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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
Item Type: Refine your search to only Thesis or Dissertation
open access

Application of Fluorescent Antibody Methods for the Enumeration and Identification of Bacillus Cereus

Description: This particular work is proposed as a test of the expedience of using the fluorescent-antibody technique as a method for enumeration and identification of certain strains of B. cereus that have been found to be effective in preventing taste and odor in water supplies resulting from certain Actinomycete blooms.
Date: August 1969
Creator: Ferebee, Robert Newton
Item Type: Refine your search to only Thesis or Dissertation
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-
Item Type: Refine your search to only Thesis or Dissertation
open access

Applications of Remote Sensing and GIS to Modeling Fire for Vegetative Restoration in Northern Arizona

Description: An accurate fire model is a useful tool in predicting the behavior of a prescribed fire. Simulation of fire requires an extensive amount of data and can be accomplished best using GIS applications. This paper demonstrates integrative procedures of using of ArcGIS™, ERDAS Imagine™, GPS, and FARSITE© to predict prescribed fire behavior on the Kaibab-Paiute Reservation. ArcGIS was used to create a database incorporating all variables into a common spatial reference system and format for the FARSIT… more
Date: August 2003
Creator: Hardison, Tanya
Item Type: Refine your search to only Thesis or Dissertation
open access

The aquatic insect communities of Holbrook Creek and Cochetopa Creek in Colorado.

Description: The first objective for this problem in lieu of thesis project was to gather, identify to the lowest practical taxonomic level and organize all available aquatic insects collected from high altitude Colorado aquatic systems during the summers of 1994, 1996, 1998, and 2002 for the University of North Texas Environmental Science Field Course (BIOL 5650). The curated collection will be housed in the Elm Fork Natural History Museum, located at the University of North Texas. The second objective was… more
Date: December 2003
Creator: Wallace, Mark Allen
Item Type: Refine your search to only Thesis or Dissertation
open access

Aquatic Vegetation Nutrient Budgets and Sedimentation in a Southwestern Reservoir

Description: During four growing seasons, aquatic vascular plant production and distribution were studied in Pat Mayse Lake, Texas, a 2425 hectare oligo-mesotrophic reservoir. The dominant macrophyte population was Myriophyllum spicatum L. Growth rates and regrowth rates of mechanically harvested Myriophyllum beds were found to be dissimilar. Based on estimates of watermilfoil nutrient content, there were insufficient nutrients in the entire population to alter the trophic status of this reservoir should al… more
Date: May 1986
Creator: Clifford, Philip A. (Philip Alan)
Item Type: Refine your search to only Thesis or Dissertation
open access

Aryl Hydrocarbon Hydroxylase and Sixteen Alpha Hydroxylase in Cultured Human Lymphocytes

Description: Cultured human lymphocytes may be assayed for aryl hydrocarbon hydroxylase (AHH) in whole cell preparations. The optimum assay conditions are pH 8.5, and 1.5 mM Mg++. The reaction is linear with time and cell number, and is inhibited by CO. Estradiol may inhibit induction of AHH by 3-methylcholanthrene, but is a poor competitor for the enzyme. A Caucasian population was assayed for AHH activity. The distribution was lognormal; no difference was found in cultured cells from males and females or … more
Date: December 1975
Creator: Coomes, Marguerite L.
Item Type: Refine your search to only Thesis or Dissertation
open access

Aspartate Transcarbamoylase of Aeromonas Hydrophila

Description: This study focused on the enzyme, aspartate transcarbamoylase (ATCase) from A. hydrophila, a Gram-negative bacterium found in fresh water. The molecular mass of the ATCase holoenzyme from A. hydrophila is 310 kDa. The enzyme is likely composed of 6 catalytic polypeptides of 34 kDa each and 6 regulatory polypeptides of 17 kDa each. The velocity-substrate curve for A. hydrophila ATCase is sigmoidal for both aspartate and carbamoylphosphate. The Km for aspartate was the highest to date for an ente… more
Date: December 2000
Creator: Higginbotham, Leah
Item Type: Refine your search to only Thesis or Dissertation
open access

An Assay Method for Determining Extra-Cellular Lipases from Pseudomonas aeruginosa

Description: The applicability of an isotopically labelled assay system to determine the lipase production in Pseudomonas aeruginosa was evaluated. Supernatant from cultures of Pseudomonas aeruginosa grown in a medium containing olive oil was incubated with a substrate containing labelled trioleate. Fatty acids were isolated by means of a liquid-liquid partition system. Enzyme activity was determined by measuring the amounts of free fatty acid by liquid scintillation counting. Findings indicate that the iso… more
Date: May 1978
Creator: Christensen, John N.
Item Type: Refine your search to only Thesis or Dissertation
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-
Item Type: Refine your search to only Thesis or Dissertation
open access

Assessing Effects of an Environmental Education Field Science Program Fostering Responsibility at an Urban Middle School

Description: The study investigated the ability of an extracurricular program to influence environmental responsibility of sixth and seventh graders. The Children's Environmental Attitude and Knowledge Survey (CHEAKS) was evaluated for appropriateness in assessing the worth of this particular environmental education strategy emphasizing water quality fieldwork and technology. CHEAKS is designed with psychometric reliability and validity that may be used in comparing disparate programs. … more
Date: May 1999
Creator: Sills, Blake
Item Type: Refine your search to only Thesis or Dissertation
open access

Assessment of Changes in Aquatic Macrophyte Occurrence Following Introduction of Triploid Grass Carp in a North Texas Reservoir

Description: The objectives of this project were to measure changes in frequency of occurrence of submerged macrophytes over the first two growing seasons following stocking with triploid grass carp at two fish per acre and to measure differences in macrophyte biomass between areas excluded from herbivory and adjacent control sites after 16 months following establishment of exclosures. The project also seeks to measure concentrations of fluridone following the herbicide treatment, and to compare two methods… more
Date: August 1997
Creator: Bickel, Ken (Kenneth E.)
Item Type: Refine your search to only Thesis or Dissertation
open access

Assimilation of Organic Carbon by Aquatic Actinomycetes

Description: There were two purposes of this investigation: the first was to develop a method for studying spore germination, hyphal growth and mycelial development of the aquatic actinomycetes under the microscope so that the life cycle of this organism could be continuously followed. The second purpose was to determine the rate of carbon utilization from various types of nutritional sources, and to correlate this with the colony development and spore formation.
Date: August 1963
Creator: Shao, Yi-min
Item Type: Refine your search to only Thesis or Dissertation
open access

Attenuation of Escherichia Coli Aspartate Transcarbamoylase Expressed in Pseudomonas Aeruginosa Mutant and Wild Type Strains

Description: No apparent repression of pyr gene expression in Pseudomonas aeruginosa is observed upon addition of exogenous pyrimidines to the growth medium. Upon introduction of the subcloned Escherichia coli pyrBI genes for aspartate transcarbamoylase (ATCase) into a P. aeruginosa pyrB mutant strain, repression was observed in response to exogenously fed pyrimidine compounds. The results proved that it is possible to bring about changes in pyrimidine nucleotide pool levels and changes in transcriptional r… more
Date: December 1994
Creator: Liu, Haiyan, 1966-
Item Type: Refine your search to only Thesis or Dissertation
open access

The Autecology of Celtis Laevigata in Flood Plain Forests of Denton County, Texas

Description: This thesis describes the present nature of one facet of some of the flood plain forest stands in Denton County, Texas. The specific purpose was to demonstrate the presence or absence of difference between the Celtis laevigata (commonly known as the hackberry, southern hackberry or sugarberry) populations in stands on Denton Creek and Elm Fork of the Trinity River.
Date: January 1970
Creator: Hander, Lecil B.
Item Type: Refine your search to only Thesis or Dissertation

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
Item Type: Refine your search to only Thesis or Dissertation
open access

Autonomic Nerve Activity and Cardiovascular Function in the Chicken Embryo (Gallus gallus)

Description: The goal of this study was to build on the historic use of the avian model of development and also to further the knowledge of autonomic nervous system (ANS) regulation of cardiovascular function in vertebrates. Vasoactive drugs sodium nitroprusside, a vasodilator and phenylephrine, a vasoconstrictor were used to study the correlation of cardiovascular function relationship with nerve activity, both sympathetic and parasympathetic (vagal). Additionally, ANG II was used to assess its effects on … more
Date: December 2018
Creator: Onyemaechi, Clinton
Item Type: Refine your search to only Thesis or Dissertation
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
Item Type: Refine your search to only Thesis or Dissertation
open access

Bacterial Challenge in Lumbricus Terrestris: A Terrestrial Invertebrate Immunotoxicity Model.

Description: A bacterial challenge assay was developed utilizing the earthworm, Lumbricus terrestris, in order to assess potential immunotoxic effects from exposure to specific polychlorinated biphenyl congeners. Earthworms were inoculated with Aeromonous hydrophila, establishing a 10-day LD50. In vitro assays for effects of PCBs on phagocytosis agreed with mammalian studies, demonstrating potent suppression of phagocytosis by the non-coplanar PCB congener 138 and no suppression by the coplanar congener 12… more
Date: May 2007
Creator: McDonald, Jennifer C.
Item Type: Refine your search to only Thesis or Dissertation
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