Investigaci��n de la migraci��n internacional en Latinoam��rica (IMILA) = Investigation of international migration in Latin America (IMILA)

Publicaci��n biling��e (Espa��ol e ingl��s)

Migraci��n internacional en Latinoam��rica (IMILA) = International migration in Latin America (IMILA)

Publicaci��n biling��e (Espa��ol e ingl��s)

Ecuador: return from migration and entrepreneurship in Loja

Drawing on data from a survey of returning migrants, this study examines the factors behind the decision to launch a business in Loja, Ecuador. The possible explanations fall under various headings: demographic characteristics, work experience abroad, reasons for returning, current situation, intention to re-emigrate, and activity before, during and after migration. The study also considers different concepts of ���entrepreneur���, as own-account worker and as employer. The results are analysed, first, using univariate tests and then estimating probit models. The variables most closely associated with a high probability of starting a business after returning from migration are entrepreneurial experience during the migration, and the fact of having returned voluntarily, as well as having worked in the host country in agriculture or the hospitality sector. Having university training and having worked in public administration before migrating are negative factors. Other influential variables are age and the wage or salary received abroad, but these are more nuanced.

Brazilian migration to Guyana as livelihood strategy: a case study approach

Este estudo de caso de metodologia mista foi conduzido com foco na migra����o brasileira para a Guiana como uma estrat��gia de sobreviv��ncia. O estudo examinou, descreveu e analisou o processo da migra����o e da adapta����o, e os impactos socioecon��micos e ambientais f��sicos e as preocupa����es associadas com as atividades de sobreviv��ncia destes migrantes na Guiana. Foram utilizados question��rios, entrevistas, document��rios, arquivos e observa����es (direta e participante) com o objetivo de obter um entendimento profundo do fen��meno em quest��o. O estudo confirma que atrav��s de um forte sistema de rede, os brasileiros de classes socioecon��micas e culturais mais baixas s��o capazes de adotar a migra����o como estrat��gia de sobreviv��ncia, �� medida que eles migram atrav��s de uma rota por passos (step-wise) pr��definida para a Guiana. Este sistema de rede permite aos migrantes responderem prontamente ��s novas atividades de sobreviv��ncia tanto interna como internacionalmente. Na Guiana, a minera����o e a prostitui����o s��o identificadas como as principais atividades de sobreviv��ncia que tem gerado conseq����ncias socioecon��micas tanto positivas quanto negativas e impactos ambientais negativos.

Wave equation depth migration using complex Pad�� approximation

Propomos um novo m��todo de migra����o em profundidade baseado na solu����o da equa����o da onda com densidade constante no dom��nio da freq����ncia. Uma aproxima����o de Pad�� complexa �� usada para aproximar o operador de evolu����o aplicado na extrapola����o do campo de ondas. Esse m��todo reduz as imprecis��es e instabilidades devido ��s ondas evanescentes e produz imagens com menos ru��dos num��ricos que aquelas obtidas usando-se a aproxima����o de Pad�� real para o operador exponencial, principalmente em meios com fortes varia����es de velocidades. Testes em dados de afastamento nulo do modelo de sal SEG/EAGE e nos dados de tiro comum 2-D Marmousi foram realizados. Os resultados obtidos mostram que o m��todo de migra����o proposto consegue lidar com fortes varia����es laterais e tamb��m tem uma boa resposta para refletores com mergulhos ��ngremes. Os resultados foram comparados ��queles resultados obtidos com os m��todos split-step Fourier (SSF), phase shift plus interpolarion (PSPI) e Fourier diferen��as-finitas (FFD).

Reproductive migration of fish and movement in a series of reservoirs in the Upper Parana River basin, Brazil

AbstractThis study evaluates the effectiveness of two fish passes at two hydropower dams (Canoas I and II) in the Upper Parana basin, which form part of a cascade of three reservoirs. Fish from 12 migratory species (3089 specimens) were captured during their ascending, reproductive migration and were tagged with hydrostatic tags. The recapture data (294 specimens over two consecutive years) showed that there is a strong tendency for the maintenance of ascending migration through reservoirs with fish passes but with differences in migratory activity within the same species. No eggs, larvae or juveniles of these species were found in samples collected over 5 years in the reservoirs above the fish passes. These data suggest that fish passes have contributed to the restoration of the migratory routes of adult fish but that in the absence of suitable spawning or nursery habitats for these species; they probably act as ecological traps and do not contribute to the recruitment of the species.

A test of large-scale reproductive migration in females of the amphidromous shrimp Macrobrachium acanthurus (Caridea : Palaemonidae) from south-eastern Brazil

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Evaluation of Different Conditions of Contact for Caprolactam Migration from Multilayer Polyamide Films into Food Simulants

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Evaluation of mesenchymal stem cell migration after equine tendonitis therapy

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Effects of lithium on the proliferation and migration of neuroblasts in the rostral migratory stream in adult mice

The discovery of neurogenesis in adult brains opened the possibility of cellular therapy strategies for the treatment of neurodegenerative diseases, such as Alzheimer���s disease. Neurogenesis in the adult brain occurs in two areas: subgranular zone of the hippocampus and subventricular zone (SVZ) of the lateral ventricles. Neurons that originate from the SVZ migrate to the olfactory bulb (OB) through the rostral migratory stream (RMS). In Alzheimer���s disease, there is a progressive neuronal dysfunction and degeneration, resulting in brain atrophy and cognitive impairments including olfactory dysfunction. Several studies have demonstrated that pharmacological treatment with lithium exerts positive effects on adult neurogenesis, and one pathway seems to be the modulation of factors that regulate the migration of neuroblasts. The objective of this study was to investigate whether treatment with lithium promotes the increase of migratory neuroblasts using as parameter the RMS. Adult male C57BL/6 mice were divided into control and lithium-treated groups. The animals were treated for 6 weeks and, at four different time points, i.e., 10 days, 7 days, 3 days and 1 day before the end of treatments, they received an injection of BrdU (cell proliferation marker). The animals were sacrificed by perfusion fixation and the brains were immunohistochemically labeled for BrdU for analysis of migrating neuroblasts in the RMS. The results showed that the number of BrdU+ cells in the RMS was not significantly different between the two groups, suggesting that lithium, alone, is not capable of increasing the number of neuroblasts migrating from the SVZ to the OB