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Daily briefing: Why protests haven’t lead to a surge in COVID-19

During protests, overall social distancing increased in big US cities. Plus, solar fusion reveals its final secret and Israel’s archaeological wealth is vanishing under concrete.

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The Sun

Neutrinos are released during nuclear fusion reactions in the Sun's core.Credit: Detlev Van Ravenswaay/Science Photo Library

Solar fusion reveals its final secret

The theories for why the Sun shines date back to the 1930s, but one crucial bit of evidence was missing. Now, physicists have found direct evidence for a type of reaction, involving carbon and nitrogen nuclei, in which four protons fuse into a helium nucleus. The smoking gun? Neutrinos, elementary particles the reaction releases. These zip straight out from the Sun’s core, reaching Earth just 8 minutes later. The carbon–nitrogen pathway is not the only type of fusion in the Sun, and it’s not even the main one — neutrinos from all the other reactions had been detected before — but it is thought to be the dominant energy source for larger stars.

Nature | 4 min read

The findings, which have not yet been peer reviewed, were reported on 23 June at the virtual Neutrino 2020 conference.

The heaviest known neutron star — or the lightest known black hole

Gravitational-wave observatories have witnessed a black hole, 23 times as massive as the Sun, gobbling up an enigmatic object. At 2.6 solar masses, it is thought to be too large to be a neutron star, the only other type of orb that current detectors are sensitive to. But if it is a black hole, it would be the lightest ever observed. The massive stars that collapse to form black holes should leave behind remnants at least twice that size, standard astrophysical models suggest. Astronomers tried to find clues by looking for light from the merger, but to no avail. The enlarged black hole is now “doomed to wander the vast emptiness of space, probably never emitting another peep”, says astrophysicist Cole Miller.

Science News | 5 min read

Source: Astrophysical Journal Letters paper

One year on, sickle-cell treatment shows promise

As the one year anniversary of her receiving a ground-breaking treatment for sickle-cell disease approaches, it’s good news for Victoria Gray — the first person in the United States to undergo CRISPR gene therapy to treat a genetic disorder. It’s too soon for scientists to reach firm conclusions about the long-term safety and effectiveness of the approach. But for Gray, life is very different from the severe pain attacks and frequent blood transfusions she experienced before. “It's hard to put into words the joy that I feel — being grateful for a change this big. It's been amazing,” said Gray

NPR | 7 min read or 6 min listen

Read more: Gene therapy is facing its biggest challenge yet: sickle-cell disease (Nature | 13 min read, from December)

COVID-19 coronavirus update

Bottle of Insulin injection with a syringe on black table and stainless steel background.

People with type 1 diabetes can't produce the hormone insulin.Bernard Chantal/Alamy

Coronavirus might trigger diabetes

Diabetes is already known to be a key risk factor for developing severe COVID-19, and people with the condition are more likely to die. Now evidence from the clinic and the laboratory suggests that the virus damages insulin-producing cells, triggering diabetes in some people. More research is needed, and it has begun: earlier this month, an international group of scientists established a global database to collect information on people with COVID-19 who show issues with their blood-sugar levels.

Nature | 5 min read

References: New England Journal of Medicine paper, Diabetes Research and Clinical Practice paper, Diabetes, Obesity and Metabolism paper & Cell Stem Cell paper

Protests haven’t led to a COVID-19 surge

The widespread protests in the United States against racism and police brutality that have gone on for more than three weeks do not seem to have led to spikes in COVID-19 infections. Researchers analysed mobile-phone location data from 315 of the largest US cities and found that the wider population tended to stay at home more, leading to an overall increase in social distancing. Scientists propose that wearing masks also helped, and that young protesters who might have been infected but not have severe symptoms would be missed out in the official COVID-19 numbers. “The fact is that we will just never know for sure, because there’s too many moving parts,” says epidemiologist Andrew Noymer.

Buzzfeed News | 6 min read

Reference: National Bureau of Economic Research working paper (not peer reviewed)

Notable quotable

“I thought we should do it in the reverse order and throw everything at the pandemic at the start.”

Epidemiologist Michael Baker, who contributed to New Zealand’s much-lauded coronavirus strategy, explains why he recommended that the country go hard on lockdown to give time to strengthen its “woeful” testing and contact-tracing capacities. (New Scientist | 4 min read)

Features & opinion

Aerial view of a main road running through an archaeological excavation site in Israel

Road building threatens the site of Tel Beit Shemesh, dating to at least the seventh century bc.Credit: Dr Z. Lederman, Tel Beth-Shemesh Excavations

Israel’s archaeology vanishes under concrete

Israel is in the middle of a building boom to house its rapidly growing population, but some researchers fear the country isn’t doing enough to conserve its wealth of archaeological sites. They say that financial incentives favour paving over sites, rather than saving them.

Nature | 13 min read

The Himalaya should be a nature reserve

The Himalaya straddles seven nations and has a unique ecosystem of mountain peaks that act like isolated islands to drive speciation. But this scientific wonderland has one of the world’s highest rates of deforestation, is facing rapid warming and is the site of border conflict between two nuclear powers, India and China. Environmental scientist Maharaj K. Pandit offers a vision of the Himalayan highlands transformed into a peaceful nature reserve, and that the huge public funds squandered on managing conflict are invested instead in infrastructure for health care, education, conservation and welfare.

Nature | 4 min read

How diplomacy helped to end the race to sequence the human genome

Twenty years ago, the race to sequence the human genome ended in a tie — thanks to some deft statecraft from the White House. At the announcement, bitter scientific rivals Francis Collins, then-director of the US National Human Genome Research Institute, and Craig Venter, founder of Celera Genomics, a company formed to commercialize genome data, stood shoulder-to-shoulder to share the glory. “Looking back… the fact that world leaders played a part in efforts to tie the race to sequence the human genome is striking,” says a Nature editorial. “It also serves as an unhappy reminder that, although biology has continued to progress, standards of statesmanship have fallen to previously unimaginable depths.”

Nature | 5 min read

Quote of the day

“The intensity of the odour is so preposterous that no fume cupboard can deal with it.”

Odour-chemistry expert Luca Turin explains why super-stinky organic compounds isocyanides and isonitriles — which smell like “a combination of hot metal and vomit” — are often banned from the lab. Researchers have found a way to tame the repulsive smell while keeping their valuable chemical properties. (Chemistry World | 4 min read)

The Institute of Astrophysics of the Pontificia Universidad Católica de Chile has just finished a blockbuster series of online talks — and now they’re all online for us all to enjoy. The series includes Nobel laureates James Peebles and Didier Queloz, Gruber prizewinners Sandra Faber and Volker Springel and Mathematica creator Stephen Wolfram on his “new fundamental theory of physics”. All will have Spanish translations, too.

Flora Graham, senior editor, Nature Briefing

With contributions by Davide Castelvecchi

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