Friday, 15 January 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Satellite Photos of Haiti Before and After the Earthquake

Posted: 14 Jan 2010 03:07 PM PST

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The pictures and video from on-the-ground reports in Haiti following the magnitude 7 earthquake Tuesday are truly heartbreaking. But it is difficult to imagine the full extent of the damage to that country and its capital, Port-au-Prince, in particular. These new satellite images released Wednesday by Google and GeoEye show the devastation from above, giving a new view of the severity of this disaster. We've posted some of the images here. You can also scan the entire city with Google Earth as well.

The satellite image above, captured by the GeoEye-1 satellite Wednesday morning, shows the National Palace after the quake. Below is an image from March 2008.

Images: Google/Geoeye

Bizarre Sea Sponge Compound Finally Synthesized by Humans

Posted: 14 Jan 2010 01:12 PM PST


A 17-year long intense competition to synthesize a fascinatingly weird and complex compound has finally ended.

The first 25-step process for building the compound, Palau'amine, out of molecular components was published in Angewandte Chemie last week.

You might think that the substance causing all the fuss is slated to be a medical miracle, and indeed it does have some fascinating antifungal, antibiotic, and anticancer properties [pdf]. But the real reason dozens of chemistry PhD students put their blood, sweat, and tears into synthesizing it was simpler: glory.

Because the compound, called Palau'amine, is so strange and so difficult to make,it became a sort of Excalibur, with several labs around the world vying to be the first to build it. Many people had tried to synthesizethe chemical,and many had failed until Phil Baran's Scripps Oceanographic Institute team finally got it right.

"[Synthetic chemistry] is a voyage into finding out how little we know," Baran said.

After this particular adventure, we now know a little more about how to join atoms together in exotic molecular structures. It might not change your life today, but the techniques developed to build it could one day be used create other medicinal compounds

Palau'amine got its the name from its home island in the South Pacific. It was isolated from a marine sponge like the one in the photo above17 years ago. The sponge produces the strange substance to kill anything trying to eat it.

"It's known by the indigenous people of Palau as the toxic sponge," Baran said. "They know, don't mess with that sponge. And part of the reason is that it makes crazy things like this."

While the chemical synthesis of molecules may not be voted "Sexiest Field" in a scientific popularity contest, chemists like Baran and his competitors create the many drugs of modern medicine, among other things. The process of synthesizing molecules remains largely trial-and-error. Different substances are mixed at different temperatures and pressures in hopes of finding just the right transformations to create a desired configuration of atoms.

Some chemical structures are easy to create, while others possess attributes that make them particularly hard to build. Palau'amine represents the extreme end of the difficulty scale. Larry Overman, an organic chemist at the University of California, Irvine, told Chemical and Engineering News that "its nasty physical properties had undermined total synthesis endeavors in leading laboratories worldwide."

So, Baran's lab had to come up with some new ways of doing chemistry. First, they had to deal with its nine nitrogen atoms. Nitrogen atoms are extremely difficult to deal with at a molecular level. Baran said there's an old joke that "every one nitrogen atom adds seven years" to the PhD-student time necessary to learn to synthesize it. Most approaches to nitrogen components focus on covering them up with what Baran called "wet blanket" molecules that keep them messing up reactions.

"What we tried to do was take off the blanket and deal with the naked groups," he said. And it worked.

Second, the actual structure of the compound is difficult to hold together. Two of its ring structures in particular cause problems.

"It's a highly strained compound," Baran said. "If you make a plastic model of the compound, it wants to pop open."

The structure is so odd, in fact, that after years of study, the hypothesized structure of the compound had to be cast aside in 2007.

Despite the long history of synthesis failures, Baran's lab kept at it. While the rest of the chemistry world had been working with a flawed model structure, his team's work with other compounds produced by similar sponges led them to the right structure long before other scientists realized the errors in their ways.

Baran doesn't expect to see Palau'amine commercialized, so don't expect to see it curing disease anytime soon. Some of the tools his lab came up with to synthesize the compound, like a silver-based oxidizer, are already making their way into the chemistry world.

"The overriding goal is invention," Baran concluded. "The general theme of our lab is to at least match, if not outdo, nature."

Image: Baran Lab.

Citation: "Total Synthesis of Palauamine" by Ian Seiple, Shun Su, Ian S. Young, Chad A. Lewis, Junichiro Yamaguchi, and Phil S. Baran

See Also:

WiSci 2.0: Alexis Madrigal's Twitter, Google Reader feed, and green tech history research site; Wired Science on Twitter and Facebook.

Bird-Like Lungs May Have Helped Dinosaurs’ Ancestors Take Over Earth

Posted: 14 Jan 2010 12:06 PM PST

Lungs with one-way air flow may have helped dinosaurs' ancestors become dominant when oxygen levels dropped after the Permian-Triassic extinction, a period around 250 million years ago when most land-based life died off.

Air follows a one-way loop in alligator lungs, scientists found, a pattern also found in birds, which allows them to fly at high-altitude where oxygen levels are low. This similarity between bird and alligator lungs shows that one-way airflow emerged before the two groups split over 246 million years ago, said University of Utah evolutionary biologist C. G. Farmer, wholed the study, published Thursday in Science.

In turn, this lung structure may have enabled the common ancestors of dinosaurs and modern-day birds and alligators, the archosaurs, tothrive when oxygen levels dropped and killed off most other animals.

Before the extinction, synapsids, the ancestors to modern mammals, were the dominant group. But after the extinction, the archosaurs dwarfed the synapsids, Farmer said. Prestosuchids, for example,could reach 23 feet in length, while mammals' ancestors maxed out at just a few feet.

"We think mammals were unable to compete in niches that require some athleticism and a good set of lungs," Farmer said. "If you can't run you better hide, and you better be small enough to hide."

In mammals, air flows into the lungs through progressively smaller airways, stops in little sacs where oxygen is absorbed into the bloodand then reverses course and is exhaled by the same route. In birds, air goes one way through small tubes called parabronchi thatloop around to send the air back out.

This system allows modern birds to function in a low oxygen atmosphere. For instance, bar-headed geese can fly over the thin air above Mt. Everest, Farmer said. A similar ability to squeeze out ample oxygen from thin air probably gave bird's' archosaur ancestors an edge over the synapsids.

To see how alligator lungs worked, the group sedated six alligators, put flow-meters in their lungs and measured air flow once they awoke. They also cut out the lungs of alligators that had died on a Louisiana wildlife refugeand pumped air through the lungs. Finally, they pushed salt water filled with tiny fluorescent beads through a set of lungs from a dead alligator (see video).

This showed that like birds, the air flows into the chambers of alligators' lungs and follows a one-way path that loops back to the windpipe.

The findings on air-flow are convincing, said evolutionary biologist Elizabeth Brainerd of Brown University. "One of the strengths of the paper is the author used three different approaches to demonstrate the unidirectional air flow," she said.

But the claim that this trait may have helped archosaurs edge out the synapsids is "highly speculative," she said. To bolster thhe hypothesis, the group would need to show that this one-way flow is actually better at extracting oxygen.


Images: C. G. Farmer

See Also:

Citation: "Unidirectional Airflow in the Lungs of Alligators" byC. G. Farmerand Kent Sanders in Science, 15 January 2010, Vol 327.

Hubble Unravels Odd Galaxy’s History

Posted: 14 Jan 2010 10:47 AM PST


Not all spiral galaxies look or behave alike, as this new image from the Hubble Space Telescope of the unusual galaxy NGC 2976 shows.

Withthis new detailed view, astronomers were able to use the brightness and color of its stars to reconstruct the galaxy's history.

The galaxy, which is located 12 million light-years away in the constellation Ursa Major, has been shaped by its interaction with the M81 group of galaxies. M81 set off star birth in the distant past, but about 500 million years ago, new stars stopped bursting into existence through the outer galaxy. Some of the galaxy's gas was stripped away, and the rest collapsed to the center, leaving just a region 5,000 light-years wide near the core that is still making stars.

What look like grains of sand are individual stars. Blue giant stars highlight where the remaining active starmaking regions exist.

Image: NASA/ESA/J. Dalcanton/B. Williams. XXL image.

See Also:

WiSci 2.0: Alexis Madrigal's Twitter, Google Reader feed, and green tech history research site; Wired Science on Twitter and Facebook.