1,021 research outputs found

    Making the Most of Out-of-School Time

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    Evaluates the MOST initiative, which was launched in 1994 in Boston, Chicago, and Seattle, to improve the quantity and quality of before- and after-school programs for 5- to 14-year-olds, especially for families in low-income communities

    Neighborhood-Based Initiative to Address Poverty: Lessons From Experience

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    The neighborhood has long been an important locus for efforts to address the causes and consequences of poverty in American society. Over the course of the past century neighborhood- based initiatives have been called on to reduce class conflict, counter feelings of alienation, localize control of social institutions, create jobs and reverse neighborhood economic decline, improve human services, and address a variety of specific poverty-related problems, ranging from infant mortality to juvenile delinquency. In this essay I draw on the historical experience with neighborhood initiative to illuminate its strengths and limitations as a strategy for addressing poverty and its correlates. I also use the particular history to point up enduring dilemmas in American society\u27s efforts to address poverty

    It Takes a Whole Society: Opening Up the Learning Landscape in the High School Years

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    Argues for providing a more meaningful high school learning experience by designing innovative curricula, blending academic and applied learning, engaging disadvantaged learners, integrating career and technical education, and offering apprenticeships

    The resource theory of informational nonequilibrium in thermodynamics

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    We review recent work on the foundations of thermodynamics in the light of quantum information theory. We adopt a resource-theoretic perspective, wherein thermodynamics is formulated as a theory of what agents can achieve under a particular restriction, namely, that the only state preparations and transformations that they can implement for free are those that are thermal at some fixed temperature. States that are out of thermal equilibrium are the resources. We consider the special case of this theory wherein all systems have trivial Hamiltonians (that is, all of their energy levels are degenerate). In this case, the only free operations are those that add noise to the system (or implement a reversible evolution) and the only nonequilibrium states are states of informational nonequilibrium, that is, states that deviate from the maximally mixed state. The degree of this deviation we call the state's nonuniformity; it is the resource of interest here, the fuel that is consumed, for instance, in an erasure operation. We consider the different types of state conversion: exact and approximate, single-shot and asymptotic, catalytic and noncatalytic. In each case, we present the necessary and sufficient conditions for the conversion to be possible for any pair of states, emphasizing a geometrical representation of the conditions in terms of Lorenz curves. We also review the problem of quantifying the nonuniformity of a state, in particular through the use of generalized entropies. Quantum state conversion problems in this resource theory can be shown to be always reducible to their classical counterparts, so that there are no inherently quantum-mechanical features arising in such problems. This body of work also demonstrates that the standard formulation of the second law of thermodynamics is inadequate as a criterion for deciding whether or not a given state transition is possible.Comment: 51 pages, 9 figures, Revised Versio

    Identification, discrimination, and selective adaptation of simultaneous musical intervals

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    Four experiments investigated perception of major and minor thirds whose component tones were sounded simultaneously. Effects akin to categorical perception of speech sounds were found. In the first experiment, musicians demonstrated relatively sharp category boundaries in identification and peaks near the boundary in discrimination tasks of an interval continuum where the bottom note was always an F and the top note varied from A to A flat in seven equal logarithmic steps. Nonmusicians showed these effects only to a small extent. The musicians showed higher than predicted discrimination performance overall, and reaction time increases at category boundaries. In the second experiment, musicians failed to consistently identify or discriminate thirds which varied in absolute pitch, but retained the proper interval ratio. In the last two experiments, using selective adaptation, consistent shifts were found in both identification and discrimination, similar to those found in speech experiments. Manipulations of adapting and test showed that the mechanism underlying the effect appears to be centrally mediated and confined to a frequency-specific level. A multistage model of interval perception, where the first stages deal only with specific pitches may account for the results

    Mental Concerts: Musical Imagery and Auditory Cortex

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    Most people intuitively understand what it means to “hear a tune in your head.” Converging evidence now indicates that auditory cortical areas can be recruited even in the absence of sound and that this corresponds to the phenomenological experience of imagining music. We discuss these findings as well as some methodological challenges. We also consider the role of core versus belt areas in musical imagery, the relation between auditory and motor systems during imagery of music performance, and practical implications of this research

    Instabilities in droplets spreading on gels

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    We report a novel surface-tension driven instability observed for droplets spreading on a compliant substrate. When a droplet is released on the surface of an agar gel, it forms arms/cracks when the ratio of surface tension gradient to gel strength is sufficiently large. We explore a range of gel strengths and droplet surface tensions and find that the onset of the instability and the number of arms depend on the ratio of surface tension to gel strength. However, the arm length grows with an apparently universal law L ~ t^{3/4}

    Cross-shelf circulation on the continental shelf off Northwest Africa during upwelling

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    During 10 March-6 April, 1974 simultaneous current records were obtained from 12 current meters, placed between 0.8 m and 67 m, in water approximately 75 m deep at 21°40\u27N, 17°18\u27W, about 32 km from the coast of Mauritania. Throughout the experiment the vertical stratification and horizontal density gradient were weak, and the winds were generally favorable for coastal upwelling...

    Common parietal activation in musical mental transformations across pitch and time

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    We previously observed that mental manipulation of the pitch level or temporal organization of melodies results in functional activation in the human intraparietal sulcus (IPS), a region also associated with visuospatial transformation and numerical calculation. Two outstanding questions about these musical transformations are whether pitch and time depend on separate or common processing in IPS, and whether IPS recruitment in melodic tasks varies depending upon the degree of transformation required (as it does in mental rotation). In the present study we sought to answer these questions by applying functional magnetic resonance imaging while musicians performed closely matched mental transposition (pitch transformation) and melody reversal (temporal transformation) tasks. A voxel-wise conjunction analysis showed that in individual subjects, both tasks activated overlapping regions in bilateral IPS, suggesting that a common neural substrate subserves both types of mental transformation. Varying the magnitude of mental pitch transposition resulted in variation of IPS BOLD signal in correlation with the musical key-distance of the transposition, but not with the pitch distance, indicating that the cognitive metric relevant for this type of operation is an abstract one, well described by music-theoretic concepts. These findings support a general role for the IPS in systematically transforming auditory stimulus representations in a nonspatial context. (C) 2013 Elsevier Inc. All rights reserved
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