Assessment of aquatic plant selection by waterfowl has been conducted during the winters of 1997-2000 on 49 0.2-0.79 ha research ponds in north central Texas. Ponds were categorized by dominant plant species into eight habitat types. Census with waterfowl species identification were performed to investigate impacts of aquatic vegetation and water depth on waterfowl. Eighteen waterfowl species were observed. Peak migration occurred in late December/early January. Mixed native ponds and mixed native/hydrilla ponds were the most frequently selected habitat types. The study included correlation analysis between pond water levels and waterfowl use. Full ponds received greatest use followed by half full ponds, while almost empty ponds received minimal use. Time activity budgets were conducted on waterfowl utilizing mixed native and hydrilla ponds to compare waterfowl time partitioning on native aquatic vegetation versus hydrilla. Although only minor differences were found in time budgets, social status appears to be strongly related to habitat selection. Ducks on native ponds were paired (86%), conversely no ducks on hydrilla ponds were paired. Hydrilla pond although frequently utilized, were populated by lower status birds mostly single hens.

The life history of Isonychia sicca (Walsh) was elucidated from samples collected at Clear Creek from Oct. 1976-Jun. 1978, and Elm Fork of the Trinity River from Sept. 1977-Jun. 1978, Denton County, Texas. Adaptations for existence in an intermittent stream were of primary concern. Eggs are capable of diapausing through hot, dry summers and cold, wet or dry winters. Diapause is broken in the fall after rehydration and/or in the spring. I. sicca is usually bivoltine during a Sept.-Jul. wet period. Observations from Elm Fork indicate that emergence continues to Oct. if the stream remains permanent. Considerable overlap occurs between overwintering, spring, and summer populations.

Texas water resources are under pressure due to population growth expected in the coming decades, increasing industrial demands, and frequent periods of drought. With this increasing demand for limited water resources it is important to explore alternative water sources within the State. One of those resources that can be developed is the many small aquifers which have never been well-characterized but could be an alternative source of fresh and brackish water for agriculture, municipal, and industrial applications. The natural gas industry’s demand for water is growing in Texas as new drilling techniques such a hydraulic fracturing have opened new reserves previously considered economically non-viable. The development of smaller aquifers containing brackish water is a viable alternative to the gas industry’s current reliance on fresh (potable) groundwater resources. The aquifer sections containing brackish water need to be mapped and characterized so they can be developed as an alternative water resource by the gas industry. The Barnett Shale in North-central Texas is one of the first major gas plays in the United States to use the technique of hydraulic fracturing in field development. This technique requires large quantities of water to create the required hydraulic pressure down the gas well to fracture the normally low permeability shale. A typical horizontal well completion consumes approximately 3.0 to 3.5 million gallons (11,400 to 13,200 m3) of fresh water. Projections of future groundwater demand for the Barnett Shale gas play total 417,000 AF (5.1x108 m3), an annual average of 22,000 AF (2.7x107 m3) over the expected 2007-2025 development phase. This level of water demand has the gas industry and groundwater managers exploring alternative sources of water for future development of the Barnett Shale. One alternative source of water for the expanding footprint of the Barnett Shale gas play are the smaller local Paleozoic aquifers on the western edge of the play. These small aquifers are underutilized and contain waters with higher levels of TDS. These levels are, however, acceptable to the drilling industry. In order to characterize theses aquifers, TWDB databases were utilized to analyze water chemistry and well productivity. / text

A population of the red-eared slider, Pseudemys scripta, in north central Texas was studied from 1975 to 1980. A life history energy budget was developed for a typical individual in the population and the population dynamics were estimated. A growth model relating growth rate to mean plastron length (PL) was developed from recapture data and used to 1) establish age classes and 2) age individuals. Growth rate was highly variable in both sexes. Females grew more rapidly than males and attained a larger maximum size (230 mm and 195 mm PL in females and males respectively). Females reached sexual maturity in their ninth year at a PL of 185-190 mm. Males matured in their sixth year at a PL of 90-100 mm. Females produced three clutches annually; clutch size ranged from 7 to 14 (X=10.3; N=20). Ova were enlarged in the early spring and ovulation began in late April and early May. Egg laying occurred from mid- May through June. Both egg size and clutch size increased with female body size. Lipid levels were variable within and among seasons. No annual lipid cycling pattern was evident in females. The proportion of assimilated energy devoted to reproduction, a measure of reproductive effort (RE), by females, was 13 per cent the first year of maturity (9 y) and increased to 20 per cent by their twentieth year. Lifetime RE was 16 per cent. Population density was estimated as 51 males and 50 females per ha in a 8.2-ha area of the lake. Young juveniles (less than 2 y) were not present although other subadult age classes were about equally represented. Fewer adults were encountered. An annual total production of 4000 eggs was estimated for the population present in 1977. A survival rate of from 2 to 18 per cent was estimated for the period between egg laying to 3 y. The large group of turtles younger than 10 y represented an expanding (Rₒ=1.8) lake population and the small group of older turtles were the remnants of a creek population present before Moss Lake was formed. The demographic environment, high juvenile mortality and low adult mortality, was suggested as a primary selective force shaping the life history characteristics of the Moss Lake scripta population.

Thesis (Ed. D.)--University of North Texas, May, 2007. / Title from title page display. Includes bibliographical references.

ArcView and ArcInfo were used to identify and delineate areas contaminated by fluoride, sulfate, chloride, and nitrate in the Woodbine Aquifer. Water analysis data were obtained from the TWDB from the 1950s to 1990s covering 9 counties. 1990s land use data were obtained to determine the relationship with each contaminant. Spearman's rank correlation coefficients and Kruskal-Wallis tests were used to calculate relationships between variables. Land uses had little effect on distributions of contaminants. Sulfate and fluoride levels were most problematic in the aquifer. Depth and lithology controlled the distributions of each contaminant. Nitrate patterns were controlled mainly by land use rather than geology, but were below the maximum contaminant level. In general, contaminant concentrations have decreased since the 1950s.

This research is an investigation of the Late Holocene technological transition from the spearthrower and dart to the bow and arrow in north central Texas. It is conducted through a theoretical approach that utilizes ethnographic research, experimental archaeology and the archaeological record to elucidate differences in the behaviors and hunting strategies of Late Archaic and Late Prehistoric groups. It first confirms that there was a transition. Second, a lithic analysis demonstrates that there are fundamental differences in the sizes of the stone dart and arrow points that relate to the propulsive requirements of the weapon systems. Third, it is shown these size differences constrain maintenance potentials and that indeed dart and arrow points exhibit stark differences in their life histories in spite of being employed for the same task. And finally, the faunal record suggests that this transition was associated with an increase in foraging efficiency.

The problem of this study was to determine the effect of academic self-concept, student aspiration, intellectual achievement responsibility, and certain other personal factors on the attendance patterns of selected ninth grade students, and to develop from data on all factors a typical profile of conditions likely to result in high absenteeism and make recommendations for initial steps in remediation. As a result of the statistical analysis and subsequent retention or rejection of the null hypotheses, the significant findings of this study may be summarized as follows. (1) Ninth grade attenders are significantly younger than non-attenders. (2) Attenders had more siblings than non-attenders. (3) Attenders are significantly more involved in school organizations than non-attenders. (4) There is a higher frequency in suspensions among non-attenders. Based on analysis of the findings of this study and within the limitations of the population described in the procedure section, the following conclusions were formulated. (1) Students who have been retained, started school later, or for some reason are older than their classmates, are more likely to attend school irregularly.(2) Educators cannot expect to find the major causes of student absenteeism to be academic self-concept, intellectual achievement responsibility, or student aspiration. (3) Family size may be an important consideration for educators to investigate when working with school non-attenders. (4) School attenders can be expected to be actively involved in the co-curricular elements of the school program. (5) Higher rates of student suspensions are more likely to increase attendance problems rather than reduce them. (6) How students use their time outside the school day is not likely to be the crucial factor in school attendance. (7) While students often complain about schedules, teacher selection, and proximity of friends, it is not likely that changes in these factors would influence student attendance.

This study examined what differences in resiliency traits, if any, exist between successful and non-successful first and continuing-generation college students through the use of a survey. For the purposes of this study, first-generation students were those students whose parents have never attended college and continuing-generation college students were those students whose parents have attended some college. For the purposes of this study, the term successful was defined as those students who after being enrolled during fall 2005 re-enrolled for the spring 2006 semester and the term non-successful is defined as those students who after being enrolled fall 2005 semester failed to re-enrolled for the spring 2006 semester. A sample of 164 students was surveyed by collecting demographic data, resiliency traits, attitudinal characteristics, level of familial support, and reasons for dropping out of college. A sub-sample of 40 students participated in a face-to-face, in-depth interview. This study found that successful first-generation community college students possessed certain common qualities or resilient characteristics that include: 1) social competence, 2) problem-solving skills, 3) critical consciousness, 4) autonomy, and 5) sense of purpose. Through the face-to-face interviews common themes emerged. Many of the students used similar words to describe their feelings and experiences about beginning, continuing and withdrawing from college. Many of the first-generation college students expressed the lack of familial support once they enrolled. Common themes emerged for the continuing-generation college students in that each student was comfortable with the process of selecting a major, selecting courses to enroll in, and the amount of time they expected to devote to studying. The return rate for each of the four groups studied was limited and rigorous follow up efforts failed to increase the return rate. This is a fundamental limitation of the study, and the results can only be generalized to the institution studied. However, the findings in this study are consistent with the literature on retention and dropout rates for these students.

The September 11 terrorist attacks pointed out the lack of information sharing between law enforcement agencies as a potential threat to sound law enforcement in the United States. Therefore, many law enforcement agencies as well as the federal government have been initiating information sharing systems among law enforcement agencies to eradicate the information sharing problem. One of the systems established by Homeland Security is the North Central Texas Fusion Center (NCTFC). This study evaluates the NCTFC by utilizing user acceptance methodology. The unified theory of acceptance and the use of technology is used as a theoretical framework for this study. Within the study, user acceptance literature is examined and various models and theories are discussed. Furthermore, a brief information regarding the intelligence work done by law enforcement agencies are explained. In addition to the NCTFC, several major law enforcement information systems are introduced. The data for this study comes from the users of the NCTFC across the north central Texas region. Surveys and interviews are used to triangulate data. It is found in this study that performance expectancy and effort expectancy are important indicators of system use. Furthermore, outreach and needs assessment are important factors in establishing systems. The results of the study offer valuable input for NCTFC administrators, law enforcement officials, and future researchers.