Science News
Scientists Put Backpacks on Dragonflies to Track Their Brains in Flight
By Greg Miller
The brain of a dragonfly has to do some serious calculations — and fast — if it hopes to nab a mosquito or midge in midair. It has to predict the trajectory of its prey, plot a course to intersect it, then make adjustments on the fly to counteract any evasive maneuvers. Neuroscientist Anthony Leonardo created the tiny dragonfly backpack above to study how circuits of neurons do these computations.
The backpack weighs 40 milligrams, about as much as a couple grains of sand, equal to just 10 percent of the dragonfly’s weight. Electrodes inserted into the dragonfly’s body and brain record the electrical activity of neurons, and a custom-made chip amplifies the signals and transmits them wirelessly to a nearby computer.
One of the trickiest design challenges was how to power the chip without adding so much mass that the insects couldn’t get off the ground, says Leonardo, who’s based at Howard Hughes Medical Institute’s Janelia Farm Research Campus in Ashburn, Virginia.
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700,000-Year-Old Horse Genome Shatters Record for Sequencing of Ancient DNA
By Joe Hanson
By piecing together the genetic information locked inside a frozen, fossilized bone, scientists have deciphered the complete genome of an extinct prehistoric horse that roamed the Yukon more than 700,000 years ago. The work rewrites the evolutionary history of the horse and smashes the previous record for the oldest complete genome ever sequenced. In doing so, it redefines how far back in time scientists can travel using DNA sequences as their guide.
Every time a cowboy throws a leg over the saddle and gallops off on his horse, he’s riding on top of 4 million years of evolutionary history. But this history is mostly a mystery. We know surprisingly little about how natural selection and thousands of years of selective breeding by humans have shaped these animals on the genetic scale.
Horses were once considered a textbook example for the smooth transition of one species into another, a perfect illustration of Darwin’s theories. Ancient equine species — dog-sized animals with five toes – gradually evolved into towering, hooved thoroughbreds. Or so the story went. But with every fossil that was unearthed, a more tangled picture emerged.
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Technology News
'Corkscrew' Light Could Turbocharge Internet
Different-shaped beams could be used to increase fiber-optic capacity, thereby easing online congestion
By Maggie McKee and Nature magazine
Twisty beams of light could boost the traffic-carrying capacity of the Internet, effectively adding new levels to the information superhighway, suggests research published today in Science.
Internet traffic is growing exponentially and researchers have sought ways to squeeze ever more information into the fiber-optic cables that carry it. One successful method used over the last 20 years essentially added more traffic lanes, using different colors, or wavelengths, for different signals. But to compensate for the added lanes, each one had to be made narrower. So, just as in a real highway, the spacing could get only so tight before the streams of data began to jumble together.
In the last few years, different groups of researchers have tried to encode information in the shape of light beams to ease congestion, using a property of light called orbital angular momentum. Currently, a straight beam of light is used to transmit Internet signals, but certain filters can twist it so that it corkscrews around with varying degrees of curliness as it travels.
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Twitter Sees a Surge in Government Information Requests
CEO Dick Costolo says companies should report when governments ask them for user data
By Larry Greenemeier
Twitter sees itself as the digital incarnation of the town square, eliminating time and distance as barriers to unfiltered communication among citizens. In this role as the world’s unofficial open idea exchange (in 140 characters or less, of course), the company is finding that governments, law enforcement agencies and even its own Twitterverse are increasingly holding it accountable for how people use its microblogging service.
The social network appears to be taking this newfound responsibility seriously. During a Webcast conversation on Wednesday with Brookings Institution Senior Fellow Jonathan Rauch, Twitter CEO Dick Costolo discussed how his company responds to this growing scrutiny. He also talked about Twitter’s attempts to help users filter the fire hose of information they face each day as well as the pros and cons of pseudonymous tweeters.
Although he declined to comment specifically on the U.S. National Security Agency’s PRISM digital surveillance program, Costolo articulated Twitter’s stance on cooperating with government and law enforcement requests. “When we receive a valid, specific request in the countries [where] we operate, we will honor it,” he said. “Those that are not legal and valid, we will push back on.” Twitter is conspicuously absent from the list of tech companies—including Apple, Facebook, Google, Microsoft and Yahoo—accused of complying with the NSA’s requests for user data.
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Environmental News
Large Dead Zone Forming in the Gulf
Texas A&M University
June 27, 2013 — Ocean experts had predicted a large "dead zone" area in the Gulf of Mexico this year, and according to the results from a Texas A&M University researcher just back from studying the region, those predictions appear to be right on target.
Steve DiMarco, professor of oceanography and one of the world's leading experts on the dead zone, says he and a Texas A&M team surveyed areas off the Texas-Louisiana coast last week and found large areas of oxygen-depleted water -- an area covering roughly 3,100 square miles, or about the size of Delaware and Rhode Island combined.
"We found hypoxia (oxygen-depleted water) just about everywhere we looked," DiMarco reports.
"The most intense area is where you would expect it -- off the Louisiana coast south of Atchafalaya Bay and Grande Isle, La. But we also found significant amounts off High Island and near Galveston. The farther south we went, the less we found hypoxia in the water column, but we still found plenty of depleted oxygen waters up to just west of Freeport.
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Location May Stymie Wind and Solar Power Benefits
The health and climate gains made by clean energy are often lowest in the windiest and sunniest places
By Quirin Schiermeier and Nature magazine
Wind farms and solar installations are often located in places where they will have the least impact on climate and health, a report finds.
These renewable energies emit less carbon dioxide and air pollution than burning fossil fuels for electricity. But the windiest and sunniest places in the United States — such as the southwestern plains and deserts — are not always the most socially and environmentally beneficial sites for wind turbines and solar panels. The benefits, according to a study published today in Proceedings of the National Academy of Sciences, vary depending on what energy sources are being replaced.
New wind and solar installations displace the most carbon dioxide and air pollutants where they replace the coal-fired plants found predominantly in eastern and Midwestern states such as Indiana and Pennsylvania. The benefits are much smaller in California and the US southwest, where cleaner gas-fired plants are more common.
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Medical News
New Maps Depict Impact of HIV in America
Emory Health Sciences
June 27, 2013 — Today, on National HIV Testing Day, the Rollins School of Public Health at Emory University launched its annual update of AIDSVu, including new interactive online maps that show the latest HIV prevalence data for 20 U.S. cities by ZIP code or census tract. AIDSVu also includes new city snapshots displaying HIV prevalence alongside various social determinants of health -- such as poverty, lack of health insurance and educational attainment.
AIDSVu -- the most detailed publicly available view of HIV prevalence in the United States -- is a compilation of interactive online maps that display HIV prevalence data at the national, state and local levels and by different demographics, including age, race and sex. The maps pinpoint areas of the country where the rates of people living with an HIV diagnosis are the highest. These areas include urban centers in the Northeast and the South, and visualize where the needs for prevention, testing, and treatment services are the most urgent.
"Our National HIV/AIDS Strategy calls for reducing new HIV infections by intensifying our efforts in HIV prevention where the epidemic is most concentrated. AIDSVu provides a roadmap to identifying those high-prevalence areas of the HIV epidemic and showing where the local testing resources are located," says Patrick S. Sullivan, PhD, DVM, professor of epidemiology at Emory University's Rollins School of Public Health, and the principal researcher for AIDSVu. "The addition of new city data means that AIDSVu now displays data from 20 U.S. cities. This expanded city information is critical because most HIV diagnoses in the United States occur in cities."
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Gut Microbes Spur Liver Cancer in Obese Mice
The intestinal bacteria of obese mice brew up carcinogens that trigger liver cancer
By Beth Mole and Nature magazine
The gut bacteria of obese mice unleash high levels of an acid that promotes liver cancer, reveals one of the first studies to uncover a mechanism for the link between obesity and cancer. The research is published today in Nature.
“Obesity in general has many different types of cancer associated with it,” says Eiji Hara, a cancer biologist at the Japanese Foundation for Cancer Research in Tokyo and one of the study authors. But in the case of liver cancer, he says, “I never expected the microbiome was linked.”
Hara and his colleagues initially set out to study how dying cells influence obesity-linked cancers. Cells that are irreparably damaged or pre-cancerous can become senescent — meaning that they stop dividing for overall health of the organism. But before senescent cells die, they can spew out chemicals that may cause inflammation and promote cancer development.
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Space News
Do 3 Habitable Super-Earths Really Orbit a Nearby Star?
News of possible multiple habitable worlds around the red dwarf star Gliese 667C may be exciting, but researchers caution that certainty about these exoplanets remains elusive
By Lee Billings
From its position 22 light-years away in the constellation of Scorpius, the red M dwarf star Gliese 667 C doesn’t look like much. Its dim light is lost to the naked eye, washed out by two brighter companion stars. Yet this tiny, exceedingly average star could play a crucial role in establishing that small, potentially Earth-like planets are common throughout our galaxy. Researchers have announced that seven planets orbit that star—and, if their mathematical analyses are correct, three of them could be habitable.
Previous surveys of Gliese 667 C had turned up two planets, including a potentially rocky "super-Earth" orbiting in the star's habitable zone, the region in which a planet might possess liquid water on its surface. Dubbed Gliese 667 C c, this world could be a "Goldilocks" planet like Earth, with a "just right" temperature neither too hot nor too cold for life as we know it. Now, after years of hints that more planets lurk in the data, an international team of astronomers led by Guillem Anglada-Escudé of the University of Göttingen in Germany and Mikko Tuomi of the University of Hertfordshire in England have announced their discovery of between three and five additional worlds around the star. Two of these additional bodies could be super-Earths orbiting in the habitable zone, raising the possibility that the star harbors three Goldilocks worlds. The journal Astronomy & Astrophysics published their study (pdf) online June 26.
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NASA telescope to probe long-standing solar mystery
By Irene Klotz
(Reuters) - A small NASA telescope was poised for launch on Thursday on a mission to determine how the sun heats its atmosphere to millions of degrees, sending off rivers of particles that define the boundaries of the solar system.
The study is far from academic. Solar activity directly impacts Earth's climate and the space environment beyond the planet's atmosphere. Solar storms can knock out power grids, disrupt radio signals and interfere with communications, navigation and other satellites in orbit.
"We live in a very complex society and the sun has a role to play in it," said physicist Alan Title, with Lockheed Martin Space Systems Advanced Technology Center in Palo Alto, California, which designed and built the telescope.
Scientists have been trying to unravel the mechanisms that drive the sun for decades but one fundamental mystery endures: How it manages to release energy from its relatively cool, 10,000 degree Fahrenheit (5,500 degree Celsius) surface into an atmosphere that can reach up to 5 million degrees Fahrenheit (2.8 million Celsius).
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Odd News
Could Superman Punch Someone Into Space?
By Rhett Allain
Superman is so strong, he can do anything, right? Could he punch someone so hard that they ended up in space? Let’s do this.
How High Is Space?
When I say space, you might say “outer space.” But how high is that? The Earth’s atmosphere doesn’t just stop at some height. No, instead the density of air gets lower and lower until you can’t even really detect it. But for this problem, we have to pick a height. I am going to pick 420 km above the surface of the Earth as “space.” Why? Why not. That is about the height of the International Space Station’s orbit, so I think it is a good choice.
How Fast Would the Person Have to Go?
I am talking about after the punch from Superman. Let’s just look at a person moving up at some initial speed v0. If this were a problem in an introductory physics course, I would hope you would think of the work-energy principle.
Let’s say that Superman is punching a clone of himself (called Superman-b) – just as an example. If I take Superman-b and the Earth as my system, then after the punch from Superman there is no external work done on the system. There will be two types of change in energy – kinetic and gravitational potential.
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