CYTOKININS: SYNTHESIS OF 6-(3-METHYL-3-BUTENYLAMINO)-9-β-D-RIBOFURANOSYLPURINE (3IPA), AND THE EFFECT OF SIDE-CHAIN UNSATURATION ON THE BIOLOGICAL ACTIVITY OF ISOPENTYLAMINOPURINES AND THEIR RIBOSIDES

Nelson J. Leonard, Sidney M. Hecht, Folke Skoog, Ruth Y. Schmitz

Proceedings of the National Academy of Sciences · 1968 · 46 citations · 11 references

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Abstract

Humans become increasingly fragile as they age. We show that something similar may happen to states, although for states, the risk of termination levels off as they grow older, allowing some to persist for millennia. Proximate causes of their ...How states and great powers rise and fall is an intriguing enigma of human history. Are there any patterns? Do polities become more vulnerable over time as they age? We analyze longevity in hundreds of premodern states using survival analysis to help ...

References

11