Arizona Republic:  “Inside the suite of a nondescript industrial park in west Phoenix, an armed security guard in a bulletproof vest guards dozens of tents filled with lush plants that supply medical-marijuana patients throughout the state. . . . When they need pointers on yielding the best harvest, they go to Bruce Barnes, a 32-year-old “master grower” who works for the center and specializes in growing highly potent marijuana that patients use to treat ailments ranging from cancer to chronic pain. Barnes helps patients and caregivers grow high-grade marijuana using sophisticated techniques to manipulate the plants with light, nutrients and air.”