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Determining The 3d Structure And Dynamics Of Mouse Notch1 Epidermal Growth Factor-Like Repeat 26 Using Nuclear Magnetic Resonance Spectroscopy, Kendra D. Jenkins

LSU Doctoral Dissertations

NOTCH is a transmembrane protein that transmits signals between cells in direct contact and alters gene expression. The signaling pathway is important because it is involved in cell fate determination. The NOTCH1 extracellular domain has 36 epidermal growth factor-like (EGF) repeats that are responsible for ligand binding. Mutations in the EGF-like repeats cause various neurological and developmental disorders. NOTCH1 signaling initiates when DSL ligands bind to EGF11-12, the minimum Ligand Binding Domain (LBD). The Abruptex region of the NOTCH1 protein (EGF24-29) is a highly glycosylated, flexible region with calcium binding sites that regulates NOTCH1 signaling and binding by interacting with …

Identifying The Components Of A Hemp (Cannabis Sativa L.) (Rosales: Cannabaceae) Integrated Pest Management Program In Louisiana, Nathan C. Arey

LSU Master's Theses

Hemp, Cannabis sativa (L.) (Rosales: Cannabaceae), is defined as a plant in the genus Cannabis with a delta-9 3 tetrahydrocannabinol (THC) concentration of not more than 0.3% on a dry weight basis. Domestic acreage of this crop has increased in response to the ratification of the Agricultural Act of 2014 and the Agricultural Improvement Act of 2018. In 2021, 21,915 hectares of hemp were planted in the United States with a production value of $712 million. There is a current lack of literature on insect related research in this reemerging crop system in the state of Louisiana. Therefore, this present …

Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete

LSU Doctoral Dissertations

The world’s dependence on petroleum hydrocarbons has led to significant environmental implications. For example, oil spills cause lasting environmental damage, and the increase of plastics in the marine environment has been growing, specifically, microplastics that can be difficult to detect due to their small size. Petroleum hydrocarbons occur naturally in nearly all marine environments, which has allowed hundreds of microorganisms to evolve to utilize these hydrocarbons as their primary energy source. These microbes are classified as hydrocarbonoclastic and are utilized to remove spilled oil biodegradation. Over the last ten years, progress has been made in the biodegradation of oil spills …

Electrochemical Reduction Of Hexavalent Chromium On Glassy Carbon Electrodes In Acidic Buffers, Callie M. Stern

LSU Doctoral Dissertations

As fresh water systems become endangered due the expansion of growth and human civilization, it is important to find effective water purification strategies. A common water contaminant that is mostly generated through industrial processes is hexavalent chromium. The two stable forms of chromium found in aqueous systems are hexavalent chromium, Cr(VI), and trivalent chromium, Cr(III). Considered an essential nutrient, Cr(III) is non-toxic to humans. Cr(VI) on the other hand, is toxic at low concentrations and can be ingested through drinking contaminated water. There is no standard limit to the amount of Cr(VI) that can be in drinking water and most …

Evolution Of Freshwater Fishes In The Northern Neotropics, Diego Elias

LSU Doctoral Dissertations

The northern Neotropics (NN) represents one of the most geologically-complex regions on the planet, composed of island-like geological blocks that have undergone multiple episodes of isolation and connectivity at various geological times. The riverscapes of the NN harbor a unique assemblage of freshwater fishes. In contrast to the freshwaters systems of South America, which are dominated by ostariophysan lineages, the aquatic systems of the NN are dominated by lineages of two families: Cichlidae (cichlids) and Poeciliidae (livebearers). It has been suggested that the geologically complex nature of the region allowed ancestors of cichlids and livebearers to colonize and radiate within …

Developmental Competence Of Oocytes Derived From Seasonally Anovulatory Mares Treated With Estradiol And Sulpiride, Michelle O. Vetter

LSU Master's Theses

Over the course of two years (2021-2022), two experiments were conducted during the nonbreeding seasons to evaluate the in vitro developmental potential of oocytes derived from seasonally anovulatory mares treated with ECP-sulpiride. The objective of experiments 1 and 2 were to compare pooled recovery and maturation rates of oocytes from mares treated with estradiol cypionate (ECP) and sulpiride with oocytes collected from naturally transitional mares (controls). Cleavage rates of oocytes subjected to intracytoplasmic sperm injection (ICSI) were compared only in experiment 2. In experiments 1 and 2, a total of 36 light horse and pony-cross anovulatory mares were used. Treatment …

Evaluation Of Residual Antibacterial Effects On Canine Skin Surface And Hairs Following Treatment With Five Commercial Mousse Products Against Staphylococcus Pseudintermedius In Vitro, Chi-Yen Wu

LSU Master's Theses

Topical products are essential treatments for canine superficial bacterial folliculitis. However, studies for commercial products typically evaluate antibacterial effects on hairs rather than the skin surface. In addition, the interference from the hair length has not been evaluated in these studies. Therefore, the study objective for this study was to evaluate the residual antibacterial effects of five mousse products, (1) 2% chlorhexidine and 2% miconazole, (2) 0.05% phytosphingosine, (3) 2% salicylic acid and 10% ethyl lactate, (4) 3% chlorhexidine and 0.5% climbazole, and (5) 2% chlorhexidine and 1% ketoconazole on both the skin surface and hairs in both short- and …

Understanding The Horse Fly Species And Species Relations Of The Tabanus Nigrovittatus Complex Along Coastal Louisiana, Darrius M. Davis

LSU Master's Theses

The Dipteran family Tabanidae is among the most diverse families of insects that is comprised of approximately 144 genera with 4455 described species (Pape et al. 2011). Members of the family Tabanidae have been studied for well over 100 years in Louisiana. Hine (1906, 1907) conducted the first surveys of the members of the tabanid family and noted the presence of 14 species. Jones and Bradley (1923) supplemented Hine’s observations with their own inventory of horse flies across four parishes and found an additional 14 species that were not recorded by Hine. Subsequently, Tidwell (1970, 1973) conducted a survey of …

Impact Of Oil And A Tropical Cyclone On An Omnivore And Herbivore Population In Salt Marshes Of Louisiana, Hannah K. Gordon

LSU Master's Theses

Terrestrial arthropods are the ideal ecological indicators for the health of a salt marsh. Salt marshes are under extreme continuous stressors including climate change, land loss, oil spills, and tropical cyclones. Such stressors impact trophic and species level interactions, food resources, dispersal and population size of insects. In the present study, we collected terrestrial arthropods from eleven sites around Barataria Bay, five sites were oiled and five sites were unoiled, to determine the impact of the redistribution of oil from the Deepwater Horizon oil spill. Site C6 was excluded from the oiled and unoiled data because it was in close …

Screening Soybean Cultivars For Resistance To Aerial Blight Caused By Rhizoctonia Solani Ag1-Ia, Kensy D. Rodriguez-Herrera

LSU Master's Theses

Aerial blight, caused by the fungus Rhizoctonia solani AG1-IA, is an economically important soybean disease in the mid-South. The same pathogen also infects other crops commonly rotated with soybeans like rice, corn, and grain sorghum. Rhizoctonia solani AG1-IA is difficult to manage because of its soilborne nature and the production of long-term survival structures, sclerotia. Management has relied on fungicide applications during the season. Still, there is an increasing prevalence of resistance to commonly used strobilurin fungicides and an urgent need to identify soybean cultivars resistant to aerial blight. Since the patchy distribution of the pathogen complicates field cultivar screening, …

Does Well-Being Moderate The Association Of Harm Avoidance With Cognitive Decline, Christopher Reed

LSU Master's Theses

The Dual-Factor Model of mental health highlights the need to consider both constructs associated with psychopathology and subjective well-being in relation to clinical outcomes. Harm avoidance, which is associated with behavioral inhibition, has been negatively associated with cognitive change. While subjective well-being has been positively associated with cognition. The current study aimed to examine both constructs in a single model to examine well-being as a moderator of the association of harm avoidance with cognitive decline. A sample of 728 older adults from the Rush University Memory and Aging Project was used. Participants completed batteries of questionnaires and neuropsychological tests at …

The Relationship Between Family Environment And Specific Phobias, Jerrica Renee Guidry

LSU Doctoral Dissertations

Specific phobias are the most prevalent disorder among adults and highly common among children. Additionally, specific phobias diagnosed in childhood has been associated other serious mental illnesses later in life (de Vrie et al., 2019). Research pertaining to parenting factors associated with anxiety disorders has been extensive, including parental psychopathology, parent-child relationships, parental control, and parental stress. However, less emphasis has been placed on familial factors which may contribute to the development and maintenance of specific phobias. According to the limited literature focusing on the family factors associated with specific phobias, parent psychopathology and parent over-control are important factors. Multiple …

Insights Into The Speciation Process From Genomic And Phenotypic Analysis Of An Avian Hybrid Zone In Amazonia, Glaucia Christina Del-Rio

LSU Doctoral Dissertations

Understanding the outcome of secondary contact is essential to shed light on the mechanisms governing species formation and maintenance. In Amazonia, closely related bird taxa with limited dispersal abilities are often separated by rivers, which presumably act as dispersal barriers. However, at the headwaters, rivers cease to be dispersal barriers, and this generates opportunities for secondary contact. In my dissertation, I studied genomic mechanisms associated with phenotypic differences, mitochondrial DNA structure, and putative reproductive barriers between two hybridizing Amazonian bird species in the genus Rhegmatorhina, a group of antbirds that find their arthropod prey exclusively by following army-ant swarms. …

Cover Cropping: Sensor-Based Estimations Of Biomass Yield And Nutrient Uptake And Its Impact On Sugarcane Productivity, Hector H. Fajardo Duran

LSU Master's Theses

Sugarcane in Louisiana can be harvested for up to three years from one planting. Soil cultivation along sides of established beds is done for weed control and improve fertilizer use efficiency which increases the risk of soil degradation and yield decline. Planting cover crops (CC) is a soil conservation practice and an effective strategy to improve soil health and nutrient recycling. Limited work has been done on remote sensor-based evaluation of the potential nutrient benefits from cover crops and its effect on nutrient cycling on sugarcane systems. This study was conducted to evaluate the effect of two planting methods (broadcast …

Analysis Of Geographic Variability Of Fecal Microbiomes Of Fratercula Arctica And Cross-Comparison Of Fecal Microbiomes Of Different Avian Feeding Types, Eric Jose Ramon Martinez

LSU Master's Theses

Gastrointestinal (gut) microbiota have a multitude of effects on their host, from aiding in digestion, to facilitating nutrient uptake, detoxification, and interactions with the immune system. Multiple factors have been identified that influence the composition of vertebrate microbiomes; these include host genetics, environmental conditions, diet and age, sex, and geography. However, broad inferences about wild avian gut microbial diversity and function under natural conditions are limited. Most knowledge on avian microbiomes is derived from studies on domestic poultry. Information on non-model taxa may provide important contextual information about vertebrate host-microbiome interactions and aid in future management of vulnerable species. Here, …

Micro Heat Exchanger To Cool Cerebrospinal Fluid For Brain Injury Treatment, Sachin Dahiya

LSU Master's Theses

Hypothermia is accepted as a method to preserve cells and tissue. Clinical evidence shows that administration of hypothermia could lead to neuroprotection after cardiac arrest. Non-invasive methods such as surface cooling devices, drugs and cold liquid ventilation are available to induce hypothermia. These approaches for achieving hypothermia have not been optimized yet. The surface cooling methods are generally slow and may lead to additional thermal shock to the body. Here, we propose a rapid, selective cooling method for the brain using a micro heat exchanger to cool the cerebrospinal fluids (CSF). We designed and 3D printed a U-type heat exchanger …

The Importance Of Co2 Recapture In The Co2 Concentrating Mechanism Of Chlamydomonas Reinhardtii, Ashwani Rai

LSU Doctoral Dissertations

The aim of this thesis is to investigate the CO₂ concentrating mechanism (CCM) of Chlamydomonas reinhardtii and to develop a quick method for estimating the activity of carbonic anhydrases (CAs). The first project demonstrates that there are two almost identical mitochondrial CAs in C. reinhardtii, CAH4 and CAH5, that help to maintain photosynthesis and minimize the leak of CO₂ generated by respiration and photorespiration. We used an RNAi approach to reduce the expression of CAH4 and CAH5 so that their physiological functions could be studied. RNAi mutants with low expression of CAH4 and CAH5 have impaired rates …

Breeding Ecology Of Mottled Ducks In Southwestern Louisiana, Elizabeth Sophia Bonczek

LSU Doctoral Dissertations

Mottled ducks are a resident species found in the southern United States that rely on coastal marsh and associated habitat to fulfill the needs of the entirety of their annual cycle. Population monitoring has revealed declines in western Gulf Coast (WGC) mottled ducks since 2008. Mottled duck populations are influenced by survival and recruitment, and changes in these factors may contribute to population declines. The overarching goal of this project was to identify the mechanisms potentially limiting WGC mottled ducks.

I captured adult female mottled ducks during molt on Rockefeller Wildlife Refuge and adjacent lands in southwestern Louisiana from 2017–2019. …

Plastic And Evolved Responses In The Eastern Oyster, Crassostrea Virginica, To Environmental Variation In The Northern Gulf Of Mexico, Kyle Sirovy

LSU Doctoral Dissertations

Climate change and other anthropogenic impacts are causing rapid alterations to many of the world’s most productive coastal ecosystems and there is an urgent need to understand how species will respond to these environmental changes. Organisms may respond through plasticity, evolution, or the evolution of plasticity. In this dissertation, I evaluate the role of plastic and evolved responses in the eastern oyster, Crassostrea virginica, to environmental variation in the northern Gulf of Mexico. I use comparative transcriptomics, physiology, and morphology to examine the relative contribution of plastic and evolved responses for oysters exposed to low salinity and outplant sites …

A Wet/Dry Point Treatment Method Of Fvcom, Part Ii: Application To The Okatee/Colleton River In South Carolina, Changsheng Chen, Haosheng Huang, Huichan Lin, Jack Blanton, Chunyan Li, Francisco Andrade

Faculty Publications

The wet/dry point treatment method of FVCOM was applied to simulate the tide-induced flooding/drying process in the estuarine–tidal-creek–saltmarsh complex of the Okatee/Colleton River Estuary, South Carolina. The simulation results were compared with observed currents at three mooring sites and flooded areas observed from remote-sensing hypsometric measurements, demonstrating that FVCOM can robustly reproduce tidal and residual currents in the river and the flooding process onto the intertidal saltmarsh. The simulated flow field reveals that the Okatee/Colleton River Estuary is characterized by multiple residual eddies. Driven by the periodic tidal forcing, this estuarine system features a chaotic water transport process. Numerous residual …

The Alpha-7 Nicotinic Acetylcholine Receptor Agonist Gts-21 Engages The Glucagon-Like Peptide-1 Incretin Hormone Axis To Lower Levels Of Blood Glucose In Db/Db Mice, Qinghe Meng, Oleg G. Chepurny, Colin A. Leech, Napat Pruekprasert, Megan E. Molnar, James Jason Collier, Robert N. Cooney, George G. Holz

Division of Basic Science Faculty Publications

Aim: To establish if alpha-7 nicotinic acetylcholine receptor (α7nAChR) agonist GTS-21 exerts a blood glucose-lowering action in db/db mice, and to test if this action requires coordinate α7nAChR and GLP-1 receptor (GLP-1R) stimulation by GTS-21 and endogenous GLP-1, respectively. Materials and Methods: Blood glucose levels were measured during an oral glucose tolerance test (OGTT) using db/db mice administered intraperitoneal GTS-21. Plasma GLP-1, peptide tyrosine tyrosine 1-36 (PYY1-36), glucose-dependent insulinotropic peptide (GIP), glucagon, and insulin levels were measured by ELISA. A GLP-1R–mediated action of GTS-21 that is secondary to α7nAChR stimulation was evaluated using α7nAChR and GLP-1R knockout (KO) mice, or …

Was The Decline Of Saltmarsh Tabanid Populations After The 2010 Oil Spill Associated With Change In The Larval Food Web?, Claudia Husseneder, Devika R. Bhalerao, Lane D. Foil

Faculty Publications

Horse flies of the species Tabanus nigrovittatus and Tabanus acutus are native to coastal marshlands. Their larvae are apex invertebrate predators, and their development is dependent on the food web in the marsh sediment. Surveillance of T. nigrovittatus after the 2010 Deepwater Horizon Oil Spill in the Gulf of Mexico showed population crashes of adult flies in southeast Louisiana marshes near oil landfall, but not in southwest Louisiana where oil did not reach. Sediment collection in 2011 from Louisiana marshes showed a near-complete absence of larvae in the southeast yet high numbers in the southwest. We hypothesized that oil contamination …

Louisiana Agriculture Summer, 2022

Louisiana Agriculture

LSU AgCenter researchers constantly search for ways to improve Louisiana agriculture by increasing yields and profitability. They also seek to understand new and less popular crops that could thrive in our region. Professor Yan Chen is helping develop the tea industry along the Gulf Coast, working closely with producers to understand how to grow tea (Camellia sinensis) in the region, and her work is featured in the latest issue of Louisiana Agriculture magazine. The magazine also includes a look into Grow Louisiana and Growing Farmers, two programs designed to help beginning farmers learn the business. Researchers from the …

Central - Summer 2022, Lsu Agcenter

Horticulture Hints

No abstract provided.

Polyunsaturated Fatty Acid Intake And Brain Health: Balance Is The Key, Candida J. Rebello

Clinical Research Faculty Publications

No abstract provided.

Edwardsiella Ictaluri T3ss Effector Esen Modulates Expression Of Host Genes Involved In The Immune Response, Lidiya P. Dubytska, Ranjan Koirala, Azhia Sanchez, Ronald Thune

Faculty Publications

The type III secretion system (T3SS) effector EseN is encoded on the Edwardsiella ictaluri chromosome and is homologous to a family of T3SS effector proteins with phosphothreonine lyase activity. Previously we demonstrated that E. ictaluri invasion activates extracellular signal-regulated kinases 1 and 2 (ERK1/2) early in the infection, which are subsequently inactivated by EseN. Com-parative transcriptomic analysis showed a total of 753 significant differentially expressed genes in head-kidney-derived macrophages (HKDM) infected with an EseN mutant (∆EseN) compared to HKDM infected with wild-type (WT) strains. This data strongly indicates classical activation of macrophages (the M1 phenotype) in response to E. ictaluri …

The Dual Nature Of The Nucleolus, Alan Tartakoff, Patrick Dimario, Eduard Hurt, Brian Mcstay, Vikram Govind Panse, David Tollervey

Faculty Publications

The nucleolus is best known for housing the highly ordered assembly line that produces ribosomal subunits. The >100 ribosome assembly factors in the nucleolus are thought to cycle between two states: an operative state (when integrated into subunit assembly intermediates) and a latent state (upon release from intermediates). Although it has become commonplace to refer to the nucleolus as “being a multilayered condensate,” and this may be accurate for latent factors, there is little reason to think that such assertions pertain to the operative state of assembly factors.

Mitochondrial Dna And Other Lines Of Evidence Clarify Species Diversity In The Peromyscus Truei Species Group (Cricetidae: Neotominae), Giovani Hernández-Canchola, Livia León-Paniagua, Jacob A. Esselstyn

Faculty Publications

Deer mice (genus Peromyscus) are among the commonest small mammals in the Nearctic zoogeographic region. Nevertheless, systematic relationships are only partially settled and numerous taxonomic questions await resolution. For instance, researchers have found that some members of the Peromyscus truei species group contain high levels of genetic divergence that could indicate the presence of cryptic species. We analyzed the systematics and phylogenetic relationships of the P. truei group using new and previously published mitochondrial cytochrome b sequences. Our analyses verify several earlier conclusions, but we also detected new clades that deserve recognition. Considering their mitochondrial distinctiveness, allopatric ranges, and previously …

Branched-Chain Amino Acids And Their Interactions With Lipid Metabolites For Increased Risk Of Gestational Diabetes, Ninghua Li, Jing Li, Hui Wang, Jinnan Liu, Weiqin Li, Kai Yang, Xiaoxu Huo, Junhong Leng, Zhijie Yu, Gang Hu, Zhongze Fang, Xilin Yang

Population and Public Health Science Faculty Publications

Objective: We aimed to explore associations of branched-chain amino acids (BCAA) in early pregnancy with gestational diabetes mellitus (GDM), and whether high BCAAs and lipidomics markers had interactive effects on the risk of GDM. Methods: We conducted a 1:1 case-control study (n=486) nested in a prospective cohort of pregnant women in Tianjin, China. Blood samples were collected at their first antenatal care visit (median 10 gestational weeks). Serum BCAAs, saturated fatty acids (SFA) and lysophosphatidylcholines (LPC) were measured by liquid chromatography-tandem mass spectrometry analysis. Conditional logistic regression was performed to examine associations of BCAAs with the risk of GDM. Interactions …

Planetary-Scale Change To The Biosphere Signalled By Global Species Translocations Can Be Used To Identify The Anthropocene, Mark Williams, Reinhold Leinfelder, Anthony D. Barnosky, Martin J. Head, Francine M.G. Mccarthy, Alejandro Cearreta, Stephen Himson, Rachael Holmes, Colin N. Waters, Jan Zalasiewicz, Simon Turner, Mary Mcgann, Elizabeth A. Hadly, M. Allison Stegner, Paul Michael Pilkington, Jérôme Kaiser, Juan Carlos Berrio, Ian P. Wilkinson, Jens Zinke, Kristine L. Delong

Faculty Publications

We examine three distinctive biostratigraphic signatures of humans associated with hunting and gathering, landscape domestication and globalization. All three signatures have significant fossil records of regional importance that can be correlated inter-regionally and help describe the developing pattern of human expansion and appropriation of resources. While none have individual first or last appearances that provide a globally isochronous marker, all three signatures overlap stratigraphically, in that they are part of a continuum of change, with complex regional patterns. Here we show that during the later stages of globalization, late nineteenth to twentieth century records of species translocations can be used …