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Water Quality Aspects of an Intermittent Stream and Backwaters in an Urban North Texas Watershed

Description: Pecan Creek flows southeast through the City of Denton, Texas. Characterized as an urban watershed, the basin covers approximately 63.5 km2. Pecan Creek is an intermittent stream that receives nonpoint runoff from urban landuses, and the City of Denton's wastewater treatment plant, Pecan Creek Water Reclamation Plant, discharges effluent to the stream. Downstream from the City of Denton and the wastewater treatment plant, Pecan Creek flows about 6,000 m through agricultural, pasture, and for… more
Date: August 2002
Creator: Taylor, Ritchie Don
Item Type: Refine your search to only Thesis or Dissertation
open access

Use of geographic information systems for assessing ground water pollution potential by pesticides in central Thailand

Description: This study employed geographic information systems (GIS) technology to evaluate the vulnerability of groundwater to pesticide pollution. The study area included three provinces (namely, Kanchana Buri, Ratcha Buri, and Suphan Buri) located in the western part of central Thailand. Factors used for this purpose were soil texture, percent slope, primary land use, well depth, and monthly variance of rainfall. These factors were reclassified to a common scale showing potential to cause groundwater co… more
Date: August 2002
Creator: Thapinta, Anat
Item Type: Refine your search to only Thesis or Dissertation
open access

Mechanisms of rapid receptive field reorganization in rat spinal cord

Description: Rapid receptive field (RF) reorganization of somatosensory neurons in the rat dorsal horn was examined using extracellular single unit recording. Subcutaneous injection of lidocaine into RFs of dorsal horn neurons results in expansion of their RFs within minutes. The expanded RFs appear adjacent to or/and proximal to original RFs. Out of 63 neurons tested, 36 (58%) show RF reorganization. The data suggest that dorsal horn of spinal cord is one of the initial sites for RF reorganization. The neu… more
Date: August 2002
Creator: Vu, Hung
Item Type: Refine your search to only Thesis or Dissertation
open access

Neuronal Network Analyses in vitro of Acute Individual and Combined Responses to Fluoxetine and Ethanol

Description: Embryonic murine neuronal networks cultured on microelectrode arrays were used to quantify acute electrophysiological effects of fluoxetine and ethanol. Spontaneously active frontal cortex cultures showed highly repeatable, dose-dependent sensitivities to both compounds. Cultures began to respond to fluoxetine at 3 µM and were shut off at 10-16 µM. EC50s mean ± S.D. for spike and burst rates were 4.1 ± 1.5 µM and 4.5 ± 1.1 µM (n=14). The fluoxetine inhibition was reversible and without effect… more
Date: August 2002
Creator: Xia,Yun
Item Type: Refine your search to only Thesis or Dissertation

Use of Satellite Imagery and GIS to Model Brood-Rearing Habitat for Rio Grande Wild Turkey Populations Occurring in the Western Cross Timbers Region of Texas

Description: Remote sensing and GIS have become standard tools for evaluating spatial components of wildlife habitats. These techniques were implemented to evaluate Rio Grande wild turkey (Meleagris gallopavo) poult-rearing habitat in the Western Cross Timbers region of Texas. Texas Parks and Wildlife (TPWD) random roving turkey counts for 1987-1989 and 1998-2000 were selected, indicating locations where hens with poults were observed. Satellite imagery from 1988 and 1999 was classified and then processed w… more
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Date: August 2002
Creator: Miller, Christopher J.
Item Type: Refine your search to only Thesis or Dissertation
open access

Landscape forest modeling of the Luquillo Experimental Forest, Puerto Rico.

Description: This thesis contributes to modeling the dynamics of forest community response to environmental gradients and disturbances over a mountain landscape. A gap model (FACET) was parameterized for species of various forest types (Tabonuco, Colorado, Dwarf and Palm), for many terrain conditions and was modified and extended to include species response to excess soil moisture and hurricanes. Landscape cover types were defined by dominance of species of each forest type and canopy height. Parameters of … more
Date: December 2002
Creator: Abbott-Wood, Chris
Item Type: Refine your search to only Thesis or Dissertation
open access

Tobacco Phospholipase D β1: Molecular Cloning and Biochemical Characterization

Description: Transgenic tobacco plants were developed containing a partial PLD clone in antisense orientation. The PLD isoform targeted by the insertion was identified. A PLD clone was isolated from a cDNA library using the partial PLD as a probe: Nt10B1 shares 92% identity with PLDβ1 from tomato but lacks the C2 domain. PCR analysis confirmed insertion of the antisense fragment into the plants: three introns distinguished the endogenous gene from the transgene. PLD activity was assayed in leaf homogenates … more
Date: December 2002
Creator: Hodson, Jane E.
Item Type: Refine your search to only Thesis or Dissertation
open access

Water Quality Mapping on Lake Texoma USA

Description: The primary objective of this study was to develop and evaluate a system capable of rapid, continuous collection of water quality and locational data on Lake Texoma. Secondary objectives included developing monthly distribution maps for chlorophyll-a, turbidity, and specific conductivity in Lake Texoma and investigating the spatial and temporal relationships between these common water quality indicators. A modified YSI multiprobe was used to develop a system capable of surveying the lake within… more
Date: December 2002
Creator: Mabe, Jeffrey A.
Item Type: Refine your search to only Thesis or Dissertation
open access

Investigation of Lead Hydrolytic Polymerization and Interactions with Organic Ligands in the Soil/Sediment-Water Environment

Description: The objective of this research was to investigate lead speciation in the soil/sediment-water environment and to better understand how the species affect lead mobility under different environmental conditions. The research involved both field soil and sediment samples as well as standard lead solutions. Field samples were fully characterized and extracted by aqueous and organic solvents. The results were compared and evaluated with the metal speciation model, MINTEQA2. Hydrolytic polymerization … more
Date: December 2002
Creator: Sanmanee, Natdhera
Item Type: Refine your search to only Thesis or Dissertation

Integrating life cycle analysis and the ecological footprint calculator to foster sustainable behaviors

Description: Many tools have been developed to assess global, national or regional sustainable development policies. However, as governments develop sustainable policies, individuals must also feel empowered to affect their personal impact on the planet. This thesis integrates three sustainability concepts that lend themselves to individual sustainability: The natural step, life cycle assessment, and the ecological footprint. TNS serves to provide the meaning and substance toward sustainable development. … more
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Date: December 2002
Creator: Anderle, Kathryn
Item Type: Refine your search to only Thesis or Dissertation
open access

Comparative biochemistry and genetic analysis of nucleoside hydrolase in Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas fluorescens.

Description: The pyrimidine salvage enzyme, nucleoside hydrolase, is catalyzes the irreversible hydrolysis of nucleosides into the free nucleic acid base and D-ribose. Nucleoside hydrolases have varying degrees of specificity towards purine and pyrimidine nucleosides. In E. coli, three genes were found that encode homologues of several known nucleoside hydrolases in protozoa. All three genes (designated yaaF, yeiK, and ybeK) were amplified by PCR and cloned. Two of the gene products (yeiK and ybeK) encode … more
Date: December 2002
Creator: Fields, Christopher J.
Item Type: Refine your search to only Thesis or Dissertation

Development, Validation, and Evaluation of a Continuous, Real-time, Bivalve Biomonitoring System

Description: A biological monitoring tool to assess water quality using bivalve gape behavior was developed and demonstrated. The purpose of this work was to develop methodologies for screening water quality appropriate to the goals of the watershed paradigm. A model of bivalve gape behavior based on prediction of behavior using autoregressive techniques was the foundation of the bivalve biomonitoring system. Current technology was used in developing the system to provide bivalve gape state data in a contin… more
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Date: December 2002
Creator: Allen, H. Joel
Item Type: Refine your search to only Thesis or Dissertation

Removal of selected water disinfection byproducts, and MTBE in batch and continuous flow systems using alternative sorbents.

Description: A study was conducted to evaluate the sorption characteristics of six disinfection byproducts (DBPs) on four sorbents. To investigate sorption of volatile organic compounds (VOCs), specially designed experimental batch and continuous flow modules were developed. The investigated compounds included: chloroform, 1,2-dichloroethane (DCE), trichloroethylene (TCE), bromodichloromethane (BDCM), methyl tertiary butyl ether (MTBE), bromate and bromide ions. Sorbents used included light weight aggregate… more
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Date: December 2002
Creator: Kadry, Ahmed Y.
Item Type: Refine your search to only Thesis or Dissertation
open access

Establishing genetic and physiological baselines for the black-tailed prairie dog (Cynomys ludovicianus).

Description: The black-tailed prairie dog (Cynomys ludovicianus) has experienced dramatic declines over much of its historical range due to habitat loss, plague, poisonings, and shootings. Many populations now occur as isolated genetic relicts. A multiple locus genetic profile was obtained using microsatellite analyses of six polymorphic nucleotide repeats from 319 black-tailed prairie dogs collected from 16 colonies throughout the state of Texas. This assessment revealed that existing populations have suff… more
Date: May 2007
Creator: Biggs, Cindy Dawn
Item Type: Refine your search to only Thesis or Dissertation
open access

A Contravention of Established Principles of Interspecific Allometric Metabolic Scaling in Developing Silkworms, Bombyx Mori.

Description: Established interspecific metabolic allometric relationships do not adequately describe the complexity and variable physiological states of developing animals. Consequently, intraspecific allometric relationships of oxygen consumption and carbon dioxide production as a function of body mass; the respiratory quotient; the function of the silk cocoon; and body composition were investigated for each distinct developmental stage of the silkworm, Bombyx mori. Whole animal O2 consumption in Bombyx r… more
Date: May 2007
Creator: Blossman-Myer, Bonnie
Item Type: Refine your search to only Thesis or Dissertation
open access

Comparison of Bare Root vs. Potted Plants, Species Selection, and Caging Types for Restoration of a Prairie Wetland, and Quantitative Analysis and Descriptive Survey of Plant Communities and Associations at Lewisville Lake Environmental Learning Area (LLELA), Lewisville, TX

Description: Lewisville Lake Environmental Learning Area (LLELA) is an 809-hectare property in Denton County, TX. A study of the vegetation community identified 466 species in 104 families, with 25% of the species from only two families, Asteraceae and Poaceae. The property demonstrates the characteristics of an early successional community, dominated by weedy species. Prairie communities are dominated by Johnson grass and ragweed, with climax tall grass prairie communities only in areas that have been plan… more
Date: May 2007
Creator: Buckallew, Robin R.
Item Type: Refine your search to only Thesis or Dissertation
open access

Hindrance of the Myosin Power Stroke Posed by the Proximity to the Troponin Complex Identified Using a Novel LRET Fluorescent Nanocircuit

Description: A novel luminescence resonance energy transfer (LRET) nanocircuit assay involving a donor and two acceptors in tandem was developed to study the dynamic interaction of skeletal muscle contraction proteins. The donor transmits energy relayed to the acceptors distinguishing myosin subfragment-1 (S1) lever arm orientations. The last acceptor allows the detection of S1's bound near or in between troponin complexes on the thin filament. Additionally, calcium related changes between troponin T and my… more
Date: May 2007
Creator: Coffee Castro-Zena, Pilar G.
Item Type: Refine your search to only Thesis or Dissertation
open access

Influence of parental swimming stamina on the cardiac and metabolic performance of larval zebrafish (Danio rerio).

Description: Superior swimming stamina in adult fish is presumably passed on to their offspring, but the ontogeny of the appearance of superior stamina and the requisite enhanced cardio-respiratory support for locomotion in larval fishes has not been determined. Is the expression of the suite of parental traits enabling superior swimming stamina in their offspring dependent upon their achieving juvenile/adult morphology, or does it appear earlier in their larvae? To answer this, adults were classified int… more
Date: May 2007
Creator: Gore, Matthew R.
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
open access

Map-based cloning of the NIP gene in model legume Medicago truncatula.

Description: Large amounts of industrial fertilizers are used to maximize crop yields. Unfortunately, they are not completely consumed by plants; consequently, this leads to soil pollution and negative effects on aquatic systems. An alternative to industrial fertilizers can be found in legume plants that provide a nitrogen source that is not harmful for the environment. Legume plants, through their symbiosis with soil bacteria called rhizobia, are able to reduce atmospheric nitrogen into ammonia, a biologic… more
Date: May 2007
Creator: Morris, Viktoriya
Item Type: Refine your search to only Thesis or Dissertation
open access

Analysis of the Expression Profiles of Two Isoforms of the Antifungal Protein Osmotin from Gossypium hirsutum

Description: The expression of two cotton osmotin genes was evaluated in terms of the mRNA and protein expression patterns in response to chemical inducers such as ethylene, hydrogen peroxide, and sodium chloride. Reverse transcriptase-polymerase chain reactions (RT-PCR) indicated that osmotin mRNAs are expressed constitutively in root tissues of cotton plants, and that they are rapidly induced in leaf and stem tissues upon ethylene treatment. Real time RT-PCR indicated that osmotin transcript levels were… more
Date: May 2007
Creator: Spradling, Kimberly Diane
Item Type: Refine your search to only Thesis or Dissertation
open access

A paleozoological perspective on predator extermination and white-tailed deer (Odocoileus virginianus Boddaert) overabundance in central Texas.

Description: Archaeological and paleontological datasets are used in conservation to add time-depth to ecology. In central Texas several top carnivores including prehistoric Native American hunters have been extirpated or have had their historic ranges restricted, which has resulted in pest-level white-tailed deer (Odocoileus virginianus texana) populations in some areas. Predator extermination has dramatically reduced the average body size of members of the extant predator guild, and large carnivores most … more
Date: May 2007
Creator: Wolverton, Steven J.
Item Type: Refine your search to only Thesis or Dissertation
open access

Evaluating Tree Seedling Survival and Growth in a Bottomland Old-field Site: Implications for Ecological Restoration

Description: In order to assess the enhancement of seedling survival and growth during drought conditions, five-hundred bare-root seedlings each of Shumard oak (Quercus shumardii Buckl.) and green ash (Fraxinus pennsylvanica Marsh.) were planted each with four soil amendments at a Wildlife Management Area in Lewisville, Texas. The treatments were a mycorrhizal inoculant, mulch fabric, and two superabsorbent gels (TerraSorb® and DRiWATER®). Survival and growth measurements were assessed periodically for two … more
Date: August 2007
Creator: Boe, Brian Jeffrey
Item Type: Refine your search to only Thesis or Dissertation
open access

Bioaccumulation of Triclocarban, Triclosan, and Methyl-triclosan in a North Texas Wastewater Treatment Plant Receiving Stream and Effects of Triclosan on Algal Lipid Synthesis.

Description: Triclosan (TCS) and triclocarban (TCC), widely used antimicrobial agents found in numerous consumer products, are incompletely removed by wastewater treatment plant (WWTP) processing. Methyl-triclosan (M-TCS) is a more lipophilic metabolite of its parent compound, TCS. The focus of this study was to quantify bioaccumulation factors (BAFs) for TCS, M-TCS, and TCC in Pecan creek, the receiving stream for the City of Denton, Texas WWTP by using field samples mostly composed of the alga Cladophor… more
Date: August 2007
Creator: Coogan, Melinda Ann
Item Type: Refine your search to only Thesis or Dissertation
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