Nexus is the environment within which Sarah Nexus and Derek Nexus both sit. This supports the user by providing a single interface from which both predictions can be made. Derek is a knowledge-base system where an expert has written rules after taking into account data together with an understanding of the chemical and biological determinants of mutagenicity. Sarah is a machine-learning statistical tool that automatically discovers relationships (rules). The two products produce independent predictions.
There is an overlap with training data – both have been trained with the curated public datasets that Lhasa Limited stores in Vitic Nexus. Other statistical systems will likely have been trained on significant portions of this data too. Derek Nexus has the added advantage of being able to use the confidential and proprietary datasets that we have access to through our various data sharing groups and collaborations. Sarah Nexus can not use this data since it is too transparent in the information that it returns to the user.