Discovery Brings New Type Of Fast Computers Closer To Reality

Discovery Brings New Type Of Fast Computers Closer To Reality

  1:10:00 AM    Science Lover

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Physicists at UC San Diego have successfully created speedy integrated circuits with particles called “excitons” that operate at commercially cold temperatures, bringing the possibility of a new type of extremely fast computer based on excitons closer to reality.

Alex High and Aaron Hammack adjust the optics in their UCSD lab. (Credit: Image courtesy of University of California - San Diego)

  
Their discovery, detailed this week in the advance online issue of the journal Nature Photonics, follows the team’s demonstration last summer of an integrated circuit—an assembly of transistors that is the building block for all electronic devices—capable of working at 1.5 degrees Kelvin above absolute zero. That temperature, equivalent to minus 457 degrees Fahrenheit, is not only less than the average temperature of deep space, but achievable only in special research laboratories.

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Happy Birthday Google! ... Or Is it Goog11e?

Happy Birthday Google! ... Or Is it Goog11e?

  12:28:00 PM    Science Lover

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Giant Search Engine Celebrates 'When People Feel Like Having Cake'
Why does "Google" have two "l"s in its name today?

Mousing over the altered logo "Googlle" -- or is it "Goog11e"? -- reveals the alt text, "Google's 11th Birthday," a milestone Google is celebrating this month.


So is today the actual birthday? That may not be quite so simple to nail down.

The corporate history says Google has sometimes marked both Sept. 7 and Sept. 27 -- today -- as its birthday.

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Peruvian Glacial Retreats Linked To European Events Of Little Ice Age

Peruvian Glacial Retreats Linked To European Events Of Little Ice Age

  10:23:00 AM    Science Lover

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A new study that reports precise ages for glacial moraines in southern Peru links climate swings in the tropics to those of Europe and North America during the Little Ice Age approximately 150 to 350 years ago. The study, published this week in the journal Science, "brings us one step closer to understanding global-scale patterns of glacier activity and climate during the Little Ice Age," says lead author Joe Licciardi, associate professor of Earth sciences at the University of New Hampshire. "The more we know about our recent climate past, the better we can understand our modern and future climate."

University of New Hampshire master's student Jean Taggart '09, coauthor of a new study published in this week's Science, takes samples from a glacial moraine in southern Peru. (Credit: Joe Licciardi)

The study, "Holocene glacier fluctuations in the Peruvian Andes indicate northern climate linkages," was borne of a convergence of a methodological breakthrough in geochronological techniques and Licciardi's chance encounter with well-preserved glacial moraines in Peru.

On vacation in 2003, Licciardi was hiking near the well-known Inca Trail when he noticed massive, well-preserved glacial moraines – ridges of dirt and rocks left behind when glaciers recede -- along the way, about 25 kilometers from the ruins of Machu Picchu. "They very clearly mark the outlines of formerly expanded valley glaciers at various distinct times in the recent past," he says. But Licciardi, who had no geologic tools with him at the time, did not take any samples.

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Ancestral Populations Of India And Relationships To Modern Groups Revealed

Ancestral Populations Of India And Relationships To Modern Groups Revealed

  10:55:00 AM    Science Lover

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In a study published in the September 24th issue of Nature, an international team describes how they harnessed modern genomic technology to explore the ancient history of India, the world's second most populous nation.

A map showing the groups across India included in the Nature study. 

(Credit: Photo courtesy of D. Reich, K. Thangaraj, N. Patterson, A. Price and L. Singh)

The new research reveals that nearly all Indians carry genomic contributions from two distinct ancestral populations. Following this ancient mixture, many groups experienced periods of genetic isolation from each other for thousands of years. The study, which has medical implications for people of Indian descent, was led by scientists at the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad, India together with US researchers at Harvard Medical School, the Harvard School of Public Health and the Broad Institute of Harvard and MIT.

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How We Know A Dog Is A Dog: Concept Acquisition In The Human Brain

How We Know A Dog Is A Dog: Concept Acquisition In The Human Brain

  10:35:00 AM    Science Lover

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A new study explores how our brains synthesize concepts that allow us to organize and comprehend the world. The research, published by Cell Press in the September 24th issue of the journal Neuron, uses behavioral and neuroimaging techniques to track how conceptual knowledge emerges in the human brain and guides decision making.

Although two dogs can look very different, the human brain recognizes them as particular instances of the concept of a dog. (Credit: iStockphoto/Annette Wiechmann)







The ability to use prior knowledge when dealing with new situations is a defining characteristic of human intelligence. This is made possible through the use of concepts, which are formed by abstracting away the common essence from multiple distinct but related entities. "Although a Poodle and a Golden Retriever look very different from each other, we can easily appreciate their similar attributes because they can be recognized as instances of a particular concept, in this case a dog," explains lead study author, Dr. Dharshan Kumaran from the Wellcome Trust Centre for Neuroimaging at University College London.

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Invading Black Holes Explain Cosmic Flashes

Invading Black Holes Explain Cosmic Flashes

  1:15:00 AM    Science Lover

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Black holes are invading stars, providing a radical explanation to bright flashes in the universe that are one of the biggest mysteries in astronomy today.

Artist's concept: In the center of a swirling whirlpool of hot gas is likely a 

beast that has never been seen directly: a black hole. 

(Credit: A. Hobart, CXC)

The flashes, known as gamma ray bursts, are beams of high energy radiation – similar to the radiation emitted by explosions of nuclear weapons – produced by jets of plasma from massive dying stars.

The orthodox model for this cosmic jet engine involves plasma being heated by neutrinos in a disk of matter that forms around a black hole, which is created when a star collapses.

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Changes In Earth's Ozone Layer Predicted To Increase UV Radiation In Tropics And Antarctica

Changes In Earth's Ozone Layer Predicted To Increase UV Radiation In Tropics And Antarctica

  1:01:00 AM    Science Lover

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Physicists at the University of Toronto have discovered that changes in the Earth’s ozone layer due to climate change will reduce the amount of ultraviolet (UV) radiation in northern high latitude regions such as Siberia, Scandinavia and northern Canada. Other regions of the Earth, such as the tropics and Antarctica, will instead face increasing levels of UV radiation.

Physicists have discovered that changes in the Earth's ozone layer due to climate change 

will increase the amount of ultraviolet radiation hitting the tropics and Antarctica. 

(Credit: iStockphoto/Inga Ivanova)

“Climate change is an established fact, but scientists are only just beginning to understand its regional manifestations,” says Michaela Hegglin, a postdoctoral fellow in the Department of Physics, and the lead author of the study published in Nature Geoscience on September 6.

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Earth-like rocky planet found outside solar system

Earth-like rocky planet found outside solar system

  10:56:00 PM    Science Lover

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Astronomers have finally found a place outside our solar system where there's a firm place to stand - if only it weren't so broiling hot.

Image by Royalty-free image collection via Flickr

As scientists search the skies for life elsewhere, they have found more than 300 planets outside our solar system. But they all have been gas balls or can't be proven to be solid. Now a team of European astronomers has confirmed the first rocky extra solar planet.

Scientists have long figured that if life begins on a planet, it needs a solid surface to rest on, so finding one elsewhere is a big deal.

"We basically live on a rock ourselves,"' said co-discoverer Artie Hartzes, director of the Thuringer observatory in Germany. "It's as close to something like the Earth that we've found so far. It's just a little too close to its sun."

So close that its surface temperature is more than 3,600 degrees Fahrenheit, too toasty to sustain life. It circles its star in just 20 hours, zipping around at 466,000 mph. By comparison, Mercury, the planet nearest our sun, completes its solar orbit in 88 days.

"It's hot, they're calling it the lava planet," Hartzes said. This is a major discovery in the field of trying to find life elsewhere in the universe, said outside expert Alan Boss of the Carnegie Institution. It was the buzz of a conference on finding an Earth-like planet outside our solar system, held in Barcelona, Spain, where the discovery was presented on Wednesday morning. The find is also being published in the journal Astronomy and Astrophysics.

The planet is called Corot-7b. It was first discovered earlier this year. European scientists then watched it dozens of times to measure its density to prove that it is rocky like Earth. It's in our general neighborhood, circling a star in the winter sky about 500 light-years away. Each light-year is about 6 trillion miles.

Four planets in our solar system are rocky: Mercury, Venus, Earth and Mars.

In addition, the planet is about as close to Earth in size as any other planet found outside our solar system. Its radius is only one-and-a-half times bigger than Earth's and it has a mass about five times the Earth's.

Now that another rocky planet has been found so close to its own star, it gives scientists more confidence that they'll find more Earth-like planets farther away, where the conditions could be more favorable to life, Boss said.

"The evidence is becoming overwhelming that we live in a crowded universe," Boss said.

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Molecular Evidence Supports Key Tenet Of Darwin's Evolution Theory

Molecular Evidence Supports Key Tenet Of Darwin's Evolution Theory

  11:35:00 AM    Science Lover

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An international team of researchers, including Monash University biochemists, has discovered evidence at the molecular level in support of one of the key tenets of Darwin's theory of evolution.

Artist's rendering of a human cell. As a model system, the research focused on one specific molecular machine, the TIM complex, which transports proteins into mitochondria. Mitochondria are a compartment of human cells that serve as the energy-producing 'powerhouses'. At a very early stage in evolution, mitochondria were derived from bacteria that lived within the first eukaryotic cells. 

(Credit: iStockphoto/Gary Caviness)

Monash University's Professor Trevor Lithgow said the breakthrough, funded by the Australian Research Council and published recently in the journal Proceedings of the National Academy of Sciences, provides a blueprint for a general understanding of the evolution of the "machinery" of our cells.

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Fotobounce

Fotobounce

  1:09:00 AM    Science Lover

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A simple way to automatically tag all your photos and upload them to Facebook or Flickr; and an even easier way to download entire albums of your friends’ photos!

Today’s software will appeal to those who use online photo-sharing services to upload their own images or check out a friend’s photographs. Fotobounce has two major purposes: uploading pictures for your friends to see, and downloading their albums quickly and easily.

AUTO-TAGGING THROUGH FACE RECOGNITION

When it comes to online photo-sharing services like Photobucket, Flickr and Picasa, the most annoying aspect of the whole uploading process is tagging. You have to assign meaningful ‘tags’ to your images to make sure someone can share your album easily for them, throw up relevant results from other people’s albums and generally help out in the image navigation.

Now, when it comes to albums of family and friends, you generally have a handful names cropping up in over 200 photos at a time. Wouldn’t it be easier if the software just knew who was in which picture and named them accordingly?

Well, that’s exactly what Fotobounce claims to do. It boasts of having smart facial recognition algorithms that can scan your pictures for faces and tag them accordingly. And the rate is quite impressive too, with the software developers saying it can churn out 1,000 photos in approximately an hour.

And once you are done, the program automatically uploads all the images to your Flick or Facebook account. We didn’t try this out, but if it works as promised, it can’t get any better!

BULK DOWNLOADING

We’ve all been in this situation: You go on a trip with a friend or to a function and he/she had the camera. Of course, you always want a copy of the pictures for yourself. The friend uploads the photos to his/her Facebook or Flickr account and then you spend hours painfully downloading each image individually.

Next time you find yourself in such a predicament, simply fire up Fotobounce and point it to the friend’s album. The software will automatically download all the images in an album to your local hard disk and save you a lot of time and energy. Nice!

Rating: 4.5/

Download: http://fotobounce.com/index.php

Size: 15.2MB

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Star-shaped Cells In Brain Help With Learning

Star-shaped Cells In Brain Help With Learning

  3:54:00 PM    Science Lover

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Every movement and every thought requires the passing of specific information between networks of nerve cells. To improve a skill or to learn something new entails more efficient or a greater number of cell contacts. Scientists at the Max Planck Institute of Neurobiology in Martinsried can now show, together with an international team of researchers, that certain cells in the brain, the astrocytes, actively influence this information exchange.

Some contact points between nerve cells (red) are surrounded by star-shaped cells known as astrocytes (green). It is now shown that via ephrinA3/EphA4 interactions, astrocytes influence the communication between nerve cells by removing the transmitter molecule glutamate. 

This so far unknown activity also has implications for the ability to learn. 

(Credit: Max Planck Institute of Neurobiology / Schorner, Klein & Paixão)

Until now, astrocytes were thought to have their main role in the development and nutrition of the brain's nerve cells. The new findings improve our comprehension of how the brain learns and remembers. They could also aid in the basic research of diseases such as epilepsy and the amyotrophic lateral sclerosis (ALS).
To live is to learn: Even fruit flies can learn to avoid detrimental odors and also in humans, most abilities are based on what we learn through practice and experience. Thus we are able to perform both fundamental processes such as walking and speaking and also master complex tasks such as logical reasoning and social interactions.

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Carbon Nanotubes Could Make Efficient Solar Cells

Carbon Nanotubes Could Make Efficient Solar Cells

  1:37:00 PM    Science Lover

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Using a carbon nanotube instead of traditional silicon, Cornell researchers have created the basic elements of a solar cell that hopefully will lead to much more efficient ways of converting light to electricity than now used in calculators and on rooftops.

In a carbon nanotube-based photodiode, electrons (blue) and holes (red) - the positively charged areas where electrons used to be before becoming excited - release their excess energy to efficiently create more electron-hole pairs when light is shined on the device. (Credit: Nathan Gabor)

The researchers fabricated, tested and measured a simple solar cell called a photodiode, formed from an individual carbon nanotube. Reported online Sept. 11 in the journal Science, the researchers -- led by Paul McEuen, the Goldwin Smith Professor of Physics, and Jiwoong Park, assistant professor of chemistry and chemical biology -- describe how their device converts light to electricity in an extremely efficient process that multiplies the amount of electrical current that flows. This process could prove important for next-generation high efficiency solar cells, the researchers say.

"We are not only looking at a new material, but we actually put it into an application -- a true solar cell device," said first author Nathan Gabor, a graduate student in McEuen's lab.

The researchers used a single-walled carbon nanotube, which is essentially a rolled-up sheet of graphene, to create their solar cell. About the size of a DNA molecule, the nanotube was wired between two electrical contacts and close to two electrical gates, one negatively and one positively charged. Their work was inspired in part by previous research in which scientists created a diode, which is a simple transistor that allows current to flow in only one direction, using a single-walled nanotube. The Cornell team wanted to see what would happen if they built something similar, but this time shined light on it.

Shining lasers of different colors onto different areas of the nanotube, they found that higher levels of photon energy had a multiplying effect on how much electrical current was produced.

Further study revealed that the narrow, cylindrical structure of the carbon nanotube caused the electrons to be neatly squeezed through one by one. The electrons moving through the nanotube became excited and created new electrons that continued to flow. The nanotube, they discovered, may be a nearly ideal photovoltaic cell because it allowed electrons to create more electrons by utilizing the spare energy from the light.

This is unlike today's solar cells, in which extra energy is lost in the form of heat, and the cells require constant external cooling.

Though they have made a device, scaling it up to be inexpensive and reliable would be a serious challenge for engineers, Gabor said.

"What we've observed is that the physics is there," he said.

The research was supported by Cornell's Center for Nanoscale Systems and the Cornell NanoScale Science and Technology Facility, both National Science Foundation facilities, as well as the Microelectronics Advanced Research Corporation Focused Research Center on Materials, Structures and Devices. Research collaborators also included Zhaohui Zhong, of the University of Michigan, and Ken Bosnick, of the National Institute for Nanotechnology at University of Alberta.

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A robot that can take decisions

A robot that can take decisions

  10:02:00 PM    Science Lover

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Robots that can make their own decisions have so far been confined to science fiction movies, but a child sized figure with big eyes and a white face is trying hard to turn fiction into reality.

Its name is iCub and scientists are hoping it will learn how to adapt its behavior to changing circumstances, offering new insights into the development of human consciousness.

Six versions of the iCub exist in laboratories across Europe, where scientists are painstakingly tweaking its electronic brain to make it capable of learning, just like a human child.

"Our goal is to really understand something that is very human - the ability to cooperate, to understand what somebody else wants us to do, to be able to get aligned with them and work together," said research director Peter Ford Dominey.

iCub is about 1 meter high, with an articulated trunk, arms and legs made up of intricate electronic circuits. It has a white face with the hint of a nose and big round eyes that can see and follow moving objects.

"Shall we play the old game or play a new one?" iCub asked Dominey during a recent experiment at a laboratory in Lyon, in southeastern France. Its voice was robotic, unsurprisingly, though it did have the intonation of a person asking a question. The "game" consisted of one person picking up a box, revealing a toy that was placed underneath. Then another person picked up the toy, before putting it down again. Finally, the first person put the box back down, on top of the toy.

Having watched two humans perform this action, iCub was able to join in the fun.

"The robot is demonstrating that it can change roles. It can play the role of either the first person in the interaction or the second," said Dominey, who receives European Union funding for his work with iCub.

"These robots will be a huge tool for analytical philosophy and philosophy of mind," said Dominey, whose background is in computational neuroscience - in layman's terms, building computer models for different brain functions.

Dominey said after years of research he had understood that such models needed to be "unleashed into the world" and given vision and motor control in order to interact with humans. "Is perception consciousness? The ability to understand that somebody has a goal, is that consciousness?" he asked. "These kinds of questions, we will be able to ask with much more precision because we can have a test bed, this robot, or zombie, that we can use to implement things," he said, describing working with iCub as "an outstanding pleasure."

In the short term, iCub could be used in hospitals to help patients in need of physiotherapy by playing games with them. In the longer term, iCub could gain enough autonomy to help around the house, making its own assessments of needs.

"People have their habits, loading their dishwasher, putting away their dishes. The goal is that the robot can become like a helper, just like a polite apprentice visitor would come into your house and begin to help you," said Dominey.

Anyone looking to cut down on their household chores will need to be patient, however. "It won't be for tomorrow. It's maybe in the next decade we will begin to see this kind of thing," said the scientist.

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Nanoelectronic Transistor Combined With Biological Machine Could Lead To Better Electronics

Nanoelectronic Transistor Combined With Biological Machine Could Lead To Better Electronics

  9:44:00 PM    Science Lover

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If artificial devices could be combined with biological machines, laptops and other electronic devices could get a boost in operating efficiency.

An artist's representation of a nanobioelectronic device incorporating alamethycin biological pore. In the core of the device is a silicon nanowire (grey), covered with a lipid bilayer (blue). The bilayer incorporates bundles of alamethicin molecules (purple) that form pore channels in the membrane. Transport of protons though these pore channels changes the current through the nanowire. (Credit: Image by Scott Dougherty, LLNL)

Lawrence Livermore National Laboratory researchers have devised a versatile hybrid platform that uses lipid-coated nanowires to build prototype bionanoelectronic devices.

Mingling biological components in electronic circuits could enhance biosensing and diagnostic tools, advance neural prosthetics such as cochlear implants, and could even increase the efficiency of future computers.

While modern communication devices rely on electric fields and currents to carry the flow of information, biological systems are much more complex. They use an arsenal of membrane receptors, channels and pumps to control signal transduction that is unmatched by even the most powerful computers. For example, conversion of sound waves into nerve impulses is a very complicated process, yet the human ear has no trouble performing it.

“Electronic circuits that use these complex biological components could become much more efficient,” said Aleksandr Noy, the LLNL lead scientist on the project.

While earlier research has attempted to integrate biological systems with microelectronics, none have gotten to the point of seamless material-level incorporation.

“But with the creation of even smaller nanomaterials that are comparable to the size of biological molecules, we can integrate the systems at an even more localized level,” Noy said.

To create the bionanoelectronic platform the LLNL team turned to lipid membranes, which are ubiquitous in biological cells. These membranes form a stable, self-healing,and virtually impenetrable barrier to ions and small molecules.

“That's not to mention that these lipid membranes also can house an unlimited number of protein machines that perform a large number of critical recognition, transport and signal transduction functions in the cell,” said Nipun Misra, a UC Berkeley graduate student and a co-author on the paper.

Julio Martinez, a UC Davis graduate student and another co-author added: “Besides some preliminary work, using lipid membranes in nanoelectronic devices remains virtually untapped.”

The researchers incorporated lipid bilayer membranes into silicon nanowire transistors by covering the nanowire with a continuous lipid bilayer shell that forms a barrier between the nanowire surface and solution species.

“This 'shielded wire' configuration allows us to use membrane pores as the only pathway for the ions to reach the nanowire,” Noy said. “This is how we can use the nanowire device to monitor specific transport and also to control the membrane protein.”

The team showed that by changing the gate voltage of the device, they can open and close the membrane pore electronically.

The research appears Aug. 10 in the online version of the Proceedings of the National Academy of Sciences.

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Lasers Generate Underwater Sound: Potential For Naval And Commercial Underwater Acoustic Applications

Lasers Generate Underwater Sound: Potential For Naval And Commercial Underwater Acoustic Applications

  9:34:00 PM    Science Lover

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Scientists at the Naval Research Laboratory are developing a new technology for use in underwater acoustics. The new technology uses flashes of laser light to remotely create underwater sound. The new acoustic source has the potential to expand and improve both Naval and commercial underwater acoustic applications, including undersea communications, navigation, and acoustic imaging.

Scattered light from a 532 nm laser pulse can be seen as it enters the water in the Salt Water Tank Facility, and ionizes a small volume of water for acoustic generation. Air bubblers and controlled water and air temperatures can create ocean-like conditions in the laboratory. (Credit: Image courtesy of Naval Research Laboratory)

Dr. Ted Jones, a physicist in the Plasma Physics Division, is leading a team of researchers from the Plasma Physics, Acoustics, and Marine Geosciences Divisions in developing this acoustic source.

Efficient conversion of light into sound can be achieved by concentrating the light sufficiently to ionize a small amount of water, which then absorbs laser energy and superheats. The result is a small explosion of steam, which can generate a 220 decibel pulse of sound. Optical properties of water can be manipulated with very intense laser light to act like a focusing lens, allowing nonlinear self-focusing (NSF) to take place.

In addition, the slightly different colors of the laser, which travel at different speeds in water due to group velocity dispersion (GVD), can be arranged so that the pulse also compresses in time as it travels through water, further concentrating the light. By using a combination of GVD and NSF, controlled underwater compression of optical pulses can be attained.

The driving laser pulse has the ability to travel through both air and water, so that a compact laser on either an underwater or airborne platform can be used for remote acoustic generation. Since GVD and NSF effects are much stronger in water than air, a properly tailored laser has the ability to travel many hundreds of meters through air, remaining relatively unchanged, then quickly compress upon entry into the water. Atmospheric laser propagation is useful for applications where airborne lasers produce underwater acoustic signals without any required hardware in the water, such as undersea communications from aircraft.

Also, commercially available, high-repetition-rate pulsed lasers, steered by a rapidly movable mirror, can generate arbitrary arrays of phased acoustic sources. On a compact underwater platform with an acoustic receiver, such a setup can rapidly generate oblique-angle acoustic scattering data, for imaging and identifying underwater objects. This would be a significant addition to traditional direct backscattering acoustic data.

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Hydrogen Storage Gets New Hope

Hydrogen Storage Gets New Hope

  9:28:00 PM    Science Lover

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A new method for “recycling” hydrogen-containing fuel materials could open the door to economically viable hydrogen-based vehicles.

Ammonia borane (AB) is a potential hydrogen releasing fuel. In this Los Alamos National Laboratory graphic, the AB would be used on-board the vehicle to run a fuel cell. Once hydrogen is released, the AB could then be regenerated and reused. In the scheme shown,
the recycle of dehydrogenated fuel back into AB would take place off-board the vehicle.
(Credit: Image courtesy of DOE/Los Alamos National Laboratory)

In an article appearing in Angewandte Chemie, Los Alamos National Laboratory and University of Alabama researchers working within the U.S. Department of Energy’s Chemical Hydrogen Storage Center of Excellence describe a significant advance in hydrogen storage science.

Hydrogen is in many ways an ideal fuel for transportation. It is abundant and can be used to run a fuel cell, which is much more efficient than internal combustion engines. Its use in a fuel cell also eliminates the formation of gaseous byproducts that are detrimental to the environment.

For use in transportation, a fuel ideally should be lightweight to maintain overall fuel efficiency and pack a high energy content into a small volume. Unfortunately, under normal conditions, pure hydrogen has a low energy density per unit volume, presenting technical challenges for its use in vehicles capable of travelling 300 miles or more on a single fuel tank—a benchmark target set by DOE.

Consequently, until now, the universe’s lightest element has been considered by some as a lightweight in terms of being a viable transportation fuel.

In order to overcome some of the energy density issues associated with pure hydrogen, work within the Chemical Hydrogen Storage Center of Excellence has focused on using a class of materials known as chemical hydrides. Hydrogen can be released from these materials and potentially used to run a fuel cell. These compounds can be thought of as “chemical fuel tanks” because of their hydrogen storage capacity.

Ammonia borane is an attractive example of a chemical hydride because its hydrogen storage capacity approaches a whopping 20 percent by weight. The chief drawback of ammonia borane, however, has been the lack of energy-efficient methods to reintroduce hydrogen back into the spent fuel once it has been released. In other words, until recently, after hydrogen release, ammonia borane couldn’t be adequately recycled.

Los Alamos researchers have been working with University of Alabama colleagues on developing methods for the efficient recycling of ammonia borane. The research team made a breakthrough when it discovered that a specific form of dehydrogenated fuel, called polyborazylene, could be recycled with relative ease using modest energy input. This development is a significant step toward using ammonia borane as a possible energy carrier for transportation purposes.

“This research represents a breakthrough in the field of hydrogen storage and has significant practical applications,” said Dr. Gene Peterson, leader of the Chemistry Division at Los Alamos. “The chemistry is new and innovative, and the research team is to be commended on this excellent achievement.”

The Chemical Hydrogen Storage Center of Excellence is one of three Center efforts funded by DOE. The other two focus on hydrogen sorption technologies and storage in metal hydrides. The Center of Excellence is a collaboration between Los Alamos, Pacific Northwest National Laboratory, and academic and industrial partners.

Referring to the work described in the Angewandte Chemie article, Los Alamos researcher John Gordon, corresponding author for the paper, stated, “Collaboration encouraged by our Center model was responsible for this breakthrough. At the outset there were myriad potential reagents with which to attempt this chemistry.”

“The predictive calculations carried out by University of Alabama professor Dave Dixon’s group were crucial in guiding the experimental work of Los Alamos postdoctoral researcher Ben Davis,” Gordon added. “The excellent synergy between these two groups clearly enabled this advance.”

The research team currently is working with colleagues at The Dow Chemical Company, another Center partner, to improve overall chemical efficiencies and move toward large-scale implementation of hydrogen-based fuels within the transportation sector.

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That Late-night Snack: Worse Than You Think

That Late-night Snack: Worse Than You Think

  9:12:00 PM    Science Lover

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Eat less, exercise more. Now there is new evidence to support adding another "must" to the weight-loss mantra: eat at the right time of day.

Eating at irregular times -- the equivalent of the middle of the night for humans,
when the body wants to sleep -- influences weight gain, a new study has found.
(Credit: iStockphoto/Curt Pickens)

A Northwestern University study has found that eating at irregular times -- the equivalent of the middle of the night for humans, when the body wants to sleep -- influences weight gain. The regulation of energy by the body's circadian rhythms may play a significant role. The study is the first causal evidence linking meal timing and increased weight gain.

"How or why a person gains weight is very complicated, but it clearly is not just calories in and calories out," said Fred Turek, professor of neurobiology and physiology in the Weinberg College of Arts and Sciences and director of the Center for Sleep and Circadian Biology. "We think some factors are under circadian control. Better timing of meals, which would require a change in behavior, could be a critical element in slowing the ever-increasing incidence of obesity."

The findings could have implications for developing strategies to combat obesity in humans, as the United States and the world battle what has been called an "obesity epidemic." More than 300 million adults worldwide are obese, including more than a third of American adults.

Details of the obesity study, which was led by Turek, will be published online Sept. 3 by the journal Obesity.

"One of our research interests is shift workers, who tend to be overweight," said lead author Deanna M. Arble, a doctoral student in Turek's lab. "Their schedules force them to eat at times that conflict with their natural body rhythms. This was one piece of evidence that got us thinking -- eating at the wrong time of day might be contributing to weight gain. So we started our investigation with this experiment."

Simply modifying the time of feeding alone can greatly affect body weight, the researchers found. Mice that were fed a high-fat diet during normal sleeping hours gained significantly more weight (a 48 percent weight increase over their baseline) than mice eating the same type and amount of food during naturally wakeful hours (a 20 percent increase over their baseline). There was no statistical difference between the two groups regarding caloric intake or the amount of activity.

Over a period of six weeks, both groups of mice were allowed to eat as much high-fat diet as they wanted during their daily 12-hour feeding phase. (Much like many humans, mice have a preference for high-fat food.) Since mice are nocturnal, the 12-hour feeding phase was during the day for those fed during normal sleeping hours and during the night for those fed during naturally wakeful hours. Food was not provided during the other 12 hours of their day.

Our circadian clock, or biological timing system, governs our daily cycles of feeding, activity and sleep, with respect to external dark and light cycles. Recent studies have found the body's internal clock also regulates energy use, suggesting the timing of meals may matter in the balance between caloric intake and expenditure.

The researchers next plan to investigate the molecular mechanisms behind their observation that eating at the "wrong" time can lead to weight gain.

In addition to Turek and Arble, other authors of the paper are Joseph Bass, Aaron D. Laposky and Martha H. Vitaterna, all from Northwestern.

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