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The authors incorporate data from skeletal remains in an attempt to construct health profiles for the Amerindian population before Columbus's arrival and for the antebellum black slave populations of North America and the Caribbean. They examine the impact of poor nutrition among slaves, as evidenced in bone and tooth samples, on infant and childhood mortality, fertility, and adult mortality. They go on to suggest that the change from a hunter-gatherer life-style to a more sedentary agricultural one resulted in poorer health for the Amerindian population. However, agriculture made soft foods more available, allowing women to wean their children earlier, thus increasing overall fertility. 相似文献
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In this paper we consider the problem of vehicle routing using fixed delivery areas. This is the problem of splitting the area serviced by a depot into a number of separate subareas—a single delivery vehicle being assigned to each subarea to supply all the customers within the subarea. A heuristic algorithm is developed for the problem based upon an initial allocation of customers to subareas followed by customer interchanges in an attempt to improve the subareas. Computational results are presented for a number of test problems drawn from the literature. 相似文献
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