  Two topics are presented. The first one is a novel approach for a Poincare'
covariant description of nuclear dynamics based on light-front Hamiltonian
dynamics. The key quantity is the light-front spectral function, where both
normalization and momentum sum rule can be satisfied at the same time.
Preliminary results are discussed for an initial analysis of the role of
relativity in the EMC effect in 3He. A second issue, very challenging, is
considered in a non-relativistic framework, namely a distorted spin-dependent
spectral function for 3He in order to take care of the final state interaction
between the observed pion and the remnant in semi-inclusive deep inelastic
electron scattering off polarized 3He. The generalization of the analysis
within the light-front dynamics is outlined.
