L’album au cycle 2 en classe bilingue : inducteur d’un projet de lectures ?

Professorat des écolesCe mémoire a pour base de réflexion l’apprentissage de la lecture dans une classe de cycle 2 bilingue. Il a été mené à partir d’un album de littérature de jeunesse allemande, Von Kopf bis Fuß de Eric Carle, intégré dans un projet de lectures qui recouvre différentes disciplines telles que la découverte du monde, la maîtrise du langage et de la langue, l’éducation artistique ou encore l’éducation physique et sportive. La question centrale qu’a présidé au choix de notre sujet de réflexion a été de savoir si un album peut être un support privilégié pour un projet de lectures, c’est à dire si l’on peut y greffer un ensemble de textes de natures diverses liés aux thèmes abordés dans l’album, et ainsi donner la possibilité à l’enfant de se familiariser avec un panel d’écrits différents

A single run LC-MS/MS method for phospholipidomics

International audienc

Synthetic toxic Aβ1–42 oligomers can assemble in different morphologies

International audienceBackground Alzheimer's disease is the most common neurodegenerative disease associated with aggregation of Aβ peptides. Aβ toxicity is mostly related to the capacity of intermediate oligomers to disrupt membrane integrity. We previously expressed Aβ1–42 in a eukaryotic cellular system and selected synthetic variants on their sole toxicity. The most toxic mutant G37C forms stable oligomers. Methods Different biophysical methods (Fluorescence spectroscopy, cross-linking, mass spectrometry (MS), Small Angle X-ray Scattering (SAXS), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), calcein leakage) were used. Results The oligomers are mostly populated by a 14 mers resulting from the packing of homodimers. These homodimers come from the formation of a disulfide bridge between two monomers. This link stabilizes the multimers and prevents the assembly into amyloid fibrils. These oligomers affect the membrane integrity. The reduction of disulfide bonds leads to a rearrangement and redirects assembly of Aβ amyloid fibrils. Conclusion The toxic synthetic AβG37C mutant can assemble into an amyloid of unusual morphology through the formation of anti-parallel β-sheets. This pathway involves the formation of oligomers resulting from the arrangement of Aβ dimers linked by covalent di-sulfide link, being these oligomers harmful for the membranes. General significance The capacity to produce large amount of stable oligomers without additional detergents or extrinsic cross-linkers allow further structural and biophysical studies to understand their capacity to assemble and disrupt the membranes, a key event in Alzheimer's disease

YPR139c/LOA1 encodes a novel lysophosphatidic acid acyltransferase associated with lipid droplets and involved in TAG homeostasis

LOA1, a yeast member of the glycerolipid acyltransferase family, encodes a novel lysophosphatidic acid acyltransferase associated with lipid droplets (LDs) and involved in triacylglycerol (TAG) accumulation. Loa1p, recruited during LD formation, preferentially directs oleic acid–containing phosphatidic acid species into the TAG biosynthetic pathway