104 research outputs found

    Preliminary measurements of lumbar spine kinematics and stiffness

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    The purpose of the presented study was the experimental measurement of lumbar spine stiffness and its range of motion. The dependence of torsion moment of lumbar spine segment on deflection of flexion, extension and torsion was observed during experiments. Stiffness of spine segment was determined from measured data. Human lumbar spine was used for verification of the experimental technique. The sample consisted of one lumbar vertebrae composed by five vertebral bodies and four intervertebral discs. All muscles were removed, however all ligaments were preserved. Experiments were ca rried out on the test system MTS 858.2 MiniBionix, where loading by axial force and torsion moment is possible at the same time. Special Modular Bionix Spine Test Fixator, attached to the test system was used for the measurements. Loading was controlled kinematically (gradual turning) by keeping the axial force equal zero. Measurement was timedependent. The results of these experiments are going to be used as input data for creating a model of artificial lumbar spine and new type of artificial disc replacement

    Hadro-Chemistry and Evolution of (Anti-) Baryon Densities at RHIC

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    The consequences of hadro-chemical freezeout for the subsequent hadron gas evolution in central heavy-ion collisions at RHIC and LHC energies are discussed with special emphasis on effects due to antibaryons. Contrary to naive expectations, their individual conservation, as implied by experimental data, has significant impact on the chemical off-equilibrium composition of hadronic matter at collider energies. This may reflect on a variety of observables including source sizes and dilepton spectra.Comment: 4 pages ReVTeX incl. 3 ps-figs, submitted to PR

    3D Fluid Flow Estimation with Integrated Particle Reconstruction

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    The standard approach to densely reconstruct the motion in a volume of fluid is to inject high-contrast tracer particles and record their motion with multiple high-speed cameras. Almost all existing work processes the acquired multi-view video in two separate steps, utilizing either a pure Eulerian or pure Lagrangian approach. Eulerian methods perform a voxel-based reconstruction of particles per time step, followed by 3D motion estimation, with some form of dense matching between the precomputed voxel grids from different time steps. In this sequential procedure, the first step cannot use temporal consistency considerations to support the reconstruction, while the second step has no access to the original, high-resolution image data. Alternatively, Lagrangian methods reconstruct an explicit, sparse set of particles and track the individual particles over time. Physical constraints can only be incorporated in a post-processing step when interpolating the particle tracks to a dense motion field. We show, for the first time, how to jointly reconstruct both the individual tracer particles and a dense 3D fluid motion field from the image data, using an integrated energy minimization. Our hybrid Lagrangian/Eulerian model reconstructs individual particles, and at the same time recovers a dense 3D motion field in the entire domain. Making particles explicit greatly reduces the memory consumption and allows one to use the high-res input images for matching. Whereas the dense motion field makes it possible to include physical a-priori constraints and account for the incompressibility and viscosity of the fluid. The method exhibits greatly (~70%) improved results over our recently published baseline with two separate steps for 3D reconstruction and motion estimation. Our results with only two time steps are comparable to those of sota tracking-based methods that require much longer sequences.Comment: To appear in International Journal of Computer Vision (IJCV

    Three-Dimensional two-pion source image from Pb+Pb Collisions at Sqrts_NN=17.3 GeV: New constraints for source breakup dynamics

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    Source imaging methodology is used to provide a three-dimensional two-pion source function for mid-rapidity pion pairs with pT<70p_T<70 MeV/c in central (0−70-7%) Pb+Pb collisions at sNN\sqrt s_{NN}=17.3 GeV. Prominent non-Gaussian tails are observed in the pion pair transverse momentum (outward) and in the beam (longitudinal) directions. Model calculations reproduce them with the assumption of Bjorken longitudinal boost invariance and transverse flow blast-wave dynamics coupled with "outside-in burning" in the transverse direction; they also yield a proper time for breakup and emission duration for the pion source.Comment: Six pages 4 figs. Submitted for publicatio

    The meaning of compassion fatigue to student nurses: an interpretive phenomenological study

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    Background: Compassion fatigue is a form of occupational stress which occurs when individuals are exposed to suffering and trauma on an ongoing basis. The purpose of this study was to explore the experiences of compassion fatigue among student nurses following their first clinical placement in a UK health care setting during 2015. Methods: The aim of this study was to explore students’ thoughts and feelings about compassion fatigue using reflective poems as a source of data. An interpretive phenomenological approach was taken using a purposeful sampling strategy which aimed to explore in depth meaning of the concept as experienced by the students. Results: From this study it is clear that students experience compassion fatigue and this has a psychological effect on their wellbeing and ability to learn in the clinical practice setting. Reflective poetry writing enabled articulation of feelings which were at times negative and linked to the student’s status as a novice nurse. Conclusions: Students experience compassion fatigue and educators need to find ways to provide support in both clinical and university settings. Positive practices such as shared reflection and the use of creative teaching methods might be beneficial, to support exploration of feelings, build resilience and effective ways of coping

    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

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome
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