Jul 19, 2014

Will Science Burst the Multiverse's Bubble?

Physicists aren’t afraid of thinking big, but what happens when you think too big?

This philosophical question overlaps with real physics when hypothesizing what lies beyond the boundary of our observable universe. The problem with trying to apply science to something that may or may not exist beyond our physical realm is that it gets a little foggy as to how we could scientifically test it.

A leading hypothesis to come from cosmic inflation theory and advanced theoretical studies — centering around the superstring hypothesis — is that of the multiverse, an idea that scientists have had a hard time in testing.

In its most basic sense, the multiverse is a collection of universes popping in and out of existence, bustling around in a foamy mess, embedded in a vacuum of non-zero energy. Through quantum fluctuations, universes are born while others die — each universe taking on different forms and different kinds of physics.

But, if the multiverse hypothesis has any shred of reality behind it, how can scientists prove (or at least gather some observational evidence) that we exist inside one of an infinite ocean of universes?

This question is a tough one for scientists as many critics will argue that the multiverse hypothesis is nothing more than metaphysics, or a philosophical discussion. We are forever cocooned inside our universal ‘bubble’ and can therefore never experience what is going on ‘outside’ — if, indeed, there is an outside -- so what's the point in thinking about it?

But in a thought-provoking news release from the Perimeter Institute for Theoretical Physics, in Ontario, Canada, theoretical physicists are working hard to marry the multiverse with observational science collected from the furthest-most frontiers of the Cosmos.

“We’re trying to find out what the testable predictions of (the multiverse) would be, and then going out and looking for them,” said Matthew Johnson of the Perimeter Institute for Theoretical Physics.

If the multiverse is real, it stands to reason that, in this rampaging mess of neighboring universal “bubbles,” there should be frequent collisions, much like the jostling balls in a ball pit. Johnson’s team has specifically set out to look for observational evidence of neighboring universes colliding with our own, thereby supplying some hint of observational evidence that we may have universal neighbors.

But to do this, Johnson must model the entire Universe.

“We start with a multiverse that has two bubbles in it, we collide the bubbles on a computer to figure out what happens, and then we stick a virtual observer in various places and ask what that observer would see from there,” said Johnson.

“Simulating the universe is easy.”

Although you have to admire his can-do attitude, the team aren’t simulating every atom, star or galaxy in the Universe; in fact, the computer simulation only models the largest scale structures and forces. “All I need is gravity and the stuff that makes these bubbles up. We’re now at the point where if you have a favorite model of the multiverse, I can stick it on a computer and tell you what you should see,” he said.

This is where, according to the researchers, their work is so important if we are to understand what is going on in the regions beyond our Universe.

For example, if we consider a collision-filled multiverse, Jonson’s model predicts that observations of the cosmic microwave background (CMB) radiation should exhibit rings, or ‘bruises’, where next-door universes are pushing against ours. The CMB is the ubiquitous (yet very faint) ‘echo’ of the Big Bang that can be seen at the most distant reaches of the Universe. If there’s some interaction with universal bubbles (as some multiverse hypotheses suggest), these circular bruises should be present in the CMB signal – -representing distortions in the outermost edge of our ‘bubble.’

Read more at Discovery News

Invasive 'Jumping' Earthworm Found in the Midwest

It may have made for the perfect lesson, but it was a discovery that no invasive species expert wants to make.

During a workshop on invasive species last October, University of Wisconsin-Madison Arboretum leaders took students into the field to show them, theoretically, how to survey for invasive species.

But as a Wisconsin Department of Natural Resources invasive species expert was explaining how the ground would change if a specific species of earthworms was present, the class got a much more realistic lesson than they were expecting.

“We went out to the woodlands and Bernie (Williams) was telling them about this Asian worm that we’re on the lookout for, but that’s not here yet. And then there it is, jumping and snaking around,” said Brad Herrick, an ecologist at the arboretum.

It was the first confirmed sighting of Amynthas agrestis in Wisconsin, although it’s been found in the Southeast and East since it was reported in the southern Appalachians in 1993.

The worms, also known as "jumping" or "crazy" worms, can be inadvertently transported to the United States from their native Japan and the Korean Peninsula along with imported landscape plants.

The fear of the jumping worm in a new habitat is that the forest floor will become barren, reducing the regeneration of trees and making it more hospitable for other invasive species.

“This particular invasive worm is very large and aggressive, and it reaches maturity very quickly,” explained Monica Turner, a University of Wisconsin-Madison zoology professor. “It eats its way through the soil faster than other earthworms.”

It also appears to be hardy, surviving the past winter, Wisconsin’s coldest in 35 years. Although the effect on vegetation is obvious, there has been little research on long-term effects of the worm. So Turner and her students have begun a study of the critters and hope to have some initial data by spring 2015.

“Because we know the starting conditions, we will be able to compare changes in the soils with and without the worms to see what they can do within one season, and how that varies with soils from different kinds of ecosystem,” Turner said.

A second, observational study will measure soil characteristics at locations within the arboretum that have been invaded by the worms versus locations that have not.

Ironically, the worm species that Amynthas agrestis could threaten is not native, either: The worms commonly found in Wisconsin and the Midwest arrived from Europe with the first settlers.

While the worms are not welcome, there are too many unknowns to say exactly where they fall on the spectrum of invasive species nastiness, Herrick said. Unsuspecting gardeners may actually appreciate them for the high nutrient soil they help create.

Read more at Discovery News

Jul 18, 2014

Experts urge new discipline combining benefits of neuroscience, psychology treatments

When a patient talks with a psychological therapist, what changes occur in the patient's brain that relieve mental disorders? UCLA psychology professor Michelle Craske says the honest answer is that we don't know. But, according to Craske and two colleagues, we need to find out.

Mental health disorders -- such as depression, schizophrenia, post-traumatic stress disorder, obsessive-compulsive disorder and eating disorders -- affect 1 in 4 people worldwide. Psychological treatments "hold the strongest evidence base for addressing many such conditions," but they need improvement, according to a study by Craske, Cambridge University professor Emily Holmes and MIT professor Ann Graybiel.

Their article was published online July 16 in the journal Nature.

For some conditions, such as bipolar disorder, psychological treatments are not effective or are in their infancy, the life scientists report, and a "culture gap" between neuroscientists and clinical scientists has hindered the progress of mental health treatments. The authors call on scientists from both disciplines to work together to advance the understanding and treatment of psychological disorders.

Psychological treatments, they say, have not benefitted much from the dramatic advances neuroscience has made in understanding emotions and behavior. The reason may be that neuroscientists and clinical scientists "meet infrequently, rarely work together, read different journals, and know relatively little of each other's needs and discoveries," write Craske, a faculty member in the UCLA College, and her colleagues.

The authors advocate steps for closing the culture gap: First, uncover the mechanisms of existing psychological treatments. There is, they note, a very effective behavioral technique for phobias and anxiety disorders called exposure therapy; patients learn that what they fear is not as harmful as they think, and their fears are greatly reduced by the repeated presence of the object of their fear.

Second, the paper states, neuroscience is providing "unprecedented" insights that can relieve dysfunctional behavior -- practitioners can use those insights to create new and improved psychological treatments. Third, the authors urge, the next generation of clinical scientists and neuroscientists should work more closely together. They propose a new umbrella discipline they call "mental health science" to marry the benefits of both disciplines.

"There is enormous promise," they conclude. "Psychological treatments are a lifeline to so many -- and could be to so many more."

From Science Daily

New clues to brain's wiring found by scientists

New research provides an intriguing glimpse into the processes that establish connections between nerve cells in the brain. These connections, or synapses, allow nerve cells to transmit and process information involved in thinking and moving the body.

Reporting online in Neuron, researchers at Washington University School of Medicine in St. Louis have identified a group of proteins that program a common type of brain nerve cell to connect with another type of nerve cell in the brain.

The finding is an important step forward in efforts to learn how the developing brain is built, an area of research essential to understanding the causes of intellectual disability and autism.

"We now are looking at how loss of this wiring affects brain function in mice," said senior author Azad Bonni, MD, PhD, the Edison Professor of Neurobiology and head of the Department of Anatomy and Neurobiology at the School of Medicine.

Bonni and his colleagues are studying synapses in the cerebellum, a region of the brain that sits in the back of the head. The cerebellum plays a central role in controlling the coordination of movement and is essential for what researchers call procedural motor learning, which makes it possible to move our muscles at an unconscious level, such as when we ride a bicycle or play the piano.

"The cerebellum also regulates mental functions," Bonni said. "So, impairment of the wiring of nerve cells in the cerebellum may contribute to movement disorders as well as cognitive problems including autism spectrum disorders."

His new results show that a complex of proteins known as NuRD (nucleosome remodeling and deacetylase) plays a fairly high supervisory role in some aspects of the cerebellum's construction. When the researchers blocked the NuRD complex, cells in the cerebellum called granule cells failed to form connections with other nerve cells, the Purkinje neurons. These circuits are important for the cerebellum's control of movement coordination and learning.

Bonni and his colleagues showed that NuRD exerts influence at the epigenetic level, which means it controls factors other than DNA that affect gene activity. For example, NuRD affects the configurations of molecules that store DNA and that can open and close the coils of DNA like an accordion, making genes less or more accessible. Changing the accessibility of genes changes their activity levels. For instance, cells can't frequently make proteins from genes in a tightly packed coil of DNA.

Read more at Science Daily

Dogs Were a Prehistoric Woman's Best Friend, Too

Women in a forested area 8,000 years ago were not only in close contact with dogs, but they were also eating the same food the dogs ate and suffering from one or more illnesses the dogs had.

A new study published in the Journal of Archaeological Science reveals that dogs weren’t just prehistoric man’s best friend. At least some women during the Early Neolithic period, and likely their children too, also lived very canine-centric lives.

“It is possible that females were more involved in caring for the dogs -- possibly more often the ones who fed them, organized living quarters for them, and cleaned up after them,” lead author Andrea Waters-Rist told Discovery News.

Waters-Rist, a Leiden University archaeologist, added: “One can envision a camp in the boreal forest with people and dogs living side by side, and dogs being used in many everyday tasks, with dogs being as important to the group as they are to many people today.”

Waters-Rist and her team analyzed remains from two 8,000-year-old cemeteries near Lake Baikal, Siberia. The researchers determined that women from both cemeteries had, at some point in their lives, suffered from a parasitic infection called hydatid disease, or echinococcosis.

“It’s been recognized for centuries -- mentioned in ancient Greco-Roman and Jewish texts -- and in modern times it is a relatively common infection in Northern Eurasian reindeer herders who use dogs to help with herding, and in indigenous Alaskan groups reliant on sled dogs,” Waters-Rist explained.

Cysts from the parasites, which look like calcified, egg-like objects, were found in the abdomens of the women. The researchers suspect that the cysts were probably growing in the liver of each person.

Echinococcosis in humans almost always occurs as a result of direct contact with dogs. People can also get it after ingesting food or water that has been contaminated by dog feces that contain the parasitic eggs.

“As these cysts take many years to form and may not have always preserved," Waters-Rist said, "it suggests that many more people were likely infected. So it is a piece of the puzzle in our reconstruction of the importance of dogs in the lives of ancient peoples.”

Robert Losey, a University of Alberta anthropologist, told Discovery News that he previously documented “intentional burial of dogs and wolves” at the same Siberian cemeteries.

“These dogs were much like modern Siberian huskies," Losey said. "Upon their deaths, they were carefully placed in graves just like the human dead.”

Some dogs in the Siberian cemeteries were buried with implements such as spoons and stone knives. One dog was even interred wearing a necklace.

The people living at the site appear to have been hunter-gatherers who fished for both their own supper and that of their dogs. The scientists know the dogs and people were eating similar diets based on chemical analysis of their bones.

Dogs and humans at other locations worldwide could have been equally close during prehistoric times, but proof of such connections can be harder to find where populations were low. Losey explained that dog burials tend to be more common finds in areas where diets were rich in aquatic foods, because such spots generally had denser human populations.

Read more at Discovery News

The Aquatic Menace That Gives the Worst Hickeys Ever

Lampreys are best known for their dashing blue eyes.
To quote the great Austin Powers, when provided floss to escape being lowered into a tank of ill-tempered sea bass: “OK, I get it. I have bad teeth.” Sure, it’s easy to stereotype the British for shunning American advances in oral hygiene. But it’s time to set our dental differences aside and celebrate the most ghastly mouth on Earth, which swims in the rivers of both nations, uniting us in toothy horrors.

Say hello to the lamprey, an ancient eel-like critter that’s the bane of many a river system, latching onto fish like trout and draining their blood or scraping away their flesh right down to the bone. In the Great Lakes of North America they’re an invasive menace, wreaking havoc on fisheries that tend to rely on their catches not having giant hickeys.

But all the while, let’s give respect where respect is due. This is an animal that has gone 360 million years almost totally unchanged, a brilliant parasite that’s evolved a remarkably efficient—and disturbing—means of survival.

The Scrapes of Wrath

There are three kinds of lamprey: the flesh-eaters, the blood-suckers, and the ones that quite frankly don’t do much at all. These last individuals spend anywhere from 3 to 7 years in a larval stage, and live only 6 months once they metamorphose into adults. During this time they don’t need to feed, only existing to reproduce and die (there are worse fates, I suppose).

The other two populations, though, are where things get interesting. The flesh-eaters and blood-suckers may not look like they have all that different mouths, but to a trained professional like lamprey taxonomist Claude Renaud of the Canadian Museum of Nature, the dental specializations of the two groups are quite clear.

In the center of all those impressive hooked teeth, lampreys have a structure analogous to a tongue, epically called a piston, which bears three sharp chompers, two that move side to side and another that moves up and down. This piston, according to Renaud, “has kind of a convex structure with a very strong middle tooth that’s very large, and that’s the one that permits the lamprey that feeds on flesh to remove—gouging out—a piece of flesh.”

The seven holes behind a lamprey’s eyes are its strangely round gills. If a lamprey thinks these will at all distract from its ridiculous mouth, it’s got another thing coming.
This middle tooth of the flesh-eaters is shaped like a U, in contrast to that of the blood-suckers, which looks like a W. The latter group has “finer teeth, all of them about the same size,” said Renaud. “So this W actually acts as a rasping organ instead of a gouging organ, so that permits it to kind of scrape all the tissue to get to the blood vessels.”

And another key difference between the two groups lies within the critters’ bodies. The blood-suckers have to keep that blood flowing, so they have glands in their throat that secrete an anticoagulant into the oral disk, as their mouth is not-so-seductively known. The flesh-eaters have these as well, but they’re far smaller—they’re after meat, not blood.

No matter its manner of feeding, the lamprey has to of course first find its prey, using cells along its body that help it sense vibrations in water. Once it identifies and closes in on the prey, it switches to visual cues to actually pinpoint a specific spot on the unfortunate host.

“If they’re flesh-feeders they will preferentially go for the [top] of the fish, because that’s where the most flesh is,” said Renaud. “Whereas if they’re a blood-feeder they’ll go for the underside of the fish, because that’s where they’ll get the greatest blood supply.”

A migrating salmon with a rather unwelcome passenger. Lampreys, if you were curious, are real backseat drivers.
And once they hit their target, there’s not much that can dislodge them, probably not even tickling them, though I don’t think that’s really been tested. Not only do those multitudinous hooked teeth sink deep into the flesh (Renaud will find fish with scars that are so defined that he can identify the offending species of lamprey based on the imprint’s dentition), but the lamprey also uses suction to stick to its host.

Running along the edge of the oral disk are two rings of structures. “One of them is called oral fimbriae, these are little structures that look a little bit like leaves, little flaps of tissue,” said Renaud. “And those are the ones that can adhere closely to the skin and make a really good seal.” (A nice little bit of convergent evolution here, that is, two unrelated species arriving at the same adaptation independently: The clingfish has modified fins on its belly that utilize similar structures to create a suction so strong that it can support 300 times its own weight.)

The other ring around the lamprey’s oral disk is made of conical structures known as papillae, which the creature uses to sense where best to attach to the fish. These are so sensitive that the vampiric varieties of lamprey can even use them to feel out underlying blood vessels.

“Excuse us, but do you have a moment to talk about our lord and savior Jesus Christ? Hello?”
Once the lamprey is firmly attached, it’ll stay stuck for anywhere from a few hours to a full day, rasping or gouging, then resting for a bit, then back to rasping or gouging. The blood-suckers will typically leave their prey alive after the whole ordeal, “because it’s not advantageous for a parasite, if you wish, to kill its host, because then it won’t have the ability to feed on that one again,” said Renaud. “And the host can recover, replenish its blood supply, and remain there for another meal.” Still, some die of resulting infections.

The flesh-eaters, though, laugh in the face of such mercy. They’re typically targeting smaller schooling fish like herring, boring and boring until “they’ll actually skeletonize the fish that they’re feeding on,” according to Renaud. The fish either dies from massive blood loss or infection or, you know, just having a big hole in its body.

Pissing Off America and Canada, and Other Lamprey Pursuits

Luckily for its hosts, the lamprey spends less than half of its life as a menacing adult, maybe 3 out of its 7 years. The rest of the time is spent in a rather laid-back larval stage on river bottoms, dug into the sand and detritus with their heads poking out. In this way the blind young simply wait for their food to come to them, microorganisms like plankton and algae, gathering it all in their squishy horseshoe-shaped mouths (which of course metamorphose into the fearsome maws of adulthood). The food enters a sort of filtering system of branching structures, where it gets entangled in a mucus strand that then enters the gut.

Strangely enough, it’s actually these fairly helpless larval lampreys that lead the adults to optimal spawning grounds. “The larvae can produce a pheromone that will disperse into the water system,” said Renaud. “And the adults, when they want to go to spawn, will pick up that through their nose, and are able to go and spawn where it’s great larval habitat. So it’s like the babies tell the prospective parents, ‘This is a great place to spawn, because we’re thriving.’”

A larval lamprey. Notice the mouth is fleshy instead of being positively packed with teeth. Give it time, though, and it’ll develop nice chompers. Wait … actually. Yeah … this one’s dead.
This is quite different from salmon, which when spawning famously return to the exact spot they were born, as if terribly homesick. But that spot may not necessarily be as ideal that year as when they themselves called it home. Alternatively, the lampreys, under the direction of their larval comrades, can guarantee more ideal conditions for the development of their young.

This success is nice and all—unless you’re a wildlife official around the Great Lakes. Here the U.S. and Canada are battling the invasive blood-sucking sea lamprey, which can split its time between saltwater and freshwater. Accidentally introduced here in the early 20th century, this species has proved to be an absolute fiend. Before the lampreys showed up, the Great Lakes trout fishery produced 15 million pounds a year. In the early ‘60s, after the lampreys were well established in the area, one annual catch totaled a mere 300,000 pounds. So while not as destructive as the flesh-eating variety, these blood-suckers inflict more than their fair share of lethally infectious wounds.

Fish always look surprised, so it’s hard to tell if this one is in pain or if that’s just its normal face. Actually, we can be pretty sure it’s in a good amount of pain. Anyway, lamprey bites can lead to deadly infections, potentially crashing certain fisheries.
And boy have officials struggled to keep the sea lamprey at bay. Beginning in the late ’50s, at first they tried trapping them, and then containing them with electrical barriers. Nowadays, though, scientists are looking into more clever measures.

One idea is to use the lamprey larva’s come-spawn-over-here pheromone against the species, dumping it in strategic spots in a river system, then scooping up the hoodwinked adults. Even more cunningly, scientists have been sterilizing captured males and releasing them back into the wild. That may seem silly, what with it being easier to just kill them, but in their competition to mate, these males will necessarily muscle out some of the fertile lampreys, reducing the spawning success rate. Still another campaign has used lampricides that lure larvae out of their burrows and eventually kill them.

With these efforts, the U.S. and Canada have been able to cut sea lamprey populations in some parts of the Great Lakes by 95 percent. But, Renaud notes, that remaining 5 percent will rapidly replenish the population if left unchecked. And with a dizzying network of streams and rivers in the area, some spots can’t be treated more than once every few years. “So we can never eradicate sea lamprey, but we can control it,” Renaud said. “That’s why it’s called sea lamprey control instead of sea lamprey eradication.”

Read more at Wired Science

Jul 17, 2014

Tooth plaque provides unique insights into our prehistoric ancestors' diet

An international team of researchers has found new evidence that our prehistoric ancestors had a detailed understanding of plants long before the development of agriculture.

By extracting chemical compounds and microfossils from dental calculus (calcified dental plaque) from ancient teeth, the researchers were able to provide an entirely new perspective on our ancestors' diets. Their research suggests that purple nut sedge (Cyperus rotundus) -- today regarded as a nuisance weed -- formed an important part of the prehistoric diet.

Crucially, the research, published in PLOS ONE and led by the Universitat Autònoma de Barcelona and the University of York, suggests that prehistoric people living in Central Sudan may have understood both the nutritional and medicinal qualities of this and other plants.

The research was carried out at Al Khiday, a pre-historic site on the White Nile in Central Sudan. It demonstrates that for at least 7,000 years, beginning before the development of agriculture and continuing after agricultural plants were also available the people of Al Khiday ate the plant purple nut sedge. The plant is a good source of carbohydrates and has many useful medicinal and aromatic qualities.

Lead author Karen Hardy, a Catalan Institute for Research and Advanced Studies (ICREA) Research Professor at the Universitat Autònoma de Barcelona (UAB) and an Honorary Research Associate at the University of York, said: "Purple nut sedge is today considered to be a scourge in tropical and sub-tropical regions and has been called the world's most expensive weed due to the difficulties and high costs of eradication from agricultural areas. By extracting material from samples of ancient dental calculus we have found that rather than being a nuisance in the past, its value as a food, and possibly its abundant medicinal qualities were known. More recently, it was also used by the ancient Egyptians as perfume and as medicine.

"We also discovered that these people ate several other plants and we found traces of smoke, evidence for cooking, and for chewing plant fibres to prepare raw materials. These small biographical details add to the growing evidence that prehistoric people had a detailed understanding of plants long before the development of agriculture."

Al Khiday is a complex of five archaeological sites which lie 25km south of Omdurman; one of the sites is predominantly a burial ground of pre-Mesolithic, Neolithic and Later Meroitic age. As a multi-period cemetery, it gave the researchers a useful long-term perspective on the material recovered.

The researchers found ingestion of the purple nut sedge in both pre-agricultural and agricultural periods. They suggest that the plant's ability to inhibit Streptococcus mutans, a bacterium which contributes to tooth decay, may have contributed to the unexpectedly low level of cavaties found in the agricultural population.

Dr Stephen Buckley, a Research Fellow at the University of York's BioArCh research facility, conducted the chemical analyses. He said: "The evidence for purple nut sedge was very clear in samples from all the time periods we looked at. This plant was evidently important to the people of Al Khiday, even after agricultural plants had been introduced."

Dr Donatella Usai, from the Instituto Italiano per l'Africa e l'Oriente in Rome led the excavation and Dr Tina Jakob from Durham University's Department of Archaeology, performed the analysis of the human remains at Al Khiday. Anita Radini, an Archaeobotanist at the University of Leicester Archaeological Service (ULAS) and a PhD candidate at BioArCh, University of York, contributed to the analysis of microfossils found in the dental calculus samples.

Dr Usai said: "Al Khiday is a unique site in the Nile valley, where a large population lived for many thousands of years. This study demonstrates that they made good use of the locally available wild plant as food, as raw materials, and possibly even as medicine."

Read more at Science Daily

Untangling spider's webs: Largest-ever study of spider genetics shows orb weaver spiders do not share common origins

For decades, the story of spider evolution went like this: As insects became more and more diverse, with some species taking to the skies, spiders evolved new hunting strategies, including the ability to weave orb-shaped webs to trap their prey.

From that single origin, the story goes, orb-weaver spiders diverged along different evolutionary paths, leading to today, where several species weave similar -- though not identical -- webs.

It's a good story, but there's just one problem -- Harvard scientists now know it's not true.

The largest-ever phylogenetic study of spiders, conducted by postdoctoral student Rosa Fernández, Gonzalo Giribet, Alexander Agassiz Professor of Zoology, and Gustavo Hormiga, a professor at George Washington University, shows that, contrary to long-held popular opinion, the two groups of spiders that weave orb-shaped webs do not share a single origin. The study is described in a July 17 paper published in Current Biology.

"This study examines two different groups of orb-weaver spiders, as well as several other species," Giribet said. "Using thousands of genes, we did a comparative phylogenetic analysis, and what we now know is there is not a single origin for the orb-weaver spiders.

"There are two possible explanations for this," he continued. "One is that the orb web evolved far back in the lineage of the two groups, but has been lost in some groups. The other option is that the orb web evolved independently in these two groups. We still haven't resolved that question yet -- we need to sample many more of these intermediate groups before we can say which option is correct."

The belief that orb-weaver spiders shared a common origin, Giribet said, came largely from earlier morphological studies.

Even as new genetic tools became more commonplace in the last two decades, the single origin theory held sway, in part, because early phylogenetic studies relied on just a handful of genes to draw a picture of the spider evolutionary tree.

"Some early analyses pointed out that spiders with orb webs didn't form a group -- they appeared in different places along the tree," Giribet said. "But the genes that were being used weren't enough to elucidate the evolution of a very diverse group like spiders, so most people dismissed many of those results."

In recent years, however, sequencing technology has dropped dramatically in cost, meaning researchers who once were able to study only a handful of genes can now examine the entire genome of a particular organism.

"The technology has changed what we are able to do in terms of the questions we can ask and the questions we can answer," Giribet continued. "Even just five years ago, we were spending thousands of dollars to sequence 3,000 genes. Today, we're spending just a few hundreds of dollars to sequence millions, which is almost an entire genome.

In the case of Giribet and Fernández, the technology allowed them to sequence genes from 14 different spiders, creating the largest genomic data set for the study of spiders.

"This paper is at the forefront of how these large data sets are being analyzed, and how we are now constructing phylogenies using molecular data," Giribet said. "We can now test all possible pitfalls of phylogenetic interference to make sure our results are as accurate as possible."

Though his hunch, Giribet said, is that the two orb-weaver groups evolved independently, he's now designing a study that will examine the genetics of as many as 150 spider species to test that hypothesis.

Read more at Science Daily

Fantastically Wrong: The Strange History of Using Organ-Shaped Plants to Treat Disease

According to the doctrine of signatures, plants and nuts and vegetables that resemble a human body part or organ must be divined by God to treat said limb or organ. Thus should a walnut fix your brain if it gets too wrinkled … or something.
It’s hard to imagine being the first human being to look at a plant like, say, a stinging nettle and think, “I probably shouldn’t eat this, on account of the general agony it would cause me. But what if I cooked it first?” So you prepare it and nervously drop it down your gullet—and luckily enough, it turns out to be edible. But what if it hadn’t been? And what if there wasn’t a decent gastroenterologist nearby?

For tens of thousands of years before modern medicine, choosing plants that not only wouldn’t kill you, but could cure you of ills was an exercise in trial and error. So wouldn’t it be nice if nature (or God, who I guess would also be nature in a way) dropped hints as to which ones were good for the human body? Such thinking, known as the doctrine of signatures, actually developed with remarkable frequency all around the world from culture to culture. Plants meant to heal certain organs and body parts, like the liver or the eye, must show a certain “signature” by resembling the thing they treat.

So the bloodroot, with its red extract, was theorized to fix problems with blood. And the saxifrage, which breaks apart rocks as it grows, must relieve kidney stones. Venomous bites are covered too: Alkanet’s viper-shaped seeds help for snake bites, and the coiled shoots of the herb scorpius will take care of that scorpion sting lickety-split. Even using plants that grow in the same area where a disease like malaria is prevalent can be used as cures.

A 1923 reconstruction of an illustration from Giambattista Della Porta’s Phytognomonica of 1608. Eyebright, according to the doctrine of signatures, resembles the human eye and must therefore be effective at treating eye infections. But only if the eye is still in your head, not floating around disembodied like these ones.
We now know that this is both wildly wrong and wildly dangerous. A sliced mushroom may look like an ear, but that doesn’t mean you should eat it to cure your earache (choose the wrong mushroom and you can add 24 hours of talking to furniture to your troubles). But as we shall see, the doctrine of signatures, when properly applied, has in fact been for some cultures an indispensable tool in medicine.

Long before the theory popped up in the West, peoples all over the world subscribed to what we now call the doctrine of signatures, from Asia to the New World. Native American tribes all used it, according to Bradley C. Bennett in his essay “Doctrine of Signatures: An Explanation of Medicinal Plant Discovery or Dissemination of Knowledge?” The Cherokee, for instance, thought the common purslane’s stalks, which resemble worms, could be used to treat worms in humans.

In the West the doctrine was first mentioned in the writings of Pliny the Elder, the brilliant Roman naturalist whose imagination nevertheless often outpaced his grounding in reality. In the 1500s, German-Swiss physician Paracelsus wrote at length on the topic, claiming that “the soul does not perceive the external or internal physical construction of herbs and roots, but it intuitively perceives at once their Signatum.”

The 16th-century physician Paracelsus wrote extensively on the doctrine of signatures, apparently in a teeny-tiny notebook.
During the 16th and 17th centuries, the doctrine of signatures was ubiquitous in the West. According to Bennett, the view was a decidedly theological one: God, in all his/her benevolence, shapes certain plants to resemble human organs as a clue, and we need to take the hint. And if you don’t take the hint, well, God will force it on you. In Milton’s Paradise Lost, first published in 1667, the Archangel Michael uses the eyebright flower to cure Adam’s eye infection.

And there was the British botanist William Coles, writing a decade before that epic poem: “Though Sin and Satan have plunged mankinde into an Ocean of Infirmities, yet the Mercy of God, which is over all his workes, maketh Grasse to grow upon the Mountaines and Herbes for the use of men, and hath not only stamped upon them a distinct forme but also hath given them particular Signatures whereby a man may read the use of them.”

This theological grounding is quite problematic, in the sense that it assumes the universe was created for humankind, then stocked with convenient medicines for the taking, the kind of anthropocentric worldview also manifested in the geocentrism that Copernicus overthrew in the 16th century. There’s also the rather glaring issue of subjectivity: That root may look like a kidney to you, but it sure looks a lot like a liver to me.

Not that he needed to disprove the theory, but in his essay Bennett presents the findings of his research into the efficacy of various plants with heart-shaped leaves in treating heart disease. Searching various databases, he found 2,584 plants with such a shape, and randomly selected 80. Of those 80, only 21 were used in medicine, and of those only three applied specifically to cardiac medicine. “These data clearly refute any a priori value of heart-shaped leaves as signs for cardiac activity,” he writes. Translation: Don’t go around eating morning glory leaves to try to cure your heart murmurs.

The Archangel Michael, at left, was an early proponent of both sweet perms and the doctrine of signatures, using eyebright to restore Adam’s eyesight in Paradise Lost. Also, that kid is about to find out the hard way that pet fish don’t survive too good when walked on leashes.
And even in the heyday of the doctrine of signatures there were plenty of detractors. The 16th century Flemish physician Rembert Dodoens called it “absolutely unworthy of acceptance.” Even Samuel Hahnemann, who founded the practice of homeopathy, vehemently attacked the doctrine, which would turn out to be just as epically wrong as his own theory. He said in 1825 with an irony so hilarious it’s almost incomprehensible: “I shall spare the ordinary medical school the humiliation of reminding it of the folly of those ancient physicians who, determining the medicinal power of crude drugs from their signature, that is, from their color and form, gave the testicle-shaped Orchitis-root in order to restore manly vigour…”

Hahnemann and Dodoens were right, of course. But there is the problem of these supposed cures that … uh … actually work. The doctrine of signatures, it turns out, isn’t totally worthless bunk. The Cherokee’s worm-like purslane, writes Bennett, is indeed “effective in controlling intestinal parasite loads and has gastroprotective activity.” And the Archangel Michael’s eyebright, he adds, can be loaded into eye drops to treat infections of the peepers.

This orchid is good for those times when half of your penis falls off.
This could be coincidence, sure. But more likely it’s the fact that the doctrine of signatures has at times not been used to identify cures, but to remember them, and in that way has been quite beneficial for peoples without a written language. Where the vast majority of scholars have roundly dismissed the doctrine as silly pseudoscience, Bennett sees the mnemonic benefits of the theory. That is, its use as a device to memorize what plants can repair what problems in the human body.

He cites another scholar, writing in 2002 about the medicine of the native Peruvian peoples: “In these and other orally transmitted systems of thought, mnemonic cues may be essential to the viability of knowledge transmission. Plants that are both efficacious and easy to remember are more likely to be maintained in the pharmacopoeia of non-literate societies through time.”

In Europe, too, the doctrine of signatures was often applied after the plant’s efficacy had already been established. Bennett relates, for instance, the story of the discovery of willow bark’s powers. A reverend by the name of Edward Stone had accidentally tasted it, and found that its bitterness was much like that of cinchona bark, used to treat malaria. He then discovered that the willow could also be used to treat fevers, malarial or otherwise. And this, he concluded, is because the willow “delights in a moist and wet soil,” an environment where malaria is common. Cures, he reasoned, must occur near their causes.

Read more at Wired Science

520-Million-Year-Old Sea Monster Unearthed in China

A spectacularly well-preserved sea monster that once prowled the oceans during the Cambrian Period has been unearthed in China.

The 520-million-year-old creature, one of the first predators of its day, sported compound eyes, body armor and two spiky claws for grabbing prey.

The fossils of the new species were so well preserved that the nervous system and parts of the brain were still clearly defined.

Before the Cambrian Period, which lasted between 543 million and 493 million years ago, most life resembled simple algae and stationary jellyfishlike creatures, but during the Cambrian explosion, a period of rapid evolution when biodiversity exploded, swimming sea creatures with compound eyes, jointed legs and hard exoskeletons emerged.

The period also saw the rise of an iconic group of shrimplike creatures known as anomalocaridids. These ancient sea monsters were the top predators of the Cambrian seas, and sported bladed body armor and a cone-shaped mouth made of concentric plates. Some of the biggest of these bizarre creatures could grow to be up to 6 feet (1.8 meters) long.

But most anomalocaridid specimens paleontologists found have been poorly preserved, making it difficult to know precisely where they fit in the tree of life, said study co-author Peiyun Cong, a researcher at Yunnan University in China.

Some scientists thought anomalocaridids belonged to a group that split off before the most recent common ancestor of all living arthropods, while others thought the animals were part of a group called chelicerates that includes spiders and scorpions. Still others thought anomalocaridids had converged upon similar features to those of modern arthropods but didn't evolve from the same lineage, Cong said in an email.

In the last several years, the researchers unearthed three spectacularly preserved specimens of a new species of anomalocaridid in fossil sediments in China. The sediments had frozen these creatures in time so perfectly that the entire nervous system, as well as the gut and some muscles, were still visible.

The creature, dubbed Lyrarapax unguispinus, was about 6 inches (15 centimeters) long.

"The three known specimens may represent immature stages of the animal, so it might be larger," Cong wrote in an email to Live Science.

L. unguispinus had a tail that looked a bit like that of a lobster, and two giant pincers for grasping prey. As it grew, the creature molted, shedding its outer cuticle.

Read more at Discovery News

Jul 16, 2014

Testicle-Munching Fish: All That Dangerous?

A sharp-toothed, testicle-biting cousin to the piranha has been pulled up by a woman fishing in Lake St. Clair, located near Detroit, Mich. The fish measured around two feet in length and weighed 15 pounds, according to Tech Times.

The fish is the pacu, a vegetarian who, although it prefers fruits and nuts that drop into the Amazon River and its tributaries, has been known to confuse nuts for human flesh. The pacu caught in Michigan was caught on a hook that was baited with a nightcrawler and catfish.

In Papua New Guinea, where the pacu has also escaped, it is believed to have mistaken male reproductive organs for nuts. Two fishermen were reportedly were bitten and bled to death in 2011, according to Jeremy Wade, host of Animal Planet’s “River Monsters.”

The same Amazonian nut-cracking fish was caught in Oresund Strait between Denmark and Sweden last year and, in 2012, found in a lake in Illinois.

Despite past reported incidents, one Amazon fishing guide says the pacu is not aggressive, but is good to eat.

“I like to pan fry it, or bake it,” said Anthony Giardenelli, owner of Otorongo Expeditions, a tour company that takes trips throughout in the Peruvian Amazon. “It’s very tasty,” he said by phone from his office in Iquitos.

Giardenelli has caught dozens of pacu fish each season as the floodwaters of the Amazon drive fish into the forest in search of food.

“They have evolved migrating in and out of flooded waters to eat fruit and nuts,” Giardenelli said. “They are attracted to anything splashing. Rubber tree seeds are one of their favorites. They are very hard-wired to follow a plopping noise in the water.”

Giardenelli says he has heard the sound of pacu cracking nuts under water from a boat on the surface. “It sounds like two pool balls clacking together,” he added.

Experts believe the pacu could be spreading to these other waterways around the world by hobbyists who dump the fish overboard when they get too big for the home aquarium.

“It’s a plant eater,” said Stefan Tanner, an editor and translator at Amazonas Magazine. “If you release it in Denmark, it won’t survive the winter. If you release it in Florida, it may swim for a long time. Will it reproduce? That’s another question.”

Read more at Discovery News

Ancient Priest's Tomb Painting Discovered Near Great Pyramid

A wall painting, dating back over 4,300 years, has been discovered in a tomb located just east of the Great Pyramid of Giza.

The painting shows vivid scenes of life, including boats sailing south on the Nile River, a bird hunting trip in a marsh and a man named Perseneb who's shown with his wife and dog.

While Giza is famous for its pyramids, the site also contains fields of tombs that sprawl to the east and west of the Great Pyramid. These tombs were created for private individuals who held varying degrees of rank and power during the Old Kingdom (2649-2150 B.C.), the age when the Giza pyramids were built.

The new painting was discovered in 2012 by a team from the Institute of Oriental Studies of the Russian Academy of Sciences, which has been excavating these tombs since 1996.

A surprise discovery

Scientists discovered the painting when they began restoring the tomb of Perseneb, a man who was a "priest" and "steward," according to the tomb's inscriptions.

His tomb, located 1,000 feet (300 meters) east of the Great Pyramid of Giza, contains an offering room, central room and burial chamber. The three rooms contain 11 statues showing depictions of Perseneb and members of his family. First recorded in the 19th century by the German explorer Karl Richard Lepsius and French Egyptologist Auguste Mariette, the tomb is believed to date to the middle or late fifth dynasty (ca. 2450-2350 B.C.). The fifth dynasty is a time period within the Old Kingdom.

"Known since the 19th century, the could hardly present any new principal features. Therefore, it was a real surprise to discover an Old Kingdom painting on the eastern wall of the central room," wrote Maksim Lebedev, a reader (the American equivalent is a professor) at the Russian State University for the Humanities, in an email to Live Science.

"The painting was made on a thin layer of fine white plaster darkened with 19th-century soot and dirt. By the time of recording, only about 30 percent of the original plaster had preserved on the wall," Lebedev said.

Since the 19th century, the growth and industrialization of Cairo has led to problems with pollution at Giza. And the fact that people were actually living inside the tomb in some periods (including the Middle Ages) also damaged the painting, Lebedev said.

Nevertheless, "none of the scenes has been lost completely. The remaining traces allow [for the] reconstruction the whole composition," Lebedev said.

Scenes of life

The reconstructed painting reflects ancient life. At the top of the painting there are images of boats sailing the Nile River, their sails pointing south. They "probably represent the return of the owner from the north after a pilgrimage or inspection of his funerary estates," Lebedev said. Funerary estates were tax-exempt property left by the deceased to help support surviving dependents and the upkeep of his tomb.

The painting's "two lower registers preserved representations of various agricultural scenes: plowing, sowing, workers driving sheep over sown seed, driving donkeys laden with sheaves to the threshing floor," Lebedev said.

The painting also shows an image of Perseneb, his wife and what appears to be his dog. There is also a marsh scene with a man on a boat who appears to be bird hunting.

"All the depicted scenes had important symbolic meanings. Fowling (bird hunting) in the marshland could refer to the ideas of rebirth and taming of chaotic forces," Lebedev said. "The full agricultural sequence relating to crops represents the most crucial event in the life of ancient Egyptian society," he added. Also, the representation of "boats with sails going southwards is another important tomb subject, which reflected the high status of the person."

More discoveries to come

The area the Russian team has been excavating contains a number of tombs that may hold undiscovered wall paintings. The team has found indirect evidence for paintings in some tombs, such as very smooth walls and remains of wall plaster and paint, Lebedev said.

"Since many rock-cut chapels of the eastern edge of the Giza plateau were rapidly excavated or just recorded [without excavation] in the first half of the 20th century, sometimes without sufficient documentation, and still covered with thick layers of rough plaster left from later inhabitants [who lived in the tombs], one may expect that more paintings will be discovered in this part of the necropolis."

Read more at Discovery News

Mysterious, Giant Crater Appears in Siberia

Scientists are scratching their heads about an 80-meter-wide hole recently discovered in a remote part of Siberia called Yamal (which means "end of the world.")

No one is yet sure what's caused the hole -- a scientific team was traveling to the site Wednesday to investigate. Experts from the Centre for the Study of the Arctic and the Cryosphere Institute of the Russian Academy of Sciences planned to take soil, air and water samples, the Siberian Times reported.

The massive hole resembles a deep sinkhole -- it's not clear how deep yet -- but a ring of soil around the edge appears to have been thrown outside of the crater.

Speculation about the cause of the hole includes an underground gas explosion or a meteorite hit.

Anna Kurchatova from the Sub-Arctic Scientific Research Centre told the Siberian Times that global warming, which is causing permafrost melting in Siberia, could have released gas trapped in the ice.

A spokesman from Russia's Emergencies Ministry told the Siberian Times it's unclear what caused the hole, but ruled out a space rock.

"We can definitely say that it is not a meteorite," he said.

From Discovery News

When Fish Go Deeper They Glow Brighter

Deep-diving fish have a problem: The only light that penetrates their watery environment is blue and green — hardly enough of a palette for flashy color patterns.

Now, a new study reveals these fishes' solution: In deep water, fish simply fluoresce more — a technique that allows them to convert blue-green light into red light.

"Under light conditions that do not provide the full spectrum — the full rainbow of colors that we have at the surface — it's really nice to have fluorescence, because you can still have those missing colors," said study researcher Nico Michiels, a professor at the University of Tüebingen in Germany.

Most color pigments work by absorbing some portions of the light spectrum and bouncing the rest back. A yellow flower, for example, absorbs blues, greens and reds, and sends yellow shooting back toward the eye of the observer.

Fluorescence is slightly different. The molecules responsible absorb one wavelength of light and then emit another, longer wavelength. This occurs through a process of excitation, in which the molecule absorbs light energy and then emits a lower-energy wavelength than the one it absorbed, in order to return to its resting state.

Many marine animals fluoresce, frequently in colors not visible to the human eye without filters. Researchers studying fluorescent corals have suggested that these colors might help protect against sun damage. Another theory holds that fluorescence provides marine organisms more freedom of color, thus enhancing communication and camouflage.

If fluorescence is mostly a tool used for UV protection, you'd expect to see more of it in shallow waters, where UV light can penetrate, Michiels told Live Science. On the other hand, if fluorescence is mostly a decorative, visual touch, it would be more likely to appear in deeper waters, where fish don't need UV protection but do have less of the visible light spectrum to work with.

Michiels and his colleagues dove to depths of 16 feet (5 meters) and 66 feet (20 m) at sites in the Mediterranean Sea, Red Sea and East Indian Ocean. They collected specimens of eight species of fish known to fluoresce, including five types of gobies and a species of the long, slender seahorse relative known as the pipefish.

Back on land, the fish were housed in aquariums and tested for fluorescence the same day using a spectrometer, which measures the spectrum of light generated by an object. The measurements revealed that fish caught at depths of 66 feet fluoresced red more readily than fish of their same species caught at 16 feet below the water's surface.

"In some species, the difference is quite impressive," Michiels said. "Some of these species are six times more fluorescent in deeper water than in shallow water."

Red wavelengths of light are rapidly absorbed by water and aren't present in deep waters, Michiels said. Thus, traditional pigmentswould be useless for creating red coloration. Red pigments simply look gray without that portion of the spectrum to bounce off them, much like the clothes in your closet all look indistinguishably gray when you try to pick out a sweater without turning on the lights.

The fish "can use the ambient light, which can be blue or green — it doesn't matter —and transform it into red or yellow," Michiels said. The fish can be red in a blue environment, if they fluoresce, he added.

Read more at Discovery News

Jul 15, 2014

Curiosity Finds Large Iron Meteorite on Mars

On Curiosity’s 640th day (or sol) on Mars, as it continued its long drive to the base of Aeolis Mons (a.k.a. Mount Sharp), the robot stumbled across a fairly hefty meteorite. Shown here, the 2-meter-wide iron space rock can be seen embedded in the ruddy regolith.

The May 25 find adds to the puzzling reasons as to why the majority of meteorites found on the Martian surface are iron rich. On Earth, though fairly common, iron-rich meteorites are outnumbered by stony ones, leading scientists to believe that large iron-rich specimens may be more resistant to Martian erosion processes than stony space rocks.

This large meteorite appears to consist of two separate components dubbed “Lebanon” (the larger meteorite) and “Lebanon B” (the smaller one in the foreground) by Curiosity’s mission scientists.

Curiosity spent some time photographing and analyzing the meteorite with its Remote Micro-Imager (RMI), a component of the mission’s Chemistry and Camera (ChemCam) instrument. The RMI images are the circular inserts in the image above. The rover’s Mastcam instrument also imaged the area, adding color and context to the observation.

Like other iron meteorites observed by Curiosity, and NASA’s Mars Exploration Rovers Opportunity and Spirit, this example is riddled with pockmarks and cavities. According to a NASA news release, these features may be caused by “preferential erosion along crystalline boundaries within the metal of the rock.” It’s also possible that the cavities used to contain olivine crystals — often found in a rare type of stony-iron meteorites called pallasites. The olivine would have long since eroded away, leaving the iron behind.

From Discovery News

Stolen 'Nest of Dinosaurs' Returned to Mongolia

More than 18 dinosaur skeletons illegally taken from Mongolia were formally returned to their homeland last week, U.S. authorities announced.

The fossilized bones were handed over to Mongolian officials in a repatriation ceremony held July 10 in New York. "Today, we return a veritable nest of dinosaurs," Manhattan U.S. Attorney Preet Bharara said in a statement after the ceremony.

"This is a historic event for the U.S. Attorney's Office, in addition to being a prehistoric event, and we are proud to participate in the return of these dinosaur skeletons to their rightful home," Bharara said.

The road to repatriation began two years ago, in 2012, when an auction house in New York was offering a skeleton of a Tarbosaurus bataar — an Asian cousin of Tyrannosaurus rex. Mongolian authorities voiced concern that the specimen had likely been smuggled into the United States. The 70-million-year-old dinosaur species was native to the Gobi desert in Asia, and to date, has only been found in modern-day Mongolia.

The Tarbosaurus sale attracted a bid of more than $1 million, but the suspicions of the Mongolian authorities sparked a long legal battle and federal investigation. U.S. authorities froze the sale, and after a lengthy custody battle, the specimen was returned to Mongolia in May 2013.

Eric Prokopi, a self-described commercial paleontologist who imported the dinosaur, pleaded guilty to criminal charges that he smuggled the skeleton and other fossils into the United States. In June, Prokopi was sentenced to three months in federal prison.

The other Mongolian fossils forfeited by Prokopi during the case were returned in the July 10 ceremony, including a second Tarbosaurus, oviraptors and skeletons of the duckbilled, plant-eating Saurolophus angustirostris.

Federal authorities also returned fossils that had been forfeited by Christopher Moore, a onetime business partner of Prokopi in the United Kingdom, including a third Tarbosaurus, skeletons of a rooster-like Gallimimus dinosaur and a nest of fossilized eggs, all looted from Mongolia.

Read more at Discovery News

Medieval Italian Skeleton Reveals Livestock Disease

A sip of unpasteurized sheep or goat's milk may have spelled doom for a medieval Italian man.

A new genetic analysis of bony nodules found in a 700-year-old skeleton from Italy reveal that the man had brucellosis, a bacterial infection caught from livestock, when he died. It's not clear if the disease killed the man, but he likely would have suffered from symptoms such as chronic fatigue and recurring fevers, according to the researchers who analyzed the bones.

This medieval Italian man joins many other long-dead people in getting a postmortem diagnosis of brucellosis. Signs of the disease have been found in skeletons from the Bronze Age and earlier. In fact, the disease predates modern humans: In 2009, researchers reported possible signs of brucellosis in a specimen of the human ancestor Australopithecus africanus, who lived more than 2 million years ago.

The brucellosis-infected Italian came from Sardinia. He was buried in a medieval village called Geridu, which was abandoned sometime in the late 1300s, and was probably between 50 and 60 years old when he died.

Archaeologists found 32 bony nodules scattered in the man's pelvic region, the largest about 0.9 inches (2.2 centimeters) in diameter. Such nodules are often a sign of tuberculosis, a lung infection caused by the bacterium Mycobacterium tuberculosis. Tuberculosis is the most common culprit in cases of calcified nodules, study leader Mark Pallen, a microbial genomist at Warwick Medical School in England, said in a statement.

Pallen and his colleagues sampled one of the nodules and subjected it to a process called "shotgun metagenomics." Instead of searching for a particular DNA signature, shotgun metagenomics takes the approach of simply sampling all the DNA present, just to see what turns up.

To the researchers' surprise, the man did not have tuberculosis. Instead, the bony nodule held the DNA signature of the bacterium Brucella melitensis, the microbe that causes brucellosis.

Brucellosis can be transmitted from livestock to humans in several ways. One possibility is that the man caught the disease from direct contact with animals — perhaps while slaughtering a sheep or delivering a newborn lamb. Or he could have gotten the disease from drinking unpasteurized milk or eating unpasteurized cheese. The Brucella strain that infected the man was a close relative of modern Italian strains, the researchers found, and sheep and goat herding have long histories in the region.

Brucellosis is also called Mediterranean fever. It still affects more than 500,000 people around the world yearly, though livestock vaccination and dairy pasteurization have hampered its spread.

Today, antibiotics are used to treat people with brucellosis, and no more than 2 percent of infected people die from the disease, according to the Centers for Disease Control and Prevention. In its chronic, untreated form, the disease causes muscle and joint pain, fatigue and depression. The deadliest symptom of the disease is endocarditis, the swelling of the lining of the heart.

Read more at Discovery News

Last Terrifying Moments of Baby Mammoths Revealed

The frightening last moments of two baby mammoths that died thousands of years ago are now being revealed, thanks to CT scanning.

The 1- and 2-month-old woolly mammoth calves, which were discovered in different portions of Siberia, choked on mud after falling into water more than 40,000 years ago, new research suggests.

The mud was like a "really thick batter that they got clogged in their trachea and they were unable to dislodge by coughing," said study co-author Daniel Fisher, the director of the University of Michigan Museum of Paleontology. "It basically prevented them from taking them another breath."

Woolly mammoths, close relatives of modern-day elephants, arose about 5.1 million years ago in Africa and went extinct about 10,000 years ago. Though scientists don't know for sure why they disappeared, warming weather and overhunting by humans may have doomed the shaggy beasts. During the last ice age, between 110,000 and 12,000 years ago, however, they roamed throughout Eurasia and North America.

The 1-month-old calf mummy, named Lyuba, was discovered in 2007 by a reindeer herder on the banks of a frozen river on the Yamal Peninsula in Siberia. Lactic acid-producing bacteria had colonized Lyuba's body, essentially "pickling" her and making her unappetizing to would-be scavengers, Fisher said.

A mammoth-ivory hunter found the second mummy, which researchers named Khroma after the river in Yakutia in which she was found, frozen upright in permafrost. Scavengers — possibly Arctic foxes and ravens — devoured Khroma's heart and lungs, as well as parts of the trunk and skull, between the time she was discovered in 2008 and the time scientists could retrieve her body, Fisher said.

Each of the mummies still had a distinctive neonatal line on their teeth, a dark line that forms during birth, because the stress of delivery temporary halts tooth development. By counting the tooth growth layers after the neonatal line, the team estimated that Lyuba was about 1 month old and Khroma 2 months old at death, Fisher said.

The team got permission to perform computed tomography (CT) scanning, as well as some limited dissection of the body.

Lyuba (which means "love" in Russian) was plump and healthy at death.

The scans also revealed that just before death Lyuba had inhaled bits of mud typically found at lake bottoms.

She also had signs of a response called the mammalian dive reflex, reflected in high levels of a mineralized form of iron phosphate in her face and brain tissues. When facial skin and muscles are exposed to cold water, particularly in babies, the body prepares for oxygen loss by shunting more blood circulation from the heart to the brain. This reflex allows the brain to survive longer without oxygen when the body is submerged under water. The iron phosphate formed over the months and years after her death when phosphate leached from her bones and mixed with iron in her blood.

The analysis paints a terrifying picture of Lyuba's last moments. The baby mammoth was likely crossing a frozen lake with her mother when she crashed through the ice and did a "face plant," into the muddy lake bottom, Fisher said.

She then got mud stuck in her airways and tried to blow it out of her trunk. Because the nasal passages narrow in the trunk, she only managed to get the mud stuck even more.

"It moved straight into her trachea and bronchi and by that time she was too exhausted and couldn't clear her airway," Fisher told Live Science. "It was just a matter of minutes before she would have lost consciousness."

Khroma was also healthy when she died, with a belly full of undigested breast milk that looked like fresh yogurt.

Because Khroma was partly eaten, researchers have to do more speculation to understand her death, Fisher said.

Read more at Discovery News

New Dinosaur Was Built Like an Airplane

A new non-avian dinosaur not only looked like a jet but also was an expert flier.

The 125-million-year-old dinosaur, Changyuraptor yangi, strengthens the evidence that flight preceded the origin of birds. The dino, named after researcher Yang Yandong and the Chinese words for “long-feathered raptor,” is described in a study published in the latest issue of Nature Communications.

It's clear that this dinosaur, which sported big wings and a streamlined, aerodynamic body, could fly. The question remains: How did the 4-foot-long animal get off the ground?

“It is difficult to say, and controversial, whether an animal like Changyuraptor was able to take off from the ground or launch from a perch,” project leader Luis Chiappe told Discovery News. “We do know that they were very maneuverable animals and our study shows that they used their tail to slow down while they landed.”

“At a foot in length, the amazing tail feathers of Changyuraptor are by far the longest of any feathered dinosaur,” added Chiappe, a paleontologist at the Natural History Museum of Los Angeles County.

Chiappe and an international team found the dinosaur in the Liaoning Province of northeastern China. Based on multiple recent discoveries there, this site was a hotbed of dino activity back in the Cretaceous, and many of the dinosaurs had feathers.

Changyuraptor looks as if it had four wings instead of the usual two, due to long feathers that jutted out from its legs. Such “four-winged” dinosaurs belonged to a group known as “microraptorine,” or tiny raptors.

Before non-avian dinosaurs went extinct, some of them hunted birds. They also likely ate fish, swooping over bodies of water to catch their dinner. Such moves would have been all the more impressive considering that Changyuraptor weighed 9 pounds. (By comparison, seagulls typically weigh only about 1.5 pounds.)

“The new fossil documents that dinosaur flight was not limited to very small animals, but to dinosaurs of more substantial size,” Chiappe said.

Archaeopteryx, the iconic early bird, lived approximately 150 million years ago. Birds, therefore, were around for just 25 million years before Changyuraptor emerged -- a drop in the proverbial geologic bucket.

Changyuraptor’s precise evolutionary relationship to birds is unclear at the moment, aside from the fact that it appears to have enjoyed eating them.

“Whether the flight capabilities of Changyuraptor and its kin evolved independently to the flight capabilities of birds is controversial,” Chiappe said. “Most likely, some of the aerodynamic features we see in Changyuraptor -- like the large forewings -- are the result of the same evolutionary event.”

Chiappe agrees with other studies concluding that pre- or proto-feathers first evolved for thermoregulation. Feathers then appear to have evolved into larger structures that could have served more than one purpose.

Read more at Discovery News

Jul 14, 2014

Submarine: Any Truth to the Legend?

"The Submarine," an enormous and mythical great white shark that supposedly terrorized South Africans 30 to 44 years ago, might have actually existed, suggest experts who offer logical explanations for some of the extraordinary witness accounts.

Said to be anywhere from 22 to 30 feet long, The Submarine was reported to be in False Bay, South Africa, according to marine biologist Alison Towner of the nearby Dyer Island Conservation Trust. The region is still famous for its large great whites and other sharks.

"During the 1970s to the early 1990s, various anglers fished from small vessels and reported sightings of huge white sharks in False Bay," Towner told Discovery News, adding that some of these individuals later turned to trophy fishing for the sharks before great whites gained protected status in South Africa in 1991.

A few of The Submarine seekers penned popular books, such as Theo Ferreira's "Shark Man: My Obsession with the Great White," which helped to further fuel the legend.

"We caution the reliability of the actual size of this Submarine (shark) as it is actually very difficult to estimate the size of a great white when it is in the water, especially when fighting it on rod and reel as was the case in many accounts of The Submarine," Towner said.

"Further," she continued, "if one is standing on a boat, particularly a smaller boat almost on level with the water, the shark can appear to be much bigger than, for example, (if the person is) standing on a larger elevated vessel."

She and Neil Hammerschlag, a shark expert who has studied great whites in South African waters, told Discovery News that the maximum length great whites can attain is around 20 feet long from snout to upper caudal lobe (tail) tip.

Hammerschlag, a research assistant professor in the Department of Marine Ecosystems and Society at the University of Miami, added that there is no truth to reports of great whites reaching 30 feet in length or more.

John McCosker, chair of Aquatic Biology at the California Academy of Sciences, said that a shark caught in waters off of Cojimar, Cuba, in 1945 supposedly was 21'3" long. It was never accurately weighed or measured, although McCosker saw a tooth removed from this shark’s jaw, and he said it could have come from a 21 footer, as described.

Yet another great white, found near Kangaroo Island in South Australia, purportedly was around 22 feet long, but only its head and pectoral fin were saved. McCosker said he has seen white sharks "that are at least 18 feet long off Dangerous Reef, South Africa."

He doubts that a great white could grow much larger than those sizes, or weigh more than 3 to 4 tons.

"The problem becomes one of maneuverability," he explained. "A shark that large has great difficulty capturing live prey and would have to survive by eating large mammal carcasses."

The largest sharks, such as basking sharks and whale sharks, tend to be more gentle and passive filter feeders. Whale sharks can grow up to around 41.5 feet long.

"When sharks become as large as that, they can only survive by filter feeding, like the great whales, which are the largest mammals on earth," McCosker said.

Read more at Discovery News

Ancient Coins Found Buried in British Cave

Digging through a cave in central Britain, archaeologists uncovered 26 ancient gold and silver coins belonging to the Corieltauvi tribe, a group of people that lived in Britain before the Roman conquest.

Archaeologists previously found collections of coins like these in other parts of Britain, but this is the first time they have ever been discovered buried in a cave. The discovery of the coins was a surprise, because they were found at a site called Reynard's Kitchen Cave, which is located outside the Corieltauvi's usual turf.

"It might be that we have a member of the tribe living beyond the boundary that is more usually associated with the territory," Rachael Hall, an archaeologist at the National Trust who led the excavation, told Live Science in an email.

Back in 2000, a group of almost 5,000 Corieltauvi coins were discovered in Leicestershire. This more recent find at Reynard's Kitchen Cave might be additional evidence that members of the tribe once hoarded coins. Hall and the team speculate that the coins were hidden to ensure they weren't stolen, and whoever buried them may have planned on returning to the site to dig the coins up again.

The discovery included 20 Iron Age coins, three Roman coins and three coins from much later eras, according to a treasury report prepared by Ian Leins, curator of Iron Age and Roman coins at the British Museum. While the coins are not all from the same time period, Hall and the team of archaeologists said it's common to find collections of coins from different times, in the same way that, for example, U.S. coins from earlier decades are still circulating among newer coins.

Archaeologists are still unsure how Iron Age coins were used, but it is unlikely they were used as money to purchase items. They were more likely used as a means for storing wealth, given as gifts or offered as sacrifice. The three Roman coins discovered predate the Roman invasion, so archaeologists believe the coins may have been given as gifts.

A climber seeking shelter in the cave first discovered four of the coins, which prompted a full-scale excavation by the National Trust and Operation Nightingale, a group that helps injured military members recuperate by having them perform field archaeology.

Read more at Discovery News

Road Melts from Yellowstone Volcano's Heat

Yellowstone National Park closed a popular road Thursday (July 10) after geothermal heat cooked the asphalt.

Part of Firehole Lake Drive, a scenic one-way road off of Yellowstone's main loop, was shut down for repairs when oil bubbled to the surface, damaging the blacktop, the Park Service said in a statement. The closure doesn't affect the Grand Loop Road, which sees 20,000 visitors per day during the summer.

Park spokesman Dan Hottle told Live Science that Firehole Lake Drive's surface hit 160 degrees Fahrenheit (70 degrees Celsius) on Thursday, about 30 degrees to 40 degrees F (17 to 22 degrees C) hotter than usual.

Geothermal heat radiating from Yellowstone's underground supervolcano, combined with warming from the summer sun, softened the 3.3-mile-long (5.3 kilometers) road.

Hottle noted that the road problems do not mean the volcano is showing signs of an impending eruption. "The supervolcano is not going to blow," he said.

Road closures from heat damage aren't unusual in Yellowstone, which has more than 10,000 geothermal features and 500 geysers. The park has previously closed Firehole Lake Drive for repairs due to heat damage, Hottle said. "This road has had this particular issue in the past, but it doesn't happen too often," he said.

The Park Service plans to work on repairs through the weekend, and hopes to reopen the road by early next week, Hottle said.

Within the next five years, the Park Service also plans to relocate a part of Grand Loop Road that takes visitors past Frying Pan Spring. "That area of the road is always buckled up and being repatched and repaired, so we're moving it away from the thermal area," Hottle said.

From Discovery News

Brain-Eating Amoeba Thrives in Warm, Fresh Water

The brain-eating amoeba that killed a 9-year-old Kansas girl last week is an organism that thrives in warm fresh water and can be found in lakes, rivers, hot springs and soil, according to the Centers for Disease Control and Prevention.

The victim, Hally "Bug" Nicole Yust, reportedly had swum in several lakes over the past few weeks near her home in Spring Hill. The Kansas Department of Health confirmed that she died from primary amoebic meningoencephalitis (PAM) caused by the amoeba, Naegleria fowleri, which she likely inadvertently inhaled via lake water.

"Once forced up the nose, it can travel to the brain, where it digests brain cells," Jonathan Yoder, an epidemiologist at the Centers for Disease Control and Prevention, told Discovery News. "It's a very tragic disease that thankfully is very rare."

Aside from its rarity, the amoeba "is not looking to prey upon human victims," he said. "They usually go after bacteria in water and soil."

As single-celled organisms, amoebas do not even have brains.

However, Naegleria species, including this disease-causing one, can transform themselves into three different basic "body" types.

"This one-celled organism hunts and eats bacteria as an amoeba, swims around looking for a better environment as a flagellate, and then hunkers down and waits for good times as a cyst," said Simon Prochnik, a computational scientist at the U.S. Department of Energy's Joint Genome Institute. "It is a very rare process to go from amoeba to flagellate like this."

Prochnik, who sequenced the genome of a Naegleria species, explained that when environmental conditions are not favorable, the "stressed" amoeba can quickly grow two tails, transforming it into the flagellate. It can then swim and move around to a better spot, similar to the way that human sperm travel.

To support these three body or "personality" types, as Prochnik calls them, the organism is packed with genes: 15,727 of them. To put that into perspective, humans have 23,000 protein-coding genes.

Since the creature is so versatile, it can lurk in warm, moist places for extended periods.

Two Louisiana residents contracted the amoeba a few years ago after using a neti pot, which looks like a teapot and is used for nasal irrigation to relieve sinus problems. The CDC determined that the organism was living in the victims' home water system systems. The individuals apparently did not boil the water before placing it in the neti pots.

Yoder said it is important to follow the directions included with neti pots. The instructions usually mention that users should put distilled, boiled water in them and not just water right out of the tap.

If users don't follow these instructions, there is a slim chance they too might get the disease caused by Naegleria fowleri.

According to CDC data, the fatality rate is over 97 percent. Only three people out of 132 known infected individuals in the United States from 1962 to 2013 have survived.

Diagnosing this disease is difficult. Yoder explained that associated symptoms, such as high fever, headache, and stiff neck, are present with bacterial and viral meningitis, so misdiagnoses are possible.

The Kansas Department of Health and Environment reports, however, that the infection is rare and that Yust was only the second known case of a person contracting the infection in Kansas. The state will likely issue warnings to recreational water users, as other states like Florida have done following similar deaths.

Read more at Discovery News

Earliest War Victims Lived Brutal Lives

Sometimes, old bones have new stories to tell.

A collection of skeletons from 13,000 years ago, recovered from the east bank of the Nile river in the 1960s, are revealing what could be the oldest known victims of a war, according to news reports.

The skeletons are marked with slashes, embedded metal shards and bone breaks from what experts say were unmistakably arrowheads, some lashed to the top of long-decayed wooden poles. The injuries were gruesome.

Renee Friedman, curator of the British Museum's new Early Egypt exhibit, told The Guardian newspaper: "Often with remains from such an ancient time, we will never know what happened to them. With these skeletons there is no question: we found arrow heads lodged in spines, spear points that had pierced eye sockets, and many that clearly died under a hail of arrows. The lives and deaths of these people were not nice."

Among the skeletons were many women and children, which shows that the times they lived in were brutal. Experts think that resources were scarce in the area, which was cold and dry with little fertile land.

The region was in the throes of abrupt climate change 13,000 years ago, in a period called The Younger Dryas. During that time, Earth's climate began a shift to a warmer period from a cold, glacial world.

But in the midst of that warming, melting glaciers cooled the North Atlantic Ocean and land temperatures suddenly plunged, according to the National Climactic Data Center (NOAA).

Toward the end of The Younger Dryas, land temperatures shot up again -- 18 degrees Farenheit (10 Celcius) in a decade, NOAA said.

Read more at Discovery News