“The developed approach can also identify the optimal sensors for target or partial observability, helping us reconstruct selected state variables from appropriately chosen outputs, a prerequisite for optimal biomarker design. Given the fundamental role observability plays in complex systems, these results offer avenues to systematically explore the dynamics of a wide range of natural, technological and socioeconomic systems (from the Abstract, “Observability of a complex systems”, 2013, PNAS Early Edition by Yang-Yu Liu, Jean-Jacques Slotine, Albert-László Barabási)