Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.

We report a high-quality draft of the genome sequence of the grey, short-tailed opossum (Monodelphis domestica). As the first metatherian ('marsupial') species to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. Distinctive features of the opossum chromosomes provide support for recent theories about genome evolution and function, including a strong influence of biased gene conversion on nucleotide sequence composition, and a relationship between chromosomal characteristics and X chromosome inactivation. Comparison of opossum and eutherian genomes also reveals a sharp difference in evolutionary innovation between protein-coding and non-coding functional elements. True innovation in protein-coding genes seems to be relatively rare, with lineage-specific differences being largely due to diversification and rapid turnover in gene families involved in environmental interactions. In contrast, about 20% of eutherian conserved non-coding elements (CNEs) are recent inventions that postdate the divergence of Eutheria and Metatheria. A substantial proportion of these eutherian-specific CNEs arose from sequence inserted by transposable elements, pointing to transposons as a major creative force in the evolution of mammalian gene regulation.

Both first- and second-year students, regardless of their gender, academic background, or citizenship felt that the time devoted to dissection classes were not adequate. Students agreed that dissection deepened their understanding of anatomical structures, provided them with a three-dimensional perspective of structures and helped them recall what they learnt. Although their perception about the importance of dissection changed as they progressed in the course, good anatomy textbooks were perceived as an excellent resource for learning anatomy. Interestingly, innovations used in teaching anatomy, such as interactive multimedia resources, have not replaced students' perceptions about the importance of dissection.

Currently, YouTube is an inadequate source of information for learning surface anatomy. More work is needed from medical schools and educators to add useful videos on YouTube covering this area.

BackgroundA number of studies have evaluated the educational contents of videos on YouTube. However, little analysis has been done on videos about physical examination.ObjectiveThis study aimed to analyze YouTube videos about physical examination of the cardiovascular and respiratory systems. It was hypothesized that the educational standards of videos on YouTube would vary significantly.MethodsDuring the period from November 2, 2011 to December 2, 2011, YouTube was searched by three assessors for videos covering the clinical examination of the cardiovascular and respiratory systems. For each video, the following information was collected: title, authors, duration, number of viewers, and total number of days on YouTube. Using criteria comprising content, technical authority, and pedagogy parameters, videos were rated independently by three assessors and grouped into educationally useful and non-useful videos.ResultsA total of 1920 videos were screened. Only relevant videos covering the examination of adults in the English language were identified (n=56). Of these, 20 were found to be relevant to cardiovascular examinations and 36 to respiratory examinations. Further analysis revealed that 9 provided useful information on cardiovascular examinations and 7 on respiratory examinations: scoring mean 14.9 (SD 0.33) and mean 15.0 (SD 0.00), respectively. The other videos, 11 covering cardiovascular and 29 on respiratory examinations, were not useful educationally, scoring mean 11.1 (SD 1.08) and mean 11.2 (SD 1.29), respectively. The differences between these two categories were significant (P<.001 for both body systems). The concordance between the assessors on applying the criteria was 0.89, with a kappa score >.86.ConclusionsA small number of videos about physical examination of the cardiovascular and respiratory systems were identified as educationally useful; these videos can be used by medical students for independent learning and by clinical teachers as learning resources. The scoring system utilized by this study is simple, easy to apply, and could be used by other researchers on similar topics.

The novel coronavirus disease 2019 (COVID-19) outbreak started in early December 2019 in the capital city of Wuhan, Hubei province, People's Republic of China, and caused a global pandemic. The number of patients confirmed to have this disease has exceeded 9 million in more than 215 countries, and more than 480 600 have died as of 25 June 2020. Coronaviruses were identified in the 1960s and have recently been identified as the cause of a Middle East respiratory syndrome (MERS-CoV) outbreak in 2012 and a severe acute respiratory syndrome (SARS) outbreak in 2003. The current SARS coronavirus 2 (SARS-CoV-2) is the most recently identified. Patients with COVID-19 may be asymptomatic. Typical symptoms include fever, dry cough and shortness of breath. Gastrointestinal symptoms such as nausea, vomiting, abdominal pain and diarrhoea have been reported; neurologically related symptoms, particularly anosmia, hyposmia and dysgeusia, have also been reported. Physical examination may find fever in over 44% of patients (and could be documented in over 88% of patients after admission), increased respiratory rate, acute respiratory disease and maybe decreased consciousness, agitation and confusion. This article aims at presenting an up-to-date review on the pathogenesis, diagnosis and complications of COVID-19 infection. Currently no therapeutics have been found to be effective. Investigational therapeutics are briefly discussed.

The finding that over half of List B articles were published in nonmedical education journals is consistent with medical education's integrated nature and subspecialty breadth. Twenty of these articles were among their respective non-medical-education journals' 50 top-cited papers, showing that medical education articles can compete with subject-based articles.

One of the main tasks of a problem-based learning (PBL) tutor is to facilitate group discussion. Group facilitation is about process rather than content. In this process, a tutor helps the group increase their skills and progress in their discussion. Several studies have highlighted strategies and training used in preparing PBL tutors. However, PBL tutors usually feel that it is not that easy to change their teaching style to the PBL format. They are sometimes unsure about their role or what strategy they might use to facilitate their students' discussion. This article in the '12 Tips' series is a detailed description of, and provides answers to, common challenges faced by PBL tutors. The tips provided in this manuscript should help tutors with practical answers. The article may be useful to PBL tutors, medical and health educators and those responsible for PBL training workshops.