14,994 research outputs found

    The use of ASBOs against young people in England and Wales: lessons from Scotland

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    The Anti-Social Behaviour Order (ASBO) is one of the best known measures used to tackle anti-social behaviour. In keeping with the popular conception, the order is frequently used against young people. Of all ASBOs issued in England and Wales up to the end of 2005, roughly 40% were imposed on under-18s. This paper begins with a brief outline of the three principles at the heart of the celebrated Scottish children’s hearings system. With reference to these principles, and to the provisions which govern the use of the order against 12–15 year olds north of the border, the paper then discusses five areas of concern about the use of ASBOs against young people in England and Wales: the readiness to resort to ASBOs; the forum for ASBO applications; the terms of ASBOs; publicising the details of ASBOs; and custodial net-widening. The paper ends by suggesting reforms to the ASBO regime in England and Wales insofar as it is used against young people.<br/

    Luminosity Functions of Lyman Alpha Emitting Galaxies and Cosmic Reionization of Hydrogen

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    Recent observations imply that the observed number counts of Lya Emitters (LAEs) evolved significantly between z=5.7 and z=6.5. It has been suggested that this was due to a rapid evolution in the ionisation state, and hence transmission of the IGM which caused Lya flux from z=6.5 galaxies to be more strongly suppressed. In this paper we consider the joint evolution of the Lya and UV luminosity functions (LFs) and show that the IGM transmission evolved between z=6.5 and z=5.7 by a factor 1.1 <R < 1.8 (95% CL). This result is insensitive to the underlying model of the Lya LF (as well as cosmic variance). Using a model for IGM transmission, we find that the evolution of the mean IGM density through cosmic expansion alone may result in a value for the ratio of transmissions as high as R=1.3. Thus, the existing LFs do not provide evidence for overlap. Furthermore, the constraint R<1.8 suggests that the Universe at z=6.5 was more than half ionised by volume, i.e. x_i,V>0.5.Comment: MNRAS in press. Constraints from rest-frame UV LF added. Discussion added on cosmic variance. Lower limit on x_i,V lowered to 0.5 (from 0.8

    The use of graphics in the design of the human-telerobot interface

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    The Man-Systems Telerobotics Laboratory (MSTL) of NASA's Johnson Space Center employs computer graphics tools in their design and evaluation of the Flight Telerobotic Servicer (FTS) human/telerobot interface on the Shuttle and on the Space Station. It has been determined by the MSTL that the use of computer graphics can promote more expedient and less costly design endeavors. Several specific examples of computer graphics applied to the FTS user interface by the MSTL are described

    New measurements of the far ultraviolet scattering properties of interstellar dust

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    An analysis is presented for the spectra of the diffuse ultraviolet background taken during shuttle flight STS-61C (January 1986). Eight regions of the sky were observed for approximately 20 minutes each, using a spectrograph designed specifically to perform measurements of the UV background. The field of view was 3.8 deg x 8 min, with imaging along the slit to confine stellar contamination. The instrument featured a shutter mechanism to measure internal background during flight, a low-scatter holographically ruled diffraction grating, photon counting microchannel plate detectors, through baffling, and a crystal window to further attenuate stray light. The spectra covered the range 1400 to 1850 A and was binned in 50 A bands. The procedure for substracting the contribution of stars too faint to be detected as discrete sources during the observations (in general this represents a small fraction of the total intensity detected except at the longest wavelengths). A radiative transfer model used to interpret the data and set confidence intervals on the relevant parameters is described. It was found that the continuum component of the diffuse ultraviolet background arises primarily from two sources. One source is scattering of starlight by interstellar dust with an albedo of about 12 percent and a relatively isotropic phase function. A second source consists of about 150 photons/cm/sec/ster/A of extragalactic light which is attenuated by the dust in the galaxy. Although emission features possibly associated with molecular H2 are detected in one look direction, fluorescence of H2 is not a major contributor to the diffuse UV background, at least at galactic latitudes greater than -10 degrees

    Research on Social Engagement with a Rabbitic User Interface

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    Companions as interfaces to smart rooms need not only to be easy to interact with, but also to maintain long-term relationships with their users. The FP7-funded project SERA (Social Engagement with Robots and Agents) contributes to knowledge about and modeling of such relationships. One focal activity is an iterative field study to collect real-life long-term interaction data with a robotic interface. The first stage of this study has been completed. This paper reports on the set-up and the first insights

    Fluctuations in the High-Redshift Lyman-Werner Background: Close Halo Pairs as the Origin of Supermassive Black Holes

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    The earliest generation of stars and black holes must have established an early 'Lyman-Werner' background (LWB) at high redshift, prior to the epoch of reionization. Because of the long mean free path of photons with energies E<13.6 eV, the LWB was nearly uniform. However, some variation in the LWB is expected due to the discrete nature of the sources, and their highly clustered spatial distribution. In this paper, we compute the probability distribution function (PDF) of the LW flux that irradiates dark matter (DM) halos collapsing at high-redshift (z~10). Our model accounts for (i) the clustering of DM halos, (ii) Poisson fluctuations in the number of corresponding star forming galaxies, and (iii) scatter in the LW luminosity produced by halos of a given mass (calibrated using local observations). We find that > 99% of the DM halos are illuminated by a LW flux within a factor of 2 of the global mean value. However, a small fraction, ~1e-8 to 1e-6, of DM halos with virial temperatures above 1e4 K have a close luminous neighbor within < 10 kpc, and are exposed to a LW flux exceeding the global mean by a factor of > 20, or to J_(21,LW)> 1e3 (in units of 1e-21 erg/s/Hz/sr/cm^2). This large LW flux can photo--dissociate H_2 molecules in the gas collapsing due to atomic cooling in these halos, and prevent its further cooling and fragmentation. Such close halo pairs therefore provide possible sites in which primordial gas clouds collapse directly into massive black holes (M_BH~ 1e4 - 1e6 M_sun), and subsequently grow into supermassive (M_BH > 1e9 M_sun) black holes by z~6.Comment: 13 pages, 8 figures, Accepted to MNRA

    A Bridge over Troubled Water: The Role of the British Advisory, Conciliation and Arbitration Service (ACAS) in Facilitating Labour-Management Consultation in Public Sector Transformation

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    The aim of this paper is to examine the changing role of the state in a more market-driven system of industrial relations, specifically in terms of the new roles that are being developed with regard to mediation, advisory and arbitration services. It focuses empirically on the role played by the British Advisory, Conciliation and Arbitration Service (ACAS) in facilitating the modernisation of public sector employment relations. We show how ACAS has played a ‘benchmarking’ role that assists the development of more strategic forms of decision-making and co-operation in employment relations change, and identify the challenges of developing such an approach in the context of the shift towards a more decentralised and market-oriented system of public service delivery. In conclusion we assert that there is a new ‘advisory and benchmarking’ state evolving based on a soft-market view of industrial relations, and that this mitigates (but is also in tension with) the harder market view within the state concerned with transforming the public sector

    Very Massive Stars in High-Redshift Galaxies

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    A significant fraction of Lyman Alpha (Lya) emitting galaxies (LAEs) at z> 5.7 have rest-frame equivalent widths (EW) greater than ~100 Angstrom. However only a small fraction of the Lya flux produced by a galaxy is transmitted through the IGM, which implies intrinsic Lya EWs that are in excess of the maximum allowed for a population-II stellar population having a Salpeter mass function. In this paper we study characteristics of the sources powering Lya emission in high redshift galaxies. We propose a simple model for Lya emitters in which galaxies undergo a burst of very massive star formation that results in a large intrinsic EW, followed by a phase of population-II star formation with a lower EW. We confront this model with a range of high redshift observations and find that the model is able to simultaneously describe the following eight properties of the high redshift galaxy population with plausible values for parameters like the efficiency and duration of star formation: i-iv) the UV and Lya luminosity functions of LAEs at z=5.7 and 6.5, v-vi) the mean and variance of the EW distribution of Lya selected galaxies at z=5.7, vii) the EW distribution of i-drop galaxies at z~6, and viii) the observed correlation of stellar age with EW. Our modeling suggests that the observed anomalously large intrinsic equivalent widths require a burst of very massive star formation lasting no more than a few to ten percent of the galaxies star forming lifetime. This very massive star formation may indicate the presence of population-III star formation in a few per cent of i-drop galaxies, and in about half of the Lya selected galaxies.Comment: 11 pages, 7 figures, MNRAS in press, comments by referee included, references added+update

    Achieving Accountable Care: Are We on the Right Path?

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    Based on the Commonwealth Fund Commission on a High Performance Health System's ten recommendations, highlights considerations for the Centers for Medicare and Medicaid Services in finalizing rules for the Shared Savings Program, slated to begin in 2012
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