5,839 research outputs found

    Brain, language, and handedness: a family affair

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    The left planum temporale is a marker of left hemisphere language specialization. We investigated the effect of individual handedness and familial sinistrality on left planum temporale surface area and found the size is reduced in proportion with the number of left-handed immediate family members and is lowest when one's mother is left-handed. This reduction is independent of an individual's handedness or sex and has no counterpart in the right hemisphere

    Bulking II: Classifications of Cellular Automata

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    This paper is the second part of a series of two papers dealing with bulking: a way to define quasi-order on cellular automata by comparing space-time diagrams up to rescaling. In the present paper, we introduce three notions of simulation between cellular automata and study the quasi-order structures induced by these simulation relations on the whole set of cellular automata. Various aspects of these quasi-orders are considered (induced equivalence relations, maximum elements, induced orders, etc) providing several formal tools allowing to classify cellular automata

    Origin of the slow dynamics and the aging of a soft glass

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    We study by light microscopy a soft glass consisting of a compact arrangement of polydisperse elastic spheres. We show that its slow and non-stationary dynamics results from the unavoidable small fluctuations of temperature, which induce intermittent local mechanical shear in the sample, because of thermal expansion and contraction. Temperature-induced shear provokes both reversible and irreversible rearrangements whose amplitude decreases with time, leading to an exponential slowing down of the dynamics with sample age.Comment: published in PRL 97, 238301, 200

    Projections of determinantal point processes

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    Let x={x(1),…,x(n)}\mathbf x=\{x^{(1)},\dots,x^{(n)}\} be a space filling-design of nn points defined in [0,1]d[0{,}1]^d. In computer experiments, an important property seeked for x\mathbf x is a nice coverage of [0,1]d[0{,}1]^d. This property could be desirable as well as for any projection of x\mathbf x onto [0,1]ι[0{,}1]^\iota for ι<d\iota<d . Thus we expect that xI={xI(1),…,xI(n)}\mathbf x_I=\{x_I^{(1)},\dots,x_I^{(n)}\}, which represents the design x\mathbf x with coordinates associated to any index set I⊆{1,…,d}I\subseteq\{1,\dots,d\}, remains regular in [0,1]ι[0{,}1]^\iota where ι\iota is the cardinality of II. This paper examines the conservation of nice coverage by projection using spatial point processes, and more specifically using the class of determinantal point processes. We provide necessary conditions on the kernel defining these processes, ensuring that the projected point process XI\mathbf{X}_I is repulsive, in the sense that its pair correlation function is uniformly bounded by 1, for all I⊆{1,…,d}I\subseteq\{1,\dots,d\}. We present a few examples, compare them using a new normalized version of Ripley's function. Finally, we illustrate the interest of this research for Monte-Carlo integration

    High-contrast imaging in polychromatic light with the self-coherent camera

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    Context. In the context of direct imaging of exoplanets, coronagraphs are commonly proposed to reach the required very high contrast levels. However, wavefront aberrations induce speckles in their focal plane and limit their performance. Aims. An active correction of these wavefront aberrations using a deformable mirror upstream of the coronagraph is mandatory. These aberrations need to be calibrated and focal-plane wavefront-sensing techniques in the science channel are being developed. One of these, the self-coherent camera, of which we present the latest laboratory results. Methods. We present here an enhancement of the method: we directly minimized the complex amplitude of the speckle field in the focal plane. Laboratory tests using a four-quadrant phase-mask coronagraph and a 32x32 actuator deformable mirror were conducted in monochromatic light and in polychromatic light for different bandwidths. Results. We obtain contrast levels in the focal plane in monochromatic light better than 3.10^-8 (RMS) in the 5 - 12 {\lambda}/D region for a correction of both phase and amplitude aberrations. In narrow bands (10 nm) the contrast level is 4.10^-8 (RMS) in the same region. Conclusions. The contrast level is currently limited by the amplitude aberrations on the bench. We identified several improvements that can be implemented to enhance the performance of our optical bench in monochromatic as well as in polychromatic light.Comment: 4 pages, 3 figures, accepted in Astronomy & Astrophysics (02/2014

    Effect of hole-shape irregularities on photonic crystal waveguides

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    The effect of irregular hole shape on the spectrum and radiation losses of a photonic crystal waveguide is studied using Bloch-mode expansion. Deviations from a perfectly circular hole are characterized by a radius fluctuation amplitude and correlation angle. It is found that the parameter which determines the magnitude of the effect of disorder is the standard deviation of the hole areas. Hence, for a fixed amplitude of the radius fluctuation around the hole, those effects are strongly dependent on the correlation angle of the irregular shape. This result suggests routes to potentially improve the quality of photonic crystal structures.Comment: 3 pages, 3 figure

    Essai de traitement de l'otacariose du chat par l'Ă©prinomectine

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    Le traitement de l'otacariose du chat (Otodectes cynotis) est difficile : le traitement auriculaire local est contraignant pour les propriétaires, les rechutes sont fréquentes en raison de la non-observance du traitement prescrit par le praticien. L'utilisation d'acaricides systémiques est une alternative intéressante, puisque un ou deux traitements seulement suffisent en général. Huit chats infestés ont été traités à l'éprinomectine en spot-on, à raison de 500 µg/kg, à J0 et J14. L'évolution clinique a été suivie pendant 56 jours chez les 8 animaux traités et chez les 7 témoins. Il ressort que ce traitement n'a pas eu une efficacité suffisante. Sur 8 des animaux infestés, nous avons trouvé des acariens sur le pelage, ce qui justifie la nécessité d'associer au traitement auriculaire un traitement acaricide du pelage
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