79 research outputs found

    On the evolutionary behaviour of BL Lac objects

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    We present a new well defined sample of BL Lac objects selected from the ROSAT All-Sky Survey (RASS). The sample consists of 39 objects with 35 forming a flux limited sample down to f_X = 8 x 10^{-13} cgs, redshifts are known for 33 objects (and 31 of the complete sample). X-ray spectral properties were determined for each object individually with the RASS data. The luminosity function of RASS selected BL Lac objects is compatible with results provided by objects selected with the Einstein observatory, but the RASS selected sample contains objects with luminosities at least tenfold higher. Our analysis confirms the negative evolution for X-ray selected BL Lac objects found in a sample by the Einstein observatory, the parameterization provides similar results. A subdivision of the sample into halves according to the X-ray to optical flux ratio yielded unexpected results. The extremely X-ray dominated objects have higher redshifts and X-ray luminosities and only this subgroup shows clear signs of strong negative evolution. The evolutionary behaviour of objects with an intermediate spectral energy distribution between X-ray and radio dominated is compatible with no evolution at all. Consequences for unified schemes of X-ray and radio selected BL Lac objects are discussed.We suggest that the intermediate BL Lac objects are the basic BL Lac population. The distinction between the two subgroups can be explained if extreme X-ray dominated BL Lac objects are observed in a state of enhanced X-ray activity.Comment: 14 pages incl. 8 figures, accepted by A&

    Hearing the voices of older adult patients: processes and findings to inform health services research

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    Background Clinical academic research and service improvement is planned using Patient and Public Involvement and Engagement (PPIE) but older PPIE participants are consulted less often due to the perception that they are vulnerable or hard to engage. Objectives To consult frail older adults about a recently adopted service, discharge to assess (D2A), and to prioritise services improvements and research topics associated with the design and delivery of discharge from hospital. To use successive PPIE processes to enable a permanent PPIE panel to be established. Participants Following guidance from an established hospital PPI panel 27 older adult participants were recruited. Participants from Black, Asian and Minority Ethnic (BAME) communities, affluent and non-affluent areas and varied social circumstances were included. Methods Focus groups and individual interviews were conducted in participants own homes or nearby social venues. Results Priorities for discharge included remaining independent despite often feeling lonely at home; to remain in hospital if needed; and for services to ensure effective communication with families. The main research priority identified was facilitating independence, whilst establishing a permanent PPIE panel involving older adults was viewed favourably. Conclusions Taking a structured approach to PPIE enabled varied older peoples’ voices to express their priorities and concerns into early discharge from hospital, as well as enabling the development of health services research into hospital discharge planning and management. Older people as participants identified research priorities after reflecting on their experiences. Listening and reflection enabled researchers to develop a new “Community PPIE Elders Panel” to create an enduring PPIE infrastructure for frail older housebound people to engage in research design, development and dissemination

    Vulnerable Children, Young People, and Families: Policy, Practice, and Social Justice in England and Scotland

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    This chapter begins by highlighting the rise of vulnerability as a term in social policy, and the three-level approach that is used to examine it. The first level is definitional, examining the possibility of defining vulnerability and vulnerabilities through a consideration of relevant literature and a number of recent policy documents. The second looks at how policy developments in Scotland and England have diverged, particularly since 2010, and how vulnerability has become more central to education policy in England. The third level focuses on practice, presenting research undertaken by the authors into a programme developed to support vulnerable children, young people, and families in Northern England as a case study exemplifying some of the factors affecting the effectiveness of programmes in which schools played an important but not central part. This practice perspective is still too often overlooked in discussions of policy and definition, and it is suggested that its inclusion will contribute to the ongoing debate about both how best to support vulnerable families and the implications for education and social justice
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