A device to mix liquids using ultrasonics is the first and most difficult component in a miniaturized system
The post On-Chip Processor: First Step in Point-of-Care Asthma &Tuberculosis Diagnostics has been published on Technology Org.
A team of astronomers, including half a dozen from the Space Telescope Science Institute (STScI) in Baltimore, Maryland, have used the Gemini Observatory's new Gemini Planet Imager to find the most solar system-like planet ever directly imaged around another star. The planet, known as 51 Eridani b, is about two times the mass of Jupiter and orbits its host star at about 13 times the Earth-sun distance (equivalent to being between Saturn and Uranus in our solar system). The planet is located about 100 light-years away from Earth. The Gemini data provide scientists with the strongest-ever spectroscopic detection of methane in the atmosphere of an extrasolar planet, adding to its similarities to giant planets in our solar system. "This planet looks like a younger, slightly bigger version of Jupiter," said Dr. Laurent Pueyo of STScI, one of the astronomers who carefully measured the planet's light against the background glare of starlight. "That we can see so clearly the presence of methane for a planet a million times fainter than its star, even through the atmosphere, bodes very well for the future characterization of even fainter planets from space using the James Webb Space Telescope and the Wide-Field Infrared Survey Telescope."
What happens when you find something in the wrong place at the wrong time? That's a question astronomers have been trying to answer after finding several exploding stars outside the cozy confines of galaxies, where most stars reside. These wayward supernovae also have puzzled astronomers because they exploded billions of years before their predicted detonations. Astronomers using archived observations from several telescopes, including the Hubble Space Telescope, have developed a theory for where these doomed stars come from and how they arrived at their current homes.
ESA’s Rosetta today witnessed Comet 67P/Churyumov–Gerasimenko making its closest approach to the Sun. The exact moment of perihelion occurred at 02:03 GMT this morning when the comet came within 186 million km of the Sun.
Why are the oceans in trouble?
They can no longer absorb the damage inflicted by the 7 billion people on Earth. Over many decades, the human race has overfished key species to near extinction, and polluted them with carbon dioxide emissions, toxic chemicals, garbage, and discarded plastics. A groundbreaking new study, recently published in Science, warned that our oceans are being irreparably damaged by human activity and could be on "the precipice of a major extinction event." Coral reefs, home to a quarter of the ocean's fish, have declined by 40 percent worldwide. Stocks of swordfish, yellowfin tuna, and other large fish that people avidly eat are down by 90 percent. Marine scientists say that if mankind does not dramatically change how it treats the oceans and their inhabitants, many marine species will become extinct — with catastrophic consequences for the food chain. "If by the end of the century we're not off the business-as-usual curve," says Stanford University marine ecologist Stephen Palumbi, one of the report's authors, "there's not much hope for normal ecosystems in the ocean."
How does global warming affect fish?
As the oceans heat up, many species are migrating to cooler waters to survive. Some inevitably will fail in these new habitats. Warmer temperatures also make coral reefs more vulnerable to "bleaching," a chemical process that drains the organisms of their brilliant colors and leads to their death. Other problems are caused directly by the burning of fossil fuels. With oceans absorbing a quarter of the world's CO2 emissions, they have become 30 percent more acidic, causing inhibited shell growth in coral and crustaceans and reproductive disorders in fish. Power plant emissions — especially from burning coal — put tons of highly toxic mercury in the air, which settles into the ocean. The mercury is taken up by sea creatures and concentrated in predatory species. A recent study found that mercury levels in Pacific yellowfin tuna have been rising at a rate of 3.8 percent a year since 1998. "If it keeps going like that," says co-author Carl Lamborg, eventually almost "every kind of fish is going to be potentially hazardous."
What about plastic?
Our oceans contain an estimated 5.25 trillion pieces of plastic — most of them less than 5 millimeters wide — weighing a total of 269,000 tons. A lot of this detritus, which mostly comes from plastic bottles and discarded commercial fishing gear, has collected in vast systems of rotating ocean currents, known as gyres. The largest such collection, the "Great Pacific Garbage Patch," covers an area twice the size of Texas. The mostly tiny pieces of plastic in this and other patches contain many potentially hazardous chemicals, and are being eaten by fish and birds that mistake them for plankton or small fish. As smaller animals are eaten in turn by predatory fish, the plastic becomes more concentrated and winds up in people who eat seafood.
Can't we remove all the plastic?
No chance. The National Oceanic and Atmospheric Administration estimates that to clean less than 1 percent of the North Pacific it would take 68 ships, working 10-hour days, a whole year. A skimming operation of that scope would also suck up tons of marine creatures. And with global plastic production doubling every 10 years, "there's no way to keep up," says Chris Wilcox of Australia's national science agency. "It would be as if you were vacuuming your living room, and I'm standing at the doorway with a bag of dust and a fan."
How big a problem is overfishing?
Since fishing became industrialized just over a century ago, most commercial species have been reduced by more than 75 percent — and some by 99 percent. As stocks dwindle, fishing fleets are increasingly resorting to "bottom trawling," a hugely destructive technique that involves dragging a large net up to 60 meters wide along the seabed, scooping up everything in its path. Most countries now have fishing quotas, but they're hard to enforce: An estimated 1 in 5 fish sold in a shop or served in a restaurant has been caught illegally.
Why aren't we doing more?
Like global warming, the plight of our oceans is an issue that affects every country in the world. But with each government beholden to its own voters — and its own fishing, plastic, and energy lobbies — it's almost impossible to achieve any consensus. Ecologists insist it's not too late to solve the problems affecting our oceans. Some schemes, such as the introduction of "safe zones" where fish can naturally replenish, have worked on a small scale and could be expanded. The authors of the Science study say it's possible to reverse the current crisis, but political will is required. "The next several decades," they say, "will be those in which we choose the fate of the future of marine wildlife."
The dangers of a fishy diet
For decades, doctors and health officials have encouraged people to eat as much seafood as possible because of fish's high levels of omega-3 fatty acids, which are good for heart and brain health. But in recent years that recommendation has been tempered, as emissions from factories and power plants have pushed mercury concentrations in oceans and fish up to potentially dangerous levels. Mercury is highly toxic and can cause neurological damage and accumulate in organs; in children and fetuses, it can lead to long-term cognitive disorders. Last year, the FDA updated its advice on fish to say that pregnant women and children should avoid eating tilefish, shark, swordfish, and king mackerel, and limit their consumption of white tuna — all of which contain particularly high levels of mercury because they're at the top of the food chain. Consumer Reports recently criticized the FDA guidelines on fish consumption as inadequate, saying that anyone who eats 24 ounces or more of fish per week — or about six servings — "should steer clear of high-mercury choices," and warning people not to eat canned tuna or sushi made from tuna.
One of the most focused endeavors of the broader fight against climate change is the movement to demand divestment from fossil fuel companies. Specifically focused on institutional investors, divestment activists have been pressuring pension funds, university endowments, and others with significant holdings in the oil and gas sector to sell those shares (or bonds). This is a multi-pronged effort to raise awareness about how these industries fuel climate change, to divert that capital to low- and zero-carbon resources, and to deter future investment in oil and gas exploration.
As part of that campaign, February 13 and 14 have been designated Global Divestment Day(s), with hundreds of events organized by activist groups. The Norwegian sovereign wealth fund — the largest in the world, built from the country's oil and gas wealth — has announced it would sell holdings in coal and mining companies that, in its estimation, represent an unacceptably high degree of climate-related investment risk. The fossil fuel companies under target are pushing back, with ad campaigns focused on the important role their products play in the global economy.
With these events as a backdrop, a new report from the American Security Project (ASP), a Washington, D.C.-based think tank, casts a critical eye on the divestment movement. The report offers a sensible reminder of what fossil fuel divestment can and cannot do.
While divestment aims at supply-side solutions (trying to starve fossil fuel companies of the capital to fund new exploration and exploitation of reserves), it is beyond the scope of the divestment movement to address the demand side of the equation. Unlike the divestment in Big Tobacco (from which the current movement draws inspiration), coal, oil, and natural gas are not discretionary goods; they are critical to the global economy. Oil companies are not lying when they say people will still need to buy oil over the next 15 to 20 years. Replacements may be available on the horizon (paging Elon Musk), but supplying them at scale remains a challenge.
The financial impact of divestment also tends to be overstated. The ASP report and similar efforts, such as the Stranded Assets Programme at Oxford University, have demonstrated that complete divestment of university endowments from these holdings would, in the long run, have a negligible financial impact on the bottom lines of fossil fuel companies. Money would still flow into company coffers.
What's more, the universities and other organizations that divest could reasonably be accused of violating their fiduciary duty by forgoing money-making investments. That calculation will likely change as renewable-energy investments grow, especially with the proliferation of green bonds, but that market is still far from making steady gains year over year.
While the ASP report puts fossil fuel divestment in its proper place, it leaves open the question of whether the movement can be taken in a direction that is more useful to goals that both activists and analysts share.
Take the example of the Norwegian divestment. Its decision was not to divest from all fossil fuels. Instead, it is taking a measured approach that tries to identify the riskiest assets — and sell only those. Call it "divestment lite" — taking the well-intentioned motives behind divestment and deploying it in a much more targeted and tailored way. It will keep some assets that may be valuable in the intermediate term, but still send a signal to the market and public at-large that changes need to be made.
The ASP report rightfully points out one of the benefits of holding stocks in the first place: shareholder activism. To better leverage their activist network, fossil fuel divesters should follow the Norwegian model, focusing on the low-hanging fruit of coal, tar sands, and oil companies that are inadequately preparing their own businesses for future climate risk. Conversely, they should test the sincerity of companies such as Shell, and explore how to best work with them when their CEO says the oil sector needs to be more constructive in the debates over climate change solutions. Shell has been responsive to shareholder accountability efforts in the past, according to Reuters.
To the extent that the fight against climate change demands changes in a wide variety of consumer behaviors, fossil fuel divestment will have a role to play, even if its most vehement supporters may exaggerate its impact in order to rally support. Identifying better strategies for divestment campaigns will be a crucial factor in ensuring their effectiveness.
Have you watched the Perseid meteor shower? Though the annual shower's predicted peak was last night, meteor activity should continue tonight (August 13/14), best enjoyed by just looking up in clear, dark skies after midnight. Of course, this year's Perseid shower has the advantage of being active near the August 14 New Moon. Since the nearly New Moon doesn't rise before the morning twilight many fainter meteors are easier to spot until then, with no interference from bright moonlight. The Perseid meteor shower last occurred near a New Moon in 2013. That's when the exposures used to construct this image were made, under dark, moonless skies from Hvar Island off the coast of Croatia. The widefield composite includes 67 meteors streaming from the heroic constellation Perseus, the shower's radiant, captured during 2013 August 8-14 against a background of faint zodiacal light and the Milky Way. The next moonless Perseid meteor shower will be in August 2018.For consumers searching for just the right sunblock this summer, the options can be overwhelming. But scientists are
The post An all-natural sunscreen derived from algae has been published on Technology Org.
