Dec 5, 2015
Researchers at the University of Pennsylvania have now created the thinnest plates that can be picked up and manipulated by hand.
Despite being thousands of times thinner than a sheet of paper and hundreds of times thinner than household cling wrap or aluminum foil, their corrugated plates of aluminum oxide spring back to their original shape after being bent and twisted.
Like cling wrap, comparably thin materials immediately curl up on themselves and get stuck in deformed shapes if they are not stretched on a frame or backed by another material.
Being able to stay in shape without additional support would allow this material, and others designed on its principles, to be used in aviation and other structural applications where low weight is at a premium.
The study was led by Igor Bargatin, the Class of 1965 Term Assistant Professor of Mechanical Engineering and Applied Mechanics in Penn's School of Engineering and Applied Science, along with lab member Keivan Davami, a postdoctoral scholar, and Prashant Purohit, an associate professor of mechanical engineering. Bargatin lab members John Cortes and Chen Lin, both graduate students; Lin Zhao, a former student in Engineering's nanotechnology master's program; and Eric Lu and Drew Lilley, undergraduate students in the Vagelos Integrated Program in Energy Research, also contributed to the research.
They published their findings in the journal Nature Communications.
"Materials on the nanoscale are often much stronger than you'd expect, but they can be hard to use on the macroscale" Bargatin said. "We've essentially created a freestanding plate that has nanoscale thickness but is big enough to be handled by hand. That hasn't been done before."
Graphene, which can be as thin as a single atom of carbon, has been the poster-child for ultra-thin materials since it's discovery won the Nobel Prize in Physics in 2010. Graphene is prized for its electrical properties, but its mechanical strength is also very appealing, especially if it could stand on its own. However, graphene and other atomically thin films typically need to be stretched like a canvas in a frame, or even mounted on a backing, to prevent them from curling or clumping up on their own.
"The problem is that frames are heavy, making it impossible to use the intrinsically low weight of these ultra-thin films," Bargatin said. "Our idea was to use corrugation instead of a frame. That means the structures we make are no longer completely planar, instead, they have a three-dimensional shape that looks like a honeycomb, but they are flat and contiguous and completely freestanding."
"It's like an egg carton, but on the nanoscale," said Purohit.
The researchers' plates are between 25 and 100 nanometers thick and are made of aluminum oxide, which is deposited one atomic layer at a time to achieve precise control of thickness and their distinctive honeycomb shape.
"Aluminum oxide is actually a ceramic, so something that is ordinarily pretty brittle," Bargatin said. "You would expect it, from daily experience, to crack very easily. But the plates bend, twist, deform and recover their shape in such a way that you would think they are made out of plastic. The first time we saw it, I could hardly believe it."
Once finished, the plates' corrugation provides enhanced stiffness. When held from one end, similarly thin films would readily bend or sag, while the honeycomb plates remain rigid. This guards against the common flaw in un-patterned thin films, where they curl up on themselves.
This ease of deformation is tied to another behavior that makes ultra-thin films hard to use outside controlled conditions: they have the tendency to conform to the shape of any surface and stick to it due to Van der Waals forces. Once stuck, they are hard to remove without damaging them.
Totally flat films are also particularly susceptible to tears or cracks, which can quickly propagate across the entire material.
"If a crack appears in our plates, however, it doesn't go all the way through the structure," Davami said. "It usually stops when it gets to one of the vertical walls of the corrugation."
The corrugated pattern of the plates is an example of a relatively new field of research: mechanical metamaterials. Like their electromagnetic counterparts, mechanical metamaterials achieve otherwise impossible properties from the careful arrangement of nanoscale features. In mechanical metamaterials' case, these properties are things like stiffness and strength, rather than their ability to manipulate electromagnetic waves.
Other existing examples of mechanical metamaterials include "nanotrusses," which are exceptionally lightweight and robust three-dimensional scaffolds made out of nanoscale tubes. The Penn researchers' plates take the concept of mechanical metamaterials a step further, using corrugation to achieve similar robustness in a plate form and without the holes found in lattice structures.
That combination of traits could be used to make wings for insect-inspired flying robots, or in other applications where the combination of ultra-low thickness and mechanical robustness is critical.
Read more at Science Daily
As shown in this short animation of 4 observations made by the spacecraft, a mysterious object can be seen drifting in front of distant stars. This is a Kuiper Belt Object, or KBO, and it is the closest we’ve ever seen such an object that lives in this outer region of our solar system.
After shooting through the Pluto system on July 14, New Horizons dove straight into the Kuiper Belt, a region beyond Pluto that is known to be populated with frozen debris from the solar system’s early formation.
On Nov. 2, mission operators commanded the probe to look in the direction of 1994 JR1, a small 90-mile (150 kilometer) wide object, grabbing this series of images an hour apart. Although JR1 orbits the sun at a distance of 3.3 billion miles (5.3 billion miles), New Horizons was only 170 million miles (280 million kilometers) away, making this the closest observation of a mysterious KBO.
It is hoped that New Horizons will be given enough funds to extend its mission far beyond the Pluto encounter so further observations of KBOs can be made.
After recently making some minor course corrections, New Horizons is now on course to rendezvous with recently-discovered KBO 2014 MU69 on Jan. 1, 2019. So all going well, the tenacious space robot will make a second flyby of an outer solar system object deep inside the Kuiper Belt in a little over 3 years time… if funding is approved.
From Discovery News
Dec 4, 2015
The findings, reported today in the journal Science, help explain why migratory bird numbers are declining despite global efforts to protect them, said researchers who are calling for a greater focus on the needs of migratory species in global conservation planning.
"Migratory species rely on a chain of good quality habitat all the way along their migratory route," said senior author Associate Professor Richard Fuller, a biologist from the University of Queensland.
"If links in that chain are not well protected then some species might not be able to complete their lifecycle."
Migratory birds travel over vast distances each year.
"Some migratory birds are flying to the distance to the Moon and back — not once, not twice, but three times during the course of their life," Dr Fuller said.
He said migration enabled the birds to find the best seasonal feeding and breeding places, and places to fuel up for their journey along the way.
"Often young birds only eat certain types of food and their parents need to be in particular places at the right time to get that food."
Dr Fuller and his colleagues, including PhD student Claire Runge, looked at how well the needs of the world's 1451 species of migratory birds are covered by protected areas.
The researchers collected information on the movement of all migratory birds species at different times of the year, and compared this with maps of protect areas, such as national parks, in different habitat types, including wetlands, Arctic tundra, desert environments, savannas and forests.
"We overlaid those two things on top of each other and asked how well protected each migratory species was across its whole annual cycle," Dr Fuller said.
"We found that more than 90 per cent of species have one or more parts of their lifecycle poorly protected."
For example, the bar-tailed godwit breeds in Alaska, flies across the Pacific to Australia, then north through the Yellow Sea back up to the Arctic, travelling over 10,000 kilometres in one go.
The researchers found that while there was adequate protection of its breeding habitat, the bar-tailed godwit has suffered a loss of intertidal habitats, which it needs for stopovers to fuel its migration.
Evidence suggests this is mainly because of land reclamation activities in the Yellow Sea for urban, industrial and agricultural expansion, the researchers said.
"Migratory bird species are slipping through the net in various countries all around the world and the maps in our paper point to where some of those gaps might be," Dr Fuller said.
Read more at Discovery News
Dated to the end of the 4th century B.C., the burial site was found by a farmer who opened a void in the earth while working with his plow in a field near Città della Pieve, a small town some 30 miles southwest of Perugia.
“It was a totally unexpected discovery. The area is away from the sites visited by tomb robbers and indeed the burial is undisturbed,” Clarita Natalini of the archaeological superintendency of Umbria, told Discovery News.
Finding an undisturbed Etruscan tomb is an extremely rare event that has the potential to reveal more about one of the ancient world’s most fascinating and mysterious cultures.
The Etruscans were a fun- loving and eclectic people who among other things taught the French how to make wine, the Romans how to build roads, and introduced the art of writing into Europe. They began to flourish around 900 B.C., and dominated much of Italy for five centuries.
Known for their art, agriculture, fine metalworking and commerce, they began to decline during the fifth century B.C., as the Romans grew in power. By 300-100 B.C., they eventually became absorbed into the Roman empire.
Since their puzzling, non-Indo-European language was virtually extinguished (they left no literature to document their society), the Etruscans have long been considered one of antiquity’s great enigmas.
Much of what we know about them comes from their cemeteries. Only the richly decorated tombs they left behind have provided clues to fully reconstruct their history.
In this way, the burial in Città della Pieve looks more than promising. As Natalini and her team reached the dromos (the corridor leading to the tomb’s entrance) they found themselves in front of a perfectly sealed double door made from heavy stone.
Once opened, the tomb revealed a 16 square-foot rectangular chamber with two sarcophagi, four marble urns and various grave goods. One of the sarcophagi, made from stone, bears a long inscription.
So far Natalini and colleagues have been able to read the word “Laris.” Lars is a common Etruscan male first name. The stone coffin contains the skeleton of a male individual.
Natalini and her team expect to find more information in the inscription, such as the deceased’s family name, the name of his parents, and possibly his age at death.
The other sarcophagus, covered with painted plaster, also shows an inscription.
Despite the damage, the 2,300-year-old painted coffin, which weights 3 tons and is more than 8 foot long, is still sealed.
“We expect to find another skeleton inside,” Natalini said.
A mysterious marble head, clearly broken at the neck level, has been also found.
“It portrays the beautiful face of a young man. We do not know yet its meaning. Perhaps it was part of a statue that honored one of the deceased,” Natalini said.
Apart from grave goods, which include pottery, miniature votive vases and two intact ceramic jars, likely used to store food for the afterlife, the archaeologists found four urns with cremains.
Made from fine grained alabaster marble, three of them are finely sculpted. The lid portrays the half naked deceased with a flower necklace reclining on two cushions as if at a banquet. He bears a patera, a shallow ritual offering dish, in the right hand.
The use of alabaster marble, the style of the burial and clues from the inscriptions suggest the burial belongs to an aristocratic family from the nearby Etruscan stronghold of Chiusi, Natalini said.
Read more at Discovery News
An hour-long eruption began around 3:20 a.m. local time, sending a lava fountain more than 3,000 feet into the air and coating nearby villages in a layer of ash. Although the eruption forced the closure of the nearby Reggio Calabria airport, there were no reports of damage or injury.
Scientists believe the dramatic lighting that accompanies certain eruptions is the result of positively charged particles that are ejected from the volcano. A second type of volcanic lighting has been observed to form downwind of the ash plume, but that “plume lighting” is not well-understood. Click here to learn more about volcanic lightning.
According to EarthSky, the thick clouds of ash produced during an eruption make it challenging to study the striking phenomenon, but recent advances in radio wave technology are helping scientists observe lightning storms that would otherwise be cloaked in ash.
Towering 10,922 feet over Sicily’s eastern coast, Mount Etna is the tallest active volcano in continental Europe. A series of four nested stratovolcanoes with activity dating back to 1500 B.C., the mountain has been designated as a UNESCO World Heritage Site by the United Nations.
From Discovery News
The universe is filled with a dark matter web — a vast 3-D structure that the majority of galaxies and clusters of galaxies are threaded along. Although we cannot directly see dark matter (as it does not interact with light), we can see its gravitational influence on space-time and we now know this invisible mass accounts for nearly 85 percent of all matter in the cosmos.
Understanding how this dark matter web influenced the earliest galaxies to form after the Big Bang is critical for us to better appreciate the structure and evolution of the modern universe, so the discovery of a cluster of massive starburst galaxies (i.e. galaxies frantically forming new stars) embedded in a junction of dark matter lanes, some 11.5 billion years ago, could help us understand why none of these monstrous early galaxies exist in the modern universe and how massive elliptical galaxies came to be.
Until now, observing the earliest galaxies has been a problem. Typically, these starburst galaxies that existed in the earliest epochs of our universe are hard to observe as they contain huge quantities of obscuring dust. Radio telescopes find it hard to accurately pin down these galaxies’ locations. But these galaxies are known to generate a high flux of submillimeter emissions, a frequency band ALMA is highly sensitive to.
Read more at Discovery News
And no copycat is stranger or more accomplished than the mimic octopus. True to its name, it impersonates a variety of other animals on the fly, morphing from an octopus to a banded sole to a lionfish to a sea snake. But this is no random assemblage of impressions: All of these creatures are toxic or venomous. The mimic octopus isn’t just a copycat—it’s a copycat that’s evolved a strategy far more brilliant than would appear at first glance.
Long ago, the ancestors of octopuses, and indeed the ancestors of all other cephalopods like cuttlefish and squid, took refuge in the safety of their shells. Then something went awry—perhaps a more powerful predator appeared that could make short work of the shells—and the cephalopods were forced to evolve more novel defenses (the nautiluses are the only cephalopods to have retained their shells). The cuttlefish, for instance, is a master of camouflage, blending seamlessly with its surroundings, while squid opt for sheer speed or, you know, growing to over 1,000 pounds in the case of the colossal squid.
But the mimic octopus—not to be confused with the similarly striped but even-better-named wonderpus—has in a way adopted the defenses of venomous and toxic creatures it shares a habitat with. “When they swim up into the water column and hold all the arms around them,” says marine biologist Mark Norman of Australia’s Museum Victoria, “that I believe is mimicry of a lionfish with its banded spines.” And lionfish are not to be messed with. Their dorsal spines deliver a venom powerful enough to cause breathing difficulties in humans.
|A mimic octopus making its getaway while impersonating a lionfish. It is still unclear how lionfish feel about this sort of sendup.|
When the octopus is down on the seafloor it seems to mimic at least two other not-to-be-trifled-with critters. One is the banded sole, a variety of flatfish that looks a bit like a flounder, only it has poison glands at the base of its fins. For this impression, the octopus pulls all of its arms back, forming a sort of teardrop, and jets over the sand.
The other animal is a snake called the sea krait, whose wildly powerful neurotoxic venom can kill you (it’s actually docile and its deadliness isn’t its fault, to be honest—it needs be able to quickly incapacitate the fish it hunts or the things will just swim away). To mimic this one, the octopus shoves six of its arms into a hole in the sand and holds its other two out, giving them a slight wiggle.
|Here a mimic octopus impersonates a sea snake as a fish is all like “eh never mind.”|
And that seems to fit right in with science’s conception of octopuses as particularly intelligent—except that’s all a bit problematic. “Intelligence is a really difficult issue with octopuses,” Norman says. “I’ve gotten into trouble before by saying most of the tests on octopuses demonstrate the lack of intelligence in the researchers.”
The thing is, the notion of intelligence is a human construction, and what might be smart for people isn’t necessarily smart for animals. So what tests should scientists give to octopuses? Having the creatures solve mazes is nice and all, but it’s not like octopuses are scurrying about mazes in nature.
|That’s no banded sole–it’s a mimic octopus that wishes so bad it was a banded sole.|
Of course, it would seem smartest for the octopus to hole up in a crevice like other octopuses. But their mimicry may have evolved in a very “smart” way to help the octopus procure food, not just avoid becoming it.
A creature would be a damn fool to venture out on the seafloor in daylight without some sort of defense. So the sea krait has its deadly bite, which doubles as an offensive and defensive weapon, while the lionfish has its spines. And they advertise this unpleasantness with that wacky-ass Beetlejuice coloration, scaring off predators so they can roam freely looking for food.
By aping these creatures, the mimic octopus muscles into a market few other octopuses can. “It’s colonized the most dangerous habitat you could have as a cephalopod, in that you’ve got very little in the way of defenses and you’re just meat walking around, very edible,” says Norman. “They’ve found a way to forage over those environments during the daytime, relying solely on their capacity to deter predators by their similarity to other species.”
Read more at Wired Science
Dec 3, 2015
Previously, the only known primates to hibernate were lemurs living on the island nation of Madagascar.
The findings come from a paper just published in the journal Scientific Reports by a team of researchers from Vetmeduni Vienna in Austria.
The pygmy slow loris (Nycticebus pygmaeus) is small, at about 7 to 9 inches long and typically weighing about 1 pound. The nocturnal creature lives in trees and, unlike other primates, it can't leap. Its diet includes tree gum, insects, and fruit.
The scientists studied the animal's body temperature in the fall, winter and spring in Vietnam. They found that the creature engaged in episodes of hibernation between December and February that lasted up to 63 hours each.
The researchers suspect both an internal clock mechanism that kicks in during seasons of food scarcity and ambient temperature drops each help induce the hibernation periods.
"In Vietnam, where we studied the animals, there are pronounced seasons," said the study's lead author Thomas Ruf in a statement. "Ambient temperature can drop to 5 centigrade. This is exactly when the probability of animals entering a hibernation episode was highest."
Hibernation can last anywhere from days to months and helps many species conserve energy during periods when food is tough to come by. It's characterized by decreased metabolism, a sharp drop in body temperature, lowered heart rate, and slowed breathing. Colloquially, it's often considered a kind of deep sleep.
Three species of lemur on Madagascar conserve water by hibernating during the dry season. But outside of that location, hibernation in primates has not until now been documented.
Read more at Discovery News
The tiny creatures, measuring from one to 2.5 centimeters (up to one inch), were found in Santa Catarina state, a zone of mountains and forested valleys that is considered an important center of biodiversity.
"The great importance of this discovery is that this forest serves as an incubator for the origin of species," said Marcos Bornschein, a researcher with the Federal University of Parana, who helped identify the creatures.
"It's a laboratory of huge importance for the mapping and conserving and understanding of biological processes," he said.
The Atlantic forest once covered most of Brazil's coastline, but only eight percent has been preserved. Most of the country's 204 million people live along the coast.
The toads are dark brown with red markings and are speckled with warts. They eat ants and mites and during digestion create a chemical in the skin that can poison predators, principally snakes.
"They are not dangerous to humans," Bornschein said. "During the fieldwork, some researchers felt a numbing in their finger ends after touching them, but nothing more."
The discovery of the toads, all classified as part of the Melanophryniscus genus, was described Wednesday in the scientific journal Plos One.
The article said that the discovery of the toads in a fairly restricted geographical area -- they were found between the cities of Garuva and Blumenau, about 100 kilometers (60 miles) apart -- suggested that the species "might be severely underestimated."
But it added that the "status of these species is of particular concern, given that one of them is at risk of extinction."
From Discovery News
Called Verba Appia, the audio-only app is available for free on iOS, Android, and Windows Phone both in the Italian and English version. It is produced by Rome’s archaeological superintendency with Mondadori Electa publishing house and lets visitors leave geolocalized audio messages — similar to the graffiti left in the past — while entertaining them with finely crafted audio dramas.
The aim is to get more visitors to the historic area while creating a social audio network that will be treated as a permanent cultural addition to the site.
“Forget audio guides. This is a totally new way of interacting with the cultural heritage,” Fabrizio Funtò, executive producer of Studio MCM, who conceived and developed the app, told Discovery News.
Rome’s gateway to the east, the Appian Way, or Regina Viarum (the queen of all roads) was Europe’s first super highway. Paved with blocks of lava or stone, it was originally created as a large military road in 312 B.C. by Appius Claudius Caecus and stretched for some 350 miles to the Adriatic port of Brindisi.
The app focuses on the part of the Appian Way running from the Colosseum to the outermost suburbs of Rome over a distance of about 5.5 miles. A concentration of ruins of Roman villas, tombs, mausoleums, inscriptions, towers, catacombs and aqueducts make this area the world’s largest archaeological site.
“With Verba, the ancient road becomes a super highway of communication. Visitors are taken into a universe of localized contents and stories,” Funtò said.
Using the smartphone’s GPS sensor, the app localizes the user’s position and sends dedicated content.
“We are not talking of the usual information offered by audio guides, but rather mini audio dramas that will make visitors experience the best of this site,” Rita Paris, the Italian state archaeological official responsible for the Appian Way, told Discovery News.
Paris and her team carefully researched some 50 audio dramas. Hosted in Microsoft’s Azure cloud platform, the plays feature special effects and original soundtracks.
Lined with cypresses and pines, the Appian Way becomes even more atmospheric as the ancient monuments start to “speak” revealing the stories of their occupants — from the Roman period, to the Middle Ages and modern times.
There is Cecilia Metella, the daughter-in-law of Marcus Crassus, who shared the triumvirate with Pompey and Julius Caesar, there is Commodus, the “gladiator emperor” who trained in a miniature arena, and there is 13-year-old Tulliola, whose hovering ghost fuels the Appian legends.
More modern stories include the discovery of love letters contained within two lead tubes dated 1929, and hidden near the Doric tomb at the 4th mile of the Appian Way.
“So many stories, even modern ones, can be found along this road. For the inconsolable lover, the Appian Way must have inspired a sense of eternity to which he could entrust his passionate letters,” Paris said.
In line with such spirit, the app lets visitors leave audio comments at each visited spot.
“It’s a kind of social audio where everybody can post messages, just like on Facebook and Twitter,” Funtò said.
The audio comments can be made public, shared with a group or kept completely private and can be heard only by those in the same geographical space. They will remain as “digital graffiti” to record the passage of visitors.
Read more at Discovery News
Since these weird phenomena were first discovered nearly a decade ago, astronomers have been at a loss to explain what they could be. Everything from the exotic (aliens?!) to the “mundane” (supernovas, boo) have been cited as possible culprits. Now, by painstakingly analyzing the signal of one of these pulses, astronomers may be on the trail to finally working out what the heck is rumbling the cosmos.
FRBs last only a fraction of a second but pack a hell of an energetic punch. Because they are so transient, however, they’re not easy to record. They flash, and they’re gone. Also, as they have often traveled vast distances, their signals are stretched and blurred out. According to a Carnegie Mellon University press release, though only a few have been detected, astronomers think the universe sees tens of thousands of these pulses every single day, but to see one you need to be looking at the right place at the right time.
After analyzing hundreds of hours of data from the National Science Foundation’s (NSF) Green Bank Telescope (GBT) in West Virginia, researchers stumbled across the most detailed signature of a FRB recorded to date. From this signal, they were able to gain a measure on its magnetic “fingerprint” to reveal the environment it must have been spawned.
“We now know that the energy from this FRB passed through a dense, magnetized region shortly after it formed,” said astronomer Kiyoshi Masui, of the University of British Columbia and the Canadian Institute for Advanced Research. “This significantly narrows down the source’s environment and type of event that triggered the burst.”
What’s dense and extremely magnetized? Supernovas and star forming regions. But exactly where did this FRB originate? So far, the detected FRBs have originated in random parts of the sky; there appears to be no pattern, and this particular FRB was no different. But the one thing that set this event apart — dubbed “FRB 110523″ — is the detail held in its signal. Now the detective work could begin.
Finding FRB 110523 was no easy task; the researchers had to scan through 40 terabytes of radio data looking for the split-second pulses. They found 6,000 candidate FRBs in the data, but the vast majority were of too low a quality for analysis or confirmation. Another problem is that, after travelling potentially billions of light-years to reach Earth, these pulses become smeared or blurred, an effect known as “dispersion delay.” This has the effect of blending FRBs into the radio data, hiding it from view. The researchers therefore had to create a computer algorithm to track down these smeared-out pulses.
“Hidden within an incredibly massive dataset, we found a very peculiar signal, one that matched all the known characteristics of a Fast Radio Burst, but with a tantalizing extra polarization element that we simply have never seen before,” said Jeffrey Peterson, a faculty member in Carnegie Mellon’s McWilliams Center for Cosmology.
Until now, only 15 FRBs have been definitively identified, all of which fell within the 1.2-1.5 GHz frequency range. FRB 110523 has a lower frequency, falling within the 700-900 MHz range.
“I feel extremely lucky to have identified the 16th (FRB),” said Hsiu-Hsien Lin, also from Carnegie Mellon, who made the identification of FRB 110523. “Not only is this the first FRB in this frequency range, our FRB has provided us with a great deal of information that help us to better understand this astrophysical phenomenon.”
This particular signal appeared like a diamond in the rough. Not only was its signal clear, it also held a polarization fingerprint (called Faraday rotation, a corkscrew-like twist in electromagnetic radiation) from where it was born.
“This tells us something about the magnetic field that the burst traveled through on its way to us, giving a hint about the burst’s environment,” said Masui. “It also gives the theorists a bit more to work with when they come up with explanations for these bursts.”
Measurements of the dispersion delay of FRB 110523 revealed the source of the signal was 6 billion light-years away (it was therefore triggered 6 billion years ago, when the universe was a little over half the age it is now), but additional analysis revealed the size of the source region — it came from another galaxy. But that’s not all.
Even more information was gleaned from the pulse’s dispersion delay; it revealed the signal passed through two distinct regions of ionized gas. One of these regions was very close to the source (within the source’s galaxy) and most likely “a nebula surrounding the source or the environment near the center of a galaxy.”
“Taken together, these remarkable data reveal more about an FRB than we have ever seen before and give us important constraints on these mysterious events,” said Masui. “We also have an exciting new tool to search through otherwise overwhelming archival data to uncover more examples and get closer to truly understanding their nature.”
Read more at Discovery News
The planet, which is about 11 times bigger than Jupiter, has been a puzzle since its discovery in 2014. It is located so far from its parent star — about 16 times farther away than Pluto orbits the sun — that astronomers first thought it must have formed like a star, condensing out of its own cloud of gas and dust.
But a new study indicates a much more violent past. The planet, known as HD 106906b, seems to have been shot out from a cozier perch in the star’s planet-forming region to its distant backyard by an as-yet undetected missing massive planet or by a passing star.
Evidence for the extreme migration comes from a newly discovered belt of comets orbiting the star, much like the Kuiper Belt circles the sun.
But the star’s comet belt is severely lopsided, raising suspicions that the same gravitational forces that disturbed the comets led to HD 106906b’s exile.
Astronomers are now on the hunt for dusty material from the comets that may have been swept into orbit around the planet.
“We think that the planet itself could have captured material from the comet belt, and that the planet is surrounded by a large dust ring or dust shroud,” astronomer Paul Kalas, with the University of California Berkeley, said in a statement.
“We conducted three tests and found tentative evidence for a dust cloud, but the jury is still out,” Kalas said.
Meanwhile, the story of HD 106906b has scientists wondering if our solar system took a similar beating in its youth, possibly losing a planet or two in the process.
Read more at Discovery News
Dec 2, 2015
Magdalena Sorger of North Carolina State University and author of the study describing this unusual behavior, was collecting trap-jaw ants in Borneo with a field assistant in 2012, when they noticed something "extremely strange," she told Live Science.
Sorger was used to seeing Odontomachus rixosus, a species of trap-jaw ant, perform jaw jumps, which typically propelled the ants backward (sometimes onto a scrutinizing scientist's face). But the ants were doing something quite different.
"They were jumping forward," said Sorger, who is an evolutionary ecologist. "I'd never seen them do that before."
To "jump" with their jaws, trap-jaw ants stretch their massive mandibles wide and then snap them shut. Acting like a spring-loaded catapult, the closing snap shoots the ant out of harm's way.
Other ant species employ equally novel solutions for getting around. Wingless tropical ants drop from their tree habitats when threatened, using their hind legs as rudders to help them glide to safety. Some ant species are swimmers, while some ford watery obstacles by linking their legs to form living rafts and bridges. Still others can "limbo," navigating under low-hanging barriers without losing speed.
But leg jumping in ants is exceptionally rare — of 326 ant genera, only three are known to jump with their legs. Once Sorger noticed this forward jumping in the Borneo trap-jaws, she started looking more closely at how they behaved when she collected them.
"I saw them jumping almost every time," she recalled.
Initially, Sorger suspected the ants might be jumping because that was an easier way to navigate their leafy habitat. She returned to Borneo in 2013 specifically to document and analyze leg-jumping, and soon realized that the ants jumped in response to disturbances.
"They would try to escape from you by hopping forward," Sorger told Live Science.
Sorger found that touching the ants' legs induced jumping. Some of those were jaw jumps, but most of the time they were jumping with their legs. And Sorger observed that leg-jumping had clear advantages. The jaw jumps, while swift and powerful, were difficult for the ants to control. The motion typically propels the ants backward, flipping them upside-down and requiring a moment of recovery time, which could be critical in escaping a hungry predator, she said.
Read more at Discovery News
Males who succeeded in snaring a mate were those that put in the most effort and paid the female a lot of attention, according to the study published today in Royal Society Proceedings B.
The study confirmed for the first time that strong sexual selection by females has played a role in the evolution of ornamentation and complex signalling among some male species.
Dr Michael Kasumovic, at the University of New South Wales, said biologists had spent decades investigating how female preference drives the development of ostentatious traits in males.
At its most extreme these traits can include intricate dances, bright coloration and songs such as in birds of paradise.
"It was always assumed that in general these traits do exist because of female preference," Dr Kasumovic said.
However to date there had been little empirical evidence to support this theory.
He said the research team — which was led by Madeline Girard and included Dr Damian Elias, at the University of California, Berkeley — aimed to fill this gap by focusing on the peacock spider, Maratus volans, because its suite of traits rivaled that of the bird of paradise.
The tiny jumping peacock spider — which measures just three to five millimeters — is endemic to Australia. The male is known for an abdomen flap that is intensely coloured and like the peacock lifts up and fans out during courtship.
They also perform an intricate ritual that includes vigorous leg waving and also generate a vibrating beat.
For the study, Ms Girard collected 120 spiders from the wild and allowed them to court in a natural environment within the laboratory.
The team filmed the courtship using high-definition cameras and used a laser vibrometer to measure the vibrations created by the male spider.
Dr Kasumovic said during 64 mating trials with virgin females, only 16 males were successful.
In 22 trials with mated females, none of the females re-mated.
He said the success by the males was dependent on "how vigorously a male dances and how much attention he pays to his mate".
The fact the mated females would not re-mate suggested they became more selective, Dr Kasumovic said.
His advice to the male peacock spider: "Try your best the first time, as once a female is mated, she gets pickier."
Dr Kasumovic said the female — which will attack and kill the male if she is not happy — did give warnings that the male should try harder.
This involved her wiggling or waving her abdomen, which resulted in the male either backing off or trying harder.
Read more at Discovery News
And some of these giant designs located in Jordan’s Azraq Oasis seem to have an astronomical significance, built to align with the sunrise on the winter solstice.
Those are just some of the findings of new research on these Middle East lines, which were first encountered by pilots during World War I. RAF Flight Lt. Percy Maitland published an account of them in 1927 in the journal Antiquity, reporting that the Bedouin called the structures “works of the old men,” a name still sometimes used by modern-day researchers.
The “works of the old men” include wheels, which often have spokes radiating out from the center, kites (stone structures used for funnelling and killing animals), pendants (lines of stone cairns) and meandering walls, which are mysterious structures that meander across the landscape for up to several hundred feet.
The works “demonstrate specific geometric patterns and extend from a few tens of meters up to several kilometers, evoking parallels to the well-known system of geometric lines of Nazca, Peru,” wrote an archaeological team in a paper published recently in the Journal of Archaeological Science. (Peru’s Nazca Lines date to between 200 B.C. and A.D. 500.)
They “occur throughout the entire Arabia region, from Syria across Jordan and Saudi Arabia to Yemen,” wrote the researchers. “The most startling thing about the ‘Works’ is that they are difficult to identify from the ground. This stands in contrast to their apparent visibility from the air.”
New research on the Middle East lines was published recently in the Journal of Archaeological Science and the journal Arabian Archaeology and Epigraphy. Live Science also got an advance copy of an article set to be published in the journal Antiquity.
Tests indicate that some of the wheels date back around 8,500 years, a prehistoric time when the climate was wetter in parts of the Middle East.
Using a technique called optically stimulated luminescence (OSL), archaeologists dated two wheels at Wadi Wisad, in the Black Desert of Jordan. One wheel dated back 8,500 years, while the other wheel had a mix of dates that suggest it was built about 8,500 years and was remodeled or repaired around 5,500 years ago.
At the time these wheels were built, the climate in the Black Desert was more hospitable, and Wadi Wisad was inhabited. “Charcoal from deciduous oak and tamarisk [a shrub] were recovered from two hearths in one building dated to ca. 6,500 B.C.,” wrote researchers in a forthcoming issue of Antiquity.
Spatial analysis of the wheels showed that one cluster of wheels, located in the Azraq Oasis, has spokes with a southeast-northwest orientation that may align with sunrise during the winter solstice.
“The majority of the spokes of the wheels in that cluster are oriented for some reason to stretch in a SE-NW direction,” researchers wrote in the Journal of Archaeological Science. This points to “where the sun rises during the winter solstice.”
Whether this alignment was intentional is unknown, researchers wrote in the journal article. “As for the rest of the wheels, they do not seem to contain any archaeoastronomical information.”
What were they used for?
The two dated wheels “are simple in form and not very rigidly made, according to geometric standards,” said Gary Rollefson, a professor at Whitman College in Walla Walla, Washington. “They contrast sharply with some other wheels that appear to have been set out with almost as much attention to detail as the Nazca Lines.”
It’s possible that different wheels may have served different uses, Rollefson said. In the case of the two dated wheels, “the presence of cairns suggests some association with burials, since that is often the way of treating people once they died.” Rollefson is careful to point out that “there are other wheels where cairns are entirely lacking, pointing to a different possible use.”
Rollefson is co-director of the Eastern Badia Archaeological Project. His team is hoping to excavate a few of the cairns, which are located within the wheels, in the next few years.
Visible from the sky
Why people in prehistoric times would build wheel-shaped structures that can’t be seen well from the ground remains a mystery. No balloon or glider technologies existed at that time. Additionally, researchers say that climbing to a higher elevation to view them was probably not possible, at least not in most cases.
Though the wheels are often difficult to make out on the ground, they are not invisible. “Granted, one can’t see the finished product standing at ground level, but one can still determine a general geometric configuration,” Rollefson told Live Science.
He said that to create the more precisely designed wheels, people might have used a long rope and stake.
Saudi Arabia wheels
Wheels located in Saudi Arabia and Yemen look different than those found farther north, a team with the Aerial Photographic Archive for Archaeology in the Middle East (APAAME) has found.
They’ve been investigating wheels, and other “works of the old men,” by using free satellite imagery that is available through Google Earth and Bing. They are also using historical aerial images taken of Saudi Arabia and Yemen during the 20th century.
The circles tend to be small and have only one or two bars instead of spokes, said David Kennedy, of the University of Western Australia, who co-directs the project. Some of the “wheels” are actually shaped like squares, rectangles or triangles, he said.
One type of wheel structure actually looks like a bull’s-eye, according to an image of the structure that Kennedy sent to Live Science. Three triangles point toward the bull’s-eye wheel, and there are small piles of stones that lead from the three triangles to the wheel. Kennedy calls it “a central bull’s-eye tomb with, in this case, three triangles each with at least a part of a connecting line of stone heaps running to the center.”
At present, the archaeologists are not able to conduct fieldwork or aerial imaging (using planes or helicopters) in Saudi Arabia or Yemen.
Another form of “works of the old men,” which Kennedy and his team have found in Saudi Arabia, is of structures that he calls “gates.”
So far, 332 gates have been found in Saudi Arabia (none are known to exist farther north). The gates “consist of two short thick walls or heaps of stones, between which one or more connecting walls stretch,” wrote researchers in an article published recently in the journal Arabian Archaeology and Epigraphy. The researchers note that, “from above, these features resemble an old-fashioned barred gate laid flat.” The longest gate is over 500 meters (1,640 feet), but most are much smaller.
Scientists don’t know how far back the gates date, nor their purpose. “I coined the term ‘gate’ for no better reason than that I needed a convenient label to describe them and they reminded me of the sort of field gates I saw all around in my rural childhood in Scotland,” said Kennedy.
Read more at Discovery News
Although the rocks may look the same — and all of them originated from the same layer in the planet’s interior — they’re not all the same chemically, with differences in trace elements and isotopic composition. How these dissimilar rocks could come from the same place has long been a puzzle to scientists.
Now, however, a group of present and former University of Arizona researchers have figured out why. They’ve created a model of dynamics in the Earth’s mantle — the hot, semi-molten layer below the crust. It indicates that plumes of hot rock originate in the lower mantle and then physically interact with chemically distinct piles of material above them before they reach the surface. That, in turn, produces the variability in the chemistry of rocks that’s seen in Hawaii.
Their findings are described in a recent article in the journal Nature Communications.
“This model provides a platform for understanding links between the physics and chemistry that formed our modern world as well as habitable planets elsewhere,” Curtis Williams, the study’s lead author, said in a release.
The differences in OIB samples provides scientists with new insights into the chemical structure and temporal evolution of Earth’s interior.
“In particular, it means that the Earth’s mantle — the hot rock below Earth’s crust but above the planet’s iron core — is compositionally heterogeneous,” said Williams, who now is doing post-doctoral work at the University of California, Davis. “Understanding when and where these heterogeneities are formed and how they are transported through the mantle directly relates to the initial composition of the Earth and how it has evolved to its current, habitable state.”
From Discovery News
The new observations come courtesy of ultraviolet observations performed by the Hubble Space Telescope, suggesting that the star was once five times more massive than our own Sun. No one is quite sure how this star got so hot, and its chemical composition still needs to be analyzed.
"The strange thing about this white dwarf (and its cooler twin H1504+65) is the surface composition," wrote lead author Klaus Werner of the University of Tübingen in Germany, in an e-mail to Discovery News. "It is carbon and oxygen without hydrogen and helium. Currently, there is no good explanation for this phenomenon. Commonly, white dwarfs have either hydrogen-dominated or helium-dominated atmospheres."
A little bit is known about RX J0439.8-6809 by modelling its history. It appears the star's temperature peaked at more than 400,000 degrees Celsius about 1,000 years ago. It was spotted in X-ray images about 20 years ago because it was so hot, but it originally was believed to be in the Large Magellanic Cloud, a galaxy outside of our own.
"Future X-ray surveys (eRosita) combined with optical surveys might reveal more of this kind of white dwarf with unusual surface composition," Werner added. "The search for trace elements (other metals) might give hints as to the evolutionary history."
From Discovery News
Dec 1, 2015
The location at the Duntulm Formation of Cairidh Ghlumaig on the Isle of Skye, includes hundreds of footprints and handprints made by plant-eating sauropods during the Jurassic period, reports a study published in the new issue of the Scottish Journal of Geology.
Stephen Brusatte of the University of Edinburgh’s School of GeoSciences told Discovery News that the 44,092-pound dinosaurs, which measured over 49 feet long, “left their footprints in an ancient lagoon 170 million years ago.”
Lagoons are stretches of salt water separated from the sea by a coral bank or, in this case, low sandy dunes. To this day, locals and tourists alike are drawn to the scenic and tranquil sandy beaches at the Isle of Skye.
“Surprisingly, the new discovery shows that these big dinosaurs spent lots of time in coastal areas and shallow water,” Brusatte said. “We used to think that they were purely land-dwellers.”
The footprints reveal that the beach-loving dinosaurs were distant relatives of more well known species, such as Brontosaurus and Diplodocus. The largest of the prints measures about 27.5 inches.
The prints represent the first sauropod tracks to be found in Scotland. Until now, the only evidence that sauropods lived in Scotland came from a small number of bone and teeth fragments.
These footprints, along with other tracks found recently at additional sites around the world, reveal that sauropods spent a lot of time hanging out at coastal areas, wading in shallow water. Now the question is: what else were they doing there, and how might the location have affected their diet?
That is not known yet, but the recently discovered site is already gaining dino fans.
Read more at Discovery News
The eight fossilized peach endocarps, or pits, date back more than two and a half million years. They were found by Tao Su, associate professor at Xishuangbanna Tropical Botanical Garden, when road construction near his house in Kunming, capital of Yunnan in southwest China, exposed a rock outcrop from the late Pliocene.
Preserved within the Pliocene layers, the fossils looked “strikingly modern,” according to Su. With colleague Peter Wilf, a professor of paleobotany at Pennsylvania State University, and others, Su detailed his findings last week in Scientific Reports.
“The fossils are identical to modern peach endocarps, including size comparable to smaller modern varieties, a single seed, a deep dorsal groove, and presence of deep pits and furrows,” the researchers wrote.
The discovery suggests that peaches, juicy and sweet, much like the ones we eat today, were a popular snack long before the humans arrived on the scene.
After analyzing the morphological characters of the pits, the researchers concluded they belonged to the genus Prunus and proposed a new species name, Prunus kunmingensis.
“We aim to provide an unambiguous epithet for the fossils in the absence of a whole-plant reconstruction,” the researchers said.
A popular tree fruit worldwide, with an annual production near 20 million tons, peach (Prunus persica) is widely believed to have originated in China. However, much of the evolutionary history of the fruit remains unknown.
The oldest evidence had been found within archaeological records dating back roughly 8,000 years, but no wild population has ever been found.
The discovery of Prunus kunmingensis supports the belief that the peach originated in China.
“The peach was a witness to the human colonization of China. It was there before humans, and through history we adapted to it and it to us,” Wilf said.
Several tests carried out at Penn State University confirmed that the pits, preserved in the Pliocene rocks along with many other plant fossils, are more than 2.5 million years old.
Electron microscope analysis showed that the seeds inside the flattened pits were mostly replaced by iron oxides, while radiocarbon dating of the fossils showed them to be older than the range of radiocarbon dating, which is about 50,000 years.
The researchers explained that peaches evolved their modern morphology under natural selection, with animals and primates snacking on the fleshy fruit and dispersing their seeds.
Much later, peach size and variety increased through domestication and breeding.
Read more at Discovery News
Instead, men and women's brains are an unpredictable mishmash of malelike and femalelike features, the study concludes. Even in brain regions previously thought to show differences based on sex, variability is more common than consistency.
"Our study demonstrates that although there are sex/gender differences in brain structure, brains do not fall into two classes, one typical of males and the other typical of females, nor are they aligned along a 'male brain–female brain' continuum," the study researchers wrote today (Nov. 30) in the journal Proceedings of the National Academy of Sciences.
"Rather, even when considering only the small group of brain features that show the largest sex/gender differences, each brain is a unique mosaic of features, some of which may be more common in females compared with males, others may be more common in males compared with females, and still others may be common in both females and males."
The new research is the first to examine sex differences in the brain as a whole. If the brain is truly sexually dimorphic, coming in a male and a female form, it should be consistently different between the two sexes, Tel Aviv University psychobiologist Daphna Joel and her colleagues wrote.
Consider the peacock, with its sexually dimorphic tail: The difference in color and size is consistent between the sexes – there's no subset of peahens brandishing iridescent purple feathers.
Clearly, brains don't fit this pattern; there is far more variation in brains within sexes than between them, a fact that has been known for a long time, said Rebecca Jordan-Young, a professor of women's gender & sexuality studies at Barnard College in New York and author of "Brain Storm: The flaws in the science of sex differences" (Harvard University Press, 2010).
Many neuroscientists had already concluded that brains are checkered with a mix of male- and femalelike structures, said Jordan-Young, who was not involved in the new study.
But despite this variation, there could still be a continuum of male-type and female-type brains, Joel and her colleagues reasoned, so long as the gender differences between structures are consistent between men and women. They decided to put the question to a test.
The researchers combed through more than 1,400 magnetic resonance images (MRI) from multiple studies of male and female brains, focusing on regions with the largest gender differences.
In the first analysis, using brain scans from 169 men and 112 women, the researchers defined "malelike" and "femalelike" as the 33 percent most extreme gender-difference scores on gray matter from 10 regions. Even with this generous designation of "male" and "female" scores, the researchers found little evidence of the consistency they would need to prove brain dimorphism.
Only 6 percent of brains were internally consistent as male or female, meaning all 10 regions were either femalelike or malelike, the researchers found. Another analysis of more than 600 brains from 18- to 26-year-olds found that only 2.4 percent were internally consistent as male or female, while substantial variability was the rule for more than half (52 percent).
In other words, there were very few individuals whose brain regions were all malelike or femalelike. And there was no clear continuum between the two endpoints.
Instead, across both gray and white matter and in connectivity patterns, brains are so overlapping that calling a particular form male or female is meaningless, Joel and her colleagues wrote.
"Our results demonstrate that even when analyses are restricted to a small number of brain regions (or connections) showing the largest sex/gender differences, internal consistency is rare and is much less common than substantial variability (i.e., being at the one end of the 'maleness-femaleness' continuum on some elements and at the other end on other elements)," they wrote.
"Anyone who is aware of current data on brain sex differences appreciates that there is no such thing as a monolithic 'male brain' or 'female brain,' in much the same way as there is no such thing as a male heart and a female heart," said Lise Eliot, a neuroscientist at Rosalind Franklin University in Chicago and author of "Pink Brain, Blue Brain: How Small Differences Grow Into Troublesome Gaps — And What We Can Do About It" (Mariner, 2010).
Eliot, who was not involved in the new study, said the research was an "innovative approach" to sifting through brain gender differences. While statistical differences between the genders exist, she told Live Science, the new study shows that the distribution of malelike and femalelike attributes is patchy, not uniform.
Indeed, previous studies have found large areas of overlap in the structure of male and female brain structures, even when population-level gender differences are found.
"Every individual could have part of both men and women in them," radiologist Ragini Verma told Live Science in 2013 after finding differences in connectivity between male and female brains.
The findings are consistent with an emerging line of research on the hormonal control of brain development, Joel and her colleagues wrote. Early on, neuroscientists had viewed sex-specific hormones as the key to sex difference in the brain, with testosterone "masculinizing" the brain and estrogen "feminizing" it.
Though hormonal influences are important, the real story is far more complex, according to a 2011 review in Nature Neuroscience.
A growing body of evidence suggests that development is a give-and-take among genetic, environmental and epigenetic (above the genome) factors, all of which are acting in parallel and influencing one another in complicated ways. Different brain regions react in different ways to sex-specific influences, which are not limited to estrogen and testosterone, that review found.
Meanwhile, environmental influences such as prenatal or early-life stress can feed back into this process, again altering how the brain develops.
Read more at Discovery News
Boyalife Group and its partners are building the giant plant in the northern Chinese port of Tianjin, where it is due to go into production within the next seven months and aims for an output of one million cloned cows a year by 2020.
But cattle are only the beginning of chief executive Xu Xiaochun's ambitions.
In the factory pipeline are also thoroughbred racehorses, as well as pet and police dogs, specialised in searching and sniffing.
Boyalife is already working with its South Korean partner Sooam and the Chinese Academy of Sciences to improve primate cloning capacity to create better test animals for disease research.
And it is a short biological step from monkeys to humans -- potentially raising a host of moral and ethical controversies.
"The technology is already there," Xu said. "If this is allowed, I don't think there are other companies better than Boyalife that make better technology."
The firm does not currently engage in human cloning activities, Xu said, adding that it has to be "self-restrained" because of possible adverse reaction.
But social values can change, he pointed out, citing changing views of homosexuality and suggesting that in time humans could have more choices about their own reproduction.
"Unfortunately, currently, the only way to have a child is to have it be half its mum, half its dad," he said.
"Maybe in the future you have three choices instead of one," he went on. "You either have fifty-fifty, or you have a choice of having the genetics 100 percent from Daddy or 100 percent from Mummy. This is only a choice."
Xu, 44, went to university in Canada and the US, and has previously worked for US pharmaceutical giant Pfizer, and in drug development.
Presenting cloning as a safeguard of biodiversity, the Tianjin facility will house a gene bank capable of holding up to approximately five million cell samples frozen in liquid nitrogen -– a catalogue of the world's endangered species for future regeneration.
Boyalife's South Korean partner Sooam is already working on a project to bring the woolly mammoth back from extinction by cloning cells preserved for thousands of years in the Siberian permafrost.
Sooam also serves a niche market recreating customers' dead pet dogs, reportedly for $100,000 a time.
Sooam founder Hwang Woo-Suk was a national hero with his own postage stamp before being embroiled in controversy a decade ago after his claims to be the first in the world to clone a human embryo were discredited.
Hwang, who created Snuppy, the world's first cloned dog, in 2005, lost his university position, had two major papers retracted, and was accused of crimes ranging from violation of bioethics laws to embezzling research funds.
Earlier this year he was quoted in South Korea's Dong-A Ilbo newspaper saying that his firm was planning a cloning joint venture in China "because of South Korea's bioethics law that prohibits the use of human eggs".
"We have decided to locate the facilities in China in case we enter the phase of applying the technology to human bodies," he was quoted as saying.
For now, Xu seeks to become the world's first purveyor of "cloned" beef, breeding genetically identical super-cattle that he promises will taste like Kobe and allow butchers to "slaughter less and produce more" to meet the demands of China's booming middle class.
Cloning differs from genetic modification, but its application to animals would enable the firm to homogenise its output.
"Everything in the supermarket looks good –- it’s almost all shiny, good-looking, and uniformly shaped. For animals, we weren't able to do that in the past. But with our cloning factory, we choose to do so now," Xu said.
"Remember, this is a food. We want it to be uniform, very consistent, very premium quality," he added.
There is controversy over whether cloned beef is safe for human consumption -- research by the US Food and Drug Adminstration says that it is, but the European parliament has backed a ban on cloned animals and products in the food chain.
The UN's Food and Agriculture Organization has yet to review the issue.
Han Lanzhi, a GMO safety specialist at the Chinese Academy of Agricultural Sciences, said Boyalife’s claims about the safety, scope and timeline of their operations were alarming -- and implausible.
Read more at Discovery News
Nov 30, 2015
A comprehensive look at 29 types of dinosaur eggs suggests that most dinosaurs buried their eggs in nests covered with dirt and vegetation, a tactic also used by modern-day crocodiles.
But some small theropods (mostly meat-eating, bipedal dinosaurs) that were closely related to birds used another strategy: They laid their eggs in open nests, much like most birds do today, the researchers found.
"The evolution of open nests and brooding behavior could have allowed small theropod dinosaurs, and obviously birds, to move to other nesting locations other than on the ground," which may have helped their evolutionary success, said study co-researcher Darla Zelenitsky, an assistant professor of paleontology at the University of Calgary in Canada.
Researchers have spent years piecing together limited evidence about how dinosaurs raised their young, but there are few dinosaur egg fossils to study, said study lead author Kohei Tanaka, a doctoral student in the faculty of science at the University of Calgary.
"Dinosaur nest structures and nesting materials are usually not preserved in the fossil record," Tanaka said in a statement. "In the past, this lack of data has made working with dinosaur eggs and eggshells extremely difficult to determine how dinosaurs built their nests and how the eggs were incubated for hatching young."
Luckily, researchers can compare the fossilized eggs of dinosaurs to those of the dinosaur's closest living relatives: crocodiles and birds. Crocodiles bury their eggs in nests on the ground and cover them with sand, dirt and rotting vegetation, which keeps the eggs warm. In contrast, birds usually lay their eggs in open nests, and brood on them during incubation.
These modern eggs — specifically, the number and size of the pores in their shells — gave researchers clues about the nest type. They collected data on the eggs and nests of more than 120 modern species of birds and crocodiles, and found stark differences between the two.
Buried eggs tended to have a high porosity, or larger and more holes in the shell that allow for vapor and gas exchange between the outside world and the embryo. However, burying the eggs helps to retain their humidity and moisture as the embryo develops inside, Zelenitsky told Live Science.
Once the researchers figured out that buried eggs tend to have high porosity, and open-nest eggs tend to have low porosity, the researchers turned their attention to the fossilized dinosaur eggs. The eggs were ancient, ranging from 150 million to 70 million years old, but they still retained crucial details, such as porosity.
Most dinosaurs, such as the long-necked sauropods, less-developed theropods and possibly the plant-eating ornithischians, had high-porosity eggs, and likely buried their eggs in nests, the researchers found. But more developed theropods, such as the maniraptorans, had eggs with low porosity, and probably laid their eggs in open nests, they said. It's unclear whether these small theropods also brooded on top of their nests, but there are fossils of small dinosaurs doing just that, which suggests that some did, Zelenitsky said.
However, these well-developed small theropods didn't lay their eggs exactly like today's modern birds. Other fossil evidence shows that early open-nesting dinosaurs still partially buried their eggs, she said.
Read more at Discovery News
Tribrachidium was a denizen of the shallow seas about 550 million years ago, during the late Ediacaran period. It looked like a disc with three tentaclelike arms protruding from its flat top. Oddly, Tribrachidium had three-fold symmetry, meaning three segments were mirror images of each other. For comparison, humans have two-fold, or bilateral, symmetry, and starfish have five-fold symmetry. Nothing alive today has three-fold symmetry.
"Because we have no obvious modern comparison, that's made it really hard to work out what this organism was like when it was alive — how it moved, if it moved, how it fed, how it reproduced," said Imran Rahman, a research fellow at the University of Bristol, in the United Kingdom, who led the study.
Now, Rahman and his colleagues have used fluid dynamics to show that Tribrachidium probably was a suspension feeder, meaning it ate floating organic particles out of the water. Modern suspension feeders include brittle stars, many crustaceans and bivalves.
Tribrachidium lived about 40 million years before the Cambrian explosion, when life on Earth expanded and diversified relatively rapidly. Scientists once thought Ediacaran organisms were very simple, Rahman told Live Science, but the new findings paint a more complex picture of this time period. It's possible that Tribrachidium even altered its environment.
Suspension feeding "mobilizes organic material that was being carried around in the water column," Rahman said. "It can increase passage of sunlight through water and potentially increase oxygenation, as well."
There's no evidence that Tribrachidium could move around, so researchers thought perhaps it fed by osmotrophy, or absorbing dissolved nutrients from the water. Alternatively, it could have captured and digested larger particles by suspension feeding.
To demystify Tribrachidium's feeding habits, Rahman and his colleagues created a 3D digital model of the organism based on a cast of a fossil from south Australia. (Tribrachidium fossils have also been found in Russia and Ukraine.) They then subjected this digital model to virtual currents mimicking what would have existed in its shallow seafloor environment.
The currents slowed as they hit Tribrachidium, and then eddied in the organism's wake. These eddies served to recirculate the water back toward Tribrachidium, directing it into the nooks between its three symmetrical arms. It's very likely that gravity then settled out any waterborne particles into these crevices, allowing Tribrachidium to snag the particles and chow down.
"This is really exciting, because we didn't really have any good evidence of suspension feeding in organisms of this time period previously," Rahman said.
Other Ediacaran creatures remain mysterious, with equally weird body designs. Some, like Tribrachidium, are disc-shaped, Rahman said. Others look like fronds. He said he'd like to use similar models of fluid dynamics to figure out how those creatures might have fed.
Read more at Discovery News
A new survey of the Valley of the Temples just outside Agrigento, Italy, reveals the 2,500-year-old temples were not deliberately aligned to the rising sun, as generally believed. A variety of factors, not all of them being astronomical, inspired the ancient architects.
“Alignment was widely determined by urban layout and morphological aspects of the terrain as well as religious connections,” Giulio Magli, professor of archaeoastronomy at Milan’s Polytechnic University, told Discovery News.
Magli and colleagues Robert Hannah, at the University of Waikato, New Zealand, and Andrea Orlando, at the Catania Astrophysical Observatory, conducted the research with funding from the Ente Parco della Valle dei Templi. Their findings are published on the Cornell University physics Web site, arXiv.org.
Known as the temple of Demeter and Persephone, the shrine is among a World Heritage-listed collection of temples that once stood in full glory in Akragas, later to be called Agrigento.
“One can only imagine the spectacle at the temple. The full moon near the winter solstice – the longest night of the year – culminates very high in the sky and remains in the sky the longest,” Magli said.
Akragas was one of the most important Greek colonies in Sicily, and the homeland of the philosopher Empedocles (490–430 BC).
Empedocles was the first to divide matter into the four elements of earth, fire, water and air. He also observed that the moon shines with light reflected from the sun.
Today the Valley of the Temples consists of the remains of 10 Doric temples dedicated to Greek gods, goddesses and heroes such as Heracles, Olympic Zeus, Demeter and Persephone, Juno, Concordia, Vulcan, Aesculapius.
Their orientation, as well that of all Greek temples, has been debated for nearly two centuries. Academics wondered whether they were aligned with astronomic events like the sunrise on specific days of the year.
Magli and colleagues measured the alignment of all the Greek temples in the valley, and showed that at least four of them are orientated in accordance with the town’s grid along the cardinal directions — irrespective of the solar date to which they would match due to the horizon.
“For such temples, only a general rule imposing the facade towards the eastern horizon was applied. However, they were not orientated toward the rising sun on specific days of the year,” Magli said.
One of the shrines, the temple of Juno, was aligned to the stars in the Delphinus constellation.
On the contrary, the temple of Zeus, one of the largest temples of the Greek world before earthquakes and Carthaginian raids, was orientated topographically in accordance with the street grid.
“Incredible as it may seem, we have been unable to find this simple explanation in the literature,” the researchers wrote.
Now incorporated in the Medieval church of San Biagio, the temple of Demeter and Persephone is preceded by a fountain sanctuary with sacred caves where votive deposits, including a statuette representing Persephone, were found.
Persephone and her mother Demeter, the goddess of nature, were the key figures in the Eleusinian mysteries representing the myth of Persephone, who was abducted by Hades to be his wife in the underworld.
The mysteries celebrated Persephone’s reunion with her mother, in a cycle with three phases, the “descent,” the “search” and the “ascent.”
“We know very little about the relationship between astronomy and those secret religious rites. A connection with the moon-orientated temple is possible and will be at the center of further research,” Magli said.
The attribution of the temple to Demeter and Persephone was also confirmed by the presence of two small circular altars located in a corridor formed between the rock cut to the north and the side of the temple.
One altar has a central well, known as bothros, which was found filled with broken kernoi, or ritual vessels of Demeter.
A relatively large esplanade can be found on the back of the temple. It was obtained artificially through the construction of huge retaining walls on the south side and an accurate excavation and leveling of the rock on the north side.
“We can imagine a nocturnal procession coming up from the fountain sanctuary and reaching the temple, in front of which, however, there is not enough space to house worshipers,” Magli and colleagues said.
Read more at Discovery News
The seismologists had participated in a meeting a week before the earthquake to discuss the dangers of recent smaller tremors in the town of L’Aquila. The original judge had found that their risk assessment of the threat of a larger earthquake had been superficial and inadequate, resulting in townspeople being wrongly reassured that they would be safe in their homes when the earthquake struck.
The complicated case began in 2010 when the six were investigated and charged, resulting in six-year prison sentences handed down in 2012; the convictions were appealed and overturned last year. That appeal was itself appealed by prosecutors who asked that the convictions be reinstated. This final ruling by the Supreme Court puts an end to the matter for all involved.
According to a Science Insider report, “Six scientists convicted of manslaughter … were definitively acquitted by Italy’s Supreme Court of Cassation in Rome following lengthy deliberations by a panel of five judges. But the court upheld the conviction of a public official tried alongside them.”
The judges found that that official, Bernardo De Bernardinis — at the time part of Italy’s civil protection department — had in fact wrongly reassured the public, while the six seismic scientists had simply stated that the chance of a major earthquake remained the same and thus had neither raised undue alarm nor downplayed the risk of the quake that soon followed. De Bernardinis’s jail time was reduced to two years.
Life is inherently risky and fraught with dangers ranging from sunlight to cigarettes to eating meat to driving in a car. Minor risks are routinely blown out of proportion in news media reports — the recent WHO finding that meat is carcinogenic is a good example –while the public regularly ignores (or tolerates) much greater risks to their health and lives when they smoke or fail to wear seat belts, for example.
The public often expects certainty from scientists about what will hurt or kill them—a certainty which science cannot provide.
From Discovery News