16,828 research outputs found

    Literacy: A cultural influence on functional left-right differences in the inferior parietal cortex

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    The current understanding of hemispheric interaction is limited. Functional hemispheric specialization is likely to depend on both genetic and environmental factors. In the present study we investigated the importance of one factor, literacy, for the functional lateralization in the inferior parietal cortex in two independent samples of literate and illiterate subjects. The results show that the illiterate group are consistently more right-lateralized than their literate controls. In contrast, the two groups showed a similar degree of left-right differences in early speech-related regions of the superior temporal cortex. These results provide evidence suggesting that a cultural factor, literacy, influences the functional hemispheric balance in reading and verbal working memory-related regions. In a third sample, we investigated grey and white matter with voxel-based morphometry. The results showed differences between literacy groups in white matter intensities related to the mid-body region of the corpus callosum and the inferior parietal and parietotemporal regions (literate > illiterate). There were no corresponding differences in the grey matter. This suggests that the influence of literacy on brain structure related to reading and verbal working memory is affecting large-scale brain connectivity more than grey matter per se

    Quantum Evolution of Inhomogeneities in Curved Space

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    We obtain the renormalized equations of motion for matter and semi-classical gravity in an inhomogeneous space-time. We use the functional Schrodinger picture and a simple Gaussian approximation to analyze the time evolution of the λϕ4\lambda\phi^4 model, and we establish the renormalizability of this non-perturbative approximation. We also show that the energy-momentum tensor in this approximation is finite once we consider the usual mass and coupling constant renormalizations, without the need of further geometrical counter-terms.Comment: 22 page

    Cognitive processing in literate and illiterate subjects: A review of some recent behavioral and functional neuroimaging data

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    The study of illiterate subjects, which for specific socio-cultural reasons did not have the opportunity to acquire basic reading and writing skills, represents one approach to study the interaction between neurobiological and cultural factors in cognitive development and the functional organization of the human brain. In addition the naturally occurring illiteracy may serve as a model for studying the influence of alphabetic orthography on auditory-verbal language. In this paper we have reviewed some recent behavioral and functional neuroimaging data indicating that learning an alphabetic written language modulates the auditory-verbal language system in a non-trivial way and provided support for the hypothesis that the functional architecture of the brain is modulated by literacy. We have also indicated that the effects of literacy and formal schooling is not limited to language related skills but appears to affect also other cognitive domains. In particular, we indicate that formal schooling influences 2D but not 3D visual naming skills. We have also pointed to the importance of using ecologically relevant tasks when comparing literate and illiterate subjects. We also demonstrate the applicability of a network approach in elucidating differences in the functional organization of the brain between groups. The strength of such an approach is the ability to study patterns of interactions between functionally specialized brain regions and the possibility to compare such patterns of brain interactions between groups or functional states. This complements the more commonly used activation approach to functional neuroimaging data, which characterize functionally specialized regions, and provides important data characterizing the functional interactions between these regions

    Final state interaction in D+Kπ+π+D^+\to K^-\pi^+\pi^+ with KπK\pi I=1/2 and 3/2 channels

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    The final state interaction contribution to D+D^+ decays is computed for the Kπ+π+K^-\pi^+\pi^+ channel within a light-front relativistic three-body model for the final state interaction. The rescattering process between the kaon and two pions in the decay channel is considered. The off-shell decay amplitude is a solution of a four-dimensional Bethe-Salpeter equation, which is decomposed in a Faddeev form. The projection onto the light-front of the coupled set of integral equations is performed via a quasi-potential approach. The S-wave KπK\pi interaction is introduced in the resonant isospin 1/21/2 and the non-resonant isospin 3/23/2 channels. The numerical solution of the light-front tridimensional inhomogeneous integral equations for the Faddeev components of the decay amplitude is performed perturbatively. The loop-expansion converges fast, and the three-loop contribution can be neglected in respect to the two-loop results for the practical application. The dependence on the model parameters in respect to the input amplitude at the partonic level is exploited and the phase found in the experimental analysis, is fitted with an appropriate choice of the real weights of the isospin components of the partonic amplitude. The data suggests a small mixture of total isospin 5/25/2 to the dominant 3/23/2 one. The modulus of the unsymmetrized decay amplitude, which presents a deep valley and a following increase for KπK\pi masses above 1.51.5 GeV, is fairly reproduced. This suggests the assignment of the quantum numbers 0+0^+ to the isospin 1/2 K(1630)K^*(1630) resonance

    Periodic Anderson model with electron-phonon correlated conduction band

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    This paper reports dynamical mean field calculations for the periodic Anderson model in which the conduction band is coupled to phonons. Motivated in part by recent attention to the role of phonons in the γ\gamma-α\alpha transition in Ce, this model yields a rich and unexpected phase diagram which is of intrinsic interest. Specifically, above a critical value of the electron-phonon interaction, a first order transition with two coexisting phases develops in the temperature-hybridization plane, which terminates at a second order critical point. The coexisting phases display the familiar Kondo screened and local moment character, yet they also exhibit pronounced polaronic and bipolaronic properties, respectively.Comment: 4 pages, 6 figure

    Comparação da eficiência de fontes de fósforo na produção de arroz de terras altas.

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    O arroz de terras altas é importante componente dos sistemas de produção na região do Cerrado do Brasil. A deficiência de fósforo é um dos fatores limitantes na produção das culturas nessa região. Foi conduzido um ensaio em casa de vegetação com o objetivo de avaliar fontes de fósforo na produção de arroz de terras altas. Foram utilizadas seis fontes de P, i. e. Superfosfato simples (SFS), superfosfato simples policote (SFSP), superfosfato triplo (SFT), superfosfato triplo policote SFTP), fosfato monoamômico (FMA) e fosfato monoamômicopolicote (FMAP). As doses de P utilizados foram 50, 100, 200 e 400 mg kg-1 + testemunha. Houve resposta significativa e quadrática à aplicação de fontes de P na produção de grãos. Baseado na produção máxima, as fontes de P foram classificadas na ordem de fosfato monoamômicopolicote> superfosfato simples = fosfato monoamômico>superfosfatosimples policote > superfosfato triplo > superfosfato triplo policote

    Melhorando o diagnóstico diferencial entre síndromes mielodisplásicas e citopenias periféricas reativas por citometria de fluxo multiparamétrica: o papel dos precursores de células B

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    Immunophenotyping is a valuable ancillary technique for the differential diagnosis between myelodysplastic syndromes (MDS) with low bone marrow (BM) blast counts and a normal karyotype, and reactive peripheral (PB) cytopenias. Our aim was to search for the most important variables for this purpose. We also analyzed the age variation of BM B-cell precursors (BCP) and its differences in reactive and clonal cytopenias. Immunophenotypic analyzes were performed in BM of 54 patients with MDS (76% with BM blasts 55 years. % BM BCP could be calculated by the formula: (-7.97 × log age) + (4.24 × log % CD34 (+) cells) - (0.22 x nr. alterations CD34 (+) cells) + 0.577. Corrected R(2) = 0.467. Analysis of myelomonocytic precursors and CD34(+) cells was satisfactory for the differential diagnosis between reactive PB cytopenias and MDS. The most specific alterations were found in CD34(+) cells. Comparison of the values obtained with those of normal age-matched controls is recommended. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1975931809154663.Immunophenotyping is a valuable ancillary technique for the differential diagnosis between myelodysplastic syndromes (MDS) with low bone marrow (BM) blast counts and a normal karyotype, and reactive peripheral (PB) cytopenias. Our aim was to search for th104419FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO25924846sem informaçãoFAEPEX (proc 1208/11 Fundo de Pesquisa da Universidade de Campinas) e Fundação MDS (concessão de Jovem Investigador Tito Bastianello 2009). Konradin Metze e Irene Lorand-Metze têm uma bolsa de pesquisa do CNPq (proc. 307270 / 2010-6 e 302277 / 2009-9, re
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