Funding for this research was provided by:
German Federal Ministry of Education and Research (01LN1311A)
Article History
Received: 28 October 2016
Accepted: 13 January 2018
First Online: 24 January 2018
Compliance with ethical standards
:
: The authors declare no conflict of interest. The funding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.