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Giant Milky Way bubbles blown by black hole merger
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Randall Thompson/The Lancet
HEART disease is commonly thought to be a modern ailment, but evidence from ancient mummies suggests humans have had heart problems for thousands of years. Randall Thompson at the University of Missouri-Kansas City and colleagues analysed CAT scans of 137 mummies from ancient Egypt, Peru, Utah and the Aleutian Islands in the north Pacific Ocean. The mummies represent human populations dating from 3000 BC to the 20th century. A significant cross-section of mummies, from all cultures and time frames, had calcified plaque in artery walls – most frequently the aorta but also in the neck’s carotid artery (shown in photo) – hinting at atherosclerosis, a major cause of heart attacks (The Lancet, 10.1016/ S0140-6736(13)60598-X). The mummies came from populations of farmers and hunter-gatherers with different lifestyles, say the team. Finding atherosclerosis in a range of premodern humans raises the possibility of a predisposition to the disease, they say. Eric Brunner at University College London, says that people who were mummified were likely to be of a certain status. “Odds on they were high-status individuals,” he says, and therefore had a higher fat, more sedentary lifestyle.
Zapping the brain to boost learning also dulls your wits NOT such a bright idea. Stimulating the brain with electrical signals can sharpen some of your faculties, but seems to dim others at the same time. Roi Cohen Kadosh of the University of Oxford showed people pairs of symbols. Each symbol had a secret numerical value, and volunteers had to state as quickly as possible which one in a pair scored higher. The right answer was then revealed. In this way, over six weeks, Cohen Kadosh could see how well people learned the correct ranking.
Participants also had to indicate which symbol in a pair looked larger. This gauges automaticity – “the skill of doing things without thinking about them, such as reading, driving or mounting stairs”, says Cohen Kadosh. During the tests, transcranial electrical stimulation (TES) was applied to some volunteers via electrodes on the surface of the head. The area of focus was either the posterior parietal cortex – vital for numerical learning – or the dorsolateral prefrontal cortex, vital for automaticity.
Those with a stimulated posterior parietal cortex outperformed the others at the learning task, but did worst on the automaticity task. The reverse was true of the group who had TES to the dorsolateral prefrontal cortex. People having sham treatments had intermediate scores on both skills (Journal of Neuroscience, doi. org/kqm). Cohen Kadosh is now testing ways to give TES without dulling skills, such as stimulating both brain regions at different stages in the training. nasa/gsfc
Mummies with broken hearts
Lowly aspirin fights deadly skin cancer A PILL sitting in many medicine cabinets may protect women against skin cancer. Aspirin, a non-steroidal antiinflammatory drug (NSAID), is known to protect against heart disease and colorectal cancer. Now, data from 59,806 white women in the US supports the idea that it also protects against melanoma, the most dangerous type of skin cancer. Over a 12-year period, incidence of melanoma was 21 per cent lower in women taking high-dose aspirin at least twice a week than in people not taking NSAIDs regularly. In all, 115 of the 15,089 aspirin-takers developed melanoma, compared with 344 of 35,529 people (Cancer, DOI: 10.1002/cncr.27817). A likely explanation is that aspirin dampens inflammation pathways that aggravate the spread of the cancer, says Jean Tang of the Stanford University School of Medicine in Palo Alto, California, who led the study. “These findings need to be followed up to find out if there’s a real effect,” says Hazel Nunn, head of health information at Cancer Research UK. She adds that melanoma is largely preventable by protecting skin from sunburn.
Black hole burp blew galactic bubbles A TINY galaxy that collided with the Milky Way could have spawned two huge bubbles of high-energy particles that now tower over the centre of our galaxy. In 2010, sky maps made by NASA’s Fermi Gamma-ray Space Telescope revealed two lobes of particles billowing out from the heart of the Milky Way, each one stretching for 25,000 light years. What created them has been a mystery. Kelly Holley-Bockelmann from Vanderbilt University in Tennessee and colleagues think that long ago a dwarf galaxy dived into the Milky
Way. After billions of years, the dwarf’s central black hole made it to the galactic core and began a tight gravitational tango with the Milky Way’s supermassive black hole. Forces from their subsequent merger squeezed giant clouds of gas into clusters of new stars. The rest of the gas swirled into the merged black holes, compression heating it until it radiated huge amounts of energy (Monthly Notices of the Royal Astronomical Society, doi.org/kqh). The team says that this energised burp, and winds of superhot gas from the new stars, inflated the bubbles.
16 March 2013 | NewScientist | 17
Randall Thompson/The Lancet
HEART disease is commonly thought to be a modern ailment, but evidence from ancient mummies suggests humans have had heart problems for thousands of years. Randall Thompson at the University of Missouri-Kansas City and colleagues analysed CAT scans of 137 mummies from ancient Egypt, Peru, Utah and the Aleutian Islands in the north Pacific Ocean. The mummies represent human populations dating from 3000 BC to the 20th century. A significant cross-section of mummies, from all cultures and time frames, had calcified plaque in artery walls – most frequently the aorta but also in the neck’s carotid artery (shown in photo) – hinting at atherosclerosis, a major cause of heart attacks (The Lancet, 10.1016/ S0140-6736(13)60598-X). The mummies came from populations of farmers and hunter-gatherers with different lifestyles, say the team. Finding atherosclerosis in a range of premodern humans raises the possibility of a predisposition to the disease, they say. Eric Brunner at University College London, says that people who were mummified were likely to be of a certain status. “Odds on they were high-status individuals,” he says, and therefore had a higher fat, more sedentary lifestyle.
Zapping the brain to boost learning also dulls your wits NOT such a bright idea. Stimulating the brain with electrical signals can sharpen some of your faculties, but seems to dim others at the same time. Roi Cohen Kadosh of the University of Oxford showed people pairs of symbols. Each symbol had a secret numerical value, and volunteers had to state as quickly as possible which one in a pair scored higher. The right answer was then revealed. In this way, over six weeks, Cohen Kadosh could see how well people learned the correct ranking.
Participants also had to indicate which symbol in a pair looked larger. This gauges automaticity – “the skill of doing things without thinking about them, such as reading, driving or mounting stairs”, says Cohen Kadosh. During the tests, transcranial electrical stimulation (TES) was applied to some volunteers via electrodes on the surface of the head. The area of focus was either the posterior parietal cortex – vital for numerical learning – or the dorsolateral prefrontal cortex, vital for automaticity.
Those with a stimulated posterior parietal cortex outperformed the others at the learning task, but did worst on the automaticity task. The reverse was true of the group who had TES to the dorsolateral prefrontal cortex. People having sham treatments had intermediate scores on both skills (Journal of Neuroscience, doi. org/kqm). Cohen Kadosh is now testing ways to give TES without dulling skills, such as stimulating both brain regions at different stages in the training. nasa/gsfc
Mummies with broken hearts
Lowly aspirin fights deadly skin cancer A PILL sitting in many medicine cabinets may protect women against skin cancer. Aspirin, a non-steroidal antiinflammatory drug (NSAID), is known to protect against heart disease and colorectal cancer. Now, data from 59,806 white women in the US supports the idea that it also protects against melanoma, the most dangerous type of skin cancer. Over a 12-year period, incidence of melanoma was 21 per cent lower in women taking high-dose aspirin at least twice a week than in people not taking NSAIDs regularly. In all, 115 of the 15,089 aspirin-takers developed melanoma, compared with 344 of 35,529 people (Cancer, DOI: 10.1002/cncr.27817). A likely explanation is that aspirin dampens inflammation pathways that aggravate the spread of the cancer, says Jean Tang of the Stanford University School of Medicine in Palo Alto, California, who led the study. “These findings need to be followed up to find out if there’s a real effect,” says Hazel Nunn, head of health information at Cancer Research UK. She adds that melanoma is largely preventable by protecting skin from sunburn.
Black hole burp blew galactic bubbles A TINY galaxy that collided with the Milky Way could have spawned two huge bubbles of high-energy particles that now tower over the centre of our galaxy. In 2010, sky maps made by NASA’s Fermi Gamma-ray Space Telescope revealed two lobes of particles billowing out from the heart of the Milky Way, each one stretching for 25,000 light years. What created them has been a mystery. Kelly Holley-Bockelmann from Vanderbilt University in Tennessee and colleagues think that long ago a dwarf galaxy dived into the Milky
Way. After billions of years, the dwarf’s central black hole made it to the galactic core and began a tight gravitational tango with the Milky Way’s supermassive black hole. Forces from their subsequent merger squeezed giant clouds of gas into clusters of new stars. The rest of the gas swirled into the merged black holes, compression heating it until it radiated huge amounts of energy (Monthly Notices of the Royal Astronomical Society, doi.org/kqh). The team says that this energised burp, and winds of superhot gas from the new stars, inflated the bubbles.
16 March 2013 | NewScientist | 17