David Kirkpatrick

August 25, 2010

The downside of all those digital devices

Via KurzweilAI.net — They eat into our downtime.

From the link:

Digital Devices Deprive Brain of Needed Downtime

August 25, 2010

Source: New York Times, Aug 24, 2010

When people keep their brains busy with digital input, they are forfeiting downtime that could allow them to better learn and remember information, or come up with new ideas.

At the University of California, San Francisco, scientists have found that when rats have a new experience, like exploring an unfamiliar area, their brains show new patterns of activity. But only when the rats take a break from their exploration do they process those patterns in a way that seems to create a persistent memory of the experience.

The researchers suspect that the findings also apply to how humans learn.

At the University of Michigan, a study found that people learned significantly better after a walk in nature than after a walk in a dense urban environment, suggesting that processing a barrage of information leaves people fatigued.

Read original article

May 13, 2010

Molecular nanobots

Via KurzweilAI.net — very cool! As always, I’ve included the entire KurzweilAI post. This one is a bit longer than usual.

How to make a molecular nanobot
KurzweilAI.net, May 13, 2010

Scientists have programmed an autonomous molecular nanorobot made out of DNA to start, move, turn, and stop while following a DNA track.


(Paul Michelotti)

The development could ultimately lead to molecular systems that could be used for medical therapeutic devices and molecular-scale reconfigurable robots—robots made of many simple units that can reposition or even rebuild themselves to accomplish different tasks.

Molecular robots, in theory, could be programmed to sense their environment (say, the presence of disease markers on a cell), make a decision (that the cell is cancerous and needs to be neutralized), and act on that decision (deliver a cargo of cancer-killing drugs). Or they could be programmed to assemble complex molecular products.

“In normal robotics, the robot itself contains the knowledge about the commands, but with individual molecules, you can’t store that amount of information, so the idea instead is to store information on the commands on the outside,” says Nils G. Walter, professor of chemistry and director of the Single Molecule Analysis in Real-Time (SMART) Center at the University of Michigan in Ann Arbor. And you do that by “imbuing the molecule‘s environment with informational cues,” says Milan N. Stojanovic, a faculty member in the Division of Experimental Therapeutics at Columbia University.

“We were able to create such a programmed or ‘prescribed’ environment using DNA origami,” explains Hao Yan, professor of chemistry and biochemistry at Arizona State University. DNA origami is a type of self-assembledstructure made from DNA that can be programmed to form nearly limitless shapes and patterns. Exploiting the sequence-recognition properties of DNA base pairing, DNA origami are created from a long single strand of DNA and a mixture of different short synthetic DNA strands that bind to and “staple” the long DNA into the desired shape. The origami used in the Nature study was a rectangle that was 2 nanometers (nm) thick and roughly 100 nm on each side.

The researchers constructed a trail of molecular “bread crumbs” on the DNA origami track by stringing additional single-stranded DNA molecules, or oligonucleotides, off the ends of the staples. These represent the cues that tell the molecular robots what to do—start, walk, turn left, turn right, or stop, for example—akin to the commands given to traditional robots.

To build the 4-nm-diameter molecular robot, the researchers started with a common protein called streptavidin, which has four symmetrically placed binding pockets for a chemical moiety called biotin. Each robot leg is a short biotin-labeled strand of DNA, “so this way we can bind up to four legs to the body of our robot,” Walter says. “It’s a four-legged spider,” quips Stojanovic. Three of the legs are made of enzymatic DNA, which is DNA that binds to and cuts a particular sequence of DNA. The spider also is outfitted with a “start strand”—the fourth leg—that tethers the spider to the start site (one particular oligonucleotide on the DNA origami track). “After the robotis released from its start site by a trigger strand, it follows the track by binding to and then cutting the DNA strands extending off of the staple strands on the molecular track,” Stojanovic explains.

“Once it cleaves,” adds Yan, “the product will dissociate, and the leg will start searching for the next substrate.” In this way, the spider is guided down the path laid out by the researchers. Finally, explains Yan, “the robot stops when it encounters a patch of DNA that it can bind to but that it cannot cut,” which acts as a sort of flypaper.

Using atomic force microscopy and single-molecule fluorescence microscopy, the researchers were able to watch spiders crawling over the origami, showing that they were able to guide their molecular robots to follow four different paths.

More info: Caltech news and Molecular robots guided by prescriptive landscapes

March 17, 2010

Amazing nanotech image — nanoparticle ribbons twisted by light

Truly amazing finding to go along with a very cool image:

After 72 hours of exposure to ambient light, strands of nanoparticles twisted and bunched together. Credit: Nicholas Kotov

Be sure and hit the link up there for the full release on this news, and for a very, very large version of this image.

August 20, 2009

Food for taxation thought

An interesting study out of the University of Michigan on the federal income tax and how that tax burden is spread out by region and size of your home town or city.

The release:

City dwellers bear disproportionate federal tax burden

Live in an expensive city? Think you pay too much in federal taxes? If so, a study in the current issue of the Journal of Political Economy finds that you’re exactly right.

According to David Albouy, a University of Michigan economist, workers in expensive cities in the Northeast, Great Lakes and Pacific regions bear a disproportionate share of the federal tax burden, effectively paying 27 percent more in federal income taxes than workers with similar skills in a small city or rural area.

Why the disparity? Workers in cities are generally paid higher wages than similarly skilled workers in smaller towns, so they’re taxed at higher rates. That may sound fair, until one considers the higher cost of living in cities, which means those higher wages don’t provide any extra buying power. The federal income tax system doesn’t account for cost of living. So the effect is that workers in expensive cities like New York, Los Angeles and Chicago pay more in taxes even though their real income is essentially the same as workers in smaller, cheaper places.

The extra burden wouldn’t be so excessive if more federal tax dollars were returned to urban areas in the form of higher federal spending. But according to Albouy’s research, that’s not the case. His data show that more federal dollars are actually spent in rural areas, despite the fact that cities send far more cash to Washington. The net effect of all this is a transfer of $269 million from workers in high-cost areas to workers in lower cost rural areas in 2008 alone.

Over the long haul, Albouy says, the larger tax burden causes workers to flee large urban centers in the Northeast and settle in less expensive places in the South. So to some extent, it may have been the federal tax system that put the rust on the rust belt.

Detroit is a perfect example of a city that gets the short end of the stick.

“With its high wage levels, Detroit was, until recently, contributing far more in federal revenues per capita than most other places for over one hundred years,” Albouy said. The recent federal bailout to Detroit automakers “is peanuts relative to the extra billions the city has poured into Washington over the 20th Century.”

One expensive area that escapes the higher burden is Hawaii. Costs in Hawaiian cities are high, but wages remain low because people are willing to accept lower pay to live by the beach. As a result, Hawaiians aren’t pounded by taxes the way New Yorkers are. But it also means that “powerhouse cities like New York indirectly subsidize people to live in really nice locations like Hawaii,” Albouy said.

Albouy’s analysis adds new empirical weight to a debate that started in the 1970s with the late New York Senator Daniel Patrick Moynihan. Moynihan commissioned a series of reports that showed the Northeast and Midwest sent far more money to Washington than it got back. Albouy’s research is the first to provide an estimate of how much more individual workers in cities pay.

Albouy says that city folk shouldn’t expect relief from this system anytime soon.

“Highly taxed areas tend to be in large cities inside of populous states, which have low Congressional representation per capita, making the prospect of reform daunting,” he writes.

 

###

 

David Albouy, “The Unequal Geographic Burden of Federal Taxation,” Journal of Political Economy 117:4, August 2009.

One of the oldest and most prestigious journals in economics, the Journal of Political Economy has since 1892 presented significant research and scholarship in economic theory and practice. The journal aims to publish highly selective, widely cited articles of current relevance that will have a long-term impact on economics research.

July 3, 2009

Second Life contributes to social research

I’ve blogged on MMORPGs and social research here and here amonst other times, and I still find it fascinating — although not surprising — that university research is turning to virtual communities for social research. It’s real people interacting and simply by its nature everything collected is both data rich and pre-formatted for the most part. A researchers dream.

The latest release on virtual communities and social research (aside from dk: I spotted a typo in the release. Can you find it?):

Second Life data offers window into how trends spread

ANN ARBOR, Mich.—Do friends wear the same style of shoe or see the same movies because they have similar tastes, which is why they became friends in the first place? Or once a friendship is established, do individuals influence each other to adopt like behaviors?

Social scientists don’t know for sure. They’re still trying to understand the role social influence plays in the spreading of trends because the real world doesn’t keep track of how people acquire new items or preferences.

But the virtual world Second Life does. Researchers from the University of Michigan have taken advantage of this unique information to study how “gestures” make their way through this online community. Gestures are code snippets that Second Life avatars must acquire in order to make motions such as dancing, waving or chanting.

Roughly half of the gestures the researchers studied made their way through the virtual world friend by friend.

“We could have found that most everyone goes to the store to buy gestures, but it turns out about 50 percent of gesture transfers are between people who have declared themselves friends. The social networks played a major role in the distribution of these assets,” said Lada Adamic, an assistant professor in the School of Information and the Department of Electrical Engineering and Computer Science.

Adamic is an author of a paper on the research that graduate student Eytan Bakshy will present on July 7 at the Association for Computer Machinery’s Conference on Electronic Conference in Stanford, Calif. Bakshy is a doctoral student in the School of Information.

“There’s been a high correspondence between the real world and virtual worlds,” Adamic said. “We’re not saying this is exactly how people share in the real world, but we believe it does have some relevance.”

This study is one of the first to model social influence in a virtual world because of the rarity of having access to information about how information, assets or ideas propagate. In Second Life, the previous owner of a gesture is listed.

The researchers also found that the gestures that spread from friend to friend were not distributed as broadly as ones that were distributed outside of the social network, such as those acquired in stores or as give-aways.

And they discovered that the early adopters of gestures who are among the first 5-10 percent to acquire new assets are not the same as the influencers, who tend to distribute them most broadly. This aligns with what social scientists have found.

“In our study, we sought to develop a more rigorous understanding of social processes that underlies many cultural and economic phenomena,” Bakshy said. “While some of our findings may seem quite intuitive, what I find most exciting is that we were actually able to test some rather controversial and competing hypotheses about the role of social networks in influence.”

The researchers examined 130 days worth of gesture transfers in late 2008 and early 2009. They looked at 100,229 users and 106,499 gestures. They obtained the data from Linden Lab, the maker of Second Life. Personally-identifying information had been removed.

 

###

 

The paper is called, “Social Influence and the Diffusion of User-Created Content.” The research is funded by the National Science Foundation. Physics graduate student Brian Karrer is also a co-author.

For more information:

Full text of paper:
http://www-personal.umich.edu/~ladamic/

ACM Conference on Electronic Commerce:
http://www.sigecom.org/ec09/

August 26, 2008

Cloud computing brings security benefits

I’ve blogged on cloud computing before and this Technology Review article suggests the concept might be the best way to keep PCs virus-free.

From the second link:

Most people know better than to connect a computer to the Internet without first installing up-to-date antivirus software. But even the best software protection won’t catch every new virus, and performing a thorough system scan can require plenty of processor power, slowing some computers to a crawl.

New research from the Universityof Michigan suggests that computers could be better protected from viruses without sacrificing performance if antivirus software were moved from the PC to “the cloud”–a collection of servers that work seamlessly as one powerful machine. Using this approach, researchers found that they could detect 35 percent more recent viruses than a single antivirus program (88 percent compared with 73 percent). Moreover, using the distributed software, called Cloud AV, they caught 98 percent of all malicious software, compared with 83 percent, on average, for a single antivirus solution.

August 25, 2008

Flat-panel nanotech ion thrusters

Filed under: Science, Technology — Tags: , , , , — David Kirkpatrick @ 11:10 pm

From KurzweilAI.net — this is a really cool innovation. Spacecraft ion thrusters as flat-panels mounted on the side of spacecraft. All created by nanotechnology.

Flat-panel ion thrusters
New Scientist news service, Aug. 22, 2008

University of Michigan researchers propose that tiny “nano thrusters” could be made into flat sheets mounted on the side of spacecraft.

Nanoparticles just tens of nanometers across are ionized by electrodes in a chamber. Those charged ions are accelerated by the electric field and ejected from a vent, producing thrust.

 
Read Original Article>>

July 15, 2008

The latest in energy-efficient lighting

I love the idea of energy-efficient lighting. Went all compact fluorescent a couple of years ago, and haven’t looked back. I’m pretty excited about the possibilities of LED once that tech comes way, way down in price.

(Update 7/28/08 — This update is positioned this high because I wanted to get it above long release. Here’s a link to a Technology Review article on this release’s material.)

On the same vein, here’s a press release from the University of Michigan News Service on the latest technology in efficient lighting:

July 15, 2008

Freeing light shines promise on energy-efficient lighting

ANN ARBOR, Mich.—The latest bright idea in energy-efficient lighting for homes and offices uses big science in nano-small packages to dim the future Edison’s light bulb.

In the August issue of Nature Photonics, available online, scientists at the University of Michigan and Princeton University announce a discovery that pushes more appealing white light from organic light-emitting devices.

More white light is the holy grail of the next generation of lighting. The innovation in the paper “Enhanced Light Out-Coupling of Organic Light-Emitting Devices Using Embedded Low-Index Grids” describes a way to deliver significantly more bright light from a watt than incandescent bulbs.

“Our demonstration here shows that OLEDs are a very exciting technology for use in interior illumination,” said Stephen Forrest, U-M professor of electrical engineering and physics and vice president for research. “We hope that white emitting OLEDs will play a major role in the world of energy conservation.”

Forrest and co-author Yuri Sun, visiting U-M from Princeton University, have wrestled with a classic problem in the new generation of lighting called white organic light-emitting devices, or WOLED: Freeing the light generated, but mostly trapped, inside the device.

A lighting primer: Incandescent light bulbs give off light as a by-product of heat, The light is appealing, but inefficient, putting out 15 lumens of light for every watt or electricity.

The best fluorescent tube lights put out some 90 lumens of light per watt, but the light can be harsh, the fixtures are expensive, and the tubes lose their efficiency with age. And they rely on many environmentally unfriendly substances such as mercury.

WOLEDs show promise of providing a light that’s much easier to manipulate, while being long lasting and able to provide in different shapes, from panels to bulbs and more. WOLEDs generate white light by using electricity to send an electron into nanometer thick layers of organic materials that serve as semiconductors. These carbon-based materials are dyes, the ones used in photographic prints and car paint, so they are very inexpensive, and can be put on plastic sheets or metal foils, further reducing costs.

The excited electron in these layers casts bright white light. The bad news, Forrest said, has been that some 60 percent of it is trapped inside the layers, much the way light under water reflects back into the pool, making the water surface seem like a mirror when viewed from underneath.

The Nature Photonics paper describes a tandem system of organic grids and micro lenses that guide the light out of the thin layers and into the air. The grids refract the trapped light, bouncing it into a layer of dome-shaped lenses that then pull the light out.

This process—all of which is packed into a lighting sandwich roughly the thickness of a sheet of paper—was shown to emit approximately 70 lumens from a single watt of power.

More light out means getting more bang for the electricity buck, a crucial question since 22 percent of the U.S. electricity consumption is lighting.

“If you can change the light efficiency by just a few percentage points, there’s a few less coal plants you’ll need,” Forrest said.

Reducing the amount of coal-generated electricity and finding more efficient ways to power appliances and lighting is one of the focuses of U-M’s Michigan Memorial Phoenix Energy Institute, and the WOLED work is one example of how science can open new doors in conservation, said Gary Was, institute director.

“That energy efficient lighting can be made from the same materials as car paint and that they can be made in such thin, formable sheets boggles the mind,” Was said. “This is one of many exciting creations that research is giving us in the pursuit of energy efficiency. This is also the kind of innovation that is required in the drive for energy sustainability.

Forrest said WOLED work isn’t done yet. The fun part, he said, is that WOLEDs can be framed in different forms.

“Plugging into a wall at low voltage, putting it on a flexible metal foil, or on plastic that won’t break when you drop it,” Forrest said. “This is what makes it so fun because it’s such a unique lighting source.”

The research was funded by the U.S. Department of Energy through a subcontract from the University of Southern California and by Universal Display Corp.

Forrest is part of the Michigan Memorial Phoenix Energy Institute, which develops, coordinates and promotes multidisciplinary energy research and education at U-M. He also is on the scientific advisory board of Universal Display Corp.

The next challenge, he said, is to reduce the cost, which currently is too high to be commercially competitive.

“You have to be able to do this dirt cheap, Forrest said. “People don’t spend much for their light bulbs.”

 

 

Related Links:

Michigan Memorial Phoenix Energy Institute

July 8, 2008

Medical nanotech, picowatt processor and a 400 gig disc

From KurzweilAI.net — nanosensors that constantly monitor patient’s blood markers, here’s a tiny picowatt processor and a 16-layer, 400 gigabyte optical disc from Pioneer.

Nanosensors for Medical Monitoring
Technology Review, July 8, 2008Vista Therapeutics is developing sensitive devices for continuous bedside monitoring of blood biomarkers for detecting organ failure and other problems in seriously injured or ill patients, such as those in the ICU after suffering a heart attack or traumatic injuries from a car accident.The devices use silicon nanowires developed by Harvard University chemist Charles Lieber. When a single protein binds to an antibody along the wire, the current flowing through the wire changes. Arrays of hundreds of nanowires, each designed to detect a different molecule in the same sample, can be arranged on tiny, inexpensive chips. The changes can be monitored continuously as molecules bind and unbind, making it possible to detect subtle trends over time, without requiring multiple blood draws.

Because nanowires are so sensitive and inexpensive, they could also find their way into home tests for cancer.

 
Read Original Article>>

A Picowatt Processor
Technology Review, July 8, 2008University of Michigan have made a processor (the Phoenix) that measures just one millimeter square with a power consumption so low (2.8 picojoules of energy per computing cycle) that emerging thin-film batteries of the same size could power it for 10 years or more.At this scale, it could be feasible to build the chip into a thick contact lens and use it to monitor pressure in the eye, which would be useful for glaucoma detection. It could also be implanted under the skin to sense glucose levels in subcutaneous fluid. It could also be used in environmental sensors that monitor pollution, or structural health sensors, for instance.

 
Read Original Article>>

Pioneer Develops World’s First 16-Layer Optical Disc
PhysOrg.com, July 7, 2008Pioneer Corporation has developed a 16-layer read-only optical disc with a capacity of 400 gigabytes.
 
Read Original Article>>

February 19, 2008

Record setting laser

Filed under: Science, Technology — Tags: , , — David Kirkpatrick @ 12:58 am

Yowza.

Laser beam sets record for intensity
KurzweilAI.net, Feb. 18, 2008 The world’s most intense laser beam uses 300 terawatts of power concentrated in a 30 femtosecond pulse to a 1.3-micron area, or 20 billion trillion watts per square centimeter.University of Michigan news release