Abstract
The Pampas of South America represents one of the most extended subtropical–temperate grasslands in the world. This ecoregion was influenced by Pleistocene climate oscillations. The ...sigmodontine rodent assemblage inhabiting this region is a good model system to analyse the impact of these climate changes on evolutionary histories. We performed a comparative phylogeographical study on seven species to evaluate the concordance of phylogeographical patterns among them, to assess if they experienced congruent and synchronous demographic changes, and posit putative centres of origin and dispersal routes. Four species (Calomys musculinus, Oligoryzomys flavescens, Oxymycterus nasutus and Oligoryzomys nigripes) showed evidence of demographic expansion. In the first three, population increases started during Marine Isotope Stage 5 (MIS 5) while in Ol. nigripes, the rise started during MIS 7; this rise would have continued to the present in all cases. Necromys lasiurus, Scapteromys tumidus and Scapteromys aquaticus did not show a pattern of expansion. Four centres of origin were identified; in general, populations sharing the same putative refugium followed common dispersal routes. Our results indicate that the Pampas offered relatively stable habitats over time, mainly in areas associated with watercourses or coastlines, suggesting that recent Pleistocene climate oscillations have had a moderate impact on this ecoregion compared to other regions of South America.
The World in a City MacDonald, John; Sampson, Robert J.
The Annals of the American Academy of Political and Social Science,
05/2012, Letnik:
641, Številka:
1
Journal Article
Recenzirano
The United States in 2012 faces unprecedented challenges brought on by economic crisis and the unrelenting pace of globalization and technological change. We are perhaps unique as a nation, however, ...in the changes wrought by continuing population diversification and foreign immigration from countries across the globe. Indeed, the United States is currently one of the most diverse nations on earth, which spells to some observers coming ruin and to others unprecedented renewal. Whichever position one might take, there can be little doubt that immigration has radically changed the nations composition. Reprinted by permission of Sage Publications Inc., copyright The American Academy of Political and Social Science.
This article presents main indicators of population ageing in Republic of North Macedonia, Republic of Slovenia and Republic of Serbia. Main indicators used in this paper are proportion of old ...population and "older-old" population, old dependency ratio, ageing coefficient and median age. The aim is to observe and detect similarities and differences in the age structure of the region based on indicators of ageing. The results are shown that Serbia is a country with the oldest population: 13.8% old population, 3.6% "older-old" population, the old dependency ratio 25.45 people per 100 people of working age, and 42.5 median ages. The Republic of North Macedonia has a younger population compared to other countries.
The Pădurea Craiului Mountains represent the natural, cultural and living environment of some rural communities with a population that has been subject to various quantitative and structural changes. ...Being endowed with exploitable resources, this area has seen the rise and decline of some industries that which have generated a demographic dynamics characteristic of mining mountain areas. The Revolution from 1989 and the following period have represented a turning plate in the evolution of the economy of this space, with direct implications for the employed population in the economy before December.
Facing the demographic changes is our common responsibility as researchers of all scientific disciplines. The forecasts based on statistical data show that in many countries in the nearest future the ...highest growth in population will be in the segment of 65-year-olds and older people. With age, mobility, intellectual ability and spatial orientation are reduced. Creating a proper living environment and public spaces to conduct prevention and rehabilitation training would have a positive impact on shaping and maintaining the quality of life of residents. The purpose of this multidisciplinary research was to create a model training for people with motor dysfunctions together with an optimal design of environment to conduct it on daily basis. Currently, a great emphasis in the design of urban areas is placed on the physical and social activity of children and youth (playgrounds, skate parks, sports equipment), as well as people with a high degree of physical fitness (sports fields and equipment, outdoor gyms, running paths, nordic walking, cross-country skiing). The aim of the work was to explore the possibilities and prove effectiveness of basic functional training with sensory elements in non-standard activity spaces intended for people with reduced low physical activity and motor disorders, not requiring additional devices, using elements of nature, such as terrain, water, greenery - as well as elements of small architecture.
After the collapse of the socialist regimes in Central and Eastern Europe, urban environment began to change and the term post-socialist city appeared in urban theories. The post-socialist urban ...transition has been broadly examined in order to understand the processes transforming previously socialist cities. Although the essential differences between capitalist and post-socialist cities are described, there is a gap in understanding and interpreting the various trajectories of urban development among individual post-socialist cities. By using the conceptual framework of multiple transformations and methodical approaches of urban ecology, this paper reveals specifics of urban and socio-demographic changes of Brno and Bratislava and points to the limitations of the framework when evaluating divergent paths of post-socialist transformation. The spatio-temporal analysis provides an empirical evidence of distinct patterns of post-socialist transformations, which are related to the heterogeneity of socialist legacies, residential policy, and institutional factors with the capital status in particular, and shows that multiple outcomes of transformation are produced even in similar-sized cities with a common history of the same socialist state.
•Multiple transformations of the post-socialist cities produce multiple outcomes.•Housing market differentiation affects the ‘wealth-selective’ migration.•The capital status is essential in urban renewal.•Heterogeneous socialist-era path dependencies strongly influence the resulting social structure.
At the present time, demographic changes and migration are two economic and social challenges very debated within countries that are part of the Economic and Monetary Union, and also subject of ...various articles, books and studies. Over the years, various theories have attempted to explain demographic changes and migration and many economists and researchers tried to figure out the relationship between the two concepts and economic growth of both sending and receiving countries. The debates have argued the following statements: demographic changes and migration generally can promote, restrict or have no impact on the economy of a country. Likewise, the aim of this paper is to provide an analysis of the impact of demographic changes and migration on the economic growth of the EMU countries.This paper provides a theoretical framework of demographic changes and migration at international level, which emphasize the relevance and consequences of these two concepts on the economic growth of countries. Furthermore, is illustrated a summary of the Economic and Monetary Union, its main function and the benefits of the single currency in all European countries. An analysis of several demographic changes and migration indicators in EMU countries is also submitted, in order to highlight the situation in EMU countries. The research methodology entailed both quantitative and qualitative analysis. Statistical indicators regarding demographic changes and migration in EMU countries were used for research and a qualitative analysis made through discussions concerning the impact of demographic changes and migration on the economic growth of EMU countries. The results of this research emphasise that EMU countries are facing important demographic changes: an ageing population, low fertility rates, high duration of working, a high life expectancy at birth and a high number of immigrants. These changes could cause in the future important issues for the economy of the EMU countries. Furthermore, regarding the economic effects of migration for both sending countries and receiving countries, the debates have highlighted that can vary (both can experience gains/losses). In conclusion, EMU countries should take into account demographic changes and migration when they operate towards economic growth.
Do demographic shifts in the racial composition of the United States promote positive changes in the nation’s racial dynamics? Change in response to the nation’s growing diversity is likely, but its ...direction and scope are less clear. This review integrates emerging social-scientific research that examines how Americans are responding to the projected changes in the racial/ethnic demographics of the United States. Specifically, we review recent empirical research that examines how exposure to information that the United States is becoming a “majority-minority” nation affects racial attitudes and several political outcomes (e.g., ideology, policy preferences), and the psychological mechanisms that give rise to those attitudes. We focus primarily on the reactions of members of the current dominant racial group (i.e., white Americans). We then consider important implications of these findings and propose essential questions for future research.
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