Justin McCowan, 39, has Down syndrome and lives at home with his parents in Santa Monica, Calif. Benjamin B. Morris for NPR hide caption

itoggle caption Benjamin B. Morris for NPR

Houston Texans Coach Bill O'Brien (center) Chief Operating Officer Cal McNair (right) and Houston Chronicle reporter Brian Smith take the ALS Ice Bucket Challenge Thursday to raise money for the ALS Association. David J. Phillip/AP hide caption

itoggle caption David J. Phillip/AP

Clear and clean, bubble wrap is well-suited to serve as an array of tiny test tubes. Here a dye solution is injected into the bubbles to measure the hemoglobin concentration in blood. American Chemical Society hide caption

itoggle caption American Chemical Society

The heart beats in a mouse embryo grown with stem cells made from blood. Now the research that claimed a simple acid solution could be used to create those cells has been retracted. Courtesy of Haruko Obokata hide caption

itoggle caption Courtesy of Haruko Obokata

The CRISPR enzyme (green and red) binds to a stretch of double-stranded DNA (purple and red), preparing to snip out the faulty part. Illustration courtesy of Jennifer Doudna/UC Berkeley hide caption

itoggle caption Illustration courtesy of Jennifer Doudna/UC Berkeley

A high-resolution image of the molecular carrier that moves the botulinum toxin from the intestine into the bloodstream. The carrier (silver) creates gaps in the gut lining by grabbing the rope-like molecules (red ribbons) that tether one intestinal cell to the next. Rongsheng Jin, UC Irvine, and Min Dong, Harvard Medical School hide caption

itoggle caption Rongsheng Jin, UC Irvine, and Min Dong, Harvard Medical School

Made for a tight grip: The female penis of an insect species newly discovered in Brazil has spines on it. Courtesy of Current Biology, Yoshizawa et al. hide caption

itoggle caption Courtesy of Current Biology, Yoshizawa et al.

Kent Stephenson, a research participant at the University of Louisville's Kentucky Spinal Cord Injury Research Center, has his level of muscle activity and force measured by Katelyn Gurley. Courtesy of the University of Louisville hide caption

itoggle caption Courtesy of the University of Louisville

Cat Or Dog? Sure, you can easily tell the difference. But a machine may not be able to guess on the first try. iStockphoto hide caption

itoggle caption iStockphoto