We study quasilinear reaction diffusion systems relative to the Shigesada-Kawasaki-Teramoto model. Nonlinearity standing for the external force is provided with mass dissipation. Estimate in several norms of the solution is provided under the restriction of diffusion coefficients, growth rate of reaction, and space dimension.

We introduce $d-\delta$ systems on differential forms in Eucliean spaces and show the interface vanishing of the solution. This result generalizes previous theorems on stationary and non-stationary Maxwell's equation. Other applications are also given.