Co-révision du "Modèle affectif et cognitif de l'enseignement explicite de la lecture" (MACEEL) avec six enseignants du primaire

Pourquoi certains élèves réussissent à lire, mais ne comprennent pas ce qu'ils lisent tandis que leurs pairs se servent de textes pour approfondir leurs connaissances? L'expérience en enseignement de la doctorante l'amène à constater l'effet débilitant de ce genre de difficultés en lecture qui affectent non seulement la performance scolaire, mais aussi l'estime de soi de l'élève (Damico, 2005; Leclerc et Moreau, 2010). Le Programme international de recherche en lecture scolaire (PIRLS, 2006) établit que 53 % des élèves de la 4e année se situent aux premier (18 %) et deuxième (35 %) niveaux de compétences minimales, ce qui implique qu'un trop grand nombre d'élèves ne possède pas une bonne compréhension de l’écrit. Chercheurs et enseignants s'interrogent donc sur les causes des difficultés et retiennent l'hypothèse qu'il faut travailler davantage la lecture dans la vie de l'élève (Bouffard, Mariné et Chouinard, 2004). Ils conviennent aussi que ce travail apparaît encore plus critique au moment où, les élèves parvenus aux 2e et 3e cycles du primaire, la lecture devient un des principaux outils d'apprentissage scolaire. Il est urgent de repenser comment outiller les enseignants afin de les aider à rencontrer les exigences des programmes scolaires, et ce, à plus forte raison quand le fait de vivre en milieu minoritaire réduit la performance en lecture des élèves (Gilbert, LeTouzé, Thériault et Landry, 2004). Pour favoriser la réussite en lecture, la chercheure développe un modèle novateur d'enseignement (2004) qui, en plus d'un travail sur le plan de la médiation des stratégies cognitives et métacognitives, ajoute un volet touchant les compétences affectives afin que l'acte de lire prenne tout son sens. Les questions de la présente recherche visent, d'une part, à déterminer quelles modifications doivent être apportées au modèle pour lui conférer une utilité optimale en situation d'enseignement en classe ordinaire, et d'autre part, à examiner quelles modifications ce travail de révision produit sur l'enseignement de la lecture des enseignants participants. La présente étude s'inscrit dans un paradigme de recherche-action (Kemmis et McTaggart, 1998). Cette recherche à caractère social est fondée sur la conviction qu'en réunissant la recherche et l'expertise des enseignants, on parvient à une compréhension plus efficace des enjeux qui risquent de compromettre le changement visé (Gilbert et Trudel, 2001; Savoie-Zajc, 2004). Pendant quatre mois et demi, six enseignants forment une communauté apprenante (Smith, 2000) qui travaillent en groupes de discussion à expérimenter le modèle et à proposer des pistes d'amélioration. L'analyse du verbatim découlant des rencontres individuelles et de groupe est facilitée en utilisant le logiciel d'analyses qualitatives ATLAS-ti. La recherche permet entre autres : 1) de mettre en exergue les moyens les plus efficaces d'enseigner la compréhension de lecture pour assurer une combinaison entre affectivité, cognition et métacognition; 2) d'examiner le rôle que joue l'ancrage affectif dans l'utilisation des stratégies cognitives et métacognitives; 3) d'établir de quelle manière le sens se co-construit dans la discussion et de quelle manière cette discussion, lorsque étalée dans le temps, donne à voir les changements opérés à ce sens; et 5) d'établir des liens clairs entre les trois pôles complémentaires de l'éducation, soit la formation, la recherche et l’action.\ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : modèle de lecture, affectivité, enseignement explicite, métacognitio

Impairment of gut microbial biotin metabolism and host biotin status in severe obesity: effect of biotin and prebiotic supplementation on improved metabolism

Objectives Gut microbiota is a key component in obesity and type 2 diabetes, yet mechanisms and metabolites central to this interaction remain unclear. We examined the human gut microbiome\u27s functional composition in healthy metabolic state and the most severe states of obesity and type 2 diabetes within the MetaCardis cohort. We focused on the role of B vitamins and B7/B8 biotin for regulation of host metabolic state, as these vitamins influence both microbial function and host metabolism and inflammation. Design We performed metagenomic analyses in 1545 subjects from the MetaCardis cohorts and different murine experiments, including germ-free and antibiotic treated animals, faecal microbiota transfer, bariatric surgery and supplementation with biotin and prebiotics in mice. Results Severe obesity is associated with an absolute deficiency in bacterial biotin producers and transporters, whose abundances correlate with host metabolic and inflammatory phenotypes. We found suboptimal circulating biotin levels in severe obesity and altered expression of biotin-associated genes in human adipose tissue. In mice, the absence or depletion of gut microbiota by antibiotics confirmed the microbial contribution to host biotin levels. Bariatric surgery, which improves metabolism and inflammation, associates with increased bacterial biotin producers and improved host systemic biotin in humans and mice. Finally, supplementing high-fat diet-fed mice with fructo-oligosaccharides and biotin improves not only the microbiome diversity, but also the potential of bacterial production of biotin and B vitamins, while limiting weight gain and glycaemic deterioration. Conclusion Strategies combining biotin and prebiotic supplementation could help prevent the deterioration of metabolic states in severe obesity

Selection of DNA aptamers against penicillin G using Capture-SELEX for the development of an impedimetric sensor

International audienceThis paper describes for the first time the selection of aptamers selective to penicillin. Aptamers were selected using a specific process called Capture-SELEX (Systematic Evolution of Ligands by Exponential Enrichment). This technique is based on the selection of DNA aptamers using penicillin G in solution while the ssDNA library is fixed on a support. One aptamer showing a good affinity to penicillin was finally selected and tested in electrochemical sensor configuration, using electrochemical impedance spectroscopy as detection technique. The developed aptasensor allowed the detection of penicillin in a wide concentration range, comprised between 0.4 and 1000µgL-1 Such performance was compatible with milk analysis, as the maximum residue limit tolerated in this matrix is 4µgL-1. The selectivity of the developed sensor was also studied, showing that the sensor was also able to bind other beta-lactam antibiotics, although with a weaker affinity. Finally the sensor was used for detection of penicillin G in milk. It was shown that a simple sample treatment with isopropanol followed by filtration was sufficient to eliminate matrix effects, allowing the determination of penicillin in milk at concentrations compatible with legislation requirements

Seismicity near Mayotte explained by interacting magma bodies: Insights from numerical modeling

International audienceMayotte island experienced a large volcanic eruption 50 km offshore in 2018-2021, creating the submarine volcano "Fani Maoré". The eruption was accompanied by intense seismicity at mantle depths (20-45 km), divided into a "proximal" and a "distal" cluster centered 10 and 30 km east from the island, respectively. Previous studies suggest that two separate magma reservoirs may lie at the top and bottom of the proximal cluster. Here, we assess whether two reservoirs are a mechanically viable explanation for the proximal cluster's truncated conical shape. We developed finite-element models of pressurized magma reservoirs in a 2D axisymmetric domain, modeling the reservoirs as compliant elastic ellipsoids embedded in an elastoplastic host rock. We find that, at these depths, extremely low friction is required to generate failure at realistically low reservoir pressures. This implies in turn that mechanical weakening must occur at these depths. The weakening could be induced by fractures or pore fluid overpressure in the volcanic system. We find that two superimposed reservoirs can generate a plastic domain between them, if they are spatially close enough. Several reservoir geometries (from spherical to sill-like) are plausible. A conical fracture domain is more likely to appear for reservoirs with opposite pressure loads (i.e. one inflating, one deflating). Given the geometrical match with the proximal seismicity cluster at Mayotte, we suggest that the shallower (Moho-depth) reservoir is inflating, creating a potential hazard for Mayotte island

The lower Loire river floodplain formation: a multi-scaled approach to characterize landforms, processes and drivers evolution on the long-term (last 10 milleniums) (Val d'Authion), France

International audienceIn the current context of global change, the knowledge of floodplain formation in response to past climate and societal changes is a solution for a better perception of the current and future dynamics. This research deals with floodplains formation, particularly with fluvial landforms, processes and drivers evolution on the long-term, during the Holocene. The case study is the Lower Loire River floodplain, a major hydrosystem of mid latitudes Western Europe, where current flood risks issues are significant and where the river embankment began during the Middle Ages [Research program: AGES (Ancient Geomorphological Evolutions)]. Fluvial landforms and sedimentary records studied are archived in this wide floodplain (section width 10Km, length 70Km). Hydrosedimentary flows come from a watershed (> 100 000Km2) extending partly on Hercynian massifs (Massif Central and Massif Armoricain) and a meso-cenozoic sedimentary basin (Bassin de Paris). Past fluvial dynamics, processes and temporalities of floodplain formation were reconstructed through an integrated approach [geomatics (LiDAR DEM), morphostratigraphy (core-drillings), sedimentology, geophysics (resistivity methods), geochronology and archaeology]. Within the Lower Loire River floodplain, Holocene fluvial landforms and alluvial deposits are nested in Weichselian formations and vertically stacked. During the last 10 millenniums, many Weichselian inheritances and the relatively low specific stream power of the river explain the low lateral mobility of the active channel. The Loire River built a significant natural levee and induced a vertical aggradation of the distal plain. Fluvial dynamics and sedimentary environments of the Lower Loire River evolved according to multi-millennium and multi-centennial scales. Responses of the river to external factors (climate, anthropogenic impacts, eustatism) and autocyclic evolution are discussed. Several episodes of the floodplain formation are characterized and are correlated with Holocene drivers evolution. Current fluvial dynamics inherit this floodplain formation on the long-term

The lower Loire river floodplain formation: a multi-scaled approach to characterize landforms, processes and drivers evolution on the long-term (last 10 milleniums) (Val d'Authion), France

International audienceIn the current context of global change, the knowledge of floodplain formation in response to past climate and societal changes is a solution for a better perception of the current and future dynamics. This research deals with floodplains formation, particularly with fluvial landforms, processes and drivers evolution on the long-term, during the Holocene. The case study is the Lower Loire River floodplain, a major hydrosystem of mid latitudes Western Europe, where current flood risks issues are significant and where the river embankment began during the Middle Ages [Research program: AGES (Ancient Geomorphological Evolutions)]. Fluvial landforms and sedimentary records studied are archived in this wide floodplain (section width 10Km, length 70Km). Hydrosedimentary flows come from a watershed (> 100 000Km2) extending partly on Hercynian massifs (Massif Central and Massif Armoricain) and a meso-cenozoic sedimentary basin (Bassin de Paris). Past fluvial dynamics, processes and temporalities of floodplain formation were reconstructed through an integrated approach [geomatics (LiDAR DEM), morphostratigraphy (core-drillings), sedimentology, geophysics (resistivity methods), geochronology and archaeology]. Within the Lower Loire River floodplain, Holocene fluvial landforms and alluvial deposits are nested in Weichselian formations and vertically stacked. During the last 10 millenniums, many Weichselian inheritances and the relatively low specific stream power of the river explain the low lateral mobility of the active channel. The Loire River built a significant natural levee and induced a vertical aggradation of the distal plain. Fluvial dynamics and sedimentary environments of the Lower Loire River evolved according to multi-millennium and multi-centennial scales. Responses of the river to external factors (climate, anthropogenic impacts, eustatism) and autocyclic evolution are discussed. Several episodes of the floodplain formation are characterized and are correlated with Holocene drivers evolution. Current fluvial dynamics inherit this floodplain formation on the long-term

Readjustments of a sinuous river during the last 6000 years in northwestern Europe (Cher River, France): From an active meandering river to a stable river course under human forcing

International audiencePalaeomeanders are characteristic features of meandering river floodplains. Some were abandoned several millennia ago and can be used as evidence for past fluvial patterns. Despite many observations of changes undergone by meandering rivers, little is known about long-term morphological adjustment of meanders. This paper reports on investigations conducted in two reaches located in the middle valley of the Cher River (northwestern Europe, France) to examine the readjustments of lowland meanders during the second half of the Holocene. The aim of our study was to provide new insights into the complex dynamics that control low-energy meandering rivers. LiDAR DEM spatial analyses coupled with geophysical surveys and observations of sediments enabled the identification and dating of thirteen palaeomeanders embedded in coarse sediments (sand and gravel) while the whole floodplain is covered by silty overbank deposits. Sedimentological, geochemical and pollen analyses combined with radiocarbon and OSL dating allowed us to reconstruct the chronology of the cutoff and the filling of palaeochannels. No palaeochannels older than ca 6000 yr cal. BP, and no palaeochannels younger than the eleventh-thirteenth centuries cal. AD were identified. This allowed us to distinguish two periods of meandering processes. (1) Our observations demonstrate the multi-millennia persistence of an active meandering pattern in a context of land use changes (ca 6000 yr cal. BP-eleventh-thirteenth centuries cal. AD). The preserved mobility of the river can be mainly interpreted as the result of the low cohesiveness of the bank material. Too few fine sediments were delivered during the proto-historical and historical periods to help stabilize the river course. (2) Following the eleventh-thirteenth centuries cal. AD, the fluvial system underwent a laterally stable phase. The many medieval and modern hydraulic engineering works reduced the specific stream power and prevented lateral erosion. The drastic decrease in the river's capacity to generate new meanders resulted in the disappearance of floodplain lakes and loss of habitat diversity

Prognosis of HER2-positive pregnancy-associated breast cancer: Analysis from the French CALG (Cancer Associé à La Grossesse) network

International audienceIntroduction: The prevalence of pregnancy-associated breast cancer is increasing. HER2-positive breast cancers typically have a poor prognosis. The objective of our study was to compare the prognosis of patients with HER2-positive breast cancer diagnosed during pregnancy (HER2-positive BCP) to young women diagnosed with HER2-positive breast cancer outside of pregnancy (HER2 non-BCP).Methods: Data of patients managed for invasive breast carcinoma between January 2005 and 2020 were retrospectively collected from the database of Tenon University Hospital (Paris, France), part of the "Cancer lié à la Grossesse" network.Results: Fifty-one patients with HER2-positive BCP were matched on age at diagnosis with 51 HER2-positive non-BCP patients. Locally advanced disease with axillary lymph node involvement were frequent. Tumors were frequently aggressive with high grade (p = 0.57) and high Ki67 (p = 0.15). Among the HER2-positive BCP patients, the mean term at diagnosis was 19.3 week of gestation (WG). Eighty-four percent of the patients continued their pregnancy with a mean term at delivery of 34.2WG. Chemotherapy modalities differed between the two groups: neoadjuvant chemotherapy was more frequent in the HER2-positive BCP group (p = 0.03) and adjuvant chemotherapy more frequent in the HER2 non-BCP group (p = 0.009). The recurrence rate was 10% (n = 5) and 18% (n = 9) in the HER2-positive BCP and HER2 non-BCP groups, respectively, p = 0.25. Breast cancer-free survival was poorer in the HER2-positive BCP group with earlier recurrence, p = 0.008. No difference in type of recurrence was found between the groups (p = 0.58).Conclusion: This matched case-control study implies that patients with HER2-positive BCP still have a poorer prognosis than non-pregnant HER-positive patients

Description phonético-acoustique de la parole dysarthrique: le projet DesPho-APaDy

Dysarthria; database; phonetics; variability of speechNational audienceUne première partie du projet est donc consacrée à la mise en place et à la structuration d'une base de données informatisée de parole pathologique. Actuellement, celle- ci est alimentée par les enregistrements de plus de mille patients dysarthriques collectés par C. Chevrie-Muller entre 1965 et 1997. A terme, la structure de cette base de données, permettant un accès sécurisé à différentes informations sur les locuteurs et les types de matériaux linguistiques, sera un outil extrêmement utile pour toute étude sur les dysfonctionnements de la parole et de la voix, et facilitera ainsi le contrôle de l'homogénéité/hétérogénéité clinique des locuteurs qui est central dans ce type d'étude