Fig. 3. Response of cilia bundles to exogenous shear.

(a),(b) Vorticity and velocity vectors before and during perfusion. (c) Velocities u(z; 0) and $u\left(z;{\dot{\gamma }}_e\right)$, shear flow ${\dot{\gamma }}_{e}z$, and sum $Cu(z;0)+{\dot{\gamma }}_{e}z$ fitting $u\left(z;{\dot{\gamma }}_e\right)$, where $C=F\left({\dot{\gamma }}_e\right)/F(0)$. (d) Variation with shear of estimated force F, velocity V and shear rate $\dot{\theta }=\partial u(z)/{\partial z|}_{\ell }$ measured above cilia tips, and rate of work $W\propto \dot{\theta }V$ (overlapping $\dot{\theta }$), normalized by values at ${\dot{\gamma }}_e=0$. Shaded regions are 95% confidence intervals of averages over 10 samples.