Strong jump traceability and Demuth randomness
  We solve the covering problem for Demuth randomness, showing that a computably enumerable set is computable from a Demuth random set if and only if it is strongly jump-traceable. We show that on the other hand, the class of sets which form a base for Demuth randomness is a proper subclass of the class of strongly jump-traceable sets. 
Noam Greenberg and Daniel Turetsky
math.LO