The hydrophobic fabric repels water except where stitched with channels (credit: UC Davis)

Waterproof fabrics that whisk away sweat could be the latest application of microfluidic technology developed by bioengineers at the University of California, Davis.

The new fabric works like human skin, forming excess sweat into droplets that drain away by themselves, said inventor Tingrui Pan, professor of biomedical engineering.

One area of research in Pan’s Micro-Nano Innovations Laboratory at UC Davis is a field known as microfluidics, which focuses on making “lab on a chip” devices that use tiny channels to manipulate fluids. Pan and his colleagues are developing such systems for applications like medical diagnostic tests.

Graduate students Siyuan Xing and Jia Jiang developed a new textile microfluidic platform using hydrophilic (water-attracting) threads stitched into a highly water-repellent fabric. They were able to create patterns of threads that suck droplets of water from one side of the fabric, propel them along the threads and expel them from the other side.

“We intentionally did not use any fancy microfabrication techniques so it is compatible with the textile manufacturing process and very easy to scale up,” said Xing, lead graduate student on the project.

Bio-inspired sweat-removal fabrics (credit: Siyuan Xing and Tingrui Pan/UC Davis)

It’s not just that the threads conduct water through capillary action. The water-repellent properties of the surrounding fabric also help drive water down the channels.

Unlike conventional fabrics, the water-pumping effect keeps working even when the water-conducting fibers are completely saturated, because of the sustaining pressure gradient generated by the surface tension of droplets.

The rest of the fabric stays completely dry and breathable. By adjusting the pattern of water-conducting fibers and how they are stitched on each side of the fabric, the researchers can control where sweat is collected and where it drains away on the outside.

Workout enthusiasts, athletes and clothing manufacturers are all interested in fabrics that remove sweat and let the skin breathe. Cotton fibers, for example, wick away sweat — but during heavy exercise, cotton can get soaked, making it clingy and uncomfortable.

The work was funded in part by the National Science Foundation.

Salamander (credit: Scott Camazine/Wikimedia Commons)

Salamanders’ immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists have found.

In research published in the Proceedings of the National Academy of Sciences (open access), researchers from the Australian Regenerative Medicine Institute (ARMI) at Monash University found that when immune cells known as macrophages were systemically removed, salamanders lost their ability to regenerate a limb and instead formed scar tissue.

Lead researcher, Dr James Godwin, a Fellow in the laboratory of ARMI Director Professor Nadia Rosenthal, said the findings brought researchers a step closer to understanding what conditions were needed for regeneration.

“Previously, we thought that macrophages were negative for regeneration, and this research shows that that’s not the case. If the macrophages are not present in the early phases of healing, regeneration does not occur,” Dr Godwin said.

“Now, we need to find out exactly how these macrophages are contributing to regeneration. Down the road, this could lead to therapies that tweak the human immune system down a more regenerative pathway.”

Perfect regeneration

Salamanders deal with injury in a remarkable way. The end result is the complete functional restoration of any tissue, on any part of the body including organs. The regenerated tissue is scar free and almost perfectly replicates the injury site before damage occurred.

“We can look to salamanders as a template of what perfect regeneration looks like,” Godwin said.

Aside from “holy grail” applications, such as healing spinal cord and brain injuries, Godwin believes that studying the healing processes of salamanders could lead to new treatments for a number of common conditions, such as heart and liver diseases, which are linked to fibrosis or scarring. Promotion of scar-free healing would also dramatically improve patients’ recovery following surgery.

There are indications that there is the capacity for regeneration in a range of animal species, but it has, in most cases been turned off by evolution. “Some of these regenerative pathways may still be open to us. We may be able to turn up the volume on some of these processes,” Dr Godwin said.

“We need to know exactly what salamanders do and how they do it well, so we can reverse-engineer that into human therapies.”

(Credit: iStockphoto)

Activating an enzyme known to play a role in the anti-aging benefits of calorie restriction delays the loss of brain cells and preserves cognitive function in mice, according to a study published in the May 22 issue of The Journal of Neuroscience.

The findings could one day guide researchers to discover drug alternatives that slow the progress of age-associated impairments in the brain.

Li-Huei Tsai — director of the Picower Institute for Learning and Memory and Picower Professor of Neuroscience at MIT — along with postdoc Johannes Gräff and others at MIT have confirmed that caloric restriction delays nerve cell loss and they found that a drug that activates SIRT1 produces the same effects.

Previous studies have shown that reducing calorie consumption extends the lifespan of a variety of species and decreases the brain changes that often accompany aging and neurodegenerative diseases such as Alzheimer’s. There is also evidence that caloric restriction activates an enzyme called Sirtuin 1 (SIRT1), which studies suggest offers some protection against age-associated impairments in the brain.

“There has been great interest in finding compounds that mimic the benefits of caloric restriction that could be used to delay the onset of age-associated problems and/or diseases,” says Dr. Luigi Puglielli, who studies aging at the University of Wisconsin, Madison, and was not involved in this study. “If proven safe for humans, this study suggests such a drug could be used as a preventive tool to delay the onset of neurodegeneration associated with several diseases that affect the aging brain.”

In the study, Tsai’s team first decreased the normal diets of mice genetically engineered to rapidly undergo changes in the brain associated with neurodegeneration by 30 percent. Following three months on the diet, the mice completed several learning and memory tests. “We not only observed a delay in the onset of neurodegeneration in the calorie-restricted mice, but the animals were spared the learning and memory deficits of mice that did not consume reduced-calorie diets,” Tsai says.

Curious if they could recreate the benefits of caloric restriction without changing the animals’ diets, the scientists gave a separate group of mice a drug that activates SIRT1. Similar to what the researchers found in the mice exposed to reduced-calorie diets, the mice that received the drug had less cell loss and better cellular connectivity than the mice that did not receive the drug. Additionally, the mice that received the drug treatment performed as well as normal mice in learning and memory tests.

“The question now is whether this type of treatment will work in other animal models, whether it’s safe for use over time, and whether it only temporarily slows down the progression of neurodegeneration or stops it altogether,” Tsai says.

The research was supported by the National Institute on Aging and the Swiss National Science Foundation.

IBM Watson Solutions VP Stephen Gold interacts with the new IBM Watson Engagement Advisor, which uses cloud-delivered mobile and online chat technology to assist businesses’ customers, anytime and anywhere (credit: Jon Simon/Feature Photo Service for IBM)

Now customers can access Watson’s question-answering power directly.

IBM has unveiled the IBM Watson Engagement Advisor, a cognitive computing assistant that “learns, adapts and understands a company’s data quickly and easily,” according to IBM.

The IBM Watson Engagement Advisor‘s “Ask Watson” feature can quickly help address customers’ questions, offer feedback to guide their purchase decisions, and troubleshoot their problems.

No more “dial one for….”

The “Ask Watson” feature greets customers and offers help via any channel — through a website chat window or a mobile push alert, etc., saving consumers the hassle of performing searches, combing through websites and forums, or waiting endlessly for a response about the information they need.

Calling upon IBM’s Big Data Analytics technologies, IBM Watson retrieves data about customers to help ensure interactions are tailored to their needs, and search its corpus of stored information for the best solutions.

Leading brands trying it out include ANZ, Celcom, IHS, Nielsen and Royal Bank of Canada.

IBM Watson can now “proactively engage with a business’ customers, and continuously learn from interactions, anytime and anywhere, providing fast, more accurate and personalized interactions,” the announcement says.

Consider these findings:

• Millennial consumers will comprise nearly half of the workforce by 2020 — using paychecks for major purchases that require top-flight customer service — from cars to insurance policies.
• There will be more than 10 billion mobile devices by 2016, outpacing the human population.
• An IBM study of 1,700 chief marketing officers (CMOs) reveals that 65 percent of CMOs feel under-prepared for the growth of choices that today’s empowered consumers have for communications channels, such as smart phones and tablets.

IBM says that since its television debut, IBM Watson is smarter, faster and smaller — having gained a 240 percent improvement in system performance, and a reduction in physical requirements by 75 percent. The cognitive computing system can now be run on a single Power 750 server using Linux, transitioning from its original size of a master bedroom to that of four pizza boxes. Businesses that use IBM Watson can have the solution up and running quickly using a cloud computing environment, or deploy the technology on-premise.

How IBM Watson transforms the customer-disservice experience

The state of today’s customer engagement leaves much room for improvement. 270 billion customer service calls are handled annually, with roughly 50 percent unresolved, which for businesses means an increase in cost per escalated call by three times. In hindsight, 61 percent of those calls could have been resolved with better access to information.

Forrester’s 2012 Customer Experience Index revealed only 37 percent of brands received good or excellent customer experience index scores, while 64 percent received a rating of “OK,” “poor” or “very poor” from their customers.

Making matters more urgent for brands is the imminent spike in Millennial consumers who are expanding their footprint in today’s economy, using paychecks for insurance, bank accounts and telecom plans. Their expectations for brands: fast and personalized service on the go, via mobile device.

The IBM Watson Engagement Advisor will also help brands manage their existing customer engagement functions, by reducing burdens faced by call and e-service centers that struggle to keep up with skyrocketing demand.

Part of Alice’s optical parametric amplifier receiver. This receiver enables her to obtain the quantum-illumination performance advantage that ensures Bob’s communication to her is immune to Eve’s passive eavesdropping. (Credit: Zheshen Zhang et al./MIT)

Researchers in the Optical and Quantum Communications Group at MIT’s Research Laboratory of Electronics (RLE) have experimentally demonstrated a new quantum communication protocol that solves two basic problems with achieving practical quantum encryption.

Quantum key distribution (QKD) requires the inefficient transmission of a huge number of bits for each one that’s successfully received. And QKD depends on the properties of individual photons, so it’s very vulnerable to signal loss, which is inevitable over large enough distances — they generally work across distances of only 100 miles or so.

The new protocol is much more resilient to signal loss than QKD, and it sends only one bit for every one received.

At present, the protocol does have one major caveat: It’s secure only against so-called passive eavesdroppers, who simply siphon light from an optical transmission, and not against active eavesdroppers, who maliciously inject their own light into a communication channel. Security against passive eavesdropping is probably adequate for some optical communication systems, but if the researchers can figure out how to thwart active eavesdroppers, too, their protocol could be used to secure optical data transmission over long distances.

Cascading correlations

Like all quantum information schemes, the new protocol exploits the central mystery of quantum physics: the ability of tiny particles of matter to inhabit mutually exclusive states at the same time. Electrons, for instance, have a property called spin, which describes how they act in a magnetic field. Spin can be either up or down, but it can also be in a strange quantum state known as superposition, in which it’s up and down simultaneously.

According to Jeffrey Shapiro, the Julius A. Stratton Professor of Electrical Engineering and one of the co-directors of the Optical and Quantum Communications Group, quantum particles are capable of a greater degree of correlation than objects described by classical physics. A coin, for instance, can be either face-up or face-down. If you glue a second coin to it, face-to-face, the states of the two coins are correlated: If one is up, the other is down, and vice versa.

In the same way, if two electrons are orbiting the nucleus of an atom at the same distance, their spins are correlated: If one is up, the other must be down. But there’s a third possibility: If one is up and down at the same time, so is the other.

This kind of mutual dependency, even in particles separated by great distances, is known as entanglement. But entanglement is very fragile: It begins to break down as soon as particles start interacting with their immediate environments. The key to the new protocol, Shapiro explains, is that even if the entanglement between two light beams breaks down, and their degree of correlation falls back within classical limits, it can still remain much higher than it would be if the beams had a merely classical correlation to begin with.

Bring the noise

Following cryptographic convention, the RLE researchers describe their protocol in terms of a secure communication between Alice and Bob, with an eavesdropper, named Eve, trying to listen in. Alice creates two entangled light beams and sends one of them to Bob, keeping the other one circulating locally.

“In classical physics, there’s a maximum amount of correlation you can get between two events,” Shapiro says. In the new protocol, however, the entangled beams “have a correlation that exceeds — by orders of magnitude — the classical limit.”

As one of those beams travels toward Bob, interactions with the environment begin to break the entanglement, introducing degradations of signal quality that engineers call “noise.” Bob then adds information to the beam, amplifies it — which adds much more noise — and sends it back. Alice uses the beam she kept circulating locally to decode Bob’s transmission.

Eve, on the other hand, extracts some of the signal that Alice sends Bob and uses that to decode Bob’s transmission. Because Bob’s transmission is so noisy, its correlation with Eve’s sample signal is much lower than it is with the signal Alice kept.

“My experiment can show for the communication between Alice and Bob, if Bob sends one megabit of information, about one bit gets flipped,” says Zheshen Zhang, a postdoc at RLE and first author on the new paper. “For the eavesdropper, about half of the bits get flipped.”

“The first distinction between this and what other people have done in the past is that Jeff’s protocol is a direct secure-communication protocol,” says Saikat Guha, a senior scientist at Raytheon subsidiary BBN Technologies who works on quantum optical communications and imaging. “This is not a key distribution protocol.”

As for whether the system will work over long distances, “we don’t have all the answers yet, but this does seem to have better promise than some of the standard QKD protocols,” Guha says. “In the standard QKD protocols, one big requirement is to have quantum repeaters, which are devices that are not yet available. People are working on it, but there aren’t any quantum repeaters. So you can’t do standard QKD over standard fiber for more than a couple hundred kilometers at the most.”

Nelumbo nucifera from China, more commonly known as the “sacred lotus” (credit: Jane Shen-Miller/UCLA)

A team of 70 scientists from the U.S., China, Australia and Japan reports having sequenced and annotated more than 86 percent of the genome of the “sacred lotus,” which is believed to have a powerful genetic system that repairs genetic defects, and may hold secrets about aging successfully.

The Nelumbo nucifera plant is revered in China and elsewhere as a symbol of spiritual purity and longevity.

“Molecular biologists can now more easily study how its genes are turned on and off during times of stress and why this plant’s seeds can live for 1,300 years,” said Jane Shen-Miller, one of three corresponding authors of the research and a senior scientist with UCLA‘s Center for the Study of Evolution and the Origin of Life. This is a step toward learning what anti-aging secrets the sacred lotus plant may offer.”

The research was just published in the journal Genome Biology (open access).

Shen-Miller said the lotus’ genetic repair mechanisms could be very useful if they could be transferred to humans or to crops — such as rice, corn and wheat — whose seeds have life spans of only a few years. “If our genes could repair disease as well as the lotus’ genes, we would have healthier aging. We need to learn about its repair mechanisms, and about its biochemical, physiological and molecular properties, but the lotus genome is now open to everybody.”

How the lotus repair mechanism works

In the early 1990s, Shen-Miller led a UCLA research team that recovered a viable lotus seed that was almost 1,300 years old from a lake bed in northeastern China. It was a remarkable discovery, given that many other plant seeds are known to remain viable for just 20 years or less.

In 1996, Shen-Miller led another visit to China. Working in Liaoning province, her team collected about 100 lotus seeds — most were approximately 450 to 500 years old — with help from local farmers. To the researchers’ surprise, more than 80 percent of the lotus seeds that were tested for viability germinated. That indicated that the plant must have a powerful genetic system capable of repairing germination defects arising from hundreds of years of aging, Shen-Miller said.

Understanding how the lotus repair mechanism works — and its possible implications for human health — is essentially a three-step process, said Crysten Blaby-Haas, a UCLA postdoctoral scholar in chemistry and biochemistry and co-author of the research. “Knowing the genome sequence was step one. Step two would be identifying which of these genes contributes to longevity and repairing genetic damage. Step three would be potential applications for human health, if we find and characterize those genes. The genome sequence will aid in future analysis.

“The next question is what are these genes doing, and the biggest question is how they contribute to the longevity of the lotus plant and its other interesting attributes,” Blaby-Haas said. “Before this, when scientists studied the lotus, it’s almost as if they were blind; now they can see. Once you know the repertoire of genes, you have a foundation to study their functions.”

Whole-genome duplications — the doubling or tripling of an organism’s entire genetic endowment — are important events in plant evolution, Ming said. Some of the duplicated genes retain their original structure and function, and others gradually adapt and take on new functions. If those changes are beneficial, the genes persist; if they’re harmful, they disappear from the genome.

Shen-Miller said experts in aging and stress will be eager to study the lotus genes because of the plant’s extraordinary longevity. “The lotus can age for 1,000 years, and even survives freezing weather,” she said. “Its genetic makeup can combat stress. Most crops don’t have a very long shelf life. But starches and proteins in lotus seeds remain palatable and actively promote seed germination, even after centuries of aging.”

The lotus’ unusual genetics give it some unique survival skills. Its leaves repel grime and water, its flowers generate heat to attract pollinators and the coating of lotus fruit is covered with antibiotics and wax that ensure the viability of the seed it contains.

Blaby-Haas studied lotus gene families potentially involved in how plants metabolize metals. One family, in particular, caught her attention. “We found that the lotus has 16 of these genes, while most plants have only one or two,” Blaby-Haas said. “Either this is an extremely important protein in the lotus, which is why it needs so many copies, or the duplication allows a novel function to arise; we don’t know which is correct.”

These genes may be related to the unique environment of the lotus, which grows with its roots submerged in water, she said. (Lotus was a land plant that adapted to the water.)

The sacred lotus is known from the geologic record as early as 135 million years ago, when dinosaurs roamed the Earth, Shen-Miller said. It has been grown for at least 4,000 years in China, where every part of the plant has long been used in food and medicine.

(Credit: iStockphoto)

There are many neurons, especially in brain regions that perform sophisticated functions such as thinking and planning, that react in different ways to a wide variety of things.

MIT neuroscientist Earl Miller first noticed these unusual activity patterns about 20 years ago, while recording the electrical activity of neurons in animals that were trained to perform complex tasks.

“We started noticing early on that there are a whole bunch of neurons in the prefrontal cortex that can’t be classified in the traditional way of one message per neuron,” recalls Miller, the Picower Professor of Neuroscience at MIT and a member of MIT’s Picower Institute for Learning and Memory.

In a paper appearing in Nature on May 19, Miller and colleagues at Columbia University report that these neurons are essential for complex cognitive tasks, such as learning new behavior. The Columbia team, led by the study’s senior author, Stefano Fusi, developed a computer model showing that without these neurons, the brain can learn only a handful of behavioral tasks.

“You need a significant proportion of these neurons,” says Fusi, an associate professor of neuroscience at Columbia. “That gives the brain a huge computational advantage.”

Miller and other neuroscientists who first identified this neuronal activity observed that while the patterns were difficult to predict, they were not random. “In the same context, the neurons always behave the same way. It’s just that they may convey one message in one task, and a totally different message in another task,” Miller says.

For example, a neuron might distinguish between colors during one task, but issue a motor command under different conditions.

Miller and colleagues proposed that this type of neuronal flexibility is key to cognitive flexibility, including the brain’s ability to learn so many new things on the fly. “You have a bunch of neurons that can be recruited for a whole bunch of different things, and what they do just changes depending on the task demands,” he says.

At first, that theory encountered resistance “because it runs against the traditional idea that you can figure out the clockwork of the brain by figuring out the one thing each neuron does,” Miller says.

For the new Nature study, Fusi and colleagues at Columbia created a computer model to determine more precisely what role these flexible neurons play in cognition, using experimental data gathered by Miller and his former grad student, Melissa Warden. That data came from one of the most complex tasks that Miller has ever trained a monkey to perform: The animals looked at a sequence of two pictures and had to remember the pictures and the order in which they appeared.

During this task, the flexible neurons, known as “mixed selectivity neurons,” exhibited a great deal of nonlinear activity — meaning that their responses to a combination of factors cannot be predicted based on their response to each individual factor (such as one image).

Expanding capacity

Fusi’s computer model revealed that these mixed selectivity neurons are critical to building a brain that can perform many complex tasks. When the computer model includes only neurons that perform one function, the brain can only learn very simple tasks. However, when the flexible neurons are added to the model, “everything becomes so much easier and you can create a neural system that can perform very complex tasks,” Fusi says.

The flexible neurons also greatly expand the brain’s capacity to perform tasks. In the computer model, neural networks without mixed selectivity neurons could learn about 100 tasks before running out of capacity. That capacity greatly expanded to tens of millions of tasks as mixed selectivity neurons were added to the model. When mixed selectivity neurons reached about 30 percent of the total, the network’s capacity became “virtually unlimited,” Miller says — just like a human brain.

Mixed selectivity neurons are especially dominant in the prefrontal cortex, where most thought, learning and planning takes place. This study demonstrates how these mixed selectivity neurons greatly increase the number of tasks that this kind of neural network can perform, says John Duncan, a professor of neuroscience at Cambridge University.

“Especially for higher-order regions, the data that have often been taken as a complicating nuisance may be critical in allowing the system actually to work,” says Duncan, who was not part of the research team.

Miller is now trying to figure out how the brain sorts through all of this activity to create coherent messages. There is some evidence suggesting that these neurons communicate with the correct targets by synchronizing their activity with oscillations of a particular brainwave frequency.

“The idea is that neurons can send different messages to different targets by virtue of which other neurons they are synchronized with,” Miller says. “It provides a way of essentially opening up these special channels of communications so the preferred message gets to the preferred neurons and doesn’t go to neurons that don’t need to hear it.”

The research was funded by the Gatsby Foundation, the Swartz Foundation and the Kavli Foundation.

Intermediate age-related macular degeneration (credit: Wikimedia Commons)

Advanced Cell Technology, Inc. (ACT) has confirmed that the vision of a patient enrolled in a clinical investigation of the company’s retinal pigment epithelial (RPE) cells derived from human embryonic stem cells (hESCs) has improved from 20/400 to 20/40 following treatment.

ACT is currently enrolling patients in three clinical trials in the U.S. and Europe for treatment of Stargardt’s macular dystrophy (SMD) and dry age-related macular degeneration (dry AMD) with hESC-derived RPE cells. These trials are prospective, open-label studies, designed to determine the safety and tolerability of hESC-derived RPE cells following sub-retinal transplantation into patients with dry AMD or SMD at 12 months, the study’s primary endpoint.

Philip Rosedale, founder of once-popular virtual world Second Life, has created a new company called High Fidelity. As suggested by the video above and the blog, the company is developing more natural ways for avatars to communicate (with heads and hand movements, for example) and with low latency (faster response time).

“Imagine holding your phone and being able to twist and move your avatar’s hand. Kinda like turning any phone (with sensors) into a Wii controller,” says cofouinder Ryan Downe. “Low and behold when we plugged our Glass in and tried to run the Android app from our IDE, Glass showed up as a device and it “just worked.” They are also experimenting with Oculus Rift.

As Downe notes, “the most immersive virtual worlds fall flat when trying to deliver the emotional data from real world facial expressions and body language.”

Developing….

Non-invasive, neuron-specific localized stimulation by near-IR fiber optic beam (red) vs. invasive, non-localized stimulation by blue light (credit: S. Mohanty/UT Arlington)

A new tool that could help map and track the interactions between neurons in different areas of the brain is being developed by University of Texas Arlington assistant professor of physics Samarendra Mohanty.

The technology would be useful in the BRAIN (Brain Research Through Advancing Innovative Neurotechnologies) mapping initiative.

This new method, which uses a fiber-optic, two-photon, optogenetic stimulator, has been used on human cells in a laboratory, but is also expected to work in vivo. Optogenetic stimulation avoids damage to living tissue by using light to stimulate neurons instead of the electric pulses used in past research.

“Scientists have spent a lot of time looking at the physical connections between different regions of the brain. But that information is not sufficient unless we examine how those connections function,” Mohanty said. “That’s where two-photon optogenetics comes into play. This is a tool not only to control the neuronal activity but to understand how the brain works.”

How it works

(a) Schematic of conventional two-photon stimulation scanning pattern of targeted cell with laser beam delivered by microscope. (b) Schematic of fiber-optic two-photon activation. (Credit: S. Mohanty et al./Optics Letters)

The tiny tool builds on Mohanty’s previous discovery that near-infrared light can be used to stimulate an opsin (a light-sensitive protein) introduced into neurons in the brain. Most opsins are currently activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth. This new method could also show how different parts of the brain react when a linked area is stimulated, Mohanty said.

The two-photon optogenetic stimulation involves introducing the gene for an opsin called ChR2 into a sample of excitable cells (neurons in this case). A fiber-optic infrared beam of light can then be used to precisely excite the neurons in a tissue circuit. Researchers can then observe responses in the excited area as well as other parts of the neural circuit. In living subjects, scientists could also observe the behavioral outcome, Mohanty said.

Mohanty’s method of using low-energy near-infrared light (which penetrates tissue better) also enables more precision and a deeper penetration than the blue or green light beams often used in optogenetic stimulation, according to the Optics Letters paper.

Using fiber optics to deliver the two-photon optogenetic beam is another advance. Previous methods required bulky microscopes or complex scanning beams.

Mohanty’s group is collaborating with UT Arlington Department of Psychology assistant professor Linda Perrotti to apply this technology in living animals.

Testing the effects of transcranial random noise stimulation the prefrontal cortex. The orange plates are near-infrared spectroscopy devices, using infrared light to measure blood-flow changes. (Credit: Albert Snowball et al./Current Biology)

A harmless form of brain stimulation called transcranial random noise stimulation (TRNS) can help you learn math faster, researchers report.

“With just five days of cognitive training and noninvasive, painless brain stimulation, we were able to bring about long-lasting improvements in cognitive and brain functions,” says Roi Cohen Kadosh of the University of Oxford.

The enhancements to the speed of calculation- and memory-recall-based arithmetic learning held for a period of six months after training. No one knows exactly how TRNS works, but the researchers say the evidence suggests that it allows the brain to work more efficiently by making neurons fire more synchronously.

They applied the stimulation to the prefrontal cortex (DLPFC), a key area in arithmetic, and used near-infrared spectroscopy (NIRS) — using infrared light through the skull — to measure hemodynamic (blood flow) responses within the prefrontal cortex.

They tested two types of learning: drill learning 9ability to recall arithmetic
‘‘facts,’’ e.g., 4 x 8 = 32,  from memory (rote learning) and calculation (manipulation of numbers according to set procedures or algorithms involving one or several mathematical operations (e.g., 32 — 17 + 5 = 20),

Kadosh and his colleagues had shown previously that another form of brain stimulation called transcranial direct current stimulation (tDCS) could make people better at learning and processing new numbers. But, he says, TRNS is even less perceptible to those receiving it (people get a slight tingling on the scalp with tDCS).

TRNS also has the potential to help more people because it can improve mental arithmetic — the ability to add, subtract, or multiply a string of numbers in your head, for example — not just new number learning. Mental arithmetic is a more complex and challenging task, which more than 20 percent of people struggle with.

It might also be of particular help to those suffering with neurodegenerative illness, stroke, or learning difficulties, the researchers suggest.

Insulating states and superlattice minibands in a graphene/hBN heterostructure. Schematic of the moiré pattern for graphene (gray) on hBN (red and blue), for zero misalignment angle and an exaggerated lattice mismatch of ~10%. The moiré unit cell is outlined in green. Regions of local quasi-epitaxial alignment lead to opposite signs of the sublattice asymmetry, m(r), in different regions. (Credit: B. Hunt et al./Science)

It’s been a long-sought goal that has proved elusive: how to engineer a property called a band gap into graphene, needed to use graphene in making transistors and other electronic devices.

Now MIT researchers have taken a major step toward making graphene with a band gap.

The new technique involves placing a sheet of graphene — a carbon-based material whose structure is just one atom thick — on top of hexagonal boron nitride, another one-atom-thick material with similar properties. The resulting material adds the band gap while shares graphene’s amazing ability to conduct electrons.

Graphene is an extremely good conductor of electrons, while boron nitride is a good insulator, blocking the passage of electrons. “We made a high-quality semiconductor by putting them together,” Pablo Jarillo-Herrero, the Mitsui Career Development Assistant Professor of Physics at MIT, explains.

To make the hybrid material work, the researchers had to align, with near perfection, the atomic lattices of the two materials, which both consist of a series of hexagons.

The size of the hexagons (known as the lattice constant) in the two materials is almost the same, but not quite: Those in boron nitride are 1.8 percent larger. So while it is possible to line the hexagons up almost perfectly in one place, over a larger area the pattern goes in and out of register.

At this point, the researchers say they must rely on chance to get the angular alignment for the desired electronic properties in the resulting stack. However, the alignment turns out to be correct about one time out of 15, they say.

Tuning for different electronic properties

Graphene and boron nitride hexagons almost perfectly align, merging their properties (credit: B. Hunt et al./Science)

“The qualities of the boron nitride bleed over into the graphene,” Ashoori says. But what’s most “spectacular,” he adds, is that the properties of the resulting semiconductor can be “tuned” by just slightly rotating one sheet relative to the other, allowing for a spectrum of materials with varied electronic characteristics.

Others have made graphene into a semiconductor by etching the sheets into narrow ribbons, Ashoori says, but such an approach substantially degrades graphene’s electrical properties. By contrast, the new method appears to produce no such degradation.

The band gap created so far in the material is smaller than that needed for practical electronic devices; finding ways of increasing it will require further work, the researchers say.

“If … a large band gap could be engineered, it could have applications in all of digital electronics,” Jarillo-Herrero says. But even at its present level, he adds, this approach could be applied to some optoelectronic applications, such as photodetectors.

The results “surprised us pleasantly,” Ashoori says, and will require some explanation by theorists. Because of the difference in lattice constants of the two materials, the researchers had predicted that the hybrid’s properties would vary from place to place. Instead, they found a constant, and unexpectedly large, band gap across the whole surface.

In addition, Jarillo-Herrero says, the magnitude of the change in electrical properties produced by putting the two materials together “is much larger than theory predicts.”

Fractal properties

The MIT team also observed an interesting new physical phenomenon. When exposed to a magnetic field, the material exhibits fractal properties — known as a Hofstadter butterfly energy spectrum — that were described decades ago by theorists, but thought impossible in the real world. There is intense research in this area; two other research groups also report on these Hofstadter butterfly effects this week in the journal Nature.

Eva Andrei, a professor of physics at Rutgers University who was not involved in this work, says that until recently, “decades-old theoretical predictions of novel and surprising physical phenomena, expected to occur in 2-D electron systems [such as graphene], have lain dormant.” But the MIT team’s work clearly demonstrates some of these phenomena, she says.

“Perhaps most significant is their observation of a band gap in zero magnetic field,” she says. “The ability to induce a zero-field band gap in graphene may one day allow its use as a switch in transistor applications, providing a viable and inexpensive alternative to silicon electronics.”

The research included other researchers from the University of Arizona, the National Institute for Materials Science in Tsukuba, Japan, and Tohoku University in Japan. The work was funded by the U.S. Department of Energy, the Gordon and Betty Moore Foundation and the National Science Foundation.

Arrays of tree-like nanowires consisting of Si trunks and TiO2 branches facilitate solar water-splitting in a fully integrated artificial photosynthesis system (credit: Chong Liu et al./Lawrence Berkeley National Laboratory)

Lawrence Berkeley National Laboratory (Berkeley Lab) scientists have developed the first fully integrated nanosystem for artificial photosynthesis,  in which solar energy is directly converted into chemical fuels.

“Similar to the chloroplasts in green plants that carry out photosynthesis, our artificial photosynthetic system is composed of two semiconductor light absorbers, an interfacial layer for charge transport, and spatially separated co-catalysts,” says Peidong Yang, a chemist with Berkeley Lab’s Materials Sciences Division, who led this research.

“To facilitate solar water- splitting in our system, we synthesized tree-like nanowire  heterostructures, consisting of silicon trunks and titanium oxide branches. Visually, arrays of these nanostructures very much resemble an artificial forest.

“In natural photosynthesis, the energy of absorbed sunlight produces energized charge-carriers that execute chemical reactions in separate regions of the chloroplast,” Yang says. “We’ve integrated our nanowire nanoscale heterostructure into a functional system that mimics the integration in chloroplasts and provides a conceptual blueprint for better solar-to-fuel conversion efficiencies in the future.”

When sunlight is absorbed by pigment molecules in a chloroplast, an energized electron is generated that moves from molecule to molecule through a transport chain until ultimately it drives the conversion of carbon dioxide into carbohydrate sugars. This electron transport chain is called a “Z-scheme” because the pattern of movement resembles the letter Z on its side.

Yang and his colleagues also use a Z-scheme in their system, but they deploy two Earth-abundant and stable semiconductors — silicon and titanium oxide — loaded with co-catalysts and with an ohmic (low-resistance) contact inserted between them. Silicon was used for the hydrogen-generating photocathode and titanium oxide for the oxygen-generating photoanode.

The tree-like architecture was used to maximize the system’s performance. Like trees in a real forest, the dense arrays of artificial nanowire trees suppress sunlight reflection and provide more surface area for fuel-producing reactions.

Under simulated sunlight, this integrated nanowire-based artificial photosynthesis system achieved a 0.12-percent solar-to-fuel conversion efficiency. Although comparable to some natural photosynthetic conversion efficiencies, this rate will have to be substantially improved for commercial use.

This research was supported by the DOE Office of Science.

(Credit: Ulrich Lewark/KIT)

Researchers of the Fraunhofer Institute for Applied Solid State Physics and the Karlsruhe Institute for Technology have achieved wireless transmission of 40 Gbit/s over a distance of one kilometer, a new world record.

The technology may help provide future broadband access to the Internet in rural areas and places which are difficult to access.

Using a high frequency range between 200 and 280 GHz enables the fast transmission of large volumes of data and compact equipment. The design also allows for compatibility with fiber optic cables.

(Credit: Credit Suisse)

“The next big thing” is the rise of sophisticated wearable technology, such as smart watches, and other accessories, according to Credit Suisse semiconductor analysts, Fortune reports.

The wearables market is perhaps $3 billion to $5 billion today, rising to perhaps $30 billion to $50 billion over the next three to five years, the analysts forecast, adding that there may be upward of 15% of smartphone owners who end up buying a wearable, the authors opine, for perhaps 6% share of the total global electronics market.

The theory is that smartphones are going to be the hub connecting a proliferation of small, wireless devices that will become increasingly popular as software improves, component prices fall and new business uses emerge, says Fortune.

(Credit: Credit Suisse)

Headquarters of National Security Agency in Fort Meade, Maryland (credit: NSA)

A book Untangling the Web: A Guide to Internet Research (PDF) produced by the The National Security Agency to uncover intelligence hiding on the web has just been released by the NSA, following a FOIA request, Wired reports.

It offers advice for using search engines, the Internet Archive, and other online tools. But the most interesting is the chapter titled “Google Hacking.” For example: to find spreadsheets full of passwords in Russia? Type “filetype:xls site:ru login.” Even on websites written in non-English languages the terms “login,” “userid,” and “password” are generally written in English, the authors helpfully point out.

Misconfigured web servers “that list the contents of directories not intended to be on the web often offer a rich load of information to Google hackers,” the authors write, then offer a command to exploit these vulnerabilities — intitle: “index of” site:kr password.

Johnny Long has been talking about this for years at hacker conferences and in his book Google Hacking, Wired notes.

Neocortical column in Henry Markram’s Blue Brain project (Credit: Ecole Polytechnique Fédérale de Lausanne)

Henry Markram’s Human Brain Project (HBP), backed by 1 billion euros ($1.3 billion) funding Jan. 2013 from the European Commission, plans to integrate findings from the Allen Brain Atlas, the National Institutes of Health-funded Human Connectome Project, and the Brain (“Brain Activity Map”) project, Wired reports.

The HBP is an ambitious attempt to build a complete model of a human brain using predictive reverse-engineering and simulate it on an IBM Blue Gene supercomputer. Markram plans to give the EU an early working prototype of this system within just 18 months.

According to Brown University neuroscientist John Donoghue, one of the key figures in the Brain project, the HBP provides a means to test ideas that would emerge from Brain Activity Map data, and Brain Activity Map data would inform the models simulated in the Human Brain Project.

Markram is simultaneously doing four things: running a wet lab that amasses data through experiments on brain tissue, building a small-scale model and simulation of the rat neocortex (his initial Blue Brain project), running the Human Brain Project, and managing the simulation aspects of the HBP, building a virtual human brain from all the incoming data.

Markram thinks that the greatest potential achievement of his sim would be to determine the causes of the approximately 600 known brain disorders. He’ll achieve this by connecting his model brain to sensor-laden robotics and simultaneously recording what the robot is sensing and “thinking” as it explores physical environments, correlating audiovisual signals with simulated brain activity as the machine learns about the world.

A neuroscientist could then play back those perceptions as distorted by a damaged brain simulation. In an immersive 3-D environment, a researcher could see the world as a schizophrenic while watching what is going on in the schizophrenic’s mind.

Markram has hinted at the possibility that a sim embodied in a robot might become conscious. Hardwired with Markram’s model and given sufficient experience of the world, the machine could actually start thinking (à la Skynet and HAL 9000).

Blue Brain Project: speed vs. memory (credit: Henry Markram)

This flexible skin-like heart monitor is small enough to wear under a bandage (credit: L.A. Cicero/Stanford University)

Engineers combine layers of flexible materials into pressure sensors to create a wearable heart monitor thinner than a dollar bill. The skin-like device could one day provide doctors with a safer way to check the condition of a patient’s heart.

Zhenan Bao, a professor of chemical engineering at Stanford, has developed a heart monitor thinner than a dollar bill and no wider than a postage stamp.

The flexible skin-like monitor, worn under an adhesive bandage on the wrist, is sensitive enough to help doctors detect stiff arteries and cardiovascular problems.

The devices could one day be used to continuously track heart health and provide doctors a safer method of measuring a key vital sign for newborn and other high-risk surgery patients.

“The pulse is related to the condition of the artery and the condition of the heart,” said Bao, whose lab develops artificial skin-like materials. “The better the sensor, the better doctors can catch problems before they develop.”

Detecting pulse and blood pressure

The pulse is made up of two distinct peaks. The first, larger peak is from your heart pumping out blood. Shortly after a heartbeat, your lower body sends a reflecting wave back to your artery system, creating a smaller second peak. The relative sizes of these two peaks can be used by medical experts to measure your heart’s health.

“You can use the ratio of the two peaks to determine the stiffness of the artery, for example,” said Gregor Schwartz, a post-doctoral fellow and a physicist for the project. “If there is a change in the heart’s condition, the wave pattern will change.”

To make the heart monitor both sensitive and small, Bao’s team uses a thin middle layer of rubber covered with tiny pyramid bumps. Each mold-made pyramid is only a few microns across – smaller than a human red blood cell. When pressure is put on the device, the pyramids deform slightly, changing the size of the gap between the two halves of the device. This change in separation causes a measurable change in the electromagnetic field and the current flow in the device.

The more pressure placed on the monitor, the more the pyramids deform and the larger the change in the electromagnetic field. Using many of these sensors on a prosthetic limb could act like an electronic skin, creating an artificial sense of touch.

When the sensor is placed on someone’s wrist using an adhesive bandage, the sensor can measure that person’s pulse wave as it reverberates through the body.

The device is so sensitive that it can detect more than just the two peaks of a pulse wave. When engineers looked at the wave drawn by their device, they noticed small bumps in the tail of the pulse wave invisible to conventional sensors. Bao said she believes these fluctuations could potentially be used for more detailed diagnostics in the future.

 “In theory, this kind of sensor can be used to measure blood pressure,” said Schwartz. “Once you have it calibrated, you can use the signal of your pulse to calculate your blood pressure.”

Noninvasive continuous monitoring

This non-invasive method of monitoring heart health could replace devices inserted directly into an artery, called intravascular catheters. These catheters create a high risk of infection, making them impractical for newborns and high-risk patients.  So an external monitor like Bao’s could provide doctors a safer way to gather information about the heart, especially during infant surgeries.

Bao’s team is working with other Stanford researchers to make the device completely wireless. Using wireless communication, doctors could receive a patient’s minute-by-minute heart status via cell phone.

“For some patients with a potential heart disease, wearing a bandage would allow them to constantly measure their heart’s condition,” Bao said. “This could be done without interfering with their daily life at all, since it really just requires wearing a small bandage.”

Brain wiring (credit: eyewire.org)

When the hippocampus, the brain’s primary learning and memory center, is damaged, complex new neural circuits — often far from the damaged site — arise to compensate for the lost function, say life scientists from UCLA and Australia who have pinpointed the regions of the brain involved in creating those alternate pathways.

The researchers found that parts of the prefrontal cortex take over when the hippocampus is disabled. Their breakthrough discovery, the first demonstration of such neural-circuit plasticity, could potentially help scientists develop new treatments for Alzheimer’s disease, stroke, and other conditions involving damage to the brain.

Learning after brain damage — a surprising finding

(Credit: The University of Melbourne)

In the research,  UCLA‘s Michael Fanselow and Moriel Zelikowsky in collaboration with Bryce Vissel, a group leader of the neuroscience research program at Sydney’s Garvan Institute of Medical Research, conducted laboratory experiments with rats showing that the rodents were able to learn new tasks even after damage to the hippocampus.

While the rats needed additional training, they nonetheless learned from their experiences — a surprising finding.

“I expect that the brain probably has to be trained through experience,” said Fanselow, a professor of psychology and member of the UCLA Brain Research Institute, who was the study’s senior author. “In this case, we gave animals a problem to solve.”

After discovering the rats could, in fact, learn to solve problems, Zelikowsky, a graduate student in Fanselow’s laboratory, traveled to Australia, where she worked with Vissel to analyze the anatomy of the changes that had taken place in the rats’ brains. Their analysis identified significant functional changes in two specific regions of the prefrontal cortex.

Compensating for damage from Alzheimer’s

“Interestingly, previous studies had shown that these prefrontal cortex regions also light up in the brains of Alzheimer’s patients, suggesting that similar compensatory circuits develop in people,” Vissel said. “While it’s probable that the brains of Alzheimer’s sufferers are already compensating for damage, this discovery has significant potential for extending that compensation and improving the lives of many.”

The hippocampus, a seahorse-shaped structure where memories are formed in the brain, plays critical roles in processing, storing and recalling information. The hippocampus is highly susceptible to damage through stroke or lack of oxygen and is critically involved in Alzheimer’s disease, Fanselow said.

“Until now, we’ve been trying to figure out how to stimulate repair within the hippocampus,” he said. “Now we can see other structures stepping in and whole new brain circuits coming into being.”

Zelikowsky said she found it interesting that sub-regions in the prefrontal cortex compensated in different ways, with one sub-region — the infralimbic cortex — silencing its activity and another sub-region — the prelimbic cortex — increasing its activity.

“If we’re going to harness this kind of plasticity to help stroke victims or people with Alzheimer’s,” she said, “we first have to understand exactly how to differentially enhance and silence function, either behaviorally or pharmacologically. It’s clearly important not to enhance all areas. The brain works by silencing and activating different populations of neurons. To form memories, you have to filter out what’s important and what’s not.”

Complex behavior always involves multiple parts of the brain communicating with one another, with one region’s message affecting how another region will respond, Fanselow noted. These molecular changes produce our memories, feelings and actions.

“The brain is heavily interconnected — you can get from any neuron in the brain to any other neuron via about six synaptic connections,” he said. “So there are many alternate pathways the brain can use, but it normally doesn’t use them unless it’s forced to. Once we understand how the brain makes these decisions, then we’re in a position to encourage pathways to take over when they need to, especially in the case of brain damage.

“Behavior creates molecular changes in the brain; if we know the molecular changes we want to bring about, then we can try to facilitate those changes to occur through behavior and drug therapy,” he added. I think that’s the best alternative we have. Future treatments are not going to be all behavioral or all pharmacological, but a combination of both.”

The research was funded by the National Institute of Mental Health, part of the National Institutes of Health, and by the National Science Foundation.

MIT engineers have created synthetic biology circuits that can perform analog computations such as taking logarithms and square roots in living cells (cartoon) (credit: Ramiz Daniel et al./MIT)

By combining existing genetic “parts,” or engineered genes, in novel ways, MIT engineers have transformed bacterial cells into living calculators that can compute logarithms, divide, and take square roots, using three or fewer genetic parts.

The circuits perform those calculations in an analog fashion by exploiting natural biochemical functions that are already present in the cell rather than by reinventing them with digital logic.

This makes them more efficient than the digital circuits pursued by most synthetic biologists, according to MIT engineers Rahul Sarpeshkar and Timothy Lu, the two senior authors on the paper describing the circuits in the May 15 online edition of Nature.

“In analog you compute on a continuous set of numbers, which means it’s not just black and white, it’s gray as well,” says Sarpeshkar, an associate professor of electrical engineering and computer science and the head of the Analog Circuits and Biological Systems group at MIT

Analog computation would be particularly useful for designing cellular sensors for pathogens or other molecules, the researchers say. Analog sensing could also be combined with digital circuits to create cells that can take a specific action triggered by a threshold concentration of certain molecules.

“You could do a lot of upfront sensing with the analog circuits because they’re very rich and a relatively small amount of parts can give you a lot of complexity, and have that output go into a circuit that makes a decision — is this true or not?” says Lu, an assistant professor of electrical engineering and computer science and biological engineering.

Analog advantages 

Sarpeshkar has previously identified thermodynamic similarities between analog transistor circuits and the chemical circuits that take place inside cells. In 2011, he took advantage of those similarities to model biological interactions between DNA and proteins in an electronic circuit, using only eight transistors.

In the new Nature paper, Sarpeshkar, Lu and colleagues have done the reverse — mapping analog electronic circuits onto cells. Sarpeshkar has long advocated analog computing as a more efficient alternative to digital computation at the moderate precision of computation seen in biology. These analog circuits are efficient because they can take in a continuous range of inputs, and they exploit the natural continuous computing functions that are already present in cells. In the case of cells, that continuous input might be the amount of glucose present. In transistors, it’s a range of continuous input currents or voltages.

Digital circuits, meanwhile, represent every value as zero or one, ignoring the range of possibilities in between. This can be useful for creating circuits that perform logic functions such as AND, NOT and OR inside cells, which many synthetic biologists have done. These circuits can reveal whether or not a threshold level of a certain molecule is present, but not the exact amount of it.

Digital circuits also require many more parts, which can drain the energy of the cell hosting them. “If you build too many parts to make some function, the cell is not going to have the energy to keep making those proteins,” Sarpeshkar says.

Doing the math

Complex analog computation can be implemented by composing synthetic gene circuits. Here, an adder is built
by engineering two wide-dynamic-range, positive-slope logarithm circuits (modules outlined in red) to produce a common output, which is summed to yield the overall output. (credit: Ramiz Daniel et al./MIT/Nature)

To create an analog adding or multiplying circuit that can calculate the total quantity of two or more compounds in a cell, the researchers combined two circuits, each of which responds to a different input. In one circuit, a sugar called arabinose turns on a transcription factor that activates the gene that codes for green fluorescent protein (GFP). In the second, a signaling molecule known as AHL also turns on a gene that produces GFP. By measuring the total amount of GFP, the total amount of both inputs can be calculated.

To subtract or divide, the researchers swapped one of the activator transcription factors with a repressor, which turns off production of GFP when the input molecule is present. The team also built an analog square root circuit that requires just two parts, while a recently reported digital synthetic circuit for performing square roots had more than 100.

“Analog computation is very efficient,” Sarpeshkar says. “To create digital circuits at a comparable level of precision would take many more genetic parts.”

Another of the team’s circuits can perform division by calculating the ratio of two different molecules. Cells often perform this kind of computation on their own, which is critical for monitoring the relative concentrations of molecules such as NAD and NADH, which are frequently converted from one to the other as they help other cellular reactions take place.

“That ratio is important for controlling a lot of cellular processes, and the cell naturally has enzymes that can recognize those ratios,” Lu says. “Cells can already do a lot of these things on their own, but for them to do it over a useful range requires extra engineering.”

That extra engineering included modifying the circuits so that they can compute with inputs over a range of 1 to 10,000 — much wider than the range of a naturally occurring cell circuit.

The researchers are now trying to create analog circuits in nonbacterial cells, including mammalian cells. They are also working on expanding the library of genetic parts that can be incorporated into the circuits. “Right now we’re using three of the most commonly used transcription factors in biology, but we’d like to do this with additional parts and make this a generalizable platform so everyone else can use it,” Lu says.

“We have just scratched the surface of what sophisticated analog feedback circuits can do in living cells,” says Sarpeshkar, whose lab is working on building further new analog circuits in cells. He believes the new approach of what he terms “analog synthetic biology” will create a new set of fundamental and applied circuits that can dramatically improve the fine control of gene expression, molecular sensing, computation and actuation.

The research was funded by MIT Lincoln Laboratory, the Office of Naval Research and the National Science Foundation.

The chip at the heart of one of D-Wave’s computers (credit: D-Wave)

Google, in partnership with NASA and the Universities Space Research Association (USRA), has launched an initiative to investigate how quantum computing might lead to breakthroughs in machine learning, a branch of AI that focuses on construction and study of systems that learn from data..

The new lab will use the D-Wave Two quantum computer.A recent study (see “Which is faster: conventional or quantum computer?“) confirmed the D-Wave One quantum computer was much faster than conventional machines at specific problems.

The machine will be installed at the NASA Advanced Supercomputing Facility at the NASA Ames Research Center in Mountain View, California.

“We hope it helps researchers construct more efficient and more accurate models for everything from speech recognition, to web search, to protein folding,” said Hartmut Neven, Google director of engineering.

Hybrid solutions

“Machine learning is highly difficult. It’s what mathematicians call an ‘NP-hard’ problem,” he said. “Classical computers aren’t well suited to these types of creative problems. Solving such problems can be imagined as trying to find the lowest point on a surface covered in hills and valleys.

“Classical computing might use what’s called a ‘gradient descent’: start at a random spot on the surface, look around for a lower spot to walk down to, and repeat until you can’t walk downhill anymore. But all too often that gets you stuck in a “local minimum” — a valley that isn’t the very lowest point on the surface.

“That’s where quantum computing comes in. It lets you cheat a little, giving you some chance to ‘tunnel’ through a ridge to see if there’s a lower valley hidden beyond it. This gives you a much better shot at finding the true lowest point — the optimal solution.”

Google has already developed some quantum machine-learning algorithms, Neven said. “One produces very compact, efficient recognizers — very useful when you’re short on power, as on a mobile device. Another can handle highly polluted training data, where a high percentage of the examples are mislabeled, as they often are in the real world. And we’ve learned some useful principles: e.g., you get the best results not with pure quantum computing, but by mixing quantum and classical computing.”

The D-Wave Systems Fridge with Cryogenic Packaging (credit: Amherst College)

A computer science professor at Amherst College has conducted experiments to test the speed of a quantum computing system (from D-Wave) against conventional computing methods.

“Ours is the first paper to my knowledge that compares the quantum approach to conventional methods using the same set of problems,” says Catherine McGeoch, the Beitzel Professor in Technology and Society (Computer Science) at Amherst.

McGeoch, author of A Guide to Experimental Algorithmics (Cambridge University Press, 2012), has 25 years of experience setting up experiments to test various facets of computing speed.

D-Wave retained McGeoch as an outside consultant to help devise experiments that would test its machines against conventional computers and algorithms.

Thousands of times faster for specific problems

McGeoch says the calculations the D-Wave excels at involve a specific combinatorial optimization problem, comparable in difficulty to the more famous “traveling salesperson” problem that’s been a foundation of theoretical computing for decades.

Briefly stated, the traveling salesperson problem asks this question: given a list of cities and the distances between each pair of cities, what is the shortest possible route that visits each city exactly once and returns to the original city?

Questions like this apply to challenges such as shipping logistics, flight scheduling, search optimization, DNA analysis and encryption, and are extremely difficult to answer quickly. The D-Wave computer has the greatest potential in this area, McGeoch says.

D-Wave One systems being tested in the lab (credit: Amherst College)

“This type of computer is not intended for surfing the Internet, but it does solve this narrow but important type of problem really, really fast,” McGeoch says.

“There are degrees of what it can do. If you want it to solve the exact problem it’s built to solve, at the problem sizes I tested, it’s thousands of times faster than anything I’m aware of.

If you want it to solve more general problems of that size, I would say it competes – it does as well as some of the best things I’ve looked at. At this point it’s merely above average but shows a promising scaling trajectory.”

Whether the D-Wave computer will ever have mass market appeal is also difficult for McGeoch to assess. While the 439-qubit model she tested does have incredible computing power, there is that near-zero Kelvin chip operating temperature requirement that would make home or office use a chilly proposition. At present, she thinks the power of the D-Wave approach is too narrowly focused to be of much use to the average personal computer user.

D-Wave cryogenic packaging — fridge payload (credit: Amherst College)

“The founder of IBM famously predicted that only about five of his company’s first computers would be sold because he just didn’t see the need for that much computing power,” McGeoch says. “Who needs to solve those big problems now? I’d say it’s probably going to be big companies like Google and government agencies.”

And, while conventional approaches to solving these problems will likely continue to improve incrementally, this fast quantum approach has the potential to expand to larger variety of problems than it does now, McGeoch says.

“Within a year or two I think these quantum computing methods will solve more and bigger problems significantly faster than the best conventional computing options out there,” she says.

At the same time, she cautions that her first set of experiments represents a snapshot moment of the state of quantum computing versus conventional computing.

“This by no means settles the question of how fast the quantum computer is,” she says. “That’s going to take a lot more testing and a variety of experiments. It may not be a question that ever gets answered because there’s always going to be progress in both quantum and conventional computing.”

(Credit: Masahito Tachibana et al./Cell)

It was hailed some 15 years ago as the great hope for a biomedical revolution: production of patient-specific embryonic stem cells (ESCs) from cloning to create perfectly matched tissues that would someday cure ailments ranging from diabetes to Parkinson’s disease.

Since then, the approach has been enveloped in ethical debate. A paper published by Shoukhrat Mitalipov, a reproductive biology specialist at the Oregon Health and Science University in Beaverton, and his colleagues is sure to rekindle that debate, Nature News reports.

Therapeutic cloning, or somatic-cell nuclear transfer (SCNT), begins with the same process used to create Dolly, the famous cloned sheep, in 1996.

A donor cell from a body tissue such as skin is fused with an unfertilized egg from which the nucleus has been removed. The egg ‘reprograms’ the DNA in the donor cell to an embryonic state and divides until it has reached the early, blastocyst stage. The cells are then harvested and cultured to create a stable cell line that is genetically matched to the donor and that can become almost any cell type in the human body.

Mitalipov and his group began work on their new study last September, using eggs from young donors recruited through a university advertising campaign. In December, after some false starts, cells from four cloned embryos that Mitalipov had engineered began to grow. “It looks like colonies, it looks like colonies,” he kept thinking. Masahito Tachibana, a fertility specialist from Sendai, Japan, who is finishing a 5-year stint in Mitalipov’s laboratory, nervously sectioned the 1-millimetre-wide clumps of cells and transferred them to new culture plates, where they continued to grow — evidence of success. Mitalipov cancelled his holiday plans. “I was happy to spend Christmas culturing cells,” he says. “My family understood.”

The success came through minor technical tweaks. The researchers used inactivated Sendai virus (known to induce fusion of cells) to unite the egg and body cells, and an electric jolt to activate embryo development. When their first attempts produced six blastocysts but no stable cell lines, they added caffeine, which protects the egg from premature activation.

None of these techniques is new, but the researchers tested them in various combinations in more than 1,000 monkey eggs before moving on to human cells.

Public fears that the technology might be used to create human clones are a sticking point. The research might spark “cloning hysteria” that opponents of stem-cell research could capitalize on, says Bernard Siegel, executive director of the Genetics Policy Institute in Palm Beach, Florida.

(credit: César A. González)

University of California, Berkeley researchers have developed a device that uses wireless signals to provide real-time, non-invasive diagnoses of brain swelling or bleeding.

The device analyzes data from low energy, electromagnetic waves, similar to the kind used to transmit radio and mobile signals. It could potentially become a cost-effective tool for medical diagnostics and to triage injuries in areas where access to medical care, especially medical imaging, is limited.

The researchers tested a prototype in a small-scale pilot study of healthy adults and brain trauma patients admitted to a military hospital for the Mexican Army. The results from the healthy patients were clearly distinguishable from those with brain damage, and data for bleeding was distinct from those for swelling.

(credit: César A. González)

“There are large populations in Mexico and the world that do not have adequate access to advanced medical imaging, either because it is too costly or the facilities are far away,” said César A. González, a professor at the Instituto Politécnico Nacional, Escuela Superior de Medicina (National Polytechnic Institute’s Superior School of Medicine) in Mexico.

“This technology is inexpensive, it can be used in economically disadvantaged parts of the world and in rural areas that lack industrial infrastructure, and it may substantially reduce the cost and change the paradigm of medical diagnostics. We have also shown that the technology could be combined with cell phones for remote diagnostics.”

Boris Rubinsky, Professor of the Graduate School at UC Berkeley’s Department of Mechanical Engineering, who led the research team, noted that symptoms of serious head injuries and brain damage are not always immediately obvious, and for treatment, time is of the essence. For example, the administration of clot-busting medication for certain types of strokes must be given within three hours of the onset of symptoms.

“Some people might delay traveling to a hospital to get examined because it is an hour or more away or because it is exceedingly expensive,” said Rubinsky. “If people had access to an affordable device that could indicate whether there is brain damage or not, they could then make an informed decision about making that trip to a facility to get prompt treatment, which is especially important for head injuries.”

The researchers took advantage of the characteristic changes in tissue composition and structure in brain injuries. For brain edemas, swelling results from an increase in fluid in the tissue. For brain hematomas, internal bleeding causes the buildup of blood in certain regions of the brain. Because fluid conducts electricity differently than brain tissue, it is possible to measure changes in electromagnetic properties. Computer algorithms interpret the changes to determine the likelihood of injury.

The study involved 46 healthy adults, ages 18 to 48, and eight patients with brain damage, ages 27 to 70.

The engineers fashioned two coils into a helmet-like device, fitted over the heads of the study participants. One coil acts as a radio emitter and the other serves as the receiver.   Electromagnetic signals are broadcast through the brain from the emitter to the receiver.

“We have adjusted the coils so that if the brain works perfectly, we have a clean signal,” said Rubinsky. “Whenever there are interferences in the functioning of the brain, we detect them as changes in the received signal. We can tell from the changes, or ‘noises,’ what the brain injury is.”

Rubinsky noted that the waves are extremely weak, and are comparable to standing in a room with the radio or television turned on.

The device’s diagnoses for the brain trauma patients in the study matched the results obtained from conventional computerized tomography (CT) scans.

Diagnostics for the Aging brain

The tests also revealed some insights  into the aging brain. “With an increase in age, the average electromagnetic transmission signature of a normal human brain changes and approaches that of younger patients with a severe medical condition of hematoma in the brain,” said González.

“This suggests the potential for the device to be used as an indication for the health of the brain in older patients in a similar way in which measurements of blood pressure, ECG, cholesterol or other health markers are used for diagnostic of human health conditions.”

González started the research with the support of the University of California Institute for Mexico and the United States (UC MEXUS), an academic research program that supports collaborations between Mexico and the UC system, and Mexico’s Consejo Nacional de Ciencia y Tecnología (National Council of Science and Technology), the government agency promoting science and technology research and activities.

New Google Maps: search results are labeled directly on the map (credit: Google)

On Wednesday, Google unveiled a new Google Maps, by far the biggest redesign since it introduced Maps eight years ago, The New York Times reports.

When users who are logged into Google visit Maps, they will see the places they frequently visit highlighted, like restaurants, museums and their home. Google learns the places they go by drawing information from all of Google’s services — including search and Maps history, Google Plus posts and information in users’ Gmail in-boxes.

When users visit a new city, Google will recommend places to go based on their preferences and those of people with similar tastes. The maps change in real time, so if you click on a museum, other museums in the city pop up and the small roads and landmarks needed to navigate to that museum appear.

The new service is available only to people who sign up for it to start, It will come to mobile devices later.

Google Earth, which shows 3-dimensional satellite imagery, is now incorporated into the online version of Google Maps, instead of being accessible only as an app to download. Google can do this because of a new technology that renders graphics inside a browser, instead of downloading images from a server.

(Credit: Google)

Google revealed some new search tools on Wednesday at I/O, its annual developers conference, The New York Times reports. Taken together, they are another step toward Google’s trying to become the omnipotent, human-like “Star Trek” search engine that its executives say they want it to be.

When people ask Google certain questions, it will now try to predict the person’s follow-up questions and answer them, too. Ask for the population of India, for instance, and you will also get the population of China and the United States, because Google knows those are the most common follow-up questions.

This is an extension of Google’s knowledge graph — its semantic search product that aims to understand the meaning of things, not just keywords.

Google Now, the service that sends you information on traffic and weather before you even ask for it, is also digging deeper into our minds. Google is adding more entertainment alerts, like new music based on videos watched on YouTube, and turning Google Now into a robotic to-do list and a stronger competitor to Apple’s Siri.

Google is also trying to make search more conversational by encouraging people to talk to their phones and computers and hear answers out loud. Google announced that people can now talk to its Chrome browser to perform a search, by saying, “O.K. Google.” Google also uses location information to answer questions.

In another step to personalize search, Google is expanding its tool that plucks information from Gmail and presents it in search results.

“OK, Google…”: what this conversational experience will look like in Chrome on your desktops and laptops (credit: Google)

These images show differences in collagen buildup (which interferes with implants) in two tissue samples. Collagen is shown in blue. The left image shows a thick collagen wall (arrow) forming in the presence of a poly(2-hydroxyethyl methacrylate), a material that’s currently widely used for implantable devices. In contrast, collagen in the right image is more evenly dispersed in the tissue after the UW-engineered hydrogel has been implanted. (Credit: Lei Zhang/University of Washington)

University of Washington engineers have demonstrated in mice a way to prevent failure of implants and prostheses, using a synthetic hydrogel biomaterial that fully resists the body’s natural attack response to foreign objects.

Medical devices such as artificial heart valves, prostheses and breast implants could be coated with this polymer to prevent the body from rejecting an implanted object.

How medical implants fail

The body’s biological response to implanted devices — medical technologies that often cost millions to develop — has frustrated experts for years. After an implant, the body usually creates a protein wall around the medical device, cutting it off from the rest of the body. Scientists call this barrier a collagen capsule. Collagen is a protein that’s naturally found in our bodies, particularly in connective tissues such as tendons and ligaments.

If a device such as an artificial valve or an electrode sensor is blocked off from the rest of the body, it usually fails to work. Physicians and scientists have tried to minimize this, but they haven’t been able to eliminate it, said Buddy Ratner, co-author and a UW professor of bioengineering and of chemical engineering.

The foreign-body reaction occurs in response to implants made of many materials, including teflon, polyurethane, silicone rubber, polyethylene, poly(methyl methacrylate), poly(ethylene glycol) (PEG), Dacron, gold, titanium and alumina, including other hydrogels, such as poly(2-hydroxyethyl methacrylate) (PHEMA), the authors say in a Nature Biotechnology paper.

Improved hydrogel

Ratner’s collaborator and co-author Shaoyi Jiang, a UW professor of chemical engineering, and his team implanted an improved hydrogel polymer substance, known as poly(carboxybetaine methacrylate)
(PCBMA), into the bodies of mice.

A hydrogel is a flexible biomedical material that swells with water. It’s made from a polymer that deflects all proteins from sticking to its surface. (Scientists have found that proteins appearing on the surface of a medical implant are the first signs that a larger collagen wall will form.)

After three months, Jiang and his team found that collagen was loosely and evenly distributed in the tissue around the polymer, suggesting that the mice bodies didn’t even detect the polymer’s presence.

For humans, the first three weeks after an implant are the most critical, because by then the body will show signs of isolating the implant by building a collagen wall. If this hasn’t happened in the first several weeks, it’s likely the body won’t default to an attack response toward the object.

Human tests

UW researchers and others have worked for nearly 20 years to find a way to help the body accept implants. In 1996, the National Science Foundation-funded UW Engineered Biomaterials (UWEB) research center opened at the UW, with Ratner serving as director. Since that time, researchers have been trying to make a material that is invisible to the body’s immune response and could eliminate the body’s negative reaction to medical implants.

The UW researchers plan to test this material in humans, likely by working with manufacturers to coat an implantable device with the polymer, then measure its ability to ward off protein build-up.

The research was funded by the U.S. Office of Naval Research, UWEB and the UW Department of Chemical Engineering.

Salk scientists developed J147, a synthetic drug shown to improve memory and prevent brain damage in mice with Alzheimer’s disease (credit: Salk Institute for Biological Studies)

A drug developed by scientists at the Salk Institute for Biological Studies, known as J147, reverses memory deficits and slows Alzheimer’s disease in aged mice following short-term treatment.

The findings may pave the way to a new treatment for Alzheimer’s disease in humans.

“J147 is an exciting new compound because it really has strong potential to be an Alzheimer’s disease therapeutic by slowing disease progression and reversing memory deficits following short-term treatment,” says lead study author Marguerite Prior, a research associate in Salk’s Cellular Neurobiology Laboratory.

Despite years of research, there are no disease-modifying drugs for Alzheimer’s. Current FDA-approved medications, including Aricept, Razadyne and Exelon, offer only fleeting short-term benefits for Alzheimer’s patients, but they do nothing to slow the steady, irreversible decline of brain function that erases a person’s memory and ability to think clearly.

According to the Alzheimer’s Association, more than 5 million Americans are living with Alzheimer’s disease, the sixth leading cause of death in the country and the only one among the top 10 that cannot be prevented, cured or even slowed.

J147 was developed at Salk in the laboratory of David Schubert, a professor in the Cellular Neurobiology Laboratory. He and his colleagues bucked the trend within the pharmaceutical industry, which has focused on the biological pathways involved in the formation of amyloid plaques, the dense deposits of protein that characterize the disease.

Instead, the Salk team used living neurons grown in laboratory dishes to test whether their new synthetic compounds, which are based upon natural products derived from plants, were effective at protecting brain cells against several pathologies associated with brain aging. From the test results of each chemical iteration of the lead compound, they were able to alter their chemical structures to make them much more potent. Although J147 appears to be safe in mice, the next step will require clinical trials to determine whether the compound will prove safe and effective in humans.

“Alzheimer’s disease research has traditionally focused on a single target, the amyloid pathway,” says Schubert, “but unfortunately drugs that have been developed through this pathway have not been successful in clinical trials. Our approach is based on the pathologies associated with old age — the greatest risk factor for Alzheimer’s and other neurodegenerative diseases-rather than only the specificities of the disease.”

To test the efficacy of J147 in a much more rigorous preclinical Alzheimer’s model, the Salk team treated mice using a therapeutic strategy that they say more accurately reflects the human symptomatic stage of Alzheimer’s. Administered in the food of 20-month-old genetically engineered mice, at a stage when Alzheimer’s pathology is advanced, J147 rescued severe memory loss, reduced soluble levels of amyloid, and increased neurotrophic factors essential for memory, after only three months of treatment.

In a different experiment, the scientists tested J147 directly against Aricept, the most widely prescribed Alzheimer’s drug, and found that J147 performed as well or better in several memory tests.

“In addition to yielding an exceptionally promising therapeutic, both the strategy of using mice with existing disease and the drug discovery process based upon aging are what make the study interesting and exciting,” says Schubert, “because it more closely resembles what happens in humans, who have advanced pathology when diagnosis occurs and treatment begins.” Most studies test drugs before pathology is present, which is preventive rather than therapeutic and may be the reason drugs don’t transfer from animal studies to humans.

Prior and her colleagues say that several cellular processes known to be associated with Alzheimer’s pathology are affected by J147, including an increase in a protein called brain-derived neurotrophic factor (BDNF), which protects neurons from toxic insults, helps new neurons grow and connect with other brain cells, and is involved in memory formation. Postmortem studies show lower than normal levels of BDNF in the brains of people with Alzheimer’s.

Because of its broad ability to protect nerve cells, the researchers believe that J147 may also be effective for treating other neurological disorders, such as Parkinson’s disease, Huntington’s disease and amyotrophic lateral sclerosis (ALS), as well as stroke, although their study did not directly explore the drug’s efficacy as a therapy for those diseases.

The Salk researchers say that J147, with its memory enhancing and neuroprotective properties, along with its safety and availability as an oral medication, would make an “ideal candidate” for Alzheimer’s disease clinical trials. They are currently seeking funding for such a trial.

The work was supported by the Alzheimer’s Drug Discovery Foundation, the Bundy Foundation, the Fritz Burns Foundation, the George E. Hewitt Foundation, the Alzheimer’s Association, and the National Institutes of Health.

It would be interesting to know which plants they used that were effective, so patients could experiment on themselves if they so chose to. The cited Alzheimer’s Research & Therapy paper mentions withania somnifera (its roots are used in ayurvedic medicine to prepare the herbal remedy ashwagandha, which has been traditionally used to treat various symptoms and conditions) and Gypenoside LXXIV (G-74), a major constituent of gynostemma pentaphyllum, used in Chinese medicine as an herbal medicine reputed to have powerful antioxidant and adaptogenic effects purported to increase longevity. Obligatory disclaimer: KurzweilAI does not advocate self-experimentation without medical supervision. — Editor

Credit: National Cancer Institute/Wikimedia Commons)

The frontal lobes in humans vs. other species are not — as previously thought — disproportionately enlarged relative to other areas of the brain, according to a study by Durham and Reading universities.

It concludes that the size of our frontal lobes — an area in the brain of mammals located at the front of each cerebral hemisphere — cannot solely account for humans’ superior cognitive abilities.

The study also suggest that supposedly more “primitive” areas, such as the cerebellum, were equally important in the expansion of the human brain. These areas may therefore play unexpectedly important roles in human cognition and its disorders, such as autism and dyslexia, say the researchers.

The scientists argue that many of our high-level abilities are carried out by more extensive brain networks linking many different areas of the brain. They suggest it may be the structure of these extended networks more than the size of any isolated brain region that is critical for cognitive functioning.

The Durham and Reading researchers, funded by The Leverhulme Trust, analyzed data sets from previous animal and human studies using phylogenetic (“evolutionary family tree”) methods, and found consistent results across all their data. They used a new method to look at the speed with which evolutionary change occurred, concluding that the frontal lobes did not evolve especially fast along the human lineage after it split from the chimpanzee lineage.

Kava (Piper methysticum) (credit: Forest & Kim Starr/Wikimedia Commons)

A world-first completed clinical study by an Australian team has found Kava, a medicinal South Pacific plant, significantly reduced the symptoms of people suffering anxiety.

The study, led by the University of Melbourne, revealed Kava could be an alternative to pharmaceutical products for the hundreds of thousands of Australians who suffer from generalized anxiety disorders (GAD)

“In this study we’ve been able to show that Kava offers a potential natural alternative for the treatment of chronic clinical anxiety; unlike some other options, it has less risk of dependency and less potential for side effects,” said lead researcher, Dr Jerome Sarris from Department of Psychiatry at the University of Melbourne.

The study also found that people’s genetic differences (polymorphisms) of certain neurobiological mechanisms called GABA transporters may modify their response to Kava.

“If this finding is replicated, it may pave the way for simple genetic tests to determine which people may be likely to have a beneficial anxiety-reducing effect from taking Kava,” Sarris said.

‘I’ll have what she’s having’

An additional novel finding of the study, recently published in Phytotherapy Research, was that Kava increased women’s sex drive compared to those in the placebo group, believed to be due to the reduction of anxiety, rather than any aphrodisiac effect.

Future studies confirming the genetic relationship to therapeutic response, and any libido-improving effects from Kava is now required. Dr Sarris said these significant findings are of importance to sufferers of anxiety and to the South Pacific region, which relies on Kava as a major export.

The study was funded by the NHMRC and Integria Healthcare who manufacture MediHerb and Thompson’s Kava products.

“Although scientific studies provide some evidence that kava may be beneficial for the management of anxiety, the U.S. Food and Drug Administration (FDA) has issued a warning that using kava supplements has been linked to a risk of severe liver damage.” — NIH National Center for Complementary and Alternative Medicine,

“Heavy use of kava with comorbid alcohol consumption or an existing liver condition appears to lead to malnutrition, weight loss, liver damage (causing elevated serum γ -glutamyltransferase and high-density lipoproteincholesterol levels), renal dysfunction, rashes, pulmonary hypertension, macrocytosis of red cells, lymphocytopenia, and decreasing platelet volumes. —  Fu PP, Xia Q, Guo L, Yu H, Chan PC (2008). “Toxicity of kava kava”. J Environ Sci Health C Environ Carcinog Ecotoxicol Rev 26 (1): 89–112 [98]. doi:10.1080/10590500801907407.PMID 18322868.

See https://en.wikipedia.org/wiki/Kava for more.

— Editor

UPDATE 5/15: Dangers of Kava cited in editorial statement.

(Credit: iStockphoto)

Researchers at BGI (formerly the Beijing Genomics Institute) in Shenzhen, China, the largest gene-sequencing facility in the world, are searching for the quirks of DNA that may contribute to genius in an ethically controversial study.

They are scouring the genomes of 1,600 U.S. adolescents who signed up for the Study of Mathematically Precocious Youth (SMPY) in the 1970s, Nature News reports.

Some geneticists say that the study is highly unlikely to find anything of interest because the sample size is too small and intelligence is too complex.

But scientists from BGI’s Cognitive Genomics group hope that their super-smart sample will give them an edge, because they  are  also using DNA samples from the SMPY recruits, plus samples from more than 500 people BGI recruited — albeit less selectively.

Tiny, intelligent things all around us, coordinating their activities. There are few more appropriate guides to this impending future than Alex Hawkinson, whose DC-based startup, SmartThings, has built what’s arguably the most advanced hub to tie connected objects together, Wired reports.

At his house, more than 200 objects, from the garage door to the coffeemaker to his daughter’s trampoline, are all connected to his SmartThings system. His office can automatically text his wife when he leaves and tell his home A/C system to start powering up.

In this future, the intelligence once locked in our devices now flows into the universe of physical objects, Technologists have struggled to name this emerging phenomenon. Some have called it the Internet of Things or the Internet of Everything or the Industrial Internet—despite the fact that most of these devices aren’t actually on the Internet directly but instead communicate through simple wireless protocols. Other observers, paying homage to the stripped-down tech embedded in so many smart devices, are calling it the Sensor Revolution.

But here’s a better way to think about what we’re building: It’s the Programmable World. [...]

(more)

Organic Photovoltaics: Plasmonic Enhanced Organic Photovoltaics, cover of Advanced Materials, May 2013

Qiaoqiang Gan, University at Buffalo assistant professor of electrical engineering, is developing a new generation of photovoltaic cells that produce more power and cost less to manufacture than what’s available today.

One of his more promising efforts involves the use of plasmonic-enhanced organic photovoltaic materials. These devices don’t match traditional solar cells in terms of energy production but they are less expensive and — because they are made (or processed) in liquid form — can be applied to a greater variety of surfaces.

Currently, solar power is produced with either thick polycrystalline silicon wafers or thin-film solar cells made up of inorganic materials such as amorphous silicon or cadmium telluride. Both are expensive to manufacture, Gan said.

His research involves thin-film solar cells, too, but unlike what’s on the market, he’s using organic photovoltaic materials such as polymers and small molecules that are carbon-based and less expensive.

“Compared with their inorganic counterparts, organic photovoltaics can be fabricated over large areas on rigid or flexible substrates,” Gan said, and applied to surfaces as easily as paint is on walls.

There are drawbacks to organic photovoltaic cells. They have to be thin due to their relatively poor electronic conductive properties, so without sufficient material to absorb light, it limits their optical absorption and lowers power conversion efficiency.

Their power conversion efficiency needs to be 10 percent or more to compete in the market, Gan said.

To achieve that benchmark, Gan and other researchers are incorporating metal nanoparticles and/or patterned plasmonic nanostructures into organic photovoltaic cells.

Recent material studies suggest they are succeeding, he said. Gan and his co-authors argue that, because of these breakthroughs, there should be a renewed focus on how nanomaterials and plasmonic strategies can create more efficient and affordable thin-film organic solar cells.

Yaroslav Urzhumov and the 3D-printed invisibility cloak (credit: Duke University)

Seven years ago, Duke University engineers demonstrated the first working invisibility cloak in complex laboratory experiments. Now it appears creating a simple cloak has become a lot simpler, by using a 3D printer..

Yaroslav Urzhumov, assistant research professor in electrical and computer engineering at Duke’s Pratt School of Engineering, said producing a cloak in this fashion is inexpensive and easy.

He and his team made a small one at Duke that looks like a Frisbee disc made out of Swiss cheese.

Algorithms determined the location, size and shape of the holes to deflect microwave beams. The fabrication process takes from three to seven hours.

Just like the 2006 cloak, the newer version deflects microwave beams, but researchers feel confident that in the not-so-distant future, the cloak can work for higher wavelengths, including visible light.

“We believe this approach is a way towards optical cloaking, including visible and infrared,” Urzhumov said. “And nanotechnology is available to make these cloaks from transparent polymers or glass. The properties of transparent polymers and glasses are not that different from what we have in our polymer at microwave frequencies.”

The disk-like cloak has an open area in its center where the researchers placed an opaque object. When microwave beams were aimed at the object through the side of the disk, the cloak made it appear that the object was not there.

Field intensity for an uncloaked cylinder (c) compared to a cloaked cylinder (d) (simulations) (credit: Yaroslav Urzhumov et al./Optics Letters)

“The design of the cloak eliminates the ‘shadow’ that would be cast, and suppresses the scattering from the object that would be expected,” said Urzhumov. “In effect, the bright, highly reflective object, like a metal cylinder, is made invisible. The microwaves are carefully guided by a thin dielectric shell and then re-radiated back into free space on the shadow side of the cloak.”

Urzhumov said that theoretically, the technique can be used to create much larger devices.

“Computer simulations make me believe that it is possible to create a similar polymer-based cloaking layer as thin as one inch wrapped around a massive object several meters in diameter,” he said. “I have run some simulations that seem to confirm this point.”

The  research was supported by the U.S. Army Research Office through a Multidisciplinary University Research Initiative grant.

AP’s president and chief executive officer, Gary Pruitt, described it as “serious interference with AP’s constitutional rights to gather and report the news.”.

UPDATE 5/14/2013: slanted wording removed.

Immunostained image of engrafted islet in hydrogel in diabetic mouse. (Red areas are insulin-producing cells. Green areas are blood vessels, and blue areas are DNA nuclei in cells.) (Credit: Georgia Tech)

Georgia Tech engineers and Emory University clinicians have successfully transplanted insulin-producing cells into a diabetic mouse model, reversing diabetic symptoms in the animal in as little as 10 days.

It could help lead to a possible cure for Type 1 diabetes.

The research team engineered a biomaterial to protect the cluster of insulin-producing cells — donor pancreatic islets — during injection. To foster blood vessel formation, the material also contains proteins  that allow the cells to successfully graft, survive and function within the body.

The hydrogel material is compatible with biological tissues that is a promising therapeutic delivery vehicle. This water-swollen, cross-linked polymer surrounds the insulin-producing cells and protects them during injection.

The hydrogel containing the islets was delivered to a new injection site on the outside of the small intestine, thus avoiding direct injection into the blood stream.

Once in the body, the hydrogel degrades in a controlled fashion to release a growth factor protein that promotes blood vessel formation and connection of the transplanted islets to these new vessels. In the study, the blood vessels effectively grew into the biomaterial and successfully connected to the insulin-producing cells.

Four weeks after the transplantation, diabetic mice treated with the hydrogel had normal glucose levels, and the delivered islets were alive and vascularized to the same extent as islets in a healthy mouse pancreas. The technique also required fewer islets than previous transplantation attempts, which may allow doctors to treat more patients with limited donor samples. Currently, donor cells from two to three cadavers are needed for one patient.

While the new biomaterial and injection technique is promising, the study used genetically identical mice and therefore did not address immune rejection issues common to human applications. The research team has funding from JDRF to study whether an immune barrier they created will allow the cells to be accepted in genetically different mice models. If successful, the trials could move to larger animals.

“We broke up our strategy into two steps,” said Garcia, a member of Georgia Tech’s Petit Institute for Bioengineering and Bioscience. “We have shown that when delivered in the material we engineered, the islets will survive and graft. Now we must address immune acceptance issues.”

Type 1 diabetes is a chronic disease that occurs when the pancreas produces little or no insulin, a hormone that allows the transport of sugar and other nutrients into tissues where they are converted to energy needed for daily life.

Most people with Type 1 diabetes currently manage their blood glucose levels with multiple daily insulin injections or by using an insulin pump. But insulin therapy has limitations. It requires careful measurement of blood glucose levels, accurate dosage calculations and regular compliance to be effective.

This work was also funded by the Regenerative Engineering and Medicine Center at Georgia Tech and Emory, and the Atlanta Clinical and Translation Science Institute from the Clinical and Translational Science Award Program.

The Center for Pediatric Healthcare Technology Innovation at Georgia Tech, the Department of Veterans Affairs Merit Review Program and the National Institutes of Health’s National Institute of Diabetes and Digestive and Kidney Diseases helped fund the project as well.

Yum, crunchy! Insects food stall in Bangkok, Thailand. (Credit: Takoradee/Wikimedia Commons)

The report by the UN Food and Agriculture Organization says that eating insects could help boost nutrition and reduce pollution, BBC News reports.

It notes than over 2 billion people worldwide already supplement their diet with insects.

Wasps, beetles and other insects are currently “underutilized” as food for people and livestock, the report says.

The authors point out that insects are nutritious, with high protein, fat and mineral content.

Insects are also “extremely efficient” in converting feed into edible meat. Crickets, for example, need 12 times less feed than cattle to produce the same amount of protein, according to the report. And they produce fewer environmentally harmful greenhouse gases than other livestock.

Insects are regularly eaten as a delicacy by many of the world’s population.

The report suggests that the food industry could help in “raising the status of insects” by including them in new recipes and adding them to restaurant menus.

Would you like

A “microrobot” to measure the eye’s oxygen supply (credit: Ergeneman O. et al./IEEE Transactions on Biomedical Engineering)

Researchers of the robotics lab at ETH Zurich have developed what ETH calls a “microrobot” (actually, a coated magnetic particle with no onboard  intelligence) that can be used to measure the retina’s oxygen supply.

An insufficient supply of oxygen can cause blindness. Glaucoma is only one of several diseases that can decrease the oxygen supply to the retina, sometimes within mere hours.

To make a fast and correct diagnosis, physicians need to be able to assess oxygen levels within the eye. But currently available tools are not very sensitive.

Measuring just 1 mm in length and 1/3 mm in diameter, the microparticle could be guided through the vitreous (fluid) material of the eye by external magnetic fields. A fluorescent dye on its surface emits fluorescence that fades gradually. The more oxygen is present, the faster it fades.

Setup for detecting oxygen (credit: Ergeneman O. et al./IEEE Transactions on Biomedical Engineering)

In theory, ophthalmologists could inject the microparticle with a syringe, steer it into the correct position using magnetic fields, and microscopically measure the fluorescence through the pupil. It could be easily removed the same way is was.introduced.

The disadvantage of the method is that it is slightly invasive, so it entails a risk of infection. Other tools newly on the market are non-invasive, but less sensitive in measuring oxygen. A combination of such tools might work, the researchers suggest.

Hand-held device for extracting DNA (credit: UW/NanoFacture/KNR)

University of Washington engineers and NanoFacture, a Bellevue, Wash., company, have created a device that can extract human DNA from fluid samples in a simpler, more efficient and environmentally friendly way than conventional methods.

The device will give hospitals and research labs a much easier way to separate DNA from human fluid samples, which will help with genome sequencing, disease diagnosis and forensic investigations.

Separating DNA from bodily fluids is a cumbersome process that’s become a bottleneck as scientists make advances in genome sequencing, particularly for disease prevention and treatment. The market for DNA preparation alone is about $3 billion each year.

Conventional methods use a centrifuge to spin and separate DNA molecules or strain them from a fluid sample with a micro-filter, but these processes take 20 to 30 minutes to complete and can require excessive toxic chemicals.

A close-up view of the portable device (credit: UW/NanoFacture/KNR)

UW engineers designed microscopic probes that dip into a fluid sample – saliva, sputum or blood – and apply an electric field within the liquid. That draws particles to concentrate around the surface of the tiny probe. Larger particles hit the tip and swerve away, but DNA-sized molecules stick to the probe and are trapped on the surface. It takes two or three minutes to separate and purify DNA using this technology.

“This simple process removes all the steps of conventional methods,” said Jae-Hyun Chung, a UW associate professor of mechanical engineering who led the research.

The hand-held device can clean four separate human fluid samples at once, but the technology can be scaled up to prepare 96 samples at a time, which is standard for large-scale handling.

The tiny probes, called microtips and nanotips, were designed and built at the UW in a micro-fabrication facility where a technician can make up to 1 million tips in a year, which is key in proving that large-scale production is feasible, Chung said.

Engineers in Chung’s lab also have designed a pencil-sized device using the same probe technology that could be sent home with patients or distributed to those serving in the military overseas. Patients could swab their cheeks, collect a saliva sample, then process their DNA on the spot to send back to hospitals and labs for analysis.

This could be useful as efforts ramp up toward sequencing each person’s genome for disease prevention and treatment, Chung said.

The market for this device isn’t developed yet, but Chung’s team will be ready when it is. Meanwhile, the larger device is ready for commercialization, and its creators have started working with distributors.

A UW Center for Commercialization grant of $50,000 seeded initial research in 2008, and since then researchers have received about $2 million in funding from the National Science Foundation and the National Institutes of Health.

Neurons created in the hippocampal dentate gyrus for control group (left) and for enriched-environment group (right), which showed increased explorative behavior and individuality (credit: CRTD/DZNE/Freund)

How do people and other organisms evolve into individuals that are distinguished from others by their own personal brain structure and behavior?

Why do identical twins not resemble each other perfectly even when they grew up together?

To shed light on these questions, the scientists observed 40 genetically identical mice that were kept in an enclosure that offered a rich shared environment with a large variety of activity and exploration options.

They showed that individual experiences influence the development of new neurons in mice, leading to measurable changes in the brain.

“The animals were not only genetically identical, they were also living in the same environment,” explained principal investigator Gerd Kempermann, Professor for Genomics of Regeneration, CRTD, and Site Speaker of the DZNE in Dresden. “However, this environment was so rich that each mouse gathered its own individual experiences in it. Over time, the animals therefore increasingly differed in their realm of experience and behavior.”

New neurons for individualized brains

Enrichment enclosure housing (credit: CRTD/DZNE/Freund)

Each of the mice was equipped with a special microchip emitting electromagnetic signals. This allowed the scientists to construct the mice movement profiles and quantify their exploratory behavior.

The result: despite a common environment and identical genes, the mice showed highly individualized behavioral patterns. In the course of the three-month experiment, these differences increased in size.

“These differences were associated with differences in the generation of new neurons in the hippocampus, a region of the brain that supports learning and memory,” said Kempermann “Animals that explored the environment to a greater degree also grew more new neurons than animals that were more passive.”

Adult neurogenesis [generation of new neurons] in the hippocampus allows the brain to react to new information flexibly. With this study, the authors show for the first time that personal experiences and ensuing behavior contribute to the “individualization of the brain.” The individualization they observed cannot be reduced to differences in environment or genetic makeup.

“Adult neurogenesis also occurs in the hippocampus of humans,” said Kempermann. “Hence we assume that we have tracked down a neurobiological foundation for individuality that also applies to humans.”

Implications

“The finding that behavior and experience contribute to differences between individuals has implications for debates in psychology, education, biology, and medicine,” said Ulman Lindenberger, Director of the Center for Lifespan Psychology at the Max Planck Institute for Human Development (MPIB) in Berlin.

“Our findings show that development itself contributes to differences in adult behavior. This is what many have assumed, but now there is direct neurobiological evidence in support of this claim. Our results suggest that experience influences the aging of the human mind.”

In the study, a control group of animals housed in a relatively unattractive enclosure was also examined; on average, neurogenesis in these animals was lower than in the experimental mice. “When viewed from educational and psychological perspectives, the results of our experiment suggest that an enriched environment fosters the development of individuality,” said Lindenberger.

Chinese cloud services provider 3Tcloud is deploying the country’s biggest education cloud project to optimize resource allocation and cut maintenance cost, ZDNET reports.

Samsung Electronics Co. said Sunday that it has successfully developed fifth-generation network (5G) core technology for the first time, allowing users to access faster data services expected to be available by 2020, Yonhap News Agency reports.

Under the new platform, users will be able to download and upload data at speeds of up to tens of gigabits per second (Gbps), compared to 75 megabits per second (Mbps) posted by the fourth-generation long-term evolution (LTE) service.

The mining speed of the bitcoin network on bitcoinwatch.com passed 1 exaFLOPS (1,000 petaFLOPS) this week — more than 8 times the combined speed of the Top 500 supercomputers, The Genesis Block reports.

(FLOPS stands for FLoating-point Operations Per Second, and is frequently used as a standard to measure computer speed. Bitcoin mining uses an integer calculation and almost no floating-point operations, so converting bitcoin network speed to this standard is somewhat clumsy.)

The FLOPS estimate is based on the opportunity cost of computers using their hardware for mining instead of other applications.  Miners are using their graphics cards to perform hashes instead of other FLOPS-based distributed computing. Therefore, a conversion rate of 1 hash = 12.7K FLOP is used to estimate what this hardware could be doing.

The combined speed of the Top 500 supercomputers is 48 petaFLOPS, roughly equivalent to 5% of the bitcoin network.

Note: the estimate was created in 2011, so the speed data for supercomputers may be low. We are checking the numbers. — Editor

A quadriplegic patient brings a chocolate bar to her mouth, using a robot arm she is guiding with her thoughts (via the implant in her head). But what if the robot had sensors so she could also control its grip? (Credit: UPMC)

Scientists have made tremendous advances toward building lifelike prosthetic limbs that move and function like the real thing.

But what’s missing is a sense of touch, so a patient knows how hard he or she is actually squeezing something, or exactly where the object is positioned relative to his or her hand.

“If you lose your somatosensory [body senses] system, it almost looks like your motor system is impaired,” he said.

“If you really want to create an arm that can actually be used dexterously without the enormous amount of concentration it takes without sensory feedback, you need to restore the somatosensory feedback.”

This is the related to a similar problem with robots (see “Related” below), where researchers have built better sensors into their the robots’ limbs and hands, along with better processing systems and control systems.

How to make a monkey believe a robotic hand is its own

Somatosensory prosthesis. (1) Mechanical device presses against the modular prosthetic limb (MPL). Its sensor (2) sends digitized force and vibration data to a (3) computer console, which computes the necessary corresponding stimulation level and programs pulses to (4) a neurostimulator, which (like a Parkinson’s neurostimulator) delivers electrical stimuli to (5) an electrode array (UEA) in the monkey’s brain, causing it to perceive the pressure applied to the prosthetic limb (credit: J.A. Berg et al./IEEE Transactions on Neural Systems and Rehabilitation Engineering)

So a team of University of Chicago neurobiologists, headed by Sliman Bensmaia, assistant professor of organismal biology and anatomy, came up with an idea: why not try the same thing, starting with a monkey?

To restore the somatosensory feedback, they equipped a robotic hand with pressure sensors.

These send electrical signals for processing, and from there to electrodes implanted in the brain to recreate the same response to touch as a real hand.

The researchers used rhesus macaques that were trained to respond to stimulation of the hand.

Their hands were hidden so they wouldn’t see that they weren’t actually being touched, and were given electrical pulses to simulate the sensation of touch.

The animals had electrodes implanted into the area of the brain that responds to touch to check the animals’ responses to each type of stimulus.

By combining the poking and brain-response data, the researchers were able to create a mathematical function that described the level of electrical pulses in the brain corresponding to different levels of physical pokes of the hand.

Top: Photograph of the fully integrated finger of a highly dexterous prosthetic hand (Modular Prosthetic Limb, MPL). Middle: Photograph of the MPL’s fingertip sensor node (FTSN). Bottom: Block diagram of FTSN. (Credit: J. Berg et al./IEEE Transactions on Neural Systems and Rehabilitation Engineering)

Then,switched to a prosthetic hand that was wired to the brain implants. They touched the prosthetic hand with the physical probe, which in turn sent similar electrical signals to the brain.

Bensmaia said that the animals performed identically whether poked on their own hand or on the prosthetic one.

“This is the first time as far as I know where an animal or organism actually perceives a tactile stimulus through an artificial transducer,” Bensmaia said.

“It’s an engineering milestone. But from a neuroengineering standpoint, this validates this function. You can use this function to have an animal perform this very precise task, precisely identically.”

Human trials

The FDA is in the process of approving similar devices for human trials, and Bensmaia said he hopes such a system is implemented within the next year. Producing a lifelike sense of touch would go a long way toward improving the dexterity and performance of prosthetic hands (or robot hands, for quadriplegics).

He said it would also help bridge a mental divide for amputees or people who have lost the use of a limb. Until now, prosthetics and robotic arms feel more like tools than real replacements, because they don’t produce the expected touch sensations .

“If every time you see your robotic arm touching something, you get a sensation that is projected to it, I think it’s very possible that in fact, you will consider this new thing as being part of your body,” he said.

Game avatar with a backpack (credit: S. Shyam Sundar, Penn State)

If you create and modify your own virtual reality avatars, could what happens to these alter egos influence how you perceive virtual environments?

Penn State researchers found this question relevant to designing more realistic and immersive virtual reality exercises and games. They assigned random avatars to one group of participants, but allowed another group to customize their own avatars.

When placed in a virtual environment with three hills of different heights and angles of incline, participants who customized their avatars perceived those hills as higher and steeper than participants who were assigned avatars by the researchers.

Half of the participants had avatars with backpacks. Those who had customized their avatar overestimated the amount of calories it would take to hike up the hill if their custom avatar.

“You exert more of your agency through an avatar when you design it yourself,” said S. Shyam Sundar, Distinguished Professor of Communications and co-director of the Media Effects Research Laboratory, Penn State. “Your identity mixes in with the identity of that avatar and, as a result, your visual perception of the virtual environment is colored by the physical resources of your avatar.”

Sundar said people with disabilities may feel more empowered designing their own avatars to have physical aids to navigate a virtual environment. And soldiers may want to create their own avatars to better simulate their perceptions of actual conditions in virtual reality exercises.

“Because building avatar identity is critical, it’s important to let users customize it,” Sundar said. “You are your avatar when it is customized.”

Future research will look at whether altering more elements of the users’ avatar will lead to more extensive changes in how people perceive virtual environments.

The Korea Science and Engineering Foundation supported this work.

Using retina-tracking technology, images on the smartphone would seem to float above the screen like a hologram and appear three-dimensional at all angles, and users may be able to navigate through content using just their eyes, according to sources,

With smartphones, Amazon could collect new data on its users through maps, phone calls and app downloads, and offer them shopping recommendations. There is also the potential for new services like mobile payments.

Remnants of a similar supernova explosion in the constellation Cassiopeia, about 11,000 light-years away.  (Credit: NASA/JPL-Caltech/STScI/CXC/SAO)

Researchers at the Technical University of Munich have found a radioactive iron isotope in bacteria microfossils.that they trace back to a supernova in our cosmic neighborhood.

This is the first proven biological signature of a starburst on our earth. The age determination of the deep-drill core from the Pacific Ocean showed that the supernova explosion must have occurred about 2.2 million years ago, roughly around the time when the modern human developed.

Magnetotactic bacteria live within the sediments of the Earth’s oceans, close to the water-sediment interface. They make within their cells hundreds of tiny crystals of magnetite (Fe₃O₄), each approximately 80 nanometers in diameter.

The bacteria obtain the iron from atmospheric dust that enters the ocean. So nuclear astrophysicist Shawn Bishop from the Technische Universitaet Muenchen conjectured that Fe-60 should also reside within those magnetite crystals produced by magnetotactic bacteria that existed at the time of the supernova interaction with our planet. These bacterially produced crystals, when found in sediments long after their host bacteria have died, are called “magnetofossils.”

(Credit: Defense Distributed)

The U.S. State Department has demanded designs by Defense Distributed for a 3D-printed gun be taken offline because publishing them online may breach arms-control regulations, Forbes reports.

The order to remove the blueprints for the plastic gun comes after they were downloaded more than 100,000 times.

However, the files were actually being served by Mega, the New Zealand-based storage service created by ex-hacker entrepreneur Kim Dotcom, an outspoken U.S. government critic. It’s not clear whether the file will be taken off Mega’s servers,

The files have also been uploaded several times to the Pirate Bay filesharing site.

This image from the study shows changes in degree of connectivity in the feedback group. Increases are shown in red/yellow and decreases in blue/purple. Decreases in connectivity are seen in limbic areas, and increases are seen in prefrontal regions. (Credit: D Scheinost et al./Yale University)

People provided with a real-time readout of activity in specific regions of their brains can learn to control that activity and lessen their anxiety, say Yale researchers.

They used functional magnetic resonance imaging (fMRI), to display the activity of the orbitofrontal cortex (a brain region just above the eyes) to subjects while they lay in a brain scanner.

Through a process of trial and error, these subjects were gradually able to learn to control their brain activity. This led both to changes in brain connectivity and to increased control over anxiety. These changes were still present several days after the training.

Extreme anxiety associated with worries about dirt and germs is characteristic of many patients with obsessive-compulsive disorder (OCD). Hyperactivity in the orbitofrontal cortex is seen in many of these individuals.

fMRI-driven neurofeedback has been used before in a few contexts, but not for the treatment of anxiety, the researchers say. The findings raise the possibility that real-time fMRI feedback may provide a novel and effective form of treatment for OCD.

Most applications come from the U.S. (17324), followed by China (10241), United Kingdom (3581), Russia, Mexico, Brazil, Canada, Colombia, Argentina and India.

The most popular candidate (for site visitors) so far is Anders from Sweden, a science-fiction fan (“I’m single, nothing holding me back”), and the highest-rated by visitors are Rickard (also from Sweden) and Arteum (from Russia).

“With 78,000 applications in two weeks, this is turning out to be the most desired job in history, said Bas Lansdorp, Mars One Co-Founder and CEO. “These numbers put us right on track for our goal of half a million applicants.”

As part of the application every applicant is required to explain his/her motivation behind their decision go to Mars in a one-minute video. Many applicants are choosing to publish this video on the Mars One website.

“Applicants we have received come from a very wide range of personalities, professions and ages,” said Dr. Norbert Kraft, Mars One Chief Medical Officer. “This is significant because what we are looking for is not restricted to a particular background. From Round 1 we will take forward the most committed, creative, resilient and motivated applicants.”

Mars One will continue to receive online applications until August 31, 2013. From all the applicants in Round 1, regional reviewers will select around 50–100 candidates for Round 2 in each of the 300 geographic regions in the world that Mars One has identified.

After four rounds, ending in 2015; Mars One will employ 28–40 candidates, who will train for around 7 years. Finally an audience vote will elect one of groups in training to be the envoys of humanity to Mars.