Systems and methods for operating transistors near or in the sub-threshold region to reduce power consumption are described herein. The methodology employs a blocking agent such as C5 ester derivatives, or 6-deoxy 13- derivatives of tetracycline, in combination with other tetracycline-type antibiotics as a synergistic combination of compositions to be administered simultaneously, sequentially or concurrently. For each of the disks in the pair, the data forming the mirror copy is physically located between the center of the disk and the data that is mirrored on the other disk. Time-based identifiers are generated based on the time-based other keys.