708 research outputs found

    Higher Spin Gravitational Couplings and the Yang--Mills Detour Complex

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    Gravitational interactions of higher spin fields are generically plagued by inconsistencies. We present a simple framework that couples higher spins to a broad class of gravitational backgrounds (including Ricci flat and Einstein) consistently at the classical level. The model is the simplest example of a Yang--Mills detour complex, which recently has been applied in the mathematical setting of conformal geometry. An analysis of asymptotic scattering states about the trivial field theory vacuum in the simplest version of the theory yields a rich spectrum marred by negative norm excitations. The result is a theory of a physical massless graviton, scalar field, and massive vector along with a degenerate pair of zero norm photon excitations. Coherent states of the unstable sector of the model do have positive norms, but their evolution is no longer unitary and their amplitudes grow with time. The model is of considerable interest for braneworld scenarios and ghost condensation models, and invariant theory.Comment: 19 pages LaTe

    Broadening the Debate About Post-trial Access to Medical Interventions: A Qualitative Study of Participant Experiences at the End of a Trial Investigating a Medical Device to Support Type 1 Diabetes Self-Management.

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    Increasing ethical attention and debate is focusing on whether individuals who take part in clinical trials should be given access to post-trial care. However, the main focus of this debate has been upon drug trials undertaken in low-income settings. To broaden this debate, we report findings from interviews with individuals (n = 24) who participated in a clinical trial of a closed-loop system, which is a medical device under development for people with type 1 diabetes that automatically adjusts blood glucose to help keep it within clinically recommended ranges. Individuals were recruited from UK sites and interviewed following trial close-out, at which point the closed-loop had been withdrawn. While individuals were stoical and accepting of the requirement to return the closed-loop, they also conveyed varying degrees of distress. Many described having relaxed diabetes management practices while using the closed-loop and having become deskilled as a consequence, which made reverting back to pre-trial regimens challenging. Participants also described unanticipated consequences arising from using a closed-loop. As well as deskilling, these included experiencing psychological and emotional benefits that could not be sustained after the closed-loop had been withdrawn and participants reevaluating their pre- and post-trial life in light of having used a closed-loop and now perceiving this life much more negatively. Participants also voiced frustrations about experiencing better blood glucose control using a closed-loop and then having to revert to using what they now saw as antiquated and imprecise self-management tools. We use these findings to argue that ethical debates about post-trial provisioning need to be broadened to consider potential psychological and emotional harms, and not just clinical harms, that may result from withdrawal of investigated treatments. We also suggest that individuals may benefit from information about potential nonclinical harms to help make informed decisions about trial participation.NIHR, JDR

    Initiating Insulin as Part of the Treating To Target in Type 2 Diabetes (4-T) Trial: An interview study of patients' and health professionals' experiences

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    OBJECTIVE: To explore patients' and health professionals' experiences of initiating insulin as part of the Treating To Target in Type 2 Diabetes (4-T) randomized controlled trial. RESEARCH DESIGN AND METHODS: Interviews were conducted with 45 trial participants and 21 health professionals and thematically analyzed. RESULTS: Patients were generally psychologically insulin receptive when approached to participate in the 4-T trial. Their receptiveness arose largely from their personal experiences observing intensifying prior treatments and deteriorating blood glucose control over time, which led them to engage with and accept the idea that their diabetes was progressive. Health professionals also fostered receptiveness by drawing on their clinical experience to manage patients' anxieties about initiating insulin. CONCLUSIONS: Previous studies may have overemphasized the problem of psychological insulin resistance and overlooked factors and treatment experiences that may promote insulin receptiveness among type 2 patients

    U(N|M) quantum mechanics on Kaehler manifolds

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    We study the extended supersymmetric quantum mechanics, with supercharges transforming in the fundamental representation of U(N|M), as realized in certain one-dimensional nonlinear sigma models with Kaehler manifolds as target space. We discuss the symmetry algebra characterizing these models and, using operatorial methods, compute the heat kernel in the limit of short propagation time. These models are relevant for studying the quantum properties of a certain class of higher spin field equations in first quantization.Comment: 21 pages, a reference adde

    Prevention is better than cure, but...: Preventive medication as a risk to ordinariness?

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    Preventive health remains at the forefront of public health concerns; recent initiatives, such as the NHS health check, may lead to recommendations for medication in response to the identification of 'at risk' individuals. Little is known about lay views of preventive medication. This paper uses the case of aspirin as a prophylactic against heart disease to explore views among people invited to screening for a trial investigating the efficacy of such an approach. Qualitative interviews (N=46) and focus groups (N=5, participants 31) revealed dilemmas about preventive medication in the form of clashes between norms: first, in general terms, assumptions about the benefit of prevention were complicated by dislike of medication; second, the individual duty to engage in prevention was complicated by the need not to be over involved with one's own health; third, the potential appeal of this alternative approach to health promotion was complicated by unease about the implications of encouraging irresponsible behaviour among others. Though respondents made different decisions about using the drug, they reported very similar ways of trying to resolve these conflicts, drawing upon concepts of necessity and legitimisation and the special ordinariness of the particular dru

    Long-Term Functionality of Rural Water Services in Developing Countries: A System Dynamics Approach to Understanding the Dynamic Interaction of Causal Factors

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    Research has shown that sustainability of rural water infrastructure in developing countries is largely affected by the dynamic and systemic interactions of technical, social, financial, institutional, and environmental factors that can lead to premature water system failure. This research employs systems dynamic modeling, which uses feedback mechanisms to understand how these factors interact dynamically to influence long-term rural water system functionality. To do this, the research first identified and aggregated key factors from literature, then asked water sector experts to indicate the polarity and strength between factors through Delphi and cross impact survey questionnaires, and finally used system dynamics modeling to identify and prioritize feedback mechanisms. The resulting model identified 101 feedback mechanisms that were dominated primarily by three and four-factor loops that contained some combination of the factors: Water System Functionality, Community, Financial, Government, Management, and Technology. These feedback mechanisms were then scored and prioritized, with the most dominant feedback mechanism identified as Water System Functionality – Community – Finance – Management. This research offers insight into the dynamic interaction of factors impacting sustainability of rural water infrastructure through the identification of these feedback mechanisms and makes a compelling case for future research to longitudinally investigate the interaction of these factors in various contexts

    Higher spin interactions with scalar matter on constant curvature spacetimes: conserved current and cubic coupling generating functions

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    Cubic couplings between a complex scalar field and a tower of symmetric tensor gauge fields of all ranks are investigated on any constant curvature spacetime of dimension d>2. Following Noether's method, the gauge fields interact with the scalar field via minimal coupling to the conserved currents. A symmetric conserved current, bilinear in the scalar field and containing up to r derivatives, is obtained for any rank r from its flat spacetime counterpart in dimension d+1, via a radial dimensional reduction valid precisely for the mass-square domain of unitarity in (anti) de Sitter spacetime of dimension d. The infinite collection of conserved currents and cubic vertices are summarized in a compact form by making use of generating functions and of the Weyl/Wigner quantization on constant curvature spaces.Comment: 35+1 pages, v2: two references added, typos corrected, enlarged discussions in Subsection 5.2 and in Conclusion, to appear in JHE
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