Paralyzed woman controls robotic arm, sips coffee

A tetraplegia controls a robotic arm, allowing herself to have a drink.

braingate2.org

Performing even a simple movement is a rather complicated process. First, the brain has to signal its intent to perform an action, which then gets translated into the specific motions that are required to achieve that intention. Those motions require a series of muscle contractions; the signals for these need to be sent out of the brain, through the spinal cord, and to the appropriate destination.

For most people who suffer from paralysis, it's really these later steps that are affected—most of the setup can still go on in the brain, but damage keeps the signals from making their way to the muscles. If there were a way to eavesdrop on the brain, it might be possible to identify an individual's intent and translate that into some form of useful action.

This may sound like science fiction, but significant progress has been made in the area. As far back as 2006, researchers were already reporting that electrodes placed in a person's motor cortex would allow them to manipulate an on-screen object in a three-dimensional environment. More recently, monkeys with a similar implant were hooked up to a robotic arm, which they learned to use to perform some simple tasks.

Sheets of Virus Generate Electricity when Squished

Pressing a virus-filled device can generate power. (The gloves protect the virus, which only infects bacteria, from us.)

lbl.gov

Squishing a stack of virus sheets generates enough electricity to power a small liquid crystal display. With increased power output, these virus films might one day use the beating of your heart to power a pacemaker, the researchers behind them say.

Piezoelectric materials build up charge when pushed or squeezed. These materials may be familiar to you: they generate the spark in a gas lighter, and motors powered by such materials vibrate some cell phones. Piezoelectric materials made of metals or polymers require large inputs of energy to build up a charge. Bone, DNA, and protein fibers are weakly piezoelectric, but it’s hard to efficiently organize these materials on a large scale to yield electricity.

To handle this organizational issue, Seung-Wuk Lee, of the University of California in Berkeley and the Lawrence Berkeley National Laboratory, and his colleagues looked for a biomaterial that had intrinsic order and was easy to make. They settled on the M13 bacteriophage, a rod-shaped virus that only infects bacteria. One bacterium can produce one million copies of the virus within four hours, so starting material isn't a problem. And the virus neatly arranges itself in stacked rows when spread on a surface.

Spring flowers blooming earlier than experiments predict

Scott Johnson

The mild winter and early spring in the US this year led to some incredible sights: magnolia trees near me blooming in March (a full month ahead of 2011), migratory birds returning much earlier than usual, and sun-starved Midwesterners breaking out t-shirts and shorts in February. This strange weather illustrated, to an extreme, one of the most obvious effects of climate change: as temperatures warm, spring breaks through earlier, and these annual spectacles shift along with it.

In order to understand how ecosystems will respond to a warming climate, it’s critical to understand the interplay between the timing of these events. To do this, researchers look at the way plants (and animals) have responded to the warming we’ve experienced so far, but they also rely on warming experiments that manipulate temperatures in the field. A new study in Nature reviews the existing evidence and finds a problematic discrepancy—the responses we're seeing in the real world are much greater than the warming experiments would predict.

Those warming experiments typically involve placing transparent walls around individual plants in the field to create a slight greenhouse (the glass kind) effect without enclosing the plant completely. Ideally, this effectively increases the temperature of the air around the plant without altering any other factors, like sunlight or moisture. The neighboring plants that lack cozy walls of their own act as a control group for comparison.

Spring flowers blooming earlier than experiments predict

Scott Johnson

The making of modern humans

SUNY Orange

What is it exactly that makes modern humans modern? We are subject to jet lag? We can walk and text at the same time (some of us, kind of?) Our minds and bodies bear the brunt of all the junk we’ve been spewing into the earth’s air, water, and soil since the Industrial Revolution?

Chris Stringer, a research leader in human origins at the Natural History Museum London, recently wrote a Comment in Nature speculating on what the precise features might be that define us as modern. Recent DNA evidence has shown that after modern humans left Africa around 60,000 years ago, they interbred with different groups of archaic humans—Neanderthals and Denisovans. As a result, different populations walking around today have varying amounts of this archaic DNA in their genomes.

Stringer is aware that this information could lead to the very dangerous assertion that all humans are modern, but some are more modern than others. So he writes, “All living humans are members of the extant species H. sapiens and, by definition, all must equally be modern humans.”

The making of modern humans

SUNY Orange

Belching dinosaurs may have helped keep their world a hot one

The world inhabited by dinosaurs was typically a hot one, with high levels of greenhouse gasses, lots of water vapor, and no permanent ice sheets. And, according to a new estimate published in the journal Current Biology, the dinosaurs themselves may have contributed to their hothouse conditions.

(Note to the editors of Current BIology: I'm not sure that the Jurassic really qualifies as "current.")

A team of British researchers has put together various estimates of the features of the Jurassic's large herbivores, such as population density, typical body mass, and so on. Combined with an estimate of how much methane is emitted by a typical herbivore, these numbers suggest that the dinosaurs were pouring out enough methane to help the greenhouse effect keep the Earth nice and toasty.

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Belching dinosaurs may have helped keep their world warm

pitt.edu

(Note to the editors of Current BIology: I'm not sure that the Jurassic really qualifies as "current.")

Research finally published showing how bird flu virus can spread among mammals

For years, public health officials have been watching the H5N1 bird flu virus warily. When it hops from birds to people, it has a disturbing tendency to kill them. So far, however, it has been unable to spread from person to person, which has kept the world safe from a lethal pandemic. That posed a rather significant question: could the bird flu ever evolve the ability to spread among mammals, and if it did, would it remain lethal?

Two teams of researchers, one in the US and the other in the Netherlands, set out to answer that question by selecting for a virus that could spread among ferrets, an animal commonly used for flu research. But the publications describing their work have been held up, as the US National Science Advisory Board for Biosecurity debated whether the possibility of weaponizing the virus posed too large a risk. Now, finally, after months of debate, the first of the papers will appear in Nature. It provides a partial answer to the big question—it should be possible for the virus to spread among mammals—but doesn't address whether this would pose a threat.

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Bird flu paper published despite worries of weaponization

Artist rendering of a chicken/ferret hybrid, not at all how scientists actually did the research.

Photo illustration by Aurich Lawson

The rough outline of the results has been known for months, as the researchers presented them at meetings and submitted them to Science and Nature. The NSABB got involved, and asked the journals to hold off on publishing. After a series of debates both public and private, the papers were given the go-ahead (although not everyone involved in that decision agrees).