Martin, M
Leffler, J
Smoląg, K I
Mytych, J
Björk, A
Chaves, L D
Alexander, J J
Quigg, R J
Blom, A M
Article History
Received: 9 October 2015
Revised: 20 November 2015
Accepted: 24 November 2015
First Online: 15 January 2016
Competing interests
: The authors declare no conflict of interest.