1,167 research outputs found

    PODA VERDE NA PRODUÇÃO E QUALIDADE DE UVA CV. RUBI (Vitis vinifera L.) NO NORTE DO ESPÍRITO SANTO

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    A produção de uvas vem ganhando, cada vez mais, destaque na economia do Brasil. O nordeste brasileiro é responsável pela produção das melhores uvas finas de mesa do Brasil, inclusive com qualidade que possibilita a exportação para vários países do mundo. Portanto, não é uma novidade o cultivo da uva em regiões quentes, o que não existia ainda, eram pesquisas com a uva no norte capixaba. A videira Vitis Vinifera L. cv. Rubi é uma das uvas de mesa mais importantes no Brasil. Para o seu cultivo, temos o sistema de poda verde (desponte) que é realizada em videiras com o objetivo de equilibrar o desenvolvimento vegetativo e a produção, visando à alta produtividade e à melhoria da qualidade da uva. Devido à falta de parâmetros científicos em relação à uva cv. Rubi no estado do Espírito Santo, o experimento teve como objetivo avaliar o número ideal de folhas que deve ser deixado nos ramos para se obter melhor produtividade e qualidade de frutos para as condições encontradas na região. O experimento foi conduzido no Sítio São Lázaro, bairro Córrego do Ribeirão, município de São Mateus ES, no período de fevereiro de 2011 a agosto de 2012, com a videira cv. Rubi. O delineamento foi em blocos casualizados, com 5 tratamentos e 4 repetições, e as médias comparadas pelo teste de Tukey ao nível de 5% de probabilidade. Os tratamentos foram compostos de 15,20, 25, 30 folhas seguidas e 22 folhas alternadas, sendo que os ramos foram cortados a partir da última folha contada de cada tratamento. Foram avaliados 5 cachos por repetição, sendo que foi estabelecido um total de 50 bagas por cacho para uniformizá-los. As variáveis avaliadas nos tratamentos foram as características física e química dos cachos e da uva, características fisiológicas da folha e a média de crescimentos dos ramos. Depois de colhidos, os cachos e as folhas foram levados ao laboratório de Fitotecnia do Centro Universitário Norte do Espírito Santo - CEUNES para realização das análises. Após os resultados das análises, verificou-se que o número de folhas deixados através da poda verde (desponte) não influenciou a massa média dos cachos, porém, influenciou no número médio de cachos produzidos por planta, e no comprimento dos cachos, ou seja, influenciando diretamente na produtividade. O diâmetro da baga, o número de sementes por baga e a porcentagem não foram influenciados pelos tratamentos (número de folhas). As características químicas das bagas não foram influenciadas pelos tratamentos. O tratamento com 15 folhas proporcionou aumento na área foliar e também no teor de clorofila a, clorofila b e clorofila total. O crescimento dos ramos não foi influenciado pelos tratamentos, porém, os ramos que apresentavam cachos mostraram maior crescimento e consequentemente maior formação de novas folhas. Com isso, conclui-se que o desponte não influencia na qualidade dos frutos, mas sim na produtividade da videira cv. Rubi, em que 25 folhas obteve a maior produtividade comparado com os demais tratamentos

    Study of quasi-1D SnO2 nanowires

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    The descriptions of SnO2 nanowires growth procedures are getting more and more frequent in the current literature. However, studies on the growth mechanisms are still lacking. In particular, no investigation has been reported on the growth process when the growth mechanisms are not based, as in the case of whiskers, on vapour-liquid-solid (VLS) transitions. In this paper, a new procedure is reported by the authors for growing SnO2 nanowires, based on the presence of liquid-tin droplets on the substrate. The Sn vapour pressure developed by these droplets, which find themselves very close to the growing tip of the wire, gives rise to a sufficiently high supersaturation to enable the fast growth rate usually observed. The principal features and results of this new procedure, as well as possible growth mechanisms, are also discussed

    A determination of the strange quark mass for unquenched clover fermions using the AWI

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    Using the O(a) Symanzik improved action an estimate is given for the strange quark mass for unquenched (nf=2) QCD. The determination is via the axial Ward identity (AWI) and includes a non-perturbative evaluation of the renormalisation constant. Numerical results have been obtained at several lattice spacings, enabling the continuum limit to be taken. Results indicate a value for the strange quark mass (in the MSbar-scheme at a scale of 2GeV) in the range 100 - 130MeV.Comment: 6 pages, contribution to Lattice2005(Hadron spectrum and quark masses), uses PoS.cl

    An Experimental Validation of Phase-Based Motion Magnification for Structures with Developing Cracks and Time-Varying Configurations

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    In this study, Computer Vision and Phase-Based Motion Magnification (PBMM) are validated for continuous Structural Health Monitoring (SHM) purposes. The aim is to identify the exact instant of occurrence for damage or abrupt structural changes from video-extracted, very low amplitude (barely visible) vibrations. The study presents three experimental datasets: a box beam with multiple saw cuts of different lengths and angles, a beam with a full rectangular cross section and a mass added at the tip, and the spar of a prototype High-Aspect-Ratio wing. Both mode-shape- and frequency-based approaches are considered, showing the potential to identify the severity and position of the damage as well A high-definition, high-speed camera and a low-cost commercial alternative have been successfully utilised for these video acquisitions. Finally, the technique is also preliminarily tested for outdoor applications with smartphone cameras

    Reduced T-cell repertoire restrictions in abatacept-treated rheumatoid arthritis patients.

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    BACKGROUND: CD28(neg) T cells, which display functional characteristic of oligoclonally expanded cytotoxic memory T lymphocytes, are believed to be pathologically relevant in rheumatoid arthritis manifestation. The CD28 co-stimulation blockade by abatacept can prevent the generation of CD28(neg) T-cell populations in these patients. METHODS: Samples were obtained before and after 12 months of abatacept therapy. T-cell phenotype and T-cell receptor diversity were evaluated by flow cytometry and complementarity-determining region-3 spectratyping, respectively, while telomerase reverse-transcriptase gene level was measured by real-time PCR. RESULTS: Abatacept induces a decrease of the percentage and number of CD4(+)CD28(neg) T cells and a reduction of T-cell repertoire restrictions; these features are directly correlated. Thymic output and telomerase activity are not modified by the therapy. CONCLUSIONS: Abatacept-induced decrease of peripheral T-cell repertoire restrictions can due to a reduced generation of senescent, chronically stimulated CD4(+)CD28(neg) T cells

    The operator product expansion on the lattice

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    We investigate the Operator Product Expansion (OPE) on the lattice by directly measuring the product (where J is the vector current) and comparing it with the expectation values of bilinear operators. This will determine the Wilson coefficients in the OPE from lattice data, and so give an alternative to the conventional methods of renormalising lattice structure function calculations. It could also give us access to higher twist quantities such as the longitudinal structure function F_L = F_2 - 2 x F_1. We use overlap fermions because of their improved chiral properties, which reduces the number of possible operator mixing coefficients.Comment: 7 pages, 4 postscript figures. Contribution to Lattice 2007, Regensbur

    Nucleon structure in terms of OPE with non-perturbative Wilson coefficients

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    Lattice calculations could boost our understanding of Deep Inelastic Scattering by evaluating moments of the Nucleon Structure Functions. To this end we study the product of electromagnetic currents between quark states. The Operator Product Expansion (OPE) decomposes it into matrix elements of local operators (depending on the quark momenta) and Wilson coefficients (as functions of the larger photon momenta). For consistency with the matrix elements, we evaluate a set of Wilson coefficients non-perturbatively, based on propagators for numerous momentum sources, on a 24^3 x 48 lattice. The use of overlap quarks suppresses unwanted operator mixing and lattice artifacts. Results for the leading Wilson coefficients are extracted by means of Singular Value Decomposition.Comment: 7 pages, 3 figures, contribution to the XXVI International Symposium on Lattice Field Theory, July 14-19 Williamsburg, Virginia, US

    Use of adipose derived stem cells in Treacher Collins syndrome

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    Objective: Treacher Collins syndrome (TCS) is a rare congenital disorder of craniofacial development. TCS occurs with an incidence of 1:50,000, and more than 60% of TCS cases have no previous family history and arise as the result of de novo mutations. The high rate of de novo mutations, together with the extreme variability in the degree to which individuals can be affected, makes the provision of genetic counseling extremely complicated. Consequently, every case of TCS is unique and needs to be assessed individually. Patients with TCS frequently undergo multiple reconstructive surgeries from birth through adulthood, which rarely are fully corrective in the long-term. The nascent field of regenerative medicine offers the promise to improve some of these treatments. In particular, structural fat grafting (SFG) seems to be a good strategy not only to restore the normal volume and contour of the face, but also to provide a source of adipose-derived stem cells (ADSCs) with a multilineage differentiation potential. In this work, we present genetical analyses of ADSC affected by TCS. Materials and methods: ADSCs from were analyzed for their stemness properties and shared many characteristics with those of a healthy subject. Screening of the genome of the TCS patient using array-Comparative Genomic Hybridization allowed us to identify some chromosomal imbalances that are probably associated with TCS. Results: We found that some alterations, involving the TIMELESS gene, were usually associated with embryonic stem cells. Conclusions: With the aim to improve the final results, we need to consider combining knowledge of genetic alterations and expression profiles as a fundamental step before starting with surgical procedures
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