Monday, August 2, 2010

TAKING MUSIC SERIOUSLY

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Those ubiquitous wires connecting listeners to you-name-the-sounds from invisible MP3 players -- whether of Bach, Miles Davis or, more likely today, Lady Gaga -- only hint at music's effect on the soul throughout the ages.

Now a data-driven review by Northwestern University researchers that was published July 20 in Nature Reviews Neuroscience pulls together converging research from the scientific literature linking musical training to learning that spills over to skills including language, speech, memory, attention and even vocal emotion. The science covered comes from labs all over the world, from scientists of varying scientific philosophies, using a wide range of research methods.

The explosion of research in recent years focusing on the effects of music training on the nervous system, including the studies in the review, have strong implications for education, said Nina Kraus, lead author of the Nature perspective, the Hugh Knowles Professor of Communication Sciences and Neurobiology and director of Northwestern's Auditory Neuroscience Laboratory.

Scientists use the term neuroplasticity to describe the brain's ability to adapt and change as a result of training and experience over the course of a person's life. The studies covered in the Northwestern review offer a model of neuroplasticity, Kraus said. The research strongly suggests that the neural connections made during musical training also prime the brain for other aspects of human communication.

An active engagement with musical sounds not only enhances neuroplasticity, she said, but also enables the nervous system to provide the stable scaffolding of meaningful patterns so important to learning.

"The brain is unable to process all of the available sensory information from second to second, and thus must selectively enhance what is relevant," Kraus said. Playing an instrument primes the brain to choose what is relevant in a complex process that may involve reading or remembering a score, timing issues and coordination with other musicians.

"A musician's brain selectively enhances information-bearing elements in sound," Kraus said. "In a beautiful interrelationship between sensory and cognitive processes, the nervous system makes associations between complex sounds and what they mean." The efficient sound-to-meaning connections are important not only for music but for other aspects of communication, she said.

The Nature article reviews literature showing, for example, that musicians are more successful than non-musicians in learning to incorporate sound patterns for a new language into words. Children who are musically trained show stronger neural activation to pitch changes in speech and have a better vocabulary and reading ability than children who did not receive music training.

And musicians trained to hear sounds embedded in a rich network of melodies and harmonies are primed to understand speech in a noisy background. They exhibit both enhanced cognitive and sensory abilities that give them a distinct advantage for processing speech in challenging listening environments compared with non-musicians.

Children with learning disorders are particularly vulnerable to the deleterious effects of background noise, according to the article. "Music training seems to strengthen the same neural processes that often are deficient in individuals with developmental dyslexia or who have difficulty hearing speech in noise."

Currently what is known about the benefits of music training on sensory processing beyond that involved in musical performance is largely derived from studying those who are fortunate enough to afford such training, Kraus said.

The research review, the Northwestern researchers conclude, argues for serious investing of resources in music training in schools accompanied with rigorous examinations of the effects of such instruction on listening, learning, memory, attention and literacy skills.

"The effect of music training suggests that, akin to physical exercise and its impact on body fitness, music is a resource that tones the brain for auditory fitness and thus requires society to re-examine the role of music in shaping individual development,” the researchers conclude.

Northwestern University

NOW YOU SEE IT, NOW YOU DON'T

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From Tolkien's ring of power in The Lord of the Rings to Star Trek's Romulans, who could make their warships disappear from view, from Harry Potter's magical cloak to the garment that makes players vanish in the video game classic Dungeons and Dragons, the power to turn someone or something invisible fascinates mankind. But who ever thought that a scientist at Michigan Technological University would be serious about building a working invisibility cloak?

That's exactly what Elena Semouchkina, an associate professor of electrical and computer engineering at Michigan Tech, is doing. She has found ways to use magnetic resonance to capture rays of visible light and route them around objects, rendering those objects invisible to the human eye.

Semouchkina and colleagues at the Pennsylvania State University, where she is also an adjunct professor, recently reported on their research in the journal Applied Physics Letters, published by the American Institute of Physics. Her co-authors were Douglas Werner and Carlo Pantano of Penn State and George Semouchkin, who works at Michigan Tech and Penn State.

They describe developing a nonmetallic cloak that uses identical glass resonators made of chalcogenide glass, a type of dielectric material (one that does not conduct electricity). In computer simulations, the cloak made objects hit by infrared waves—approximately one micron or one-millionth of a meter long—disappear from view.

Earlier attempts by other researchers used metal rings and wires. "Ours is the first to do the cloaking of cylindrical objects with glass," Semouchkina said.

Her invisibility cloak uses metamaterials, which are artificial materials having properties that do not exist in nature, made of tiny glass resonators arranged in a concentric pattern in the shape of a cylinder. The "spokes" of the concentric configuration produce the magnetic resonance required to bend light waves around an object, making it invisible.

Metamaterials, which huse small resonators instead of atoms or molecules of natural materials, straddle the boundary between materials science and electrical engineering. They were named one of the top three physics discoveries of the decade by the American Physical Society. A new researcher specializing in metamaterials is joining Michigan Tech's faculty this fall.

Semouchkina and her team now are testing an invisibility cloak rescaled to work at microwave frequencies and made of ceramic resonators. They're using Michigan Tech's anechoic chamber, a cave-like compartment in an Electrical Energy Resources Center lab, lined with highly absorbent charcoal-gray foam cones. There, antennas transmit and receive microwaves, which are much longer than infrared light, up to several centimeters long. They have cloaked metal cylinders two to three inches in diameter and three to four inches high.

"Starting from these experiments, we want to move to higher frequencies and smaller wavelengths," the researcher said. "The most exciting applications will be at the frequencies of visible light."

So one day, could the police cloak a swat team or the Army, a tank? "It is possible in principle, but not at this time," Semouchkina said.

(Photo: Michigan TU)

Michigan Technological University

NANOTECH COATINGS PRODUCE 20 TIMES MORE ELECTRICITY FROM SEWAGE

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Engineers at Oregon State University have made a significant advance toward producing electricity from sewage, by the use of new coatings on the anodes of microbial electrochemical cells that increased the electricity production about 20 times.

The findings, just published online in Biosensors and Bioelectronics, a professional journal, bring the researchers one step closer to technology that could clean biowaste at the same time it produces useful levels of electricity – a promising new innovation in wastewater treatment and renewable energy.

Engineers found that by coating graphite anodes with a nanoparticle layer of gold, the production of electricity increased 20 times. Coatings with palladium produced an increase, but not nearly as much. And the researchers believe nanoparticle coatings of iron – which would be a lot cheaper than gold – could produce electricity increases similar to that of gold, for at least some types of bacteria.

“This is an important step toward our goal,” said Frank Chaplen, an associate professor of biological and ecological engineering. “We still need some improvements in design of the cathode chamber, and a better understanding of the interaction between different microbial species. But the new approach is clearly producing more electricity.”

In this technology, bacteria from biowaste such as sewage are placed in an anode chamber, where they form a biofilm, consume nutrients and grow, in the process releasing electrons. In this context, the sewage is literally the fuel for electricity production.

In related technology, a similar approach may be able to produce hydrogen gas instead of electricity, with the potential to be used in hydrogen fuel cells that may power the automobiles of the future. In either case, the treatment of wastewater could be changed from an energy-consuming technology into one that produces usable energy.

Researchers in the OSU College of Engineering and College of Agricultural Sciences, including Hong Liu, an assistant professor of biological and ecological engineering, are national leaders in development of this technology, which could significantly reduce the cost of wastewater treatment in the United States. It might also find applications in rural areas or developing nations, where the lack of an adequate power supply makes wastewater treatment impractical. It may be possible to create sewage treatment plants that are completely self-sufficient in terms of energy usage.

The technology already works on a laboratory basis, researchers say, but advances are necessary to lower its cost, improve efficiency and electrical output, and identify the lowest cost materials that can be used.

This research has been supported by the National Science Foundation and the Oregon Nanoscience and Microtechnologies Institute.

“Recent advances in nanofabrication provide a unique opportunity to develop efficient electrode materials due to the remarkable structural, electrical and chemical properties of nanomaterials,” the researchers wrote in their report. “This study demonstrated that nano-decoration can greatly enhance the performance of microbial anodes.”

Oregon State University

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