Innovation and Technology Weekly – No. 29, 2014

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Issue 29, 2014

This week's headlines:

'Bio-spleen' uses magnets to clean bad blood
September 15, 2014

A device that uses magnets to extract bacteria, fungi and toxins from blood could one day throw a lifeline to patients with sepsis and other infections, researchers say. They say the external gadget - tested so far in rats but not yet humans - might also eventually be modified to strip Ebola and other viruses from blood.

The device was inspired by the spleen, which can continuously remove pathogens and toxins from blood without first identifying the infectious agent. Dubbed a 'bio-spleen', the invention uses magnetic nanobeads coated with a genetically-engineered human blood protein called mannose-binding lectin (MBL). The MBL binds to pathogens and toxins, which can then be 'pulled out' with a magnet.

In live rats infected with the notorious bugs Staphylococcus aureus or Escherichia coli, the device removed 90 per cent of bacteria from the blood, the researchers report. Tests with human blood in the lab also showed the bio-spleen cleaned out multiple species of bacteria, fungi and toxins.

Full story: ABC News / AFP / Nature Medicine Back to top

Hacked photosynthesis could boost crop yields
September 17, 2014

It is difficult to find fault with a process that can create food from sunlight, water and air, but for many plants, there is room for improvement. Researchers have taken an important step towards enhancing photosynthesis by engineering plants with enzymes from blue-green algae that speed up the process of converting carbon dioxide into sugars.

Researchers have long wanted to increase yields by targeting Rubisco, the enzyme responsible for converting carbon dioxide into sugar. Rubisco is possibly the most abundant protein on Earth, and can account for up to half of all the soluble protein found in a leaf.

But one reason for its abundance is its inefficiency: plants produce so much Rubisco in part to compensate for its slow catalysis. Some have estimated that tinkering with Rubisco and ways to boost the concentration of carbon dioxide around it could generate up to a 60% increase in the yields of crops such as rice and wheat.

Researchers from Cornell University in Ithaca, New York, decided to borrow a faster Rubisco from the cyanobacterium Synechococcus elongatus. They shuttled bacterial Rubisco genes into the genome of the chloroplast in the tobacco plant. In some of the plants the researchers also added a bacterial protein that is thought to help Rubisco to fold properly. In others, they added a bacterial protein that structurally supports Rubisco. Both lines of tobacco were able to use the bacterial Rubisco for photosynthesis, and both converted CO2 to sugar faster than normal tobacco.

Full story: Nature Back to top

Sugar substitutes linked to obesity
September 17, 2014

The artificial sweeteners that are widely seen as a way to combat obesity and diabetes could, in part, be contributing to the global epidemic of these conditions.

Sugar substitutes such as saccharin might aggravate these metabolic disorders by acting on bacteria in the human gut, according to a new study. Smaller studies have previously purported to show an association between the use of artificial sweeteners and the occurrence of metabolic disorders. This is the first work to suggest that sweeteners might be exacerbating metabolic disease, and that this might happen through the gut microbiome, the diverse community of bacteria in the intestines.

A team at the Weizmann Institute of Science in Israel fed mice various sweeteners - saccharin, sucralose and aspartame - and found that after 11 weeks, the animals displayed glucose intolerance, a marker of propensity for metabolic disorders.

To simulate the real-world situation of people with varying risks of these diseases, the team fed some mice a normal diet, and some a high-fat diet, and spiked their water either with glucose alone, or with glucose and one of the sweeteners, saccharin. The mice fed saccharin developed a marked glucose intolerance compared to those fed only glucose. But when the animals were given antibiotics to kill their gut bacteria, glucose intolerance was prevented. When the team transplanted faeces from the glucose-intolerant saccharin-fed mice into the guts of mice bred to have sterile intestines, those mice also became glucose intolerant, indicating that saccharin was causing the microbiome to become unhealthy.

Full story: Nature Back to top

'Artificial retina' could detect sub-atomic particles
September 19, 2014

The human eye has inspired physicists to create a processor that can analyse sub-atomic particle collisions 400 times faster than currently possible. In these collisions, protons - ordinary matter - are smashed together at close to light speeds.

These powerful smash-ups could yield new particles and help scientists understand matter's mirror, antimatter. The experimental processor could speed up the analysis of data from the collisions. The algorithm has been proposed for possible use in Large Hadron Collider (LHC) experiments at CERN in 2020. It could also be useful in any field where fast, efficient pattern recognition capabilities are needed.

The processor works in a similar way to the retina's incredible ability to recognise patterns extremely quickly. That is, individual neurons in our retinas are specialised to respond to particular shapes or orientations, which they do automatically before our brain is even consciously aware of what we are processing.

The 'artificial retina' detects a snapshot of the trajectory of each collision which is then immediately analysed. These snapshots are then mapped into an algorithm that can run on a computer, automatically scanning and analysing the charged particle trajectories, or tracks. Exposing the detector to future collisions will then allow teams sift out the interesting events.

Speed is of the essence here. There are roughly 40 million collisions per second and each can result in hundreds of charged particles. An algorithm like this could therefore provide a useful way of crunching through this vast amount of data, in real time.

Full story: BBC News / arXiv Back to top

Temperature-driven clock sparks new kind of generator
September 18, 2014

A device that harvests electricity from tiny changes in air temperature could power the sensors of the future.

Researchers from the University of Washington in Seattle filled a small bellows with chloroethane gas, which expands and contracts a great deal for small temperature fluctuations. The resulting movement of the bellows in turn moves a magnet inside a coil, producing a current. The team found that for just a 0.25 °C change in temperature they were able to generate enough juice to wirelessly update an ebook page from 5 metres away.

The team were inspired to develop their harvester after reading about the Atmos clock developed by Swiss inventor Jean-Léon Reutter in 1928. The clock had bellows filled with chloroethane, and an attached mechanism that wound the clock's mainspring. Changes in ambient temperature of just 1 °C were enough to keep the clock going for two days.

The team is now attempting to improve the power output and shrink the device to the size of a D-cell battery. The researchers say the device could work continuously for decades without maintenance, making it ideal for powering hard-to-reach sensors, such as those monitoring pipes for leaks, or for indoor positioning beacons.

Full story: New Scientist Back to top

Lasers slim down on stopped-light diet
September 17, 2014

A new kind of laser that powers up by freezing light in its tracks could lead to computers that run on photons instead of electrons.

Researchers already have ways to slow light down and even stop it completely for as long as a minute. Now researchers at Imperial College London say that this principle could be used to shrink lasers. Ordinary lasers work by bouncing light between two mirrors, so photons of a certain wavelength accumulate. But these devices can't be made very small. A stopped-light laser would be different.

The laser consists of an electrically insulating material sandwiched between two metals. Pulses of light travelling in one direction through the insulator reverse direction as they enter the metal, trapping the light in a vortex.

Simulations show that energy builds up in the vortex for around 10 trillionths of a second before it breaks free in a coherent beam of light, just like a laser. What's more, it could potentially release a range of frequencies at once, more like a light bulb than a traditional laser with a characteristic colour.

The team is now working to build the laser. If they succeed, it could find a use in optical computing, where information is transported by photons rather than electrons. Other lasers are too bulky for nanoscale circuits, but a stopped-light laser would be small enough, enabling faster data transmission within a chip.

Full story: New Scientist / Nature Communications Back to top

Chin strap makes electricity from chewing
September 17, 2014

Engineers from the Ecole de Technologie Supérieure in Montreal, Canada, have built a chin strap that harnesses energy from chewing and turns it into electricity. They say the device could one day take the place of batteries in hearing aids, earpieces and other small gadgets.

Made from a 'smart' piezoelectric material that becomes electrically charged when stretched, the prototype needs to be made 20 times more efficient in order to generate useful amounts of power. The researchers say they can achieve this by adding layers of the material.

The team is also investigating other, more efficient starting materials. The researchers think the idea could be useful mostly for situations where people are already wearing a strap, and could plug in a small but essential gadget. People who work with heavy machinery for example or soldiers wearing head protection and communicating using earpieces.

Full story: BBC News / Smart Materials and Structures Back to top