New Device Harnesses Sun and Sewage to Produce Hydrogen Fuel

New Device Harnesses Sun and Sewage to Produce Hydrogen Fuel

  9:24:00 PM    Science Lover

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A novel device that uses only sunlight and wastewater to produce hydrogen gas could provide a sustainable energy source while improving the efficiency of wastewater treatment.

The new hybrid solar-microbial device is self-driven 
and self-sustained, because the combined energy from 
the organic matter (harvested by the MFC) and sunlight 
(captured by the PEC) is sufficient to drive electrolysis 
of water. (Credit: Image courtesy of University 
of California - Santa Cruz)

A research team led by Yat Li, associate professor of chemistry at the University of California, Santa Cruz, developed the solar-microbial device and reported their results in a paper published in the American Chemical Society journal ACS Nano. The hybrid device combines a microbial fuel cell (MFC) and a type of solar cell called a photoelectrochemical cell (PEC). In the MFC component, bacteria degrade organic matter in the wastewater, generating electricity in the process. The biologically generated electricity is delivered to the PEC component to assist the solar-powered splitting of water (electrolysis) that generates hydrogen and oxygen.

Either a PEC or MFC device can be used alone to produce hydrogen gas. Both, however, require a small additional voltage (an "external bias") to overcome the thermodynamic energy barrier for proton reduction into hydrogen gas. The need to incorporate an additional electric power element adds significantly to the cost and complication of these types of energy conversion devices, especially at large scales. In comparison, Li's hybrid solar-microbial device is self-driven and self-sustained, because the combined energy from the organic matter (harvested by the MFC) and sunlight (captured by the PEC) is sufficient to drive electrolysis of water.

In effect, the MFC component can be regarded as a self-sustained "bio-battery" that provides extra voltage and energy to the PEC for hydrogen gas generation. "The only energy sources are wastewater and sunlight," Li said. "The successful demonstration of such a self-biased, sustainable microbial device for hydrogen generation could provide a new solution that can simultaneously address the need for wastewater treatment and the increasing demand for clean energy."

Microbial fuel cells rely on unusual bacteria, known as electrogenic bacteria, that are able to generate electricity by transferring metabolically-generated electrons across their cell membranes to an external electrode. Li's group collaborated with researchers at Lawrence Livermore National Laboratory (LLNL) who have been studying electrogenic bacteria and working to enhance MFC performance. Initial "proof-of-concept" tests of the solar-microbial (PEC-MFC) device used a well-studied strain of electrogenic bacteria grown in the lab on artificial growth medium. Subsequent tests used untreated municipal wastewater from the Livermore Water Reclamation Plant. The wastewater contained both rich organic nutrients and a diverse mix of microbes that feed on those nutrients, including naturally occurring strains of electrogenic bacteria.

When fed with wastewater and illuminated in a solar simulator, the PEC-MFC device showed continuous production of hydrogen gas at an average rate of 0.05 m3/day, according to LLNL researcher and coauthor Fang Qian. At the same time, the turbid black wastewater became clearer. The soluble chemical oxygen demand--a measure of the amount of organic compounds in water, widely used as a water quality test--declined by 67 percent over 48 hours.

The researchers also noted that hydrogen generation declined over time as the bacteria used up the organic matter in the wastewater. Replenishment of the wastewater in each feeding cycle led to complete restoration of electric current generation and hydrogen gas production.

Qian said the researchers are optimistic about the commercial potential for their invention. Currently they are planning to scale up the small laboratory device to make a larger 40-liter prototype continuously fed with municipal wastewater. If results from the 40-liter prototype are promising, they will test the device on site at the wastewater treatment plant.

"The MFC will be integrated with the existing pipelines of the plant for continuous wastewater feeding, and the PEC will be set up outdoors to receive natural solar illumination," Qian said.

"Fortunately, the Golden State is blessed with abundant sunlight that can be used for the field test," Li added.

Qian and Hanyu Wang, a graduate student in Li's lab at UC Santa Cruz, are co-first authors of the ACS Nano paper. The other coauthors include UCSC graduate student Gongming Wang; LLNL researcher Yongqin Jiao; and Zhen He of Virginia Polytechnic Institute & State University. This research was supported by the National Science Foundation and Department of Energy.  

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New Light On Possible 'Fifth Force of Nature'

New Light On Possible 'Fifth Force of Nature'

  7:52:00 PM    Science Lover

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In a breakthrough for the field of particle physics, Professor of Physics Larry Hunter and colleagues at Amherst College and The University of Texas at Austin have established new limits on what scientists call "long-range spin-spin interactions" between atomic particles. These interactions have been proposed by theoretical physicists but have not yet been seen. Their observation would constitute the discovery of a "fifth force of nature" (in addition to the four known fundamental forces: gravity, weak, strong and electromagnetic) and would suggest the existence of new particles, beyond those presently described by the Standard Model of particle physics.

This picture depicts the long-range spin-spin interaction (blue wavy lines) in which the spin-sensitive detector on Earth’s surface interacts with geoelectrons (red dots) deep in Earth’s mantle. The arrows on the geoelectrons indicate their spin orientations, opposite that of Earth’s magnetic field lines (white arcs). (Credit: Illustration: Marc Airhart (University of Texas at Austin) and Steve Jacobsen (Northwestern University).)

The new limits were established by considering the interaction between the spins of laboratory fermions (electrons, neutrons and protons) and the spins of the electrons within Earth. To make this study possible, the authors created the first comprehensive map of electron polarization within Earth induced by the planet's geomagnetic field.

Hunter -- along with emeritus Amherst physics professor Joel Gordon; postdoctoral fellow Stephen Peck; student researcher Daniel Ang '15; and Jung-Fu "Afu" Lin, associate professor of geosciences at UT Austin -- co-authored a paper about their work that appears in this week's issue of the journal Science. The highly interdisciplinary research relies on geophysics, atomic physics, particle physics, mineral physics, solid-state physics and nuclear physics to reach its conclusions.

The paper describes how the team combined a model of Earth's interior with a precise map of the planet's geomagnetic field to produce a map of the magnitude and direction of electron spins throughout Earth. Their model was based in part on insights gained from Lin's studies of spin transitions at the high temperatures and pressures of Earth's interior.

Every fundamental particle (every electron, neutron and proton, to be specific), explained Hunter, has the intrinsic atomic property of "spin." Spin can be thought of as a vector -- an arrow that points in a particular direction. Like all matter, Earth and its mantle -- a thick geological layer sandwiched between the thin outer crust and the central core -- are made of atoms. The atoms are themselves made up of electrons, neutrons and protons that have spin. Earth's magnetic field causes some of the electrons in the mantle's minerals to become slightly spin-polarized, meaning the directions in which their spins point are no longer completely random, but have some net orientation.

Earlier experiments, including one in Hunter's laboratory, explored whether their laboratory spins prefer to point in a particular direction. "We know, for example, that a magnetic dipole has a lower energy when it is oriented parallel to the geomagnetic field and it lines up with this particular direction -- that is how a compass works," he explained. "Our experiments removed this magnetic interaction and looked to see if there might be some other interaction that would orient our experimental spins. One interpretation of this 'other' interaction is that it could be a long-range interaction between the spins in our apparatus, and the electron spins within the Earth, that have been aligned by the geomagnetic field. This is the long-range spin-spin interaction we are looking for."

So far, no experiment has been able to detect any such interaction. But in Hunter's paper, the researchers describe how they were able to infer that such so-called spin-spin forces, if they exist, must be incredibly weak -- as much as a million times weaker than the gravitational attraction between the particles. At this level, the experiments can constrain "torsion gravity" -- a proposed theoretical extension of Einstein's Theory of General Relativity. Given the high sensitivity of the technique Hunter and his team used, it may provide a useful path for future experiments that will refine the search for such a fifth force. If a long-range spin-spin force is found, it not only would revolutionize particle physics but might eventually provide geophysicists with a new tool that would allow them to directly study the spin-polarized electrons within Earth.

"If the long-range spin-spin interactions are discovered in future experiments, geoscientists can eventually use such information to reliably understand the geochemistry and geophysics of the planet's interior," said Lin.

Possible future discoveries aside, Hunter said that he was pleased that this particular project enabled him to work with Lin. "When I began investigating spin transitions in the mantle, all of the literature led to him," he explained. "I was thrilled that he was interested in the project and willing to sign on as a collaborator. He has been a good teacher and has had enormous patience with my ignorance about geophysics. It has been a very fruitful collaboration."

Lin had his own take: "The most rewarding and surprising thing about this project was realizing that particle physics could actually be used to study the deep Earth."

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Human Evolution Driven By Changing Environment

Human Evolution Driven By Changing Environment

  9:46:00 AM    Science Lover

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A series of rapid environmental changes in East Africa roughly 2 million years ago may be responsible for driving human evolution, according to researchers at Penn State and Rutgers University.

The researchers examined lake sediments from Olduvai Gorge in northern Tanzania, looking for biomarkers -- fossil molecules -- from ancient trees and grasses. (Credit: Gail Ashley)

"The landscape early humans were inhabiting transitioned rapidly back and forth between a closed woodland and an open grassland about five to six times during a period of 200,000 years," said Clayton Magill, graduate student in geosciences at Penn State. "These changes happened very abruptly, with each transition occurring over hundreds to just a few thousand years."

According to Katherine Freeman, professor of geosciences, Penn State, the current leading hypothesis suggests that evolutionary changes among humans during the period the team investigated were related to a long, steady environmental change or even one big change in climate.

"There is a view this time in Africa was the 'Great Drying,' when the environment slowly dried out over 3 million years," she said. "But our data show that it was not a grand progression towards dry; the environment was highly variable."

According to Magill, many anthropologists believe that variability of experience can trigger cognitive development.

"Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response," he said. "Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes. The result can be increased brain size and cognition, changes in locomotion and even social changes -- how you interact with others in a group. Our data are consistent with these hypotheses. We show that the environment changed dramatically over a short time, and this variability coincides with an important period in our human evolution when the genus Homo was first established and when there was first evidence of tool use."

The researchers -- including Gail Ashley, professor of earth and planetary sciences, Rutgers University -- examined lake sediments from Olduvai Gorge in northern Tanzania. They removed the organic matter that had either washed or was blown into the lake from the surrounding vegetation, microbes and other organisms 2 million years ago from the sediments. In particular, they looked at biomarkers -- fossil molecules from ancient organisms -- from the waxy coating on plant leaves.

"We looked at leaf waxes because they're tough, they survive well in the sediment," said Freeman.

The team used gas chromatography and mass spectrometry to determine the relative abundances of different leaf waxes and the abundance of carbon isotopes for different leaf waxes. The data enabled them to reconstruct the types of vegetation present in the Olduvai Gorge area at very specific time intervals.

The results showed that the environment transitioned rapidly back and forth between a closed woodland and an open grassland.

To find out what caused this rapid transitioning, the researchers used statistical and mathematical models to correlate the changes they saw in the environment with other things that may have been happening at the time, including changes in the Earth's movement and changes in sea-surface temperatures.

"The orbit of the Earth around the sun slowly changes with time," said Freeman. "These changes were tied to the local climate at Olduvai Gorge through changes in the monsoon system in Africa. Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water. The rain patterns that drive the plant patterns follow this monsoon circulation. We found a correlation between changes in the environment and planetary movement."

The team also found a correlation between changes in the environment and sea-surface temperature in the tropics.

"We find complementary forcing mechanisms: one is the way Earth orbits, and the other is variation in ocean temperatures surrounding Africa," Freeman said. The researchers recently published their results in the Proceedings of the National Academy of Sciences along with another paper in the same issue that builds on these findings. The second paper shows that rainfall was greater when there were trees around and less when there was a grassland.

"The research points to the importance of water in an arid landscape like Africa," said Magill. "The plants are so intimately tied to the water that if you have water shortages, they usually lead to food insecurity.

"Together, these two papers shine light on human evolution because we now have an adaptive perspective. We understand, at least to a first approximation, what kinds of conditions were prevalent in that area and we show that changes in food and water were linked to major evolutionary changes."

The National Science Foundation funded this research.

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Gravity Lenses: When Galaxies Eat Galaxies

Gravity Lenses: When Galaxies Eat Galaxies

  9:44:00 AM    Science Lover

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Using gravitational "lenses" in space, University of Utah astronomers discovered that the centers of the biggest galaxies are growing denser -- evidence of repeated collisions and mergers by massive galaxies with 100 billion stars.

This image, taken by the Hubble Space Telescope, shows 
a ring of light from a distant galaxy created when a closer 
galaxy in the  foreground – not shown in this processed 
image – acts as a “gravitational lens” to bend the light 
from the more distant galaxy into the ring of light, 
known as an Einstein ring. In a new study, University of 
Utah astronomer Adam Bolton and colleagues measured 
these Einstein rings to determine the mass of 79 lens 
galaxies that are massive elliptical galaxies, the largest 
kind of galaxy with 100 billion stars. The study found 
the centers of these big galaxies are getting denser over 
time, evidence of repeated collisions between massive 
galaxies. (Credit: Joel Brownstein, University of Utah, 
for NASA/ESA and the Sloan Digital Sky Survey)

"We found that during the last 6 billion years, the matter that makes up massive elliptical galaxies is getting more concentrated toward the centers of those galaxies. This is evidence that big galaxies are crashing into other big galaxies to make even bigger galaxies," says astronomer Adam Bolton, principal author of the new study.

"Most recent studies have indicated that these massive galaxies primarily grow by eating lots of smaller galaxies," he adds. "We're suggesting that major collisions between massive galaxies are just as important as those many small snacks."

The new study -- published recently in The Astrophysical Journal -- was conducted by Bolton's team from the Sloan Digital Sky Survey-III using the survey's 2.5-meter optical telescope at Apache Point, N.M., and the Earth-orbiting Hubble Space Telescope.

The telescopes were used to observe and analyze 79 "gravitational lenses," which are galaxies between Earth and more distant galaxies. A lens galaxy's gravity bends light from a more distant galaxy, creating a ring or partial ring of light around the lens galaxy.

The size of the ring was used to determine the mass of each lens galaxy, and the speed of stars was used to calculate the concentration of mass in each lens galaxy.

Bolton conducted the study with three other University of Utah astronomers -- postdoctoral researcher Joel Brownstein, graduate student Yiping Shu and undergraduate Ryan Arneson -- and with these members of the Sloan Digital Sky Survey: Christopher Kochanek, Ohio State University; David Schlegel, Lawrence Berkeley National Laboratory; Daniel Eisenstein, Harvard-Smithsonian Center for Astrophysics; David Wake, Yale University; Natalia Connolly, Hamilton College, Clinton, N.Y.; Claudia Maraston, University of Portsmouth, U.K.; and Benjamin Weaver, New York University.

Big Meals and Snacks for Massive Elliptical Galaxies

The new study deals with the biggest, most massive kind of galaxies, known as massive elliptical galaxies, which each contain about 100 billion stars. Counting unseen "dark matter," they contain the mass of 1 trillion stars like our sun.

"They are the end products of all the collisions and mergers of previous generations of galaxies," perhaps hundreds of collisions," Bolton says.

Despite recent evidence from other studies that massive elliptical galaxies grow by eating much smaller galaxies, Bolton's previous computer simulations showed that collisions between large galaxies are the only galaxy mergers that lead, over time, to increased mass density on the center of massive elliptical galaxies.

When a small galaxy merges with a larger one, the pattern is different. The smaller galaxy is ripped apart by gravity from the larger galaxy. Stars from the smaller galaxy remain near the outskirts -- not the center -- of the larger galaxy.

"But if you have two roughly comparable galaxies and they are on a collision course, each one penetrates more toward the center of the other, so more mass ends up in the center," Bolton says.

Other recent studies indicate stars are spread more widely within galaxies over time, supporting the idea that massive galaxies snack on much smaller ones.

"We're finding galaxies are getting more concentrated in their mass over time even though they are getting less concentrated in the light they emit," Bolton says.

He believes large galaxy collisions explain the growing mass concentration, while galaxies gobbling smaller galaxies explain more starlight away from galactic centers.

"Both processes are important to explain the overall picture," Bolton says. "The way the starlight evolves cannot be explained by the big collisions, so we really need both kinds of collisions, major and minor -- a few big ones and a lot of small ones."

The new study also suggests the collisions between large galaxies are "dry collisions" -- meaning the colliding galaxies lack large amounts of gas because most of the gas already has congealed to form stars -- and that the colliding galaxies hit each other "off axis" or with what Bolton calls "glancing blows" rather than head-on.

Sloan Meets Hubble: How the Study Was Conducted

The University of Utah joined the third phase of the Sloan Digital Sky Survey, known as SDSS-III, in 2008. It involves about 20 research institutions around the world. The project, which continues until 2014, is a major international effort to map the heavens as a way to search for giant planets in other solar systems, study the origin of galaxies and expansion of the universe, and probe the mysterious dark matter and dark energy that make up most of the universe.

Bolton says his new study was "almost gravy" that accompanied an SDSS-III project named BOSS, for Baryon Oscillation Spectrographic Survey. BOSS is measuring the history of the universe's expansion with unprecedented precision. That allows scientists to study the dark energy that accelerates expansion of the universe. The universe is believed to be made of only 4 percent regular matter, 24 percent unseen "dark matter" and 72 percent yet-unexplained dark energy.

During BOSS' study of galaxies, computer analysis of light spectra emitted by galaxies revealed dozens of gravitational lenses, which were discovered because the signatures of two different galaxies are lined up.

Bolton's new study involved 79 gravitational lenses observed by two surveys:

- The Sloan Survey and the Hubble Space Telescope collected images and emitted-light color spectra from relatively nearby, older galaxies -- including 57 gravitational lenses -- 1 billion to 3 billion years back into the cosmic past.

- Another survey identified 22 lenses among more distant, younger galaxies from 4 billion to 6 billion years in the past.

The rings of light around gravitational-lens galaxies are named "Einstein rings" because Albert Einstein predicted the effect, although he wasn't the first to do so.

"The more distant galaxy sends out diverging light rays, but those that pass near the closer galaxy get bent into converging light rays that appear to us as of a ring of light around the closer galaxy," says Bolton.

The greater the amount of matter in a lens galaxy, the bigger the ring. That seems counterintuitive, but the larger mass pulls with enough gravity to make the distant star's light bend so much that lines of light cross as seen by the observer, creating a bigger ring.

If there is more matter concentrated near the center of a galaxy, the faster stars will be seen moving toward or being slung away from the galactic center, Bolton says.

Alternative Theories

Bolton and colleagues acknowledge their observations might be explained by theories other than the idea that galaxies are getting denser in their centers over time:

- Gas that is collapsing to form stars can increase the concentration of mass in a galaxy. Bolton argues the stars in these galaxies are too old for that explanation to work.

- Gravity from the largest massive galaxies strips neighboring "satellite" galaxies of their outskirts, leaving more mass concentrated in the centers of the satellite galaxies. Bolton contends that process is not likely to produce the concentration of mass observed in the new study and explain how the extent of that central mass increases over time.

- The researchers merely detected the boundary in each galaxy between the star-dominated inner regions and the outer regions, which are dominated by unseen dark matter. Under this hypothesis, the appearance of growing galaxy mass concentration over time is due to a coincidence in researchers' measurement method, namely that they are measuring younger galaxies farther from their centers and measuring older galaxies closer to their centers, giving an illusion of growing mass concentration in galactic centers over time. Bolton says this measurement difference is too minor to explain the observed pattern of matter density within the lens galaxies.

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Coursera makes top college courses free online

Coursera makes top college courses free online

  8:53:00 AM    Science Lover

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Daphne Koller and Andrew Ng share a vision in which anyone, no matter how destitute, can expand their minds and prospects with lessons from the world's top universities.

Coursera co-founders Andrew Ng and Daphne Koller

That dream was joined this week by a dozen vaunted academic institutions including Duke University, the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland and the University of Edinburgh in Scotland.

The schools will add online versions of classes to Coursera.org, a website launched by Stanford University professors Koller and Ng early this year with debut offerings from Princeton, Stanford and two other US universities.

"We have a vision where students everywhere around the world, regardless of country, family circumstances or financial circle have access to top quality education whether to expand their minds or learn valuable skills," Koller said.

"Where education becomes a right, not a privilege."

Academic institutions are increasingly turning to the Internet as an educational platform. A Khan Academy website created by Massachusetts Institute of Technology (MIT) graduate Salman Khan provides thousands of video lectures.

The nonprofit behind prestigious TED gatherings recently launched a TED-Ed channel at YouTube that teams accomplished teachers with talented animators to make videos that captivate while they educate.

In May, Harvard University and MIT announced that they were teaming up to expand their online education programs -- and invited other institutions to jump on board.

Called edX, the $60 million joint venture builds on MIT's existing MITx platform that enables video lesson segments, embedded quizzes, immediate feedback, online laboratories and student-paced learning.

"Universities have come to realize that online is not a fad," Koller said. "The question is not whether to engage in this area but how to do it."

Coursera classes are free, and completion certificates are issued that people can use to win jobs or improve careers.

"If a student takes a Stanford computer class and a Princeton business class, it shows they are motivated and have skills," Koller said. "We know it has helped employees get better jobs."

Coursera is distinguishing itself with essentially virtual versions of real classes.

"A lot of what is out there is basically video with, perhaps, some static content like lecture notes," Koller said.

"We are providing an actual course exchange were people register and there is weekly homework that is graded with feedback about how they are doing."

Coursera classes launched in February with most of the courses slated to begin in the coming months but it has already attracted students in 190 countries, according to Koller.

Coursera uses crowd-sourcing to translate material into various languages and hopes to connect with French-speaking populations around the world with EPFL classes.

Hoping to spread knowledge around the world, Coursera is a way to inspire faculty to try new methods of teaching and find ways that Internet Age tools can enhance on-campus courses, according to Duke provost Peter Lange.

"Our faculty is incredibly excited by the idea of trying it out and seeing if we can learn from it," Lange said.

"I love the idealism of it; the potential to reach people who might never get the chance to attend the university."

Duke designs its online courses to get students involved, complete with social networking tools for collaborating outside of classes.

"This is a great experiment in innovation and learning," Lange said.

As of Friday, Coursera boasted about 740,000 students and that number is expected to soar as word spreads and class offerings expand.

Coursera plans to keep classes free but perhaps one day make money for operations by charging for course completion certificates or matching employers with qualified workers.

"Current ethos in Silicon Valley is that if you build a website that people keep coming back to and is changing the lives of millions, you can eventually make money," Koller said.

"If and when we develop revenue, universities will share in it."

Paying the bills is not a worry at Coursera due to generous backing that includes a $3.7 million combined investment by the University of Pennsylvania and the California Institute of Technology, as well as funding from venture capital powerhouse Kleiner Perkins Caufield & Byers.

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Quantum Computers Move Closer to Reality, Thanks to Highly Enriched and Highly Purified Silicon

Quantum Computers Move Closer to Reality, Thanks to Highly Enriched and Highly Purified Silicon

  2:57:00 PM    Science Lover

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The quantum computer is a futuristic machine that could operate at speeds even more mind-boggling than the world's fastest super-computers.

SFU physicist Mike Thewalt and grad student Kamyar 
Saeedi with a sample of highly isotopically enriched silicon - 
its unique properties could advance quantum computing. 
(Credit: Image courtesy of Simon Fraser University)

Research involving physicist Mike Thewalt of Simon Fraser University offers a new step towards making quantum computing a reality, through the unique properties of highly enriched and highly purified silicon.

Quantum computers right now exist pretty much in physicists' concepts, and theoretical research. There are some basic quantum computers in existence, but nobody yet can build a truly practical one -- or really knows how.

Such computers will harness the powers of atoms and sub-atomic particles (ions, photons, electrons) to perform memory and processing tasks, thanks to strange sub-atomic properties.

What Thewalt and colleagues at Oxford University and in Germany have found is that their special silicon allows processes to take place and be observed in a solid state that scientists used to think required a near-perfect vacuum.

And, using this 28Si they have extended to three minutes -- from a matter of seconds -- the time in which scientists can manipulate, observe and measure the processes.

"It's by far a record in solid-state systems," Thewalt says. "If you'd asked people a few years ago if this was possible, they'd have said no. It opens new ways of using solid-state semi-conductors such as silicon as a base for quantum computing.

"You can start to do things that people thought you could only do in a vacuum. What we have found, and what wasn't anticipated, are the sharp spectral lines (optical qualities) in the 28Silicon we have been testing. It's so pure, and so perfect. There's no other material like it."

But the world is still a long way from practical quantum computers, he notes.

Quantum computing is a concept that challenges everything we know or understand about today's computers.

Your desktop or laptop computer processes "bits" of information. The bit is a fundamental unit of information, seen by your computer has having a value of either "1" or "0."

That last paragraph, when written in Word, contains 181 characters including spaces. In your home computer, that simple paragraph is processed as a string of some 1,448 "1"s and "0"s.

But in the quantum computer, the "quantum bit" (also known as a "qubit") can be both a "1" and a "0" -- and all values between 0 and 1 -- at the same time.

Says Thewalt: "A classical 1/0 bit can be thought of as a person being either at the North or South Pole, whereas a qubit can be anywhere on the surface of the globe -- its actual state is described by two parameters similar to latitude and longitude."

Make a practical quantum computer with enough qubits available and it could complete in minutes calculations that would take today's super-computers years, and your laptop perhaps millions of years.

The work by Thewalt and his fellow researchers opens up yet another avenue of research and application that may, in time, lead to practical breakthroughs in quantum computing.

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Blood Mystery Solved: Two New Blood Types Identified

Blood Mystery Solved: Two New Blood Types Identified

  10:20:00 AM    Science Lover

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You probably know your blood type: A, B, AB or O. You may even know if you're Rhesus positive or negative. But how about the Langereis blood type? Or the Junior blood type? Positive or negative? Most people have never even heard of these.

Blood samples. You probably know your blood type: A, B, 
AB or O. You may even know if you're Rhesus positive or 
negative. But how about the Langereis blood type? Or the 
Junior blood type? Positive or negative? Most people have 
never even heard of these. (Credit: © weim / Fotolia)

Yet this knowledge could be "a matter of life and death," says University of Vermont biologist Bryan Ballif.

While blood transfusion problems due to Langereis and Junior blood types are rare worldwide, several ethnic populations are at risk, Ballif notes. "More than 50,000 Japanese are thought to be Junior negative and may encounter blood transfusion problems or mother-fetus incompatibility," he writes.

But the molecular basis of these two blood types has remained a mystery -- until now.

In the February issue of Nature Genetics, Ballif and his colleagues report on their discovery of two proteins on red blood cells responsible for these lesser-known blood types.

Ballif identified the two molecules as specialized transport proteins named ABCB6 and ABCG2.

"Only 30 proteins have previously been identified as responsible for a basic blood type," Ballif notes, "but the count now reaches 32."

The last new blood group proteins to be discovered were nearly a decade ago, Ballif says, "so it's pretty remarkable to have two identified this year."

Both of the newly identified proteins are also associated with anticancer drug resistance, so the findings may also have implications for improved treatment of breast and other cancers.

As part of the international effort, Ballif, assistant professor in the biology department, used a mass spectrometer at UVM funded by the Vermont Genetics Network. With this machine, he analyzed proteins purified by his longtime collaborator, Lionel Arnaud at the French National Institute for Blood Transfusion in Paris, France.

Ballif and Arnaud, in turn, relied on antibodies to Langereis and Junior blood antigens developed by Yoshihiko Tani at the Japanese Red Cross Osaka Blood Center and Toru Miyasaki at the Japanese Red Cross Hokkaido Blood Center.

After the protein identification in Vermont, the work returned to France. There Arnaud and his team conducted cellular and genetic tests confirming that these proteins were responsible for the Langereis and Junior blood types. "He was able to test the gene sequence," Ballif says, "and, sure enough, we found mutations in this particular gene for all the people in our sample who have these problems."

Transfusion troubles

Beyond the ABO blood type and the Rhesus (Rh) blood type, the International Blood Transfusion Society recognizes twenty-eight additional blood types with names like Duffy, Kidd, Diego and Lutheran. But Langereis and Junior have not been on this list. Although the antigens for the Junior and Langereis (or Lan) blood types were identified decades ago in pregnant women having difficulties carrying babies with incompatible blood types, the genetic basis of these antigens has been unknown until now.

Therefore, "very few people learn if they are Langereis or Junior positive or negative," Ballif says.

"Transfusion support of individuals with an anti-Lan antibody is highly challenging," the research team wrote in Nature Genetics, "partly because of the scarcity of compatible blood donors but mainly because of the lack of reliable reagents for blood screening." And Junior-negative blood donors are extremely rare too. That may soon change.

With the findings from this new research, health care professionals will now be able to more rapidly and confidently screen for these novel blood group proteins, Ballif wrote in a recent news article. "This will leave them better prepared to have blood ready when blood transfusions or other tissue donations are required," he notes.

"Now that we know these proteins, it will become a routine test," he says.

A better match

This science may be especially important to organ transplant patients. "As we get better and better at transplants, we do everything we can to make a good match," Ballif says. But sometimes a tissue or organ transplant, that looked like a good match, doesn't work -- and the donated tissue is rejected, which can lead to many problems or death.

"We don't always know why there is rejection," Ballif says, "but it may have to do with these proteins."

The rejection of donated tissue or blood is caused by the way the immune system distinguishes self from not-self. "If our own blood cells don't have these proteins, they're not familiar to our immune system," Ballif says, so the new blood doesn't "look like self" to the complex cellular defenses of the immune system. "They'll develop antibodies against it," Ballif says, and try to kill off the perceived invaders. In short, the body starts to attack itself.

"Then you may be out of luck," says Ballif, who notes that in addition to certain Japanese populations, European Gypsies are also at higher risk for not carrying the Langereis and Junior blood type proteins.

"There are people in the United States who have these challenges too," he says, "but it's more rare."

Other proteins

Ballif and his international colleagues are not done with their search. "We're following up on more unknown blood types," he says. "There are probably on the order of 10 to 15 more of these unknown blood type systems -- where we know there is a problem but we don't know what the protein is that is causing the problem."

Although these other blood systems are very rare, "if you're that one individual, and you need a transfusion," Ballif says, "there's nothing more important for you to know."

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The Law of Online Sharing

The Law of Online Sharing

  10:21:00 AM    Science Lover

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Facebook's Mark Zuckerberg will eventually have to deal with the fact that all growth has limits.

Credit: Technology Review

The idea of limitless growth gives sleepless nights to environmentalists, but not to Facebook founder Mark Zuckerberg. He espouses a law of social sharing, which predicts that every year, for the foreseeable future, the amount of information you share on the Web will double.

That rule of thumb can be visualized mathematically as a rapidly growing exponential curve. More simply, our online social lives are set to get significantly busier. As for Facebook, more personal data means better ad targeting. If things work out, Zuckerberg's net worth will follow a similar trajectory to that described in his law of social sharing.

That law is said to be mathematically derived from data inside Facebook. In ambition, it is closely modeled on Moore's Law, which was conceived by the computer-processor pioneer Gordon Moore in 1965 and has been at work in every advance in computing since. Also an exponential curve, it states that every two years twice as many transistors can be fitted onto a chip of any given area for the same price, allowing processing power to get cheaper and more capable.

There's a hint of vanity in Zuckerberg's attempt to ape Moore. But it makes sense to try to describe the mechanisms that have raised Facebook and other social-Web companies to power. The Web defines our time and is being rapidly reshaped by social content—from dumb viral videos to earnest pleas on serious issues. Facebook's success has left older companies like Google scrambling to add social features to their own products. Zuckerberg's Law can help us understand such a sudden change of tack from a seemingly dominant company, just as Moore's Law has long been used to plan and explain new strategies and technologies.

Inasmuch as Facebook is the company most invested in ­Zuckerberg's Law, its every move can be understood as an effort to sustain the graceful upward curve of its founder's formula. The short-term prospects look good for Zuckerberg. The original Moore's Law is on his side; faster, cheaper computers and mobile devices have made sharing easier and allowed us to do it wherever we go. Just as important, we are willing to play along, embracing new features from Facebook and others that lead us to share things today that we wouldn't or couldn't have yesterday.

Facebook's most recent major product launch, last September, is clearly aimed at validating Zuckerberg's prophecy and may provide its first real test. An upgrade to the Open Graph platform that unleashed the now ubiquitous Like button onto the Web , it added a feature that allows apps and Web sites to automatically share your activity via Facebook as you go about your business. Users must first give a service permission to share automatically on their behalf. After that, frictionless sharing, as it has become known, makes sharing happen without your needing to click a Like button, or to even think about sharing. The most prominent early implementation was the music-streaming service Spotify, which can now automatically post on Facebook the details of every song you listen to. In the first two months of frictionless sharing, more than 1.5 billion "listens" were shared through Spotify and other music apps. News organizations like the Washington Post use the feature, making it possible for them to share every article a person reads on their sites or in a dedicated app. Frictionless sharing is also helping Facebook drag formerly offline activities onto the Web. An app for runners can now automatically post the time, distance, and path of a person's morning run.

Frictionless sharing sustains ­Zuckerberg's Law by automating what used to be a manual task, thus removing a brake on the rate at which we can share. It also shows that we are willing to compromise our previous positions on how much sharing is too much. Facebook introduced a form of automatic sharing four years ago with a feature called Beacon, but it retreated after a strong backlash from users. Beacon automatically shared purchases that Facebook members made through affiliated online retailers, such as eBay. Frictionless sharing reintroduces the same basic model with the difference that it is opt-in rather than opt-out. Carl ­Sjogreen, a computer scientist who is a product director overseeing Open Graph, says it hasn't elicited anything like the rage that met Beacon's debut. "Everyone has a different idea of what they want to share, and what they want to see," says Sjogreen. Moreover, judging by the number of Spotify updates from my Facebook friends, frictionless sharing is pretty popular.

Privacy concerns will surely arise again as Facebook and others become able to ingest and process more of our personal data. Yet our urge to share always seems to win out. The potential for GPS-equipped cell phones to become location trackers, should the government demand access to our data, has long concerned some people. A South Park episode last year even portrayed an evil caricature of Apple boss Steve Jobs standing before a wall-sized map labeled "Where Everybody in the World Is Right Now." Six months later, to a mostly positive reception, Apple debuted a new iPhone feature called Find My Friends, which encourages users to let Apple track their location and share it.

It's not hard to explain why we seem eager to do our bit to maintain the march of Zuckerberg's Law. Social sites are like Skinner boxes: we press the Like button and are rewarded with attention and interaction from our friends. It doesn't take long to get conditioned to that reward. Frictionless sharing can now push the lever for us day and night, in hopes of drawing even more attention from others.

Unfortunately for Zuckerberg and his law, not every part of that feedback loop can be so easily boosted. Frictionless sharing helps, but getting others to care is the bigger challenge. In 2009 a new social site called Blippy was launched; it connected with your credit card to create a Twitter-style online feed of everything you bought. That stream could be made public or shared with particular contacts. Blippy got a lot of press but not the wide adoption its cofounder Philip Kaplan had hoped for. "Most people thought Blippy's biggest challenge would be getting users to share their purchases," he says. "Turns out the hard part was getting users to look at other people's purchases. Getting people to share is a small hump. Getting them to obsess over the data—making it fun, interesting, or useful—is the big hump."

Sjogreen has that problem in his sights. He says he is working on ways to turn the impending flood of daily trivialities coming from frictionless sharing into something fun, interesting, and useful. Repackaging the raw information to make it more compelling to others is one tactic. "It's the patterns and anomalies that matter to us," he says. For example, if you notice that a friend just watched 23 episodes of Breaking Bad in a row, you may decide you should check out that show after all. Or if he sets a new personal record on his morning run, the app in the phone strapped to his arm could automatically tout it to friends. Perhaps Blippy would have thrived if it highlighted significant purchases like vacations, instead of simply blasting people with everything from grocery lists to fuel bills.

We can only guess at the effectiveness of Sjogreen's future tactics, but it is certain that they can sustain Zuckerberg's Law for only so long. Gordon Moore put it well in 2005 when reflecting on the success of his own law: "It can't continue forever. The nature of exponentials is that you push them out and eventually disaster happens."

Facebook's impending problem is that even if the company enables future pacemakers to share our every heartbeat, the company cannot automate caring—the most important part of the feedback loop that has driven the social Web's ascent. Nothing can support exponential growth for long. No matter how cleverly our friends' social output is summarized and highlighted for us, there are only so many hours in the day for us to express that we care. Today, the law of social sharing is a useful way to think about the rise of social computing, but eventually, reality will make it obsolete.

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Big Ecosystem Shifts from Climate Change

Big Ecosystem Shifts from Climate Change

  12:47:00 AM    Science Lover

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By 2100, global climate change will modify plant communities covering almost half of Earth's land surface and will drive the conversion of nearly 40 percent of land-based ecosystems from one major ecological community type -- such as forest, grassland or tundra -- toward another, according to a new NASA and university computer modeling study.

Predicted percentage of ecological landscape
being driven toward changes in plant species
as a result of projected human-induced climate
change by 2100. (Credit: NASA/JPL-Caltech)

Researchers from NASA's Jet Propulsion Laboratory and the California Institute of Technology in Pasadena, Calif., investigated how Earth's plant life is likely to react over the next three centuries as Earth's climate changes in response to rising levels of human-produced greenhouse gases. Study results are published in the journal Climatic Change.

The model projections paint a portrait of increasing ecological change and stress in Earth's biosphere, with many plant and animal species facing increasing competition for survival, as well as significant species turnover, as some species invade areas occupied by other species. Most of Earth's land that is not covered by ice or desert is projected to undergo at least a 30 percent change in plant cover -- changes that will require humans and animals to adapt and often relocate.

In addition to altering plant communities, the study predicts climate change will disrupt the ecological balance between interdependent and often endangered plant and animal species, reduce biodiversity and adversely affect Earth's water, energy, carbon and other element cycles.

"For more than 25 years, scientists have warned of the dangers of human-induced climate change," said Jon Bergengren, a scientist who led the study while a postdoctoral scholar at Caltech. "Our study introduces a new view of climate change, exploring the ecological implications of a few degrees of global warming. While warnings of melting glaciers, rising sea levels and other environmental changes are illustrative and important, ultimately, it's the ecological consequences that matter most."

When faced with climate change, plant species often must "migrate" over multiple generations, as they can only survive, compete and reproduce within the range of climates to which they are evolutionarily and physiologically adapted. While Earth's plants and animals have evolved to migrate in response to seasonal environmental changes and to even larger transitions, such as the end of the last ice age, they often are not equipped to keep up with the rapidity of modern climate changes that are currently taking place. Human activities, such as agriculture and urbanization, are increasingly destroying Earth's natural habitats, and frequently block plants and animals from successfully migrating.

To study the sensitivity of Earth's ecological systems to climate change, the scientists used a computer model that predicts the type of plant community that is uniquely adapted to any climate on Earth. This model was used to simulate the future state of Earth's natural vegetation in harmony with climate projections from 10 different global climate simulations. These simulations are based on the intermediate greenhouse gas scenario in the United Nations' Intergovernmental Panel on Climate Change Fourth Assessment Report. That scenario assumes greenhouse gas levels will double by 2100 and then level off. The U.N. report's climate simulations predict a warmer and wetter Earth, with global temperature increases of 3.6 to 7.2 degrees Fahrenheit (2 to 4 degrees Celsius) by 2100, about the same warming that occurred following the Last Glacial Maximum almost 20,000 years ago, except about 100 times faster. Under the scenario, some regions become wetter because of enhanced evaporation, while others become drier due to changes in atmospheric circulation.

The researchers found a shift of biomes, or major ecological community types, toward Earth's poles -- most dramatically in temperate grasslands and boreal forests -- and toward higher elevations. Ecologically sensitive "hotspots" -- areas projected to undergo the greatest degree of species turnover -- that were identified by the study include regions in the Himalayas and the Tibetan Plateau, eastern equatorial Africa, Madagascar, the Mediterranean region, southern South America, and North America's Great Lakes and Great Plains areas. The largest areas of ecological sensitivity and biome changes predicted for this century are, not surprisingly, found in areas with the most dramatic climate change: in the Northern Hemisphere high latitudes, particularly along the northern and southern boundaries of boreal forests.

"Our study developed a simple, consistent and quantitative way to characterize the impacts of climate change on ecosystems, while assessing and comparing the implications of climate model projections," said JPL co-author Duane Waliser. "This new tool enables scientists to explore and understand interrelationships between Earth's ecosystems and climate and to identify regions projected to have the greatest degree of ecological sensitivity."

"In this study, we have developed and applied two new ecological sensitivity metrics -- analogs of climate sensitivity -- to investigate the potential degree of plant community changes over the next three centuries," said Bergengren. "The surprising degree of ecological sensitivity of Earth's ecosystems predicted by our research highlights the global imperative to accelerate progress toward preserving biodiversity by stabilizing Earth's climate."

JPL is managed for NASA by the California Institute of Technology in Pasadena.

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Diseased hearts to heal themselves in future

Diseased hearts to heal themselves in future

  10:08:00 AM    Science Lover

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Cellular reversion processes arise in diseases of the heart muscle, for example myocardial infarction and cardiomyopathy, which limit the fatal consequences for the organ. Scientists from the Max Planck Institute for Heart and Lung Research in Bad Nauheim and the Schüchtermann Klinik in Bad Rothenfelde have identified a protein which fulfils a central task in this reversion process by stimulating the regression of individual heart muscle cells into their precursor cells. It is now planned to improve the self-healing powers of the heart with the help of this protein.

Cellular regression in diseased heart tissue with the help
of oncostatin M: The image shows heart muscles under
the fluorescence microscope. The myofibrils are stained
red, the cell nuclei blue.
Credit: MPI for Heart and Lung Research

In order to regenerate damaged heart muscle as caused by a heart attack, for example, the damaged muscle cells must be replaced by new ones. The number of cells to be replaced may be considerable, depending on the extent of the damage caused. Simpler vertebrates like the salamander adopt a strategy whereby surviving healthy heart muscle cells regress into an embryonic state. This process, which is known as dedifferentiation, produces cells which contain a series of stem cell markers and re-attain their cell division activity. Thus, new cells are produced which convert, in turn, into heart muscle cells. The cardiac function is then restored through the remodelling of the muscle tissue.

An optimised repair mechanism of this kind does not exist in humans. Although heart stem cells were discovered some time ago, exactly how and to what extent they play a role in cardiac repair is a matter of dispute. It has only been known for a few years that processes comparable to those found in the salamander even exist in mammals.

Thomas Braun's research group at the Max Planck Institute for Heart and Lung Research in Bad Nauheim has now discovered the molecule responsible for controlling this dedifferentiation of heart muscle cells in mammals. The scientists initially noticed the high concentration of oncostatin M in tissue samples from the hearts of patients suffering from myocardial infarction. It was already known that this protein is responsible for the dedifferentiation of different cell types, among other things. The researchers therefore treated cultivated heart muscle cells with oncostatin M in the laboratory and were then able to trace the regression of the cells live under the microscope: "Based on certain changes in the cells, we were able to see that almost all heart muscle cells had been dedifferentiated within six days of treatment with oncostatin M," explains Braun. "We were also able to demonstrate the presence of various stem cell markers in the cells. This should be understood as an indicator that these cells had been switched to a repair mode."

Using a mouse infarct model, the Max Planck researchers succeeded in demonstrating that oncostatin M actually does stimulate the repair of damaged heart muscle tissue as presumed. One of the two test groups had been modified genetically in advance to ensure that the oncostatin M could not have any effect in these animals. "The difference between the two groups was astonishing. Whereas in the group in which oncostatin M could take effect almost all animals were still alive after four weeks, 40 percent of the genetically modified mice had died from the effects of the infarction," says Braun. The reason for this was that oncostatin M ensured clearly quantifiable better cardiac function in the unmodified animals.

The scientists in Bad Nauheim would now like to find a way of using oncostatin M in treatment. The aim is to strengthen the self-healing powers of the damaged heart muscle and to enable the restoration of cardiac function for the first time. The downside, however, is that oncostatin M was also observed to be counterproductive and exacerbated the damage in an experiment on a chronically diseased heart. "We believe that oncostatin M has considerable potential for efficiently healing damaged heart muscle tissue. What we now need is to be able to pinpoint the precise window of application to prevent any possible negative effects," says Braun.
More information: Thomas Kubin, Jochen Pöling, Sawa Kostin, Praveen Gajawada, Stefan Hein, Wolfgang Rees, Astrid Wietelmann, Minoru Tanaka, Holger Lörchner, Silvia Schimanski, Marten Szibor, Henning Warnecke, Thomas Braun: Oncostatin M Is a Major Mediator of Cardiomyocyte Dedifferentiation and Remodeling. Cell Stem Cell 9, 420, 2011

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Dark Matter of the Genome Revealed

Dark Matter of the Genome Revealed

  10:29:00 AM    Science Lover

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An international team of researchers has discovered the vast majority of the so-called "dark matter" in the human genome, by means of a sweeping comparison of 29 mammalian genomes. The team, led by scientists from the Broad Institute, has pinpointed the parts of the human genome that control when and where genes are turned on. This map is a critical step in interpreting the thousands of genetic changes that have been linked to human disease.

Rendering of DNA. Researchers have discovered the vast majority of the so-called "dark matter" in the human genome, by means of a sweeping comparison of 29 mammalian genomes. (Credit: iStockphoto/Martin McCarthy)

Their findings appear online October 12 in the journal Nature.

Early comparison studies of the human and mouse genomes led to the surprising discovery that the regulatory information that controls genes dwarfs the information in the genes themselves. But, these studies were indirect: they could infer the existence of these regulatory sequences, but could find only a small fraction of them. These mysterious sequences have been referred to as the dark matter of the genome, analogous to the unseen matter and energy that make up most of the universe.

This new study enlisted a menagerie of mammals -- including rabbit, bat, elephant, and more -- to reveal these mysterious genomic elements.

Over the last five years, the Broad Institute, the Genome Institute at Washington University, and the Baylor College of Medicine Human Genome Sequencing Center have sequenced the genomes of 29 placental mammals. The research team compared all of these genomes, 20 of which are first reported in this paper, looking for regions that remained largely unchanged across species.

"With just a few species, we didn't have the power to pinpoint individual regions of regulatory control," said Manolis Kellis, last author of the study and associate professor of computer science at MIT. "This new map reveals almost 3 million previously undetectable elements in non-coding regions that have been carefully preserved across all mammals, and whose disruptions appear to be associated with human disease."

These findings could yield a deeper understanding of disease-focused studies, which look for genetic variants closely tied to disease.

"Most of the genetic variants associated with common diseases occur in non-protein coding regions of the genome. In these regions, it is often difficult to find the causal mutation," said first author Kerstin Lindblad-Toh, scientific director of vertebrate genome biology at the Broad and a professor in comparative genomics at Uppsala University, Sweden. "This catalog will make it easier to decipher the function of disease-related variation in the human genome."

This new map helps pinpoint those mutations that are likely responsible for disease, as they have been preserved across millions of years of evolution, but are commonly disrupted in individuals that suffer from a given disease. Knowing the causal mutations and their likely functions can then help uncover the underlying disease mechanisms and reveal potential drug targets.

The scientists were able to suggest possible functions for more than half of the 360 million DNA letters contained in the conserved elements, revealing the hidden meaning behind the As, Cs, Ts, and Gs. These revealed:

• Almost 4,000 previously undetected exons, or segments of DNA that code for protein
• 10,000 highly conserved elements that may be involved in how proteins are made
• More than 1,000 new families of RNA secondary structures with diverse roles in gene regulation
• 2.7 million predicted targets of transcription factors, proteins that control gene expression

"We can use this treasure trove of new elements to revisit disease association studies, focusing on those that disrupt conserved elements and trying to discern their likely functions," said Kellis. "Using a single genome, the language of DNA seems cryptic. When studied through the lens of evolution, words light up and gain meaning."

The researchers were also able to harness this collection of genomes to look back in time, across more than 100 million years of evolution, to uncover the fundamental changes that shaped mammalian adaptation to different environments and lifestyles. The researchers revealed specific proteins under rapid evolution, including some related to the immune system, taste perception, and cell division. They also uncovered hundreds of protein domains within genes that are evolving rapidly, some of which are related to bone remodeling and retinal functions.

"The comparison of mammalian genomes reveals the regulatory controls that are common across all mammals," said Eric Lander, director of the Broad Institute and the third corresponding author of the paper. "These evolutionary innovations were devised more than 100 million years ago and are still at work in the human population today."

In addition to finding the DNA controls that are common across all mammals, the comparison highlighted areas that have been changing rapidly only in the human and primate genomes. Researchers had previously uncovered two hundred of these regions, some of which are linked to brain and limb development. The expanded list -- which now includes more than 1,000 regions -- will give scientists new starting points for understanding human evolution.

The comparison of many complete genomes is beginning to offer a clear view of once indiscernible genomic regions, and with additional genomes, that resolution will only increase. "The power of this resource is that it continues to improve with the inclusion of more species," said Lindblad-Toh. "It's a very systematic and unbiased approach that will only become more powerful with the inclusion of additional genomes."

Other Broad researchers who contributed to this work include Manuel Garber, Or Zuk, Michael F. Lin, Pouya Kheradpour, Jason Ernst, Evan Mauceli, Lucas D. Ward, Michele Clamp, Sante Gnerre, Jessica Alföldi, Jean Chang, Federica Di Palma, Mitchell Guttman, David B. Jaffe, Irwin Jungreis, Marcia Lara, Jim Robinson, Xiaohui Xie, Michael C. Zody, and members of the Broad Institute Sequencing Platform and Whole Genome Assembly Team.

This project was supported by the National Human Genome Research Institute, National Institute for General Medicine, the European Science Foundation, National Science Foundation, the Sloan Foundation, an Erwin Schrödinger Fellowship, the Gates Cambridge Trust, Novo Nordisk Foundation, University of Copenhagen, the David and Lucile Packard Foundation, the Danish Council for Independent Research Medical Sciences, and The Lundbeck Foundation.

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Paralyzed man uses mind-powered robot arm to touch

Paralyzed man uses mind-powered robot arm to touch

  2:11:00 AM    Science Lover

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Giving a high-five. Rubbing his girlfriend's hand. Such ordinary acts - but a milestone for a paralyzed man.

True, a robotic arm parked next to his wheelchair did the touching, painstakingly, palm to palm. But Tim Hemmes made that arm move just by thinking about it.

Emotions surged. For the first time in the seven years since a motorcycle accident left him a quadriplegic, Hemmes was reaching out to someone - even if it was only temporary, part of a monthlong science experiment at the University of Pittsburgh.

"It wasn't my arm but it was my brain, my thoughts. I was moving something," Hemmes says. "I don't have one single word to give you what I felt at that moment. That word doesn't exist."

The Pennsylvania man is among the pioneers in an ambitious quest for thought-controlled prosthetics to give the paralyzed more independence - the ability to feed themselves, turn a doorknob, hug a loved one.

The goal is a Star Trek-like melding of mind and machine, combining what's considered the most humanlike bionic arm to date - even the fingers bend like real ones - with tiny chips implanted in the brain. Those electrodes tap into electrical signals from brain cells that command movement. Bypassing a broken spinal cord, they relay those signals to the robotic third arm.
This research is years away from commercial use, but numerous teams are investigating different methods.

At Pittsburgh, monkeys learned to feed themselves marshmallows by thinking a robot arm into motion. At Duke University, monkeys used their thoughts to move virtual arms on a computer and got feedback that let them distinguish the texture of what they "touched."

Through a project known as BrainGate and other research, a few paralyzed people outfitted with brain electrodes have used their minds to work computers, even make simple movements with prosthetic arms.

But can these neuroprosthetics ever offer the complex, rapid movements that people would need for more practical, everyday use?

"We really are at a tipping point now with this technology," says Michael McLoughlin of the Johns Hopkins University Applied Physics Laboratory, which developed the humanlike arm in a $100 million project for DARPA, the Pentagon's research agency.

Pittsburgh is helping to lead a closely watched series of government-funded studies over the next two years to try to find out. A handful of quadriplegic volunteers will train their brains to operate the DARPA arm in increasingly sophisticated ways, even using sensors implanted in its fingertips to try to feel what they touch, while scientists explore which electrodes work best.

"Imagine all the joints that are in your hand. There's 20 motions around all those joints," says Pittsburgh neurobiologist Andrew Schwartz. "It's not just reaching out and crudely grasping something. We want them to be able to use the fingers we've worked so hard on."

The 30-year-old Hemmes' task was a much simpler first step. He was testing whether a new type of chip, which for safety reasons the Food and Drug Administration let stay on this initial volunteer's brain for just a month, could allow for three-dimensional arm movement.

He surprised researchers the day before the electrodes were removed. The robotic arm whirred as Hemmes' mind pushed it forward to hesitantly tap palms with a scientist. Then his girlfriend beckoned. The room abruptly hushed. Hemmes painstakingly raised the black metal hand again and slowly rubbed its palm against hers a few times.

These emotional robotic touches have inspired researchers now recruiting volunteers for soon-to-start yearlong experiments.

"It was awesome," is the decidedly unscientific description from the normally reserved Dr. Michael Boninger, rehabilitation chief at the University of Pittsburgh Medical Center. "To interact with a human that way. ... This is the beginning."

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Hemmes' journey began in 2004. He owned an auto-detailing shop and rode his motorcycle in his spare time. Then one summer evening he swerved to miss a deer. His bike struck a guardrail. His neck snapped.

His determination didn't. Paralyzed below the shoulders, he's tried other experimental procedures in hopes, so far unrealized, of regaining some arm function.

"I always tell people your legs are great ... but they just get you from here to there," Hemmes says as his caregiver waits to feed him a bite of a cheeseburger near his home in Butler, north of Pittsburgh. "Your arms and fingers and hands do everything else. I have to get those back, I absolutely have to."

His ultimate goal is to hug his 8-year-old daughter. "I'm going to do whatever it takes, as long as it takes, to do that again."

Hemmes entered an operating room at UPMC with a mix of nerves and excitement.

"It's good anxiety," he says. "There is so much riding on this."

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Think "I want that apple," and your arm reaches out and grasps it. You're not aware that neurons are instantaneously firing in patterns that send commands down the spinal cord - make the shoulder raise the arm, extend the elbow, flex the wrist and all five fingers.

A very similar firing occurs when you imagine movement or watch the movement you'd like to perform, explains Boninger, who with Schwartz is leading the Pittsburgh research together with a team of bioengineers, neuroscientists and physicians.

The DARPA arm was developed primarily for amputees. Separate research is under way to help them move it by using transplanted nerves to sense those brain commands. The paralyzed pose a more difficult challenge: getting those signals around a broken spinal cord.

For quadriplegic patients, scientists use implanted electrodes, called a "brain-computer interface" or BCI, to record that electrical activity. The signals move down through wires that tunnel under the skin and out by the collarbone, and are plugged into a computer or a robotic arm.

Until now, researchers mostly have tested miniature electrodes that poke inside the brain's motor cortex and record from individual cells, presumably allowing for precise movements. Pittsburgh's next test-patient will have two penetrating grids implanted in different parts of the cortex for a year to record from 200 cells altogether.

In contrast, Hemmes' chip sat on the surface of his motor cortex, a less invasive method that records from groups of cells. The size of two postage stamps, it's based on a kind of electrical signal mapping used to track seizures in epilepsy patients.

Both approaches need study, says Daofen Chen of the National Institutes of Health, who oversees neurorehabilitation research. He compares the options to eavesdropping on a party by sending in individual microphones or setting up a recorder at the window.

Boninger adds that scar tissue can blunt the penetrating electrodes over time, and the surface chips may be easier to convert to a wireless system, which is important for commercial use.

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Hemmes' operation took two hours. He had practiced imagining arm movements inside brain scanners, to see where the electrical signals concentrated. That's where neurosurgeon Elizabeth Tyler-Kabara cut, attaching the chip through an inch-wide opening on the left side of Hemmes' skull.

Two days later, Hemmes was hooked to a computer, beginning simple cursor movements. The next week, it was time to test if he could trigger real-life movement using the DARPA arm.

Hemmes reclined in his wheelchair, the robot arm bolted to a steel rod nearby. The task: make the arm reach out to grasp a ball mounted on a board.

The arm whirs forward, then stops, then goes again, then suddenly pulls back.

"It's doing the opposite of what I ask it do," Hemmes says in frustration. "When I think about reaching back, it goes forward."

Dr. Wei Wang, a member of the research team, watches Hemmes' brain patterns on a nearby computer screen, trying to match them to the robotic movements. Focus on your elbow, Wang advises.

Hemmes takes a deep breath and tries. The arm whirs forward this time, reaching the ball. The fingers clench around it.

"There's no owner's manual," Hemmes says, thrilled that the back-and-forth pays off. "I'm training my brain to figure how to do all this."

Letting go is harder, the motor growling as the arm tugs backward before the fingers fully release. Hemmes starts imagining his hand relaxing before pulling backward, and the robot hand follows.

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Sure, a robotic hand that one day mounts to a wheelchair could be useful. But no matter how well today's prosthetics move, they've got a problem: They don't sense what they touch. Normally, instant messages flash from the skin up to the brain to say "squeeze tighter" so we don't drop that coffee cup, or "tight enough" so we don't hug too hard.

Besides, Hemmes shares the dream of many quadriplegics. He doesn't want a bionic third hand. He wants to move his own hands again.

"These are all scientific goals that are very real," Boninger says.

Recreating sensation means crafting a two-way highway with those brain chips. That's what Duke University, in a study published last week in the journal Nature, did with its two monkeys. When the animals "touched" objects on a computer screen with their video game-like arms, electrical signals flashed back up to implanted electrodes - different signals for different textures, to tell the objects apart.

Sensors in the DARPA arm's fingertips allow for that same kind of feedback. McLoughlin says the plan is for one of the Pittsburgh study patients to begin testing touch capability next year, with a similar attempt at the California Institute of Technology to follow.

What about moving paralyzed limbs? Duke's plan is to turn its research into a robotic exoskeleton that would help the paralyzed move their bodies.

Hemmes is more intrigued by what's called functional electrical stimulation, zapping muscles with electrical currents to make them move. At Hemmes' request, Boninger's team attempted to fit his hand with a stimulator glove that might be linked to his electrode, but it was unsuccessful. The NIH's Chen says still other researchers are working on that kind of approach.

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Hemmes likened moving the DARPA arm to learning to drive a car with a manual transmission. It took practice, but by week four he was moving the arm sideways as well as back and forth.

The fingers still clenched pretty tight, though. So when his girlfriend Katie Schaffer spoke up - "I want to hold your hand," she said on his last day of testing - Hemmes didn't dare bend them.

The two met after his accident, so he'd never before reached out to her.

"I was just trying to be gentle. I didn't want to hurt her, and I finally got there," Hemmes says. "Definitely the tears were flowing."

He says he was ready for a break after almost daily scientific testing, so removing the electrode and wires the next day wasn't a disappointment. He's confident the researchers will call him back once the technology advances.

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