Branes and massive IIA duals of 3d CFT's

We describe brane configurations that interpolate between the N=6 AdS4xCP3 background of Type IIA supergravity and the N=0 AdS4xCP3 background of massive Type IIA supergravity. Using the T-dual Type IIB configurations we prove that this leads to unequal Chern-Simons levels in the dual gauge theory, and find the precise relation between the parameters of the gauge theory and the RR fluxes of the background. This provides further evidence for the conjecture of Gaiotto and Tomasiello about the CFT dual of the massive Type IIA background.