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Chloropigment Distribution And Transport On The Inner Shelf Off Duck, North Carolina, E.J. D'Sa, S.E. Lohrenz, J.H. Churchill, V.L. Asper, J.L. Largier, A.J. Williams Iii Jan 2001

Chloropigment Distribution And Transport On The Inner Shelf Off Duck, North Carolina, E.J. D'Sa, S.E. Lohrenz, J.H. Churchill, V.L. Asper, J.L. Largier, A.J. Williams Iii

Faculty Publications

No abstract provided.

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Learning To Teach In A Virtual Environment: A Case Study Of The Louisiana Virtual Classroom Teachers., Rachel Geralyn Sellers Jan 2001

Learning To Teach In A Virtual Environment: A Case Study Of The Louisiana Virtual Classroom Teachers., Rachel Geralyn Sellers

LSU Historical Dissertations and Theses

In the 2000 school year the Louisiana Department of Education commissioned a Distance Learning Task Force Committee to establish State Standards for Distance Education. These Standards supported the core beliefs set forth by the state's educational technology goal: "All educators and learners will have access to technologies that are effective in improving student achievement" (State Standards, p. 1). Emerging technologies, such as web-based instruction, were implemented to support these standards. These new technologies prompted the Louisiana Center for Educational Technology to establish the Louisiana Virtual Classroom. This project was a program that included a consortium of high school teachers for …

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Pathobiology Of Streptococcus Iniae Infections In Cultured Tilapia., Alvin Cyril Camus Jan 2001

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 …

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Debussy And The Fragment., Linda Page Cummins Jan 2001

Debussy And The Fragment., Linda Page Cummins

LSU Historical Dissertations and Theses

The dissertation identifies and studies fragmentary structures---structures that give the impression of incompletion or interruption---in the music of Claude Debussy. Although fragments---which play a decisive role in nineteenth- and twentieth-century aethetics---have been discussed extensively in literature and the visual arts, relatively little critical attention was paid to them by musicologists until Daverio and Rosen, in the 1990s, investigated the romantic musical fragment. The dissertation traces the history of the literary fragment from the late middle ages through the nineteenth century. With this history as background, it places Debussy's fragmentary musical structures in relation to those of composers like Schumann and …

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Neuropsychological Effects Of Acute Mustard Gas Exposure., James Bryon Pinkston Jan 2001

Neuropsychological Effects Of Acute Mustard Gas Exposure., James Bryon Pinkston

LSU Historical Dissertations and Theses

Introduction. Approximately 600 industrial workers reported exposure to sub-lethal levels of sulfur mustard gas and nitrogen mustard gas. A sample of 203 of these workers were administered standardized measures of perceptual, motor, intellectual, academic, attentional, memory, abstract reasoning, and psychological functioning, as well as level of effort during testing. Mean time from exposure to testing was 1.18(SD = .35) years. Males comprised 97.5% of the participants and 79.3% were Caucasian. Mean education was 11.67(SD = 1.73) years and mean age at exposure was 36.74( SD = 10.31) years. Method. Mustard gas exposure severity was defined by the presence of obvious …

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Show Me The Money: An Analysis Of The Impact Of Voter Recognition On The Campaign Spending Effects Of House And Senate Candidates., Nicholas Chad Long Jan 2001

Show Me The Money: An Analysis Of The Impact Of Voter Recognition On The Campaign Spending Effects Of House And Senate Candidates., Nicholas Chad Long

LSU Historical Dissertations and Theses

The focus of this dissertation is campaign spending in congressional elections. I examine the benefits that candidates receive from campaign expenditures. I think that challengers receive greater benefits from spending than incumbents, but that the extent of these benefits depends on the type of challenger. High-quality challengers are those that have previous experience in an important elective office, while low-quality challengers lack this experience. Because of this experience, high-quality challengers enjoy a higher level of recognition among the electorate than low-quality challengers. I think that the benefits that challengers receive from expenditures are inversely related to the level of recognition …

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A World Of Deference: Paradoxes Of Victorian Paternalism In John Ruskin, Charles Dickens, And John Stuart Mill., Peter Mitchell O'Neill Jan 2001

A World Of Deference: Paradoxes Of Victorian Paternalism In John Ruskin, Charles Dickens, And John Stuart Mill., Peter Mitchell O'Neill

LSU Historical Dissertations and Theses

This study examines the residual paternalist ideology in three canonical Victorian texts: namely, John Ruskin's The Nature of Gothic, Charles Dickens's Hard Times, and John Stuart Mill's Autobiography. In exposing an epistemological tension between paternalist and liberal beliefs---especially a putative concern for the working class---that exists in these texts, this discussion concludes that not only are the cultural forces of benevolent authority insidious in Victorian culture, but that the paradoxes that emerge in these texts may reflect a public ambiguity toward the prevalent structures sustaining Victorian paternalism. The three texts examined inscribe hierarchical principles---while ironically exposing them---in generally similar ways: …

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Colonialism And Landscape In The Americas: Material/Conceptual Transformations And Continuing Consequences, Andrew Sluyter Jan 2001

Colonialism And Landscape In The Americas: Material/Conceptual Transformations And Continuing Consequences, Andrew Sluyter

Faculty Publications

No abstract provided.

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Ganadería Española Y Cambio Ambiental En Las Tierras Bajas Tropicales De Veracruz, México, Siglo Xvi, Andrew Sluyter Jan 2001

Ganadería Española Y Cambio Ambiental En Las Tierras Bajas Tropicales De Veracruz, México, Siglo Xvi, Andrew Sluyter

Faculty Publications

No abstract provided.

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Comparison Of Genomic And Predicted Amino Acid Sequences Of Respiratory And Enteric Bovine Coronaviruses Isolated From The Same Animal With Fatal Shipping Pneumonia, V. N. Chouljenko, X. Q. Lin, J. Storz, K. G. Kousoulas, A. E. Gorbalenya Jan 2001

Comparison Of Genomic And Predicted Amino Acid Sequences Of Respiratory And Enteric Bovine Coronaviruses Isolated From The Same Animal With Fatal Shipping Pneumonia, V. N. Chouljenko, X. Q. Lin, J. Storz, K. G. Kousoulas, A. E. Gorbalenya

Faculty Publications

The complete genome sequences are reported here of two field isolates of bovine coronavirus (BCoV), which were isolated from respiratory and intestinal samples of the same animal experiencing fatal pneumonia during a bovine shipping fever epizootic. Both genomes contained 31028 nucleotides and included 13 open reading frames (ORFs) flanked by 5′- and 3′-untranslated regions (UTRs). ORF1a and ORF1b encode replicative polyproteins pp1a and pp1ab, respectively, that contain all of the putative functional domains documented previously for the closest relative, mouse hepatitis virus. The genomes of the BCoV isolates differed in 107 positions, scattered throughout the genome except the 5′-UTR. Differences …

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Elucidation Of The Genomic Nucleotide Sequence Of Bovine Coronavirus And Analysis Of Cryptic Leader Mrna Fusion Sites, Vladimir N. Chouljenko, Timothy P. Foster, Xiaoqing Lin, Johannes Storz, Konstantin G. Kousoulas Jan 2001

Elucidation Of The Genomic Nucleotide Sequence Of Bovine Coronavirus And Analysis Of Cryptic Leader Mrna Fusion Sites, Vladimir N. Chouljenko, Timothy P. Foster, Xiaoqing Lin, Johannes Storz, Konstantin G. Kousoulas

Faculty Publications

No abstract provided.

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A Phylogenetic Analysis Of Variation In Reproductive Mode Within An Australian Lizard (Saiphos Equalis, Scincidae), Sarah A. Smith, Christopher C. Austin, Richard Shine Jan 2001

A Phylogenetic Analysis Of Variation In Reproductive Mode Within An Australian Lizard (Saiphos Equalis, Scincidae), Sarah A. Smith, Christopher C. Austin, Richard Shine

Faculty Publications

Saiphos equalis, a semi-fossorial scincid lizard from south-eastern Australia, is one of only three reptile species world-wide that are known to display geographic variation in reproductive mode. Uniquely, Saiphos equalis includes populations with three reproductive modes: oviparous with long (15-day) incubation periods; oviparous with short (5-day) incubation periods; and viviparous (0-day incubation periods). No Saipho populations show 'normal' scincid oviparity (>30-day incubation period). We used mitochondrial nucleotide sequences (ND2 and cytochrome b) to reconstruct relationships among populations from throughout the species' distribution in New South Wales, Australia. Under the phylogenetic species concept, phylogenetic analyses are consistent with the oviparous …

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Rickettsia Felis: Molecular Characterization Of A New Member Of The Spotted Fever Group, D. H. Bouyer, J. Stenos, P. Crocquet-Valdes, C. G. Moron, V. L. Popov, J. E. Zavala-Velazquez, L. D. Foil, D. R. Stothard, A. F. Azad, D. H. Walker Jan 2001

Rickettsia Felis: Molecular Characterization Of A New Member Of The Spotted Fever Group, D. H. Bouyer, J. Stenos, P. Crocquet-Valdes, C. G. Moron, V. L. Popov, J. E. Zavala-Velazquez, L. D. Foil, D. R. Stothard, A. F. Azad, D. H. Walker

Faculty Publications

In this report, placement of Rickettsia felis in the spotted fever group (SFG) rather than the typhus group (TG) of Rickettsia is proposed. The organism, which was first observed in cat fleas (Ctenocephalides felis) by electron microscopy, has not yet been reported to have been cultivated reproducibly, thereby limiting the standard rickettsial typing by serological means. To overcome this challenge, several genes were selected as targets to be utilized for the classification of R. felis. DNA from cat fleas naturally infected with R. felis was amplified by PCR utilizing primer sets specific for the 190 kDa surface antigen (rOmpA) and …

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Isolation And Characterization Of A Rhodobacter Capsulatus Hemc Mutant., Karen Coleman Sullivan Jan 2001

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 …

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Cultural Preservation In The Romansh Landscape: A Geography Of The Swiss -Romansh Movement., Erik George Prout Jan 2001

Cultural Preservation In The Romansh Landscape: A Geography Of The Swiss -Romansh Movement., Erik George Prout

LSU Historical Dissertations and Theses

The research explores the cultural landscape of Romansh speakers in Switzerland. The fundamental question is whether small ethno-linguistic groups can create and protect a place (earthly and poetic) for their language to flourish. Swiss-Romansh have many advantages because of their political stability and economic prosperity. Their efforts in promoting and protecting the Romansh language offer a possible model for other culture groups. The research elucidates four distinct geographic scales: national (Switzerland's multilingual federalism), regional (alpine canton of Grischun/Graubunden), local Romansh villages (vinscnanca or communes), and an imaginary Rhactian ethnicity. I employ the term cultural preservation to discuss the Romansh situation. …

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The Role Of Immunity In Resistance Of Gulf Coast Native Sheep To Haemonchus Contortus Infection., Maria Teresa Pena Jan 2001

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 …

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Mapping Enredos Of Complex Spaces. A Regional Geography Of Olancho, Honduras., Mark Andrew Bonta Jan 2001

Mapping Enredos Of Complex Spaces. A Regional Geography Of Olancho, Honduras., Mark Andrew Bonta

LSU Historical Dissertations and Theses

This dissertation is a regional geography of the department of Olancho in northeastern Honduras. It focuses on the enredos (entangled situations) that characterize geographic reality, particularly in the interlocked domains of nation-state priorities, local identities, rain forest conservation, and sustainable development. The overarching theoretical framework of this dissertation is the collaborative work of complexity theorists Gilles Deleuze and Felix Guattari. The major theme running through "Mapping Enredos" is the multidimensional nature of spatiality (complex spaces), ground for human and non-human existence as well as source of endless conflicts. Fieldwork was undertaken from 1999 to 2000. Qualitative research methods employed include …

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Factors Affecting Community Structure Of Mangroves Associated With Point Bars And Islands In A Costa Rican Estuary., Patricia Delgado-Sanchez Jan 2001

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 …

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A Performer's Guide To Theatrical Elements In Selected Trombone Literature., Cason Austin Duke Jan 2001

A Performer's Guide To Theatrical Elements In Selected Trombone Literature., Cason Austin Duke

LSU Historical Dissertations and Theses

In the last forty years, many new solo and chamber pieces have been written for the trombone which involve elements of a theatrical nature, including lighting, make-up, costume, stage direction, dialogue/narration, sound effects, props, and audience interaction. It is difficult for a trombonist searching for music to discern a piece's theatrical nature by its listing in most catalogs. This document has attempted to solve that problem by gathering pieces that share these elements into an annotated collection. Nearly 200 pieces were discovered through contacts made with individual trombonists, composers, and publishers around the world. Of these, over sixty were acquired …

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Synthetic Peptides: Design, Structure And Biological Function., Lars Gustav Johan Hammarstrom Jan 2001

Synthetic Peptides: Design, Structure And Biological Function., Lars Gustav Johan Hammarstrom

LSU Historical Dissertations and Theses

The synthesis of a series of polyfunctional Calpha,C alpha-disubstituted glycines is described. The lysine-like amino acid analog, Api, was prepared by regioselective hydrolysis of a triBoced hydantoin, followed by Nalpha-protection to yield the first orthogonally protected ionizable Calpha,Calpha-disubstituted amino acid which is alicyclic. The synthesis of three orthogonally protected tetrafunctional amino acids, Bap, Bglu, and Basp was envisioned by alkylation of the organic synthon ethyl nitroacetate. Subsequent regioselective modification should allow for the isolation of the first tetrafunctional amino acid derivatives suitable for solid-phase synthesis. These amino acids are designed to induce peptide secondary structure by salt-bridge stabilization. A series …

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The Influence Of Agricultural Policy On Economic Integration Among Central American Countries: A Game Theoretic Analysis., Jorge Luis Icabalceta Mairena Jan 2001

The Influence Of Agricultural Policy On Economic Integration Among Central American Countries: A Game Theoretic Analysis., Jorge Luis Icabalceta Mairena

LSU Historical Dissertations and Theses

The influence of eight commodity groups on international economic integration in five Central American countries are analyzed. The commodity groups are rice, beans, corn, sorghum, bananas, coffee, sugar, and beef. The countries are Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua. A game theory framework is used to find a Nash equilibrium solution to a set of trade negotiation scenarios. The payoffs of the Political Preference Function (PPF) are used for the trade liberalization scenarios under analysis. These PPF payoffs are estimated using the MISS model. The nominal protection coefficient (NPC) is used as the main criterion for trade liberalization. …

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Benthic Foraminifera In Two Stressed Environments Of The Northern Gulf Of Mexico., Emil Platon Jan 2001

Benthic Foraminifera In Two Stressed Environments Of The Northern Gulf Of Mexico., Emil Platon

LSU Historical Dissertations and Theses

This is a study of Foraminifera from two stressed environments of the northern Gulf of Mexico: one of coastal seasonal hypoxia, the other of hydrocarbon seeps in bathyal depths---oxygen depletion being the common stressor. Many species of benthic Foraminifera survive the extreme oxygen depletion of Louisiana shelf waters in spring and summer. The dominant species are infaunal and have an adaptive tolerance to near anoxia or anoxia. A census of foraminiferal species present in dated sediment core samples reveals significant changes in the composition of the Louisiana-shelf benthic foraminiferal community in the past century. Agglutinated and porcelaneous orders living in …

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Middle School Students' Understanding Of The Natural History Of The Earth And Life On Earth As A Function Of Deep Time., Azalie Cecile Pulling Jan 2001

Middle School Students' Understanding Of The Natural History Of The Earth And Life On Earth As A Function Of Deep Time., Azalie Cecile Pulling

LSU Historical Dissertations and Theses

The purpose of this study was to use deep time, that is geologic time as a mechanism to explore middle school students' understanding of the natural history of the earth and the evolution of life on earth. Geologic time is a logical precursor to middle school students' understanding of biological evolution. This exploratory, mixed model study used qualitative and quantitative methods in each stage of the research to explore sixth grade students, understanding of geologic time, their worldviews (e.g., conceptual ecology), and conceptual change. The study included fifty-nine students in the large group study and four case studies. The primary …

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Systemic And Colonic Hemodynamic And Vasomotor Responses To Adenosine Triphosphate In Horses., Joanne Tetens Jan 2001

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 …

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Natural History And Phytogeography Of The Loess Hills And Ravines, Lower Mississippi Embayment., Igor Igorevich Ignatov Jan 2001

Natural History And Phytogeography Of The Loess Hills And Ravines, Lower Mississippi Embayment., Igor Igorevich Ignatov

LSU Historical Dissertations and Theses

Although located near the middle of the Southeastern Coastal Plain, the hardwood forests of the Loess Hills of the Lower Mississippi Embayment have never been thoroughly studied or satisfactorily described in the literature. This dissertation is a case study of the biogeographic variation in the species composition and structure of the mature ravine hardwood forests within the southern section of the Loess Hills, from Warren County, Mississippi, south to East Baton Rouge and Vermilion Parishes, Louisiana, as affected by latitude, physiography, edaphic conditions, and disturbance. A parallel goal is, on the basis of the current biogeographic conditions and successional dynamics, …

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Physiology And Lateralization Of Swallowing: A Comparison Between Young And Old Adults., Stephanie Kay Daniels Jan 2001

Physiology And Lateralization Of Swallowing: A Comparison Between Young And Old Adults., Stephanie Kay Daniels

LSU Historical Dissertations and Theses

Age-related changes in discrete swallows have been well researched, but few studies have investigated sequential swallowing with little emphasis on age-related changes. It is also unclear whether the cortical representation of swallowing is lateralized to one hemisphere or is bilaterally represented. As such, the aims of this research were to examine deglutitive biomechanics of sequential straw swallowing (Experiment I), and study swallowing lateralization using a dual task paradigm in healthy, young and old adults (Experiment II). Thirty-eight right-handed men (young = 20, old = 18) were studied. Experiment I: Videofluoroscopic swallow samples of two 10-second straw drinking trials were obtained. …

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Effect Of Chromium, Dried Brewers Yeast, And Mannan Oligosaccharides On Sow Productivity And Growth Performance Of Weanling Pigs., Frederick Masson Lemieux Jr Jan 2001

Effect Of Chromium, Dried Brewers Yeast, And Mannan Oligosaccharides On Sow Productivity And Growth Performance Of Weanling Pigs., Frederick Masson Lemieux Jr

LSU Historical Dissertations and Theses

Five experiments were conducted to evaluate the effects of mannan oligosaccharides (Bio-Mos) on growth performance, carcass characteristics, and pork quality of pigs. The first two experiments evaluated 0.20 and 0.30% Bio-Mos. The data indicated that the 0.20% level of Bio-Mos was more effective, and this level was used in the remainder of the experiments. Interactive effects of Bio-Mos and excess dietary Zn were evaluated in Exp. 2 and 3 and Trial 2 of Exp. 4. In Trial 1 of Exp. 4, Bio-Mos was fed with and without an antibiotic. In addition to the weanling pig experiments, 0.30% Bio-Mos was fed …

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An Inquiry Into The Influence Of Taped Books On The Oral Reading Performance Of Struggling Third-Grade Readers., Dolores Doga Harris Jan 2001

An Inquiry Into The Influence Of Taped Books On The Oral Reading Performance Of Struggling Third-Grade Readers., Dolores Doga Harris

LSU Historical Dissertations and Theses

The purpose of the nine-week study was to explore, using taped book intervention, the oral reading fluency of six struggling third-grade readers. The low-income, inner city, African American students were selected using teacher recommendations, standardized test scores, and the school system's Grade Level Indicators of Essential Knowledge---Grade 3 English Language Arts. Procedures used in the study were observing, collecting field notes, reviewing documents, conducting open-ended interviews, prioritizing book selection interests, and making assessments. Pre- and post-intervention assessments included the following: (1) oral reading rate---the Gray Oral Reading Test-3 (GORT-3), two-minute timed readings, and Corduroy benchmark probes; (2) word recognition---Slosson Oral …

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Ways Of Incorporating Photographic Images In Learning And Assessing High School Biology: A Study Of Visual Perception And Visual Cognition., Brenda Chaumont Nixon Jan 2001

Ways Of Incorporating Photographic Images In Learning And Assessing High School Biology: A Study Of Visual Perception And Visual Cognition., Brenda Chaumont Nixon

LSU Historical Dissertations and Theses

This study evaluated the cognitive benefits and costs of incorporating biology-textbook and student-generated photographic images into the learning and assessment processes within a 10th grade biology classroom. The study implemented Wandersee's (2000) 20-Q Model of Image-Based Biology Test-Item Design (20-Q Model) to explore the use of photographic images to assess students' understanding of complex biological processes. A thorough review of the students' textbook using ScaleMaster R with PC Interface was also conducted. The photographs, diagrams, and other representations found in the textbook were measured to determine the percentage of each graphic depicted in the book and comparisons were made to …

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Physicochemical, Functional And Spectroscopic Analysis Of Crawfish Chitin And Chitosan As Affected By Process Modification., Sandeep Kumar Rout Jan 2001

Physicochemical, Functional And Spectroscopic Analysis Of Crawfish Chitin And Chitosan As Affected By Process Modification., Sandeep Kumar Rout

LSU Historical Dissertations and Theses

Traditional isolation of chitin from crawfish shells involves three sequential steps: demineralization (DM, removing calcium carbonate/phosphate), deproteinization (DP), and decolorization (DC, removing mainly astaxanthin). The first two steps can be reversed (i.e., DMP or DPM). Chitin is converted to chitosan by deacetylation (DA). Isolation steps may be shortened, depending on intended applications of chitosan. The first study investigated effects of (1) reversing sequence and (2) eliminating DP and DC steps on physicochemical and functional properties of chitosan and conversion efficiency of chitin. Twelve different processes: DM, DP, DPM, DMP, DPMC, DMPC, DMA, DMCA, DPMA, DMPA, DPMCA, DMPCA were investigated. DA …

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