Engineers collaborate on inexpensive DNA sequencing method

While sequencing the genome of an animal species for the first time is so common that it hardly makes news anymore, it is less well known that sequencing any single individual's DNA is an expensive affair, costing many thousands of dollars using today's technology. An individual's genome carries markers that can provide advance warning of the risk of disease, but you need a fast, reliable and economical way of sequencing each patient's genes to take full advantage of them. Equally important is the need to continually sequence an individual's DNA over his or her lifetime, because the genetic code can be modified by many factors.

Schematic of an artificial membrane, across which a voltage forces an ionized fluid through the nanopore. Nucleotides on a strand of DNA are first tagged with different-sized polymers, and then the strand is passed near the nanopore opening, where a polymerase cleaves the polymers and passes them one by one through the nanopore. As they pass, the pore produces a unique ionic current blockade signature due to the tag's distinct chemical structure, thereby determining DNA sequence.

Read more at: http://phys.org/news/2012-10-collaborate-inexpensive-dna-sequencing-method.html#jCp

Schematic of an artificial membrane, across which a voltage forces an ionized fluid through the nanopore. Nucleotides on a strand of DNA are first tagged with different-sized polymers, and then the strand is passed near the nanopore opening, where a polymerase cleaves the polymers and passes them one by one through the nanopore. As they pass, the pore produces a unique ionic current blockade signature due to the tag's distinct chemical structure, thereby determining DNA sequence.

Schematic of an artificial membrane, across which a voltage forces an ionized fluid through the nanopore. Nucleotides on a strand of DNA are first tagged with different-sized polymers, and then the strand is passed near the nanopore opening, where a polymerase cleaves the polymers and passes them one by one through the nanopore. As they pass, the pore produces a unique ionic current blockade signature due to the tag's distinct chemical structure, thereby determining DNA sequence.

Read more at: http://phys.org/news/2012-10-collaborate-inexpensive-dna-sequencing-method.html#jCp

The new method determines DNA sequences by attaching distinct molecular "tags" to each of the four chemical building blocks, or "bases," that comprise the genetic information in a strand of DNA—abbreviated as A, G, C and T. Each of these polymer tags can then be cut from the strand and passed, one by one, through a nanometer-size hole in a membrane. A steady stream of fluid and ions flows through this "nanopore," which is large enough to contain only one tag at a time. As the polymer tags are different sizes, the change in electrical current caused by altered fluid flow shows which of the four bases sits at each point on the DNA strand.

Nanopores and their interaction with polymer molecules have been a longtime research focus of NIST scientist John Kasianowicz. His group collaborated with a team led by Jingyue Ju, director of Columbia's Center for Genome Technology and Biomolecular Engineering, which came up with the idea for tagging DNA building blocks for single molecule sequencing by nanopore detection. The ability to discriminate between the polymer tags was demonstrated by Kasianowicz, his NIST colleague Joseph Robertson, and others. Columbia University has applied for patents for the commercialization of the technology.

Kasianowicz estimates that the technique could identify a DNA building block with extremely high accuracy at an error rate of less than one in 500 million, and the necessary equipment would be within the reach of any medical provider. "The heart of the sequencer would be an operational amplifier that would cost much less than $1,000 for a one-time purchase," he says, "and the cost of materials and software should be trivial."

Kasianowicz adds that a private company might create a large array of nanopores that can analyze a single individual's genome cut up into many short strands of DNA, each of which could be sequenced quickly. Such an array potentially could provide the low-cost sequencing needed for routine medical use.

From phys

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TDK sees hard drive breakthrough in areal density

Perpendicular magnetic recording was an idea that languished for many years, says a TDK technology backgrounder, because the complexity of high-density magnetic recording technology stymied commercial development. "This method demands highly sophisticated thin-film process technologies to form microscopic single poles between multiple thin layers. Beyond that, a number of complex issues arise when trying to miniaturize single poles," said TDK. "One particularly difficult problem is overcoming pole erasure, the deletion of magnetic data due to remanent magnetization at the tip of the pole." 

 The magnetic head for thermal assist recording. Credit: via Tech-on.

As magnetic head manufacturers, TDK says it is now drawing on nano-level thin-film multilayering and processing technologies that clear the technological hurdles one by one. TDK features a Tunneling Magneto-Resistance (TMR) head , which uses thermal assist recording and a near-light field. (Researchers from Hitachi describe thermally assisted recording as an extension to perpendicular magnetic recording. In thermally-assisted recording, says Hitachi, magnetic grains can be made smaller while still resisting thermal fluctuations at room temperature.) Consumers are to see these hard drives using thermal assisted magnetic heads in 2014. Before that, though, 

TDK will officially unveil its new hard-drive technology this week at CEATEC Japan 2012. At CEATEC, the company will also show a thermal assist recording method based on near-field light by using an actual HDD supporting the method. A significant side story belongs to Showa Denko, which, among other divisions, engages in hard disk media. Showa Denko also has a confident grasp of the disk drive market: "We expect that demand for hard disk drives (HDDs) will continue to grow by about 10 percent annually. " Hard disk drives for years have been a dominant device for storage of data. Greater capacities and lower prices have kept the hard drive from falling victim to SSD technology. Showa Denko believes HDDs still have nowhere to go but up because of notebook demand, cloud computing, and current requirements for high-capacity servers at data centers, expected to increase. To meet the demand, the company intends to "speedily commercialize the sixth-generation PMR (perpendicular magnetic recording) media, and develop the next-generation SWR (shingled-write recording) media."

From phys

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Superman-Strength Bacteria Produce 24-Karat Gold

"Microbial alchemy is what we're doing -- transforming gold from something that has no value into a solid, precious metal that's valuable," said Kazem Kashefi, assistant professor of microbiology and molecular genetics.

 A bioreactor uses a gold-loving bacteria to turn liquid gold into useable, 24-karat gold.

He and Adam Brown, associate professor of electronic art and intermedia, found the metal-tolerant bacteria Cupriavidus metallidurans can grow on massive concentrations of gold chloride -- or liquid gold, a toxic chemical compound found in nature.

In fact, the bacteria are at least 25 times stronger than previously reported among scientists, the researchers determined in their art installation, "The Great Work of the Metal Lover," which uses a combination of biotechnology, art and alchemy to turn liquid gold into 24-karat gold. The artwork contains a portable laboratory made of 24-karat gold-plated hardware, a glass bioreactor and the bacteria, a combination that produces gold in front of an audience.

Brown and Kashefi fed the bacteria unprecedented amounts of gold chloride, mimicking the process they believe happens in nature. In about a week, the bacteria transformed the toxins and produced a gold nugget.

"The Great Work of the Metal Lover" uses a living system as a vehicle for artistic exploration, Brown said.

In addition, the artwork consists of a series of images made with a scanning electron microscope. Using ancient gold illumination techniques, Brown applied 24-karat gold leaf to regions of the prints where a bacterial gold deposit had been identified so that each print contains some of the gold produced in the bioreactor.

"This is neo-alchemy. Every part, every detail of the project is a cross between modern microbiology and alchemy," Brown said. "Science tries to explain the phenomenological world. As an artist, I'm trying to create a phenomenon. Art has the ability to push scientific inquiry."

It would be cost prohibitive to reproduce their experiment on a larger scale, he said. But the researchers' success in creating gold raises questions about greed, economy and environmental impact, focusing on the ethics related to science and the engineering of nature.

"The Great Work of the Metal Lover" was selected for exhibition and received an honorable mention at the cyber art competition, Prix Ars Electronica, in Austria, where it's on display until Oct. 7. Prix Ars Electronica is one of the most important awards for creativity and pioneering spirit in the field of digital and hybrid media, Brown said.

"Art has the ability to probe and question the impact of science in the world, and 'The Great Work of the Metal Lover' speaks directly to the scientific preoccupation while trying to shape and bend biology to our will within the postbiological age," Brown said.

From sciencedaily

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Meet the Nimble-Fingered Interface of the Future

Microsoft's Kinect, a 3-D camera and software for gaming, has made a big impact since its launch in 2010. Eight million devices were sold in the product's first two months on the market as people clamored to play video games with their entire bodies in lieu of handheld controllers. But while Kinect is great for full-body gaming, it isn't useful as an interface for personal computing, in part because its algorithms can't quickly and accurately detect hand and finger movements. 

 Finger mouse: 3Gear uses depth-sensing cameras to track finger movements.

Now a San Francisco-based startup called 3Gear has developed a gesture interface that can track fast-moving fingers. Today the company will release an early version of its software to programmers. The setup requires two 3-D cameras positioned above the user to the right and left. 

The hope is that developers will create useful applications that will expand the reach of 3Gear's hand-tracking algorithms. Eventually, says Robert Wang, who cofounded the company, 3Gear's technology could be used by engineers to craft 3-D objects, by gamers who want precision play, by surgeons who need to manipulate 3-D data during operations, and by anyone who wants a computer to do her bidding with a wave of the finger.

One problem with gestural interfaces—as well as touch-screen desktop displays—is that they can be uncomfortable to use. They sometimes  lead to an ache dubbed "gorilla arm." As a result, Wang says, 3Gear focused on making its gesture interface practical and comfortable. 

"If I want to work at my desk and use gestures, I can't do that all day," he says. "It's not precise, and it's not ergonomic." 

The key, Wang says, is to use two 3-D cameras above the hands. They are currently rigged on a metal frame, but eventually could be clipped onto a monitor. A view from above means that hands can rest on a desk or stay on a keyboard. (While the 3Gear software development kit is free during its public beta, which lasts until November 30, developers must purchase their own hardware, including cameras and frame.)

"Other projects have replaced touch screens with sensors that sit on the desk and point up toward the screen, still requiring the user to reach forward, away from the keyboard," says Daniel Wigdor, professor of computer science at the University of Toronto and author of Brave NUI World, a book about touch and gesture interfaces. "This solution tries to address that."

3Gear isn't alone in its desire to tackle the finer points of gesture tracking. Earlier this year, Microsoft released an update that enabled people who develop Kinect for Windows software to track head position, eyebrow location, and the shape of a mouth. Additionally, Israeli startup Omek, Belgian startup SoftKinetic, and a startup from San Francisco called Leap Motion—which claims its small, single-camera system will track movements to a hundredth of a millimeter—are all jockeying for a position in the fledgling gesture-interface market. 

"Hand tracking is a hard, long-standing problem," says Patrick Baudisch, professor of computer science at the Hasso-Plattner Institute in Potsdam, Germany. He notes that there's a history of using cumbersome gloves or color markers on fingers to achieve this kind of tracking. An interface without these extras is "highly desirable," Baudisch says.

3Gear's system uses two depth cameras (the same type used with Kinect) that capture 30 frames per second. The position of a user's hands and fingers are matched to a database of 30,000 potential hand and finger configurations. The process of identifying and matching to the database—a well-known approach in the gesture-recognition field—occurs within 33 milliseconds, Wang says, so it feels like the computer can see and respond to even a millimeter finger movement almost instantly.

Even with the increasing interest in gesture recognition for hands and fingers, it may take time for non-gamers and non-engineers to widely adopt the technology. 

"In the desktop space and productivity scenario, it's a much more challenging sell," notes Johnny Lee, who previously worked at Microsoft on the Kinect team and now works at Google. "You have to compete with the mouse, keyboard, and touch screen in front of you." Still, Lee says, he is excited to see the sort of applications that will emerge as depth cameras drop in price, algorithms for 3-D sensing continue to improve, and more developers see gestures as a useful way to interact with machines. 

By Kate Greene  
From Technology Review

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Billionaire Investor Peter Thiel Backs New Venture Aimed at Producing 3-D Printed Meat

 Peter Thiel's New 3-D Printing Challenge: Meat FotoosVanRobin via Wikimedia

Billionaire Peter Thiel would like to introduce you to the other, other white meat. The investor’s philanthropic Thiel Foundation’s Breakout Labs is offering up a six-figure grant (between $250,00 and $350,000, though representatives wouldn’t say exactly) to a Missouri-based startup called Modern Meadow that is flipping 3-D bio-printing technology originally aimed at the regenerative medicine market into a means to produce 3-D printed meat.

We've seen stuff kind of like this before. The larger idea here is to use cultured cell media to create a meat substitute that will satisfy the natural human desire for animal protein minus the environmental (and ethical) impacts of industrial scale farming. And by using 3-D printing technology, Modern Meadow might even be able to make it look like the real thing, though we’re somewhat skeptical even the best-looking faux fillet is going to stand up to the real deal.

It’s also going to be expensive, though Thiel and Modern Meadow hope that by developing a mature technology that can scale they will be able to bring costs somewhat in line with average meat prices. They’ve got a ways to go. Last time we visited the butcher meat was selling in bulk and by the ounce. CNET reports that Modern Meadow’s short-term goal is to create a single small sliver of its meat substitute less than one inch long.

By Clay Dillow
From popsci

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First Direct Observations of Quantum Effects in an Optomechanical System

Scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley, using a unique optical trapping system that provides ensembles of ultracold atoms, have recorded the first direct observations of distinctly quantum optical effects -- amplification and squeezing -- in an optomechanical system. Their findings point the way toward low-power quantum optical devices and enhanced detection of gravitational waves among other possibilities.

 Berkeley Lab researchers directly observed quantum optical effects -- amplification and ponderomotive squeezing -- in an optomechanical system. Here the yellow/red regions show amplification, the blue regions show squeezing. On the left is the data, on the right is the theoretical prediction in the absence of noise.

"We've shown for the first time that the quantum fluctuations in a light field are responsible for driving the motions of objects much larger than an electron and could in principle drive the motion of really large objects," says Daniel Brooks, a scientist with Berkeley Lab's Materials Sciences Division and UC Berkeley's Physics Department.

Brooks, a member of Dan Stamper-Kurn's research group, is the corresponding author of a paper in the journal Nature describing this research. The paper is titled "Nonclassical light generated by quantum-noise-driven cavity optomechanics." Co-authors were Thierry Botter, Sydney Schreppler, Thomas Purdy, Nathan Brahms and Stamper-Kurn.

Light will build-up inside of an optical cavity at specific resonant frequencies, similar to how a held-down guitar string only vibrates to produce specific tones. Positioning a mechanical resonator inside the cavity changes the resonance frequency for light passing through, much as sliding one's fingers up and down a guitar string changes its vibrational tones. Meanwhile, as light passes through the optical cavity, it acts like a tiny tractor beam, pushing and pulling on the mechanical resonator.

If an optical cavity is of ultrahigh quality and the mechanical resonator element within is atomic-sized and chilled to nearly absolute zero, the resulting cavity optomechanical system can be used to detect even the slightest mechanical motion. Likewise, even the tiniest fluctuations in the light/vacuum can cause the atoms to wiggle. Changes to the light can provide control over that atomic motion. This not only opens the door to fundamental studies of quantum mechanics that could tell us more about the "classical" world we humans inhabit, but also to quantum information processing, ultrasensitive force sensors, and other technologies that might seem like science fiction today.

"There have been proposals to use optomechanical devices as transducers, for example coupling motion to both microwaves and optical frequency light, where one could convert photons from one frequency range to the other," Brooks says. "There have also been proposals for slowing or storing light in the mechanical degrees of freedom, the equivalent of electromagnetically induced transparency or EIT, where a photon is stored within the internal degrees of freedom."

Already cavity optomechanics has led to applications such as the cooling of objects to their motional ground state, and detections of force and motion on the attometer scale. However, in studying interactions between light and mechanical motion, it has been a major challenge to distinguish those effects that are distinctly quantum from those that are classical -- a distinction critical to the future exploitation of optomechanics.

Brooks, Stamper-Kurn and their colleagues were able to meet the challenge with their microfabricated atom-chip system which provides a magnetic trap for capturing a gas made up of thousands of ultracold atoms. This ensemble of ultracold atoms is then transferred into an optical cavity (Fabry-Pferot) where it is trapped in a one-dimensional optical lattice formed by near-infrared (850 nanometer wavelength) light that resonates with the cavity. A second beam of light is used for the pump/probe.

"Integrating trapped ensembles of ultracold atoms and high-finesse cavities with an atom chip allowed us to study and control the classical and quantum interactions between photons and the internal/external degrees of freedom of the atom ensemble," Brooks says. "In contrast to typical solid-state mechanical systems, our optically levitated ensemble of ultracold atoms is isolated from its environment, causing its motion to be driven predominantly by quantum radiation-pressure fluctuations."

The Berkeley research team first applied classical light modulation to a low-powered pump/probe beam (36 picoWatts) entering their optical cavity to demonstrate that their system behaves as a high-gain parametric optomechanical amplifier. They then extinguished the classical drive and mapped the response to the fluctuations of the vacuum. This enabled them to observe light being squeezed by its interaction with the vibrating ensemble and the atomic motion driven by the light's quantum fluctuations. Amplification and this squeezing interaction, which is called "ponderomotive force," have been long-sought goals of optomechanics research.

"Parametric amplification typically requires a lot of power in the optical pump but the small mass of our ensemble required very few photons to turn the interactions on/off," Brooks says. "The ponderomotive squeezing we saw, while narrow in frequency, was a natural consequence of having radiation-pressure shot noise dominate in our system."

Since squeezing light improves the sensitivity of gravitational wave detectors, the ponderomotive squeezing effects observed by Brooks, Stamper-Kern and their colleagues could play a role in future detectors. The idea behind gravitational wave detection is that a ripple in the local curvature of spacetime caused by a passing gravitational wave will modify the resonant frequency of an optical cavity which, in turn, will alter the cavity's optical signal.

"Currently, squeezing light over a wide range of frequencies is desirable as scientists search for the first detection of a gravitational wave," Brooks explains. "Ponderomotive squeezing, should be valuable later when specific signals want to be studied in detail by improving the signal-to-noise ratio in the specific frequency range of interest."

The results of this study differ significantly from standard linear model predictions. This suggests that a nonlinear optomechanical theory is required to account for the Berkeley team's observations that optomechanical interactions generate non-classical light. Stamper-Kern's research group is now considering further experiments involving two ensembles of ultracold atoms inside the optical cavity.

"The squeezing signal we observe is quite small when we detect the suppression of quantum fluctuations outside the cavity, yet the suppression of these fluctuations should be very large inside the cavity," Brooks says. "With a two ensemble configuration, one ensemble would be responsible for the optomechanical interaction to squeeze the radiation-pressure fluctuations and the second ensemble would be studied to measure the squeezing inside the cavity."

This research was funded by the Air Force Office of Scientific Research and the National Science Foundation.

From sciencedaily

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Augmented Reality, Wrapped Around Your Finger

Normally, we point at things to specify, or to emphasize, what we're talking about. But a project from several MIT researchers aims to make pointing a way to learn more about the world around you—with a special ring on your index finger and a smartphone in your pocket.

Point taken: The EyeRing captures an image and sends it to a smartphone for processing.

Called EyeRing, the finger-worn device allows you to point at an object, take a photo, and hear feedback about what it is you just focused on. The project is the brainchild of Pattie Maes, a professor in MIT's Media Lab who studies interfaces that let us interact with digital information in novel, intuitive ways. Initially conceived as a potential aid for the visually impaired, the EyeRing could also work as a navigation or translation aid, or help children learn to read, say the researchers involved. The group is interested in eventually turning it into a commercial product.

As smartphones become increasingly common, the use of augmented reality—the blending of digital content with the real world—has also risen, mainly in the form of apps that harness the phone's camera and sensors and use its screen as a window to a more data-rich world (see "Augmented Reality Is Finally Getting Real").

The EyeRing takes this a step further by offering aural feedback via a wearable device. And while it's still just a research project, some experts believe wearable electronics will eventually become common—an idea Google recently put in the spotlight by confirming it's working on glasses that can show the wearer maps, messages, and more (see "You Will Want Google Goggles").

The EyeRing, which is currently printed with plastic using a 3-D printer, includes a tiny camera, a processor, and Bluetooth connectivity. To use it, you double-click a little button on its side and speak a command to determine the ring's function (it can currently be set to identify currency, text, prices on price tags, and colors). Point at whatever you'd like more information about—a shirt on a store rack, for instance—and click the button to snap a photo. The picture is sent via Bluetooth to your smartphone, where an app uses computer-vision algorithms to process the image and then announce out loud what it sees ("green," for example, denoting the color of the shirt). The results are also shown on the smartphone's screen.

"Not having to get your phone out of your pocket or purse and open it is a big advantage, we think," Maes says.

So far, the researchers have gotten EyeRing working with a smartphone running Google's Android software and with a Mac computer, says Roy Shilkrot, a graduate student in the Fluid Interfaces Group within MIT's Media Lab who is working on the device with Maes. An iPhone app is also in the works. The group has performed tests of the EyeRing with visually impaired people.

Aapo Markkanen, an analyst with ABI Research, thinks finger-worn devices like the EyeRing could be useful, but he notes that any wearable device will face some of same issues that have hampered smartphones: limited processing power and battery life. And wearable technology faces the additional hurdle of needing to be comfortable enough for people to want to use it for extended periods of time. Markkanen expects it will be several years before this is the case.

Maes agrees that processing power and battery life are concerns, but thinks that in a few years, turning EyeRing into a commercial device will be "very doable."

Shilkrot believes it could eventually be sold for under $100—perhaps as cheaply as $50. Still, he says, it would take several more iterations of the project before it could be useful to people. "We want to keep working on this and make it better," he says. "Right now, we're in the stage where we're trying to prove it's a viable solution."

By Rachel Metz

From Technology Review

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First Heralded Single Photon Source Made from Silicon

The line between "interesting" and practical in advanced electronics and optics often comes down to making the new device compatible with existing technology. According to NIST scientist Kartik Srinivasan, the new 0.5 mm x 0.05 mm-sized heralded photon generator meshes with existing technology in three important ways: it operates at room temperature; it produces photons compatible with existing telecommunications systems (wavelengths of about 1550 nanometers); and it's in silicon, and so can be built using standard, scalable fabrication techniques.

This is an illustration of the process of photon pair generation, in which input pump photons spontaneously generate special pairs of new photons that emerge at precisely the same time, with one at a slightly lower frequency and the other a slightly higher frequency, after which heralding occurs.

A "heralded" photon is one of a pair whose existence is announced by the detection of its partner -- the "herald" photon. To get heralded single photons, the group built upon a technique previously demonstrated in silicon called photon pair generation.

In photon pair generation, a laser pumps photons into a material whose properties cause two incoming pump photons to spontaneously generate a new pair of frequency-shifted photons. However, while these new photons emerge at precisely the same time, it is impossible to know when that will occur.

"Detecting one of these photons, therefore, lets us know to look for its partner," says Srinivasan. "While there are a number of applications for photon pairs, heralded pairs will sometimes be needed, for example, to trigger the storage of information in future quantum-based computer memories."

According to Srinivasan, the group's silicon-based device efficiently produced pairs of single photons, and their experiment clearly demonstrated they could herald the presence of one photon by the detection of the other.

While the new device is a step forward, it is not yet practical, according to co-author Professor Shayan Mookherjea at UC San Diego, because a single source is not bright enough and a number of other required functions need to be integrated onto the chip. However, putting multiple sources along with their complementary components onto a single chip -- something made possible by using silicon-based technology -- could supply the performance needed for practical applications.

The work was among the three finalists and received an honorable mention in the Maiman Student Paper Competition.

From sciencedaily

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New fuel cell keeps going after the hydrogen runs out

 Shriram Ramanathan's laboratory setup for testing solid-oxide fuel cells. The fuel cell is hidden under the circular component at the top, which pins it down to create a tight seal with the hydrogen fuel entering from below. Two needles connect with the electrodes to measure the electricity produced.

Materials scientists at Harvard have demonstrated an equivalent feat in clean energy generation with a solid-oxide fuel cell (SOFC) that converts hydrogen into electricity but can also store electrochemical energy like a battery. This fuel cell can continue to produce power for a short time after its fuel has run out.

"This thin-film SOFC takes advantage of recent advances in low-temperature operation to incorporate a new and more versatile material," explains principal investigator Shriram Ramanathan, Associate Professor of Materials Science at the Harvard School of Engineering and Applied Sciences (SEAS). "Vanadium oxide (VOx) at the anode behaves as a multifunctional material, allowing the fuel cell to both generate and store energy."

The finding, which appears online in the journal Nano Letters, will be most important for small-scale, portable energy applications, where a very compact and lightweight power supply is essential and the fuel supply may be interrupted.

 Left: Each dark speck within the nine white circles at left is a tiny fuel cell. An AA battery is shown for size comparison. Right: One of the nine circles is magnified in this image, showing the wrinkled surface of the electrochemical membrane.

"Unmanned aerial vehicles, for instance, would really benefit from this," says lead author Quentin Van Overmeere, a postdoctoral fellow at SEAS. "When it's impossible to refuel in the field, an extra boost of stored energy could extend the device's lifespan significantly."

Ramanathan, Van Overmeere, and their coauthor Kian Kerman (a graduate student at SEAS) typically work on thin-film SOFCs that use platinum for the electrodes (the two "poles" known as the anode and the cathode). But when a platinum-anode SOFC runs out of fuel, it can continue to generate power for only about 15 seconds before the electrochemical reaction peters out.

 Three possible mechanisms (left to right) can explain the operation of the vanadium oxide / platinum fuel cell after its fuel has been spent. The illustration represents a simplified cross-section of the SOFC: the top layer is the cathode (made of porous platinum), the middle layer is the electrolyte (yttria-stabilized zirconia, YSZ), and the bottom layer is the VOx anode. During normal operation, the hydrogen fuel would be at the bottom of this diagram.

The new SOFC uses a bilayer of platinum and VOx for the anode, which allows the cell to continue operating without fuel for up to 14 times as long (3 minutes, 30 seconds, at a current density of 0.2 mA/cm2). This early result is only a "proof of concept," according to Ramanathan, and his team predicts that future improvements to the composition of the VOx-platinum anode will further extend the cell's lifespan.  

During normal operation, the amount of power produced by the new device is comparable to that produced by a platinum-anode SOFC. Meanwhile, the special nanostructured VOx layer sets up various chemical reactions that continue after the hydrogen fuel has run out.

"There are three reactions that potentially take place within the cell due to this vanadium oxide anode," says Ramanathan. "The first is the oxidation of vanadium ions, which we verified through XPS (X-ray photoelectron spectroscopy). The second is the storage of hydrogen within the VOx crystal lattice, which is gradually released and oxidized at the anode. And the third phenomenon we might see is that the concentration of oxygen ions differs from the anode to the cathode, so we may also have oxygen anions being oxidized, as in a concentration cell."

All three of those reactions are capable of feeding electrons into a circuit, but it is currently unclear exactly what allows the new fuel cell to keep running. Ramanathan's team has so far determined experimentally and quantitatively that at least two of three possible mechanisms are simultaneously at work.

Ramanathan and his colleagues estimate that a more advanced fuel cell of this type, capable of producing power without fuel for a longer period of time, will be available for applications testing (e.g., in micro-air vehicles) within 2 years.

From phys.org

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Google's futuristic glasses move closer to reality

The breakthrough is a wearable computer — a pair of Internet-connected glasses that Google Inc. began secretly building more than two years ago. The technology progressed far enough for Google to announce "Project Glass" in April. Now the futuristic experiment is moving closer to becoming a mass-market product.

Google announced Wednesday that it's selling a prototype of the glasses to U.S. computer programmers attending a three-day conference that ends Friday. Developers willing to pay $1,500 for a pair of the glasses will receive them early next year.

The company is counting on the programmers to suggest improvements and build applications that will make the glasses even more useful.

"This is new technology and we really want you to shape it," Google co-founder Sergey Brin told about 6,000 attendees. "We want to get it out into the hands of passionate people as soon as possible."

If all goes well, a less expensive version of the glasses is expected to go on sale for consumers in early 2014. Without estimating a price for the consumer version, Brin made it clear the glasses will cost more than smartphones.

"We do view this is as a premium sort of thing," Brin said during a question-and-answer session with reporters. 

 Google co-founder Sergey Brin talks on the phone as he wears Google's new Internet-connected glasses at the Google I/O conference in San Francisco, Wednesday, June 27, 2012. Google is making prototypes of the device, known as Project Glass, available to test. They can only be purchased — for $1,500 — at the conference this week, for delivery early next year.

 Brin acknowledged Google still needs to fix a variety of bugs in the glasses and figure out how to make the battery last longer so people can wear them all day.

Those challenges didn't deter Brin from providing conference attendees Wednesday with a tantalizing peek at how the glasses might change the way people interact with technology.

Google hired skydivers to jump out of a blimp hovering 7,000 feet (2,130 meters) above downtown San Francisco. They wore the Internet-connected glasses, which are equipped with a camera, to show how the product could unleash entirely new ways for people to share their most thrilling — or boring — moments. As the skydivers parachuted onto the roof of the building where the conference was held, the crowd inside was able to watch the descent through the skydivers' eyes as it happened.

"I think we are definitely pushing the limits," Brin told reporters after the demonstration. "That is our job: to push the edges of technology into the future." 

The glasses have become the focal point of Brin's work since he stepped away from Google's day-to-day operations early last year to join the engineers working on ambitious projects that might once have seemed like the stuff of science fiction. Besides the Internet-connected glasses, the so-called Google X lab has also developed a fleet of driverless cars that cruise roads. The engineers there also dream of building elevators that could transport people into space.

While wearing Google's glasses, directions to a destination or a text message from a friend can appear literally before your eyes. You can converse with friends in a video chat, take a photo without taking out a camera or phone or even buy a few things online as you walk around.

The glasses will likely be seen by many critics as the latest innovation that shortens attention spans and makes it more difficult for people to fully appreciate what's happening around them.

But Brin and the other engineers are hoping the glasses will make it easier for people to strike the proper balance between the virtual and physical worlds. If they realize their goal, it will seem odd in three or four years for people to be looking up and down on their phones when they could have all the digital tools they need in a pair of glasses

Isabelle Olsson, one of the engineers working on the project, said the glasses are meant to interact with people's senses, without blocking them. The display on the glasses' computer appears as a small rectangular on a rim above the right eye. During short test of the prototype glasses, a reporter for The Associated Press was able to watch a video of exploding fireworks on the tiny display screen while remaining engaged with the people around him.

The glasses seem likely to appeal to runners, bicyclists and other athletes who want to take pictures of their activities as they happen. Photos and video can be programmed to be taken at automatic intervals during any activity.

Brin said he became excited about the project when he tossed his son in the air and a picture taken by the glasses captured the joyful moment, just the way he saw it.

"That was amazing," Brin said. "There was no way I could have that memory without this device."

From phys.org

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Colorful creates passively cooled Nvidia graphics card

The GTX680 is Nvidia's powerful single-core graphics card. GeForce refers to a brand of graphics processing units (GPUs) designed by Nvidia. In March it was announced that the first chip based on the Kepler architecture was hitting the market, aboard a new graphics card called the GeForce GTX 680. 

The passively cooled GeForce GTX 680 model uses 20 heatpipes and two aluminum heatsinks. Colorful claims this is the first zero-noise GTX 680 solution.

Colorful is considered one of Nvidia's most important board partners in Asia. Established in 1995, Colorful conducts research, designs, manufactures, and sells consumer graphics cards. Those familiar with Colorful regard it as a company that frequently comes up with surprises. One such description is that Colorful is “an unorthodox producer of Nvidia cards,” according to PC reviews site, HEXUS. A Singapore-based technology site refers to Colorful as making “some of the most outrageous and over-the-top graphics cards you will find.”

Colorful‘s “cooled” solution has 20 heatpipes combined with 280 aluminum fins. In reviewing the announcement, a note of concern was struck over the fact that Colorful has not yet mentioned clock speeds. Geek.com wonders if they might have underclocked the GPU to help keep temperatures to a minimum. “If it hasn’t been underclocked, then it may be a card worth keeping an eye out for,” said the report. The techPowerup site said that the design guarantees reliable silent operation at reference clock speeds or mild overclocking.

There has been no price or release date announced; Colorful is said to be still assessing the marketability of the design.

When Colorful first showed off the iGame card at Computex 2012 in Taipei earlier this month, the product was described as “iGame GeForce GTX 680 Silent” and drew prompt attention as a card that relies completely on passive cooling, not a fan,.

This is not the first time, however, that a manufacturer has achieved a passively cooled graphics card, and more competition is likely to emerge sooner than later, under different partnerships. Sapphire announced in early June that it had come up with its new passively cooled Radeon HD 7770 card. Like the Colorful entry, this does not use a fan but instead dissipates heat via a “heatspreader.” Sapphire partners with AMD.

From phys.org

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The Jets of the Future

 Box Wing Jet Nick Kaloterakis 

NASA asked the world’s top aircraft engineers to solve the hardest problem in commercial aviation: how to fly cleaner, quieter and using less fuel. The prototypes they imagined may set a new standard for the next two decades of flight.
BOX WING JET, LOCKHEED MARTIN

Target Date: 2025
Passenger jets consume a lot of fuel. A Boeing 747 burns five gallons of it every nautical mile, and as the price of that fuel rises, so do fares. Lockheed Martin engineers developed their Box Wing concept to find new ways to reduce fuel burn without abandoning the basic shape of current aircraft. Adapting the lightweight materials found in the F-22 and F-35 fighter jets, they designed a looped-wing configuration that would increase the lift-to-drag ratio by 16 percent, making it possible to fly farther using less fuel while still fitting into airport gates.

They also ditched conventional turbofan engines in favor of two ultrahigh-bypass turbofan engines. Like all turbofans, they generate thrust by pulling air through a fan on the front of the engine and by burning a fuel-air mixture in the engine’s core. With fans 40 percent wider than those used now, the Box Wing’s engines bypass the core at several times the rate of current engines. At subsonic speeds, this arrangement improves efficiency by 22 percent. Add to that the fuel-saving boost of the box-wing configuration, and the plane is 50 percent more efficient than the average airliner. The additional wing lift also lets pilots make steeper descents over populated areas while running the engines at lower power. Those changes could reduce noise by 35 decibels and shorten approaches by up to 50 percent.—Andrew Rosenblum

Supersonic Green Machine:  Nick Kaloterakis

SUPERSONIC GREEN MACHINE, LOCKHEED MARTIN

Target Date: 2030
The first era of commercial supersonic transportation ended on November 26, 2003, with the final flight of the Concorde, a noisy, inefficient and highly polluting aircraft. But the dream of a sub-three-hour cross-country flight lingered, and in 2010, designers at Lockheed Martin presented the Mach 1.6 Supersonic Green Machine. The plane’s variable-cycle engines would improve efficiency by switching to conventional turbofan mode during takeoff and landing. Combustors built into the engine would reduce nitrogen oxide pollution by 75 percent. And the plane’s inverted-V tail and underwing engine placement would nearly eliminate the sonic booms that led to a ban on overland Concorde flights.

The configuration mitigates the waves of air pressure (caused by the collision with air of a plane traveling faster than Mach 1) that combine into the enormous shock waves that produce sonic booms. “The whole idea of low-boom design is to control the strength, position and interaction of shock waves,” says Peter Coen, the principal investigator for supersonic projects at NASA. Instead of generating a continuous loop of loud booms, the plane would issue a dull roar that, from the ground, would be about as loud as a vacuum cleaner.—Andrew Rosenblum

 Sugar Volt:  Nick Kaloterakis

SUGAR VOLT, BOEING

Target Date: 2035
The best way to conserve jet fuel is to turn off the gas engines. That’s only possible with an alternative power source, like the battery packs and electric motors in the Boeing SUGAR Volt’s hybrid propulsion system. The 737-size, 3,500-nautical-mile-range plane would draw energy from both jet fuel and batteries during takeoff, but once at cruising altitude, pilots could switch to all-electric mode [see Volta Volare GT4]. At the same time Boeing engineers were rethinking propulsion, they also rethought wing design. “By making the wing thinner and the span greater, you can produce more lift with less drag,” says Marty Bradley, Boeing’s principal investigator on the project. The oversize wings would fold up so pilots could access standard boarding gates. Together, the high-lift wings, the hybrid powertrain and the efficient open-rotor engines would make the SUGAR Volt 55 percent more efficient than the average airliner. The plane would emit 60 percent less carbon dioxide and 80 percent less nitrous oxide. Additionally, the extra boost the hybrid system provides at takeoff would enable pilots to use runways as short as 4,000 feet. (For most planes, landing requires less space than takeoff.) A 737 needs a minimum of 5,000 feet for takeoff, so the SUGAR Volt could bring cross-country flights to smaller airports.—Rose Pastore

By Andrew Rosenblum and Rose Pastore
From popsci

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Cell membrane is patterned like a patchwork quilt

The cell membrane must process numerous signals from the environment and the cell interior in order to initiate apposite molecular responses to changing conditions. For example, if certain messenger substances bind to the membrane, this can trigger the growth or division of a cell. The cell membrane has long been the focus of scientific research. One aspect that has remained largely unexplained, however, is exactly how its various components organise themselves. According to an early model, the fats (lipids) and proteins anchored in the membrane are in constant flux and do not form fixed structures. That at least some are organised in bounded domains was only proven quite recently, and only for a small number of proteins.

Researchers working with Roland Wedlich-Söldner, a group leader at the Max Planck Institute of Biochemistry, have now carried out the first comprehensive analysis of the molecular structure of the cell membrane. They used advanced imaging technologies for the purpose, enabling them to obtain much sharper images of the cell membrane and the marked proteins within them than were previously available. They discovered that domain formation in the cell membrane is not the exception, but the rule. Each protein in the cell membrane is located in distinct areas that adopt a patch- or network-like structure. The entire cell membrane thus consists of domains – like a kind of molecular patchwork quilt.

“Some areas contain more than one type of protein,” says Roland Wedlich-Söldner. “Even if these molecules fulfil entirely different functions, they generally have one thing in common: they are attached to a shared domain in the membrane by a similar or identical molecular anchor.” In another experiment, the scientists succeeded in demonstrating the extent to which the protein function depends on this specific environment: they replaced the original anchor in some proteins with another molecular variant. The modified proteins then relocated to a “foreign” domain that matched the new anchor. However, they were no able longer to function correctly in their new surroundings.

How then do proteins find the appropriate domain and remain associated with it, despite being relatively mobile in the plane of the membrane? The researchers were able to show that the lipids in the cell membrane play a central role in this process. Different lipids prefer to accumulate around certain protein anchors. Therefore, areas arise that are particularly attractive to proteins with a similar type of anchor. This could explain how cell membranes self-organise – another previously unanswered question in biology. The highly ordered structure of the cell membrane could help scientists to gain a better understanding of its many functions. “One may assume that many processes only function efficiently thanks to the formation of domains in the cell membrane,” says Wedlich-Söldner. “It is possible that the cell exploits a principle that also applies in everyday life: a certain degree of order makes it much easier to get things done.”

From phys.org

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First Light: Researchers Develop New Way to Generate Superluminal Pulses

According to Einstein's special theory of relativity, light traveling in a vacuum is the universal speed limit. No information can travel faster than light.

But there's kind of a loophole. A short burst of light arrives as a sort of (usually) symmetric curve like a bell curve in statistics. The leading edge of that curve can't exceed the speed of light, but the main hump, the peak of the pulse, can be skewed forward or backward, arriving sooner or later than it normally would.

In four-wave mixing, researchers send "seed" pulses of laser light into a heated cell containing atomic rubidium vapor along with a separate "pump" beam at a different frequency. The vapor amplifies the seed pulse and shifts its peak forward, making it superluminal. At the same time, photons from the inserted beams interact with the vapor to generate a second pulse called the "conjugate." Its peak, too, can travel faster or slower depending on how the laser is tuned and the conditions inside the gain medium.

Recent experiments have generated "uninformed" faster-than-light pulses by amplifying the leading edge of the pulse and attenuating, or cutting off, the back end. The method introduces a great deal of noise with no great increase in the apparent speed. Four-wave mixing produces cleaner, less noisy pulses with a greater increase in speed by "re-phasing" or rearranging the light waves that make up the pulse.

In four-wave mixing, researchers send 200-nanosecond-long "seed" pulses of laser light into a heated cell containing atomic rubidium vapor along with a separate "pump" beam at a different frequency from the seed pulses. The vapor amplifies the seed pulse and shifts its peak forward so that it becomes superluminal. At the same time, photons from the inserted beams interact with the vapor to generate a second pulse, called the "conjugate" because of its mathematical relationship to the seed. Its peak, too, can travel faster or slower depending on how the laser is tuned and the conditions inside the laser.

In the experiment, the pulses' peaks arrived 50 nanoseconds faster than light traveling through a vacuum.

One immediate application that the group would like to explore for this system is quantum discord. Quantum discord mathematically defines the quantum information shared between two correlated systems -- in this case, the seed and conjugate pulses. By performing measurements of quantum discord between fast beams and reference beams, the group hopes to determine how useful this fast light could be for the transmission and processing of quantum information.

From sciencedaily

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New App Watches Your Every Move

Once in a while, you might feel like you're being watched. Lately, I know I am, thanks to a smart-phone app that stealthily tracks my every move, no check-ins required, with greater accuracy than common geolocation tools.

I’ll be watching you: Placeme keeps track of all the places you visit each day, no check-ins required. The iPhone app is meant to showcase the capabilities of Alohar Mobile’s mobile platform.
 

Called Placeme, the free app takes advantage of the smart phone's sensors and its GPS and Wi-Fi capabilities to figure out where I go and for how long, and stores this data in a private log on my iPhone.

It may sound creepy or unnecessary, but as more people carry smart phones with them everywhere, demand for this kind of persistent location tracking may grow—not just from marketers, but also from individuals who want to keep an eye on their own movements or of loved ones with medical conditions such as Alzheimer's. At least, that's the hope of the startup behind Placeme, Alohar Mobile, which has also released a software development kit to help coders create apps that can log your movements accurately and efficiently—without running down the battery in your smart phone.

To use Placeme, available for the iPhone and phones running Google's Android software, you must keep both your GPS and Wi-Fi on. As you travel around, the app will silently log the places you visit. Within the app, you can view day-by-day maps of where you've been. Each destination you spent time at is marked by little pins; tap on a pin to see how long you were there and check out a Google Street View image of the location. You can also add notes about a location (a favorite dish at a restaurant, perhaps). There's also a searchable, alphabetical log of all your destinations. The app gathers data from your phone's various sensors and GPS and Wi-Fi, encrypts that data, sends it over a secure connection to Alohar's servers, and then calculates your location. To cut down on battery drain, locations are calculated remotely, and the app only takes GPS data samples at certain times (like when the accelerometer is active).

Alohar Mobile cofounders Alvin Lau and Sam Liang imagine a future in which apps can draw useful information from all this location data: for instance, automatically alerting emergency services if you're injured in a car crash and letting paramedics know precisely where you are. An app for Alzheimer's patients and their families could show where that person has gone in the last 24 hours.

Lau and Liang have demonstrated these types of apps at recent conferences, and they're hoping developers will come up with many more applications, ranging from health and fitness to shopping, using their platform. More than 250 developers have so far signed up to use their free software development kit since it was released several weeks ago.

Key to Alohar's platform is making location detection more precise than it normally is. Liang, formerly a platform architect for Google's location server platform, says that using GPS, Wi-Fi, and cell tower triangulation, as many apps and services including Google Maps do, can result in a wide margin of error—illustrated in Google Maps by the transparent blue ring that pulses around the blue dot marking your current location to indicate a degree of uncertainty.

Alohar says that location detection that incorporates data from the other sensors on a smart phone, such as the accelerometer and compass, can calculate your location more exactly. Though they haven't yet made this feature available to developers, Lau says, Alohar's platform can also determine if you're walking or driving.

David Petersen, CEO of Sense Networks, a company that mines location data for useful information about an area, thinks there's plenty of room for improvement in location data gathering. While GPS can accurately show where you are, it sucks up so much battery life that your phone is often not using it to pinpoint you, he says, and other methods are less reliable. He notes that greater accuracy could also mean better targeted ads. "I think these guys are working on a very valuable piece of the puzzle," he says.

Alohar has a ways to go, though. In dense urban areas, it seemed to have trouble determining exactly where I was, and it didn't mark every place I went. Fortunately, it can be trained. Once I taught it that I live down the street from a Pilates studio and not inside it, the app was able to correctly mark me as home whenever I was actually there. Which, according to Placeme, is more often than I'd like to admit.

By Rachel Metz
From Technology Review

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All-carbon-nanotube transistor can be crumpled like a piece of paper

The researchers, Shinya Aikawa and coauthors from the University of Tokyo and the Tokyo University of Science, have published their study in a recent issue of Applied Physics Letters.

“The most important thing is that electronics might now be usable in places or situations that were previously not possible,” coauthor Shigeo Maruyama, a mechanical engineering professor at the University of Tokyo, told PhysOrg.com. “Since our device is so flexible and deformable it could potentially be stuck anywhere. This could lead to active electronic devices that are applied like a sticker or an adhesive bandage, as well as to wearable electronics.”

Unlike other field-effect transistors (FETs), the new FET is unique in that all channels and electrodes are made of carbon nanotubes (CNTs), while the substrate is made of highly flexible and transparent poly(vinyl alcohol) (PVA). Previously, the majority of flexible, transparent FETs have used gold or indium tin oxide as electrodes. However, gold decreases the devices’ transparency while brittle indium tin oxide limits the flexibility. A few recent FETs have been made that consist entirely of CNTs, but so far these devices have been built on thick plastic substrates, limiting their flexibility.

 The present device (1 mm curvature) is the most bendable CNT-FET to date without performance degradation. Image credit: Aikawa, et al. ©2012 American Institute of Physics

After patterning the components using standard photolithography and laminating the device with the PVA, the final thickness of the new all-CNT-FET was approximately 15 µm. This thinness made the device highly pliable, with tests showing that the finished transistor could withstand a 1-mm bending radius with almost no changes in electrical properties. Although other transistors have been developed with bendable radii as low as 0.1 mm, the new transistor is the most bendable that experiences no performance degradation. 

After subjecting the transistor to 100 wrinkling cycles, the researchers observed a slight decrease in maximum drain current, which may be due to some broken connections in the CNT network. However, the minimal decrease in maximum drain current, which stabilizes after about 30 cycles, does not affect the overall transconductance, which was not affected by the repeated bending. 

In addition to its flexibility, the all-CNT-FET also has an optical transmittance of more than 80%, which is sufficient to clearly see through the device. The researchers attribute the high flexibility to the inherent robustness of carbon nanotubes, and predict that they could increase the flexibility even further by optimizing the positions of the channels. Overall, the results demonstrate that flexible, transparent all-carbon electronics are coming closer to commercial reality.

“Ongoing topics are to control device properties and to integrate them,” Maruyama said. “If these issues can be resolved, we would like to realize flexible and transparent all-carbon working circuits.”

 

From physorg

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Bacteria Communicate by Touch, New Research Suggests

The findings appeared recently in the journal Genes & Development.

Christopher Hayes, UCSB associate professor of molecular, cellular, and development biology, teamed with graduate students Elie Diner, Christina Beck, and Julia Webb to study uropathogenic E. coli (UPEC), which causes urinary tract infections in humans. They discovered a sibling-like link between cell systems that have largely been thought of as rivals.

 Associate professor Christopher Hayes and graduate student Christina Beck

The paper shows that bacteria expressing a contact--dependent growth inhibition system (CDI) can inhibit bacteria without such a system only if the target bacteria have CysK, a metabolic enzyme required for synthesis of the amino acid cysteine. CysK is shown to bind to the CDI toxin -- an enzyme that breaks RNA ó and activate it.

For a cell system typically thought of as existing only to kill other bacteria -- as CDIs have largely been -- the results are surprising, said Hayes, because they suggest that a CDI+ inhibitor cell has to get permission from its target in order to do the job.

"This is basically the inhibitor cell asking the target cell, 'Can I please inhibit you?'" he explained. "It makes no sense. Why add an extra layer of complexity? Why add a permissive factor? That's an unusual finding.

"We think now that the [CDI] system is not made solely because these cells want to go out and kill other cells," Hayes continued. "Our results suggest the possibility that these cells may use CDI to communicate as siblings and team up to work together; for example, in formation of a biofilm, which lends bacteria greater strength and better odds of survival."

The study points to the enzyme CysK as the potential catalyst to such bacterial communication -- like a secret handshake, or a password. In simpler terms, said Hayes, "If you have the right credentials, you're allowed into the club; otherwise you're turned away. There's a velvet rope, if you will, and if you're not one of the cool kids, you can't get in."

Although only UPEC was studied for this paper, Hayes said that the findings hold potential implications for pathogens from bacterial meningitis to the plague, as well as for plant-based bacteria that can devastate vegetation.

David Low, a UCSB professor of molecular, cellular, and developmental biology and secondary author on the paper, described the work by Hayes's laboratory as potentially groundbreaking for its insights into how bacteria communicate -- and the practical applications that could someday result.

"We are just starting to get some clues that bacteria may be talking to each other with a contact-dependent language," said Low. "They touch and respond to one another in different ways depending on the CDI systems and other genotypic factors. Our hope is that ultimately this work may aid the development of drugs that block or enhance touch-dependent communication, whether the bacteria is harmful or helpful."

The work was supported by grants from the National Institutes of Health and the National Science Foundation.

From sciencedaily

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Depression: An Evolutionary Byproduct of Immune System?

Some previous proposals for the role of depression in evolution have focused on how it affects behavior in a social context. A pair of psychiatrists addresses this puzzle in a different way, tying together depression and resistance to infection. They propose that genetic variations that promote depression arose during evolution because they helped our ancestors fight infection.

 Could depression be an evolutionary byproduct of the ability to fight infection?

An outline of their proposal appears online in the journal Molecular Psychiatry.

The co-authors are Andrew Miller, MD, William P. Timmie professor of psychiatry and behavioral sciences at Emory and director of psychiatric oncology at Winship Cancer Institute, and Charles Raison, MD, previously at Emory and now at the University of Arizona.

For several years, researchers have seen links between depression and inflammation, or over-activation of the immune system. People with depression tend to have higher levels of inflammation, even if they're not fighting an infection.

"Most of the genetic variations that have been linked to depression turn out to affect the function of the immune system," Miller says. "This led us to rethink why depression seems to stay embedded in the genome."

"The basic idea is that depression and the genes that promote it were very adaptive for helping people -- especially young children -- not die of infection in the ancestral environment, even if those same behaviors are not helpful in our relationships with other people," Raison says.

Infection was the major cause of death in humans' early history, so surviving infection was a key determinant in whether someone was able to pass on his or her genes. The authors propose that evolution and genetics have bound together depressive symptoms and physiological responses that were selected on the basis of reducing mortality from infection. Fever, fatigue/inactivity, social avoidance and anorexia can all be seen as adaptive behaviors in light of the need to contain infection, they write.

The theory provides a new explanation for why stress is a risk factor for depression. The link between stress and depression can be seen as the byproduct of a process that preactivates the immune system in anticipation of a wound, they write.

Similarly, a disruption of sleep patterns can be seen in both mood disorders and when the immune system is activated. This may come from our ancestors' need to stay on alert to fend off predators after injury, Miller says.

Miller and Raison's theory could also guide future research on depression. In particular, the presence of biomarkers for inflammation may be able to predict whether someone will respond to various treatments for depression.

Miller and Raison are involved in ongoing research on whether certain medications, which are normally used to treat auto-immune diseases, can be effective with treatment-resistant depression.

From sciencedaily

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City with Superfast Internet Invites Innovators to Play

Citizens in Chattanooga, Tennessee, have access to one-gigabit-per-second Internet—that's 100 times the U.S. national average, and fast enough to download a two-hour movie in about five seconds. The only question is: what to do with it?

 Wired up: These fiber-optic cables provide one-gigabit-per-second data to 150,000 homes and businesses in Chattanooga, Tennessee.

The city is hoping a contest with $300,000 in prize money will help answer that question. Entrants are invited to come up with clever ways of making use of the city's blisteringly fast Internet, which was installed in late 2010 with a $111 million U.S. Department of Energy grant, as part of federal stimulus efforts that also built out the city utility's long-planned smart grid. 

Some early entries include health-care applications, such as transferring larger files like CT scans in real-time so that specialists can serve a larger area. Ideas contributed by students include a platform for high-definition video debates, and international collaborations with students in Sri Lanka, London, Jamaica, and elsewhere.

But even if some great ideas come out of the contest, the fact remains that most people in the U.S. still have access to only relatively slow Internet connections. Late last year, the United States ranked 25th in the world for average available Internet speed. By the end of this year, South Korea, a world leader in Internet speed, will provide one-gigabit service nationwide for about $27 a month.

Furthermore, where superfast Internet is available in the U.S., it is typically prohibitively expensive. The Chattanooga service has been available for more than a year to 150,000 residential and commercial customers for $350 per month, but it has so far found only eight residential subscribers and 18 commercial ones.

Even so, in Tennessee they are optimistic that the contest will bring rewards. "Eventually, these fatter pipes will get filled with bandwidth-eating applications," says Jack Studer, partner at the Lamp Post Group, a VC firm in Chattanooga that, along with companies including Alcatel, Cisco, and IBM, is sponsoring the contests.

"What we are trying to do is inject some capital into innovation, with the goal of driving demand for higher-bandwidth networks and jump-start adoption across the country and world," Studer says. "We plan to do this for multiple years—in the second and third year, we may see a revolutionary jump to things we may not be thinking about now." 

 Get connected: A utility box in Chattanooga.

The $300,000 prize money will be split among students and entrepreneurs. Ten startups will get $15,000 this summer to develop and test their gigabit business ideas. A local judging panel will give a $100,000 prize for the winner. A separate student contest will carry a $50,000 prize. The deadline for entries is March 1.

Chattanooga is the only place in the United States providing such high-speed service. But others are on the way: Google is going into the Internet service provider business, stringing fiber on telephone poles in Kansas City, Missouri, and adjacent Kansas City, Kansas. The first of its customers should get a connection by the middle of 2012, a spokesman says. 

Video is the fastest-growing bandwidth-hogging app, and it could be an important driving force for faster Internet speeds. Google is, in fact, hoping to provide a TV service as part of its broadband efforts. Earlier this month, the company filed applications with the Missouri Public Service Commission and the Kansas Corporation Commission that would allow it to supply a TV service.

The U.S. Federal Communications Commission in 2010 defined "basic broadband" as at least four-megabits-per-second download speed and one-megabit-per-second upload speed. The efforts in Chattanooga and Kansas City are a step toward carrying out the FCC's ambitious National Broadband Plan, which aims to not only provide this minimal level of service to every community, but also to achieve the more ambitious goal of providing a majority of households with 100-megabit-per-second service by 2020. 

The Chattanooga network was built by the city-owned Electric Power Board. The utility uses the fiber partly for a smart electric grid that does things like detect overloads and reroute power on the fly to avoid costly brownouts.

History suggests that faster broadband spurs innovation and new business, says Rob Vietzke, vice president of network services at Internet2, a networking consortium that provides blazing fast Internet to research labs and government agencies. For example, in 2005, YouTube emerged with an application enabled by the growing availability of broadband in U.S. homes and businesses. "Projects like Chattanooga and Kansas City reopen the opportunity for innovation," Vietzke says. "You can't predict exactly what will happen, but it lays the groundwork for people to think differently about how they do their work."

One possible application of one-gigabit service involves streaming super-high definition video at four or more times the resolution of current HD technology, Vietzke says. Such high-quality streams could be useful for telemedicine and realistic remote meetings, but would require at least 100-megabit service, he adds.

Internet2, for its part, is working on delivering 100-gigabit service, initially to research centers in Indiana and Ohio—useful for such applications as crunching data from genomics research and from particle physics experiments at the Large Hadron Collider. (Some scientific instruments dish out even more data—deep-space telescopes, for example, can generate one terabit a second.)

All of this is way beyond the perceived needs of the average Chattanoogan. "Anything that makes my Netflix streaming move faster is okay with me," quips Tom Balázs, an assistant professor of English at the University of Tennessee in Chattanooga.

By David Talbot
From Technology Review

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