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
(Unofficially) Naming Pluto
On July 8th we showed you a picture of Pluto’s odd equator, containing two features that NASA scientists at the time had dubbed “the whale” and “the donut.” Here is the same image again, but this time with some more plausible (but still preliminary) names that Mark Showalter (SETI), organizer of the OurPluto campaign to solicit Pluto-feature names from the public, put together for a July 14th science presentation. (Most of these names were captured in a photo taken by Emily Lakdawalla and posted to Twitter.) Instead of “the whale,” it’s Cthulhu that’s lurking at Pluto’s equator, with a Balrog and a gaggle of underworld gods and beings as neighbors. [...] These preliminary names come from the list compiled during the OurPluto naming campaign, but so far the International Astronomical Union (IAU) has not approved them (or any others). The IAU is very precise about how they name planetary features. Similar to how biological beings are divided into kingdoms, classes, and species, so too are solar system features (along with stars and galaxies) grouped and classified, then named according to an overarching theme. For example, craters 60 km or greater on Mars are named after deceased scientists and explorers, as well as writers who wrote about the Martian planet. Smaller Martian craters are named after cities with populations less than 100,000. [...] As such, until those studying Pluto can understand and classify Pluto’s features, the IAU will have to wait to properly group and approve names. However, according to Rita Schulz, chair of the IAU’s Working Group on Planetary System Nomenclature, the first name likely to come down the Pluto-naming pipeline will be the Tombaugh Regio — and it seems fitting to name Pluto’s heart after the world’s discoverer. skyandtelescope.com
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Quick Detour By NASA Mars Rover Checks Ancient Valley
Researchers slightly detoured NASA's Curiosity Mars rover from the mission's planned path in recent days for a closer look at a hillside site where an ancient valley had been carved out and refilled. The rover made observations and measurements there to address questions about how the channel formed and filled. Then it resumed driving up Mount Sharp, where the mission is studying the rock layers. The layers reveal chapters in how environmental conditions and the potential to support microbial life changed in Mars' early history. [...] Curiosity has been exploring on Mars since 2012. It reached the base of Mount Sharp last year after fruitfully investigating outcrops closer to its landing site and then trekking to the mountain. The main mission objective now is to examine successively higher layers of Mount Sharp. Curiosity spent several months examining the lowest levels of the mountain's basal geological unit, the Murray formation, at an outcrop called "Pahrump Hills." Then it set off toward a site called "Logan Pass," where the team anticipates a first chance to place the contact-science instruments at the end of the rover's arm onto a darker geological unit overlying or within the Murray formation.
"In pictures we took on the way from Pahrump Hills toward Logan Pass, some of the geologists on the team noticed a feature that looked like what's called an 'incised valley fill,' which is where a valley has been cut into bedrock and then filled in with other sediment," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. [...] We wanted to investigate what cut into the mudstone bedrock, and what process filled it back in," Vasavada said. "The fill material looks like sand. Was the sand transported by wind or by water? What were the relative times for when the mudstone formed, when the valley was cut into it, when the cut was filled in? "It's exciting to see this on Mars for the first time," he continued. "Features like this on Earth capture evidence of change. What in the environment changed to go from depositing one kind of sediment, to eroding it away in a valley, to then depositing a different kind of sediment? It's a fascinating puzzle that Mars has left for us."
nasa.gov
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Asteroid Mining Company's 1st Satellite Launches From Space Station
A private spaceflight company took one small step for asteroid mining this week with the launch of its first spacecraft to test technology that may one day help tap into the riches of the solar system. The Arkyd 3 Reflight spacecraft, a small satellite built by the space-mining company Planetary Resources, launched from the International Space Station on Thursday (July 16), beginning a 90-day mission to test the avionics, control systems and software needed to make asteroid mining possible. Planetary Resources first tried to launch a version of the satellite into orbit last October, but that spacecraft was lost when the commercial Antares rocket carrying it and supplies for the space station exploded shortly after liftoff. But a new incarnation, Arkyd 3 Reflight, made it up to the station earlier this year and is now set to begin testing the technology that will be needed on mining spacecraft. [...]
"The successful deployment of the A3R is a significant milestone for Planetary Resources as we forge a path toward prospecting resource-rich asteroids," Peter Diamandis, Planetary Resources' other co-founder and co-chairman, said in the statement. "Our team is developing the technology that will enable humanity to create an off-planet economy that will fundamentally change the way we live on Earth."
space.com
Biology
How Neurons Remember
Research findings obtained over the past decades increasingly indicate that stored memories are coded as permanent changes of neuronal communciation and the strength of neuronalinterconnections. The learning process evokes a specific pattern of electrical activity in these cells, which influences the response behavior to incoming signals, the expression of genes and the cellular morphology beyond the learning process itself.
"You might say that these changes define the cellular correlate of the memory engram" says Friedrich Johenning, researcher at the Neuroscience Research Center and one of the study's two co-lead authors. "Our work focuses on identifying physiological mechanisms through which a neuron can implement long-term changes of its response", adds the other co-lead author Anne-Kathrin Theis.
In their study the scientists succeeded in demonstrating that the spine calcium response to action potentials back-propagating into the dendritic tree can undergo long-term enhancement. Spines are small but important dendritic processes that facilitate communication between neurons. Whenever a back-propagating action potential encounters such a spine, the calcium concentration within the spines changes due to the rapid influx of calcium ions from the outside via ion channelson the plasmamembrane. In addition, the intracellular ryanodine receptor gets activated, which triggers the release of calcium stored in the cell. This store release results in a long-term modification of the calcium response elicited by electrical impulses inside the spine. It should be noted that these changes are local in nature and limited to individual spines -- the neighboring processes remain unaffected. biologynews.net
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Ocean Acidification May Cause Dramatic Changes To Phytoplankton
Oceans have absorbed up to 30 percent of human-made carbon dioxide around the world, storing dissolved carbon for hundreds of years. As the uptake of carbon dioxide has increased in the last century, so has the acidity of oceans worldwide. Since pre-industrial times, the pH of the oceans has dropped from an average of 8.2 to 8.1 today. Projections of climate change estimate that by the year 2100, this number will drop further, to around 7.8 — significantly lower than any levels seen in open ocean marine communities today. Now a team of researchers from MIT, the University of Alabama at Birmingham, and elsewhere has found that such increased ocean acidification will dramatically affect global populations of phytoplankton — microorganisms on the ocean surface that make up the base of the marine food chain. [...] The researchers also compared phytoplankton’s response not only to ocean acidification, but also to other projected drivers of climate change, such as warming temperatures and lower nutrient supplies. For instance, the team used a numerical model to see how phytoplankton as a whole will migrate significantly, with most populations shifting toward the poles as the planet warms. Based on global simulations, however, they found the most dramatic effects stemmed from ocean acidification. [...]
“I’ve always been a total believer in climate change, and I try not to be an alarmist, because it’s not good for anyone,” says Dutkiewicz, who is the paper’s lead author. “But I was actually quite shocked by the results. The fact that there are so many different possible changes, that different phytoplankton respond differently, means there might be some quite traumatic changes in the communities over the course of the 21st century. A whole rearrangement of the communities means something to both the food web further up, but also for things like cycling of carbon.”
mit.edu
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Mammoths Killed By Abrupt Climate Change
Using advances in analysing ancient DNA, radiocarbon dating and other geologic records an international team led by researchers from the University of Adelaide and the University of New South Wales (Australia) have revealed that short, rapid warming events, known as interstadials, recorded during the last ice age or Pleistocene (60,000-12,000 years ago) coincided with major extinction events even before the appearance of man. [...]
"This abrupt warming had a profound impact on climate that caused marked shifts in global rainfall and vegetation patterns," said University of Adelaide lead author and Director of the Australian Centre for Ancient DNA, Professor Alan Cooper. "Even without the presence of humans we saw mass extinctions. When you add the modern addition of human pressures and fragmenting of the environment to the rapid changes brought by global warming, it raises serious concerns about the future of our environment."
sciencedaily
Chemistry
EU Bans Endocrine Disruptor From Textile Imports
Campaigners at Greenpeace are celebrating the EU’s decision to ban imports on textiles containing nonylphenol ethoxylates (NPEs), chemicals used as detergents and wetting agents in the manufacture of clothing . The organisation has been lobbying for many years to ban the use of NPEs, which are released into waterways when clothes containing them are washed. There they break down into nonylphenol (NP), which accumulates in the environment and has been shown to have toxic and endocrine-disrupting effects on fish and other wildlife. The EU banned the use of NPEs in textile manufacture several years ago, but the latest decision prevents companies importing NPE-containing textiles that have been manufactured elsewhere. Many high profile clothing brands, such as Nike and Puma, have also announced plans to remove textiles made using NPE from their products. rsc.org
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Self-Powered Human-Interactive Transparent Nanopaper Systems
Abstract: Self-powered human-interactive but invisible electronics have many applications in anti-theft and anti-fake systems for human society. In this work, for the first time, we demonstrate a transparent paper-based, self-powered, and human-interactive flexible system. The system is based on an electrostatic induction mechanism with no extra power system appended. The self-powered, transparent paper device can be used for a transparent paper-based art anti-theft system in museums or for a smart mapping anti-fake system in precious packaging and documents, by virtue of the advantages of adding/removing freely, having no impairment on the appearance of the protected objects, and being easily mass manufactured. This initial study bridges the transparent nanopaper with a self-powered and human-interactive electronic system, paving the way for the development of smart transparent paper electronics. acs.org
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Earth Science
Mangroves Help Protect Against Sea Level Rise
Mangrove forests could play a crucial role in protecting coastal areas from sea level rise caused by climate change, according to new research involving the University of Southampton. A joint study between researchers at the University of Southampton along with colleagues from the Universities of Auckland and Waikato in New Zealand used cutting-edge mathematical simulations to study how mangrove forests respond to elevated sea levels. Taking New Zealand mangrove data as the basis of a new modelling system, the team were able to predict what will happen to different types of estuaries and river deltas when sea levels rise. They found areas without mangroves are likely to widen from erosion and more water will encroach inwards, whereas mangrove regions prevent this effect - which is likely due to soil building up around their mesh-like roots and acting to reduce energy from waves and tidal currents. Coastal estuaries and recesses in coastlines that form bays receive the run-off from erosion on steep catchments, which give them the tendency to fill in over time. As they infill, the movement of the tidal currents over the shallow areas create networks of sandbanks and channels. The sand banks grow upward to keep pace with water level changes, while the channels get deeper to efficiently drain the excess water out to sea. enn.com
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Could Next-Gen Reactors Spark Revival In Nuclear Power?
Leslie Dewan was only in sixth grade, building a mini water wheel in science class, when the last new U.S. nuclear reactor began producing power. Now, at age 30, she’s the millennial face of next-generation nuclear. A slight look-alike to actress Amy Adams, this co-creator of a new molten salt reactor defies the stereotype of the middle-aged male nuclear scientist. Much about the tech-savvy push to reboot nuclear power bucks tradition. Many U.S.-based startups with advanced reactor designs are backed by venture capitalists, not the U.S. government. Their impetus differs, too. Unlike American scientists of the 1950s and 19560s, who were locked in an atom-splitting Cold War race with the Soviet Union, they aim to combat climate change. “I’m an environmentalist. I’m doing this, because I think nuclear power is the best way of producing large amounts of carbon-free electricity,” says Dewan, an MIT nuclear engineer and National Geographic emerging explorer. She says the world needs nuclear—along with solar, wind, hydro, and geothermal—to cut heat-trapping emissions. Not all environmentalists agree. In fact, nuclear power divides their ranks. Its radioactive waste and accidents—including the United States’ Three Mile Island in 1979, Ukraine’s Chernobyl in 1986 and Japan’s Fukushima Daiichi in 2011—have prompted many to argue nuclear is just too dangerous. Japan and Germany are paring back. nationalgeographic.com
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Physics
Tic Toc: Why Pendulums Swing In Harmony
Almost 350 years ago, Dutch inventor and scientist Christiaan Huygens observed that two pendulum clocks hanging from a wall would synchronise their swing over time. What causes the phenomenon has led to much scientific head-scratching over the centuries, but no consensus to date. On Thursday, a study in the Nature journal Scientific Reports proposed a solution: the pendulums transfer energy to one another through sound pulses. A pair of Portuguese scientists hypothesised that these pulses might move from clock to clock, perturbing the swing of the pendulums and eventually causing them to synchronise. They developed a complex mathematical model before conducting experiments with a pair of clocks attached to a rail fixed to a wall. The theoretical predictions and simulation matched, they found. phys.org
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Metal Foams Could Make Promising Radiation Shields
Lightweight composite metal foams are effective at blocking harmful radiation, according to a new study carried out by researchers in the US. Indeed, the foams can efficiently block X-rays, gamma rays and neutron radiation, and could also absorb the energy of high-impact collisions. The research may pave the way to metal foams being used in medical imaging, nuclear safety, space exploration and other shielding applications. With their unusual mechanical and thermal properties, composite metal foams are attracting increasing levels of interest. Afsaneh Rabiei and colleagues at North Carolina State University first began investigating the potential for metal foams to be used in military and transport applications such as for blast protection and as armour, before turning their attention to possible uses in space exploration or nuclear shielding. The team was keen to see if such metal foams could actually block various types of radiation, provide structural support and protect against high-energy impacts. Foamy tests Composite metal foams consist of pre-fabricated metallic hollow spheres that are embedded within a metallic matrix. In the latest work, different varieties of the composite foams were made using three main materials – aluminium–steel, steel–steel and tungsten- and vanadium-enriched "high-Z steel–steel" – and in different sphere sizes of 2, 4 and 5.2 mm in diameter. [...]
"This work means there's an opportunity to use composite metal foams to develop safer systems for transporting nuclear waste, more efficient designs for spacecraft and nuclear structures, and new shielding for use in CT scanners," says Rabiei. In addition, she notes, "[The] foams have the advantage of being non-toxic, which means that they are easier to manufacture and recycle."
physicsworld.com
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