The V_H repertoire and clonal diversification of B cells in inflammatory myopathies

The contribution of antigen-driven B-cell adaptive immune responses within the inflamed muscle of inflammatory myopathies (IMs) is largely unknown. In this study, we investigated the immunoglobulin VH gene repertoire, somatic hypermutation, clonal diversification, and selection of infiltrating B cells in muscle biopsies from IM patients (dermatomyositis and polymyositis), to determine whether B cells and/or plasma cells contribute to the associated pathologies of these diseases. The data reveal that Ig V<sub>H</sub> gene repertoires of muscle-infiltrating B cells deviate from the normal VH gene repertoire in individual patients, and differ between different types of IMs. Analysis of somatic mutations revealed clonal diversification of muscle-infiltrating B cells and evidence for a chronic B-cell response within the inflamed muscle. We conclude that muscle-infiltrating B cells undergo selection, somatic hypermutation and clonal diversification in situ during antigen-driven immune responses in patients with IMs, providing insight into the contribution of B cells to the pathological mechanisms of these disorders

Do medical student attitudes towards patients with chronic low back pain improve during training? a cross-sectional study

<p><b>Background:</b> Health care professionals with positive attitudes towards the functional abilities of patients with low back pain are more likely to encourage activity and avoidance of rest as per recommended guidelines. This study investigated whether medical student training fosters positive attitudes towards patients with back pain and their ability to function.</p> <p><b>Methods:</b> First (n = 202) and final (n = 146) year medical students at the University of Glasgow completed the Health Care Professionals' Pain and Impairment Relationship Scale (HC-PAIRS) questionnaire. This measures attitudes of clinicians towards the functional ability of patients with back pain. A group of first (n = 62) and final year (n = 61) business students acted as non-health care controls. Attitudes were compared using two-way ANOVA with year of study and discipline of degree as independent variables.</p> <p><b>Results:</b> Both year of study [F(1,465) = 39.5, p < 0.01] and discipline of degree [F(1,465) = 43.6, p < 0.01] had significant effects on total HC-PAIRS scores and there was a significant interaction effect [F(1,465) = 9.5, p < 0.01]. Medical students commenced their course with more positive attitudes than non-health care students (65.7 vs. 69.2 respectively; p < 0.01) - lower scores translating into more positive attitudes. In their final year, the difference between the two student groups had widened (56.4 vs. 65.3; p < 0.01).</p> <p><b>Conclusions:</b> Undergraduate medical training promotes positive attitudes towards the functional ability of patients with back pain, suggesting that students may be more likely to develop an evidence-based approach to this patient group after qualification. Some adjustments to training may be warranted to encourage a more positive shift in attitudes.</p&gt

Dense and accurate motion and strain estimation in high resolution speckle images using an image-adaptive approach

Digital image processing methods represent a viable and well acknowledged alternative to strain gauges and interferometric techniques for determining full-field displacements and strains in materials under stress. This paper presents an image adaptive technique for dense motion and strain estimation using high-resolution speckle images that show the analyzed material in its original and deformed states. The algorithm starts by dividing the speckle image showing the original state into irregular cells taking into consideration both spatial and gradient image information present. Subsequently the Newton-Raphson digital image correlation technique is applied to calculate the corresponding motion for each cell. Adaptive spatial regularization in the form of the Geman-McClure robust spatial estimator is employed to increase the spatial consistency of the motion components of a cell with respect to the components of neighbouring cells. To obtain the final strain information, local least-squares fitting using a linear displacement model is performed on the horizontal and vertical displacement fields. To evaluate the presented image partitioning and strain estimation techniques two numerical and two real experiments are employed. The numerical experiments simulate the deformation of a specimen with constant strain across the surface as well as small rigid-body rotations present while real experiments consist specimens that undergo uniaxial stress. The results indicate very good accuracy of the recovered strains as well as better rotation insensitivity compared to classical techniques

Learning contexts at two UK medical schools: A comparative study using mixed methods

Introduction: The context in which learning takes place exerts a powerful effect on the approach learners take to their work. In some instances learners will be forced by the nature of a task to adopt a less-favoured approach. In this study, we used a combination of qualitative and quantitative methods to compare the effect of context on learning at different UK medical schools. We compared schools with conventional, and problem-based curricula. Method: We had collected data from 30 interviews with third year medical students in one UK medical school with a conventional, lecture-based curriculum in relation to a previous study. The interview guide had explored effects of context and approach to learning. We used the same guide to interview 6 students in another UK medical school with a problem-based curriculum. We then put together a pack of validated questionnaires, which measured the phenomena that had emerged in the interviews. In particular we selected questionnaires which measured the criteria on which students from the different schools appeared to demonstrate greatest variance. Results: There were two areas where students from schools with differing curricula differed - basic learning activity and assessment. Students at the lecture-based school attended lectures where they received information while students at the Problem-based school attended tutorials where they stimulated prior knowledge and identified new learning objectives. Progress -testing at the problem-based school helped students gain a sense of accumulating a body of knowledge needed for their life in medicine while students' at the lecture-based school directed their learning towards passing the next set of exams. The findings from quantitative, questionnaire data correlated with the interview findings. They showed that students at a school with a PBL curriculum scored significantly higher for reflection in learning, self-efficacy in self-directed learning and for deep approach to learning. Conclusion: We set out to determine whether students at different medical schools approach their learning differently. We have succeeded in demonstrating that this is the case. The differences that we detected in learning context and approaches to learning in medical students at the two schools predict that learning at the non PBL school is likely to be via a surface approach and not integrated. These differences have major implications for the outcomes of medical student learning at the two schools in terms of accessibility and sustainability of learning

The evolution of interstellar clouds in a streaming hot plasma including heat conduction

To examine the evolution of giant molecular clouds in the stream of a hot plasma we performed two-dimensional hydrodynamical simulations that take full account of self-gravity, heating and cooling effects and heat conduction by electrons. We use the thermal conductivity of a fully ionized hydrogen plasma proposed by Spitzer and a saturated heat flux according to Cowie & McKee in regions where the mean free path of the electrons is large compared to the temperature scaleheight. Significant structural and evolutionary differences occur between simulations with and without heat conduction. Dense clouds in pure dynamical models experience dynamical destruction by Kelvin-Helmholtz (KH) instability. In static models heat conduction leads to evaporation of such clouds. Heat conduction acting on clouds in a gas stream smooths out steep temperature and density gradients at the edge of the cloud because the conduction timescale is shorter than the cooling timescale. This diminishes the velocity gradient between the streaming plasma and the cloud, so that the timescale for the onset of KH instabilities increases, and the surface of the cloud becomes less susceptible to KH instabilities. The stabilisation effect of heat conduction against KH instability is more pronounced for smaller and less massive clouds. As in the static case more realistic cloud conditions allow heat conduction to transfer hot material onto the cloud's surface and to mix the accreted gas deeper into the cloud.Comment: 19 pages, 12 figures, accepted in Astronomy and Astrophysic

Intrinsic vowel F0, the size of vowel inventories and second language acquisition

The phenomenon of intrinsic vowel F0 (IF0), in which high vowels exhibit higher F0 than low vowels, has been widely attested in languages of the world. Most often, IF0 is regarded as an automatic, physiologically determined phenomenon, whereas some claim that IF0 is a controlled feature, introduced to enhance vowel contrasts. This paper presents new evidence on this issue by means of a cross-linguistic investigation of the influence of vowel inventory size on IF0 and a study of IF0 in second language (L2) acquisition. IF0 was measured in three language varieties: Arabic (a language with 3 vowels), Dutch (a 12-vowel system), and Dutch spoken by native Arabic-speaking learners. IF0 was significantly larger in Dutch than Arabic, but did not differ significantly between Arabic and Dutch produced by L2 learners. No spectral differences between the corresponding vowels of the three language varieties were found. While confirming the universality of IF0, these results also suggest that the size of IF0 may be language-specific, depending on the need to enhance vowel contrasts. Thus, these results agree well with a mixed physiological-enhancement account, which assumes that IF0 is physiologically determined, but also at least in part the effect of an interacting, controlled mechanism