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Carbon, Nitrogen, And Phosphorus Leaching Rates From Spartina Alterniflora Salt Marshes, R. Eugene Turner Jan 1993

Carbon, Nitrogen, And Phosphorus Leaching Rates From Spartina Alterniflora Salt Marshes, R. Eugene Turner

Faculty Publications

Annual carbon, nitrogen, and phosphorus leachate rates from live Spartina alterniflora Loisel in a Louisiana (USA) salt marsh were estimated to be 200, 14, and 3 g m-2, respectively, and to peak in summer and higher salinit~es. Leachate losses of P, N and C are equivalent to a turnover of live plant tissues of 10, 17 and 49 d, respectively, when submerged, and 148, 250 and 721 d, respectively, when unsubmerged. Plant leachate losses during marsh submergence and non-submergence are nearly equal because release rates are 15x greater during submergence. Nitrogen and carbon concentrations relative to phosphorus are proportionately 4x …

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Carbon, Nitrogen, And Phosphorus Leaching Rates From Spartina-Alterniflora Salt Marshes, R E. Turner Jan 1993

Carbon, Nitrogen, And Phosphorus Leaching Rates From Spartina-Alterniflora Salt Marshes, R E. Turner

Faculty Publications

Annual carbon, nitrogen, and phosphorus leachate rates from live Spartina alterniflora Loisel in a Louisiana (USA) salt marsh were estimated to be 200, 14, and 3 g M-2, respectively, and to peak in summer and higher salinities. Leachate losses of P, N and C are equivalent to a turnover of live plant tissues of 10, 17 and 49 d, respectively, when submerged, and 148, 250 and 721 d, respectively, when unsubmerged. Plant leachate losses during marsh submergence and non-submergence are nearly equal because release rates are 15 x greater during submergence. Nitrogen and carbon concentrations relative to phosphorus are proportionately …

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Predicting Performance On The National Dietetic Registration Exam., Rachel Martin Fournet Jan 1993

Predicting Performance On The National Dietetic Registration Exam., Rachel Martin Fournet

LSU Historical Dissertations and Theses

The purpose of this study was to determine if relationships exist between student demographic or personal data, academic achievement and student perceptions of factors relative to predicting performance on the Registration Dietetic (R.D.) Exam. Perceptions of factors relative to predicting performance on the R.D. exam was also determined from undergraduate dietetic program directors, to explore the extent of agreement between students and educators. This information was used to develop a predictive model explaining a significant proportion of the variance in R.D. exam scores. A researcher designed questionnaire was administered to a nationwide random sample of first time eligible candidates for …

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Lsu General Catalog 1993-1994, Louisiana State University And Agricultural And Mechanical College Jan 1993

Lsu General Catalog 1993-1994, Louisiana State University And Agricultural And Mechanical College

LSU General Catalog

The LSU General Catalog describes all undergraduate and graduate departments and programs with degree requirements and courses offered for each one. The General Catalog includes information on registration and financial aid as well as academic services offered to all students.

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The Dynamics Of Collective Farming: A Case Study Of Fish Farm Cooperatives In The Prefectures Of Butare And Gikongoro, Rwanda., Alphonse Rubagumya Jan 1993

The Dynamics Of Collective Farming: A Case Study Of Fish Farm Cooperatives In The Prefectures Of Butare And Gikongoro, Rwanda., Alphonse Rubagumya

LSU Historical Dissertations and Theses

Cooperative fish farming not only insures a wider distribution of land and fish farming technology resources to larger segments of the population, but also makes possible the integration of limited individual resources into sizable and economically more viable production and marketing units. On the basis that more efficient internal organization can lead to greater cooperative performance, the purpose of this study is to identify organizational attributes and practices associated with effectiveness of fish farming cooperatives in Rwanda. Data for the study were obtained from a sample of 200 fish farm groups selected in the prefectures of Butare and Gikongoro, Rwanda. …

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The Low Co2-Inducible 36-Kilodalton Protein Is Localized To The Chloroplast Envelope Of Chlamydomonas Reinhardtii, Ziyadin Ramazanov, Catherine B. Mason, Anne M. Geraghty, Martin H. Spalding, James V. Moroney Jan 1993

The Low Co2-Inducible 36-Kilodalton Protein Is Localized To The Chloroplast Envelope Of Chlamydomonas Reinhardtii, Ziyadin Ramazanov, Catherine B. Mason, Anne M. Geraghty, Martin H. Spalding, James V. Moroney

Faculty Publications

The localization of the 36-kD polypeptide of Chlamydomonas reinhardtii induced by photoautotrophic growth on low CO2 concentrations (0.03% in air [v/v], low CO2-grown cells) has been investigated. This polypeptide was specifically localized to the chloroplast envelope membranes isolated from low CO2-grown cells and was not present in the chloroplast envelopes isolated from high (5% CO2 in air [v/v]) CO2-grown cells. The 36-kD protein does not show carbonic anhydrase activity and was not present on the plasma membranes isolated from low CO2-grown cells. This protein may, in part, account for the different inorganic carbon uptake characteristics observed in chloroplasts isolated from …

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Glycine And Alanine Supplementation Of Culture Medium Enhances Development Of In Vitro Matured And Fertilized Cattle Embryos, K. Moore, K. R. Bondioli Jan 1993

Glycine And Alanine Supplementation Of Culture Medium Enhances Development Of In Vitro Matured And Fertilized Cattle Embryos, K. Moore, K. R. Bondioli

Faculty Publications

One-cell cattle embryos were prepared by in vitro oocyte maturation and fertilization (IVM/IVF) and cultured with or without oviductal cells. Embryos were evaluated after 7 days in culture to determine the percentage developing from the 1-cell stage to the morula or blastocyst stage. The combination of glycine (2 mM) and alanine (1 mM) with oviductal cells (experiment 1) improved embryo development over that in control culture (29 vs. 13%; p < 0.05). An optimum response was obtained with 10 mM glycine and 1 mM alanine in coculture (experiments 2 and 3). In experiment 4, the effects of glycine (0 or 10 mM), alanine (0 or 1 mM), and the presence or absence of oviductal cells were tested. In the absence of oviductal cells, the addition of glycine, alanine, or glycine and alanine combined improved embryonic development over that in control medium (45, 33, 42 vs. 24%, p < 0.001, p < 0.05, p < 0.001, respectively). However, the effect of the combination of glycine and alanine was not different from that of glycine alone when oviductal cells were absent (42 vs. 45%, p > 0.10). In the presence of oviductal cells, glycine or the combination of glycine and alanine improved embryonic development over that in the control medium with cells (47, 55 vs. 37%, …

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Response Of Early Lactation Cows To Fat Supplementation In Diets With Different Nonstructural Carbohydrate Concentrations, James C. Coomer, Henry E. Amos, Cathy C. Williams, Jeffrey G. Wheeler Jan 1993

Response Of Early Lactation Cows To Fat Supplementation In Diets With Different Nonstructural Carbohydrate Concentrations, James C. Coomer, Henry E. Amos, Cathy C. Williams, Jeffrey G. Wheeler

Faculty Publications

Twenty-four high producing (36.7 kg/d, initially) Holstein cows in early lactation were used in a 63-d lactation trial to study the effects of low (28%), medium (31%). and high (37%) nonstructural carbohydrate concentrations in diets with added fat. Diets with isonitrogenous (17% CP) and fed as TMR with 41% sorghum silage. Nonstructural carbohydrate concentrations were altered by substitution of corn gluten feed and soybean hulls (50:50) for wheat and corn in the concentrate portion of the diet. Fat was added at 3% of DM in the form of yellow grease. Production of milk (38.5, 38.9, and 40.4 kg/d) and 3.5% …

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Response Of Early Lactation Cows To Fat Supplementation In Diets With Different Nonstructural Carbohydrate Concentrations, James C. Coomer, Henry E. Amos, Cathy C. Williams, Jeffrey G. Wheeler Jan 1993

Response Of Early Lactation Cows To Fat Supplementation In Diets With Different Nonstructural Carbohydrate Concentrations, James C. Coomer, Henry E. Amos, Cathy C. Williams, Jeffrey G. Wheeler

Faculty Publications

Twenty-four high producing (36.7 kg/d, initially) Holstein cows in early lactation were used in a 63-d lactation trial to study the effects of low (28%), medium (31%). and high (37%) nonstructural carbohydrate concentrations in diets with added fat. Diets with isonitrogenous (17% CP) and fed as TMR with 41% sorghum silage. Nonstructural carbohydrate concentrations were altered by substitution of corn gluten feed and soybean hulls (50:50) for wheat and corn in the concentrate portion of the diet. Fat was added at 3% of DM in the form of yellow grease. Production of milk (38.5, 38.9, and 40.4 kg/d) and 3.5% …

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Localization And Nucleotide Sequences Of Genes Mediating Site-Specific Recombination Of The Slp1 Element In Streptomyces Lividans, M. A. Brasch, G. S. Pettis, S. C. Lee, S. N. Cohen Jan 1993

Localization And Nucleotide Sequences Of Genes Mediating Site-Specific Recombination Of The Slp1 Element In Streptomyces Lividans, M. A. Brasch, G. S. Pettis, S. C. Lee, S. N. Cohen

Faculty Publications

SLP1 is a 17.2-kbp genetic element indigenous to the Streptomyces coelicolor chromosome. During conjugation, SLP1 can undergo excision and subsequent site-specific integration into the chromosomes of recipient cells. We report here the localization, nucleotide sequences, and initial characterization of the genes mediating these recombination events. A region of SLP1 adjacent to the previously identified site of integration, attP, was found to be sufficient to promote site-specific integration of an unrelated Streptomyces plasmid. Nucleotide sequence analysis of a 2.2-kb segment of this region reveals two open reading frames that are adjacent to and transcribed toward the attP site. One of these, …

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Race, Income, And Survival From Breast Cancer At Two Public Hospitals, David Ansell, Steven Whitman, Rebecca Lipton, Richard Cooper Jan 1993

Race, Income, And Survival From Breast Cancer At Two Public Hospitals, David Ansell, Steven Whitman, Rebecca Lipton, Richard Cooper

Faculty Publications

Background. Some studies have shown that adjustment for socioeconomic status reduces breast cancer survival differences between blacks and whites. The purpose of this study is to evaluate the effect of age, race, stage, treatment, and income status on breast cancer survival among women attending public hospitals in Chicago, Illinois. Methods. Hospital Cancer Registry data on 887 black women and 265 white women with breast cancer onset between 1973–1985 were analyzed using Cox regression and Kaplan–Meier techniques. The purpose was to examine the effect of age, race, stage, treatment, and income on breast cancer survival. Results. Black women with breast cancer …

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Methodological Content And Teaching Delivery Used By Vocational Teacher Education Faculty In University Council And Other Selected Higher Education Institutions., Robert Barry Blair Jan 1993

Methodological Content And Teaching Delivery Used By Vocational Teacher Education Faculty In University Council And Other Selected Higher Education Institutions., Robert Barry Blair

LSU Historical Dissertations and Theses

The purpose of this study was to identify the methodological content and teaching delivery used by vocational teacher education faculty in University Council for Vocational Education (UCVE) institutions and other selected higher education institutions (NON-UCVE). The population for this study was defined as: full-time vocational teacher education faculty in programs at Research I, Research II, and Doctorate Granting Colleges and Universities I where comprehensive vocational education programs were offered. Administrative leaders for each institution identified the vocational teacher education faculty which established the frame for the study. A stratified-random cluster sample of vocational teacher educators from UCVE institutions and NON-UCVE …

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Nitrogen Composition And Feeding Value Of Annual Forages As Affected By Nitrogen Fertilization And Defoliation Frequency., Youbo Zhang Jan 1993

Nitrogen Composition And Feeding Value Of Annual Forages As Affected By Nitrogen Fertilization And Defoliation Frequency., Youbo Zhang

LSU Historical Dissertations and Theses

Initially, various solvents were tested for their efficacy in isolating soluble nitrogen (SN) from annual ryegrass and berseem clover. Plant nitrogen (PN) solubilities were similar in.5 M NaCl, autoclaved rumen fluid, borate phosphate buffer and Burroughs' solution. The mean PN solubilities across forages ranged from 12% for.1 M acetic acid to 45% for.2% NaOH. At 4$\sp\circ$C, 15% TCA precipitated the most soluble plant protein nitrogen (SPPN). Nitrogen (N) yield, concentrations of PN, SN, SPPN and soluble nonprotein nitrogen (SNPN) increased linearly as N fertilization (NF) increased from 0 to 335 kg N/ha. Decreasing defoliation interval (DI) from 6- to 2-wk …

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Dual Diagnosis In Persons With Severe Or Profound Mental Retardation: A Reliability Study Of The Dash., Jay Anthony Sevin Jan 1993

Dual Diagnosis In Persons With Severe Or Profound Mental Retardation: A Reliability Study Of The Dash., Jay Anthony Sevin

LSU Historical Dissertations and Theses

The present study was designed to extend the literature on assessing psychopathology in persons with mental retardation. The primary goal of the study was to evaluate the psychometric properties of the Diagnostic Assessment for the Severely Handicapped (DASH), focusing on reliability issues. A secondary goal was to examine the prevalence of psychopathology and behavior problems in the severely handicapped. Subjects included 658 institutionalized adults with severe or profound mental retardation. Adequate reliability of DASH items and subscales, with a few notable exceptions, was obtained. Prevalence rates of various behavior disorders and symptoms of mental illness are presented. Practical implications of …

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Structural Analysis And Methionine Ehancement Of The Bean Seed Storage Protein Phaseolin., John M. Dyer Jan 1993

Structural Analysis And Methionine Ehancement Of The Bean Seed Storage Protein Phaseolin., John M. Dyer

LSU Historical Dissertations and Theses

Common beans are widely utilized as a food source, yet are limited as a complete source of protein due to low levels of methionine, an essential amino acid for humans. A protein engineering strategy was developed to increase the methionine content of phaseolin, the primary seed storage protein in common beans. The engineering strategy consists of three major parts. In the first part, a set of biophysical probes was developed to characterize the stability of wild-type and modified phaseolin proteins. I used absorbance, fluorescence emission, circular dichroism, and fluorescence polarization anisotropy to monitor phaseolin denaturation induced by urea, guanidinium chloride, …

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Deterrents To Participation In Parenting Education., Debora Coats Johnson Jan 1993

Deterrents To Participation In Parenting Education., Debora Coats Johnson

LSU Historical Dissertations and Theses

The purpose of this study was to determine the deterrents to participation by adults in parenting education programs. The objectives were to: (1) describe parents with children in selected day care facilities by sociodemographic variables; (2) determine factors which deterred those parents from participating in parenting education; and (3) determine if a correlation existed between the sociodemographic variables and factors which deterred their participation. The target population was parents with children enrolled in License Type A day care facilities. The accessible population was parents with children enrolled in selected License Type A day care facilities in Tangipahoa Parish, Louisiana. A …

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Psychosocial Co-Factors And Hiv Disease Status., Bradley Thomas Thomason Jan 1993

Psychosocial Co-Factors And Hiv Disease Status., Bradley Thomas Thomason

LSU Historical Dissertations and Theses

Concern over the devastating effects of the Human Immunodeficiency Virus (HIV) has been met with rigorous research efforts by allied health professions. Identifying variables, or co-factors, that contribute to the progression of HIV has been of increased interest to health professionals in recent years. Social scientists as well as medical professionals have begun to offer evidence that certain psychosocial co-factors are important in predicting the health status of HIV-positive individuals. A few models have been offered to illustrate the interrelations among psychosocial co-factors and HIV disease. Stress, social support, coping, and mood states constitute the most frequently researched variables in …

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Worksite Health Promotion In America: The Impact Of Organizational Context On Corporate Wellness Programming., Neller Ree Simpkins Jan 1993

Worksite Health Promotion In America: The Impact Of Organizational Context On Corporate Wellness Programming., Neller Ree Simpkins

LSU Historical Dissertations and Theses

The purpose of this study is to examine the factors associated with corporate wellness programming in contemporary U.S. business organizations. First, I construct an ideal-type of wellness program components in order to profile varying arrays (i.e., number and types) of health and fitness activities across corporations. Then, I detail the extent of health promotion programming in business organizations and in major corporations, using the National Survey of Worksite Health Promotion Activities and the Worksite Health Promotion Program Survey of Fortune 500 companies. The central research task of this study is to explore the factors that account for the diversity observed …

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Peasant Subsistence In Northwestern Haiti: Geography, Cultural Ecology, And Rural Development., Edward Cameron Britton Jan 1993

Peasant Subsistence In Northwestern Haiti: Geography, Cultural Ecology, And Rural Development., Edward Cameron Britton

LSU Historical Dissertations and Theses

Geographers are challenged to explain "the why of where." This study grapples with "whys" of peasant subsistence in contemporary rural Haiti. Cultural ecology, one of the fundamental themes in cultural geography, examines the interplay between cultural traditions and the realities of subsistence in a given physical environment. Haitian cultural traditions derive from a rich melange of folkways from West Africa, Indian Middle America, and Western Europe. The land is semiarid and hilly in Northwestern Haiti, the poorest, driest, and most sparsely settled of Haiti's provinces. Crops and livestock betray traditional preferences in foodways, and reveal much about the constraints of …

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Photosynthetic Response To Elevated Carbon Dioxide Concentrations In The Aerenchyma Of Typha Latifolia L. Leaves., John Van Horne Constable Jan 1993

Photosynthetic Response To Elevated Carbon Dioxide Concentrations In The Aerenchyma Of Typha Latifolia L. Leaves., John Van Horne Constable

LSU Historical Dissertations and Theses

This study examined the importance of the leaf aerenchyma gas space as a CO$\sb2$ source for photosynthesis in Typha latifolia L. (broadleaf cattail). In the field there was a distinct diurnal pattern of CO$\sb2$ concentration ( (CO$\sb2$)) in the aerenchyma gas space. At dawn the aerenchyma (CO$\sb2$) was 4 to 18 times above atmospheric levels. By midday the aerenchyma (CO$\sb2$) declined to near atmospheric levels and increased again in the late afternoon. It is hypothesized that this diurnal pattern may be controlled by photosynthetic demand for CO$\sb2$. Aerenchyma gas space was estimated as $>$50% of leaf volume, and the …

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Factors Contributing To Resistance In Rice To The Rice Water Weevil, Lissorhoptrus Oryzophilus Kuschel., Francois Kouame N'Guessan Jan 1993

Factors Contributing To Resistance In Rice To The Rice Water Weevil, Lissorhoptrus Oryzophilus Kuschel., Francois Kouame N'Guessan

LSU Historical Dissertations and Theses

Studies were conducted in the field and greenhouse to identify sources of rice water weevil (Lissorhoptrus oryzophilus Kuschel) resistance in rice, Oryza sativa L., and determine the mechanisms of resistance. Rice lines of various sources, including breeding lines, somaclone lines and world collection lines, were evaluated. Tolerance was investigated using replicated insecticide treated and untreated plots in a split-plot design, and antibiosis and/or antixenosis were assessed using caged insect-infested plants in randomized block designs. Resistance predictors included rice water weevil larval populations, larval root pruning damage, plant height and grain yield. Anther culture lines 95-2836 and 95-3527, Louisiana breeding lines …

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Antimicrobial Properties Of Glycerol Monolaurate Either Alone Or Combined With Selected Organic Acids Against Listeria Monocytogenes., Deog-Hwan Oh Jan 1993

Antimicrobial Properties Of Glycerol Monolaurate Either Alone Or Combined With Selected Organic Acids Against Listeria Monocytogenes., Deog-Hwan Oh

LSU Historical Dissertations and Theses

The objective of this study was to evaluate the antimicrobial properties of glycerol monolaurate (monolaurin) either alone or in combination with organic acids against Listeria monocytogenes in model broth or food. The minimal inhibitory concentration (MIC) of monolaurin was reduced by decreasing the pH value of the medium. The contribution of temperature to monolaurin effectiveness showed that lethal effects of monolaurin increased at higher temperatures and lower pH values, whereas, bacteriostatic effects on growth increased as temperature and pH decreased. The inhibitory effect of ethanol on the growth of L. monocytogenes was slight up to 2.5% ethanol, but was significant …

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First Ray Joint Mobility, Pressure And Ulceration Of The First Metatarsal Head In Diabetic Patients., James Allen Birke Jan 1993

First Ray Joint Mobility, Pressure And Ulceration Of The First Metatarsal Head In Diabetic Patients., James Allen Birke

LSU Historical Dissertations and Theses

This dissertation reviews the pathomechanics of plantar ulceration in patients with diabetes mellitus, and studies the relationship between joint mobility, pressure and the location of ulceration at the first metatarsal head. Neuropathy, mechanical stress and vascular disease have been shown to be the primary causes of ulceration in patients with diabetes. Sensory neuropathy is considered the permissive cause of plantar ulceration. Plantar ulcerations do not occur without loss of sensation in the foot. Other factors including motor neuropathy, autonomic neuropathy, abnormal mechanical stress, foot deformity, joint limitation, and hyperkeratosis are considered important component causes in plantar ulceration. Autonomic neuropathy and …

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Acetylation Of Seaweed Alginate By Pseudomonas Syringae., Jin Woo Lee Jan 1993

Acetylation Of Seaweed Alginate By Pseudomonas Syringae., Jin Woo Lee

LSU Historical Dissertations and Theses

Acetylation of bacterial alginate by Pseudomonas syringae subsp. phaseolicola ATCC 19304 was independent of alginate biosynthesis. This allowed the development of a process for acetylating seaweed alginate using immobilized P. syringae ATCC 19304 cells. About 50% of the mannuronic acid residues of seaweed alginate were acetylated by carbon immobilized P. syringae cells in a fluidized bed, up-flow reactor system fed continuously with seaweed alginate and gluconic acid. O-Acetylation by this process was found to be specific for the C-2 and/or C-3 position(s) of mannuronate residues. Acetylated seaweed alginate showed altered properties including increased viscosity and changed affinities for some cations.

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Determinants Of Mangrove Species Distribution In Neotropical Forests: Biotic And Abiotic Factors Affecting Seedling Survival And Growth., Karen Lee Mckee Jan 1993

Determinants Of Mangrove Species Distribution In Neotropical Forests: Biotic And Abiotic Factors Affecting Seedling Survival And Growth., Karen Lee Mckee

LSU Historical Dissertations and Theses

Mangroves are salt-tolerant trees and shrubs that dominate the intertidal zone in many tropical and subtropical coastal regions. These intertidal forests often exhibit relatively distinct and recurring patterns of species distribution. A series of field and laboratory experiments examined biotic and abiotic factors affecting survival and growth of three neotropical mangrove species: Rhizophora mangle (red mangrove), Avicennia germinans (black mangrove), and Laguncularia racemosa (white mangrove). A field survey across a mangrove island range in Belize revealed six vegetation zones based on differences in dominant canopy species, size and vigor of the trees, spatial position relative to the shoreline, and hydro-edaphic …

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Field Evaluation Of The Movement Of Agricultural Chemical Contaminants In Alluvial Soils With A Shallow Water Table., Orlino Agustin Mercado Jan 1993

Field Evaluation Of The Movement Of Agricultural Chemical Contaminants In Alluvial Soils With A Shallow Water Table., Orlino Agustin Mercado

LSU Historical Dissertations and Theses

The movement of agricultural chemical contaminants in alluvial soils with a shallow water table in a warm, humid environment was evaluated in this study. Bromide, a non-adsorbent tracer, was used to assess the pathways of water and solute in the soil profile. The movement and fate of three commonly used herbicides: Trifluralin, Metolachlor, and Metribuzin were determined. The data gathered from the herbicide study were used to compare with the results of simulation to validate the pesticide component of the GLEAMS model. The study was conducted at the Ben Hur Research Farm of the Louisiana Agricultural Experiment Station. Five relatively …

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A Cross-Age Study Of Students' Knowledge Of Insect Metamorphosis: Insights Into Their Understanding Of Evolution., Mary Susan Nichols Jan 1993

A Cross-Age Study Of Students' Knowledge Of Insect Metamorphosis: Insights Into Their Understanding Of Evolution., Mary Susan Nichols

LSU Historical Dissertations and Theses

Insect metamorphosis is relatively easy to explain at a superficial level, but a deep understanding of the concept reveals a complex array of interrelationships, most importantly those that address evolution. This is significant because, in biology, evolution is considered to be a central theme. Participants for this study were selected from grades 5, 7, 9, and 11 according to low, middle, or high achievement levels in their science classes, and to scores on a national achievement test. The research incorporated a three-level response strategy in order to ascertain more completely students' knowledge of insect metamorphosis, and to better suggest how …

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Characterization Of Physiological Responses Of Suspension Cells From Alligator Weed (Alternanthera Philoxeroides (Mart.); Griseb) To An Abrupt Increase In Salinity., Gloria Balagtas-Burow Jan 1993

Characterization Of Physiological Responses Of Suspension Cells From Alligator Weed (Alternanthera Philoxeroides (Mart.); Griseb) To An Abrupt Increase In Salinity., Gloria Balagtas-Burow

LSU Historical Dissertations and Theses

Dark-grown suspension cells of alligator weed (Alternanthera philoxeroides (Mart.) Griseb) were established in Murashige and Skoog medium and used to characterize several cellular responses to an abrupt increase in salinity (0 to 200 mol m$\sp{-3}$ NaCl). The fresh weight and cell density of salt-treated cells of alligator weed more than doubled by 7 d. Cell viability declined to 77% by 1 d, but recovered to 86% by 7 d after salt treatment. These responses indicate that alligator weed cells survived and adapted to an abrupt increase in salinity. Osmotic potential ($\psi\sb\pi$) of salt-treated cells declined to the $\psi\sb\pi$ of the …

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Nitrogen Form, Aluminum, And Their Interaction Effects On Growth, Nitrogen Absorption And Chemical Composition Of Annual Ryegrass (Lolium Multiflorum Lam.)., Jose Ramon Binns Jan 1993

Nitrogen Form, Aluminum, And Their Interaction Effects On Growth, Nitrogen Absorption And Chemical Composition Of Annual Ryegrass (Lolium Multiflorum Lam.)., Jose Ramon Binns

LSU Historical Dissertations and Theses

Annual ryegrass (Lolium multiflorum Lam.) is frequently grown on acid soils with potentially toxic levels of aluminum (Al). Interaction effects of nitrogen (N) form and Al on growth and nutrient relationships in ryegrass require further definition for environmental, biological, and economic reasons. Nutrient solution and soil experiments were conducted in growth chambers to determine interactive effects of ammonium: nitrate (NH$\sb4$:NO$\sb3$) ratios and Al on growth, N absorption, nutrient composition, cation influx rate, and N use efficiency. In nutrient solution studies, highest dry weights of shoots were obtained when the two N forms were present in equal proportions, while highest dry …

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Professional Competencies Needed By Extension Agents In The Louisiana Cooperative Extension Service., William Blaine Reynolds Jan 1993

Professional Competencies Needed By Extension Agents In The Louisiana Cooperative Extension Service., William Blaine Reynolds

LSU Historical Dissertations and Theses

The purpose of this study was to identify the professional competencies needed by the Cooperative Extension agents in Louisiana as perceived by extension agents. Additional purposes of the study were to identify when the respondents believed the identified competencies should be acquired and to describe the responding agents with regard to selected demographic variables. One-hundred forty-one professional competency items were included in a questionnaire that was divided into two parts. The competencies were divided into nine categories that were designed to measure participants' perceptions as to the importance of need for the competencies by extension agents. A five-point Likert-type scale …

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