Etude de l'effet du lindane (insecticide organochloré) sur le système immunitaire de la truite-arc-en-ciel

National audienc

Stereo-Matching of LineSegments based on a 3-dimensional heuristic with potential for Parallel Implementation

This work provides a segment-based alternative to the edge-based stereo algorithm already existing in the TINA system. Our starting point is the algorithm of Ayache & Faverjon (1985). It attempts to recover groups of linematches having low local disparity variations. In our implementation of Ayache & Faverjon's algorithm matches were built quickly, but glaring mistakes occurred and the general behaviour was difficult to control. Therefore the constraints on the continuity of the world implicitly used in the original approach were reformulated to achieve more robust matching, more particularly by requiring mutual support between reconstructed 3-D segments. A new algorithm has been designed that is suitable for parallel implementation, where 3-D matches and their neighbourhood relationships are explicitly computed, cliques found (objects) and uniqueness enforced. This paper describes a line based approach to binocular stereo that augments the capabilities of the TINA system (Porrill et al 1987, Pollard et al 1987). The already existing stereo matching is edge-based utilising the PMF algorithm (Pollard 1985) and its descendents. Whilst an edge based approach is more general, image structures that are amenable to description by linear approximations can be efficiently and robustly matched by an alternative strategy. Hence a combined approach is adopted allowing either, redundant cross primitive consistency to give increased robustness, or segment matching to seed matching at the lower level to improve efficiency. The starting point for this work is the segment matching algorithm due to Ayache and Faverjon (1985) which employs a hypothesis, propagation and test strategy to identify corresponding segments. Only a small number of well selected segments act as a basis for match hypotheses, the remainder being found as a result of the propagation stage. Their algorithm sets up a few likely correct matches and propagates them. Along the propagation, a weak disparity gradient constraint is enforced through an imposed limit upon the disparity difference between neighbouring matched segments

Effets aigus d'une irradition corps entier sur la sécrétion pancréatique exocrine chez le porc

International audienceReports on radiation damage to the pancreas deal essentially with long-term morphological changes with few data on pancreatic exocrine function. The aim of this work was to study the acute effects of whole body irradiation on volume and enzyme activities in the pancreatic juice. A whole body gamma irradiation (6 Gy) was investigated in pigs with continuous sampling of pancreatic juice before and after exposure via an indwelling catheter in the pancreatic duct. For each sample collected, total protein concentration and enzyme activities of trypsin, chymotrypsin, elastase, lipase and amylase were determined. Pancreatic juice volume was monitored during all periods of collection. The volume of pancreatic juice secreted daily decreased one day after irradiation and remained lower than the control values over the experimental period. Total proteins secreted in the pancreatic juice and total activities of pancreatic enzymes were reduced similarly. On the other hand, only specific activities of elastase and lipase were affected by irradiation. Whole body gamma irradiation resulted in a rapid and marked decrease of exocrine pancreatic secretion, in terms of volume as well as secreted enzymes. This may contribute in part to the intestinal manifestations of the acute and/or late radiation syndrome. © 2004 EDP Sciences

DESALINATION PERFORMANCE OF PV-POWERED STAND-ALONE OSMOSUN® UNIT UNDER INTERMITTENT OPERATING CONDITIONS

International audienc

Response to domestication and selection for growth in the European sea bass (<i>Dicentrarchus labrax</i>) in separate and mixed tanks

Selective breeding of European sea bass (Dicentrarchus labrax) receives a growing interest, as the estimated heritability of growth is medium to high. In this study, we compared the offspring of four groups of sea bass sires, mated with the same wild dams: wild (W), first generation of domestication (D), first generation of mass selection for length (M), first generation of PROSPER-like selection for length (P). The comparison was done both in replicated tanks (separate rearing) and in mixed tanks (mixed rearing) where sire origins were recovered by genotyping of eight microsatellite markers. Weight, length and growth rate were measured from day 238 post-fertilization (69 g mean weight) to day 611 post-fertilization (390 g mean weight). Both in mixed and separate tanks, both selected groups (P, M) were larger than unselected groups (W, D). No difference was seen at any time between W and D, nor between M and P. The selection response estimate on weight was larger in mixed tanks when compared to separate tanks (+ 42% in mixed tanks, + 23% in separate tanks at day 611), yielding realized heritability estimates of 0.60 and 0.34, respectively, and confirming the excellent potential of the species for growth improvement through selective breeding. Both selection response and the amplification effect between mixed and separate tanks decreased as rearing density increased. Our hypothesis is that selection response is magnified by competition in mixed tanks, while sub-optimal rearing conditions lower the observed selection response, more in separate tanks (where selected thus larger fish are at a higher density than unselected ones) than in mixed tanks (where all fish experience the same density effects)

Exploring the bottlenecks of anionic redox in Li-rich layered sulfides

Anionic redox chemistry has emerged as a new paradigm to design higher-energy lithium ion-battery cathode materials such as Li-rich layered oxides. However, they suffer from voltage fade, large hysteresis and sluggish kinetics, which originate intriguingly from the anionic redox activity itself. To fundamentally understand these issues, we decided to act on the ligand by designing new Li-rich layered sulfides Li1.33 – 2y/3Ti0.67 – y/3FeyS2, among which the y = 0.3 member shows sustained reversible capacities of ~245 mAh g−1 due to cumulated cationic (Fe2+/3+) and anionic (S2−/Sn−, n &lt; 2) redox processes. Moreover, its negligible initial cycle irreversibility, mitigated voltage fade upon long cycling, low voltage hysteresis and fast kinetics compare positively with its Li-rich oxide analogues. Moving from the oxygen ligand to the sulfur ligand thus partially alleviates the practical bottlenecks affecting anionic redox, although it penalizes the redox potential and energy density. Overall, these sulfides provide chemical clues to improve the holistic performance of anionic redox electrodes, which may guide us to ultimately exploit the energy benefits of oxygen redox