13,507 research outputs found

    ‘Outside the original remit’: co-production in UK mental health research, lessons from the field

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    The aim of this discursive paper was to explore the development of co-productio nand service user involvement in UK university-based mental health research and to offer practicalrecommendations for practitioners co-producing research with service users and survivors,informed by an overview of the key literature on co-production in mental health and from acritical reflection on applied research throu gh the medium of a case study. The paper is co-writtenby a mental health nurse academic and a service user/survivor researcher academic. The authorsargue that the implications of co-production for mental health research remain underexplored, butthat both the practitioner and service user/survivor resea rcher experience and perspective of co-production in research can provide practical reflections to inform developing research practice.The theories and values of emancipatory research can provide a framework from which bothpractitioners and service users can work together on a research project, in a way that requiresreflection on process and power dynamics. The authors conclude that whilst co-producedinvestigations can offer unique opportunities for advancing emancipatory and applied research inmental health, practitioner researchers need to be more radical in their consid eration of power inthe research process. [Abstract copyright: © 2018 Australian College of Mental Health Nurses Inc.

    Fractional charge excitations in fermionic ladders

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    The system of interacting spinless fermions hopping on a two-leg ladder in the presence of an external magnetic field is shown to possess a long range order: the bond density wave or the staggered flux phase. In both cases the elementary excitations are Z2Z_2 kinks and carry one half the charge of an electron.Comment: 4 pages, 3 figure

    On Markovian solutions to Markov Chain BSDEs

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    We study (backward) stochastic differential equations with noise coming from a finite state Markov chain. We show that, for the solutions of these equations to be `Markovian', in the sense that they are deterministic functions of the state of the underlying chain, the integrand must be of a specific form. This allows us to connect these equations to coupled systems of ODEs, and hence to give fast numerical methods for the evaluation of Markov-Chain BSDEs

    Growth of primordial black holes in a universe containing a massless scalar field

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    The evolution of primordial black holes in a flat Friedmann universe with a massless scalar field is investigated in fully general relativistic numerical relativity. A primordial black hole is expected to form with a scale comparable to the cosmological apparent horizon, in which case it may go through an initial phase with significant accretion. However, if it is very close to the cosmological apparent horizon size, the accretion is suppressed due to general relativistic effects. In any case, it soon gets smaller than the cosmological horizon and thereafter it can be approximated as an isolated vacuum solution with decaying mass accretion. In this situation the dynamical and inhomogeneous scalar field is typically equivalent to a perfect fluid with a stiff equation of state p=ρp=\rho. The black hole mass never increases by more than a factor of two, despite recent claims that primordial black holes might grow substantially through accreting quintessence. It is found that the gravitational memory scenario, proposed for primordial black holes in Brans-Dicke and scalar-tensor theories of gravity, is highly unphysical.Comment: 24 pages, accepted for publication in Physical Review

    Direct observation of the proliferation of ferroelectric loop domains and vortex-antivortex pairs

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    We discovered "stripe" patterns of trimerization-ferroelectric domains in hexagonal REMnO3 (RE=Ho, ---, Lu) crystals (grown below ferroelectric transition temperatures (Tc), reaching up to 1435 oC), in contrast with the vortex patterns in YMnO3. These stripe patterns roughen with the appearance of numerous loop domains through thermal annealing just below Tc, but the stripe domain patterns turn to vortex-antivortex domain patterns through a freezing process when crystals cross Tc even though the phase transition appears not to be Kosterlitz-Thouless-type. The experimental systematics are compared with the results of our six-state clock model simulation and also the Kibble-Zurek Mechanism for trapped topological defects

    The Hyperfine Molecular Hubbard Hamiltonian

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    An ultracold gas of heteronuclear alkali dimer molecules with hyperfine structure loaded into a one-dimensional optical lattice is investigated. The \emph{Hyperfine Molecular Hubbard Hamiltonian} (HMHH), an effective low-energy lattice Hamiltonian, is derived from first principles. The large permanent electric dipole moment of these molecules gives rise to long range dipole-dipole forces in a DC electric field and allows for transitions between rotational states in an AC microwave field. Additionally, a strong magnetic field can be used to control the hyperfine degrees of freedom independently of the rotational degrees of freedom. By tuning the angle between the DC electric and magnetic fields and the strength of the AC field it is possible to control the number of internal states involved in the dynamics as well as the degree of correlation between the spatial and internal degrees of freedom. The HMHH's unique features have direct experimental consequences such as quantum dephasing, tunable complexity, and the dependence of the phase diagram on the molecular state

    The development and validation of a teacher-reported low-level classroom disruption scale (LLCD-S)

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    Low-level classroom disruption (LLCD) is characterised by pupils swinging on chairs, whispering or fidgeting in class. This paper provides initial data on the development and validation of the teacher-rated Low-Level Classroom Disruption Scale (LLCD-S), with two samples of primary school pupils. Exploratory factor analysis in Study 1 (N= 120) revealed one factor accounting for 61% of the variance; supported by confirmatory factor analysis in Study 2 (N= 274), with one factor accounting for 63% of the variance. Both studies reported high Cronbach’s alpha values of.82 and.93 respectively. The evidence supports LLCD being a unidimensional construct, measured by the eight item LLCD-S. Weak convergence validity was found between the LLCD-S and the Strengths and Difficulties Questionnaire’s (SDQ) externalising behaviours: conduct problems and hyperactivity. This preliminary evidence indicates that LLCD-S is a valid and reliable measure of low-level classroom disruption. Further research is needed to test the utility of the LLCD-S across different levels of education, cultures and as a pupil-reported measure

    Accretion with back reaction

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    We calculate analytically a back reaction of the stationary spherical accretion flow near the event horizon and near the inner Cauchy horizon of the charged black hole. It is shown that corresponding back-reaction corrections to the black hole metric depend only on the fluid accretion rate and diverge in the case of an extremely charged black hole. In result, the test fluid approximation for stationary accretion is violated for extreme black holes. This behavior of the accreting black hole is in accordance with the third law of black hole thermodynamics, forbidding the practical attainability of the extreme state.Comment: 5 pages, 2 figures; new figure and references adde
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