GREAT BEND - Beth Schneweis can see herself dashing after her young son, Christopher, as he runs off the airplane when they return from Germany this fall. Wednesday morning she was laughing out loud as she described the image that plays often in her mind. The sounds of his mother chuckling caused 5-year-old Christopher, strapped into his specially designed tilt chair, to roll his head toward her and smile. The idea of Christopher, who has cerebral palsy, walking off an airplane in a few months, after having additional stem cells injected into his spine at a clinic in Germany, is...