Dynamiques et cadres organisationnels dans les activités sociales

Social activities take place in a complex collection of dynamics which are interplaying. Consequently, they are moved by a system of dynamics. Those system's dynamic properties are resulting of interplays between actors trying to influence their direction. While observing cooperatives networks, it appears that organisational pattern's in which activities are made, are determined by this system's dynamic properties.Partant de l'idée que les activités sociales étaient mues par un système de dynamiques, nous avons observé que les propriétés de ce système déterminaient la nature des cadres organisationnels dans lesquels une activité allait se dérouler. L'étude des activités de production des biens immatériels, nous a également permis de montrer que ces propriétés découlaient des interactions entre les acteurs qui cherchent à influer sur le cours de ces dynamiques

La dynamique des réseaux coopératifs : l’exemple des logiciels libres et du projet d’encyclopédie libre et ouverte Wikipédia.

Les pratiques organisationnelles et sociales non-marchandes et non-hiérarchiques liées aux nouvelles technologies de l'information et de la communication suscitent aujourd'hui de nombreuses réactions et controverses. Certains acteurs et chercheurs en contestent l'existence, d'autres affirment qu'il s'agit d'un phénomène minoritaire ou non durable, d'autres enfin, les cantonnent à la sphère virtuelle. S'inscrivant dans ces débats, ce travail analyse les différentes approches théoriques qui les sous-tendent, et les confronte à une observation empirique du réseau coopératif des logiciels libres et du projet d'encyclopédie libre et ouverte Wikipédia, en les replaçant dans le contexte idéologique propre à l'activité informatique. En développant un cadre conceptuel adéquat pour l'étude de ces entités sociales qui s'appuie sur l'interactionnisme symbolique et la sociologie critique d'Ivan Illich, cette réflexion dévoile la spécificité organisationnelle, économique et sociale de ces nouvelles pratiques, et expose ce qui a favorisé leur développement et leur croissance au cours de ces trois dernières décennies. L'accent est tout particulièrement mis sur l'intégration des facteurs culturels et sur la compréhension des mécanismes qui favorisent l'essor et l'expansion de ces nouvelles pratiques dans d'autres activités. Au final, cette réflexion rejoint un des questionnements fondamentaux de la société contemporaine, à savoir, celui posé par le développement de l'économie non-marchande et non-hiérarchique et par la déprofessionnalisation des activités immatérielles.Organizational and social non-market and non-hierarchical practices related to new information technologies and communication, caused many reactions and controversy. Some actors and thinkers their existence, others say it is a minority or unsustainable phenomenon, and others confined it exclusively to the virtual sphere. As part of these discussions, this thesis tries to make the synthese of the various theoretical approaches to these new practices and to confront them with a rigorous empirical observation of the cooperative network of free software and the free and open project of encyclopaedia Wikipedia. In developing a conceptual framework suitable to study the social entities, built on the symbolic interactionism and sociology critic Ivan Illich, this work show the specific organizational, economic and social form of these new practices, and understand what was able to promote their development and growth over the past three decades. We especially insist on cultural factors, rather than technical factors. Finally, the thesis attempts to reflect on what could eventually promote the development and expansion of these new practices. We are joining here a questioning of society deeper, and without answer : the challenges and uncertainties posed by the development of non-market economy and non-hierarchical.Réseaux coopératifs; Nouvelles technologies de l'information et de la communication;

Quand le Marché finance la résistance au Marché

Cet article tente de mieux cerner les causes du développement et du maintien du Réseau Coopératif des Logiciels Libres dans l'activité informatique. S'agissant du développement, nous mettons en avant le rôle décisif des facteurs culturels. En ce qui concerne le maintien, deux facteurs principaux sont étudiés : le transfert des ressources du Marché et des Appareils vers le Réseau Coopératif, et les stratégies politiques et juridiques des acteurs du Réseau Coopératif pour protéger leur cadre organisationnel.Logiciel libre, Marché, réseau coopératif, financement, appareil, open source

New evidence for the Hirnantian (Upper Ordovician) in Belgium? An integrated isotiopical, biostratigraphic and sedimentologic approach

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Sulfur and mercury MIF suggest volcanic contributions to Earth’s atmosphere at 2.7 Ga

This study received funding from a Natural Environment Research Council Standard Grant NE/M001156/1 (ALZ, EGN), and from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Grant 678812 to MWC).The Archean eon is associated with large-scale changes in Earth’s geosphere and biosphere, including the onset of plate tectonics and the expansion of oxygenic photosynthesis, although the full impacts of these changes on the atmosphere remain unclear. Here we present coupled records of mass independent fractionation of sulfur (S-MIF) and mercury (Hg-MIF) isotopes from well preserved sediments of the ∼2.7 billion year old (Ga) Manjeri Formation, Belingwe Greenstone Belt, Zimbabwe. These palaeoatmospheric proxies record different trends for S-MIF and odd number Hg-MIF versus even number Hg-MIF, providing novel constraints on atmospheric chemistry during this time. S-MIF and odd number Hg-MIF values are muted in comparison to values preserved in later Archean sediments, representing a combination of enhanced volcanic input and local mixing. Even number Hg-MIF is absent from these sediments, consistent with complete photo-oxidation of gaseous Hg0, which could have been driven by increased halogen emissions from arc volcanism. When considered within a global geodynamic context, these MIF data suggest an important role for subduction zone-related volcanism associated with early plate tectonics in modulating the ∼2.7 Ga atmosphere.Publisher PDFPeer reviewe

Archean (3.33 Ga) microbe-sediment systems were diverse and flourished in a hydrothermal context

International audienceInteracting, diverse microbe-sediment systems exist in natural environments today but have not yet been recognized in the oldest records of life on Earth (older than 3.3 Ga) because of lack of distinctive biomarker molecules and patchy preservation of microbial paleocommunities. In an in-situ outcrop-to microbial-scale study, we have differentiated probable phototrophic, chemolithotrophic, and chemo-organotrophic fossil microbial signatures in a nearshore vol-canogenic sedimentary setting in 3.33 Ga rocks of the Josefsdal Chert, Barberton greenstone belt, South Africa, while demonstrating the importance of contemporaneous hydrothermal activity. Hydrothermal fluids, as a nutrient source, strongly controlled the development and distribution of the microbial communities and, as a silicifying agent, contributed to their rapid fossilization. We thus show that intricate microbe-sediment systems are deep-rooted in time and that at least some early life may indeed have been thermophilic. INTRODUCTION Microbial communities in natural environments exist as multispecies assemblages that interact directly with one another and with their surroundings, and thus can be viewed as distinctive systems (Nealson, 1997). For example, a wide diversity of organotrophic and lithotro-phic (chemotrophic) microorganisms has been described in present-day, carbon-rich hydrother-mally influenced basaltic sediments (Callac et al., 2013), similar to those described from early Earth. However, lack of specific biomarker preservation in very ancient rocks (Summons, 1993) and haphazard preservation of microbial communities in general (Campbell et al., 2001; Orange et al., 2009) make tracing such systems in fossilized form to the oldest records of life on Earth (early Archean, older than 3.3 Ga) very challenging. Nevertheless, phototrophic microbial communities in early to mid-Archean (ca. 3.5–3.2 Ga) strata of South Africa and Australia have been well documented (). On the other hand, no previous investigations have recognized and addressed the syngenetic diversity of Archean microbial paleocommunities—both phototrophs and che-motrophs —within their sedimentary habitats at the microbial scale and using in-situ methods. Here we describe a macroscopic to microscopic investigation of the sedimentary and geochemical settings of widespread, fossilized phototrophic and chemotrophic microorganisms in early to mid-Archean (3.33 Ga) coastal sediments from the Josefsdal Chert, Barberton greenstone belt, South Africa. We also emphasize the importance of contemporaneous hydrothermal activity both as a source of energy for biomass production and as the means of preserving the biosignatures

A eukaryote assemblage intercalated with Marinoan glacial deposits in South Australia

Video of digital X-ray tomographs (µCT) in longitudinal plane through cylinder of siltstone, maximum diameter seen (left to right when viewing movie) is 5.4m