513 research outputs found

    Production de tritium dans le thorium par des protons de 135 MeV

    Full text link
    We have measured the cross-section of tritium production by bombardement of thorium by 135 MeV protons in the Orsay synchro-cyclotron. The tritium was separated from the targets by heating in a graphite crucible with a high-frequency generator, under hydrogen gas pressure. Tritiated water was synthetised and the tritium was measured with liquid scintillator. A value of 19.5 ± 0.05 mbarns was obtained for the tritium-cross section and ten percent of tritons have energies higher than 35 MeV. This large cross-section is attributed to a double pick-up process.On a mesuré la section efficace de production de tritium après bombardment de thorium par des protons de 135 MeV accélérés au synchro-cyclotron d'Orsay. Le tritium était extrait des cibles par chauffage, dans un creuset de graphite, par courants H. F. sous atmosphère d'hydrogène. L'hydrogène tritié était ensuite transformé en eau tritiée et le tritium mesuré au moyen de scintillateur liquide. La section efficace obtenue est de 19,5 ± 0,5 mbarns et dix pour cent des tritons ont une énergie supérieure à 35 MeV. On attribue cette production à un processus de double pick-up

    Bounds on Integrals of the Wigner Function

    Get PDF
    The integral of the Wigner function over a subregion of the phase-space of a quantum system may be less than zero or greater than one. It is shown that for systems with one degree of freedom, the problem of determining the best possible upper and lower bounds on such an integral, over all possible states, reduces to the problem of finding the greatest and least eigenvalues of an hermitian operator corresponding to the subregion. The problem is solved exactly in the case of an arbitrary elliptical region. These bounds provide checks on experimentally measured quasiprobability distributions.Comment: 10 pages, 1 PostScript figure, Latex file; revised following referees' comments; to appear in Physical Review Letter

    Defining the cognitive phenotype of autism

    Get PDF
    Although much progress has been made in determining the cognitive profile of strengths and weaknesses that characterise individuals with autism spectrum disorders (ASDs), there remain a number of outstanding questions. These include how universal strengths and deficits are; whether cognitive subgroups exist; and how cognition is associated with core autistic behaviours, as well as associated psychopathology. Several methodological factors have contributed to these limitations in our knowledge, including: small sample sizes, a focus on single domains of cognition, and an absence of comprehensive behavioural phenotypic information. To attempt to overcome some of these limitations, we assessed a wide range of cognitive domains in a large sample (N = 100) of 14- to 16-year-old adolescents with ASDs who had been rigorously behaviourally characterised. In this review, we will use examples of some initial findings in the domains of perceptual processing, emotion processing and memory, both to outline different approaches we have taken to data analysis and to highlight the considerable challenges to better defining the cognitive phenotype(s) of ASDs. Enhanced knowledge of the cognitive phenotype may contribute to our understanding of the complex links between genes, brain and behaviour, as well as inform approaches to remediation

    Moving from development to implementation of digital innovations within the NHS: myHealthE, a remote monitoring system for tracking patient outcomes in child and adolescent mental health services

    Get PDF
    OBJECTIVE: This paper aims to report our experience of developing, implementing, and evaluating myHealthE (MHE), a digital innovation for Child and Adolescents Mental Health Services (CAMHS), which automates the remote collection and reporting of Patient-Reported Outcome Measures (PROMs) into National Health Services (NHS) electronic healthcare records. METHODS: We describe the logistical and governance issues encountered in developing the MHE interface with patient-identifiable information, and the steps taken to overcome these development barriers. We describe the application's architecture and hosting environment to enable its operability within the NHS, as well as the capabilities needed within the technical team to bridge the gap between academic development and NHS operational teams. RESULTS: We present evidence on the feasibility and acceptability of this system within clinical services and the process of iterative development, highlighting additional functions that were incorporated to increase system utility. CONCLUSION: This article provides a framework with which to plan, develop, and implement automated PROM collection from remote devices back to NHS infrastructure. The challenges and solutions described in this paper will be pertinent to other digital health innovation researchers aspiring to deploy interoperable systems within NHS clinical systems

    'Everyday memory' impairments in autism spectrum disorders

    Get PDF
    ‘Everyday memory’ is conceptualised as memory within the context of day-to-day life and, despite its functional relevance, has been little studied in individuals with autism spectrum disorders (ASDs). In the first study of its kind, 94 adolescents with an ASD and 55 without an ASD completed measures of everyday memory from the Rivermead Behavioural Memory Test (RBMT) and a standard word recall task (Children’s Auditory Verbal Learning Test-2: CAVLT-2). The ASD group showed significant impairments on the RBMT, including in prospective memory, alongside impaired performance on the CAVLT-2. Social and communication ability was significantly associated with prospective remembering in an everyday memory context but not with the CAVLT-2. The complex nature of everyday memory and its relevance to ASD is discussed

    Child and parent outcomes following parent interventions for child emotional and behavioral problems in autism spectrum disorders: A systematic review and meta-analysis

    Get PDF
    There is growing interest in the development of behavioral parent interventions targeting emotional and behavioral problems in children with autism spectrum disorders. Such interventions have potential to improve a number of child and parental well-being outcomes beyond disruptive child behavior. This systematic review and meta-analysis assesses evidence for the efficacy of behavioral parent interventions for disruptive and hyperactive child behavior in autism spectrum disorders, as well as parenting efficacy and stress. A total of 11 articles from nine randomized controlled trials were included. Sufficient data were available to calculate standardized mean difference and show favorable effects of behavioral parent interventions on parent-reported measures of child disruptive behavior (standardized mean difference = 0.67), hyperactivity (standardized mean difference = 0.31) and parent stress (standardized mean difference = 0.37); effects on parent efficacy are less clear (standardized mean difference = 0.39, p = 0.17). There were insufficient data to explore intervention effects on internalizing behavior in autism spectrum disorders, parenting behaviors, or observational and teacher-reported outcomes, providing important avenues for future research. This review adds to growing evidence of the efficacy of behavioral parent interventions for child behavior and parental well-being in autism spectrum disorders (Prospero: CRD42016033979)
    • …
    corecore