  Circadian rhythms are archetypical examples of nonlinear oscillations. While
these oscillations are usually attributed to circuits of biochemical
interactions among clock genes and proteins, recent experimental studies reveal
that they are also affected by the cell's mechanical environment. Here we
extend a standard biochemical model of circadian rhythmicity to include
mechanical effects in a parametric manner. Using experimental observations to
constrain the model, we suggest specific ways in which the mechanical signal
might affect the clock. Additionally, a bifurcation analysis of the system
predicts that these mechanical signals need to be within an optimal range for
circadian oscillations to occur.
