18 resultados para Electronic states
em Digital Commons at Florida International University
Resumo:
The strong couplings between different degrees of freedom are believed to be responsible for novel and complex phenomena discovered in transition metal oxides (TMOs). The physical complexity is directly responsible for their tunability. Creating surfaces/interfaces add an additional ' man-made' twist, approaching the quantum phenomena of correlated materials. ^ The dissertation focused on the structural and electronic properties in proximity of surface of three prototype TMO compounds by using three complementary techniques: scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and low energy electron diffraction, particularly emphasized the effects of broken symmetry and imperfections like defects on the coupling between charge and lattice degrees of freedom. ^ Ca1.5Sr0.5RuO4 is a layered ruthenate with square lattice and at the boundary of magnetic/orbital instability in Ca2-xSrxRuO4. That the substitution of Sr 2+ with Ca2+ causing RuO6 rotation narrows the dxy band width and changes the Fermi surface topology. Particularly, the γ(dxy) Fermi surface sheet exhibited hole-like in Ca1.5Sr0.5RuO4 in contrast to electron-like in Sr2RuO4, showing a strong charge-lattice coupling. ^ Na0.75CoO2 is a layered cobaltite with triangular lattice exhibiting extraordinary thermoelectric properties. The well-ordered CoO2-terminated surface with random Na distribution was observed. However, lattice constants of the surface are smaller than that in bulk. The surface density of states (DOS) showed strong temperature dependence. Especially, an unusual shift of the minimum DOS occurs below 230 K, clearly indicating a local charging effect on the surface. ^ Cd2Re2O7 is the first known pyrochlore oxide superconductor (Tc ∼ 1K). It exhibited an unusual second-order phase transition occurring at TS1 = 200 K and a controversial first-order transition at TS2 = 120 K. While bulk properties display large anomalies at TS1 but rather subtle and sample-dependent changes at TS2, the surface DOS near the EF show no change at T s1 but a substantial increase below TS2---a complete reversal as the signature for the transitions. We argued that crystal imperfections, mainly defects, which were considerably enhanced at the surface, resulted in the transition at TS2. ^
Resumo:
The present study comparatively examined the socio-political and economic transformation of the indigenous Sámi in Sweden and the Indian American in the United States of America occurring first as a consequence of colonization and later as a product of interaction with the modern territorial and industrial state, from approximately 1500 to 1900. The first colonial encounters of the Europeans with these autochthonous populations ultimately created an imagery of the exotic Other and of the noble savage. Despite these disparaging representations, the cross-cultural settings in which these interactions took place also produced the hybrid communities and syncretic life that allowed levels of cultural accommodation, autonomous space, and indigenous agency to emerge. By the nineteenth century, however, the modern territorial and industrial state rearranges the dynamics and reaches of power across a redefined territorial sovereign space, consequently, remapping belongingness and identity. In this context, the status of indigenous peoples, as in the case of Sámi and of Indian Americans, began to change at par with industrialization and with modernity. At this point in time, indigenous populations became a hindrance to be dealt with the legal re-codification of Indigenousness into a vacuumed limbo of disenfranchisement. It is, thus, the modern territorial and industrial state that re-creates the exotic into an indigenous Other. The present research showed how the initial interaction between indigenous and Europeans changed with the emergence of the modern state, demonstrating that the nineteenth century, with its fundamental impulses of industrialism and modernity, not only excluded and marginalized indigenous populations because they were considered unfit to join modern society, it also re-conceptualized indigenous identity into a constructed authenticity.
Resumo:
This study examines changes in the Cuban family in the United States produced by time, migration, and the rise of new generations. The thesis will use a data set extracted from the 5% Public Use Microdata Series (PUMS) of the U.S. Decennial Census of Population for the years 1970, 1980 and 1990. Contingency table analysis and comparison of means were used to examine various family-related variables. The analysis points to changes in the traditional Cuban family towards less traditional family arrangements. The multigenerational feature of the Cuban household has diminished as the elderly have become independent and are more likely to be living on their own. Although female labor participation remains high, the occupational patterns of the first generation of Cuban women have diversified and a new trend has emerged for the second generation. The second generation of Cuban women demonstrates a strong inclination for white-collar occupations. Fertility rates remain low.
Resumo:
Many U.S. students do not perform well on mathematics assessments with respect to algebra topics such as linear functions, a building-block for other functions. Poor achievement of U.S. middle school students in this topic is a problem. U.S. eighth graders have had average mathematics scores on international comparison tests such as Third International Mathematics Science Study, later known as Trends in Mathematics and Science Study, (TIMSS)-1995, -99, -03, while Singapore students have had highest average scores. U.S. eighth grade average mathematics scores improved on TIMMS-2007 and held steady onTIMMS-2011. Results from national assessments, PISA 2009 and 2012 and National Assessment of Educational Progress of 2007, 2009, and 2013, showed a lack of proficiency in algebra. Results of curriculum studies involving nations in TIMSS suggest that elementary textbooks in high-scoring countries were different than elementary textbooks and middle grades texts were different with respect to general features in the U.S. The purpose of this study was to compare treatments of linear functions in Singapore and U.S. middle grades mathematics textbooks. Results revealed features currently in textbooks. Findings should be valuable to constituencies who wish to improve U.S. mathematics achievement. Portions of eight Singapore and nine U.S. middle school student texts pertaining to linear functions were compared with respect to 22 features in three categories: (a) background features, (b) general features of problems, and (c) specific characterizations of problem practices, problem-solving competency types, and transfer of representation. Features were coded using a codebook developed by the researcher. Tallies and percentages were reported. Welch's t-tests and chi-square tests were used, respectively, to determine whether texts differed significantly for the features and if codes were independent of country. U.S. and Singapore textbooks differed in page appearance and number of pages, problems, and images. Texts were similar in problem appearance. Differences in problems related to assessment of conceptual learning. U.S. texts contained more problems requiring (a) use of definitions, (b) single computation, (c) interpreting, and (d) multiple responses. These differences may stem from cultural differences seen in attitudes toward education. Future studies should focus on density of page, spiral approach, and multiple response problems.
Resumo:
This study explained the diversity of corporate financial practices in two nations. Existing studies have emphasized the reliance on equity finance in U.S. firms and bank loans in Japanese firms. In fact, patterns of corporate finance were much more complex. Financial institutions, which were created by national economic policy and regulation, affected corporate financial practices, but corporate financial practices often differed from what policymakers expected. Differences in corporate financial practices between nations also reflected differences in the mixture of industries in each nation. Many factors such as the amount of fixed capital, the process of production, the level of risk, the degree of innovation, and the importance of the industry in the national economy affected corporate financial practices. In addition, corporate financial practices within each nation differed from firm to firm due to managers’ considerations about stock ownership, which would affect their control power; corporate finance was closely related to control over management through ownership. To explain these complexities of corporate financial practices, the study linked corporate finance with the development of financial institutions in the United States and in Japan. While financial institutions affected corporate financial practices, the response of the firms to financial institutions and opportunities were diverse. The study also attempted to grasp variations in corporate financial practices by dealing with companies in three sectors: railroads, public utilities, and manufacturing. Finally, the study examined the structure of firm ownership. Contradictory to the widely held belief that U.S. firms distributed securities more widely to the public than did Japanese firms, many large American firms remained closely held, while some Japanese counterparts built publicly-held corporations.
Resumo:
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.
Resumo:
The purpose of this research was to study the nutritional status of United States Coast Guard Law Enforcement Detachment (USCG/ LEDET) personnel before and after prolonged travel at sea. To date there is no information available regarding the nutritional status of Coast Guard personnel. Forty-seven subjects were studied in total, each served as their own control. Demographic and health history data was collected at baseline. Dietary and exercise data was collected before and during the deployment. Body composition was determined before and after a deployment. The results of this study revealed that the USCG/LEDET personnel had high cholesterol and decreased fiber intakes. Cholesterol intake during deployment (516.8±239.7 mg/day) was significantly higher (p= 0. 047) than pre-deployment (448.2 ± 144.3 mg/day). Fiber intake was significantly lower than recommended (p The results of this study indicate that LEDET personnel are put at higher nutritional risk while deployed and also have increased negative health behaviors associated with risk for Cardiovascular Disease (CVD) and other related diseases. This is crucial information for the USCG so that action can be taken to improve the physical well being of their personnel.
Resumo:
The Soviet Union's dissolution in December 1991 marks the end of the Cold War and the elimination of the United States' main rival for global political-economic leadership. For decades U.S. foreign policymakers had formulated policies aimed at containing the spread of Soviet communism and Moscow's interventionist policies in the Americas. They now assumed that Latin American leftist revolutionary upheavals could also be committed to history. This study explores how Congress takes an active role in U.S. foreign policymaking when dealing with revolutionary changes in Latin America. This study finds that despite Chavez's vitriolic statements and U.S. economic vulnerability due to its dependence on foreign oil sources, Congress today sees Chavez as a nuisance and not a threat to U.S. vital interests. Devoid of an extra-hemispheric, anti-American patron intent on challenging the United States for regional leadership, Chavez is seen by Congress largely as a threat to the stability of Venezuela's institutions and political-economic stability. Today both the U.S. executive and the legislative branches largely see Bolivarianism a distraction and not an existential threat. The research is based on an examination of Bolivarian Venezuela compared to revolutionary upheaval and governance in Nicaragua over the course of the twentieth century. This project is largely descriptive, qualitative in approach, but quantitative data are used when appropriate. To analyze both the U.S. executive and legislative branches' reaction to revolutionary change, Cole Blasier's theoretical propositions as developed in the Hovering Giant: U.S. Responses to Revolutionary Change in Latin America 1910- 1985 are utilized. The present study highlights the fact that Blasier's propositions remain a relevant means for analyzing U.S. foreign policymaking.
Resumo:
Introduction: The United States today has become "meeting-conscious." The complexity of conducting business has led to the need for sophisticated coordination of decision-making processes on all levels of the organization. Company meetings have played an increasingly important role in the success and future of many companies. Strategies and decisions are developed at meetings that can determine future policies of crucial importance. Executive training can mean the difference in whether the company will even survive. Large and growing companies have increased their off-premise meeting budgets annually in spite of the state of the economy. however, the rising costs of travel and lodging have made management monitor these budgets more closely than ever. Thus, the need to use every dollar efficiently has compelled companies to examine newer methods of running meetings and alternatives to the usage of typical off-premise meeting facilities. The importance of off-premise meetings in the United States economy has greatly increased due to the billions of dollars spent annually. These factors make it vital to explore the effectiveness of time and monetary expenditures. Up until the mid-1960's, company meetings were held in facilities of various design and purpose, none of which were specifically designed for the small to medium corporate meeting. Upon gathering information concerning the meetings market and the corporate meeting planner, certain individuals endeavored to change the situation. This study is designed to investigate this new concept, which will hereafter be referred to as "conference center." For the purpose of this study, the following two definitions will be used. 1. Conference center - that meeting facility primarily marketing its facilities for the small to medium-sized corporate meeting. The center is operated by specialists aware of market needs in as much detail as are those people working for the company involved. On-premise sleeping rooms are not mandatory provided such facilities are within easy access. 2. Meeting planner - that person within an organization who has primary responsibility for arranging off-premise meetings and all other related items necessary for meeting effectiveness. This person may spend anywhere from 10 to 100l of his time in this capacity. The conference center has effectively satisfied the need for specialized corporate meeting facilities. This study will show the depth of the corporate meetings market and trace the growth and development of this relatively new conference center concept. Information will also be compiled on the top centers in the country. It is hoped that by presenting this research meeting planners will become more aware of the nature and location of these centers, especially for use by the small to medium-sized company. Such exposure of the centers will hopefully increase existing demand and enable the construction of new, innovative centers.
Resumo:
This study examined immigrant minority students' perceptions of race relations and of the chances for social mobility in the United States (U.S.) using cohort samples of West Indian (N=173) and Haitian (N=191) students. The Students' responses collected during the 6th and 7th, 8th and 9th grades were analyzed to determine whether perceptions of racial mistrust, teacher derogation and social mobility varied depending on the student's length of stay in the U.S. or self-concept. Quantitative methodology was applied to data extrapolated from a larger epidemiological longitudinal study consisting of 7, 386 middle school students in Miami (Vega and Gil, 1998). Results show that West Indian and Haitian students' perceptions of racial mistrust, teacher derogation and social mobility were associated more with student's self-concept than length of stay. Students with more favorable self-concepts reported greater optimism toward social mobility than those with less favorable self-concepts. Results also indicate that in the context of parental education and SES that racial mistrust is the strongest predictor of these students' level of optimism towards social mobility.
Resumo:
Seven Jewish Holocaust survivors were interviewed using a phenomenological method to determine the essence of the Jewish Holocaust survivor's experience with health care in the United States today. The transcriptions were analyzed using Colaizzi's approach to phenomenological research. This approach includes extraction of significant statements, from the transcriptions, that described the participant's health care behaviors and needs. Formulated meanings of the significant statements were then organized into six themes: Hiding and Avoidance, Self care, Fear/Trust Dichotomy, Security, Luck, and Need for Understanding. These six themes were forms of protection for the participants, which ultimately led to continued survival, the essence of their experience. Knowledge of their experience may direct the nurse in implementing creative and appropriate nursing interventions to provide comfort and assist the survivor with their needs in today's health care arena.
Resumo:
Developed countries give foreign assistance for many reasons, one of which is the protection of national interests. Foreign aid gives a donor country leverage in international relations and is used as a tool of foreign policy. The United States and Japan are the two largest aid donors in the world. Each of these countries exert influence over specific regions through foreign assistance. Although the national interests of each country are different, both use foreign aid to protect these interests. This thesis discusses the means by which the United States and Japan use foreign aid in foreign policy. It looks specifically at U.S. food aid to Central America and Japanese aid to Asia.
Resumo:
This thesis examines the involvement of the United States in the decade-long trade dispute before the World Trade Organization (WTO) over the European Union's preferential banana regime. Washington's justification for bringing this case to the WTO comes from Section 301 of the U.S. trade act, which allows for disputes to be undertaken if U.S. "interests" are violated; however, this is the first case ever undertaken by the United States that does not directly threaten any American banana industry, nor affect any American jobs. Why, then, would the United States involve itself in this European-Caribbean-Latin American dispute? It is the contention of this thesis that the United States thrust itself headlong into this debate for two reasons: domestically, the United States Trade Representative came under pressure, via the White House and Congress, from Chiquita CEO Carl Lindner, who in the past decade donated more than $7.1 million to American politicians to take the case to the WTO. Internationally, the United States used the case as an opportunity to assert its power over Europe, with the Eastern Caribbean islands being caught in the economic crossfire. According to existing literature, in undertaking this case, the United States did as any nation would: it operated within both domestic and international levels, satisfying at each level key interests, with the overall goal of maintaining the nation's best interests.
Resumo:
Interest in the health of marine mammals has increased due, in part, to the attention given to human impact on the marine environment. Recent mass strandings of the Atlantic bottlenose dolphin (Tursiops truncatus) and rising mortalities of the endangered Florida manatee (Trichechus manatus latirostris) have raised questions on the extent to which pollution, infectious disease, "stress," and captivity influence the immune system of these animals. This study has provided the first in-depth characterization of immunocytes in the peripheral blood of dolphins (n=180) and manatees (n=56). Immunocyte morphology and baseline values were determined in clinically normal animals under free-ranging, stranded and captive living conditions as well as by age and sex. Additionally, immuocyte population dynamics were characterized in sick animals. This was accomplished with traditional cytochemical techniques and new lymphocyte phenotyping methodology which was validated in this study. Traditional cytochemical techniques demonstrated that blood immunocyte morphology and cell numbers are similar to terrestrial mammals with some notable exceptions. The manatee heterophilic granulocyte is a morphologically unique cell and probably functions similarly to the typical mammalian neutrophil. Eosinophils were rarely found in manatees but were uncommonly high in healthy and sick dolphins. Basophils were not identified. Manatees had higher total lymphocyte numbers compared to dolphins and most terrestrial mammals. Lymphocyte subsets identified in healthy animals included Th, Tes, B and NK cells. Dolphin and manatee T and B cell values were higher than those reported in man and most terrestrial mammals. The manatee has extraordinarily high absolute numbers of circulating Th cells which suggests an enhanced immunological response capability. With few exceptions, immunocyte types and absolute numbers were not significantly different between free-ranging, stranded and captive categories or between sex and age categories. The evaluation of immunocyte dynamics in various disease states demonstrated a wide variation in cellular responses which provided new insights into innate, humoral and cell-mediated immunity in these species. Additionally, this study demonstrated that lymphocyte phenotyping has diagnostic significance and could be developed into a potential indicator of immunocompetence in both free-ranging and captive dolphin and manatee populations.
Resumo:
In the wake of a steadily increasing diversity in ethnicity among Blacks in the United States, efforts need to be made to analyze and understand the dynamics of the relations among the various Black ethnic groups in the United States. This thesis explores the present state of relations among these groups by utilizing an extensive literature review on the topic in conjunction with in-depth interviews. What is of particular interest here are the differing and similar intergroup perspectives on self-identity, as well as any cultural similarities and dissimilarities that exist. We find that the cultural dissimilarities create barriers to harmonious relations among the groups, while particular ideologies such as Pan-Africanism and Black nationalism provide the basis for strong unified fronts and partnerships for those who embrace them.