Navigating our thoughts: Fundamental principles of thinking

Researchers propose that humans may think by using their brain's navigation system.

It is one of the most fundamental questions in neuroscience: How do humans think? Until recently, we seemed far from a conclusive answer. However, scientists from the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Leipzig, Germany, and the Kavli Institute for Systems Neuroscience in Trondheim, Norway, among them Nobel prize laureate Edvard I. Moser, offer a new proposal in the current issue of the journal Science -- Humans think using their brain's navigation system.

When we navigate our environment, two important cell types are active in our brain. Place cells in the hippocampus and grid cells in the neighboring entorhinal cortex form a circuit that allows orientation and navigation. The team of scientists suggests that our inner navigation system does much more. They propose that this system is also key to 'thinking', explaining why our knowledge seems to be organized in a spatial fashion.

"We believe that the brain stores information about our surroundings in so-called cognitive spaces. This concerns not only geographical data, but also relationships between objects and experience," explains Christian Doeller, senior author of the paper and the new director at the MPI CBS.

The term 'cognitive spaces' refers to mental maps in which we arrange our experience. Everything that we encounter has physical properties, whether a person or an object, and can therefore be arranged along different dimensions. "If I think about cars, I can order them based on their engine power and weight for example. We would have racing cars with strong engines and low weights as well as caravans with weak engines and high weight, as well as all combinations in between," says Doeller. "We can think about our family and friends in a similar way; for example, on the basis of their height, humor, or income, coding them as tall or short, humorous or humorless, or more or less wealthy." Depending on the dimensions of interest individuals might be stored mentally closer together or further away.

A Theory of Human Thinking

In their proposal, Doeller and his team combine individual threads of evidence to form a theory of human thinking. The theory begins with the Nobel Prize-winning discoveries of place and grid cells in rodents' brains, which were subsequently shown to exist in humans. Both cell types show patterns of activity representing the animal's position in space, for example, while it forages for food. Each position in space is represented by a unique pattern of activity. Together, the activity of place and grid cells allows the formation of a mental map of the surroundings, which is stored and reactivated during later visits.

The very regular activation pattern of grid cells can also be observed in humans -- but importantly, not only during navigation through geographical spaces. Grids cells are also active when learning new concepts, as shown by a study from 2016. In that study, volunteers learned to associate pictures of birds, which only varied in the length of their necks and legs, with different symbols, such as a tree or a bell. A bird with a long neck and short legs was associated with the tree whereas a bird with a short neck and long legs belonged to the bell. Thus, a specific combination of bodily features came to be represented by a symbol.

In a subsequent memory test, performed in a brain scanner, volunteers indicated whether various birds were associated with one of the symbols. Interestingly, the entorhinal cortex was activated, in much the same way as it is during navigation, providing a coordinate system for our thoughts.

"By connecting all these previous discoveries, we came to the assumption that the brain stores a mental map, regardless of whether we are thinking about a real space or the space between dimensions of our thoughts. Our train of thought can be considered a path though the spaces of our thoughts, along different mental dimensions," Jacob Bellmund, the first author of the publication, explains.

Read more at Science Daily

A new theory for phantom limb pain points the way to more effective treatment

The patient, missing his right arm, can see himself on screen in augmented reality, with a virtual limb. He can control it through the electrodes attached to his skin, which allows the patient to stimulate and reactivate those dormant areas of the brain.

Dr Max Ortiz Catalan of Chalmers University of Technology, Sweden, has developed a new theory for the origin of the mysterious condition, 'phantom limb pain'. Published in the journal Frontiers in Neurology, his hypothesis builds upon his previous work on a revolutionary treatment for the condition, that uses machine learning and augmented reality.

Phantom limb pain is a poorly understood phenomenon, in which people who have lost a limb can experience severe pain, seemingly located in that missing part of the body. The condition can be seriously debilitating and can drastically reduce the sufferer's quality of life. But current ideas on its origins cannot explain clinical findings, nor provide a comprehensive theoretical framework for its study and treatment.

Now, Max Ortiz Catalan, Associate Professor at Chalmers University of Technology, has published a paper that offers up a promising new theory -- one that he terms 'stochastic entanglement'.

He proposes that after an amputation, neural circuitry related to the missing limb loses its role and becomes susceptible to entanglement with other neural networks -- in this case, the network responsible for pain perception.

"Imagine you lose your hand. That leaves a big chunk of 'real estate' in your brain, and in your nervous system as a whole, without a job. It stops processing any sensory input, it stops producing any motor output to move the hand. It goes idle -- but not silent," explains Max Ortiz Catalan.

Neurons are never completely silent. When not processing a particular job, they might fire at random. This may result in coincidental firing of neurons in that part of the sensorimotor network, at the same time as from the network of pain perception. When they fire together, that will create the experience of pain in that part of the body.

"Normally, sporadic synchronised firing wouldn't be a big deal, because it's just part of the background noise, and it won't stand out," continues Max Ortiz Catalan. "But in patients with a missing limb, such event could stand out when little else is going on at the same time. This can result in a surprising, emotionally charged experience -- to feel pain in a part of the body you don't have. Such a remarkable sensation could reinforce a neural connection, make it stick out, and help establish an undesirable link."

Through a principle known as 'Hebb's Law' -- 'neurons that fire together, wire together' -- neurons in the sensorimotor and pain perception networks become entangled, resulting in phantom limb pain. The new theory also explains why not all amputees suffer from the condition- the randomness, or stochasticity, means that simultaneous firing may not occur, and become linked, in all patients.

In the new paper, Max Ortiz Catalan goes on to examine how this theory can explain the effectiveness of Phantom Motor Execution (PME), the novel treatment method he previously developed. During PME treatment, electrodes attached to the patient's residual limb pick up electrical signals intended for the missing limb, which are then translated through AI algorithms, into movements of a virtual limb in real time. The patients see themselves on a screen, with a digitally rendered limb in place of their missing one, and can then control it just as if it were their own biological limb . This allows the patient to stimulate and reactivate those dormant areas of the brain.

"The patients can start reusing those areas of brain that had gone idle. Making use of that circuitry helps to weaken and disconnect the entanglement to the pain network. It's a kind of 'inverse Hebb's law' -- the more those neurons fire apart, the weaker their connection. Or, it can be used preventatively, to protect against the formation of those links in the first place," he says.

Read more at Science Daily

Using the K computer, scientists predict exotic 'di-Omega' particle

Based on complex simulations of quantum chromodynamics performed using the K computer, one of the most powerful computers in the world, the HAL QCD Collaboration, made up of scientists from the RIKEN Nishina Center for Accelerator-based Science and the RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) program, together with colleagues from a number of universities, have predicted a new type of "dibaryon" -- a particle that contains six quarks instead of the usual three. Studying how these elements form could help scientists understand the interactions among elementary particles in extreme environments such as the interiors of neutron stars or the early universe moments after the Big Bang.

Particles known as "baryons" -- principally protons and neutrons -- are composed of three quarks bound tightly together, with their charge depending on the "color" of the quarks that make them up. A dibaryon is essentially a system with two baryons. There is one known dibaryon in nature -- deuteron, a deuterium (or heavy-hydrogen) nucleus that contains a proton and a neutron that are very lightly bound. Scientists have long wondered whether there could be other types of dibaryons. Despite searches, no other dibaryon has been found.

The group, in work published in Physical Review Letters, has now used powerful theoretical and computational tools to predict the existence of a "most strange" dibaryon, made up of two "Omega baryons" that contain three strange quarks each. They named it "di-Omega." The group also suggested a way to look for these strange particles through experiments with heavy ion collisions planned in Europe and Japan.

The finding was made possible by a fortuitous combination of three elements: better methods for making QCD calculations, better simulation algorithms, and more powerful supercomputers.

The first essential element was a new theoretical framework called the "time-dependent HAL QCD method": It allows researchers to extract the force acting between baryons from the large volume of numerical data obtained using the K computer.

The second element was a new computational method, the unified contraction algorithm, which allows much more efficient calculation of a system with a large number of quarks.

The third element was the advent of powerful supercomputers. According to Shinya Gongyo from the RIKEN Nishina Center, "We were very lucky to have been able to use the K computer to perform the calculations. It allowed fast calculations with a huge number of variables. Still, it took almost three years for us to reach our conclusion on the di-Omega."

Read more at Science Daily

Theory: Flexibility is at the heart of human intelligence

The more readily the brain forms and reforms its connectivity in response to changing needs, the better it works, according to Aron Barbey, author of the paper.

Centuries of study have yielded many theories about how the brain gives rise to human intelligence. Some neuroscientists think intelligence springs from a single region or neural network. Others argue that metabolism or the efficiency with which brain cells make use of essential resources are key.

A new theory, published in the journal Trends in Cognitive Sciences, makes the case that the brain's dynamic properties -- how it is wired but also how that wiring shifts in response to changing intellectual demands -- are the best predictors of intelligence in the human brain.

"When we say that someone is smart, we understand intuitively what that means," said University of Illinois psychology professor Aron Barbey, the author of the new paper. "Usually, we're referring to how good they are at making decisions and solving particular types of problems. But recently in neuroscience, there's been a focus on understanding in biological terms how general intelligence arises." That requires studying the structural and functional characteristics of the brain.

Scientists have long understood that the brain is modular, with different regions supporting specific abilities, Barbey said.

"For example, brain regions within the occipital lobe at the back of the brain are known to processes visual information," he said. But interpreting what one sees requires the integration of information from other brain modules.

"To identify an object, we also must classify it. That doesn't depend only on vision. It also requires conceptual knowledge and other aspects of information processing, which are supported by other brain regions," he said. "And as the number of modules increases, the type of information represented in the brain becomes increasingly abstract and general."

Scientists have struggled to understand how the brain organizes itself and have tried to identify a structure or region that performs that function.

"The prefrontal cortex, a structure at the front of the brain, for example, has expanded dramatically over the course of human evolution," Barbey said. Because this brain region is known to support several higher-order functions such as planning and organizing one's behavior, scientists have suggested that the prefrontal cortex drives general intelligence.

"But really, the entire brain -- its global architecture and the interactions among lower- and higher-level mechanisms -- is required for general intelligence," Barbey said.

Brain modules provide the basic building blocks from which larger, "intrinsic connectivity networks" are constructed, Barbey said. Each network includes multiple brain structures that are activated together when a person engages a particular cognitive skill.

"For example, the frontoparietal network is activated when attention is focused on external cues, the salience network is engaged when attention is directed to relevant events, and the default mode network is recruited when attention is focused internally," he said.

Neural networks are made up of two types of connections that are believed to support two types of information processing, Barbey said.

"There are the pathways that encode prior knowledge and experience, which we call 'crystallized intelligence.' And there are adaptive reasoning and problem-solving skills that are quite flexible, called 'fluid intelligence,'" he said.

Crystallized intelligence involves robust connections, the result of months or years of neural traffic on well-worn pathways. Fluid intelligence involves weaker, more transient pathways and connections that are formed when the brain tackles unique or unusual problems.

"Rather than forming permanent connections, we are constantly updating our prior knowledge, and this involves forming new connections," Barbey said. The more readily the brain forms and reforms its connectivity in response to changing needs, the better it works, he said.

Although researchers have known that flexibility is an important characteristic of human brain function, only recently has the idea emerged that flexibility provides the basis for human intelligence, he said.

Read more at Science Daily

How Life May Have First Emerged On Earth: Foldable Proteins in a High-Salt Environment

A structural biologist at the Florida State University College of Medicine has made discoveries that could lead scientists a step closer to understanding how life first emerged on Earth billions of years ago.

Professor Michael Blaber and his team produced data supporting the idea that 10 amino acids believed to exist on Earth around 4 billion years ago were capable of forming foldable proteins in a high-salt (halophile) environment. Such proteins would have been capable of providing metabolic activity for the first living organisms to emerge on the planet between 3.5 and 3.9 billion years ago.

The results of Blaber's three-year study, which was built around investigative techniques that took more than 17 years to develop, are published in the journal Proceedings of the National Academy of Sciences.

The first living organisms would have been microscopic, cell-like organizations capable of replicating and adapting to environmental conditions -- a humble beginning to life on Earth.

"The current paradigm on the emergence of life is that RNA came first and in a high-temperature environment," Blaber said. "The data we are generating are much more in favor of a protein-first view in a halophile environment."

The widely accepted view among scientists is that RNA, found in all living cells, would have likely represented the first molecules of life, hypothesizing an "RNA-first" view of the origin of living systems from non-living molecules. Blaber's results indicate that the set of amino acids produced by simple chemical processes contains the requisite information to produce complex folded proteins, which supports an opposing "protein-first" view.

Another prevailing view holds that a high-temperature (thermophile) environment, such as deep-ocean thermal vents, may have been the breeding ground for the origin of life. "The halophile, or salt-loving, environment has typically been considered one that life adapted into, not started in," Blaber said. "Our study of the prebiotic amino acids and protein design and folding suggests the opposite."

Without the ability to fold, proteins would not be able to form the precise structures essential for functions that sustain life as we know it. Folding allows proteins to take on a globular shape through which they can interact with other proteins, perform specific chemical reactions, and adapt to enable organisms to exploit a given environment.

"There are numerous niches that life can evolve into," Blaber said. "For example, extremophiles are organisms that exist in high temperatures, high acidity, extreme cold, extreme pressure and extreme salt and so on. For life to exist in such environments it is essential that proteins are able to adapt in those conditions. In other words, they have to be able to fold."

Comet and meteorite fragments, like those that recently struck in the Urals region of Russia, have provided evidence regarding the arrival of amino acids on Earth. Such fragments predate Earth and would have been responsible for delivering a set of 10 prebiotic (before life) amino acids, whose origins are in the formation of our solar system.

Today the human body uses 20 common amino acids to make all its proteins. Ten of those emerged through biosynthetic pathways -- the way living systems evolve. Ten -- the prebiotic set -- can be made by chemical reactions without requiring any living system or biosynthetic pathway.

Scientific evidence exists to support many elements in theories of abiogenesis (the emergence of life), including the time frame (around 3.5 to 3.9 billion years ago) and the conditions on Earth and in its atmosphere at that time. Earth would have been made up of volcanic land masses (the beginning of the formation of continents), salty oceans and fresh-water ponds, along with a hot (around 80 degrees Celsius) and steamy atmosphere comprising carbon dioxide and nitrogen. Oxygen would have come later as a by-product of green plant life and bacteria that emerged.

Using a technique called top-down symmetric deconstruction, Blaber's lab has been able to identify small peptide building blocks capable of spontaneous assembly into specific and complex protein architectures. His recent work explored whether such building blocks can be composed of only the 10 prebiotic amino acids and still fold.

His team has achieved foldability in proteins down to 12 amino acids -- about 80 percent of the way to proving his hypothesis.

Read more at Science Daily

Our Solar System Is Not Quite as Special as Once Believed, New Research Suggests

Some 4.567 billion years ago, our solar system's planets spawned from an expansive disc of gas and dust rotating around the sun. While similar processes are witnessed in younger solar systems throughout the Milky Way, the formative stages of our own solar system were believed to have taken twice as long to occur. Now, new research lead by the Centre for Star and Planet Formation at the Natural History Museum of Denmark, University of Copenhagen, suggests otherwise. Indeed, our solar system is not quite as special as once believed.

Using improved methods of analysis of uranium and lead isotopes, the current study of primitive meteorites has enabled researchers to date the formation of two very different types of materials, so-called calcium-aluminum-rich inclusions (or CAI's for short) and chondrules, found within the same meteorite. By doing so, the chronology and therefore overall understanding of our solar system's development has been altered. The study has just been published in the scientific journal Science.

4.567 billion years -- this is how far back we must travel to experience our nascent solar system. The researchers at the University of Copenhagen Centre for Star and Planet Formation took a closer look at the first three million years of the solar system's development by analysing primitive meteorites composed of a blend of our solar system's very oldest materials. In part, the study confirmed previous analyses demonstrating that CAI's were formed during a very short period of time. The new discovery is that the so-called chondrules were formed during the first three million years of the solar system's development as well. This stands in contrast with previous assumptions asserting that chondrules only started forming roughly two million years after CAIs.

Painting a new picture of the Solar System

"By using this process to date the formation of these two very different types of materials found in the same meteorite, we are not only able to alter the chronology of our solar system's historical development, we are able to paint a new picture of our solar system's development, which is very much like the picture that other researchers have observed in other planetary systems," says James Connelly of the Centre for Star and Planet Formation.

We aren't that special...

Showing that chondrules are as old as CAIs addresses a long-standing question of why chondrule formation should be delayed by up to 2 million years after CAIs. The answer -- it is not.

Read more at Science Daily

Understanding Stonehenge: Two Explanations

After centuries of puzzling over the meaning of Stonehenge, laser-equipped researchers have concluded that the prehistoric monument was built to show off the solstices.

Apart from revealing 71 new images of Bronze Age axeheads, which bring the number of this type of carvings known at Stonehenge to 115, the English Heritage groundbreaking analysis showed that the stones were shaped and crafted differently in various parts of the stone circle.

In particular, the stones first seen when approaching the monument from the north-east were completely "pick dressed." Stonehenge workers removed their brown and grey surface crust to show a bright, grey-white surface that would glisten at sunset on the shortest day of the year and in the dawn light on the longest day.

According to the researchers, this provides an almost definitive proof that it was the intent of Stonehenge's builders to align the monument with the two solstices along a north-east/south-west axis.

Located in the county of Wiltshire, at the center of England's densest complex of Neolithic and Bronze Age monuments, Stonehenge has been the subject of myth, legend and -- more recently -- scientific research for more than eight centuries.

The mysterious circle of large standing stones has been interpreted in the most disparate ways -- as a temple for sun worship, a temple of the ancient druids, a healing center, a burial site and a huge calendar.

The new laser findings appear to be compatible with two main theories taking shape in recent years to explain the monument's purpose.

According to archaeologist Mike Parker Pearson, head of the Stonehenge Riverside Project, the iconic monument was built as a grand act of union after a long period of conflict between east and west Britain.

Another theory, posed by archaeologists Geoff Wainwright and Timothy Darvill, says Stonehenge was a destination to which the sick traveled from around Europe to be healed by its magical powers.

"The scanning work at Stonehenge is really important and has opened our eyes to many new aspects of Neolithic technology," Darvill, professor of archaeology in the School of Applied Sciences at Bournemouth University, England, told Discovery News.

Darvill and Wainwright made one of the most significant findings in 2005, when they located the quarry where the bluestones, which form Stonehenge's inner circle, were cut around 2500 B.C.

The archaeologists discovered a "small crag-edged promontory with a stone bank across its neck" at one of the highest points of Carn Menyn, a mountain in the Preseli Hills of Pembrokeshire, in southwest Wales.

The site, which measures less than half a hectare, is characterized by numerous prone pillar stones with clear signs of working. Darrvill described it as "a veritable Aladdin's Cave of made-to-measure pillars for aspiring circle builders."

The bluestones weighed about four tons and were between six and nine feet in height and would have been transported 240 miles to the famous site at Salisbury Plain in Wiltshire.

According to Darvill, the color and the presence of distinctive white spots made the Preseli Hills stones very pleasing aesthetically.

"Importantly, the methods of working the bluestones seems to be the same as for the central Trilithons and serves to support the idea I put forward some time ago that these two components of the monument were contemporary and somehow linked," Darvill said.

According to the archaeologist, the huge stones were taken on such a journey from their Welsh location because they were believed to harbor great powers.

In 2008, Darvill and Wainwright excavated a small patch of earth at Stonehenge. The dig unearthed about 100 pieces of organic material from the original bluestone sockets and provided the most accurate dating for their erection, pinpointing the bluestone construction to 2300 B.C. It also produced a large number of bluestone chippings, as if people flaked them off to create little amulet bits.

The presence of a large number of human remains in tombs near Stonehenge showing physical injury and disease and analysis of teeth reveal that around half of the corpses were not native to the Stonehenge area and suggested Stonehenge served as a center for healing, said the archaeologists.

Attracted by the powers of the bluestones, the sick and injured would have come to the site from far away.

"The new work indirectly supports the healing hypothesis as it shows the importance of the stones from Wales," Darvill said.

"It also shows that most of them have had bits chipped off them and some have been reduced to stumps by removals exactly as we suggested was the case," he added.

But according to Mike Parker Pearson, the enigmatic stone circle had nothing to do with sickness and diseases. On the contrary, it was built as a grand act of union after a long period of conflict between east and west Britain.

"Stonehenge itself was a massive undertaking, requiring the labor of thousands to move stones from as far away as west Wales, shaping them and erecting them. Just the work itself, requiring everyone literally to pull together, would have been an act of unification," Parker Pearson said.

Because of Stonehenge's solstice-aligned avenue, prehistoric people would have seen the spot as nothing less than the "center of the world."

According to Parker Pearson, the discovery of the winter sunset axis at Stonehenge by the laser scan project supports his previous findings.

Read more at Discovery News

Big Bang Theory Challenged by Big Chill

The start of the Universe should be modeled not as a Big Bang but more like water freezing into ice, according to a team of theoretical physicists at the University of Melbourne and RMIT University.

They have suggested that by investigating the cracks and crevices common to all crystals -- including ice -- our understanding of the nature of the Universe could be revolutionized.

Lead researcher on the project, James Quach said current theorizing is the latest in a long quest by humans to understand the origins and nature of the Universe.

"Ancient Greek philosophers wondered what matter was made of: was it made of a continuous substance or was it made of individual atoms?" he said. "With very powerful microscopes, we now know that matter is made of atoms."

"Thousands of years later, Albert Einstein assumed that space and time were continuous and flowed smoothly, but we now believe that this assumption may not be valid at very small scales.

"A new theory, known as Quantum Graphity, suggests that space may be made up of indivisible building blocks, like tiny atoms. These indivisible blocks can be thought about as similar to pixels that make up an image on a screen. The challenge has been that these building blocks of space are very small, and so impossible to see directly."

However James Quach and his colleagues believe they may have figured out a way to see them indirectly.

"Think of the early universe as being like a liquid," he said. "Then as the universe cools, it 'crystallizes' into the three spatial and one time dimension that we see today. Theorized this way, as the Universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice."

RMIT University research team member Associate Professor Andrew Greentree said some of these defects might be visible.

"Light and other particles would bend or reflect off such defects, and therefore in theory we should be able to detect these effects," he said.

The team has calculated some of these effects and if their predictions are experimentally verified, the question as to whether space is smooth or constructed out of tiny indivisible parts will be solved once and for all.

Read more at Science Daily

Climate Change May Have Doomed Neanderthals

When climate took a turn toward the cold tens of thousands of years ago, both Neanderthals and early humans started traveling further distances to find food, found a new study.

As a result, the two groups encountered each other often.. And a consequent boom in inter-species liaisons eventually led to the extinction of Neanderthals.

While much of the theory remains controversial, the study adds to growing evidence that Neanderthals developed advanced cultures and that they adapted to changes in the environment just like early humans did.

The study also hints at what's to come if climate change forces modern cultures to blend, as their homes become inhospitable from drought, flooding or severe weather.

"We are increasingly finding evidence of sophisticated behavior among Neanderthals, and now the question is: If they were so smart, why did they become extinct?" said Michael Barton, an anthropologist at Arizona State University in Tempe.

"Our answer is that they became extinct because they were so smart, not in spite of it," he said. "They were doing what everyone else was doing, and how they dealt with worldwide environmental change made their population and probably other endemic populations disappear."

To see how ancient groups of people moved around as the climate changed, Barton and colleagues analyzed stone tools from 167 cave sites that spanned Eurasia from the Near East to Gibraltar. Fossils indicated whether Neanderthals, early humans or both had lived in each cave for some period of time between about 128,000 and 11,500 years ago.

As they scanned the tools, the major clue the researchers looked for was how worn down the stones were. That, in turn, hinted at how much moving around their owners did.

If people stayed put, for example, they tended to stockpile rocks and just chip off new flakes whenever they needed one. If they were moving around a lot, on the other hand, they carried tools with them, and they ended up sharpening and re-sharpening those tools over and over – ultimately leading to duller, more worn tools. In the fossil record, the difference between the two tool-making strategies is clear.

When the researchers analyzed the tools, they found that climate determined the migration patterns of both early humans and Neanderthals. When it was warm and resources were abundant but patchy, well-worn tools suggested that everyone moved around from place to place. They didn't roam very far, so they wouldn't have had a lot of contact with each other, but they didn’t stay in one place for a long time, either.

But when temperatures plummeted as a new glacial period approached, both Neanderthals and our human ancestors set up home bases where they could keep flaking off sharp new tools. From there, foraging parties covered much longer distances. As they roamed, the two groups intermingled more than they had ever had before

Because humans outnumbered Neanderthals, computer modeling over 1,500 generations showed that intermingling would have led to the eventual disappearance of a distinct Neanderthal group, whereas the smaller-scale movements seen in warmer times wouldn’t have had much of an effect at all.

Neanderthals didn't exactly go extinct, the researchers reported in the journal Human Ecology. Instead, Barton said, their genes were essentially swallowed up into the human genome.

Studies have shown similar patterns of extinction in endangered animal species, Barton said. And he pointed to recent evidence that remnants of Neanderthal DNA still persist in modern Europeans.

Neanderthals were certainly intelligent enough to adapt to climate change, said Richard Klein, an anthropologist at Stanford University in Palo Alto, Calif. But he is more skeptical about the conclusion that mating between Neanderthals and early humans was widespread enough to lead to Neanderthal extinction.

Read more at Discovery News

Self-Delusion Is a Winning Survival Strategy, Study Suggests

Harboring a mistakenly inflated belief that we can easily meet challenges or win conflicts is actually good for us, a new study suggests. Researchers have shown for the first time that overconfidence actually beats accurate assessments in a wide variety of situations, be it sport, business or even war.

However, this bold approach also risks wreaking ever-greater havoc. The authors cite the 2008 financial crash and the 2003 Iraq war as just two examples of when extreme overconfidence backfired.

A team from the University of Edinburgh and the University of California, San Diego used a mathematical model to simulate the effects of overconfidence over generations. It pitted overconfident, accurate, and under-confident strategies against each other.

A paper published in Nature September 14 shows that overconfidence frequently brings rewards, as long as spoils of conflict are sufficiently large compared with the costs of competing for them. In contrast, people with unbiased, accurate perceptions usually fare worse.

The implications are that, over a long period of time the evolutionary principal of natural selection is likely to have favored a bias towards overconfidence. Therefore people with the mentality of someone like boxer Mohammad Ali would have left more descendents than those with the mindset of film maker Woody Allen.

The evolutionary model also showed that overconfidence becomes greatest in the face of high levels of uncertainty and risk. When we face unfamiliar enemies or new technologies, overconfidence becomes an even better strategy.

Read more at Science Daily

Is This the Face of Jack The Ripper?

Thin-haired with deep-set grey eyes and a large, red pimpled nose: this is how Jack the Ripper, perhaps the most notorious murderer in history, might have looked, according to new archival research into police documents.

Retired British police detective, Trevor Marriott, gathered together evidence and has built a case against Carl Feigenbaum, a 54-year-old German merchant seaman, and made him the top suspect for committing the horrific and notorious murders between August and November 1888.

At that time, at least five women in the Whitechapel area in London were found horribly disfigured, often with organs missing.

The name Jack the Ripper was coined in taunting letters sent to the press and police, in which the writer claimed credit for the crimes.

Ripper's career ended as suddenly as it began with the murderer still at large, making his case one of the history's greatest murder mysteries.

Since the first murder 123 years ago, more than 200 suspects have been named, including Lewis Carroll, author of "Alice in Wonderland," Prince Albert Victor and Sir John Williams, obstetrician to the Royal Family.

According to Marriott, there are a number of factors pointing to the obscure German merchant.

"For example, he killed a woman in ripper like fashion with a long bladed knife which he carried. It was the same type of knife used to kill the Whotechapel victims," Marriott told Discovery News.

The murder occurred in Manhattan, and the woman was his landlady Juliana Hoffman.

For the brutal killing, Feigenbaum went to the electric chair in New York in 1896.

Marriott begun his investigation by examining groups of people who may have been in Whitechapel at the time of the killings.

Since the district is just a short distance from London's docks, sailors were included in the group of suspects.

Crew lists for ships that were in dock at those times revealed that Feigenbaum, who was already in the 200 suspect list, was visiting London at the time of each murder.

"He had been employed as a merchant seaman for The Nordeutcher Line which had a ship in London on all the murder dates," Marriott said.

The former detective also found a 1896 report in the National Police Gazette in which Feigenbaum’s lawyer detailed a confession made by his client at Sing Sing jail.

"I have for years suffered from a singular disease, which induces an all-absorbing passion; this passion manifests itself in a desire to kill and mutilate the woman who falls in my way. At such times I am unable to control myself," he confessed.

No photographs of Feigenbaum exist, but Marriott put together an e-fit based on the description of him when he was in prison in the US.

According to the Sing Sing admittance form, he had deep set grey eyes, dark brown hair and a "medium sized head."

Standing 5ft 4½ tall and weighting 126 pounds, he had a large, red nose with raw pimples, with poor teeth, almost entirely gone on left sides.

The prison official also noted he had "anchor in india ink on right hand at base of thumb and first finger" and a "round scar or birthmark on right leg below left knee."

Given the surgical precision of the mutilations, it was usually assumed that the elusive killer had a great knowledge of human anatomy.

But Marriott argued that the removal of the women's organs occurred in the mortuary, as the 1832 Anatomy Act made it legal to remove organs for medical training.

Read more at Discovery News

What if Earth Were a Cube?

Back in 1884, a Swiss astronomer by the name of Arndt made headlines when he claimed to have discovered a very curious planet in an orbit beyond Neptune -- a surprisingly cubical planet.

You know, like Bizarro World from the Super Man comics.

Of course even in 1884, everyone knew this was bunk. The New York Times even ran a piece titled "The Cubical Planet" in their Nov. 16 edition.

As informative as it is stuffy, the Gilded Age article interviews physicist Dr. Theodore Vankirk, who first dismisses the prospect of a square planet as pure hooey, and then proceeds to wax scientific about just what a cube world would be like.

It all comes down to gravity. On our spherical Earth, gravity pulls "down" us toward the planet's center of mass. So on a flat surface, we naturally stand up straight.

A hypothetical cube world, however, would feature six square faces and you'd only encounter up/down gravity toward the centers of these regions. As you traveled closer and closer to the edge, it would feel like you were walking up an incline and it would be difficult to stand up straight because the gravitational pull would draw you toward the center of the massive cube, which wouldn't lie directly beneath your feet.

Standing on the "edge" of this cube world would feel like standing atop a mountain range.

Contemporary cosmologist Karen L. Masters also finds the topic of cube worlds fascinating -- especially the atmospheric possibilities. As she explains in Cornell's Ask a Physicist feature, all six faces of the plant aces would boast temperate weather, centralized bodies of water and none of them would feature polar or equatorial weather.  What's more, the pointy edges of the cube would actually poke through the planet's atmosphere like titanic mountains. Here's her explanation:

    Let's assume that the atmosphere goes up 1000 km above the Earth (when it is a sphere), and so is a sphere itself of radius 6400km+1000km=7400km. This should be about the right number. A cube with the same volume as the spherical Earth would have a side 10,000 km (6,400 miles) long so the corners are 8700 km from the center! They would definitely stick out above the atmosphere.

As I was poking around the net on this topic, I also ran across this amusing tidbit from a 1964 edition of the Rice University campus paper. A mysterious, well-dressed gentleman had been observed hanging out around the Houston-area campus, distributing literature about an alien, cubical planet.

The man claimed that the planet was called Aocicinori and that it was the 63rd in a system of 96 planets. He showed off maps of the world, as well as some colorful illustrations of the creatures that lived there. The Rice University article reveals that these materials were created by Scotland L. Moore, an outpatient form the Houston State Psychiatric Institute.

Read more at Discovery News

Study Builds On Plausible Scenario for Origin of Life On Earth

A relatively simple combination of naturally occurring sugars and amino acids offers a plausible route to the building blocks of life, according to a paper published in Nature Chemistry.

The study shows how the precursors to RNA could have formed on Earth before any life existed. It was authored by Jason E. Hein, Eric Tse and Donna G. Blackmond, a team of researchers with the Scripps Research Institute. Hein is now a chemistry professor with University of California, Merced.

Biological molecules, such as RNA and proteins, can exist in either a natural or unnatural form, called enantiomers. By studying the chemical reactions carefully, the research team found that it was possible to generate only the natural form of the necessary RNA precursors by including simple amino acids.

"These amino acids changed how the reactions work and allowed only the naturally occurring RNA precursors to be generated in a stable form," said Hein. "In the end, we showed that an amazingly simple result emerged from some very complex and interconnected chemistry."

The natural enantiomer of the RNA precursor molecules formed a crystal structure visible to the naked eye. The crystals are stable and avoid normal chemical breakdown. They can exist until the conditions are right for them to change into RNA.

More at Science Daily

Bill Gates’ advanced power reactor gets closer to reality.

Terrapower, a startup funded in part by Nathan Myhrvold and Bill Gates, is moving closer to building a new type of nuclear reactor called a traveling wave reactor that runs on an abundant form of uranium. The company sees it as a possible alternative to fusion reactors, which are also valued for their potential to produce power from a nearly inexhaustible source of fuel.

Work on Terrapower’s reactor design began in 2006. Since then, the company has changed its original design to make the reactor look more like a conventional one. The changes would make the reactor easier to engineer and build. The company has also calculated precise dimensions and performance parameters for the reactor. Terrapower expects to begin construction of a 500-megawatt demonstration plant in 2016 and start it up in 2020. It’s working with a consortium of national labs, universities, and corporations to overcome the primary technical challenge of the new reactor: developing new materials that can withstand use in the reactor core for decades at a time. It has yet to secure a site for an experimental plant and surprisingly, the funding to build it.

Full Story at Technology News