BACKGROUND:Physical Examination (PE) skills are vital for patient care, and many medical students receive their first introduction to them in their pre-clinical years. A substantial amount of curriculum time is devoted to teaching these skills in most schools. Little is known about the best way to introduce PE skills to novice learners. OBJECTIVE:Our objective was to conduct a systematic review of how medical students are first taught PE skills and the evidence supporting these strategies. DESIGN:We searched ERIC, SCOPUS, MEDLINE, PubMed and EMBASE for descriptions of complete PE curricula for novice learners. Inclusion criteria were: (1) English language; (2) subjects were enrolled in medical school and were in the preclinical portion of their training; (3) description of a method to teach physical examination skills for the first time; (4) description of the study population; (5) Description of a complete PE curriculum. We used the Medical Education Research Study Quality Instrument (MERSQI) score to evaluate the quality of evidence provided. RESULTS:Our search returned 5,418 articles; 32 articles met our inclusion criteria. Two main types of curricula were reported: comprehensive 'head-to-toe' PE curricula (18%) and organ system-based curricula (41%). No studies compared these directly, and only two evaluated trainees' clinical performance. The rest of the articles described interventions used across curricula (41%). Median MERSQI score was 10.1 Interquartile range 8.1-12.4. We found evidence for the use of non-faculty teaching associates, technology-enhanced PE education, and the addition of clinical exposure to formal PE teaching. CONCLUSIONS:The current literature on teaching PE is focused on describing innovations to head-to-toe and organ system-based curricula rather than their relative effectiveness, and is further limited by its reliance on short-term outcomes. The optimal strategy for novice PE instruction remains unknown.
© 2018 American Chemical Society. This work presents the first direct evidence of multivalent binding between bone morphogenetic protein-2 (BMP-2) and cartilage oligomeric matrix protein (COMP) using high-resolution atomic force microscopy (AFM) imaging. AFM topographic images reveal the molecular morphology of COMP, a pentameric protein whose five identical monomer units bundle together at N-termini, extending out with flexible chains to C-termini. Upon addition of BMP-2, COMP molecules undergo conformational changes at the C-termini to enable binding with BMP-2 molecules. AFM enables local structural changes of COMP to be revealed upon binding various numbers, 1-5, of BMP-2 molecules. These BMP-2/COMP complexes exhibit very different morphologies from those of COMP: much more compact and thus less flexible. These molecular-level insights deepen current understanding of the mechanism of how the BMP-2/COMP complex enhances osteogenesis among osteoprogenitor cells, i.e., multivalent presentation of BMP-2 via the stable and relatively rigid BMP-2/COMP complex could form a lattice of interaction between multiple BMP-2 and BMP-2 receptors. These ligand-receptor clusters lead to fast initiation and sustained activation of the Smad signaling pathway, resulting in enhanced osteogenesis. This work is also of translational importance as the outcome may enable use of lower BMP-2 dosage for bone repair and regeneration.
© 2019 Elsevier Ltd Toxic chemicals within and adsorbed to microplastics (0.05–5 mm) have the potential to biomagnify in food webs. However, microplastic concentrations in highly productive, coastal habitats are not well understood. Therefore, we quantified the presence of microplastics in a benthic community and surrounding environment of a remote marine reserve on the open coast of California, USA. Concentrations of microplastic particles in seawater were 36.59 plastics/L and in sediments were 0.227 ± 0.135 plastics/g. Densities of microplastics on the surfaces of two morphologically distinct species of macroalgae were 2.34 ± 2.19 plastics/g (Pelvetiopsis limitata) and 8.65 ± 6.44 plastics/g (Endocladia muricata). Densities were highest in the herbivorous snail, Tegula funebralis, at 9.91 ± 6.31 plastics/g, potentially due to bioaccumulation. This study highlights the need for further investigations of the prevalence and potential harm of microplastics in benthic communities at remote locations as well as human population centers.
© 2019 The Authors Effective study and management of crops and forests would benefit greatly from useful plant-based indicators of the biological controls on evapotranspiration, and particularly stomatal conductance (g s ). Given the strong influence of g s on bulk leaf water potential and turgor pressure (P), in vivo measurement of P may provide useful information about diurnal or seasonal dynamics of g s . Moderate plant water stress affects the diurnal dynamics of P as leaf-to-air vapour pressure deficit (D) varies, and these dynamics correlate to g s . Here, we explored relative changes in P in response to changes in D under mild drought conditions, and how these changes are linked to stomatal behaviour, and specifically to diurnal maximum g s (g s,max ), one of the best indicators of plant water stress. We monitored ecophysiological and environmental variables, as well as a relative proxy for P, during three consecutive seasons in a hedgerow olive orchard where trees were supplied with different irrigation treatments to create well-watered and moderately water-stressed conditions. Our results demonstrated that the sensitivity of P to D correlated well with g s,max reached by the trees within a range in which variations in g s are the main diffusional limitation to photosynthesis. We further showed that this correlation held under a wide range of meteorological conditions and soil water availability. This turgor proxy measurement, which is much easier to measure than g s , can facilitate the use of g s,max as an indicator of plant water stress and evapotranspiration in agriculture and plant science research.
© 2019 Elsevier Ltd Research suggests that people tend to use one of four rationalizations to justify eating meat despite its empirically established negative consequences for both personal and societal well-being: the beliefs that meat is natural, necessary, normal, or nice. The goal of this study was to better understand what kind of people would tend to use these different rationalizations in terms of their personality traits, values, and motivations for plant-based eating. Results suggest specific psychological profiles for each of the four meat-eating rationalizations. These profiles may be useful for behavior change advocacy and for furthering the basic science of individual differences underlying food preferences and choices. Suggestions for future research that builds upon these initial findings are highlighted.