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Blood test could diagnose teen depression
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IN BRIEF Dinosaur hobbled with painful joints
Ocean’s toxic alkalisation made animal life flower HOW ironic. Concerns abound about the acidification of oceans due to climate change. Meanwhile, researchers have found evidence that the reverse – a massive and toxic alkalisation of the oceans hundreds of millions of years ago – paradoxically made animal life flower. Complex animals first appeared 850 million years ago but didn’t evolve into a great variety of forms until the Cambrian period, 540 million years ago. Why the delay? Answering this is difficult, in part because rocks that formed immediately before the Cambrian appear to have vanished. Cambrian rocks often sit on much older layers,
creating the Great Unconformity – a geological formation seen around the world, including in the Grand Canyon. Shanan Peters of the University of Wisconsin-Madison and Robert Gaines of Pomona College in Claremont, California, now suggest this crucial rock record may have dissolved into the ocean. The pair examined Cambrian rocks and found chemical evidence that the oceans at the time were rich in minerals from weathered rock that would have turned them alkaline (Nature, DOI: 10.1038/ nature10969). What triggered this erosion, which lasted tens of millions of years, is not known. The result was toxic. To survive, the animals developed ways of pumping calcium out of their bodies, which would have formed outer crusts – the first shells, which would later turn into bones. The rest is history.
Hand paralysis reversed in monkeys EAVESDROPPING on the brains of monkeys with hand paralysis has helped restore near-normal function. The system could one day be trialled in people, too. Currently available systems restore only basic hand control to those with damage to the spinal nerves that control the arms. Now Lee Miller and his colleagues at Northwestern University, Chicago, think it is possible to fine-tune 16 | NewScientist | 21 April 2012
this control. They inserted 100 electrodes into the brains of two healthy monkeys to record the neural activity linked to different hand and arm muscle activity. They then used an anaesthetic to paralyse the monkeys’ wrist and hand muscles. By comparing subsequent brain activity with that recorded before paralysis, the team could predict the movement each monkey was attempting, and
electronically trigger muscles in the monkey’s hand to replicate the expected action. The animals regained enough control to successfully place a ball into a tube in 80 per cent of attempts (Nature, DOI: 10.1038/nature10987). Chet Moritz at the University of Washington in Seattle developed a similar system in 2008. He says the new results represent only a minor advance, but Miller counters that the new system uses more brain electrodes, allowing better control.
NOT all dinosaurs roamed the world: one may have hobbled. Caudipteryx, a dino-bird that lived 130 million years ago, was prone to osteoarthritis – perhaps the oldest such diagnosis on record. Some modern birds are prone to osteoarthritis, the degeneration of bone and cartilage in joints. Curious about when the condition first appeared, Bruce Rothschild at the University of Kansas in Lawrence and colleagues examined the fossilised ankle bones of ancient birds and feathered dinosaurs held in Chinese museums. Three of the 10 available fossils of Caudipteryx showed signs of osteoarthritis (Cretaceous Research, DOI: 10.1016/j.cretres.2011.12.008). Why Caudipteryx, which was the size of a peacock, should have been prone to the condition is a mystery: osteoarthritis is most common in smaller birds today, says Rothschild.
Blood test for teen depression DIAGNOSING depression may get a little easier, thanks to the first blood test that can identify depression in teenagers. Depression is hard to diagnose in teens due to healthy hormonal changes. To change that, Eva Redei at Northwestern University in Illinois and colleagues first worked out which genes are involved in the condition by comparing gene expression in rats with depression to that in normal rats. They then analysed the expression of 52 of these genes in blood samples from 28 teenagers, half of whom had depression. Abnormal levels of expression for 11 of the genes were found to be associated with the condition (Translational Psychiatry, DOI: 10.1038/tp.2012.26).
IN BRIEF Dinosaur hobbled with painful joints
Ocean’s toxic alkalisation made animal life flower HOW ironic. Concerns abound about the acidification of oceans due to climate change. Meanwhile, researchers have found evidence that the reverse – a massive and toxic alkalisation of the oceans hundreds of millions of years ago – paradoxically made animal life flower. Complex animals first appeared 850 million years ago but didn’t evolve into a great variety of forms until the Cambrian period, 540 million years ago. Why the delay? Answering this is difficult, in part because rocks that formed immediately before the Cambrian appear to have vanished. Cambrian rocks often sit on much older layers,
creating the Great Unconformity – a geological formation seen around the world, including in the Grand Canyon. Shanan Peters of the University of Wisconsin-Madison and Robert Gaines of Pomona College in Claremont, California, now suggest this crucial rock record may have dissolved into the ocean. The pair examined Cambrian rocks and found chemical evidence that the oceans at the time were rich in minerals from weathered rock that would have turned them alkaline (Nature, DOI: 10.1038/ nature10969). What triggered this erosion, which lasted tens of millions of years, is not known. The result was toxic. To survive, the animals developed ways of pumping calcium out of their bodies, which would have formed outer crusts – the first shells, which would later turn into bones. The rest is history.
Hand paralysis reversed in monkeys EAVESDROPPING on the brains of monkeys with hand paralysis has helped restore near-normal function. The system could one day be trialled in people, too. Currently available systems restore only basic hand control to those with damage to the spinal nerves that control the arms. Now Lee Miller and his colleagues at Northwestern University, Chicago, think it is possible to fine-tune 16 | NewScientist | 21 April 2012
this control. They inserted 100 electrodes into the brains of two healthy monkeys to record the neural activity linked to different hand and arm muscle activity. They then used an anaesthetic to paralyse the monkeys’ wrist and hand muscles. By comparing subsequent brain activity with that recorded before paralysis, the team could predict the movement each monkey was attempting, and
electronically trigger muscles in the monkey’s hand to replicate the expected action. The animals regained enough control to successfully place a ball into a tube in 80 per cent of attempts (Nature, DOI: 10.1038/nature10987). Chet Moritz at the University of Washington in Seattle developed a similar system in 2008. He says the new results represent only a minor advance, but Miller counters that the new system uses more brain electrodes, allowing better control.
NOT all dinosaurs roamed the world: one may have hobbled. Caudipteryx, a dino-bird that lived 130 million years ago, was prone to osteoarthritis – perhaps the oldest such diagnosis on record. Some modern birds are prone to osteoarthritis, the degeneration of bone and cartilage in joints. Curious about when the condition first appeared, Bruce Rothschild at the University of Kansas in Lawrence and colleagues examined the fossilised ankle bones of ancient birds and feathered dinosaurs held in Chinese museums. Three of the 10 available fossils of Caudipteryx showed signs of osteoarthritis (Cretaceous Research, DOI: 10.1016/j.cretres.2011.12.008). Why Caudipteryx, which was the size of a peacock, should have been prone to the condition is a mystery: osteoarthritis is most common in smaller birds today, says Rothschild.
Blood test for teen depression DIAGNOSING depression may get a little easier, thanks to the first blood test that can identify depression in teenagers. Depression is hard to diagnose in teens due to healthy hormonal changes. To change that, Eva Redei at Northwestern University in Illinois and colleagues first worked out which genes are involved in the condition by comparing gene expression in rats with depression to that in normal rats. They then analysed the expression of 52 of these genes in blood samples from 28 teenagers, half of whom had depression. Abnormal levels of expression for 11 of the genes were found to be associated with the condition (Translational Psychiatry, DOI: 10.1038/tp.2012.26).