Life Sciences Commons^™

Juul 3% Menthol Aerosol Extracts Exhibit Toxicity And Alter Gene Expression Of Murine Macrophages, Samantha Jindia

Honors Capstones

No abstract provided.

Analysis Of Young, Lineage Specific Alu Elements In Cebus, Catherine Rockwell

Honors Capstones

No abstract provided.

Investigating Plant Tolerance For The Management Of Insect Pests In Rice, James Michael Villegas

LSU Doctoral Dissertations

The rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), is the most destructive and widespread insect pest of rice (Oryza sativa L., Poaceae) in the USA. This insect poses a global threat to rice production, having invaded rice-producing regions of Asia and Europe. Moreover, lepidopteran stemborers, particularly the invasive Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), are increasingly becoming problematic in Louisiana rice. Although insecticidal seed treatments have been widely used against weevils and stemborers, alternative management strategies are needed. Plants possess defense-related traits that both reduce injury from herbivores (resistance) and the amount of yield loss per …

Historical Dna Solves An Evolutionary Mystery And Explains The Origin Of A Novel Phenotype In The New World Quails, Jessie Frances Salter

LSU Doctoral Dissertations

Observations of phenotypic diversity among closely-related organisms, especially those preserved as museum specimens, have driven the fields of systematics, taxonomy, and evolutionary biology for hundreds of years. In this dissertation, I used genomic data from modern and historical specimens to investigate the evolutionary processes that have generated phenotypic and genetic diversity in a highly polytypic group of birds, the New World quails (Odontophoridae), with a focus on the most phenotypically diverse member of this family: Northern Bobwhites (Colinus virginianus). To facilitate this work, I began by generating a highly contiguous reference genome assembly for Northern Bobwhites, which is …

Assessment Of Cash Value Benefits And The Effects On Participant Vegetable Consumption In The Louisiana Wic Program, Celia Rene Bridgeforth

LSU Doctoral Dissertations

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is administered by the United States Department of Agriculture (USDA) Food and Nutrition Service (FNS). The WIC program serves low-income women, infants, and children by providing supplemental foods, nutrition education, breastfeeding support and promotion, and referrals to healthcare and social service programs (Oliveira & Frazão, 2015). Revisions of the WIC food packages to include cash value benefits (CVB) that provided WIC participants the opportunity to purchase fruits and vegetables with their WIC benefits. There is significant research that indicates the benefit of F.V. consumption and the impact on diet-related …

Integrated Nutrient Management And Cover Cropping Practices In Louisiana Sugarcane Production Systems, Daniel Erneso Forestieri

LSU Doctoral Dissertations

Integrating effective fertilizer management with conservation practices is essential to improve farm income and promote environment friendly sugarcane production systems. A study was conducted in multiple to document the impact of nitrogen (N) source and cover cropping on sugarcane yield and quality components. The treatment consisted of different N sources: urea, knife-in urea ammonium nitrate (UAN) solution, calcium nitrate-CaNO3, ammonium sulfate-NH4SO4, and knife-in UAN. + foliar N, applied at 90 kg ha-1 and control (0 N). The cover crops included: crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa), and oilseed radish (Raphanus sativus L.) planted at 13, 17, and 1 …

Louisiana Agriculture Fall, 2021, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

A Modular Open-Technology Device To Measure And Adjust Concentration Of Sperm Samples For Cryopreservation, Nikolas C. Zuchowicz

LSU Master's Theses

Repositories for aquatic germplasm can safeguard the genetic diversity of species of interest to aquaculture, research, and conservation. The development of such repositories is impeded by a lack of standardization both within laboratories and across the research community. Protocols for cryopreservation are often developed ad hoc and without close attention to variables, such as sperm concentration, that strongly affect the success and consistency of cryopreservation. The wide dissemination and use of specialized tools and devices can improve processing reliability, provide data logging, produce custom hardware to address unique problems, and save costs, time, and labor. The goal of the present …

Blue Carbon In South Florida's Mangroves: The Role Of Large Roots And Necromass, Zoë I. Shribman

LSU Master's Theses

Blue carbon sequestration and storage in mangroves largely result from belowground biomass allocation in response to flooded anaerobic soil conditions and nutrient availability. Biomass allocation to belowground roots is a major driver of mangrove soil formation and organic matter accumulation leading to blue carbon storage potential. Belowground biomass sampling in mangroves is labor intensive, limiting data availability on biomass stocks, particularly for large roots (>20 mm diameter) and necromass (dead roots). The mangrove nutrient model (NUMAN) uses mostly literature values to parameterize a soil cohort approach to simulate depth distribution of root mass and organic carbon concentration. We evaluated …

Resistance Allele Frequencies To Cry1ab And Vip3aa20, And Performance Of Cry1a.105/Cry2ab2 Susceptible And Single/Dual-Gene Resistant Corn Earworm On Non-Bt And Low Concentrations Of Bt Diet, Shucong Lin

LSU Master's Theses

Corn earworm, Helicoverpa zea (Boddie), is an important agricultural pest and a target species of Bt corn and Bt cotton. Recently, this pest in the U.S. has developed resistance to Cry1/Cry2 corn and cotton. The objectives of this study were to 1) estimate the frequencies of resistance allele to Cry1Ab and Vip3Aa20 proteins in Louisiana populations of H. zea; 2) determine if Cry1A.105/Cry2Ab2 single/dual-gene resistance in H. zea is associated with fitness costs; and 3) investigate the effect of three low concentrations of mixed Cry1A.105/Cry2Ab2 proteins on the growth, development, and reproduction of two known Bt-susceptible strains and six …

Influence Of Planting Date, Maturity Group, Harvest Aids And Fungicide Application On Soybean (Glycine Max (L.) Seed Quality, Ana Priscila Campos

LSU Master's Theses

Field studies evaluated the influence of planting date, maturity group, and harvest timing on soybean yield and seed quality at the LSU AgCenter Northeast (NERS), Macon Ridge, and Dean Lee Research Stations in 2018-2020. In addition, the influence of harvest aid and fungicide application on seed quality impact from delayed harvest and environment was investigated at NERS in 2019 and 2020 in both field and environmentally controlled growth chambers. Soybean yield was maximized when maturity group IV and V soybean varieties were planted between Mid-April and Mid-May. Earlier and later planting dates did not result in maximized yield. Planting date …

Understanding The Etiology Of Taproot Decline Of Soybean Caused By Xylaria Necrophora, José E. Ortiz Solórzano

LSU Master's Theses

Taproot decline (TRD) of soybean is caused by Xylaria necrophora. However, the mechanisms by which it infects soybean and produces symptoms are unknown. Symptoms of TRD include foliar interveinal chlorosis and necrosis and root necrosis, yet X. necrophora appears to be restricted to the roots. While Xylaria species are predominantly wood decomposers, a few are pathogens. More importantly, they produce secondary metabolites (SMs) with multiple bioactivities, including phytotoxicity and antimicrobial activity. Preliminary experiments suggested that X. necrophora was producing SMs responsible for TRD symptoms. We evaluated cell-free culture filtrates (CFs) for phytotoxicity on soybeans, testing for changes in chlorophyll …

Population Structure In Two Imperiled Sparrows With Differing Vagility, Amie Elizabeth Settlecowski

LSU Doctoral Dissertations

Characterizing population structure and genetic differentiation can inform the management of imperiled species and the relative influences of ecological and evolutionary factors on species evolution. One trait that is expected to influence the amount of population structure a species exhibits is vagility, or the ability to move across the landscape. Species with higher vagility may be more likely to disperse, potentially facilitating gene flow among populations and limiting population structure. My dissertation focuses on characterizing population structure in 2 imperiled sparrows that are both largely nonmigratory with broad distributions in eastern North America: Seaside Sparrow (Ammospiza maritima) and Bachman’s Sparrow …

Gene (Co)Expression Networks And Alternate Transcripts Induced In Cotton In Response To Aspergillus Flavus Infection, Mohit Verma

LSU Doctoral Dissertations

Cotton (Gossypium hirsutum L) is an economically important crop that generates billions of dollars in annual revenue worldwide. However, contamination of cottonseed with a highly carcinogenic aflatoxin produced by Aspergillus flavus limits the use of cottonseed in the oil and animal feed industries. Much success has been achieved by the application of atoxigenic strains of A. flavus for controlling aflatoxin contamination in cotton, peanut, and maize. Understanding the gene (co)expression network in response to A. flavus infection with both toxigenic and atoxigenic strains of A. flavus pericarp and seed of cotton through genome-wide transcriptome profiling will not only unravel …

Indicators Of Senescence And Their Relationship With The Antioxidant Response Element In Ovarian Cancer Cells—Toward A More Encompassing View Of Enzyme Activity Levels In Cells, Shaniqua Analycia Hayes

LSU Doctoral Dissertations

Enzymes and other related proteins are promising targets as biomarkers for cancer diagnostics, and it is therefore important to be able to quantify intracellular enzyme activity levels, not just presence of enzyme. Thus, there is a great need for the development of methods that offer spatiotemporal quantification of intracellular enzyme activity levels in respiring 2- and 3-dimensional cultures or their sample-processed variants. Previous studies have demonstrated that ß-gal is upregulated in senescence and in select ovarian cancers, and its expression/activity is upregulated when cells are under oxidative stress conditions. To that end, the primary goal of this work was to …

Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith

LSU Doctoral Dissertations

At the end of the Cretaceous Period, a large bolide impacted the Earth and formed the Chicxulub impact crater in the Yucatán Peninsula, Mexico. In 2016, International Ocean Discovery Program (IODP) Expedition 364 Site M0077 drilled into the buried peak ring of the crater, recovering a marine Paleocene to early Eocene post-impact section deposited on top of the impact breccia. Palynological analysis of 195 samples from the post-impact section has yielded the first pre-Holocene vegetational record from inside the Chicxulub impact crater and the first palynological record of the recovery of life following the end-Cretaceous mass extinction from inside the …

Gain-Of-Function Polymorphisms In Human Inflammasomes: Implications For Cystic Fibrosis, Duane Jeansonne, Samithamby Jeyaseelan

Faculty Publications

No abstract provided.

Phragmites Australis Dieback In The Mississippi River Delta: Chemical Profiles Of Soil Types And Restoration Potential, Herie Lee

LSU Master's Theses

Since 2016, there has been widespread dieback of P. australis in the Lower Mississippi River Delta (hereafter referred to as Lower MRD, which is defined as the Birds Foot Delta) with relatively little to no signs of recovery. The cause of the current dieback is not fully understood. This thesis explores P. australis with emphasis on chemical profile characterization of different soil types and its effects on plant growth and the potential for restoration in the Lower MRD.

In chapter 2, I characterized the chemical profiles of soils collected from healthy and dieback stands of Phragmites, and from newly …

Determinants Of Fine-Scale Heterogeneity In Mosquito-Borne Virus Systems, Elizabeth Handly Mayton

LSU Doctoral Dissertations

ABSTRACT

Arthropod-borne viruses (arboviruses) are the etiological agents of much morbidity and mortality, especially in low- and middle-income countries. Many of these viruses are spread and maintained by mosquitoes, particularly the urban mosquito Aedes aegypti. Zika virus (ZIKV) is responsible for one of the largest vector-borne disease outbreaks in the past decade, affecting millions in Central and South America including a wave of microcephaly among newborns. Mayaro virus (MAYV) is a mosquito-borne virus endemic to South America and is predicted to become an emergent public health threat. Describing the vector-virus transmission systems are critical for understanding the potential spread …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Investigating Local Adaptation To Hypoxia Stress In The Eastern Oyster Through Comparative Transcriptomics, Heather Nichole Smith

LSU Master's Theses

Climate change represents one of the most important challenges to biodiversity, therefore it is important to understand the mechanisms that allow species to respond to rapid environmental change. Here, we compared two populations of eastern oysters, Crassostrea virginica, from the Gulf of Mexico to study the mechanisms underlying hypoxia tolerance. Using a common garden experiment and comparative transcriptomics, we identified sets of genes involved in the hypoxia response and found differences in both the timing and baseline expression of hypoxia-responsive genes between tolerant and sensitive populations, consistent with a scenario of local adaptation. These genes include the signaling transcription factor …

Effects Of Plant Spacing Variability And Non-Uniform Emergence On Corn Yield, Justin Dufour

LSU Master's Theses

Plant spacing variability and non-uniform emergence in corn (Zea mays L.) is not uncommon in Louisiana corn fields. Variation in planting depth, non-uniform surface crop residue distribution in no-tillage systems, microsite variation in the seed bed condition, and seed vigor are major factors responsible for non-uniform emergence. Also, planters with low precision in seed placement and careless planting operations can cause non-uniform spacing. Two studies were conducted to quantify the effects of plant spacing variability and non-uniform emergence on grain yield in corn. Six plant spacing treatments at 47,770 plants ha^-1 were evaluated. Uniform spacing, seed skip, double …

Evaluation Of Cool-Season Annuals Effect On Soil Health In Warm-Season Perennial Pastures In Southestern Us., Paola C. Muela Negrete

LSU Master's Theses

Perennial grass crops represent approximately 8 million hectares of the land area of the humid lower southeastern United States. These forage crops receive high rates of fertilizer, especially nitrogen (N), and near monoculture remains have often been treated with repeated applications of herbicides. Pasture management is crucial to improve soil properties in pasturelands. Common pasture management practices include introducing cool-season multispecies in warm-season pasture systems and forage harvest frequency of pasture systems. It is known that cool-season multispecies in warm-season pasture systems ensure cattle feeding during winter season and have beneficial effects on soil microbial biomass, soil organic matter (SOM), …

The Evolution Of Dietary Adaptations In Small Mammals: From Muscles To Microbes, Mark Thomas Swanson

LSU Doctoral Dissertations

My dissertation provides critical insights on the pattern and process of evolution in front-end and back-end dietary adaptations of mammals. I found that the position of the rodent masseter muscle, a complex front-end adaptation that improves the efficiency of mechanical digestion, has convergently evolved numerous times, suggesting that selective pressure for this adaptation has been strong. For back-end adaptations, I found gut bacterial taxa that likely aid in chemical digestion of food have predictable associations with host diet across host species in natural environments. To detect patterns in gut microbial community structure that are related to host factors such as …

Neuromuscular Control Strategy During Object Transport While Walking: Adaptive Integration Of Upper And Lower Limb Movements, Ahyoung Song

LSU Doctoral Dissertations

When carrying an object while walking, a significant challenge for the central nervous system (CNS) is to preserve the object’s stability against the inter-segmental interaction torques and ground reaction forces. Studies documented several strategies used by the CNS: modulation of grip force (GF), alterations in upper limb kinematics, and gait adaptations. However, the question of how the CNS organizes the multi-segmental joint and muscle coordination patterns to deal with gait-induced perturbations remains poorly understood. This dissertation aimed to explore the neuromuscular control strategy utilized by the CNS to transport an object during walking successfully. Study 1 examined the inter-limb coordination …

Effects Of Wetland Management And Associated Abiotic Factors On Rare Plant Communities Of Spring-Fed Arid Wetlands, Antonio Cantu De Leija

LSU Master's Theses

Spring-fed arid wetlands support high biological productivity and are hotspots for endemism and distribution of rare plants, making them areas of high conservation value. These systems are driven by complex interactions among groundwater discharge and the geomorphic and climatic features of the setting, which provide gradients of edaphic conditions, particularly soil moisture and salinity that influence the presence and abundance of rare plant communities. However, spring-fed arid wetlands are at particular risk of increases in salinity and drier hydrological regimes due to anthropogenic activities. Such alterations to abiotic conditions may jeopardize the distribution and abundance of rare plants by exceeding …

Optimization Of Mechanical Properties At The Infarct Border Zone, Kaushik Sunder

LSU Master's Theses

A myocardial infarction (MI) occurs every 39 seconds in the United States. As of 2016, an estimated 550,000 new and 200,000 recurrent episodes of myocardial infarction (MI) occur each year in the United States was. Infarction is often distinguished by a considerable decrease in wall thickness and an increase in heart size or left ventricular volume. This behavior happens when there is a prolonged lack of blood flow, usually due to damage or clotting, which causes cardiomyocytes to die (CMs). The development of non-contractile infarct scarring is the primary pathophysiology of MI. While the infarct scar prevents myocardial rupture during …

Understanding Potassium Toxicity Stress Responses Of The Extremophyte Schrenkiella Parvula Using Systems Biology Approaches, Pramod Pantha

LSU Doctoral Dissertations

Schrenkiella parvula is an extremophyte model closely related to Arabidopsis thaliana and Brassica crops. Its natural habitat includes shores of saline lakes in the Irano-Turanian region. It has adapted to grow in soils rich in multiple salts including Na⁺ and K⁺. I have investigated the genetic basis for high K⁺ tolerance in plants using S. parvula as a stress tolerant model compared to the premier plant model, Arabidopsis thaliana which is highly sensitive to salt stresses using physiological, ionomic, transcriptomic, and metabolomic approaches. Under high K⁺ stress, root system architecture changes significantly compared to control …

Seasonal Variation In The Feeding Ecology Of Yellowfin Tuna (Thunnus Albacares) From The Northern Gulf Of Mexico, Mitchell Shay Lovell

LSU Master's Theses

Highly migratory fishes (e.g., tunas, billfishes, and sharks) play a significant role in the structure and function of open-ocean ecosystems and a better understanding of the food web dynamics that support their populations is essential to improve management and conservation. Here, I use complementary approaches (stomach contents, DNA barcoding, & stable isotopes) to examine seasonal variability in the feeding ecology of sub-adult (70 – 100 cm; n = 371) and adult (100 – 160 cm; n = 206) yellowfin tuna (Thunnus albacares) from the northern Gulf of Mexico over a one-year period (April 2019 – March 2020). Stomach …

Late Embryogenesis Abundant Proteins And Mitochondrial Membranes From An Animal Extremophile: Insights Into Severe Water Stress, John Marcus Anderson

LSU Doctoral Dissertations

This dissertation focuses on two major topics germane to mechanisms by which animals tolerate extreme water stress. First, the impact of transgenic expression of late embryogenesis abundant proteins (LEA) on water stress tolerance of the fruit fly Drosophila melanogaster was investigated. The overall aim was to extend current understanding of the protective properties of LEA proteins documented with isolated cells to a desiccation-sensitive organism during exposure to drying and hyperosmotic stress. Four lines of D. melanogaster were created that expressed transgenes encoding selected LEA proteins originally identified in embryos of the extremophile Artemia franciscana. After 80% tissue water loss, …