- Giant Solar Blast Headed for Earth
- Video: Carnivorous Bladderworts Catch Meals With Vacuum Power
- Simple Seaweeds May Be Earth’s First Plants
- Gallery: Meet the Original Dogs
- ‘Wordquakes’ Can Shake the Political Blogosphere
- Adult Brain Activity Stirs Before Birth
Posted: 16 Feb 2011 02:13 PM PST
The biggest solar blast in four years erupted late Monday, and it's sending jets of charged particles right at Earth. The spray will spark bright auroras when it hits the magnetosphere in the next 24 to 48 hours.
A cluster of sunspots called Active Region 1158 unleashed the flare at 8:50 p.m. EST, Feb. 14 [1:50 a.m. UT, Feb. 15]. It was categorized as class X2.2, meaning it's the most powerful flare since December 2006. The sunspots have continued to let loose smaller flares and may still be active now.
As Spaceweather.com notes, the sunspots didn't even exist one week ago, and now cover a swatch of sun wider than Jupiter.
NOAA forecasters estimate a 45 percent chance of geomagnetic activity on Thursday, Feb. 17, when the bulk of the radiation hits Earth's magnetic field. The December 2006 storm was powerful enough to disrupt GPS systems.
Should the new storm prove as powerful, it could be a preview of what's expected this year and in 2012, as the sun reaches an expected maximum in its natural cycle of activity.
There is, however, a silver — and green, and yellow, and glowing — lining to the flares. In higher latitudes, where the sun's ion spray is pulled by Earth's magnetic poles, collisions between solar particles and atoms suspended in our magnetosphere produce photon sparks. Together these form the aurora borealis, or northern lights, and it looks like Earth is in for quite a show.
What's more, though a full moon often outshines the auroras, this storm may be so powerful as to mix moonlight and northern lights in one spectacular swirl. So look up! And if you take pictures, send us your best shots. If we get enough, we'll create a reader gallery.
A flare emerges from the sun in this ultraviolet-light image of the solar surface. (SDO/NASA)
Posted: 16 Feb 2011 01:30 PM PST
Carnivorous bladderworts trap prey with speed that would make a Bond villain shudder in gleeful envy.
Using high-speed cameras, researchers have gotten the first good look at how these underwater plants spring their ambushes. Bladderworts sport trap doors that buckle in with a tiny nudge, creating a whirlpool that sucks in wee critters — all in about half a millisecond. That's some of the fastest plant action on Earth, a French and German team reports online February 15 in the Proceedings of the Royal Society B.
Forget Venus flytraps. Bladderworts of the genus Utricularia are really cunning meat eaters. "Utricularia are the smallest of carnivorous plants and also, evidently, the most sophisticated," says Lubomír Adamec, a plant physiologist at the Academy of Sciences of the Czech Republic. These netlike veggies are dotted with tiny traps, often no wider than an ant is long.
Small or not, the traps are masterpieces of suction. Pumped nearly dry, the chambers set up a pressure difference between the plant's innards and the water outside. When swimmers brush up against a series of hairs along the trap door, the door bursts open and sucks water and crustaceans alike in.
Despite decades of interest in these nefarious plants, botanists couldn't say for sure how the traps worked. Bladderworts were just too quick for old-school cameras. But with fancy new high-speed cameras, biologists can get their close-ups, says Adamec.
It looks, at least in three bladderwort species, like the traps spring using an elastic buckle. At just the right pressure, the domelike trap door stays shut. But then, a tiny touch collapses the door like a popped bubblegum bubble, opening a small window to the trap below. But unlike a gum bubble, the doors are bouncy and spring back to their original shape in fractions of a second, says study coauthor Philippe Marmottant. "This kind of change of shape is very abrupt," says Marmottant, a physicist at Joseph Fourier University in Grenoble, France. The quick pop pulls water in with tiny swirls that move at speeds up to about 3 miles per hour.
Physicists had already predicted such a buckling trap in 2005, but this study gives a good look at it in action, says Victor Albert, a biologist at the University at Buffalo in New York. Carnivory isn't a trivial thing for these plants, either, he says. As meat eaters, these plants flourish in rough and strange habitats from swamps to the insides of bromeliads, bowl-shaped tropical plants. "They're just crazy," he says.
And maybe crazy useful, Marmottant says. As a physicist, he's less interested in ecology than in the flow of liquid in very tiny environments. And bladderworts move fluid so well, he says, they could inspire new lab tools like pipettes. These tools, which pick up and spit out tiny drops of liquid, are important in the biotech industry. "Bladderworts act like a small pipette," he says. "This could be used in miniature devices."
Still no word, however, on whether they can trap rakish British agents.
Video: Philippe Marmottant.
Image: Many a small crustacean met its end in this bladderwort trap, seen here in a close-up. Now, scientists have a much better idea about how these devious chambers work. (Carmen Weißkopf)
Posted: 16 Feb 2011 11:30 AM PST
A trove of seaweed-like fossils unearthed in southern China may be some of the oldest plants ever discovered.
Until now the earliest definitive evidence of complex creatures resembling modern organisms was about 580 million years old. A series of fossils described Feb. 16 in Nature predates those archetypal creatures by anywhere from 20 million to 56 million years.
"It's not the oldest multicellular life," said paleontologist Shuhai Xiao of Virginia Tech, a co-author of the study. "But it is a collection of the oldest diverse, complex and macroscopic multicellular life."
Bacteria emerged 3.4 billion years ago. About 2 billion years ago, some may have gone multicellular, though it's possible they were just ornate groups of single-celled organisms.
Whatever they were, they didn't have modern physical forms. Most researchers think those didn't evolve until at least 635 million years ago. That's when Earth began thawing from one of the most severe, glacier-covered "snowball" periods in history.
No longer trapped beneath ice, diverse life could emerge. But with the earliest evidence for such life at 580 million years ago, a 55 million year gap separated complex modern life with its potential beginning. The new fossils fit into that gap.
"If I want to be conservative, I'd say they've described evidence of when plants began. If I'm feeling grandiose, I'd say it may be the oldest evidence of macroscopic multicellularity," said paleobiologist Guy Narbonne of Queens University in Canada, who wasn't involved in the study. "The truth is probably somewhere in between."
Xiao and his colleagues found their specimens in a rocky outcrop discovered in China's southern Anhui Province. Survey geologists decades ago discovered rich fossil beds within a 260-foot-thick section of rock called the Lantian Formation, but age estimations were rough at best.
To get around the difficulty of directly dating specimens, Xiao's team linked the Lantian layers of rock to corresponding, precisely dated formations hundreds of miles away. The fossils proved to be sandwiched between layers laid down between 580 million and 635 million years ago.
Since the researchers began digging up one site about a year ago, they've unearthed more than 3,000 detailed specimens. "It was a very different world then than it is now, just algae and bacteria. Burrowing animals hadn't evolved yet, so sediments on the bottom weren't being churned up," said Xiao. "You get these beautiful fossils as a result."
Most of the rust-colored specimens have splayed branches, sweeping fans and conical blooms resembling those of modern kelps. A small subset look more like the precursors of modern animals called bilaterians, with their symmetrical tubes and ribbons.
Xiao cautioned, however, that knowledge of the fossils is too fresh to make firm conclusions.
"It's almost impossible for us to shoehorn them into modern phyla. There are probably some animals, but we're just not sure," Xiao said. "They don't look like algae, yet we don't see any modern animal analogs. They may be offshoots that died out."
Narbonne, who wrote an accompanying commentary in Nature, said the new and more accurately dated Lantian fossils could help resolve persisting riddles of ancient oxygen levels. "We know the deep oceans became oxygenated about 500 million years ago, around the time of the Cambrian explosion. But with older oceans, we're not as certain," Narbonne said.
Even large, multicellular life forms — including algae — require oxygen to survive. "Their story is entirely consistent with a shallow, sunbathed, oxygenated environment," he said.
However, there's a wrinkle in the evidence, Narbonne explained. Geochemical tests of the Lantian rock indicate the algae lived in oxygen-free oceans.
Xiao said the tests were performed on rock layers about 20 inches apart — a sedimentary distance representing millions of years in time. In the future, he'd like to do tests every half-inch or so, looking for brief spurts of oxygenation that would have supported algae and other complex life.
"But the really hard, really tedious work we now face is to systematically and carefully describe each of the thousands of specimens recovered from the site," Xiao said. "That data is going to be the bread and butter of our scientific understanding."
Images: Some of thousands of purported 600-million-year-old fossils recovered from the Lantian Formation in China's southern Anhui Province. (Zhe Chen/Nature)
Posted: 16 Feb 2011 10:53 AM PST
Even as humans have homogenized other domestic animals, replacing nature's diversity with a few useful breeds, dog diversity has exploded. A kaleidoscope of shapes and sizes have come from an original stock of wolves; there are hundreds of breeds, so many that it was long impossible to determine where they'd all come from.
That diversity made dogs an interesting puzzle for geneticists. By mapping subtle differences in each breed's genes, searching for patterns of relationships and designing a tree to fit them, they could finally gain insight into this marvel of evolutionary engineering.
In 2004, the foundational analysis of purebred dog genetics was published in Science. The resulting tree was profoundly asymmetrical. After wolves, just four groups sat its base: Asia's shar-pei, along with shiba inu, akita and chow chow; central Africa's basenji; malamutes from the Arctic, along with Siberian huskies and samoyeds; and from the Middle East, Afghan hounds and salukis.
Then, on one last branch, came every other dog breed. If the tree was really a tree, it would topple immediately to one side.
But within that hodgepodge branch — the product, in part, of a Victorian-inspired predilection for fanciful mixes — were three basic groups: the Lhasa apso, shih tzu, Pekingese and Tibetan terrier; the mastiff, plus bulldogs, boxers, bull terriers, rottweilers, German shepherds and Bernese mountain dogs; and Shetland sheepdogs, along with collies, Belgian tervurens, Belgian sheepdogs, Irish wolfhounds, greyhounds, borzoi and Saint Bernards.
Ibizan and Pharaoh hounds, long thought to be ancient breeds, actually proved to be recent re-creations, with modern breeds used to revive ancient combinations of traits.
On the following pages are pictures of these ancient (and one not-so-ancient) breeds, taken Feb. 14 and 15 at the Westminster Kennel Club dog show in New York City. More photographs of other breeds can be found on Flickr.
Posted: 16 Feb 2011 09:00 AM PST
Certain words can shake the blogosphere in much the same way earthquakes stir the planet.
A new study of word frequencies in political blogs finds that equations describing earthquake evolution fit the eruption of topics onto political blogs.
News tends to move quickly through the public consciousness, noted physicist Peter Klimek of the Medical University of Vienna and colleagues in a paper posted on arXiv.org. Readers usually absorb a story, discuss it with their friends, and then forget it. But some events send lasting reverberations through society, changing opinions and even governments.
"It is tempting to see such media events as a human, social excitable medium," wrote Klimek's team. "One may view them as a social analog to earthquakes."
To see how far this analogy went, Klimek and colleagues trawled 168 political blogs in the US between July 2008 and May 2010, looking for spikes in the frequency of individual words.
The blogs came from every neighborhood of the political blogosphere, from commentators and journalists like Glenn Beck and Taylor Marsh, to civilian bloggers describing themselves as everything from "far right" to "liberal curmudgeons."
To make sure their search wasn't biased toward particular words, the researchers wrote a computer program to search for all possible letter triplets: aaa, aab, aac, and so on through zzz. More than half of these triplets never showed up, but for the ones that did, Klimek and company listed the days when each triplet was most common and the words they were found in.
This process left them with roughly 4,000 keywords. The researchers then searched their database for instances of those words for 30 days before and after the peak.
The types of blogosphere responses took two forms, the researchers say. Some words suddenly spiked in popularity in response to a real-world event. Sarah Palin's nomination as the Republican vice presidential candidate was the most dramatic example.
"Indeed, aftershocks of this event are still trembling and quivering through our society," Klimek and colleagues wrote. Because these events are triggered from outside the blogosphere, the researchers called them "exogenous."
Other words gradually grew in frequency and then died down, like the use of the word "inauguration" in the days before and after Barack Obama took office. Such events are called "endogenous" because they seem to arise within the blogosphere itself.
The researchers found that on average, 0.2 words from within the blogosphere and 1.5 words from the outside world spiked in frequency per day. For both cases, the equation that fits a graphical plot of event frequency versus event size looks similar to the Gutenberg-Richter law, which describes the relationship between magnitude and number of earthquakes in a given region.
Events that came from outside the blogosphere also seemed to exhibit aftershocks that line up with Omori's law for the frequency of earthquake aftershocks.
"We show that the public reception of news reports follow a similar statistic as earthquakes do," the researchers conclude. "One might also think of a 'Richter scale' for media events."
"I always think it's interesting when people exploit the scale of online media to try to understand human behavior," said Duncan Watts, a researcher at Yahoo! Research who describes himself as a "reformed physicist who has become a sociologist."
But he notes that drawing mathematical analogies between unrelated phenomena doesn't mean there's any deeper connection. A lot of systems, including views on YouTube, activity on Facebook, number of tweets on Twitter, avalanches, forest fires, power outages and hurricanes all show frequency graphs similar to earthquakes.
"But they're all generated by different processes," Watts said. "To suggest that the same mechanism is at work here is kind of absurd. It sort of can't be true."
Watts thinks the data set that Klimek and colleagues compiled could be used to study other questions.
"Who is generating these large events? Do they happen randomly? Is there a hierarchy that you could extract in the media world, where there's this core group of bloggers and everyone copies them? Or are they consumers and rebroadcasters of stories other people are coming up with?" Watts said. "That I think would be interesting, and might tell us something about the world that we didn't already know."
Image: 1) Flickr/fourpointreport. 2) Klimek et al 2011.
"The blogosphere as an excitable social medium: Richter's and Omori's Law in media coverage." Peter Klimek, Werner Bayer, Stefan Thurner. arXiv.org, Feb. 10, 2011.
Posted: 16 Feb 2011 07:55 AM PST
The kicks and somersaults of a developing baby aren't the only in-utero calisthenics. Babies also flex their mental muscles months before birth.
Nerve cells from developing brains as young as 20 weeks old fire in a pattern that persists into adulthood, researchers reported Tuesday in the Journal of Neuroscience. The research provides a glimpse into the behavior of extremely young brain cells and could help scientists understand what happens when brain development goes awry.
Cells from the cerebral cortices of 20- to 21-week-old fetuses exhibit bursts of electrical activity interspersed with periods of quiet, researchers from the University of Connecticut Health Center in Farmington found. When the adult brain is sleeping, or under anesthesia, it also displays this busy-then-quiet firing pattern, suggesting it may be an intrinsic property of human brains.
The cerebral cortex deals with sensory information, thinking, emotion and consciousness. But even when not receiving input from the outside world, the nerve cells, or neurons, in this region oscillate between firing and resting.
"In adults, we go to sleep and the cortex is disconnected from the outside environment — it sleeps alone. But you see this quiet synchronized activity," says Igor Timofeev of Laval University in Québec. That young nerve cells behave in a similar way long before they grapple with outside input suggests that the firing pattern "is a very basic feature of the brain that occurs in very early stages of development," says Timofeev.
Scientists still don't understand what purpose the nerve cell activity serves so early in development. Perhaps it is a flexing of mental muscles to help keep the cells alive, says neuroscientist Srdjan Antic, who led the new study. Having a burst of activity now and again may signal other brain cells that "'Hey I'm here, look at me, maintain a connection with me,'" Antic says. "During sleep neurons do exactly that."
Antic and colleagues probed the activity of neurons in lab dishes one at a time. While almost all of the cells exhibited the firing pattern, the team can't say whether the firing was synchronized. If the cells do fire in waves, that could be their way of signaling their location to other brain cells, says neuroscientist William Moody of the University of Washington in Seattle.
Such wave-signaling in mice brains plays a role in wiring the nervous system during development so that adjacent brain regions correspond to adjacent body parts. If these young cells are firing in waves, that activity could be part of this mapping process, Moody says.
"This is a huge deal," he says of the new work. "They've taken the first step of looking at humans."
There are several disorders that may result when neurons don't end up in the right place. And autism spectrum disorders may also be related to improper firing, says Moody.
Image: Adult brain activity, as seen in a Positron Emission Topography (PET) scan. (Reigh LeBlanc/Flickr)
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