Bridging the Gap between the User's Digital and Physical Worlds with Compelling Real Life Social Applications

Nowadays, the majority of web sites and web-based applications encourage their users to engage in social interactions such as adding comments, expressing opinions or sharing content with their friends in social networking websites. Social activities involve basically: (i) users, (ii) user generated content -UGCthat users create and share and (iii) resources that are described with the created content. The logical structure of the underlying knowledge emerges as a set of links between the three aforementioned components. More concretely, a user generally annotates resources with different forms of user generated content, like social annotations, tags or links. As a consequence, huge amounts of shared social data are now available, which raises new challenges for information management and discovery. Each social interaction represents an opportunity to create valuable knowledge that can be further leveraged for added-value services (e.g. recommendation or prediction)

The La Bellière gold and antimony district (French Armorican Massif): a two-stage evolution model controlled by Variscan strike-slip tectonic

International audienceThe La Bellière gold district, in the Ligerian domain of the Armorican Massif is the third one of France in term of production. It shows gold-bearing quartz veins neighboring with a complex network of Sb veins, hosted in the Neoproterozoic metasedimentary basement of the Mauges Nappe. New structural data, mineralogical, textural and geochemical assays have been carried out to clarify the gold and Sb veins relationships. Our results favor of two-step hydrothermal event with an early deep-seated gold event followed by a late shallower Sb event. The gold-bearing quartz veins are hosted by N60°E to N90°E sinistral strike-slip faults. These veins exhibit a four-stage paragenesis: 1) early barren quartz filling, 2) arsenopyrite-pyrite with minor scheelite assemblage, 3) gold and base metal sulfides crystallized after a ductile/brittle deformation stage, and 4) pyrite-carbonate coeval with a late brittle stage. These results support a continuous evolution model from a deep emplacement level (12 to 9 km) to a shallow one (7 to < 5 km) with a brutal change in the P/T conditions that triggered the deposition of gold (stage 2) controlled by a seismic-valve mechanism. On the contrary, Sb veins correspond to open space vein types, hosted in a N20°W to N20°E conjugated strike-slip fault network arranged in a Riedel shear model, controlled by N130-140°E regional dextral strike-slip shear zone associated to the South Armorican Shear Zone system. A two-stage evolution is recognized, the first one consists of early pyrite-arsenopyrite with microcrystalline quartz, followed by a late stibnite stage formed after geodic quartz deposition. Quartz texture argues for a shallow emplacement (< 5 km) of veins controlled by a suction-pump mechanism. Chronologically, the gold vein opening complies with a NE-SW maximum shortening direction different from the late-Variscan stress field responsible for the dextral Armorican shear zone during late Carboniferous, and constrains an indirect dating. Thus, a Visean age is proposed for the formation of gold veins. The overall features of gold deposits are close to those of mesozonal orogenic gold deposits in Europe. Conversely, Sb-bearing veins are generated by a N-S shortening during the late Carboniferous. The Sb event, distinct in time from the earlier gold one, might correspond to a different expression of the so-called “epizonal” type in the orogenic gold model. It is proposed that the Late Carboniferous “Or 300” event is not the unique metallogenic period for gold deposition in the French Variscan domain. Our study highlights the role of the sinistral strike-slip shearing of possible Visean age, in the gold metallogenesis of the Ligerian domain

The genesis of gold in Sb-As and Sb-Au ore veins, new constraints from the study of the La Belli&#232;re and La Lucette districts (Armorican Massif, France)

International audienc

La colonisation de pucerons en cultures de melon - L'emploi des bandes fleuries comme outil de régulation

The impact of flower strips on the colonization of crops by the aphid Aphis gossypii and its natural enemies was studied from 2013 et 2015 within the framework of the AGATH project, funded by the Ministère de l’Agriculture, de l’Alimentation et de la Forêt (Casdar) and led by the Ctifl. A mix of flowers, tailored by the INRA (French National Institute for Agricultural Reasearch) to attract natural enemies of aphids in the proximity of melon crops without having a negative impact on the crops, was assessed in a network of plots throughout the three main melon production areas. The attractivity of this mix of flowers to natural enemies was characterized. The density of A. gossypii and of arthropod predator and/or parasitoid populations was compared in melon plots with these flower strips and in identical plots in terms of crop management but with bare soil.L’effet de bandes fleuries sur la colonisation des cultures par le puceron Aphis gossypii et ses ennemis naturels a été étudié dans le cadre du projet AGATH, soutenu par le ministère de l’Agriculture, de l’Alimentation et de la Forêt (Casdar) et porté par le Ctifl de 2013 à 2015. Un mélange fleuri conçu par l’Inra pour attirer les ennemis naturels de pucerons à proximité des parcelles de melon sans exercer en parallèle d’effet délétère sur les cultures a été évalué dans un réseau de parcelles réparties dans les trois principaux bassins de production de melons. L’attractivité de ce mélange fleuri vis-à-vis des principaux ennemis naturels de pucerons a été caractérisée. Les densités des populations d’A. gossypii et d’arthropodes prédateurs et/ou parasitoïdes de pucerons mesurées dans des parcelles de melon bordées par ce mélange fleuri et dans des parcelles identiques en termes d’itinéraire technique mais bordées par une surface de sol nu ont été comparées

A Multi-Purpose Ontology-Based Approach for Personalized Content Filtering and Retrieval

Abstract. Personalised multimedia access aims at enhancing the retrieval process by complementing explicit user requests with implicit user preferences. We propose and discuss the benefits of the introduction of ontologies for an enhanced representation of the relevant knowledge about the user, the context, and the domain of discourse, as a means to enable improvements in the retrieval process and the performance of adaptive capabilities. We develop our proposal by describing techniques in several areas that exemplify the exploitation of the richness and power of formal and explicit semantics descriptions, and the improvements therein. 1