β1 integrins mediate the BMP2 dependent transcriptional control of osteoblast differentiation and osteogenesis

Osteoblast differentiation is a highly regulated process that requires coordinated information from both soluble factors and the extracellular matrix. Among these extracellular stimuli, chemical and physical properties of the matrix are sensed through cell surface receptors such as integrins and transmitted into the nucleus to drive specific gene expression. Here, we showed that the conditional deletion of β1 integrins in the osteo-precursor population severely impacts bone formation and homeostasis both in vivo and in vitro. Mutant mice displayed a severe bone deficit characterized by bone fragility and reduced bone mass. We showed that β1 integrins are required for proper BMP2 dependent signaling at the pre-osteoblastic stage, by positively modulating Smad1/5-dependent transcriptional activity at the nuclear level. The lack of β1 integrins results in a transcription modulation that relies on a cooperative defect with other transcription factors rather than a plain blunted BMP2 response. Our results point to a nuclear modulation of Smad1/5 transcriptional activity by β1 integrins, allowing a tight control of osteoblast differentiation

Horizontal-FPN fault coverage improvement in production test of CMOS imagers

International audienceCurrent production testing of CMOS imager sensors is mainly based on capturing images and detecting failures by image processing with special algorithms. The fault coverage of this costly optical test is not sufficient given the quality requirements. Studies on devices produced at large volume have shown that Horizontal Fixed Pattern Noise (HFPN) is one of the common image failures encountered on products that present fault coverage problems, and this is the main cause of customer returns for many products. A detailed analysis of failed devices has demonstrated that HFPN failures arise from changes of electronic circuit topology in pixel addressing decoders or the metal lines required for pixel powering and control. These changes are usually due to the presence of spot defects, causing some pixels in a row to operate incorrectly, leading to an HFPN failure. Moreover, defects resulting in partially degraded metal lines may not induce image failure in limited industrial test conditions, passing the optical tests. Later, these defects may produce an image failure in the field, either because the capture conditions would be more stringent, or because the defects would evolve into catastrophic faults due to electromigration. In this paper, we have first enhanced the HFPN detection algorithm in order to improve the fault coverage of the optical test. Next, a built-in self-test structure is presented for the on-chip detection of catastrophic and non-catastrophic defects in the pixel power and control lines

Ancient canals in the valley of Bourgoin-La Verpillière (France, Isère): morphological and geoarchaeological studies of irrigation systems from the Iron Age to the Early Middle Ages (8th century bc–6th century ad)

International audienceAncient canals in the valley of Bourgoin-La Verpillière (France, Isère): morphological and geoarchaeological studies of irrigation systems from the Iron Age to the Early Middle Ages (8th century BC–6th century AD