Apr 11, 2015
For many people, and the religious in particular, the phenomenon of near-death experience — assuming it’s real and not simply a result of a dying brain’s hallucinatory interpretation of a flood of brain chemicals — validates their belief in the afterlife and heaven. Many books have been written by people who claim to have come back from the brink of death and seen God and heaven (though earlier this year the best-selling memoir “The Boy Who Came Back From Heaven” was admitted by its author to have been faked).
Scientific evidence, however, suggests that the experience is not a spiritual or metaphysical one, but instead a chemical one.
A new study in which researchers induced anoxia in rats offers more support for near-death experiences (NDEs) as happening inside the dying brain and being interpreted as an out-of-body or spiritual experience.
The researchers examined neurotransmitters, changes in brain and heart electrical activity and brain-heart connectivity. They concluded, “Asphyxia stimulates a robust and sustained increase of functional and effective cortical connectivity, an immediate increase in cortical release of a large set of neurotransmitters… . These results demonstrate that asphyxia activates a brainstorm, which accelerates premature death of the heart and the brain.”
According to an article at MedicalDaily.com, the researchers found that “the brain is much more active during the dying process than in the waking state… In the 30-second period after the animal’s hearts stopped beating, the researchers observed an immediate release of more than a dozen neurochemicals, while high-frequency brainwaves called gamma oscillations increased.
“This activity seemed to trigger a connection between the brain and the heart… . [Lead author Jimo] Borjigin believes a similar, elevated level of brain activity may also happen during the human experience of ‘near death’ and it is this that gives rise to a heightened state of consciousness, including the visions experienced by survivors of cardiac arrest.”
This “brainstorm,” or cascade of neurotransmitter chemicals, can cause benign hallucinations such as those reported in NDEs. This new study joins several others implicating anoxia as a contributing (if not causative) factor to near-death experiences. Researcher Borjigin had conducted previous research with similar findings in 2013, published in the Proceedings of the National Academy of Sciences.
Causes of Near-Death Experiences
When examining near-death experiences, it’s important to understand that no one has survived true clinical death (which is why the experiences are called “near-death”).
Many people have been revived after their heart stopped beating for short periods of time — around 20 minutes or more — but no one has actually come back from the dead. Anyone revived from true brain death would be permanently and irreparably brain damaged and unable to report their experiences.
Researcher Susan Blackmore, author of “Dying to Live: Near-Death Experiences” (Prometheus Books, 1993), notes that many NDEs (such as euphoria and the feeling of moving toward a tunnel of white light) are common symptoms of oxygen deprivation in the brain.
A 2001 article published in Trends in Cognitive Sciences by neuroscientist Dean Mobbs, of the University of Cambridge’s Medical Research Council Cognition and Brain Sciences Unit, and Caroline Watt, of the University of Edinburgh, found that “contrary to popular belief, research suggests that there is nothing paranormal about these experiences. Instead, near-death experiences are the manifestation of normal brain function gone awry, during a traumatic, and sometimes harmless, event.”
In fact, the researchers noted that many classic NDE symptoms are reported by people who were never actually in danger of dying and thus are not necessarily correlated with near-fatal trauma.
A 2010 study in the journal Critical Care found that of 52 heart attack patients, 11 reported having NDEs. Between one in four and one in ten heart attack survivors report some form of near-death experience.
Surprisingly, only a minority of people who are actually near death report near-death experiences; they are the exception, not the rule. This may be because not all circumstances that may bring a person near death necessarily involve conditions under which anoxia would be expected. A near-drowning victim, for example, would be more likely to experience an NDE than someone whose lung functions were normal but whose injury or condition involved the brain or another major organ.
Read more at Discovery News
The Florida Fish and Wildlife Service said Friday it is “increasing efforts to locate and remove them,” particularly along canals in Palm Beach County, north of Miami.
The lizards can be mistaken for iguanas and typically grow to five feet (1.5 meters) long. Their mottled coloring may be yellow, olive or brown.
Nile monitors have been known to eat cats as well as other small mammals, burrowing owls, fish and frogs, according to biologist Jenny Ketterlin Eckles of the Fish and Wildlife Service.
“Because their diet is so varied, we are assessing whether this species may have an impact on Florida’s native wildlife,” she said.
Since the Nile monitors’ breeding season is approaching, officials said this is a good time to ramp up their patrols and called on local citizens to report sightings and “secur(e) small pets.”
They asked anyone who sees a Nile monitor, whether basking in the sun by the water or exploring their backyard, to take a picture and report it to IveGot1.org.
“Members of the public are advised not to attempt to capture a Nile monitor themselves,” warned the Fish and Wildlife Service.
“Monitors are not innately aggressive but like any wild animal they may defend themselves if aggravated or threatened.”
Read more at Discovery News
Apr 10, 2015
Researchers found the fossil in 2010 on a beach in Mar del Plata, a city on the eastern coast of Argentina. To their delight, the fossil is the most complete skeleton of a terror bird ever found, with more than 90 percent of its bones preserved, said the study's lead researcher, Federico Degrange, an assistant researcher of vertebrate paleontology at the Centro de Investigaciones en Ciencias de la Tierra and the Universidad Nacional de Córdoba in Argentina.
The scientists named the new species Llallawavis scagliai: "Llallawa" because it means "magnificent" in Quechua, a language native to the people of the central Andes, and "avis," which means "bird" in Latin. The species name honors the famed Argentine naturalist Galileo Juan Scaglia (1915-1989).
Given its extraordinary condition, the fossil has helped researchers study the terror bird's anatomy in detail. The specimen is the first known fossilized terror bird with a complete trachea and complete palate (the roof of the mouth). It even includes the intricate bones of the creature's ears, eye sockets, brain box and skull, providing scientists with an unprecedented look at the flightless bird's sensory capabilities.
An analysis of L. scagliai's inner ear structures suggests the terror bird likely heard low-frequency sounds, an advantage for predators that hunt by listening for the low rumble of their prey's footsteps hitting the ground, the researchers said. The new findings also suggest that the terror bird communicated using low-frequency noises, the researchers added.
"That actually tells us quite a bit about what the animals do, simply because low-frequency sounds tend to propagate across the environment with little change in volume," said Lawrence Witmer, a professor of anatomy at Ohio University who has worked with Degrange before, but was not involved in the new study.
"Low-frequency sounds are great for long- communication, or if you're a predator, for sensing the movements of prey animals," Witmer told Live Science.
This skill puts L. scagliai in good company. Other animals that can or could hear low-frequency sounds include Tyrannosaurus rex, crocodiles, elephants and rhinos, Witmer said.
The researchers also looked at the bird's skull, and found that it was more rigid than in other birds. This could have been to the bird's advantage, the scientists said, since a rigid skull could have helped the terror bird slam prey with its large beak.
"Terror birds didn't have a strong bite force, but they were capable of killing prey just by striking up and down with the beak," Degrange said.
Read more at Discovery News
Made of soil and stone and dating to the late fifth or early sixth century, the tomb was found near the coastal city of Gyeongju. The site was the capital of the ancient kingdom of Silla, which flourished for nearly a millennium, from 57 B.C. to 935 A.D., producing 56 monarchs, intricately crafted gold ornaments and beautiful Buddhist temples.
According to the archaeologists, leg bones and teeth indicate that one skeleton belonged to a woman in her 30s.
“She wore a belt which appears to be decorated with gold earrings and gold leaf,” the Cultural Heritage Administration said in a statement.
Position of bones and teeth of the man, who was possibly younger than the woman, suggest he lay in parallel position, his head adjacent to hers.
The woman was also buried with jade green jewels and a threaded necklace made of beads.
In a separate room within the tomb, the archaeologists unearthed a sword, pottery and horse riding equipment, all thought to have belonged to the woman.
Matching historical records about the Silla dynasty, the finds indicated the female was probably a noblewoman who rode horses and was used to handle weapons.
Throughout the Silla kingdom, women enjoyed a relatively high status — the dynasty produced three reigning queens.
Researchers believe the tomb was built for the noblewoman since no accessories were related to the man – a strong indicator he was the human sacrifice.
“This is not the first case where a male sacrifice is buried in a female’s tomb,” researcher Kim Kwon-il told Korea’s JoongAng Daily.
“However, male sacrifices were often buried in the room where the artifacts were, as guards, so to speak, for the dead.”
Read more at Discovery News
Bright and massive stars were spotted circling the 4-million-solar-mass behemoth more than a decade ago, sparking a debate within the astronomy community. Did they migrate inward after they formed? Or did they somehow manage to form in their original positions?
Most astronomers had said the latter idea seemed far-fetched, given that the black hole wreaks havoc on its surroundings, often stretching any nearby gas into taffylike streamers before it has a chance to collapse into stars. But the new study details observations of low-mass stars forming within reach of the galactic center. The findings lend support to the argument that "adult" stars observed in this region formed near the black hole.
The new evidence for ongoing star formation near the black hole is "a nail in the coffin" for the theory that the stars form in situ, said lead author Farhad Yusef-Zadeh, of Northwestern University. The observations, if accurate, make it unlikely that the stars migrated from elsewhere, the researchers said.
Birth Near a Black Hole
Stars are born within clouds of dust and gas. Turbulence within these clouds give rise to knots that begin to collapse under their own weight. The knots grows hotter and denser, rapidly becoming protostars, which are so-named because they have yet to start fusing hydrogen into helium.
But a protostar can rarely be seen. It has yet to generate energy via nuclear fusion, and any faint light it does produce is often blocked by the disk of gas and dust still surrounding it.
So, when Yusef-Zadeh and his colleagues used the Very Large Array in New Mexico to scan the skies near the central supermassive black hole, they didn't spot the protostars but rather the disks of gas and dust surrounding them.
"You could see these beautiful cometary-shaped structures," Yusef-Zadeh told Space.com. Intense starlight and stellar winds from previously discovered high-mass stars had shaped these disks into cometlike structures with bright heads and tails. Similar structures (called bow shocks) can be seen anywhere young stars are being born, including the famous Orion Nebula.
"There is, of course, one big catch here — and that is that the tidal force on the black hole is so strong that it's hard to see how these stars would form," Yusef-Zadeh said. "Many people think that star formation is forbidden near a supermassive black hole. But nature finds a way."
Astronomers have managed to find a way as well. Over the last decade, they've come up with two scenarios, both of which use the nearby black hole to simulate star formation.
In the second scenario, a cloud gets stretched into a taffylike streamer. But as this happens, the gravitational tide from the nearby black hole does two different things. "It disrupts in one direction, but it squeezes in another direction," Yusef-Zadeh said. It's this squeezing, or compressing, that would trigger star formation within the long streamer, Yusef-Zadeh added.
Both scenarios explain why stars encircling the monster black hole, called Sagittarius A*, are found in two rings, or disks, as opposed to random placements.
But some astronomers remain cautious.
"The center of our galaxy is a unique and extreme environment very different from our local solar neighborhood and the rest of the Milky Way," said Jessica Lu, an astronomer at the University of Hawaii's Institute for Astronomy. It's therefore crucial that astronomers don't jump to any conclusions.
"While these bow shocks have similar shapes to protostars seen in the nearby Orion cluster, there are other ways to produce these bow shocks around small clumps of gas," Lu told Space.com in an email.
A Place for Planets
Some scientists who do think that stars — even low-mass stars — are forming within a few light-years of supermassive black holes are now starting to wonder if planets are forming there, too.
Typically, a disk circling a protostar will break up into clumps of gas and dust that later become full-fledged planets. But in such an extreme environment, the wind from nearby stars (the same winds that are responsible for the cometlike shapes of the disks seen by Yusef-Zadeh and his colleagues), may also steal mass from these disks. Yusef-Zadeh and his colleagues estimate that there could be enough material left in those disks to form planets.
Read more at Discovery News
|A female Pimpla disparis wasp doing what she does best: Injecting an egg into a pupa so her young can devour it from the inside out.|
That said, we’re certainly not the brutal parasitic wasp Pimpla disparis, whose females inject their eggs into living moth pupae. After the eggs hatch, they devour their hosts from the inside out before emerging triumphantly from the cocoons. And woe to the female disparis, who will find several males waiting for her birth, all trying to muscle each other out and hump the damn cocoon before she’s even out of the thing. This is just birth, sex, have babies. And it’s all about swapping some very special spit. (Technically speaking, insects don’t have “spit” or “saliva” as much as they have “mandibular secretions.” But I’m not going to call it that for fear of sounding like a chucklehead—well, more of a chucklehead than usual.)
I appreciate people like entomologist Mike Hrabar, because people like Mike get very expensive video cameras and point them at parasitic wasps injecting other creatures with their eggs. That’s the fruits of his labor above. Well, more accurately it’s the fruits of the wasp’s labor. That needle-like structure is her ovipositor (literally “egg placer”), and she’s not just using it to inject her young into the hapless moth pupa. She’ll also swirl it around a bit to get the insect version of blood, known as hemolymph, flowing out of the pupa, which she then drinks up. Developing those eggs, after all, takes a lot of energy, and she could use the bonus protein. The pupa certainly won’t be needing it, considering what’s about to happen next.
The wasp is specifically looking to inject its young into moths in the process of pupating, or the cocoon phase. “And then the primary larvae of the disparis basically swims inside the hemolymph of the developing moth, and it just eats it, munch munch munch, until the whole moth is eaten out from the inside,” says Hrabar. To the outside observer, the cocoon looks normal throughout this process. But instead of splitting open to reveal a moth, out comes an adult wasp—not quite as normal-looking.
|Two males wait for a female to emerge from a cocoon.|
There may be plenty of other cocoons about, so how does the male know to pick the right one? Well, in addition to giving off a bit of a smell, the developing larvae seem to be quite flirty. “The parasitoid might actually be communicating with the adult males by sonic vibration,” says Hrabar. “It actually spins within the puparium periodically, and makes these little vibrating sounds.” It even seems like the female may react to males, spinning as they fly by.
|“Playing hard to get” is a concept that is almost entirely lost on male disparis wasps.|
It’s this kind of scheming that makes wasps so scary-sophisticated. The jewel wasp, for instance, stabs into a cockroach’s brain and injects chemicals that remove its free will, allowing the wasp to drag it into a burrow, lay an egg on it, and seal the tomb up. When the egg hatches, it burrows into the cockroach and eats it from the inside out. And there are all kinds of wasps out there up to similar seriously bad behavior: The parasitic ichneumonidae family, which disparis belongs to, tallies tens of thousands of species worldwide.
For all of their plotting, though, the male disparis can end up hitting on another male, because while the male can tell if there’s a developing larva in a cocoon, he has a hard time telling the gender. “So they’re scrambling around and it just turns into this big tussle of wasps,” says Hrabar. “And then they realize, Oh, no this is male here, and they all disperse. But if it is a female, then she gets mated quickly and generally never mates again.”
|That oh-so-alluring spit—really mandibular secretions.|
Problem is, males also utilize their spit when chewing out of a cocoon, so you end up with the occasional aforementioned male-on-male sexiness. But a female’s saliva has just a little bit more of the chemicals responsible for the scent than a male’s, and indeed Hrabar finds that statistically, males are slightly more likely to home in on a female than another dude.
Read more at Wired Science
Apr 9, 2015
The remains, described in the latest issue of the journal PeerJ, are of the large carnivorous tyrannosaur Daspletosaurus, which suffered numerous injuries during its lifetime and was partially eaten after it died.
The clincher is that paleontologists believe that members of Daspletosaurus’ own species inflicted all of the damage.
“This animal clearly had a tough life suffering numerous injuries across the head including some that must have been quite nasty,” lead author David Hone from Queen Mary, University of London, said in a press release.
He added, “The most likely candidate to have done this is another member of the same species, suggesting some serious fights between these animals during their lives.”
Daspletosaurus lived around 77 million years ago in North America. The victim studied by the researchers hailed from what is now Alberta, Canada. It was an older teenager when it bit the dust, so it hadn’t grown to full size yet. Still, this was a large animal. At death it measured about 20 feet long and weighed approximately 1,102 pounds.
Analysis of this dinosaur’s skull uncovered numerous injuries that had previously healed.
Hone explained that, although not all of the injuries can be attributed to bites, several are close in shape to the teeth of tyrannosaurs. One bite to the back of the head had broken off part of the skull and left a circular tooth-shaped puncture though the bone.
According to the researchers, the fact that alterations to the bone’s surface indicate healing means that the injuries were not fatal and the animal lived for some time after they were inflicted.
The poor dinosaur’s life took a turn for the worse later, though. The preservation of the skull and other bones, as well as damage to the jaw bones show that the dinosaur died young and began to decay. Shortly thereafter, a large tyrannosaur — probably from the same species — chomped into the dead teen dino and presumably ate at least part of it.
Read more at Discovery News
So far, the archaeologists have excavated seven tombs containing at least 171 mummies from the site, now called Tenahaha.
The tombs are located on small hills surrounding the site. "The dead, likely numbering in the low thousands, towered over the living," wrote archaeologist Justin Jennings, a curator at Toronto's Royal Ontario Museum, in a chapter of the newly published book "Tenahaha and the Wari State: A View of the Middle Horizon from the Cotahuasi Valley" (University of Alabama Press, 2015).
Before rigor mortis set in, the mummies had their knees put up to the level of their shoulders and their arms folded along their chest, the researchers found. The corpses were then bound with rope and wrapped in layers of textiles. The mummies range in age from neonate fetuses to older adults, with some of the youngest mummies (such as infants) being buried in jars. While alive the people appear to have lived in villages close to Tenahaha.
The mummified remains were in poor shape due to damage from water and rodents. Additionally, the researchers found some of the mummies were intentionally broken apart, their bones scattered and moved between the tombs. In one tomb the scientists found almost 400 isolated human remains, including teeth, hands and feet.
"Though many individuals were broken apart, others were left intact," Jennings wrote in the book. "People were moved around the tombs, but they sometimes remained bunched together, and even earth or rocks were used to separate some groups and individuals." Some grave goods were smashed apart, while others were left intact, he said.
Understanding the selective destruction of the mummies and artifacts is a challenge. "In the Andes, death is a process, it's not as if you bury someone and you're done," Jennings told Live Science in an interview.
For instance, the breakup and movement of the mummies may have helped affirm a sense of equality and community. "The breakup of the body, so anathema to many later groups in the Andes, would have been a powerful symbol of communitas (a community of equals)," wrote Jennings in the book. However, while this idea helps explain why some mummies were broken up, it doesn't explain why other mummies were left intact, Jennings added.
Radiocarbon dates and pottery analysis indicate the site was in use between about A.D. 800 and A.D. 1000, with the Inca rebuilding part of the site at a later date.
Tenahaha, with its storerooms and open-air enclosures for feasting and tombs for burying the dead, may have helped villages in the Cotahuasi Valley deal peacefully with the challenges Peru was facing. Archaeological research indicates that the villages in the valley were largely autonomous, each likely having their own leaders.
Research also shows that between A.D. 800 and A.D. 1000 Peru was undergoing tumultuous change, with populations increasing, agriculture expanding and class differences growing, Jennings said. At sites on the coast of Peru,archaeologists have found evidence for violence, with many people suffering cranial trauma (blows to the head), Jennings said. In some areas of Peru, scientists have found pottery containing drawings of fanged teeth and human trophy skulls (skulls that could have been taken in battle) the researchers note.
At Tenahaha, however, there is little evidence for violence against humans, and pottery at the site is decorated with what looks like depictions of people smiling, or "happy faces," as archaeologists referred to them.
Read more at Discovery News
Consisting of a virtually complete, fossilized hominin skeleton in an excellent state of preservation, the Altamura Man was discovered by a group of speleologists in 1993 in the karstic cave of Lamalunga, near the town of Altamura in Puglia. The area is rich in prehistorical findings, including a trail of dinosaur footprints.
The remains “represent one of the most extraordinary hominin specimens ever found in Europe,” Giorgio Manzi, professor of paleoanthropology and human ecology at Rome’s Sapienza University, David Caramelli, associate professor of anthropology at the University of Florence, and their colleagues wrote in the Journal of Human Evolution.
“It is of great interest that mtDNA was sufficiently preserved to permit paleogenetic analysis,” they added.
The Altamura Man was found by chance when cavers spotted a 26-foot-deep well. Inside was a tunnel that opened into a large cavity, with other tunnels branching out from it.
One of the tunnels, about 200 feet long, led to another cave, rich with stalagmites. There, encrusted in a corner and looking like a large piece of coral, was a skeleton lying on its back.
Only the skull, which appears upside down, and part of a shoulder were visible. The rest of the body is incorporated into calcite concretions.
Researchers assume the unfortunate hominid fell in a well and remained trapped there, dying of starvation or from lack of water intake. The skeleton was then covered with droplets of limestone that helped preserve it for millennia.
“Although other fossil samples of Homo neanderthalensis can be found in Europe and the Near East, none can equal the excellent state of preservation and the completeness of the Altamura Man,” Manzi said.
The cave’s remoteness and the fossil’s condition have meant that since the discovery, the Altamura Man has remained undisturbed.
“For many years after its discovery, the only information we had on this extraordinary fossil skeleton was based primarily on on-site photographs and observations, which were biased by the presence of calcite formations,” the researchers wrote.
Beginning their work six years ago, Manzi and colleagues finally obtained permission to remove a piece of bone from the skeleton.
“The sample consists of the articular portion of the right scapula,” Manzi and his colleagues said.
“In contrast to most of the bones of the main assemblage, it was free from major concretion apart from a superficial film of calcite,” they added.
Read more at Discovery News
As it turns out, though, researchers at Okinawa Institute of Science and Technology Graduate University in Japan have found that fairy circles share a similar pattern with something tiny and seemingly completely unrelated to them: human skin cells.
“It’s a completely amazing, strange match,” OIST professor Robert Sinclair, who heads the school’s mathematical biology unit, said in a press release.
While the location of fairy circles in the desert may seem random, it turns out that they closely match the distribution pattern of skin cells. Researchers took satellite images of fairy circles, and then used a computer to draw lines halfway between each pair of circles to designate invisible boundaries, much like cell walls. The computer then counted how many neighbors surround each fairy circle. They then compared that number to previous researchers’ calculations about skin cells.
The results were startlingly close to identical. Most fairy circles and skin cells have six neighbors, but the percentage with four, five, six, seven, eight and nine neighbors is essentially the same as the skin cells.
The big question is why this similarity exists, and the researchers don’t yet have an answer for it. Even so, ”the fact that they are similar is already very important,” Sinclair said. “This is suggesting there may be such types of patterns that cover really different size scales.”
Various explanations — none conclusively proven — have been proposed for fairy circles, ranging from zebras rolling around on the ground to ants and termites, to grass-killing gases. In 2013, scientists proposed that they might be caused by subsurface competition for resources among plants.
From Discovery News
By surveying nearly 2,000 spiral galaxies — observed by the Hubble Space Telescope and other space and ground-based telescopes — with properties similar to the Milky Way, we’ve not only gained a valuable insight to how our galaxy looked in the past, we’ve found out that our sun, in the grand galactic scheme of things, appears to have been a late bloomer.
The further astronomers look into the universe, the longer into the past they can see. As light travels at a finite speed (the speed of light), studying a galaxy 1 billion light-years away corresponds to a time when the universe was 1 billion years younger than it is now. So by surveying Milky Way-like galaxies at different distances from us, we can see how our galaxy may have looked in the past.
And by doing this, astronomers have created a timeline and identified when the Milky Way likely had the most intense period of stellar birth.
“This study allows us to see what the Milky Way may have looked like in the past,” said Casey Papovich, of Texas A&M University in College Station, lead author of the study published in the April 9 edition of The Astrophysical Journal. “It shows that these galaxies underwent a big change in the mass of its stars over the past 10 billion years, bulking up by a factor of 10, which confirms theories about their growth. And most of that stellar-mass growth happened within the first 5 billion years of their birth.”
Our sun, however, only started to form about 5 billion years ago, meaning that our star formed when the galaxy was well past its frenzied star birth boom of 10 billion years ago.
But this certainly was no bad thing and may even be a key factor as to why our star system has a rich variety of planets and is probably why the chemistry for life is here in abundance.
Several generations of stars have come and gone, and before the formation of the sun, many stars that formed during the frenzied period of star birth used up their fuel and exploded as supernovae. Supernovae, combined with other energetic stellar events, formed the elements heavier than hydrogen and helium, elements that are essential for the formation of metal rich stars and, by extension, the rocky worlds that orbit them.
Read more at Discovery News
Apr 8, 2015
Researchers captured the aquatic footage at Antarctica's Ross Ice Shelf with a new remotely operated vehicle (ROV), dubbed Icefin. The ROV is capable of diving 0.9 miles (1.5 kilometers) below sea level and conducting 1.9-mile-long (3 km) surveys, they said.
First, the researchers had to cut a 12-inch hole through about 66 feet (20 m) of ice. Then, they dropped Icefin through the hole, and directed it to dive down another 1,640 feet (500 m) to the seafloor, they said.
Earlier underwater vehicles in Icefin's class could dive only a few hundred meters, a limiting factor given that the Southern Ocean surrounding Antarctica can be up to 3.1 miles (5 km) deep.
"What truly separates Icefin from some of the other vehicles is that it's fairly slender, yet still has all of the sensors that the scientists … need," Mick West, the robot's principal research engineer and a senior research engineer at the Georgia Tech Research Institute, said in a statement. "Our vehicle has instrumentation aboard both for navigation and ocean science that other vehicles do not."
For instance, since GPS doesn't work under Antarctica's thick ice, Icefin uses a navigation system known as SLAM (simultaneous localization and mapping). SLAM allows the robot to triangulateits position based on its range and the features around it, such as those on the seafloor below it or the ice above it.
"Using algorithms such as SLAM allows us to construct a map of the unknown under-ice environment," West said. "When you can do that, you can begin to get a 3D picture of what's going on under the water."
In spite of Antarctica's harsh environment, Icefin's videos showed an active community of organisms thriving on the seafloor. Such footage may help scientists learn how animals survive in extreme locations, and understand how Antarctica's ice shelves are changing amidst warming conditions, the researchers said.
"We saw evidence of a complex community on the seafloor that has never been observed before, and unprecedented detail on the ice-ocean interface that hasn't been achieved before," said Britney Schmidt, an assistant professor of earth and atmospheric sciences at Georgia Tech and the principle investigator of the Icefin project.
Icefin may even help scientists search for life on other planets. For instance, Jupiter's moon Europa has ice-capped oceans that are remarkably similar to Antarctica's ice-covered waters, the researchers said.
Read more at Discovery News
The Act states in part, “Subject to the approval of the Lieutenant Governor in Council and with prior review by the Minister, the Council may make regulations, (a) prescribing standards of practice respecting the circumstances in which homeopaths shall make referrals to members of other regulated health professions; and (b) prescribing therapies involving the practice of homeopathy, governing the use of the prescribed therapies and prohibiting the use of therapies other than the prescribed therapies in the course of the practice of homeopathy.”
Homeopathy was invented around 1796 by a doctor named Samuel Hahnemann. He believed—contrary to modern pharmaceutical knowledge—that medicines become more effective the more they are diluted. Homeopathic solutions are often so literally watered-down that they don’t contain a single molecule of the original medicine or substance: the patient is drinking nothing but water. Nonetheless many patients swear by the treatments and believe that they have been cured of both minor and major diseases through homeopathic treatment.
Homeopathy: Consistently Ineffective
Homeopathy has been extensively studied and researchers have concluded that it does not work. In 2010 the British Science and Technology Select Committee conducted an examination of whether homeopathy has any medical or scientific validity; its report concluded:
“Given that the existing scientific literature showed no good evidence of efficacy—that further clinical trials of homeopathy could not be justified…. The Committee carried out an evidence check to test if the Government’s policies on homeopathy were based on sound evidence….The Government acknowledges there is no evidence that homeopathy works beyond the placebo effect (where a patient gets better because of their belief in the treatment.”)
Just last month the Australian government’s National Health and Medical Research Council assessed the efficiency of homeopathy for treating health conditions. It reported:
“This assessment was based on: an overview of published systematic reviews by an independent contractor; an independent evaluation of information provided by homeopathy interest groups and the public; and consideration of clinical practice guidelines and government reports on homeopathy published in other countries…. “Evidence on homeopathy was collected by identifying systematic reviews which evaluated the effectiveness of homeopathy in treating health conditions in humans. In total, 57 systematic reviews were identified that contained 176 individual studies. Studies were only considered by NHMRC if they compared a group of people who were given homeopathic treatment with a similar group of people who were not given homeopathic treatment (controlled studies).”
This use of control groups was important to help verify that any effects found were due to some active ingredient in the homeopathic solution and not, for example, a function of the placebo effects. The expert panel’s conclusion was both clear and devastating to homeopathy: “Based on the assessment of the evidence of effectiveness of homeopathy, NHMRC concludes that there are no health conditions for which there is reliable evidence that homeopathy is effective. Homeopathy should not be used to treat health conditions that are chronic, serious, or could become serious.”
Read more at Discovery News
“We have calculated that the ice in the glaciers is equivalent to over 150 billion cubic meters of ice — that much ice could cover the entire surface of Mars with 1.1 meters (3.6 feet) of ice,” Nanna Bjørnholt Karlsson, a post-doctoral researcher the Niels Bohr Institute at the University of Copenhagen, said in a statement.
Radar images previously revealed thousands of buried glacier-like formations in the planet’s northern and southern hemispheres.
That data has now been incorporated into computer models of ice flow to determine the glaciers’ size and hence how much water they contain.
“We have looked at radar measurements spanning 10 years back in time to see how thick the ice is and how it behaves. A glacier is, after all, a big chunk of ice and it flows and gets a form that tells us something about how soft it is. We then compared this with how glaciers on Earth behave and from that we have been able to make models for the ice flow,” she said.
The glaciers are located in belts around Mars between 30 degrees and 50 degrees latitude, roughly equivalent to just south of Denmark’s location on Earth. The glaciers are found on both the northern and southern hemispheres.
The finding could be an important clue to what happened to Mars’ water. The planet, which is now a cold, dry desert, once had oceans, lakes and habitats suitable for microbial life, results from past and ongoing science missions show.
Read more at Discovery News
“We already knew that these disks are rich in water and simple organics. This is the first time we detect more complex organics,” astronomer Karin Oberg, with the Harvard-Smithsonian Center for Astrophysics, told Discovery News.
Using the Atacama Large Millimeter/submillimeter Array (ALMA) observatory located in Chile, Oberg and colleagues found large amounts of methyl cyanide -- a complex, carbon-based molecule -- as well as simpler hydrogen cyanide molecules in the proto-planetary disk surrounding MWC 480, a very young star roughly twice the size of the sun located about 455 light-years away.
The molecules were found about 3 billion miles to 9 billion miles from the central star, which is distant by our solar system standards, but squarely in what would be a Kuiper Belt-like, comet-forming region for the larger MWC 480.
The scientists also noted that the ratios of these organics are similar to what is found in comets in the solar system.
“It seems like the molecules needed to form the building blocks of life are common during planet formation. This is exciting news when thinking about the likelihood of life originating in other systems as well,” Oberg said.
The research, which appears in this week’s Nature, “demonstrates that proto-planetary disks are active engines of chemical synthesis, and that such environments are vital for building chemical complexity long before a planetary surface is created,” astronomers Geoffrey Blake, with the California Institute of Technology, and Edwin Bergin, with the University of Michigan, write in a related commentary that also appears in Nature.
“The potentially prebiotic chemistry traced by asteroids and comets in the solar system is therefore replicated, at least in part, in other young planetary systems -- suggesting that planets are supplied with these life-bearing elements as they are born,” Blake and Bergin write.
Read more at Discovery News
The finding, reported in this week’s Nature, helps resolve a long-standing puzzle about why Earth and the moon are nearly twins in terms of composition. Computer models show that most of the material that formed the moon would have come from the shattered impactor, a planetary body referred to as Theia, which should have a slightly different isotopic makeup than Earth.
“For some 30 years this contradiction was a major challenge to physicists grappling with the formation of the moon. The hope was that better simulations might resolve this issues, but it turned out that the progress with simulations gave essentially the same results, giving rise to the ‘isotope crisis,’ as this problem came to be called,” astronomer Alessandra Matrobuono-Batisti, with the Israel Institute of Technology in Haifa, wrote in email to Discovery News.
Using advanced computer modeling, Matrobuono-Batisti and colleagues ran dozens of simulations of later-stage planet formation, each time starting with 85- to 90 planetary embryos and 1,000 to 2,000 planetesimals extending from about halfway between the orbits of Mercury and Venus to within 50 million miles or so of Jupiter’s orbit.
Within 100 million to 200 million years, each simulation typically produced three to four rocky planets as a result of colliding embryos and planetesimals, the scientists found. Looking particularly at the last moon-forming impact scenarios, the scientists assessed the likelihood that Theia and Earth had the same chemical composition.
“It turned out it is not a rare event … On average, impactors are more similar to the planets they impact compared with different planets in the same system,” Matrobuono-Batisti said.
“Our study was the first to reconsider this issue, now exploring it with large data and … wide range of models. One should always be careful when basing the assumptions on limited data,” she added.
Related papers, also published in Nature, home in on slight variations in an isotope of tungsten found on Earth and on the moon, which continue to raise questions about the moon’s formation.
“It is very unlikely -- but not impossible -- that two very different sized bodies developed the exact same tungsten isotopic composition,” University of Maryland astronomer Richard Walker told Discovery News.
“I think all three papers work to explain the formation of the moon within the framework of a giant impact. I don't think we have a better alternative at this time,” he added.
Read more at Discovery News
Apr 7, 2015
Nestled between Israel and the Palestinian territories to the west, and Jordan to the east, the Dead Sea is famous for is extreme salinity (34 percent salt, almost 10 times as salty as the ocean), and for having the lowest elevation on Earth, at 1,407 feet (429 meters) below sea level.
But for the past few decades, the sea has been shrinking rapidly, due to the diversion of water from the Jordan River (which feeds the Dead Sea) and mineral mining from its waters in the south. The water's surface is currently receding by about 3 feet (1 m) per year, according to Hanan Ginat, a geologist and academic chairman of the Dead Sea and Arava Research Center, in Israel.
As the briny water recedes, fresh groundwater wells up and dissolves layers of salt, creating large underground cavities, above which sinkholes form. The holes can open up without warning, Ginat told Live Science. "We're looking for systems to forecast where they will happen, but it's very complicated," he added.
The main reason for the Dead Sea's decline is diversion of water from the Jordan River, which used to provide about 450 billion gallons (1.7 billion cubic meters), but now only provides about 20 percent of that, Ginat said. A factory called Dead Sea Works, which pumps out seawater to harvest its salts and minerals, plays a role in the problem, he said.
Ginat's colleague at Dead Sea and Arava Research Center, geologist Eli Raz, has studied the sinkhole problem in depth. Raz found that many of the craters developed along seismic fault lines in the Jordan Rift Valley. Inside these faults, the dissolved salts are less stable and more susceptible to invading freshwater, which hollows out the gaping holes, Raz's studies suggest.
The sinkholes were first noticed in the 1970s, but have been forming more rapidly in recent years. The holes are dangerous for people who visit or live in the area, and while no one has been killed, the problem should be taken seriously, researchers warn. The sinkholes can reach up to 82 feet (25 m) deep and 131 feet (40 m) in diameter, and nearby holes sometimes join to form giant ones, according to Raz and his colleagues. More than 4,000 sinkholes exist today, mostly on the sea's western shores, Ginat said.
However, there may be a way to stave off the Dead Sea's decline. Authorities have proposed a canal that would run from the Red Sea to the Dead Sea, called the Red Sea-Dead Sea Conduit, which, in addition to providing water to Jordan, Israel and the Palestinian territories, would bring salt water to the Dead Sea and generate electricity to supply its own energy. Israel and Jordan approved the first stage of the project last month, Ginat said.
Read more at Discovery News
The reclassification, addressed in a study appearing in the latest issue of the journal PeerJ, appears to resolve a long-standing debate over what to do with Brontosaurus, which looked a lot like the dinosaur Apatosaurus.
That similarity had caused paleontologists to rename Brontosaurus as Apatosaurus excelsus. In short, it was just considered to have been another type of Apatosaurus. Gone was the cool name Brontosaurus, which means "thunder lizard" in Greek.
But now Brontosaurus is back!
In the new study, previously unearthed remains of dinosaurs similar to Apatosaurus and Brontosaurus made it possible to undertake a detailed re-investigation of how different the various dinos really were.
Study co-author Roger Benson, from the University of Oxford, and his colleagues used statistical approaches to calculate the differences between other species and genera of diplodocid dinosaurs. (This family of plant-eating dinos included some of the longest creatures ever to walk the earth. Diplodocus and Supersaurus, for example, are both thought to have grown to more than 111 feet long.)
"The differences we found between Brontosaurus and Apatosaurus were at least as numerous as the ones between other closely related genera, and much more than what you normally find between species," Benson explained in a press release.
"It’s the classic example of how science works," said study co-author Octávio Mateus. "Especially when hypotheses are based on fragmentary fossils, it is possible for new finds to overthrow years of research."
Brontosaurus has also undergone a minor image makeover as a result of the study. Because of its evolutionary history, the researchers believe the dinosaur probably had a head similar to that of Diplodocus. The image above shows what the "new" Brontosaurus looks like.
From Discovery News
Scientists studied the heart and brain activity of rats in the moments before the animals died from lack of oxygen and found that the animals’ brains sent a flurry of signals to the heart that caused irrevocable damage to the organ, and in fact caused its demise. When the researchers blocked these signals, the heart survived for longer.
If a similar process occurs in humans, then it might be possible to help people survive after their hearts stop by cutting off this storm of signals from the brain, according to the study published in the journal Proceedings of the National Academy of Sciences.
“People naturally focus on the heart, thinking that if you save the heart, you’ll save the brain,” said study co-author Jimo Borjigin, a neuroscientist at the University of Michigan Medical School in Ann Arbor.
But her team found something surprising. “You have to sever [the chemical communication between] the brain and heart in order to save the heart,” Borjigin told Live Science, adding that the finding is “contrary to almost all emergency medical practice.”
Every year, more than 400,000 Americans experience cardiac arrest, which is when the heart stops beating. Even with medical treatment, only about 10 percent survive and are discharged from the hospital, according to the American Heart Association.
The researchers addressed the question of why the heart of a previously healthy person suddenly stops functioning completely, after only a few minutes without oxygen.
It turns out that even when a person in cardiac arrest loses consciousness and shows no signs of life, the brain continues to be active. In a previous study published in PNAS in 2013, Borjigin and her colleagues found that as the heart is dying, it gets flooded with signals from the brain, probably in a desperate attempt to save the heart.
This barrage of signals may be responsible for the near-death experiences some people report, Borjigin said.
In the new study, the researchers induced cardiac arrest in rats by having them breathe carbon dioxide or by subjecting them to lethal injection. The researchers then studied the animals' brain activity using electroencephalography (EEG) and their heart activity using echocardiography (ECG) in the moments leading up to death. The team also measured the signaling chemicals present in the rats' hearts and brains throughout the experiment.
Initially, the animals' heart rates dropped off steeply. But then, their brain activity became strongly synchronized with the heart activity. The researchers used a new technology they developed for measuring heart rate, beat by beat.
While the heart and brain were in sync, the researchers observed a flood of more than a dozen neurochemicals, such as dopamine, which produces feelings of pleasure, and norepinephrine, which causes feelings of alertness. This flood of chemicals could explain why people who undergo near-death experiences describe them as "realer than real," Borjigin noted.
In the rats, the brain and heart activity remained synchronized until the heart went into a state called ventricular fibrillation, in which the lower chambers of the heart quiver instead of contracting properly, preventing the heart from pumping blood.
But when the researchers blocked the flow of these chemicals from the brain to the heart, by severing the rats' spinal cords before killing them, it delayed ventricular fibrillation. As a result, the animals survived for three times as long as the rats whose heart-brain connection was left intact.
Read more at Discovery News
Located in Chile’s Atacama Desert, the Atacama Large Millimeter/submillimeter Array (ALMA) has recently gone online and astronomers are beginning to realize its powerful potential.
As part of the ALMA Long Baseline Campaign that was carried out at the end of 2014 when the observatory’s antennae were at their widest separation of 15 kilometers (9.3 miles), this ancient galaxy was spotted. Warped by a massive foreground galaxy, the light from the ancient galaxy called SDP.81 (that was forming when the universe was 15 percent the age it is now) has been bent around the warped spacetime.
Made famous in Hubble observations, gravitational lenses are fairly common, where distant sources of light become warped around massive objects such as galactic clusters. Bright arcs are often seen and, if the configuration is just right, these arcs turn into circles creating stunning Einstein rings, as this ALMA example shows.
Most recently, Hubble’s powerful optics have been supplemented by these natural lenses, helping us see even further into the cosmos — a survey project called “Frontier Fields.” In many cases, the arcs of distant galactic light have been de-warped and pieced back together so we can gain a unique look at galaxies that would otherwise be out of view from even the most powerful space telescope.
But this near-perfect ring wasn’t captured by Hubble, ALMA has boosted the resolution of this ring, revealing never-before seen detail in this young star-forming galaxy.
The beauty of long-baseline interferometers (such as ALMA) is that individual antennae can be spaced far apart, simulating a collecting area of that baseline distance. In other words, ALMA is simulating a collecting dish 15 kilometers wide, boosting our observational potential, overshadowing the biggest space-based telescope mirror.
Read more at Discovery News
Apr 6, 2015
The reptile came by its fictionally famous nickname thanks to its lengthy schnoz, whose exact purpose continues to puzzle researchers and only occurs in males of the species.
Previous researchers of the creature have speculated that the long nose might serve as a weapon of some kind when males interacted with each other. But a research team led by Ignacio Moore, an associate professor of biological sciences at Virginia Tech, says the nose appears to be used for social interactions between males and between males and females.
The pinocchio lizard, once thought extinct for half of a century, until it was rediscovered in Ecuador in 2005, is found only in the cloud forests of Ecuador, making its living atop tall trees.
Moore, Omar Torres-Carvajal, a faculty member at the Pontificia Universidad Católica del Ecuador in Quito, and Torres-Carvajal's undergraduate student Diego Quirola, climbed up into the lizards' world and captured a few dozen individuals for study.
The lizards were housed in outdoor facilities designed to make them feel right at home, and from there the researchers dialed in on their subjects (which, they note, were returned to their exact forest homes within a few days).
The nose, in their observations, turned out to be a non-violent appendage after all.
"We were able to observe and videotape 11 copulations and two male-male combat scenarios," said Quirola in a statement. "The nasal appendage was not used as a weapon in these interactions but was used as part of the social displays. The appendage is lifted during the social interactions although what role this specific movement plays is unclear."
The researchers say they want to learn more about the evolution of the lizard's distinctive feature. They note that it is found in just two other species among the almost-400 that comprise the anoles.
"Do males with larger appendages dominate those with smaller ones? Do females prefer males with larger appendages? Did the appendix evolve under sexual selection? We hope to get some answers," said Torres-Carvajal.
Read more at Discovery News
The woodlizards, which really do look like tiny dragons, are described in the latest issue of the journal ZooKeys.
"That more than half of the diversity of a group of large, dragon-looking reptiles from South America has been discovered in recent years should be heard by people in charge of conservation and funding agencies," lead author Omar Torres-Carvajal of Ecuador’s Museo de Zoologia said in a press release.
The discoveries increase the known number of woodlizards to 15.
He and colleagues Pablo Venegas and Kevin de Queiroz explained that the reptiles are active during the day and live in lowland tropical rainforests, such as the Chocó and western Amazon basin, as well as cloudforests on both sides of the Andes.
Although the finds were made in a region known as the "Tropical Andes hotspot," cloudforests are known less for heat than for their near-persistent low-level cloud cover. They typically are located at altitudes between 3000 and 8000 feet, and are characterized by wet tropical mountain forests.
DNA analysis proved that the newly found lizards represent new species.
Could ancient people have noticed the lizards and been inspired to create dragon myths about them? It's possible.
At least three indigenous cultures from South America created stories about dragons. Folklore from Patagonia, the Jivaro of Ecuador's Amazon region and certain other cultures referred to dragon-like animals. Dragon myths, however, seem to be a worldwide phenomenon. Countries like China and India also have popular dragon myths.
Indonesia, in particular, has its Komodo dragon lizards. With some imagination, these huge carnivorous lizards do sort of look like they are spitting fire when they forcefully stick out their long tongues. The mouths of Komodo dragons may also contain venom-like proteins that can cause intense pain in victims.
The "dwarf dragons" -- some of which measure just under 5 inches in length -- aren't nearly as threatening. There could be a lot more of them, though.
Read more at Discovery News
According to the UK’s National Risk Register of Civil Emergencies: “The numbers of infections complicated by AMR (antimicrobial resistance) are expected to increase markedly over the next 20 years.
“If a widespread outbreak were to occur, we could expect around 200,000 people to be affected by a bacterial blood infection that could not be treated effectively with existing drugs, and around 80,000 of these people might die.”
To put that in perspective, the report is saying that 40 percent of people infected with an antibiotic-resistant strain of bacteria could die from their infection.
The report also said that as antibiotics become less effective, routine surgeries could carry much higher risks for infection and death.
In a sort of return to the dark ages, the report predicted that “Much of modern medicine (for example, organ transplantation, bowel surgery and some cancer treatments) may become unsafe due to the risk of infection. In addition, influenza pandemics would become more serious without effective treatments.”
All might not be lost: international groups, including the UN and World Health Organization, are working together to develop strategies to create new antibiotic strains that common bacteria aren’t immune to.
“By the summer of 2016, the review will recommend a set of actions to be agreed on at an international level in order to deal with the challenge of AMR,” the report said.
From Discovery News
The new images — taken by NASA's MESSENGER spacecraft — show that Mercury has strange features known as "hollows" (irregularly shaped, flat-floored depressions) that are only a few tens of meters deep and no more than a kilometer in diameter, scientists with the mission said. That finding suggests that Mercury may have lost some of its lighter elements, such as sodium and potassium —a phenomenon that may still be happening today, the scientists said.
"MESSENGER revealed many surprising things about Mercury," said MESSENGER participating scientist David Blewett, of the Johns Hopkins Applied Physics Laboratory. Blewett was part of the team that investigated the unusual features on Mercury as part of the low-altitude campaign, which makes up the last six weeks of MESSENGER's orbit around the planet. These and other findings from the campaign were presented at the 46th Lunar and Planetary Science Conference in Texas on March 16.
"Hollows are one of the surprises in terms of the geological processes that shape the surface at small scales," Blewett told Space.com via email.
'A crisp, fresh appearance'
When NASA's Mariner 10 flew by Mercury three times in the mid-1970s, it spotted what Blewett described as "certain odd, bright patches" within the impact craters. The patches showed up again during MESSENGER's flybys of the planet. It wasn't until 2011, when MESSENGER entered orbit and began to capture higher-resolution images, that the bright areas were revealed as shallow, irregularly shaped depressions on the surface.
Hollows are relatively small landforms — shallow features on the surface that stretch at most 0.6 miles (1 kilometer). This small size implies a relatively young age, as cratering would have eroded them away over time. The hollows do not contain many, if any, impacts within them — another characteristic that suggests that they are fairly young. Finally, the hollows' sharp edges also likely indicate these features were made relatively recently.
"The hollows are remarkable because they have a crisp, fresh appearance," Blewett said. "They are probably younger than a few tens of millions of years, but some hollows are probably forming today. It is amazing to find ongoing geological activity modifying the surface of Mercury."
While Earth's moon lacks similar features, the southern polar cap of Mars and some of the icy satellites in the outer solar system have shapes that resemble the hollows. Water ices on the Red Planet and distant moons mix with nonice material such as dirt and rock. When the sun heats these regions, the ice sublimates — meaning it changes directly from a solid to a gas. Voids grow within the features, and the remaining dirt/rock mixture collapses, creating pits.
Unlike Mars and the outer moons, the bulk of Mercury's surface lacks ice. But that doesn't mean the process is completely invalid.
"It appears that there is something in the rocks that can't stand up to the punishing environment on Mercury's surface and, as a result, is lost in a sublimationlike process," Blewett said.
Not only does Mercury suffer blistering temperatures as high as 801 degrees Fahrenheit (427 degrees Celsius), but it's also bombarded with energetic ions carried from the sun by the solar wind — in fact, more per unit area than any other planet. The weak magnetic field offers scant protection, which, in turn, often accelerates charged particles to even higher temperatures before slamming them into the surface. Finally, Mercury's proximity to the sun means it gets hit by more micrometeorites, which often travel at higher speeds than those that hit Earth's moon. All of these factors create grueling conditions on the planet.
In addition to revealing the pitting on Mercury, MESSENGER (short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging) provides clues to the identity of the elements involved in their formation. Instruments on the spacecraft reveal that Mercury has more volatiles — elements with low boiling points than expected — such as potassium, chlorine and sulfur. Their presence surprised scientists, who, before MESSENGER's arrival, thought these elements would be rare on the rocky planet.
"Based on the abundances that were measured, it seems likely that it is a sulfur compound that is being destroyed and lost to space in the locations where hollows are forming," Blewett said.
The incredible shrinking planet
Following its 2004 launch, MESSENGER became the first spacecraft to enter orbit around Mercury — a feat it accomplished in 2011. On its second extended mission, it slowly maneuvered closer to the planet; in January 2015, its orbit was only 9.3 miles (14.9 km) above the surface. As the mission heads toward its April 2015 conclusion, the close approach allows for more detailed measurements of Mercury's features.
In addition to the hollows, the MESSENGER team identified several features known as "scarps" that are smaller than those previously spotted.
As Mercury's core cools, the planet's crust contracts, leading Blewett to call it "the amazing shrinking planet." Over the past few billion years, he said, the diameter of the planet has decreased by several kilometers. As a result of the contraction, one section of crust is thrust up and over the block nearby, thus creating the long cliffs known as scarps.
Most of the scarps identified over the course of MESSENGER's mission are hundreds of kilometers long. But high-resolution images from the low-altitude campaign reveal several smaller scarps more than an order of magnitude smaller than those previously spotted. Blewett said these smaller scarps are likely very young, and may even be forming today.
The campaign also took close-up images of the only water ice known to exist on Mercury: frozen puddles found in permanently shadowed regions near the planet's poles. Like the hollows, the ice has well-defined edges and few traces of small, young impact craters, indicating their youth.
According to MESSENGER Principal Investigator Sean Solomon, of Columbia University in New York, the water stored in the polar ice deposits was most likely carried to Mercury by impacts of comets and volatile-rich asteroids, similarly to how water is thought to have arrived on Earth.
"Mercury's polar regions thus serve as a witness plate to the delivery to the inner solar system of water and organic compounds from the outer solar system — a process that, much earlier, may have led to prebiotic chemical synthesis and the origin of life on Earth," Solomon told Space.com by email.
Finally, the close orbit allowed for a detailed mapping of the planet with the spacecraft's X-ray Spectrometer, which determined the abundances of key rock-forming elements and allowed the surface elemental composition of Mercury to be mapped in detail.
End of the line
In April 2015, the mission will end with a fiery bang as MESSENGER is deliberately crashed into the surface of Mercury. Over the course of its lifetime, the spacecraft has changed the way humans view the planet closest to the sun.
"MESSENGER has been a fantastic mission that has given humans our first global look at one of Earth's closest relatives," Blewett said. "Mercury turned out to be stranger than anyone would have guessed. It looks roughly like the moon, but MESSENGER has shown that Mercury is vastly different from the moon in just about every way."
By changing the way scientists see Mercury, MESSENGER has affected theories about how the solar system formed.
As the mission concludes, the MESSENGER team will work together for another year, reviewing the newest measurements, as well as older measurements, and archiving the final data sets. In addition to collaborating on scientific paperwork describing the new findings, they will team up on a book summarizing the new knowledge of the innermost planet, Solomon said.
"I am very lucky to have been part of the MESSENGER science team since before the first Mercury flyby," Blewett said. "I was among the first humans to see the stark beauty of what was once 'Mercury incognito.' I have been working with a super team of scientists and engineers, and made good friends. It will be sad when the radio tracking tells us that the spacecraft made its final orbit, knowing that a tiny new impact crater has appeared on the surface."
Read more at Discovery News
Apr 5, 2015
The study, published in Global Change Biology, demonstrates that the mechanisms involved in restoring offspring sex ratios across generations are switched on during early development of the parents and do not simply occur as a result of adults being exposed to higher temperatures.
"Understanding the ability of species to respond and cope with rising environmental temperature is key to predicting the biological consequences of global warming," said lead author and UTS Chancellor's Postdoctoral Research Fellow Dr Jennifer Donelson.
The ability to compensate for the sex bias caused by rising temperatures is an important trait that could help constrain the impacts of ocean warming on reef fish populations and other species. However the research also suggests that when developmental temperature is too hot there is a limit to this "transgenerational plasticity."
"The research findings are significant because global warming poses a threat to species with temperature-dependent sex determination (TSD), such as reptiles and fish, potentially skewing the sex-ratio of offspring and, consequently, breeding individuals in a population," Dr Donelson said.
"It's well known that gender bias away from the optimal sex ratio of juveniles, that is roughly equal numbers of males and females, can have significant consequences for population success.
"A reduction in the proportion of females in the population could be especially damaging because population growth rate is often constrained by female fertility."
The researchers showed that even relatively small increases in developmental temperatures, just 1.5 degrees Celsius above average summer temperatures, can reduce the proportion of female offspring by more than 30 per cent. However the female sex ratio of offspring was restored when parental fish were reared at this temperature for their entire life and for two generations.
"However, only partial improvement in the sex ratio occurred at 3.0 degrees Celsius above average conditions, even after two generations, suggesting a limitation to transgenerational plasticity when the developmental temperature is too hot," Dr Donelson said.
"Previous research has focused on the changes to the timing of breeding and mothers behaviourally altering the location of their nest to compensate for warming. The novelty of our study was using a multigenerational (three generations) rearing design to ask questions about non-genetic and non-behavioural parental effects to sex determination," Dr Donelson added.
Read more at Science Daily
As part of the recommissioning process, engineers at the Large Hadron Collider (LHC) successfully introduced two proton beams, the source material for sub-atomic smashups.
All systems would be checked over coming days before the energy of the beams was increased, CERN said in a statement.
"After two years of intense maintenance and several months of preparation for restart, the Large Hadron Collider, the most powerful particle accelerator in the world, is back in operation," CERN said.
"Today (Sunday) at 10:42 am (0842 GMT) a proton beam was back in the 27-kilometre (17-mile) ring, followed at 12:27 pm by a second beam rotating in the opposite direction," it added.
CERN director for accelerators and technology described the LHC as "in great shape".
"But the most important step is still to come when we increase the energy of the beams to new record levels," he said.
A short-circuit in one of the LHC's magnet circuits eight days ago had delayed the eagerly-awaited restart.
The LHC comprises a ring-shaped tunnel straddling the Franco-Swiss border, in which two beams of protons are sent in opposite directions.
Powerful magnets bend the beams so that they collide at points around the track where four laboratories have batteries of sensors to monitor the smashups.
The sub-atomic rubble is then scrutinised for novel particles and the forces that hold them together.
In 2012, the LHC discovered the Higgs Boson, the particle that confers mass, earning the Nobel prize for two of the scientists who, back in 1964, had theorised its existence.
The upgrade was intended to beef up its maximum collision capacity from eight teraelectronvolts (TeV) to 14 TeV -- seven TeV for each of the two counter-rotating beams.
Read more at Discovery News