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Friday, June 23, 2017

New Dual-Targeting Nanoparticles Lower Cancer’s Defenses and Attack Tumors

Cancer immunotherapy has emerged as one of the most exciting directions in cancer treatment. But the approach only works in a fraction of patients and can cause nasty side effects. 

Now, in the journal ACS Nano, scientists report the development of the first dual-cell targeting immunotherapy nanoparticle that slows tumor growth in mice with different cancers. In their study, up to half the mice in one cancer group went into full remission after the treatment.

Immunotherapy works by giving the body’s own immune system a boost in its fight against disease. In cancer patients, there are two main lines of immunotherapy: One disables cancer cells’ ability to hide from the immune system, and the other recruits the body’s T cells to destroy tumors. Jonathan P. Schneck and colleagues wanted to see if they could combine these two tactics with one nanoparticle-based platform.

A two-in-one approach to immunotherapy involves both blocking cancer cells’ (red) ability to hide and prompting T cells (gray) to attack them.

Credit: Andrea Danti/Shutterstock.com

To incorporate these two functions into one system, the researchers developed “immunoswitch” nanoparticles. They’re designed to simultaneously turn off a pathway on tumor cells that would otherwise be used to become invisible to the immune system, and turn on a specific T cell process that launches them into action against cancer cells. 

Testing on mouse models of melanoma and colon cancer showed that animals injected with the nanoparticles lived longer than those that did not receive the nanoparticles, and their tumor growth was delayed or even reversed in some cases. That the nanoparticles were effective against two different cancers suggests that they could help treat a variety of tumor types. 

Further analysis found that the platform created a synergistic effect, which researchers say allowed them to use low treatment concentrations to potentially reduce the severe side effects that dual immunotherapy is known for.

The authors acknowledge funding from the National Science Foundation, the Center of Cancer Nanotechnology Excellence at the Johns Hopkins Institute, the National Cancer Institute, the National Institutes of Health, the TEDCO/Maryland Innovation Initiative and the Wallace H. Coulter Foundation.

Contacts and sources:
American Chemical Society

Rapid Climate Tipping Points with Ocean Current Changes Revealed by Ice Cores

During the last glacial period, within only a few decades the influence of atmospheric CO2 on the North Atlantic circulation resulted in temperature increases of up to 10 degrees Celsius in Greenland – as indicated by new climate calculations from researchers at the Alfred Wegener Institute and the University of Cardiff. 
Their study is the first to confirm that there have been situations in our planet’s history in which gradually rising CO2 concentrations have set off abrupt changes in ocean circulation and climate at “tipping points”. These sudden changes, referred to as Dansgaard-Oeschger events, have been observed in ice cores collected in Greenland. The results of the study have just been released in the journal Nature Geoscience. 

Credit: AWI
Previous glacial periods were characterised by several abrupt climate changes in the high latitudes of the Northern Hemisphere. However, the cause of these past phenomena remains unclear. In an attempt to better grasp the role of CO2 in this context, scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) recently conducted a series of experiments using a coupled atmosphere-ocean-sea ice model.

First author Xu Zhang explains: “With this study, we’ve managed to show for the first time how gradual increases of CO2 triggered rapid warming.” This temperature rise is the result of interactions between ocean currents and the atmosphere, which the scientists used the climate model to explore. 
According to their findings, the increased CO2 intensifies the trade winds over Central America, as the eastern Pacific is warmed more than the western Atlantic. This is turn produces increased moisture transport from the Atlantic, and with it, an increase in the salinity and density of the surface water. 
Credit: AWI
Finally, these changes lead to an abrupt amplification of the large-scale overturning circulation in the Atlantic. “Our simulations indicate that even small changes in the CO2 concentration suffice to change the circulation pattern, which can end in sudden temperature increases,” says Zhang.

Further, the study’s authors reveal that rising CO2 levels are the dominant cause of changed ocean currents during the transitions between glacial and interglacial periods. As climate researcher Gerrit Lohmann explains, “We can’t say for certain whether rising CO2 levels will produce similar effects in the future, because the framework conditions today differ from those in a glacial period. 
Credit: AWI
That being said, we’ve now confirmed that there have definitely been abrupt climate changes in the Earth’s past that were the result of continually rising CO2 concentrations.”

The study received funding as part of a major Federal Ministry of Education and Research initiative on paleo-climate modelling (PalMod)

Contacts and sources:
Gerrit Lohmann
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI)

Citation: Nature Geoscience: Xu Zhang, Gregor Knorr, Gerrit Lohmann, Stephen Barker: "Abrupt North Atlantic circulation changes in response to gradual CO2 forcing in a glacial climate state" DOI: 10.1038/NGEO2974    

11,500 Year Old Evidence of Humans Impacting the Environment Found at Dead Sea Site

The earliest geological indication of humans' impact on the environment was discovered in the Dead Sea, Tel Aviv University (TAU) researchers say.

A new TAU study has uncovered the earliest known geological indications of man-made impact on geological processes, in particular erosion of the surface, from 11,500 years ago. Within a core sample retrieved from the Dead Sea, researchers discovered basin-wide erosion rates dramatically incompatible with known tectonic and climatic regimes of the period recorded.

Credit: TAU

"Human impact on the natural environment is now endangering the entire planet," said Prof. Shmuel Marco, Head of TAU's School of Geosciences, who led the research team. "It is therefore crucial to understand these fundamental processes. Our discovery provides a quantitative assessment for the commencement of significant human impact on the Earth's geology and ecosystems." The results of the study were published in Global and Planetary Change.

The research was conducted by TAU post-doctoral student Dr. Yin Lu and in collaboration with Prof. Dani Nadel and Prof. Nicolas Waldman, both of the University of Haifa. It took place as part of the Dead Sea Deep Drilling project, which harnessed a 1,500-foot-deep drill core to delve into the Dead Sea basin. The core sample provided the team with a sediment record of the last 220,000 years.

The newly-discovered erosion occurred during the Neolithic Revolution, the wide-scale transition of human cultures from hunting and gathering to agriculture and settlement. The shift resulted in an exponentially larger human population on the planet.

"Natural vegetation was replaced by crops, animals were domesticated, grazing reduced the natural plant cover, and deforestation provided more area for grazing," said Prof. Marco. "All these resulted in the intensified erosion of the surface and increased sedimentation, which we discovered in the Dead Sea core sample."

A natural laboratory in the Dead Sea

The Dead Sea drainage basin serves as a natural laboratory for understanding how sedimentation rates in a deep basin are related to climate change, tectonics, and man-made impacts on the landscape.

"We noted a sharp threefold increase in the fine sand that was carried into the Dead Sea by seasonal floods," said Prof. Marco. "This intensified erosion is incompatible with tectonic and climatic regimes during the Holocene, the geological epoch that began after the Pleistocene some 11,700 years ago."

The researchers are currently in the process of recovering the record of earthquakes from the same drill core. "We have identified disturbances in the sediment layers that were triggered by the shaking of the lake bottom," Prof. Marco said. "It will provide us with a 220,000-year record — the most extensive earthquake record in the world."

Contacts and sources:
Tel Aviv University (TAU)

Planet 10? Mars-Sized Planet Likely Warping Kuiper Belt - This Is Not Planet Nine Still Awaiting Confirmation

An unknown, unseen "planetary mass object" may lurk in the outer reaches of our solar system, according to new research on the orbits of minor planets to be published in the Astronomical Journal. This object would be different from -- and much closer than -- the so-called Planet Nine, a planet whose existence yet awaits confirmation.

In the paper, Kat Volk and Renu Malhotra of the University of Arizona's Lunar and Planetary Laboratory, or LPL, present compelling evidence of a yet-to-be- discovered planetary body with a mass somewhere between that of Mars and Earth. The mysterious mass, the authors show, has given away its presence -- for now -- only by controlling the orbital planes of a population of space rocks known as Kuiper Belt objects, or KBOs, in the icy outskirts of the solar system.

A planetary mass object the size of Mars would be sufficient to produce the observed perturbations in the distant Kuiper Belt.

Credit: Heather Roper/LPL

While most KBOs -- debris left over from the formation of the solar system -- orbit the sun with orbital tilts (inclinations) that average out to what planetary scientists call the invariable plane of the solar system, the most distant of the Kuiper Belt's objects do not. Their average plane, Volk and Malhotra discovered, is tilted away from the invariable plane by about eight degrees. In other words, something unknown is warping the average orbital plane of the outer solar system.

"The most likely explanation for our results is that there is some unseen mass," says Volk, a postdoctoral fellow at LPL and the lead author of the study. "According to our calculations, something as massive as Mars would be needed to cause the warp that we measured."

The Kuiper Belt lies beyond the orbit of Neptune and extends to a few hundred Astronomical Units, or AU, with one AU representing the distance between Earth and the sun. Like its inner solar system cousin, the asteroid belt between Mars and Jupiter, the Kuiper Belt hosts a vast number of minor planets, mostly small icy bodies (the precursors of comets), and a few dwarf planets.

For the study, Volk and Malhotra analyzed the tilt angles of the orbital planes of more than 600 objects in the Kuiper Belt in order to determine the common direction about which these orbital planes all precess. Precession refers to the slow change or "wobble" in the orientation of a rotating object.

KBOs operate in an analogous way to spinning tops, explains Malhotra, who is a Louise Foucar Marshall Science Research Professor and Regents' Professor of Planetary Sciences at LPL.

"Imagine you have lots and lots of fast-spinning tops, and you give each one a slight nudge," she says. "If you then take a snapshot of them, you will find that their spin axes will be at different orientations, but on average, they will be pointing to the local gravitational field of Earth.

A yet to be discovered, unseen 'planetary mass object' makes its existence known by ruffling the orbital plane of distant Kuiper Belt objects, according to research by Kat Volk and Renu Malhotra of the UA's Lunar and Planetary Laboratory. The object is pictured on a wide orbit far beyond Pluto in this artist's illustration.

Credit: Heather Roper/LPL

"We expect each of the KBOs' orbital tilt angle to be at a different orientation, but on average, they will be pointing perpendicular to the plane determined by the sun and the big planets."

If one were to think of the average orbital plane of objects in the outer solar system as a sheet, it should be quite flat past 50 AU, according to Volk.

"But going further out from 50 to 80 AU, we found that the average plane actually warps away from the invariable plane," she explains. "There is a range of uncertainties for the measured warp, but there is not more than 1 or 2 percent chance that this warp is merely a statistical fluke of the limited observational sample of KBOs."

In other words, the effect is most likely a real signal rather than a statistical fluke. According to the calculations, an object with the mass of Mars orbiting roughly 60 AU from the sun on an orbit tilted by about eight degrees (to the average plane of the known planets) has sufficient gravitational influence to warp the orbital plane of the distant KBOs within about 10 AU to either side.

"The observed distant KBOs are concentrated in a ring about 30 AU wide and would feel the gravity of such a planetary mass object over time," Volk said, "so hypothesizing one planetary mass to cause the observed warp is not unreasonable across that distance."

This rules out the possibility that the postulated object in this case could be the hypothetical Planet Nine, whose existence has been suggested based on other observations. That planet is predicted to be much more massive (about 10 Earth masses) and much farther out at 500 to 700 AU.

"That is too far away to influence these KBOs," Volk said. "It certainly has to be much closer than 100 AU to substantially affect the KBOs in that range."

Because a planet, by definition, has to have cleared its orbit of minor planets such as KBOs, the authors refer to the hypothetical mass as a planetary mass object. The data also do not rule out the possibility that the warp could result from more than one planetary mass object.

So why haven't we found it yet? Most likely, according to Malhotra and Volk, because we haven't yet searched the entire sky for distant solar system objects. The most likely place a planetary mass object could be hiding would be in the galactic plane, an area so densely packed with stars that solar system surveys tend to avoid it.

"The chance that we have not found such an object of the right brightness and distance simply because of the limitations of the surveys is estimated to be to about 30 percent," Volk said.

A possible alternative to an unseen object that could have ruffled the plane of outer Kuiper Belt objects could be a star that buzzed the solar system in recent (by astronomical standards) history, the authors said.

"A passing star would draw all the 'spinning tops' in one direction," Malhotra said. "Once the star is gone, all the KBOs will go back to precessing around their previous plane. That would have required an extremely close passage at about 100 AU, and the warp would be erased within 10 million years, so we don't consider this a likely scenario."

Humankind's chance to catch a glimpse of the mysterious object might come fairly soon once construction of the Large Synoptic Survey Telescope is completed. Run by a consortium that includes the UA and scheduled for first light in 2020, the instrument will take unprecedented, real-time surveys of the sky, night after night.

"We expect LSST to bring the number of observed KBOs from currently about 2000 to 40,000," Malhotra said. "There are a lot more KBOs out there -- we just have not seen them yet. Some of them are too far and dim even for LSST to spot, but because the telescope will cover the sky much more comprehensively than current surveys, it should be able to detect this object, if it's out there."


Contacts and sources:
Daniel Stolte
University of Arizona

Citation:  "The curiously warped mean plane of the Kuiper belt," is online at https://arxiv.org/abs/1704.02444

Origins of the Sun’s Swirling Spicules Discovered

At any given moment, as many as 10 million wild jets of solar material burst from the sun's surface. They erupt as fast as 60 miles per second, and can reach lengths of 6,000 miles before collapsing. These are spicules, and despite their grass-like abundance, scientists didn't understand how they form. Now, for the first time, a computer simulation -- so detailed it took a full year to run -- shows how spicules form, helping scientists understand how spicules can break free of the sun's surface and surge upward so quickly.

This work relied upon high-cadence observations from NASA's Interface Region Imaging Spectrograph, or IRIS, and the Swedish 1-meter Solar Telescope in La Palma, in the Canary Islands. Together, the spacecraft and telescope peer into the lower layers of the sun's atmosphere, known as the interface region, where spicules form. The results of this NASA-funded study were published in Science on June 22, 2017 -- a special time of the year for the IRIS mission, which celebrates its fourth anniversary in space on June 26.

At any given moment, as many as 10 million wild jets of solar material burst from the sun's surface. They erupt as fast as 60 miles per second, and can reach lengths of 6,000 miles before collapsing. These are spicules, and despite their grass-like abundance, scientists didn't understand how they form. Now, for the first time, a computer simulation -- so detailed it took a full year to run -- shows how spicules form, helping scientists understand how spicules can break free of the sun's surface and surge upward so quickly.

Watch the video to learn how scientists used a combination of computer simulations and observations to determine how spicules form.

Credits: NASA’s Goddard Space Flight Center/Joy Ng, producer

"Numerical models and observations go hand in hand in our research," said Bart De Pontieu, an author of the study and IRIS science lead at Lockheed Martin Solar and Astrophysics Laboratory, in Palo Alto, California. "We compare observations and models to figure out how well our models are performing, and to improve the models when we see major discrepancies."

Observing spicules has been a thorny problem for scientists who want to understand how solar material and energy move through and away from the sun. Spicules are transient, forming and collapsing over the course of just five to 10 minutes. These tenuous structures are also difficult to study from Earth, where the atmosphere often blurs our telescopes' vision.

A team of scientists has been working on this particular model for nearly a decade, trying again and again to create a version that would create spicules. Earlier versions of the model treated the interface region, the lower solar atmosphere, as a hot gas of electrically charged particles -- or more technically, a fully ionized plasma. But the scientists knew something was missing because they never saw spicules in the simulations.

The key, the scientists realized, was neutral particles. They were inspired by Earth's own ionosphere, a region of the upper atmosphere where interactions between neutral and charged particles are responsible for many dynamic processes.

The research team knew that in cooler regions of the sun, such as the interface region, not all gas particles are electrically charged. Some particles are neutral, and neutral particles aren't subject to magnetic fields like charged particles are. Scientists had based previous models on a fully ionized plasma in order to simplify the problem. Indeed, including the necessary neutral particles was very computationally expensive, and the final model took roughly a year to run on the Pleiades supercomputer located at NASA's Ames Research Center in Silicon Valley, and which supports hundreds of science and engineering projects for NASA missions.

Solar spicules
image of solar spicules
Credit: NASA

The model began with a basic understanding of how plasma moves in the sun's atmosphere. Constant convection, or boiling, of material throughout the sun generates islands of tangled magnetic fields. When boiling carries them up to the surface and farther into the sun's lower atmosphere, magnetic field lines rapidly snap back into place to resolve the tension, expelling plasma and energy. Out of this violence, a spicule is born. But explaining how these complex magnetic knots rise and snap was the tricky part.

"Usually magnetic fields are tightly coupled to charged particles," said Juan Martínez-Sykora, lead author of the study and a solar physicist at Lockheed Martin and the Bay Area Environmental Research Institute in Sonoma, California. "With only charged particles in the model, the magnetic fields were stuck, and couldn't rise beyond the sun's surface. When we added neutrals, the magnetic fields could move more freely."

Neutral particles provide the buoyancy the gnarled knots of magnetic energy need to rise through the sun's boiling plasma and reach the chromosphere. There, they snap into spicules, releasing both plasma and energy. Friction between ions and neutral particles heats the plasma even more, both in and around the spicules.

With the new model, the simulations at last matched observations from IRIS and the Swedish Solar Telescope; spicules occurred naturally and frequently. The 10 years of work that went into developing this numerical model earned scientists Mats Carlsson and Viggo H. Hansteen, both authors of the study from the University of Oslo in Norway, the 2017 Arctowski Medal from the National Academy of Sciences. Martínez-Sykora led the expansion of the model to include the effects of neutral particles.

The scientists' updated model revealed something else about how energy moves in the solar atmosphere. It turns out this whip-like process also naturally generates Alfvén waves, a strong kind of magnetic wave scientists suspect is key to heating the sun's atmosphere and propelling the solar wind, which constantly bathes our solar system and planet with charged particles from the sun.

"This model answers a lot of questions we've had for so many years," De Pontieu said. "We gradually increased the physical complexity of numerical models based on high-resolution observations, and it is really a success story for the approach we've taken with IRIS."

The simulations indicate spicules could play a big role in energizing the sun's atmosphere, by constantly forcing plasma out and generating so many Alfvén waves across the sun's entire surface.

"This is a major advance in our understanding of what processes can energize the solar atmosphere, and lays the foundation for investigations with even more detail to determine how big of a role spicules play," said Adrian Daw, IRIS mission scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "A very nice result on the eve of our launch anniversary."

Contacts and sources:
Lina Tran
Goddard Space Flight Center

Thursday, June 22, 2017

Magnetic Meteoritic Memories of Metal World Psyche

Research deciphering the hidden magnetic messages encoded in a rare group of meteorites has helped secure nearly half a billion dollars of NASA funding for a journey to their parent asteroid. 

4.5 billion years ago in the violent, high-speed environment of the early solar system, a protoplanet roughly the size of Mars was involved in a series of fierce collisions with other large planetary bodies.

A number of powerful impacts stripped the planet of its rocky mantle, leaving an exposed nickel-iron core. After further blows, break-away pieces of metal were flung into space -- the final destination for some would be Earth.

This, scientists believe, is the story of Psyche. Now a cold metal world in the asteroid belt between Mars and Jupiter, the asteroid -- named after the Greek goddess of the soul- offers a unique vision of the violent history of collisions and accretion that created the terrestrial planets.

This is an artist's concept of the Psyche spacecraft, which will conduct a direct exploration of an asteroid thought to be a stripped planetary core.

Image credit: NASA/JPL-Caltech

Research published in Earth and Planetary Science Letters has helped secure $450 million of NASA funding for a satellite to boldly go where no satellite has been before; on a mission to Psyche.

The study, led by a Fellow at St John's College, Cambridge, Dr James Bryson, reveals the hidden magnetic messages in a rare group of metal meteorites which scientists believe are from Psyche. The results indicate that Psyche had a strong and unstable magnetic field and support the hypothesis that the asteroid is an exposed planetary core that cooled quickly due to the absence of a rocky mantle. These conclusions about Psyche, reached in the laboratory, will now be tested by an eponymous mission to outer space.

The Psyche satellite will orbit the asteroid while gathering data. If proved correct, a pan-institutional team of scientists led by Professor Lindy Elkins-Tanton from Arizona State University, will have the opportunity to directly measure a metallic core like the ones that lie at inaccessible depths and conditions within the terrestrial planets, including Earth. Exploring this unknown world will provide researchers with a remarkable insight into the building blocks of planet formation and will enable scientists and the public to see, for the first time, a world made of metal rather than ice, rock or gas.

The study of magnetic messages in meteorites can yield important information about their parent body. Like a hard drive, meteorites store magnetic information and can reveal whether the object they came from generated a magnetic field and if so what that field was like.

In the case of Psyche, finding out about the magnetic field it once generated would allow researchers to infer important conclusions about its properties and formation such as how and at what speed it cooled and solidified.

The clues contained within metal-rich meteorites, however, were thought to be impossible to decipher. This is because metal meteorites are primarily made out of large pieces of iron - a material with a poor magnetic memory that engineers would steer well clear of when building a computer.

This changed when during his PhD, Bryson developed a pioneering detailed imaging technique to read the hidden magnetic memory of metal meteorites. "After developing the technique, I was talking about my work at a conference last year when I was approached by members of the Psyche team. They had a group of meteorites thought to be from Psyche due to their elemental composition and the rate at which they had cooled. They asked me to analyse them in the lab to see what they could tell us about the asteroid," said Bryson.

Hidden within the iron bulk of the meteorites, Bryson identified tiny particles of a metal called tetrataenite. This material is magnetically much more stable than iron and is capable of holding a magnetic memory going back billions of years. Reading the tetrataenite was a challenge because the particles measured between 10-100 nanometres (one nanometre is one billionth of a metre). However, using a big ring of magnets called a synchrotron which fires electrons around at near the speed of light, Bryson was able to produce intense beams of x-rays that allowed him to image the particles and measure the nanoscale magnetisation of the meteoric metal.

In addition, Bryson then carried out more conventional measurements of the magnetism of tiny pieces of rock contained within some of the meteorites using a magnetometer.

The results were consistent with the theory that Psyche is an exposed metal core as they suggest that the asteroid cooled very quickly, something scientists would expect to observe in a core stripped of its protective mantel. The meteorites contained the memory of an intense magnetic field, far stronger than Earth's. Planetary magnetic fields are produced by the churning motions of liquid metals in a planet's core that conduct electricity and have an electrical charge. Faster cooling generates strong convection currents which drive the liquid core to swirl faster and produce a more powerful magnetic field.

The secrets given up by the meteorites also suggested that Psyche's magnetic field was volatile, another property consistent with rapid cooling. When there is a vigorous liquid metal motion in a core caused by rapid cooling the positions of magnetic north and magnetic south are unstable and can interchange. The meteorites contained a record of being magnetised in different directions at distinct times supporting the idea that Psyche's magnetic field alternated in its polarity.

Evidence from the meteorites also indicates that, unlike the cooling process currently underway in Earth's core, Psyche cooled from the outside in. "In the case of Earth's core there is a lot of pressure from the rock in the mantle above which is causing its centre to solidify first. In the absence of a mantle, a core is more likely to start solidifying at the surface. This is exciting because we have never been able to study what this process looks like. Since Psyche cooled so quickly, the mission offers the opportunity to study an entire lifetime of planetary activity" said Bryson.

During the Psyche mission a magnetometer composed of two identical high-sensitivity magnetic field sensors will be attached to the satellite to detect and measure the remnant magnetic field of the asteroid. Other instruments will also measure Psyche's gravity field and elemental composition.

The mission, which was chosen by NASA in January 2017, is targeted to launch in October 2023. It will take six years to travel to the asteroid using solar-electric propulsion, arriving in 2030. Once there, the satellite will orbit the metal world for 12 months, performing its operations from four staging orbits and sending a stream of images and data back to Earth. The satellite will then crash into Psyche, bringing the mission to an end.

Contacts and sources:
Shelley Hughes
St John's College, Cambridge

Citation:  Paleomagnetic evidence for dynamo activity driven by inward crystallisation of a metallic asteroid, published in Earth and Planetary Science Letters is available via: http://www.sciencedirect.com/science/article/pii/S0012821X17302923 It will also be available in Volume 472 of the printed version of the Journal, to be published on 15 August 2017.

New Conductivity Mechanism of Ions Discovered: How Protons Move Through a Fuel Cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.


Image: iStock

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton conductivity is crucial for the latter; protons, i.e. positively charged hydrogen ions, are formed from hydrogen, which is used to power the fuel cell. 

Empa physicist Artur Braun and Qianli Chen, a doctoral student at ETH Zurich, conducted neutron scattering experiments on the Swiss Spallation Neutron Source (SINQ) at the Paul Scherrer Institute (PSI) that document the mobility of protons in the crystal lattice. In the process, they observed that the proton movements in ceramic fuel cells obey far more complex laws than previously assumed: The movement of the protons takes place according to the so-called polaron model, as the researchers recently reported in the renowned journal Nature Communications.

The experiments have been conducted with Barium ceric oxide. The crystal is non conductive in a dry state. When moisture comes in, the protons form OH-bondings and move through the crystal.

The polaron model

Credit: Empa

For a long time, the polaron theory developed by the Russian physicist and eventual Nobel Prize-winner Lev Davidovich Landau in 1933 only applied to electrons. The model describes how electrons “worm” their way through a dielectric crystal and force “interfering” atoms out of position, which slows down the electrons. In other words, polarons are waves of movement in the crystal, the spread of which can be described as the trajectory of a particle. They can be deflected and reflected.

The electron polaron has long been a pillar of theoretical physics and the undisputed basis for applied model calculations in expert circles. By contrast, the existence of a hydrogen polaron – i.e. a hydrogen ion that “hops” from one position to the next – was only a speculative theory until now. Although biologists used the model of hopping hydrogen atoms to explain certain metabolic processes, solid-state physicists did not regard hydrogen polarons as a valid explanatory model.

This could now change: Based on experiments using yttrium-doped barium ceric oxide and barium zirconium oxide crystals, Braun and Chen managed to prove the existence of the proton polaron. In a dry state, these crystals are non-conductive. If they are exposed to a steam atmosphere, however, OH groups form inside the crystal structure. Released protons can then move in a wavelike fashion and the oxide becomes ionically conductive. 
Heat and high pressure provide proof

Braun and Chen found evidence of hydrogen ion waves by studying the crystals under different high pressure conditions and at temperatures of up to 600 degrees Celsius. Empa’s good connectivity in the scientific world was pivotal: The samples were x-rayed on PSI’s neutron source and the high pressure experiments on the crystals were conducted in conjunction with researchers from the Faculty of Geosciences/Geography at Goethe University, Frankfurt am Main.

The result: At temperatures of between 220 and 520 degrees, the conductivity increases to exactly the same extent as predicted in model calculations for the lattice vibrations of the crystal. The protons are therefore initially bound in the crystal lattice and begin to hop through the crystal from one OH group to another in the concert of lattice vibrations when heated. If the crystal is exposed to high pressure with a special compactor, there is less space for the proton leaps and the conductivity drops again. This proves that the polaron model applies to both electrons and protons. “And who knows, perhaps the theory also holds true for other ions such as lithium,” speculates Braun.

The Empa researchers’ findings could soon yield vital information on the choice of material for fuel cells and hydrogen storage systems – and thus influence the energy supply of the future. However, the behavior of ceramic insulators can also be gaged more effectively now: Do they still insulate well in high temperatures in the humid outside air? Or do current leakages develop that can be attributed to polaron conduction? Thanks to Braun and Chen’s project, which was funded by the Swiss National Science Foundation (SNSF), certain riddles of materials science can thus be solved.

Contacts and sources:
Dr. Artur Braun
Rainer Klose
Empa. Swiss Federal Laboratories for Materials Science and Technology

Citation:  Experimental neutron scattering evidence for proton polaron in hydrated metal oxide proton conductors Artur Braun & Qianli Chen Nature Communications 8, Article number: 15830 (2017) doi:10.1038/ncomms15830

An End to Population Aging in China, Germany, USA

Population aging could peak by 2040 in Germany and by 2070 in China, according to a new study published in the journal PLOS ONE, which combines new measures of aging with probabilistic population projections from the UN. In the USA, the study shows very little population aging at all in the coming century.

Population aging has been a major concern for many countries. Growing numbers of older people compared to younger ones in a population could create unsustainable burdens on social support and healthcare systems if a greater number of older people are dependent on a declining proportion of working-age people in the population.

Traditional population projections categorize “old age” as a simple cutoff at age 65. But as life expectancies have increased, so too have the years that people remain healthy, active, and productive. In the last decade, IIASA researchers have published a large body of research showing that the very boundary of “old age” should shift with changes in life expectancy, and have introduced new measures of aging that are based on population characteristics, giving a more comprehensive view of population aging.

Credit: Wikimedia Commons

The study combines these new measures with UN probabilistic population projections to produce a new set of age structure projections for four countries: China, Germany, Iran, and the USA.

“Both of these demographic techniques are relatively new, and together they give us a very different, and more nuanced picture of what the future of aging might look like,” says Warren Sanderson, a researcher at IIASA and Stony Brook University in the USA who wrote the article with Sergei Scherbov, leader of the Re-Aging Project at IIASA, and Patrick Gerland, chief of the mortality section of the Population Division of the United Nations.

One of the measures used in the paper looks at life expectancy as well as years lived to adjust the definition of old age. Probabilistic projections produce a range of thousands of potential scenarios, so that they can show a range of possibilities of aging outcomes.

For China, Germany, and the USA, the study showed that population aging would peak and begin declining well before the end of the century. Iran, which had an extremely rapid fall in fertility rate in the last 20 years, has an unstable age distribution and the results for the country were highly uncertain.

“We chose these four countries for analysis because they have very different population structures and projections, and so they allow us to test this methodology across a range of possible scenarios,” says Scherbov.


Contacts and sources:
The International Institute for Applied Systems Analysis (IIASA)

Citation: Sanderson WC, Scherbov S, and Gerland P (2017). Probabilistic Population Aging PLOS ONE.21 June 2017. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0179171

New Measures of Aging Show 70 Is the New 60, Study Predicts End to Population Aging in USA, China and Germany by 2100

Is 70 the new 60? A new Stony Brook University-led study to be published in PLOS ONE uses new measures of aging to scientifically illustrate that one’s actual age is not necessarily the best measure of human aging itself, but rather aging should be based on the number of years people are likely to live in a given country in the 21st Century.

The study combines the new measures of aging with probabilistic projections from the United Nations and predicts an end to population aging in the U.S. and other countries before the end of the century. Population aging – when the median age rises in a country because of increasing life expectancy and lower fertility rates -- is a concern for countries because of the perception that population aging leads to declining numbers of working age people and additional social burdens.

According to Warren Sanderson, Professor of Economics at Stony Brook University and the lead author, this study’s projections imply that as life expectancies increase people are generally healthier with better cognition at older ages and countries can adjust public policies appropriately as to population aging.

Warren Sanderson, Professor of Economics, Stony Brook University
Warren Sanderson, Professor of Economics, Stony Brook University
Credit: Stony Brook University

Population aging could peak by 2040 in Germany and by 2070 in China, according to the study, which combines measures of aging with probabilistic population projections from the UN. In the USA, the study shows very little population aging at all in the coming century.

Traditional population projections categorize “old age” as a simple cutoff at age 65. But as life expectancies have increased, so too have the years that people remain healthy, active, and productive. In the last decade, IIASA researchers have published a large body of research showing that the very boundary of “old age” should shift with changes in life expectancy, and have introduced new measures of aging that are based on population characteristics, giving a more comprehensive view of population aging.

The study combines these new measures with UN probabilistic population projections to produce a new set of age structure projections for four countries: China, Germany, Iran, and the USA.

“Both of these demographic techniques are relatively new, and together they give us a very different, and more nuanced picture of what the future of aging might look like,” says Professor Sanderson, also a researcher at IIASA. He wrote the article with Sergei Scherbov, leader of the Re-Aging Project at IIASA, and Patrick Gerland, chief of the mortality section of the Population Division of the United Nations.

One of the measures used in the paper looks at life expectancy as well as years lived to adjust the definition of old age. Probabilistic projections produce a range of thousands of potential scenarios, so that they can show a range of possibilities of aging outcomes.

For China, Germany, and the USA, the study showed that population aging would peak and begin declining well before the end of the century. Iran, which had an extremely rapid fall in fertility rate in the last 20 years, has an unstable age distribution and the results for the country were highly uncertain.

“We chose these four countries for analysis because they have very different population structures and projections, and so they allow us to test this methodology across a range of possible scenarios,” summarizes Scherbov.

Contacts and sources: 
Stony Brook University

Research Provides Practical Cooking Tips for Your Red Wine Sauce

Can you get intoxicated by pouring beer or wine into your sauce or stew? This question is important if you are pregnant, have to drive a car or want to track calories. New research from the University of Copenhagen and the Carlsberg Research Center creates a model for how alcohol disappears from a sauce or another liquid dish cooked in a saucepan. This model can thus be used to control the alcohol content.

Foto: Cecilie Varming Jacobsen

Postdoc at the Department of Food Science at the University of Copenhagen Pia Snitkjær has carried out a series of experiments with alcohol in liquid dishes to figure out how to control the alcohol content during cooking for the benefit of large kitchens, the food industry, the gastronomy and restaurant sector as well as in the kitchen at home.

“In the experiments I used 900 ml veal stock plus 150 ml beer or wine. At this mixing ratio, the alcohol concentration starts at approx. 2 %, but drops to 0.2% after a half an hour of cooking,” explains Pia Snitkjær, who underlines that this example is based on wine.

Precisely how much alcohol is left in, for example, a red wine sauce depends on three factors that you need to check if you want to control the alcohol content in a liquid dish or sauce, namely how much the dish is reduced, whether it is cooked with or without a lid and how much alcohol is added from the start (also see the box).

“One should remember that you typically eat only ½-1 deciliter of sauce. If we, for example, assume that you eat 100 ml sauce, with a concentration of 2 vol % it corresponds to an intake of 2ml of alcohol. There are 15 ml in a unit of alcohol, so a pregnant woman would also be able to handle it,” explains Pia Snitkjær.

All other factors the researchers studied – including the dimensions of the saucepan and the cooking temperature – proved to only be significant because they could affect how quickly the sauce was reduced.

The figure illustrates how the concentration of alcohol decreases as the contents of the saucepan are reduced for the seven sauce decoctions. These tests were conducted at different temperatures (100, 84 and 59 ⁰C) and with saucepans of varying heights and diameters.

Credit: University of Copenhagen

Using elementary physical chemistry, which has to do with understanding the volatility of alcohol when mixed with water and heated, Associate Professor Jens Risbo from the Department of Food Science at the University of Copenhagen has developed a model that shows how the alcohol behaves in liquid dishes. That it is the volume of the dish that is the best parameter for determining the alcohol content – and not the cooking time – matters in relation to which techniques you can use if you want to reduce the alcohol content in the finished dish.

“You can reduce the alcohol content quickly by bringing a dish to a rolling boil, because by boiling hard, the volume will also decrease rapidly. But if you do not want the food to boil down too much, you can keep adding water as water evaporates, which will also lower the alcohol content both by dilution and evaporation,” says Pia Snitkjær.
Put the lid on for a reverse distillation

If you want to reduce the alcohol content, you can put the lid on the saucepan.

“By placing a lid on the saucepan, there is a kind of reverse distillation where the alcohol disappears even more rapidly from the saucepan than the water. This is because alcohol is more volatile than water and thus can more readily evaporate. This is the same effect you use when you distil alcohol – you heat it up, so the alcohol evaporates more than the water, after which you can condense the vapours and obtain more concentrated alcohol,” explains Pia Snitkjær.

The lid does not sit tightly on the saucepan, allowing the steam escape under the lid so that the alcohol evaporates, while the water condenses more preferential on the colder lid and runs back into the pan. As it cooks, more and more alcohol escapes under the lid, while the contents of the saucepan will contain a higher percentage of water. Experiments show that the use of a very lid has a dramatic effect on obtaining a low concentration of alcohol.
Important for the calorie balance

The study has an impact on the calculation of the calorie content in recipes. Alcohol contains a lot of calories, but will probably be listed in a recipe with the calorie content the alcohol has as an ingredient before it is actually added to the dish, which results in a misleadingly high result.

“How many fewer calories there are depends on how much alcohol is evaporated. 1 gram of alcohol gives approx. 7 calories, so every time you evaporate 1 gram of alcohol, you have 7 fewer calories in the saucepan,” explains Pia Snitkjær, who plans to develop the model to make it even more practical.

“It would be nice to be able to say precisely what this means for a tomato soup, a meat dish, etc. There are many things that can vary the result, but you can get some ideas about what happens when some of the most important parameters are changed – for example, what happens if you have a lot of sugar or a lot of gelatine, like in a base sauce,” says Pia Snitkjær.

Contacts and sources:
Pia Snitkjær
University of Copenhagen

Citation: Fate of ethanol during cooking of liquid foods prepared with alcoholic beverages: Theory and experimental studies. Published in Food Chemistry: https://doi.org/10.1016/j.foodchem.2017.03.034

Get Ready for the 2017 Solar Eclipse

On Monday, August 21, 2017, our nation will be treated to a total eclipse of the sun. The eclipse will be visible -- weather permitting -- across all of North America. The whole continent will experience a partial eclipse lasting two to three hours. 

Halfway through the event, anyone within a 60 to 70 mile-wide path from Oregon to South Carolina will experience a total eclipse. During those brief moments when the moon completely blocks the sun's bright face for 2 + minutes, day will turn into night, making visible the otherwise hidden solar corona, the sun's outer atmosphere. Bright stars and planets will become visible as well. This is truly one of nature's most awesome sights. 
Total Solar Eclipse 2017 path USA map poster preview image
The eclipse provides a unique opportunity to study the sun, Earth, moon and their interaction because of the eclipse's long path over land coast to coast. Scientists will be able to take ground-based and airborne observations over a period of an hour and a half to complement the wealth of data provided by NASA assets. To learn all about the 2017 

Total Eclipse: https://eclipse2017.nasa.gov/  

Contacts and sources:

Protect Half the Earth: New Map of Life Shows How We Can Halt the World’s Sixth Great Extinction

A new study published in BioScience examines a bold new approach to halting the world’s extinction crisis through a strategy to protect 50 % of the Earth’s land mass. Researchers from the University Of Copenhagen are among the authors of the study.

Many vertebrate species have vanished over the past 5 decades or have become critically endangered and the rate of extinction is accelerating. If habitat conversion continues unabated, key ecosystems could collapse, disrupting the biosphere upon which we all—humans and wildlife—depend.

New map of the world’s 846 ecoregions

An interactive ecoregion map of the world with protection status by region is available at: http://ecoregions2017.appspot.com/

“Our paper shows that protecting half the Earth and saving the diversity of life is still feasible if we act now. The paper sets out an ambitious but achievable approach,” says lead author Dr. Eric Dinerstein.

The groundbreaking study uses a new map of the world’s 846 ecoregions, improving on a 2001 version and analysis that remains one of the most widely cited papers in the field of conservation biology.

Researchers from Department of Geosciences and Natural Resource Management at University of Copenhagen (UCPH) are among the authors of the study.

“We have in particular contributed to the work with a more detailed natural vegetation map of East Africa prepared together with the World Agroforestry Centre in Nairobi. It is extremely important to have targets and indicators based on verified knowledge to be able to measure what happen with nature” says senior researcher Jens-Peter Barnekow Lillesø.

Senior advisor Lars Graudal adds, “the state of the natural resource base is not only important for the purpose of conserving nature but also to design sustainable land management strategies for productive restoration of the more than 20% of the land surface that is degraded”.

The new study highlights 98 ecoregions (12 %) that already have at least half of the land areas protected for the conservation of nature. Another 313 ecoregions fall short of half-protected but have sufficient unaltered habitat remaining to protect the target.

Why 50 % protected area?

“In order to achieve comprehensive biodiversity conservation, many in the scientific community have empirically shown that an average target of 50% protected is required to sustain habitats and ecosystems. Currently, about 15% of the globe's land mass is somewhat protected; this number is not based on science and is insufficient," says co-author Dr. Reed Noss.

The authors call on advocates and leaders to protect half the terrestrial realm by 2050.

Contacts and sources:
Lars Graudal
University of Copenhagen

Citation: An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm https://academic.oup.com/biosci/article-lookup/doi/10.1093/biosci/bix014

Unexpectedly Stone-Dead Galaxy Still Rotates

A joint European-US study led by experts from Niels Bohr Institute (NBI) at University of Copenhagen, Denmark, reveals a rotating stellar disk à la the Milky Way in a stone-dead galaxy 10 billion light-years from Earth. This has never been shown before. The galaxy examined is an early version of elliptical-shaped galaxies.

Acting as a "natural telescope" in space, the gravity of the extremely massive foreground galaxy cluster MACS J2129-0741 magnifies, brightens, and distorts the far-distant background galaxy MACS2129-1, shown in the top box. The middle box is a blown-up view of the gravitationally lensed galaxy. In the bottom box is a reconstructed image, based on modeling, that shows what the galaxy would look like if the galaxy cluster were not present. The galaxy appears red because it is so distant that its light is shifted into the red part of the spectrum.

Credits: Science: NASA, ESA, and S. Toft (University of Copenhagen) Acknowledgment: NASA, ESA, M. Postman (STScI), and the CLASH team.

The finding is remarkable, as this pattern of stellar rotation in a dead galaxy strongly contradicts prevalent astrophysical theory regarding the formation of elliptical-shaped galaxies shortly after the Big Bang 13.7 billion years ago.

The galaxy has been named MACS2129-1, and the upcoming issue of the journal Nature will run a scientific article describing how the researchers detected the galaxy and how they managed to unravel some of its secrets.

"MACS 2129-1 is three times heavier than the Milky Way, our own galaxy - but only half the size. So MACS2129-1 is extremely compact", says study leader Sune Toft, astrophysicist at Dark Cosmology Centre at NBI in Copenhagen.

'Speed limits' also seem to differ somewhat between MACS2129-1 and the Milky Way, Sune Toft adds: "We were able to establish that the stars in MACS2129-1 rotate in circles around the center of the galaxy at a speed of over 500 km per second, more than twice as fast as stars rotate in the Milky Way".


Galaxies are stellar systems in space and astronomers distinguish between two main types: disk-shaped spiral galaxies, e.g. the Milky Way, and elliptical-shaped galaxies. One of the distinct differences between the two main types being that while the disk-shaped galaxies still make new stars by transforming gas, the elliptical-shaped stopped doing this long ago - which is why the latter are deemed 'dead'.

This artist's concept shows what the young, dead, disk galaxy MACS2129-1, right, would look like when compared with the Milky Way galaxy, left. 
Credits: NASA, ESA, and Z. Levy (STScI)

Furthermore the stellar motions differs markedly between the two main types: In the Milky Way and in other disk-shaped galaxies stars rotate with a regularity that is predictable - whereas stellar motions in elliptic-shaped galaxies can be seen as rather more chaotic, says Sune Toft: "Here the stars seem to be all over the place, to move in all directions. And that was what we expected to find when we took a closer look at MACS2129-1".

Why elliptic-shaped galaxies stopped producing new stars way back in the history of the universe has long puzzled astrophysicists. The prevalent theory speculates that collisions between galaxies in some cases may have provoked a sort of over-production in certain galaxies - because all available gas was compressed in their center and transformed to new stars. Whereupon these elliptical-shaped galaxies ceased stellar production - and 'died'.

With MACS2129-1, however, things are different. Albeit it can be said with certainty that the galaxy is not producing new stars - and therefore can safely be considered stone-dead - its existing stars are nevertheless distributed in a rotating disc. Exactly as can be seen in the Milky Way!

A wider view of galaxy cluster MACS J2129-0741, located in the constellation Aquarius.

Natural lens

Can this atypical system of stellar rotation observed in MACS2129-1 be interpreted as a form of 'prototype' representing an early stage in the development of elliptic-shaped galaxies?

"Not at this point", says Sune Toft: "Before we can approach an answer to that question we have to study other 'dead' elliptic-shaped galaxies of the same age - and we have started this work".

Sune Toft and his collaborators had access to the Hubble-telescope in space as well as the Earth-based Very Large Telescope (VLT) in Chile - yet they struggled to get information about MACS2129-1.

In the end success was secured by the fact that the stone-dead galaxy was positioned behind a foreground cluster of other galaxies - a cluster which functioned as a 'natural lens' by amplifying as well as enlarging the image of MACS2129-1. And that made it possible for the researchers via Hubble and VLT to study in detail the distribution of stars in the galaxy as well as the patterns of stellar rotation, says Sune Toft: "Thanks to the natural lens we were able to to gaze into the core of this galaxy, which would otherwise have appeared not much larger than a star to our telescopes.

This annotated image shows the size, scale, distance, filters, and compass for galaxy cluster MACS J2129-0741 and the gravitationally lensed galaxy MACS2129-1.

Credits: Science: NASA, ESA, and S. Toft (University of Copenhagen) Acknowledgment: NASA, ESA, M. Postman (STScI), and the CLASH team.
Further studies of the cosmological origin of elliptic-shaped galaxies will figure prominently when Cosmic Dawn Center opens later this year. This research centre - financed by Danish National Research Foundation with a grant of 66 million DKR - will be jointly run by NBI and DTU Space, a faculty of Technical University of Denmark (DTU), with Sune Toft appointed scientific director.

Beginning next year Sune Toft and his colleagues will gain access to equipment of hitherto unknown strength and precision when ESA, European Space Agency, CSA, Canadian Space Agency and NASA, the US space organization, put James Webb Space Telescope into orbit 1,5 million km from Earth.

The telescope which is much stronger than Hubble - its predecessor - will operate in a very cold and dark environment ideal for conducting observations, says Sune Toft:

"The Webb-telescope is designed to detect infrared light from the very first stars and galaxies. In theory it will make it possible for scientist to study what happened when the elliptic-shaped galaxies formed - and when they died. And because scientists from both NBI and DTU Space helped build some of the instruments on board the James Webb Space Telescope, Cosmic Dawn Center is guaranteed fast access to the telescope once it is in orbit".

Contacts and sources:
Sune Toft, Associate Professor, Dark Cosmology Centre, DAWN, Niels Bohr Institute, University of Copenhagen.

How Fish Evolved onto Land: 'It's Like A Snake on the Outside, but a Fish on the Inside'

"It's like a snake on the outside, but a fish on the inside."

The fossil of an early snake-like animal - called Lethiscus stocki - has kept its evolutionary secrets for the last 340-million years.

Now, an international team of researchers, led by the University of Calgary, has revealed new insights into the ancient Scottish fossil that dramatically challenge
our understanding of the early evolution of tetrapods, or four-limbed animals with backbones.

University of Calgary Professor Jason Anderson, right, and doctoral student Jason Pardo published a paper in Nature about new insights into the ancient Scottish fossil called Lethiscus stocki.

Photo by Riley Brandt, University of Calgary

Their findings have just been published in the prestigious international research journal Nature. "It forces a radical rethink of what evolution was capable of among the first tetrapods," said project lead Jason Anderson, a paleontologist and Professor at the University of Calgary Faculty of Veterinary Medicine (UCVM).

Before this study, ancient tetrapods--the ancestors of humans and other modern-day vertebrates - were thought to have evolved very slowly from fish to animals with limbs.

"We used to think that the fin-to-limb transition was a slow evolution to becoming gradually less fish like," he said. "But Lethiscus shows immediate, and dramatic, evolutionary experimentation. The lineage shrunk in size, and lost limbs almost immediately after they first evolved. It's like a snake on the outside but a fish on the inside."

Lethicus' secrets revealed with 3D medical imaging

Using micro-computer tomography (CT) scanners and advanced computing software, Anderson and study lead author Jason Pardo, a doctoral student supervised by Anderson, got a close look at the internal anatomy of the fossilized Lethiscus. After reconstructing CT scans its entire skull was revealed, with extraordinary results.

"The anatomy didn't fit with our expectations," explains Pardo. "Many body structures didn't make sense in the context of amphibian or reptile anatomy." But the anatomy did make sense when it was compared to early fish.

"We could see the entirety of the skull. We could see where the brain was, the inner ear cavities. It was all extremely fish-like," explains Pardo, outlining anatomy that's common in fish but unknown in tetrapods except in the very first. The anatomy of the paddlefish, a modern fish with many primitive features, became a model for certain aspects of Lethiscus' anatomy.

Changing position on the tetrapod 'family tree'

When they included this new anatomical information into an analysis of its relationship to other animals, Lethiscus moved its position on the 'family tree', dropping into the earliest stages of the fin-to-limb transition. "It's a very satisfying result, having them among other animals that lived at the same time," says Anderson.

The results match better with the sequence of evolution implied by the geologic record. "Lethiscus also has broad impacts on evolutionary biology and people doing molecular clock reproductions of modern animals," says Anderson. "They use fossils to calibrate the molecular clock. By removing Lethiscus from the immediate ancestry of modern tetrapods, it changes the calibration date used in those analyses."

Contacts and sources:
Collene Ferguson
University of Calgary

Wednesday, June 21, 2017

Aluminum Batteries That “Drink” Seawater Could Power Long-Range Underwater Vehicles

The long range of airborne drones helps them perform critical tasks in the skies. Now MIT spinout Open Water Power (OWP) aims to greatly improve the range of unpiloted underwater vehicles (UUVs), helping them better perform in a range of applications under the sea.

Recently acquired by major tech firm L3 Technologies, OWP has developed a novel aluminum-water power system that’s safer and more durable, and that gives UUVs a tenfold increase in range over traditional lithium-ion batteries used for the same applications.

The power systems could find a wide range of uses, including helping UUVs dive deeper, for longer periods of time, into the ocean’s abyss to explore ship wreckages, map the ocean floor, and conduct research. They could also be used for long-range oil prospecting out at sea and various military applications.

Open Water Power’s battery that "drinks" in sea water to operate is safer and cheaper, and provides a tenfold increase in range, over traditional lithium-ion batteries used for unpiloted underwater vehicles. The power system consists of an alloyed aluminum anode, an alloyed cathode, and an alkaline electrolyte positioned between the electrodes. Components are only activated when flooded with water. Once the aluminum anode corrodes, it can be replaced at low cost.
Courtesy of Open Water Power

With the acquisition, OWP now aims to ramp up development of its power systems, not just for UUVs, but also for various ocean-floor monitoring systems, sonar buoy systems, and other marine-research devices.

OWP is currently working with the U.S. Navy to replace batteries in acoustic sensors designed to detect enemy submarines. This summer, the startup will launch a pilot with Riptide Autonomous Solutions, which will use the UUVs for underwater surveys. Currently, Riptide’s UUVs travel roughly 100 nautical miles in one go, but the company hopes OWP can increase that distance to 1,000 nautical miles.

“Everything people want to do underwater should get a lot easier,” says co-inventor Ian Salmon McKay ’12, SM ’13, who co-founded OWP with fellow mechanical engineering graduate Thomas Milnes PhD ’13 and Ruaridh Macdonald '12, SM '14, who will earn his PhD in nuclear engineering this year. “We’re off to conquer the oceans.”

“Drinking” sea water for power

Most UUVs use lithium-based batteries, which have several issues. They’re known to catch fire, for one thing, so UUV-sized batteries are generally not shippable by air. Also, their energy density is limited, meaning expensive service ships chaperone UUVs to sea, recharging the batteries as necessary. And the batteries need to be encased in expensive metal pressure vessels. In short, they’re rather short-lived and unsafe.

In contrast, OWP’s power system is safer, cheaper, and longer-lasting. It consists of a alloyed aluminum, a cathode alloyed with a combination of elements (primarily nickel), and an alkaline electrolyte that’s positioned between the electrodes.

When a UUV equipped with the power system is placed in the ocean, sea water is pulled into the battery, and is split at the cathode into hydroxide anions and hydrogen gas. The hydroxide anions interact with the aluminum anode, creating aluminum hydroxide and releasing electrons. Those electrons travel back toward the cathode, donating energy to a circuit along the way to begin the cycle anew. Both the aluminum hydroxide and hydrogen gas are jettisoned as harmless waste.

Components are only activated when flooded with water. Once the aluminum anode corrodes, it can be replaced at low cost.

Think of the power system as type of underwater engine, where water is the oxidizer feeding the chemical reactions, instead of the air used by car engines, McKay says. “Our power system can drink sea water and discard waste products,” he says. “But that exhaust is not harmful, compared to exhaust of terrestrial engines.”

With the aluminum-based power system, UUVs can launch from shore and don’t need service ships, opening up new opportunities and dropping costs. With oil prospecting, for example, UUVs currently used to explore the Gulf of Mexico need to hug the shores, covering only a few pipeline assets. OWP-powered UUVs could cover hundreds of miles and return before needing a new power system, covering all available pipeline assets.

Consider also the Malaysian Airlines crash in 2014, where UUVs were recruited to search areas that were infeasible for equipment on the other vessels, McKay says. “In looking for the debris, a sizeable amount of the power budget for missions like that is used descending to depth and ascending back to the surface, so their working time on the sea floor is very limited,” he says. “Our power system will improve on that.”

Nailing the design

The OWP technology started as the co-founders’ side project, which was modified throughout two MIT classes and a lab. In 2011, McKay joined 2.013/2.014 (Engineering System Design/Development) taught by MIT professor of mechanical engineering Douglas Hart, a seasoned hardware entrepreneur who co-founded Brontes Technologies and Lantos Technologies. Milnes, who was previously a systems engineer at Brontes and co-founded Viztu Technologies, was Hart’s teaching assistant.

The class was charged with developing an alternate power source for UUVs. McKay gambled on an energy-dense but challenging element: aluminum. One major challenge with aluminum batteries is that certain chemical issues make it difficult to donate electrons to a circuit. Additionally, the product of the reactions, the aluminum hydroxide, sticks to the electrode’s surface, inhibiting further reaction. Continuing the work in 10.625 (Electrochemical Energy Conversion and Storage), taught by materials science Professor Yang Shao-Horn, the W. M. Keck Professor of Energy, McKay was able to overcome the first challenge by making a gallium-rich alloyed aluminum anode that successfully donated electrons, but it corroded very quickly.

Seeing potential in the battery, Milnes joined McKay in further developing the battery as a side project. The two briefly moved operations to the lab of Evelyn Wang, the Gail E. Kendall Professor of Mechanical Engineering. There, they began developing electrolytes and alloys that inhibit parasitic corrosion processes and prevent that aluminum hydroxide layer from forming on the anode.

Setting up shop at Greentown Labs in Somerville, Massachusetts, in 2013 — where the company still operates with about 10 employees — OWP further refined the power system’s design. Today, that power system uses a pump to circulate the electrolyte, scooping up unwanted aluminum hydroxide on the anode and dumping it onto a custom precipitation trap. When saturated, the traps with the waste are ejected and replaced automatically. The electrolyte prevents marine organisms from growing inside the power system.

Now OWP’s chief science officer, McKay says the startup owes much of its success to MIT’s atmosphere of innovation, where many of his professors readily offered technical and entrepreneurial advice and allowed him to work on extracurricular projects.

“It takes a village,” McKay says. “Those classes and that lab are where the idea took shape. People at MIT were doing strong science for science’s sake, but everyone was keenly aware of the possibility of bringing technologies to market. People were always having those great ‘What if?’ conversations — I probably had three to four different startup ideas in various stages of gestation at any given time, and so did all my friends. It was an environment that encouraged the playful exchange of ideas, and encouraged people to take on side projects with real prizes in mind.”

Contacts and sources:
Rob Matheson
Massachusetts Institute of Technology

New Paint Turns Your Walls into Endless Power Sources

Researchers have developed a solar paint that can absorb water vapour and split it to generate hydrogen – the cleanest source of energy.

The paint contains a newly developed compound that acts like silica gel, which is used in sachets to absorb moisture and keep food, medicines and electronics fresh and dry.

But unlike silica gel, the new material, synthetic molybdenum-sulphide, also acts as a semi-conductor and catalyses the splitting of water atoms into hydrogen and oxygen.

RMIT lead researcher Dr Torben Daeneke said: “We found that mixing the compound with titanium oxide particles leads to a sunlight-absorbing paint that produces hydrogen fuel from solar energy and moist air.
Credit: RMIT

“Titanium oxide is the white pigment that is already commonly used in wall paint, meaning that the simple addition of the new material can convert a brick wall into energy harvesting and fuel production real estate.

“Our new development has a big range of advantages,” he said. “There’s no need for clean or filtered water to feed the system. Any place that has water vapour in the air, even remote areas far from water, can produce fuel.”

His colleague, Distinguished Professor Kourosh Kalantar-zadeh, said hydrogen was the cleanest source of energy and could be used in fuel cells as well as conventional combustion engines as an alternative to fossil fuels.

Video: Peter Clarke

“This system can also be used in very dry but hot climates near oceans. The sea water is evaporated by the hot sunlight and the vapour can then be absorbed to produce fuel.

“This is an extraordinary concept – making fuel from the sun and water vapour in the air.”

The research has been published as “Surface Water Dependent Properties of Sulfur Rich Molybdenum Sulphides – Electrolyteless Gas Phase Water Splitting” in ACS Nano, a journal of the American Chemical Society.

Distinguished Professor Kourosh Kalantar-zadeh and Dr Torben Daeneke with a pot of solar paint and a piece of glass with the paint applied.

Contacts and sources: 
David Glanz
RMIT University

The DOI is 10.1021/acsnano.7b01632. 

Ethanol Made from Water and Carbon Dioxide, No Plants Needed

Most cars and trucks in the United States run on a blend of 90 percent gasoline and 10 percent ethanol, a renewable fuel made primarily from fermented corn. But producing the 14 billion gallons of ethanol consumed annually by American drivers requires millions of acres of farmland.

New research reveals that copper can turn carbon dioxide into ethanol without using corn or other plants.

A recent discovery by Stanford University scientists could lead to a new, more sustainable way to make ethanol without corn or other crops. This technology has three basic components: water, carbon dioxide and electricity delivered through a copper catalyst. The results are published in Proceedings of the National Academy of Sciences.

Associate Professor Thomas Jaramillo (left) and SLAC scientist Christopher Hahn have demonstrated the feasibility of designing copper catalysts that convert carbon dioxide into ethanol without corn or other crops.

Image credit: Mark Shwartz/Stanford University

“One of our long-range goals is to produce renewable ethanol in a way that doesn’t impact the global food supply,” said study principal investigator Thomas Jaramillo, an associate professor of chemical engineering at Stanford and of photon science at the SLAC National Accelerator Laboratory.

“Copper is one of the few catalysts that can produce ethanol at room temperature,” he said. “You just feed it electricity, water and carbon dioxide, and it makes ethanol. The problem is that it also makes 15 other compounds simultaneously, including lower-value products like methane and carbon monoxide. Separating those products would be an expensive process and require a lot of energy.”

Scientists would like to design copper catalysts that selectively convert carbon dioxide into higher-value chemicals and fuels, like ethanol and propanol, with few or no byproducts. But first they need a clear understanding of how these catalysts actually work. That’s where the recent findings come in.
Copper crystals

For the PNAS study, the Stanford team chose three samples of crystalline copper, known as copper (100), copper (111) and copper (751). Scientists use these numbers to describe the surface geometries of single crystals.

Stanford scientists have designed a large copper catalyst that produces ethanol from carbon dioxide and water.

Image credit: Mark Shwartz/Stanford University

“Copper (100), (111) and (751) look virtually identical but have major differences in the way their atoms are arranged on the surface,” said Christopher Hahn, an associate staff scientist at SLAC and co-lead lead author of the study. “The essence of our work is to understand how these different facets of copper affect electrocatalytic performance.”

In previous studies, scientists had created single-crystal copper electrodes just 1-square millimeter in size. For this study, Hahn and his co-workers at SLAC developed a novel way to grow single crystal-like copper on top of large wafers of silicon and sapphire. This approach resulted in films of each form of copper with a 6-square centimeter surface, 600 times bigger than typical single crystals.
Catalytic performance

To compare electrocatalytic performance, the researchers placed the three large electrodes in water, exposed them to carbon dioxide gas and applied a potential to generate an electric current.

The results were clear. When the team applied a specific voltage, the electrodes made of copper (751) were far more selective to liquid products, such as ethanol and propanol, than those made of copper (100) or (111).

SLAC scientist Christopher Hahn sees his reflection in a shiny copper catalyst  that converts carbon dioxide into ethanol.

Image credit: Mark Shwartz

Ultimately, the Stanford team would like to develop a technology capable of selectively producing carbon-neutral fuels and chemicals at an industrial scale.

“The eye on the prize is to create better catalysts that have game-changing potential by taking carbon dioxide as a feedstock and converting it into much more valuable products using renewable electricity or sunlight directly,” Jaramillo said. “We plan to use this method on nickel and other metals to further understand the chemistry at the surface. We think this study is an important piece of the puzzle and will open up whole new avenues of research for the community.”

Jaramillo also serves as deputy director of the SUNCAT Center for Interface Science and Catalysis, a partnership of the Stanford School of Engineering and SLAC. Study authors include co-lead author Toru Hatsukade, Drew Higgins and Stephanie Nitopi at Stanford; Youn-Geun Kim at SLAC; and Jack Baricuatro and Manuel Soriaga at the California Institute of Technology.

Contacts and sources: 
Mark Shwartz
Stanford University

The Drone with X-Ray Eyes See Through Walls, Makes 3-D Images

Researchers at UC Santa Barbara professor Yasamin Mostofi’s lab have given the first demonstration of three-dimensional imaging of objects through walls using ordinary wireless signal. The technique, which involves two drones working in tandem, could have a variety of applications, such as emergency search-and-rescue, archaeological discovery and structural monitoring.

“Our proposed approach has enabled unmanned aerial vehicles to image details through walls in 3D with only WiFi signals,” said Mostofi, a professor of electrical and computer engineering at UCSB. “This approach utilizes only WiFi RSSI measurements, does not require any prior measurements in the area of interest and does not need objects to move to be imaged.”

Researchers at UCSB develop a method for three-dimensional through-wall imaging using drones and WiFi signal

The proposed methodology and experimental results appeared in the Association for Computing Machinery/Institute of Electrical and Electronics Engineers International Conference on Information Processing in Sensor Networks (IPSN).

In their experiment, two autonomous octocopters take off and fly outside an enclosed, four-sided brick house whose interior is unknown to the drones. While in flight, one copter continuously transmits a WiFi signal, the received power of which is measured by the other copter for the purpose of 3D imaging.

After traversing a few proposed routes, the copters utilize the imaging methodology developed by the researchers to reveal the area behind the walls and generate 3D high-resolution images of the objects inside. The 3D image closely matches the actual area.

“High-resolution 3D imaging through walls, such as brick walls or concrete walls, is very challenging, and the main motivation for the proposed approach,” said Chitra R. Karanam, the lead Ph.D. student on this project.

Credit: UC Santa Barbara

This development builds on previous work in the Mostofi Lab, which has pioneered sensing and imaging with everyday radio frequency signals such as WiFi. The lab published the first experimental demonstration of imaging with only WiFi in 2010, followed by several other works on this subject.

“However, enabling 3D through-wall imaging of real areas is considerably more challenging due to the considerable increase in the number of unknowns,” said Mostofi. While their previous 2D method utilized ground-based robots working in tandem, the success of the 3D experiments is due to the copters’ ability to approach the area from several angles, as well as to the new proposed methodology developed by her lab.

The researchers’ approach to enabling 3D through-wall imaging utilizes four tightly integrated key components. First, they proposed robotic paths that can capture the spatial variations in all the three dimensions as much as possible, while maintaining the efficiency of the operation.

Second, they modeled the three dimensional unknown area of interest as a Markov Random Field to capture the spatial dependencies, and utilized a graph-based belief propagation approach to update the imaging decision of each voxel (the smallest unit of a 3D image) based on the decisions of the neighboring voxels.

Third, in order to approximate the interaction of the transmitted wave with the area of interest, they used a linear wave model.

Finally, they took advantage of the compressibility of the information content to image the area with a very small number of WiFi measurements (less than 4 percent). It is noteworthy that their setup consists solely of off-the-shelf units such as copters, WiFi transceivers and Tango tablets.

Contacts and sources: 
Sonia Fernandez
UC Santa Barbara

The Most Mysterious Amphibian Alive Today Revealed

Researchers have determined that the fossils of an extinct species from the Triassic Period are the long-missing link that connects amphibians to wormlike creatures with a backbone and two rows of sharp teeth.  

The discovery fills a significant gap in the evolutionary history of frogs, toads and other amphibians.

Named Chinlestegophis jenkinsi, the newfound fossil is the oldest relative of the most mysterious group of amphibians: caecilians. Today, these limbless, colorful serpentine carnivores live underground and range in size from 6 inches to 5 feet.

Chinlestegophis jenkinsi, a tiny subterranean carnivore, is an ancient relative of frogs and salamanders. 
Illustration of what the Chinlestegophis jenkinsi could have looked like
Illustration/Jorge Gonzalez

“Our textbook-changing discovery will require paleontologists to re-evaluate the timing of the origin of modern amphibian groups and how they evolved,” said Adam Huttenlocker, senior author of the study and an assistant professor in the Department of Integrative Anatomical Sciences at the Keck School of Medicine of USC.

The study, published in Proceedings of the National Academy of Sciences on June 19, expands the known history of frogs, toads and salamanders by at least 15 million years and closes a major gap in early caecilian evolution by connecting them to stereospondyls, animals with toilet-seat heads that were the most diverse amphibian group during the Triassic era more than 200 million years ago.

Scientists previously believed the story of the stereospondyl order was a dead-end because, although widespread during the Triassic Period, the animals were believed to be unrelated to anything alive today. The two recently discovered fossils dispel that theory and suggest that the amphibian lineage of today evolved from a common ancestor some 315 million years ago.

“Caecilians are hard to find in the fossil record because most are so small,” Huttenlocker said. “Chinlestegophis jenkinsi still preserves a lot of the primitive morphology that is shared with other Triassic amphibians, namely their four legs.”

Today’s caecilians are limbless, colorful serpentine carnivores that live underground and range in size from 6 inches to 5 feet.


Before C. jenkinsi, scientists had found only two other caecilian fossils from the Age of Dinosaurs and — unlike the two recently unearthed — those came later and had reduced limbs, more closely resembling their contemporary living relatives.

“It’s possible that the things that frog and salamander tissue can do when it comes to scarless healing are also present in human DNA but may be turned off,” said Jason Pardo, lead author of the study and a doctoral candidate in the Faculty of Veterinary Medicine at the University of Calgary in Alberta, Canada. “Because humans are also vertebrates, we enhance our understanding of our own evolutionary history and genetic heritage when we gain understanding of the amphibian lineage.”

Solving mysteries in vertebrate evolution

There are currently fewer than 200 species of caecilians, which live in the wet, tropical regions of South America, Africa and Southeast Asia. But the two ancient fossil amphibians found in the late 1990s by Bryan Small, study co-author and a research associate at Texas Tech University, were preserved in the fossilized burrows of Eagle County, Colo.

The paleontologists used 3-D X-rays to reassemble the fossil remains of two C. jenkinsi specimens. Parts of a skull, spinal column, ribs, shoulder and legs survived in the fossils of the first specimen. Only the skull was distinguishable in the second specimen.

“Twenty to 30 years ago, we weren’t even sure of the origins of birds,” Pardo said. “Now we are solving some of the final remaining mysteries when it comes to what sorts of animals the major vertebrate groups evolved from. Caecilians, turtles and some fish are the only major vertebrate groups that paleontologists still have questions about.”

Characteristics of the ancient caecilian

The burrows these fossils were preserved in were almost 2 inches wide, meaning they could not have been very big. Their bullet-shaped skulls were just under 1 inch long, so the ancient caecilian was probably about the size of a small salamander, Huttenlocker said.

The length of the animal is unknown because researchers do not have the full fossil remains of the animal, but Pardo estimates that the ancient caecilian was between 6 inches to a foot long. As a small carnivore, it probably ate insects.

Its eyes would have been functional but tiny. Some of today’s caecilians do not have eyes or they are hidden under moist skin.

During the summer, this central Colorado area would have been scorching, which is probably why these subterranean animals thrived. Big dinosaurs like early relatives of the Tyrannosaurus rex and Triceratops could not have existed in such conditions, Huttenlocker said.

“The ancient caecilians lived in these burrows deep in the soil down to about the level of the water table so that they could keep wet and avoid the extreme aridity from the dry season,” Huttenlocker said. “I’m going back to Colorado this summer and hope to find more animals with more complete skeletons. We’ll find one. This is just the initial report.”

Field work for the study was supported by permits from the U.S. Department of the Interior’s Bureau of Land Management (BLM-CO-49819 & CO-49819d and BLM-CO-76493 & BLM-CO-78401).

Contacts and sources:
Zen Vuong
University of Southern California