2,641 research outputs found

    Heaping and its Consequences for Duration Analysis

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    This paper analyses the consequences of heaping in duration models. Heaping is a specific form of response error typical to retrospectively collected labor force status data. Respondents round-off the spell length, when duration data is collected by episode-based questionnaires. Calendar-based questionnaires instead may lead to abnormal concentrations of the start and/or end of spells at specific calendar months. The investigation concentrates on this latter type of heaping, which Kraus and Steiner [1995] identified for the unemployment spell data from the German Socio-Economic Panel (GSOEP). In the special case of an exponential model heaping with a symmetric zero-mean measurement error does not bias the parameter estimate. In the Weibull model with duration dependence, however, it is proven that even such a symmetric heaping would lead to inconsistent estimation. We discuss the bias for general heaping patterns and derive from this a proposal for bias correction. In a number of simulation studies we check the theoretical results. The Monte Carlo simulations also show that an amount of heaping, that characterizes the GSOEP-West does not lead to considerably biased parameter estimates of a Weibull model. However, it clearly leads to spurious seasonal effects. Finally, some directions of future work are indicated

    The Impact of Depression on Patient Outcomes in Hip Arthroscopic Surgery.

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    Background: Mental health impairments have been shown to negatively affect preoperative self-reported function in patients with various musculoskeletal disorders, including those with femoroacetabular impingement. Hypothesis: Those with symptoms of depression will have lower self-reported function, more pain, and less satisfaction on initial assessment and at 2-year follow-up than those without symptoms of depression. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who were enrolled in a multicenter hip arthroscopic surgery registry and had 2-year outcome data available were included in the study. Patients completed the 12-item International Hip Outcome Tool (iHOT-12), visual analog scale (VAS) for pain, and 12-item Short-Form Health Survey (SF-12) when consenting for surgery. At 2-year follow-up, patients were emailed the iHOT, the VAS, and a rating scale of surgical satisfaction. Initial SF-12 mental component summary (MCS) scores Results: A total of 781 patients achieved the approximate 2-year milestone (mean follow-up, 735 ± 68 days), with 651 (83%) having 2-year outcome data available. There were 434 (67%) female and 217 (33%) male patients, with a mean age of 35.8 ± 13.0 years and a mean body mass index of 25.4 ± 8.8 kg/m Conclusion: A large number of patients who underwent hip arthroscopic surgery presented with symptoms of depression, which negatively affected self-reported function, pain levels, and satisfaction on initial assessment and at 2-year follow-up. Surgeons who perform hip arthroscopic surgery may need to identify the symptoms of depression and be aware of the impact that depression can have on surgical outcomes

    Single-crystal X-ray diffraction and resonant X-ray magnetic scattering at helium-3 temperatures in high magnetic fields at beamline P09 at PETRA III

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    The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split-pair magnet. A helium-3 refrigerator is available that can be fitted inside the magnet\u27s variable-temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He-3 insert are presented. By measuring the tetragonal-to-orthorhombic phase transition occurring at 2.1 K in the Jahn-Teller compound TmVO4, it is found that the photon flux at P09 must be attenuated down to 1.5 × 109 photons s-1 for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X-ray magnetic scattering signal at the Tm LIII absorption edge associated with the spin-density wave in TmNi2B2C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub-Kelvin temperatures to be carried out

    Moral wrongs, disadvantages, and disability: a critique of critical disability studies

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    Critical disability studies (CDS) has emerged as an approach to the study of disability over the last decade or so and has sought to present a challenge to the predominantly materialist line found in the more conventional disability studies approaches. In much the same way that the original development of the social model resulted in a necessary correction to the overly individualized accounts of disability that prevailed in much of the interpretive accounts which then dominated medical sociology, so too has CDS challenged the materialist line of disability studies. In this paper we review the ideas behind this development and analyse and critique some of its key ideas. The paper starts with a brief overview of the main theorists and approaches contained within CDS and then moves on to normative issues; namely, to the ethical and political applicability of CDS

    Building Community Practice Competencies Globally through the Community Tool Box

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    People throughout the world are working together to improve conditions in which they live. Although the issues and resources vary by context, what people actually do to effect change—core competencies of assessment, planning, action, evaluation, and sustainability—may be quite similar. To examine what competencies may be most valued in community practice, this report uses data analytics for what users are accessing in the Community Tool Box http://ctb.ku.edu/. This free resource for community health and development, with over 1.7 million unique visitors annually from over 200 countries, showed a six-fold increase in users during the past year (from November 2011 to November 2012). When we examined what users were accessing, the results showed greater interest in some particular competencies such as assessing community needs and resources, developing strategic and action plans, and enhancing cultural competence. Patterns of use suggest that there may be core competencies valued by community members seeking to change conditions and outcomes that matter, which may help inform training and professional development for the millions of people worldwide working to promote health, human development, and social justice.&nbsp

    Building Community Practice Competencies Globally through the Community Tool Box

    Get PDF
    People throughout the world are working together to improve conditions in which they live. Although the issues and resources vary by context, what people actually do to effect change—core competencies of assessment, planning, action, evaluation, and sustainability—may be quite similar. To examine what competencies may be most valued in community practice, this report uses data analytics for what users are accessing in the Community Tool Box http://ctb.ku.edu/. This free resource for community health and development, with over 1.7 million unique visitors annually from over 200 countries, showed a six-fold increase in users during the past year (from November 2011 to November 2012). When we examined what users were accessing, the results showed greater interest in some particular competencies such as assessing community needs and resources, developing strategic and action plans, and enhancing cultural competence. Patterns of use suggest that there may be core competencies valued by community members seeking to change conditions and outcomes that matter, which may help inform training and professional development for the millions of people worldwide working to promote health, human development, and social justice.&nbsp

    Long-term safety and stability of angiogenesis induced by balanced single-vector co-expression of PDGF-BB and VEGF164 in skeletal muscle

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    Therapeutic angiogenesis by growth factor delivery is an attractive treatment strategy for ischemic diseases, yet clinical efficacy has been elusive. The angiogenic master regulator VEGF-A can induce aberrant angiogenesis if expressed above a threshold level. Since VEGF remains localized in the matrix around expressing cells, homogeneous dose distribution in target tissues is required, which is challenging. We found that co-expression of the pericyte-recruiting factor PDGF-BB at a fixed ratio with VEGF from a single bicistronic vector ensured normal angiogenesis despite heterogeneous high VEGF levels. Taking advantage of a highly controlled gene delivery platform, based on monoclonal populations of transduced myoblasts, in which every cell stably produces the same amount of each factor, here we rigorously investigated a) the dose-dependent effects, and b) the long-term safety and stability of VEGF and PDGF-BB co-expression in skeletal muscle. PDGF-BB co-expression did not affect the normal angiogenesis by low and medium VEGF doses, but specifically prevented vascular tumors by high VEGF, yielding instead normal and mature capillary networks, accompanied by robust arteriole formation. Induced angiogenesis persisted unchanged up to 4 months, while no tumors appeared. Therefore, PDGF-BB co-expression is an attractive strategy to improve safety and efficacy of therapeutic angiogenesis by VEGF gene delivery

    Gemini Planet Imager Observational Calibrations VI: Photometric and Spectroscopic Calibration for the Integral Field Spectrograph

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    The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini Observatory designed to provide direct detection and characterization of planets and debris disks around stars in the solar neighborhood. In addition to its extreme adaptive optics and corona graphic systems which give access to high angular resolution and high-contrast imaging capabilities, GPI contains an integral field spectrograph providing low resolution spectroscopy across five bands between 0.95 and 2.5 μ\mum. This paper describes the sequence of processing steps required for the spectro-photometric calibration of GPI science data, and the necessary calibration files. Based on calibration observations of the white dwarf HD 8049B we estimate that the systematic error in spectra extracted from GPI observations is less than 5%. The flux ratio of the occulted star and fiducial satellite spots within coronagraphic GPI observations, required to estimate the magnitude difference between a target and any resolved companions, was measured in the HH-band to be Δm=9.23±0.06\Delta m = 9.23\pm0.06 in laboratory measurements and Δm=9.39±0.11\Delta m = 9.39\pm 0.11 using on-sky observations. Laboratory measurements for the YY, JJ, K1K1 and K2K2 filters are also presented. The total throughput of GPI, Gemini South and the atmosphere of the Earth was also measured in each photometric passband, with a typical throughput in HH-band of 18% in the non-coronagraphic mode, with some variation observed over the six-month period for which observations were available. We also report ongoing development and improvement of the data cube extraction algorithm.Comment: 15 pages, 6 figures. Proceedings of the SPIE, 9147-30
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