A Lost Secret: How To Get Kids To Pay Attention

Several circular herpes virus particles are seen near a cell membrane. Roseola herpes virus causes a childhood illness marked by skin rashes and now has been found in brains with Alzheimer's disease. NCI/Science Source hide caption

In these two two-cell mouse embryos, the surface of the embryos is outlined in orange, the DNA in the nucleus is indicated in blue and the activity of the LINE-1 gene is indicated via bright red spots. Ramalho-Santos lab/UCSF hide caption

Cars wait to enter Fort Bliss in El Paso, Texas, in 2014. The U.S. Army Base is one of four that likely will be tasked with housing immigrant children following a request Thursday by the Department of Health and Human Services. Juan Carlos LLorca/AP hide caption

Speaker of the House Paul Ryan, R-Wis., leaves after meeting with reporters before a House showdown on immigration, at the Capitol in Washington on Thursday. J. Scott Applewhite/AP hide caption

Home goods seller Wayfair and other e-commerce companies had attempted to challenge a South Dakota law that levies taxes on purchases made through certain online retailers. Jenny Kane/AP hide caption

Gelmy, 9, and sister Alexa, 4, climbing trees in the backyard of their family home in the Yucatan Peninsula. Adriana Zehbrauskas for NPR hide caption

Commerce Secretary Wilbur Ross prepares ahead of a Senate hearing on tariffs on June 20, in Washington, D.C. Jacquelyn Martin/AP hide caption

Charles Krauthammer, pictured on the Fox News Channel, died of cancer at the age of 68. His death was announced by the Washington Post, where he was a Pulitzer Prize-winning columnist in addition to his work as a commentator for Fox. Fox News Channel hide caption