Rita van der Walt (VIDEO) Stellenbosch University This video is under embargo. Please login to access this video. Caption Researcher Rita van der Walt talking about the research Credit Stellenbosch University Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.