Life Sciences Commons^™

Integrating Cultivar Resistance And Entomopathogens For Pest Management Of Sweetpotato Weevil, Cylas Formicarius Elegantulus (Summers), Schyler M. Lee

LSU Master's Theses

Sweetpotato, Ipomoea batatas (L.) Lam, is the number one vegetable crop in Louisiana, producing 21,178 kg/ha in the year 2021. The sweetpotato weevil, Cylas formicarius elegantulus (Summers), is an economically important pest of sweetpotato. C. formicarius elegantulus females lay eggs into feeding holes on the storage root surface. Larvae then hatch and tunnel through the sweetpotato flesh where they complete their development. This cryptic-natured brentid can cause up to 100% yield loss when left unmanaged. The Louisiana Department of Agriculture and Forestry mandates protocols to limit C. formicarius elegantulus spread (e.g., clean seed, pheromone trapping, and quarantines); however, scheduled chemical …

Molecular Identification Of Oomycete Species Associated With Woody Plants In Louisiana And Survey Of Oomycete Species Associated With Live Oak Trees Planted On The Louisiana State University Campus, Hamilton Crockett

LSU Master's Theses

Three Oomycetes genera, Phytophthora, Phytopythium and Pythium, contain many important plant pathogens. Historically, Phytophthora infestans, responsible for the great Irish potato famine, and Phytophthora ramorum, causal agent of sudden oak death disease, are the two better-known high impact pathogens. The LSU AgCenter Plant Diagnostic Center (PDC) has been isolating putative Phytophthora and related species from combined root and soil samples collected from various woody ornamentals and trees for over a decade. In August of 2016, Louisiana received torrential rains, which resulted in historic flooding in several southern parishes. During subsequent years, the PDC staff isolated a …

Evaluation Of A Nutritional Calming Supplement For Stress Management In Beef Cattle, Randall Mallette

LSU Master's Theses

Two studies were conducted to determine the efficacy of two formulations of a nutritional calming product, Placid 1.0 and Placid 2.0, at keeping beef cattle in a calm state when exposed to environmental factors that put them into an excited state. In the pilot study, nine crossbred beef heifers were orally drenched daily for three days with 60 mL of their respective treatments, pen scores and exit scores were recorded, and blood was collected for cortisol analysis. There were no treatment effects for either treatment on any of the measured behavioral parameters or serum cortisol concentrations.

The products were …

Interactive Effects Of The Partial Pressure Of Co2, Temperature, And Nutrient-Limitation On The Physiology And Growth Of The Coccolithophore E. Huxleyi Grown On A 12:12 L:D Cycle Of Illumination, James Bradley

LSU Master's Theses

I studied the interactive effects of pCO2, temperature, and nutrient limitation on the growth and physiology of the marine coccolithophore, Emiliania huxleyi. This was done to look at the effect of climate change factors on the widespread and abundant calcifying marine organism as a predictor of what the future has to hold. The strain of E. huxleyi (PnB 272 B10) was grown on a 12:12 L:D cycle of illumination and exposed to either high or low pCO2 under nutrient-replete or nitrate-limited conditions across a temperature range of 10–28C. I examined the direct and interactive effects of temperature, pCO2, and nutrient …

Differences In Plant Hormone Responses Between Arabidopsis Thaliana And Schrenkiella Parvula Facing Lithium Toxicities, Jifeng Li

LSU Doctoral Dissertations

Investigating stress responses in plants is central to plant development studies and crop research. Identifying mechanisms of plant abiotic stress tolerance and adaptation will be keys to relieve the conflict between an increasing global population and declining agronomic land. Studies on extremophytes and their genetic responses to environmental stress are a way to help understand how and why these extremophile plants can develop well under extreme environments including high salinity and heavy metal toxicity. The studies herein first focus on comparative responses at the genetic level to lithium toxicity between Arabidopsis thaliana and Schrenkiella parvula. Based on elemental quantification …

Louisiana Agriculture Magazine, Summer 2023

Louisiana Agriculture

Rice, alligators and sugarcane are quintessential Louisiana products, and LSU AgCenter researchers and extension agents devote themselves to helping the producers who grow them. Economists are finding ways to improve the market for alligators while specialists focus on innovation in the sugar industry and creating new varieties of rice.

AgCenter researchers also have an eye on the natural world. They are protecting the roseau cane that thrives on the coast and the ironwood trees of Guam. All these efforts are detailed in this issue of Louisiana Agriculture magazine.

Impact Of Sediment Diversion For Coastal Restoration On Nitrogen And Phosphorus Biogeochemical Cycling In Coastal Louisiana, Usa, Mercedes M. Pinzon Delgado

LSU Master's Theses

Wetlands provide essential ecosystem services and functions, including improving surface water quality through nutrient removal. Louisiana experienced ~4,800 km² of coastal wetland loss between 1932 and 2016 due to high relative sea level rise and reduced sediment input from the Mississippi River (MR). The 2023 Louisiana Coastal Master Plan aims to restore Louisiana's degraded coastline through restoration projects, including sediment diversions. The Mid-Barataria Sediment Diversion project will reconnect MR sediment-laden water with Barataria Basin degrading marshes. The diversion will also deliver nitrate (NO₃^-) and soluble reactive phosphorus (SRP) to this basin, potentially negatively impacting water quality. …

Characteristics Of Yogurt And Culture Bacteria As Affected By Ingredients That Help Treat Leaky Gut, Ricardo Jose Santos Aleman

LSU Doctoral Dissertations

At least 100 million people have leaky gut syndrome. This syndrome is associated with multiple health problems such as diabetes, celiac disease, asthma, multiple sclerosis, and inflammatory bowel disease, costing more than $3 billion per year to treat. L-Glutamine, quercetin, slippery elm bark, marshmallow root, N-acetyl-d-glucosamine (NAG), licorice root, maitake mushrooms, and zinc orotate have been reported to help treat leaky gut.

The objectives were to explore the characteristics of yogurt and culture bacteria as affected by ingredients that help treat leaky gut. In yogurt, the pH, titratable acidity, syneresis, viscosity, color, Streptococcus thermophilus, Lactobacillus bulgaricus, yeast and mold and …

Tracing Energy Pathways Through Coastal Wetland Food Webs, Katherine Loesser

LSU Master's Theses

Southeastern Louisiana’s coastal wetlands are important habitat for aquatic species, yet the spatial heterogeneity in habitat types and abundance of many basal energy sources makes it challenging to elucidate patterns of energy flow across the landscape mosaic. This ecosystem is experiencing substantial changes, both through anthropogenically-accelerated climate change and anthropogenic landscape modifications. Therefore, the overall goal of this thesis was to trace patterns of energy flow across coastal wetland landscapes to determine which basal energy pathways support aquatic food webs and if patterns of energy pathway dependence are altered by changes to the landscape. In the first part of this …

Silica Concentrations In Dominant Vegetation Species Of Wax Lake Delta, Louisiana, Danielle M. Soileau

LSU Master's Theses

Coastal deltaic wetlands colonize dynamic environments and experience fluctuations of salinity, river connectivity, sediment dredging or deposition, and periods of inundation resulting in unique vegetation and soils. Louisiana’s coastline is experiencing enhanced loss of coastal deltaic wetlands in coastal basins where the Mississippi River no longer is connected to waterways and channels that would normally provide freshwater and sediments representing the abandonment phase of the delta cycle. There is a coastal basin in the central regions of the state, the Atchafalaya Bay, that is still in the active phase of delta cycle resulting in the growth of the Wax Lake, …

Ecology Of Viruses In Marine And Coastal Oxygen-Depleted Waters, Sophie Jurgensen

LSU Doctoral Dissertations

Deoxygenation of marine and coastal waters, both caused and exacerbated by a suite of abiotic and biotic factors, has been documented for more than sixty years. The incidence and severity of low-oxygen areas is predicted to expand globally in the coming decades. Despite their colloquial moniker “dead zones,” low-oxygen areas contain thriving and diverse microorganisms that have significant impacts on global biogeochemical cycles including contributing to positive feedback loops that further expand low-oxygen areas. While the diversity and activity of these microorganisms is beginning to be elucidated, the ecology of their viruses is particularly understudied. In this dissertation, I present …

The Effectiveness Of Eye-Hand Coordination Training In Virtual Reality, Kelley Burger

LSU Doctoral Dissertations

Virtual environments (VE) and virtual reality (VR) through head-mounted displays (HMD) have been used to test and train eye-hand coordination skills in a way that is more immersive than traditional 2D video training. As this technology continues to evolve, researchers have sought to determine the degree to which these new technologies can augment training. This research attempts to expand the literature on sport skill training in VE and VR to elucidate the training protocols that support learning. The first study was designed to determine how a single session of occlusion training would affect football catching skills in VR. While adding …

Active Transportation, Context, And Community Participation: Engaged Citizens And Destination-Based Walking And Biking, Jessica Stroope

LSU Doctoral Dissertations

Active transportation is associated with many benefits, including improved health outcomes, higher commuting satisfaction, lower pollution, reduced traffic, and social capital. One understudied area of research on active transportation and social capital is the relationship between active transportation and community participation. Although prior work has established a connection, little is known about the contexts in which this relationship may occur, or about how active transportation may affect the relationship between a context and community participation.

The purpose of Chapter 3 is to examine how active transportation may mediate the relationship between perceptions of place and community participation. Significant work has …

Measuring Food Literacy Among Limited-Resourced Adults, Emelia Clement

LSU Doctoral Dissertations

Food literacy is the interrelated knowledge, skills and behaviors needed to plan and manage, select, prepare, and eat healthy food. It is positively associated with improved consumption of nutritious diets, and can be beneficial to limited-resource adults, who are often at risk for chronic diet-related diseases. Valid instruments for measuring food literacy in this population are scarce but urgently needed. The Eating and Food Literacy Behavior Questionnaire (EFLBQ) can be used to measure food literacy among limited-resource audiences.

Part one of this study aimed to determine the fitness of the EFLBQ to measure food literacy in limited-resource adults. A convenience …

Evaluating Abiotic And Biotic Factors Affecting Plant Succession Processes At Malheur Lake, Beth Boos, Sammy L. King

LSU Master's Theses

Arid wetlands are diverse systems that provide habitat for a variety of flora and fauna, including stopover and breeding habitat for migratory birds. In the western United States, these wetlands support a network of stopover sites on the Pacific Flyway, and due primarily to wetland loss and alterations, these areas are becoming more isolated. Malheur Lake is a shallow endorheic lake in eastern Oregon that supported a robust emergent marsh throughout most of the 20^th century. However, following large scale flooding in the 1980s, emergent vegetation was extirpated and has only reestablished in small patches. Our objective was to …

Integrating Germplasm Repositories Into Oyster Aquaculture Systems At The Pathway, Center, And Network Levels, Sarah R. Bodenstein

LSU Doctoral Dissertations

Germplasm repositories offer many potential benefits to commercial farm operations, including preserving genetic resources and increasing production capabilities. Aquaculture industries have yet to take advantage of repository storage despite decades of research evaluating cryopreservation protocols. Eastern oysters (Crassostrea virginica), for example, are a useful research species when addressing this problem. Oysters are an economically important aquaculture species and a high-throughput cryopreservation method for oysters already exists. To address the gap between protocol research and commercial application a different approach is necessary that can analyze the requirements of repository development at multiple organizational levels. The goal of this dissertation was to …

Functional Domains Of The Hsv-1 Ul37 Protein In Virus Infectivity And Retrograde Transport In Neurons, Carolyn Clark

LSU Doctoral Dissertations

Herpes simplex virus type 1 is large alphaherpesvirus with 20 envelope proteins and 23 tegument proteins. Virus entry is via fusion of the viral envelope with cellular membranes mediated by a complex of viral glycoproteins. Glycoprotein B (gB) is the only fusogenic glycoprotein, while other viral glycoproteins and membrane proteins including gD, gH, gL, gK and UL20 membrane protein modulate gB’s fusogenicity. Previously, Our laboratory developed the HSV-1 (VC2) vaccines strain with partial deletions in the amino termini of gK (ΔgK(31–68)) and the UL20 membrane protein (ΔUL20(4–22)). VC2 enters epithelial cells only via endocytosis followed by release of the capsid …

The Characterization Of Selected Α- And Β-Carbonic Anhydrases Of Arabidopsis Thaliana, Hiruni Weerasooriya

LSU Doctoral Dissertations

Carbonic anhydrases (CAs) are zinc-metalloenzymes that interconvert two inorganic carbon (Ci) species, CO₂ and HCO₃^-. In Arabidopsis thaliana, there are eight αCA genes, six βCA genes, three γCA genes, and two γCA-like genes. The majority of CA research in plants has focused on finding a link between CA activity and photosynthesis rates. Since the CA genes are expressed in different plant tissues and multiple CA isoforms are distributed among various organelles of the plant cell, I hypothesize that CAs facilitate CO₂ diffusion among cell compartments and maintain Ci pools for carbon-requiring reactions by interconverting …

Influence Of Metabolic Interventions On Animal Aging And Lifespan, Bhaswati Ghosh

LSU Doctoral Dissertations

Aging is associated with metabolic rewiring. Most lifespan-extending longevity interventions target metabolic pathways. Genetic or pharmacological metabolic approaches that mediate longer lifespan and healthspan, are often linked to detrimental effects on human health. Here, I show that supplementation of botanical extracts from Artemisia scoparia (SCO), dramatically increases animal lifespan. Mechanistically, this lifespan extension is dependent on AMPK-DAF-16 signaling via inhibition of the insulin pathway. In SCO-fed worms, longer lifespan was accompanied by higher fat storage and improved resiliency to age-related physiological stress. Notably, DAF-16, the master regulator of longevity, activated the fatty acid desaturation processes, which promoted the accumulation of …

Evaluation Of Reproductive Phenology, Space Use, And Ecology Of The Eastern Wild Turkey (Meleagris Gallopavo Silvestris) In West-Central Louisiana, Chad Argabright

LSU Master's Theses

Nest site selection is a driving demographic force behind eastern wild turkey (Meleagris gallopavo silvestris) populations. However, previous research was likely not focused on the actual time of nest site selection, considering that nest site selection is likely only able to occur on the day of the first egg being laid. My objective was to determine if selection for any vegetation characteristics was occurring on the first day of laying. I estimated the path taken from the roost to the nest on the first day of egg laying (i.e., laying path) using GPS data collected from 164 unique …

Evaluating The Pesticide-Induced Outbreak Of Soybean Looper, Chrysodeixis Includens (Walker) (Lepidoptera: Noctuidae), In Louisiana Soybean, Scott Lee

LSU Doctoral Dissertations

Soybean looper, Chrysodeixis includens (Walker), has established itself as the primary lepidopteran defoliator in Midsouth soybean agroecosystems. Pesticide-induced outbreak events associated with this pest have been observed by soybean producers. The insecticides believed to prompt these incidents are routinely used for the control of other co-occuring pests, such as stink bugs. Outbreak conditions present soybean producers with conflicting management decisions for pests. Laboratory, greenhouse, and field experiments were conducted to provide a better understanding of insecticide usage impact on populations of C. includens and the arthropod community. To discern the potential mechanisms behind C. includens outbreak, a baseline for the …

Characterizing Marr Homologs That Mediate Bacterial Fitness And Survival, George Chukwuemeka Nwokocha

LSU Doctoral Dissertations

Plant disease outbreaks are on the rise, threatening food security in many parts of the globe. To address these enormous challenges, new intervention strategies like bio-controls are being used as an important sustainable alternative to mitigate the negative effects of pathogens and increase the quality and productivity of agricultural crops. MarR family transcriptional regulators have been studied for their involvement in regulating bacterial virulence genes that help colonize plant hosts and therefore could serve as targets for biocontrol. The transcriptional regulator PecS, a member of the MarR family, is encoded by select bacterial pathogens and we show here that PecS …

The Global Transcription Factor Fur Is Activated By Binding A [2fe-2s] Cluster To Maintain Iron Homeostasis In Escherichia Coli, Chelsey Rene Fontenot

LSU Doctoral Dissertations

Iron is an essential element for biological functions. Organisms have developed specific mechanisms to acquire, store, and export iron to manage intracellular iron homeostasis. These mechanisms are crucial not only for providing the cells with adequate iron for biological processes but also for ensuring that cells are not overloaded with excess iron, which is highly toxic. The Ferric uptake regulator (Fur) is a global transcription factor for maintaining intracellular iron homeostasis in bacteria. Previously, it was postulated that when the intracellular iron content is elevated, Fur binds ferrous iron to down-regulate the iron acquisition genes and up- regulate the iron …

The Regulation Of Autoimmunity Genes In Pancreatic Β-Cells By Nf-Κb, Thomas Malone Martin

LSU Doctoral Dissertations

Type 1 diabetes (T1D) is an autoimmune disease where the immune system targets the pancreatic islet beta-cells, which are responsible for insulin production and secretion, leading to a state of insulin insufficiency. Many of the molecular details of disease onset and progression remain poorly understood, including key aspects of cytokine signaling. Therefore, we have examined some of the consequences of inflammatory cytokine signaling as a critical module relevant to T1D. Using interleukin-1 (IL-1) signaling as a well-defined paradigm for inflammation, we investigated key components of this signaling pathway in pancreatic beta-cells. We identified ICAM-1, one of the proteins expressed in …

Evaluating Form And Function Of Groundcovers And Their Environmental Impacts In Louisiana Landscapes, Thomas Maxwell Mckeown

LSU Master's Theses

Increasing environmental concerns are encouraging the adoption of sustainable landscapes that have environmental, social, and financial benefits. Ornamental groundcover systems are touted as sustainable landscape features due to the associated decreased demand of water, fertilizer, pesticide, and maintenance; however, limited research exists on soil property effects, planting density, weed density, or consumer preferences of groundcovers. This study was aimed to gain a more thorough understanding of ornamental groundcovers systems and their environmental impacts. The effects of groundcover growth habit (matting; bunching) and irrigation delivery (micro spray; overhead) on soil temperature, volumetric water content (VWC), and electric conductivity (EC) along with …

Gulf Sturgeon Mesohabitat Use And Movement In The Lower Pearl River Louisiana-Mississippi, Amanda Popovich

LSU Master's Theses

After spring migrations to natal rivers Gulf Sturgeon Acipenser oxyrinchus desotoi reside in freshwater holding areas prior to fall emigrations to nearby estuaries. Limited published information on the physical habitat characteristics of these holding areas is available, especially for juvenile fish in the western portion of the Gulf Sturgeon’s distribution. To further investigate freshwater occupancy and movement patterns, 32 acoustic receivers were deployed from late April to October of 2021 and 2022 in 1600-m reaches distributed throughout the lower Pearl River, Louisiana-Mississippi, the westernmost river within their distribution. Generalized linear mixed models and multi-state models were used to determine what …

Attentional Focus Effects On Motor Variability, Charlend Kenneth Howard

LSU Doctoral Dissertations

Subtle changes in task instructions with associated changes of one’s focus of attention (FOA) can have measurable effects on performance and learning of complex motor skills (Wulf, 2013). The beneficial effects of adopting an external focus of attention (EF) have been well-documented in physical environments, and recently have also been demonstrated in virtual reality (VR) environments (Cochran, Aiken, Rhea, & Raisbeck, 2021; Yamada, Kuznetsov, Diekfuss, & Raisbeck, 2021). However, these studies primarily focused on performance outcomes (such as error and accuracy), with relatively less emphasis on movement coordination. Given that most human movements are motor abundant (more degrees of freedom …

Svip Dependent Tubular Lysosomal Restoration: A New Direction In Vcp Diseases, Ankita Basu

LSU Doctoral Dissertations

Multisystem Proteinopathy-1 (MSP-1) is a rare, autosomal dominant, degenerative disease resulting from single amino acid mis-sense mutations in the AAA+ ATPase, Valosin containing protein (VCP). Patients with VCP mutations vary widely in their pathology and clinical penetrance, making it difficult to devise effective treatment strategies. To investigate the pathology of VCP- related disease, we engineered CRISPR knock-in Drosophila models for nine MSP-1 associated VCP mutations. These mutant animals mimic human MSP-1 disease phenotypes, including progressive mobility decline and accumulation of protein aggregates, making them excellent models to study the pathology of VCP associated mutations and test potential treatment strategies. At …

Louisiana Agriculture Magazine, Spring 2023

Louisiana Agriculture

In this issue of Louisiana Agriculture, Carl Motsenbocker, the executive director of Seeds to Success, and Crystal Besse, the program director, explain how local food systems are seeing a resurgence. The Seeds to Success team details how the farm to school movement is assisting this growth. They also profile the people who work to make it possible — a teacher, farmers and an AgCenter Extension agent. In additional articles, researchers examine the economic benefits of farm to school programs as well as soil mixes for home gardeners and the media used by our consumer horticulture industry.

Louisiana Resident Perceptions On Invasive Aquatic Plant Species And Their Management, Anna Ribbeck

LSU Master's Theses

Determining the public perception of invasive species in Louisiana is an important tool to help shape and develop future management decisions, educational material and ultimately public policy. Therefore, the primary purpose of this study was to determine the perceptions of adult Louisiana residents regarding invasive aquatic plant species and their management. An online survey was used to collect data on registered Louisiana residential boaters’ perceptions towards invasive aquatic plants and their management. A postcard with a quick response code leading to the survey was mailed to 6,000 randomly selected Louisiana registered residential boaters. Of the 230 Louisiana registered boaters that …