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Scientists Flip Switch on Genes With a Magnet

Matching the brain’s machinery to behaviors and emotions was risky business throughout much of medical history. It was achievable, more or less, only through clumsy techniques such as lobotomies. Examiners who removed chunks of the brain could observe the surgery’s effects, but patients had to live with the results.

The rise of optogenetics, in which light in the form of lasers is used to manipulate individual neurons, has improved the situation slightly. But this technique still works only in regions of the brain where it’s easy to shine light. Neuroscientists must physically insert a fiber optic cable to study anything that isn’t easily accessible.

Now a team from the University of Virginia has shown that it’s possible to use a magnet to control neurons embedded deep in the brains of mice. This technique could offer a non-invasive alternative to optogenetics and aid researchers eager to understand the underpinnings of emotions or more clearly identify the origins of cognitive disorders.

By using this technique to flip genes on and off, researchers could trace neural circuits and determine which behaviors or feelings are affiliated with specific pathways in the brain. Ali Guler, a biochemist, led the group that published the results of this proof-of-concept research in the 7 March edition of Nature Neuroscience.

Guler, aware of the limits of other examination methods, wanted to find a way to remotely control neurons. His idea was to create a genetic analog to techniques used to alter cellular functions. If simple adjustments to calcium ion channels can change important processes such as muscle contraction and hormone secretion, he reasoned, why can’t we manipulate hard-to-reach areas of the brain, but with genetic switching as the trigger?

With this strategy in mind, he created a tool that linked the gene for a protein called TRPV4 (which serves as a gatekeeper for ion channels) with a gene for an iron-fixing protein called ferritin. Connecting the two genes in this way enabled his team to tug the ion channels open or push them closed simply by moving the nearby iron with a magnet.

"It's essentially a biological nanomagnet,” Guler says. He dubbed the creation “Magneto” for the Marvel comic book character capable of generating magnetic fields at will.

In one experiment, the Virginia researchers inserted the specially-designed Magneto genes in a virus, which acted as the transport medium to ferry the magnetic field–susceptible gene product to the striata of six mice. The aim: to see if they could switch ion channels open and closed in a way that might mimic the pleasurable effects of dopamine. The striatum, which processes rewards, is buried beneath the wrinkly bulk of the forebrain and has proven difficult to reach by other methods. If the technique worked, they figured, they could use Magneto in other parts of the brain to mimic different hormones and neurotransmitters. Six other mice formed the control group.

The researchers put all 12 mice into a chamber that was magnetized at one end. Their hypothesis: that the Magneto-carrying mice would scramble for the magnetized side because the open ion channels in their striata would give them a dopamine-like rush of pleasure. Indeed, they found that all six of the Magneto mice preferred to spend their time on the magnetized side of the chamber while all but one of the control mice kept to the non-magnetized end.

When Guler measured the rate at which the mice’s neurons fired, he found that the neurons in Magneto mice at the magnetized end fired more frequently than those in the untreated mice—an effect he would expect to see with true dopamine.

In the future, Guler says, this technique could be used to map neural pathways, tinker with behaviors, and compare neurons in different parts of the brain. “Similar to the optogenetic strategies, you can manipulate any group of neurons that you would like to control,” he says.

If that sounds eerie, rest assured that this power will stay confined to the lab for the time being. The synthetic genes that responded to Guler’s magnet were specially designed and built for this purpose. Magnets would not have the same effect on normal neurons in mice or people.


Biodegradable Power Generators Could Power Medical Implants

Biodegradable devices that generate energy from the same effect behind most static electricity could help power transient electronic implants that dissolve in the body, researchers say.

Implantable electronic devices now help treat everything from damaged hearts to traumatic brain injuries. For example, pacemakers can help keep hearts beating properly, while brain sensors can monitor patients for potentially dangerous swelling in the brain.

However, when standard electronic implants run out of power, they need to be removed lest they eventually become sites of infection. But their surgical removal can result in potentially dangerous complications. Scientists are developing transient implantable electronics that dissolve once they are no longer needed, but these mostly rely on external sources of power, limiting their applications.

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Forty Years Later, Turing Prize Winners Devoted to Digital Privacy and Nuclear Activism

Martin Hellman was one of two computer scientists who won the prestigious Turing Award this week for pioneering work in encryption and digital security published nearly 40 years ago. But Hellman’s priorities have little to do with cryptography these days. Instead, he spends the bulk of his time warning the public of society’s potential nuclear demise.

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Nervana Systems Puts Deep Learning AI in the Cloud

Deep learning is Silicon Valley’s latest and greatest attempt at training artificial intelligence to understand the world by sifting through huge amounts of data. A startup called Nervana Systems aims to make AI based on deep learning neural networks even more widely available by turning it into a cloud service for any industry that has Big Data problems to solve.

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Quantum Computer Comes Closer to Cracking RSA Encryption

Quantum computers are often heralded as the future of smarter searching and lightning fast performance. But their amazing mathematical skills may also create grave security risks for data that has long been safely guarded by the premise that certain math problems are simply too complex for computers to solve.

Now computer scientists at MIT and the University of Innsbruck say they've assembled the first five quantum bits (qubits) of a quantum computer that could someday factor any number, and thereby crack the security of traditional encryption schemes.

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Monkeys Navigate a Wheelchair With Their Thoughts

Scientists at Duke University have demonstrated a wireless brain-machine interface (BMI) that allows monkeys to navigate a robotic wheelchair using their thoughts. This is the first long-term wireless BMI implant that has given high-quality signals to precisely control a wheelchair’s movements in real time.

“This is the first wireless brain-machine interface for whole-body locomotion,” says Miguel Nicolelis, professor of neuroscience at Duke who led the work published in the journal Scientific Reports. “Even severely disabled patients who cannot move any part of their body could be placed on a wheelchair and be able to use this device for mobility.”

Nicolelis and his colleagues pioneered brain-machine interfaces in a 1999 study on rats. Since then, researchers have done several demonstrations of primates using brain signals to control prosthetic arms, advanced devices, and computers, and even receive haptic signals

Despite those exciting advances, reliable, long-lasting implants that give high-quality signals have been lacking for human trials and use. 

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EUV Lithography's Prospects Are Brightening

After a hard slog, extreme ultraviolet (EUV) lithography seems to be closing in on a long-sought quarry: a light source bright enough to pattern chips cheaply and keep Moore’s Law marching along.

The technology, which uses 13.5-nanometer light instead of today’s 193-nanometer light, could—at least in the short term—allow chipmakers to create finer features without having to expose chips multiple times, a process that can add significantly to the expense of the manufacturing process.

But for years, EUV’s prospects were limited by the dimness of its light source. Unlike conventional lithography, which uses an ultraviolet laser, EUV generates its invisible light—just at the edge of the x-ray part of the spectrum—by turning tin into a plasma. ASML, which is developing EUV machines for the semiconductor industry, has put its support behind a particular approach called laser-produced plasma, which creates light by shooting 50,000 microscopic molten tin droplets per second across a vacuum chamber and vaporizing each one with a pulse of CO2 laser light.

At the SPIE Advanced Lithography conference in San Jose last week, ASML said it has pushed the limit of that light source to 200 W and aims to reach 250 W by the end of the year.

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5G Coming Sooner, Not Later

Things are moving at blistering speed in the world of next-generation 5G mobile communications—even though many mobile users have still or only recently upgraded to 4G LTE communications, and even while 4G continues to evolve.

Nevertheless, four of the telecom industry’s big hitters—Japan’s NTT Docomo, South Korea’s KT and SK Telecom, and Verizon in the United States—are not waiting for stragglers to catch up. Yesterday, at the annual Mobile World Congress in Barcelona, the carriers unveiled a plan to form the 5G Open Trial Specification Alliance with the aim of driving the technology forward. Meanwhile, Docomo and Sweden’s Ericsson announced that they achieved a cumulative 20-gigabit-per-second transmission speed with two connected 5G terminals in outdoor trials.

The four-party alliance seeks to hammer out agreements on technical fundamentals resulting from the companies’ individual 5G trials. They would then use their collective muscle to have the agreed upon specs “serve as a common, extendable platform for different 5G trial activity around the world,” as the announcement put it.

“In particular, we want to decide which 5G spectrum bands to use in a global industry,” Yoshihisa Kishiyama, Senior Research Engineer at Docomo’s 5G Laboratory, told IEEE Spectrum. “And we want to finalize 5G specifications by the end of 2018.”

If successful, this would help create standards for network equipment makers to follow, bringing the advent of fifth generation communications ever closer. Docomo, for one, has publicly committed itself to having 5G service up and running in time for the Tokyo Olympics in 2020.

As outlined by the International Telecommunications Union, 5G promises “a seamlessly connected society in the 2020 timeframe and beyond that brings together people along with things, data, applications, transport systems, and cities in a smart networked communications environment.”

To achieve all this, Docomo noted in a July 2014 White Paper, 5G would require data rates 100 times higher than today’s wireless networks offer, plus a reduction in latency to 1 millisecond, a 1,000-times increase in systems capacity, as well as a reduction in energy consumption. And with the coming avalanche of Internet-of-Things devices that will be continuously connected to cloud services, Docomo is targeting “a 100-fold increase in the number of simultaneously connected users compared to 4G LTE.”

It’s expected that 5G will need to utilize higher frequency spectrums ranging from 6 to 66 gigahertz. This would take it into the millimeter-wave band, which will enable multi-beam multiplexing and massive multi-input-output (MIMO) technologies.

So rather than broadcasting signals from a base station in all directions, individual signals can be transferred between individual terminals and a base station as required—and in crowded hot spots by means of a cluster of smaller antennas. This scenario should eliminate interference from nearby terminals and slowdowns in data speeds. It’s also expected to make better use of signal power and more efficient use of bandwidth.

In a trial last Sunday outside Docomo’s R&D Center in Yokosuka, just south of Tokyo, this multi-beam MIMO technology was used to transmit data with a cumulative 20-Gbps throughput. Docomo and Ericsson engineers set up four mini base-stations, each equipped with 64 antenna elements, to create one super-sensitive base station. Two Ericsson 5G prototype terminals, located 9 meters and 3 meters respectively from the base station were each able to simultaneously download over 10 Gbps over a 15-GHz wireless band.

In a separate trial on the same day, the companies successfully transmitted data at 10 Gbps over a distance of 70 meters from the base station and then at 9 Gbps over a distance of 120 meters.

“Our target [upon commercialization] is to achieve several gigabits per second in 2020 and over 10 gigabits per second after that,” says Kishiyama. He added that Docomo hopes to see the arrival of new 5G applications “earlier than 2020, so as to promote 5G before then.” But he would not say what these applications might be.


Virgin Galactic's New SpaceShipTwo Will Be Safer, But Will It Be Safe Enough?

Last week, Virgin Galactic unveiled a new version of its SpaceShipTwo, which is designed to carry paying customers to the edge of space. This new vehicle makes its debut more than a year after a devastating accident that took the life of co-pilot Michael Alsbury.

If the recovery from past spaceflight disasters is any guide, this craft will be flown in a far less risky mode, with more safety features incorporated into the hardware and more safety awareness inculcated into the human minds controlling it. But the real question is what will happen when the next vehicle rolls down the line, and how safe the company’s flights will be 5 or 10 years from now.

The Federal Aviation Administration’s minimalistic approach to regulating the safety of the space tourism industry was called into question in the wake of the Virgin Galactic accident. But the bulwark against future disaster doesn’t rest in federal regulations, codified checklists, or safety gadgets. Instead it rests where it always must, in the hearts and minds of the people who make daily decisions in support of the fabrication, testing, preparation, and operation of such machinery. It is that culture, now understandably sharpened by the still-fresh loss of a human life, that will be the most effective barrier against future accidents.

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