  In-medium nucleon-nucleon scattering cross sections are explored by comparing
results of quantum molecular dynamics simulations to data on stopping and on
elliptic and directed flow in intermediate-energy heavy-ion collisions. The
comparison points to in-medium cross sections which are suppressed at low
energies but not at higher energies. Positive correlations are found between
the degree of stopping and the magnitudes of elliptic and directed flows.
