(Credit: iStockphoto)

Psychologists at the University of California, Santa Barbara have found evidence for the value of mind-wandering.

The researchers presented 145 undergraduate students with two “unusual uses” tasks that gave them two minutes to list as many uses as possible for everyday objects such as toothpicks, clothes hangers and bricks.

After the two minutes were over, participants were given a 12-minute break, during which they rested, undertook a demanding memory activity that required their full attention or engaged in an undemanding reaction-time activity known to elicit mind-wandering. A fourth group of students had no break. All participants were then given four unusual-uses tasks, including the two that they had completed earlier.

Those students who had done the undemanding activity performed an average of 41% better at the repeated tasks the second time they tried them. By contrast, students in the other three groups showed no improvement.

“We’ve traditionally found that rapid-eye-movement sleep grants creative insight. That allowing the mind to wander does the same is absolutely fascinating. I think they are on to something really interesting here,” says Sara Mednick, a psychologist at the University of California, Riverside.

Participants who engaged in the undemanding task did not do any better than others on unusual-uses tasks that they encountered for the first time in the second round. “The implication is that mind-wandering was only helpful for problems that were already being mentally chewed on. It didn’t seem to lead to a general increase in creative problem-solving ability,” says Baird.

The upside of zoning out

As well as revealing that breaks on their own do not encourage creative thinking, Baird’s work suggests an explanation for one of psychology’s great mysteries: why we zone out.

From an evolutionary perspective, mind-wandering seems totally counterproductive and has been viewed as dysfunctional because it compromises people’s performance in physical activities. However, Baird’s work shows that allowing the brain to enter this state when it is considering complex problems can have real benefits. Zoning out may have aided humans when survival depended on creative solutions.

“There is a real possibility that mind-wandering is so common because evolution has selected for it over time, but before we can come to that conclusion we have to ascertain whether it’s genetically determined,” says Kounios.

Ref.: Baird, B., et al., Psychological Science, in press

Transmission electron microscopy (TEM) images showing quantum dots after micelle encapsulation (Credit: Ling Ye, et al./Nature Nanotechnology)

A pioneering study to gauge the toxicity of quantum dots in primates has found the tiny luminescent crystals are safe over a one-year period, a hopeful outcome for doctors and scientists seeking new ways to battle diseases like cancer through nanomedicine.

In the study, scientists found that four rhesus monkeys injected with cadmium-selenide quantum dots remained in normal health over 90 days. Blood and biochemical markers stayed in typical ranges, and major organs developed no abnormalities. The animals didn’t lose weight. Two monkeys observed for an additional year also showed no signs of illness.

Quantum dots are tiny luminescent crystals that glow brightly in different colors. Medical researchers are eyeing the crystals for use in image-guided surgery, light-activated therapies and sensitive diagnostic tests. Cadmium selenide quantum dots are among the most studied, with potential applications not only in medicine, but as components of solar cells, quantum computers, light-emitting diodes and more.

The new toxicity study — completed by the University at Buffalo, the Chinese PLA General Hospital, China’s ChangChun University of Science and Technology, and Singapore’s Nanyang Technological University — begins to address the concern of health professionals who worry that quantum dots may be dangerous to humans.

The authors caution, however, that more research is needed to determine the nanocrystals’ long-term effects in primates; most of the potentially toxic cadmium from the quantum dots stayed in the liver, spleen and kidneys of the animals studied over the 90-day period.

“This is the first study that uses primates as animal models for in vivo studies with quantum dots,” said paper coauthor Paras Prasad, UB professor of chemistry and medicine, and executive director of UB’s Institute for Lasers, Photonics and Biophotonics (ILPB). “So far, such toxicity studies have focused only on mice and rats, but humans are very different from mice. More studies using animal models that are closer to humans are necessary.”

The cadmium build-up, in particular, is a serious concern that warrants further investigation, said Ken-Tye Yong, a Nanyang Technological University assistant professor who began working with Prasad on the study as a postdoctoral researcher at UB.

Because of that concern, the best in-vivo applications for cadmium-selenide quantum dots in medicine may be the ones that use the crystals in a limited capacity, said Mark Swihart, a third coauthor and a UB professor of chemical and biological engineering. Image-guided surgery, which could involve a single dose of quantum dots to identify a tumor or other target area, falls into this category.

Ref.: Ling Ye, et al. A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots. Nature Nanotechnology, 20 May 2012 DOI: 10.1038/nnano.2012.74

Polling current position and channel-state-information (CSI) (credit: Neil Mehta, Alexandra Duel-Hallen, Wenye Wang)

Researchers from North Carolina State University have devised a method to improve the quality and efficiency of data transmission in Mobile ad hoc networks (MANETs).

MANETs allow people in multiple, rapidly-moving vehicles to communicate with each other, such as in military or emergency-response situations.

“Our goal was to get the highest data rate possible, without compromising the fidelity of the signal,” says Dr. Alexandra Duel-Hallen, a professor of electrical and computer engineering at NC State and co-author of a paper describing the work.

Transmitting data within MANETs is challenging because every node that transmits and receives data is in motion — and the faster they are moving, the harder it is for the network to identify effective relay “paths” for transmitting data. This is because the power of the data-transmission channels fluctuates much more rapidly at high speed.

In other words, a transmitter may try to send a message through Relay A, because Relay A has a strong signal. However, because the transmitter and Relay A are both moving quickly, Relay A’s signal might be weak by the time the message actually gets there. And a weak signal could result in the message being garbled.

To address this issue, researchers developed a method to improve the ability of each node in the network to select the best path for relaying data, as well as the best for transmitting the data that ensures reliable reception.

When a node needs to transmit a message, it first measures the strength of transmissions it is receiving from potential relays. Those data are then plugged in to an algorithm that predicts which relay will be strongest when the message is transmitted.

By predicting the strength of the relay, the algorithm also tells the node the rate at which it should transmit the data. If it tries to send too much data too quickly, the data quality will suffer — the data could be compromised. If the rate of data transmission is too slow, the network won’t be operating at peak efficiency.

The research was supported by the National Science Foundation and the U.S. Army Research Office.

Ref.: Neil Mehta, Alexandra Duel-Hallen, Wenye Wang, Enabling Adaptive Rate and Relay Selection for 802.11 Mobile Ad Hoc Networks, presented at the IEEE’s International Conference on Communications in Ottawa, June 10-15, 2012

The Leap is a small iPod-sized USB peripheral that creates a 3D interaction space of 8 cubic feet to precisely interact with and control software on your laptop or desktop computer. (Credit: Leap Motion)

Leap Motion is unveiling its Leap 3D motion control system, Technology Review Hello World reports.

Leap Motion appears to outrank Kinect in terms of its capability. The technology, reports CNET, can detect motion with up to a hundredth of a millimeter accuracy; it’s nuanced enough to detect fingers, for instance, enabling the possibility of touch-free pinch-to-zoom.

When the device is available for commercial release, it’s expected to retail for around $70. The device itself is fairly simple — a small USB input device (plus an advanced software platform).

There’s a range of possibilities for the technology: consumers might use it to browse the web; engineers could mold virtual clay; designers could draw precisely in 2-D or 3-D; and new gaming possibilities could evolve.

Leap Motion is looking for a “few hundred” developers to get involved with their tech, and soon intend to send out as many as 20,000 free developer kits when it’s officially released — in 2013, according to reports.

Schematic of a silicon nanowire (gray) hooked up by two gold electrodes (yellow) (credit: Pengyu Fan et al./Nature Photonics)

Stanford University and the University of Pennsylvania engineers have used “plasmonic cloaking” to create a device that can see without being seen.

It is the first example of what the researchers describe as a new class of devices that control the flow of light at the nanoscale to produce both optical and electronic functions.

At the heart of the device are silicon nanowires covered by a thin cap of gold. By adjusting the ratio of metal to silicon — a technique the engineers refer to as tuning the geometries — they capitalize on favorable nanoscale physics in which the reflected light sources from the two materials cancel each other to make the device invisible.

Pengyu Fan, the lead author of a paper demonstrating the new device, is a doctoral candidate in materials science and engineering at Stanford University working in Professor Mark Brongersma’s group.

Cloak of invisiblity

Light detection is well known and relatively simple. Silicon generates electrical current when illuminated and is common in solar panels and light sensors today. The Stanford device, however, is a departure in that for the first time it uses a relatively new concept known as plasmonic cloaking to render the device invisible.

SEM image of a 50-nm-diameter silicon nanowire with a 20-nm-thick gold "cover" (credit: Pengyu Fan et al./Nature Photonics)

The field of plasmonics studies how light interacts with metal nanostructures and induces tiny oscillating electrical currents along the surfaces of the metal and the semiconductor. These currents, in turn, produce scattered light waves.

By carefully designing their device — by tuning the geometries — the engineers have created a plasmonic cloak in which the scattered light from the metal and semiconductor cancel each other perfectly through a phenomenon known as destructive interference.

The rippling light waves in the metal and semiconductor create a separation of positive and negative charges in the materials — a dipole moment, in technical terms. The key is to create a dipole in the gold that is equal in strength but opposite in sign to the dipole in the silicon. When equally strong positive and negative dipoles meet, they cancel each other and the system becomes invisible.

“We found that a carefully engineered gold shell dramatically alters the optical response of the silicon nanowire,” said Fan. “Light absorption in the wire drops slightly — by a factor of just four — but the scattering of light drops by 100 times due to the cloaking effect, becoming invisible.”

“It seems counterintuitive,” said Brongersma, “but you can cover a semiconductor with metal — even one as reflective as gold — and still have the light get through to the silicon. As we show, the metal not only allows the light to reach the silicon where we can detect the current generated, but it makes the wire invisible, too.”

Plasmonically cloaked pixels

The engineers have shown that plasmonic cloaking is effective across much of the visible spectrum of light and that the effect works regardless of the angle of incoming light or the shape and placement of the metal-covered nanowires in the device. They likewise demonstrate that other metals commonly used in computer chips, like aluminum and copper, work just as well as gold.

To produce invisibility, what matters above all is the tuning of metal and semiconductor.

“If the dipoles do not align properly, the cloaking effect is lessened, or even lost,” said Fan. “Having the right amount of materials at the nanoscale, therefore, is key to producing the greatest degree of cloaking.”

In the future, the engineers foresee application for such tunable, metal-semiconductor devices in many relevant areas, including solar cells, sensors, solid-state lighting, chip-scale lasers, and more.

In digital cameras and advanced imaging systems, for instance, plasmonically cloaked pixels might reduce the disruptive cross-talk between neighboring pixels that produces blur. It could therefore lead to sharper, more accurate photos and medical images.

“We can even imagine reengineering existing opto-electronic devices to incorporate valuable new functions and to achieve sensor densities not possible today,” concluded Brongersma. “There are many emerging opportunities for these photonic building blocks.”

Ref.: Pengyu Fan et al., An invisible metal–semiconductor photodetector, Nature Photonics, 2012, DOI: 10.1038/nphoton.2012.108

Under ultraviolet light, petri dishes containing cells glow red or green depending upon the orientation of a specific section of genetic code inside the cells' DNA. The section of DNA can be flipped back and forth using the RAD technique. (Credit: Stanford University)

A method for repeatedly encoding, storing and erasing digital data within the DNA of living cells, using natural enzymes adapted from bacteria — the genetic equivalent of a bit — has been developed by Stanford University scientists in the Department of Bioengineering, a joint effort of the School of Engineering and the School of Medicine.

“Programmable data storage within the DNA of living cells would seem an incredibly powerful tool for studying cancer, aging, organismal development and even the natural environment,” said Stanford assistant professor Drew Endy. Researchers could count how many times a cell divides, for instance, and that might someday give scientists the ability to turn off cells before they turn cancerous.

Non-volatile memory

Architecture, mechanisms, and operation of a recombinase addressable data (RAD) module. The DNA inversion RAD module is driven by two generic transcription input signals, set and reset. A set signal drives expression of integrase that inverts a DNA element serving as a genetic data register. Flipping the register converts flanking attB and attP sites to attL and attR sites, respectively. A reset signal drives expression of integrase and excisionase and restores both register orientation and the original flanking attB and attP sites. The register itself encodes a constitutive promoter which initiates strand-specific transcription. Following successful set or reset operations, mutually exclusive transcription outputs “1” or “0” are activated, respectively. For the RAD module developed here, a “1” or “0” register state produces red or green fluorescent protein, respectively. (Credit: Stanford University/PNAS)

In the computer world, their work would form the basis of what is known as non-volatile memory — data storage that can retain information without consuming power. In biotechnology, it is known as “recombinase-mediated DNA inversion,” after the enzymatic processes used to cut, flip and recombine DNA within the cell.

The team calls its device a “recombinase addressable data” module, or RAD for short. They used RAD to modify a particular section of DNA with microbes that determines how the one-celled organisms will fluoresce under ultraviolet light. The microbes glow red or green depending upon the orientation of the section of DNA. Using RAD, the engineers can flip the section back and forth at will.

To make their system work, the team had to control the precise dynamics of two opposing proteins, integrase and excisionase, within the microbes. “Previous work had shown how to flip the genetic sequence irreversibly — in one direction through the expression of a single enzyme,”  said Stanford postdoctoral scholar Jerome Bonnet, “but we needed to reliably flip the sequence back and forth, over and over, in order to create a fully reusable binary data register.”

The researchers found it was fairly easy to flip a section of DNA in either direction. “But we discovered time and again that most of our designs failed when the two proteins were used together within the same cell,” said Endy. “Ergo: Three years and 750 tries to get the balance of protein levels right.”

Going from bit to byte

Bonnet has now tested RAD modules in single microbes that have doubled more than 100 times and the switch has held. He has likewise switched the latch and watched a cell double 90 times, and set it back. The latch will even store information when the enzymes are not present. In short, RAD works. It is reliable and it is rewritable.

“One of the coolest places for computing,” Endy said, “is within biological systems.” His goal is to go from the single bit he has now to eight bits — or a “byte” — of programmable genetic data storage.

To get there, however, science will need many new tools for engineering biology, he added, but it will not be easy. “Such systems will likely be 10 to 50 times more complicated than current state-of-the-art genetic engineering projects,” he said. “We’re probably looking at a decade from when we started to get to a full byte.

The research was funded by the National Science Foundation’s Synthetic Biology Engineering Research Center, and by fellowship grants from Stanford’s Center for Longevity and its Bio-X program.

Ref.: Jerome Bonnet, Pakpoom Subsoontorn, and Drew Endy, Rewritable digital data storage in live cells via engineered control of recombination directionality, Proceedings of the National Academy of Sciences, 2012 DOI: 10.1073/pnas.1202344109 (open access)

Energy dashboard (credit: AlertMe)

AlertMe, the smart home tech company has sealed a deal with British Gas to provide a personalized energy efficiency advice service to UK customers with smart meters.

Smart meters will have a display that shows customers how much energy they are using. The AlertMe service breaks down the information for comparison with similar households, actionable recommendations (like getting insulation or double glazing to help keep in heat) and generally suggest ways in which customers can save money and not waste so much energy.

The free cloud-based service is being trialed with up to 10,000 homes during the summer and rolled out widely from the autumn. Smart meters from British Gas will be rolled out to all homes in the UK over the next seven years. Meanwhile, the Alertme system can be added to older gas meters.

Heating display (credit: AlertMe)

(Credit: Apple)

Apple has finalized the proposed design of its futuristic “spaceship” campus, featuring a rooftop with one of the biggest corporate solar installations in the entire world, to be operational by 2015.

See also: Apple plans new ‘spaceship’-like campus

SpaceX Falcon 9 Launches: The SpaceX Falcon 9 rocket soared into space from Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida, carrying the Dragon capsule to orbit at 3:44 a.m. EDT on Tuesday, May 22, 2012 (credit: NASA)

SpaceX‘s Falcon 9 rocket and Dragon spacecraft lifted off Tuesday from Cape Canaveral Air Force Station in Florida at 3:44 a.m. EDT, kicking off the second demonstration mission for NASA’s Commercial Orbital Transportation Services (COTS) program/

“Today marks the beginning of a new era in exploration; a private company has launched a spacecraft to the International Space Station that will attempt to dock there for the first time,” NASA Administrator Charles Bolden said.

The Dragon capsule will conduct a series of checkout procedures to test and prove its systems, including the capability to rendezvous and berth with the International Space Station.

On Thursday, May 24, Dragon will perform a flyby of the space station at a distance of approximately 1.5 miles to validate the operation of sensors and flight systems necessary for a safe rendezvous and approach. Live NASA TV coverage beginning at 2:30 a.m.

Following analysis of the flyby by NASA and SpaceX managers, the Dragon capsule will be cleared to rendezvous and berth with the space station on Friday, May 25, marking the first time a commercial company has attempted this feat. The Expedition 31 crew on board the station will use the orbiting complex’s robotic arm to capture Dragon and install it on the bottom side of the Harmony node. NASA TV will provide live coverage beginning at 2 a.m.

SpaceX and Orbital Sciences, which will perform its own test flight later this year, have been working under NASA’s COTS program, which provides investments to stimulate the commercial space industry in America. Once the companies have successfully completed their test flights, they will begin delivering regular cargo shipments to the station.

NASA also is developing the Orion spacecraft and Space Launch System (SLS), a crew capsule and heavy-lift rocket that will provide an entirely new capability for human exploration beyond low Earth orbit. Designed to be flexible for launching spacecraft for crew and cargo missions, SLS and Orion will expand human presence beyond low Earth orbit and enable new missions of exploration across the solar system.

(Credit: Google)

Comcast’s plans to do away with its 250 GB data cap and charge users based upon usage marks the end of an era for cable TV providers, and for the online video industry, TechCrunch reports.

So.cl (credit: Microsoft)

Over the weekend, Microsoft quietly launched an experimental social network called So.cl — a mix between Google+ and Storify.

You can search for information about a particular topic, then compile the best results — textual content, images and videos — into a single document.

So.cl is initially targeted to students. It may end up being useful as an academic tool, but it’s unlikely to get traction as a mainstream social network. Here’s why…

Researchers demonstrated quantum teleportation between La Palma and Tenerife, a distance of 143 km. (credit: Institute for Quantum Optics and Quantum Information)

Anton Zeilinger’s group (Institute for Quantum Optics and Quantum Information at the University of Vienna) has just submitted an arXiv paper claiming that they’ve demonstrated “quantum teleportation“ over a distance of 143 km (89 miles) in the Canary Islands. If confirmed, this sets a new world’s distance record in quantum teleportation, and also sets the stage for a future global quantum network for secure satellite communications.

Experiment overview for entanglement based quantum communication over 144 km. (credit: Institute for Quantum Optics and Quantum Information)

On May 9, researchers at the University of Science and Technology of China in Shanghai claimed that they had demonstrated quantum teleportation at a distance of 97 km (60 mi) across a lake in China. The previous published distance record was 16 km.

Quantum teleportation is actually not about teleporting matter — it’s the process of transferring the exact information about a particle from one place to another, using quantum entanglement, without the particle traveling through the intervening space.

In a related development, Space-QUEST, Zeilinger’s project on quantum entanglement for space experiments, demonstrated the exchange of a single photon between a low-Earth-orbit satellite and an Earth-based telescope in March 2008.

This wasn’t active communications, because the satellite only had a mirror, no quantum laser source. Their next step would be to install an active quantum laser on an external payload of the International Space Station, the researchers say.

Global space-based quantum networks

These new research projects validate the ability to send and receive photons under the same kinds of atmospheric interference conditions that would be required for a link between the earth and an orbiting satellite.

Successful demonstration of quantum entanglement at these distances is important as proof-of-concept for future space-based, global quantum networks, and to test the limits of entanglement at relativistic distances (in outer space). A key question: does entanglement remain valid at these length scales, or is it affected by gravity or physical distance?

In that connection, DARPA has just released a Broad Agency Announcement (BAA) soliciting “macroscopic quantum communications proposals which can combine the security of quantum communications with the distances/rates of macroscopic telecommunications. Proposed research should investigate innovative approaches that enable revolutionary advances in secure quantum communications.”

The DARPA announcement calls for some serious out-of-the-box thinking. The Chinese demonstration of quantum teleportation confirmed only 1171 teleported photons in four hours, experiencing a loss of 35–53 dB at a distance of 97 km.  The Austrian demonstration confirmed only 605 teleported photons in about 6.5 hours, experiencing a loss of 28–39 dB at a distance of 143 km.

Contrast that with the new DARPA program: they’re asking for researchers to demonstrate sustained transmission of secure quantum key rates of 1-10 Gigabits per second — at distances of 1,000–10,000 km — a real quantum leap (pun intended).

And they’re asking for these communications to be insensitive to the lossy, environmental decoherence that a dirty atmosphere presents to any experiment. According to DARPA: “Current techniques for quantum communication are highly sensitive to loss, with an increase in loss leading to a corresponding drop in bit rate (e.g., 10 dB of loss results in a factor of 10 decrease in secure bit rate). Successful programs are expected to present a method for decoupling loss from secure bit rate.”

The program has two secondary goals: to conclusively demonstrate that secure quantum communications can be extended to entirely new domains,  even underwater and through dirty air, and to extend macroscopic quantum communications to entirely new domains beyond the realm of key distribution.

Ref.: X. Ma et al., Quantum teleportation using active feed-forward between two Canary Islands, arxiv.org/pdf/1205.3909.pdf

Ref.: Juan Yin et al., Teleporting Independent Qubits Through A 97 Km Free-Space Channel, arxiv.org/abs/1205.2024

Also see: Rapid-fire single photons for quantum information processing

(Credit: Peter van der Sluijs/Wikimedia Commons)

Exercise clears the mind. It gets the blood pumping and more oxygen is delivered to the brain. But Dartmouth’s David Bucci thinks there is much more going on.

“In the last several years there have been data suggesting that neurobiological changes are happening — [there are] very brain-specific mechanisms at work here,” says Bucci, an associate professor in the Department of Psychological and Brain Sciences.

From his studies, Bucci and his collaborators have revealed important new findings:

• The effects of exercise are different on memory as well as on the brain, depending on whether the exerciser is an adolescent or an adult.
• A gene has been identified which seems to mediate the degree to which exercise has a beneficial effect. This has implications for the potential use of exercise as an intervention for mental illness.

Bucci began his pursuit of the link between exercise and memory with attention deficit hyperactivity disorder (ADHD), one of the most common childhood psychological disorders. Bucci is concerned that the treatment of choice seems to be medication.

“The notion of pumping children full of psycho-stimulants at an early age is troublesome,” Bucci cautions. “We frankly don’t know the long-term effects of administering drugs at an early age—drugs that affect the brain—so looking for alternative therapies is clearly important.”

Anecdotal evidence from colleagues at the University of Vermont started Bucci down the track of ADHD. Based on observations of ADHD children in Vermont summer camps, athletes or team sports players were found to respond better to behavioral interventions than more sedentary children. While systematic empirical data is lacking, this association of exercise with a reduction of characteristic ADHD behaviors was persuasive enough for Bucci.

Coupled with his interest in learning and memory and their underlying brain functions, Bucci and teams of graduate and undergraduate students embarked upon a project of scientific inquiry, investigating the potential connection between exercise and brain function. They published papers documenting their results, with the most recent now available in the online version of the journal Neuroscience.

Bucci is quick to point out that “the teams of both graduate and undergraduates are responsible for all this work, certainly not just me.” Michael Hopkins, a graduate student at the time, is first author on the papers.

Early on, laboratory rats that exhibit ADHD-like behavior demonstrated that exercise was able to reduce the extent of these behaviors. The researchers also found that exercise was more beneficial for female rats than males, similar to how it differentially affects male and female children with ADHD.

Moving forward, they investigated a mechanism through which exercise seems to improve learning and memory. This is “brain derived neurotrophic factor” (BDNF) and it is involved in growth of the developing brain. The degree of BDNF expression in exercising rats correlated positively with improved memory, and exercising as an adolescent had longer lasting effects compared to the same duration of exercise, but done as an adult.

“The implication is that exercising during development, as your brain is growing, is changing the brain in concert with normal developmental changes, resulting in your having more permanent wiring of the brain in support of things like learning and memory,” says Bucci. “It seems important to [exercise] early in life.”

Bucci’s latest paper was a move to take the studies of exercise and memory in rats and apply them to humans. The subjects in this new study were Dartmouth undergraduates and individuals recruited from the Hanover community.

Bucci says that, “the really interesting finding was that, depending on the person’s genotype for that trophic factor [BDNF], they either did or did not reap the benefits of exercise on learning and memory. This could mean that you may be able to predict which ADHD child, if we genotype them and look at their DNA, would respond to exercise as a treatment and which ones wouldn’t.”

Bucci concludes that the notion that exercise is good for health including mental health is not a huge surprise. “The interesting question in terms of mental health and cognitive function is how exercise affects mental function and the brain.” This is the question Bucci, his colleagues, and students continue to pursue.

Ref.: M.E. Hopkins, F.C. Davis, M.R. VanTieghem, P.J. Whalen, D.J. Bucci, Differential effects of acute and regular physical exercise on cognition and affect, Neuroscience, 2012, DOI: 10.1016/j.neuroscience.2012.04.056

(Credit: Ivan Martinez/Wikimedia Commons)

Do you feel guilty when you read a newspaper?

You probably should, according to BuzzFeed co-founder Jonah Peretti, who has “a moral issue” with print publishing and its environmental impact.

A Chinese manufacturer has introduced the Model MK802, a $74 USB thumb-drive sized computer, liliputing reports, beating the FXI Cotton Candy PC on a stick to market (it will be available soon for $200).

(Credit: Allwinner)

The MK802 is available from AliExpress for $74, or less if you order in bulk. It has a 1.5 GHz Allwiner A10 processor, 512MB of RAM, 4GB of storage, USB port, microSD card slot, and HDMI port. It also features 802.11b/g WiFi and support for HD video playback in a variety of media formats.

It ships with Google Android 4.0 software, but theoretically you should be able to install Ubuntu or other operating systems.

Zero Devices is preparing to launch the Z802 which looks nearly identical, except for the Zero Devices logo on the front of the device, and available for pre-order from some sources for about $76.

New results from NASA's NEOWISE survey find that more potentially hazardous asteroids, or PHAs, are closely aligned with the plane of our solar system than previous models suggested, coming within 5 million miles (about 8 million kilometers) of Earth (credit: NASA/JPL-Caltech)

There are roughly 4,700 potentially hazardous asteroids (PHAs) with diameters larger than 330 feet (about 100 meters). So far, an estimated 20 to 30 percent of these objects have been found, according to observations from NASA’s Wide-field Infrared Survey Explorer (WISE), which have led to the best assessment yet of our solar system’s population of potentially hazardous asteroids.

Potentially hazardous asteroids are a subset of the larger group of near-Earth asteroids. The PHAs have the closest orbits to Earth’s, coming within five million miles (about eight million kilometers), and they are big enough to survive passing through Earth’s atmosphere and cause damage on a regional, or greater, scale.

The new results come from the asteroid-hunting portion of the WISE mission, called NEOWISE. The project sampled 107 PHAs to make predictions about the entire population as a whole. Findings indicate there are roughly 4,700 PHAs, plus or minus 1,500, with diameters larger than 330 feet (about 100 meters). So far, an estimated 20 to 30 percent of these objects have been found.

While previous estimates of PHAs predicted similar numbers, they were rough approximations. NEOWISE has generated a more credible estimate of the objects’ total numbers and sizes. It suggests that about twice as many PHAs as previously thought are likely to reside in “lower-inclination” orbits, which are more aligned with the plane of Earth’s orbit.

In addition, these lower-inclination objects appear to be somewhat brighter and smaller than the other near-Earth asteroids that spend more time far away from Earth. A possible explanation is that many of the PHAs may have originated from a collision between two asteroids in the main belt lying between Mars and Jupiter. A larger body with a low-inclination orbit may have broken up in the main belt, causing some of the fragments to drift into orbits closer to Earth and eventually become PHAs.

This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). PHAs are a subset of the near-Earth asteroids (NEAs). They have the closest orbits to Earth's orbit, coming within 5 million miles (about 8 million kilometers), and they are large enough to survive passage through Earth's atmosphere and cause damage on a regional, or greater, scale. (Credit: NASA/JPL-Caltech)

Asteroids with lower-inclination orbits would be more likely to encounter Earth and would be easier to reach. The results therefore suggest more near-Earth objects might be available for future robotic or human missions.

“NASA’s NEOWISE project, which wasn’t originally planned as part of WISE, has turned out to be a huge bonus,” said Amy Mainzer, NEOWISE principal investigator, at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Everything we can learn about these objects helps us understand their origins and fate. Our team was surprised to find the overabundance of low-inclination PHAs. Because they will tend to make more close approaches to Earth, these targets can provide the best opportunities for the next generation of human and robotic exploration.”

The discovery that many PHAs tend to be bright says something about their composition; they are more likely to be either stony, like granite, or metallic. This type of information is important in assessing the space rocks’ potential hazards to Earth. The composition of the bodies would affect how quickly they might burn up in our atmosphere if an encounter were to take place.

Dubai Panorama (credit: Stephen Wiltshire)

How can we explain “acquired savants” — people with extraordinary talent who’ve miraculously developed artistic, musical, or mathematical abilities as a result of a brain injury, or temporarily from a transcranial magnetic stimulation (TMS) session — since they weren’t born with the talent and didn’t learn it later?

For example, how is it that somebody like Derek Amato (video below), who’d never demonstrated any musical talent before hitting his head at the bottom of a pool, could suddenly handle jazz and classical pieces of astounding complexity without training?

Darold A. Treffert, M.D., Clinical Professor of Psychiatry at the University of Wisconsin School of Medicine and consultant for the movie Rain Man, speculates that it could be the result of  what he calls “genetic memory” (“ancestral memory”) that is triggered by rewiring of the brain to compensate for the injury.

See also:

Savant Syndrome (Darold Treffert website)

Islands of Genius: The Bountiful Mind of the Autistic, Acquired, and Sudden Savant, Darold Treffert and Jessica Kingsley Publishers, 2011

“Ancestral” or “Genetic” Memory: Factory Installed Software Darold Treffert, 2011

Conversations on Creativity with Darold Treffert, Psychology Today, April 27, 2011 (open access)

Augmenting Cognition,  Idan Segev and Henry Markram, EFPL Press, 2011

Stephen Wiltshire MBE

While the article in The Atlantic does not cover new findings, it summarizes some of the key ideas well. — Ed.

(Credit: Julius Schorzman/Wikimedia Commons)

Older adults who drank coffee — caffeinated or decaffeinated — had a lower risk of death overall than others who did not drink coffee, according a study by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, and AARP.

Coffee drinkers were less likely to die from heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections, although the association was not seen for cancer.

These results from a large study of older adults were observed after adjustment for the effects of other risk factors on mortality, such as smoking and alcohol consumption.

Researchers caution, however, that they can’t be sure whether these associations mean that drinking coffee actually makes people live longer.

Neal Freedman, Ph.D., Division of Cancer Epidemiology and Genetics, NCI, and his colleagues examined the association between coffee drinking and risk of death in 400,000 U.S. men and women ages 50 to 71 who participated in the NIH-AARP Diet and Health Study. Information about coffee intake was collected once by questionnaire at study entry in 1995-1996. The participants were followed until the date they died or Dec. 31, 2008, whichever came first.

The researchers found that the association between coffee and reduction in risk of death increased with the amount of coffee consumed. Relative to men and women who did not drink coffee, those who consumed three or more cups of coffee per day had approximately a 10 percent lower risk of death. Coffee drinking was not associated with cancer mortality among women, but there was a slight and only marginally statistically significant association of heavier coffee intake with increased risk of cancer death among men.

“Coffee is one of the most widely consumed beverages in America, but the association between coffee consumption and risk of death has been unclear. We found coffee consumption to be associated with lower risk of death overall, and of death from a number of different causes,” said Freedman. “Although we cannot infer a causal relationship between coffee drinking and lower risk of death, we believe these results do provide some reassurance that coffee drinking does not adversely affect health.”

The investigators caution that coffee intake was assessed by self-report at a single time point and therefore might not reflect long-term patterns of intake. Also, information was not available on how the coffee was prepared (espresso, boiled, filtered, etc.); the researchers consider it possible that preparation methods may affect the levels of any protective components in coffee.

“The mechanism by which coffee protects against risk of death — if indeed the finding reflects a causal relationship — is not clear, because coffee contains more than 1,000 compounds that might potentially affect health,” said Freedman. “The most studied compound is caffeine, although our findings were similar in those who reported the majority of their coffee intake to be caffeinated or decaffeinated.”

Ref.: Neal D. Freedman et al., Association of Coffee Drinking with Total and Cause-Specific Mortality, New England Journal of Medicine, 2012, DOI: 10.1056/NEJMoa1112010

Wireless power transfer experimental setup (credit: Z. Pantic and S. Lukic)

Researchers from North Carolina State University (NC State) have developed a new way to fine-tune wireless power transfer (WPT) receivers, making the systems more efficient and functional. WPT systems hold promise for charging electric vehicles, electronic devices, and other technologies.

Researchers have previously shown that it is possible to transmit power wirelessly by using magnetic resonance, but even minor changes in how the transmitter or receiver is tuned can result in faulty power transmission when the resonant frequencies don’t match.

A new prototype developed at NC State addresses the problem by automatically and precisely re-tuning the receivers in WPT systems. The researchers focused on receivers because methods already exist that allow researchers to use electronics to precisely tune the transmitters.

“We’re optimistic that this technology moves us one step closer to realizing functional WPT systems that can be used in real-world circumstances,” says Dr. Srdjan Lukic, an assistant professor of electrical and computer engineering at NC State and co-author of a paper on the research.

How it works

Structure of the WPT system

WPT systems work by transmitting magnetic waves on a specific frequency from a transmitter to a receiver. These magnetic waves interact with a coil in the receiver to induce an electric current. If the coil is tuned so that its resonant frequency matches the frequency of the magnetic waves, the current it produces is amplified.

However, if the receiver and the transmitter frequencies differ even slightly, the system becomes inefficient and doesn’t transfer a significant amount of power. This is a problem because many factors can affect the tuning of a receiver or transmitter, such as temperature or proximity to other magnetic objects. In other words, a hot summer day could wreak havoc on the tuning of a receiver.

The engineers developed an electronic prototype that incorporates additional circuitry into the receiver that does two things: it injects small amounts of reactive power into the receiver coil as needed to maintain its original resonant frequency; and if the transmitter’s tuning changes, the prototype can read the trace amount of current being transmitted and tune the receiver’s frequency to match. The effect is similar to autotuning vocal pitch in pop music.

“Because we are using electronics to inject reactive power into the receiver coil, we can be extremely precise when tuning the receiver,” Lukic says. “This degree of fine-tuning maximizes the efficiency of the WPT system. The next step is to try incorporating this work into technology that can be used to wirelessly charge electric vehicles.”

Z. Pantic, S. Lukic, Framework and Topology for Active Tuning of Parallel Compensated Receivers in Wireless Power Transfer Systems, IEEE Transactions on Power Electronics, 2012, DOI: 10.1109/TPEL.2012.2196055

New York City Stock Exchange (credit: Norbert Nagel/Wikimedia Commons)

World stocks fell Friday after credit downgrades slapped on Spanish banks unnerved investors already worried about the stability of the 17-country euro currency union.

Political turmoil in Greece has increased the likelihood that it could leave the 17-country monetary union, a move that could have ripple effects throughout Europe and the world’s financial markets.

Markets were jolted by Moody’s downgrade Thursday of 16 Spanish banks, said Jackson Wong, vice president at Tanrich Securities in Hong Kong.

In currencies, the euro fell to $1.2686 from $1.2714 late Thursday in New York. The dollar rose slightly to 79.30 yen from 79.28 yen.