Homeostasis is an essential property of all living organisms by keeping the internal environments of organisms and cells at approximately constant levels despite influences and perturbations from the internal or external environment. How organisms and cells can achieve such a robust internal stability is presently not thoroughly understood.
To get a better understanding of the nature of homeostatic mechanisms, Oleg Agafonov in his PhD combined thesis methods from molecular biology, chemical kinetics and cybernetics. One particularly intriguing question is whether cells may maintain an internal homeostasis under oscillatory signalling conditions, for example during oscillatory calcium signalling. By applying mathematical models it was found that certain oscillatory systems are indeed capable to keep the average level of a controlled component at a given set-point.
Furthermore, it was shown that the frequency of such biological oscillators can be kept robustly at a certain value. Another question addressed in this PhD work was how plants and fungi can homeostatically regulate essential nutrients, such as iron and nitrate and how homeostasis in general appears to be related to growth. Mathematical models were developed, which show how controlled and uncontrolled growth can occur. The occurrence of uncontrolled growth appears to be of particular interest, because the appearance of uncontrolled growth in cancer cells is still not well understood.
About the PhD candidate
Oleg Agafonov is 30 years old, with a Master of Science degree in Applied and Commercial Biotechnology from Hedmark University College, Norway.
The PhD project is entitled “Homeostasis and Adaptation: From Stationary Conditions to Oscillations and Growth”. The work was conducted at the Centre for Organelle Research in cooperation with the Department of Electrical Engineering and Computer Science, both at the University of Stavanger.
Lars Gunnar Dahle