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Red-toothed mammal from Transylvania ate insects
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Thierry smith
SMALL, with oversized blood-red incisors, and down the road from Dracula’s lair to boot. To coincide with Halloween, we bring you Barbatodon transylvanicus, a 70-million-yearold mammal that scurried beneath the feet of dinosaurs. The discovery of a new skull, complete with teeth, gives the first clues to its diet. Barbatodon lived in what is now Transylvania, Romania, about 200 kilometres from the castle of the bloodthirsty medieval prince Vlad Dracula. It was roughly the size of a rat and belonged to a little-known group of mammals called multituberculates that outlived the dinosaurs, then died out 35 million years ago. Thierry Smith of the Royal Belgian Institute of Natural Sciences in Brussels and Vlad Codrea of the University of Babes-Bolyai in Romania, who found the fossil, shown below, say that its red tooth enamel is 3 per cent iron, which probably made it more resistant to abrasion. Smith presented the findings at the Society of Vertebrate Paleontology meeting in Raleigh, North Carolina, last month. So what did the diminutive mammal eat? In the new fossil, its teeth look most like those of some modern-day shrews. That suggests it may have been partial to a meal of insects. Not so much bloodsucker, then, as insect crusher. 2mm
Golden solution for cheaper diagnostic tests GOLD is synonymous with extravagance, but it could also be key to making medical tests cheaper – and more sensitive. That should allow more people in developing countries to be tested for infections such as HIV. Many diagnostic tests rely on the ELISA technique to detect viruses or tumour cells in blood serum. The equipment to process the results is expensive, so Molly Stevens at Imperial College London and colleagues revamped the test to give a visible result. Their test exploits the ability
of hydrogen peroxide to react with dissolved gold ions, forming metallic nanoparticles. If the peroxide is present in small amounts, the gold slowly forms irregular clumps that turn a solution blue. More peroxide favours fast growth of spherical nanoparticles, which turn it red. The team coated a dish with antibodies that attach to a target molecule on a virus or tumour cell. The sample is added, followed by a second set of antibodies carrying catalase – an enzyme that breaks down hydrogen peroxide – and
the dish is rinsed. Then peroxide is added, followed by gold ions. If the target is present, the fixed layer of antibodies binds to it and the second set binds to that. Rinsing does not remove them, so catalase destroys the peroxide, the gold clumps form slowly and the dish turns blue. If the target is not present, peroxide remains abundant and the dish turns red. In this way, Stevens’ team was able to detect HIV by sight at levels too low for current tests to pick up (Nature Nanotechnology, DOI: 10.1038/nnano.2012.186). nasa-jpl
Red in tooth, lives in Transylvania
Copycat Tourette’s makes people tic FOR the first time, one of the tics that bedevil people with Tourette’s has been induced in volunteers who don’t have the disorder themselves. Jennifer Finis of Heinrich Heine University in Düsseldorf, Germany, and her colleagues suspected that a type of Tourette’s tic, which involves mimicking other’s movements, may be caused by over-stimulation of the SMA, the supplementary motor area in the brain, a region involved in the initiation of movement. To find out, her team used repetitive transcranial magnetic stimulation (rTMS) to deliver brief magnetic pulses to the SMA of 30 volunteers. Thirty seconds before and after rTMS, the volunteers were shown video clips of someone making a spontaneous movement. Those who had had their SMA stimulated were three times as likely to imitate the kind of behaviour they saw in the clips than those who had had the area suppressed (Cortex, doi.org/jmj). The team is now planning to study whether inhibiting the SMA using rTMS may help reduce symptoms in people with Tourette’s.
Stars trapped in dark matter haloes DARK matter may hold clues to a mysterious excess of light in the universe – thanks to the outcast stars it seems to harbour. Galaxies are thought to be wrapped in haloes of dark matter that extend far beyond the galaxies’ visible mass. When they collide, some stars get ripped out by gravitational forces, creating trailers of light called tidal tails (see impression, above). While most of these stars sink back into the merged galaxy, a few may become trapped in dark matter haloes. Such stars haven’t been found yet. But a new sky map made
with NASA’s Spitzer Space Telescope shows that the model is a good fit for otherwise unexplained splotches of light in the cosmic infrared background, a haze of light thought to be the collective glow of all the stars and galaxies that have ever existed (Nature, doi.org/jmd). More work is needed to confirm the idea, says NASA’s Edward Wright. The new research looked at a larger area of sky than ever before, but Spitzer’s sensitivity is limited. When the James Webb Space Telescope is completed in 2018, its advanced infrared eye should give more details.
3 November 2012 | NewScientist | 17
Thierry smith
SMALL, with oversized blood-red incisors, and down the road from Dracula’s lair to boot. To coincide with Halloween, we bring you Barbatodon transylvanicus, a 70-million-yearold mammal that scurried beneath the feet of dinosaurs. The discovery of a new skull, complete with teeth, gives the first clues to its diet. Barbatodon lived in what is now Transylvania, Romania, about 200 kilometres from the castle of the bloodthirsty medieval prince Vlad Dracula. It was roughly the size of a rat and belonged to a little-known group of mammals called multituberculates that outlived the dinosaurs, then died out 35 million years ago. Thierry Smith of the Royal Belgian Institute of Natural Sciences in Brussels and Vlad Codrea of the University of Babes-Bolyai in Romania, who found the fossil, shown below, say that its red tooth enamel is 3 per cent iron, which probably made it more resistant to abrasion. Smith presented the findings at the Society of Vertebrate Paleontology meeting in Raleigh, North Carolina, last month. So what did the diminutive mammal eat? In the new fossil, its teeth look most like those of some modern-day shrews. That suggests it may have been partial to a meal of insects. Not so much bloodsucker, then, as insect crusher. 2mm
Golden solution for cheaper diagnostic tests GOLD is synonymous with extravagance, but it could also be key to making medical tests cheaper – and more sensitive. That should allow more people in developing countries to be tested for infections such as HIV. Many diagnostic tests rely on the ELISA technique to detect viruses or tumour cells in blood serum. The equipment to process the results is expensive, so Molly Stevens at Imperial College London and colleagues revamped the test to give a visible result. Their test exploits the ability
of hydrogen peroxide to react with dissolved gold ions, forming metallic nanoparticles. If the peroxide is present in small amounts, the gold slowly forms irregular clumps that turn a solution blue. More peroxide favours fast growth of spherical nanoparticles, which turn it red. The team coated a dish with antibodies that attach to a target molecule on a virus or tumour cell. The sample is added, followed by a second set of antibodies carrying catalase – an enzyme that breaks down hydrogen peroxide – and
the dish is rinsed. Then peroxide is added, followed by gold ions. If the target is present, the fixed layer of antibodies binds to it and the second set binds to that. Rinsing does not remove them, so catalase destroys the peroxide, the gold clumps form slowly and the dish turns blue. If the target is not present, peroxide remains abundant and the dish turns red. In this way, Stevens’ team was able to detect HIV by sight at levels too low for current tests to pick up (Nature Nanotechnology, DOI: 10.1038/nnano.2012.186). nasa-jpl
Red in tooth, lives in Transylvania
Copycat Tourette’s makes people tic FOR the first time, one of the tics that bedevil people with Tourette’s has been induced in volunteers who don’t have the disorder themselves. Jennifer Finis of Heinrich Heine University in Düsseldorf, Germany, and her colleagues suspected that a type of Tourette’s tic, which involves mimicking other’s movements, may be caused by over-stimulation of the SMA, the supplementary motor area in the brain, a region involved in the initiation of movement. To find out, her team used repetitive transcranial magnetic stimulation (rTMS) to deliver brief magnetic pulses to the SMA of 30 volunteers. Thirty seconds before and after rTMS, the volunteers were shown video clips of someone making a spontaneous movement. Those who had had their SMA stimulated were three times as likely to imitate the kind of behaviour they saw in the clips than those who had had the area suppressed (Cortex, doi.org/jmj). The team is now planning to study whether inhibiting the SMA using rTMS may help reduce symptoms in people with Tourette’s.
Stars trapped in dark matter haloes DARK matter may hold clues to a mysterious excess of light in the universe – thanks to the outcast stars it seems to harbour. Galaxies are thought to be wrapped in haloes of dark matter that extend far beyond the galaxies’ visible mass. When they collide, some stars get ripped out by gravitational forces, creating trailers of light called tidal tails (see impression, above). While most of these stars sink back into the merged galaxy, a few may become trapped in dark matter haloes. Such stars haven’t been found yet. But a new sky map made
with NASA’s Spitzer Space Telescope shows that the model is a good fit for otherwise unexplained splotches of light in the cosmic infrared background, a haze of light thought to be the collective glow of all the stars and galaxies that have ever existed (Nature, doi.org/jmd). More work is needed to confirm the idea, says NASA’s Edward Wright. The new research looked at a larger area of sky than ever before, but Spitzer’s sensitivity is limited. When the James Webb Space Telescope is completed in 2018, its advanced infrared eye should give more details.
3 November 2012 | NewScientist | 17