(Credit: iStockphoto)

Psychologists at the University of California, Santa Barbara have found evidence for the value of mind-wandering.

The researchers presented 145 undergraduate students with two “unusual uses” tasks that gave them two minutes to list as many uses as possible for everyday objects such as toothpicks, clothes hangers and bricks.

After the two minutes were over, participants were given a 12-minute break, during which they rested, undertook a demanding memory activity that required their full attention or engaged in an undemanding reaction-time activity known to elicit mind-wandering. A fourth group of students had no break. All participants were then given four unusual-uses tasks, including the two that they had completed earlier.

Those students who had done the undemanding activity performed an average of 41% better at the repeated tasks the second time they tried them. By contrast, students in the other three groups showed no improvement.

“We’ve traditionally found that rapid-eye-movement sleep grants creative insight. That allowing the mind to wander does the same is absolutely fascinating. I think they are on to something really interesting here,” says Sara Mednick, a psychologist at the University of California, Riverside.

Participants who engaged in the undemanding task did not do any better than others on unusual-uses tasks that they encountered for the first time in the second round. “The implication is that mind-wandering was only helpful for problems that were already being mentally chewed on. It didn’t seem to lead to a general increase in creative problem-solving ability,” says Baird.

The upside of zoning out

As well as revealing that breaks on their own do not encourage creative thinking, Baird’s work suggests an explanation for one of psychology’s great mysteries: why we zone out.

From an evolutionary perspective, mind-wandering seems totally counterproductive and has been viewed as dysfunctional because it compromises people’s performance in physical activities. However, Baird’s work shows that allowing the brain to enter this state when it is considering complex problems can have real benefits. Zoning out may have aided humans when survival depended on creative solutions.

“There is a real possibility that mind-wandering is so common because evolution has selected for it over time, but before we can come to that conclusion we have to ascertain whether it’s genetically determined,” says Kounios.

Ref.: Baird, B., et al., Psychological Science, in press

Transmission electron microscopy (TEM) images showing quantum dots after micelle encapsulation (Credit: Ling Ye, et al./Nature Nanotechnology)

A pioneering study to gauge the toxicity of quantum dots in primates has found the tiny luminescent crystals are safe over a one-year period, a hopeful outcome for doctors and scientists seeking new ways to battle diseases like cancer through nanomedicine.

In the study, scientists found that four rhesus monkeys injected with cadmium-selenide quantum dots remained in normal health over 90 days. Blood and biochemical markers stayed in typical ranges, and major organs developed no abnormalities. The animals didn’t lose weight. Two monkeys observed for an additional year also showed no signs of illness.

Quantum dots are tiny luminescent crystals that glow brightly in different colors. Medical researchers are eyeing the crystals for use in image-guided surgery, light-activated therapies and sensitive diagnostic tests. Cadmium selenide quantum dots are among the most studied, with potential applications not only in medicine, but as components of solar cells, quantum computers, light-emitting diodes and more.

The new toxicity study — completed by the University at Buffalo, the Chinese PLA General Hospital, China’s ChangChun University of Science and Technology, and Singapore’s Nanyang Technological University — begins to address the concern of health professionals who worry that quantum dots may be dangerous to humans.

The authors caution, however, that more research is needed to determine the nanocrystals’ long-term effects in primates; most of the potentially toxic cadmium from the quantum dots stayed in the liver, spleen and kidneys of the animals studied over the 90-day period.

“This is the first study that uses primates as animal models for in vivo studies with quantum dots,” said paper coauthor Paras Prasad, UB professor of chemistry and medicine, and executive director of UB’s Institute for Lasers, Photonics and Biophotonics (ILPB). “So far, such toxicity studies have focused only on mice and rats, but humans are very different from mice. More studies using animal models that are closer to humans are necessary.”

The cadmium build-up, in particular, is a serious concern that warrants further investigation, said Ken-Tye Yong, a Nanyang Technological University assistant professor who began working with Prasad on the study as a postdoctoral researcher at UB.

Because of that concern, the best in-vivo applications for cadmium-selenide quantum dots in medicine may be the ones that use the crystals in a limited capacity, said Mark Swihart, a third coauthor and a UB professor of chemical and biological engineering. Image-guided surgery, which could involve a single dose of quantum dots to identify a tumor or other target area, falls into this category.

Ref.: Ling Ye, et al. A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots. Nature Nanotechnology, 20 May 2012 DOI: 10.1038/nnano.2012.74

Polling current position and channel-state-information (CSI) (credit: Neil Mehta, Alexandra Duel-Hallen, Wenye Wang)

Researchers from North Carolina State University have devised a method to improve the quality and efficiency of data transmission in Mobile ad hoc networks (MANETs).

MANETs allow people in multiple, rapidly-moving vehicles to communicate with each other, such as in military or emergency-response situations.

“Our goal was to get the highest data rate possible, without compromising the fidelity of the signal,” says Dr. Alexandra Duel-Hallen, a professor of electrical and computer engineering at NC State and co-author of a paper describing the work.

Transmitting data within MANETs is challenging because every node that transmits and receives data is in motion — and the faster they are moving, the harder it is for the network to identify effective relay “paths” for transmitting data. This is because the power of the data-transmission channels fluctuates much more rapidly at high speed.

In other words, a transmitter may try to send a message through Relay A, because Relay A has a strong signal. However, because the transmitter and Relay A are both moving quickly, Relay A’s signal might be weak by the time the message actually gets there. And a weak signal could result in the message being garbled.

To address this issue, researchers developed a method to improve the ability of each node in the network to select the best path for relaying data, as well as the best for transmitting the data that ensures reliable reception.

When a node needs to transmit a message, it first measures the strength of transmissions it is receiving from potential relays. Those data are then plugged in to an algorithm that predicts which relay will be strongest when the message is transmitted.

By predicting the strength of the relay, the algorithm also tells the node the rate at which it should transmit the data. If it tries to send too much data too quickly, the data quality will suffer — the data could be compromised. If the rate of data transmission is too slow, the network won’t be operating at peak efficiency.

The research was supported by the National Science Foundation and the U.S. Army Research Office.

Ref.: Neil Mehta, Alexandra Duel-Hallen, Wenye Wang, Enabling Adaptive Rate and Relay Selection for 802.11 Mobile Ad Hoc Networks, presented at the IEEE’s International Conference on Communications in Ottawa, June 10-15, 2012

The Leap is a small iPod-sized USB peripheral that creates a 3D interaction space of 8 cubic feet to precisely interact with and control software on your laptop or desktop computer. (Credit: Leap Motion)

Leap Motion is unveiling its Leap 3D motion control system, Technology Review Hello World reports.

Leap Motion appears to outrank Kinect in terms of its capability. The technology, reports CNET, can detect motion with up to a hundredth of a millimeter accuracy; it’s nuanced enough to detect fingers, for instance, enabling the possibility of touch-free pinch-to-zoom.

When the device is available for commercial release, it’s expected to retail for around $70. The device itself is fairly simple — a small USB input device (plus an advanced software platform).

There’s a range of possibilities for the technology: consumers might use it to browse the web; engineers could mold virtual clay; designers could draw precisely in 2-D or 3-D; and new gaming possibilities could evolve.

Leap Motion is looking for a “few hundred” developers to get involved with their tech, and soon intend to send out as many as 20,000 free developer kits when it’s officially released — in 2013, according to reports.

Schematic of a silicon nanowire (gray) hooked up by two gold electrodes (yellow) (credit: Pengyu Fan et al./Nature Photonics)

Stanford University and the University of Pennsylvania engineers have used “plasmonic cloaking” to create a device that can see without being seen.

It is the first example of what the researchers describe as a new class of devices that control the flow of light at the nanoscale to produce both optical and electronic functions.

At the heart of the device are silicon nanowires covered by a thin cap of gold. By adjusting the ratio of metal to silicon — a technique the engineers refer to as tuning the geometries — they capitalize on favorable nanoscale physics in which the reflected light sources from the two materials cancel each other to make the device invisible.

Pengyu Fan, the lead author of a paper demonstrating the new device, is a doctoral candidate in materials science and engineering at Stanford University working in Professor Mark Brongersma’s group.

Cloak of invisiblity

Light detection is well known and relatively simple. Silicon generates electrical current when illuminated and is common in solar panels and light sensors today. The Stanford device, however, is a departure in that for the first time it uses a relatively new concept known as plasmonic cloaking to render the device invisible.

SEM image of a 50-nm-diameter silicon nanowire with a 20-nm-thick gold "cover" (credit: Pengyu Fan et al./Nature Photonics)

The field of plasmonics studies how light interacts with metal nanostructures and induces tiny oscillating electrical currents along the surfaces of the metal and the semiconductor. These currents, in turn, produce scattered light waves.

By carefully designing their device — by tuning the geometries — the engineers have created a plasmonic cloak in which the scattered light from the metal and semiconductor cancel each other perfectly through a phenomenon known as destructive interference.

The rippling light waves in the metal and semiconductor create a separation of positive and negative charges in the materials — a dipole moment, in technical terms. The key is to create a dipole in the gold that is equal in strength but opposite in sign to the dipole in the silicon. When equally strong positive and negative dipoles meet, they cancel each other and the system becomes invisible.

“We found that a carefully engineered gold shell dramatically alters the optical response of the silicon nanowire,” said Fan. “Light absorption in the wire drops slightly — by a factor of just four — but the scattering of light drops by 100 times due to the cloaking effect, becoming invisible.”

“It seems counterintuitive,” said Brongersma, “but you can cover a semiconductor with metal — even one as reflective as gold — and still have the light get through to the silicon. As we show, the metal not only allows the light to reach the silicon where we can detect the current generated, but it makes the wire invisible, too.”

Plasmonically cloaked pixels

The engineers have shown that plasmonic cloaking is effective across much of the visible spectrum of light and that the effect works regardless of the angle of incoming light or the shape and placement of the metal-covered nanowires in the device. They likewise demonstrate that other metals commonly used in computer chips, like aluminum and copper, work just as well as gold.

To produce invisibility, what matters above all is the tuning of metal and semiconductor.

“If the dipoles do not align properly, the cloaking effect is lessened, or even lost,” said Fan. “Having the right amount of materials at the nanoscale, therefore, is key to producing the greatest degree of cloaking.”

In the future, the engineers foresee application for such tunable, metal-semiconductor devices in many relevant areas, including solar cells, sensors, solid-state lighting, chip-scale lasers, and more.

In digital cameras and advanced imaging systems, for instance, plasmonically cloaked pixels might reduce the disruptive cross-talk between neighboring pixels that produces blur. It could therefore lead to sharper, more accurate photos and medical images.

“We can even imagine reengineering existing opto-electronic devices to incorporate valuable new functions and to achieve sensor densities not possible today,” concluded Brongersma. “There are many emerging opportunities for these photonic building blocks.”

Ref.: Pengyu Fan et al., An invisible metal–semiconductor photodetector, Nature Photonics, 2012, DOI: 10.1038/nphoton.2012.108

Under ultraviolet light, petri dishes containing cells glow red or green depending upon the orientation of a specific section of genetic code inside the cells' DNA. The section of DNA can be flipped back and forth using the RAD technique. (Credit: Stanford University)

A method for repeatedly encoding, storing and erasing digital data within the DNA of living cells, using natural enzymes adapted from bacteria — the genetic equivalent of a bit — has been developed by Stanford University scientists in the Department of Bioengineering, a joint effort of the School of Engineering and the School of Medicine.

“Programmable data storage within the DNA of living cells would seem an incredibly powerful tool for studying cancer, aging, organismal development and even the natural environment,” said Stanford assistant professor Drew Endy. Researchers could count how many times a cell divides, for instance, and that might someday give scientists the ability to turn off cells before they turn cancerous.

Non-volatile memory

Architecture, mechanisms, and operation of a recombinase addressable data (RAD) module. The DNA inversion RAD module is driven by two generic transcription input signals, set and reset. A set signal drives expression of integrase that inverts a DNA element serving as a genetic data register. Flipping the register converts flanking attB and attP sites to attL and attR sites, respectively. A reset signal drives expression of integrase and excisionase and restores both register orientation and the original flanking attB and attP sites. The register itself encodes a constitutive promoter which initiates strand-specific transcription. Following successful set or reset operations, mutually exclusive transcription outputs “1” or “0” are activated, respectively. For the RAD module developed here, a “1” or “0” register state produces red or green fluorescent protein, respectively. (Credit: Stanford University/PNAS)

In the computer world, their work would form the basis of what is known as non-volatile memory — data storage that can retain information without consuming power. In biotechnology, it is known as “recombinase-mediated DNA inversion,” after the enzymatic processes used to cut, flip and recombine DNA within the cell.

The team calls its device a “recombinase addressable data” module, or RAD for short. They used RAD to modify a particular section of DNA with microbes that determines how the one-celled organisms will fluoresce under ultraviolet light. The microbes glow red or green depending upon the orientation of the section of DNA. Using RAD, the engineers can flip the section back and forth at will.

To make their system work, the team had to control the precise dynamics of two opposing proteins, integrase and excisionase, within the microbes. “Previous work had shown how to flip the genetic sequence irreversibly — in one direction through the expression of a single enzyme,”  said Stanford postdoctoral scholar Jerome Bonnet, “but we needed to reliably flip the sequence back and forth, over and over, in order to create a fully reusable binary data register.”

The researchers found it was fairly easy to flip a section of DNA in either direction. “But we discovered time and again that most of our designs failed when the two proteins were used together within the same cell,” said Endy. “Ergo: Three years and 750 tries to get the balance of protein levels right.”

Going from bit to byte

Bonnet has now tested RAD modules in single microbes that have doubled more than 100 times and the switch has held. He has likewise switched the latch and watched a cell double 90 times, and set it back. The latch will even store information when the enzymes are not present. In short, RAD works. It is reliable and it is rewritable.

“One of the coolest places for computing,” Endy said, “is within biological systems.” His goal is to go from the single bit he has now to eight bits — or a “byte” — of programmable genetic data storage.

To get there, however, science will need many new tools for engineering biology, he added, but it will not be easy. “Such systems will likely be 10 to 50 times more complicated than current state-of-the-art genetic engineering projects,” he said. “We’re probably looking at a decade from when we started to get to a full byte.

The research was funded by the National Science Foundation’s Synthetic Biology Engineering Research Center, and by fellowship grants from Stanford’s Center for Longevity and its Bio-X program.

Ref.: Jerome Bonnet, Pakpoom Subsoontorn, and Drew Endy, Rewritable digital data storage in live cells via engineered control of recombination directionality, Proceedings of the National Academy of Sciences, 2012 DOI: 10.1073/pnas.1202344109 (open access)

Energy dashboard (credit: AlertMe)

AlertMe, the smart home tech company has sealed a deal with British Gas to provide a personalized energy efficiency advice service to UK customers with smart meters.

Smart meters will have a display that shows customers how much energy they are using. The AlertMe service breaks down the information for comparison with similar households, actionable recommendations (like getting insulation or double glazing to help keep in heat) and generally suggest ways in which customers can save money and not waste so much energy.

The free cloud-based service is being trialed with up to 10,000 homes during the summer and rolled out widely from the autumn. Smart meters from British Gas will be rolled out to all homes in the UK over the next seven years. Meanwhile, the Alertme system can be added to older gas meters.

Heating display (credit: AlertMe)

(Credit: Apple)

Apple has finalized the proposed design of its futuristic “spaceship” campus, featuring a rooftop with one of the biggest corporate solar installations in the entire world, to be operational by 2015.

See also: Apple plans new ‘spaceship’-like campus

SpaceX Falcon 9 Launches: The SpaceX Falcon 9 rocket soared into space from Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida, carrying the Dragon capsule to orbit at 3:44 a.m. EDT on Tuesday, May 22, 2012 (credit: NASA)

SpaceX‘s Falcon 9 rocket and Dragon spacecraft lifted off Tuesday from Cape Canaveral Air Force Station in Florida at 3:44 a.m. EDT, kicking off the second demonstration mission for NASA’s Commercial Orbital Transportation Services (COTS) program/

“Today marks the beginning of a new era in exploration; a private company has launched a spacecraft to the International Space Station that will attempt to dock there for the first time,” NASA Administrator Charles Bolden said.

The Dragon capsule will conduct a series of checkout procedures to test and prove its systems, including the capability to rendezvous and berth with the International Space Station.

On Thursday, May 24, Dragon will perform a flyby of the space station at a distance of approximately 1.5 miles to validate the operation of sensors and flight systems necessary for a safe rendezvous and approach. Live NASA TV coverage beginning at 2:30 a.m.

Following analysis of the flyby by NASA and SpaceX managers, the Dragon capsule will be cleared to rendezvous and berth with the space station on Friday, May 25, marking the first time a commercial company has attempted this feat. The Expedition 31 crew on board the station will use the orbiting complex’s robotic arm to capture Dragon and install it on the bottom side of the Harmony node. NASA TV will provide live coverage beginning at 2 a.m.

SpaceX and Orbital Sciences, which will perform its own test flight later this year, have been working under NASA’s COTS program, which provides investments to stimulate the commercial space industry in America. Once the companies have successfully completed their test flights, they will begin delivering regular cargo shipments to the station.

NASA also is developing the Orion spacecraft and Space Launch System (SLS), a crew capsule and heavy-lift rocket that will provide an entirely new capability for human exploration beyond low Earth orbit. Designed to be flexible for launching spacecraft for crew and cargo missions, SLS and Orion will expand human presence beyond low Earth orbit and enable new missions of exploration across the solar system.

(Credit: Google)

Comcast’s plans to do away with its 250 GB data cap and charge users based upon usage marks the end of an era for cable TV providers, and for the online video industry, TechCrunch reports.

So.cl (credit: Microsoft)

Over the weekend, Microsoft quietly launched an experimental social network called So.cl — a mix between Google+ and Storify.

You can search for information about a particular topic, then compile the best results — textual content, images and videos — into a single document.

So.cl is initially targeted to students. It may end up being useful as an academic tool, but it’s unlikely to get traction as a mainstream social network. Here’s why…

Researchers demonstrated quantum teleportation between La Palma and Tenerife, a distance of 143 km. (credit: Institute for Quantum Optics and Quantum Information)

Anton Zeilinger’s group (Institute for Quantum Optics and Quantum Information at the University of Vienna) has just submitted an arXiv paper claiming that they’ve demonstrated “quantum teleportation“ over a distance of 143 km (89 miles) in the Canary Islands. If confirmed, this sets a new world’s distance record in quantum teleportation, and also sets the stage for a future global quantum network for secure satellite communications.

Experiment overview for entanglement based quantum communication over 144 km. (credit: Institute for Quantum Optics and Quantum Information)

On May 9, researchers at the University of Science and Technology of China in Shanghai claimed that they had demonstrated quantum teleportation at a distance of 97 km (60 mi) across a lake in China. The previous published distance record was 16 km.

Quantum teleportation is actually not about teleporting matter — it’s the process of transferring the exact information about a particle from one place to another, using quantum entanglement, without the particle traveling through the intervening space.

In a related development, Space-QUEST, Zeilinger’s project on quantum entanglement for space experiments, demonstrated the exchange of a single photon between a low-Earth-orbit satellite and an Earth-based telescope in March 2008.

This wasn’t active communications, because the satellite only had a mirror, no quantum laser source. Their next step would be to install an active quantum laser on an external payload of the International Space Station, the researchers say.

Global space-based quantum networks

These new research projects validate the ability to send and receive photons under the same kinds of atmospheric interference conditions that would be required for a link between the earth and an orbiting satellite.

Successful demonstration of quantum entanglement at these distances is important as proof-of-concept for future space-based, global quantum networks, and to test the limits of entanglement at relativistic distances (in outer space). A key question: does entanglement remain valid at these length scales, or is it affected by gravity or physical distance?

In that connection, DARPA has just released a Broad Agency Announcement (BAA) soliciting “macroscopic quantum communications proposals which can combine the security of quantum communications with the distances/rates of macroscopic telecommunications. Proposed research should investigate innovative approaches that enable revolutionary advances in secure quantum communications.”

The DARPA announcement calls for some serious out-of-the-box thinking. The Chinese demonstration of quantum teleportation confirmed only 1171 teleported photons in four hours, experiencing a loss of 35–53 dB at a distance of 97 km.  The Austrian demonstration confirmed only 605 teleported photons in about 6.5 hours, experiencing a loss of 28–39 dB at a distance of 143 km.

Contrast that with the new DARPA program: they’re asking for researchers to demonstrate sustained transmission of secure quantum key rates of 1-10 Gigabits per second — at distances of 1,000–10,000 km — a real quantum leap (pun intended).

And they’re asking for these communications to be insensitive to the lossy, environmental decoherence that a dirty atmosphere presents to any experiment. According to DARPA: “Current techniques for quantum communication are highly sensitive to loss, with an increase in loss leading to a corresponding drop in bit rate (e.g., 10 dB of loss results in a factor of 10 decrease in secure bit rate). Successful programs are expected to present a method for decoupling loss from secure bit rate.”

The program has two secondary goals: to conclusively demonstrate that secure quantum communications can be extended to entirely new domains,  even underwater and through dirty air, and to extend macroscopic quantum communications to entirely new domains beyond the realm of key distribution.

Ref.: X. Ma et al., Quantum teleportation using active feed-forward between two Canary Islands, arxiv.org/pdf/1205.3909.pdf

Ref.: Juan Yin et al., Teleporting Independent Qubits Through A 97 Km Free-Space Channel, arxiv.org/abs/1205.2024

(Credit: Peter van der Sluijs/Wikimedia Commons)

Exercise clears the mind. It gets the blood pumping and more oxygen is delivered to the brain. But Dartmouth’s David Bucci thinks there is much more going on.

“In the last several years there have been data suggesting that neurobiological changes are happening — [there are] very brain-specific mechanisms at work here,” says Bucci, an associate professor in the Department of Psychological and Brain Sciences.

From his studies, Bucci and his collaborators have revealed important new findings:

• The effects of exercise are different on memory as well as on the brain, depending on whether the exerciser is an adolescent or an adult.
• A gene has been identified which seems to mediate the degree to which exercise has a beneficial effect. This has implications for the potential use of exercise as an intervention for mental illness.

Bucci began his pursuit of the link between exercise and memory with attention deficit hyperactivity disorder (ADHD), one of the most common childhood psychological disorders. Bucci is concerned that the treatment of choice seems to be medication.

“The notion of pumping children full of psycho-stimulants at an early age is troublesome,” Bucci cautions. “We frankly don’t know the long-term effects of administering drugs at an early age—drugs that affect the brain—so looking for alternative therapies is clearly important.”

Anecdotal evidence from colleagues at the University of Vermont started Bucci down the track of ADHD. Based on observations of ADHD children in Vermont summer camps, athletes or team sports players were found to respond better to behavioral interventions than more sedentary children. While systematic empirical data is lacking, this association of exercise with a reduction of characteristic ADHD behaviors was persuasive enough for Bucci.

Coupled with his interest in learning and memory and their underlying brain functions, Bucci and teams of graduate and undergraduate students embarked upon a project of scientific inquiry, investigating the potential connection between exercise and brain function. They published papers documenting their results, with the most recent now available in the online version of the journal Neuroscience.

Bucci is quick to point out that “the teams of both graduate and undergraduates are responsible for all this work, certainly not just me.” Michael Hopkins, a graduate student at the time, is first author on the papers.

Early on, laboratory rats that exhibit ADHD-like behavior demonstrated that exercise was able to reduce the extent of these behaviors. The researchers also found that exercise was more beneficial for female rats than males, similar to how it differentially affects male and female children with ADHD.

Moving forward, they investigated a mechanism through which exercise seems to improve learning and memory. This is “brain derived neurotrophic factor” (BDNF) and it is involved in growth of the developing brain. The degree of BDNF expression in exercising rats correlated positively with improved memory, and exercising as an adolescent had longer lasting effects compared to the same duration of exercise, but done as an adult.

“The implication is that exercising during development, as your brain is growing, is changing the brain in concert with normal developmental changes, resulting in your having more permanent wiring of the brain in support of things like learning and memory,” says Bucci. “It seems important to [exercise] early in life.”

Bucci’s latest paper was a move to take the studies of exercise and memory in rats and apply them to humans. The subjects in this new study were Dartmouth undergraduates and individuals recruited from the Hanover community.

Bucci says that, “the really interesting finding was that, depending on the person’s genotype for that trophic factor [BDNF], they either did or did not reap the benefits of exercise on learning and memory. This could mean that you may be able to predict which ADHD child, if we genotype them and look at their DNA, would respond to exercise as a treatment and which ones wouldn’t.”

Bucci concludes that the notion that exercise is good for health including mental health is not a huge surprise. “The interesting question in terms of mental health and cognitive function is how exercise affects mental function and the brain.” This is the question Bucci, his colleagues, and students continue to pursue.

Ref.: M.E. Hopkins, F.C. Davis, M.R. VanTieghem, P.J. Whalen, D.J. Bucci, Differential effects of acute and regular physical exercise on cognition and affect, Neuroscience, 2012, DOI: 10.1016/j.neuroscience.2012.04.056

(Credit: Ivan Martinez/Wikimedia Commons)

Do you feel guilty when you read a newspaper?

You probably should, according to BuzzFeed co-founder Jonah Peretti, who has “a moral issue” with print publishing and its environmental impact.

(Credit: Allwinner)

The MK802 is available from AliExpress for $74, or less if you order in bulk. It has a 1.5 GHz Allwiner A10 processor, 512MB of RAM, 4GB of storage, USB port, microSD card slot, and HDMI port. It also features 802.11b/g WiFi and support for HD video playback in a variety of media formats.

It ships with Google Android 4.0 software, but theoretically you should be able to install Ubuntu or other operating systems.

Zero Devices is preparing to launch the Z802 which looks nearly identical, except for the Zero Devices logo on the front of the device, and available for pre-order from some sources for about $76.

New results from NASA's NEOWISE survey find that more potentially hazardous asteroids, or PHAs, are closely aligned with the plane of our solar system than previous models suggested, coming within 5 million miles (about 8 million kilometers) of Earth (credit: NASA/JPL-Caltech)

There are roughly 4,700 potentially hazardous asteroids (PHAs) with diameters larger than 330 feet (about 100 meters). So far, an estimated 20 to 30 percent of these objects have been found, according to observations from NASA’s Wide-field Infrared Survey Explorer (WISE), which have led to the best assessment yet of our solar system’s population of potentially hazardous asteroids.

Potentially hazardous asteroids are a subset of the larger group of near-Earth asteroids. The PHAs have the closest orbits to Earth’s, coming within five million miles (about eight million kilometers), and they are big enough to survive passing through Earth’s atmosphere and cause damage on a regional, or greater, scale.

The new results come from the asteroid-hunting portion of the WISE mission, called NEOWISE. The project sampled 107 PHAs to make predictions about the entire population as a whole. Findings indicate there are roughly 4,700 PHAs, plus or minus 1,500, with diameters larger than 330 feet (about 100 meters). So far, an estimated 20 to 30 percent of these objects have been found.

While previous estimates of PHAs predicted similar numbers, they were rough approximations. NEOWISE has generated a more credible estimate of the objects’ total numbers and sizes. It suggests that about twice as many PHAs as previously thought are likely to reside in “lower-inclination” orbits, which are more aligned with the plane of Earth’s orbit.

In addition, these lower-inclination objects appear to be somewhat brighter and smaller than the other near-Earth asteroids that spend more time far away from Earth. A possible explanation is that many of the PHAs may have originated from a collision between two asteroids in the main belt lying between Mars and Jupiter. A larger body with a low-inclination orbit may have broken up in the main belt, causing some of the fragments to drift into orbits closer to Earth and eventually become PHAs.

This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). PHAs are a subset of the near-Earth asteroids (NEAs). They have the closest orbits to Earth's orbit, coming within 5 million miles (about 8 million kilometers), and they are large enough to survive passage through Earth's atmosphere and cause damage on a regional, or greater, scale. (Credit: NASA/JPL-Caltech)

Asteroids with lower-inclination orbits would be more likely to encounter Earth and would be easier to reach. The results therefore suggest more near-Earth objects might be available for future robotic or human missions.

“NASA’s NEOWISE project, which wasn’t originally planned as part of WISE, has turned out to be a huge bonus,” said Amy Mainzer, NEOWISE principal investigator, at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Everything we can learn about these objects helps us understand their origins and fate. Our team was surprised to find the overabundance of low-inclination PHAs. Because they will tend to make more close approaches to Earth, these targets can provide the best opportunities for the next generation of human and robotic exploration.”

The discovery that many PHAs tend to be bright says something about their composition; they are more likely to be either stony, like granite, or metallic. This type of information is important in assessing the space rocks’ potential hazards to Earth. The composition of the bodies would affect how quickly they might burn up in our atmosphere if an encounter were to take place.

Dubai Panorama (credit: Stephen Wiltshire)

How can we explain “acquired savants” — people with extraordinary talent who’ve miraculously developed artistic, musical, or mathematical abilities as a result of a brain injury, or temporarily from a transcranial magnetic stimulation (TMS) session — since they weren’t born with the talent and didn’t learn it later?

For example, how is it that somebody like Derek Amato (video below), who’d never demonstrated any musical talent before hitting his head at the bottom of a pool, could suddenly handle jazz and classical pieces of astounding complexity without training?

Darold A. Treffert, M.D., Clinical Professor of Psychiatry at the University of Wisconsin School of Medicine and consultant for the movie Rain Man, speculates that it could be the result of  what he calls “genetic memory” (“ancestral memory”) that is triggered by rewiring of the brain to compensate for the injury.

See also:

Savant Syndrome (Darold Treffert website)

Islands of Genius: The Bountiful Mind of the Autistic, Acquired, and Sudden Savant, Darold Treffert and Jessica Kingsley Publishers, 2011

“Ancestral” or “Genetic” Memory: Factory Installed Software Darold Treffert, 2011

Conversations on Creativity with Darold Treffert, Psychology Today, April 27, 2011 (open access)

Augmenting Cognition,  Idan Segev and Henry Markram, EFPL Press, 2011

Stephen Wiltshire MBE

While the article in The Atlantic does not cover new findings, it summarizes some of the key ideas well. — Ed.

(Credit: Julius Schorzman/Wikimedia Commons)

Older adults who drank coffee — caffeinated or decaffeinated — had a lower risk of death overall than others who did not drink coffee, according a study by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, and AARP.

Coffee drinkers were less likely to die from heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections, although the association was not seen for cancer.

These results from a large study of older adults were observed after adjustment for the effects of other risk factors on mortality, such as smoking and alcohol consumption.

Researchers caution, however, that they can’t be sure whether these associations mean that drinking coffee actually makes people live longer.

Neal Freedman, Ph.D., Division of Cancer Epidemiology and Genetics, NCI, and his colleagues examined the association between coffee drinking and risk of death in 400,000 U.S. men and women ages 50 to 71 who participated in the NIH-AARP Diet and Health Study. Information about coffee intake was collected once by questionnaire at study entry in 1995-1996. The participants were followed until the date they died or Dec. 31, 2008, whichever came first.

The researchers found that the association between coffee and reduction in risk of death increased with the amount of coffee consumed. Relative to men and women who did not drink coffee, those who consumed three or more cups of coffee per day had approximately a 10 percent lower risk of death. Coffee drinking was not associated with cancer mortality among women, but there was a slight and only marginally statistically significant association of heavier coffee intake with increased risk of cancer death among men.

“Coffee is one of the most widely consumed beverages in America, but the association between coffee consumption and risk of death has been unclear. We found coffee consumption to be associated with lower risk of death overall, and of death from a number of different causes,” said Freedman. “Although we cannot infer a causal relationship between coffee drinking and lower risk of death, we believe these results do provide some reassurance that coffee drinking does not adversely affect health.”

The investigators caution that coffee intake was assessed by self-report at a single time point and therefore might not reflect long-term patterns of intake. Also, information was not available on how the coffee was prepared (espresso, boiled, filtered, etc.); the researchers consider it possible that preparation methods may affect the levels of any protective components in coffee.

“The mechanism by which coffee protects against risk of death — if indeed the finding reflects a causal relationship — is not clear, because coffee contains more than 1,000 compounds that might potentially affect health,” said Freedman. “The most studied compound is caffeine, although our findings were similar in those who reported the majority of their coffee intake to be caffeinated or decaffeinated.”

Ref.: Neal D. Freedman et al., Association of Coffee Drinking with Total and Cause-Specific Mortality, New England Journal of Medicine, 2012, DOI: 10.1056/NEJMoa1112010

Wireless power transfer experimental setup (credit: Z. Pantic and S. Lukic)

Researchers from North Carolina State University (NC State) have developed a new way to fine-tune wireless power transfer (WPT) receivers, making the systems more efficient and functional. WPT systems hold promise for charging electric vehicles, electronic devices, and other technologies.

Researchers have previously shown that it is possible to transmit power wirelessly by using magnetic resonance, but even minor changes in how the transmitter or receiver is tuned can result in faulty power transmission when the resonant frequencies don’t match.

A new prototype developed at NC State addresses the problem by automatically and precisely re-tuning the receivers in WPT systems. The researchers focused on receivers because methods already exist that allow researchers to use electronics to precisely tune the transmitters.

“We’re optimistic that this technology moves us one step closer to realizing functional WPT systems that can be used in real-world circumstances,” says Dr. Srdjan Lukic, an assistant professor of electrical and computer engineering at NC State and co-author of a paper on the research.

How it works

Structure of the WPT system

WPT systems work by transmitting magnetic waves on a specific frequency from a transmitter to a receiver. These magnetic waves interact with a coil in the receiver to induce an electric current. If the coil is tuned so that its resonant frequency matches the frequency of the magnetic waves, the current it produces is amplified.

However, if the receiver and the transmitter frequencies differ even slightly, the system becomes inefficient and doesn’t transfer a significant amount of power. This is a problem because many factors can affect the tuning of a receiver or transmitter, such as temperature or proximity to other magnetic objects. In other words, a hot summer day could wreak havoc on the tuning of a receiver.

The engineers developed an electronic prototype that incorporates additional circuitry into the receiver that does two things: it injects small amounts of reactive power into the receiver coil as needed to maintain its original resonant frequency; and if the transmitter’s tuning changes, the prototype can read the trace amount of current being transmitted and tune the receiver’s frequency to match. The effect is similar to autotuning vocal pitch in pop music.

“Because we are using electronics to inject reactive power into the receiver coil, we can be extremely precise when tuning the receiver,” Lukic says. “This degree of fine-tuning maximizes the efficiency of the WPT system. The next step is to try incorporating this work into technology that can be used to wirelessly charge electric vehicles.”

Z. Pantic, S. Lukic, Framework and Topology for Active Tuning of Parallel Compensated Receivers in Wireless Power Transfer Systems, IEEE Transactions on Power Electronics, 2012, DOI: 10.1109/TPEL.2012.2196055

New York City Stock Exchange (credit: Norbert Nagel/Wikimedia Commons)

World stocks fell Friday after credit downgrades slapped on Spanish banks unnerved investors already worried about the stability of the 17-country euro currency union.

Political turmoil in Greece has increased the likelihood that it could leave the 17-country monetary union, a move that could have ripple effects throughout Europe and the world’s financial markets.

Markets were jolted by Moody’s downgrade Thursday of 16 Spanish banks, said Jackson Wong, vice president at Tanrich Securities in Hong Kong.

In currencies, the euro fell to $1.2686 from $1.2714 late Thursday in New York. The dollar rose slightly to 79.30 yen from 79.28 yen.

Network showing genes that are regulated by FOS and SP1 genes. It contains many literature-associated and highly correlated genes. Genes reported in the literature associated with pancreatic cancer survival are represented with larger circles. The absolute correlation coefficient of gene expression with survival in the screening dataset is shown in red. (Credit: C. Winter et al./PLoS)

The algorithm Google uses to rank search results can now scan cancers to see which molecules best reveal the risks patients face, researchers have found, Txchnologist reports.

By seeing how proteins are linked in a kind of molecular Facebook, search engine algorithms could also help unearth new targets for drugs to help combat tumors, investigators added.

NetRank

The algorithm Google uses to rank which results pop up first in search queries, PageRank, orders results based on how other web pages are connected to them via hyperlinks.

Researchers modified PageRank to develop NetRank, which scans how genes and proteins in a cell are similarly connected through a network of interactions with their neighbors — “‘friends’ in the social network analogy,” said researcher Christof Winter, a medical doctor and computational biologist at Lund University in Sweden.

The investigators focused on pancreatic cancer, the most common form of which, pancreatic ductal adenocarcinoma, accounts for approximately 130,000 deaths each year in Europe and the United States. Very few tests exist to find out a prognosis for the disease — how it might progress, whether a patient might live or die.

The researchers used NetRank on about 20,000 proteins to see which ones were the best indicators for survival. They identified seven proteins that could help assess how aggressive a patient’s tumor is and guide clinicians to decide if the prognosis was worth trying chemotherapy or not.

As to how accurate prognoses based on these seven markers were, roughly speaking, “our markers are right in two-thirds of cases, and wrong in one-third,” Winter said. These markers were 6 to 9 percent more accurate at prognoses compared with those relying on conventional clinical parameters.

Monte Carlo cross-validation workflow to evaluate the accuracy of methods for ranking genes for outcome prediction (credit: C. Winter et al./PLoS)

In addition to improving prognoses of cancer, this research could also help identify new targets to help destroy tumors.

Currently Winter and his colleagues are analyzing DNA and RNA data from breast cancer. The hope is “to develop a DNA-based prognostic blood test for breast cancer patients,” he said.

Ref.: Christof Winter et al., Google Goes Cancer: Improving Outcome Prediction for Cancer Patients by Network-Based Ranking of Marker Genes, PLoS Computational Biology, 2012, DOI: 10.1371/journal.pcbi.1002511 (open access)

“Moving away from copper lines is an example of abandoning obsolete technology and embracing technology that is faster, better, cheaper and more convenient,” said Rob Frieden, Pioneers Chair in Cable Television and professor of telecommunications and law. “But the risk is that we may be creating a digital divide — not necessarily a divide between the rich and poor, but between the information rich and information poor.”

Telephone companies are lobbying for government regulators to free them of their traditional role as a public utility, citing the convergence and availability of new communication technologies, such as cellular phones and fiber optic cable, that make copper-based telephone land lines obsolete, according to Frieden. However, not all these alternatives are as affordable and as ubiquitous as copper landlines, a problem that could leave many rural residents underserved, he said.

Frieden said rural customers could replace land line telephones with cellular phones, for example, but most cell phone companies charge a fee for each minute of use — metering — while most fees for land lines are unmetered and are paid through a fixed monthly charge. He also doubts that cellular service will be as dependable as landlines.

“Cell phone companies have these colorful maps that show how well they cover areas,” Frieden said. “But there are lots of places — including places in rural Pennsylvania, West Virginia and New York — that do not have cell phone service, or offer limited services not suitable for broadband, Internet access.”

Fiber optic lines are glass wires that can carry voice, television and Internet signals. For instance, fiber optic equipment is often used for Voice Over Internet Protocol — VOIP — a technology that uses broadband Internet to carry such services as voice, texting and fax.

While fiber optic lines are more common now, they are usually not found in rural or remote areas.

“The phone companies are right,” said Frieden. “There are other forms of competition now, but these alternatives are not fair or adequate everywhere.”

As communication technologies merge, telephone companies face stiff competition from cable companies, which are classified as information service providers by the government and face limited regulation. Frieden said that telephone companies, however, are regulated as a utility. As a utility, phone companies — called carriers of last resort — are obligated to provide service to customers. To increase profitability, telephone companies would like to be released from the carrier-of-last-resort designation that binds them to providing high-cost, labor-intensive telephone landline service.

Frieden said that the push to end the phone company’s status as carriers of last resort may be the first step toward complete deregulation.

While telephone company lobbyists suggest that the market forces will ensure that all customers will eventually receive equal service in a deregulated environment, Frieden is skeptical about this promise.

“Everyone wants to say, the marketplace is great,” Frieden said. “But there’s also something called market failure particularly in rural and low-income areas.”

Ref.: Rob Frieden, The mixed blessing of a deregulatory endpoint for the public switched telephone network, presented at the End of the Phone System workshop held at the University of Pennsylvania, under review by the Journal of Information Policy

Reconstruction of Gage's skull and brain tissue (credit: John Darrell Van Horn et al./UCLA)

In 1848, Phineas Gage, the supervisor for the Rutland and Burlington Railroad in Vermont was using a 13-pound, 3-foot-7-inch rod to pack blasting powder into a rock when he triggered an explosion that drove the rod through his left cheek and out of the top of his head.

Miraculously, Gage lived, becoming the most famous case in the history of neuroscience because of the injury’s reported effects on his personality and behavior, which were said to be profound.

Gage went from being an affable 25-year-old to one that was fitful, irreverent and profane. His friends and acquaintances said he was “no longer Gage.”

Over the years, various scientists have studied and argued about the exact location and degree of damage to Gage’s cerebral cortex and the impact it had on his personality. Now, for the first time, researchers at UCLA, using brain-imaging data that was lost to science for a decade, have broadened the examination of Gage to look at the damage to the white matter “pathways” that connect various regions of the brain.

Reporting in the May 16 issue of the journal PLoS ONE, Jack Van Horn, a UCLA assistant professor of neurology, and colleagues note that while approximately 4 percent of the cerebral cortex was intersected by the rod’s passage, more than 10 percent of Gage’s total white matter was damaged. The passage of the tamping iron caused widespread damage to the white matter connections throughout Gage’s brain, which likely was a major contributor to the behavioral changes he experienced.

Because white matter and its myelin sheath — the fatty coating around the nerve fibers that form the basic wiring of the brain — connect the billions of neurons that allow us to reason and remember, the research not only adds to the lore of Phineas Gage but may eventually lead to a better understanding of multiple brain disorders that are caused in part by similar damage to these connections.

“What we found was a significant loss of white matter connecting the left frontal regions and the rest of the brain,” said Van Horn, who is a member of UCLA’s Laboratory of Neuro Imaging (LONI). “We suggest that the disruption of the brain’s ‘network’ considerably compromised it. This may have had an even greater impact on Mr. Gage than the damage to the cortex alone in terms of his purported personality change.”

LONI is part of an ambitious joint effort with Massachusetts General Hospital and the National Institutes of Health to document the trillions of microscopic links between every one of the brain’s 100 billion neurons — the so-called “connectome.” And because mapping the brain’s physical wiring eventually will lead to answers about what causes mental conditions that may be linked to the breakdown of these connections, it was appropriate, as well as historically interesting, to take a new look at the damage to Gage’s brain.

Since Gage’s 189-year-old skull, which is on display in the Warren Anatomical Museum at Harvard Medical School, is now fragile and unlikely to again be subjected to medical imaging, the researchers had to track down the last known imaging data, from 2001, which had been lost due to various circumstances at Brigham and Women’s Hospital, a teaching affiliate of Harvard, for some 10 years.

The authors were able to recover the computed tomographic data files and managed to reconstruct the scans, which revealed the highest-quality resolution available for modeling Gage’s skull. Next, they utilized advanced computational methods to model and determine the exact trajectory of the tamping iron that shot through his skull.

Finally, because the original brain tissue was, of course, long gone, the researchers used modern-day brain images of males that matched Gage’s age and (right) handedness, then used software to position a composite of these 110 images into Gage’s virtual skull, the assumption being that Gage’s anatomy would have been similar.

Van Horn found that nearly 11 percent of Gage’s white matter was damaged, along with 4 percent of the cortex.

“Our work illustrates that while cortical damage was restricted to the left frontal lobe, the passage of the tamping iron resulted in the widespread interruption of white matter connectivity throughout his brain, so it likely was a major contributor to the behavioral changes he experienced,” Van Horn said.

“Connections were lost between the left frontal, left temporal and right frontal cortices and the left limbic structures of the brain, which likely had considerable impact on his executive as well as his emotional functions.”

And while Gage’s personality changed, he eventually was able to travel and find employment as a stagecoach driver for several years in South America. Ultimately, he died in San Francisco, 12 years after the accident.

A modern parallel

“The extensive loss of white matter connectivity, affecting both hemispheres, plus the direct damage by the rod, which was limited to the left cerebral hemisphere, is not unlike modern patients who have suffered a traumatic brain injury,” he said.

“And it is analogous to certain forms of degenerative diseases, such as Alzheimer’s disease or frontal temporal dementia, in which neural pathways in the frontal lobes are degraded, which is known to result in profound behavioral changes.”

Van Horn noted that the quantification of the changes to Gage’s brain’s pathways might well provide important insights for clinical assessment and outcome-monitoring in modern-day brain trauma patients.

The work was performed as part of the Human Connectome Project.

Ref.: John Darrell Van Horn et al., Mapping Connectivity Damage in the Case of Phineas Gage, PLoS ONE, 2012 (open access)

Debrief tool used in the experiment displays a video replay of the operator console (similar to this map display), and a timeline of events suggested by AEMASE for discussion during debrief. The tool also includes visualizations of entity movement over time. (Credit: S. M. Stevens-Adams et al.)

Navy pilots and other flight specialists soon will have a new “smart machine” installed in training simulators that learns from expert instructors to more efficiently train their students.

Sandia National Laboratories’ Automated Expert Modeling & Student Evaluation (AEMASE, pronounced “amaze”) is being provided to the Navy as a component of flight simulators.

Components are now being used to train Navy personnel to fly H-60 helicopters and a complete system will soon be delivered for training on the E-2C Hawkeye aircraft, said Robert G. Abbott, a Sandia computer scientist and AEMASE’s inventor. The work is sponsored by the Office of Naval Research.

AEMASE is a cognitive software application that updates its knowledge of experts’ performance on training simulators in real time to prevent training sessions from becoming obsolete and automatically evaluates student performance, both of which reduce overall training costs, Abbott said.

“AEMASE is able to adapt and is aware of what’s going on,” he said. “That’s what’s driving our cognitive modeling and automated systems that learn over time from the environment and from their interactions with people.”

Previous flight simulators have not done well with ambiguous or new situations that required time-consuming reprogramming, making it difficult for the military to adapt quickly to changing environments and tactics.

AEMASE bypasses lengthy interviews of instructors and reprogramming once the simulator is running. Instead, instructors fly the simulator themselves to capture their expertise, a feature that works particularly well in ambiguous situations where it’s difficult to program a set of explicit rules, Abbott said.

Melissa Walwanis, a senior research psychologist at the Naval Air Warfare Center’s Training System Division in Orlando, Fla., said AEMASE will give Navy trainees specific ways to improve performance through machine learning, automated performance measurement, and recordings of trainees’ voices during the training sessions.

AEMASE addresses a needle-in-a-haystack problem. Just as search engines find certain words across the Internet, AEMASE scans hundreds of training sessions to find specific actions or scenarios and makes comparisons, Abbott said.

The software is designed for context recognition. It searches until it recognizes a situation it has seen before and determines whether the students are making a desirable decision, Abbott said.

The software recognizes there may be multiple right answers that incorporate different ways of responding to the situation, Forsythe added. For example, AEMASE tracks certain flight parameters — say distance, the angle of the aircraft from the ground and velocity — to create vectors that are treated as points within a multidimensional space defined by the parameters.

Different “right” answers are expressed as points in the space, but will tend to gather in one area, while poor performance can be measured by a point’s distance from the “expert” points.

But for instructors, AEMASE’s interface is simple. They can flag actions by pushing a one-click thumbs-up button to record good behavior or a thumbs-down button when students fly too low or too close together in the simulation, Abbott said.

AEMASE places those flagged events on a timeline display, so instructors and students can review errors in recordings of student performance. Then AEMASE uses that information to recognize other instances of the errors, helping the instructors become more efficient by automatically flagging errors for them to review with other students.

These flags are the seeds for the model’s future development as scenarios and preferred actions evolve over time, Forsythe said.

AEMASE also incorporates speech recognition technology to assess how effectively teams communicate.

Sandia is adapting the software to similar training aids for computer security analysts. Potential applications include driver’s education, automating robots, and many other areas, Abbott said.

Prototype of EEG-driven bionic legs (credit: Joy Wilson, University of Houston)

Dr. José Contreras-Vidal of the University of Houston has designed a pair of bionic legs that respond directly to signals from the brain.

The problem with the current brain-computer interface approach — implanting electrodes into a brain, as in the BrainGate2 system, is that it’s a dangerous procedure and can also lead to infections. It also requires a bulky hardware system.

Contreras-Vidal’s approach gets round these difficulties by employing electroencephalography (EEG), which measures those electrical signals from the brain that reach the scalp. The recording electrodes can be carried by a skull cap, and nothing has to penetrate the skin.

Such second-hand signals are not as precise as ones collected directly from the brain itself, and probably could not control the complex movements required of an arm and a hand, but he and colleagues at the University of Maryland were able to do this by analyzing what goes on in the brain when someone moves his limbs.

They used a system of cameras to record the movement patterns of a set of able-bodied volunteers who were walking on a treadmill, and then correlated the result with the electrical signals detected simultaneously at their scalps.

Even a simple task, like wiggling a toe, engages many parts of the brain. These include the frontal cortex (where decisions are made), the motor cortex (which controls muscle activity), the somatosensory cortex (where the sense of touch is located) and the part of the parietal cortex that regulates kinaesthesia (the sense of bodily motion, which is built up from signals from the muscles and the vestibular systems of the ears). By choosing sites carefully, the researchers were able to cover all these areas with as few as 12 electrodes.

The next step is to turn the result into reliable instructions that can operate a set of legs. These are made by Rex Bionics, a firm based in New Zealand. They are a partial exoskeleton that allows a user to stand and walk independently, without crutches, and are normally operated by hand controls. To adapt them to thought control, a group of able-bodied people will first don the cap and perambulate in the legs around a laboratory, to refine the process. Then — with luck, some time this summer — a full-scale trial in collaboration with a group of paralysed volunteers will start.

If the trial works, Dr Contreras-Vidal and his colleagues believe their technique will transform the lives of those with spinal injuries. It might also act as a form of physiotherapy, to help victims of strokes restore the use of their legs.

And it will certainly save a lot of money. A set of bionic legs can cost as much as $150,000. But the lifetime cost of caring for a 25-year-old with severe spinal injury is around $3m.

ZeroN (credit: MIT Media Lab)

In The Avengers, Tony Stark manipulates objects in thin air. MIT Media Lab researchers Jinha Lee and  Rehmi Post have actually created a similar tactile user interface for manipulating real floating objects in 3D space, called the ZeroN.

It’s essentially a small field in which gravity doesn’t overcome an object. Through the efforts of finely tuned electromagnetism, a user can place a metal ball in midair as easily as they’d place something on a shelf.

The ball can be repositioned by hand or by computer, it can be animated on a path, and with the help of software, it can even serve as a virtual camera or light source in a 3-D scene (a sort of 3-D animation suite that you can touch).

Lee has hidden the real magic just above where there’s a 3-D actuator housing an electromagnet. It’s this arm that provides the perfectly tuned magnetic loop (requiring a circuit built by Rehmi Post from MIT’s Center for Bits and Atoms), to keep the ball stable. But to drag that ball around lateral space, the actuator actually just repositions itself, moving in tandem with object, and keeping an eye out on its position with 3-D infrared cameras (as you see in the Kinect).

“ZeroN can remember how it has been moved. Physical motions of people can be collected in this medium to preserve and play them back indefinitely. When the users move and release the ZeroN, it continues to float and starts to move along the same path. This allows a unique, tangible record of a user’s physical presence and motion which will continue to exist even after the death of the person,” Lee explains.

“With this functionality, ZeroN can be adopted in many applications: animation prototyping, physics simulation/education, and 3-D design studios, etc. Many of the control that users had to have with mouse and a screen can be tangible and more intuitive.”

Alginate-based "pearls" containing antiaging ingredients are mixed into an activating cream in three layers, including 20- to 200-nm nanoemulsions to encapsulate lipophilic actives (credit: Capsum)

Growing demand for “enhanced cosmetics” is fostering research on micro-capsules and other technology to package those ingredients in creams, lotions and other products to take advantage of a global market valued at $425 billion in 2011.

To meet that demand, chemical companies are looking for better ways to encapsulate these additives — which can reduce inflammation, repair hair or prevent wrinkles — to stop them from breaking down in the bottle or help deliver them to the skin and hair more effectively.

A surfactant concentrated in the lamellar phase and engineered to form an onionlike vehicle has voids that can encapsulate and deliver active ingredients to skin and hair (credit: Rhodia)

Active ingredient delivery systems are already incorporated into 10 to 20 percent of cosmetics on the market today, a number predicted to grow to 35 or 45 percent in five years.

Cosmetics makers are adopting novel delivery systems for skin using a variety of micelles, vesicles, surfactants, and polymers, but they don’t often reveal those details to the public. Exceptions include:

• Air Products & Chemicals has adapted an insulin sugar delivery system to make better sunscreen.
• Microcapsules help coat the skin with protective ingredients, while another capsule system carries vitamins C and E beneath the skin as a second line of defense.
• Rovi’s Dermoprotectyl, a skin care ingredient, that combines two systems for delivering actives has two systems. One, based on inulin sugar nanoscale vesicles, places sunscreen ingredients on the surface of the skin. A second system, using lipid protective spheres, deposits vitamins E and C just below the surface of the skin for a second line of defense against sun-induced damage.
• A product from Evonik Industries uses water droplets coated in silica to make a “dry water.” When combined with a powder containing fragrances or vitamins and rubbed on skin or in hair, the water is released to form a cream that delivers the ingredients.

Ref.: Marc S. Reisch, Enhancing Cosmetics, Chemical & Engineering News, 2012 (open access)

Artist's view of a dust torus surrounding the accretion disk and central black hole in active galactic nuclei (credit: Sonoma State University, Aurore Simonnet)

By combining the light of three powerful infrared telescopes, an international research team has observed the active accretion phase of a supermassive black hole in the center of a galaxy tens of millions of light years away, yielding an unprecedented amount of data for such observations.

The resolution at which they were able to observe this highly luminescent active galactic nucleus (AGN) has given them direct confirmation of how mass accretes onto black holes in centers of galaxies.

“This three-telescope interferometry is a major milestone toward directly imaging the growth phase of supermassive black holes,” said Sebastian Hoenig, a postdoctoral researcher at the UC Santa Barbara Department of Physics.

Very Large Telescope Interferometer at the ESO/Paranal Observatory in Chile (credit: Sebastian Hoenig)

They found that a ring of hot dust that marks the transition from a more-distant mixture of gas and dust in a toroidal (doughnut-shaped) structure to a gaseous disk closer to the black hole. The dusty part is interesting because it dominates the infrared emission of active galactic nuclei and can be easily observed, said Gerd Weigelt, a director of the Max Planck Institute for Radio Astronomy.

By using the AMBER interferometry instrument to simultaneously combine the light from three 8-meter telescopes at the Very Large Telescope Interferometer (VLTI) at the Paranal Observatory in Chile, the research team was able to achieve the angular resolution needed to observe the hot dust ring. The Paranal Observatory is operated by the European Southern Observatories (ESO). To achieve the needed angular resolution in a single telescope, it would have to be 130 meters in diameter.

The combination of the light from the three telescopes was no small feat, as the tiny differences in the arrival of light in the individual telescopes have to undergo constant correction with an accuracy of a few microns.

Participating institutions:

• Max-Planck-Institute for Radioastronomy
• UCSB Department of Physics
• Department of Physics and Astronomy, University of Firenze
• INAF — Astrophysical Observatory of Arcetri
• Lagrange Laboratory,  University of Nice Sophia-Antipolis, CNRS
• University Joseph Fourier (UJF) — Grenoble
• Institute of Planetology and Astrophysics of Grenoble (IPAG)

Ref.: G. Weigelt et al., VLTI/AMBER observations of the Seyfert nucleus of NGC 3783, Astronomy and Astrophysics, 2012, DOI: 10.1051/0004-6361/201219213 (open access)

Demonstration of ultrafast disintegration of matter by 2 keV LCLS pulses: The team combined techniques commonly used in solid state physics (Bragg reflection) with techniques from plasma physics (spectroscopy of diffusely-scattered light) to characterize ultrafast heating in graphite. (Credit: LLNL)

For the first time, scientists have seen an X-ray-irradiated mineral go to two different states of matter in about 40 femtoseconds (a femtosecond is one quadrillionth of a second).

Using the Linac Coherent Light Source (LCLS) X-ray Free-Electron Laser (XFEL) at SLAC National Accelerator Laboratory at Stanford, Stefan Hau-Riege of Lawrence Livermore National Laboratory and colleagues heated graphite to induce a transition from solid to liquid and to warm-dense plasma.

Ultrafast phase transitions from solid to liquid and plasma states are important in the development of new material-synthesis techniques, in ultrafast imaging, and high-energy density science.

By using different pulse lengths and calculating different spectra, the team was able to extract the time dependence of plasma parameters, such as electron and ion temperatures and ionization states.

“We found that the heating and disintegration of the ion lattice occurs much faster than anticipated,” Hau-Riege said.

The research provides new insights into the behavior of matter irradiated by intense hard X-rays. Though the study ultimately serves as a breakthrough in plasma physics and ultrafast materials science, it also affects other fields such as single molecule biological imaging and X-ray optics.

For single-molecule bioimaging, the team found that in certain cases it may be substantially more difficult than anticipated because energy transfer is surprisingly fast. In X-ray optics, they found that the damage threshold is lower than anticipated.

This is the first XFEL high-energy density science experiment that used inelastic X-ray scattering as a plasma diagnostic.

In addition to SLAC National Accelerator Laboratory, participating institutions include Universitat Duisburg-Essen; Max Planck Advanced Study Group, Center for Free Electron Laser Science; Max Planck Institut fur medizinische Forschung; and Max Planck Institut fur Kernphysik, all of Germany.

Ref.: Forthcoming in May 21 edition of Physical Review Letters.

A double quantum dot. Each electron spin (SL or SR) defines one quantum bit (qubit) (credit: D. Loss and D. P. DiVincenzo)

Harvard scientists have demonstrated quantum entanglement between two spin qubits for the first time, using electrostatic interaction between electrons.

Spin qubits are tiny droplets of free electrons created within quantum dots, small devices fabricated from standard semiconductor materials.

Spin qubits have several advantages as elements in a quantum computer: they operate at room temperature (unlike other devices, which require extremely low temperatures and expensive support systems), they can be fabricated using standard photolithography techniques (for mass production), and the spin is easily controlled, using the electron spin (up-down) to act as the qubit.

However, environmental fluctuations can cause entanglement between the qubits to degrade because the electrostatic interaction is weak, said Amir Yacoby, Harvard University professor of physics and applied physics, who led the research.

His team overcame this problem by allowing the qubits to interact for a precise amount of time, then flipping them, which causes them to return to their initial state. This maintains the delicate relationship between the qubits while overcoming outside disturbances from the external environment.

But it takes time to create that entanglement, and during that time, various elements are trying to interact with the individual qubits, which cause them to lose their information, he said. “It took some creative thinking to design a system that would allow their entanglement to accumulate, but would limit their interaction with the rest of their environment.”

This method of quantum error correction has been used to correct disturbances in other systems — in superconducting qubits, for example — but this is the first time it has been demonstrated in spin qubits.

Ref.: M. D. Shulman et al., “Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits,” Science, 2012 [DOI: 10.1126/science.1217692]

(Credit: Soctech/Flickr)

Greek officials are cobbling together an emergency plan after talks to form a coalition government disintegrated Tuesday. In the meantime, Greeks have withdrawn $900 million from local banks.

With Greece in deep political turmoil (some are even talking apocalyptically of civil war) after voters backed an incoherent constellation of anti-austerity parties, European central bankers and finance ministers have been warning it that its departure from the euro is inevitable if it does not abide by the terms of its bail-out.

Also see:

Groping towards Grexit
The Bank Runs In Greece Will Soon Be Followed By Bank Runs In Other European Nations
Nationalized Spanish Bank Plummets On News Of Bank Run

Georgia Tech researchers adjust optics as part of research into the production of single photons for use in optical quantum information processing and the study of certain physical systems (credit: John Toon)

Researchers at Georgia Tech have used lasers to reliably and individually produce single photons from individual atoms in a cloud of ultra-cooled rubidium gas.

Single photons are an essential element for guaranteed secure communications in quantum cryptography — where an attacker can use extra or stray photons to eavesdrop on a message — and to address individual qubits in quantum memory architectures, where single atoms may serve as the storage unit.

This reliable, high-speed method of creating single photons can also be used to distribute entanglement to remote locations, as used in quantum teleportation, thus making the method a potential enabler for quantum repeaters for long-distance quantum communications, says Georgia Tech prof. Alex Kuzmich, lead investigator for the research.

“We are able to convert single-atom excitations into single photons with very substantial efficiency, for investigating entangled states of atoms, spin waves and photons,” he explained . “This new photon source is about 1,000 times faster than any existing system.”

Creating single photons: (A) A cold dense sample of atomic Rubidium gas is prepared as an optical lattice. Two light fields (Ω1 and Ω2) excite a single atom from the ground state to produce a spin wave. A readout laser pulse (Ω3) converts the spin wave into a single photon. Two detectors, D1 and D2, measure the photon. (B) Relevant quantum energy levels for the Rubidium gas; and electronic, hyperfine, and Zeeman quantum numbers. (Credit: Y. O. Dudin et al/Science)

“The next goal may to develop a quantum gate between light fields to deterministically create complex entangled states of atoms and light, which would add valuable capabilities [such as scalable, complex quantum memories] to the fields of quantum networks and computing,” explained Kuzmich. “With further increases in efficiency and generation rate — and integration with long-lived quantum memories — such a single-photon source may make optical quantum information processing possible.”

“Our results also hold promise for studies of dynamics and disorder in many-body systems with tunable interactions,” Kuzmich explained. “In particular, translational symmetry breaking, phase transitions and non-equilibrium many-body physics could be investigated in the future, using strongly-coupled Rydberg excitations of an atomic gas.”

A primary feature of these systems is that the interaction between the atoms can can be tuned — from very strong, to none at all. This tunable interaction may enable physicists to understand the behavior of complex materials, and to create entirely new, exotic quantum phases of matter that don’t yet exist in nature.

Ref.: Y. O. Dudin, A. Kuzmich, “Strongly Interacting Rydberg Excitations of a Cold Atomic Gas,” Science, April 2012 DOI:10.1126/science.1217901

Google Knowledge Graph

Google has launched the Knowledge Graph, which it says will help you discover new information quickly and easily, according to the Official Google Blog.

Think of it as Google + Wikipedia + Wolfram Alpha + Bing.

Take a query like [taj mahal]. For more than four decades, search has essentially been about matching keywords to queries. To a search engine, the words [taj mahal] have been just that — two words.

So Google has been working on an intelligent model — a “graph” — that understands real-world entities and their relationships to one another: things, not text strings.

The Knowledge Graph enables you to search for things, people or places that Google knows about — landmarks, celebrities, cities, sports teams, buildings, geographical features, movies, celestial objects, works of art and more — and instantly get information that’s relevant to your query.

“This is a critical first step towards building the next generation of search, which taps into the collective intelligence of the web and understands the world a bit more like people do,” the Google blog says.

Google’s Knowledge Graph is rooted in public sources such as Freebase, Wikipedia and the CIA World Factbook, but it’s also augmented at a much larger scale — “because we’re focused on comprehensive breadth and depth,” the blog says. “It currently contains more than 500 million objects, as well as more than 3.5 billion facts about and relationships between these different objects. And it’s tuned based on what people search for, and what we find out on the web.”

The Knowledge Graph enhances Google Search in three main ways to start:

1. Find the right thing

Language can be ambiguous — do you mean Taj Mahal the monument, or Taj Mahal the musician? Now Google understands the difference, and can narrow your search results just to the one you mean — just click on one of the links to see that particular slice of results.

This is one way the Knowledge Graph makes Google Search more intelligent — your results are more relevant because we understand these entities, and the nuances in their meaning, the way you do.

2. Get the best summary

With the Knowledge Graph, Google can better understand your query, so it can summarize relevant content around that topic, including key facts you’re likely to need for that particular thing. For example, if you’re looking for Marie Curie, you’ll see when she was born and died, but you’ll also get details on her education and scientific discoveries.

How do we know which facts are most likely to be needed for each item? For that, we go back to our users and study in aggregate what they’ve been asking Google about each item. For example, people are interested in knowing what books Charles Dickens wrote, whereas they’re less interested in what books Frank Lloyd Wright wrote, and more in what buildings he designed.

The Knowledge Graph also helps us understand the relationships between things. Marie Curie is a person in the Knowledge Graph, and she had two children, one of whom also won a Nobel Prize, as well as a husband, Pierre Curie, who claimed a third Nobel Prize for the family. All of these are linked in our graph. It’s not just a catalog of objects; it also models all these inter-relationships. It’s the intelligence between these different entities that’s the key.

3. Go deeper and broader

The Knowledge Graph can help you make some unexpected discoveries. You might learn a new fact or new connection that prompts a whole new line of inquiry. Do you know where Matt Groening, the creator of the Simpsons, got the idea for Homer, Marge and Lisa’s names? It’s a bit of a surprise.

“We’ve always believed that the perfect search engine should understand exactly what you mean and give you back exactly what you want,” says the blog. “And we can now sometimes help answer your next question before you’ve asked it, because the facts we show are informed by what other people have searched for.

“For example, the information we show for Tom Cruise answers 37 percent of next queries that people ask about him. In fact, some of the most serendipitous discoveries I’ve made using the Knowledge Graph are through the magical ‘People also search for’ feature. One of my favorite books is The White Tiger, the debut novel by Aravind Adiga, which won the prestigious Man Booker Prize. Using the Knowledge Graph, I discovered three other books that had won the same prize and one that won the Pulitzer. I can tell you, this suggestion was spot on!

Google has begun to gradually roll out the Knowledge Graph to U.S. English users. It’s also going to be available on smartphones and tablets.

Using a new microscopy method called multifocal SIM (MSIM), nanoscale cell structures such as microtubules (shown here) can be observed in living fish embryos (credit: NIH, KIT)

A new hybrid method to visualize cell structures in living fish larvae has been developed by researchers of Karlsruhe Institute of Technology (KIT), the Max Planck Institute for Polymer Research, Mainz, and the U.S. National Institutes of Health (NIH).

“The zebrafish is perfectly suited for genetic studies of cells, as its larvae are completely transparent,” explains Marina Mione of KIT.

Microtubules, a key component of the the cell’s cytoskeleton, have a length of about 100 µm and a diameter of about 20 nm, corresponding to a hundred thousandth of a human hair.

The new hybrid microscopy method is called multifocal SIM (MSIM), which combines the resolution-doubling characteristics of structured illumination microscopy (SIM) with the physical optical sectioning of confocal microscopy. The method uses commercially available parts and open-source software, allowing for easy integration with wide-field microscopes.

The object is not illuminated completely, but only at a certain spot with special light. Scattered light is minimized and the illuminated detail is represented sharply. A series of images taken at variable illumination is then processed by a computer.

Smart illumination even allows for adjusting the depth of field to image various depth levels, and to combine them into a 3D image on the computer.

The researchers observed the early stage of the fish’s lateral line, which develops about 45 µm below the skin of the fish. Via this organ, the fish perceives movement stimuli in water. Such images of living organisms also provide valuable findings regarding the development of vertebrates on the cellular level.

The tropical zebrafish living in freshwater has several advantages as a genetic model organism. It is sufficiently small for easy cultivation and large enough to easily distinguish individual organs. It has a short generation cycle and produces many offsprings. And as a vertebrate, it has a number of microbiological properties in common with human beings.

Ref.: Andrew G York et al., Resolution doubling in live, multicellular organisms via multifocal structured illumination microscopy, Nature Methods, 2012, DOI: 10.1038/nmeth.2025

(Credit: Brown University)

On April 12, 2011, nearly 15 years after she became paralyzed and unable to speak, a woman controlled a robotic arm by thinking about moving her arm and hand to lift a bottle of coffee to her mouth and take a drink, using the BrainGate neural interface system.

That achievement is one of the advances in brain-computer interfaces, restorative neurotechnology, and assistive robot technology by the BrainGate2 collaboration of researchers at the Department of Veterans Affairs, Brown University, Massachusetts General Hospital, Harvard Medical School, and the German Aerospace Center (DLR).

The BrainGate2 Neural Interface System: an implanted microelectrode array detects brain signals, which are converted by a computer into machine instructions, allowing control of robotic devices by thought (credit: Brown University)

A 58-year-old woman and a 66-year-old man participated in the study. They had each been paralyzed by a brainstem stroke years earlier, which left them with no functional control of their limbs.

In the research, the participants used neural activity to directly control two different robotic arms, one developed by the DLR Institute of Robotics and Mechatronics and the other by DEKA Research and Development Corp., to perform reaching and grasping tasks across a broad three-dimensional space.

The BrainGate2 pilot clinical trial employs the investigational BrainGate system initially developed at Brown University, in which a baby aspirin-sized device with a grid of 96 tiny electrodes is implanted in the motor cortex — a part of the brain that is involved in voluntary movement.

The electrodes are close enough to individual neurons to record the neural activity associated with intended movement. An external computer translates the pattern of impulses across a population of neurons into commands to operate assistive devices, such as the DLR and DEKA robot arms used in the study.

BrainGate participants have previously demonstrated neurally based two-dimensional point-and-click control of a cursor on a computer screen and rudimentary control of simple robotic devices.

The study represents the first demonstration and the first peer-reviewed report of people with tetraplegia using brain signals to control a robotic arm in three-dimensional space to complete a task usually performed by their arm.

“Our goal in this research is to develop technology that will restore independence and mobility for people with paralysis or limb loss,” said lead author Dr. Leigh Hochberg, a neuroengineer and critical care neurologist who holds appointments at the Department of Veterans Affairs, Brown University, Massachusetts General Hospital, and Harvard.

Hochberg adds that even after nearly 15 years, a part of the brain essentially “disconnected” from its original target by a brainstem stroke was still able to direct the complex, multidimensional movement of an external arm — in this case, a robotic limb. The researchers also noted that one patient was able to perform the tasks more than five years after the investigational BrainGate electrode array was implanted. This sets a new benchmark for how long implanted brain-computer interface electrodes have remained viable and provided useful command signals.

John Donoghue, the VA and Brown neuroscientist who pioneered BrainGate more than a decade ago and who is co-senior author of the study, said the paper shows how far the field of brain-computer interfaces has come since the first demonstrations of computer control with BrainGate.

“This paper reports an important advance by rigorously demonstrating in more than one participant that precise three-dimensional neural control of robot arms is not only possible, but also repeatable,” said Donoghue, who directs the Brown Institute for Brain Science.

“We’ve moved significantly closer to returning everyday functions, like serving yourself a sip of coffee, usually performed effortlessly by the arm and hand, for people who are unable to move their own limbs. We are also encouraged to see useful control more than five years after implant of the BrainGate array in one of our participants. This work is a critical step toward realizing the long-term goal of creating a neurotechnology that will restore movement, control, and independence to people with paralysis or limb loss.”

In the research, the robots acted as a substitute for each participant’s paralyzed arm. The robotic arms responded to the participants’ intent to move as they imagined reaching for each foam target. The robot hand grasped the target when the participants imagined a hand squeeze. Because the diameter of the targets was more than half the width of the robot hand openings, the task required the participants to exert precise control.

In 158 trials over four days, subject S3 was able to touch the target within an allotted time in 48.8 percent of the cases using the DLR robotic arm and hand and 69.2 percent of the cases with the DEKA arm and hand, which has the wider grasp. In 45 trials using the DEKA arm, T2 touched the target 95.6 percent of the time. Of the successful touches, S3 grasped the target 43.6 percent of the time with the DLR arm and 66.7 percent of the time with the DEKA arm. T2’s grasp succeeded 62.2 percent of the time.

T2 performed the session in this study on his fourth day of interacting with the arm; the prior three sessions were focused on system development. Using his eyes to indicate each letter, he later described his control of the arm: “I just imagined moving my own arm and the [DEKA] arm moved where I wanted it to go.”

The study used two advanced robotic arms: the DLR Light-Weight Robot III with DLR five-fingered hand and the DEKA Arm System. The DLR LWR-III, which is designed to assist in recreating actions like the human arm and hand and to interact with human users, could be valuable as an assistive robotic device for people with various disabilities.

Patrick van der Smagt, head of bionics and assistive robotics at DLR, director of biomimetic robotics and machine learning labs at DLR and the Technische Universität München, and a co-senior author on the paper said: “This is what we were hoping for with this arm. We wanted to create an arm that could be used intuitively by varying forms of control. The arm is already in use by numerous research labs around the world who use its unique interaction and safety capabilities. This is a compelling demonstration of the potential utility of the arm by a person with paralysis.”

DEKA Research and Development developed the DEKA Arm System for amputees, through funding from the United States Defense Advanced Research Projects Agency (DARPA). Dean Kamen, founder of DEKA said, “One of our dreams for the Luke Arm [as the DEKA Arm System is known informally] since its inception has been to provide a limb that could be operated not only by external sensors, but also by more directly thought-driven control.

“We’re pleased about these results and for the continued research being done by the group at the VA, Brown and MGH.” The research is aimed at learning how the DEKA arm might be controlled directly from the brain, potentially allowing amputees to more naturally control this prosthetic limb.

Over the last two years, VA has been conducting an optimization study of the DEKA prosthetic arm at several sites, with the cooperation of veterans and active duty service members who have lost an arm. Feedback from the study is helping DEKA engineers to refine the artificial arm’s design and function. “Brain-computer interfaces, such as BrainGate, have the potential to provide an unprecedented level of functional control over prosthetic arms of the future,” said Joel Kupersmith, M.D., VA chief research and development officer. “This innovation is an example of federal collaboration at its finest.”

Story Landis, director of the National Institute of Neurological Disorders and Stroke, which funded the work in part, noted: “This technology was made possible by decades of investment and research into how the brain controls movement. It’s been thrilling to see the technology evolve from studies of basic neurophysiology and move into clinical trials, where it is showing significant promise for people with brain injuries and disorders.”

Ref.: Leigh R. Hochberg et al., Reach and grasp by people with tetraplegia using a neurally controlled robotic arm, Nature, 2012, DOI: 10.1038/nature11076

(Additional videos available on the Nature website)

(Credit: Iván J. Cajigas et al./Neuron)

Max Planck Institute (MPI) for Brain Research researchers have used new-generation sequencing to directly identify a very large number (more than 2500) of mRNA molecules present in axons and dendrites. The finding my help explain how proteins establish long-term memories.

During learning, information is stored at the synapses, the junctions connecting nerve cells. Synapses also require new proteins to show changes in their strength (synaptic plasticity). Historically, scientists have focused on the neuron cell body as the place where the required proteins are synthesized.

However, in recent years there has been increasing focus on the dendrites and axons (the compartments that meet to form synapses) as a potential site for protein synthesis. Protein synthesis machines have been observed there, as well as a limited number of their templates, the messenger RNA (mRNA) molecules.

However., the limited number of mRNAs observed in dendrites and axons placed constraints on the constellation of proteins that could be synthesized to help synapses work and change. Using microarray approaches and in situ hybridization techniques, many different research groups had each identified a hundred or so mRNAs that might reside in the dendrites.

By comparing these studies, the Schuman team discovered something surprising: not a single mRNA type was found in all three studies. This observation made the scientists at the MPI for Brain Research wonder whether the already discovered mRNAs are just the tip of the iceberg and whether there were many more mRNA molecules waiting to be discovered.

To find out, the researchers dissected the neuropil layer of the rat hippocampus. This layer comprises a high concentration of axons and dendrites, but lacks the cell bodies of pyramidal neurons (the principal cell type in the hippocampus and other brain areas). By using sensitive high-resolution sequencing techniques, mRNAs could be detected which, due to their lower concentrations, were not discovered before.

The researchers found an impressive number of 2550 unique mRNAs present at the dendrites and/or axons. To determine the relative abundance in the neuronal cells, the scientists at Erin Schuman’s lab used the Nanostring nCounter, a new technique allowing for high-resolution visualization and quantification of single mRNA molecules. They found that the concentration of mRNAs in the neuronal cells varies by three orders of magnitude.

Additionally, the researchers were able to classify many of the mRNAs and determine their function in synaptic plasticity. These include signalling molecules, scaffolds and the receptors for neurotransmitter molecules. In addition, many mRNAs coding for protein implicated in diseases like autism were discovered in the dendrites and axons. Finally, by using advanced imaging techniques, the researchers could directly visualize some of the mRNAs in the neuronal dendrites, hundreds of microns (millionths of meter) from the cell body.

These results reveal a previously unappreciated enormous potential for the local protein synthesis machinery to supply, maintain and modify the dendritic and synaptic protein population. It seems that neurons use a local control mechanism much in the same way that modern societies have learned that the most efficient means to distribute goods to the population is to use local distribution centers.

Ref.: Iván J. Cajigas et al.,  The Local Transcriptome in the Synaptic Neuropil Revealed by Deep Sequencing and High- Resolution Imaging, Neuron, 2012, DOI: 10.1016/j.neuron.2012.02.036

Top candidate genes for schizophrenia. CFG, convergent functional genomics; GWAS, genome-wide association study; ISC, International Schizophrenia Consortium. (Credit: M Ayalew et al./Molecular Psychiatry)

An Indiana University-led research team and collaborators have identified and prioritized a comprehensive group of genes most associated with schizophrenia and that can generate a score indicating whether an individual is at higher or lower risk of developing the disease.

They used a convergent functional genomics approach that incorporates a variety of experimental techniques.

The scientists also were able to apply a panel of their top genes to data from other studies of schizophrenia and successfully identify which patients had been diagnosed with schizophrenia and which had not.

Evaluating the biological pathways in which the genes are active, the researchers also proposed a model of schizophrenia as a disease emerging from a mix of genetic variations affecting brain development and neuronal connections along with environmental factors, particularly stress.

“At its core, schizophrenia is a disease of decreased cellular connectivity in the brain, precipitated by environmental stress during brain development, among those with genetic vulnerability,” said principal investigator Alexander B. Niculescu III, M.D., Ph.D., associate professor of psychiatry and medical neuroscience at the IU School of Medicine and director of the Laboratory of Neurophenomics at the Institute of Psychiatric Research at the IU School of Medicine.

“For first time we have a comprehensive list of the genes that have the best evidence for involvement in schizophrenia,” said Niculescu, who is also staff psychiatrist and investigator at the Richard L. Roudebush Veterans Affairs Medical Center.

Schizophrenia is a relatively widespread psychiatric disease, affecting about 1 percent of the population, often with devastating impact. People with schizophrenia can have difficulty thinking logically and telling the difference between real and unreal experiences, and may engage in bizarre behavior.

When the test estimating the risk for schizophrenia is refined, it could provide guidance to caregivers and health care professionals about young people in families with a history of the disease, prompting early intervention and treatment when behavioral symptoms of schizophrenia occurred among those at higher risk, Dr. Niculescu said.

He stressed that a score indicating a higher risk of schizophrenia “doesn’t determine your destiny. It just means that your neuronal connectivity is different, which could make you more creative, or more prone to illness.”

“It’s all on a continuum; these genetic variants are present throughout the population. If you have too many of them, in the wrong combination, in an environment where you are exposed to stress, alcohol and drugs, and so on, that can lead to the development of the clinical illness,” he said.

The prototype test was able to predict whether a person was at a higher or lower risk of schizophrenia in about two-thirds of cases.

Convergent functional genomics

To identify and prioritize the genes reported Tuesday, the researchers combined data from several different types of studies. These included genome-wide association studies, gene expression data derived from human tissue samples, genetic linkage studies, genetic evidence from animal models, and other work. This approach, called convergent functional genomics, has been pioneered by Niculescu and colleagues, and relies on multiple independent lines of evidence to implicate genes in clinical disorders.

The authors noted that the results were stronger when analyses were performed using gene-level data, rather than analyses based on individual mutations — called single nucleotide polymorphisms, or SNPs — in those genes. Multiple different SNPs can spark a particular gene’s role in the development of schizophrenia, so evidence for the genes, and the biological mechanisms in which they play a role, was much stronger from study to study than was the evidence for individual SNPs.

“Finally now, by better understanding the genetic and biological basis of the illness, we can develop better tests for it, as well as better treatments. The future of medicine is not just treatment but prevention, so we hope this work will move things in the right direction.”

Ref.: M Ayalew et al., Convergent functional genomics of schizophrenia: from comprehensive understanding to genetic risk prediction, Molecular Psychiatry, 2012, DOI: 10.1038/mp.2012.37 (open access)

Armageddon film (credit: Touchstone Pictures)

NASA is training a team of astronauts to land on an asteroid to explore its surface, search for minerals, and even learn the skills they may need to destroy it should one pose a threat to the Earth.

Direct GFP fluorescence in shaved back skin of mice treated with the indicated vectors (credit: Bruno Bernardes de Jesus et al./EMBO Molecular Medicine)

Mouse lifespan was extended up to 24 percent with a single gene treatment in research at the Spanish National Cancer Research Centre (CNIO), using gene therapy, a strategy never before employed to combat aging.

Mice treated at the age of one lived longer by 24% on average, and those treated at the age of two, by 13%. The therapy, furthermore, produced an appreciable improvement in the animals’ health, delaying the onset of age-related diseases – like osteoporosis and insulin resistance – and achieving improved readings on ageing indicators like neuromuscular coordination.

The gene therapy utilised consisted of treating the animals with a DNA-modified virus, the viral genes having been replaced by those of the telomerase enzyme, with a key role in aging. Telomerase repairs the extremes of chromosomes, known as telomeres, and in doing so slows the cell’s and therefore the body’s biological clock. When the animal is infected, the virus acts as a vehicle depositing the telomerase gene in the cells.

This study “shows that it is possible to develop a telomerase-based anti-aging gene therapy without increasing the incidence of cancer,” the authors affirm. “Aged organisms accumulate damage in their DNA due to telomere shortening, [this study] finds that a gene therapy based on telomerase production can repair or delay this kind of damage.”

‘Resetting’ the biological clock

Telomeres are the caps that protect the end of chromosomes, but they cannot do so indefinitely: each time the cell divides the telomeres get shorter, until they are so short that they lose all functionality. The cell, as a result, stops dividing and ages or dies. Telomerase gets round this by preventing telomeres from shortening or even rebuilding them. What it does, in essence, is stop or reset the cell’s biological clock.

But in most cells the telomerase gene is only active before birth; the cells of an adult organism, with few exceptions, have no telomerase. The exceptions in question are adult stem cells and cancer cells, which divide limitlessly and are therefore immortal – in fact several studies have shown that telomerase expression is the key to the immortality of tumor cells.

It is precisely this risk of promoting tumor development that has set back the investigation of telomerase-based anti-ageing therapies.

In 2007, CNIO scientists proved that it was feasible to prolong the lives of transgenic mice whose genome had been permanently altered at the embryonic stage, by causing their cells to express telomerase and, also, extra copies of cancer-resistant genes. These animals live 40% longer than is normal and do not develop cancer.

The mice subjected to the gene therapy now under test are likewise free of cancer. Researchers believe this is because the therapy begins when the animals are adult so do not have time to accumulate sufficient number of aberrant divisions for tumours to appear.

Also important is the kind of virus employed to carry the telomerase gene to the cells. The authors selected demonstrably safe viruses that have been successfully used in gene therapy treatment of haemophilia and eye disease. Specifically, they are non-replicating viruses derived from others that are non-pathogenic in humans.

Although this therapy may not find application as an anti-aging treatment in humans, in the short term at least, it could open up a new treatment option for ailments linked with the presence in tissue of abnormally short telomeres, as in some cases of human pulmonary fibrosis.

The vector the scientists use expresses the target gene (telomerase) over a long period, so they were able to apply a single treatment. This might be the only practical solution for an anti-ageing therapy, since other strategies would require the drug to be administered over the patient’s lifetime, multiplying the risk of adverse effects.

Bruno Bernardes de Jesus et al., Telomerase gene therapy in adult and old mice delays ageing and increases longevity without increasing cancer, EMBO Molecular Medicine, 2012 DOI: 10.1002/emmm.201200245

Flexure-FET biosensor (credit: Purdue University)

An ultrasensitive biosensor that could allow for early detection of cancer and for personalized medicine tailored to the specific biochemistry of individual patients has been developed by Purdue University researchers.

The Flexure-FET biosensor combines a mechanical sensor, which identifies a biomolecule based on its mass or size, with an electrical sensor that identifies molecules based on their electrical charge.

The new sensor detects both charged and uncharged biomolecules, allowing a broader range of applications than either type of sensor alone.

The sensor makes it possible to detect small quantities of DNA fragments and proteins deformed by cancer long before the disease is visible through imaging or other methods, said Muhammad A. Alam, a Purdue University professor of electrical and computer engineering.

The sensor’s mechanical part is a vibrating cantilever, a sliver of silicon that resembles a tiny diving board. Located under the cantilever is a transistor, which is the sensor’s electrical part.

In other mechanical biosensors, a laser measures the vibrating frequency or deflection of the cantilever, which changes depending on what type of biomolecule lands on the cantilever. Instead of using a laser, the new sensor uses the transistor to measure the vibration or deflection.

The sensor maximizes sensitivity by biasing both the cantilever and transistor. The cantilever is biased using an electric field to pull it downward as though with an invisible string and the transistor is biased by applying a voltage.

“You can make the device sensitive to almost any molecule as long as you configure the sensor properly,” Alam said.

A key innovation is the elimination of a component called a “reference electrode,” which is required for conventional electrical biosensors but cannot be miniaturized, limiting practical applications. This makes it feasible for low-cost, point-of-care applications in doctors’ offices, Alam said.

Ref.: Ankit Jain, P. R. Nair, M. A. Alam, The Flexure-FET Biosensor: How to Break the Fundamental Sensitivity Limits of Nanobiosensors using Nonlinear Electromechanical Coupling, Proceedings of the National Academy of Sciences, 2012, in press

Increased expression of α2δ and β subunits leads to increased P/Q Ca2+ channel accumulation at synapses: (4) Synapse with neurotransmitter released; (6) Calcium channel (credit: Creative Commons)

Weill Cornell Medical College scientists have discovered that single protein alpha 2 delta controls the volume of neurotransmitters and other chemicals that flow between the synapses of brain neurons.

The study shows how brain cells talk to each other through these signals, relaying thoughts, feelings and action, and this powerful molecule plays a crucial role in regulating effective communication.

In the study, the investigators also suggest how the widely used pain drug Lyrica might work. The alpha 2 delta protein is the target of this drug and the new work suggests an approach to how other drugs could be developed that effectively turn particular neurotransmitter signals on and off to treat neurological disorders.

“We are amazed that any single protein has such power,” says the study’s lead investigator Dr. Timothy A. Ryan, professor of Biochemistry and associate professor of Biochemistry in Anesthesiology at Weill Cornell Medical College. “It is indeed rare to identify a biological molecule’s function that is so potent, that seems to be controlling the effectiveness of neurotransmission.”

The researchers found that alpha 2 delta determines how many calcium channels will be present at the synaptic junction between neurons. The transmission of chemical signals is triggered at the synapse by the entry of calcium into these channels, so the volume and speed of neurotransmission depends on the availability of these channels.

Researchers discovered that taking away alpha 2 delta from brain cells prevented calcium channels from getting to the synapse. “But if you add more alpha 2 delta, you can triple the number of channels at synapses,” Dr. Ryan says. “This change in abundance was tightly linked to how well synapses carry out their function, which is to release neurotransmitters.”

Before this study, it was known that Lyrica, which is used for neuropathic pain, seizures and fibromyalgia, binds to alpha 2 delta, but little was understood about how this protein works to control synapses.

Lifting up the Hood

Dr. Ryan is building what he calls a “shop manual” of neurological function, much of which centers on synaptic neurotransmission. In 2007 and 2008, he discovered crucial clues to how neurons repackage the chemicals used to signal across synapses. In 2011, Dr. Ryan discovered that distinct neurons differently tune the speed by which they package these chemicals. And in a recent study published April 29 in Nature Neuroscience, he described, for the first time, the molecular mechanisms at the synapse that control the release of dopamine, a crucial neurotransmitter.

“We are looking under the hood of these machines for the first time,” he says. “Many neurological diseases are considered to arise from pathologies of synaptic function. The synapse is so complex; at least a few thousand genes control how they work. Repairing them through treatment requires that we understand how they work.”

Dr. Ryan and his team often use two tools to conduct these studies — they pin fluorescent tags on to molecules involved in synaptic function, and use ultra-sensitive microscopy technology to watch these molecules up close and in real-time.

The researchers used the same toolkit to examine the function of calcium channels, which triggers neurotransmission. “At all synapses, the secretion of a neurotransmitter is driven by the arrival of an electric impulse, initiated by another neuron,” Dr. Ryan says. When this impulse arrives at the nerve terminal it triggers the opening of calcium channels. The calcium that rushes in is the key trigger that drives a synapse to secrete its neurotransmitter.

“We have known for the past half century that calcium is a key controller of neurotransmission,” he says. “Any small change in calcium influx has a big impact on neurotransmission.”

Protein Label

But the number of calcium channels at the synapse is not static. Neurons constantly replace worn out channels, and to do this, they build the channels in the neuron’s cell body and then package them up and ship them to the nerve terminal. In some cases, that is a very long journey — as much as a few feet, such as the distance between the brain and the base of the spinal cord or the length of a leg.

In the study, researchers tagged fluorescent proteins onto a gene that encodes protein that makes a calcium channel and delivered it to neurons. They then watched the progress of the newly formed channels as they made their way, from day four to day seven, from the bodies of neurons to the synapse.

They also manipulated the levels of alpha 2 delta, a suspected calcium channel partner, and discovered that when the protein was increased, more calcium channels were moved to the synapse. Less alpha 2 delta reduced the flow. “We discovered that alpha 2 delta made the decision of how many calcium channels should be shipped the length of the neuron to the synapse,” Dr. Ryan says. “It’s like the channels couldn’t be transported without an alpha 2 delta shipping label.”

The research team found however that alpha 2 delta must work in at least two steps. When they impaired a piece of alpha 2 delta that resembles proteins that are involved in how cells bind to each other, they found that this broken alpha 2 delta could still help get calcium channels shipped down to synapses. But once there, they no longer helped drive neurotransmitter release. “This means that not only does alpha 2 delta help to get calcium channels shipped out, but it also implies that something at the synapse has to sign-off on receiving the calcium channels, putting them in the right place for them to do their job,” Dr. Ryan says.

The researchers suggest that Lyrica might work by interfering with this final step since the piece of alpha 2 delta they “broke” that prevents the signing-off resembles parts of proteins that allows them to stick to each other in a kind of handshake.

These findings suggest that future therapies designed to manipulate neurotransmission could try to target this handshaking process, Dr. Ryan says. To do this will require that researchers identify the missing partner in the handshake.

“We hope these exciting findings are providing a new direction in how to make better drugs to control communication between brain cells,” Dr. Ryan says.

Ref.: Michael B. Hoppa, Beatrice Lana, Wojciech Margas, Annette C. Dolphin, Timothy A. Ryan, α2δ expression sets presynaptic calcium channel abundance and release probability, Nature, 2012, DOI: 10.1038/nature11033

Credit: A. Deiters/ACS Chemical Biology)

North Carolina State University researchers are using light-activated molecules to turn gene expression on and off. Their method enables greater precision when studying gene function, and could lead to targeted therapies for diseases like cancer.

NC State chemist Dr. Alex Deiters decided to use Triplex-forming oligonucleotides (TFOs), which are molecules that can prevent gene transcription by binding to double-stranded DNA. To more precisely control TFOs, he attached a light-activated “cage” to a TFO. After exposing TFO to ultraviolet (UV) light and removing the cage, the TFO is free to bind with DNA, inhibiting transcription of the gene of interest.

“In the absence of light, transcription activity is 100 percent,” says Deiters. “When we turn on the light, we can take it down to about 25 percent, which is a significant reduction in gene expression.”

Additionally, Deiters fine-tuned the process by attaching a caged inhibitor strand to the TFO. In the absence of UV light, the TFO behaves normally, binding to DNA and preventing gene expression. However, when exposed to UV light, the caged inhibitor activates and stops the TFO from binding with DNA, turning gene transcription on.

“We’ve created a tool that allows for the light-activation of genetic transcription,” Deiters says. “By giving researchers greater temporal and spatial control over gene expression, we’ve expanded their ability to study the behavior of particular genes in whichever environment they choose.”

Ref.: Alexander Deiters et al., Regulation of Transcription through Light-Activation and Light-Deactivation of Triplex-Forming Oligonucleotides in Mammalian Cells, ACS Chemical Biology, 2012, DOI: 10.1021/cb300161r

23andme finished sample bag (credit: David Orban/Flickr)

Patients see potential benefits from direct-to-consumer genetic testing, but are also concerned about how the test results will be used, and are generally unwilling to pay more than $10 or $20 for them, according to focus groups conducted by researchers at Loyola University Chicago Stritch School of Medicine.

More than a dozen companies, including 23andMe, deCODE Genetics and Navigenics, now test consumers’ genomes for single-gene disorders such as cystic fibrosis; for risks of developing complex disorders involving multiple genes, such as cancer, heart disease and diabetes; for sensitivities to drugs such as Coumadin; and for traits such as hair color, eye color and baldness.

Costs range from about $100 to $1,500. Consumers can order these tests directly and receive results without the involvement of a qualified health-care professional, such as a geneticist or genetic counselor.

Findings:

• Many participants were willing to pay in the $10 to $20 range (the equivalent of a co-pay). A few were willing to pay $100 to $400. Direct-to-consumer genetic tests are not covered by insurance companies. “This situation could exacerbate inequalities in the health-care system, with those having greater financial resources being able to access this elective health-related information while those with fewer resources are unable to pay for it,” researchers wrote.
• Participants generally expressed willingness to test their children, including adopted and foster children. They said testing for disease risks would provide helpful information for the future. But these views are contrary to professional and ethical guidelines, which recommend testing children only if there is an effective intervention for the disease that’s being tested. Otherwise, the children should wait until adulthood and decide for themselves. “Children could be tested without understanding its implications, and parents might take actions that are inappropriate and potentially harmful, based on results without consulting a qualified health professional,” researchers wrote.
• Main reasons to get direct-to-consumer genetic tests: to gain information, seek prevention, seek interventions or help others.
• Main concerns about genetic testing: Are the tests accurate? Who will interpret them? Should results be shared with consumers’ physicians and entered in medical records? And do the tests raise ethical issues such as risks to privacy and confidentiality?

Ref.: Wasson K, Hogan, NS, Sanders TN, Helzlsouer KJ, Primary care patients’ attitudes and decision-making process regarding direct-to-consumer personalized genome testing, American Journal of Bioethics Primary Research, 2012, DOI: 10.1080/21507716.2011.650344

Baidu phone (credit: Baidu)

Baidu, the Chinese answer to Google, has announced details of its soon-to-launch new smartphone and the cloud-centric operating system (OS) that will power it.

The Foxconn-built Changhong H5018 will be the first device powered by Baidu’s “Cloud Smart Terminal” platform, marking ”the arrival of a new era” of sub $150 (1,000 RMB) devices in China.

Every H5018 phone owner will be given a generous 100 GB of storage on Baidu’s Netdrive, a beta service known locally as Wangpan. The Google Drive-like service will store multimedia content in the cloud while linking back to the desktop service, while standard services like Baidu Music, Baidu Map and other applications will come with the phone.

Baidu is also preparing its own dedicated app store — the Baidu Cloud Store — which it says will provide access to “a huge range” of apps to cater for the needs of smartphone owners.

Technode has spotted the arrival of Baidu Xiangce (Baidu Album), a photo-upload service that will sync to Baidu Cloud-powered devices and also be offered standalone.

HyQ robot outdoor test (credit: Italian Institute of Technology)

Researchers from the Italian Institute of Technology took their quadruped robot HyQ for a test run outside the lab for the first time to test new tricks HyQ has learned, including the ability to trot over obstacles without falling, IEET Spectrum Automaton reports. 

The robot is still a strange headless creature, and though a sensor head is in the works, this quadruped might get even weirder with a new hardware addition: arms.

The goal: an autonomous, versatile machine capable of running, jumping, and negotiating rough terrain that could find applications in search-and-rescue operations and exploratory missions.

New Apple maps image based on C3 3D technology (credit: Apple)

It was widely reported yesterday that Apple will likely announce at its WWDC in June that the new version of the built-in maps app in iOS6 will not be fed by Google maps. Instead, Apple has developed its own, in-house 3-D mapping database, based on the acquisition of three mapping software companies between 2009 and 2011, Placebase, C3 Technologies, and Poly9.

The stunning 3D image above is from C3, which, according to the company, uses “previously classified image processing technology… automated software and advanced algorithms… to rapidly assemble extremely precise 3D models, and seamlessly integrate them with traditional 2D maps, satellite images, street level photography and user generated images.” The video below shows a flyover of Oslo using C3′s technology.

Powering a display with electricity generated from viruses (credit: Berkeley Lab)

Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to generate power using harmless viruses that convert mechanical energy into electricity.

The generator produces enough current to operate a small liquid-crystal display. It works by tapping a finger on a postage stamp-sized electrode coated with specially engineered viruses. The viruses convert the force of the tap into an electric charge.

Their generator is the first to produce electricity by harnessing the piezoelectric properties of a biological material. Piezoelectricity is the accumulation of a charge in a solid in response to mechanical stress.

The milestone could lead to tiny devices that harvest electrical energy from the vibrations of everyday tasks such aswalking or shutting a door.

The M13 bacteriophage has a length of 880 nanometers and a diameter of 6.6 nanometers. It’s coated with approximately 2700 charged proteins that enable scientists to use the virus as a piezoelectric nanofiber. (Credit: Berkeley Lab)

It also points to a simpler way to make microelectronic devices. Using self-assembly, the viruses arrange themselves into an orderly film that enables the generator to work.

“More research is needed, but our work is a promising first step toward the development of personal power generators, actuators for use in nano-devices, and other devices based on viral electronics,” says Seung-Wuk Lee, a faculty scientist in Berkeley Lab’s Physical Biosciences Division and a UC Berkeley associate professor of bioengineering.

The materials used to make piezoelectric devices are toxic and very difficult to work with, which limits the widespread use of the technology.

Lee and colleagues used the M13 bacteriophage, which only attacks bacteria and is benign to people, would work. Being a virus, it replicates itself by the millions within hours, so there’s always a steady supply and it’s easy to genetically engineer.

And large numbers of the rod-shaped viruses naturally orient themselves into well-ordered films, much the way that chopsticks align themselves in a box.

To increase the virus’s piezoelectric strength, they used genetic engineering to add four negatively charged amino acid residues to one end of the helical proteins that coat the virus.

The top atomic force microscopy image maps the film's structure-dependent piezoelectric properties, with higher voltages a lighter color. The bottom topographic image shows how the viruses align themselves side-by-side in a film. (Credit: Berkeley Lab)

These residues increase the charge difference between the proteins’ positive and negative ends, which boosts the voltage of the virus.

The scientists further enhanced the system by stacking films composed of single layers of the virus on top of each other. They found that a stack about 20 layers thick exhibited the strongest piezoelectric effect.

When pressure is applied to the generator, it produces up to six nanoamperes of current and 400 millivolts of potential. That’s enough current to flash the number “1” on the display, and about a quarter the voltage of an AAA battery.

“We’re now working on ways to improve on this proof-of-principle demonstration,” says Lee. “Because the tools of biotechnology enable large-scale production of genetically modified viruses, piezoelectric materials based on viruses could offer a simple route to novel microelectronics in the future.”

Ref.: Byung Yang Lee et al., Virus-based piezoelectric energy generation, Nature Nanotechnology, 2012, DOI: 10.1038/nnano.2012.69 (open access)

See also: New low-cost wearable energy source from piezoelectric nanocomposite

The first part of the video shows how Berkeley Lab scientists harness the piezoelectric properties of a virus to convert the force of a finger tap into electricity. The second part shows the “viral-electric” generators in action, first by pressing only one of the generators, then by pressing two at the same time, which produces more current.

The first FDA-approved glucose sensor that plugs into an iPhone (credit: iBGStar)

Fitness trends and health-care problems are creating demand for tiny computers we won’t even notice we’re carrying.

What if your doctor had already received the information from a tiny device built into your cell phone, wallet, or undershirt? Sonny Vu, a cofounder of the medical-device company AgaMatrix, believes a device like this could fundamentally change health care.

He created the first FDA-approved glucose sensor that plugs into an iPhone; it hit Apple stores this month under the brand name iBGStar.

Now he’s heading a new company called Misfit Wearables, which is developing health monitoring devices that he says will fit unobtrusively into the clothing and objects we use every day, and make it possible automatically provide medical services such as remote monitoring of patients or automatic detection of falls.

A photovoltaic retinal prosthesis --- a flexible sheet of silicon pixels that convert light into electrical signals that can be picked up by neurons in the eye. A scanning-electron micrograph shows the implant in a pig’s eye. (Credit: Nature Photonics/Stanford)

Using tiny solar-panel-like cells surgically placed underneath the retina, scientists at the Stanford University School of Medicine have devised a system that may someday restore sight to people who have lost vision because of certain types of degenerative eye diseases.

This device — a new type of retinal prosthesis — involves a specially designed pair of goggles, which are equipped with a miniature camera and a pocket PC designed to process the visual data stream. The resulting images would be displayed on a liquid crystal microdisplay embedded in the goggles, similar to what’s used in video goggles for gaming, corresponding to approximately 30 degrees of visual field .

Unlike the regular video goggles, though, the images would be beamed from the LCD using laser pulses of near-infrared light to a photovoltaic array on a silicon chip  — one-third as thin as a strand of hair — implanted beneath the retina. It would have 25 micron (millionths of a meter, about 1/1000th of an inch) pixels, each containing a ~10 micron stimulating electrode.

Electric currents from the photodiodes on the chip would then trigger signals in the retina, which then flow to the brain, enabling a patient to regain vision.

The retinal chip is approximately 3 mm in diameter, corresponding to 10 degrees of visual field. The 30 degree visual field is accessible by eye scanning.

A portable computer processes video images captured by a head-mounted camera. Video goggles then project these images onto the retina using pulsed infrared (880–915 nm) illumination. Electric currents from the photodiodes on the chip then trigger signals in the retina that then flow to the brain, enabling a patient to regain vision. (Credit: K. Mathieson et al./Keith Mathieson et al./Nature Photonics)

Scientists tested the photovoltaic stimulation using the prosthetic device’s diode arrays in rat retinas in vitro and how they elicited electric responses, which are widely accepted indicators of visual activity, from retinal cells . The scientists are now testing the system in live rats, taking both physiological and behavioral measurements, and are hoping to find a sponsor to support tests in humans.

There are several other retinal prostheses being developed, and at least two of them are in clinical trials. A device made by the Los Angeles-based company Second Sight was approved in April for use in Europe, and another prosthesis-maker, a German company called Retina Implant AG, announced earlier this month results from its clinical testing in Europe.

Unlike these other devices — which require coils, cables or antennas inside the eye to deliver power and information to the retinal implant — the Stanford device uses near-infrared light to transmit images, thereby avoiding any need for wires and cables, and making the device thin and easily implantable.

“The current implants are very bulky, and the surgery to place the intraocular wiring for receiving, processing and power is difficult,” said Daniel Palanker, PhD, associate professor of ophthalmology. The device developed by his team, he noted, has virtually all of the hardware incorporated externally into the goggles. “The surgeon needs only to create a small pocket beneath the retina and then slip the photovoltaic cells inside it.” What’s more, one can tile these photovoltaic cells in larger numbers inside the eye to provide a wider field of view than the other systems can offer, he added.

The current design allows for 178 pixels per square millimeter. By comparison, the first retinal prosthesis to go to market, made by Second Sight of Sylmar, California, has 60 pixels in total and requires bulkier hardware.

However, thousands of pixels are likely to be required for functional restoration of sight, such as reading and face recognition, Palanker said on his Stanford page.

Conceptual diagram of the photovoltaic pixels with pillar electrodes (1) penetrating into the inner nuclear layer. The return electrodes (2) are located in the plane of the photodiodes. (Credit: Daniel Palanker)

Stanford University holds patents on two technologies used in the system, and Palanker and colleagues would receive royalties from the licensing of these patents.

Clinical trials are expected in a few years.

A prosthesis for retinal degenerative diseases

The proposed prosthesis is intended to help people suffering from retinal degenerative diseases, such as age-related macular degeneration and retinitis pigmentosa. The former is the foremost cause of vision loss in North America, and the latter causes an estimated 1.5 million people worldwide to lose sight, according to the nonprofit group Foundation Fighting Blindness.

In these diseases, the retina’s photoreceptor cells slowly degenerate, ultimately leading to blindness. But the inner retinal neurons that normally transmit signals from the photoreceptors to the brain are largely unscathed. Retinal prostheses are based on the idea that there are other ways to stimulate those neurons.

The Stanford device uses near-infrared light, which has longer wavelength than normal visible light. It’s necessary to use such an approach because people blinded by retinal degenerative diseases still have photoreceptor cells, which continue to be sensitive to visible light. “To make this work, we have to deliver a lot more light than normal vision would require,” said Palanker. “And if we used visible light, it would be painfully bright.” Near-infrared light isn’t visible to the naked eye, though it is “visible” to the diodes that are implanted as part of this prosthetic system, he said.

For this study, Palanker and his team fabricated a chip about the size of a pencil point that contains hundreds of these light-sensitive diodes. To test how these chips responded, the researchers used retinas from both normal rats and blind rats that serve as models of retinal degenerative disease. The scientists placed an array of photodiodes beneath the retinas and placed a multi-electrode array above the layer of ganglion cells to gauge their activity. The scientists then sent pulses of light, both visible and near-infrared, to produce electric current in the photodiodes and measured the response in the outer layer of the retinas.

In the normal rats, the ganglions were stimulated, as expected, by the normal visible light, but they also presented a similar response to the near-infrared light: That’s confirmation that the diodes were triggering neural activity.

In the degenerative rat retinas, the normal light elicited little response, but the near-infrared light prompted strong spikes in activity roughly similar to what occurred in the normal rat retinas. “They didn’t respond to normal light, but they did to infrared,” said Palanker. “This way the sight is restored with our system.” He noted that the degenerated rat retinas required greater amounts of near-infrared light to achieve the same level of activity as the normal rat retinas.

While there was concern that exposure to such doses of near-infrared light could cause the tissue to heat up, the study found that the irradiation was still one-hundredth of the established ocular safety limit.

Since completing the study, Palanker and his colleagues have implanted the photodiodes in rats’ eyes and been observing and measuring their effect for the last six months. He said preliminary data indicates that the visual signals are reaching the brain in normal and in blind rats, though the study is still under way.

While this and other devices could help people to regain some sight, the current technologies do not allow people to see color, and the resulting vision is far from normal, Palanker said.

Ref.: Keith Mathieson et al., Photovoltaic retinal prosthesis with high pixel density, Nature Photonics, 2012, DOI: 10.1038/nphoton.2012.104