Life Sciences Commons^™

Sediment And Plant Dynamics In A Degrading Coastal Louisiana Landscape, Glenn Michael. Suir

LSU Doctoral Dissertations

Alterations to Louisiana’s river systems and local hydrology have resulted in reduced freshwater, sediment, and nutrient inputs into wetland landscapes, causing significant negative impacts on marsh productivity and stability. To combat these losses many restoration projects have been constructed or planned throughout coastal Louisiana. Typical goals of wetland restoration efforts are to conserve, create, or enhance wetland form, and to achieve wetland function that approaches natural conditions. Failure to adequately maintain wetland elevation and hydrology can have serious implications on sedimentation and vegetation processes, which significantly reduces the likelihood of reaching structural and functional targets. Measures of wetland condition have …

5-Lipoxygenase (5-Lox)-5-Lipoxygenase Activating Protein (Flap)-Nanodisc Complex: A Model For The 5-Lox-Flap Interaction, Erin Elizabeth Schexnaydre

LSU Doctoral Dissertations

Leukotrienes (LT) are lipid mediators of the inflammatory response that play important roles in diseases such as asthma and atherosclerosis. Leukotriene A4 (LTA₄) is synthesized from arachidonic acid (AA) by 5-lipoxygenase (5-LOX) with the help of 5-lipoxygenase activating protein (FLAP), a trimeric nuclear transmembrane protein. Exactly how 5-LOX and FLAP interact is not well understood, however FLAP is essential for the production of leukotrienes in vivo. I used nanodiscs (NDs), engineered membrane systems, as a tool to study the 5-LOX-FLAP interaction. FLAP was incorporated into NDs with a phospholipid composition to mimic of the nuclear membrane. Structural features …

The Influence Of River Discharge On Fishes And Invertebrates Associated With Small Oil And Gas Platforms In Nearshore Louisiana, David Bradley Reeves

LSU Doctoral Dissertations

The nearshore region off Louisiana’s coast is one of the most productive areas in the United States. Nutrient-rich discharge from the Mississippi and Atchafalaya rivers forms the base of this productivity, but it also contributes to the annual formation of a large hypoxic zone (DO < 2.0 mg l^-1). This region contains >900 oil and gas platforms (platforms) that are de facto artificial reefs and support fish and invertebrate communities. In this dissertation, I examined how select platform-associated fishes and invertebrates responded to river-driven productivity and hypoxia. Settlement plates were used to compare barnacle production at depths of 2 and 7-m along …

The Determinants Of Nucleosome Patterns And The Impact Of Phosphate Starvation On Nucleosome Patterns And Gene Expression In Rice, Qi Zhang

LSU Doctoral Dissertations

In eukaryotic cells, DNA is a large molecule that must be greatly condensed to fit within the nucleus. DNA is wrapped around histone proteins to form nucleosomes, which facilitate DNA condensation, but on the other hand, may limit DNA processes. Organisms must respond to environmental stress in order to survive, and one strategy is by remodeling nucleosomes to promote changes in DNA accessibility to alter gene expression. Studies have demonstrated a clear correlation between nucleosome dynamics and transcriptional change in some eukaryotes, however factors that affect nucleosome positioning in plants are largely unknown, and the correlation between nucleosome dynamics and …

Legacy Contaminants In The Northern Gulf Of Mexico Shelf, Jessica N. Landry

LSU Master's Theses

The Mississippi River watershed is the third largest in the world and drains from 31 states in the United States. Due to its route through the U.S., it passes through hundreds of EPA labeled Superfund sites as well as agricultural and suburban watersheds. These sites are known to have historical chemical contamination, and as a result chemicals can be transported by runoff down the Mississippi River into the Gulf of Mexico where their ultimate fate is unknown. Organochlorine chemicals are known to be persistent and are found in agricultural land as well as US EPA Superfund sites, especially DDT, PCBs, …

Upregulation Of Coilin Mrna Upon Nopp140-/- In Drosophila Melanogaster., Sara Grace Hubacek

Honors Capstones

No abstract provided.

The Tensile Root Strength Of Emergent Coastal Macrophytes, Lauris Olivia Hollis

LSU Doctoral Dissertations

Spartina patens is a dominant emergent macrophyte in fresh, intermediate, and brackish marshes along the Atlantic and Gulf coasts of United States where its biomechanical properties are a key component of wetland health and resilience. Its root biomass and tensile root strength are essential for anchorage, erosion protection, and are important determinants of soil strength. Nutrients and the herbicide atrazine are suspected of negatively impacting this wetland plant and others. The objectives of this study were to: 1) ascertain the tensile root strength of five emergent coastal macrophytes in coastal estuaries, and 2) test the effects of nutrient addition, atrazine …

Unintended Consequences For Tanf: An Incubator For Domestic Violence?, Kathryn Rose Deleo

Honors Capstones

No abstract provided.

First Record Of The Non-Native Pacu, Piaractus Brachypomus, In Lago Petén-Itzá, Guatemala, Central America, Diego J. Elias, Susan F. Mochel, Prosanta Chakrabarty, Caleb D. Mcmahan

Occasional Papers of the Museum of Natural Science, Louisiana State University

We documented the first record of the non-native species Piaractus brachypomus (Characiformes: Serrasalmidae) in Lago Petén-Itzá, Petén, Guatemala. One brined specimen was donated by a local fisherman in San Benito, El Petén. The captured specimen was reportedly collected in the southern basin of the lake. We used the mitochondrial gene cytochrome oxidase I (COI) to validate identity of the specimen. We hypothesize that the local aquarium trade is the most likely source of introduction of the non-native Pacu in Lago Petén-Itzá.

Documentamos el primer registro de la especie no nativa Piaractus brachypomus (Characiformes: Serrasalmidae) en el lago Petén Itzá, Petén, …

Evaluation Of Growth Characteristics, Yield, Marketability And Nitrate Levels Of Lettuce (Lactuca Sativa L) Cultivars Produced In South Louisiana, William D. Afton

LSU Master's Theses

Lettuce (Lactuca sativa L.) is an important leafy vegetable crop grown in worldwide food systems with the United States ranking second behind China in total production. In 2009 the USDA Food Economic Research Service reported 1,057,715 hectares of lettuce grown in the world. Lettuce is a common market crop grown across the United States. Nitrate (NO^3-) accumulation in lettuce and other leafy vegetables has been found to be a potential health threat and when consumed by humans, potentially causing methaemoglobinaemia and other diseases. There are four main types of lettuce and numerous cultivars within each type. Fresh …

Crayfish Harvesting Practices In The Southern Atchafalaya River Basin: Quantitative And Qualitative Assessment Of Harvester Techniques And Hydrologic Connectivity Influence On Harvesting Strategies, Ivan A. Vargas-Lopez

LSU Master's Theses

Fisheries produce important impacts around the world through the exploitation of a wide range of species. In Louisiana, crayfish is the most emblematic crustacean and supports a multi-million industry based on pond culture and harvest from natural habitats. Although the economic value (USD) of wild-harvested crayfish has decreased from 10% to 3% of total crayfish value from 2013 to 2015, wild harvested crayfish are highly desired by many consumers and have a strong socio-cultural importance in Louisiana and other Gulf of Mexico coastal regions. This project evaluated harvesting practices by: 1) field observation and mapping of harvest sites in southwestern …

Examining Louisiana State University Undergraduate College Of Agriculture Students' Intention To Participate In Study Abroad, Timothy K. Sandles

LSU Doctoral Dissertations

The purpose of this study was to examine Louisiana State University (LSU) undergraduate College of Agriculture (COA) students’ intention to participate in study abroad. This study aimed to add to the body of research that utilizes Ajzen’s Theory of Planned Behavior as a theoretical framework by exploring COA undergraduate students’ intention to participate in study abroad. This study sought to determine if relationships existed among students’ prior intercultural experiences, perceived motivating factors related to study abroad, perceived barriers to study abroad, outcome expectations, attitude toward study abroad, and students’ intention to participate. Additionally, the study utilized structural equation modeling (SEM) …

The Effects Of Tree Plantations And Land Use On Natural Regeneration Of Woody Plants In The Tropics: Diversity, Species Composition, Successional Dynamics, And Functional Traits, John Benjamin Longworth

LSU Doctoral Dissertations

As anthropogenic forests become more common in the tropics, there is a greater need to understand the factors that impact forest succession. I used censuses of woody plants in successional forests to study the effects of prior land use and tree plantations on species composition and richness. First, I tested the hypothesis that communities originating from different land uses were converging in species composition over time. I compared species composition using the Chao-Jaccard similarity index. I observed shifts in the dominant species during the first 30 years of succession, but not convergence of species composition in sites with different land-use …

Interaction Of Cocoa Powder With Intestinal Microbiota, Zuyin Li

LSU Doctoral Dissertations

Cocoa powder contains polyphenolic compounds, which can provide potential health benefits to humans. The human gastroinestinal tract hosts diverse microorganisms which are called the human gut microbiota. These microbes can utilize carbohydrates through fermentation resulting in the production of short chain fatty acids (SCFAs), which cause a reduction of pH in gastroinestinal tract. The cocoa processing can change the composition of the carbohydrates, which can affect the fermentation patterns.

In this study we established an in vitro model system which simulated gastric digestion and colon fermentation. Five different processed cocoa samples (alkalized cocoa samples: D-11-B and D-11-S; non-alkalized cocoa samples: …

Determining Bioindicators For Coastal Tidal Marsh Health Using The Food Web Of Larvae Of The Greenhead Horse Fly (Tabanus Nigrovittatus), Devika Rajeev Bhalerao

LSU Master's Theses

The greenhead horse fly Tabanus nigrovittatus Macquart is native to coastal marshlands from Texas to Nova Scotia. The larvae are apex invertebrate predators and their development is dependent on the food web in the soil. Surveillance of T. nigrovittatus after the 2010 Deepwater Horizon oil spill in the Gulf of Mexico showed population crashes of adults in the coastal marshes of East Louisiana near places where oil made landfall, but not in West Louisiana where the oil did not reach. Sediment collection in 2011 from West and East Louisiana revealed larval population crashes in the Eastern coastal region. We hypothesized …

Carbon Dioxide Fluxes And Plants Interactions Across The Succession Of A Created Brackish Marsh In Southwestern Louisiana, Andy T. Muench

LSU Master's Theses

The purpose of this study was to examine: 1) carbon dioxide (CO₂) fluxes in different plant communities in a created and natural brackish marsh and 2) the role of an early colonizing species, Spartina alterniflora, in facilitating or suppressing a later colonizer and higher marsh species, Spartina patens. CO₂ fluxes were measured in four key successional stages: 1) non-vegetated sediment of a newly created marsh; 2) Spartina alterniflora-dominated areas of a newly created marsh; 3) S. alterniflora-dominated natural marsh; and 4) Spartina patens- dominated natural marsh. Spartina alterniflora-dominated areas were sinks for …

Louisiana Agriculture Winter, 2018, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Simulating The Effects Of Co2 Gas Influx On The Thermodynamic Conditions Inside A Marine Riser Filled With Oil Based Mud, Hassan Al Dawood

Honors Capstones

No abstract provided.

Dna Base Excision Repair And Double Strand Break Repair In Human Fibroblast, Mingyang Li

LSU Doctoral Dissertations

In eukaryotes, DNA repair mechanisms detect and repair damaged DNA. DNA damage is primarily caused by a variety of exogenous and endogenous sources. Several types of damage to DNA are repaired by different kinds of DNA repair pathways. This dissertation focused on repair of N-methylpurines (NMPs) and double-strand breaks (DSBs) in human fibroblasts.

NMPs, including N⁷-methylguanine (7MeG) and N³-methyladenine (3MeA), can be induced by environmental methylating agents (e.g. the soil fumigant methyl bromide), chemotherapeutics (e.g. nitrogen mustards), and natural cellular methyl donors like S-adenosylmethionine. In human cells, NMPs are repaired by the multi-step …

Habitat Selection, Survival, And Movement Ecology Of The American Woodcock (Scolopax Minor) In Louisiana Usa, Elisa Constancia Elizondo

LSU Master's Theses

The American Woodcock (Scolopax minor) is a migratory upland game species occurring across much of eastern North America. Across its breeding range in the northern U.S. and southern Canada, this species has experienced significant, pervasive declines over the last half century. As woodcock populations continue to decline, active habitat management for this species has become increasingly important.

The state of Louisiana has substantial amounts of woodcock habitat and receives wintering birds from across the woodcock range. However, few data exist regarding survival rates, habitat utilization, and movement patterns across the state.

In order to better manage for woodcock …

Patterns In Abundance Of Louisiana’S Avifauna Revealed By The Louisiana Bird Atlas Project, Matthew L. Brady

LSU Master's Theses

The Louisiana Bird Atlas Project is a multi-year citizen science effort designed to quantify bird distribution and abundance for all species regularly occurring in the state of Louisiana during two time periods: summer and winter. Data were collected by volunteers in a citizen science framework across eight years, from 2007 to 2014. A total of 351 species was recorded (254 during the Summer Bird Atlas and 315 during the Winter Bird Atlas). Maps showing distribution and relative abundance for each species were generated within a Geographical Information System, and were accompanied by short descriptions of status, distribution, abundance, and other …

A Study Of The Urban Red Fox (Vulpes Vulpes) Population In Baton Rouge, Louisiana Using Social Media, Ahsennur Soysal

LSU Master's Theses

Foxes are timid yet resourceful animals that are integrated into many urban environments. Because they are elusive, collecting information about the number of urban foxes, their diet and spatial distribution, their interactions with the ecological community in their urban habitat, as well as residents’ response to them, is difficult. Involving stakeholders to participate in the data collection on wildlife via citizen science on social media is one way to overcome this complication, while simultaneously engaging residents in the ecology happening around them. Therefore, we used social media as the platform to engage the public to document and map the foxes …

Growth And Development Of Two Broiler Strains With Low Protein And Crystalline Amino Acid Supplemented Diets, Chaoyang Li

LSU Master's Theses

The objective of this research was to compare the growth performance of broilers from two commercial breeds with control, low protein and low protein supplemented with crystalline amino acids diets. This was a randomized block design, and identical experiments were conducted on successively in two years. In each experiment, day-old chicks, Ross 708 broilers and Cobb 405 broilers, were randomly assigned into three dietary treatments: 1) positive control, 2) low crude protein (LP), and 3) LP + crystalline amino acids (CAA). A three phase feeding program was used. Feed and water were provided ad-libitum. On d 12, 19, 26, 33, …

Distinguishing Isolates Of Rotylenchulus Reniformis Endemic In Louisiana On The Basis Of Root-Associated Females And Egg Masses, Benjamin Mcinnes

LSU Master's Theses

The reniform nematode Rotylenchulus reniformis is a major pathogen of soybean and cotton in Louisiana. Previous studies have shown that populations of reniform nematode throughout the southern United States vary in reproduction and pathogenicity. Limited studies have been conducted to evaluate the reproduction and pathogenicity of populations of R. reniformis endemic in Louisiana. Studies with isolates of the nematode from eight cotton-producing parishes focused solely on reproduction of the root-associated infective and swollen female life stages with and without attached egg masses on the cotton genotypes MT2468 Ren3, M713 Ren5, and Stoneville 4946GLB2 and the soybean genotypes PI 548316, PI …

Occurrence Of Putative Endornaviruses In Non-Cultivated Plant Species And Characterization Of A Novel Endornavirus In Geranium Carolinianum, Rachel Herschlag

LSU Master's Theses

Endornaviruses are RNA viruses, which can infect plants yet cause no apparent symptoms. To date, most descriptions of endornaviruses infecting plants have been in cultivated species. A survey for endornaviruses in non-cultivated plants was initiated in 2015 and continued through 2017 in Baton Rouge, Louisiana. Two hundred and seven plant species were tested for distinctive dsRNA profiles by selective extraction and gel electrophoresis, of which seven contained endornavirus-like dsRNA. RT-PCR amplification of an endornavirus-specific sequence supported the endornavirus nature of six of the seven samples. Of the six host species, one species, Geranium carolinianum was confirmed as being infected with …

Evaluating The Effect Of Chitosan, Water-Soluble Chitosan And Chitosan Application Techniques On The Quality Of Refrigerated Catfish Fillets, Franklin Bonilla Torres

LSU Master's Theses

Chitosan (CH) is a biopolymer synthetized by deacetylation of chitin, it is found in the exoskeleton of crustaceans, cell wall of fungi, and insects. CH’s water insolubility limited the used of this compound in some food systems. However, enzymatic hydrolysis of CH yields water-soluble chitosan (WSC). The aim of this study was to evaluate the effect of chitosan, water-soluble chitosan, and chitosan application techniques on the quality of refrigerated catfish fillets. This research was conducted in two separated studies. In the first study, three solution treatments were prepared: (1) a 1% acetic acid (AA) solution, (2) a 0.5% CH solution …

Evaluation Of Reproductive Phenology And Ecology Of Eastern Wild Turkey (Meleagris Gallopavo Silvestris) In South Carolina, Patrick Wightman

LSU Master's Theses

Many southeastern states, including South Carolina, in the last 10 -15 years have seen a decline in Eastern wild turkey (Meleagris gallopavo silvestris) populations. Around 50,000 turkey hunters in South Carolina, result in approximately 35 million annually in revenue. Turkeys encounter a unique situation as environmental variation and hunter activity may impact behaviors as hunting occurs during the reproductive season. Mistimed hunting seasons could result in population declines. Timing of harvest requires managers to implement seasons that allow for hunter satisfaction (hearing gobbles) while ensuring no detriment to turkey populations through impacts to reproduction. To better understand factors influencing gobbling …

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 …

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. …

Effects Of Soil Silicon Amendment And Nitrogen Levels On Rice Insect Pest Complex, James Michael P. Villegas

LSU Master's Theses

Rice plants are consistently subjected to various pressures by insect pests throughout the growing season. The main insect pest complex reported in Louisiana are the rice water weevil (major early-season insect pest), fall armyworm (sporadic early-season pest), sugarcane borer and rice stalk borer (long- established but sporadic stem boring pests), Mexican rice borer (an invasive stem-boring pest), and rice stink bug (major late-season pest). Soil silicon amendment has been shown to enhance plant resistance against herbivorous pests. Rice is a typical silicon-accumulating graminaceous crop. Field and greenhouse experiments were conducted from 2015 to 2017 to investigate the effects of soil …