A favorite theme of science fiction is "the portal"--an extraordinary opening in space or time that connects travelers to distant realms. A good portal is a shortcut, a guide, a door into the unknown. If only they actually existed....
It turns out that they do, sort of, and a NASA-funded researcher at the University of Iowa has figured out how to find them.
"We call them X-points or electron diffusion regions," explains plasma physicist Jack Scudder of the University of Iowa. "They're places where the magnetic field of Earth connects to the magnetic field of the Sun, creating an uninterrupted path leading from our own planet to the sun's atmosphere 93 million miles away."
Observations by NASA's THEMIS spacecraft and Europe's Cluster probes suggest that these magnetic portals open and close dozens of times each day. They're typically located a few tens of thousands of kilometers from Earth where the geomagnetic field meets the onrushing solar wind. Most portals are small and short-lived; others are yawning, vast, and sustained. Tons of energetic particles can flow through the openings, heating Earth's upper atmosphere, sparking geomagnetic storms, and igniting bright polar auroras.
NASA is planning a mission called "MMS," short for Magnetospheric Multiscale Mission, due to launch in 2014, to study the phenomenon. Bristling with energetic particle detectors and magnetic sensors, the four spacecraft of MMS will spread out in Earth's magnetosphere and surround the portals to observe how they work.
Just one problem: Finding them. Magnetic portals are invisible, unstable, and elusive. They open and close without warning "and there are no signposts to guide us in," notes Scudder.
Actually, there are signposts, and Scudder has found them.
Portals form via the process of magnetic reconnection. Mingling lines of magnetic force from the sun and Earth criss-cross and join to create the openings. "X-points" are where the criss-cross takes place. The sudden joining of magnetic fields can propel jets of charged particles from the X-point, creating an "electron diffusion region."
To learn how to pinpoint these events, Scudder looked at data from a space probe that orbited Earth more than 10 years ago.
"In the late 1990s, NASA's Polar spacecraft spent years in Earth's magnetosphere," explains Scudder, "and it encountered many X-points during its mission."
Because Polar carried sensors similar to those of MMS, Scudder decided to see how an X-point looked to Polar. "Using Polar data, we have found five simple combinations of magnetic field and energetic particle measurements that tell us when we've come across an X-point or an electron diffusion region. A single spacecraft, properly instrumented, can make these measurements."
This means that single member of the MMS constellation using the diagnostics can find a portal and alert other members of the constellation. Mission planners long thought that MMS might have to spend a year or so learning to find portals before it could study them. Scudder's work short cuts the process, allowing MMS to get to work without delay.
It's a shortcut worthy of the best portals of fiction, only this time the portals are real. And with the new "signposts" we know how to find them.
Scientists bring 500 million-year-old bacteria back to life
A 500 million-year-old bacteria has been brought back to life in a laboratory at Georgia Tech in an experiment with echoes of Jurassic Park's disastrous recreation of the dinosaurs.
The researchers have resurrected a 500-million-year-old gene and inserted it into a modern E Coli bacteria.
The 'Frankenstein' germ has thrived. In the lab, the creation has now lived through 1,000 generations.
The scientists hope to find out whether the 'ancient' bacteria will evolve the same way it did 'first time round' - or whether it will evolve into a different, new organism.
‘This is as close as we can get to rewinding and replaying the molecular tape of life,’ said scientist Betül Kaçar, a NASA astrobiology postdoctoral fellow in Georgia Tech.
The new 'chimeric' bacteria has mutated rapidly - and some have become stronger and healthier than today's germs.
‘The ability to observe an ancient gene in a modern organism as it evolves within a modern cell allows us to see whether the evolutionary trajectory once taken will repeat itself or whether a life will adapt following a different path.’
‘The altered organism wasn’t as healthy or fit as its modern-day version, at least initially,’ said Gaucher, ‘and this created a perfect scenario that would allow the altered organism to adapt and become more fit as it accumulated mutations with each passing day.’
The growth rate eventually increased and, after the first 500 generations, the scientists sequenced the genomes of all eight lineages to determine how the bacteria adapted.
Scientists Engineer "Chimera" Primates to Combat Human Ailments
Roku, Hex and Chimero are the world’s first primate chimeras—individual monkeys made from multiple fertilized eggs of the same species. Each animal has six different sets of genes instead of one. To produce each monkey, biologist Shoukhrat Mitali*pov and his team at the Oregon Health and Science University placed six separate four-celled embryos into a petri dish and, using a micropipette, nudged them into a single aggregation. After a few days, the researchers implanted the aggregation into an adult female macaque. The resulting young have cells descended from each of six embryos evenly distributed throughout their bodies.
Researchers make chimeras in order to create better models for studying human disease. For example, to study human cancers, scientists produce chimeras to delete or mutate certain cell-growth genes and thus produce mice that develop tumors. But mouse models are only so useful—more than 90 percent of drugs tested in mice in the laboratory fail when used on people. Chimeras, on the other hand, could enable scientists to perform similar mutations and drug research in nonhuman primates, which are biologically closer to humans, and therefore more likely to produce helpful data. One result may be more medical research on primates, though, which raises ethical questions.
Ancient Rain Forrest Found Under Miles Of Ice In Antarctica
Antarctica has yielded implications about global warming that are chilling.
Drilling deep into the seabed just off Earth's southernmost continent, researchers have discovered remnants of a near-tropical rainforest that existed 50 million years ago.
During this period, known as the early Eocene era, the Earth experienced dramatic greenhouse conditions with high atmospheric carbon dioxide counts and palm trees growing around the South Pole.
Ancient history, right? Not according to an article in this week's issue of Nature, where Antarctic researchers warn that, while the 30 percent growth of our CO2 levels since the Industrial Revolution are still a fraction of the Eocene's, they are projected to see those very same prehistoric greenhouse gas levels within decades, issuing in the start of another Eocene-like epoch.
Looks like it might be time to start passing out sunblock to those penguins.
We all need to clear our heads, sometimes literally — and now scientists have learned how our neurological plumbing system works.
Every organ produces waste, and the brain is no exception. But unlike the rest of our body, it doesn’t have a lymphatic system, a network of vessels that filter out junk. Now, a new study of mouse brains suggests how ours handle waste: by rapidly pumping fluid along the outside of blood vessels, literally flushing waste away. The finding, reported Aug. 15 in Science Translational Medicine, could hint at how diseases like Alzheimer’s develop and might be treated.
“If you look at a body-wide map of the lymphatic system, you see a great big void in the brain,” said neuroscientist Jeffrey Iliff of the University of Rochester Medical Center. He and his colleagues found that puzzling, given how active the brain is and how sensitive it is to waste buildup.
Scientists long suspected that the brain’s refuse ended up in the cerebrospinal fluid, which cushions the brain inside the skull. In the 1980s, some researchers proposed that the fluid might be pumped into the brain to wash it, then pumped out again. Other researchers weren’t convinced.
Thanks to new imaging techniques that made it possible to peer inside the brain of a living mouse, Iliff’s team saw the process in action. Cerebrospinal fluid flowed along the outside of blood vessels, carried through a network of pipe-like protein structures. The fluid picked up waste that accumulated between cells, then drained out through major veins.
“These experiments validate a powerful ‘prevailing current’ of cerebrospinal fluid in brain extracellular space that effectively clears metabolic garbage,” said neurologist Bruce Ransom of the University of Washington, who was not affiliated with the study.
Iliff’s group went on to show that mice brains without these channels did poorly at clearing waste, including amyloid protein, buildup of which is linked to Alzheimer’s disease. They cleared waste 70 percent more slowly than mice possessing the channels.
Healthy brains produce amyloid normally, but this system clears it out frequently, the researchers suspect. In an Alzheimer’s brain, ”it builds up and builds up and builds up, until eventually it forms the plaques that can clog up the brain,” said Iliff.
In theory, you could prevent or slow that buildup by improving the brain’s flushing system. “The key is, we have to find a way to ‘turn up’ the system,” Iliff said. This could also apply to other brain conditions, such as Parkinson’s disease or stroke.
Iliff and colleagues used a combination of old and new imaging methods to visualize fluid circulation. The standard method involves injecting a radioactive tracer chemical into a slice of brain tissue, shining light on it, and watching how it fluoresces (above right). But this method only provides snapshots of dead brains. With a new technique called two-photon imaging, which can detect radioactive tracers hit with just two low-energy photons, the researchers could see deep into the brain of a living mouse.
More research is needed to fully understand how the waste system works in human brains, which can’t be studied as easily as mice. Still, the findings are important, said Ransom. “After decades of uncertainty about cerebrospinal fluid movement in brain, we finally know which way the wind is blowing,” he said.
Citation: “A Paravascular Pathway Facilitates CSF Flow Through the Brain Parenchyma and the Clearance of Interstitial Solutes, Including Amyloid β.” By Jeffrey J. Iliff, Minghuan Wang, Yonghong Liao, Benjamin A. Plogg, Weiguo Peng, Georg A. Gundersen, Helene Benveniste, G. Edward Vates, Rashid Deane, Steven A. Goldman, Erlend A. Nagelhus, Maiken Nedergaard. Science Translational Medicine, Vol. 4 Issue 147, August 15, 2012.
Scientists: Climate change forced Egyptians to stop building pyramids
Ancient pollen and charcoal preserved in deeply buried sediments in Egypt’s Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt’s Old Kingdom, the era known as the pyramid-building time.
A newly released study finds that drought brought on by climate change may have ended the era of pyramid building in Egypt.
The study, conducted by USGS and University of Pennsylvania, finds that a series of extreme droughts and Scientists examined 7,000-year-old ancient pollen and charcoal samples from the Nile to piece together the time – and found evidence of a ‘mega drought’ in the the area. The study notes that wetland pollen decreased during droughts, while charcoal use increased. Researchers says that the presence of charcoal was considered to be highest some 5,000 to 5,500 years ago.
“Humans have a long history of having to deal with climate change,” said Christopher Bernhardt, a researcher with the U.S. Geological Survey. “Along with other research, this study geologically reveals that the evolution of societies is sometimes tied to climate variability at all scales – whether decadal or millennial.”
The team of researchers noted that the study reveals that humans have struggled to cope with the effects of drought. The team of geologists said fossilized material from the region provided data that shows Egyptians struggling to adjust to the growing challenge of climate change. The researchers studied pollen and charcoal preserved in a Nile Delta sediment core that dates back 7,000 years, some of the oldest samples recovered.
“Even the mighty builders of the ancient pyramids more than 4,000 years ago fell victim when they were unable to respond to a changing climate,” said USGS Director Marcia McNutt. “This study illustrates that water availability was the climate-change Achilles Heel then for Egypt, as it may well be now, for a planet topping seven billion thirsty people.”
The study comes as climate change remains a major issue for several governments around the world. International policy makers have struggled to address the issue in recent years, however, various international summits have failed to build a consensus over the best possible path towards lowering emissions of greenhouse gases.
These events are also recorded in human history – the first one started some 5,000 years ago when the unification of Upper and Lower Egypt occurred and the Uruk Kingdom in modern Iraq collapsed. The second event, some 3,000 years ago, took place in the eastern Mediterranean and is associated with the fall of the Ugarit Kingdom and famines in the Babylonian and Syrian Kingdoms, according to scientists.
Mr. Bernhardt along with Benjamin Horton, an associate professor in Penn’s Department of Earth and Environmental Science, conducted the study. Jean-Daniel Stanley at the Smithsonian Institution also participated in the study, published in July’s edition of Geology.
Support for the work came from the University of Pennsylvania, the U.S. Geological Survey, and the Smithsonian Institution.
A dramatic gash in the surface of the Earth that could rival the majesty of the Grand Canyon has been discovered secreted beneath Antarctica's vast, featureless ice sheet.
Dubbed the Ferrigno Rift for the glacier that fills it, the chasm's steep walls plunge nearly a mile down (1.5 kilometers) at its deepest. It is roughly 6 miles (10 km) across and at least 62 miles (100 km) long, possibly far longer if it extends into the sea.
The rift was discovered during a grueling 1,500-mile (2,400 km) trek that, save for a few modern conveniences, hearkens back to the days of early Antarctic exploration. And it came as a total surprise, according to the man who first sensed that something incredible was literally underfoot, hidden by more than a half-mile (1 km) of ice.
Robert Bingham, a glaciologist at the University of Aberdeen, along with field assistant Chris Griffiths, had embarked on a nine-week trip during the 2009-2010 field season to survey the Ferrigno Glacier, a region humans had visited only once before, 50 years earlier. Over the last decade, satellites have revealed the glacier is the site of the most dramatic ice loss in its West Antarctica neighborhood, a fringe of coastline just west of the Antarctic Peninsula — the narrow finger of land that points toward South America.
The two-man team set out aboard snowmobiles, dragging radar equipment behind them to measure the topography of the rock beneath the windswept ice, in a region notorious for atrocious weather. Braced for arduous, yet uneventful fieldwork, the surprise came right away. [Images: Antarctica's Icy Wilderness]
"It was literally one of the first days that we were driving across the ice stream, doing what we thought was a pretty standard survey, that I saw the bed of the ice just dropping away," Bingham said.
The drop was so sudden and so deep that Bingham drove back and forth across the area two or three more times to check the data, and saw the same pattern. "We got the sense that there was something really exciting under there," he told OurAmazingPlanet. "It was one of the most exciting science missions I've ever had."
Bingham compared the hidden chasm to the Grand Canyon in scale, but said that tectonic forces of continental rifting — in contrast to erosion — created the Ferrigno Rift, wrenching the fissure's walls apart probably tens of millions of years ago, when Antarctica was ice-free.
Excitement surrounding the discovery has deeper implications than the mere gee-whiz factor of finding such a massive feature. The Ferrigno Rift's "existence profoundly affects ice loss," Bingham and co-authors from the British Antarctic Survey wrote in a paper published in Nature today (July 25).
"The geology and topography under the ice controls how the ice flows," said Robin Bell, a geophysicist and professor at Columbia University's Lamont-Doherty Earth Observatory, who was not associated with the research. "Ice will flow faster over sediments, like those found in rifts," said Bell, a veteran Antarctic researcher, who has long studied yet another dramatic, yet invisible geological feature, the hidden Gamburtsev Mountains in East Antarctica.
In addition, the study authors write, the rift is providing a channel for warm ocean water to creep toward the interior of the West Antarctic Ice Sheet, gnawing away at the Ferrigno Glacier from below.
Together, these two factors could be speeding the glacier's march to the sea, and the overall effects could have implications for the stability of the West Antarctic Ice Sheet, which is responsible for 10 percent of global sea level rise that is currently happening.
Scientists are still only just beginning to understand the myriad mechanisms that control the seemingly dramatic melting observed in regions of West Antarctica, and how climate change is affecting all the moving parts.
"With something like the Antarctic ice sheet, some of these processes take centuries, and the amount of time we've been able to observe changes is at the maximum 20 years," Bingham said. "It's a very small amount of time."