One-Loop Self Energy and Renormalization of the Speed of Light for some   Anisotropic Improved Quark Actions
  One-loop corrections to the fermion rest mass M_1, wave function renormalization Z_2 and speed of light renormalization C_0 are presented for lattice actions that combine improved glue with clover or D234 quark actions and keep the temporal and spatial lattice spacings, a_t and a_s, distinct. We explore a range of values for the anisotropy parameter \chi = a_s/a_t and treat both massive and massless fermions. 
Stefan Groote and Junko Shigemitsu