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Our humming brain helps us learn fast
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in Brief Choose what floats with a sound sieve
Bacterial suspects identified in death of Caribbean corals THREE bacteria seem to be responsible for a disease that has killed most of the Caribbean’s reef-building corals. White band disease causes the outer layer of corals to turn white and peel off. Since the 1970s it has swept through the Caribbean’s staghorn and elkhorn corals. Both are now critically endangered. “This disease has taken out the key ecosystem architects,” says David Smith of the University of Essex in Colchester, UK. Now some likely culprits for white band disease have been identified. Michael Sweet of the University of Derby in the UK and colleagues treated diseased corals with
antibiotics and tracked whether they recovered. They also monitored changes in the microorganisms present. This allowed them to find the bacteria thought to trigger the disease. Three bacteria were consistently present in diseased corals, but not healthy ones: Vibrio charchariae – a long-suspected offender, Lactobacillus suebicus and an unidentified species of Bacillus. One or more seems to be responsible for white band disease (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2014.0094). “Getting this smoking gun really provides you with conservation options,” says Smith. It might be possible to identify where the bacteria are coming from and target the site – human activity, such as sewage dumping, may have boosted the bacteria, for example.
Oldest predator fish hailed from China ENTER the hunter. An extinct fish called Megamastax, which prowled the oceans 423 million years ago, is the earliest fish known to be a top predator. The find supports the idea that animals like us, with jaws and backbones, evolved in southern China. It could also help pin down when oxygen in the atmosphere first reached modern levels. Brian Choo, now at Flinders 16 | NewScientist | 21 June 2014
University in Adelaide, Australia, and colleagues studied a lower jaw and part of an upper jaw from south-west China. They say Megamastax was 1 metre long, with a 16-centimetre-long jaw. It had sharp teeth along the front to grip slippery prey and blunt teeth in the back to crush their shells (Scientific Reports, doi.org/s64). “It could have eaten just about anything it wanted,” says Choo.
Megamastax adds to the evidence that jawed vertebrates first evolved in what is now southern China, between 420 and 360 million years ago, before going global. Southern China was the “cradle of life” for jawed vertebrates, says Choo. Megamastax is three times the size of other fish from the time. That suggests the air must have been oxygen-rich 20 million years before we thought. Otherwise, the fish couldn’t have grown so big.
SIEVES made of sound could one day ramp up the power of nanomanufacturing and cell therapy. Ultrasound waves have been used before to levitate and mix small objects or droplets. A team led by Hairong Zheng of the Shenzhen Institutes of Advanced Technology in China has now used sound wave pressure to lift and sort many objects at once. The team etched a thin brass plate and placed it in a tank of water. Ultrasound blasted from above sends acoustic waves through the water that cause the plate to resonate with the surface below. The resulting sound pressure lifts objects placed in the tank according to size and density (Physical Review Applied, doi.org/s68). The team sorted small glass beads from larger ones and glass beads from tin. Zheng says the device could be tuned to sort a range of nano-scale objects.
Our humming brain helps us learn fast OUR ability to learn rapidly may lie in the hum of our brainwaves. The growth of new connections in the brain helps memories form, but this is too slow to explain rapid learning. To see if brainwaves play a role, Earl Miller at MIT observed brain activity in monkeys taught to categorise dots into two groups. At first, they memorised which dots went where, but as the game became harder, they shifted to learning rules behind the game. The team found that, initially, brainwaves of different frequencies were produced in two areas involved in learning. But as the monkeys learned the rules these synced to the same frequency. Miller believes this is a precursor to anatomical changes in brain connections (Neuron, doi.org/s7n).
in Brief Choose what floats with a sound sieve
Bacterial suspects identified in death of Caribbean corals THREE bacteria seem to be responsible for a disease that has killed most of the Caribbean’s reef-building corals. White band disease causes the outer layer of corals to turn white and peel off. Since the 1970s it has swept through the Caribbean’s staghorn and elkhorn corals. Both are now critically endangered. “This disease has taken out the key ecosystem architects,” says David Smith of the University of Essex in Colchester, UK. Now some likely culprits for white band disease have been identified. Michael Sweet of the University of Derby in the UK and colleagues treated diseased corals with
antibiotics and tracked whether they recovered. They also monitored changes in the microorganisms present. This allowed them to find the bacteria thought to trigger the disease. Three bacteria were consistently present in diseased corals, but not healthy ones: Vibrio charchariae – a long-suspected offender, Lactobacillus suebicus and an unidentified species of Bacillus. One or more seems to be responsible for white band disease (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2014.0094). “Getting this smoking gun really provides you with conservation options,” says Smith. It might be possible to identify where the bacteria are coming from and target the site – human activity, such as sewage dumping, may have boosted the bacteria, for example.
Oldest predator fish hailed from China ENTER the hunter. An extinct fish called Megamastax, which prowled the oceans 423 million years ago, is the earliest fish known to be a top predator. The find supports the idea that animals like us, with jaws and backbones, evolved in southern China. It could also help pin down when oxygen in the atmosphere first reached modern levels. Brian Choo, now at Flinders 16 | NewScientist | 21 June 2014
University in Adelaide, Australia, and colleagues studied a lower jaw and part of an upper jaw from south-west China. They say Megamastax was 1 metre long, with a 16-centimetre-long jaw. It had sharp teeth along the front to grip slippery prey and blunt teeth in the back to crush their shells (Scientific Reports, doi.org/s64). “It could have eaten just about anything it wanted,” says Choo.
Megamastax adds to the evidence that jawed vertebrates first evolved in what is now southern China, between 420 and 360 million years ago, before going global. Southern China was the “cradle of life” for jawed vertebrates, says Choo. Megamastax is three times the size of other fish from the time. That suggests the air must have been oxygen-rich 20 million years before we thought. Otherwise, the fish couldn’t have grown so big.
SIEVES made of sound could one day ramp up the power of nanomanufacturing and cell therapy. Ultrasound waves have been used before to levitate and mix small objects or droplets. A team led by Hairong Zheng of the Shenzhen Institutes of Advanced Technology in China has now used sound wave pressure to lift and sort many objects at once. The team etched a thin brass plate and placed it in a tank of water. Ultrasound blasted from above sends acoustic waves through the water that cause the plate to resonate with the surface below. The resulting sound pressure lifts objects placed in the tank according to size and density (Physical Review Applied, doi.org/s68). The team sorted small glass beads from larger ones and glass beads from tin. Zheng says the device could be tuned to sort a range of nano-scale objects.
Our humming brain helps us learn fast OUR ability to learn rapidly may lie in the hum of our brainwaves. The growth of new connections in the brain helps memories form, but this is too slow to explain rapid learning. To see if brainwaves play a role, Earl Miller at MIT observed brain activity in monkeys taught to categorise dots into two groups. At first, they memorised which dots went where, but as the game became harder, they shifted to learning rules behind the game. The team found that, initially, brainwaves of different frequencies were produced in two areas involved in learning. But as the monkeys learned the rules these synced to the same frequency. Miller believes this is a precursor to anatomical changes in brain connections (Neuron, doi.org/s7n).