Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Louisiana State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 841 - 870 of 2496

Full-Text Articles in Life Sciences

Evaluation Of Dopaminergic And Antidopaminergic Agents For Use In Equine Metabolic Physiology, Nicole Arana Valencia Jun 2018

Evaluation Of Dopaminergic And Antidopaminergic Agents For Use In Equine Metabolic Physiology, Nicole Arana Valencia

LSU Doctoral Dissertations

A series of experiments studied the effects and practical applications of dopaminergic and antidopaminergic compounds in equine metabolic physiology. The first experiment was performed to assess the long-term effects of repeated cabergoline injections (every 10 days for a total of seven injections) on prolactin and α-melanocyte stimulating hormone concentrations in insulin insensitive mares. Additionally, the experiment also evaluated the use of cabergoline for improving insulin sensitivity. Plasma prolactin and α-melanocyte stimulating hormone concentrations were suppressed throughout the duration of the experiment even when the mares were challenged with a low-dose dopamine antagonist, sulpiride, the day previous to their subsequent cabergoline …


Computational Analysis Of Papionini Evolution Using Alu Insertions, Vallmer Edward Jordan Ii Jun 2018

Computational Analysis Of Papionini Evolution Using Alu Insertions, Vallmer Edward Jordan Ii

LSU Doctoral Dissertations

Alu elements are primate specific retrotransposons that have remained active throughout the course of primate evolution. As a result of this sustained mobilization. Alu elements are present in greater copy number in primate genomes than any other transposable element. An average of over one million Alu elements has been identified in every sequenced haplorrhine genome to date. These characteristics qualify Alu elements as ideal characters for studying evolutionary relationship among primates.

The increasing availability of whole genome sequencing data presents novel challenges and opportunities for comparative genomic analyses. Genomic data is now publicly available for most primate species. Such an …


Susceptibility Of Field-Collected Pupations Of The Corn Earworm, Helicoverpa Zea (Boddie) (Lepidoptera: Noctuidae) From Three Southern States Of The U.S. To Cry1a.105 And Cry2ab2 Proteins, Gagandeep Kaur Jun 2018

Susceptibility Of Field-Collected Pupations Of The Corn Earworm, Helicoverpa Zea (Boddie) (Lepidoptera: Noctuidae) From Three Southern States Of The U.S. To Cry1a.105 And Cry2ab2 Proteins, Gagandeep Kaur

LSU Master's Theses

The corn earworm (CEW), Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), is a major target pest of pyramided Bt corn and Bt cotton in the U.S. In 2016 and 2017, notable corn ear damage and larval survival of CEW were observed on pyramided Cry1A.105/Cry2Ab2 corn in some fields in northeast Louisiana. The objectives of this study were 1) to determine if the ear damage and larval survival observed in the area were due to resistance development to the Bt proteins in the plants, and 2) if resistance had occurred, to determine the approximate distributions of the resistance in the southern region of …


A Study Of Scalability And Cost-Effectiveness Of Large-Scale Scientific Applications Over Heterogeneous Computing Environment, Arghya K. Das Jun 2018

A Study Of Scalability And Cost-Effectiveness Of Large-Scale Scientific Applications Over Heterogeneous Computing Environment, Arghya K. Das

LSU Doctoral Dissertations

Recent advances in large-scale experimental facilities ushered in an era of data-driven science. These large-scale data increase the opportunity to answer many fundamental questions in basic science. However, these data pose new challenges to the scientific community in terms of their optimal processing and transfer. Consequently, scientists are in dire need of robust high performance computing (HPC) solutions that can scale with terabytes of data.

In this thesis, I address the challenges in three major aspects of scientific big data processing as follows: 1) Developing scalable software and algorithms for data- and compute-intensive scientific applications. 2) Proposing new cluster architectures …


Effects Of Oil On Mollusk And Crustacean Populations, Behavior, And Predator-Prey Interactions, Elizabeth Marie Robinson Jun 2018

Effects Of Oil On Mollusk And Crustacean Populations, Behavior, And Predator-Prey Interactions, Elizabeth Marie Robinson

LSU Doctoral Dissertations

The Deepwater Horizon blowout and oil spill in April 2010 released ~5 million barrels of oil into the Gulf of Mexico. Approximately 1,773 km of shoreline was oiled along the northern Gulf of Mexico coast, and ~60% of the oiling ended up on Louisiana salt marsh habitat. The objective of this dissertation was to examine the effects of DWH oil on predator-prey relationships between blue crabs and periwinkle snails, as well as mollusk and blue crab population structure. A broad spatial-temporal field study in Barataria and Terrebonne Bays was used to examine the legacy of oil on five species of …


Evaluation Of Microbial Safety And Quality Of Louisiana Strawberries After Flooding, Shifa Shiraz Jun 2018

Evaluation Of Microbial Safety And Quality Of Louisiana Strawberries After Flooding, Shifa Shiraz

LSU Master's Theses

Rainfall and flooding have impacted the strawberry industry in Louisiana. Floodwater is an ideal medium for microbiological growth and may cause contamination of soil, agricultural water, and fresh produce with foodborne pathogens. This research aimed to evaluate the microbial safety and quality of strawberries after flooding. Three strains of generic Escherichia coli were used to establish a baseline population of approximately 106 CFU/L (high contamination) and 102 CFU/L (low contamination) in floodwater. Five raised beds were filled with water to simulate a flooding event. Simulated floodwater was mixed with cow manure and spiked with generic E. coli then …


Role Of Neutrophils In The Modulation Of Host Responses To Human Respiratory Pneumovirus Infection, Nagarjuna Reddy Cheemarla Jun 2018

Role Of Neutrophils In The Modulation Of Host Responses To Human Respiratory Pneumovirus Infection, Nagarjuna Reddy Cheemarla

LSU Doctoral Dissertations

Neutrophils are the most abundant leukocytes (50% to 70%) in humans and are the first immune cell population recruited to the sites of infection. They are known to act as the first line of innate immune defense against invading pathogens, and more recently, to playing a crucial role in orchestrating adaptive immune responses. The role of neutrophils in the respiratory viral infections till date remains unclear and controversial. Previous studies demonstrated both beneficial as well as pathogenic role for neutrophils in respiratory viral infections, especially influenza.

Previous findings reported an early and high influx of neutrophils into the airways early …


Survival And Inactivation Of Salmonella Enterica And Human Norovirus On Consumer Contact Surfaces, Dorra Simmons Jun 2018

Survival And Inactivation Of Salmonella Enterica And Human Norovirus On Consumer Contact Surfaces, Dorra Simmons

LSU Doctoral Dissertations

Salmonella enterica and human norovirus (HuNoV) are the leading cause of bacterial and viral gastroenteritis worldwide, respectively. One of the most important transmission routes of these pathogens is contaminated surfaces. In this study, we investigated the survival and the disinfection of Salmonella enterica serovar Typhimurium (S. Typhimurium) and HuNoV on selected consumer contact surfaces.

In the case of S. Typhimurium, formica laminate, stainless steel, and plastic cutting board surfaces were inoculated with different microbial loads of cells collected at log (6 h), stationary (24 h), or LTS (14 days) phases. The disinfection efficacy of two disinfectants (sodium hypochlorite or …


Delivering Entrapped Lactobacillus Plantarum Ncimb 8826 With Cereal-Legume Infant-Weaning Food To Improve Children's Gastrointestinal Health, Emmanuel Kyereh May 2018

Delivering Entrapped Lactobacillus Plantarum Ncimb 8826 With Cereal-Legume Infant-Weaning Food To Improve Children's Gastrointestinal Health, Emmanuel Kyereh

LSU Doctoral Dissertations

Diarrhea remains the second leading cause of death among children under five globally, about one in five children’s deaths are attributable to it. In recent years,’ probiotics have been used as an alternative therapy measure to manage the situation. A promising delivery method that entraps probiotics in infant formula may help prevent or reduce diarrhea. The overall objectives of this study were to deliver entrapped Lactobacillus Plantarum NCIMB 8826 with maize-legume fortified complementary weaning food to reduce diarrhea and improve the gut microbiota. Both in vitro and in vivo models were used in this study and a mouse (C57BL/6 mice …


Analysis Of Chromatin Interactions Of Beaf-Associated Promoters Using 4c, Shraddha Shrestha May 2018

Analysis Of Chromatin Interactions Of Beaf-Associated Promoters Using 4c, Shraddha Shrestha

LSU Doctoral Dissertations

A high degree of chromosome compaction is needed to fit nearly 2 meters of DNA inside a human nucleus of around 10 µm diameter. Correct chromatin folding is crucial to facilitate important nuclear functions such as transcription, DNA replication and DNA repair. Nuclei contain a variety of proteins, many of which help regulate chromatin structure and function. The mechanisms by which these proteins work are diverse and complicated. Here, we study the chromatin interactions of Boundary Element Associated Factor (BEAF) associated sites to gain insight into eukaryotic genome organization. We used circular chromosome conformation capture (4C) technology to detect genome-wide …


An Examination Of Preimplantation Embryos And Endometrium Developed During Induced Aluteal Cycles In The Mare, Chelsey Audra Leisinger May 2018

An Examination Of Preimplantation Embryos And Endometrium Developed During Induced Aluteal Cycles In The Mare, Chelsey Audra Leisinger

LSU Doctoral Dissertations

Changes to the embryonic environment that occur within the first few days of development can have significant effects on subsequent fetal development. The following studies investigate the effects of progesterone-deprivation during the early preimplantation period in the mare. The first study described embryo morphology (diameter, stage, and quality grade) collected from mares with induced aluteal cycles. The second study evaluated the effect of induced aluteal cycles on the future fertility of embryo collections as a potential method for cycle manipulation of embryo donor mares. The third study characterized embryonic and endometrial transcript expression of progesterone-mediated transcripts as well as those …


A Virtual Screen For Protein Targets: Elucidating Druggability In The Human Proteome With Efindsite, Omar Kana May 2018

A Virtual Screen For Protein Targets: Elucidating Druggability In The Human Proteome With Efindsite, Omar Kana

Honors Capstones

No abstract provided.


Characterizing Putative Algal Bicarbonate Transporters In S. Cerevisiae & E. Coli Systems Using Transgenic Vectors, James J. Mickler Apr 2018

Characterizing Putative Algal Bicarbonate Transporters In S. Cerevisiae & E. Coli Systems Using Transgenic Vectors, James J. Mickler

Honors Capstones

No abstract provided.


Within Season Hematological Changes In College Athletes With Sickle Cell Trait, Michael E. Owens Apr 2018

Within Season Hematological Changes In College Athletes With Sickle Cell Trait, Michael E. Owens

LSU Master's Theses

ABSTRACT

PURPOSE: To explore the hematological differences in African-American athletes with sickle cell trait (SCT) and healthy controls (CON) before preseason camp and the changes that occur after a full season. METHODS: Sixteen (n=8 SCT; n=8 position matched, CON) NCAA Division 1 athletes (12 football, 2 each women’s soccer and volleyball) had blood drawn before preseason camp, after and at the end of the season, and analyzed for Hb electrophoresis (Hb-A, Hb-A2, Hb-S, and Hb-F), complete blood count with differential, chemistry panel 26, and prothrombin time, activity and international normalized ratio (INR). RESULTS: Baseline total Hb was …


Effect Of Vitrification On Epigenetic Modifications And The Meiotic Spindle Of Bovine Oocytes, Emilio Jose Gutierrez-Castillo Apr 2018

Effect Of Vitrification On Epigenetic Modifications And The Meiotic Spindle Of Bovine Oocytes, Emilio Jose Gutierrez-Castillo

LSU Master's Theses

While oocyte vitrification has become a common practice, it still faces some challenges such as the low survival rates after warming, probably related to cryoinjuries and cryoprotectant (CPA) toxicity. Evidence suggests that vitrification might have an effect on the patterns of some epigenetic marks including DNA methylation and histone acetylation. During fertilization and embryogenesis, key events for healthy and adequate embryo development take place, not only governed by the information contained within the DNA sequence, but also by epigenetic mechanisms.

This study was aimed at determining the effect of vitrification and CPA exposure, using a combination of ethylene glycol (EG) …


Paclitaxel Enhances Oncolytic Potential Of Herpes Simplex Virus Type-1 In Cancer Cells, Misagh Naderi Apr 2018

Paclitaxel Enhances Oncolytic Potential Of Herpes Simplex Virus Type-1 In Cancer Cells, Misagh Naderi

LSU Master's Theses

Taxanes are spindle poisons that bind to and stabilize microtubules resulting in mitotic arrest. Herpes simplex Typ-1 (HSV-1) virions utilize the microtubular network for intracellular transport during both virus entry and virus egress from infected cells. It has been reported previously that taxanes may synergize with oncolytic herpes simplex viruses in the treatment of experimental prostate and breast tumors in mice. Other reports have indicated that taxanes may inhibit viral replication in infected cells. In this study the previously characterized Oncolytic Herpes Simplex Virus type 1 (OSVP), which was constructed in Kousoulas lab was used in conjugation with paclitaxel (taxol) …


Effect Of Increasing Levels Of Monosilicic Acid On Arsenic And Phosphorus Sorption In Soil, Flávia Bastos Agostinho Apr 2018

Effect Of Increasing Levels Of Monosilicic Acid On Arsenic And Phosphorus Sorption In Soil, Flávia Bastos Agostinho

LSU Doctoral Dissertations

Arsenic (As) accumulation in rice (Oryza sativa) grains has increased human’s daily intake. Studies have shown that arsenite is taken up through known silicon (Si) transporters in rice. Moreover, the availability of As in soil is affected by chemically similar ligands that have high affinity to oxides surfaces, such as Si and phosphorus (P). Studies were conducted to: (I) investigate the role of elevated levels of Si on the concentration of different As fractions in soil and on As uptake by rice; (II) evaluate the effect of increasing monosilicic acidconcentrations on As sorption and kinetics in soil; and …


Effects Of Application Timing And Soil Type On Optimal N Rate Requirement Of Sugarcane (Saccharum Spp.) And Changes In Soil Inorganic And Leaf N Concentrations, Joseph Martin Garrett Apr 2018

Effects Of Application Timing And Soil Type On Optimal N Rate Requirement Of Sugarcane (Saccharum Spp.) And Changes In Soil Inorganic And Leaf N Concentrations, Joseph Martin Garrett

LSU Master's Theses

Research is limited on the effects of soil types and early nitrogen (N) fertilizer applications to N management strategies in sugarcane (Saccharum spp.) production in Louisiana. This study was established in 2015 at two locations in St. Gabriel, LA to 1) determine the effect of fertilizer application timing and soil type on the optimal N rate requirement and yield of sugarcane and 2) relate the relationship of soil and leaf N content to yield at different growth stages with sugarcane yield. Treatments were set in a randomized block design on a clay soil and in a complete randomized …


Data-Driven Computational Approach To Study Bio-Molecular Interactions, Misagh Naderi Apr 2018

Data-Driven Computational Approach To Study Bio-Molecular Interactions, Misagh Naderi

LSU Doctoral Dissertations

Proteins commonly convey their functions in coordination with other proteins, small molecules and/or other biological assemblies such as sugars, lipids, DNA or RNA. Understanding the nature of these interactions is therefore central to improving our knowledge of biological systems. This body of work is a consolidation of three different computational approaches to study bio-molecular interactions: large-scale protein-ligand modeling, fragment-based cheminformatics, and computational analysis of interactions in single proteins.

The first issue that is addressed in this study is the scarcity of atomic crystal structures of protein-drug complexes. In general, a drug molecule’s affinity for multiple protein targets may causes unsolicited …


Characterization Of The Interaction Between R. Conorii And Human Host Vitronectin In Rickettsial Pathogenesis, Abigail Inez Fish Apr 2018

Characterization Of The Interaction Between R. Conorii And Human Host Vitronectin In Rickettsial Pathogenesis, Abigail Inez Fish

LSU Doctoral Dissertations

Spotted Fever Group Rickettsia are inoculated into the mammalian host during hematophagous arthropod feeding. Once in the bloodstream and during dissemination, the survival of these pathogens is dependent upon their ability to evade innate host defenses until a proper cellular target is reached. The establishment of a successful infection also relies on the ability of the bacteria to attach and invade target cells, as failure to do so results in destruction of the bacterium. Rickettsia conorii expresses an outer membrane protein, Adr1, which binds the multifunctional human glycoprotein, vitronectin, to promote resistance to complement mediated killing. Homologs of Adr1 are …


Functional Plain Yogurt Enhanced With Inulin And Aloe Vera, Janny Melissa Mendoza Mencia Apr 2018

Functional Plain Yogurt Enhanced With Inulin And Aloe Vera, Janny Melissa Mendoza Mencia

LSU Master's Theses

Yogurt has been recognized as a healthy food. Nutritional value of yogurt can be increased with the addition of aloe vera juice (AVJ) and inulin. People are interested in consuming products without artificial ingredients and with high content of bioactive compounds. The aims of this study were to develop a functional plain yogurt enhanced with inulin and AVJ, to evaluate the physicochemical properties, the enumeration of Streptococcus thermophilus and Lactobacillus bulgaricus, inulin content, and consumer acceptability. Six treatments were evaluated at day 1, 7, 14 and 30 at 4°C. Treatments were prepared using 2% fat milk, ABY culture, 5 …


Cloning, Purification, And Preliminary Dna-Binding And Unfolding Results For The Dna Polymerase I From The Psychrophile Psychromonas Ingrahamii, John Tod Baker Apr 2018

Cloning, Purification, And Preliminary Dna-Binding And Unfolding Results For The Dna Polymerase I From The Psychrophile Psychromonas Ingrahamii, John Tod Baker

LSU Master's Theses

Psychromonas ingrahamii is a psychrophilic bacterium that lives in Arctic polar sea ice and grows at a temperature range of -12 to 10º C. This bacterium resides within veins inside the ice where the salinity is high, resulting in a freezing point depression and liquid water. The large fragment of DNA polymerase I from Psychromonas ingrahamii, called Klenpin, has been cloned, expressed, and purified in our laboratory. Although enzyme kinetic studies have been performed on a few psychrophilic enzymes, the thermodynamics of ligand binding and of protein stability have not been well studied for this class of extremophilic proteins. …


Analysis Of Submerged Aquatic Vegetation Resources Across The Northern Gulf Of Mexico: Communities And Biomass, Eva R. Hillmann Apr 2018

Analysis Of Submerged Aquatic Vegetation Resources Across The Northern Gulf Of Mexico: Communities And Biomass, Eva R. Hillmann

LSU Doctoral Dissertations

Submerged aquatic vegetation (SAV) provides many critical ecosystem services, yet we lack basic information on SAV assemblages, biomass and diversity across expansive coasts such as the northern Gulf of Mexico (nGoM). This research investigated SAV along the nGoM from 2013-2015 examining (1) inter-annual variation in SAV assemblages and biomass across salinity zones and gulf coast eco-regions (Texas Mid-Coast, Texas/LA Chenier Plain, Louisiana Delta, MS/AL), (2) intra-annual variation in SAV assemblages and biomass across salinity zones, (3) response of two species, Ruppia maritima and Myriophyllum spicatum, to salinity and light regimes, and (4) estimated organic carbon stock and storage of …


Whole Tart Cherry Improves Disease Activity Index In Rat Model Of Dextran Sulfate Solution – Induced Ulcerative Colitis By Downregulating The Janus 1 And Janus 3 Kinases And Tnf - Alpha, Johana Alexandra Coronel Apr 2018

Whole Tart Cherry Improves Disease Activity Index In Rat Model Of Dextran Sulfate Solution – Induced Ulcerative Colitis By Downregulating The Janus 1 And Janus 3 Kinases And Tnf - Alpha, Johana Alexandra Coronel

LSU Master's Theses

Ulcerative colitis (UC) is a disabling inflammatory bowel disease. UC is characterized by chronic, relapsing inflammation of the colon and rectum. Current treatments such as monoclonal antibodies against TNF-α, IL-6, IL-12/p40, adhesion molecules, Janus kinases (JAK) inhibitors have side effects or lose their effects over time. Alternative approaches with fewer side effects for patients are needed. Montmorency tart cherries (Prunus cerasus) are a good source of anti-inflammatory flavonoids. We hypothesized that regular consumption whole tart cherry (TC) standardized to its major anthocyanin content, namely cyanidin-3-glucosyl-rutinoside, would be effective in reducing inflammation in UC. The aim of this research was to …


Effects Of Enhanced Efficiency Nitrogen Fertilizers On Agronomic Parameters And Loss Pathways In The Subtropical Mississippi Delta Region, Scott Michael Pensky Apr 2018

Effects Of Enhanced Efficiency Nitrogen Fertilizers On Agronomic Parameters And Loss Pathways In The Subtropical Mississippi Delta Region, Scott Michael Pensky

LSU Master's Theses

Minimizing nitrogen (N) loss is critical for improving N use efficiency (NUE) in crop production and reducing its effects on the environment. Management practices such as seasonal application timing of N fertilizers and the addition of enhanced efficiency N fertilizers (EENFs) were investigated for the high N requirement of the two most common cereal crops globally, corn (Zea mays L.) and wheat (Triticum aestivum L.), in the subtropical climate of Louisiana. Field research was established during the 2016 and 2017 seasons at the LSU Agricultural Center’s Dean Lee and Central research stations to examine the effect of different EENFs and …


Effects Of Dimethyl Sulfoxide And Glycerol Based Vitrification Protocols On Zona Pellucida Hardening In Mature Bovine Oocytes, Kaci Denise Rogers Apr 2018

Effects Of Dimethyl Sulfoxide And Glycerol Based Vitrification Protocols On Zona Pellucida Hardening In Mature Bovine Oocytes, Kaci Denise Rogers

LSU Master's Theses

Zona pellucida hardening is a natural process that occurs after oocyte fertilization to prevent polyspermic fertilization and to protect embryonic development. Pre-fertilization hardening of the zona pellucida however, decreases fertilization rates. Cryoprotectants have also been shown to negatively affect fertilization rates, one possible mechanism of which being through zona hardening. This experiment was conducted to determine the effect of different cryoprotectants on hardening of the zona pellucida using fresh mature bovine oocytes and vitrified mature bovine oocytes. Oocytes were post-slaughter from mixed breed cows. After collection, oocytes were randomly assigned to three cryoprotectant treatment groups: dimethyl sulfoxide (DMSO), glycerol or …


Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye Apr 2018

Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye

LSU Master's Theses

Sugarcane (Saccharum spp) production is an integral part of Louisiana's economy. Proper fertilizer management, particularly nitrogen (N) and potassium (K), optimizes sugarcane production. An experiment was established in 2015 at the LSU AgCenter Sugar Research Station in St. Gabriel, Louisiana to: (1) assess the effect of N and K fertilizer sources on sugarcane yield and quality parameters, and (2) monitor the changes in inorganic N and K levels in the soil at different sugarcane growth stages. The experiment was arranged in a randomized complete block design on a Sharkey clay soil and complete randomized design on a Commerce …


Breaking Conventions: Ohrr, A Transcriptional Regulator From Burkholderia Thailandensis, Anuja Rajiv Pande Apr 2018

Breaking Conventions: Ohrr, A Transcriptional Regulator From Burkholderia Thailandensis, Anuja Rajiv Pande

LSU Doctoral Dissertations

Organic peroxides (OPs) are highly toxic oxidants. They directly react with cellular macromolecules rendering them inactive. Soil bacteria live in an oxidative environment rich in OPs from plant exudates and other xenobiotic compounds. Bacteria also face a burst of organic peroxides (lipid peroxides) in the macrophages during host invasion. Prokaryotes sense oxidative changes in environment and modulate their gene expression as an adaptive response for survival. MarR (multiple antibiotic resistance regulators) proteins enable bacteria to respond to such stress. Resistance to organic oxidants has been hypothesized to help bacteria survive in presence of disinfectants. This increases nosocomial infection rate.

Bacteria …


Impact Of Sorghum Cultivar, Phenology, Nitrogen, And Silicon Fertilization On Melanaphis Sacchari Biology, Luna Lama Apr 2018

Impact Of Sorghum Cultivar, Phenology, Nitrogen, And Silicon Fertilization On Melanaphis Sacchari Biology, Luna Lama

LSU Master's Theses

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is an invasive pest of grain sorghum, Sorghum bicolor (L.) Moench. Since its first outbreak in sorghum in 2013, severe infestations have spread throughout the southern U.S. causing high economic losses. While insecticidal control has mitigated some of the impacts of this pest, a sustainable ecology-based management program is needed to reduce reliance on chemical control. We studied the effects of silicon (rates equivalent to 0 and 3360 kg Si/ha) and nitrogen (rates equivalent to 0, 110, and 220 kg N/ha) on M. sacchari growth and reproduction on resistant (DKS 37-07) and …


Changes In Carbon, Nutrient, And Trace Metal Concentrations During The Transition From Freshwater To Marine Environments - A Case Study In Southwest Louisiana, Songjie He Apr 2018

Changes In Carbon, Nutrient, And Trace Metal Concentrations During The Transition From Freshwater To Marine Environments - A Case Study In Southwest Louisiana, Songjie He

LSU Doctoral Dissertations

Rivers carry terrestrial nutrients and other materials to estuaries, affecting biogeochemical cycles and ecosystems in coastal margins. This dissertation research incorporated five studies to investigate the dynamics of carbon, nutrients, and trace metals in four major coastal rivers in southwest Louisiana – the Sabine, Calcasieu, Mermentau, and Vermilion Rivers. The overarching goal of this research was to broaden the knowledge and understanding of biogeochemical processes in freshwater – saltwater mixing zones. These studies employed decade-long monitoring records of water chemistry, utilized monthly field measurements conducted over a two-year period, and used analysis of over 200 water samples for carbon, nitrogen, …