3,715 research outputs found

    Manifesto for a European research network into Problematic Usage of the Internet

    Get PDF
    Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.The Internet is now all-pervasive across much of the globe. While it has positive uses (e.g. prompt access to information, rapid news dissemination), many individuals develop Problematic Use of the Internet (PUI), an umbrella term incorporating a range of repetitive impairing behaviours. The Internet can act as a conduit for, and may contribute to, functionally impairing behaviours including excessive and compulsive video gaming, compulsive sexual behaviour, buying, gambling, streaming or social networks use. There is growing public and National health authority concern about the health and societal costs of PUI across the lifespan. Gaming Disorder is being considered for inclusion as a mental disorder in diagnostic classification systems, and was listed in the ICD-11 version released for consideration by Member States (http://www.who.int/classifications/icd/revision/timeline/en/). More research is needed into disorder definitions, validation of clinical tools, prevalence, clinical parameters, brain-based biology, socio-health-economic impact, and empirically validated intervention and policy approaches. Potential cultural differences in the magnitudes and natures of types and patterns of PUI need to be better understood, to inform optimal health policy and service development. To this end, the EU under Horizon 2020 has launched a new four-year European Cooperation in Science and Technology (COST) Action Programme (CA 16207), bringing together scientists and clinicians from across the fields of impulsive, compulsive, and addictive disorders, to advance networked interdisciplinary research into PUI across Europe and beyond, ultimately seeking to inform regulatory policies and clinical practice. This paper describes nine critical and achievable research priorities identified by the Network, needed in order to advance understanding of PUI, with a view towards identifying vulnerable individuals for early intervention. The network shall enable collaborative research networks, shared multinational databases, multicentre studies and joint publications.Peer reviewe

    Short wavelength spectrum and Hamiltonian stability of vortex rings

    Full text link
    We compare dynamical and energetical stability criteria for vortex rings. It is argued that vortex rings will be intrinsically unstable against perturbations with short wavelengths below a critical wavelength, because the canonical vortex Hamiltonian is unbounded from below for these modes. To explicitly demonstrate this behaviour, we derive the oscillation spectrum of vortex rings in incompressible, inviscid fluids, within a geometrical cutoff procedure for the core. The spectrum develops an anomalous branch of negative group velocity, and approaches the zero of energy for wavelengths which are about six times the core diameter. We show the consequences of this dispersion relation for the thermodynamics of vortex rings in superfluid 4^4He at low temperatures.Comment: 7 pages, 4 figures, final version to appear in Phys. Rev.

    QCD Corrections to Scalar Production via Heavy Quark Fusion at Hadron Colliders

    Get PDF
    We recently proposed that, due to the top-quark-mass enhanced Yukawa coupling, the s-channel production of a charged scalar or pseudo-scalar from heavy quark fusion can be an important new mechanism for discovering non-standard spin-0 particles. In this work, we present the complete O(alpha_s) QCD corrections to this s-channel production process at hadron colliders, including the results of QCD resummation over multiple soft-gluon emission. The systematic QCD-improved production and decay rates at the FermiLab Tevatron and the CERN LHC are given for the charged top-pions in the topcolor models and for the charged Higgs bosons in the generic two Higgs doublet model. The direct extension to the production of the neutral (pseudo-)scalars via bb\bar fusion is studied in the minimal supersymmetric standard model (MSSM) with large tan(beta), and in the topcolor model with large bottom Yukawa coupling.Comment: Version to be published in Phys.Rev.D. Discussion on Rb added plus minor improvements. Conclusions not changed. Latex2e, 40 pages, 16 figure

    The heavy top quark in the two Higgs doublet model

    Full text link
    Constraints on the two Higgs doublet model are presented, assuming a top mass of 174 ±\pm 17 GeV. We concentrate primarily on the ``type II'' model, where up--type quarks receive their mass from one Higgs doublet, and down--type quarks receive their mass from the second doublet. High energy constraints derived from the WW mass, the full width of the ZZ and the bbˉb \bar b partial width of the ZZ are combined with low energy constraints from Γ(bsγ)\Gamma(b\to s \gamma), Γ(bcτνˉτ)\Gamma(b \to c \tau \bar\nu_\tau) and B0B^0-Bˉ0\bar B^0 mixing to determine the experimentally favored configurations of the model. This combination of observables rules out small charged Higgs masses and small values of tanβ\tan\beta, and provides some information about the neutral Higgs masses and the mixing angle α\alpha. In particular, constraints derived from the ρ\rho parameter rule out configurations where the charged Higgs is much heavier or much lighter than the neutral Higgses. We discuss a scenario where Γ(Zbbˉ)\Gamma(Z\to b \bar b) is enhanced relative to the standard model result, which unfortunately is on the verge of being ruled out by the combination of Γ(bsγ)\Gamma(b\to s \gamma) and ρ\rho parameter constraints. Implications for various extensions of the standard model are briefly discussed.Comment: 26 page

    Managerial Work in a Practice-Embodying Institution - The role of calling, the virtue of constancy

    Get PDF
    What can be learned from a small scale study of managerial work in a highly marginal and under-researched working community? This paper uses the ‘goods-virtues-practices-institutions’ framework to examine the managerial work of owner-directors of traditional circuses. Inspired by MacIntyre’s arguments for the necessity of a narrative understanding of the virtues, interviews explored how British and Irish circus directors accounted for their working lives. A purposive sample was used to select subjects who had owned and managed traditional touring circuses for at least 15 years, a period in which the economic and reputational fortunes of traditional circuses have suffered badly. This sample enabled the research to examine the self-understanding of people who had, at least on the face of it, exhibited the virtue of constancy. The research contributes to our understanding of the role of the virtues in organizations by presenting evidence of an intimate relationship between the virtue of constancy and a ‘calling’ work orientation. This enhances our understanding of the virtues that are required if management is exercised as a domain-related practice

    Radiative Corrections to the ZbbˉZ b \bar{b} Vertex and Constraints on Extended Higgs Sectors

    Full text link
    We explore the radiative corrections to the process ZbbˉZ \to b \bar b in models with extended Higgs sectors. The observables Rb=Γ(Zbbˉ)/Γ(Zhadrons)R_b = \Gamma(Z \to b \bar b)/\Gamma(Z \to \rm{hadrons}) and the ZbbˉZ b \bar b coupling asymmetry, Ab=(gL2gR2)/(gL2+gR2)A_b = (g_L^2 - g_R^2)/(g_L^2 + g_R^2), are sensitive to these corrections. We present general formulae for the one-loop corrections to RbR_b and AbA_b in an arbitrary extended Higgs sector, and derive explicit results for a number of specific models. We find that in models containing only doublets, singlets, or larger multiplets constrained by a custodial SU(2)cSU(2)_{c} symmetry so that MW=MZcosθWM_W = M_Z \cos\theta_W at tree level, the one-loop corrections due to virtual charged Higgs bosons always worsen agreement with experiment. The RbR_{b} measurement can be used to set lower bounds on the charged Higgs masses. Constraints on models due to the one-loop contributions of neutral Higgs bosons are also examined.Comment: 54 pages, 11 figure

    A Search for WIMPs with the First Five-Tower Data from CDMS

    Get PDF
    We report first results from the Cryogenic Dark Matter Search (CDMS II) experiment running with its full complement of 30 cryogenic particle detectors at the Soudan Underground Laboratory. This report is based on the analysis of data acquired between October 2006 and July 2007 from 15 Ge detectors (3.75 kg), giving an effective exposure of 121.3 kg-d (averaged over recoil energies 10--100 keV, weighted for a weakly interacting massive particle (WIMP) mass of 60 \gev). A blind analysis, incorporating improved techniques for event reconstruction and data quality monitoring, resulted in zero observed events. This analysis sets an upper limit on the WIMP-nucleon spin-independent cross section of 6.6×1044\times10^{-44} cm2^2 (4.6×1044\times10^{-44} cm2^2 when combined with previous CDMS Soudan data) at the 90% confidence level for a WIMP mass of 60 \gev. By providing the best sensitivity for dark matter WIMPs with masses above 42 GeV/c2^2, this work significantly restricts the parameter space for some of the favored supersymmetric models.Comment: 5 pages, 4 figures, submitted to PRL 28 March 200

    The Color of Childhood: The Role of the Child/Human Binary in the Production of Anti-Black Racism

    Get PDF
    The binary between the figure of the child and the fully human being is invoked with regularity in analyses of race, yet its centrality to the conception of race has never been fully explored. For most commentators, the figure of the child operates as a metaphoric or rhetorical trope, a non-essential strategic tool in the perpetuation of White supremacy. As I show in the following, the child/human binary does not present a contingent or merely rhetorical construction but, rather, a central feature of racialization. Where Black peoples are situated as objects of violence it is often precisely because Blackness has been identified with childhood and childhood is historically identified as the archetypal site of naturalized violence and servitude. I proceed by offering a historical account of how Black peoples came to inherit the subordination and dehumanization of European childhood and how White youth were subsequently spared through their partial categorization as adults
    corecore