The American scientist Joshua Lederberg, who has died aged 82, won the 1958 Nobel prize in physiology or medicine for showing that bacteria can conjugate and exchange small strips of genetic material. Among the consequences of this was the realisation that antibiotic resistance can be passed around between bacteria, rather than emerging from selective breeding of resistant strains. This opened new paths in genetic research. He went on to a distinguished career in science policy, advising government committees and presidents, heading Rockefeller University and writing a Washington Post column on science and society. Lederberg's father was an orthodox rabbi - the family had come to New York from Palestine - who wanted Joshua to follow in his footsteps.

One of the most difficult steps in the development of an expert system is the recruitment and exploitation of the domain wizards. Almost always it is necessary to establish teams of specialists to deal with the programming issues and the user interfaces as well as the incorporation of domain specific knowledge. Experts will communicate how they read a gel, or what is the canonical biological interpretation of DNA sequences conserved over phyletically diverse organisms. The computer scientist will rarely have an independent base of knowledge and experience for critical judgments about the wisdom thus received. Therein may lie the greatest hazards from the proliferation of expert systems; for much of that expertise is fallible.

Cohen, Design Considerations for a Program to Provide Consultations in Clinical Therapeutics, in Proceedings of San Diego Biomedical Symposium, February 1974.

Cohen, Design Considerations for a Program to Provide Consultations in Clinical Therapeutics, in Proceedings of San Diego Biomedical Symposium, February 1974.