214 research outputs found

    The freemasonry of the race : The cultural politics of ritual, race, and place in postemancipation Virginia

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    African American cultural and social history has neglected to interrogate fully a crucial facet of African American political, economic, and social life: African American Freemasonry. The Freemasonry of the Race : The Cultural Politics of Ritual, Race, and Place in Postemancipation Virginia seeks to remedy this neglect. This project broadly situates African American Freemasonry in the complex and evolving relations of power, peoples, and polities of the Atlantic world. The study develops an interpretative framework that not only recognizes the organizational and institutional aspects of African American Freemasonry, but also interprets it as a discursive space in and through which articulations of race, class, gender, and place are theorized and performed.; The Freemasonry of the Race presents a critical cartography of African American Freemasons\u27 responses to the social and political exigencies of the postemancipation period. The study connects the developments of African American Freemasonry in the Atlantic world with the every day culture of African American Freemasonry in Charlottesville, Virginia from the conclusion of the Civil War until the turn of the century. Utilizing African American Freemasonry as a critical optic, the major question this study attempts to respond to is: How can we historicize and (re)present African American Freemasonry in order to rethink the cultural and political space of the postemancipation period in the United States?;Borrowing and blending a number of methodologies from social history, literary theory, and cultural studies, The Freemasonry of the Race : The Cultural Politics of Ritual, Race, and Place in Postemancipation Virginia presents a set of analytic essays on African American Freemasonry, each intimately concerned with deciphering some of the principles that organized and (re)constructed various regimes of power and normality along the fault lines of race, sex, gender, class, and place. By thinking and working through African American Freemasonry in such a manner, this project seeks to open up new interdisciplinary horizons in African American cultural and social history

    [Introduction to] Community Wealth Building and the Reconstruction of American Democracy: Can We Make American Democracy Work?

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    How can we create and sustain an America that never was, but should be? How can we build a truly multiracial democracy in which everyone is valued and possesses the needed political, economic and social capital so that democracy becomes a meaningful way of life, for all citizens? By critically probing these questions, the editors of Community Wealth Building and the Reconstruction of American Democracy seize the opportunity to bridge the gap between our democratic aspirations and our current reality. In a moment of democratic disappointment and anxiety, politicians, policy officials, scholars and citizens desire an effective response. This book assembles new voices and novel perspectives that offer a compelling vision for democracy and the prospects and possibilities afforded by community wealth building, an emerging policy paradigm focused on community-based, creative solutions to systemic problems. The contributors explore how, by cultivating the capacities of citizens, American democracy can be revived - indeed, created - as a veritable practice of everyday life. Scholars of democracy in political science, history, sociology, public policy, economics, African-American studies and related topics as well as policy practitioners, journalists and students will appreciate the cutting-edge work by leading scholars and the contributions from impactful practitioners from the White House to City Halls, in this discussion of the challenges facing contemporary American democracy and the prospects for reform and change. Please download the Introduction from the link above. You may purchase this book directly from the publisher from the link below.https://scholarship.richmond.edu/bookshelf/1381/thumbnail.jp

    WSClean : an implementation of a fast, generic wide-field imager for radio astronomy

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.Astronomical widefield imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays. We present a new widefield interferometric imager that uses the w-stacking algorithm and can make use of the w-snapshot algorithm. The performance dependencies of CASA's w-projection and our new imager are analysed and analytical functions are derived that describe the required computing cost for both imagers. On data from the Murchison Widefield Array, we find our new method to be an order of magnitude faster than w-projection, as well as being capable of full-sky imaging at full resolution and with correct polarisation correction. We predict the computing costs for several other arrays and estimate that our imager is a factor of 2-12 faster, depending on the array configuration. We estimate the computing cost for imaging the low-frequency Square-Kilometre Array observations to be 60 PetaFLOPS with current techniques. We find that combining w-stacking with the w-snapshot algorithm does not significantly improve computing requirements over pure w-stacking. The source code of our new imager is publicly released.Peer reviewedFinal Published versio

    High-energy sources at low radio frequency : the Murchison Widefield Array view of Fermi blazars

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    This is the accepted version of the following article: Giroletti, M. et al., A&A, 588 (2016) A141, which has been published in final form at DOI: http://dx.doi.org/10.1051/0004-6361/201527817. This article may be used for non-commercial purposes in accordance with the EDP Sciences self-archiving policies.Low-frequency radio arrays are opening a new window for the study of the sky, both to study new phenomena and to better characterize known source classes. Being flat-spectrum sources, blazars are so far poorly studied at low radio frequencies. We characterize the spectral properties of the blazar population at low radio frequency compare the radio and high-energy properties of the gamma-ray blazar population, and search for radio counterparts of unidentified gamma-ray sources. We cross-correlated the 6,100 deg^2 Murchison Widefield Array Commissioning Survey catalogue with the Roma blazar catalogue, the third catalogue of active galactic nuclei detected by Fermi-LAT, and the unidentified members of the entire third catalogue of gamma-ray sources detected by \fermilat. When available, we also added high-frequency radio data from the Australia Telescope 20 GHz catalogue. We find low-frequency counterparts for 186 out of 517 (36%) blazars, 79 out of 174 (45%) gamma-ray blazars, and 8 out of 73 (11%) gamma-ray blazar candidates. The mean low-frequency (120--180 MHz) blazar spectral index is αlow=0.57±0.02\langle \alpha_\mathrm{low} \rangle=0.57\pm0.02: blazar spectra are flatter than the rest of the population of low-frequency sources, but are steeper than at \simGHz frequencies. Low-frequency radio flux density and gamma-ray energy flux display a mildly significant and broadly scattered correlation. Ten unidentified gamma-ray sources have a (probably fortuitous) positional match with low radio frequency sources. Low-frequency radio astronomy provides important information about sources with a flat radio spectrum and high energy. However, the relatively low sensitivity of the present surveys still misses a significant fraction of these objects. Upcoming deeper surveys, such as the GaLactic and Extragalactic All-Sky MWA (GLEAM) survey, will provide further insight into this population.Peer reviewedFinal Published versio

    Psychologists’ Authenticity: Implications for Work in Professional and Therapeutic Settings

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    Derek J. Burks, PhD, is a licensed psychologist and postdoctoral psychology fellow at the Pacific Northwest Mental Illness Research, Education, and Clinical Center (MIRECC), located within the Veterans Affairs Medical Center in Portland, Oregon. He obtained his PhD in counseling psychology from the University of Oklahoma. His current research focuses on health disparities, posttraumatic stress disorder among sexual-minority U.S. military veterans, and culturally appropriate mental health treatment for American Indians.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    The Murchison Widefield Array Commissioning Survey : A Low-Frequency Catalogue of 14,110 Compact Radio Sources over 6,100 Square Degrees

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    22 pages, 18 figures, accepted to PASAWe present the results of an approximately 6,100 square degree 104--196MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the Murchison Widefield Array Commissioning Survey (MWACS). The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 hPeer reviewedFinal Accepted Versio

    The First Murchison Widefield Array low-frequency radio observations of cluster scale non-thermal emission: the case of Abell 3667

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    We present the first Murchison Widefield Array observations of the well-known cluster of galaxies Abell 3667 (A3667) between 105 and 241 MHz. A3667 is one of the best known examples of a galaxy cluster hosting a double radio relic and has been reported to contain a faint radio halo and bridge. The origin of radio haloes, relics and bridges is still unclear, however galaxy cluster merger seems to be an important factor. We clearly detect the north-west (NW) and south-east radio relics in A3667 and find an integrated flux density at 149 MHz of 28.1 ± 1.7 and 2.4 ± 0.1 Jy, respectively, with an average spectral index, between 120 and 1400 MHz, of −0.9 ± 0.1 for both relics. We find evidence of a spatial variation in the spectral index across the NW relic steepening towards the centre of the cluster, which indicates an ageing electron population. These properties are consistent with higher frequency observations. We detect emission that could be associated with a radio halo and bridge. However, due to the presence of poorly sampled large-scale Galactic emission and blended point sources we are unable to verify the exact nature of these features

    On the detection and tracking of space debris using the Murchison Widefield Array. I. Simulations and test observations demonstrate feasibility

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    The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope, operating in the benign radio frequency environment of remote Western Australia. The MWA is the low-frequency precursor to the Square Kilometre Array (SKA) and is the first of three SKA precursors to be operational, supporting a varied science mission ranging from the attempted detection of the Epoch of Reionization to the monitoring of solar flares and space weather. In this paper we explore the possibility that the MWA can be used for the purposes of Space Situational Awareness (SSA). In particular we propose that the MWA can be used as an element of a passive radar facility operating in the frequency range 87.5-108 MHz (the commercial FM broadcast band). In this scenario the MWA can be considered the receiving element in a bi-static radar configuration, with FM broadcast stations serving as non-cooperative transmitters. The FM broadcasts propagate into space, are reflected off debris in Earth orbit and are received at the MWA. The imaging capabilities of the MWA can be used to simultaneously detect multiple pieces of space debris, image their positions on the sky as a function of time and provide tracking data that can be used to determine orbital parameters. Such a capability would be a valuable addition to Australian and global SSA assets, in terms of southern and eastern hemispheric coverage. We provide a feasibility assessment of this proposal, based on simple calculations and electromagnetic simulations, that shows that the detection of sub-meter size debris should be possible (debris radius of >0.5 m to ∼1000 km altitude). We also present a proof-of-concept set of observations that demonstrate the feasibility of the proposal, based on the detection and tracking of the International Space Station via reflected FM broadcast signals originating in southwest Western Australia. These observations broadly validate our calculations and simulations. We discuss some significant challenges that need to be addressed in order to turn the feasible concept into a robust operational capability for SSA. The aggregate received power due to reflections off space debris in the FM band is equivalent to a <1 mJy increase in the background confusion noise for the long integrations needed for Epoch of Reionization experiments, which is insignificant

    The first Murchison Widefield Array low frequency radio observations of cluster scale non-thermal emission : the case of Abell 3667

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.We present the first Murchison Widefield Array observations of the well-known cluster of galaxies Abell 3667 (A3667) between 105 and 241 MHz. A3667 is one of the best known examples of a galaxy cluster hosting a double radio relic and has been reported to contain a faint radio halo and bridge. The origins of radio halos, relics and bridges is still unclear, however galaxy cluster mergers seems to be an important factor. We clearly detect the North-West (NW) and South-East (SE) radio relics in A3667 and find an integrated flux density at 149 MHz of 28.1 +/- 1.7 and 2.4 +/- 0.1 Jy, respectively, with an average spectral index, between 120 and 1400 MHz, of -0.9 +/- 0.1 for both relics. We find evidence of a spatial variation in the spectral index across the NW relic steepening towards the centre of the cluster, which indicates an ageing electron population. These properties are consistent with higher frequency observations. We detect emission that could be associated with a radio halo and bridge. How- ever, due to the presence of poorly sampled large-scale Galactic emission and blended point sources we are unable to verify the exact nature of these features.Peer reviewe
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