Science

FILE- In this Friday, Feb. 8, 2019, file photo President Donald Trump arrives on Marine One on the South Lawn of the White House in Washington. Trump plans to sign an executive order directing federal agencies to prioritize research and development in artificial intelligence. The plan, called the American AI Initiative, comes after China and other countries have pledged big investments to advance and apply AI technology in fields ranging from warfighting to health care. (AP Photo/Carolyn Kaster, File)

FILE - In this Oct. 13, 2016 file photo, a trainer feeds a dolphin a fish, Thursday, Oct. 13, 2016, at Dolphinaris in Scottsdale, Ariz. The Phoenix-area aquatic facility says it's temporarily closing following the death of four dolphins since it opened in 2016. Officials announced Tuesday, Feb. 5, 2019, that the facility will voluntarily close Friday but there isn't an immediate timetable for reopening. (AP Photo/Matt York, file)

FILE - In this Oct. 9, 2018 file photo, an embryo receives a small dose of Cas9 protein and PCSK9 sgRNA in a sperm injection microscope in a laboratory in Shenzhen in southern China's Guangdong province, during work by scientist He Jiankui's team. On Thursday, Feb. 7, 2019, a Stanford University official said that the school has started a review of interactions that some faculty members had with He, who claims to have helped make gene-edited babies. (AP Photo/Mark Schiefelbein)

FILE - In this Jan. 20, 2017 file photo, Karen Pence holds a Bible as her husband, Vice President Mike Pence is sworn in during the 58th Presidential Inauguration at the U.S. Capitol in Washington. Chris Stroop, a writer and activist, introduced the #ExposeChristianSchools category on Twitter in January 2019 shortly after news broke that Karen Pence would be teaching at a Christian school in northern Virginia that lists "homosexual or lesbian sexual activity" as among the disqualifying criteria for prospective employees. (AP Photo/Andrew Harnik)

FILE - In this Aug. 27, 2014 file photo, a laptop computer monitors a patient's heart function as he takes a stress test while riding a stationary bike in Augusta, Ga. A report released on Wednesday, Jan. 30 2019 estimates that nearly half of all U.S. adults have some form of heart or blood vessel disease, a medical milestone that's mostly due to recent guidelines that expanded how many people have high blood pressure. (AP Photo/The Augusta Chronicle, Michael Holahan)

This Wednesday, Jan. 16, 2019 photo shows an iRobot Terra lawn mower in Bedford, Mass. Building a robot lawn mower seemed the logical next step for iRobot, which invented the pioneering robotic vacuum Roomba. But the company’s secret, decade-plus lawn mower project was a lot harder than anyone expected. (AP Photo/Elise Amendola)

FILE - In this Thursday, Jan. 17, 2019, file photo, France's President Emmanuel Macron speaks to military forces as part of his visit to the 11th Brigade of the Paratroopers of the Infantry at Toulouse-Francazal air base, near Toulouse, southern France. Macron aims to speak out stronger than in the past about human rights issues while in Egypt, where France seeks to reinforce strategic ties with a country he considers a key regional partner, he told reporters on Sunday, Jan. 27. (Guillaume Horcajuelo/Pool Photo via AP, File)