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Le régime de Vladimir Poutine est autoritaire et détestable, mais on ne peut le qualifier de fasciste
No full textL’Unité Virtuelle de Soins pour le développement de compétences relatives à la surveillance clinique en contexte de soins critiques : une étude qualitative descriptive
Get PDFIntroduction : La réalité virtuelle (RV) est une méthode pédagogique de plus en plus utilisée pour favoriser l’acquisition de certaines compétences chez les personnes étudiantes en sciences infirmières. Le jugement clinique lors de la surveillance d’une personne soignée en soins critiques est une compétence pouvant être développée grâce à la RV. Toutefois, avant d’intégrer cette méthode pédagogique à la formation infirmière, il est important de s’assurer de l’acceptabilité et de la faisabilité dans un contexte de formation en sciences infirmières. But : Cette étude décrit l’expérience vécue par des personnes étudiantes en sciences infirmières lorsqu’elles ont utilisé l’UVS pour développer leurs compétences en surveillance clinique en contexte de soins critiques. Méthode : Un devis descriptif qualitatif a été utilisé. Des entrevues semi-dirigées ont été menées auprès de 13 personnes participantes provenant de trois universités québécoises ayant vécu une expérience de RV où elles avaient à prendre en charge une personne hémodynamiquement instable. Résultats : Les personnes participantes ont identifié 10 facteurs facilitants et 9 facteurs contraignants quant à l’utilisation de l’UVS comme méthode pédagogique pour développer les connaissances relatives à la surveillance clinique en contexte de soins critiques. Conclusion : L’utilisation de la RV dans la formation infirmière doit tenir compte autant des facteurs facilitants que contraignants afin de rendre l’expérience positive et favoriser son acceptabilité
Analyse des profils génétiques des personnes atteintes de la COVID-19 et évaluation de l’impact de l’asthme sur la sévérité de la maladie
Get PDFLa maladie à coronavirus 2019 (COVID-19) est une infection virale causée par le virus du syndrome respiratoire aigu sévère du coronavirus 2 (SARS-CoV-2). Plusieurs facteurs semblent amplifier la sévérité de cette maladie, y compris les maladies pulmonaires. Des études antérieures ont suggéré un lien potentiel entre la COVID-19 et l’asthme. Plus spécifiquement, il a été démontré que l'asthme non allergique est associé à un risque accru de développer une forme sévère de la COVID-19. En revanche, l'asthme allergique pourrait avoir un effet protecteur. Dans la présente étude, une étude d'association pangénomique (GWAS) a été faite à l’aide des participants de la Biobanque québécoise de la COVID-19 (BQC19) afin d’identifier des variants génétiques associés à la forme sévère de la COVID-19 en comparaison à la forme légère à modérée. Dans un deuxième temps, une analyse a été réalisée afin de comparer le profil génétique des personnes atteintes de COVID-19 sévère avec asthme à celles sans cette comorbidité. Dans un premier temps, la comparaison entre les personnes atteintes de la COVID-19 sévère et celles ayant une forme légère à modérée, a montré que les personnes ayant un phénotype sévère pour la COVID-19 avaient un âge moyen plus élevé, étaient plus souvent de sexe masculin et qu’elles avaient un indice de masse corporelle (IMC) plus élevé. De plus, ces personnes présentaient une neutrophilie et une lymphopénie, ainsi que des niveaux plus élevés de D-dimères et de C-réactive (CRP). L’analyse comparative a aussi démontré une utilisation accrue des inhibiteurs de l'enzyme de conversion de l'angiotensine (IEC) chez les personnes atteintes de la forme sévère de la COVID-19 comparativement aux personnes ayant la forme légère à modérée. De plus, les personnes ayant un asthme concomitant à une forme sévère de COVID-19 présentaient plus fréquemment un IMC supérieur ou égal à 33,70 kg/m² et un taux moins élevé de CRP. L’analyse GWAS a quant à elle permis d'associer sept variants génétiques à la COVID-19 sévère. Un de ces variants (rs5891552) se retrouve sur le gène RP1 axonemal microtubule associated (RP1) qui est impliqué dans certaines infections virales et dans le déclenchement de complications graves de ces maladies. De plus, le variant rs4960330, localisé sur le gène desmoplakin (DSP), mérite une attention particulière étant donné que des études récentes ont montré une augmentation des niveaux de la protéine desmoplakine dans les cas de COVID-19 sévère. Enfin, les analyses réalisées entre les groupes affectés par la COVID-19 sévère, avec et sans asthme, a également révélé quatre autres variants significatifs pour les gènes transmembrane protein with EGF-like and two follistatin-like domains 2 (TMEFF2) et huntingtin interacting protein 1 (HIP1). TMEFF2 a été associé à une éosinophilie chez les personnes asthmatiques sévères, tandis que HIP1 pourrait être impliqué dans l'endocytose du SARS-CoV-2. Cette étude a permis de détecter des variants génétiques associées à la forme sévère de la COVID-19, en prenant compte ou non de l’asthme comme comorbidité. Cependant, des recherches supplémentaires seront requises pour mieux comprendre le rôle de ces variants dans l'évolution de ces maladies
Room-temperature microcapsule-based self-healing and fluorine-free superhydrophobic coating
Get PDFAlong with advancements in materials and processes in the 20th and the 21st century, the demand for new generations of materials with specific functionalities has emerged. Self-healing ability is striking in the current environmental circumstances as far as the demand for prolonging the service lives of products and reducing waste is irresistible. In this paper, the self-healing ability was introduced into a fluorine-free superhydrophobic coating via the incorporation of microcapsules containing a silicone resin (DMS-S12) and catalyst (dibutyltin dilaurate, DBTL) inside poly (melamine urea formaldehyde) shells. The designed self-healing system is aligned with the chemistry of the superhydrophobic coating from two points of view. First, the silicone nature of the coating remains almost unchanged after the healing action. Second, the free ethoxy groups of the superhydrophobic coating can act as bridges linking healed regions and matrix. Synthesized microcapsules showing mean diameters of 18 and 16 µm were sought-after for application in surface coating. The water contact angle on the coating reached 165°, and the contact angle hysteresis value of 3.6° verified the non-wettability of the coating. The self-healing ability of the coating was visually inspected through microscopy imaging. Electrochemical impedance spectroscopy was utilized in quantifying the self-healing ability of the as-prepared coating. The self-healing efficiency of the coating was calculated using charge transfer resistance (Rct) data. Results indicated self-healing efficiency of up to 90% compared with that of a blank superhydrophobic coating. The required time for the sealing of microcracks through self-healing reactions was obtained to be between 24 and 48 h after crack application
Effects of individual and combined additions of transition elements (Zr, Ti and V) on the microstructure stability and elevated-temperature properties of Al–Cu 224 cast alloys
Get PDFThe effects of individual and combined additions of transition elements (TEs) Zr, Ti, and V on the microstructure evolution and elevated-temperature mechanical and creep properties of Al–Cu 224 cast alloys were investigated. All alloys had a mixed precipitate microstructure of θʺ- and θʹ-Al2Cu after T7 heat treatment. During the thermal exposure at 300 °C, θʺ transferred into θʹ as the predominant strengthening phase. The coarsening resistance of θʹ during the thermal exposure and further creep deformation was greatly improved by the addition of TEs. Individually, Zr addition demonstrated the best efficiency in stabilizing θʹ, while the combination of Zr + V and Ti + Zr + V achieved the highest efficiency. The addition of TEs generally improved the yield strength (YS) at 300 °C, and the ZrV and TiZrV alloys achieved the highest YS. A close correlation between the YS and the distribution and thermal stability of θʹ was observed. The creep resistance at elevated temperatures was affected by the thermal stability of θʹ and grain size. Zr-containing alloys (ZrV, Zr, and TiZrV) exhibit superior creep resistance. In terms of comprehensive properties, the combined addition of TiZrV alloy exhibited the best elevated-temperature performance
Performance of seedlings of four coniferous species planted in two boreal lichen woodlands with contrasting soil fertility
No full textLichen woodlands (LWs) are persistent unproductive areas of the Canadian boreal forests whose afforestation may potentially remove significant amounts of anthropogenic C from the atmosphere. The choice of species to be planted is nevertheless uncertain given the particular pedoclimatic conditions prevailing in this habitat as well as the rapidly changing climate at northern latitudes. In this study, we assessed the survival and the growth rates of four boreal coniferous species in two LWs with contrasting soil fertility. Five years after afforestation, survival rate was high for all species at both sites, ranging from 60 to 100 %. Tree height and diameter at stump height (DSH) were up to 60 % and 97 % higher at the LW with higher soil fertility, respectively. The height of jack pine (Pinus banksiana Lamb.; JP) trees was on average 15 %, 56 % and 68 % higher than that of tamarack (Larix laricina [DuRoi] K. Koch; TK), black spruce (Picea mariana [Mill.] BSP; BS) and white spruce (Picea glauca [Moench] Voss; WS), respectively. There was a significant species × soil fertility interaction, reflecting a much higher growth difference between the two sites for JP than for the other species. Annual apical growth increased from one year to the other in JP, suggesting its ability to expand its root system and to acquire resources from the mineral soil rapidly after planting. The much larger photosynthetic biomass at the more fertile site was driven by a higher number of needles produced annually rather than by a higher mass of individual needles, which did not vary between sites. The photosynthetic biomass / woody biomass ratio was not significantly impacted by soil fertility. Overall, these results suggest that JP and TK may be good candidates for the afforestation of boreal LWs and that site selection is of crucial importance to optimize plantation productivity in the mid-term. Further studies must be conducted to assess the survival and the C sequestration potential of these species in the long-term
Hydrophobicity and icephobicity of micropillared silicone rubber surfaces fabricated by compression molding
Get PDFThis study investigates the effects of microcylindrical pillar geometry on surface wettability and ice nucleation time. The cylindrical micropillars were designed and then fabricated on silicone rubber surfaces by micromachining to create a template, followed by direct replication using a compression molding method. This approach offers an efficient, nontoxic, and low-cost means of producing micro-nanoscale roughness on surfaces. We tested the wetting (i.e., contact angle and contact angle hysteresis) and anti-icing (i.e., ice nucleation time) properties of the patterned silicone rubber surfaces having different combinations of pillar diameter and interpillar spacing. According to our experimental results for a limited range of pillar diameters (80 and 110 ) and center to center spacing (pitch; 125–300 ), decreasing the diameter and increasing the space of micro-cylindrical pillars may result in the Cassie wetting until a threshold value. Beyond this pillar diameter/pitch threshold, Wenzel wetting occurred. Surfaces characterized by pillars of different diameter and pitch also increased the freezing delay by reducing the area of ice–substrate contact and the heat transfer between the water droplet and the surface. We demonstrate that the properties of superhydrophobic and anti-icing surfaces can be controlled by altering the geometry of micropillars across the surface
Portrait de la santé mentale des communautés universitaires.
Get PDFCes douze infographies ont été élaborées dans le cadre d’un projet ayant pour titre « Santé mentale et accessibilité en milieu universitaire : la diversité constitue-t-elle une barrière ? ». Jumelant synthèse des écrits et données de recherche, elles visent à effectuer le portrait de la santé mentale des étudiant.es et des employé.es qui s’identifient à l’un ou plusieurs des six groupes désignés suivants : Femmes, minorités visibles, personnes en situation de handicap, personnes autochtones, personnes de la diversité sexuelle et de genre, et personnes de l’international
The thermodynamic stability of the Cassie–Baxter regime determined by the geometric parameters of hierarchical superhydrophobic surfaces
No full textUnderstanding the geometric parameters of hierarchical superhydrophobic surfaces and their impact on the thermodynamic stability of the Cassie-Baxter regime are invaluable for surface wettability–related applications. Herein, we fabricated hierarchical micro-microstructured silicone rubber surfaces having superhydrophobic properties via an industrially applicable direct replication method. The mold inserts were fabricated using photochemical milling, laser ablation, and wet chemical etching to create different hierarchical levels. We calculated surface roughness ratios and equilibrium contact angles and considered the contribution of sub-microstructures in the wettability properties via physical and statistical analyses. Comparing the calculated theoretical wettability properties and experimental measurements revealed a good agreement among all samples because of the accurate predictions of the governing wetting regime. It was worthwhile insights into the design and fabrication of superhydrophobic structured surfaces. The presence of superimposed sub-microstructures produced desirable water-repellency properties because of the reduced solid–liquid contact area as low as 0.086. Given the primary importance of the Cassie–Wenzel wetting transition on the design and fabrication of superhydrophobic surfaces, we evaluated the thermodynamic persistence of the Cassie–Baxter regime by analyzing the energy barrier to be overcome by droplets with various volumes. Finally, we discuss the contribution of the dimensional parameters of microstructures on the stability of the Cassie–Baxter regime
Spatial patterns and climatic drivers of leaf spring phenology of maple in eastern North America
No full textThe resurgent frequency of extreme weather events and their strongly distinctive spatial patterns lead to a growing interest in phenology as an indicator of tree susceptibility. Using a long-term chronology of observations collected in situ, we predicted and investigated the spatial patterns and environmental drivers of spring leaf phenology across maple stand polygons dominated by Acer saccharum Marsh. and/or Acer rubra L. in eastern North America for 2000–2018. Model’ calibration was based on Bayesian ordinal regressions relating the timing of the phenological events' observations to the MODIS vegetation indices EVI, NDVI and LAI. DAYMET data have been extracted to compute temperature and precipitation during spring phenology. Model accuracy increased as the season progressed, with prediction uncertainty spanning from 9 days for bud swelling to 4 days for leaf unfolding. NDVI and LAI were the best predictors for the onset and ending of spring phenology, respectively. Bud swelling occurred at the end of March in the early stands and at the onset of May in the late stands, while leaf unfolding was completed at the beginning of April for the early and in mid-June for the late stands. Early and late stands polarized towards a south-west–north-east gradient. In the south-western regions, which are also the driest, total precipitation and minimum temperature explained respectively 73 % and 25 % of the duration of spring phenology. In the north-eastern regions, precipitation and minimum temperature explained 62 % and 26 % of the duration of spring phenology. Our results suggest high vulnerability to extreme weather events in stands located in the south-west of the species distribution. The increasing incidence of drought in these locations might affect spring phenology, decreasing net primary production in these stands. Warmer nights might expose the buds to late frosts, events that are expected to become more frequent in the coming years