Le langage non-verbal de l’enseignant: Sa perception par les élèves

Dans ce travail, nous nous sommes intéressés à comprendre comment un élève se construit une opinion au sujet de la personnalité de son nouveau professeur, lorsque celui-ci franchit le seuil de sa classe pour la première fois. Nous avons tout d’abord rappelé les principes fondamentaux de la communication, en insistant principalement sur les éléments du discours non-verbal, dans la perspective particulière de l’enseignement. Nous avons ensuite élaboré un dispositif expérimental au cours duquel dix élèves de classe 6 H ont visionné, sur écran, l’entrée en classe de différents enseignants. A partir d’un entretien individuel et d’un questionnaire, nous avons récolté une certaine masse d’informations que nous avons triées. Présentés sous forme de graphes, les résultats nous ont permis de montrer que l’apparence extérieure, la démarche et la mimique sont les éléments qui, pour ce groupe d’élève, ont le plus influencé leur perception

Calcicole plant diversity in Switzerland may reflect a variety of habitat templets

The study of the disparity concerning the sizes of calcicole and calcifuge floras in Central Europe is a surprisingly young scientific branch. Accordingly, explanations of the patterns have not yet been consolidated. In this paper, we comment on the solution of the "calcareous riddle' proposed by JörgEwald (Folia Geobot. 38: 357-366, 2003). On the basis of flora and vegetation data bases, we tested the phenomenon of calcicole richness by analyzing the forest vegetation and the flora of Switzerland and found corresponding patterns. A clear overbalance of calcareous forest habitats contrasts with an overbalance of acidic topsoils, as derived from a large representative sample in Swiss forests. Calcicole/calcifuge ratios reveal an overbalance of calcicoles in most mapping units of the distribution atlas of vascular plants in Switzerland. Central crystalline parts of the Alps, however, show a clear overbalance of calcifuges. Patterns from the different community and regional scales are explained by (micro-)habitat diversity. With respect to the "calcareous riddle”, we question several assumptions, e.g. the time considered before the Pleistocene bottleneck, the area considered for speciation/extinction, and the role of habitat diversity rather than two substrate classe

ICU research: the impact of invasiveness on informed consent

Purpose: Studies into the preferences of patients and relatives regarding informed consent for intensive care unit (ICU) research are ongoing. We investigated the impact of a study's invasiveness on the choice of who should give consent and on the modalities of informed consent. Methods: At ICU discharge, randomized pairs of patients and relatives were asked to answer a questionnaire about informed consent for research. One group received a vignette of a noninvasive study; the other, of an invasive study. Each study comprised two scenarios, featuring either a conscious or unconscious patient. Multivariate models assessed independent factors related to their preferences. Results: A total of 185 patients (40%) and 125 relatives (68%) responded. The invasiveness of a study had no impact on which people were chosen to give consent. This increased the desire to get more than one person to give consent and decreased the acceptance of deferred or two-step consent. Up to 31% of both patients and relatives chose people other than the patient himself to give consent, even when the patient was conscious. A range of 3 to 17% of the respondents reported that they would accept a waiving of consent. Younger respondents and individuals feeling coerced into study participation wanted to be the decision makers. Conclusions: Study invasiveness had no impact on patients' and relatives' preferences about who should give consent. Many patients and relatives were reluctant to give consent alone. Deferred and two-step consent were less acceptable for the invasive study. Further work should investigate whether sharing the burden of informed consent with a second person facilitates participation in ICU researc

Rotary engine cooling system

A rotary engine has a substantially trochoidal-shaped housing cavity in which a rotor planetates. A cooling system for the engine directs coolant along a single series path consisting of series connected groups of passages. Coolant enters near the intake port, passes downwardly and axially through the cooler regions of the engine, then passes upwardly and axially through the hotter regions. By first flowing through the coolest regions, coolant pressure is reduced, thus reducing the saturation temperature of the coolant and thereby enhancing the nucleate boiling heat transfer mechanism which predominates in the high heat flux region of the engine during high power level operation

Schlüssel zur Einteilung von Neophyten in der Schweiz in die Schwarze Liste oder die Watch-Liste

No Abstrac

Rotational fallows as overwintering habitat for grassland arthropods: the case of spiders in fen meadows

Regular mowing of grassland is often necessary for plant conservation, but uncut vegetation is needed by many arthropods for overwintering. This may lead to conflicting management strategies for plant and arthropod conservation. Rotational fallows are a possible solution. They provide a spatio-temporal mosaic of mown and unmown areas that may combine benefits to both plants and arthropods. We tested if rotational fallows enhance spider overwintering in fen meadows. Rotational fallows consisted of three adjoining strips 10m wide and 35-50m long. Each year, one of these strips was left unmown (fallow) in an alternating manner so that each strip was mown two out of three years. Spiders were sampled during spring with emergence traps in nine pairs of currently unmown fallow strips and completely mown reference plots. Fallows significantly enhanced orb-weavers (Araneidae), sac spiders (Clubionidae) and ground spiders (Gnaphosidae). However, only 4.7% of the total variation in community composition was attributable to fallows. Community variation was larger between landscapes (34.5%) and sites (38.2%). Also β diversity was much higher between landscapes (45 species) and sites (22 species) than between fallows and mown reference plots (10 species). We conclude that the first priority for spider conservation is to preserve as many fen meadows in different landscapes as possible. Locally, rotational fallows enhance overwintering of the above-mentioned spider families, which are sensitive to mowing in other grassland types as well. Thus, rotational fallows would probably foster spider conservation in a wide range of situations. However, stronger effects can be expected from larger and/or older fallow area

Effets des racines, des vers de terre et du compost sur les propriétés physiques de technosols construits

Les technosols construits sont une alternative au prélèvement de terre végétale en milieu naturel. La gestion durable de ces technosols suppose de comprendre l'évolution de leurs propriétés hydriques. Nous avons analysé les courbes de retrait de technosols dont la teneur en compost varie de 0 à 50%, en présence ou non de plantes et/ou de vers de terre. Les résultats montrent que ces organismes expliquent plus la variance (19%) des propriétés hydriques du sol que la dose de compost (14%). Le compost et les plantes jouent un rôle positif sur l'eau disponible présente à la fois dans la macroporosité et dans la microporosité, les vers de terre jouant un rôle positif uniquement sur cette dernière. L'effet conjoint des organismes et du compost explique davantage la variance ( 40%) que les effets simples de ces facteurs. En règle générale, l'effet simple du compost est inférieur à celui des plantes et des vers