Improving the teaching skills of residents as tutors/facilitators and addressing the shortage of faculty facilitators for PBL modules

BACKGROUND: Residents play an important role in teaching of medical undergraduate students. Despite their importance in teaching undergraduates they are not involved in any formal training in teaching and leadership skills. We aimed to compare the teaching skills of residents with faculty in facilitating small group Problem Based Learning (PBL) sessions. METHODS: This quasi experimental descriptive comparative research involved 5 postgraduate year 4 residents and five senior faculty members. The study was conducted with all phase III (Final year) students rotating in Gastroenterology. The residents and faculty members received brief training of one month in facilitation and core principles of adult education. Different aspects of teaching skills of residents and faculty were evaluated by students on a questionnaire (graded on Likert Scale from 1 to 10) assessing i) Knowledge Base-content Learning (KBL), ii) PBL, iii) Student Centered Learning (SCL) and iv) Group Skills (GS). RESULTS: There were 33 PBL teaching sessions in which 120 evaluation forms were filled; out of these 53% forms were filled for residents and 47% for faculty group. The faculty showed a statistically greater rating in KBL (faculty 8.37 Vs resident 7.94; p-value 0.02), GS (faculty 8.06 vs. residents 7.68; p-value 0.04). Differences in faculty and resident scores in the PBL and SCL were not significant. The overall score of faculty facilitators, however, was statistically significant for resident facilitators. (p = .05). CONCLUSION: 1) Residents are an effective supplement to faculty members for PBL; 2) Additional facilitators for PBL sessions can be identified in an institution by involvement of residents in teacher training workshop

N- and C-Terminal Domains of the Calcium Binding Protein EhCaBP1 of the Parasite Entamoeba histolytica Display Distinct Functions

Entamoeba histolytica, a protozoan parasite, is the causative agent of amoebiasis, and calcium signaling is thought to be involved in amoebic pathogenesis. EhCaBP1, a Ca2+ binding protein of E. histolytica, is essential for parasite growth. High resolution crystal structure of EhCaBP1 suggested an unusual arrangement of the EF-hand domains in the N-terminal part of the structure, while C-terminal part of the protein was not traced. The structure revealed a trimer with amino terminal domains of the three molecules interacting in a head-to-tail manner forming an assembled domain at the interface with EF1 and EF2 motifs of different molecules coming close to each other. In order to understand the specific roles of the two domains of EhCaBP1, the molecule was divided into two halves, and each half was separately expressed. The domains were characterized with respect to their structure, as well as specific functional features, such as ability to activate kinase and bind actin. The domains were also expressed in E. histolytica cells along with green fluorescent protein. The results suggest that the N-terminal domain retains some of the properties, such as localization in phagocytic cups and activation of kinase. Crystal structure of EhCaBP1 with Phenylalanine revealed that the assembled domains, which are similar to Calmodulin N-terminal domain, bind to Phenylalanine revealing the binding mode to the target proteins. The C-terminal domain did not show any of the activities tested. However, over-expression in amebic cells led to a dominant negative phenotype. The results suggest that the two domains of EhCaBP1 are functionally and structurally different from each other. Both the domains are required for structural stability and full range of functional diversity

Higher prevalence of smoking and lower BMI, waist circumference, cholesterol and triacylglyceride levels in Prague's homeless compared to a majority of the Czech population

BACKGROUND: Homeless people have higher morbidity and mortality rates than the general population. Research has shown that cardiovascular disease is the leading cause of death in older homeless adults. This study was undertaken to describe the prevalence of cardiovascular risk factors in the homeless population in Prague. METHODS: Data was obtained from a cross-sectional study carried out in 2003. Body mass index (BMI), waist circumference (WC), total cholesterol (TC), triacylglycerides (TAG) and smoking habits were assessed. The homeless participants in the study were recruited from a homeless center run by a Prague charitable organization called Naděje ("Hope") and at Prague's main railway station. Most participants were assessed at the Naděje center (134 persons) while the rest were assessed at Prague's Bulovka University Hospital (67 persons). RESULTS: A total of 201 homeless (174 males and 27 females) aged 19 – 70 years were examined. Mean values of BMI, WC, TC and TAG in homeless men and women were within normal limits. Compared with the majority of the Czech population, the homeless had significantly lower mean levels of TC and TAG and lower BMI and WC values. When compared to the majority of the Czech population, the incidence of smoking among the homeless was significantly higher. Among smokers in both populations, no differences were found in the number of cigarettes smoked per day. CONCLUSION: Classical cardiovascular risk factors such as TC, TAG, BMI and WC, are significantly lower in Prague's homeless minority than in the majority of the Czech population. However, the prevalence of smoking is much higher in the homeless population

Expression of MAGE-C1/CT7 and MAGE-C2/CT10 Predicts Lymph Node Metastasis in Melanoma Patients

MAGE-C1/CT7 and MAGE-C2/CT10 are members of the large MAGE family of cancer-testis (CT) antigens. CT antigens are promising targets for immunotherapy in cancer because their expression is restricted to cancer and germ line cells and a proportion of cancer patients presents with immune responses against CT antigens, which clearly demonstrates their immunogenicity. This study investigates the expression of MAGE-C1/CT7 and MAGE-C2/CT10 in primary and metastatic melanoma. Immunohistochemical staining of tissue microarrays that consisted of 59 primary malignant melanomas of the skin, 163 lymph node and distant melanoma metastases and 68 melanoma cell lines was performed. We found MAGE-C1/CT7 expression in 15 out of 50 (24%) primary melanomas and 15 out of 50 (24%) cell lines, whereas MAGE-C2/CT10 was detected in 17 out of 51 (33%) primary melanomas and 14 out of 68 (17%) cell lines. MAGE-C1/CT7 and MAGE-C2/CT10 were both detected in 40% of melanoma metastases. Patients with MAGE-C1/CT7 or MAGE-C2/CT10 positive primary melanoma had significantly more lymph node metastases (p = 0.005 and p<0.001, resp.). Prediction of lymph node metastasis by MAGE-C1/CT7 and MAGE-C2/CT10 was independent of tumor cell proliferation rate (Ki67 labeling index) in a multivariate analysis (p = 0.01). Our results suggest that the expression of MAGE-C1/CT7 and MAGE-C2/CT10 in primary melanoma is a potent predictor of sentinel lymph node metastasis

Promoter Complexity and Tissue-Specific Expression of Stress Response Components in Mytilus galloprovincialis, a Sessile Marine Invertebrate Species

The mechanisms of stress tolerance in sessile animals, such as molluscs, can offer fundamental insights into the adaptation of organisms for a wide range of environmental challenges. One of the best studied processes at the molecular level relevant to stress tolerance is the heat shock response in the genus Mytilus. We focus on the upstream region of Mytilus galloprovincialis Hsp90 genes and their structural and functional associations, using comparative genomics and network inference. Sequence comparison of this region provides novel evidence that the transcription of Hsp90 is regulated via a dense region of transcription factor binding sites, also containing a region with similarity to the Gamera family of LINE-like repetitive sequences and a genus-specific element of unknown function. Furthermore, we infer a set of gene networks from tissue-specific expression data, and specifically extract an Hsp class-associated network, with 174 genes and 2,226 associations, exhibiting a complex pattern of expression across multiple tissue types. Our results (i) suggest that the heat shock response in the genus Mytilus is regulated by an unexpectedly complex upstream region, and (ii) provide new directions for the use of the heat shock process as a biosensor system for environmental monitoring

Geometry and field theory in multi-fractional spacetime

We construct a theory of fields living on continuous geometries with fractional Hausdorff and spectral dimensions, focussing on a flat background analogous to Minkowski spacetime. After reviewing the properties of fractional spaces with fixed dimension, presented in a companion paper, we generalize to a multi-fractional scenario inspired by multi-fractal geometry, where the dimension changes with the scale. This is related to the renormalization group properties of fractional field theories, illustrated by the example of a scalar field. Depending on the symmetries of the Lagrangian, one can define two models. In one of them, the effective dimension flows from 2 in the ultraviolet (UV) and geometry constrains the infrared limit to be four-dimensional. At the UV critical value, the model is rendered power-counting renormalizable. However, this is not the most fundamental regime. Compelling arguments of fractal geometry require an extension of the fractional action measure to complex order. In doing so, we obtain a hierarchy of scales characterizing different geometric regimes. At very small scales, discrete symmetries emerge and the notion of a continuous spacetime begins to blur, until one reaches a fundamental scale and an ultra-microscopic fractal structure. This fine hierarchy of geometries has implications for non-commutative theories and discrete quantum gravity. In the latter case, the present model can be viewed as a top-down realization of a quantum-discrete to classical-continuum transition.Comment: 1+82 pages, 1 figure, 2 tables. v2-3: discussions clarified and improved (especially section 4.5), typos corrected, references added; v4: further typos correcte

The First Stars

The first stars to form in the Universe -- the so-called Population III stars -- bring an end to the cosmological Dark Ages, and exert an important influence on the formation of subsequent generations of stars and on the assembly of the first galaxies. Developing an understanding of how and when the first Population III stars formed and what their properties were is an important goal of modern astrophysical research. In this review, I discuss our current understanding of the physical processes involved in the formation of Population III stars. I show how we can identify the mass scale of the first dark matter halos to host Population III star formation, and discuss how gas undergoes gravitational collapse within these halos, eventually reaching protostellar densities. I highlight some of the most important physical processes occurring during this collapse, and indicate the areas where our current understanding remains incomplete. Finally, I discuss in some detail the behaviour of the gas after the formation of the first Population III protostar. I discuss both the conventional picture, where the gas does not undergo further fragmentation and the final stellar mass is set by the interplay between protostellar accretion and protostellar feedback, and also the recently advanced picture in which the gas does fragment and where dynamical interactions between fragments have an important influence on the final distribution of stellar masses.Comment: 72 pages, 4 figures. Book chapter to appear in "The First Galaxies - Theoretical Predictions and Observational Clues", 2012 by Springer, eds. V. Bromm, B. Mobasher, T. Wiklin