On Dec. 5, 2010, Cassini first detected the storm that has been raging ever since. It appears approximately 35 degrees north latitude of Saturn. Pictures from Cassini's imaging cameras show the storm wrapping around the entire planet covering approximately 2 billion square miles (4 billion square kilometers).
The storm is about 500 times larger than the biggest storm previously seen by Cassini during several months from 2009 to 2010. Scientists studied the sounds of the new storm's lightning strikes and analyzed images taken between December 2010 and February 2011. Data from Cassini's radio and plasma wave science instrument showed the lightning flash rate as much as 10 times more frequent than during other storms monitored since Cassini's arrival to Saturn in 2004. The data appear in a paper published this week in the journal Nature.
"Cassini shows us that Saturn is bipolar," said Andrew Ingersoll, an author of the study and a Cassini imaging team member at the California Institute of Technology in Pasadena, Calif. "Saturn is not like Earth and Jupiter, where storms are fairly frequent. Weather on Saturn appears to hum along placidly for years and then erupt violently. I'm excited we saw weather so spectacular on our watch."
At its most intense, the storm generated more than 10 lightning flashes per second. Even with millisecond resolution, the spacecraft's radio and plasma wave instrument had difficulty separating individual signals during the most intense period. Scientists created a sound file from data obtained on March 15 at a slightly lower intensity period.
Cassini has detected 10 lightning storms on Saturn since the spacecraft entered the planet's orbit and its southern hemisphere was experiencing summer, with full solar illumination not shadowed by the rings. Those storms rolled through an area in the southern hemisphere dubbed "Storm Alley." But the sun's illumination on the hemispheres flipped around August 2009, when the northern hemisphere began experiencing spring.
"This storm is thrilling because it shows how shifting seasons and solar illumination can dramatically stir up the weather on Saturn," said Georg Fischer, the paper's lead author and a radio and plasma wave science team member at the Austrian Academy of Sciences in Graz. "We have been observing storms on Saturn for almost seven years, so tracking a storm so different from the others has put us at the edge of our seats."
The storm's results are the first activities of a new "Saturn Storm Watch" campaign. During this effort, Cassini looks at likely storm locations on Saturn in between its scheduled observations. On the same day that the radio and plasma wave instrument detected the first lightning, Cassini's cameras happened to be pointed at the right location as part of the campaign and captured an image of a small, bright cloud. Because analysis on that image was not completed immediately, Fischer sent out a notice to the worldwide amateur astronomy community to collect more images. A flood of amateur images helped scientists track the storm as it grew rapidly, wrapping around the planet by late January 2011.
The new details about this storm complement atmospheric disturbances described recently by scientists using Cassini's composite infrared spectrometer and the European Southern Observatory's Very Large Telescope. The storm is the biggest observed by spacecraft orbiting or flying by Saturn. NASA's Hubble Space Telescope captured images in 1990 of an equally large storm.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena manages the mission for the agency's Science Mission Directorate in Washington. The radio and plasma wave science team is based at the University of Iowa, Iowa City, where the instrument was built. The imaging team is based at the Space Science Institute in Boulder, Colo. JPL is a division of the California Institute of Technology, Pasadena.
A set of glasses packed with technology normally seen in smartphones and games consoles is the main draw at one of the featured stands at this year’s Royal Society Summer Science Exhibition.
But the exhibit isn’t about the latest gadget must-have, it’s all about aiding those with poor vision and giving them greater independence.
‘We want to be able to enhance vision in those who’ve lost it or who have little left or almost none,’ explains Dr Stephen Hicks of the Department of Clinical Neurology at Oxford University. ‘The glasses should allow people to be more independent – finding their own directions and signposts, and spotting warning signals,’ he says.
Technology developed for mobile phones and computer gaming – such as video cameras, position detectors, face recognition and tracking software, and depth sensors – is now readily and cheaply available. So Oxford researchers have been looking at ways that this technology can be combined into a normal-looking pair of glasses to help those who might have just a small area of vision left, have cloudy or blurry vision, or can’t process detailed images.
The glasses should be appropriate for common types of visual impairment such as age-related macular degeneration and diabetic retinopathy. NHS Choices estimates around 30% of people who are over 75 have early signs of age-related macular degeneration, and about 7% have more advanced forms.
‘The types of poor vision we are talking about are where you might be able to see your own hand moving in front of you, but you can’t define the fingers,’ explains Stephen.
The glasses have video cameras mounted at the corners to capture what the wearer is looking at, while a display of tiny lights embedded in the see-through lenses of the glasses feed back extra information about objects, people or obstacles in view.
In between, a smartphone-type computer running in your pocket recognises objects in the video image or tracks where a person is, driving the lights in the display in real time.
The extra information the glasses display about their surroundings should allow people to navigate round a room, pick out the most relevant things and locate objects placed nearby.
‘The glasses must look discrete, allow eye contact between people and present a simplified image to people with poor vision, to help them maintain independence in life,’ says Stephen. These guiding principles are important for coming up with an aid that is acceptable for people to wear in public, with eye contact being so important in social relationships, he explains.
The see-through display means other people can see you, while different light colours might allow different types of information to be fed back to the wearer, Stephen says. You could have different colours for people, or important objects, and brightness could tell you how near things were.
Stephen even suggests it may be possible for the technology to read back newspaper headlines. He says something called optical character recognition is coming on, so it possible to foresee a computer distinguishing headlines from a video image then have these read back to the wearer through earphones coming with the glasses. A whole stream of such ideas and uses are possible, he suggests. There are barcode readers in some mobile phones that download the prices of products; such barcode and price tag readers could also be useful additions to the glasses.
Stephen believes these hi-tech glasses can be realised for similar costs as smartphones – around £500. For comparison, a guide dog costs around £25-30,000 to train, he estimates.
He adds that people will have to get used to the extra information relayed on the glasses’ display, but that it might be similar to physiotherapy – the glasses will need to be tailored for individuals, their vision and their needs, and it will take a bit of time and practise to start seeing the benefits.
The exhibit at the Royal Society will take visitors through how the technology will work. ‘The primary aim is to simulate the experience of a visual prosthetic to give people an idea of what can be seen and how it might look,’ Stephen says.
A giant screen with video images of the exhibition floor itself will show people-tracking and depth perception at work. Another screen will invite visitors to see how good they are at navigating with this information. A small display added to the lenses of ski goggles should give people sufficient information to find their way round a set of tasks. An early prototype of a transparent LED array for the eventual glasses will also be on display.
All of this is very much at an early stage. The group is still assembling prototypes of their glasses. But as well as being one of the featured stands at the Royal Society’s exhibition, they have funding from the National Institute of Health Research to do a year-long feasibility study and plan to try out early systems with a few people in their own homes later this year.
Source: PhysOrg - Resarch provided by Oxford University
Although this scenario is still several decades away, researchers have been making significant progress in developing early types of biomolecular computers.
In a recent study published in Nano Letters, Computer Science Professor Ehud Shapiro and coauthors from the Weizmann Institute of Science in Rehovot, Israel, have developed a biomolecular computer that can autonomously sense many different types of molecules simultaneously. In the future, this sensing ability could be integrated with a vast biomedical knowledge of diseases to enable computers to decide which drugs to release.
“We envision nanometer-sized computing devices (made of biomolecules) to roam our bodies in search of diseases in their early stage,” coauthor Binyamin Gil from the Weizmann Institute of Science told PhysOrg.com. “These devices would have the ability to sense disease indicators, diagnose the disease, and treat it by administering or activating a therapeutic biomolecule. They could be delivered to the bloodstream or operate inside cells of a specific organ or tissue and be given as a preventive care.”
The development builds on the researchers’ previous demonstration of a biomolecular computer that consists of a two-state system made of biological components (DNA and a restriction enzyme). The computer, which operates in vitro, starts from the Yes state. In each computation step, the computer checks one disease indicator. If all of the indicators for the tested disease are present, the computation ends in the Yes state, namely it makes a positive diagnosis; if at least one disease indicator is not detected, it ends in the No state.
Previously, Shapiro's group showed that this biomolecular computer could detect disease indicators from mRNA expression levels and mutations. In the current study, the researchers have expanded the computer’s ability to also detect disease indicators from miRNAs, proteins, and small molecules such as ATP. At the same time, the computer’s detection method is simpler than before, requiring fewer components and fewer interactions with the disease indicators.
As the researchers explain, sensing a combination of several disease indicators is much more useful than sensing just one, since it allows for better accuracy and greater sensitivity to differences between diseases. For example, they note that in the case of thyroid cancer, the presence of the protein thyroglobulin and the hormone calcitonin can enable a much more reliable diagnosis than if only one of these disease indicators was detected.
Although the ability to detect several disease indicators marks an important step toward in vivo biomolecular computers and programmable drugs, there are still many obstacles that researchers must overcome in the process.
“The biggest challenge is operating such devices in living surrounding like the blood stream or cell's cytoplasm,” Gil said. “Currently we are developing devices that rely on simpler machinery (e.g. no restriction enzyme) or on the cell's own machinery.”
Mike Scharf, the O. Wayne Rollins/Orkin Chair in Molecular Physiology and Urban Entomology, said his laboratory has discovered a cocktail of enzymes from the guts of termites that may be better at getting around the barriers that inhibit fuel production from woody biomass. The Scharf Laboratory found that enzymes in termite guts are instrumental in the insects' ability to break down the wood they eat.
The findings, published in the early online version of the journal PLoS One, are the first to measure the sugar output from enzymes created by the termites themselves and the output from symbionts, small protozoa that live in termite guts and aid in digestion of woody material.
"For the most part, people have overlooked the host termite as a source of enzymes that could be used in the production of biofuels. For a long time it was thought that the symbionts were solely responsible for digestion," Scharf said. "Certainly the symbionts do a lot, but what we've shown is that the host produces enzymes that work in synergy with the enzymes produced by those symbionts. When you combine the functions of the host enzymes with the symbionts, it's like one plus one equals four."
Scharf and his research partners separated the termite guts, testing portions that did and did not contain symbionts on sawdust to measure the sugars created.
Once the enzymes were identified, Scharf and his team worked with Chesapeake Perl, a protein production company in Maryland, to create synthetic versions. The genes responsible for creating the enzymes were inserted into a virus and fed to caterpillars, which then produce large amounts of the enzymes. Tests showed that the synthetic versions of the host termite enzymes also were very effective at releasing sugar from the biomass.
They found that the three synthetic enzymes function on different parts of the biomass.
Two enzymes are responsible for the release of glucose and pentose, two different sugars. The other enzyme breaks down lignin, the rigid compound that makes up plant cell walls.
Lignin is one of the most significant barriers that blocks the access to sugars contained in biomass. Scharf said it's possible that the enzymes derived from termites and their symbionts, as well as synthetic versions, could be more effective at removing that lignin barrier.
Sugars from plant material are essential to creating biofuels. Those sugars are fermented to make products such as ethanol.
"We've found a cocktail of enzymes that create sugars from wood," Scharf said. "We were also able to see for the first time that the host and the symbionts can synergistically produce these sugars."
Next, Scharf said his laboratory and collaborators would work on identifying the symbiont enzymes that could be combined with termite enzymes to release the greatest amount of sugars from woody material. Combining those enzymes would increase the amount of biofuel that should be available from biomass.
The team at Exeter University used ‘phase-change alloys’ that move from an amorphous to fully crystallised state when subject to a current or light pulse.
‘What we are doing is trying to build electronic systems that mimic, in a simple way, the functionality of the basic building blocks of mammalian brains — namely neurons and synapses,’ project lead Prof David Wright of Exeter told The Engineer.
In conventional computers memory and processing units are physically separate, and data has to be continually shunted between the two, creating ‘bottlenecks’.
‘This slows everything down and wastes a lot of power and is the main reason chip manufacturers have moved to multi-core processors,’ Wright said.
The team turned to neurons for inspiration, noting that they make no real distinction between memory and computation. Looking for possible artificial substitutes the researchers came across so-called ‘phase-change materials’ that flip between amorphous and crystal states, in doing so inducing an electrical conductivity difference of up to five orders of magnitude and a large refractive index change.
Using laser pulses to induce the phase changes in germanium-antimony-tellurium (GeSbTe) and silver-indium-antimony-tellurium (AgInSbTe), the team was able to perform basic arithmetic and data storage.
‘A very simple model of a neuron is known as the “integrate and fire” model in which the neuron integrates, or accumulates, excitations applied to its input and fires a pulse along its output after a certain threshold has been passed.
‘We’ve shown that phase-change materials have a natural accumulation and threshold property, which makes them a good candidate for simple implementation of a hardware neuron,’ Wright said.
The upshot of the work is that these phase-change components could potentially be connected in networks via structures akin to synapses — potentially opening up an entirely novel way of computing.
‘The strength of these synaptic connections is altered by learning and experience — a common phrase to describe this is “neurons that fire together, wire together”.
‘We think that phase-change devices could also be used to make synapses — since the electrical resistance, or optical reflectivity, of phase-change materials depends on their excitation history,’ Wright said.
Indeed, shortly after publication of the Exeter work, a team from Stanford University in the US headed by Prof Philip Wong demonstrated just that, creating a nanoscale device with interconnected phase-change components.
Taking inspiration from floating seeds, scientists from the Biomimetics-Innovation-Centre (B-I-C) in Germany have developed a promising new anti-fouling surface that is toxin-free.
The new surface is based on a seed from a species of palm tree that is dispersed by ocean currents. Suspecting that certain seeds may have specialized surfaces that gave them the ability to remain free of fouling to allow them to disperse further, the researchers floated seeds from 50 species in the North Sea for 12 weeks. At the end of the 12-week period, the seeds of 12 species showed no fouling at all.
"We then began by examining the micro-structure of the seeds' surfaces, to see if we could translate them into an artificial surface. The seeds we chose to mimic had a hairy-like structure," says Katrin Mühlenbruch, a PhD researcher at BIC. "This structure might be especially good at preventing fouling because the fibers constantly move, preventing marine organisms from finding a place to settle."
To create an artificial surface similar to the seeds, the researchers used a silicone base with fibers covering the surface. The new surface is currently being trialed by floating it in the sea. Ms. Mühlenbruch says that while the initial results are "quite good," there is still a long way to go.
Following on from the examination of the structure of the seeds' surface, the B-I-C researchers also plan to analyze the chemical composition of the seeds' surface to find out whether this adds to their anti-fouling properties.
"Our aim is to provide a new toxin-free and bio-inspired ship coating," says Ms. Mühlenbruch. "This would prevent environmental damage while allowing ships to operate efficiently."
The brand new Shadow eBike hosts only a bit of wiring hidden away in the front hub, still placing it far ahead its competition which will usually comes entangled within an array of wires on its frame. But beyond its sleek and clean form, this eBike also boasts a USB port, a charging port, an LED battery power display, regenerative breaks and a wheel that doubles up as a generator!
The Shadow eBike’s wireless attributes means that there are no electrical connections exposed to the elements, removing the possibility of accidental severing or short circuiting. All of the bike’s circuitry is in-frame, including its electric motor, lithium polymer battery, magnetic regenerative brakes, throttle and the pedal-assist functions which use a 2.5 GHz frequency-hopping “spread-spectrum technology”. As such, Toronto-based Daymak feel justified in calling the Shadow “the world’s first wireless power-assist electric bicycle.”
Daymak offers the Shadow eBike equipped with either a 250W or 350W electric motor, and a 36V 10AH lithium-ion battery that can provide an average range of around 12 to 15 miles running on just motor power. With pedal-assisted power, this range is extended to 22 to 25 miles. The battery takes between four and five hours to completely recharge and is good for 750 to 800 cycles. The bike’s wheel also doubles up as a generator able to charge devices via the USB port, and a regenerative braking system sends a current back to the batteries.
If you are concerned that the bike’s wireless design leaves it vulnerable to hacking, don’t worry. Daymak says that each Shadow eBike wireless component is paired and the odds of it being affected by outside parties is less than one in a billion. The use of wireless technology also means the Shadow is set up for future upgrades that will one day enable it to interact with smartphones and even PCs.
The bike was set to be released on April 30th, and has been given a retail price of $1,999.
The researchers have developed an artificial DNA "stealth" linkage using click chemistry, a highly-efficient chemical reaction, to join together DNA strands without disrupting the genetic code.
The breakthrough, published online in the journal PNAS this week (27 June), means long sections of DNA can be created quickly and efficiently by chemical methods.
DNA strands are widely used in biological and medical research, and clean and effective methods of making longer sections are of great value. Current techniques rely on the use of enzymes as biological catalysts. Joining DNA chemically is particularly interesting as it does not depend on enzymes so can be carried out on a large scale under a variety of conditions.
Co-author of the paper Tom Brown, Professor of Chemical Biology at the University of Southampton, says: "We believe this is the first example of a chemical method of joining together longer strands of DNA that works well.
"Typically, synthesised DNA strands will be up to 150 bases; beyond that they are very difficult to make. We have doubled that to 300 and we can go further. We can also join together heavily modified DNA strands, used in medical research for example, which normal enzymes might not want to couple together."
The Southampton team investigated whether the artificial links would be tolerated biologically within the bacteria E.coli.
"The genetic code could still be correctly read," says co-investigator Dr Ali Tavassoli.
"The artificial linkages act in stealth as they go undetected by the organism; the gene was functional despite containing 'scars' in its backbone. This opens up all sorts of possibilities."
The team is now hoping to secure funding to explore potential applications of the technology.
Prior to this discovery, such alloys were only able to revert to their original form in the much narrower range of -20 to 80 degrees Celsius. They have published their findings in the journal Science.
Superelastic alloys are metals that revert naturally back to their original shape after being bent or deformed by outside forces once those forces are removed, and are generally created by mixing two or more other metals together in certain combinations.
In this new effort, the research team added a small amount of nickel to an iron based alloy, which according to lead author Toshihiro Omori, in an email interview with Reuters, says makes their product far more elastic than anything else out there. He also said that because the ingredients for the new metal are plentiful, the resultant alloy should be very cheap to produce.
The reason that superelastic allows are able to revert to their prior shape is due to their unique crystal structure that allows all of the atoms it’s made of to shift as one when a force is applied, as opposed to normal metals where the force is diffused through the crystal structure changing it’s composition.
Superelastic alloys are used in many applications such as eyeglasses, antennas, and medical tools and equipment. Omori, says he hopes that this new alloy, because of its ability to revert in virtually any real world temperature conditions, can be used in buildings to protect against earthquake damage, or in other applications where things get hot under stress, such as in cars, airplanes and spacecraft.
Because many tall buildings are supported by metal beams, the thinking goes, if the those metal beams were made of a superelastic alloy, they would be able to snap back to their original positions after each gyration of the ground, rather than suffering compound trauma as the quake continues, making it much less likely that the building would crumble or fall.
TheNew York Timesreported Thursday thatTristane Banon, the French journalistwho has accused disgraced ex-IMF chief Dominique Strauss-Kahn of attempting to rape her back in 2003, was questioned jointly with DSK at a Paris police station for over two hours. This, of course, is on the heels of the high-profile rape allegations againstDSK made by a hotel maid in the U.S. According to theTimes, "The joint questioning, a normal part of sexual assault cases in France, could represent a last legal step for prosecutors before either bringing formal charges, or dropping the case." How does this joint questioning work?
Cécile Dehesdin, a reporter atSlate's French sister site,Slate.fr, says that this joint questioning isn't mandatory. If the accused rapist denies the charges, according to a French organization for women devoted to helping rape victims, the alleged victim can accept the joint questioning, refuse it outright, or ask that the face-to-face happen, not with the police, but with the judge who will eventually be in charge of investigating the case. In France, unlike in the U.S., the judge (juge d'instruction) is in charge of investigating for both the alleged victim and the accused. DSK has called Banon's accusations of rape "imaginary and slanderous" in a recent interview. For her part, Banon has always said sherelished the idea of facing DSK in person:
The police asked me if i'd agree to a face to face, of course I said yes. I'd like him to be facing me and telling me to my face that those are imaginary facts. I'd like to see him try and say that.
In this joint questioing, Dehesdin points out, the victim and alleged attacker are in the same room, but they don't address each other directly. They just answer the police or judge's questions. Whoever has conducted the questioning gives the information to the district attorney, who then decides if there is enough evidence to move forward with the case (updated to add: if the juge d'instruction has done the questioning, he doesn't need permission from the DA to pursue the case).
Even if the D.A. decides not to pursue the case, Banon has some recourse. Since she was questioned by police, she could refile the criminal complaint along with a civil complaint, and at that point the juge d'instruction would have to investigate. According topress reports in France, DSK did admit that he made a pass at her.