1. Mechanics and Biotextile Research Laboratory, Riga Technical University, 3/3-20 Pulka Street, LV-1007 Riga, Latvia
2. Department of Theoretical Mechanics and Strength of Materials, Institute of Mechanics and Mechanical Engineering, Riga Technical University, 6B Kipsala Street, LV-1048 Riga, Latvia
3. Laboratory of Environmental Genetics, Institute of Biology, Faculty of Biology, Latvian University, Jelgavas Street 1, LV-1004 Riga, Latvia