4,810 research outputs found

    The Properties of Poor Groups of Galaxies: II. X-ray and Optical Comparisons

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    We use ROSAT PSPC data to study the X-ray properties of a sample of twelve poor groups that have extensive membership information (Zabludoff and Mulchaey 1997; Paper I). Diffuse X-ray emission is detected in nine of these groups. In all but one of the X-ray detected groups, the X-ray emission is centered on a luminous elliptical galaxy. Fits to the surface brightness profiles of the X-ray emission suggest the presence of two X-ray components in these groups. The first component is centered on the central elliptical galaxy. The location and extent of this component, combined with its X-ray temperature and luminosity, favor an origin in the interstellar medium of the central galaxy. Alternatively, the central component may be the result of a large-scale cooling flow. The second X-ray component is detected out to a radius of at least 100-300 kpc. This component follows the same relationships found among the X-ray temperature, X-ray luminosity and optical velocity dispersion of rich clusters. This result suggests that the X-ray detected groups are low-mass versions of clusters and that the extended gas component can properly be called the intragroup medium, in analogy to the intracluster medium in clusters. We also find a trend for the position angle of the optical light in the central elliptical galaxy to align with the position angle of the large-scale X-ray emission. (Abridged)Comment: 38 pages, AASLaTeX with 16 PS figures. Figure 1a-1l available in gzipped postscript format at ftp://corvus.ociw.edu/pub/mulchae

    Anthropomorphic Simulations of Falls, Shakes, and Inflicted Impacts in Infants

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    Object: Rotational loading conditions have been shown to produce subdural hemorrhage and diffuse axonal injury. No experimental data are available with which to compare the rotational response of the head of an infant during accidental and inflicted head injuries. The authors sought to compare rotational deceleration sustained by the head among free falls, from different heights onto different surfaces, with those sustained during shaking and inflicted impact. Methods: An anthropomorphic surrogate of a 1.5-month-old human infant was constructed and used to simulate falls from 0.3 m (1 ft), 0.9 m (3 ft), and 1.5 m (5 ft), as well as vigorous shaking and inflicted head impact. During falls, the surrogate experienced occipital contact against a concrete surface, carpet pad, or foam mattress. For shakes, investigators repeatedly shook the surrogate in an anteroposterior plane; inflicted impact was defined as the terminal portion of a vigorous shake, in which the surrogate‚Äôs occiput made contact with a rigid or padded surface. Rotational velocity was recorded directly and the maximum (peak‚Äďpeak) change in angular velocity ( max) and the peak angular acceleration ( max) were calculated. Analysis of variance revealed significant increases in the max and max associated with falls onto harder surfaces and from higher heights. During inflicted impacts against rigid surfaces, the max and max were significantly greater than those measured under all other conditions. Conclusions: Vigorous shakes of this infant model produced rotational responses similar to those resulting from minor falls, but inflicted impacts produced responses that were significantly higher than even a 1.5-m fall onto concrete. Because larger accelerations are associated with an increasing likelihood of injury, the findings indicate that inflicted impacts against hard surfaces are more likely to be associated with inertial brain injuries than falls from a height less than 1.5 m or from shaking

    Enhancing the Prospects for Palliative Care at the End of Life: A Statewide Educational Demonstration Project to Improve Advance Care Planning

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    Although patients want to participate in discussions and decisions about their end-of-life care, studies show that providers frequently fail to invite them to explore advanced care preferences or goals for living. The purpose of our demonstration project was to provide education and coaching to individuals, health providers, and organizations across the state of Indiana intended to facilitate these conversations, documenting and honoring individuals' life goals and preferences for care during the final stages of life. Education and training engaged community members as well as healthcare providers to: (1) improve participant comfort and facility discussing end-of-life issues; (2) improve knowledge of healthcare choices, including palliative and hospice care; and (3) prepare all participants to explore and document personal values, life goals, and priorities as well as goals of care. Between January of 2013 and June of 2015, the team educated close to 5,000 participants. Participants' ratings of the quality and perceived usefulness of the educational events ranged from 4 to 5 (using a 5-point scale, with 5 = most effective). Participant comments were overwhelmingly favorable and indicated an intention to put the advance care planning resources, communication skills, knowledge of palliative and hospice care, and personal renewal techniques into practice. Participant motivation to foster advance care planning, discussions of palliative care, and end-of-life conversations was facilitated by the reframing of these conversations as identifying goals of care and priorities for living well during an important stage of life. Successful strategies included helping providers and patients to adopt a broader meaning for ‚Äúsustaining hope‚ÄĚ (not for cure, but for engaging in highly valued activities), developing provider communication skills and comfort in initiating potentially difficult discussions, engaging a new community health workforce who will develop trusting relationships with patients in home-based services, and fostering self-awareness and self-care among palliative care providers

    Observation of Single Top Quark Production

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    The field of experimental particle physics has become more sophisticated over time, as fewer, larger experimental collaborations search for small signals in samples with large components of background. The search for and the observation of electroweak single top quark production by the CDF and DZero collaborations at Fermilab's Tevatron collider are an example of an elaborate effort to measure the rate of a very rare process in the presence of large backgrounds and to learn about the properties of the top quark's weak interaction. We present here the techniques used to make this groundbreaking measurement and the interpretation of the results in the context of the Standard Model.Comment: 33 pages, 14 figures, 4 tables, to appear in Annual Review of Nuclear and Particle Science, Vol. 61, November 201

    Preclinical detection of infectivity and disease-specific PrP in blood throughout the incubation period of prion disease.

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    Variant Creutzfeldt-Jakob disease (vCJD) is a fatal neurodegenerative disorder characterised by accumulation of pathological isoforms of the prion protein, PrP. Although cases of clinical vCJD are rare, there is evidence there may be tens of thousands of infectious carriers in the United Kingdom alone. This raises concern about the potential for perpetuation of infection via medical procedures, in particular transfusion of contaminated blood products. Accurate biochemical detection of prion infection is crucial to mitigate risk and we have previously reported a blood assay for vCJD. This assay is sensitive for abnormal PrP conformers at the earliest stages of preclinical prion disease in mice and precedes the maximum infectious titre in blood. Not only does this support the possibility of screening asymptomatic individuals, it will also facilitate the elucidation of the complex relationship that exists between the ensemble of abnormal PrP conformers present in blood and the relationship to infectivity

    Resisting the Coloniality and Colonialism of a Westernized Community Psychology: Toward a Critical Racial Justice Praxis

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    The institutional violence we are now experiencing, coupled with historical and ongoing waves of oppression, is a result and continuation of the legacy of colonialism. The outward eruptions that we are seeing over the last years are a result of American and Canadian settler nation-states that have taken hold in North America but are now in decline. Yet, the perpetuation of imperialism and white supremacist ideologies via the academe and other noneducational entities reproduced through curricula, pedagogy, and institutional policies and practices must still be addressed. The discipline of community psychology (CP) is no exception. As a part of the imperialist empire, CP, a mainstream academic discipline born at the heart of the empire of the colonial ruling class, continuously asks: What can we do? We, the authors of this paper, are troubled by this question and respond with a question of our own: Can community psychology really be part of the solution if it does not acknowledge that it is part of the problem? Through the lens of five Indigenous, Black, and racialized scholar-activists, educators, and practitioners, we identify three community psychology principles and argue that in practice within Black and Indigenous communities, they are not sufficient. Further, we illustrate that, related to these principles, community psychology is situated within what is termed the industrial complex, and we elucidate the implications of this situating. Lastly, we offer a proposal for how we, as part of the academe and practice, can decolonize community psychology and move it forward to align with current liberation movements and Indigenous sovereignty

    Evidence for Nodal Superconductivity in LaFePO from Scanning SQUID Susceptometry

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    We measure changes in the penetration depth őĽ\lambda of the Tc‚Čą6T_c \approx 6 K superconductor LaFePO. In the process scanning SQUID susceptometry is demonstrated as a technique for accurately measuring {\it local} temperature-dependent changes in őĽ\lambda, making it ideal for studying early or difficult-to-grow materials. őĽ\lambda of LaFePO is found to vary linearly with temperature from 0.36 to ‚ąľ\sim2 K, with a slope of 143¬Ī\pm15 \AA/K, suggesting line nodes in the superconducting order parameter. The linear dependence up to ‚ąľTc/3\sim T_c/3 is similar to the cuprate superconductors, indicating well-developed nodes.Comment: 4 pages, 5 figure

    TeraGrid User Workshop Final Report

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    In 2006, the NSF awarded a one-year grant to the University of Michigan’s School of Information (UM-SI) to conduct an external evaluation of TeraGrid. This report describes the results of the first major evaluation activity. On June 12, 2006 the UM-SI evaluation team conducted a workshop to begin to examine the relationship between TeraGrid’s development priorities and the needs of its users. The invitation-only workshop was funded by TeraGrid and was held at the University Place Conference Center in Indianapolis, Indiana. The TeraGrid User Workshop Final Report summarizes the data collected and information gained during the workshop.National Science Foundationhttp://deepblue.lib.umich.edu/bitstream/2027.42/61841/1/TeraGrid2006_Tutortials_Survey_Report.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/61841/4/2006_TGUser_Workshop_Report.pd
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