Before revision:  Moreover, the magnitudes of these thresholds can thwart attempts to use  model checking, simulation, or approximation by differential equations to formally verify the behaviors of such nanodevices at realistic population densities .
After revision:  Moreover, the magnitudes of these thresholds can thwart attempts to use simulation, model checking, simulation, or approximation by differential equations to formally verify the behaviors of such nanodevices at realistic population densities .