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Sunday, March 31, 2013

Multi-Toxin Crops A Bad Idea Say Scientists


Crucial assumptions underlying multi-toxin crops don't always apply, a University of Arizona study shows. The results help explain why one major pest is evolving resistance faster than predicted and offer ideas for more sustainable pest control

A major agricultural pest, the moth Helicoverpa zea and its caterpillar go by many common names, depending on the crop they feed on: shown here is a "corn earworm."
Credit: Jose Roberto Peruca

A strategy widely used to prevent pests from quickly adapting to crop-protecting toxins may fail in some cases unless better preventive actions are taken, suggests new research by University of Arizona entomologists published in the Proceedings of the National Academy of Sciences.

Corn and cotton have been genetically modified to produce pest-killing proteins from the bacterium Bacillus thuringiensis, or Bt for short. Compared with typical insecticide sprays, theBt toxins produced by genetically engineered crops are much safer for people and the environment, explained Yves Carrière, a professor of entomology in the UA College of Agriculture and Life Sciences who led the study.

Although Bt crops have helped to reduce insecticide sprays, boost crop yields and increase farmer profits, their benefits will be short-lived if pests adapt rapidly, said Bruce Tabashnik, a co-author of the study and head of the UA department of entomology. "Our goal is to understand how insects evolve resistance so we can develop and implement more sustainable, environmentally friendly pest management," he said.

Bt crops were first grown widely in 1996, and several pests have already become resistant to plants that produce a single Bt toxin. To thwart further evolution of pest resistance to Bt crops, farmers have recently shifted to the "pyramid" strategy: each plant produces two or more toxins that kill the same pest. As reported in the study, the pyramid strategy has been adopted extensively, with two-toxin Bt cotton completely replacing one-toxin Bt cotton since 2011 in the U.S.

Most scientists agree that two-toxin plants will be more durable than one-toxin plants. The extent of the advantage of the pyramid strategy, however, rests on assumptions that are not always met, the study reports. Using lab experiments, computer simulations and analysis of published experimental data, the new results help explain why one major pest has started to become resistant faster than anticipated.

"The pyramid strategy has been touted mostly on the basis of simulation models," said Carrière. "We tested the underlying assumptions of the models in lab experiments with a major pest of corn and cotton. The results provide empirical data that can help to improve the models and make the crops more durable."

One critical assumption of the pyramid strategy is that the crops provide redundant killing, Carrière explained. "Redundant killing can be achieved by plants producing two toxins that act in different ways to kill the same pest," he said, "so, if an individual pest has resistance to one toxin, the other toxin will kill it."

The same pest is called cotton bollworm when plaguing cotton plants.

Credit: Thierry Brevault/CIRAD

In the real world, things are a bit more complicated, Carrière's team found out. Thierry Brévault, a visiting scientist from France, led the lab experiments at the UA. His home institution, the Center for Agricultural Research for Development, or CIRAD, is keenly interested in factors that could affect pest resistance to Bt crops in Africa.

"We obviously can't release resistant insects into the field, so we breed them in the lab and bring in the crop plants to do feeding experiments," Carrière said. For their experiments, the group collected cotton bollworm – also known as corn earworm or Helicoverpa zea –, a species of moth that is a major agricultural pest, and selected it for resistance against one of the Bt toxins, Cry1Ac.

As expected, the resistant caterpillars survived after munching on cotton plants producing only that toxin. The surprise came when Carrière's team put them on pyramided Bt cotton containing Cry2Ab in addition to Cry1Ac.

If the assumption of redundant killing is correct, caterpillars resistant to the first toxin should survive on one-toxin plants, but not on two-toxin plants, because the second toxin should kill them, Carrière explained.

"But on the two-toxin plants, the caterpillars selected for resistance to one toxin survived significantly better than caterpillars from a susceptible strain."

These findings show that the crucial assumption of redundant killing does not apply in this case and may also explain the reports indicating some field populations of cotton bollworm rapidly evolved resistance to both toxins.

Moreover, the team's analysis of published data from eight species of pests reveals that some degree of cross-resistance between Cry1 and Cry2 toxins occurred in 19 of 21 experiments. Contradicting the concept of redundant killing, cross-resistance means that selection with one toxin increases resistance to the other toxin.

According to the study's authors, even low levels of cross-resistance can reduce redundant killing and undermine the pyramid strategy. Carrière explained that this is especially problematic with cotton bollworm and some other pests that are not highly susceptible to Bttoxins to begin with.

The team found violations of other assumptions required for optimal success of the pyramid strategy. In particular, inheritance of resistance to plants producing only Bt toxin Cry1Ac was not recessive, which is expected to reduce the ability of refuges to delay resistance.

Insects can carry two forms of the same gene for resistance to Bt – one confers susceptibility and the other resistance. When resistance to a toxin is recessive, one resistance allele is not sufficient to increase survival. In other words, offspring that inherit one allele of each type will not be resistant, while offspring that inherit two resistance alleles will be resistant.

Refuges consist of standard plants that do not make Bt toxins and thus allow survival of susceptible pests. Under ideal conditions, inheritance of resistance is recessive and the susceptible pests emerging from refuges greatly outnumber the resistant pests. If so, the matings between two resistant pests needed to produce resistant offspring are unlikely. But if inheritance of resistance is dominant instead of recessive, as seen with cotton bollworm, matings between a resistant moth and a susceptible moth can produce resistant offspring, which hastens resistance.

According to Tabashnik, overly optimistic assumptions have led the EPA to greatly reduce requirements for planting refuges to slow evolution of pest resistance to two-toxin Btcrops.

The new results should come as a wakeup call to consider larger refuges to push resistance further into the future, Carrière pointed out. "Our simulations tell us that with 10 percent of acreage set aside for refuges, resistance evolves quite fast, but if you put 30 or 40 percent aside, you can substantially delay it."

"Our main message is to be more cautious, especially with a pest like the cotton bollworm," Carrière said. "We need more empirical data to refine our simulation models, optimize our strategies and really know how much refuge area is required. Meanwhile, let's not assume that the pyramid strategy is a silver bullet."

Contacts and sources:
Daniel Stolte
University of Arizona

Earth Changes: "North Australia Will Be At Equator" And Africa Will Be Pulled Apart Says German Scientists

Mineralogists of the Universities Jena and Bayreuth explain in the science magazine Nature Geoscience why plate tectonics stagnates in some places

The Earth is dynamic. What we perceive as solid ground beneath our feet, is in reality constantly changing. In the space of a year Africa and America are drifting apart at the back of the Middle Atlantic for some centimeters while the floor of the Pacific Ocean is subducted underneath the South American Continent.

 "In 100 million years' time Africa will be pulled apart and North Australia will be at the equator," says Prof. Dr. Falko Langenhorst from the Friedrich Schiller University Jena (Germany). Plate tectonics is leading to a permanent renewal of the ocean floors, the mineralogist explains. The gaps between the drifting slabs are being filled up by rising melt, solidifying to new oceanic crust. In other regions the slabs dive into the deep interior of the Earth and mix with the surrounding Earth's mantle.

File:Earth poster.svg
Credit: Wikipedia

The Earth is the only planet in our solar system, conducting such a 'facelift' on a regular basis. But the continuous up and down on the Earth`s crust doesn't run smoothly everywhere. "Seismic measurements show that in some mantle regions, where one slab is subducted underneath another one, the movement stagnates, as soon as the rocks have reached a certain depth," says Prof. Langenhorst. The causes of the 'congestion' of the subducted plate are still unknown. In the current issue of the science magazine 'Nature Geoscience' Prof. Langenhorst and earth scientists of Bayreuth University now explain the phenomenon for the first time (DOI: 10.1038/NGEO1772).

According to this, the rocks of the submerging ocean plate pond at a depth of 440 to 650 kilometers – in the transition zone between the upper and the lower Earth mantle. "The reason for that can be found in the slow diffusion and transformation of mineral components," mineralogist Langenhorst explains. 

On the basis of high pressure experiments the scientists were able to clarify things: under the given pressure and temperature in this depth, the exchange of elements between the main minerals of the subducted ocean plate – pyroxene and garnet – is slowed down to an extreme extent. "The diffusion of a pyroxene-component in garnet is so slow, that the submerging rocks don't become denser and heavier, and therefore stagnate," the Jena scientist says.

Interestingly there is congestion in the earth mantle exactly where the ocean floor submerges particularly fast into the interior of the Earth. "In the Tonga rift off Japan for example, the speed of subduction is very high," Prof. Langenhorst states. Thereby the submerging rocks of the oceanic plate stay relatively cold up to great depth, which makes the exchange of elements between the mineral components exceptionally difficult.

 "It takes about 100 Million years for pyroxene crystals which are only 1 mm in size to diffuse into the garnet. For this amount of time the submerging plate stagnates," Langenhorst describes the rock congestion. It can probably only diffuse at the boundary of the lower Earth mantle. Because then pyroxene changes into the mineral akimotoite due to the higher pressure in the depth of 650 kilometers. "This could lead to an immediate rise in the rock density and would enable the submerging into greater depths."


Contacts and sources:
Ute Schoenfelder 
Prof. Dr. Falko Langenhorst
Institute for Geosciences
Friedrich-Schiller-Universitaet Jena

Citation:  Van Mierlo VL et al. Stagnation of subducting slabs in the transition zone due to slow diffusion in the majoritic garnet. Nature  

Arctic Is Going Green With Boom In Trees And Shrubs As World Warms

New research predicts that rising temperatures will lead to a massive "greening," or increase in plant cover, in the Arctic. In a paper published on March 31 in Nature Climate Change, scientists reveal new models projecting that wooded areas in the Arctic could increase by as much as 50 percent over the next few decades. The researchers also show that this dramatic greening will accelerate climate warming at a rate greater than previously expected.

This set of images shows the observed distribution of Arctic vegetation (left) in relation to the predicted distribution of vegetation under a climate warming scenario for the 2050s (right). Data used to generate the observed image are from the Circumpolar Arctic Vegetation Map (2003).

Credit: AMNH/R. Pearson

"Such widespread redistribution of Arctic vegetation would have impacts that reverberate through the global ecosystem," said Richard Pearson, lead author on the paper and a research scientist at the American Museum of Natural History's Center for Biodiversity and Conservation.

Plant growth in Arctic ecosystems has increased over the past few decades, a trend that coincides with increases in temperatures, which are rising at about twice the global rate. The research team—which includes scientists from the Museum, AT&T Labs-Research, Woods Hole Research Center, Colgate University, Cornell University, and the University of York—used climate scenarios for the 2050s to explore how this trend is likely to continue in the future. The scientists developed models that statistically predict the types of plants that could grow under certain temperatures and precipitation. Although it comes with some uncertainty, this type of modeling is a robust way to study the Arctic because the harsh climate limits the range of plants that can grow, making this system simpler to model compared to other regions such as the tropics.

The models reveal the potential for massive redistribution of vegetation across the Arctic under future climate, with about half of all vegetation switching to a different class and a massive increase in tree cover. What might this look like? In Siberia, for instance, trees could grow hundreds of miles north of the present tree line.

"These impacts would extend far beyond the Arctic region," Pearson said. "For example, some species of birds seasonally migrate from lower latitudes and rely on finding particular polar habitats, such as open space for ground-nesting."

In addition, the researchers investigated the multiple climate change feedbacks that greening would produce. They found that a phenomenon called the albedo effect, based on the reflectivity of the Earth's surface, would have the greatest impact on the Arctic's climate. When the sun hits snow, most of the radiation is reflected back to space. But when it hits an area that's "dark," or covered in trees or shrubs, more sunlight is absorbed in the area and temperature increases. This has a positive feedback to climate warming: the more vegetation there is, the more warming will occur.

"By incorporating observed relationships between plants and albedo, we show that vegetation distribution shifts will result in an overall positive feedback to climate that is likely to cause greater warming than has previously been predicted," said co-author Scott Goetz, of the Woods Hole Research Center.

This work was funded by the National Science Foundation, grants IPY 0732948, IPY 0732954, and Expeditions 0832782. Other authors involved in this study include Steven Phillips (AT&T Labs-Research), Michael Loranty (Woods Hole Research Center and Colgate University), Pieter Beck (Woods Hole Research Center), Theodoros Damoulas (Cornell University), and Sarah Knight (American Museum of Natural History and University of York).

 
Contacts and sources: 

Kendra Snyder
American Museum of Natural History

World Record Silicon-Based Millimeter-Wave Power Amplifiers

A first for amplifiers on silicon; may unlock applications in low-cost satellite communications

Two teams of DARPA performers have achieved world record power output levels using silicon-based technologies for millimeter-wave power amplifiers. RF power amplifiers are used in communications and sensor systems to boost power levels for reliable transmission of signals over the distance required by the given application. These breakthroughs were achieved under the Efficient Linearized All-Silicon Transmitter ICs (ELASTx) program. Further integration efforts may unlock applications in low-cost satellite communications and millimeter-wave sensing.



The first team, composed of performers at the University of Southern California and Columbia University, achieved output power levels of nearly 0.5 W at 45 gigahertz with a 45 nanometer silicon complementary metal oxide semiconductor (CMOS) chip. This world record result for CMOS-based power amplifiers doubles output power compared to the next best reported CMOS millimeter-wave power amplifier. The chip design used multiple stacked 45 nanometer silicon-on-insulator CMOS devices for increased effective output voltage swing and efficient 8-way on-chip power-combining. Results will be reported at the 2013 Institute of Electrical and Electronics Engineers Radio Frequency Integrated Circuits Symposium.



The second team, made up of MIT and Carnegie Mellon University researchers, demonstrated a 0.13 micrometer silicon-germanium (SiGe) BiCMOS power amplifier employing multistage power amplifier cells and efficient 16-way on-chip power-combining. This amplifier has achieved power output of 0.7 W at 42 gigahertz, a 3.5 times increase in output power compared to the next best reported silicon-based millimeter-wave power amplifier; this result was reported at the 2013 International Solid-State Circuits Conference (ISSCC).

“Millimeter-wave power amplifiers have been demonstrated at this power level before, but this is a record with silicon-based technologies,” said Sanjay Raman, DARPA program manager. “Producing this level of output with silicon may allow integration on a chip with complex analog and digital signal processing. In the 42-25 GHz range, this would enable high bandwidth/data-rate transmitters needed for satellite communications at potentially very low cost and size, weight and power.”

Silicon-based circuit techniques developed under the ELASTx program may eventually be applied to even higher performance compound semiconductor devices, such as gallium nitride high electron mobility transistors. These architectural breakthroughs will be investigated for such integration opportunities under a different DARPA effort, the Diverse Accessible Heterogeneous Integration (DAHI) program.

Source: DARPA 

Saturday, March 30, 2013

Hubble Observes The Hidden Depths Of Messier 77

The NASA/ESA Hubble Space Telescope has captured this vivid image of spiral galaxy Messier 77, one of the most famous and well-studied galaxies in the sky. The patches of red across this image highlight pockets of star formation along the pinwheeling arms, with dark dust lanes stretching across the galaxy’s energetic centre.




Messier 77 is a galaxy in the constellation of Cetus, some 45 million light-years away from us. Also known as NGC 1068, it is one of the most famous and well-studied galaxies. It is a real star among galaxies, with more papers written about it than many other galaxies put together!

Despite its current fame and striking swirling appearance, the galaxy has been a victim of mistaken identity a couple of times; when it was initially discovered in 1780, the distinction between gas clouds and galaxies was not known, causing finder Pierre Méchain to miss its true nature and label it as a nebula. It was misclassified again when it was subsequently listed in the Messier Catalogue as a star cluster.

This video pans across the sky near to spiral galaxy Messier 77 in the constellation of Cetus, ending on a view of the famous object itself. M 77 is a highly-studied galaxy, with an active black hole at its centre and regions of bright star formation dotted along its loosely-wound arms.

Credit: NASA, ESA, Digitized Sky Survey 2. Acknowledgement: A. van der Hoeven

Now, however, it is firmly categorised as a barred spiral galaxy, with loosely wound arms and a relatively small central bulge. It is the closest and brightest example of a particular class of galaxies known as Seyfert galaxies — galaxies that are full of hot, highly ionised gas that glows brightly, emitting intense radiation.

Strong radiation like this is known to come from the heart of Messier 77 — caused by a very active black hole that is around 15 million times the mass of our Sun. Material is dragged towards this black hole and circles around it, heating up and glowing strongly. This region of a galaxy alone, although comparatively small, can be tens of thousands of times brighter than a typical galaxy.

This video zooms in on spiral galaxy Messier 77. The sequence begins with a view of the night sky near the constellation of Cetus. It then zooms through observations from the Digitized Sky Survey 2, and ends with a view of the galaxy obtained by Hubble.
Credit:  NASA, ESA, Digitized Sky Survey 2. Acknowledgement: A. van der Hoeven

Although no competition for the intense centre, Messier 77’s spiral arms are also very bright regions. Dotted along each arm are knotty red clumps — a signal that new stars are forming. These baby stars shine strongly, ionising nearby gas which then glows a deep red colour as seen in the image above. The dust lanes stretching across this image appear as a rusty, brown-red colour due to a phenomenon known as reddening; the dust absorbs more blue light than red light, enhancing its apparent redness.

This image from the Digitized Sky Survey shows spiral galaxy Messier 77 and its surroundings.
Wide-field image of Messier 77 (ground-based image)
Credit: NASA, ESA, Digitized Sky Survey 2

A version of this image won second place in the Hubble’s Hidden Treasures Image Processing Competition, entered by contestant Andre van der Hoeven [1].


Contacts and sources:
Nicky Guttridge
Hubble/ESA

Super Hearing With 3-D Audio Technology: Pilots To Hear Direction Of Enemy And Radio Communications

Raytheon's 3-D Audio technology alerts aviators to the exact direction and type of threat coming toward them. The same system also makes radio channels sound like they're coming from different directions, helping pilots better monitor communications.


Credit: Raytheon

It’s the bottom of the ninth, the batter hits a foul ball into the crowd and someone yells, “Look out!” The first reaction of a spectator in danger is to look toward the person yelling, not the ball.

But what if the ball itself made noise? A new “3-D Audio” system for military pilots does exactly that, alerting aviators to the exact direction and type of threat coming toward them. The same system also makes radio channels sound like they’re coming from different directions, helping pilots better monitor radio traffic.

The technology from Raytheon solves a serious problem for warfighters, said J.D. Hill, a program engineer for the Waltham, Mass.-based defense company.

Current warning technology requires pilots to look at and interpret a visual display before deciding what to do. Raytheon’s 3-D Audio, meanwhile, generates "geospatial" sounds to indicate threats.

“You always hear them from where they actually are,” Hill said. “You don’t have to interpret anything. It’s all just about reaction and what you hear.”


Credit: Raytheon

Raytheon’s system even senses when pilots turn their heads and moves the computer-generated sound accordingly, Hill said.

3-D Audio also allows pilots to better monitor multiple radio channels, said Todd Lovell, a Raytheon engineer and former V-22 Osprey pilot.

“Pilots for years have been listening to three or four radios, and when two people would talk at the same time, it would just come across garbled,” Lovell said. “With the 3-D Audio, we can put those radios in different spatial locations relative to your head.”

Pilots could set up their radios so a co-pilot’s voice comes from the side, a passenger’s voice comes from behind, and the voice of an air traffic controller comes from ahead of the aircraft.

“Just like we can understand one conversation in a crowded room, you can concentrate on that one conversation and listen to that radio,” Lovell said.


Credit: Raytheon

The 3D Audio technology is part of a suite of situational awareness designed to make pilots all-knowing and all-seeing.

Raytheon’s Advanced Distributed Aperture System stitches together views collected by sensors arranged around the outside an aircraft. The technology gives pilots a “glass ball” view through dust, snow – and even the floor of their cockpits.

The company’s Center Display Unit is a drop-in replacement that brings state-of-the-art sensor displays to older aircraft including the popular F-16.

The Aviation Warrior wearable computer, meanwhile, allows pilots to bring all of these technologies with them even if they leave the cockpit.

The products work together to use a pilot’s senses to the fullest, Hill said.

“When you can add that technology to the cockpit, it just enhances everything that a pilot can do,” Hill said.

Contacts and sources:
Ratheon

Panorama From Curiosity Rover By Photographer Andrew Bodrov

With its rover named Curiosity, Mars Science Laboratory mission is part of NASA's Mars Exploration Program, a long-term effort of robotic exploration of the red planet. Curiosity was designed to assess whether Mars ever had an environment able to support small life forms called microbes. In other words, its mission is to determine the planet's "habitability."

Mars Gigapixel Panorama - Curiosity rover: Martian solar days 136-149 in The World
Image: Andrew Bodrov 

By , a member of the International Virtual Reality Photography Association (IVRPA), has been professionally engaged in panoramic photography for over 12 years. He has shot panoramas for the 3D Tallinn Project, Tallinn Song Festival, Cathedral of Christ the Savior in Moscow, Baikonur Cosmodrome as well as hundreds of other panoramas from around the world.

NASA's Mars rover Curiosity has resumed science investigations after recovery from a computer glitch that prompted the engineers to switch the rover to a redundant main computer on Feb. 28.

The rover has been monitoring the weather since March 21 and delivered a new portion of powdered-rock sample for laboratory analysis on March 23, among other activities.

"We are back to full science operations," said Curiosity Deputy Project Manager Jim Erickson of NASA's Jet Propulsion Laboratory, Pasadena, Calif. 

This view of Curiosity's left-front and left-center wheels and of marks made by wheels on the ground in the "Yellowknife Bay" area comes from one of six cameras used on Mars for the first time more than six months after the rover landed. The left Navigation Camera (Navcam) linked to Curiosity's B-side computer took this image during the 223rd Martian day, or sol, of Curiosity's work on Mars (March 22, 2013). The wheels are 20 inches (50 centimeters) in diameter. 
View From Camera Not Used During Curiosity's First Six Months on Mars
Image credit: NASA/JPL-Caltech

The powder delivered on Saturday came from the rover's first full drilling into a rock to collect a sample. The new portion went into the Sample Analysis at Mars (SAM) instrument inside the rover, which began analyzing this material and had previously analyzed other portions from the same drilling. SAM can analyze samples in several different ways, so multiple portions from the same drilling are useful.

The Rover Environmental Monitoring Station (REMS) is recording weather variables. The Radiation Assessment Detector (RAD) is checking the natural radiation environment at the rover's location inside Gale Crater.

Like many spacecraft, Curiosity carries a pair of main computers, redundant to each other, to have a backup available if one fails. Each of the computers, A-side and B-side, also has other redundant subsystems linked to just that computer. Curiosity is now operating on its B-side, as it did during part of the flight from Earth to Mars. The A-side was most recently used starting a few weeks before landing and continuing until Feb. 28, when engineers commanded a switch to the B-side in response to a memory glitch on the A-side. The A-side now is available as a backup if needed.

One aspect of ramping-up activities after switching to the B-side computer has been to check the six engineering cameras that are hard-linked to that computer. The rover's science instruments, including five science cameras, can each be operated by either the A-side or B-side computer, whichever is active. However, each of Curiosity's 12 engineering cameras is linked to just one of the computers. The engineering cameras are the Navigation Camera (Navcam), the Front Hazard-Avoidance Camera (Front Hazcam) and Rear Hazard-Avoidance Camera (Rear Hazcam). Each of those three named cameras has four cameras on it: two stereo pairs of cameras, with one pair linked to each computer. Only the pairs linked to the active computer can be used, and the A-side computer was active from before landing, in August, until Feb. 28.

"This was the first use of the B-side engineering cameras since April 2012, on the way to Mars," said JPL's Justin Maki, team lead for these cameras. "Now we've used them on Mars for the first time, and they've all checked out OK."

Engineers quickly diagnosed a software issue that prompted Curiosity to put itself into a precautionary standby "safe mode" on March 16, and they know how to prevent it from happening again. The rover stayed on its B-side while it was in safe mode and subsequently as science activities resumed.

Upcoming activities include preparations for a moratorium on transmitting commands to Curiosity from April 4 to May 1, while Mars will be passing nearly directly behind the sun from Earth's perspective. The moratorium is a precaution against possible interference by the sun corrupting a command sent to the rover.

NASA's Mars Science Laboratory project is using Curiosity and the rover's 10 science instruments to investigate the environmental history within Gale Crater, a location where the project has found that conditions were long ago favorable for microbial life. JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate in Washington.

More information about Curiosity is online at http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl andhttp://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at:http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity .

Leopards, Hyenas And Jackals: Wild And In The Backyard

A new study led by Wildlife Conservation Society (WCS)-India scientist Vidya Athreaya finds that certain landscapes of western India completely devoid of wilderness and with high human populations are crawling with a different kind of backyard wildlife: leopards.

Camera traps set up at night in a densely populated region of India virtually devoid of wilderness revealed leopards, striped hyenas, jackals -- and lots of people.

Credit: Project Waghoba

The study found as many as five adult large carnivores, including leopards and striped hyenas, per 100 square kilometers (38 square miles), a density never before reported in a human-dominated landscape.

Camera traps set up at night in a densely populated region of India virtually devoid of wilderness revealed leopards, striped hyenas, jackals -- and lots of people.

Credit: Project Waghoba

The study, called "Big Cats in Our Backyards," appeared in the March 6 edition of the journal PLoS One. Authors include: Vidya Athreya and Ullas Karanth of the Wildlife Conservation Society and Centre for Wildlife Studies in Bangalore; Morten Odden of Hedmark University College; John D. C. Linnell of the Norwegian Institute for Nature Research; and Jagdish Krishnaswamy of Asoka Trust for Research of Ecology in the Environment.

Using camera traps, the authors founds that leopards often ranged close to houses at night though remained largely undetected by the public. Despite this close proximity between leopards and people, there are few instances of attacks in this region. The authors also photographed rusty spotted cat, small Indian civet, Indian fox, jungle cat, jackal, mongoose – and a variety of people from the local communities. The research took place in western Maharashtra, India. 

Camera traps set up at night in a densely populated region of India virtually devoid of wilderness revealed leopards, striped hyenas, jackals -- and lots of people.

Credit: Project Waghoba

"Human attacks by leopards were rare despite a potentially volatile situation considering that the leopard has been involved in serious conflict, including human deaths in adjoining areas," said big cat expert Ullas Karanth of WCS. "The results of our work push the frontiers of our understanding of the adaptability of both humans and wildlife to each other's presence."

The authors say that the findings show that conservationists must look outside of protected areas for a more holistic approach to safeguarding wildlife in a variety of landscapes. 

The Wildlife Conservation Society saves wildlife and wild places worldwide. We do so through science, global conservation, education and the management of the world's largest system of urban wildlife parks, led by the flagship Bronx Zoo. Together these activities change attitudes towards nature and help people imagine wildlife and humans living in harmony. WCS is committed to this mission because it is essential to the integrity of life on Earth. Visit http://www.wcs.org.

 

Real Time Real-time Wireless Video Streaming from Mobile Device to Television

KAIST has developed a low-power 60 GHz radio frequency chip for mobile devices

  As the capacity of handheld devices increases to accommodate a greater number of functions, these devices have more memory, larger display screens, and the ability to play higher definition video files. If the users of mobile devices, including smartphones, tablet PCs, and notebooks, want to share or transfer data on one device with that of another device, a great deal of time and effort are needed.

Credit: KAIST

As a possible method for the speedy transmission of large data, researchers are studying the adoption of gigabits per second (Gbps) wireless communications operating over the 60 gigahertz (GHz) frequency band. Some commercial approaches have been introduced for full-HD video streaming from a fixed source to a display by using the 60 GHz band. But mobile applications have not been developed yet because the 60 GHz radio frequency (RF) circuit consumes hundreds of milliwatts (mW) of DC power.

Professor Chul Soon Park from the Department of Electrical Engineering at the Korea Advanced Institute of Science and Technology (KAIST) and his research team recently developed a low-power version of the 60 GHz radio frequency integrated circuit (RFIC). Inside the circuit are an energy-efficient modulator performing amplification as well as modulation and a sensitivity-improved receiver employing a gain boosting demodulator.

The research team said that their RFIC draws as little as 67 mW of power in the 60 GHz frequency band, consuming 31mW to send and 36mW to receive large volumes of data. RFIC is also small enough to be mounted on smartphones or notebooks, requiring only one chip (its width, length, and height are about 1 mm) and one antenna (4x5x1 mm3) for sending and receiving data with an integrated switch.

Professor Park, Director of the Intelligent Radio Engineering Center at KAIST, gave an upbeat assessment of the potential of RFIC for future applications:

"What we have developed is a low-power 60-GHz RF chip with a transmission speed of 10.7 gigabits per second. In tests, we were able to stream uncompressed full-HD videos from a smartphone or notebook to a display without a cable connection 

Our chip can be installed on mobile devices or even on cameras so that the devices are virtually connected to other devices and able to exchange large data with each other."

Contacts and sources:

Friday, March 29, 2013

Create Real Objects With Your Mind, Just By Thinking, A Child Can Do It

At Thinker Thing they are building a new type of process that requires no technical know how and that anyone can use, young or old . They are building a machine that can grow a model, using your mind.



3D Printing and the home manufacturing revolution will allow anyone to print out a real object from a 3d CAD model, there's just one major problem, who can design these 3D models? The software that these machines use is based on outdated concepts that take years to learn and master. How much of a revolution will it be if only specialists can create 3d objects. Do you want your child printing some 3D model created by a corporation or would you prefer them to be the creator of their own objects and not just another consumer. 

How is that even possible?
They create a DNA seed that defines the start point in an evolutionary chain for the object. Dinosaurs are very diverse, for example, but they can be traced back to a single common dna ancestor.We create this first DNA definition as the first building block from which all future objects evolve.The DNA of the object is then mutated over each generation, and how well that new mutations does, whether it lives or dies, is determined by the mind.
They detect the brain patterns of the user using an epoc neural headset and use that to to understand their emotional response to certain features in visual stimulus based on their evolution system. They can then determine the underlying DNA features that evoke responses and use that in a natural selection process to refine the next generation of objects.

In this way, over a short period, the user grows a model using their mind.

“Monster Dreamer” School Outreach Program.

The first of these machines, the “Monster Dreamer”, is a machine that will build fantastical creatures with your mind. Its construction has been fully funded by the Chilean government and development is on target, with several milestones already achieved.
On completion of the Monster Dreamer, the first people in the world to create objects with their mind will be children from the regional schools of Chile. Thinker Thing will be visiting over 8 regions of Chile, from the driest desert in the world to the end of the world in patagonia, inspiring and teaching complex scientific, art and engineering principles to very young children in remote rural regions via this engaging and fascinating project.

“ 


If you are a company and would like to sponsor the Monster Dreamer School Outreach Program or the Fantastical Mind Creatures of Chile Exhibition there are a number of options available which will associate your company with this incredible project. They are also actively seeking a Headline sponsor for the Fantastical Mind Creatures of Chile Exhibition that is not offered here. This is because as well as a contribution to the project they require a commitment to host the exhibition. If your company would be interested in this options please contact them directly on info@thinkerthing.com with the subject heading “Headline”.

At What Stage is the Project?
The project is on schedule and several important milestone have already been reached:

  • The first stage of the genetic system has been completed
  • A simple 3D object has been successfully grown with the mind using the genetic system and brain patterns from the neuroheadset.
  • They have an interpretive system working which interprets the bones structure created by the DNA into a recognizable form. Much in the same way a paleontologist determines the look of a dinosaur from its bones, their interpretive system generates a virtual skin around the abstracted bone system of their creature generated by the genetic system.
  • They have produced their first real 3d printed object arms from the interpretive system.
  • Mid April they will return to their test school in the Elqui valley to field refine their processes and their educational material.
  • End April they are on target to link all the systems together to produce a real 3d printed arm directly from the mind.
  • In May they expect to have the first prototype that can create a complete creature model using the mind.
  • At the start of June they will begin visiting the schools of Chile with their prototype.

Giant Robotic Jellyfish May Patrol The Ocean



Virginia Tech College of Engineering researchers have unveiled a life-like, autonomous robotic jellyfish the size and weight of a grown man, 5 foot 7 inches in length and weighing 170 pounds.

The prototype robot, nicknamed Cyro, is a larger model of a robotic jellyfish the same team – headed by Shashank Priya of Blacksburg, Va., and professor of mechanical engineering at Virginia Tech – unveiled in 2012. The earlier robot, dubbed RoboJelly, is roughly the size of a man's hand, and typical of jellyfish found along beaches.

Student team members from the Virginia Tech's National Science Foundation Center for Energy Harvesting Materials and Systems test a five-foot wide jellyfish-like robot under water at War Memorial Hall.

Credit: Amanda Loman, Virginia Tech

"A larger vehicle will allow for more payload, longer duration and longer range of operation," said Alex Villanueva of St-Jacques, New-Brunswick, Canada, and a doctoral student in mechanical engineering working under Priya. "Biological and engineering results show that larger vehicles have a lower cost of transport, which is a metric used to determine how much energy is spent for traveling."
Virginia Tech: Autonomous Robotic Jellyfish from virginiatech on Vimeo.

Both robots are part of a multi-university, nationwide $5 million project funded by U.S. Naval Undersea Warfare Center and the Office of Naval Research. The goal is to place self-powering, autonomous machines in waters for the purposes of surveillance and monitoring the environment, in addition to other uses such as studying aquatic life, mapping ocean floors, and monitoring ocean currents.

Jellyfish are attractive candidates to mimic because of their ability to consume little energy owing to a lower metabolic rate than other marine species. Additionally, they appear in wide variety of sizes, shapes and colors, allowing for several designs. They also inhabit every major oceanic area of the world and are capable of withstanding a wide range of temperatures in both fresh and salt waters. Most species are found in shallow coastal waters, but some have been found in depths 7,000 meters below sea level.

Partner universities in the project are Providence College in Rhode Island, the University of California Los Angeles, the University of Texas at Dallas, and Stanford University. Priya's team is building the jellyfish body models, integrating fluid mechanics and developing control systems.

Cyro is modeled and named after the jellyfish Cyanea capillata, Latin for Llion's Manemain jellyfish. Jellyfish, with "Cyro" derived from "cyanea" and "robot." As with its predecessor, this robot is in the prototype stage, years away from use in waters. A new prototype model already is under construction at Virginia Tech's Durham Hall, where Priya's Center for Energy Harvesting Materials and Systems is based.

"We hope to improve on this robot and reduce power consumption and improve swimming performance as well as better mimic the morphology of the natural jellyfish," Villanueva said, adding that the project also allows researchers such as himself to better understand aquatic creatures live. "Our hopes for Cyro's future is that it will help understand how the propulsion mechanism of such animal scales with size."

A stark difference exists between the larger and smaller robots. Cyro is powered by a rechargeable nickel metal hydride battery, whereas the smaller models were tethered, Priya said. Experiments have also been conducted on powering jellyfish with hydrogen but there is still much research to be done in that area.

In both cases, the jellyfish must operate on their own for months or longer at a time as engineers likely won't be able to capture and repair the robots, or replace power sources.

"Cyro showed its ability to swim autonomously while maintaining a similar physical appearance and kinematics as the natural species," Priya said, adding that the robot is simultaneously able to collect, store, analyze, and communicate sensory data. This autonomous operation in shallow water conditions is already a big step towards demonstrating the use of these creatures."

How does the robot swim? Its body consists of a rigid support structure with direct current electric motors which control the mechanical arms that are used in conjunction with an artificial mesoglea, or jelly-based pulp of the fish's body, creating hydrodynamic movement.

With no central nervous system, jellyfish instead use a diffused nerve net to control movement and can complete complex functions. A parallel study on a bio-inspired control system is in progress which will eventually replace the current simplified controller.

As with the smaller models, Cyro's skin is comprised of a thick layer of silicone, squishy in one's hand. It mimics the sleek jellyfish skin and is placed over a bowl-shaped device containing the electronic guts of the robot. When moving, the skin floats and moves with the robot, looking weirdly alive.

"It has been a great experience to finally realize the biomimetic and bio-inspired robotic vehicles," Priya said. "Nature has too many secrets and we were able to find some of them but many still remain. We hope to find a mechanism to continue on this journey and resolve the remaining puzzles."

Contacts and sources:
Steven Mackay
Virginia Tech

Mathematician And Guru Posts Predictions For Baseballs Six Divisions

It looks like 2013 will be a thrilling season for baseball fans as four of the six divisions can be expected to deliver tight races, says baseball guru NJIT Associate Professor and Associate Dean Bruce Bukiet. Over the years, Bukiet has applied mathematical analysis to compute the number of regular season games each Major League Baseball team should win. Though his expertise is in mathematical modeling, his projections have compared well with those of so-called experts.

Fenway Park
File:Fenway from Legend's Box.jpg

The numbers indicate that only one game might separate the first and second place teams in both the National League's (NL) East and West divisions, with the Atlanta Braves (94 wins) edging out the Washington Nationals (93 wins) in the East and the Los Angeles Dodgers (88 wins) coming in just ahead of the San Francisco Giants (87 wins) in the West. Even in the NL Central, the St. Louis Cardinals (90 wins) don't have much breathing room, winning that division by a projected 3 games over the Cincinnati Reds (87 wins). The Braves, Nationals, Cards, Reds and Dodgers should make the playoffs, while the Giants miss by a single game.
It is hard to believe that in the American League (AL), the contests could be even closer. While the Detroit Tigers should have the best record in baseball (102 wins) and run away with the Central division, with the next best team (the Chicago White Sox) more than 20 wins behind, the other two divisions could end up in ties. In the AL West, Bukiet has the Anaheim Angels and the Oakland Athletics tied with 92 wins each, while in the AL East, he says there could be a 3-way tie!!! The guru predicts that the Toronto Blue Jays, the Tampa Bay Rays and the New York Yankees all will win 87 games. Such results would mean that the Tigers, Angels, and Athletics would make the playoffs, while the other two teams to make the playoffs would be from among the Blue Jays, Rays, Yankees or Texas Rangers, all whom the model show come in at 87 wins.
Bukiet makes these projections to demonstrate and promote the power of math. He wants to show young people that math can be fun, that it can be applied to improve one's understanding of many aspects of life and that if you love mathematics, it can be a great college major and lead to a satisfying career.

Bukiet bases his predictions on a mathematical model he developed in 2000. He has made revisions over the years. His results have led to back-to-back wins for himself in 2010-2011 as predictions champ at baseballphd.net. See more results for his baseball modeling, including projected wins for each of the 30 Major League Baseball teams, at http://m.njit.edu/~bukiet/baseball/baseball.html and at http://www.egrandslam.com.

Bukiet should have plenty of time this summer to spend doing math since once again his favorite team, the New York Mets, should win the same number of games (74) as they did last year. Once again they should come in fourth in their division, while the Miami Marlins have the worst record in the NL with 59 wins. The worst team overall should be the Houston Astros in their debut in the AL with only 56 successful outcomes and 106 losses. Yes, and once again, for the 21th year in a row, the Pittsburgh Pirates should finish with a losing record.
 

Contacts and sources:
Sheryl Weinstein
New Jersey Institute of Technology

Biological Transistor Enables Computing Within Living Cells, Study Says



When Charles Babbage prototyped the first computing machine in the 19th century, he imagined using mechanical gears and latches to control information. ENIAC, the first modern computer developed in the 1940s, used vacuum tubes and electricity. Today, computers use transistors made from highly engineered semiconducting materials to carry out their logical operations.

And now a team of Stanford University bioengineers has taken computing beyond mechanics and electronics into the living realm of biology. In a paper published March 28 in Science, the team details a biological transistor made from genetic material — DNA and RNA — in place of gears or electrons. The team calls its biological transistor the “transcriptor."

The biological transistor developed by Jerome Bonnet and colleagues could be used inside living cells to record when cells have been exposed to certain external stimuli, or even to turn on and off cell reproduction as needed.
description of photo
Credit: Steve Fisch

“Transcriptors are the key component behind amplifying genetic logic — akin to the transistor and electronics,” said Jerome Bonnet, PhD, a postdoctoral scholar in bioengineering and the paper’s lead author.

The creation of the transcriptor allows engineers to compute inside living cells to record, for instance, when cells have been exposed to certain external stimuli or environmental factors, or even to turn on and off cell reproduction as needed.

“Biological computers can be used to study and reprogram living systems, monitor environments and improve cellular therapeutics,” said Drew Endy, PhD, assistant professor of bioengineering and the paper’s senior author.

The biological computer

In electronics, a transistor controls the flow of electrons along a circuit. Similarly, in biologics, a transcriptor controls the flow of a specific protein, RNA polymerase, as it travels along a strand of DNA.

“We have repurposed a group of natural proteins, called integrases, to realize digital control over the flow of RNA polymerase along DNA, which in turn allowed us to engineer amplifying genetic logic,” said Endy.

Using transcriptors, the team has created what are known in electrical engineering as logic gates that can derive true-false answers to virtually any biochemical question that might be posed within a cell.

They refer to their transcriptor-based logic gates as “Boolean Integrase Logic,” or “BIL gates” for short.

Transcriptor-based gates alone do not constitute a computer, but they are the third and final component of a biological computer that could operate within individual living cells.

Despite their outward differences, all modern computers, from ENIAC to Apple, share three basic functions: storing, transmitting and performing logical operations on information.

Last year, Endy and his team made news in delivering the other two core components of a fully functional genetic computer. The first was a type of rewritable digital data storage within DNA. They also developed a mechanism for transmitting genetic information from cell to cell, a sort of biological Internet.

It all adds up to creating a computer inside a living cell.

Drew Endy

Boole’s gold

Digital logic is often referred to as “Boolean logic,” after George Boole, the mathematician who proposed the system in 1854. Today, Boolean logic typically takes the form of 1s and 0s within a computer. Answer true, gate open; answer false, gate closed. Open. Closed. On. Off. 1. 0. It’s that basic. But it turns out that with just these simple tools and ways of thinking you can accomplish quite a lot.

“AND” and “OR” are just two of the most basic Boolean logic gates. An “AND” gate, for instance, is “true” when both of its inputs are true — when “a” and “b” are true. An “OR” gate, on the other hand, is true when either or both of its inputs are true.

In a biological setting, the possibilities for logic are as limitless as in electronics, Bonnet explained. “You could test whether a given cell had been exposed to any number of external stimuli — the presence of glucose and caffeine, for instance. BIL gates would allow you to make that determination and to store that information so you could easily identify those which had been exposed and which had not,” he said.

By the same token, you could tell the cell to start or stop reproducing if certain factors were present. And, by coupling BIL gates with the team’s biological Internet, it is possible to communicate genetic information from cell to cell to orchestrate the behavior of a group of cells.

“The potential applications are limited only by the imagination of the researcher,” said co-author Monica Ortiz, a PhD candidate in bioengineering who demonstrated autonomous cell-to-cell communication of DNA encoding various BIL gates.

Building a transcriptor

To create transcriptors and logic gates, the team used carefully calibrated combinations of enzymes — the integrases mentioned earlier — that control the flow of RNA polymerase along strands of DNA. If this were electronics, DNA is the wire and RNA polymerase is the electron.

“The choice of enzymes is important,” Bonnet said. “We have been careful to select enzymes that function in bacteria, fungi, plants and animals, so that bio-computers can be engineered within a variety of organisms.”

On the technical side, the transcriptor achieves a key similarity between the biological transistor and its semiconducting cousin: signal amplification.

With transcriptors, a very small change in the expression of an integrase can create a very large change in the expression of any two other genes.

To understand the importance of amplification, consider that the transistor was first conceived as a way to replace expensive, inefficient and unreliable vacuum tubes in the amplification of telephone signals for transcontinental phone calls. Electrical signals traveling along wires get weaker the farther they travel, but if you put an amplifier every so often along the way, you can relay the signal across a great distance. The same would hold in biological systems as signals get transmitted among a group of cells.

“It is a concept similar to transistor radios,” said Pakpoom Subsoontorn, a PhD candidate in bioengineering and co-author of the study who developed theoretical models to predict the behavior of BIL gates. “Relatively weak radio waves traveling through the air can get amplified into sound.”
Public-domain biotechnology

To bring the age of the biological computer to a much speedier reality, Endy and his team have contributed all of BIL gates to the public domain so that others can immediately harness and improve upon the tools.

“Most of biotechnology has not yet been imagined, let alone made true. By freely sharing important basic tools everyone can work better together,” Bonnet said.

The research was funded by the National Science Foundation and the Townshend Lamarre Foundation.

Information about Stanford’s Department of Bioengineering, which also supported the work, is available at http://bioengineering.stanford.edu. The department is jointly operated by the School of Engineering and the School of Medicine.

Contacts and sources: 
Andrew Meyers

NASA's Swift Sizes Up Comet ISON

Astronomers from the University of Maryland at College Park (UMCP) and Lowell Observatory have used NASA's Swift satellite to check out comet C/2012 S1 (ISON), which may become one of the most dazzling in decades when it rounds the sun later this year.

Using images acquired over the last two months from Swift's Ultraviolet/Optical Telescope (UVOT), the team has made initial estimates of the comet's water and dust production and used them to infer the size of its icy nucleus.

"Comet ISON has the potential to be among the brightest comets of the last 50 years, which gives us a rare opportunity to observe its changes in great detail and over an extended period," said Lead Investigator Dennis Bodewits, an astronomer at UMCP.

Comet ISON is now approaching the inner solar system. Discovered last year, the comet remains unusually active for its distance from the sun. If current trends continue, ISON could rank as one of the brightest comets in decades when it makes its close approach to the sun in late November. This animation shows the comet's approach and departure from the inner solar system from various perspectives.

Credit: NASA's Goddard Space Flight Center Scientific Visualization Studio
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Additional factors, including an encounter with Mars followed by a scorching close approach to the sun, make comet ISON an object of special interest. In late February, at NASA's request, a team of comet experts initiated the Comet ISON Observing Campaign (CIOC) to assist ground- and space-based facilities in obtaining the most scientifically useful data.

Like all comets, ISON is a clump of frozen gases mixed with dust. Often described as "dirty snowballs," comets emit gas and dust whenever they venture near enough to the sun that the icy material transforms from a solid to gas, a process called sublimation. Jets powered by sublimating ice also release dust, which reflects sunlight and brightens the comet.

Typically, a comet's water content remains frozen until it comes within about three times Earth's distance to the sun. While Swift's UVOT cannot detect water directly, the molecule quickly breaks into hydrogen atoms and hydroxyl (OH) molecules when exposed to ultraviolet sunlight. The UVOT detects light emitted by hydroxyl and other important molecular fragments as well as sunlight reflected from dust.

The Ultraviolet/Optical Telescope aboard NASA's Swift imaged comet ISON (center) on Jan. 30, when it was located about 3.3 degrees from the bright star Castor in the constellation Gemini. At the time of this 5.5-minute optical exposure, ISON was about 5,000 times fainter than the limit of human vision.

Credit: NASA/Swift/D. Bodewits, UMCP

The Jan. 30 UVOT observations reveal that ISON was shedding about 112,000 pounds (51,000 kg) of dust, or about two-thirds the mass of an unfueled space shuttle, every minute. By contrast, the comet was producing only about 130 pounds (60 kg) of water every minute, or about four times the amount flowing out of a residential sprinkler system.

"The mismatch we detect between the amount of dust and water produced tells us that ISON's water sublimation is not yet powering its jets because the comet is still too far from the sun," Bodewits said. "Other more volatile materials, such as carbon dioxide or carbon monoxide ice, evaporate at greater distances and are now fueling ISON's activity."

At the time, the comet was 375 million miles (604 million km) from Earth and 460 million miles (740 million km) from the sun. ISON was at magnitude 15.7 on the astronomical brightness scale, or about 5,000 times fainter that the threshold of human vision.

Similar levels of activity were observed in February, and the team plans additional UVOT observations.

While the water and dust production rates are relatively uncertain because of the comet's faintness, they can be used to estimate the size of ISON's icy body. Comparing the amount of gas needed for a normal comet to blow off dust at the rate observed for ISON, the scientists estimate that the nucleus is roughly 3 miles (5 km) across, a typical size for a comet. This assumes that only the fraction of the surface most directly exposed to the sun, about 10 percent of the total, is actively producing jets.

An important question is whether ISON will continue to brighten at the same pace once water evaporation becomes the dominant source for its jets. Will the comet sizzle or fizzle?

"It looks promising, but that's all we can say for sure now," said Matthew Knight, an astronomer at Lowell Observatory in Flagstaff, Ariz., and a member of the Swift and CIOC teams. "Past comets have failed to live up to expectations once they reached the inner solar system, and only observations over the next few months will improve our knowledge of how ISON will perform."

From now through October, comet ISON tracks through the constellations Gemini, Cancer and Leo as it falls toward the sun.

Credit: NASA's Goddard Space Flight Center/Axel Mellinger

Based on ISON's orbit, astronomers think the comet is making its first-ever trip through the inner solar system. Before beginning its long fall toward the sun, the comet resided in the Oort comet cloud, a vast shell of perhaps a trillion icy bodies that extends from the outer reaches of the planetary system to about a third of the distance to the star nearest the sun.

Formally designated C/2012 S1 (ISON), the comet was discovered on Sept. 21, 2012, by Russian astronomers Vitali Nevski and Artyom Novichonok using a telescope of the International Scientific Optical Network located near Kislovodsk.

The first of several intriguing observing opportunities occurs on Oct. 1, when the inbound comet passes about 6.7 million miles (10.8 million km) from Mars.

"During this close encounter, comet ISON may be observable to NASA and ESA spacecraft now working at Mars," said Michael Kelley, an astronomer at UMCP and also a Swift and CIOC team member. "Personally, I'm hoping we'll see a dramatic postcard image taken by NASA's latest Mars explorer, the Curiosity rover."

Fifty-eight days later, on Nov. 28, ISON will make a sweltering passage around the sun. The comet will approach within about 730,000 miles (1.2 million km) of its visible surface, which classifies ISON as a sungrazing comet. In late November, its icy material will furiously sublimate and release torrents of dust as the surface erodes under the sun's fierce heat, all as sun-monitoring satellites look on. Around this time, the comet may become bright enough to glimpse just by holding up a hand to block the sun's glare.

Sungrazing comets often shed large fragments or even completely disrupt following close encounters with the sun, but for ISON neither fate is a forgone conclusion.

"We estimate that as much as 10 percent of the comet's diameter may erode away, but this probably won't devastate it," explained Knight. Nearly all of the energy reaching the comet acts to sublimate its ice, an evaporative process that cools the comet's surface and keeps it from reaching extreme temperatures despite its proximity to the sun.

Following ISON's solar encounter, the comet will depart the sun and move toward Earth, appearing in evening twilight through December. It will swing past Earth on Dec. 26, approaching within 39.9 million miles (64.2 million km) or about 167 times farther than the moon.

Whether we'll look back on ISON as a "comet of the century" or as an overhyped cosmic dud remains to be seen, but astronomers are planning to learn the most they can about this unusual visitor no matter what happens.

Contacts and sources:
NASA 

Wednesday, March 27, 2013

Programming Synthetic Life: The Coming Biology Revolution

Thirty years ago, the future lay in programming computers. Today, it’s programming cells.

That was the message of panelists at a session  (March 25) in Stanley Hall auditorium titled “Programming Life: the revolutionary potential of synthetic biology.” Co-presented by UC Berkeley’s Synthetic Biology Engineering Research Center (SynBERC) and Discover magazine, the panels brought together a dozen of synthetic biology’s pioneers from academia and industry, in addition to ethicists focused on the societal impact of the technology.

Jay Keasling (left), director of SynBERC, and moderator Corey Powell of Discover listen as Monsanto scientist Virginia Ursin explains the company’s interest in synthetic biology.
 Christine Fu photo.

Keynote speaker Juan Enriquez, a self-described “curiosity expert” and co-founder of the company Synthetic Genomics, compared the digital revolution spawned by thinking of information as a string of ones and zeros to the coming synthetic biology revolution, premised on thinking about life as a mix of interchangeable parts – genes and gene networks – that can be learned and manipulated like any language.

At the moment, this genetic manipulation, a natural outgrowth of genetic engineering, focuses on altering bacteria and yeast to produce products they wouldn’t normally make, such as fuels or drugs. “To do with biology what you would do if you were designing a piece of software,” according to moderator Corey Powell, editor at large of Discover, which plans to publish a story about the conference and post the video online.

UC Berkeley chemical engineer Jay Keasling has been a key player in developing the field of synthetic biology over the last decade. Enriquez introduced Keasling as someone “who in his spare time goes out and tries to build stuff that will cure malaria, and biofuels and the next generation of clean tech, all while mentoring students at this university and at the national labs and creating whole new fields of science.”

Keasling, director of SynBERC, a UC Berkeley-led multi-institution collaboration that is laying the foundations for the field, expressed excitement about the newest development: the release next month by the pharmaceutical company sanofi aventis of a synthetic version of artemsinin, “the world’s best antimalarial drug,” he said. Sparked by discoveries in Keasling’s lab more than a decade ago, the drug is produced by engineered yeast and will be the first product from synthetic biology to reach the market.

“There are roughly 300 to 500 million cases of malaria each year,” he said. “Sanofi will initially produce about 100 million treatments, which will cover one-third to one-quarter of the need.”

Biofuels from yeast

As CEO of the Joint BioEnergy Institute, Keasling is now focused on engineering microbes to turn “a billion tons of biomass that go unutilized in the U.S. on an annual basis … into fuel, producing roughly a third of the need in the U.S.”

But other advances are on the horizon, he said, such as engineering new materials and engineering “green” replacements for all the products now made from petroleum. “Some of these have the potential to significantly reduce our carbon footprint, by say, 80 percent,” he said.

Ursin, Keasling and Steve Evans of Dow AgroSciences discuss the economic potential of synthetic biology with Discover magazine’s Corey Powell.
Christine Fu photo.

Virginia Ursin, Technology Prospecting Lead and Science Fellow at Monsanto Corp., noted that industry sees synthetic biology’s triumphs as being 10-20 years down the road, but anticipated, for example, producing enzymes used in manufacturing or even engineering microbes that live on plants to improve plant growth.

“Engineering (microbes) to increase their impact on (plant) health or protection against disease is probably going to be one of the nearer term impacts of synthetic biology on agriculture,” she said. Ultimately, she said, the field could have a revolutionary impact on agriculture similar to the green revolution sparked by the development of chemical fertilizers.

But the implications of being able to engineer cells go deeper, according to Enriquez.

“This isn’t just about economic growth, this is also about where we are going as a human species,” he said. Humans will no longer merely adapt to or adopt the environment, but “begin to understand how life is written, how life is coded, how life is copied, and how you can rewrite life.”

Scientists’ moral choices

Directly guiding “the evolution of microbes, bacteria, plants, animals and even ourselves,” as Enriquez put it, sounds like science fiction. George Church, a biologist at Harvard Medical School, suggested that we might want to bring back extinct animals, such as the mammoth to help restore Arctic permafrost disintegrating under the impact of global warming.

In response, ethicist Laurie Zoloth of Northwestern University urged caution in exploiting the technology of synthetic biology.

“You could change the world, and you have a powerful technology,” she said. “I am more interested in what this technology makes of the women and men doing it. What sorts of interior moral choices they need to be making and how you create scientists who aren’t only good at all these technical skills but very good at asking and thinking seriously about ethical and moral questions and coming to terms with the implications of their work.”

Given the current crises of climate change and ecological change, she added, “frankly, without this work, I don’t think we have such great answers for (them).”

Church acknowledged that “we have an obligation to do it right. But because our environment, our world is changing, the decision to do nothing is a gigantic risk. The decision to do a particular new thing is a risk. We have to get better at risk assessment and safety engineering.”

Drew Endy, a bioengineering professor at Stanford, summed up his hopes for synthetic biology. “What I would like to imagine as a longer-term encompassing vision is that humanity figured out how to reinvent the manufacturing of the things we need so that we can do it in partnership with nature; not to replace nature, but to dance better with it in sustaining what it means to be a flourishing human civilization.”

Contacts and sources:
By Robert Sanders,
University of California Berkeley

Semiconductor Sensors For Biosensing To Airport Security Scanners


Many users of microwave ovens have had the frightening experience of leaving a fork, crumpled piece of aluminum foil or some other pointy metal item inside the cooking chamber. The sharp metal object acts as an antenna for the oven’s microwave radiation, causing strong local heating or sparking. 

Jing Hua Teng from the A*STAR Institute of Materials Research and Engineering (IMRE) and colleagues in Singapore and the UK have now observed a similar antenna effect, involving a different sort of electromagnetic radiation — known as terahertz (THz) radiation — in a microfabricated semiconductor structure. Their discovery could find application in areas ranging from biosensing to airport security scanners.

Terahertz radiation is greatly enhanced in the tiny V-shaped gap, just a fraction of a micrometer wide, between pairs of touching semiconductor disks.
Credit: Ref. 1 © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Teng and his co-workers developed tiny semiconductor structures made of the chemical elements indium and antimony. From this material, they produced disks of 20 micrometers in diameter, which they arranged such that pairs just touched. The gap between contiguous disks was merely tens to hundreds of nanometers wide (see image). When the researchers exposed the structures to THz radiation, they found that the radiation intensity in the gap was enhanced by more than a hundred times.

Confining and enhancing THz radiation is significant for two reasons, according to Teng. First, electromagnetic waves in the THz range can be used in a broad range of applications, for example, to study the structure of large biomolecules. As this sort of radiation can penetrate textiles but is less energetic than X-rays — or microwaves — it is also well suited for use in body scanners at airports. 

The second reason as to why the new results are important is more fundamental. “We have produced this particular touching-disk structure to test, in the THz regime, intriguing theoretical predictions made for optical radiation,” explains Teng. “Building a device such as ours for visible light is much more challenging, as it would involve even smaller structures.”

The now-verified theoretical predictions came from collaborators at Imperial College London in the UK. “For the present work, IMRE is in charge of the materials growth and the structure fabrication, while Imperial College contributes structure design and characterization,” says Teng. The A*STAR researchers are now focused on practical applications: they will further explore the unique properties of their semiconductor materials and try to develop devices for THz technology. The group has already succeeded in tuning the THz response of their structure2, meaning that they can conveniently adjust the frequency response of their device for different applications.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering


Contacts and sources:
 The Agency for Science, Technology and Research (A*STAR)
A*STAR Research
Institute of Materials Research and Engineering
Link to research paper - Broadband Terahertz Plasmonic Response of Touching InSb Disks
Direct Optical Tuning of the Terahertz Plasmonic Response of InSb Subwavelength Gratings

Journal information: Hanham, S. M., Fernández-Domínguez, A. I., Teng, J. H., Ang, S. S., Lim, K. P. et al. Broadband terahertz plasmonic response of touching InSb disks. Advanced Materials 24, OP226–OP230 (2012). Deng, L., Teng, J. H., Liu, H., Wu, Q. Y., Tang, J. et al. Direct optical tuning of the terahertz plasmonic response of InSb subwavelength gratings. Advanced Optical Materials 1, 128–132 (2013).
 

Microscale Sensors Inserted Under The Skin Powered Wirelessly By External Handheld Receiver

Microscale medical sensors inserted under the skin can be powered wirelessly by an external handheld receiver

Implantable electronic devices potentially offer a rapid and accurate way for doctors to monitor patients with particular medical conditions. Yet powering such devices remains a fundamental challenge: batteries are bulky and eventually need recharging or replacing. Jia Hao Cheong at the A*STAR Institute for Microelectronics, Singapore, and his co-workers are developing an alternative approach that eliminates the need for a battery. Their miniature devices are based on wireless power-transfer technology.

A handheld reader (top right) wirelessly powers and interrogates a tiny blood-pressure sensor embedded inside a prosthetic graft, inserted in this case as a conduit for haemodialysis in a patient with kidney failure.



Copyright : 2013 A*STAR Institute of Microelectronics

The research team has developed a microscale electronic sensor to monitor blood flow through artificial blood vessels. Surgeons use these prosthetic grafts to bypass diseased or clogged blood vessels in patients experiencing restricted blood supply, for example. Over time, however, the graft can also become blocked. To avoid complete failure, blood flow through the graft must be monitored regularly, but existing techniques are slow and costly.

These limitations prompted the researchers to develop a bench-top prototype of a device that could be incorporated inside a graft to monitor blood flow. The implant is powered by a handheld external reader, which uses inductive coupling to wirelessly transfer energy, a technology similar to that found in the latest wireless-charging mobile phones. The team developed an application-specific, integrated circuit for the implant designed for low power use (see image).

The incoming energy powers circuits in the device that control sensors based on silicon nanowires. This material is piezoresistive: as blood flows over the sensor the associated mechanical stresses induce a measurable increase in electrical resistance, proportional to the flow pressure.

Key to the success of the device is its ability to work with a very limited power supply. Most of the incoming energy is absorbed by skin and tissue before it can reach the implant, which may be inserted up to 50 millimeters deep.

“Our flow sensor system achieves an ultra-low power consumption of 12.6 microwatts,” Cheong says. For example, the sensor transmits its data to the handheld reader passively, by backscattering some of the incoming energy. “We have tested our system with 50-millimeter-thick tissue between the external coil and implantable coil, and it successfully extracted the pressure data from the implantable device,” he adds.

Cheong and his co-workers’ tests showed that the prototype sensor was also highly pressure sensitive, providing pressure readings with a resolution of 0.17 pounds per square inch (1,172 pascals). “The next step of the project is to integrate the system and embed it inside a graft for [an experimental] animal,” Cheong says.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics

Contacts and souces: 
A*STAR Research
 Institute of Microelectronics
Link to research paper - An Inductively Powered Implantable Blood Flow Sensor Microsystem for Vascular Grafts

Journal information: Cheong, J. H., Ng, S. S. Y., Liu, X., Xue, R.-F., Lim, H. J. et al. An inductively powered implantable blood flow sensor microsystem for vascular grafts. IEEE Transactions on Biomedical Engineering 59, 2466–2475 (2012).

How To Build A Really, Really Big Star

Stars 10 times as massive as the Sun, or more, should not exist: as they grow, they tend to push away the gas they feed on, starving their own growth.

Scientists have been struggling to figure out how some stars overcome this hurdle.


Image of the ESA/PACS & SPIRE consortium, courtesy Alana Rivera-Ingraham and Peter Martin

Now, a group of researchers led by two astronomers at the University of Toronto suggests that baby stars may grow to great mass if they happen to be born within a corral of older stars –with these surrounding stars favorably arranged to confine and feed gas to the younger ones in their midst.

The astronomers have seen hints of this collective feeding, known as “convergent constructive feedback,” in a giant cloud of gas and dust called Westerhout 3 (W3), located 6,500 light years from us.

Their results are published in April in The Astrophysical Journal.

“This observation may lift the veil on the formation of the most massive stars which remains, so far, poorly understood,” says Alana Rivera-Ingraham, who led the study while she was a graduate student in the Department of Astronomy and Astrophysics at U of T. Rivera-Ingraham is now a postdoctoral researcher at the Institut de Recherche en Astrophysique et Planétologie in Toulouse, France.

To study the formation of high-mass stars, Rivera-Ingraham and collaborators used high-quality and high-resolution far-infrared images from a space telescope launched by the European Space Agency in 2009 —the Herschel Space Observatory. This telescope’s two cameras recorded light that is not visible to the naked eye, spanning a range from infrared radiation partway to the microwave region. Exploiting these cameras, scientists including Peter Martin, professor in the Canadian Institute for Theoretical Astrophysics at the University of Toronto, created something called the HOBYS Key Programme to study the birth of very massive stars in nearby giant clouds of gas and dust in our own Galaxy, including W3. Research on HOBYS at the University of Toronto is supported in part by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada.

Scientists track the regions of the gas cloud where stars are about to form by mapping the density of dust and its temperature, looking for the most dense regions where the dust is shielded and cold.

“We can now see where stars are about to be born before it even happens, because we can detect the cold dust condensations,” says Martin. “Until Herschel, we could only dream of doing that.”

Stars are born in the denser parts of gas clouds, where the gas gets compressed enough by gravity to trigger nuclear fusion. The more massive the newborn star, the more visible and ultraviolet light it emits, heating up its surroundings —including the dust studied by Herschel.

“The radiation during the birth of high-mass stars is so intense that it tends to destroy and push away the material from which they need to feed for further growth,” says Rivera-Ingraham.

Scientists have modeled this process and found that stars about eight times the mass of our Sun would stop growing because they run out of gas.

But astronomers do see stars that are more massive than this theoretical limit. And by looking at W3, Rivera-Ingraham and her collaborators have found clues to how this might be possible.

The researchers noticed that the densest region of the cloud, in the upper left of the image, was surrounded by a congregation of old high-mass stars. It is as if previous generations of large stars enabled the next ones to grow also massive, and close to each other. The scientists suggest that this is no coincidence: each generation of stars might have created the right conditions for another generation to grow comparably or even more massive in its midst, ultimately leading to the formation of a rare, massive cluster of high-mass stars.

Like young high-mass stars, older stars also radiate and push gas away. If such older stars happen to be arranged favorably around a major reservoir of gas, they can compress it enough to ignite new stars. The process is similar to the way a group of street cleaners armed with leaf blowers can stack leaves in a pile—by pushing from all sides at the same time. This corralling of dense gas can give birth to new, high-mass stars.

A large newborn star will push its food source away, but if it is surrounded by enough large stars, these can keep nudging gas back at it. With such collective feeding at play, the young star could grow very massive indeed.

Next on the to-do list of the astronomers is to test their idea by simulating the situation with computer modeling, by measuring gas motions, and by comparing their results with data from other giant clouds studied by HOBYS. Only then will they be able to discern the mechanism—collective feeding or not—that gives rise to high-mass stars in these giant clouds.



This image does not show any stars because the Herschel Space Observatory’s cameras record far-infrared light instead of visible light. Gas is not visible either, even though it makes up most of the 400,000 solar masses of matter in this cloud: dust amounts to only about one per cent of the mass.

The side of this image spans about two degrees, or four times the diameter of the moon. At the cloud’s distance of 6,500 light years, this corresponds to about 230 light years. North is up and East is to the left.

This three-colour image of W3 uses visible colours to depict far-infrared radiation of different wavelengths, combining the Herschel bands at 70 μm (depicted in blue), 160 μm (depicted in green) and 250 μm (depicted in red). Hotter structures emit more strongly at shorter wavelengths. Red represents very cold shielded dust structures with equilibrium temperature about 10 degrees Kelvin (10 degrees above absolute zero, or -263 degrees Celsius), while blue is somewhat warmer at around 30 degrees Kelvin, with yellow in between.

Compared to the right side of the cloud which is cold and red, the left side glows yellow, because it is heated by the radiation coming from high-mass hot stars off to the left, just outside the field of view of the image.

While different colours correspond to different temperatures, brightness records the quantity of dust. Before Herschel’s two cutting-edge cameras, such a precise determination of the temperature and quantity of dust has been impossible. This capability, combined with the high resolution of Herschel, is exploited by the HOBYS Key Programme to study the early stages of formation of stars more than ten times as massive as the Sun.

Contacts and sources:
Johannes Hirn
University of Chicago