On the polarization of the nucleon sea in the meson cloud model
  It is pointed out that the meson cloud model predicts a substantial polarization of the sea quarks of the nucleon due to interference of $\pi$ and $\rho$ exchanges. This polarization is strongly flavour dependent. The model gives an explanation of a strong increase in the structure function $g_1$ with isospin I=1 at small $x$. 
K.G. Boreskov, A.B. Kaidalov