- Email: [email protected]
Programmable pop-up materials
Baertels/plainpicture
in Brief Artificial fibre as tough as spider silk
Drat! Where’s the nectar? I was sure it was this flower EVER remembered something that turned out to be false? Bumblebees may be prone to similar lapses. Although bees have good memories, they have a lot to recall, including the colours and locations of flowers. “Bees make more mistakes when they juggle multiple memories than if they just focus on one flower type,” says Lars Chittka of Queen Mary University of London. Chittka and his colleague Kathryn Hunt investigated whether bees make false memories, as humans often do. This happens when an individual remembers something they haven’t actually experienced – a problem for
witnesses in trials and for students, who may misremember what they were taught. The researchers trained bees using artificial flowers that were either yellow or had a black-and-white ringed pattern. The flowers offered a nectar-like reward, but at different times. When tested within minutes of their training, bees usually visited a flower of the type that had most recently rewarded them. But as time wore on, some bees started opting for a completely new type of flower – one with yellow and white rings. The bees seemed to have become confused, merging their memories to create a false one (Current Biology, doi.org/2gp). ”There might be items in a bumblebee’s memory library that they have never actually encountered in real life,” says Chittka.
Treating inherited disease in the womb BABIES with a genetic disease may face a lifetime of treatment. But what if the baby’s immune system could be primed for treatment before they were born? Our immune systems are usually good at destroying foreign material in our bodies. But this doesn’t apply in the womb: a study in the 1950s showed that mice undergoing skin grafts from donor mice were more likely to
accept it if they had been exposed to the donor cells as fetuses. Sébastien Lacroix-Desmazes at INSERM in Paris and his colleagues wondered if this could help treat inherited diseases, such as haemophilia. This is caused by the lack of a clotting protein and can be treated with protein injections. But in some cases, the protein is rejected by the immune system. To see if fetal priming
could help, the team gave clotting protein to pregnant mice bred to lack it. Other similar pregnant mice received no treatment. Once the pups were born, all were treated with protein therapy. The mice primed in the womb were much more tolerant of the protein – their immune systems produced 80 per cent less antibody against it than the unprimed mice (Science Translational Medicine, doi.org/2c5).
SPIDER silk is stronger than steel and tougher than Kevlar, but efforts to spin our own have so far failed to match the real thing. Now a German research group has equalled its toughness. Previous attempts to mimic spider silk have focused on two molecules that provide its material properties. But Thomas Scheibel at the University of Bayreuth in Germany and his colleagues realised that this neglected two smaller molecules that help align the strands. His team spliced spider genes into E. coli, which enabled the bacteria to produce all four molecules in a bath of alcohol and water. The team then used a method called wet spinning to draw out the fibres, creating the artificial silk (Advanced Materials, doi.org/f253cq). The material is not as strong as real silk, but is more elastic, so it can absorb as much energy as the real thing.
Programmable pop-up materials NORMALLY you can rely on solid objects to hold their shape. But now there’s a way to make flat surfaces pop into complex 3D shapes when heated – which could find uses from medicine to flight. Taylor Ware at the WrightPatterson Air Force Base in Ohio and team created a film of elastic polymers that contains a crystal lattice. Shining polarised laser light on the film changes the way the lattice is aligned, and can be used to draw a pattern. Because the crystal’s thermal properties aren’t the same in all directions, heating the film to 175 °C makes some parts of the pattern expand and others contract. The preplanned 3D shape formed can be 100 times as tall as the film is thick (Science, doi.org/2gz). 7 March 2015 | NewScientist | 17
in Brief Artificial fibre as tough as spider silk
Drat! Where’s the nectar? I was sure it was this flower EVER remembered something that turned out to be false? Bumblebees may be prone to similar lapses. Although bees have good memories, they have a lot to recall, including the colours and locations of flowers. “Bees make more mistakes when they juggle multiple memories than if they just focus on one flower type,” says Lars Chittka of Queen Mary University of London. Chittka and his colleague Kathryn Hunt investigated whether bees make false memories, as humans often do. This happens when an individual remembers something they haven’t actually experienced – a problem for
witnesses in trials and for students, who may misremember what they were taught. The researchers trained bees using artificial flowers that were either yellow or had a black-and-white ringed pattern. The flowers offered a nectar-like reward, but at different times. When tested within minutes of their training, bees usually visited a flower of the type that had most recently rewarded them. But as time wore on, some bees started opting for a completely new type of flower – one with yellow and white rings. The bees seemed to have become confused, merging their memories to create a false one (Current Biology, doi.org/2gp). ”There might be items in a bumblebee’s memory library that they have never actually encountered in real life,” says Chittka.
Treating inherited disease in the womb BABIES with a genetic disease may face a lifetime of treatment. But what if the baby’s immune system could be primed for treatment before they were born? Our immune systems are usually good at destroying foreign material in our bodies. But this doesn’t apply in the womb: a study in the 1950s showed that mice undergoing skin grafts from donor mice were more likely to
accept it if they had been exposed to the donor cells as fetuses. Sébastien Lacroix-Desmazes at INSERM in Paris and his colleagues wondered if this could help treat inherited diseases, such as haemophilia. This is caused by the lack of a clotting protein and can be treated with protein injections. But in some cases, the protein is rejected by the immune system. To see if fetal priming
could help, the team gave clotting protein to pregnant mice bred to lack it. Other similar pregnant mice received no treatment. Once the pups were born, all were treated with protein therapy. The mice primed in the womb were much more tolerant of the protein – their immune systems produced 80 per cent less antibody against it than the unprimed mice (Science Translational Medicine, doi.org/2c5).
SPIDER silk is stronger than steel and tougher than Kevlar, but efforts to spin our own have so far failed to match the real thing. Now a German research group has equalled its toughness. Previous attempts to mimic spider silk have focused on two molecules that provide its material properties. But Thomas Scheibel at the University of Bayreuth in Germany and his colleagues realised that this neglected two smaller molecules that help align the strands. His team spliced spider genes into E. coli, which enabled the bacteria to produce all four molecules in a bath of alcohol and water. The team then used a method called wet spinning to draw out the fibres, creating the artificial silk (Advanced Materials, doi.org/f253cq). The material is not as strong as real silk, but is more elastic, so it can absorb as much energy as the real thing.
Programmable pop-up materials NORMALLY you can rely on solid objects to hold their shape. But now there’s a way to make flat surfaces pop into complex 3D shapes when heated – which could find uses from medicine to flight. Taylor Ware at the WrightPatterson Air Force Base in Ohio and team created a film of elastic polymers that contains a crystal lattice. Shining polarised laser light on the film changes the way the lattice is aligned, and can be used to draw a pattern. Because the crystal’s thermal properties aren’t the same in all directions, heating the film to 175 °C makes some parts of the pattern expand and others contract. The preplanned 3D shape formed can be 100 times as tall as the film is thick (Science, doi.org/2gz). 7 March 2015 | NewScientist | 17