Wearable tech gets sweaty

It's the wearable tech that measures your sweat - and it could tell you more about your body than you think. A team from the University of California has revealed in the journal Nature a new, wearable sensor that measures molecules in sweat to obtain real-time information on an individual's physiology and health. The sensor analyses the sweat of humans engaged in prolonged outdoor and indoor physical activities. As human sweat contains physiologically and metabolically rich information, the sensors could prove useful in disease diagnosis, drug abuse detection and athletic performance optimisation, among other applications. While there are already sensors available that can track individuals' physical activities and vital signs, such as heart rate, these are unable to provide information on the users' health at molecular levels.

Zebra's stripes discourage tiny predators

How did the zebra get its stripes?

Researchers have just concluded that it certainly wasn't to help the charismatic animals blend in to the background and protect them from predators. "The most longstanding hypothesis for zebra striping is crypsis, or camouflaging, but until now the question has always been framed through human eyes," said Dr Amanda Melin of the University of Calgary, who led a new study published in PLOS ONE. "We, instead, carried out a series of calculations through which we were able to estimate the distances at which lions and spotted hyenas, as well as zebras, can see zebra stripes under daylight, twilight, or during a moonless night." They found stripes played no part in camouflage as predators could see them - and probably smell and hear the animals anyway. The findings point to a perhaps more likely explanation that the stripes provide an evolutionary advantage by discouraging biting flies, which are natural pests of zebras.

Tiny conical etchings in a window have a self-cleaning effect. Photo / Engineering and Physical Sciences Research Council
Tiny conical etchings in a window have a self-cleaning effect. Photo / Engineering and Physical Sciences Research Council
These super-windows clean themselves

Washing windows could become a thing of the past. A research team from University College London have turned to nanotechnology to develop "smart windows" that can clean themselves, save energy and block glare.

Because the prototype window is ultra-resistant to water, rain hitting the outside forms spherical droplets that roll easily over the surface, picking up dirt, dust and other contaminants and carrying them away.

This was due to the conical design of nanostructures engraved on the glass, trapping air and ensuring only a tiny amount of water touched the surface. A very thin vanadium dioxide film trapped thermal radiation during cold periods, providing heat, while the nanostructures also gave the windows the same anti-reflective properties found in the eyes of moths. "The bio-inspired nanostructure amplifies the thermochromics properties of the coating and the net result is a self-cleaning, highly performing smart window," said research team leader Dr Ioannis Papakonstantinou.

It's life, Jim, but we never knew it

Scientists have put forward a glum theory as to why the search for life on other planets is a tough one: the aliens have already died. While the universe is probably filled with habitable planets, life upon them would likely become extinct very quickly, astrobiologists from the Australian National University have explained. In studies aiming to understand how life might develop, the scientists realised new life would commonly die out because of runaway heating or cooling on their fledgling planets. "Early life is fragile, so we believe it rarely evolves quickly enough to survive," said lead author Dr Aditya Chopra. Most early planetary environments are also unstable, he added. Earth, Venus and Mars may have all been habitable four billion years ago, but a billion years or so after formation, Venus turned into a hothouse and Mars froze.

Ovulation radars

Swiss researchers have just provided one of the year's strangest findings so far: women with higher levels of oestrogen can spot when another woman is ovulating.

Following on from research that found men were more attracted to a woman when she was ovulating - as they were the more likely to conceive - the researchers set out to find if the same was true in women. The study found women didn't label a woman as more attractive at different stages of the menstrual cycle but those with higher levels of oestrogen did label ovulating women as more threatening - suggesting an evolutionary trait, as they would be deemed to pose a reproductive threat.