September 01, 2006

Follow up on image resolution improvement

Animation of cells working and real time tracking of metabolism

Roland Piquepailles technology trends points out an animation of living cells by XVIVO

The animation explores "the mechanisms that allow a white blood cell to sense its surroundings and respond to an external stimulus."

The technology used to study brain neurons in real time has been adapted for the real time study of other biological processes. This is going to rapidly boost our understanding of exactly how our cells and plant cells work. We can then modify those processes to boost food production or drugs and other products produced by biological means. Computer simulations will help to guide the understanding and the modifications of the processes. This will also accelerate transhumanist efforts to transcend current biology and improve human capabilities.

New technology addresses metabolism studyig problems by measuring sugar flux in real time in individual cells, with subcellular resolution.

Frommer and his colleagues have used similar imaging tags, called fluorescent resonance energy transfer (FRET) sensors, to track sugars and neurotransmitters in animal cells. Most recently, the group used FRET sensors to study glutamate, an important mammalian neurotransmitter. Frommer has tracked glucose in cultured mammalian cells, but until now, plant tissues had proven problematic because of interference from the plants' virus defense mechanisms, as well as high background fluorescence in some plants.

To surmount these issues, Frommer's team dramatically improved the sensors, while inserting them in mutant Arabidopsis plants with disabled defense genes. The fluorescent tags worked well where they had failed before.

FRET sensors are encoded by genes that, in theory, can be engineered into any cell line or organism. They are made of two fluorescent proteins that produce different colors of light--one cyan and one yellow--connected by a third protein that resembles a hinged clam shell. The two fluorescent proteins are derived from jellyfish, and the third from a bacterium; the shape of the clam shell protein determines which sugar or other molecule the sensor can detect. When a target molecule such as glucose or sucrose binds to the third protein, the hinge opens, changing the distance and orientation of the fluorescent proteins. This physical change affects the energy transfer between the cyan and yellow markers.

When the researchers hit the tags with light of a specific wavelength, the cyan tag starts to fluoresce. If the yellow tag is close enough, the cyan tag will transfer its energy to the yellow tag, causing it to resonate and fluoresce as well. This energy transfer affects how much cyan and yellow fluorescence can be seen, and by calculating this ratio, researchers can accurately track molecules such as glucose and sucrose in both time and space.

"The strength of this technology lies in its elegant simplicity; with the power of computational design, we can potentially design FRET tags to detect virtually any small molecule in living cells," Frommer said.

Nanoscale oscillaters work together for stronger signal

Groups of nanoscale magnetic oscillators are known to synchronize their individual 10-nanowatt signals to achieve a signal strength equal to the square of the number of devices. Now scientists at the National Institute of Standards and Technology (NIST), Seagate Research Center (Pittsburgh, Pa.) and Hitachi Global Storage Technologies (San Jose, Calif.) have discovered how—the oscillators accomplish this feat by communicating by means of “spin waves,” their magnetic emissions caused by oscillating patterns in the spin of electrons. Thanks to for the heads up on this artile.

Super inkjet printing

Kodak has a continuous inkjet printing process that works at offset speeds up to 24 miles per hour This technology could allow personalized magazines and direct mailings. Similarly newspapers could have tailored advertising and editorial content.

This should have implications for MEMS, nanotubes, nanoparticles and organ printing. Inkjet technology has been used to deposit carbon nanotubes on paper, to deposit biological cells for organ printing and other nanoscale manipulations. Alternative polymer based electronics that can use inkjet based manufacturing could become more competitive in cost and volumes with semiconductor fabs. Could other reel to reel processes also benefit? Such as the printing of solar cells ?

In 2003, Researchers from the University of Minnesota made tiny particles of gold, silver and carbon assemble into patterns on silicon wafers over areas as large as a square centimeter by using electrical charge patterns to attract and position the nanoparticles. They can eventually be used to form wires, circuits and even nanoscale devices like transistors. They printed 10- to 100-nanometer particles into patterns with features as fine as 200 nanometers using a process that started with the nanoparticles suspended in liquid. They were able to print features as fine as 100 nanometers by directing particles towards the charged surface using gas.

A discussion about printing electronics with inkjets

A conference on printing functional materials

Printing TV screens

Understanding Gene Therapy boosting T-cells to beat cancer

The human immune system has about 2 trillion lymphocytes. About one trillion are t-cells T lymphocytes develop from precursor stem cells in fetal liver and bone marrow and differentiate into mature cell types during residence in the thymus. Mature T lymphocytes (antigen responding, response control, and response mediating cells) are present in thymus, spleen, lymph nodes, throughout skin and other lymphatic organs, and in the bloodstream.

In the recent anti-cancer success, T-cells were provided with receptors that were 100 times more effective in helping them target the cancer tumor.

Here is another online tutorial about how t-cells work

This site has a tool that shows the size of different cells

A t-cell is about 20 microns in size

Basic view of cells and receptors.

More detailed representation of t cell receptor

August 31, 2006

Gene Therapy supercharges immune system success versus cancer

From Forbes: Working with 17 patients with advanced, metastatic melanoma skin cancers, Rosenberg's team first removed a small sample of normal T-cells from each patient. Next, the researchers genetically engineered the cells to carry a specific cell-surface receptor, one that would help them recognize melanoma cells.

These "re-armed" cells were then introduced back into the patient's bloodstream, where it was hoped they would gradually replace less-able lymphocytes and mount a fierce, sustained attack against the cancer.

That's exactly what happened for two of the 17 patients in the study, who quickly went into a sustained remission. "These two patients were treated over a year ago and are now disease-free," Rosenberg said

This is early work, but as the procedure is optimized holds the hope of higher rates of success.

August 30, 2006

Spintronics at room temperature

MIT research scientist Jagadeesh Moodera and his team have developed a material that works for spintronics at room temperature and is easy to create. The material is indium oxide, which is similar to the material used to conduct charge in an ATM's touch screen, with a small amount of chromium added to make it magnetic. Other materials that might work, Moodera says, include zinc oxide, widely used in sunscreen, and titanium oxide. The magnetic semiconductor would polarize the spin of the electrons, which then flow into the silicon chip where circuits would use them to perform calculations, while a detector, probably made of the same material as the spin injector, would read them as they flow out.

The material needs more development before it can be tested in an actual circuit. But Don Heiman, a professor of physics at Northeastern University, calls the creation of a magnetic semiconductor that works at room temperature "a pretty big breakthrough."

Remote Imaging 1000 times better possible and fast communication

In 3-5 years, remote imaging could have 1000 times better resolution. Currently it is 2cm resolution for US military satellites. They are suggesting that they can achieve 2 micron resolution which is about the wavelength of infrared light. However, even using that resolution for a 10 gigapixel image would only have 20cm (8 inches) by 20cm (8 inches) for the area being imaged. So it would be more useful to dial back and use less resolution most of the time to get a wider field of view.

The Super-LIDAR project indicates that they will put the devices into UAVs like predators. I was using satellite example because it happens to have some of the best surveillance that is available now. The LIDAR works better when it can fly around the thing it is watching to build up complete perspectives and model of the target where things like tree cover can be removed. It would use information that is blocked from one angle to "see past" it from another angle.

The difference in scale from 1000 times better resolution can be very well understood by some online tools:

Looking at the scale of things

This site has a tool that shows the different size scale of small objects

You can use them to see what zooming in from 1cm to 1 micron would look like. At 2 cm you are counting leaves. At 2 microns, you are counting leaf cells.

An online tutorial talks about how big cells are.

2 micron resolution means that you can see the individual skin cells and almost each e-coli that they have. You can analyze the 200 micron dust mites on the persons face.
===update done====

With $9.5 million in DARPA funding, S.J. Ben Yoo, an electrical and computer engineering professor at the University of California, Davis, plans to develop a technology that will push optical data transmission speeds up 10000 times. Working in cooperation with researchers at MIT and several commercial partners, Yoo's team plans to design, build, and test thumbnail-sized chips that can potentially encode data at rates of up to 100 THz, some 10,000 times faster than currently available devices. Extending upon the O-CDMA concept, it is possible to pursue achieve ultra-high capacity all-optical arbitrary waveform generation covering optical bandwidth of ~100 THz. MIT announcement for this project. Progress reports from the MIT lab

"We will be prototyping a compact optical waveform generator capable of communicating at unprecedented bandwidth," says Yoo, who is director of the UC Davis Center for Information Technology Research in the Interest of Society.

Over the next three years, Yoo's research team will be prototyping a new microsystem capable of manipulating and encoding mid-infrared light carrier comb frequencies. Besides ultra-high capacity communications, the improved technology could lead to the development of high-resolution light-based radars (ladars), enhanced medical imaging systems, and even electrical signal synthesizers capable of extremely rich electronic tones.

Yoo says the military envisions several future applications, including ultra-high resolution surveillance capabilities.

"They have a very keen interest in remote sensing and imaging," he says. The military would most like to nullify the enemy's ability to hide inside complex mountain terrains and cityscapes. A very compact ultra-high-resolution imaging system installed on an unmanned air vehicle (UAV), such as a Predator, could eliminate the need to send troops on reconnaissance missions into hostile areas.

"The military says they can image a tennis or soccer ball on a field from a satellite, but they want to do much better than that," says Yoo. "If they use our technology, they can make the resolution a thousand times better." That would allow the military to not only image a ball from space, but closely examine its surface texture—or the beads of sweat on an enemy combatant's forehead. Potential commercial applications include speedier optical data networks and higher-resolution, more realistic maps for personal navigation devices.

More reading:
Gigapixel cameras and current satellite surveillance. The article lists what can be seen with different resolution and the number of pixels required for facial recognition

High resolution cameras that are available now

Other advanced sensors for detecting nuclear, chemical and biological materials

More on LADAR (laser radar)

LIDAR at wikipedia

Speculation: Room temperature superconductors : milestone to complete master of energy and matter

By getting superconducting theory right (or making enough progress from theory and better experiment), we could guide material design of room temperature superconductors, higher current density material, better electronics, better power grid, possible magnetically ground launched space craft.

Room-temperature superconductors would be an important milestone on the path to complete mastery (within the actual limits of physics) of information, light, energy, magnetism, and matter. (ILEMM control)

What seems doable with far greater mastery of ILEMM:
Molecular nanotechnology

Large scale Quantum computers (millions of qubits)

Large scale space structures for solar energy collection and propulsion

Magnetic formation flying
Magnetically inflated cable
Light sails and beamed propulsion

Advanced magsails. Able to be ground launched if current densities could go up about 100-1000 times from the best available now.
More on magsails
PDF on magsails

Advanced metamaterials

Antimatter storage and harvesting work could eventually lead to the large scale creation of artificial mini-magnetospheres to allow antimatter to be created and collected.

Superconducting coil good enough for 36.5 MW ship engine

American Superconductor Corp. reported it has achieved levels of magnetic, electrical, thermal and mechanical performance required for commercial electromagnetic coils utilizing its proprietary second generation (2G) high temperature superconductor (HTS) wire.

Tests showed that 348 superconductors with today's performance levels can already be utilized to produce a 36.5-MW (almost 50,000 hp) high-temperature semiconductor ship propulsion motor able to operate at 38 degrees Kelvin—eight degrees higher than the operating temperature of the 36.5-MW ship propulsion motor that American Semiconductor is shipping to the U.S. Navy that utilizes the company's 1G HTS wire.

The advantages of a superconductor enhanced engine versus a conventional engine:
are 1/3 of the weight (69 tons instead of 200 tons)
1/2 the size
Up to 10% more fuel efficient at low speed

Specification sheet on the superconductor enhanced engines

The progress made over the last few decades with superconductors has been made without a solid and detailed theory of how superconductors exactly work. I think there will be substantial growth in our understanding of condensed matter physics over the next few years. This will come from the availability of new quantum computers for better accurate simulations of electrons and atoms and from new tools for more accurate measurements. The understanding of shortcomings in our current knowledge are shown by the development of entirely new areas of study such as in metamaterials.

Further Reading:
The factors that combine with a mechanism--known as the competing order--that lowers a superconductor's critical temperature in materials with more than three layers. That "competing order," in turn, is dependent on an uneven distribution of electrons, resulting in a charge imbalance between the material's multiple layers. Kee and her colleagues are the first group to put these three factors--the tunnelling, the competing order and the charge imbalance--together. If they can find a way to affect the charge imbalance, they could suppress the competing order and develop superconducting materials with higher and higher critical temperatures.

Understanding the mechanism for superconductivity

A paper (pdf) that proposes a design for a room temperature superconductor

Beginning of the end of silicon?

I think : The hybridization of nanotubes and semiconductors will accelerate and there will be some significant new niche products that take advantage of the higher current density of nanotubes. It will take longer and their will be more resistance to the shift from silicon than the researcher believes.

Researchers at Cambridge University have made a breakthrough in the manufacture of carbon nanotubes. They claim it heralds the beginning of the end for the silicon industry and the start of a new era of carbon nanotube-based miniaturised electronic applications.

The team from the university's engineering department has developed a way of growing single-wall carbon nanotubes at far lower temperatures than was previously believed possible.

Cantoro and his colleagues have experimented using CVD to closely control the development of the thin films of nanotubes and were able to reduce the temperature at which the nanotubes grow from 700C to 600C and finally to the breakthrough temperature of 350C. Cantoro describes 350C as being a 'technologically relevant number' as it means that the integration of nanotubes into semiconductors can now begin.

Cantoro admits there are a number of technical obstacles to overcome before carbon nanotubes can begin to usurp silicon for electronics supremacy. These include the ability to closely design the conductive properties of the nanotube and the difficulties inherent in growing a nanotube from one point to another.

Cantoro said the current trend of squeezing circuits and semiconductors into smaller and smaller spaces means there is a much greater current density on the circuits. As nanotubes are better able to withstand high current density than silicon, they could open up a whole new world of powerful miniaturised electronics, he says.

The team's next step is to work on integrating the carbon nanotubes fully with silicon semiconductors. Cantoro claimed that by early 2010 the first commercial circuits and semiconductor chips based entirely on carbon nanotubes will be in development.

Nanotube ink: Desktop printing of carbon nanotube patterns

Using an off-the-shelf inkjet printer, a team of scientists has developed a simple technique for printing patterns of carbon nanotubes on paper and plastic surfaces. The method, which is described in the August 2006 issue of the journal Small, could lead to a new process for manufacturing a wide range of nanotube-based devices, from flexible electronics and conducting fabrics to sensors for detecting chemical agents.

They simply fill a conventional ink cartridge with a solution of carbon nanotubes dissolved in water, and then the printer produces a pattern just as if it was printing with normal ink. Because nanotubes are good conductors, the resulting images also are able to conduct electricity.

"Printed carbon nanotube structures could be useful in many ways," Vajtai said. "Some potential applications based on their electrical conductivity include flexible electronics for displays, antennas, and batteries that can be integrated into paper or cloth." Printing electronics on cloth could allow people to actually "wear" the battery for their laptop computer or the entire electronic system for their cell phone, according to Vajtai.

The technique could be used to print optical tags on money and other paper items that need to be tracked, and it could even lead to an electronic newspaper where the text can be switched without changing the paper, he said. The researchers printed different samples, some of which show sensitivity to the vapors of several chemicals, which also could make them useful as gas sensors.

The approach is simple, versatile, and inexpensive, which makes it superior to other methods for producing conductive surfaces, according to Vajtai. "A great advantage of our process is that the printed patterns do not require curing, which is known to be a limiting factor for conventional conductive ink applications," he said. "And since our ink is a simple water-based dispersion of nanotubes, it is environmentally friendly and easy to handle and store."

other tech: future hard drives

Eventually, manufacturers will combine heat-assisted and patterned media to produce drives that will be capable of storing 50 to 100 terabits of data per square inch. That's 280 to 560 times more dense than the 178.8 gigabit-per-square-inch drive coming from Toshiba later this year.

Seagate Technologies, the world's largest drive maker, wants to first adopt a concept called "heat-assisted magnetic recording." This involves heating microscopic cells on the disk platters as part of the recording process. The heat-assisted camp wants to change the grains. Unlike cobalt-platinum grains, iron-platinum grains will not flip at room temperature. To record or erase data, a laser integrated into the drive would heat a particular bit. The data would get recorded or erased, and the bit would quickly cool. Material changes, however, are rarely easy; for example, the switch from aluminum to copper in semiconductors confounded semiconductor makers. For the heat-applied technology, engineers would have to perfect ways to pinpoint the heat from the laser.

Meanwhile, Hitachi Global Storage Technologies, No. 2 in the industry, favors going forward first with something called "patterned media." In this technique, the cells that store data--which now sit next to each other in a continuous film--would be isolated from each other like dots. the patterned media group wants to keep the current grains. It proposes, instead, reducing the number of grains in each bit from 100 to one, and then isolating the bits from each other to reduce cross-talk and the risk of data corruption. Initially, the grains in the first patterned media drives would be larger than the grains in today's drives, but the overall size of the bit would be smaller.

Ultimately, the decision could turn on which technology looks easier to bring to mass manufacturing. This year, around 450 million to 460 million drives will leave factories, according to data from Disk/Trend.

"We can see 50 to 100 terabits being possible," Kryder said. "We are three orders of magnitude from any truly fundamental limits."

other tech: Baldness protein code found

A research team in Manchester claims to have discovered a protein "code" that instructs cells to sprout hair. By sending the code to more cells than usual, the scientists at the University of Manchester say they were able to breed mice with more fur -- a feat that could potentially be replicated in humans.

Superior Hydrogen storing polymer found

A series of computer simulations has identified a polymer material with a very large capacity for storing hydrogen that could be exploited in fuel cells. Jisoon Ihm and colleagues at Seoul National University in South Korea have discovered that polyacetylene with titanium atoms attached to the polymer chain can hold 63 kilograms of hydrogen per cubic metre under practical conditions.

They found that up to five hydrogen molecules can be attached to each titanium atom in this particular form of polyacetylene, allowing the material to reversibly store 7.6 wt% of hydrogen, or 63 kilograms per cubic metre under practical working conditions. This value is higher than a target of 45 kilograms per cubic metre that the US Department of Energy said should be reached by 2010

August 29, 2006

Contribute to the direct to Diamondoid pathway

At the bottom of the long nanofactory collaboration page is a request for funds. The nanofactory collaboration is the leading theoretical and soon to be experimental effort for the direct to diamondoid molecular nanotechnology effort.

The economic value of the donated time and equipment currently being invested by all Collaboration participants on focused efforts is about $0.2M/yr, with almost no direct funding as yet. The ideal direct funding level to maximize results in the early years is $0.5-1M/yr, but even incremental support in the $30K-100K/yr range would produce measurable additional progress. The projection [below] assumes ideal funding levels are made available to a focused effort such as the Nanofactory Collaboration, and that our “Direct-to-DMS” approach is pursued rather than a more circuitous development approach that seeks to implement less efficacious nondiamondoid molecular manufacturing technologies before progressing to diamondoid.

Donations can be made through

How to donate to the IMM Freitas Research Fund:

* Phone 650-917-1120 with Visa/Mastercard info
* Fax 650 917 1123 with same
* Email with same (not secure)
* Mail info or check to Institute for Molecular Manufacturing, 123 Fremont Ave., Los Altos, CA 94022 USA

August 28, 2006

New anthrax inhibitor 50,000 times more potent

Anthrax toxin, secreted by the anthrax bacterium, is made of proteins and toxic enzymes that bind together to inflict damage on a host organism. Rather than targeting the anthrax bacterium or toxin - the approach taken by the majority of current therapies - the new inhibitor blocks the receptors where anthrax toxin attaches in the body. And because the nanoscale assembly of molecules is designed to bind to multiple sites on the host receptor, it is naturally more potent.

The new approach led to a 50,000-fold increase in potency in cell culture, and the inhibitor protected rats from anthrax toxin in the study. The general concept also could be applied to designing inhibitors for other pathogens, including SARS, influenza, and AIDS, the researchers note.

The inhibitor designed by the Rensselaer-Toronto team is "polyvalent," which means that it displays multiple copies of receptor-binding peptides, allowing it to bind at multiple sites and become more potent than an inhibitor that binds to a single site. For the current experiment, the researchers made four different polyvalent inhibitors and then tested each in cell culture. They found that the most potent of the four inhibitors enabled more than a 50,000-fold enhancement in activity compared to an inhibitor that was not based on polyvalency.

This potent inhibitor was then characterized more fully and tested in rats. Five out of six rats injected only with anthrax toxin died; all six rats injected with toxin and a non-polyvalent inhibitor died. But the new polyvalent inhibitor protected all six rats in the experiment, with no signs of adverse side effects.

Once fully developed, administering the new inhibitor to patients could help reduce the high mortality rates associated with inhalational anthrax, according to the researchers. Antibiotics slow the progression of infection by targeting the anthrax bacterium, but they do not counter the advanced destructive effects of anthrax toxin in the body. Inhalation anthrax still has a fatality rate of 75 percent even after antibiotics are given, according to the Centers for Disease Control and Prevention. "Combining the inhibitor with antibiotic therapy may increase the likelihood of survival for an infected person," Kane said.

Breakthrough Magnetometer

From www.nanotech-now.comMPhase has about 25 employees, most of which have been assigned to the task of helping to make its magnetometer 50 times smaller and 1,000 times more sensitive than the most powerful devices on the market today. While current devices are expensive, bulky and require supercooling to -455 F, the model in progress at mPhase works at room temperature, fits on the dateline of a penny and can pick up on a metal object from more than 30 feet away.

The company, founded in 1996, has two other technologies in development. It is working on transmitting television over high-speed Internet lines and nanotechnology-based batteries.

Other related:
Bose-Einstein condensates magnetometer Physicists at the University of Heidelberg have used a one-dimensional BEC as a sensitive probe of the magnetic fields emanating from a nearby sample. The field sensitivity achieved thereby is at the level of magnetic fields of nanotesla strength (equivalent to an energy scale of about 10-14 electronvolt) with a spatial resolution of only 3 microns. Some methods (such as scanning hall probe microscopes) can attain finer spatial resolution and some methods (such as superconducting quantum interference devices -- SQUIDs) can attain higher magnetic sensitivity, but for its range, the Heidelberg device has a region of the sensitivity-vs-resolution space all to itself.

In both its battery and magnetometer efforts, mPhase has joined forces with Bell Labs. The two have inked deals to co-develop, market and sell the nanobatteries and magnetometers.

Mitochondrial DNA sequencing tool updated

they have developed a second generation "lab on a silicon chip" called the MitoChip v2.0 that for the first time rapidly and reliably sequences all mitochondrial DNA. Mitochondria, the energy-producing organelles that power our cells, are unique because they are equipped with their own genetic instructions distinct from the DNA stored in the cell nucleus. The Mitochip v2.0 full-sequence chip will be a key tool in accelerating research on mitochondrial DNA, a growing area of scientific interest. This interest stems from data that suggests natural sequence variations and/or mutations in each person's mitochondrial DNA could be biologically informative in fields as diverse as cancer diagnostics, gerontology, and criminal forensics.

Data suggests that natural sequence variations and/or mutations in each person's mitochondrial DNA could be biologically informative in fields as diverse as cancer diagnostics, gerontology, and criminal forensics. Hundreds to thousands of mitochondria exist in each human cell, occupying up to a quarter of their cytoplasm. Sometimes informally described as "cellular power plants," mitochondria convert organic materials into ATP, the cell's energy currency and without which life would cease.

Dr. Maitra said that despite the original Mitochip's 96 percent success rate assigning base calls, there was room for improvement. Led by Drs. Shaoyu Zhou and Keyaunoosh Kassauei, the Hopkins group cobbled together the MitoChip v2.0. reported in this month's Journal of Molecular Diagnostics. It yielded essentially the same base-call success rate as its predecessor, showed near perfect reproducibility in replicate experiments, and detected more variations than the first-generation chip.

As a proof of principle, the Mitochip v2.0 also detected 31 variations in the non-coding D-loop of 14 head and neck tumor samples. Included in this tally were several mutations that possibly are informative of the disease.

"The real interesting thing is nobody has been able to study these D-loop alterations very well," said Califano "They clearly occur in tumor cells, and there is some type of selection process for them. But their functional significance has been hard to know. Now, you can sequence the D loop so readily and begin to look harder for associations in certain cancers."

Using the chip they have arrayed 500 of the most common haplotypes - or grouped patterns of known DNA variations - banked in the mitochondrial public database.

Carbon nanotube strings may identify single molecules

Nanoscale "guitar strings" that vibrate at more than one billion times per second could detect and identify individual molecules.

A group led by Alex Zettl, a condensed matter physicist at the University of California, Berkeley, US, used electron-beam lithography and reactive ion etching to create a trench 300 nanometres across with electrodes on either side and a chargeable plate at the bottom.

The researchers then coaxed carbon nanotubes to grow across the gap. Driven by high-frequency signals, the tiny bridges resonate at 1.3 billion cycles per second, or 1.3 gigahertz.

“Other groups have made resonators that were very small, and have gotten into the one gigahertz regime, but only at very low temperatures and pressures,” says Zettl. “So getting these very high frequencies under room temperature and atmospheric pressure is a real breakthrough.”

the team measured the nanotubes' oscillations in a novel way. Instead of mixing the signal from the nanotubes' vibrations into a test current alternating at a similar frequency, they used a signal at twice the resonant frequency. The result was a much sharper measurement.

it is that high sensitivity that lets them detect the how a test mass placed on the string causes it to vibrate more slowly. The device can detect masses of just 10-18 grams. “This is where you can measure molecules,” says Zettl. “Biological molecules, threat molecules – the sort of things airport screeners are interested in – have masses in this range. We’d like to push it to where you can measure individual atoms, but in everyday life the most interesting things are molecules.”

Fixing Global Warming

Immediate personal action that can be taken. Analyze your own homes energy consumption and try to optimize energy usage in the most cost effective way.

The US dept of energy has advice and special online calculators to help you make your plans.

Some of the best first steps usually are
* Caulk and weatherstrip windows and exterior doors.
* Carefully select, install, and use window treatments or coverings.
* Energy efficient light bulbs

Other near-term technology:
Diesel engines that meet the USs strict pollution standard are coming and they provide 45% better fuel efficiency and more mid-range torque.

We need to have sustained funding of energy efficient technology research and deployment.

sulfur geoengineering
"" target=blank>A proposal from a nobel prize winning scientist is to buy time by temporarily lowering the temperature in the global climate. Paul Crutzen of Germany's Max Planck Institute for Chemistry suggests injecting particles of sulfur into the stratosphere—the upper layer of the atmosphere—to cool the planet and buy time for humans to reduce greenhouse gas emissions.

The sulfur particles would be dropped from high-altitude balloons or fired into the atmosphere with heavy artillery shells, he says. Once airborne the particles would act like tiny mirrors, bouncing the sun's light and heat back into space. Crutzen's plan would imitate the cooling effects of volcanic eruptions, which send large sulfur-rich clouds into the atmosphere. When Mount Pinatubo in the Philippines erupted in 1991, he points out, the huge plume of sulfur cooled the Earth by 0.9 degree Fahrenheit (0.5 degree Celsius) the following year. A relatively small amount of sulfate could produce a level of cooling similar to that caused by the Pinatubo eruption, according to Crutzen's calculations. Crutzen calculates that launching enough sulfate to have an effect for two years would cost between 25 billion and 50 billion U.S. dollars, about $25 to $50 per head in the developed world. Possible downsides are more acid rain and ozone issues. So it is not a free lunch, but this and other climate engineering (solar shield at Lagrange point) seems like necessary short term steps.

Two years ago John Latham, an atmospheric scientist from the U.S. National Center for Atmospheric Research in Boulder, Colorado, and his colleagues put forward a plan to whisk up seawater to encourage cloud formation in the lower atmosphere, thereby reflecting radiation back into space.

"All of us recognize that geo-engineering seems increasingly likely to be the only route to staving off a cataclysm in the short term before new, clean energy sources are developed sufficiently," Latham said.

Fuel cell powered UAV aircraft created

Georgia Institute of Technology researchers have
conducted successful test flights of a hydrogen-powered unmanned
aircraft believed to be the largest to fly on a proton exchange
membrane (PEM) fuel cell using compressed hydrogen.
Fuel cells
have more fuel efficiency potential than regular engines and less

Fuel cells, which create an electrical current when they convert
hydrogen and oxygen into water, are attractive as energy sources
because of their high energy density. Higher energy density translates
into longer endurance.

Though fuel cells don't produce enough power for the propulsion
systems of commercial passenger aircraft, they could power smaller,
slower vehicles like unmanned aerial vehicles (UAVs) and provide a low
cost alternative to satellites. Such UAVs could also track hurricanes,
patrol borders and conduct general reconnaissance.

Fuel cell powered UAVs have several advantages over conventional UAV.
Fuel cells emit no pollution and unlike conventional UAVs, don't
require separate generators to produce electricity for operating
electronic components. "Another plus, because fuel cells operate at
near ambient temperatures, UAVs emit less of a heat signature and
would be stealthier than conventionally powered UAVs," Tom Bradley

During the next few months, the team will continue to test and refine
the aircraft, making it more reliable and robust. Ultimately, they
plan to design and build an UAV capable of a trans-Atlantic flight –
something that Parekh believes will be possible within the next five

Researchers discover how a signal tells cells whether to grow or die

Controlling the life and death of cells is important for fighting cancer and possible life extension.

Researchers at the European Molecular Biology Laboratory [EMBL] in Heidelberg have now discovered how one of these signaling pathways controls the life and death of cells in the fruit fly. The study will be published in this week's issue of the journal Cell.

The breakthrough came as Barry Thompson from Stephen Cohen's group at EMBL looked at a recently discovered signaling pathway called Hippo.

"Hippo acts as a switch between cell division and death," says Barry Thompson, "if the pathway is too active, tissues overgrow because too many cells divide and too few die. But until now, we hadn't found a connection between the signals and the cellular machinery that drives growth."

Using sophisticated genetic techniques, Thompson and Cohen established that a small molecule, a microRNA called bantam, makes this link. Without bantam, tissues grow too slowly and remain smaller than normal. The amount of bantam produced by the cell directly depends on the amount of traffic on the Hippo signaling pathway, and higher levels of bantam prompt more cell division.

The next step will be to identify the RNAs that bantam docks onto to control. This will provide a more complete view of the Hippo pathway and may provide insights into the central role it plays in tissue growth and cancers in humans and other organisms.

August 27, 2006

Materials with nearly zero structural imperfections possible with controlled grain size

A scientist at North Carolina State University has discovered that the tiny grains comprising many bulk materials can potentially contain nearly zero structural imperfections when the grains are smaller than a certain critical size, typically a few to several nanometers.

Materials created with grains of the right (optimal) size could be structurally flawless. Not only would these materials possess exceptional strength and durablity, but their optical, electrical, and magnetic properties could be vastly improved as well. The number of potential applications, such as smart sensors and ultra-efficient “solid-state” lighting, as well as entire industries impacted, such as automobiles and defense, is staggering.

Narayan discusses the many types of defects that can be present in a material and shows, via theoretical arguments and a couple of specific examples, how controlling grain size may be able to prevent them.

One type of defect is a dislocation, an irregularity in the repetitive pattern of a crystalline material that compromises strength. It is nearly impossible to eliminate dislocations, Narayan says, but reducing the grain size can theoretically restrict the movement of a dislocation so that it can't propagate through the rest of the material. For copper, he calculates that this will occur at the critical grain size of about 7.5 nanometers (nm).

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