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Gut Microbes Can Split a Species

Gut Microbes Can Split a Species | green technology | Scoop.it

Here's how to create a new species. Put animals—say finches—from the same species on separate islands and let them do their thing for many, many generations. Over time, each group will adapt to its new environment, and the genomes of the two populations will become so different that if you reintroduce the animals to the same habitat, they can no longer breed successfully. Voilà, one species has become two. But a new study suggests that DNA isn't the only thing that separates species: Some populations diverge because of the microbes in their guts.

 

The paper is "important and potentially groundbreaking," says John Werren, a biologist at the University of Rochester in New York. "Scientists have studied speciation … for many years, and this opens up a whole new aspect to it."

 

The new work involves three different species of parasitic jewel wasps, tiny insects that drill into the pupas of flies and lay their eggs, letting the offspring feed on the host. Two of the species, Nasonia giraulti and N. longicornis, are closely related, whereas the third species, N. vitripennis, diverged from the other two about 1 million years ago. When N. giraulti and N. longicornis mate in the lab, most of their offspring survive, but when either mates with N. vitripennis, almost all male larvae in the second generation die.

 

Seth Bordenstein and Robert Brucker, biologists at Vanderbilt University in Nashville, wondered if the reason for this mortality went beyond incompatible DNA. They knew that the gut microbes in N. vitripennisdiffered from those in the other two species, and they suspected that these microbes could play a role in the offspring deaths.

 

Indeed, when they raised all three species of Nasonia without gut microbes—by rearing them on sterile food—almost all the second generation offspring of matings between N. vitripennis and N. giraulti wasps survived. And when the scientists reintroduced bacteria into the germ-free wasps, most of their second-generation offspring died, the duo report.

 

Werren says that the work introduces a whole new way to look at what sets species apart. Instead of just thinking about genes of the parents not meshing in hybrids, he says, biologists could now think about how the parents' genes are incompatible with the offspring's microorganisms. Some parental genes could enable the immune system to keep certain gut bacteria in check, for instance, and without them the gut microbes might sicken the animal and kill it.


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Are plants more intelligent than we assumed? They can abort their own seeds to prevent parasite infestation

Are plants more intelligent than we assumed? They can abort their own seeds to prevent parasite infestation | green technology | Scoop.it

Plants are also able to make complex decisions. At least this is what scientists have concluded from their investigations on Barberry (Berberis vulgaris), which is able to abort its own seeds to prevent parasite infestation. Approximately 2000 berries were collected during this study from different regions of Germany, examined for signs of piercing and then cut open to examine any infestation by the larvae of the tephritid fruit fly (Rhagoletis meigenii). 


This parasite punctures the berries in order to lay its eggs inside them. If the larva is able to develop, it will often feed on all of the seeds in the berry. A special characteristic of the Barberry is that each berry usually has two seeds and that the plant is able to stop the development of its seeds in order to save its resources. This mechanism is also employed to defend it from the tephritid fruit fly. If a seed is infested with the parasite, later on the developing larva will feed on both seeds. If however the plant aborts the infested seed, then the parasite in that seed will also die and the second seed in the berry is saved.

 

When analysing the seeds, the scientists came across a surprising discovery: "the seeds of the infested fruits are not always aborted, but rather it depends on how many seeds there are in the berries", explains Dr. Katrin M. Meyer, who analysed the data at the UFZ and currently works at the University of Goettingen. If the infested fruit contains two seeds, then in 75 per cent of cases, the plants will abort the infested seeds, in order to save the second intact seed. If however the infested fruit only contains one seed, then the plant will only abort the infested seed in 5 per cent of cases. The data from fieldwork were put into a computer model which resulted in a conclusive picture.

 

Using computer model calculations, scientists were able to demonstrate how those plants subjected to stress from parasite infestation reacted very differently from those without stress. "If the Barberry aborts a fruit with only one infested seed, then the entire fruit would be lost. Instead it appears to 'speculate' that the larva could die naturally, which is a possibility. Slight chances are better than none at all", explains Dr. Hans-Hermann Thulke from the UFZ. "This anticipative behaviour, whereby anticipated losses and outer conditions are weighed up, very much surprised us. The message of our study is therefore that plant intelligence is entering the realms of ecological possibility."

 

But how does the Barberry know what is in store for it after the tephritid fruit fly has punctured a berry? It is still unclear as to how the plant processes information and how this complex behaviour was able to develop over the course of evolution. The Oregon grape that is closely related to the Barberry has been living in Europe for some 200 years with the risk of being infested by the tephritid fruit fly and yet it has not developed any such comparable defence strategy. These new insights shed some light on the underestimated abilities of plants, while at the same time bringing up many new questions.


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Germany: Former war bunker transformed into green energy power plant

Germany: Former war bunker transformed into green energy power plant | green technology | Scoop.it

Energy and utilities company Hamburg Energie has joined forces with IBA Hamburg to transform a former Nazi anti-aircraft flak bunker into a green energy power plant. The Hamburg-based "Energy Bunker" has already begun producing energy for the local community, but once running at full capacity will provide up to 3,000 homes with heating, and another 1,000 homes with electricity.


Originally constructed in 1943 to serve as an anti-aircraft bunker, complete with gun turrets, the 42 m (137 ft) -high building also sheltered local people from Allied bombing raids during WWII. Though the British Army made an attempt to demolish the building on the war's close, blowing up its massively thick walls was deemed too dangerous to nearby buildings. The British ultimately settled on destroying much of the interior, and the bunker remained in this neglected state for over 60 years.


The Energy Bunker is outfitted with several sustainable technologies. The main feature is a 2 million liter (528,000 US gallon) water reservoir that acts as a large heat store and plugs into the existing Reiherstieg district heating network. The reservoir itself is heated by several methods: a biomass power plant and wood chip burning unit which feed into a large boiler, a solar thermal array installed on the roof of the bunker, and waste heat produced by a nearby industrial plant.

 

A large photovoltaic system is installed on the south-facing facade of the building to produce electricity, and the wood chip burning unit is also used to produce electricity. A peak-load boiler and large battery array ensure that the energy output is kept steady at all times.



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Lockheed Martin joins the world's largest wave-energy development project

Lockheed Martin joins the world's largest wave-energy development project | green technology | Scoop.it

Lockheed Martin has joined a partnership to develop what it described as “the world’s largest wave energy project” to date, off the Victoria coast in southern Australia. Victorian Wave Partners Ltd. is an Australian special-purpose company owned by Ocean Power Technologies Australasia Pty Ltd., a developer of “wave energy” technology.

 

OPT’s PowerBuoy system uses a "smart" buoy to convert wave energy into electricity.  The buoy moves up and down with the rising and falling of waves, and the mechanical energy generated by this action drives an electrical generator, which transmits power to shore via an underwater cable.

 

The system is designed to be electrically tuned on a wave-by-wave basis to maximize the amount of electricity produced. In the Australian development, anticipated peak-power generating capacity is 62.5 megawatts. That would be sufficient to supply 10,000 homes.

The Victorian Wave project is scheduled to be built in three stages, with the first stage producing approximately 2.5 megawatts of peak power.

No starting date has been indicated for the installation.

 

Lockheed did not reveal the value of its investment.  It will provide overall project management, assist with the design for manufacturing the PowerBuoy systems, lead the production of selected components, and perform system integration of the wave energy converters.

 

Lockheed Martin’s participation in this project is reminiscent of Boeing’s recent participation in a tidal-energy project, though wave power is distinct from tidal power.

 

Wave power devices extract energy from the surface motion of ocean waves, which is very predictable and reportedly will generate electricity for more hours in a year than wind and solar sources.

 

"We are applying our design and system integration expertise to commercialize promising, emerging alternative energy technologies, including ocean power," stated Tim Fuhr, director of ocean energy for Lockheed Martin's Mission Systems and Training business. "This project extends our established relationship with OPT and Australian industry, and enables us to demonstrate a clean, efficient energy source for Australia and the world."


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Quarks Know Their Left From Their Right

Quarks Know Their Left From Their Right | green technology | Scoop.it

Matter interacts through four fundamental forces: the electromagnetic force that creates light and chemical bonds, the strong nuclear force that binds quarks and nuclei, the weak nuclear force that produces a type of radioactive decay called beta decay, and gravity. There could be other forces – some theorists have speculated that a second version of the weak force may also exist. At one time, physicists assumed that all the forces obeyed a handful of symmetries. So, for example, a physical system should behave exactly like its mirror image, a symmetry known as parity.

 

In 1957, physicists discovered that parity does not hold in particle interactions mediated by the weak force. For example, suppose you aim right-spinning electrons at nuclei and watch them bounce off. If you look at the tiny shooting gallery in a mirror, you'll see left-spinning electrons bouncing off the target. So if the interaction between electron and nucleus were mirror-symmetric, then the scattering of right- and left-spinning electrons should be the same. And, indeed, that’s exactly what would happen if the negatively charged electrons interacted with the positively charged nuclei only through the electromagnetic force.


But the electrons also interact with the nuclei through the weak force, which violates parity and is not mirror symmetric. As a result, right-spinning and left-spinning electrons ricochet off the target differently, creating a slight asymmetry in their scattering pattern. That effect was seen at SLAC National Accelerator Laboratory in Menlo Park, California, in 1978 in an experiment called E122 that helped cement physicists' then-emerging standard model. A second weak force, if it exists, ought to give similarly lopsided results.


But what about the quarks? Like electrons, they can spin one way or the other as they zip around inside protons and neutrons. And, according to the standard model, the right- and left-spinning quarks should interact slightly differently with an incoming electron, producing an additional asymmetry, or parity violation, when the spin of the incoming electrons is flipped. Now, Xiaochao Zheng, a nuclear physicist at the University of Virginia in Charlottesville, and colleagues have observed that smaller contribution, as they recently reported in Nature.

 

That was no mean feat. To see the extra asymmetry, the incoming electron must strike the nucleus hard enough to blast out a single quark, setting off a shower of particles, as was done in E122 but not in subsequent experiments. Researchers must take great care to ensure that they alternately shine equally intense beams of right- and left-spinning electrons on the target. Using the electron accelerator at Thomas Jefferson National Accelerator Facility in Newport News, Virginia, the researchers shined 170 billion electrons on a target of liquid deuterium over 2 months in 2009. After crunching the data, they were able to measure the part-in-10,000 scattering asymmetry precisely enough to pull out the contribution from the quarks, albeit with a large uncertainty. The result agrees with the standard model prediction.

 

"They've measured something fundamental at the quark level that wasn't measured before," says William Marciano, a theorist at Brookhaven National Laboratory in Upton, New York. Maas notes that the result is not as exciting as it could have been, however. "They have not observed any new physics at the level of their precision," he says. The new result does place tighter limits on models that assume a second weak force exists, Maas says.

 

The measurement is not the end of the road. The 101 members in the experimental team intend to repeat their measurement and hope to improve their precision by at least a factor of 5, Zheng says. That should enable them to test for new forces with far more sensitivity, she says. Marciano agrees that "this is just the first step." He notes that it might be beneficial that the asymmetry from the quarks is so small in the standard model, as that will make any deviation look relatively large.


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Steering by peeking: Physicists control quantum particles by looking at them

Steering by peeking: Physicists control quantum particles by looking at them | green technology | Scoop.it

Scientists from the FOM Foundation and Delft University of Technology have manipulated a quantum particle, merely by looking at it in a smart way. By adjusting the strength of their measurement according to earlier measurement outcomes, they managed to steer the particle towards a desired state.

 

In earlier work the group showed that it is possible to measure the orientation of a single spin, in analogy to fully opening Schrödinger's box. To partially open the box, the scientists used a trick. Instead of directly measuring the nucleus, they first coupled the state of the nucleus to a nearby electron. They then determined the state of the electron.

By varying the strength of the coupling between the nucleus and the electron, the scientists could carefully tune the measurement strength. A weaker measurement reveals less information, but also has less back-action. An analysis of the nuclear spin after such a weak measurement showed that the nuclear spin remained in a (slightly altered) superposition of two states. In this way, the scientists verified that the change of the state (induced by the back-action) precisely matched the amount of information that was gained by the measurement.

The scientists realised that it is possible to steer the nuclear spin by applying sequential measurements with varying measurement strength. Since the outcome of a measurement is not known in advance, the researchers implemented a feedback loop in the experiment. They chose the strength of the second measurement depending on the outcome of the first measurement. In this way the scientists could steer the nucleus towards a desired superposition state by only looking at it.

 

This result provides new insight in the role of measurements in quantum mechanics. Furthermore the combination of measurements and feedback, as demonstrated here, form an essential building block for the future quantum computer. Finally, these techniques can increase the sensitivity of magnetic field sensors.


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Zeolite–polymer composite adsorbs uremic toxins

Zeolite–polymer composite adsorbs uremic toxins | green technology | Scoop.it

Scientists in Japan have developed a nanofiber mesh that can adsorb creatinine from blood with the hope that it can eventually be developed into a wearable blood-cleaning device for patients with kidney failure.


Kidney failure causes dangerous concentrations of waste products, such as potassium, urea and creatinine, to build-up in the body. Apart from having a kidney transplant, the next best solution for patients is dialysis. Dialysis, however, is far from ideal. It is time-consuming and relies on access to specialist equipment, clean water, electricity, dialysate, and, usually, a hospital. Often these requirements aren’t accessible in rural parts of developing countries and disaster areas.

 

Dialysis works according to the principles of diffusion, but Mitsuhiro Ebara and his team at the National Institute of Materials Science in Ibaraki have taken a different approach and developed a material that cleans blood by adsorption.

 

Zeolites are adsorbent minerals commonly used in water purification technologies. Different zeolites have different pore sizes meaning they can be used to selectively adsorb specific solutes. Ebara’s group trapped a zeolite into a composite mesh by electrospinning it with the biocompatible polymer, poly(ethylene-co-vinylalcohol) (EVOH), to prevent the zeolite from being released into the bloodstream. They then tested the ability of the composite mesh to adsorb creatinine from solution. The team had worried that the properties of EVOH would disable the adsorption properties of the zeolite, but instead they found the adsorption capacity of the mesh was 67% of the free zeolites.

 

The greatest challenge was precisely controlling the crystallinity of the polymer-zeolite fibers so that they were both insoluble and hydrophilic, says Ebara. ‘The fibers have to be hydrophilic so that the uremic toxin could access the embedded zeolites, but hydrophilic fibers are not stable in water.’

 

Ebara’s team calculated that a 16g mesh is enough to remove all the creatinine produced in one day by the human body. They are now designing a wrist-watch sized device that can be connected to the shunt that hemodialysis patients generally have inserted under their skin, as a more accessible and cheap alternative to dialysis treatment.



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Zircon crystal found on an Australian sheep ranch is the oldest known piece of our planet

Zircon crystal found on an Australian sheep ranch is the oldest known piece of our planet | green technology | Scoop.it
Scientists have shown that a tiny zircon crystal found on a sheep ranch in western Australia is the oldest known piece of our planet, dating to 4.4 billion years ago.

 

John Valley, a University of Wisconsin geoscience professor who led the research, said the findings suggest that the early Earth was not as harsh a place as many scientists have thought.

To determine the age of the zircon fragment, the scientists first used a widely accepted dating technique based on determining the radioactive decay of uranium to lead in a mineral sample.

 

But because some scientists hypothesised that this technique might give a false date due to possible movement of lead atoms within the crystal over time, the researchers turned to a second sophisticated method to verify the finding.


They used a technique known as atom-probe tomography that was able to identify individual atoms of lead in the crystal and determine their mass, and confirmed that the zircon was indeed 4.4 billion years old.

 

To put that age in perspective, the Earth itself formed 4.5 billion years ago as a ball of molten rock, meaning that its crust formed relatively soon thereafter, 100 million years later. The age of the crystal also means that the crust appeared just 160 million years after the very formation of the solar system.

 

The finding supports the notion of a "cool early Earth" where temperatures were low enough to sustain oceans, and perhaps life, earlier than previously thought, Professor Valley said.

 

This period of Earth history is known as the Hadean eon, named for ancient Greek god of the underworld Hades because of hellish conditions including meteorite bombardment and an initially molten surface.

 

"One of the things that we're really interested in is: when did the Earth first become habitable for life? When did it cool off enough that life might have emerged?" Professor Valley said.

 

The discovery that the zircon crystal, and thereby the formation of the crust, dates from 4.4 billion years ago suggests that the planet was perhaps capable of sustaining microbial life 4.3 billion years ago, Valley said.


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Psychobiotics: Can Gut Bacteria Change Your Brain?

Psychobiotics: Can Gut Bacteria Change Your Brain? | green technology | Scoop.it
Are psychobiotics the new anti-depressants? A new review article links probiotics to changes in mood and mental health, suggesting these "good" bacteria might have potential as a treatment for depression and other psychiatric maladies.

 

A new review article links probiotics to changes in mood and mental health, suggesting these “good” bacteria might have potential as a treatment for depression and other psychiatric maladies. In the study, published in the journal Biological Psychiatry, researchers define the term “psychobiotic” as “a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness.”

 

These organisms act on what researchers call the “brain-gut axis,” a biological network connecting the intestinal and endocrine systems to the spinal cord and regions in the brain that process stress, such as the HPA-axis.

 

Is all this plausible? Perhaps. Ghrelin, known as the “hunger hormone” and produced in the intestines, was recently found to play a role in the development of chronic stress. And stress in turn has been found to alter our microbiota. There’s growing evidence that there’s a special connection between the gut and the brain, and as one MGH psychiatrist said recently: “There is a neural feedback from the gut to the brain so chronic gastrointestinal distress can exacerbate anxiety or depression.”

 

Thomas Insel, Director of the National Institute of Mental Health, stated last December that how “differences in our microbial world influence the development of brain and behavior will be one of the great frontiers of clinical neuroscience in the next decade.”


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Scientists re-weigh the electron, get more precise mass

Scientists re-weigh the electron, get more precise mass | green technology | Scoop.it

A precise value for the mass of the electron is one example of the sort of statistic that physicists are eager to collect. Last Wednesday in Nature (2014. DOI: 10.1038/nature13026), a team of German physicists reported a new electron-mass measurement that offers a precision to parts per trillion. It is a “remarkable 13-fold increase in precision,” according to Florida State University physicist Edmund G. Myers, who published an accompanying perspective on the research paper.

 

Scientists have been on a quest for a better and better value of the tiny particle's size for decades. The goal with each new measurement is to get closer and closer to the true value of me, which sharpens our understanding of the way that atoms form molecules and is key to a variety of important calculations.

 

How do you measure something so small? Bind an electron to a reference ion—the team used the “hydrogen-like” carbon nucleus, stripped down to a single electron. The nucleus of that ion has a known, precise mass. You then pop it into an apparatus called a Penning trap, which has been in vogue since the 1980s. A magnetic field whips the ion around a circular path, while an electric field keeps it secured in this motion. Measure the frequency of the whole nucleus-electron system, then the frequency of just the electron. The mass of the electron can be calculated using this ratio, the mass of the ion, the ratio of the electron’s charge to that of the ion, and one other factor: the “g-factor.”

 

Most recent advances in understanding the electron's mass have been thanks to better and better predictions of the g-factor. (Two decades ago, scientists last published an electron mass measurement based on a direct cyclotron measurement described above.) The g-factor is a dimensionless number that is crucial in calculating the frequency of the electron spinning around in the Penningtrap. A “state of the art QED calculation” was used to pin down the g-factor of an electron tethered to a carbon nucleus.

 

Electrons underlie our physical world—everything we interact with is, in part, made of them—as well as our mathematical interpretations of it. The value of their mass is a crucial parameter in the Standard Model of particle physics, which explains electromagnetism, as well as the weak and strong nuclear interactions. The mass of the electron contributes to other key values, such as the Rydberg constant and the fine-structure constant.


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Joy Kinley's curator insight, February 26, 2014 11:13 AM

The masses of protons and neutrons are small and electrons are a fraction of the mass of protons and neutrons.  Any time we can get precise measurements it helps our understanding.

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Mysterious Quantum 'Dropletons' Form Inside Semiconductors Shot With Lasers

Mysterious Quantum 'Dropletons' Form Inside Semiconductors Shot With Lasers | green technology | Scoop.it

By peering into a semiconductor with ultra-fast laser pulses, scientists have discovered a new quasiparticle that behaves like a drop of liquid. They call it a quantum droplet, or dropleton.

 

These things were not predicted under any theory and surprised scientists when they appeared unexpectedly in extremely low temperature semiconductor experiments. They have properties unlike anything seen before. “At first we scratched our heads,” said physicist Steven Cundiff of the University of Colorado and National Institute of Standards and Technology in Boulder, one of the authors of a paper appearing today in Nature. “But then we came up with this idea that what we were seeing was this new thing we’re calling a quantum droplet.”

 

There are materials, such as metals, that are good conductors of electricity. Inside of a conductor like copper wire are countless copper atoms arranged in a lattice. The electrons of the copper atoms become unbound from their nuclei and are free to flow, allowing them to easily carry a current. The opposite of this is an insulator, like rubber, in which electrons stay put. Sitting between these two extremes are materials like silicon semiconductors, in which some of the electrons can freely move and conduct electricity, while others are stuck. Pure silicon is actually not a good semiconductor because all of its atoms are covalently bonded to their neighbors. The electrons spend all their time stuck being shared between the atomic nuclei and can’t flow. But introducing impurities that take the place of some of the silicon atoms can free up some of the electrons, creating a semiconductor.


When a photon comes into a silicon semiconductor, it hits one of the atomic nuclei, kicking free an electron. Left behind is one type of quasiparticle known as an electron hole. The electron hole is sort of like an empty bubble situated within all the other electrons of all the other atomic nuclei in the silicon lattice. In the same way that an air bubble in a cup of water will rise while all the other water drops tend to fall, the electron hole behaves the opposite of an electron. When describing it using the equations of quantum mechanics, the hole even has a positive charge, compared to the electron’s negative charge.

 

If there’s anything you probably already know about charges, it’s that opposites attract. One electron and one hole can come together and create a quasiparticle known as an exciton. From a quantum mechanical point of view, the hole has properties similar to a proton. In this way, the exciton behaves like a neutral hydrogen atom, in which an electron and proton are bound together. What Cundiff’s team did was cool a gallium-arsenide semiconductor down to that temperature and shoot it with a laser. The laser photons generated free electrons, holes, and eventually excitons inside their semiconductor (all on extremely short timescales of a few trillionths of a second). As the researchers increased the intensity of the laser, it created more and more excitons. But so many excitons start to interfere with one another, and this weakens the bonds between their electrons and holes. At a certain laser intensity, excitons can no longer form.


Next, the team shifted the wavelength of the laser down a little and then shot it at the gallium arsenide. Now, the laser pulses created electrons, holes, and excitons. But the excitons could also come together into quasiparticles called a biexcitons, made of two excitons. In the same way that excitons are analogous to a hydrogen atom, a biexciton is like a hydrogen molecule, H2. The researchers also expected that the binds between these biexcitons would weaken as they increased their laser’s intensity. 

 

The biexcitons actually became more strongly bound, seeming to form a completely new configuration of four electrons and holes. The experiments also created quasiparticles of five electrons and holes, and six electrons and holes. “We were puzzled,” said Cundiff. “Hydrogen atoms don’t do this.”

 

After checking with some mathematical models, they realized they had discovered something completely new. In the exciton, the electrons and holes were forming something like hydrogen atoms. And then in biexciton, the excitons were regularly spaced apart from one another, just like atoms in a molecule. But in this new quasiparticle, the electrons and holes no longer had a fixed position relative to one another. Instead, they jostled like a small drop of liquid, hence the name dropleton.

 

By performing different control experiments, the team was able to eliminate the possibility that what they were seeing corresponded to any other known quasiparticles, says chemist Daniel Turner of New York University, who was not involved with this work. “Out of this complicated goo of electrons and holes, they’re able to distinguish a new phenomenon,” said Turner.


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Superconducting 3-inch disk can levitate something 70,000 times its own weight

Superconducting 3-inch disk can levitate something 70,000 times its own weight | green technology | Scoop.it
How can a super-thin 3-inch disk levitate something 70,000 times its own weight? In a riveting demonstration, Boaz Almog shows how a phenomenon known as quantum locking allows a superconductor disk to float over a magnetic rail -- completely frictionlessly and with zero energy loss. Experiment: Prof. Guy Deutscher, Mishael Azoulay, Boaz Almog, of the High Tc Superconductivity Group, School of Physics and Astronomy, Tel Aviv University.

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Harvard physicists propose a device to capture energy from Earth's infrared emissions to outer space

Harvard physicists propose a device to capture energy from Earth's infrared emissions to outer space | green technology | Scoop.it
(Phys.org) —When the sun sets on a remote desert outpost and solar panels shut down, what energy source will provide power through the night? A battery, perhaps, or an old diesel generator? Perhaps something strange and new.

 

Physicists at the Harvard School of Engineering and Applied Sciences (SEAS) envision a device that would harvest energy from Earth's infrared emissions into outer space.

 

Heated by the sun, our planet is warm compared to the frigid vacuum beyond. Thanks to recent technological advances, the researchers say, that heat imbalance could soon be transformed into direct-current (DC) power, taking advantage of a vast and untapped energy source.

 

Their analysis of the thermodynamics, practical concerns, and technological requirements will be published this week in the Proceedings of the National Academy of Sciences.

 

"It's not at all obvious, at first, how you would generate DC power by emitting infrared light in free space toward the cold," says principal investigator Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at Harvard SEAS. "To generate power by emitting, not by absorbing light, that's weird. It makes sense physically once you think about it, but it's highly counterintuitive. We're talking about the use of physics at the nanoscale for a completely new application."


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Scientists Say Their Giant Laser Has For The First Time Produced Nuclear Fusion

Scientists Say Their Giant Laser Has For The First Time Produced Nuclear Fusion | green technology | Scoop.it

Researchers at a laboratory in California say they've had a breakthrough in producing fusion power with a giant laser. The success comes after years of struggling to get the laser to work, and is another step in the decades-long quest for fusion energy. Omar Hurricane, a researcher at Lawrence Livermore National Laboratory, says that for the first time, they've produced significant amounts of fusion by zapping a target with their laser. "We've gotten more energy out of the fusion fuel than we put into the fusion fuel," he says.


Strictly speaking, while more energy came from fusion than went into the hydrogen fuel, only about 1 percent of the laser's energy ever reached the fuel. Useful levels of fusion are still a long way off. "They didn't get more fusion power out than they put in with the laser," says Steve Cowley, the head of a huge fusion experiment in the U.K. called the Joint European Torus, or JET.

 

The laser is known as the National Ignition Facility, or NIF. Constructed at a cost of more than $3 billion, it consists of 192 beams that take up the length of three football fields. For a brief moment, the beams can focus 500 trillion watts of power — more power than is being used in that same time across the entire United States — onto a target about the width of a No. 2 pencil.

 

The goal is fusion. Fusion is a process where hydrogen atoms are squeezed together to make helium atoms. When that happens, a lot of energy comes out. It could mean the answer to the world's energy problems, but fusion is really, really hard to do. Hurricane says that each time they try, it feels like they're taking a test.

 

"Of course you want to score real well, you think you've learned the material, but you just have to see how you do," he says.

 

Over the past few years, NIF has been getting a fat "F." For all its power, it just couldn't get the hydrogen to fuse, and researchers didn't know why. The failures have led NIF's critics to label the facility an enormous waste of taxpayer dollars. In 2012, the government shifted NIF away from its fusion goals to focus on its other mission: simulating the conditions inside nuclear weapons.

 

But the fusion experiments continued, and Hurricane says researchers now understand why their original strategy wasn't working. In the journal Nature, he and his colleagues report that they've finally figured out how to squeeze the fuel with the lasers. By doing a lot of squeezing right at the start, they were able to keep the fuel from churning and squirting out. The lasers squeezed evenly and the hydrogen turned into helium. The new technique can't reach "ignition," which is the point at which the hydrogen fusion feeds on itself to make more. Even so, JET's Cowley says, this is still a big moment for NIF.


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Quantum engineering pushes quantum absorption refrigerator beyond classical efficiency limits

Quantum engineering pushes quantum absorption refrigerator beyond classical efficiency limits | green technology | Scoop.it

The laws of thermodynamics determine what is possible and impossible in classical systems. Lately, scientists have been working on establishing quantum analogues of these fundamental laws to determine the performance limits of quantum systems. Now in a new study, scientists have established the thermodynamic limits on quantum absorption refrigerators, and then somewhat counterintuitively show how quantum engineering techniques can push the refrigerators beyond these limits, resulting in superefficient cooling.


The findings show how quantum enhancements can allow quantum systems to exceed what is classically achievable, and marks a promising step toward the development of practical quantum cooling technologies. The researchers, Luis A. Correa, et al., from the University of La Laguna in Spain and the University of Nottingham in the UK, have published their paper on quantum-enhanced refrigeration in a recent issue of Nature Scientific Reports.


Whether classical or quantum in nature, refrigerators function by transporting energy from a cold reservoir (the object to be cooled) to a hot reservoir, usually with assistance from a power source or, in the case of an absorption refrigerator, an additional work reservoir.

"First patented by Einstein himself, absorption fridges are really 'cool,'" coauthor Gerardo Adesso at the University of Nottingham told Phys.org. "They refrigerate by absorbing heat from outside, without having to be plugged to a power socket. People use them, e.g., while camping, but these fridges have been traditionally hindered by quite a low cooling power." For any refrigerator, the efficiency of the refrigeration process cannot exceed the Carnot limit, or else it would violate the second law of thermodynamics.


In the new study, the scientists investigated the theoretical maximum efficiency of a quantum refrigerator operating at maximum power. Efficiency at maximum power is of greater practical interest than efficiency in general, since power vanishes at high efficiencies. Here, the scientists proved that the efficiency at maximum power of a quantum refrigerator of any kind is limited by a fraction of the Carnot limit.

 

"Discovering that all quantum absorption fridges admit a tight model-independent performance limit was indeed surprising," Adesso said. "Establishing these bounds on efficiency at maximum power for heat engines and refrigerators has been a long-standing problem in finite-time thermodynamics."

 

Although this limit holds for all models of quantum absorption refrigerators, it is not the final answer. In the second part of their paper, the researchers show that quantum refrigerators can boost their performance by exploiting the system's quantum features.


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Neutrino Experiments Come Closer to Seeing Charge-parity Violation

Neutrino Experiments Come Closer to Seeing Charge-parity Violation | green technology | Scoop.it

Charge-parity (CP) violation—evidence that the laws of physics are different for particles and antiparticles—is often invoked as a “must” to explain why we observe more matter than antimatter in the universe. But the CP violation observed in interactions involving quarks is insufficient to explain this asymmetry. As a result, many theorists are looking toward leptons—and, specifically, neutrinos—for additional sources of CP violation. Researchers running the Tokai to Kamioka (T2K) experiment—a particle physics experiment at the Japan Proton Accelerator Research Complex (J-PARC)—have now made an important contribution toward the search for CP violation in neutrinos. Writing in Physical Review Letters, the T2K collaboration reports the strongest evidence to date for the appearance of electron neutrinos from a pure muon neutrino beam [1]. Their measurement allows them to determine a fundamental parameter of the standard model of particle physics, called θ13, which can in turn be used to make an early estimate of CP violation in neutrinos. Although this estimate has a large uncertainty, it will serve as a guide to future, more definitive neutrino experiments that are directly sensitive to CP violation.


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A Secret World Lies Beneath The Waves: Ocean Drifters

"Ocean Drifters, a secret world beneath the waves" is written, produced and directed by Dr Richard Kirby (Marine Institute Research Fellow, Plymouth University) with a narration by Sir David Attenborough and music by Richard Grassby-Lewis.

 

Drawing upon Richard Kirby's plankton imagery, Ocean Drifters reveals how the plankton have shaped life on Earth and continue to influence our lives in ways that most of us never imagine.

 

Further information about the plankton can be found at the Ocean Drifters website (oceandrifters.org) and in the popular book about plankton also titled "Ocean Drifters, a secret world beneath the waves".


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Marian Locksley's curator insight, March 10, 2014 4:22 AM

10.3.14 ~ 

Citizen science study to map the oceans' plankton

By Mark KinverEnvironment reporter, BBC News

 

http://www.bbc.co.uk/news/science-environment-26483166

 

 

Without these ancient cells, you wouldn’t be here BY REBECCA JACOBSON  March 6, 2014 

http://www.pbs.org/newshour/updates/tiny-ocean-organism-brought-earth-life/

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Quantum Microscope May Be Able to See Fine Details Inside Living Cells

Quantum Microscope May Be Able to See Fine Details Inside Living Cells | green technology | Scoop.it

By combining quantum mechanical quirks of light with a technique called photonic force microscopy, scientists can now probe detailed structures inside living cells like never before. This ability could bring into focus previously invisible processes and help biologists better understand how cells work.

 

Photonic force microscopy is similar to atomic force microscopy, where a fine-tipped needle is used to scan the surface of something extremely small such as DNA. Rather than a needle, researchers used extremely tiny fat granules about 300 nanometers in diameter to map out the flow of cytoplasm inside yeast cells with high precision.

 

To see where these miniscule fat particles were, they shined a laser on them. Here, the researchers had to rely on what’s known as squeezed light. Photons of light are inherently noisy and because of this, a laser beam’s light particles won’t all hit a detector at the same time. There is a slight randomness to their arrival that makes for a fuzzy picture. But squeezed light uses quantum mechanical tricks to reduce this noise and clear up the fuzziness.

 

“The essential idea was to use this noise-reduced light to locate the nano-particles inside a cell,” said physicist Warwick Bowen of the University of Queensland in Australia, co-author of a paper that came out Feb. 4 in Physical Review X.

 

The reason behind all this was to overcome a fundamental optical limit that has always caused headaches for biologists. The diffraction limit of light puts a constraint on the size of something you can resolve with a microscope for a given wavelength of light. For visible wavelengths, this limit is about 250 nanometers. Anything smaller can’t be easily seen. The trouble is, a lot of structures inside of cells, including organelles, cytoskeletons, and individual proteins, are much smaller than this.

 

Scientists have come up with clever ways to get around the diffraction limit and resolve things as small as 20 nanometers. But the new quantum technique has pushed that limit even farther. Instead of using light, Bowen’s team passed a nano-particle over the surface of cellular structures, sort of like running your finger over a bumpy surface. They held onto their fat granule probe using optical tweezers, which are basically a nanoscale version of a tractor beam. In an optical tweezer, scientists create a laser beam with an electromagnetic field along its length. The field is strongest at the center of the beam, allowing tiny objects to be drawn to this point and held there.

 

Because the fat granules occur naturally, the cells don’t need to be prepared like they would for atomic force microscopy, which generally involves killing the cells. That’s a big deal because it means photonic force microscopy can be used to visualize processes inside living cells. The team has tracked these granules with a resolution of about 10 nanometers.


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Is vibration energy the secret to self-powered electronics in the near future?

Is vibration energy the secret to self-powered electronics in the near future? | green technology | Scoop.it

A multi-university team of engineers has developed what could be a promising solution for charging smartphone batteries on the go — without the need for an electrical cord.

 

Incorporated directly into a cell phone housing, the team's nanogenerator could harvest and convert vibration energy from a surface, such as the passenger seat of a moving vehicle, into power for the phone. "We believe this development could be a new solution for creating self-charged personal electronics," says Xudong Wang, an assistant professor of materials science and engineering at the University of Wisconsin-Madison.

 

The nanogenerator takes advantage of a common piezoelectric polymer material called polyvinylidene fluoride, or PVDF. Piezoelectric materials can generate electricity from a mechanical force; conversely, they also can generate a mechanical strain from an applied electrical field.

 

Rather than relying on a strain or an electrical field, the researchers incorporated zinc oxide nanoparticles into a PVDF thin film to trigger formation of the piezoelectric phase that enables it to harvest vibration energy. Then, they etched the nanoparticles off the film; the resulting interconnected pores — called "mesopores" because of their size — cause the otherwise stiff material to behave somewhat like a sponge.

 

That sponge-like material is key to harvesting vibration energy. "The softer the material, the more sensitive it is to small vibrations," says Wang.

 

The nanogenerator itself includes thin electrode sheets on the front and back of the mesoporous polymer film, and the researchers can attach this soft, flexible film seamlessly to flat, rough or curvy surfaces, including human skin. In the case of a cell phone, it uses the phone's own weight to enhance its displacement and amplify its electrical output.

The nanogenerator could become an integrated part of an electronic device — for example, as its back panel or housing — and automatically harvest energy from ambient vibrations to power the device directly.


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Skin cells transformed into functioning liver cells in mouse study

Skin cells transformed into functioning liver cells in mouse study | green technology | Scoop.it
An important breakthrough has been made that could affect patients waiting for liver transplants. Scientists have discovered a way to transform skin cells into mature, fully functioning liver cells that flourish on their own, even after being transplanted into laboratory animals modified to mimic liver failure. In previous studies on liver-cell reprogramming, scientists had difficulty getting stem cell-derived liver cells to survive once being transplanted into existing liver tissue. But this team figured out a way to solve this problem, and have revealed a new cellular reprogramming method that transforms human skin cells into liver cells that are virtually indistinguishable from the cells that make up native liver tissue.

 

In previous studies on liver-cell reprogramming, scientists had difficulty getting stem cell-derived liver cells to survive once being transplanted into existing liver tissue. But the Gladstone-UCSF team figured out a way to solve this problem. Writing in the latest issue of the journalNature, researchers in the laboratories of Gladstone Senior Investigator Sheng Ding, PhD, and UCSF Associate Professor Holger Willenbring, MD, PhD, reveal a new cellular reprogramming method that transforms human skin cells into liver cells that are virtually indistinguishable from the cells that make up native liver tissue.


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Will plug-in electric cars crash the electric grid?

Will plug-in electric cars crash the electric grid? | green technology | Scoop.it

The growing number of plug-in electric cars — more than 96,000 bought in 2013 — may put a lot of new strain on the nation’s aging electrical distribution systems, like transformers and underground cables, especially at times of peak demand, according to University of Vermont (UVM) scientists. So they have created a novel solution, which they report on in the forthcoming March issue of IEEE Transactions on Smart Grid.


“The key to our approach is to break up the request for power from each car into multiple small chunks — into packets,” says Jeff Frolik, a professor in the College of Engineering and Mathematical Sciences and co-author on the new study. This is similar to transmitting data packets on the Internet.

 

By using the nation’s growing network of “smart meters” — a new generation of household electric meters that communicate information back-and-forth between a house and the utility — the new approach would let a car charge for, say, five or ten minutes at a time, Frolik says, and then wait to make another request for power. If demand was low, it would continue charging, but if it was high, the car would have to wait.

 

“Most of the time, as long as people get charged by morning, they won’t care,” says UVM’s Paul Hines, an expert on power systems and co-author on the study. “By charging cars in this way, it’s really easy to let everybody share the capacity that is available on the grid.”

 
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Eli Levine's curator insight, February 25, 2014 12:24 PM

This is going to be a significant challenge.

 

We need to get off fossil fuels if we're going to survive and I honestly don't give too many cares about the economic consequences that are going to have to be sorted out in order to do this.

 

We need to be off fossil fuels entirely, or we're going to die.

 

That means new infrastructure, new power plants, new methods of charging our homes, etc.

 

It means a decentralization away from the power companies and utlities.

 

And the biggest economic challenge that I see is how to employ all of those workers who are going to be laid off when the big fossil fuel companies finally kick the bucket.

 

You're an idiot if you want to keep it the same in this case.

 

Stupid conservatives.

 

Think about it.

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