美国国家公共电台 NPR Travel Ban Keeps Scientists Out of the Lab（在线收听）

LOURDES GARCIA-NAVARRO, HOST:

President Trump's travel ban, though lifted for now, threw tens of thousands of people into limbo. Among the groups affected are scientists. NPR's science correspondent Joe Palca has more now on how recent events have created uncertainty for the American scientific community.

JOE PALCA, BYLINE: Early last month, Hanan Isweiri left her lab at Colorado State University, where she's pursuing a Ph.D. in plant physiology, to fly home to Libya. Her father had just died, and she wanted to spend time with her mother. She was scheduled to return to Colorado 10 days ago. She caught a flight from Libya to Amman, Jordan, on her way back. But when she reached the gate for her connecting flight, ground agents told her that even though she had a valid student visa to re-enter America, she couldn't board the plane because of the new travel restrictions.

She returned to Libya and asked officials at Colorado State to help her sort things out. Isweiri says they told her - stay put.

HANAN ISWEIRI: They asked me to not go anywhere until they got this exception or something for me.

PALCA: That's Isweiri speaking to me by cell phone from Libya this past Thursday. A lot has changed since then. After a federal judge blocked Trump's order from going forward, the State Department said that visas like Isweiri's are valid again, and she was able to fly back into the country last night. But even with the temporary relief, the ban has hurt the scientific community, says Rush Holt. Holt is a physicist, a former member of Congress and now heads the American Association for the Advancement of Science. His organization holds its annual meeting later this month, and the uncertainty is taking its toll.

RUSH HOLT: The head of the World Academy of Sciences, which is headquartered in Trieste, Italy, sent a letter saying that he was canceling his plans because he is Sudanese and didn't expect to be able to travel.

PALCA: Holt says the freedom to communicate and collaborate with people from all over the world are fundamental principles for science.

HOLT: If you want science to thrive - and you'd better want science to thrive because that benefits society in so many ways - you really have to defend these principles.

PALCA: Even scientists from the seven banned countries who are already here say the new travel policy has been disruptive. Maryam Zahedian is a grad student in chemistry at Indiana University in Bloomington. Zahedian is from Iran. When I reached her by Skype, she told me she's worried the temporary travel ban is just a start.

MARYAM ZAHEDIAN: All this news, it just makes us so nervous. I cannot even focus for, like, 30 minutes. Like, doing my research, I will go back and check the news, check the Facebook to see if there is any new thing. So, I mean, I don't want to stay longer here if it's going to be like this.

PALCA: It's too early to say whether the ban will return. Opponents say it's unconstitutional. President Trump has vowed to see it reinstated. In the meantime, scientists - and many others - feel left in limbo.

Joe Palca, NPR News.