12 research outputs found
Contribution à l'étude des propriétés optiques structurales et superficielles des cristaux métalliques au moyen du microscope métallographique polarisant
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Proceedings of the 13th annual conference of INEBRIA
CITATION: Watson, R., et al. 2016. Proceedings of the 13th annual conference of INEBRIA. Addiction Science & Clinical Practice, 11:13, doi:10.1186/s13722-016-0062-9.The original publication is available at https://ascpjournal.biomedcentral.comENGLISH SUMMARY : Meeting abstracts.https://ascpjournal.biomedcentral.com/articles/10.1186/s13722-016-0062-9Publisher's versio
La minéralogie et la géotechnique
La géotechnique peut être définie comme l'ensemble des connaissances et des méthodes empruntées à la géologie, à la minéralogie et à l'art de l'ingénieur en vue de la construction.
Le rôle du minéralogiste dans ce domaine a été souvent mal individualisé et confondu avec celui du géologue, mais lorsque les ingénieurs, pour diminuer leurs prix de revient ont voulu réduire les coefficients de sécurité en utilisant toutes les possibilités de la matière, ils ont réalisé la nécessité des études minéralogiques donnant des indications précises sur la nature et la structure fine des matériaux.
L'exemple des bétons montre à quel point leur examen au niveau de la phase minéralogique du ciment ou de la roche et même les préoccupations géométriques à l'échelle de l'intervalle réticulaire peuvent être fructueuses et permettre d'atteindre une cohésion approchant celle de la matière naturelle. De même, l'étude de l'altération des roches met en évidence l'importance de la nature des minéraux constituants et de leur taux de fissuration, notions essentiellement minéralogiques. De nombreux autres exemples sont fournis d'interventions efficaces de la minéralogie en géotechnique ; aussi l'échelle d'observation et d'étude qui va de l'angström jusqu'aux dimensions macroscopiques des échantillons retient-elle de plus en plus l'attention de l'ingénieur de génie civil.Farran Jacques. La minéralogie et la géotechnique. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 77, 1-3, 1954. Soixante-quinzième anniversaire de la société française de minéralogie 1878-1853. pp. 132-143
Contribution à l'étude des propriétés optiques structurales et superficielles des cristaux métalliques au moyen du microscope métallographique polarisant
Propriétés optiques de divers cristaux métalliques
Capdecomme Laurent, Cambon Théophile, Farran Jacques. Propriétés optiques de divers cristaux métalliques. In: Bulletin de la Société française de Minéralogie, volume 71, 7-12, 1948. pp. 321-326
From genes to brain development to phenotypic behavior: "dorsal-stream vulnerability" in relation to spatial cognition, attention, and planning of actions in Williams syndrome (WS) and other developmental disorders.
Visual information is believed to be processed through two distinct, yet interacting cortical streams. The ventral stream performs the computations needed for recognition of objects and faces ("what" and "who"?) and the dorsal stream the computations for registering spatial relationships and for controlling visually guided actions ("where" and "how"?). We initially proposed a model of spatial deficits in Williams syndrome (WS) in which visual abilities subserved by the ventral stream, such as face recognition, are relatively well developed (although not necessarily in exactly the same way as in typical development), whereas dorsal-stream functions, such as visuospatial actions, are markedly impaired. Since these initial findings in WS, deficits of motion coherence sensitivity, a dorsal-stream function has been found in other genetic disorders such as Fragile X and autism, and as a consequence of perinatal events (in hemiplegia, perinatal brain anomalies following very premature birth), leading to the proposal of a general "dorsal-stream vulnerability" in many different conditions of abnormal human development. In addition, dorsal-stream systems provide information used in tasks of visuospatial memory and locomotor planning, and these systems are closely coupled to networks for attentional control. We and several other research groups have previously shown deficits of frontal and parietal lobe function in WS individuals for specific attention tasks [e.g., Atkinson, J., Braddick, O., Anker, S., Curran, W., and Andrew, R. (2003). Neurobiological models of visuospatial cognition in children with Williams Syndrome: Measures of dorsal-stream and frontal function. Developmental Neuropsychology, 23(1/2), 141-174.]. We have used the Test of Everyday Attention for Children (TEA-Ch) which aims to attempt to separate components of attention with distinct brain networks (selective attention, sustained attention, and attention control-executive function) testing a group of older children with WS, but this test battery is too demanding for many children and adults with WS. Consequently, we have devised a new set of tests of attention, the Early Childhood Attention Battery (ECAB). This uses similar principles to the TEA-Ch, but adapted for mental ages younger than 6 years. The ECAB shows a distinctive attention profile for WS individuals relative to their overall cognitive development, with relative strength in tasks of sustained attention and poorer performance on tasks of selective attention and executive control. These profiles, and the characteristic developmental courses, also show differences between children with Down's syndrome and WS. This chapter briefly reviews new research findings on WS in these areas, relating the development of brain systems in WS to evidence from neuroimaging in typically developing infants, children born very preterm, and normal adults. The hypothesis of "dorsal-stream(s) vulnerability" which will be discussed includes a number of interlinked brain networks, subserving not only global visual processing and formulation of visuomotor actions but interlinked networks of attention