Dr. Richard Schlegel and postdoctoral fellow Nancy Palechor-Ceron use a microscope to look at human epithelial cells growing on mouse fibroblasts at Georgetown University Medical Center. Lauren Wolkoff/Georgetown University hide caption

itoggle caption Lauren Wolkoff/Georgetown University

Thousands gathered on the National Mall last week to protest the deaths of Eric Garner and Michael Brown. Some law students say their involvement in the protests means their exams should be postponed. Saul Loeb/AFP/Getty Images hide caption

itoggle caption Saul Loeb/AFP/Getty Images