Home  About us  Contact
 

Migration Streams (migration + stream)

Distribution by Scientific Domains
Humanities and Social Sciences83%

Selected Abstracts

Genetic mapping of Foxb1-cell lineage shows migration from caudal diencephalon to telencephalon and lateral hypothalamus

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2008
Tianyu Zhao
Abstract The hypothalamus is a brain region with vital functions, and alterations in its development can cause human disease. However, we still do not have a complete description of how this complex structure is put together during embryonic and early postnatal stages. Radially oriented, outside-in migration of cells is prevalent in the developing hypothalamus. In spite of this, cell contingents from outside the hypothalamus as well as tangential hypothalamic migrations also have an important role. Here we study migrations in the hypothalamic primordium by genetically labeling the Foxb1 diencephalic lineage. Foxb1 is a transcription factor gene expressed in the neuroepithelium of the developing neural tube with a rostral expression boundary between caudal and rostral diencephalon, and therefore appropriate for marking migrations from caudal levels into the hypothalamus. We have found a large, longitudinally oriented migration stream apparently originating in the thalamic region and following an axonal bundle to end in the anterior portion of the lateral hypothalamic area. Additionally, we have mapped a specific expansion of the neuroepithelium into the rostral diencephalon. The expanded neuroepithelium generates abundant neurons for the medial hypothalamus at the tuberal level. Finally, we have uncovered novel diencephalon-to-telencephalon migrations into septum, piriform cortex and amygdala. [source]

Migration Theories and First Nations Mobility: Towards a Systems Perspective,

CANADIAN REVIEW OF SOCIOLOGY/REVUE CANADIENNE DE SOCIOLOGIE, Issue 2 2006
MARTIN COOKE
Au Canada, la recherche sur la migration des autochtones vers les centres urbains a mis en avant l'importance de facteurs économiques, les mou-vements de retour étant expliqués comme un échec lié aux difficultés d'adaptation. Les facteurs sous-tendant la migration vers les villes ont été peu étudiés, et des études récentes ont mis l'accent sur l'ampleur des mouvements plutôt que sur d'autres théories. Cet article suggère des voies selon lesquelles on peut avoir recours à une approche systémique pour intégrer des facteurs des contextes politique, économique et social ainsi que des liens individuels, institutionnels et de culture de masse. The migration of Canadian Aboriginal people to cities has usually been understood as economically motivated, with return migration to Aboriginal communities resulting primarily from failure to adapt to urban life. However, the reasons underlying migration have rarely been directly addressed, and recent studies of migration have focussed on the size of flows, rather than relating this migration stream to theories of migration developed in other contexts. This paper suggests ways in which a systems perspective on migration can be used to incorporate elements of the political, economic and social context, as well as individual, institutional and mass culture links between the two areas. [source]

Struggling to Save Cash: Seasonal Migration and Vulnerability in West Bengal, India

DEVELOPMENT AND CHANGE, Issue 4 2003
Ben Rogaly
This article concerns an important but overlooked means by which able-bodied poor people get hold of lump sums of cash in rural West Bengal: seasonal migration for agricultural wage work. Drawing on a regional study of four migration streams, our main focus here is on the struggle to secure this cash by landless households in just one of those streams, originating in Murshidabad District. Case studies are used to illustrate the importance for women in nuclear families of maintaining supportive networks of kin for periods when men are absent. A parallel analysis is made of the negotiations between male migrant workers and their employers, at labour markets, during the period of work, and afterwards. The article then briefly discusses some of the contrasting ways in which remittances are used by landless households and owners of very small plots of land, in the context of rapid ecological change, demographic pressure and growing inequality. [source]

The Migration of Professionals: Theories and Typologies

INTERNATIONAL MIGRATION, Issue 5 2001
Robyn Iredale
In an historical context, highly skilled migration typically involved the forced movement of professionals as a result of political conflicts, followed by the emergence of the "brain drain" in the 1960s. In the current situation, highly skilled migration represents an increasingly large component of global migration streams. The current state of theory in relation to highly skilled migration is far from adequate in terms of explaining what is occurring at the high skill end of the migration spectrum. Continuing growth of temporary skilled migration is heralding changes in the operation of professions. Formal procedures for recognizing the skills of permanent immigrant professionals are breaking down as "fast-track" processes for assessing the skills of temporary professional migrants are put in place. The increasing globalization of firms and the internationalization of higher education are encouraging professions to internationalize. In this article, four professions are cited as case studies to show that professional inclusion/exclusion is no longer defined by national professional bodies alone. The operation of professions has become a transnational matter although the extent of internationalization varies with professions. Typologies for analysing professional migration flows are discussed and a sixth means of categorization, by profession or industry, is introduced to allow for the nature of interactions between the market, the state and the profession/industry. The question whether states should continue to be concerned about self-sufficiency in national professional labour markets in an increasingly globalized environment is also addressed. [source]

Describing migration spatial structure,

PAPERS IN REGIONAL SCIENCE, Issue 1 2002
Andrei Rogers
Migration; spatial structure; log-linear models Abstract The age structure of a population is a fundamental concept in demography and is generally depicted in the form of an age pyramid. The spatial structure of an interregional system of origin-destination-specific migration streams is, however, a notion lacking a widely accepted definition. We offer a definition in this article, one that draws on the log-linear specification of the geographer's spatial interaction model. We illustrate our definition with observed migration data, we discuss extensions and special cases, and proceed to contrast our definition and associated empirical findings against another measure having an alternative definition. [source]

Resources, population and migration in the Pacific: Connecting islands and rim

ASIA PACIFIC VIEWPOINT, Issue 3 2009
Brian Opeskin
Abstract This article examines international migration in the Pacific and argues that there should be still greater opportunities for the people of Pacific countries to migrate between their home states and the developed states of the Pacific Rim. The case for borders that are more permeable to human migration is based in part on the common Pacific predicament of poor resource endowments, rapidly growing populations, depletion and degradation of existing resources, and threats posed by anthropogenic climate change. Coupled with this is a history of colonisation that has left some Pacific peoples with liberal access to economic opportunities in developed states by virtue of their citizenship or preferential visa status, while others have no such opportunities. Both New Zealand and the United States have been reasonably generous in facilitating migration from Polynesia and Micronesia. It is Australia that stands out as the Pacific neighbour with the greatest capacity to develop new migration streams. The seasonal worker scheme announced by the Australian Government in August 2008 takes a cautious but valuable step along this path, yet there is scope for further expanding Pacific access by broadening the geographical, temporal and material scope of existing migration arrangements. [source]