710 research outputs found

    Cascade Failure in a Phase Model of Power Grids

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    We propose a phase model to study cascade failure in power grids composed of generators and loads. If the power demand is below a critical value, the model system of power grids maintains the standard frequency by feedback control. On the other hand, if the power demand exceeds the critical value, an electric failure occurs via step out (loss of synchronization) or voltage collapse. The two failures are incorporated as two removal rules of generator nodes and load nodes. We perform direct numerical simulation of the phase model on a scale-free network and compare the results with a mean-field approximation.Comment: 7 pages, 2 figure

    Developing the content of two behavioural interventions : using theory-based interventions to promote GP management of upper respiratory tract infection without prescribing antibiotics #1

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    Background: Evidence shows that antibiotics have limited effectiveness in the management of upper respiratory tract infection (URTI) yet GPs continue to prescribe antibiotics. Implementation research does not currently provide a strong evidence base to guide the choice of interventions to promote the uptake of such evidence-based practice by health professionals. While systematic reviews demonstrate that interventions to change clinical practice can be effective, heterogeneity between studies hinders generalisation to routine practice. Psychological models of behaviour change that have been used successfully to predict variation in behaviour in the general population can also predict the clinical behaviour of healthcare professionals. The purpose of this study was to design two theoretically-based interventions to promote the management of upper respiratory tract infection (URTI) without prescribing antibiotics. Method: Interventions were developed using a systematic, empirically informed approach in which we: selected theoretical frameworks; identified modifiable behavioural antecedents that predicted GPs intended and actual management of URTI; mapped these target antecedents on to evidence-based behaviour change techniques; and operationalised intervention components in a format suitable for delivery by postal questionnaire. Results: We identified two psychological constructs that predicted GP management of URTI: "Self-efficacy," representing belief in one's capabilities, and "Anticipated consequences," representing beliefs about the consequences of one's actions. Behavioural techniques known to be effective in changing these beliefs were used in the design of two paper-based, interactive interventions. Intervention 1 targeted self-efficacy and required GPs to consider progressively more difficult situations in a "graded task" and to develop an "action plan" of what to do when next presented with one of these situations. Intervention 2 targeted anticipated consequences and required GPs to respond to a "persuasive communication" containing a series of pictures representing the consequences of managing URTI with and without antibiotics. Conclusion: It is feasible to systematically develop theoretically-based interventions to change professional practice. Two interventions were designed that differentially target generalisable constructs predictive of GP management of URTI. Our detailed and scientific rationale for the choice and design of our interventions will provide a basis for understanding any effects identified in their evaluation. Trial registration: Clinicaltrials.gov NCT00376142This study is funded by the European Commission Research Directorate as part of a multi-partner program: Research Based Education and Quality Improvement (ReBEQI): A Framework and tools to develop effective quality improvement programs in European healthcare. (Proposal No: QLRT-2001-00657)

    The Increasing Diversity and Complexity of Family Structures for Adolescents

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    The structure of adolescentsā€™ families, and thus parental forms, in the United States, have become more heterogeneous and fluid over the past several decades. These changes are due to increases in neverā€married, single parents, divorce, cohabitation, sameā€sex parenting, multipartnered fertility, and coā€residence with grandparents. We document current diversity and complexity in adolescentsā€™ families as important context for rethinking future parenting theory and research. We also discuss how understandings of adolescentsā€™ families are somewhat limited by current methods used to measure characteristics of families. We recommend social network and profileā€based methods as alternatives to capturing key dimensions of family structure and processes. Understanding the diversity of households and families in which adolescents are raised can improve theory and research on parenting

    Translating clinicians' beliefs into implementation interventions (TRACII) : a protocol for an intervention modeling experiment to change clinicians' intentions to implement evidence-based practice

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    Background: Biomedical research constantly produces new findings, but these are not routinely incorporated into health care practice. Currently, a range of interventions to promote the uptake of emerging evidence are available. While their effectiveness has been tested in pragmatic trials, these do not form a basis from which to generalise to routine care settings. Implementation research is the scientific study of methods to promote the uptake of research findings, and hence to reduce inappropriate care. As clinical practice is a form of human behaviour, theories of human behaviour that have proved to be useful in other settings offer a basis for developing a scientific rationale for the choice of interventions. Aims: The aims of this protocol are 1) to develop interventions to change beliefs that have already been identified as antecedents to antibiotic prescribing for sore throats, and 2) to experimentally evaluate these interventions to identify those that have the largest impact on behavioural intention and behavioural simulation. Design: The clinical focus for this work will be the management of uncomplicated sore throat in general practice. Symptoms of upper respiratory tract infections are common presenting features in primary care. They are frequently treated with antibiotics, and research evidence is clear that antibiotic treatment offers little or no benefit to otherwise healthy adult patients. Reducing antibiotic prescribing in the community by the "prudent" use of antibiotics is seen as one way to slow the rise in antibiotic resistance, and appears safe, at least in children. However, our understanding of how to do this is limited. Participants will be general medical practitioners. Two theory-based interventions will be designed to address the discriminant beliefs in the prescribing of antibiotics for sore throat, using empirically derived resources. The interventions will be evaluated in a 2 Ɨ 2 factorial randomised controlled trial delivered in a postal questionnaire survey. Two outcome measures will be assessed: behavioural intention and behavioural simulation.This study is funded by the European Commission Research Directorate as part of a multi-partner program: Research Based Education and Quality Improvement (ReBEQI): A Framework and tools to develop effective quality improvement programs in European healthcare. (Proposal No: QLRT-2001-00657)

    Disaggregating the Distal, Proximal, and Time-Varying Effects of Parent Alcoholism on Childrenā€™s Internalizing Symptoms

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    Abstract We tested whether children show greater internalizing symptoms when their parents are actively abusing alcohol. In an integrative data analysis, we combined observations over ages 2 through 17 from two longitudinal studies of children of alcoholic parents and matched controls recruited from the community. Using a mixed modeling approach, we tested whether children showed elevated mother- and child-reported internalizing symptoms(a) at the same time that parents showed alcohol-related consequences (time-varying effects), (b) if parents showed greater alcohol-related consequences during the study period (proximal effects), and (c) if parents had a lifetime diagnosis of alcoholism that predated the study period(distal effects). No support for time-varying effects was found; proximal effects of mothersā€™ alcohol-related consequences on child-reported internalizing symptoms were found and distal effects of mother and father alcoholism predicted greater internalizing symptoms among children of alcoholic parents. Implications for the time-embedded relations between parent alcoholism and childrenā€™s internalizing symptoms are discussed.This work was supported by grant R01 DA15398 to AMH and R01 DA013148 to PJC. The work was also supported by grant R37 AA 07065 to RAZ and grant R01 AA16213 to LACPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64510/1/#162, Hussong 2008, Disaggregating the distal, proximal, and time-varying effects of parent alcoholism on children's internalizing symptoms.pd

    Approaches to quality improvement in nursing homes: Lessons learned from the six-state pilot of CMS's Nursing Home Quality Initiative

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    BACKGROUND: In November 2002, the Centers for Medicare & Medicaid Services (CMS) launched a Nursing Home Quality Initiative that included publicly reporting a set of Quality Measures for all nursing homes in the country, and providing quality improvement assistance to nursing homes nationwide. A pilot of this initiative occurred in six states for six months prior to the launch. METHODS: Review and analysis of the lessons learned from the six Quality Improvement Organizations (QIOs) that led quality improvement efforts in nursing homes from the six pilot states. RESULTS: QIOs in the six pilot states found several key outcomes of the Nursing Home Quality Initiative that help to maximize the potential of public reporting to leverage effective improvement in nursing home quality of care. First, public reporting focuses the attention of all stakeholders in the nursing home industry on achieving good quality outcomes on a defined set of measures, and creates an incentive for partnership formation. Second, publicly reported quality measures motivate nursing home providers to improve in certain key clinical areas, and in particular to seek out new ways of changing processes of care, such as engaging physicians and the medical director more directly. Third, the lessons learned by QIOs in the pilot of this Initiative indicate that certain approaches to providing quality improvement assistance are key to guiding nursing home providers' desire and enthusiasm to improve towards a using a systematic approach to quality improvement. CONCLUSION: The Nursing Home Quality Initiative has already demonstrated the potential of public reporting to foster collaboration and coordination among nursing home stakeholders and to heighten interest of nursing homes in quality improvement techniques. The lessons learned from this pilot project have implications for any organizations or individuals planning quality improvement projects in the nursing home setting

    Social marketing and social influences: Using social ecology as a theoretical framework

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    Social marketing has traditionally been dominated by an individualistic model of design. In this work, the authors apply a social ecology model to the theory and practice of social marketing, demonstrating that a multilevel framework is required to fully expose and account for the complexity of sociocultural and environmental effects. The authors have generated a diagnostic tool for this use. The paper then provides a detailed demonstration of the potential power of the tool by applying it to three illustrative case studies: one on encouraging safer driving, the second promoting sustainable travel, and the third increasing early detection of lung cancer. Ā© 2010 Westburn Publishers Ltd
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