Thursday 21 October 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Gluttonous Male Mice Give Diabetes to Daughters

Posted: 20 Oct 2010 02:37 PM PDT

A prospective dad's diet may affect the health of his future children, suggests a study of cross-generational nutritional impacts in mice.

Males were fed a high-fat diet, becoming obese and diabetic, then mated with lean, healthy females. At six weeks of age, or the mouse equivalent of puberty, their daughters became glucose-intolerant, a major step toward diabetes.

That overweight moms are more likely to have overweight babies is known, but the phenomenon hadn't before been demonstrated in males of any species.

"It is difficult to comment on how relevant our finding might be for the current diabetes epidemic, but our data suggest that a father's diet, or the fact that he is obese or diabetic, may influence his offspring's risk of disease," said neuropharmacologist Margaret Morris of Australia's University of New South Wales.

It's still too soon to extrapolate to humans the rodent results of Morris and her colleagues, which were published October 20 in Nature. But the results fit an emerging understanding of the role of epigenetics, or the chemical code that turns genes on and off, allowing on-the-fly adaptation to changing environmental conditions.

 

Epigenetic changes take place during an individual's lifetime, but they can be passed down to children and even grandchildren. That was famously described in 1998, in a long-term study of Dutch children born during the World War II famine, and epigenetic research has expanded rapidly in the last decade.

Also expanding is America's waistline, with type 2 diabetes — the kind triggered by a poor diet and lack of activity — reaching epidemic levels.

"The dramatic increase in human metabolic disorders such as obesity and diabetes warrants considering the influence of environmental factors on the germ line," wrote Michael Skinner, a Washington State University reproductive biologist, in a commentary accompanying the findings.

A family history of diabetes is a reliable indicator of increased disease risk. This is usually interpreted purely in terms of genetic mutations, rather than epigenetic changes.

In Morris' study, however, it all fit together. When she compared gene-expression patterns in the sperm of diabetic male mice to healthy males, she found tweaks in hundreds of genes linked to activity in the pancreas, which produces the blood-sugar-regulating hormone insulin.

The males' high-fat diet had caused pervasive cellular changes, which were then passed to their daughters. Most disturbingly, the daughters developed metabolic malfunction even when they were fed a healthy diet.

According to Morris, as-yet-unpublished research suggests that sons were similarly affected.

Morris next plans to study how the daughters' inherited metabolic malfunction progresses with age, and whether it's passed to their offspring as well.

The disorder "may worsen with time," she said.

Image: Flickr, Ernest Figueras.

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Citations: "Chronic high-fat diet in fathers programs b-cell dysfunction in female rat offspring." By Sheau-Fang Ng, Ruby C. Y. Lin, D. Ross Laybutt, Romain Barres, Julie A. Owens & Margaret J. Morris. Nature, Volume 467 Number 7318, October 20, 2010

"Fathers' nutritional legacy." By Michael Skinner. Nature, Volume 467 Number 7318, October 20, 2010.

Brandon's Twitter stream, reportorial outtakes and citizen-funded White Nose Syndrome story; Wired Science on Twitter.

First All-Digital Science Textbook Will Be Free

Posted: 20 Oct 2010 11:50 AM PDT

Science textbooks are born as clunky, out-of-date tomes the moment they roll off the printing press. Research simply moves too fast for the publishing industry to keep up. Digital texts could end this cycle.

Textbooks designed to be all-digital and interactive from the start (as opposed to simply converting print books) could bring not only salvation to schools because they're easily updated, but also a revolution in how students learn science. Yet publishers are comfortable with a $5 billion-per-year college textbook industry that has recently seen price increases outpace inflation by more than 250 percent, and 99 percent of the market is tied to paper.

One not-for-profit organization is done waiting for the digital textbook revolution.

'We're trying to exploit the human brain, like videogames do.'

Within two and a half years, the E. O. Wilson Biodiversity Foundation, named after the naturalist and founder, hopes to complete a 59-chapter digital textbook about biology called Life on Earth. As each chapter is finished, the foundation plans to put it into the hands of anyone who wants it. For free.

We have video of the first chapter, "Cell Division," with interactive animations that will be integral to the text (see above). It will be available for download within a few weeks.

"I had taught elementary biology for 42 years, and I didn't need a lot of explanation to see immediately what a big difference this could make," Wilson said of the book in a promotional video (see below). "This is, in my opinion, an authentically revolutionary advance in science and technology education."

 

Neil Patterson, director of Life on Earth with 50 years of science textbook publishing experience to his name, said the format could revolutionize science education for students.

"Motion and film are powerful ways of teaching," Patterson said. "We're trying to exploit the human brain, like videogames do, and it's not a small matter to use technology now available to us."

By no "small matter," Patterson means money. Completing the book's chapters, laced with high-end interactive animations and video interviews with Nobel laureates, could cost as much as $10 million.

"No publisher is doing what we're doing, which is developing, from scratch, a serious digital textbook," Patterson said. He added that only $1 million of that funding — half of it from Life Technologies Foundation — is in place, and the remaining $9 million remains to be seen from private and public donors. "It's expensive, but once you're done you can keep it up to date across time, globally, essentially free of charge."

The foundation plans to sell university-level editions for about 10 percent of the cost of the average print textbook, in part to fund that continuous updating. Kindergarten through 12th grade editions will be free.

Patterson said the idea is to provide any student in the world unprecedented learning tools, but acknowledged imminent backlash from profit-seeking publishers.

"If we give away our stuff and they're trying to sell it, that's a serious threat," Patterson said. "That will be disconcerting to them, but eventually these publishers will be trying to produce what we're producing."

Looming threats to the print industry aside, the effort isn't without its digital critics.

Matt MacInnis, founder and CEO of digital publishing startup Inkling, said textbooks "have not yet evolved to meet the needs of today's student." But he suspects Life on Earth — which may come packaged with a homework server, community forums, a student data hub and other systems — will have to compete with school districts' existing multimillion-dollar investments in similar products.

"I think it's wonderful to see innovation like this, and it's noble to make great content available to schools free of charge, but I hope they're thinking beyond the book," MacInnis said. "By that I mean why would I, as a school, want to mess around with so many systems just for one text?"

Morgan Ryan, Life on Earth project director and a textbook developer of 20 years, didn't discount such problems, but thinks content is king.

"If you can create something vital for classrooms, something that they need, it will find its way into those classrooms," Ryan said, noting that schools will be free to use whatever portions of the book they see fit. "We're aiming for the highest quality of content and the lowest threshold of access possible here."

Regardless of the digital content teachers choose, affordable reading devices remain the biggest hurdle to student access.

"We've gone from the $999 laptop to $499 iPad in no time at all," MacInnis said. "I'm optimistic that in three to five years, device costs will no longer be a barrier."

Image and videos: E. O. Wilson Biodiversity Foundation

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Exoplanet’s Weird Hot Spot Defies Explanation

Posted: 20 Oct 2010 10:59 AM PDT

New observations from the Spitzer Space Telescope caught a giant exoplanet with a hot spot in the wrong place.

"We're seeing a planet whose hottest parts are not directly facing the star, but are almost a quarter of the way around the planet," said Ian Crossfield, a graduate student at the University of California, Los Angeles, and lead author of a paper presenting the new observations in the Astrophysical Journal. "It's exciting, and interestingly confusing."

The planet, called Upsilon Andromedae b, was one of the first hot Jupiters — giant planets several times the size of Jupiter that orbit searingly close to their stars — ever discovered. The planet's orbit is so tight that the same side faces the star at all times. One side boils at 2,700 degrees Fahrenheit, the night side simmers at a mere 1,100 degrees. and the two hemispheres are separated by a zone of perpetual twilight.

Astronomers expected the hottest point on such a planet's surface to face the sun. A few other planets have shown hot spots that were shifted a bit to one side, which could be explained by fast winds spreading through the planet's atmosphere.

But Upsilon Andromedae b's hottest point is shifted 84 degrees to the east, almost perpendicular to where astronomers expected to find it.

"That's a much bigger offset of a hot spot than has been seen for previous planets," Crossfield said. "It's going to be fun to try and figure out exactly what is going on on this planet."

 

To take the planet's temperature, Crossfield and colleagues used the Spitzer Space Telescope to measure the amount of infrared light coming from the star and the planet together. Because infrared light is a measure of heat, the pair of objects appears brighter when the planet's hot side faces the Earth.

The astronomers watched the planet over the course of 5 days, a little more than a year on Upsilon Andromedae b, in February 2009. Earlier measurements of how the planet's gravity tugs the star to and fro gave a detailed picture of how long the planet takes to go around the star — 4.6 Earth days — and when it passes behind the star.

To the team's surprise, the system appeared brightest when the planet was off to the side of the star, with its twilight edge facing Earth.

Stranger still, the planet showed a sharp temperature contrast between the night and day sides. A hot spot so close to the twilight zone should warm up the night side of the planet considerably, Crossfield said. But that's not what happened.

"It's not clear yet what's responsible or how to reconcile this," Crossfield said.

At this point, any explanation the team can offer is pure speculation, Crossfield stressed. But some candidates include supersonic winds that spark sonic booms, and currents flowing in the upper atmosphere through atoms so hot they've lost their electrons.

"These are things for which there's not a lot of observational evidence yet, but they can be tested by future observations," Crossfield said.

"I think this is one of the most intriguing new findings in exoplanet research," said Adam Burrows of Princeton University, who was not involved in the new study. But "given the extraordinary nature of the conclusions, caution is in order. One should wait for more data and more thinking about exactly what may be going on before concluding that something exotic is happening."

Video and image: NASA/JPL-Caltech

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Most Distant Galaxy Ever Confirmed

Posted: 20 Oct 2010 10:17 AM PDT

Astronomers' new observations have spotted the most distant galaxy ever seen. The galaxy's light comes from about 13.1 billion light-years away, making it one of the first galaxies to form after the Big Bang.

The new galaxy is about 30 million light-years farther away than previous record-holder, a gamma-ray burst that faded within a few hours of its peak brightness, and 200 million light-years farther than the next most distant galaxy.

"We are approaching the limits of the observable universe with this observation," said astronomer Michele Trenti of the University of Colorado, who was not involved in the new work. "It is quite a good improvement."

The finding, published in the Oct. 21 Nature, could also give insight into how young stars helped make the universe transparent.

The new distance champion, deemed UDFy-38135539, was first spotted in late 2009 in a Hubble Space Telescope image called the Ultra Deep Field. The image captures 10,000 galaxies in the universe's earliest epochs, several of which were good candidates for the most distant galaxy.

Because light takes time to travel across the universe, telescopes see these galaxies as they appeared billions of years ago. And because the universe is expanding, distant galaxies appear to be rapidly moving away from us. As the galaxies flee, the wavelength of the light they emit stretches out, or redshifts, similar to how an ambulance siren's howl drops in pitch as it drives away.

Matt Lehnert of the Paris Observatory and colleagues picked the reddest galaxy in the Ultra Deep Field, then took 16 hours of follow-up observations with the SINFONI spectrograph on the Very Large Telescope in Chile.

 

The team searched for the specific wavelength of light emitted when hydrogen, the most abundant element in the universe, relaxes from an excited energy state. Based on the amount of stretching this light experienced on its journey from the distant galaxy to the telescope, astronomers calculated that the galaxy is 13.1 billion light-years away, making it 30 million light-years farther than the next-most distant object ever found. The galaxy probably formed within 600 million years of the Big Bang.

Detecting this light at all was a surprising feat, Trenti said. "Most astronomers in the community think spectroscopic confirmation would have been very, very difficult. They were reluctant to try to invest a significant amount of telescope time to get the spectrum," he said. "Lehnert and colleagues went ahead and really showed that this can be done now, we don't have to wait for the next generation of more powerful telescopes."

A 30 million-light-year gain may not sound like much on the scale of the entire universe, Trenti added, but it's like breaking the world record in the 100 meter dash. "You run a few hundredths of a second faster, but that is a big deal," he said.

But the new galaxy is more than just "a trophy on the wall," Lehnert said. UDFy-38135539 is the first galaxy observed that formed during the "epoch of reionization," when radiation from infant stars split hydrogen atoms that fogged up the early universe into protons and electrons. Hydrogen absorbs light at most wavelengths, so without early stars, even nearby galaxies would be completely invisible to us.

Reionization began around 600 million years after the Big Bang and wrapped up a few hundred million years later, "which, for the universe, is relatively a blink of an eye," Lehnert said. "But we don't know how it happened." The new most-distant galaxy "basically helps to give us insight into the first galaxies, the galaxies that really were responsible for reionization."

Astronomers know one thing already: The new galaxy is not alone. The galaxy's young stars blew a transparent bubble of ions around it, which must be big enough to allow astronomers to see the galaxy from Earth. But observations suggest that the galaxy corrals only about 1 billion stars, making it at least 100 times smaller than the Milky Way — too small to blow such a big ionic bubble by itself.

"It must have had friends around it to help it," Lehnert said. "We have no idea what these friends are like … but this tells us they must be there, and we're feeling their presence."

The most likely candidates for these helpers are fainter galaxies, but they could be exotic objects like miniature black holes or decaying particles, Lehnert says.

Correction: A previous version of this article said the next most-distant object, a gamma-ray burst, was two light-years closer than this galaxy. The true figure is 30 million light-years.

Image: NASA/ESA/G. Illingworth/HUDF09 Team

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Posted by johnald