Cutting carbon emissions could have indirect effects on hunger

 

Thu, 06/11/2015 - 9:05am American Chemical Society As many of the world’s nations prepare and implement plans to cut greenhouse gas emissions, researchers say another critical factor needs to be considered. A new study has found for the first time that efforts to keep global temperatures in check will likely lead to more people going hungry. That risk, they say in Environmental Science & Technology, doesn’t negate the need for mitigation but highlights the importance of comprehensive policies. Previous studies have shown that climate change reduces how much food farms can produce, which could lead to more people suffering from hunger. Curbing the greenhouse gas emissions that lead to climate change can help maintain the yields of existing crops. But there might be indirect ways in which cutting emissions could actually put more people at risk of going hungry. For example, some grasses and other vegetation used for biofuels require agricultural land that might otherwise be used for food production. So, increased biofuel consumption could negatively affect the food supply. Also, the high cost of low-emissions technologies such as carbon capture and storage will be borne by consumers, who will then have less money to spend on food. Tomoko Hasegawa and colleagues wanted to get a better idea of how these pieces fit together. The researchers used multiple models to determine the effects of strict emissions cuts and found that many more people would be at risk of hunger than if those cuts weren’t in place. The team concludes that governments will have to take measures, such as increasing food aid, as they address climate change. Source: American Chemical Society

Longstanding problem put to rest

 

Thu, 06/11/2015 - 9:51am Larry Hardesty, MIT News Office Image: iStock (edited by MIT News) Comparing the genomes of different species—or different members of the same species—is the basis of a great deal of modern biology. DNA sequences that are conserved across species are likely to be functionally important, while variations between members of the same species can indicate different susceptibilities to disease. The basic algorithm for determining how much two sequences of symbols have in common—the “edit distance” between them—is now more than 40 years old. And for more than 40 years, computer science researchers have been trying to improve upon it, without much success. At the ACM Symposium on Theory of Computing (STOC), Massachusetts Institute of Technology (MIT) researchers will report that, in all likelihood, that’s because the algorithm is as good as it gets. If a widely held assumption about computational complexity is correct, then the problem of measuring the difference between two genomes—or texts, or speech samples, or anything else that can be represented as a string of symbols—can’t be solved more efficiently. In a sense, that’s disappointing, since a computer running the existing algorithm would take 1,000 years to exhaustively compare two human genomes. But it also means that computer scientists can stop agonizing about whether they can do better. “This edit distance is something that I’ve been trying to get better algorithms for since I was a graduate student, in the mid-’90s,” says Piotr Indyk, a professor of computer science and engineering at MIT and a co-author of the STOC paper. “I certainly spent lots of late nights on that—without any progress whatsoever. So at least now there’s a feeling of closure. The problem can be put to sleep.” Moreover, Indyk says, even though the paper hasn’t officially been presented yet, it’s already spawned two follow-up papers, which apply its approach to related problems. “There is a technical aspect of this paper, a certain gadget construction, that turns out to be very useful for other purposes as well,” Indyk says. Squaring off Edit distance is the minimum number of edits—deletions, insertions and substitutions—required to turn one string into another. The standard algorithm for determining edit distance, known as the Wagner-Fischer algorithm, assigns each symbol of one string to a column in a giant grid and each symbol of the other string to a row. Then, starting in the upper left-hand corner and flooding diagonally across the grid, it fills in each square with the number of edits required to turn the string ending with the corresponding column into the string ending with the corresponding row. Computer scientists measure algorithmic efficiency as computation time relative to the number of elements the algorithm manipulates. Since the Wagner-Fischer algorithm has to fill in every square of its grid, its running time is proportional to the product of the lengths of the two strings it’s considering. Double the lengths of the strings, and the running time quadruples. In computer parlance, the algorithm runs in quadratic time. That may not sound terribly efficient, but quadratic time is much better than exponential time, which means that running time is proportional to 2N, where N is the number of elements the algorithm manipulates. If on some machine a quadratic-time algorithm took, say, a hundredth of a second to process 100 elements, an exponential-time algorithm would take about 100 quintillion years. Theoretical computer science is particularly concerned with a class of problems known as NP-complete. Most researchers believe that NP-complete problems take exponential time to solve, but no one’s been able to prove it. In their STOC paper, Indyk and his student Artūrs Bačkurs demonstrate that if it’s possible to solve the edit-distance problem in less-than-quadratic time, then it’s possible to solve an NP-complete problem in less-than-exponential time. Most researchers in the computational-complexity community will take that as strong evidence that no subquadratic solution to the edit-distance problem exists. Can’t get no satisfaction The core NP-complete problem is known as the “satisfiability problem”: Given a host of logical constraints, is it possible to satisfy them all? For instance, say you’re throwing a dinner party, and you’re trying to decide whom to invite. You may face a number of constraints: Either Alice or Bob will have to stay home with the kids, so they can’t both come; if you invite Cindy and Dave, you’ll have to invite the rest of the book club, or they’ll know they were excluded; Ellen will bring either her husband, Fred, or her lover, George, but not both; and so on. Is there an invitation list that meets all those constraints? In Indyk and Bačkurs’ proof, they propose that, faced with a satisfiability problem, you split the variables into two groups of roughly equivalent size: Alice, Bob and Cindy go into one, but Walt, Yvonne and Zack go into the other. Then, for each group, you solve for all the pertinent constraints. This could be a massively complex calculation, but not nearly as complex as solving for the group as a whole. If, for instance, Alice has a restraining order out on Zack, it doesn’t matter, because they fall in separate subgroups: It’s a constraint that doesn’t have to be met. At this point, the problem of reconciling the solutions for the two subgroups—factoring in constraints like Alice’s restraining order—becomes a version of the edit-distance problem. And if it were possible to solve the edit-distance problem in subquadratic time, it would be possible to solve the satisfiability problem in subexponential time. Source: Massachusetts Institute of Technology

Synthetic immune organ produces antibodies

 

Thu, 06/11/2015 - 9:32am Anne Ju, Cornell University. When exposed to a foreign agent, such as an immunogenic protein, B cells in lymphoid organs undergo germinal center reactions. The image on the left is an immunized mouse spleen with activated B cells (brown) that produce antibodies. At right, top: a scanning electron micrograph of porous synthetic immune organs that enable rapid proliferation and activation of B cells into antibody-producing cells. At right, bottom: primary B cell viability and distribution is visible 24 hrs following encapsulation procedure. Images: Singh labCornell Univ. engineers have created a functional, synthetic immune organ that produces antibodies and can be controlled in the lab, completely separate from a living organism. The engineered organ has implications for everything from rapid production of immune therapies to new frontiers in cancer or infectious disease research. The immune organoid was created in the lab of Ankur Singh, assistant professor of mechanical and aerospace engineering, who applies engineering principles to the study and manipulation of the human immune system. The work was published online in Biomaterials and will appear later in print. The synthetic organ is bio-inspired by secondary immune organs like the lymph node or spleen. It is made from gelatin-based biomaterials reinforced with nanoparticles and seeded with cells, and it mimics the anatomical microenvironment of lymphoid tissue. Like a real organ, the organoid converts B cells—which make antibodies that respond to infectious invaders—into germinal centers, which are clusters of B cells that activate, mature and mutate their antibody genes when the body is under attack. Germinal centers are a sign of infection and are not present in healthy immune organs. The engineers have demonstrated how they can control this immune response in the organ and tune how quickly the B cells proliferate, get activated and change their antibody types. According to their paper, their 3-D organ outperforms existing 2-D cultures and can produce activated B cells up to 100 times faster. The immune organ, made of a hydrogel, is a soft, nanocomposite biomaterial. The engineers reinforced the material with silicate nanoparticles to keep the structure from melting at the physiologically relevant temperature of 98.6 degrees. The organ could lead to increased understanding of B cell functions, an area of study that typically relies on animal models to observe how the cells develop and mature. What’s more, Singh said, the organ could be used to study specific infections and how the body produces antibodies to fight those infections—from Ebola to HIV. “You can use our system to force the production of immunotherapeutics at much faster rates,” he said. Such a system also could be used to test toxic chemicals and environmental factors that contribute to infections or organ malfunctions. The process of B cells becoming germinal centers is not well understood, and in fact, when the body makes mistakes in the genetic rearrangement related to this process, blood cancer can result. “In the long run, we anticipate that the ability to drive immune reaction ex vivo at controllable rates grants us the ability to reproduce immunological events with tunable parameters for better mechanistic understanding of B cell development and generation of B cell tumors, as well as screening and translation of new classes of drugs,” Singh said. Source: Cornell University

The 17 Ingeniously Designed Products You Need In Your Life

 

 

These products are awesome simply because they were designed that way. All them are really amazing, and they will help you get through your day.     http://whattodowhenyour-bored.com

The Knot You Should Not Be Without

 

The Knot You Should Not Be Without Unlike other bulky supplemental power banks, BOLD Knot is a stylish, pocket-sized charger and a power bank for any smartphone. It uses a fashionable, knot-shaped design that’s unrecognizable as a peripheral charger. Tiny battery pack… big power! Get up to 3 hours of extra talk time, 2.5 hours of internet, or 8 hours of music. Designer: BOLD Gadgets source: www.yankodesign.com

At near absolute zero, molecules may start to exhibit exotic states of matter

 

MIT researchers have successfully cooled a gas of sodium potassium (NaK) molecules to a temperature of 500 nanokelvin. In this artist's illustration, the NaK molecule is represented with frozen spheres of ice merged together: the smaller sphere on the left represents a sodium atom, and the larger sphere on the right is a potassium atom. Credit: Illustration: Jose-Luis Olivares/MIT The air around us is a chaotic superhighway of molecules whizzing through space and constantly colliding with each other at speeds of hundreds of miles per hour. Such erratic molecular behavior is normal at ambient temperatures. But scientists have long suspected that if temperatures were to plunge to near absolute zero, molecules would come to a screeching halt, ceasing their individual chaotic motion and behaving as one collective body. This more orderly molecular behavior would begin to form very strange, exotic states of matter -- states that have never been observed in the physical world. Now experimental physicists at MIT have successfully cooled molecules in a gas of sodium potassium (NaK) to a temperature of 500 nanokelvins -- just a hair above absolute zero, and over a million times colder than interstellar space. The researchers found that the ultracold molecules were relatively long-lived and stable, resisting reactive collisions with other molecules. The molecules also exhibited very strong dipole moments -- strong imbalances in electric charge within molecules that mediate magnet-like forces between molecules over large distances. Martin Zwierlein, professor of physics at MIT and a principal investigator in MIT's Research Laboratory of Electronics, says that while molecules are normally full of energy, vibrating and rotating and moving through space at a frenetic pace, the group's ultracold molecules have been effectively stilled -- cooled to average speeds of centimeters per second and prepared in their absolute lowest vibrational and rotational states. "We are very close to the temperature at which quantum mechanics plays a big role in the motion of molecules," Zwierlein says. "So these molecules would no longer run around like billiard balls, but move as quantum mechanical matter waves. And with ultracold molecules, you can get a huge variety of different states of matter, like superfluid crystals, which are crystalline, yet feel no friction, which is totally bizarre. This has not been observed so far, but predicted. We might not be far from seeing these effects, so we're all excited." Zwierlein, along with graduate student Jee Woo Park and postdoc Sebastian Will -- all of whom are members of the MIT-Harvard Center of Ultracold Atoms -- have published their results in the journal Physical Review Letters. Sucking away 7,500 kelvins Every molecule is composed of individual atoms that are bonded together to form a molecular structure. The simplest molecule, resembling a dumbbell, is made up of two atoms connected by electromagnetic forces. Zwierlein's group sought to create ultracold molecules of sodium potassium, each consisting of a single sodium and potassium atom. However, due to their many degrees of freedom -- translation, vibration, and rotation -- cooling molecules directly is very difficult. Atoms, with their much simpler structure, are much easier to chill. As a first step, the MIT team used lasers and evaporative cooling to cool clouds of individual sodium and potassium atoms to near absolute zero. They then essentially glued the atoms together to form ultracold molecules, applying a magnetic field to prompt the atoms to bond -- a mechanism known as a "Feshbach resonance," named after the late MIT physicist Herman Feshbach. "It's like tuning your radio to be in resonance with some station," Zwierlein says. "These atoms start to vibrate happily together, and form a bound molecule." The resulting bond is relatively weak, creating what Zwierlein calls a "fluffy" molecule that still vibrates quite a bit, as each atom is bonded over a long, tenuous connection. To bring the atoms closer together to create a stronger, more stable molecule, the team employed a technique first reported in 2008 by groups from the University of Colorado, for potassium rubidium (KRb) molecules, and the University of Innsbruck, for non-polar cesium­ (Ce2­) molecules. For this technique, the newly created NaK molecules were exposed to a pair of lasers, the large frequency difference of which exactly matched the energy difference between the molecule's initial, highly vibrating state, and its lowest possible vibrational state. Through absorption of the low-energy laser, and emission into the high-energy laser beam, the molecules lost all their available vibrational energy. With this method, the MIT group was able to bring the molecules down to their lowest vibrational and rotational states -- a huge drop in energy. "In terms of temperature, we sucked away 7,500 kelvins, just like that," Zwierlein says. Chemically stable In their earlier work, the Colorado group observed a significant drawback of their ultracold potassium rubidium molecules: They were chemically reactive, and essentially came apart when they collided with other molecules. That group subsequently confined the molecules in crystals of light to inhibit such chemical reactions. Zwierlein's group chose to create ultracold molecules of sodium potassium, as this molecule is chemically stable and naturally resilient against reactive molecular collisions. "When two potassium rubidium molecules collide, it is more energetically favorable for the two potassium atoms and the two rubidium atoms to pair up," Zwierlein says. "It turns out with our molecule, sodium potassium, this reaction is not favored energetically. It just doesn't happen." In their experiments, Park, Will, and Zwierlein observed that their molecular gas was indeed stable, with a relatively long lifetime, lasting about 2.5 seconds. "In the case where molecules are chemically reactive, one simply doesn't have time to study them in bulk samples: They decay away before they can be cooled further to observe interesting states," Zwierlein says. "In our case, we hope our lifetime is long enough to see these novel states of matter." By first cooling atoms to ultralow temperatures and only then forming molecules, the group succeeded in creating an ultracold gas of molecules, measuring one thousand times colder than what can be achieved by direct cooling techniques. To begin to see exotic states of matter, Zwierlein says molecules will have to be cooled still a bit further, to all but freeze them in place. "Now we're at 500 nanokelvins, which is already fantastic, we love it. A factor of 10 colder or so, and the music starts playing." This research was supported in part by the National Science Foundation, the Air Force Office of Scientific Research, the Army Research Office, and the David and Lucile Packard Foundation.

Microsoft Surface Hub launches in September.

 

Businesses will be able to get their hands on the Surface Hub later this year Image Gallery (3 images) Microsoft has released pricing and availability information for its enterprise focused Surface Hub, announced back in January of this year. The hardware is pitched as an all-in-one solution for collaboration in meetings, consisting of a large display, active stylus, and a whole host of sensors and connectivity options. Running on Microsoft's upcoming Windows 10 operating system, the Surface Hub is essentially a huge, wall-mounted all-in-one PC. Users will interact with the large touch panel via OneNote whiteboard, making use of low-latency, active stylus tech that's designed to make it feel like you're putting pen to paper. Certain apps like Skype for Business are built in, but it will also run universal Windows apps. It looks to be an attractive and versatile piece of business hardware, with some useful flairs thrown in. For example, it'll jump right into the whiteboard app when the pen is picked up, and Skype meetings can be initiated with just a single tap. The hardware is pretty full-featured, with stereo speakers up front, a mic, a pair of wide-angle 1080p cameras, along with infrared and ambient light sensors. There are two sizes of the Surface Hub on offer– a 55-inch 1,920 x 1,080 variant, and a 84-inch, 3,840 x 2,140 option. The smaller panel runs on a 4th generation Intel Core i5 chip with integrated HD 4600 graphics, while its big brother runs on a Core i7 with a Nvidia Quadro K2200 GPU. So the big news today? We actually known when these monsters will start making their way into meeting rooms. Microsoft will start taking Surface Hub orders on July 1, with units expected to ship to 24 markets (including the US) in September. There's a big difference in pricing between the two models, with the 55-inch Surface Hub coming in at US$6,999, and the 84-inch version hitting a much higher $19,999 price point.   Source: Microsoft

Retrofittable electric engine adds power and safety to light aircraft

 

Additional electric engine adds safety and power to light aircraft (Credit: Universidad Carlos III de Madrid) Image Gallery (5 images) Small, single-engine aircraft are the mainstay of recreational flying, and provide many hours of generally safe enjoyment for hundreds of thousands of enthusiasts worldwide. However, with only one engine on-board, they are also often only a small malfunction away from becoming a heavy, unpowered glider in dire need of somewhere to land. To help improve this situation, researchers at Universidad Carlos III de Madrid (UC3M) and AXTER Aerospace have created an auxiliary electric propulsion unit designed to be installed in conventionally-powered light aircraft to both increase available power and provide extra range in the event of an engine failure. Primarily aimed at improving the safety of light passenger aircraft with masses of up to 750 kg (1,650 lb), the retrofittable electric propulsion system has been created in direct response to a perceived need in the light aircraft space. "We are trying to saves lives and prevent accidents related to loss of power during flights, when the engine fails or the fuel runs out," says Miguel Ángel Suárez, from AXTER Aerospace. "We mustn’t forget that every year in Europe and USA there are an average of 600 accidents, 70 deaths and 24 million euros (US$27 million) in losses recorded." The new arrangement sees an electric engine coupled to the conventional engine via the conventional drive system. There's also a high-efficiency lithium battery charged by the plane’s conventional engine, and an automatic electronic control system that automatically adjusts the electric drive motor to the needs of the plane. "If there is a problem with the main engine, this electric engine will start to function, which will provide an additional range of about 20 kilometers, enough for the pilot to land safely," said Andrés Barrado, head of the UC3M Electric Power Systems group. An extra 20 km (12 miles) may not seem a lot, but given that most light aircraft fly in a pattern not too far from their originating airfield, it could make the difference between returning to the safety of the airport or crashing in a field. Serendipitously, the emergency propulsion system can also add around 40 extra horsepower (30 kW), as needed and when selected by the pilot. Not quite in the realm of a super-powered electric unit like the Siemens 260 kW (340 hp) monster, perhaps, but a handy addition to the lowly-powered engines of many light planes nonetheless. "We maximize the capacity of the battery in generating movement with the electric engine, and we have found that we can also use the system as a hybrid for light aircraft: the pilot can activate it when she wants, adding up to 40 horsepower for take-offs or whatever is needed," said Daniel Cristobal, from AXTER Aerospace. Currently being promoted and patented around the world, the creators claim that their system can be installed in all manner of light aircraft, either as a retrofit or in the construction of new aircraft. Claimed to reduce operating and maintenance bills, whilst lowering fuel consumption, the makers also assert that it may one day also be available for other types of craft, including gyroplanes, drones and UAVs.   Source: Universidad Carlos III de Madrid, AXTER Aerospace

Smart windows can be tuned for privacy, while still letting the light shine through

 

Imagine if you could turn up the opacity for a bit of privacy, just as you would with regular blinds, without compromising on brightness? (Credit: Timothy Zarki/University of Cincinnati) Image Gallery (9 images) The glass panels that let light into our homes and offices have been seen as huge windows of opportunity for engineers in recent times. If the amount of light pouring through can be managed throughout the day, it could lessen reliance on energy-sapping air conditioner units, for instance. This has led to a number of examples of smart facades that keep interior spaces from overheating, and some that even harvest energy for lights and ventilation. But a new tunable window-tinting technology is claimed to do things the smart glass before it cannot, by allowing users control over brightness, color temperature and opacity. Scientists from the University of Cincinnati (UC) teamed up with researchers from Hewlett Packard, Merck and National Taiwan University in developing the tunable windows. The team set out to produce an adaptation of the technology found in e-paper electronic displays that could scale to cover entire window panes without being prohibitively expensive. Around three years in the making, the final, patent-pending design is claimed to be simple and cheap to manufacture. Two glass substrates enclose a layer of polymer, a set of electrodes, and micro-replicated polymer nubs. This results in a honeycomb-pattern coating that can be integrated into new windows or even rolled onto existing ones. "Basically, one color has one charge," explains UC's Sayantika Mukherjee, who led the research. Another color has another charge, and we apply voltage to repel or attract the colors into different positions. The basic technology is not that different from what our group has previously demonstrated before in electronic display devices." So, imagine if you could turn up the opacity for a bit of privacy, just as you would with regular blinds, without compromising on brightness? Or adjust the windows to bring feelings of warmth to your cold, bare basement, like you could with one of Phillips' Hue lightbulbs? The researchers say the tunable windows can make this possible. They report that when the windows are turned milky for privacy, they are capable of still letting through 90 percent of natural light. Furthermore, the team says the system can allow for other types of configurations. This might involve controlling both visible light and infrared heat transmission at the same time. Such a function could find use in summer months to prevent the house heating up, or in the winter months to help keep it warm and toasty. The researchers are hopeful that the solution will lead to inexpensive window tinting that replaces conventional shades and blinds. The research was published in the journal Applied Optics.   Source: University of Cincinnati

New algorithm paves the way for light-based computers

 

Optical interconnects made of silicon act as a prism to direct infrared light transferring data between computer chips An inverse design algorithm developed by Stanford engineers enables the design of silicon interconnects capable of transmitting data between computer chips via light. The new process replaces the wire circuitry used to relay information electronically, which could lead to the development of highly efficient, light-based computers. While the heavy lifting in computer processing takes place inside the chips, an analysis by Stanford professor of electrical engineering, David Miller, showed that up to 80 percent of a microprocessor’s power is eaten up by the transmitting of data as a stream of electrons over wire interconnects. Basically, shipping requires far more energy than production, and chewing through all that power is the reason laptops heat up. Inspired by the optical technology of the internet, the researchers sought to move data between chips over fiber optic threads beaming photons of light. Besides using far less energy than traditional wire interconnects, chip-scale optic interconnects can carry more than 20 times more data. The majority of fiber optics are made from silicon, which is transparent to infrared light the same way glass is to visible light. Thus, using optical interconnects made from silicon was an obvious choice. “Silicon works,” said Tom Abate, Stanford Engineering communications director. “The whole industry knows how to work with silicon.” But optical interconnects need to be designed one at a time, making the switch to the technology impractical for computers since such a system requires thousands of such links. That’s where the inverse design algorithm comes in. The software provides the engineers with details on how the silicon structures need to be designed for performing tasks specific to their optical circuitry. The group designed a working optical circuit in the lab, copies were made, and all worked flawlessly despite being constructed on less than ideal equipment. The researchers cite this as proof of the commercial viability of their optical circuitry, since typical commercial fabrication plants use highly precise, state-of-the-art manufacturing equipment. While details of the algorithm’s functions is a tad complex, it basically works by designing silicon structures that are able to bend infrared light in various and useful ways, much like a prism bends visible light into a rainbow. When light is beamed at the silicon link, two wavelengths, or colors, of light split off at right angles in a T shape. Each silicon thread is miniscule – 20 could sit side-by-side within a human hair. The optical interconnects can be constructed to direct specific frequencies of infrared light to specific locations. And it’s the algorithm that instructs how to create these silicon prisms with just the right amount and bend of infrared light. Once the calculation is made as to the proper shape for each specific task, a tiny barcode pattern is etched onto a slice of silicon. Building an actual computer that uses the optical interconnects has yet to be realized, but the algorithm is a first big step. Other potential uses for the algorithm include designing compact microscopy systems, ultra-secure quantum communications, and high bandwidth optical communications. The team describes their work in the journal Nature Photonics. Source: Stanford University