Compounds of the formula I:or pharmaceutically acceptable salts thereof,wherein Ar, X, m, R1, R2 are as defined herein. At least one user controls team designation definition for each of a plurality of computing appliances. A first plate line is connected to the first ferroelectric memory cell and a second plate line is connected to the second ferroelectric memory cell. One advantage of the invention is that the diameter of the upper sections of the LP column need no longer be larger than the diameter of the rest of the column system thereby increasing the capacity of the column system. The air scoop can be configured to significantly increase the drag of the aircraft from a first value when the air scoop is in the first position to a second value when the air scoop is in the second position.