Scale and Unitarity Effects at High Energies ============================================ Vladimir A.Petrov Division of Theoretical Physics, Institute for High Energy Physics, Protvino,Russia. Abstract: --------- I will consider the influence that hard scales have on the energy dependence of physical characteristics of high-energy collisions. As examples I will present: - total and exclusive cross-sections in gamma*-proton and gamma*-gamma* interactions (scale=photon virtuality); - heavy flavour contribution into F2 (scale=heavy quark mass); - charged hadron multiplicity in DIS (scale=photon virtuality); - charged hadron multiplicity in e+e- (scale=heavy quark mass). I will also discuss in what way one could take into account unitarity for off-shell amplitudes and what are related specific effects (e.g. does the Froissart-Martin bound still hold for off-shell amplitudes?). Note: V.Petrov will stay at DESY until 25.9. and will be available for further discussions.