Spatial and Temporal Patterns of Areal and Volumetric Phytoplankton Productivity of Lake Texoma (open access)

Spatial and Temporal Patterns of Areal and Volumetric Phytoplankton Productivity of Lake Texoma

Phytoplankton productivity of Lake Texoma was measured for one year from August 1999 to August 2000 for four stations, using the oxygen change method and laboratory incubation. Mean values of the photosynthetic parameters, PBmax and alphaB ranged from 4.86 to 46.39 mg O2.mg Chl-1.hr-1 for PBmax and 20.06 to 98.96 mg O2.mg Chl-1.E-1.m2 for alphaB. These values were in the range to be expected for a highly turbid, temperate reservoir. Estimated gross annual areal productivity ranged from 594 g C.m2.yr-1 (P.Q. = 1.2), at a station in the Washita River Zone to 753 g C.m2.yr-1 at a station in the Red River Zone, of the reservoir. Gross annual areal productivity at Station 17, in the Main Lake Zone, was 708 g C.m2.yr-1. Gross areal and volumetric productivity showed distinct seasonal variation with Photosynthetically Available Radiation (PAR) and temperature. Trophic status estimated on a station-by-station basis, using net productivity values derived from gross productivity and respiration estimates, was mesotrophic for all the stations, though one station approached eutrophy. Net productivity values ranged from 0.74 to 0.91 g C. m-2.d-1. An algal bioassay conducted at two stations in August 2000, revealed that phosphorus was most likely the nutrient limiting photosynthesis at both …
Date: August 2001
Creator: Baugher, Tessy
System: The UNT Digital Library
Characteristics of Community Service Programs and Probationers in Texas (open access)

Characteristics of Community Service Programs and Probationers in Texas

As a criminal sanction, community service involves unpaid labor on the part of convicted criminal offenders. Community service was created as an alternative to incarceration for low-level offenders. It now appears, however, that community service is rarely used as a true alternative to prison, but rather as an added condition of probation. The body of research on community service in the United States is modest, so relatively little is known about its characteristics and administration. Data were attained from 88 Texas probation professionals via self-administered written surveys in an effort to gather information about the use of community service as a criminal sanction in Texas. Frequency distribution analyses identified characteristics of both community service programs and offender participants in Texas.
Date: August 2002
Creator: Roberts, Darrin David
System: The UNT Digital Library
Recovery of the Fish Population of a Municipal Wastewater Dominated, North Texas Creek After a Major Chlorine Disturbance (open access)

Recovery of the Fish Population of a Municipal Wastewater Dominated, North Texas Creek After a Major Chlorine Disturbance

This study evaluated the effects of a major chlorine disturbance on fish communities in Pecan creek by the City of Denton's Pecan Creek Water Reclamation Plant. Fish communities in Pecan Creek were sampled using a depletion methodology during February, April, July, and November, 1999. February and April sampling events showed that the fish communities were severely impacted by the chlorine. Sampling during July and November showed fish communities recovered in Pecan Creek. The first-twenty minutes of shocking and seining data were analyzed to mirror an equal effort methodology. This methodology was compared to the depletion methodology to see if the equal effort methodology could adequately monitor the recovery of Pecan Creek after the chlorine disturbance. It was determined that the equal effort methodology was capable of monitoring the recovery of Pecan Creek, but could not accurately represent the fisheries community as well as the depletion method. These data using the twenty-minute study were compared to a previous study. Results of this study were similar to those found in a previous study, although fish communities were more severely impacted and took longer to recover.
Date: August 2002
Creator: Maschmann, Gerald F.
System: The UNT Digital Library
Assessing the Spatial and Temporal Distribution of MTBE and BTEX Compounds in Lake Lewisville, Texas February 1999 - February 2000 (open access)

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

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 Regional Water District (UTRWD) Treatment Plants were also tested for MTBE and BTEX. MTBE and BTEX were not detected in UTRWD water samples. Denton's finished water samples never exceeded 2.2 mg/L for MTBE and BTEX was not detected except for one replicate of 1.1 mg/L toluene.
Date: August 2000
Creator: Lee, Anne W.
System: The UNT Digital Library
Spatial and Temporal Influences of Water Quality on Zooplankton in Lake Texoma (open access)

Spatial and Temporal Influences of Water Quality on Zooplankton in Lake Texoma

Seventy-one aquatic species including the copepodids and nauplii were identified from Lake Texoma from August 1996 to September 1997. Zooplankton community structure, abundance and spatial and temporal distributions were compared among five lake zones delineated a priori based on chloride concentration. The zones, in order of decreasing chloride concentration, are the Red River zone (RRZ), Red river Transition zone (RRTZ), Main Lake zone (MLZ), Washita River Transition zone (WRTZ) and Washita River zone (WRZ). Bray Curtis Similarity Index showed community structure was most similar in the two Red River arm zones, the two Washita River arm zones and the MLZ. Zooplankton abundance was greatest in the Red River arm (312 org/L), intermediate in the Washita River arm (217 org/L) and least in the Main Lake body (103 org/L). A significant increase in the abundance of a deformed rotifer, Keratella cochlearis, was observed mainly in the Red River arm during a second study from March 1999 to June 1999. Seasonal dynamics, rather than spatial dynamics, were more important in structuring the zooplankton community, especially in the two river arms. Spatial variance was solely attributed to station and zone effects independent of time for a few crustacean species and many of the …
Date: May 2000
Creator: Franks, Jessica L.
System: The UNT Digital Library

Characterizing the Municipal Solid Waste Stream in Denton, Texas

Access: Use of this item is restricted to the UNT Community
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" source category had more paper than any of the other five categories. Based on these findings, an incrementally aggressive approach is recommended to reduce certain types of wastes observed in the waste stream. This would include a Pay-As-You-Throw Program followed by an Intermediate Processing Center that can be converted to a Materials Recovery Facility.
Date: August 2000
Creator: Brady, Patricia D.
System: The UNT Digital Library

Life History and Case Building Behaviors of Phylloicus ornatus (Banks) (Trichoptera: Calamoceratidae) In Two Spring Fed Tributaries in the Central Edwards Plateau Bioregion of Texas

Access: Use of this item is restricted to the UNT Community
The life history and case-making behaviors of Phylloicus ornatus from two springfed first order streams in the Edwards Plateau Bioregion of Texas were studied from January 1998 to November 1999. Field larval, pupal and adult samples and laboratory rearings indicated a multivoltine cycle. First instars differ from late instars in number of labral setae and in having a unique spur-like claw on each lateral hump. Larval development was asynchronous with second through fifth instars and pupae present most months. First instars were present April through July, October and November. Case making of first instar and case reconstruction of later instars extracted from their cases was documented by videophotography.
Date: August 2000
Creator: Norwood, James Christopher
System: The UNT Digital Library
Hydrological Impacts of Urbanization: White Rock Creek, Dallas Texas (open access)

Hydrological Impacts of Urbanization: White Rock Creek, Dallas Texas

This research project concerns changes in hydrology resulting from urbanization of the upper sub-basin of the White Rock Creek Watershed in Collin and Dallas Counties, Texas. The objectives of this study are: to calculate the percent watershed urbanized for the period of 1961 through 1968 and the period of 2000 through 2005; to derive a 1960s average unit hydrograph and a 2000s average unit hydrograph; and, to use the two averaged hydrographs to develop a range of hypothetical storm scenarios to evaluate how the storm response of the watershed has changed between these two periods. Results of this study show that stormflow occurs under lower intensity precipitation in the post-urbanized period and that stormflow peaks and volumes are substantially larger compared to the pre-urbanized period. It is concluded that changes in watershed surface conditions resulting from urbanization have lowered the precipitation-intensity threshold that must be surpassed before storm run-off is generated.
Date: December 2005
Creator: Vicars, Julie Anne Groening
System: The UNT Digital Library
Contextualizing the Law: Sentencing Decisions of Sexual Assault Cases of Dallas County, 1999-2005 (open access)

Contextualizing the Law: Sentencing Decisions of Sexual Assault Cases of Dallas County, 1999-2005

The incidence of sexual assault inundates the courts with many cases each year. Given the unique nature of the crime, judges and juries are faced with an array of different scenarios to which they are required to make fair, justifiable and consistent decisions. I examine child sexual assault cases of Dallas County 1999-2005, I look at both legal and extralegal factors including case characteristics, institutional characteristics and characteristics of the defendants and the victims. First, I examine the impact of the independent variables on sentence length using regression analysis to determine influences on sentencing for judges and juries. Second, I examine the same factors using Probit analysis to determine which characteristics make a life sentence more probable for those decision-makers.
Date: December 2006
Creator: Greening, Megan
System: The UNT Digital Library
Health Status and Access Disparities Among the Uninsured Working-Age Population in a Safety-Net Healthcare Network in Tarrant County, Texas (open access)

Health Status and Access Disparities Among the Uninsured Working-Age Population in a Safety-Net Healthcare Network in Tarrant County, Texas

The objective of this research was to determine if healthcare access disparities exist across race and gender in a publically funded safety-net healthcare system in Texas. Data were examined from a representative random sample of 1468 adults aged 18-64 who were patients in this safety-net system in July and August of 2000 and were analyzed using binary logistic regression and chi-square measures of significance. Major Findings: On measures of health status - overall health rating (p =.051), limited employment (p =.000), energy level (p =.001), and worry (p =.012) - Anglos reported the worst health; Mexican Americans, the best health; with African Americans intermediate. Mexican Americans were more likely to have never had health insurance, and to also have had insurance in the past year; Anglos were least likely to have ever had insurance (p =.015) or to have had insurance in the past year (p =.000). On use of EDs (p =.028), problems getting prescription medicines (p =.029), and foregoing other necessities of life to pay for healthcare, Mexican Americans were least disadvantaged with African Americans reporting greatest use of EDs among both men and women, and Anglos the most problems with prescription medicines and foregoing care, especially among …
Date: December 2009
Creator: Queen, Courtney M.
System: The UNT Digital Library
What Went Wrong?  How Arrogant Ignorance and Cultural Misconceptions Turned Deadly at the San Antonio Courthouse, March 19, 1840 (open access)

What Went Wrong? How Arrogant Ignorance and Cultural Misconceptions Turned Deadly at the San Antonio Courthouse, March 19, 1840

Although the Council House Fight is well written about in the annals of early Texas history, this all-encompassing study will reveal a whole new picture. Unlike previous works that maintained one point of view, multiple perspectives were analyzed and explored to allow a more comprehensive view of the Council House Fight to emerge. Primary focus on social and cultural misunderstandings, as well as the mounting hostility between the Penateka Comanche and Texians across the frontier, will demonstrate their general distrust and hatred of the other. Detailing their complicated relationship will prove that neither the Texians nor the Comanche were without blame, and both shared responsibility for the deterioration of events on and before March 19, 1840.
Date: May 2008
Creator: Copeland, Cristen Paige
System: The UNT Digital Library