Hello Nature readers,
Today we hear that a man has survived with a titanium heart for 100 days, explore what anti-vaccine rhetoric in the US government will mean for the country’s health and discover the colour of mammals who lived alongside dinosaurs.

One hundred days with a titanium heart

An Australian man in his forties has become the first person in the world to leave hospital with an artificial heart made of titanium. The device — used as a stopgap for people with heart failure who are waiting for a donor heart — works as a continuous pump in which a magnetically suspended rotor propels blood in regular pulses throughout the body. The man lived with the device for more than three months until he underwent surgery to receive a donated human heart.

Make America contagious again?

Healthcare workers are fighting a measles outbreak in Texas, Oklahoma and New Mexico — grim evidence of what happens when vaccination rates drop. It’s an event that some US public-health researchers fear could become more common because of reduced government support for vaccination, both at home and as part of international public-health efforts abroad. They also worry about the influence of Robert F. Kennedy Jr, an activist against vaccination, who helms the country’s health system and has clouded his current pro-vaccine stance with references to alternative treatments.

Jurassic mammals had dark fur

Fossils that preserve the details of Jurassic and Cretaceous mammals in spectacular detail have allowed scientists to determine, for the first time, the likely colour of their fur. Researchers analysed tiny structures in the hair of a previously undescribed flying-squirrel-type creature — which they dubbed Arboroharamiya fuscus — and five other mammal fossils from what is now northeastern China. Compared with the hair of modern mammals, the shape and size of the structures suggest that the ancient animals were dark-coloured — a handy adaptation to “living in the shadow of the dinosaurs, quite literally”, says molecular paleobiologist Jasmina Wiemann.

US scientists: thinking of leaving?

Some scientists in the United States have told Nature that they are considering leaving the country in the wake of widespread disruption to research brought in by the administration of US President Donald Trump. The researchers say they are looking for opportunities in Europe, Australia and Asia. “There is the case to stay and fight”, but “I have to consider what is the best decision for myself, my family, my lab, my research and my mental health”, says one anonymous researcher.

How to teach research skills in a prison

For researchers Tessa Montague and Shai Berman, teaching a weekly neuroscience class to undergraduate students involves passing through a heavy-duty security check and leaving all technology outside the classroom. Their cohorts are incarcerated people in some of the most notorious maximum-security prisons in the United States. Although the students’ surroundings are bleak, many turn to the nature visible outside their windows to develop research questions, such as how groundhogs tell the time and whether flocks of birds have leaders. “It is our job to nourish these observations,” write Montague and Berman.

Futures: Science fiction from Nature

A doctor has been treating children with ‘temporal disorders’ for more than 20 years, just not in chronological order in Medical records from the Center for the Study of Temporal Disorders, Pediatric Department.

Podcast: Sapphire anvils press 2D metals

Using a hydraulic press containing two sapphire anvils, researchers have created sheets of 2D metal less than one nanometre thick. For comparison, the thickness of a human hair is around 100,000 nanometres. Squishing metals such as bismuth allows researchers to study the materials’ unique properties in two dimensions, but they’ll need to refine the process to make sure it’s producing exactly what they’re looking for. In 2D, bismuth “atoms can actually adopt different configurations”, says physicist Javier Sanchez-Yamagishi. “Depending on what structures are created the properties will be different.”