  Dynamical properties of a Lennard-Jones binary mixture embedded in an off
lattice matrix of soft spheres are studied in the direct space upon
supercooling by molecular dynamics simulations. On lowering temperature the
smaller particles tend to avoid the soft sphere interfaces and correspondingly
their mobility decreases below the one of the larger particles. The system
displays a dynamic behaviour consistent with the Mode Coupling predictions. A
decrease of the mode coupling crossover temperature with respect to the bulk is
found. We find however that the range of validity of the theory shrinks with
respect to the bulk. This is due to the change in the smaller particle mobility
and to a substantial enhancement of hopping processes well above the cross over
temperature upon confinement.
