Similarity of ground-dwelling anuran (Amphibia) composition among different vegetation physiognomies in a Mesophytic Semideciduous Forest from southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fish, Passa Cinco stream, Corumbatai River basin, state of São Paulo, Brazil.

The fishes of the present study were collected in Passa Cinco stream, a main river of Corumbatai river basin, Tiete drainage. Five sites were selected in that stream, downstream from headwater to its mouth, and six samplings were performed using the following fishery equipment: a sieve, electric fishery equipment, gill nets and fish-traps. 5082 individuals, 62 species, 18 families and 6 orders were captured. The orders Characiformes and Siluriformes were the most representative and the families Characidae and Loricariidae presented the largest in number of species.

Fish, Mogi Guacu reservoir and four oxbow lakes, state of São Paulo, Brazil.

The Mogi Guacu River is one of the largest rivers in state of São Paulo, belonging to Parana hydrographic system. A study about fish composition in the Mogi Guacu reservoir and four oxbow lakes downstream the reservoir is showed. A total of 2,367 individuals from six orders, 17 families, and 46 species were collected during August 2005 to July 2006, using gillnets, traps and hand nets. In the reservoir were found 31 species and in the oxbow lakes 24, in which Curimatidae and Characidae were the most abundant families, respectively.

Seasonal variation in body size of tropical anuran amphibians.

Most anurans are considered short lived reproducing only once, with adult size being an important factor contributing to mating success. We sampled anurans with 30 pitfall traps in three forest patches of the northwestern São Paulo State, Brazil, throughout one year. Our objective was to analyze the variation in anuran body size between the dry and rainy season. Our hypothesis is that anurans registered during the rainy season will be larger than conspecifics registered during dry season, since there is a selective advantage in having a larger body size during reproduction activity. The most abundant species registered in the patches were Eupemphix nattereri, Physalaemus cuvieri and Leptodactylus podicipinus. Males and females of E. nattereri and P. cuvieri recorded in the rainy season were larger than of those captured in the dry one. In contrast, males of L. podicipinus were larger in the dry season than in the rainy season. Besides, the operational sex ratio (OSR) in the breeding season was biased towards males in these three species with, respectively, 4.66, 3.2 and 1.87 males per female. Our results suggest that probably body size variation between different seasons is a consequence of individuals' turnover between rainy seasons. Lower individuals captured in the dry season, would be reproductively active adults in the next breeding season.

Coordinate and time-dependent diffusion dynamics in protein folding

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Statistics and kinetics of single-molecule electron transfer dynamics in complex environments: A simulation model study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An improved bait method for collecting Hymenoptera, especially social wasps (Vespidae: Polistinae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dynamics of bright matter-wave solitons in a Bose-Einstein condensate with inhomogeneous scattering length

We investigate dynamical effects of a bright soliton in Bose-Einstein condensed (BEC) systems with local and smooth space variations of the two-body atomic scattering length. It includes a discussion about the possible observation of a new type of standing nonlinear atomic matter wave in cigar-type traps. A rich dynamics is observed in the interaction between the soliton and an inhomogeneity. By considering an analytical time-dependent variational approach and also full numerical simulation of one-dimensional and three-dimensional Gross-Pitaevskii equations, we study processes such as trapping, reflection and transmission of the bright matter soliton due to the impurity. We also derive conditions for the collapse of the bright solitary wave, considering a quasi-one-dimensional BEC with attractive local inhomogeneity.

Mean-field model for the interference of matter-waves from a three-dimensional optical trap

Using the mean-field time-dependent Gross-Pitaevskii equation we study the formation of a repulsive Bose-Einstein condensate on a combined optical and harmonic traps in two and three dimensions and subsequent generation of the interference pattern upon the removal of the combined traps as in the experiment by, Greiner et al. [Nature (London 415 (2002) 39]. For optical traps of moderate strength, interference pattern of 27 (9) prominent bright spots is found to be formed in three. (two) dimensions on a cubic (square) lattice in agreement with experiment. Similar interference pattern can also be formed upon removal of the optical lattice trap only. The pattern so formed can oscillate for a long time in the harmonic trap which can be observed experimentally. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Formation of soliton trains in Bose-Einstein condensates as a nonlinear Fresnel diffraction of matter waves

The problem of generation of atomic soliton trains in elongated Bose-Einstein condensates is considered in framework of Whitham theory of modulations of nonlinear waves. Complete analytical solution is presented for the case when the initial density distribution has sharp enough boundaries. In this case the process of soliton train formation can be viewed as a nonlinear Fresnel diffraction of matter waves. Theoretical predictions are compared with results of numerical simulations of one- and three-dimensional Gross-Pitaevskii equation and with experimental data on formation of Bose-Einstein bright solitons in cigar-shaped traps. (C) 2003 Elsevier B.V. All rights reserved.

Collapse of attractive Bose-Einstein condensed vortex states in a cylindrical trap

The quantized vortex states of a weakly interacting Bose-Einstein condensate of atoms with attractive interatomic interaction in an axially symmetric harmonic oscillator trap are investigated using the numerical solution of the time-dependent Gross-Pitaevskii equation obtained by the semi-implicit Crank-Nicholson method. The collapse of the condensate is studied in the presence of deformed traps with the larger frequency along either the radial or the axial direction. The critical number of atoms for collapse is calculated as a function of the vortex quantum number L. The critical number increases with increasing angular momentum L of the cortex state but tends to saturate for large L.

Fortran programs for the time-dependent Gross-Pitaevskii equation in a fully anisotropic trap

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Gap solitons in a dipolar Bose-Einstein condensate on a three-dimensional optical lattice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stochastic variational approach applied to 2, 3 and 4 alpha particles

A stochastic variational method is applied to calculate the binding energies and root-mean-square radii of 2, 3 and 4 alpha particles using an S-wave Ali-Bodmer potential. The results agree with other calculations. We discuss the application of the present method to study the universality in weakly-bound three and four-body systems in the context of ultracold atomic traps.

C programs for solving the time-dependent Gross-Pitaevskii equation in a fully anisotropic trap

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)