Jan 24, 2015
The swimmers are in one of the world's most extreme ecosystems, hidden beneath the Ross Ice Shelf, roughly 530 miles (850 kilometers) from the open ocean. "This is the closest we can get to something like Europa," Slawek Tulaczyk, a glaciologist at the University of California, Santa Cruz and a chief scientist on the drilling project, said, referring to Jupiter's icy moon.
This is the first time scientists have drilled through an ice shelf to its grounding line. These thick, floating tongues of ice are attached to glaciers or ice sheets, and the grounding line marks the transition from land to sea. Researchers with the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project punched through the ice with a custom hot-water drill on Jan. 8 and discovered the marine life on Jan. 16. The WISSARD drillers are crunching through the ice with the same setup used to reach Antarctica's subglacial Lake Whillans in 2013, when scientists grabbed the first evidence of microbial life from a lake under the ice sheet.
A remotely operated camera revealed the curious fish and amphipods, a type of crustacean that thrives in the ocean's harshest environments. For these translucent pink fish, which are about 8 inches (20 centimeters) long, this location is the farthest south they have ever been found, expedition scientists said. But the rocky seafloor was devoid of life. Tulaczyk said he thinks rocks that are constantly melting out of the ice sheet are responsible for the desolate conditions. Glacial ice can carry dust that is finer than flour or boulders bigger than buses.
"Forms of life that are sedentary will be stoned to death," he told Live Science from McMurdo Station in Antarctica. "The only things that can successfully explore food resources are things that can swim."
Yet the debris may also deliver much-needed nutrients — scarce in this dark, plankton-free world — in the form of ancient, carbon-rich marine sediments. For instance, ice cores brought up from the borehole contained shells called diatoms, the remains of microscopic marine creatures that lived and died before Antarctica froze over. "It could be we're looking at an old ecosystem eroding from the ice," Tulaczyk said.
The researchers also retrieved samples of the sediment and seawater, to investigate how Antarctica's ice shelves are responding to rising ocean temperatures. Models suggest that Antarctica's floating ice is melting from below as ocean temperatures increase. Because ice shelves hold back glaciers on land, as the shelves shrink, these flowing glaciers may speed up, boosting sea level rise by dropping ice into the ocean more quickly.
Read more at Discovery News
The organic carbon could be a temporary boon for tiny creatures at the bottom of the aquatic food chain that gobble the compound as food, but if this manna disappears because the glaciers have vanished, the overfed ocean ecosystems may collapse, the study authors warned.
"It could change the whole food web. We do not know how different ecological systems will react to a new influx of carbon," study co-author Robert Spencer, an assistant professor of oceanography at Florida State University, said in a statement.
Organic carbon is derived from plants or animals. The compound typically ends up in glaciers from microbes living in the ice, or from soot and other oil and gas byproducts.
Eran Hood, lead study author, and his colleagues estimated how much organic carbon is trapped in the world's glaciers and ice sheets, and how much will be released into the sea if melting continues its rapid pace. The supply of organic carbon in the world's waterways will increase by 50 percent in the next 35 years, according to the study, which was published Monday (Jan. 19) in the journal Nature Geoscience. That's about half the amount of organic carbon spilled into the sea each year by the Mississippi River, the researchers said.
"This research makes it clear that glaciers represent a substantial reservoir of organic carbon," said Hood, a scientist at the University of Alaska Southeast. "As a result, the loss of glacier mass worldwide, along with the corresponding release of carbon, will affect high-latitude marine ecosystems, particularly those surrounding the major ice sheets," he said. These high-latitude ecosystems are now receiving fairly limited inputs of organic carbon from land, Hood said in the statement.
Glaciers are shrinking nearly everywhere on Earth because of global warming, research studies have found. In West Antarctica, melt rates have tripled in the last decade, according to a study published in December 2014 in the journal Geophysical Research Letters. Ice loss in Greenland is five times faster now than in the early 1990s, scientists reported in November 2012 in the journal Science.
Read more at Discovery News
Jan 23, 2015
Similar to today’s stadium seating systems, the numbers — written according to the system used in ancient Rome, using letters of the Latin alphabet such as X, L, V, I — stood on the entrance gate arches, allowing an easier access to the seats.
First carved in the travertine stones, the numbers were then painted in red, so that people could easily see them from a distance.
There were 76 public numbered entrances, plus four special un-numbered gates. Two were reserved to the emperor, senators, magistrates, wealthy patricians, and the Vestal Virgins, priestesses responsible for maintaining the sacred fire within the Temple of Vesta. A gate was used for the dead — gladiators and wild beasts — while another was used by gladiators parading prior to the beginning of the combats.
The numbered entrance gates were the first step of a complex crowd control system which allowed tens of thousands of spectators to smoothly enter the amphitheater and quickly find their seat.
“The 50,000 spectators had a ticket that said which numbered gate arch they were supposed to enter. Inside the arena, there were other numbers to help people access their seats, which were assigned according to social class,” the monument director Rossella Rea said.
Although entrance was free for all, a strict plan regulated where one could seat on the amphitheater’s four levels of seating.
The best seat belonged to the emperor who sat in the first tier in the Emperor’s Box; the first level was also reserved to senator, magistrates and Vestal Virgins. On the second tier sat the upper class, on the third the ordinary Roman citizens, while women and the poor stood or sat on wooden benches in the fourth, top tier.
The traces of red painted numbers represent an “exceptional finding,” according to Rea.
“It was believed the paint would not have survived at all,” Rea said.
Deriving from iron oxide and clay minerals, the red color could be used without any binding material.
“As the color could withstand two-three years, it had to be periodically applied on the carved numbers,” restorer Cinzia Conti, said.
Read more at Disocovery News
Ancient people actually used heat from rocky vents in the mountain to cook food and make tools. When an Australian settler found the mountain in 1828, he assumed that he’d discovered a volcano.
Today, the smoking mountain and its weird landscape have become a tourist attraction. Australian Traveler describes it: “Smell the acrid sulfur. Feel the heat from the roasting 350-degree surface. Watch the pale grey smoke waft into the air. Look for wedge-tailed eagles soaring on the thermal currents above. Imagine you’re at the beginning of time. Or perhaps the end.”
But as Atlas Obscura notes, there’s a downside: “It has also caused massive ecological damage to the area’s vegetation. The path of the fire has left a barren and rocky trail, with no traces of life.”
There actually are many of these underground fires across the planet, They’re a type of low-temperature, flameless combustion called a smoldering fire. They can be ignited by natural events such as lightning, though humans can set them accidentally or intentionally, by burning down forests. Multiple fires, for example, recently have occurred at a coal mine about 700 miles from Burning Mountain, including on in early 2014 that burned for 45 days.
The fires also are a source of greenhouse gas emissions, contributing billions of tons of carbon dioxide to the atmosphere each year, according to this 2012 blog post by New York Times environmental reporter Andrew Revkin.
From Discovery News
Scientists using the Hubble Space Telescope have clocked the speed of gas bubbles, known as Fermi bubbles, at a whopping 2 million mph (3.2 million km/h). The giant structures now extend 30,000 light-years above and below the plane of the Milky Way.
"A few million years ago, there was a very energetic event at the galactic center, and we're seeing a remnant," lead author Andrew Fox, of the Space Telescope Science Institute in Baltimore, Maryland, said at a press conference this month.
Fox presented the new Hubble observations at the 225th meeting of the American Astronomical Society in Seattle, revealing the , and agethe Fermi bubbles.
Piercing the Dust and Gas
Fermi bubbles were first discovered in 2010 by scientists using NASA’s Fermi Large Area Telescope, which revealed two lobes of material protruding from the center of the Milky Way. Since then, the features have been studied in the X-ray and radio wavelengths.
Fox and his team paired Hubble's Cosmic Origins Spectrograph with a distant quasar to measure the speed and composition of the billowing bubbles. A quasar is a very bright source of light generated by fast-moving particles near a supermassive black hole inside a distant galaxy. Light from the quasar is so strong that it outshines its parent galaxy. The scientists measured how the ultraviolet light from quasar PDS 456 shifted as it passed through the base of the northern bubble.
With the help of the bright quasar, the team determined that material on the near side of the northern lobe is streaming toward the sun, while material on the far side is zipping away. The material is gushing out of the Milky Way at approximately 900 to 1,000 kilometers per second, or about 2 million mph.
At this rate, the scientists calculated that the event that created the lobes occurred between 2.5 and 4 million years ago.
The gas studied by Fox's team reaches temperatures of 17,500 degrees Fahrenheit (9,700 degrees Celsius). Far cooler than the rest of the gas in the outflow, which reaches temperatures of around 18 million degrees F (10 million degrees C), the cooler gas may be interstellar gas from the Milky Way that has been swept up in the hot outflow, Fox said.
A Front-Row Seat
In other galaxies, starbursts drive outflows of gas that resemble Fermi bubbles, but these features are difficult to study from so far away. The Milky Way's Fermi bubbles provide an up-close look at these formations.
"We have a front-row seat. We can study the details of these structures," Fox said in a statement. "We can look at how big the bubbles are and how much of the sky they are covering."
PDS 456 is the first of 20 quasars whose light passes through the lobes. Studying the entire sample will allow astronomers to further narrow down the source of the event that generated the Fermi bubbles.
One potential cause of the outflows is rapid star formation at the galactic center. This birth of stars produced a series of supernovas that blew out a significant supply of gas. Another explanation involves the fall of a star or group of stars into the supermassive black hole at the center of the galaxy, causing superheated gas to be blasted into space.
Whatever the cause, the short-lived nature of the bubbles (when compared with the 13.2-billion-year-old age of the galaxy) suggests that they may be repeating phenomena, occurring frequently throughout the life of the Milky Way.
Read more at Discovery News
“We’ve looked at hundreds of thousands of quasars at this point, and now we’ve found one that has switched off,” said astronomer C. Megan Urry, the study’s principal investigator. “This may tell us something about their lifetimes.”
Quasars are extremely bright galaxies driven by very active supermassive black holes in their cores. In the early universe, quasars dominated, so astronomers use these objects as a means of understanding how the early universe, and the galaxies it contained, formed.
By comparing observations of the same quasar a few years apart, Urry and her team found that the quasar dimmed by up to 7 orders of magnitude. This suggests something changed with the black hole driving the quasar — potentially a change in diet.
“This is like a dimmer switch,” said associate researcher Stephanie LaMassa. “The power source just went dim. Because the life cycle of a quasar is one of the big unknowns, catching one as it changes, within a human lifetime, is amazing.”
The quasar in question is embedded in the Stripe 82 region along the Celestial Equator and the researchers noticed the dimming event was accompanied by a weakening of the quasar’s broad emission lines. These emission lines, that can be detected in optical wavelengths, are generated by surrounding clouds of gas being ‘excited’ or energized by the radiation from the quasar itself. This radiation is generated by material falling into the black hole, so the weakening of the emission lines suggests the black hole in the quasar’s core has stopped consuming matter.
Read more at Discovery News
|A male strepsiptera mates with a female embedded in a wasp. He’s far more beautiful than her, for she’s a wingless, legless sack of eggs. But it’s what’s inside that counts, and what counts for this insect is…well lots of eggs I guess.|
But with all due respect to human mothers out there, their sacrifice is nothing compared to a momma strepsiptera. (Cue phone call from my own mother in 3…2…1…) This little parasite invades the bodies of all manner of insects, where she waits patiently as the young that fill her body consume her from the inside out. Eventually they erupt out of their sacrificial mother and emerge from the still very much alive host insect into the light of day—as many as a million of them in one particularly large species that parasitizes big grasshoppers. Yeah, you can go ahead and throw away that “Mother of the Year” mug now.
The 600 or so species of strepsiptera are some of the cleverest, most brutal parasites on Earth. Unlike a lot of parasites out there, they have no interest in keeping their host alive for very long: They use them, abuse them, and explode out of their bodies, leaving gaping wounds that haven’t the slightest chance of healing. And their life cycle must be one of the strangest and most wonderfully complex among all parasites.
Importantly, though, the one thing she does have are naughty bits: the oviduct. This she sticks out of the hole in her host’s exoskeleton and emits a pheromone, and the males come running. They’ll inseminate her right there on the host. You may read elsewhere that like bed bugs, strepsiptera are “traumatic inseminators,” with males stabbing into females and fertilizing the eggs through her flesh. That’s wrong, Kathirithamby stresses—insemination happens right in the exposed oviduct. So…lucky for the female, I guess?
|This is what it looks like to have multiple female strepsiptera poking their oviducts out of your body.|
The larvae will emerge from their mother in batches as their poor host continues to crawl or fly around, spreading out little nightmares for any nearby ant or wasp hives. Yet getting there is no easy task for such tiny creatures. They have legs, so they’re definitely mobile, but instead of scrambling their way to a nest they’ll cling to an adult member of the colony and hitchhike. “They actually have to be carried to the nest by a foraging worker, an ant or a wasp or a bee,” said Kathirithamby. “And when they’re taken to the nest they get onto the egg or the larvae of the host.”
Weirder still, when the strepsiptera bores into the host larva, which can take two days, it never leaves a mark. It’s likely using some kind of enzyme that dissolves the host’s cuticle, but how it does so without leaving any visible signs of trauma is a mystery. Plus, once it gets in there and develops into a male, it’ll actually allow the host larva to grow into an adult, maturing along with it in a strange kind of Calvinist predestination—the host is doomed to a horrible death right from birth. That’s real goofy, because normally the insect’s immune response would form a capsule around any foreign objects in the body cavity. But Kathirithamby never sees that happening to the strepsiptera. They do seem to wrap themselves in the inner layer of the exoskeleton, called the endocuticle, which could help them remain unnoticed.
So the male strepsiptera grows big and fat in its own little vehicle. “They need that because they want the host to be alive and moving,” and therefore be better able to disperse in the ecosystem, Kathirithamby said. And “in spite of almost the whole abdominal segment being occupied by the strepsiptera, the host is still able to move around.”
The females typically go about development a little bit differently. While the larvae that will eventually become males hitchhike to their hosts, the larvae that will become their sisters stick around closer to their mother. Ideally, her host—perhaps a cricket—would have recently had its own nymphs, which the strepsiptera larvae climb into, develop into females, and begin the whole horrifying process anew.
Read more at Wired Science
Jan 22, 2015
Jellyfish can detect the direction of ocean currents and swim strongly against them, according to the study, which is published in the latest issue of the journal Current Biology. The research adds to the growing body of evidence that creatures without brains, such as carnivorous plants, can still be clever.
“Detecting ocean currents without fixed visual reference points is thought to be close to impossible and is not seen, for example, in lots of migrating vertebrates including birds and turtles,” co-author Graeme Hays of Deakin University in Australia said in a press release.
“Jellyfish are not just bags of jelly drifting passively in the oceans,” he added. “They are incredibly advanced in their orientation abilities.”
The following video shows how jellyfish swim. The speed of the undulations can go much faster than this, depending on the ocean currents.
The data from those devices showed that jellyfish sometimes actively swim against currents in response to drift. In short, they seem to control their destinations, as opposed to just passively drifting around their ocean habitats.
Jellyfish can be pesky creatures, as they sometime form “blooms,” which are essentially swarms of jellyfish that suddenly appear at ocean surfaces. The new research helps to explain how these blooms form, with hundreds to millions of individuals swimming to certain locations and staying there for up to several months.
Now the mystery is: without a brain, how are jellyfish so "smart?"
Fossette and Hays theorize that the animals detect ocean current shear across their body surface, or they may detect Earth’s magnetic field or infrasound, both of which can be used for orientation.
Knowing where jellyfish are, and where they’re going, is helpful info for us and other animals. Jellyfish serve as important prey for many species, such as leatherback sea turtles. In their case, finding a jellyfish is great. Fishermen and human beachgoers aren’t so thrilled, given that jellyfish can clog fishing nets and sting bare feet and legs.
Read more at Discovery News
Braided like a pigtail with the end jutting forward, the beard was reportedly detached from the over 3,300-year-old mask during a cleaning incident last October at the Egyptian Museum in Cairo, where the artifact is one of the top attractions.
A museum employee, who asked for anonymity for fear of reprisals, told Al Araby Al Jadeed that the beard was unintentionally severed from the chin during ordinary dusting.
Three of the museum’s conservators confirmed the incident to the Associated Press, although they gave different accounts as to whether the beard was knocked off during cleaning or was removed because it was loose.
They all agreed that the beard was glued back on improperly.
Rather than following the regular procedures reporting the damage to the Ministry of Antiquities and send the priceless artifact to the restoration lab, someone opted for a DIY procedure, Al Araby Al Jadeed wrote.
The beard was fixed with quick drying epoxy that cannot unstuck given its very high adhesive property. Indeed, the material is used for attaching on metal or stone.
Moreover, the glue was used abundantly, causing it to dramatically flow along the beard and chin.
According to the Arabic news site, which has published a picture to show “the presence of a foreign substance between the mask and chin,” it was then decided to remove the residue adhesive with a spatula, only doing more damaging as scratches are now visible.
Read more at Discovery News
The study, published in the latest issue of the journal Science, challenges the long-standing assumption that Homo habilis, a.k.a. "Handy Man," was the first crafter of stone tools.
"Instead, I think our findings show that the traditional view that stone tool use was something that only members of our own genus Homo were capable of is outdated," senior author Tracy Kivell told Discovery News, explaining that stone tool usage "goes back much earlier -- long before the appearance of Homo -- than we originally thought."
Kivell, a paleoanthropologist at the University of Kent and the Max Planck Institute for Evolutionary Anthropology, lead author Matthew Skinner, and their colleagues came to that conclusion after analyzing bones from Australopithecus hands from the Pliocene Epoch, approximately 5.3-2.6 million years ago.
Australopithecus individuals had a mixture of ape and human features. They sported foot and leg bones suited for walking upright, but had long arms appropriate for tree climbing.
The researchers found that Australopithecus africanus had human-like hands that were capable of precision grips, such as squeezing small objects. These early members of the human family tree also had an opposable thumb. The hand features likely evolved from even earlier human ancestors that possessed long fingers and short thumbs, which facilitate maneuvering in trees.
Prior studies have found that both making and utilizing stone tools by hand requires forceful, precision-pinch grips. Since A. africanus could use its hands in such a way, logic holds that they were indeed making stone tools, but where are the tools?
That is now a big mystery, because the earliest known stone tools date to after A. africanus lived.
"The first recognizable stone tools consist of stone pebbles and simple flakes and date to about 2.5 million years ago from Ethiopia," Skinner, who is a paleoanthropologist at the University of Kent and the Max Planck Institute for Evolutionary Anthropology, said. "This is also when we start to find animal bones with cut-marks made from stone tools."
"However," he added, "there is some evidence for these type of cut-marks at 3.4 million years ago, a time period only associated with australopiths."
Matthew Tocheri, who is Canada Research Chair in Human Origins at Lakehead University, told Discovery News that the new study makes a convincing case that "australopiths were not only capable of using their hands in more human-like ways than living great apes, but also that they actually used their hands in more human-like ways. That's why the bone (in A. africanus) has remodeled in response to that more human-like hand use."
He suspects that the lack of stone tools in the archaeological record prior to 2.5 million years ago suggests that the tools were not as adaptively important to A. africanus as they were to later humans.
Brian Richmond, a curator in the Division of Anthropology at the American Museum of Natural History, said, "With this study, we finally have evidence of what we long suspected--australopiths used their human-like hand proportions to handle objects in human-like ways."
Richmond further said that the study raises many new questions, and not just about the missing tools. For example, he wonders if all australopiths had human-like hands, or if it was just A. africanus. Also, he is curious if the bones provide evidence for frequent, or infrequent but high-intensity, hand activity.
Read more at Discovery News
The first batch of science papers reveals details of Comet 67P/Churyumov-Gerasimenko, which is approaching the sun accompanied by the orbiting Rosetta spacecraft. After a 10-year journey, Rosetta put itself into orbit around Comet 67P in August and three months later released a lander to its surface.
So far, the most surprising finding is that analysis of the comet’s water shows it is chemically different from water in Earth’s oceans, challenging a long-held theory that crashing comets brought water to Earth and other planets in the inner solar system. That discovery was released in December, in advance of seven papers published in a special issue of this week’s Science.
The new studies show wide variation in where gases are being released from the comet’s twin-lobed, duck-shaped body. The information is important for understanding what processes the comet has been through and continues to undergo since its formation some 4.6 billion years ago.
Scientists believe comets are primordial bodies leftover from the solar system’s planet-forming days. The primary purpose of the Rosetta mission is to learn more about the birth of the solar system by studying the comet close up.
The Rosetta team is hoping to work out whether 67P originally was two bodies that melded together, forming the oddly shaped nucleus that exists today. The other option is the neck feature of the comet’s duck-shaped body was eaten away over time from what was a more symmetrically shaped, single structure
“We don’t know the answer to that yet,” astronomer Michael A’Hearn, with the University of Maryland, told Discovery News.
“If we see significant differences between the two lobes in composition – that are not just a seasonal effect – they we may be able to say something about how the pieces moved around when the comets were forming, how the larger components, the 100 meter-and-up pieces, came together to form a nucleus. That’s a rather open questions at the moment,” A’Hearn said.
Results from the first two months of Rosetta’s mission indicate the comet’s mass is roughly 100 million times the mass of the International Space Station, with a bulk density similar to cork, wood or aerogel, Science said in an overview of the newly published research.
That would mean that 67P’s nucleus has an internal structure that is fluffier and more porous than computer models previously predicted.
The new research shows the comet’s body is covered with organic materials, but not much surface ice. Scientists expected to see complex carbon-containing molecules such as alcohols and carboxylic acids. So far, however, the surface instead seems to be dominated by simpler hydrocarbons, a finding that may have implications for understanding how carbon-based molecules formed and spread through the solar system, one of the Science papers reports.
Read more at Discovery News
Jan 21, 2015
Using a powerful X-ray procedure, Italian researchers have been able to read letters hidden inside two carbonized papyri without unrolling them.
"It's the first time a technology achieves such a result," Vito Mocella, a physicist from the National Research Council's Institute for Microelectronics and Microsystems (CNR-IMM) in Naples, told Discovery News. "Until now, imaging techniques have been unable to view the carbon-based ink of these papyri, even when they could penetrate the different layers of their spiral structure."
The scrolls used by Mocella's team were excavated 260 years ago from the Villa of the Papyri in Herculaneum, a magnificent seafront estate perhaps owned by Lucius Calpurnius Piso, Julius Caesar's father-in-law.
The villa housed one of the finest libraries of antiquity. Consisting mainly of Epicurean philosophical texts, the scrolls were carefully stored in shelves covering the walls.
During the devastating eruption of Mount Vesuvius, the scrolls, as well as the Herculaneum citizens, were burned by a furnace-like blast of hot gas.
Paradoxically preserved forever (Herculaneum's seaside air would have destroyed them) the scrolls are now stored at the National Library of Naples. They make up the only library known to have survived the ancient world. The carbonized scrolls are thought to hold Aristotle's lost 30 dialogues, philosophical work by Epicurus, erotic poems by Philodemus, Virgilius's lost eclogue, scientific work by Archimedes and lesbian poetry by Sappho.
Out of the 1,785 scrolls discovered during the 18th century excavation, only 585 had been completely unrolled using a 18th century mechanical method, while 209 have been partly unrolled.
About 400 have never been unrolled and 450 are so difficult to read that their text remains unknown.
"These carbonized papyri are extremely fragile and are inevitably damaged or destroyed in the process of trying to open them to read their contents," Mocella and colleagues wrote in the journal Nature Communications.
Any attempt using non invasive procedures to read the scroll, including multi-spectral technology, have proven ineffective.
The ink used to write the texts was the main barrier.
"Multi-spectral imaging has improved the readability of these texts considerably, but unfortunately it is not applicable to texts that remain rolled-up," Mocella said.
"In antiquity, papyri were written using a black carbon-based ink obtained from smoke residues, the density of which is almost the same as that of the carbonized papyrus," the researchers wrote.
Until now, therefore, it has appeared impossible to distinguish ink from papyrus inside a scroll using conventional X-ray techniques.
To overcome the problem, Mocella and colleagues turned to X-ray phase contrast tomography (XPCT), a 3-D X-ray imaging technique most commonly used in medicine.
The technology takes advantage of subtle differences in the way X-rays pass through different substances, in this case papyrus and ink.
"Papyrus writing material consisted of two layers, whose fibers ran perpendicular to one another; the scribe would usually write the text in vertical columns on the side of the papyrus sheet where the horizontal fibers were uppermost," the researchers wrote.
They noted that carbon-based ink did not penetrate into the papyrus fibers, but sat atop them, producing a slight thickness on the surface.
"As we shall see, this fact proved to be crucial for our experiments," Mocella said. "Once amplified by phase contrast technique, that relief, about some 100 micron thick, made it possible to read some letters."
Using the technology at the European Synchrotron Radiation Facility in Grenoble, France, the team examined two scrolls -- one unrolled and the other still rolled-up -- which were handed to Napoleon Bonaparte as a gift in 1802 and now belong to the collection of the Institut de France.
On the unrolled scroll the researchers identified two words written in several superposed layers of papyrus. On one of the hidden layers, the sequence of Greek capital letters PIPTOIE, possibly meaning "would fall," could be read, while another sequence, EIPOI, meaning "would say," was spotted in the following line.
But the main object in Mocella's investigation was a carbonized, sausage-shaped rolled-up papyrus.
"The tremendous pressure of the pyroclastic material compressed the scroll and deformed its internal spiral structure, the layers of which are folded in a nearly chaotic and badly entangled fashion," the researchers said.
The letters were likely distorted, making data analysis a real challenge.
Nevertheless, the scanner was able to pick out all 24 letters of the Greek alphabet. The researchers not only identified some words such as "deny," "for," "the" and "to move," but also pinpointed a specific handwriting style, which led to the likely author, the Greek philosopher and poet Philodemus.
"While our ﬁrst experiments have revealed only small segments of writing and are in need of further reﬁnement, we note that once the XPCT technique has been tuned, the imaging of an entire papyrus scroll should not require more than a few hours of synchrotron beam time," Mocella said.
Read more at Discovery News
At present, the oldest surviving copies of the gospel texts date to the second century (the years 101 to 200).
This first-century gospel fragment was written on a sheet of papyrus that was later reused to create a mask that was worn by a mummy. Although the mummies of Egyptian pharaohs wore masks made of gold, ordinary people had to settle for masks made out of papyrus (or linen), paint and glue. Given how expensive papyrus was, people often had to reuse sheets that already had writing on them.
In recent years scientists have developed a technique that allows the glue of mummy masks to be undone without harming the ink on the paper. The text on the sheets can then be read.
The first-century gospel is one of hundreds of new texts that a team of about three-dozen scientists and scholars is working to uncover, and analyze, by using this technique of ungluing the masks, said Craig Evans, a professor of New Testament studies at Acadia Divinity College in Wolfville, Nova Scotia.
"We're recovering ancient documents from the first, second and third centuries. Not just Christian documents, not just biblical documents, but classical Greek texts, business papers, various mundane papers, personal letters," Evans told Live Science. The documents include philosophical texts and copies of stories by the Greek poet Homer.
The business and personal letters sometimes have dates on them, he said. When the glue was dissolved, the researchers dated the first-century gospel in part by analyzing the other documents found in the same mask.
One drawback to the process is that the mummy mask is destroyed, and so scholars in the field are debating whether that particular method should be used to reveal the texts they contain.
But Evans emphasized that the masks that are being destroyed to reveal the new texts are not high quality ones that would be displayed in a museum. Some are not masks at all but are simply pieces of cartonnage.
Evans told Live Science, "We're not talking about the destruction of any museum-quality piece."
The technique is bringing many new texts to light, Evans noted. "From a single mask, it's not strange to recover a couple dozen or even more" new texts, he told Live Science. "We're going to end up with many hundreds of papyri when the work is done, if not thousands."
Scholars who work on the project have to sign a nondisclosure agreement that limits what they can say publicly. There are several reasons for this agreement. One is that some of the owners of these masks simply do not want to be made known, Evans said. "The scholars who are working on this project have to honor the request of the museums, universities, private owners, so forth."
The owners of the mummy masks retain ownership of the papyrus sheets after the glue on them is dissolved.
Evans said that the only reason he can talk about the first-century gospel before it is published is because a member of the team leaked some of the information in 2012. Evans was careful to say that he is not telling Live Science anything about the first-century gospel that hasn't already been leaked online.
Soon after the 2012 leak, speculation surrounded the methods that the scholars used to figure out the gospel's age.
Evans says that the text was dated through a combination of carbon-14 dating, studying the handwriting on the fragment and studying the other documents found along with the gospel. These considerations led the researchers to conclude that the fragment was written before the year 90. With the nondisclosure agreement in place, Evans said that he can't say much more about the text's date until the papyrus is published.
The process that is used to obtain the papyri, which involves the destruction of the mummy masks, has also generated debate. For instance, archaeologist Paul Barford, who writes about collecting and heritage issues, has written a scathing blog post criticizing the work on the gospel.
Roberta Mazza, a lecturer in Classics and Ancient History at the University of Manchester, has blogged her concerns about the text as has Brice Jones, a doctoral candidate in religion at Concordia University.
When the texts are published the debate is likely to move beyond the blogosphere and into mainstream media and scholarly journals.
Although the first-century gospel fragment is small, the text will provide clues as to whether the Gospel of Mark changed over time, Evans said.
His own research is focused on analyzing the mummy mask texts, to try to determine how long people held onto them before disposing or reusing them. This can yield valuable information about how biblical texts were copied over time.
"We have every reason to believe that the original writings and their earliest copies would have been in circulation for a hundred years in most cases — in some cases much longer, even 200 years," he said.
Read more at Discovery News
In 2013, researchers first suggested that long, thin, dense clouds of gas may form inside the spiral arms of the Milky Way, creating a sort of galactic skeleton that traces the shape of these massive structures. At the time, only one such "bone" — known as Nessie — had been identified.
Now, new research presented at the 225th meeting of the American Astronomical Society shows that Nessie is not alone. Catherine Zucker, an undergraduate physics student at the University of Virginia, has dug up six strong candidates for additional galactic bones.
From the Inside, Looking Out
Living inside the Milky Way comes with a disadvantage: Astronomers cannot see what this galactic house looks like from the outside. The Milky Way is a spiral galaxy, meaning multiple "arms" sprout from a central region and then swirl around it, like streams of water spiraling down a drain. These arms coil around each other in a flat plane, so the galaxy is like a pancake: When it's viewed face-on, it is circular, but when it's viewed edge-on, it's a straight line. The Earth is nestled inside this pancake, toward the outside of the disc. As a result, the Milky Way appears as a ribbon running down the middle of the night sky.
The sun and the Earth are elevated just slightly above the galactic plane, giving scientists a small boost when they're trying to look at the larger galactic structure (like a kid on an adult's shoulders, trying to see over a crowd). Scientists have identified the large spiral arms that make up the galaxy, but there is still debate about the exact location of those arms, as well as the location of smaller spirals that branch off of the larger ones.
But the "bones" that scientists have now identified — long, thin, highly dense clouds of gas that can also be identified by the light they absorb — would be significantly easier to spot, and could help scientists create a more precise sketch of what the Milky Way looks like from the outside.
"It's a really new field of study," Zucker told Space.com at the AAS meeting in Seattle, where she presented a poster featuring her work on the galactic skeleton. When Zucker started her work, the gas cloud known as "Nessie" was the only object of its kind that had been identified, and the only candidate for a bone. "What I was trying to do was basically prove that the Nessie filament wasn't some curiosity, wasn't a fluke — that there are other filaments out there similar to Nessie that can trace galactic structure."
Zucker started looking through images of the galaxy taken by various telescopes, including the Spitzer Space Telescope. She found 15 long, thin gas clouds that looked like they could be galactic bones.
There were six initial criteria for a galactic bone. For example, it must lie mostly parallel to the plane of the galaxy and be associated with a known spiral arm — Nessie appears to trace the spine of the Scutum-Centaurus Arm, one of the largest arms in the Milky Way. A bone must also be more than 50 times longer than it is wide — Nessie is more than 300 times longer. Zucker also had to make sure she was seeing a single cloud and not multiple clouds in the same line of sight.
With her list of criteria, Zucker identified 10 candidate bones, six of which met the entire list of requirements. She spelled out her conclusion on her poster: "Nessie is not a 'curiosity' -- other bones exist."
Read more at Discovery News
Through the careful analysis of ocean sediment, tiny particles that originated from deep space have settled on the seabed, locking the chemical secrets to supernova processes that would have otherwise remained a mystery.
“Small amounts of debris from these distant explosions fall on the earth as it travels through the galaxy,” said lead researcher Anton Wallner, of the Australian National University. “We’ve analyzed galactic dust from the last 25 million years that has settled on the ocean and found there is much less of the heavy elements such as plutonium and uranium than we expected.”
Supernovae are powerful explosions triggered when massive stars reach the ends of their lives. During these powerful events, many elements are forged, including elements that are essential for life to thrive — such as iron, potassium and iodine.
However, as pointed out by an Australian National University press release, even heavier elements like lead, gold and radioactive elements like uranium and plutonium can be created. But it appears that the formation processes for the heaviest elements are at odds with current astrophysical theory.
Wallner and his team studied samples of sediment from the bottom of a stable area at the bottom of the Pacific Ocean. But when measuring the quantities of plutonium-244, a radioisotope that is produced by supernovae, they found something strange in their results — there was 100 time less plutonium-244 than predicted.
Plutonium-244 has a half-life of 81 million years, making it an excellent indicator of the number of supernovae that have exploded nearby in recent galactic history. “So any plutonium-244 that we find on earth must have been created in explosive events that have occurred more recently, in the last few hundred million years,” said Wallner.
Read more at Discovery News
|According to the theory of physiognomy, this man in Giambattista della Porta’s De Humana Physiognomonia would behave like a dog because he looks like one. Kinda like Teen Wolf, only without the sick Ray Bans.|
It’s patently silly, but in a way it isn’t. We’re evolutionarily programmed to read our peers’ faces. For instance, a scowling, red-faced raging person is probably best avoided, if not getting roughed up is in your best interest. Good judgement could mean the difference between falling victim to a dangerous character and rightly keeping your distance and escaping unharmed. Not that I was afraid of the old lady. I want to be very clear about that.
A couple thousand years ago some folks were apparently so worried about all this that they thought up a little something called physiognomy—the “art” of reading a human’s personality in their face. Bird-like features meant a bird-like personality, and by using this system you could figure out who to avoid without even speaking to them. But this was no fringe movement: Charles Darwin himself was judged by the physiognomist captain of the Beagle and nearly barred from the voyage. And if you can believe it, there are still physiognomists out there practicing this bunk and charging people for it, making outrageous claims like you can tell if a person is wealthy or not by their nose (I’m not kidding—oh how I wish I were kidding). Weirdly, though, there may be a tiny bit of truth to ascribing certain personality traits to certain physical traits.
But first: a brief, weird history of physiognomy.
It was the ancient Greeks who pioneered the practice of physiognomy. None other than Pythagoras apparently “‘physiognomized’ the young men who presented themselves for instruction,” wrote the Roman writer Aulus Gellius, meaning that he inquired “into the character and dispositions of men by an inference drawn from their facial appearance and expression, and from the form and bearing of their whole body.”
The idea was that if you looked like an animal, say, a sheep, you also had its personality. And according to Jodie Jenkinson in her essay “Face Facts: A History of Physiognomy from Ancient Mesopotamia to the End of the 19th Century,” the theory “served a dual purpose, providing a measure for diagnosing illness and delineating character, as well as establishing a method for divination”—that is, predicting someone’s future—“based on physical appearance.”
|I’ve got this feeling that Giambattista doesn’t particularly like what I’m writing about him.|
Mercifully, physiognomy was widely discredited by the end of the 1600s. But that didn’t stop a few rogue characters from continuing to explore it. In the 18th century a pastor named Johann Casper Lavater wrote a massive four-volume work on physiognomy, arguing that “one could better love one’s neighbor by classifying him according to his facial features.” For Lavater, who was apparently never told that it’s what’s inside that counts, physical beauty was an indication of moral beauty. He figured you could also read the wrinkles and creases in someone’s face, much like a psychic would read your palm.
|Cesare Lombroso thought that you could tell a born criminal by their facial features. Oddly enough, he mostly chose ones that he himself didn’t have. Go figure!|
And physiognomy even came damn close to altering the course of human history. Charles Darwin very nearly didn’t sail on the now-famous voyage of the Beagle—which informed his theory of evolution by natural selection—because the ship’s mercurial captain, Robert FitzRoy, didn’t like Darwin’s nose. “He was an ardent desciple [sic] of Lavater,” Darwin later wrote, “and was convinced that he could judge a man’s character by the outline of his features; and he doubted wheather [sic] anyone with my nose could possess sufficient energy and determination for the voyage. But I think he was afterwards well-satisfied that my nose had spoken falsely.”
You’d think that with such a rotten track record, physiognomy would be extinct today—and you’d be wrong. Take, for instance, the dazzling display of delusion embedded below. Not only does a physiognomist seriously suggest on national TV that you can judge character based on facial features, but that you can use physiognomy to determine how wealthy a man is before you start dating him. “The nose is the key,” she says. “And the larger the nose, the more spiritual or financial abundance. Mother Teresa of Calcutta for example had a huge nose.” I couldn’t make this up, folks.
Here’s the weird thing, though. Several studies have found that there is a bit of correlation between how people judge faces and how the owners of those faces score on personality tests, though only for a limited number of factors like extroversion and conscientiousness. When shown pictures of faces, for instance, students have correctly judged the person’s personality more often than you’d expect with pure chance.
Part of what may be at work here is testosterone. Men with higher levels of the hormone, and therefore a higher propensity for aggression, tend to have rounder, wider, more “masculine” faces. While studies have shown that women prefer such faces in their mates—perhaps because they indicate good, strong, scrappy genes—we may also be evolutionarily programmed to be wary of these types of men. Thus would a snap judgement that a wide-faced man is aggressive be potentially true. It’s not sure-fire, of course, because anyone regardless of testosterone levels can turn out to be aggressive or not aggressive, but it shows that there may just be a little truth in judging people based on their faces.
|Aw, that face. That mugshot. That trail of carnage Al Capone left in his wake.|
The problem is, it can also work the other way around. A man with a baby face—Al Capone, for example—could subconsciously push back against the characterization of submissiveness and become a murderous bastard. (I’m not suggesting Al Capone became a murderous bastard because someone pinched his cheeks. It’s just a hypothetical.) Same goes for a more masculine-looking guy. Sick of being pegged for a meany-head, he could instead play nice.
Read more at Wired Science
Jan 20, 2015
Reported in the journal Nature Geoscience, the research illustrates how meteorites -- often portrayed as portents of doom and destruction -- may actually have been key to the development of life on Earth.
Scientists have long puzzled over the origin of Earth's nitrogen because it has a different isotopic composition to nitrogen produced by the sun, and is also different to the nitrogen found in comets.
"For a long time there had been a theory that comets brought water and nitrogen to Earth, but there is growing evidence that the isotopic ratios in comets are very different to that in Earth's atmosphere," said the study's lead author Dennis Harries of the Friedrich-Schiller-Universität in Jena, Germany.
The authors used an electron microscope to study crystals from two ancient carbonaceous chondrite meteorites named Yamato-791198 and Yamato-793321 which were recovered from Antarctica in 1979. They discovered an unusual mineralized form of nitrogen which matched Earth's nitrogen.
"We found nitrogen with a similar isotopic composition to nitrogen found in people and in Earth's atmosphere, in a very unusual mineral which was detected in two meteorites," said Harries. "This mineral shows us that there was another type of nitrogen in the early solar system billions of years ago, and this molecule was probably responsible for making the building blocks of life and bringing the nitrogen of our atmosphere to Earth."
"The discovery of this mineralized form of nitrogen is telling us something about how Earth got its nitrogen."
The meteorites examined by the authors contained a strange mineral called carlsbergite which is a compound of chromium and nitrogen.
"That's unusual because nitrogen is usually found as a gas in our atmosphere and is reluctant to enter mineral crystal structures," said Harries.
The authors discovered the carlsbergite by using an electron microscope to study crystals from the meteorites,
"The crystals we're looking at are only 100 nanometers in size, so they're not visible to the naked eye," said Harries.
They then used mass spectrometry to measure the isotopic composition of the nitrogen atoms in these very small mineral grains.
How it formed
Harries believes there were high concentrations of ammonia in some parts of the solar nebula which formed the Sun and solar system 4.6 billion years ago. Under the right conditions, nitrogen can be produced out of molecules of ammonia.
"We think the ammonia was locked up with water in ices and was somehow evaporated by shock waves, or by collisions of small bodies near the inner solar system," said Harries.
This generated extremely high temperatures causing the ammonia to react with minerals, forming carlsbergite.
Harries speculates that the asteroids containing carlsbergite were flung into the inner solar system by gravitational perturbations caused by changes in the orbit of Jupiter early in the solar system's history. Eventually some of these asteroids impacted the Earth.
Most of the original bodies containing these ices would now be gone, but Harries thinks some ice could still be found when NASA's Dawn spacecraft enters orbit around the main asteroid belt dwarf planet Ceres on March 7, 2015
Read more at Discovery News
Smith published ”A Geological Map of England and Wale and Part of Scotland.” On a scale of 5 miles per inch, the map measured 6 feet by 8 feet 6 inches, and it was the first map that showed a detailed, multicolor three-dimensional depiction of the varieties of soil and layers of rock under a large area, as well as the location of mineral wealth and fossils. Smith used watercolors and devised an innovative shading technique that is still used in geological maps.
According to this biographical profile of Smith, the map’s creator was born in 1769 and grew up on his uncle’s farm, where as a child he became fascinated with what people called “poundstones,” which actually were ancient fossilized sea urchins. As a young man, he began working as a surveyor in coal mines, where he observed rock layers in predictable sequences and began to suspect that the strata extended across the countryside.
He gathered further evidence of his notion as he traveled around England, working as a surveyor on the canals that were being dug to transport the coal. He also discovered that different layers had different fossils in them. That led Smith to develop the principle of faunal succession, which is still used by scientists today to identify various rock strata.
The conceptual breakthrough inspired him to create his famous map.
While Smith’s work earned him a place in history, oddly, it also contributed to his financial ruin. Though he made a lot of money as a surveyor, Smith invested unwisely in real estate, and got so heavily into debt that he had to sell his famed collection of fossils to the British Museum. The map was a chance for him to get in the black again, but it didn’t sell well enough, in part because another surveyor published his own competing version. As a result, the creator of the first great geological map ended up in debtor’s prison in 1819.
From Discovery News
She later explained her experience to researchers who were conducting a survey about sleep paralysis, a common but somewhat unexplained phenomenon in which a person awakens from sleep but feels unable to move. Up to 40 percent of people report experiencing sleep paralysis at some point in their lives, and a few, like Salma, hallucinate shadowy intruders hovering over them.
"Sleep paralysis can be a very frightening experience for some people, and a clear understanding of what actually causes it would have great implications for people who suffer from it," said Baland Jalal, a neuroscientist at the University of California, San Diego.
Researchers say that sleep paralysis happens when a person awakens during a stage of sleep known as rapid eye movement (REM). People in this stage of sleep are usually dreaming, but their muscles are nearly paralyzed, which might be an evolutionary adaptation that keeps people from acting out their dreams.
It is harder to explain why a subset of people who experience sleep paralysis feel a menacing figure in their room or pressing on their chests.
One possible explanation could be that the hallucination is the brain's way of clearing out confusion, when there's a disturbance in the brain region that holds a neural map of the body or the "self," according to a recent article that Jalal and his colleague Vilayanur Ramachandran, of UC San Diego, published in the journal Medical Hypotheses.
"Perhaps, in part of the brain, there's a genetically hardwired image of the body — a template," Jalal told Live Science. Previous studies have suggested that such a region may be a part of the parietal lobes, which are situated in the top-middle part of the brain.
It is possible that during sleep paralysis, the parietal lobes monitor the neurons in the brain that are firing commands to move, but aren't detecting any actual movement in the limbs, which are temporarily paralyzed. This may lead to a disturbance in how the brain builds a sense of the body image, Jalal said. The appearance of a bedroom intruder could result when the brain tries to projectthe person's own body image onto a hallucinated figure, he said.
This idea, though intriguing, would be very difficult to test, Jalal said. One way to gather evidence showing whether this is what is happening inside the brain during sleep paralysis would be to test people who have different body images. For example, if this idea is true, people who are missing a limb might hallucinate figures who are missing the same limb, Jalal said. Still, people with such different body images are likely a small subset of the population, and it would be difficult to conduct such an experiment, he said.
It's also possible that people's differing experiences of sleep paralysis are due to differences in their cultural beliefs. Previous research has suggested that certain ideas found in people's cultures could shape how they experience certain phenomena, Jalal said.
For example, in a 2013 study published in the journal Cultural, Medicine, and Psychiatry, Jalal and his colleague Devon Hinton, of Harvard Medical School, looked at the rates of sleep paralysis, and the amount of stress that people felt because of the episodes, among people of two different societies: Egypt and Denmark. They found that, compared to study participants in Denmark, the Egyptians experienced sleep paralysis more frequently, and had more prolonged episodes that were accompanied with a greater fear of dying from the experience.
"These are two very different cultures; Egypt is very religious, whereas Denmark is one of the most atheist countries in the world," Jalal said.
Most of the Danish participants said they thought sleep paralysis was caused by physiological factors, brain malfunctioning or sleeping the wrong way, whereas the Egyptians were more likely to believe that sleep paralysis is caused by the supernatural.
In another survey, about half of the Egyptian participants from that study said they thought their sleep paralysis was inflicted by a jinn, a ghostlike, menacing creature from Islamic mythology, according to the study, published in the journal Transcultural Psychiatry in 2014.
Jalal and his colleagues concluded that people with such supernatural beliefs tend to experience more fear during sleep paralysis, as well as longer episodes of it. It is even possible that the fear actually contributes to an increase in the person's severe episodes of sleep paralysis, and vice versa, Jalal said.
Read more at Discovery News
There are dozens of people who have claimed to visit heaven (or, less often, hell) during near-death experiences.
The best-selling 2010 book “The Boy Who Came Back From Heaven” tells the story of one young boy’s near-death experience: “In 2004 Kevin Malarkey and his six-year-old son, Alex, suffered a terrible car wreck. The impact from the crash paralyzed Alex, and it seemed impossible that he could survive.
“When Alex awoke from a coma two months later, he had an incredible story to share. Of events at the accident scene and in the hospital while he was unconscious… Of the angels who took him through the gates of Heaven itself.”
It was one of two bestselling books about young boys’ experiences in heaven that came out that year; the other, Colton Burpo’s “Heaven is For Real,” was made into a 2014 film.
Colton Burpo’s experiences in heaven may or may not be for real, but Alex Malarkey admits that his is not. The website PulpitandPen.org noted that the book’s publisher “Lifeway has been selling ‘The Boy Who Came Back From Heaven’ for many years now. It is part of the trifecta of books on ‘heavenly tourism’ that Lifeway has sold and has promoted, along with ’90 Minutes in Heaven’ and ‘Heaven is for Real.’
The co-author of ‘The Boy Who Came Back From Heaven’ — the boy himself — has written an open letter to Lifeway and admonished them for not holding to the sufficiency of Scripture, and has recanted his tale.”
Malarkey’s statement read in part, “Please forgive the brevity, but because of my limitations I have to keep this short. I did not die. I did not go to Heaven. I said I went to heaven because I thought it would get me attention. When I made the claims that I did, I had never read the Bible. People have profited from lies, and continue to. They should read the Bible, which is enough. The Bible is the only source of truth. Anything written by man cannot be infallible.”
Propheting from Heaven
Of course the beauty of books about heaven, and there are many of them, some written by people who, like Malarkey, survived accidents and others by claimed psychics such as Sylvia Browne, is that nothing you write can be disproven. If a person claims to have had some personal experience with the unproven and unexplained (whether God or ghosts) we must simply take them at their word absent any compelling corroborating evidence.
Part of the reason that Malarkey’s story was so widely believed and accepted among its Christian audience is that it reinforced their existing narratives and beliefs. If he had described heaven as a place that smells like melted cheddar cheese and was populated by winged elephants singing Britney Spears songs, his experiences, however sincerely conveyed, would have been dismissed as drug-induced hallucinations or the product of a fertile imagination.
Though that may or not be any more accurate than stereotyped visions of winged people in robes walking among clouds, by sticking closely to a widely-accepted Christian interpretation of Heaven, God, and demons, Malarkey assured that his story would meet his audience’s expectations and be popular.
Many of these accounts, including Malarkey’s, involve near-death experiences (NDEs) following trauma. However scientists have cast doubt on the reality of many NDEs.
A 2001 article published in “Trends in Cognitive Sciences” by neuroscientist Dean Mobbs, of the University of Cambridge’s Medical Research Council Cognition and Brain Sciences Unit, and Caroline Watt, of the University of Edinburgh, found that “contrary to popular belief, research suggests that there is nothing paranormal about these experiences. Instead, near-death experiences are the manifestation of normal brain function gone awry, during a traumatic, and sometimes harmless, event.”
Mobbs and Watt noted that many classic NDE symptoms are actually reported by people who were never in danger of dying in the first place.
According to “The Washington Post” the book’s publisher, Tyndale House / Lifeway, has announced that it will stop selling the book and issued a statement reading in part, “We are saddened to learn that Alex Malarkey, co-author of ‘The Boy Who Came Back from Heaven,’ is now saying that he made up the story of dying and going to heaven. Given this information, we are taking the book out of print.”
Of course the book has already made millions of dollars for the publisher over the past five years, so removing it from print will not be a financial hardship.
Read more at Discovery News
Jan 19, 2015
The specimen, found by a farmer in China, is of an apparent family group with an adult, surrounded by six juveniles of the same species. Given that the smaller individuals are of similar sizes, the group interpreted this as indicating an adult with its offspring, apparently from the same clutch.
A fossil specimen discovered by a farmer in China represents the oldest record of post-natal parental care, dating back to the Middle Jurassic.
The tendency for adults to care for their offspring beyond birth is a key feature of the reproductive biology of living archosaurs -- birds and crocodilians -- with the latter protecting their young from potential predators and birds, not only providing protection but also provision of food.
This behaviour seems to have evolved numerous times in vertebrates, with evidence of a long evolutionary history in diapsids -- a group of amniotes which developed holes in each side of the skull about 300 million years ago and from which all existing lizards, snakes and birds are descended
However, unequivocal evidence of post-natal parental care is extremely rare in the fossil record and is only reported for two types of dinosaurs and varanopid 'pelycosaurs' -- a reptile which resembled a monitor lizard.
A new study by the Institute of Geology, Chinese Academy of Geological Sciences, Beijing; the University of Lincoln, UK; and Hokkaido University, Japan, presents new evidence of post-natal parental care in Philydrosauras, a choristodere from the Yixian Formation of western Liaoning Province, China. Choristoderes are a group of relatively small aquatic and semi-aquatic diapsid reptiles which emerged in the Middle Jurassic Period more than 160 million years ago.
The team reviewed the fossil record of reproduction in this group using exceptionally preserved skeletons of the aquatic choristoderan Philydrosauras. The specimen was donated to the Jinzhou Paleontological Museum in Jinzhou City four years ago by a local farmer who discovered the skeleton.
The skeletons are of an apparent family group with an adult, surrounded by six juveniles of the same species. Given that the smaller individuals are of similar sizes, the group interpreted this as indicating an adult with its offspring, apparently from the same clutch.
Read more at Science Daily
From the beginning of time, uranium has been part of Earth and, thanks to its long-lived radioactivity, it has proven ideal to date geological processes and deduce Earth's evolution. Natural uranium consists of two long-lived isotopes uranium-238 and the lighter uranium-235. A new study of the global cycle of these uranium isotopes brings additional perspectives to the debate on how Earth has changed over billions of years as revealed in a recently published study in the journal Nature.
From early Earth history, the continental crust (Earth's thick solid outer skin that we live on) has accumulated mass from the underlying hot mantle. Most of the newly formed crust, however, is lost again. At mid-ocean ridges at the bottom ocean, where plates drift apart, new oceanic crust is constantly produced as basaltic rocks when hot volcanic lava emerges from the mantle and solidifies. The oceanic crust moves away from the mid-ocean-ridges and ultimately gets transported back into the underlying mantle through "subduction" at ocean trenches.
Uranium is enriched in the rocks of the continental crust; however, at Earth's surface, different environments over time have influenced its mobility. In an oxygen-free atmosphere, as prevailed on early Earth, uranium stayed immobile in rocks as tetravalent uranium (IV). Only after atmospheric oxygen was formed did uranium become oxidised to its mobile hexavalent uranium (VI). This more mobile uranium may then be released during the weathering and break-down of rocks and transported to the oceans in aqueous form. As the cooling oceanic crust moves away from the mid-ocean-ridges in the oceans, seawater eventually percolates through cracks in its rock and in the process uranium gets incorporated into the oceanic crust, in a similar way that a sponge takes up water.
"The radioactive nature of uranium isotopes has long been key in reconstructing early Earth history, but we now see that they also have another story to tell" explains Morten Andersen, a geochemist in the Department of Earth Sciences at ETH Zurich.
Uranium isotopes form specific signatures
For this work, conducted at the University of Bristol including Morten Andersen (now Earth Science, ETH Zurich) along with researchers from the Durham (UK), Wyoming and Rhode Island (US), used the 'fingerprint' carried in the ratio of the two uranium isotopes.
The specific "fingerprint" derived from the ratio of the uranium isotopes, relates to uranium oxidation processes at Earth's surface. In particular, the researchers found that a higher ratio of uranium-238 to uranium-235 is incorporated into the modern oceanic crust, when compared to the uranium isotope signature found in meteorites. The meteorites represent Earth's "building blocks" and, thus, yield the original uranium isotope composition of Earth as a whole, and also the undisturbed mantle. This uranium isotope "fingerprint" of the altered oceanic crust provides a way to trace uranium that has moved from the surface and back into Earth's interior through subduction.
In order to examine the uranium cycle (and the rock cycle), the researchers analysed mid-ocean ridge basalts (MORBs), the hot volcanic lava that is produced from the upper and well-mixed part of the mantle. The ratio of the uranium isotopes in MORBs can be compared with those found in ocean island basalts in places such as Hawaii and the Canary Islands. These islands are so-called "hot-spots" with lava formed from hot mantle plumes that up-well beneath the oceanic crust. Compared to the MORB mantle, the island basalts are made up of material transported to the surface from a much deeper, less well-mixed, mantle sources.
Heavy uranium from surface to the deep
The isotope ratios for uranium-238 to uranium-235 are significantly greater for MORBs than for ocean island basalts. The ratios are also higher than that found in meteorites. This suggests that the MORBs contain a "fingerprint" of the uranium from the oceanic crust, drawn down from the surface and into the upper part of Earth's mantle through subduction, according to Andersen.
Through convection -- slow movements of material in the upper mantle -- the material was eventually mixed around and carried to the area of the mid-ocean ridges and transported back to the surface in the lavas that make up MORBs.
In contrast, the island basalts' ratios of uranium-238 to uranium-235 correspond to those of the meteorites used in the study and showed that these rocks could not have the same mantle source as the MORBs. The researchers explain that ocean island lavas comes from a deeper, less mixed, mantle source and therefore any uranium added from the surface originates from a much earlier time in Earth's history, when the surface environment was very different from today.
Study co-author Heye Freymuth of the University of Bristol explains: "Although uranium was incorporated into the oceanic crust since the initial rise in atmospheric oxygen about 2.4 billion years ago, the ocean crust did not incorporate higher amounts of uranium-238 as the oceans did not yet have adequate supplies of oxygen."
Only during the second marked increase in atmospheric oxygen content 600 million years ago did the deep ocean become fully oxidised, which allowed the oceanic crust to gain the "fingerprint" of high uranium-238. So, despite the oceanic crust having been transported into Earth's mantle for a long time, the uranium isotope ratio of the subducted oceanic crust first differed from Earth's mantle only after the full oxidation of the oceans.
"An important result of this study is how changing conditions on Earth's surface and the increase of oxygen in the atmosphere influenced the composition of deep Earth. Our results suggest that due to changes over the past 600 million years, uranium was mobilised from the surface, transported into Earth's interior and distributed within the mantle," says Andersen.
Read more at Science Daily