L.V. Poskotinova - Dr.Sc. (Biol.), Ph.D. (Med.), Associat Professor, Head of Biorhythmology Laboratory, Federal Centre for Integrated Arctic Research, The Institute of Environmental Physiology, Russian Academy of Sciences; Professor of Northern (Arctic) Federal University named by M.V. Lomonosov, Arkhangelsk, Russia. E-mail: liliya200572@mail.ru D.B. Demin - Ph.D. (Biol.), Senior Research Scientist, Laboratory of Biorhythmology, Federal Centre for Integrated Arctic Research, The Institute of Environmental Physiology, Russian Academy of Sciences, Arkhangelsk, Russia. E-mail: denisdemin@mail.ru