Funding for this research was provided by:
Council for Scientific and Industrial Research, South Africa (JRF)
Text and Data Mining valid from 2019-04-16
Received: 2 January 2019
Accepted: 9 April 2019
First Online: 16 April 2019
Compliance with ethical standards
: The authors declare that that there is no conflict of interest between them.
: All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. All procedures performed in the study involving animals were in accordance with the ethical standards of the institution or practice at which the study was conducted.