Digital Commons Network^™

A 4,000 Year Pollen Record Of Vegetation Changes, Sea Level Rise, And Hurricane Disturbance In Atchafalaya March Of Southern Louisiana, Xinyu Zhou

LSU Historical Dissertations and Theses

Sediment cores from the Atchafalaya Marsh in southern Louisiana were intensively studied by means of pollen and loss-on-ignition analyses to reconstruct the history of late-Holocene environmental changes and hurricane strikes in the area. The data indicate that the coring site was occupied by a fresh marsh about 4000 years ago. Afterwards, the fresh marsh was replaced by a brackish marsh in the following 400 years. The marsh became a salt marsh in response to sea level rise beginning 3250 yr BP. During 2800-1200 yr BP, the study site became an estuarine environment inundated by sea water as a result of …

Join In The Dance: Didacticism In Jane Austen's Pride And Prejudice, Lisa Morales

LSU Historical Dissertations and Theses

The importance of didacticism in Jane Austen’s Pride and Prejudice may sometimes be overlooked in an effort to be entertained by the fairy-tale essence of her work. This is unfortunate since Pride and Prejudice offers a rich critique of eighteenth-century English society, as well as heralds the beginning of a new form of novel writing. This new form of novel writing includes a vision of an autonomous heroine who exercises freedom from patriarchal society and the “marriage market.” Austen’s ironic didacticism in Pride and Prejudice highlights hypocrisy and contradiction, and in so doing, mock social expectations. It is through her …

Synthesis Of Novel Amino Acids And 310- And Alpha-Helical Alpha, Alpha-Disubstituted Amino Acid Rich Antimicrobial Peptides, Thomas Scott Yokum

LSU Historical Dissertations and Theses

Amphipathic peptides rich in α, α-disubstituted amino acids (ααAAs) were synthesized and examined for antimicrobial activity and helix preference in various solvent systems. Also, a series of polar, ααAAs were synthesized for incorporation into helical peptides and a red-shifted tryptophan analog was synthesized as a fluorescent probe.

A series of short, amphipathic, 3₁₀- and α-helical peptides containing 50 to 80 percent ααAAs was synthesized. Various combinations of 1-aminocyclohexane-lcarboxylic acid, α-aminoisobutyric acid, and 4-aminopiperidine-4-carboxylic acid were incorporated using preformed acid fluorides. In vitro testing revealed that most of these peptides show direct antibacterial activity against E. coli and …

Sand Body Geometry Of The Wax Lake Outlet Delta Atchafalaya Bay, Louisiana, Susan Majersky Fitzgerald

LSU Historical Dissertations and Theses

Deltas forming in Atchafalaya Bay, L-ouisiana, are the result of delta switching by the Mississippi River. The larger Lower Atchafalaya River delta has been heavily manipulated by dredging for navigation, but the Wax Lake Outlet delta is largely undisturbed and an excellent example of a 'bayhead' delta. Combining stratigraphy, aerial photography and digital terrain model data sets, the developmental history of this delta is presented. The Wax Lake Outlet delta is comprised of a typical upward-coarsening sequence, although its prodelta unit is extremely limited. Its plan-view form is typical of deltas developing in low-energy, unstratified, shallow basins. Early developmental processes …

Aspects Of Searching And Tunneling Behavior In Resource Utilization By The Formosan Subterranean Termite, Coptotermes Formosanus Shiraki., Justin Carl Hedlund

LSU Historical Dissertations and Theses

Formosan subterranean termites, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), were acclimated with different masses of pine or no wood (control) and then allowed access to a thin sand filled tunneling chamber. As available pine increased, termite survival and food consumption increased but search tunnel volume decreased. Increased food size resulted in termites excavating fewer exploratory tunnels due to decreases in secondary and tertiary branch tunnels. An increase in food size also decreased the total length of a search tunnel network, due to decreases in primary and secondary branch order lengths. Search tunnel networks had proportionally more length devoted to primary tunnels …

United States Foreign Policy And Media Coverage Of Uzbekistan: A Case Study., Mardon Nigmatovich Yakubov

LSU Historical Dissertations and Theses

This study reviews the impact of U.S. political interests on media coverage of Uzbekistan, a Central Asian republic which became independent after the breakup of the Soviet Union. A content analysis of coverage from 1991 to 1996 in the New York Times, Washington Post, and Los Angeles Times was compared to American government documents and pronouncements on Uzbekistan. Striking similarities between U.S. policy towards Uzbekistan and the negative interpretation of events appearing in American newspapers were found. The democracy and human rights agendas advanced by U.S. officials apparently prompted editors and reporters to focus more on these subjects, while overlooking …

Effects Of Selected Polycyclic Aromatic Hydrocarbons On Cell Proliferation, Protein Phosphorylation, And Intracellular Calcium Concentration In Lepomis Macrochirus., Helen Runnels Connelly

LSU Historical Dissertations and Theses

Polycyclic aromatic hydrocarbons (PAH) have been demonstrated to affect signal transduction in higher vertebrates. In this research, the freshwater species of fish, Lepomis macrochirus (bluegill) was used to test the effects of a 14-day diet of PAH on lymphocyte signal transduction. PAH tested included: 2-aminoanthracene (2-AA), 2-methylnaphthalene (2-MN), 9,10-dimethylanthracene (9,10-DMA), and a mixture of these three compounds (MIX). Individual compounds were tested at a total PAH dose of 3.1 $\pm$ 0.01mg over the 14 day period. The MIX diet was a total PAH dose of 0.13 $\pm$ 0.01mg 2-AA, 0.19 + 0.01mg 9,10-DMA, and 0.22 $\pm$ 0.02mg 2-MN over the …

Urban Effects On Precipitation In The Southern United States Of America., Youngeun Choi

LSU Historical Dissertations and Theses

Of the many weather conditions influenced by urban areas, precipitation is one of the most controversial and unsolved elements in characterizing the urban climate. The purpose of this dissertation was to identify anomalies in precipitation totals and frequencies due to urban effects and to evaluate whether certain meteorological conditions or seasons have more apparent effects. The five largest cities in the south-central United States were selected: Houston; Dallas; San Antonio; New Orleans; and Memphis. It was assumed that simple spatial analysis can detect urban effects on precipitation over and downwind of the city with a localized maximum. Trend surface analysis …

Reproductive Isolation Between Two Species Of Topminnow, Fundulus Olivaceus And F. Euryzonus., Thomas Allen Blanchard

LSU Historical Dissertations and Theses

Fundulus olivaceus and F. euryzonus are sister species that commonly occur syntopically in the Amite and Tangipahoa River drainages in Louisiana and Mississippi. Although the habitats of the two species are quite similar, and the timing of their reproductive activity overlaps extensively, no natural hybrids between them have been documented. I examined physiological, as well as behavioral, factors that could potentially serve as effective isolating mechanisms between them. The courtship and spawning behaviors of the two species were relatively generalized and showed a number of similarities. Under forced mating conditions in which females were allowed to associate with heterospecific males …

The Interactions Among The Subunits Of The Mcrbc Restriction System In E. Coli., Loganayaki Ganesh

LSU Historical Dissertations and Theses

The McrBC system of Escherichia coli K12 restricts DNA containing modified cytosines within specific sites. The modified cytosines recognized may be 5-hydroxymethylcytosine, N$\sp4$-methylcytosine or 5-methylcytosine. In the mcrBC operon, the mcrB gene is expressed to produce the McrB$\sb{\rm L}$ protein (51 kDa) and the McrB$\sb{\rm S}$ protein (33kDa), which is translated from an inframe internal translation start site and lacks the N-terminal 161 amino acids of the long product. The McrC protein is a 39kDa protein and is required for the cleavage of most methylated substrates. Using a MalE-McrB$\sb{\rm L}$ fusion protein, the endonucleolytic McrB$\sb{\rm L}$ subunit was shown to …

Assessing Applicant "Fit" Within The Selection Process: Which Interviewer Perceptions Matter?, Dawn Ebe Haptonstahl

LSU Historical Dissertations and Theses

The research literature has noted that organizations are moving beyond simply hiring individuals with the necessary knowledge, skills, and abilities (KSAs) that fulfill the requirements of the job--employers are also looking for people who can fit in with a particular work group or even an entire organization. This study tested an exploratory model that predicted recruiter selection decisions from their evaluations of applicants' person-job (P-J), person-group (P-G), and person-organization (P-O) fit. The model also postulated that P-G and P-O fit would be predicted by the perceived congruence (similarity) of work values between applicants and groups/organizations, Hypotheses were field-tested with 64 …

Characterization And Utilization Of Flavors From Undersized Crawfish., Feng Chen

LSU Historical Dissertations and Theses

Undersized processed crawfish are proposed to be a resource for effective recovery of crawfish flavors. Tail puree from undersized crawfish was hydrolyzed using protease APL-440 through response surface methodology to enrich flavor production. Optimal hydrolytic conditions were determined to be pH $8{\sim}9,\ 65\sp\circ$C, 0.3% (V/W) enzyme/substrate ratio with the reaction maintained at 33.3% puree concentration over 60 min period. Effects of storage time and extraction method on the crawfish flavor profile were evaluated. Shorter storage time gave superior flavor stocks with less oxidized flavors. The shelf-life of frozen crawfish puree was at least six months. Atmospheric simultaneous distillation-solvent extraction (A-SDE) …

Intraspecific Variation In Three Marsh Grasses In Response To Increased Flooding And Salinity., Jeannine Marie Lessmann

LSU Historical Dissertations and Theses

Intraspecific variation in response to moderate levels of flooding and salinity stress was identified in Spartina patens, S. alterniflora, and Panicum hemitomon. This analysis enabled genotypes of each species to be selected for desired traits to enhance their function in restored systems, such as increased belowground biomass to stabilize soil substrates or increased aboveground biomass to enhance sedimentation. It was also determined that increased flood tolerance conferred a greater advantage for plant growth at moderate stress levels than did increased salt tolerance. However, this growth advantage was overridden by high salinity stress, and was greatly reduced by excessive flooding stress. …

Evolutionary Effects Of Irradiation In Cataclysmic Variables., Patrick Joseph Mccormick

LSU Historical Dissertations and Theses

We developed a simple stellar computational model consisting of two concentric polytropic shells in order to investigate compact binary evolution. In this thesis we focus the investigation on the effects of irradiation on the orbital evolution of cataclysmic variables (CVs). In these systems, when the companion is illuminated by a fraction of the accretion luminosity, the orbital evolution consists of irradiation-driven limit cycles on thermal timescales. These cycles are superimposed on the secular evolution toward shorter periods due to systemic angular momentum losses. When the irradiation instability is enhanced by consequential angular momentum losses $j\sb{\rm CAML}$ the net effect is …

The Socialization Of Indian Scientific Writers Into Western Scientific Discourse Communities., Sumita Roy

LSU Historical Dissertations and Theses

This research studies the socialization of Indian science writers into western discourse communities. More specifically, it seeks to identify the writing problems that beginner Indian science writers face and the strategies that they adopt in overcoming them while writing dissertations or research articles. Primary information was gathered by interviewing 11 Indian graduate students and 17 faculty members from India (West Bengal) and the USA on the basis of a five-page questionnaire. Respondents were classified into three groups according to their places of training and writing skills. Three to five sets of rough drafts from each group were studied to note …

Pest Status Of The Fall Armyworm, Spodoptera Frugiperda (J. E. Smith), On Conventional And Transgenic Cotton Expressing The Bacillus Thuringiensis Cryia (C) Delta-Endotoxin: Development, Survival, And Host-Strain Influence., John Joseph Adamczyk Jr

LSU Historical Dissertations and Theses

The pest status of the fall armyworm, Spodoptera frugiperda (J. E. Smith), including development and survival on conventional and transgenic Bacillus thuringiensis (Bt) cotton and host-strain influences, was examined in laboratory and field studies. Neonates (1st instars) were fed leaves from conventional (cv. DP 5415 and cv. DP 5690) and transgenic Bt (cv. NuCOTN 33$\rm\sp{B}$ and cv. NuCOTN 35$\rm\sp{B})$ cotton. There were no significant differences $(P>0.05)$ between cultivars in larval mortality and survival to the pupal and adult stages. However, times to pupation and adult eclosion were significantly longer $(P<0.05)$ for larvae fed transgenic Bt cotton compared to conventional cotton. In addition, larvae weighed significantly less $(P<0.05)$ when fed transgenic Bt cotton compared to conventional cotton. A study was conducted to determine when cotton bolls become tolerant to fall armyworm injury. Fifth instars were caged individually on bolls of various ages from conventional (cv. DP 5415) and transgenic Bt (cv. NuCOTN 33$\rm\sp{B})$ cotton to define the period of boll susceptibility to larval injury. For DP 5415 bolls, there was no significant linear relationship $(P>0.05)$ describing larval mortality or successful boll penetration as …

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 …

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 …

Locus Of Reform: From Reflection To Effectiveness Through The Voices Of Novice Teachers., Patricia Babin Caillouet

LSU Historical Dissertations and Theses

This descriptive multiple-case qualitative study focused on the professional and personal experiences of five novice teachers--three preservice student teachers and two first-year teachers. Research conducted in two exemplary elementary schools examined the following questions: (a) How do preservice and first-year teachers use reflective practice and self-assessment to develop effective teaching practices? (b) How do the preservice and first-year teachers' approaches to effective literacy instruction compare? (c) Why does reflection not translate into effectiveness? and (d) How is effectiveness perceived in the professional, social school environment of novice teachers? Results of the case studies determined that teacher education programs must go …

An Analytical Approach To A Tree-Farm Wetland Study., Robert Cunninghame Davidge

LSU Historical Dissertations and Theses

Wetland delineation is important because federal and local government regulations limit permissible uses of wetlands. Federal delineation regulations are based upon the use of a manual jointly agreed upon by EPA, USACOE, and NRCS. The manual provides for classification of land as either wetland or non-wetland based upon the 3 criteria of soil, vegetation, and hydrology. No provision is made for gradation between categorical wetland and categorical non-wetland. Controversy has sometimes developed between landowners and environmentalists as to proper wetland classification; some delineations have been considered arbitrary. The analytical method of wetland appraisal provides a means of assigning continuous numerical …

Evaluation Of The Toxicological Consequences Of Dietary Exposure To Individual Classes Of Polycyclic Aromatic Hydrocarbons Or A Mixture In The Fischer-344 Rat., Mary Durand Boudreau

LSU Historical Dissertations and Theses

There is special concern about the potential health effects of by-products released into the environment after combustion or conversion of fossil fuels. Polycyclic aromatic hydrocarbons (PAH), while initially released largely into the atmosphere, are subsequently deposited in soil and water and on foods. Although the significance of PAH contamination with regard to environmentally caused diseases and cancer in humans is difficult to estimate, it is suggested that the potential hazards may be underestimated. In an effort to understand the potential adverse health effects of PAHs, a comprehensive study was undertaken to determine the metabolic fate of selected PAHs as individual …

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 …

Marginal Employment In The United States: 1971-1993., Nicole Thomson Flynn

LSU Historical Dissertations and Theses

In this dissertation, I examine trends in production and the concomitant demographic transformation of the labor force, in the context a series of economic cycles since 1969. Using these three forces as a backdrop, I first consider changes in employment hardship and the forces contributing to underemployment during periods following economic recessions. Then, I examine differences between men and women for employment outcomes. Next, to explain hardship during these periods, I include important demographic and geographic factors related to underemployment. Finally, I examine the impact of labor market context on individual outcomes. Based on the transformation of work, I explain …

The Optimal Implementation Of On-Line Optimization For Chemical And Refinery Processes., Xueyu Chen

LSU Historical Dissertations and Theses

On-line optimization is an effective approach for process operation and economic improvement and source reduction in chemical and refinery processes. On-line optimization involves three steps of work as: data validation, parameter estimation, and economic optimization. This research evaluated statistical algorithms for gross error detection, data reconciliation, and parameter estimation, and developed an open-form steady state process model for the Monsanto designed sulfuric acid process of IMC Agrico Company. The plant model was used to demonstrate improved economics and reduced emissions from on-line optimization and to test the methodology of on-line optimization. Also, a modified compensation strategy was proposed to improve …

Adjective Acquisition: Developmental Changes In The Use Of The Shape Bias, Syntax, Shape Consistency, And Semantic Attributes., Lenore Carol Frigo

LSU Historical Dissertations and Theses

When learning vocabulary, children must determine the meaning of each word that they hear. In hypothesizing about word meanings, children follow certain principles that simplify vocabulary acquisition. Among these principles are several that lead children to follow a shape bias. Under the shape bias, children assume that words extend to objects that share a common shape. This shape bias is useful for learning count nouns, which often include whole-object shape as an important aspect of meaning. However, the shape bias is not useful for the development of other word classes, such as adjectives. In this study, several variables were examined …

A Knowledge-Based System For Reliability-Centered Maintenance In The Chemical Industry., Daniel Jesus Fonseca

LSU Historical Dissertations and Theses

An innovative new framework for the implementation of reliability centered maintenance (RCM) in industrial settings was developed and implemented during this study. Fuzzy reasoning algorithms were designed to evaluate and assess the likelihood of equipment failure mode precipitation and aggravation. Furthermore, an alternative to the traditional RCM decision tree for prioritizing equipment failure modes was defined through the development of an approximate reasoning scheme. This priority scheme not only takes into account the relevancy of failure modes on local and product effects, but also their possibility of occurrence, as well as associated negative consequences on adjacent machinery. The new RCM …

Atmosphere Effects Revisited: The Effect Of Atmosphere On Judgments Of Validity Using Thematic Syllogisms., Roberta Elizabeth Love

LSU Historical Dissertations and Theses

Syllogisms having conclusions consistent with atmosphere are shown to be accepted at significantly higher rates than those having conclusions inconsistent with atmosphere. Furthermore, there is strong evidence that the dual influences of quality and quantity, independently affect acceptance rates. The first experiment also indicates a main effect of gender on acceptance rates to certain invalid syllogisms (those with conclusions inconsistent with quality, or quantity, or both). The second experiment replicates the atmosphere effect found in the first experiment and extends it to valid syllogisms and indeterminate invalids consistent with both quality and quantity. It also proposes an alternative to the …

Parallelization And Implementation Of Approximate Root Isolation For Nonlinear System By Monte Carlo., Ebrahim Khosravi

LSU Historical Dissertations and Theses

This dissertation solves a fundamental problem of isolating the real roots of nonlinear systems of equations by Monte-Carlo that were published by Bush Jones. This algorithm requires only function values and can be applied readily to complicated systems of transcendental functions. The implementation of this sequential algorithm provides scientists with the means to utilize function analysis in mathematics or other fields of science. The algorithm, however, is so computationally intensive that the system is limited to a very small set of variables, and this will make it unfeasible for large systems of equations. Also a computational technique was needed for …

A Universal Parametrization In B-Spline Curve And Surface Interpolation And Its Performance Evaluation., Choong-Gyoo Lim

LSU Historical Dissertations and Theses

The choice of a proper parametrization method is critical in curve and surface fitting using parametric B-splines. Conventional parametrization methods do not work well partly because they are based only on the geometric properties of given data points such as the distances between consecutive data points and the angles between consecutive line segments. The resulting interpolation curves don't look natural and they are often not affine invariant. The conventional parametrization methods don't work well for odd orders k. If a data point is altered, the effect is not limited locally at all with these methods. The localness property with respect …

Comparative Structure And Function Of Intrinsic Gill Muscles In Freshwater Bivalve Molluscs., Scott Medler

LSU Historical Dissertations and Theses

The lamellibranch gill is used for various vital functions ranging from food capture to ion regulation. The foundation for many of these functions is the transport of water through the gill. This dissertation examines the organization of intrinsic gill muscles and the associated connective tissue in the freshwater bivalve Dreissena polymorpha with comparisons made to Corbicula fluminea and Toxolasma texasensis. Gill muscles can be divided into two groups: those associated with the connective tissue sheets that underlie external and internal gill epithelia; and those encased in connective tissue bands oriented perpendicular to the bases of gill filaments. The sets of …