28 research outputs found
Radio sur fibre pour un réseau local domestique millimétrique
National audienceLe projet FUI ORIGIN (Optical-Radio Infrastructure for Gigabit/s Indoor Networks) adresse le marché du Réseau Local Domestique pour lequel il propose une nouvelle infrastructure à très haut débit associant un câblage à fibre optique avec une diffusion radio 60GHz. Les premiers tests de cette infrastructure ont donné des résultats probants : un lien Radio sur Fibre en fréquence intermédiaire étendant la portée d'une transmission radio millimétrique est ici proposé et caractérisé complètement en termes d'EVM. Ce concept est validé par l'utilisation de produits commerciaux Wireless HD. Les études se poursuivent pour intégrer les systèmes optique-microondes en utilisant des composants bas coûts et innovants, comme les phototransistors SiGe/Si et des VCSEL analogiques
Liaison sans fils à 60 GHz et réseau domestique multi-gigabit/s basé sur une infrastructure radio sur fibre bas coût
National audienceLe projet FUI8 ORIGIN (Optical Radio Infrastructure for Gigabit/s Indoor Network) s'adresse au marché du Réseau Local Domestique (RLD) en proposant une infrastructure bas coût qui combine l'efficacité de la fibre optique pour la diffusion radio avec les avantages d'une transmission sans fils. Les premières réalisations et les tests réussis sont présentés dans ce papier
Retinoic Acid Signalling and the Control of Meiotic Entry in the Human Fetal Gonad
The development of mammalian fetal germ cells along oogenic or spermatogenic fate trajectories is dictated by signals from the surrounding gonadal environment. Germ cells in the fetal testis enter mitotic arrest, whilst those in the fetal ovary undergo sex-specific entry into meiosis, the initiation of which is thought to be mediated by selective exposure of fetal ovarian germ cells to mesonephros-derived retinoic acid (RA). Aspects of this model are hard to reconcile with the spatiotemporal pattern of germ cell differentiation in the human fetal ovary, however. We have therefore examined the expression of components of the RA synthesis, metabolism and signalling pathways, and their downstream effectors and inhibitors in germ cells around the time of the initiation of meiosis in the human fetal gonad. Expression of the three RA-synthesising enzymes, ALDH1A1, 2 and 3 in the fetal ovary and testis was equal to or greater than that in the mesonephros at 8–9 weeks gestation, indicating an intrinsic capacity within the gonad to synthesise RA. Using immunohistochemistry to detect RA receptors RARα, β and RXRα, we find germ cells to be the predominant target of RA signalling in the fetal human ovary, but also reveal widespread receptor nuclear localization indicative of signalling in the testis, suggesting that human fetal testicular germ cells are not efficiently shielded from RA by the action of the RA-metabolising enzyme CYP26B1. Consistent with this, expression of CYP26B1 was greater in the human fetal ovary than testis, although the sexually-dimorphic expression patterns of the germ cell-intrinsic regulators of meiotic initiation, STRA8 and NANOS2, appear conserved. Finally, we demonstrate that RA induces a two-fold increase in STRA8 expression in cultures of human fetal testis, but is not sufficient to cause widespread meiosis-associated gene expression. Together, these data indicate that while local production of RA within the fetal ovary may be important in regulating the onset of meiosis in the human fetal ovary, mechanisms other than CYP26B1-mediated metabolism of RA may exist to inhibit the entry of germ cells into meiosis in the human fetal testis
Sea urchin embryo as a model for analysis of the signaling pathways linking DNA damage checkpoint, DNA repair and apoptosis
Radio sur fibre pour un réseau local domestique millimétrique
National audienceLe projet FUI ORIGIN (Optical-Radio Infrastructure for Gigabit/s Indoor Networks) adresse le marché du Réseau Local Domestique pour lequel il propose une nouvelle infrastructure à très haut débit associant un câblage à fibre optique avec une diffusion radio 60GHz. Les premiers tests de cette infrastructure ont donné des résultats probants : un lien Radio sur Fibre en fréquence intermédiaire étendant la portée d'une transmission radio millimétrique est ici proposé et caractérisé complètement en termes d'EVM. Ce concept est validé par l'utilisation de produits commerciaux Wireless HD. Les études se poursuivent pour intégrer les systèmes optique-microondes en utilisant des composants bas coûts et innovants, comme les phototransistors SiGe/Si et des VCSEL analogiques
A Methodology for Determining the Mineral Content and Particle Size Distribution of Airborne Coal Mine Dust
Exploration and exploitation: Do actual behaviors match individuals’ perceptions?
Research on contextual ambidexterity assumes that an organization’s capacity to pursue
simultaneously exploration and exploitation leverages on organizational solutions encouraging a balance
between these two learning orientations. However, limited attention has as yet been devoted to the
investigation of contextual ambidexterity at the individual level of analysis. Starting from this gap, this
paper addresses the following research questions: How do individuals perceive the learning orientation
required of them by their job? Do individuals’ behaviors match their perceived orientation? How can the
matching/mismatching between perceptions and behaviors be explained? To address these issues a
multiple case study of 16 managers and assistants in the R&D and Sales units of four medium enterprises
located in Northeast Italy was carried out. Our findings show that perceptions and actual behaviors, as
dimensions of the personal ambidexterity, are independent of each other and can determine a
misalignment with the organizational ambidexterity. Accordingly, we propose a conceptual and
operational framework, in which the interplay among individual factors such as prior work experiences
and personal characteristics, through the mechanism of role stressors, mold both dimensions of personal
ambidexterity
ORIGIN : Radio sur Fibre pour un Réseau Local Domestique millimétrique
National audienceA low cost HAN infrastructure associating Optics and Radio for a wireless end connectivity to the very high bit rate services everywhere in the home.The Radio over Fiber systems enlarge the coverage of the millimeter-wave by transporting the radio signal from wireless devices onto an optical carrier for distribution over optical fibre to different remote antennas, called RoF transducer.Transporting the radio signals in their native format, provides remote antenna simplification and transparency to radio layer protocols