Friday, June 4, 2010

U OF T PALEONTOLOGISTS SOLVE MYSTERY OF 500 MILLION-YEAR-OLD SQUID-LIKE CARNIVORE

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A study by researchers at the University of Toronto and the Royal Ontario Museum sheds new light on a previously unclassifiable 500 million-year-old squid-like carnivore known as Nectocaris pteryx.

"We think that this extremely rare creature is an early ancestor of squids, octopuses, and other cephalopods," said Martin Smith of U of T's Department of Ecology and Evolutionary Biology (EEB) and the Department of Natural History at the ROM. "This is significant because it means that primitive cephalopods were around much earlier than we thought, and offers a reinterpretation of the long-held origins of this important group of marine animals."

The new interpretation became possible with the discovery of 91 new fossils that were collected by the ROM from the famous Burgess Shale site (Yoho National Park) in the UNESCO World Heritage Canadian Rocky Mountain Parks, British Columbia over the past three decades, and examined by PhD student Smith along with U of T EEB and geology assistant professor and ROM palaeontologist Jean-Bernard Caron.

"Previously, all knowledge of Nectocaris came from a lone specimen described in 1976. Due to the ambiguous characteristics evident on that specimen, Nectocaris has remained unclassified until now," said Smith, lead author of the study that will be published May 27 in Nature. "Our study reveals that Nectocaris is similar to known members of the modern cephalopod group, which includes squid, octopus, cuttlefish and the nautilus, as well as common fossils such as ammonites and belemnites, which are now extinct."

"We know very little about the relationships between the major groups of molluscs, and the early history of the group," said Smith. "Fossils like Nectocaris help us to map out how the groups alive today might be related, and how they evolved. This tells us something about how biodiversity originated in the past, and helps us to understand the rich tapestry of life today."

The new specimens, between two and five centimetres long, show that Nectocaris was kite-shaped and flattened from top to bottom, with large, stalked eyes and a long pair of grasping tentacles, which the researchers believe helped it to hunt for and consume prey. Smith and Caron further suggest that the creature swum using its large lateral fins, and, like modern cephalopods, probably used its nozzle-like funnel to accelerate by jet propulsion. "Some of the specimens' large gills were choked with mud, suggesting that the animals were fossilized after being caught in an underwater mud-flow," said Smith.

"Our findings mean that cephalopods originated 30 million years earlier than we thought, and much closer to the first appearance of complex animals in the 'Cambrian explosion'" said Smith. Nectocaris does not have a mineralized shell, a fact that surprised the scientists. "It's long been thought that cephalopods evolved in the Late Cambrian period, when gradual modifications to the shells of creeping, snail-like animals made them able to float. Nectocaris shows us that the first cephalopods actually started swimming without the aid of gas-filled shells. Shells evolved much later, probably in response to increased levels of competition and predation in the Late Cambrian."

"Modern cephalopods are very complex, with intricate organs and startling intelligence. We go from very simple pre-Cambrian life-forms to something as complex as a cephalopod in the geological blink of an eye, which illustrates just how quickly evolution can produce complexity."

Smith says Nectocaris proves that there are still surprises in the fossil record. "Fossils can only ever tell us a part of the story," he said. "Exceptional soft-bodied fossils such as Nectocaris, combined with advances in developmental and molecular biology, still have a lot to bring to the table, and I'm sure that they will continue to help to refine and replace our current hypotheses."

University of Toronto

'NATURE'S BATTERIES' MAY HAVE HELPED POWER EARLY LIFEFORMS

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Researchers at the University of Leeds have uncovered new clues to the origins of life on Earth. The team found that a compound known as pyrophosphite may have been an important energy source for primitive lifeforms.

There are several conflicting theories of how life on Earth emerged from inanimate matter billions of years ago – a process known as abiogenesis.

"It's a chicken and egg question," said Dr Terry Kee of the University of Leeds, who led the research. "Scientists are in disagreement over what came first – replication, or metabolism. But there is a third part to the equation – and that is energy."

All living things require a continual supply of energy in order to function. This energy is carried around our bodies within certain molecules, one of the best known being ATP, which converts heat from the sun into a useable form for animals and plants.

At any one time, the human body contains just 250g of ATP – this provides roughly the same amount of energy as a single AA battery. This ATP store is being constantly used and regenerated in cells via a process known as respiration, which is driven by natural catalysts called enzymes.

"You need enzymes to make ATP and you need ATP to make enzymes," explained Dr Kee. "The question is: where did energy come from before either of these two things existed? We think that the answer may lie in simple molecules such as pyrophosphite which is chemically very similar to ATP, but has the potential to transfer energy without enzymes."

The key to the battery-like properties of both ATP and pyrophosphite is an element called phosphorus, which is essential for all living things. Not only is phosphorus the active component of ATP, it also forms the backbone of DNA and is important in the structure of cell walls.

But despite its importance to life, it is not fully understood how phosphorus first appeared in our atmosphere. One theory is that it was contained within the many meteorites that collided with the Earth billions of years ago.

"Phosphorus is present within several meteoritic minerals and it is possible that this reacted to form pyrophosphite under the acidic, volcanic conditions of early Earth," added Dr Kee.

The findings, published in the journal Chemical Communications, are the first to suggest that pyrophosphite may have been relevant in the shift from basic chemistry to complex biology when life on earth began. Since completing this research, Dr Kee and his team have found even further evidence for the importance of this molecule and now hope to team up with collaborators from NASA to investigate its role in abiogenesis.

(Photo: University of Leeds)

University of Leeds

SHARKSKIN FOR AIRPLANES, SHIPS AND WIND ENERGY PLANTS

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To lower the fuel consumption of airplanes and ships, it is necessary to reduce their flow resistance, or drag. An innovative paint system makes this possible. This not only lowers costs, it also reduces CO2 emissions.

The inspiration – and model – for the paint‘s structure comes from nature: The scales of fast-swimming sharks have evolved in a manner that significantly diminishes drag, or their resistance to the flow of currents. The challenge was to apply this knowledge to a paint that could withstand the extreme demands of aviation. Temperature fluctuations of -55 to +70 degrees Celsius; intensive UV radiation and high speeds. Yvonne Wilke, Dr. Volkmar Stenzel and Manfred Peschka of the Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research IFAM in Bremen developed not only a paint that reduces aerodynamic drag, but also the associated manufacturing technology. In recognition of their achievement, the team is awarded the 2010 Joseph von Fraunhofer Prize.

The paint involves of a sophisticated formulation. An integral part of the recipe: the nanoparticles, which ensure that the paint withstands UV radiation, temperature change and mechanical loads, on an enduring basis. „Paint offers more advantages," explains Dr. Volkmar Stenzel. „It is applied as the outermost coating on the plane, so that no other layer of material is required. It adds no additional weight, and even when the airplane is stripped – about every five years, the paint has to be completely removed and reapplied – no additional costs are incurred. In addition, it can be applied to complex three-dimensional surfaces without a problem." The next step was to clarify how the paint could be put to practical use on a production scale. „Our solution consisted of not applying the paint directly, but instead through a stencil," says Manfred Peschka. This gives the paint its sharkskin structure. The unique challenge was to apply the fluid paint evenly in a thin layer on the stencil, and at the same time ensure that it can again be detached from the base even after UV radiation, which is required for hardening.

When applied to every airplane every year throughout the world, the paint could save a volume of 4.48 million tons of fuel. This also applies to ships: The team was able to reduce wall friction by more than five percent in a test with a ship construction testing facility. Extrapolated over one year, that means a potential savings of 2,000 tons of fuel for a large container ship. With this application, the algae or muscles that attach to the hull of a ship only complicate things further. Researchers are working on two solutions for the problem. Yvonne Wilke explains: „One possibility exists in structuring the paint in such a way that fouling organisms cannot get a firm grasp and are simply washed away at high speeds, for example. The second option aims at integrating an anti-fouling element – which is incompatible for nature."

Irrespective of the fuel savings, there are even more interesting applications – for instance, with wind energy farms. Here as well, air resistance has a negative effect on the rotor blades. The new paint would improve the degree of efficiency of the systems – and thus the energy gain.

(Photo: Fraunhofer / Dirk Mahler)

Fraunhofer Institute

HOUSEHOLD DETERGENTS, SHAMPOOS MAY FORM HARMFUL SUBSTANCE IN WASTEWATER

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Scientists are reporting evidence that certain ingredients in shampoo, detergents and other household cleaning agents may be a source of precursor materials for formation of a suspected cancer-causing contaminant in water supplies that receive water from sewage treatment plants. The study sheds new light on possible environmental sources of this poorly understood water contaminant, called NDMA, which is of ongoing concern to health officials. Their study is in ACS' Environmental Science & Technology, a semi-monthly journal.

William Mitch and colleagues note that scientists have known that NDMA and other nitrosamines can form in small amounts during the disinfection of wastewater and water with chloramine. Although nitrosamines are found in a wide variety of sources — including processed meats and tobacco smoke — scientists know little about their precursors in water. Past studies with cosmetics have found that substances called quaternary amines, which are also ingredients in household cleaning agents, may play a role in the formation of nitrosamines.

Their laboratory research showed that when mixed with chloramine, some household cleaning products — including shampoo, dishwashing detergent and laundry detergent - formed NDMA. The report notes that sewage treatment plants may remove some of quaternary amines that form NDMA. However, quaternary amines are used in such large quantities that some still may persist and have a potentially harmful effect in the effluents from sewage treatment plants.

(Photo: iStock)

American Chemical Society

HEY JUDE: GET THAT SONG OUT MY HEAD!

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Some 98 to 99 percent of the population has, at some point, been "infected" with a song they just can't seem to shake off. This common phenomenon has rarely been researched, until Andréane McNally-Gagnon, a PhD student at the University of Montreal Department of Psychology, decided to examine the issue in an ongoing investigation.

In most cases, earworms will disappear after a few minutes. In some cases, earworms can last hours or even days. McNally-Gagnon is also a musician, who is often infected, which is why she wanted to better understand how and why it occurs.

For starters, she asked French-speaking Internet users to rank 100 pop songs according to their ability to be compulsively repeated within one's mind. The top five were: Singing in the Rain (Gene Kelly), Live Is Life (Opus), Don't Worry, Be Happy (Bobby McFerrin), I Will Survive (Gloria Gaynor) and, in first place, Ça fait rire les oiseaux by Caribbean sensation La Compagnie Créole. (A complete list is published at www.brams.org).

In the laboratory, McNally-Gagnon and her thesis director Sylvie Hébert, professor at the University of Montreal School of Speech Therapy and Audiology and a member of the International Laboratory for Brain, Music and Sound Research (BRAMS), asked 18 musicians and 18 non-musicians to hum and record their obsessive songs and note their emotional state before and after. The researchers found earworm infections last longer with musicians than with non-musicians.

The phenomenon occurs when subjects are usually in a positive emotional state and keeping busy with non-intellectual activities such as walking, which requires little concentration. "Perhaps the phenomenon occurs to prevent brooding or to change moods," says Hébert.

The study also revealed that auditive memory in people is can accurately replicate songs. Humming among musicians was only one key off original recordings, while non-musicians were off by two keys.

McNally-Gagnon and Hébert now plan to study earworms using MRI or Transcranial Magnetic Stimulation technology. "The only such studies that have been conducted were on test subjects who mentally imagined a song," says Hébert. "We believe the neurological process is different with earworms, because the phenomenon is involuntary."

(Photo: U. Montreal)

University of Montreal

ASTRONOMERS DISCOVER NEW STAR-FORMING REGIONS IN MILKY WAY

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Astronomers studying the Milky Way have discovered a large number of previously-unknown regions where massive stars are being formed. Their discovery provides important new information about the structure of our home Galaxy and promises to yield new clues about the chemical composition of the Galaxy.

"We can clearly relate the locations of these star-forming sites to the overall structure of the Galaxy. Further studies will allow us to better understand the process of star formation and to compare the chemical composition of such sites at widely different distances from the Galaxy's center," said Thomas Bania, of Boston University.

Bania worked with Loren Anderson of the Astrophysical Laboratory of Marseille in France, Dana Balser of the National Radio Astronomy Observatory (NRAO), and Robert Rood of the University of Virginia. The scientists presented their findings to the American Astronomical Society's meeting in Miami, Florida.

The star-forming regions the astronomers sought, called H II regions, are sites where hydrogen atoms are ionized, or stripped of their electrons, by the intense radiation of the massive, young stars. To find these regions hidden from visible-light detection by the Milky Way's gas and dust, the researchers used infrared and radio telescopes.

"We found our targets by using the results of infrared surveys done with NASA's Spitzer Space Telescope and of surveys done with the National Science Foundation's (NSF) Very Large Array (VLA) radio telescope," Anderson said. "Objects that appear bright in both the Spitzer and VLA images we studied are good candidates for H II regions," he explained.

The astronomers then used the NSF's giant Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, an extremely sensitive radio telescope. With the GBT, they were able to detect specific radio frequencies emitted by electrons as they recombined with protons to form hydrogen. This evidence of recombination confirmed that the regions contained ionized hydrogen and thus are H II regions.

Further analysis allowed the astronomers to determine the locations of the H II regions. They found concentrations of the regions at the end of the Galaxy's central bar and in its spiral arms. Their analysis also showed that 25 of the regions are farther from the Galaxy's center than the Sun.

"Finding the ones beyond the solar orbit is important, because studying them will provide important information about the chemical evolution of the Galaxy. There is evidence that the abundance of heavy elements changes with increasing distance from the Galactic center. We now have many more objects to study and improve our understanding of this effect," Bania said.

(Photo: NASA/JPL-Caltech/R. Hurt (SSC-Caltech))

National Radio Astronomy Observatory

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