SCIENCE KNOWLEDGE

Using light to control light: Engineers invent new device that could increase Internet download speeds

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:49:00 -0800

The device uses the force generated by light to flop a mechanical switch of light on and off at a very high speed. This development could lead to advances in computation and signal processing using light instead of electrical current with higher performance and lower power consumption. The research results were published today in the online journal Nature Communications.

University of Minnesota researchers have invented a novel microscale mechanical switch of light on a silicon chip.

"This device is similar to electromechanical relays but operates completely with light," said Mo Li, an assistant professor of electrical and computer engineering in the University of Minnesota's College of Science and Engineering.

The new study is based on a previous discovery by Li and collaborators in 2008 where they found that nanoscale light conduits can be used to generate a strong enough optical force with light to mechanically move the optical waveguide (channel of information that carries light). In the new device, the researchers found that this force of light is so strong that the mechanical property of the device can be dominated completely by the optical effect rather than its own mechanical structure. The effect is amplified to control additional colored light signals at a much higher power level.

"This is the first time that this novel optomechanical effect is used to amplify optical signals without converting them into electrical ones," Li said.

Glass optical fibers carry many communication channels using different colors of light assigned to different channels. In optical cables, these different-colored light channels do not interfere with each other. This non-interference characteristic ensures the efficiency of a single optical fiber to transmit more information over very long distances. But this advantage also harbors a disadvantage. When considering computation and signal processing, optical devices could not allow the various channels of information to control each other easily…until now.

The researchers' new device has two optical waveguides, each carrying an optical signal. Placed between the waveguides is an optical resonator in the shape of a microscale donut (like a mini-Hadron collider.) In the optical resonator, light can circulate hundreds of times gaining intensity.

Using this resonance effect, the optical signal in the first waveguide is significantly enhanced in the resonator and generates a very strong optical force on the second waveguide. The second waveguide is released from the supporting material so that it moves in oscillation, like a tuning fork, when the force is applied on it. This mechanical motion of the waveguide alters the transmission of the optical signal. Because the power of the second optical signal can be many times higher than the control signal, the device functions like a mechanical relay to amplify the input signal.

Currently, the new optical relay device operates one million times per second. Researchers expect to improve it to several billion times per second. The mechanical motion of the current device is sufficiently fast to connect radio-frequency devices directly with fiber optics for broadband communication.

Li's team at University of Minnesota includes graduate students Huan Li, Yu Chen and Semere Tadesse and former postdoctoral fellow Jong Noh. Funding support of the project came from the University of Minnesota College of Science and Engineering and the Air Force Office of Scientific Research.

From phys

Engineers collaborate on inexpensive DNA sequencing method

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:46:00 -0800

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

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

TDK sees hard drive breakthrough in areal density

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:42:00 -0800

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

Acoustic Cell-Sorting Chip May Lead to Cell Phone-Sized Medical Labs

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:28:00 -0800

The device uses two beams of acoustic -- or sound -- waves to act as acoustic tweezers and sort a continuous flow of cells on a dime-sized chip, said Tony Jun Huang, associate professor of engineering science and mechanics, Penn State. By changing the frequency of the acoustic waves, researchers can easily alter the paths of the cells.

Slightly larger than a dime, this cell-sorting device uses two sound beams to act as acoustic tweezers.

Huang said that since the device can sort cells into five or more channels, it will allow more cell types to be analyzed simultaneously, which paves the way for smaller, more efficient and less expensive analytic devices.

"Eventually, you could do analysis on a device about the size of a cell phone," said Huang. "It's very doable and we're making in-roads to that right now."

Biological, genetic and medical labs could use the device for various types of analysis, including blood and genetic testing, Huang said.

Most current cell-sorting devices allow the cells to be sorted into only two channels in one step, according to Huang. He said that another drawback of current cell-sorting devices is that cells must be encapsulated into droplets, which complicates further analysis.

"Today, cell sorting is done on bulky and very expensive devices," said Huang. "We want to minimize them so they are portable, inexpensive and can be powered by batteries."

Using sound waves for cell sorting is less likely to damage cells than current techniques, Huang added.

In addition to the inefficiency and the lack of controllability, current methods produce aerosols, gases that require extra safety precautions to handle.

The researchers, who released their findings in the current edition of Lab on a Chip, created the acoustic wave cell-sorting chip using a layer of silicone -- polydimethylsiloxane. According to Huang, two parallel transducers, which convert alternating current into acoustic waves, were placed at the sides of the chip. As the acoustic waves interfere with each other, they form pressure nodes on the chip. As cells cross the chip, they are channeled toward these pressure nodes.

The transducers are tunable, which allows researchers to adjust the frequencies and create pressure nodes on the chip.

The researchers first tested the device by sorting a stream of fluorescent polystyrene beads into three channels. Prior to turning on the transducer, the particles flowed across the chip unimpeded. Once the transducer produced the acoustic waves, the particles were separated into the channels.

Following this experiment, the researchers sorted human white blood cells that were affected by leukemia. The leukemia cells were first focused into the main channel and then separated into five channels.

The device is not limited to five channels, according to Huang.

"We can do more," Huang said. "We could do 10 channels if we want, we just used five because we thought it was impressive enough to show that the concept worked."

Huang worked with Xiaoyun Ding, graduate student, Sz-Chin Steven Lin, postdoctoral research scholar, Michael Ian Lapsley, graduate student, Xiang Guo, undergraduate student, Chung Yu Keith Chan, doctoral student, Sixing Li, doctoral student, all of the Department of Engineering Science and Mechanics at Penn State; Lin Wang, Ascent BioNano Technologies; and J. Philip McCoy, National Heart, Lung and Blood Institute, National Institutes of Health.

The National Institutes of Health Director's New Innovator Award, the National Science Foundation, Graduate Research Fellowship and the Penn State Center for Nanoscale Science supported this work.

From sciencedaily

Thanks for the Transparent Memories: Progress in Quest for Reliable, Flexible Computer Memory for Transparent Electronics

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:25:00 -0800

This happens even when the work of art is on the nanoscale, where individual things make a strand of hair look like a redwood by comparison.

More than four years ago, a collection of students, postdoctoral researchers and professors at Rice University found themselves chiseling down into a mystery involving two of the most basic, common elements on Earth: carbon and silicon oxide.

Using graphene as crossbar terminals, Rice researchers are following through on groundbreaking research that shows silicon oxide, one of the most common materials on Earth, can be used as a reliable computer memory. The memories are flexible, transparent and can be built in 3-D configurations.

The group led by chemist James Tour came to a discovery of note: that it was possible to make bits of computer memory from those elements, but make them much smaller and perhaps better than anything on the market even today.

From that first revelation in 2008 to now, Tour and his team have steadily advanced the science of two-terminal memory devices, which he fully expects will become ubiquitous in the not-too-distant future.

The latest dispatch is a paper in the journal Nature Communications that describes transparent, non-volatile, heat- and radiation-resistant memory chips created in Tour's lab from those same basic elements, silicon and carbon. But a lot has happened since 2008, and these devices bear only a passing resemblance to the original memory unit.

In the new work, Tour and his co-authors detail their success at making memory chips from silicon oxide sandwiched between electrodes of graphene, the single-atom-thick form of carbon.

Even better, they were able to put those test chips onto flexible pieces of plastic, leading to paper-thin, see-through memories they hope can be manufactured with extraordinarily large capacities at a reasonable price. Think about what that can do for heads-up windshields or displays with embedded electronics, or even flexible, transparent cellphones.

"The interest is starting to climb," said Tour, Rice's Rice's T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science. "We're working with several companies that are interested either in getting their chips to do this kind of switching or in the possibility of making radiation-hard devices out of this."

In fact, samples of the chips have climbed all the way to the International Space Station (ISS), where memories created and programmed at Rice are being evaluated for their ability to withstand radiation in a harsh environment.

"Now, we've seen a couple of DARPA announcements asking for proposals for devices based on silicon oxide, the very thing we've shown. So there are other people seeing the feasibility of this approach," Tour said.

It wasn't always so, even if silicon oxide "is the most studied material in humankind," he said.

"Labs in the '60s and '70s that saw the switching effect didn't have the tools to understand what they were looking at," he said. "They didn't know how to exploit it; they called it a soft breakdown in silicon. To them, it was something bad."

In the original work at Rice, researchers put strips of graphite, the bulk form of carbon best known as pencil lead, across a silicon oxide substrate and noticed that applying strong voltage would break the carbon; lower voltages would repeatedly heal and re-break the circuit. They recognized a break could be a "0″ and a healed circuit a "1." That's a switch, the most basic memory state.

Manufacturers who have been able to fit millions of such switches on small devices in the likes of flash memory now find themselves bumping against the physical limits of their current architectures, which require three wires -- or terminals -- to control and read each bit.

But the Rice unit, requiring only two terminals, made it far less complicated. It meant arrays of two-terminal memory could be stacked in three-dimensional configurations that would vastly increase the amount of information a chip could hold.

And best of all, the mechanism that made it possible turned out not to be in the graphite, but the silicon oxide. In the breakthrough 2010 paper that followed the 2008 discovery, the researchers led by then-graduate student Jun Yao found that a strong jolt of voltage through a piece of silicon oxide stripped oxygen atoms from a channel only 5 nanometers wide, turning it into pure silicon. Lower voltages would break the channel or reconnect it, repeatedly, thousands of times.

"Jun was the first to recognize what he was seeing," Tour said. "Nobody believed him, though (Rice physicist) Doug Natelson said, 'You know, it's not out of the realm of possibility.' The people on the graphitic memory project were not at all excited about him saying this and they argued with Jun tooth and nail for a couple of years."

Yao struggled to convince his lab partners the switching effect wasn't due to the breaking graphite but to the underlying crystalline silicon. "Jun quietly continued his work and stacked up evidence, eventually building a working device with no graphite," Tour said. Still, he recalled, Yao's colleagues suspected that carbon in the system skewed the results. So he demonstrated another device with no possible exposure to carbon at all.

Yao's revelation became the basis for the next-generation memories now being designed in Tour's lab, where silicon oxides sandwiched between graphene layers are being attached to plastic sheets. There's not a speck of metal in the entire unit (with the exception of leads attached to the graphene electrodes). And the eye can see right through it.

"Now we're making these memories with about an 80 percent yield of working devices, which is pretty good for a non-industrial lab," Tour said. "When you get these ideas into industries' hands, they really sharpen it up."

The idea of transparency came later. "Silicon oxide is basically the same material as glass, so it should be transparent," Tour said. Graphene sheets, single-atom-thick carbon honeycombs, are almost completely transparent, too, and tests detailed in the new paper showed their ability to function as crossbar electrodes, a checkerboard array half above and half below the silicon oxide that creates a circuit where the lines intersect.

The marriage of silicon and graphene would extend the long-recognized utility of the first and prove once and for all the value of the second, long touted as a wonder material looking for a reason to be.

"It was a very rewarding experience," said Yao, now a postdoctoral researcher at Harvard, of his work at Rice. "I feel grateful that I stumbled on this, had the support of my advisers and persisted."

By good fortune, Yao was the rare graduate student with three advisers. As confusing as that may have seemed at the start of his Rice career, it was luck those advisers were digital systems expert Lin Zhong and condensed matter physicist Natelson, both rising stars in their fields, and Tour, a renowned chemist.

Each made important contributions to the project as it progressed. "Doug had very acute intuition about the underlying mechanism, and we constantly turned to Lin for his advice on the electronic architecture," Yao said.

Getting his story on Page 1 of the New York Times was enough of a thrill, but another was ahead as NASA decided to include samples of his chip in an experimental package bound for the space station. The day of Yao's planned departure for his postdoctoral job in Cambridge, Aug. 24, 2011, was to be the best of all as the HIMassSEE project lifted off from Central Asia aboard a cargo flight to the ISS. Minutes later, the unmanned craft crashed in Siberia.

Nearly a year later, a new set of chips made it to the ISS, where they will stay for two years to test their ability to hold a pattern when exposed to radiation in space.

In the meantime, Yao passed responsibility for the project to Jian Lin, a co-author of the new paper who joined the Tour and Natelson labs in 2011 as a postdoctoral researcher. Lin built the latest iterations of silicon oxide memories using crossbar graphene electrodes.

"Our lab members are excellent at synthesizing materials and I'm good at fabrication of devices for various applications, so we work together well," said Lin, whose primary interest is in the application of nanomaterials. "This group is a win-win for me."

Labs at other institutions have picked up the thread, carrying out their own experiments on silicon oxide memory. "The switching mechanism has pretty much been investigated," Lin said. "But from engineering or application perspectives, there are a lot of things that can be done."

So here silicon memory stands, a toddler full of promise. Researchers at Rice and elsewhere are working to increase silicon memory's capacity and improve its reliability while electronics manufacturers think hard about how to make it in bulk and put it into products.

Tour realizes impatience for scientific progress is a function of hurried times and not a failure of the process, but he counsels against frustration. "It's a very interesting system that has been slow to develop," he said, "as we've been working to understand the fundamental switching mechanism," a task largely accomplished by Yao and his Rice advisers in a paper published earlier this year. "This is now transitioning slowly into an applied system that could well be taken up as a future memory system.

"It is a good example of basic research," he said. "Now, others have to be able to look forward from the science and say, 'You know, there's a path to a product here.'"

Co-authors of the Nature Communications paper are Rice graduate students Yanhua Dai, Gedeng Ruan, Zheng Yan and Lei Li. Zhong is an associate professor of electrical and computer engineering. Natelson is a professor of physics and astronomy and of electrical and computer engineering.

The research was supported by the David and Lucille Packard Foundation, the Texas Instruments Leadership University Fund, the National Science Foundation and the Army Research Office.

From sciencedaily

Superman-Strength Bacteria Produce 24-Karat Gold

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:22:00 -0800

"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

Electronic Implant Dissolves in the Body

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:17:00 -0800

Researchers at the University of Illinois at Urbana-Champaign, Tufts University, and others have created fully biodegradable electronics that could allow doctors to implant medical sensors or drug delivery devices that dissolve when they're no longer needed. The transient circuits, described in today's issue of Science, can be programmed to disappear after a set amount of time based on the durability of their silk-protein coating.

Soluble silicon: This electronic circuit dissolves when exposed to water.

"You want the device to serve a useful function, but after that function is completed, you want it to simply disappear by dissolution and resorption into the body," says John Rogers, a physical chemist at the University of Illinois at Urbana-Champaign and senior author on the study.

The authors demonstrate this possibility with a resorbable device that can heat the area of a surgical cut to prevent bacterial growth. They implanted the heat-generating circuit into rats. After three weeks, the authors examined the site of the implant and found that the device had nearly completely disappeared, leaving only remnants of the silk coating, which is eliminated more slowly than the silicon and magnesium of the circuit itself.

The work builds upon previous efforts from Tufts University's Fiorenzo Omenetto (whose work won a 10 Emerging Technologies award in 2010) on using silk as a body-friendly mechanical support for electronics as well as a tunable coating that can be made to last days or months depending on chemical processing. By combining that technology with their own thin and flexible circuitry, Omenetto, Rogers, and the rest of their team were able to develop silicon-based electronics that completely biodegrade. Other groups are also working to develop biodegradable electronics, some with different materials that may not perform as reliably as the silicon device but might dissolve faster.

"The basic idea is to fabricate implants that are not only electronically active but that can degrade over time," says Chris Bettinger, a materials scientist at Carnegie Mellon University who is also developing such electronics. "Integration, I think, is the achievement here," he says of the study. "It's really impressive, with regards to how they were able to integrate all the materials."

The circuits themselves are made from magnesium electrodes and thin sheets of silicon. They are built on a support substrate of protein purified from silkworm silk. The thin silicon sheets, or nanomembranes, are an important part of the integrated technology, says Bettinger, because they are more flexible and easily broken down and eliminated by the body than other forms of the semiconductor.

The technology could be useful in a variety of biomedical implants, from treating surgical infections, as demonstrated, to drug delivery or disease diagnostics. But the potential extends beyond the body, says Rogers. "Environmental monitors or even consumer electronics might be interesting to build in this fashion, because it would help to eliminate a lot of waste streams with discarded electronics," he says.

By Susan Young
From Technology Review

Meet the Nimble-Fingered Interface of the Future

noreply@blogger.com (Unknown) — Wed, 3 Oct 2012 05:15:00 -0800

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

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

noreply@blogger.com (Unknown) — Thu, 16 Aug 2012 00:33:00 -0800

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

Designing Tiny Molecules That Glow in Water to Shed Light On Biological Processes

noreply@blogger.com (Unknown) — Thu, 16 Aug 2012 00:28:00 -0800

Previous studies have used water-soluble particles to bring organic molecules into water. What is novel about this system is the use of a photoswitching mechanism in combination with these particles.

This image shows live cells incubated with the polymer nanoparticles. The green color is the fluorescence coming from the molecules trapped within the nanoparticles

The findings published online by Chemistry-A European Journal, describe the creation of a fluorescent photoswitchable system that is more efficient than current technologies, says Francisco Raymo, professor of chemistry at the UM College of Arts and Sciences and principal investigator of this study.

"Finding a way to switch fluorescence inside cells is one of the main challenges in the development of fluorescent probes for bioimaging applications," Raymo says. "Our fluorescent switches can be operated in water efficiently, offering the opportunity to image biological samples with resolution at the nanometer level."

Fluorescent molecules are not water soluble; therefore Raymo and his team created their system by embedding fluorescent molecules in synthetic water-soluble nanoparticles called polymers that serve as transport vehicles into living cells. Once inside the cell, the fluorescence of the molecules trapped within the nanoparticles can be turned on and off under optical control.

"The polymers can preserve the properties of the fluorescent molecules and at the same time assist the transfer of the molecules into water," Raymo says. "It's a bit like having a fish in a bowl, so the fish can carry on with its activities in the bowl and the whole bowl can be transferred into a different environment."

The new system is faster and more stable than current methods. The fluorescent molecules glow when exposed simultaneously to ultraviolet and visible light and revert back to their original non-luminous state in less than 10 microseconds after the ultraviolet light is removed.

By using engineered synthetic molecules, the new system is able to overcome the natural wear down process that organic molecules are subject to when exposed to ultraviolet light.

"The system can be switched back and forth between the fluorescent and non-fluorescent states for hundreds of cycles, without sign of degradation," Raymo says.

The surface of the system can be customize to help it attach to specific molecules of interests, thus allowing researchers to visualize structures and activity within cells, in real time, with a resolution that would otherwise be impossible to achieve.

Raymo and his team will continue improving the properties of the molecules for future biomedical applications. The study is titled "Fast Fluorescence Switching within Hydrophilic Supramolecular Assemblies" Co-authors are Janet Cusido, Mutlu Battal, Erhan Deniz and Ibrahim Yildiz,Ph.D., students in the Department of Chemistry at UM; and Salvatore Sortino, associate professor of chemistry in the Department of Drug Sciences, University of Catania, Italy. The research was supported by the National Science Foundation.

From sciencedaily

First Direct Observations of Quantum Effects in an Optomechanical System

noreply@blogger.com (Unknown) — Thu, 16 Aug 2012 00:25:00 -0800

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

Gene Control, Delivered Directly to the Brain

noreply@blogger.com (Unknown) — Thu, 16 Aug 2012 00:21:00 -0800

A biotech company called Alnylam announced today that a small clinical trial for a genetic therapy based on RNA interference, or RNAi, suggests that the technique can have a powerful effect on its target gene. The therapeutic effect lasted for over a month with just one dose. The company is also working with a medical device maker, Medtronic, on a way to deliver RNAi treatment directly to the brain, in order to treat the degenerative brain disease Huntington's.

RNA Rx: An Alynlam chemist prepares RNA molecules.

The patients in the trial have a genetic disorder that originates in the liver and leads to the buildup of protein deposits in many organs. Alnylam, a Cambridge, Massachusetts-based company, says its RNAi therapeutic, given at its highest dose, reduces the amount of the faulty protein that spurs the disease by almost 94 percent.

The positive results add weight to the notion that RNAi therapeutics could eventually help patients with a range of genetic diseases. RNAi therapy involves researchers producing snippets of RNA, a close relative of DNA, that match a portion of a gene of interest. When administered, this so-called small interfering RNA (siRNA) causes the destruction of that gene's products before it can be turned into a protein. The specificity of RNAi for targeting particular genes has attracted a lot of interest from people who want to use it as a clinical treatment (see "Prescription RNA").

"Today's platforms target the protein that causes the disease and bind to that protein. We stop the protein from being made in the first place," says Barry Greene, president and chief operating officer of Alnylam.

But a recurring challenge for the therapeutic RNAi field is how to deliver the siRNAs to the right place in the body. On their own, the small molecules do not survive long in the bloodstream, so simply injecting a patient with a solution of unprotected siRNAs is not effective. "The key technical hurdle is getting the siRNA [inside] the right cells," says Greene.

For several of its projects, Alnylam uses nanoparticles to protect and deliver its siRNAs, which can then be delivered by injection. But for genetic diseases that originate in the brain, the body's own defenses, namely the blood-brain barrier, complicate delivery further. To circumvent the blood-brain barrier, which prevents most molecules from leaving the bloodstream and entering the brain, Alnylam has looked to a different delivery mechanism: direct dosing of unpackaged siRNAs.

Medtronic, a Minneapolis company that designs and manufactures medical devices, has devised a way to allow this. Together, the companies have developed a treatment that combines Alnylam's RNAi therapeutic with Medtronic's drug delivery technology to treat Huntington's.

Huntington's, for which there is no cure, is caused by the loss of neurons due to a toxic protein made by a tainted gene. The idea behind the new treatment is to stop at least some of that protein's production so that it cannot damage the brain.

The treatment would use a device made by Medtronic that is already implanted in more than 250,000 patients to treat chronic pain and spasticity. The device features a catheter connected to a drug pump that's surgically implanted into the abdomen. The pump pushes drugs through the device and into the fluid around the spinal cord. In the case of the Huntington's RNAi work, the system is adapted to deliver liquids directly into the brain tissue.

"To create pressure, it actively pumps the drug into the brain, and that pressure really moves the drug into the brain and further away than the drugs would otherwise go based on diffusion," says Lothar Krinke, vice president and manager of Medtronic's deep brain stimulation projects.

In a study published earlier this year, the researchers showed that the device can distribute the siRNA to around six cubic centimeters of brain tissue in a rhesus monkey. The results of the study suggest the treatment was safe over 28 days of infusion and showed that the protein product of the Huntington's-type gene in the monkeys was nearly halved, says Krinke.

Medtronic is currently leading the effort to push the device-drug treatment into the clinic. Although the company will not say when it anticipates initiating clinical trials, the work has been funded by CHDI, a nonprofit foundation focused on developing cures for Huntington's.

By Susan Young
From Technology Review

Augmented Reality, Wrapped Around Your Finger

noreply@blogger.com (Unknown) — Thu, 16 Aug 2012 00:17:00 -0800

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

First Heralded Single Photon Source Made from Silicon

noreply@blogger.com (Unknown) — Fri, 29 Jun 2012 19:26:00 -0800

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

New fuel cell keeps going after the hydrogen runs out

noreply@blogger.com (Unknown) — Fri, 29 Jun 2012 19:21:00 -0800

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

Google's futuristic glasses move closer to reality

noreply@blogger.com (Unknown) — Fri, 29 Jun 2012 19:16:00 -0800

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

Colorful creates passively cooled Nvidia graphics card

noreply@blogger.com (Unknown) — Fri, 29 Jun 2012 19:10:00 -0800

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

Microspheres Could Save Patients Whose Lungs Have Stopped Working

noreply@blogger.com (Unknown) — Fri, 29 Jun 2012 18:57:00 -0800

Researchers have developed a way to deliver oxygen to the body's organs safely—via gas-filled microparticles—even when the patient's lungs have stopped working. Doctors could one day use the method to quickly reverse oxygen deprivation in patients with acute loss of lung function while longer-term fixes such as heart-lung bypass support are put in place.

Air bubble: An intravenous infusion of oxygen-filled microparticles (the yellow sphere in this composite image) could carry the life-sustaining gas to red blood cells in patients with sudden loss of lung function.

Even short periods of oxygen deprivation put the vital organs of the body at risk. Typically, doctors feed oxygen-deprived patients the gas through ventilators such as tubes in the mouth or nose, but the treatment depends on functioning lungs. In situations where the airway is blocked or the lungs do not work, few options exist.

In such cases, injecting pure oxygen into the body is not an option because it can form bubbles in blood vessels and block blood flow. Some hospitals have machines that can oxygenate a patient's blood outside of the body, but the surgical procedure to hook up such a bypass machine is complicated and can take too long in an emergency, says study author John Kheir.

As a first-year fellow at Boston Children's Hospital a few years ago, Kheir treated a nine-month-old girl whose lungs had been damaged by pneumonia and were filled with blood. In the 20 or so minutes it took for Kheir and his colleagues to put her on the heart-lung bypass machine, she suffered severe brain injury from low oxygen levels and died. The experience led Kheir to work toward developing a fast-acting, intravenous treatment that could help patients like her with acute, severe lung injury. "The only way to save someone like that would be to inject oxygen directly into the vein," he says.

Blood substitutes that carry oxygen are available for transfusion, but are known to cause dangerous side effects and furthermore typically rely on functioning lungs. "There really is a need for something that you can pull off the shelf, and give to people to pull them through these critical periods," says Ann Weinacker, a lung and critical care doctor at the Stanford Chest Clinic.

Kheir's oxygen-filled microspheres, reported today in Science Translational Medicine, are around three micrometers in diameter and are diluted in a solution commonly used in transfusions so that the particles can flow through even small capillaries in the body. In test tubes, the researchers found the oxygen transferred from the microspheres to hemoglobin, the protein in red blood cells that carries oxygen, within four seconds. They then tested the microspheres in anesthetized rabbits with blocked windpipes. Although the rabbits were asphyxiated, their bodies were oxygenated and did not show signs of major injury to organs.

More research is necessary to determine how long the therapy can work and for how many patients it could be useful. "Situations where you have a short-term need [for oxygen] and everything else is working are not that common," says Gail Weinmann, a lung disease expert with the National Heart Lung and Blood Institute. But when those situations arise, a quick infusion of oxygen could be life-saving, she says. "As a bridge, even 15 minutes could make a difference in some situations."

Kheir says the intravenous oxygen delivery could help not only in the critical moments when heart-lung bypass machines are being set up, but also when patients are being put in intensive care on ventilators. Unstable patients with low lung function are also at risk of severely low oxygen levels, he says. "[The goal] is not to make ventilators obsolete, but to make patients healthier," says Kheir.

Kheir says that more lab animal work is needed to explore the clinical utility of the microsphere technology, which he and some of the study coauthors are patenting. "We are testing the ability of these particles to deliver oxygen in other clinical circumstances, such as cardiac arrest and severe bleeding," he says.

The team is also working on making the microspheres more stable, with the ultimate goal of creating an off-the-shelf solution that could be ready for quick use in emergency situations.

By Susan Young
From Technology Review

The Jets of the Future

noreply@blogger.com (Unknown) — Sat, 5 May 2012 18:11:00 -0800

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

Cell membrane is patterned like a patchwork quilt

noreply@blogger.com (Unknown) — Sat, 5 May 2012 18:03:00 -0800

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

First Light: Researchers Develop New Way to Generate Superluminal Pulses

noreply@blogger.com (Unknown) — Sat, 5 May 2012 18:01:00 -0800

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

Fine-tuning Nanotech to Target Cancer

noreply@blogger.com (Unknown) — Sat, 5 May 2012 17:59:00 -0800

The results of the human trials are startling. Even at a lower-than-usual dose, multiple lung metastases shrank or even disappeared after one patient received only two-hour-long intravenous infusions of an experimental cancer drug. Another patient saw her cervical tumor reduce by nearly 60 percent after six months of treatment. Though the drug trial—by Bind Biosciences in Cambridge, Massachusetts—of an experimental nanotechnology-based technique was designed simply to show whether the technology is safe, the encouraging results revive hopes that nanomedicine could realize its elusive promise.

Programmable particle: Bind's drug-delivery nanoparticle (artist's rendering).

For more than a decade, researchers have been trying to develop nanoparticles that would deliver drugs more effectively and safely. The idea is that a nanoparticle containing a drug compound could selectively target tumor cells or otherwise diseased cells, and avoid healthy ones. Antibodies or other molecules can be attached to the nanoparticle and used to precisely identify target cells. "One of the largest advantages of nanotechnology is you can engineer things in particle form so that chemotherapeutics can be targeted to tumor cells, protecting the healthy cells of the body and protecting patients from side effects," says Sara Hook, nanotechnology development projects manager with the National Cancer Institute. But executing this vision has been difficult. One challenge: a drug's behavior in the body can change dramatically when it's combined with nanoparticles. A nanoparticle can change a drug's solubility, toxicity, speed of action, and more—sometimes beneficially, sometimes not. If a drug's main problem is that it's toxic to off-target organs, then nanotechnology can ensure that it's delivered to diseased cells instead of healthy cells. But if a drug depends on being absorbed quickly by diseased cells to be effective, a nanoparticle may slow the process and turn an optimal therapeutic into second best.

Bind, which was launched in 2007, has attempted to overcome this problem by building its drug-targeting nanoparticles in a way that allows the company to systematically vary their structures and composition. Typically, targeted drug nanoparticles are produced in two steps: first, a drug is encapsulated in a nanoparticle, and second, the external surface of the particle is bound with targeting molecules that will steer the therapeutic ferry to diseased cells. Generating such nanoparticles can be difficult to control and replicate, which limits a researcher's ability to fine-tune the nanoparticle's surface properties. To avoid this pitfall, Bind synthesizes its drug-carrying nanoparticles using self-assembly.

Under the right conditions, the subunits of its nanoparticles—some of which already contain targeting molecules—assemble on their own. No complex and variable chemical reactions are needed to produce the nanoparticles, and the properties of each subunit can be tweaked. This also allows the company's researchers to test a variety of nanoparticle-drug combinations and identify the best candidates for a particular task. "We make hundreds of combinations to evaluate in order to optimize the performance of each drug," says Jeff Hrkach, senior vice president of technology research and development.

Bind cofounder Omid Farokhzad, associate professor at Brigham Women's Hospital and Harvard Medical School, came up with the novel method for building nanoparticles while he was a postdoctoral researcher in the lab of Robert Langer, an MIT chemical engineering professor. Langer's group had already developed nanoparticles capable of releasing drugs in a controlled manner, but the particles did not yet seek out cancer cells specifically. Farokhzad's first challenge was to create nanoparticles whose molecular instructions would bring them to cancer cells, but which remained anonymous within the bloodstream so that the immune system wouldn't destroy them. The second was coming up with a robust and reproducible manufacturing process.

Instead, Farokhzad and Langer devised a method by which the building blocks of the nanoparticle and the drug self-assemble into a final product. Two types of polymer combine to form the tangled mesh of Bind's drug-laden spherical nanoparticle. One of these polymers has two chemically and structurally distinct regions, or "blocks": a water-insoluble block that forms part of the mesh that encapsulates the drug, and a water-soluble block that gives the final product a stealthy corona to evade the immune system. The other type of polymer has three blocks: the same two as the first, as well as a third region that contains a targeting molecule—the signal that will ensure the final particles attach to the desired cell types. The drug-carrying nanoparticles are formed by simply mixing these polymers together with the drug in the appropriate conditions.

The self-assembling polymers can be produced in a repeatable and scalable fashion. But the method has an additional benefit, one that may be the real key to Bind's success. The method by which the nanoparticles are built—from individual preparations of the two-block and three-block polymers—would also let researchers use high-throughput screening approaches, akin to how medicinal chemists design and test new drug compounds. Each block could be tweaked—extend one block, change the charge on another—and the relative amounts of each polymer could be varied. With so many parameters for tinkering, Bind's scientists can screen many combinations.

Its first drug in clinical trials, Bind-014, carries a widely used chemotherapeutic called docetaxel through the bloodstream to cancer cells. The drug is packaged inside a ball-like nanostructure made of biodegradable polymers that protect the drug and shield it from the body's immune system. The external surface of each nanoparticle is dotted with molecules that target cancerous cells. Once the nanoparticle has reached its target, it sticks to the outside of the cell, which triggers the cell to engulf the particle. The drug diffuses out of the particle at a controlled rate and is released into the deranged cell.

Mark Davis, a professor of chemical engineering at Caltech, is hopeful that the few ongoing trials of targeted nanoparticle therapeutics, which include one developed in his lab as well as Bind-014, will demonstrate the technology's potential. "The medical community isn't going to get excited until there is [an advanced human trial] where we can show what these targeted nanoparticles actually do for patients in a statistically significant way." For now, the results from the 17 patients enrolled in the phase I trial of Bind-014 look promising, but a real test of efficacy will have to wait until phase II trials, which are likely to start later this year.

The "programmable" design used by Bind may be key to bringing more nanoparticle-targeted drugs to trial. The company's methods could be applied to any existing drugs or compounds, including those that may have been shelved by pharmaceutical companies because they proved too toxic to the whole body. "We believe we can have a very broad platform of drugs that we can develop," says Hrkach.

By Susan Young
From Technology Review

Spinning Spare Parts

noreply@blogger.com (Unknown) — Sat, 5 May 2012 17:55:00 -0800

Thin off-white threads of human cellular material spiral around the spindle of a machine that is braiding them into a sturdy rope. It sounds macabre, but the inspiration for the material, made by San Francisco–based Cytograft Tissue Engineering, is health, not horror: the biological strands could be used to weave blood vessel patches and grafts that a patient's body would readily accept for wound repair. The process is faster and could be more cost-effective than other methods of producing biological tissue replacements.

Clean crochet: A specialist weaves a blood vessel graft from human threads on a sterile tubular loom.

Much of today's tissue engineering depends on biodegradable but synthetic scaffolds for cells that will rebuild a piece of organ or tissue. Typically, the scaffolding is eventually destroyed by the body. Cytograft's woven tissues, however, seem to remain in the body and become populated with cells. "A long time ago we decided we were going to make strong tissues without any scaffolding," says Nicolas L'Heureux, Cytograft's cofounder and chief scientific officer. "Once you get it in the body, your body doesn't see it as foreign."

The company developed the "human textile" idea from earlier work using sheets of biological material to reconstruct blood vessels. Basically, researchers grow human skin cells in a culture flask under conditions that encourage the cells to lay down a sheet of what is known as extracellular matrix—a structural material produced by animal cells that makes up our connective tissue. Cytograft can harvest these sheets from the culture flasks and then roll them into tubes that become replacement blood vessels. Blood vessels produced in this manner are still being tested—but they have performed well, with no signs of rejection, in a few patients in Europe and South America.

The rolling process, however, is expensive and time-consuming, in part because cells must be used to fuse the tube together so that it is sturdy enough for transplantation. Slicing the sheets into thin ribbons that can be spooled into threads makes it possible to use automated weaving and braiding machines to create three-dimensional structures that do not require fusing. Cytograft's technique draws upon a long history of medical textiles, which are typically produced with synthetic fibers like polyester. "Creating textiles is an ancient and powerful technique, and combining it with biomaterials is exciting because it has so much more versatility than the sheet method," says Christopher Breuer, a surgeon, scientist, and tissue engineer at the Yale School of Medicine. "The notion of making blood vessels or more complex shapes like heart valves, or patches for the heart, is much easier to do with fibers," he says. "If you can make fibers of any length, then there is no limit to the size or shape that you can make."

Biological braids: A machine braids together 48 threads of human extracellular material.

Cytograft has long focused on building replacement blood vessels for people who need dialysis, which cleans the blood of patients with kidney failure. This treatment is severely damaging to the vein (usually in the forearm) through which the patient's blood is transferred.

Cytograft is not yet testing its woven blood vessels in patients, but it has approximated the needs of dialysis patients in dogs with vessel grafts implanted in their legs. The preclinical dog work has shown that the grafts are resistant to puncture damage and that very little blood leaks from the weave, says L'Heureux.

Cytograft's implants remain intact after months, suggesting that the body accepts the grafts and does not try to break them down. "Other materials get remodeled very aggressively," says L'Heureux. "With our tissue, it is so innocuous the body does not see a danger."

That's partly because Cytograft's implants contain no cells. Though the company's earlier implants were made of extracellular matrix produced from a patient's own cells, its researchers can now harvest the material from cells unrelated to the person receiving the graft and remove the "donor" cells completely. "We don't need the cells," says L'Heureux. "The cells can come from the patients after implantation."

Without any foreign cells to alert a patient's immune system, the company could produce blood vessels ahead of time for use in any patient. Such replacement vessels would be less expensive and more readily accessible than what's available today. "One of Cytograft's biggest advantages will be off-the-shelf availability," says Breuer.

The company is also working on a technique in which the cell-produced sheets are processed into particles instead of threads. The biological bits can then be molded together, says L'Heureux, giving tissue engineers two advantages. Molding the particles together leaves a complex network of channels behind—exactly what tissues engineers will need in order to produce, eventually, something like a liver, pancreas, or kidney. With most other technology, there is "no guarantee that the channels will be maintained," says L'Heureux. The particles could also be injected, he says, which could add volume to tissues for cosmetic or reconstructive purposes.

By Susan Young
From Technology Review

Physicists Crack Fusion Mystery

noreply@blogger.com (Unknown) — Sat, 5 May 2012 17:46:00 -0800

One reason it's taking decades to develop fusion reactors that can generate electricity is that physicists don't completely understand what's going on in the high-temperature plasma inside a reactor. Under certain conditions, the plasma—which is where fusion reactions take place—disappears in under a millisecond.

Plasma chamber: This experimental fusion reactor at MIT could test the new theory.

A new theory developed by researchers at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) explains what happens just before the plasma disappears. The explanation could help engineers design better reactors. And that might help them increase the power output of a reactor, perhaps doubling the electricity they could produce, and making fusion reactors more economical.

Researchers have made a lot of progress on fusion technology—since 1970, the energy produced in experimental fusion reactors has increased by about 12 orders of magnitude, greater than the improvement in processing power in microchips over the same period, says Martin Greenwald, a fusion researcher at MIT. But for all the improvements in fusion research reactors, they still aren't useful—they don't produce more energy than they consume, and they can't be run continuously, both of which would be necessary for a power plant.

The new work, like so much in the realm of fusion research, is a step toward practical fusion power, but by no means does it solve all the problems. Based on experiments, there is a practical limit to how dense the plasma in a reactor can be. Beyond a certain density, the plasma becomes unstable, dissipates its energy, and disappears. Because researchers don't understand exactly what causes this, it's difficult to predict exactly when the collapse will happen, so researchers avoid getting close to that limit in experimental reactors. The Princeton work allows engineers to better predict what will happen in the reactor, potentially allowing them to design reactors that get closer to a theoretically optimum density for the plasma. That, in turn, could increase the amount of power a fusion power plant could generate.

According to the researchers' theory, islands develop within the plasma that cool off and cause the plasma to disappear. These islands—which are easily identified—could be selectively heated with microwaves, the researchers think, which could keep the plasma stable.

David Gates, a principal research scientist at PPPL and one of the key researchers on the project, says he expects they will be able to test the theory in research reactors this year.

While the theory is plausible, Greenwald says, it doesn't solve all the problems for reactors. It only explains part of the mechanisms involved in limiting the density of the plasma. And researchers still need to solve many practical problems before optimizing energy density is even an issue, he says.

Solving these problems will require a combination of better theories, more computing power, better algorithms, and big experiments. That's why researchers still say practical fusion power plants remain decades away.

By Kevin Bullis
From Technology Review

New App Watches Your Every Move

noreply@blogger.com (Unknown) — Sat, 5 May 2012 17:42:00 -0800

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