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 Collection: UNT Theses and Dissertations
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Functional and Categorical Analysis of Waveshapes Recorded on Microelectrode Arrays

Functional and Categorical Analysis of Waveshapes Recorded on Microelectrode Arrays

Date: May 2005
Creator: Schwartz, Jacob C.
Description: Dissociated neuronal cell cultures grown on substrate integrated microelectrode arrays (MEAs) generate spontaneous activity that can be recorded for up to several weeks. The signature wave shapes from extracellular recording of neuronal activity display a great variety of shapes with triphasic signals predominating. I characterized extracellular recordings from over 600 neuronal signals. I have preformed a categorical study by dividing wave shapes into two major classes: (type 1) signals in which the large positive peak follows the negative spike, and (type 2) signals in which the large positive peak precedes the negative spike. The former are hypothesized to be active signal propagation that can occur in the axon and possibly in soma or dendrites. The latter are hypothesized to be passive which is generally secluded to soma or dendrites. In order to verify these hypotheses, I pharmacologically targeted ion channels with tetrodotoxin (TTX), tetraethylammonium (TEA), 4-aminopyridine (4-AP), and monensin.
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"God will get me through": African American women coping with breast cancer and implications for support groups.

"God will get me through": African American women coping with breast cancer and implications for support groups.

Date: May 2005
Creator: McCoy, Brenda G.
Description: This research examines the coping processes of African American women with breast cancer and how those processes relate to low usage of cancer support groups by these women. Prior coping research has utilized predominantly White samples. The limited research on African American coping responses is conflicting and characterized by small samples and non-probability sampling techniques. In this study, 26 respondents from Central and North Texas metropolitan areas were interviewed, including 9 key informants, 9 African American breast cancer survivors, and 8 White survivors. The data suggest that African American and White women cope with breast cancer in significantly different ways. Culture appears to account for the differences. All African American breast cancer survivors identified faith as their primary coping strategy. In contrast, only half of the White survivors claimed faith as their primary coping strategy, but like the other White survivors, tended to rely on multiple coping strategies. The African American survivors conceptualized God as an active member of their support network. Most prayed for healing, and several attributed examples of healing to God's intervention. The White survivors found God's presence in the actions of other people. They prayed for strength, peace, and courage to endure the illness. The use ...
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N-Heterocyclic Carbenes of the Late Transition Metals: A Computational and Structural Database Study

N-Heterocyclic Carbenes of the Late Transition Metals: A Computational and Structural Database Study

Date: May 2005
Creator: Baba, Eduard
Description: A computational chemistry analysis combined with a crystallographic database study of the bonding in late transition metal N-heterocyclic carbene (NHC) complexes is reported. The results illustrate a metal-carbon bond for these complexes, approximately 4% shorter than that of a M-C single bond found in metal alkyl complexes. As a consequence of this result, two hypotheses are investigated. The first hypothesis explores the possibility of multiple-bond character in the metal-carbon linkage of the NHC complex, and the second, considers the change in the hybridization of the carbenoid carbon to incorporate more p character. The latter hypothesis is supported by the results. Analysis of these complexes using the natural bond orbital method evinces NHC ligands possessing trans influence.
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Higher Education and Entrepreneurship: The Relation between College Educational Background and Small Business Success in Texas

Higher Education and Entrepreneurship: The Relation between College Educational Background and Small Business Success in Texas

Date: May 2005
Creator: Al-Zubeidi, Mohammad
Description: This study examined the relationship between success of small businesses and the educational backgrounds of their owners. A survey composed of questions concerning demographics, educational backgrounds, and business success was mailed to 1100 businesses in Dallas, Denton, and Tarrant counties in Texas. There were 228 usable responses which were analyzed by using the Statistical Package of Social Sciences (SPSS12). Data were sorted so that educational level, sales volume, number of employees, and longevity, were identified on a 5-point ordinal scale. Educational major was identified on a 5-point nominal scale. Pearson's correlation was used to determine whether relationships existed between founders' educational background and small business success. Spearman's correlation was used to determine the direction and strength of the relationships. Then educational level and major were combined with age, gender, ethnicity, and industry, to determine the relationships between founders' educational background, and business success. For this purpose a canonical correlation was used. Five opinion questions concerned influence of college education on business success among college graduates and non-college graduates were identified on a 5-point Likert scale and tested using one-way ANOVA, and independent sample t-test. When educational level and major were the only predictors of business success, a statistically significant relationship ...
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Hungry Ghost

Hungry Ghost

Date: May 2005
Creator: Giarratano, Natalie A.
Description: Hungry Ghost is a collection of poetry that examines the relationships between fathers and daughters, sisters, and one's selves.
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The Impact of Predisposition Towards Group Work on Intention to Use a CSCW System

The Impact of Predisposition Towards Group Work on Intention to Use a CSCW System

Date: May 2005
Creator: Reyna, Josephine
Description: Groupware packages are increasingly being used to support content delivery, class discussion, student to student and student to faculty interactions and group work on projects. This research focused on groupware packages that are used to support students who are located in different places, but who are assigned group projects as part of their coursework requirements. In many cases, students are being asked to use unfamiliar technologies that are very different from those that support personal productivity. For example, computer-assisted cooperative work (CSCW) technology is different from other more traditional, stand-alone software applications because it requires the user to interact with the computer as well as other users. However, familiarity with the technology is not the only requirement for successful completion of a group assigned project. For a group to be successful, it must also have a desire to work together on the project. If this pre-requisite is not present within the group, then the technology will only create additional communication and coordination barriers. How much of an impact does each of these factors have on the acceptance of CSCW technology? The significance of this study is threefold. First, this research contributed to how a user's predisposition toward group work affects ...
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The implementation of international education in colleges and universities in the state of Texas: A follow-up study.

The implementation of international education in colleges and universities in the state of Texas: A follow-up study.

Date: May 2005
Creator: Hodges, Sarah
Description: This study is a follow-up to a study completed by Dr. Thomas Barker in 1994 entitled The Status of the Implementation of International Education in Texas Four-year Colleges and Universities: A Comprehensive Study. A survey of 35 Texas universities and 6 out-of-state benchmark universities revealed information regarding the international programs at these universities in four areas. The four areas surveyed include: (a) administrative, (b) instructional, (c) international student support services, and (d) outreach. A summary of the survey results includes 34 tables detailing the university responses for the 2004 survey compared with the responses obtained from the original, Barker (1994). The results from the 2004 participating benchmark institutions were also reviewed. Texas universities continue to work toward the internationalization of the curriculum with increased numbers supporting an international focus in their mission statements and staffing patterns. Benchmark institutions continue to lead Texas institutions in a majority of areas surveyed. Funding for international education continues to be an issue for both the benchmark and Texas institutions. Changes in attitudes and immigration policies continue to affect the implementation of international programs on the university level. While universities continue to provide support to community and businesses in the area of international education, the ...
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Institutions and Drug Markets

Institutions and Drug Markets

Date: May 2005
Creator: Haddock, Billy Dean
Description: This thesis examines how drug policy and enforcement affect drug manufacturers. The approach taken is a comparative institutional analysis of cannabis and methamphetamine production. I focus on the effects of prohibition, privacy, and clandestine markets on producer behavior for these two drugs and the unintended consequences that result. I demonstrate that cannabis and methamphetamine producers both face substantial transaction costs and that producers alter their behavior to manage these transaction costs. I conclude that cannabis producers can adopt indoor, small-scale operations to hide their activity, which are capable of yielding continuous, high-potency crops. Methamphetamine producers also adopt small-scale, decentralized strategies, but commodity control increases their exposure and leads to greater overall transaction costs during the manufacturing process.
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An integrative investigation of person-vocation fit, person-organization fit, and person-job fit perceptions.

An integrative investigation of person-vocation fit, person-organization fit, and person-job fit perceptions.

Date: May 2005
Creator: Kennedy, Michael
Description: Person-environment (PE) fit has been considered one of the most pervasive concepts in psychology. This study presents an integrative investigation of three levels of PE fit: person-vocation (PV) fit, person-organization (PO) fit, and person-job (PJ) fit, using multiple conceptualizations (e.g., value congruence, needs-supplies fit) of each fit level. While a trend in the PE fit literature has been the inclusion of only one fit level with a single conceptualization, researchers call for the addition of multiple conceptualizations of multiple fit levels in a single study. Traditionally, PO fit has been conceptualized as value congruence, whereas PV fit has remained untouched in the literature investigating the direct measurement of fit perceptions. Therefore, new fit perceptions scales assessing PO fit using a needs-supplies fit conceptualization and PV fit using a variety of conceptualizations were introduced. To address the limitation of employing direct measures, common method variance was modeled with a positive affect factor. The study accomplished two objectives. First, a previously supported three-factor model of fit perceptions consisting of PO value congruence (PO-VC), PJ needs-supplies (PJ-NS), and PJ demands-abilities (PJ-DA) fit was strongly replicated. Second, this model was expanded by examining additional conceptualizations (needs-supplies, demands-abilities fit, value, personality, and interest congruence) of ...
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Interfacial Study of Copper Electrodeposition with the Electrochemical Quartz Crystal Microbalance (EQCM)

Interfacial Study of Copper Electrodeposition with the Electrochemical Quartz Crystal Microbalance (EQCM)

Date: May 2005
Creator: Ojeda Mota, Oscar Ulises
Description: The electrochemical quartz crystal microbalance (EQCM) has been proven an effective mean of monitoring up to nano-scale mass changes related to electrode potential variations at its surface. The principles of operation are based on the converse piezoelectric response of quartz crystals to mass variations on the crystal surface. In this work, principles and operations of the EQCM and piezo-electrodes are discussed. A conductive oxide, ruthenium oxide (RuO2) is a promising material to be used as a diffusion barrier for metal interconnects. Characterization of copper underpotential deposition (UPD) on ruthenium and RuO2 electrodes by means of electrochemical methods and other spectroscopic methods is presented. Copper electrodeposition in platinum and ruthenium substrates is investigated at pH values higher than zero. In pH=5 solutions, the rise in local pH caused by the reduction of oxygen leads to the formation of a precipitate, characterized as posnjakite or basic copper sulfate by means of X-ray electron spectroscopy and X-ray diffraction. The mechanism of formation is studied by means of the EQCM, presenting this technique as a powerful in-situ sensing device.
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