Before revision:  On this basis we develop a more general binding model that converges to the well-known form of sw in the absence of quenching , but can account simultaneously for hydrodynamic co-transport in the presence of signal quenching .
After revision:  On this basis we develop a more general binding model that converges to the well-known form of sw with constant signals , but can account simultaneously for hydrodynamic co-transport in the presence of signal quenching .