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Stephen Colbert, host of the nightly 'The Colbert Report,' said in a new NASA public service announcement released today that he's always been a huge fan of space.

A controversial proposal would regulate sugar as a toxic substance, and not simply because it’s a calorie-rich enabler of obesity. Some researchers say it’s intrinsically dangerous, not unlike alcohol or tobacco, with unique properties that set off a hormonal cascade ending in higher risks of heart disease, stroke and type 2 diabetes.

It’s not a scientifically certain proposition, though a growing body of research suggests it may very well be true, and the implications are thorny. Even people sympathetic to public health-based regulations may balk at treating pastries as cigarettes, as University of California, San Francisco nutritionists suggested in a Feb. 2 Nature paper.

But to anyone looking to artificial sweeteners as an alternative, as pastel-packaged reassurances that regulators won’t ever need to pry donuts from their cold, dead and pudgy hands, science offers only more uncertainty. Some studies even suggest that fake sugar may cause the same problems as real sugar.

“That’s the $64,000 question,” said Susan Swithers of the Ingestive Behavior Research Center at Purdue University. “There are several epidemiological studies showing increased risk of metabolic syndrome in coincidence with the consumption of diet sodas” — a rich source of sweeteners. “But how they should be interpreted is not really clear right now. Because they’re correlational studies, they don’t tell us what caused what.”

Artificial sweeteners are a fast-growing, multi-billion dollar product, present in thousands of foodstuffs and synthesized by chemists as zealously as drug researchers pursue blockbuster drugs. But as described in a massive 2008 American Journal of Clinical Nutrition Review, the seemingly obvious health benefits expected of low-calorie sugar replacements have failed to materialize.

Even as Americans consumed more sweeteners, waistlines continued to expand. Cause and effect was ambiguous: Sweeteners might lead to weight gain, but maybe people most prone to gaining weight consume the most sweeteners. “This association may be coincidental or causal, and either mode of directionality is plausible,” concluded that study’s authors.

'Artificial sweetener use might be fueling -- rather than fighting -- our escalating obesity epidemic.'Other researchers, however, are more suspicious. When University of Texas Health Science Center epidemiologists conducted a 9-year-long study of 5,158 adult residents of San Antonio, Texas, they found a link between sweeteners and obesity. It persisted even after statistically accounting for gender, ethnicity, diet and beginning-of-diet body mass index. “These findings raise the question whether artificial sweetener use might be fueling — rather than fighting — our escalating obesity epidemic,” they wrote.

Another study of 6,184 adult Americans linked diet soda consumption with higher rates of metabolic syndrome, the umbrella term for a physiological disruption that leads to heart disease, stroke and type 2 diabetes. Once again, the link survived statistical adjustment for demographics, lifestyle and diet.

That’s precisely what’s expected from eating too much sugar, which at least in rats is converted in the liver to fat. That in turn provokes, via as-yet-unidentified mechanisms, resistance to insulin, a hormone used by cells to process glucose, better known as blood sugar. When insulin’s signals are ignored, blood sugar levels rise. Metabolic syndrome follows. But why should this happen when eating fake sugar, not real?

Swithers thinks she knows. In 2008, she and fellow Purdue researcher Terry Davidson fed rats a yogurt supplement sweetened either with glucose, a simple sugar, or zero-calorie saccharin. Apart from the supplement, both groups ate standard rat fare. Those that ate saccharin packed on more fat, gained more weight and consumed extra calories. A follow-up 2009 study reinforced the findings, and found that unusual weight gain persisted even when rats stopped eating sweeteners.

According to Swithers, two mechanisms may be responsible. When the rats’ bodies learned that sweetness didn’t predict an imminent caloric rush, as would naturally be produced by sugar-rich foods, their bodies may have automatically shifted into calorie-saving mode. At the same time, metabolic acceleration that normally occurs when eating high-calorie foods, and helps to process them, may have been slowed.

“All of our work has been in rats. We think similar processes happen in humans, but we haven’t tested them,” Swithers said.

Image: Steve Snodgrass/Flickr

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Photos like this could pass for a Cold War-era Russian propaganda program, or perhaps shots straight from the set of the movie Moonraker — if not for a stray pair of late-20th century sneakers.

Renowned fashion photographer Arthur Elgort, now 72, actually created these images for the December 1999 issue of Russian Vogue. (The magazine is owned by Conde Nast, which also owns Wired.)

In the images, supermodel Natalia Semanova mingles with real-life cosmonauts at Star City, a town northeast of Moscow and home of the Yuri Gagarin Cosmonaut Training Center, where for more than 50 years the Russian Federal Space Agency has trained willing citizens to fly in space. (Recently they’ve also been trained to survive 520 days inside a tin can.)

The photos experienced a recent resurgence in social media circles, so Wired tracked down Elgort to learn more about the timeless photos.

Wired: What led you to merge the worlds of fashion, science and technology for this shoot?

Arthur Elgort: I find it more interesting to put fashion in a setting that is different. Anywhere that the story can be about places that enhance the clothes.

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All images by Arthur Elgort and used with permission from Russian Vogue

Listen to a roundup of some of our favorite stories from this week

Both suns are 2 billion years older than Earth

A new device may help researchers keep an eye on changing stresses along fault zones

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The European Space Agency’s Rosetta spacecraft is heading for a comet.

The ambitious mission — scheduled to enter orbit around Comet 67P/Churyumov-Gerasimenko in January of 2014 and place a tiny lander named Philae on its surface the following November — will no doubt return incredible, never-before-seen pictures. Until then, observers on Earth will have to make do with artists’ renderings like the ones in this video.

In past decades, about a dozen probes have performed comet flybys, sending back photographs of their nuclei. In 2005, NASA’s Deep Impact spacecraft shot a projectile that hit comet Temple 1.

But Rosetta and Philae will be the first mission to enter orbit around a comet and attempt a controlled landing onto its surface. The comet’s gravity is weak and its surface uneven, so Philae will shoot harpoons into the ground to help anchor it.

The probe will get to watch as the icy comet comes to life. Currently just a frozen ball of ice and dust, Churyumov-Gerasimenko will soon feel heat from the solar wind. Eventually, this radiation will melt the comet’s surface, generating a spectacular tail for Rosetta to observe.

The mission is named after the famed Rosetta stone, which allowed archeologists to decipher ancient Egyptian hieroglyphics. Since comets are frozen remnants from our solar system’s formation, researchers hope that the probe will help them understand how the planets came to be.

Image: Astrium - E. Viktor/ESA

Video: NASA

EclipsePhase: @Arcanjo0Sagi We're looking into both of those, but haven't announced anything.

EclipsePhase: @Arcanjo0Sagi We're working on new books and electronic books. Steady-paced, here. ;)

By Mark Brown, Wired UK

Last week, NASA released its 2012 version of the famous “Blue Marble” image. By using a planet-pointing satellite, Suomi NPP, the space agency created an extremely high-resolution photograph of our watery world.

The photo centered on the western hemisphere, highlighting North and Central America. It went viral and got even more hits on Flickr than the iconic “Situation Room” photo, taken at the time of the assassination of Osama bin Laden.

Now, responding to public demand, the agency has created a companion image: this time focusing its lens toward the East and showing Africa, Saudi Arabia and India.

The Suomi NPP satellite hugs the Earth too closely to get this kind of image in one shot. It’s in a polar orbit with an altitude of 824 kilometers, but the perspective of the Eastern hemisphere Blue Marble is from 12,743 kilometers away.

As such, Nasa Goddard oceanographer Norman Kuring used images from six different orbits of the satellite over an eight-hour time period on Jan. 23, then stitched the photos together to achieve the final composite.

Both of the 2012 Blue Marble images are taken by a new instrument aboard Suomi NPP called the Visible Infrared Imaging Radiometer Suite (VIIRS). As for those four vertical lines: That’s the reflection of sunlight off the ocean, or “glint,” that VIIRS captured as it orbited the globe.

Other famous photos of Earth include the original Blue Marble, which was taken on Dec. 7, 1972, by the crew of the Apollo 17 spacecraft. There’s also the equally famous 2002 one, which you might recognize as the default lock screen on the first iPhone. Plus “You Are Here,” an arresting photo of Earth from the surface of Mars, snapped by the Spirit rover in 2004.

Image: NASA/NOAA [high-resolution]

Source: Wired.co.uk

More than 6,300 individuals applied to become a NASA astronaut between Nov. 15, 2011 and Jan. 27, the second highest number of applications ever received by the agency.

NASA's Glenn Research Center (GRC) in Cleveland will host a special event on March 2 to celebrate the 50th anniversary of John Glenn's first orbital flight by an American.

Super-dense objects may help stars form

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Toxic barbs on a cucumber’s skin, nanoscopic flakes of metal and a mouse’s technicolor eyeball (above) are just a few of 2011′s top science visualizations.

A panel of judges picked the best of more than 200 entries from 33 countries for the 2011 International Science and Engineering Visualization Challenge.

“I think because information technology tools and visualization tools have advanced, people have found ever-increasingly clever ways to display difficult scientific concepts,” said competition judge Thomas Wagner, a cryosphere scientist at NASA, in an interview provided by the contest.

Contest judges made their picks based on visual impact, originality and clarity. The winners, which include “people’s choice” awards as well as honorable mentions, were published online Feb. 2 in the journal Science.

The entries weren’t just limited to photographs. Contest categories also included illustrations, informational graphics, videos and even interactive video games.

See the best of these science and engineering visualizations in this gallery.

Images and videos courtesy of AAAS/Science

Above:

Mouse Eyeball Cells

Researchers stained ultra-thin slices of a mouse’s eye to create this first-place photography winner.

The stain was made of three antibodies that bind to three different molecules present in all cells, but in differing concentrations. Assigning red, blue and green to each antibody allowed the creators to depict more than 70 different cell types in the organ.

Image: Bryan William Jones/University of Utah/Moran Eye Center [high-resolution]

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People with brains wired for drug abuse don't necessarily become addicts

Magnetic fields may tame the most extreme pulsars

Warmer seas spur growth in cooler reefs

Researchers create world's thinnest pane of glass—and it resembles an 80-year-old sketch

By Mark Brown, Wired UK

After 20 years of drilling, a team of Russian researchers is close to breaching the prehistoric Lake Vostok, which has been trapped deep beneath Antarctica for the last 14 million years.

Vostok is the largest in a sub-glacial web of more than 200 lakes that are hidden 4 km beneath the ice. Some of the lakes formed when the continent was much warmer and still connected to Australia.

The lakes are rich in oxygen (making them oligotrophic), with levels of the element some 50 times higher than what would be found in your typical freshwater lake. The high gas concentration is thought to be because of the enormous weight and pressure of the continental ice cap.

If life exists in Vostok, it will have to be an extremophile — a life form that has adapted to survive in extreme environments. The organism would have to withstand high pressure, constant cold, low nutrient input, high oxygen concentration and an absence of sunlight.

The conditions in Lake Vostok are thought to be similar to the conditions on Jupiter’s moon Europa and Saturn’s tiny moon Enceladus. In June, NASA probe Cassini found the best evidence yet for a massive saltwater reservoir beneath the icy surface of Enceladus. This all means that finding life in the inhospitable depths of Vostok would strengthen the case for life in the outer solar system.

Back on planet Earth, the team at Vostok are running short on time. Antarctica’s summer will soon end and the researchers need to leave their remote base while they still can. Temperatures will drop as low as -80C, grounding planes and trapping the team.

They missed their chance last year. “Time is short, however. It’s possible that the drillers won’t be able to reach the water before the end of the current Antarctic summer, and they’ll need to wait another year before the process can continue,” we wrote in January 2011. The drill halted in February.

Meanwhile, Russian engineers are planning to venture into the lake itself, with swimming robots. In the Antarctic summer of 2012 to 2013, they plan to send a robot into the lake to collect water samples and sediments from the bottom. An environmental assessment of the plan will be submitted at the Antarctic Treaty’s consultative meeting in May 2012.

Image: Wikipedia/NASA

Source: Wired.co.uk

A view across the Santorini caldera. The newest eruptions in the caldera can be seen on the right on Nea Kameni.

This appears to be a week of media interest in new journal articles. Earlier, I discussed a study that claimed that volcanoes were the cause of the onset of the Little Ice Age. Now, we have a study in Nature that discusses the magmatic events that lead up to the Minoan eruption at Santorini – a fairly timely topic considering the rumblings there – that has gotten the media’s attention.

Now, I’m not going to pick apart this paper by Timothy Druitt and others as such – the study, called “Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano“, is actually quite solid. The long-and-short of the study is that they examined plagioclase feldspar crystals looking at the zoning of different elements in these crystals (see below).

There are two main pieces to the study. First, if a crystal grows in a certain magma, it will suck in certain amounts of different elements – some are major constituents of the minerals. In plagiolclase feldspar, we can define the “An” of a crystal by looking at proportions of Ca and Na in the crystal (high “An” means high Ca – closer to the perfect feldspar endmember anorthosite). The “An” can then tell us if a crystal came from one type of magma or another (see figure below). If there are low abundance elements in the mineral, like strontium, magnesium and titanium in plagioclase feldspar, then the amount of the element is controlled by the partitioning of the element between the liquid magma (melt) and the crystal. This is what geologists call the “partition coefficient” – or how likely is an element to want to be in the crystal or melt. The partition coefficient will change depending on the overall composition, pressure and temperature of the magma and crystal, so crystals in different magmas will suck up different amounts of these elements. This gives them distinctive compositions depending on the magma in which they grew – a “compositional signature” so to speak. (Note: I looked that is in zircon from the Okataina Caldera in my Earth and Planetary Science Letters study from last year).

Part of Figure 1 from Druitt et al. (2012) that shows the zoning of plagioclase feldspar from the Minoan eruption of Santorini.

The second piece is diffusion. Elements in crystals will diffuse back into the melt (or vice versa) if there is a large compositional gradient between the crystal and the melt. So, throw a crystal of one composition into a new magma of another, the elements will begin to exchange over time starting at the rim of the crystal. So, assuming specific thermal parameters and compositional gradients, you can use diffusion as a clock – how long has the foreign crystal been exposed to this new magma based on how much diffusion of certain elements has occurred. Now, different elements have different abilities to diffused based on their size and charge, so you need to choose wisely.

The Druitt et al. (2012) study used these two petrologic characteristics of minerals and melt to determine two main conclusions: (1) the magma erupted from Santorini during the Minoan eruption in ~1600 BC was a mixed magma and (2) the intrusion that “got the ball rolling” towards the Minoan eruption and the subsequent mixing happened geologically quickly – in the the timescales of a century to a few months. Now, there is a big caveat not mentioned in the study to this second point. One quandary we have in petrology is that when we look at timescales of processes inside magmatic systems, diffusion profiles like the kind used in this study imply events occur much faster than if you try to date mixed crystals using radiometric elements (such as Ra, Th and U). This disconnect has not been resolved, so I would say that the timescales suggested by Druitt et al. (2012) are minimum timescales for the intrusion and mixing, not maximum. This will be important later on.

You might have noticed a lot of the media coverage about this study is claiming things like “supervolcanoes offer 100 year early warning” and “they may be predicted”. That is never said in the study. The authors do discuss some of the ways that this recharge/mixing might be manifested once the events have begun – interestingly not as “bulging” but rather “sagging” of the bottom of the magmatic system as the magma fills in, so uplift at Santorini might have been minimal. They actually predict that sinking of the land surface might be more likely rather than the classic St. Helens-1980-style bulge.

However, what I see as the biggest problem in this “early warning” claim is that it might still not be easily detectable – what if their timescale is off by even a factor of 2, so it takes 2 centuries to lead to an eruption? Human monitoring of an event 200 years in the making might be very problematic. Secondly, this intrusion isn’t a big event at 100 years than than over, it is growth and mixing over that century with a rapid culmination only months before the eruption according to Druitt et al. (2012). Whether or not this is detectable by current monitoring methods is unclear as well. The authors are right about one thing: “Long-term monitoring of large, dormant caldera systems, even in remote areas of the world, is essential if late-stage growth spurts of shallow magma reservoirs are to be detected well in advance of caldera-forming eruptions.” However, as usual, the many in the media has boiled down their research into meaningless copy that both misses the point of the research but also recklessly mischaracterizes the ramifications.

Image 1: Santorini caldera. Image by Navin75/Flickr.
Image 2: Figure 1 from Druitt et al., (2012)