Bolivianos Em São Paulo: Entre O Sonho E A Realidade

This paper aims to analyze the settlement of Bolivian immigrants in São Paulo, focusing on the difficulties they face in their trajectories in the city, as well as on their strategies for economic mobility and social recognition, which are developed in an adverse environment characterized by lack of proper documentation and by racial and social discrimination. © 2006 Instituto de Estudos Avançados da Universidade de São Paulo.2057157170Harvey, D., (1992) Condição Pós-moderna, , São Paulo: LoyolaFrugoli Jr., H., (1995) São Paulo: Espaços Públicos E Integração Social, , São Paulo: Marco ZeroLe Goff, J., (1994) O Imaginário Medieval, , Lisboa: EstampaMagnani, J.G.C., Torres, L.deL., (1996) Na Metrópole, , (Org.) São Paulo: EduspPóvoa Neto, H., A criminalização das migrações na nova ordem internacional (2005) Cruzando Fronteiras Disciplinares. Um Panorama Dos Estudos Migratórios, pp. 297-309. , In: PÓVOA NETO, H.FERREIRA, A. P. (Org.) Rio de Janeiro: RevanSales, T., (1999) Brasileiros Longe De Casa, , São Paulo: CortezSayad, A., (1998) A Imigração Ou Os Paradoxos Da Alteridade, , São Paulo: EduspSayad, A., O retorno: Elemento constitutivo da condição do imigrante (2000), Travessia - Revista do Migrante, São Paulo, Centro de Estudos Migratórios, n.1, especial, janeiroSilva, S., A Costurando sonhos. Trajetória de um grupo de imigrantes bolivianos em São Paulo (1997), São Paulo: PaulinasSilva, S., Virgem/Mãe/Terra. Festas e tradições bolivianas na metrópole (2003), São Paulo: Hucitec, FapespSilva, S., Bolivianos. A presença da cultura andina (2005), São Paulo: LazuliSilva, S., A praça é nossa. Faces do preconceito num bairro paulistano (2005) Travessia - Revista Do Migrante, São Paulo, Centro De Estudos Migratórios, (51)Ugarte, A.S., Margens míticas: A Amazônia no imaginário europeu do século XVI (2003) Os Senhores Dos Rios, , In: DEL PRIORY, M.GOMES, F. (Org.) Rio de Janeiro: Campu

Effects of low intensity ultrasound on the germination of corn seeds (Zea mays L.) under different water availabilities

The effects of low intensity ultrasound on the performance of corn seeds (Zea mays L.), were investigated at two intensity levels, 230 and 175 mW/m². This study analysed the ultrasound effects on the germination under different water availabilities. The emergence and development of embryonic structures do react proportionally to the water availability and the treatment with ultrasound has no pronounced influency on the phenomena related to seed germination. However, a tendency of positive interference of this treatment in the seedling development in hidrie deficiency situations is detectable.Foram estudados os efeitos do ultra-som de baixa intensidade (230 e 1750 W/m²) sobre o desempenho de sementes de milho (Zea mays L.) utilizando situações variáveis quanto à disponibilidade hídrica. A emergência e o desenvolvimento de estruturas embrionárias reagem proporcionalmente à disponibilidade de água, não havendo influência marcante do tratamento com ultra-som nos fenômenos envolvidos na germinação das sementes. Contudo, são detectáveis tendências indicadoras de interferência positiva desse tratamento no desenvolvimento das plántulas em situações de deficiência hídrica

Spin separation in digital ferromagnetic heterostructures

In a study of the ferromagnetic phase of a multilayer digital ferromagnetic semiconductor in the mean-field and effective-mass approximations, we find the exchange interaction to have the dominant energy scale of the problem, effectively controlling the spatial distribution of the carrier spins in the digital ferromagnetic heterostructures. In the ferromagnetic phase, the majority and minority carriers tend to be in different regions of the space (spin separation). Hence, the charge distribution of carriers also changes noticeably from the ferromagnetic to the paramagnetic phase. An example of a design to exploit these phenomena is given.Comment: 4 pages, 3 figures. Submitted to Phys. Rev.

Topological Charged Black Holes in High Dimensional Spacetimes and Their Formation from Gravitational Collapse of a Type II Fluid

Topological charged black holes coupled with a cosmological constant in $R^{2}\times X^{D-2}$ spacetimes are studied, where $X^{D-2}$ is an Einstein space of the form ${}^{(D-2)}R_{AB} = k(D-3) h_{AB}$. The global structure for the four-dimensional spacetimes with $k = 0$ is investigated systematically. The most general solutions that represent a Type $II$ fluid in such a high dimensional spacetime are found, and showed that topological charged black holes can be formed from the gravitational collapse of such a fluid. When the spacetime is (asymptotically) self-similar, the collapse always forms black holes for $k = 0, -1$, in contrast to the case $k = 1$, where it can form either balck holes or naked singularities.Comment: 14 figures, to appear in Phys. Rev.

Radar probing of surfactant films on the water surface using dual co-polarized SAR

Microwave radar is a very perspective tool for all-weather monitoring of film slicks which appear in radar imagery of the water surface as areas of reduced backscattering due to damping of short wind waves. Information about the backscatter variations obtained from single band/one polarization radar seems to be insufficient for film characterization, so, new capabilities of multi-polarization radar for monitoring of film slicks have been actively discussed in the literature. In this paper results of new field experiments on remote sensing of film slicks using dual co-polarized radars: a satellite X-band TerraSAR-X and recently designed at IAP RAS a Multifrequency Radar Complex - three-band scatterometer operating in X-/C-/S-bands and mounted onboard a ship are presented. Along with backscattering depression the variations of polarized (Bragg) and non polarized radar backscatter components in slicks were analyzed. It is obtained that VV-to-HH backscatter ratio is smaller than the ratio predicted by a Bragg (two-scale) model thus indicating that additional, non polarized (NP), component also contributes to the total radar backscatter. Assuming the radar backscatter to be a sum of polarized (Bragg) and NP components the latter was eliminated from the total radar backscatter, and contrasts for the Bragg and NP components were obtained. The contrasts for the polarized component allowed us to estimate damping of gravity-capillary wind waves at Bragg wavelengths in slick and to give more accurate comparison with models of wave damping due to elastic film

Critical Collapse of Cylindrically Symmetric Scalar Field in Four-Dimensional Einstein's Theory of Gravity

Four-dimensional cylindrically symmetric spacetimes with homothetic self-similarity are studied in the context of Einstein's Theory of Gravity, and a class of exact solutions to the Einstein-massless scalar field equations is found. Their local and global properties are investigated and found that they represent gravitational collapse of a massless scalar field. In some cases the collapse forms black holes with cylindrical symmetry, while in the other cases it does not. The linear perturbations of these solutions are also studied and given in closed form. From the spectra of the unstable eigen-modes, it is found that there exists one solution that has precisely one unstable mode, which may represent a critical solution, sitting on a boundary that separates two different basins of attraction in the phase space.Comment: Some typos are corrected. The final version to appear in Phys. Rev.