The original version of this article unfortunately contained a mistake in the author list. The name of one co-author is written wrong in the final version of the article; Dr Hans Ulrich Knappe should be Ulrich Johannes Knappe. The updated author list is provided below: Christian P. Miermeister, Stephan Petersenn, Michael Buchfelder, Rudolf Fahlbusch, Dieter K.Lüdecke, Annett Hölsken, Markus Bergmann, Ulrich Johannes Knappe, Volkmar H. Hans, Jörg Flitsch, Wolfgang Saeger and Rolf Buslei.