4,356 research outputs found

    Spatial eye–hand coordination during bimanual reaching is not systematically coded in either LIP or PRR

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    Significance When we reach for something, we also look at it. If we reach for two objects at once, one with each hand, we look first at one and then the other. It is not known which brain areas underlie this coordination. We studied two parietal areas known to be involved in eye and arm movements. Neither area was sensitive to the order in which the targets were looked at. This implies that coordinated saccades are driven by downstream areas and not by the parietal cortex as is commonly assumed.</jats:p

    Building equitable literate futures : home and school computer-mediated literacy practices and disadvantage

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    This paper examines the complex connections between literacy practices, the use of information and communication technologies (ICTs) and disadvantage. It reports the findings of a year-long study which investigated the ways in which four families use ICTs to engage with formal and informal literacy learning in home and school settings. The research set out to explore what it is about computer-mediated literacy practices at home and at school in disadvantaged communities that make a difference in school success. The findings demonstrate that the \u27socialisation\u27 of the technology - its appropriation into existing family norms, values and lifestyles - varied from family to family. Having access to ICTs at home was not sufficient for the young people and their families to overcome the so-called \u27digital divide\u27. Clearly, we are seeing shifts in the meaning of \u27disadvantage\u27 in a globalised world mediated by the use of new technologies. New definitions of disadvantage that take account not only of access to the new technologies but also include calibrated understandings of what constitutes the access are required. The article concludes that old inequalities have not disappeared, but are playing out in new ways in the context of the networked society.<br /

    A study of influence line analysis of stresses in a cantilever steel highway bridge

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    As its name implies, this thesis introduces to the reader the basic conceptions and principles of the use of influence line analysis of the structural theory relating to calculation of stresses in a steel cantilever bridge truss --Preface, page i

    Melting of cognetic depleted and enriched reservoirs and the production of high Ti Mare basalts

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    Implicit in current understanding of the location of terrestrial enriched and depleted reservoirs is the notion that they are spatially separated. The depleted reservoir on Earth is situated in the upper mantle, and the complementary enriched reservoir is located in the crust. However, Earth reservoirs are continually being modified by recycling driven by mantle convection. The Moon is demonstrably different from Earth in that its evolution was arrested relatively early - effectively with 1.5 Ga of its formation. It is possible that crystallized trapped liquids (from the late stages of a magma ocean) have been preserved as LILE-enriched portions of the lunar mantle. This would lead to depleted (cumulate) and enriched (magma ocean residual liquid) reservoirs in the lunar upper mantle. There is no evidence for significant recycling from the highland crust back into the mantle. Therefore, reservoirs created at the Moon's inception may have remained intact for over 4.0 Ga. The topics discussed include the following: (1) radiogenic isotopes in high-Ti mare basalts; (2) formation of cogenetic depleted and enriched reservoirs; and (3) melting of the source to achieve high-Ti mare basalts

    Multimodal Representation of Space in the Posterior Parietal Cortex and its use in Planning Movements

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    Recent experiments are reviewed that indicate that sensory signals from many modalities, as well as efference copy signals from motor structures, converge in the posterior parietal cortex in order to code the spatial locations of goals for movement. These signals are combined using a specific gain mechanism that enables the different coordinate frames of the various input signals to be combined into common, distributed spatial representations. These distributed representations can be used to convert the sensory locations of stimuli into the appropriate motor coordinates required for making directed movements. Within these spatial representations of the posterior parietal cortex are neural activities related to higher cognitive functions, including attention. We review recent studies showing that the encoding of intentions to make movements is also among the cognitive functions of this area

    neoKREEP: A new lunar component at Apollo 17

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    The Apollo 11 (Mare Tranquillitatis) and Apollo 17 (Mare Serenitatis) landing sites are important as the only sources of high-Ti basalt visited by the Apollo missions. The lunar high-Ti basalts (greater than 6 percent TiO2) have no volumetrically comparable analogs among terrestrial basalts and require the presence of ilmenite in the source region, probably representing cumulates produced late in the crystallization of the lunar magma ocean. Six principal groups of high-Ti basalts are described, three from each of the two sites
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