In this talk I review some recent developments which shed light on the main
connections between structural glasses and mean-field spin glass models with a
discontinuous transition. I also discuss the role of quantum fluctuations on
the dynamical instability found in mean-field spin glasses with a discontinuous
transition. In mean-field models with pairwise interactions in a transverse
field it is shown, in the framework of the static approximation, that such
instability is suppressed at zero temperature.Comment: 9 Pages (including 5 Figures), Revtex, Proceedings of the XIV Sitges
Conference, June 1996 (Barcelona) Spai