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Distinctive age profiles result from certain types of mortality processes that affect modern African elephants. Large collections of fossil proboscidean bones sometimes have similar age profiles—for example, those of the Lehner and Dent assemblages are identical to age profiles seen in modern drought-caused die-offs. Two other samples of mammoths (one from the Fairbanks muck deposits and one from a site near Waco, Texas) have age profiles suggestive of a stable age distribution in a mature population, resulting in the first case from long-term attritional mortality, and in the other case from sudden “catastrophic” mortality. Other fossil proboscidean age profiles that show high proportions of prime-age adults may have resulted from prolonged or recurring die-offs.  相似文献   
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Municipal solid waste management and planning traditionally have been regarded as the responsibility of local government. However, the legal climate surrounding solid waste management has become more constrained, placing local government at the mercy of the private waste management industry, and eroding the effectiveness of local waste planning efforts. This article provides an overview of recent court decisions impacting local government solid waste management. It also discusses current congressional activity relating to interstate waste transport and flow control, and assesses the potential effects of such legislation on public solid waste management and on privatization issues raised by critics of local control.  相似文献   
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Spread-backwash processes are central elements in regional development thought. This article argues that the main spread-backwash processes produce developmental change that has a general spatial form. Straightforward models of the processes of government incomes and expenditure flows, private capital flows, intraregional trade, migration-commuting, and the diffusion of innovations provide the rationale for the general distance decay form of developmental impact. Each model is supported by evidence from the relevant literature. It is argued that there is not a dichotomous set of spread versus backwash processes, but rather that the same set of processes yields differential spatial impacts.  相似文献   
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This paper posits the importance of visual representations in cultivating a national consciousness among white Afrikaners in South Africa. It provides a case study of stamps issued to commemorate the centenary of the Great Trek in 1938 that sought to raise awareness of and funds for the Voortrekker Monument project. Although stamps are, ordinarily, symbols of banal nationalism, the Voortrekker stamps resonated strongly with the sentiments the Afrikaner volk (people). They reified an iconography of the Voortrekkers and the narrative of the Great Trek already embedded in a canon of texts, images and rituals. The paper provides a semiotic reading of the designs of the stamps and shows how they shaped the cultural imaginary of Afrikaners. Although the Voortrekker stamps were issued with the approval of the postal authorities, they were actually commissioned by the Sentrale Volksmonumentekomitee [Central People's Monuments Committee (SVK)], which had close ties to the National Party (NP) opposition. Although the project was largely state sponsored, the SVK insisted upon its autonomy. Thus the government sanctioned a project over which it exercised no jurisdiction. The United Party paid a price for accommodating sectional Afrikaner interests when it lost control of the state in 1948.  相似文献   
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