212 resultados para Porter, Jeff


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We present the results of a Monte Carlo technique to calculate the absolute magnitudes (H) and slope parameters (G) of about 240,000 asteroids observed by the Pan-STARRS1 telescope during the first 15 months of its 3-year all-sky survey mission. The system's exquisite photometry with photometric errors asteroids rotation period, amplitude and color to derive the most-likely H and G, but its major advantage is in estimating realistic statistical+systematic uncertainties and errors on each parameter. The method was confirmed by comparison with the well-established and accurate results for about 500 asteroids provided by Pravec et al. (2012) and then applied to determining H and G for the Pan-STARRS1 asteroids using both the Muinonen et al. (2010) and Bowell et al. (1989) phase functions. Our results confirm the bias in MPC photometry discovered by ( Jurić et al., 2002).

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Background: Multidimensional rehabilitation programmes (MDRPs) have developed in response to the growing number of people living with and surviving cancer. MDRPs comprise a physical component and a psychosocial component. Studies of the effectiveness of these programmes have not been reviewed and synthesised.

Objectives: To conduct a systematic review of studies examining the effectiveness of MDRPs in terms of maintaining or improving the physical and psychosocial well-being of adult cancer survivors.

Search methods: We conducted electronic searches in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL and PsychINFO up to February 2012.

Selection criteria: Selection criteria focused on randomised controlled trials (RCTs) of multidimensional interventions for adult cancer survivors. Interventions had to include a physical component and a psychosocial component and to have been carried out on two or more occasions following completion of primary cancer treatment. Outcomes had to be assessed using validated measures of physical health and psychosocial well-being. Non-English language papers were included.

Data collection and analysis: Pairs of review authors independently selected trials, rated their methodological quality and extracted relevant data. Although meta-analyses of primary and secondary endpoints were planned there was a high level of study heterogeneity and only one common outcome measure (SF-36) could be statistically synthesised. In addition, we conducted a narrative analysis of interventions, particularly in terms of inspecting and identifying intervention components, grouping or categorising interventions and examining potential common links and outcomes.

Main results: Twelve RCTs (comprising 1669 participants) met the eligibility criteria. We judged five studies to have a moderate risk of bias and assessed the remaining seven as having a high risk of bias. It was possible to include SF-36 physical health component scores from five studies in a meta-analysis. Participating in a MDRP was associated with an increase in SF-36 physical health component scores (mean difference (MD) 2.22, 95% confidence interval (CI) 0.12 to 4.31, P = 0.04). The findings from the narrative analysis suggested that MDRPs with a single domain or outcome focus appeared to be more successful than programmes with multiple aims. In addition, programmes that comprised participants with different types of cancer compared to cancer site-specific programmes were more likely to show positive improvements in physical outcomes. The most effective mode of service delivery appeared to be face-to-face contact supplemented with at least one follow-up telephone call. There was no evidence to indicate that MDRPs which lasted longer than six months improved outcomes beyond the level attained at six months. In addition, there was no evidence to suggest that services were more effective if they were delivered by a particular type of health professional.

Authors' conclusions: There is some evidence to support the effectiveness of brief, focused MDRPs for cancer survivors. Rigorous and methodologically sound clinical trials that include an economic analysis are required.

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Objectives We aimed to describe administration of eight potentially harmful excipients of interest (EOI)-parabens, polysorbate 80, propylene glycol, benzoates, saccharin sodium, sorbitol, ethanol and benzalkonium chloride-to hospitalised neonates in Europe and to identify risk factors for exposure. Methods All medicines administered to neonates during 1 day with individual prescription and demographic data were registered in a web-based point prevalence study. Excipients were identified from the Summaries of Product Characteristics. Determinants of EOI administration (geographical region, gestational age (GA), active pharmaceutical ingredient, unit level and hospital teaching status) were identified using multivariable logistical regression analysis. Results Overall 89 neonatal units from 21 countries participated. Altogether 2095 prescriptions for 530 products administered to 726 neonates were recorded. EOI were found in 638 (31%) prescriptions and were administered to 456 (63%) neonates through a relatively small number of products (n=142; 27%). Parabens, found in 71 (13%) products administered to 313 (43%) neonates, were used most frequently. EOI administration varied by geographical region, GA and route of administration. Geographical region remained a significant determinant of the use of parabens, polysorbate 80, propylene glycol and saccharin sodium after adjustment for the potential covariates including anatomical therapeutic chemical class of the active ingredient. Conclusions European neonates receive a number of potentially harmful pharmaceutical excipients. Regional differences in EOI administration suggest that EOI-free products are available and provide the potential for substitution to avoid side effects of some excipients.

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Microbial communities are enigmatically diverse. We propose a novel view of processes likely affecting microbial assemblages, which could be viewed as the Great American Interchange en miniature: the wholesale exchange among microbial communities resulting from moving pieces of the environment containing entire assemblages. Incidental evidence for such ‘community coalescence’ is accumulating, but such processes are rarely studied, likely because of the absence of suitable terminology or a conceptual framework. We provide the nucleus for such a conceptual foundation for the study of community coalescence, examining factors shaping these events, links to bodies of ecological theory, and we suggest modeling approaches for understanding coalescent communities. We argue for the systematic study of community coalescence because of important functional and applied consequences.

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Invited keynote presentation

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Invited annual international lecture

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Invited presentation

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This paper critically analyses realist evaluation, focussing on its primary analytical concepts: mechanisms, contexts, and outcomes. Noting that nursing investigators have had difficulty in operationalizing the concepts of mechanism and context, it is argued that their confusion is at least partially the result of ambiguities, inconsistencies, and contradictions in the realist evaluation model. Problematic issues include the adoption of empiricist and idealist positions, oscillation between determinism and voluntarism, subsumption of agency under structure, and categorical confusion between context and mechanism. In relation to outcomes, it is argued that realist evaluation's adoption of the fact/value distinction prevents it from taking into account the concerns of those affected by interventions. The aim of the paper is to use these immanent critiques of realist evaluation to construct an internally consistent realist approach to evaluation that is more amenable to being operationalized by nursing researchers.

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Purpose: As resident work hours policies evolve, residents’ off-duty time remains poorly understood. Despite assumptions about how residents should be using their postcall, off-duty time, there is little research on how residents actually use this time and the reasoning underpinning their activities. This study sought to understand residents’ nonclinical postcall activities when they leave the hospital, their decision-making processes, and their perspectives on the relationship between these activities and their well-being or recovery.

Method: The study took place at a Liaison Committee on Medical Education–accredited Canadian medical school from 2012 to 2014. The authors recruited a purposive and convenience sample of postgraduate year 1–5 residents from six surgical and nonsurgical specialties at three hospitals affiliated with the medical school. Using a constructivist grounded theory approach, semistructured interviews were conducted, audio-taped, transcribed, anonymized, and combined with field notes. The authors analyzed interview transcripts using constant comparative analysis and performed post hoc member checking.

Results: Twenty-four residents participated. Residents characterized their predominant approach to postcall decision making as one of making trade-offs between multiple, competing, seemingly incompatible, but equally valuable, activities. Participants exhibited two different trade-off orientations: being oriented toward maintaining a normal life or toward mitigating fatigue.

Conclusions: The authors’ findings on residents’ trade-off orientations suggest a dual recovery model with postcall trade-offs motivated by the recovery of sleep or of self. This model challenges the dominant viewpoint in the current duty hours literature and suggests that the duty hours discussion must be broadened to include other recovery processes.

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One of the challenges the tidal power industry faces, is the requirement of cost effective, reliable but highly accurate acquisition of flow data. Different methods are required , applications range over different spatial and temporal scales. This report assembles in the first sections, theoretical background information on acoustic Doppler Velocimetry and RADAR measurements. The use of existing expertise in field tests of marine vehicles is discussed next, followed by a discussion of issues relating to recreating field conditions in laboratory environments. The last three sections present practical applications of various methods performed in field conditions. While progress has been made over the last years, this overview highlights the challenges in full scale field measurements and knowledge gaps in the industry.

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Background: Rapid Response Systems (RRS) have been implemented nationally and internationally to improve patient safety in hospital. However, to date the majority of the RRS research evidence has focused on measuring the effectiveness of the intervention on patient outcomes. To evaluate RRS it has been recommended that a multimodal approach is required to address the broad range of process and outcome measures required to determine the effectiveness of the RRS concept. Aim: The aim of this paper is to evaluate the official RRS programme theoretical assumptions regarding how the programme is meant to work against actual practice in order to determine what works. Methods: The research design was a multiple case study approach of four wards in two hospitals in Northern Ireland. It followed the principles of realist evaluation research which allowed empirical data to be gathered to test and refine RRS programme theory [1]. This approach used a variety of mixed methods to test the programme theories including individual and focus group interviews with a purposive sample of 75 nurses and doctors, observation of ward practices and documentary analysis. The findings from the case studies were analysed and compared within and across cases to identify what works for whom and in what circumstances. Results: The RRS programme theories were critically evaluated and compared with study findings to develop a mid-range theory to explain what works, for whom in what circumstances. The findings of what works suggests that clinical experience, established working relationships, flexible implementation of protocols, ongoing experiential learning, empowerment and pre-emptive management are key to the success of RRS implementation.  Conclusion:These findings highlight the combination of factors that can improve the implementation of RRS and in light of this evidence several recommendations are made to provide policymakers with guidance and direction for their success and sustainability.References: 1.Pawson R and Tilley N. (1997) Realistic Evaluation. Sage Publications; LondonType of submission: Concurrent session Source of funding: Sandra Ryan Fellowship funded by the School of Nursing & Midwifery, Queen’s University of Belfast

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Realistic Evaluation of EWS and ALERT: factors enabling and constraining implementation Background The implementation of EWS and ALERT in practice is essential to the success of Rapid Response Systems but is dependent upon nurses utilising EWS protocols and applying ALERT best practice guidelines. To date there is limited evidence on the effectiveness of EWS or ALERT as research has primarily focused on measuring patient outcomes (cardiac arrests, ICU admissions) following the implementation of a Rapid Response Team. Complex interventions in healthcare aimed at changing service delivery and related behaviour of health professionals require a different research approach to evaluate the evidence. To understand how and why EWS and ALERT work, or might not work, research needs to consider the social, cultural and organisational influences that will impact on successful implementation in practice. This requires a research approach that considers both the processes and outcomes of complex interventions, such as EWS and ALERT, implemented in practice. Realistic Evaluation is such an approach and was used to explain the factors that enable and constrain the implementation of EWS and ALERT in practice [1]. Aim The aim of this study was to evaluate factors that enabled and constrained the implementation and service delivery of early warnings systems (EWS) and ALERT in practice in order to provide direction for enabling their success and sustainability. Methods The research design was a multiple case study approach of four wards in two hospitals in Northern Ireland. It followed the principles of realist evaluation research which allowed empirical data to be gathered to test and refine RRS programme theory. This approach used a variety of mixed methods to test the programme theories including individual and focus group interviews, observation and documentary analysis in a two stage process. A purposive sample of 75 key informants participated in individual and focus group interviews. Observation and documentary analysis of EWS compliance data and ALERT training records provided further evidence to support or refute the interview findings. Data was analysed using NVIVO8 to categorise interview findings and SPSS for ALERT documentary data. These findings were further synthesised by undertaking a within and cross case comparison to explain the factors enabling and constraining EWS and ALERT. Results A cross case analysis highlighted similarities, differences and factors enabling or constraining successful implementation across the case study sites. Findings showed that personal (confidence; clinical judgement; personality), social (ward leadership; communication), organisational (workload and staffing issues; pressure from managers to complete EWS audit and targets), educational (constraints on training; no clinical educator on ward) and cultural (routine task delegated) influences impact on EWS and acute care training outcomes. There were also differences noted between medical and surgical wards across both case sites. Conclusions Realist Evaluation allows refinement and development of the RRS programme theory to explain the realities of practice. These refined RRS programme theories are capable of informing the planning of future service provision and provide direction for enabling their success and sustainability. References: 1. McGaughey J, Blackwood B, O’Halloran P, Trinder T. J. & Porter S. (2010) A realistic evaluation of Track and Trigger systems and acute care training for early recognition and management of deteriorating ward–based patients. Journal of Advanced Nursing 66 (4), 923-932. Type of submission: Concurrent session Source of funding: Sandra Ryan Fellowship funded by the School of Nursing & Midwifery, Queen’s University of Belfast

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Background Rapid Response Systems (RRS) consist of four interrelated and interdependent components; an event detection and trigger mechanism, a response strategy, a governance structure and process improvement system. These multiple components of the RRS pose problems in evaluation as the intervention is complex and cannot be evaluated using a traditional systematic review. Complex interventions in healthcare aimed at changing service delivery and related behaviour of health professionals require a different approach to summarising the evidence. Realist synthesis is such an approach to reviewing research evidence on complex interventions to provide an explanatory analysis of how and why an intervention works or doesn’t work in practice. The core principle is to make explicit the underlying assumptions about how an intervention is suppose to work (ie programme theory) and then use this theory to guide evaluation. Methods A realist synthesis process was used to explain those factors that enable or constrain the success of RRS programmes. Results The findings from the review include the articulation of the RRS programme theories, evaluation of whether these theories are supported or refuted by the research evidence and an evaluation of evidence to explain the underlying reasons why RRS works or doesn’t work in practice. Rival conjectured RRS programme theories were identified to explain the constraining factors regarding implementation of RRS in practice. These programme theories are presented using a logic model to highlight all the components which impact or influence the delivery of RRS programmes in the practice setting. The evidence from the realist synthesis provided the foundation for the development of hypothesis to test and refine the theories in the subsequent stages of the Realist Evaluation PhD study [1]. This information will be useful in providing evidence and direction for strategic and service planning of acute care to improve patient safety in hospital. References: McGaughey J, Blackwood B, O’Halloran P, Trinder T. J. & Porter S. (2010) Realistic Evaluation of Early Warning Systems and the Acute Life-threatening Events – Recognition and Treatment training course for early recognition and management of deteriorating ward-based patients: research protocol. Journal of Advanced Nursing 66 (4), 923-932.