A Bayesian analysis of inflationary primordial spectrum models using Planck data

The current available CMB data show an anomalously low value of the CMB temperature fluctuations at large angular scales (l < 40). This lack of power is not explained by the minimal LCDM model, and one of the possible mechanisms explored in the literature to address this problem is the presence of features in the primordial power spectrum (PPS) motivated by the early universe physics. In this paper, we analyse a set of cutoff inflationary PPS models using a Bayesian model comparison approach in light of the latest Cosmic Microwave Background (CMB) data from the Planck Collaboration. Our results show that the standard power-law parameterisation is preferred over all models considered in the analysis, which motivates the search for alternative explanations for the observed lack of power in the CMB anisotropy spectrum.Comment: 11 pages, 3 figure

Discriminação de especies de madeiras da floresta Amazônica de Paragominas, estado do Pará, Brasil, pela aplicação da espectroscopia no infravermelho próximo (NIRS)

0 trabalho teve coma objetivo discriminar 2 especies florestais tropicais, ocorrentes na Unidade de Manejo Florestal, do municipio de Paragominas, estado do Pará, Brasil, monitorada ha 25 anos pelo IMAZON. Foram selecionadas 41 e 46 arvores de Copaifera duckei Dwyer (copaiba) e de Cordia goeldiana Huber (freijó), respectivamente, e extraidas amostras do lenho do DAP, pelo metodo nao destrutivo. As amostras do lenho foram fixadas em suportes de madeira, sua seção transversal foi polida, acondicionadas (12% umidade, UR 65%, 20°C) e analisadas (1 cm de distancia, direção radial) no espectrômetro NIR MPA Bruker (módulo das sondas de fibra óptica 12800-4000 cm·1, resolução espectral 8 cm·1, dados médios de 32 leituras). Foram obtídos 2.161 espectros, tratados no software The Unscrambler® e simuladas as análises discriminantes com mínimos quadrados parciais (PLS-DA), compostas par 2 classes, (i) Copaifera duckei: valor esperado = 0, e (ii) Cordia goeldiana: valor esperado = 1, visando distinguir as 2 especies pela análise quimiométrica das suas madeiras. Os resultados mostraram uma clara separação, com base nos valores esperados, permitindo a discriminação das especies. A % do erro de classificação foi para a madeira de (i) copaiba [classe = 0, 0,6% [(validação cruzada), 0,8% (validação independente)] e (ii) freijó [classe =1, 0,7% (val. cruzada), 0,2% (val. independente)]. Concluise que a metodologia NIRS permite a discriminação de C. duckei e C. goeldiana, com base nas simulações PLS-DA, utilizando-se amostras nao destrutivas de madeira e, se constitui em eficiente ferramenta para a identificação de madeiras e controle da extração ilegal

Evaluating Brazilian mutual funds with stochastic frontiers

We evaluate the performance of 307 Brazilian stock mutual funds employing stochastic frontiers. We list the top ten actively managed funds and the bottom ten for the period April 2001-July 2003, and show that a fund's efficiency increases with management skill to beat the market. We also find that portfolios with low volatility tend to be more efficient. Yet we find no relationship between fund size and performance, though this might be blurred by a survivorship bias.

Quantum Confinement in Hydrogen Bond of DNA and RNA

The hydrogen bond is a fundamental ingredient to stabilize the DNA and RNA macromolecules. The main contribution of this work is to describe quantitatively this interaction as a consequence of the quantum confinement of the hydrogen. The results for the free and confined system are compared with experimental data. The formalism to compute the energy gap of the vibration motion used to identify the spectrum lines is the Variational Method allied to Supersymmetric Quantum Mechanics.Comment: 8 pages, 3 figures. To appear in The Proceedings of the 30th International Colloquium on Group Theoretical Methods in Physics (Group30), Ghent, Belgiu

Looking for a break in Spanish Inflation Data in the early eighties and assessing persistence

Using the Bai-Perron test, we look for a shift in the conditional mean of an AR representation of Spanish CPI inflation over the period: 1978-2006. It is clear that Spain, as most OECD economies, experienced an inflation slowdown in the early eithgties, which can be related to some policy measures undertook by the government coming out of the 1982 elections. It is shown, that when the break is accounted for, there are no signs of persistence in Spanish CPI inflation.inflation persistence; structural breaks; monetary policy