Is there a cure for paralyzing spinal injuries? Most neurosurgeons are doubtful, pointing to the central nervous system's most apparent inability to heal itself. But others dispute the point. NOVA explores the debate, the hopes for a cure and recent breakthroughs to help paralyzed patients.

Agriculture is America's biggest industry. This productivity, envied around the world, is also depleting the most essential ingredients in farming: water and soil. NOVA looks at the agricultural dilemma, the short term need for profit and long term needs of the land.