1. Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol'shoi pr. 31 (V.O.); St. Petersburg 199004 Russia
2. Faculty of Physics; St. Petersburg State University, Ul'yanovskaya str. 1, Petrodvorets; St. Petersburg 198504 Russia
3. Theory of Polymers and Soft Matter Group; Technische Universiteit Eindhoven, PO Box 513; MB Eindhoven 5600 The Netherlands