Extracts of the rosy periwinkle, catharus roseus, have provided medicine with vincristine and vinblastine, drugs now available for treating cancer. the ability to find this species of plant and discover these drugs is a strong argument for

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.