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 the ATCase with the truncated protein was expressed in E. coli pyrB- and purified. The wild type enzyme was similarly treated. Velocity-substrate plots without effectors gave Michaelis-Menten kinetics in all cases. Deleting 11 amino acids did not affect dodecameric assembly but altered effector responses. When carbamoylphosphate was varied, the mutant enzyme was inhibited by UTP while the wild type enzyme was activated 2-fold. When the aspartate was varied, CTP had no effect on the mutant enzyme but strongly inhibited the wild type enzyme.

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 to solving problems or developing answers to questions was defined as critical thinking. Critical thinking was incorporated into the course by the use of case studies.

A life history and productivity study of Enallagma civile was conducted in a playa that was located in the southern High Plains of Texas. Other odonates were also studies to identify their contributions to the habitat.

This study examined the relationship between selective serotonin reuptake inhibitor (SSRI) medication and auditory measures in clinically depressed women. Experimental subjects were tested in both a medicated and unmedicated condition. Experimental subjects were compared to a normal control group; additionally intrasubject comparison was made within the experimental group. Test measures included: audiometry, tympanometry, otoacoustic emissions, uncomfortable loudness level, masking level difference, SCAN-A, Synthetic Sentence Identification (SSI), and the low predictability section of the Revised Speech in noise (RSPIN). The unmedicated group scored significantly less favorably than the control group on the following tests; SCAN-A (composite, filtered words, and auditory figure ground), R-SPIN (0MCR condition in both the right and left ears). Additionally, the unmedicated group scored significantly less favorably than the medicated group on the SSI (-20MCR condition right ear only) and of the R-SPIN (0MCR condition right ear only). Other test measures indicated consistent trends but did reach significance.

This paper documents the execution and exhibition of a group of oil paintings exploring themes of spectacle and the construction of reality in contemporary American society. The paintings are composed of figures and fragments of text originating in stills taken from television news and reality TV. This paper describes and assesses the paintings according to a set of questions developed by the artist at the inception of the project. Various strategies employed in the execution of the work are analyzed and compared. The contribution of this project to the field of contemporary visual art is evaluated via comparison with other art, past and present, expressing similar concerns.

Scratch recovery is a desirable property of many polymer systems. The reason why some materials have demonstrated excellent scratch recovery while others do not has been a mystery. Explaining the scratch resistance based upon the hardness of a material or its crosslink density is incorrect. In this thesis, novel polymers were tested in an attempt to discover materials that show excellent scratch recovery - one of the most important parameters in determining the wear of a material. Several hypotheses were developed in an attempt to give an accurate picture of how the chemical structure of a polymer affects its scratch recovery. The results show that high scratch recovery is a complex phenomenon not solely dependent upon the presence of electronegative atoms such as fluorine.

This paper analyzes stock index reactions to interest rate actions by the FOMC. Unlike previous analyses this study utilizes macro-economic indicators and accounts for pre-decision market expectations. Results indicate significant reaction of the stock market to the actions of the FOMC regardless of interest rate actions matching pre-decision market expectations. Binary dummy variables representing the five days following an FOMC meeting indicate a significant reaction for days one; two and three of the Dow Jones model and for day five of the NASDAQ model. The magnitude of the coefficients are 0.17%, 0.09%, -0.07% and -.15% respectively. These findings may be sensitive to a priori choices regarding the definition of the market expectation variable.

I have been working with horses as imagery for about seven years and my problem in lieu of thesis continued along this vein by researching the roles of the horse in history, specifically mobility, and developing work that creates visual links between the past and present roles of horses. I am a printmaker and the work involved in the project consists of prints that use layers of related images and juxtaposition of unrelated images to accomplish my goals of cohesion between horses and the machinery that has replaced them. As the project developed the links between past and present society became my impetus rather the horse and mobility, and my future work will respond to this.

The purpose of this study was to investigate the relationship between selective serotonin reuptake inhibitor (SSRI) medication on auditory skills in clinically depressed subjects. Experimental subjects prescribed an SSRI were tested in a medicated and an unmedicated condition, and the test results were compared. Furthermore, the experimental group was compared with a control group consisting of normal subjects. Test measures included pure tone audiometry, tympanometry, acoustic reflex thresholds, and auditory electrophysiologic measures such as auditory brainstem and auditory late responses. An assessment scale for depression (Beck Depression Inventory-II) was also used. Results indicated statistically significant differences for the BDI-II between the control and experimental groups for both conditions. Electrophysiologic measures indicated a significantly shorter latency for auditory late potential P1 at 55 dBnSL, and a significantly larger amplitude at 45 dBnSL for the N1/P2 component for the unmedicated group. Although the other measures showed trends, they did not reach significance.

This thesis explains the stories and concepts behind each piece that was discussed on the opening night of my MFA Exhibition. The works, entitled Film Noir, Brains, Trains, and Beer, The Boy Next Door, Peterbuilt, and 10-50, H-1, was discussed more specifically and in greater detail. Speaking in public has always been a difficult task, especially on the subject of my art. My images deal with the highly intense subject matter of violence inflicted onto others as a result of human social behaviors. These vile social behaviors are translated into colorful and humorous lithographs, etchings, and drawings. These images are displayed to the public for individual interpretation. This thesis discusses audience interpretation before the literal meaning is revealed, how much information should be revealed to the viewer, and how this information manipulates the aesthetics of the piece.

Competency to stand trial cases constitute the largest percentage of forensic referrals for clinical psychologists. Furthermore, research suggests that the use of forensic measures facilitates the decisions of competency made by forensic examiners. This study investigated the construct validity of three competency measures: (a) the GCCT-MSH, (b) the MacCAT-CA, and (c) the ECST with 100 adult males incarcerated at the Tarrant County Jail in Fort Worth, TX. Construct validity was investigated via the use of a multitrait-multimethod research design for the three-prong conceptualization of the Dusky standard. Results indicated that current competency measures do an adequate job of assessing for factual understanding, but lack construct validity for two prongs: rational understanding and the ability to consult with counsel. In addition, the atypical presentation scales of the both GCCT and the ECST performed well at screening individuals for feigning. Finally, prediction of competency from clinical variables was also investigated. Psychotic symptoms and overall impairment were the strongest predictors of incompetency.

This study examines the concepts of social style and gender to determine if a relationship exists between the two constructs. The hypotheses suggested a direct relationship between the categories of the BSRI (masculine, feminine, androgynous, and undifferentiated) and the Social Style Analysis (driver, amiable, expressive, and analytical). Ninety-four participants completed two self-report surveys. Chi-square analysis performed on the data found a significant relationship between feminine and amiable as well as androgynous and expressive. While the analysis suggested that masculine/driver and undifferentiated/analytical were not independent, the relationship found was not significant.

The theoretical model of Beratan and Onuchic predicts a large attenuation of ET rates through hydrogen bonds; however, the effect of individual hydrogen bond on electron transfer reaction has not been systematically studied. The organic complexes in this study are a series of crown ether/ammonium salt, which incorporate a redox partner on each component of the complex. The dimethoxynaphthalene redox donor was attached to the crown ether and a series of ammonium salts was synthesized which bear substituted quinone and naphthoquinone acceptor. The complexes characterization and preliminary electron transfer rate measurement were completed with UV/Vis and steady-state emission spectroscopy.

A comprehensive measurement system was developed to monitor play in children with autism and typically developing children. The study was conducted in a preschool operated in conjunction with a center-based program for children with autism. The development of the measurement system was based on observations of four children with autism and three typically developing children during social and play activites. Data were collected on material use and several dimensions of play: Simple Manipulation, Functional Manipulation, Symbolic Toy Play, Symbolic Role Play and Play Themes. The results indicated that the measurement system consistently measured a wide range of play behaviors across children and materials. Significance of the information gathered from the measurement system in assessing play and designing interventions is discussed.

Discriminant analysis is a procedure for identifying the relationships between qualitative criterion variables and quantitative predictor variables. Data bases of genetic polymorphisms are currently available that group such polymorphisms by ethnic origin or nationality. Such information could be useful to entities that base financial determinations upon predictions of disease or to medical researchers who wish to target prevention and treatment to population groups. While the use of genetic information to make such determinations is unlawful in states and confidentiality and privacy concerns abound, methods for human “redlining” may occur. Thus, it is necessary to investigate the efficacy of the relationship of certain genetic information to ethnicity to determine if a statistical analysis can provide information concerning such relationship. The use of the statistical technique of discriminant analysis provides a tool for examining such relationship.

The effects of non-differential reinforcement and differential reinforcement on problem behaviors and accuracy of responding of autistic children was examined. In experiment 1, one child with autism participated, and in experiment 2, two children with autism participated. In the non-differential reinforcement condition both prompted and unprompted responses were reinforced. In the differential reinforcement condition only unprompted responses were reinforced. Overall, problem behaviors were more frequent in the non-differential reinforcement condition. In experiment 1, accuracy was higher in the differential reinforcement condition, while experiment 2 showed inconclusive results with regards to accuracy. It is concluded that non-differential reinforcement can decrease problem behaviors in teaching situations, but may not be sufficient to ensure acquisition of target tasks.

An anti-G"11 antibody was used to label neuronal cilia throughout the rat central nervous system. Immunoreactive cilia were observed in every examined region of the rat CNS, but not in monkey or mouse tissue. Antibodies to G"q and G"q/11 failed to label cilia. Immunoreactive cilia were observed as early as postnatal day 0 in spinal tissue, and postnatal day 3 in hypothalamic tissue. There was a statistically significant negative correlation between a region's mean cilium length and that region's distance to the nearest ventricle; regions nearest ventricles were those with the longest cilia. This correlation suggests neuronal cilia may function as chemosensors, detecting substances as they move out from the cerebrospinal fluid and into the extracellular space of the brain.

For a spectroscopy purpose, we are interested in producing continuous wave (CW) UV laser light at 243 nm with at least 2 mW power. The theory of nonlinear optics suggests that we should be able to produce a desired 2.9 mW of 243 nm light by second harmonic generation (SHG) from a 50 mW blue laser at 486 nm using a BBO crystal in a build up cavity. The most important physical parameters are calculated. A 10 mm Brewster cut BBO crystal can provide phase matching conditions for coupling two ordinary photons at 486 nm and make a secondary beam at 243 nm. The single pass conversion efficiency is calculated not to be enough to generate 2.9 mW of SH light. My investigation shows that a standing wave build up cavity can provide a buildup factor of 94 and an overall conversion efficiency of 5.9% if one use an input coupler mirror with 1.1% transmission at 486 nm.

The purpose of this study was to investigate supply chain relationships within the apparel retail product development process under a single site case study setting. Relationship determinants (i.e. drivers, facilitators and barriers) that facilitated or impeded the degree of collaborative efforts between the retailer and the supply chain members were identified. As the retailer integrated its product development process with its suppliers, a triangular relationship was formed between the retailer, the overseas manufacturers, and the designated suppliers. The study found that the retailer sought operational efficiency in its business relationships with supply chain members, but continued to seek long-term commitment in these relationships to establish a virtual vertical company.

The science-major General Chemistry sequence offered at the University of Houston has been investigated with respect to the effectiveness of recent incorporation of various levels of computer technology. As part of this investigation, questionnaire responses, student evaluations and grade averages and distributions from up to the last ten years have been analyzed and compared. Increased use of web-based material is both popular and effective, particularly with respect to providing extra information and supplemental questions. Instructor contact via e-mail is also well-received. Both uses of technology should be encouraged. In contrast, electronic classroom presentation is less popular. While initial use may lead to improved grades and retention, these levels decrease quickly, possibly due to a reduction in instructor spontaneity.

The purpose of this study is to assemble information needed to assess, understand and hopefully correct muscular hyperfunction that is related to tongue tension in singing and speech which inhibit freely, efficiently, and comfortably produced beautiful singing. This text will include a definition of freely produced, fully resonating tone for beautiful singing, major components of vocal technique, physiology related to singing and speech production, hyperfunctions associated with tongue tension, tongue involvement in the articulation of the four major singing languages, and will present exercises for training the muscles of coordination in a manner conducive to singing and speech.

Chapter I presents my background as an artist born and raised in Romania, and describes my artwork in connection with my interests and experiences. Maps and traditional Romanian art are important sources of influence. The questions in the statement of problem deal with the way ideas, references to various elements, and installation impact the artwork. Chapter II discusses the installation at the Dallas Visual Art Center, the creative process, and how the artwork addressed the questions in the statement of problem. Important points are: a step into three-dimensionality with the tall, freestanding pieces painted on both sides, the use of topographical contours in creating shapes, issues of form and content as expressed in the painted surfaces, and the interaction of the individual works in the installation.

This research is designed to test how sublethal exposure to copper affects tadpole predator-escape behavior and how quickly tadpoles recover. After exposure, tadpoles were separated. Escape behavior was recorded for two-thirds of exposed tadpoles while one-third of the exposed population was measured weekly to determine growth and recovery. Control tadpoles were consumed within 15 minutes whereas those exposed to higher concentrations were consumed at a slower rate, which does not support the hypotheses. Although the rate of predation was lower, tadpoles exposed to higher Cu concentrations were on average, 1.47 cm in total body length. Those exposed to 0.93 mg/L averaged 0.86 cm. After being placed into clean water, treatment tadpoles recovered after 20 days.

The City of Denton Landfill, Permit #1590A, utilizes “Dry-Tomb” techniques for disposal and promotion of municipal solid waste stabilization, as described by the Resource Conservation and Recovery Act (RCRA) prohibition in 40 CFR. Bioreactor research suggests re-circulating leachate increases biodegradation rates and reduces long-term monitoring from fifty years to less than ten years. Current procedures that are followed at Denton's landfill, literature review and the use of the Hydrologic Evaluation of Landfill Performance (HELP) model, suggest that a bioreactor landfill cell is worthy of further research. Re-circulating leachate and augmenting it with additional liquid will increase biodegradation and the need to design and build a landfill gas collection system to capture methane for energy recovery uses.