125 research outputs found

    Référentiels et activité : un rapport complexe à améliorer

    Get PDF
    Que ferions-nous sans référentiels ? Aujourd’hui, en France et dans bien d’autres pays comparables, les référentiels sont devenus tellement omniprésents dans les sphères de la formation, de la certification et de la gestion qu’on peine à imaginer un monde et un fonctionnement social qui en seraient totalement dépourvus. Ces documents visent à formaliser « ce qui fait référence », c’est-à-dire des repères ou des normes, pour des situations de travail, des emplois ou des métiers donnés. Ils pro..

    Early Middle Paleozoic Intraplate Orogeny in the Ogcheon Belt (South Korea): A new insight on the Paleozoic buildup of east Asia

    No full text
    Laurent Jolivet est Professeur à l'Université d'Orléans depuis le 1er septembre 2009.International audienceThe polycyclic Ogcheon belt of South Korea represents the boundary between two Precambrian blocks. Investigation on the timing and kinematics of the block agglomeration is of considerable bearing on the understanding of the constitution of the Asian continent. We report here structural evidence showing that the earlier tectonic event dates back to early middle Paleozoic (the "Ogcheon tectonism" or "orogeny"). The ductile piling up of nappes of the Ogcheon belt corresponds to an intracontinental orogeny involving the opening and the subsequent closure of an aborted rift and not of a wide oceanic area. The nappes contain unequivocal evidence for ductile shearing with a northwest over southeast sense of movement. Field evidence includes the presence of S1 and S1-2 foliations bearing an extensive stretching lineation perpendicular to the belt, associated with a strongly noncoaxial deformation regime. The F1 isoclinal folds are commonly "A type" and sheath folds whose axes are parallel to the stretching lineation, whereas the southeast facing F2 recumbent folds have subhorizontal axes parallel to the belt. All lines of evidence (unconformity, superposed deformations, age of the metamorphism, etc...) imply that the D1-2 "Ogcheon tectonism" is pre-middle Carboniferous (Late Silurian-Early Devonian). The subsequent Indosinian (Middle Triassic) F3 upright synfolial folds that trend NNE-SSW and later structures clearly overprint the middle Paleozoic ductile thrusts and isoclinal folds. The early Paleozoic Ogcheon Supergroup is formed of a thick volcanosedimentary pile deposited above an early platform sequence in a rift basin. On the basis of the geochemical characteristics of the metavolcanics, it appears that oceanization did not occur and Ogcheon rift aborted soon after it was formed. We suggest that middle Paleozoic ductile nappe structures have been formed by the structural inversion of the rift extensional features. During the ductile stacking episode, the early formed foliation and isoclinal folds have been folded in a continuum during the same tectonic event. Middle Carboniferous terrigenous formations have been deposited unconformably upon folded and thrust older rocks. A tentative correlation with early Paleozoic Imjingang, Qinling and Cathaysian belts within the Asian continent reveals that Ogcheon rift was emplaced within the South China plate and that Imjingang belt should represent the limit between North and South China blocks in the Korean peninsula

    L’avenir appartient à ceux qui savent anticiper

    Get PDF
           Il est de bon ton d’afficher une ambition prospective dans le champ de la relation formation-emploi-travail. Depuis l’époque de la planification, l’Etat n’a cessé d’initier des travaux visant à prévoir, à anticiper ou à pronostiquer l’avenir quantitatif ou qualitatif des emplois pour tenter d’ajuster l’appareil de formation. Aujourd’hui, il perpétue pleinement cette tradition à travers notamment les travaux du Conseil d’analyse stratégique et de la Direction de l’animation de la reche..

    Les métiers manuels, incarnation suprême du « bon travail » ?

    Get PDF
    Qu’est-ce qu’un « bon travail » ou un emploi de qualité ? Si cette question d’ordre philosophique ne peut appeler une réponse simple et uniforme, elle n’est pourtant plus à éluder. Plus que jamais, il est aujourd’hui admis que le travail peut être à l’origine d’importants maux (maladies professionnelles, « risques psycho-sociaux »…), susceptibles eux-mêmes d’engendrer tout un ensemble de coûts plus ou moins cachés pour les organisations (non-qualité, absentéisme, démotivation…). De même, l’ex..

    Présentation de l’ouvrage Analyses de l’activité. Perspectives pour la conception et la transformation des situations de formation

    Get PDF
    Voilà un ouvrage collectif qui révèle et actualise les formidables potentialités que recèle l’analyse de l’activité pour la formation. En effet, l’ouvrage « traite de la conception et de la transformation des situations et dispositifs de formation à partir de l’analyse de l’activité » (C. Vidal-Gomel, p. 7). Celle-ci consiste « à identifier et à caractériser ce que font les acteurs, comment ils le font et pourquoi ils le font, en les considérant comme des ‘experts’ de leur travail et en prena..

    Genetic relations between the central and southern Philippine Trench and the Sangihe Trench

    No full text
    International audienceWe surveyed the junction between the central and southern Philippine Trench and the Sangihe Trench near 6øN using swath bathymetry, gravity, and magnetics. These data, along with seismicity, allow us to discuss the genetic relations between these trenches and the forces acting on converging plates. Our final model favors the northern extension of the Halmahera Arc up to 8øN, with three segments offset left-laterally along NW-SE transform faults. Accretion of the northern segment to Mindanao Island 4 to 5 m.y. ago resulted in the failure within the Philippine Sea Plate east of the arc. Initiation of the Philippine Trench between 7øN and 10øN agrees with the maximum recorded depth of the Philippine Trench floor (10,000 m below sea-level) and Philippine Sea slab (200 km). South of 6øN (trench junction), another segment of the arc is being subducted beneath the Sangihe margin, while south of 3øN, the southern segment of the Halmahera Arc is still active. The rapid southward shallowing of the trench floor along the southern Philippine Trench, the type of faulting affecting both sides of the trench, the lack of significant interplate seismicity, and the concentration of the seismicity beneath the Miangas-Talaud Ridge are interpreted as a slowing down of the subduction along this branch of the Philippine Trench compared with the rest of the subduction zone. The Sangihe deformation front has been recognized up to 7øN but seems active only south of 6øN

    Methamphetamine Preconditioning Alters Midbrain Transcriptional Responses to Methamphetamine-Induced Injury in the Rat Striatum

    Get PDF
    Methamphetamine (METH) is an illicit drug which is neurotoxic to the mammalian brain. Numerous studies have revealed significant decreases in dopamine and serotonin levels in the brains of animals exposed to moderate-to-large METH doses given within short intervals of time. In contrast, repeated injections of small nontoxic doses of the drug followed by a challenge with toxic METH doses afford significant protection against monoamine depletion. The present study was undertaken to test the possibility that repeated injections of the drug might be accompanied by transcriptional changes involved in rendering the nigrostriatal dopaminergic system refractory to METH toxicity. Our results confirm that METH preconditioning can provide significant protection against METH-induced striatal dopamine depletion. In addition, the presence and absence of METH preconditioning were associated with substantial differences in the identity of the genes whose expression was affected by a toxic METH challenge. Quantitative PCR confirmed METH-induced changes in genes of interest and identified additional genes that were differentially impacted by the toxic METH challenge in the presence of METH preconditioning. These genes include small heat shock 27 kD 27 protein 2 (HspB2), thyrotropin-releasing hormone (TRH), brain derived neurotrophic factor (BDNF), c-fos, and some encoding antioxidant proteins including CuZn superoxide dismutase (CuZnSOD), glutathione peroxidase (GPx)-1, and heme oxygenase-1 (Hmox-1). These observations are consistent, in part, with the transcriptional alterations reported in models of lethal ischemic injuries which are preceded by ischemic or pharmacological preconditioning. Our findings suggest that multiple molecular pathways might work in tandem to protect the nigrostriatal dopaminergic pathway against the deleterious effects of the toxic psychostimulant. Further analysis of the molecular and cellular pathways regulated by these genes should help to provide some insight into the neuroadaptive potentials of the brain when repeatedly exposed to drugs of abuse

    Methamphetamine-Induced Dopamine-Independent Alterations in Striatal Gene Expression in the 6-Hydroxydopamine Hemiparkinsonian Rats

    Get PDF
    Unilateral injections of 6-hydroxydopamine into the medial forebrain bundle are used extensively as a model of Parkinson's disease. The present experiments sought to identify genes that were affected in the dopamine (DA)–denervated striatum after 6-hydroxydopamine-induced destruction of the nigrostriatal dopaminergic pathway in the rat. We also examined whether a single injection of methamphetamine (METH) (2.5 mg/kg) known to cause changes in gene expression in the normally DA-innervated striatum could still influence striatal gene expression in the absence of DA. Unilateral injections of 6-hydroxydopamine into the medial forebrain bundle resulted in METH-induced rotational behaviors ipsilateral to the lesioned side and total striatal DA depletion on the lesioned side. This injection also caused decrease in striatal serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels. DA depletion was associated with increases in 5-HIAA/5-HT ratios that were potentiated by the METH injection. Microarray analyses revealed changes (± 1.7-fold, p<0.025) in the expression of 67 genes on the lesioned side in comparison to the intact side of the saline-treated hemiparkinsonian animals. These include follistatin, neuromedin U, and tachykinin 2 which were up-regulated. METH administration caused increases in the expression of c-fos, Egr1, and Nor-1 on the intact side. On the DA-depleted side, METH administration also increased the expression of 61 genes including Pdgf-d and Cox-2. There were METH-induced changes in 16 genes that were common in the DA-innervated and DA-depleted sides. These include c-fos and Nor-1 which show greater changes on the normal DA side. Thus, the present study documents, for the first time, that METH mediated DA-independent changes in the levels of transcripts of several genes in the DA-denervated striatum. Our results also implicate 5-HT as a potential player in these METH-induced alterations in gene expression because the METH injection also caused significant increases in 5-HIAA/5-HT ratios on the DA-depleted side
    • …
    corecore