Hello Nature readers, would you like to get this Briefing in your inbox free every day? Sign up here.

Blood-drop test kit for HIV, hepatitis B, hepatitis C and syphilis, on white background.

Some at-home syphilis tests also detect multiple other infections, such as HIV and hepatitis C.Credit: Pixel-shot/Alamy

Home tests for sexually transmitted infections

Encouraged by the success of at-home tests for COVID-19, many researchers, policy-makers and affected communities have embraced self-testing for sexually transmitted infections (STIs). For example, in January, a California law went into effect that requires private health insurers to cover the cost of at-home STI testing. At-home kits have advantages: they allow individuals to test privately and affordably. But there are trade-offs: people do not receive the counselling that comes with in-person testing, and public-health departments might lose valuable statistics.

Nature | 7 min read

Australians vote for stronger climate action

Climate change was hardly featured in pre-election debates in Australia — but by ousting the incumbent Liberal-National coalition, voters have backed up polls suggesting that the issue is a top priority for them. The centre-left Labor Party will form a government led by new Prime Minister Anthony Albanese. Gains have also been made by the Greens and independent candidates, many of whom promised to do more about global warming than the former government. The result is “huge” for those pushing for more ambitious climate action in Australia, and “highlights a significant shift in the political landscape on these issues of climate and environment”, says marine geoscientist Jody Webster.

Nature | 4 min read

First pig kidneys transplanted into people

Kidneys from pigs that had been genetically modified to have human-like immune systems have been transplanted into two people who had recently died. The organs functioned successfully for more than two days. But some scientists are sceptical that the experiments had value. They argue that clinical trials in living people are the only way to find out whether transplants from pigs can help to alleviate the shortage of human organs.

Nature | 6 min read

Concern over stalled Mexican science bill

Researchers in Mexico are concerned that lack of progress over a stalled law might waste a prime opportunity to boost Mexican science. It has been almost a year and a half since Mexico’s Congress missed its deadline to approve a bill that would drastically overhaul how science and technology are governed. And a draft proposal developed by the country’s science agency, the National Council of Science and Technology (Conacyt), has drawn the ire of some researchers for offering “a centralized vision of science”.

Nature | 7 min read

Features & opinion

Dietary differences confound animal studies

Researchers are coming to understand the importance of an animal’s diet when designing experiments. “If it’s different between experiments, it’s an additional variable to be considered when explaining the results,” says molecular biologist Kristin Gribble. But trying to iron out all variation is not always the answer. “There’s only so much you can standardize about the life of a rat or a mouse before you start to negatively impact welfare,” notes behavioural neuroscientist Robyn Crook.

Nature | 7 min read

US PhD students face cash crisis

Salaries for PhD students in the biological sciences fall well below the basic cost of living at almost every institution and department in the United States. Crowdsourced findings — submitted by students, faculty members and administrators — show that, for example, the basic stipend for biology PhD students at the University of Florida is around US$18,650 for a 9-month appointment, about $16,000 less than needed to cover expenses such as food, health care, housing and transport. Some students earn significantly more through fellowships, but this can lead to disparities and might not cover the whole term of the PhD programme.

Nature | 9 min read

How mammals survived the asteroid

The asteroid impact that ended the dinosaur age 66 million years ago was both a moment of great peril and opportunity for the placental mammals that survived. They were small and had flexible, omnivorous diets — so they could eat whatever was available and more easily endured the chaos following the impact than larger carnivores. As ecosystems recovered, many animals that started to multiply belonged to a group of tiny mammals with flexible diets known as eutherians — which laid the foundation for the more than 6,000 mammalian species thriving today, from bats to whales to humans.

Scientific American | 15 min read

Where I work

Paolo Cherubini inspects an old violin in his lab in Switzerland

Paolo Cherubini is a senior scientist at the Swiss Federal Institute for Forest, Snow and Landscape Research in Zurich, Switzerland.Credit: Elisabetta Zavoli for Nature

Forest ecologist Paolo Cherubini uses dendrochronology — or tree-ring dating — to understand how trees grow and to investigate historical environmental conditions. In 2010, he was an expert witness in a legal case about a viola supposedly made in the sixteenth century. “Dendrochronology cannot precisely date when an instrument was made, but it can identify the most recent year that the wood it was made from was part of a growing tree,” he says. The instrument in question was a fraud: its wood showed that it could not have been made before the late eighteenth century. (Nature | 3 min read)