Search Results

Acute and Sublethal Impacts of Crude Oil Photo-Induced Toxicity in an Early Life Stage Marine Fish (Sciaenops ocellatus) and Invertebrate (Americamysis bahia)

Description: We investigated the modifying effects of ultraviolet (UV) light and chemical dispersant (Corexit 9500A) on crude oil toxicity in juvenile mysids (≤ 24 h) (Americamysis bahia) and larval red drum (24-72 hpf) (Sciaenops ocellatus). These results demonstrate that crude oil toxicity significantly increases with co-exposure to environmentally relevant UV levels in both species, indicating photo-induced toxicity. This toxicity was further exacerbated by the application of chemical dispersants which i… more
This item is restricted from view until January 1, 2025.
Date: December 2023
Creator: Leads, Rachel Renee
Partner: UNT Libraries
open access

The Acute Toxic Effects of the Synthetic Cannabinoid, JWH-018 on the Cardiovascular and Neuroendocrine Systems in Ictalurus punctatus (Channel Catfish)

Description: Cannabinoid (CB) receptors have been found in most vertebrates that have been studied. The location of various CB receptors in the body and brain are known, but their physiological functions are not fully understood. The effects CBs have on the cardiovascular system have been of growing interest in recent years. Increasing reports from emergency departments and law enforcement agencies detail acute cardiovascular and psychological effects from synthetic CB intoxication, such as JWH-018. This ma… more
Date: August 2017
Creator: Taylor, Dedric Esmond
Partner: UNT Libraries
open access

The Adolescent Stress Response to a Naturalistic Driving Stressor

Description: The proposed study examined the role of anxiety and risk-taking in driving performance in adolescents. In addition to examining the sample as a whole, gender differences were assessed given earlier reports from our laboratory and others indicating that males and females differ with respect to risky behaviors to driving performance and anxiety. Adolescents' subjective and physiological responses to a driving simulator task were assessed. Anxiety was measured via self report and salivary cortisol… more
Date: August 2000
Creator: Wingo, Mary
Partner: UNT Libraries
open access

Age-Dependent Effects Of Chronic GABAA Receptor Blockade In Barrel Cortex

Description: GABAA receptor binding is transiently increased in rat whisker barrels during the second postnatal week, at a time when neurons in the developing rat cortex are vulnerable to excitotoxic effects. To test whether these GABAA receptors might serve to protect neurons from excessive excitatory input, polymer implants containing the GABAA receptor antagonist bicuculline were placed over barrel cortex for a 4-day period in young (postnatal days 8 - 12) and adult rats. In the cortex of young, but no… more
Date: May 2001
Creator: Gargan, Lynn
Partner: UNT Libraries
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.
Partner: UNT Libraries
open access

Alterations in Human Baroreceptor Reflex Regulation of Blood Pressure Following 15 Days of Simulated Microgravity Exposure

Description: Prolonged exposure to microgravity is known to invoke physiological changes which predispose individuals to orthostatic intolerance upon readaptation to the earth's gravitational field. Attenuated baroreflex responsiveness has been implicated in contributing to this inability to withstand orthostatic stress. To test this hypothesis, eight individuals were exposed to 15 days of simulated microgravity exposure using the 6° head-down bed rest model. Prior to, and after the simulated microgravity e… more
Date: August 1993
Creator: Crandall, Craig G. (Craig Gerald)
Partner: UNT Libraries

Alterations in the Expression of Proteins Associated with Non-Alcoholic Fatty Liver Disease Observed in the Liver of the C57Bl/6 Wild-Type Male Mouse in Response to Exposure of Mixed Vehicle Emissions and/or High Fat Diet Consumption

Description: Recent epidemiological studies have demonstrated a correlation between the manifestation of non-alcoholic fatty liver disease (NAFLD) and ambient air pollution levels, which is exacerbated by the presence of other risk factors, such as diabetes, dyslipidemia, obesity, and hypertension. We investigated the hypothesis that exposure to a mixture of gasoline and diesel engine emissions (MVE) coupled with the concurrent consumption of a high-fat (HF) diet promotes the development of a NAFLD phenotyp… more
This item is restricted from view until January 1, 2025.
Date: December 2022
Creator: Schneider, Leah Jayne
Partner: UNT Libraries

Analysis of Multipartite Bacterial Genomes Using Alignment-Free and Alignment-Based Pipelines

Description: In this work, we have performed comparative evolutionary analysis, functional genomics analysis, and machine learning analysis to identify the molecular factors that discriminate between multipartite and unipartite bacteria, with the goal to decipher taxon-specific factors and those that are prevalent across the taxa underlying the these traits. We assessed the roles of evolutionary mechanisms, namely, horizontal gene transfer and gene gain, in driving the divergence of bacteria with single and… more
Date: August 2021
Creator: Almalki, Fatemah
Partner: UNT Libraries
open access

Analysis of the Accumulation, Toxic Effects, and Risk of Persistent Organic Pollutants in Pinnipeds

Description: The present studies determine the accumulation of persistent organic pollutants (POPs) in three pinniped species, evaluate the relationship with relevant biomarkers of exposure, and calculate toxic effect thresholds. Stranded harp and hooded seals were found to be accumulating PBDEs at levels which could pose a based on threshold levels determined in this study. Northern fur seals are accumulating all three classes of POPs (PCBs, PBDEs, and OCPs) with significant relationships being seen with b… more
Date: August 2021
Creator: Soulen, Brianne K
Partner: UNT Libraries
open access

Analysis of the Trypanosoma brucei Genome and Identification and Characterization of a Gene Family Encoding Putative EF-Hand Calcium-Binding Proteins

Description: The flagellum of Trypanosoma brucei contains a family of antigenically related EF-hand calcium-binding proteins which are called the calflagins. Genomic Southern blots indicated that multiple copies of calflagin genes occur in T brucei. All of the copies were contained in a single 23 kb Xhol-Xhol fragment. Genomic fragments of 2.5 and 1.7 kb were cloned that encoded calflagin sequences. Two new members of the calflagin family were found from genomic clone sequences. The deduced amino acid seque… more
Date: May 1998
Creator: DeFord, James H. (James Henry), 1956-
Partner: UNT Libraries
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
Partner: UNT Libraries

Application of Cultured Neuronal Networks for Use as Biological Sensors in Water Toxicology and Lipid Signaling.

Description: This dissertation research explored the capabilities of neuronal networks grown on substrate integrated microelectrode arrays in vitro to be applied to toxicological research and lipid signaling. Chapter 1 details the effects of chlorine on neuronal network spontaneous electrical activity and pharmacological sensitivity. This study demonstrates that neuronal networks can maintain baseline spontaneous activity, and respond normally to pharmacological manipulations in the present of three times… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: August 2004
Creator: Dian, Emese Emöke
Partner: UNT Libraries
open access

Applications of GIS and Remote Sensing for the Characterization of Habitat for Threatened and Endangered Species

Description: Geographic Information Systems (GIS) and remote sensing technologies were used to identify and describe potential habitat for three species endemic to the Southwestern United States; the Golden-cheeked Warbler (Dendroica chrysoparia), the Black-capped Vireo (Vireo atricapillus), and the Texas kangaroo rat (Dipodomys elator). For each species, the computerized classification of digital satellite imagery was integrated with ancillary spatial information (e.g. soils, geology, and land use) to con… more
Date: December 1989
Creator: Shaw, Denice Marie, 1958-
Partner: UNT Libraries
open access

Assembly of Pseudomonas putida Aspartate Transcarbamoylase and Possible Roles of the PyrC' Polypeptide in the Folding of the Dodecameric Enzyme

Description: Aspartate transcarbamoylase (ATCase) of Pseudomonas putida consists of two different polypeptides, PyrB and PyrC' (Schurr et al, 1995). The role of the PyrC' and the assembly of PyrB and PyrC' have been studied. The ATCase made in vitro of P.putida PyrB with P.putida PyrC', and of E.coli PyrB with P.putida PyrC ' were generated under two different conditions, denaturation and renaturation, and untreated. It was found that PyrC' plays a role in the enzymatic regulation by ATP, CTP and UTP. In … more
Date: May 1999
Creator: Hongsthong, Apiradee, 1970-
Partner: UNT Libraries

Automated Low-cost Instrument for Measuring Total Column Ozone

Description: Networks of ground-based and satellite borne instruments to measure ultraviolet (UV) sunlight and total column ozone have greatly contributed to an understanding of increased amounts of UV reaching the surface of the Earth caused by stratospheric ozone depletion. Increased UV radiation has important potential effects on human health, and agricultural and ecological systems. Observations from these networks make it possible to monitor total ozone decreases and to predict ozone recovery trends … more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: May 2006
Creator: Nebgen, Gilbert Bernard
Partner: UNT Libraries
open access

Autoradiographic Localization of Carbachol-Induced Second Messenger Response in the Rat Spinal Cord Following Inflammation.

Description: This study examined central mechanisms of persistent pain using an autoradiographic technique to localize phosphoinositide hydrolysis (PI) in the rat spinal cord dorsal horn. The lateral half of laminae I-II showed the highest levels of baseline PI turnover and carbachol-stimulated PI turnover in normal animals as well as after inflammation. Inflammation resulted in increased baseline PI turnover in this region of the ipsilateral (76%) and contralateral (65%) dorsal horns. Carbachol increased P… more
Date: May 2002
Creator: Moore, Jack
Partner: UNT Libraries

Benefits of Probiotics on Mortality, Growth Performance, Physiological Condition and Gut Histomophology of Juvenile Red Drum (Sciaenops ocellatus)

Description: Results from the present study found for the first time that the use of bacterial strains of Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium thermophilum, and Enterococcus faecium from the commercial product PrimaLac® had the potential to act as a possible probiotic for juvenile red drum. The addition of PrimaLac® probiotics [whether as a water-soluble probiotic (WSP) or in a probiotic enhanced starter feed (PESF)] reduced mortality (%M), enhanced growth rates (MW, LT, SGR, and … more
Date: May 2021
Creator: Busby, Wren Adell
Partner: UNT Libraries
open access

Benthic Macroinvertebrates of Temperate, Sub-Antarctic Streams: The Effects of Altitudinal Zoning and Temperature on the Phenology of Aquatic Insects Associated to the Robalo River, Navarino Island (55°S), Chile

Description: The Cape Horn Biosphere Reserve, within the remote Sub-Antarctic ecoregion is a reservoir of expressions of biological and cultural diversity. Although it is considered one of 24 wilderness areas remaining in the world, it is not free from local and global threats, such as invasive species, and climate change. Field biologists and philosophers associated to the Sub-Antarctic Biocultural Conservation Program and the Omora Ethnobotanical Park, have worked to describe the region’s biocultural dive… more
Date: December 2011
Creator: Contador Mejías, Tamara Andrea
Partner: UNT Libraries
open access

Biochemical Genetics of the Pocket Gopher Genus Geomys, and its Phylogenetic Implications

Description: Electrophoretic techniques were utilized for the demonstration of variation in 22 proteins from 24 natural populations of four species ( G. bursarius, G. pinetis, G. arenarius and G. personatus ) of the Geomys complex of pocket gophers. Of the 24 structural loci , 19 were considered to be polymorphic. Five of the six esterases contributed greatested to the polymorphism while non-esterase proteins generally showed low values. In the GeoMys complex of pocket gophers in this study,selection appear… more
Date: December 1974
Creator: Penney, Dan F.
Partner: UNT Libraries
open access

Biochemical Identification of Molecular Components Required for Cyanide Assimilation in Pseudomonas fluorescens NCIMB 11764

Description: Utilization of cyanide as a nutritional nitrogen source in P. fluorescens NCIMB 11764 was shown to involve a novel metabolic mechanism involving nonenzymatic neutralization outside of cells prior to further enzymatic oxidation within. Several cyanide degrading enzymes were produced by NCIMB 11764 in response to growth or exposure to cyanide, but only one of these cyanide, oxygenase (CNO), was shown to be physiologically required for assimilation of cyanide as a growth substrate.
Date: May 1998
Creator: Chen, Jui-Lin
Partner: UNT Libraries
open access

Biodiversity of Caddisflies (Trichoptera) of the Interior Highlands of North America

Description: Caddisflies (Trichoptera) were collected from over 500 different locations throughout the Interior Highlands (Ozark, Ouachita, Arbuckle, and Wichita Mountains) between March 1990 and March 1994. I systematically sampled representative lotic and lentic habitats in 131 natural watersheds that comprise the 17 different physiographic subregions of this area. From my examination of approximately 60,000 specimens, surveys of regional museum collections, and review of literature records, I document 22… more
Date: August 1994
Creator: Moulton, Stephen R. (Stephen Richard)
Partner: UNT Libraries
open access

Biodiversity of Dragonflies and Damselflies (Odonata) of the South-Central Nearctic and Adjacent Neotropical Biotic Provinces

Description: The south-central United States serves as an important biogeographical link and dispersal corridor between Nearctic and Neotropical elements of western hemisphere odonate faunas. Its species are reasonably well known because of substantial collections, but there has been no concerted effort to document the extent of biodiversity and possible geographic affinities of dragonflies and damselflies of this region. The recent discoveries of Argia leonorae Garrison, Gomphus gonzalezi Dunkle and Erpeto… more
Date: May 1999
Creator: Abbott, John C.
Partner: UNT Libraries
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