1,149 research outputs found

    Development and validation of the ACE tool: Assessing medical trainees' competency in evidence based medicine

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    BACKGROUND: While a variety of instruments have been developed to assess knowledge and skills in evidence based medicine (EBM), few assess all aspects of EBM - including knowledge, skills attitudes and behaviour - or have been psychometrically evaluated. The aim of this study was to develop and validate an instrument that evaluates medical trainees’ competency in EBM across knowledge, skills and attitude. METHODS: The ‘Assessing Competency in EBM’ (ACE) tool was developed by the authors, with content and face validity assessed by expert opinion. A cross-sectional sample of 342 medical trainees representing ‘novice’, ‘intermediate’ and ‘advanced’ EBM trainees were recruited to complete the ACE tool. Construct validity, item difficulty, internal reliability and item discrimination were analysed. RESULTS: We recruited 98 EBM-novice, 108 EBM-intermediate and 136 EBM-advanced participants. A statistically significant difference in the total ACE score was observed and corresponded to the level of training: on a 0-15-point test, the mean ACE scores were 8.6 for EBM-novice; 9.5 for EBM-intermediate; and 10.4 for EBM-advanced (p < 0.0001). Individual item discrimination was excellent (Item Discrimination Index ranging from 0.37 to 0.84), with internal reliability consistent across all but three items (Item Total Correlations were all positive ranging from 0.14 to 0.20). CONCLUSION: The 15-item ACE tool is a reliable and valid instrument to assess medical trainees’ competency in EBM. The ACE tool provides a novel assessment that measures user performance across the four main steps of EBM. To provide a complete suite of instruments to assess EBM competency across various patient scenarios, future refinement of the ACE instrument should include further scenarios across harm, diagnosis and prognosis

    The Micro-Orifice Uniform Deposit Impactor–Droplet Freezing Technique (MOUDI-DFT) for Measuring Concentrations of Ice Nucleating Particles as a Function of Size: Improvements and Initial Validation

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    The micro-orifice uniform deposit impactor– droplet freezing technique (MOUDI-DFT) combines particle collection by inertial impaction (via the MOUDI) and a microscope-based immersion freezing apparatus (the DFT) to measure atmospheric concentrations of ice nucleating particles (INPs) as a function of size and temperature. In the first part of this study we improved upon this recently introduced technique. Using optical microscopy, we investigated the non-uniformity of MOUDI aerosol deposits at spatial resolutions of 1, 0.25 mm, and for some stages when necessary 0.10 mm. The results from these measurements show that at a spatial resolution of 1mm and less, the concentration of particles along the MOUDI aerosol deposits can vary by an order of magnitude or more. Since the total area of a MOUDI aerosol deposit ranges from 425 to 605mm2 and the area analyzed by the DFT is approximately 1.2mm2, this non-uniformity needs to be taken into account when using the MOUDI-DFT to determine atmospheric concentrations of INPs. Measurements of the non-uniformity of the MOUDI aerosol deposits were used to select positions on the deposits that had relatively small variations in particle concentration and to build substrate holders for the different MOUDI stages. These substrate holders improve reproducibility by holding the substrate in the same location for each measurement and ensure that DFT analysis is only performed on substrate regions with relatively small variations in particle concentration. In addition, the deposit non-uniformity was used to determine correction factors that take the non-uniformity into account when determining atmospheric concentrations of INPs. In the second part of this study, the MOUDI-DFT utilizing the new substrate holders was compared to the continuous flow diffusion chamber (CFDC) technique of Colorado State University. The intercomparison was done using INP concentrations found by the two instruments during ambient measurements of continental aerosols. Results from two sampling periods were compared, and the INP concentrations determined by the two techniques agreed within experimental uncertainty. The agreement observed here is commensurate with the level of agreement found in other studies where CFDC results were compared to INP concentrations measured with other methods

    Early careers on ecohydraulics:Challenges, opportunities and future directions

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    Early career researchers (ECRs) play a critical role in our knowledge-based society, yet they are the most vulnerable group in the scientific community. As a young, interdisciplinary science, ecohydraulics is particularly reliant on ECRs for future progress. In 2014, the Early Careers on Ecohydraulics Network (ECoENet) was created to help the development of young researchers in this field. In this paper, we synthesize the outcomes of a workshop for ECRs organized by ECoENet in February 2016. We aim to show how the potential of ECRs can be maximized to drive progress in ecohydraulics. According to the most recent entrants to the field, major challenges lie in becoming more integrated as a discipline, developing a common vocabulary and a collective vision, engaging effectively with policy-makers, and encouraging public participation. ECRs need to develop their careers on an international scale in a way that crosses traditional disciplinary boundaries, including the social sciences, and allows them time to work at fundamental levels rather than focusing solely on individual applications. We propose a strategy to facilitate this by providing: a platform for disseminating research; an international support network; and a set of services for enhancing ECR training and experience. Early career researchers; interdisciplinary science; ecohydraulics; society; ecology; hydraulicsacceptedVersio

    Ice-nucleating particle emissions from biomass combustion and the potential importance of soot aerosol

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    Ice-nucleating particles (INPs) are required for initial ice crystal formation in clouds at temperatures warmer than about -36°C and thus play a crucial role in cloud and precipitation formation. Biomass burning has been found to be a source of INPs in previous studies and is also a major contributor to atmospheric black carbon (BC) concentrations. This study focuses on isolating the BC contribution to the INP population associated with biomass combustion. Emissions of condensation mode INPs from a number of globally relevant biomass fuels were measured at -30°C and above water saturation as fires progressed from ignition to extinguishment in a laboratory setting. Number emissions of INPs were found to be highest during intense flaming combustion (modified combustion efficiency\u3e0.95). Overall, combustion emissions from 13 of 22 different biomass fuel types produced measurable INP concentrations for at least one replicate experiment. On average, all burns that produced measureable INPs had higher combustion efficiency, which is associated with higher BC emissions, than those that did not produce measureable INPs. Across all burns that produced measureable INPs, concentrations ranged from 0.1 to 10 cm-3, and the median emission factor was about 2 × 107 INPs per kilogram of fuel burned. For a subset of the burns, the contribution of refractory black carbon (rBC) to INP concentrations was determined by removing rBC via laser-induced incandescence. Reductions in INPs of 0-70% were observed, indicating an important contribution of rBC particles to INP concentrations for some burns, especially marsh grasses

    Evidence-based practice educational intervention studies: A systematic review of what is taught and how it is measured

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    Abstract Background Despite the established interest in evidence-based practice (EBP) as a core competence for clinicians, evidence for how best to teach and evaluate EBP remains weak. We sought to systematically assess coverage of the five EBP steps, review the outcome domains measured, and assess the properties of the instruments used in studies evaluating EBP educational interventions. Methods We conducted a systematic review of controlled studies (i.e. studies with a separate control group) which had investigated the effect of EBP educational interventions. We used citation analysis technique and tracked the forward and backward citations of the index articles (i.e. the systematic reviews and primary studies included in an overview of the effect of EBP teaching) using Web of Science until May 2017. We extracted information on intervention content (grouped into the five EBP steps), and the outcome domains assessed. We also searched the literature for published reliability and validity data of the EBP instruments used. Results Of 1831 records identified, 302 full-text articles were screened, and 85 included. Of these, 46 (54%) studies were randomised trials, 51 (60%) included postgraduate level participants, and 63 (75%) taught medical professionals. EBP Step 3 (critical appraisal) was the most frequently taught step (63 studies; 74%). Only 10 (12%) of the studies taught content which addressed all five EBP steps. Of the 85 studies, 52 (61%) evaluated EBP skills, 39 (46%) knowledge, 35 (41%) attitudes, 19 (22%) behaviours, 15 (18%) self-efficacy, and 7 (8%) measured reactions to EBP teaching delivery. Of the 24 instruments used in the included studies, 6 were high-quality (achieved ≄3 types of established validity evidence) and these were used in 14 (29%) of the 52 studies that measured EBP skills; 14 (41%) of the 39 studies that measured EBP knowledge; and 8 (26%) of the 35 studies that measured EBP attitude. Conclusions Most EBP educational interventions which have been evaluated in controlled studies focus on teaching only some of the EBP steps (predominantly critically appraisal of evidence) and did not use high-quality instruments to measure outcomes. Educational packages and instruments which address all EBP steps are needed to improve EBP teaching

    Ferromagnetism in Ga1-xMnxP: evidence for inter-Mn exchange mediated by localized holes within a detached impurity band

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    We demonstrate that in ferromagnetic Ga1-xMnxP exchange is mediated by holes localized in a Mn-derived band. For x<0.06, infrared absorption and photoconductivity spectra indicate the presence of a Mn impurity band which is not merged with the valence band. At temperatures above TC (<65 K) electrical transport is dominated by excitation across this energy gap while nearest neighbor hopping dominates below TC. Magnetization measurements reveal a moment of 3.5 Bohr magnetons per substitutional Mn, while the large anomalous Hall signal unambiguously demonstrates that the ferromagnetism is carrier-mediated.Comment: Equation 1 correcte

    Distribution of T cell subsets in human lymph nodes.

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