共查询到20条相似文献,搜索用时 20 毫秒
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C A Dragstedt 《Federation proceedings》1977,36(11):2509-2510
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G Dunea 《BMJ (Clinical research ed.)》1983,287(6400):1203-1204
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G Dunea 《BMJ (Clinical research ed.)》1977,1(6061):632-633
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G Dunea 《BMJ (Clinical research ed.)》1977,1(6068):1069-1070
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In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant additional prediction, whereas median household income did not. Deaths from internal causes (diseases) show similar age patterns, despite different absolute levels, in the best and worst neighbourhoods, whereas deaths from external causes (homicide, accident, suicide) do not. As life expectancy declines across neighbourhoods, women reproduce earlier; by age 30, however, neighbourhood no longer affects age specific fertility. These results support the hypothesis that life expectancy itself may be a psychologically salient determinant of risk taking and the timing of life transitions. 相似文献
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Highly specializedpollination systems, such as figs and their wasp or orchidsthat deceive bees in trying to make them mate with their floralorgans, are intuitively appealing to most people and have, therefore,gained far more attention both in popular and scientific literaturethan the more generalized pollination systems. For a long timethe dominant view was that many, or perhaps even most, plantpollinatorinteractions were specialized. In 1996 Waser and his colleaguestried to stir things up by writing an article in which theyargued that, in contrast to common belief, generalization waswidespread in plantpollinator systems. Ten 相似文献