2,973 research outputs found

    Age of second language acquisition affects nonverbal conflict processing in children : an fMRI study

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    Background: In their daily communication, bilinguals switch between two languages, a process that involves the selection of a target language and minimization of interference from a nontarget language. Previous studies have uncovered the neural structure in bilinguals and the activation patterns associated with performing verbal conflict tasks. One question that remains, however is whether this extra verbal switching affects brain function during nonverbal conflict tasks. Methods: In this study, we have used fMRI to investigate the impact of bilingualism in children performing two nonverbal tasks involving stimulus-stimulus and stimulus-response conflicts. Three groups of 8-11-year-old children - bilinguals from birth (2L1), second language learners (L2L), and a control group of monolinguals (1L1) - were scanned while performing a color Simon and a numerical Stroop task. Reaction times and accuracy were logged. Results: Compared to monolingual controls, bilingual children showed higher behavioral congruency effect of these tasks, which is matched by the recruitment of brain regions that are generally used in general cognitive control, language processing or to solve language conflict situations in bilinguals (caudate nucleus, posterior cingulate gyrus, STG, precuneus). Further, the activation of these areas was found to be higher in 2L1 compared to L2L. Conclusion: The coupling of longer reaction times to the recruitment of extra language-related brain areas supports the hypothesis that when dealing with language conflicts the specialization of bilinguals hampers the way they can process with nonverbal conflicts, at least at early stages in life

    Correlation Analysis of Enzyme activities and Deconstruction of Ammonia-pretreated Switchgrass by Bacterial-fungal Communities

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    The mixed microbial communities that occur naturally on lignocellulosic feedstocks can provide feedstock-specific enzyme mixtures to saccharify lignocelluloses. Bacterial-fungal communities were enriched from switchgrass bales to deconstruct ammonia-pretreated switchgrass (DSG). Correlation analysis was carried out to elucidate the relationship between microbial decomposition of DSG by these communities, enzymatic activities produced and enzymatic saccharification of DSG using these enzyme mixtures. Results of the analysis showed that β glucosidase activities and xylosidase activities limited the extent of microbial deconstruction and enzymatic saccharification of DSG. The results also underlined the importance of ligninase activity for the enzymatic saccharification of pretreated lignocellulosic feedstock. The bacterial fungal communities developed in this research can be used to produce enzyme mixtures to deconstruct DSG, and the results from the correlation analysis can be used to optimize these enzyme mixtures for efficient saccharification of DSG to produce second-generation biofuels

    Billy Elliot The Musical: visual representations of working-class masculinity and the all-singing, all-dancing bo[d]y

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    According to Cynthia Weber, ‘[d]ance is commonly thought of as liberating, transformative, empowering, transgressive, and even as dangerous’. Yet ballet as a masculine activity still remains a suspect phenomenon. This paper will challenge this claim in relation to Billy Elliot the Musical and its critical reception. The transformation of the visual representation of the human body on stage (from an ephemeral existence to a timeless work of art) will be discussed and analysed vis-a-vis the text and sub-texts of Stephen Daldry’s direction and Peter Darling’s choreography. The dynamics of working-class masculinity will be contextualised within the framework of the family, the older female, the community, the self and the act of dancing itself

    Quantum Dynamics without the Wave Function

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    When suitably generalized and interpreted, the path-integral offers an alternative to the more familiar quantal formalism based on state-vectors, selfadjoint operators, and external observers. Mathematically one generalizes the path-integral-as-propagator to a {\it quantal measure} Ο\mu on the space Ί\Omega of all ``conceivable worlds'', and this generalized measure expresses the dynamics or law of motion of the theory, much as Wiener measure expresses the dynamics of Brownian motion. Within such ``histories-based'' schemes new, and more ``realistic'' possibilities open up for resolving the philosophical problems of the state-vector formalism. In particular, one can dispense with the need for external agents by locating the predictive content of Ο\mu in its sets of measure zero: such sets are to be ``precluded''. But unrestricted application of this rule engenders contradictions. One possible response would remove the contradictions by circumscribing the application of the preclusion concept. Another response, more in the tradition of ``quantum logic'', would accommodate the contradictions by dualizing Ί\Omega to a space of ``co-events'' and effectively identifying reality with an element of this dual space.Comment: plainTeX, 24 pages, no figures. To appear in a special volume of {\it Journal of Physics A: Mathematical and General} entitled ``The Quantum Universe'' and dedicated to Giancarlo Ghirardi on the occasion of his 70th birthday. Most current version is available at http://www.physics.syr.edu/~sorkin/some.papers/ (or wherever my home-page may be

    Comparison of Electrical Moisture Meters for Baled Alfalfa Hay

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    A primary concern in producing quality alfalfa hay is moisture measurement. Some precision in moisture measurement is required since hay can be too wet, leading to dry matter and quality loss through mold; it can be too dry, leading to shatter loss during baling, handling and storage. Moisture measurement in hay can take many forms. One form of subjective (personal judgment) evaluation is brittleness of leaves and stems in the windrow or bale. Typical objective methods consist of electric meters with calibration curves and oven drying

    A Bell Inequality Analog in Quantum Measure Theory

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    One obtains Bell's inequalities if one posits a hypothetical joint probability distribution, or {\it measure}, whose marginals yield the probabilities produced by the spin measurements in question. The existence of a joint measure is in turn equivalent to a certain causality condition known as ``screening off''. We show that if one assumes, more generally, a joint {\it quantal measure}, or ``decoherence functional'', one obtains instead an analogous inequality weaker by a factor of 2\sqrt{2}. The proof of this ``Tsirel'son inequality'' is geometrical and rests on the possibility of associating a Hilbert space to any strongly positive quantal measure. These results lead both to a {\it question}: ``Does a joint measure follow from some quantal analog of `screening off'?'', and to the {\it observation} that non-contextual hidden variables are viable in histories-based quantum mechanics, even if they are excluded classically.Comment: 38 pages, TeX. Several changes and added comments to bring out the meaning more clearly. Minor rewording and extra acknowledgements, now closer to published versio

    Causation, Measurement Relevance and No-conspiracy in EPR

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    In this paper I assess the adequacy of no-conspiracy conditions employed in the usual derivations of the Bell inequality in the context of EPR correlations. First, I look at the EPR correlations from a purely phenomenological point of view and claim that common cause explanations of these cannot be ruled out. I argue that an appropriate common cause explanation requires that no-conspiracy conditions are re-interpreted as mere common cause-measurement independence conditions. In the right circumstances then, violations of measurement independence need not entail any kind of conspiracy (nor backwards in time causation). To the contrary, if measurement operations in the EPR context are taken to be causally relevant in a specific way to the experiment outcomes, their explicit causal role provides the grounds for a common cause explanation of the corresponding correlations.Comment: 20 pages, 1 figur

    Measurements of Sunyaev-Zel'dovich Effect Scaling Relations for Clusters of Galaxies

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    We present new measurements of the Sunyaev-Zel'dovich (SZ) effect from clusters of galaxies using the Sunyaev-Zel'dovich Infrared Experiment (SuZIE II). We combine these new measurements with previous cluster observations with the SuZIE instrument to form a sample of 15 clusters of galaxies. For this sample we calculate the central Comptonization, y, and the integrated SZ flux decrement, S, for each of our clusters. We find that the integrated SZ flux is a more robust observable derived from our measurements than the central Comptonization due to inadequacies in the spatial modelling of the intra-cluster gas with a standard Beta model. This is highlighted by comparing our central Comptonization results with values calculated from measurements using the BIMA and OVRO interferometers. On average, the SuZIE calculated central Comptonizations are approximately 60% higher in the cooling flow clusters than the interferometric values, compared to only approximately 12% higher in the non-cooling flow clusters. We believe this discrepancy to be in large part due to the spatial modelling of the intra-cluster gas. From our cluster sample we construct y-T and S-T scaling relations. The y-T scaling relation is inconsistent with what we would expect for self-similar clusters; however this result is questionable because of the large systematic uncertainty in the central Comptonization. The S-T scaling relation has a slope and redshift evolution consistent with what we expect for self-similar clusters with a characteristic density that scales with the mean density of the universe. We rule out zero redshift evolution of the S-T relation at 90% confidence.Comment: Accepted to Astrophysical Journal. 52 pages, 14 tables, 7 figures ;replaced to match ApJ accepted versio

    Parallel Unsmoothed Aggregation Algebraic Multigrid Algorithms on GPUs

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    We design and implement a parallel algebraic multigrid method for isotropic graph Laplacian problems on multicore Graphical Processing Units (GPUs). The proposed AMG method is based on the aggregation framework. The setup phase of the algorithm uses a parallel maximal independent set algorithm in forming aggregates and the resulting coarse level hierarchy is then used in a K-cycle iteration solve phase with a ℓ1\ell^1-Jacobi smoother. Numerical tests of a parallel implementation of the method for graphics processors are presented to demonstrate its effectiveness.Comment: 18 pages, 3 figure

    Foraging behavior and Doppler shift compensation in echolocating hipposiderid bats, I-Iipposideros bicolor and I-Iipposideros speoris

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    1. Two hipposiderid bats,H. bicolor andH. speoris, were observed in their natural foraging areas in Madurai (South India). Both species hunt close together near the foliage of trees and bushes but they differ in fine structure of preferred hunting space:H. bicolor hunts within the foliage, especially whenH. speoris is active at the same time, whereasH. speoris never flies in dense vegetation but rather in the more open area (Fig. 1, Table 1). 2. Both species emit CF/FM-sounds containing only one harmonic component in almost all echolocation situations. The CF-parts of CF/FM-sounds are species specific within a band of 127–138 kHz forH. speoris and 147–159 kHz forH. bicolor (Tables 2 and 3). 3. H. speoris additionally uses a complex harmonic sound during obstacle avoidance and during laboratory tests for Doppler shift compensation.H. bicolor consistently emits CF/FM-sounds in these same situations (Fig. 2). 4. Both hipposiderid bats respond to Doppler shifts in the returning echoes by lowering the frequency of the emitted sounds (Fig. 3). However, Doppler compensations are incomplete as the emitted frequencies are decreased by only 55% and 56% (mean values) of the full frequency shifts byH. speoris andH, bicolor, respectively. 5. The differences in Doppler shift compensation, echolocating and hunting behavior suggest thatH. speoris is less specialized on echolocation with CF/FM-sounds thanH. bicolor
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