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Freaky spider has a sticky secret
ESA/DLR/FU Berlin (G. Neukum)
in Brief Freaky spider has a sticky secret
Vast glaciers carved out Martian Grand Canyon HUGE glaciers may once have crept through Mars’s version of the Grand Canyon. That’s according to a new analysis of data from NASA’s Mars Reconnaissance Orbiter (MRO) spacecraft, which has spotted telltale signs of minerals left in the glaciers’ wake. Rock formations around Valles Marineris, a system of canyons running more than 4000 kilometres across the Red Planet’s equator, have hinted that it once held glaciers that melted and caused a megaflood. Now Selby Cull at Bryn Mawr College in Pennsylvania and colleagues have found mineralogical evidence that supports the idea.
The team used spectral measurements from MRO to identify a number of minerals in the canyon, including jarosite, which forms in the presence of acid and sulphur. These deposits were spotted halfway up the canyon walls, so can’t have been left by an evaporating pool of water, which is how other jarosite deposits on Mars are thought to have formed. Instead, Cull speculates that heat from the walls could have slightly melted the ice, which in turn reacted with sulphur in the planet’s earlier atmosphere (Geology, doi.org/v48). “The glaciers would have been interacting with the side of the canyons, producing acid melt water,” she says. A similar process has been observed on Earth at the edges of the Svalbard glaciers in Norway.
LSD’s mind-shaping effects revisited COULD taking LSD help people make peace with their neuroses? Psychiatrists in the 1960s certainly thought so. They looked at how LSD influenced people having psychotherapy. The idea was that the drug would mimic the effect of hypnotherapy, making people more suggestible and open to changing their thought patterns. The studies rarely included control groups
so don’t stand up to modern scrutiny. Now a team at Imperial College London are revisiting the idea with more care. Led by David Nutt, the team gave 10 volunteers two shots a week apart, either LSD or a placebo. The subjects acted as their own controls, and didn’t know which dose was which. Two hours after each shot, the volunteers listened to descriptions of scenarios, as
used in hypnotherapy, and were asked to “think along” with each one. They then had to rate the vividness of their mental experiences on a standard scale. The LSD-aided descriptions were 20 per cent more vivid than those associated with the placebo (Psychopharmacology, doi.org/v5j). Treating neuroses requires the therapist to influence the person’s view of themselves, says Nutt. LSD may allow the brain to enter a malleable state for this to happen.
THE harvestman spider – a hunter with a tiny body and very long legs – has a sticky surprise. Once it’s got you, it’ll never let go. In a species called Mitostoma chrysomelas, the second pair of legs are elongated and covered in sticky hairs. Jonas Wolff of the University of Kiel in Germany and colleagues found the hairs carried droplets of a sticky, viscous, yet stretchy liquid. The weird properties of this “viscoelastic” fluid mean that, for a hapless bug called a springtail captured by the harvestman, resistance is futile – the more it struggles, the stronger the glue holds fast (The Journal of Experimental Biology, doi.org/v6p). “It is a non-Newtonian fluid, which means it behaves more like a solid under high stress rates,” says Wolff. The harvestman may have evolved the glue specifically to catch springtails, which use a pre-stressed spring to leap away.
Delicate snowflake best for networks SNOWFLAKE-shaped networks are easiest to fix when disaster strikes. Vital networks like power grids and the internet need to be simple to repair to reduce down time. To determine the best structure for this, Robert Farr of the London Institute for Mathematical Sciences and colleagues simulated a variety of networks. They found the best were made from triangle or square-shaped loops, with one side of each loop missing. The loops link together and then back to a central hub, giving them a branching structure similar to a snowflake. If a link breaks, you just add in the missing side of a loop (Physical Review Letters, doi.org/v5s). The team will now see if the idea could work in real-world networks. 11 October 2014 | NewScientist | 19
in Brief Freaky spider has a sticky secret
Vast glaciers carved out Martian Grand Canyon HUGE glaciers may once have crept through Mars’s version of the Grand Canyon. That’s according to a new analysis of data from NASA’s Mars Reconnaissance Orbiter (MRO) spacecraft, which has spotted telltale signs of minerals left in the glaciers’ wake. Rock formations around Valles Marineris, a system of canyons running more than 4000 kilometres across the Red Planet’s equator, have hinted that it once held glaciers that melted and caused a megaflood. Now Selby Cull at Bryn Mawr College in Pennsylvania and colleagues have found mineralogical evidence that supports the idea.
The team used spectral measurements from MRO to identify a number of minerals in the canyon, including jarosite, which forms in the presence of acid and sulphur. These deposits were spotted halfway up the canyon walls, so can’t have been left by an evaporating pool of water, which is how other jarosite deposits on Mars are thought to have formed. Instead, Cull speculates that heat from the walls could have slightly melted the ice, which in turn reacted with sulphur in the planet’s earlier atmosphere (Geology, doi.org/v48). “The glaciers would have been interacting with the side of the canyons, producing acid melt water,” she says. A similar process has been observed on Earth at the edges of the Svalbard glaciers in Norway.
LSD’s mind-shaping effects revisited COULD taking LSD help people make peace with their neuroses? Psychiatrists in the 1960s certainly thought so. They looked at how LSD influenced people having psychotherapy. The idea was that the drug would mimic the effect of hypnotherapy, making people more suggestible and open to changing their thought patterns. The studies rarely included control groups
so don’t stand up to modern scrutiny. Now a team at Imperial College London are revisiting the idea with more care. Led by David Nutt, the team gave 10 volunteers two shots a week apart, either LSD or a placebo. The subjects acted as their own controls, and didn’t know which dose was which. Two hours after each shot, the volunteers listened to descriptions of scenarios, as
used in hypnotherapy, and were asked to “think along” with each one. They then had to rate the vividness of their mental experiences on a standard scale. The LSD-aided descriptions were 20 per cent more vivid than those associated with the placebo (Psychopharmacology, doi.org/v5j). Treating neuroses requires the therapist to influence the person’s view of themselves, says Nutt. LSD may allow the brain to enter a malleable state for this to happen.
THE harvestman spider – a hunter with a tiny body and very long legs – has a sticky surprise. Once it’s got you, it’ll never let go. In a species called Mitostoma chrysomelas, the second pair of legs are elongated and covered in sticky hairs. Jonas Wolff of the University of Kiel in Germany and colleagues found the hairs carried droplets of a sticky, viscous, yet stretchy liquid. The weird properties of this “viscoelastic” fluid mean that, for a hapless bug called a springtail captured by the harvestman, resistance is futile – the more it struggles, the stronger the glue holds fast (The Journal of Experimental Biology, doi.org/v6p). “It is a non-Newtonian fluid, which means it behaves more like a solid under high stress rates,” says Wolff. The harvestman may have evolved the glue specifically to catch springtails, which use a pre-stressed spring to leap away.
Delicate snowflake best for networks SNOWFLAKE-shaped networks are easiest to fix when disaster strikes. Vital networks like power grids and the internet need to be simple to repair to reduce down time. To determine the best structure for this, Robert Farr of the London Institute for Mathematical Sciences and colleagues simulated a variety of networks. They found the best were made from triangle or square-shaped loops, with one side of each loop missing. The loops link together and then back to a central hub, giving them a branching structure similar to a snowflake. If a link breaks, you just add in the missing side of a loop (Physical Review Letters, doi.org/v5s). The team will now see if the idea could work in real-world networks. 11 October 2014 | NewScientist | 19