  In the first part of the talk the interesting new results of MINOS, OPERA and
CMS collaborations (connected with the observational evidence of the rise in
the muon charge ratio at muon energies around 1 TeV) are briefly discussed from
theoretical point of view. A short review of charge asymmetric effects in muon
energy losses is given. In the second part of the talk, the modern theoretical
approaches to the problem of heavy quark production in high energy
nucleon-nucleus interactions are briefly considered (color dipole formalism,
saturation models). The recent new theoretical developments in the ancient
problem of intrinsic charm are also discussed.
