La métaphysique de la création : Jean Ladrière interprète de Thomas d’Aquin

Au nombre des sources philosophiques majeures de l’oeuvre de Jean Ladrière se trouve celle de Thomas d’Aquin. La notion de création est l’un des lieux où cette influence se laisse voir de manière particulièrement prégnante. Le traitement ladriérien se présente comme une reprise herméneutique de la doctrine thomiste de la création à la lumière des développements contemporains de la science. Cet article se propose de manifester les axes directeurs de cette réinterprétation.Among the major philosophical sources for the work of Jean Ladrière, one must count Thomas Aquinas. The notion of creation is one where this influence can be detected in an especially pregnant way. Ladrière’s treatment takes on the guise of an hermeneutics of Aquinas’ doctrine of creation in the light of contemporary scientific developments. This article attempts to retrace the main lines of that reinterpretation

L’université comme enjeu de la rencontre du theion et du logos

Ce qui définit la tradition intellectuelle, voire culturelle, occidentale en sa fibre la plus essentielle, est le pari de penser ensemble ces deux dimensions constitutives de l’existence que sont le theion (le «divin») et le logos . Un regard superficiel sur notre histoire pourrait faire croire à l’épuisement de ce pari originaire. Il n’a au contraire jamais été plus urgent et nécessaire en raison de notre situation historique marquée par un vaste processus de réinterprétation du religieux. Le lieu premier où se pose la question du logos et du theion est ainsi celle de la «relève» du théologique classique. C’est cette persistance en acte de réorganisation, cet impératif d’une intelligence «post-religieuse» du sens qu’il s’agit pour la raison d’accompagner et qui justifie la reconduction contemporaine du couple logo s/ theion en pleine chair(e) universitaire.Our Western intellectual and cultural tradition is built upon an initial wager i.e. to think together theion and logos as two fundamental features of human existence. One must conclude that this wager is more relevant than ever, as our age is witnessing a dramatic process of reinterpretation of the traditional understanding of religion. The question about the relationship between logos and theion then becomes: what will replace this traditional content? The urgency to address intellectually this reinterpreation of religion as well as the necessity to address the question of meaning in a post-religious fashion justifies the preservation of the initial relationship between logos and theion in the institutional academic circles

Au croisement de l’universel et du particulier : l’éthique selon Jean Ladrière

L’article se propose de présenter l’éthique philosophique de Jean Ladrière comme une recherche de croisement entre ces deux dimensions constitutives de l’expérience éthique que sont les points de vue universel et existentiel. On couvrira pour ce faire toute l’étendue de la démarche éthique, telle que Ladrière la déploie depuis l’expérience pré-réflexive jusqu’à la détermination effective de l’action en regard d’une situation particulière. Dans cette perspective, l’éthique philosophique apparaît arc-boutée à la fois à l’universalité de la normativité immanente à l’action et à la singularité existentielle d’une destinée unique.This paper shows how Jean Ladrière’s ethics can be understood as an attempt to make the two basic dimensions of ethics, namely the universal and the particular, intersect. We will thus address the whole ethical spectrum, from pre-reflexive experience up to the effective course of action in relation to a particular situation. From this perspective, ethics thus appears altogether rooted in the universality pertaining to the immanent normativity of action as well as the existential singularity of each individual destiny

Pouvons-nous réduire la dose d’azote après un retour de prairie?

Affiche présentée dans le cadre du Colloque de l'ARC, «Des racines et des ailes pour la recherche collégiale», dans le cadre du 85e Congrès de l’Acfas, Université McGill, Montréal, les 8 et 9 mai 2017.Au Québec, les émissions de gaz à effet de serre (GES) d’origine agricole représentent près de 8 % des émissions totales. Environ 40 % des émissions agricoles découle de l’usage des engrais minéraux et des engrais de ferme. Tout apport excédentaire d’engrais azoté dans les cultures se traduit par des émissions supplémentaires d’oxyde nitreux (N2O), un puissant gaz à effet de serre qui contribue aux émissions de GES. Plusieurs études ont démontré que la culture de maïs n’avait pas besoin d’apports importants d’azote en postlevée, après des retours de prairie. En collaboration avec des producteurs agricoles, 16 sites d’essais de fertilisation azotée ont été implantés sur des retours de prairie ayant reçu des engrais de ferme. Les traitements consistaient à apporter 4 doses d’azote minéral (0, 40, 80 et 120 kg N/ha). La teneur en nitrates du sol ainsi que les rendements à la récolte ont été évalués. La teneur en nitrates a confirmé l’effet significatif de la prairie et des engrais de ferme sur la teneur en azote disponible pour le maïs. L’apport d’azote minéral n’a pas eu d’effet significatif sur les rendements en azote, à l’exception d’un site. Le maïs cultivé sur un retour de prairie ne nécessite pas un ajout d’engrais minéral. Éliminer l’apport d’azote réduit tant les émissions de GES que les dépenses en engrais pour les producteurs

Income inequality, gene expression, and brain maturation during adolescence

Income inequality is associated with poor health and social outcomes. Negative social comparisons and competition may involve the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes in underlying some of these complex inter-relationships. Here we investigate brain maturation, indexed by age-related decreases in cortical thickness, in adolescents living in neighborhoods with differing levels of income inequality and household income. We examine whether inter-regional variations relate to those in glucocorticoid receptor (HPA) and androgen receptor (HPG) gene expression. For each sex, we used a median split of income inequality and household income (income-to-needs ratio) to create four subgroups. In female adolescents, the high-inequality low-income group displayed the greatest age-related decreases in cortical thickness. In this group, expression of glucocorticoid and androgen receptor genes explained the most variance in these age-related decreases in thickness across the cortex. We speculate that female adolescents living in high-inequality neighborhoods and low-income households may experience greater HPA and HPG activity, leading to steeper decreases in cortical thickness with age

Prenatal exposure to maternal cigarette smoking, amygdala volume, and fat intake in adolescence

Context : Prenatal exposure to maternal cigarette smoking is a well-established risk factor for obesity, but the underlying mechanisms are not known. Preference for fatty foods, regulated in part by the brain reward system, may contribute to the development of obesity. Objective : To examine whether prenatal exposure to maternal cigarette smoking is associated with enhanced fat intake and risk for obesity, and whether these associations may be related to subtle structural variations in brain regions involved in reward processing. Design : Cross-sectional study of a population-based cohort. Setting : The Saguenay Youth Study, Quebec, Canada. Participants : A total of 378 adolescents (aged 13 to 19 years; Tanner stage 4 and 5 of sexual maturation), half of whom were exposed prenatally to maternal cigarette smoking (mean [SD], 11.1 [6.8] cigarettes/d). Main Outcome Measures : Fat intake was assessed with a 24-hour food recall (percentage of energy intake consumed as fat). Body adiposity was measured with anthropometry and multifrequency bioimpedance. Volumes of key brain structures involved in reward processing, namely the amygdala, nucleus accumbens, and orbitofrontal cortex, were measured with magnetic resonance imaging. Results : Exposed vs nonexposed subjects exhibited a higher total body fat (by approximately 1.7 kg; P = .009) and fat intake (by 2.7%; P = .001). They also exhibited a lower volume of the amygdala (by 95 mm3; P < .001) but not of the other 2 brain structures. Consistent with its possible role in limiting fat intake, amygdala volume correlated inversely with fat intake (r = −0.15; P = .006). Conclusions : Prenatal exposure to maternal cigarette smoking may promote obesity by enhancing dietary preference for fat, and this effect may be mediated in part through subtle structural variations in the amygdala

Growth of white matter in the adolescent brain: role of testosterone and androgen receptor

The growth of white matter during human adolescence shows a striking sexual dimorphism; the volume of white matter increases with age slightly in girls and steeply in boys. Here, we provide evidence supporting the role of androgen receptor (AR) in mediating the effect of testosterone on white matter. In a large sample of typically developing adolescents (n = 408, 204 males), we used magnetic resonance imaging and acquired T1-weighted and magnetization transfer ratio (MTR) images. We also measured plasma levels of testosterone and genotyped a functional polymorphism in the AR gene, namely the number of CAG repeats in exon 1 believed to be inversely proportional to the AR transcriptional activity. We found that the testosterone-related increase of white-matter volume was stronger in male adolescents with the lower versus higher number of CAG repeats in the AR gene, with testosterone explaining, respectively, 26 and 8% of variance in the volume. The MTR results suggest that this growth is not related to myelination; the MTR decreased with age in male adolescents. We speculate that testosterone affects axonal caliber rather than the thickness of the myelin sheath

Orbitofrontal cortex and drug use during adolescence : role of prenatal exposure to maternal smoking and BDNF genotype

Context : Prenatal exposure to maternal cigarette smoking (PEMCS) may affect brain development and behavior in adolescent offspring. Objective : To evaluate the involvement of the orbitofrontal cortex (OFC) in mediating the relationship between PEMCS and substance use. Design : Cross-sectional analyses from the Saguenay Youth Study aimed at evaluating the effects of PEMCS on brain development and behavior among adolescents. Nonexposed adolescents were matched with adolescents exposed prenatally to cigarette smoking by maternal educational level. Participants and Setting : A French Canadian founder population of the Saguenay–Lac-Saint-Jean region of Quebec, Canada.The behavioral data set included 597 adolescents (275 sibships; 12-18 years of age), half of whom were exposed in utero to maternal cigarette smoking. Analysis of cortical thickness and genotyping were performed using available data from 314 adolescents. Main Outcome Measures : The likelihood of substance use was assessed with the Diagnostic Interview Schedule for Children Predictive Scales. The number of different drugs tried by each adolescent was assessed using another questionnaire. Thickness of the OFC was estimated from T1-weighted magnetic resonance images using FreeSurfer software. Results : Prenatal exposure to maternal cigarette smoking is associated with an increased likelihood of substance use. Among exposed adolescents, the likelihood of drug experimentation correlates with the degree of OFC thinning. In nonexposed adolescents, the thickness of the OFC increases as a function of the number of drugs tried. The latter effect is moderated by a brain-derived neurotrophic factor (BDNF) genotype (Val66Met). Conclusions : We speculate that PEMCS interferes with the development of the OFC and, in turn, increases the likelihood of drug use among adolescents. In contrast, we suggest that, among nonexposed adolescents, drug experimentation influences the OFC thickness via processes akin to experience-induced plasticity

Vibration-induced postural reactions: a scoping review on parameters and populations studied

ObjectiveMechanical vibration is an effective way for externally activating Ia primary endings of the muscle spindles and skin mechanoreceptors. Despite its popularity in proprioception and postural control studies, there is still no review covering the wide variety of vibration parameters or locations used in studies. The main purpose of this scoping review was thus to give an overview of general vibration parameters and to identify, if available, the rationale for justifying methodological choices concerning vibration parameters.MethodsThree databases (Pubmed, CINHAL, and SPORTDiscus) were searched from inception to July 2022. Included articles were to focus on the study of muscle spindles and skin mechanoreceptors vibration in humans and assess postural control. Following inclusion, data regarding demographic information, populations, vibration parameters and rationale were extracted and summarized.ResultsOne hundred forty-seven articles were included, mostly targeting lower extremities (n = 137) and adults (n = 126). The parameters used varied widely but were most often around 80 Hz, at an amplitude of 1 mm for 10–20 s. Regarding rationales, nearly 50% of the studies did not include any, whereas those including one mainly cited the same two studies, without elaborating specifically on the parameter's choice.ConclusionThis scoping review provided a comprehensive description of the population recruited and parameters used for vibration protocols in current studies with humans. Despite many studies, there remain important gaps of knowledge that needs to be filled, especially for vibration amplitude and duration parameters in various populations

Effectiveness of a training program in supervisors' ability to provide feedback on residents' communication skills

Teaching communication skills (CS) to residents during clinical practice remains problematic. Direct observation followed by feedback is a powerful way to teach CS in clinical practice. However, little is known about the effect of training on feedback skills in this field. Controlled studies are scarce as well as studies that go beyond self-reported data. The aim of the study was to develop and assess the effectiveness of a training program for clinical supervisors on how to give feedback on residents' CS in clinical practice. The authors designed a pretest-posttest controlled study in which clinical supervisors working in two different medical services were invited to attend a sequenced and multifaceted program in teaching CS over a period of 6-9months. Outcome measures were self-perceived and observed feedback skills collected during questionnaires and three videotaped objective structured teaching encounters. The videotaped feedbacks made by the supervisors were analysed using a 20-item feedback rating instrument. Forty-eight clinical supervisors participated (28 in the intervention, 20 in the control group). After training, a higher percentage of trained participants self-reported and demonstrated statistically significant improvement in making residents more active by exploring residents' needs, stimulating self-assessment, and using role playing to test strategies and checking understanding, with effect sizes ranging from 0.93 to 4.94. A training program on how to give feedback on residents' communication skills was successful in improving clinical supervisors' feedback skills and in helping them operate a shift from a teacher-centered to a more learner-centered approac