Blame for the absence of medicines to keep millions suffering from HIV/Aids in Africa alive should fall on the international community, which has failed to provide enough money to tackle the epidemic, according to controversial new research. The report, published yesterday in the Journal of the American Medical Association, says that the patents through which the drug companies' high prices are enforced do not, in fact, exist in much of Africa. But these findings were denounced by groups campaigning to get medicines to the developing world; they say the data is being used to try to get pharmaceutical companies off the hook.