173 research outputs found
Points de contact entre les protéines HMG 1 et 2 et les histones dans la chromatine et leur niveau de poly (ADP-ribosylation)
L'interaction des protĂ©ines 1 et 2 du groupe de mobilitĂ© Ă©lectrophorĂ©tique Ă©levĂ©e (protĂ©ines HMG) avec l'octamĂšre d'histones Ă l'intĂ©rieur du nuclĂ©osome et leur niveau de poly (ADP-ribosylation) ont Ă©tĂ© Ă©tudiĂ©s. Extraite de thymus de lapin et digĂ©rĂ©e par des enzymes, la chromatine a Ă©tĂ© traitĂ©e avec le 1-Ă©thyl-3-(3-dimĂ©thylaminopropyl) carbodiimide, lequel catalyse la formation de liens covalents entre les rĂ©sidus de protĂ©ines en contact. Les produits formĂ©s par la rĂ©action de rĂ©ticulation ont Ă©tĂ© sĂ©parĂ©s sur un systĂšme de gel en deux dimensions acide-urĂ©e/ sodium dodĂ©cyl sulfate (SDS), excisĂ©s et clivĂ©s par une hydrolyse acide partielle. Les constituants peptidiques des bandes dĂ©coupĂ©es ont Ă©tĂ© ensuite identifiĂ©s par Ă©lectrophorĂšse sur gel de polyacrylamide en prĂ©sence de SDS. Les rĂ©sultats montrent que les protĂ©ines HMG 1 et 2 se retrouvent localisĂ©es prĂšs de l'histone H3 Ă l'intĂ©rieur du coeur nuclĂ©osomal. En second lieu, l'interaction des protĂ©ines HMG 1 et 2 (extraites de thymus de veau) avec les histones nuclĂ©osomales a Ă©tĂ© Ă©tudiĂ©e dans un systĂšme reconstituĂ©. Les rĂ©sultats montrent la disparition des produits de rĂ©ticulation constituĂ©s en moitiĂ© de l'histone H1 lors de l'ajout des protĂ©ines HMG 1 et 2. Ceci suggĂšre le dĂ©placement de l'histone H1 par les protĂ©ines HMG 1 et 2 dans la chromatine. Les rĂ©sultats d'expĂ©riences de poly (ADP-ribosylation) montrent que les protĂ©ines HMG 1 et 2 peuvent ĂȘtre mono (ADP-ribosylĂ©es) comme l'est l'histone H1 et qu'elles se retrouvent presque entiĂšrement dans une seule fraction de la chromatine. Les histones du coeur nuclĂ©osomal sont poly (ADP-ribosylĂ©es) dans les mĂȘmes conditions expĂ©rimentale
Suivi des élÚves à risque en lecture : étude longitudinale de la premiÚre à la quatriÚme année
Exploring parameter uncertainty and seasonal variability for human health intake fractions in life cycle assessment:Extended abstract
Regionalized terrestrial ecotoxicity assessment of copper-based fungicides applied in viticulture
Life cycle assessment has been recognized as an important decision-making tool to improve the environmental performance of agricultural systems. Still, there are certain modelling issues related to the assessment of their impacts. The first is linked to the assessment of the metal terrestrial ecotoxicity impact, for which metal speciation in soil is disregarded. In fact, emissions of metals in agricultural systems contribute significantly to the ecotoxic impact, as do copper-based fungicides applied in viticulture to combat downy mildew. Another issue is linked to the ways in which the intrinsic geographical variability of agriculture resulting from the variation of management practices, soil properties, and climate is addressed. The aim of this study is to assess the spatial variability of the terrestrial ecotoxicity impact of copper-based fungicides applied in European vineyards, accounting for both geographical variability in terms of agricultural practice and copper speciation in soil. This first entails the development of regionalized characterization factors (CFs) for the copper used in viticulture and then the application of these CFs to a regionalized life-cycle inventory that considers different management practices, soil properties, and climates in different regions, namely Languedoc-Roussillon (France), Minho (Portugal), Tuscany (Italy), and Galicia (Spain). There are two modelling alternatives to determine metal speciation in terrestrial ecotoxicity: (a) empirical regression models; and (b) WHAM 6.0, the geochemical speciation model applied according to the soil properties of the Harmonized World Soil Database (HWSD). Both approaches were used to compute and compare regionalized CFs with each other and with current IMPACT 2002+ CF. The CFs were then aggregated at different spatial resolutionsâglobal, Europe, country, and wine-growing regionâto assess the uncertainty related to spatial variability at the different scales and applied in the regionalized case study. The global CF computed for copper terrestrial ecotoxicity is around 3.5 orders of magnitude lower than the one from IMPACT 2002+, demonstrating the impact of including metal speciation. For both methods, an increase in the spatial resolution of the CFs translated into a decrease in the spatial variability of the CFs. With the exception of the aggregated CF for Portugal (Minho) at the country level, all the aggregated CFs derived from empirical regression models are greater than the ones derived from the method based on WHAM 6.0 within a range of 0.2 to 1.2 orders of magnitude. Furthermore, CFs calculated with empirical regression models exhibited a greater spatial variability with respect to the CFs derived from WHAM 6.0. The ranking of the impact scores of the analyzed scenarios was mainly determined by the amount of copper applied in each wine-growing region. However, finer spatial resolutions led to an impact score with lower uncertainty
Adhesion of Pathogenic Bacteria to Food Contact Surfaces: Influence of pH of Culture
The adhesion of Aeromonas hydrophila, Escherichia coli O157:H7, Salmonella Enteritidis, and Staphylococcus aureus to hydrophobic and hydrophilic surfaces in cultures with different pHs (6, 7, and 8) was studied. The results indicated that the type of material had no effect on the attachment capacity of microorganisms, while environmental pH influenced the adhesion of A. hydrophila, E. coli, and S. aureus to both solid substrates. The attachment of S. Enteritidis (P > .05) was not affected by the type of substrate or the culture pH, whereas E. coli displayed the weakest affinity for both polystyrene and glass surfaces. No correlation was established between the physicochemical properties of the materials, or the bacterial and the rate of bacterial adhesion, except for S. aureus. Photomicrographs have shown that surfaces were contaminated by small clusters of S. Enteritidis while S. aureus invaded the food contact surfaces in the form of small chains or cell aggregates
Ăvaluation objective structurĂ©e de lâanimation du dĂ©briefing (ĂOSAD) : traduction, adaptation et validation dâune rubrique
Contexteâ: Le dĂ©briefing en simulation clinique requiert des habiletĂ©s dâanimation de la part des formateurs. Bien que des outils dâĂ©valuation validĂ©s existent et pourraient servir Ă leur formation, ils sont uniquement disponibles en anglais et ne sont pas adaptĂ©s Ă la rĂ©alitĂ© quĂ©bĂ©coise. Butâ: (1) Traduire une rubrique dâĂ©valuation de la qualitĂ© de lâanimation du dĂ©briefing (Objective Structured Assessment of Debriefing) en français et lâadapter au contexte quĂ©bĂ©coisâ; et (2) en tester la validitĂ© et la fidĂ©litĂ© dans un contexte de formation en sciences infirmiĂšres. MĂ©thodesâ: La rubrique a Ă©tĂ© traduite et adaptĂ©e par trois traducteurs indĂ©pendants. Des experts en simulation (nâ=â11) en ont validĂ© le contenu selon une mĂ©thode Delphi modifiĂ©e. La rubrique traduite a Ă©tĂ© mise Ă lâessai auprĂšs dâanimateurs en simulation (nâ=â10) qui ont Ă©valuĂ© la qualitĂ© de dĂ©briefings filmĂ©s (nâ=â16). RĂ©sultatsâ: La rubrique prĂ©sente une forte validitĂ© de contenu selon les experts et une forte validitĂ© concomitante en comparaison avec un score dâĂ©valuation gĂ©nĂ©rale du dĂ©briefing. Les rĂ©sultats pour les fidĂ©litĂ©s interjuges et test-retest montrent une variabilitĂ© dans lâattribution des scores par les animateurs de dĂ©briefing. Conclusionâ: La rubrique fournit un langage et des critĂšres communs pour Ă©valuer la qualitĂ© dâanimation des dĂ©briefings. Elle pourrait servir de base Ă la formation des formateurs en prĂ©cisant des critĂšres de performance et des descripteurs reflĂ©tant diffĂ©rents niveaux de performance. Les qualitĂ©s psychomĂ©triques observĂ©es suggĂšrent toutefois quâune formation plus exhaustive et des modifications dans les descripteurs seraient nĂ©cessaires avant que la rubrique ne soit utilisĂ©e en contexte de recherche.Context: Educators must be skilled to facilitate debriefing after healthcare simulations. While tools to assess the quality of debriefing exist and could guide educatorsâ training, they are only available in English and are not adapted to the reality of Quebec. Purpose: (1) To translate a rubric to assess the quality of debriefing (Objective Structured Assessment of Debriefing) in French and adapt it to the context of Quebec; and (2) to test the validity and fidelity of the translated and adapted rubric. Methods: Three independent translators translated and adapted the rubric. Simulation experts (nâ=â11) validated the rubricâs content through a modified Delphi process. The translated rubric was piloted with a sample of simulation educators (nâ=â10) whom assessed the quality of recorded debriefings (nâ=â16). Results: The rubric presented strong content validity according to simulation experts and strong concurrent validity when compared to a general debriefing assessment score. Results for interrater and test-retest reliability showed some variability among educators. Conclusion: The rubric offers a common language and a set of criteria to assess the quality of debriefing. The rubric could guide educatorsâ training by specifying performance criteria and descriptors reflecting various levels of performance. However, results regarding psychometric properties of the rubric suggest that extensive training and some modification to descriptors are required prior to its use as a research instrument
Le compagnonnage cognitif : une approche pédagogique à explorer pour le développement du raisonnement clinique infirmier? - Cognitive Companionship: a potential pedagogical approach to developing clinical reasoning in nursing?
LâĂ©talage des processus cognitifs et mĂ©tacognitifs engagĂ©s chez les expertes dans des situations authentiques de la pratique est peu exposĂ© ou exploitĂ© dans la formation infirmiĂšre : les Ă©tudiantes y accĂšdent rarement ou sporadiquement. En dâautres mots, le savoir tacite dĂ©veloppĂ© chez les expertes demeure trop souvent silencieux et les Ă©tudiantes nâobtiennent pas dâexplication, de justification ou dâarticulation intentionnelle des hypothĂšses et des interventions cliniques avancĂ©es par les expertes dans des situations authentiques de la pratique professionnelle. DĂšs lors, comment mieux tirer profit du raisonnement clinique infirmier des expertes et crĂ©er un mode dâaccompagnement pour lâapprentissage de la compĂ©tence ? Le but de cet article est d\u27explorer le compagnonnage cognitif comme approche pĂ©dagogique au dĂ©veloppement du raisonnement clinique infirmier. Plus prĂ©cisĂ©ment, les fondements Ă©pistĂ©mologiques et thĂ©oriques sont explicitĂ©s afin de saisir les principes pĂ©dagogiques qui sous-tendent lâapplication et la contribution potentielle du compagnonnage cognitif au dĂ©veloppement de la compĂ©tence.
Lâapport de cet article repose sur une conceptualisation riche des fondements thĂ©oriques qui guident les stratĂ©gies pĂ©dagogiques Ă mettre en Ćuvre dans les programmes de formation infirmiĂšre et qui pourraient ĂȘtre contributives au dĂ©veloppement du raisonnement clinique infirmier. DiffĂ©rentes stratĂ©gies sont Ă©numĂ©rĂ©es et exemplifiĂ©es par les auteurs afin dâoutiller les milieux acadĂ©miques et les milieux cliniques face Ă lâutilisation du compagnonnage cognitif. Ces stratĂ©gies permettent dâillustrer le compagnonnage cognitif dans diffĂ©rentes situations dâapprentissage/enseignement notamment le prĂ©ceptorat, la simulation clinique ou lâutilisation de supports numĂ©riques Ă lâapprentissage. AncrĂ©es dans une approche sociocognitiviste, ces stratĂ©gies sollicitent lâarticulation des connaissances, la rĂ©flexion ainsi que le dialogue cognitif socialement partagĂ© et liĂ© Ă une situation authentique de la pratique professionnelle. Le compagnonnage cognitif permet de capter les « savoirs-vivants» des expertes, ces savoirs spĂ©cialisĂ©s et construits par la pratique, mais qui demeurent difficilement traduits dans les ouvrages de rĂ©fĂ©rence. Le compagnonnage cognitif suggĂšre ainsi un accompagnement propice au dĂ©veloppement du raisonnement clinique infirmier. Ultimement, cette approche pourrait contribuer Ă une culture de dĂ©veloppement professionnel tout en favorisant lâapport dâune communautĂ© dâapprentissage. Les auteurs proposent la conduite de recherches et d\u27interventions pĂ©dagogiques afin dâĂ©tablir un lien cohĂ©rent entre lâapproche du compagnonnage cognitif, les stratĂ©gies utilisĂ©es et le dĂ©veloppement de la compĂ©tence.
Abstract
The cognitive and metacognitive processes favoured by experts in real practice situations are rarely evoked or called upon in nursing education. Students, in fact, are only exposed to these concepts very rarely or sporadically, if at all. As a result, the tacit knowledge acquired by experts is too often kept under wraps, effectively preventing students from obtaining explanations, reasons or clear precisions regarding the clinical assumptions and interventions discussed by experts during real practice situations. This begs the question of how to reap the benefits of the clinical reasoning adopted by experts to design a companionship method for improving student learning in the area of nursing competency. This article explores cognitive companionship as an educational approach to developing such clinical reasoning. More specifically, theoretical and epistemological foundations are discussed in detail to allow for a better understanding of the educational principles underlying the application and possible contribution of cognitive companionship to competency development.
The content of this article consists of a thorough conceptualization of the theoretical underpinnings of the educational strategies to incorporate into nursing education programs, in the hopes that they will favour the development of clinical reasoning in nursing. The authors have identified and expanded upon various educational strategies for preparing academic and clinical settings for the eventual use of cognitive companionship. These strategies illustrate the uses of cognitive companionship in various learning/teaching situations (specifically, preceptorship programs, clinical simulations or learning through e-learning environments). Rooted in a socio-cognitive approach, they rely on the articulation of knowledge, reflection and a cognitive dialogue that is both socially shared and linked to real practice situations. Cognitive companionship makes it possible to understand the living knowledge of experts, a specialized knowledge that grows with practice, but which is hard to put to paper in reference works. Cognitive companionship also relies on an approach suitable to the development of clinical reasoning in nursing. Ultimately, this approach could foster a professional development culture supported by an entire learning community. The authors suggest carrying out research and academic activities to identify a consistent link between the cognitive companionship approach, the related educational strategies and development of the desired competence
Quelques principes pour concevoir et Ă©valuer des activitĂ©s dâapprentissage en formation Ă distance
Lire pour apprendre est particuliĂšrement important en formation Ă distance oĂč lâimprimĂ© constitue le mĂ©dia privilĂ©giĂ© pour transmettre les connaissances. Pour sâassurer que lâapprentissage se produise, il faut se fier Ă la compĂ©tence des lecteurs, Ă la qualitĂ© des textes ou Ă la qualitĂ© des activitĂ©s qui accompagnent ces textes. Or, on a constatĂ© que les apprenants utilisent peu de stratĂ©gies de lecture ou de comprĂ©hension, que la majoritĂ© des textes soumis aux apprenants sont de piĂštre qualitĂ© et que les activitĂ©s proposĂ©es ne favorisent pas un traitement en profondeur des informations. La mise en place dâactivitĂ©s dâapprentissage de qualitĂ© apparaĂźt comme une solution qui peut rĂ©mĂ©dier Ă ces difficul- tĂ©s. Il importe alors de se donner des outils pour sĂ©lectionner, concevoir ou Ă©valuer les activitĂ©s dâapprentissage que lâon veut suggĂ©rer aux apprenants. En nous appuyant sur les travaux rĂ©cents en psychologie cognitive, ceux en apprentissage en gĂ©nĂ©ral et ceux portant sur lâapprentissage auto-rĂ©gulĂ© (self-regulated learning), nous suggĂ©rons cinq principes pour quider les concepteurs dans leur tĂąche de production dâactivitĂ©s dâapprentissage. Ces principes sont les suivants: 1) les activitĂ©s doivent permettre un engagement cognitif, affectif et mĂ©tacognitif des apprenants; 2) les activitĂ©s doivent favoriser un apprentissage âcontextualisĂ©â; 3) les activitĂ©s de type cognitif doivent proposer un traitement en profondeur des informations Ă acquĂ©rir; 4) les activitĂ©s de type mĂ©tacognitif doivent proposer une dĂ©marche dâapprentissage autogĂ©rĂ©e; 5) les activitĂ©s de type affectif doivent tenir compte des connaissances et des expĂ©riences des apprenants. Reading has particular importance in distance education, where print is especially important. If readers are to learn âat a distance,â we must hope for their competence, or depend on the quality of text or of its accompanying activities. Learners, however, deploy few reading or comprehension strategies; most texts are dreadful; and most activities in distance education do not lead to critical thinking. Using recent work in cognitive psychology, on learning generally, and on self-regulated learning, we suggest five guiding principles for appropriate learning activities: (1) activities should invite cognitive, meta- cognitive, and affective engagement; (2) activities should favour contextualized learning; (3) cognitive activities should lead to analytical treatment of information; (4) metacogni- tive activities should have self-directed learning as means and ends; and (5) affective activities should take into account learnersâ knowledge and experience.
Theoretical foundations of educational strategies used in e-learning environments for developing clinical reasoning in nursing students : a scoping review
E-learning environments expand opportunities for the use of educational strategies that may contribute to the development of clinical reasoning in nursing students. The purposes of this scoping review were the following: 1) to map the principles of cognitive companionship and the theoretical foundations underlying the design and implementation of educational strategies used in e-learning environments for developing clinical reasoning in nursing students; and 2) to identify the types of educational strategies used in e-learning environments for developing or assessing clinical reasoning in nursing students. A scoping review was conducted and was based on the Joanna Briggs Institute Framework. Bibliographical databases were searched for studies published between January 2010 to July 2017. Out of 1202 screened articles, 18 met eligibility criteria and were included in this review. Principles of cognitive companionship in e-learning environments provide key clues from a learning support perspective, such as integrated feedback, interactive group discussion, gaming, and questioning. However, theoretical foundations underlying educational strategies in e-learning environments are poorly documented and insufficiently associated with cognitive learning models. E-learning environments must have solid theoretical foundations to provide support for the development of CR in nursing students
Ătude de l'effet d'insaturation dans les mĂ©thylĂšnecyclohexanes substituĂ©s Ă la position 2 par des groupements OXY insaturĂ©s
Dans le but d'obtenir des informations sur la nature des facteurs pouvant provoquer l'effet d'insaturation dans les oxy-2 mĂ©thylĂšnecyclohexanes nous avons procĂ©dĂ© Ă l'Ă©tude cinĂ©tique du rĂ©arrangement de Claisen des cis et trans t-butyl-4 phĂ©noxy-2 mĂ©thylĂšnecyclohexanes ainsi qu'Ă l'analyse des barriĂšres d'inversion des conformĂšres axiaux et Ă©quatoriaux de plusieurs mĂ©thylĂšnecyclohexanes substituĂ©s Ă la position 2. Les produits que nous avons synthĂ©tisĂ©s ont Ă©tĂ© prĂ©parĂ©s par des mĂ©thodes connues. Les rĂ©sultats cinĂ©tiques ont Ă©tĂ© obtenus par rĂ©action en tubes scellĂ©s suivie d'une analyse chromatographique en phase vapeur sur colonne capillaire. L'analyse conformationnelle a Ă©tĂ© effectuĂ©e par rĂ©sonance magnĂ©tique nuclĂ©aire du carbone 13. Les valeurs d'Ă©quilibre conformationnel ont Ă©tĂ© estimĂ©es qualitativement par la mĂ©thode d'intensitĂ© de pic Ă basse tempĂ©rature. Les barriĂšres d'interconversion des conformĂšres axiaux et Ă©quatoriaux (formes chaise) ont Ă©tĂ© Ă©valuĂ©es Ă la tempĂ©rature de coalescence par des mĂ©thodes RMN13c Ă tempĂ©rature variable. Les rĂ©sultats obtenus nous ont amenĂ©s Ă constater que l'interaction orbitalaire (formule : voir document) n'affecte pas l'Ă©quilibre conformationnel des mĂ©thylĂšnecyclohexanes portant un substituant oxy insaturĂ© Ă la position 2. Par ailleurs, l'analyse des Ă©nergies libres d'interconversion semble dĂ©montrer que dans ces structures, l'interaction (formule : voir document) est relativement faible, qu'elle est annulĂ©e par l'interaction H-no existant dans la conformation axiale et qu'elle n'a pas d'influence dĂ©terminante sur l'Ă©nergie du conformĂšre axial (que le substituant oxy soit insaturĂ© ou non). Cependant, les calculs rĂ©alisĂ©s ont permis de mettre en Ă©vidence la contribution importante d'interactions qui provoqueraient la dĂ©stabilisation du conformĂšre Ă©quatorial. Il s'agirait d'interactions impliquant principalement les orbitales no de l'oxygĂšne du groupement oxy et le systĂšme insaturĂ© exocyclique. L'existence de telles interactions dans ces composĂ©s permet de rationaliser l'effet d'insaturation. Par analogie, l'hypothĂšse que des interactions du mĂȘme type puisse Ă©galement perturber la conformation Ă©quatoriale dans les oxy-2 cyclohexanones explique pourquoi nous observons Ă©galement l'effet d'insaturation pour ces produits. La nature et la contribution des interactions influençant l'Ă©quilibre conformationnel de oxy-2 mĂ©thylĂšnecyclohexanes ont pu ĂȘtre discernĂ©es grĂące au dĂ©veloppement d'un modĂšle d'analyse des barriĂšres d'inversion des conformĂšres axial et Ă©quatorial. Ce modĂšle est basĂ© sur l'hypothĂšse que dans les mĂ©thylĂšnecyclohexanes substituĂ©s Ă la position 2, la perturbation subie par l'Ă©tat de transition de plus grande Ă©nergie est Ă peu prĂšs Ă©quivalente Ă la somme des effets influençant l'Ă©nergie de chacune des formes chaise
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