Comment aborder les nouvelles notions de mathématiques avec les élèves pour une meilleure assimilation

Professorat des collèges et lycéesCe mémoire s’intéresse aux différentes méthodes que l’on peut utiliser pour rendre l’apprentissage des élèves plus efficace. Il met en avant l’importance de donner du sens lors de l’apprentissage des mathématiques, de rendre les élèves acteurs de leur scolarité mathématique, et enfin de traiter les erreurs commises pour les utiliser au lieu de les évincer. Ce mémoire aborde différentes méthodes mettant en avant ces trois points clés de l’apprentissage

Camk2a-Cre and Tshz3 Expression in Mouse Striatal Cholinergic Interneurons: Implications for Autism Spectrum Disorder

International audienceCamk2a-Cre mice have been widely used to study the postnatal function of several genes in forebrain projection neurons, including cortical projection neurons (CPNs) and striatal medium-sized spiny neurons (MSNs). We linked heterozygous deletion of TSHZ3/Tshz3 gene to autism spectrum disorder (ASD) and used Camk2a-Cre mice to investigate the postnatal function of Tshz3, which is expressed by CPNs but not MSNs. Recently, single-cell transcriptomics of the adult mouse striatum revealed the expression of Camk2a in interneurons and showed Tshz3 expression in striatal cholinergic interneurons (SCINs), which are attracting increasing interest in the field of ASD. These data and the phenotypic similarity between the mice with Tshz3 haploinsufficiency and Camk2a-Cre-dependent conditional deletion of Tshz3 (Camk2a-cKO) prompted us to better characterize the expression of Tshz3 and the activity of Camk2a-Cre transgene in the striatum. Here, we show that the great majority of Tshz3expressing cells are SCINs and that all SCINs express Tshz3. Using lineage tracing, we demonstrate that the Camk2a-Cre transgene is expressed in the SCIN lineage where it can efficiently elicit the deletion of the Tshz3-floxed allele. Moreover, transcriptomic and bioinformatic analysis in Camk2a-cKO mice showed dysregulated striatal expression of a number of genes, including genes whose human orthologues are associated with ASD and synaptic signaling. These findings identifying the expression of the Camk2a-Cre transgene in SCINs lineage lead to a reappraisal of the interpretation of experiments using Camk2a-Cre-dependent gene manipulations. They are also useful to decipher the cellular and molecular substrates of the ASD-related behavioral abnormalities observed in Tshz3 mouse models

PROCUSTE1 Encodes a Cellulose Synthase Required for Normal Cell Elongation Specifically in Roots and Dark-Grown Hypocotyls of Arabidopsis

Mutants at the PROCUSTE1 (PRC1) locus show decreased cell elongation, specifically in roots and dark-grown hypocotyls. Cell elongation defects are correlated with a cellulose deficiency and the presence of gapped walls. Map-based cloning of PRC1 reveals that it encodes a member (CesA6) of the cellulose synthase catalytic subunit family, of which at least nine other members exist in Arabidopsis. Mutations in another family member, RSW1 (CesA1), cause similar cell wall defects in all cell types, including those in hypocotyls and roots, suggesting that cellulose synthesis in these organs requires the coordinated expression of at least two distinct cellulose synthase isoforms

Stratégies de lutte vis-à-vis du chancre coloré du platane (Ceratocystis platani): Avis de l’AnsesRapport d’expertise collective

Citation suggérée : Anses. (2022). Stratégies de lutte vis-à-vis du chancre coloré du platane (Ceratocystis platani). (saisine 2020-SA-0073). Maisons-Alfort : Anses, 123 p.Ceratocystis platani, le champignon pathogène responsable du chancre coloré du platane, est un organisme nuisible réglementé, dont l’introduction et la dissémination sont interdites, conformément aux réglementations nationale et européenne en vigueur. Au niveau européen, depuis le 14 décembre 2019, l’agent du chancre coloré du platane est catégorisé parmi les organismes de quarantaine et la maladie fait donc l’objet d’une lutte obligatoire sur tout le territoire de l’Union. En France, le chancre coloré du platane fait l'objet d'une lutte obligatoire sur l'ensemble du territoire national, conformément aux dispositions prévues dans l'arrêté du 22 décembre 2015. Cet arrêté a vocation à rester en vigueur mais des ajustements sont nécessaires afin de tenir compte des retours d’expérience, en particulier en matière de spécificité des foyers (urbains ou non, en bordure de cours d’eau ou non) et de difficultés d’accessibilité du terrain pour la mise en œuvre des mesures de gestion de foyer.En France, la maladie touche actuellement les régions Provence-Alpes-Côte d’Azur (PACA), Occitanie, Auvergne-Rhône-Alpes, Corse, Nouvelle-Aquitaine, et plus récemment les régions Pays-de-la-Loire et Île-de-France. Dans certains foyers des régions Occitanie et PACA, où le champignon est établi depuis plusieurs décennies, son éradication semble dorénavant impossible et une stratégie en vue de l’enrayement de la maladie doit être identifiée et appliquée

Int J Obes (Lond)

BACKGROUND: In obesity, metabolic stress and inflammation in injured tissues could favour enhanced shedding of procoagulant microparticles (MPs). At sites of endothelium injury, the swift recruitment of procoagulant leukocyte-derived MPs enables the initiation of blood coagulation and thrombus growth. OBJECTIVES: In obese females, we sought to evaluate the impact of a very low-calorie diet (VLCD) on procoagulant MP levels, fibrinolytic status, inflammation and endothelium damage. METHODS: Circulating biomarkers of vascular damage, fibrinolytic status, platelet activation and inflammation were measured before, 30 and 90 days after starting a short-term VLCD. MPs were measured by flow cytometry and capture assays. Their procoagulant potential was quantified using functional prothrombinase assays and their cellular origin were determined using flow cytometry (endothelium, platelet, leukocyte, lymphocyte and erythrocyte-derived MP) or capture assays. RESULTS: A total of 24 obese females (39 +/- 10 years) with a mean body mass index of 35 +/- 4 kg m(-2) were prospectively enroled. Procoagulant leukocyte-derived MPs were associated with the waist circumference at baseline (r=0.534; P=0.010) and at 90 days follow-up (r=0.487; P=0.021). At 90 days, weight reduction (-9.8%) was associated with a lowering of blood pressure, improvement of metabolic parameters and a significant reduction of plasminogen activator inhibitor-1 (PAI-1) (-38%), procoagulant platelet-derived MPs (-43%), leukocyte-derived MPs (-28%) and leptin (-32%) levels. CONCLUSION: In obese females, a short-term VLCD results in an overall improvement of the haemostatic balance characterized by the reduction of PAI-levels, diminished release of platelet and leukocyte-derived MPs and a reduction in leptin levels, an adipocyte-derived cytokine