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
Oxygen On Exoplanets May Not Mean Alien Life
Although scientists have long considered oxygen a sign that life exists on an alien planet, new research suggests the element could be produced without it. Oxygen may function as a sign of life on Earth, but that's not necessarily the case for planets around other stars. The new research shows that the interaction of titanium oxide with water could produce oxygen in the atmosphere of an exoplanet without the involvement of living organisms. "Although oxygen is still one of the possible biomarkers, it becomes necessary to look for new biomarkers besides oxygen," Norio Narita, of the National Institutes of Natural Science in Japan, said in a statement. Narita studied the role of titanium oxide, or titania, in the formation of oxygen in the atmosphere of a planet. [...] Titania is a naturally occurring substance present in meteorites and on Earth's moon. It forms as dust outflows around evolving low- and medium-mass stars, and through supernovae, and is thought to be common in exoplanet systems. The amount of titania on the surface of a planet or moon would vary based on the number of impacts each body received. According to the research, an Earth-like planet orbiting a sunlike star would need only enough titania to cover about 0.05 percent of the planet's surface to create the same amount of oxygen as in Earth's atmosphere. Planets that had oceans and orbited dimmer stars would need to have only about 3 percent of the surface covered with titania for similar results. space.com
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Saturn’s Moon Titan
In ancient Greek lore, the Titans were giant deities of incredible strength who ruled during the legendary Golden Age and gave birth to the Olympian gods we all know and love. Saturn‘s largest moon, known as Titan, is therefore appropriately named. In addition to being Saturn’s largest moon – and the second-largest moon in the Solar System (after Jupiter’s moon Ganymede) – it is larger by volume than even the smallest planet, Mercury. Beyond its size, Titan is also fascinating because it is the only natural satellite known to have a dense atmosphere, a fact which has made it very difficult to study until recently. On top of all that, it is the only object other than Earth where clear evidence of stable bodies of surface liquid has been found. All of this makes Titan the focal point of a great deal of curiosity, and a prime location for future scientific missions. [...] Composition and Surface Features: Though similar in composition to Dione and Enceladus, it is denser due to gravitational compression. In terms of diameter and mass (and hence density) Titan is more similar to the Jovian moons of Ganymede and Callisto. Based on its bulk density of 1.88 g/cm3, Titan’s bulk composition is believed to consist of half water ice and half rocky material. It’s internal makeup is likely differentiated into several layers with a 3,400-kilometre (2,100 mi) rocky center surrounded by several layers composed of different crystal forms of ice. Based on evidence provided by the Cassini-Huygens mission in 2005, it is believed that Titan may also have a subsurface ocean which exists between the crust and the deeper layers made up of high-pressure ice. This subsurface ocean is believed to be made up of water and ammonia, which allows the water to remain in a liquid state even at a temperature as low as 176 K (-97 °C). Other evidence provided by the Cassini mission includes a systematic shift of the moon’s surface features (between October 2005 and May 2007) which suggests that the crust is decoupled from the interior – possibly by a liquid layer in between – as well as the way the gravity field varies as Titan orbits Saturn. universetoday.com
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Biology
Trade In Invasive Plants Is Blossoming
Goldenrod, Himalayan balsam, Chinese windmill palm: three plants, one problem. All are native to continents other than Europe, but were introduced to Switzerland as garden or ornamental plants. At some point they "escaped" into the wild, where they now threaten the native flora. This phenomenon isn't limited to Switzerland: biological invasions happen on every continent every day. A major driver of this is global trade, which is increasingly shifting to the internet and being conducted on auction platforms like eBay. As a result, one click is all it takes to spread potentially invasive plants from continent to continent -- and unintentionally encouraging biological invasions. Monitoring online auctions But how much of the global trade in invasive plants is done online? To get an estimate, a group of four researchers at ETH Zurich led by Christoph Kueffer, senior lecturer at the Institute of Integrative Biology, monitored online trade of about two thirds of the world's flora on eBay plus nine other online trading platforms. For 50 days, the researchers tracked which plant species were offered for sale in various countries, and how often. Their efforts were aided by a software program developed especially for the study. In addition, the researchers looked to lists of invasive plants, kept by various bodies including the International Union for the Conservation of Nature (IUCN), for information about whether the plants for sale were classified as invasive somewhere in the world. sciencedaily.com
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Common Mealworms Can Live On Diet Of Polystyrene
Mealworms from different sources chew and eat Styrofoam, a common polystyrene product,” the scientists said. “The Styrofoam was efficiently degraded in the larval gut within a retention time of less than 24 hours. Fed with Styrofoam as the sole diet, the larvae lived as well as those fed with a normal diet over a period of one month.” [...] In the lab, 100 mealworms ate between 34 and 39 milligrams of Styrofoam per day. The worms converted about half of the Styrofoam into carbon dioxide, as they would with any food source. Within 24 hours, they excreted the bulk of the remaining plastic as biodegraded fragments that look similar to tiny rabbit droppings.
“Mealworms fed a steady diet of Styrofoam were as healthy as those eating a normal diet and their waste appeared to be safe to use as soil for crops,” said co-author Dr Wei-Min Wu of Stanford University.
sci-news.com
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Chemistry
Perfumery: The Molecular Art Form
There is no form of artistic expression more intimately connected with chemistry than perfumery. While descriptions of fragrances invoke concepts familiar to musicians, such as notes and chords, it is of course not a spectrum of sound wave frequencies a perfumer must manipulate in their work but ensembles of volatile organic molecules. A perfumery accord is a blend of fragrance materials with common facets, so that the overall effect is one of a coherent, ‘consonant’ smell, in which none of the individual constituents – which may be naturally derived ingredients or synthetic aroma chemicals – are easily distinguished. In a well-designed perfume, this vertical arrangement will also evolve horizontally in time as a result of the materials’ different volatilities. The principle is illustrated by the ‘chypre’, or Cyprus, fragrance genre (for example Guerlain’s Mitsouko or Chanel’s Pour monsieur). Chypres are characterised by a bergamot top note, the most volatile and first to be perceived, whose citrus quality allows it to blend with labdanum. This green resinous component forms the heart of the fragrance, which in turn rests on an oakmoss base of a dry earthy-green character, persisting on the skin long after the other components have evaporated. If it is the perfumer’s job to paint a scent using the fragrance notes available to them, it falls to the chemist to expand the palette of notes to use. In this respect, both organic synthesis and analysis – the structural elucidation of aroma compounds present in nature – are invaluable. Total synthesis can provide access to materials for which it would be prohibitively expensive or unsustainable to rely on natural sources for supply. Indeed, given the fact that tonnes of rose or jasmine flowers are required to produce mere kilograms of perfumery extracts, it should not be surprising that floral accords in modern perfumes often comprise reconstructions of natural floral aromas using large proportions of artificially synthesised ingredients. It is the synthetic nature of modern perfumery, however, that makes it so exciting. Assembling smells, molecule by molecule, is far from simply being a way of providing cheaper copies of natural odours. The natural aroma of rose, for example, consists of three major components: 2-phenylethanol, geraniol and citronellol.1 Alongside these, numerous other molecules add facets to the scent, resulting in the subtle nuances that comprise a particular flower or extract’s character. Rose oxide, for example, imparts a dry green top note. A skilled perfumer with access to these synthetics can not only reconstruct the smell of a rose, but also shape its character by altering the amount of each compound present in the formula, or by adding new ones. In this way a completely unique interpretation of rose scent results from the perfumer’s artistic expression. One could compare the fluorescent, damascone-laced rose of Estée Lauder’s Knowing with post-impressionist Paul Cézanne’s use of unnatural outlines in his still lifes, which add emphasis to the form of fruits and flowers. rsc.org
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Researchers Create Self-Propelled Powder To Stop Bleeding
UBC researchers have created the first self-propelled particles capable of delivering coagulants against the flow of blood to treat severe bleeding, a potentially huge advancement in trauma care.
"Bleeding is the number one killer of young people, and maternal death from postpartum hemorrhage can be as high as one in 50 births in low resource settings so these are extreme problems," explains Christian Kastrup, an assistant professor in the Department of Biochemistry and Molecular Biology and the Michael Smith Laboratories at the University of British Columbia. [...] "People have developed hundreds of agents that can clot blood but the issue is that it's hard to push these therapies against severe blood flow, especially far enough upstream to reach the leaking vessels. Here, for the first time, we've come up with an agent that can do that," Kastrup said.
Kastrup teamed up with a group of researchers, biochemical engineers and emergency physicians to develop simple, gas-generating calcium carbonate micro-particles that can be applied in powder form to stop critical bleeding. The particles work by releasing carbon dioxide gas, like antacid tablets, to propel them toward the source of bleeding. The carbonate forms porous micro particles that can bind with a clotting agent known as tranexamic acid, and transport it through wounds and deep into the damaged tissue. phys,org
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Earth Science
Sierra Nevada Snowpack At Historic Low
On April 1, California Governor Jerry Brown stood in a Sierra Nevada meadow atop parched, brown grass — at an elevation of 6,800 feet, where there would normally be five feet of snow at that time of year — and announced the state’s first-ever mandatory water restrictions. The Golden State is still in the grip of a severe drought that began in 2012, and new research suggests it is one of the worst in centuries. The day Gov. Brown announced the statewide water restrictions, snowpack in the Sierra Nevadas was reported to be at just 5 percent of its historical average, as calculated from records dating back to the 1930s. Now a team of researchers at the University of Arizona has found that snowpack in the Sierra Nevada mountain range, which is responsible for 30 percent of the state’s water supply, is actually at the lowest it’s been in five centuries. The results of the team’s study were recently published in the journal Nature Climate Change. California, known for its dry summer climate, gets about 80 percent of its precipitation in winter months. The historically low snowpack in 2015 stems from a lack of winter precipitation and record high temperatures, according to the report. enn.com
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Elon Musk-Backed SolarCity Touts 'World's Most Efficient Rooftop Solar Panel'
Solar power company SolarCity is now manufacturing what it claims is the highest-efficiency rooftop solar panel on the market — and it plans to make record numbers of them as well. The new panel has an efficiency rating of 22 percent, the company said, meaning 22 percent of the energy hitting the cell is converted to electricity (as opposed to bouncing off or producing waste heat). The company called it the "world's most efficient rooftop solar panel." It isn't a huge jump over the competition — panels from SunPower reach 21.5 percent — but SolarCity also described a new manufacturing process that reduces the cost significantly, bringing it down to about 50 cents per watt versus 55 or 60 cents in competing systems. Since panels generally have several thousand watts, such seemingly minor savings add up quickly. SolarCity CTO Peter Rive spoke in more detail about the panel and manufacturing process in an interview with Greentech Media. They're still expensive, though, and in a separate blog post the company stressed the need for alternative pricing structures for solar power — community-owned installations, for instance, or leased systems that cost less than an ordinary electric bill. nbcnews.com
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Physics
Ferroelectricity Discovered On The Nanoscale
Ferroelectricity can exist in a sheet of material just a few nanometres thick. This new and unexpected discovery by researchers in the US and South Korea could help in the development of new materials for nanoscale electronics. Ferroelectric materials have permanent electric dipole moments – much like their ferromagnetic counterparts, which have permanent magnetic dipole moments. Ferroelectrics have the potential to be used in a wide range of devices because their dipole moments can be oriented using electric fields, which are much easier to create than the magnetic fields used to manipulate ferromagnetic materials. One possible application is memory chips that store data in terms of the polarization of ferroelectric thin films. A major problem, however, is that these materials cease to be ferroelectric as they become very thin, which limits their usefulness in modern electronic devices. The researchers, led by Chang Beom Eom of the University of Wisconsin–Madison, have found that a thin film of a material that is normally not electrically polarized can be made polar by taking advantage of existing tiny polar nanoregions within the material. "This happens when the film is made so thin that its whole volume is occupied by these nanoregions," explains Eom. "When these are electrically aligned in one direction, this leads to a net polarization – and the material becomes ferroelectric." physicsworld.com
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Novel Nanostructures Could Usher In Touchless Displays
In a world where the “swipe” has become a dominant computer interface method along with moving and clicking the mouse, the question becomes what’s next? For researchers at Stuttgart’s Max Planck Institute for Solid State Research and LMU Munich, Germany, the answer continues to be a swipe, but one in which you don’t actually need to touch the screen with your finger. Researchers call these no-contact computer screens touchless positioning interfaces (TPI). [...] While touchless displays raise the question of whether every finger that passes by a display’s surface is really intended to interface with the computer, the researchers believe this new interface will address the problems of mechanical wear suffered by today’s touch screens over time, as well as concerns over screens, especially at ATMs, being transmission vectors for viruses and bacteria. Computer hardware analysts aren’t completely sold on whether touchless displays are really next step in computer interfaces. That debate notwithstanding, the technology that enables this approach is impressive. The researchers have developed what amounts to a humidity sensor that reacts to the minute amount of sweat on a finger and converts it to an electrical signal or a change in color of the nanostructured material. The nanostructured material is made up of something called phosphatoantimonic acid, which takes up water molecules and swells considerably in the process. Not only does the material swell, but its electrical conductivity increases with each water molecule it absorbs. ieee.com
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