  High-pt particles produced in nucleus-nucleus collisions constitute a
powerful tool to study the medium properties. The energy loss resulting from
the propagation of these particles in the produced medium translates into a
suppression of the high-pt yields. These effects are usually associated to
medium-induced gluon radiation which, in turn, predicts a broadening of the
jet-like signals. Both the energy loss and the jet broadening are expected to
increase proportionally to the medium density. In the more realistic case of a
dynamically expanding medium, the gluon radiation becomes anisotropic due to
the presence of a preferred direction in the transverse plane with respect to
the axis of propagation. This anisotropy translates into deformed jet-shapes
which provide new posibilities to study these flows by high-pt measurements.
