منابع مشابه
How old is leprosy?
features of drug trials whose presence or absence has been used to assess reports of trials (Ross, 1951; Mahon and Daniel, 1964; Reiffenstein et al., 1968). Such a method of assessing reports may, however, give the impression that if these requirements are met then the therapeutic trial must be reliable and valid. It overlooks the fact that many other pointsfor example, the selection of patient...
متن کاملHow old is human longevity?
Seeking to locate changes in longevity in hominin evolution, Caspari and Lee (2004) calculated a ratio of old to young adult dentitions in assemblages of fossil taxa. They found an especially large difference in this ratio between Neandertals and Upper Paleolithic modern humans. While the important question they addressed can only be answered with fossil evidence, their ratio, as we show here, ...
متن کاملHow old is your heart?
The traditional concept of the heart as a terminally differentiated postmitotic organ has been largely based on an influential study published in 1925 that reported the paucity or near-absence of cell division and mitosis in the human heart, which was in striking contrast with the regenerative capacity of eg, liver tissue.1 Additional arguments thought to support this concept are the absence of...
متن کاملHow old is your fold?
MOTIVATION At present there exists no age estimate for the different protein structures found in nature. It has become clear from occurrence studies that different folds arose at different points in evolutionary time. An estimation of the age of different folds would be a starting point for many investigations into protein structure evolution: how we arrived at the set of folds we see today. It...
متن کاملHow Useful Is Old Information?
We consider the problem of load balancing in dynamic distributed systems in cases where new incoming tasks can make use of old information. For example, consider a multi-processor system where incoming tasks with exponentially distributed service requirements arrive as a Poisson process, the tasks must choose a processor for service, and a task knows when making this choice the processor loads ...
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ژورنال
عنوان ژورنال: Nature
سال: 1994
ISSN: 0028-0836,1476-4687
DOI: 10.1038/371751a0