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New Computer Vision System: "Nope. She's Faking It"

A new computerized system is better than humans at telling a genuine expression of pain from a fake one.

Researchers who developed the system say it could be used to detect when someone is feigning illness or pain to escape work. It could also spot attempts to minimize or mask pain, which could be useful during, say, interrogations or health assessments.

According to a report in Wired, the new system is based on something called the Facial Action Coding System, developed by psychologist Paul Eckman. The system is used by animators to give their computerized characters realistic human expressions. The idea is that any facial expression can be mapped to a specific group of muscles in the face.

When people attempt to fake pain, they use the exact same facial muscles that are contracted during real pain. What distinguishes a deliberate expression from a spontaneous one is the dynamics: things like when, how much, and how quickly the muscles move. Humans, it turns out, aren’t great at picking up on this subtle difference in the dynamics of facial motion.

To test this, researchers at the University of California at San Diego and the University of Toronto first recorded videos of volunteers’ facial expressions as they experienced real pain by dipping their arm in icy water and also as they faked pain while putting their arm in warm water. Then the researchers showed the videos to 170 people and asked them tell real pain expressions from fake ones. The observers could only guess correctly about half the time. With training, their accuracy went up to only 55 percent.

The researchers’ computer vision and machine learning system, on the other hand, was much better at spotting the difference in the dynamics of muscle movement. It could distinguish between real and fake expressions with 85 percent accuracy.

The study, which was published today in the journal Current Biology, shows that the single most predictive feature of fake expressions is the mouth, and how and when it opens. The researchers found that when people fake pain, their mouth-opening action during grimaces is too regular. Both the interval between mouth opening and the time for which they open their mouth is too consistent.

In a press release, Marian Bartlett, research professor at UC San Diego's Institute for Neural Computation and an author of the study, said: "Our computer-vision system can be applied to detect states in which the human face may provide important clues as to health, physiology, emotion, or thought, such as drivers' expressions of sleepiness, students' expressions of attention and comprehension of lectures, or responses to treatment of affective disorders."

A Transistor that Stands Up to Blistering Nuclear Reactor Temperatures

Wonderful as silicon-based transistors are, they break down at temperatures above 350 °C. For higher-temperature environments, such as those found in jet engines and deep oil wells, researchers have had to turn to other options such as silicon carbide circuits, which can survive up to 550 °C.

Now, researchers at the University of Utah have made tiny plasma-based transistors that work at the blistering temperatures found inside nuclear reactors. While plasma transistors were first reported five years ago, the new devices are 500 times smaller than those early versions.

The new micro-plasma transistors work at temperatures of up to 790 °C. They could be used to make electronics for controlling robots that conduct tasks inside a nuclear reactor, says Massood Tabib-Azar, the professor of electrical and computer engineering at the University of Utah who developed the  devices. Such extreme-temperature logic circuits could also control nuclear reactors in case of emergencies or nuclear attacks. Tabib-Azar and his postdoctoral researcher, Pradeep Pai, reported the plasma transistors online today in the journal IEEE Electron Device Letters.

In a conventional three-terminal field-effect transistor, the voltage applied at the gate terminal controls the current flowing through a semiconductor channel. A voltage that is above a certain threshold turns the device on.

The channel in a plasma transistor consists of a partially ionized gas, or plasma, instead of a semiconductor. An electron emitter, typically silicon, injects electrons into the plasma when a voltage is applied to it. Plasmas are generated at very high temperatures, making them suitable for an extreme-environment transistor. Today’s plasma transistors, which are used in light sources and medical instruments, are about 500 micrometers long and operate at more than 300 volts, requiring special high-voltage sources.

The new devices are between 1 and 6 microns in length and operate at one-sixth the voltage. Tabib-Azar and Pai made the transistors by first depositing layers of a metal alloy to form the gate on a 10-centimeter glass wafer. They deposited a thin layer of silicon on top of the gate. Then they etched away portions of the silicon film using a chemically reactive gas, creating cavities and empty spaces that they could fill with the plasma to form the transistor's channel. They used helium as the plasma source.

The researchers are working on connecting the devices to make logic circuits that they plan to test in the experimental nuclear reactor at the University of Utah.

In addition to working in nuclear reactors, the new extreme-temperature transistors could be used to generate X-rays. Instead of using bulky lenses and X-ray shaping devices, engineers could use these tiny devices to pattern microscale devices in silicon. Or this type of transistor could be incorporated in a smartphone, creating an X-ray imaging source to collect images of wounded soldiers in the battlefield, says Tabib-Azar.

Photo: Dan Hixson/University of Utah

Academic Inventions Funded by Industry Benefit Innovation

Industry money in university labs can raise eyebrows among researchers who worry that corporate interests might hoard academic inventions through exclusive licensing deals and stifle broader innovation. But a new study based on two decades of evidence from the University of California system suggests such fears surrounding industry-funded university research may be overblown.

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Laser Makes More Accurate Radar System

Using a laser to generate radio-frequency radar pulses, a group of researchers has demonstrated a radar system that they say can be smaller, more efficient, and more accurate than anything available today.

The work could make it easier for radar systems to use software-defined radio, which allows users to rapidly change the signal they generate using software rather than analog hardware components such as mixers, amplifiers, and the like. Dispensing with these electronic components would make radars smaller, lighter, and more energy efficient, making them attractive for use aboard airplanes and in remote locations. They could even be switched on the fly from acting as radars to working as communications devices, says Paolo Ghelfi, an optical communications researcher at the National Inter-University Consortium for Telecommunications in Pisa, Italy. Ghelfi, head of research Antonella Bogoni, and their colleagues describe their photonics-based, fully-digital radar system, PHODIR, in this week’s issue of Nature.

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IBM Watson Takes on the Genetics of Brain Cancer

Twenty patients with an aggressive form of brain cancer will have a new doctor on their medical team: the learned geneticist known as IBM Watson. In a collaboration announced today between IBM and the New York Genome Center, IBM's Jeopardy-beating AI will analyze the genomes of those 20 patients in hopes of providing insights for their oncologists. 

IBM has been promoting its AI as a killer app for health care, thanks to Watson's natural language processing skills and machine learning abilities. Over the past two years Watson has been engaged in a separate project at New York's Memorial Sloan-Kettering Cancer Center, in which doctors are training the AI to understand the language of medicine. In that project, Watson is being taught to read patients' records and search the medical literature for relevant suggestions on treatment. 

This new project will show that Watson can provide deeper analysis for such point-of-care applications, said IBM Research's Raminderpal Singh after a press conference in New York today. For these 20 cancer patients, Watson won't just scan the medical literature for information. The AI will also scan the genetic data from the patients' own healthy cells and cancer cells, and will then search for information that's relevant to the genetic mutations in the tumor. "As genome sequencing becomes more commonplace—and it will—we'll need a way to go from mutation information to clinically actionable information," said Singh.   

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The Earth Was Lucky to Dodge a Massive Solar Magnetic Storm in 2012

When the largest magnetic storm ever recorded struck Earth in 1859, telegraph systems failed across North America and Europe and gave electric shocks to some telegraph operators. Researchers recently analyzed a similarly huge magnetic storm that missed Earth by just nine days in 2012, which could have caused trillions of dollars worth of damages to satellites and power grids.

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Dean Kamen to Tech Community: "We're Not Creating Enough Innovators"

Dean Kamen, the celebrated inventor and entrepreneur and tireless advocate for science and technology, had a clear message for his audience at the South By Southwest (SXSW) festival in Austin last week: The tech community needs to work harder to attract more young people to careers in technology and engineering. “We’re not creating enough innovators,” he said.

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Scientists Must Stop Confusing Batteries and Supercapacitors, Argue Experts

What’s in a name? More than you'd care to think about when it comes to energy storage, a team of researchers from France and the United States argued last week in the journal Science. As the energy storage field has taken off in the past five to seven years, the line between batteries and supercapacitors (also called ultracapacitors) has started to blur and scientists and engineers have become less and less consistent when naming these devices, the researchers say.

Much too often, battery materials are called supercapacitors in the scientific literature, unknowingly or perhaps deliberately, says Yury Gogotsi, a materials science and engineering professor at Drexel University and one of the authors of an essay in last week's Science. “Confusion doesn’t help progress,” he says. “Attempts to sell a poor material as a good one by using wrong terminology really holds back research and leads to a waste of money and time.”

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How Do You See Gravitational Waves?

On Monday, a team of astronomers announced some very big, potentially Nobel Prize-winning news: the first sighting of gravitational waves that filled the very early universe. 

The detection, which was made by the BICEP2 experiment in Antarctica, still needs to be confirmed by other experiments. But if it is, the signal could provide a window into "inflation"—a brief but explosive period when the universe is thought to have ballooned enormously in size. "This is literally a window back to almost the beginning of time itself," physicist Lawrence Krauss told Wired magazine.  

As a technology-minded physics buff, I inevitably wind up asking two very basic questions whenever a long-sought discovery takes place. First, why didn't we see this before? And, second, why are we seeing it now?

The answer to the first question is pretty much what you'd expect: the signal is quite hard to see. Like a number of ongoing experiments, BICEP2 hunted for evidence of primordial gravitational waves in the cosmic microwave background (CMB), a haze of light that was given off when the universe was just 380 000 years old. After some 13.8 billion years of cosmic expansion, the wavelength of this relic radiation has been stretched so that the photons now reaching Earth sit in the microwave band of the electromagnetic spectrum.

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Bionically Enhanced Chloroplasts Boost Photosynthesis and Spawn a New Field

Consider for a moment the magical work done by chloroplasts. These are the plant organelles that absorb light from the sun, convert it into chemical energy and ultimately use it as a building block for synthesizing glucose, the primary source of fuel for both plants and animals. While their achievement has the appearance of alchemy, like every other organelle, these chloroplasts are but little machines. Now, it seems they're due for an upgrade.

In a paper published yesterday in the journal Nature Materials, chemical engineers at the Massachusetts Institute of Technology report that when injected with single-walled carbon nanotubes (SWNTs), chloroplasts can be coaxed to photosynthesize more efficiently than normal.

The first phase of photosynthesis, referred to commonly as the "light reactions," involves excitation of pigments and the subsequent transport of electrons between multiple photosystems. The researchers used this flow of electrons as a measurement for the rate of photosynthesis and found that when the nanotubes were present the flow increased by 49 percent.

Chlorophyll, the pigment normally found in chloroplasts, can only absorb a small fraction of the light entering a plant, most of which resides in the 400 to 500-nanometer and 600 to 700-nanometer range. Although the researchers cannot yet offer an explanation for why carbon nanotubes would enhance the efficiency of chloroplasts, the team theorizes that it may be due to a broadening of this range. SWNTs are known to absorb light in the ultraviolet, visible, and near-infrared spectra.

The MIT engineers write:

"Improving photosynthetic efficiency may require extending the range of solar light absorption, particularly in the near-infrared spectral range, which is able to penetrate deeper into living organisms."

They report having the most success with chloroplasts that had been removed from the plant. Under these circumstances, they were able to inject the nanotubes directly into the organelle. 

In a separate experiment, the researchers sought to find a way to deliver nanotubes into a living plant. In order to do this, they developed a new technique called lipid exchange envelope penetration. Basically, they applied the nanotubes to underside of the leaf via a watery solution which is absorbed through tiny pores called stomata. The transfer across the fatty membrane of the chloroplast was made possible by coating the carbon nanotubes in negatively charged DNA.

When they introduced machinery into a living plant in this way, the chloroplasts received slightly less of a boost, photosynthesizing only 30 percent more efficiently than normal. But this delivery technique may itself be counted as a breakthrough.  

With it, the researchers have tried packing plant cells with particles that protect it from the damaging effects of light exposure, and with another type of carbon nanotube that has been shown to be sensitive to nitric oxide. With such techniques, chemical engineers may one day develop plants that function as pollution detectors. 

Indeed the researchers are arguing that their work establishes an entire new field of research, one they're calling plant nanobionics.


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