A Method for Data-Driven Simulations of Evolving Solar Active Regions

We present a method for performing data-driven simulations of solar active region formation and evolution. The approach is based on magnetofriction, which evolves the induction equation assuming the plasma velocity is proportional to the Lorentz force. The simulations of active region coronal field are driven by temporal sequences of photospheric magnetograms from the Helioseismic Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory (SDO). Under certain conditions, the data-driven simulations produce flux ropes that are ejected from the modeled active region due to loss of equilibrium. Following the ejection of flux ropes, we find an enhancement of the photospheric horizontal field near the polarity inversion line. We also present a method for the synthesis of mock coronal images based on a proxy emissivity calculated from the current density distribution in the model. This method yields mock coronal images that are somewhat reminiscent of images of active regions taken by instruments such as SDO's Atmospheric Imaging Assembly (AIA) at extreme ultraviolet wavelengths.Comment: Accepted to ApJ; comments/questions related to this article are welcome via e-mail, even after publicatio

Preuve de la validité du score de la qualité de l’évaluation pour l’apprentissage : une mesure de qualité pour les commentaires des superviseurs dans la formation médicale fondée sur les compétences

Background: Competency based medical education (CBME) relies on supervisor narrative comments contained within entrustable professional activities (EPA) for programmatic assessment, but the quality of these supervisor comments is unassessed. There is validity evidence supporting the QuAL (Quality of Assessment for Learning) score for rating the usefulness of short narrative comments in direct observation. Objective: We sought to establish validity evidence for the QuAL score to rate the quality of supervisor narrative comments contained within an EPA by surveying the key end-users of EPA narrative comments: residents, academic advisors, and competence committee members. Methods: In 2020, the authors randomly selected 52 de-identified narrative comments from two emergency medicine EPA databases using purposeful sampling. Six collaborators (two residents, two academic advisors, and two competence committee members) were recruited from each of four EM Residency Programs (Saskatchewan, McMaster, Ottawa, and Calgary) to rate these comments with a utility score and the QuAL score.  Correlation between utility and QuAL score were calculated using Pearson’s correlation coefficient. Sources of variance and reliability were calculated using a generalizability study. Results: All collaborators (n = 24) completed the full study.  The QuAL score had a high positive correlation with the utility score amongst the residents (r = 0.80) and academic advisors (r = 0.75) and a moderately high correlation amongst competence committee members (r = 0.68).  The generalizability study found that the major source of variance was the comment indicating the tool performs well across raters. Conclusion: The QuAL score may serve as an outcome measure for program evaluation of supervisors, and as a resource for faculty development.Contexte : Dans la formation médicale fondée sur les compétences (FMFC), l’évaluation programmatique s’appuie sur les commentaires narratifs des superviseurs en lien avec les activités professionnelles confiables (EPA). En revanche, la qualité de ces commentaires n’est pas évaluée. Il existe des preuves de la validité du score QuAL (qualité de l’évaluation pour l’apprentissage, Quality of Assessment for Learning en anglais) pour l’évaluation de l’utilité des commentaires de rétroaction courts lors de la supervision par observation directe. Objectif : Nous avons tenté de démontrer la validité du score QuAL aux fins de l’évaluation de la qualité des commentaires narratifs des superviseurs pour une APC en interrogeant les principaux utilisateurs finaux des rétroactions : les résidents, les conseillers pédagogiques et les membres du comité de compétence. Méthodes : En 2020, les auteurs ont sélectionné au hasard 52 commentaires narratifs anonymisés dans deux bases de données d’APC en médecine d’urgence au moyen d’un échantillonnage intentionnel. Six collaborateurs (deux résidents, deux conseillers pédagogiques et deux membres de comités de compétence) ont été recrutés dans chacun des quatre programmes de résidence en médecine d’urgence (Saskatchewan, McMaster, Ottawa et Calgary) pour évaluer ces commentaires à l’aide d’un score d’utilité et du score QuAL.  La corrélation entre l’utilité et le score QuAL a été calculée à l’aide du coefficient de corrélation de Pearson. Les sources de variance et la fiabilité ont été calculées à l’aide d’une étude de généralisabilité. Résultats : Tous les collaborateurs (n=24) ont réalisé l’étude complète.  Le score QuAL présentait une corrélation positive élevée avec le score d’utilité parmi les résidents (r=0,80) et les conseillers pédagogiques (r=0,75) et une corrélation modérément élevée parmi les membres du comité de compétence (r=0,68).  L’étude de généralisation a révélé que la principale source de variance était le commentaire, ce qui indique que l’outil a fonctionné avec une efficacité égale pour tous les évaluateurs. Conclusion : Le score QuAL peut servir de mesure des résultats pour l’évaluation des superviseurs par les programmes, et de ressource pour le perfectionnement du corps professoral

Correction to: Position statement: minimum archiving requirements for emergency medicine point‑of‑care ultrasound—a modified Delphi‑derived national consensus (Canadian Journal of Emergency Medicine, (2021), 23, 4, (450-454), 10.1007/s43678-021-00109-8)

A correction to this paper has been published: https://doi.org/10.1007/s43678-021-00117-8

Predicting the Impact of Climate Change on Threatened Species in UK Waters

Global climate change is affecting the distribution of marine species and is thought to represent a threat to biodiversity. Previous studies project expansion of species range for some species and local extinction elsewhere under climate change. Such range shifts raise concern for species whose long-term persistence is already threatened by other human disturbances such as fishing. However, few studies have attempted to assess the effects of future climate change on threatened vertebrate marine species using a multi-model approach. There has also been a recent surge of interest in climate change impacts on protected areas. This study applies three species distribution models and two sets of climate model projections to explore the potential impacts of climate change on marine species by 2050. A set of species in the North Sea, including seven threatened and ten major commercial species were used as a case study. Changes in habitat suitability in selected candidate protected areas around the UK under future climatic scenarios were assessed for these species. Moreover, change in the degree of overlap between commercial and threatened species ranges was calculated as a proxy of the potential threat posed by overfishing through bycatch. The ensemble projections suggest northward shifts in species at an average rate of 27 km per decade, resulting in small average changes in range overlap between threatened and commercially exploited species. Furthermore, the adverse consequences of climate change on the habitat suitability of protected areas were projected to be small. Although the models show large variation in the predicted consequences of climate change, the multi-model approach helps identify the potential risk of increased exposure to human stressors of critically endangered species such as common skate (Dipturus batis) and angelshark (Squatina squatina)

FAD binding, cobinamide binding and active site communication in the corrin reductase (CobR)

Adenosylcobalamin, the coenzyme form of vitamin B12, is one Nature's most complex coenzyme whose de novo biogenesis proceeds along either an anaerobic or aerobic metabolic pathway. The aerobic synthesis involves reduction of the centrally chelated cobalt metal ion of the corrin ring from Co(II) to Co(I) before adenosylation can take place. A corrin reductase (CobR) enzyme has been identified as the likely agent to catalyse this reduction of the metal ion. Herein, we reveal how Brucella melitensis CobR binds its coenzyme FAD (flavin dinucleotide) and we also show that the enzyme can bind a corrin substrate consistent with its role in reduction of the cobalt of the corrin ring. Stopped-flow kinetics and EPR reveal a mechanistic asymmetry in CobR dimer that provides a potential link between the two electron reduction by NADH to the single electron reduction of Co(II) to Co(I)

The theory of international business: the role of economic models

This paper reviews the scope for economic modelling in international business studies. It argues for multi-level theory based on classic internalisation theory. It present a systems approach that encompasses both firm-level and industry-level analysis

Supertwistor space for 6D maximal super Yang-Mills

6D maximal super Yang-Mills on-shell amplitudes are formulated in superspace using 6 dimensional twistors. The 3,4,5-point tree amplitudes are obtained by supersymmetrizing their bosonic counterparts and confirmed through the BCFW construction. In contrast to 4D this superspace is non-chiral, reflecting the fact that one cannot differentiate MHV from $\bar{{\rm MHV}}$ in 6D. Combined with unitarity methods, this superspace should be useful for the study of multi-loop D dimensional maximal super Yang-Mills and gravity amplitudes. Furthermore, the non-chiral nature gives a natural framework for an off-shell construction. We show this by matching our result with off-shell D=4 N=4 super Yang-Mills amplitudes, expressed in projective superspace.Comment: 6 figures 28 pages. with better sign