Robust control of a bimorph mirror for adaptive optics system

We apply robust control technics to an adaptive optics system including a dynamic model of the deformable mirror. The dynamic model of the mirror is a modification of the usual plate equation. We propose also a state-space approach to model the turbulent phase. A continuous time control of our model is suggested taking into account the frequential behavior of the turbulent phase. An H_\infty controller is designed in an infinite dimensional setting. Due to the multivariable nature of the control problem involved in adaptive optics systems, a significant improvement is obtained with respect to traditional single input single output methods

School life satisfaction and peer connectedness of intellectually gifted adolescents in France: Is there a labeling effect?

International audienceIntellectual giftedness is commonly associated with a high level of intellectual functioning, an identification process whereby individuals are labeled as gifted, and adjustments in schools such as grade skipping. During adolescence, all these factors are prone to reduce peer connectedness and school life satisfaction. The aim of the present study was to disentangle the effects of these factors in a sample of 492 sixth and 10th graders. We identified three subsamples based on different characteristics associated with giftedness: students previously identified as gifted (n = 66), students who scored in the top 10% on a general intelligence test (n = 49), and students who had skipped a grade (n = 57). Comparative analysis showed that none of these subsamples differed from their respective control groups on school life satisfaction. Students labeled as gifted reported a lower level of peer connectedness, and the latter's contribution to school life satisfaction was significantly stronger within this subsample. These results underscore the importance of social integration for adolescents identified as intellectually gifted and exclude grade skipping as a risk factor. Moreover, high intellectual level does not seem to impact either school life satisfaction or peer connectedness

Analysis of geostationary satellite derived cloud parameters associated with high ice water content environments

International audienceWe present an evaluation of the ability of passive broadband geostationary satellite measurements to detect high ice water content (IWC > 1 g m −3) as part of the European High Altitude Ice Crystals (HAIC) project for detection of upper-atmospheric high IWC, which can be a hazard for aviation. We developed a high IWC mask based on measurements of cloud properties using the Cloud Physical Properties (CPP) algorithm applied to the geostationary Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI). Evaluation of the high IWC mask with satellite measurements of active remote sensors of cloud properties (CLOUD-SAT/CALIPSO combined in the DARDAR (raDAR–liDAR) product) reveals that the high IWC mask is capable of detecting high IWC values > 1 g m−3 in the DARDAR profiles with a probability of detection of 60–80 %. The best CPP predic-tors of high IWC were the condensed water path, cloud optical thickness, cloud phase, and cloud top height. The evaluation of the high IWC mask against DARDAR provided indications that the MSG-CPP high IWC mask is more sensitive to cloud ice or cloud water in the upper part of the cloud, which is relevant for aviation purposes. Biases in the CPP results were also identified, in particular a solar zenith angle (SZA) dependence that reduces the performance of the high IWC mask for SZAs > 60 °. Verification statistics show that for the detection of high IWC a trade-off has to be made between better detection of high IWC scenes and more false detections, i.e., scenes identified by the high IWC mask that do not contain IWC > 1 g m−3. However, the large majority of these detections still contain IWC values between 0.1 and 1 g m−3. Comparison of the high IWC mask against results from the Rapidly Developing Thunderstorm (RDT) algorithm applied to the same geostationary SEVIRI data showed that there are similarities and differences with the high IWC mask: the RDT algorithm is very capable of detecting young/new con-vective cells and areas, whereas the high IWC mask appears to be better capable of detecting more mature and ageing convection as well as cirrus remnants. The lack of detailed understanding of what causes aviation hazards related to high IWC, as well as the lack of clearly defined user requirements, hampers further tuning of the high IWC mask. Future evaluation of the high IWC mask against field campaign data, as well as obtaining user feedback and user requirements from the aviation industry, should provide more information on the performance of the MSG-CPP high IWC mask and contribute to improving the practical use of the high IWC mask

Gestational exposure to bisphenol A induces region-specific changes in brain metabolomic fingerprints in sheep

International audienceFetal brain development depends on maternofetal thyroid function. In rodents and sheep, perinatal BPA exposure is associated with maternal and/or fetal thyroid disruption and alterations in central nervous system development as demonstrated by metabolic modulations in the encephala of mice. We hypothesized that a gestational exposure to a low dose of BPA affects maternofetal thyroid function and fetal brain development in a region-specific manner. Pregnant ewes, a relevant model for human thyroid and brain development, were exposed to BPA (5 µg/kg bw/d, sc). The thyroid status of ewes during gestation and term fetuses at delivery was monitored. Fetal brain development was assessed by metabolic fingerprints at birth in 10 areas followed by metabolic network-based analysis. BPA treatment was associated with a significant time-dependent decrease in maternal TT4 serum concentrations. For 8 fetal brain regions, statistical models allowed discriminating BPA-treated from control lambs. Metabolic network computational analysis revealed that prenatal exposure to BPA modulated several metabolic pathways, in particular excitatory and inhibitory amino-acid, cholinergic, energy and lipid homeostasis pathways. These pathways might contribute to BPA-related neurobehavioral and cognitive disorders. Discrimination was particularly clear for the dorsal hippocampus, the cerebellar vermis, the dorsal hypothalamus, the caudate nucleus and the lateral part of the frontal cortex. Compared with previous results in rodents, the use of a larger animal model allowed to examine specific brain areas, and generate evidence of the distinct region-specific effects of fetal BPA exposure on the brain metabolome. These modifications occur concomitantly to subtle maternal thyroid function alteration. The functional link between such moderate thyroid changes and fetal brain metabolomic fingerprints remains to be determined as well as the potential implication of other modes of action triggered by BPA such as estrogenic ones. Our results pave the ways for new scientific strategies aiming at linking environmental endocrine disruption and altered neurodevelopment

Overview of the HAIC “Space-borne Observation and Nowcasting of High Ice Water Content Regions” Sub-Project and Mid-Term Results

International audienceThe High Altitude Ice Crystals (HAIC) Sub-Project 3 (SP3) focuses on the detection of cloud regions with high ice water content (IWC) from current available remote sensing observations of space-based geostationary and low-orbit missions. The SP3 activities are aimed at supporting operationally the two up-coming HAIC flight campaigns (the first one in May 2015 in Cayenne, French Guyana; the second one in January 2016 in Darwin, Australia) and ultimately provide near real-time cloud monitoring to Air Traffic Management. More in detail the SP3 activities focus on the detection of high IWC from space-borne geostationary Meteosat daytime imagery, explore the synergy of concurrent multi-spectral multiple-technique observations from the low-orbit A-Train mission to identify specific signatures in high IWC cloud regions, and finally develop a satellite-based nowcasting tool to track and monitor convective systems over the Tropical Atlantic. The paper presents the HAIC SP3 objectives and provides an objective status of the sub-project at mid term of the HAIC project

Corps et machines à l'âge industriel

L'industrialisation qui s'amorce à la fin du XVIIIe siècle apporte au monde occidental une multitude d'objets mécaniques dotés d'une puissance inédite. En décuplant les capacités du corps, les machines s'y substituent. Elles étendent son aire d'influence, déplacent les frontières corporelles ou donnent des images inédites d'un intérieur du corps, mais elles provoquent aussi de multiples altérations physiques. Au-delà des appréciations morales dont elles ont constamment été l'objet – alternativement perçues comme libératrices et aliénantes – cet ouvrage se propose de réfléchir aux rapports qu'elles nouent avec les corps, aux apprentissages dont elles font l'objet et à toute une expérience corporelle des machines, faites d'ajustements et adaptations réciproques. Ces vingt-trois études proposent autant d'analyses historiques spécifiques, destinées à cerner un territoire vaste et peu connu. En abordant les machines industrielles dont la chaîne de montage offre certainement un aboutissement, les machines de santé, les machines de mort ou le traitement mécanique des cadavres, les machines de loisirs et de transport, ou enfin les machines productrices d'images, ce livre propose d'inclure les machines dans l'histoire d'une anthropologie du corps contemporain

Compte-rendu exact et littéral des debats qui ont eu lieu devant la Cour d'Assises de Montbrison à l'occasion du procès dirigé contre MM. de Saint-Priest (Duc D'Almazan), de Kergorlay père, de Ménars, de Kergorlay fils, de Bourmont fils, Sala, de Lachau, de Bermond, de Candolle, Laget de Podio, Ésig, Ganail, Mlle Lebeschu et divers accusés absens.

"Rédigé sur des notes sténographiques mises en ordre par deux rédacteurs de la Gazette du midi."t. 1. Débats. -- t. 2-3. Défense.Mode of access: Internet