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Tuma RS 《Science of aging knowledge environment : SAGE KE》2004,2004(4):nf11
NEW YORK CITY--Everyone has slow-witted moments: entering a room only to forget why, putting ice cream into the fridge, or blanking out on how to use the microwave. Some clinicians think that periodic mental lapses might help diagnose dementia with Lewy bodies (DLB), a scourge that kills brain cells (see DLB Case Study), although not all experts agree. Now, scientists have found that some cognitive blunders crop up more frequently in patients with DLB than in those with Alzheimer's disease (AD) or in healthy elderly individuals, according to work presented here on 15 January 2004 at an American Medical Association briefing for media. 相似文献
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This paper reviews some recent research in OR implementation and suggests that a new approach is required, which will take fuller account of the perceptions of managers concerned with the problem. Research games in business settings seem to offer a means for such approach. Some lessons learned from a business game used in this way are described and their implications for modelbuilders are discussed. 相似文献
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RS Stainton 《Omega》1984,12(1):11-18
Problems may be viewed from many different angles and in many different ways. The order in which facts are collected, the attitudes of the people involved in the problem, the climate in which the problem finds itself to be, all play their parts in determining what the problem is perceived to be and how it is tackled. This paper reports on the several ways in which an apparently simple problem was approached and recognises that the process of solution which is adopted can dictate the eventual outcome and determine what the recommendations will be. 相似文献
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In case there should be any doubt that the human predicament will soon be a global crisis the reasons why this must be so are discussed. The increased use of resources and the growing dependence on a fuel-based technology are crisis enough, but to this is added the growing population of the part of the world less advanced in technology, where attitudes are different and cannot be changed to conform to the richer population's idea of what is what in the world.Most of our problems are created because the total effect of an operation is not properly considered when it is undertaken for the part that is wanted. Thus the rich countries have got themselves into a predicament the fault for which the poor see lying entirely with the rich, while the rich see the danger in the growing poor populations.The mechanism of evolution by selection from spontaneous variety must be followed because we cannot foresee needs. To keep the process healthy we must retain room for manoeuvre and choice and we must studiously avoid trying to operate monolithic technological ways of maintaining our society.Policies should seek to anticipate the imminent pressures of the future so as to retain freedom of movement, and the most obvious policy should be to make the price of fuel artificially high to conserve resources and stimulate the right kind of new technologies. 相似文献
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This paper investigates the implications of using different types of panel data to study individual mobility by means of empirical analyses of data from the Panel Study of Income Dynamics on intercounty migration of white male heads of household in 1975–1980. While event history data are clearly superior to panel data for studying individual mobility, often event history data are unavailable. We examine the consequences of different panel designs (varying number and spacing of waves) and of different timings of the measurements of explanatory variables. The results indicate that: (1) measuring the covariates at the end of an interval can be misleading, especially if these covariates are likely to change during the interval as a consequence of mobility; (2) a study of the mobility of a group of individuals during a single short interval can lead to different conclusions from a study of the mobility of the same group of individuals during a single long interval; and (3) multiwave panel data have clear advantages over data from a single short interval or a single long interval. 相似文献
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Tuma R 《Science of aging knowledge environment : SAGE KE》2001,2001(1):oa5
Scientists have suspected for half a century that reactive oxygen species (ROS) are major instigators of aging. These byproducts of metabolism batter a wide variety of molecules within cells, and an organism's ability to repair the damage declines with age. Now, some researchers say they're wrapping up the case against ROS, at least for lower organisms. By counteracting this destruction with protective enzymes, researchers have extended the average lifetime of some invertebrates. But the verdict isn't in yet, because recent studies have revealed that ROS also make key contributions to normal cell signaling. 相似文献