Power Functions and Heterogeneity

The linear and x-semilogarithmic plots are uninformative for such decisions. 

In a more realistic context, the observed data usually decay according to a sum 

When the real process generates power-law data, alternatively a sum of exponentials and power function models may be used. But  

Overall, a large number of drugs that exhibit apparently multiexponential kinetics obey power-law kinetics. The cogent question is why many of the observed time-concentration profiles exhibit power function properties. Although the origin of the power function remains unclear, some empirical explanations could elucidate its origin  

A power function can be related to the sum of an infinitely large number of exponential functions  

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