(Left to right): 614 Collection/Alamy Stock Photo; PA Wire/Press Association Images; Ella Maru Studio

Top stories: Student visa worries, a science march map, and why USDA scrubbed animal welfare reports

USDA blacks out animal welfare information

The U.S. Department of Agriculture late last week removed public access to tens of thousands of reports that document the numbers of animals kept by research labs, companies, zoos, circuses, and animal transporters—and whether those animals are being treated humanely under the Animal Welfare Act. The apparent reason: a lawsuit over alleged cruelty to a special breed of horse. Henceforth, those wanting access to the information will need to file a Freedom of Information Act request.


Grad students, postdocs with U.S. visas face uncertainty

As U.S. courts temporarily shut down President Donald Trump's ban on immigration from seven majority-Muslim countries last week, graduates and postdoctoral students already in the United States were weighing their options and trying to plan rationally in an unpredictable situation. Many are on student visas, which, depending on what the courts decide, may not be renewable. Others are part of a post-Ph.D. program, Optional Practical Training, which appears to be threatened by yet another Trump executive order that was leaked to the media last week.

Scientists turn food poisoning microbe into powerful cancer fighter

Cancer tends to stick around because it’s practically invisible to the body’s own defenses: The immune system doesn’t recognize the rogue cells because they aren’t foreign invaders. To activate the immune system to attack cancer, scientists have tried all sorts of tricks, including infecting cancerous tissue with bacteria. Now, scientists have modified Salmonella bacteria to trigger a powerful immune response against human cancer cells implanted in mice, shrinking the tumors and—for the first time—preventing them from metastasizing. If the technique can be replicated in humans, it would be a significant step forward for the field of bacterial cancer therapy.

The marches for science, on one global interactive map

Last week, a group of grassroots organizers officially announced that a March for Science would be held on 22 April in Washington, D.C. The demonstrations are meant to be a celebration of science, they say, as well as “a call to support and safeguard the scientific community.” With hundreds of thousands pledging to turn out, these marchers have really put themselves on the map, figuratively. And we’ve done it literally—with a global, interactive depiction that shows where marches will take place around the world.

Cheap plastic film cools whatever it touches up to 10°C

If heat is not your thing, rejoice: A thin plastic sheet may soon provide some relief from the intense summer sun. The film, made from transparent plastic embedded with tiny glass spheres, absorbs almost no visible light, yet pulls in heat from any surface it touches. Already, the new material, when combined with a mirrorlike silver film, has been shown to cool whatever it sits on by as much as 10°C. And because it can be made cheaply at high volumes, it could be used to passively cool buildings and electronics such as solar cells, which work more efficiently at lower temperatures.