Digital Commons Network^™

Influence Of Pyrithiobac And Insecticide Combinations On Cotton Growth And Early Season Pest Control., Richard Whitman Costello

LSU Historical Dissertations and Theses

Field studies were conducted at two locations in Northeast Louisiana, to investigate interactions associated with the herbicide pyrithiobac and insecticide combinations in respect to weed control and insecticide efficacy and cotton response. In addition, controlled environment experiments were conducted to evaluate the effect of temperature regimes and simulated thrips damage on pyrithiobac plus insecticide phytotoxicity to cotton. Pyrithiobac and insecticide combinations when compared with pyrithiobac alone did not reduce cotton leaf area, height, main stem node number, main stem nodes to first square, days to first square or flower, main stem nodes above white flower, or seedcotton yield. Acephate insecticide …

Female High School Biology Students' Biofilm -Focused Learning: The Contributions Of Three Instructional Strategies To Patterns In Understanding And Motivation., Jo Dale Hill Ales

LSU Historical Dissertations and Theses

This exploratory study examined three instructional strategies used with female high school biology students. The relative contributions of the strategies to student understanding of microbiology and motivation in science were analyzed. The science education community targeted underachievement in science by implementing changes in content and practices (NRC, 1996). Research suggested that teachers facilitate learnirig environments based on human constructivism (Mintzes, Wandersee, & Novak, 1997) that is rooted in meaningful learning theory (Ausubel, Novak & Hanesian, 1978). Teachers were advised to use both visual and verbal instructional strategies (Paivio, 1983) and encourage students to construct understandings by connecting new experiences to …

Removal Of Manganese In Reservoir Tailwaters As A Function Of Reservoir Operations And River Substrate., Steven Lane Ashby

LSU Historical Dissertations and Theses

Removal of reduced manganese in aqueous systems has been described as a two-step process that incorporates a chemical or abiotic step followed by or continued with microbially mediated processes. Field and laboratory studies were conducted to describe the removal of manganese from reservoir tailwaters and partition the abiotic and microbial removal processes. Manganese removal was measured in controlled raceways and in microcosms with four sizes of substrate (cobble, 2.00 to 0.50 mm, 0.50 mm to 0.063 mm, and less than 0.063 mm). Sodium azide was used to inhibit biological uptake. An exponential decay model and a hyperbolic decay model were …

Intention To Leave Teaching: A Study Of Louisiana Elementary School Teachers Early In Their Careers., Karen Elizabeth Callender

LSU Historical Dissertations and Theses

The purpose of this study was to determine the relationship between the intention to leave teaching of teachers early in their careers and the variables: teacher self-efficacy, teacher age, school size, community type, socioeconomic background of student population, student discipline, and salary. Both quantitative and qualitative methods were employed to investigate these relationships. Survey data were collected from kindergarten through fifth grade teachers in Louisiana public schools, and interviews were conducted with those reporting the highest intention to leave. The quantitative data revealed school size to be significantly related to teacher intention to leave teaching, and teacher self-efficacy, student SES, …

Heritability Of Waterlogging Tolerance In Wheat., Agron Collaku

LSU Historical Dissertations and Theses

Waterlogging stress is one of the factors depressing wheat yield. Study of heritability for yield and yield components under waterlogging is important in determining the influence of genetic factors accounting for waterlogging tolerance as compared to environmental stress. The objectives of this study were: (1) to study the effect of waterlogging on yield and yield components of soft red winter wheat; (2) to estimate losses from waterlogging; (3) to estimate heritability of waterlogging tolerance in early generations of wheat for yield and yield components, and (4) to provide selection criteria for waterlogging tolerance in wheat breeding. Linear reduction in yield …

Modified Atmosphere Packaging Of Fresh -Cut Sweetpotatoes., Elif Erturk

LSU Historical Dissertations and Theses

Fresh-cut sweetpotato products have potential to create new value-added market opportunities. To determine optimum film packaging and storage temperature, fresh-cut sweetpotato slices were packaged with semipermeable polyolefin films, having different gas transmission characteristics and kept at 2 or 8°C for 14 days. The films chosen, in order of increasing permeability, were Cryovac PD900, PD961, and PD941. Among the films, only PD941 film bags maintained an aerobic atmosphere during the 14 days at both temperatures. However, the high weight loss in slices with PD941 film bags will limit the use of these film bags as modified atmosphere packaging (MAP) material. PD961 …

Development Of Novel Separation Strategies: Part I. The Separation And Characterization Of The Insecticidal Pyrethrin Esters. Part Ii. Separations In Capillary Electrochromatography., Charles William Henry Iii

LSU Historical Dissertations and Theses

The analytical investigation of the natural insecticide pyrethrum has been conducted. In this research, novel approaches were designed to yield either faster, or more complete separation of the active pesticidal esters in pyrethrum extracts as well as more complete conformational information of the structures of these compounds in solution. A combination of techniques was used: micellar electrokinetic chromatography (MEKC), nuclear magnetic resonance spectroscopy (NMR), and capillary electrochromatography (CEC). Using MEKC, an optimized separation of the six pyrethrin esters was achieved in 25 minutes with 25 mM Tris, buffered at pH 9, containing 30 mM SDS, 25% (v/v) acetonitrile, and an …

The Effects Of The Laboratory On College Students' Understanding Of Evolution: Implications For Conceptual Change., Lorna Benita Holtman

LSU Historical Dissertations and Theses

This study investigated eighty junior and senior college students' understanding of evolutionary biology concepts in lecture-only and lecture-laboratory settings. The evolution lab stressed the processes of evolution, and involved simulations, experiments, discussions, report writing, and reading. Test scores do not reveal everything about the actual process of learning in the laboratory. This study examined conceptual change patterns over a period of one semester using in-depth interviews with eight participants. The study revealed that the lecture-laboratory group performed better than the lecture-only group on certain shared items on the objective examination. The interview participants showed various patterns of conceptual change; that …

Synthesis Of Phosphonate And Thiophosphonate Peptide Analogs As Inhibitors Of Carboxypeptidase A., Hong Fan

LSU Historical Dissertations and Theses

Phosphonate analogs of peptides are important in biochemical research and potentially as medicinal agents because of their ability to strongly inhibit both metallo and aspartyl proteases. Although a number of phosphorus-containing molecules were reported as inhibitors for carboxypeptidase A (CPA, there have been only a few thiophosphonopeptide inhibitors reported. There has been no investigation in which the Ki values of a series of thiophosphonate inhibitors was compared to the analogous phosphonates to probe the role the sulfur atom in inhibition. The goal of this work is to prepare phosphonopeptide inhibitors of CPA and their thio-analogs so that this comparison can …

Immobilization Of Enzymes On Porous Silica For The Micro-Digestion Of Oligonucleotides With Analysis By Ce., Yolanda Yvette Davidson

LSU Historical Dissertations and Theses

The research in this dissertation has focused on the immobilization of enzymes on silica to perform digestions with DNA and RNA with subsequent analysis by capillary electrophoresis. Solid-phase DNA restriction digest reactors were developed consisting of silica particles modified with a covalently tethered restriction enzyme. This solid-phase restriction reactor enables digestion and separation of minute quantities of DNA with minimal reagent consumption. The restriction enzymes, HaeIII, PstI and HindIII, were successfully immobilized via glutaraldehyde linkages to porous silica micro-particles. Studies were done to examine the impact of immobilization on enzymatic activity. Digestions of &phis;X174-RF DNA phage and SV40 Viral DNA …

Interaction Of Antimicrobial Peptides With Model Cell Membranes., Lucille Dionne Smith Wright

LSU Historical Dissertations and Theses

This research was part of a multidisciplinary effort aimed at the elucidation of the mechanism of membrane lysis by model peptides. The focus of the dissertation was to characterize the average size dimensions of model cell membranes before and after being treated by model peptides. Experiments with neutral dioleoylphosphatidylcholine (DOPC) vesicles and negatively charged dioleoylphosphabdylcholine/dioleoylphosphabdylglycerol (DOPC/DOPG) vesicles were conducted using the model peptides (KLAKKLA) 3 and (KLGKKLG)3. A melittin study was conducted alongside for comparison. Changes in membrane integrity were studied as a function of lipid-to-peptide (L:P) ratio using three techniques: kinetic light scattering (KLS), dynamic light scattering (DLS), and …

Evaluation Of Insecticide Resistance In Louisiana Adult Mosquitoes And The Efficacies Of Selected Larvicides., Stacy Lee Bearden

LSU Historical Dissertations and Theses

Pesticide resistance in Louisiana mosquitoes has never been examined on a state-wide basis. In 1996, first component of this monitoring program examined selected pesticide efficacies and documented current pesticide resistance. Ground ULV-applied FyfanonRTM (96.8% malathion and Pyrocide RTM (96.8% + 1% natural pyrethrum) were applied to caged Culex quinquefasciatus adults (Denham Springs [Livingston Parish] and Lake Charles [Calcasieu Parish]) and Aedes sollicitans (Vermilion Parish). FyfanonRTM caused significantly different (p < 0.05) mortalities among each species and strain within 24hrs (95% Aedes, 48% Denham Springs, and 14% Lake Charles). Pyrocide RTM also produced significantly different mortalities (99%, 70%, and 38%, respectively). Malathion and permethrin were topically applied to 3--5 day old adult mosquitoes from 14 parishes. St. Martin parish Cx. quinquefasciatus was most susceptible to malathion (2.58 mug/mul), and the Vermilion strain was most resistant (417.05 mug/mul). Resistance is based on a ≥5-fold resistance ratio. Calcasieu parish strain was least resistant to permethrin (1.93 mug/mul), and the St. Tammany parish strain was most resistant (40.86 mug/mul). Detecting pesticide resistance by bottle bioassay technique was compared to topical bioassay. Both techniques were effective in detecting resistance for selected Aedes, Anopheles, and Culex species in Louisiana. Ground ULV 97% malathion was applied to caged Cx. quinquefasciatus adults from a mosquito abatement district, agrichemical farmland, and a susceptible colony. No significance (p > 0.05) existed in mosquito mortality between the agrichemical area and the abatement district. Bacillus thuringiensis var. israeliensis (VectoBacRTM WDG and VectoBacRTM 12AS) and Bacillus sphaericus (VectoLexRTM WDG and VectoLexRTM CG) were …

Systematics Of The Polymorphic North American Rat Snake (Elaphe Obsoleta)., Frank Thomas Burbrink

LSU Historical Dissertations and Theses

The North American rat snake (Elaphe obsoleta) complex is composed of seven uniquely colored subspecies of E. obsoleta and the sister species E. bairdi. Maximum parsimony (MP) and maximum likelihood (ML) analysis of two mitochondrial DNA genes from 73 E. obsoleta and E. bairdi, produced well-supported trees that do not conform to the currently accepted subspecies. Both ML and MP trees were significantly shorter than the trees in which each subspecies was constrained to be monophyletic. The subspecies of E. obsoleta do not represent genetic lineages. Instead, molecular evidence revealed the existence of four well-supported mtDNA clades confined to particular …

Comparative Biology And Ecology Of The Formosan Subterranean Termite, Coptotermes Formosanus Shiraki (Isoptera: Rhinotermitidae) In Louisiana., Huixin Fei

LSU Historical Dissertations and Theses

A laboratory study was conducted to investigate the effects of sibship patterns and different origins of colonies on mate mortality and growth of incipient colonies in the subterranean termite, Coptotermes formosanus Shiraki. Primary reproductives from New Orleans in nonsibling pairs had significantly higher mortality than sibling pairs. The average egg production for sibling and nonsibling pairs showed no overall significance in the first oviposition period, however, the average number of larvae was consistently higher in nonsibling than in sibling-founded colonies from New Orleans. After two years, the average number of eggs or larvae present in nonsibling-founded colonies was significantly higher …

Activation And Metabolism Of P-Nitrosophenoland 2,2'-Thiobis-Ethanol By Horse Liver And Human Alcohol Dehydrogenase: Toxicological Implications., Billy Fred Dudley Jr

LSU Historical Dissertations and Theses

C-nitroso compounds are reactive intermediates in the toxic sequelae of nitroarene metabolism. Alcohol dehydrogenase (ADH) contributes significantly to NADH-dependent C-nitroso reduction by cytosol relative to NAD(P)H: quinone oxidoreductase (NQOR). NADPH-dependent pNSP reduction by liver cytosol of ADH+ animals is mostly dicumarol-sensitive which implicates NQOR as the major NADPH-dependent activity. Although, extensive structural homology between horse and different isozymes of human ADH exist, significant differences occur within the active site, which account for great variability among substrate specificities, kinetic constants, and response to inhibitors. We have studied the metabolic activity of horse liver alcohol dehydrogenase (HLADH), purified class I alphaalpha, beta …

Comparison Of Biogeochemical Functions Between Restored And Natural Bottomland Hardwood Wetlands., Rachael Grimsley Hunter

LSU Historical Dissertations and Theses

The purpose of this research was to compare biogeochemical functions of restored and natural bottomland hardwood (BLH) wetlands to determine if re-establishment of hydrology and vegetation is equivalent to restoration of ecosystem function. Three wetland types were studied: natural BLH (NAT), restored with hydrology re-established (RWH), and restored without hydrology re-established (RWOH). Denitrification potential (DEA), soluble organic carbon (SOC), soil moisture, readily mineralizable carbon (RMC), and heterotrophic microbial activity were measured seasonally from 1997--99. Leaf litter mass, total carbon and nitrogen concentrations, moisture, and microbial activity were also measured at three soil depths in study wetlands. The effect of organic …

A Method To Discriminate Species From Hydroacoustic Fish Sampling Systems., Rui De Paula E Silva

LSU Historical Dissertations and Theses

Samples of species and size composition obtained by trawling were matched with the corresponding echo-distributions from two hydroacoustic and trawl surveys in the western Indian Ocean, off Mozambique, and in two surveys in the northern Gulf of Mexico. In the Mozambique surveys, a Simrad EY-M echosounder was used and the data was analyzed by applying the Craig & Forbes algorithm. In the Gulf of Mexico surveys, a BioSonics Dual-beam System (Model 102 echosounder, ESP echo-integrator, and ESP dual-beam processor) was used. The results obtained show that, provided that a particular hydroacoustic and trawl sample yielded a stable size-distribution of the …

Effects Of Microstructure And Crystallographic Texture On Yield Behavior Of Aluminum-Copper-Lithium 2195 Plate., Karen Elizabeth Crosby

LSU Historical Dissertations and Theses

The focus of this research is to study the effects of deformation and aging on the yield behavior of precipitation-hardened Al-Cu-Li alloys, specifically AI-Cu-Li 2195 plate. Al-Cu-Li 2195 is a relatively new and exceptionally strong, yet lightweight aluminum alloy. Experimental methods applicable to mechanical/structural engineering and materials science problems provide the means for understanding the interrelation of deformation, microstructure, and crystal orientation (texture) as they affect the mechanical properties of crystalline materials. Yield strength is a vital mechanical property in that it defines the boundary of stress that may be applied to a part before a permanent, in some cases, …

The Effects Of Equine Somatotropin (Est) On Reproductive Function In The Domestic Mare., Richard Anthony Cochran

LSU Historical Dissertations and Theses

The effects of somatotropin on ovarian reproductive function has become a keen research area in mammalian species over the past decade. However, to date, very little information is available as to the effects of somatotropin administration on reproduction in the domestic mare. Therefore, the purpose of these experiments was (1) to determine the potential effects (if any) of administration of exogenous equine somatotropin on ovarian follicular development and plasma and follicular fluid hormone concentrations in cyclic and noncyclic mares, (2) to determine the mechanism(s) of action of somatotropin treatment on these parameters in the mare, (3) to develop an efficient …

Effect Of Smoking On The Body Mass Index-Mortality Relation: Empirical Evidence From 15 Studies, V. Hawthorne, V. Hawthorne, D. Kozarevic, N. Vojvodic, C. R. Gillis, D. Hole, C. Hart, T. Jorgensen, T. Thomsen, M. Davidson, U. Goldbourt, S. Yaari, G. Cao, R. Cooper, R. Durazo-Arvizu, Z. Li, Y. Liao, D. Mcgee, T. E. Prewitt, C. Sempos

Faculty Publications

The authors examined the impact of smoking status on the relation between body mass index (weight (kg)/height (m)2) and mortality across a group of 15 diverse observational studies. The studies included a heterogeneous sample of national samples, cohort studies with mortality follow-up, and clinical trials. Consideration of the data according to natural strata resulted in the formation of 42 analytic cohorts. The authors examined survival through the end of follow-up for each study, as influenced by body mass index, age, and current smoking status at baseline, using a proportional hazards model to describe the relation between body mass index and …

Maximizing Economic Returns From Sugarcane Production Through Optimization Of Harvest Schedule (Bulletin #868), Michael E. Salassi, Lonnie P. Champagne, Benjamin L. Legendre

LSU AgCenter Bulletins

This bulletin presents a methodology for the incorporation of within-season sucrose accumulation in sugarcane into an optimal single-season, daily harvest scheduling model at the individual farm level.

Regulation Of Signal Transducers And Activators Of Transcription (Stats) By Effectors Of Adipogenesis: Coordinate Regulation Of Stats 1, 5a, And 5b With Peroxisome Proliferator-Activated Receptor-Γ And C/Aaat Enhancer Binding Protein-Α, William C. Stewart, Ron F. Morrison, Sherry L. Young, Jacqueline M. Stephens

Faculty Publications

We have recently demonstrated that three signal transducers and activators of transcription (STAT) family members are induced during adipocyte differentiation (Stephens et al., J. Biol. Chem. 271 (1996) 10441- 10444). Since STATs 1, 5A, and 5B are induced during adipocyte differentiation, we have examined the ability of these proteins to be regulated by components of the differentiation cocktail. In addition, we have examined the effects of potent effectors of differentiation on STAT protein expression during adipogenesis. A negative effector, tumor necrosis factor-α (TNFα), and a positive effector, a thiazolidinedione, were used in these experiments. Our results demonstrate that the expression …

Regulation Of The Dolichol Pathway In Human Fibroblasts By The Endoplasmic Reticulum Unfolded Protein Response, William T. Doerrler, Mark A. Lehrman

Faculty Publications

Accumulation of unfolded proteins within the endoplasmic reticulum (ER) of eukaryotic cells triggers the unfolded protein response (UPR), which activates transcription of several genes encoding ER chaperones and folding enzymes. This study reports that conversion of dolichol-linked Man2-5GIcNAc2 intermediates into mature Glc3Man9GlcNAc2 oligosaccharides in primary human adult dermal fibroblasts is also stimulated by the UPR. This stimulation was not evident in several immortal cell lines and did not require a cytoplasmic stress response. Inhibition of dolichol-linked Glc3Man9GlcNAc2 synthesis by glucose deprivation could be counteracted by the UPR, improving the transfer of Glc3Man9GlcNAc2 to asparagine residues on nascent polypeptides. Glycosidic processing …

Biogeochemical Transformations And Potential Polyaromatic Hydrocarbon Degradation In Macrofaunal Burrow Sediments, W. K. Chung, Gary M. King

Faculty Publications

A variety of polyaromatic hydrocarbons (PAH) including naphthalene, phenanthrene, acenaphthene, and dibenzothiophene were degraded with little or no lag in oxic slurries of marine sediments from burrow walls constructed by benthic macrofauna. PAH degradation potentials of burrow sediments from the polychaetes Nereis virens and Clymenella torquata, the mollusc Mya arenaria and the enteropneust Saccoglossus bromophenolosus were generally greater than potentials for non-burrow sediments; relative rates of degradation varied among the burrow wall sediments depending on the PAH assayed. Comparisons of the effects of available electron acceptors (oxygen, nitrate, ferric iron, sulfate) indicated that significant degradation of benzene, hexadecane and PAH …

Synthesis And Unusual Properties Of The First 2,3,7,8,12,13,17,18-Octabromo-5,10,15,20-Tetraalkylporphyrin, Nora Y. Nelson, Craig J. Medforth, Daniel J. Nurco, Song Ling Jia, John A. Shelnutt, Kevin M. Smith

Faculty Publications

The new perhalogenated porphyrin 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(trifluoromethyl)porphinato -nickel(II) exhibits several striking features, including an extremely ruffled macrocycle with a very short Ni-N distance, an unusually red-shifted optical spectrum, and, surprisingly, hindered rotation of the meso-trifluoromethyl substituents (ΔG2+78 = 47 kJ mol-1).

F99rs Sgb No. 8 (Bio Engr Design), Cancienne

Student Senate Enrolled Legislation

A BILL

To appropriate one thousand dollars ($1,000.00) to the LSU Department of Biological Engineering Senior Design Project Team to help defray the cost of purchasing hardware and chemicals to be used in the fabrication and testing of a prototype for a student-designed fluoride removal water treatment system that will then be installed in an underpriveleged community in Bananera, Guatemala.

Louisiana Agriculture Fall, 1999, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Seeking Causal Explanations In Social Epidemiology, Jay S. Kaufman, Richard S. Cooper

Faculty Publications

Social factors are associated with a wide variety of health outcomes. Social epidemiology has successfully used the traditional methods of surveillance and description to establish consistent relations between social factors and health status. Epidemiology as an etiologic science, however, has been largely ineffective in moving toward causal explanations for these observed patterns. Using the counterfactual approach to causal inference, the authors describe several fundamental problems that often arise when researchers seek to infer explanatory mechanisms from data on social factors. Contrasts that form standard causal effect estimates require implicit unobserved (counterfactual) quantities, because observational data provide only one exposure state …

The Impact Of Accelerating Land-Use Change On The N-Cycle Of Tropical Aquatic Ecosystems: Current Conditions And Projected Changes, J. A. Downing, M. Mcclain, R. Twilley, J. M. Melack, J. Elser, Nancy N. Rabalais, W. M. Lewis Jr., R. Eugene Turner, J. Corredor, D. Soto, A. Yanez Arancibia, J. A. Kopaska, R. W. Howarth

Faculty Publications

Published data and analyses from temperate and tropical aquatic systems are used to summarize knowledge about the potential impact of land-use alteration on the nitrogen biogeochemistry of tropical aquatic ecosystems, identify important patterns and recommend key needs for research. The tropical N-cycle is traced from pre-disturbance conditions through the phases of disturbance, highlighting major differences between tropical and temperate systems that might influence development strategies in the tropics. Analyses suggest that tropical freshwaters are more frequently N-limited than temperate zones, while tropical marine systems may show more frequent P limitation. These analyses indicate that disturbances to pristine tropical lands will …

Black-White Differences In Disability And Morbidity In The Last Years Of Life, Youlian Liao, Daniel L. Mcgee, Guichan Cao, Richard S. Cooper

Faculty Publications

To assess black-white differences in disability and morbidity in the last years of life, the authors analyzed data from the National Health Interview Survey from 1986 to 1994, with mortality follow-up through December 1995. A baseline household interview was conducted for 10,187 decedents aged 50 years and over within 2 years before death. Data collected included long- term limitation of activity, number of chronic conditions, number of bed days, doctor visits, and days of short hospital stay during the year preceding the interview. For both blacks and whites, educational attainment was inversely associated with disability/morbidity indices. Black decedents had greater …