Ross and colleagues have recently reported a major breakthrough for our own species, revealing they were able to introduce human stem cells into early pig embryos, producing embryos for which about one in every 100,000 cells were human. These chimeras -- a term adopted from Greek mythology -- were only allowed to develop for 28 days. Now, at this week's meeting of the American Association for the Advancement of Science in Austin, Texas, the team have announced that they have managed a similar feat with sheep embryos, achieving an even higher ratio of human to animal cells. "About one in 10,000 cells in these sheep embryos are human," said Ross. The team are currently allowed to let the chimeric embryos develop for 28 days, 21 of which are in the sheep. While that might be sufficient to see the development of the missing organ when human cells are eventually combined with the genetically modified embryo, Dr Hiro Nakauchi of Stanford University, who is part of the team, said a longer experiment, perhaps up to 70 days, would be more convincing, although that would require additional permission from institutional review boards.
What is remarkable is that the landscape painting beneath -- probably by a student artist -- is turned 90 degrees. The contour of the hills in the background becomes the crouching woman's back. She takes on the shape and form of the Catalan countryside. Kenneth Brummel, a curator at the Art Gallery of Ontario in Toronto, said that he was "excited" when he first learned what lay underneath the Crouching Woman. "It helps to date the painting and it also helps to determine where the painting was made," he told BBC News. "But it also gives a sense of the artists with whom the painter was engaging. And these insights help us ask new, more interesting and scientifically more accurate questions regarding an artist, their process and how they arrived at the forms that we see on the surface of a painting."
The researchers caught mesopelagic fish at varying depths, then examined their stomachs for microplastics back in the lab. They used a specialized air filter so as not to introduce airborne plastic fibers from the lab environment. The team found a wide array of microplastics in the fish stomachs -- with a whopping 73% of the fish having ingested the pollutants.
Arabica and robusta farms proved equally good for these creatures. "Some birds do better with arabica than robusta, but overall, they're both good for wildlife," she said. The difference is important, because data shows that more farmers in the area have been shifting to robusta in recent years, as prices rise for the variety, which is easier to grow. The researchers counted 106 species of birds on the coffee plantations, including at-risk species, such as the alexandrine parakeet, the breyheaded bulbul and the nilgiri woodpigeon. The findings show that farming is not incompatible with wildlife protection, said Jai Ranganathan, a conservation biologist and senior fellow at the National Center for Ecological Analysis and Synthesis, at the University of California, Santa Barbara, who was not involved in the research.
Separately, CNET reported yesterday that SpaceX's Falcon 9 launch on Saturday will include "[t]he first pair of demonstration satellites for the company's 'Starlink' service." The demonstration launch is confirmed in SpaceX's FCC filings. One SpaceX filing this month mentions that a secondary payload on Saturday's Falcon 9 launch will include "two experimental non-geostationary orbit satellites, Microsat-2a and -2b." Those are the two satellites that SpaceX previously said would be used in its first phase of broadband testing.
Hanno Rein of the University of Toronto in Canada and his colleagues regularly model the motions of planets and exoplanets. "We have all the software ready, and when we saw the launch last week we thought, 'Let's see what happens.' So we ran the [Tesla's] orbit forward for several million years," he says. The Falcon Heavy rocket from SpaceX propelled the car out toward Mars, but the sun's gravity will bring it swinging in again some months from now in an elliptical orbit, so it will repeatedly cross the orbits of Mars, Earth, and Venus until it sustains a fatal accident. The Roadster's first close encounter with Earth will be in 2091 -- the first of many in the millennia to come.
Every deep-space mission that makes course corrections needs to send signals to ground stations on Earth. Those ground stations rely on atomic clocks to measure just how long those signals took to arrive, which allows them to locate the spacecrafts position down to the meter in the vast vacuum. They then send signals back, telling the craft where they are and where to go next. Thats a cumbersome process, and it means any given ground station can support only one spacecraft at a time. The goal of DSAC, according to a NASA fact sheet, is to allow spacecraft to make precise timing measurements onboard a spacecraft, without waiting for information from Earth. A DSAC-equipped spacecraft, according to NASAs statement, could calculate time without waiting for measurements from Earth -- allowing it to make course adjustments or perform precision science experiments without pausing to turn its antennas earthward and waiting for a reply.