  We review recent results concerning collective excitations in neutron-rich
systems and reactions between charge asymmetric systems at Fermi energies.
  Solving numerically self-consistent transport equations for neutrons and
protons with specific initial conditions, we explore the structure of the
different dipole vibrations in the $^{132}Sn$ system and investigate their
dependence on the symmetry energy. We evidence the existence of a distinctive
collective mode, that can be associated with the Pygmy Dipole Resonance, with
an energy well below the standard Giant Dipole Resonance and isoscalar-like
character, i.e. very weakly dependent on the isovector part of the nuclear
effective interaction. At variance, the corresponding strength is rather
sensitive to the behavior of the symmetry energy below saturation, which rules
the number of excess neutrons in the nuclear surface.
  In reactions between charge asymmetric systems at Fermi energies, we
investigate the interplay between dissipation mechanisms and isospin effects.
Observables sensitive to the isospin dependent part of nuclear interaction are
discussed, providing information on the symmetry energy density dependence
below saturation.
