6,358 research outputs found

    High-performance thermionic converter Quarterly progress report, 13 Nov. 1965 - 13 Feb. 1966

    Get PDF
    Stability and optimization parameters of cesium vapor thermionic converters studied in high performance long life equipment fabrication projec

    An introduction to overviews of reviews: planning a relevant research question and objective for an overview.

    Get PDF
    This is the final version of the article. Available from the publisher via the DOI in this record.BACKGROUND: Overviews of systematic reviews are a relatively new approach to synthesising evidence, and research methods and associated guidance are developing. Within this paper we aim to help readers understand key issues which are essential to consider when taking the first steps in planning an overview. These issues relate to the development of clear, relevant research questions and objectives prior to the development of an overview protocol. METHODS: Initial discussions and key concepts for this paper were formed during a workshop on overview methods at the 2016 UK Cochrane Symposium, at which all members of this author group presented work and contributed to wider discussions. Detailed descriptions of the various key features of overviews and their different objectives were created by the author group based upon current evidence (Higgins J, Green S. Cochrane Handbook Syst Rev Interv. 2011;4:5, Pollock M, et al. Sys Rev. 2016;5:190-205, Pollock A, et al. Cochrane overviews of reviews: exploring the methods and challenges. UK and Ireland: Cochrane Symposium; 2016, Pieper D, et al. Res Syn Meth. 2014;5:187-99, Lunny C, et al. Sys Rev. 2016;5:4-12, Hartling L, et al. Comparing multiple treatments: an introduction to overviews of reviews. In 23rd Cochrane Colloquium; 2015, Hartling L, et al. Plos One. 2012;7:1-8, Ballard M, Montgomery P. Res Syn Meth. 2017;8:92-108) and author experiences conducting overviews. RESULTS: Within this paper we introduce different types of overviews and suggest common research questions addressed by these overviews. We briefly reflect on the key features and objectives of the example overviews discussed. CONCLUSIONS: Clear decisions relating to the research questions and objectives are a fundamental first step during the initial planning stages for an overview. Key stakeholders should be involved at the earliest opportunity to ensure that the planned overview is relevant and meaningful to the potential end users of the overview. Following best practice in common with other forms of systematic evidence synthesis, an overview protocol should be published, ensuring transparency and reducing opportunities for introduction of bias in the conduct of the overview.Research conducted by Harriet Hunt referred to within this paper [38] was supported as part of doctoral programme funding by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula (PenCLAHRC). The overview conducted by Pollock [3] was supported by a project grant from the Chief Scientist Office of the Scottish Government. The overview conducted by McClurg [5] was supported by a project grant by the Physiotherapy Research Foundation. Alex Pollock is employed by the Nursing, Midwifery and Allied Health Professions (NMAHP) Research Unit, which is supported by the Chief Scientist Office of the Scottish Government. Pauline Campbell is supported by the Chief Nurses Office of the Scottish Government. The overview conducted by Estcourt [7] was supported by an NIHR Cochrane Programme Grant for the Safe and Appropriate Use of Blood Components. The overview conducted by Brunton [10] was commissioned by the Department of Health as part of an ongoing programme of work on health policy research synthesis

    Correlates of Mental Health and Psychological Well-being of the European Youth: evidence from the European Quality of Life Survey

    Get PDF
    Youth well-being is becoming more central to European social policies both in the EU and at a national level. The study of well being has come far in recent years such that the focus has shifted from understandings with a focus on objective measures towards a nuanced analyses including a variety of social and psychological dimensions. At the same time, there have been significant advances in the development of common research instruments and cross-national surveys, both of which facilitate a comparative analysis of well-being. This paper uses evidence from the European Quality of Life Survey 2011 to highlight national differences in mental health and psychological well-being and begins the process of establishing which factors appear to predict positive experiences

    Search for periodicities near 59 s in the COS-B gamma-ray data of 2CG195+04 (Geminga)

    Get PDF
    The COS-B data relating to five observations in the general direction of Geminga, spanning 6.7 years, were searched for pulsation near 59 s. The SAS-2 indication is not confirmed. An indication of a 59 s pulsation in the gamma ray emission from 2CG195+04 (Geminga) was reported. Early analysis of COS-B data supported the result while later improved statistics did not confirm it. Subsequently, detection of a 59 s pulsation in the emission from the direction of Geminga at ultra high gamma and X-rays was reported. Geminga was identified with the X-ray source 1E0630+128. The final COS-B data on Geminga which was observed five times for a total of 214 days are reported

    Worm algorithms for classical statistical models

    Get PDF
    We show that high-temperature expansions may serve as a basis for the novel approach to efficient Monte Carlo simulations. "Worm" algorithms utilize the idea of updating closed path configurations (produced by high-temperature expansions) through the motion of end points of a disconnected path. An amazing result is that local, Metropolis-type schemes may have dynamical critical exponents close to zero (i.e., their efficiency is comparable to the best cluster methods). We demonstrate this by calculating finite size scaling of the autocorrelation time for various (six) universality classes.Comment: 4 pages, latex, 2 figure

    Cyg X-3: Not seen in high-energy gamma rays by COS-B

    Get PDF
    COS-B had Cyg X-3 within its field of view during 7 observation periods between 1975 and 1982 for in total approximately 300 days. In the skymaps (70 meV E 5000 meV) of the Cyg-X region produced for each of these observations and in the summed map, a broad complex structure is visible in the region 72 deg approximately less than 1 approximately less than 85 deg, approximately less than 5 deg. No resolved source structure is visible at the position of Cyg X-3, but a weak signal from Cyg X-3 could be hidden in the structured gamma-ray background. Therefore, the data has been searched for a 4.8 h timing signature, as well as for a source signal in the sky map in addition to the diffuse background structure as estimated from tracers of atomic and molecular gas

    Ground-state dispersion and density of states from path-integral Monte Carlo. Application to the lattice polaron

    Full text link
    A formula is derived that relates the ground-state dispersion of a many-body system with the end-to-end distribution of paths with open boundary conditions in imaginary time. The formula does not involve the energy estimator. It allows direct measurement of the ground-state dispersion by quantum Monte Carlo methods without analytical continuation or auxiliary fitting. The formula is applied to the lattice polaron problem. The exact polaron spectrum and density of states are calculated for several models in one, two, and three dimensions. In the adiabatic regime of the Holstein model, the polaron density of states deviates spectacularly from the free-particle shape.Comment: 8 pages, 9 figure

    Erratum to: The Current Evidence Base and Future Needs in Improving Children’s Well-Being Across Europe: is There a Case for a Comparative Longitudinal Survey? (Child Indicators Research, (2016), 9, 2, (371-388), 10.1007/s12187-015-9323-5)

    Get PDF
    © Springer Science+Business Media Dordrecht 2017. Erratum to: Child Ind Res (2016) 9:371–388 DOI 10.1007/s12187–015–9323-5. The article The Current Evidence Base and Future Needs in Improving Children’s Well-Being Across Europe: is There a Case for a Comparative Longitudinal Survey?, written by [Haridhan Goswami, Christopher Fox and Gary Pollock], was originally published Online First without open access. After publication in volume [9] , issue [2], page [371-388] the author decided to opt for Open Choice and to make the article an open access publication. Therefore, the copyright of the article has been changed to © The Author(s) [2016] and the article is forthwith distributed under the terms of the Creative Commons Attribution

    The Current Evidence Base and Future Needs in Improving Children’s Well-Being Across Europe: is There a Case for a Comparative Longitudinal Survey?

    Get PDF
    There has been a growing interest among academics, policy makers and practitioners in the subjective well-being of children and young people (CYP). The recognition of CYP’s rights to having a good childhood and good future life chances, coupled with the injunction from the New Sociology of Childhood to consult with CYP as active agents have also resulted in an increasing interest in the use of well-being as a key concept in policy programmes in many countries. In recent years, child well-being has become a priority for the European political agenda. However, the main challenge for the European Union (EU) is to develop the best policies and approaches to effectively improve the well-being of children and young people using the most robust and suitable sources of data. This article identifies research gaps on children and young people’s subjective well-being and discusses the policy relevance of longitudinal survey in the context of the EU strategy for CYP. It is argued that a longitudinal survey would fulfil research gaps and provide invaluable data for the European Union and its member states for monitoring and evaluation of existing policies on children and young people’s well-being and developing future polices supported by robust data
    • …
    corecore