2,871 research outputs found

    Timing Measurements of the Relativistic Binary Pulsar PSR B1913+16

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    We present results of more than three decades of timing measurements of the first known binary pulsar, PSR B1913+16. Like most other pulsars, its rotational behavior over such long time scales is significantly affected by small-scale irregularities not explicitly accounted for in a deterministic model. Nevertheless, the physically important astrometric, spin, and orbital parameters are well determined and well decoupled from the timing noise. We have determined a significant result for proper motion, μα=−1.43±0.13\mu_{\alpha} = -1.43\pm0.13, μδ=−0.70±0.13\mu_{\delta}=-0.70\pm0.13 mas yr−1^{-1}. The pulsar exhibited a small timing glitch in May 2003, with Δf/f=3.7×10−11{\Delta f}/f=3.7\times10^{-11}, and a smaller timing peculiarity in mid-1992. A relativistic solution for orbital parameters yields improved mass estimates for the pulsar and its companion, m_1=1.4398\pm0.0002 \ M_{\sun} and m_2=1.3886\pm0.0002 \ M_{\sun}. The system's orbital period has been decreasing at a rate 0.997±0.0020.997\pm0.002 times that predicted as a result of gravitational radiation damping in general relativity. As we have shown before, this result provides conclusive evidence for the existence of gravitational radiation as predicted by Einstein's theory.Comment: Published in APJ, 722, 1030 (2010

    Neutron-Rich Nuclei in Heaven and Earth

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    An accurately calibrated relativistic parametrization is introduced to compute the ground state properties of finite nuclei, their linear response, and the structure of neutron stars. While similar in spirit to the successful NL3 parameter set, it produces an equation of state that is considerably softer -- both for symmetric nuclear matter and for the symmetry energy. This softening appears to be required for an accurate description of several collective modes having different neutron-to-proton ratios. Among the predictions of this model are a symmetric nuclear-matter incompressibility of K=230 MeV and a neutron skin thickness in 208Pb of Rn-Rp=0.21 fm. Further, the impact of such a softening on the properties of neutron stars is as follows: the model predicts a limiting neutron star mass of Mmax=1.72 Msun, a radius of R=12.66 km for a ``canonical'' M=1.4 Msun neutron star, and no (nucleon) direct Urca cooling in neutrons stars with masses below M=1.3 Msun.Comment: 4 pages, 3 tables, and no figure

    Depoliticisation, Resilience and the Herceptin Post-code Lottery Crisis: Holding Back the Tide

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    This article: Covers new empirical terrain in the study of depoliticisation, with an in-depth case study of health technology regulation; Analyses depoliticisation from a novel analytical perspective, examining how depoliticised institutions are resilient to external pressure for politicisation; Posits a distinctive framework for analysing resilience, drawing on cognate literatures on policy networks and agencification; Raises interesting and distinctive questions about the nature of depoliticisation in advanced liberal democracies, arguing it is more contested than commonly acknowledged. Depoliticisation as a concept offers distinctive insights into how governments attempt to relieve political pressures in liberal democracies. Analysis has examined the effects of depoliticisation tactics on the public, but not how those tactics are sustained during moments of political tension. Drawing on policy networks and agencification literatures, this article examines how these tactics are resilient against pressure for politicisation. Using an in-depth case study of the controversial appraisal of cancer drug Herceptin in 2005/6 by the National Institute for Health and Clinical Excellence (NICE), the article examines how ‘resilient’ NICE was to external politicisation. It is argued that NICE was resilient because it was effectively ‘insulated’ by formal procedures and informal norms of deference to scientific expertise. This mechanism is termed ‘institutional double glazing’. The conclusion suggests developments to the conceptual and methodological framework of depoliticisation, and highlights theoretical insights into the nature of ‘anti-politics’ in contemporary democracies

    Market access agreements for pharmaceuticals in Europe: diversity of approaches and underlying concepts

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    <p>Abstract</p> <p>Background</p> <p>Market Access Agreements (MAA) between pharmaceutical industry and health care payers have been proliferating in Europe in the last years. MAA can be simple discounts from the list price or very sophisticated schemes with inarguably high administrative burden.</p> <p>Discussion</p> <p>We distinguished and defined from the health care payer perspective three kinds of MAA: Commercial Agreements (CA), Payment for Performance Agreements (P4P) and Coverage with Evidence Development (CED). Apart from CA, the agreements assumed collection and analysis of real-life health outcomes data, either from a cohort of patients (CED) or on per patient basis (P4P). We argue that while P4P aim at reducing drug cost to payers without a systematic approach to addressing uncertainty about drugs' value, CED were implemented provisionally to reduce payer's uncertainty about value of a medicine within a defined time period.</p> <p>Summary</p> <p>We are of opinion that while CA and P4P have a potential to reduce payers' expenditure on costly drugs while maintaining a high list price, CED address initial uncertainty related to assessing the real-life value of new drugs and enable a final HTA recommendation or reimbursement and pricing decisions. Further, we suggest that real cost to health care payers of drugs in CA and P4P should be made publicly available in a systematic manner, to avoid a perverse impact of these MAA types on the international reference pricing system.</p
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