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open access

N-Acylethanolamine (NAE) Profiles Change During Arabidopsis Thaliana Seed Germination and Seedling Growth

Description: An understanding of the potential roles as lipid mediators of a family of bioactive metabolites called N-acylethanolamines (NAEs) depends on their accurate identification and quantification. The levels of 18C unsaturated NAEs (e.g. NAE18:2, NAE 18:3, etc.) in wild-type seeds (about 2000 ng/g fw) generally decreased by about 80% during germination and post-germinative growth. In addition, results suggest NAE-degradative fatty acid amide hydrolase (FAAH) expression does not play a major role in … more
Date: August 2006
Creator: Wiant, William C.
Item Type: Refine your search to only Thesis or Dissertation
open access

Analysis and Development of Post Secondary Curriculum on Sustainability

Description: This thesis examines existing curricula at colleges and universities about sustainability and uses results to develop an introductory post secondary course curriculum. The proposed course is organized around three major elements - - science, philosophy, and economics - - all integral to understanding sustainability. Materials needed to teach the proposed 3-semester hour course including syllabus, teaching modules, transparencies, handouts, and exams were developed. Suggestions on how to teach a… more
Date: May 2000
Creator: White, Miki Machell
Item Type: Refine your search to only Thesis or Dissertation
open access

Analysis of the One-Horned Rhinoceros (Rhinoceros Unicornis) Habitat in the Royal Chitwan National Park, Nepal.

Description: This study analyzes the remaining suitable habitat of the one-horned rhinoceros, Rhinoceros unicornis, in Royal Chitwan National Park of Nepal. An April 2003 Landsat image was classified into eight land cover types: wetland, sand, water, mixed forest, sal forest, agriculture, settlement, and grassland. This image was converted into habitat suitability maps using cover, food, and water. The rhinoceros prefers grassland habitat with oxbow lakes and closed canopy during the monsoon season. Nomina… more
Date: December 2005
Creator: Thapa, Vivek
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

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

Assessing Outcomes of a Recycling Education and Service Program within an Elementary School

Description: During the spring 2004 a pilot school recycling program was implemented within Robert E. Lee Elementary. The primary goal of the program was to determine how recycling education in the school would affect curbside recycling rates within the surrounding community. The program was a cooperative effort between the University of North Texas, City of Denton Solid Waste Department and Keep Denton Beautiful. Throughout the first months of the study during the spring 2004, an increase in curbside rec… more
Date: August 2005
Creator: Cunningham-Scott, Carey Beth
Item Type: Refine your search to only Thesis or Dissertation
open access

Assessing the Spatial and Temporal Distribution of MTBE and BTEX Compounds in Lake Lewisville, Texas February 1999 - February 2000

Description: The spatial and temporal distribution of Methyl Tertiary-Butyl Ether (MTBE) and BTEX (Benzene, Toluene, Ethylbenzene, Xylenes) compounds were assessed in a multipurpose reservoir, Lake Lewisville, Texas between February 1999 and February 2000. Concentrations of MTBE ranged from 0.0 - 16.7 mg/L. Levels of MTBE in the lake were related to watercraft. BTEX concentrations were never detected above 2.0 mg/L during the sampling period. Finished drinking water from Denton and the Upper Trinity Regio… more
Date: August 2000
Creator: Lee, Anne W.
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

Bacterial Cyanide Assimilation: Pterin Cofactor and Enzymatic Requirements for Substrate Oxidation

Description: Utilization of cyanide as the sole nitrogen source by Pseudomonas fluorescens NCIMB 11764 (Pf11764) occurs via oxidative conversion to carbon dioxide and ammonia, the latter satisfying the nitrogen requirement. Substrate attack is initiated oxygenolytically by an enzyme referred to as cyanide oxygenase (CNO), which exhibits properties of a pterin-dependent hydroxylase. The pterin requirement for Pf11764 CNO was satisfied by supplying either the fully (tetrahydro) or partially (dihydro) reduced … more
Date: May 2004
Creator: Dolghih, Elena
Item Type: Refine your search to only Thesis or Dissertation

Characterizing the Municipal Solid Waste Stream in Denton, Texas

Description: Forty-two commercially collected dumpsters from Denton’s Municipal Solid Waste Stream were emptied, sorted and weighed to characterize the material types and make preliminary recycling policy recommendations. The general composition of Denton’s solid waste stream was not significantly different from the composition of the nation’s solid waste stream. Fifty-eight percent of the observed waste stream was recyclable. Paper made up the largest portion of recyclable materials and the "grocery" sourc… more
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Date: August 2000
Creator: Brady, Patricia D.
Item Type: Refine your search to only Thesis or Dissertation
open access

Coelomic Fluid Protein Profile in Earthworms Following Bacterial Challenge.

Description: Proteomic techniques were used to evaluate the protein profile of the earthworm, (Lumbricus terrestris), following a bacterial challenge. One control group received no injection; a second control group received injections of phosphate buffer solution (PBS). The experimental group received injections of PBS containing (Aeromonas hydrophila). After incubation for 12 hours at 20°C, coelomic fluid was collected from each group for analysis by 2-D electrophoresis. There were significant differences… more
Date: December 2006
Creator: Brooks, Geoffrey Lance
Item Type: Refine your search to only Thesis or Dissertation
open access

College Freshman Biology Two Semester Course: Integrating Deep Processing Teaching Techniques

Description: Development of a college level freshman biology course was undertaken in response to government reports that American students have fallen behind students of other countries in the area of the sciences. Teaching strategies were investigated to accomplish two objectives, to define essential academic material to include in the course and to investigate teaching techniques that would increase deep processing of the information. An active process that consisted of applying the cognitive information… more
Date: May 2002
Creator: Blevins, Mary Jean
Item Type: Refine your search to only Thesis or Dissertation

Comparative Bioavailability of Dietary and Dissolved Cadmium to Freshwater Aquatic Snails

Description: Heavy metal bioaccumulation in aquatic organisms may occur through direct or indirect uptake routes. Research indicates that the significance of uptake route varies with contaminant and organism exposed. The relative importance of different metal sources in aquatic systems was investigated by exposing freshwater snails to dietary or dissolved sources of cadmium. Snails were exposed to control, contaminated food only, contaminated water only, and contaminated food and water treatments. During… more
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Date: December 2003
Creator: White, Jessica C.
Item Type: Refine your search to only Thesis or Dissertation

Comparison of GPS Point Selection Methods for GIS Area Measurement of Small Jurisdictional Wetlands

Description: U.S. Army Corps of Engineers (USACE) regulates fill of jurisdictional waters of the United States including wetlands. Recent USACE regulations set a threshold of impacts to wetlands at one-half acre. Impact area can be determined by Global Positioning System (GPS) measurement of wetland boundary and Geographic Information System (GIS) calculation of impact area. GPS point selection methods include (1) equal time interval, (2) transect and (3) intuition. Four two-acre shapes were measured with e… more
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Date: August 2001
Creator: Shelton, Michael
Item Type: Refine your search to only Thesis or Dissertation
open access

Concentration-dependent Effects of D-Methylphenidate on Frontal Cortex and Spinal Cord Networks in vitro

Description: Spontaneously active frontal cortex and spinal cord networks grown on microelectrode arrays were used to study effects of D-methylphenidate. These central nervous system tissues have relatively low concentrations of dopaminergic and noradrenergic neurons compared to the richly populated loci, yet exhibit similar neurophysiological responses to methylphenidate. The spontaneous spike activity of both tissues was inhibited in a concentration-dependent manner by serial additions of 1-500 µM methylp… more
Date: December 2004
Creator: Miller, Benjamin R.
Item Type: Refine your search to only Thesis or Dissertation
open access

Concentrations of Triclosan in the City of Denton Wastewater Treatment Plant, Pecan Creek, and the Influent and Effluent of an Experimental Constructed Wetland

Description: The Pecan Creek Waste Reclamation Plant in Denton, Texas, an activated sludge WWTP, was sampled monthly for ten months to determine seasonal and site variation in concentrations of triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol), an antibacterial additive. SNK separation after the highly significant ANOVA on ranked data were: summer = fall > winter = spring and influent > downstream = effluent = wetland inflow > wetland outflow (a=0.05). After the plant converted to ultraviolet disinfection… more
Date: August 2004
Creator: Waltman, Elise Lyn
Item Type: Refine your search to only Thesis or Dissertation
open access

Correspondence Between Aquatic Ecoregions and the Distribution of Fish Communities of Eastern Oklahoma

Description: I assessed fish community data collected by the Oklahoma Conservation Commission from 82 minimally impaired wadeable reference streams in eastern Oklahoma to determine whether existing aquatic ecoregions provide the best framework for spatial classification for the development of biological assessment methods and biocriteria. I used indirect ordination and classification to identify groups of sites that support similar fish communities. Although correspondence was observed between fis… more
Date: May 2001
Creator: Howell, Charles E.
Item Type: Refine your search to only Thesis or Dissertation

Culturing Vallisneria americana for Restoration Efforts

Description: Robust Vallisneria americana was cultured for restoration purposes. Preliminary studies, with various iron treatments, were conducted to ascertain the amount of phosphorous release into the water column from sediments. There was a significant difference in the amount of phosphorous released if commercial sediment was used with a low iron amendment or without an iron amendment. The second study consisted of planting V. americana on two different sediment types while supplying half of the pla… more
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Date: May 2004
Creator: Tanski, Erin M.
Item Type: Refine your search to only Thesis or Dissertation
open access

Density, Distribution and Habitat Requirements for the Ozark Pocket Gopher (Geomys Bursarius Ozarkensis)

Description: A new subspecies of the plains pocket gopher (Geomys bursarius ozarkensis), located in the Ozark Mountains of north central Arkansas, was recently described by Elrod et al. (2000). Current range for G. b. ozarkensis was established, habitat preference was assessed by analyzing soil samples, vegetation and distance to stream and potential pocket gopher habitat within the current range was identified. A census technique was used to estimate a total density of 3, 564 pocket gophers. Through automo… more
Date: May 2004
Creator: Kershen, Audrey Allbach
Item Type: Refine your search to only Thesis or Dissertation

Determination of Dissociation Constants for GABAA Receptor Antagonists using Spontaneously Active Neuronal Networks in vitro

Description: Changes in spontaneous spike activities recorded from murine frontal cortex networks grown on substrate-integrated microelectrodes were used to determine the dissociation constant (KB) of three GABAA antagonists. Neuronal networks were treated with fixed concentrations of GABAA antagonists and titrated with muscimol, a GABAA receptor agonist. Muscimol decreased spike activity in a concentration dependent manner with full efficacy (100% spike inhibition) and a 50% inhibitory concentration (IC50)… more
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Date: December 2005
Creator: Oli-Rijal, Sabnam
Item Type: Refine your search to only Thesis or Dissertation
open access

Determination of Habitat Preferences of Pronghorn (Antilocapra americana) on the Rolling Plains of Texas Using GIS and Remote Sensing

Description: The Rocker b Ranch on the southern Rolling Plains has one of the last sizeable populations of pronghorn (Antilocapra americana) in Texas. To investigate habitat utilization on the ranch, pronghorn were fitted with GPS/VHF collars and were released into pastures surrounded by a variety of fences to determine how fence types affected habitat selection. Habitat parameters chosen for analysis were vegetation, elevation, slope, aspect, and distances to water, roads, and oil wells. Results showed … more
Date: May 2005
Creator: Aiken, Robin A.
Item Type: Refine your search to only Thesis or Dissertation

Development of a Pre-Impact Environmental Site Characterization for the Bryan Mound, Texas Strategic Petroleum Reserve

Description: This thesis presents a model for developing site-specific contingency plans to be used during spill response, remediation, and post-spill monitoring using the Strategic Petroleum Reserve's Bryan Mound site as a case study. Bird and vegetation observations provide baseline data for biological conditions, and sediment sampling for total petroleum hydrocarbons serves as a chemical component of the model. Results demonstrate previously unknown conditions that would hinder remediation and affect the… more
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Date: December 2001
Creator: Hernandez, Sylvia A.
Item Type: Refine your search to only Thesis or Dissertation
open access

Developmental Patterns of Metabolism and Hematology in the Late Stage Chicken Embryo (Gallus Domesticus) at Two Incubation Temperatures.

Description: How temperature affects physiological development in the chicken embryo is unknown. Embryos incubated at 38°C or 35°C showed no difference in growth or survival. The time to hatching was longer in 35°C than 38°C embryos (23.7 vs. 20.6 days), but unaffected was the relative timing of appearance of developmental landmarks (internal, external pipping). At stage 43-44, 38°C embryos maintained oxygen consumption around 1 mL/g/h despite acute temperature reduction (suggesting thermoregulatory maturat… more
Date: May 2003
Creator: Black, Juli
Item Type: Refine your search to only Thesis or Dissertation
open access

Effector Response of the Aspartate Transcarbamoylase From Wild Type Pseudomonas Putida and a Mutant with 11 Amino Acids Deleted at the N-terminus of PyrB.

Description: Like its enteric counterpart, aspartate transcarbamoylase (ATCase) from Pseudomonas putida is a dodecamer of two different polypeptides. Unlike the enterics, the Pseudomonas ATCase lacks regulatory polypeptides but employs instead inactive dihydroorotases for an active dodecamer. Previous work showed that PyrB contains not only the active site but also the effector binding sites for ATP, UTP and CTP at its N-terminus. In this work, 11 amino acids were deleted from the N-terminus of PyrB and t… more
Date: May 2002
Creator: Asfour, Hani
Item Type: Refine your search to only Thesis or Dissertation
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