Introduction de carnets d’apprentissage expérientiel portant sur la responsabilité sociale à l’externat au doctorat de premier cycle en médecine

Implication Statement Medical schools have a responsibility to ensure students meet and advocate for the needs of the community. However, addressing the social determinants of health is not always emphasized in clinical learning objectives. Learning logs are useful tools that can engage students to reflect on clinical encounters and direct students in their learning to target the development of highlighted skills. Despite their efficacy, the use of learning logs in medical education is largely applied towards biomedical knowledge and procedural skills. Thus, students may lack competence to address the psychosocial challenges involved in comprehensive medical care. Social accountability experiential logs were developed for third year medical students at the University of Ottawa to address and intervene on the social determinants of health. Students completed quality improvement surveys and results demonstrated this initiative to be beneficial to their learning and contributed to greater clinical confidence. Experiential logs in clinical training can be adapted across other medical schools and tailored to fit the needs and priorities of each institution’s local communities.Énoncé des implications de la recherche Les facultés de médecine ont la responsabilité de s’assurer que les étudiants répondent aux besoins de la collectivité et militent pour leur satisfaction. Or, les objectifs d’apprentissage clinique ne sont pas toujours axés sur les déterminants sociaux de la santé. L’utilité des carnets d’apprentissage est d’inciter les étudiants à réfléchir sur les rencontres cliniques et de les orienter dans leur apprentissage vers le développement des compétences ciblées. Malgré leur efficacité, les carnets d’apprentissage sont surtout appliqués aux connaissances biomédicales et aux compétences procédurales. Par conséquent, les étudiants pourraient ne pas disposer des compétences nécessaires pour relever les enjeux psychosociaux, qui sont à considérer aux fins d’une prise en charge médicale globale. Des carnets d’apprentissage expérientiel portant sur la responsabilité sociale ont été élaborés pour les étudiants en médecine de troisième année de l’Université d’Ottawa afin d’aborder et d’intervenir sur les déterminants sociaux de la santé. Les étudiants ont participé à des sondages sur l’amélioration de la qualité et les résultats de ceux-ci ont montré que cette initiative était bénéfique pour leur apprentissage et qu’elle contribuait à améliorer leur confiance en eux en tant que cliniciens. Les carnets expérientiels en formation clinique peuvent être adaptés par les diverses facultés de médecine pour qu’ils correspondent aux besoins et aux priorités des collectivités locales qu’elles desservent

CO2 Control of Trichodesmium N-2 Fixation, Photosynthesis, Growth rates, and Elemental Ratios: Implications for Past, Present, and Future Ocean Biogeochemistry

Diazotrophic marine cyanobacteria in the genus Trichodesmium contribute a large fraction of the new nitrogen entering the oligotrophic oceans, but little is known about how they respond to shifts in global change variables such as carbon dioxide (CO2) and temperature. We compared Trichodesmium dinitrogen (N2) and CO2 fixation rates during steady-state growth under past, current, and future CO2 scenarios, and at two relevant temperatures. At projected CO2 levels of year 2100 (76 Pa, 750 ppm), N2 fixation rates of Pacific and Atlantic isolates increased 35-100%, and CO2 fixation rates increased 15-128% relative to present day CO2 conditions (39 Pa, 380 ppm). CO2 mediated rate increases were of similar relative magnitude in both phosphorus (P)-replete and P-limited cultures, suggesting that this effect may be independent of resource limitation. Neither isolate could grow at 15 Pa (150 ppm) CO2, but N2 and CO2 fixation rates, growth rates, and nitrogen : phosophorus (N : P) ratios all increased significantly between 39 Pa and 152 Pa (1500 ppm). In contrast, these parameters were affected only minimally or not at all by a 4°C temperature change. Photosynthesis versus irradiance parameters, however, responded to both CO2 and temperature but in different ways for each isolate. These results suggest that by the end of this century, elevated CO2 could substantially increase global Trichodesmium N2 and CO2 fixation, fundamentally altering the current marine N and C cycles and potentially driving some oceanic regimes towards P limitation. CO2 limitation of Trichodesmium diazotrophy during past glacial periods could also have contributed to setting minimum atmospheric CO2 levels through downregulation of the biological pump. The relationship between marine N2 fixation and atmospheric CO2 concentration appears to be more complex than previously realized and needs to be considered in the context of the rapidly changing oligotrophic oceans

Enhanced transport at high plasma β\beta and sub-threshold kinetic ballooning modes in Wendelstein 7-X

The effect of plasma pressure $\beta$ on ion-temperature-gradient-driven (ITG) turbulence is studied in the Wendelstein 7-X (W7-X) stellarator, showing that subdominant kinetic ballooning modes (KBMs) are unstable well below the ideal MHD threshold and get strongly excited in the quasi-stationary state. By zonal-flow erosion, these highly non-ideal KBMs affect ITG saturation and thereby enable higher heat fluxes. Controlling these KBMs will be essential in order to allow W7-X and future stellarators to achieve maximum performance.Comment: 16 pages, 5 figure

Implementing experiential learning logs addressing social accountability into undergraduate medical clerkship education

Implication Statement Medical schools have a responsibility to ensure students meet and advocate for the needs of the community. However, addressing the social determinants of health is not always emphasized in clinical learning objectives. Learning logs are useful tools that can engage students to reflect on clinical encounters and direct students in their learning to target the development of highlighted skills. Despite their efficacy, the use of learning logs in medical education is largely applied towards biomedical knowledge and procedural skills. Thus, students may lack competence to address the psychosocial challenges involved in comprehensive medical care. Social accountability experiential logs were developed for third year medical students at the University of Ottawa to address and intervene on the social determinants of health. Students completed quality improvement surveys and results demonstrated this initiative to be beneficial to their learning and contributed to greater clinical confidence. Experiential logs in clinical training can be adapted across other medical schools and tailored to fit the needs and priorities of each institution’s local communities

Etiology of severe childhood pneumonia in the Gambia, West Africa, determined by conventional and molecular microbiological analyses of lung and pleural aspirate samples.

Molecular analyses of lung aspirates from Gambian children with severe pneumonia detected pathogens more frequently than did culture and showed a predominance of bacteria, principally Streptococcus pneumoniae, >75% being of serotypes covered by current pneumococcal conjugate vaccines. Multiple pathogens were detected frequently, notably Haemophilus influenzae (mostly nontypeable) together with S. pneumoniae

Asymmetric Fluid Criticality I: Scaling with Pressure Mixing

The thermodynamic behavior of a fluid near a vapor-liquid and, hence, asymmetric critical point is discussed within a general ``complete'' scaling theory incorporating pressure mixing in the nonlinear scaling fields as well as corrections to scaling. This theory allows for a Yang-Yang anomaly in which \mu_{\sigma}^{\prime\prime}(T), the second temperature derivative of the chemical potential along the phase boundary, diverges like the specific heat when T\to T_{\scriptsize c}; it also generates a leading singular term, |t|^{2\beta}, in the coexistence curve diameter, where t\equiv (T-T_{\scriptsize c}) /T_{\scriptsize c}. The behavior of various special loci, such as the critical isochore, the critical isotherm, the k-inflection loci, on which \chi^{(k)}\equiv \chi(\rho,T)/\rho^{k} (with \chi = \rho^{2} k_{\scriptsize B}TK_{T}) and C_{V}^{(k)}\equiv C_{V}(\rho,T)/\rho^{k} are maximal at fixed T, is carefully elucidated. These results are useful for analyzing simulations and experiments, since particular, nonuniversal values of k specify loci that approach the critical density most rapidly and reflect the pressure-mixing coefficient. Concrete illustrations are presented for the hard-core square-well fluid and for the restricted primitive model electrolyte. For comparison, a discussion of the classical (or Landau) theory is presented briefly and various interesting loci are determined explicitly and illustrated quantitatively for a van der Waals fluid.Comment: 21 pages in two-column format including 8 figure

The Catalytic Mechanism of a Natural Diels-Alderase Revealed in Molecular Detail

The Diels-Alder reaction, a [4 + 2] cycloaddition of a conjugated diene to a dienophile, is one of the most powerful reactions in synthetic chemistry. Biocatalysts capable of unlocking new and efficient Diels-Alder reactions would have major impact. Here we present a molecular-level description of the reaction mechanism of the spirotetronate cyclase AbyU, an enzyme shown here to be a bona fide natural Diels-Alderase. Using enzyme assays, X-ray crystal structures, and simulations of the reaction in the enzyme, we reveal how linear substrate chains are contorted within the AbyU active site to facilitate a transannular pericyclic reaction. This study provides compelling evidence for the existence of a natural enzyme evolved to catalyze a Diels-Alder reaction and shows how catalysis is achieved

Rates of Dinitrogen Fixation and the Abundance of Diazotrophs in North American Coastal Waters Between Cape Hatteras and Georges Bank

We coupled dinitrogen (N2) fixation rate estimates with molecular biological methods to determine the activity and abundance of diazotrophs in coastal waters along the temperate North American Mid-Atlantic continental shelf during multiple seasons and cruises. Volumetric rates of N2 fixation were as high as 49.8 nmol N L(sup -1) d(sup -1) and areal rates as high as 837.9 micromol N m(sup -2) d(sup -1) in our study area. Our results suggest that N2 fixation occurs at high rates in coastal shelf waters that were previously thought to be unimportant sites of N2 fixation and so were excluded from calculations of pelagic marine N2 fixation. Unicellular N2-fixing group A cyanobacteria were the most abundant diazotrophs in the Atlantic coastal waters and their abundance was comparable to, or higher than, that measured in oceanic regimes where they were discovered. High rates of N2 fixation and the high abundance of diazotrophs along the North American Mid-Atlantic continental shelf highlight the need to revise marine N budgets to include coastal N2 fixation. Integrating areal rates of N2 fixation over the continental shelf area between Cape Hatteras and Nova Scotia, the estimated N2 fixation in this temperate shelf system is about 0.02 Tmol N yr(sup -1), the amount previously calculated for the entire North Atlantic continental shelf. Additional studies should provide spatially, temporally, and seasonally resolved rate estimates from coastal systems to better constrain N inputs via N2 fixation from the neritic zone

Aip3p/Bud6p, a yeast actin-interacting protein that is involved in morphogenesis and the selection of bipolar budding sites.

A search for Saccharomyces cerevisiae proteins that interact with actin in the two-hybrid system and a screen for mutants that affect the bipolar budding pattern identified the same gene, AIP3/BUD6. This gene is not essential for mitotic growth but is necessary for normal morphogenesis. MATa/alpha daughter cells lacking Aip3p place their first buds normally at their distal poles but choose random sites for budding in subsequent cell cycles. This suggests that actin and associated proteins are involved in placing the bipolar positional marker at the division site but not at the distal tip of the daughter cell. In addition, although aip3 mutant cells are not obviously defective in the initial polarization of the cytoskeleton at the time of bud emergence, they appear to lose cytoskeletal polarity as the bud enlarges, resulting in the formation of cells that are larger and rounder than normal. aip3 mutant cells also show inefficient nuclear migration and nuclear division, defects in the organization of the secretory system, and abnormal septation, all defects that presumably reflect the involvement of Aip3p in the organization and/or function of the actin cytoskeleton. The sequence of Aip3p is novel but contains a predicted coiled-coil domain near its C terminus that may mediate the observed homo-oligomerization of the protein. Aip3p shows a distinctive localization pattern that correlates well with its likely sites of action: it appears at the presumptive bud site prior to bud emergence, remains near the tips of small bund, and forms a ring (or pair of rings) in the mother-bud neck that is detectable early in the cell cycle but becomes more prominent prior to cytokinesis. Surprisingly, the localization of Aip3p does not appear to require either polarized actin or the septin proteins of the neck filaments

Predicting the impact of pneumococcal conjugate vaccine programme options in Vietnam.

Although catch-up campaigns (CCs) at the introduction of pneumococcal conjugate vaccines (PCVs) may accelerate their impact, supply constraints may limit their benefit if the need for additional PCV doses results in introduction delay. We studied the impact of PCV13 introduction with and without CC in Nha Trang, Vietnam - a country that has not yet introduced PCV - through a dynamic transmission model. We modelled the impact on carriage and invasive pneumococcal disease (IPD) of routine vaccination (RV) only and that of RV with CCs targeting <1y olds (CC1), <2y olds (CC2) and <5y olds (CC5). The model was fitted to nasopharyngeal carriage data, and post-PCV predictions were based on best estimates of parameters governing post-PCV dynamics. With RV only, elimination in carriage of vaccine-type (VT) serotypes is predicted to occur across all age groups within 10 years after introduction, with near-complete replacement by non-VT. Most of the benefit of CCs is predicted to occur within the first 3 years with the highest impact at one year, when IPD incidence is predicted to be 11% (95%CrI 9 - 14%) lower than RV with CC1, 25% (21 - 30 %) lower with CC2 and 38% (32 - 46%) lower with CC5. However, CCs would only prevent more cases of IPD insofar as such campaigns do not delay introduction by more than about 6, 12 and 18 months for CC1, CC2 and CC5. Those findings are important to help guide vaccine introduction in countries that have not yet introduced PCV, particularly in Asia