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Earth

Sea Ice Extent Sinks To Record Lows At Both Poles (sciencedaily.com) 62

According to NASA, Arctic sea ice appears to have reached on March 7 a record low wintertime maximum extent. On the opposite side of the planet, Antartica ice hit its lowest extent ever recorded by satellites (since satellites began measuring sea ice in 1979) on March 3 at the end of summer in the Southern Hemisphere. Science Daily reports: Total polar sea ice covered 6.26 million square miles (16.21 million square kilometers), which is 790,000 square miles (2 million square kilometers) less than the average global minimum extent for 1981-2010 -- the equivalent of having lost a chunk of sea ice larger than Mexico. The ice floating on top of the Arctic Ocean and surrounding seas shrinks in a seasonal cycle from mid-March until mid-September. As the Arctic temperatures drop in the autumn and winter, the ice cover grows again until it reaches its yearly maximum extent, typically in March. The ring of sea ice around the Antarctic continent behaves in a similar manner, with the calendar flipped: it usually reaches its maximum in September and its minimum in February. This winter, a combination of warmer-than-average temperatures, winds unfavorable to ice expansion, and a series of storms halted sea ice growth in the Arctic. This year's maximum extent, reached on March 7 at 5.57 million square miles (14.42 million square kilometers), is 37,000 square miles (97,00 square kilometers) below the previous record low, which occurred in 2015, and 471,000 square miles (1.22 million square kilometers) smaller than the average maximum extent for 1981-2010.
Medicine

Molecule Kills Elderly Cells, Reduces Signs of Aging In Mice (sciencemag.org) 53

An anonymous reader shares an excerpt from a Science Magazine report: Even if you aren't elderly, your body is home to agents of senility -- frail and damaged cells that age us and promote disease. Now, researchers have developed a molecule that selectively destroys these so-called senescent cells. The compound makes old mice act and appear more youthful, providing hope that it may do the same for us. As we get older, senescent cells build up in our tissues, where researchers think they contribute to illnesses such as heart disease, arthritis, and diabetes. In the past, scientists have genetically modified mice to dispatch their senescent cells, allowing the rodents to live longer and reducing plaque buildup in their arteries. Such genetic alterations aren't practical for people, but researchers have reported at least seven compounds, known as senolytics, that kill senescent cells. A clinical trial is testing two of the drugs in patients with kidney disease, and other trials are in the works. However, current senolytic compounds, many of which are cancer drugs, come with downsides. They can kill healthy cells or trigger side effects such as a drop in the number of platelets, the cellular chunks that help our blood clot. Cell biologist Peter de Keizer of Erasmus University Medical Center in Rotterdam, the Netherlands, and colleagues were investigating how senescent cells stay alive when they uncovered a different strategy for attacking them. Senescent cells carry the type of DNA damage that should spur a protective protein, called p53, to put them down. Instead, the researchers found that a different protein, FOXO4, latches onto p53 and prevents it from doing its duty. To counteract this effect, De Keizer and colleagues designed a molecule, known as a peptide, that carries a shortened version of the segment of FOXO4 that attaches to p53. In a petri dish, this peptide prevented FOXO4 and p53 from hooking up, prompting senescent cells to commit suicide. But it spared healthy cells. The researchers then injected the molecule into mutant mice that age rapidly. These rodents live about half as long as normal mice, and when they are only a few months old, their fur starts to fall out, their kidneys begin to falter, and they become sluggish. However, the peptide boosted the density of their fur, reversed the kidney damage, and increased the amount of time they could scurry in a running wheel, the scientists report online today in Cell. When the researchers tested the molecule in normal, elderly mice, they saw a similar picture: In addition to helping their kidneys and fur, the molecule also increased their willingness to explore their surroundings.
Education

'New' Clouds Earn Atlas Recognition (bbc.com) 25

Twelve "new" types of cloud -- including the rare, wave-like asperitas cloud -- have been recognized for the first time by the International Cloud Atlas. From a report: The atlas, which dates back to the 19th Century, is the global reference book for observing and identifying clouds. Last revised in 1987, its new fully-digital edition includes the asperitas after campaigns by citizen scientists. Other new entries include the roll-like volutus, and contrails, clouds formed from the vapour trail of aeroplanes. Since its first publication in 1896, the International Cloud Atlas has become an important reference tool for people working in meteorological services, aviation and shipping. The first edition contained 28 coloured photographs and set out detailed standards for classifying clouds. The last full edition was published in 1975 with a revision in 1987, which quickly became a collector's item. Now, embracing the digital era, the new atlas will initially be available as a web portal, and accessible to the public for the first time.
Earth

Let There Be Light: Germans Switch on 'Largest Artificial Sun' (theguardian.com) 118

German scientists are switching on "the world's largest artificial sun" in the hope that intense light sources can be used to generate climate-friendly fuel. From a report: The Synlight experiment in Julich, about 19 miles west of Cologne, consists 149 souped-up film projector spotlights and produces light about 10,000 times the intensity of natural sunlight on Earth. When all the lamps are swivelled to concentrate light on a single spot, the instrument can generate temperatures of around 3,500C -- around two to three times the temperature of a blast furnace. "If you went in the room when it was switched on, you'd burn directly," said Prof Bernard Hoffschmidt, a research director at the German Aerospace Center, where the experiment is housed in a protective radiation chamber. The aim of the experiment is to come up with the optimal setup for concentrating natural sunlight to power a reaction to produce hydrogen fuel.
Software

Researchers Develop App That Accurately Determines Sperm Quality (scientificamerican.com) 99

New submitter omaha393 writes: A team of researchers at Harvard Medical School have developed a point-of-care microfluidic detector capable of determining sperm quality using the simple device and a standard smartphone. Typical male fertility screens require a team of trained laboratory professionals and a screening process taking days to weeks and incurring high costs. The alternative home sperm measuring kits rely on chemical probes and only give measurements of quantity, not quality.The new method offers an easier, cheaper approach, with processing time taking about 5 seconds with no sample processing or wash steps required. The team found their device meets WHO guidelines with 98% accuracy of sperm quality measurements and is comparable to clinical results. The new device uses 35 microliters of sample to accurately measure both concentration and motility at a manufacturing cost of less than $5 per device. The device must still undergo FDA evaluations before being available to consumers, and the technology has yet to be named. The results of the study were published in the journal Science Translational Medicine. Further reading: NPR, Ars Technica, Scientific American
Mars

SpaceX Disappointed In Lack of NASA Mars Funding; Starts Looking For Landing Sites For Its Own Mars Missions 100

frank249 writes: Elon Musk says that the new NASA authorization legislation "changes almost nothing about what NASA is doing. Existing programs stay in place and there is no added funding for Mars." From a report via Ars Technica: "Musk is absolutely correct on two counts. First, an 'authorization' bill does not provide funding. That comes from appropriations committees. Secondly, while Congress has been interested in building rockets and spacecraft, it is far less interested in investing in the kinds of technology and research that would actually enable a full-fledged Mars exploration program." In other news, SpaceNews reports that "SpaceX has been working with NASA to identify potential landing sites on Mars for both its Red Dragon spacecraft (starting in 2020) and future human missions." From the report: "Paul Wooster of SpaceX said the company, working with scientists at NASA's Jet Propulsion Laboratory and elsewhere, had identified several potential landing sites, including one that looks particularly promising -- Arcadia Planitia. Those landing sites are of particular interest, he said, for SpaceX's long-term vision of establishing a human settlement on Mars, but he said the company wouldn't rule out sending Red Dragon spacecraft elsewhere on the planet to serve other customers. 'We're quite open to making use of this platform to take various payloads to other locations as well,' he said. 'We're really looking to turn this into a steady cadence, where we're sending Dragons to Mars on basically every opportunity.' The Red Dragon spacecraft, he said, could carry about one ton of useful payload to Mars, with options for those payloads to remain in the capsule after landing or be deployed on the surface. 'SpaceX is a transportation company,' he said. 'We transport cargo to the space station, we deliver payloads to orbit, so we're very happy to deliver payloads to Mars.'" Fans of the book/movie "The Martian" would be happy if SpaceX does select Arcadia Planitia for their first landing site as that was the landing site of the Ares 3.
Mars

Mars Rover Spots Clouds Shaped By Gravity Waves (sciencemag.org) 55

sciencehabit writes from a report via Science Magazine: NASA's Curiosity rover has shot more than 500 movies of the clouds above Mars, including the first ground-based view of martian clouds shaped by gravity waves, researchers reported this week at the Lunar and Planetary Science Conference. The shots are the best record made so far of a mysterious recurring belt of equatorial clouds known to influence the martian climate. Understanding these clouds will help inform estimates of ground ice depth and perhaps recurring slope lineae, potential flows of salty water on the surface, says John Moores, a planetary scientist at York University in Toronto, Canada, who led the study with his graduate student, Jake Kloos. "If we wish to understand the water story of Mars's past," Moores says, "we first need to [separate out] contributions from the present-day water cycle." Using Curiosity's navigation camera, Moores and Kloos recorded eight-frame movies of this wispy cloud belt for two martian years. They've used two angles to capture the clouds: one pointed directly up, to see wind direction and speed, and another that keeps the rover's horizon in the frame, allowing a view into the clouds' depth. Given the limited water vapor, solar energy, and atmosphere, the martian clouds lack the variety of shapes seen on Earth. But during one day of cloud gazing -- Curiosity's 1302th martian day, to be precise -- the team got lucky and saw something unusual. That day, when Curiosity looked to the horizon, it saw a sequence of straight, parallel rows of clouds flowing in the same direction: the first ground-based view of a gravity wave cloud. Similar to the waves that follow a pebble tossed into a pond, gravity waves are created when some unknown feature of the martian landscape causes a ripple in the atmosphere that is then seen in clouds. Such waves are common at the edge of the martian ice caps, but thought to be less frequent over its equator.
Power

Japanese Company Develops a Solar Cell With Record-Breaking 26%+ Efficiency (arstechnica.com) 121

An anonymous reader quotes a report from Ars Technica: The silicon-based cells that make up a solar panel have a theoretical efficiency limit of 29 percent, but so far that number has proven elusive. Practical efficiency rates in the low-20-percent range have been considered very good for commercial solar panels. But researchers with Japanese chemical manufacturer Kaneka Corporation have built a solar cell with a photo conversion rate of 26.3 percent, breaking the previous record of 25.6 percent. Although it's just a 2.7 percent increase in efficiency, improvements in commercially viable solar cell technology are increasingly hard-won. Not only that, but the researchers noted in their paper that after they submitted their article to Nature Energy, they were able to further optimize their solar cell to achieve 26.6 percent efficiency. That result has been recognized by the National Renewable Energy Lab (NREL). In the Nature Energy paper, the researchers described building a 180.4 cm2 cell using high-quality thin-film heterojunction (HJ) -- that is, layering silicon within the cell to minimize band gaps where electron states can't exist. Controlling heterojunctions is a known technique among solar cell builders -- Panasonic uses it and will likely incorporate it into cells built for Tesla at the Solar City plant in Buffalo, and Kaneka has its own proprietary heterojunction techniques. For this record-breaking solar cell, the Kaneka researchers also placed low-resistance electrodes toward the rear of the cell, which maximized the number of photons that collected inside the cell from the front. And, as is common on many solar cells, they coated the front of the cell with a layer of amorphous silicon and an anti-reflective layer to protect the cell's components and collect photons more efficiently.
Earth

'Extreme and Unusual' Climate Trends Continue After Record 2016 (bbc.com) 362

From a report on BBC: In the atmosphere, the seas and around the poles, climate change is reaching disturbing new levels across the Earth. That's according to a detailed global analysis from the World Meteorological Organization (WMO). It says that 2016 was not only the warmest year on record, but it saw atmospheric CO2 rise to a new high, while Arctic sea ice recorded a new winter low. The "extreme and unusual" conditions have continued in 2017, it says. Reports earlier this year from major scientific bodies - including the UK's Met Office, Nasa and NOAA -- indicated that 2016 was the warmest year on record. The WMO's State of the Global Climate 2016 report builds on this research with information from 80 national weather services to provide a deeper and more complete picture of the year's climate data.
Science

No, We Probably Don't Live in a Computer Simulation, Says Physicist (gizmodo.com) 405

Science doesn't have all the answers. There are plenty of things it may never prove, like whether there's a God. Or whether we're living in a computer simulation, something proposed by Swedish philosopher Nick Bostrom. From an article on Gizmodo: This kind of thinking made at least one person angry, theoretical physicist and science writer Sabine Hossenfelder from the Frankfurt Institute for Advanced Studies in Germany. Last week, she took to her blog Backreactions to vent. It's not the statement "we're living in a simulation" that upsets Hossenfelder. It's the fact that philosophers are making assertions that, if true, should most certainly manifest themselves in our laws of physics. "I'm not saying it's impossible," Hossenfelder told Gizmodo. "But I want to see some backup for this claim." Backup to prove such a claim would require a lot of work and a lot of math, enough to solve some of the most complex problems in theoretical physics.
Space

A New Definition Would Add 102 Planets To Our Solar System -- Including Pluto (washingtonpost.com) 150

The Grim Reefer quotes a report from The Washington Post: Is Pluto a planet? It's not a question scientists ask in polite company. "It's like religion and politics," said Kirby Runyon, a planetary scientist at Johns Hopkins University. "People get worked up over it. I've gotten worked up over it." For years, astronomers, planetary scientists and other space researchers have fought about what to call the small, icy world at the edge of our solar system. Is it a planet, as scientists believed for nearly seven decades? Or must a planet be something bigger, something more dominant, as was decided by vote at the International Astronomical Union (IAU) in 2006? The issue can bring conversations to a screeching halt, or turn them into shouting matches. "Sometimes," Runyon said, "it's just easier not to bring it up." But Runyon will ignore his own advice this week when he attends the annual Lunar and Planetary Science Conference in Houston. In a giant exhibit hall crowded with his colleagues, he's attempting to reignite the debate about Pluto's status with an audacious new definition for planet -- one that includes not just Pluto, but several of its neighbors, objects in the asteroid belt, and a number of moons. By his count, 102 new planets could be added to our solar system under the new criteria. USA Today reports: "In the mind of the public, the word 'planet' carries a significance lacking in other words used to describe planetary bodies," the proposal states. "In the decade following the supposed 'demotion' of Pluto by the International Astronomical Union, many members of the public, in our experience, assume that alleged 'non-planets' cease to be interesting enough to warrant scientific exploration."
Medicine

Satellite Navigation 'Switches Off' Parts of Brain Used For Navigation, Study Finds (scientificamerican.com) 156

A new study published today in the journal Nature Communications reveals some of the drawbacks of using satellite navigation (SatNav) technology. After scanning the brains of 24 volunteers as they explored a simulation through the streets of London's Soho district, researchers from the University of London found that listening to a satellite navigation's instructions "switches off" activity in parts of the brain used for navigation. Scientific American reports: The researchers found that a brain structure called the hippocampus, which is involved in both memory and spatial navigation, appears to encode two different maps of the environment: One tracks the distance to the final destination as the crow flies and is encoded by the frontal region of the hippocampus, the other tracks the "true path" to the goal and is encoded by its rear region. During the navigation tasks, the hippocampus acts like a flexible guidance system, flipping between these two maps according to changing demands. Activity in the hippocampal rear region acts like a homing signal, increasing as the goal gets closer. Analysis of the brain-scanning data revealed activity in the rear right of the hippocampus increased whenever the participants entered a new street while navigating. It also varied with the number of new path options available. The more alternatives there were, the greater the brain activity. The researchers also found that activity in the front of the hippocampus was associated with a property called centrality, defined by the proximity of each new street to the center of the network. Further, they observed activity in the participants' prefrontal cortices when they were forced to make a detour and had to replan their route -- and this, too, increased in relation to the number of options available. Intriguingly, when participants followed SatNav instructions, however, brain activity in these regions "switched off." Together, the new findings suggest the rear portion of the hippocampus reactivates spatial memories of possible navigation paths, with more available paths evoking more activity, and that the prefrontal cortex may contribute to path-planning by searching though different route options and selecting the best one.
Medicine

Spider Venom Might Protect Us From Deadly Strokes (arstechnica.com) 41

New submitter evolutionary writes: Apparently the Australian funnel-web spider's venom has amazing properties, if you can use it within 4.5 hours. From a report via Ars Technica: "Venom from the Australian funnel-web spider (Hadronyche infensa) contains a chemical that shuts down an ion channel known to malfunction in brain cells after strokes, researchers report Monday in PNAS. In cell experiments, the harmless chemical protected brain cells from a toxic flood of ions unleashed after a stroke strikes. In rats, the venom component markedly protected the rats' brains from extensive damage -- even when it was given hours after a stroke occurred. Researchers have years, if not decades, of work to figure out if their particular venom is safe and effective in humans. And very few potential therapies make the cut. But, this early study gives us reason to be somewhat optimistic: it follows years of research and hypotheses that such venom components and their ion channel-targets could be key to new stroke treatments -- which are desperately needed. The vast majority of strokes involve a blockage that stops or slows the flow of blood into an area of the brain (other strokes can be caused by hemorrhages.) This leaves brain cells without fresh blood and oxygen. To cope, the cells can switch to metabolic pathways that don't rely on oxygen. But this creates acidic conditions, and the pH outside of brain cells starts dropping fast -- a scenario called acidosis. In the acidic, oxygen-starved brain regions, brain cells become damaged and start dying off, causing irreparable damage. The only drug approved by the Food and Drug Administration to treat these types of strokes tries to restore blood flow by breaking up clots. But this drug is only used in about three to four percent of stroke victims because it has to be used within 4.5 hours of the stroke. It also comes with the risk of causing hemorrhages."
Mars

Trump Adds To NASA Budget, Approves Crewed Mission To Mars (nbcnews.com) 299

An anonymous reader quotes a report from NBC News: President Donald Trump signed a law on Tuesday authorizing funding for a crewed NASA mission to Mars. The new bill (S.442) adds a crewed mission to the red planet as a key NASA objective and authorizes the space agency to direct test human space flight programs that will enable more crewed exploration in deep space. The space agency has $19.5 billion in funding for the 2018 fiscal year, which starts this October. Trump had allocated $19.1 billion for NASA in his budget, which is slightly down from the current year, but still an improvement from the past decade, which saw the end of the space shuttle program. The commander in chief signed the bill surrounded by astronauts and his former Republican rivals, Senator Ted Cruz of Texas and Senator Marco Rubio of Florida, who both sponsored the bill. Getting to Mars, though, isn't expected to happen during the Trump presidency. NASA has its sights set on getting to the red planet in the 2030s. In the near term, NASA plans to test its Orion spacecraft and Space Launch System rocket, in addition to visiting an asteroid and redirecting a chunk of it into orbit around the moon. Astronauts could later visit the boulder and use the mission to test some of the tools needed for a Mars mission.
Power

John Goodenough's Colleagues Are Skeptical of His New Battery Technology (qz.com) 248

Earlier this month, a research team led by John Goodenough announced that they had created a new fast charging solid-state battery that can operate in extreme temperatures and store five to ten times as much energy as current standard lithium-ion batteries. The announcement was big enough to have Google's Eric Schmidt tweeting about it. However, there are some skeptics, including other leading battery researchers. "For his invention to work as described, they say, it would probably have to abandon the laws of thermodynamics, which say perpetual motion is not possible," reports Quartz. "The law has been a fundamental of batteries for more than a century and a half." Quartz reports: Goodenough's long career has defined the modern battery industry. Researchers assume that his measurements are exact. But no one outside of Goodenough's own group appears to understand his new concept. The battery community is loath to openly challenge the paper, but some come close. "If anyone but Goodenough published this, I would be, well, it's hard to find a polite word," Daniel Steingart, a professor at Princeton, told Quartz. Goodenough did not respond to emails. But in a statement released by the University of Texas, where he holds an engineering chair, he said, "We believe our discovery solves many of the problems that are inherent in today's batteries. Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven cars to be more widely adopted." In addition, Helena Braga, the paper's lead author, in an exchange of emails, insisted that the team's claims are valid. For almost four decades, Goodenough has dominated the world of advanced batteries. If anyone could finally make the breakthrough that allows for cheap, stored electricity in cars and on the grid, it would figure to be him. Goodenough invented the heart of the battery that is all but certainly powering the device on which you are reading this. It's the lithium-cobalt-oxide cathode, invented in 1980 and introduced for sale by Sony in 1991. Again and again, Goodenough's lab has emerged with dramatic discoveries confirming his genius. It's what is not stated in the paper that has some of the battery community stumped. How is Goodenough's new invention storing any energy at all? The known rules of physics state that, to derive energy, differing material must produce differing eletro-chemical reactions in the two opposing electrodes. That difference produces voltage, allowing energy to be stored. But Goodenough's battery has pure metallic lithium or sodium on both sides. Therefore, the voltage should be zero, with no energy produced, battery researchers told Quartz. Goodenough reports energy densities multiple times that of current lithium-ion batteries. Where does the energy come from, if not the electrode reactions? That goes unexplained in the paper.

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