In September 2008, Trains magazine reported that Xanterra would no longer operate its steam locomotives.  The decision came as a result of the 2000s energy crisis and the late 2000s recession conspiring against passenger numbers, although it was claimed to be an environmental decision. The railway's policy of always running a diesel with a steam locomotive as backup however does render the decision environmentally friendly. As part of the end of steam, 20 employees were laid off.  Around that time, both steam engines 29 and 4960 were placed on static display on the Williams Depot platform. Limited steam operation returned on September 19, 2009, with the engines being powered by waste vegetable oil . According to the GCR website, the service will be available during the 2011 season  with engine 4960. Over the winter of 2011/2012, engine 4960 underwent its 15-year overhaul and inspection, and returned to service in February 2012 for a special Centennial Run on February 14, 2012 celebrating 100 years of Arizona Statehood. Since then, engine 4960 continues to pull GCR excursions once per month during the summer months from May through September, and for special occasions.
Injectable steroids are injected into muscle tissue, not into the veins. They are slowly released from the muscles into the rest of the body, and may be detectable for months after last use. Injectable steroids can be oil-based or water-based. Injectable anabolic steroids which are oil-based have longer half-life than water-based steroids. Both steroid types have much longer half-lives than oral anabolic steroids. And this is proving to be a drawback for injectables as they have high probability of being detected in drug screening since their clearance times tend to be longer than orals. Athletes resolve this problem by using injectable testosterone early in the cycle then switch to orals when approaching the end of the cycle and drug testing is imminent.
In electrodynamic suspension (EDS), both the guideway and the train exert a magnetic field, and the train is levitated by the repulsive and attractive force between these magnetic fields.  In some configurations, the train can be levitated only by repulsive force. In the early stages of maglev development at the Miyazaki test track, a purely repulsive system was used instead of the later repulsive and attractive EDS system.  The magnetic field is produced either by superconducting magnets (as in JR–Maglev) or by an array of permanent magnets (as in Inductrack ). The repulsive and attractive force in the track is created by an induced magnetic field in wires or other conducting strips in the track. A major advantage of EDS maglev systems is that they are dynamically stable – changes in distance between the track and the magnets creates strong forces to return the system to its original position.  In addition, the attractive force varies in the opposite manner, providing the same adjustment effects. No active feedback control is needed.