Daily briefing: Why a negative COVID test is not a free pass to party

Don’t let a COVID test give you a false sense of security, say public-health leaders. Plus, the DIY technologies that are democratizing science.

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Voters in the Golden State passed Proposition 14, which will fund stem cell research over 30 years.Credit: Francine Orr/Los Angeles Times/Getty

Voters in California have approved US$5.5 billion in funding for stem-cell and other medical research, granting a lifeline to a controversial state agency. But scientists are split over whether the California Institute for Regenerative Medicine (CIRM) in Oakland is a worthwhile investment for the US state — or for the field of stem-cell research. “As scientists, everybody always welcomes additional funding,” says Arlene Chiu, former director of scientific activities at CIRM. “But as a Californian, one wonders if there are better ways to do this.”

Nature | 5 min read

You wouldn’t rewrite a blueprint while constructing the foundations of a building — and the same goes for genes for essential functions. Take, for instance the development of the body plan, the genes for which have altered very little over millions of years of evolution. Or so we thought. Researchers silenced and swapped genes in different Drosophila species and found that the most rapidly evolving ones were surprisingly likely to encode essential functions. The reason might lurk in the densely packed DNA ‘junkyard’ known as heterochromatin, which evolves very rapidly. Some genes that encode essential functions might have to keep evolving just to keep up with the changing DNA environment of the heterochromatin. “It’s almost like an arms race happening in the genome,” says evolutionary biologist Harmit Malik.

Quanta | 6 min read

Reference: eLife paper & bioRxiv preprint

COVID-19 coronavirus update

Los Angeles has seen a jump in coronavirus cases in all age groups, but the rise is particularly “alarming” among young adults, a county health official said. Above, cars line up for COVID-19 testing at Dodger Stadium.Robert Gauthier/Los Angeles Times/Getty

Why a negative test is not a free pass to party

“Testing on Thursday so you can party on Saturday: That doesn’t work,” warns Barbara Ferrer, director of public health for Los Angeles County in California. You might have received a false negative, you might have been in the early, undetectable stage of infection, or you might get infected after you took the test. Ferrer warned of the issue as the number of cases grew in young adults, who are driving the spread of COVID through the county’s ten million or so inhabitants.

Los Angeles Times | 5 min read

Show us the science behind pandemic policy

Too much of pandemic public-health policy is based on vague or missing science, writes science journalist Roxanne Khamsi. She cites some of the orders that have raised eyebrows, such as South Africa’s ban on the sale of open-toed shoes and Alberta, Canada’s super-short 48-hour quarantine. Rules without clear, science-based substantiation can erode public trust, argues Khamsi.

Wired | 6 min read

Notable quotable

Swedish Prime Minister Stefan Löfven announced a ban on public gatherings of more than eight people as the country seeks to come to grips with a second wave of the pandemic. (Reuters)

Features & opinion

For decades, researchers were baffled by fossils of bizarre living things that dated back to the Ediacaran period, around half a billion years ago. But evidence now suggests that some of these alien-like species were in fact animals — and some even had guts, segmented bodies and other sophisticated features. Discover these bizarre ancient species in the audio version of Nature’s feature, made even more delightful by the sonorous voice of Nature’s Benjamin Thompson.

Nature | 19 min listen

“The idea that scientists build their own equipment is as old as science,” notes neuroscientist Tom Baden, who co-founded an organization that provides training in open-science hardware in Africa. What’s new is the online availability of a vast array of free open-source designs, and the growing ease of building them using 3D printers and hobbyist electronics such as Arduino and Raspberry Pi. Coupled with open-source reagents, these resources are making advanced diagnostics accessible even in resource-poor regions that lack trained technicians, cold storage and reliable power.

Nature | 11 min read

The COVID-19 pandemic threatens to erode huge gains against HIV, tuberculosis, malaria and maternal mortality. As she dedicates herself to the fight against COVID-19, infectious disease researcher Francine Ntoumi looks for silver linings. “To get through my work day after day, this is how I see the COVID-19 pandemic: as an opportunity to build structures that will reduce the burden of all tropical diseases,” writes the head of the Congolese Foundation for Medical Research. “I do not want to think about a world where that does not happen.”

Nature | 5 min read

Image of the week

Credit: Dr. Igor Siwanowicz, HHMI/Nikon Small World

This is the ‘tongue’ — or radula — of a freshwater snail, magnified 40 times. Snails and other gastropods use their radula to scrape the algae that they feed on from rocks and other surfaces. The tiny comb-shaped structures at the edge function like teeth, scraping and cutting up the material before it is swallowed. This close-up was taken by molecular biologist Igor Siwanowicz. It has been colour-coded to show depth — the parts that are closest to the camera are bright pink, and the farthest away are blue. The shot won third place in the Nikon Small World 2020 photomicrography competition. See more of the month’s sharpest science shots, selected by Nature’s photo team.

Quote of the day

The successful transfer of four astronauts to the International Space Station on a SpaceX Crew Dragon spacecraft is a milestone, says Phil McAlister, NASA’s director of commercial spaceflight development. (The New York Times)

Today I’m streaming all Dolly Parton tunes to celebrate her helping to fund the Moderna COVID vaccine candidate. Parton’s US$1-million COVID-19 research fund has also supported research into convalescent plasma.

I’ll be working 9 to 5 tomorrow and I will always love your feedback on this newsletter. My happiness depends on you, and whatever you decide to do, please email briefing@nature.com.

Flora Graham, senior editor, Nature Briefing

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