Positionnement des sociologues dans la démarche de modélisation Domino

Au Sénégal et à La Réunion, gestion décentralisée des ressources naturelles et multiplicité des usages de l’espace amènent les gestionnaires du territoire à penser les complémentarités et compétitions entre secteurs d’activité et niveaux d’organisation. Des outils de représentation des interactions entre sociétés et écosystèmes et de leurs dynamiques existent mais peu sont construits avec les acteurs.Domino s’appuie sur la modélisation d’accompagnement. Dès ses premières étapes, cette démarche participative implique des chercheurs de disciplines différentes et des acteurs producteurs d’informations et potentiels utilisateurs. Le projet souhaite renforcer les capacités des acteurs pour mieux appréhender les enjeux de leur développement. Le sociologue y contribue en élaborant une grille de lecture de la réalité sociale qu’il s’agit ensuite de modéliser. Attentif au projet social originel il questionne l’adéquation entre la modélisation d’accompagnement et ses usages sociaux. Les théories sociologiques sont ici confrontées aux réalités du terrain. Ce pragmatisme revisite la posture sociologique.In Senegal and the Reunion Island, decentralized management of natural resources and multiplicity of land uses bring local development managers round to thinking about synergies and competition of branches and levels of organisation. There exist tools helpful to represent interactions among ecological and social systems and their dynamics. But rare of them are built with stakeholders.Domino is based on a Companion Modelling approach. From the start, this "participatory modelling approach" involves researchers of several disciplines and local stakeholders—producers of data and potential users. The project aims at reinforcing stakeholders' empowerment to tackle the stakes of their sustainable development. Sociologists involved build an analysis grid of social reality that can be used in the modelling process. Careful to the original social goal of the project, they question the appropriateness of Companion Modelling and its social uses, confronting sociological theories with field reality. This pragmatism reexamines the sociological posture

Anti-inflammatory effects of Lactobacillus casei BL23 producing or not a manganese-dependant catalase on DSS-induced colitis in mice

Background :Human immune cells generate large amounts of reactive oxygen species (ROS) throughout the respiratory burst that occurs during inflammation. In inflammatory bowel diseases, a sustained and abnormal activation of the immune system results in oxidative stress in the digestive tract and in a loss of intestinal homeostasis. We previously showed that the heterologous production of the Lactobacillus plantarum ATCC14431 manganese-dependant catalase (MnKat) in Lb. casei BL23 successfully enhances its survival when exposed to oxidative stress. In this study, we evaluated the preventive effects of this antioxidative Lb. casei strain in a murine model of dextran sodium sulfate (DSS)-induced moderate colitis.[br/] Results : Either Lb. casei BL23 MnKat- or MnKat+ was administered daily to mice treated with DSS for 10 days. In contrast to control mice treated with PBS for which DSS induced bleeding diarrhea and mucosal lesions, mice treated with both Lb. casei strains presented a significant (p < 0.05) reduction of caecal and colonic inflammatory scores.[br/] Conclusion : No contribution of MnKat to the protective effect from epithelial damage has been observed in the tested conditions. In contrast, these results confirm the high interest of Lb. casei as an anti-inflammatory probiotic strain

Heat transfer in a swirling fluidized bed with Geldart type-D particles

A relatively new variant in fluidized bed technology, designated as the swirling fluidized bed (SFB), was investigated for its heat transfer characteristics when operating with Geldart type D particles. Unlike conventional fluidized beds, the SFB imparts secondary swirling motion to the bed to enhance lateral mixing. Despite its excellent hydrodynamics, its heat transfer characteristics have not been reported in the published literature. Hence, two different sizes of spherical PVC particles (2.61mm and 3.65mm) with the presence of a center body in the bed have been studied at different velocities of the fluidizing gas. The wall-to-bed heat transfer coefficients were measured by affixing a thin constant foil heater on the bed wall. Thermocouples located at different heights on the foil show a decrease in the wall heat transfer coefficient with bed height. It was seen that only a discrete particle model which accounts for the conduction between the particle and the heat transfer surface and the gas-convective augmentation can adequately represent the mechanism of heat transfer in the swirling fluidized bed