amudu

Thursday, December 22, 2011

Habit formation is enabled by gateway to brain cells

Drs. Joe Z. Tsien (left) and Lei Phillip Wang have identified a receptor on dopamine neurons that is essential to habit formation.
Credit: Phil Jones/GHSU photographer

A brain cell type found where habits are formed and movement is controlled has receptors that work like computer processors to translate regular activities into habits, researchers report.

"Habits, for better or worse, basically define who we are," said Dr. Joe Z. Tsien, Co-Director of the Brain & Behavior Discovery Institute at Georgia Health Sciences University. Habits also provide mental freedom and flexibility by enabling many activities to be on autopilot while the brain focuses on more urgent matters, he said.

Research published in the journal Neuron shows that NMDA receptors on dopamine neurons in the brain's basal ganglia are essential to habit formation. These receptors function like gateways to the brain cells, letting in electrically charged ions to increase the activity and communication of neurons. Their pivotal role reminds neuroscientist Dr. Lei Phillip Wang of a computer's central processing unit. "The NMDA receptor is a commander, which is why it's called a master switch for brain cell connectivity," said Wang, the study's first author.

To determine their role in habit formation, GHSU researchers used a genetic trick to selectively disable the NMDA receptors on dopamine neurons and found, for example, mice could be trained to push a lever for food without it becoming an automatic response. If they were full, they wouldn't push the lever. But just as humans can't refrain from flipping a light switch during a power outage, satiated mice with receptors could not pass up the lever.

When they compared the firing of the dopamine neurons in regular versus the mutant mouse, they found a dramatic spike in response to a cue that signals food in the normal mouse and a significantly dampened one in the mutant, Wang said. "We think this reduced response is probably sufficient for other types of learning, but not for habit learning," he said.

The finding that the receptors are critical to turning learned behavior into a habit provides new direction for therapy to better treat diseases such as Parkinson's, which in addition to the hallmark shaking, causes the loss of some old habits and impedes the ability to make new ones. "When Parkinson's disease begins to kick in, your memory of habits begins to go away, often before the uncontrolled movement becomes prominent," Tsien said.

It also opens the door to speeding up the process of forming good habits and, possibly, selectively removing bad ones such as drug addiction or smoking since the same circuits are seemingly involved in both.

"If you know cell circuits controlling a specific habit, it puts you in a better position to devise strategies to hit different points and selectively facilitate the formation of a good habit and maybe even reverse a bad one," Tsien said.

The fact that their mutant mice did not have motor deficits like Parkinson's patients fits with the fact that a precursor to dopamine can reduce motor symptoms in these patients, at least for a while, but does little to help cognitive function, Tsien said. Previous research indicating that just dousing a brain with dopamine doesn't rescue the ability to form habits led GHSU researchers to pursue the more sophisticated regulation that must enable habit formation.

"Dopamine neurons regulate circuits all over the brain but they need to be regulated too," Tsien said. "The questions become how and whether regulation of dopamine neurons is important. Our study shows it's important and it's through the NMDA receptors." Part of that regulation includes proper sequencing: so a habit plays out the same way every time, Tsien noted, much like standard lettering on a keyboard enables typing rather than confusion.

Dopamine is a chemical that helps brain cells communication. Glutamate, another neurotransmitter, brings information to the dopamine neurons to enable learning and memory but the neurons must travel through the gateway NMDA receptors to get properly categorized, the researchers noted.

As pervasive and efficient as habits are, these automatic memories that enable driving a car or typing, are not well studied or understood. "We tend not to pay attention to them because they are so spontaneous and automatic," said Tsien. GHSU scientists want to better understand why, for example, certain actions move from purposeful acts to automatic ones. They also want to know if one way NMDA receptors work is by causing dopamine neurons to release dopamine at the right time, amount and places in the brain.

Habits are generally characterized as procedural rather than declarative memories, such as those of events, people and places, things that require active thought. Declarative memories are more typically lost in Alzheimer's while habits often remain intact, at least for a while.

Provided by Georgia Health Sciences University

"Habit formation is enabled by gateway to brain cells." December 21st, 2011. http://medicalxpress.com/news/2011-12-habit-formation-enabled-gateway-brain.html

Posted by
Robert Karl Stonjek

How the brain cell works: A dive into its inner network

At the core of the new imaging technology is the phenomenon known as FRET that occurs only when two fluorescently tagged molecules come within the distance of eight nanometer or less. Detecting the FRET serves as a proxy for the two proteins X and Y associating with each other within a living cell.
Credit: Credit: A. Chiba, University of Miami

University of Miami biology professor Akira Chiba is leading a multidisciplinary team to develop the first systematic survey of protein interactions within brain cells. The team is aiming to reconstruct genome-wide in situ protein-protein interaction networks (isPIN) within the neurons of a multicellular organism. Preliminary data were presented at the American Society for Cell Biology annual meeting, December 3 through 7, 2011, in Denver, Colorado.

"This work brings us closer to understanding the mechanics of molecules that keep us functioning," says Chiba, principal investigator of this project. "Knowing how our cells work will improve medicine. Most importantly, we will gain a better understanding of what life is at the molecular level."

Neurons are the cells that are mainly responsible for signaling in the brain. Like all other cells, each neuron produces millions of individual proteins that associate with one another and form a complex communication network. Until recently, observing these protein-protein interactions had not been possible due to technical difficulties. Individual proteins are small and typically less than 10 nm (nanometer) in diameter. Yet, this nano-scale distance was considered to be off-limits even with super-resolution microscopy.

Now, Chiba and his collaborators have developed a novel methodology to examine interaction of individual proteins in the fruit fly – the model organism of choice for this project. The researchers are creating genetically engineered insects that are capable of expressing over 500 fluorescently-tagged assorted proteins, two at a time. The fluorescent tags make it possible to visualize the exact spot where a given pair of proteins associates with each other.

The team utilizes a custom- built 3D FLIM (fluorescent lifetime imaging microscopy) system to quantify this association event within the cells of a live animal. FLIM shows the location and time of such protein interaction, providing the data that allow creation of a point-by-point map of protein-protein interactions.

The pilot phase of this multidisciplinary project is being funded by the National Institutes of Health. It employs advanced genetics, molecular imaging technology and high-performance computation, among other fields. "Collaborating fluorescent chemistry, laser optics and artificial intelligence, my team is working in the 'jungle' of the molecules of life within the living cells," Chiba says. "This is a new kind of ecology played out at the scale of nanometers—creating a sense of deja vu 80 years after the birth of modern ecology."

At present, the researchers still need to extrapolate from data obtained in test tubes. In the future, they will begin to visualize directly how the individual proteins interact with one another in their 'native environment,' which are the cells in our body.

Provided by University of Miami

"How the brain cell works: A dive into its inner network." December 21st, 2011. http://www.physorg.com/news/2011-12-brain-cell-network.html

Posted by
Robert Karl Stonjek

தமிழ் மாதங்களும் அதன் செந்தமிழ் பெயர்களும்.

THREE PROFESSIONS IN HIGH DEMAND

Even in this economy there are some jobs which are difficult to fill. These 3 professionals are in high demand and might be tough to get on your staff. If you are currently looking to hire someone in this field you may want to start searching early!

INC shares…

Hiring the best of the best is an absolute must if you are going to build a successful company. You will need to be prepared to compete against big companies with deep pockets and other up-and-coming startups that also have blue chip investors and a game-changing idea.

So, what are the most competitive areas for talent these days? Here’s a look:

Software Engineers and Web Developers

The demand for top-tier engineering talent sharply outweighs the supply in almost every market especially in San Francisco, New York, and Boston. This is a major, major pain point and problem that almost every company is facing, regardless of the technology “stack” their engineers are working on.

Creative Design and User Experience

After engineers, the biggest challenge for companies is finding high-quality creative design and user-experience talent. Since almost every company is trying to create a highly compelling user experience that keeps people engaged with their product, it is tough to find people who have this type of experience (especially with mobile devices including tablets) and a demonstrated track record of success.

Product Management

It is always helpful for an early-stage company to hire someone who has very relevant and specific experience in your industry. This is especially true for product management, since the person in this role will interface with customers and define the product strategy and use cases. However, be prepared, as it will be a challenge to find people with experience in these high-growth industries: consumer web, e-commerce, mobile, software as a service, and cloud computing.

Get the full story at INC!

கி.வா. ஜகன்னாதனின் சிறப்புச் சிலேடைகள்

கர்ப்பப்பை புற்று நோய்

உடலில் உள்ள அபரிமிதமான செல்கள் தமக்குள் கட்டுப்பாடின்றி பிரிந்து, மீண்டும் வளர்ந்து அருகில் உள்ள திசுக்களில் பரவி, மீண்டும் பிரிந்து வளரும். இச் செயல் புற்று வளருவது போல இருப்பதால், இதை புற்றுநோய் என்பர். இதில் பல வகை உள்ளன. தோல் மற்றும் திசுக்களில் ஏற்படுவது “கார்சினோமா’ கேன்சர். எலும்பு, அதன் மஜ்ஜை, கொழுப்பு, தசை, ரத்தக் குழாய்களில் ஏற்படுவது, “சர்கோமா’. ரத்த அணுக்களை உற்பத்தி செய்து பரப்புவது “லூகேமியா’. நோய் எதிர்ப்பு சக்தி பகுதி செல்களில் ஏற்படுவது “லிம்போன் அன்ட் மையலோமா’ மூளை, முதுகுத் தண்டில் உள்ள திசுக்களில் ஏற்படும் செல் மாறுதல்கள் நடுநரம்பு மண்டலம், மத்திய நரம்பு மண்டலத்தில் ஏற்படுவது “மெலிக்னன்சி’ கேன்சர்.

டாக்டர் என்.விஜயலட்சுமி ராம்சங்கர்,
கேன்சர் இன்ஸ்டிடியூட், அடையாறு

Engr. சுல்தான்

Single Cell Endoscope: Researchers Use Nanophotonics for Optical Look Inside Living Cells

This schematic depicts the subcellular imaging of quantum dots in a living cell using a nanowire endoscope. (Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory) Science Daily — An endoscope that can provide high-resolution optical images of the interior of a single living cell, or precisely deliver genes, proteins, therapeutic drugs or other cargo without injuring or damaging the cell, has been developed by researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab). This highly versatile and mechanically robust nanowire-based optical probe can also be applied to biosensing and single-cell electrophysiology.

A team of researchers from Berkeley Lab and the University of California (UC) Berkeley attached a tin oxide nanowire waveguide to the tapered end of an optical fibre to create a novel endoscope system. Light travelling along the optical fibre can be effectively coupled into the nanowire where it is re-emitted into free space when it reaches the tip. The nanowire tip is extremely flexible due to its small size and high aspect ratio, yet can endure repeated bending and buckling so that it can be used multiple times.

"By combining the advantages of nanowire waveguides and fibre-optic fluorescence imaging, we can manipulate light at the nanoscale inside living cells for studying biological processes within single living cells with high spatial and temporal resolution," says Peidong Yang, a chemist with Berkeley Lab's Materials Sciences Division, who led this research. "We've shown that our nanowire-based endoscope can also detect optical signals from subcellular regions and, through light-activated mechanisms, can deliver payloads into cells with spatial and temporal specificity."

Yang, who also holds appointments with the University of California Berkeley's Chemistry Department and Department of Materials Science and Engineering, is the corresponding author of a paper in the journal Nature Nanotechnologydescribing this work titled "Nanowire-based single-cell endoscopy." Co-authoring the paper were Ruoxue Yan, Ji-Ho Park, Yeonho Choi, Chul-Joon Heo, Seung-Man Yang and Luke Lee.

Despite significant advancements in electron and scanning probe microscopy, visible light microscopy remains the workhorse for the study of biological cells. Because cells are optically transparent, they can be noninvasively imaged with visible light in three-dimensions. Also, visible light allows the fluorescent tagging and detection of cellular constituents, such as proteins, nucleic acids and lipids. The one drawback to visible light imaging in biology has been the diffraction barrier, which prevents visible light from resolving structures smaller than half the wavelength of the incident light. Recent breakthroughs in nanophotonics have made it possible to overcome this barrier and bring subcellular components into view with optical imaging systems. However, such systems are complex, expensive and, oddly enough, bulky in size.

"Previously, we had shown that subwavelength dielectric nanowire waveguides can efficiently shuttle ultraviolet and visible light in air and fluidic media," Yang says. "By incorporating one of our nanophotonic components into a simple, low-cost, bench-top fibre-optical set-up, we were able to miniaturize our endoscopic system."

To test their nanowire endoscope as a local light source for subcellular imaging, Yang and his co-authors optically coupled it to an excitation laser then waveguided blue light across the membrane and into the interiors of individual HeLa cells, the most commonly used immortalized human cell line for scientific research.

"The optical output from the endoscope emission was closely confined to the nanowire tip and thereby offered highly directional and localized illumination," Yang says. "The insertion of our tin oxide nanowire into the cell cytoplasm did not induce cell death, apoptosis, significant cellular stress, or membrane rupture. Moreover, illuminating the intracellular environment of HeLa cells with blue light using the nanoprobe did not harm the cells because the illumination volume was so small, down to the picolitre-scale."

Having demonstrated the biocompatibility of their nanowire endoscope, Yang and his co-authors next tested its capabilities for delivering payloads to specific sites inside a cell. While carbon and boron nitride nanotube-based single-cell delivery systems have been reported, these systems suffer from delivery times that range from 20-to-30 minutes, plus a lack of temporal control over the delivery process. To overcome these limitations, Yang and his co-authors attached quantum dots to the tin oxide nanowire tip of their endoscope using photo-activated linkers that can be cleaved by low-power ultraviolet radiation. Within one minute, their functionalized nanowire endoscope was able to release its quantum dot cargo into the targeted intracellular sites.

"Confocal microscopy scanning of the cell confirmed that the quantum dots were successfully delivered past the fluorescently labeled membrane and into the cytoplasm," Yang says. "Photoactivation to release the dots had no significant effect on cell viability."

The highly directional blue laser light was used to excite one of two quantum dot clusters that were located only two micrometers apart. With the tight illumination area and small separation between the light source and the dots, low background fluorescence and high imaging contrast were ensured.

"In the future, in addition to optical imaging and cargo delivery, we could also use this nanowire endoscope to electrically or optically stimulate a living cell," Yang says.

The nanowires used in these experiments were originally developed to study size-dependent novel electronic and optical properties for energy applications.

This research was supported by the DOE Office of Science and a grant from the National Institutes of Health.

பப்பாளி பழத்தின் மருத்துவ குணங்கள்

பப்பாளி பழத்தின் தாவரவியல் பெயர் காரிசிகா பாபாயா. இதன் கனிகள், விதைகள், இலைகள் என்று அனைத்துமே மருத்துவக்குணம் வாய்ந்தது.

பப்பாளி வயிற்றுக் கோளாறுக்கு மருந்தாகப் பயன்படுகிறது, செரிமானத்தை ஊக்குவிக்கிறது, பப்பாளிக் காயின் பால் வயிற்றில் உள்ள பூச்சிகளை அகற்றுகிறது.

தோலில் உள்ள மருக்கள் மற்றும் கரும்புள்ளிகளைப் போக்குகிறது. இதன் விதைகளும் பூச்சிகளை அகற்றும் மருந்து தயாரிக்க பயன்படுகிறது.

இலைகளின் சாறு காய்ச்சலைப் போக்கும் மருந்தாக பயன்படுகிறது. இதய நோயைக் குணப்படுத்தவும் பயன்படுகிறது.

பப்பாளியின் காய்களில் இருந்து பப்பைன் என்ற புரதங்களை சிதைக்கும் நொதி, கைமோபப்பைன், மாலிக் அமிலம், பெக்டின் களிகள், புரதம், சர்க்கரை, க்ரிப்டோசாந்தின், வயலா சாந்தின், கரோட்டின், அஸ்கார்பிக் அமிலம், தையமின், ரைபோபிளேவின், கார்ளப்பசமைன் போன்ற இரசாயனப் பொருட்கள் பிரித்தெடுக்கப்படுகிறது.

Shirdi Sai Baba

Wednesday, December 21, 2011

உடல் எடையை கட்டுப்படுத்தும் பியர் – ஆய்வில் தகவல்!

பியர் குடித்தால் உடல் எடை குறையும் என்று சமீபத்திய ஆய்வு ஒன்றில் தெரியவந்துள்ளது. பியரானது உடல் எடையை கட்டுப்படுத்துவதோடு, நீரிழிவு மற்றும் இதயநோய் தாக்குதலில் இருந்து பாதுகாப்பதாக அந்த ஆய்வு முடிவில் கண்டறியப்பட்டுள்ளது.
மது உடலுக்கு கேடு என்று விளம்பரம் செய்யப்படுகிறது. இன்றைய இளைய தலைமுறையினர் அதிகம் விரும்பி பருகும் உற்சாக பானமான பியர் உடல் எடையை குறைப்பதோடு நோய் தாக்குதலில் இருந்தும் பாதுகாக்கிறதாம்.

ரத்த அழுத்தம் இல்லை
ஸ்பானிஸ் நாட்டைச் சேர்ந்த ஆய்வாளர்கள் 57 வயதிற்கு மேற்பட்ட 1249 ஆண்கள் மற்றும் பெண்களிடம் ஆய்வு மேற்கொண்டனர். அதில் தினமும் மிதமான அளவு பியர் உட்கொண்டவர்கள் உடல் எடை குறைவாகவும், குண்டாகமலும் இருப்பதாக தெரிவித்தனர். அவர்களுக்கு சர்க்கரை நோய், ரத்த அழுத்தம் போன்ற நோய்கள் எதுவும் தாக்கப்படாமல் இருந்தது ஆய்வில் கண்டறியப்பட்டது.

உடல் எடை குறைகிறது
20 ஆயிரத்திற்கும் மேற்பட்ட பெண்களிடம் 13 ஆண்டுகளாக நடத்தப்பட்ட ஆய்வில் மிதமாக பியர் குடித்த பெண்களின் உடலில் கொழுப்பு சேராமல் உடல் பிட்டாக இருந்தது தெரியவந்தது. குண்டாக இருந்த பெண்கள், பியர் குடித்த பின்னர் உடல் கட்டுக்குள் வந்துள்ளதாக தெரிவித்துள்ளனர்.

இதயநோய் பாதிப்பு
அமெரிக்காவை சேர்ந்த நிபுணர்கள் ஒயின் மற்றும் பியர் குடிக்கும் 2 லட்சம் பேரிடம் ஆய்வு மேற்கொண்டனர். அவர்களில் மிதமான அளவு பியர் குடித்து வருபவர்களுக்கு இருதய நோய் பாதிப்பு குறைந்து இருந்தது. அதாவது 31 சதவீதம் பேர் இருதய நேய் பாதிப்பு ஏற்படாமல் இருந்தனர். இதற்கு ரத்தக் குழாய்களில் அடைப்பு மற்றும் நோய் ஏற்படாததே காரணம் என கூறப்படுகிறது.

அதிகம் குடித்தால் ஆபத்து
பியர் பானத்தில் அதிக அளவில் தண்ணீர் உள்ளது. இதனால் அதை குடித்தவுடன் அதில் உள்ள அல்கஹோலை உடல் குறைந்த அளவில் மட்டும் எடுத்து கொள்கிறது. இதனால் குறைந்த அளவில் பியர் குடித்தால் இருதய நோய் தாக்குதலில் இருந்து தப்பிக்க முடியும். அதே நேரத்தில் அளவுக்கு அதிகமாக குடித்தால் பாதிப்பு ஏற்படும் என மற்றொரு ஆய்வில் தெரியவந்துள்ளது.

My 10 Favorite Technologies of 2011

A year of new gadgets and wonders that greeted the world.

David Zax

Another year has come and nearly gone, leaving our technological world all the richer and more confounding. Here are 10 of the most exciting, eye-catching, or important developments to have crossed Hello World's radar in 2011.
10. The Dyson Hot
It's a new dog with an old trick: heating a room. But the Dyson Hot, which we introduced to you in September, is more than that, too: the first space heater that's downright sexy, and that calls attention to its inner workings. "I want something more expressive," Dyson told Wired at the time. "It's very easy to make something like a heater into a black box." We're glad he didn't.
9. The Smart Watch
Here's one we can't endorse just yet. But it holds immense promise. Though perpetually delayed, Meta Watch, once of Fossil, became its own company in September. A future with smartphone-like capabilities on your wrist points to an era where you rarely need to rummage in your pocket for your iPhone. We eargerly await what Meta Watch, a favored smart watch company among its test-drivers, finally brings to market.
8. The Electric DeLorean
In a year full of electric vehicle news, perhaps the electric DeLorean wasn't the most significant. But it certainly was the one that made a tech blogger smile. That most "retro-futuristic" of cars, associated with the Back to the Future franchise, truly embraced the future by finally kicking its gasoline habit. We were also excited by the wild mileage some Chevy Volt users reported, and the fact that that car was being used to green the NYPD's fleet. Oh, and never mind that fire.
7. The Nest Thermostat
If the Dyson Hot brought sexy back to space heaters, the Nest did the same for thermostats. (There's a sentence we never thought we'd write.) Reading about the Nest was one of those "what took so long?" moments--finally, a sleek, attractive, and intelligent device that does what it's supposed to do, no more, no less. And did we mention it was sexy? The Nest, which draws some of its design DNA from the iPod, also represents the encroaching Apple-ification of the household gadget.
6. The Toilet 2.0
Sometimes technologists need to get in the gutter--or the sewer. We were pleased to see the Bill and Melinda Gates Foundation flush some $40 million into toilet R&D. "We're gonna have a breakthrough in the latrines," Gates promised. With poor sanitation behind so many of the world's preventable diseases, that flushing sound is music to our ears.

5. Sony's 3-D Binocular/Camera
The sheer difficulty of classifying this device is perhaps what excites us most about it. Binoculars? An HD camera? A 3-D recording device? It's all three. By enabling humble birdwatcher to pack James Cameron-level hardware, Sony brought heavy artillery to hobbyists (and possibly voyeurs?) everywhere.
4. The E-Bike
Here was an idea that didn't get a huge amount of press, but that seems downright exciting to us: a bicycle that looks normal, but packs a little electric oomph for those brutally steep hills you may have to climb on your commute. Part bike, part electric scooter, the devices ain't cheap, running up to a couple grand. But the reward to you and your colleagues--a bike commute that doesn't leave you a complete, sweaty mess--could be well worth it.
3. The Robotic Exoskeleton
2011 was the year that the vision of a future of Iron Man-like robotic exoskeletons came more clearly into focus. The technology achieved something downright remarkable in May, when a UC Berkeley student who had been paralyzed from the waist down was able to use one such device to walk and accept his diploma.
2. The Lytro Camera
What a difference a micro-array of miniature cameras makes. Lytro, a camera start-up, redefined our notions of what a photograph--typically thought of as static--could be. Don't believe me? Just click on the background in the photo below.

1. The Not-iPads
In the last few months in particular, the non-iPad tablet market has become the most interesting and contested space to watch. There was HP's marooned TouchPad, whose fire sale kicked off a buying frenzy. There was the shockingly bargain-basement Kindle Fire, which will surely stuff Amazon's coffers even while it disappoints many users. And there was the well-reviewed Nook Tablet, arguably stronger than the Fire, but without a full-fledged media store of its own. As much as this was a year of the iPad's rise, it was the also-rans that mostly captured our attention and imagination.

Finding an End to Energy Gridlock

A new book outlines an energy strategy that might actually work.

David Rotman

In recent years, people who recognize the need to revamp our energy infrastructure have debated whether the priority should be to impose policy-driven changes immediately or to find technology breakthroughs that would radically redefine our energy sources. The answer is that we need both. And in their well-argued new book, Unlocking Energy Innovation, Richard K. Lester and David M. Hart explain not only why this is true but, perhaps more interesting, how to simultaneously begin addressing both priorities.
Transforming our energy system won't be simple or fast. Lester, head of MIT's Department of Nuclear Science and Engineering and founding director of its Industrial Performance Center, and Hart, director of the Center for Science and Technology Policy at George Mason University, describe energy innovation as occurring in three "waves." In their description, the first wave is improving energy efficiency; a second, which will have its largest impact between 2020 and 2050, will involve the deployment of low-carbon energy sources such as renewables and nuclear; and a third wave of radically new technologies, such as carbon-neutral biofuels and advanced solar technologies, will not be a significant factor until after 2050. The authors argue that we must work faster and in parallel on all these types of innovation if we are to have any chance of meeting long-term goals for slashing greenhouse-gas emissions.
It's a simple description of how energy technologies will unfold. But it will shock many that energy sources such as wind and solar are a decade away from making a large impact. It is even more sobering to realize that radically new technologies, some of which have begun appearing in the lab, might be at least 40 years from actual use.
The authors of Unlocking Energy Innovation describe four stages of energy innovation: the creation of new options; demonstration; early adoption; and the optimization of large-scale technologies. The costs associated with each are vastly different, and they increase by roughly an order of magnitude as technologies are scaled up. This analysis highlights one of the most challenging aspects of energy innovation: how to fund and select the demonstration and adoption of new technologies before they are commercially competitive. Lester and Hart call these "learning investments" and point out that they can cost billions of dollars.
Conventional wisdom among many energy experts, particularly economists, suggests that an effective energy policy will be based on supporting research and setting a price, or tax, on carbon emissions. But Lester and Hart say that such a strategy neglects to support the critical middle stages of early adoption and deployment. The problem is that new technologies cost so much a modest carbon price alone will provide few incentives to producers. So how to support these costly stages of energy innovation? Lester and Hart spend much of the book laying out a scheme that they believe might work.
The problem is complex. Specifically, it will require reforming our system of electricity generation and distribution, which is a mess after decades of partial deregulation. Though Lester and Hart readily admit that their proposals might not be the eventual solution, they do offer something that is all too rare these days: a logical strategy for tackling climate change that has both the aggressiveness needed to lower carbon dioxide emissions in the coming years and the planning needed to support the far greater changes needed by midcentury.
Of course, these days it's doubtful whether we have the political will or the consensus in place to overhaul our energy system. But despite the gridlock in Washington, that doesn't negate the need for strategic thinking about the problem. "Incremental changes won't be enough. The system is pretty badly dysfunctional," said Lester in a recent interview. "There's always a pressure to fix it immediately. So people look at the small changes that can get done in a short period of time. But we need to be setting up systems that will work over much longer periods."

Layer by Layer

With 3-D printing, manufacturers can make existing products more efficiently—and create ones that weren't possible before.

By David H. Freedman

Buildup: GE made the aircraft engine component on the left by using a laser to melt metal in precise places, beginning with the single layer seen on the right. Credit: Bob O’Connor

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The parts in jet engines have to withstand staggering forces and temperatures, and they have to be as light as possible to save on fuel. That means it's complex and costly to make them: technicians at General Electric weld together as many as 20 separate pieces of metal to achieve a shape that efficiently mixes fuel and air in a fuel injector. But for a new engine coming out next year, GE thinks it has a better way to make fuel injectors: by printing them.
To do it, a laser traces out the shape of the injector's cross-section on a bed of cobalt-chrome powder, fusing the powder into solid form to build up the injector one ultrathin layer at a time. This promises to be less expensive than traditional manufacturing methods, and it should lead to a lighter part—which is to say a better one. The first parts will go into jet engines, says Prabhjot Singh, who runs a lab at GE that focuses on improving and applying this and similar 3-D printing processes. But, he adds, "there's not a day we don't hear from one of the other divisions at GE interested in using this technology."
These innovations are at the forefront of a radical change in manufacturing technology that is especially appealing in advanced applications like aerospace and cars. The 3-D printing techniques won't just make it more efficient to produce existing parts. They will also make it possible to produce things that weren't even conceivable before—like parts with complex, scooped-out shapes that minimize weight without sacrificing strength. Unlike machining processes, which can leave up to 90 percent of the material on the floor, 3-D printing leaves virtually no waste—a huge consideration with expensive metals such as titanium. The technology could also reduce the need to store parts in inventory, because it's just as easy to print another part—or an improved version of it—10 years after the first one was made. An automobile manufacturer receiving reports of a failure in a seat belt mechanism could have a reconfigured version on its way to dealers within days.
Additive manufacturing, as 3-D printing is also known, emerged in the mid-1980s after Charles Hull invented what he called stereolithography, in which the top layer of a pool of resin is hardened by an ultraviolet laser. Various methods of 3-D printing have become popular with engineers who want to create prototypes of new designs or make a few highly customized parts: they can make a 3-D blueprint of a part in a computer-assisted design program and then get a printer to spit it out hours later. This process avoids the up-front costs, long lead times, and design constraints of conventional high-volume manufacturing techniques like injection molding, casting, and stamping. But the technology has been adapted to only a limited set of materials, and there have been questions about quality control. Building parts this way has also been slow—it can take a day or more to do what traditional manufacturing can accomplish in minutes or hours. For these reasons, 3-D printing hasn't been used for very large runs of production parts.
But now the technology is advancing far enough for production runs in niche markets such as medical devices. And it's poised to break into several larger applications over the next several years. "We've come to the point when enough critical advances are happening to make the technology truly useful in manufacturing end-use parts," says Tim Gornet, who runs the Rapid Prototyping Center at the University of Louisville.

Pressing print: This photo shows an array of metal jet-engine components printed at GE. Credit: Bob O’Connor

MAKING INROADS
Several techniques can be used to "print" a solid object layer by layer. In sintering, a thin layer of powdered metal or thermoplastic is exposed to a laser or electron beam that fuses the material into a solid in designated areas; then a new coating of powder is laid on top and the process repeated. Parts can also be built up with heated plastic or metal extruded or squirted through a nozzle that moves to create the shape of one layer, after which another layer is deposited directly on top, and so forth. In another 3-D printing method, glue is used to bind powders.
Aerospace companies are at the forefront of adopting the technology, because airplanes often need parts with complex geometries to meet tricky airflow and cooling requirements in jammed compartments. About 20,000 parts made by laser sintering are already flying in military and commercial aircraft made by Boeing, including 32 different components for its 787 Dreamliner planes, according to Terry Wohlers, a manufacturing consultant who specializes in additive processes. These aren't items that have to be mass-produced; Boeing might make a few hundred of them all year. They're also not critical to flight; among them are elaborately shaped air ducts needed for cooling, which previously had to be manufactured in multiple pieces. "Now we can optimize the design of these parts for weight, and we save material and labor," says Mike Vander Wel, director of Boeing's manufacturing technology strategy group. "In theory, this is the ultimate manufacturing method for us." Though the speed limitations of 3-D printing might keep it from ever producing the majority of Boeing's parts, Vander Wel says, the approach is likely to be used in a growing proportion of them.
Boeing's main rival, the European Aeronautic Defense and Space Company (EADS), is using the technology to make titanium parts in satellites and hopes to use it for parts it makes in higher volume for Airbus planes. "We don't yet know what the extent of our use of additive-layer manufacturing there will be yet, but we don't see any show stoppers," says Jon Meyer, who heads research on 3-D printing at EADS's Innovation Works division in England.

Smaller scale: Seen here is a microprinter that GE uses to test new ways of building things out of ceramic materials. Researchers are using the machine to print the transducers used as probes in ultrasound machines; they believe it might save time and money while improving design. Credit: Bob O’Connor

GE's jet engine division may be closer than anyone else to bringing 3-D-printed parts into large-scale commercial production. In addition to the fuel injector, GE is also laser-sintering titanium into complex shapes for four-foot-long strips bonded onto the leading edge of fan blades. These strips deflect debris and create more efficient airflow. Until now, each one has required tens of hours of forging and machining, during which 50 percent of the titanium was lost. By switching to 3-D printing, the company will save about $25,000 in labor and material in each engine, estimates Todd Rockstroh, the GE consulting engineer who heads the effort. The blade edge and the fuel injector will start appearing in engines as early as 2013, and they will be integrated into full-scale production runs in the thousands by about 2016.
Meanwhile, says Rockstroh, the company hopes to gain design flexibility by using 3-D printing for more parts. When it recently discovered that a stem in the fuel injector was subjected to excessive levels of heat stress, a redesigned version came out of the printer within a week. "Before, we would have had to redesign 20 different parts, with all the associated tooling," says Rockstroh. "It might not have even been possible." And using 3-D printing to corrugate the insides of some parts can reduce their weight by up to 70 percent, which can save an airline millions of gallons of fuel every year. That prospect has GE looking for ways to print everything from gearbox housings to control mechanisms. "We're going on a major weight-reduction scavenger hunt next year," Rockstroh says.
Automobiles could similarly benefit from lighter parts, and the University of Louisville's Gornet notes that printing processes could cut the weight of valves, pistons, and fuel injectors by at least half. Some manufacturers of ultraluxury and high-performance cars, including Bentley and BMW, are already using 3-D printing for parts with production runs in the hundreds.

Polished: A transducer made in GE’s microprinter (top) and the same transducer after being refined and finished in other machines (bottom). Credit: Bob O’Connor

CHALLENGES TO OVERCOME
If it weren't for the limitations of the technology, 3-D printing would already be much more broadly used. "Speeds are atrociously slow right now," says GE's Singh. Todd Grimm, who heads an additive-manufacturing consultancy in Edgewood, Kentucky, estimates that the time it takes to produce a part will have to improve as much as a hundredfold if 3-D printing is to compete directly with conventional manufacturing techniques in most applications. That won't happen in the next few years.
Another problem: for now, only a handful of plastic and metal compounds can be used in 3-D printing. In laser sintering, for example, the material must be able to form a powder that will melt neatly when it is hit with a laser, and then solidify quickly. The compounds that meet the necessary criteria can cost 50 to 100 times as much by weight as the raw materials used in conventional manufacturing processes, partly because they're in such low demand that they're available only from small specialty suppliers.
As demand increases with new applications, however, supplier competition should pull prices down dramatically. And the list of available materials is slowly expanding. GE is trying to use ceramics, which would open up new possibilities in engines and medical devices, among other areas.
Simple experience, too, will do much to improve the technology. So far, manufacturers don't have enough data to predict exactly how a part will turn out and how it will hold up, or how production variables—including temperature, choice of material, part shape, and cooling time—affect the results. That can be frustrating, says Singh: "3-D printing often ends up being a black art. A part is made out of thousands of layers, and each layer is a potential failure mode. We still don't understand why a part comes out slightly differently on one machine than it does on another, or even on the same machine on a different day." For example, the layering process tends to build up interlayer stresses in unpredictable ways, so that some parts end up distorted. Porosity can vary within parts as well, leading to concerns about fatigue or brittleness. That could be a big problem in aircraft engines or wing struts. "We know how to make the metals strong enough," says Boeing's Vander Wel. "But we worry about the unpredictability. Can we repeat a result to get 100 parts that are exactly the same? We're not sure yet."
Even with these challenges, time is on the side of 3-D printing, says Vander Wel, and not just because the processes are improving. Engineers are understandably reluctant to embrace a new technology for critical parts when their deadlines and reputations, not to mention the lives of people in airplanes, are at stake. "But younger designers are adapting more quickly," he says. "They're not so quick to say, 'It can't be built this way.'"
David H. Freedman, a science journalist based in Boston, wrote about optogenetics in the November/December 2010 issue of TR. His latest book is Wrong: Why Experts Keep Failing Us.