1,592 research outputs found

    Recomendações para o cultivo da goiabeira no Rio Grande do Sul.

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    bitstream/item/47510/1/circular-110.pd

    Recomendações para produção de videiras americanas e híbridas para processamento na região de Pelotas.

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    bitstream/item/30918/1/circular-77.pd

    Propagação vegetativa de frutíferas de caroço por estacas herbáceas em escala comercial.

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    bitstream/item/106219/1/Boletim-195-web.pd

    The blockchain role in ethical data acquisition and provisioning

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    The collection of personal data through mobile applications and IoT devices represents the core business of many corporations. From one hand, users are losing control about the property of their data and rarely are conscious about what they are sharing with whom; from the other hand, laws like the European General Data Protection Regulation try to bring data control and ownership back to users. In this paper we discuss the possible impact of the blockchain technology in building independent and resilient data management systems able to ensure data ownership and traceability. The use of this technology could play a major role in creating a transparent global market of aggregated personal data where voluntary acquisition is subject to clear rules and some forms of incentives, making not only the process ethical but also encouraging the sharing of high quality sensitive data

    Optimal constants for a nonlocal approximation of sobolev norms and total variation

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    We consider the family of nonlocal and nonconvex functionals proposed and investigated by J. Bourgain, H. Brezis and H.-M. Nguyen in a series of papers of the last decade. It was known that this family of functionals Gamma-converges to a suitable multiple of the Sobolev norm or the total variation, depending on the summability exponent, but the exact constants and the structure of recovery families were still unknown, even in dimension 1. We prove a Gamma-convergence result with explicit values of the constants in any space dimension. We also show the existence of recovery families consisting of smooth functions with compact support. The key point is reducing the problem first to dimension 1, and then to a finite combinatorial rearrangement inequality

    Replica Field Theory for Deterministic Models (II): A Non-Random Spin Glass with Glassy Behavior

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    We introduce and study a model which admits a complex landscape without containing quenched disorder. Continuing our previous investigation we introduce a disordered model which allows us to reconstruct all the main features of the original phase diagram, including a low TT spin glass phase and a complex dynamical behavior.Comment: 35 pages with uu figures, Roma 102

    Mycorrhizal activity and diversity in a long-term organic Mediterranean agroecosystem

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    In organic agriculture, soil fertility and productivity rely on biological processes carried out by soil microbes, which represent the key elements of agroecosystem functioning. Arbuscular mycorrhizal fungi (AMF), fundamental microorganisms for soil fertility, plant nutrition and health, may play an important role in organic agriculture by compensating for the reduced use of fertilizers and pesticides. Though, AMF activity and diversity following conversion from conventional to organic farming are poorly investigated. Here we studied AMF abundance, diversity and activity in short- and long-term organically and conventionally managed Mediterranean arable agroecosystems. Our results show that both AMF population activity, as assessed by the mycorrhizal inoculum potential (MIP) assay, the percentage of colonized root length of the field crop (maize) and glomalin-related soil protein (GRSP) content were higher in organically managed fields and increased with time since transition to organic farming. Here, we showed an increase of GRSP content in arable organic systems and a strong correlation with soil MIP values. The analysis of AMF spores showed differences among communities of the three microagroecosystems in terms of species richness and composition as suggested by a multivariate analysis. All our data indicate that AMF respond positively to the transition to organic farming by a progressive enhancement of their activity that seems independent from the species richness of the AMF communities. Our study contributes to the understanding of the effects of agricultural managements on AMF, which represent a promising tool for the implementation of sustainable agriculture

    Finite-Connectivity Spin-Glass Phase Diagrams and Low Density Parity Check Codes

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    We obtain phase diagrams of regular and irregular finite connectivity spin-glasses. Contact is firstly established between properties of the phase diagram and the performances of low density parity check codes (LDPC) within the Replica Symmetric (RS) ansatz. We then study the location of the dynamical and critical transition of these systems within the one step Replica Symmetry Breaking theory (RSB), extending similar calculations that have been performed in the past for the Bethe spin-glass problem. We observe that, away from the Nishimori line, in the low temperature region, the location of the dynamical transition line does change within the RSB theory, in comparison with the (RS) case. For LDPC decoding over the binary erasure channel we find, at zero temperature and rate R=1/4 an RS critical transition point located at p_c = 0.67 while the critical RSB transition point is located at p_c = 0.7450, to be compared with the corresponding Shannon bound 1-R. For the binary symmetric channel (BSC) we show that the low temperature reentrant behavior of the dynamical transition line, observed within the RS ansatz, changes within the RSB theory; the location of the dynamical transition point occurring at higher values of the channel noise. Possible practical implications to improve the performances of the state-of-the-art error correcting codes are discussed.Comment: 21 pages, 15 figure
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