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open access

Adaptive Advantages of Carotenoid Pigments in Alpine and Subalpine Copepod Responses to Polycyclic Aromatic Hydrocarbon Induced Phototoxicity

Description: Alpine zooplankton are exposed to a variety of stressors in their natural environment including ultraviolet radiation. Physiological coping mechanisms such as the accumulation of photoprotective compounds provide these zooplankton protection from many of these stressors. Elevated levels of carotenoid compounds such as astaxanthin have been shown to help zooplankton survive longer when exposed to ultraviolet radiation presumably due to the strong antioxidant properties of carotenoid compounds. T… more
Date: May 2010
Creator: Kovach, Matthew James
Item Type: Refine your search to only Thesis or Dissertation
open access

Adrenergic and Cholinergic Regulation of Cardiovascular Function in Embryonic Neotropic Cormorants (Phalacrocorax basilianus)

Description: Investigations of cholinergic and adrenergic tone on heart rate (fH) and mean arterial pressure (Pm) during embryonic development have been conducted on numerous avian species. While these investigations have documented that adrenergic tone, a continuous stimulation, on fH and Pm is vital to embryonic development in the birds studied to date, development of cholinergic tone on fH has been shown to vary even within species. Further, past studies have been bias to focus primarily on precocial spe… more
Date: May 2017
Creator: Cummins, James B.
Item Type: Refine your search to only Thesis or Dissertation
open access

Aging Is a Determinant in Anoxia Stress Tolerance in Caenorhabditis Elegans

Description: Oxygen availability is critical for survival for most organisms. The nematode, C. elegans, has been useful for studying genetic regulation of anoxia tolerance due to the oxygen deprivation response mechanisms shared with other metazoans. Studies examining long-term anoxia (72h, LTA) tolerance have only been conducted at adult day 1. To investigate the effect of aging on anoxia tolerance wild-type and mutant strains were exposed to LTA between adult day 1 and day 9. Wild-type isolates and daf-16… more
Date: May 2013
Creator: Goy, Jo M.
Item Type: Refine your search to only Thesis or Dissertation
open access

Alterations in Fatty Acid Amide Hydrolase (Faah) Transcript Levels and Activity Lead to Changes in the Abiotic Stress Susceptibility of Arabidopsis Thaliana

Description: N-Acylethanolamines (NAEs) are a class of bioactive lipids, and FAAH is one of the enzymes responsible for degrading NAEs in both plants and animals. in plants, FAAH appears to be closely associated with ABA, a phytohormone which has long been associated with plant stress responses, since the overexpression of FAAH in Arabidopsis results in ABA hypersensitivity. Therefore, it is reasonable to speculate that alterations in FAAH transcript levels will result in altered stress responses in plant… more
Date: May 2012
Creator: Gonzalez, Gabriel
Item Type: Refine your search to only Thesis or Dissertation
open access

American Lawn Addictions: Effects of Environmental Education on Student Preferences for Xeriscaping as an Alternative in North Central Texas, USA

Description: Urban land use and land cover has changed in the USA, giving rise to the American lawn – manicured, resource-intensive, and non-native. Green infrastructure design has been suggested in the literature as a potential alternative to the American lawn when managed as native xeriscapes, which require little to no irrigation after establishment. Given the influence of public preference on landscaping decisions, what is the relationship between the perceived value and ecological benefits of the Ameri… more
Date: May 2019
Creator: Williams, Jared L.
Item Type: Refine your search to only Thesis or Dissertation
open access

Anatomical and Morphological Responses of Cardiospermum Halicacabum L. (Balloon Vine), to Four Levels of Water Availability

Description: C. halicacabum (Sapindaceae) is an invasive plant that is considered a nuisance species in Texas riparian environments. Little is known of the tolerance of C. halicacabum to flooding and drought; however, this information may provide insight into the characteristics that contribute to C. halicacabum purported invasiveness. C. halicacabum seedlings (n = 92) were exposed to one of four levels of water availability (flooded, saturated, intermediate and dry) over six weeks under greenhouse conditio… more
Date: May 2011
Creator: Dempsey, Matthew Anthony
Item Type: Refine your search to only Thesis or Dissertation
open access

Antimicrobial and Anti-Platelet Activity in Botanical Extracts of Plants Collected in Northern Thailand

Description: The purpose of my research work was to assess a variety of Northern Thailand plants tissue extracts for antibacterial and anti-platelet aggregation activity. The Minimum Inhibitory Concentration assay method was used to assess antimicrobial activity of plant extracts, while the Zebrafish Platelet Aggregation Assay and the in vitro Whole Human Blood Impedance Aggregation Assay were used to study anti-platelet activity. Forty one plant extracts harvested from the tissues of 26 plants collected fr… more
Date: May 2019
Creator: Patcharapinyopong, Thanasan
Item Type: Refine your search to only Thesis or Dissertation
open access

Bioconcentration and Morphological Effects of Triclosan on Three Species of Wetland Plants

Description: Triclosan (TCS) is an antimicrobial compound found in several types of common household products. After being washed down the drain, TCS will then end up in the local watershed. Although numerous studies have been conducted to evaluate the fate and effects of TCS in aquatic environments, there have been no studies evaluating the role arbuscular mycorrhizal fungi (AM) play in a plants response to TCS exposure. Three species of wetland plants native North Texas were inoculated with AM spores and … more
Date: May 2013
Creator: Smith, Caleb M.
Item Type: Refine your search to only Thesis or Dissertation
open access

Biodiversity and Genetic Structure of Benthic Macroinvertebrates Along an Altitudinal Gradient: A Comparison of the Windhond and Róbalo River Communities on Navarino Island, Chile

Description: Altitudinal gradients in Sub-Antarctic freshwater systems present unique opportunities to study the effect of distinct environmental gradients on benthic macroinvertebrate community composition and dispersal. This study investigates patterns in biodiversity, dispersal and population genetic structure of benthic macroinvertebrate fauna across an altitudinal gradient between two watersheds on Navarino Island in southern Chile. Patterns in diversity, density, evenness and functional feeding grou… more
Date: May 2016
Creator: Pulliam, Lauren
Item Type: Refine your search to only Thesis or Dissertation
open access

The Biogeographic Distribution of Caddisflies (Insecta: Trichoptera) within the South-Central United States

Description: Through the use of natural history records, published literature, and personal sampling (2011-2016) a total of 454 caddisfly species represented by 24 families and 93 genera were documented from the south-central United States. Two Hydroptilidae species were collected during the 2011-2016 collection efforts that are new to the region: Hydroptilia scheringi and Mayatrichia tuscaloosa. Eightteen species are endemic and 30 are considered species of concern by either federal or state agencies. The … more
Date: May 2018
Creator: Perry, Heather Ann
Item Type: Refine your search to only Thesis or Dissertation
open access

The Bobwhite Population Decline: Its History, Genetic Consequences, and Studies on Techniques for Locating and Assessing Current Populations

Description: The northern bobwhite (Colinus virginianus) population decline is a severe, rangewide phenomenon beginning >150 years ago and continuing today. In this investigation, I: 1. document the timeline of bobwhite population decline and unintended genetic consequences of attempted remedies, 2) develop a model useful for predicting possible locations of potentially sustainable bobwhite populations in semiarid rangeland in Texas and Oklahoma, and 3) examine the relationship between population monitoring… more
Date: May 2019
Creator: Whitt, Jeffrey Glen
Item Type: Refine your search to only Thesis or Dissertation
open access

Characteristics of Primary Cilia and Centrosomes in Neuronal and Glial Lineages of the Adult Brain

Description: Primary cilia are sensory organelles that are important for initiating cell division in the brain, especially through sonic hedgehog (Shh) signaling. Several lines of evidence suggest that the mitogenic effect of Shh requires primary cilia. Proliferation initiated by Shh signaling plays key roles in brain development, in neurogenesis in the adult hippocampus, and in the generation of glial cells in response to cortical injury. In spite of the likely involvement of cilia in these events, little … more
Date: May 2015
Creator: Bhattarai, Samip Ram
Item Type: Refine your search to only Thesis or Dissertation
open access

Characterization of Triclocarban, Methyl- Triclosan, and Triclosan in Water, Sediment, and Corbicula Fluminea (Müller, 1774) Using Laboratory, in Situ, and Field Assessments

Description: In the last decade emerging contaminants research has intensified in a bid to answer questions about fate, transport, and effects as these chemicals as they get released into the environment. The chemicals of interest were the antimicrobials; triclocarban (TCC) and triclosan (TCS), and a metabolite of triclosan, methyl triclosan (MTCS). This research was designed to answer the question: what is the fate of these chemicals once they are released from the waste water treatment plant into receivin… more
Date: May 2011
Creator: Edziyie, Regina E.
Item Type: Refine your search to only Thesis or Dissertation
open access

Comparison and Genetic Analysis of Host Specificity in Cluster BD1 Bacteriophages infecting Streptomyces

Description: Bacteriophages are viruses that specifically infect bacteria. When a phage infects a bacterium, it attaches itself to the surface of the bacteria and injects its DNA into the intracellular space. The phage DNA hijacks the cellular machinery of the bacteria and forces it to produce phage proteins. Eventually, the bacteria cell bursts or lyses, releasing new phage. The bacteria act as a host for phage reproduction. The ability for a phage to infect multiple bacterial species is known as host rang… more
Date: May 2019
Creator: Klug, Hannah
Item Type: Refine your search to only Thesis or Dissertation
open access

Comparison of Heteranthera Dubia (Jacq.) MacM.-associated Macroinvertebrates Between Georgraphical Regions in the United States

Description: Macroinvertebrates associated with the aquatic plant, water stargrass (Heteranthera dubia), were sampled from 12 waterbodies in four regions of the United States from June to August 2005. Taxa richness, evenness, and diversity were lowest in the Lower Midwest (LMW) region, and higher in Northern sites, especially the Upper Midwest (UMW), and Northeast (NE). While relative abundance varied from site to site and region to region, utilization of the plant by functional groups remained fairly const… more
Date: May 2010
Creator: Harms, Nathan Earl
Item Type: Refine your search to only Thesis or Dissertation
open access

A Comparison of Mercury Localization, Speciation, and Histology in Multiple Fish Species From Caddo Lake, a Fresh Water Wetland

Description: This work explores the metabolism of mercury in liver and spleen tissue of fish from a methylmercury contaminated wetland. Wild-caught bass, catfish, bowfin and gar were collected. Macrophage centers, which are both reactive and primary germinal centers in various fish tissues, were hypothesized to be the cause of demethylation of methylmercury in fish tissue. Macrophage centers are differentially expressed in fish tissue based on phylogenetic lineage, and are found primarily in the livers of p… more
Date: May 2012
Creator: Smith, James Durward
Item Type: Refine your search to only Thesis or Dissertation
open access

Cytotoxicity and Functional Toxicity of Mefloquine and the Search for Protective Compounds

Description: Mefloquine hydrochloride is an antimalarial agent that has been used for the past 40 years. Numerous reports of neurological side effects have recently led the FDA to issue a strong warning regarding long-term neurological effects. This warning lead to the U.S. Army’s Special Forces and other components to discontinue its use in July of 2013. Despite reported adverse side effects, mefloquine remains in circulation and is recommended to travelers going to specific Asian countries. Mefloquine … more
Date: May 2015
Creator: Holmes, Katelyn
Item Type: Refine your search to only Thesis or Dissertation

Defining Components Linked to Bacterial Nutritional Utilization of Cyanide as a Sole Nitrogen Source

Description: One of the challenges in biology is placing a function on the myriad of gene sequences having become available from rapid advances in genome sequencing. One such example is a gene cluster (Nit1C) found in bacteria that is tied to the unusual ability of certain bacteria to grow when supplied cyanide as the sole nitrogen source. The term cyanotrophs has been applied to such bacteria, for which a genetic linkage between cyanotrophy and Nit1C was demonstrated for 10 separate bacteria. In additio… more
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Date: May 2019
Creator: Jones, Lauren Brittany
Item Type: Refine your search to only Thesis or Dissertation
open access

Development of von Willebrand Factor Zebrafish Mutant Using CRISPR/Cas9 Mediated Genome Editing

Description: von Willebrand factor (VWF) protein acts in the intrinsic coagulation pathway by stabilizing FVIII from proteolytic clearance and at the site of injury, by promoting the adhesion and aggregation of platelets to the exposed subendothelial wall. von Willebrand disease (VWD) results from quantitative and qualitative deficiencies in VWF protein. The variability expressivity in phenotype presentations is in partly caused by the action of modifier genes. Zebrafish has been used as hemostasis animal … more
Date: May 2017
Creator: Toffessi Tcheuyap, Vanina
Item Type: Refine your search to only Thesis or Dissertation
open access

Ecological Significance and Underlying Mechanisms of Body Size Differentiation in White-tailed Deer

Description: Body size varies according to nutritional availability, which is of ecological and evolutionary relevance. The purpose of this study is to test the hypothesis that differences in adult body size are realized by increasing juvenile growth rate for white-tailed deer (Odocoileus virginianus). Harvest records are used to construct growth rate estimates by empirical nonlinear curve fitting. Results are compared to those of previous models that include additional parameters. The rate of growth increa… more
Date: May 2012
Creator: Barr, Brannon
Item Type: Refine your search to only Thesis or Dissertation
open access

The Ecology and Paleobiogeography of Freshwater Mussels (Family: Unionidae) from Selected River Basins in Texas

Description: This dissertation has two overall objectives: first, to demonstrate the utility of paleozoological data for ongoing and future mussel-conservation efforts in Texas and second, to evaluate whether simple measures of habitat (e.g., water depth, velocity and particle size) are important for demonstrating the within-habitat spatial separation of mussels. Although these topics may seem disparate, both are important for increasing our understanding of unionid ecology and biogeography. Chapters 1 th… more
Date: May 2011
Creator: Randklev, Charles R.
Item Type: Refine your search to only Thesis or Dissertation
open access

Ecology and Recolonization of Benthic Macroinvertebrates in a Groundwater-dependent Stream in North Central Texas During a Supra-seasonal Drought

Description: Extreme climatic events such as droughts are known to eliminate aquatic biota and alter community structure and function. Perennial headwater springs provide important drought refugia to benthic macroinvertebrates and an important source of colonists via drift or aerial adults to intermittent streams post-drought. During a supra-seasonal drought in North-central Texas summer and fall 2006, benthic macroinvertebrates from persistent groundwater-dependent macrohabitats of varying hydrological con… more
Date: May 2012
Creator: Burk, Rosemary A.
Item Type: Refine your search to only Thesis or Dissertation
open access

The Effect of Curcumin Supplementation on Physical and Biological Indices of Delayed Onset Muscle Soreness and Inflammation Following Muscle Injury

Description: In this project, the effects of dietary polyphenols on exercise-induced muscle damage and vascular health are examined. Dietary polyphenols exert well-known anti-inflammatory effects; however, how these effects are realized with respect to vascular health and EIMD is relatively unknown. I begin by reviewing the available literature surrounding the impact of three dietary polyphenols (curcumin, catechins, and quercetin) on inflammation associated with EIMD. It is well established that their prim… more
Date: May 2015
Creator: Venable, Adam Steven
Item Type: Refine your search to only Thesis or Dissertation
open access

The Effect of Natural Gas Well Setback Distance on Drillable Land in the City of Denton, Texas

Description: Municipalities protect human health and environmental resources from impacts of urban natural gas drilling through setback distances; the regulation of distances between well sites and residences, freshwater wells, and other protected uses. Setback distances have increased over time, having the potential to alter the amount and geographical distribution of drillable land within a municipality, thereby having implications for future land use planning and increasing the potential for future incom… more
Date: May 2014
Creator: Daniel, Michael
Item Type: Refine your search to only Thesis or Dissertation
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