Mar 1, 2014
This arrangement of particles appears disorganized over small distances but has a hidden order that allows material to behave like both a crystal and a liquid.
The discovery came as researchers were studying cones, tiny light-sensitive cells that allow for the perception of color, in the eyes of chickens.
For chickens and other birds that are most active during the daytime, these photoreceptors come in four different color varieties — violet, blue, green and red — and a fifth type for detecting light levels, researchers say. Each type of cone is a different size.
These cells are crammed into a single tissue layer on the retina. Many animals have cones arranged in an obvious pattern. Insect cones, for example, are laid out in a hexagonal scheme. The cones in chicken eyes, meanwhile, appear to be in disarray.
But researchers who created a computer model to mimic the arrangement of chicken cones discovered a surprisingly tidy configuration.
Around each cone is a so-called exclusion region that bars other cones of the same variety from getting too close. This means each cone type has its own uniform arrangement, but the five different patterns of the five different cone types are layered on top of each other in a disorderly way, the researchers say.
"Because the cones are of different sizes it's not easy for the system to go into a crystal or ordered state," study researcher Salvatore Torquato, a professor of chemistry at Princeton University, explained in a statement. "The system is frustrated from finding what might be the optimal solution, which would be the typical ordered arrangement. While the pattern must be disordered, it must also be as uniform as possible. Thus, disordered hyperuniformity is an excellent solution."
Materials in a state of disordered hyperuniformity are like crystals in that they keep the density of particles consistent across large spatial distances, Torquato and colleagues said. But these systems are also like liquids, because they have the same physical properties in all directions.
Read more at Discovery News
The broadest answer is that climate is the backdrop for all weather, so climate change must, by definition, play some role. But the day-to-day, weather related details of that role are still sketchy. It's also still difficult to point to a very broad thing like global climate and tie it directly to a single weather event -- or the frequency and intensity of the storms that have hit the eastern United States this winter.
"This is a speculative and genuinely controversial area of the science," said climate scientist Michael Mann of Penn State University. "There are some leading climate scientists who have provided evidence that climate change may be leading toward more persistent weather anomalies which can, for example, give the sort of extended periods of cold seen in the eastern and central U.S. this year, but at the expense in this case of a very warm western U.S. and unprecedented winter warmth in Alaska, and record warmth in many parts of Europe."
Perhaps one of the most under-reported weather facts this winter is that almost every place except the central and eastern United States has been abnormally warm this winter.
"California has had a drought and Alaska in January was 15 degrees F above normal," said Kevin Trenberth of the National Center for Atmospheric Research. "It's only the East Coast that's cold and that's a relatively small area."
And that frigid air, itself, is always around in the winter. Every winter in the northern hemisphere the Arctic goes dark and the air there gets very cold, explained Trenberth. Whether areas to the south get extreme cold weather depends on how well that frigid polar air is kept in place.
"Either it sits there or somebody opens the refrigerator door and it gets out," Trenberth said.
In recent years the fridge was left open over Europe. This year it's over North America. The flip side to this escape of polar air is that it allows the Arctic to warm up this winter, which is not good for the sea ice that needs to recover from some extreme years of summer time melting.
As for how the fridge door gets left open, one popular scientific hypothesis is that the warming of the Arctic has caused the jet stream to slow and become more meandering. This idea, advanced by Rutgers University climate scientist Jennifer Francis, could be the reason that the loopy patterns form in the polar vortex, which brought deathly cold air to so many parts of the eastern United States. If Francis is right, then there is a rather clear climate change connection to the severe winter weather.
That unusual situation, which starts with warm oceans -- the reservoir of Earth's excess atmospheric heat -- propagates around the world just like El Niño and La Niña.
"So yeah, there are signs that climate change plays a role in all of these things," said Trenberth.
What's also been reported a lot is the idea that that intense cold events have always happened, and always will, but will become less frequent as the earth warms. But how does that jive with the loopy jet stream/polar vortex, which ought to cause more polar leaking?
"The answer is that we may be seeing the consequence of both effects simultaneously," said Mann. "Record cold is on the decrease just about everywhere, and record warmth is on the increase. That is just as we expect to be the case with global warming -- no surprises there. The latest winter in no way contradicts that."
Despite all of the claims about record cold, there wasn't a single location in the United States that broke a record for all-time cold this winter, Mann said. Over the past several summers, on the other hand, there have been many locations around the country. that have broken all-time heat records, he said.
"What is also possible is that persistent weather anomalies (long stretches of unusually cold conditions in some places, typically counterbalanced by long-stretches of unusual warmth somewhere else) could become a bit more common," Mann said.
"The models are unclear on this, and they might not be up to the task of modeling this effect, because it depends on subtle phenomena."
Read more at Discovery News
Feb 28, 2014
In 1996, a group of scientists at Johnson led by David McKay, Everett Gibson and Kathie Thomas-Keprta published an article in Science announcing the discovery of biogenic evidence in the Allan Hills 84001(ALH84001) meteorite. In this new study, Gibson and his colleagues focused on structures deep within a 30-pound (13.7-kilogram) Martian meteorite known as Yamato 000593 (Y000593). The team reports that newly discovered different structures and compositional features within the larger Yamato meteorite suggest biological processes might have been at work on Mars hundreds of millions of years ago.
The team's findings have been published in the February issue of the journal Astrobiology. The lead author, Lauren White, is based at the Jet Propulsion Laboratory. Co-authors are Gibson, Thomas-Keprta, Simon Clemett and McKay, all based at Johnson. McKay, who led the team that studied the ALH84001 meteorite, died a year ago.
"While robotic missions to Mars continue to shed light on the planet's history, the only samples from Mars available for study on Earth are Martian meteorites," said White. "On Earth, we can utilize multiple analytical techniques to take a more in-depth look into meteorites and shed light on the history of Mars. These samples offer clues to the past habitability of this planet. As more Martian meteorites are discovered, continued research focusing on these samples collectively will offer deeper insight into attributes which are indigenous to ancient Mars. Furthermore, as these meteorite studies are compared to present day robotic observations on Mars, the mysteries of the planet's seemingly wetter past will be revealed."
Analyses found that the rock was formed about 1.3 billion years ago from a lava flow on Mars. Around 12 million years ago, an impact occurred on Mars which ejected the meteorite from the surface of Mars. The meteorite traveled through space until it fell in Antarctica about 50,000 years ago.
The rock was found on the Yamato Glacier in Antarctica by the Japanese Antarctic Research Expedition in 2000. The meteorite was classified as a nakhlite, a subgroup of Martian meteorites. Martian meteoritic material is distinguished from other meteorites and materials from Earth and the moon by the composition of the oxygen atoms within the silicate minerals and trapped Martian atmospheric gases.
The team found two distinctive sets of features associated with Martian-derived clay. They found tunnel and micro-tunnel structures that thread their way throughout Yamato 000593. The observed micro-tunnels display curved, undulating shapes consistent with bio-alteration textures observed in terrestrial basaltic glasses, previously reported by researchers who study interactions of bacteria with basaltic materials on Earth.
The second set of features consists of nanometer- to-micrometer-sized spherules that are sandwiched between layers within the rock and are distinct from carbonate and the underlying silicate layer. Similar spherical features have been previously seen in the Martian meteorite Nakhla that fell in 1911 in Egypt. Composition measurements of the Y000593 spherules show that they are significantly enriched in carbon compared to the nearby surrounding iddingsite layers.
A striking observation is that these two sets of features in Y000593, recovered from Antarctica after about 50,000 years residence time, are similar to features found in Nakhla, an observed fall collected shortly after landing.
The authors note that they cannot exclude the possibility that the carbon-rich regions in both sets of features may be the product of abiotic mechanisms: however, textural and compositional similarities to features in terrestrial samples, which have been interpreted as biogenic, imply the intriguing possibility that the Martian features were formed by biotic activity.
"The unique features displayed within the Martian meteorite Yamato 000593 are evidence of aqueous alterations as seen in the clay minerals and the presence of carbonaceous matter associated with the clay phases which show that Mars has been a very active body in its past," said Gibson. "The planet is revealing the presence of an active water reservoir that may also have a significant carbon component.
Read more at Science Daily
Stethoscopes tend to be more contaminated than the palms of physicians' hands, new research shows.
In a recent Swiss study, researchers discovered that more bacteria cover a stethoscope's diaphragm (the part that's held against a patient's body) than all regions of a physician's hands, except the fingertips.
The study also found a close correlation between the degree of the contamination of the diaphragm and that of the physician's fingertips. There are no official guidelines that tell doctors how often they should clean their stethoscopes, the researchers said.
"The more you have bacteria on the fingertips, the more you find bacteria on the membrane of the stethoscope," said study author Dr. Didier Pittet, director of infection control at the University of Geneva Hospitals.
In the study, 71 patients were examined by one of three physicians who used sterile gloves, and a sterile stethoscope. After the examination, the researchers checked the degree of bacterial contamination on two parts of the stethoscope — the tube and membrane — and four regions of the physician's hands — back, fingertips, the region near the base of the thumb and the region near the little finger.
Researchers found more contamination in the diaphragm than in all regions of the physician's hand, except the fingertips. The tube of the stethoscope also showed more contamination than the back of the physician's hand.
"What was relatively surprising is the degree of colonization, which is pretty high," Pittet said.
The findings may have implications for patient safety regulations.
"It means that the stethoscope needs to be cleaned, some people say 'decontaminated' or 'disinfected,' after each single clinical use," which is not routinely done, Pittet said.
There are currently no recognized guidelines for cleaning stethoscopes anywhere in the world, he said.
However, doctors do use a separate stethoscope for patients infected with bacteria that are resistant to drugs, Pittet said. The new research could lead to additional precautions, he said.
Read more at Discovery News
The 250 kilometer (155 mile) wide 624 Hektor was discovered in 1907 by German astronomer August Kopff, but the existence of its 12 kilometer (7.5 mile) moon wasn’t revealed until 2006 by a team led by SETI Institute astronomer Franck Marchis. Now, eight years of observations of the motion of 624 Hektor’s natural satellite have finally hit paydirt.
Trojans are a special sub-class of asteroid. Trapped in an orbital resonance with Jupiter, they orbit the sun with the same period occupying two regions 60 degrees ahead and 60 degrees behind the gas giant. 624 Hektor is the only Trojan known to possess its own moon.
The technical hurdles are many when trying to observe Trojan asteroids — they are distant and very faint, requiring time on the world’s most powerful observatories, a hurdle that contributed to the long period of time it took to pin down the moon’s orbit.
“The satellite can be seen only with a telescope like Keck Observatory’s fitted with LSG-AO (laser guide-star adaptive optics), but time on the mighty Keck’s is highly prized and in limited availability,” said Marchis in a SETI Institute news release.
The Keck Observatory, located atop Mauna Kea, Hawaii, consists of two telescopes and in this study, Marchis’ team used the Keck II telescope that is outfitted with a precision adaptive optics system that fires a powerful laser high into the atmosphere, creating an artificial star as seen by the telescope’s optics. The motion of the guide star reveals turbulence in the upper atmosphere (the same effect that causes stars to “twinkle”), which can be actively compensated for, revealing deep space objects that would have otherwise been impossible to resolve from ground-based telescopes.
But it was 624 Hektor’s moon’s orbit that also contributed to the complexities of the observation. “(T)he orbit of the satellite is so bizarre that we had to develop a complex new algorithm to be able to pin it down and understand its stability over time,” added Marchis.
With assistance from the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) of the Observatoire de Paris, the moon was found to orbit 624 Hektor every 3 days at a distance of 600 kilometers (372 miles) in an ellipse inclined to 45 degrees from the asteroid’s equator
“The orbit of the moon is elliptical and tilted relative to the spin of Hektor, which is very different from other asteroids with satellites seen in the main-belt,” said SETI Institute scientist and co-author Matija Cuk. “However, we did computer simulations, which include Hektor being a spinning football shape asteroid and orbiting the sun, and we found that the moon’s orbit is stable over billions of years.”
With these observations, the researchers have been able to theorize how 624 Hektor came to form in the strange bi-lobe shape and why it has its own moon. Using Keck II and photometric observations of the asteroid since 1957, the researchers managed to refine the asteroid’s shape and they believe the system was created through the slow collision of two asteroids that fused together. The moon was formed from ejecta from this collision.
“We built several models of equal quality from the photometric data, but we favored a model made of two lobes since some of the best adaptive optics observations suggest that the Trojan asteroid has a dual structure,” said Josef Durech, co-author and researcher at the Charles University in Prague.
Also, it appears Hektor didn’t originate at Jupiter’s orbit; it migrated from the Kuiper Belt, a region of icy rocky bodies around the orbit of Pluto, during the early history of the solar system.
“We also show that Hektor could be made of a mixture of rock and ices, similar to the composition of Kuiper belt objects, Triton and Pluto,” said Julie Castillo-Rogez, researcher at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “How Hektor became a Trojan asteroid, located at only 5 times the Earth–sun distance, is probably related to the large scale reshuffling that occurred when the giant planets were still migrating.”
Read more at Discovery News
This parasitic marvel enslaves cockroaches by stinging their brains in ridiculously precise spots and injecting mind-controlling venom. The wasp then leads its zombified roach to a chamber, where it lays a single egg on its perfectly relaxed host and seals it inside with pebbles. Here the larva bores into the cockroach and feeds off its organs before killing it and emerging from its corpse into the light of day.
This is nature’s own Orkin Man — if the Orkin Man was psychologically imbalanced and just a little too excited about his job, and didn’t have all the wings and stuff. But just think of the evolution involved here. The jewel wasp has over millions of years not only developed a mind-control drug, but an astonishingly methodical brand of brain surgery to deliver it.
Like any good tale, this one begins with sex. We’re not yet sure of their reproductive habits in the wild, but in captivity female jewel wasps mate once in a lifetime. Once she’s fertilized, though, she carries enough eggs to parasitize dozens of cockroaches — one egg per unfortunate bug.
The female jewel wasp will track down a cockroach by smell and sight, hitting it with a lightning-fast strike and biting onto its exoskeleton, then flexing her abdomen to jab at the bug’s vulnerable underbelly. The roach doesn’t take too kindly to this, struggling frantically and tucking in its chin in a desperate attempt to ward off what inevitably follows.
“Stinging a strong prey that’s often six times (or more) larger than yourself is not an easy task,” neurobiologist Ram Gal of Israel’s Ben-Gurion University said in an email interview. “Especially so when the venom must reach the brain of the prey, requiring delicate steering of the stinger inside the head of the cockroach. Hence, upon grabbing the cockroach by the pronotum [the armor], the wasp first injects venom inside the prey’s thorax, namely between the first (‘pro-thoracic’) pair of legs.”
The roach’s front legs are now paralyzed, the first stage of behavioral modification, allowing the wasp to pull its stinger out and jam it into the neck unimpeded. This sting is far more precise, lasting close to a minute compared to a few fleeting seconds of the first. “During this time,” said Gal, “the wasp can uninterruptedly steer its stinger through the different tissues within the cockroach’s head capsule until it finds — using specialized sensory organs on the tip of its stinger — the cockroach’s brain.”
That’s right. The wasp feels its way through the brain, depositing venom in two different spots, the supra-esophageal ganglion and sub-esophageal ganglion. Then she backs off, and at this point the cockroach does something rather unexpected for a bug that’s endured forcible brain surgery: It grooms itself obsessively for half an hour, stuck right at the spot of the attack, as if preparing for a date that sadly never comes. (I’m not trying to make this depressing, it’s just kinda happening.)
While the cockroach is preening, the wasp flies off in search of a burrow, returning as this venom-induced behavior is beginning to fade. And it’s at this time that the third stage of behavioral modification kicks in — full-blown zombification. “It will stay in this state for days, and will not self-initiate locomotion or try to escape,” said Gal.
Plight of the Living Dead
Now the wasp amputates the cockroach’s antennae and drinks its hemolymph, the insect version of blood that’s packed with sugars and proteins, allowing her to replenish energy she lost in the battle. And the cockroach doesn’t resist in the slightest. When she’s done drinking, the wasp then bites down on the stub of a gnawed-off antenna and begins leading the zombified cockroach like a dog on a leash.
But this is no ungainly zombie of popular culture. There’s no stumbling and such. The roach is in absolute control of its faculties, walking perfectly normally and fully cooperating with its master.
Once at the burrow, the wasp unceremoniously shoves the roach inside and lays a single egg on its leg, then begins collecting pebbles. With these she entombs her victim and her voracious offspring. Here, watch my kid for a bit, she seems to say.
“This takes about 30 minutes, during which the cockroach does not try to remove the egg from its leg or to escape its (yet wide open) tomb,” said Gal. “When the wasp finishes sealing the burrow, which is meant to protect the cockroaches (and the egg and developing larva) from potential predators more than prevent it from escaping, it flies off in search of a new prey.”
After about two days, the egg hatches and the larva chews a hole into the cockroach’s abdomen, feeding on the hemolymph that oozes out. It then climbs into the abdomen like Luke kicking it in the tauntaun, though unlike Luke the larva eats the organs, cleverly saving the nervous system for last. Once that’s gone, the cockroach finally dies, at which point the larva secretes an antimicrobial compound on the walls of the now-empty insect. It’ll pupate in this sanitized (it is a corpse, after all) home for a month, then finally break through the husk as an adult wasp.
So what, then, was in that venom that could so thoroughly zombify a cockroach? Gal isn’t yet sure, other than it’s a cocktail of compounds, and that it appears that the same venom is used for the sting to the legs and to the brain. “We therefore assume that different components within this venom cocktail, and their different effects in different parts of the cockroach’s nervous system, are responsible for the different behavioral manipulations (short-term paralysis, grooming, and ‘zombification’).”
Interestingly, if Gal removes the egg from a zombified cockroach’s leg in the lab, it will revert to normal behavior after several days. For Gal, this suggests that the zombification is a more delicate manipulation than a total hijacking of the roach’s nervous system. In addition, remember that the cockroach will walk as it normally does, and will right itself as it typically would if you flip it over, demonstrating that sensory and motor functions are normal.
Yet it chooses to willingly follow the wasp to its doom, so what we have here is actually a conundrum of free will — that highly contentious topic you appropriately enough chose not to pay attention to in Philosophy 101 lectures (Rush did a pretty sicknasty CliffsNotes version, if you’re into the whole brevity thing). The cockroach is fully capable of fleeing, so why doesn’t it? “This implies that, like mammals, insects are not merely ‘automatons’ that react deterministically to external stimuli (a common misconception, among scientists and laymen alike),” said Gal, “but instead have a basic ability to choose when to take action and which action to take.”
“In other words,” Gal added, “and together with evidence from other insect neuroscience research, this may mean that insects have an internal representation of the external environment (similar to mammals’), as well as an ‘internal state’ that drives their motivation to favor specific behavioral actions over others in a given situation. This is what we humans often refer to as ‘free will.’”
So instead of explicitly instructing the cockroach with chemicals, as parasitic fungi do to ants to make their hosts die where the fungi can best grow, the jewel wasp could be using brain surgery to effectively remove the free will of its host. And keep in mind that all this amazing business is, at its core, just really good parenting — a creature going to an extreme to ensure the proliferation of its genes.
Read more at Wired Science
Feb 27, 2014
This strange flickering, known as earthquake lights, can occur before or during quakes. Recent findings suggest earthquake lights seem to happen at rifts where pieces of the Earth are pulling apart from each other.
Normal lightning results from the buildup of electrical charge in clouds. However, lab experiments now suggest earthquake lights may instead originate from the buildup of electrical charge in the ground surrounding geological faults.
Applied physicist Troy Shinbrot, of Rutgers University in New Jersey, and his colleagues looked at three different kinds of particles — plastic disks, glass particles and organic powders, such as flour — that stick and slip in much the same way the Earth does in earthquake zones.
He and his colleagues study electric charge in powders, which, for example, can make pharmaceutical mixtures separate or stick to surfaces in unwanted ways in factories.
The researchers discovered these different systems all developed an electrical voltage when physically disturbed, though there is currently no known physical mechanism for exactly how they do this.
"If you take a Tupperware container filled with flour and tip the container, when the flour shifts, voltages of around 100 volts inexplicably appear," Shinbrot told Live Science's Our Amazing Planet. "Except for the fact that we cannot get these voltages to go away, I would call this 'crackpot physics,' and even as it is, I wish I could hedge my bets, but the voltages are very repeatable, and we have so far failed to account for a spurious influence that might cause them."
The effects are "so improbable that they could be wrong," Shinbrot said. "This is why we tested the effect in as different situations as possible." This included using a variety of particles, a variety of container materials and sizes, and a variety of humidity levels.
"Always we expect the effect will go away, and always it persists," Shinbrot said.
Unexplained electrical effects
The scientists previously sought to explain other mysteries regarding electrical charge. For example, it remains unclear how lightning can happen in sandstorms, even though sand is an electrical insulator, making lightning in sandstorms akin to seeing thunderbolts emerge from a storm full of rubber balls.
The researchers suggested there may be some unknown material property that produces voltages whenever cracks appear in powders or grains.
"There are analogous — and also largely unexplained — effects seen in other materials," Shinbrot said. "These go by the name of 'fractoluminescence,' and appear as flashes of light when wintergreen Life Savers are broken in a darkened room, when transparent tape is peeled from a roll or when mercury slips on glass."
Read more at Discovery News
An ancient Roman gladiator school has been discovered in Austria, complete with cell blocks, a training arena and a bath complex, archaeologists say.
The buried remains of the school — at the site of Carnuntum, near Vienna — were detected not through excavations but through remote-sensing techniques. Based on these findings, researchers reconstructed the gladiator center in virtual 3D models.
Archaeologists have been studying Carnuntum, which is on the south bank of the River Danube, for more than 100 years. Previous excavations at the ancient military city had revealed parts of the civilian town, the legionary fortress and an amphitheater.
The newly discovered gladiator school, or ludus, covers 30,138 square feet (2,800 square meters), and the building complex is arranged around a central courtyard. The school was built during the second century A.D., Wolfgang Neubauer of the University of Vienna told Live Science.
"The most prominent feature inside the courtyard is a free-standing circular structure 19 m [62 feet] in diameter, which could be interpreted as the training arena for the gladiators," the authors write in the journal Antiquity.
The researchers, led by archaeologist Neubauer, say this arena would have been surrounded by wooden spectator stands set on stone foundations, which were clearly visible in the ground-penetrating radar data. These measurements also revealed something like a post-hole in the middle of the arena.
"This might be the foundation of the palus, a wooden pole used for exercising blows with the sword and body slams with the shield," Neubauer and colleagues wrote.
In the southern wing of the building complex, the researchers detected cell blocks that each covered only 32 to 75 square feet (3 to 7 square meters). Cells of a similar design have been found at the barracks at the ludus magnus, the gladiatorial school close to the Flavian amphitheater in Rome, the archaeologists wrote.
Other rooms along the western wing at Carnuntum were more spacious and were perhaps even decorated with tile floors. The researchers wrote that these chambers "were most likely reserved for the highest ranking gladiators or the instructors, many of whom probably were drawn from the ranks of senior and ex-gladiators."
The site also contains evidence of the living quarters of the school's owner, or the lanista, and a bath complex, where the gladiators could recover from their harsh training, the report says.
The archaeologists found the outline for the gladiator school over the last few years using non-invasive techniques like aerial photography, ground-penetrating radar and magnetometer surveys. The team also analyzed the area using an electromagnetic induction (EMI) sensor attached to a four-wheeler ATV. This method allows researchers to transmit an electromagnetic field to create currents in the soil. By determining the soil's electrical conductivity and its magnetic susceptibility, scientists can find out if the earth underneath has ever been heated, revealing the location of hidden bricks (which are made by heating clay).
Read more at Discovery News
Dating back as early as 1615 B.C., the lumps of yellowish organic material have provided direct evidence for the oldest known dairy fermentation method. The individuals were likely buried with the cheese so they could savor it in the afterlife.
Although cheese-making is known from sites in northern Europe as early as the 6th millennium B.C. and was common in Egypt and Mesopotamia in 3rd millennium B.C., until now no remains of ancient cheeses had been found.
The 3,600-year-old cheese was discovered during archaeological excavations carried between 2002 and 2004 at the Xiaohe cemetery, in the inhospitable Taklamakan desert in northwestern China, lead by Idelisi Abuduresule from Cultural Relics and Archaeology Institute, Ürümchi.
Also known as Small River Cemetery Number 5, the burial was first discovered in 1934 by Sweden archaeologist Folke Bergman and it's part of several archaeological sites spread in the Tarim Basin.
The cemetery was built on a large natural dune and houses hundreds of mysterious mummies with Caucasian features, buried into massive wooden coffins resembling upside-down boats.
"Recent DNA studies showed the population of these sites was mixed, European and Asian," Anna Shevchenko, proteomics specialist in Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany, told Discovery News.
Taklamakan literally means "go in and you won't come out." The area, with its salty, hyper-dry sands, extreme hot in summer and cold in winter, provided the perfect conditions for natural mummification.
Moreover, the boat-like coffins were covered by several layers of cowhide, which sealed them from air, water and sand as if they had been "vacuum-packed."
Skin and hair, baked onto the dehydrated corpses, remained almost intact, as well as woolen textiles, plant seeds, woven grass baskets and clumps of organic material around the neck and chest of the mummified bodies. No pottery was found that could be associated with making or consuming food.
The researchers lead by Chinese team leader Changsui Wang from the University of Chinese Academy of Sciences collected 13 samples of the yellowish organic material from 10 tombs and mummies, which included the so-called "Beauty of Xiaohe" -- a 3,800-year-old female mummy wrapped in a finely crafted shroud, bearing Caucasian features such as a long nose and light hair.
Protein analysis performed in Dresden showed the organic material wasn't butter or milk, but a cheese made by robust, easily scalable kefir fermentation. Shevchenko explained that such analysis is common in medical and biological science, but not in archaeology.
"Usually, proteins are either ignored or protein bulk content is estimated to characterize the nutritional properties," Shevchenko said.
"According to common belief, they are difficult to recover from the sample matrix, totally degraded and samples heavily contaminated by environment, therefore the analyzed are hardly meaningful," she added.
But according to the researchers, who have detailed their finding in an upcoming issue of the Journal of Archaeological Science, proteins do survive under extreme conditions. Furthermore, in contrast to commonly analyzed lipids, they may bear the hallmarks of technological processes used to prepare the food. Altogether, they can be highly informative molecules.
"Our work opens new perspectives in the analysis of ancient material. But most importantly, it shows the technology behind ancient cheese-making," Germany team leader Andrej Shevchenko, an analytical chemist at Germany's Max Planck Institute of Molecular Cell Biology and Genetics, told Discovery News.
Indeed, the analysis revealed Xiaohe's cheese wasn't made with rennet, an chymosine containing enzyme complex from calf intestine which was widely used since ancient times for curdling ruminant milk.
It was instead produced by combining milk with a mix of Lactobacillus kefiranofaciens and other lactic acid bacteria and yeasts.
The technique is still used today to make kefir cheese, similar to cottage cheese, and a kefir probiotic lactose-free beverage, food with a slightly sour taste first mentioned by Marco Polo in 13th century.
"It's the earliest known dairy practice that persists until present times in an almost unchanged way. The discovery moves the mysterious history of kefir as far as to the second millennium B.C., making it the oldest known dairy fermentation method," archaeologist Yimin Yang at the University of Chinese Academy of Sciences, Beijing, told Discovery News.
Edible for the lactose-intolerant inhabitants of Asia, the mummies' cheese was very simple to make. Kefir fermentation did not require slaughtering the livestock to obtain the curdling enzyme.
Furthermore, milk fat might have been physically removed in kefir cheese production, as now is commonly practiced in rural areas across the Eurasia steppe and also in Tibet.
"It's the first direct evidence that milking spread to Eastern Eurasia," Wang said.
Read more at Discovery News
In the new Perspectives article, published today (Feb. 27) in the journal Science, the researchers compile existing data to support the idea, known as the Beringia standstill hypothesis.
Among that evidence is genetic data showing that founding populations of Native Americans diverged from their Asian ancestors more than 25,000 years ago. In addition, land in the region of the Bering Strait teemed with grasses to support big game (for food) and woody shrubs to burn in the cold climate, supporting a hard-scrabble existence for ancient people.
Given the hypothesis, archaeologists should look in regions of Alaska and the Russian Far East for traces of these ancient people's settlements, the authors argue.
A dominant theory suggests the ancestors of Native Americans crossed the Bering Strait about 15,000 years ago and quickly colonized North America, and then South America.
But in 2007, genetics researchers found that almost all Native Americans in North and South America shared genetic mutations in their mitochondrial DNA, which is the genetic information that's carried in the cytoplasm of the egg and passed on through the maternal line. None of the mutations show up in Asian populations from which the Native American ancestors diverged, said study co-author John Hoffecker, an archaeologist and paleoecologist at the University of Colorado, Boulder. (Genetic evidence also suggests that some northern populations, such as the Inuit, likely came over in a second wave separate from the ancestors of Native Americans.)
Given the rate at which such mutations occur, the findings suggested a single Native American founding population must have been isolated from its Asian ancestors for thousands of years before dispersing throughout the Americas.
Other evidence fits the genetic data. Between 28,000 and 18,000 years ago, glaciers covered much of the Americas and northern Asia, blocking human migration into North America.
But in the 1930s, Swedish botanist Eric Hultén proposed that the region known as Beringia, which includes the land bridge now submerged under the Bering Strait, was a refuge for shrubby tundra plants. Pollen, insects and other plant remains taken from sediments beneath the Bering Sea confirmed this picture.
The outer portions of Beringia, in what is now Alaska and the Russian Far East, were likely drier grassland steppes where woolly mammoths, saber-toothed tigers and other big game grazed, Hoffecker said.
This region would have had two crucial resources that other Arctic areas didn't: woody plants to start fires and animals to hunt, Hoffecker said.
"The central part of Beringia was probably the mildest, most comfortable place to live at high latitudes during the last glacial maximum," Hoffecker told Live Science. "It's the most logical place for a group of people to hunker down."
Once the glaciers melted, only then did the Beringian inhabitants stream into North America, traveling along the coastline and into the interior through ice-free passageways, Hoffecker said.
No archaeological sites
While it's possible that the ancestors of Native Americans were isolated in Beringia for 10,000 years, the standstill hypothesis is hobbled by one detail: a lack of archaeological evidence prior to 15,000 years ago, said David Meltzer, an anthropologist at Southern Methodist University in Dallas, who was not an author on the new paper.
Some of the archaeological sites would have been washed away as the Bering Strait flooded, but "at least half of Beringia is still above water, so where are the sites?" Meltzer told Live Science. "If people were there for 10,000 years, you'd surely see evidence for them by now."
Read more at Discovery News
Astronomers have long wondered why giant elliptical galaxies stop forming stars, becoming dominated over time with small, long-lived stars with a distinctive reddish tinge. Conventional wisdom had held that these galaxies lack the cold gas necessary for star birth.
But new observations suggest that a rethink is in order. Some big ellipticals do indeed harbor large amounts of cold gas — but these reservoirs likely get heated up or driven off by powerful jets of material blasted out by supermassive black holes, which lurk at the heart of most if not all galaxies.
"These galaxies are red, but with the giant black holes pumping in their hearts, they are definitely not dead," study lead author Norbert Werner, of Stanford University, said in a statement.
Werner and his colleagues studied eight giant elliptical galaxies using the European Space Agency's Herschel Space Observatory. They found that six of the eight have lots of cold gas, which Herschel detected as far-infrared emissions from carbon ions and oxygen atoms.
The team then investigated the galaxies' stockpiles of hotter gas, looking at optical images as well as X-ray data gathered by NASA's Chandra X-ray Observatory.
They determined that, in the six galaxies with large quantities of cold gas, the hotter stuff is cooling down, as predicted by theory — but the cooling process has stopped for some reason. In the two galaxies without cold gas, the hot material seems not to be cooling down at all, researchers said.
"The contrasting behavior of these galaxies may have a common explanation: the central supermassive black hole," said co-author Raymond Oonk of ASTRON, the Netherlands Institute for Radio Astronomy.
The two ellipticals without cold gas have incredibly active central black holes at their cores, which are accreting material at a breakneck pace and launching energetic jets out into space, researchers said. These jets could be reheating the cold gas or clearing it away from the galaxies altogether.
Read more at Discovery News
Feb 26, 2014
Dozens of fossilized whales, seals and other marine animals have been discovered piled up in an ancient tidal flat in northern Chile, providing the first fossil evidence of repeated mass die-offs, according to a new report.
Four distinct layers of bones appear at the site, suggesting the mass die-offs — also known as mass strandings — occurred repeatedly over the course of thousands of years, some time between about 6 million and 9 million years ago, an international team of scientists report. Whale bones dominate the site, but the researchers have also identified 10 other types of marine animals in each layer, including aquatic sloths and a brand-new seal species.
Many of the skeletons overlap each other and appear to be belly-up, which the paleontologists interpret to suggest the animals died offshore and were subsequently washed into the shallow waters of a tidal flat where sand eventually buried them.
The scientists think the animals were most likely poisoned-to-death from so-called harmful algal blooms, similar to the blooms that cause red tides today. Certain species of plankton produce small quantities of toxins that can become lethal to marine life when consumed or inhaled in large quantities. The toxins can accumulate in the environment when plankton blooms in thick mats, often as a result of rapid fertilization from an inflow of nutrients spilling off from nearby land, or upwelling from deep ocean water.
Other possible causes for mass die-offs — aside from the human causes that weren't relevant 9 million years ago, such as pollution and injury from navy sonar — include tsunamis and viruses. However, no evidence for a tsunami was found, and viruses do not generally affect such a wide array of species, study co-author Nicholas Pyenson, a researcher at the Smithsonian Institution, told Live Science.
To further support their case for harmful algal blooms as the cause of the deaths, the team found orange splotches in the rock surrounding many of the skeletons that they believe could have been left by the chemical degradation of the algal mats over time. The researchers analyzed the orange rock under a high-power microscope, and found tiny spheres similar to those found in dinoflagellates — the plankton responsible for producing red tides today.
Still, the spheres have degraded over time, so the researchers cannot definitively confirm they come from a species associated with harmful algal blooms.
"It's a good candidate, but we can't exclude the possibility that these have a geological origin," Pyenson told Live Science.
Harmful algal blooms have been responsible for mass marine die-offs in modern times as well, including an incident off the coast of Cape Cod in the late 1980s that resulted in 14 humpback whales piling up near shore in a similar way these fossils appear to have piled up in Chile.
The findings confirm that marine animals have experienced mass die-offs before humans began interfering with the environment, and also provide a rich window into ancient marine ecology, Pyenson said.
Read more at Discovery News
Sultan Moulay Ismaïl of Morocco, "The Bloodthirsty," reputedly sired hundreds of children and perhaps more than a 1,000. Now computer simulations suggest this could have been possible if the ruler had sex about once a day for 32 years.
Ismaïl, who reigned from 1672 to 1727, was the first great sultan of the Moroccan Alaouite dynasty, the current royal house of the kingdom. He was Sharifian — that is, he claimed descent from Muhammad, the founder of Islam.
Ismaïl's rule was the longest in Moroccan history, and toward its end he controlled the country with an army of more than 150,000 men. Ismaïl was infamously ruthless — his reign is said to have begun with the display of 400 heads at the city of Fez, most of them from enemy chiefs, and over the next 55 years it is estimated he killed more than 30,000 people, not including those in battle.
Any suspicion of adultery against Ismaïl was severely punished. The women were either strangled by the sultan himself, or their breasts were cut off, or their teeth torn out. Men who merely looked at one of his wives or concubines were punished by death.
According to the Guinness Book of World Records, Ismaïl fathered 888 children, the greatest number of progeny for anyone throughout history that can be verified. Based on reports by Dominique Busnot, a French diplomat who frequently traveled to Morocco, the sultan may actually have had 1,171 children from four wives and 500 concubines by 1704. At that time, Ismaïl was 57 and had ruled for 32 years.
Some researchers claimed it was unlikely Ismaïl could have fathered that many offspring, noting that women are only fertile for a small window each month, that sperm usually do not fertilize eggs, and that infertility often afflicts women, especially in the developing world. However, other scientists argued women are more fertile than those doubting Ismaïl had said.
To solve this question, scientists developed computer simulations to see how many times Ismaïl had to have sex each day to have 1,171 children in 32 years. They found the sultan could have set this record.
"We were as conservative as possible with our calculations, and Moulay could still achieve this outcome," study lead author Elisabeth Oberzaucher, an anthropologist at the University of Vienna, told Live Science.
The simulations were based on a variety of models of conception. For instance, one set of simulations assumed the menstrual cycles of women do not synchronize, while another suggested they could. Other factors included how good Ismail's sperm were at fertilizing women's eggs as he aged and how women often may look more sexually attractive when they are most fertile during their menstrual cycles.
The simulations suggest Ismaïl needed to have sex an average of 0.83 to 1.43 times per day in order to father 1,171 children in 32 years. Moreover, the sultan did not need a harem of four wives and 500 concubines to sire that many offspring — the researchers suggest he needed a harem of only 65 to 110 women.
Read more at Discovery News
The study, published in the latest Proceedings of the Royal Society B, helps explain both the historical origins and biological significance of skin coloration in humans.
Author Mel Greaves, a professor at The Institute of Cancer Research in the U.K., told Discovery News that "the likelihood is that the common ancestor of hominins and chimps had pale skin."
Greaves explained that chimpanzees and many other primates, under their fur, have pale skin with pigment-producing cells restricted to hair follicles. Sometime between 2 and 3 million years ago, our ancestors in East Africa experienced a dramatic loss of body hair. Primates that are not directly on the human family tree kept their copious amounts of hair/fur, while our ancestors lost much of it.
As for why the hair loss occurred, Greaves said that it was "almost certainly to facilitate heat loss by sweating in physically very active hunters, especially in the more open, dry and hot Savannah."
Indigenous humans from East Africa and throughout sub-Saharan Africa today all have black skin, however, and DNA reveals that these individuals evolved a gene, MC1R, associated with skin pigment production. Many scientists over the years, including Charles Darwin, theorized that black skin was acquired early in human evolution as an adaptation to limit UV radiation damage from sun exposure.
To test that theory, Greaves studied African albinos, meaning people who have a congenital absence of pigment in their skin, hair and eyes. He found that they were highly susceptible to developing skin cancer.
"Almost all albinos in equatorial Africa develop skin cancer in their 20's," Greaves told Discovery News. "A few -- maybe 10 percent -- escape, and these are mainly females with a more indoor lifestyle."
Data on albino individuals from other warm climates, such as in Central America, reveal that they are also prone to developing skin cancer. While dark skin doesn't always prevent skin cancer, high concentrations of melanin -- the pigment that gives skin color -- can serve as a natural defense against UV rays.
The melanin-associated gene probably arose by accident in human ancestors, Greaves explained, with natural selection favoring it by increased survival of those who had it, and who would have then passed it on to their children.
Non-albino people with light skin today therefore probably had ancestors that began as pale skinned, evolved darker skin, and then evolved light skin again.
"We assume that all hominin migrants from Africa over the past 100,000 years would have been dark skinned," Greaves said. "What happened to those migrant populations' skin color later depended upon geography and UVR (ultraviolet radiation) exposures. Those migrating into Europe underwent selection in favor of paler skin -- probably to gain more Vitamin D (essential for healthy bones and teeth)."
He continued, "Those migrants who tracked the tropics or equator into southern India, New Guinea and Australasia maintained their original dark skin," since they were under conditions of higher UV radiation.
Read more at Discovery News
The number of known planets beyond the solar system took a giant leap thanks to a new technique that verifies candidate planets found by NASA’s Kepler space telescope in batches rather than one-by-one.
The new method adds 715 planets to Kepler’s list of confirmed planets, which previously totaled 246, scientists said Wednesday.
Combined with other telescopes’ finds, the overall exoplanet headcount now reaches nearly 1,700.
"By moving ... to statistical studies in a 'big data' fashion, Kepler has showcased the diversity and types of planets present in our galaxy," astronomer Sara Seager, with the Massachusetts Institute of Technology, wrote in an email to Discovery News.
The growing census reinforces previous findings that small planets are most common in the galaxy -- a boon for future missions aimed at finding planets in habitable zones around parent stars, Seager said.
It also shows that most planets, like those in our solar system, are part of multiple-planet systems. The 715 newly confirmed planets, for example, comprise 305 planetary systems.
The similarity to our own solar system ends there, however.
The study confirms:
- A binary star system with a total of three planets, two of which transit one star and one of which transits the second.
- A star with seven planets all orbiting their parent star closer than Earth circles the sun.
- A star with five confirmed planets, four of which orbit in less than 14 days and the fifth with an 87-day period. That system, newly named Kepler-169, also may have a sixth planet in a 30-day orbital period.
The planets circling Kepler-169 have plenty of elbowroom compared to Kepler-80, which has five candidate planets all circling their parent star in less than 10 days.
"We validate the four outer candidates (of Kepler-80) ... to be planets," astronomer Jack Lissauer, with NASA’s Ames Research Center in Moffett Field, Calif, wrote in paper to be published in The Astrophysical Journal.
"The inner candidate has too short an orbital period for us to validate, but passes all of our other validation criteria," he wrote.
In a related paper in the same journal, astronomer Jason Rowe, also with NASA Ames, said the algorithm used to validate the 305 planetary systems has an accuracy rate of better than 99 percent.
“The vast majority of (the systems’ 715 planets) have not been previously identified as planets,” Rowe wrote.
Read more at Discovery News
SN 2014J is known as a Type 1a supernova, a very special kind of supernova. It is thought a Type 1a supernova is triggered by a white dwarf — an ancient small star that is the stellar husk of a star of approximately the same mass as our sun — accumulating material from a binary partner star. When the accumulated mass reaches a certain threshold, the bloated white dwarf ignites a supernova. As the threshold of material is very specific, which generates a very specific quantity of energy, Type 1a supernovae are used by astronomers as “standard candles” to measure the scale of the Universe. If you know the amount of energy released by this supernova, no matter where it is in the Cosmos, you can precisely measure your distance from it.
Read more at Discovery News
Feb 25, 2014
The researchers refer to the crystals as 'living' because they, in a sense, take on a life of their own from very simple rules.
Sharon Glotzer, the Stuart W. Churchill Collegiate Professor of Chemical Engineering, and her team found that when they spun individual nanoparticles in a simulation -- some clockwise and some counterclockwise -- the particles self-assembled into an intricate architecture.
The team discovered the behavior while investigating methods to make particles self-assemble -- one of the major challenges in nanotechnology -- without complicated procedures. When the pieces are a thousand times smaller than a grain of sand, normal techniques for building structures are no longer effective.
For this reason, researchers like Glotzer are exploring ways to make order develop naturally from disorder, much like what may have occurred at the very beginnings of life.
"If we can understand that, not only can we begin to imagine new ways to make materials and devices, but also we may begin to understand how the first living structures emerged from a soup of chemicals," said Glotzer, who is also a professor of materials science and engineering, macromolecular science and engineering, physics, and applied physics.
"One way biology approaches the challenge of assembly is by constantly feeding building blocks with energy. So, that's what we did with nanoparticles."
Recently, researchers in the field have found that if particles are given energy for some basic motion, such as moving in one direction, they can begin to influence one another, forming groups. Glotzer's team looked at what would happen if the particles all were made to rotate.
"They organize themselves," said Daphne Klotsa, a research fellow in Glotzer's lab. "They developed collective dynamics that we couldn't have foreseen."
The team's computer simulation can be imagined as two sets of pinwheels on an air hockey table. The air pushing up from the table drives some of the pinwheels clockwise, and others counterclockwise. When the pinwheels are tightly packed enough that their blades catch on one another, the team found that they begin to divide themselves into clockwise and counter-clockwise spinners -- a self-organizing behavior known among researchers as phase separation.
"The important finding here is that we get phase separation without real attraction," Klotsa said.
She calls the self-sorting counterintuitive because no direct forces push the same -- spin pinwheels together or push opposite-spinners apart.
The separation occurs because of the way the pinwheel blades collide. While a pair of pinwheels may be spinning in the same direction, where their blades might meet, they're actually moving in opposite directions. This means that the blades will push into one another and stick together, causing the pair of pinwheels to rotate as one, at least briefly.
In contrast, the blades of opposite spinners are moving in the same direction where they meet, so they don't stick together. Since same-spinning pinwheels spend more time linked up, they gradually accumulate into groups.
Read more at Science Daily
Water has been detected in the atmosphere of a planet outside our solar system with a new technique that could help researchers to learn how many planets with water, like Earth, exist throughout the universe. The team of scientists that made the discovery includes astronomers at Penn State University and other institutions. The astronomers detected the water in the atmosphere of a planet as massive as Jupiter that is orbiting the nearby star tau Boötis.
The discovery is described in a scientific paper published in the 24 February 2014 online version of The Astrophysical Journal Letters.
Chad Bender, a research associate in the Penn State Department of Astronomy and Astrophysics and a co-author of the paper, said "Planets like tau Boötes b, which are as massive as Jupiter but much hotter, do not exist in our solar system. Our detection of water in the atmosphere of tau Boötes b is important because it helps us understand how these exotic hot-Jupiter planets form and evolve. It also demonstrates the effectiveness of our new technique, which detects the infrared radiation in the atmospheres of these planets."
Scientists previously had detected water vapor on a handful of other planets, using a technique that works only if a planet has an orbit that passes it in front of its star, when viewed from Earth. Scientists also were able to use another imaging technique that works only if the planet is sufficiently far away from its host star. However, significant portions of the population of extrasolar planets do not fit either of these criteria, and there had not been a way to discover information about the atmospheres of these planets.
"We now are applying our effective new infrared technique to several other non-transiting planets orbiting stars near the Sun," Bender said. "These planets are much closer to us than the nearest transiting planets, but largely have been ignored by astronomers because directly measuring their atmospheres with previously existing techniques was difficult or impossible." With the new detection technique and more-powerful future telescopes such as the James Webb Space Telescope and the Thirty Meter Telescope, the astronomers expect to be able to examine the atmospheres of planets that are much cooler and more distant from their host stars, where liquid water is even more likely to exist.
Read more at Science Daily
A "microbial Pompeii" has been found on the teeth of 1,000-year-old human skeletons. Just as volcanic ash entombed the citizens of the ancient Roman city, dental plaque preserved bacteria and food particles on the skeletons' teeth.
Researchers analyzed dental plaque from skeletons in a medieval cemetery in Germany, and found that the mouths of these aged humans were home to many of the same bacterial invaders that cause gum disease in the mouths of modern humans.
"One thing that is clear about the population we studied is that they didn't brush their teeth very often, if at all," said study leader Christina Warinner, an anthropologist at the University of Zurich in Switzerland and the University of Oklahoma in Norman.
The discovery of these bacteria also revealed clues to the dental hygiene and diets of these centuries-old humans, according to the study detailed today (Feb. 24) in the journal Nature Genetics.
Plaque is a dentist's worst enemy, but it turns out to be a great time capsule for preserving the bacteria (or "microbiome") and bits of food on the teeth of humans long after they die. The sticky bacteria on teeth trapped particles of food and other debris, and over time, the calcium phosphate in saliva — the same mineral found in bones and teeth — caused the plaque to calcify into tartar.
"We knew that calculus preserved microscopic particles of food and other debris but the level of preservation of biomolecules is remarkable — a microbiome entombed and preserved in a mineral matrix, a microbial Pompeii," another study researcher, Matthew Collins from the University of York, in England, said in a statement.
With their new study, Warinner and her colleagues are the first to sequence the DNA in ancient dental tartar, using a rapid method known as "shotgun sequencing." The team reconstructed the genome of a major bacterial pathogen and recovered some of the first evidence of food molecules from ancient dental plaque.
The DNA in food found in the plaque matched pigs, sheep, bread wheat and vegetables such as cabbage. The researchers also found starch granules that matched cereals and the pea/bean family.
"Amazingly, it's much the same thing you would find at a German restaurant today," Warinner said.
The skeletons had many years' or decades' worth of plaque built up on their teeth, and many of them showed signs of gum disease and tooth decay. While a few individuals had surprisingly healthy teeth, most of the older adults had lost most or all of their teeth due to wearing, decay or dental disease.
The microbe species found in the ancient plaque were remarkably similar to ones found in modern mouths, the researchers said. Gum disease is most often caused by the species Porphyromonas gingivalis, Tannerella forsythia,Treponema denticola and Filifactor alocis, and these microbes were all present on the teeth of the skeletons with dental disease.
Read more at Discovery News
The majority of camels in Saudi Arabia have been infected with Middle East Respiratory Syndrome (MERS) virus, and the virus has been circulating among the animals there for at least 20 years, a new study suggests.
Researchers tested blood, nasal and rectal samples from dromedary (one hump) camels throughout Saudi Arabia, as well as archived blood samples from camels in the region that were collected as far back as 1992. MERS first appeared in people in September 2012, and since then, 182 people have been infected, most in Saudi Arabia. Seventy-nine people have died from the infection.
The first person known to have MERS was a Saudi Arabian man who owned four pet camels.
The new research found that 74 percent of camels had antibodies against the MERS virus, indicating that they had been infected with MERS virus or a very similar virus in the past. Antibodies were more common in adult camels than young camels: 95 percent of camels older than age 2 had antibodies against the virus, compared to 55 percent of camels younger than 2.
In contrast, younger camels were more likely to have active virus (35 percent of young camels had active virus in their nasal samples, compared to 15 percent of adult camels).
These finding suggest that, for camels, MERS infection "typically occurs in early life, and that if people get the virus from camels, the most likely source is young camels," study researcher Dr. W. Ian Lipkin of Columbia University, New York, said in a statement.
The archived blood samples also contained MERS antibodies, suggesting the MERS or a similar virus has been circulating in camels for at least two decades.
Previously, the researchers found that camels had antibodies against the MERS virus, and that some were infected with active virus. The new study is the first to perform a countrywide survey of camels in Saudi Arabia.
However, the new study does not prove that humans caught the virus from camels, and more studies are needed to rule out other possibilities. For example, it could be that another animal infects both humans and camels. The MERS virus has also been found in bats.
Read more at Discovery News
Feb 24, 2014
A planet-hunting project is snapping pictures of alien worlds and other objects orbiting nearby stars in an effort to give scientists a better understanding of these intriguing exoplanets.
Project 1640 is designed to probe the atmospheres of exoplanets to create new, low-resolution images of the planets and their stars. By understanding the atmosphere of the planets and the composition of the stars, scientists working with the project could potentially learn more about how they formed.
Scientists working with Project 1640 — an imaging system at the Palomar Observatory in California — are using the specialized system to survey about 200 stars looking for a range of planets and other objects, project scientist Ben Oppenheimer said at the American Museum of Natural History event on Feb. 5. According to AMNH officials, Project 1640 is "the most advanced and highest contrast imaging system in the world."
"The planets of our own solar system, of course, are planets in and of themselves and in order to understand them — and indeed this planet — I think we need to study other planets," Oppenheimer said. "If you just look at the planets of our own solar system, they're really complicated."
The project is designed to help space scientists get a better sense of the diversity of planets that exist in the universe. Scientists are also looking for mysterious cosmic objects known as brown dwarfs that are too large to be considered a planet, but too small to produce fusion in their cores.
Different chemicals, like carbon dioxide, absorb light differently, allowing scientists working with Project 1640 to take measurements and see where various signatures fall on the spectra.
Oppenheimer and his colleagues using Project 1640 have already peered into the atmospheres of four cloud-covered alien planets around the star HR 8799, 127 light-years from Earth. All four of the planets are more massive than Jupiter and display some odd characteristics.
"These warm, red planets are unlike any other known object in our universe," Oppenheimer said in a statement announcing the discovery in 2013. "All four planets have different spectra, and all four are peculiar. The theorists have a lot of work to do now."
Read more at Discovery News
The feminine hygiene device seems to have been tossed out with the refuse of a pretty good party around the time City Hall was being built 200 years ago. Archaeologists say the syringe was unearthed among alcohol bottles, smoking pipes, fine pottery and the bones of sheep, cows, fish and even turtles — then a delicacy — that were likely served for dinner.
"We think the trash deposit feature was from a single event, possibly a celebratory event," said Alyssa Loorya, who heads the Brooklyn-based Chrysalis Archaeological Consultants. She explained the pile didn't have the characteristic layers that would build up over time in a continuously used dump.
The garbage pile was uncovered during excavations in 2010 as part of a project to rehabilitate City Hall, Loorya told Live Science. But the syringe wasn't identified until Chrysalis archaeologist Lisa Geiger, who is a graduate student at Hunter College, made the connection while she was volunteering as a guide at Philadelphia's Mutter Museum.
The museum houses all sorts of medical oddities, and while looking through the back collections, Geiger said she came across vaginal syringes that were the same size and shape as the object found at City Hall.
The device would have been used to irrigate the vagina with different solutions and tonics to treat venereal disease, prevent pregnancy and maintain good hygiene. (Douching is generally discouraged today as research has shown the practice can disturb the natural bacterial ecosystem of the vagina.)
These syringes weren't uncommon, but discussing feminine hygiene openly at the time was taboo. To research 19th-century douching, Geiger turned to historical ads and instructional booklets, which were becoming more prevalent as consumer trade grew and women took charge of family health care.
"There are these advertisements that kind of use creative language to dance around the use of these things," Geiger told Live Science. "It's not written about so overtly in the record, so the physical object in this case gave us an avenue to look at how women conceived of themselves and how they conceived of their hygiene."
Read more at Discovery News
Western Europe may have undergone a population crisis during a cold stretch of the Neanderthal era, a new study of mitochondrial DNA sequences suggests.
"The fact that Neanderthals in Western Europe were nearly extinct, but then recovered long before they came into contact with modern humans came as a complete surprise to us," study co-author Love Dalén, associate professor at the Swedish Museum of Natural History in Stockholm, told Phys.org.
"This indicates that the Neanderthals may have been more sensitive to the dramatic climate changes that took place in the last Ice Age than was previously thought."
By analyzing the amount of genetic variation in the DNA from 13 Neanderthals, the scientists pieced together the puzzle of a demographic history. The DNA of Neanderthals from more than 50,000 years ago showed a high degree of genetic variation, in contrast to the DNA of those from less than 50,000 years ago. That group showed much less genetic variation.
Until now, the Neanderthal population was assumed to be stable until modern humans began showing up. Extinction was avoided when Neanderthals from surrounding areas repopulated the region. But the new research suggests that Neanderthals may have been more susceptible to cold than previously thought.
"At the very least, this tells us that without the aid of material culture or technology, there is a limit to our biological adaptation," co-author Rolf Quam of the University of Binghamton said.
Read more at Discovery News
A rare, polio-like syndrome that has no known cure has emerged in a small number of children in California, U.S. researchers said.
Five cases of sudden onset paralysis were described by Stanford University experts at the American Academy of Neurology annual meeting in Philadelphia.
"Although poliovirus has been eradicated from most of the globe, other viruses can also injure the spine, leading to a polio-like syndrome," said Stanford neurologist and lead author of the case reports, Keith Van Haren.
"In the past decade, newly identified strains of enterovirus have been linked to polio-like outbreaks among children in Asia and Australia," he said in a statement.
"These five new cases highlight the possibility of an emerging infectious polio-like syndrome in California."
Polio has been largely wiped out across the globe, thanks to the introduction of an effective vaccine in the mid 1950s.
However, outbreaks of the highly contagious disease continue in parts of the world, including Pakistan, Nigeria and Afghanistan.
The California children tested negative for polio, and all had been vaccinated.
The patients showed similar symptoms, such as sudden loss of movement in one or more of their limbs, resulting in paralysis usually within two days.
Three of the five youths had respiratory illness before their symptoms began.
Two have tested positive for enterovirus-68, a rare virus that has been previously associated with polio-like symptoms.
Read more at Discovery News
Feb 23, 2014
The park, which encompasses lowland Amazonian rain forest, high-altitude cloud forest and Andean grassland east of Cuzco, is well known for its huge variety of bird life, which attracts ecotourists from around the globe. More than 1,000 species of birds, about 10 percent of the world's bird species; more than 1,200 species of butterflies; and now 287 reptiles and amphibians have been recorded in the park.
"For reptiles and amphibians, Manu and its buffer zone now stands out as the most diverse protected area anywhere," said study coauthor Rudolf von May, a post-doctoral researcher in UC Berkeley's Museum of Vertebrate Zoology.
Despite the park's abundant and diverse animal life, von May said, not all is well in the preserve. The devastating chytrid fungus has caused a decline in the number of frogs there, as it has elsewhere around the world, while deforestation for subsistence living, gold mining and oil and gas drilling are encroaching on the buffer zone around the park.
"All of this is threatening the biodiversity in the park and the native peoples who live in settlements in the park," von May said. At least four Amazonian tribes and a nomadic group of hunter-gatherers known as Mashco-Piro live within the confines of Manu National Park and its buffer zone.
Von May, a native of Peru, and coauthor Alessandro Catenazzi, an assistant professor of zoology at SIU-Carbondale, have spent more than 15 years each scouring the park and its surrounding areas for frogs, toads, salamanders and caecilians -- all amphibians -- as well as for reptiles such as snakes, lizards, turtles and caimans. The field work in the park and its buffer zone, augmented by other, more limited surveys published previously, allowed the team to compile a list of 155 amphibian and 132 reptile species, including a handful of species new to science. Taxonomist and coauthor Edgar Lehr, assistant professor of biology at Illinois Wesleyan University, collaborates frequently with von May and Catenazzi on frog taxonomy and studies of amphibian declines and conservation.
The researchers listed the 287 species of reptiles and amphibians in the most recent issue of the journal Biota Neotropica. The previous record for the most diverse protected area for reptiles and amphibians was in Yasuní National Park in Ecuador, which hosts 150 amphibian and 121 reptile species, according to a 2010 study.
"There is no place like Manu where we can preserve such an exceptionally large amount of biodiversity, as well as the evolutionary processes that contribute to maintain and promote biodiversity," said Catenazzi, a former postdoctoral researcher in UC Berkeley's Department of Integrative Biology. "It is our responsibility to make sure this biological legacy is passed on to the next generations."
To assemble the list, the team surveyed multiple elevations and examined hundreds of museum specimens collected at dozens of locations in Manu National Park and its buffer zone. Analysis of DNA sequences and frog calls allowed the team to identify additional species.
World Heritage Site
While the high species diversity can be partially attributed to the large area and steep topographic variation within Manu National Park, the finding is noteworthy, von May said. He and his colleagues estimate that the park represents only 0.01 percent of the planet's land area, but houses 2.2 percent of all amphibians and 1.5 percent of all reptiles known worldwide.
Since its creation 41 years ago, Manu National Park has become recognized as globally irreplaceable: it was designated a UNESCO Biosphere Preserve in 1977 and a World Heritage Site in 1987. Herpetologists -- experts in reptiles and amphibians -- first surveyed the region in the 1970s, primarily along the road that connects the city of Cuzco to villages in the cloud forests of the Kosñipata Valley. Starting in the '80s, research was broadened to include remote lowland rainforest locations, such as Cocha Cashu Biological Station, inside the park. Subsequent expeditions have continued to reveal new species of amphibians and reptiles, especially in the cloud forest and high-Andean grasslands, which are rich in endemic species, Catenazzi said. One of the most recent discoveries was the glass frog Centrolene sabini, the world's 7,000th known amphibian species.
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Despite the fact that 96 percent of marine species perished in the end-Permian extinctions, some 252 million years ago, only one of the 25 benthic lifestyles that then existed actually disappeared when life struggled on into what's called the Triassic period. That made it harder for new groups of benthic animals to evolve in the aftermath, said William Foster and Richard Twitchett of Plymouth University in the U.K. Their study appears in the Feb. 23 issue of the journal Nature Geoscience.
Put in theatrical terms, it's as if the roles in a play survived despite many changes of actors, making it very hard for the overall plot to change much.
“Globally, the Early Triassic benthic ecosystem functioned much like a ship manned by a skeleton crew. Each post was occupied, but by only a few individual taxa (groups),” Foster said.
That skeleton crew appeared to be enough, however, to keep intact the lifestyles that have defined benthic animals ever since.
To come to that conclusion, Foster and Twichett had the daunting task of sorting through the worldwide benthic fossil record from that pivotal time in Earth's history.
Previous studies have looked at the groups that went extinct, of course, as well as how new lifestyles “went viral” and spread through the world, but this is the first to look at the greatest extinction solely terms of animal roles -- or the “ecospace” -- that animals filled.
“We sort of ignored (the animals') names for this study,” explained Foster. One advantage of this approach, he said, is that when the fossil record lacks evidence of a particular animal for a period of time, you can sometimes follow the lifestyle to fill in the blanks.
“The ecospace occupied by a marine organism is characterized by three ecological variables: mobility, feeding mechanism and living location,” explained Martin Aberhan of the Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity in Germany.
None of this means to suggest that the extinction event, which was accompanied by a severe bout of global warming, went entirely unnoticed by sea-floor inhabitants.
Read more at Discovery News
Dubbed by the local press “Sweden's Atlantis” after the fabled island which according to Greek philosopher Plato sank around 9600 B.C. in the Atlantic Ocean, the newly discovered site was in fact some sort of a dump in which nomadic Swedes discarded objects, according to a report by the Swedish daily The Local.
Buried 52 feet below the surface at Hanö, a sandy bay off the coast of Skane County in Sweden, the items include wood pieces, flint tools, animal horns, ropes, a harpoon carving made from an animal bone and the bones of an aurochs and an ancient cattle which became extinct in the early 1600s.
"There's wood and antlers and other implements that were thrown in there," project leader Björn Nilsson, archaeology professor at Södertörn University, told the Local.
Amazingly, the artifacts have been perfectly preserved because of the abundant oxygen-consuming“gyttja” -- a black, gel-like sediment which is formed when peat begins to decay.
"Around 11,000 years ago there was a build up in the area, a lagoon or sorts ... and all the tree and bone pieces are preserved in it. If the settlement was on dry land we would only have the stone-based things, nothing organic," Nilsson said.
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That age should settle a scientific debate over the accuracy of that mineral's internal clock, and cuts the time from when Earth was hit by a Mars-sized body (which led to the formation of the Moon) and the cooling and creation of Earth's first solid crust from 600 million years to 100 million years.
“This, I believe, is the oldest zircon that's ever been dated on Earth,” said John Valley, of the University of Wisconsin in Madison. He and his colleagues have published their findings in the Feb. 23 issue of the journal Nature Geoscience.
Previous dating of the ancient Jack Hills zircons about ten years ago had arrived at ages of about 4.4 billion years, Valley explained. But there were doubts about whether some of the atomic elements used for the dating had moved about in the crystals and thrown off the age by a few hundred million years.
“Whether a grain is 4.3 or 4.4 billion years old, and whether this reflects a primary age, is not a trivial matter,” explained Sam Bowring of the Massachusetts Institute of Technology.
“In the context of the 4.4- to 4.5-billion-year age of the Earth, a difference in age of 0.1 or 0.2 billion years (100 or 200 million years) is enormous in terms of modeling the geochemical evolution of Earth and the formation and recycling of the first continental crust.”
The element in question is an isotope of lead, which is created by the radioactive decay of uranium in zircons.
The age of a grain is figured by measuring the amounts of the parent uranium isotopes compared to the daughter lead isotopes. This is only accurate if no uranium or lead gets into or escapes the zircon.
Researchers were concerned that the very process of uranium decaying -- which fires out a high-speed alpha particle -- might have kicked around lead atoms in the zircons and messed things up.
“If the lead leaves, it can be concentrated somewhere else,” said Valley. “The apparent age where it goes will appear older and where it has left will appear younger. What we've done is solve the lead mobility problem.”
They did it by laboriously counting and mapping clusters of lead atoms in the zircon using what's called atom-probe tomography.
“It's astonishing to be able to do this,” said Valley, “literally counting atoms with an atomic probe.”
Valley and his colleagues found that the lead was indeed getting kicked around, but it wasn't going far enough to throw off the age of the zircon.
“I think it settles it, as far as it's possible,” said Valley.
It also points the way for techniques that can be used to better study zircons from beyond Earth, said Valley. There are, for instance, zircons from meteorites that are older than the Earth -- up to perhaps 4.6 billion years old.
Read more at Discovery News