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Techniques For The Optimization Of Supercritical Fluid Chromatographic Separations., Jeffrey Alan Crow Jan 1991

Techniques For The Optimization Of Supercritical Fluid Chromatographic Separations., Jeffrey Alan Crow

LSU Historical Dissertations and Theses

Although supercritical fluid chromatography (SFC) is now well established and still growing rapidly, it must offer clear advantages over other techniques. Thus proper method development in SFC is a necessity. There are many diverse and synergetic parameters controlling SFC separations, resulting in complex retention behavior. This work describes the proper approach to method development, including investigations into unique mobile phases and some techniques which can be used for optimization of SFC separations. In Chapter One, the concepts of chromatography with supercritical fluids are first introduced, including method development and optimization. Chapter Two focuses on mobile phase method development, and examines …

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Modeling Of Physical Database Design And Performance Analysis With Emphasis On Vsam Files., Sung-Eon Kim Jan 1991

Modeling Of Physical Database Design And Performance Analysis With Emphasis On Vsam Files., Sung-Eon Kim

LSU Historical Dissertations and Theses

Growth in the size of a database is reflected in deterioration of database performance. Since deterioration is related to the structure of the file, the performance efficiency involves the design of a physical database and the proper management of it. This research addresses a modeling procedure of a physical database design considering both records insertions and deletions. The model describes the behavior of a physical database in a VSAM file environment, and is extended to the issue of database reorganization through a cost analysis. The cost of accessing the database increases due to the physical disorganization of the database caused …

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The Frost Tolerance Of Tobacco Plants Transformed With The Gene Encoding The Antifreeze Protein From Winter Flounder., Jung-Sook Lee Jan 1991

The Frost Tolerance Of Tobacco Plants Transformed With The Gene Encoding The Antifreeze Protein From Winter Flounder., Jung-Sook Lee

LSU Historical Dissertations and Theses

The winter flounder, Pseudopleuronectes americanus, can survive in sea water at temperatures below freezing by producing antifreeze-proteins (AFPs) which depress the freezing point of their cellular fluids. The antifreeze gene (IIA7 cDNA) encodes a 91 amino acid preproprotein which is processed to a mature protein of 53 amino acids. This gene encoding only the mature antifreeze-protein, including a start methionine, was cloned into a plasmid which allowed enhanced expression from a double CaMV 35S promoter. The AFP gene construct was subcloned into both the intermediate vector pMON200 and the binary vector pBI121. After triparental mating and infection of tobacco leaf …

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The Variable Learning Effects Of Two Types Of Intervention On L2 Communication Skills Using Interactive Tasks., Margaret Ann Powers Jan 1991

The Variable Learning Effects Of Two Types Of Intervention On L2 Communication Skills Using Interactive Tasks., Margaret Ann Powers

LSU Historical Dissertations and Theses

This study evaluated the benefits of a task-based procedure used to develop L2 communicative effectiveness in spoken English among a group of advanced proficiency learners. Using two interactive information-exchange map tasks, one diagram task, and two intervening discussion sessions, the study attempted to investigate the actual communicative outcomes of interaction prompted by the tasks and by the interventions. Subjects in three conditions first performed a map task designed with four referential problems which had to be solved to successfully complete the task. Immediately following the map task, the subjects in the first condition participated in a discussion session in which …

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Nuclear Transplantation: Intracellular Release And Extracellular Influx Of Calcium In Response To Electrofusion Pulse And Its Effect On Murine Oocyte Activation And Embryonic Development., Lee F. Rickords Jan 1991

Nuclear Transplantation: Intracellular Release And Extracellular Influx Of Calcium In Response To Electrofusion Pulse And Its Effect On Murine Oocyte Activation And Embryonic Development., Lee F. Rickords

LSU Historical Dissertations and Theses

The transplantation of early embryonic cell nuclei into oocytes in which the maternal chromosomes have been removed is a method by which multiple offspring of the same genotype can be produced. One critical factor required for successful development of nuclear transfer derived embryos is inducing the release of the recipient ooplasm from meiotic arrest (activation). This is accomplished during fusion of the two cells. The DC electrofusion pulse used to fuse the two cells together also activates the recipient ooplasm to resume meiotic events, however, the efficiency of electrofusion pulse induced activation remains low. It is known that activation of …

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Student Thought Processes And Quality Of Practice During Motor Skill Instruction., Melinda Ann Solmon Jan 1991

Student Thought Processes And Quality Of Practice During Motor Skill Instruction., Melinda Ann Solmon

LSU Historical Dissertations and Theses

The focus of this study was the examination of relationships between initial skill level, observer estimates of attention, student thoughts, quality of practice, and achievement during motor skill instruction. Specifically, the following questions were addressed: (1) What is the relationship between observed student behavior to quality of practice and achievement? (2) What is the relationship between student reports of their cognitive processes to quality of practice and achievement? (3) Does written self-report data produce the same information as data collected during stimulated recall interviews? and (4) Are student self-report data about attention consistent with observer estimates of overt student behavior? …

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Consistency And Stability For Linear Finite Difference Approximations, Cabe W. Chadick Jan 1991

Consistency And Stability For Linear Finite Difference Approximations, Cabe W. Chadick

Honors Capstones

No abstract provided.

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The Differential Effects Of Either X-Irradiation Or Thermal Stress On The Two Major Cell Types Of The Blastocyst Stage Murine Embryo., Joe Steve Capehart Jan 1991

The Differential Effects Of Either X-Irradiation Or Thermal Stress On The Two Major Cell Types Of The Blastocyst Stage Murine Embryo., Joe Steve Capehart

LSU Historical Dissertations and Theses

The first objective of this investigation was to determine if either X-irradiation or thermal stress exerted differential effects on the two major cell types of the blastocyst stage murine embryo. Results of this study indicate that X-irradiation dosages of 0 rads, 500 rads, 600 rads, 700 rads, 800 rads, 900 rads or 1000 rads had no effect on the ability of treated embryos to either hatch or develop into trophoblastic outgrowths (P $<$.05). In contrast, X-irradiation treatment over the levels tested did have a detrimental effect on the ability of embryos to develop into trophblastic outgrowths possessing an ICM region (P $>$.05). X-irradiation over the levels tested had no effect on the mean two-dimensional outgrowth surface areas ($\mu$m$\sp2$) (P $>$.05). However, X-irradiation was found to have a …

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Study On Two Chitin-Binding Proteins From Vibrio Parahaemolyticus., Otto Silva Gildemeister Jan 1991

Study On Two Chitin-Binding Proteins From Vibrio Parahaemolyticus., Otto Silva Gildemeister

LSU Historical Dissertations and Theses

Two chitin-binding proteins from Vibrio parahaemolyticus are secreted into the culture medium after the addition of chitin or oligomers of N-acetylglucosamine, but only to lower levels of expression with a few other saccharides. The first protein exhibited a very salt-resistant chitinase activity with activity maxima at pH 6 and 9. The enzyme is stable for 30 minutes at 40$\sp\circ$C, and maximal activity is reached at 50$\sp\circ$C. The chitinase hydrolyzes optimally chitin oligomer substrates with degree of polymerization of 4 and higher. The hydrolytic activity upon the chitotrimer is low; the dimer cannot be hydrolyzed by the enzyme. When incubated with …

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Solution Adaptive Grid Procedures For High-Speed Parabolic Flows., Albert Destrehan Harvey Iii Jan 1991

Solution Adaptive Grid Procedures For High-Speed Parabolic Flows., Albert Destrehan Harvey Iii

LSU Historical Dissertations and Theses

A solution-adaptive grid procedure based on an error equi-distribution scheme is developed and applied to a Parabolized Navier-Stokes solver. The adaptation scheme re-distributes grid points line-by-line, with grid point motion controlled by forces analogous to tensional and torsional spring forces with the tensional spring force at a point proportional to the error estimate. Where the error estimates are large, the tensional forces become high and drive grid points to cluster in these high error estimate regions. Torsional terms are functions of the grid point positions along neighboring grid lines and provide grid smoothness and orthogonality. A method of selecting error …

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Prewriting, Drafting, And Revision In Large Scale Writing Assessment. (Volumes I And Ii)., Arthur Marshall Halbrook Jan 1991

Prewriting, Drafting, And Revision In Large Scale Writing Assessment. (Volumes I And Ii)., Arthur Marshall Halbrook

LSU Historical Dissertations and Theses

The purpose of this study was to examine prewriting, drafting, and revision in a large scale writing assessment. In April 1989, Louisiana administered a graduation exit examination. Written composition comprised one of the three testing components. From the 40,000 tenth grade students who participated in the written composition test, a stratified sampling of 1,467 was selected for this study. Using a research design incorporating both quantitative and qualitative assessment procedures, the study examined prewriting, drafting, and revision practices at two levels. In Level I, the first and final drafts of the 1,467 students were analyzed using a scoring model derived …

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An Analysis Of Educational Films: An African-American Perspective. (Volumes I And Ii)., Brenda Garibaldi Hatfield Jan 1991

An Analysis Of Educational Films: An African-American Perspective. (Volumes I And Ii)., Brenda Garibaldi Hatfield

LSU Historical Dissertations and Theses

Historically African-Americans have been marginalized and subordinated in critical discourse and research in curriculum studies and educational media. There is a vital need for research directed toward African-Americans as subjects and viewers of media used in school curricula. Cultural theorists in curriculum and educational media studies are interested in knowing how social, political and ideological messages are produced and circulated in society, and how student audiences use them to make sense of their experiences. The purpose of this research is to contribute to a better understanding of how racial representations and social identities are coded and produced in educational films, …

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Fatigue Failure Of Composite Bolted Joints., Paul Douglas Herrington Jan 1991

Fatigue Failure Of Composite Bolted Joints., Paul Douglas Herrington

LSU Historical Dissertations and Theses

The objective of this study is to investigate the fatigue behavior of a double-lap, bolted composite joint. The material used for all tests is a quasi-isotropic graphite-epoxy laminate. Prior to fatigue testing, monotonic loading tests were performed in order to establish the important fundamental properties of friction coefficients and the ultimate bearing strength of composite joints. Proper design of friction type bolted joints for composite materials accounts for the force transmitted through friction between the clamped materials. This consideration requires knowledge of the coefficient of friction between the mating surfaces of the bolt, or washer, and the composite material. In …

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Louisiana Principals' Perceptions Of Nontraditional Vocational Teachers And The Importance Of Vocational Education., Moo Yul Huh Jan 1991

Louisiana Principals' Perceptions Of Nontraditional Vocational Teachers And The Importance Of Vocational Education., Moo Yul Huh

LSU Historical Dissertations and Theses

Even though the elimination of sex bias and stereotyping has been a national priority in vocational education for a number of years, many educators or administrators still hold sex biased and stereotyped attitudes about labor force participation and have a belief that there are "men's" and "women's" jobs. A study of sources affecting sex bias and sex stereotyping of vocational teachers is critical to provide more productive programs. The local school principal typically has the greatest impact on school level employment decisions because the principal is the chief executive officer or administrator of the basic unit in the school system. …

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School Centralization And Organizational Effectiveness: The Role Of Teacher Alienation., Bobby L. Johnson Jr Jan 1991

School Centralization And Organizational Effectiveness: The Role Of Teacher Alienation., Bobby L. Johnson Jr

LSU Historical Dissertations and Theses

The focus of educational reform in recent years has shifted to the restructuring of schools. Many reformers have defined restructuring in terms of the decentralization of power within schools (Elmore et al., 1990). Yet, there is little research to suggest how such decentralization will affect teachers and improve schools. Given this scarcity, the purpose of this study was to explore the relationships between the degree of centralized decision-making which exists in a school, teachers' cognitive and affective work alienation, and multiple indices of school effectiveness. Such relationships were examined within the context of Seeman's (1972) framework of social change as …

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The Evaluation And Comparison Of Aquatic Methodology For Measurement Of Bacterial Population Dynamics And Grazing Activity In Diverse Aquatic Ecosystems., Richardus F. Kaswadji Jan 1991

The Evaluation And Comparison Of Aquatic Methodology For Measurement Of Bacterial Population Dynamics And Grazing Activity In Diverse Aquatic Ecosystems., Richardus F. Kaswadji

LSU Historical Dissertations and Theses

Observations and experiments were conducted to evaluate methodologies for measuring aquatic bacterial population dynamics and grazing activity in ecologically dissimilar ecosystems. Samples were taken from Auke Bay, AK, the Mississippi River at Plaquemine, LA, the Terrebonne Bay estuary, LA, and the Mississippi River plume. Four methods were compared for measuring bacterioplankton growth and grazing mortality rates: dilution, filtration, antibiotic, and the Servais et al. (1985) procedures. The dilution method appeared to be the best among those compared. Among all sites, bacterial density ranged from 0.02 to 10$\sp6$ ml$\sp{-1}$, and bacterial growth and grazing mortality rates, estimated using the dilution method, …

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Valuation Of Firm-Bank Relationships: A Test Of The Delegated Monitoring Hypothesis., Shane Alan Johnson Jan 1991

Valuation Of Firm-Bank Relationships: A Test Of The Delegated Monitoring Hypothesis., Shane Alan Johnson

LSU Historical Dissertations and Theses

In this thesis, we test the hypothesis that banks provide monitoring services that benefit client firm shareholders. We argue that if the value of firm-bank relationships stems from monitoring services provided by banks, then share price responses associated with announcements of bank loans should be cross-sectionally related to variables that proxy the degree of monitoring to which firms are already subject. Our sample differs from previous studies of bank debt announcements in two key aspects: inclusion of NASDAQ firms, and inclusion of announcements carried by the newswire but not the Wall Street Journal. Consistent with suggestions by Fama (1985) and …

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Characterization And Potential Utilization Of Proteases From The Hepatopancreas Of Crawfish, Procambarus Clarkii., Hyeung-Rak Kim Jan 1991

Characterization And Potential Utilization Of Proteases From The Hepatopancreas Of Crawfish, Procambarus Clarkii., Hyeung-Rak Kim

LSU Historical Dissertations and Theses

Four electrophoretically homogenous anionic trypsins, tentatively named trypsin A, B, C, and D, were isolated from crawfish hepatopancreas. Purity was increased 56, 100, 87, and 64-fold with approximately 2.4, 8.1, 5.1, and 3.0% yield for trypsin A, B, C, and D, respectively. The molecular weights of trypsin A, B, C, and D were estimated to be 23,800, 27,900, 24,800, and 31,400, respectively, using Sephacryl S-200 gel filtration. Isoelectric points and amino acid profiles of the trypsins were similar. Caseinolytic activity was consistently highest between pH 5.5 and 10.0 for all trypsins. Amidolytic and esterolytic activities were maximum in a narrower …

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Parallel Computation On Hypercube-Like Machines., Kyung Hee Kwon Jan 1991

Parallel Computation On Hypercube-Like Machines., Kyung Hee Kwon

LSU Historical Dissertations and Theses

The hypercube interconnection network has been recognized to be very suitable for a parallel computing architecture due to its attractive topological properties. Recently, several modified hypercubes have been propose to improve the performance of a hypercube. This dissertation deals with two modified hypercubes, the X-hypercube and the Z-cube. The X-hypercube is a variant of the hypercube, with the same amount of hardware but a diameter of only $\lceil$(n + 1)/2$\rceil$ in a hypercube of dimension n. The Z-cube has only 75 percent of the edges of a hypercube with the same number vertices and the same diameter as the hypercube. …

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Effects Of Alternative Protein And Fat Payment Plans On Production Variables And Returns In Louisiana Dairy Herds., Leonder Labbe Jan 1991

Effects Of Alternative Protein And Fat Payment Plans On Production Variables And Returns In Louisiana Dairy Herds., Leonder Labbe

LSU Historical Dissertations and Theses

Multiple linear regression was used to compare the impact of proposed multiple component milk pricing systems with the present milk pricing system for Louisiana Holstein herds on DHIA. Dependent variables were milk yield, fat yield, protein yield, six income over feed cost pricing systems, and six product value pricing systems. Independent variables were herd, year, and month as class variables and 18 production variables. Data were 16,675 herd-year-month observations of Louisiana Holsteins from DHIA monthly Herd Summary DHI-202 computer files. Pricing data was standardized using prices form the New Orleans - Mississippi Federal Milk Marketing Order 1094, Zone 1. The …

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Functional Morphology Of Gustatory Centers In The Brain Of The Channel Catfish, Ictalurus Punctatus., Charles Franklin Lamb Iv Jan 1991

Functional Morphology Of Gustatory Centers In The Brain Of The Channel Catfish, Ictalurus Punctatus., Charles Franklin Lamb Iv

LSU Historical Dissertations and Theses

Gustatory nuclei in the isthmic region of the metencephalon and in the posterior diencephalon of the channel catfish, Ictalurus punctatus, were examined anatomically and electrophysiologically. Neurons in the superior secondary gustatory nucleus (nGS) responded to taste and tactile stimulation of large peripheral receptive fields (RFs) that often included the epithelia of the oropharyngeal cavity and whole extraoral body surface. Taste responses to amino acids and nucleotides were dose-dependent, with detected thresholds from micromolar to millimolar concentrations. The RF organization within the nGS did not display the somatotopy present in the medullary gustatory nuclei. Anatomical labeling of secondary gustatory fibers showed …

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Picosecond Pump-Probe Raman Spectroscopy Of Excited States And Relaxation Phenomena In The Condensed Phase., Robert Lingle Jr Jan 1991

Picosecond Pump-Probe Raman Spectroscopy Of Excited States And Relaxation Phenomena In The Condensed Phase., Robert Lingle Jr

LSU Historical Dissertations and Theses

This dissertation describes the development and application of pump-probe Raman spectroscopy using 8 ps laser pulses as a technique for the study of relaxation phenomena in the condensed phase. I show three examples of systems studied by this technique. First, the dissipation of the heat deposited in the cage of solvent molecules surrounding a photodissociated diatomic solute is directly measured in the solvent Raman spectrum. Second, we provide a full characterization of the excited $A\sp\prime$ state of iodine which is formed in solution following photodissociation. This work discusses the solvent dependence of the iodine atom recombination process and points toward …

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The Form And Function Of Constructed Dialogue In Reported Discourse., Terrie Dawn Mathis Jan 1991

The Form And Function Of Constructed Dialogue In Reported Discourse., Terrie Dawn Mathis

LSU Historical Dissertations and Theses

In this study of constructed dialogue in natural conversations involving four American women, attention is drawn to how reporting speakers make use of different quotative forms to introduce utterances represented with direct speech forms. There is an attempt to account for the functions of such quotative forms in terms of discourse structure and the interpersonal relationships of the participants. In one closely-examined narrative, the present tense forms of several quotatives (is, says, goes, and be like) are used to introduce constructed dialogue which seems to be that part of the narrative that the speaker intends to foreground, while the past …

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"Spades Players" And "Senators": An Ethnography Of Black Subcultures In A Community College., Anthony Louis Molina Sr Jan 1991

"Spades Players" And "Senators": An Ethnography Of Black Subcultures In A Community College., Anthony Louis Molina Sr

LSU Historical Dissertations and Theses

This ethnographic study of Black community college students, in a predominantly white community college, took place over a three-year period and focused on two groups. One group, the spades players, neglected their studies in favor of the card game spades, which they made the central activity of their family-like collective in the student commons. The other group, Black senators in the Student Government Association, were academic achievers who performed service to the college. By immersion into both cultures, the researcher gained the confidence of individual students in both groups, interviewed them in various settings, and looked for reasons behind the …

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New Techniques In Scene Understanding And Parallel Image Processing., Krishnakumar Narayanan Jan 1991

New Techniques In Scene Understanding And Parallel Image Processing., Krishnakumar Narayanan

LSU Historical Dissertations and Theses

There has been tremendous research interest in the areas of computer and robotic vision. Scene understanding and parallel image processing are important paradigms in computer vision. New techniques are presented to solve some of the problems in these paradigms. Automatic interpretation of features in a natural scene is the focus of the first part of the dissertation. The proposed interpretation technique consists of a context dependent feature labeling algorithm using non linear probabilistic relaxation, and an expert system. Traditionally, the output of the labeling is analyzed, and then recognized by a high level interpreter. In this new approach, the knowledge …

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The Structural Organization Of Photosystem Ii Polypeptides., William Robert Odom Jan 1991

The Structural Organization Of Photosystem Ii Polypeptides., William Robert Odom

LSU Historical Dissertations and Theses

The structural organization of Photosystem II polypeptides has been investigated using the protein crosslinking reagent 1-ethyl-3-(dimethyl-aminopropyl)-carbodiimide (EDC), and a library of mono- and polyclonal antibodies. The first phase of this research was to generate the antibody probes against specific PS II polypeptides. A murine monoclonal antibody, FQC3, was characterized. It recognized the D2 protein of Spinacia oleracea L. The second phase of this research utilized antibodies against D1, D2, CPa-1, CPa-2, Cyt b$\sb{559}$, 33 kDa manganese stabilizing protein (MSP), 24 kDa extrinsic protein, and the 17 kDa extrinsic protein to identify PS II subunits crosslinked by EDC. Several intra-complex crosslinked …

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Chromium, Tryptophan, And Picolinate In Diets For Pigs And Poultry., Timothy Guinn Page Jan 1991

Chromium, Tryptophan, And Picolinate In Diets For Pigs And Poultry., Timothy Guinn Page

LSU Historical Dissertations and Theses

Six experiments were conducted to evaluate the effects of supplemental dietary tryptophan (TRP), picolinate (Pic), CrCl$\sb3\cdot$6H$\sb2$O, chromium picolinate (CrPic), or a combination of Pic and CrCl$\sb3\cdot$6H$\sb2$O on growth performance, liver mineral concentrations, insulin, growth hormone, organ weights, and serum and carcass traits of pigs. One experiment was conducted to evaluate the effect of chromium picolinate (CrPic) on serum cholesterol (CH), egg CH, egg quality, and egg production of laying hens. Dietary TRP, Pic, CrCl$\sb3\cdot$6H$\sb2$O, and a combination of Pic and CrCl$\sb3\cdot$6H$\sb2$O did not affect growth performance, liver mineral concentrations, insulin, growth hormone, and serum and carcass traits of pigs. The …

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Efficient Data Structures And Algorithms For Scientific Computations., Soon Cheol Park Jan 1991

Efficient Data Structures And Algorithms For Scientific Computations., Soon Cheol Park

LSU Historical Dissertations and Theses

Large-scale numerically intensive scientific applications can require tremendous amounts of computer time and space. Two general methods are presented for reducing the computer resources required in scientific computing. The first is a numerical database system which is built on a space and time optimal data structure called a weighted search tree and that allows for the storage and retrieval of valuable intermediate information so costly redundant calculations can be avoided. The second is a matrix algorithm based on a new space optimal representation of sparse matrices that for typical scientific applications can be expected to dramatically decrease the cost of …

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Factors Controlling The Distribution Of The Black Mangrove, Avicennia Germinans L., In A Louisiana Mangal/Salt Marsh Community., Charles Stuart Patterson Jan 1991

Factors Controlling The Distribution Of The Black Mangrove, Avicennia Germinans L., In A Louisiana Mangal/Salt Marsh Community., Charles Stuart Patterson

LSU Historical Dissertations and Theses

Mangroves are intertidal, halophytic trees limited to the tropics and subtropics because they are not cold-tolerant. In coastal Louisiana (29$\sp\circ$ N latitude), the black mangrove, Avicennia germinans, is the only mangrove found because Avicennia is the most cold-tolerant of mangrove genera. Avicennia intergrades with salt marsh cordgrass, Spartina alterniflora, with 3 observed zones: an Avicennia zone, a transition zone, containing both Avicennia and Spartina, and a Spartina zone. The purpose of this dissertation was to determine why A. germinans does not occur in the Spartina zone within a mangal/salt marsh ecotone. Three studies investigated the following zone differences in: (1) …

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The Alkaloids Of Erythrina: Clonal Evaluation And Metabolic Fate., Lori Denise Payne Jan 1991

The Alkaloids Of Erythrina: Clonal Evaluation And Metabolic Fate., Lori Denise Payne

LSU Historical Dissertations and Theses

The foliage of thirteen genetic clones of the nitrogen-fixing trees Erythrina berteroana, E. poeppigiana and E. costarricensis growing under similar environmental conditions in the Latin American Nitrogen Fixing Tree Arboretum, CATIE, Turrialba, Costa Rica, was evaluated by gas chromatography/mass spectrometry for toxic alkaloid content. The major alkaloid identified was $\beta$-erythroidine, a naturally derived drug used in the 1950s and 1960s as a neuromuscular blocking agent in surgery and electroshock treatments. Other alkaloids identified were $\alpha$-erythroidine, erybidine, erythraline, erysodine, oxo-$\beta$-erythroidine and several previously undescribed compounds. There was a difference of more than two orders of magnitude in the $\beta$-erythroidine concentration between …

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