1,498 research outputs found

    Axisymmetric equilibria of a gravitating plasma with incompressible flows

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    It is found that the ideal magnetohydrodynamic equilibrium of an axisymmetric gravitating magnetically confined plasma with incompressible flows is governed by a second-order elliptic differential equation for the poloidal magnetic flux function containing five flux functions coupled with a Poisson equation for the gravitation potential, and an algebraic relation for the pressure. This set of equations is amenable to analytic solutions. As an application, the magnetic-dipole static axisymmetric equilibria with vanishing poloidal plasma currents derived recently by Krasheninnikov, Catto, and Hazeltine [Phys. Rev. Lett. {\bf 82}, 2689 (1999)] are extended to plasmas with finite poloidal currents, subject to gravitating forces from a massive body (a star or black hole) and inertial forces due to incompressible sheared flows. Explicit solutions are obtained in two regimes: (a) in the low-energy regime β0≈γ0≈δ0≈ϵ0≪1\beta_0\approx \gamma_0\approx \delta_0 \approx\epsilon_0\ll 1, where β0\beta_0, γ0\gamma_0, δ0\delta_0, and ϵ0\epsilon_0 are related to the thermal, poloidal-current, flow and gravitating energies normalized to the poloidal-magnetic-field energy, respectively, and (b) in the high-energy regime β0≈γ0≈δ0≈ϵ0≫1\beta_0\approx \gamma_0\approx \delta_0 \approx\epsilon_0\gg 1. It turns out that in the high-energy regime all four forces, pressure-gradient, toroidal-magnetic-field, inertial, and gravitating contribute equally to the formation of magnetic surfaces very extended and localized about the symmetry plane such that the resulting equilibria resemble the accretion disks in astrophysics.Comment: 12 pages, latex, to be published in Geophys. Astrophys. Fluid Dynamic

    Reputation in European Trade Mark Law: A Re-examination

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    Under the harmonised European trade mark regime marks with a reputation enjoy expanded protection. This article casts doubt on whether this ‘reputational trigger’ can be justified. It then explores some difficult operational questions about the way the reputation threshold works in cases where the mark enjoys fame only in niche markets or in a limited geographical area, the aim being to illustrate further why reputation is an unsatisfactory trigger for a different type of trade mark protection. Finally, it looks at some of the evidential difficulties involved in adjudicating disputes in which expanded protection is being claimed. It concludes by suggesting that if the evidential problems we identify were tackled the reputation threshold could be abandoned

    Submission in Response to the Australian Productivity Commission's Inquiry into IP Arrangements Draft Report

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    This Submission by nine intellectual property academics responds to the Draft Report in the Inquiry into IP Arrangements published by the Australian Productivity Commission on 29 April 2016 ('Draft Report'). In broad terms, the submission supports many of the goals of, and recommendations of, the Productivity Commission expressed in the Draft Report, but expresses concerns that some recommendations may not achieve the overall goals of the Commission, or reflect misunderstandings of the statutory framework. The submission addresses many of the Commission's draft recommendations concerning copyright, patents, trade marks and geographical indicators, IP and public institutions, and IP's institutional and governance arrangements

    Descripción del transporte y conservación de las vacunas de adquisición particular

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    Objetivo: Describir el transporte y conservación de las vacunas adquiridas de manera particular. Método: Estudio observacional descriptivo y transversal. Se estudiaron todas las dosis de vacunas antineumocócica conjugada, antirrotavirus y antivaricelosa adquiridas particularmente y administradas entre enero y septiembre de 2009 en un Centro de Atención Primaria de Salud (CAP) de ámbito urbano. Variables estudiadas: tipo de vacuna, circuito utilizado (circuito A: farmacia-CAP; circuito B: farmacia-casa-CAP), tiempo entre adquisición y administración, recepción de información, medio de transporte y conservación en domicilio. Recogida de datos por cuestionario. Estrategia estadística: frecuencias absolutas y relativas, X2 de Pearson y estadístico exacto de Fisher. Resultados: Muestra total de 148 dosis: 115 (77,7%) antineumocócica, 28 (18,9%) antirrotavirus y 5 (3,4%) antivaricelosa. El 45,5% (67) de las dosis administradas han seguido el circuito A y el 54,7% (81), el B. El 89,6% (60) de las vacunas del circuito A tardaron menos de 1 h entre la compra y la administración, y el 14,8% (12) del B tardaron más de 7 días. El 85,1% (111) de los padres recibieron información sobre transporte y conservación de la vacuna. El 85,1% (57) de las vacunas del circuito A y el 93,8% (76) del B no utilizaron frío en el medio de transporte. El 59,3% (48) de las vacunas se conservaron en la puerta de la nevera. Conclusiones: La vacuna antineumocócica es la más administrada. El circuito más utilizado es el B. La mayoría de los padres recibieron información sobre el transporte y la conservación de las vacunas, aunque transportaron más de la mitad en medio no frío y las conservaron en la puerta de la nevera

    Entanglement and correlation functions following a local quench: a conformal field theory approach

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    We show that the dynamics resulting from preparing a one-dimensional quantum system in the ground state of two decoupled parts, then joined together and left to evolve unitarily with a translational invariant Hamiltonian (a local quench), can be described by means of quantum field theory. In the case when the corresponding theory is conformal, we study the evolution of the entanglement entropy for different bi-partitions of the line. We also consider the behavior of one- and two-point correlation functions. All our findings may be explained in terms of a picture, that we believe to be valid more generally, whereby quasiparticles emitted from the joining point at the initial time propagate semiclassically through the system.Comment: 19 pages, 4 figures, v2 typos corrected and refs adde

    Towards practice-based studies of HRM: an actor-network and communities of practice informed approach

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    HRM may have become co-terminus with the new managerialism in the rhetorical orthodoxies of the HRM textbooks and other platforms for its professional claims. However, we have detailed case-study data showing that HR practices can be much more complicated, nuanced and indeed resistive toward management within organizational settings. Our study is based on ethnographic research, informed by actor-network theory and community of practice theory conducted by one of the authors over an 18-month period. Using actor-network theory in a descriptive and critical way, we analyse practices of managerial resistance, enrolment and counter-enrolment through which an unofficial network of managers used a formal HRM practice to successfully counteract the official strategy of the firm, which was to close parts of a production site. As a consequence, this network of middle managers effectively changed top management strategy and did so through official HRM practices, coupled with other actor-network building processes, arguably for the ultimate benefit of the organization, though against the initial views of the top management. The research reported here, may be characterized as a situated study of HRM-in-practice and we draw conclusions which problematize the concept of HRM in contemporary management literature

    Zonal flows and long-distance correlations during the formation of the edge shear layer in the TJ-II stellarator

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    A theoretical interpretation is given for the observed long-distance correlations in potential fluctuations in TJ-II. The value of the correlation increases above the critical point of the transition for the emergence of the plasma edge shear flow layer. Mean (i.e. surface averaged, zero-frequency) sheared flows cannot account for the experimental results. A model consisting of four envelope equations for the fluctuation level, the mean flow shear, the zonal flow amplitude shear, and the averaged pressure gradient is proposed. It is shown that the presence of zonal flows is essential to reproduce the main features of the experimental observations.Comment: 19 pages, 7 figure

    Habitat geometry rather than visual acuity limits the visibility of a ground-nesting bird's clutch to terrestrial predators

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    This is the final version. Available on open access from Wiley via the DOI in this record. Data availability statement: The dryad doi: https://datadryad.org/stash/share/2yJJ6xuGiKF7Ey6H2y1rAwyqJVGYFdBgFisTb4NN34I. All data and plots for the main text and supplementary material can be found within our dryad archive. ImageJ scripts for running RNL and 3D analyses with the MICA toolbox and ImageJ can be downloaded from our GitHub: https://github.com/GeorgeHancock471/3D_RNL_Tools.The nests of ground-nesting birds rely heavily on camouflage for their survival, and predation risk, often linked to ecological changes from human activity, is a major source of mortality. Numerous ground-nesting bird populations are in decline, so understanding the effects of camouflage on their nesting behavior is relevant to their conservation concerns. Habitat three-dimensional (3D) geometry, together with predator visual abilities, viewing distance, and viewing angle, determine whether a nest is either visible, occluded, or too far away to detect. While this link is intuitive, few studies have investigated how fine-scale geometry is likely to help defend nests from different predator guilds. We quantified nest visibility based on 3D occlusion, camouflage, and predator visual modeling in northern lapwings, Vanellus vanellus, on different land management regimes. Lapwings selected local backgrounds that had a higher 3D complexity at a spatial scale greater than their entire clutches compared to local control sites. Importantly, our findings show that habitat geometry-rather than predator visual acuity-restricts nest visibility for terrestrial predators and that their field habitats, perceived by humans as open, are functionally closed with respect to a terrestrial predator searching for nests on the ground. Taken together with lapwings' careful nest site selection, our findings highlight the importance of considering habitat geometry for understanding the evolutionary ecology and management of conservation sites for ground-nesting birds.Natural Environment Research Council (NERC)Game and Wildlife Conservation Trus

    Convergence calls: multimedia storytelling at British news websites

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    This article uses qualitative interviews with senior editors and managers from a selection of the UK's national online news providers to describe and analyse their current experimentation with multimedia and video storytelling. The results show that, in a period of declining newspaper readership and TV news viewing, editors are keen to embrace new technologies, which are seen as being part of the future of news. At the same time, text is still reported to be the cornerstone for news websites, leading to changes in the grammar and function of news video when used online. The economic rationale for convergence is examined and the article investigates the partnerships sites have entered into in order to be able to serve their audience with video content. In-house video is complementing syndicated content, and the authors examine the resulting developments in newsroom training and recruitment practices. The article provides journalism and interactive media scholars with case studies on the changes taking place in newsrooms as a result of the shift towards multimedia, multiplatform news consumption
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