In these images, E coli bacteria harbor proteins from a bacteria-killing virus that can eavesdrop on bacterial communication. At left, one protein from the virus has been tagged with a red marker. At right, the virus has overheard bacterial communication indicating the bacteria have achieved a quorum; it sends its protein to the poles of the cell (yellow dots). Bonnie Bassler and Justin Silpe, Department of Molecular Biology, Princeton University hide caption
The USNS Comfort, a U.S. Navy medical ship, floats off the coast of Riohacha, Colombia. The medical vessel is on a four-country tour of the region, providing medical assistance. Jim Wyss/Miami Herald/TNS via Getty Images hide caption
Yvonne Aki-Sawyerr, the new mayor of Freetown in Sierra Leone, speaks at the 2018 Concordia Annual Summit in New York City. "For decades, there had been no structure, no focused thinking of a strategy for the city," she says. "The way my brain works is with plans. I have to have a to-do list." Riccardo Savi/Getty Images hide caption
Shireen Mazari, center, the Human Rights Minister in Pakistan, tweeted that 18 aid groups were asked to leave the country for spreading disinformation. B.K. Bangash/AP hide caption
A woman in Johannesburg, South Africa, uses an HIV kit that tests for antibodies in oral fluids. Mujahid Safodien/AFP/Getty Images hide caption
A migrant receives medical attention at a former paper factory in Greece that has been turned into a makeshift camp. Menelaos Michalatos/SOPA Images/LightRocket via Getty Images hide caption
Thick clouds emanate from a coal-burning power plant in Baishan, in the Jilin province of China. In an effort to boost its economy, China has recently started greenlighting coal projects that had been on hold. Christian Petersen-Clausen/Getty Images hide caption
Schoolchildren in Namibia, which scored high marks for "child-friendliness" in a new ranking of African countries. Eric Lafforgue/Getty Images hide caption
Blac Chyna poses with her new face cream, Whitenicious, in a video ad on her Instagram. The ad creates a glamorous image to appeal to a high-end audience for the $250-a-jar product. blacchyna via Instagram/Screenshot by NPR hide caption
A medical worker holds a measles-rubella vaccine at a health station in Banda Aceh, Indonesia. Chaideer Mahyuddin/AFP/Getty Images hide caption
A woman attends a march marking the International Day for the Elimination of Violence Against Women in Asuncion, Paraguay, on November 25. Paraguay is one of the Latin American countries that has passed a law categorizing femicide — killing a woman because of her gender — as a specific crime. Jorge Saenz/AP hide caption
Triptych of charity advertisements from (L-R) Save the Children, CARE, and Dubai Cares. Save the Children/CARE/Dubai Cares hide caption
American biologist David Baltimore criticized a fellow scientist who claims he has edited the genes human embryos during the Second International Summit on Human Genome Editing at the University of Hong Kong. China News Service/VCG via Getty Images hide caption
Mehnaz sits inside her home in Abbottabad, northern Pakistan. She has one son and six daughters. She has also had three abortions, fearing she would have more girls. Diaa Hadid/NPR hide caption
Researcher He Jiankui spoke Wednesday during the 2nd International Summit on Human Genome Editing in Hong Kong. Kin Cheung/AP hide caption
Life Expectancy Alice Goldfarb/NPR hide caption
Health workers gather outside a newly built treatment center earlier this month in Bunia, Democratic Republic of the Congo. John Wessels/AFP/Getty Images hide caption
NPR producer Furkan Latif Khan doesn't like to leave her home in New Delhi without her breathing mask — although one doctor told her it might not help all that much. Furkan Latif Khan hide caption