1,118 research outputs found

    The Geometry of D=11 Killing Spinors

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    We propose a way to classify all supersymmetric configurations of D=11 supergravity using the G-structures defined by the Killing spinors. We show that the most general bosonic geometries admitting a Killing spinor have at least a local SU(5) or an (Spin(7)\ltimes R^8)x R structure, depending on whether the Killing vector constructed from the Killing spinor is timelike or null, respectively. In the former case we determine what kind of local SU(5) structure is present and show that almost all of the form of the geometry is determined by the structure. We also deduce what further conditions must be imposed in order that the equations of motion are satisfied. We illustrate the formalism with some known solutions and also present some new solutions including a rotating generalisation of the resolved membrane solutions and generalisations of the recently constructed D=11 Godel solution.Comment: 36 pages. Typos corrected and discussion on G-structures improved. Final version to appear in JHE

    The perseverance of Pacioli's goods inventory accounting system

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    This paper details sources of the 'undoubtedly strange' (Yamey, 1994a, p.119) system of goods inventory records described in Pacioli’s 1494 bookkeeping treatise and traces the longevity and widespread use of this early perpetual inventory recording (EPIR) system in English language texts. By doing so and contrasting this system with the bookkeeping treatment of modern texts, it is shown that the EPIR system persisted as the dominant form of goods inventory accounting for between 400 and 500 years and that the reasons for its demise are worthy of further consideration and research

    Visually Impaired OLder people's Exercise programme for falls prevenTion (VIOLET): a feasibility study

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    This study aims to conduct a mixed methods feasibility study to inform the design and conduct of a future definitive RCT of an adapted exercise programme to prevent falls by reducing fear of falling among older people with visual impairment (OPVI). The research questions are: can an existing exercise programme be adapted for OPVI and successfully delivered in the community; is it feasible to conduct an RCT of this intervention and what are the features of a future definitive trial? We propose to: (i) Adapt an existing exercise programme with the full involvement of OPVI and practitioners; (ii) Run a feasibility study in 2 sites to test our proposed measures, trial processes and recruitment; explore acceptability of the intervention; fidelity of and compliance with the intervention. Two stakeholder panels will be established including OPVI aged 60 and over from Newcastle Society for Blind People (NSBP) and Visibility in Glasgow, practitioners and researchers. They will work together to adapt the FaME programme, which is known to be effective in reducing falls in frequent fallers, so that the methods are acceptable for OPVI, whilst retaining the effective components of the exercise. The panels will meet 4 times to adapt the intervention and contribute to decisions on outcome measures and data collection. During this time we will identify OPVI wishing to act as expert stakeholders in the subsequent WPs. OPVI aged 60+ will be recruited from low vision clinics and voluntary organisations and randomised into the intervention or comparator arm. Those in the comparator arm will receive no intervention, but will be offered it after final data collection. The core components of the adapted exercise programme aim to strengthen leg muscles and retrain balance. However, the detail of the methods and timing will be decided by the stakeholder panel. The programme is likely to run once a week over 12 weeks, with each session lasting up to one hour. The final form of delivery will be one of the outcomes of the PPI work in WP1. Participants will be provided with instructions and equipment to do the exercises at home if they wish. The intervention will be delivered by exercise instructors engaged by Health Works, Newcastle and Visibility, Glasgow, in venues agreed with participants. The final primary outcome of the future RCT will be decided by the responsiveness to change, participant burden and participant feedback from this study. The likely candidate primary outcome is fear of falling (Short FES-I scale). The main secondary outcomes will be: activity avoidance; balance/falls risk; number of falls; quality of life; loneliness; depression; adherence to exercise programme; self-reported home exercising. An estimate of cost effectiveness and cost utility of the intervention will be undertaken. In-depth interviews with a sample of OPVI will be conducted to explore their reasons for taking part/not taking part; factors that facilitate/hinder them from participating in exercise groups; their experiences of the recruitment and randomisation process and views on the outcome measures; their experience of the adapted intervention. The interviews will highlight site specific issues to consider for the definitive RCT. Structured interviews will be undertaken with commissioners and practitioners to explore their perspectives on the application of the intervention

    Economic assessment of use of pond ash in pavements

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    The paper introduces a new type of industrial waste-based subbase material which can replace conventional subbase material (CSM) in pavement construction. Utilisation of this industrial waste, namely pond coal ash produced from a thermal power plant in road construction will help to reduce the disposal problem of this waste and also will help to reduce the problem of scarcity of CSM. Lime and fibre were also added to the pond ash at various percentages to improve the suitability of this type of mix as subbase material. The optimum service life of pavement is studied with the help of numerical modelling and the cost benefit is also presented in the current study. The study reveals that stabilisation of the coal ash with 2% lime may produce an optimal material and, even though a greater thickness may be required to deliver the same pavement performance, direct cost savings of around 10% may be achieved in addition to less easily quantifiable environmental benefits. Design charts are provided to exploit the findings

    Early mortality among Aboriginal and non-Aboriginal women who had a preterm birth in Western Australia: A population-based cohort study

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    Background: Having a preterm (<37 weeks' gestation) birth may increase a woman's risk of early mortality. Aboriginal and Torres Strait Islander (hereafter Aboriginal) women have higher preterm birth and mortality rates compared with other Australian women. Objectives: We investigated whether a history of having a preterm birth was associated with early mortality in women and whether these associations differed by Aboriginal status. Methods: This retrospective cohort study used population-based perinatal records of women who had a singleton birth between 1980 and 2015 in Western Australia linked to Death Registry data until June 2018. The primary and secondary outcomes were all-cause and cause-specific mortality respectively. After stratification by Aboriginal status, rate differences were calculated, and Cox proportional hazard regression was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for allcause and cause-specific mortality. Results: There were 20,244 Aboriginal mothers (1349 deaths) and 457,357 nonAboriginal mothers (7646 deaths) with 8.6 million person-years of follow-up. The all-cause mortality rates for Aboriginal mothers who had preterm births and term births were 529.5 and 344.0 (rate difference 185.5, 95% CI 135.5, 238.5) per 100,000 person-years respectively. Among non-Aboriginal mothers, the corresponding figures were 125.5 and 88.6 (rate difference 37.0, 95% CI 29.4, 44.9) per 100,000 personyears. The HR for all-cause mortality for Aboriginal and non-Aboriginal mothers associated with preterm birth were 1.48 (95% CI 1.32, 1.66) and 1.35 (95% CI 1.26, 1.44), respectively, compared with term birth. Compared with mothers who had term births, mothers of preterm births had higher relative risks of mortality from diabetes, cardiovascular, digestive and external causes. Conclusions: Both Aboriginal and non-Aboriginal women who had a preterm birth had a moderately increased risk of mortality up to 38 years after the birth, reinforcing the importance of primary prevention and ongoing screening.Helen D. Bailey, Caitlin Gray, Akilew A. Adane, Natalie A. Strobel, Scott W. White, Rhonda Marriott, Gizachew A. Tessema, Carrington C. J. Shepherd, Mary Shar

    The AMANDA Neutrino Telescope

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    With an effective telescope area of order 10410^4 m2^2 for TeV neutrinos, a threshold near \sim50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.Comment: 12 pages, Latex2.09, uses espcrc2.sty and epsf.sty, 13 postscript files included. Talk presented at the 18th International Conference on Neutrino Physics and Astrophysics (Neutrino 98), Takayama, Japan, June 199

    Production and Decay of D_1(2420)^0 and D_2^*(2460)^0

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    We have investigated D+πD^{+}\pi^{-} and D+πD^{*+}\pi^{-} final states and observed the two established L=1L=1 charmed mesons, the D1(2420)0D_1(2420)^0 with mass 242122+1+22421^{+1+2}_{-2-2} MeV/c2^{2} and width 2053+6+320^{+6+3}_{-5-3} MeV/c2^{2} and the D2(2460)0D_2^*(2460)^0 with mass 2465±3±32465 \pm 3 \pm 3 MeV/c2^{2} and width 2876+8+628^{+8+6}_{-7-6} MeV/c2^{2}. Properties of these final states, including their decay angular distributions and spin-parity assignments, have been studied. We identify these two mesons as the jlight=3/2j_{light}=3/2 doublet predicted by HQET. We also obtain constraints on {\footnotesize ΓS/(ΓS+ΓD)\Gamma_S/(\Gamma_S + \Gamma_D)} as a function of the cosine of the relative phase of the two amplitudes in the D1(2420)0D_1(2420)^0 decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by sending mail to: [email protected]

    Measurement of the branching fraction for Υ(1S)τ+τ\Upsilon (1S) \to \tau^+ \tau^-

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    We have studied the leptonic decay of the Υ(1S)\Upsilon (1S) resonance into tau pairs using the CLEO II detector. A clean sample of tau pair events is identified via events containing two charged particles where exactly one of the particles is an identified electron. We find B(Υ(1S)τ+τ)=(2.61 ± 0.12 +0.090.13)B(\Upsilon(1S) \to \tau^+ \tau^-) = (2.61~\pm~0.12~{+0.09\atop{-0.13}})%. The result is consistent with expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS 94/1297, CLEO 94-20 (submitted to Physics Letters B

    Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 Decaying to D_s^*+ pi^0 and Confirmation of the D_sJ^* (2317) State

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    Using 13.5 inverse fb of e+e- annihilation data collected with the CLEO II detector we have observed a narrow resonance in the Ds*+pi0 final state, with a mass near 2.46 GeV. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV, the DsJ*(2317)+ that decays to Ds+pi0. Reconstructing the Ds+pi0 and Ds*+pi0 final states in CLEO data, we observe peaks in both of the corresponding reconstructed mass difference distributions, dM(Dspi0)=M(Dspi0)-M(Ds) and dM(Ds*pi0)=M(Ds*pi0)-M(Ds*), both of them at values near 350 MeV. We interpret these peaks as signatures of two distinct states, the DsJ*(2317)+ plus a new state, designated as the DsJ(2463)+. Because of the similar dM values, each of these states represents a source of background for the other if photons are lost, ignored or added. A quantitative accounting of these reflections confirms that both states exist. We have measured the mean mass differences = 350.0 +/- 1.2 [stat] +/- 1.0 [syst] MeV for the DsJ*(2317) state, and = 351.2 +/- 1.7 [stat] +/- 1.0 [syst] MeV for the new DsJ(2463)+ state. We have also searched, but find no evidence, for decays of the two states via the channels Ds*+gamma, Ds+gamma, and Ds+pi+pi-. The observations of the two states at 2.32 and 2.46 GeV, in the Ds+pi0 and Ds*+pi0 decay channels respectively, are consistent with their interpretations as (c anti-strange) mesons with orbital angular momentum L=1, and spin-parities of 0+ and 1+.Comment: 16 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, version to be published in Physical Review D; minor modifications and fixes to typographical errors, plus an added section on production properties. The main results are unchanged; they supersede those reported in hep-ex/030501
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