1,421 research outputs found

    On the symplectic eightfold associated to a Pfaffian cubic fourfold

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    We show that the irreducible holomorphic symplectic eightfold Z associated to a cubic fourfold Y not containing a plane is deformation-equivalent to the Hilbert scheme of four points on a K3 surface. We do this by constructing for a generic Pfaffian cubic Y a birational map Z ---> Hilb^4(X), where X is the K3 surface associated to Y by Beauville and Donagi. We interpret Z as a moduli space of complexes on X and observe that at some point of Z, hence on a Zariski open subset, the complex is just the ideal sheaf of four points.Comment: 9 pages. Minor changes; to appear in Crelle as an appendix to 1305.017

    The development of a questionnaire to assess the attitudes of older people to end-of-life issues (AEOLI)

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    Objectives: To develop an end-of-life attitudes questionnaire for use in a large community-based sample of older people. Design: Nominal groups and standardization of questions. Participants: Eighteen older people, ten academics and five specialist palliative care health professionals were involved in nominal groups. Thirty older people took part in initial pilot work and a further 50 were involved in reliability testing. Results: A 27-item attitudes of older people to end-of-life issues (AEOLI) questionnaire. Discussion: In modern times, death and dying predominantly occurs among older people and yet we know very little about older people's attitudes to end-of-life care. The AEOLI questionnaire can be used in large scale surveys to elicit attitudes on end-of life issues considered important by older people and health care professionals

    Study program to develop and evaluate die and container materials for the growth of silicon ribbons

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    The development and evaluation of proprietary coatings of pure silicon carbide, silicon nitride, and aluminum nitride on less pure hot pressed substrates of the respective ceramic materials, is described. Silicon sessile drop experiments were performed on coated test specimens under controlled oxygen partial pressure. Prior to testing, X-ray diffraction and SEM characterization was performed. The reaction interfaces were characterized after testing with optical and scanning electron microscopy and Auger electron spectroscopy. Increasing the oxygen partial pressure was found to increase the molten silicon contact angle, apparently because adsorbed oxygen lowers the solid-vapor interfacial free energy. It was also found that adsorbed oxygen increased the degree of attack of molten silicon upon the chemical vapor deposited coatings. Cost projections show that reasonably priced, coated, molten silicon resistant refractory material shapes are obtainable

    A cohort study of the recovery of health and wellbeing following colorectal cancer (CREW study): protocol paper

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    Background: the number of people surviving colorectal cancer has doubled in recent years. While much of the literature suggests that most people return to near pre-diagnosis status following surgery for colorectal cancer, this literature has largely focused on physical side effects. Longitudinal studies in colorectal cancer have either been small scale or taken a narrow focus on recovery after surgery. There is a need for a comprehensive, long-term study exploring all aspects of health and wellbeing in colorectal cancer patients. The aim of this study is to establish the natural history of health and wellbeing in people who have been treated for colorectal cancer. People have different dispositions, supports and resources, likely resulting in individual differences in restoration of health and wellbeing. The protocol described in this paper is of a study which will identify who is most at risk of problems, assess how quickly people return to a state of subjective health and wellbeing, and will measure factors which influence the course of recovery. Methods: this is a prospective, longitudinal cohort study following 1000 people with colorectal cancer over a period of two years, recruiting from 30 NHS cancer treatment centres across the UK. Questionnaires will be administered prior to surgery, and 3, 9, 15 and 24 months after surgery, with the potential to return to this cohort to explore on-going issues related to recovery after cancer. Discussion: outcomes will help inform health care providers about what helps or hinders rapid and effective recovery from cancer, and identify areas for intervention development to aid this process. Once established the cohort can be followed up for longer periods and be approached to participate in related projects as appropriate and subject to funding<br/

    Can the Spitzer Quality of Life Index help to reduce prognostic uncertainty in terminal care?

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    Data from an on-going trial of co-ordinating care for terminally ill cancer patients are used to investigate whether the Spitzer Quality of Life (QL) Index can be used to reduce prognostic uncertainty in terminal care. Four questions are addressed. First, can doctors and nurses distinguish between patients with a prognosis of more or less than 1 year? Second, do the medical and nursing staff differ in their ability to estimate prognosis? Third, are there differences in the length of life remaining between groups of patients with different QL Index scores? Fourth, how well does the QL Index predict the likelihood of individual patients dying within 6 months of assessment? Doctors and nurses assigned between 17 and 25% of patients to the wrong prognostic group and were as likely to over-estimate as to under-estimate life expectancy. Medical and nursing staff did not differ in their ability to make prognostic judgements. Patients with a low QL Index score were more likely to die within 6 months than those with higher scores, but scores on the Index were not strong predictors of 6-month survival in individual patients. The Index is not accurate enough to be used to predict what sort of treatment terminally ill patients will require in the future and for how long. Nevertheless, it may prove valuable for those planning services for terminally ill cancer patients who require information on the levels of need in a population

    Substance use in clinical high risk for psychosis: a review of the literature

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    AimIn the literature, there is evidence suggesting an association between substance use and psychosis. However, little is known about substance use in those who may be in the pre-psychotic phase, that is, those who are putatively prodromal are considered to be at clinical high risk (CHR) of developing psychosis. MethodsWe conducted a review of publications measuring patterns and rates of substance use in CHR for psychosis individuals and the effects on the transition to psychosis. ResultsOf 5527 potentially relevant research papers, 10 met inclusion criteria of CHR subjects and specifically mentioned substance use in the sample. The results of these studies varied. Cannabis, alcohol and tobacco/nicotine were reported as the most commonly used substances. There was limited information on the changes in patterns of use over time. Two out of the ten studies found a significant association between the use of substances and subsequent transition to psychosis. In one of these studies, substance abuse was a predictor of psychosis when included as a variable in a prediction algorithm. In the other study, the abuse of cannabis and nicotine was associated with transition to psychosis. ConclusionsWe found limited evidence to suggest that increased rates of substance use may be associated with transition to psychosis. However, further prospective research examining the association between substance use and transition to psychosis is required before any firm conclusions can be made

    Barriers to providing palliative care for older people in acute hospitals

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    Background: the need for access to high-quality palliative care at the end of life is becoming of increasing public health concern. The majority of deaths in the UK occur in acute hospitals, and older people are particularly likely to die in this setting. However, little is known about the barriers to palliative care provision for older people within acute hospitals. Objective: to explore the perspectives of health professionals regarding barriers to optimal palliative care for older people in acute hospitals. Methods: fifty-eight health professionals participated in eight focus groups and four semi-structured interviews. Results: participants identified various barriers to palliative care provision for older people, including attitudinal differences to the care of older people, a focus on curative treatments within hospitals and a lack of resources. Participants also reported differing understandings of whose responsibility it was to provide palliative care for older people, and uncertainly over the roles of specialist and generalist palliative care providers in acute hospitals. Conclusions: numerous barriers exist to the provision of high-quality palliative care for older people within acute hospital settings. Additional research is now required to further explore age-related issues contributing to poor access to palliative care

    Evaluating Depressive Symptoms in Schizophrenia: A Psychometric Comparison of the Calgary Depression Scale for Schizophrenia and the Hamilton Depression Rating Scale

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    Background: The aim of this study was to compare two measures of depression in patients with schizophrenia and schizophrenia spectrum disorder, including patients with delusional and schizoaffective disorder, to conclude implications for their application. Sampling and Methods: A total of 278 patients were assessed using the Calgary Depression Scale for Schizophrenia (CDSS) and the Hamilton Depression Rating Scale (HAMD-17). The Positive and Negative Syndrome Scale (PANSS) was also applied. At admission and discharge, a principal component analysis was performed with each depression scale. The two depression rating scales were furthermore compared using correlation and regression analyses. Results: Three factors were revealed for the CDSS and HAMD-17 factor component analysis. A very similar item loading was found for the CDSS at admission and discharge, whereas results of the loadings of the HAMD-17 items were less stable. The first two factors of the CDSS revealed correlations with positive, negative and general psychopathology. In contrast, multiple significant correlations were found for the HAMD-17 factors and the PANSS sub-scores. Multiple regression analyses demonstrated that the HAMD-17 accounted more for the positive and negative symptom domains than the CDSS. Conclusions:The present results suggest that compared to the HAMD-17, the CDSS is a more specific instrument to measure depressive symptoms in schizophrenia and schizophrenia spectrum disorder, especially in acutely ill patients. Copyright (c) 2012 S. Karger AG, Base
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