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Watch Nature Video’s introduction to the work to rewind the ‘biological clock’ in mice. (Nature on YouTube | 6 min video)

Vision regenerated in old and injured mice

Researchers have restored vision in old mice and in mice with damaged retinal nerves by resetting some of the thousands of chemical marks that accumulate on DNA as cells age. The work suggests a new approach to reversing age-related decline: reprogramming some cells to a ‘younger’ state in which they are better able to repair or replace damaged tissue. Researchers took genes known to cause cells to revert to a stem-cell-like state and inserted them into mice using a virus. They then triggered the genes to see whether they would help injured eye cells or those degraded by age. The results are “a major landmark” and “clearly show that tissue regeneration in mammals can be enhanced”, says developmental biologist Juan Carlos Izpisua Belmonte — but researchers caution that this result is still only in mice.

Nature | 5 min read

Reference: Nature paper

The science of the snap

Physicists have analysed the mechanism that underlies everything from Lego bricks to Ziploc bags: the snap fit. They simplified the ubiquitous connection, which forms when interlocking components click together to attach flexible parts, to a rigid cylinder and a plastic sheet. Most snap fits are easy to assemble but difficult to pull apart. This key quality “emerges from an exquisite combination of geometry, elasticity, and friction”, write study authors Keisuke Yoshida and Hirofumi Wada. Next: the ‘type-II snap’, which has the opposite qualities — it’s tough to click together, but easy to pull apart.

Inside Science | 5 min read

Reference: Physical Review Letters paper

Iconic Australian animals glow in the dark

Echidnas, wombats and bilbies are among the Australian mammals that glow under ultraviolet (UV) light. Scientists at the Western Australian Museum confirmed the effect in samples in their collection following the shock discovery last month of biofluorescence in platypuses (Ornithorhynchus anatinus). Many insects and sea creatures are known to be biofluorescent, but this trait has been identified in only a handful of mammals in the New World until now. “Their ears and tails shine bright like a diamond!” wrote the museum’s curator of mammalogy, Kenny Travouillon, of the sight of bilbies under UV light.

ABC News | 6 min read

Reference: Mammalia paper

COVID-19 vaccine update

Could COVID delirium bring on dementia?

Delirium is so common in COVID-19 that some researchers have proposed making the condition a diagnostic criterion. Researchers are testing whether these temporary bouts of confusion could lead to permanent cognitive decline later in life. In the past decade, long-term studies have revealed that a single episode of delirium can increase the risk of developing dementia years later. To begin to find answers, institutes around the world have funded a variety of studies into the long-term cognitive effects of COVID-19, some of which will look at delirium. “It’s going to be, I think, a little bit frightening and a little bit enlightening,” says neuropsychologist Natalie Tronson. “We’re learning quickly, but there’s still a lot of black boxes.”

Nature | 10 min read

What we want to know about vaccines

The United Kingdom has become the first country to authorize a COVID-19 vaccine that has been tested in a large clinical trial. Regulators in the United States and Europe are expected to issue their decisions on vaccine approvals in the coming weeks. The UK-authorized Pfizer–BioNTech vaccine has passed safety and efficacy tests — but scientists still have many questions about how it and others will perform as they’re rolled out to millions of people. Nature investigates what we know about how long the vaccines’ effectiveness will last, whether they stop people with asymptomatic infections from spreading the disease and how well they work in different groups. We also look at how they stack up against each other and whether the virus could evolve to evade the immunity given by vaccines.

Nature | 8 min read

The team investigating COVID’s origins

Ten scientists have been assembled to lead the World Health Organization’s investigation into the origins of the SARS-CoV-2 coronavirus in people, perhaps the biggest unsolved mystery of the pandemic. The researchers have expertise in spillover events (when the virus spills from animals to people), public health, animals and virology, and have worked on past outbreaks of Ebola and Middle East respiratory syndrome. But pinpointing the origin of any outbreak is challenging, and success is not a given. “We are all aware that there is no guarantee there will be a waterproof story on how it all started,” says veterinarian Fabian Leendertz, who is on the investigating team.

Nature | 5 min read

Is ‘covidization’ distorting research?

Coined in Nature Medicine in April by tuberculosis researcher Madhukar Pai, ‘covidization’ describes the outsized impact of the pandemic on the way science is being funded, produced, published and reported on. Scientists worry that the focus on threats related to COVID-19 means that research into other factors that are crucial for public health, from non-infectious diseases to climate change, could lose out. Scientists from different fields who have moved to COVID-related research might be contributing substandard work. And, given the deluge of papers and preprints, it’s increasingly hard for the public, media and policymakers to distinguish reliable evidence from the rest.

Nature | 5 min read

Notable quotable

“Doctors and nurses are very visible, but we work behind the scenes…. And we are underwater.”

Medical-laboratory scientist supervisor Marissa Larson is one of the COVID-testing lab technologists sharing how they are struggling under long hours, repetitive-stress injuries and intense pressure. (The New York Times | 12 min read)

A sustainable ocean economy

A free-diver dives amid plastic waste

Record-breaking Turkish diver Şahika Ercümen draws attention to plastic pollution in the Bosporus.Credit: Sebnem Coskun/Anadolu Agency/Getty

The ocean’s role in a healthy planet

“For too long, the ocean and seas, 71% of Earth’s surface, have been under-represented at some of the world’s most influential global environmental-policy processes,” says a Nature Editorial introducing a powerful initiative led by 14 world leaders — which this week has published important findings in Nature. (Nature | 6 min read)

Among them, these leaders manage nearly 40% of the world’s coastlines, 30% of the world’s exclusive economic zones, 20% of the world’s fisheries and 20% of the world’s shipping fleets. On the basis of the evidence accrued, they have committed to the sustainable management of 100% of their national waters by 2025. (Nature | 5 min read)

Ocean issues affect far more than the 14 countries of the Ocean Panel, admits Norwegian Prime Minister Erna Solberg, who co-leads the panel. “Still, we must start somewhere,” she writes. “We are hopeful our ranks will grow over time, because the benefits of better management are beyond doubt.” She describes how Norway no longer approaches oil, transport, fisheries, aquaculture and minerals separately, but monitors and manages ocean activities across sectors. (Nature | 5 min read)

Solberg spoke to Springer Nature’s editor-in-chief Philip Campbell in a special Nature Podcast about the world leaders’ bold pledges to protect and sustainably use the world’s oceans. (Nature Podcast | 15 min listen)

Policy commitments can’t come too soon. In September, more than 100 aquatic scientific societies, representing more than 80,000 aquatic scientists from all 7 continents, issued a call for urgent action to slow the impact of climate change on the freshwater and marine ecosystems that they study. “Fish biologists, we tend to be quiet and in the background. We don't like to put ourselves out there,” said Scott Bonar, who spearheaded the statement as president of the American Fisheries Society. But “if we don't control emissions, then a lot of our aquatic ecosystems as we know them can disappear. And it's happening right now. These changes are happening right now.” (azcentral | 10 min read)

Reference: The ocean in humanity’s future report & World aquatic scientific societies statement

Image of the week

Damage at the Arecibo Observatory after one of the main cables holding the receiver broke in Arecibo, Puerto Rico

At 8 a.m. on 1 December, the Arecibo telescope’s instrument platform crashed into the dish below, tearing more gashes into an already damaged structure.Credit: Ricardo Arduengo/AFP via Getty

At 8 a.m. on 1 December, the Arecibo telescope’s instrument platform crashed into the dish below, tearing more gashes into an already damaged structure. No one was injured, even though the director of telescope operations, Ángel Vázquez, was near the control room at the time of the crash, clearing out valuable items in anticipation of another cable failure. Engineers captured the full extent of the collapse on a drone that was surveying the damage. Watch the heart-stopping footage and read first-hand accounts of the disaster. (Nature | 4 min read)

Quote of the day

"We are now experiencing a La Niña, which has a cooling effect on global temperatures, but has not been sufficient to put a brake on this year's heat."

Petteri Taalas, secretary-general of the World Meteorological Organization, explains that 2020 will be one of the three hottest years on record, and the situation is even worse than it sounds. (BBC | 6 min read)