4,135 research outputs found

    Pareto versus lognormal: a maximum entropy test

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    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units

    Self-help materials for the prevention of smoking relapse: study protocol for a randomized controlled trial.

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    BACKGROUND: Most people who stop smoking successfully for a few weeks will return to smoking again in the medium term. There are few effective interventions to prevent this relapse and none used routinely in clinical practice. A previous exploratory meta-analysis suggested that self-help booklets may be effective but requires confirmation. This trial aims to evaluate the effectiveness and cost-effectiveness of a set of self-help educational materials to prevent smoking relapse in the National Health Service (NHS) Stop Smoking Service. METHODS/DESIGN: This is an open, randomized controlled trial. The target population is carbon monoxide (CO) verified quitters at four weeks in the NHS stop smoking clinic (total sample size N = 1,400). The experimental intervention tested is a set of eight revised Forever Free booklets, including an introduction booklet and more extensive information on all important issues for relapse prevention. The control intervention is a leaflet that has no evidence to suggest it is effective but is currently given to some patients using NHS stop smoking services. Two follow-up telephone interviews will be conducted at three and 12 months after the quit date. The primary outcome will be prolonged abstinence from months four to 12 with no more than five lapses, confirmed by a CO test at the 12-month assessment. The secondary outcomes will be seven-day self-report point prevalence abstinence at three months and seven-day biochemically confirmed point prevalence abstinence at 12 months. To assess cost-effectiveness, costs will be estimated from a health service perspective and the EQ-5D will be used to estimate the QALY (Quality Adjusted Life Year) gain associated with each intervention. The comparison of smoking abstinence rates (and any other binary outcomes) between the two trial arms will be carried out using odds ratio as the outcome statistic and other related statistical tests. Exploratory subgroup analyses, including logistic regression analyses with interaction terms, will be conducted to investigate possible effect-modifying variables. DISCUSSION: The possible effect of self-help educational materials for the prevention of smoking relapse has important public health implications. TRIAL REGISTRATION: Current Controlled Trials ISRCTN36980856.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Successful ageing : perceptions of adults aged between 70 and 101 years

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    In this research, content analysis was employed to investigate older adults\u27 perceptions of successful aging and the relationship of these perceptions to definitions given in the literature to date. Participants were 18 males and 42 females between the ages of 70 and 101 years. Analyses revealed older adults mentioned only 1 or 2 criteria of successful aging if asked for a definition; however, when prompted, they rated almost all the criteria emerging from the literature as highly important. Participants reported adjusting to the situations they were in by compensating for losses that occurred and selecting activities that best suited their capabilities. Overall, older adults\u27 perceptions of successful aging were similar to aspects identified in the literature. Not all aspects, however, were seen as important by all participants, and only low to moderate correlations were found between some aspects of successful aging. (Contains 3 figures and 4 tables.)<br /

    Effect of Silicon Content on Carbide Precipitation and Low-Temperature Toughness of Pressure Vessel Steels

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    Cr – Mn – Mo – Ni pressure vessel steels containing 0.54 and 1.55% Si are studied. Metallographic and fractographic analyses of the steels after tempering at 650 and 700°C are performed. The impact toughness at – 30°C and the hardness of the steels are determined. The mass fraction of the carbide phase in the steels is computed with the help of the J-MatPro 4.0 software

    Self-help educational booklets for the prevention of smoking relapse following smoking cessation treatment: a randomized controlled trial.

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    AIMS: Most people who quit smoking for a short term will return to smoking again in 12 months. We tested whether self-help booklets can reduce relapse in short-term quitters after receiving behavioural and pharmacological cessation treatment. DESIGN: A parallel-arm, pragmatic individually randomized controlled trial. SETTING: Smoking cessation clinics in England. Participants People who stopped smoking for 4 weeks after receiving cessation treatment in stop smoking clinics. INTERVENTION: Participants in the experimental group (n=703) were mailed eight booklets, each of which taught readers how to resist urges to smoke. Participants in the control group (n=704) received a leaflet currently used in practice. MEASUREMENTS: The primary outcome was prolonged, carbon monoxide-verified abstinence from months 4 to 12. The secondary outcomes included 7-day self-reported abstinence at 3 and 12 months. Mixed-effects logistic regression was used to estimate treatment effects and to investigate possible effect modifying variables. FINDINGS: There were no statistically significant differences between the groups in prolonged abstinence from months 4 to 12 (36.9% versus 38.6%; odds ratio 0.93, 95% confidence interval 0.75-1.16; P=0.524). In addition, there were no significant differences between the groups in any secondary outcomes. However, people who reported knowing risky situations for relapse and using strategies to handle urges to smoke were less likely to relapse. CONCLUSIONS: In people who stop smoking successfully with behavioural support, a comprehensive self-help educational programme to teach people skills to identify and respond to high-risk situations for return to smoking did not reduce relapse

    Application of COMPOCHIP Microarray to Investigate the Bacterial Communities of Different Composts

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    A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts

    Change management: The case of the elite sport performance team

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    The effective and efficient implementation of change is often required for both successful performance and management survival across a host of contemporary domains. However, although of major theoretical and practical significance, research to date has overlooked the application of change management (hereafter CM) knowledge to the elite sport performance team environment. Considering that the success of ‘off-field’ sports businesses are largely dependent on the performances of their ‘on-field’ team, this article explores the application of current CM theorizing to this specific setting and the challenges facing its utility. Accordingly, we identify the need and importance of developing theory specific to this area, with practical application in both sport and business, through examination of current knowledge and identification of the domain's unique, dynamic and contested properties. Markers of successful change are then suggested to guide initial enquiry before the article concludes with proposed lines of research which may act to provide a valid and comprehensive theoretical account of CM to optimize the research and practice of those working in the field

    Development and evaluation of a de-escalation training intervention in adult acute and forensic units: the EDITION systematic review and feasibility trial.

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    Containment (e.g. physical restraint and seclusion) is used frequently in mental health inpatient settings. Containment is associated with serious psychological and physical harms. De-escalation (psychosocial techniques to manage distress without containment) is recommended to manage aggression and other unsafe behaviours, for example self-harm. All National Health Service staff are trained in de-escalation but there is little to no evidence supporting training's effectiveness. Objectives were to: (1) qualitatively investigate de-escalation and identify barriers and facilitators to use across the range of adult acute and forensic mental health inpatient settings; (2) co-produce with relevant stakeholders an intervention to enhance de-escalation across these settings; (3) evaluate the intervention's preliminary effect on rates of conflict (e.g. violence, self-harm) and containment (e.g. seclusion and physical restraint) and understand barriers and facilitators to intervention effects. Intervention development informed by Experience-based Co-design and uncontrolled pre and post feasibility evaluation. Systematic reviews and qualitative interviews investigated contextual variation in use and effects of de-escalation. Synthesis of this evidence informed co-design of an intervention to enhance de-escalation. An uncontrolled feasibility trial of the intervention followed. Clinical outcome data were collected over 24 weeks including an 8-week pre-intervention phase, an 8-week embedding and an 8-week post-intervention phase. Ten inpatient wards (including acute, psychiatric intensive care, low, medium and high secure forensic) in two United Kingdom mental health trusts. In-patients, clinical staff, managers, carers/relatives and training staff in the target settings. Enhancing de-escalation techniques in adult acute and forensic units: Development and evaluation of an evidence-based training intervention (EDITION) interventions included de-escalation training, two novel models of reflective practice, post-incident debriefing and feedback on clinical practice, collaborative prescribing and ward rounds, practice changes around admission, shift handovers and the social and physical environment, and sensory modulation and support planning to reduce patient distress. Outcomes measured related to feasibility (recruitment and retention, completion of outcome measures), training outcomes and clinical and safety outcomes. Conflict and containment rates were measured via the Patient-Staff Conflict Checklist. Clinical outcomes were measured using the Attitudes to Containment Measures Questionnaire, Attitudes to Personality Disorder Questionnaire, Violence Prevention Climate Scale, Capabilities, Opportunities, and Motivation Scale, Coercion Experience Scale and Perceived Expressed Emotion in Staff Scale. Completion rates of the proposed primary outcome were very good at 68% overall (excluding remote data collection), which increased to 76% (excluding remote data collection) in the post-intervention period. Secondary outcomes had high completion rates for both staff and patient respondents. Regression analyses indicated that reductions in conflict and containment were both predicted by study phase (pre, embedding, post intervention). There were no adverse events or serious adverse events related to the intervention. Intervention and data-collection procedures were feasible, and there was a signal of an effect on the proposed primary outcome. Uncontrolled design and self-selecting sample. Definitive trial determining intervention effects. This trial is registered as ISRCTN12826685 (closed to recruitment). This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/101/02) and is published in full in ; Vol. 28, No. 3. See the NIHR Funding and Awards website for further award information. Conflict (a term used to describe a range of potentially unsafe events including violence, self-harm, rule-breaking, medication refusal, illicit drug and alcohol use and absconding) in mental health settings causes serious physical and psychological harm. Containment interventions which are intended to minimise harm from violence (and other conflict behaviours) such as restraint, seclusion and rapid tranquilisation can result in serious injuries to patients and, occasionally, death. Involvement in physical restraint is the most common cause of serious physical injury to National Health Service mental health staff in the United Kingdom. Violence to staff results in substantial costs to the health service in sickness and litigation payments. Containment interventions are also expensive (e.g. physical restraint costs mental health services £6.1 million and enhanced observations £88 million per annum). Despite these harms, recent findings indicate containment interventions such as seclusion and physical restraint continue to be used frequently in mental health settings. Clinical trials have demonstrated that interventions can reduce containment without increasing violence and other conflict behaviours (e.g. verbal aggression, self-harm). Substantial cost-savings result from reducing containment use. De-escalation, as an intervention to manage aggression and potential violence without restrictive practices, is a core intervention. 'De-escalation' is a collective term for a range of psychosocial techniques designed to reduce distress and anger without the need to use 'containment' interventions (measures to prevent harm through restricting a person's ability to act independently, such as physical restraint and seclusion). Evidence indicates that de-escalation involves ensuring conditions for safe intervention and effective communication are established, clarifying and attempting to resolve the patient's concern, conveyance of respect and empathy and regulating unhelpful emotions such as anxiety and anger. Despite featuring prominently in clinical guidelines and training policy domestically and internationally and being a component of mandatory National Health Service training, there is no evidence-based model on which to base training. A systematic review of de-escalation training effectiveness and acceptability conducted in 2015 concluded: (1) no model of training has demonstrated effectiveness in a sufficiently rigorous evaluation, (2) the theoretical underpinning of evaluated models was often unclear and (3) there has been inadequate investigation of the characteristics of training likely to enhance acceptability and uptake. Despite all National Health Service staff being trained in de-escalation there have been no high-quality trials evaluating the effectiveness and cost-effectiveness of training. Feasibility studies are needed to establish whether it is possible to conduct a definitive trial that can determine the clinical, safety and cost-effectiveness of this intervention
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