  In the present work we compute the enhancement in the long time transport
coefficients due to correlated motion of fluid particles at high density. The
fully wave vecor dependent extended mode coupling model is studied with the
inclusion of an additional slow variable of the defect density for the
amorphous system.
  We use the extremely slow relaxation of the density correlation function
observed in the light scattering experiments on colloids to estimate the input
parameters for the model The ratio of long time to short time diffusion
coefficient is studied around the the peak of the structure factor.
