LIVERMORE, Calif., Feb. 27 (UPI) -- An international team, including U.S. researchers, reports it has definitively measured the spin rate of a super-massive black hole for the first time.
Based on data from two X-ray space observatories, NASA's Nuclear Spectroscopic Telescope Array and the European Space Agency's XMM-Newton, the findings will lead to a better understanding of how black holes and galaxies evolve, the researchers said.
"We can trace matter as it swirls into a black hole using X-rays emitted from regions very close to the black hole," Fiona Harrison, NuSTAR principal investigator at the California Institute of Technology in Pasadena, Calif., said. "The radiation we see is warped and distorted by the motions of particles, and by the black hole's incredibly strong gravity."
Astronomers are interested in measuring the spin rates of black holes in the hearts of galaxies because the formation of super-massive black holes is thought to mirror the formation of the galaxy itself.
"We know that black holes have a strong link to their host galaxy," research team member Bill Craig, an astrophysicist at Lawrence Livermore National Laboratory, said in an LLNL release Wednesday.
"Measuring the spin, one of the few things we can directly measure from a black hole, will give us clues to understanding this fundamental relationship."
The researchers said their results showed the black hole is spinning close to the maximal rate allowed by Albert Einstein's theory of gravity.
Mystery of ancient fish's teeth solved
POCATELLO, Idaho, Feb. 27 (UPI) -- U.S. researchers say they've used CAT scans to make 3-D virtual reconstructions of an ancient shark-like fish's odd spiral-toothed jaw.
Idaho State University researchers said fossils of the 270 million-year-old fish known as Helicoprion have long mystified scientists because, for the most part, the only remains of the fish are its teeth.
The rest of the fish's skeletal system was made of cartilage, which doesn't preserve well, they said.
Up to now it has been difficult to explain how the teeth -- looking something like a circular saw blade -- were positioned in the ancient animal, long assumed to be an early species of shark.
"New CT scans of a unique specimen from Idaho show the spiral of teeth within the jaws of the animal, giving new information on what the animal looked like, how it ate," Idaho State geoscience Professor Leif Tapanila said.
Tapanila and his colleagues said virtual reconstructions of the Helicoprion's jaws clear up the biggest mystery surrounding these teeth.
"We were able to answer where the set of teeth fit in the animal," Tapanila said. "They fit in the back of the mouth, right next to the back joint of the jaw. We were able to refute that it might have been located at the front of the jaw."
The location within the jaw likely created a rolling-back and slicing movement, the researchers said, and Helicoprion likely ate soft-tissued prey such as squid, rather that hunting creatures with hard shells.
Brain-boosting video games urged
MADISON, Wis., Feb. 27 (UPI) -- Neuroscientists should work with video game designers to develop compelling digital games that boost brain function and improve well-being, two researchers say.
Daphne Bavelier of the University of Rochester and Richard J. Davidson of the University of Wisconsin-Madison are urging game creators and brain scientists to work together to develop games that train the brain and produce positive effects on behavior, such as decreasing anxiety, sharpening attention and improving empathy.
Video games have been linked with a number of negative results such as obesity, aggressiveness, antisocial behavior and even addiction.
"At the same time, evidence is mounting that playing games can have a beneficial effects on the brain," Bavelier and Davidson wrote in the journal Nature.
Last year Bavelier and Davidson presided over a meeting at the White House in which neuroscientists met with entertainment media experts to discuss ways of using interactive technology to further understanding of brain functions and provide tools for boosting attention and well-being, a UW Madison release said.
"Gradually, this work will begin to document the burning social question of how technology is having an impact on our brains and our lives, and enable us to make evidence-based choices about the technologies of the future, to produce a new set of tools to cultivate positive habits of mind," the two researchers wrote.
Food-testing circuit could eliminate waste
EINDHOVEN, Netherlands, Feb. 27 (UPI) -- Plastic electronics that can test whether food is safe to eat can greatly reduce food waste worldwide, researchers in the Netherlands say.
Millions of tons of food are thrown away each year because the "sell by" date has passed. However, the listed date is a cautious estimate, which means a lot of edible food is thrown away, scientists at Eindhoven University of Technology said.
Working with European colleagues, they have developed a plastic analog-digital converter circuit that could make in-package food testing possible, they said.
Such circuits could cost less than a penny each, they said, making them economically viable as a food testing aid.
For example, food producers could include an electronic sensor circuit in packaging to monitor the acidity level of the food, the researchers said.
Such sensor circuits could be read with a scanner or with a mobile phone to show the freshness of the food or whether it was defrosted, they said.
"In principle that's all already possible, using standard silicon ICs," Eindhoven researcher Eugenio Cantatore said. "The only problem is they're too expensive. They easily cost 10 cents. And that cost is too much for a 1 euro bag of crisps.
"We're now developing electronic devices that are made from plastic rather than silicon. The advantage is you can easily include these plastic sensors in plastic packaging."
The plastic semiconductor can even be printed on all kinds of flexible surfaces making them cheaper to use, he said, and means sensor circuits costing less than 1 cent are achievable.