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Influence of Cholesterol Import on  Aspergillus fumigatus Growth and Antifungal Suscepibility

Influence of Cholesterol Import on Aspergillus fumigatus Growth and Antifungal Suscepibility

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Date: December 2003
Creator: Hassan, Saad A.
Description: Invasive pulmonary aspergillosis is a life-threatening fungal infection commonly observed in immunocompromised patients and has a mortality rate approaching 100% once the disease is disseminated. Aspergillus fumigatus is the most common pathogen. Early diagnosis improves the prognosis but is very difficult since most signs and symptoms are nonspecific. Antifungal therapy, usually based on sterol biosynthesis inhibitors, is also of limited efficacy. In my attempts to discover a diagnostic sterol marker for aspergillosis, I observed that A. fumigatus incorporates large amounts of cholesterol from serum-containing medium. This observation suggested the hypothesis that exogenous cholesterol from the host can be imported by A. fumigatus and used as a substitute for ergosterol in the cell membrane. This proposed mechanism would reduce the efficacy of antifungal drugs that act as sterol biosynthesis inhibitors. Experiments to test this hypothesis were designed to determine the effects of serum-free and serum-containing medium on growth of A. fumigatus in the presence and absence of azole antifungal agents. The results showed a marked increase in growth in the presence of human serum. Cultures in media containing cholesterol but no serum also showed enhanced growth, a result indicating that a non-cholesterol component of serum is not primarily responsible for the ...
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Integrating GIS with Benthic Metrics: Calibrating a Biotic Index to Effectively Discriminate Stream Impacts in Urban Areas of the Blackland Prairie Eco-Region

Integrating GIS with Benthic Metrics: Calibrating a Biotic Index to Effectively Discriminate Stream Impacts in Urban Areas of the Blackland Prairie Eco-Region

Date: December 2003
Creator: Earnest, Steven F. P.
Description: Rapid Bioassessment Protocols integrate a suite of community, population, and functional metrics, determined from the collection of benthic macroinvertebrates or fish, into a single assessment. This study was conducted in Dallas County Texas, an area located in the blackland prairie eco-region that is semi-arid and densely populated. The objectives of this research were to identify reference streams and propose a set of metrics that are best able to discriminate between differences in community structure due to natural variability from those caused by changes in water quality due to watershed impacts. Using geographic information systems, a total of nine watersheds, each representing a different mix of land uses, were chosen for evaluation. A total of 30 metrics commonly used in RBP protocols were calculated. Efficacy of these metrics to distinguish change was determined using several statistical techniques. Ten metrics were used to classify study area watersheds according to stream quality. Many trends, such as taxa presence along habitat quality gradients, were observed. These gradients coincided with expected responses of stream communities to landscape and habitat variables.
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Intelligent Memory Management Heuristics

Intelligent Memory Management Heuristics

Date: December 2003
Creator: Panthulu, Pradeep
Description: Automatic memory management is crucial in implementation of runtime systems even though it induces a significant computational overhead. In this thesis I explore the use of statistical properties of the directed graph describing the set of live data to decide between garbage collection and heap expansion in a memory management algorithm combining the dynamic array represented heaps with a mark and sweep garbage collector to enhance its performance. The sampling method predicting the density and the distribution of useful data is implemented as a partial marking algorithm. The algorithm randomly marks the nodes of the directed graph representing the live data at different depths with a variable probability factor p. Using the information gathered by the partial marking algorithm in the current step and the knowledge gathered in the previous iterations, the proposed empirical formula predicts with reasonable accuracy the density of live nodes on the heap, to decide between garbage collection and heap expansion. The resulting heuristics are tested empirically and shown to improve overall execution performance significantly in the context of the Jinni Prolog compiler's runtime system.
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Interfacial Electrochemistry and Surface Characterization: Hydrogen Terminated Silicon, Electrolessly Deposited Palladium & Platinum on Pyrolyzed Photoresist Films and Electrodeposited Copper on Iridium

Interfacial Electrochemistry and Surface Characterization: Hydrogen Terminated Silicon, Electrolessly Deposited Palladium & Platinum on Pyrolyzed Photoresist Films and Electrodeposited Copper on Iridium

Date: December 2003
Creator: Chan, Raymond
Description: Hydrogen terminated silicon surfaces play an important role in the integrated circuit (IC) industry. Ultra-pure water is extensively used for the cleaning and surface preparation of silicon surfaces. This work studies the effects of ultra-pure water on hydrogen passivated silicon surfaces in a short time frame of 120 minutes using fourier transform infrared spectroscopy – attenuated total reflection techniques. Varying conditions of ultra-pure water are used. This includes dissolved oxygen poor media after nitrogen bubbling and equilibration under nitrogen atmosphere, as well as metal contaminated solutions. Both microscopically rough and ideal monohydride terminated surfaces are examined. Hydrogen terminated silicon is also used as the sensing electrode for a potentiometric sensor for ultra-trace amounts of metal contaminants. Previous studies show the use of this potentiometric electrode sensor in hydrofluoric acid solution. This work is able to shows sensor function in ultra-pure water media without the need for further addition of hydrofluoric acid. This is considered a boon for the sensor due to the hazardous nature of hydrofluoric acid. Thin carbon films can be formed by spin coating photoresist onto silicon substrates and pyrolyzing at 1000 degrees C under reducing conditions. This work also shows that the electroless deposition of palladium and ...
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Investigation of the Pressure Dependence of SO3    Formation

Investigation of the Pressure Dependence of SO3 Formation

Date: December 2003
Creator: Naidoo, Jacinth
Description: The kinetics of the pressure dependent O + SO2 + Ar reaction have been investigated using laser photolysis resonance fluorescence at temperatures of 289 K, 399 K, 581 K, 699 K, 842 K and 1040 K and at pressures from 30-665 torr. Falloff was observed for the first time in the pressure dependence. Application of Lindemann theory yielded an Arrhenius expression of k(T) = 3.3 x 10-32exp(-992/T) cm6 molecule-1 s-1 for the low pressure limit and k(T) = 8.47 x 10-14exp(-468/T) cm3 molecule-1 s-1 for the high pressure limit at temperatures between 289 and 842 K. The reaction is unusual as it possesses a positive activation energy at low temperature, yet at higher temperatures the activation energy is negative, illustrating a reaction barrier.
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James Earl Rudder: A Lesson in Leadership

James Earl Rudder: A Lesson in Leadership

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Date: December 2003
Creator: Bean, Christopher B.
Description: This thesis is the about the life of Rudder. The emphasis of this work, however, is that Rudder was successful primarily because of his character and leadership style. Much of the study was drawn from primary sources. Secondary sources were also consulted. This thesis opens with a brief Introduction, which discusses the need for this work. Chapter 1 discusses Rudder's life prior to WW II, emphasizing particular characteristics that benefited his leadership ability. Chapter 2 examines the 2nd Ranger Battalion's transformation under Rudder's leadership and guidance. Chapter 3 chronicles the 2nd Ranger Battalion's assault on the Pointe du Hoc battery, ending in December 1944, when Col. Rudder was reassigned to the 109th Infantry Regiment. Moreover, the controversy surrounding the Ranger's mission is also examined in this chapter. Chapter 4 describes Col. Rudder's leadership with the 109th in the Battle of the Bulge. A chapter accounting Rudder's political career and leadership follows. Chapter 6 examines his term as chancellor and president of the Texas A&M University system, until his death in 1970, and the major institutional changes that he enacted during his tenure, which resulted in A&M becoming the respected research university it is today. This significance and recapitulation of Rudder's ...
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Job Embeddedness as a Predictor of Voluntary Turnover: Validation of a New Instrument

Job Embeddedness as a Predictor of Voluntary Turnover: Validation of a New Instrument

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Date: December 2003
Creator: Besich, John S.
Description: Voluntary turnover has become a problem for many organizations in today's society. The cost of this turnover reaches beyond organizational impact, but also affects the employees themselves. For this reason, there has been a plethora of research conducted by both academicians and practitioners on the causes and consequences of voluntary turnover. The purpose of this study is to test the validity and generalizability of the job embeddedness model of voluntary turnover to the information technology (IT) industry. The IT field has been plagued with high turnover rates in recent years. In this study, the job embeddedness model (Mitchell et al., 2001) is applied to a population sample consisting of health care information technology employees.
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Joy Harjo's Poetics of Transformation

Joy Harjo's Poetics of Transformation

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Date: December 2003
Creator: Rose-Vails, Shannon
Description: For Muscogee Creek poet Joy Harjo, poetry is a real world force that can empower the reader by utilizing mythic memory, recovery of history, and a spiral journey to regain communal identity. Her poetic career transforms from early lyric poems to a hybridized form of prosody, prose, and myth to accommodate and to reflect Harjo's concerns as they progress from personal, to tribal, and then to global. She often employs a witnessing strategy to combat the trauma caused by racism in order to create the possibility for renewal and healing. Furthermore, Harjo's poetry combats forces that seek to define Native American existence negatively. To date, Harjo's poetic works create a myth that will refocus humanity's attention on the way in which historical meaning is produced and the way difference is encountered. In an effort to revise the dominant stories told about Indians, Harjo privileges the idea that Native Americans are present and human, and it is this sense of humanity that pervades her poetry. Sequentially, Joy Harjo's volumes of poetry-She Had Some Horses (1983), In Mad Love and War (1990), and The Woman Who Fell from the Sky (1994)-create a regenerative cycle that combats the effects of oppressive history and ...
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Knowledge and attitudes of preservice teachers towards students who are gay, lesbian, bisexual, or transgendered.

Knowledge and attitudes of preservice teachers towards students who are gay, lesbian, bisexual, or transgendered.

Date: December 2003
Creator: Morgan, Daniel J.
Description: The study used a survey design to ascertain the levels of knowledge and attitudes of special education and non-special education preservice and inservice teachers towards students with different sexual orientations. The results of this study are based on 408 responses from preservice and inservice teachers enrolled at seven institutions of higher education within North Carolina, Virginia, and the District of Columbia offering teacher training programs in regular and/or special education. Two previously developed instruments were used to measure dependent variables in this study. Koch's modified version of The Knowledge about Homosexuality Questionnaire developep by Harris, Nightengale & Owen was used to measure the dependent variable of the preservice and inservice teacher's knowledge about homosexuality. Herek's Attitudes Toward Lesbians and Gay Men (ATLG) measured the dependent variable of attitudes towards homosexuals. The study found no significant differences reported mean scores for knowledge or attitude of homosexuality among the teacher groups surveyed: (a) special education preservice teachers, (b) non-special education preservice teachers, (c) special education inservice teachers, and (d) non-special education inservice teachers. Neither gender nor age were found to be factors in measures of knowledge or attitude of preservice or inservice teachers. Receiving prior instruction in serving the needs of GLBT ...
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Knowledge synthesis in the biomedical literature: Nordihydroguaiaretic acid and breast cancer.

Knowledge synthesis in the biomedical literature: Nordihydroguaiaretic acid and breast cancer.

Date: December 2003
Creator: Sneed, Wanda A.
Description: This dissertation refines knowledge synthesis from publicly accessible databases, based on the model of D.R. Swanson. Knowledge synthesis endeavors bring together two or more non-interactive literatures to create combinatorial research data on a specific topic. In this endeavor the biomedical literature was searched on the anti-neoplastic agent nordihydroguaiaretic acid (NDGA) for its potential role as a functional food in the chemoprevention of breast cancer. Bibliometric cocitation was utilized to identify complementary but non-interactive literatures in the disciplines of biomedicine and dietary science. The continuing specialization and fragmentation of the cancer literature degenerates the potential usefulness of cross-disciplinary research and information. As the biomedical sciences become more specialized the potential increases for isolation of discoveries and for failures to connect science to the needs of the people. Within the information science discipline several techniques are available to bridge the isolation between discoveries recorded in different sets of literatures. Electronic database searching with combinatorial keyword entries, syllogistic modeling and bibliometric author cocitation analysis are the principle techniques applied in this endeavor. The research questions are addressed to the absence or presence of human in vivo research on breast cancer with the potentially chemopreventative functional food NDGA. Utilizing a syllogistic model the literatures ...
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