Transient damage spreading and anomalous scaling in mortar crack surfaces

The scaling properties of a post-mortem mortar crack surface are investigated. The root mean square of the height fluctuations is found to obey anomalous scaling properties, but with three exponents, two of them characterizing the local roughness (zeta~=0.79 and zetae~=0.41) and the third one driving the global roughness (zetag~=1.60). The critical exponent zeta~=0.79 is conjectured to reflect damage screening occurring for length scales smaller than the process zone size, while the exponent zetae~=0.41 characterizes roughness at larger length scales, i.e., at length scales where the material can be considered as linear elastic. Finally, we argue that the global roughness exponent could be material dependent contrary to both local roughness exponents (zeta~=0.8 and zetae~=0.4) which can be considered as universal

Engagement associatif : ces retraités qui veulent être utiles aux autres...

National audienceCette communication présentée au deuxième congrès de l’Association Française de Sociologie (Bordeaux, 5-8 septembre 2006) fait un panorama de la participation associative des retraités aux débuts des années 2000 (en France), puis cherche à identifier ceux qui, par leur participation associative, ont la volonté d'agir sur leur environnement, proche ou lointain. Ne renonçant pas à certaines formes de militantisme, ils conçoivent leur action de façon altruiste au service de causes qui leur paraissent justes ; ils participent à des actions de solidarité qui dépassent la solidarité familiale intergénérationnelle. Dans cet article, nous qualifions ces retraités d' « engagés solidaires » et cherchons à les comptabiliser

Les productions sonores de l’écouteur du récit : coopération ou subversion?

Tout récit oral est jalonné de signes sonores émanant de celui qui écoute. L’analyse de deux récits a permis de dégager une typologie de ces signes (mm, ah bon, syntagmes qualifiants, etc.) ainsi que les conditions de leur production, liées aux propriétés intonatives du discours du narrateur. L’examen des propriétés intonatives des interventions de l’écouteur et des réactions qu’elles suscitent chez le narrateur a également permis de préciser le statut énonciatif de l’écouteur. Si ses productions sonores sont en intonation haute et montante (il marque qu’il abdique son identité d’énonciateur pour prêter sa voix au narrateur), elles sont immédiatement intégrées au discours du narrateur, alors que si elles sont en intonation basse et peu modulée (il s’approprie alors la position d’énonciateur), elles produisent automatiquement une rupture dans la continuité narrative.Any oral narrative also includes interventions from the hearer. Using a corpus of two French oral narratives, we make a typology of these interventions (mm, ah bon, qualifying phrases, etc.) and bring out the conditions in which they are used, according to their intonative properties. The analysis of the intonative properties of both of the hearer's interventions and of the narrator's reactions they bring about also lead us to make a distinction between two enunciative (interpersonal) attitudes: when his/her productions are high, with a rise, the hearer cooperates in the narrative, whereas when his/her productions are low and slightly modulated, the hearer takes the role of the speaker, which invariably introduces a breaking-point in the conversation

Connexins participate in the initiation and progression of atherosclerosis

Connexins are members of a large family of transmembrane proteins that form hemichannels or gap junctions. These channels allow the exchange of ions and small metabolites between the cytosol and extracellular space or between neighboring cells. Connexins are important in vascular physiology; they support radial and longitudinal cell-to-cell communication in the vascular wall. Four connexins are expressed in the vascular wall: Cx37, Cx40, Cx43, and Cx45. Their expression is not uniform in all blood vessels and varies with vascular territory and species. Significant changes in the expression pattern of vascular connexins have been described during the development of atherosclerosis, a progressive inflammatory disease. In this review, we provide an overview of (1) the tools used to study the involvement of connexins in atherosclerosis, (2) the participation of connexins in atherogenesis, (3) the increasing interest of a polymorphism in the human connexin37 gene as marker of cardiovascular disease, and (4) the possible therapeutic implications of connexin

EMA space: a collaborative workspace as collaborative urban ecosystem generator?

International audienceFollowing the industrial background, the necessity of the innovation is found at the level of the urban systems. The innovations are not only researched at the level of the results of the urban projects but also in the processes which see them born and develop. In addition, both the societal evolutions, described by the social and human sciences, and the results of multidisciplinary researches wonder about the involvement of the citizens / users in the process of output of the city. The emergence, for few years, of the Living Labs probably gives new opportunities to lead a reflection on the involvement of the citizens in the urban projects. From then on, it consists in mixing the questionings held by the user-driven open innovation and the stakes of "democratization" of the urban projects. It is in particular what suggests the Lorraine (NIT) Smart Cities Living Lab

Anisotropic self-affine properties of experimental fracture surfaces

The scaling properties of post-mortem fracture surfaces of brittle (silica glass), ductile (aluminum alloy) and quasi-brittle (mortar and wood) materials have been investigated. These surfaces, studied far from the initiation, were shown to be self-affine. However, the Hurst exponent measured along the crack direction is found to be different from the one measured along the propagation direction. More generally, a complete description of the scaling properties of these surfaces call for the use of the 2D height-height correlation function that involves three exponents zeta = 0.75, beta = 0.6 and z = 1.25 independent of the material considered as well as of the crack growth velocity. These exponents are shown to correspond to the roughness, growth and dynamic exponents respectively, as introduced in interface growth models. They are conjectured to be universal.Comment: 12 page

L'impératif en français et en anglais contemporains

As a deontic mode of enunciation, the imperative excludes any operation which implies a certain degree of agreement between speaker and addressee - presupposition, referential construction, etc. In order to make up for this fundamental disjunction, the speaker resorts to a range of compensatory devices such as the use of person desinences, the ethical dative, the position of clitic pronouns or the function of the first person plural. Yet an imperative utterance is also related to the declarative context in which it occurs, and this sometimes causes co-locution to give way to co-enunciation - witness the problem of negative imperatives, or markers of discourse consistency such as voyons in French. This twofold theoretical approach is here presented as applying to the French language, and then put to the test of the English language

Promouvoir les territoires : un problème d'échelle

International audienceConducting research in management related to territorial development interests the professional community including policy makers and stakeholders of the territory. However, the multiplicity of stakeholders in this development highlights a difficulty related to the aporetic nature of the definition of the territory, in this case the appropriate level to implement actions of place management. This paper aims to understand how to consider this scaling problem in analyzing the consumption of territory. To do this, it focuses on the need to rely on a mesosocial scale suitable to overcome the pitfalls that lead to some strict micro-geographical account of individuals in space. This approach enables to move towards the portability of traditional marketing tools to territorial development and to provide modestly to building the field of territorial sciences.Mener une recherche en sciences de gestion afférente au développement territorial présente des intérêts pour la communauté professionnelle dont les décideurs publics et les divers acteurs du territoire. Cependant, la multiplicité des parties prenantes à ce développement met en exergue une difficulté liée au caractère aporétique de la définition du territoire, en l’espèce la nature de l’échelle appropriée pour mettre en oeuvre des actions de marketing territorial. Cette communication se propose de montrer comment se pose ce problème d’échelle en matière d’analyse de la consommation de territoire. Pour ce faire, elle met l’accent sur la nécessité de s’appuyer sur une échelle méso-sociale propre à dépasser les écueils vers lesquels conduit notamment une stricte considération micro-géographique des individus dans l’espace. Cet angle permet de tenter d’avancer vers une portabilité des outils traditionnels du marketing au développement territorial et d’apporter modestement une pierre à l’édification du champ des sciences du territoire