15,257 research outputs found

    The Study of Nebular Emission on Nearby Spiral Galaxies in the IFU Era

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    A new generation of wide-field emission-line surveys based on integral field units (IFU) is allowing us to obtain spatially resolved information of the gas-phase emission in nearby late-type galaxies, based on large samples of HII regions and full two-dimensional coverage.These observations are allowing us to discover and characterise abundance differentials between galactic substructures and new scaling relations with global physical properties. Here I review some highlights of our current studies employing this technique: (1) the case study of NGC 628, the largest galaxy ever sampled with an IFU; (2) a statistical approach to the abundance gradients of spiral galaxies, which indicates a universal radial gradient for oxygen abundance; and (3) the discovery of a new scaling relation of HII regions in spiral galaxies, the local mass-metallicity relation of star-forming galaxies. The observational properties and constrains found in local galaxies using this new technique will allow us to interpret the gas-phase abundance of analogue high-z systems.Comment: Review article to appear in: "Metals in 3D: A Cosmic View from Integral Field Spectroscopy", Advances in Astronomy, Hindawi Publishing Corporatio

    [Review of] Guadalupe San Miguel, Jr. Let All of Them Take Heed : Mexican Americans and the Campaign for Educational Equality in Texas, 1910-1981

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    It is well known among educational researchers that pervasive segregation of blacks and underepresentation [underrepresentation] of Mexican Americans in higher education continues to this day, although these practices and policies violate federal law. A recent study by the Tomas Rivera Center for Policy Studies found that the state of Texas failed during the five years of its Equal Educational Opportunity Plan for Higher Education to eliminate the disparities in its system and improve the educational experiences of minorities. The structural dimensions of educational policy have a long and tumultuous history. Moreover, the notion that Mexican American parents care little for their children\u27s education lingers in the social attitudes of most Americans and in particular, policymakers. This factor exists today, in part, because social science has ignored the educational experiences of Mexican American students and the response to these experiences by the community

    [Review of] Douglas Monroy. Thrown Among Strangers: The Making of Mexican Culture in Frontier California

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    As one drives through the state of California, the legacy of Indian, Spanish, and Mexican cultures is obvious everywhere. In school, children learn how this land fell into the hands of the Spanish Crown with its mission system starting to bring Christianity to the Indians, how California became Mexican via the independence movement, and finally in the nineteenth century, how the United States came to control California. Yet little is known or understood about what the transfer of power meant or how it occurred

    [Review of] Leslie W. Dunbar, ed. Minority Report: What Has Happened to Blacks, Hispanics. American Indians, and Other Minorities in the Eighties

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    Six years since President Reagan took office, public policies related to the needs of the poor have been established which set back the gains of the Civil Rights movement. Although gains have been made, at least on the surface, the current administration\u27s policies have widened the gap between those who have and those who have not. Policies such as affirmative action, education programs, and public welfare are being eroded, sacrificed in favor of escalating military budgets and constructive engagement in Central America

    Online social lending: Borrower-generated content

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    This article explores online social lending, an innovative venture that represents a reintermediation in financial services. Borrowers and lenders now have access to online financial information services such as Motley Fool, http://www.fool.com/ , and the opportunity to communicate directly with each other online, sharing user-generated content, in the spirit of Web 2.0. In this environment, new possibilities emerge. Drawing on the literature of community banks, finance, and online banking, we conducted a structurational analysis of ZOPA(2007) a newly founded venture in online social lending whereby borrower/lender interactions take place within an open and transparent environment using discussion boards and blogs. ZOPA offers a service as an intermediary but one that differs from the intermediating role played by a traditional bank. We analyzed the possible attractions and risks of ZOPA’s service to customers, from the perspective of social lending and social networking, using public data from ZOPA’s website. Our intention is to understand the nature of this reintermediation and explain the development of this process through Giddens’ propositions

    The oxygen abundance in the IFU era

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    Spatially-resolved information of gas-phase emission provided by integral field units (IFUs) are allowing us to perform a new generation of emission-line surveys, based on large samples of HII regions and full two-dimensional coverage. Here we present two highlights of our current studies employing this technique: 1) A statistical approach to the abundance gradients of spiral galaxies, which indicates an -universal- radial gradient for oxygen abundance; and 2) The discovery of a new scaling relation of HII regions in spiral galaxies, the "local" mass-metallicity relation of star-forming galaxies.Comment: 6 pages, to appear in Highlights of Spanish Astrophysics VII, Proceedings of the X Scientific Meeting of the Spanish Astronomical Society held on July 9-13, 2012, in Valencia, Spai
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