High-gain nonlinear observers occur in the nonlinear automatic control theory and are in standard usage in chemical engineering processes. We apply such a type of analysis in the context of a very simple one-gene regulation circuit. In general, an observer combines an analytical...

There are many theories of mortality, but no consensus even on the basic problem: is it genetically determined? In a general case, the problem is mathematically unsolvable. Yet, in the case of mortality, a physical approach yields its universal law. The law predicts, e.g., that mortality and...

A macroscopic approach to the tumor Gompertzian growth is proposed and successfully applied to the multicellular tumor spheroid data. It is based on the energetic balance among the different cell activities, related to the growth inhibitor factors. The main results can also be described by...

The accounts of medical trials provide very detailed information about the patients’ health conditions. On the contrary, almost no vital data such as marital status or age distribution are usually given. Yet, some of these factors can have a notable impact on the overall death rate, thereby...