The Sphene-Centered Ocellar Texture: An Effect of Grain-Supported Flow and Melt Migration in a Hyperdense Magma Mush

The sphene-centered ocellar texture consists of leucocratic ocelli with sphene (titanite) crystals at the center, enclosed in a biotite-rich matrix. This texture has been recognized worldwide in hybrid intermediate rocks. On the basis of structural, petrological, and geochronological data from selected outcrops of the Variscan Ribadelago pluton (NW Iberian Massif), we propose that the ocelli were formed by migration and accumulation of a residual melt through a plagioclase- and biotite-dominated crystalline framework. At the late stage of crystallization, the magma acted as a hyperdense suspension and reacted to the pressure gradient caused by the regional stress field, entering the domain of grain-supported flow. Microstructures reveal that aligned crystal domains arose in the crystal framework from the shearing and compaction of the crystal mush and behaved as magmatic microshears. Relative displacement of adjacent crystal clusters along these microshears corresponded to the onset of Reynolds dilatancy that generated an expansion of the crystal mush, involving melt migration and pore aperture. The mineralogy of the ocelli, dominated by andesine and sphene, represents the composition of the migrating melt. The chemistry of this late, Ti-rich melt stems from the incongruent melting of biotite. Magmatic sphene from the ocelli yields a U-Pb age of 317 +/- 1 Ma, which represents the final crystallization of the hybridized magmatic system. Moreover, this texture offers an opportunity to better understand the rheological behavior of highly crystallized magmas.

Wind farm construction impacts reindeer migration and movement corridors

Over the last decade, we have seen a massive increase in the construction of wind farms in northern Fennoscandia. Wind farms comprising hundreds of wind turbines are being built, with little knowledge of the possible cumulative adverse effects on the habitat use and migration of semi-domesticated free-ranging reindeer. We assessed how reindeer responded to wind farm construction in an already fragmented landscape, with specific reference to the effects on use of movement corridors and reindeer habitat selection. We used GPS-data from reindeer during calving and post-calving in the MalAyen reindeer herding community in Sweden. We analysed data from the pre-development years compared to the construction years of two relatively small wind farms. During construction of the wind farms, use of original migration routes and movement corridors within 2 km of development declined by 76 %. This decline in use corresponded to an increase in activity of the reindeer measured by increased step lengths within 0-5 km. The step length was highest nearest the development and declining with distance, as animals moved towards migration corridors and turned around or were observed in holding patterns while not crossing. During construction, reindeer avoided the wind farms at both regional and landscape scale of selection. The combined construction activities associated with even a few wind turbines combined with power lines and roads in or close to central movement corridors caused a reduction in the use of such corridors and grazing habitat and increased the fragmentation of the reindeer calving ranges.

Migration, unemployment and trade

Migration, Unemployment and Trade focuses on the issues of migration, welfare and unemployment in a trade and development framework. Several chapters of the book analyze the implications of internal labor mobility in a model designed to highlight its implications for regional welfare, urban unemployment, rural-urban dichotomy and structural adjustment. An important innovation in this work is the disaggregation of the economy and the use of separate utility functions to highlight non-homogeneity of preferences. The book also deals with international mobility of factors in different frameworks. In particular it concentrates on the highly emotive issue of legal and illegal migration. Thus this work incorporates interesting and important features of labor economics and factor mobility into trade and distortion theory.

State sovereignty and migration control: the ultimate act of discrimination?

Nations zealously guard their borders and carefully vet migrants. This consigns many people to live in states not of their choice and often diminishes their opportunities and their level of flourishing. In some cases it is the difference between life and death. The practice of imposing migration controls is discriminatory. In fact it is the ultimate form of discrimination: 'super-discrimination.' There is no logical or moral reason why non-nationals of a state should not have the same opportunities and freedoms as nationals in that state. One of the most common forms of discrimination is race - treating a person differently simply because of their place of birth. This is one of the clearest and most repugnant forms of discrimination because the location where a person is born is of course merely a happy or unhappy circumstance over which the individual has no control. An accident of birth should not qualify a person for extra privileges or opportunities. The world is a fairer place if to the maximum extent possible luck is taken out of the process for allocating benefits and burdens - which ought to be distributed on the basis of merit and dessert. This paper examines whether there are sound reasons for restricting the flow of world-wide people movement. The main arguments in favour of this policy, relating to security and national building, are ultimately flawed. This exposes a tragic irony given the great efforts that many Western states - which typically have the strongest migration controls - make to stamp out discrimination at the domestic level, and the vast array of international law anti-discrimination instruments, loudly trumpeted by Western nations. This is hypocrisy nearing its finest. The substratum of sovereign states upon which available international law is built is inherently discriminatory and in fact is probably responsible for more harm as a result of the innately discriminatory immigration policies than results from the cumulative operation of all domestic discrimination. The world should move towards loosening migration controls. This would have an enormous number of humanistic benefits, not the least of which is largely eradicating world hunger and poverty.

Making connections in a regional city: social capital and the primary social contract

Government policy in many countries encourages migration to regional centres to relieve pressure on major cities and to boost economic development. Migrants are more likely to remain in a new location if they have meaningful work and establish social connections there. This article explores how organisations and groups in a regional city provide newcomers with access to social capital resources which migrants can use to forge social connections. Past research has shown that migrants require a mix of linking, bridging and bonding social capital to form an effective primary social contract with their new home. This research suggests that regional cities – such as Geelong, Victoria – which are proactive in assembling diverse social capital resources and making them accessible to migrants, are more likely not only to receive more newcomers but also more likely to retain migrants and a skilled workforce. The findings have relevance to other regional centres.

Migration exhibitions and the question of identity: reflections on the history of the representation of migration in Australian museums, 1986-2011

Museums and Migration explores the ways in which museum spaces - local, regional, national - have engaged with the history of migration, including internal migration, emigration and immigration.

A Spatial Comparison of Short and Long Term Migration Trends in China

China’s floating population, those individuals who have migrated between counties or provinces for a period of longer than 6 months, account for 79 million individuals. If intracounty migration is also included, the number jumps to 145 million individuals or over 11% of the total population. This study examines the geographical differences in short and long term migration using ArcGIS to manipulate the spatial GIS data. The study shows that both short and long term migration (in absolute numbers) occurs more frequently near cities and in coastal regions. However, by normalizing the data by population size, the study eliminates the problems of population size on the size of the migrants. Using this normalized data, the study finds that western and northern counties have a large number of migrants present relative to the size of the population. Determining where this floating population migrates helps explain regional inequalities in employment opportunities.

Recent African immigration to South America: The cases of Argentina and Brazil in the regional context

Incluye bibliografía

Trafficking in persons, especially women and children in the countries of the Americas. A regional report on the scope of the problem and the governmental and non-governmental response

Includes bibliography

Human trafficking: a regional challenge

Includes bibliography

Expert Group Meeting on Migration, Human Rights and Development

Incluye CD-ROM

International migrations and regional economic development: a Caribbean perspective

Includes bibliography

Migration data collection, management, sharing in the Caribbean

Includes bibliography

Qualidade de vida em Porto Velho, Rondônia: perspectivas do processo de desenvolvimento regional

Esta tese de doutorado nasceu da escassez de estudos referentes aos efeitos das grandes obras, sobre a qualidade de vida das cidades. Nesse sentido, visando estudar exatamente esse problema dentro de um cenário amazônico, propôs-se pesquisar os efeitos das usinas hidrelétricas de Jirau e de Santo Antônio, em seu processo de construção, às margens do rio Madeira, em Rondônia e, assim, analisar a qualidade de vida dentro do perímetro urbano da cidade de Porto Velho, o que constituiu o objeto de estudo da presente investigação. Para tanto, buscou-se aporte na teoria do “Fetiche”, de Marx, na obra “O capital” (1980). Assim, procurou-se explicar a migração de trabalhadores, na busca por melhores salários e oportunidades de ganhos econômicos, nas obras das hidrelétricas mencionadas. A perspectiva teórica do “fetichismo da mercadoria”, de Marx (1967), desencadeou a inter-relação com os aspectos diretamente ligados ao âmago da presente tese, que se constitui numa Pesquisa de natureza qualitativa. Essa foi desenvolvida com base no método de Análise Fatorial, utilizando o programa estatístico SPSS, versão 17. Para isso, foram aplicados 1.449 questionários, distribuídos igualitariamente, em grupos de 21, para cada um dos 69 bairros da cidade. E, dessa forma, construir os índices de IQVU (índices de qualidade de vida urbana), segundo Santos e Martins (2002) e, para análises multifatoriais, de acordo com Hair et al. (2005) e com Santana (2007; 2005). A partir disso, os resultados obtidos permitiram concluir que o índice de qualidade de vida de Porto Velho, no período correspondente à fase anterior a chegada das usinas, à região, era de 0,452. Portanto, classificado como um índice de desempenho regular. Em relação à fase atual, esse índice apresentou uma queda de 15,31%, alcançando um valor de 0,392. Por consequência, considerado de ruim desempenho. Desse modo, permitiu-se concluir que a qualidade de vida de Porto Velho, conforme a opinião dos entrevistados, literalmente, piorou com a chegada das usinas hidrelétricas do rio Madeira, em Porto Velho/Rondônia. A relevância do presente estudo reside na análise do espaço intramunicipal e na integração dos dados provenientes da pesquisa de campo, com a informação gerada durante as análises. Isto levou a deduções lógicas, fundamentadas nos critérios adotados e decorrentes dos resultados das avaliações. Consequentemente, esse poderá servir como suporte às decisões políticas, sobre o planejamento de ações a serem executadas, para gestão do território no âmbito municipal.