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AbstractNiche construction theory, a branch of evolutionary biology, places emphasis on the capacity of organisms, through their metabolism, activities and choices, to modify natural selection in their environment and thereby act as co-directors of their own evolution as well as that of others. Humans are potent niche constructors, and understanding how niche construction regulates ecosystem dynamics is central to understanding the impact of human populations on their ecological and developmental environments. A classic example is provided by the evolution of dairying by Neolithic groups in Europe and the significant role played by storage in the development of the dairying niche. 相似文献
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Alexander Höbel 《Journal of Modern Italian Studies》2017,22(2):254-272
This article deals with the question of the relationship between the Italian Communist Party (PCI), the strategy of ‘riforme di struttura’ and reforms in Italy between the 1960s and 1970s, with particular reference to the construction of a modern welfare system. The goal of a universal social security system was set by the PCI from at least 1956. Later, the dialectic with the centre-left governments induced the Communists to strengthen and articulate their proposals on welfare, linking them to the overall design of an advanced democratization of the state and society. In the 1970s, and in particular during the ‘solidarietà democratica’, various proposals made by the Communist Party and the CGIL (Italian General Confederation of Labour) in previous years finally became law, beginning with the establishment of the National Health Service organized into local health units. The Communist Party insisted on performance quality rather than quantity. However, the welfare state is now suffering difficulties throughout the Western world. 相似文献
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CAMPFIRE programmes have been hailed internationally for the innovative ways in which they have sought to confront the challenges of some of Africa’s most marginal regions through the promotion of local control over wildlife management. In Zimbabwe, CAMPFIRE has been cast as an antidote to the colonial legacy of technocratic and authoritarian development which had undermined people’s control over their environment and criminalized their use of game. This article explores why such a potentially positive programme went so badly wrong in the case of Nkayi and Lupane districts, raising points of wider significance for comparable initiatives. Local histories and institutional politics need careful examination. The first part of the article thus investigates the historical forces which shaped attitudes to game, while the second part considers the powerful institutional and economic forces which conspired to sideline these historically formed local views. CAMPFIRE in Nkayi and Lupane was further shaped by the legacies of post‐independence state violence in this region, and the failure of earlier wildlife projects. This range of factors combined to create deep distrust of CAMPFIRE, and quickly led to open confrontation. 相似文献
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Alexander C. Vias 《Geographical analysis》2001,33(3):228-246
The relationship of gross migration to net migration is continuously undergoing reevaluation in the literature. However, one major finding by Beale (1969) that produced the famous u‐shaped curve has received little attention, a surprising situation considering the significant changes that have taken place in rural America since 1969. In this paper I use gross migration data from IRS returns for 1995–1998, and differentiate the rates using a number of classification schemes developed by the USDA and the Census Bureau. The results show that rural America is a diverse place, and that migration rates vary tremendously depending on the geographic, economic, and social characteristics of the county. Furthermore, the relationship between gross and net migration varies much more than previously suggested, especially in negative net migration counties, a finding with implications for migration theory and public policy. 相似文献