Total Masses of Mixed Monge-Ampere Currents

Monge-Ampere currents generated by plurisubharmonic functions of logarithmic growth are studied. Upper bounds for their total masses are obtained in terms of growth characteristics of the functions. In particular, this gives a plurisubharmonic version of D.Bernstein's theorem on the number of zeros of polynomial mappings in terms of the Newton polyhedra, and a representation for Demailly's generalized degrees of plurisubharmonic functions.