Editor's Choice: Gravitational waves, human migration, infection and dodging the flu
A round-up from the scientific and technical journals.
Proof Einstein was right on gravity waves
Astronomers peering out into the clear Antarctic sky appear to have found a key missing piece of the puzzle of our universe. Embedded in the background microwave radiation from the Big Bang, they found the signature of gravitational waves, first predicted by Einstein in 1916. The finding also validates an extraordinary model for the birth of the universe known as “inflation”, proposed by physicists Alan Guth and Andrei Linde in the early 1980s. As Guth enthused to MIT news, “The significance of these new findings is enormous. As far as we know, there is nothing other than inflation that can produce these gravity waves.” Researchers at the Harvard-Smithsonian Centre for Astrophysics made their announcement at a press conference at Harvard University on 16 March. COSMOS will publish a more detailed analysis next week.
Counting your chickens
Humanity’s expansion from southeast Asia to the islands that dot the vast Pacific ocean is a remarkable feat of migration and one that can be tracked via the genes of the chickens these early explorers carried with them, new research shows. The descendants of these pioneering birds still peck around on many of these islands today, as evidenced by the DNA markers they carry. They show that while the birds made it as far as Hawaii, New Zealand and Easter Island, they did not make it to South America, suggesting the Polynesians did not either. The report can be found here.
One bacterium’s meat is another’s poison
Researchers have discovered how highly infectious microbes such as the plague bacteria, Yersinia pestis, turn their host’s defenses to their advantage. Invaded mammalian cells produce a chemical called itaconate that stops bacterial growth. These bacteria carry genes that convert the chemical into food. A report here.
Out-running the flu
Vigorous exercise can significantly reduce your chance of developing flu, UK research has shown. An online survey run by the London School of Hygiene and Tropical Medicine found that doing at least two and a half hours a week of vigorous exercise, such as running, fast cycling or competitive sport, was protective against flu. Moderate exercise had no protective effect, the analysis found. If everyone exercised this vigorously, the number of flu cases would fall by 10%. The survey results can be found here.