7 resultados para Thompson, Francis J.: The reception of Byzantine culture in mediaeval Russia
em Digital Commons at Florida International University
Resumo:
Modern comprehensive high schools do not formally track students into different programs, but schools offer different curricular sequences with important and stratified consequences for students' post-secondary education. This study used qualitative methodology to examine how schools' organizational cultures influence the maintenance of tracking practices in four comprehensive high schools in Miami. The methodology included long-term participant observation in each of the four schools, unstructured and semi-structured interviews and the collection of written documents produced by the district. A framework based on the concepts of environment, mission, information, strategy, and leadership was used to analyze the data. ^ It was found that school cultures shared deeply held beliefs that regard ability as a fixed trait. This prevented schools from providing access to information about the consequences of course selection to the majority of the student body, with the exception of those students defined as “college bound.” State and County level policies that reward achievement in standardized tests combined with school overcrowding, resulted in organizational cultures that favored the adoption of strategies stressing efficiency, as opposed to a challenging education for all students. Only one of the four schools in the study had a policy requiring students to attempt courses that were more challenging. The practice was resented by both teachers and counselors, since it was perceived as interfering with other goals of the institution, i.e.: graduating students in four years. ^ The culture of the schools stressed college as the only legitimate post-secondary option; consequently, the majority of counselors did not encourage students—even those already defined as “not college material”—to consider other alternatives, such as vocational education. The elimination of formal tracks in these comprehensive high schools resulted in the school culture lacking a clear mission in regards to non-college bound students. Findings are discussed in relation to current theoretical explanations for educational policy and equality of opportunity. ^
Resumo:
Modern comprehensive high schools do not formally track students into different programs, but schools offer different curricular sequences with important and stratified consequences for students' post-secondary education. This study used qualitative methodology to examine how schools' organizational cultures influence the maintenance of tracking practices in four comprehensive high schools in Miami. The methodology included long-term participant observation in each of the four schools, unstructured and semi-structured interviews and the collection of written documents produced by the district. A framework based on the concepts of environment, mission,, information, strategy, and leadership was used to analyze the data. It was found that school cultures shared deeply held beliefs that regard ability as a fixed trait. This prevented schools from providing access to information about the consequences of course selection to the majority of the student body, with the exception of those students defined as "college bound." State and County level policies that reward achievement in standardized tests combined with school overcrowding, resulted in organizational cultures that favored the adoption of strategies stressing efficiency, as opposed to a challenging education for all students. Only one of the four schools in the study had a policy requiring students to attempt courses that were more challenging. The practice was resented by both teachers and counselors, since it was perceived as interfering with other goals of the institution, i.e.: graduating students in four years. The culture of the schools stressed college as the only legitimate post-secondary option; consequently, the majority of counselors did not encourage students-even those already defined as "not college material"-to consider other alternatives, such as vocational education. The elimination of formal tracks in these comprehensive high schools resulted in the school culture lacking a clear mission in regards to non-college bound students. Findings are discussed in relation to current theoretical explanations for educational policy and equality of opportunity.
Resumo:
The purpose of this research project was to contribute to the understanding of chloroplast movement in plants. Chloroplast movement in leaves from twenty tropical plant species ranging from cycads to monocots and varying in shade tolerance was examined by measuring changes in transmittance following 30 min. of exposure to white light at 1000 μmol m−2 s −1 in the wavelength range of 400–700 nm (photosynthetically active radiation, PAR). Leaf anatomical characteristics were also measured. Eighteen species increased significantly in transmittance (Δ T) at this level of illumination. ^ Chloroplast movement was significantly correlated with palisade cell width suggesting that cell dimensions are a significant constraint on chloroplast movement in the species examined. In addition, Δ T values were strongly correlated with values of an index of shade tolerance. ^ To further examine the relationship between palisade width and chloroplast movement, additional studies were conducted with a tropical aroid vine, Scindapsus aureus Schott. Scindapsus plants were grown under three different light treatments: 63% (control), 9.0% and 2.7% of full sunlight. Under these growing conditions plants produced markedly different palisade cell widths. Palisade cell width was again found to be correlated with transmittance changes. In addition, the observed increases in transmittance following exposure to the above illumination condition were correlated with absorbance of PAR. Fluorescence studies demonstrated that chloroplast movement helps protect Scindapsus aureus from the effects of photoinhibition when it is exposed to light at a higher intensity relative to the intensity of its normal environment. Ratios of variable fluorescence (Fv) to maximal fluorescence (Fm ) were higher in plants exposed to high light when chloroplasts moved than in plants where chloroplasts did not. ^ To further explore the role of chloroplast movement, studies were conducted to determine if transmittance changes could be induced in ten xerophytes at (1000 μmol m−2 s−1), as well as two stronger light intensities (1800 μmol m−2 s−1 and 2200 μmol m−2 s −1). Transmittance changes in the ten xerophytes were dependent upon the illumination intensity; nine out of the ten xerophytes changed in transmittance at 1800 μmol m−2 s−1. For the other two intensity levels, only three out of the ten xerophytes tested exhibited transmittance changes, and for two species, a negative Δ T value was obtained at 1000 μmol m−2 s−1 . No relationship was found between cell dimensions and chloroplast movement, although all species had large enough chlorenchyma cells to allow such movements. ^ The results of the study clearly show that in non-xerophytes, palisade cell anatomy is a strong constraint on chloroplast movement. This relationship may be the basis for the relationship between chloroplast movement and shade tolerance. Although absorbance changes are relatively small, chloroplast movement was clearly shown to reduce photoinhibition. ^
Resumo:
The emergence of tamoxifen or aromatase inhibitor resistance is a major problem in the treatment of breast cancer. The molecular signaling mechanism of antiestrogen resistance is not clear. Understanding the mechanisms by which resistance to these agents arise could have major clinical implications for preventing or circumventing it. Therefore, in this dissertation we have investigated the molecular mechanisms underlying antiestrogen resistance by studying the contributions of reactive oxygen species (ROS)-induced redox signaling pathways in antiestrogen resistant breast cancer cells. Our hypothesis is that the conversion of breast tumors to a tamoxifen-resistant phenotype is associated with a progressive shift towards a pro-oxidant environment of cells as a result of oxidative stress. The hypothesis of this dissertation was tested in an in vitro 2-D cell culture model employing state of the art biochemical and molecular techniques, including gene overexpression, immunoprecipitation, Western blotting, confocal imaging, ChIP, Real-Time RT-PCR, and anchorage-independent cell growth assays. We observed that tamoxifen (TAM) acts like both an oxidant and an antioxidant. Exposure of tamoxifen resistant LCC2 cell to TAM or 17 beta-estradiol (E2) induced the formation of reactive oxidant species (ROS). The formation of E2-induced ROS was inhibited by co-treatment with TAM, similar to cells pretreated with antioxidants. In LCC2 cells, treatments with either E2 or TAM were capable of inducing cell proliferation which was then inhibited by biological and chemical antioxidants. Exposure of LCC2 cells to tamoxifen resulted in a decrease in p27 expression. The LCC2 cells exposed to TAM showed an increase in p27 phosphorylation on T157 and T187. Conversely, antioxidant treatment showed an increase in p27 expression and a decrease in p27 phosphorylation on T157 and T187 in TAM exposed cells which were similar to the effects of Fulvestrant. In line with previous studies, we showed an increase in the binding of cyclin E-Cdk2 and in the level of p27 in TAM exposed cells that overexpressed biological antioxidants. Together these findings highly suggest that lowering the oxidant state of antiestrogen resistant LCC2 cells, increases LCC2 susceptibility to tamoxifen via the cyclin dependent kinase inhibitor p27.
Resumo:
Dr. Robert Moser, Associate Professor of Portuguese, Brazilian and Lusophone African Literature and Culture at the University of Georgia, lectures on the late Brazilian playwright Augusto Boal, who was known for developing the Theater of the Oppressed. Lecture held at Green Library, Modesto Maidique Campus, Florida International University.
Resumo:
Dr. Robert Moser, Associate Professor of Portuguese, Brazilian and Lusophone African Literature and Culture at the University of Georgia, lectures on the late Brazilian playwright Augusto Boal, who was known for developing the Theater of the Oppressed. Lecture held at Green Library, Modesto Maidique Campus, Florida International University.