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Muscle mimic pulls electricity from wet surface
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Mikael Damkier/Alamy
GOOD news for pushy parents. If you want your child to excel musically, you now have better justification for starting their lessons early. New evidence comes from brain scans of 36 highly skilled musicians, split equally between those who started lessons before and after the age of 7, but who had done a similar amount of training and practice. MRI scans revealed that the white matter in the corpus callosum – the brain region that links the two hemispheres – had more extensive wiring and connectivity in the early starters. The wiring of the late starters was not much different from that of non-musician controls. This makes sense as the corpus callosum aids speed and synchronisation in tasks involving both hands, such as playing musical instruments (Journal of Neuroscience, DOI: 10.1523/jneurosci.3578-12.2013). Christopher Steele of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, says this is the most compelling evidence yet that younger-trained musicians have an advantage because their training coincides with a key period of brain development. At age 7 or 8, the corpus callosum is more receptive than ever to the alterations in connectivity necessary to meet the demands of learning an instrument.
Polymer’s flips wring electricity from wet surface IT’S quite a mover – but only when damp. A polymer that flips over if it absorbs water has been used to wring electricity from a wet surface. The film could one day allow small devices to run on nothing but sweat, and provide power in remote areas where conventional sources are scarce. When a dry polymer absorbs water, its molecular structure changes. In principle, this can be converted into larger-scale motion and thus supply energy. But until now, attempts to devise a material
powered by the difference in chemical potential energy between a wet and a dry region have not yielded useful motion. Now Robert Langer and colleagues at the Massachusetts Institute of Technology have blended two polymers to create a film that mimics structures found in muscle and plant tissues that bend when humidity changes. When placed on a wet surface, the film curves up at its ends, becomes unstable and flips over. The ends quickly dry out but absorb water again, and the
process repeats. By flipping over repeatedly, the film can travel across a suitably moist surface unaided. The team found that a 4-centimetre-long strip could lift a load 380 times its own mass, and move sideways when carrying a load 10 times its mass. To extract energy, Langer’s team added a layer of piezoelectric material, which produces electricity when squeezed. When a piece of this film flipped over, it generated 5.6 nanowatts of power – enough to fuel a microchip in sleep mode (Science, doi.org/j6w). MICHAEL AND PATRICIA fogden/MINDEN/ngs
Start early for musical genius
The genetics of queenly behaviour FIRE ants are a family divided. When setting up a new colony, young queens go one of two ways. Some strike out on their own and remain independent, stockpiling fat reserves and creating workers that kill rival queens. But others prefer the communal life, joining colonies in which multiple queens reign side by side. By sequencing the fire ant genome, Laurent Keller at the University of Lausanne in Switzerland and colleagues discovered that two chromosome regions, social B (SB) and social b (Sb) determine the two types of behaviour. Each is made up of several hundred genes and inherited as SB/SB or SB/Sb pairs (Nature, DOI: 10.1038/nature11832). Keller suggests that a similar inheritance pattern might also be found in other organisms. “If you have two or more very different types of behaviour within a single species, I’d be ready to guess that this is what’s going on,” he says. It means that complex differences in behaviour and physiology can be inherited as a single unit, says an impressed Daniel Kronauer at the Rockefeller University in New York.
Secrets of the scorpion swallower DEEP in the Sonoran desert, a terrifying creature searches for fresh meat – even venomous scorpions are on the menu. Throwing its head back, the animal howls at the moon. This isn’t a horror movie but a day in the life of the southern grasshopper mouse (Onychomys torridus, pictured), North America’s only carnivorous mouse. It may hold the secret to a new kind of painkiller. The venom of Arizona bark scorpions causes pain and respiratory failure in humans. Yet grasshopper mice eat them without pause, even while being stung. To discover their
secret, Ashlee Rowe of Sam Houston State University in Austin, Texas, and colleagues examined how the venom affected the nerve cells of mice. Scorpion venom usually activates a protein called Nav1.7 that makes nerves fire pain signals to the brain. Grasshopper mice have a mutation in protein Nav1.8 that prevents this signal from reaching the brain. Rowe presented the work at a meeting of the Society for Integrative and Comparative Biology last week in San Francisco. The team is looking at how the mutation blocks signals to aid the design of novel painkillers.
19 January 2013 | NewScientist | 17
Mikael Damkier/Alamy
GOOD news for pushy parents. If you want your child to excel musically, you now have better justification for starting their lessons early. New evidence comes from brain scans of 36 highly skilled musicians, split equally between those who started lessons before and after the age of 7, but who had done a similar amount of training and practice. MRI scans revealed that the white matter in the corpus callosum – the brain region that links the two hemispheres – had more extensive wiring and connectivity in the early starters. The wiring of the late starters was not much different from that of non-musician controls. This makes sense as the corpus callosum aids speed and synchronisation in tasks involving both hands, such as playing musical instruments (Journal of Neuroscience, DOI: 10.1523/jneurosci.3578-12.2013). Christopher Steele of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, says this is the most compelling evidence yet that younger-trained musicians have an advantage because their training coincides with a key period of brain development. At age 7 or 8, the corpus callosum is more receptive than ever to the alterations in connectivity necessary to meet the demands of learning an instrument.
Polymer’s flips wring electricity from wet surface IT’S quite a mover – but only when damp. A polymer that flips over if it absorbs water has been used to wring electricity from a wet surface. The film could one day allow small devices to run on nothing but sweat, and provide power in remote areas where conventional sources are scarce. When a dry polymer absorbs water, its molecular structure changes. In principle, this can be converted into larger-scale motion and thus supply energy. But until now, attempts to devise a material
powered by the difference in chemical potential energy between a wet and a dry region have not yielded useful motion. Now Robert Langer and colleagues at the Massachusetts Institute of Technology have blended two polymers to create a film that mimics structures found in muscle and plant tissues that bend when humidity changes. When placed on a wet surface, the film curves up at its ends, becomes unstable and flips over. The ends quickly dry out but absorb water again, and the
process repeats. By flipping over repeatedly, the film can travel across a suitably moist surface unaided. The team found that a 4-centimetre-long strip could lift a load 380 times its own mass, and move sideways when carrying a load 10 times its mass. To extract energy, Langer’s team added a layer of piezoelectric material, which produces electricity when squeezed. When a piece of this film flipped over, it generated 5.6 nanowatts of power – enough to fuel a microchip in sleep mode (Science, doi.org/j6w). MICHAEL AND PATRICIA fogden/MINDEN/ngs
Start early for musical genius
The genetics of queenly behaviour FIRE ants are a family divided. When setting up a new colony, young queens go one of two ways. Some strike out on their own and remain independent, stockpiling fat reserves and creating workers that kill rival queens. But others prefer the communal life, joining colonies in which multiple queens reign side by side. By sequencing the fire ant genome, Laurent Keller at the University of Lausanne in Switzerland and colleagues discovered that two chromosome regions, social B (SB) and social b (Sb) determine the two types of behaviour. Each is made up of several hundred genes and inherited as SB/SB or SB/Sb pairs (Nature, DOI: 10.1038/nature11832). Keller suggests that a similar inheritance pattern might also be found in other organisms. “If you have two or more very different types of behaviour within a single species, I’d be ready to guess that this is what’s going on,” he says. It means that complex differences in behaviour and physiology can be inherited as a single unit, says an impressed Daniel Kronauer at the Rockefeller University in New York.
Secrets of the scorpion swallower DEEP in the Sonoran desert, a terrifying creature searches for fresh meat – even venomous scorpions are on the menu. Throwing its head back, the animal howls at the moon. This isn’t a horror movie but a day in the life of the southern grasshopper mouse (Onychomys torridus, pictured), North America’s only carnivorous mouse. It may hold the secret to a new kind of painkiller. The venom of Arizona bark scorpions causes pain and respiratory failure in humans. Yet grasshopper mice eat them without pause, even while being stung. To discover their
secret, Ashlee Rowe of Sam Houston State University in Austin, Texas, and colleagues examined how the venom affected the nerve cells of mice. Scorpion venom usually activates a protein called Nav1.7 that makes nerves fire pain signals to the brain. Grasshopper mice have a mutation in protein Nav1.8 that prevents this signal from reaching the brain. Rowe presented the work at a meeting of the Society for Integrative and Comparative Biology last week in San Francisco. The team is looking at how the mutation blocks signals to aid the design of novel painkillers.
19 January 2013 | NewScientist | 17