5,730 research outputs found

    Architects of time: Labouring on digital futures

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    Drawing on critical analyses of the internet inspired by Gilles Deleuze and the Marxist autonomia movement, this paper suggests a way of understanding the impact of the internet and digital culture on identity and social forms through a consideration of the relationship between controls exercised through the internet, new subjectivities constituted through its use and new labour practices enabled by it. Following Castells, we can see that the distinction between user, consumer and producer is becoming blurred and free labour is being provided by users to corporations. The relationship between digital technologies and sense of community, through their relationship to the future, is considered for its dangers and potentials. It is proposed that the internet may be a useful tool for highlighting and enabling social connections if certain dangers can be traversed. Notably, current remedies for the lack of trust on the internet are questioned with an alternative, drawing on Zygmunt Bauman and Georg Simmel, proposed which is built on community through a vision of a ‘shared network’

    A review of UK media coverage of physical activity associated with the publication of special issues in a high-impact medical journal

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    Objectives: The media is a substantial vehicle for conveying public health messages to the public. This study examined the extent to which the publication of special issues in a high-impact medical journal in 2012 and 2016 generated media interest in physical activity and health in the UK and explored the main issues that were reported. Study design: This is a systematic narrative review of print media. Methods: Relevant print news articles were identified by searching Factiva and Google News. The timeframe of each search was 2 weeks, using the publication date of each special issue as the anchor point. Overall, 20 articles were included in the analysis for 2012 and 37 articles for 2016. Results: The news media coverage was encouraging for the profile of physical activity and health. In 2012 and 2016, common themes included the benefits of physical activity and the risks of being inactive, comparisons between mortality rates from physical inactivity and smoking and the recommended volume of physical activity to benefit health. Conclusions: The profile given to an issue through prestigious scientific publication is one of the levers for community attention and policy change. Efforts are needed to further use the media for improving policy, practice and public awareness, which are antecedents to population health change

    Giant Magnetic Moments of Nitrogen Stabilized Mn Clusters and Their Relevance to Ferromagnetism in Mn Doped GaN

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    Using first principles calculations based on density functional theory, we show that the stability and magnetic properties of small Mn clusters can be fundamentally altered by the presence of nitrogen. Not only are their binding energies substantially enhanced, but also the coupling between the magnetic moments at Mn sites remains ferromagnetic irrespective of their size or shape. In addition, these nitrogen stabilized Mn clusters carry giant magnetic moments ranging from 4 Bohr magnetons in MnN to 22 Bohr magnetons in Mn_5N. It is suggested that the giant magnetic moments of Mn_xN clusters may play a key role in the ferromagnetism of Mn doped GaN which exhibit a wide range (10K - 940K) of Curie temperatures

    Advanced Navigation Strategies For Asteroid Sample Return Missions

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    Flyby and rendezvous missions to asteroids have been accomplished using navigation techniques derived from experience gained in planetary exploration. This paper presents analysis of advanced navigation techniques required to meet unique challenges for precision navigation to acquire a sample from an asteroid and return it to Earth. These techniques rely on tracking data types such as spacecraft-based laser ranging and optical landmark tracking in addition to the traditional Earth-based Deep Space Network radio metric tracking. A systematic study of navigation strategy, including the navigation event timeline and reduction in spacecraft-asteroid relative errors, has been performed using simulation and covariance analysis on a representative mission

    Diffusion, Cell Mobility, and Bandlimited Functions

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    The mechanism by which leukocytes steer toward a chemical attractant is not fully resolved. Experimental data suggest that these cells detect differences in concentration of chemoattractant over their surface and walk up the gradient. The problem has been considered theoretically only in stationary media, where the distribution of attractant is determined solely by diffusion. Experimentally, bulk flow has been allowed only unintentionally. Since bulk flow is characteristic of real systems, we examine a simple two-dimensional model incorporating both diffusion and an additional drift. The latter problem leads to an integral equation which is central also in the study of weighted Hilbert spaces of bandlimited functions. We find asymptotic expressions for the required solution by a Wiener-Hopf method adapted to a finite interval. We conclude that, without drift, the concentration does not vary detectably around the cell, but that drift inceases this variation substantially. Thus over model suggests that drift may play an important role in the cell\u27s chemotactic response

    Theoretical He I Emissivities in the Case B Approximation

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    We calculate the He I case B recombination cascade spectrum using improved radiative and collisional data. We present new emissivities over a range of electron temperatures and densities. The differences between our results and the current standard are large enough to have a significant effect not only on the interpretation of observed spectra of a wide variety of objects but also on determinations of the primordial helium abundance.Comment: Accepted to ApJ

    \u3cem\u3eJ\u3c/em\u3e-Resolved He I Emission Predictions in the Low-Density Limit

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    Determinations of the primordial helium abundance are used in precision cosmological tests. These require highly accurate He I recombination rate coefficients. Here we reconsider the formation of He I recombination lines in the low-density limit. This is the simplest case, and it forms the basis for the more complex situation in which collisions are important. The formation of a recombination line is a two-step process, beginning with the capture of a continuum electron into a bound state and followed by radiative cascade to ground. The rate coefficient for capture from the continuum is obtained from photoionization cross sections and detailed balancing, while radiative transition probabilities determine the cascades. We have made every effort to use today\u27s best atomic data. Radiative decay rates are from Drake\u27s variational calculations, which include QED, fine structure, and singlet-triplet mixing. Certain high-L fine-structure levels do not have a singlet-triplet distinction, and the singlets and triplets are free to mix in dipole-allowed radiative decays. We use quantum-defect or hydrogenic approximations to include levels higher than those treated in the variational calculations. Photoionization cross sections come from R-matrix calculations when possible. We use Seaton\u27s method to extrapolate along sequences of transition probabilities to obtain threshold photoionization cross sections for some levels. For higher n we use scaled hydrogenic theory or an extension of quantum-defect theory. We create two independent numerical implementations to ensure that the complex bookkeeping is correct. The two codes use different (reasonable) approximations to span the gap between lower levels, having accurate data, and high levels, where scaled hydrogenic theory is appropriate. We also use different (reasonable) methods to account for recombinations above the highest levels individually considered. We compare these independent predictions to estimate the uncertainties introduced by the various approximations. Singlet-triplet mixing has little effect on the observed spectrum. While intensities of lines within multiplets change, the entire multiplet, the quantity normally observed, does not. The lack of high-precision photoionization cross sections at intermediate n and low L introduces ~0.5% uncertainties in intensities of some lines. The high-n unmodeled levels introduce ~1% uncertainties for “yrast\u27\u27 lines, defined as those having L=n-1 upper levels. This last uncertainty will not be present in actual nebulae, since such high levels are held in statistical equilibrium by collisional processes. We identify those lines that are least affected by uncertainties in the atomic physics and so should be used in precision helium abundance determinations

    NSW Get Healthy Information and Coaching Services The First Five Years 2009-2013

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    The 'NSW Get Healthy Information and Coaching Service: The First Five Years 2009 - 2013' evaluation report was published in June 2014. The report showcases the effectiveness, reach, and health impact of the Service since it's inception in 2009

    NSW Get Healthy Information and Coaching Services The First Five Years 2009-2013

    Get PDF
    The 'NSW Get Healthy Information and Coaching Service: The First Five Years 2009 - 2013' evaluation report was published in June 2014. The report showcases the effectiveness, reach, and health impact of the Service since it's inception in 2009

    ‘20 tins of Stella for a fiver’: The making of class through Labour and Coalition government alcohol policy

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    Alcohol use in the UK has been a key concern to both the Labour and Coalition governments, and commands considerable attention in the media and academic discussions. This article analyses how recent government policy discussions have defined particular forms of drinking as problematic, and how these definitions and associated policy initiatives can be seen as part of a wider symbolic economy through which people come to be valued differently, incorporating ideas of economic, cultural and social capital. Therefore, I argue that government policies and discussions of drinking are a key way in which class is constituted in contemporary Britain
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