256 research outputs found

    Local log-law of the wall: numerical evidences and reasons

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    Numerical studies performed with a primitive equation model on two-dimensional sinusoidal hills show that the local velocity profiles behave logarithmically to a very good approximation, from a distance from the surface of the order of the maximum hill height almost up to the top of the boundary layer. This behavior is well known for flows above homogeneous and flat topographies (``law-of-the-wall'') and, more recently, investigated with respect to the large-scale (``asymptotic'') averaged flows above complex topography. Furthermore, this new-found local generalized law-of-the-wall involves effective parameters showing a smooth dependence on the position along the underlying topography. This dependence is similar to the topography itself, while this property does not absolutely hold for the underlying flow, nearest to the hill surface.Comment: 9 pages, Latex, 2 figure

    Psychometric properties of the Hospital Survey on Patient Safety Culture: findings from the UK

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    Background: Patient safety culture is measured using a range of survey tools. Many provide limited data on psychometric properties and few report findings outside of the USA healthcare context. This study reports an assessment of the psychometric properties and suitability of the American Hospital Survey on Patient Safety Culture (HSOPC) for use within the UK. Methods: A questionnaire survey of three hospitals within a large UK Acute NHS Trust. 1,437 questionnaires were completed (37% response rate). Exploratory factor analysis, confirmatory factor analysis, and reliability analyses were carried out to assess the psychometric performance of this survey instrument and explore potential improvements. Results: Reliability analysis of the items within each proposed scale showed that over half failed to achieve satisfactory internal consistency (Cronbach’s Alpha < 0.7). Furthermore, a confirmatory factor analysis carried out on the UK dataset achieved a poor fit when compared to the original American model. An optimal measurement model was then constructed via exploratory and confirmatory factor analysis with split-half sample validation, and consisted of 9 dimensions compared to the original 12 in the American model. Conclusion: This is one of the few studies to provide an evaluation of an American patient safety culture survey using data from the UK. The results indicate that there is need for caution in using the HSOPC survey in the UK and underline the importance of appropriate validation of safety culture surveys before extending their usage to populations outside of the specific geographical and health care contexts in which they were developed

    Patient safety in dentistry: development of a candidate 'never event' list for primary care

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    Introduction The 'never event' concept is often used in secondary care and refers to an agreed list of patient safety incidents that 'should not happen if the necessary preventative measures are in place'. Such an intervention may raise awareness of patient safety issues and inform team learning and system improvements in primary care dentistry. Objective To identify and develop a candidate never event list for primary care dentistry. Methods A literature review, eight workshops with dental practitioners and a modified Delphi with 'expert' groups were used to identify and agree candidate never events. Results Two-hundred and fifty dental practitioners suggested 507 never events, reduced to 27 distinct possibilities grouped across seven themes. Most frequently occurring themes were: 'checking medical history and prescribing' (119, 23.5%) and 'infection control and decontamination' (71, 14%). 'Experts' endorsed nine candidate never event statements with one graded as 'extreme risk' (failure to check past medical history) and four as 'high risk' (for example, extracting wrong tooth). Conclusion Consensus on a preliminary list of never events was developed. This is the first known attempt to develop this approach and an important step in determining its value to patient safety. Further work is necessary to develop the utility of this method

    A study on job postures and musculoskeletal illnesses in dentists

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    Objectives: Musculoskeletal disorders (MSDs) compose a large part of occupational diseases in dental professionals, prevention of which is dependent on assessment and improvement of job postures by means of ergonomic interventions. This study was aimed at evaluation of ergonomic conditions of the profession of dentists and also at assessing the relationship between MSDs and conditions of work. Materials and Methods: This cross-sectional study was performed among 65 dentists using the method of Rapid Entire Body Assessment (REBA). The prevalence of MSDs was obtained by the use of the Nordic Musculoskeletal Questionnaire (NMQ). Results: In this investigation, the prevalence of MSDs for different body parts was: 75.9% for the neck, 58.6% for the shoulders, 56.9% for the upper back, 48.3% for the lower back and 44.8% for the wrist. Job analysis by the use of REBA showed that 89.6% of limbs in group A and 79.3% of limbs in group B had a score > 4. Only neck and lower back pain have significant relationship with the risk levels obtained using the REBA method. Conclusions: It can be concluded that work postures of dentists need to be improved. In addition to education, work station design, rest period during work and regular physical activities should be taken into account

    Applying human factors methods to explore ‘Work as Imagined’ and ‘Work as Done’ in the Emergency Department’s response to chemical, biological, radiological, and nuclear events

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    The Emergency Department (ED) is a complex, hectic, and high-pressured environment. Chemical, Biological, Radiological, and Nuclear (CBRN) events are multi-faceted emergencies and present numerous challenges to ED staff (first receivers) with large scale trauma, consequently requiring a combination of complex responses. Human Factors and Ergonomics (HF/E) methods such as Hierarchical Task Analysis (HTA) have been used in healthcare research. However, HF/E methods and theory have not been combined to understand how the ED responds to CBRN events. This study aimed to compare Work as Imagined (WAI) and Work as Done (WAD) in the ED CBRN response in a UK based hospital. WAI was established by carrying out document analyses on a CBRN plan and WAD by exploring first receivers response to CBRN scenario cards. The responses were converted to HTAs and compared. The WAI HTAs showed 4-8 phases of general organizational responsibilities during a CBRN event. WAD HTAs placed emphasis on diagnosing and treating presenting conditions. A comparison of WAI and WAD HTAs highlighted common actions and tasks. This study has identified three key differences between WAI and WAD in the ED CBRN response: 1) documentation of the CBRN event 2) treating the patient and 3) diagnosing the presenting complaint. Findings from this study provide an evidence base which can be used to inform future clinical policy and practice in providing safe and high quality care during CBRN events in the ED

    Human factors for dementia: Evidence based design

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    Designing care environments for people living with dementia is a complex challenge as the key stakeholder may have difficulty communicating their capabilities, limitations and preferences. This paper describes the use of evidence-based design personas in a multi-disciplinary team with architects and chartered human factors specialists. Four individual personas (Alison, Barry, Christine and David) and a couple persona (Chris and Sally) were used to bring the voices of the people living with different stages of dementia to the design process. Their changing/fluctuating symptoms were communicated in two formats (wheel and matrix) within an inclusive design process to adapt a Victorian semi-detached house. The demonstrator house presents evidence based design, adaptation and support solutions to support people living with dementia to age well at home

    A cross-sector analysis of human and organisational factors in the deployment of data-driven predictive maintenance

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    Domains such as utilities, power generation, manufacturing and transport are increasingly turning to data-driven tools for management and maintenance of key assets. Whole ecosystems of sensors and analytical tools can provide complex, predictive views of network asset performance. Much research in this area has looked at the technology to provide both sensing and analysis tools. The reality in the field, however, is that the deployment of these technologies can be problematic due to user issues, such as interpretation of data or embedding within processes, and organisational issues, such as business change to gain value from asset analysis. 13 experts from the field of remote condition monitoring, asset management and predictive analytics across multiple sectors were interviewed to ascertain their experience of supplying data-driven applications. The results of these interviews are summarised as a framework based on a predictive maintenance project lifecycle covering project motivations and conception, design and development, and operation. These results identified critical themes for success around having a target or decision-led, rather than data-led, approach to design; long-term resourcing of the deployment; the complexity of supply chains to provide data-driven solutions and the need to maintain knowledge across the supply chain; the importance of fostering technical competency in end-user organisations; and the importance of a maintenance-driven strategy in the deployment of data-driven asset management. Emerging from these themes are recommendations related to culture, delivery process, resourcing, supply chain collaboration and industry-wide cooperation

    Aerosol Characteristics at a High Altitude Location in Central Himalayas: Optical Properties and Radiative Forcing

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    Collocated measurements of the mass concentrations of aerosol black carbon (BC) and composite aerosols near the surface were carried out along with spectral aerosol optical depths (AODs) from a high altitude station, Manora Peak in Central Himalayas, during a comprehensive aerosol field campaign in December 2004. Despite being a pristine location in the Shivalik Ranges of Central Himalayas, and having a monthly mean AOD (at 500 nm) of 0.059 ±\pm 0.033 (typical to this site), total suspended particulate (TSP) concentration was in the range 15 - 40 micro g m^(-3) (mean value 27.1 ±\pm 8.3 micro g m^(-3)). Interestingly, aerosol BC had a mean concentration of 1.36 ±\pm 0.99 micro g m^(-3), contributed to ~5.0 ±\pm 1.3 % to the composite aerosol mass. This large abundance of BC is found to have linkages to the human activities in the adjoining valley and to the boundary layer dynamics. Consequently, the inferred single scattering albedo lies in the range of 0.87 to 0.94 (mean value 0.90 ±\pm 0.03), indicating significant aerosol absorption. The estimated aerosol radiative forcing was as low as 4.2 W m^(-2) at the surface, +0.7 W m^(-2) at the top of the atmosphere, implying an atmospheric forcing of +4.9 W m^(-2). Though absolute value of the atmospheric forcing is quite small, which arises primarily from the very low AOD (or the column abundance of aerosols), the forcing efficiency (forcing per unit optical depth) was ∼\sim88 W m^(-2), which is attributed to the high BC mass fraction.Comment: 32 Pages, Accepted in JGR (Atmosphere

    Variation in the provision and practice of implant-based breast reconstruction in the UK: Results from the iBRA national practice questionnaire

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    Introduction The introduction of biological and synthetic meshes has revolutionised the practice of implant-based breast reconstruction (IBBR) but evidence for effectiveness is lacking. The iBRA (implant Breast Reconstruction evAluation) study is a national trainee-led project that aims to explore the practice and outcomes of IBBR to inform the design of a future trial. We report the results of the iBRA National Practice Questionnaire (NPQ) which aimed to comprehensively describe the provision and practice of IBBR across the UK. Methods A questionnaire investigating local practice and service provision of IBBR developed by the iBRA Steering Group was completed by trainee and consultant leads at breast and plastic surgical units across the UK. Summary data for each survey item were calculated and variation between centres and overall provision of care examined. Results 81 units within 79 NHS-hospitals completed the questionnaire. Units offered a range of reconstructive techniques, with IBBR accounting for 70% (IQR:50–80%) of participating units' immediate procedures. Units on average were staffed by 2.5 breast surgeons (IQR:2.0–3.0) and 2.0 plastic surgeons (IQR:1.0–3.0) performing 35 IBBR cases per year (IQR:20-50). Variation was demonstrated in the provision of novel different techniques for IBBR especially the use of biological (n = 62) and synthetic (n = 25) meshes and in patient selection for these procedures. Conclusions The iBRA-NPQ has demonstrated marked variation in the provision and practice of IBBR in the UK. The prospective audit phase of the iBRA study will determine the safety and effectiveness of different approaches to IBBR and allow evidence-based best practice to be explored
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