Indiana Jones Meets George Jetson

A team of researchers from Uppsala University in Sweden has designed a microplasma source capable of exciting matter in a controlled, efficient way. This miniature device may find use in a wide range of applications in harsh environments, but can also help revolutionize archaeology.

As the researchers describe in the Journal of Applied Physics, produced by AIP Publishing, their new device offers many advantages, such as electromagnetic compatibility, an integrated fluidic system, and Langmuir probes for plasma diagnostics.

At the university's Ångström Space Technology Centre (ÅSTC), the researchers work with many kinds of micro and nanotechnologies for use in space and other harsh environments: scientific instruments, imaging, communication hardware, vehicles and spacecraft, propulsion devices, and thermal management. Size limitation is always a huge challenge.

"Putting miniaturized hardware into orbit or thousands of meters underground is always technically easier and less expensive, but using fundamentally different technology for demanding applications is often met with skepticism," explains Greger Thornell, director of ÅSTC. "So we need to also compete in terms of performance and reliability."

The researchers are accustomed to working with microrocketry and localized phenomena in tiny devices such as sensors and actuators. These types of phenomena sometimes involve very high temperatures, intense plasma, and high pressures.

"In this case, the localization, or rather concentration, means that the device itself becomes handy and power-efficient, and also that it consumes small sample amounts, which widens the range of applications far beyond the requirement of simply lightweight or portable instruments," said Thornell.

Archaeology is one of the main applications being investigated right now to help determine the distribution of carbon isotopes in organic samples. "This information is critical for archaeologists, but measuring these isotope distributions can be extremely painstaking and time consuming," said Anders Persson, senior researcher.

Their plasma source may be used to develop an instrument for field archaeologists, which would allow them to perform measurements while out in the field; this in turn may revolutionize archaeology by diversifying the amount of information available during the decision-making process of an excavation. "Archaeology is just one of the many exciting applications we see for our plasma source," he added.

Read more at Science Daily

TB Migrated Out of Africa With Humans

The bacteria that cause tuberculosis emerged at least 70,000 years ago and followed humans out of Africa, suggests new research.

From there, TB tagged along on human migrations and evolved as people changed. The new findings offer insight into a disease that kills as many as 2 million people every year and is increasingly developing resistance to drugs designed to treat it.

“The evolutionary path of humans and the TB bacteria shows striking similarities,” said Sebastien Gagneux from the Swiss Tropical and Public Health Institute in a press release. “We see that the diversity of tuberculosis bacteria has increased markedly when human populations expanded.”

Between the 17th and 19th centuries, TB killed 20 percent of adults in Europe and North America. Even today, it remains one of the deadliest infectious diseases in humans, particularly in developing countries. When untreated, it kills half of all people it infects.

To better understand the history of TB, Gagneux and colleagues sequenced and compared the genomes of 259 strains of the M. tuberculosis bacteria from around the world. Then they reconstructed a TB family tree, which allowed them to trace back the origins of the disease to somewhere in Africa about 70,000 years ago.

When the researchers compared the TB family tree with the history of human migrations, they reported in the journal Nature Genetics, they found remarkable similarities. The disease split into branches at the same time that waves of hunter-gatherers left Africa and moved into Europe and Asia.

A boom in human population around 10,000 years ago also coincided with the expansion of TB, probably because denser groups of people allowed the disease to spread more easily.

Read more at Discovery News

Beneath Earth's Surface, Scientists Find Long 'Fingers' of Heat

Scientists seeking to understand the forces at work beneath the surface of Earth have used seismic waves to detect previously unknown "fingers" of heat, some of them thousands of miles long, in Earth's upper mantle. Their discovery, published Sept. 5 in Science Express, helps explain the "hotspot volcanoes" that give birth to island chains such as Hawai'i and Tahiti.

Many volcanoes arise at collision zones between the tectonic plates, but hotspot volcanoes form in the middle of the plates. Geologists have hypothesized that upwellings of hot, buoyant rock rise as plumes from deep within Earth's mantle -- the layer between the crust and the core that makes up most of Earth's volume -- and supply the heat that feeds these mid-plate volcanoes.

But some hotspot volcano chains are not easily explained by this simple model, a fact which suggests there are more complex interactions between these hot plumes and the upper mantle. Now, a computer modeling approach, developed by University of Maryland seismologist Vedran Lekic and colleagues at the University of California Berkeley, has produced new seismic wave imagery which reveals that the rising plumes are, in fact, influenced by a pattern of finger-like structures carrying heat deep beneath Earth's oceanic plates.

Seismic waves are waves of energy produced by earthquakes, explosions and volcanic eruptions, which can travel long distances below Earth's surface. As they travel through layers of different density and elasticity, their shape changes. A global network of seismographs records these changing waveforms. By comparing the waveforms from hundreds of earthquakes recorded at locations around the world, scientists can make inferences about the structures through which the seismic waves have traveled.

The process, known as seismic tomography, works in much the same way that CT scans (computed tomography) reveal structures hidden beneath the surface of the human body. But since we know much less about the structures below Earth's surface, seismic tomography isn't easy to interpret. "The Earth's crust varies a lot, and being able to represent that variation is difficult, much less the structure deeper below" said Lekic, an assistant professor of geology at the College Park campus.

Until recently, analyses like the one in the study would have taken up to 19 years of computer time. While studying for his doctorate with the study's senior author, UC Berkeley Prof. Barbara Romanowicz, Lekic developed a method to more accurately model waveform data while still keeping computer time manageable, which resulted in higher-resolution images of the interaction between the layers of Earth's mantle.

By refining this method, a research team led by UC Berkeley graduate student Scott French found finger-like channels of low-speed seismic waves flowing about 120 to 220 miles below the sea floor, and stretching out in bands about 700 miles wide and 1,400 miles apart. The researchers also discovered a subtle but important difference in speed: at this depth, seismic waves typically travel about 2.5 to 3 miles per second, but the average seismic velocity in the channels was 4 percent slower. Because higher temperatures slow down seismic waves, the researchers infer that the channels are hotter than the surrounding material.

"We estimate that the slowdown we're seeing could represent a temperature increase of up to 200 degrees Celsius," or about 390 degrees Fahrenheit, said French, the study's study lead author. At these depths, absolute temperatures in the mantle are about 1,300 degrees Celsius, or 2,400 degrees Fahrenheit, the researchers said.

Geophysicists have long theorized that channels akin to those revealed in the computer model exist, and are interacting with the plumes in Earth's mantle that feed hotspot volcanoes. But the new images reveal for the first time the extent, depth and shape of these channels. And they also show that the fingers align with the motion of the overlying tectonic plate. The researchers hypothesize that these channels may be interacting in complex ways with both the tectonic plates above them and the hot plumes rising from below.

Read more at Science Daily

Toxic Gas First Used in Syria 1,700 Years Ago

If Syrian President Bashar al-Assad has really carried out a chemical attack, it wouldn’t be the first time poisonous gas brought death in the Middle East country.

Indeed, right in Syria archaeologists have found some of the oldest evidence of chemical warfare.

According to University of Leicester archaeologist Simon James, who published his findings back in 2009, poison gas was used in Syria more than 1,700 years ago when a Roman fort at Dura-Europos became the site of a violent siege by the powerful Sasanian Persian empire.

No historical record exists of the battle, which occurred around 256 A.D., but archaeological remains, unearthed by major excavations in 1920-1937 by teams from France and Yale University, and after 1986 by French-Syrian teams, helped James piece together the action.

Trying to enter the city, the Sasanians dug tunnels underneath its walls. Intending to hold their ground at all costs, Roman defenders responded with counter-mines.

In the 1930s, archaeologists unearthed dramatic evidence of the fight. In one of the tunnels, a pile of bodies, still completely fitted with their weapons and armour, testified to the horrors of the battle.

At the time, the researchers believed the trapped Roman soldiers had died after the tunnel collapsed. But according to James, residue of pitch (a resinous substance) and yellow sulfur crystals found in a jar lying near the bodies indicated a much more gruesome reality.

Indeed, the Sasanians placed fire pits strategically throughout the tunnel, and when the Romans broke through, they gassed them by adding sulfur crystals and bitumen to the fire.

“Defining what constitutes a chemical weapon in antiquity is complex, but this is certainly one of the earliest archaeological finds of the addition of chemical accelerants to a fire to produce toxic fumes,” Adrienne Mayor, a research scholar in classics and history of science at Stanford University, told Discovery News.

Mayor described the skirmish in the tunnel and the presence of burnt residue as an early example of archaeological evidence for a chemical incendiary in her 2003 book “Greek Fire, Poison, Arrows and Scorpion Bombs.”

According to the scholar, a possible contender for the earliest archaeological evidence for a chemical weapon is a charred, manmade fire ball from the archaeological battle site at Gandhara, Pakistan.

“The burning missile had been hurled at Alexander’s besieging army in 327 BC. Chemical analysis revealed the ball’s composition included sulfur, barite, and pitch,” Mayor said.

The ball was certainly ignited in a fire, but whether this was deliberate or accidental is impossible to establish.

Long before World War I, when 39 different toxic agents — ranging from simple tear gas to mustard gas — were extensively used, it was a mixture of sulfur and pitch that gassed enemies.

Greek historian and Athenian general Thucydides described how, during the Peloponnesian War, the Spartans created a sulfur and pitch (in this case pine resin) fire at the siege of Plateia, Greece, in 429 BC.

The Boeotians, Sparta’s allies, used a similar chemical flame-thrower in 424 BC at Delium, combining burning coal, sulfur and pitch.

Read more at Discovery News

Witch Doctors' Animal Sacrifices Pollute Water Supply

Witch doctors regularly dump animal sacrifices into the reservoir meant to quench the thirst, clean the dishes and wash the clothes of 750,000 Venezuelans, reported Bloomberg. As a result, citizens of one of the most dangerous, crime-ridden cities in the world, Caracas, Venezuela, can’t even take a drink of water from the tap safely.

The 60-year old water treatment plant at the reservoir lacks the ability to filter out the toxins from the putrefying carcasses. Because of this, Caracas resisdents are now paying 30 Bolivars ($4.80) for a five-gallon jug of water. Gasoline only costs 14 Bolivars, due to generous government subsidies.

The water supply of Caracas seems cursed. Practitioners of Santeria sacrifice animals and dump their bodies with impunity into the reservoir.

“No one is bothering me here at all,” local Santeria practitioner Francisco Sanchez told Bloomberg.

Santeria is a hybrid, or syncretic, religion that sprang from the animistic beliefs of West African slaves blended with the Catholicism of their Spanish captors, mixed with the surviving remnants of indigenous people’s religions.

Although Santeria brings spiritual solace to thousands, in Venezuela, Santeria witch doctors dumping animal sacrifices into reservoirs mostly just increases the suffering of others, especially the poorest members of society.

In many regions of the developing world, people who drink water from the tap run the risk of bacterial infection or contamination from agricultural run-off and other pollutants. Many people spend a significant portion of their income on purified water to avoid the even greater cost of debilitating illness.

People who can’t afford bottled water have to find other ways of reducing their risks. For example in Honduras, people often use discarded soda bottles filled with tap water then placed those bottles in direct sun for a few days. The UV radiation from the sun kills off many pathogens, however it fails to filter out contaminants, such as animal feces.

Read more at Discovery News

Mystery Mummy Found in German Attic

German police, prosecutors and forensics experts are facing a mystery after a 10-year-old boy found a human mummy in a sarcophagus in a corner of his grandparents' attic.

A CT scan has revealed a well-preserved human skull, with an arrow sticking out of the left eye socket, and large parts of a skeleton with the arms crossed over the chest, the local newspaper Kreiszeitung has reported.

Adding to the riddle is a death mask also found in the box, and the fact that X-rays show a metal layer covering the bones of the 1.49-meter-long (4 feet 8 inches) human remains of unknown gender.

The boy's father, Lutz-Wolfgang Kettler, said his own father, who died 12 years ago, had in the 1950s travelled to North Africa and may have brought back the mummy as a grisly souvenir.

The bandages used for the mummy -- which has not been unwrapped for fear of damaging the remains -- date from the 20th century and are machine-woven, said Kettler, a dentist who attended the CT scan.

Pathologist Andreas Nerlich of Munich's Bogenhausen hospital told news website Spiegel Online that, while the skull and the bones are real, the mummy is "a fake, made from one or several human bodies."

Read more at Discovery News

New Low-Temperature Chemical Reaction Explained

In all the centuries that humans have studied chemical reactions, just 36 basic types of reactions have been found. Now, thanks to the work of researchers at MIT and the University of Minnesota, a 37th type of reaction can be added to the list.

The newly explained reaction -- whose basic outlines had been known for three decades, but whose workings had never been understood in detail -- is an important part of atmospheric reactions that lead to the formation of climate-affecting aerosols; biochemical reactions that may be important for human physiology; and combustion reactions in engines.

The new analysis is explained in a paper by MIT graduate student Amrit Jalan, chemical engineering professor William Green, and six other researchers, published in the Journal of the American Chemical Society.

Stephen Klippenstein, a senior scientist at the Argonne National Laboratory in Illinois who was not involved in this research, says, "I think this may be the best paper I have read this year. It uses a multitude of theoretical methods … to explore multiple aspects of a novel discovery that has important ramifications in atmospheric chemistry, combustion kinetics and biology."

The reaction's details sound esoteric: a low-temperature oxidation that results in the decomposition of complex organic molecules known as gamma-ketohydroperoxides. When he first described the reaction in the scientific literature 30 years ago, Stefan Korcek of the Ford Motor Company proposed a hypothesis for how the reaction might take place. The new work shows that Korcek had the right concept, although some details differ from his predictions.

The original discovery was the result of analyzing how engine oils break down through oxidation -- part of an attempt to produce oils that would last longer. That's important, Green points out, since waste oil is among the largest hazardous waste streams in the United States.

In analyzing the problem, Korcek realized that "there were fundamental things about the way even simple hydrocarbons react with oxygen that we didn't understand," Green says. By examining the products of the reaction, which included carboxylic acids and ketones, Korcek outlined an unusually complex multipart reaction. But for the next three decades, nobody found a way to verify whether the reaction or the steps he outlined could work.

Jalan says that the MIT researchers' analysis came about almost by accident. "I was looking at that paper for a different study," he says, "and I came across [Korcek's] work, which hadn't been verified either theoretically or experimentally. … [We] decided to see if we could explain his observations by throwing quantum mechanical tools at the problem."

In collaboration with the Minnesota researchers -- including Donald Truhlar, a co-author of the new paper and a leading expert in such calculations -- Jalan and Green were able to demonstrate exactly why the reaction works as it does. But they also found that part of the process must differ slightly from Korcek's original hypothesis.

Green says that understanding how this "very important reaction" works could be significant in several fields. The researchers' initial impetus was, in part, a colleague's exploration of biofuel combustion. The new understanding of the degradation that can take place as different fuels oxidize -- sometimes producing toxic or corrosive byproducts -- could help narrow the choice of fuel types to pursue, he says.

The process is also related to oxidations that take place in the body, contributing to the tissue damage and aging that antioxidant vitamins seek to combat, Green says.

Green points out that because this is an entirely new type of reaction, it opens the door to research on other variations. "Once you discover a new type of reaction, there must be many similar ones," he says.

"It's very odd to have so many reactions at once in such a small molecule," Green adds. "Now that we know that can happen, we're searching for other cases."

Anthony Dean, dean of the College of Applied Science and Engineering at the Colorado School of Mines, who was not involved in this work, says, "A particularly nice aspect of this work is to then consider how this finding might be applicable to other systems. In a broader context, this combined effort by two very prominent research groups illustrates the power and potential for electronic structure calculations [in] quantitatively important problems in chemical kinetics."

Read more at Science Daily

West Antarctica Ice Sheet Existed 20 Million Years Earlier Than Previously Thought

The results of research conducted by professors at UC Santa Barbara and colleagues mark the beginning of a new paradigm for our understanding of the history of Earth's great global ice sheets. The research shows that, contrary to the popularly held scientific view, an ice sheet on West Antarctica existed 20 million years earlier than previously thought.

The findings indicate that ice sheets first grew on the West Antarctic subcontinent at the start of a global transition from warm greenhouse conditions to a cool icehouse climate 34 million years ago. Previous computer simulations were unable to produce the amount of ice that geological records suggest existed at that time because neighboring East Antarctica alone could not support it.

The findings were published today in Geophysical Research Letters, a journal of the American Geophysical Union.

Given that more ice grew than could be hosted only on East Antarctica, some researchers proposed that the missing ice formed in the northern hemisphere, many millions of years before the documented ice growth in that hemisphere, which started about 3 million years ago. But the new research shows it is not necessary to have ice hosted in the northern polar regions at the start of greenhouse-icehouse transition.

Earlier research published in 2009 and 2012 by the same team showed that West Antarctica bedrock was much higher in elevation at the time of the global climate transition than it is today, with much of its land above sea level. The belief that West Antarctic elevations had always been low lying (as they are today) led researchers to ignore it in past studies. The new research presents compelling evidence that this higher land mass enabled a large ice sheet to be hosted earlier than previously realized, despite a warmer ocean in the past.

"Our new model identifies West Antarctica as the site needed for the accumulation of the extra ice on Earth at that time," said lead author Douglas S. Wilson, a research geophysicist in UCSB's Department of Earth Science and Marine Science Institute. "We find that the West Antarctic Ice Sheet first appeared earlier than the previously accepted timing of its initiation sometime in the Miocene, about 14 million years ago. In fact, our model shows it appeared at the same time as the massive East Antarctic Ice Sheet some 20 million years earlier."

Wilson and his team used a sophisticated numerical ice sheet model to support this view. Using their new bedrock elevation map for the Antarctic continent, the researchers created a computer simulation of the initiation of the Antarctic ice sheets. Unlike previous computer simulations of Antarctic glaciation, this research found the nascent Antarctic ice sheet included substantial ice on the subcontinent of West Antarctica. The modern West Antarctic Ice Sheet contains about 10 percent of the total ice on Antarctica and is similar in scale to the Greenland Ice Sheet.

West Antarctica and Greenland are both major players in scenarios of sea level rise due to global warming because of the sensitivity of the ice sheets on these subcontinents. Recent scientific estimates conclude that global sea level would rise an average of 11 feet should the West Antarctic Ice Sheet melt. This amount would add to sea level rise from the melting of the Greenland ice sheet (about 24 feet).

The UCSB researchers computed a range of ice sheets that consider the uncertainty in the topographic reconstructions, all of which show ice growth on East and West Antarctica 34 million years ago. A surprising result is that the total volume of ice on East and West Antarctica at that time could be more than 1.4 times greater than previously realized and was likely larger than the ice sheet on Antarctica today.

Read more at Science Daily

Mysterious Amazon Web Tower Baffles Scientists

A bizarre-looking web structure has been found in the Peruvian Amazon, and apparently nobody knows what it is, not even scientists.

The strange formation resembles a tiny spire surrounded by a webby picket fence and is about 2 centimeters (0.8 inches) wide. Georgia Tech graduate student Troy Alexander first spotted one of these on the underside of a tarp near the Tambopata Research Center in the Peruvian Amazon. At first he thought it might have been an aborted moth cocoon, he wrote on Reddit. But then he found several more, all of which looked quite similar.

He posted the photos to Reddit and asked other scientists to help him out, besides making queries around the Tambopata Research Center, to no avail. His guess is that "there are eggs in the base of the maypole in the middle of the horse corral, though it might be something pupating," he wrote on Reddit.

Chris Buddle, an arachnologist at McGill University, said that neither he nor any of his associates know what it is. "I have no clue," he said. It's "a seriously fascinating mystery."

"I have no idea what animal made that," Norman Platnick, curator emeritus of spiders at the American Museum of Natural History in New York, told LiveScience.

So far, Redditors and others have guessed that it could be some kind of moth cocoon, an intricate defense for spider eggs, or even the fruiting body of some type of fungus.

Alexander fell in love with the Peruvian Amazon while on vacation there, he told Colossal, an art blog. So he asked his adviser if he could take a leave of absence to be a volunteer researcher. Shortly thereafter, Alexander flew back to Peru to work at the Tambopata Macaw Project, which focuses on parrot biology and conservation, he told Colossal.

Read more at Discovery News

Mystery Alignment of 'Butterfly' Nebulae Discovered

Astronomers have discovered something weird in the Milky Way's galactic bulge -- a population of planetary nebula are all mysteriously pointing in the same direction.

While using the Hubble Space Telescope and the European Southern Observatory's New Technology Telescope (NTT) to survey 130 planetary nebulae situated near the hub of our galaxy, astronomers from the University of Manchester sorted them into three populations based on their shape: "elliptical," "either with or without an aligned internal structure" and "bipolar."

They noticed the mysterious alignment in the long axes of bipolar planetary nebulae.

Planetary nebulae are caused by the death of red giant stars. During their final years, long after the hydrogen fuel has run out in their cores, these puffed up stars begin to shed their outer layers, blasting huge quantities of material into space. At the end of its life the sun will also enter into a red giant phase, swallowing up the inner solar system planets (possibly even Earth), eventually creating its own planetary nebula.

The resulting nebulous clouds can take on many beautiful shapes, but bipolar planetary nebulae can be the most striking, generating two lobes of material expanding in opposite directions. These nebulae often resemble butterfly wings.

Although the surveyed nebulae are completely separate, non-interacting and are of various ages, the researchers noticed a large number of the nebulae long axes are aligned.

"This really is a surprising find and, if it holds true, a very important one," said Bryan Rees of the University of Manchester, co-author of the paper to appear in the journal Monthly Notices of the Royal Astronomical Society. "Many of these ghostly butterflies appear to have their long axes aligned along the plane of our galaxy. By using images from both Hubble and the NTT we could get a really good view of these objects, so we could study them in great detail."

The other two populations of planetary nebulae appear to be randomly oriented in relation to the galactic disk.

"While any alignment at all is a surprise, to have it in the crowded central region of the galaxy is even more unexpected," said the paper's second author Albert Zijlstra, also of the University of Manchester, in Wednesday's Hubble press release.

So what could be causing this strange alignment inside the galactic bulge?

The shapes of planetary nebulae are thought to be caused by factors such as the orientation of its system before the star turned into a red giant, or whether the star was part of a binary pair. But as for a common alignment across an apparently independent selection of nebulae, some external factor appears to be having a strong influence.

"The alignment we're seeing for these bipolar nebulae indicates something bizarre about star systems within the central bulge," said Rees. "For them to line up in the way we see, the star systems that formed these nebulae would have to be rotating perpendicular to the interstellar clouds from which they formed, which is very strange."

Interestingly, bipolar planetary nebulae do not appear to have a preferential orientation in our galactic neighborhood many thousands of light-years from the galactic core. The alignment effect only seems to act near the center of the Milky Way.

Read more at Discovery News