A MECHANICAL SYSTEM INTERPRETATION OF THE NONLINEAR KINETICS OBSERVED IN BIOLOGIGAL AGEING
Scientific Glass Institute (InV), 10 boulevard Defontaine, B-6000 Charleroi, Belgium, guilbert.crevecoeur@euronet.be
Abstract
There is a widely observed nonlinear kinetics in the ageing of biological systems which is characterized by three successive stages: (1) the ageing rate is firstly high but decreases quickly to a minimum from which (2) it remains nearly constant during the major part of the process until (3) it starts increasing again up to the final collapse of the system. Such kinetics are also encountered in the ageing of mechanical systems. It is shown that a model useful for the follow-up of operating mechanical systems allows to find back typical curves and laws related to the ageing of biological systems (mortality rate curves, survival curves, growth curves, Gompertz law, ). The classical concepts of lifespan, longevity and life expectancy are given new light using the model, which also gives clues to explain both the discrepancy in the age of death of individuals in a given population and he wide range of lifespans of species encountered in nature. Finally, the model shows in which directions tests should be performed in order to accelerate to senescence for a better understanding of the underlying phenomena and for life prediction purposes