The Impact Of Co2-Related Ocean Acidification On The Molecular Regulation Of Shell Development In The Eastern Oyster (Crassostrea Virginica)., Mackenzie L. Richards

LSU Master's Theses

Eastern oysters (Crassostrea virginica), native to the Gulf of Mexico, are keystone species in estuarine ecosystems and are economically valued. Current research indicates that ocean acidification adversely affects the physiology and morphology of larval oysters, but the molecular mechanisms of this impact remain unstudied. Ocean acidification is contributed to by elevated atmospheric CO₂ due to increased anthropogenic activities, causing heightened partial pressure of CO₂ (pCO₂), and eutrophication from land-based runoff in the Gulf. The objective of this work was to determine the genomic response of the eastern oyster in Louisiana to simulated ocean acidification. …

Incorporation Of Biorationals And Trap Crop For Stink Bug Management In Soybeans, Kukuh Hernowo

LSU Doctoral Dissertations

Stink bugs are one of the most important seed sucking pests impacting soybean production in Louisiana. Exploration of chemicals that exhibit attraction or repellent activities toward this major pest would be beneficial to develop a push-pull strategy against this pest complex. Spinosad and neem are two commercially available natural insecticides that were claimed to have attractant and repellent activities against stink bugs. To test the potential of these chemicals, a series of experiments was conducted to investigate the olfactory, tactile, feeding, and oviposition preference of stink bugs toward different commercial spinosad products and neem. Additionally, two years of field experiments …

Characterization Of Aspergillus Flavus Soil And Corn Kernel Populations From Eight Mississippi River States, Jorge A. Reyes Pineda

LSU Master's Theses

Aspergillus flavus is a saprophytic ascomycete that can also actively invade the seed of crops and potentially contaminate them with harmful aflatoxins. Management of A. flavus currently relies mostly on biocontrol. However, there is still a lot to learn about its biology and ecology so the current approach can be improved. An A. flavus population survey was undertaken during the fall of 2014 across eight Mississippi River states to determine population diversity and geographic distribution of VCGs. Isolates from corn and soil were also characterized for VCG, sclerotial morphotype, mating type, cyclopiazonic acid, and aflatoxin production in order to determine …

Sweetpotato Virus C And Its Contribution To The Potyvirus Complex In Sweetpotato (Ipomoea Batatas), Favio E. Herrera Eguez

LSU Doctoral Dissertations

In Louisiana, sweetpotato (Ipomoea batatas) is infected in Louisiana by the four ubiquitous potyviruses: Sweetpotato feathery mottle virus (SPFMV), Sweetpotato virus G (SPVG), Sweetpotato virus 2 (SPV2) and the strain of SPFMV previously known as the common strain, recently renamed as Sweetpotato virus C (SPVC). These four viruses belong to the Potyviridae family, with single stranded RNA of ~11kb. In this group of plant viruses, a single polyprotein is coded entirely but later cleaved into ten mature proteins: P1, HC-pro, P3, 6K1, CI, 6K2, NIa-VPg, NIa-Pro Nib and Coat Protein (CP). In sweetpotato potyviruses, two additional open reading …

Alteration Of Gut Microbiota And Other Properties In Zucker Diabetic Fatty Rats After Antibiotics, Diet And Donor Transplant, Ryan Page

LSU Master's Theses

The compositions of bacterial communities inhabiting the human gut are associated with regulating energy balance, immune response, and neurological functions. Many of these benefits are attributed to byproducts of bacteria that feed on fermentable fibers. Research has shown that obese or lean host can transfer their phenotype to germ-free recipients, via microbiota transplant, without alteration in recipient diet. However, transfer may be attenuated by established microbial communities in conventionally-raised rodents or other species. A knockdown of recipient communities may be required before a transplant for microbiota of donors to populate gut of recipient. This study examined whether obese Zucker Diabetic …

Integrating The Effects Of Salinity On The Physiology Of The Eastern Oyster, Crassostrea Virginica, In The Northern Gulf Of Mexico Through A Dynamic Energy Budget Model, Romain Lavaud, Megan K. La Peyre, Sandra M. Casas, Cédric Bacher, Jérôme F. La Peyre

Faculty Publications

© 2017 We present a Dynamic Energy Budget (DEB) model for the eastern oyster, Crassostrea virginica, which enables the inclusion of salinity as a third environmental variable, on top of the standard foodr and temperature variables. Salinity changes have various effects on the physiology of oysters, potentially altering filtration and respiration rates, and ultimately impacting growth, reproduction and mortality. We tested different hypotheses as to how to include these effects in a DEB model for C. virginica. Specifically, we tested two potential mechanisms to explain changes in oyster shell growth (cm), tissue dry weight (g) and gonad dry weight (g) …

Teachers' Experience Of A Flood In Their School Community: Their Beliefs, Perceptions, And Thoughts About Practice, Caroline Tolentino

LSU Master's Theses

The increasing number of flooding incidences in Louisiana exposes a significant number of children to the possible traumatic effects of this natural disaster. Flooding takes a toll not only on families and children, but on teachers as well. While the effects of other types of disasters on children have been considered in previous studies, research has not thoroughly addressed the effects of flooding on children and on early childhood teachers. Teachers can be very instrumental in helping young children cope and making sure their needs are met after the experience of a traumatic event (Perry & Szalavitz, 2008; Le Brocque, …

Issues Related To Carbon Dioxide Pipeline Transportation Infrastructure In Louisiana, Michael Allen Layne Iii

LSU Master's Theses

There is no single solution to mitigate anthropogenic climate change; a multifaceted approach with economic incentives is needed. Carbon dioxide (CO₂) enhanced oil recovery (EOR) is one such solution which provides an economic incentive, in the capture and sale of oil, for sequestering CO₂ underground. While carbon capture and subsequent geological injection are both mature technologies, there has been little discussion or appreciation for the role of pipelines. The current CO₂ pipeline infrastructure will need to significantly expand in order to accommodate increasing EOR production. However, pipeline construction costs, and institutional factors impacting development, may be …

A Role For The Cystic Fibrosis Transmembrane Conductance Regulator In The Nitric Oxide-Dependent Release Of Cl – From Acidic Organelles In Amacrine Cells, Vijai Krishnan, J. Wesley Maddox, Tyler Rodriguez, Evanna Gleason

Faculty Publications

© 2017 the American Physiological Society. γ-Amino butyric acid (GABA) and glycine typically mediate synaptic inhibition because their ligandgated ion channels support the influx of Cl – . However, the electrochemical gradient for Cl – across the postsynaptic plasma membrane determines the voltage response of the postsynaptic cell. Typically, low cytosolic Cl – levels support inhibition, whereas higher levels of cytosolic Cl – can suppress inhibition or promote depolarization. We previously reported that nitric oxide (NO) releases Cl – from acidic organelles and transiently elevates cytosolic Cl – , making the response to GABA and glycine excitatory. In this study, …

The Role Of Histone H2a.Z Abundance In Modulating Responses To Phosphorus Deficiency In Rice, Sara Zahraeifard

LSU Doctoral Dissertations

Histone variants contribute to chromatin complexity by creating specialized nucleosomes. Here, to investigate the pattern of H2A.Z histone variant distribution and its role in modulating gene expression in rice (Oryza sativa L.), we performed genome-wide profiling of ARP6-dependent H2A.Z deposition in rice seedlings. We demonstrated that under controlled conditions, the majority of H2A.Z deposition is within protein-coding genes (PCG), and the most highly expressed genes are enriched with H2A.Z at their 5’ ends near the transcription start site (TSS), whereas the medium- to low-expressed genes contain H2A.Z across the entire gene. Based on H2A.Z deposition, we categorized genes into …

Effect Of Hot Water Conditioning On Microbial Safety And Quality Of In-Shell Pecans, Karuna Kharel

LSU Master's Theses

Hot water conditioning of in-shell pecans is one common practice followed by industries to facilitate shelling. It also acts as a preventive control for potential microbiological contamination that might occur during pre- and post-harvest processes. However, heat treatment may have an effect on the eating quality of nuts. The main objectives of the study were to develop a post-harvest hot water treatment intervention as a kill step to destroy foodborne pathogens on in-shell pecans and evaluate the effect of treatments on physicochemical properties, consumer acceptance and purchase intent of dehulled and roasted pecans. The time (1-5 min) and temperature (70, …

Biased Genetic Screen Identifies Novel Genes Involved In Antiviral Defense, Tianyun Long

LSU Doctoral Dissertations

ABSTRACT

RNA interference (RNAi) mediates potent antiviral response across kingdoms. In Caenorhabditis elegans nematodes, antiviral RNAi requires a virus sensor that is conserved in mammals and is amplified by secondary small interfering RNAs that are produced in a Dicer-independent manner.

To better understand worm antiviral RNAi, I carried out a biased genetic screen, aiming to identify novel antiviral RNAi genes. To speed up the gene discovery process, the reporter worms used for this genetic screen were engineered to contain extra copies of 4 known antiviral RNAi genes. Therefore, genetic alleles derived from these 4 genes will be automatically rejected during …

The Characterization Of Alpha-Carbonic Anhydrases Through Mutagenesis And Subcellular Localization In Arabidopsis Thaliana, Lance E. Pounds

LSU Master's Theses

Carbonic anhydrases (CAs) are zinc metalloenzymes which catalyze the interconversion of carbon dioxide and bicarbonate. It is hypothesized that CA activity facilitates CO₂ flux in leaf mesophyll cells to maintain optimal rates of photosynthesis or to maintain a pool of inorganic carbon for other metabolic processes. There are three classes of CAs (α, β, and γ) in the model plant Arabidopsis thaliana. The βCAs and γCAs have been well studied, but the αCAs have received relatively little study. There are eight αCA genes in Arabidopsis. This study investigates which αCAs are expressed in shoots, their tissue-specific expression, their …

Development Of A Mode And Destination Type Joint Choice Model For Hurricane Evacuation, Ruijie Bian

LSU Doctoral Dissertations

Since Hurricane Katrina, transit evacuation service has been seen to serve critical needs in affected cities and an increasing number of hurricanes have struck the east coast where more people rely on public transportation to evacuate. Thus, it is important to model mode choice in evacuation for a better estimation of evacuation transit demand. In this study, a joint mode and destination type choice model was estimated based on multiple post-storm behavioral surveys from the northeastern seaboard to the Gulf coast. A Nested Logit model specification was used to estimate this joint choice model. The estimated model showed significant linkage …

Examining Limestone Use At Byrd Hammock South (8wa30), Wakulla County, Fl, Lucie R. Berryhill

LSU Master's Theses

In this thesis, I examine the limestone deposits identified at Byrd Hammock South during the Summer 2015 excavations conducted by Louisiana State University (LSU) and Florida State University (FSU). The site under investigation is the Byrd Hammock site (8WA30) in Wakulla County, Florida. Byrd Hammock is a multi-component site located only four miles north of the Gulf Coast and is close to other Swift Creek sites including Block-Sterns (8LE484) and Harrison Ring (8BY1359) (Russo, Hadden, and Dengel 2009). Like several other sites or site complexes on the Florida panhandle, Byrd Hammock has two large burial mounds that were placed on …

Virulence Phenotypes Of Rotylenchulus Reniformis: Evaluation Of Host Status Of Cotton And Utility Of Single Nucleotide Polymorphisms (Snps) For Identification, Churamani Khanal

LSU Doctoral Dissertations

Comparative reproduction and pathogenicity of reniform nematode (Rotylenchulus reniformis) populations derived from single-egg masses and collected form West Carroll (WC), Rapides (RAP), Morehouse (MOR), and Tensas (TEN) parishes in Louisiana were evaluated in microplot and greenhouse trials. Data from microplot trials showed significant differences among isolates of reniform nematode in both reproduction and pathogenicity on upland cotton (Gossypium hirsutum) cultivars Phytogen 499 WRF, Deltapine 1133 B2RF, and Phytogen 333 WRF. Across all cotton cultivars, MOR and RAP isolates had the greatest and the least reproduction values of 331.8 and 230.2, respectively. Reduction in plant dry weight, …

Pathogenicity And Reproduction Of Isolates Of Reniform Nematode, Rotylenchulus Reniformis, From Louisiana On Soybean And Utility Of Single Nucleotide Polymorphisms To Evaluate Genetic Variability, Herath Mudiyanselage Kularathna

LSU Doctoral Dissertations

Experiments were conducted to evaluate soybean, Glycine max (L.) Merr., responses to indigenous isolates of the reniform nematode (Rotylenchulus reniformis) in Louisiana and to understand the genetic variability of these native isolates. Microplot and greenhouse experiments were conducted to evaluate the comparative reproduction and pathogenicity of single egg-mass populations of R. reniformis isolated from West Carroll (WC), Rapides, Tensas and Morehouse (MOR) parishes of Louisiana. Data from full-season microplot trials, displayed significant differences in reproduction and pathogenicity of the nematode with the commercial soybean cultivars REV 56R63, Pioneer P54T94R, and Dyna-Gro 39RY57. Significantly low population density was observed …

Heat, Acid And Osmotic Stress Tolerance Of Leuconostoc Mesenteroides As Influenced By Prior Exposure To Various Mild Stress Conditions, Ingrid C. Osorio Rodriguez

LSU Master's Theses

The importance of Leuconostoc mesenteroides is recognized for its contribution to taste in cultured dairy products. It has been cited for its potential role as a probiotic. Consumer demand exists for new dairy products with health benefits. In the manufacture of probiotic-products survival of Leuconostoc mesenteroides would depend on its ability to tolerate challenging processing and storage conditions. Improved viability by prior exposure to mild stresses can increase stress tolerance toward a more severe stress. Furthermore, it can result in cross-protection due to connection of several proteins in response to stresses. Objective was to evaluate the effect of prior …

Human-Environment Interactions: Sea-Level Rise And Marine Resource Use At Eleanor Betty, An Underwater Maya Salt Work, Belize, Valerie Renae Feathers

LSU Doctoral Dissertations

Dissertation excavations were performed in the spring of 2013 at the underwater site of Eleanor Betty in Paynes Creek National Park, Belize. The marine environment preserved wooden architecture associated with the salt works. Excavation goals included: 1) excavating and defining the boundaries of the submerged shell midden; 2) collecting sediment samples for paleoenvironmental analyses; and 3) recovering cultural remains to determine the site’s purpose (residence versus production workshop).

Four transects were added to the existing transect from excavations performed during the 2011 field season. The shell midden measured 5 meters in length (north-to-south throughout all transects) by 0.5-to-1 meters in …

Evaluation Of Winter Management Methods To Enhance Survival Of The Giant Salvinia Weevil, Cyrtobagous Salviniae, Lori Robyn Moshman

LSU Master's Theses

Giant salvinia (Salvinia molesta Mitchell) is a noxious aquatic weed in the southeastern United States. Dense plant mats create ecological and economic consequences by displacing native species and impacting freshwater industries. Biological control programs using the salvinia weevil (Cyrtobagous salviniae Calder and Sands, Coleoptera: Curculionidae) have limited efficacy in giant salvinia’s northernmost range due to the weevil’s low cold tolerance and long-term establishment rates. Spunbonded polypropylene (SBP) fabrics and manipulation of plant density were evaluated as two strategies for managing giant salvinia mats during winter. Greenhouse, laboratory, and field experiments were conducted to determine the suitability of these …

Transcription-Driven Dna Methylation Setting On The Mouse Peg3 Locus, Corey L. Bretz, Joomyeong Kim

Faculty Publications

© 2017 Taylor & Francis Group, LLC. The imprinting of the mouse Peg3 domain is controlled through the Peg3-DMR, which obtains its maternal-specific DNA methylation during oogenesis. In the current study, we deleted an oocyte-specific alternative promoter, termed U1, which is localized 20 kb upstream of the Peg3-DMR. Deletion of this alternative promoter resulted in complete removal of the maternal-specific DNA methylation on the Peg3-DMR. Consequently, the imprinted genes in the Peg3 domain become biallelic in the mutants with maternal transmission of the deletion. Expression levels of the imprinted genes were also affected in the mutants: 2-fold upregulation of Peg3 …

Cysteines And N-Glycosylation Sites Conserved Among All Alphaherpesviruses Regulate Membrane Fusion In Herpes Simplex Virus 1 Infection, Paul J.F. Rider, Misagh Naderi, Scott Bergeron, Vladimir N. Chouljenko, Michal Brylinski, Konstantin G. Kousoulas

Faculty Publications

© 2017 American Society for Microbiology. Neurotropism is a defining characteristic of alphaherpesvirus pathogenicity. Glycoprotein K (gK) is a conserved virion glycoprotein of all alphaherpesviruses that is not found in other herpesvirus subfamilies. The extracellular amino terminus of gK has been shown to be important to the ability of the prototypic alphaherpesvirus herpes simplex virus 1 (HSV-1) to enter neurons via axonal termini. Here, we determined the role of the two conserved N-linked glycosylation (N48 and N58) sites of gK in virus-induced cell fusion and replication. We found that N-linked glycosylation is important to the regulation of HSV-1-induced membrane fusion …

Habitat Association Predicts Genetic Diversity And Population Divergence In Amazonian Birds, Michael G. Harvey, Alexandre Aleixo, Camila C. Ribas, Robb T. Brumfield

Faculty Publications

© 2017 by The University of Chicago. The ecological traits of organisms may predict their genetic diversity and population genetic structure and mediate the action of evolutionary processes important for speciation and adaptation. Making these ecological-evolutionary links is difficult because it requires comparable genetic estimates from many species with differing ecologies. In Amazonian birds, habitat association is an important component of ecological diversity. Here, we examine the link between habitat association and genetic parameters using 20 pairs of closely related Amazonian bird species in which one member of the pair occurs primarily in forest edge and floodplains and the other …

Cysteines And N-Glycosylation Sites Conserved Among All Alphaherpesviruses Regulate Membrane Fusion In Herpes Simplex Virus 1 Infection, Paul J.F. Rider, Misagh Naderi, Scott Bergeron, Vladimir N. Chouljenko, Michal Brylinski, Konstantin G. Kousoulas

Faculty Publications

© 2017 American Society for Microbiology. Neurotropism is a defining characteristic of alphaherpesvirus pathogenicity. Glycoprotein K (gK) is a conserved virion glycoprotein of all alphaherpesviruses that is not found in other herpesvirus subfamilies. The extracellular amino terminus of gK has been shown to be important to the ability of the prototypic alphaherpesvirus herpes simplex virus 1 (HSV-1) to enter neurons via axonal termini. Here, we determined the role of the two conserved N-linked glycosylation (N48 and N58) sites of gK in virus-induced cell fusion and replication. We found that N-linked glycosylation is important to the regulation of HSV-1-induced membrane fusion …

Internode Morphometrics And Allometry Of Tonkin Cane Pseudosasa Amabilis, Liang Cheng, Cang Hui, Gadi V.P. Reddy, Yu Long Ding, Pei Jian Shi

Faculty Publications

Pseudosasa amabilis (McClure) (Poales: Gramineae) is a typical bamboo species naturally distributed in large area of south China and famous for its culm strength. Although bamboos were found to share the same development rule, the detailed internode morphology of bamboo culm was actually not fully expressed. We explored internode morphology of P. amabilis using 11 different physical parameters in different dimensions (1–4). As Taylor's power law (TPL) is generally applicable to describe relationship between mean and variance of population density, here we used TPL to evaluate the differences between internodes, and further, the relationship between dimension and TPL. Results showed …

Arthropod Development’S Response To Temperature: A Review And New Software For Modeling, Mohammad Ali Mirhosseini, Yaghoub Fathipour, Gadi V.P. Reddy

Faculty Publications

Among environmental factors, temperature has a direct and crucial influence on the key life processes of survival, development, reproduction, and movement of poikilothermic animals and hence their population dynamics. The lower and upper temperature thresholds and optimal temperature have ramifications for all major life processes, where within a specific range, a temperature change results in a proportional rise or fall of the rate of any given process. There are some basic approaches for modeling development response to temperature in arthropods. The oldest and most widely used model is a simple linear description of arthropod development in relation to temperature.The linear …

Comparison Of Thermal Performance Equations In Describing Temperature-Dependent Developmental Rates Of Insects: (Iii) Phenological Applications, Pei Jian Shi, Mei Ling Fan, Gadi V.P. Reddy

Faculty Publications

The developmental times of poikilotherms at different stages are significantly affected by temperature. Most mathematical models describing the temperature-dependent developmental rates of poikilotherms are built according to the experimental data at various constant temperatures. However, these models can also be applied to the developmental rates at variable temperatures. It is more meaningful to use models to predict the occurrence times of pest insects that actually represent the completion for a particular developmental stage (e.g., hatching, pupation, eclosion) under a natural thermal environment. For some developmental stages, insects might experience a period of high temperatures. In this case, skewed bell-shaped nonlinear …

The Stadium Effect: Rodent Damage Patterns In Rice Fields Explored Using Giving-Up Densities, Clare R. Jones, Renee P. Lorica, James M. Villegas, Angelee F. Ramal, Finbarr G. Horgan, Grant R. Singleton, Alexander M. Stuart

Faculty Publications

Rodents are globally important pre-harvest pests of rice. In Southeast Asia, rodent damage to growing rice crops is commonly concentrated towards the center of rice fields, away from the field edge, resulting in a clear pattern known as the “stadium effect.” To further understand this behavior of rodent pests and to develop recommendations for future research and management, we examined the relation between giving-up densities (GUDs) and damage patterns. In Tanay, Luzon, Philippines, GUD trays containing pieces of coconut in a matrix of sand were placed at 4 different distances from the field edge to quantify the perceived risk of …

Dietary Factors And Fibroblast Growth Factor-23 Levels In Young Adults With African Ancestry, Dominique Kosk, Holly Kramer, Amy Luke, Pauline Camacho, Pascal Bovet, Jacob Plange Rhule, Terrence Forrester, Myles Wolf, Chris Sempos, Michal L. Melamed, Lara R. Dugas, Richard Cooper, Ramon Durazo-Arvizu

Faculty Publications

Fibroblast growth factor-23 (FGF23), a phosphaturic hormone secreted mainly by osteocytes, maintains serum phosphate levels within a tight range by promoting phosphaturia. Previous studies have mainly focused on the link between FGF23 levels and dietary intake of phosphate, but other dietary factors may also influence FGF23 levels. This cross-sectional study pooled three populations of young adults with African ancestry (452 in Chicago, IL, USA; 477 in Victoria, Seychelles; and 482 in Kumasi, Ghana) with estimated glomerular filtration rate >80 ml/min/1.73 m2 to examine the association of dietary factors based on two 24-h recalls with FGF23 levels measured using a C-terminal …

Hybridization Between Mottled Ducks (Anas Fulvigula Maculosa) And Mallards (A. Platyrhynchos) In The Western Gulf Coast Region, Robert J. Ford, Will Selman, Sabrina S. Taylor

Faculty Publications

Hybridization between species that do not normally interbreed has increased due to human impacts on natural environments, such as habitat alteration or introductions of nonnative species. In particular, the introduction of Mallards (Anas platyrhynchos) globally has led to hybridization with many duck species. In the southeastern United States, hybridization with Mallards is a potential threat to the genetic identity of Mottled Ducks (A. fulvigula), a nonmigratory, coastal duck species. Hybridization between Mallards and Mottled Ducks has been examined in South Carolina and Florida, but not extensively in the remaining part of the Mottled Duck range. Mottled Ducks introduced into South …