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The author examines the effect of rapid population growth due to migration on the parish of Tenango del Valle, Mexico, during the eighteenth century. She gives special consideration to the impact on quality of life in indigenous villages, especially for widows and female heads of households who were impoverished as a result of discriminatory land transactions. Data are mainly from the parish register for 1770.  相似文献   
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Danger: implants     
The superheated debate over breast implants awakened a sleeping giant of an issue clouding "medical devices"--the government's clumsy nomenclature for any medical product that is not a drug, from breast implants and artificial hips to X-ray machines and surgical thread. Some 130 categories of high-risk devices are in use with little or no proof of safety, reliability or effectiveness. All appeared before 1976, the year that the Food and Drug Administration got the authority to regulate such products. Under activist chief David Kessler and with added clout from a 1990 law, the FDA plans to scrutinize the entire 130-item list. Five will get special attention starting early next year: saline-filled breast implants, inflatable penile implants, testicular implants, heart-bypass pumps and cranial stimulators. U.S. News has looked at all five devices, using FDA data obtained through the Freedom of Information Act. In-depth computer analysis suggested that penile implants deserve closer examination. Why is clear from the following report.  相似文献   
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In this article we examine how increasing the reimbursement of physicians and expanding Medicaid eligibility affect access to care for children in Cook County, Illinois, which overlies Chicago. Using Medicaid claims and other data at the zip-code level, we compare the places where Medicaid children live with the places where all the physicians who treat children and those who accept Medicaid patients have their practices. Our findings suggest that the recent changes in legislation are unlikely to benefit extremely poor children, who are more likely to live in depressed inner-city areas, where there are few physicians. "Near-poor" children whose homes are dispersed throughout the county, who are now eligible for Medicaid as a result of the recent changes, are likely to see improvements in their access to care. Further changes in policy, aimed at enhancing the capacity of institutions providing care, could improve access for the children of the inner city.  相似文献   
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During preliminary examination of the body of a homicide victim, a peculiar red "fiber" was noticed and recovered. Initially believing this to be a carpet fiber, the item was subjected to fiber analysis. It was found to be a short coiled particle not like any known natural or synthetic fabric fiber. Subsequent examinations determined this "fiber" to be the larva of a common freshwater midge (Diptera; Chironomidae). Chironomid larvae have been observed on other bodies recovered from freshwater environments. Entomological studies of this organism have led to the conclusion that the presence of chironomid larvae indicates submersion of the body.  相似文献   
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