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Wednesday, March 22, 2017

Gluten Free Rice-Flour Bread Could Revolutionize Global Bread Production

100% natural, 100% gluten free - get ready for the battle of the grain.

Hiroshima University researchers have resolved the science behind a new bread-baking recipe. The method for making gluten-free bread, developed by Japan’s National Agriculture and Food Research Organization, NARO - uses rice-flour to produce bread with a similar consistency and volume to traditional wheat-flour loaves.

While rice-flour breads are not new, up until now their consistencies have either lacked the familiar bubble structure and volume found in wheat-flour bread – or this bubble structure has been artificially induced through additives.

Successful Rice Flour Bread
Credit: Hiroshima University 

This new rice bread is 100% natural, and importantly has a similar consistency expected by consumers used to wheat breads. This gluten-free alternative should appeal to celiac sufferers who can’t consume gluten, and to people who wish to avoid gluten in their diets.

How it works

Wheat-flour bread’s familiar texture is down to gluten’s ability to form a flexible matrix. This matrix stabilizes the thin dough/bread walls that form between CO2 bubbles released by fermenting yeast. It also enables bread to “rise” in response to increasing CO2 levels during the baking process.

Rice flour does not contain gluten so how are these vital bread characteristics achieved in this new bread recipe?

The secret lies in the processing of the rice flour used. Not all rice flours produce a satisfactory batch, hence why this simple technique has remained undiscovered for so long! NARO found that rice flour produced by a specific type of wet milling was the key.

Using this wet-milled flour to make bread, they observed the microstructure of the fermenting batter (rice flour does not form dough), and the resulting loaf - both contained bubbles coated in uniform undamaged starch particles in a “stone wall” arrangement.

Effect of undamaged starch in reducing water tension
Credit: Hiroshima University

When Hiroshima University researchers investigated this ingredient, they found it possessed amazingly novel properties not seen in rice-flour before – and these were down to the undamaged starch particles that resulted from its specific milling technique.

These stable “stone walls” apparently form due to the surface activity demonstrated by undamaged starch granules. It appears these granules are able to lower the surface tension of water and so reduce the tendency of the formed bubble walls to collapse! Other rice-flours tested, consisting of damaged starch, did not have the same water-tension lowering effect. They were thus devoid of these stable bubbles, and attempts to make bread with them fell flat.

Another factor hypothesized for undamaged starch bubble-stability in successful bread production is the uniform hydrophobicity of the similar sized granules - leading to their confinement to the interface between damp gaseous air pockets and the liquid batter.

This tightknit “stone wall” arrangement thus allows bubbles to grow and expand as CO2 levels increase within leading to successful voluminous bread.

Great Potential

Should producers see the benefits of moving to gluten-free rice flour for bread production it could conceivably shift the focus of global grain production from the prairies and steppes of the world to the paddy fields of Asia.

Hiroyuki Yano (NARO) and Masumi Villeneuve (Hiroshima University)
Credit: Hiroshima University 

This would contribute to increased rice exports at a time when consumption of the staple has decreased with the adoption of western dietary habits – including ironically the eating of more bread!

From a food science point of view - this newly discovered example of a food swelling mechanism could lead to the development of new unconceived foods with unique and exciting properties.

Contacts and sources:
Hiroshima University

Citation: Development of gluten-free rice bread: Pickering stabilization as a possible batter-swelling mechanism

Hiroyuki Yano, Akiko Fukui, Keiko Kajiwara, Isao Kobayashi, Koh-ichi Yoza, Akiyoshi Satake, Masumi Villeneuve Available online 1 December 2016

Archaeologists Find Prostate Stones, Shed New Light on 'Modern' Medical Problem

Archaeologists have helped solve a centuries’ old medical mystery which could change the way doctors today view the common condition of prostate stones.

An international team of researchers, including experts at Durham University, used neutron beam technology to identify three stone-like objects found during excavations of a prehistoric grave in Central Sudan.

They discovered that the mysterious objects were prostate stones – a condition previously thought to be exclusive to the modern era.

The find proves that far from being a modern condition, prostate stones also affected prehistoric men, even though their lifestyle and diet were significantly different to our own.

Prostate stone found in Central Sudan. 

Credit: D. Usai et al

The researchers hope their find might now provide medical researchers with the opportunity to learn more about what causes the disease.

The findings are published in the journal PLOS One.

“First known evidence”

Research co-author Dr Tina Jakob, in Durham’s Department of Archaeology, said: “Although bladder stones have been discovered at other archaeological sites, this is the first known evidence of severe prostate calcification affecting men as early as 10,000 BC.

“This is a truly remarkable discovery and will change the way we look at prostatic stones as a modern medical phenomenon.”

While excavating a cemetery in Central Sudan in 2013, a team of archaeologists from the UK and Italy unearthed a pre-Mesolithic burial with an unusual feature.

Three stone-like objects were found within the pelvic area of an adult male and it was initially thought they could be kidney, bladder or gall stones.

The stones were oval and irregular in shape with diameters ranging between 26mm and 30mm, weighing between 12g and 15g.

Common condition

Nowadays, prostatic stones are a common condition for modern men, affecting about 75 per cent of the middle-aged population – although most stones only grow to a few millimetres in diameter before being treated.

Extensive tests were carried out on the stones using the Science and Technology Facilities Council’s ISIS facility, the UK’s centre for studying the properties of materials on the atomic scale.

By measuring how neutrons were scattered by the stone sample, the researchers built up a picture of its mineral nature.

They were then able to identify the objects as prostate stones. Although archaeologists cannot say whether these stones killed the man, they were large enough to cause intense pain and affect his quality of life.

Neutron beam

Dr Antonella Scherillo, the lead scientist operating the neutron beam at ISIS, said: “We were delighted to be able to help the archaeologists find out the nature of these unusual objects.

“Using ISIS’ powerful neutron beam we were able to analyse the phase composition of the object without causing any damage.

“This is how we found out the stones were in fact prostate stones – a remarkable discovery considering the age of the burial site.”

Radiocarbon dating

Until now, the earliest possible discovery of calculi – a hard mass formed by minerals in the body – was from an Italian grave from around 6,500 BC.

The cemetery of Al Khiday, where the individual with the prostate stones was found, is located in Central Sudan on the left bank of the White Nile, and is home to 190 graves of various ages.

Archaeologists were able to deduce the age of these remains by the style of burial and a detailed study of the mineral deposition of the bones, as well as radiocarbon dating the rock and soil in the burial site, which suggested the male lived around 10,000 BC.

Universe's Ultraviolet Background May Provide Clues About Missing Galaxies

Astronomers have developed a way to detect the ultraviolet (UV) background of the Universe, which could help explain why there are so few small galaxies in the cosmos.

UV radiation is invisible but shows up as visible red light when it interacts with gas.

An international team of researchers led by Durham University, UK, has now found a way to measure it using instruments on Earth.

The researchers said their method can be used to measure the evolution of the UV background through cosmic time, mapping how and when it suppresses the formation of small galaxies.

The study could also help produce more accurate computer simulations of the evolution of the Universe.

 This movie follows the formation of galaxies with cosmic time, illustrating how ultraviolet (UV) radiation from other galaxies and from quasars suppresses the formation of stars inside small galaxies near to large galaxies similar to the Milky Way and Andromeda. The left panel shows a simulation that includes such diffuse UV radiation as in the real universe, where fewer smaller galaxies form. For comparison, the right panel shows what would happen in the absence of such radiation, with more small galaxies forming.
Credit:  University of Durham, S. McAlpine/S. Berry

The findings are published today (Wednesday, 22 March) in the journal Monthly Notices of the Royal Astronomical Society.

UV radiation - a type of radiation also given out by our Sun - is found throughout the Universe and strips smaller galaxies of the gas that forms stars, effectively stunting their growth.

It is believed to be the reason why some larger galaxies like our Milky Way don't have many smaller companion galaxies.

Simulations show that there should be more small galaxies in the Universe, but UV radiation essentially stopped them from developing by depriving them of the gas they need to form stars.

Larger galaxies like the Milky Way were able to withstand this cosmic blast because of the thick gas clouds surrounding them.

Galaxy UGC 7321 is surrounded by hydrogen gas, and as this gas is irradiated with UV radiation, it emits a diffuse red glow through a process known as fluorescence. This image shows the light emitted by stars inside the galaxy, surrounded by a red ring that represents the fluorescent emission induced by the UV radiation.

Credit: M. Fumagalli/T. Theuns/S. Berry

Lead author Dr Michele Fumagalli, in the Institute for Computational Cosmology and Centre for Extragalactic Astronomy, at Durham University, said: "Massive stars and supermassive black holes produce huge amounts of ultraviolet radiation, and their combined radiation builds-up this ultraviolet background.

"This UV radiation excites the gas in the Universe, causing it to emit red light in a similar way that the gas inside a fluorescent bulb is excited to produce visible light.

"Our research means we now have the ability to measure and map this UV radiation which will help us to further refine models of galaxy formation."

Co-author Professor Simon Morris, in the Centre for Extragalactic Astronomy, Durham University, added: "Ultimately this could help us learn more about the evolution of the Universe and why there are so few small galaxies."

Researchers pointed the Multi Unit Spectroscopic Explorer (MUSE), an instrument of the European Southern Observatory's Very-Large Telescope, in Chile, at the galaxy UGC 7321, which lies at a distance of 30 million light years from Earth.

Colour image of the starlight emitted by a nearby spiral galaxy called UGC 7321. Stars in this galaxy lie in a disc, similar to that of our galaxy, the Milky Way. We see this disc nearly perfectly edge-on. Other sources in the image are foreground or background objects (galaxies and stars), unrelated to galaxy UGC 7321.
Credit: M. Fumagalli/T. Theuns/S. Berry

MUSE provides a spectrum, or band of colours, for each pixel in the image allowing the researchers to map the red light produced by the UV radiation illuminating the gas in that galaxy.

The research, funded in the UK by the Science and Technology Facilities Council, could also help scientists predict the temperature of the cosmic gas with more accuracy.

Co-author Professor Tom Theuns, in Durham University's Institute for Computational Cosmology, said: "Ultraviolet radiation heats the cosmic gas to temperatures higher than that of the surface of the Sun.

"Such hot gas will not cool to make stars in small galaxies. This explains why there are so few small galaxies in the Universe, and also why our Milky Way has so few small satellite galaxies."

Contacts and sources:
Leighton Kitson
Durham University

430 Million-Year-Old Lobster-Like’ Fossil Named in Honor of Sir David Attenborough

An international team of scientists led by the University of Leicester has discovered a new 430 million-year-old fossil and has named it in honour of Sir David Attenborough - who grew up on the University campus.

The fossil is described as 'exceptionally well preserved in three-dimensions' - complete with the soft-parts of the animal, such as legs, eyes and very delicate antennae. The fossil has been determined as an ancient crustacean new to science - a distant relative of the living lobsters, shrimps and crabs. There are about 40,000 crustacean species known today.

An international team of scientists led by the University of Leicester has discovered a new 430 million-year-old fossil and has named it in honor of Sir David Attenborough - who grew up on the University campus.

Credit: © Siveter et al

The find comes from volcanic ash deposits that accumulated in a marine setting in what is now Herefordshire in the Welsh Borderland.

Professor David Siveter of the Department of Geology at the University of Leicester made the discovery working alongside researchers from the Universities of Oxford, Imperial College London and Yale, USA.

Professor Siveter said: "Such a well-preserved fossil is exciting, and this particular one is a unique example of its kind in the fossil record, and so we can establish it as a new species of a new genus."

"Even though it is relatively small, at just nine millimetres long, it preserves incredible detail including body parts that are normally not fossilized. It provides scientists with important, novel insights into the evolution of the body plan, the limbs and possible respiratory-circulatory physiology of a primitive member of one of the major groups of Crustacea."

Credit: University Leicester

The fossil is named Cascolus ravitis in honour of Sir David, who grew up on University College Leicester campus (the forerunner of the University), in celebration of his 90th birthday. Cascolus is derived from castrum meaning 'stronghold' and colus, 'dwelling in', alluding to the Old English source for the surname Attenborough; while 'ravitis" is a combination of Ratae - the Roman name for Leicester - 'vita', life, and 'commeatis', a messenger.

Professor Siveter said: "In my youth, David Attenborough's early programmes on the BBC, such as 'Zoo Quest', greatly encouraged my interest in Natural History and it is a pleasure to honour him in this way."

Sir David Attenborough said: "The biggest compliment that a biologist or palaeontologist can pay to another one is to name a fossil in his honour and I take this as a very great compliment. I was once a scientist so I'm very honoured and flattered that the Professor should say such nice things about me now."

Professor Siveter added: "The animal lived in the Silurian period of geological time. Some 430 million years ago much of southern Britain was positioned in warm southerly subtropical latitudes, quite close to a large ancient continent of what we now call North America, and was covered by a shallow sea. The crustacean and other animals living there died and were preserved when a fine volcanic ash rained down upon them."

The fossil specimen has been reconstructed as a virtual fossil by 3D computer modeling.

Contacts and sources:
David Siveter 
University of Leicester

The research is published in the journal Proceedings of the Royal Society B,

Tarnish-Proof Transparent Silver Films for Flexible Displays, Touch Screens, Metamaterials

The thinnest, smoothest layer of silver that can survive air exposure has been laid down at the University of Michigan, and it could change the way touchscreens and flat or flexible displays are made.

It could also help improve computing power, affecting both the transfer of information within a silicon chip and the patterning of the chip itself through metamaterial superlenses.

By combining the silver with a little bit of aluminum, the University of Michigan (U-M researchers found that it was possible to produce exceptionally thin, smooth layers of silver that are resistant to tarnishing. They applied an anti-reflective coating to make one thin metal layer up to )92.4 percent transparent.

University of Michigan researchers have created a transparent silver film that could be used in touchscreens, flexible displays and other advanced applications. L. Jay Guo, professor of electrical engineering and computer science, holds up a piece of the material.
 Image credit: Joseph Xu/Michigan Engineering.

The team showed that the silver coating could guide light about 10 times as far as other metal waveguides—a property that could make it useful for faster computing. And they layered the silver films into a metamaterial hyperlens that could be used to create dense patterns with feature sizes a fraction of what is possible with ordinary ultraviolet methods, on silicon chips, for instance.

Screens of all stripes need transparent electrodes to control which pixels are lit up, but touchscreens are particularly dependent on them. A modern touch screen is made of a transparent conductive layer covered with a nonconductive layer. It senses electrical changes where a conductive object—such as a finger—is pressed against the screen.

"The transparent conductor market has been dominated to this day by one single material," said L. Jay Guo, professor of electrical engineering and computer science.

This material, indium tin oxide, is projected to become expensive as demand for touch screens continues to grow; there are relatively few known sources of indium, Guo said.

"Before, it was very cheap. Now, the price is rising sharply," he said.

The ultrathin film could make silver a worthy successor.

L. Jay Guo, professor of electrical engineering and computer science at the University of Michigan, and Chengang Ji, a doctoral student in the same department, discuss results from a test of a "stainless" silver film that their research group has created.  
Image credit: Joseph Xu/Michigan Engineering

Usually, it's impossible to make a continuous layer of silver less than 15 nanometers thick, or roughly 100 silver atoms. Silver has a tendency to cluster together in small islands rather than extend into an even coating, Guo said.

By adding about 6 percent aluminum, the researchers coaxed the metal into a film of less than half that thickness—seven nanometers. What's more, when they exposed it to air, it didn't immediately tarnish as pure silver films do. After several months, the film maintained its conductive properties and transparency. And it was firmly stuck on, whereas pure silver comes off glass with Scotch tape.

In addition to their potential to serve as transparent conductors for touch screens, the thin silver films offer two more tricks, both having to do with silver's unparalleled ability to transport visible and infrared light waves along its surface. The light waves shrink and travel as so-called surface plasmon polaritons, showing up as oscillations in the concentration of electrons on the silver's surface.

Those oscillations encode the frequency of the light, preserving it so that it can emerge on the other side. While optical fibers can't scale down to the size of copper wires on today's computer chips, plasmonic waveguides could allow information to travel in optical rather than electronic form for faster data transfer. As a waveguide, the smooth silver film could transport the surface plasmons over a centimeter—enough to get by inside a computer chip.

The plasmonic capability of the silver film can also be harnessed in metamaterials, which handle light in ways that break the usual rules of optics. Because the light travels with a much shorter wavelength as it moves along the metal surface, the film alone acts as a superlens. Or, to make out even smaller features, the thin silver layers can be alternated with a dielectric material, such as glass, to make a hyperlens.

Such lenses can image objects that are smaller than the wavelength of light, which would blur in an optical microscope. It can also enable laser patterning—such as is used to etch transistors into silicon chips today—to achieve smaller features.

The first author is Cheng Zhang, a recent U-M doctoral graduate in electrical engineering and computer science who now works as a postdoctoral researcher at National Institute of Standards and Technology.

A paper on this research, titled "High-performance Doped Silver Films: Overcoming Fundamental Material Limits for Nanophotonic Applications" is published in Advanced Materials. The study was supported by the National Science Foundation and the Beijing Institute of Collaborative Innovation. U-M has applied for a patent and is seeking partners to bring the technology to market.

Contacts and sources:
Katherine McAlpine
University of Michigan

Breaking the Supermassive Black Hole Speed Limit

A new computer simulation helps explain the existence of puzzling supermassive black holes observed in the early universe. The simulation is based on a computer code used to understand the coupling of radiation and certain materials.

"Supermassive black holes have a speed limit that governs how fast and how large they can grow," said Joseph Smidt of the Theoretical Design Division at Los Alamos National Laboratory, "The relatively recent discovery of supermassive black holes in the early development of the universe raised a fundamental question, how did they get so big so fast?"

Using computer codes developed at Los Alamos for modeling the interaction of matter and radiation related to the Lab's stockpile stewardship mission, Smidt and colleagues created a simulation of collapsing stars that resulted in supermassive black holes forming in less time than expected, cosmologically speaking, in the first billion years of the universe.

This is a quasar growing under intense accretion streams.

Credit: Los Alamos National Laboratory

"It turns out that while supermassive black holes have a growth speed limit, certain types of massive stars do not," said Smidt. "We asked, what if we could find a place where stars could grow much faster, perhaps to the size of many thousands of suns; could they form supermassive black holes in less time?"

It turns out the Los Alamos computer model not only confirms the possibility of speedy supermassive black hole formation, but also fits many other phenomena of black holes that are routinely observed by astrophysicists. The research shows that the simulated supermassive black holes are also interacting with galaxies in the same way that is observed in nature, including star formation rates, galaxy density profiles, and thermal and ionization rates in gasses.

"This was largely unexpected," said Smidt. "I thought this idea of growing a massive star in a special configuration and forming a black hole with the right kind of masses was something we could approximate, but to see the black hole inducing star formation and driving the dynamics in ways that we've observed in nature was really icing on the cake."

Gravitational collapse of the universe.
Credit: Los Alamos National Laboratory

A key mission area at Los Alamos National Laboratory is understanding how radiation interacts with certain materials. Because supermassive black holes produce huge quantities of hot radiation, their behavior helps test computer codes designed to model the coupling of radiation and matter. The codes are used, along with large- and small-scale experiments, to assure the safety, security, and effectiveness of the U.S. nuclear deterrent.

"We've gotten to a point at Los Alamos," said Smidt, "with the computer codes we're using, the physics understanding, and the supercomputing facilities, that we can do detailed calculations that replicate some of the forces driving the evolution of the Universe."

Contacts  and sources:
Kevin Roark
Los Alamos National Laboratory

Research paper available at https://arxiv.org/pdf/1703.00449.pdf

Mystery of How Sperm Swim Revealed in Mathematical Formula

Researchers have developed a mathematical formula based on the rhythmic movement of a sperm's head and tail, which significantly reduces the complexities of understanding and predicting how sperm make the difficult journey towards fertilising an egg.

Researchers at the Universities of York, Birmingham, Oxford and Kyoto University, Japan, found that the sperm's tail creates a characteristic rhythm that pushes the sperm forward, but also pulls the head backwards and sideways in a coordinated fashion.

Successful fertility relies on how a sperm moves through fluid, but capturing details of this movement is a complicated issue.

Sperm stirs the fluid around in a very coordinated way locomotion, not too dissimilar to the way in which magnetic fields are formed around magnets.
Credit: Kyoto University

The team aim to use these new findings to understand how larger groups of sperm behave and interact, a task that would be impossible using modern observational techniques. The work could provide new insights into treating male infertility.

Dr Hermes Gadêlha, from the University of York's Department of Mathematics, said: "In order to observe, at the microscale, how a sperm achieves forward propulsion through fluid, sophisticated microscopic high precision techniques are currently employed.

"Measurements of the beat of the sperm's tail are fed into a computer model, which then helps to understand the fluid flow patterns that result from this movement.

"Numerical simulations are used to identify the flow around the sperm, but as the structures of the fluid are so complex, the data is particularly challenging to understand and use. Around 55 million spermatozoa are found in a given sample, so it is understandably very difficult to model how they move simultaneously.

"We wanted to create a mathematical formula that would simplify how we address this problem and make it easier to predict how large numbers of sperm swim. This would help us understand why some sperm succeed and others fail."

By analysing the head and tail movements of the sperm, researchers have now shown that the sperm moves the fluid in a coordinated rhythmic way, which can be captured to form a relatively simple mathematical formula. This means complex and expensive computer simulations are no longer needed to understand how the fluid moves as the sperm swim.

The research demonstrated that the sperm has to make multiple contradictory movements, such as moving backwards, in order to propel it forward towards the egg.

The whip-like tail of the sperm has a particular rhythm that pulls the head backwards and sideways to create a jerky fluid flow, countering some of the intense friction that is created due to their diminutive sizes.

Dr Gadêlha said: "It is true when scientists say how miraculous it is that a sperm ever reaches an egg, but the human body has a very sophisticated system of making sure the right cells come together.

"You would assume that the jerky movements of the sperm would have a very random impact on the fluid flow around it, making it even more difficult for competing sperm cells to navigate through it, but in fact you see well defined patterns forming in the fluid around the sperm.

"This suggests that sperm stirs the fluid around in a very coordinated way to achieve locomotion, not too dissimilar to the way in which magnetic fields are formed around magnets. So although the fluid drag makes it very difficult for the sperm to make forward motion, it does coordinate with its rhythmic movements to ensure that only a few selected ones achieve forward propulsion."

Now that the team has a mathematical formula that can predict the fluid movement of one sperm, the next step is to use the model for predictions on larger numbers of cells. They also believe that it will have implications for new innovations in infertility treatment.

The research is published in the journal Physical Review Letters.

Contacts and sources:
Samantha Martin
University of York

Handheld X-Ray Sources May Soon Be a Reality

Electronic oscillations in graphene could make a tabletop—or even handheld— source of X-rays a reality.

Since their discovery in 1895, X-rays have led to significant advances in science, medicine and industry. From probing distant galaxies to screening at airport security and facilitating medical diagnosis, they have allowed us to look beyond the surface and see what lies beneath.

Now, a collaboration between the A*STAR Singapore Institute of Manufacturing Technology (SIMTech) and the Massachusetts Institute of Technology (MIT) in the US has proposed a versatile, directional X-ray source that could fit on a laboratory bench and is based on the intriguing two-dimensional material graphene.

A free electron ‘wiggled’ by graphene plasmons emits an X-ray pulse.
Copyright : A*STAR Singapore Institute of Manufacturing Technology.

X-rays are high-frequency electromagnetic waves that can be generated using X-ray tube technology or from huge sources like synchrotrons and kilometrelong free electron lasers.

But X-ray tube sources, popularly used in medical diagnostics, emit radiation in all directions, wasting a significant amount of the generated X-rays. They are also not ‘tunable’, meaning that a different X-ray source must be installed in a diagnostic device for each desired wavelength.

Kilometre-long free electron lasers, on the other hand, can produce intense, tunable X-rays by accelerating free electrons to extremely high energies and then causing them to ‘wiggle’ using magnets. But these enormous X-ray sources only exist in a few places in the world and are housed in very large, expensive facilities.

An X-ray source that is both small and powerful has been much sought after for some time.

To this end, the team of SIMTech-MIT researchers employed graphene, a oneatom-thick sheet of carbon atoms, which, among other things, can support plasmons: collections of electronic oscillations that can be used to confine and manipulate light on scales of around ten nanometres.

The team first developed a robust simulation tool that models the exact physics of electrons interacting with a plasmon field sustained on a graphene sheet deposited on a piece of 'dielectric’, or insulating, material. By performing numerical simulations, the team showed that this set-up induces a ‘wiggling’ motion in electrons fired through the graphene plasmons, causing the electrons to produce high-frequency X-ray radiation. The simulations agreed with the analytical theory developed by the team to explain how electrons and plasmons interact to produce X-rays.

One standout characteristic of such a source will be its ‘pointability’, which will increase efficiency and hence reduce costs by ensuring that all the generated radiation goes where it’s intended. This will make the source promising for medical treatments as it could be used to target tumours more precisely and hence minimize damage to surrounding organs and cells.

Perhaps most attractive will be the source’s versatility. The output radiation frequency can be tuned in real time from longer infrared rays to shorter X-rays by modifying various elements of the source, such as the speed of the electrons, the frequency of the graphene plasmons and the conductivity of the graphene.

This flexible, compact source is promising as a cost-effective alternative to the high-intensity beams used for fundamental scientific and biomedical research. “Although there is a long way to go to actual realization, this is a very exciting research direction,” says Liang Jie Wong from SIMTech. “Developing an intense X-ray source that can fit on a table or be held in one’s hand would potentially revolutionize many areas of science and technology.”

The team next plans to experimentally verify their concept with proof-of-principle trials.

Contacts and sources:
Dr Liang Jie Wong
Singapore Institute of Manufacturing Technology
Agency for Science, Technology and Research

New Twist on the Sofa Problem That Stumped Mathematicians and Furniture Movers

Most of us have struggled with the mathematical puzzle known as the "moving sofa problem." It poses a deceptively simple question: What is the largest sofa that can pivot around an L-shaped hallway corner?

A mover will tell you to just stand the sofa on end. But imagine the sofa is impossible to lift, squish or tilt. Although it still seems easy to solve, the moving sofa problem has stymied math sleuths for more than 50 years. That's because the challenge for mathematicians is both finding the largest sofa and proving it to be the largest. Without a proof, it's always possible someone will come along with a better solution.

"It's a surprisingly tough problem," said math professor Dan Romik, chair of the Department of Mathematics at UC Davis. "It's so simple you can explain it to a child in five minutes, but no one has found a proof yet.

The Moving Sofa problem asks, what is the largest shape that can move around a right-angled turn? UC Davis mathematician Dan Romik has extended this problem to a hallway with two turns, and shows that a 'bikini top' shaped sofa is the largest so far found that can move down such a hallway.

Romik’s Ambidextrous Sofa is the largest sofa to fit round two turns. It has a sofa constant of 1.64.
Credit; Dan Romik, UC Davis

The largest area that will fit around a corner is called the "sofa constant" (yes, really). It is measured in units where one unit corresponds to the width of the hallway.

Inspired by his passion for 3-D printing, Romik recently tackled a twist on the sofa problem called the ambidextrous moving sofa. In this scenario, the sofa must maneuver around both left and right 90-degree turns. His findings are published online and will appear in the journal Experimental Mathematics.

Eureka Moment

Romik, who specializes in combinatorics, enjoys pondering tough questions about shapes and structures. But it was a hobby that sparked Romik's interest in the moving sofa problem--he wanted to 3-D print a sofa and hallway. "I'm excited by how 3-D technology can be used in math," said Romik, who has a 3-D printer at home. "Having something you can move around with your hands can really help your intuition."

The Gerver sofa is the largest found that will fit round a single turn. It has a “sofa constant” of 2.22 units, where one unit represents the width of the hallway.

Credit: Dan Romik/UC Davis

The Gerver sofa--which resembles an old telephone handset--is the biggest sofa found to date for a one-turn hallway. As Romik tinkered with translating Gerver's equations into something a 3-D printer can understand, he became engrossed in the mathematics underlying Gerver's solution. Romik ended up devoting several months to developing new equations and writing computer code that refined and extended Gerver's ideas. "All this time I did not think I was doing research. I was just playing around," he said. "Then, in January 2016, I had to put this aside for a few months. When I went back to the program in April, I had a lightbulb flash. Maybe the methods I used for the Gerver sofa could be used for something else."

Romik decided to tackle the problem of a hallway with two turns. When tasked with fitting a sofa through the hallway corners, Romik's software spit out a shape resembling a bikini top, with symmetrical curves joined by a narrow center. "I remember sitting in a café when I saw this new shape for the first time," Romik said. "It was such a beautiful moment."

Finding Symmetry

Like the Gerver sofa, Romik's ambidextrous sofa is still only a best guess. But Romik's findings show the question can still lead to new mathematical insights. "Although the moving sofa problem may appear abstract, the solution involves new mathematical techniques that can pave the way to more complex ideas," Romik said. "There's still lots to discover in math."

Contacts and sources:
Andy Fell
University of California Davis

New Non-Toxic Material Generates Electricity Through Hot and Cold, Could Charge Electronics

Thanks to the discovery of a new material by University of Utah engineers, jewelry such as a ring and your body heat could generate enough electricity to power a body sensor, or a cooking pan could charge a cellphone in just a few hours.

The team, led by University of Utah materials science and engineering professor Ashutosh Tiwari, has found that a combination of the chemical elements calcium, cobalt and terbium can create an efficient, inexpensive and bio-friendly material that can generate electricity through a thermoelectric process involving heat and cold air.

Thermoelectric effect is a process where the temperature difference in a material generates an electrical voltage. When one end of the material is hot and the other end is cold, charge carriers from the hot end move through the material to the cold end, generating an electrical voltage. The material needs less than a one-degree difference in temperature to produce a detectable voltage.

University of Utah materials science and engineering professor Ashutosh Tiwari and has team have an inexpensive and bio-friendly material that can generate electricity through a thermoelectric process involving heat and cold air. In this graphic, the heat from a hot stove, coupled with the cooler water or food in a cooking pot, could generate enough electricity to charge a cellphone.

Credit: Ashutosh Tiwari

Their findings were published in a new paper March 20 in the latest issue of Scientific Reports. The first author on the paper is University of Utah materials science and engineering postdoctoral researcher, Shrikant Saini.

For years, researchers have been looking for the right kind of material that makes the process more efficient and produces more electricity yet is not toxic. There are other materials that can generate power this way, such as cadmium-, telluride- or mercury-based materials, but those are toxic to humans. The unique advantage to this new material by Tiwari’s team is that it is inexpensive to produce and, mostly importantly, bio-friendly and eco-friendly while still being efficient at generating electricity, Tiwari says. Therefore, it could be safe to use with humans.

“There are no toxic chemicals involved,” he says. “It’s very efficient and can be used for a lot of day-to-day applications.”

The applications for this new material are endless, Tiwari says. It could be built into jewelry that uses body heat to power implantable medical devices such as blood-glucose monitors or heart monitors. It could be used to charge mobile devices through cooking pans, or in cars where it draws from the heat of the engine. Airplanes could generate extra power by using heat from within the cabin versus the cold air outside. Power plants also could use the material to produce more electricity from the escaped heat the plant generates.

University of Utah materials science and engineering professor Ashutosh Tiwari and his team have an inexpensive and bio-friendly material that can generate electricity through a thermoelectric process involving heat and cold air. The material (the black blocks between the two plates pictured) could be used with cooking pots to charge phones or jewelry to power health sensors.

Credit: Dan Hixson/University of Utah College of Engineering

“In power plants, about 60 percent of energy is wasted,” postdoctoral researcher, Saini, says. “With this, you could reuse some of that 60 percent.”

Finally, Tiwari says it could be used in developing countries where electricity is scarce and the only source of energy is the fire in stoves.

The Technology & Venture Commercialization Office of the University of Utah has filed a U.S. patent for the material, and the team will initially develop it for use in cars and for biosensors, Tiwari says.

In addition to Tiwari and Saini, co-authors on the paper include graduate students Haritha Sree Yaddanapudi, Kun Tian, Yinong Yin and David Magginetti.

Contacts and sources:
 University of Utah

Is Spring Getting Longer? Research Points to a Lengthening “Vernal Window”

With the first day of spring around the corner, temperatures are beginning to rise, ice is melting, and the world around us is starting to blossom. Scientists sometimes refer to this transition from winter to the growing season as the “vernal window,” and a new study led by the University of New Hampshire shows this window may be opening earlier and possibly for longer.

“Historically, the transition into spring is comparatively shorter than other seasons,” said Alexandra Contosta, a research assistant professor at the University of New Hampshire’s Earth Systems Research Center. “You have snow melting and lots of water moving through aquatic systems, nutrients flushing through that water, soils warming up, and buds breaking on trees. Something striking happens after a very cold winter or when there’s been a lot of snow. Things seem to wake up all together, which is why spring seems to happen so quickly and can feel so dramatic.”

Early tree blooms in spring

Credit: NHEPSCoR

However, research shows that the Northern Hemisphere snow cover extent has declined significantly in the past 30 years. To see if this may be influencing the so-called vernal window, or the transition from winter into spring, Contosta led a team of scientists that collected data from a network of New Hampshire EPSCoR soil and water sensors installed across the state. They monitored snow levels and the forest canopy for three years. Their information was supplemented with climate and satellite data along with precipitation and stream data collected by more than 100 volunteers across the state. 

They not only looked at dates when certain events occurred that marked the seasonal transition, such as the melting of snow and the emergence of leaves in trees, but also the time period between these events. Their findings, published early online in the journal Global Change Biology, showed that warmer winters with less snow resulted in a longer lag time between spring events and a more protracted vernal window.

This type of changing timetable for spring may have potential ecological, social, and economic consequences that Contosta and her team are currently investigating. Agriculture, fisheries, and even outdoor recreation activities can be highly dependent on the timing of springtime climate conditions. A longer spring could mean a longer mud season requiring more road repairs and truck weight restrictions, a possible shift in the duration of the sugar maple season, or earlier lake thaw which might have implications with migratory birds. The ice melts earlier, but the birds may not have returned yet, causing a delay, or lengthening, in springtime ecological events.

The researchers plan to test their conclusions with data from a larger geographic area and over longer periods.

New Hampshire EPSCoR’s Ecosystems & Society project team and co-authors include Alden Adolph and Mary Albert, Dartmouth College; Denise Burchsted, Keene State College; Mark Green, Plymouth State University; David Guerra, St. Anselm College; Elizabeth Burakowski, Jack Dibb, Mary Martin, William H. McDowell, Michael Routhier, Cameron Wake, Wilfred Wollheim, University of New Hampshire; and Rachel Whitaker, White Mountains Community College.

This research was supported by award EPS-1101245 from the National Science Foundation.
The University of New Hampshire is a flagship research university that inspires innovation and transforms lives in our state, nation and world. More than 16,000 students from all 50 states and 71 countries engage with an award-winning faculty in top ranked programs in business, engineering, law, liberal arts and the sciences across more than 200 programs of study. UNH’s research portfolio includes partnerships with NASA, NOAA, NSF and NIH, receiving more than $100 million in competitive external funding every year to further explore and define the frontiers of land, sea and space.

Contacts and sources:
University of New Hampshire

Research Leads to a Golden Discovery for Wearable Technology

Some day, your smartphone might completely conform to your wrist, and when it does, it might be covered in pure gold, thanks to researchers at Missouri University of Science and Technology.

Writing in the March 17 issue of the journal Science, the Missouri S&T researchers say they have developed a way to “grow” thin layers of gold on single crystal wafers of silicon, remove the gold foils, and use them as substrates on which to grow other electronic materials.

The research team’s discovery could revolutionize wearable or “flexible” technology research, greatly improving the versatility of such electronics in the future.

An example of a gold foil peeled from single crystal silicon.
Credit: Reprinted with permission from Naveen Mahenderkar et al., Science [355]:[1203] (2017)

According to lead researcher Dr. Jay A. Switzer, the majority of research into wearable technology has been done using polymer substrates, or substrates made up of multiple crystals. “And then they put some typically organic semiconductor on there that ends up being flexible, but you lose the order that (silicon) has,” says Switzer, Donald L. Castleman/FCR Endowed Professor of Discovery in Chemistry at S&T.

Because the polymer substrates are made up of multiple crystals, they have what are called grain boundaries, says Switzer. These grain boundaries can greatly limit the performance of an electronic device.

“Say you’re making a solar cell or an LED,” he says. “In a semiconductor, you have electrons and you have holes, which are the opposite of electrons. They can combine at grain boundaries and give off heat. And then you end up losing the light that you get out of an LED, or the current or voltage that you might get out of a solar cell.”

Most electronics on the market are made of silicon because it’s “relatively cheap, but also highly ordered,” Switzer says.

“99.99 percent of electronics are made out of silicon, and there’s a reason – it works great,” he says. “It’s a single crystal, and the atoms are perfectly aligned. But, when you have a single crystal like that, typically, it’s not flexible.”

By starting with single crystal silicon and growing gold foils on it, Switzer is able to keep the high order of silicon on the foil. But because the foil is gold, it’s also highly durable and flexible.

“We bent it 4,000 times, and basically the resistance didn’t change,” he says.

The gold foils are also essentially transparent because they are so thin. According to Switzer, his team has peeled foils as thin as seven nanometers.

Switzer says the challenge his research team faced was not in growing gold on the single crystal silicon, but getting it to peel off as such a thin layer of foil. Gold typically bonds very well to silicon.

“So we came up with this trick where we could photo-electrochemically oxidize the silicon,” Switzer says. “And the gold just slides off.”

Photoelectrochemical oxidation is the process by which light enables a semiconductor material, in this case silicon, to promote a catalytic oxidation reaction.

Switzer says thousands of gold foils—or foils of any number of other metals—can be made from a single crystal wafer of silicon.

The research team’s discovery can be considered a “happy accident.” Switzer says they were looking for a cheap way to make single crystals when they discovered this process.

“This is something that I think a lot of people who are interested in working with highly ordered materials like single crystals would appreciate making really easily,” he says. “Besides making flexible devices, it’s just going to open up a field for anybody who wants to work with single crystals.”

The research team included Naveen Kumar Mahenderkar, a Ph.D. candidate in materials science and engineering; Qingzhi Chen and Ying Chau Liu, both Ph.D. candidates in chemistry; Alexander Duchild, an undergraduate chemistry student; Seth Hofheins, a student at Rolla High School; and Dr. Eric Chason, professor of engineering at Brown University.

Contacts and sources: 
Missouri University of Science and Technology

Citation:Epitaxial lift-off of electrodeposited single-crystal gold foils for flexible electronics http://science.sciencemag.org/content/355/6330/1203

Tuesday, March 21, 2017

The New 'Living' Antibiotic Is Predatory Bacteria:

Antibiotic resistance is one of medicine’s most pressing problems. Now, a team from Korea is tackling this in a unique way: using bacteria to fight bacteria.

Before the discovery of penicillin in 1928, millions of lives were lost to relatively simple microbial infections. Since then, antibiotics have transformed modern medicine. The World Health Organization estimates that, on average, antibiotics add 20 years to each person’s life. However, the overuse of antibiotics has put pressure on bacteria to evolve resistance against these drugs, leading to the emergence of untreatable superbugs.

Now, researchers at South Korea’s Ulsan National Institute of Science and Technology (UNIST) aim to fight fire with fire by launching predatory bacteria capable of attacking other bacteria without harming human cells. “Bacteria eating bacteria. How cool is that?” asks Professor Robert Mitchell, the team leader. He and his colleagues are also developing a natural compound called violacein to tackle Staphylococcus, a group of around 30 different bacteria known to cause skin infections, pneumonia and blood poisoning. Some Staphylococcus bacteria such as MRSA (methicillin-resistant Staphylococcus aureus) are resistant to antibiotics, making infections harder to treat.

Methicillin-resistant Staphylococcus aureus (MRSA) bacteria.

Copyright : royaltystockphoto / 123rf

Violacein is a so-called ‘bisindole’: a metabolite produced by bacteria from the condensation of two molecules of tryptophan (an essential amino acid used in many organisms to ensure normal functioning and avoid illness and death). This compound is vibrant purple in colour and of interest to researchers for its anticancer, antifungal and antiviral properties. Researchers have discovered that it can stop bacteria from reproducing, and even kill the multidrug resistant bacterium Staphylococcus aureus, when used in the right doses. It also works well in conjunction with other existing antibiotics.

Mitchell and his team isolated a bacterial strain, called D. violaceinigra strain. NI28, from forest soil collected near Ulsan in South Korea. Using a technique called high performance liquid chromatography to separate and quantify compounds produced by the bacteria, they showed that strain N128 is capable of producing large quantities of crude violacein. They are now collaborating with fabric manufacturer Yeejoo Co., the Korea Institute of Ceramic Engineering and Technology, and research teams in Turkey and Romania to manufacture antibacterial fabrics infused with violacein that can effectively kill S. aureus.

A predatory bacterium attached to its prey.
Copyright : UNIST AEMLab

The team is also working on the predatory bacterium Bdellovibrio bacteriovorus. This is an obligate predator of bacteria, normally found in river water or soil. It attacks and enters the bacteria it must predate on to survive, growing and dividing repeatedly. Once inside, it eats the host from the inside out. When it has had its fill, it ruptures the host bacterium’s cell membrane and exits, ready to attack the next bacterium. Previous research showed that B. bacteriovorus does not harm human cells and can attack over 100 different bacterial pathogens.

The researchers examined how the predatory ability of B. bacteriovorus was affected by indole, a well-known metabolite produced by E. coli and many other bacteria. Indole regulates various biological functions in bacteria, for example regulating the stability of small DNA molecules, as well as functioning as a signalling molecule, which different communities of bacteria use to ‘talk’ and coordinate gene expression within a population. 

The researchers tested the predatory ability of B. bacteriovorus by setting up a bacterial version of a gladiator contest in flasks. They put various bacteria face to face with B. bacteriovorus and then artificially added different concentrations of indole and examined how this affected B. bacteriovorus’ predatory behaviour. They found that B. bacteriovorus takes much longer to attack E. coli—a common bacterial strain that can cause food poisoning, infections and fever—in the presence of indole. To make sure the predator-prey relationship was not influenced by E. coli’s own production of indole, they also tested the predatory ability of B. bacteriovorus on another food poison-causing bacterium called Salmonella, which does not produce indole. The result was the same: in high concentrations, indole even blocks and prevents the predatory bacteria from attacking altogether.

Professor Mitchell hopes this research is a step in the direction of understanding how B. bacteriovorus can be used and controlled to attack specific bacteria that cause illness, while avoiding ‘good’ bacteria necessary for daily survival. This could help in further development of ‘living antibiotics’.

Contacts and sources:
Professor Robert J. Mitchell
Ulsan National Institute of Science and Technology

Researchers Make DNA Detection Portable, Affordable Using Cellphones

Researchers at UCLA have developed an improved method to detect the presence of DNA biomarkers of disease that is compatible with use outside of a hospital or lab setting. The new technique leverages the sensors and optics of cellphones to read light produced by a new detector dye mixture that reports the presence of DNA molecules with a signal that is more than 10-times brighter.

Nucleic acids, such as DNA or RNA, are used in tests for infectious diseases, genetic disorders, cancer mutations that can be targeted by specific drugs, and fetal abnormality tests. The samples used in standard diagnostic tests typically contain only tiny amounts of a disease’s related nucleic acids. To assist optical detection, clinicians amplify the number of nucleic acids making them easier to find with the fluorescent dyes. 

Both the amplification and the optical detection steps have in the past required costly and bulky equipment, largely limiting their use to laboratories.

The combined dye/cellphone reader system achieved comparable results to equipment costing tens of thousands of dollars more.

Dino Di Carlo/UCLA

In a study published online in the journal ACS Nano, researchers from three UCLA entities — the Henry Samueli School of Engineering and Applied Science, the California NanoSystems Institute, and the David Geffen School of Medicine — showed how to take detection out of the lab and for a fraction of the cost.

The collaborative team of researchers included lead author Janay Kong, a UCLA Ph.D. student in bioengineering; Qingshan Wei, a post-doctoral researcher in electrical engineering; Aydogan Ozcan, Chancellor’s Professor of Electrical Engineering and Bioengineering; Dino Di Carlo, professor of bioengineering and mechanical and aerospace engineering; and Omai Garner, assistant professor of pathology and medicine at the David Geffen School of Medicine at UCLA.

The UCLA researchers focused on the challenges with low-cost optical detection. Small changes in light emitted from molecules that associate with DNA, called intercalator dyes, are used to identify DNA amplification, but these dyes are unstable and their changes are too dim for standard cellphone camera sensors.

But the team discovered an additive that stabilized the intercalator dyes and generated a large increase in fluorescent signal above the background light level, enabling the test to be integrated with inexpensive cellphone based detection methods. The combined novel dye/cellphone reader system achieved comparable results to equipment costing tens of thousands of dollars more.

To adapt a cellphone to detect the light produced from dyes associated with amplified DNA while those samples are in standard laboratory containers, such as well plates, the team developed a cost-effective, field-portable fiber optic bundle. The fibers in the bundle routed the signal from each well in the plate to a unique location of the camera sensor area. This handheld reader is able to provide comparable results to standard benchtop readers, but at a fraction of the cost, which the authors suggest is a promising sign that the reader could be applied to other fluorescence-based diagnostic tests.

“Currently nucleic acid amplification tests have issues generating a stable and high signal, which often necessitates the use of calibration dyes and samples which can be limiting for point-of-care use,” Di Carlo said. “The unique dye combination overcomes these issues and is able to generate a thermally stable signal, with a much higher signal to noise ratio. The DNA amplification curves we see look beautiful — without any of the normalization and calibration, which is usually performed, to get to the point that we start at.”

Additionally, the authors emphasized that the dye combinations discovered should be able to be used universally to detect any nucleic acid amplification, allowing for their use in a multitude of other amplification approaches and tests.

The team demonstrated the approach using a process called loop-mediated isothermal amplification, or LAMP, with DNA from lambda phage as the target molecule, as a proof of concept, and now plan to adapt the assay to complex clinical samples and nucleic acids associated with pathogens such as influenza.

The newest demonstration is part of a suite of technologies aimed at democratizing disease diagnosis developed by the UCLA team. Including low-cost optical readout and diagnostics based on consumer-electronic devices, microfluidic-based automation and molecular assays leveraging DNA nanotechnology.

This interdisciplinary work was supported through a team science grant from the National Science Foundation Emerging Frontiers in Research and Innovation program.

Contacts and sources:
Mathew Chin

Less Radiation in Inner Van Allen Belt Than Previously Believed

The inner Van Allen belt has less radiation than previously believed, according to a recent study in the Journal of Geophysical Research. Observations from NASA’s Van Allen probes show the fastest, most energetic electrons in the inner radiation belt are actually much rarer and harder to find than scientists expected. This is good news for spacecraft that are orbiting in the region and can be damaged by high levels of radiation. The results will also help scientists better understand—and detect—effects from high-altitude nuclear explosions.

“Basically what we’re doing is detecting very small signals against very large backgrounds,” said Geoff Reeves, a space physicist at Los Alamos National Laboratory and co-author of the study. “Let’s say you have a few snowflakes in a rainstorm—but you’ve never seen snowflakes before. How do you ignore the rain so you can just see the snowflakes? That’s what we’ve done here: we ignored a whole lot of protons so we could see the electrons—and it turns out there aren’t as many as we thought.”

Van Allen Probes circle radiation belts. This artist’s rendering of the Van Allen Probes mission shows the path of its two spacecraft through the radiation belts that surround Earth, which are made visible in false color.
Credit:  NASA

The Van Allen belts are two doughnut-shaped regions of charged particles encircling Earth (video). Past space missions have not been able to distinguish electrons from high-energy protons in the inner radiation belt. But by using a special instrument, the Magnetic Electron and Ion Spectrometer (MagEIS), on the Van Allen Probes, scientists could look at the particles separately for the first time. What they found was surprising: almost none of these super-fast electrons, known as relativistic electrons, are present in the inner belt.

Los Alamos National Laboratory has interest in the applications for space weather forecasting to protect satellites and also for monitoring the Nuclear Test Ban Treaty, which prohibits nuclear explosions in space. “A high-altitude nuclear explosion results in the creation of an artificial radiation belt,” said Reeves. “We can learn about the physics of an explosion by looking at these hard-to-detect relativistic electrons. If an artificial radiation belt were ever detected, these new observations would help us understand it better.”

Of the two radiation belts, scientists have long understood the outer belt to be the more active one. During intense geomagnetic storms, when charged particles from the sun hurtle across the solar system, the outer radiation belt pulsates dramatically, growing and shrinking in response to the pressure of the solar particles and magnetic field. Scientists thought that the inner belt maintains a steady position above Earth’s surface. The new results, however, show that’s not always true. For example, during a very strong geomagnetic storm in June 2015, relativistic electrons were pushed deep into the inner belt.

“When we carefully process the data and remove the contamination, we can see things that we’ve never been able to see before,” said Seth Claudepierre, lead author and Van Allen Probes scientist at the Aerospace Corporation in El Segundo, Calif. “These results are totally changing the way we think about the radiation belt at these energies.”

Given the rarity of the storms that can inject relativistic electrons into the inner belts, the scientists now understand that lower levels of radiation are typical there, a result that has implications for spacecraft flying in the region. Knowing exactly how much and what type of radiation is present in any given region of space may enable scientists and engineers to design lighter and cheaper satellites tailored to withstand the specific radiation levels they’ll encounter.
In addition to providing a new outlook on spacecraft design, the findings open a new realm for scientists to study next.

“This opens up the possibility of doing science that previously was not possible,” said Shri Kanekal, Van Allen Probes deputy mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and not involved with the study. “For example, we can now investigate under what circumstances these electrons penetrate the inner region and see if more intense geomagnetic storms give electrons that are more intense or more energetic.”

The Van Allen Probes is the second mission in NASA’s Living with a Star Program and one of many NASA heliophysics missions studying our near-Earth environment. The spacecraft plunge through the radiation belts five to six times a day on a highly elliptical orbit to understand the physical processes that add and remove electrons from the region. The Johns Hopkins Applied Physics Laboratory in Laurel, Md., built and operates the Van Allen Probes for NASA’s Science Mission Directorate.

About the Van Allen Probes (www.nasa.gov/van-allen-probes)

The Van Allen Probes is a NASA mission that studies two extreme and dynamic regions of space known as the Van Allen Radiation Belts that surround Earth. Named for their discoverer, James Van Allen, these two concentric, donut-shaped rings are filled with high-energy particles that gyrate, bounce, and drift through the region, sometimes shooting down to Earth’s atmosphere, sometimes escaping out into space. The radiation belts swell and shrink over time as part of a much larger space weather system driven by energy and material that erupt off the sun’s surface and fill the entire solar system.

Launched on August 30, 2012, the two Van Allen Probes spacecraft operate in the harsh conditions they are studying. While other satellites have the luxury of turning off or protecting themselves in the middle of intense space weather, the Van Allen Probes must continue to collect data and, therefore, have been built to withstand the constant bombardment of particles and radiation they will experience in this intense area of space.

Contacts and sources:
Los Alamos National Laboratory (www.lanl.gov)

Children Who Play Outside More Likely to Protect Nature as Adults

Protecting the environment can be as easy as telling your kids to go outdoors and play, according to a new UBC study.

Research by Catherine Broom, assist. prof. in the Faculty of Education at UBC Okanagan, shows that 87 per cent of study respondents who played outside as children expressed a continued love of nature as young adults. Of that group, 84 per cent said taking care of the environment was a priority.

“Developing positive experiences in nature at a young age can influence our attitudes and behaviours towards nature as adults,” says Broom. “It is important to study these childhood experiences in order to develop environmental awareness and action in the next generation.”
Credit; Pixabay

The study interviewed 50 university students between the ages of 18 to 25. Of the group, 100 per cent of females stated that they loved or somewhat loved nature and 87 per cent of males responded the same.

While further research is needed, Broom believes that environmental awareness programs like Girl Guides, Boy Scouts, or the Duke of Edinburgh awards may help develop children’s environmental awareness and action, aligning with environmental priorities such as Canada’s goal to cut emissions by 2030.

According to a 2016 report from the Conference Board of Canada, the province’s emissions of greenhouses gasses are on track to increase through 2030, with a current ranking of 14 among 16 peer countries when it comes to environmental performance, only beating the United States and Australia.

“Our findings imply that providing positive childhood experiences in nature, such as outdoor school programs, may help to develop care for the environment in adults,” Broom says. “However, these may not be sufficient unless programs are building knowledge and self-awareness of environmental stewardship.”

Broom believes that schools and early childhood classroom activities should connect positive experiences in nature with mindful learning and reflection that help empower students to take a personal role in protecting the environment by recycling, turning off the lights, and using alternative transportation methods.

“Students need to learn and have a conscious understanding that the decisions we make each day can influence our environment, such as where we buy our food and how we use the Earth’s natural resources.”

Broom’s study was recently published in the Australian Journal of Environmental Education.

Contacts and sources:
Patty Wellborn
University Of British Columbia

Fish Evolve by Playing it Safe

New research supports the creation of more marine reserves in the world's oceans because, the authors say, fish can evolve to be more cautious and stay away from fishing nets.

The research suggests that by creating additional "no-take" areas, some fish will stay within marine reserves where they are protected from fishing. While other fish will move around the ocean, these less mobile fish will continue to live in the protected areas, pass this behaviour on to their offspring, and contribute to future generations to increase the overall stock.

"Even for fish like tuna and sharks that spend a lot of time far from shore, marine reserves are an important conservation tool," said Jonathan Mee, lead author of the study and a faculty member at Mount Royal University who conducted this research while completing a postdoctoral fellowship at UBC. "We used mathematical modelling to find out under what conditions marine reserves might push fish to evolve to escape capture."

Credit: Terry Goss / Wikimedia Commons

In a collaboration between UBC's Biodiversity Research Centre and the Sea Around Us project at the Institute for the Oceans and Fisheries, researchers modeled the movements of skipjack and bluefin tuna and great white sharks in the ocean.

They found evidence that within 10 years of creating new marine reserves, the movement pattern of tuna could change while it would take up to five decades for the longer-living great white shark to change. They also found evidence that the greater the fishing pressure close to the reserves, the faster the fish would evolve to stay in the protected space.

The researchers argue there is a need to create more marine reserves because fishing operations have grown exponentially in recent decades, leading to a global catch decline of 1.2 million tonnes of fish per year.

"The boats got bigger and now we can cover the entire range of the tuna. The distance doesn't protect them, depth doesn't protect them, nothing protects them except our decision to remove ourselves from certain areas in the form of marine reserves," said Daniel Pauly, principal investigator of the Sea Around Us project and a co-author of the study. "A well-controlled marine reserve would, at least in part, protect against the effect of overfishing outside the reserve."

These findings show fisheries managers, conservation planners, environmentalists and professionals in the fishing industry the effectiveness of marine reserves.

"The reserves are likely more effective than previously thought in preventing extinction for some species, protecting biodiversity and even acting as an insurance policy," said Sarah Otto of UBC's Biodiversity Research Centre.

Contacts and sources:
Valentina Ruiz Leotaud
University Of British Columbia

The study was published last week in Evolutionary Applications: http://onlinelibrary.wiley.com/doi/10.1111/eva.12460/full

Mars May One Day Have Rings Like Saturn

As children, we learned about our solar system's planets by certain characteristics -- Jupiter is the largest, Saturn has rings, Mercury is closest to the sun. Mars is red, but it's possible that one of our closest neighbors also had rings at one point and may have them again someday.

That's the theory put forth by Purdue University scientists, whose findings were published in the journal Nature Geoscience. David Minton, assistant professor of Earth, atmospheric and planetary sciences, and Andrew Hesselbrock, a doctoral student in physics and astronomy, developed a model that suggests that debris that was pushed into space from an asteroid or other body slamming into Mars around 4.3 billion years ago and alternates between becoming a planetary ring and clumping up to form a moon.

A theory exists that Mars' large North Polar Basin or Borealis Basin, which covers about 40 percent of the planet in its northern hemisphere, was created by that impact, sending debris into space.

Phobos, a Martian moon, might eventually disintegrate and form a ring around the red planet, according to a new theory by Purdue University scientists. The NASA-funded research indicates that this process of moons breaking apart into rings and then reforming as moons may have happened several times over billions of years.

Image by Purdue University Envision Center

"That large impact would have blasted enough material off the surface of Mars to form a ring," Hesselbrock said. Hesselbrock and Minton's model suggests that as the ring formed and the debris slowly moved away from the planet and spread out, it began to clump and eventually formed a moon. Over time, Mars' gravitational pull would have pulled that moon toward the planet until it reached the Roche limit, the distance within which the planet's tidal forces will break apart a celestial body that is held together only by gravity.

Phobos, one of Mars' moons, is getting closer to the planet. According to the model, Phobos will break apart upon reaching the Roche limit and become a set of rings in roughly 70 million years. Depending on where the Roche limit is, Minton and Hesselbrock believe this cycle may have repeated between three and seven times over billions of years. Each time a moon broke apart and reformed from the resulting ring, its successor moon would be five times smaller than the last, according to the model, and debris would have rained down on the planet, possibly explaining enigmatic sedimentary deposits found near Mars' equator.

A new theory by Purdue University scientists says that the Martian moon Phobos might eventually break apart, forming a ring around the red planet. The NASA-funded scientists theorize that this ring formation has happened before, and that as the moons break apart some of the material falls to the surface, as shown in this illustration.

Illustration by Purdue University Envision Center

"You could have had kilometer-thick piles of moon sediment raining down on Mars in the early parts of the planet's history, and there are enigmatic sedimentary deposits on Mars with no explanation as to how they got there," Minton said. "And now it's possible to study that material."

Other theories suggest that the impact with Mars that created the North Polar Basin led to the formation of Phobos 4.3 billion years ago, but Minton said it's unlikely the moon could have lasted all that time. Also, Phobos would have had to form far from Mars and would have had to cross through the resonance of Deimos, the outer of Mars' two moons. Resonance occurs when two moons exert gravitational influence on each other in a repeated periodic basis, as major moons of Jupiter do. By passing through its resonance, Phobos would have altered Deimos' orbit. But Deimos' orbit is within one degree of Mars' equator, suggesting it has had no effect on Phobos.

"Not much has happened to Deimos' orbit since it formed," Minton said. "Phobos passing through these resonances would have changed that."

Richard Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California, is the project scientist for NASA's Mars Reconnaissance Orbiter, whose gravity mapping provided support for the hypothesis that the northern lowlands were formed by a massive impact.

"This research highlights even more ways that major impacts can affect a planetary body," he said.

Minton and Hesselbrock will now focus their work on either the dynamics of the first set of rings that formed or the materials that have rained down on Mars from disintegration of moons.

Contacts and sources:
Steve Tally
Purdue University

How Fullerite Becomes Harder Than Diamond, So Hard It Scratches Diamond

Physicists have simulated the structure of a new material based on fullerite and single crystal diamond to show how this material can obtain ultrahigh hardness. This discovery allows the estimations the potential conditions for obtaining ultrahard materials. The results were published in the Carbon journal.

Fullerite generally is a molecular crystal with fullerene molecules at its lattice nodes. Fullerenes are a form of molecular carbon where carbon atoms form a sphere. It was first synthesized over thirty years ago, and its discovery was awarded with the Nobel Prize. Carbon spheres in fullerite may be packed in different ways, and the hardness of the material strongly depends on how the fullerenes are connected to each other. 

A group of scientists from the Moscow Institute of Physics and Technology (MIPT), the Skolkovo Institute of Science and Technology (Skoltech), the National University of Science and Technology (MISIS) and the Federal State Budgetary Scientific Institution Technological Institute for Superhard and Novel Carbon Materials (FSBSI TISNCM, Moscow, Troitsk) headed by Prof. Leonid Chernozatonskii from the Institute of Biochemical Physics (IBCP) of the Russian Academy of Sciences managed to explain why fullerite becomes an ultra-hard material.

Model of fullerite inside diamond.

Figure provided by A. Kvashnin

Alexander Kvashnin, Candidate of Physics and Mathematics, the main author, remarked, "When we started to discuss this idea, I was working at TISNCM. There, in 1998, a group of scientists headed by Vladimir D. Blank obtained a new material based on fullerenes — ultrahard fullerite, or «tisnumit». According to the measurements, this new material could scratch diamond, that is, it was in fact harder than diamond."

Fig.: (left) molecule of fullerene, (middle) fullerite, (right) polymerized fullerite (SH-phase)

Credit: Moscow Institute of Physics and Technology

The obtained substance was not single crystal material; it contained amorphous carbon and 3D-polymerized molecules of С60. Still, its crystal structure is not completely determined. The fullerene molecule has excellent mechanical rigidity. At the same time, the fullerite crystal is quite a soft material under normal conditions, but becomes harder than diamond under pressure (due to the 3D polymerization). Although this material has been synthesized and studied for more than 20 years now, the reason why it becomes ultrahard is still unknown. There is a number of models that have been developed to explain how fullerenes can be polymerized into fullerite.

One of the models was proposed by Prof. Leonid A. Chernozatonskii. The X-ray diffraction pattern of the model perfectly agrees with experimental data and should have high volumetric bulk modulus, several times higher than the diamond value. But the relaxed structure of the model does not display such fascinating properties.

Alexander Kvashnin remarks, "We based our analysis on that model and the experimentally known fact that if you apply high pressure, more than 10 GPa to fullerene powder, and heat it above 1800 К, you obtain a polycrystalline diamond. The idea was to combine these two facts. On the one hand, a super-hard fullerite material, and on the other hand, under pressure, fullerenes turn into a polycrystalline diamond."

The scientists suggested that under pressure, part of the fullerite turned into diamond, while the other part remained as fullerite, but in a compressed state within the diamond. To simplify the model, the fullerite crystal structure proposed by Prof. Chernozatonskii was taken and placed inside a single crystal diamond. Then this composite material was studied. The idea was that fullerite inside diamond should be compressed. It is known that in the compressed state, the elastic and mechanical properties of the material would increase. And diamond would act as a shell, which keeps the compressed fullerite inside to preserve all those properties. 

In the study, they first analysed small models containing 2.5 nm fullerite grain inside the 1 nm thick diamond shell. However, such a small model did not comply with the experimental data. Then the researchers started modelling the composites, where the size of fullerite was increased up to 15.8 nm, and the thickness of diamond shell remained the same. The changes in the X-ray diffraction spectrum showed that the increase in the fullerite size brought the spectrum closer to the experimental data. 

After comparing the spectra, it was assumed that most likely in the experiment, they had obtained an amorphous carbon medium with a hydrostatically compressed fullerite inside, while the model dealt with a diamond containing a fullerite inside. According to the calculated spectrum, the new model correlated very well with the experimental data.

"The developed model will help us to understand the nature of its unique properties and to help to systematically synthesize the new ultra-hard carbon materials, as well as to contribute to the further development of this promising field of science", said Pavel Sorokin, Doctor of Physical and Mathematical Science, head of the project (TISNCM, MISIS, MIPT).

Fullerite itself is not very hard; its bulk modulus is 1.5 times less than that of diamond. But when it’s compressed, its bulk modulus increases dramatically. To preserve this enhanced bulk modulus, the fullerite should always remain in such a compressed state. Using the results of simulations, the scientists can conduct targeted experiments to obtain an ultra-hard material.

Contacts and sources:
Ilyana Shaybakova
Moscow Institute of Physics and Technology