Jeff Benca is an admitted über-geek when it comes to prehistoric plants, so it was no surprise that, when he submitted a paper describing a new species of long-extinct lycopod for publication, he ditched the standard line drawing and insisted on a detailed and beautifully rendered color reconstruction of the plant. This piece earned the cover of March's centennial issue of the American Journal of Botany.
Benca described this 400-million-year-old fossil lycopod, Leclercqia scolopendra, and created a life-like computer rendering. The stem of the lycopod is about 2.5 millimeters across.
"Typically, when you see pictures of early land plants, they're not that sexy: there is a green forking stick and that's about it. We don't have many thorough reconstructions," said Benca, a graduate student in the Department of Integrative Biology and Museum of Paleontology at UC Berkeley. "I wanted to give an impression of what they may have really looked like. There are great color reconstructions of dinosaurs, so why not a plant?"
Benca's realistic, full-color image could be a life portrait, except for the fact that it was drawn from a plant that lay flattened and compressed into rock for more than 375 million years.
Called Leclercqia scolopendra, or centipede clubmoss, the plant lived during the "age of fishes," the Devonian Period. At that time, lycopods -- the group Leclercqia belonged to -- were one of few plant lineages with leaves. Leclercqia shoots were about a quarter-inch in diameter and probably formed prickly, scrambling, ground-covering mats. The function of Leclercqia's hook-like leaf tips is unclear, Benca said, but they may have been used to clamber over larger plants. Today, lycopods are represented by a group of inconspicuous plants called club mosses, quillworts and spikemosses.
Both living and extinct lycopods have fascinated Benca since high school. When he came to UC Berkeley last year from the University of Washington, he brought a truckload of some 70 different species, now part of collections at the UC Botanical Garden.
Now working in the paleobotany lab of Cindy Looy, Berkeley assistant professor of integrative biology, Benca continues to establish a growing list of living lycopod species, several of which will eventually be incorporated into the UC and Jepson Herbaria collections. Visualizing plant evolution
Benca and colleagues wrote their paper primarily to demonstrate a new technique that is helping paleobotanists interpret early land plant fossils with greater confidence. Since living clubmosses share many traits with early lycopods, the research team was able to test their methods using living relatives Benca was growing in greenhouses.
Early land plant fossils are not easy to come by, but they can be abundant in places where rocks from the Devonian Period form outcrops. But a large portion of these are just stem fragments with few diagnostic features to distinguish them, Benca said.
Physicists in Syracuse University's College of Arts and Sciences have helped confirm the existence of exotic hadrons -- a type of matter that cannot be classified within the traditional quark model.
Their finding is the subject of a forthcoming article, prepared by the Large Hadron Collider beauty (LHCb) Collaboration at CERN in Geneva, Switzerland. (LHCb is a multinational experiment, designed to identify new forces and particles in the universe.) Tomasz Skwarnicki, professor of physics, is one of the paper's lead authors.
"We've confirmed the unambiguous observation of a very exotic state -- something that looks like a particle composed of two quarks and two anti-quarks," says Skwarnicki, a specialist in experimental high-energy physics. "The discovery certainly doesn't fit the traditional quark model. It may give us a new way of looking at strong-interaction physics."
Quarks are hard, point-like objects found within the nucleus of an atom. When quarks combine in threes, they form compound particles known as baryons. Protons are probably the best-known baryons.
Sometimes, quarks interact with corresponding anti-particles (i.e., anti-quarks), which have the same mass but opposite charges. When this happens, they form mesons. These compounds often turn up in the decay of heavy human-made particles, such as those in particle accelerators, nuclear reactors, and cosmic rays.
Mesons, baryons, and other kinds of particles that take part in strong interactions are called hadrons.
This classification remained virtually unchallenged until 2007, when an international team of 400 physicists and engineers known as the Belle Collaboration discovered an exotic particle called Z(4430), which appeared to have two quarks and two anti-quarks.
"Some experts argued that Belle's initial analysis was naïve and prone to arrive at an unjustified conclusion," says Skwarnicki, adding that other exotic states have since been observed. "As a result, many physicists concluded that there was no good evidence to prove this particle was real."
A few years later, another multinational team, known as BaBar, used a more sophisticated analysis technique, only to end up provoking more controversy over the existence of Z(4430). "BaBar didn't prove that Belle's measurements and data interpretations were wrong," Skwarnicki says. "They just felt that, based on their data, there was no need to postulate existence of this particle."
Belle responded with an even more rigorous analysis of the same data set. This time, they found statistically significant evidence for Z(4430), despite the complexity of the analysis and a large number of assumptions made about the particle's production environment.
LHCb, which, for much of the past year, has closely studied its own particle data, used Belle's and BaBar's analysis techniques. In the process, Skwarnicki and his team confirmed that Z(4430) was for real -- and an exotic hadron, to boot.
"This experiment is the clincher, showing that particles made up of two quarks and two anti-quarks actually exist," Skwarnicki says. "There used to be less-clear evidence for the existence of such a particle, with one experiment being questioned by another. Now we know this is an observed structure, instead of some reflection or special feature of the data."
Professor Sheldon Stone leads a team of SU researchers at CERN (also known as the European Organization for Nuclear Research) in Geneva.
"We analyzed tens of thousands of meson decays, selected from trillions of collisions in the Large Hadron Collider [the world's largest, most powerful particle accelerator] at CERN," he says. "Because the data sample was so large, it forced us to use statistically powerful analysis that could, in turn, measure properties in an unambiguous manner. It's great to finally prove the existence of something that we had long thought was out there."
Scientists at the University of Basel report first ever successful nose reconstruction surgery using cartilage grown in the laboratory. Cartilage cells were extracted from the patient's nasal septum, multiplied and expanded onto a collagen membrane. The so-called engineered cartilage was then shaped according to the defect and implanted. The results will be published in the current edition of the academic journal The Lancet.
A research team from the University of Basel in Switzerland has reported that nasal reconstruction using engineered cartilage is possible. They used a method called tissue engineering where cartilage is grown from patients' own cells. This new technique was applied on five patients, aged 76 to 88 years, with severe defects on their nose after skin cancer surgery. One year after the reconstruction, all five patients were satisfied with their ability to breathe as well as with the cosmetic appearance of their nose. None of them reported any side effects.
Cells from the nasal septum
The type of non-melanoma skin cancer investigated in this study is most common on the nose, specifically the alar wing of the nose, because of its cumulative exposure to sunlight. To remove the tumor completely, surgeons often have to cut away parts of cartilage as well. Usually, grafts for reconstruction are taken from the nasal septum, the ear or the ribs and used to functionally reconstruct the nose. However, this procedure is very invasive, painful and can, due to the additional surgery, lead to complications at the site of the excision.
Together with colleagues from the University Hospital, the research team from the Department of Biomedicine at the University of Basel has now developed an alternative approach using engineered cartilage tissue grown from cells of the patients' nasal septum. They extracted a small biopsy, isolated the cartilage cells (chondrocytes) and multiplied them. The expanded cells were seeded onto a collagen membrane and cultured for two additional weeks, generating cartilage 40 times the size of the original biopsy. The engineered grafts were then shaped according to the defect on the nostril and implanted.
New possibilities for facial reconstruction
According to Ivan Martin, Professor for Tissue Engineering at the Department of Biomedicine at the University and University Hospital of Basel, "The engineered cartilage had clinical results comparable to the current standard surgery. This new technique could help the body to accept the new tissue better and to improve the stability and functionality of the nostril. Our success is based on the long-standing, effective integration in Basel between our experimental group at the Department of Biomedicine and the surgical disciplines at the University Hospital. The method opens the way to using engineered cartilage for more challenging reconstructions in facial surgery such as the complete nose, eyelid or ear."
Vaginal organs implanted in four girls are successfully functioning up to eight years later, researchers reported in the Lancet today.
Four teenage girls, who were born with Mayer-Rokitansky-Küster-Hauser syndrome, in which the vagina and uterus are either underdeveloped or missing, received vaginal organs that were engineered with their own cells.
The surgeries were done between 2005 and 2008, and all have reported normal functioning since then. Tissue biopsies and MRI scans also showed that the engineered vaginas were working similarly to native tissue, the researchers said.
“This pilot study is the first to demonstrate that vaginal organs can be constructed in the lab and used successfully in humans,” said lead researcher Dr. Anthony Atala, director of Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine. “This may represent a new option for patients who require vaginal reconstructive surgeries. In addition, this study is one more example of how regenerative medicine strategies can be applied to a variety of tissues and organs.”
Treating MRHK with the current standard procedure, reconstructive surgery or dilation of existing tissue, results in complications in as many as 75 percent of pediatric patients, the researchers said. And, the materials used for reconstruction usually lack a muscle layer.
The pilot study used muscle and cells from a biopsy of each patient’s genitals to build a scaffold in the shape of the vagina. Then the surgeons created a canal in the pelvis that they sutured the scaffold to. When scaffolding material is introduced to the body, cells start forming a permanent support structure that results in a new organ.
After further clinical experience with the procedure, the treatment could also be used on patients with vaginal cancer or injuries, the researchers said.
For the first time, astronomers may have spotted a moon circling an alien planet -- though they'll probably never know for sure exactly what they've found.
A team of scientists detected a pair of faraway objects that could be a giant Jupiter-like alien planet and a rocky exomoon flying freely through space, or a small dim star hosting a planet about 18 times more massive than Earth.
The astronomers used a technique called gravitational microlensing, watching what happens a big foreground object passes in front of a star from our perspective on Earth. The nearby body's gravitational field bends and magnifies the light from the distant star, acting like a lens.
Analyzing lensing events can reveal a great deal about the foreground object — for example, in the case of a star, whether it hosts a planet and, if so, how massive that world is compared to the star.
In the new study, the team observed one intriguing lensing event using telescopes in New Zealand and the Australian state of Tasmania. They determined that the foreground object has an orbiting companion about 0.05 percent as massive as itself.
"One possibility is for the lensing system to be a planet and its moon, which if true, would be a spectacular discovery of a totally new type of system," Wes Traub, chief scientist for NASA's Exoplanet Exploration Program office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement.
"The researchers' models point to the moon solution, but if you simply look at what scenario is more likely in nature, the star solution wins," added Traub, who was not involved in the study.
The team could solve the mystery if they knew how far away from Earth the lensing system, called MOA-2011-BLG-262, lies. If it's relatively nearby, MOA-2011-BLG-262 is probably a starless "rogue planet" and moon; a distant system would have to be as massive as a star to produce the same lensing effects, researchers said.
Unfortunately, the true identity of MOA-2011-BLG-262 will probably remain a mystery forever. Microlensing events are random encounters, so there will be no follow-up observations.
"We won't have a chance to observe the exomoon candidate again," study lead author David Bennett, of the University of Notre Dame, said in a statement. "But we can expect more unexpected finds like this."
And astronomers may be able to measure distances during future microlensing events using the principle of parallax, which describes how the position of an object appears to change when viewed from two different locations.
Before we had the luxuries of modern science, folks used to believe that every land animal had a counterpart in the sea. So in the depths there naturally must be sea cows, sea unicorns, and even sea pigs. By that logic, there must also be sea humans, and if we’re going to get specific, I’d like to nominate a sea hipster: the cuttlefish, a creature with immaculate fashion sense whose ink we’ve long used to make sepia-toned photos, which is totally retro right now.
These are far and away nature’s most adept camouflagers, capable of observing their surroundings and perfectly adjusting not only their color but also their skin texture in just 250 milliseconds (one species is so clever, in fact, that males can brilliantly imitate females for a chance to mate — it’s complicated). But this isn’t just about blending in: They can also launch truly bizarre displays of rippling colors to either intimidate rivals or hypnotize prey. Oh, also. They’re color blind. Yeah … scientists aren’t quite sure how that’s possible quite yet.
These are voracious, exceedingly clever predators of the highest order that aquariums have struggled for decades to raise in captivity, to no avail. Until now. Opening tomorrow is the Monterey Bay Aquarium’s Tentacles exhibit in California, a showcase of the most remarkable cephalopods from around the world, including the charming cuttlefish.
Their marine biologists have finally learned how to raise many cuttlefish species through their entire life cycle — from birth to successful reproduction — including the flamboyant cuttlefish, a teeny tiny wonder with poisonous flesh that “walks” along the seafloor and fires an incredible display of rippling zebra stripes, shown in the video below. If you have the means, get to the Monterey Bay Aquarium to see them in all their glory. And try the margherita pizza from the cafeteria. It ain’t half bad.
It Puts the Commotion on the Skin
I’ll get to the aquarium’s tactics in a bit (with raising cuttlefish, not making pizza), but first a profile of this astounding creature is in order. There are over 100 species of cuttlefish living in reefs all over the world, save for North America, one of the many reasons it’s such a treat to have them at the Monterey Bay Aquarium.
The cuttlefish’s most striking feature, of course, is its rapidly camouflaging skin, which is separated into three layers. The first is composed of pigmented chromatophores, some 200 per square millimeter, which open and close with tiny muscles to reveal yellow, red, and brown, or slight variations of those colors.
The second layer is made up of structural reflectors, which bounce light to give off a sort of iridescence. “They provide many colors,” said Roger Hanlon, a marine biologist at Brown University, “but especially the blues and greens, the short wavelengths or cold colors, thus complementing the chromatophores, which produce the warm, long wavelength colors. And so together those two layers give you all the colors of the rainbow.”
Finally, below this is a bottom-most layer of solid, unchanging white, which the cuttlefish can expose to produce high contrasts against the vivid colors of the chromatophores. Working in concert, these layers allow the cuttlefish to put on nature’s most dazzling light show, blowing all those flashy bioluminescent creatures of the deep out of the water, so to speak. And it’s all powered by one of the biggest brains relative to body size among invertebrates.
“One of the things that they’ve done very well is color coordination with the background, and that’s great, but how do they control that?” Hanlon asked. “Well it turns out they’re color blind. So how do they achieve color-blind camouflage? It’s one of those vexing questions that we’re still trying to figure out.”
And the cuttlefish doesn’t stop at color: It can also morph its skin with 3-D projections called papillae. “They’re like the ultimate goosebumps, I suppose, if you want a weak human analogy,” said Hanlon. “So to complete the picture of really perfect camouflage, they not only have the optical color, pattern, and contrast worked out, but they also have the three-dimensional skin texture worked out. And it’s the only animal on the planet that can control that.”
The cuttlefish can match the colors and patterns and textures of virtually any background, including, it seems, man-made ones like checkers in the video above, just in case it finds itself inside a shipwrecked freighter that was carrying board games. Incredibly, though, Hanlon has found that the cuttlefish doesn’t have hundreds of camouflage patterns ready to deploy. Instead, it’s working with just three templates, which it proceeds to customize with different hues and textures given the environment.
Eat Prey, Love
But why evolve skin that sucks up not only a huge amount of brain power, but also energy? Remember that muscles are controlling the thousands upon thousands of chromatophores.
A giant Australian cuttlefish in its Sunday best, which it wears to the Church of Marine Vegetation.
“What drives it is extreme predation pressure by the best visual systems on the planet, mainly in the form of what we call teleost — or bony — fishes,” said Hanlon. “So think of any predatory fish, game fish, everything from tuna to jacks to barracuda to groupers, all these teleost fishes that have developed a wide variety of keen visual capabilities.”
The cuttlefish evolved from an ancestor with a shell — which its relative the ancient nautilus retains to this day — finding itself soft-bodied and smack in the middle of the food chain, not an ideal place if you’re interested in, you know, survival. So eluding prey became a high-stakes game of hide-and-seek, with the best camouflagers surviving to pass along their good genes. Over countless generations (cuttlefish don’t live longer than two years, so we’re talking rapid turnover here), they evolved into the flashy, big-brained wonders we know today.
But don’t be mistaken: The cuttlefish isn’t spending its days cowering in the substrate. It’s a fearsome hunter itself, equipped with powerful peepers, whose bizarre W-shape Hanlon reckons gives the cuttlefish an advantage in looking upward.
“Remember, their eyes are where our ears are,” said Hanlon. “Their eyes are not binocular vision, except when they’re approaching a prey organism. They’ll scrunch the eyes forward so they have stereopsis to determine the distance away from the prey that is about the length of the tentacles.”
Now, cuttlefish keep these two tentacles retracted in a pocket amidst their eight other arms. When they reach striking distance, they flare out their arms, momentarily blinding themselves as they fire the tentacles at the prey. In a split second, these toothed suckers slam into the critter, and the cuttlefish reels in its quarry to the gnarly beak that is its mouth.
Using its eight arms to hold fast to, say, a fish, the cuttlefish first bites through the back of the head, paralyzing the prey. It can even chew through a crab’s shell “and inject a neurotoxin that’ll slow down the central nervous system,” said Hanlon. “They essentially paralyze the crab in less than a minute.” In this way, they can take prey their own size, holding on tight and leisurely munching away.
Cuttlefish have huge appetites, frantically fueling not only their big brains and dazzling skin, but also their rapid growth. And when you mate like a cuttlefish does, you’re going to want all the mass you can get. Or you can just cross-dress.
Something Fishy Is Going on Here
The giant Australian cuttlefish is indeed giant, growing to three feet long, though it’s not technically Australian, on account of lacking the proper citizenship papers. At the peak of the spawning season, there are as many as 11 males to every female, according to Hanlon. That’s a lot of competition. The largest males are best equipped to claim a female and easily fight off smaller challengers, but small males have a clever strategy for wooing ladies.
After several unsuccessful attempts of squirming past the big fellas, they’ll actually change their color to match that of a female. Males will also modify their fourth arms, which are larger than those of the females. “What these little guys do is they pull their fourth arms up, they retract them up and they make them look smaller like a female’s fourth arms,” said Hanlon. “And then they bulge their arms up as if they’re holding an egg.”
When females are holding an egg, you see, they’re never receptive to mating. So not only does the dominant male see a female instead of a male, he sees a female he has no chance of getting busy with. The little impostor slips by unnoticed and surreptitiously mates with the female. (This is not unlike the classic Marilyn Monroe flick Some Like It Hot, in which Tony Curtis and Jack Lemmon think that cross-dressing will bring them closer to that legendary beauty. Scientists aren’t yet sure, though, whether some cuttlefish also like it hot.)
“Then the question is, why did the female accept that sneaky little male and mate with him?” asks Hanlon. “Overall, females are very choosy and they reject 70 percent of mating attempts on them, but the little guys who morph into a female and waltz in there, they only get rejected 35 percent of the time.”
But how could the dominant male be so gullible? He’d just finished chasing the little jerk around for a half hour, and all of a sudden his foe tweaks his body a bit and boom, threat removed? For Hanlon, this could be due to the cuttlefish’s solitary nature. It doesn’t have the well-developed skills required to make such social recognition possible — at least not yet. “Maybe in another 1,000 generations that won’t work any longer,” he said, “but right now it’s fine, thank you very much.”
Cuttlefish mating happens face-to-face, with the pair entangling arms. The male reaches down with his enlarged fourth right arm and grabs sperm packets called spermatophores, which he’ll crack open on the female. The sperm then ideally make their way into two little pouches inside her, known as seminal receptacles, for her to store and access at a later time. The two separate, and she’s ready to mate with the next male.
“And the females always — every time we’ve done a study — always have different sources of sperm from different males,” says Hanlon. “So they’re playing a statistical game to diversify their portfolio, if you will, to get sperm sources from different males, hoping to get a range of fitness among those males to increase their own eggs for fertilizing and reproducing in the next generation.”
Strangely, females actually have a choice over which sperm to use after the male is long gone. How exactly she’s able to do so, scientists aren’t quite sure. “It’s called cryptic female choice, which is a delightful term,” Hanlon said. “It’s cryptic to the male, he doesn’t know what’s going on, but she’s doing some manipulation of sperm. So it’s a pretty dynamic mating system, lots of clever behaviors.”
Not Getting Cuttlefish Juiced Up on Caffeine, and Other Adventures in Aquarium Science
The cuttlefish’s strange sex life is but one of many mysteries that have vexed aquariums trying to raise these creatures in captivity. Just ask Bret Grasse, a marine biologist at the Monterey Bay Aquarium, who helped pioneer the techniques to not only raise cuttlefish with unprecedented success, but to be so successful that they’re shipping their extra specimens to aquariums around the world.
Cuttlefish eggs incubating in soda bottles is the only recorded instance
in history of a soft drink actually saving a life instead of shortening
it.
Forget about the diminutive young virtually disappearing with their exceedingly good camouflage. Forget that cuttlefish, not exactly accustomed to walls in their homes on the high seas, can sometimes slam into tank walls and fracture their cuttlebone, the thin structure of calcium carbonate that gives the creatures their buoyancy — a problem the aquarium solved, by the way, with tanks padded in plastic. You also have to somehow get a highly antisocial animal to play nice with its new roommates (I smell a sitcom).
“There are certain instances of cannibalism, and a social hierarchy develops as they grow older, too,” said Grasse, “where larger ones will start killing the smaller ones. Or based on your gender ratio, you’ll have either successful pairings with the right male to female ratio or you can have a big disaster on your hands based on that too.”
But first you have to get them to hatch. Surely one of the more inventive homebrew techniques at the aquarium is the soda bottle incubator, a device that’s orders of magnitude cheaper than commercial models.
In the wild, cuttlefish eggs require constant attention from their mother, who blows water over them to supply a steady stream of oxygen and keep algae from gaining a foothold. Instead of allowing the mother to instinctually care for her young like this, Grasse removes the eggs and drops them in an aerated soda bottle — without the soda, of course. These hyperactive critters are the last creatures on Earth you’d want going manic on caffeine.
“What that does is it takes away that maternal duty by the mother cuttlefish,” he said, “and allows her to reallocate that energy into oviposition and just basically making more eggs.” Using this technique, the aquarium went from having 35 percent of their pharaoh cuttlefish eggs actually hatch to an incredible 95 percent.
When startled by a predator — including a swatter-wielding person — tiny fruit flies respond like fighter pilots, employing screaming-fast banked turns to evade attacks, according to a new study.
The slick move was evident in the study, published in the latest issue of Science, since researchers used an array of high-speed video cameras operating at 7,500 frames a second to capture the wing and body motion of flies after they encountered a looming image of an approaching predator.
“Although they have been described as swimming through the air, tiny flies actually roll their bodies just like aircraft in a banked turn to maneuver away from impending threats,” co-author Michael Dickinson, a University of Washington professor of biology, said in a press release.
He added, “We discovered that fruit flies alter course in less than one one-hundredth of a second, 50 times faster than we blink our eyes, and which is faster than we ever imagined.”
In the midst of a banked turn, the flies can roll on their sides 90 degrees or more, almost flying upside down at times, according to co-author Florian Muijres.
“These flies normally flap their wings 200 times a second and, in almost a single wing beat, the animal can reorient its body to generate a force away from the threatening stimulus and then continues to accelerate,” Muijres explained.
The fruit flies are about the size of a sesame seed, so they are not exactly known for impressive brain size. But consider that big bodies need larger brains to control everything. A small brain simply has a smaller body to control. It doesn’t necessarily mean that the species is a dummy.
Houseflies also plot and plan clever escapes. You can see this at work in slow motion in the following video:
“The brain of the (fruit) fly performs a very sophisticated calculation, in a very short amount of time, to determine where the danger lies and exactly how to bank for the best escape, doing something different if the threat is to the side, straight ahead or behind,” Dickinson said.
An extinct marsupial hunter only the size of a fox may have hunted prey larger than itself, researchers say.
This predatory ability makes the ancient creature different from its most recent living relative, the also-extinct thylacine, or "Tasmanian tiger." The last known wild thylacine was shot in 1930, and the last captive member of the species died in a zoo in 1936.
Hunting apparently helped drive the species to extinction. People targeted the dog-like Tasmanian tigers because they believed that the animals killed sheep; in fact, a 2011 study published in the Journal of Zoology found that the creatures' jaws were too weak to take down large prey, and that they would have only killed animals smaller than themselves.
The new study analyzed an exceptionally well-preserved whole skeleton of an extinct relative of these last thylacines, known as Nimbacinus dicksoni; the specimen dates to about 11.6 million to 16 million years old.
"The discovery of an entire skeleton of Nimbacinus was a truly amazing finding, particularly as it is was in such good condition," said study author Stephen Wroe, a zoologist and paleontologist at the University of New England in Australia.
Tiny lions and carnivorous kangaroos
The marsupial carnivore was about the size of a very large housecat or a small fox, weighing about 11 pounds (5 kilograms). "Its face looked like a cross between a cat and an opossum," said study lead author Marie Attard, a zoologist at the University of New England in Australia.
The modern thylacine (Thylacinus cynocephalus)was larger, comparable in size to a medium-sized or large dog. Modern thylacines weighed in at between 40 and 70 lbs. (20 to 30 kg).
Paleontologists discovered the fossil in the mid-1990s in the Riversleigh World Heritage Area in Australia. In ancient times, warm, humid, lowland rainforests covered this region — then, about 10 million to 15 million years ago, it became progressively cooler and drier, transforming into dry open woodlands and grasslands.
Nimbacinus belonged to an extinct family of marsupial carnivores known as the thylacinids, consisting of at least 12 known species. Nimbacinus may have lived in ancient Riversleigh with several other thylacinid species, along with marsupial lions smaller than a housecat and small carnivorous kangaroos, potentially competing with them all for prey.
"As a medium-sized carnivore, Nimbacinus was likely hunted by larger meat-eaters, including snakes, ground-dwelling crocodiles and larger species of marsupial lions," Wroe told Live Science.
Aside from studies of the recently extinct thylacine, most knowledge about thylacinids comes from skull fragments, limiting what scientists could deduce about the animals. The newly unearthed Nimbacinus skull, however, helped Attard and her colleagues reconstruct how this creature may have lived.
Modeling a marsupial
The researchers created a 3D computer model of the Nimbacinus skull to realistically simulate how the skull may have behaved. Digitally reconstructing the whole skull posed a challenge, as the top of its cranium had been slightly crushed and only half of its lower jaw, or mandible, was intact. "It was like opening a jigsaw puzzle box, only to find crucial missing pieces," Attard told Live Science.
The scientists then compared the mechanical performance of the Nimbacinus skull with that of the extinct thylacine. They also compared its performance to that of living marsupial carnivores such as the Tasmanian devil, spotted-tailed quoll and northern quoll. These belong to a different and diverse family of marsupial carnivores, the dasyurids.
In a surprise, the researchers discovered the mechanical performance of the Nimbacinus skull was far more similar to the spotted-tailed quoll, a member of a different family of marsupial carnivores, than to the Nimbacinus' closer relative, the thylacine.
These findings suggest Nimbacinus had a powerful bite for its size, was mostly carnivorous and was probably capable of hunting prey larger than itself.
"Our biomechanical analysis of the skull of Nimbacinusrevealed that it was likely an opportunistic hunter of the rainforest and had a broadly similar way of life to that of larger living dasyurids such as the spotted-tailed quoll," Attard said. "It likely preyed upon small- to medium-sized birds, frogs, lizards and snakes, as well as a wide range of marsupials, including possums, bandicoots, dasyurids, ancient ancestors of koalas, small wallabies, thingodontans [extinct marsupials with boomerang-shaped molars], marsupial moles and wombats. This suggests possible convergent evolution between Nimbacinus and the spotted-tailed quoll, meaning that these two species independently evolved similar adaptations to similar environments."
In contrast, the recently extinct Tasmanian tiger was considerably more specialized in what it could eat than Nimbacinus and large living dasyurids. This likely made the Tasmanian tiger more restricted in the range of prey it could hunt, "and more vulnerable to extinction," Attard said.
The Gospel of Jesus’ Wife, a papyrus fragment of Coptic script containing a suggestion that Jesus may have been married, is an ancient document, and not a modern forgery, says a paper published in the Harvard Theological Review on Tuesday.
Tests by teams of engineering, biology, and chemistry professors from Columbia University, Harvard University, and MIT indicate the papyrus dates to between the sixth and ninth centuries, and possibly as far back as the second to fourth centuries.
The brownish-yellow, tattered fragment, about 1 1/2 inches by 3 inches, caused international uproar when it was presented at a conference in Rome in September 2012 by Harvard Professor Karen L. King.
Written in Coptic, a language of ancient Egyptian Christians, the fragment appears to be a broken conversation between Jesus and his disciples.
The center of the business-card-sized papyrus, which features just eight lines of text on the front and six lines on the back, contained the bombshell phrase “Jesus said to them, ‘My wife …’
“She will be able to be my disciple,” said the next line. And then: “I dwell with her.”
Dismissed as a “clumsy forgery” by the Vatican newspaper, the Gospel of Jesus’ Wife was widely debated by scholars. Skepticism abounded, with several experts arguing over the document’s poor grammar and its uncertain provenance.
But according to Harvard Divinity School, “none of the testing has produced any evidence that the fragment is a modern fabrication or forgery.”
“The fragment does not provide evidence that the historical Jesus was married but concerns an early Christian debate over whether women who are wives and mothers can be disciples of Jesus,” King wrote in the Harvard Theological Review.
In addition to radiocarbon testing, microscopic and multispectral imaging, the researchers used micro-Raman spectroscopy to determine that the carbon character of the ink matched samples of other papyri that date from the first to eighth centuries.
“After all the research was complete, King weighed all the evidence of the age and characteristics of the papyrus and ink, handwriting, language, and historical context to conclude the fragment is almost certainly a product of early Christians, not a modern forger,” Harvard Divinity School said in a statement.
The Harvard Theological Review is also publishing a rebuttal to King’s findings by Brown University professor Leo Depuydt, who still maintains the document is a forgery.
“And not a very good one at that,” he wrote.
According to Depuydt, the fragment contains “gross grammatical errors.” Also, each word in it matched writing in the Gospel of Thomas, an early Christian text discovered in Nag Hammadi, Egypt, in 1945.
Invasive species such as the killer shrimp, zebra mussel and American signal crayfish may be traveling from waterway to waterway throughout Britain in canoes and fishermen's waders.
A survey of 1,500 outdoor enthusiasts published in PLoS ONE shows that most aren't taking precautions to avoid transporting invasive species.
More than half of anglers and nearly 80 percent of canoeists surveyed visited more than one waterway within two weeks. If their equipment isn't properly cleaned and dried between water activities, invasive species can easily hitch a ride. Killer shrimp can survive in damp gear, even in a fold of a wetsuit, for up to 15 days, said study co-author Alison Dunn of the University of Leeds in a release.
“Once it gets into the new water system, it is voracious,” she said of the shrimp species. “It will take bites out of things and leave them uneaten, killing when it doesn't need to eat.”
Attempting to curb the spread of invasive species, the British government launched a “Check, Clean, Dry” campaign in 2011 to encourage water sports enthusiasts to examine and thoroughly dry their equipment.
Prevention is the best way to contain these destructive animals, said study lead author Lucy Anderson, also of the University of Leeds, in a release: “Once invasive species establish in rivers and lakes, they're almost impossible to eradicate.”
But Anderson and her colleagues show that many of Britain’s more than 4 million anglers and 400,000 boat owners aren't following that advice. Half of the canoeists and 12 percent of the anglers surveyed do not clean or dry their equipment between trips.
A message in a bottle tossed in the sea in Germany 101 years ago, believed to be the world's oldest, has been presented to the sender's granddaughter, a museum said.
A fisherman pulled the beer bottle with the scribbled message out of the Baltic off the northern city of Kiel last month, Holger von Neuhoff of the International Maritime Museum in the northern port city of Hamburg said.
"This is certainly the first time such an old message in a bottle was found, particularly with the bottle intact," he said.
Researchers then set to work identifying the author and managed to track down his 62-year-old granddaughter Angela Erdmann, who lives in Berlin.
"It was almost unbelievable," Erdmann told German news agency DPA.
She was first able to hold the brown bottle last week at the Hamburg museum.
Inside was a message on a postcard requesting the finder to return it to his home address in Berlin.
"That was a pretty moving moment," Erdmann said. "Tears rolled down my cheeks."
Von Neuhoff said researchers were able to determine based on the address that it was 20-year-old baker's son Richard Platz who threw the bottle in the Baltic while on a hike with a nature appreciation group in 1913.
A Berlin-based genealogical researcher then located Erdmann, who never knew Platz, her mother's father who died in 1946 at the age of 54.
Von Neuhoff said a handwriting comparison with letters penned by Platz later in life confirmed that he was "without a doubt" the author.
Erdmann told local newspapers that the surprise discovery had inspired her to look through family scrapbooks to learn more about her grandfather, a Social Democrat who liked to read.
An ancient Egyptian coffin complete with the skeleton of a man buried with a gold Pharaonic seal has been unearthed in Israel, the Israel Antiquities Authority (IAA) announced Wednesday.
Found in the Jezreel Valley in northern Israel during work to install a gas pipeline, the coffin was part of a burial site dating to the Late Bronze Age (13th century B.C.).
The 3,300-year-old cylindrical clay sarcophagus featured a rare anthropoidal lid — a cover in the shape of a person — and was surrounded by “a variety of pottery consisting mainly of storage vessels for food, tableware, cultic vessels and animal bones,” IAA excavation directors Edwin van den Brink, Dan Kirzner and Dr. Ron Be’eri, said in a statement.
Showing an impression of a man’s face in the Egyptian style, with stylized hair, ears and hands crossed over the chest, the coffin contained the skeleton of an adult male buried with a bronze dagger, a bronze drinking bowl, pottery and hammered pieces of bronze.
“Since the vessels interred with the individual were produced locally, we assume the deceased was an official of Canaanite origin who was engaged in the service of the Egyptian government,” the researchers said.
Another, less likely possibility is that the coffin belonged to a wealthy local individual who imitated Egyptian funerary customs.
Next to the skeleton, the archaeologists found an Egyptian scarab seal encased in gold and affixed to a ring which bore the name of Seti I, the Pharaoh who conquered the region in the 13th century B.C.
One of the most powerful kings of the Nineteenth Dynasty, Seti I was the father of Ramses II, identified by some scholars as the pharaoh in the biblical story of the Israelites’ exodus from Egypt.
A centuries-old Stradivarius, or a shiny new violin? Aficionados often say that older instruments sound better, but a scientific study has found that actually, expert players preferred new ones.
Soloists were also unable to tell the difference between new and old violins at any better rate than simple chance, said the study in this week's edition of the Proceedings of the National Academy of Sciences.
Ten professional violinists were asked to choose from six old and six new Italian violins, and decide which they would pick to replace their own for an upcoming tour.
The musicians were unaware which instruments were old or new, and the new ones were antiqued to give the appearance of age.
They had plenty of time to play each instrument, first in a rehearsal room and later in a concert hall.
Six chose new violins, and four chose old ones.
When researchers compared the violins by preference scores based on a top-four list compiled by each musician, new violins outscored old by a ratio of six to one.
"On average, soloists rated their favorite new violins more highly than their favorite old for playability, articulation, and projection, and at least equal to old in terms of timbre," according to the study.
"Soloists readily distinguished instruments they liked from those they did not but were unable to tell old from new at better than chance levels."
A new image from the Hubble Space Telescope reveals a galaxy cluster so huge that it acts like a magnifying glass, warping and amplifying light from galaxies much farther away.
The new Hubble telescope photo shows the galaxy cluster MACS J0454.1-0300, which is so massive it is the equivalent of about 180 trillion suns. For comparison, the sun is about 333,000 times the mass of the Earth.
In this image, released last week, the cluster magnifies galaxies that would be too faint to be detected normally with today's technology. These faraway galaxies, each containing millions or billions of stars, appear as sweeping, elongated arcs to the left of this image, NASA officials said. This magnifying process is known as gravitational lensing.
Astronomers are actively taking advantage of gravitational lensing as part of an effort known as the Frontier Fields program, which the Hubble Space Telescope will participate in.
For each Frontier Fields photo, the Hubble Space Telescope will train its gaze at a seemingly empty part of the sky and collect light for about 103 hours to peer at galaxies that lurk in the distant universe.
Give me a home among the gum trees, one to snooze in during the day, and a different one at night to eat.
That's the preference of koalas, according to a new study that examines the iconic Australian animal's behavior and feeding patterns published in the latest issue of CSIRO journal Wildlife Research.
The discovery has implications for koala conservation, says study lead author Karen Marsh of the Australian National University.
"At the moment a koala habitat is based on the trees people find koalas in during the day, but those aren't necessarily the trees they want to eat, and so we need a broader habitat definition," said Marsh.
Although koalas are a popular species for study, very little is known about their behavior and feeding patterns, especially at night.
"A lot of people have researched what trees koalas prefer from a non-feeding perspective, but there's an assumption that if you see a koala in a tree, then they probably eat it," said Marsh.
"Just by looking at koalas in trees, without taking into account how much they eat from those trees, means we're missing the larger picture of what else they use these trees for.
"We wanted to know what makes koalas interested in one type of eucalypt rather than another."
Bugging koalas
To investigate what koalas get up to day and night, Marsh and colleagues attached microphones to eight animals in a bush reserve on Victoria's Phillip Island.
They used audio and radio telemetry to track koala movements and continuously monitor their activities for 14 days, to determine their feeding patterns and social interactions.
"We recorded hundreds of hours of data," said co-author Ben Moore of the University of Western Sydney.
"We were able to determine which trees they were in at different times, and could also hear them munching on leaves. This allowed us to record the types of trees they visited, as well as when, how often and for how long they feed."
The researchers were then able to examine the trees being used by the koalas, and analyse the nutritional composition of the leaves. Koala favorites
They found the trees koalas preferred to sit in, didn't necessarily correspond to what they preferred eating.
Individual koalas varied in how many trees they visited, how many meals they ate and how long they spent feeding during each 24-hour period.
They liked to relax in blue gums (Eucalyptus globulus) during the day, but fed mainly at night, with a general preference for Manner gums (Eucalyptus viminalis).
"We don't really know how koalas choose trees, but they all seem to prefer leaves with more protein and less toxins, and spend much longer feeding in those trees," said Marsh.
"Koalas eat very different amounts from each tree they visit and that is highly dependent on the nutritional value of the leaves.
"Each tree can have very different levels of proteins and toxins compared to the tree next to it regardless of the species, which can have a big impact on how much the koalas eat."
The researchers also found koalas had a very strong preference for sitting in large trees with more shade during the day.
Oarfish, including the 36-foot-long (11 meters) giant oarfish (Regalecus glesne), normally elude human eyes in the depths of the oceans. However, a lucky group of tourists recently filmed two oarfish in the shallow, coastal waters of Baja, Mexico. The oarfish observers were kayaking as part of a cruise with the Shedd Aquarium.
Oarfish live around the globe in temperate and tropical waters, down to 3,000 feet (915 meters) below the waves. Yet, despite the fishes' wide distribution, oceanographers and other humans rarely glimpse the four known species of oarfish in the deep sea habitat they prefer.
Most encounters with oarfish occur when the animals wash up dead on the beach, or sick in the shallows. The health of the oarfish filmed on the Baja coast was unknown. Last year, a dead 18-foot oarfish was towed to shore by a snorkeler at Catalina Island off the California coast. Then a 14-foot oarfish corpse turned up north of San Diego a few days later. The bigger fish was filled with parasites, reported Live Science, while the smaller fish was filled with hundreds of thousands of eggs, reported the AP.
The giant oarfish sets the world record for largest bony fish, according to the Florida Museum of Natural History. Whale sharks and basking sharks beat them for the title of world's longest fish, though the sharks have cartilage skeletons. Oarfish maintain their scale-less, silver, ribbon-like bodies by eating tiny zooplankton and small squid, shrimp and fish. The jelly-like meat of the oarfish has little commercial value.
Myth holds that the appearance of oarfish heralds an earthquake. There may be some scientific basis for the observation of oarfish around the time of earthquakes, though nothing has been proven.
“Deep-sea fish living near the sea bottom are more sensitive to the movements of active faults than those near the surface of the sea.” Kiyoshi Wadatsumi, director of non-profit earthquake prediction research organization e-PISCO, told the Japan Times after numerous oarfish came near the Japanese coast in 2010.
An ancient Egyptian mummy found with an intact brain, but no heart, has a plaque on her abdomen that may have been intended to ritually heal her, say a team of researchers who examined the female body with CT scans.
The woman probably lived around 1,700 years ago, at a time when Egypt was under Roman rule and Christianity was spreading, according to radiocarbon dating. Her name is unknown and she died between age 30 and 50. Like many Egyptians, she had terrible dental problems and had lost many of her teeth.
The use of mummification was in decline as Roman culture and Christianity took hold in the country. But this woman and her family, apparently strong in their traditional Egyptian beliefs, insisted on having the procedure done.
To remove her organs, the scans show, the embalmers created a hole through her perineum and removed her intestines, stomach, liver and even her heart. Her brain, however, was left intact. Spices and lichen were spread over her head and abdomen, and she was wrapped and presumably put in a coffin; her final resting place was likely near Luxor, 19th century records say.
Before the embalmers were finished they filled the hole in the perineum with linen and resin. They also put two thin plaques similar to cartonnage (a plastered material) on her skin above her sternum and abdomen, something that may have been intended to ritually heal the damage the embalmers had done and act as a replacement, of sorts, for her removed heart.
"The power of current medical imaging technologies to provide evidence of change in ancient Egyptian mortuary ritual cannot be understated," writes the research team in an article to be published in the "Yearbook of Mummy Studies." While the technology is powerful it does have some limits. The presence of spices and lichen on the head were first found in the 19th century when the head was unwrapped. The CT scans revealed that they are likely also located on the mummy's abdomen, a determination aided by this unwrapping.
The mummy and its coffin — now at the Redpath Museum at McGill University in Montreal — were purchased at Luxor in the 19th century. Scientists aren't sure if the coffin she is in now was originally meant for her. Antiquity dealers in the 19th century would sometimes place a mummy into a coffin from another tomb to earn more money. Coffins were also sometimes reused in antiquity. What happened to the heart?
The heart played a central role in ancient Egyptian religion, being weighed against the feather of ma'at (an Egyptian concept that included truth and justice) to see if one was worthy of entering the afterlife. For this reason, Egyptologists had long assumed the Egyptians didn't remove that organ, something that recent research into several mummies, including this one, contradicts.
With evidence showing the heart was removed on at least some occasions Egyptologists are left with a question, what did the ancient Egyptians do with it?
"We don't really know what's happening to the hearts that are removed," said Andrew Wade, a professor at McMaster University in Hamilton, Canada, in an interview with Live Science. During some time periods, the hearts may have been put in canopic jars, a type of jar used to hold internal organs, though tissue analysis is needed to confirm this idea, Wade said.
Healing the mummy?
Even more mysterious is a question that Wade's team is currently grappling with: Why did this woman receive two plaques in areas that were never sliced open?
The plaque on the sternum may have acted as a replacement, of sorts, for the removed heart, they said. However, the one on the abdomen is more ambiguous. The team knows that mummies who were dissected through the abdomen received a plaque like this, however, scans reveal this woman's abdomen was never touched.
The embalmers may have thought the plaque would help by ritually healing the hole they had created in the woman's perineum, the researchers speculate. By doing so they may have been trying to give her "a more favorable afterlife, healed and protected as she was by the embalmer's additional efforts," the researchers write in their paper.
Most New Yorkers don't even know it exists. But a million forgotten souls are buried in mass graves dug by convicts on a tiny, forbidden island east of the Bronx.
Since 1869, still-born babies, the homeless, the poor and the unclaimed have been stacked one upon the other, three coffins deep, on Hart Island. Corpses are interned in great, anonymous trenches. There are no tombstones. Small white posts in the ground mark each 150 adult bodies. A thousand children and infants are buried together per grave.
It is one of the largest cemeteries in the United States. And the least visited.
The men doing the digging are convicts from Rikers Island, petty offenders tasked with carrying bodies to their final resting place. Nearly 1,500 fresh corpses arrive each year, says visual artist Melinda Hunt, who heads the Hart Island Project, which campaigns to make the cemetery visible and accessible. The authorities say nearly a million people have been buried here since 1869.
It is forbidden to film and photograph the uninhabited, windswept island. Visits must be authorized by the Department of Corrections, which runs the island. First used as a cemetery in the Civil War, Hart Island has variously served as a training camp, a prison for captured Confederates, a workhouse, a mental asylum and even a Cold War missile base.
The only jetty is closed to the public, hemmed in by railings, barbed wire and spikes. Notice boards warn people to keep out.
Records Long Inaccessible
For years, records of who's been buried where have been patchy and negotiating access has proved challenging. Some have been lost, others burnt. Families sometimes cannot even find out if their loved ones were buried by the city.
"You have a right to know where a person is. It's very important not to disappear people. It's not an acceptable thing to do in any culture," Hunt said.
The Department of Corrections says it doesn't have the infrastructure to welcome visitors on an island where the buildings are dilapidated and abandoned. Under pressure, however, the authorities have allowed a few visits since 2007, albeit within a gazebo far from the graves.
"You don't see anything," said Elaine Joseph, a 59-year-old nurse whose baby daughter died at five days old in 1978. "They check your ID, and ask you to hand over your cell phone, any electronic equipment and they put it in an envelope and lock it and then you get to the island, they ask for your ID again.
"They treat you as a visitor of an inmate," she said.
In November, a small group of women who threatened to bring a complaint were given permission to visit specific grave sites. Joseph became the first to go on March 14. Once there, she broke down in tears.
"I can't say I found closure. When you lose a child, there really is never closure. There is a piece of you that is gone," she said. "I did find solace in that there was water surrounding it and there was a lovely view."
She was even allowed to take a photograph.
Laurie Grant, a 61-year-old doctor who gave birth to a still-born daughter in 1993, hopes to be the next. But on March 28, she waited in vain in the rain on the jetty. Due to unwillingness or miscommunication, those who were supposed to ferry her across the water left before she even arrived.
- Public cemetery closed to public -
Over the years, Hunt said she has lost track of all the families she has tried to help, though estimates the number is at least 500. Most were Americans, but there have been others from France, the Netherlands and Poland, and one Irish woman looking for a grandfather.
The Hart Island Project has so far managed to list more than 60,000 burials in the database. A bill has been introduced to the city council seeking to transfer the island to the parks administration, but has not been taken up yet.
The fossil of an extinct marine predator that lay entombed in an ancient seafloor for 520 million years reveals the creature had a sophisticated heart and blood-vessel system similar to those of its distant modern relatives, arthropods such as lobsters and ants, researchers report today (April 7).
The cardiovascular system was discovered in the 3-inch-long (8 centimeters) fossilized marine animal species called Fuxianhuia protensa, which is an arthropod from the Chengjiang fossil site in China's Yunnan province. It is the oldest example of an arthropod heart and blood vessel system ever found.
"It's really quite extraordinary," said study co-author Nicholas Strausfeld, a neuroscientist at the University of Arizona in Tucson.
The cardiovascular network is the latest evidence that arthropods had developed a complex organ system 520 million years ago, in the Cambrian Period, the researchers said. Arthropods come in a wide range of shapes and sizes today, but the animals have kept some aspects of their basic body plan since the Cambrian. For instance, the brain in living crustaceans is very similar to that of F. protensa, which is a distant relative — but not a direct ancestor of — modern species, Strausfeld said. "The brain has not changed much over 520 million years," he said.
In contrast, blood vessel networks have become both simpler and more complex in the ensuing millennia, in response to changing bodies. The modern relatives of F. protensa are arthropods with mandible jaws, and include everything from insects such as beetles and flies to crustaceans such as shrimp and crabs.
"What we're seeing in the arterial system is the ground pattern, the basic body pattern from which all these modern variations could have arisen," Strausfeld told Live Science.
In the fossil, the creature's organs were preserved like a carbon 'copy.' Its hard exoskeleton is extremely faint, but the soft, internal organs became a dark-brown carbon imprint on fine-grained rock called mudstone.
The animal had a tube-shaped heart positioned near its back, rather than toward the front. The blood vessels extended from the heart along its body segments and clustered near the eyes and brain, which suggests these organs required a rich oxygen supply. The fossil also has eyestalks, antennae, legs and a brain, the researchers reported.
The heart and blood vessels were identified in a fossil in the collection at the Yunnan Key Laboratory for Palaeobiology in China, by an international team of researchers led by London Natural History Museum paleontologist Xiaoya Ma. The findings were published in the April 7 issue of the journal Nature Communications.
In 2012, the same team also reported the oldest example of an arthropod brain, in a different Chengjiang F. protensa fossil.
The Mexican blind cavefish does not have eyes, but it can "see" obstacles in dark caves by puckering its mouth and producing bursts of suction, according to a new study. The research describes this unique form of navigation for the first time.
Scientists previously thought the eye-less Mexican cavefish navigated by sensing changes in water pressure produced by waves sent off from the fish's own body. But when the researchers examined the fish, they found some problems with this explanation. For example, larger fish, which would presumably produce larger waves, should be able to identify objects from farther away than smaller fish. In fact, larger fish detected objects at about the same distance as smaller fish did.
Researchers at Tel Aviv University in Israel decided to investigate the sightless navigation further, conducting an experiment in which they counted the number of times the fish opened and closed their mouths when near objects the fish were familiar with. The researchers then moved the objects and observed changes in the fishes' mouth movement in the unfamiliar environment.
The fish opened and closed their mouths more than twice as frequently in unfamiliar surroundings, and more frequently when approaching an object than in the open, with no objects nearby, suggesting this behavior plays a role in detecting the fish's environment.
Through further analyses, the team determined the suction sent off by this mouth motion produces a signal similar to echolocation — a system in which animals, like bats and dolphins, emit sound waves and detect the distance of an object based on how long the sound takes to bounce back. Instead of measuring time, however, the cavefish appear to measure the magnitude of the pressure change produced by their mouth suction, study co-author Roi Holzman told Live Science.
"In this sense, it is different from echolocation, but it is similar because you have an animal that is purposefully emitting pressure waves to locate obstacles," Holzman said.
The team does not know if other fish use this form of navigation. But some likely do, since all fish have the ability to produce suction waves with their mouths, and all have receptive organs along the sides of their bodies that can detect changes in water pressure. Both adaptations can be traced far back in the evolutionary history of fish, said Holzman.
"It's a [newly discovered] mechanism made out of ancient material, and it just makes sense that other fish would have it," Holzman said. "We haven't tested it yet, but I'd really like to."
The fish may also passively gather information produced by body waves when they swim through water, as previous studies have suggested, the team speculates. But the cavefish likely use both navigation methods in tandem, similar to how submarines rely on both active and passive sonar, Holzman said.
Lava lamps are aptly named -- the mesmerizing globby wax mimics the way pockets of molten rock rise buoyantly through the Earth's crust.
The lamps wouldn't be as much fun if the wax were neutrally buoyant, neither sinking nor rising. Yet Earth's system of plate tectonics may depend on such a layer of neutrally buoyant magma that likely exists beneath Earth's continents.
Most simple models of the Earth's interior present three concentric layers: crust, mantle, and core. Geologists call the layer of rigid rocks that extends from the surface of the Earth down to the top of the mantle the lithosphere. Just below the lithosphere is a layer called the asthenosphere, a slowly-flowing, not-quite-melted layer -- think slush.
Geophysicists studying the lithosphere-asthenosphere boundary (let's just call it the LAB) noticed evidence that a thin layer of magma may separate the two layers. But some argued that because less-dense magma normally rises through rock, like blobs of wax in a lava lamp, such a layer couldn't remain stable for long.
Or could it?
A French team calculated how a melted magma would behave at the LAB if it were made of a rock called alkali basalt (similar to the basalt shown), likely present in the asthenosphere. At the pressures and temperatures expected at the LAB beneath continents, alkali basalt melts but doesn’t sink into the asthenosphere or rise into the lithosphere -- it's neutrally buoyant and could remain stable at the LAB, the team writes in Earth and Planetary Science Letters, which published their results.
If you’ve ever gambled, you may have noticed that a near-miss makes you want to keep playing.
It’s just one example of the misconceptions of winning people often make in casinos. Another: if black is rolled five times in a row, red must be “due” — right? Wrong.
Now, researchers think they have identified the mechanism in the brain that leads problem gamblers to make such cognitive distortions more than others.
They found that people whose insula – an area of the brain that plays a key role in emotions — was damaged didn’t get tempted to continue playing after near-misses or a string of red or black luck. All other groups of participants — including patients with injuries to other parts of the brain as well as healthy participants — did.
“Based on these results, we believe that the insula could be hyperactive in problem gamblers, making them more susceptible to these errors of thinking,” said Dr. Luke Clark of the University of Cambridge, lead researcher of the study published today in PNAS. “Future treatments for gambling addiction could seek to reduce this hyperactivity, either by drugs or by psychological techniques like mindfulness therapies.”
To prepare humanity’s most complex machine for its next round of awesome physics, it’s not simply a question of flicking the ‘on’ switch.
The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland, has begun its long restart process after being powered down in February 2013 for repairs and upgrades. The whole startup process isn’t expected to be complete until early 2015.
“The accelerator complex has to start months before the LHC is back online because it’s going to need some serious TLC (in the form of recommissioning, debugging and tuning) following the shutdown,” LHC operation head Mike Lamont told Symmetry Magazine.
The 27 kilometer particle accelerator ring that straddles the Franco-Swiss boarder is only one component of the LHC, however. Before charged particles even reach the LHC’s monstrous super-conducting electromagnets, they must first be created and accelerated via a ‘daisy chain’ of smaller particle accelerators, each one slowly ramping-up the particles’ energies so they can be pushed to record-breaking speeds by the LHC.
On Friday, LHC engineers switched on the first component of the daisy chain: the source. The source is responsible for generating a reservoir of protons — by stripping electrons from hydrogen atoms, leaving protons behind — that can then be injected into the successive particle accelerators.
This week, engineers will start to recommission the Linac2, the first particle accelerator that gives the “beam” of protons their first boost.
Next up will be the chain’s Proton Synchrotron Booster, an accelerator that has seen the most significant upgrades since shutdown and is instrumental in pushing LHC science to the next level.
“When we get the beam going around the booster, it will be a very important moment,” said Paul Collier, the head of the beams department. “Among other things, we are making a complete upgrade of its control system, which is the nervous system of the machine.”
An interesting thing about all these successive rings of accelerators is that it’s not just the LHC that depends on the proton source, many other physics experiments at CERN are eagerly awaiting the upgraded equipment to come online.
Since the LHC’s start of high energy collisions in 2009, the huge physics machine has rarely been out of the spotlight. On July 4, 2012, physicists announced the discovery of a “new boson” in LHC data and, the following year, that boson was confirmed to be the Higgs boson — the exchange particle that endows matter with mass. Of course, the Higgs boson discovery isn’t the only groundbreaking discovery by the LHC (that list is growing fast), but it was the LHC’s prime mission to hunt down that one particle, the last undiscovered component of physics’ bedrock Standard Model.
A University of Colorado Cancer Center study recently published in the journal Cell Reports and presented today at the American Association for Cancer Research (AACR) Annual Conference 2014 shows that the cellular process of autophagy in which cells "eat" parts of themselves in times of stress may allow cancer cells to recover and divide rather than die when faced with chemotherapies.
Autophagy, from the Greek "to eat oneself," is a process of cellular recycling in which cell organelles called autophagosomes encapsulate extra or dangerous material and transport it to the cell's lysosomes for disposable. Like tearing apart a Lego kit, autophagy breaks down unneeded cellular components into building blocks of energy or proteins for use in surviving times of low energy or staying safe from poisons and pathogens (among other uses).
"What we showed is that if this mechanism doesn't work right, for example if autophagy is too high or if the target regulated by autophagy isn't around, cancer cells may be able to rescue themselves from death caused by chemotherapies," says Andrew Thorburn, PhD, deputy director of the CU Cancer Center.
A movie that accompanies the study online shows a cancer cell dying. In the first few frames, mitochondrial cell walls break down and the cell's mitochondria can be seen releasing proteins in a process abbreviated as MOMP, which is considered a common marker of cell death. But then high autophagy allows the cell to encapsulate and "digest" these released proteins before MOMP can keep the cell well and truly dead. Later in the movie, the cancer cell recovers and goes on to divide.
"The implication here is that if you inhibit autophagy you'd make this less likely to happen, i.e. when you kill cancer cells they would stay dead," Thorburn says.
Thorburn and colleagues including postdoctoral researcher Jacob Gump, PhD, show that autophagy depends on the target PUMA to regulate cell death. Specifically, when PUMA is absent, it doesn't matter if autophagy is inhibited because without the communicating action of PUMA, cancer cells continue to survive.
The finding has important implications. First, it demonstrates a mechanism whereby autophagy controls cell death. And second, the study further reinforces the clinical potential of inhibiting autophagy to sensitize cancer cells to chemotherapy.
Scientists at the Vetmeduni Vienna examined the telomere length of captive African grey parrots. They found that the telomere lengths of single parrots were shorter than those housed with a companion parrot, which supports the hypothesis that social stress can interfere with cellular aging and a particular type of DNA repair. It suggests that telomeres may provide a biomarker for assessing exposure to social stress. The findings have been published in the journal PLOS ONE.
In captivity, grey parrots are often kept in social isolation, which can have detrimental effects on their health and wellbeing. So far there have not been any studies on the effects of long term social isolation from conspecifics on cellular aging. Telomeres shorten with each cell division, and once a critical length is reached, cells are unable to divide further (a stage known as 'replicative senescence'). Although cellular senescence is a useful mechanism to eliminate worn-out cells, it appears to contribute to aging and mortality. Several studies suggest that telomere shortening is accelerated by stress, but until now, no studies have examined the effects of social isolation on telomere shortening.
Using molecular genetics to assess exposure to stress
To test whether social isolation accelerates telomere shortening, Denise Aydinonat, a doctorate student at the Vetmeduni Vienna, conducted a study using DNA samples that she collected from African grey parrots during routine check-ups. African greys are highly social birds, but they are often reared and kept in isolation from other parrots (even though such conditions are illegal in Austria). She and her collaborators compared the telomere lengths of single birds versus pair-housed individuals with a broad range of ages (from 1 to 45 years). Not surprisingly, the telomere lengths of older birds were shorter compared to younger birds, regardless of their housing. However, the important finding of the study was that single-housed birds had shorter telomeres than pair-housed individuals of the same age group.
Reading signs of stress by erosion of DNA
"Studies on humans suggest that people who have experienced high levels of social stress and deprivation have shorter telomeres," says Dustin Penn from the Konrad Lorenz Institute of Ethology at the Vetmeduni Vienna. "But this study is the first to examine the effects of social isolation on telomere length in any species." Penn and his team previously conducted experiments on mice, which were the first to show that exposure to crowding stress causes telomere shortening. He points out that this new finding suggests that both extremes of social conditions affect telomere attrition. However, he also cautions "further 'longitudinal' studies, in which changes in telomeres of the same individuals over time, are needed to investigate the consequences of stress on telomere shortening and the subsequent effects on health and longevity."
