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Moving helps kids with ADHD focus
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Polar bears devour Wind turbines with owl wings could make energy silently lost dolphins MOVING silently through the air inspiration. Evenly spaced bristles When the team tested the wings
Samuel Blanc/sblanc.com
isn’t just for birds. Wind turbines inspired by the stealthy flight of owls could generate more energy than existing ones, without annoying those who live nearby. Turbines create emissions-free electricity by using the wind to turn propeller-like blades around a rotor. But nearby wildlife and people prefer they keep quiet. Now Nigel Peake of the University of Cambridge and his colleagues have turned to owls – famously silent predators thanks to sound-dampening wings – for
along the wings’ width break up sound waves as an owl flies, preventing them from building up and producing noise. “These features are absolutely unique to owls,” says Peake. The team made its own owl wings by taking an aerofoil and adding a number of fins that trail across and off the edge of the surface. The fins replicate the owl’s evenly spaced bristles, disrupting surface pressure on the aerofoil and reducing the sound waves it produces.
in a wind tunnel, they found that noise reduction worked best when the fins were spaced 1 millimetre apart across the aerofoil. The best performing fins cut noise by a factor of 10. The team will present the work at the American Institute of Aeronautics and Astronautics conference in Dallas, Texas, later this month. Many turbines are artificially braked so they don’t make too much noise. With this technology, turbines could run faster without getting louder. Marie Genel/Picturetank
THEY’RE two of the world’s most loved animals – but there’s little love between them. Polar bears have been snapped eating white-beaked dolphins that had ventured too far north. While collecting data in Svalbard, Norway, in late April 2014, Jon Aars of the Norwegian Polar Institute and his team stumbled across a bear with two dead white-beaked dolphins, a species no one had ever seen the bears preying upon before. “We think the bear killed them, [using] a similar technique as killing seals,” says Aars. He thinks it caught the two dolphins when, trapped below the sea ice, they found a small hole and surfaced for air. The bear had already eaten most of the first dolphin but couldn’t finish all of its catch in one sitting. So it made use of the natural freezer, storing a second dolphin – still largely intact – under the snow, presumably for a later snack. Hiding leftovers is rare in polar bears. “We think it caught the second dolphin because it could, and then had extra food later,” says Aars. Subsequently, the team came across at least five other polar bears feeding on dead dolphins in the same area (Polar Research, doi.org/5bx). The dolphins were probably from the same pod, which became trapped among the ice by strong northerly winds.
Clock transplant lets E. coli keep time A CIRCADIAN clock has been inserted in E. coli, allowing it to keep to a 24-hour schedule. Many organisms use circadian clocks to regulate their activities but we don’t know much about bacterial clocks. The best studied belongs to photosynthetic cyanobacteria: other microbes, like E. coli, don’t carry clocks at all, says Pamela Silver at Harvard. The cyanobacteria timekeeper is based on a gene cluster called kaiABC and the molecular fuel ATP. During the day, the KaiA protein makes the KaiC protein bind to part of the ATP molecule. At night, KaiB disrupts the activity of KaiA so KaiC releases the ATP. Silver’s team put this clock into E. coli, tweaking it so the KaiC turned on a fluorescent protein when it bound to ATP. This meant the E.coli gradually became more, and then less, fluorescent over a 24-hour period, confirming it was now running to a schedule (Science Advances, doi.org/5db). Circadian clocks are usually “entrained” by the day-night cycle. E.coli have no light receptors, so their clock will eventually wind down. If the team could keep it going, it could be used in biological computers.
Moving helps kids with ADHD focus CHILDREN with ADHD are more likely to succeed in cognitive tasks when they fidget. Rather than telling them off, would it be better to let them squirm in class? One theory about attention-deficit hyperactivity disorder is that the brain is under-aroused. Physical movements could help wake it up, perhaps by stimulating the release of brain-signalling chemicals. Julie Schweitzer of the University of California, Davis, and her team asked 44 children with ADHD to describe an arrangement of arrows. The children were more likely to
focus on the task and answer correctly if they fidgeted (Child Neuropsychology, doi.org/5b7). “We need to consider that fidgeting is helpful,” says Schweitzer. “We need to find ways that children with ADHD can move without being disruptive to others.” Dustin Sarver at the University of Mississippi in Jackson agrees. “We should revisit the targets we want for these children, such as improving the work they complete rather than sitting still.” Sarver recently found a link between ADHD fidgeting and improved working memory.
20 June 2015 | NewScientist | 19
Polar bears devour Wind turbines with owl wings could make energy silently lost dolphins MOVING silently through the air inspiration. Evenly spaced bristles When the team tested the wings
Samuel Blanc/sblanc.com
isn’t just for birds. Wind turbines inspired by the stealthy flight of owls could generate more energy than existing ones, without annoying those who live nearby. Turbines create emissions-free electricity by using the wind to turn propeller-like blades around a rotor. But nearby wildlife and people prefer they keep quiet. Now Nigel Peake of the University of Cambridge and his colleagues have turned to owls – famously silent predators thanks to sound-dampening wings – for
along the wings’ width break up sound waves as an owl flies, preventing them from building up and producing noise. “These features are absolutely unique to owls,” says Peake. The team made its own owl wings by taking an aerofoil and adding a number of fins that trail across and off the edge of the surface. The fins replicate the owl’s evenly spaced bristles, disrupting surface pressure on the aerofoil and reducing the sound waves it produces.
in a wind tunnel, they found that noise reduction worked best when the fins were spaced 1 millimetre apart across the aerofoil. The best performing fins cut noise by a factor of 10. The team will present the work at the American Institute of Aeronautics and Astronautics conference in Dallas, Texas, later this month. Many turbines are artificially braked so they don’t make too much noise. With this technology, turbines could run faster without getting louder. Marie Genel/Picturetank
THEY’RE two of the world’s most loved animals – but there’s little love between them. Polar bears have been snapped eating white-beaked dolphins that had ventured too far north. While collecting data in Svalbard, Norway, in late April 2014, Jon Aars of the Norwegian Polar Institute and his team stumbled across a bear with two dead white-beaked dolphins, a species no one had ever seen the bears preying upon before. “We think the bear killed them, [using] a similar technique as killing seals,” says Aars. He thinks it caught the two dolphins when, trapped below the sea ice, they found a small hole and surfaced for air. The bear had already eaten most of the first dolphin but couldn’t finish all of its catch in one sitting. So it made use of the natural freezer, storing a second dolphin – still largely intact – under the snow, presumably for a later snack. Hiding leftovers is rare in polar bears. “We think it caught the second dolphin because it could, and then had extra food later,” says Aars. Subsequently, the team came across at least five other polar bears feeding on dead dolphins in the same area (Polar Research, doi.org/5bx). The dolphins were probably from the same pod, which became trapped among the ice by strong northerly winds.
Clock transplant lets E. coli keep time A CIRCADIAN clock has been inserted in E. coli, allowing it to keep to a 24-hour schedule. Many organisms use circadian clocks to regulate their activities but we don’t know much about bacterial clocks. The best studied belongs to photosynthetic cyanobacteria: other microbes, like E. coli, don’t carry clocks at all, says Pamela Silver at Harvard. The cyanobacteria timekeeper is based on a gene cluster called kaiABC and the molecular fuel ATP. During the day, the KaiA protein makes the KaiC protein bind to part of the ATP molecule. At night, KaiB disrupts the activity of KaiA so KaiC releases the ATP. Silver’s team put this clock into E. coli, tweaking it so the KaiC turned on a fluorescent protein when it bound to ATP. This meant the E.coli gradually became more, and then less, fluorescent over a 24-hour period, confirming it was now running to a schedule (Science Advances, doi.org/5db). Circadian clocks are usually “entrained” by the day-night cycle. E.coli have no light receptors, so their clock will eventually wind down. If the team could keep it going, it could be used in biological computers.
Moving helps kids with ADHD focus CHILDREN with ADHD are more likely to succeed in cognitive tasks when they fidget. Rather than telling them off, would it be better to let them squirm in class? One theory about attention-deficit hyperactivity disorder is that the brain is under-aroused. Physical movements could help wake it up, perhaps by stimulating the release of brain-signalling chemicals. Julie Schweitzer of the University of California, Davis, and her team asked 44 children with ADHD to describe an arrangement of arrows. The children were more likely to
focus on the task and answer correctly if they fidgeted (Child Neuropsychology, doi.org/5b7). “We need to consider that fidgeting is helpful,” says Schweitzer. “We need to find ways that children with ADHD can move without being disruptive to others.” Dustin Sarver at the University of Mississippi in Jackson agrees. “We should revisit the targets we want for these children, such as improving the work they complete rather than sitting still.” Sarver recently found a link between ADHD fidgeting and improved working memory.
20 June 2015 | NewScientist | 19