44 research outputs found

    Mental health nurses’ support to caregivers of older adults with severe mental illness : a qualitative study

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    Background: Literature has shown the serious impact of severe mental illness on the daily life of caregivers. We studied reported caregiver support practices by mental health nurses for use in the development of a nursing intervention. We aimed to explore current caregiver support practices by mental health nurses. Methods: Twenty-one participants completed semi-structured interviews, and 17 participants attended two focus groups. All interviews were audio-taped, transcribed and coded for qualitative analysis. Results: The diversity in caregiver support could best be described by three prototypes: the tolerator, the preventer and the concerner, representing three approaches of involvement with caregivers. At one end of the spectrum are mental health nurses (MHN) who are essentially only concerned with the wellbeing of the care recipient and see the caregiver as a potential impediment in reaching the client’s goals. We call these the tolerators. At the other end of the spectrum are the MHNs who see the caregiver and the care recipient as inextricably connected with each other. In these cases the MHN directs her/his intervention towards both the informal caregiver and the care recipient. We call these the concerners. In the middle position are MHNs who realize that caregivers are important agents in the achievement of the client’s goals, and therefore consider preventing them from becoming overburdened as an important goal. We call these the preventers. Conclusions: Based on the extent to which the MHNs believe that the informal caregiver plays a necessary role in the client’s support system, and the degree to which they feel responsible for the caregiver’s wellbeing, three MHN prototypes can be distinguished. These prototypes determine how the nurses’ vision directs their understanding of their role and responsibilities and the content of their behaviour. This implies that a change in behaviour needs to be preceded by a change in vision. Therefore, promoting family support cannot be achieved by one-size-fits-all-programmes

    Richard Chapman (1943-2020)

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    Nonstandard optics from quantum spacetime

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    We study light propagation in the picture of semi-classical space-time that emerges in canonical quantum gravity in the loop representation. In such picture, where space-time exhibits a polymer-like structure at microscales, it is natural to expect departures from the perfect non-dispersiveness of ordinary vacuum. We evaluate these departures, computing the modifications to Maxwell's equations due to quantum gravity, and showing that under certain circumstances, non-vanishing corrections appear that depend on the helicity of propagating waves. These effects could lead to observable cosmological predictions of the discrete nature of quantum spacetime. In particular, recent observations of non-dispersiveness in the spectra of gamma-ray bursts at various energies could be used to constrain the type of semi-classical state that describes the universe.Comment: 4 pages, RevTeX, no figure

    Body cooling and its energetic implications for feeding and diving of tufted ducks

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    Wintering in a temperate climate with low water temperatures is energetically expensive for diving ducks. The energy costs associated with body cooling due to diving and ingesting large amounts of cold food were measured in tufted ducks (Aythya fuligula) feeding on zebra mussels (Dreissena polymorpha), using implanted heart rate and body temperature transmitters. The effects of diving depth and food ingestion were measured in two sets of experiments: we measured body cooling and energy costs of six tufted ducks diving to different depths in a 6-m-deep indoor tank; the costs for food ingestion and crushing mussel shells were assessed under seminatural winter conditions with the same ducks feeding on mussels in a 1.5-m-deep outdoor pond. Body temperature dropped during feeding bouts and increased gradually during intermittent resting periods. The temperature drop increased linearly with dive duration. The rate of body cooling increased with feeding depth, but it was lower again at depths below 4 m. Half of the increment in energy costs of diving can be attributed to thermoregulatory heat production, of which approximately 50% is generated after diving to warm up the body. The excess costs for ducks feeding on large-sized mussels could be entirely explained by the estimated energy cost necessary to compensate the heat loss following food ingestion, suggesting that the heat production from shell crushing substituted for thermoregulation. Recovery from heat loss is probably a major component of the activity budget of wintering diving ducks

    The graviton vacuum as a distributional state in kinematic Loop Quantum Gravity

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    The quantum behaviour of weak gravitational fields admits an adequate, albeit approximate, description by those graviton states in which the expectation values and fluctuations of the linearised gravitational field are small. Such states must approximate corresponding states in full quantum gravity. We analyse the nature of this approximation for the graviton vacuum state in the context of kinematical Loop Quantum Gravity (LQG) wherein the constraints are ignored. We identify the graviton vacuum state with kinematically non-normalizable, distributional states in LQG by demanding that relations between linearised operator actions on the former are mirrored by those of their non-linear counterparts on the latter. We define a semi- norm on the space of kinematical distributions and show that the identification is approximate upto distributions which are small in this semi-norm. We argue that our candidate states are annihilated by the linearised constraints (expressed as operators in the full theory) to leading order in the parameter characterising the approximation. This suggests the possibility, in a scheme such as ours, of solving the full constraints order by order in this parameter. The main drawback of our considerations is that they depend on certain auxilliary constructions which, though mathematically well defined, do not arise from physical insight. Our work is an attempt to implement an earlier proposal of Iwasaki and Rovelli.Comment: 44 pages, no figure

    Quantum gravity corrections to neutrino propagation

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    Massive spin-1/2 fields are studied in the framework of loop quantum gravity by considering a state approximating, at a length scale L\cal L much greater than Planck length P=1.2×1033\ell_P=1.2\times 10^{-33}cm, a spin-1/2 field in flat spacetime. The discrete structure of spacetime at P\ell_P yields corrections to the field propagation at scale L\cal L. Next, Neutrino Bursts (pˉ105{\bar p}\approx 10^5GeV) accompaning Gamma Ray Bursts that have travelled cosmological distances, L1010L\approx 10^{10}l.y., are considered. The dominant correction is helicity independent and leads to a time delay w.r.t. the speed of light, cc, of order (pˉP)L/c104({\bar p} \ell_P) L/c\approx 10^4s. To next order in pˉP{\bar p} \ell_P the correction has the form of the Gambini and Pullin effect for photons. Its contribution to time delay is comparable to that caused by the mass term. Finally, a dependence Los1pˉ2PL_{\rm os}^{-1} \propto {\bar p}^2 \ell_P is found for a two-flavour neutrino oscillation length.Comment: RevTeX, 5pp, no figures. Notation of a sum in Eq.(2) improved. Slight modifications in redaction. Final version to appear in Phys. Rev. Let

    Loop Representations

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    The loop representation plays an important role in canonical quantum gravity because loop variables allow a natural treatment of the constraints. In these lectures we give an elementary introduction to (i) the relevant history of loops in knot theory and gauge theory, (ii) the loop representation of Maxwell theory, and (iii) the loop representation of canonical quantum gravity. (Based on lectures given at the 117. Heraeus Seminar, Bad Honnef, Sept. 1993)Comment: 38 pages, MPI-Ph/93-9

    Loop quantum gravity and light propagation

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    Within loop quantum gravity we construct a coarse-grained approximation for the Einstein-Maxwell theory that yields effective Maxwell equations in flat spacetime comprising Planck scale corrections. The corresponding Hamiltonian is defined as the expectation value of the electromagnetic term in the Einstein-Maxwell Hamiltonian constraint, regularized a la Thiemann, with respect to a would-be semiclassical state. The resulting energy dispersion relations entail Planck scale corrections to those in flat spacetime. Both the helicity dependent contribution of Gambini and Pullin [GP] and, for a value of a parameter of our approximation, that of Ellis et. al. [ELLISETAL] are recovered. The electric/magnetic asymmetry in the regularization procedure yields nonlinearities only in the magnetic sector which are briefly discussed. Observations of cosmological Gamma Ray Bursts might eventually lead to the needed accuracy to study some of these quantum gravity effects.Comment: Latex, 45 pages, shorter abstract, additional reference

    Factor structure and construct validity of the Adult Social Care Outcomes Toolkit for Carers (ASCOT-Carer)

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    Background: The ASCOT-Carer is a self-report instrument designed to measure social care-related quality of life (SCRQoL). This article presents the psychometric testing and validation of the ASCOT-Carer four response-level interview (INT4) in a sample of unpaid carers of adults who receive publicly-funded social care services in England. Methods: Unpaid carers were identified through a survey of users of publicly-funded social care services in England. 387 carers completed a face-to-face or telephone interview. Data on variables hypothesised to be related to SCRQoL (for example, characteristics of the carer, cared-for person and care situation) and measures of carer experience, strain, health-related quality of life and overall QoL were collected. Relationships between these variables and overall SCRQoL score were evaluated through correlation, ANOVA and regression analysis to test the construct validity of the scale. Internal reliability was assessed using Cronbach’s alpha and feasibility by the number of missing responses. Results: The construct validity was supported by statistically significant relationships between SCRQoL and scores on instruments of related constructs, as well as with characteristics of the carer and care recipient in univariate and multivariate analyses. A Cronbach’s alpha of 0.87 (7 items) indicates that the internal reliability of the instrument is satisfactory and a low number of missing responses (<1%) indicates a high level of acceptance. Conclusions: The results provide evidence to support the construct validity, factor structure, internal reliability and feasibility of the ASCOT-Carer INT4 as an instrument for measuring social care-related quality of life of unpaid carers who care for adults with a variety of long-term conditions, disability or problems related to old age

    Loop Quantum Gravity

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    The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a mathematically well-defined, non-perturbative and background independent quantization of general relativity, with its conventional matter couplings. The research in loop quantum gravity forms today a vast area, ranging from mathematical foundations to physical applications. Among the most significative results obtained are: (i) The computation of the physical spectra of geometrical quantities such as area and volume; which yields quantitative predictions on Planck-scale physics. (ii) A derivation of the Bekenstein-Hawking black hole entropy formula. (iii) An intriguing physical picture of the microstructure of quantum physical space, characterized by a polymer-like Planck scale discreteness. This discreteness emerges naturally from the quantum theory and provides a mathematically well-defined realization of Wheeler's intuition of a spacetime ``foam''. Long standing open problems within the approach (lack of a scalar product, overcompleteness of the loop basis, implementation of reality conditions) have been fully solved. The weak part of the approach is the treatment of the dynamics: at present there exist several proposals, which are intensely debated. Here, I provide a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.Comment: Review paper written for the electronic journal `Living Reviews'. 34 page
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