alternative theoretical perspectives have been presented to explain internationally effective factors affecting immigration. for example, the orthodox explanation of migration is based on the concept of wage differentials as an important factor of international immigration. the world system approach declines to interpret theoretically international migration as a phenomenon between independent ...

extended abstract 1. introduction immigration plays an important role in reducing poverty and vulnerability in low- income families. people for various reasons, specifically, economic, social, cultural, environmental, and natural disasters leave their native land. so far in our country, people often have migrated from rural areas to cities. in recent years, however, we are witnessing the revers...

An international workshop on animal migration was held at the Lorentz Center in Leiden, The Netherlands, 2-6 March 2009, bringing together leading theoreticians and empiricists from the major migratory taxa, aiming at the identification of cutting-edge questions in migration research that cross taxonomic borders.

Cell migration is fastest when the strength of the adhesion between the cell and the substrate is neither too strong nor too weak. In this issue of Cell, reveal how adhesion and cytoskeletal dynamics are integrated to optimize migration speed.