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16 | NewScientist | 25 January 2014 THE dwarf planet Ceres has been caught spouting water vapour, perhaps from a layer of buried ice or even from slushy volcanoes. “This is the first clear-cut detection of water in the asteroid belt,” says Michael Küppers of the European Space Agency. It backs up indirect signs of water on other asteroids – good news for would-be space miners hoping to use that water as fuel. Ceres is the largest object in the asteroid belt, between the orbits of Mars and Jupiter. It is nearly round, like a planet, earning it the title of dwarf planet alongside Pluto and three other objects beyond the orbit of Neptune. Tantalising hints of water breaking apart above Ceres’s surface had turned up in earlier work. Now ESA’s Herschel spacecraft has spotted Brazilian dolphin born of rapids A NEW species of river dolphin has been found, the first of its kind for a century. Tomas Hrbek of the Federal University of Amazonas in Manaus, Brazil, took DNA from river dolphins in the Araguaia and Tocantins rivers. He found they differed from all other species in Brazil. He calls the species Inia araguaiaensis (PLoS One, DOI: 10.1371/journal.pone.0083623). Its genes suggest that the species formed 2.08 million years ago, when the Araguaia-Tocantins basin was cut off from the rest of the Amazon river system by huge rapids and waterfalls, isolating the dolphins from their fellows. “It’s exciting evidence for a previously unrecognised species within the ancient lineage of Amazon river dolphins,” says Scott Baker of Oregon State University in Newport. “Yet it’s already rare, and its habitat is now fragmented by dams.” Squid zeroes in on prey using hopelessly blurred vision HUMAN hunters would struggle to hit anything if a third of their eyesight was out of focus. But bigfin reef squid rely on blurry vision to catch prey. It is hard to judge distance in open water, as there are no objects to use as comparators. Wen-Sung Chung of the University of Queensland in Brisbane, Australia, noticed that bigfin reef squid (Sepioteuthis lessoniana) bob up and down when they have a prey animal in their sights, and wondered if this might be some kind of rangefinder. When she and colleague Justin Marshall investigated, they found a bulge in the rear of each of the squid’s eyes. REINHARD DIRSCHERL/GETTY IN BRIEF Dwarf planet Ceres has attack of vapours water vapour directly. Herschel also helped the team tie the vapour from Ceres to dark spots on its surface (Nature, DOI: 10.1038/nature12918). That suggests the dwarf planet may have an icy layer beneath its dusty surface, exposed by impacts. Or its heart may be warm enough to make ice volcanoes erupt. We should soon know for sure: NASA’s Dawn spacecraft is due to arrive at Ceres in 2015 for a close-up inspection. This retinal bump keeps a quarter to a third of their visual field out of focus, says Marshall. “Nothing like this has been seen in nature before.” Bobbing up and down would move the image of the prey in and out of the blurry region, he adds, allowing the squid to judge its position. The unfocused image would become increasingly blurred compared with the sharp one as the squid closed in. The researchers calculated that the difference would be greatest when prey animals were exactly within tentacle striking distance. “The animal has a built-in rangefinder tuned to its body size and strike length,” says Marshall (Current Biology, DOI: 10.1016/j.cub.2013.11.058). Very few animals are known to use blurred vision to judge distance, but one jumping spider also does so. MEND your broken heart with plastic. Injecting sticky polymer tags could one day limit tissue damage after heart attacks. Ways to control inflammatory monocytes – immune cells that can damage the body after a heart attack – have been elusive, says Stephen Miller at Northwestern University in Evanston, Illinois. His team found microparticles of the biodegradable polymer PLGA, which is already used for dissolvable sutures, can tag monocytes in mice and remove them from inflamed sites (Science Translational Medicine, doi.org/ q3c). Injecting the tags halved the size of lesions after a heart attack. Mice with other inflammatory diseases, including West Nile virus, also improved after being injected. Bio-tags mend mice after heart attack
