662 research outputs found

    Leaf Menus: Linear Menus with Stroke Shortcuts for Small Handheld Devices

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    International audienceThis paper presents Leaf menu, a new type of contextual linear menu that supports curved gesture shortcuts. By providing an alternative to keyboard shortcuts, the Leaf menus can be used for the selection of commands on tabletops, but its key benefit is its adequacy to small handheld touchscreen devices (PDA, Smartphone). Indeed Leaf menus define a compact and known layout inherited from linear menus, they support precise finger interaction, they manage occlusion and they can be used in close proximity to the screen borders. Moreover, by providing stroke shortcuts, they favour the selection of frequent commands in expert mode and make eye-free selection possible

    Immersive Teleoperation of the Eye Gaze of Social Robots Assessing Gaze-Contingent Control of Vergence, Yaw and Pitch of Robotic Eyes

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    International audienceThis paper presents a new teleoperation system – called stereo gaze-contingent steering (SGCS) – able to seamlessly control the vergence, yaw and pitch of the eyes of a humanoid robot – here an iCub robot – from the actual gaze direction of a remote pilot. The video stream captured by the cameras embedded in the mobile eyes of the iCub are fed into an HTC Vive R Head-Mounted Display equipped with an SMI R binocular eye-tracker. The SGCS achieves the effective coupling between the eye-tracked gaze of the pilot and the robot's eye movements. SGCS both ensures a faithful reproduction of the pilot's eye movements – that is perquisite for the readability of the robot's gaze patterns by its interlocutor – and maintains the pilot's oculomotor visual clues – that avoids fatigue and sickness due to sensorimotor conflicts. We here assess the precision of this servo-control by asking several pilots to gaze towards known objects positioned in the remote environment. We demonstrate that we succeed in controlling vergence with similar precision as eyes' azimuth and elevation. This system opens the way for robot-mediated human interactions in the personal space, notably when objects in the shared working space are involved

    Foamed Nanocomposites for EMI Shielding Applications

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    INTRODUCTION : The addition of nanoparticles having specific properties inside a matrix with different properties creates a novel material that exhibits hybrid and even new properties. The nanocomposites presented in this paper combine the properties of foamed polymers (inexpensive, lightweight, easy to mould into any desired shape, etc.) with those of carbon nanotubes (CNTs). The addition of any conductive nanoparticles to an otherwise insulating matrix leads to a significant increase of the electrical conductivity. But CNTs have a very high aspect ratio; a much lower content of CNTs is therefore required to get the same conductivity increase as the one obtained with more compact nanoparticles. This is especially interesting for EMI shielding materials since, as will be explained in further details in this chapter, it is desirable for such materials to have a high conductivity but a low dielectric constant, in order to minimize the electromagnetic power outside the shield casing but also to minimize the power reflected back inside the casing, as is explained in section 2. In particular, two parameters of interest when comparing shielding materials are detailed and discussed. The polymer/CNTs nanocomposites were fabricated and characterized using a two-step diagnostic method. They were first characterized in their solid form, i.e. before the foaming process and the most interesting polymer matrices (with embedded CNTs) could be selected. This way, only the promising blends were foamed, therefore avoiding the unnecessary fabrication of a number of foams. These selected blends were foamed and then characterized. The samples, both solid and foamed, are described and their fabrication processes are briefly explained in section 3 while the characterization methods are shown in section 4. A simple electrical model is given and explained in section 5 and an optimized topology for the foams is also proposed in the second part of the same section. The measurement results for the solids and for the mono-layered and multi-layered foams are summarized and discussed in section 6. They are then compared to results obtained using the electrical model presented in the previous section and they are also correlated to rheological characterizations

    Model and method to predict the turbulent kinetic energy induced by tidal currents, application to the wave-induced turbulence

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    A prediction model for the turbulent kinetic energy (TKE) induced by tidal-currents is proposed as a function of the barotropic velocity only, along with a robust method evaluating the different parameters involved using Acoustic Doppler Current Profiler (ADCP) measurements from Alderney Race. We find that the model is able to reproduce correctly the TKE profiles with coefficients of correlation on average higher than 0.90 and normalised root-mean-square errors (NRMSE) less than 14%. Different profiles are also tested for the mean velocity, no satisfactory prediction model is found but we are able to have decent estimates of the velocity shear and friction velocity. Two applications are then carried out. First the turbulent budget terms are estimated and discussed. We identify the turbulent production and dissipation of TKE as the most important mechanisms, then we discuss the validity of several theoretical results derived for isotropic turbulence for this application. A strong departure for the estimation of the turbulent dissipation is notably found and explained by the turbulent anisotropy. At last the prediction model for the TKE is used to infer the wave-induced TKE. We show the importance of removing the tidal component, waves can have a strong influence down to mid-depth

    Prion Proteins and Neuronal Death in the Cerebellum

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    The cellular prion protein, a major player in the neuropathology of prion diseases, is believed to control both death and survival pathways in central neurons. However, the cellular and molecular mechanisms underlying these functions remain to be deciphered. This chapter presents cytopathological studies of the neurotoxic effects of infectious prions and cellular prion protein-deficiency on cerebellar neurons in wild-type and transgenic mice. The immunochemical and electron microscopy data collected in situ and ex vivo in cultured organotypic cerebellar slices indicate that an interplay between apoptotic and autophagic pathways is involved in neuronal death induced either by the infectious prions or by prion protein-deficiency

    Internal vein texture and vein evolution of the epithermal Shila-Paula district, southern Peru.

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    The epithermal Shila-Paula Au–Ag district is characterized by numerous veins hosted in Tertiary volcanic rocks of the Western Cordillera (southern Peru). Field studies of the ore bodies reveal a systematic association of a main E–W vein with secondary N55–60°W veins—two directions that are also reflected by the orientation of fluid-inclusion planes in quartz crystals of the host rock. In areas where this pattern is not recognized, such as the Apacheta sector, vein emplacement seems to have been guided by regional N40°E and N40°W fractures. Two main vein-filling stages are identified. stage 1 is a quartz–adularia–pyrite–galena–sphalerite–chalcopyrite–electrum–Mn silicate–carbonate assemblage that fills the main E–W veins. stage 2, which contains most of the precious-metal mineralization, is divided into pre-bonanza and bonanza substages. The pre-bonanza substage consists of a quartz–adularia–carbonate assemblage that is observed within the secondary N45–60°W veins, in veinlets that cut the stage 1 assemblage, and in final open-space fillings. The two latter structures are finally filled by the bonanza substage characterized by a Fe-poor sphalerite–chalcopyrite–pyrite–galena–tennantite–tetrahedrite–polybasite–pearceite–electrum assemblage. The ore in the main veins is systematically brecciated, whereas the ore in the secondary veins and geodes is characteristic of open-space crystallization. Microthermometric measurements on sphalerite from both stages and on quartz and calcite from stage 2 indicate a salinity range of 0 to 15.5 wt% NaCl equivalent and homogenization temperatures bracketed between 200 and 330°C. Secondary CO2-, N2- and H2S-bearing fluid inclusions are also identified. The age of vein emplacement, based on 40Ar/39Ar ages obtained on adularia of different veins, is estimated at around 11 Ma, with some overlap between adularia of stage 1 (11.4±0.4 Ma) and of stage 2 (10.8±0.3 Ma). A three-phase tectonic model has been constructed to explain the vein formation. Phase 1 corresponds to the assumed development of E–W sinistral shear zones and associated N60°W cleavages under the effects of a NE–SW shortening direction that is recognized at Andean scale. These structures contain the stage 1 ore assemblage that was brecciated during ongoing deformation. Phase 2 is a reactivation of earlier structures under a NW–SE shortening direction that allowed the reopening of the preexisting schistosity and the formation of scarce N50°E-striking S2-cleavage planes filled by the stage 2 pre-bonanza minerals. Phase 3 coincides with the bonanza ore emplacement in the secondary N45–60°W veins and also in open-space in the core of the main E–W veins. Our combined tectonic, textural, mineralogical, fluid-inclusion, and geochronological study presents a complete model of vein formation in which the reactivation of previously formed tectonic structures plays a significant role in ore formation

    Immersive Teleoperation of the Eye Gaze of Social Robots Assessing Gaze-Contingent Control of Vergence, Yaw and Pitch of Robotic Eyes

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    International audienceThis paper presents a new teleoperation system – called stereo gaze-contingent steering (SGCS) – able to seamlessly control the vergence, yaw and pitch of the eyes of a humanoid robot – here an iCub robot – from the actual gaze direction of a remote pilot. The video stream captured by the cameras embedded in the mobile eyes of the iCub are fed into an HTC Vive R Head-Mounted Display equipped with an SMI R binocular eye-tracker. The SGCS achieves the effective coupling between the eye-tracked gaze of the pilot and the robot's eye movements. SGCS both ensures a faithful reproduction of the pilot's eye movements – that is perquisite for the readability of the robot's gaze patterns by its interlocutor – and maintains the pilot's oculomotor visual clues – that avoids fatigue and sickness due to sensorimotor conflicts. We here assess the precision of this servo-control by asking several pilots to gaze towards known objects positioned in the remote environment. We demonstrate that we succeed in controlling vergence with similar precision as eyes' azimuth and elevation. This system opens the way for robot-mediated human interactions in the personal space, notably when objects in the shared working space are involved

    Subcutaneous phaeohyphomycosis due to Phialemoniopsis ocularis successfully treated by voriconazole

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    International audienceWe report a case of subcutaneous infection in a 67 year-old Cambodian man who presented with a 5-month history of swelling of the right foot. Histopathology was compatible with phaeohyphomycosis and the hyphomycete Phialemoniopsis ocularis was identified by the means of morphological and molecular techniques. The patient responded well to a 6-month oral treatment with voriconazole alone
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