The present invention makes available methods and reagents for inhibiting cell growth or promoting cell differentiation comprising contacting the cell with a differeguline in a sufficient amount to inhibit cell proliferation or promote cell differentiation. Each memory cell of the plurality of memory cells includes a resistance element in a static resistance condition and two or more reversible resistance-switching elements. The nonlinear distortion compensation signal is generated at the receiverdemodulator side of the direct propagation channel and transmitted across the direct propagation channel to an input of a pre-distortion block at the transmittermodulator side of the direct propagation channel. The stator includes a plurality of teeth.