  We present a protocol based on continuous-variable quantum teleportation and
Gaussian post- selection that can be used to correct errors introduced by a
lossy channel. We first show that the global transformation enacted by the
protocol is equivalent to an effective system composed of a noiseless
amplification (or attenuation), and an effective quantum channel, which can in
theory have no loss and an amount of thermal noise arbitrarily small, hence
tending to an identity channel. An application of our protocol is the
probabilistic purification of quantum non-Gaussian states using only Gaussian
operations.
