Assessing the scholar CanMEDS role in residents using critical appraisal techniques

Background: In this brief report, we describe two ways in which we assessed the Scholar CanMEDS role using a method to measure residents’ ability to complete a critical appraisal.  These were incorporated into a modified OSCE format where two stations consisted of 1) critically appraising an article and 2) critiquing an abstract.Method: Residents were invited to participate in the CanMEDS In-Training Exam (CITE) through the Office of Postgraduate Medical Education. Mean scores for the two Scholar stations were calculated using the number of correct responses out of 10. The global score represented the examiner’s overall impression of the resident’s knowledge and effort.  Correlations between scores are also presented between the two Scholar stations and a paired sample t-test comparing the global mean scores of the two stations was also performed.Results: Sixty-three of the 64 residents registered to complete the CanMEDS In-Training Exam including the two Scholar stations.  There were no significant differences between the global scores of the Scholar stations showing that the overall knowledge and effort of the residents was similar across both stations (3.8 vs. 3.5, p = 0.13).  The correlation between the total mean scores of both stations (inter-station reliability) was also non-significant (r = 0.05, p = 0.67).  No significant differences between senior residents and junior residents were detected or between internal medicine residents and non-internal medicine residents.Conclusion: Further testing of these stations is needed and other novel ways of assessing the Scholar role competencies should also be investigated

Genome-wide association study of 107 phenotypes in Arabidopsis thaliana inbred lines

International audienceAlthough pioneered by human geneticists as a potential solution to the challenging problem of finding the genetic basis of common human diseases1,2, genome-wide association (GWA) studies have, owing to advances in genotyping and sequencing technology, become an obvious general approach for studying the genetics of natural variation and traits of agricultural importance. They are particularly useful when inbred lines are available, because once these lines have been genotyped they can be phenotyped multiple times, making it possible (as well as extremely cost effective) to study many different traits in many different environments, while replicating the phenotypic measurements to reduce environmental noise. Here we demonstrate the power of this approach by carrying out a GWA study of 107 phenotypes in Arabidopsis thaliana, a widely distributed, predominantly self-fertilizing model plant known to harbour considerable genetic variation for many adaptively important traits3. Our results are dramatically different from those of human GWA studies, in that we identify many common alleles of major effect, but they are also, in many cases, harder to interpret because confounding by complex genetics and population structure make it difficult to distinguish true associations from false. However, a-priori candidates are significantly over-represented among these associations as well, making many of them excellent candidates for follow-up experiments. Our study demonstrates the feasibility of GWA studies in A. thaliana and suggests that the approach will be appropriate for many other organisms

Natural allelic variation underlying a major fitness trade-off in Arabidopsis thaliana

Plants can defend themselves against a wide array of enemies, from microbes to large animals, yet there is great variability in the effectiveness of such defences, both within and between species. Some of this variation can be explained by conflicting pressures from pathogens with different modes of attack. A second explanation comes from an evolutionary tug of war, in which pathogens adapt to evade detection, until the plant has evolved new recognition capabilities for pathogen invasion. If selection is, however, sufficiently strong, susceptible hosts should remain rare. That this is not the case is best explained by costs incurred from constitutive defences in a pest-free environment. Using a combination of forward genetics and genome-wide association analyses, we demonstrate that allelic diversity at a single locus, ACCELERATED CELL DEATH 6 (ACD6), underpins marked pleiotropic differences in both vegetative growth and resistance to microbial infection and herbivory among natural Arabidopsis thaliana strains. A hyperactive ACD6 allele, compared to the reference allele, strongly enhances resistance to a broad range of pathogens from different phyla, but at the same time slows the production of new leaves and greatly reduces the biomass of mature leaves. This allele segregates at intermediate frequency both throughout the worldwide range of A. thaliana and within local populations, consistent with this allele providing substantial fitness benefits despite its marked impact on growth