CEA Fontenay-aux-roses

Fontenay-aux-Roses, France

CEA Fontenay-aux-roses

Fontenay-aux-Roses, France
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Escartin C.,CEA Fontenay-aux-roses | Rouach N.,The Interdisciplinary Center
Frontiers in Neuroenergetics | Year: 2013

The strategic position of astrocytic processes between blood capillaries and neurons, provided the early insight that astrocytes play a key role in supplying energy substrates to neurons in an activity-dependent manner. The central role of astrocytes in neurometabolic coupling has been first established at the level of single cell. Since then, exciting recent work based on cellular imaging and electrophysiological recordings has provided new mechanistic insights into this phenomenon, revealing the crucial role of gap junction (GJ)-mediated networks of astrocytes. Indeed, astrocytes define the local availability of energy substrates by regulating blood flow. Subsequently, in order to efficiently reach distal neurons, these substrates can be taken up, and distributed through networks of astrocytes connected by GJs, a process modulated by neuronal activity. Astrocytic networks can be morphologically and/or functionally altered in the course of various pathological conditions, raising the intriguing possibility of a direct contribution from these networks to neuronal dysfunction. The present review upgrades the current view of neuroglial metabolic coupling, by including the recently unravelled properties of astroglial metabolic networks and their potential contribution to normal and pathological neuronal activity. © 2013 Escartin and Rouach.

Betermier M.,French National Center for Scientific Research | Betermier M.,University Paris - Sud | Bertrand P.,CEA Fontenay-aux-roses | Bertrand P.,French National Center for Scientific Research | And 3 more authors.
PLoS Genetics | Year: 2014

DNA double-strand breaks (DSBs) are harmful lesions leading to genomic instability or diversity. Non-homologous end-joining (NHEJ) is a prominent DSB repair pathway, which has long been considered to be error-prone. However, recent data have pointed to the intrinsic precision of NHEJ. Three reasons can account for the apparent fallibility of NHEJ: 1) the existence of a highly error-prone alternative end-joining process; 2) the adaptability of canonical C-NHEJ (Ku- and Xrcc4/ligase IV-dependent) to imperfect complementary ends; and 3) the requirement to first process chemically incompatible DNA ends that cannot be ligated directly. Thus, C-NHEJ is conservative but adaptable, and the accuracy of the repair is dictated by the structure of the DNA ends rather than by the C-NHEJ machinery. We present data from different organisms that describe the conservative/versatile properties of C-NHEJ. The advantages of the adaptability/versatility of C-NHEJ are discussed for the development of the immune repertoire and the resistance to ionizing radiation, especially at low doses, and for targeted genome manipulation. © 2014 Bétermier et al.

Yousef H.,CEA Fontenay-aux-roses | Boukallel M.,CEA Fontenay-aux-roses | Althoefer K.,King's College London
Sensors and Actuators, A: Physical | Year: 2011

As the field of robotics is expanding from the fixed environment of a production line to complex human environments, robots are required to perform increasingly human-like manipulation tasks, moving the state-of-the-art in robotics from grasping to advanced in-hand manipulation tasks such as regrasping, rotation and translation. To achieve advanced in-hand manipulation tasks, robotic hands are required to be equipped with distributed tactile sensing that can continuously provide information about the magnitude and direction of forces at all contact points between them and the objects they are interacting with. This paper reviews the state-of-the-art in force and tactile sensing technologies that can be suitable within the specific context of dexterous in-hand manipulation. In previous reviews of tactile sensing for robotic manipulation, the specific functional and technical requirements of dexterous in-hand manipulation, as compared to grasping, are in general not taken into account. This paper provides a review of models describing human hand activity and movements, and a set of functional and technical specifications for in-hand manipulation is defined. The paper proceeds to review the current state-of-the-art tactile sensor solutions that fulfil or can fulfil these criteria. An analytical comparison of the reviewed solutions is presented, and the advantages and disadvantages of different sensing technologies are compared. © 2011 Elsevier B.V. All rights reserved.

Bernstein K.A.,Columbia University | Gangloff S.,CEA Fontenay-aux-roses | Gangloff S.,French National Center for Scientific Research | Rothstein R.,Columbia University
Annual Review of Genetics | Year: 2010

The RecQ helicases are conserved from bacteria to humans and play a critical role in genome stability. In humans, loss of RecQ gene function is associated with cancer predisposition andor premature aging. Recent experiments have shown that the RecQ helicases function during distinct steps during DNA repair; DNA end resection, displacement-loop (D-loop) processing, branch migration, and resolution of double Holliday junctions (dHJs). RecQ function in these different processing steps has important implications for its role in repair of double-strand breaks (DSBs) that occur during DNA replication and meiosis, as well as at specific genomic loci such as telomeres. © 2010 by Annual Reviews. All rights reserved.

Herisse B.,ONERA | Hamel T.,University of Nice Sophia Antipolis | Mahony R.,Australian National University | Russotto F.-X.,CEA Fontenay-aux-roses
IEEE Transactions on Robotics | Year: 2012

This paper presents a nonlinear controller for a vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) that exploits a measurement optical flow to enable hover and landing control on a moving platform, such as, for example, the deck of a sea-going vessel. The VTOL vehicle is assumed to be equipped with a minimum sensor suite [i.e., a camera and an inertial measurement unit (IMU)], manoeuvring over a textured flat target plane. Two different tasks are considered in this paper. The first concerns the stabilization of the vehicle relative to the moving platform that maintains a constant offset from a moving reference. The second concerns regulation of automatic vertical landing onto a moving platform. Rigorous analysis of system stability is provided, and simulations are presented. Experimental results are provided for a quadrotor UAV to demonstrate the performance of the proposed control strategy. © 2006 IEEE.

Gras G.,CEA Fontenay-aux-roses | Kaul M.,Sanford Burnham Institute for Medical Research
Retrovirology | Year: 2010

HIV associated neurocognitive disorders and their histopathological correlates largely depend on the continuous seeding of the central nervous system with immune activated leukocytes, mainly monocytes/macrophages from the periphery. The blood-brain-barrier plays a critical role in this never stopping neuroinvasion, although it appears unaltered until the late stage of HIV encephalitis. HIV flux that moves toward the brain thus relies on hijacking and exacerbating the physiological mechanisms that govern blood brain barrier crossing rather than barrier disruption. This review will summarize the recent data describing neuroinvasion by HIV with a focus on the molecular mechanisms involved. © 2010 Gras and Kaul; licensee BioMed Central Ltd.

Peric D.,CEA Fontenay-aux-roses | Chvalova K.,CEA Fontenay-aux-roses | Rousselet G.,CEA Fontenay-aux-roses
Oncogene | Year: 2012

Micro-RNAs are deregulated in cancer cells, and some are either tumor suppressive or oncogenic. In addition, a link has been established between decreased expression of micro-RNAs and transformation, and several proteins of the RNA interference pathway have been shown to be haploinsufficient tumor suppressors. Oncogenic micro-RNAs (oncomiRs) could represent new therapeutic targets, and their identification is therefore crucial. However, structural and functional redundancy between micro-RNAs hampers approaches relying on individual micro-RNA inhibition. We reasoned that in cancer cells that depend on oncomiRs, impairing the micro-RNA pathway could lead to growth perturbation rather than increased tumorigenesis. Identifying such cells could allow functional analyses of individual micro-RNAs by complementation of the phenotypes observed upon global micro-RNA inhibition. Therefore, we developed episomal vectors coding for small hairpin RNAs targeting either Drosha or DGCR8, the two components of the microprocessor, the nuclear micro-RNA maturation complex. We identified cancer cell lines in which both vectors induced colony growth arrest. We then screened for individual micro-RNAs complementing this growth arrest, and identified miR-19a, miR-19b, miR-20a and miR-27b as major growth-sustaining micro-RNAs. However, the effect of miR-19a and miR-19b was only transient. In addition, embryonic stem cell-derived micro-RNAs with miR-20a seeds were much less efficient than miR-20a in sustaining cancer cell growth, a finding that contrasted with results obtained in stem cells. Finally, we showed that the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10, a shared target of miR-19 and miR-20, was functionally involved in the growth arrest induced by microprocessor inhibition. We conclude that our approach allowed to identify microprocessor-dependent cancer cells, which could be used to screen for growth-sustaining micro-RNAs. This complementation screen unveiled functional differences between homologous micro-RNAs. Phenotypic characterization of the complemented cells will allow precise functional studies of these micro-RNAs. © 2012 Macmillan Publishers Limited All rights reserved.

Galvan L.,CEA Fontenay-aux-roses
Neurobiology of aging | Year: 2012

Genes selectively expressed in the striatum may be involved in the preferential vulnerability of striatal neurons to Huntington's disease (HD). Here, we investigated whether perturbations of Capucin expression, which is enriched in the striatum and downregulated in Huntington's disease models, could modify the neurotoxicity induced by the injection of a lentiviral vector encoding a short N-terminal fragment of mutant Huntingtin (mHtt) into the mouse striatum. Neither constitutive Capucin deficiency in knockout mice nor lentiviral vector-mediated Capucin overexpression in the striatum of adult wild type mice significantly modified vulnerability to the mHtt fragment in vivo, suggesting that Capucin has no impact on mHtt toxicity. Copyright © 2012 Elsevier Inc. All rights reserved.

Chevalier F.,CEA Fontenay-aux-roses
Proteome Science | Year: 2010

Gel-based proteomic is the most popular and versatile method of global protein separation and quantification. This is a mature approach to screen the protein expression at the large scale, and a cheaper approach as compared with gel-free proteomics. Based on two independent biochemical characteristics of proteins, two-dimensional electrophoresis combines isoelectric focusing, which separates proteins according to their isoelectric point, and SDS-PAGE, which separates them further according to their molecular mass. The next typical steps of the flow of gel-based proteomics are spots visualization and evaluation, expression analysis and finally protein identification by mass spectrometry. For the study of differentially expressed proteins, two-dimensional electrophoresis allows simultaneously to detect, quantify and compare up to thousand protein spots isoforms, including post-translational modifications, in the same gel and in a wide range of biological systems. In this review article, the limits, benefits, and perspectives of gel-based proteomic approaches are discussed using concrete examples. © 2010 Chevalier; licensee BioMed Central Ltd.

CEA Fontenay-aux-roses | Date: 2010-12-01

The invention relates to a portable card writer (1) for writing data in a storage medium (12) of a card comprising a memory (18) for storing data sets of a plurality of cards, a writing head (14) for writing data in the storage medium (12), a control unit (17, 18) for controlling the reading of a data set from the memory (18) or a remote data server and for writing said data set in the storage medium (12) of a card, and an input device (3) for selecting a data set of a specific card and for initiating the writing of the selected data in the storage medium (12) of a multi-purpose card (11).

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