Welcome to the Saturday Science Edition of Overnight News Digest
Overnight News Digest is a regular daily feature which provides noteworthy news items and commentary from around the world. The editorial staff includes side pocket, maggiejean, wader, Doctor RJ, rfall, and JML9999.
Neon Vincent is our editor-in-chief.
Special thanks go to Magnifico for starting this venerable series.
Astronomy
US-China Space Freeze May Thaw with Historic New Experiment
A Chinese experiment is being readied for launch toward the International Space Station (ISS) in what could be the forerunner of a larger space-cooperation agenda between the United States and China. NanoRacks, a Houston-based company that helps commercial companies make use of the space station, has signed a historic agreement with the Beijing Institute of Technology to fly Chinese DNA research to the orbiting outpost next year. No commercial Chinese payload has ever flown to the orbiting lab before. [...] Cooperation prohibited Over the past few years, the law has prohibited NASA and the White House Office of Science and Technology Policy (OSTP) from cooperating with China on space activities. That prohibition was originally signed into NASA-funding appropriations bills by Republican Congressman Frank Wolf (Virginia), who chaired the House Appropriations Commerce-Justice-Science subcommittee before retiring last year. The final law that Wolf put in place — P.L. 113-235, the Consolidated and Further Continuing Appropriations Act, 2015, which is in effect today — states that no funds may be spent by NASA or OSTP to "develop, design, plan, promulgate, implement or execute a bilateral policy, program, order or contract of any kind to participate, collaborate or coordinate bilaterally in any way with China or any Chinese-owned company unless such activities are specifically authorized by law after the date of enactment of this act." However, the new NanoRacks deal is a commercial arrangement, and experts consider it legal. space.com
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Robotic Flyers: The Future of Space Exploration?
Flying robot explorers could one day grace the skies of other worlds. Quadcopters, the four-propeller drones that have become a familiar sight in terrestrial skies, may be the next big thing in space exploration. Engineers based at NASA’s Kennedy Space Center on the Florida Space Coast are working on the next generation of robotic scouts to take planetary exploration airborne. The facility, known as Swamp Works, is designing small flying probes which will be capable of reaching hard-to-access spots, such as crater walls or crevasses. Engineers are designing these prototypes for use in harsh environments. Navigation based on the Global Positioning System (GPS) would be unavailable for an EAF based on Mars or an asteroid. Moreover, the flyers would have to be completely autonomous, able to make snap decisions on their own as they operate on surfaces of worlds several light-minutes away from Mission Control here on Earth. [...] Though Swamp Works is conducting initial tests using ducted fan motors, the flyers will ultimately maneuver in the mostly airless environments of the Moon, Mars, or an asteroid using cold-gas jets. The flyers would utilize steam or nitrogen gas to maneuver as they venture out for small samples, returning to a larger base vessel for periodic recharging.
“One of the reasons we chose the propellant systems that we did is so they could replenish themselves via a method known as In Situ Resource Utilization (ISRU),” says Mike DuPuis, co-investigator for the Extreme Access Flyer (EAF) project. Future missions could ultimately scale up this technology to mine for vital resources — such as water — ahead of the arrival of astronauts. “Every kilogram mined on-site is a kilogram that astronauts wouldn’t have to bring with them,” DuPuis said.
skyandtelescope.com
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Biology
Ant Knows How To Self-Medicate To Fight Off Fungal Infection
It’s a nasty poison, but for an ant fighting off a dangerous fungus, it could be the only hope. For the first time, ants have been seen self-medicating – on food rich in hydrogen peroxide. Large, dense colonies of social insects like ants and bees can be particularly vulnerable to parasite infections and fungal diseases. One way to manage this might be to ingest otherwise harmful substances to fight the infections, but conclusive evidence of this behaviour in insects had been elusive. Nick Bos and his colleagues at the University of Helsinki, Finland, have now shown that ants choose to eat hydrogen peroxide if they have a dangerous fungal disease – and are more likely to survive as a result. [...] When the ants were offered a choice, the healthy ants tended to avoid the spiked food, says Bos. But the infected ants ate more of the solution containing hydrogen peroxide, and chose their dosage carefully. When the toxic solution was weak, the infected ants tended to opt for equal amounts of this food and the pure food. When a stronger solution was offered, they only fed on it around a quarter of the time. (h/t Besame) newscientist.com
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Firefly Protein Enables Visualization Of Roots In Soil
Plants form a vast network of below-ground roots that search soil for needed resources. The structure and function of this root network can be highly adapted to particular environments such as desert soils where plants like Mesquite develop tap roots capable of digging 50 meters deep to capture precious water resources. Excavation of root systems reveals these kinds of adaptations but is laborious, time consuming, and does not provide information on how growing roots behave. [...] Despite their importance, roots remain one of the most mysterious parts of the plant. They cannot easily be studied since they grow hidden in soil. Most of what scientists know about roots today comes from either digging up roots, or growing them in transparent media that do not reflect their natural environment.
"To visualize the intricate growth patterns and functions of roots we needed to develop a different approach," Dinneny explained. "We were very mindful that the method had to allow us to vary conditions, in order to present roots with different combinations of environmental conditions that simulate important stresses such as drought or low-fertility soil."
The team's imaging system is called GLO-Roots (for Growth and Luminescence Observatory for Roots). It is an integrated platform for growing plants in soil in custom-built vessels, imaging roots using bioluminescence, and analyzing root growth, architecture and gene expression using software designed in collaboration with Guillaume Lobet at the University of Liège. The GLO-Roots system involved the genetic engineering of plants to produce an enzyme from fireflies called luciferase, which causes them to glow in the dark of the soil. Light-sensitive cameras then detect the light emitted by the roots and allow researchers to discriminate between the roots and the surrounding soil. Using multiple genetically encoded luciferases, each one emitting light of a different wavelength, the team was able to simultaneously track whole root system architecture and the gene expression of adult plants. biologynews.net
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Chemistry
Paper Device Tracks Fracking Pollution
Scientists in the US have developed a simple paper-based sensor for detecting bromide ions in water. The device could be used to check if fracking fluids have seeped into water supplies. Fracking involves forcing large amounts of fracking fluid – a mix of water, sand, biocides and other chemicals – into shale fractures at high pressure to extract shale gas. The resulting wastewater contains high concentrations of toxic chemicals including bromide, chloride and iodide ions and organic pollutants, and some wells can use around 17,000 cubic metres of water. Municipal treatment plants cannot cope with this volume of waste, and toxic halogenated byproducts can be created by the disinfection process. There are concerns that fracking wastewater will reach drinking water sources but currently there are no sensors for this specific type of contamination. Most water samples contain around 1ppm bromide but concentrations as high as 56ppm have been recorded in fracking wastewater. Now, Vincent Remcho and his team at Oregon State University in the US have made a simple device to test for these characteristically high levels of bromide ions. [...] The device consists of 3 sheets of filter paper stacked vertically, each with a dried spot of reagent: the top sheet contains a buffer, and the middle and bottom sheet contain phenol red and chloramine T trihydrate, respectively. Contaminated water samples dropped onto the top sheet of paper initiate a yellow to blue colour change as chloramine T oxidizes any bromide in the sample which leads to the bromination of phenol red. The colour change on the bottom sheet is proportional to the bromide concentration and can be recorded with a portable detector and the result wirelessly delivered to a smartphone. ‘This work demonstrates that our device fabrication methods and detection approaches are practical and have potential for application not only in environmental monitoring but also in medical monitoring and pharmaceutical adulteration studies’ says Remcho. rsc.org
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Growing Symmetrical Gold Nanostars
[...] Symmetrical or not, nanosized gold nuggets with jutting arms are useful for selectively killing cancer cells and boosting surface-enhanced Raman spectroscopy (SERS) signals. Yet previous nanostar-building methods create particles with wildly asymmetrical shapes, leading to inconsistent performance in SERS or in cancer therapies. So Xianmao Lu’s group at the National University of Singapore made symmetrical nanostars by starting with a known synthesis for symmetrical gold icosahedral seeds, each with 20 faces [...]. Then they place the gold kernels in a solution containing dimethylamine (DMA). DMA binds with the gold surface and helps control the growth of six-sided pyramids on each face, forming 20 symmetrical spikes. The method results in consistently shaped nanostars; the team estimates that 95% have the same geometry. The unique symmetry of these nanostars allows five of its arms to land on a flat surface. The researchers then tested their performance in SERS. First the team scattered 4-mercaptobenzoic acid, a standard SERS reference compound, on a gold nanosheet and then added the stars. As the stars landed on the flat sheet, they trapped the analyte molecules inside their tips and greatly magnified the signal. acs.org
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Earth Science
What Do You Do With A Bear That Kills A Person?
"Jack-booted executioner" is not a title that Yellowstone National Park Superintendent Dan Wenk ever aspired to own. But as a torrent of emails and phone calls began flooding his office last week—most from wildlife lovers in a desperate attempt to keep a mother grizzly bear alive—Wenk was given that label, and far worse. Even legendary primatologist Jane Goodall, who has become a huge fan of grizzlies in the Greater Yellowstone Ecosystem, reached out to Wenk from her home in Bournemouth, England, pleading with him to spare a sow whose tragic encounter with a hiker had elevated her into the realm of international cause célèbre. "In my 40 years working for the National Park Service, I have never encountered anything like the emotional outpouring we received in response to the fate of this bear," Wenk said, acknowledging that members of his staff were also left shell-shocked. [I encourage reading the entire article - Editor] nationalgeographic.com
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Air Pollution In China Is Bad, REALLY Bad!
There can be no question that the epic story of our time is our struggle to endure against the threatening demons of our own creation. In that story, China must be the sleeping giant. As the story opens, the giant awakens, searching for a way to improve the livelihood of his people, inadvertently trampling on a number of the Earth’s delicate structures in doing so. Realizing this, a second awakening occurs. But can the giant change direction quickly enough, before too much harm is done? The damage that re-directed the giant was the realization that fossil fuel emissions, particularly from coal-fired power plants, are pushing atmospheric carbon levels to dangerously high levels. China’s emissions have grown 7 percent annually — far faster than the rest of the world, which is growing at 2.8 percent. Now that we all realize that emissions have to start decreasing, fast, China has pledged to achieve peak emissions by 2030, after which its emissions will begin to decrease. But another harm, more immediate and more deadly, has appeared on the scene. Air pollution levels in China have reached catastrophic proportions. According to research newly published by Berkeley Earth, air pollution kills more than 4,000 people every day in China. That’s 1.6 million people per year, a full 17 percent of deaths from all causes. This is a terrible tragedy. As much as 38 percent of China’s population live in a situation where the air quality is considered “unhealthy” by U.S. standards, based on ground-level measurements. The study maps this pollution in unprecedented detail. The biggest culprit is particulate matter, known as PM 2.5, which refers to the size of the particles in microns. According to the U.S. EPA, PM 2.5 consists of multiple species including ammonium sulfate, ammonium nitrate, carbon and crustal materials, which are primarily soil and ash. PM 2.5 is the smallest particle size the EPA tracks, and it is the most dangerous because of its ability to penetrate the lungs and enter the bloodstream. Associated medical issues include: “decreased lung function, increased respiratory symptoms, cardiac arrythmias (heartbeat irregularities), heart attacks, hospital admissions or emergency room visits for heart or lung disease, and premature death.” enn.com
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Physics
A Magnetic Wormhole
Abstract: Wormholes are fascinating cosmological objects that can connect two distant regions of the universe. Because of their intriguing nature, constructing a wormhole in a lab seems a formidable task. A theoretical proposal by Greenleaf et al. presented a strategy to build a wormhole for electromagnetic waves. Based on metamaterials, it could allow electromagnetic wave propagation between two points in space through an invisible tunnel. However, an actual realization has not been possible until now. Here we construct and experimentally demonstrate a magnetostatic wormhole. Using magnetic metamaterials and metasurfaces, our wormhole transfers the magnetic field from one point in space to another through a path that is magnetically undetectable. We experimentally show that the magnetic field from a source at one end of the wormhole appears at the other end as an isolated magnetic monopolar field, creating the illusion of a magnetic field propagating through a tunnel outside the 3D space. Practical applications of the results can be envisaged, including medical techniques based on magnetism. nature.com
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Tiny Fountain Of Atoms Sparks Big Insights Into Dark Energy
It's a study in contrasts. For more than a decade, physicists have been puzzling over dark energy, the mysterious stuff that’s blowing space apart and has been detected only by studying the universe on the largest scales. Now, researchers have probed its properties using about the smallest tools available—atoms falling freely in a vacuum chamber. The experiment, reported today in Science, doesn't reveal what dark energy is, but it helps nail down what it isn't. In particular, it narrows the prospects for one popular idea: that dark energy resides in hypothesized "chameleon particles" hiding in plain sight. [...] But what is dark energy? There are two possibilities. It could be energy hidden in the vacuum of empty space itself—a cosmological constant, as Albert Einstein hypothesized in 1917. Or it could be a quantum field that fills space and blows it up like a balloon. Both alternatives have problems. Given the standard model of particle physics, theorists can calculate what the cosmological constant should be, and they get a value vastly too big to explain the relatively modest acceleration—suggesting some unknown physics just zeroes it out. On the other hand, the presence of a quantum field would affect things like the orbits of the planets in the solar system—but dark energy doesn’t seem to. That's where chameleon particles come in. The hypothetical particles would make up just such a quantum field, but they would interact with matter in a way that would make the field vanish wherever the density of matter was high. Thus the field would exert no noticeable effect on things like planets. "The chameleon, like many other theoretical ideas, has a small probability of being there," says Justin Khoury, a theoretical cosmologist at the University of Pennsylvania and co-inventor of the concept. "Nonetheless we should test it if we can." That's just what Khoury, Holger Müller, an atomic physicist at the University of California, Berkeley, and colleagues have done. To search for a chameleon field, they studied the interactions between an aluminum sphere 9.5 millimeters in diameter and a puff of 10 million ultracold cesium atoms within a vacuum chamber. If there were a chameleon field within the vacuum, then the sphere would squash it. And like a bowling ball on a trampoline, the sphere would bend the field just outside its surface, causing the field’s strength to taper to zero. The cloud of atoms would slide down the sloping field, experiencing a short-range force toward the sphere. Crucially, the cloud itself was not dense enough to suppress the field and spoil the effect. "In the simplest terms, we're looking for a funny force between the sphere and the atoms," Müller says. sciencemag
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