41 research outputs found

    Ultrafast Electric Field-induced Phase Transition in Bulk Bi0.5Na0.5TiO3 under High Intensity Terahertz Irradiation

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    “This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acsphotonics.0c01559”Ultrafast polarization switching is being considered for the next generation of ferroelectric based devices. Recently, the dynamics of the field-induced transitions associated with this switching have been difficult to explore, due to technological limitations. The advent of terahertz (THz) technology has now allowed for the study of these dynamic processes on the picosecond (ps) scale. In this paper, intense terahertz (THz) pulses were used as a high-frequency electric field to investigate ultrafast switching in the relaxor ferroelectric, Bi0.5Na0.5TiO3. Transient atomic-scale responses, which were evident as changes in reflectivity, were captured by THz probing. The high energy THz pulses induce an increase in reflectivity, associated with an ultrafast field-induced phase transition from a weakly polar phase (Cc) to a strongly polar phase (R3c) within 20 ps at 200 K. This phase transition was confirmed using X-ray powder diffraction and by electrical measurements which showed a decrease in the frequency dispersion of relative permittivity at low frequencies

    Non-traumatic Arm, Neck, and Shoulder Complaints in General Practice: Incidence, Course and Management

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    Non-traumatic complaints of arm, neck, and shoulder are common and can result in functional limitations in daily life and may sometimes lead to sickness absence. Reported symptoms are e.g. pain, tingling, stiffness, numbness, loss of hand coordination. When seeking medical care for these complaints, the general practitioner (GP) is usually the first person to consult. This thesis studies patients who consult their GP with a new non-traumatic complaint of arm, neck or shoulder, with a focus on incidence, course and management. The incidence study showed that a fulltime GP is consulted about 3 times every week for a new non-traumatic complaint of arm, neck, or shoulder, most frequently located at neck or shoulder. Six months after the first consultation with their GP, 46% of the patients in the cohort study reported no recovery. Next to several complaint specific variables, the psychosocial variables little social support and high score on somatization were predicitve of non-recovery at 6 months. Management upto 6 months after the first consultation most frequently consisted of prescribed analgesics and referral for physiotherapy. Specific and non-specific diagnostic subgroups differed in the frequency that corticosteroid injections were applied, and referrals to physiotherapy and to a medical specialist. In addition variables associated with five common management options within a few weeks after the first consultation were evaluated. Overall, besides diagnosis, most frequently long duration of complaints, more functional limitations but also several GP characteristics were associated with the application of a treatment option in non-traumatic arm, neck and shoulder complaints

    The “ebb and flow” of student learning on placement

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    There is a rise in interest in work based learning as part of student choice at subject level in the UK (DOE 2017) but there remains an absence of specific guidance on how to best support higher education students learning on placement. An alternative HE experience in England, the degree apprenticeship, underlies the continued focus by policy in securing placement experiences for students without stipulating the type of support that is required at the ‘coal face’ of work based learning. Policy documents (UUK 2016), that urge universities to enter into partnership agreements with both employers and FE colleges to plug skills shortages, are noticeably lacking in their appreciation of the unique qualities of work based learning and how best to support students in this setting (Morley 2017a). Unfortunately, this is not unusual as placements have predominantly been an enriching ‘add on’ to the real business of academic learning in more traditional university programmes. Support initiatives, such as that described in chapter 9, are a rare appreciation of the importance of this role. Undergraduate nursing programmes currently support a 50:50 split between practice learning in clinical placements and the theory delivered at universities. Vocational degrees, such as this, provide an interesting case study as to how students can be supported in the practice environment by an appreciation of how students really learn on placement and how hidden resources can be utilised more explicitly for practice learning. During 2013 – 2015 a professional doctorate research study (Morley 2015) conducted a grounded theory study of 21 first year student nurses on their first placement to discover how they learnt ‘at work’ and the strategies they enlisted to be successful work based learners

    Use of communities of practice in business and health care sectors: A systematic review

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    <p>Abstract</p> <p>Background</p> <p>Since being identified as a concept for understanding knowledge sharing, management, and creation, communities of practice (CoPs) have become increasingly popular within the health sector. The CoP concept has been used in the business sector for over 20 years, but the use of CoPs in the health sector has been limited in comparison.</p> <p>Objectives</p> <p>First, we examined how CoPs were defined and used in these two sectors. Second, we evaluated the evidence of effectiveness on the health sector CoPs for improving the uptake of best practices and mentoring new practitioners.</p> <p>Methods</p> <p>We conducted a search of electronic databases in the business, health, and education sectors, and a hand search of key journals for primary studies on CoP groups. Our research synthesis for the first objective focused on three areas: the authors' interpretations of the CoP concept, the key characteristics of CoP groups, and the common elements of CoP groups. To examine the evidence on the effectiveness of CoPs in the health sector, we identified articles that evaluated CoPs for improving health professional performance, health care organizational performance, professional mentoring, and/or patient outcome; and used experimental, quasi-experimental, or observational designs.</p> <p>Results</p> <p>The structure of CoP groups varied greatly, ranging from voluntary informal networks to work-supported formal education sessions, and from apprentice training to multidisciplinary, multi-site project teams. Four characteristics were identified from CoP groups: social interaction among members, knowledge sharing, knowledge creation, and identity building; however, these were not consistently present in all CoPs. There was also a lack of clarity in the responsibilities of CoP facilitators and how power dynamics should be handled within a CoP group. We did not find any paper in the health sector that met the eligibility criteria for the quantitative analysis, and so the effectiveness of CoP in this sector remained unclear.</p> <p>Conclusion</p> <p>There is no dominant trend in how the CoP concept is operationalized in the business and health sectors; hence, it is challenging to define the parameters of CoP groups. This may be one of the reasons for the lack of studies on the effectiveness of CoPs in the health sector. In order to improve the usefulness of the CoP concept in the development of groups and teams, further research will be needed to clarify the extent to which the four characteristics of CoPs are present in the mature and emergent groups, the expectations of facilitators and other participants, and the power relationship within CoPs.</p

    Reduction of claustrophobia during magnetic resonance imaging: methods and design of the "CLAUSTRO" randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Magnetic resonance (MR) imaging has been described as the most important medical innovation in the last 25 years. Over 80 million MR procedures are now performed each year and on average 2.3% (95% confidence interval: 2.0 to 2.5%) of all patients scheduled for MR imaging suffer from claustrophobia. Thus, prevention of MR imaging by claustrophobia is a common problem and approximately 2,000,000 MR procedures worldwide cannot be completed due to this situation. Patients with claustrophobic anxiety are more likely to be frightened and experience a feeling of confinement or being closed in during MR imaging. In these patients, conscious sedation and additional sequences (after sedation) may be necessary to complete the examinations. Further improvements in MR design appear to be essential to alleviate this situation and broaden the applicability of MR imaging. A more open scanner configuration might help reduce claustrophobic reactions while maintaining image quality and diagnostic accuracy.</p> <p>Methods/Design</p> <p>We propose to analyze the rate of claustrophobic reactions, clinical utility, image quality, patient acceptance, and cost-effectiveness of an open MR scanner in a randomized comparison with a recently designed short-bore but closed scanner with 97% noise reduction. The primary aim of this study is thus to determine whether an open MR scanner can reduce claustrophobic reactions, thereby enabling more examinations of claustrophobic patients without incurring the safety issues associated with conscious sedation. In this manuscript we detail the methods and design of the prospective "CLAUSTRO" trial.</p> <p>Discussion</p> <p>This randomized controlled trial will be the first direct comparison of open vertical and closed short-bore MR systems in regards to claustrophobia and image quality as well as diagnostic utility.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00715806">NCT00715806</a></p

    Study protocol for a group randomized controlled trial of a classroom-based intervention aimed at preventing early risk factors for drug abuse: integrating effectiveness and implementation research

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    <p>Abstract</p> <p>Background</p> <p>While a number of preventive interventions delivered within schools have shown both short-term and long-term impact in epidemiologically based randomized field trials, programs are not often sustained with high-quality implementation over time. This study was designed to support two purposes. The first purpose was to test the effectiveness of a universal classroom-based intervention, the Whole Day First Grade Program (WD), aimed at two early antecedents to drug abuse and other problem behaviors, namely, aggressive, disruptive behavior and poor academic achievement. The second purpose--the focus of this paper--was to examine the utility of a multilevel structure to support high levels of implementation during the effectiveness trial, to sustain WD practices across additional years, and to train additional teachers in WD practices.</p> <p>Methods</p> <p>The WD intervention integrated three components, each previously tested separately: classroom behavior management; instruction, specifically reading; and family-classroom partnerships around behavior and learning. Teachers and students in 12 schools were randomly assigned to receive either the WD intervention or the standard first-grade program of the school system (SC). Three consecutive cohorts of first graders were randomized within schools to WD or SC classrooms and followed through the end of third grade to test the effectiveness of the WD intervention. Teacher practices were assessed over three years to examine the utility of the multilevel structure to support sustainability and scaling-up.</p> <p>Discussion</p> <p>The design employed in this trial appears to have considerable utility to provide data on WD effectiveness and to inform the field with regard to structures required to move evidence-based programs into practice.</p> <p>Trial Registration</p> <p><b>Clinical Trials Registration Number</b>: NCT00257088</p

    Reconciling the professional and student identities of clinical psychology trainees

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    The study explored the ways in which qualified and trainee clinical psychologists perceived professional behaviour, as illustrated in a series of short vignettes, in student and clinical practice contexts. Comparisons were made to identify the extent to which ideas of professionalism differed across different learning contexts and between qualified and unqualified staff, with the aim of adding to the literature on which factors influence the development of professional identity in health professionals. An online questionnaire depicting a range of potentially unprofessional behaviours was completed by 265 clinical psychology trainees and 106 qualified clinical psychologists. The data were analysed using a general linear model with simultaneous entry in which rater (trainee vs qualified clinical psychologist), setting (student vs placement) and their interaction predicted acceptability ratings. We found that, in general, trainees and qualified staff agreed on those behaviours that were potentially unprofessional, although where significant differences were found, these were due to trainees rating the same behaviours as more professionally acceptable than qualified clinical psychologists. Despite trainees identifying a range of behaviours as professionally unacceptable, some percentage reported having engaged in a similar behaviour in the past. Irrespective of the status of the rater, the same behaviours tended to be viewed as more professionally unacceptable when in a placement (clinical) setting than in a student (university) setting. Generally, no support was found for a rater by setting interaction. The study suggests that trainee clinical psychologists are generally successful at identifying professional norms, although they do not always act in accordance with these. Conflicting student and professional norms may result in trainees viewing some potentially unprofessional behaviour as less severe than qualified staff. Health professional educators should be aware of this fact and take steps to shape trainee norms to be consistent with that of the professional group

    Understanding learning in the professional context 5 case studies of nurses from a pre-registration degree course

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    SIGLEAvailable from British Library Document Supply Centre-DSC:DXN019847 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Reflecting on the meaning of true nursing quality

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