This work was supported by Ministry of Science and Higher Education
(Poland) (project grant no. N N304 339633 to Kinga Łukasiewicz)
and the University of Gdańsk (task grant no. 530-L140-D242-15-1A).
The funding agencies had no involvement in study design; in the collection,
analysis and interpretation of data; in the writing of the report; and
in the decision to submit the article for publication.