8 research outputs found

    Automatic correction of hand pointing in stereoscopic depth

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    In order to examine whether stereoscopic depth information could drive fast automatic correction of hand pointing, an experiment was designed in a 3D visual environment in which participants were asked to point to a target at different stereoscopic depths as quickly and accurately as possible within a limited time window (≤300 ms). The experiment consisted of two tasks: "depthGO" in which participants were asked to point to the new target position if the target jumped, and "depthSTOP" in which participants were instructed to abort their ongoing movements after the target jumped. The depth jump was designed to occur in 20% of the trials in both tasks. Results showed that fast automatic correction of hand movements could be driven by stereoscopic depth to occur in as early as 190 ms.This work was supported by the Grants from the National Natural Science Foundation of China (60970062 and 61173116) and the Doctoral Fund of Ministry of Education of China (20110072110014)

    Cerebellar Asymmetry and Cortical Connectivity in Monozygotic Twins with Discordant Handedness

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    Handedness differentiates patterns of neural asymmetry and interhemispheric connectivity in cortical systems that underpin manual and language functions. Contemporary models of cerebellar function incorporate complex motor behaviour and higher-order cognition, expanding upon earlier, traditional associations between the cerebellum and motor control. Structural MRI defined cerebellar volume asymmetries and correlations with corpus callosum (CC) size were compared in 19 pairs of adult female monozygotic twins strongly discordant for handedness (MZHd). Volume and asymmetry of cerebellar lobules were obtained using automated parcellation.CC area and regional widths were obtained from midsagittal planimetric measurements. Within the cerebellum and CC, neurofunctional distinctions were drawn between motor and higher-order cognitive systems. Relationships amongst regional cerebellar asymmetry and cortical connectivity (as indicated by CC widths) were investigated. Interactions between hemisphere and handedness in the anterior cerebellum were due to a larger right-greater-than-left hemispheric asymmetry in right-handed (RH) compared to left-handed (LH) twins. In LH twins only, anterior cerebellar lobule volumes (IV, V) for motor control were associated with CC size, particularly in callosal regions associated with motor cortex connectivity. Superior posterior cerebellar lobule volumes (VI, Crus I, Crus II, VIIb) showed no correlation with CC size in either handedness group. These novel results reflected distinct patterns of cerebellar-cortical relationships delineated by specific CC regions and an anterior-posterior cerebellar topographical mapping. Hence, anterior cerebellar asymmetry may contribute to the greater degree of bilateral cortical organisation of frontal motor function in LH individuals

    Hydrogen bonding in supramolecular nanoporous materials

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    This chapter provides an overview of the use of hydrogen bonds for the construction of nanoporous materials. These materials attract a great deal of interest because of their large surface area to volume ratio and their applications in areas such as filtration, separation, adsorption, catalysis, and ion conduction. Organic materials are especially appealing for these applications, because their properties can be tailored. The use of supramolecular interactions is required to control the organization of materials at the molecular level. Hydrogen bonds are ideal supramolecular interactions for the construction of these nanoporous materials, thanks to their directionality and reversibility. The directionality causes the positioning molecules in such a way that voids have been created in between the molecules, such as in two- and three-dimensional hydrogen bonded organic frameworks. In a second approach, hydrogen bonded template molecules have been removed from a polymer to create pores. This method is successfully applied to hydrogen bonded block copolymers and liquid crystalline polymers
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