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Fluorination Effect on the Conformational Properties of Alkanes

Description: A Series of fluorophores of the general formular P(CF2)nP and P(CF2)n-1CF3 has been synthesized. Copper catalyzed coupling of 1-bromopyrene and the corresponding mono and di-iodoperfluoroalkanes were used in most cases. For the n=3 dimer, a novel 1,w-perfluoroalkylation of pyrene via bis-decarboxylation of hexafluorogultaric acid was utilized. These compounds, along with suitable hydrocarbon analogs, are being used to study the flexibility of fluorocarbon chains using emission. We have found that the excimer formation for the fluorinated pyrene monomers is highly dependent on concentration and is less efficient than for pyene. Excimer formation for the fluorinated pyrene dimers is much more efficient than for the fluorocarbon monomers and is only slightly concentraion dependent. Steady-state emission spectra indicate hydrocarbon dimers-models form excimers more efficiently than the fluorinated dimers suggesting the fluorinated chains are stiffer than the hydrocarbons. We conducted the temperature-dependent studies and quantified the conformational difference.
Date: May 2002
Creator: Xu, Wenjian
Partner: UNT Libraries

Managerial self-awareness and its impact on leadership in high-performing managers.

Description: Managerial self-awareness is thought to impact leadership. A multi-rater feedback instrument was used to gather performance data on 70 managers in a large multi-national airline in regards to five leadership dimensions: making sound decisions, driving for results, effective communication, self-management, and innovation. Difference scores between self and direct reports were calculated and used as the operational definition of managerial self-awareness. T-tests were run to examine the difference between high performers and average performers. No significant differences were found. Additionally, correlational measures between the five leadership competencies and the managerial self-awareness measure indicated statistically weak relationships.
Date: May 2002
Creator: Yancey, Margaret
Partner: UNT Libraries

The Construct Validity of Self-Reported Historical Physical Activity

Description: The purpose of this study was to determine the construct validity of self-reported historical walking, running, and jogging (WRJ) activity. The criterion measure was concurrent performance on a maximal treadmill test. Subjects completed a medical exam and treadmill test between the years 1976 and 1985, and completed a follow-up questionnaire in 1986. Questionnaire included an item that assessed WRJ for each year from 1976 through 1985. Data analysis included Spearman correlations, partial correlations, ANOVA, and ANCOVA. Results indicated self-reported historical WRJ can be assessed with reasonable validity when compared with concurrently measured treadmill performance, and there is no decay in the accuracy of this reporting for up to ten years in the past.
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Date: May 2002
Creator: Bowles, Heather R.
Partner: UNT Libraries

Are the Needs of North Dakota's Aging Population with Developmental Disabilities Being Overlooked?

Description: North Dakota is faced with the challenge of meeting the needs of its growing population of elderly persons aging with a developmental disability. The challenge of creating new service models presents itself to professionals in the fields of Aging and Developmental Disabilities. Traditionally, the aging person with a developmental disability has been sent to nursing homes or grouped into community programs with younger persons with developmental disability. North Dakota is looking toward the future of caring for this special population through integration with elderly without disabilities.
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Date: May 2002
Creator: Clark, Amy Klein
Partner: UNT Libraries

The Effects of Non-differential Reinforcement and Differential Reinforcement on Problem Behaviors and Accuracy of Responding of Autistic Children.

Description: 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.
Date: May 2002
Creator: Ingvarsson, Einar Thor
Partner: UNT Libraries

Competency to Stand Trial: A Systematic Evaluation and Validation of the GCCT, MacCAT-CA, and ECST as Competency Measures

Description: 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.
Date: May 2002
Creator: Grandjean, Nicole Rae
Partner: UNT Libraries

The Effects of Selective Serotonin Reuptake Inhibitors (Ssri) on Auditory Measures in Clinically Depressed Subjects.

Description: 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.
Date: May 2002
Creator: Goodale, Elizabeth S.
Partner: UNT Libraries

A Survey of the Physical Education Programs for Girls in the Affiliated Schools within a Radius of Sixty Miles of Denton Texas

Description: A survey of the physical education programs for high school girls near Denton, Texas to determine the extent of compliance with state law for physical education, the facilities for the program, training of the teachers, type of physical education program, and teaching load of physical education teachers.
Date: June 1939
Creator: Morriss, May
Partner: UNT Libraries

Legal Status of Labor in Great Britain and the United States

Description: An investigation of the legal status of labor in Great Britain and the United States. The basis of labor legislation is considered, and the development of labor legislation traced in both countries. A comparison of the legal status of labor at the present time in both countries is made. - Abstract
Date: June 1939
Creator: Richardson, Addran Dee
Partner: UNT Libraries

Theoretical Study of Second Harmonic Generation of a Blue Laser at 486 nm Using a BBO Crystal in a Standing Wave Buildup Cavity

Description: 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.
Date: May 2002
Creator: Khademian, Ali
Partner: UNT Libraries

Supply chain relationships in apparel retail product development.

Description: 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.
Date: May 2002
Creator: Lee, Daton
Partner: UNT Libraries

The Extent of Cheating and Factors Related to Cheating in the Junior High School Grades

Description: Thesis studying instances of cheating in junior high school. According to the introduction, the purpose of the study is: 1. To determine the extent to which pupils in the junior high school grades will cheat when allowed to score their own examination papers. 2. To determine the relation between the professed attitude toward cheating on examinations and actual cheating behavior. 3. To determine some factors related to cheating (p. 1).
Date: August 1938
Creator: Watson, Lillian
Partner: UNT Libraries

To Determine Whether or Not the Colleges of Texas are Preparing their Students of Industrial Arts to Teach Effectively in the High Schools of Texas

Description: This is a study to determine whether the colleges of Texas are preparing their students of industrial arts to teach effectively in the high schools of Texas. The objectives of this study are to draw conclusions as to whether or not the colleges of Texas are preparing their students of industrial arts to teach effectively in the modern high schools; to show the training of industrial arts teachers; and to determine to what extent industrial arts are offered in the high schools of Texas.
Date: June 1939
Creator: Farmer, Joe Harold
Partner: UNT Libraries

An Analysis of the Effectiveness of Computer Assisted Instruction in General Chemistry at an Urban University.

Description: 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.
Date: May 2002
Creator: McGuffey, Angela
Partner: UNT Libraries

A Behavioral Economic Analysis of the Effects of Unit Price Sequence on Demand for Money in Humans.

Description: Three groups of participants were exposed to different unit price sequences. Unit prices for all groups ranged from unit price 1 to 21. Analyses of demand curves, response rates, session duration, and elasticity coefficients suggest that the sequence of exposure to unit prices can affect the elasticity of demand. In addition, the size of unit price contrast, direction of unit price change, and proximity to experimental milestones also may affect the consumption of monetary reinforcers.
Date: May 2002
Creator: Williams, Jack Keith
Partner: UNT Libraries

Effects of Sublethal Copper Exposure on Escape Behavior and Growth of Rana pipiens Tadpoles

Description: 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.
Date: May 2002
Creator: Redick, Melinda
Partner: UNT Libraries

A study of stock price reactions to the decisions of the Federal Open Market Committee (FOMC) on changes in the federal funds rate.

Description: 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.
Date: May 2002
Creator: Bushnell, Wesley
Partner: UNT Libraries

Ultrafast Laser Sampling of a Plant Tissue and ion Conductivity Measurement for Investigation of Light Stress Generation Mechanisms

Description: In this study we applied ultra-short laser pulses on a biological sample (Arabidopsis), in order to cut it precisely in a square pattern and subsequently use it for studying stress generation mechanisms. For this purpose, we utilized femtosecond laser pulses at 100 fs pulse width and 80 MHz repetition rate. We took two processing parameters into consideration such as laser power, laser exposure time which is related to the stage speed. Therefore, we were able to find the laser optimum conditions for ablation of biological tissues. The mutant and wildtype (control) obtained from laser cutting with a size of 500 µm × 500 µm were directly transferred (in-situ with laser cutting) into a microfabricated chamber containing ~500 nanoliters deionized water for measuring ion conductivity. The ion conductivity is a signature of cell-death mechanisms caused by various stresses. A light with intensity of 100 µmol was exposed to the samples for 2 hours and 20 minutes as a source of stress. A quantitative electrical analysis with high accuracy was assured by utilizing a microchamber, which enables a measurement in nanoliter volume. We measured the impedance which is reciprocal of conductivity using a lock-in amplifier and a precise current source at frequency of 130 Hz. Initially high impedance of mutant sample tended to drop within 2 hours and finally approached the constant value which signified that the cell death mechanism was complete. However, the wildtype sample demonstrated approximately constant impedance (conductivity) during the experiment.
Date: August 2010
Creator: Abtahi, Seyed Ali
Partner: UNT Libraries

Hepatotoxicity of Mercury to Fish

Description: Tissue samples from spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) were collected from Caddo Lake. Gar and bass livers were subjected to histological investigation and color analysis. Liver color (as abs at 400 nm) was significantly correlated with total mercury in the liver (r2 = 0.57, p = 0.02) and muscle (r2 = 0.58, p = 0.01) of gar. Evidence of liver damage as lipofuscin and discoloration was found in both species but only correlated with liver mercury concentration in spotted gar. Inorganic mercury was the predominant form in gar livers. In order to determine the role of mercury speciation in fish liver damage, a laboratory feeding study was employed. Zebrafish (Danio rerio) were fed either a control (0.12 ± 0.002 µg Hg.g-1 dry wt), inorganic mercury (5.03 ± 0.309 µg Hg.g-1 dry wt), or methylmercury (4.11 ± 0.146 µg Hg.g-1 dry wt) diet. After 78 days of feeding, total mercury was highest in the carcass of zebrafish fed methylmercury (12.49 ± 0.369 µg Hg.g-1 dry wt), intermediate in those fed inorganic mercury (1.09 ± 0.117 µg Hg.g-1 dry wt), and lowest in fish fed the control diet (0.48 ± 0.038 µg Hg.g-1 dry wt). Total mercury was highest in the viscera of methylmercury fed zebrafish (11.6 ± 1.86 µg Hg.g-1 dry wt), intermediate in those fed inorganic diets (4.3 ± 1.08 µg Hg.g-1 dry wt), and lowest in the control fish (below limit of detection). Total mercury was negatively associated with fish length and weight in methylmercury fed fish. Condition factor was not associated with total mercury and might not be the best measure of fitness for these fish. No liver pathologies were observed in zebrafish from any treatment.
Date: August 2010
Creator: Barst, Benjamin Daniel
Partner: UNT Libraries