Ageing and relaxation times in disordered insulators

We focus on the slow relaxations observed in the conductance of disordered insulators at low temperature (especially granular aluminum films). They manifest themselves as a temporal logarithmic decrease of the conductance after a quench from high temperatures and the concomitant appearance of a field effect anomaly centered on the gate voltage maintained. We are first interested in ageing effects, i.e. the age dependence of the dynamical properties of the system. We stress that the formation of a second field effect anomaly at a different gate voltage is not a "history free" logarithmic (lnt) process, but departs from lnt in a way which encodes the system's age. The apparent relaxation time distribution extracted from the observed relaxations is thus not "constant" but evolves with time. We discuss what defines the age of the system and what external perturbation out of equilibrium does or does not rejuvenate it. We further discuss the problem of relaxation times and comment on the commonly used "two dip" experimental protocol aimed at extracting "characteristic times" for the glassy systems (granular aluminum, doped indium oxide...). We show that it is inoperable for systems like granular Al and probably highly doped InOx where it provides a trivial value only determined by the experimental protocol. But in cases where different values are obtained like in lightly doped InOx or some ultra thin metal films, potentially interesting information can be obtained, possibly about the "short time" dynamics of the different systems. Present ideas about the effect of doping on the glassiness of disordered insulators may also have to be reconsidered.Comment: to appear in the proceedings of the 14th International Conference on Transport and Interactions in Disordered Systems (TIDS14

B cells and monocytes from patients with active multiple sclerosis exhibit increased surface expression of both HERV-H Env and HERV-W Env, accompanied by increased seroreactivity

<p>Abstract</p> <p>Background</p> <p>The etiology of the neurogenerative disease multiple sclerosis (MS) is unknown. The leading hypotheses suggest that MS is the result of exposure of genetically susceptible individuals to certain environmental factor(s). Herpesviruses and human endogenous retroviruses (HERVs) represent potentially important factors in MS development. Herpesviruses can activate HERVs, and HERVs are activated in MS patients.</p> <p>Results</p> <p>Using flow cytometry, we have analyzed HERV-H Env and HERV-W Env epitope expression on the surface of PBMCs from MS patients with active and stable disease, and from control individuals. We have also analyzed serum antibody levels to the expressed HERV-H and HERV-W Env epitopes. We found a significantly higher expression of HERV-H and HERV-W Env epitopes on B cells and monocytes from patients with active MS compared with patients with stable MS or control individuals. Furthermore, patients with active disease had relatively higher numbers of B cells in the PBMC population, and higher antibody reactivities towards HERV-H Env and HERV-W Env epitopes. The higher antibody reactivities in sera from patients with active MS correlate with the higher levels of HERV-H Env and HERV-W Env expression on B cells and monocytes. We did not find such correlations for stable MS patients or for controls.</p> <p>Conclusion</p> <p>These findings indicate that both HERV-H Env and HERV-W Env are expressed in higher quantities on the surface of B cells and monocytes in patients with active MS, and that the expression of these proteins may be associated with exacerbation of the disease.</p

The COTUR project: remote sensing of offshore turbulence for wind energy application

The paper presents the measurement strategy and data set collected during the COTUR (COherence of TURbulence with lidars) campaign. This field experiment took place from February 2019 to April 2020 on the southwestern coast of Norway. The coherence quantifies the spatial correlation of eddies and is little known in the marine atmospheric boundary layer. The study was motivated by the need to better characterize the lateral coherence, which partly governs the dynamic wind load on multi-megawatt offshore wind turbines. During the COTUR campaign, the coherence was studied using land-based remote sensing technology. The instrument setup consisted of three long-range scanning Doppler wind lidars, one Doppler wind lidar profiler and one passive microwave radiometer. Both the WindScanner software and LidarPlanner software were used jointly to simultaneously orient the three scanner heads into the mean wind direction, which was provided by the lidar wind profiler. The radiometer instrument complemented these measurements by providing temperature and humidity profiles in the atmospheric boundary layer. The scanning beams were pointed slightly upwards to record turbulence characteristics both within and above the surface layer, providing further insight on the applicability of surface-layer scaling to model the turbulent wind load on offshore wind turbines. The preliminary results show limited variations of the lateral coherence with the scanning distance. A slight increase in the identified Davenport decay coefficient with the height is partly due to the limited pointing accuracy of the instruments. These results underline the importance of achieving pointing errors under 0.1∘ to study properly the lateral coherence of turbulence at scanning distances of several kilometres.publishedVersio

Seals of museums in eastern Turkey: Karaman, Nevsehir, Malatya, Maras | Sceaux des musées de la turquie orientale : Karaman, Nevşehir, Malatya, Maraş

Stemming from a survey program conducted by Esra Erdoğan in eastern Anatolia, this article presents the Byzantine lead seals housed in four Turkish museums : Malatya (formerly Melitene), Karaman (formerly Laranda), Kahramanmaraş (former Germanicea), and Nevşehir in Cappadocia. The interest in these collections is to gain new insight into the administrative organization of the Byzantine provinces established in these regions. All the seals examined are published here for the first time.Dans le cadre d’une enquête menée par Esra Erdoğan en Anatolie orientale, l’article présente les sceaux byzantins conservés dans quatre musées turcs : Malatya (l’ancienne Mélitène), Karaman (l’ancienne Laranda), Kahramanmaraş (l’ancienne Germanicée) et Nevşehir, en Cappadoce. L’intérêt de ces collections est d’offrir des perspectives renouvelées sur l’organisation administrative des provinces byzantines alors établies dans ces régions. Tous les sceaux ici présentés sont inédits.Cheynet Jean-Claude, Erdoğan Esra, Prigent Vivien. Sceaux des musées de la Turquie orientale : Karaman, Nevşehir, Malatya, Maraş. In: Revue des études byzantines, tome 74, 2016. pp. 287-326

Fibro-odontome améloblastique mandibulaire chez une patiente de 3 ans

International audienc

Evaluating neural network robustness with an architecture built around L-Neuro 2.3

International audienceWe study the sensitivity of an Artificial Neural Network designed to classify textures in satellite images, with respect to a particular kind of fault, so-called Single Event Upset. These faults are likely to occur as a consequence of interaction with radiations (space, nuclear) and result, for digital microcircuits, in a transient modification (bit flip) of memorized bits of information. Results of fault simulations performed on a digital implementation using a neural architecture built around the L-Neuro2.3 chip from PhilipsÝ are presented. Particularly, we study the impact on the network classification performances of errors in the bits of the input stimuli and synaptic weights, as well as on the memory storing the program emulating the neural network itself

Evidences of SEU tolerance for digital implementations of artificial neural networks: one year MPTB flight results

The Microelectronics and Photonics Testbed (MPTB) carrying twenty-four experiments on-board a scientific satellite has been in a high radiation orbit since November 1997. This paper presents one year flight results of two of these experiments programmed to emulate an Artificial Neural Network (ANN) devoted to texture analysis. Telemetred data provide evidences of the ANN intrinsic fault tolerance properties

Conséquences de l'obstruction nasale chez l'enfant

L'auteur passe en revue les conséquences morphogénétiques et fonctionnelles de la ventilation orale chez l'enfant