Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (01PL16036)
Stiftung Mercator and Volkswagen Stiftung
European Union’s Seventh Framework Programme for research, technological development and demonstration (619349)
Received: 31 December 2018
Accepted: 8 May 2019
First Online: 13 June 2019
Ethics approval and consent to participate
: The data acquisition procedure was approved by the local data protection authorities and the local ethics board (No. EA4/096/16, Ethics Board Charité, Campus Mitte). All participants gave their informed consent at the beginning of the study.
: Not applicable.
: The first author, HP, is a member of the editorial board. The other authors report no conflicts of interest.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.