Abstract: | We consider the nonnegative solutions to the nonlinear degenerate parabolic equation ut = (D(x, t)um − 1ux)x − b(x, t)up with m > 1, 0 < p < 1, and positive D(x, t), b(x, t). After obtaining the uniqueness and Hölder regularity results, we investigate the dependence of such phenomena as extinction in finite time and instantaneous shrinking of the support on the behaviour of D(x, t) and b(x, t). |