- Email: [email protected]
A gene that piles on the pounds
in Brief
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
HIDING scars 800 kilometres wide isn’t as tricky as you might think. If you’re a dwarf planet, all you need is the right kind of mud. The absence of such large impact craters on Ceres, a dwarf planet in the asteroid belt between Mars and Jupiter, has been a puzzle since NASA’s Dawn probe arrived there in March 2015. Ceres has witnessed most of the solar system’s evolution and should be pockmarked with at least 10 giant craters. The latest images from Dawn, still in orbit around Ceres, may just explain why we cannot see them. Simone Marchi and his colleagues at the Southwest Research Institute in Boulder, Colorado, used hi-res images from Dawn to create a model of Ceres’s topography. They found depressions hinting at large craters, all surface traces of which had been wiped out (Nature Communications, DOI: 10.1038/ncomms12257). The team suggests that Ceres’s unusual internal composition and evolution are to blame. Beneath the surface, Ceres could be a slushy cocktail of low-viscosity materials such as ice and clay that form a kind of mud. That would allow the outer layer to shift and relax, potentially smoothing out any large craters. The results confirm that Ceres is a long-term resident of the asteroid belt, says Thomas Davison of Imperial College London.
16 | NewScientist | 30 July 2016
Superatoms joined to make molecules with super properties IT’S Lego for advanced chemists. Superatoms have been linked up to make molecules for the first time. These could be the building blocks for advanced magnetic materials and electronics. Chemists began building superatoms when they found that certain arrangements of atoms can behave like scaled-up versions of an atom of a different element. These superatoms pool their electrons into shells around a central core, and since such shells determine the atom’s chemical properties, the superatom takes
on those characteristics. That lets you get features that wouldn’t appear in nature. Now a team led by Xavier Roy at Columbia University in New York has taken the concept a step further by constructing pairs or trios of superatoms – the simplest possible superatom molecules. The team built the core of the superatoms out of six cobalt and eight selenium atoms, then added arms made from a variety of other atoms. These arms are designed to fit together, mimicking a chemical bond at the super-scale
(Nano Letters, doi.org/bmw5). The materials could have uniquely tunable magnetic properties, Roy says. “We’re aiming to make things where the whole is greater than the sum of the parts,” he says. “We’re interested in new types of magnetic material or conductive material. By controlling the coupling between superatoms, we can tailor that.” The team plans to build large assemblages of superatoms with these tailored properties, which could form the basis for new kinds of electronics and sensors. Joël Meunier
Mud facial worked wonders for Ceres
For new stories every day, visit newscientist.com/news
A gene that piles on the pounds IT COULD be in your DNA. A gene variant that raises the risk of obesity by between 30 and 40 per cent is the strongest genetic predictor of body weight found in humans so far. Having just one copy of this variant of the CREBRF gene is linked to an increase in body mass index of 1.5 points. For an 83-kilogram person who is 1.75 metres tall, this is the equivalent of gaining 4.6 kilograms (Nature Genetics, doi.org/bm2t). The variant was uncovered during a genomic analysis of more than 5000 people in Samoa, where obesity rates are among the highest in the world. Ryan Minster at the University of Pittsburgh, Pennsylvania, and his team found that a quarter of Samoans carry this variant, which may have evolved during their history colonising the South Pacific. “They had to endure voyages between islands and subsequently survive on those islands,” says Minster. The CREBRF variant appears to be rare in other populations, but studying how the gene works may help researchers better understand obesity.
Baby earwigs eat faeces in hard times DESPERATE times call for desperate measures. As food shortages hit, young European earwigs resort to eating each other’s excrement in their underground homes, helping to keep hunger and death at bay. When food is plentiful, the earwig offspring, or nymphs, feast on scraps of plant and insect material that their mother brings back from above ground, and on food she regurgitates. But when faced with starvation, the nymphs have to make do with what’s around them. Unlike some other group-living insects, European earwigs don’t clear
their nests of faeces. When food is short, the availability of excrement keeps the nymphs alive for about two more days on average than if there is none present, a team has now found (Behavioral Ecology, doi.org/bmwz). Munching on faeces might also be a way for the young to acquire essential gut microbes, says Maximilian Körner of the Johannes Gutenberg University of Mainz in Germany. The nutritional and microbial gains from faeces may even have kept earwig offspring from straying and given rise to family life in the species, he adds.
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
HIDING scars 800 kilometres wide isn’t as tricky as you might think. If you’re a dwarf planet, all you need is the right kind of mud. The absence of such large impact craters on Ceres, a dwarf planet in the asteroid belt between Mars and Jupiter, has been a puzzle since NASA’s Dawn probe arrived there in March 2015. Ceres has witnessed most of the solar system’s evolution and should be pockmarked with at least 10 giant craters. The latest images from Dawn, still in orbit around Ceres, may just explain why we cannot see them. Simone Marchi and his colleagues at the Southwest Research Institute in Boulder, Colorado, used hi-res images from Dawn to create a model of Ceres’s topography. They found depressions hinting at large craters, all surface traces of which had been wiped out (Nature Communications, DOI: 10.1038/ncomms12257). The team suggests that Ceres’s unusual internal composition and evolution are to blame. Beneath the surface, Ceres could be a slushy cocktail of low-viscosity materials such as ice and clay that form a kind of mud. That would allow the outer layer to shift and relax, potentially smoothing out any large craters. The results confirm that Ceres is a long-term resident of the asteroid belt, says Thomas Davison of Imperial College London.
16 | NewScientist | 30 July 2016
Superatoms joined to make molecules with super properties IT’S Lego for advanced chemists. Superatoms have been linked up to make molecules for the first time. These could be the building blocks for advanced magnetic materials and electronics. Chemists began building superatoms when they found that certain arrangements of atoms can behave like scaled-up versions of an atom of a different element. These superatoms pool their electrons into shells around a central core, and since such shells determine the atom’s chemical properties, the superatom takes
on those characteristics. That lets you get features that wouldn’t appear in nature. Now a team led by Xavier Roy at Columbia University in New York has taken the concept a step further by constructing pairs or trios of superatoms – the simplest possible superatom molecules. The team built the core of the superatoms out of six cobalt and eight selenium atoms, then added arms made from a variety of other atoms. These arms are designed to fit together, mimicking a chemical bond at the super-scale
(Nano Letters, doi.org/bmw5). The materials could have uniquely tunable magnetic properties, Roy says. “We’re aiming to make things where the whole is greater than the sum of the parts,” he says. “We’re interested in new types of magnetic material or conductive material. By controlling the coupling between superatoms, we can tailor that.” The team plans to build large assemblages of superatoms with these tailored properties, which could form the basis for new kinds of electronics and sensors. Joël Meunier
Mud facial worked wonders for Ceres
For new stories every day, visit newscientist.com/news
A gene that piles on the pounds IT COULD be in your DNA. A gene variant that raises the risk of obesity by between 30 and 40 per cent is the strongest genetic predictor of body weight found in humans so far. Having just one copy of this variant of the CREBRF gene is linked to an increase in body mass index of 1.5 points. For an 83-kilogram person who is 1.75 metres tall, this is the equivalent of gaining 4.6 kilograms (Nature Genetics, doi.org/bm2t). The variant was uncovered during a genomic analysis of more than 5000 people in Samoa, where obesity rates are among the highest in the world. Ryan Minster at the University of Pittsburgh, Pennsylvania, and his team found that a quarter of Samoans carry this variant, which may have evolved during their history colonising the South Pacific. “They had to endure voyages between islands and subsequently survive on those islands,” says Minster. The CREBRF variant appears to be rare in other populations, but studying how the gene works may help researchers better understand obesity.
Baby earwigs eat faeces in hard times DESPERATE times call for desperate measures. As food shortages hit, young European earwigs resort to eating each other’s excrement in their underground homes, helping to keep hunger and death at bay. When food is plentiful, the earwig offspring, or nymphs, feast on scraps of plant and insect material that their mother brings back from above ground, and on food she regurgitates. But when faced with starvation, the nymphs have to make do with what’s around them. Unlike some other group-living insects, European earwigs don’t clear
their nests of faeces. When food is short, the availability of excrement keeps the nymphs alive for about two more days on average than if there is none present, a team has now found (Behavioral Ecology, doi.org/bmwz). Munching on faeces might also be a way for the young to acquire essential gut microbes, says Maximilian Körner of the Johannes Gutenberg University of Mainz in Germany. The nutritional and microbial gains from faeces may even have kept earwig offspring from straying and given rise to family life in the species, he adds.