712 research outputs found

    Long-term cognitive and behavioral therapies, combined with augmentative communication, are related to uncinate fasciculus integrity in autism

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    Recent evidence points to white-matter abnormalities as a key factor in autism physiopathology. Using Diffusion Tensor Imaging, we studied white-matter structural properties in a convenience sample of twenty-two subjects with low-functioning autism exposed to long-term augmentative and alternative communication, combined with sessions of cognitive and behavioral therapy. Uncinate fasciculus structural properties correlated significantly with therapy length and early onset, as well as to clinical outcome, independently from IQ, age or symptoms severity at therapy onset. Moreover, adherence to therapy was linked with better clinical outcome and uncinate fasciculus structural integrity. The results point to the capability of a long-term rehabilitation of subjects with low-functioning autism to produce white-matter structural modifications, which could thus play a role in the rehabilitative outcome

    Acoustic Nature of the Boson Peak in Vitreous Silica

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    New temperature dependent inelastic x-ray (IXS) and Raman (RS) scattering data are compared to each other and with existing inelastic neutron scattering data in vitreous silica (v-SiO_2), in the 300 - 1775 K region. The IXS data show collective propagating excitations up to Q=3.5 nm^-1. The temperature behaviour of the excitations at Q=1.6 nm^-1 matches that of the boson peak found in INS and RS. This supports the acoustic origin of the excess of vibrational states giving rise to the boson peak in this glass.Comment: 10 pages and 4 figure

    Modificações ambientais causadas pela implantação de Sistemas Agroflorestais em Áreas de Preservação Permanente: marco zero.

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    Sistemas agroflorestais (SAF) são alternativa para recuperação de Áreas de Preservação Permanente, mantendo-se a área produtiva do ponto de vista ecológico e agrícola. Está sendo feito um estudo, sob princípios da pesquisa-ação participativa, para acompanhamento e avaliação da evolução de SAF sucessionais na APA da Serra da Esperança e caracterização do efeito dos mesmos sobre o ecossistema, bem como sua inserção nos sistemas de produção locais. O objetivo deste trabalho é caracterizar as parcelas anteriormente à implantação dos SAF. Em cada parcela de estudo, em três propriedades de agricultores familiares de Inácio Martins/PR, Brasil, fez-se análises química e física do solo e levantamento florístico. Os solos apresentam baixa fertilidade natural e elevada acidez. O conteúdo de matéria orgânica é elevado e a estrutura apresenta excelentes condições. As parcelas experimentais tem semelhanças quanto à vegetação, entretanto há diferenças em função das práticas agrícolas associadas.Edição dos resumos do 7º Congresso Brasileiro de Agroecologia, 2013, Porto Alegre

    On the asymmetric zero-range in the rarefaction fan

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    We consider the one-dimensional asymmetric zero-range process starting from a step decreasing profile. In the hydrodynamic limit this initial condition leads to the rarefaction fan of the associated hydrodynamic equation. Under this initial condition and for totally asymmetric jumps, we show that the weighted sum of joint probabilities for second class particles sharing the same site is convergent and we compute its limit. For partially asymmetric jumps we derive the Law of Large Numbers for the position of a second class particle under the initial configuration in which all the positive sites are empty, all the negative sites are occupied with infinitely many first class particles and with a single second class particle at the origin. Moreover, we prove that among the infinite characteristics emanating from the position of the second class particle, this particle chooses randomly one of them. The randomness is given in terms of the weak solution of the hydrodynamic equation through some sort of renormalization function. By coupling the zero-range with the exclusion process we derive some limiting laws for more general initial conditions.Comment: 22 pages, to appear in Journal of Statistical Physic

    Academic spin-offs: counting beans or extracting value?

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    We argue that current approaches do not take into full account the process through which Universities create new spin-offs. Instead, we claim that the overall process through which these arrangements impact on spin-offs\u2019 performance can vary considerably and that this process should be interpreted in terms of University-level managerial practices in place for the creation and development of University spinoffs. Managerial practices are likely to play an important role in explaining the systematic difference in performance across spinoffs spun from different Universities. We rely on a longitudinal dataset comprising more than 800 Italian University spin-offs observed over the period 2000-2011 and additional data collection via questionnaires and semi-structured interviews to 68 Italian University TTOs. The scope is to juxtapose the above issues and to begin to uncover the black box of \u201cmanagerial practices \u2013 spinoff creation/performance\u201d in terms of antecedents and impact of a range of managerial activities not adequately covered by the extant literature. The results of this paper should therefore contribute to fill an important gap in the existing literature on university-industry knowledge transfer and academic entrepreneurship. Implications would inform policy makers and university managers about how to direct investments

    Advances in High-Energy-Resolution CdZnTe Linear Array Pixel Detectors with Fast and Low Noise Readout Electronics

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    Radiation detectors based on Cadmium Zinc Telluride (CZT) compounds are becoming popular solutions thanks to their high detection efficiency, room temperature operation, and to their reliability in compact detection systems for medical, astrophysical, or industrial applications. However, despite a huge effort to improve the technological process, CZT detectors’ full potential has not been completely exploited when both high spatial and energy resolution are required by the application, especially at low energies (<10 keV), limiting their application in energy-resolved photon counting (ERPC) systems. This gap can also be attributed to the lack of dedicated front-end electronics which can bring out the best in terms of detector spectroscopic performances. In this work, we present the latest results achieved in terms of energy resolution using SIRIO, a fast low-noise charge sensitive amplifier, and a linear-array pixel detector, based on boron oxide encapsulated vertical Bridgman-grown B-VB CZT crystals. The detector features a 0.25-mm pitch, a 1-mm thickness and is operated at a −700-V bias voltage. An equivalent noise charge of 39.2 el. r.m.s. (corresponding to 412 eV FWHM) was measured on the test pulser at 32 ns peaking time, leading to a raw resolution of 1.3% (782 eV FWHM) on the 59 keV line at room temperature (+20 °C) using an uncollimated 241Am, largely improving the current state of the art for CZT-based detection systems at such short peaking times, and achieving an optimum resolution of 0.97% (576 eV FWHM) at 1 µs peaking time. The measured energy resolution at the 122 keV line and with 1 µs peaking time of a 57Co raw uncollimated spectrum is 0.96% (1.17 keV). These activities are in the framework of an Italian collaboration on the development of energy-resolved X-ray scanners for material recycling, medical applications, and non-destructive testing in the food industry
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