Butterflies exposed to radiation leaking from a damaged nuclear power plant in Japan have been observed to have malformed legs and Tanner and wings. For future butterflies to have structural abnormalities and gene mutations what must be present in the affected butterflies

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.