LEAD often gets a bad press. But its discovery in ancient Graeco-Roman ink could make it easier to read an early form of publishing – precious scrolls buried by the eruption of Mount Vesuvius in AD 79. Some 800 scrolls, part of the classical world’s best-surviving library, have tantalised scholars since they were unearthed in a villa in the ancient Roman city of Herculaneum in 1752. About 200 are in such a delicate state that they have never been read. Unrolling the charred scrolls could destroy them, so people have been X-raying the bundles in the hopes of decoding the writing inside. But progress has been slow – it is difficult to detect the difference between the letters and the papyrus they are written on. Now physicist Vito Mocella of the Italian National Research Council and his colleagues have discovered lead in the ink on two Herculaneum papyri fragments held in the Institute of France in Paris. The presence of lead means that imaging techniques could be recalibrated to pick up the metal, something X-rays excel at (PNAS, doi.org/bdn5). “This really opens up the possibility of being able to read these scrolls,” says Graham Davis, at Queen Mary University of London. “If this is typical of this scroll or other scrolls, than that is very good news.”
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Violent pirouette spun off the moon’s water BALLET doesn’t suit everyone. Molten rock flowing beneath the moon’s crust billions of years ago shifted its spin axis by about six degrees. The pirouette could have cost the moon most of its water. We saw the first direct evidence of water on the moon in 2009, when a deliberately crashed satellite found hydrogen – a proxy for water – in a southern crater. There was more there than at the actual pole, a little more than five degrees away, says Matthew Siegler of the Planetary Science Institute in Tucson, Arizona.
While scrutinising maps of the lunar composition, Siegler noticed that the highest concentration of hydrogen at the north pole is also a few degrees away from the true pole, but in the opposite direction. “They are on exact opposite sides of the moon from each other. It’s as if you drew a line through the centre of the moon from those two points,” he says. This indicates that the moon’s polar axis used to follow that line, but shifted. Based on its direction, Siegler and his colleagues think
the shift was caused when lava flowing up from the lunar interior formed the Procellarum region. The volcanism would have changed the distribution of the moon’s mass, spinning it around (Nature, doi.org/bdn9). That pirouette could have cost the moon much of its water. When the poles shifted, frozen water would have been exposed to the sun and evaporated. That helps to explain why the moon is so dry, and suggests that much of the lunar water is leftover from early in its life. Natalie Shuttleworth/Getty
Leaded ink opens up ancient scrolls
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Fungi may help woodpeckers drill IF A red-cockaded woodpecker wants a home, it does more than just knock on wood – it takes some tiny helpers with it. It seems to carry spores of wood-rotting fungi to each new hole. Red-cockaded woodpeckers live in the pine forests of the south-eastern US, where they dig tree cavities to live in. Each family has cavities at different stages of construction. It’s no quick bodge job – a hole can take years to craft. Michelle Jusino of the US Forest Service Center for Forest Mycology Research in Wisconsin and her colleagues have found a wide range of fungal spores on the birds, including many that cause wood decay and are found in cavities that woodpeckers dig. To see whether the birds bring the fungi to the cavities, the team drilled holes in 60 trees, covering half with screens the woodpeckers can’t get through. After 26 months, accessible holes had fungal communities that were more similar to those found in natural woodpecker cavities than to inaccessible holes. This suggests the birds do disperse fungi, although any benefit to them is still unproven (Proceedings of the Royal Society B, doi.org/bdn7).
Parasites, mew give me road rage CATS can make us angry. Scratching our furniture, waking us up – and giving us parasites that may cause explosive rage. Toxoplasma gondii is a parasite carried by cats that lives in the brains of as many as a third of all people worldwide. Now the parasite has been linked to a psychiatric condition involving disproportionate outbursts of aggression, like road rage. Emil Coccaro at the University of Chicago and his colleagues compared 110 people with intermittent explosive disorder (IED) with people who have no psychiatric diagnosis.
They found that people with IED were more than twice as likely to test positive for exposure to T. gondii. In both groups, those who tested positive tended to rank more highly in tests for aggression (Journal of Clinical Psychiatry, doi.org/bdpq). Coccaro thinks the parasite may be altering neurotransmitters in the brain. However, the correlation doesn’t necessarily mean that T. gondii is causing the explosive rage. Aggressive people may be less likely to wash their hands, making them more likely to catch the parasite, for example.