Transmission coefficient and two-fold degenerate discrete spectrum of spin-1 bosons in a double-step potential

The scattering of spin-1 bosons in a nonminimal vector double-step potential is described in terms of eigenstates of the helicity operator and it is shown that the transmission coefficient is insensitive to the choice of the polarization of the incident beam. Poles of the transmission amplitude reveal the existence of a two-fold degenerate spectrum. The results are interpreted in terms of solutions of two coupled effective Schr\"{o}dinger equations for a finite square well with additional $\delta$-functions situated at the borders.Comment: arXiv admin note: substantial text overlap with arXiv:1203.119

An alternative theoretical approach to describe planetary systems through a Schrodinger-type diffusion equation

In the present work we show that planetary mean distances can be calculated with the help of a Schrodinger-type diffusion equation. The obtained results are shown to agree with the observed orbits of all the planets and of the asteroid belt in the solar system, with only three empty states. Furthermore, the equation solutions predict a fundamental orbit at 0.05 AU from solar-type stars, a result confirmed by recent discoveries. In contrast to other similar approaches previously presented in the literature, we take into account the flatness of the solar system, by considering the flat solutions of the Schrodinger-type equation. The model has just one input parameter, given by the mean distance of Mercury.Comment: 6 pages. Version accepted for publication in Chaos, Solitons & Fractal

Carotenoides em produtos de mandioca.

A estrutura altamente insaturada dos carotenoides, responsável pelas suas propriedades, torna-os susceptíveis à degradação durante o processamento. Em alimentos processados o teor dos carotenoides depende do tipo e das condições do processamento e da estocagem. A retenção de carotenoides totais ou do ?-caroteno em raízes de mandioca tem sido relatada para diferentes produtos. Em um dos estudos, a farinha de raspa seca ao forno e seca a sombra e a mandioca cozida apresentaram os maiores níveis de retenção (71,9; 59,2 e 55,7%, respectivamente) e o gari o menor (em torno de 34,1%). Elevada retenção também foi observada quando as raízes secas foram mantidas como lascas em vez de ser triturada como farinha. Avaliando a retenção dos produtos com o armazenamento, as perdas foram maiores durante as duas primeiras semanas e menores durante as duas semanas subsequentes. Em outro estudo a retenção do carotenoide total foi avaliada para quatro diferentes variedades, sendo observada maior retenção em mandioca cozida a 100 oC por 30 minutos (72 a 96%), para a mandioca chips e a farinha de mandioca a retenção foi menor (26 a 43% e 50 a 59%, respectivamente), provavelmente devido a alta temperatura utilizada

The Likelihood Ratio Test and Full Bayesian Significance Test under small sample sizes for contingency tables

Hypothesis testing in contingency tables is usually based on asymptotic results, thereby restricting its proper use to large samples. To study these tests in small samples, we consider the likelihood ratio test and define an accurate index, the P-value, for the celebrated hypotheses of homogeneity, independence, and Hardy-Weinberg equilibrium. The aim is to understand the use of the asymptotic results of the frequentist Likelihood Ratio Test and the Bayesian FBST -- Full Bayesian Significance Test -- under small-sample scenarios. The proposed exact P-value is used as a benchmark to understand the other indices. We perform analysis in different scenarios, considering different sample sizes and different table dimensions. The exact Fisher test for $2 \times 2$ tables that drastically reduces the sample space is also discussed. The main message of this paper is that all indices have very similar behavior, so the tests based on asymptotic results are very good to be used in any circumstance, even with small sample sizes

Optimization of hierarchical structures of information flow

The efficiency of a large hierarchical organisation is simulated on Barabasi-Albert networks, when each needed link leads to a loss of information. The optimum is found at a finite network size, corresponding to about five hierarchical layers, provided a cost for building the network is included in our optimization.Comment: Draft of 6 pages including all figure