Reversal is generally described as the percentage of the maximum rated voltage that reverses polarity. It marks the boundary between heliospheric magnetic field regions of opposite polarity. Sunspots usually appear in pairs of opposite magnetic polarity. This is determined by the polarity of the voltage on the highly curved electrode. This EMF reverses its polarity when it moves under magnetic poles of opposite polarity. This process results in parallel sections of oceanic crust of alternating magnetic polarity. NPHP gene mutations cause defects in signaling resulting in flaws of planar cell polarity. Reversed phase SPE separates analytes based on their polarity. The function of neurons depends upon cell polarity. The devices have two removable antennas connected through Reverse Polarity TNC connectors. Some use negative DC polarity, or AC. Supercapacitors are polarized and must operate with correct polarity. Notch signaling is required in the regulation of polarity. Thus the centrosome is also important in maintaining the polarity of microtubules during mitosis. Only strands of like polarity exchange DNA during recombination.