Enormous Prehistoric Camel Roamed Arctic

Remains of an extinct, giant camel have been unearthed not in a desert, but in the High Arctic, according to a Nature Communications report.

It’s the furthest north camel remains have ever been found and this one was on Ellesmere Island. The camel was also likely at least 30 percent bigger than camels are today. If you think of that in human terms, it would be roughly like an average-sized man standing about 8 feet tall, so these were some big camels.

“These bones represent the first evidence of camels living in the High Arctic region,” co-author Natalia Rybczynski of the Canadian Museum of Nature was quoted as saying in a press release. “It extends the previous range of camels in North America northward by about 1,200 km (746 miles), and suggests that the lineage that gave rise to modern camels may have been originally adapted to living in an Arctic forest environment.”

This particular camel, which was a close relative of a fossil genus called Paracamelus, lived 3.5 million years ago, but camels in general originated about 45 million years ago during the mid-Eocene Period in North America. They dispersed to Eurasia by 7 million years ago using the Bering land bridge that joined what is now Alaska to Russia.

It’s interesting to consider their history, as today we associate camels with desert environments and places like Egypt.

The Arctic camel instead lived in a boreal-type forest. What is now the Arctic was significantly warmer 3.5 million years ago. For example, it had temperatures that were chilly, but not ultra freezing cold. (Other researchers are studying such past climates to better understand present global warming, but the human effects on climate now are unprecedented.)

The discovery of the ancient camel could help to explain how camels evolved some of their distinctive physical characteristics.

Read more at Discovery News

Gnarly Mummy Head Reveals Medieval Science

In the second century, an ethnically Greek Roman named Galen became doctor to the gladiators. His glimpses into the human body via these warriors' wounds, combined with much more systematic dissections of animals, became the basis of Islamic and European medicine for centuries.

Galen's texts wouldn't be challenged for anatomical supremacy until the Renaissance, when human dissections —- often in public -— surged in popularity. But doctors in medieval Europe weren't as idle as it may seem, as a new analysis of the oldest-known preserved human dissection in Europe reveals.

The gruesome specimen, now in a private collection, consists of a human head and shoulders with the top of the skull and brain removed. Rodent nibbles and insect larvae trails mar the face. The arteries are filled with a red "metal wax" compound that helped preserve the body.

The preparation of the specimen was surprisingly advanced. Radiocarbon dating puts the age of the body between A.D. 1200 and A.D.1280, an era once considered part of Europe's anti-scientific "Dark Ages." In fact, said study researcher Philippe Charlier, a physician and forensic scientist at University Hospital R. Poincare in France, the new specimen suggests surprising anatomical expertise during this time period.

"It's state-of-the-art," Charlier told LiveScience. "I suppose that the preparator did not do this just one time, but several times, to be so good at this."

Myths of the middle ages

Historians in the 1800s referred to the Dark Ages as a time of illiteracy and barbarianism, generally pinpointing the time period as between the fall of the Roman Empire and somewhere in the Middle Ages. To some, the Dark Ages didn't end until the 1400s, at the advent of the Renaissance.

But modern historians see the Middle Ages quite differently. That's because continued scholarship has found that the medieval period wasn't so ignorant after all.

"There was considerable scientific progress in the later Middle Ages, in particular from the 13th century onward," said James Hannam, an historian and author of "The Genesis of Science: How the Christian Middle Ages Launched the Scientific Revolution" (Regnery Publishing, 2011).

For centuries, the advancements of the Middle Ages were forgotten, Hannam told LiveScience. In the 16th and 17th centuries, it became an "intellectual fad," he said, for thinkers to cite ancient Greek and Roman sources rather than scientists of the Middle Ages. In some cases, this involved straight-up fudging. Renaissance mathematician Copernicus, for example, took some of his thinking on the motion of the Earth from Jean Buridan, a French priest who lived between about 1300 and 1358, Hannam said. But Copernicus credited the ancient Roman poet Virgil as his inspiration.

Much of this selective memory stemmed from anti-Catholic feelings by Protestants, who split from the church in the 1500s.

As a result, "there was lots of propaganda about how the Catholic Church had been holding back human progress, and it was great that we were all Protestants now," Hannam said.

Anatomical dark ages?

From this anti-Catholic sentiment arose a great many myths, such as the idea that everyone believed the world to be flat until Christopher Columbus sailed to the Americas. ("They thought nothing of the sort," Hannam said.)

Similarly, Renaissance propagandists spread the rumor that the Medieval Christian church banned autopsy and human dissection, holding back medical progress.

In fact, Hannam said, many societies have banned or limited the carving up of human corpses, from the ancient Greeks and Romans to early Europeans (that's why Galen was stuck dissecting animals and peering into gladiator wounds). But autopsies and dissection were not under a blanket church ban in the Middle Ages. In fact, the church sometimes ordered autopsies, often for the purpose of looking for signs of holiness in the body of a supposedly saintly person.

The first example of one of these "holy autopsies" came in 1308, when nuns conducted a dissection of the body of Chiara of Montefalco, an abbess who would be canonized as a saint in 1881. The nuns reported finding a tiny crucifix in the abbess' heart, as well as three gallstones in her gallbladder, which they saw as symbolic of the Holy Trinity.

Other autopsies were entirely secular. In 1286, an Italian physician conducted autopsies in order to pinpoint the origin of an epidemic, according to Charlier and his colleagues.

Some of the belief that the church frowned on autopsies may have come from a misinterpretation of a papal edict from 1299, in which the Pope forbade the boiling of the bones of dead Crusaders. That practice ensured Crusaders' bones could be shipped back home for burial, but the Pope declared the soldiers should be buried where they fell.

"That was interpreted in the 19th century as actually being a stricture against human dissection, which would have surprised the Pope," Hannam said.

Well-studied head

While more investigation of the body was going on in the Middle Ages than previously realized, the 1200s remain the "dark ages" in the sense that little is known about human anatomical dissections during this time period, Charlier said. When he and his colleagues began examining the head-and-shoulders specimen, they suspected it would be from the 1400s or 1500s.

"We did not think it was so antique," Charlier said.

But radiocarbon dating put the specimen firmly in the 1200s, making it the oldest European anatomical preparation known. Most surprisingly, Charlier said, the veins and arteries are filled with a mixture of beeswax, lime and cinnabar mercury. This would have helped preserve the body as well as give the circulatory system some color, as cinnabar mercury has a red tint.

Thus, the man's body was not simply dissected and tossed away; it was preserved, possibly for continued medical education, Charlier said. The man's identity, however, is forever lost. He could have been a prisoner, an institutionalized person, or perhaps a pauper whose body was never claimed, the researchers write this month in the journal Archives of Medical Science.

Read more at Discovery News

Why First 30 Hours Critical for Killing HIV

News that a baby seems to have been functionally cured of HIV after early intervention has piqued the interest of the medical community worldwide and raised hopes that the procedure could be used to more easily and effectively prevent mother-to-child transmission of the virus. More than 3 million children are currently living with the virus that causes AIDS.

Doctors made the announcement Sunday at the 20th annual Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta.

The timing of the intervention -- about 30 hours after the baby was born -- may have been the key to success, doctors involved with the case said.

“Early treatment most likely contributed to the outcome of this child, but whether it's the only intervention that allowed this outcome is unclear and requires further study,” said Deborah Persaud, associate professor at Johns Hopkins Children’s Center and author of the report on the baby.

The current procedure for high-risk infants is a regimen of smaller doses of antiretroviral drugs until a blood test confirms HIV when the baby is six weeks old. But knowing that this baby was at high risk, Dr. Hannah Gay decided not to wait for the results, and started the baby on high doses of three standard drugs used for HIV-positive babies as soon as the baby was transferred to her at the University of Mississippi Medical Center. The child is now 2 ½ and has no signs of the functioning virus.

While pediatric AIDS researchers were surprised, and while they reiterate the need for the procedure to be repeated, they said it makes sense that the treatment worked. Persaud offered one hypothesis that she and Dr. Katherine Luzuriaga, an immunologist at the University of Massachusetts, plan on testing in clinical trials in the next few months: The HIV virus usually establishes itself in reservoirs where it stays in a dormant state.

“One can imagine if you can halt virus replication very quickly in an infant through the use of very early antiviral therapy,” Persaud said, “that what we've accomplished with this is that the reservoirs are not given the opportunity to be established.

Researchers suspect that those viral reservoirs might be different in children than in adults, Luzuriaga added.

“If we start early, we appear to be able to control viral replication extra tightly and we end up with lower amounts of the viral reservoir,” Luzuriaga said.

Early detection and treatment of diseases is something Dr. Josh Petrikin is familiar with as a neonatologist at Children’s Mercy Hospital in Kansas City, Missouri.

“Depending on the diagnosis, it can be critical -- even life-saving” to start treatment early for a variety of diseases, he said.

All babies in the U.S. get some form of newborn screen, testing for up to 70 various diseases and conditions depending on the state -- nearly all of which can be affected by an early diagnosis. HIV isn’t included on the screen, but the American College of Obstetricians and Gynecologists recommends screening for pregnant women. In the future, genomic medicine could replace the current screening protocol, Petrikin said. Like many others, he’ll be watching for published work on the potential HIV cure.

Read more at Discovery News

Mystery SETI Signal Set Rules of Engagement

In the Fall of 1967, a small team of radio astronomers came face-to-face with a profound mystery that they didn’t want to be true.

At one point they half-seriously thought about destroying the data and staying stone silent. That’s because announcing it to the world could open a Pandora’s box for science, and derail at least one astronomer’s PhD thesis.

A small group of radio astronomers in the United Kingdom had stumbled upon clock-precision radio pulses coming from deep space. The signal was unlike anything ever seen before or even predicted in astronomy. In the absence of a natural explanation, the researchers pondered, for three long weeks, whether this was really a “hello” from an extraterrestrial civilization.

The team faced a cultural black hole with regard to the public response. How do you verify the signal? How do you announce it to the world? Do you send a reply to the stars, or is that too dangerous?

As is the case in our compulsive universe, nature was cleverer than imagined. This story of mistaken identity, as recently researched by Alan Penny of the University of St. Andrews, set the stage for preparing a SETI protocol for how to announce the discovery of the real deal sometime in the future.

Little Green Men

In July 1967, a novel long-wavelength radio telescope, the largest of its time, began operations at the Mullard Radio Astronomy Observatory in Lord’s Bridge, Cambridgeshire, U.K.

Antony Hewish built the array to study radio emissions from quasars, a very distant, energetic and utterly mysterious newly discovered class of object (today we know they are the black hole powered cores of active galaxies). Graduate student Jocelyn Bell took home a 98-foot long paper strip chart of the telescope’s observations (this was a time before microcomputers and wide use of digital data processing and storage by astronomers).

While marking up the chart in her attic, she noticed a peculiar source that was flickering like a police car strobe light. As any good scientist would do, she checked for instrument noise, malfunction or man made clutter. (In 1963 the all-sky glow of the cosmic microwave background was first suspected to be radio contamination from pigeon droppings in a radio communications antenna.)

Bell realized that the source moved with the Earth’s rotation. The source really is in the sky and somewhere out there in the galaxy!

The telescope’s builder, Hewish, was intrigued and installed a faster strip recorder. The ghostly source reappeared in On Nov. 28 and the astronomers recorded pulses that lasted a fraction of a second but recurred precisely every 1.3 seconds. The eye-opener was that the pulses were so short in duration that they had be coming from something smaller than a few thousand miles across. This might place the source on an Earth-sized planet rather than a star!

What’s more, the unusually narrow frequency of the signal mimicked the signature of man made radar transmissions.

In the absence of a physical explanation, the astronomers toyed with the possibility that the signal could be coming from an alien civilization.

The planet hypothesis was easily testable. If the source was orbiting a star, the signals should show a rhythmic frequency shift as the planet approached and then receded from us along a racetrack orbit. This is the high water mark in the team’s taking the E.T. hypothesis seriously. As far back as September, the phenomenon was nicknamed LGM for Little Green Men (just as spurious mechanical malfunctions are dismissed as “gremlins”).

What if a planet’s motion was detected? Should the British government be alerted to hold a press conference announcing something so momentous as an “hello” from space aliens? Or should the data be trashed in favor of protecting Earth from being tempted to talk to E.T.? What if a hostile, invading civilization was “fishing” across interstellar space for a response to their beacon?

By the end of December, the LGM hypothesis quickly evaporated after astronomers learned the source is not orbiting anything.

The final nail in the coffin came when a second, and then a third pulsating source was found in December. It is very improbable that civilizations at three different stars widely separated in space and time should be simultaneously targeting us at exactly the same radio frequencies.

Finally, in February 1968, Hewish published a paper in the journal Nature that described the phenomena as a signal from a neutron star — the crushed remnant of a massive star.

The details of the mechanism were not then known — only later astrophysicists described the signal as being a rotating beacon of radiation from the whirling neutron star, or pulsar.

In late 1968, a different team identified the pulsar as being in the center of the Crab Nebula, a supernova remnant (shown at top).

Dress Rehearsal

This story offer parallels to what might happen when astronomers someday stumble across real evidence for E.T.

The SETI folks have set up and published a protocol for how the receipt of an artificial signal would be confirmed and then openly announced to the world. But as with the pulsars, a strange phenomenon may appear when a new window on the universe opens up.

This could, perhaps, be some kind of future neutrino telescope, or a gravity wave detector. A non-SETI team of researchers could pick up a signal that cannot be explained by any known phenomena. It could take years to rule out any imaginable astrophysical processes.

Meanwhile, in the age of the Internet and social media, I think rumor and speculation would spread vastly faster than it could in 1967. Such a detection could not remain as tightly under wraps as it did back then.

Read more at Discovery News

Nature's Blockbuster Identity Thieves

The Serpent and the Rainbow Coloration

Two movies at the top of the U.S. box office charts, "Snitch" and "Identity Thief," involve people taking on false identities. Faking out predators and prey by mimicking another specie has been a plot line in nature for millions of years.

A dangerous example of look-alike animals is the copy-cat coloration of the harmless Mexican milk snake (Lampropeltis triangulum annulata, left) and highly venomous Texas coral snake (Micrurus tener, inset). The two species look similar, inhabit the same areas and even share a taste for dining on their fellow serpents. However, although the docile milk snakes are common pets, the coral snake is a relative of the cobras and injects a potent nerve venom, or neurotoxin, with its bite.

How can herpetologist avoid a deadly case of mistaken identity? Both snakes have a combination of red, black and yellow bands, but in a different order. The rhyme, “Red next to yellow, kill a fellow...red next to black, poison lack,” accurately describes the difference in coloration and danger of the two species.

Predators don't have humans' skill at remembering life-saving rhymes, so they tend to avoid both reptiles. This type of mimicry, called Batesian, allows a harmless species to bluff their way to survival. The odd thing is, in this case, how could a predator ever learn to avoid red, black and yellow banded serpents if the coral snakes killed any predator that tried to make a meal of them?

Evolution may have embedded the fear of coral snakes in some predators. An experiment published in Science found that some birds will instinctively avoid red-and-yellow ring patterns, although they will readily attack red-and-yellow stripes or green-and-blue rings. Birds aren't the only animals leery of serpents. Primates, including humans, seem to have evolved an ability to rapidly develop a fear response to snakes, according to numerous studies. However, these instinctual fears can be overcome by conditioning or, in the case of humans, education.

All the King's Butterflies

 For both monarch (right) and viceroy (inset) butterflies, it's good to be the king. Monarch butterflies (Danaus plexippus) dine on milkweeds and store up toxins from the plants, making the insects foul tasting to birds. The viceroy (Limenitis archippus) was once thought to be a non-toxic usurper of the monarch's unpalatable crown, but it turns out that the viceroy can be just as noxious, according to research published in Nature.

This kind of mimicry, called Müllerian mimicry, allows both butterflies to benefit from each other's nasty flavor.

Both kings of the insect world wear orange and black robes, although regional variations of the viceroy butterfly have adapted their garments to match the monarch relative holding court nearby. In Florida, viceroys coloration matches that of the queen butterfly (Danaus gilippus) whereas in Mexico, viceroys mimic the coloration of the soldier butterfly (Danaus eresimus).

Where Hawks Dare

The vultures wheeling overhead were of little concern to the rodents scurrying from rock to rock, until suddenly one of the birds broke from the slowly circling flock and dove from the sky.

The hapless mouse now in the talons of that bird learned too late that that was no vulture. That was a zone-tailed hawk (Buteo albonotatus).

From the ground, the silhouette of the hawk (right) resembles that of a turkey vulture (Cathartes aura, left). The hawk even hold its wings like a vulture and flies along with vulture flocks. But, the two birds differ in their feeding preferences. Vultures rarely eat live prey, so small animals have little to fear from them. The hawk, on the other hand, eats any small animal it can get its claws on.

Read more at Discovery News

Dark Fantasies: When They Cross the Line

The cannibal cop case of Officer Gilberto Valle continues to dredge up gruesome details of what prosecutors allege was the 28-year-old’s plan to abduct and eat women. The defense’s response? It was pure fantasy.

While the details are disturbing, so too is the idea of “thought police." Where, exactly, does U.S. law draw the line between fantasy (no matter how dark) and conspiracy?

“In this country, it is a crime to conspire to commit a crime,” said Joe DeMarco, an Internet lawyer and former head of the cyber crimes unit at the U.S. Attorney’s Office in New York. “So, if we agreed to buy a kilo of cocaine and break it up into little bags and sell it, even if we never did it, it’s a conspiracy that violates the narcotics laws of the U.S., and we could go to jail for years and years...We like to stop a crime before it happens.”

But, criminal law doesn’t go after fantasies, said Marcus Asner, partner at Arnold and Porter, a New York law firm, and former chief of the major crimes unit at the U.S. Attorney’s Office in Manhattan. Criminal law separates between actus reus and mens rea, Latin terms meaning guilty act and guilty mind, allowing some leeway in guilty thoughts -- meaning that almost all defendants argue they were simply pretending.

“Suppose you’re at a target range and you don’t realize someone is behind the target, you pull the trigger and someone accidentally gets killed. In that case, you’re not guilty,” Asner said. “It was an accident. On the other hand, if you are shooting at something thinking it is a person, and you intend to kill a person, but in fact the person is not there and no one gets killed, there is no completed crime -- but we call that attempt and attempt is a crime.”

In reality, though, it’s blurry, he said. One key question that often helps define cases is whether the defendant took a substantial step toward the crime.

Take a case he argued in 2005, U.S. vs. Joseph Zito. Zito often got online to look for young girls, and eventually, he started chatting with an FBI agent he believed to be a young girl.

“The government figures out who he is but doesn’t arrest him until he gets in the car and shows up to meet the girl with sex paraphernalia in the trunk of his car,” Asner said. “We were very careful to make sure the guy did take a substantial step.”

One of the arguments against Valle is the specificity he used in his communication.

“This is someone who hasn’t just idly talked about cannibalism, but he’s named specific people,” DeMarco said.

Further complicating the “I was just pretending” defense is the Internet.

“The Internet allows people who have these niche interests to find each other in ways that are efficient, global, and, if you want, anonymous,” DeMarco said. “It enables people with disparate interests -- whether it be stamp collecting or cannibalism -- to find each other. And that can validate their interest, so they don’t feel alone or odd or unusual.”

Read more at Discovery News

In a First, Baby 'Cured' of HIV

Researchers say they have, for the first time, cured a baby born with HIV -- a development that could help improve treatment of babies infected at birth.

There is an important technical nuance: researchers insist on calling it a "functional cure" rather than a complete cure.

That is because the virus is not totally eradicated. Still, its presence is reduced to such a low level that a body can control it without the need for standard drug treatment.

The only fully cured AIDS patient recognized worldwide is the so-called "Berlin patient," American Timothy Brown. He is considered cured of HIV and leukemia five years after receiving bone marrow transplants from a rare donor naturally resistant to HIV. The marrow transplant was aimed at treating his leukemia.

But in this new case, the baby girl received nothing more invasive or complex than commonly available antiretroviral drugs. The difference, however, was the dosage and the timing: starting less than 30 hours after her birth.

It is that kind of aggressive treatment that likely yielded the "functional cure," researchers reported Sunday at the 20th annual Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta, Georgia.

What researchers call dormant HIV-infected cells often re-start infections in HIV-infected patients within a few weeks after antiretroviral treatment stops, forcing most people who have tested HIV-positive to stay on the drugs for life or risk the illness progressing.

"Prompt antiviral therapy in newborns that begins within days of exposure may help infants clear the virus and achieve long-term remission without lifelong treatment by preventing such viral hideouts from forming in the first place," said lead researcher Deborah Persaud, of Johns Hopkins Children's Center in Baltimore, Maryland.

It appears to be the first time this was achieved in a baby, she said.

The baby was infected by her HIV-positive mother, and her treatment with therapeutic doses of antiretroviral drugs began even before her own positive blood test came back.

The typical protocol for high-risk newborns is to give them smaller doses of the drugs until results from an HIV blood test is available at six weeks old.

Tests showed the baby's viral count steadily declined until it could not longer be detected 29 days after her birth.

The child was given follow-up treatment with antiretrovirals until 18 months, at which point doctors lost contact with her for 10 months. During that period she was not taking antiretrovirals.

Researchers then were able to do a series of blood tests -- and none gave an HIV-positive result.

Natural viral suppression without treatment is an exceedingly rare occurrence, seen in fewer than half a percent of HIV-infected adults, known as "elite controllers," whose immune systems are able to rein in viral replication and keep the virus at clinically undetectable levels.

Experts on HIV have long wanted to help all HIV patients achieve elite-controller status. Researchers say this new case offers hope as a game-changer, because it suggests prompt antiretroviral therapy in newborns indeed can do that.

Still, they said, their first priority is learning how to stop transmission of the virus from mother to newborn. ARV treatments of mothers currently stop transmission to newborns in 98 percent of cases, they say.

Read more at Discovery News

ADHD Doesn't Go Away

Picture someone with attention deficit hyperactivity disorder, or ADHD, and you probably conjure up an image of an elementary school-age boy. But an analysis of data from the first large, population-based study to follow kids through to adulthood shows that the neurobehavioral disorder rarely goes away with age.

Indeed, as ADHD patients make the transition to adulthood, the issues they face often multiply: they are more likely to have other psychiatric disorders and even commit suicide, reports a new study published online today in Pediatrics.

In fact, researchers found that only 37.5 percent of the adults who had been diagnosed with the disorder as a child were free of other psychiatric disorders, including alcohol and drug dependence, in their late 20s.

Very few of the children with ADHD were still being treated as adults -- although neuropsychiatric interviews confirmed that 29 percent still had it.

“I think there has been a view that ADHD is a childhood disorder, and it’s only relatively recently that people have been trained to detect it in adults,” said Nathan Blum, a developmental-behavioral pediatrician at Children’s Hospital in Philadelphia, who was not involved in the study.

Among the adults who’d had ADHD as a child, 57 percent had at least one other psychiatric disorder, compared with 35 percent of the controls. Just under 2 percent percent had died; of the seven deaths, three were suicides. Of the controls, less than 1 percent had died. Of those 37 deaths, five were from suicide. And 2.7 percent were incarcerated at the time of recruitment for the study.

“It’s deeply concerning and indicative of the nature and severity of the condition,” said study author Dr. William Barbaresi of Boston Children’s Hospital. “ADHD tends to be trivialized still. (These statistics) are a direct indicator of why we have to pay attention to it and its associated conditions.”

ADHD affects about 7 percent of all children. This study followed all children in Rochester, Minn., born between 1976 and 1982, and whose families allowed access to medical records. Of those 5,718 kids, 367 were diagnosed with ADHD.

The analysis of the data is ongoing; the authors have published previous reports on long-term school outcomes and health care costs of childhood cases of ADHD, among many others. And because the population of Rochester, home to the Mayo Clinic, is largely white and middle-class, researchers believe the outcomes may be more troubling if a more diverse group were studied.

Plus, the 37.5 percent who were still alive, not in jail, and free of other psychiatric disorders weren’t necessarily leading blissful lives.

The analysis published today did not look for a host of other issues associated with adult ADHD, such as job retention, performance, and long-term relationship status, Barbaresi said. That’s still to be analyzed. Other forthcoming studies might parse out the difference in adult outcomes in kids who had been treated for ADHD, vs. those who hadn’t.

Adult treatment of ADHD can be effective, Barbaresi said, but it’s more complicated than treating a child. Most children, he said, gradually stop taking stimulant medication.

“If an adult comes to a physician at age 30 having had childhood ADHD, wondering whether or not it’s still an issue because they’re facing, it’s much more challenging because they likely have other issues by then as well, other mental health problems or substance abuse issues,” Barbaresi said. “A doctor would be reluctant to prescribe stimulant medication to someone who has another mental health problem.”

And while stimulant medications can be timed so that a child can function during a school day, there are limitations for adults, Blum said. The medication starts working shortly after taking it, and then wears off. 24-hour meds are less effective.

“We need to start building a treatment model that treats it as a chronic illness like diabetes, and work from the beginning to keep kids in treatment,” Barbaresi said. “I hope this will be a wake-up call about the need to rethink this condition and to stop the sensationalist perspectives of focusing on the evils of stimulant medications.”

Read more at Discovery News

Short Algorithm, Long-Range Consequences

In the last decade, theoretical computer science has seen remarkable progress on the problem of solving graph Laplacians -- the esoteric name for a calculation with hordes of familiar applications in scheduling, image processing, online product recommendation, network analysis, and scientific computing, to name just a few. Only in 2004 did researchers first propose an algorithm that solved graph Laplacians in "nearly linear time," meaning that the algorithm's running time didn't increase exponentially with the size of the problem.

At this year's ACM Symposium on the Theory of Computing, MIT researchers will present a new algorithm for solving graph Laplacians that is not only faster than its predecessors, but also drastically simpler. "The 2004 paper required fundamental innovations in multiple branches of mathematics and computer science, but it ended up being split into three papers that I think were 130 pages in aggregate," says Jonathan Kelner, an associate professor of applied mathematics at MIT who led the new research. "We were able to replace it with something that would fit on a blackboard."

The MIT researchers -- Kelner; Lorenzo Orecchia, an instructor in applied mathematics; and Kelner's students Aaron Sidford and Zeyuan Zhu -- believe that the simplicity of their algorithm should make it both faster and easier to implement in software than its predecessors. But just as important is the simplicity of their conceptual analysis, which, they argue, should make their result much easier to generalize to other contexts.

Overcoming resistance

A graph Laplacian is a matrix -- a big grid of numbers -- that describes a graph, a mathematical abstraction common in computer science. A graph is any collection of nodes, usually depicted as circles, and edges, depicted as lines that connect the nodes. In a logistics problem, the nodes might represent tasks to be performed, while in an online recommendation engine, they might represent titles of movies.

In many graphs, the edges are "weighted," meaning that they have different numbers associated with them. Those numbers could represent the cost -- in time, money or energy -- of moving from one step to another in a complex logistical operation, or they could represent the strength of the correlations between the movie preferences of customers of an online video service.

The Laplacian of a graph describes the weights between all the edges, but it can also be interpreted as a series of linear equations. Solving those equations is crucial to many techniques for analyzing graphs.

One intuitive way to think about graph Laplacians is to imagine the graph as a big electrical circuit and the edges as resistors. The weights of the edges describe the resistance of the resistors; solving the Laplacian tells you how much current would flow between any two points in the graph.

Earlier approaches to solving graph Laplacians considered a series of ever-simpler approximations of the graph of interest. Solving the simplest provided a good approximation of the next simplest, which provided a good approximation of the next simplest, and so on. But the rules for constructing the sequence of graphs could get very complex, and proving that the solution of the simplest was a good approximation of the most complex required considerable mathematical ingenuity.

Looping back

The MIT researchers' approach is much more straightforward. The first thing they do is find a "spanning tree" for the graph. A tree is a particular kind of graph that has no closed loops. A family tree is a familiar example; there, a loop might mean that someone was both parent and sibling to the same person. A spanning tree of a graph is a tree that touches all of the graph's nodes but dispenses with the edges that create loops. Efficient algorithms for constructing spanning trees are well established.

The spanning tree in hand, the MIT algorithm then adds back just one of the missing edges, creating a loop. A loop means that two nodes are connected by two different paths; on the circuit analogy, the voltage would have to be the same across both paths. So the algorithm sticks in values for current flow that balance the loop. Then it adds back another missing edge and rebalances.

In even a simple graph, values that balance one loop could imbalance another one. But the MIT researchers showed that, remarkably, this simple, repetitive process of adding edges and rebalancing will converge on the solution of the graph Laplacian. Nor did the demonstration of that convergence require sophisticated mathematics: "Once you find the right way of thinking about the problem, everything just falls into place," Kelner explains.

Paradigm shift
Daniel Spielman, a professor of applied mathematics and computer science at Yale University, was Kelner's thesis advisor and one of two co-authors of the 2004 paper. According to Spielman, his algorithm solved Laplacians in nearly linear time "on problems of astronomical size that you will never ever encounter unless it's a much bigger universe than we know. Jon and colleagues' algorithm is actually a practical one."

Spielman points out that in 2010, researchers at Carnegie Mellon University also presented a practical algorithm for solving Laplacians. Theoretical analysis shows that the MIT algorithm should be somewhat faster, but "the strange reality of all these things is, you do a lot of analysis to make sure that everything works, but you sometimes get unusually lucky, or unusually unlucky, when you implement them. So we'll have to wait to see which really is the case."

Read more at Science Daily

Misplaced Molecules: New Insights Into the Causes of Dementia

A shortage of a protein called TDP-43 caused muscle wasting and stunted nerve cells. This finding supports the idea that malfunction of this protein plays a decisive role in ALS and FTD. The study is published in the Proceedings of the National Academy of Sciences (PNAS).

ALS is an incurable neurological disease which manifests as rapidly progressing muscle wasting. Both limbs and respiratory muscles are affected. This leads to impaired mobility and breathing problems. Patients commonly die within a few years after the symptoms emerged. In rare cases, of which the British physicist Stephen Hawking is the most notable, patients can live with the disease for a long time. In Germany estimates show over 150,000 patients suffering from ALS -- an average of 1 in 500 people.

Proteins gone astray

Over the last few years, there has been increasing evidence that ALS and FTD -- a form of dementia associated with changes in personality and social behaviour -- may have similar or even the same origins. The symptoms overlap and common factors have also been found at the microscopic level. In many cases, particles accumulate and form clumps in the patient's nerve cells: this applies particularly to the TDP-43 protein.

"Normally, this protein is located in the cell nucleus and is involved in processing genetic information," explains molecular biologist Dr. Bettina Schmid, who works at the DZNE Munich site and at LMU. "However, in cases of disease, TDP-43 accumulates outside the nucleus forming aggregates." Schmid explains that it is not yet clear whether these clumps are harmful. "However, the protein's normal function is clearly disrupted. It no longer reaches the nucleus to perform its actual task. There seems to be a relationship between this malfunction and the disease."

Studies on zebrafish

However, until now little was known about the function of TDP-43. What are the consequences when this protein becomes non-functional? In order to answer this question, the team led by Bettina Schmid cooperated with the research group of Prof. Christian Haass to investigate the larvae of specially bred zebrafish. Their genetic code had been modified in such a way that no TDP-43 was produced in the organism of the fish. The result: the young fish showed massive muscle wasting and died a few days after hatching. Moreover, the extensions of the nerve cells which control the muscles were abnormal.

"To some extent, these are symptoms typical of ALS and FTD. Therefore, a loss of function of TDP-43 does seem to play a critical role in the disease," says Haass, Site Speaker of the DZNE Munich Site and chair of Metabolic Biochemistry at LMU.

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