Crocs Uncover

Bizarre Species

jueves, 30 de septiembre de 2010

Russian Firm Plans Commercial Space Station

Buoyed by plans for commercial space taxis, a Russian company plans to build and launch a privately owned outpost in orbit for tourists, scientists and other paying visitors.

RSC Energia, which designed and built the Russian modules of the International Space Station, is partnering with Russian commercial space startup Orbital Technologies to manufacture the new hub, currently known as Commercial Space Station.

Unlike the International Space Station, the CSS will be assembled on the ground and put into orbit by a single Soyuz rocket, according to Orbital Technologies CEO Sergey Kostenko.

Designs for the seven-person outpost are complete and construction is expected to begin in 2012 or 2013. Launch would take place about two years later. Prices to stay on the station have not yet been determined, Kostenko said in an interview.

“I’m very optimistic about space tourism in the future,” he said.

Orbital Technologies is working with the U.S.-based Space Adventures, which arranged eight privately paid visits to the International Space Station via Russian Soyuz vehicles and which recently announced an agreement to market Boeing’s planned commercial crew capsules.

Kostenko said his firm is looking to partner with Boeing, SpaceX, Russia, China and any other country or company with the capability of flying people to and from the Commercial Space Station.

“All space transportation systems are welcome,” he said.

The outpost, which will be left unoccupied between visits, will have some science facilities for experiments. Kostenko said he expects about half the visitors simply will want to look out the windows.

Each seven-member crew will include one commander who is a professional astronaut and six non-professional fliers, Kostenko said.

The project is similar to plans by Las Vegas-based Bigelow Aerospace for inflatable habitats for tourism, science and entertainment.

“Bigelow is a competitor. That's all I’m going to say about that,” Kostenko said.

Orbital Technologies plans to put its station in the same orbit as the International Space Station and make it available as a emergency evacuation shelter.

Image: The Commercial Space Station includes sleeping berths for four, leaving three visitors to bunk down in their space taxi or a nook in the station. It is being designed so that vehicles from any country or company can berth. Top: Commercial Space Station. Bottom: Commercial Space Station in section (Orbital Technologies, Ltd.) [source]

In to the Cristal Caves

NGC goes inside one of the greatest natural marvels on the planet - a giant crystal cave described as Superman's fortress, with magnificent crystals up to 36 feet long and weighing 55 tons. A team of experts venture into the cavern, enduring scorching-hot temperatures that could kill a human after just 15 minutes of exposure. They'll push the boundaries of physical limitation to explore a crevasse that could lead to another - and perhaps more spectacular - crystal cave.

Cavers exploring Naica's Los Crystales cave where more than a hundred giant crystals have grown.

Jaguar Builds A Twin-Turbine Electric Supercar You Can’t Have

PARIS — One of the joys of the modern auto show is the flight of fancy known as the concept car. In the interest of generating buzz and flexing muscles, automakers trot out impossibly beautiful design and engineering studies that have no hope of production, machines that will never see a showroom or roll down a public road under their own power. At this year’s Paris auto show, Jaguar unveiled the C-X75, a twin-turbine-equipped, electrically powered, four-wheel-drive, 205-mph slice of wonderful that you won’t ever be able to buy.

You can be forgiven if the curves look familiar. The C-X75 was created to celebrate Jaguar’s 75th anniversary, and as such, it purposely recalls iconic speed sleds like the XJ13 of the 1960s and the XJ220 of the 1990s.

The C-X75’s voluptuous lines hide a range-extending hybrid powetrain akin to the one found in the Chevrolet Volt; four 195-horsepower electric motors, one at each wheel, are paired with two 80,000-rpm gasoline turbines that live under the Jag’s rear lid. Jaguar claims that each motor weighs a scant 50 kg and that, in total, the car is capable of producing 780 hp and 1180 lb-ft of torque. Power is stored in a 19-kWH, 330-pound lithium-ion battery pack that can provide up to 68 miles of electric-only driving. 62 mph arrives in a scant 3.4 seconds.

Like most supercar concepts, the Jag boasts a host of staggeringly expensive, eye-candy-laden features. The turbines, axial-flow micro units that were developed in concert with Bladon Jets, are the result of a joint project with the British government-sponsored Technology Strategy Board. The car’s interior is a mass of TFT screens, polished metal, and stretched leather. The aluminum bodywork houses an adjustable-vane exhaust—those turbines have to breathe, after all—and a carbon-fiber-clad rear diffuser that looks like the business end of a Transformer in heat.

In short, the C-X75 is impractical. In many ways, it’s disconnected from reality. It likely cost more than a hundred government toilets and has as much chance of ending up in our driveway as the Eiffel Tower. And, crucially, it plucks a few heartstrings by name-checking history and the cars we loved when we were little.

In other words, it’s exactly the kind of thing we go to auto shows to see.

Newly Discovered Planet May Be First Truly Habitable Exoplanet

A team of planet hunters led by astronomers at the University of California, Santa Cruz, and the Carnegie Institution of Washington has announced the discovery of an Earth-sized planet (three times the mass of Earth) orbiting a nearby star at a distance that places it squarely in the middle of the star's "habitable zone," where liquid water could exist on the planet's surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one.
To astronomers, a "potentially habitable" planet is one that could sustain life, not necessarily one that humans would consider a nice place to live. Habitability depends on many factors, but liquid water and an atmosphere are among the most important.

"Our findings offer a very compelling case for a potentially habitable planet," said Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz. "The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common."

The findings are based on 11 years of observations at the W. M. Keck Observatory in Hawaii. "Advanced techniques combined with old-fashioned ground-based telescopes continue to lead the exoplanet revolution," said Paul Butler of the Carnegie Institution. "Our ability to find potentially habitable worlds is now limited only by our telescope time."

Vogt and Butler lead the Lick-Carnegie Exoplanet Survey. The team's new findings are reported in a paper to be published in The Astrophysical Journal and posted online at Coauthors include associate research scientist Eugenio Rivera of UC Santa Cruz; associate astronomer Nader Haghighipour of the University of Hawaii-Manoa; and research scientists Gregory Henry and Michael Williamson of Tennessee State University.

The paper reports the discovery of two new planets around the nearby red dwarf star Gliese 581. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system other than our own solar system. Like our solar system, the planets around Gliese 581 have nearly circular orbits.

The most interesting of the two new planets is Gliese 581g, with a mass three to four times that of the Earth and an orbital period of just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and that it has enough gravity to hold on to an atmosphere, according to Vogt.

Gliese 581, located 20 light years away from Earth in the constellation Libra, has a somewhat checkered history of habitable-planet claims. Two previously detected planets in the system lie at the edges of the habitable zone, one on the hot side (planet c) and one on the cold side (planet d). While some astronomers still think planet d may be habitable if it has a thick atmosphere with a strong greenhouse effect to warm it up, others are skeptical. The newly discovered planet g, however, lies right in the middle of the habitable zone.

"We had planets on both sides of the habitable zone--one too hot and one too cold--and now we have one in the middle that's just right," Vogt said.

The planet is tidally locked to the star, meaning that one side is always facing the star and basking in perpetual daylight, while the side facing away from the star is in perpetual darkness. One effect of this is to stabilize the planet's surface climates, according to Vogt. The most habitable zone on the planet's surface would be the line between shadow and light (known as the "terminator"), with surface temperatures decreasing toward the dark side and increasing toward the light side.

"Any emerging life forms would have a wide range of stable climates to choose from and to evolve around, depending on their longitude," Vogt said.

The researchers estimate that the average surface temperature of the planet is between -24 and 10 degrees Fahrenheit (-31 to -12 degrees Celsius). Actual temperatures would range from blazing hot on the side facing the star to freezing cold on the dark side.

If Gliese 581g has a rocky composition similar to the Earth's, its diameter would be about 1.2 to 1.4 times that of the Earth. The surface gravity would be about the same or slightly higher than Earth's, so that a person could easily walk upright on the planet, Vogt said.

The new findings are based on 11 years of observations of Gliese 581 using the HIRES spectrometer (designed by Vogt) on the Keck I Telescope at the W. M. Keck Observatory in Hawaii. The spectrometer allows precise measurements of a star's radial velocity (its motion along the line of sight from Earth), which can reveal the presence of planets. The gravitational tug of an orbiting planet causes periodic changes in the radial velocity of the host star. Multiple planets induce complex wobbles in the star's motion, and astronomers use sophisticated analyses to detect planets and determine their orbits and masses.

"It's really hard to detect a planet like this," Vogt said. "Every time we measure the radial velocity, that's an evening on the telescope, and it took more than 200 observations with a precision of about 1.6 meters per second to detect this planet."

To get that many radial velocity measurements (238 in total), Vogt's team combined their HIRES observations with published data from another group led by the Geneva Observatory (HARPS, the High Accuracy Radial velocity Planetary Search project).

In addition to the radial velocity observations, coauthors Henry and Williamson made precise night-to-night brightness measurements of the star with one of Tennessee State University's robotic telescopes. "Our brightness measurements verify that the radial velocity variations are caused by the new orbiting planet and not by any process within the star itself," Henry said.

The researchers also explored the implications of this discovery with respect to the number of stars that are likely to have at least one potentially habitable planet. Given the relatively small number of stars that have been carefully monitored by planet hunters, this discovery has come surprisingly soon.

"If these are rare, we shouldn't have found one so quickly and so nearby," Vogt said. "The number of systems with potentially habitable planets is probably on the order of 10 or 20 percent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that's a large number. There could be tens of billions of these systems in our galaxy."

This research was supported by grants from the National Science Foundation and NASA.

Scientists Genetically Engineer Silkworms to Produce Artificial Spider Silk

A research and development effort by the University of Notre Dame, the University of Wyoming, and Kraig Biocraft Laboratories, Inc. has succeeded in producing transgenic silkworms capable of spinning artificial spider silks.

"This research represents a significant breakthrough in the development of superior silk fibers for both medical and non-medical applications," said Malcolm J. Fraser Jr., a Notre Dame professor of biological sciences. "The generation of silk fibers having the properties of spider silks has been one of the important goals in materials science."

Natural spider silks have a number of unusual physical properties, including significantly higher tensile strength and elasticity than naturally spun silkworm fibers. The artificial spider silks produced in these transgenic silkworms have similar properties of strength and flexibility to native spider silk.

Silk fibers have many current and possible future biomedical applications, such as use as fine suture materials, improved wound healing bandages, or natural scaffolds for tendon and ligament repair or replacement. Spider silk-like fibers may also have applications beyond biomedical uses, such as in bulletproof vests, strong and lightweight structural fabrics, a new generation athletic clothing and improved automobile airbags.

Until this breakthrough, only very small quantities of artificial spider silk had ever been produced in laboratories, but there was no commercially viable way to produce and spin these artificial silk proteins. Kraig Biocraft believed these limitations could be overcome by using recombinant DNA to develop a bio-technological approach for the production of silk fibers with a much broader range of physical properties or with pre-determined properties, optimized for specific biomedical or other applications.

The firm entered into a research agreement with Fraser, who discovered and patented a powerful and unique genetic engineering tool called "piggyBac." PiggyBac is a piece of DNA known as a transposon that can insert itself into the genetic machinery of a cell.

"Several years ago, we discovered that the piggyBac transposon could be useful for genetic engineering of the silkworm, and the possibilities for using this commercial protein production platform began to become apparent."

Fraser, with the assistance of University of Wyoming researcher Randy Lewis, a biochemist who is one of the world's foremost authorities on spider silk, and Don Jarvis, a noted molecular geneticist who specializes in insect protein production, genetically engineered silkworms in which they incorporated specific DNAs taken from spiders. When these transgenic silkworms spin their cocoons, the silk produced is not ordinary silkworm silk, but, rather, a combination of silkworm silk and spider silk. The genetically engineered silk protein produced by the transgenic silkworms has markedly improved elasticity and strength approaching that of native spider silk.

"We've also made strides in improving the process of genetic engineering of these animals so that the development of additional transgenics is facilitated," Fraser said. "This will allow us to more rapidly assess the effectiveness of our gene manipulations in continued development of specialized silk fibers."

Since silkworms are already a commercially viable silk production platform, these genetically engineered silkworms effectively solve the problem of large scale production of engineered protein fibers in an economically practical way.

"Using this entirely unique approach, we have confirmed that transgenic silkworms can be a potentially viable commercial platform for production of genetically engineered silk proteins having customizable properties of strength and elasticity," Fraser said. "We may even be able to genetically engineer fibers that exceed the remarkable properties of native spider silk."

The genetic engineering breakthrough was announced Sept. 29 by Fraser, Lewis and Kraig Biocraft CEO Kim Thompson at a press conference on the Notre Dame campus.

New Key to Tissue Regeneration: Drug Treatment Triggers Sodium Ions to Regrow Nerves and Muscle

Sodium gets a bad rap for contributing to hypertension and cardiovascular disease. Now biologists at Tufts University's School of Arts and Sciences have discovered that sodium also plays a key role in initiating a regenerative response after severe injury. The Tufts scientists have found a way to regenerate injured spinal cord and muscle by using small molecule drugs to trigger an influx of sodium ions into injured cells.

The approach breaks new ground in the field of biomedicine because it requires no gene therapy; can be administered after an injury has occurred and even after the wound has healed over; and is bioelectric, rather than chemically based.

In a paper appearing as the cover story of the September 29, 2010, issue of the Journal of Neuroscience, the Tufts team reported that a localized increase in sodium ions was necessary for young Xenopus laevis tadpoles to regenerate their tails - complex appendages containing spinal cord, muscle and other tissue.

Like human beings, who regenerate fingertips only as children, these tadpoles lose the ability to regenerate their tail with age. Most remarkably, it was shown that such "refractory" tadpoles whose tails had been removed could be induced to make a perfect new tail by only an hour of treatment with a specific drug cocktail.

The findings have tremendous implications for treating wounds sustained in war as well as accidental injuries. The treatment method used is most directly applicable to spinal cord repair and limb loss, which are highly significant medical problems world-wide. It also demonstrates a proof-of-principle that may be applicable to many complex organs and tissues.

"We have significantly extended the effective treatment window, demonstrating that even after scar-like wound covering begins to form, control of physiological signals can still induce regeneration. Artificially causing an influx of sodium for just one hour can overcome a variety of problems, such as the decline in regenerative ability that comes with age and the effect of regeneration-blocking drugs," said Tufts Professor of Biology Michael Levin, Ph.D., corresponding author on the paper and director of the Center for Regenerative and Developmental Biology at Tufts. Co-authors were Research Associate Ai-Sun Tseng, Postdoctoral Associate Wendy S. Beane, Research Associate Joan M. Lemire, and Alessio Masi, a former post-doctoral associate in Levin's laboratory.

The transport of ions in and out of cells is regulated by electronic security doors, or gates, that let in specific ions under certain circumstances. A role for sodium current in tissue regeneration had been proposed in the past, but this is the first time the molecular-genetic basis of the ion flow has been identified, and a specific drug-based treatment demonstrated. Until now, advances in this model system had involved administering therapies before the injury was sustained.

"This is a novel, biomedically-relevant approach to inducing regeneration of a complex appendage," noted Levin.

The Tufts research established a novel role in regeneration for the sodium channel Nav1.2, a crucial component of nerve and cardiac function. It showed that local, early increase in intracellular sodium is required for initiating regeneration following Xenopus tail amputation, while molecular and pharmacological inhibition of sodium transport causes regenerative failure. The new treatment induced regeneration only of correctly-sized and patterned tail structures and did not generate ectopic or other abnormal growth.

"The ability to restore regeneration using a temporally-controllable pharmacological approach not requiring gene therapy is extremely exciting," said the researchers.

Of critical importance, they said, was the discovery that the tail could be induced to regenerate as late as 18 hours after amputation, revealing that tissues normally fated for regenerative failure still maintain their intrinsic characteristics and can be programmed to reactivate regeneration.

Amphibians such as frogs can restore organs lost during development, including the lens and tail. The frog tail is a good model for human regeneration because it repairs injury in the same way that people do: each tissue makes more of itself. (In contrast, regeneration in some other animals occurs through transdifferentiation (one cell type turns into another cell type) or adult stem cell differentiation. Furthermore, though small, the Xenopus larval tail is complex, with muscle, spinal cord, peripheral nerves and vasculature cells.

The National Institutes of Health, National Highway Traffic Safety Administration, Department of Defense and Defense Advanced Research Projects Agency funded the work.

No Evidence for Clovis Comet Catastrophe, Archaeologists Say

New research challenges the controversial theory that an ancient comet impact devastated the Clovis people, one of the earliest known cultures to inhabit North America.
Writing in the October issue of Current Anthropology, archaeologists Vance Holliday (University of Arizona) and David Meltzer (Southern Methodist University) argue that there is nothing in the archaeological record to suggest an abrupt collapse of Clovis populations. "Whether or not the proposed extraterrestrial impact occurred is a matter for empirical testing in the geological record," the researchers write. "Insofar as concerns the archaeological record, an extraterrestrial impact is an unnecessary solution for an archaeological problem that does not exist."

The comet theory first emerged in 2007 when a team of scientists announced evidence of a large extraterrestrial impact that occurred about 12,900 years ago. The impact was said to have caused a sudden cooling of the North American climate, killing off mammoths and other megafauna. It could also explain the apparent disappearance of the Clovis people, whose characteristic spear points vanish from the archaeological record shortly after the supposed impact.

As evidence for the rapid Clovis depopulation, comet theorists point out that very few Clovis archaeological sites show evidence of human occupation after the Clovis. At the few sites that do, Clovis and post-Clovis artifacts are separated by archaeologically sterile layers of sediments, indicating a time gap between the civilizations. In fact, comet theorists argue, there seems to be a dead zone in the human archaeological record in North America beginning with the comet impact and lasting about 500 years.

But Holliday and Meltzer dispute those claims. They argue that a lack of later human occupation at Clovis sites is no reason to assume a population collapse. "Single-occupation Paleoindian sites -- Clovis or post-Clovis -- are the norm," Holliday said. That's because many Paleoindian sites are hunting kill sites, and it would be highly unlikely for kills to be made repeatedly in the exact same spot.

"So there is nothing surprising about a Clovis occupation with no other Paleoindian zone above it, and it is no reason to infer a disaster," Holliday said.

In addition, Holliday and Meltzer compiled radiocarbon dates of 44 archaeological sites from across the U.S. and found no evidence of a post-comet gap. "Chronological gaps appear in the sequence only if one ignores standard deviations (a statistically inappropriate procedure), and doing so creates gaps not just around [12,900 years ago] but also at many later points in time," they write.

Sterile layers separating occupation zones at some sites are easily explained by shifting settlement patterns and local geological processes, the researchers say. The separation should not be taken as evidence of an actual time gap between Clovis and post-Clovis cultures.

Holliday and Meltzer believe that the disappearance of Clovis spear points is more likely the result of a cultural choice rather than a population collapse. "There is no compelling data to indicate that North American Paleoindians had to cope with or were affected by a catastrophe, extraterrestrial or otherwise, in the terminal Pleistocene," they conclude.

lunes, 27 de septiembre de 2010

A Pod Car of One's Own

About 15 years ago I asked my family why we didn't have personal vehicles that move on tracks around town instead of cars. Little did I know that there were other people actually making it happen. A new generation of pod cars is poised to take off down the tracks.

Pod cars are usually called personal rapid transit or PRT, and several systems have been around since the gas crisis of the 1970s. They're different from trams or elevated trains that have connected cars for passengers. Instead, PRT involves small automated pods that carry up to six passengers from point to point. Imagine something like a gondola moving horizontally on tracks.

The beauty of PRT is that you can choose your destination and your fellow passengers. Anyone who has been squashed into an armpit on the subway knows what I'm talking about. PRT cars are electric-powered, quiet, don't require drivers and use very little energy and land. So why aren't they everywhere?

Actually PRT systems do exist stateside in West Virginia, Florida, Texas and Micigan. But as's Curtis Johnson points out, these early versions were like the first IBM personal computers -- slow and clunky. The PRT in Morgantown, W.V., has become known for its long delays. New systems are more advanced.

London's Heathrow Airport is testing one built by ULTra PRT and the city of San Jose is conducting a PRT feasibility study, Jim Witkin writes on the New York Times Wheels blog. Heathrow's futuristic system includes 21 vehicles that run among three stations. A ride in either direction of the 1.2-mile guideway takes about six minutes, according to ULTra's site.

Even the slickest, most modern PRT systems face significant hurdles. The city of Winona, Minn., wanted to build one but their application for $25 million in federal funding to build a test facility was denied. Critics also worry that PRT will draw riders away from other forms of public transport, which already face budget strains. Plus, gaining the right of way for such a system is no easy task.

The bike, the bus, a carsharing service and rides from friends have made it possible for me to stay car-free, but a pod car system could make it even more tempting to ditch car ownership, if you only need one to get you down that last mile. That's the dream: a pod of one's own.

Photo: A PRT vehicle that's part of the new ULTra network being tested at London's Heathrow Airport. Credit: ULTra.

Unmanned Airplanes Coming to a Terminal Near You

* Unmanned aircraft could be making their way from the battlefield to the airport.
* These planes would most likely be used to police the skies, patrol borders and transport cargo.
* The human fear factor will likely prevent the idea of a passenger airline without a human at the helm, however.

Unmanned airplanes have almost become another branch of the military, dropping bombs, spying on terrorist camps and even threatening enemy aircraft in Iraq and Afghanistan.

Now government and aviation experts are planning to make room for more robot aircraft over domestic skies: working as airborne traffic cops, patrolling the border and maybe even shuttling cargo between cities.

It's not a sci-fi fantasy. In fact, the Federal Aviation Administration is now studying how to safely fit these unmanned aircraft into the nation's busy commercial airspace.

"The success in the military has started to bleed over to the civilian environment," said Wesley Randall, a former Air Force logistics officer and professor at Auburn University's department of supply chain management. "People are saying this isn't a niche, gee-whiz technology. These are things you need to think about."

The FAA granted Randall and his colleagues at Auburn a $300,000 grant last week to do safety-related analyses of unmanned aerial systems. The government currently permits some law enforcement agencies to fly remote-control aircraft with a waiver from federal rules.

But the numbers of unmanned vehicles -- and their uses -- are growing. That means a greater chance of something going wrong.

Randall and his team will consider how and where robot craft should fly -- which altitude, which routes and at what times.

There are bigger questions as well. Should these drones be part of the FAA's air traffic control system and get directions from control towers? Should remotely-operated pilots with joysticks have the same training as commercial pilots? Who's responsible if there's a crash?

Peter Singer is author of the new book "Wired For War" and is a senior fellow at the Brookings Institute in Washington, D.C. He says that unmanned aircraft are inching closer to prime-time, following a well-trodden march of technology from military to civilian uses.

"Nobody is saying that all humans will be replaced in war," Singer said. "But there are always evolving roles in war and civilian society. Next couple decades there will be some kind of pairing of humans and unmanned systems."

That synergy of man and machine is already happening in the military.

Northrop Grumman is building the world's first unmanned combat aircraft for the Navy. The $635 million X-47B takes its test flight from an aircraft carrier deck in December. Last year, Air Force officials awarded "aircraft wings" to 24 new cadets to pilot unmanned aerial systems.

Even though commercial pilots use automatic controls to fly and land modern jetliners, the human fear factor will likely prevent the idea of a passenger airline without a human at the helm. "Somebody could invent a remotely piloted airliner and nobody would fly it," Randall said.

But cargo planes might work. Randall notes that unmanned airplanes could carry cargo loads across unpopulated areas or the ocean. Without a crew compartment, these planes won't need to be pressurized for human occupants.

"They are inherently more green," Randall said. "They use less gas, have less weight and overall less waste."

Hybrid Panthers Helping Rare Cat Rebound in Florida

A researcher holds three Florida panther kittens in Everglades National Park in June 2006.

Breeding rare Florida panthers with Texas cougars created tough hybrids that one scientist calls the Arnold Schwarzeneggers of cougars.

And, like action heroes, these vigorous offspring may well rescue the Florida subspecies from extinction, according to Stephen O'Brien, an animal geneticist who co-authored new research on the North American big cat.

Florida panthers are considered a subspecies of cougar, big cats found across the Americas that are also called pumas or mountain lions, depending on the region.

In the 1900s people hunted the Florida panther out of most of its southeastern U.S. range, driving the few remaining animals into rugged South Florida swamps.

Inbreeding within this tiny population caused heart problems and reproductive defects that would have killed off the Florida panther—deemed endangered by the U.S. Fish and Wildlife Service—by the early 21st century.

As a last-ditch effort, in 1995 the U.S. government released eight female cougars from a wild Texas population into Florida.

This cougar infusion increased the number of Florida panthers threefold, to about a hundred, said O'Brien, chief of the Laboratory of Genomic Diversity at the National Cancer Institute in Frederick, Maryland.

In addition, the offspring produced were genetically diverse animals that were stronger and lived longer, the 30-year study revealed.

Texas Cougars Shuffled Genetic Deck

Since the early 1980s, O'Brien and colleagues have closely monitored several Florida panthers via radio transmitters and microchips, occasionally anesthetizing animals to take blood samples. Those samples revealed a "marked increase" in DNA diversity after the Texan animals were introduced.

The team also measured survival rates of kitten litters and adult cats.
For instance, 23 out of 29 Florida panthers surveyed that were older than a year died between 2002 and 2004, compared with just 22 out of 47 hybrids, according to the study, published today in the journal Science.

The scientists also measured the animals' fitness, or ability to survive. One unusual measure of fitness, O'Brien noted, involved recording how a cougar reacted when the animal attempted to escape scientists' capture by climbing up a tree.

Most Florida panthers would cower in the tree. But trapped hybrids were more than twice as likely than Florida panthers to leap out of the tree and sail over the scientists' heads to safety, he said.

"Virtually every measure," he said, "showed the animals that had the mixed ancestry did better."

In a sense, releasing the Texan cougars restored the genetic flow that humans had interrupted, O'Brien added. In the 19th century, Florida panthers would sometimes mate with western cougars, naturally "shuffling the deck" genetically, he said.

"We don't feel like we've fiddled so much with nature, like making a hybrid between a lion and a tiger."

Florida Panthers Not Out of the Woods

In general, the research shows that bringing in new genes to aid a failing population "can be deliriously successful," O'Brien said.

"It's really not rocket science—if you have enough habitat and don't inbreed much, millions of years of evolution have given these species what it takes to survive and to prosper."

Even so, conservationists can't yet say hasta la vista to the Florida panther's problems.

"It was a very bold experiment and it has clearly paid off," said Elizabeth Fleming, Florida representative for the nonprofit Defenders of Wildlife.

But "now is the biggest challenge of all: We need to conserve existing habitat for these animals, as well as allow them to expand into some areas of their former range."

A hundred animals do not make up a truly viable population—for the subspecies to make it, their range needs to be expanded into other parts of Florida, Fleming said.

To that end, her organization is working with landowners to buy conservation easements, which would allow the predators to move onto land dedicated solely as wildlife habitat.

Meanwhile, some male Florida panthers are already striking out into new territory themselves, Fleming noted. (See "Cougar Reports on the Rise in Eastern U.S.")

"One made it all the way to Georgia," she said, "only to be shot by a deer hunter."

Original Models: A Look at Iconic Tech Prototypes

Super Soaker

If necessity is the mother of invention, trial and error is the father. In these prototypes of now-iconic products, you can still glimpse the sweat and ingenuity it took to bring them to life.

Lonnie Johnson was trying to build a better refrigerator, based on a low-cost heat pump that circulated water instead of Freon. But when one of his custom-machined brass nozzles blasted a stream of water across his bathroom, Johnson—by day an engineer at NASA’s Jet Propulsion Laboratory—realized he had the makings of something way more fun. A shotgun-style air pump and a series of check valves allowed for sniperlike range and accuracy with little exertion. Selling the idea to toy companies, though, was more of an effort. After seven years of frustration, Johnson scrapped his difficult-to-manufacture Plexiglas “pressure containment vessel” for an empty 2-liter soda bottle. It wasn’t slick, but it was easy to make. In 1990, the toy maker Larami brought the Power Drencher to store shelves; it sold roughly 2 million of them in the first year alone. Rebranded as the Super Soaker, the line has raked in sales of more than $200 million to date.

Push-Button Telephone
Dialing an old rotary phone was a laborious, time-intensive task: Your house could burn down before you finished cranking out the number for the fire department. In the late 1940s, switchboard operators already had a more efficient push-button setup that used tones instead of electrical pulses to signal each digit. So Bell Labs engineers set out to adapt that system for customers. Gutting a Western Electric 302 tabletop rotary, they installed a set of ten 3-inch metal reeds. Pressing a button plucked a specific reed, producing a unique sound. Thirty-five test units were deployed to phone company employees’ homes in Media, Pennsylvania, but the yearlong trial was a bust. Moving or bumping the phone warped the reeds, and any static on the line—or even talking—while dialing caused interference. Push-button phones didn’t become consumer-ready until 1963, when solid-state electronics replaced the reeds, generating foolproof digital tones.

Apple I

A 25-year-old engineer at Hewlett-Packard, Steve Wozniak was using his spare time to design a language interpreter for a new 8-bit microprocessor called the MOS 6502. But even though the motherboard he created was smaller and less complex than other kits on the market, and even though Wozniak gave away the schematics for free, hobbyists still found the board difficult to build. So Woz and his high school pal Steve Jobs, who was working at Atari, decided to sell preassembled boards—which they dubbed the Apple I. They built them at night in Jobs’ parents’ garage, paying Jobs’ sister $1 a board to insert chips. In 1976, they produced 200 units and sold 150 of them for $500 apiece, a tidy 100 percent markup over cost. The only drawback to the Apple I: It offered dynamic RAM but no permanent storage, so you had to plug in your own cassette drive to save anything.

Motorola DynaTAC

Martin Cooper built the world’s first cell phone in just 90 days. “All of the necessary technology existed in one place or another in our research labs,” says Cooper, a VP who oversaw development of Motorola’s Dynamic Adaptive Total Area Coverage handset. “But when you see the stuff we jammed into this unit, you marvel that they ever made it work.” Without large-scale integrated circuits, engineers had to stuff thousands of resistors, capacitors, inductors, and ceramic filters into a 4.4-pound package. The biggest challenge was a device Motorola researchers had invented called a triselector, which enabled simultaneous talking and listening. All mobile devices until then were press-to-talk walkies. Unfortunately, the triselector was as big as a double cheeseburger; Cooper and his team managed to scale it down to a 10th of that size. After erecting a 900-MHz base station in Manhattan, Cooper stood on Sixth Avenue and successfully called—where else?—Bell Labs.

Ancient Egypt's Pyramids: Norwegian Researcher Unlocks Construction Secrets

Scientists from around the world have tried to understand how the Egyptians erected their giant pyramids. Now, an architect and researcher at the Norwegian University of Science and Technology (NTNU) says he has the answer to this ancient, unsolved puzzle.
Researchers have been so preoccupied by the weight of the stones that they tend to overlook two major problems: How did the Egyptians know exactly where to put the enormously heavy building blocks? And how was the master architect able to communicate detailed, highly precise plans to a workforce of 10,000 illiterate men?

A 7-million-ton structure

These were among the questions that confronted Ole J. Bryn, an architect and associate professor in NTNU's Faculty of Architecture and Fine Art when he began examining Khufu's Great Pyramid in Giza. Khufu's pyramid, better known as the Pyramid of Cheops, consists of 2.3 million limestone blocks weighing roughly 7 million tons. At 146.6 meters high, it held the record as the tallest structure ever built for nearly 4000 years.

What Bryn discovered was quite simple. He believes that the Egyptians invented the modern building grid, by separating the structure's measuring system from the physical building itself, thus introducing tolerance, as it is called in today's engineering and architectural professions.

The apex point a key

Bryn has studied the plans from the thirty oldest Egyptian pyramids, and discovered a precision system that made it possible for the Egyptians to reach the pyramid's last and highest point, the apex point, with an impressive degree of accuracy. By exploring and making a plan of the pyramid it is possible to prepare modern project documentation of not just one, but all pyramids from any given period.

As long as the architect knows the main dimensions of a pyramid, he can project the building as he would have done it with a modern building, but with building methods and measurements known from the ancient Egypt, Bryn says.

In a scientific article published May 2010 in the Nordic Journal of Architectural Research, Bryn discusses aspects that can explain the construction of a multitude of the Egyptian pyramids by taking the building grid, and not the physical building itself, as the starting point for the analysis.

A new map

If the principles behind Bryn's drawings are correct, then archaeologists will have a new "map" that demonstrates that the pyramids are not a "bunch of heavy rocks with unknown structures" but, rather, incredibly precise structures.

Ole J. Bryn's findings will be presented and explained at the exhibition The Apex Point in Trondheim from September 13th to October 1st. The exhibition is an official part of the program to celebrate the centenary (1910-2010) of the Norwegian University of Science and Technology.

Cassini Makes First Dive Inside Saturn’s Radio Aurora

The Cassini spacecraft has made the first observations from within the radio aurora of another planet than Earth. The measurements, which were taken when the spacecraft flew through an active auroral region in 2008, show some similarities and some contrasts between the radio auroral emissions generated at Saturn and those at Earth. Results were presented this week by Dr Laurent Lamy at the European Planetary Science Congress in Rome, and recently published in Geophysical Research Letters.
"So far, this is a unique event," said Lamy (Observatoire de Paris, France). "Whereas the source region of Earth's radio aurora has been studied by many missions, this is our first opportunity to observe the equivalent region at Saturn from the inside. From this single encounter, we have been able to build up a detailed snapshot of auroral activity using three of Cassini's instruments. This gives us a fascinating insight into the processes that are generating Saturn's radio aurora."

Cassini encountered the auroral region at a distance of 247 million kilometres from Saturn's cloud tops (about 4 times Saturn's radius). High above the spectacular visible-light displays of Saturn's Northern and Southern Lights, auroral emissions occur this far from the planet at radio wavelengths. The emissions are generated by fast moving electrons spiralling along Saturn's magnetic field lines, which are threaded through the auroral region.

On 17 October 2008, Cassini's MAG (magnetometer), RPWS (radio) and CAPS (electrons) instruments detected three successive curtains of active auroras. An international team of scientists has now combined magnetic, radio and particle in situ observations to build up a picture of the local radio source properties and the surrounding auroral plasma. They also identified the magnetic field lines along which radio aurora are emitted.

"The instrument that measures radio waves, RPWS, can tell us the direction that each radio wave detected is travelling. By mapping this information onto magnetic field lines, we can work out the location of each radio source. In addition, we can project the source locations along the field lines that curve down to Saturn's southern pole and visualise a radio oval comparable to the auroral features commonly seen at ultraviolet wavelengths. Unusually, the oval observed during this event is strongly distorted, which indicates a particularly enhanced auroral activity," said Lamy.

Earth also has radio auroral emissions and these new results show that the process that generates radio aurora appears to be the same at both planets. Interestingly, there are two minor differences between the aurora at Earth and Saturn. At Earth, there is a cavity in the plasma above the auroral oval that rises for several thousand kilometres. The new observations show that this is not seen at Saturn. Secondly, radio sources were crossed at much further distances from the planet. These discrepancies reflect intrinsic differences between the two magnetospheres, in terms of dimensions and planetary rotation speed.

Cassini crossed high latitude auroral field lines during 40 orbits in 2008, but this is the only time that the instruments detected unusually strong electric currents in that region in space with in situ evidence of an active aurora.

"We think that the unusual conditions responsible for these intense electric currents might have been triggered by a solar wind compression squeezing Saturn's magnetic field and producing the observed auroras," said Emma Bunce, a team member from the University of Leicester in the UK.

Animation: Visualisation of the sources of a radio aurora at Saturn. The animation is based on Cassini observations using the RPWS instrument. On the left hand side are the radio sources as seen from Cassini. The right hand side shows the projection of the radio sources down onto the southern pole of the planet.

Dust Models Paint Alien's View of the Solar System

New supercomputer simulations tracking the interactions of thousands of dust grains show what the solar system might look like to alien astronomers searching for planets. The models also provide a glimpse of how this view might have changed as our planetary system matured.
See Also:
Space & Time

* Solar System
* Sun
* Solar Flare
* Pluto
* Kuiper Belt
* Nebulae


* Asteroid belt
* Neptune's natural satellites
* Near-Earth asteroid
* Gas giant

"The planets may be too dim to detect directly, but aliens studying the solar system could easily determine the presence of Neptune -- its gravity carves a little gap in the dust," said Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md. who led the study. "We're hoping our models will help us spot Neptune-sized worlds around other stars."

The dust originates in the Kuiper Belt, a cold-storage zone beyond Neptune where millions of icy bodies -- including Pluto -- orbit the sun. Scientists believe the region is an older, leaner version of the debris disks they've seen around stars like Vega and Fomalhaut.

"Our new simulations also allow us to see how dust from the Kuiper Belt might have looked when the solar system was much younger," said Christopher Stark, who worked with Kuchner at NASA Goddard and is now at the Carnegie Institution for Science in Washington, D.C. "In effect, we can go back in time and see how the distant view of the solar system may have changed."

Kuiper Belt objects occasionally crash into each other, and this relentless bump-and-grind produces a flurry of icy grains. But tracking how this dust travels through the solar system isn't easy because small particles are subject to a variety of forces in addition to the gravitational pull of the sun and planets.

The grains are affected by the solar wind, which works to bring dust closer to the sun, and sunlight, which can either pull dust inward or push it outward. Exactly what happens depends on the size of the grain.

The particles also run into each other, and these collisions can destroy the fragile grains. A paper on the new models, which are the first to include collisions among grains, appeared in the Sept. 7 edition of The Astronomical Journal.

"People felt that the collision calculation couldn't be done because there are just too many of these tiny grains too keep track of," Kuchner said. "We found a way to do it, and that has opened up a whole new landscape."

With the help of NASA's Discover supercomputer, the researchers kept tabs on 75,000 dust particles as they interacted with the outer planets, sunlight, the solar wind -- and each other.

The size of the model dust ranged from about the width of a needle's eye (0.05 inch or 1.2 millimeters) to more than a thousand times smaller, similar in size to the particles in smoke. During the simulation, the grains were placed into one of three types of orbits found in today's Kuiper Belt at a rate based on current ideas of how quickly dust is produced.

From the resulting data, the researchers created synthetic images representing infrared views of the solar system seen from afar.

Through gravitational effects called resonances, Neptune wrangles nearby particles into preferred orbits. This is what creates the clear zone near the planet as well as dust enhancements that precede and follow it around the sun.

"One thing we've learned is that, even in the present-day solar system, collisions play an important role in the Kuiper Belt's structure," Stark explained. That's because collisions tend to destroy large particles before they can drift too far from where they're made. This results in a relatively dense dust ring that straddles Neptune's orbit.

To get a sense of what younger, heftier versions of the Kuiper Belt might have looked like, the team sped up the dust production rate. In the past, the Kuiper Belt contained many more objects that crashed together more frequently, generating dust at a faster pace. With more dust particles came more frequent grain collisions.

Using separate models that employed progressively higher collision rates, the team produced images roughly corresponding to dust generation that was 10, 100 and 1,000 times more intense than in the original model. The scientists estimate the increased dust reflects conditions when the Kuiper Belt was, respectively, 700 million, 100 million and 15 million years old.

"We were just astounded by what we saw," Kuchner said.

As collisions become increasingly important, the likelihood that large dust grains will survive to drift out of the Kuiper Belt drops sharply. Stepping back through time, today's broad dusty disk collapses into a dense, bright ring that bears more than a passing resemblance to rings seen around other stars, especially Fomalhaut.

"The amazing thing is that we've already seen these narrow rings around other stars," Stark said. "One of our next steps will be to simulate the debris disks around Fomalhaut and other stars to see what the dust distribution tells us about the presence of planets."

The researchers also plan to develop a more complete picture of the solar system's dusty disk by modeling additional sources closer to the sun, including the main asteroid belt and the thousands of so-called Trojan asteroids corralled by Jupiter's gravity.

The Joy of Sets: For Ants and Trees, Multiple Partners Are a Boon

In the complex world of ant-plant partnerships, serial monogamy can help trees maximize their evolutionary fitness, a new University of Florida study shows.
Trees that sequentially partner with multi-species sets of ants produce more offspring than trees that maintain a lifelong association with any single ant -- even when those sets include ant species that appear to harm the tree, said Todd Palmer, a UF biology professor.

The study has broad implications because many of the world's ecosystems rely on cooperative partnerships between species, Palmer said.

"When you snorkel on a coral reef, you're hovering over an animal -- the coral -- that relies heavily on the algae it cooperates with for photosynthesis, just as when you eat an apple, you're reaping the benefits of a tree that was pollinated by an insect," he said.

According to Palmer, many prior studies of cooperation in nature, or mutualism, have focused on the "cheater problem": How can cooperation persist when both sides have an incentive to reap benefits without contributing to the common good? Ecological studies tend to be short-term, with species labeled as "cooperators" or "freeloaders," depending on cost-benefit ratios calculated over just a few years.

Palmer and his team took a different approach, looking at a common African tree and its relationships with four specialized ant partners over the tree's lifetime.

The surprising finding was that the tree in Kenya did best when occupied by all four ant species over its lifetime, even though one ant species joined forces with beetles in ways that increased tree death rates; another sterilized the tree; and a third was so scared of the other three competing ant species that it didn't do much of anything, said Palmer, whose paper is published this week online in Proceedings of the National Academy of Sciences.

"Looking at the costs and benefits to the tree, not just at a single moment, but in terms of number of offspring produced over a lifetime, the best possible outcome is obtained not by having what we thought was the "good mutualist," but rather by having all four ant species at different life stages -- even the so-called parasite, cheater, freeloader scumbag ants," he said.

In the past, only one of the four ant species was recognized as a cooperator, because it successfully defended the tree from elephants and other herbivores in exchange for using the tree's resources, Palmer said. The other three ants were thought to exhibit varying degrees of cheating behavior, he said.

The key to the new findings is the timing. When a species lives a long time, its needs may change drastically as it grows from young to old, and sequential associations with several partners may help it meet those needs at different times, he said.

"A human analogy might be that what we look for in romantic partnerships when we're younger -- perhaps a daring and exciting person who likes to be bold and take risks -- is not necessarily the thing that we are looking for in a romantic partner when we get older, when stability, the ability to hold down a job and provide for children becomes more important," he said. "The best possible partner is really a function of where you are in your life and what your needs are at that particular moment."

In the same way, a mutualistic species may require a partner that helps it survive during its vulnerable younger years, even if that partner prevents it from reproducing, Palmer said. Later in life, when large size makes individuals less vulnerable, the ideal partner may be one that enhances reproduction even as it reduces the chances of longer-term survival, he said.

Over eight years, Palmer and colleagues monitored annual survival, growth, reproduction and ant occupancy of 1,750 Acacia drepanolobium trees and constructed demographic models that related the trees' lifetime fitness to occupation by different combinations of the four ant partners. The ostensible freeloaders turned out to be more than they seemed, he said.

The ant that conspires with a wood-boring beetle that can kill trees? It turns out that before it kills them, it causes them to produce an inordinate number of seeds, Palmer said. Likewise, the ant that castrates the tree is actually an aggressive defender, so while the tree doesn't reproduce for many years, it is likely to survive to produce fruit more down the road after the castrator is evicted by another ant species.

And the ant that appeared to be a do-nothing actually does just enough, Palmer said. "It defends trees a little bit, but unlike the other ant species, it is very faithful and hardly ever abandons the tree," he said. "And having any ant at all is very much better than having no ant, because if you have no ants, you get hammered by everything from caterpillars to elephants."

Magnetic Anomalies: New Type of Solar Wind Interaction With Airless Bodies in Our Solar System

Scientists have discovered a new type of solar wind interaction with airless bodies in our solar system. Magnetized regions called magnetic anomalies, mostly on the far side of the Moon, were found to strongly deflect the solar wind, shielding the Moon's surface. This will help scientists understand the solar wind behaviour near the lunar surface and how water may be generated in its upper layer.
Observational evidence for these findings is being presented by Drs. Yoshifumi Futaana and Martin Wieser at the European Planetary Science Congress in Rome.

Atmosphere-less bodies interact with the solar wind quite differently than the Earth: Their surfaces are exposed without any shielding by a dense atmosphere or magnetosphere. This causes them to be heavily weathered by meteoroids or the solar wind, forming a very rough and chaotic surface called regolith. So far, the solar wind was thought to be completely absorbed by regolith. However, recent explorations of the Earth's moon by the Chang'E-1, Kaguya and Chandrayaan-1 spacecrafts have revealed that this interaction is not that simple.

A significant flux of high energy particles were found to originate from the lunar surface, most probably due to the solar wind directly reflected off the Moon's regolith. "These results may change dramatically the way we understood the solar wind-regolith interaction so far. Since the solar wind is one potential source of water on the Moon, we need to make better models of the lunar hydrogen circulation in order to understand how water molecules form in its upper layers," says Dr. Futaana of the Swedish Institute of Space Physics. "Also, it will be possible to remotely investigate the solar wind-surface interaction on other airless bodies, such as the Martian moon Phobos or Mercury, by imaging the energetic hydrogen atoms that are reflected back to space when solar wind hits their surface," he adds.

The current investigation was carried out with the Sub-keV Atom Reflecting Analyzer instrument which was developed in a collaboration between Sweden, India, Switzerland and Japan and flown onboard the Indian Chandrayaan-1 spacecraft. Scientists have mapped for the first time the energetic hydrogen atoms coming from the Moon, and found that up to one fifth of the solar wind protons reaching the lunar surface are reflected back to space.

This may be a general feature of the atmosphere-less bodies, such as Mercury, meteorites and several moons of the giant planets. "In fact, during the close encounter of the European Mars Express spacecraft with Phobos in 2008, we detected signatures of reflected solar wind protons also from the surface of Martian moon Phobos," says Dr. Futaana.

However, when Chandrayaan-1 flew over a magnetic anomaly (magnetized region on the Moon surface), the scientists detected significantly less reflected hydrogen atoms meaning that the solar wind had not reached the lunar surface. In fact, the solar wind was found to be strongly deflected by an aggregation of magnetic anomalies in the southern hemisphere of the lunar far side. "We detected a strong flux of deflected solar wind protons. This clearly indicates that magnetic anomalies can shield the lunar surface from the incoming solar wind, in the same way as the magnetospheres of several planets in our solar system," says Dr. Futaana.

"It all depends on how strong the solar wind "blows." When the solar wind pressure is low, this "mini-magnetosphere" expands causing stronger shielding," concludes Dr. Wieser, also of the Swedish Institute of Space Physics.

How Molecules Escape from Cell's Nucleus: Key Advance in Using Microscopy to Reveal Secrets of Living Cells

By constructing a microscope apparatus that achieves resolution never before possible in living cells, researchers at Albert Einstein College of Medicine of Yeshiva University have illuminated the molecular interactions that occur during one of the most important "trips" in all of biology: the journey of individual messenger Ribonucleic acid (RNA) molecules from the nucleus into the cytoplasm (the area between the nucleus and cell membrane) so that proteins can be made.
The results, published in the September 15 online edition of Nature, mark a major advance in the use of microscopes for scientific investigation (microscopy). The findings could lead to treatments for disorders such as myotonic dystrophy in which messenger RNA gets stuck inside the nucleus of cells.

Robert Singer, Ph.D., professor and co-chair of anatomy and structural biology, professor of cell biology and neuroscience and co-director of the Gruss-Lipper Biophotonics Center at Einstein, is the study's senior author. His co-author, David Grünwald, is at the Kavli Institute of Nanoscience at Delft University of Technology, The Netherlands. Prior to their work, the limit of microscopy resolution was 200 nanometers (billionths of a meter), meaning that molecules closer than that could not be distinguished as separate entities in living cells. In this paper, the researchers improved that resolution limit by 10 fold, successfully differentiating molecules only 20 nanometers apart.

Protein synthesis is arguably the most important of all cellular processes. The instructions for making proteins are encoded in the Deoxyribonucleic acid (DNA) of genes, which reside on chromosomes in the nucleus of a cell. In protein synthesis, DNA instructions of a gene are transcribed, or copied, onto messenger RNA; these molecules of messenger RNA must then travel out of the nucleus and into the cytoplasm, where amino acids are linked together to form the specified proteins.

Molecules shuttling between the nucleus and cytoplasm are known to pass through protein complexes called nuclear pores. After tagging messenger RNA molecules with a yellow fluorescent protein (which appears green in the accompanying image) and tagging the nuclear pore with a red fluorescent protein, the researchers used high-speed cameras to film messenger RNA molecules as they traveled across the pores. The Nature paper reveals the dynamic and surprising mechanism by which nuclear pores "translocate" messenger RNA molecules from the nucleus into the cytoplasm: this is the first time their pore transport has been seen in living cells in real time.

"Up until now, we'd really had no idea how messenger RNA travels through nuclear pores," said Dr. Singer. "Researchers intuitively thought that the squeezing of these molecules through a narrow channel such as the nuclear pore would be the slow part of the translocation process. But to our surprise, we observed that messenger RNA molecules pass rapidly through the nuclear pores, and that the slow events were docking on the nuclear side and then waiting for release into the cytoplasm."

More specifically, Dr. Singer found that single messenger RNA molecules arrive at the nuclear pore and wait for 80 milliseconds (80 thousandths of a second) to enter; they then pass through the pore breathtakingly fast -- in just 5 milliseconds; finally, the molecules wait on the other side of the pore for another 80 milliseconds before being released into the cytoplasm.

The waiting periods observed in this study, and the observation that 10 percent of messenger RNA molecules sit for seconds at nuclear pores without gaining entry, suggest that messenger RNA could be screened for quality at this point.

"Researchers have speculated that messenger RNA molecules that are defective in some way, perhaps because the genes they're derived from are mutated, may be inspected and destroyed before getting into the cytoplasm or a short time later, and the question has been, 'Where might that surveillance be happening?'," said Dr. Singer. "So we're wondering if those messenger RNA molecules that couldn't get through the nuclear pores were subjected to a quality control mechanism that didn't give them a clean bill of health for entry."

In previous research, Dr. Singer studied myotonic dystrophy, a severe inherited disorder marked by wasting of the muscles and caused by a mutation involving repeated DNA sequences of three nucleotides. Dr. Singer found that in the cells of people with myotonic dystrophy, messenger RNA gets stuck in the nucleus and can't enter the cytoplasm. "By understanding how messenger RNA exits the nucleus, we may be able to develop treatments for myotonic dystrophy and other disorders in which messenger RNA transport is blocked," he said.

The paper, "In Vivo Imaging of Labelled Endogenous β-actin mRNA during Nucleocytoplasmic Transport," was published in the September 15 online edition of Nature.

Mystery of Disappearing Martian Carbon Dioxide Ice Solved?

Scientists may have solved the mystery of the carbon dioxide ice disappearance early in the Northern Martian springs followed later by its sudden reappearance, revealing a very active water cycle on the planet. Dr. Bernard Schmitt and Mr. Thomas Appéré are reporting their results about water ice mobility during Martian Year 28, at the European Planetary Science Congress in Rome.
Seasonal ice deposits are one of the most important Martian meteorological processes, playing a major role in the water cycle of the planet. Every Martian year, alternatively during northern and southern winter, a significant part of the atmosphere condenses on the surface in the form of frost and snow. These seasonal ice deposits, which can be up to one meter thick, are mainly composed of carbon dioxide with minor amounts of water and dust. During spring, the deposits sublimate (vaporize), becoming a substantial source of water vapour, in particular in the northern hemisphere of the planet.

Dr. Schmitt and his colleagues Thomas Appéré and Dr. Sylvain Douté at the Laboratoire de Planétologie de Grenoble, France, have analyzed data taken with the OMEGA instrument on board Mars Express, for two northern Martian regions. Before the Mars Express mission (ESA), the evolution of the seasonal deposits has been monitored by the albedo (reflectivity) and temperature changes of the surface, as the ice deposits appear much brighter and are colder than the surrounding defrosted terrains."But we couldn't resolve their exact composition and how they were distributed on the planet. Near-infrared observations, such as the OMEGA data, are much better for detecting strong signatures of water and carbon dioxide ice," says Mr Appéré.

The first Martian region that the scientists observed is located on Gemina Lingula, a Northern plateau, where peculiar evolution of the carbon dioxide ice deposits was observed. "During spring the ice signature disappeared from our data, but the surface temperature was still cold enough to sustain plenty of CO2 ice. We concluded that a thick layer of something else, either dust or water ice was overlaid. If it was dust then it would also hide water ice and the surface of the planet would become darker. None of these happened so we concluded that a layer of water ice was hiding the CO2 ice. We had to wait until the weather gets warm enough on Mars for the water to vaporize as well, and then the carbon dioxide signatures re-appeared in our data," explains Dr Schmitt.

But where does this layer of water ice come from? Soon after spring sunrise, the solar radiation hitting the surface of Mars warms enough the CO2 ice lying on the top layer to cause it to vaporize. But the water ice needs higher temperatures to sublimate, so a fine grained layer of water ice gradually forms hiding the carbon dioxide ice still lying beneath it. "A layer only 2 tenths of a millimetre thick is enough to completely hide the CO2 ice. Also some water that has been vaporized at lower, warmer, Martian latitudes condenses as it moves northward and may be cold trapped on top of the CO2 ice," says Mr. Appéré.

The second region analysed by the team is located in the spiral troughs structure of the North permanent cap. A similar situation was observed but the carbon dioxide ice re-appeard very quickly here after its initial disappearance. "This hide-and-seek game didn't make much sense to us. It wasn't cold enough for CO2 ice to condense again, neither warm enough for water ice to sublimate," explains Dr. Schmitt. "We concluded that somehow the water ice layer was removed. The topography of the North permanent Martian cap is well-suited to entail the formation of strong katabatic (downhill) winds. Aymeric Spiga used a model from the Laboratoire de Météorologie Dynamique du CNRS to simulate those winds and he indeed confirmed the sudden re-appearances of CO2 ice where strong katabatic winds blow," says Mr. Appéré.

Dr. Schmitt concludes: "To decipher the present and past water cycles on Mars and improve our weather models on the planet one needs to have a good understanding of the seasonal ice deposits dynamics, how they change in space and time. We are confident that our results will make a significant contribution in this direction."

Pinpointing Where Volcanic Eruptions Could Strike

A better way to pinpoint where volcanic eruptions are likely to occur has been produced by an international team of geophysicists.
Scientists from the universities of Leeds, Purdue, Indiana and Addis Ababa, investigated volcanic activity occurring in the remote Afar desert of Northern Ethiopia between 2005 and 2009.

By studying a rare sequence of 13 magmatic events -- where hot molten rock was intruded into a crack between the African and Arabian plates -- they found that the location of each intrusion was not random. They showed that they were linked because each event changed the amount of tension in the earth's crust.

The findings, published in Nature Geoscience, will help scientists to more accurately predict where volcanic eruptions could strike and contribute to efforts to limit the damage they can cause.

Lead author Dr Ian Hamling, who completed the analysis as part of his PhD in the School of Earth and Environment at the University of Leeds said: "It's been known for some time that a large earthquake has a role to play in triggering subsequent earthquakes, but until now, our knowledge of volcanic events has been based on isolated cases. We have demonstrated that volcanic eruptions can influence each other. This will help us predict where future volcanic eruptions are likely to happen."

The team studied the region around a large volcanic dyke -- a vertical crack which is created when Magma seeps from underground through rifts in the surface of the earth -- which erupted in the Afar desert in September 2005.

he Magma -- hot molten rock -- was injected along the dyke between depths of 2 and 9 km, and altered the tension of the earth. The team was able to watch the 12 smaller dykes that subsequently took place in the same region over a four year period.

By monitoring levels of tension in the ground near where each dyke was intruded they found that subsequent eruptions were more likely in places where the tension increases.

Dr Hamling said: "If you look at this year's eruptions at Ejafjallajokull in Iceland, by estimating the tension in the crust at other volcanoes nearby, you could estimate whether the likelihood of them eruption has increased or decreased. Knowing the state of stress in this way won't tell you when an eruption will happen, but it will give a better idea of where it is most likely to occur."

viernes, 24 de septiembre de 2010

Clues to Child Sacrifices Found in Inca Building

* The remains of seven children killed as religious sacrifices are offering clues to the grim ceremony.
* The children, ranging in age from 3 to 12 years, were found beneath a 500-600-year-old building in Peru.
* Analysis suggests that the sacrificed children were taken from distant parts of the Inca realm.

An ancient Inca ground overlooking Cuzco, Peru. The remains of seven children buried beneath a 600-year-old building in Cuzco Valley are offering clues to child sacrifice ceremonies.

The remains of seven children apparently killed in a ritual and buried beneath a 500- to 600-year-old building in Peru's Cuzco Valley have given scientists new glimpses of the sketchily understood Inca practice of sacrificing select children in elaborate ceremonies.

The children were buried at the same time, apparently after having been killed in a sacrificial rite that honored Inca deities and promoted political unity across the far-flung empire, say anthropologist Valerie Andrushko of Southern Connecticut State University in New Haven and her colleagues.

Chemical analyses of the bones indicate that at least two of the children came from distant parts of the Inca realm, Andrushko's group reports in a paper published online Sept. 15 in the Journal of Archaeological Science.

Archaeological evidence of Inca child sacrifices has come mainly from youngsters' naturally mummified bodies found frozen on several Andean peaks. Human figurines and other valuable objects lay near those bodies.

"It was surprising that figurines and other artifacts found with children buried at this low-altitude site are nearly identical to finds at high-altitude child sacrifices," Andrushko says.

Items surrounding the remains of six youngsters buried together in the Inca structure included gold and silver female figurines, red shell figurines of females and llamas, fancy pottery and a piece of clothing covered in gilded metal discs.

An additional child interred about 3 meters from the others lay near a silver figurine of a man adorned with a shell headdress and cloth fragments. Miniature gold, silver and shell figurines of men and llamas surrounded the larger figurine.

Accounts of Inca life written by Spanish conquerors described a ritual in which children from throughout the kingdom were selected for sacrifice based on their physical perfection. Those chosen were brought to the capital city of Cuzco for special ceremonies and then escorted to sometimes distant sacrificial sites.

In a 2007 study, isotopic analyses of hair samples from four Inca youths found more than a decade ago on two Andes summits indicated that they had eaten increasing amounts of maize for about four months before death, apparently at mountain way stations.

Such investigations are rare, remarks anthropologist Tamara Bray of Wayne State University in Detroit. "We have so little scientific information about who these children were or where they may have come from," she says.

The new report focuses on an apparent child sacrifice discovered during a 2004 dig directed by study coauthors Arminda Gibaja of the National Institute of Culture in Cuzco, Peru, and Gordon McEwan of Wagner College in Staten Island, N.Y. Excavations took place at an Inca site called Choquepukio, located about 30 kilometers east of the Inca capital.

Children buried in the Choquepukio building ranged in age from 3 to 12, based on their tooth development. Not enough skeletal material survived to make sex determinations. The researchers measured ratios of strontium isotopes in children's teeth to determine if they had grown up locally. Strontium isotopes get absorbed by teeth to varying extents during childhood depending on concentrations of different forms of strontium in local soils and water.

Comparisons to strontium signatures for Inca adults from the Cuzco region indicated that two children definitely had not been raised there. Preliminary strontium data from other Inca sites suggests that one child came from southern Peru and the other from northwestern Bolivia, Andrushko notes.

Further research is needed to establish whether residents of other parts of the Inca realm possessed a strontium signature like that of Cuzco-region natives, she adds.

Her team could not determine how the Choquepukio children died. Spanish accounts described strangulation of sacrificed youngsters. A neck bone called the hyoid often fractures when adults are strangled but rarely fractures in children because it hasn't fully formed.

Stuck in Space

A Russian Soyuz capsule that was to ferry three space station crewmembers back to Earth early Friday remained stuck in its berthing port, delaying the trio’s homecoming by at least a day.

Station commander Alexander Skvortsov and flight engineers Mikhail Kornienko and Tracy Caldwell Dyson planned to depart the outpost at 9:35 p.m. EDT Thursday, wrapping up a six-month mission. Three crewmates remained aboard the station and three new additions are due to arrive Oct. 9.

After resolving problems with airtight seals between the Soyuz spacecraft and the station’s Poisk docking module, Skvortsov sent commands for the Poisk’s latches and hooks to open. Nothing happened.

Russian flight controllers delayed the departure while they coached Skvortsov through a variety of trouble-shooting procedures, but the latches remained closed. Attempts to separate the capsule were called off at 12:15 a.m. EDT and the crew was told to head back into the station.

Engineers are reviewing photographs, video and instrument readings to try to resolve the problem, which is believed to be caused by an electrical short. The crew’s departure has been tentatively rescheduled for Friday night.

(Another day's stay for the returning Expedition 24 crew. Credit: NASA)

Mars Methane Mystery: What's Making the Gas?

* The first planet-wide studies of methane on Mars shows gas concentrations peak in autumn and plummet in winter.
* The methane could be produced by geologic or biological activity.
* The rapid removal of the chemical from the atmosphere is as much a mystery as what's producing it.

A six-year study of methane in Mars' atmosphere shows the planet is far from dead, though whether it is merely geologically active or host to microbial life is unknown.

An Italy-based team of researchers combed through billions of measurements taken by NASA's Mars Global Surveyor to compile seasonal maps of the gas, a simple chemical compound that appears in minute quantities in Mars' carbon dioxide-rich atmosphere.

Methane breaks down in ultraviolet light from the sun, so scientists know it is being replenished in some way from the planet itself. The speed at which the methane is being depleted -- less than a year -- is as great a mystery as what's causing it.

"We're trying to simulate what kind of mechanisms are possible and are active on Mars in order to see this behavior," Guiseppe Marzo, a researcher with ENEA, the Italian National Agency for New Technologies, Energy and Sustainable Economic Development, told Discovery News.

Marzo and colleagues found three regions in the planet's northern hemisphere with consistently higher concentrations of methane -- Tharsis, Elysium and Arabia Terrae. Tharsis and Elysium are home to Mars' most massive volcanoes and Arabia Terrae has large quantities of subterranean frozen water.

Methane concentrations are highest in autumn and tail off dramatically in winter. Levels build up again in spring and climb rapidly during summer, causing the gas to spread across the planet, the researchers found.

Lead researcher Sergio Fonti, with Italy's Universita del Salento, says the seasonal pattern rules out the possibility that the methane is due to cosmic ray bombardment or meteorite impacts.

"It could be geology or biology, but it is not coming from another source. There is a seasonal pattern, so it could only be a local origin," Fonti told Discovery News.

NASA and Europe are planning a joint mission in 2016 to make more detailed maps of Mars' methane. NASA's Mars Science Laboratory, scheduled for launch next year, also has an instrument that can detect atmospheric methane.

"The release appears to be episodic, so we need much more compete coverage of methane than what we can achieve on the ground," said NASA space scientist Michael Mumma, who last year published highly cited research on Mars' methane made from ground-based observatories.

On Earth, colonies of bacteria that consume methane have been found living right along species that produce it.

"We could easily have a similar situation on Mars," Mumma said.

Fonti and Marzo's research was presented this week at the European Planetary Science Congress in Rome. It will be published in an upcoming issue of Astronomy & Astrophysics.

New Magma Layer Found Deep in Earth's Mantle?

A layer of searing hot liquid magma trapped since Earth's formation may lie 1,800 miles (2,900 kilometers) beneath our feet, new research suggests.

The finding backs up theories that Earth's solid lower mantle once housed a magma "ocean," and that some remnant of that molten material still exists today, like jam between two cake layers.

"Some models consider the [early] Earth to have been completely or largely molten, and people are looking for possible remnants or relics of this molten state," said study co-author Guillaume Fiquet of the Institut de Minéralogie et de Physique des Milieux Condensés at France's Université Pierre et Marie Curie.

"Those models [suggest] that, as time passed and Earth solidified, some molten rock could have been trapped at the bottom of the mantle-core boundary."

In a new experiment, Fiquet and colleagues showed what would happen to minerals found in Earth's mantle if exposed to the unimaginable heat and pressure that exist at this boundary region.

Their findings not only affect theories for how Earth's insides are structured but also imply that some volcanoes might be spewing lava from magma plumes that brush against Earth's core.

Diamonds Help Re-create Deep Earth Conditions

Based on the rate at which seismic waves travel through Earth, scientists think our planet's core is made of a solid iron ball surrounded by a liquid iron shell. Above the core lie the solid lower mantle, upper mantle, and crust.

This liquid layer around the core meets Earth's lower mantle about 1,800 miles (2,900 kilometers) below the surface. Temperatures at the core-mantle boundary hover around 4,000 Kelvin (6,740 degrees F, or 3,727 degrees C), and the pressure is nearly 140 gigapascals—1.4 million times greater than standard air pressure at sea level.

Without a way to take direct samples from deep inside Earth, no one knows for sure if the mantle's boundary rocks are solid or liquid.

But scientists have long recorded dramatic drops in the speeds of seismic waves near the core-mantle boundary, leading some experts to speculate that this region is partially melted.

To simulate the extreme subterranean environment, Fiquet and colleagues put samples of typical mantle materials—magnesium oxides, iron, and silicon—into diamond anvil cells, small chambers in which microscopic samples get crushed between two diamonds.

The intense crushing heated the samples to temperatures greater than 5,000 Kelvin (8,540 degrees F, or 4,726 degrees C) and raised the pressure to 140 gigapascals. Using a technique called x-ray diffraction, the scientists then shone light on the minerals' atomic structures and saw when the material started to change from a solid to a liquid.

Mantle minerals started to melt at 4,200 Kelvin (7,100 degrees F, or 3,926 degrees C)—just about the temperature of the core-mantle boundary.

"Hot Spot" Volcanoes Fed by Ultradeep Magma?

Fiquet cautions against using the term "magma ocean" to describe the potentially melted layer deep inside Earth: "The basic thing to remember is that the mantle is solid rock, but it might also be partially molten at the base."

Still, the molten rock created during the experiment might hold chemical markers that could help researchers understand how Earth's molten material cooled and separated into layers over time, the study authors say.

The finding may also have ramifications for studies of volcanoes. Many volcanoes, such as those in the Pacific Ring of Fire, exist where tectonic plates meet, and the volcanoes are filled with magma generated by melting of the upper mantle.

But so-called hot spot volcanoes, such as Hawaii's, are thought to be fed by plumes of hot rock rising from deeper within Earth.

"I think the plumes could have their sources in very hot regions at the core-mantle boundary that might be partially molten," Fiquet said.

"But to make a strong link with the plumes and their associated volcanism, we'll next have to ... test all the individual components that are likely to be buried down at that core-mantle boundary."

miércoles, 22 de septiembre de 2010

King Herod's Palace Contained Luxury Theater Box: Big Pic

Sept. 22, 2010 -- Archaeologists have uncovered a 400-seat theater complete with a luxury box at King Herod's winter palace.

In this photo, we see remnants of the frescoes that originally adorned the complex around 15 B.C. The private box had been richly decorated with paintings and plaster moldings, which were created by Roman artists commissioned by Herod.Although the private box is a recent discovery, the theater was first excavated in 2008, discovered a short distance from Herod's mausoleum.

The Romans appointed Herod the king of Judea around 40 B.C. Under his rule, Herod expanded the Jewish second temple, known as the Temple Mount, and initiated public works projects.

Frilly-Horned Dino Found on 'Lost Continent'

* Two new species of dinosaurs are found in southern Utah where a long island once existed.
* One of the dinosaurs had a frill of horns along the top edge of its head and above its eyes.
* It's unusual that such a variety of large dinosaurs existed within such a small space at one time.

frilly dinosaur

A newly found dinosaur featured strangely folded frill of horns on the top edge of its head and the horns that stick out sideways from above the eyes.

Two spectacular new species of horned, triceratops-like dinosaurs have been found in southern Utah, report paleontologists. The ornately frilled rhino-sized dinos are more than just eye candy, however. They are deepening a mystery about a long lost island that supported a seemingly impossible number and variety of dinos at the same time.

The giant plant-eating Kosmoceratops richardsoni and Utahceratops gettyi were found in the Grand Staircase-Escalante National Monument in rocks that were once part of a long island called Laramidia, which was separated from the rest of North America by a wide, shallow, north-south running seaway.

"It's a freaky dinosaur," said Matthew Lamanna, assistant curator at the Carnegie Museum of Natural History, commenting on Kosmoceratops. "If it were made into a kid's toy, it'd be a very popular one."

Among the things that make Kosmoceratops stand out are the strangely folded frill of horns on the top edge of its head and the horns that stick out sideways from above the eyes -- more like a longhorn steer than a dinosaur. The scientists are quite sure that none of these and other unusual features are artifacts of burial or damage after death for one simple reason:

"We actually have more than one skull," said paleontologist Scott Sampson, research curator at the Utah Museum of Natural History and lead author of a paper describing the new dinosaurs in the journal PloS ONE. Sampson is better known to children as "Dr. Scott," the host of the PBS Kids program, "Dinosaur Train."

Over the last few decades discoveries of Laramidian dinosaurs from Alberta to New Mexico have been revealing an unusually large number of both individuals and species living within a short span of time and varying from north to south.

For many years it was primarily the remnants of the northern end of Laramidia, found in Alberta, Canada, which were yielding great numbers of new dinosaur species from the late Cretaceous. Now the discoveries in Utah are beginning to catch up by representing the southern end of Laramidia.

Researchers have been surprised to find that instead of one or two species of dinosaur reaching across a large land mass -- as is the case with large mammals today -- there appear to have been many kinds of horned dinosaurs sharing the island.

Just how such large animals managed this is unknown, said Sampson. One possibility is that they had slower metabolisms than comparably-sized mammals, and so needed less energy and less food and space, Sampson explained.

It might also be that dinosaurs were just more prolific than comparable large mammals of today, says paleontologist Thomas Holtz of the University of Maryland. Fossilized nests show that this sort of dinosaur could lay a dozen eggs every year. A comparable mammal might have a single offspring every year that may take a dozen years to mature.

"Dinosaurs seemed to be more like weeds than trees," said Holtz. It could also be that the land was more productive in the late Cretaceous and could support more animals, he said.

As for what the ornate horns of the new dinos were used for, that's unknown, but the best best is they were all about looks.

"It was initially thought that they must be used as weapons," said Sampson. "It's much more likely it was used for show" to attract mates and/or repel competitors.