This invention relates to novel derivatives of 4-hydroxybutyric acid and prodrugs thereof, and pharmaceutically acceptable salts of the foregoing. Each LED has a plurality of leads, a free end of the middle lead of the LED is bent perpendicularly and extending horizontally thereafter below the other leads. The engine control computer is configured to determine a threshold for a charging specific fuel consumption, calculate an instantaneous CSFC; and initiate active charging of the battery if the instantaneous CSFC is less than or equal to the threshold CSFC. The system is configured for any one of the games to enter a feature phase when a feature-triggering event occurs. A method of making positive electrode material for use in an alkaline rechargeable electrochemical cell comprising forming a metal ion solution and increasing the pH to precipitate positive electrode material with a crystallite structure of 120 \u212b or less in the 101 direction.