International Portfolio Diversification: Short-Term Financial Assets and Gold

Using a continuous-time finance-theoretic framework, this paper presents the optimal portfolio rule of an international investor who consumes N national composite goods and who holds N domestic-currency-denominated assets with known nominal interest rates in an environment where prices of goods, assets and exchange rates follow geometric Brownian motion. It is shown that the currency portfolio rule described in Macedo (1982a) is applicable to the case where there are N assets with a known price and one asset, gold, with a random rice in terms of the numeraire. Under these assumptions, it is found that the optimal portfolio of an investor consuming goods from all major industrialized countries (according to their weight in total trade) would be dominated in March 1981 by long positions in U.S. dollars (25%), yen (17%), D. marks (16%), French francs (15%) and pounds sterling (10%). An investor consuming only U.S. goods, by contrast, would hold 96% of his optimal portfolio in U.S. dollars. Because of the covariance of exchange rates and gold, the exclusion of the latter generates substantial reshuffling. The analysis of the evolution of portfolios over time shows that shares changed dramatically at the beginning of the period and did not begin to approach their March 1981 values until the end of 1975. In the case of the yen and the pound there were oscillations throughout the period. With respect to the dollar share in the optimal portfolio of the U.S. and international investor, it is found that, in the period between late 1974 and mid-1976, a period in which the dollar is considered to have been "strong", a large decline in its optimal share took place.

Operações de pós processamento no levantamento aéreo expedito.

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Gravitational wave recoil in Robinson-Trautman spacetimes

We consider the gravitational recoil due to non-reflection-symmetric gravitational wave emission in the context of axisymmetric Robinson-Trautman spacetimes. We show that regular initial data evolve generically into a final configuration corresponding to a Schwarzschild black-hole moving with constant speed. For the case of (reflection-)symmetric initial configurations, the mass of the remnant black-hole and the total energy radiated away are completely determined by the initial data, allowing us to obtain analytical expressions for some recent numerical results that have been appeared in the literature. Moreover, by using the Galerkin spectral method to analyze the non-linear regime of the Robinson-Trautman equations, we show that the recoil velocity can be estimated with good accuracy from some asymmetry measures (namely the first odd moments) of the initial data. The extension for the non-axisymmetric case and the implications of our results for realistic situations involving head-on collision of two black holes are also discussed.Comment: 9 pages, 6 figures, final version to appear in PR

Black-hole horizons as probes of black-hole dynamics I: post-merger recoil in head-on collisions

The understanding of strong-field dynamics near black-hole horizons is a long-standing and challenging prob- lem in general relativity. Recent advances in numerical relativity and in the geometric characterization of black- hole horizons open new avenues into the problem. In this first paper in a series of two, we focus on the analysis of the recoil occurring in the merger of binary black holes, extending the analysis initiated in [1] with Robinson- Trautman spacetimes. More specifically, we probe spacetime dynamics through the correlation of quantities defined at the black-hole horizon and at null infinity. The geometry of these hypersurfaces responds to bulk gravitational fields acting as test screens in a scattering perspective of spacetime dynamics. Within a 3 + 1 approach we build an effective-curvature vector from the intrinsic geometry of dynamical-horizon sections and correlate its evolution with the flux of Bondi linear momentum at large distances. We employ this setup to study numerically the head-on collision of nonspinning black holes and demonstrate its validity to track the qualita- tive aspects of recoil dynamics at infinity. We also make contact with the suggestion that the antikick can be described in terms of a "slowness parameter" and how this can be computed from the local properties of the horizon. In a companion paper [2] we will further elaborate on the geometric aspects of this approach and on its relation with other approaches to characterize dynamical properties of black-hole horizons.Comment: final version published on PR

Capacitação de técnicos e assentados dos assentamentos do Estado de Goiás.

Desde o ano 2004 a Embrapa Arroz e Feijão, desenvolve várias ações junto aos assentamentos da reforma agrária nos municípios de Caiapônia e Piranhas de Goiás. Esse trabalho foi intensificado a partir de 2006 com o convênio entre a Embrapa Arroz e Feijão, o Instituto Nacional de Colonização e Reforma Agrária (Incra-GO) e a Fundação de Apoio á Pesquisa e ao Desenvolvimento (Faped). A iniciativa buscou incrementar a produção de alimentos, a geração de renda e a conservação de solos nas unidades produtivas dos assentamentos. O trabalho também valorizou o espaço rural de cada comunidade como um ambiente rico em experiência de vida e intimamente ligado á preservação dos recursos naturais da região. Em todas as ações e intervenções promovidas pelo convênio, houve a participação efetiva dos prestadores de assistência técnica aos assentados e dos próprios assentados, sempre no sentido de respeitar os conhecimentos tradicionais, melhor o bem-estar e reduzir a dependência de insumos externos.bitstream/CNPAF/26717/1/doc_211.pd

Manejo de viroses associadas à mosca-branca, Bemísia tabaci.

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Incidência de begomovírus de tomateiro em amostras de soja coletadas durante o período do vazio fitossanitário em 2013/2014.

O objetivo deste trabalho foi avaliar a incidência de Tomato severe rugose virus (ToSRV), o principal begomovírus de tomateiro, em amostras de soja coletadas durante o período de vazio fitossanitário do tomateiro (novembro a janeiro).Resumo 15