Which made Canseco’s second benefactor — Mike Wallace — all the more important. John Hamlin, a producer at 60 Minutes , had gotten a tip about Canseco’s book from a friend at another network. (The friend couldn’t act on it because his employer was a Major League Baseball rights holder.) Hamlin began calling baseball people and confirming the details. Almost no one would talk on the record, but they suggested that Canseco’s account was true. One of the few allegations Hamlin couldn’t verify was Canseco’s insistence that Roger Clemens was juicing.
The picture is murkiest with tornadoes. A hotter, wetter atmosphere should promote more severe thunderstorms, but it might also reduce the wind shear needed for those storms to spawn twisters. More tornadoes are being reported in the ., but there are more people looking for them with better instruments—and there’s been no documented increase in the past half century in the number of severe tornadoes. The spring of 2011 was one of the worst tornado seasons in . history, with monster twisters roaring through Tuscaloosa, Alabama, and Joplin, Missouri. But scientists don’t yet have the data or the theoretical understanding to say whether global warming was to blame.
The most commonly used AAS in medicine are testosterone and its various esters (but most commonly testosterone undecanoate , testosterone enanthate , testosterone cypionate , and testosterone propionate ),  nandrolone esters (most commonly nandrolone decanoate and nandrolone phenylpropionate ), stanozolol , and metandienone (methandrostenolone).  Others also available and used commonly but to a lesser extent include methyltestosterone , oxandrolone , mesterolone , and oxymetholone , as well as drostanolone propionate , metenolone (methylandrostenolone), and fluoxymesterone .  Dihydrotestosterone (DHT; androstanolone, stanolone) and its esters are also notable, although they are not widely used in medicine.  Boldenone undecylenate and trenbolone acetate are used in veterinary medicine .