  We describe the results of 3D simulations of the interaction of hydrodynamic
shocks with Bonnor-Ebert spheres performed with an Adaptive Mesh Refinement
code. The calculations are isothermal and the clouds are embedded in a medium
in which the sound speed is either four or ten times that in the cloud. The
strengths of the shocks are such that they induce gravitational collapse in
some cases and not in others and we derive a simple estimate for the shock
strength required for this to occur. These results are relevant to dense cores
and Bok globules in star forming regions subjected to shocks produced by
stellar feedback.
