A general relativistic effect in quasi-spherical objects as the possible   origin of relativistic jets
  Based on recently reported results, we present arguments that sign changes in proper acceleration of test particles on the symmetry axis and close to the r=2M surface of quasi-spherical objects - related to the quadrupole moment of the source - might be at the origin of relativistic jets of quasars and micro-quasars. 
L. Herrera and N.O. Santos