1. Sobolev Institute of Mathematics, 4 Acad. Koptyug Avenue, Novosibirsk 630090, Russia
2. Novosibirsk State University, 1 Pirogova st., Novosibirsk 630090, Russia
3. Laboratory of Applied Mathematics, University of Trento, Via Mesiano 77, Trento 38123, Italy
4. Max-Planck Institute for Plasma Physics, Boltzmannstr. 2, Garching 85748, Germany