The Effect of Dispersed Oil on the Calcification Rate of the Reef-Building Coral Diploria Strigosa

Hermatypic corals represent environmentally and economically important components of the reef ecosystem. Oil spills and clean-up operations in reef areas are potential sources of pollution impact. This paper presents an evaluation of the calcification rate of specimens of the reef-building coral Diploria strigosa in response to 24 hour treatments of chemically dispersed oil at concentrations of 20 ppm. The concentrations and durations were chosen to represent a scenario of a short-term oil spill treated with dispersant passing over a coral reef. Calcification rates were determined by the buoyant weight technique at several day intervals for up to 29 days following treatment. Results from laboratory experiments (Winter and Summer) conducted in a flow-through seawater system indicate that treated corals, both in comparison to untreated controls as well as to their pretreatment rates, experienced no depression in calcification. In contrast, a possible short-term enhancement of calcification for the treated corals was observed

Effects of a Dispersed and Undispersed Crude Oil on Mangroves, Seagrasses and Corals

The primary objective of this study was to evaluate the application of dispersant to spilled oil as a means of reducing adverse environmental effects of oil spills in nearshore, tropical waters. The results of numerous laboratory and field studies have suggested that dispersants may play a useful role in reducing adverse impacts on sensitive and valued environments such as mangroves, seagrasses, and corals. However, the use of dispersants has not been allowed thus far in most situations because of a lack of direct experimental data on the various effects of dispersants and the environmental trade-offs presumed to occur as a result of their application to crude oils. To accomplish this objective, a 21/2- year field experiment was designed in which detailed, synoptic measurements and assessments were made of representative intertidal and nearshore subtidal habitats and organisms (man-groves, seagrass beds, and coral reefs) before, during, and after exposure to untreated crude oil and chemically dispersed oil. The results were in-tended to give guidance in minimizing the ecological impacts of oil spills through evaluation of trade-offs in the relative impacts of chemical dispersion to tropical marine intertidal and subtidal habitats

La transformación del currículo en una sociedad diversa : ¿quién y cómo se decide el currículum?

The purpose of this article is to show how, in the United States, some states and school districts are transforming their curriculum through ethnic studies. Ethnic studies exists as a result of unequal power relations in which historically marginalized groups have not had the power to define how education will serve their own communities. According to its activists, ethnic studies not only teaches about the cultures of diverse groups, but also reconstructs, the curriculum around the counter-narratives perspectives, epistemologies, and visions of groups that have been treated historically as if their experiences and perspectives were of lesser value. The article begins with a theoretical framework that considers school knowledge as filtered through the perspectives of dominant groups. Sleeter then reviews research on the perspectives that structure the knowledge in school textbooks, showing how it represents narratives of dominant groups, and the impact of those perspectives on minoritized students. Then Sleeter considers ethnic studies as counter-narrative, and reviews research on the academic impact of ethnic studies on students. A limitation of the implementation of ethnic studies is that it addresses specific courses rather than transforming the whole curriculum. Sleeter developed a framework to help teachers transform their lessons and units in all disciplines, using the central ideas of ethnic studies; this framework is presented. The article concludes with a few implications for Spain from this work in the United State

Afterword -- culturally responsive teaching: A reflection

In the process of explaining multicultural education and culturally responsive teaching to preservice teachers, Grant and Sleeter (2007) commented that, “Fantastic teachers, as we observe them teach, are convinced that their students can learn, expect a lot of their students, and find ways to make whatever students bring to school a learning asset” (p. 133). The articles in this issue of Praxis thoughtfully elaborate on this idea, linking culturally responsive teaching with various areas of teacher education, and giving us insightful analyses and many rich examples for the classroom, professional preparation, and school reform

Employing culturally responsive pedagogy to foster literacy learning in schools

 In recent years it has become increasingly obvious that, to enable students in schools from an increasingly diverse range of cultural backgrounds to acquire literacy to a standard that will support them to achieve academically, it is important to adopt pedagogy that is responsive to, and respectful of, them as culturally situated. What largely has been omitted from the literature, however, is discussion of a relevant model of learning to underpin this approach. For this reason this paper adopts a socio-cultural lens (Vygotsky, 1978) through which to view such pedagogy and refers to a number of seminal texts to justify of its relevance. Use of this lens is seen as having a particular rationale. It forces a focus on the agency of the teacher as a mediator of learning who needs to acknowledge the learner’s cultural situatedness (Kozulin, 2003) if school literacy learning for all students is to be as successful as it might be. It also focuses attention on the predominant value systems and social practices that characterize the school settings in which students’ literacy learning is acquired. The paper discusses implications for policy and practice at whole-school, classroom and individual student levels of culturally-responsive pedagogy that is based on a socio-cultural model of learning. In doing so it draws on illustrations from the work of a number of researchers, including that of the author

Education policy as an act of white supremacy: whiteness, critical race theory and education reform

The paper presents an empirical analysis of education policy in England that is informed by recent developments in US critical theory. In particular, I draw on ‘whiteness studies’ and the application of Critical Race Theory (CRT). These perspectives offer a new and radical way of conceptualising the role of racism in education. Although the US literature has paid little or no regard to issues outside North America, I argue that a similar understanding of racism (as a multifaceted, deeply embedded, often taken-for-granted aspect of power relations) lies at the heart of recent attempts to understand institutional racism in the UK. Having set out the conceptual terrain in the first half of the paper, I then apply this approach to recent changes in the English education system to reveal the central role accorded the defence (and extension) of race inequity. Finally, the paper touches on the question of racism and intentionality: although race inequity may not be a planned and deliberate goal of education policy neither is it accidental. The patterning of racial advantage and inequity is structured in domination and its continuation represents a form of tacit intentionality on the part of white powerholders and policy makers. It is in this sense that education policy is an act of white supremacy. Following others in the CRT tradition, therefore, the paper’s analysis concludes that the most dangerous form of ‘white supremacy’ is not the obvious and extreme fascistic posturing of small neonazi groups, but rather the taken-for-granted routine privileging of white interests that goes unremarked in the political mainstream