A geochemical study of crustal plutonic rocks from the southern Mariana Trench forearc: Relationship to volcanic rocks erupted during subduction initiation

Two suites of intermediate-felsic plutonic rocks were recovered by dredges RD63 and RD64 (R/V KK81-06-26) from the northern wall of the Mariana trench near Guam, which is located in the southern part of the Izu-Bonin-Mariana (IBM) island arc system. The locations of the dredges are significant as the area contains volcanic rocks (forearc basalts and boninites) that have been pivotal in explaining processes that occur when one lithospheric plate initially begins to subduct beneath another. The plutonic rocks have been classified based on petrologic and geochemical analyses, which provides insight to their origin and evolution in context of the surrounding Mariana trench. Based on whole rock geochemistry, these rocks (SiO2: 49-78 wt%) have island arc trace element signatures (Ba, Sr, Rb enrichment, Nb-Ta negative anomalies, U/Th enrichment), consistent with the adjacent IBM volcanics. Depletion of rare earth elements (REEs) relative to primitive mantle and excess Zr and Hf compared to the middle REEs indicate that the source of the plutonic rocks is similar to boninites and transitional boninites. Early IBM volcanic rocks define isotopic fields (Sr, Pb, Nd and Hf-isotopes) that represent different aspects of the subduction process (e.g., sediment influence, mantle provenance). The southern Mariana plutonic rocks overlap these fields, but show a clear distinction between RD63 and RD64. Modeling of the REEs, Zr and Hf shows that the plutonic suites formed via melting of boninite crust or by crystallization from a boninite-like magma rather than other sources that are found in the IBM system. The data presented support the hypothesis that the plutonic rocks from RD63 and RD64 are products of subduction initiation and are likely pieces of middle crust in the forearc exposed at the surface by faulting and serpentine mudvolcanoes. Their existence shows that intermediate-felsic crust may form very early in the history of an intra-oceanic island arc system. Plutonic rocks with similar formation histories may exist in obducted suprasubduction zone ophiolites and would be evidence that felsic-intermediate forearc plutonics are eventually accreted to the continents.

Speciation, metabolism, toxicity, and protein-binding of different arsenic species in human cells

Despite of its known toxicity and potential to cause cancer, arsenic has been proven to be a very important tool for the treatment of various refractory neoplasms. One of the promising arsenic-containing chemotherapeutic agents in clinical trials is Darinaparsin (dimethylarsinous glutathione, DMA III(GS)). In order to understand its toxicity and therapeutic efficacy, the metabolism of Darinaparsin in human cancer cells was evaluated. With the aim of detecting all potential intermediates and final products of the biotransformation of Darinaparsin and other arsenicals, an analytical method employing high performance liquid chromatography inductively coupled mass spectrometry (HPLC-ICP-MS) was developed. This method was shown to be capable of separating and detecting fourteen human arsenic metabolites in one chromatographic run. The developed analytical technique was used to evaluate the metabolism of Darinaparsin in human cancer cells. The major metabolites of Darinaparsin were identified as dimethylarsinic acid (DMAV), DMA III(GS), and dimethylarsinothioyl glutathione (DMMTAV(GS)). Moreover, the method was employed to study the conditions and mechanisms of formation of thiol-containing arsenic metabolites from DMAIII(GS) and DMAV as the mechanisms of formation of these important As species were unknown. The arsenic sulfur compounds studied included but were not limited to the newly discovered human arsenic metabolite DMMTA V(GS) and the unusually highly toxic dimethylmonothioarsinic acid (DMMTAV). It was found that these species may form from hydrogen sulfide produced in enzymatic reactions or by utilizing the sulfur present in protein persulfides. Possible pathways of thiolated arsenical formation were proposed and supporting data for their existence provided. In addition to known mechanism of arsenic toxicity such as protein-binding and reactive oxygen formation, it was proposed that the utilization of thiols from protein persulfides during the formation of thiolated arsenicals may be an additional mechanism of toxicity. The toxicities of DMAV(GS), DMMTA V, and DMMTAV(GS) were evaluated in cancer cells, and the ability of these cells to take the compounds up were compared. When assessing the toxicity by exposing multiple myeloma cells to arsenicals externally, DMMTAV(GS) was much less toxic than DMAIII(GS) and DMMTAV, probably as a result of its very limited uptake (less than 10% and 16% of DMAIII(GS) and DMMTAV respectively).^

Assessing the effects of professionals' career decision -making on their participation reasons in continuing education in Taiwan

The purpose of this study was to assess the relationship between working professionals' Career Decision-Making Self-Efficacy beliefs (CDMSE beliefs) and their reasons for participating in in-service master's level programs in Taiwan. ^ The data collection instruments used were Grotelueschen's (1985) Participation Reasons Scale (PRS), and Betz, Klein, and Taylor's (1996) Career Decision-Making Self-Efficacy-Short Form (CDMSE-SF), and a Demographic Data Form (DDF) developed specifically for this study. ^ Surveys were administered to 800 working professionals who participated in inservice master's level programs at 22 Taiwanese universities. The survey was conducted in May 2004. Data were analyzed by simple descriptive statistics, principal component factor analysis, and multiple regression. Four factors of participation reasons were found and five components of CDMSE beliefs were scored. ^ Five components of CDMSE beliefs are structured into the CDMSE-SF instrument: Self-Appraisal, Occupational Information, Goal-Selection, Planning, and Problem Solving. The reasons for participation found in this study were: Professional Improvement and Development, Professional Service, Personal Benefit and Job Security, and Professional Competence and Collegial Interaction. Pearson-product moment correlations revealed significant positive correlations between the five CDMSE subscales and the four factors of participation reasons. Multiple regression analysis revealed that participants' beliefs in their abilities to obtain information about occupations accounted for the preponderance of variance of scores on the Participation Reasons Scale (PRS). ^ This study concluded that professionals who believed that they were efficacious in obtaining information about occupations or professions tended to believe that the four reasons for participation represented by the factors of the PRS were important to them in making the decision to participate in continuing education. Additionally, it was noted that the reasons for participations for professionals who did not feel confident in their abilities to find such information could not be determined. ^ Recommendations are offered to assist those individuals responsible for developing recruiting programs in continuing education for professionals in Taiwan. These recommendations focus only on strategies intended to attract this target population of professionals who believe that they are efficacious in obtaining information about occupations. ^

Rastafarianism and the Nation of Islam as institutions for group-identity formation among blacks in the United States: A case study comparing their approaches

This dissertation explores the Rastafari movement and the Nation of Islam as institutions that provide a group-identity for their adherents. The study seeks to determine the characteristics of the identity that is institutionalized by each movement, and the nature of the institutionalization process. The research was conducted primarily in South Florida where both movements exist. An extensive literature review in conjunction with in-depth field interviews were used as the primary research methodologies. What was of particular interest were the reasons that the members of the movements chose one movement over the other, also the similarities and dissimilarities between the movements in their role as institutions for group-identity formation. The research showed that both movements imbued their members with a sense of pride, high self-esteem and a strong sense of race consciousness. In addition, it showed that there was significant variation in identity orientation within the Rastafari Movement, which contrasted with the Nation of Islam where the identity variations within the movement were negligible. This was due largely to the difference in structure between the movements, the Nation of Islam being a centrally organized movement with one leader while the Rastafari movement is a decentralized polycephalous one. ^ Both movements were found to be millenarian in nature, essentially because of the significant utility of the concept that their members would rise to prominence through God's grace. Additionally, both movements were identified as expressive social movements, since they were determined as being primarily concerned with changing the attitudes of their members rather than effecting structural social change. ^

Clash of identities in South Florida: An examination of the complexity of racial and national identity and their impact on ethnic solidarity between black Americans and Jamaicans

Immigrants from the West Indies and other nations challenge the simple United States dichotomy of blacks versus whites. Many apparently black Caribbean immigrants proclaim that they did not know they were “black” until they arrived in the U.S. They seek to maintain their national identity and resist identity and solidarity with Black Americans. In response, many Black Americans respond that the immigrants are simply being naive, that U.S. society demands simple racial identity. Regardless of one's self-identity and personal history, in the U.S., if you look black, you are black, was their thinking. ^ This study examines the contemporary struggle of identity and solidarity among and between Black Americans and Jamaicans living in South Florida (Broward and Miami-Dade counties). Even though the primary focus of this study is to examine the relationship between Black Americans and Jamaicans, other West Indian nationals will be addressed more generally. The primary research problem of this study is to determine why the existence of common ancestry and physical traits are insufficient for an assumption of ethnic solidarity between Black Americans and Jamaicans. ^ In examining this problem, I felt that depth rather than breadth would provide insight into the current state of polarization between Black Americans and Jamaicans. To this end, a qualitative study was designed. A non-random snowball sample consisting of forty-seven informants was selected for this study. Realizing that such a technique presents problems with generalizations beyond the sample, this approach was, nonetheless, the most suitable for the current research problem. One of the initial challenges of this research was the use of the label “black” in discussing Caribbean immigrants. Unlike America, where distinctions based on skin color were at the bedrock of America's formation, this was not the case in the Caribbean. In the Caribbean skin color was an important marker as an indicator of class, rather than of race. Therefore, I refrained from using the label, “black Jamaicans,” but rather used Jamaicans throughout. ^

A study of stock market fluctuations and their relation to business conditions

Most research on stock prices is based on the present value model or the more general consumption-based model. When applied to real economic data, both of them are found unable to account for both the stock price level and its volatility. Three essays here attempt to both build a more realistic model, and to check whether there is still room for bubbles in explaining fluctuations in stock prices. In the second chapter, several innovations are simultaneously incorporated into the traditional present value model in order to produce more accurate model-based fundamental prices. These innovations comprise replacing with broad dividends the more narrow traditional dividends that are more commonly used, a nonlinear artificial neural network (ANN) forecasting procedure for these broad dividends instead of the more common linear forecasting models for narrow traditional dividends, and a stochastic discount rate in place of the constant discount rate. Empirical results show that the model described above predicts fundamental prices better, compared with alternative models using linear forecasting process, narrow dividends, or a constant discount factor. Nonetheless, actual prices are still largely detached from fundamental prices. The bubblelike deviations are found to coincide with business cycles. The third chapter examines possible cointegration of stock prices with fundamentals and non-fundamentals. The output gap is introduced to form the nonfundamental part of stock prices. I use a trivariate Vector Autoregression (TVAR) model and a single equation model to run cointegration tests between these three variables. Neither of the cointegration tests shows strong evidence of explosive behavior in the DJIA and S&P 500 data. Then, I applied a sup augmented Dickey-Fuller test to check for the existence of periodically collapsing bubbles in stock prices. Such bubbles are found in S&P data during the late 1990s. Employing econometric tests from the third chapter, I continue in the fourth chapter to examine whether bubbles exist in stock prices of conventional economic sectors on the New York Stock Exchange. The ‘old economy’ as a whole is not found to have bubbles. But, periodically collapsing bubbles are found in Material and Telecommunication Services sectors, and the Real Estate industry group.

Rastafarianism and the Nation of Islam as institutions for group-identity formation among blacks in the United States : a case study comparing their approaches

This dissertation explores the Rastafari movement and the Nation of Islam as institutions that provide a group-identity for their adherents. The study seeks to determine the characteristics of the identity that is institutionalized by each movement, and the nature of the institutionalization process. The research was conducted primarily in South Florida where both movements exist. An extensive literature review in conjunction with in-depth field interviews were used as the primary research methodologies. What was of particular interest were the reasons that the members of the movements chose one movement over the other, also the similarities and dissimilarities between the movements in their role as institutions for group-identity formation. The research showed that both movements imbued their members with a sense of pride, high self-esteem and a strong sense of race consciousness. In addition, it showed that there was significant variation in identity orientation within the Rastafari Movement, which contrasted with the Nation of Islam where the identity variations within the movement were negligible. This was due largely to the difference in structure between the movements, the Nation of Islam being a centrally organized movement with one leader while the Rastafari movement is a decentralized polycephalous one. Both movements were found to be millenarian in nature, essentially because of the significant utility of the concept that their members would rise to prominence through God's grace. Additionally, both movements were identified as expressive social movements, since they were determined as being primarily concerned with changing the attitudes of their members rather than effecting structural social change.

A Study of Stock Market Fluctuations and their Relations to Business Conditions

Most research on stock prices is based on the present value model or the more general consumption-based model. When applied to real economic data, both of them are found unable to account for both the stock price level and its volatility. Three essays here attempt to both build a more realistic model, and to check whether there is still room for bubbles in explaining fluctuations in stock prices. In the second chapter, several innovations are simultaneously incorporated into the traditional present value model in order to produce more accurate model-based fundamental prices. These innovations comprise replacing with broad dividends the more narrow traditional dividends that are more commonly used, a nonlinear artificial neural network (ANN) forecasting procedure for these broad dividends instead of the more common linear forecasting models for narrow traditional dividends, and a stochastic discount rate in place of the constant discount rate. Empirical results show that the model described above predicts fundamental prices better, compared with alternative models using linear forecasting process, narrow dividends, or a constant discount factor. Nonetheless, actual prices are still largely detached from fundamental prices. The bubble-like deviations are found to coincide with business cycles. The third chapter examines possible cointegration of stock prices with fundamentals and non-fundamentals. The output gap is introduced to form the non-fundamental part of stock prices. I use a trivariate Vector Autoregression (TVAR) model and a single equation model to run cointegration tests between these three variables. Neither of the cointegration tests shows strong evidence of explosive behavior in the DJIA and S&P 500 data. Then, I applied a sup augmented Dickey-Fuller test to check for the existence of periodically collapsing bubbles in stock prices. Such bubbles are found in S&P data during the late 1990s. Employing econometric tests from the third chapter, I continue in the fourth chapter to examine whether bubbles exist in stock prices of conventional economic sectors on the New York Stock Exchange. The ‘old economy’ as a whole is not found to have bubbles. But, periodically collapsing bubbles are found in Material and Telecommunication Services sectors, and the Real Estate industry group.