Micro-factory for submerged assembly : Interests and Architectures.

International audienceThe development of new hybrid microsystems needs new technologies which are able to perform assembly of small micro-objects. Now, the current micromanipulation technologies are still unreliable for micro-objects which typical size is down to hundred micrometers. Consequently, the study and the development of innovative artificial micro-object manipulation strategies in these dimensions are particularly relevant. As presented in the literature, micromanipulations are perturbed by the adhesion and surface forces which depend on surrounding mediums. We propose to perform micro-assembly tasks in liquid medium, because adhesion and surface forces applied on submerged microobjects are less important than in air. An overview of the microforces in air and in liquid is presented in this paper. This paper focuses on the architecture of a submerged assembly cell including the definition of stocks, conveyance systems and workstations. Defining the architecture of the submerged assembly cell is indeed a keypoint of the cell design. The stocks and workstations could be for example place in a large unique liquid medium or in a collection of droplets. Transfers of micro-objects in the submerged assembly cell may be obtained by: (i) moving the micro-objects in an unique liquid medium; (ii) moving the micro-objects through the air from one to another liquid medium; (iii) transfert of micro-objects by movement of the liquid bowl. The analysis of the combination of different transfer types allows the construction of the typical architectures of assembly cell for submerged medium

Regulation of the Fruit-Specific PEP Carboxylase SlPPC2 Promoter at Early Stages of Tomato Fruit Development

The SlPPC2 phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) gene from tomato (Solanum lycopersicum) is differentially and specifically expressed in expanding tissues of developing tomato fruit. We recently showed that a 1966 bp DNA fragment located upstream of the ATG codon of the SlPPC2 gene (GenBank AJ313434) confers appropriate fruit-specificity in transgenic tomato. In this study, we further investigated the regulation of the SlPPC2 promoter gene by analysing the SlPPC2 cis-regulating region fused to either the firefly luciferase (LUC) or the β-glucuronidase (GUS) reporter gene, using stable genetic transformation and biolistic transient expression assays in the fruit. Biolistic analyses of 5′ SlPPC2 promoter deletions fused to LUC in fruits at the 8th day after anthesis revealed that positive regulatory regions are mostly located in the distal region of the promoter. In addition, a 5′ UTR leader intron present in the 1966 bp fragment contributes to the proper temporal regulation of LUC activity during fruit development. Interestingly, the SlPPC2 promoter responds to hormones (ethylene) and metabolites (sugars) regulating fruit growth and metabolism. When tested by transient expression assays, the chimeric promoter:LUC fusion constructs allowed gene expression in both fruit and leaf, suggesting that integration into the chromatin is required for fruit-specificity. These results clearly demonstrate that SlPPC2 gene is under tight transcriptional regulation in the developing fruit and that its promoter can be employed to drive transgene expression specifically during the cell expansion stage of tomato fruit. Taken together, the SlPPC2 promoter offers great potential as a candidate for driving transgene expression specifically in developing tomato fruit from various tomato cultivars

Evaluations économiques de la réduction du risque d'inondation

International audienceVarious techniques for economic valuation of the "reduction of flood risk" non-market good are reviewed. The potentiality of the contingent valuation method is specifically discussed, on the basis of two surveys conducted in France. The results highlight an acceptability of flood risk beyond a certain protection level.Les différentes techniques possibles d'évaluation économique du bien non marchand "réduction du risque d'inondation " sont passées en revue. La potentialité de l'évaluation contingente est plus particulièrement discutée, au vu de deux enquêtes réalisées sur le territoire français. Les résultats mettent en évidence une acceptabilité du risque d'inondation à partir d'un certain niveau de protection

Gestion préventive des inondations : quels outils économiques pour l'aide à la décision ?

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Participation du public à la gestion préventive des inondations : utilisation d'une échelle de crue pour l'estimation des consentements à payer

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