Amazing Science

Unlike plastic, which stays in landfills for centuries, this bottle design will start bio-degrading immediately.

If you have ever tried to untangle a pair of earbuds, you’ll understand how loops and cords can get twisted up. DNA can get tangled in the same way, and in some cases, has to be cut and reconnected to resolve the knots. Now a team of mathematicians, biologists and computer scientists has unraveled how E. coli bacteria can unlink tangled DNA by a local reconnection process. The math behind the research, recently published in Scientific Reports, could have implications far beyond biology.

E. coli bacteria can cause intestinal disease, but they are also laboratory workhorses. E. coli’s genome is a single circle of double-stranded DNA. Before an E. coli cell divides, that circle is copied. Opening up the double helix to copy it throws twisting strains elsewhere down the molecule — just as uncoiling a cord in one place will make it over-coil somewhere else. The process results in two twisted loops of DNA that pass through each other like a “magic rings” trick.

To separate the rings, E. coli uses an enzyme called topoisomerase IV, which precisely cuts a DNA segment, allows the loops to pass through the break and then reseals the break. Because topoisomerase IV is so important to bacteria, it’s a tempting target for antibiotics such as ciprofloxacin. But when topoisomerase IV is absent, another enzyme complex can step in to carry out this unlinking, although less efficiently. This complex introduces two breaks and unlinks by reconnecting the four loose ends.

“There are other ways to unlink the rings, but how do they do it?” said Mariel Vazquez, professor of mathematics and of microbiology and molecular genetics at the University of California, Davis.

In Schrödinger's famous thought experiment, a cat seems to be both dead and alive—an idea that strains credulity. These days, cats still don't act this way, but physicists now regularly create analogues of Schrödinger's cat.

Such "cat states" have found many homes, promising more sensitive quantum measurements and acting as the basis for quantum error-correcting codes—a necessary component for future error-prone quantum computers. With these goals in mind, some researchers are eager to create better cat states with single ions. But, so far, standard techniques have imposed limits on how far their quantum nature could spread.

Recently, researchers at the Joint Quantum Institute developed a new scheme for creating single-ion cat states, detailing the results this week in Nature Communications. Their experiment places a single ytterbium ion into a superposition—a quantum combination—of two different states. Initially, these states move together in their common environment, sharing the same motion. But a series of carefully timed and ultrafast laser pulses apply different forces to the two ion states, pushing them in opposite directions. The original superposition persists, but the states end up oscillating out of phase with each other. 


Using this technique, the JQI team managed to separate the states by a distance of almost 300 nanometers, roughly twelve times further than previously possible. There's still just one ion, but its quantum nature now extends over a distance more than a thousand times larger than its original size. Such long-range superpositions are highly sensitive, and could enable precise atom interferometry measurements or robust quantum cryptographic techniques

More information: K. G. Johnson et al. Ultrafast creation of large Schrödinger cat states of an atom, Nature Communications (2017). DOI: 10.1038/s41467-017-00682-6

Microbots inspired by some of Earth’s littlest critters are powered not by limbs, but magnetic fields.

The beauty of evolution is that it is non-judgmental. What began as the first organism billions of years ago has diversified into species that fly and hop and run, whatever best suits them in their environment. As Charles Darwin put it, “from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” Look at the explosive field of robotics and you’ll actually find the same thing going on. The classic humanoid of sci-fi has diversified into bots that crawl on six legs, or walk on two (however cautiously), or even bound around on a single limb. And there are even microbots inspired by some of Earth’s littlest critters—powered not by limbs, but magnetic fields.

At SRI International in Silicon Valley, researchers have developed perhaps the most impressive microbot army yet: the MicroFactory. It’s an ant colony made robotic, with half-millimeter machines zipping around to construct truly impressive structures. It could well be a glimpse at a future where 3-D printers give way to swarms of robots that cooperatively build stronger, more complex structures.

The setup of the MicroFactory is fairly straightforward. The foundation is a circuit board that generates a magnetic field. The little robots themselves are magnets, which a software program drives around by manipulating the field. Each robot is outfitted with what’s known as an end effector—the tool with which it manipulates its world—which varies depending on the job the bot is assigned.

So say you want to build a lattice. You’ve got robots that hold high-strength carbon rods vertically and some that hold them horizontally, and still others that apply dabs of glue. Working in concert, the robots can build out an intricate structure, some depositing glue while others stick in the rods, constantly gliding from the lattice back to material caches to resupply.

Sure, you can use a 3-D printer to build complex structures without having to mess with a magnetic field. But the beauty of the MicroFactory is its diversity of materials. Rods and glue are just the start: The robots can also schlep components like resistors and LEDs to build out far more complicated projects with embedded electronics.

But we might also envision a day when microbots work alongside 3-D printers. The bots could build out a sturdy skeleton, for instance, while the printer lays down ornamental bits. “We can use this in conjunction with 3-D printing or we can supplant 3-D printing because we have a much wider range of materials that we can use,” says SRI principal engineer Annjoe Wong-Foy.

OIST researchers develop turbines to convert the power of ocean waves into clean, renewable energy.

Professor Tsumoru Shintake at the Okinawa Institute of Science and Technology Graduate University (OIST) yearns for a clean future, one that is affordable and powered by sustainable energy. Originally from the high-energy accelerator field, in 2012 he decided to seek new energy resources—wind and solar were being explored in depth, but he moved toward the sea instead.

That year, Professor Shintake and the Quantum Wave Microscopy Unit at OIST began a project titled “Sea Horse,” aiming to harness energy from the Kuroshio ocean current that flows from the eastern coast of Taiwan and around the southern parts of Japan. This project uses submerged turbines anchored to the sea floor through mooring cables that convert the kinetic energy of sustained natural currents in the Kuroshio into usable electricity, which is then delivered by cables to the land. The initial phase of the project was successful, and the Unit is now searching for industry partners to continue into the next phase. But the OIST researchers also desired an ocean energy source that was cheaper and easier to maintain.

This is where the vigor of the ocean’s waves at the shoreline comes into play. “Particularly in Japan, if you go around the beach you’ll find many tetrapods,” Professor Shintake explains. Tetrapods are concrete structures shaped somewhat like pyramids that are often placed along a coastline to weaken the force of incoming waves and protect the shore from erosion. Similarly, wave breakers are walls built in front of beaches for the same purpose. “Surprisingly, 30% of the seashore in mainland Japan is covered with tetrapods and wave breakers.” Replacing these with “intelligent” tetrapods and wave breakers, Shintake explains, with turbines attached to or near them, would both generate energy as well as help to protect the coasts.  

“Using just 1% of the seashore of mainland Japan can [generate] about 10 gigawats [of energy], which is equivalent to 10 nuclear power plants,” Professor Shintake explains. “That’s huge.”

Dubai has edged closer to its goal of launching a pioneering hover-taxi service, with the authorities announcing a successful "concept" flight was made on Monday without passengers.

Safety features for the two-seater air taxi include emergency parachutes and nine independent battery systems, according to Dubai's Road and Transport Authority (RTA). It said the prototype, supplied by Germany-based Volocopter, can fly for 30 minutes at a maximum speed of 100 kilometers per hour (62mph).

The RTA envisions that the hover-taxi will eventually be integrated into the city's existing public transport network, which includes a metro system, tramway and buses. Passengers would be able to book their "autonomous air taxi" and track its arrival and route using an app. Authorities anticipate five years of testing to put in place safety procedures and legislation governing the cutting-edge mode of transportation.

Home to Burj Khalifa, currently the world's tallest tower, Dubai is a leading tourist destination in the Gulf, attracting a record 14.9 million visitors last year.

A team of spider experts and students from the University of Vermont has discovered and described 15 new species of the spider genus Spintharus from the Caribbean region and other southern spots -- and named them after, among others, Bernie Sanders, Barack and Michelle Obama, David Attenborough, and Leonardo DiCaprio.

“In naming these spiders (Spintharus davidattenboroughi, S. barackobamai, S. michelleobamaae, and S. berniesandersi as well as S. davidbowiei and S. leonardodicaprioi), the students and I wanted to honor people who stood up for both human rights and warned about climate change — leaders and artists who promoted sensible approaches for a better world,” explained University of Vermont Professor Ingi Agnarsson.

“Until now, the beautiful yellow smiley-faced spiders in the genus Spintharus— named for a smiley face pattern on their abdomens — has been thought to have one widespread species from northern North America down to northern Brazil.”

“However, when we examined spiders from Jamaica, Cuba, the Dominican Republic, Puerto Rico, the Lesser Antilles, Florida, South Carolina, Costa Rica, Mexico, and Colombia, we discovered that one widespread species was actually many endemic species.”

The GoFly Prize, sponsored by Chicago-based company Boeing, is a competition to create a personal flying device (a jetpack) that can be safely used by anyone.

Sponsored by Boeing and run by start-up GoFly, the competition will encourage teams from around the world to come up with designs. Entries must be capable of carrying a person 20 miles without refueling or recharging, with a vertical or near vertical take-off and landing. A "fly-off" will take place in 2019.

GoFly founder Gwen Lighter told the BBC: "I was one of those kids who was always making crazy contraptions and throwing themselves out of trees. "I, like millions of people around the globe, always dreamed of flying, and I began to realise that we were seeing a moment of convergence of technologies and were at a point in history when these personal flight devices become possible."

For the purpose of the research, Mor Taub and Yosef Prat, students in Prof. Yovel’s lab, recorded the sounds emitted by 22 Egyptian fruit bats in TAU’s “bat cave” over the course of 75 days. The authors then assembled a dataset of approximately 15,000 vocalizations, which represented the full vocal repertoire the bats used during the experiment. By analyzing this dataset, the authors found that the vocalizations contained information about the identity of the bat emitting the call and even about the identity of the bat being addressed by the call. Moreover, while most of this species’ vocalizations were emitted during aggressive encounters, by analyzing the spectral composition of the calls, the authors were also able to distinguish their specific aggressive context (such as squabbling over food, sleeping spots or other resources).

“Studying how much information is conveyed in animal communication is important if you’re interested in the evolution of human language,” said Prof. Yovel. “Specifically, one big unknown in the world of animal communication is their grasp on semanticity — i.e., when you hear the word ‘apple’ you immediately imagine a round, red fruit. We found, in our research, that bat calls contain information about the identities of the caller and the addressee, which implies that there is a recognition factor. We were also able to discern the purpose and the context of the conversation, as well as the possible outcome of the ‘discussion.'”

Due to the difficulty of cataloguing animal calls, these vocalizations are often grouped into one category in acoustic studies. According to Prof. Yovel, the new findings suggest that delving into animal calls could serve a bigger purpose, shedding light on the evolution of communication altogether.

“We generated a massive amount of data — dozens of calls over three months,” said Prof. Yovel. “We have found that bats fight over sleeping positions, over mating, over food or just for the sake of fighting. To our surprise, we were able to differentiate between all of these contexts in complete darkness, and we are confident bats themselves are able to identify even more information and with greater accuracy — they are, after all, an extremely social species that live with the same neighbors for dozens of years.”

The researchers were even able to identify different intonations indicating the greetings of a “friend” or a “foe.”

Silicon neurons might make machines like cars and robots smarter and more independent.

If you are asked to guess the emotion of someone in a video clip, neurons in your brain will exchange information in a flurry of electronic spikes. When researchers at Intel recently put a similar challenge to the prototype of their new chip, Loihi, it tried to solve the problem with thousands of spiking silicon “neurons” of its own. Like your neurons, they can adjust the connections between themselves to adapt to new tasks.

Intel’s new design, named after a submarine volcano in Hawaii, still isn’t much like a real brain. But it’s very different from a conventional processor. The company says this approach could one day make cars, cameras, and robots smarter without having to rely on an internet connection to the cloud. Cutting the cord removes the need to wait for data to traverse the internet and has privacy benefits.

Intel says tests indicate its brain-inspired, or neuromorphic, design can do things like interpret video using as little as one-thousandth of the energy of a conventional chip. That, and Loihi’s ability to learn as it encounters new data, are seen as pointing to a future where machines can better hold their own in the always-changing real world. “We’re trying to get better at understanding things that are happening in a natural environment,” says Michael Mayberry, managing director of Intel’s research arm.

Loihi is still a research project. But Mayberry says the first full version of the chip, with 130,000 neurons and the size of a pinkie fingernail, will be fabricated in November. Some academic and research institutions will get to try it in 2018. Intel has made two smaller prototypes, and is now testing the full design. Mayberry estimates that if Loihi sparks interest, it would take two years or more to get to market.

Loihi is Intel’s latest effort to turn the current vogue for AI into a new growth engine for the company. Last year Intel acquired two startups working on chips to power machine learning in the cloud and for computer vision, Nervana and Movidius. This March, Intel bought Israel’s Mobileye, which makes cameras and chips for automated driving.

Intel needs new growth businesses. The PC market it has long dominated is stalling, and the company has given up on breaking into the market for processors inside mobile devices. The AI startups Intel acquired created chips to accelerate artificial neural networks. The technique underpins advances such as Google’s Go champion bot AlphaGo, and involves loosely simulating neurons that work together to filter data. But Intel’s existing technology—and that in AI chips from Google, Microsoft, and Apple—powers neural networks using conventional chip designs.

A new King's College London study reveals the molecular basis of chronic nerve pain in diabetes. The findings in mice, published today in Science Translational Medicine, could one day lead to treatments which target the source of the pain.

Around one in four people with diabetes develop a chronic pain condition induced by nerve damage, called painful diabetic neuropathy (PDN), due tohigh blood sugar. Symptoms include prickling and tingling sensations as well as sharp, shooting pains and extreme sensitivity to touch in the feet and hands, which can spread upward into the legs and arms. The pain can significantly impair mobility, which in turn exacerbates obesity and worsens type 2 diabetes in a self-perpetuating cycle.

Diabetic pain is very difficult to treat and the molecular causes are poorly understood. This new King's College London study provides the first evidence that a single protein molecule - HCN2 - can by itself be responsible for a complex sensation such as diabetic pain.

The researchers used mouse models of diabetes to show that over-activity of HCN2, which initiates electrical signals in pain-sensitive nerve fibers, results in a sensation of pain. They also found that blocking the activity of HCN2, or removing it completely from pain-sensitive nerve fibers, stopped the sensation of pain entirely.

Professor Peter McNaughton, senior author of the study, from the Wolfson Centre for Age-Related Diseases at King's College London, said: "The inexorable rise of obesity worldwide, in both rich and poorer countries, has brought a related increase in type 2 diabetes. As many as one in four diabetics suffer from nerve pain, yet there are currently no effective treatments and people therefore typically must resign themselves to a life of continuous suffering.

For the first time, researchers have sent a quantum-secured message containing more than one bit of information per photon through the air above a city. The demonstration showed that it could one day be practical to use high-capacity, free-space quantum communication to create a highly secure link between ground-based networks and satellites, a requirement for creating a global quantum encryption network.
 
Quantum encryption uses photons to encode information in the form of quantum bits. In its simplest form, known as 2D encryption, each photon encodes one bit: either a one or a zero. Scientists have shown that a single photon can encode even more information — a concept known as high-dimensional quantum encryption — but until now this has never been demonstrated with free-space optical communication in real-world conditions. With eight bits necessary to encode just one letter, for example, packing more information into each photon would significantly speed up data transmission.
 
“Our work is the first to send messages in a secure manner using high-dimensional quantum encryption in realistic city conditions, including turbulence,” said research team lead, Ebrahim Karimi, University of Ottawa, Canada. “The secure, free-space communication scheme we demonstrated could potentially link Earth with satellites, securely connect places where it is too expensive to install fiber, or be used for encrypted communication with a moving object, such as an airplane.”

An international team of astronomers, led by academics from the University of Central Lancashire (UCLan), has found the largest known structure in the universe. The large quasar group (LQG) is so large that it would take a vehicle traveling at the speed of light some 4 billion years to cross it. The team publish their results in the journal Monthly Notices of the Royal Astronomical Society.

Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances. These periods are 'brief' in astrophysics terms but actually last 10-100 million years.

Since 1982 it has been known that quasars tend to group together in clumps or 'structures' of surprisingly large sizes, forming large quasar groups or LQGs.

Scientists at Amherst College (USA) and Aalto University (Finland) have made the first experimental observations of the dynamics of isolated monopoles in quantum matter.

The new study provided a surprise: the quantum monopole decays into another analogue of the magnetic monopole. The obtained fundamental understanding of monopole dynamics may help in the future to build even closer analogues of the magnetic monopoles.

Unlike usual magnets, magnetic monopoles are elementary particles that have only a south or a north magnetic pole, but not both. They have been theoretically predicted to exist, but no convincing experimental observations have been reported. Thus physicists are busy looking for analogue objects.

Whereas the Dirac monopole experiment simulates the motion of a charged particle in the vicinity of a monopolar magnetic field, the quantum monopole has a point-like structure in its own field resembling that of the magnetic monopole particle itself.

Berkeley Lab scientists used nanoparticle surfactants to create a new type of “bijel,' a material that holds promise as a malleable liquid with applications in liquid circuitry, energy conversion, and soft robotics.

A new two-dimensional film, made of polymers and nanoparticles and developed by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), can direct two different non-mixing liquids into a variety of exotic architectures. This finding could lead to soft robotics, liquid circuitry, shape-shifting fluids, and a host of new materials that use soft, rather than solid, substances.

The study, reported today in the journalNature Nanotechnology, presents the newest entry in a class of substances known as bicontinuous jammed emulsion gels, or bijels, which hold promise as a malleable liquid that can support catalytic reactions, electrical conductivity, and energy conversion.

Bijels are typically made of immiscible, or non-mixing, liquids. People who shake their bottle of vinaigrette before pouring the dressing on their salad are familiar with such liquids. As soon as the shaking stops, the liquids start to separate again, with the lower density liquid – often oil – rising to the top.

Trapping, or jamming, particles where these immiscible liquids meet can prevent the liquids from completely separating, stabilizing the substance into a bijel. What makes bijels remarkable is that, rather than just making the spherical droplets that we normally see when we try to mix oil and water, the particles at the interface shape the liquids into complex networks of interconnected fluid channels.

Bijels are notoriously difficult to make, however, involving exact temperatures at precisely timed stages. In addition, the liquid channels are normally more than 5 micrometers across, making them too large to be useful in energy conversion and catalysis.

“Bijels have long been of interest as next-generation materials for energy applications and chemical synthesis,” said study lead author Caili Huang. “The problem has been making enough of them, and with features of the right size. In this work, we crack that problem.”

Huang started the work as a graduate student with Thomas Russell, the study’s principal investigator, at Berkeley Lab’s Materials Sciences Division, and he continued the project as a postdoctoral researcher at DOE’s Oak Ridge National Laboratory.