2,840 research outputs found

    Atmospheric Neutrinos and the Oscillations Bonanza

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    New observations with atmospheric neutrinos from the underground experiments SuperKamiokande, Soudan 2, and MACRO, together with earlier results from Kamiokande and IMB, are reviewed. The most recent observations reconfirm aspects of atmospheric flavor content and of zenith angle distributions which appear anomalous in the context of null oscillations. The anomalous trends, exhibited with high statistics in both sub-GeV and multi-GeV data of the SuperKamiokande water Cherenkov experiment, occur also in event samples recorded by the tracking calorimeters. The data are well-described by disappearence of nu_mu flavor neutrinos arising in oscillations with dominant two-state mixing, for which there exists a parameter region allowed by all experiments. In a new analysis by SuperKamiokande, nu_mu -> nu_tau is favored over nu_mu -> nu_s as the dominant oscillation based upon absence of oscillation suppression from matter effects at high energies. The possibility for sub-dominant nu_mu -> nu_e oscillations in atmospheric neutrinos which arises with three-flavor mixing, is reviewed, and intriguing possibilities for amplification of this oscillation by terrestrial matter-induced resonances are discussed. Developments and future measurements which will enhance our knowledge of the atmospheric neutrino fluxes are briefly noted.Comment: Plenary talk at the XIX Int. Symposium on Lepton and Photon Interactions at High Energies, Stanford, Aug. 1999, 28 pages, 16 figures; added a reference for section 1

    Depression in primary care patients with coronary heart disease: baseline findings from the UPBEAT UK study

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    BACKGROUND: An association between depression and coronary heart disease is now accepted but there has been little primary care research on this topic. The UPBEAT-UK studies are centred on a cohort of primary patients with coronary heart disease assessed every six months for up to four years. The aim of this research was to determine the prevalence and associations of depression in this cohort at baseline. METHOD: Participants with coronary heart disease were recruited from general practice registers and assessed for cardiac symptoms, depression, quality of life and social problems. RESULTS: 803 people participated. 42% had a documented history of myocardial infarction, 54% a diagnosis of ischaemic heart disease or angina. 44% still experienced chest pain. 7% had an ICD-10 defined depressive disorder. Factors independently associated with this diagnosis were problems living alone (OR 5.49, 95% CI 2.11-13.30), problems carrying out usual activities (OR 3.71, 95% CI 1.93-7.14), experiencing chest pain (OR 3.27, 95% CI 1.58-6.76), other pains or discomfort (OR 3.39, 95% CI 1.42-8.10), younger age (OR 0.95 per year 95% CI 0.92-0.98). CONCLUSION: Problems living alone, chest pain and disability are important predictors of depression in this population

    Quality of care: testing some measures in homes for elderly people

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    In this national study of 17 residential homes, 309 residents were interviewed, 264 members of staff completed an anonymous survey, and 228 relatives responded to a postal questionnaire. The data were collected between January andSeptember 1995. The aim of the study was to suggest promising measures of quality of care, looking particularly at depression as a possible indicator. It also served as a follow-up study of the Caring in Homes Initiative, although its timing ruled out evaluation of the impact of this development programme, because changes occurred in the homes before this study began. No strict definition of quality was adopted a priori, but a pragmatic approach was taken, addressing the perspectives of residents, health and social care professionals, home staff, managers, and relatives

    Apparent multiple Delta m^2_32 in muon anti-neutrino and muon neutrino survival oscillations from non-standard interaction matter effect

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    Neutrinos propagating through matter may participate in forward coherent neutral-current-like scattering arising from non-standard interactions as well as from the Mikheyev-Smirnov-Wolfenstein matter potential VeV_e. We show that at fixed long baselines through matter of constant density, the non-standard interaction potential ϵμτVe\epsilon_{\mu\tau} V_e can contribute an additional term to the oscillation phase whose sign differs for \anumu versus \numu propagation in matter. Its presence can cause different apparent Δm2\Delta m^2 to be erroneously inferred on the basis of oscillations in vacuum, with values lying above (for \anumu) or below (for \numu) the actual Δm322\Delta m^2_{32} for the case where ϵμτ\epsilon_{\mu\tau} is predominantly real-valued and of sign opposite to Δm322\Delta m_{32}^2. An NSI scenario invoking only ℜ(ϵμτ)\Re(\epsilon_{\mu\tau}) is shown to be capable of accounting for a disparity recently reported between oscillation survival for \anumu and \numu fluxes measured at 735 km735~\mathrm{km} by the MINOS experiment. Implications for mantle traversal by atmospheric neutrinos are examined. The NSI matter potential with non-maximal mixing could evade conventional atmospheric neutrino analyses which do not distinguish \numu from \anumu on an event-by-event basis.Comment: 7 pages, 5 figures. Accepted for publication in Physical Review

    Careers events : what works?

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    Desenvolvimento de escala para medir conceitos de esquizofrenia: experiência entre psiquiatras brasileiros

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    INTRODUCTION: Among psychiatric disorders schizophrenia is often said to be the condition with the most disputed definition.The Bleulerian and Schneiderian approaches have given rise to diagnostic formulations that have varied with time and place. Controversies over the concept of schizophrenia were examined within European/North American settings in the early 1970s but little has since been reported on the views of psychiatrists in developing countries. In Brazil both concepts are referred to in the literature. A scale was developed to measure adherence to Bleulerian and Schneiderian concepts among psychiatrists working in S. Paulo. METHODOLOGY: A self-reported questionnaire comprising seventeen visual analogue-scale statements related to Bleulerian and Schneiderian definitions of Shizophrenia, plus sociodemographic and training characteristics, was distributed to a non-randomised sample of 150 psychiatrists. The two sub-scales were assessed by psychometric methods for internal consistency, sub-scale structure and test-retest reliability. Items selected according to internal consistency were examined by a two-factor model exploratory factor analysis. Intraclass correlation coefficients described the stability of the scale. RESULTS: Replies were received from 117 psychiatrists (mean age 36 (SD 7.9)), 74% of whom were made and 26% female. The Schneiderian scale showed better overall internal consistency than the Bleulerian scale. Intra-class correlation coefficients for test-retest comparisons were between 0.5 and 0.7 for Schneiderian items and 0.2 and 0.7 for Bleulerian items. There was no negative association between Bleulerian and Schneiderian scale scores, suggesting that respondents may hold both concepts. Place of training was significantly associated with the respondent's opinion; disagreement with a Bleulerian standpoint predominated for those trained at the University of S. Paulo. CONCLUSIONS: The less satisfactory reliability for the Bleulerian sub-scale limits confidence in the whole scale but on the other hand this questionnaire contributes to the understanding of the controversy over Bleulerian and Schneiderian models for conceptualisation of schizophrenia, the former requiring more inference and therefore being prone to unreliability.INTRODUÇÃO: Foi desenvolvida uma escala para medir aderência ao conceito Bleuleriano e Schneideriano de esquizofrenia entre psiquiatras trabalhando em São Paulo, analisando relações entre variáveis sociodemográficas e de formação sobre o escore obtido. MÉTODOS: Questionário contendo escala visual analógica com dezessete enunciados sobre conceitos Schneideriano e Bleuleriano de esquizofrenia, foi distribuído para 150 psiquiatras. As sub-escalas Bleuleriana e Schneideriana foram avaliadas por metódos psicométricos de consistência interna, estrutura das subescalas e confiabilidade test- reteste. RESULTADOS: Completaram o questionário 117 psiquiatras. A subescala Schneideriana demonstrou melhor consistência interna e melhores coeficientes de correlação intraclasse. Não houve associação negativa entre os escores das subescalas. Discordância com o conceito Bleuleriano predominou entre profissionais treinados na USP. CONCLUSÕES: A baixa confiabilidade da sub-escala Bleuleriana limita a confiabilidade do instrumento como um todo, embora contribua para a discussão dos modelos em questão. Argumenta-se que o modelo Bleuleriano, por exigir maior inferência, torna-se propenso a baixa confiabilidade
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