Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (DE2680/3-1)
Article History
Received: 30 September 2019
Accepted: 22 December 2019
First Online: 13 January 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: This material is the authors’ own original work, which has not been previously published elsewhere. The paper is not currently being considered for publication elsewhere. The paper reflects the authors’ own research and analysis in a truthful and complete manner. The paper properly credits the meaningful contributions of co-authors and co-researchers. The results are appropriately placed in the context of prior and existing research. All sources used are properly disclosed (correct citation). All authors have been personally and actively involved in substantial work leading to the paper, and will take public responsibility for its content.