226 research outputs found

    A Contingent Valuation Study Of Buriti (mauritia Flexuosa L.f.) In The Main Region Of Production In Brazil: Is Environmental Conservation A Collective Responsibility?

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The immature leaves of the buriti palm (Mauritia flexuosa) are widely harvested in the municipality of Barreirinhas, Maranhão, for the production of handicrafts, which are sold to locals and tourists. The increasing demand for these artisanal goods is stimulating the emergence of an informal market for immature buriti leaves, leading to an intensification of their extraction and resulting in negative effects on local buriti palm populations and the ecosystem. Thus, the objective of the present study was to assess the environmental value of the buriti palm tree based on the maximum willingness to pay (WTP) for its conservation, using the contingent valuation method. Among the respondents, 99.74% reported that the palm species should be protected and the majority of them (65.75%) agreed to pay for its conservation (annual WTP R$ 179.49 ± 222.05). Multivariate analysis revealed that the WTP was not influenced by the socio-economic profile of the respondents. The main reasons for non-WTP are related to dissatisfaction with the government and the belief that financial contributions would not solve problems of environmental damage. Overall, the evaluated population believes that environmental conservation is not an obligation of the government or that of the population, but is a collective responsibility. © 2016, Sociedade Botanica do Brasil. All rights reserved.304532539CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorMOE, Ministry of EducationCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    A ‘CRÍTICA DA CRÍTICA’ COMO ‘ROMANCE DE APRENDIZAGEM’: O CAPÍTULO PRESENÇA

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    O autor descreve a sua longa relação com a Presença, nomeadamente com a sua doutrina, teoria e crítica. Dividido em quatro partes – 1) criação poética, 2) natureza e finalidade da arte literária, 3) história e periodologia literárias, 4) defesa e ilustração da crítica –, o ensaio pretende demonstrar como o trabalho de reflexão de José Régio, Gaspar Simões e Casais Monteiro, grandes nomes desta geração, se alicerçam em cadeias de pensamento típicas da modernidade, i.e., aquele longo período entre o final do século XVIII e a segunda metade do século XX

    Avalanches in the Weakly Driven Frenkel-Kontorova Model

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    A damped chain of particles with harmonic nearest-neighbor interactions in a spatially periodic, piecewise harmonic potential (Frenkel-Kontorova model) is studied numerically. One end of the chain is pulled slowly which acts as a weak driving mechanism. The numerical study was performed in the limit of infinitely weak driving. The model exhibits avalanches starting at the pulled end of the chain. The dynamics of the avalanches and their size and strength distributions are studied in detail. The behavior depends on the value of the damping constant. For moderate values a erratic sequence of avalanches of all sizes occurs. The avalanche distributions are power-laws which is a key feature of self-organized criticality (SOC). It will be shown that the system selects a state where perturbations are just able to propagate through the whole system. For strong damping a regular behavior occurs where a sequence of states reappears periodically but shifted by an integer multiple of the period of the external potential. There is a broad transition regime between regular and irregular behavior, which is characterized by multistability between regular and irregular behavior. The avalanches are build up by sound waves and shock waves. Shock waves can turn their direction of propagation, or they can split into two pulses propagating in opposite directions leading to transient spatio-temporal chaos. PACS numbers: 05.70.Ln,05.50.+q,46.10.+zComment: 33 pages (RevTex), 15 Figures (available on request), appears in Phys. Rev.

    Detection of inconsistencies in geospatial data with geostatistics

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    Almost every researcher has come through observations that “drift” from the rest of the sample, suggesting some inconsistency. The aim of this paper is to propose a new inconsistent data detection method for continuous geospatial data based in Geostatistics, independently from the generative cause (measuring and execution errors and inherent variability data). The choice of Geostatistics is based in its ideal characteristics, as avoiding systematic errors, for example. The importance of a new inconsistent detection method proposal is in the fact that some existing methods used in geospatial data consider theoretical assumptions hardly attended. Equally, the choice of the data set is related to the importance of the LiDAR technology (Light Detection and Ranging) in the production of Digital Elevation Models (DEM). Thus, with the new methodology it was possible to detect and map discrepant data. Comparing it to a much utilized detections method, BoxPlot, the importance and functionality of the new method was verified, since the BoxPlot did not detect any data classified as discrepant. The proposed method pointed that, in average, 1,2% of the data of possible regionalized inferior outliers and, in average, 1,4% of possible regionalized superior outliers, in relation to the set of data used in the study

    Regional and large-scale patterns in Amazon forest structure and function are mediated by variations in soil physical and chemical properties

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    Forest structure and dynamics have been noted to vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. To test this hypothesis and assess the importance of edaphic properties in affect forest structure and dynamics, soil and plant samples were collected in a total of 59 different forest plots across the Amazon Basin. Samples were analysed for exchangeable cations, C, N, pH with various Pfractions also determined. Physical properties were also examined and an index of soil physical quality developed. Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions. Tree turnover rates emerged to be mostly influenced by soil physical properties whereas forest growth rates were mainly related to a measure of available soil phosphorus, although also dependent on rainfall amount and distribution. On the other hand, large scale variations in forest biomass could not be explained by any of the edaphic properties measured, nor by variation in climate. A new hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining forest disturbance levels, species composition and forest productivity on a Basin wide scale
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