilocalories (KCAL/min). The hematological variables were: blood urea nitrogen (BUN), creatinine (Cr), albumin (Al), total protein (Tp), glucose (Gl), sodium (Na$\sp{++}$), …

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Detection Of Mechanisms Of Profenofos Resistance In The Tobacco Budworm, Heliothis Virescens (F.)., John Ambrose Harold Jan 1998

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 …

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A Conceptual And Empirical Approach For Valuing Biodiversity: An Estimate Of The Benefits Of Plant And Wildlife Habitat Preservation In The Tensas River Basin., Jack Coburn Isaacs Jan 1998

A Conceptual And Empirical Approach For Valuing Biodiversity: An Estimate Of The Benefits Of Plant And Wildlife Habitat Preservation In The Tensas River Basin., Jack Coburn Isaacs

LSU Historical Dissertations and Theses

This research estimated the passive use value of local species biodiversity in the Tensas River basin, a section of the Lower Mississippi River Valley. This research employed the contingent valuation method in eliciting willingness to pay for biodiversity conservation using the habitat needs of an umbrella species as a basis for valuation. This study designed and implemented the Lower Mississippi Valley Plant and Wildlife Survey for primary data collection. The sample included 1,351 households drawn from a hunting permit lottery conducted by the Tensas River National Wildlife Refuge and 3,044 households drawn at random from Louisiana, Arkansas, and Mississippi. The …

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Purification And Antioxidant Properties Of Rice Bran (Gamma)-Oryzanol Components., Zhimin Xu Jan 1998

Purification And Antioxidant Properties Of Rice Bran (Gamma)-Oryzanol Components., Zhimin Xu

LSU Historical Dissertations and Theses

A high purity $\gamma$-oryzanol was obtained from crude rice bran oil using a normal phase preparative scale HPLC. It was used in implementing a reverse phase HPLC method for separating each individual component of $\gamma$-oryzanol present in rice bran oil. Ten fractions were isolated in the reverse phase HPLC method. The ten components of $\gamma$-oryzanol were identified. Three of these, cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, and campesteryl ferulate, were major components of $\gamma$-oryzanol. The yield of $\gamma$-oryzanol without saponification was significantly higher than that with saponification in solvent extraction. The solvent mixture with 50% hexane and 50% isopropanol (v/v.) at …

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The Structure And Stability Of Selected, 2-D Self-Gravitating Systems., Saied W. Andalib Jan 1998

The Structure And Stability Of Selected, 2-D Self-Gravitating Systems., Saied W. Andalib

LSU Historical Dissertations and Theses

Models of radially and vertically extended self-gravitating disks orbiting around a central point mass are relevant to the dynamics of astrophysical systems and are thought to be common in many galaxies. The gravity driven instabilities in these accretion disks are now believed to be a possible mechanism for star formation via disk fragmentation (Shu, Adams, & Lizano 1987, Adams, Rudin & Shu 1989; Christodoulou 1995). We quantify these regions of instability using a simple toroidal model of an accretion disk. We choose the two-dimensional axisymmetric, incompressible slender disks to examine and map out these principal modes of gravity driven instabilities. …

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Identification Of Antigens Of Edwardsiella Ictaluri, The Causative Agent Of Enteric Septicemia Of Catfish (Esc)., Michelle Marie Moore Jan 1998

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 …

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Structural Characterization Of Beta Carbonic Anhydrases From Higher Plants., Michael H. Bracey Jan 1998

Structural Characterization Of Beta Carbonic Anhydrases From Higher Plants., Michael H. Bracey

LSU Historical Dissertations and Theses

It is the goal of this dissertation research to reveal some aspects of the physical nature of spinach carbonic anhydrase as a representative $\beta$CA using the techniques of sequence comparison, molecular biology, and biophysics. Though both $\alpha$ and $\beta$ carbonic anhydrases are zinc dependent metalloenzymes, it is clear that the two isoforms do not adopt the same mechanism for coordinating the active site metal. While $\alpha$CA binds zinc through three histidine ligands, $\beta$CA cannot due to a lack of evolutionarily conserved histidines. Instead, the $\beta$ family has adopted a ligand scheme incorporating a single histidine and two cysteines. This has …

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An Investigation Of The Relationship Between Teachers' Orientations In Reading Process And Instruction: Four Case Studies., Carrice Lou Cummins Jan 1998

An Investigation Of The Relationship Between Teachers' Orientations In Reading Process And Instruction: Four Case Studies., Carrice Lou Cummins

LSU Historical Dissertations and Theses

The beliefs that teachers hold about how children learn are often reflected in the instructional practices they use to help children become readers. The purpose of this study was threefold: (a) to identify teachers' beliefs regarding how reading takes place and how reading develops, (b) to examine the instructional reading practices implemented in teachers' classrooms, and (c) to explore the relationships between teachers' theoretical beliefs and their instructional practices in providing appropriate reading instruction. Qualitative methods informed this study by providing case studies of four primary grade teachers, giving detailed accounts of their theoretical beliefs--process and instruction. Two of the …

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Supplemental Organic Chromium For Dairy Calves., Christopher L. Depew Jan 1998

Supplemental Organic Chromium For Dairy Calves., Christopher L. Depew

LSU Historical Dissertations and Theses

In Exp. 1, 42 calves were fed milk replacer and then starter either with or without 1 ppm supplemental chromium (Cr) as Cr-picolinate. Neither Cr nor sex affected growth performance. With the exception of plasma nonesterified fatty acid concentrations (NEFA), weekly plasma metabolites were not affected by Cr or sex. Pre- and postfeeding plasma NEFA concentrations were lower in Cr-fed calves, but were not affected by sex. AU calves seemed to become less insulin sensitive with age, as plasma glucose became lower and insulin higher as calves became older. During i.v. glucose tolerance tests (IVGTT), calves cleared glucose faster at …

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An Analysis Of Factors Influencing The Teaching Of Biological Evolution In Louisiana Public Secondary Schools., Donald Wayne Aguillard Jan 1998

An Analysis Of Factors Influencing The Teaching Of Biological Evolution In Louisiana Public Secondary Schools., Donald Wayne Aguillard

LSU Historical Dissertations and Theses

Louisiana public school biology teachers were surveyed to investigate their attitudes toward biological evolution. A mixed method investigation was employed using a questionnaire and open-ended interviews. Results obtained from 64 percent of the sample receiving the questionnaire indicate that although teachers endorse the study of evolution as important, instructional time allocated to evolution is disproportionate with its status as a unifying concept of science. Two variables, number of college courses specifically devoted to evolution and number of semester credit hours in biology, produced a significant correlation with emphasis placed on evolution. The data suggest that teachers' knowledge base emerged as …

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Influence Of Diet And Genetic Strain On Desirable Flavors In Farm-Raised Catfish., Carol Ann Kelly Jan 1998

Influence Of Diet And Genetic Strain On Desirable Flavors In Farm-Raised Catfish., Carol Ann Kelly

LSU Historical Dissertations and Theses

This farm-raised catfish quality study measured desirable flavor attributes, Chickeny, Nutty, Fat Complex, Corn, Sweet, with the objective to determine effects of feed ingredients, time-on-diet and genetic strain. Overall flavor impact differences were tested by triangle tests. The diets were Casein-base reference feed by itself or partially substituted with: 10% catfish meal, 10% meat and bone meal, 10% rice bran, or 3% menhaden oil and commercial feed formulation. Fish were grown indoors to minimize environmental flavors for 70, 160, 210 and 318 days. The genetic strains evaluated were channel, albino channel, blue, hybrid channel x blue, and black bullhead catfish. …

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Airbirds: Adaptative Strategies To The Aerial Lifestyle From A Life History Perspective., Manuel Marin-Aspillaga Jan 1998

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 …

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Beta-Carotene And Exercise Performance: Effects On Race Performance, Oxidative Stress, And Maximal Oxygen Consumption., Kim Edward Leblanc Jan 1998

Beta-Carotene And Exercise Performance: Effects On Race Performance, Oxidative Stress, And Maximal Oxygen Consumption., Kim Edward Leblanc

LSU Historical Dissertations and Theses

There is evidence in the literature that suggests a possible worthwhile role of antioxidants during athletic endeavors and exercise performance. Several studies have evaluated the antioxidant ability of beta-carotene and demonstrated a beneficial influence. However, these studies have investigated beta-carotene's effects within an antioxidant mixture which included other antioxidant vitamins. Consequently, this study attempted to isolate the antioxidant role of beta-carotene during exercise. Three parameters of beta-carotene influence were measured using eleven well-trained runners: serum malondialdehyde (MDA) concentration (a marker of free radical generation), 5000 meter race performance, and maximum oxygen consumption (VO2max). Subjects were tested using a double-blinded cross-over …

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Representations Of Class, Gender, Race, And Religion In The Novels Of Somerville And Ross, 1894-1925., Nicole Pepinster Greene Jan 1998

Representations Of Class, Gender, Race, And Religion In The Novels Of Somerville And Ross, 1894-1925., Nicole Pepinster Greene

LSU Historical Dissertations and Theses

This dissertation examines how the Anglo-Irish writers, Edith Somerville and Martin Ross (nee Violet Martin), attempt to define themselves and others in terms of class, gender, race, and religion at a time when self-definition itself is an act of resistance and defiance. This analysis focuses on four novels: The Real Charlotte (1894), co-authored by Somerville and Ross, Mount Music (1919), An Enthusiast (1921), and The Big House of Inver (1925), written by Somerville alone. Since these novels were composed during the most chaotic years of Irish history when the country was in transition from the status of a colonial dependency …

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Texts And Talk: A Close Look At Gender In Literature Discussion Groups., Peggy Sue Rice Jan 1998

Texts And Talk: A Close Look At Gender In Literature Discussion Groups., Peggy Sue Rice

LSU Historical Dissertations and Theses

This study investigated discourse according to gender-related patterns of eight sixth-grade students (four boys and four girls) as they discussed four realistic fiction short stories in peer-led discussion groups that alternated between same-sex and mixed-sex group compositions. Descriptive data were analyzed according to the constant comparative method of analysis. Quantitative analysis was used to determine discourse patterns in terms of frequency. Data were analyzed to answer the following questions: (1) Will the discourse patterns vary when the students discuss their responses in same-sex groups and mixed-sex groups? If so, in what ways will they vary? (2) Will gender differences be …

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Managing Promises And Marketing Activities In The Cultivation Of Long-Term Relationship Commitment: The Development Of A Model For The Services Industries., John Michael Weber Jan 1998

Managing Promises And Marketing Activities In The Cultivation Of Long-Term Relationship Commitment: The Development Of A Model For The Services Industries., John Michael Weber

LSU Historical Dissertations and Theses

The concept of promises is important with services, because they can represent some tangible aspect of the service organization upon which the customer can develop expectations and partially evaluate the performance of the organization. It is also important to examine the marketing processes (external, internal, and interactive) the organization utilizes and the consumer can participate in, because these processes act as the communication avenue for the promises. Finally, it is important to evaluate the promises and marketing processes from the perspective of the consumer in order to determine the consumer's expectations, perception of service personnel, evaluations of actual service delivery, …

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Evaluation Of Chemical Treatments And Intrinsic Factors That Affect The Mutagenic Potential Of Aflatoxin B1-Contaminated Corn., Armando Burgos-Hernandez Jan 1998

Evaluation Of Chemical Treatments And Intrinsic Factors That Affect The Mutagenic Potential Of Aflatoxin B1-Contaminated Corn., Armando Burgos-Hernandez

LSU Historical Dissertations and Theses

In the present project the use of ammoniation and fermentation as an integrated process was studied in order to give aflatoxin-contaminated corn an alternative use. Aflatoxin-contaminated corn can be fermented to obtain fuel alcohol and decontaminated distiller's dried solid grains (DDSG) can be used for animal feed. The efficacy of a fermentation process, with the inclusion of ammonium persulfate, for the decontamination of aflatoxin B$\sb1$-contaminated yellow corn was studied, as well as the effect of peroxides on the ethanol production. Addition of 2.0% ammonium persulfate decreased the aflatoxin B$\sb1$ levels by 87%. Peroxides did not have an effect on ethanol …

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The Effects Of Pah-Contaminated Sediments On Benthic-Feeding Fishes And Their Associated Prey., Candace Gay Hinkle-Conn Jan 1998

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, …

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Serological And Molecular Biological Studies Of Marine Predator-Prey Systems., Marilyn J. Hoyt Jan 1998

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 …

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Aflatoxin B(1) And Fumonisin B(1) Co-Contamination: Interactive Effects, Possible Mechanisms Of Toxicity, And Decontamination Procedures., Rebeca Lopez-Garcia Jan 1998

Aflatoxin B(1) And Fumonisin B(1) Co-Contamination: Interactive Effects, Possible Mechanisms Of Toxicity, And Decontamination Procedures., Rebeca Lopez-Garcia

LSU Historical Dissertations and Theses

The current study evaluated interactions between the mycotoxins aflatoxin B$\sb1$ (AFB$\sb1$) and fumonisin B$\sb1$ (FB$\sb1$) in pure systems as well as in corn. During storage at 25$\sp\circ$C with high moisture (ca. 50%), corn contaminated with Aspergillus flavus (L13) and/or Fusarium moniliforme (A00102) presented different aflatoxin and fumonisin levels. Toxin production/degradation varied over storage time (0-45 days). Evaluation of the mutagenicity of unifungal or bifungal corn extracts with the Salmonella/microsomal assay (tester strains TA-100 and TA-98) with metabolic activation (S9) showed positive mutagenic responses. Different ratios of pure AFB$\sb1$/FB$\sb1$ produced divergent mutagenic responses (tester strains TA-100 and TA-98) with S9. The …

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The Impact Of Specialist And Multiple Dealer Market Structures On Intraday Price Formation And Bid-Ask Spread Components., David Michael Michayluk Jan 1998

The Impact Of Specialist And Multiple Dealer Market Structures On Intraday Price Formation And Bid-Ask Spread Components., David Michael Michayluk

LSU Historical Dissertations and Theses

This dissertation investigates specialist and multiple dealer markets. In the first of four essays, simultaneous trading in two market structures on the Paris Bourse is used to evaluate intraday price formation. Specialists are found to exacerbate the end of day price rise. Stock volatility and bid-ask spreads are found to be larger when a specialist is present, in contrast to existing literature that compares market structures on different exchanges. The second essay estimates the components of the bid-ask spread and trade execution costs on the Paris Bourse. Estimates of the adverse selection cost component do not resolve the conflicting findings …

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Development And Assessment Of A Property Rights-Based Measure Of State Regulatory Climate., Ferdinand Francis Wirth Iii Jan 1998

Development And Assessment Of A Property Rights-Based Measure Of State Regulatory Climate., Ferdinand Francis Wirth Iii

LSU Historical Dissertations and Theses

States implement many of the environmental laws enacted during the last thirty years. A key policy issue is the effect of differences in state institutions and environmental policies on the location of livestock agriculture. There is widespread belief that the stringency of state environmental regulations, known as regulatory climate, is an important factor influencing the location, growth and expansion decisions of livestock agriculture. Existing regulatory climate measures are not tailored to agriculture, and their use has given mixed results. Conceptual and empirical models were developed for the U.S. aquaculture industry, based on elements of public choice and firm location theories …

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Arthur Miller In Montreal: Cultural Transfer Of American Plays In Quebec (1965-1997)., Bernard Lavoie Jan 1998

Arthur Miller In Montreal: Cultural Transfer Of American Plays In Quebec (1965-1997)., Bernard Lavoie

LSU Historical Dissertations and Theses

In the 1960s, American plays presented in Montreal were translated in France; the following decade saw the first of American plays translated or adapted in Quebec. In the 1980s, the translative practices employed in the seventies proved the dominant mode. In the 1990s, only exceptionally has an American play been presented in a translation originating outside of Quebec. It is now the rule that all foreign plays produced in Quebec are translated in the Quebecois idiom. This translative situation has stabilized, and the translation of American plays into Quebecois reflects an established practice. The tracing and analysis of this translative …

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Hematite And Calcite Coatings On Fossil Vertebrates, B. A.O. Huiming, Paul L. Koch, Robert P. Hepple Jan 1998

Hematite And Calcite Coatings On Fossil Vertebrates, B. A.O. Huiming, Paul L. Koch, Robert P. Hepple

Faculty Publications

Hematite coatings are common on vertebrate fossils from Paleocene/Eocene paleosol deposits in the Bighorn Basin, Wyoming. In general, hematite coatings are found only on fossils and are limited to soils exhibiting hydromorphic features and moderate maturity. Pétrographie and isotopic evidence suggests that hematite and micritic calcite formed at nearly the same time in a pedogenic environment, whereas sparry calcite formed later at greater burial depths. The parent material of paleosols is rich in iron, supplying an ample source of iron for hematite formation. Decomposition of animal tissues around bones may enhance the weathering of iron-bearing minerals in soils surrounding carcasses, …

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Molecular Cloning And Hormonal Regulation Of A Murine Epididymal Retinoic Acid-Binding Protein Messenger Ribonucleic Acid, Jean Jacques Lareyre, Weng Li Zheng, Guang Quan Zhao, Susan Kasper, Marcia E. Newcomer, Robert J. Matusik, David E. Ong, Marie Claire Orgebin-Crist Jan 1998

Molecular Cloning And Hormonal Regulation Of A Murine Epididymal Retinoic Acid-Binding Protein Messenger Ribonucleic Acid, Jean Jacques Lareyre, Weng Li Zheng, Guang Quan Zhao, Susan Kasper, Marcia E. Newcomer, Robert J. Matusik, David E. Ong, Marie Claire Orgebin-Crist

Faculty Publications

A complementary DNA encoding the mouse epididymal secretory protein MEP 10 (mouse epididymal protein 10) was cloned and is now renamed murine epididymal retinoic acid binding protein (mE-RABP). The analysis of the predicted primary amino acid sequence showed that mE-RABP has a 75% identity with rat ESP I (epididymal secretory protein I), another epididymal retinoic acid-binding protein. The homology strongly suggests that mE-RABP is the mouse orthologue of rat ESP I. A computer analysis of the predicted three- dimensional structure confirmed that mE-RABP can accommodate retinoic acid as ligand. In the rat, ESP I messenger RNA (mRNA) is expressed in …

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Transformation And Transport Of Inorganic Nitrogen In Sediments Of A Southeast Asian Mangrove Forest, Erik Kristensen, Mikael H. Jensen, Gary T. Banta, Kim Hansen, Marianne Holmer, Gary M. King Jan 1998

Transformation And Transport Of Inorganic Nitrogen In Sediments Of A Southeast Asian Mangrove Forest, Erik Kristensen, Mikael H. Jensen, Gary T. Banta, Kim Hansen, Marianne Holmer, Gary M. King

Faculty Publications

The most important inorganic nitrogen transformations (nitrification, denitrification and N fixation) and DIN fluxes in darkened and inundated sediments were studied during the dry season in the Ao Nam Bor mangrove forest at the island of Phuket, Thailand. Dark fluxes of NH4+ were low (not significantly different from zero) and tended to be directed into the sediment in the area vegetated by the tree Rhizophora apiculata (204 μmol m-2 d-1) and out of the sediment in an adjacent unvegetated area (80 μmol m-2 d-1), NO3- appeared to be taken up by the sediment in both areas, although at rates not …

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Identification Of A Class Of Chromatin Boundary Elements, Olivier Cuvier, Craig M. Hart, Ulrich K. Laemmli Jan 1998

Identification Of A Class Of Chromatin Boundary Elements, Olivier Cuvier, Craig M. Hart, Ulrich K. Laemmli

Faculty Publications

Boundary elements are thought to define the ends of functionally independent domains of genetic activity. An assay for boundary activity based on this concept measures the ability to insulate a bracketed, chromosomally integrated reporter gene from position effects. Despite their presumed importance, the few examples identified to date apparently do not share sequence motifs or DNA binding proteins. The Drosophila protein BEAF binds the scs' boundary element of the 87A7 hsp70 locus and roughly half of polytene chromosome interband loci. To see if these sites represent a class of boundary elements that have BEAF in common, we have isolated and …

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Sympatric Sea Shells Along The Sea's Shore: The Geography Of Speciation In The Marine Gastropod Tegula, Michael E. Hellberg Jan 1998

Sympatric Sea Shells Along The Sea's Shore: The Geography Of Speciation In The Marine Gastropod Tegula, Michael E. Hellberg

Faculty Publications

Uncertainty and controversy surround the geographical and ecological circumstances that create genetic differences between populations that eventually lead to reproductive isolation. Two aspects of marine organisms further complicate this situation: (1) many species possess planktonic larvae capable of great dispersal; and (2) obvious barriers to movement between populations are rare. Past studies of speciation in the sea have focussed on identifying the effects of past land barriers and on biogeographical breakpoints. However, assessing the role such undeniable barriers actually play in the initial divergence leading to reproductive isolation requires phylogenetic studies of recent radiations living in varying degrees of sympatry …

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Emergence Of Western Diseases In The Tropical World: The Experience With Chronic Cardiovascular Diseases, Terrence Forrester, Richard S. Cooper, David Weatherall Jan 1998

Emergence Of Western Diseases In The Tropical World: The Experience With Chronic Cardiovascular Diseases, Terrence Forrester, Richard S. Cooper, David Weatherall

Faculty Publications

Our knowledge of the disease burden components of tropical populations is fragmentary. Historically, the infectious diseases have been emphasized but, as some populations have undergone socio-economic changes, vital statistics have described a change in the pattern of disease. The picture is of a decline in infectious and a rise in chronic non-communicable disease. We focus here on the emergence of chronic cardiovascular diseases, and use hypertension as the paradigmic example. Early blood pressure surveys showed a virtual absence of hypertension among rural Africans and moderate prevalences in the Caribbean. Prevalence was highest among US and UK blacks. In a recent …

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