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A method is described for the preparation of vertebral body and rib sections of archaeological context, for scanning electron microscopy (SEM). The specimens included in the present paper are macroscopically normal and are male and female in juvenile and adult age brackets. The changing directionality of trabeculae and the changing ratio of trabecular bone to cancellous space are noted in relation to the age at death.  相似文献   
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Efforts to address HIV/AIDS have brought new opportunities and resources to LGBT (lesbian, gay, bisexual, transgender) activism in many parts of the developing world. However, increased attention in terms of both political opportunities and economic resources is uneven across the diverse population of LGBT peoples and activists. Lesbian activists have reaped far fewer benefits than their gay men counterparts. Building on existing approaches to movement visibility and invisibility, we posit a ‘political economy of in/visibility’ to analyse lesbian activism in China and Myanmar, where activists face particularly restrictive political and economic conditions. Rather than focus on visibility as a movement pre‐condition, objective or strategy, we examine the sources of in/visibility and their interactions with activists’ agency; in/visibility emerges from political and economic conditions, but is continuously reshaped by activists who negotiate them. We demonstrate that, despite challenges, lesbian activists respond in ways that help advance LGBT rights advocacy broadly, sometimes even with tactics that their more visible gay counterparts avoid. These interactions subsequently influence the conditions that shape in/visibility. Investigating the political economy of in/visibility, therefore, has significant implications for understanding not only lesbian activism, but also LGBT advocacy and collective mobilization, especially under politically and economically restrictive conditions.  相似文献   
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Recognizing that the vogue of postmodernism has passed, Simon Susen seeks to assess whatever enduring impact it may have had on the social sciences, including historiography. Indeed, the postmodern turn, as he sees it, seems to have had particular implications for our understanding of the human relationship with history. After five exegetical chapters, in which he seems mostly sympathetic to postmodernism, Susen turns to often biting criticism in a subsequent chapter. He charges, most basically, that postmodernists miss the self‐critical side of modernity and tend to overreact against aspects of modernism. That overreaction is evident especially in the postmodern preoccupation with textuality and discourse, which transforms sociology into cultural studies and historiography into a form of literature. But as Susen sees it, a comparable overreaction has been at work in the postmodern emphasis on new, “little” politics, concerned with identity and difference, at the expense of more traditional large‐scale politics and attendant forms of radicalism. His assessment reflects the “emancipatory” political agenda he assigns to the social sciences. Partly because that agenda inevitably affects what he finds to embrace and what to criticize, aspects of his discussion prove one‐sided. And he does not follow through on his suggestions that postmodernist insights entail a sort of inflation of history or historicity. Partly as a result, his treatment of “reason,” universal rights, and reality (including historiographical realism) betrays an inadequate grasp of the postmodern challenge—and opportunity. In the last analysis, Susen's understanding of the historical sources of postmodernism is simply too limited, but he usefully makes it clear that we have not put the postmodernist challenge behind us.  相似文献   
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When solving a location problem using aggregated units to represent demand, it is well known that the process of aggregation introduces error. Research has focussed on individual components of error, with little work on identifying and controlling total error. We provide a focussed review of some of this literature and suggest a strategy for controlling total error. Consideration of alternative criteria for evaluating aggregation schemes shows that the method selected should be compatible with the objectives of the analyses in which it is used. Experiments are described that show that two different measures of error are related in a nonlinear way to the number of aggregate demand points (q), for any value of the number of facilities (p). We focus on the parameter q/p and show that it is critical for determining the expected severity of the error. Many practical implementations of location algorithms operate within the range of q/p where the rate of change of error with respect to q/p is highest.  相似文献   
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