1,628 research outputs found

    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

    High-density Skyrmion matter and Neutron Stars

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    We examine neutron star properties based on a model of dense matter composed of B=1 skyrmions immersed in a mesonic mean field background. The model realizes spontaneous chiral symmetry breaking non-linearly and incorporates scale-breaking of QCD through a dilaton VEV that also affects the mean fields. Quartic self-interactions among the vector mesons are introduced on grounds of naturalness in the corresponding effective field theory. Within a plausible range of the quartic couplings, the model generates neutron star masses and radii that are consistent with a preponderance of observational constraints, including recent ones that point to the existence of relatively massive neutron stars with mass M 1.7 Msun and radius R (12-14) km. If the existence of neutron stars with such dimensions is confirmed, matter at supra-nuclear density is stiffer than extrapolations of most microscopic models suggest.Comment: 27 pages, 5 figures, AASTeX style; to be published in The Astrophysical Journa

    Do people with intellectual disabilities understand their prescription medication? A scoping review

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    © 2019 The Authors. Journal of Applied Research in Intellectual Disabilities Published by John Wiley & Sons Ltd.Background: People with intellectual disabilities are more likely to experience poor health than the general population and are frequently prescribed multiple medications. Therefore, it is important that people with intellectual disabilities understand their medication and potential adverse effects. Method: A scoping review explored people with intellectual disabilities' knowledge of prescription medications, their risks and how medication understanding can be improved. Results: Ten journal articles were included. People with intellectual disabilities often lacked understanding of their medication, including its name, purpose and when and how to take it. Participants were often confused or unaware of adverse effects associated with their medication. Information was sometimes explained to carers rather than people with intellectual disabilities. Some interventions and accessible information helped to improve knowledge in people with intellectual disabilities. Conclusion: There is a need for accessible and tailored information about medication to be discussed with people with intellectual disabilities in order to meet legal and best practice standards.Peer reviewe

    Radio Pulses along the Galactic Plane

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    We have surveyed 68 deg^2 along the Galactic Plane for single, dispersed radio pulses. Each of 3027 independent pointings was observed for 68 s using the Arecibo telescope at 430 MHz. Spectra were collected at intervals of 0.5 ms and examined for pulses with duration 0.5 to 8 ms. Such single pulse analysis is the most sensitive method of detecting highly scattered or highly dispersed signals from pulsars with large pulse-to-pulse intensity variations. A total of 36 individual pulses from five previously known pulsars were detected, along with a single pulse not associated with a previously known source. Follow-up observations discovered a pulsar, PSR J1918+08, from which the pulse originated. This pulsar has period 2.130 s and dispersion measure 30 pc cm^-3, and has been seen to emit single pulses with strength up to 8 times the average.Comment: 14 pages, 5 figures, AASTeX, accepted by the Astrophysical Journa

    The Probability Distribution of Binary Pulsar Coalescence Rate Estimates. II. Neutron Star-White Dwarf Binaries

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    We consider the statistics of pulsar binaries with white dwarf companions (NS-WD). Using the statistical analysis method developed by Kim et al. (2003) we calculate the Galactic coalescence rate of NS-WD binaries due to gravitational-wave emission. We find that the most likely values for the total Galactic coalescence rate (R_tot) of NS-WD binaries lie in the range 0.2--10 per Myr depending on different assumed pulsar population models. For our reference model, we obtain R_tot=4.11_(-2.56)^(+5.25) per Myr at a 68% statistical confidence level. These rate estimates are not corrected for pulsar beaming and as such they are found to be about a factor of 20 smaller than the Galactic coalescence rate estimates for double neutron star systems. Based on our rate estimates, we calculate the gravitational-wave background due to coalescing NS-WD binaries out to extragalactic distances within the frequency band of the Laser Interferometer Space Antenna. We find the contribution from NS-WD binaries to the gravitational-wave background to be negligible.Comment: 20 pages, 2 figures, 2 tables, Accepted for publication in Ap

    Stability window and mass-radius relation for magnetized strange quark stars

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    The stability of magnetized strange quark matter (MSQM) is investigated within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag parameter. We obtain that the energy per baryon decreases as the magnetic field increases, and its minimum value at vanishing pressure is lower than the value found for SQM. This implies that MSQM is more stable than non-magnetized SQM. Furthermore, the stability window of MSQM is found to be wider than the corresponding one of SQM. The mass-radius relation for magnetized strange quark stars is also derived in this framework.Comment: 12 pages, 6 figures, 3 table
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