A Chinese scientist was arrested while arriving in the US at the Detroit airport, the second case in days involving the alleged smuggling of biological material, authorities said on Monday. The scientist is accused of shipping biological material months ago to staff at a laboratory at the University of Michigan. The FBI, in a court filing, described it as material related to certain worms and requires a government permit. “The guidelines for importing biological materials into the US for research purposes are stringent, but clear, and actions like this undermine…