Marc Fogel, a Pennsylvania schoolteacher, has been release from Russian prison. NPR's Ailsa Chang talks with his sister, Anne Fogel, about how the family is feeling now.

NPR's Ailsa Chang talks with Nancy Krieger, a social epidemiologist at Harvard University, about her efforts to preserve federal health data that recently disappeared ...

NPR's Ailsa Chang talks with Jennifer Herricks, the founder of Louisiana Families for Vaccines, a group that organized a ...

NPR's Ailsa Chang speaks with Democratic Rep. Jamie Raskin of Maryland about the Trump administration's move to effectively close down the United States Agency for International Development, or USAID.

Hey to both of you. REGINA BARBER, BYLINE: Hey. EMILY KWONG, BYLINE: Hi, Ailsa. CHANG: OK, so you guys have brought us three science stories that caught your attention this week. Tell us what they ...

NPR congressional correspondent Deirdre Walsh joins us now from the Capitol with more. Hi, Deirdre. DEIRDRE WALSH, BYLINE: Hey, Ailsa. CHANG: OK, so what are Republicans saying about Musk’s Department ...

Hi, Sacha. SACHA PFEIFFER, BYLINE: Hi, Ailsa. CHANG: OK, so how many migrants are there already at this point? PFEIFFER: At least one planeload of 10 people so far, and Defense Department photos ...

NPR's Ailsa Chang talks with Emily Kwong and Regina Barber of Short Wave about the fluid dynamics of crowds, an early fossil of a modern bird and new data on how people's moods change through the day.