[1] Cornell Univ, Dept Math, White Hall, Ithaca, NY 14853 USA
[2] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85281 USA
[3] Santa Fe Inst, Santa Fe, NM 87501 USA
[4] Univ Oxford, Rudolf Peierls Ctr Theoret Phys, Dept Phys, Oxford, England
[5] Princeton Univ, Dept Ecol & Evolutionary Biol, Princeton, NJ 08544 USA
[6] UCL, Ctr Adv Spatial Anal, London, England
[7] Univ Padua, Dept Phys & Astron, CoMuNe Lab, Padua, Italy
[8] Fdn Bruno Kessler, CHuB Lab, Povo, Italy
[9] Korea Univ, Dept Phys, Seoul, South Korea