Daily Archives: January 6, 2017

New Process Quickly Analyzes Acrylamide in French Fries

A technique called “near-infrared spectroscopy” (NIRS) can rapidly estimate the amount of acrylamide in white-potato French fries, according to a study by U.S. Department of Agriculture (USDA) scientists and their North Carolina State University collaborators.

ARS scientists developed a method to rapidly, economically estimate the amount of acrylamide, a potential carcinogen, in white-potato French fries

ARS scientists developed a method to rapidly, economically estimate the amount of acrylamide, a potential carcinogen, in white-potato French fries

Acrylamide is a potentially toxic compound that forms in potatoes and other foods when they are fried, roasted or baked at high temperatures. The Food and Drug Administration (FDA) has issued recommendations to help the food industry reduce the amount of acrylamide in certain foods. According to the FDA, certain foods are likely to contain more acrylamide than others, including potato products such as French fries. Reducing acrylamide levels in certain fried foods can help consumers reduce the potential risk associated with this toxic compound.

Scientists at the Agricultural Research Service (ARS) Food Science Research Unit (FSRU) in Raleigh, North Carolina, work to reduce acrylamide while maintaining health-promoting compounds in foods.

The current process used to determine acrylamide levels in food requires sophisticated analytical techniques that take a long time and requires expensive equipment, according to FSRU food scientist Suzanne Johanningsmeier.

In a recent study, Johanningsmeier and her colleagues used NIRS technology to detect acrylamide in potato flour spiked with different levels of the compound. They then used NIRS to test and analyze French fries produced with various pretreatments and cooking times.

From these data, a predictive model was developed to rapidly estimate acrylamide content, which is also less expensive than current methods.

Food processors typically pay about $250 per sample to test French fries and other products for acrylamide, according to FSRU research leader Van-Den Truong. The cost per sample using the new model would be about $25.

The NIRS technique also gives potato breeders and processors a quicker, less expensive method to test and evaluate large numbers of potato hybrids for potential acrylamide formation, according to Johanningsmeier.

This research was supported by a USDA-National Institute of Food and Agriculture Specialty Crop Research Initiative Grant.

Read more about this research in the November 2016 issue of AgResearch magazine.

Source: ARS


The key to creating new treatments for type 2 diabetes may be hidden in platypus venom

Although not many people know that, platypuses are one of the few venomous mammals. There is a spur on the hind foot of male platypuses, which can cause a severe pain in humans. Now a new research from Australian universities showed that platypus venom could hold key to new treatments for type 2 diabetes.

Not everyone knows, but platypuses are venomous and its venom now can become the basis for new type 2 diabetes treatments. Image credit: Rainbow606 via Wikimedia, CC BY-SA 3.0

Not everyone knows, but platypuses are venomous and its venom now can become the basis for new type 2 diabetes treatments. Image credit: Rainbow606 via Wikimedia, CC BY-SA 3.0

Scientists found that the hormone, active in production of venom, is produced in the gut of the platypus to regulate blood glucose. It is called glucagon-like peptide-1 (GLP-1) and it can be found in both humans and animals. It stimulated release of insulin as a measure to regulate glucose content in blood. Unfortunately for type 2 diabetes patients, GLP-1 degrades within minutes, which for them is not enough to maintain a proper blood sugar balance. This is why scientists are trying to create a new kind of treatment, which would include a longer lasting form of the hormone. But here do you get one?

Scientists were surprised to find out that a good place to start searching for this hormone is in monotremes – Australia’s iconic platypus and echidna. As this research showed, their GLP-1 degrades much slower, because of entirely different mechanism behind it. It maybe because regulation of glucose content in the blood is not its only function – GLP-1 is actively involved in producing venom as well. Why this animal, generally considered peaceful, need venom? The answer is usual in the animal kingdom – to fight other males in the breading season.

This double function of GLP-1 hormone created an entirely different GLP-1 system. Associate Professor Briony Forbes, co-lead author of the study, explained: “The function in venom has most likely triggered the evolution of a stable form of GLP-1 in monotremes. Excitingly, stable GLP-1 molecules are highly desirable as potential type 2 diabetes treatments”. Scientists are confident that these findings can pave the way to new diabetes treatments, although more research is needed to find out how.

Long lasting GLP-1 hormone is the key to the new treatments for type 2 diabetes. As usual, searching for answers in nature is the best way to go. However, this research is only the proof that needed solutions may be found in platypuses and possibly echidnas, and more research is going to be needed to develop innovative treatments for type 2 diabetes.

Source: adelaide.edu.au

NRL Develops Novel Monolayer Ferroelectric Hybrid Structures

Scientists at the U.S. Naval Research Laboratory (NRL), Materials Science and Technology Division, have demonstrated that the intensity and spectral composition of the photoluminescence emitted from a single monolayer of tungsten disulphide (WS2) can be spatially controlled by the polarization domains in an adjacent film of the ferroelectric material lead zirconium titanate (PZT).

These domains are written in the PZT using a conductive atomic force microscope, and the photoluminescence (PL) is measured in air at room temperature. Because the polarization domain wall width in a ferroelectric can be as low as 1-10 nm, this approach enables spatial modulation of PL intensity and the corresponding carrier populations with potential for nanoscale resolution.

Domains consisting of electric polarization dipoles are written in a checkerboard pattern into a thin film of lead zirconium titanate (PZT) with a conductive atomic force microscope, and imaged with the same instrument (left panel). Both intensity and spectral distribution of the photoluminescence emitted from a monolayer of tungsten disulphide (WS2) transferred onto the PZT surface is strongly modulated by these polarization domains (right panel). (U.S. Naval Research Laboratory)

Single monolayer transition metal dichalcogenides (TMDs) such as WS2 exhibit striking optical properties due to their direct band gap. The dielectric screening is very low due to their two dimensional (2D) character, and thus their properties are strongly affected by their immediate environment, and can be modified and controlled by variations in local charge density due to adsorbates or electrostatic gating. This has generated keen interest in a wide variety of electronic and optical device applications.

The NRL scientist used a conducting atomic force microscope to write polarization domains into a PZT film in a checkerboard pattern. In each domain, the polarization dipole points either up out of the surface plane or down into the surface plane, and produces either positive or negative charge on the PZT surface, respectively. The team then transferred monolayer WS2 that they had grown by chemical vapor deposition techniques onto the PZT film.

They found that the PL intensity from the WS2 is high only from the areas over domains in the PZT where the polarization dipole points out of the surface plane, as shown in the adjacent figure. Further analysis revealed that the spectral composition of the PL was also strongly affected — the spectra from the “up” domains were dominated by neutral exciton contributions (a bound state of an electron and hole arising from Coulomb interaction), while those from the “down” domains were dominated by negatively charged exciton, or trion, contributions (an exciton with an extra electron).

“Fabricating these hybrid 2D/3D ferroelectric heterostructures enables one to purposefully design and modulate adjacent populations of trions and neutral excitons, creating lateral domains in any geometry of choice” notes Dr. Berend Jonker, senior scientist and principal investigator. Dr. Connie Li, lead author of the study, further points out: “Because the FE domains can be rewritten with an atomic force microscope and are non-volatile, this enables spatial modulation of the TMD properties with nanometer scale resolution.”

The payoff includes development of TMD materials and hybrid 2D/3D heterostructures with new functionality relevant to the DoD mission, including ultra-low power electronics, non-volatile optical memory and quantum computation for future DoD applications in information processing and sensing. The research results are reported in the December 4, 2016, issue of ACS Omega (DOI: 10.1021/acsomega.6b00302), the open access journal of the American Chemical Society. The paper was also selected as an ACS Editors’ Choice featured paper. The research team included Dr. Connie Li, Dr. Kathleen McCreary, and Dr. Berend Jonker from the Magnetoelectronic Materials Devices Section in the Materials Science and Technology Division at NRL.

Source: NRL

A Box of ‘Black Magic’ to Study Earth from Space

RainCube, due to fly in 2017, forced JPL’s engineers to get creative in order to squeeze an antenna into a CubeSat. Credits: Tyvak/Jonathan Sauder/NASA/JPL-Caltech.

RainCube, due to fly in 2017, forced JPL’s engineers to get creative in order to squeeze an antenna into a CubeSat.
Credits: Tyvak/Jonathan Sauder/NASA/JPL-Caltech.

Black magic.

That’s what radiofrequency engineers call the mysterious forces guiding communications over the air. These forces involve complex physics and are difficult enough to master on Earth. They only get more baffling when you’re beaming signals into space.

Until now, the shape of choice for casting this “magic” has been the parabolic dish. The bigger the antenna dish, the better it is at “catching” or transmitting signals from far away.

But CubeSats are changing that. These spacecraft are meant to be light, cheap and extremely small: most aren’t much bigger than a cereal box. Suddenly, antenna designers have to pack their “black magic” into a device where there’s no room for a dish — let alone much else.

“It’s like pulling a rabbit out of a hat,” said Nacer Chahat, a specialist in antenna design at NASA’s Jet Propulsion Laboratory, Pasadena, California. “Shrinking the size of the radar is a challenge for NASA. As space engineers, we usually have lots of volume, so building antennas packed into a small volume isn’t something we’re trained to do.”

Challenge accepted.

RainCube’s radiofrequency lead Nacer Chahat (right) and mechanical engineer lead Jonathan Sauder (left) observe the CubeSat’s deployed antenna. Credits: NASA/JPL-Caltech

RainCube’s radiofrequency lead Nacer Chahat (right) and mechanical engineer lead Jonathan Sauder (left) observe the CubeSat’s deployed antenna.
Credits: NASA/JPL-Caltech

Chahat and his team have been pushing the limits of antenna designs, and recently worked with a CubeSat team on the antenna for Radar In a CubeSat (RainCube), a technology demonstration mission scheduled for launch in 2018. RainCube’s distinctive antenna looks a little like an umbrella stuffed into a jack-in-the-box; when open, its ribs extend out of a canister and splay out a golden mesh.

As its name suggests, RainCube will use radar to measure rain and snowfall. CubeSats are measured in increments of 1U (A CubeSat unit, or 1U, is roughly equivalent to a 4-inch cubic box, or 10x10x10 cubic centimeters). The RainCube antenna has to be small enough to be crammed into a 1.5U container. Think of it as an antenna in a can, with no spare room for anything else.

“Large, deployable antennas that can be stowed in a small volume are a key technology for radar missions,” said JPL’s Eva Peral, principal investigator for RainCube. “They open a new realm of possibilities for science advancement and unique applications.”

To maintain its relatively small size, the antenna relies on the high-frequency, Ka-band wavelength — something that’s still rare for NASA CubeSats, but is ideally suited to RainCube. But Ka-band has other uses besides radar. It allows for an exponential increase in data transfer over long distances, making it the perfect tool for telecommunications.

Ka-band allows for data rates about 16 times higher than X-band, the current standard on most NASA spacecraft.

In that sense, the development of RainCube’s antenna can test the use of CubeSats more generally. While most have been limited to simple studies in near-Earth orbit, the right technology could allow them to be used as far away as Mars or beyond. That might open up CubeSats to a whole range of future missions.

RainCube’s umbrella-like antenna deploys out of its 1.5U canister. Credits: NASA/JPL-Caltech

RainCube’s umbrella-like antenna deploys out of its 1.5U canister.
Credits: NASA/JPL-Caltech

“To enable the next step in CubeSat evolution, you need this kind of technology,” said JPL’s Jonathan Sauder, mechanical engineer lead for the RainCube antenna.

Chahat was brought on to the RainCube team after he worked on another innovative antenna design. The MarCO (Mars Cube One) mission consists of a pair of Cubesats that have been proposed to fly in 2018 with NASA’s InSight lander, which would measure the Red Planet’s tectonics for the first time. While InSight is touching down, the two MarCO CubeSats would relay information about the landing back to Earth. Just like RainCube, MarCO is primarily a technology demonstration; it would test how future missions could use CubeSats to carry communication relays with them, enabling researchers to know what’s happening on the ground much faster.

The MarCO design looks nothing like a typical antenna. In place of a round dish are three flat panels dotted with reflective material. The shape and size of these dots form concentric rings that mimic the curve of a dish. Just as a dish might, this mosaic pattern of dots focuses the signal radiated from the antenna’s feed towards Earth.

“New technologies like these allow NASA and JPL to do more with less,” said JPL’s John Baker, program manager for MarCO. “We want to make it possible to explore anywhere we want in the solar system.”

Both RainCube and MarCO highlight creative workarounds to the size limits of CubeSats. The next trick for Chahat and his colleagues will be combining those designs into an even bigger antenna: a reflectarray ranging 3.3 feet by 3.3 feet (1 meter by 1 meter) and made up of 15 flat panels. These segmented panels would unfold like the flat surface of MarCo’s, while the antenna’s feed would telescope out like RainCube’s antenna. This antenna would be called OMERA, short for the One Meter Reflectarray.

Source: NASA


Berkeley SETI turns Australian telescope on nearest exoplanet to Earth

Breakthrough Listen, the UC Berkeley-led 10-year, $100 million search for intelligent life beyond Earth, inaugurated its observations with the Parkes Radio Telescope in Australia by homing in on our nearest extrasolar planet, Proxima b, the main destination for a sister project called Breakthrough Starshot.

The Parkes radio telescope in New South Wales, Australia. Shaun Amy photo, 2005.

The Parkes radio telescope in New South Wales, Australia. Shaun Amy photo, 2005.

Launched in 2015 by internet entrepreneur Yuri Milner and physicist Stephen Hawking, Breakthrough Listen has been observing the Northern Hemisphere for nine months at the Green Bank Telescope in West Virginia. One of its targets includes the mysterious Tabby’s star, which some have speculated is host to an advanced civilization that has built massive structures around the star.

A team of scientists and engineers from UC Berkeley’s SETI Research Center deployed similar signal-processing hardware at the Parkes telescope in New South Wales, bringing Breakthrough Listen’s unprecedented search tools to a wide range of sky inaccessible from West Virginia, including the center of our Milky Way galaxy, large swaths of the galactic plane and numerous other galaxies in the nearby universe.

“The addition of Parkes is an important milestone,” said Yuri Milner, founder of the Breakthrough Initiatives, which include Breakthrough Listen. “These major instruments are the ears of planet Earth, and now they are listening for signs of other civilizations.”

After 14 days of commissioning and test observations, first light for Breakthrough Listen at Parkes was achieved on Nov. 7 with an observation of a newly discovered Earth-size planet orbiting the star nearest to Earth, Proxima Centauri. A red dwarf star 4.3 light-years from Earth, Proxima Centauri is now known to have a planet, designated Proxima b, within its habitable zone, the region where water could exist in liquid form on the planet’s surface.

Such “exo-Earths” (habitable zone exoplanets) are among the primary targets for Breakthrough Listen, and Proxima b is the primary target for Breakthrough Listen’s sister initiative, Breakthrough Starshot, which is developing the technology to send gram-size spacecraft to nearby stars.

“The chances of any particular planet hosting intelligent life-forms are probably minuscule,” said Andrew Siemion, director of UC Berkeley SETI Research Center. “But once we knew there was a planet right next door, we had to ask the question, and it was a fitting first observation for Parkes. To find a civilization just 4.2 light years away would change everything.”

The Parkes radio telescope is part of the Australia Telescope National Facility, owned and managed by Australia’s Commonwealth Scientific and Industrial Research Organization, or CSIRO.

“Parkes’ unique view of the southern sky, and cutting-edge instrumentation, means we have a great opportunity to contribute to the search for extraterrestrial life,” said Douglas Bock, Director of CSIRO Astronomy and Space Science.

Breakthrough Listen also looks for optical signals from other civilizations using the Automated Planet Finder at the University of California’s Lick Observatory near San Jose, California. On Oct. 12, the project announced it will be joining forces with the new FAST telescope in China – the world’s largest filled-aperture radio receiver – to coordinate their searches for artificial signals. The partnership represents a major step toward establishing a fully connected, global search for intelligent life in the universe.

Source: UC Berkeley