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
Twin Stars Simplify Distance Measurements
Paula Jofré was roughly 39,000 feet above the Atlantic Ocean when she had an idea. In between bouts of turbulence, she pondered a question her colleagues had posed earlier: What could they learn from nearby stars with identical spectra? Jofré’s revelation answered the question simply: their distances. Stars with identical spectra will have other identical characteristics, like their brightnesses — which is a tell-tale sign of their distances. [...] Cosmic Rulers to the Stars [...] The most accurate “cosmic yardstick” used today doesn’t rely on a star’s intrinsic brightness but rather its parallax — the tiny back-and-forth motion that it makes with respect to background stars as Earth loops around the Sun. The closer the star is to Earth, the more pronounced its shift. So this method can only be applied to stars in our immediate neighborhood, because for very distant stars the shift is too tiny to measure reliably. The Gaia satellite, which launched in December 2013, will be able to measure a star’s parallax 10 times better than before. It will also chart 1 billion stars. But that colossal number is only 1% of the stars in the Milky Way Galaxy. [...] A New Cosmic Ruler: Stellar Twins Jofré’s method looks at stellar twins. Although these stars come from different stellar nurseries (in fact, they might be hundreds of light-years away from each other), their identical spectra imply identical luminosities. Then, if the nearer star’s distance is known via parallax measurements, the inverse-square law makes quick work of determining how much farther it is to the more distant twin. skyandtelescope
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New Antenna Could Give Mars Rovers A Direct Line To Earth
Talking to rovers on the surface of Mars could become much easier, thanks to a new type of antenna that would send messages directly between the robotic explorers and Earth. Currently, robotic rovers on the surface of Mars communicate with Earth by first relaying messages to a satellite orbiting the Red Planet; but the new antenna would cut out the middle-man and allow rovers to communicate directly with scientists back home. The new antenna design would also dramatically increase the available communication time between Red Planet rovers and Earth, according to a statement from the University of California at Los Angeles. [...] The new design combines many small antennas, known as antenna elements, into a larger single antenna, using a unique geometry. The new instrument can transmit and receive signals with greater power than current rover antennas are capable of, the statement said. [...] Known as a circularly polarized half E-shaped patch antenna element, the hardware sends and receives radio communications in a configuration that reduces the effects of atmospheric gas and particles, allowing the communications to travel through the atmosphere with minimal interference. [...] Rovers traveling to Mars would require a larger final antenna, composed of four rows made up of four of the original elements, for a total of 256 antenna elements. The full antenna, which would be just a little bit larger than a standard chessboard, packs more communication power in a tighter space than bulky dish antennas, with the added bonus of being easier to store during flight. space.com
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Biology
Newly Discovered Insect Virus Could Combat Invasive Ants
Like colonial Europeans carrying smallpox to the Americas, the tiny brown Argentine ant may be harboring a dangerous virus that’s killing the world’s already vulnerable honey bees. That’s the conclusion of a new study, which also finds that the ants have their own disease to worry about—one that scientists could target to limit the spread of this invasive species. [...] As its name suggests, the Argentine ant (Linepithema humile) is originally from Argentina. But thanks to the globalization of human society, the invaders have now spread to every continent except Antarctica. They arrived in New Zealand in 1990, for example, probably on a boat or a plane, and have since formed a super colony spanning the nation. [...] To investigate what sort of viruses naturally infect the Argentine ants, Lester and colleagues extracted RNA from two groups of 30 Argentine ants from two separate nesting sites in Wellington, New Zealand. The team then compared sequences of the purified genetic material to a library of known insect RNA viruses, looking for bits that might be similar. The researchers report today in Biology Letters that they’ve discovered a novel virus—which they’ve named Linepithema humile virus 1 (LHUV-1)—in the Argentine ant population. LHUV-1 is highly similar to another RNA insect virus called the cricket paralysis virus, and is suspected to be harmful to the ants. Whether the new virus is directly responsible for the observed population collapses is still unclear, but Lester thinks it’s a promising candidate. [...] If the virus can be used against the ants, it could be a huge boon for honey bee populations around the world. The team’s RNA analysis also showed that the ants carry the deformed wing virus, which has been implicated in the global honey bee decline. And, according to Lester, there’s plenty of chance for the ants to spread the virus to bees, too. “They raid bee hives. That’s a really good opportunity for the disease to be spread directly, he says. “We also know they forage on [the same] plants, so that’s another opportunity for exchange.” Holway is more skeptical though, saying there’s no evidence yet of which way the transmission flows. The ants could just as easily be picking up the virus from the bees during the same raids. sciencemag.org
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Africanized Bees Spreading Through California
A study conducted by biologists at UC San Diego has found that the Africanized honey bee--an aggressive hybrid of the European honey bee--is continuing to expand its range northward since its introduction into Southern California in 1994. [...] "Our study shows that the large majority of bees one encounters in San Diego County are Africanized and that most of the bees you encounter are from feral colonies, not managed hives," said Joshua Kohn, a professor of biology at UC San Diego who headed the study. "The pattern of Africanization we documented in San Diego County and elsewhere in California appears consistent with patterns previously documented in Texas, where Africanized honey bees first appeared in the United States. After the initial wave of hybridization, the remaining bees have a mixture of African and European genes, with the majority of the genome from Africa." Africanized bees are hybrids of a subspecies from southern Africa that were brought to Brazil to improve honey production, but escaped and spread throughout South America and Central America, arriving in Mexico in 1985 and Texas in 1990. Their aggressive behavior and tendency to swarm victims have led them to be dubbed "killer bees." Kohn said that while the southern range of the bees has stabilized in Argentina, the northward expansion is still ongoing. He and his graduate student Yoshiaki Kono sought to determine how far and how fast the northward expansion of Africanized bees was occurring in California by examining the genetic markers of 265 honey bees they collected at 91 sites throughout the state. sciencedaily.com
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Chemistry
Glyphosate To Be Labelled A Carcinogen In California
California’s Environmental Protection Agency (Cal/EPA) intends to list the herbicide glyphosate – the active ingredient in Monsanto’s RoundUp – as a carcinogenic chemical under the Proposition 65, which requires the state to publish a list of chemicals known to cause cancer, birth defects or other reproductive harm. The announcement came on 4 September, following a conclusion by the World Health Organisation’s International Agency for Research on Cancer in March that glyphosate is a probable human carcinogen. Sales of the product are not restricted by the Cal/EPA listing, but adding glysophate to the Prop 65 list would mean that businesses will be required to provide a ‘clear and reasonable’ health warning on Roundup and other glyphosate products. World usage of glyphosate is at an all-time high, with its use increasing more than 20-fold since 1990, according to the Center for Biological Diversity (CBD). The conservation advocacy group says this upsurge is largely due to the widespread adoption of crops, particularly corn and soy, which are genetically engineered to withstand what would otherwise be fatal doses of glyphosate. Recent research also indicates that chronic, low-dose exposure to glyphosate can cause liver and kidney damage, and studies have pointed to glyphosate as a leading cause of the decline in monarch butterflies. rsc.org
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First Metal-Organic Framework Made With Protein
Chemists have engineered a protein so that it self-assembles with zinc ions and an organic small molecule to form the first protein-based metal-organic framework (MOF). Including proteins in MOFs could combine the biocatalytic, electron-transfer, and molecular recognition capabilities of proteins with the separation, storage, and catalysis applications of MOFs. [...] The researchers engineered human ferritin with metal-binding sites, permitting each protein molecule to accommodate eight zinc ions on its surface. When the engineered protein is mixed with zinc and benzenehydroxamic acid, zinc binds to the protein and benzenehydroxamic acid acts as a linker, chelating zinc ions on separate ferritins. This self-assembly process results in a MOF crystal in which each zinc-decorated ferritin is linked to eight neighboring ones. In addition to creating a new type of MOF, the work “introduces a new strategy for the rational design of protein crystals,” [Akif Tezcan at the University of California, San Diego] says. Self-assembling protein networks have been created before, but earlier structures were made from two independent components instead of three and formed random structures instead of crystalline ones. The addition of a third component adds design versatility to the materials, and crystals are more uniform and well-defined than noncrystalline substances. Chemists have made MOFs with amino acids or short peptides, but never before with a functional protein such as ferritin, which acts in the body to store iron. acs.org
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Earth Science
The Long-Term Effects Of The Exxon Valdez Oil Spill
For 25 years, methodical research by scientists has investigated the effects of the Exxon Valdez oil spill in 1989 on Alaskan communities and ecosystems. A new study released today into the effects of the 1989 Exxon Valdez oil spill in Alaska shows that embryonic salmon and herring exposed to very low levels of crude oil can develop hidden heart defects that compromise their later survival, indicating that the spill may have had much greater impacts on spawning fish than previously recognized. The herring population crashed four years after the spill in Prince William Sound and pink salmon stocks also declined, but the link to the oil spill has remained controversial. The new findings published in the online journal Scientific Reports suggest that the delayed effects of the spill may have been important contributors to the declines. "These juvenile fish on the outside look completely normal, but their hearts are not functioning properly and that translates directly into reduced swimming ability and reduced survival," said John Incardona, a research toxicologist at NOAA Fisheries' Northwest Fisheries Science Center in Seattle. "In terms of impacts to shore-spawning fish, the oil spill likely had a much bigger footprint than anyone realized." enn.com
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Just How Much Could The Sea Rise From Burning Fossil Fuels? A Lot.
New York City would be swallowed by the ocean. Tokyo and Shanghai, too, would vanish. Sea levels stand to rise by a staggering 164 feet (50 meters) or more if the world goes for broke on fossil fuels, burning all its attainable resources. That's because the Antarctic Ice Sheet would melt entirely from the warming caused by those emissions, concludes a study published Friday in Science Advances. The researchers say their paper offers the first long-term look at how carbon dioxide emissions from oil, coal, and natural gas would affect the entire ice sheet. "If we don't stop dumping our waste CO2 into the sky, land that is now home to more than billion people will one day be underwater," says study co-author Ken Caldeira, senior scientist at Stanford University's Carnegie Institution for Science. [...] There's a bright side, sort of: The full melt would take about 10,000 years. However, at least 100 feet of the swell, as modeled in the paper from scientists in Germany, California, and the United Kingdom, would occur in this millennium, at a rate of more than an inch per year—a harrowing prospect, given that many coastal areas are already seeing land loss and flooding from much more modest sea level increases. The study highlights the importance of the international aim to prevent global warming beyond 2°C (3.6°F) over pre-industrial levels, a goal that some scientists say is already unrealistic. Meeting that target, the new paper says, would keep Antarctic melting in check, limiting the attendant sea level rise to two meters. Blowing past that threshold, on the other hand, would stoke the disintegration of the entire ice sheet. Its potential to raise sea levels "far exceeds all other possible contributions" from melting elsewhere, including the Greenland Ice Sheet, the researchers say. nationalgeographic.com
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Physics
Kirigami Solar Cells Follow The Sun
The ancient Japanese art of kirigami, or paper cutting, has been used by researchers in the US to improve the efficiency of solar-panel tracking systems. The researchers cut a pattern in thin-film gallium-arsenide solar cells, which causes the cells to tilt when stretched. The system is an improvement on existing solar-tracking equipment, which is bulky, expensive and generally beyond the reach of household solar arrays. The team says that its new design could easily be deployed on individual houses as well as in larger arrays, and, as an added bonus, also improves the optical and mechanical properties of the solar cell. Flat-panelled solar-cell arrays are most effective when sunlight is directly incident on their surface. Solar trackers are used to orient such arrays, along one or two axes, allowing them to follow the Sun as its position in the sky changes during the course of a day and throughout the year.
YouTube Video
physicsworld
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LHCb Observes Two New Baryon Particles
Today the collaboration for the LHCb experiment at CERN’s Large Hadron Collider announced the discovery of two new particles in the baryon family. The particles, known as the Xi_b'- and Xi_b*-, were predicted to exist by the quark model but had never been seen before. A related particle, the Xi_b*0, was found by the CMS experiment at CERN in 2012. The LHCb collaboration submitted a paper reporting the finding to Physical Review Letters. Like the well-known protons that the LHC accelerates, the new particles are baryons made from three quarks bound together by the strong force. The types of quarks are different, though: the new X_ib particles both contain one beauty (b), one strange (s), and one down (d) quark. Thanks to the heavyweight b quarks, they are more than six times as massive as the proton. But the particles are more than just the sum of their parts: their mass also depends on how they are configured. Each of the quarks has an attribute called "spin". In the Xi_b'- state, the spins of the two lighter quarks point in the opposite direction to the b quark, whereas in the Xi_b*- state they are aligned. “Nature was kind and gave us two particles for the price of one," said Matthew Charles of the CNRS's LPNHE laboratory at Paris VI University. "The Xi_b'- is very close in mass to the sum of its decay products: if it had been just a little lighter, we wouldn't have seen it at all using the decay signature that we were looking for.” "This is a very exciting result. Thanks to LHCb's excellent hadron identification, which is unique among the LHC experiments, we were able to separate a very clean and strong signal from the background," said Steven Blusk from Syracuse University in New York. “It demonstrates once again the sensitivity and how precise the LHCb detector is.” cern.ch
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