Loop Variables for a Class of Conical Spacetimes

Loop variables are used to describe the presence of topological defects in spacetime. In particular we study the dependence of the holonomy transformation on angular momentum and torsion for a multi-chiral cone. We also compute the holonomies for multiple moving crossed cosmic strings and two plane topological defects-crossed by a cosmic string.Comment: 17 pages, LATE

Vacuum polarization by topological defects in de Sitter spacetime

In this paper we investigate the vacuum polarization effects associated with a massive quantum scalar field in de Sitter spacetime in the presence of gravitational topological defects. Specifically we calculate the vacuum expectation value of the field square, $$. Because this investigation has been developed in a pure de Sitter space, here we are mainly interested on the effects induced by the presence of the defects.Comment: Talk presented at the 1st. Mediterranean Conference on Classical and Quantum Gravity (MCCQG

Household food diversity and nutritional status among adults in Brazil

<p>Abstract</p> <p>Background</p> <p>The aims of this study were to evaluate whether a diversity of healthy foods in a household would decrease the availability of unhealthy foods and to evaluate the association between a healthy dietary diversity score (DDS) and nutritional status among adults.</p> <p>Methods</p> <p>Data from the 2002-2003 Brazilian Household Budget Survey were used. This nationwide survey used a two-stage sampling technique: households were selected after selection of primary sample units (PSUs). Analyses were based on 3,393 PSUs, evaluating 659,816 records of food items purchased by 35,237 households. The DDS was based on the healthy food groups according to Brazilian food guidelines. Per capita acquisition of sugar, sweets, sugar-sweetened beverages and crackers, cookies and cakes (unhealthy food groups) in PSUs was also calculated. Individual weight and height were measured at household. Multivariate linear regression models estimated the association of underweight and overweight and obesity (excess weight) with the PSUs' DDS.</p> <p>Results</p> <p>Greater acquisition of unhealthy food groups was associated with higher DDS. A high PSU's DDS was negatively associated with underweight (β = -0.38; p-value = 0.04) and positively associated with excess weight (β = 0.98; p-value = 0.05) after adjustment for availability of unhealthy food groups and socioeconomic variables.</p> <p>Conclusions</p> <p>Our data indicate that there was no replacement of unhealthy food groups by healthy food groups, therefore a healthy diet message for obesity prevention should be combined with a message focused on eating less.</p

Ground State Energy of Massive Scalar Field Inside a Spherical Region in the Global Monopole Background

Using the zeta function regularization method we calculate the ground state energy of scalar massive field inside a spherical region in the space-time of a point-like global monopole. Two cases are investigated: (i) We calculate the Casimir energy inside a sphere of radius $R$ and make an analytical analysis about it. We observe that this energy may be positive or negative depending on metric coefficient $\alpha$ and non-conformal coupling $\xi$. In the limit $R\to\infty$ we found a zero result. (ii) In the second model we surround the monopole by additional sphere of radius $r_0<R$ and consider scalar field confined in the region between these two spheres. In the latter, the ground state energy presents an additional contribution due to boundary at $r_0$ which is divergent for small radius. Additional comments about renormalization are considered.Comment: 30 pages and 2 figures. LATEX fil

Parabolic dunes in north-eastern Brazil

In this work we present measurements of vegetation cover over parabolic dunes with different degree of activation along the north-eastern Brazilian coast. We are able to extend the local values of the vegetation cover density to the whole dune by correlating measurements with the gray-scale levels of a high resolution satellite image of the dune field. The empirical vegetation distribution is finally used to validate the results of a recent continuous model of dune motion coupling sand erosion and vegetation growth.Comment: 18 pages, 14 figures, aubmitted to Geomorpholog

Castanha-do-brasil: da floresta à mesa.

Origem. Potencialidades da castanha-do-brasil. Importância alimentar. Composição da castanha-do-brasil e de seu óleo. Padrão de qualidade da amêndoa. Outros usos da castanha-do-brasil. Receitas com castanha-do-brasil.bitstream/item/70901/1/.pd