Better Security for Web and Mobile Applications

Called RockSalt, the clever bit of code can verify that native computer programming languages comply with a particular security policy.

Presented at the ACM Conference on Programming Language Design and Implementation (PLDI) in Beijing, in June, RockSalt was created by Greg Morrisett, Allen B. Cutting Professor of Computer Science at the Harvard School of Engineering and Applied Sciences (SEAS), two of his undergraduate students Edward Gan '13 and Joseph Tassarotti '13, former postdoctoral fellow Jean-Baptiste Tristan (now at Oracle), and Gang Tan of Lehigh University.

"When a user opens an external application, such as Gmail or Angry Birds, web browsers such as Google Chrome typically run the program's code in an intermediate and safer language such as JavaScript," says Morrisett. "In many cases it would be preferable to run native machine code directly."

The use of native code, especially in an online environment, however, opens up the door to hackers who can exploit vulnerabilities and readily gain access to other parts of a computer or device. An initial solution to this problem was offered over a decade ago by computer scientists at the University of California, Berkeley, who developed software fault isolation (SFI).

SFI forces native code to "behave" by rewriting machine code to limit itself to functions that fall within particular parameters. This "sandbox process" sets up a contained environment for running native code. A separate "checker" program can then ensure that the executable code adheres to regulations before running the program.

While considered a major breakthrough, the solution was limited to devices using RISC chips, a processor more common in research than in consumer computing. In 2006, Morrisett developed a way to implement SFI on the more popular CISC-based chips, like the Intel x86 processor. The technique was adopted widely. Google modified the routine for Google Chrome, eventually developing it into Google Native Client (or "NaCl").

When bugs and vulnerabilities were found in the checker for NaCl, Google sent out a call to arms. Morrissett once again took on the challenge, turning the problem into an opportunity for his students. The result was RockSalt, an improvement over NaCl, built using Coq, a proof development system.

"We built a simple but incredibly powerful system for proving a hypothesis -- so powerful that it's likely to be overlooked. We want to prove that if the checker says 'yes,' the code will indeed respect the sandbox security policy," says Joseph Tassarotti '13, who built and tested a model of the execution of x86 instructions. "We wanted to get a guarantee that there are no bugs in the checker, so we set out to construct a rigorous, machine-checked proof that the checker is correct."

"Our proofs about the correctness of our own tool say that if you run the tool on a program, and it says it's safe to run, then according to the model, this program can only do certain things," Tassarotti adds. "Our proof, however, was only as good as this model. If the model was wrong, then the tool could potentially have an error."

In other words, he explains, think of an analogy in physics. While you might mathematically prove that according to Newton's laws, a moving object will follow a certain trajectory, the proof is only meaningful to the degree that Newton's laws accurately model the world.

"Since the x86 architecture is very complicated, it was essential to test the model by running programs on a real chip, then simulating them with the model, and seeing whether the results matched. I specified the meanings of many of these instructions and developed the testing infrastructure to check for errors in the model," Tassarotti says.

Even more impressively, RockSalt comprises a mere 80 lines of code, as compared to the 600 lines of the original Google native code checker. The new checker is also faster, and, to date, no vulnerabilities have been uncovered. The tool offers tremendous advantages to programmers and users alike, allowing programmers to code in any language, compile it to native executable code, and secure it without going through intermediate languages such as JavaScript, and even to cross back and forth between Java and native code. This allows coders to choose the benefits of multiple languages, such as using one to ensure portability while using others to enhance performance.

"The biggest benefit may be that users can have more peace of mind that a piece of software works as they want it to," says Morrisett. "For users, the impact of such a tool is slightly more tangible; it allows users to safely run, for example, games, in a web browser without the painfully slow speeds that translated code traditionally provides."

Previous efforts to develop a robust, error-free checker have resulted in some success, but RockSalt has the potential to be scaled to software widely used by the general public. The researchers expect that their tool might end up being adopted and integrated into future versions of common web browsers. Morrisett and his team also have plans to adapt the tool for use in a broader variety of processors.

Reflecting on how the class project has been transformative, Tassarotti says, "I plan to pursue a Ph.D. in computer science, and I hope to work on projects like this that can improve the correctness of software. As computers are so prevalent now in fields like avionics and medical devices, I believe that this type of research is essential to ensure safety."

Photonics: Sensing With Holes

The detection of small quantities of molecules is important for a myriad of applications, ranging from gas sensing to biomedical diagnostics. The majority of these applications require the sensors to be cheap and disposable, yet sensitive enough to detect molecules down to the single-molecule level. Ping Bai and co-workers at the A*STAR Institute of High Performance Computing and the Institute of Materials Research and Engineering have now studied the properties of thin metallic films with holes in them that are particularly promising for molecular sensing.

Metallic thin films with nanometer-sized holes in them are known to transmit light of particular wavelengths very efficiently. The efficiency arises from surface plasmon polaritons (SPPs) -- the collective movements of electrons on the metal surface -- which are able to focus light into tiny spots much smaller than the wavelength of light used (see image).

These SPPs can be used to detect the molecules through the fluorescence of tracer molecules attached to them. This fluorescence is also strongly enhanced by the SPP and can easily be detected by a microscope even for small quantities of molecules. "The whole setup is ultra-compact to support a point-of-care sensing system," explains Bai.

Bai and his colleagues studied two sensing arrangements. In the first arrangement, light is directed at a film with nanoholes at an oblique angle from the same side as the sample. In the second arrangement, the film is illuminated from the back so that light is travelling through the holes first. The researchers found that each scheme has its own advantages.

In the 'reflection' scheme, the SPP effect is stronger as the light is directly aimed at the sample and does not have to cross the metal film. However, a thicker film is needed so that the light does not pass through. In the 'transmission' scheme, the intensity of the light emitted by the molecules is weaker, but the advantage there is that filters and other sensors can possibly be included with the metal film, and the film thickness can be much thinner.

"There is therefore no clear advantage for either sensing modes of such films," says Bai. "One thing that is clear from the study, however, is the clear benefits of using metal films with nanoholes as a molecular sensing platform," says Bai.

"This is merely a snapshot of our whole project. Ultimately, our sensing technology will be utilized in hospitals and test centers, for example, in prostate cancer screening, or even used at home just like glucose test kits," adds Bai.

Stone Age Tools Help to Streamline Modern Manufacturing

The analysis of stone tools is a key factor in understanding early human life including social organisation and diet. Archaeologists at the University of Bradford hypothesised that reconstructing past activities was the best way to study what each tool was used for. They proposed to measure the surface structures of replica stone tools before and after they were used in different reconstructions on two natural materials -- antler and wood.

NPL conducted surface measurement investigations on the replica tools using a confocal microscope to create a map of surface structure. Richard Leach, who led the work at NPL, said: "We measured the surfaces of each tool using a confocal microscope to create a map of its surface structure. Optical measurements create 3D constructions of each surface recorded without physically contacting the surface."

The measurements taken by NPL on each tool before, during and after wear experiments revealed variations in the surfaces that can be used to predict the use of the tools. The results offered interesting insight into the breadth of future experiments necessary to provide conclusive results on the use of stone tools in prehistory.

These measurements also formed part of a development process for new instruments being used in a wider NPL project to support all aspects of manufacturing: from turbine blades to grinding machines to mobile phone screens.

NPL has produced a range of equipment which allows the manufacturing world to gain a better understanding of surface topography, without using stylus instruments -- which have proved slow for in-process applications. NPL has worked in conjunction with the International Organization for Standardization (ISO) to develop the use of optical systems to conduct areal surface measurements, including instrumentation, calibration artefacts, good practice guides and reference software.

More accurate surface measurements allow manufacturers to revolutionise designs of existing and developing technologies, for example by controlling how the surfaces glide through air, absorb or repel water, or reflect light.

Richard Leach said: "Greater accuracy and more intelligent use of areal surface measurements impacts outputs such as improved fuel efficiency or the intelligence of touch screens. Using new ways to conduct surface measurements provides the opportunity for businesses to meet consumer demand for better quality and more streamlined products."

June Global Temperatures Fourth Highest On Record

Most areas of the world experienced much above-average monthly temperatures, including most of North America and Eurasia, and northern Africa. Only Australia, northern and western Europe, and the northwestern United States were notably cooler than average. Austria recorded its highest ever June temperature of 99.9°F on June 30 in two locations -- the capital city of Vienna and in German-Altenburg, Nope. The monthly temperature during June in the United Kingdom was 0.5°F below the 1971-2000 average, making this the coolest June since 1991. Australia also remained cooler than average due to the lingering effects of La Niña.

For the ocean, the June global sea surface temperature was 0.85°F above the 20th century average of 61.5°F, the 10th warmest June on record. Neutral ocean conditions continued across the equatorial Pacific Ocean during June as sea surface temperatures continued to warm. According to NOAA's Climate Prediction Center, there is an increased chance that El Niño conditions will emerge beginning in July-September 2012. In addition to influencing seasonal climate outcomes in the United States, El Niño is often, but not always, associated with global temperatures that are higher than temperatures in the neutral and La Niña phases.

Dairy Researchers Identify Bacterial Spoilers in Milk

Milk undergoes heat treatment -- pasteurization -- to kill off microbes that can cause food spoilage and disease, but certain bacterial strains can survive this heat shock as spores and cause milk to curdle in storage.

Researchers in the Milk Quality Improvement Program at Cornell's College of Agriculture and Life Sciences have identified the predominant spore-forming bacteria in milk and their unique enzyme activity, knowledge that can now be used to protect the quality and shelf life of dairy products.

"Control of food spoilage is critical in a world that needs to feed 7 billion people," said Martin Wiedmann, food science professor and study co-author. "Approximately 25 percent of post-harvest food is spoiled by microbes before it is consumed."

The study, published in the March issue of Applied Environmental Microbiology by the lab of Wiedmann and Kathryn Boor, the Ronald P. Lynch Dean of the College of Agriculture and Life Sciences, identified the predominant strains of spore-forming bacteria, which can foul milk and other food products. The culprits, Paenibacillus bacteria, are ubiquitous in nature and cause off-flavors in a variety of foods and curdling in dairy products.

As spores, the bacteria can survive in dormant form for years despite the best practices in cleaning, processing and packaging.

In fact, the bacteria may be uniquely adapted to overcome the twin tactics of dairy protection: pasteurization followed by refrigeration. According to co-author and research support specialist Nicole Martin, the spores are not only resistant to heat, the small jolt of heat during pasteurization may actually stimulate them to germinate. Some can reproduce in refrigerated dairy products at temperatures that would stymy other types of bacteria.

"We studied 1,288 bacterial isolates in raw milk, pasteurized milk and the dairy farm environment; however, only a handful of strains accounted for 80 percent of the spore-formers present," said Wiedmann. "They grow well in milk -- and possibly other foods -- at temperatures as low as 43 F, and we can identify Paenibacillus because of their uniquely high galactosidase enzyme activity at 32 C."

They also investigated how pasteurization affects the presence of such bacteria.

Concerns about food safety have prompted many dairy processors to increase pasteurization temperatures above the 161 F minimum set by the government. Anecdotal reports, however, suggested this practice actually led to more spoilage once the products were refrigerated.

Tallying bacterial numbers throughout the refrigerated shelf life of milk pasteurized at two different temperatures -- 169 F and 175 F -- the Wiedmann-Boor lab found that lowering the temperature significantly reduced bacterial growth during refrigerated storage, especially by 21 days after pasteurization.

The findings are already being applied in the field. The Wiedmann-Boor Lab was enlisted by Upstate Niagara, a cooperative of more than 360 dairy farm families throughout western New York, to further improve the quality of their award-winning milk by assessing milk samples for spore-formers.

Data on samples that contained spore-forming bacteria are now being analyzed using DNA fingerprinting to identify the types of organisms present and where they might have come from.

Martin said she hopes the collaborative project will become a model for how to approach spore-forming bacteria in individual dairy processing plants.

"It's one of the strengths we have at Cornell -- we are able to do advanced research and immediately turn it around to help the industry," Martin said.

Fifty Metric Tons of Marine Debris from Northwestern Hawaiian Islands

"What surprises us is that after many years of marine debris removal in Papahānaumokuākea and more than 700 metric tons of debris later, we are still collecting a significant amount of derelict fishing gear from the shallow coral reefs and shorelines," said Kyle Koyanagi, marine debris operations manager at NOAA Fisheries' Pacific Islands Fisheries Science Center and chief scientist for the mission. "The ship was at maximum capacity and we did not have any space for more debris."

Scientists load boats with marine debris collected at Midway Atoll in Papahānaumokuākea Marine National Monument. High resolution (Credit: NOAA) This year, marine debris was collected from waters and shorelines around northern most islands and atolls: Kure Atoll, Midway Atoll, Pearl and Hermes Atoll, Lisianski Island and Laysan Island. Approximately half of the debris was composed of derelict fishing gear and plastics from Midway Atoll's shallow coral reef environments, where the team also completed a 27-day land-based mission prior to loading debris on the 224-ft. NOAA Ship Oscar Elton Sette.

As part of this year's mission, the NOAA team did look for debris from the 2011 tsunami in Japan, however, no debris with an explicit connection to the tsunami was found. Scientists monitored marine debris for radiation in partnership with the Hawaii Department of Health out of abundance of caution and to gather baseline data from the NWHI.

"While we did not find debris with an obvious connection to last year's tsunami, this mission was a great opportunity to leverage activities that had already been planned and see what we might find," said Carey Morishige, Pacific Islands regional coordinator for NOAA's Marine Debris Program. "It's also an important reminder that marine debris is an everyday problem, especially here in the Pacific."

NOAA divers cut a Hawaiian green sea turtle free from a derelict fishing net during a recent mission to collect marine debris in the Northwestern Hawaiian Islands. High resolution (Credit: NOAA) A portion of the funding for this year's marine debris removal activities was provided as part of the legal settlement collected by NOAA's Damage Assessment, Remediation and Restoration Program from a July 2005 ship grounding at Pearl and Hermes Atoll in the Monument. Additional support was provided by NOAA's Marine Debris Program, NOAA Fisheries' Pacific Islands Fisheries Science Center and Papahānaumokuākea Marine National Monument, as well as other partners including U.S. Fish and Wildlife Service, the State of Hawaii, U.S. Coast Guard, Schnitzer Steel, and Covanta Energy.

Marine debris removed during this project will be used to create electricity through Hawaii's Nets to Energy Program, a public-private partnership. Since 2002, more than 730 metric tons of derelict nets have been used to create electricity -- enough to power nearly 350 Hawai'i homes for a year.

Dominant Deer Hinds Choose the Best Food

Deer hinds (Cervus elaphus) have a hierarchical organisation system: the oldest and largest hold the most dominant positions. Therefore, a nutrient rich diet benefits the more dominant hinds, who have preferential access to the best food sources. This allows them to grow even bigger, improving their milk production and body condition.

Published in the PLoS One journal and headed by the University of Castilla-La Mancha (UCLM), the study demonstrates how even when food is in abundance, the dominant hinds select the best foods.

Carried out in 2009 on the Albacete experimental deer farm, the second most important in the world (after the one in New Zealand), the experiment lasted seven days. It involved observing the behaviour of 44 deer hinds when accessing food during the first hour, their selection of food components and their nutritional composition. 

The results reveal that the “dominant hinds used more time to feed during the first hour after the food was put out, they selected cereals and rejected food pellets (nutritiously low vegetable by-products),” as explained to SINC by Francisco Ceacero, lead author of the study and researcher at the department of Science and Agro-Forest and Genetics Technologies of the UCLM.

The hinds chose the food according to energy and fat content. According to Ceacero, “food quality gets lower and lower the further away we move from the time in which the food is put out. In this way, the dominant hinds receive more energy in their diet whereas their subordinates do still get to eat enough but only the poor quality food that is left behind.”

The same goes for cows and sheep

Although the discussion continues on the mechanisms that drive these animals to know how to select the best food that meets their requirements every time, the scientist ensures that “the preferential selection of certain foods and the total rejection of others is clear in both diet selection studies on wild animal populations and experiments in captivity.”

The experiment combined behavioural study techniques (hierarchy and food access observation), ecological study techniques (diet component selection) and nutrition study techniques (nutritional value of each food item and the dietary intake itself).

The team of authors, which also included Tomás Landete-Castillejos and Andrés José García from the Research Institute of Hunting Resources, suggests that the results are also applicable to other social ruminants like cows, sheep and goats.

Largest Ancient Dam Built by Maya in Central America

That dam -- constructed from cut stone, rubble and earth -- stretched more than 260 feet in length, stood about 33 feet high and held about 20 million gallons of water in a human-made reservoir.

These findings on ancient Maya water and land-use systems at Tikal, located in northern Guatemala, are scheduled to appear this week in the Proceedings of the National Academy of Sciences (PNAS) in an article titled "Water and Sustainable Land Use at the Ancient Tropical City of Tikal, Guatemala." The research sheds new light on how the Maya conserved and used their natural resources to support a populous, highly complex society for over 1,500 years despite environmental challenges, including periodic drought.

The paper is authored by Vernon Scarborough, UC professor of anthropology; Nicholas Dunning, UC professor of geography; archaeologist Kenneth Tankersley, UC assistant professor of anthropology; Christopher Carr, UC doctoral student in geography; Eric Weaver, UC doctoral student in geography; Liwy Grazioso of the Universidad de San Carlos de Guatemala; Brian Lane, former UC master's student in anthropology now pursuing doctoral studies at the University of Hawaii; John Jones, associate professor of anthropology, Washington State University; Palma Buttles, technical staff senior member, SEI Carnegie Mellon University; Fred Valdez, professor of anthropology, University of Texas-Austin; and David Lentz, UC professor of biology.

Starting in 2009, the UC team was the first North American group permitted to work at the Tikal site core in more than 40 years.

Detailed in the latest findings by the UC-led efforts are

• The largest ancient dam built by the ancient Maya of Central America

• Discussion on how reservoir waters were likely released

• Details on the construction of a cofferdam needed by the Maya to dredge one of the largest reservoirs at Tikal

• The presence of ancient springs linked to the initial colonization of Tikal

• Use of sand filtration to cleanse water entering reservoirs

• A "switching station" that accommodated seasonal filling and release of water

• Finding of the deepest, rock-cut canal segment in the Maya lowlands

An example of the thick vegetation common in the area where a UC-led team worked in and around Tikal.

According to UC's Scarborough, "The overall goal of the UC research is to better understand how the ancient Maya supported a population at Tikal of perhaps 60,000 to 80,000 inhabitants and an estimated population of five million in the overall Maya lowlands by AD 700."

He added, "That is a much higher number than is supported by the current environment. So, they managed to sustain a populous, highly complex society for well over 1,500 years in a tropical ecology. Their resource needs were great, but they used only stone-age tools and technology to develop a sophisticated, long-lasting management system in order to thrive."

Water collection and storage were critical in the environment where rainfall is seasonal and extended droughts not uncommon. And so, the Maya carefully integrated the built environment -- expansive plazas, roadways, buildings and canals -- into a water-collection and management system. At Tikal, they collected literally all the water that fell onto these paved and/or plastered surfaces and sluiced it into man-made reservoirs. For instance, the city's plastered plaza and courtyard surfaces and canals were canted in order to direct and retain rainwater runoff into these tanks.

In fact, by the Classic Period (AD 250-800), the dam (called the Palace Dam) identified by the UC-led team was constructed to contain the waters that were now directed from the many sealed plaster surfaces in the central precinct. It was this dam on which the team focused its latest work, completed in 2010. This gravity dam presents the largest hydraulic architectural feature known in the Maya area. In terms of greater Mesoamerica, it is second in size only to the huge Purron Dam built in Mexico's Tehuacan Valley sometime between AD 250-400.

Said Scarborough, "We also termed the Palace Dam at Tikal the Causeway Dam, as the top of the structure served as a roadway linking one part of the city to another. For a long time, it was considered primarily a causeway, one that tourists coming to the site still use today. However, our research now shows that it did double duty and was used as an important reservoir dam as well as a causeway."

Another discovery by the UC-led team: To help purify water as it sluiced into the reservoir tanks via catchment runoff and canals, the Maya employed deliberately positioned "sand boxes" that served to filter the water as it entered into the reservoirs. "These filtration beds consisted of quartz sand, which is not naturally found in the greater Tikal area. The Maya of Tikal traveled at least 20 miles (about 30 kilometers) to obtain the quartz sand to create their water filters. It was a fairly laborious transportation effort. That speaks to the value they placed on water and water management," said UC's Nicholas Dunning.

According to UC's Ken Tankersley, "It's likely that the overall system of reservoirs and early water-diversion features, which were highly adaptable and resilient over a long stretch, helped Tikal and some other centers survive periodic droughts when many other settlement sites had to be abandoned due to lack of rainfall."

UC paleoethnobotanist David Lentz explained that the sophisticated water management practiced by the ancient Maya impacted the availability of food, fuel, medicinal plants and other necessities. He said, "Water management by the Maya included irrigation, which directly impacted how many people could be fed and overall population growth. Accordingly, it is essential to understand the array of canals and reservoirs at Tikal, which conserved water during the annual dry season and controlled floodwaters during the rainy months. These practices allowed the Tikal Maya to sustain relatively high population densities for several centuries. As it evolved, this system of reservoirs was largely dependent on rainfall for recharging. With the onset of the 9th century droughts however, water supplies dwindled, causing the resource base and social fabric of the Tikal Maya to come under considerable stress. These developments may well have contributed to the abandonment of the city."

Of significance to Scarborough and the entire team are the potential lessons that can be gleaned from identifying a water system like that at ancient Tikal. Said Scarborough, "Water management in the ancient context can be dismissed as less relevant to our current water crisis because of its lack of technological sophistication. Nevertheless, in many areas of the world today, the energy requirements for even simple pumping and filtering devices -- to say nothing about replacement-part acquisition -- challenges access to potable sources. Tropical settings can be especially difficult regions because of high infectious disease loads borne by unfiltered water schemes. The ancient Maya, however, developed a clever rainwater catchment and delivery system based on elevated, seasonally charged reservoirs positioned in immediate proximity to the grand pavements and pyramidal architecture of their urban cores. Allocation and potability were developmental concerns from the outset of colonization. Perhaps the past can fundamentally inform the present, if we, too, can be clever."

UC's research at Tikal is supported by the Alphawood Foundation, by the National Science Foundation and by the university.

Colorful Science Sheds Light On Solar Heating

More information, of course, requires more complex visualizations and occasionally such images are not just informative, but beautiful too.

Such is the case with a new technique created by Nicholeen Viall, a solar scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. She creates images of the sun reminiscent of Van Gogh, with broad strokes of bright color splashed across a yellow background. But it's science, not art. The color of each pixel contains a wealth of information about the 12-hour history of cooling and heating at that particular spot on the sun. That heat history holds clues to the mechanisms that drive the temperature and movements of the sun's atmosphere, or corona.

"We don't understand why the corona is so hot," says Viall who wrote about this technique and her conclusions about the corona in a paper that recently appeared in The Astrophysical Journal. "The corona is 1,000 times hotter than the sun's surface, when we would expect it to get cooler as the atmosphere gets further away from the hot sun, the same way the air gets cooler further away from a fire."

Scientists generally agree that energy in the roiling magnetic fields of the sun must transfer energy and heat up into the atmosphere, but the exact details of that process are still debated. Viall created her technique to see if she could distinguish between theories that describe coronal heating as uniform over time, versus those that say it comes from numerous nanoflares on the sun's surface.

To look at the corona from a fresh perspective, Viall created a new kind of picture, making use of the high resolution provided by NASA's Solar Dynamics Observatory (SDO). SDO's Atmospheric Imaging Assembly (AIA) provides images of the sun in 10 different wavelengths, each approximately corresponding to a single temperature of material. Therefore, when one looks at the wavelength of 171 Angstroms, for example, one sees all the material in the sun's atmosphere that is a million degrees Kelvin. By looking at an area of the sun in different wavelengths, one can get a sense of how different swaths of material change temperature. If an area seems bright in a wavelength at shows a hotter temperature an hour before it becomes bright in a wavelength that shows a cooler temperature, one can gather information about how that region has changed over time.

To study such temperature changes, many scientists focus on analyzing a specific subset of solar material, such as giant arcs of charged particles that leap up off the sun's surface called coronal loops. Scientists gather information about the loops by comparing nearly simultaneous images of the sun in different wavelengths. Analysis of the loops in each image requires time-consuming, manual analysis to subtract the background observations away from the loops themselves, a process which is also inherently subject to human judgment and bias. In addition, each individual image represents light from only a narrow range of wavelengths, representing material at a narrow range of temperatures.

Viall wanted to look at as much of the solar material in a given area of the corona as she could, incorporating information about a variety of temperatures simultaneously. She also wanted to avoid the subjective process of subtracting out the background. Instead, she decided to look at all light coming from a given spot on the sun at the same time. That meant coming up with a visualization technique to convey all that information at once -- and thus her Van Gogh-like images were born.

For an interesting spot on the sun, Viall examines six channels over an entire 12-hour stretch. She compares each channel to the other channels in turn, assigning it a red, orange, or yellow color if the area has cooled, and assigning it a blue or green color if the area has heated up. She assigns the exact shade of the color based on how much time it took for the temperature change to occur.

"In essence, I'm measuring the time lag of how long it takes a given area to heat up or cool down," says Viall. "But it's totally automated, with no need for humans to make a decision about what to incorporate or ignore. And all of the solar material is represented statistically, not just one wavelength of light."

Viall's images show a wealth of reds, oranges, and yellow, meaning that over a 12-hour period the material appear to be cooling. Obviously there must have been heating in the process as well, since the corona isn't on a one-way temperature slide down to zero degrees. Any kind of steady heating throughout the corona would have shown up in Viall's images, so she concludes that the heating must be quick and impulsive -- so fast that it doesn't show up in her images. This lends credence to those theories that say numerous nanobursts of energy help heat the corona.

Scientists Read Monkeys' Inner Thoughts: Brain Activity Decoded While Monkeys Avoid Obstacle to Touch Target

Anyone who has looked at the jagged recording of the electrical activity of a single neuron in the brain must have wondered how any useful information could be extracted from such a frazzled signal.

But over the past 30 years, researchers have discovered that clear information can be obtained by decoding the activity of large populations of neurons.

Now, scientists at Washington University in St. Louis, who were decoding brain activity while monkeys reached around an obstacle to touch a target, have come up with two remarkable results.

Their first result was one they had designed their experiment to achieve: they demonstrated that multiple parameters can be embedded in the firing rate of a single neuron and that certain types of parameters are encoded only if they are needed to solve the task at hand.

Their second result, however, was a complete surprise. They discovered that the population vectors could reveal different planning strategies, allowing the scientists, in effect, to read the monkeys' minds.

By chance, the two monkeys chosen for the study had completely different cognitive styles. One, the scientists said, was a hyperactive type, who kept jumping the gun, and the other was a smooth operator, who waited for the entire setup to be revealed before planning his next move. The difference is clearly visible in their decoded brain activity.

The study was published in the July 19th advance online edition of the journal Science.

All in the task

The standard task for studying voluntary motor control is the "center-out task," in which a monkey or other subject must move its hand from a central location to targets placed on a circle surrounding the starting position.

To plan the movement, says Daniel Moran, PhD, associate professor of biomedical engineering in the School of Engineering & Applied Science and of neurobiology in the School of Medicine at Washington University in St. Louis, the monkey needs three pieces of information: current hand and target position and the velocity vector that the hand will follow.

In other words, the monkey needs to know where his hand is, what direction it is headed and where he eventually wants it to go.

A variation of the center-out task with multiple starting positions allows the neural coding for position to be separated from the neural coding for velocity.

By themselves, however, the straight-path, unimpeded reaches in this task don't let the neural coding for velocity to be distinguished from the neural coding for target position, because these two parameters are always correlated. The initial velocity of the hand and the target are always in the same direction.

To solve this problem and isolate target position from movement direction, doctoral student Thomas Pearce designed a novel obstacle-avoidance task to be done in addition to the center-out task.

Crucially, in one-third of the obstacle-avoidance trials, either no obstacle appeared or the obstacle didn't block the monkey's path. In either case, the monkey could move directly to the target once he got the "go" cue.

The population vector corresponding to target position showed up during the third hold of the novel task, but only if there was an obstacle. If an obstacle appeared and the monkey had to move its hand in a curved trajectory to reach the target, the population vector lengthened and pointed at the target. If no obstacle appeared and the monkey could move directly to the target, the population vector was insignificant.

In other words, the monkeys were encoding the position of the target only when it did not lie along a direct path from the starting position and they had to keep its position "in mind" as they initially moved in the "wrong" direction.

"It's all," Moran says, "in the design of the task."

And then some magic happens

Pearce's initial approach to analyzing the data from the experiment was the standard one of combining the data from the two monkeys to get a cleaner picture.

"It wasn't working," Pearce says, "and I was frustrated because I couldn't figure out why the data looked so inconsistent. So I separated the data by monkey, and then I could see, wow, they're very different. They're approaching this task differently and that's kind of cool."

The difference between the monkey's' styles showed up during the second hold. At this point in the task, the target was visible, but the obstacle had not yet appeared.

The hyperactive monkey, called monkey H, couldn't wait. His population vector during that hold showed that he was poised for a direct reach to the target. When the obstacle was then revealed, the population vector shortened and rotated to the direction he would need to move to avoid the obstacle.

The smooth operator, monkey G, in the meantime, idled through the second hold, waiting patiently for the obstacle to appear. Only when it was revealed did he begin to plan the direction he would move to avoid the obstacle.

Because he didn't have to correct course, monkey G's strategy was faster, so what advantage was it to monkey H to jump the gun? In the minority of trials where no obstacle appeared, monkey H approached the target more accurately than monkey G. Maybe monkey H is just cognitively adapted to a Whac-A-Mole world. And monkey G, when caught without a plan, was at a disadvantage.

Working with the monkeys, the scientists had been aware that they had very different personalities, but they had no idea this difference would show up in their neural recordings.

"That's what makes this really interesting," Moran says.

'Caffeinated' Coastal Waters: Possible Sources Include Sewer Overflows, Septic Tanks

This study is the first to look at caffeine pollution off the Oregon coast. It was developed and conducted by Portland State University master's student Zoe Rodriguez del Rey and her faculty adviser Elise Granek, assistant professor of Environmental Science and Management, in collaboration with Steve Sylvester of Washington State University, Vancouver.

In spring 2010, Rodriguez del Rey and Granek collected and analyzed samples from 14 coastal locations and seven adjacent water bodies as far north as Astoria, Ore., and as far south as Brookings.

Locations were identified as potentially polluted if they were near wastewater treatment plants, large population centers or rivers and streams emptying into the ocean.

The study found high caffeine levels near Carl Washburne State Park (Florence, Ore.) and Cape Lookout, two areas not near the potential pollution sources, yet low levels of caffeine near large population centers like Astoria/Warrenton and Coos Bay.

High levels were also found following a late-season storm of wind and rain that triggered sewer overflows.

Results of the study were published in the July 2012 Marine Pollution Bulletin, "Occurrence and concentration of caffeine in Oregon coastal waters."

The results seem to indicate that wastewater treatment plants are effective at removing caffeine, but that high rainfall and combined sewer overflows flush the contaminants out to sea. The results also suggest that septic tanks, such as those used at the state parks, may be less effective at containing pollution.

"Our study findings indicate that, contrary to our prediction, the waste water treatment plants are not a major source of caffeine to coastal waters," says Granek. "However, onsite waste disposal systems may be a big contributor of contaminants to Oregon's coastal ocean and need to be better studied to fully understand their contribution to pollution of ocean waters."

Caffeine is found in many food and beverage products as well as some pharmaceuticals, and caffeine pollution is directly related to human activity (although many plant species produce caffeine, there are no natural sources of the substance in the Northwest). The presence of caffeine may also signal additional anthropogenic pollution, such as pesticides, pharmaceuticals and other contaminants.

Even "elevated levels" of caffeine are measured in nanograms per liter, well below a lethal dose for marine life. However, an earlier study by Rodriguez del Rey and Granek on intertidal mussels showed that caffeine at the levels measured in this current study can still have an effect despite the lower doses

"We humans drink caffeinated beverages because caffeine has a biological effect on us -- so it isn't too surprising that caffeine affects other animals, too," says Granek. Previous studies have found caffeine in other bodies of water around the world, including the North Sea, the Mediterranean, Puget Sound, Boston Harbor, and Sarasota Bay, Fla.

Global CO2 Emissions Continued to Increase in 2011, With Per Capita Emissions in China Reaching European Levels

Global emissions of carbon dioxide (CO₂) -- the main cause of global warming -- increased by 3% last year, reaching an all-time high of 34 billion tonnes in 2011. In China, the world's most populous country, average emissions of CO₂ increased by 9% to 7.2 tonnes per capita. China is now within the range of 6 to 19 tonnes per capita emissions of the major industrialised countries. In the European Union, CO₂ emissions dropped by 3% to 7.5 tonnes per capita. The United States remains one of the largest emitters of CO₂, with 17.3 tones per capita, despite a decline due to the recession in 2008-2009, high oil prices and an increased share of natural gas.These are the main findings of the annual report 'Trends in global CO₂ emissions', released July 19 by the European Commission's Joint Research Centre (JRC) and the Netherlands Environmental Assessment Agency (PBL).

Based on recent results from the Emissions Database for Global Atmospheric Research (EDGAR) and latest statistics on energy use and relevant activities such as gas flaring and cement production, the report shows that global CO₂ emissions continued to grow in 2011, despite reductions in OECD countries. Weak economic conditions, a mild winter, and energy savings stimulated by high oil prices led to a decrease of 3% in CO₂ emissions in the European Union and of 2% in both the United States and Japan. Emissions from OECD countries now account for only one third of global CO₂ emissions -- the same share as that of China and India combined, where emissions increased by 9% and 6% respectively in 2011. Economic growth in China led to significant increases in fossil fuel consumption driven by construction and infrastructure expansion. The growth in cement and steel production caused China's domestic coal consumption to increase by 9.7%.

The 3% increase in global CO₂ emissions in 2011 is above the past decade's average annual increase of 2.7%, with a decrease in 2008 and a surge of 5% in 2010. The top emitters contributing to the 34 billion tonnes of CO₂ emitted globally in 2011 are: China (29%), the United States (16%), the European Union (11%), India (6%), the Russian Federation (5%) and Japan (4%).

Cumulative CO₂ emissions call for action

An estimated cumulative global total of 420 billion tonnes of CO₂ were emitted between 2000 and 2011 due to human activities, including deforestation. Scientific literature suggests that limiting the rise in average global temperature to 2°C above pre-industrial levels -- the target internationally adopted in UN climate negotiations -- is possible only if cumulative CO₂ emissions in the period 2000-2050 do not exceed 1 000 to 1 500 billion tonnes. If the current global trend of increasing CO₂ emissions continues, cumulative emissions will surpass this limit within the next two decades.

Fortunately, this trend is being mitigated by the expansion of renewable energy supplies, especially solar and wind energy and biofuels. The global share of these so-called modern renewables, which exclude hydropower, is growing at an accelerated speed and quadrupled from 1992 to 2011. This potentially represents about 0.8 billion tonnes of CO₂ emissions avoided as a result of using renewable energy supplies in 2011, which is cloin 2011.se to Germany's total CO₂ emissions

IS REALLY THE WORLD END ?

The end of the world is near—December 21, 2012, to be exact—according to theories based on a purported ancient Maya prediction and fanned by the marketing machine behind the soon-to-be-released 2012 movie.

But could humankind really meet its end in 2012—drowned in apocalyptic floods, walloped by a secret planet, seared by an angry sun, or thrown overboard by speeding continents?

And did the ancient Maya—whose empire peaked between A.D. 250 and 900 in what is now Mexico and Central America—really predict the end of the world in 2012?

At least one aspect of the 2012, end-of-the-world hype is, for some people, all too real: the fear.

NASA's Ask an Astrobiologist Web site, for example, has received thousands of questions regarding the 2012 doomsday predictions—some of them disturbing, according to David Morrison, senior scientist with the NASA Astrobiology Institute.

"A lot of [the submitters] are people who are genuinely frightened," Morrison said.

"I've had two teenagers who were considering killing themselves, because they didn't want to be around when the world ends," he said. "Two women in the last two weeks said they were contemplating killing their children and themselves so they wouldn't have to suffer through the end of the world."

(Related gallery: "Apocalypse Pictures—Ten Failed Doomsday Prophecies.")

Fortunately, with the help of scientists like Morrison, most of the predicted 2012 cataclysms are easily explained away.

2012 MYTH 1

Maya Predicted End of the World in 2012

The Maya calendar doesn't end in 2012, as some have said, and the ancients never viewed that year as the time of the end of the world, archaeologists say.

But December 21, 2012, (give or take a day) was nonetheless momentous to the Maya.

"It's the time when the largest grand cycle in the Mayan calendar—1,872,000 days or 5,125.37 years—overturns and a new cycle begins," said Anthony Aveni, a Maya expert and archaeoastronomer at Colgate University in Hamilton, New York.

The Maya kept time on a scale few other cultures have considered.

During the empire's heyday, the Maya invented the Long Count—a lengthy circular calendar that "transplanted the roots of Maya culture all the way back to creation itself," Aveni said.

During the 2012 winter solstice, time runs out on the current era of the Long Count calendar, which began at what the Maya saw as the dawn of the last creation period: August 11, 3114 B.C. The Maya wrote that date, which preceded their civilization by thousands of years, as Day Zero, or 13.0.0.0.0.

In December 2012 the lengthy era ends and the complicated, cyclical calendar will roll over again to Day Zero, beginning another enormous cycle.

"The idea is that time gets renewed, that the world gets renewed all over again—often after a period of stress—the same way we renew time on New Year's Day or even on Monday morning," said Aveni, author of The End of Time: The Maya Mystery of 2012.

2012 MYTH 2

Breakaway Continents Will Destroy Civilization

In some 2012 doomsday prophecies, the Earth becomes a deathtrap as it undergoes a "pole shift."

The planet's crust and mantle will suddenly shift, spinning around Earth's liquid-iron outer core like an orange's peel spinning around its fleshy fruit. (See what Einstein had to say about pole shifts.)

2012, the movie, envisions a Maya-predicted pole shift, triggered by an extreme gravitational pull on the planet—courtesy of a rare "galactic alignment"—and by massive solar radiation destabilizing the inner Earth by heating it.

Breakaway oceans and continents dump cities into the sea, thrust palm trees to the poles, and spawn earthquakes, tsunamis, volcanic eruptions, and other disasters. (Interactive: pole shift theories illustrated.)

Scientists dismiss such drastic scenarios, but some researchers have speculated that a subtler shift could occur—for example, if the distribution of mass on or inside the planet changed radically, due to, say, the melting of ice caps.

Princeton University geologist Adam Maloof has extensively studied pole shifts, and tackles this 2012 myth in 2012: Countdown to Armageddon, a National Geographic Channel documentary airing Sunday, November 8. (The National Geographic Society owns National Geographic News and part-owns the National Geographic Channel.)

Maloof says magnetic evidence in rocks confirm that continents have undergone such drastic rearrangement, but the process took millions of years—slow enough that humanity wouldn't have felt the motion (quick guide to plate tectonics).

2012 MYTH 3

Galactic Alignment Spells Doom

Some sky-watchers believe 2012 will close with a "galactic alignment," which will occur for the first time in 26,000 years (for example, see the Web site Alignment 2012).

In this scenario, the path of the sun in the sky would appear to cross through what, from Earth, looks to be the midpoint of our galaxy, the Milky Way, which in good viewing conditions appears as a cloudy stripe across the night sky.

Some fear that the lineup will somehow expose Earth to powerful unknown galactic forces that will hasten its doom—perhaps through a "pole shift" (see above) or the stirring of the supermassive black hole at our galaxy's heart.

Others see the purported event in a positive light, as heralding the dawn of a new era in human consciousness.

NASA's Morrison has a different view.

"There is no 'galactic alignment' in 2012," he said, "or at least nothing out of the ordinary."

He explained that a type of "alignment" occurs during every winter solstice, when the sun, as seen from Earth, appears in the sky near what looks to be the midpoint of the Milky Way.

Horoscope writers may be excited by alignments, Morrison said. But "the reality is that alignments are of no interest to science. They mean nothing," he said. They create no changes in gravitational pull, solar radiation, planetary orbits, or anything else that would impact life on Earth.

The speculation over alignments isn't surprising, though, he said.

"Ordinary astronomical phenomena are imbued with a sense of threat by people who already think the world is going to end."

Regarding galactic alignments, University of Texas Maya expert David Stuart writes on his blog that "no ancient Maya text or artwork makes reference to anything of the kind."

Even so, the end date of the current Long Count cycle—winter solstice 2012—may be evidence of Maya astronomical skill, said Aveni, the archaeoastronomer.

"I don't rule out the likelihood that astronomy played a role" in the selection of 2012 as the cycle's terminus, he said.

Maya astronomers built observatories and, by observing the night skies and using mathematics, learned to accurately predict eclipses and other celestial phenomena. Aveni notes that the start date of the current cycle was likely tied to a solar zenith passage, when the sun crosses directly overhead, and its terminal date will fall on a December solstice, perhaps by design.

(Take a Maya Empire quiz.)

These choices, he said, may indicate that the Maya calendar is tied to seasonal agricultural cycles central to ancient survival.

2012 MYTH 4

Planet X Is on a Collision Course With Earth

Some say it's out there: a mysterious Planet X, aka Nibiru, on a collision course with Earth—or at least a disruptive flyby.

A direct hit would obliterate Earth, it's said. Even a near miss, some fear, could shower Earth with deadly asteroid impacts hurled our way by the planet's gravitational wake.

Could such an unknown planet really be headed our way in 2012, even just a little bit?

Well, no.

"There is no object out there," NASA astrobiologist Morrison said. "That's probably the most straightforward thing to say."

The origins of this theory actually predate widespread interest in 2012. Popularized in part by a woman who claims to receive messages from extraterrestrials, the Nibiru doomsday was originally predicted for 2003.

"If there were a planet or a brown dwarf or whatever that was going to be in the inner solar system three years from now, astronomers would have been studying it for the past decade and it would be visible to the naked eye by now," Morrison said.

"It's not there."

2012 MYTH 5

Solar Storms to Savage Earth

In some 2012 disaster scenarios, our own sun is the enemy.

Our friendly neighborhood star, it's rumored, will produce lethal eruptions of solar flares, turning up the heat on Earthlings.

Solar activity waxes and wanes according to approximately 11-year cycles. Big flares can indeed damage communications and other Earthly systems, but scientists have no indications the sun, at least in the short term, will unleash storms strong enough to fry the planet.

"As it turns out the sun isn't on schedule anyway," NASA astronomer Morrison said. "We expect that this cycle probably won't peak in 2012 but a year or two later

2012 MYTH 6

Maya Had Clear Predictions for 2012

If the Maya didn't expect the end of time in 2012, what exactly did they predict for that year?

Many scholars who've pored over the scattered evidence on Maya monuments say the empire didn't leave a clear record predicting that anything specific would happen in 2012.

The Maya did pass down a graphic—though undated—end-of-the-world scenario, described on the final page of a circa-1100 text known as the Dresden Codex. The document describes a world destroyed by flood, a scenario imagined in many cultures and probably experienced, on a less apocalyptic scale, by ancient peoples

Aveni, the archaeoastronomer, said the scenario is not meant to be read literally—but as a lesson about human behavior.

He likens the cycles to our own New Year period, when the closing of an era is accompanied by frenetic activities and stress, followed by a rebirth period, when many people take stock and resolve to begin living better.

In fact, Aveni says, the Maya weren't much for predictions.

"The whole timekeeping scale is very past directed, not future directed," he said. "What you read on these monuments of the Long Count are events that connected Maya rulers with ancestors and the divine.

"The farther back you can plant your roots in deep time the better argument you can make that you're legit," Aveni said. "And I think that's why these Maya rulers were using Long Count time.

"It's not about a fixed prediction about what's going to happen."

A Brainwave-Controlled Version of "Pong"

Mind Games Ollie Bland

Few video games are more basic than Pong, but Charles Moyes and Mengxiang Jiang’s version is incredibly complex. The two Cornell University students built a custom electroencephalography (EEG) device so they could control the game’s onscreen paddle with their minds.

The alpha waves that EEG machines read are faint electrical signals; Moyes and Jiang ran the EEG readings through an amplification circuit to filter and boost the signals. The amplified readings are then digitized and sent over USB to a computer running the game.

Spiking alpha waves produced during relaxation move a player’s paddle up, and smaller waves, indicating concentration, move it down. The size of the waves determines how much the paddle moves.

உடற்பயிற்சியின்மையால் மரணங்கள்

'சோம்பியிருத்தல் மரணத்தை விளைவிக்கும் '

புகை பிடித்தல், உடல் பருமன் போன்றவை காரணமாக ஏற்படும் மரணங்களுக்க்கு சமாந்திரமாக, உடற்பயிற்சிக் குறைவும் உலகெங்கும் மக்களைக் கொல்கிறது என்று புதிய மருத்துவ ஆராய்ச்சியொன்று கண்டறிந்திருக்கிறது.

மருத்துவ சஞ்சிகையான "தெ லான்செட்"டில் வெளியான இந்த ஆய்வு, மக்கள் வாரத்திற்குக் குறைந்தது இரண்டரை மணி நேரமாவது, நடப்பது, சைக்கிள் ஓட்டுவது, தோட்டவேலை செய்வது போன்ற மிதமான உடற்பயிற்சிகளை செய்தால், 50 லட்சத்துக்கும் மேலானோர் இறப்பதைத் தவிர்க்கலாம் என்று கூறுகிறது.

இதய நோய், சர்க்கரை வியாதி, சில ரக கான்சர் வியாதிகள் ஏற்படுவது ஆறிலிருந்து பத்து சதவீதமாகக் குறையும் என்றும் அந்த ஆய்வு கூறுகிறது.

இந்த உடற்பயிற்சியின்மை என்ற பிரச்சினை, குறிப்பாக பிரிட்டனில் மிகவும் மோசமாகக் காணப்படுவதாகக் கூறும் இந்த ஆராய்ச்சியாளர்கள், பிரிட்டனில், மூன்றில் இரண்டு வயது வந்தோர், பரிந்துரைக்கப்பட்ட உடற்பயிற்சியை செய்யத் தவறுகிறார்கள் என்று கூறுகின்றனர்.

இயற்கை பாதுகாப்பில் எலி இனங்களின் முக்கிய பங்களிப்பு

மிகப்பெரிய மரங்கள் முதல் சின்னஞ்சிறு செடிகொடிகள் வரை பல்வேறு வகையான தாவர விதைகளை பார தூரமாக கொண்டு சென்று சம்பந்தப்பட்ட மரம், செடி கொடிகளை பூமிப்பந்தில் பரப்புவதில் எலி இனங்கள் மிக முக்கியமான பங்காற்றுவதாக ஆய்வில் தெரியவந்திருக்கிறது.

பொதுவாக எலி இனம் என்றாலே அது கிராமப்புறமாக இருந்தாலும் சரி, நகர்ப்புறமாக இருந்தாலும் சரி, மனிதர்களுக்கு மிகப்பெரிய தலைவலியாகவே பார்க்கப்படுகிறது. கிராமப்புற விவசாயிகளின் விளைந்த பயிர்களை நாசமாக்குவது முதல் நகர்ப்புறங்களில் சேமித்துவைக்கப்பட்டிருக்கும் தானியங்களை தின்று தீர்ப்பது வரை, எலி இனம் என்றாலே மனிதர்களுக்கு பெரும் வெறுப்பும், விரோதமும் தான் நிலவுகிறது.

ஆனால் இந்த எலி இனங்கள் இயற்கைக்கு ஒரு மிகப்பெரிய சேவை செய்வதாக கூறுகிறார் நெதர்லாந்து நாட்டைச்சேர்ந்த விஞ்ஞானி பேட்ரிக் ஜேன்சன்.

மிகப்பெரிய மரங்கள் முதல் சின்னஞ்சிறு செடிகொடிகள் வரை பல்வேறு வகையான தாவர விதைகளை, கொட்டைகளை பார தூரமாக கொண்டு சென்று சம்பந்தப்பட்ட மரம் செடி கொடிகளை பூமிப்பந்தில் பரப்புவதில் எலி இனங்கள் மிக முக்கியமான பங்காற்றுவதாக கூறுகிறார் இவர்.

தனது இந்த கருத்தை இவர் ஒரு ஆய்வின் மூலம் உறுதி செய்திருக்கிறார்.

இதற்காக இவர் சுமார் அரை மீட்டர் நீளமுள்ள அகவுடிஸ் என்று அழைக்கப்படும் ஒருவகை பெருச்சாளிகளை தேர்வு செய்தார். தென்னமெரிக்க காடுகளில் காணப்படும் இவற்றின் கழுத்தில் கண்காணிப்புக்கருவிகளை பொருத்தினார்.

இவற்றை தொடர்ந்து மாதக்கணக்கில் கண்காணித்த பின்னர் இவர் வெளியிட்டிருக்கும் ஆய்வு முடிவுகளின் படி, ஒரு குறிப்பிட்ட மரத்தின் விதைகளை, முதலில் எடுத்துச்சென்ற பெருச்சாளி அதை சுமார் 9 மீட்டர் தொலைவில் கொண்டு சென்று புதைத்து வைத்தது. அதை எடுத்துச்சென்ற இரண்டாவது பெருச்சாளி, ஐந்துமீட்டர் தொலைவில் புதைத்துவைத்தது. இப்படியே ஒன்றிலிருந்து ஒன்றாக 25 பெருச்சாளிகள் இந்த விதையை பறித்துச்சென்றன. முடிவில் இந்த விதை சுமார் 70 மீட்டர் தொலைவுக்கு கொண்டு செல்லப்பட்டது.

விளைவு, இந்த விதை அதன் தாய்மரத்திலிருந்து 70 மீட்டர் தொலைவில் முளைப்பதற்கு இந்த பெருச்சாளிகள் காரணமாக அமைந்திருந்ததை உறுதிப்படுத்திய பேட்ரிக் ஜான்சன், பூமியில் விதைகள் பரவுவதற்கு எலி இனங்கள் முக்கிய பங்காற்றுவதாக தெரிவிக்கிறார்.

அதுமட்டுமல்லாமல், இப்படி விதைகள் பரவலாக சென்று விதைக்கப்பட்டால் தான் இந்த மரம் அல்லது செடிகள், தம் இனத்தைச்சேர்ந்த மற்ற தாவரங்களுடன் இணைந்து மரபின கலப்பு உருவாக வழி பிறக்கும் என்றும் அவர் வலியுறுத்துகிறார்.

எனவே எலி இனங்கள் மனிதர்களுக்கு வேண்டுமானால் நண்பனாக இல்லாமலிருக்கலாம், இயற்கைக்கு அது நண்பன் தான் என்கிறார் அவர்.

The lab that lets you experiment from home

(Image: David Parry/PA Wire/Press Association Images)

In the basement of the Science Museum in London, there’s an orchestra played by ghosts. Drums, marimbas and cymbals play all day and all night. The music is occasionally pleasant, sometimes discordant, and certainly eerie if you are in the room listening to it.

The ghosts are actually real people, based all over the world, connected to the exhibition via the web. This “Universal Orchestra” is part of an exhibition in London designed by Google, called Web Lab. The aim is to illuminate the workings of the ephemeral digital world by giving it some tangibility and physical heft.

Visitors to the museum can play with five interactive experiments, from the orchestra to a robot arm that draws their face in sand. But so can anybody, from anywhere in the world. VisitGoogle’s Web Lab website and you join a queue to control the actual experiments from afar. Cameras and microphones monitor the responses to what you do.

Program a few notes on the website, for example, and the robots of the Universal Orchestra will smash drums and plink cymbals inside the museum. Listen carefully, and you can even hear the fragments of conversations and laughter of people in the exhibit at the time, acting as both audience and fellow musicians.

In another experiment, Sketchbot, you can upload your face via a webcam - or via a camera if you’re inside the museum - and a robot arm will draw a version of your mug on a surface of sand. This one provides a small taste of the coming “Internet of Things”, where our objects and possessions will be wired up to the internet, enabling us to control them from afar.

A third exhibit arguably works better on the web than it does in the museum. Called Data Tracer, it allows people to search for an image, and see whereabouts on the vast network of cables and servers that image actually resides. On a map of the world, you see the path the image takes to reach your screen, be it from Chicago or Sydney. In the exhibit, that map is mounted on the wall, but web visitors see a dynamic animation.

The experiments combine to bring some welcome physicality to the internet and the idea of the digital cloud, where our photos, music and digital possessions are increasingly stored. It can sometimes be easy to forget or take for granted that the internet is a physical network of cables and servers, connecting actual places and people.

While some of the exhibits in Web Lab can occasionally be buggy and tricky to comprehend, the exhibition will improve over time. Google decided to launch the project in “beta”, as it does with many of its web products. That means any flaws will be worked out the more people visit - both physically and digitally.

Web Lab runs at the Science Museum in London until 20 June 2013