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Mammoth DNA is oldest ever sequenced
Mammoth teeth preserved in eastern Siberian permafrost have produced the oldest DNA on record. The DNA was extracted from tooth specimens that are up to 1.6 million years old. The DNA identifies a new kind of mammoth that gave rise to a later North American species. The research pushes the technology close to its limits. Once an organism dies, its chromosomes shatter into pieces that get shorter over time. Eventually, the DNA strands become so small that — even if they can be extracted — they lose their information content. The mammoth teeth were preserved in the constant cold of permafrost, which slows DNA fragmentation.
Three quantum devices linked in a network
Physicists have taken a major step towards a future quantum version of the Internet by linking three quantum devices in a network. Although the network doesn’t yet have the performance needed for practical applications, it demonstrates a key technique that will enable a quantum Internet to connect nodes over long distances. A quantum Internet would enable ultrasecure communications and unlock scientific applications, such as new types of sensors for gravitational waves.
Reference: arXiv preprint
Vaccine inequality leaves doctors to die in Africa
Rich countries are rolling out vaccine programmes across their populations while unprotected health-care workers in Africa continue to die from COVID-19. Countries in Europe, Asia and the Americas have administered 175 million shots since December, prioritizing health-care staff. Meanwhile, immunizations have yet to begin in sub-Saharan African countries, where several prominent doctors have died from the virus in recent weeks. Uneven vaccine distribution is exacerbating existing health-care inequities. In addition to the moral imperative, closing the gap would bring worldwide benefits through faster economic recovery and by reducing the chance that new variants arise.
Features & opinion
A global warning system for viruses
The Global Immunological Observatory is a pilot project for a system that would test blood samples from all over the world to track potential pandemics. This serological monitoring system would look for the presence of antibodies to hundreds of viruses, spotting any infections that are on the rise. The first stage involves the half-million plasma samples from across the United States. The full roll-out would cost millions and require blood from donors around the world.
The New York Times | 5 min read
The secret to winning at maths
Po-Shen Loh has coached the US International Mathematical Olympiad team to the number-one ranking in the world four times in the last six years. Innovations behind his success in the secondary-school-level competition have included inviting rival international teams to the squad’s training camp, taking improvisation classes to improve his own mathematical skills and reaching out to kids from all backgrounds. Puzzle-loving Loh, who also studies extremal combinatorics (objects such as very large graphs or networks), says his goal as a coach isn’t to win, but to maximize the number of team members he reads about in the newspaper in 20 years.