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Space bullets could have formed Earth's iron core
X-ray: NASA/CXC/SAO; Infrared: NASA/JPL-Caltech; Optical: MPIA, Calar Alto, O. Krause et al.
in Brief Smarter fish aren’t dish of the day
Space bullets could have formed Earth’s iron core CANNONBALL! The iron in Earth’s core may be from giant iron bullets fired off by stars when they die. Stars fuse the hydrogen and helium present in the early universe into heavier elements such as iron. When they die, stars explode in supernovae, leaving behind a cloud of ejected material called a supernova remnant. A particular kind of supernova called a type Ia, the result of a white dwarf star exploding, is responsible for most of the iron on Earth – but we still don’t know what makes them blow up. Now Noam Soker at the Technion-Israel Institute of
Technology in Haifa and his colleague Danny Tsebrenko think they have a clue. The supernova remnants should be spherical, but some have bumps. The pair think clumps of iron produced within a white dwarf going supernova could punch through the remnant like bullets, creating these bumps. In their model, the bullets – clouds of molecules rather than solid chunks – only form when the white dwarf is the result of two smaller dwarfs merging (arxiv.org/ abs/1505.02034v1). The diffuse bullets could also be responsible for Earth’s origins. They would be several times the mass of Jupiter and, as they spread, could eventually seed dust clouds with iron that would go on to form stars and planets, including Earth’s core.
Young blood heals old fractured bones YOUNG blood has once again shown its promise as an elixir of youth: blood from young mice helps bones of older animals heal. In 2012, researchers reversed some of the effects of cognitive decline by pumping the blood of young mice into old mice. The results were so intriguing that a team at Stanford University began the ultimate rejuvenation trial: giving blood plasma from under 16 | NewScientist | 23 May 2015
30s to people with Alzheimer’s. Results are expected next year. To see if young blood could also help ageing bones, Benjamin Alman at the Hospital for Sick Children in Toronto, Canada, surgically joined the circulatory systems of mice of various ages. Fractured shin bones of old mice healed faster and better when the rodents were joined to young mice than to mice their own age.
Older bones have higher levels of a protein called beta-catenin. This makes bone marrow stem cells more likely to form cells that hold bone together than cells that make bone itself. Beta-catenin levels were much lower in old mice that had received young blood, suggesting that a molecule present lowers beta-catenin and promotes bone growth. “We’re honing in on that molecule,” says Alman (Nature Communications, DOI: 10.1038/ncomms8131).
“AS CLEVER as a guppy” is not a huge compliment. But intelligence does matter to the tropical fish, as big-brained guppies outwit predators to live longer than slower witted peers. Alexander Kotrschal at Stockholm University, Sweden, and his colleagues bred guppies (Poecilia reticulata) to have brains that were bigger or smaller than average. His team previously showed that bigger brains meant smarter fish. Big-brained females were eaten about 13 per cent less often than small-brained ones though there was no such link in males, whose bright colours may counter any benefits of higher intelligence (Ecology Letters, doi.org/4p9). “This is exciting because it confirms a critical mechanism for brain size evolution,” says Kotrschal. It shows, he adds, that interactions between predator and prey can affect the brain size.
Brains respond uniquely to words WATCH your language. Words mean different things to different people – so the brainwaves they provoke can identify you. Blair Armstrong of the Basque Center on Cognition, Brain and Language in Spain and his team recorded the brain signals of 45 volunteers as they read a list of acronyms, then used computer programs to spot differences between individuals. The responses varied enough that the programs could identify the volunteers with about 94 per cent accuracy when the experiment was repeated (Neurocomputing, DOI: 10.1016/ j.neucom.2015.04.025). Armstrong hopes this could be developed into an alternative to fingerprint recognition systems.
in Brief Smarter fish aren’t dish of the day
Space bullets could have formed Earth’s iron core CANNONBALL! The iron in Earth’s core may be from giant iron bullets fired off by stars when they die. Stars fuse the hydrogen and helium present in the early universe into heavier elements such as iron. When they die, stars explode in supernovae, leaving behind a cloud of ejected material called a supernova remnant. A particular kind of supernova called a type Ia, the result of a white dwarf star exploding, is responsible for most of the iron on Earth – but we still don’t know what makes them blow up. Now Noam Soker at the Technion-Israel Institute of
Technology in Haifa and his colleague Danny Tsebrenko think they have a clue. The supernova remnants should be spherical, but some have bumps. The pair think clumps of iron produced within a white dwarf going supernova could punch through the remnant like bullets, creating these bumps. In their model, the bullets – clouds of molecules rather than solid chunks – only form when the white dwarf is the result of two smaller dwarfs merging (arxiv.org/ abs/1505.02034v1). The diffuse bullets could also be responsible for Earth’s origins. They would be several times the mass of Jupiter and, as they spread, could eventually seed dust clouds with iron that would go on to form stars and planets, including Earth’s core.
Young blood heals old fractured bones YOUNG blood has once again shown its promise as an elixir of youth: blood from young mice helps bones of older animals heal. In 2012, researchers reversed some of the effects of cognitive decline by pumping the blood of young mice into old mice. The results were so intriguing that a team at Stanford University began the ultimate rejuvenation trial: giving blood plasma from under 16 | NewScientist | 23 May 2015
30s to people with Alzheimer’s. Results are expected next year. To see if young blood could also help ageing bones, Benjamin Alman at the Hospital for Sick Children in Toronto, Canada, surgically joined the circulatory systems of mice of various ages. Fractured shin bones of old mice healed faster and better when the rodents were joined to young mice than to mice their own age.
Older bones have higher levels of a protein called beta-catenin. This makes bone marrow stem cells more likely to form cells that hold bone together than cells that make bone itself. Beta-catenin levels were much lower in old mice that had received young blood, suggesting that a molecule present lowers beta-catenin and promotes bone growth. “We’re honing in on that molecule,” says Alman (Nature Communications, DOI: 10.1038/ncomms8131).
“AS CLEVER as a guppy” is not a huge compliment. But intelligence does matter to the tropical fish, as big-brained guppies outwit predators to live longer than slower witted peers. Alexander Kotrschal at Stockholm University, Sweden, and his colleagues bred guppies (Poecilia reticulata) to have brains that were bigger or smaller than average. His team previously showed that bigger brains meant smarter fish. Big-brained females were eaten about 13 per cent less often than small-brained ones though there was no such link in males, whose bright colours may counter any benefits of higher intelligence (Ecology Letters, doi.org/4p9). “This is exciting because it confirms a critical mechanism for brain size evolution,” says Kotrschal. It shows, he adds, that interactions between predator and prey can affect the brain size.
Brains respond uniquely to words WATCH your language. Words mean different things to different people – so the brainwaves they provoke can identify you. Blair Armstrong of the Basque Center on Cognition, Brain and Language in Spain and his team recorded the brain signals of 45 volunteers as they read a list of acronyms, then used computer programs to spot differences between individuals. The responses varied enough that the programs could identify the volunteers with about 94 per cent accuracy when the experiment was repeated (Neurocomputing, DOI: 10.1016/ j.neucom.2015.04.025). Armstrong hopes this could be developed into an alternative to fingerprint recognition systems.