  In this paper we investigate qualitative and asymptotic behavior of solutions
for a class of diffusion-aggregation equations. Most results except the ones in
section 3 and 6 concern radial solutions. The challenge in the analysis
consists of the nonlocal aggregation term as well as the degeneracy of the
diffusion term which generates compactly supported solutions. The key tools
used in the paper are maximum-principle type arguments as well as estimates on
mass concentration of solutions.
