1. Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
2. Laboratoire de Physique Statistique, Ecole Normale Supérieure, Paris, France
3. Institute of Continuum Mechanics and Materials, Hamburg University of Technology, Hamburg, Germany
4. Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
5. Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
6. Mathematical Institute, University of Oxford, Oxford, UK
7. Department of Biomedical Engineering, Yale University, New Haven, CT, USA
8. Department of Mechanical Engineering, Stanford University, Stanford, CA, USA