Life Sciences Commons^™

Geometric Visual Illusion Effects On Visual Perception And Visuomotor Control: Emphasis On The Vertical-Horizontal Illusion, Shijun Yan

LSU Doctoral Dissertations

The focus of this dissertation was to explore the effects of potential vertical-horizontal (V-H) illusory influences on perceptuomotor control. As part of this focus, we examined the potential use of separate cortical visual streams: the ventral visual stream for perception and the dorsal visual stream for action. Three studies were conducted to determine the effects of the V-H illusion influences on length estimations using upper limb point-to-point movements and lower limb stepping movements, involving various illusory configurations, movement directions, gaze directions. After a short introduction (Chapter 1) and a more detailed review of existing literature (Chapter 2), we present manuscripts …

Characterization Of Drosophila Boundary Element Associated Factor Beaf-32b Interactions With Transcription Factors And Chromatin Remodeling Complexes., Yuankai Dong

LSU Doctoral Dissertations

BEAF (Boundary Element-Associated Factor) was originally identified as a chromatin domain insulator binding protein, suggesting that it might play a role in linking gene regulation to chromatin organization and dynamics. Genome-wide mapping found that BEAF is usually found near transcription start sites, often of housekeeping genes, suggesting that it might play a role in promoter function. This would be a nontraditional role for an insulator binding protein. To gain insight into molecular mechanisms of BEAF function, we identified proteins that interact with BEAF using yeast 2-hybrid assays. Here we focus on three identified transcription factors: Bcd, Scr and Sry-δ. Interactions …

Genomics And Population History Of Black-Headed Bulbul (Brachypodius Atriceps) Color Morphs, Subir B. Shakya

LSU Doctoral Dissertations

Intraspecific polymorphism in birds, especially color polymorphism, is an area of active research in evolutionary biology. In this dissertation, I applied WGS to uncover the potential genetic underpinnings of color polymorphism in the Black-headed Bulbul (Brachypodius atriceps) of Southeast Asia. This species was selected because of the heterogeneous dispersion of two morphs across its range: a yellow form predominating on mainland Asia and the Greater Sunda Islands and a gray morph on two islands—Bawean and Maratua.

I approached this project from three angles. First, I reconstructed the phylogeny of the bulbul family, Pycnonotidae, to examine patterns of coloration …

Taxonomy And Systematics Of The New Zealand Pselaphini (Coleoptera: Staphylinidae: Pselaphinae), Brittany Elin Owens

LSU Doctoral Dissertations

The New Zealand (NZ) Pselaphini was revised at the species level, a phylogenetic analysis was performed using morphological data, and first steps were taken towards the construction of a molecular analysis of the tribe. Eight new genera and 33 new species were discovered from specimens collected from the NZ mainland, offshore islands, Chatham Islands and the Subantarctic Islands. Of the 13 species originally described in the genus Pselaphus by Thomas Broun during the late 19^th and early 20^th centuries, all were either reassigned to the genera Pselaphaulax and Pselaphogenius, or were placed into new genera. Three names …

Functions Of Cdk/Cyclin Complexes In Endoreplication Regulation By The Cdk Inhibitor Siamese, Kai Wang

LSU Doctoral Dissertations

Arabidopsis trichome (leaf hair) is a specialized single cell extended from epidermal cell on the leaves, which is a typical endoreplication and is also known as endoreduplication. Several D-type cyclins were tested to check the cell division in trichome, and the trichome expressing either CYCB1;2 or CDKB2;2 cannot trigger cell division, even if simultaneous expression of CYCB1;2 and CDKB2;2 failed to produce mitosis in trichome. Only CYCD3;1 specifically promotes multicellular trichome. cdkb1;1cdbk1;2 double mutants and sim cdkb1;1cdkb1;2 triple mutants exhibit the phenotype similar to the wild type and very limited cell division respectively. Overexpression of a CDKB1;1 dominant-negative construct that …

Natural Variation And Evolutionary Responses To Climate Change Stressors In Marine Invertebrates, Joanna Sarah Griffiths

LSU Doctoral Dissertations

Our rapidly changing climate is putting many species at risk of extinction and there is an urgent need to understand how species will respond to these changes. In this dissertation, I evaluate how three species of marine invertebrates (corals, oysters, and copepods) respond to stressful conditions in their current environments and how plasticity and evolutionary adaptation could alter their response to future climate change stressors. I first employed a space for time study to elucidate population differences in the response of cold-water corals, Balanophyllia elegans, to future ocean acidification. I found evidence that upwelling history (natural low pH exposure) influences …

Phenotypic And Genotypic Characterization Of Aroma And Cercospora Janseana Resistance In U.S. Rice, Christopher Keith Addison

LSU Doctoral Dissertations

Rice is a staple food for over one-third of the world’s population. With the increasing population, plant breeders must continue to breed for improved varieties. The utilization of markers to applied breeding program can increase the efficiency of selection for key traits. The targeted traits for this research include grain aroma and resistance to the fungal disease narrow brown leaf spot (Cercospora janseana). Our objective was to characterize SNP diversity across the BADH2 gene in publicly available sequence data of a collection of 2,932 rice varieties was characterized to determine the number of gene haplotypes in O. sativa. …

Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan

LSU Doctoral Dissertations

The impacts of sea-level rise and hydrologic manipulation are threatening the stability of coastal marshes throughout the world, thereby increasing the potential for re-mineralization of soil organic matter (SOM) in these systems. Such threats have prompted marsh restoration efforts, particularly in coastal Louisiana, yet it is unclear how the slowly decomposing (refractory) and quickly decomposing (labile) fractions of SOM may be differentially affected by different approaches to marsh restoration. Additionally, otherwise labile compounds may accumulate in the soil via a range of protective mechanisms, including rapid burial and association with organic compounds that are thought to enhance soil aggregation, such …

Synthesis And Preliminary Ex Vivo Testing Of Sirna Targeting Tcrb: A Proposed Therapy For The Treatment Of Autoimmunity, Nicholas J. Magazine

LSU Doctoral Dissertations

Abstract

Background:

As of 2018, the United States National Institutes of Health estimate that over half a billion people worldwide are affected by autoimmune disorders. Though these conditions are prevalent, treatment options remain relatively poor, relying primarily on various forms of immunosuppression which carry potentially severe side effects and often lose effectiveness overtime. Given this, new forms of therapy are needed. We propose small-interfering RNA (siRNA) for hypervariable regions of the T-cell receptor β-chain gene (TCRb) as a highly targeted, novel means of therapy for the treatment of autoimmune disorders.

Objectives:

To develop methods to produce siRNA targeting …

Impacts Of The Deepwater Horizon Oil Spill On Reproduction And Ontogeny Of Gulf Killifish (Fundulus Grandis), Charles Alexander Brown

LSU Doctoral Dissertations

On April 20, 2010, the Deepwater Horizon oil spill released an estimated 779 million liters of Macondo-252 crude oil into the Gulf of Mexico, making it the largest marine oil spill in history. Over a thousand kilometers of marshland that many species of fish use as a spawning grounds and nurseries was oiled, exposing breeding adult fish and their offspring to oil. My dissertation investigates the impacts of the Deepwater Horizon oil spill and associated remediation efforts on the reproduction and ontogeny of a sentinel ecotoxicological species, the Gulf killifish (Fundulus grandis). Concerns were raised regarding use of …

Sodium Propionate And Sodium Butyrate Promote Fatty Acid Oxidation In Hepg2 Cells Under Oxidative Stress, Kristina Jazmin Cook

LSU Doctoral Dissertations

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disturbances that includes simple steatosis, non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and liver cancer. NAFLD affects individuals that consume the typical Western diet consisting of high levels of fats and carbohydrates. The increase in circulating free fatty acids, palmitate and oleate, or lipopolysaccharides (LPS), induce oxidative stress and pro-inflammatory cytokine production in the liver, which all contribute to NAFLD progression. In this study, we are evaluating the mRNA expression of genes associated with fatty acid oxidation (FAO) and the protein expression of pro-inflammatory cytokines related to NAFLD using the HepG2 human liver …