Colored electron micrograph of the bloodstream form of the Trypanosoma brucei parasite (blue) that causes African trypanosomiasis (also called sleeping sickness) in humans in the presence of an erythrocyte (red). The disease occurs primarily in sub-Saharan countries and affects mostly poor populations. Today, approximately 60 million people are at risk to be infected. This image relates to a paper that appeared in the Nov. 29, 2012, issue of Science Express, published by AAAS. The paper, by Lars Redecke at the University of Hamburg in Hamburg, Germany, and colleagues was titled, "Natively Inhibited Trypanosoma brucei Cathepsin B Structure Determined Using an X-ray Laser."