Quantum propagator for some classes of three-dimensional three-body systems

In this work we solve exactly a class of three-body propagators for the most general quadratic interactions in the coordinates, for arbitrary masses and couplings. This is done both for the constant as the time-dependent couplings and masses, by using the Feynman path integral formalism. Finally, the energy spectrum and the eigenfunctions are recovered from the propagators. © 2005 Elsevier Inc. All rights reserved.

Análise da incerteza na representação de classes de cobertura do solo urbano resultantes da aplicação de uma rede neural artificial

The great diversity of materials that characterizes the urban environment determines a structure of mixed classes in a classification of multiespectral images. In that sense, it is important to define an appropriate classification system using a non parametric classifier, that allows incorporating non spectral (such as texture) data to the process. They also allow analyzing the uncertainty associated to each class from the output alues of the network calculated in relation to each class. Considering these properties, an experiment was carried out. This experiment consisted in the application of an Artificial Neural Network aiming at the classification of the urban land cover of Presidente Prudente and the analysis of the uncertainty in the representation of the mapped thematic classes. The results showed that it is possible to discriminate the variations in the urban land cover through the application of an Artificial Neural Network. It was also possible to visualize the spatial variation of the uncertainty in the attribution of classes of urban land cover from the generated representations. The class characterized by a defined pattern as intermediary related to the impermeability of the urban soil presented larger ambiguity degree and, therefore, larger mixture.

Destroying horseshoes via heterodimensional cycles: Generating bifurcations inside homoclinic classes

In this paper, we propose a model for the destruction of three-dimensional horseshoes via heterodimensional cycles. This model yields some new dynamical features. Among other things, it provides examples of homoclinic classes properly contained in other classes and it is a model of a new sort of heteroclinic bifurcations we call generating. © 2008 Cambridge University Press.

Using tree population size structures to assess the impacts of cattle grazing and eucalypts plantations in subtropical South America

To evaluate the effects of distinct management of the matrix in which forest fragments are found upon plant populations thriving in forest remnants in south Brazil, we assessed the conservation status of populations of four woody species (Campomanesia rhombea, Diospyros incontans, Myrciaria cuspidata and Sebastiania commersoniana) through analyses of size structure. Analyzes were carried out at two scales. At a local scale, we consider populations in fragments surrounded by pastures or eucalypts forest plantations, and at a regional scale we also consider larger forest tracts taken as reference areas (Rio Grande do Sul Forest Inventory databank). Population size structures were summarized using the symmetry of height distributions. Small individual size classes prevailed at the local scale in fragments surrounded by eucalypts plantations, whereas in areas exposed to cattle ranching, populations of the same species consistently lack small individuals. At the regional scale, populations in fragments surrounded by pastures presented greater skewness (prevalence of small plants) than populations in reference areas, while populations surrounded by eucalypts plantations presented intermediate skewness. These results reinforce the notion that plantations have a higher conservation value for forest ecosystems than other commercial land uses, like cattle ranching. © 2010 Springer Science+Business Media B.V.

β-conglycinin combined with fenofibrate or rosuvastatin have exerted distinct hypocholesterolemic effects in rats

Background: There is increasing interest in non-pharmacological control of cholesterol and triglyceride levels in the plasma and diet-drug association represent an important area of studies. The objective of this study was to observe the hypocholesterolemic effect of soybean β-conglycinin (7S protein) alone and combined with fenofibrate and rosuvastatin, two hypolipidemic drugs. Methods. The protein and drugs were administered orally once a day to rats and the effects were evaluated after 28 days. Wistar rats were divided into six groups (n = 9): hypercholesterolemic diet (HC), HC+7S protein (300 mg.kg-1 day-1) (HC-7S), HC+fenofibrate (30 mg.kg-1 day-1)(HC-FF), HC+rosuvastatin (10 mg.kg-1 day-1)(HC-RO), HC+7S+fenofibrate (HC-7S-FF) and HC+7S+rosuvastatin (HC-7S-RO). Results: Animals in HC-7S, HC-FF and HC-RO exhibited reductions of 22.9, 35.8 and 18.8% in total plasma cholesterol, respectively. In HC-7S-FF, animals did not show significant alteration of the level in HC+FF while the group HC-7S-RO showed a negative effect in comparison with groups taking only protein (HC-7S) or drug (HC-RO). The administration of the protein, fenofibrate and rosuvastatin alone caused increases in the plasma HDL-C of the animals, while the protein-drug combinations led to an increase compared to HC-FF and HC-RO. The plasma concentration of triacylgycerides was significantly reduced in the groups without association, while HC-7S-FF showed no alteration and HC-7S-RO a little reduction. Conclusion: The results of our study indicate that conglycinin has effects comparable to fenofibrate and rosuvastatin on the control of plasma cholesterol, HDL-C and triacylglycerides, when given to hypercholesterolemic rats, and suggests that the association of this protein with rosuvastatin alters the action of drug in the homeostasis of cholesterol. © 2012 Ferreira et al; licensee BioMed Central Ltd.

Lê cycles and Milnor classes

The purpose of this work is to establish a link between the theory of Chern classes for singular varieties and the geometry of the varieties in question. Namely, we show that if Z is a hypersurface in a compact complex manifold, defined by the complex analytic space of zeroes of a reduced non-zero holomorphic section of a very ample line bundle, then its Milnor classes, regarded as elements in the Chow group of Z, determine the global Lê cycles of Z; and vice versa: The Lê cycles determine the Milnor classes. Morally this implies, among other things, that the Milnor classes determine the topology of the local Milnor fibres at each point of Z, and the geometry of the local Milnor fibres determines the corresponding Milnor classes. © 2013 Springer-Verlag Berlin Heidelberg.

Reassessing social policies in Latin America: growth, middle classes and social rights

Includes bibliography