Innovation and Technology Weekly – No. 26, 2013

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Issue 26, 2013

This week's headlines:

Microbial duo boost biofuel production
August 20, 2013

Researchers from the University of Michigan have paired up a fungus and a bacteria to produce high-quality biofuel from agricultural waste materials such as corn stalks and leaves. Using the fungus Trichoderma reesei and the common bacteria Escherichia coli, the researchers were able to produce 1.88 grams of the biofuel isobutanol, per litre of fluid, which represents the highest concentration yet achieved in the conversion of plant material into biofuel.

The researchers chose isobutanol as their desired biofuel, rather than the more common ethanol, because isobutanol gives off 82% of the heat energy petrol provides when burned, compared to ethanol's 67%. Unlike ethanol, isobutanol doesn't easily absorb water, which can corrode pipelines and damage engines. They also took the relatively new approach of using two types of microbes rather than one.

The fungus T. reesei breaks down the tough feedstock into sugars, and the E. coli then converts those into the desired fuel. However coaxing the two microbes to cooperate is no easy task as co-cultures are notoriously fragile and unstable.

The key to this success was finding microbes that in some way depended on each other - or in this case, one microbe acts as the co-operator while the other is more of a 'cheater'. However the co-operator - the fungus - still gets something out of the process because as part of converting the cellulose to sugars, it concentrates the food around itself. The researchers are now focused on improving the efficiency of the process.

Full story: ABC Net / PNAS Back to top

Anti-mosquito 'invisibility' patch set for Uganda trial
August 22, 2013

A patch designed to make people 'invisible' to disease-transmitting mosquitoes may soon undergo field trials in Uganda.

The Kite Patch, developed by researchers from Olfactor Laboratories, United States, is a small sticker for clothes that works by disrupting mosquitoes' ability to sense exhaled CO2 and human odour - the key known ways by which the insect finds people to bite.

A single patch is designed to provide protection for two days and to be effective against all mosquito species. As the CO2-sensing mechanism is common to all species of mosquitoes, the patch should be effective against all, according to the researchers.

After undergoing preliminary laboratory tests, the patch is now ready for large-scale production and field-testing, and the company is crowdsourcing funds to assess the patch in Uganda. Olfactor Laboratories has filed for a patent on the patch and is collaborating with NGOs to make it available worldwide. The patch contains non-toxic compounds that are approved by the US Food and Drug Administration.

The Kite Patch research team is also looking at how mosquitoes are affected by re-exposure to the chemicals in the patches and whether they might become resistant to them.

Full story: SciDev Back to top

New flow battery could enable cheaper, more efficient energy storage
August 16, 2013

MIT researchers have engineered a new rechargeable flow battery that doesn't rely on expensive membranes to generate and store electricity. The device may one day enable cheaper, large-scale energy storage.

The palm-sized prototype generates three times as much power per square centimetre as other membraneless systems - a power density that is an order of magnitude higher than that of many lithium-ion batteries and other commercial and experimental energy-storage systems.

The device stores and releases energy in a device that relies on a phenomenon called laminar flow: Two liquids are pumped through a channel, undergoing electrochemical reactions between two electrodes to store or release energy. Under the right conditions, the solutions stream through in parallel, with very little mixing. The flow naturally separates the liquids, without requiring a costly membrane.

The reactants in the battery consist of a liquid bromine solution and hydrogen fuel. The group chose to work with bromine because the chemical is relatively inexpensive and available in large quantities, with more than 243,000 tons produced each year in the United States.

In addition to bromine's low cost and abundance, the chemical reaction between hydrogen and bromine holds great potential for energy storage. But fuel-cell designs based on hydrogen and bromine have largely had mixed results: Hydrobromic acid tends to eat away at a battery's membrane, effectively slowing the energy-storing reaction and reducing the battery's lifetime. To circumvent these issues, the team landed on a simple solution: Take out the membrane.

Full story: TG Daily Back to top

Atomic clocks set new world precision record
August 23, 2013

US scientists from the National Institute of Standards and Technology say they have built the world's most precise atomic clocks. The two clocks, made from the element ytterbium, could be used for technological advancements beyond timekeeping, such as navigation systems, magnetic fields and temperature.

The clocks' ticking rate varies less than two parts in one quintillion, or 10 times better than any other atomic clock, the scientists report.

While mechanical clocks use the movement of a pendulum to keep time, atomic clocks use an electromagnetic signal of light emitted at an exact frequency to move electrons in caesium atoms.

The physicists built their ytterbium clocks using about 10,000 rare-earth atoms cooled to 10 microkelvin and trapped in an optical lattice made of laser light. Another laser that 'ticks' 518 trillion times per second triggers a transition between two energy levels in the atoms. The clock's high stability is owed to the large number of atoms.

The new clocks can achieve precise results very quickly. Technicians must average the current US civilian time standard, the NIST-F1 caesium fountain clock, for about 400,000 seconds (about five days) to obtain its best performance. But the new ytterbium clocks can achieve that same result in about one second of averaging time.

Full story: ABC Net / Science Back to top

Computer can read letters directly from the brain
August 19, 2013

Functional MRI scanners have been used in cognition research primarily to determine which brain areas are active while test subjects perform a specific task. The question is simple: is a particular brain region on or off? The Radboud University team has gone a step further and used data from the scanner to determine what a test subject is looking at.

The researchers 'taught' a model how small volumes of 2x2x2 mm from the brain scans - known as voxels - respond to individual pixels. By combining all the information about the pixels from the voxels, it became possible to reconstruct the image viewed by the subject. The result was not a clear image, but a somewhat fuzzy speckle pattern. In this study, the researchers used hand-written letters.

After this the researchers gave the model prior knowledge by teaching it what letters look like, which improved the recognition of the letters enormously. The model compares the letters to determine which one corresponds most exactly with the speckle image, and then pushes the results of the image towards that letter. The result is a true reconstruction.

Full story: Science Daily / Neuroimage Back to top

A blood test for suicide?
August 20, 2013

A substance that has been found at elevated levels in the blood of people likely to kill themselves could lead to a simple diagnostic test for suicide risk, researchers from the Indiana University School of Medicine report.

Clinicians rely on people's self-reported symptoms and feelings to decide who is in need of immediate help, but a person intent on suicide isn't always forthcoming. An unambiguous blood test would show clinicians who is in immediate danger.

The results came out of a larger study on men with bipolar disorder. As part of that research, subjects would visit a clinic every three to six months, where they would undergo psychological testing and give a blood sample. Over the course of the study, nine men showed a dramatic change between visits, first exhibiting no signs of suicidal tendencies and later exhibiting many.

Several biological molecules in the blood of these people changed along with this suicidal shift. Most notable was a molecule made by the gene SAT1, which is involved in cell death. For these nine men, high SAT1 activity tracked with more suicidal thoughts and feelings. To see if SAT1 might track with suicide more generally, the team obtained blood samples from a coroner's office. SAT1 activity was found to be high in the blood of nine different men who had killed themselves.

Full story: Science News / Molecular Psychiatry Back to top

Listen to the music of the drones to forecast weather
August 22, 2013

There's a buzz in the air. A system that listens to the sound of a drone's propellers and deduces atmospheric conditions could one day be used for measuring air pollution, and even providing weather updates.

Developed by researchers from the University of South Australia in Adelaide, the system uses an array of ground-based microphones to listen for the distinctive sound created by the propellers of a small uncrewed aircraft. Columns of air between the drone and the microphones distort the sound depending on the air temperature and how fast the air is moving. If the system knows the sound made at the source, it can analyse the distortions to work out the properties of the air.

A test in St Leonards, Victoria, used five microphones and one drone to measure air temperature and wind speed up to 500 metres above ground, finding a temperature gradient that went from 21 °C at ground level to 18 °C at 500 metres. The researchers say the approach could lead to mobile weather stations that can monitor large volumes of atmosphere and can move to follow weather patterns.

Full story: New Scientist Back to top