1,713 research outputs found

    Unirationality of moduli spaces of special cubic fourfolds and K3 surfaces

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    We provide explicit descriptions of the generic members of Hassett's divisors Cd\mathcal C_d for relevant 18d3818\leq d\leq 38 and for d=44d=44. In doing so, we prove that Cd\mathcal C_d is unirational for 18d38,d=4418\leq d\leq 38,d=44. As a corollary, we prove that the moduli space Nd\mathcal N_{d} of polarized K3 surfaces of degree dd is unirational for d=14,26,38d=14,26,38. The case d=26d=26 is entirely new, while the other two cases have been previously proven by Mukai.Comment: 13 pages, 2 tables. Script for the computer calculations used are provided on the author's websit

    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

    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

    Physicians' experiences and perspectives regarding the use of continuous sedation until death for cancer patients in the context of psychological and existential suffering at the end of life

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    OBJECTIVE: The use of continuous sedation until death for terminally ill cancer patients with unbearable and untreatable psychological and existential suffering remains controversial, and little in-depth insight exists into the circumstances in which physicians resort to it. METHODS: Our study was conducted in Belgium, the Netherlands, and the UK in hospitals, PCUs/hospices, and at home. We held interviews with 35 physicians most involved in the care of cancer patients who had psychological and existential suffering and had been continuously sedated until death. RESULTS: In the studied countries, three groups of patients were distinguished regarding the origin of their psychological and existential suffering. The first group had preexisting psychological problems before they became ill, the second developed psychological and existential suffering during their disease trajectory, and the third presented psychological symptoms that were characteristic of their disease. Before they resorted to the use of sedation, physicians reported that they had considered an array of pharmacological and psychological interventions that were ineffective or inappropriate to relieve this suffering. Necessary conditions for using sedation in this context were for most physicians the presence of refractory symptoms, a short life expectancy, and an explicit patient request for sedation. CONCLUSIONS: Physicians in our study used continuous sedation until death in the context of psychological and existential suffering after considering several pharmacological and psychological interventions. Further research and debate are needed on how and by whom this suffering at the end of life should be best treated, taking into account patients' individual preferences

    A mass spectrometric characterization of positive ions created in simple vacuum diodes incorporating oxide cathodes with supplementary analysis of background gases

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    Simple diodes were constructed utilizing oxide cathodes and nickel anodes. The cathodes were obtained by applying a mixture of barium, strontium, and calcium carbonates to a nickel filament and decomposing them to yield the oxides. The products of decomposition were analyzed by monitoring the composition of the background gases in the vacuum chamber. A portion of the flux of positive ions bombarding the cathode during diode operation was analyzed. It was possible to determine the region of origin of the ions and their potential energy at the time of formation. Positive ions of chlorine, fluorine, sodium, potassium, and rubidium were released at the anode surface when an emission current was drawn. The relative heights of the peaks due to ions created in the interelectrode space were very sensitive to processes occurring in the diode region. Changes in the shape of the peaks due to ions created in the interelectrode space were related to changes in the activity of the cathode and the amount of space charge surrounding the cathode. The transport of BaO was observed in the mass spectra taken at a cathode temperature of 1370ºC. Nondispersive x-ray analysis of the anode facing the cathode operated at 1370ºC revealed the presence of barium and strontium --Abstract, page ii

    The 'At-risk mental state' for psychosis in adolescents : clinical presentation, transition and remission.

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    Despite increased efforts over the last decade to prospectively identify individuals at ultra-high risk of developing a psychotic illness, limited attention has been specifically directed towards adolescent populations (<18 years). In order to evaluate how those under 18 fulfilling the operationalised criteria for an At-Risk Mental State (ARMS) present and fare over time, we conducted an observational study. Participants (N = 30) generally reported a high degree of functional disability and frequent and distressing perceptual disturbance, mainly in the form of auditory hallucinations. Seventy percent (21/30) were found to fulfil the criteria for a co-morbid ICD-10 listed mental health disorder, with mood (affective; 13/30) disorders being most prevalent. Overall transition rates to psychosis were low at 24 months follow-up (2/28; 7.1 %) whilst many participants demonstrated a significant reduction in psychotic-like symptoms. The generalisation of these findings may be limited due to the small sample size and require replication in a larger sample

    Supporting family carers providing end-of-life home care: a qualitative study on the impact of a hospice at home service

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    Aims and objectives: To explore bereaved family carers’ perceptions and experiences of a hospice at home service. Background: The increasing demand for the development of home-based end-of-life services is not confined to the westernworld; such services are also emerging in resource-poor countries where palliative care services are developing with limited inpatient facilities. Despite this growing trend, studies show a variety of interrelated factors, with an emphasis on the availability of informal carers and their ability to cope, which can influence whether terminally ill patients actually remain at home. A hospice at home service was developed to meet patients’ and families’ needs by providing individually tailored resources. Design. A qualitative study. Methods: Data were collected by semi-structured, digitally recorded interviews from 20 family carers who had experienced the service. Interviews were transcribed verbatim and a thematic approach adopted for analysis. Results: All participants reported a personal positive impact of the service. Family carers commented the service provided a valued presence, they felt in good hands and importantly it helped in supporting normal life. Conclusions: The impact of an individualised, targeted, hospice at home service using dedicated, palliative care trained, staff, is perceived positively by family carers and importantly, supportive of those with additional caring or employment commitments. Relevance to clinical practice: The emergence of hospice at home services has resulted in more options for patients and their families, when the increased amount of care a family member has to provide in these circumstances needs to be adequately supported, with the provision of a flexible service tailored to individual needs and delivered by appropriately trained staff

    Exploring dynamic lighting, colour and form with smart textiles

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    This paper addresses an ongoing research, aiming at the development of smart textiles that transform the incident light that passes through them – light transmittance – to design dynamic light without acting upon the light source. A colour and shape change prototype was developed with the objective of studying textile changes in time; to explore temperature as a dynamic variable through electrical activation of the smart materials and conductive threads integrated in the textile substrate; and to analyse the relation between textile chromic and morphologic behaviour in interaction with light. Based on the experiments conducted, results have highlighted some considerations of the dynamic parameters involved in the behaviour of thermo-responsive textiles and demonstrated design possibilities to create interactive lighting scenarios.This work is supported by FEDER funds through the Operational Programme for Competitiveness Factors – COMPETE and National Funds through FCT – Foundation for Science and Technology within the scope of the projects SFRH/BD/87196/2012, POCI-01-0145-FEDER-007136 and UID/CTM/00264. The authors also like to acknowledge Smart Textiles Design Lab for the support on the prototype development.info:eu-repo/semantics/publishedVersio

    A Mass Spectrometric Study Of Positive Ions Produced In An Experimental Diode

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    A simple diode ion source has been developed for direct observation in a mass spectrometer of the positive ions created in an operating diode. The ionic species accelerated toward the cathode were identified. The shape of the peak displayed in the spectrum is related to the region of the diode in which the ions were formed. Variation of experimental parameters, including the composition of the background gases, indicated that the characteristic shapes of the peaks can be related to space charge in the diode. This is complicated by the tendency of some of the species to fragment and further work is indicated before a complete understanding of the relations is obtained. Alkali and halogen ions were observed when an emission current was drawn. These species are assumed to be present as anode impurities. Heavy bombardment of the cathode by alkali ions is associated with an apparent increase in cathode activity. Heating an oxide cathode to temperatures as high as, or higher than, previous processing temperatures led to a further release of CO2 from the cathode. This additional release was not observed with the conventional mass spectrometer ion source thereby indicating that important observations concerning the state of the cathode may be missed when the ions which are analyzed are not created within the operating diode. © 1974

    Relationship of cognitive function in patients with schizophrenia in remission to disability: a cross-sectional study in an Indian sample

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    Background: Cognitive deficits in various domains have been consistently replicated in patients with schizophrenia. Most studies looking at the relationship between cognitive dysfunction and functional disability are from developed countries. Studies from developing countries are few. The purpose of the present study was to compare the neurocognitive function in patients with schizophrenia who were in remission with that of normal controls and to determine if there is a relationship between measures of cognition and functional disability. &lt;p/&gt;Methods: This study was conducted in the Psychiatric Unit of a General Hospital in Mumbai, India. Cognitive function in 25 patients with schizophrenia in remission was compared to 25 normal controls. Remission was confirmed using the brief psychiatric rating scale (BPRS) and scale for the assessment of negative symptoms (SANS). Subjects were administered a battery of cognitive tests covering aspects of memory, executive function and attention. The results obtained were compared between the groups. Correlation analysis was used to look for relationship between illness factors, cognitive function and disability measured using the Indian disability evaluation and assessment scale. &lt;p/&gt;Results: Patients with schizophrenia showed significant deficits on tests of attention, concentration, verbal and visual memory and tests of frontal lobe/executive function. They fared worse on almost all the tests administered compared to normal controls. No relationship was found between age, duration of illness, number of years of education and cognitive function. In addition, we did not find a statistically significant relationship between cognitive function and scores on the disability scale. &lt;p/&gt;Conclusion: The data suggests that persistent cognitive deficits are seen in patients with schizophrenia under remission. The cognitive deficits were not associated with symptomatology and functional disability. It is possible that various factors such as employment and family support reduce disability due to schizophrenia in developing countries like India. Further studies from developing countries are required to explore the relationship between cognitive deficits, functional outcome and the role of socio-cultural variables as protective factors
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