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Researchers from the Chinese Academy of Sciences in Beijing recently reported intriguing new evidence for a possible mouse origin of the Omicron variant. Their paper, posted on the BioRxiv preprint server, was quickly picked up and published a few days later by the Journal of Genetics and Genomics, and defies the prevailing theory which claims that the polymutant spike sequence of Omicron must have evolved under protracted infection in a severely immunocompromised patient.

Their main idea is that a mouse could have somehow been infected with the human virus by “reverse zoonotic transfer,” whereupon the virus evolved all or many of its 45 novel mutations, and then subsequently was transferred back to humans. While this theory might explain why Omicron appears so anomalous when plotted on a phylogenetic tree against the usual suspects, there is one major problem: The mouse homolog of the human ACE2 receptor (hACE2), which the virus typically uses to gain entry into , has little affinity for the standard issue SARS-CoV-2 spike protein.

So little in fact, that in order to study the virus in this preferred research animal, scientists must artificially introduce hACE2 in order to create mice that show any significant respiratory distress upon infection. These are made in several ways, each showing unique tissue tropisms, penetrance and correspondingly different effects. Researchers have conducted knock-in experiments in which the human hACE2 sequence is integrated into the and induced under the control of a number of different promoters. Adenoviruses can also be used to infect cells and create replicating plasmids that propagate the hACE2 code.

Horizon Aeronautics is prototyping an eVTOL hovercycle concept that uses a complex and interesting split-swashplate “Blainjett” variable pitch rotor system that only exposes half of each fan. Very odd, but Horizon says it’s highly efficient.

To understand how this Blainjett propulsion system works – and before anyone asks, no, these guys are no relation to me – you first need to understand how the swashplate and cyclic controls work to distribute thrust as a helicopter’s top rotor spins. Each blade can vary its pitch independently, with the height of the swashplate determining the pitch. With the swashplate sitting flat, pushing the whole thing up and down will change the pitch of all the blades at once.

But with the cyclic control, helicopter pilots are able to tilt the swashplate. Pushing the stick forward, for example, tilts it such that the blades gradually tilt as they spin around, getting flatter as they pass the front of the aircraft, then pitching up to develop more lift as they go around the back. The result is an asymmetry in lift, with more at the back of the disc, and the aircraft pitches forward and accelerates in that direction. The cyclic control can do this in any direction; it’s part of what makes helicopters such dynamic aircraft.

Roughly 13.8 billion years ago, our Universe was born in a massive explosion that gave rise to the first subatomic particles and the laws of physics as we know them.

About 370,000 years later, hydrogen had formed, the building block of stars, which fuse hydrogen and helium in their interiors to create all the heavier elements. While hydrogen remains the most pervasive element in the Universe, it can be difficult to detect individual clouds of hydrogen gas in the interstellar medium (ISM).

This makes it difficult to research the early phases of star formation, which would offer clues about the evolution of galaxies and the cosmos.

Google is bringing Fast Pair to Windows and TVs and more. It’s also planning Wear OS watch unlocks for phones.


Google laid out its plans for a number of new features coming to its ecosystem of devices and operating systems this year, a lot of which is focused on connecting them all or making setup easier. Whether you have an Android phone and an Android TV or a Chrome OS devices and a Wear OS watch, there is a good chance they will start to talk to each other.

Quicker setup of all devices

One of the biggest items Google announced today involves Fast Pair, the quick-connect technology that Google pushed out to phones and headphones a couple of years ago. In the coming weeks and months, Fast Pair will work on more devices and throughout more operating systems.