441 research outputs found

    For a Graduating Class 1940

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    Barriers and enablers to conducting health promotion in private dental practice

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    Theme: This study 'connects the dots' by using research to inform contemporary health promotion practice in the dentistry field. The findings acknowledge the importance of dentists re-orientating their practice to take more of a preventative approach to addressing oral health issues. The study explores barriers and enablers to conducting health promotion strategies and suggests recommendations to addressing these barriers. This study 'matters' due to the large oral health burden in Australia and the important role dentists play in helping to address this issue. What is the aim of your project or research? This research reports on findings from a qualitative research project exploring the perceptions of private practice dentists towards implementing health promotion strategies in their practice. This study was conducted in Cairns, Queensland. Challenges of issue or topic of concern Poor oral health is a significant public health concern in Australia. Dentists play an important role, however their role traditionally focuses on curative/restorative treatment rather than health promotion, particularly primary prevention. What did you do? Semi-structured, face-to-face interviews with private practice dentists in Cairns, Australia. Questions were based on broad themes to explore dentists experience, perceived barriers and enablers to conducting health promotion. What were the outcomes? Dentists had diverse views and experiences of incorporating health promotion in their practice. Lack of funds and time were perceived to be key barriers whereas owning a practice, appropriate skills, capacity and proactive auxiliary staff were key enablers for health promotion to occur. Why does it matter? Poor oral health can have a significant impact on a person's quality of life. Oral diseases can be prevented through a range of health promotion strategies. This research makes a difference to the community as it engages dentists in identifying opportunities to overcome some of the barriers to conducting health promotion in their practice. These opportunities can be advocated for at a policy level, and can also considered at a university curriculum level to optimise the training and skills dentists require to conduct effective health promotion in their practice

    Evidence of a Curved Synchrotron Spectrum in the Supernova Remnant SN 1006

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    A joint spectral analysis of some Chandra ACIS X-ray data and Molonglo Observatory Synthesis Telescope radio data was performed for 13 small regions along the bright northeastern rim of the supernova remnant SN 1006. These data were fitted with a synchrotron radiation model. The nonthermal electron spectrum used to compute the photon emission spectra is the traditional exponentially cut off power law, with one notable difference: The power-law index is not a constant. It is a linear function of the logarithm of the momentum. This functional form enables us to show, for the first time, that the synchrotron spectrum of SN 1006 seems to flatten with increasing energy. The effective power-law index of the electron spectrum is 2.2 at 1 GeV (i.e., radio synchrotron-emitting momenta) and 2.0 at about 10 TeV (i.e., X-ray synchrotron-emitting momenta). This amount of change in the index is qualitatively consistent with theoretical models of the amount of curvature in the proton spectrum of the remnant. The evidence of spectral curvature implies that cosmic rays are dynamically important instead of being "test" particles. The spectral analysis also provides a means of determining the critical frequency of the synchrotron spectrum associated with the highest-energy electrons. The critical frequency seems to vary along the northeastern rim, with a maximum value of 1.1e17 (0.6e17 - 2.1e17) Hz. This value implies that the electron diffusion coefficient can be no larger than a factor of ~4.5-21 times the Bohm diffusion coefficient if the velocity of the forward shock is in the range 2300-5000 km/s. Since the coefficient is close to the Bohm limit, electrons are accelerated nearly as fast as possible in the regions where the critical frequency is about 1.0e17 Hz.Comment: 41 pages, 8 figures, accepted by Ap

    An efficient shooting algorithm for Evans function calculations in large systems

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    In Evans function computations of the spectra of asymptotically constant-coefficient linear operators, a basic issue is the efficient and numerically stable computation of subspaces evolving according to the associated eigenvalue ODE. For small systems, a fast, shooting algorithm may be obtained by representing subspaces as single exterior products \cite{AS,Br.1,Br.2,BrZ,BDG}. For large systems, however, the dimension of the exterior-product space quickly becomes prohibitive, growing as (nk)\binom{n}{k}, where nn is the dimension of the system written as a first-order ODE and kk (typically ∌n/2\sim n/2) is the dimension of the subspace. We resolve this difficulty by the introduction of a simple polar coordinate algorithm representing ``pure'' (monomial) products as scalar multiples of orthonormal bases, for which the angular equation is a numerically optimized version of the continuous orthogonalization method of Drury--Davey \cite{Da,Dr} and the radial equation is evaluable by quadrature. Notably, the polar-coordinate method preserves the important property of analyticity with respect to parameters.Comment: 21 pp., two figure

    Environmental Effects in Clusters: Modified Far-Infrared--Radio Relations within Virgo Cluster Galaxies

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    (abridged) We present a study on the effects of the intracluster medium (ICM) on the interstellar medium (ISM) of 10 Virgo cluster spiral galaxies using {\it Spitzer} far-infrared (FIR) and VLA radio continuum imaging. Relying on the FIR-radio correlation within normal galaxies, we use our infrared data to create model radio maps which we compare to the observed radio images. For 6 of our sample galaxies we find regions along their outer edges that are highly deficient in the radio compared with our models. We believe these observations are the signatures of ICM ram pressure. For NGC 4522 we find the radio deficit region to lie just exterior to a region of high radio polarization and flat radio spectral index, although the total 20 cm radio continuum in this region does not appear strongly enhanced. These characteristics seem consistent for other galaxies with radio polarization data in the literature. The strength of the radio deficit is inversely correlated with the time since peak pressure as inferred from stellar population studies and gas stripping simulations, suggesting the strength of the radio deficit is good indicator of the strength of the current ram pressure. We also find that galaxies having {\it local} radio {\it deficits} appear to have {\it enhanced global} radio fluxes. Our preferred physical picture is that the observed radio deficit regions arise from the ICM wind sweeping away cosmic-ray (CR) electrons and the associated magnetic field, thereby creating synchrotron tails as observed for some of our galaxies. We propose that CR particles are also re-accelerated by ICM-driven shocklets behind the observed radio deficit regions which in turn enhances the remaining radio disk brightness.Comment: 19 pages, 10 figures; Astrophysical Journa

    “I'm a Referee, Not a Female Referee”: The Experiences of Women Involved in Football as Coaches and Referees

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    The development of the Women's Super League (WSL) in English football, increased media coverage of the game, and an expansion of grassroots opportunities indicate a bright future for women and girls who want to play. Yet this vision must be tempered against compelling evidence of deep rooted and enduring gender inequalities within the game. This is the case for both players, and women who undertake non-playing roles, which is reflected in the relatively low numbers of women coaches and referees. Whilst The Football Association (The FA) has signalled addressing these inequalities as a key priority, critics argue that such efforts amount to superficial and limited efforts to support meaningful change. This paper departs from a concern with playing the game and responds to calls for more research to explore the experiences of women involved in football in non-playing roles. More specifically, it focuses on women coaches and referees, and addresses the following question: how do women in positions of power in football negotiate their place in what remains a distinctly male-dominated profession? In addressing this question, we take a theoretical position located at the nexus between radical and post-structural feminism, acknowledging the significance of structural power relations and individual agency in shaping daily lived social realities. Data were generated from interviews with 14 women coaches and 10 women referees. These interviews explored the structure and culture of the game and its impact on women's experiences of men's and women's competitive and grassroots football. Through a rigorous process of thematic analysis, three themes were identified: gendered entry into football careers; reinforcement of women's difference on the football field; and coping strategies for remaining in the game. Centralising the women's voices in this research highlights the insidious and persistent nature of gendered microaggressions, the sexism of football culture, and the ways in which these women negotiate this masculine terrain in their pursuit of being coaches and referees. “Andy Gray and Richard Keys hauled off air for sexist comments” (The Guardian, 24 January, 2011) “Crystal Palace Women goalkeeper accuses clubs of ignoring FA protocols after she was subjected to sexist abuse” (The Telegraph, 16 January, 2020) “Football manager demands ban on women referees” (The Guardian, 12 November, 2006) “Richard Scudamore sexism scandal intensifies as conspirator in sexist emails investigated by own law firm” (The Telegraph, 16 May, 2014) “Soccer chief's plan to boost women's game? Hotpants” (The Guardian, 16 January, 2004) “Women in Football survey a damning indictment of sexism in the workplace” (HRreview, 11 March, 2014) “Clattenburg criticised for claim female referees must pick career or children” (The Telegraph, 1 October, 2021

    Cosmic Ray Protons and Magnetic Fields in Clusters of Galaxies and their Cosmological Consequences

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    The masses of clusters of galaxies estimated by gravitational lensing exceed in many cases the mass estimates based on hydrostatic equilibrium. This may suggest the existence of nonthermal pressure. We ask if radio galaxies can heat and support the cluster gas with injected cosmic ray protons and magnetic field densities, which are permitted by Faraday rotation and gamma ray observations of clusters of galaxies. We conclude that they are powerful enough to do this within a cluster radius of roughly 1 Mpc. If present, nonthermal pressures could lead to a revised estimate of the ratio of baryonic mass to total mass, and the apparent baryonic overdensity in clusters would disappear. In consequence, Ωcold\Omega_{\rm cold}, the clumping part of the cosmological density Ωo\Omega_{o}, would be larger than 0.4 h50−1/20.4\,h_{50}^{-1/2}.Comment: Accepted by ApJ, 16 pages, LaTeX, 2 figures, epsfig.sty, aaspp4.st

    Rayleigh-Taylor Instabilities in Type Ia Supernova Remnants undergoing Cosmic-Ray Particle Acceleration - Low Adiabatic Index Solutions

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    This study investigates the evolution of Rayleigh-Taylor (R-T) instabilities in Type Ia supernova remnants that are associated with a low adiabatic index gamma, where gamma < 5/3, which reflects the expected change in the supernova shock structure as a result of cosmic-ray particle acceleration. Extreme cases, such as the case with the maximum compression ratio that corresponds to gamma=1.1, are examined. As gamma decreases, the shock compression ratio rises, and an increasingly narrow inter shock region with a more pronounced initial mixture of R-T unstable gas is produced. Consequently, the remnant outline may be perturbed by small-amplitude, small-wavelength bumps. However, as the instability decays over time, the extent of convective mixing in terms of the ratio of the radius of the R-T fingers to the blast wave does not strongly depend on the value of gamma for gamma >= 1.2. As a result of the age of the remnant, the unstable gas cannot extend sufficiently far to form metal-enriched filaments of ejecta material close to the periphery of Tycho's supernova remnant. The consistency of the dynamic properties of Tycho's remnant with the adiabatic model gamma=5/3 reveals that the injection of cosmic rays is too weak to alter the shock structure. Even with very efficient acceleration of cosmic rays at the shock, significantly enhanced mixing is not expected in Type Ia supernova remnants.Comment: 11 pages, 10 figures, MNRAS, accepte

    In-the-loop or on-the-loop? Interactional arrangements to support team coordination with a planning agent

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    In this paper we present the study of interactional arrangements that support the collaboration of headquarters (HQ), field responders and a computational planning agent in a time-critical task setting created by a mixed-reality game. Interactional arrangements define the extent to which control is distributed between the collaborative parties.We provide two field trials, one to study an “on-the-loop” arrangement in which HQ monitors and intervenes in agent instructions to field players on demand, and the other to study a version that places headquarters more tightly “in-the-loop”. The studies provide and understanding of the sociotechnical collaboration between players and the agent in these interactional arrangements, by conducting interaction analysis of video recordings and game log data. The first field trial focuses on the collaboration of field responders with the planning agent. Findings highlight how players negotiate the agent guidance within the social interaction of the collocated teams. The second field trial focuses on the collaboration between the automated planning agent and the headquarters. We find that the human coordinator and the agent can successfully work together in most cases, with human coordinators inspecting and ‘correcting’ the agent-proposed plans. Through this field trial-driven development process, we generalise interaction design implications of automated planning agents around the themes of supporting common ground and mixed-initiative planning

    Nonthermal Radiation from Type Ia Supernova Remnants

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    We present calculations of expected continuum emissions from Sedov-Taylor phase Type Ia supernova remnants (SNRs), using the energy spectra of cosmic ray (CR) electrons and protons from nonlinear diffusive shock acceleration (DSA) simulations. A new, general-purpose radiative process code, Cosmicp, was employed to calculate the radiation expected from CR electrons and protons and their secondary products. These radio, X-ray and gamma-ray emissions are generally consistent with current observations of Type Ia SNRs. The emissions from electrons in these models dominate the radio through X-ray bands. Decays of \pi^0 s from p-p collisions mostly dominate the gamma-ray range, although for a hot, low density ISM case (n_{ISM}=0.003 cm^{-3}), the pion decay contribution is reduced sufficiently to reveal the inverse Compton contribution to TeV gamma-rays. In addition, we present simple scalings for the contributing emission processes to allow a crude exploration of model parameter space, enabling these results to be used more broadly. We also discuss the radial surface brightness profiles expected for these model SNRs in the X-ray and gamma-ray bands.Comment: 37 pages, 7 figures, accepted in MNRA
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