- Email: [email protected]
Warmer climate could make succulent meat a memory
For new stories every day, visit www.NewScientist.com/news
MICHAEL BLANN/GETTY
IF YOU like a tasty slab of meat, make sure you place your orders soon. Pork chops will become soggier and paler as the world warms, warn veterinary scientists, and steaks could be dark and smelly. This is because meat quality depends in part on whether animals experience heat stress during transport to the slaughterhouse. Neville Gregory of the Royal Veterinary College in Hatfield, UK, who studies how the temperature at which animals are kept affects the quality of their meat, has looked ahead to meat in a climate-changed world (Food Research International, DOI: 10.1016/j.foodres.2009.05.018). After an animal dies, energy reserves – in the form of glycogen – are broken down into lactic acid, causing the carcass’s pH to fall from 7.0 to 5.5. But the meat of heat-stressed pigs acidifies more quickly. When this happens, muscle proteins fall apart, and as a result so does the meat’s structure. “What you’re left with is meat that resembles soggy white blotting paper,” says Gregory. Steak, on the other hand, is likely to be smellier. Heat-stressed cows run out of glycogen before they die, which darkens their meat, turning it almost black. And glycogen-free beef attracts microbes that break down protein and give off the smell of decay.
Mysterious monopole found at last (in crystals) WE HAVE moved a step closer to finding cosmic monopoles – magnetic poles without their opposite. Two experiments using strange stuff called spin ice have provided the best evidence yet that monopoles really are out there. Nearly 80 years ago, physicist Paul Dirac said it must be possible for magnetic north and south poles to exist separately. But despite decades of searching, not one has been found. Last year, researchers demonstrated that certain states of the crystalline material spin ice would
create monopoles that rove about the crystal (New Scientist, 9 May, p 28). They would be seen as disturbances moving through the spins of atoms within the crystal. Now two separate groups claim to have spotted just that. Tom Fennell and his colleagues at the Laue-Langevin Institute in Grenoble, France, recorded the disturbances when they fired a beam of neutrons at a spin ice crystal to see how it affected the neutrons’ energy (Science, DOI: 10.1126/science.1177582). Meanwhile, Jonathan Morris of
the Helmholtz Centre for Materials and Energy in Berlin, Germany, and his colleagues watched how atoms within the crystals fell into alignment along trails through the lattice. These trails are known as “Dirac strings”, because Dirac predicted that cosmic monopoles would have just such a connection between them (Science, DOI: 10.1126/science.1178868). “To my mind there’s now no question: we have overwhelming evidence that these things are real,” says Steve Bramwell of University College London. JUILET WHITE/GETTY
Warmer climate, worse meat
Carrots are better than sticks WANT cooperation? Try rewarding the helpful rather than punishing wrongdoers. In the public goods game, players choose whether or not to contribute money to a common pool, which is then redistributed equally. As playing groups change after every round, the temptation to freeload – to reap the rewards without contributing anything – often leads to a loss of cooperation. Previous research found this could be overcome if players were able to punish freeloaders. David Rand and colleagues at Harvard University wanted to see if rewarding players had a similar effect. Participants were split into three experimental groups: one had the option of punishing freeloaders, another to reward contributors, while the third could choose to reward or punish. Each volunteer played with the same people every round. Rand found that rewarding people always gave the largest return, but if the players had the choice to punish or reward and chose to reward, they received bigger pay-offs (Science, DOI: 10.1126/science.1177418). “It becomes in one’s self-interest to help the group,” says Rand.
‘Incoming!’ warned the eye NOT just a window to the soul, the eye has a few tricks of its own. Newly discovered eye cells can warn us that an object is coming nearer, and do so without the brain’s help. This ability may have evolved to speed escape from predators. Neurons that fire in response to horizontal and vertical movements had already been found in the retinas of mammals, but the only cells known to be sensitive to approaching objects were in the brain. While investigating mouse eye cells, Botond Roska and his team at the Friedrich Miescher Institute for
Biomedical Research in Basel, Switzerland, noticed that one type behaved unusually in response to movement. Further analysis of this one kind of retinal cell revealed that it fired only when an object approached (Nature Neuroscience, DOI: 10.1038/nn.2389). The researchers suspect that people have similar cells, which alert us to approaching objects faster than our brain cells can. “It’s an alarm system that’s as close to the front end of the organism as possible,” says Roska. “If you left it to the brain to respond, it might be too late.”
12 September 2009 | NewScientist | 17
MICHAEL BLANN/GETTY
IF YOU like a tasty slab of meat, make sure you place your orders soon. Pork chops will become soggier and paler as the world warms, warn veterinary scientists, and steaks could be dark and smelly. This is because meat quality depends in part on whether animals experience heat stress during transport to the slaughterhouse. Neville Gregory of the Royal Veterinary College in Hatfield, UK, who studies how the temperature at which animals are kept affects the quality of their meat, has looked ahead to meat in a climate-changed world (Food Research International, DOI: 10.1016/j.foodres.2009.05.018). After an animal dies, energy reserves – in the form of glycogen – are broken down into lactic acid, causing the carcass’s pH to fall from 7.0 to 5.5. But the meat of heat-stressed pigs acidifies more quickly. When this happens, muscle proteins fall apart, and as a result so does the meat’s structure. “What you’re left with is meat that resembles soggy white blotting paper,” says Gregory. Steak, on the other hand, is likely to be smellier. Heat-stressed cows run out of glycogen before they die, which darkens their meat, turning it almost black. And glycogen-free beef attracts microbes that break down protein and give off the smell of decay.
Mysterious monopole found at last (in crystals) WE HAVE moved a step closer to finding cosmic monopoles – magnetic poles without their opposite. Two experiments using strange stuff called spin ice have provided the best evidence yet that monopoles really are out there. Nearly 80 years ago, physicist Paul Dirac said it must be possible for magnetic north and south poles to exist separately. But despite decades of searching, not one has been found. Last year, researchers demonstrated that certain states of the crystalline material spin ice would
create monopoles that rove about the crystal (New Scientist, 9 May, p 28). They would be seen as disturbances moving through the spins of atoms within the crystal. Now two separate groups claim to have spotted just that. Tom Fennell and his colleagues at the Laue-Langevin Institute in Grenoble, France, recorded the disturbances when they fired a beam of neutrons at a spin ice crystal to see how it affected the neutrons’ energy (Science, DOI: 10.1126/science.1177582). Meanwhile, Jonathan Morris of
the Helmholtz Centre for Materials and Energy in Berlin, Germany, and his colleagues watched how atoms within the crystals fell into alignment along trails through the lattice. These trails are known as “Dirac strings”, because Dirac predicted that cosmic monopoles would have just such a connection between them (Science, DOI: 10.1126/science.1178868). “To my mind there’s now no question: we have overwhelming evidence that these things are real,” says Steve Bramwell of University College London. JUILET WHITE/GETTY
Warmer climate, worse meat
Carrots are better than sticks WANT cooperation? Try rewarding the helpful rather than punishing wrongdoers. In the public goods game, players choose whether or not to contribute money to a common pool, which is then redistributed equally. As playing groups change after every round, the temptation to freeload – to reap the rewards without contributing anything – often leads to a loss of cooperation. Previous research found this could be overcome if players were able to punish freeloaders. David Rand and colleagues at Harvard University wanted to see if rewarding players had a similar effect. Participants were split into three experimental groups: one had the option of punishing freeloaders, another to reward contributors, while the third could choose to reward or punish. Each volunteer played with the same people every round. Rand found that rewarding people always gave the largest return, but if the players had the choice to punish or reward and chose to reward, they received bigger pay-offs (Science, DOI: 10.1126/science.1177418). “It becomes in one’s self-interest to help the group,” says Rand.
‘Incoming!’ warned the eye NOT just a window to the soul, the eye has a few tricks of its own. Newly discovered eye cells can warn us that an object is coming nearer, and do so without the brain’s help. This ability may have evolved to speed escape from predators. Neurons that fire in response to horizontal and vertical movements had already been found in the retinas of mammals, but the only cells known to be sensitive to approaching objects were in the brain. While investigating mouse eye cells, Botond Roska and his team at the Friedrich Miescher Institute for
Biomedical Research in Basel, Switzerland, noticed that one type behaved unusually in response to movement. Further analysis of this one kind of retinal cell revealed that it fired only when an object approached (Nature Neuroscience, DOI: 10.1038/nn.2389). The researchers suspect that people have similar cells, which alert us to approaching objects faster than our brain cells can. “It’s an alarm system that’s as close to the front end of the organism as possible,” says Roska. “If you left it to the brain to respond, it might be too late.”
12 September 2009 | NewScientist | 17