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Flash memory chip built out of single-atom-thick components

Flash memory chip built out of single-atom-thick components | Amazing Science |
Graphene and molybdenum disulfide layers make up most of the working parts.


The basic outline of a flash memory device involves two electrodes that feed current through a semiconductor within the device. When a negative voltage is sent across a device from a control electrode, electrons are able to feed into a reservoir that retains the charge; reversing the voltage allows them to escape. The presence of the electrons in the reservoir can be read out by sending current through the semiconductor.


To build a compact version of the device, the authors of the new paper (who are based in Lausanne, Switzerland) started with two sheets of graphene layered on some silicon, separated by a small gap. These served as the electrodes, with the device itself acting as a bridge between them. The next layer on top of that was the semiconductor, formed by a single-molecule-thick sheet of molybdenum disulfide. Above that, a layer of an insulator that allows electrons to tunnel through it separated the conductor from the charge reservoir. To hold the charges, the authors used a few layers of graphene. That was topped by a bit more insulator and another electrode that acted to control the device, setting it to read or erase.


The insulator used in this work wasn't a single atom thick (although insulators of this sort are known) and the graphene charge reservoir was several layers thick, so there were clearly a number of layers involved. But still, this is a very thin device, and can potentially be made even thinner. The manufacturing technique could use some improvements as well, given that one of the steps involved finding individual layers using an optical microscope.


In any case, the devices worked. Applying a positive voltage to the control electrode allowed charge to accumulate in the graphene layers, and its presence could be read out based on the current flowing through the device. Reversing the voltage across the control electrode erased the device. They went through 120 write/erase cycles, and the device still functioned. They also left the device unpowered for a bit, and found that while its storage did decay a bit, it only decayed very slowly. Based on the rate, they expect that, after 10 years, 30 percent of the original charge would still be present.

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Targeting B-Raf kinase in melanomas

Targeting B-Raf kinase in melanomas | Amazing Science |

Melanoma is a type of skin cancer. It arises from specialized pigmented cells in our body known as melanocytes that are responsible for the production of melanin, a pigment responsible for skin and hair color. Because most melanoma cells still make melanin, melanoma tumors are usually brown or black. It accounts for 4% of all skin cancers; however, it is responsible for the largest numbers of skin cancer related death in the world. In the US, according to the national cancer institute, estimated new cases and deaths from melanoma in 2013 would be 76,690 and 9,480 respectively.


Several studies using molecular profiling and genomic sequencing have shown that melanoma is a disease of a heterogeneous group of tumors, and its progression is driven by specific oncogenic mutations. In 2002, Davies et al. first reported the presence of B-RAF somatic missense mutations in 66% of malignant melanomas. RAF (Rapidly growing Fibrosarcoma) protein is a serine/thereonine kinase. Three members of this kinase family are A-RAF, B-RAF, and C-RAF. These serine/threonine protein kinases, downstream of the membrane-bound small G protein RAS, are components of the mitogen activtated protein kinase (MAPK) signal transduction pathway. With closely overlapping functions, all members of the RAF family are associated with the activation of the MAPK pathway. Activation of the MAPK pathway has been associated with uncontrolled growth and drug resistance in several tumors. Researchers have identified over 50 distinct mutations in the B-RAF gene so far. However, most of these mutations are extremely rare. The most common mutation in melanoma, accounting for 90% of all B-RAF mutations, is the V600E mutation that occurs as a result of substitution of amino acid valine (V) to glutamic acid (E) at codon 600. Approximately 50% of melanomas harbor the V600E B-RAF mutation, while other mutations observed in melanomas are usually associated with the activation of N-RAS and c-KIT.


Several studies reported association of the V600E B-RAF mutation with the progression of melanoma. In a pre-clinical study Smalley et al. (2010) observed tumor formation in immunocompromised mice following introduction of mutant B-RAF in melanocytes. Inversely, in their study, Smalley et al. also observed that inhibition of mutated B-RAF using RNA-interference resulted in tumor cell death. In addition, several other studies reported that inhibition of V600E mutant B-RAF prevents melanoma cell proliferation, induces apoptosis (programmed cell death), and also blocks melanoma xenograft growth in vivo. Even though many studies suggested that V600E B-RAF mutation may not be sufficient alone for melanoma induction, a wealth of evidence demonstrated that mutated B-RAF is necessary for the maintenance and progression of melanoma in human. Therefore, mutated B-RAF represents a therapeutic target in melanoma, which is why several B-RAF kinase inhibitors have already been developed. Sorafenib was the first B-RAF inhibitor studied in melanoma patients. In addition, vemurafenib (Zelboraf) and dabrafenib (GSK2118436) were also studied in melanoma patients with V600E B-RAF mutations.  In 2011 vemurafenib received FDA approval for the treatment of melanoma patients harboring the V600E B-RAF mutation. In clinical trials, in which patients were undergoing treatment with vemurafenib, the drug reduced risk of death by 63% and risk of progression by 74%.


At present several clinical trials also evaluate clinical efficacy of vemurafenib in combination with leflunomide  (antirheumatic drug), GDC-0973 (MEK inhibitor), and metformin (antidiabetic drug). In addition, several other drugs targeting B-RAF and its downstream pathway are also in development. Therefore, further improvements can be expected in this personalized and targeted therapy in melan

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Earthquakes make gold veins -- pressure changes in Earth crust cause precious metals to deposit

Earthquakes make gold veins -- pressure changes in Earth crust cause precious metals to deposit | Amazing Science |

Scientists have long known that veins of gold are formed by mineral deposition from hot fluids flowing through cracks deep in Earth’s crust. But a study published today in Nature Geoscience has found that the process can occur almost instantaneously — possibly within a few tenths of a second.


The process takes place along 'fault jogs' — sideways zigzag cracks that connect the main fault lines in rock, says first author Dion Weatherley, a seismologist at the University of Queensland in Brisbane, Australia.

When an earthquake hits, the sides of the main fault lines slip along the direction of the fault, rubbing against each other. But the fault jogs simply open up. Weatherley and his co-author, geochemist Richard Henley at the Australian National University in Canberra, wondered what happens to fluids circulating through these fault jogs at the time of the earthquake.


What their calculations revealed was stunning: a rapid depressurization that sees the normal high-pressure conditions deep within Earth drop to pressures close to those we experience at the surface. For example, a magnitude-4 earthquake at a depth of 11 kilometres would cause the pressure in a suddenly opening fault jog to drop from 290 megapascals (MPa) to 0.2 MPa. (By comparison, air pressure at sea level is 0.1 MPa.) “So you’re looking at a 1,000-fold reduction in pressure,” Weatherley says.


Big earthquakes will produce bigger pressure drops, but for gold-vein formation, that seems to be overkill. More interesting, Weatherley and Henley found, is that even small earthquakes produce surprisingly big pressure drops along fault jogs. “We went all the way to magnitude –2,” Weatherley says — an earthquake so small, he adds, that it involves a slip of only about 130 micrometres along a mere 90 centimetres of the fault zone. “You still get a pressure drop of 50%,” he notes.

That, Weatherley adds, might be one of the reasons that the rocks in gold-bearing quartz deposits are often marbled with a spider web of tiny gold veins. “You [can] have thousands to hundreds of thousands of small earthquakes per year in a single fault system,” he says. “Over the course of hundreds of thousands of years, you have the potential to precipitate very large quantities of gold. Small bits add up.”


Weatherley says that prospectors might be able to use remote sensing techniques to find new gold deposits in deeply buried rocks in which fault jogs are common. “Fault systems with lots of jogs can be places where gold can be distributed,” he explains.


But Taka’aki Taira, a seismologist at the University of California, Berkeley, thinks that the finding might have even more scientific value. That’s because, in addition to showing how quartz deposits might form in fault jogs, the study reveals how fluid pressure in the jogs rebounds to its original level — something that could affect how much the ground moves after the initial earthquake.

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Why makeup matters - Brain uses contrast of facial features to judge a person's age

Why makeup matters - Brain uses contrast of facial features to judge a person's age | Amazing Science |

The contrasting nature of facial features is one of the signals that people unconsciously use to decipher how old someone looks, says Psychology Prof. Richard Russell, who has been collaborating with researchers from CE.R.I.E.S. (Epidermal and Sensory Research and Investigation Center), a department of Chanel Research and Technology dedicated to skin related issues and facial appearance.


"Unlike with wrinkles, none of us are consciously aware that we're using this cue, even though it stares us in the face every day," said Russell. The discovery of this cue to facial age perception may partly explain why cosmetics are worn the way they are, and it lends more evidence to the idea that makeup use reflects our biological as well as our cultural heritage, according to Russell. In one study, Russell and his team measured images of 289 faces ranging in age from 20 to 70 years old, and found that through the aging process, the color of the lips, eyes and eyebrows change, while the skin becomes darker. This results in less contrast between the features and the surrounding skin – leaving older faces to have less contrast than younger faces.


The difference in redness between the lips and the surrounding skin decreases, as does the luminance difference between the eyebrow and the forehead, as the face ages. Although not consciously aware of this sign of aging, the mind uses it as a cue for perceiving how old someone is.

In another study involving more than a hundred subjects in Gettysburg and Paris, the scientists artificially increased these facial contrasts and found that the faces were perceived as younger. When they artificially decreased the facial contrasts, the faces were perceived as older.

The image shows two identical images of the same face, except that the facial contrast has been increased in the left image and decreased in the right image. The face on the left appears younger than the one on the right.

Cosmetics are commonly used to increase aspects of facial contrast, such as the redness of lips. Scientists propose that this can partly explain why makeup is worn the way that it is – shades of lipstick that increase the redness of the lips are making the face appear younger, which is related to healthiness and beauty.

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The RX J0648.0-4418 white dwarf star "Dizzy" is the densest and fastest spinning dwarf star known

The RX J0648.0-4418 white dwarf star "Dizzy" is the densest and fastest spinning dwarf star known | Amazing Science |

Dizzy the white dwarf star is under a powerful curse, doomed to spin faster than any of its peers. No one knows why poor Dizzy was handed such a fate, but its wild gyrations mean that the star could be headed for a violent death, perhaps unlike any stellar explosion we've seen before.


White dwarfs are the dense cores left over when stars like the sun die. Dizzy, officially catalogued as RX J0648.0-4418, is probably the densest known white dwarf, packing more than the mass of our sun into a ball about the size of Mars.


The star takes only 13.2 seconds to spin once on its axis. The next fastest white dwarf, AE Aquarii, takes 33 seconds per revolution. If Earth were somehow set spinning as fast as Dizzy, people would rapidly be flung out into space, followed closely by the oceans, mountains and crust. The deep rocky mantle and almost all of Earth's core would also be torn apart by this super-spin.


"Even if this were a normal white dwarf of half a solar mass, it would be close to or beyond the limit of break-up," says Sandro Mereghetti of the Institute of Astrophysics and Cosmic Physics in Milan, Italy. Luckily for Dizzy, being extra-dense means that its surface gravity is well over a million times as strong as Earth's, so it can hold itself together.


It is possible Dizzy was born this way, the core of a fast-spinning ordinary star that spun even faster as it contracted. But Mereghetti suspects otherwise.


He thinks Dizzy got a push from its orbital partner, a hot star called HD 49798. A few hundred thousand years ago, an ageing HD 49798 began to expand into a red giant, but then its outer layers were siphoned off by the white dwarf, he argues. Spiralling down to hit Dizzy at an oblique angle, that material would have made the dwarf spin super-fast.


One day HD 49798 will again swell in size as it runs out of nuclear fuel. Then Dizzy will take up even more material. A few million years on, it will reach a critical mass that should signal its demise. What happens next depends on chemistry.


If Dizzy has an oxygen-carbon mix, like most white dwarfs, an explosive thermonuclear reaction could rip through its body, generating a type Ia supernova. Because of Dizzy's spin, the critical mass for this could be higher than normal, so the resulting supernova would be ultra-bright. Dizzy is close enough to us that we might see it shining as bright as the full moon.


But Dizzy might be a blend of oxygen and neon. In that case, the dwarf could collapse and leave behind what is called a millisecond pulsar – a rapidly spinning neutron star. This type of stellar explosion has never been seen before, although it would be a much less spectacular event.

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Study Raises Hope for New Anti-Aging Drugs

Study Raises Hope for New Anti-Aging Drugs | Amazing Science |

A new research published in the March 8, 2013  issue of Science finally proves that a single anti-ageing enzyme in the body can be targeted, with the potential to prevent age-related diseases and extend lifespans.


“Drugs that combat ageing may be available within five years,” said study senior author Prof David Sinclair from Harvard Medical School, and the University of New South Wales.


The target enzyme, SIRT1, is switched on naturally by calorie restriction and exercise, but it can also be enhanced through activators. The most common naturally-occurring activator is resveratrol, which is found in small quantities in red wine, but synthetic activators with much stronger activity are already being developed.


Although research surrounding resveratrol has been going for a decade, until now the basic science had been contested. The study shows all of the 117 drugs tested work on the single enzyme through a common mechanism. This means that a whole new class of anti-ageing drugs is now viable, which could ultimately prevent cancer, Alzheimer’s disease and type 2 diabetes.


“Ultimately, these drugs would treat one disease, but unlike drugs of today, they would prevent 20 others. In effect, they would slow ageing,” Prof Sinclair said. “In the history of pharmaceuticals, there has never been a drug that tweaks an enzyme to make it run faster.”


“Our drugs can mimic the benefits of diet and exercise, but there is no impact on weight,” Prof Sinclair said. “The first therapeutic to be marketed will be for diabetes.” There have been limited trials in people with type 2 diabetes and the skin inflammatory disease, psoriasis. There were benefits to the metabolism in the first group and a reduction in skin redness in the second.


The drugs can be administered orally, or topically. So far, there have been no drugs developed targeting ageing skin, but one major skin care range has developed a crème with resveratrol in it. “While any drug would be strictly prescribed for certain conditions, one day, they could be taken orally as a preventative. This would be in much the same way as statin drugs are commonly prescribed to prevent, instead of simply treating, cardiovascular disease.”


In animal models, overweight mice given synthetic resveratrol were able to run twice as far as slim mice and they lived 15 per cent longer. “Now we are looking at whether there are benefits for those who are already healthy. Things there are also looking promising,” the scientist said.


“We’re finding that ageing isn’t the irreversible affliction that we thought it was,” Prof Sinclair said. “Some of us could live to 150, but we won’t get there without more research.”



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Finally, falling pitch drop caught on camera after a 69-year wait

Finally, falling pitch drop caught on camera after a 69-year wait | Amazing Science |

It took 69 years, but at last we've seen the pitch drop. One of the world's longest-running experiments climaxed last week, when a finger-sized bulb of pitch (bitumen) separated from its parent bulk and dropped into a beaker. For the first time ever, this fleeting event has been recorded on video.


The pitch drop experiment was set up at Trinity College Dublin, Ireland, in 1944. The original version of the experiment, at the University of Queensland in Australia, has been running since 1930, but various glitches have prevented that team from actually seeing a drop separate.


"No one has ever seen a drop fall anywhere in the world," says Trinity'sShane Bergin, whose webcam recorded the event on 11 July. "It's one of the oldest experiments – an oddity, a curiosity."


Pitch shatters if hit with a hammer at room temperature. Physicist Thomas Parnell set up the Queensland experiment to illustrate that, although it appears solid, pitch is actually an incredibly viscous liquid. (Recent experiments showed that the same is true for "Gorilla Glass", used in smartphones and tablet screens.)


The world's longest-running scientific experiment is about to drop into the headlines. For over 80 years, two physicists at the University of Queensland have been standing guard over the Pitch Drop Experiment. Now, the decade-awaited moment of truth is bearing down: a drop is about to fall.


In 1927, the first physics professor at the University of Queensland, Thomas Parnell, sought to demonstrate that some materials exhibit seemingly contradictory properties. Once used to seal the bottom of boats, tar pitch feels solid at room temperature and shatters like glass under a hammer blow. But, as Parnell has undeniably demonstrated, pitch is actually a very, very viscous fluid.

So one day, Parnell placed a block of tar pitch in a sealed funnel. Three years later, the pitch had settled into the bottom of the funnel and in 1930 the bottom of the funnel stem was cut.

The first drop fell in December, 1938!


It is something of an overstatement to say that the pitch has been dripping ever since. In 86 years, a total of eight drops have dripped, with about a decade between drop falls. Now, the ninth is about to drop, probably in 2013. If you're lucky, you may see what no one has seen before—no one has ever witnessed the drop fall.

John Mainstone, a physics professor at the University of Queensland and the experiment's current custodian, missed the last two drops by pure bad luck.


Awaiting the eighth drip from a business trip, Mainstone secured a video surveillance system to trail the elusive drop. Alas, the video feed failed precisely during the fall of the eighth pitch-drop. Listen to John Mainstone tell the story of the missed adventure on last week's Radio Lab.

Jan Peter van Zijl's curator insight, March 16, 2013 1:37 PM


Het langst lopende wetenschappelijke experiment: Pitch Drop Experiment.

Jan Peter van Zijl's curator insight, May 4, 2013 11:19 AM


Het traagste én langst-lopende experiment ter wereld staat weer volop in de belangstelling.

15maart13 werd het experiment al vermeld in de wetenschapsbijlagen van de kranten.

Nu weer -4mei13-! De negende druppel gaat eerdaags(!) vallen.


Het wordt steeds spannender in Brisbane (Australië). Nog nooit heeft iemand een druppel zien vallen. Nu wordt het experiment bewaakt met behulp van drie (!) webcams..


Pek lijkt een vaste stof, maar gedraagt zich als een vloeistof.

Dat wordt ook wel gezegd over glas, maar dat verhaal is niet helemaal juist .... ;

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The genome of the HeLa cell line has been sequenced at last

The genome of the HeLa cell line has been sequenced at last | Amazing Science |
The HeLa cell genome is riddled with errors, raising questions about its continued use.


The research world’s most famous human cell has had its genome decoded, and it’s a mess. German researchers this week report the genome sequence of the HeLa cell line, which originates from a deadly cervical tumour taken from a patient named Henrietta Lacks. Established after Lacks died in 1951, HeLa cells were the first human cells to grow well in the laboratory. The cells have contributed to more than 60,000 research papers, the development of a polio vaccine in the 1950s and, most recently, an international effort to characterize the genome, known as ENCODE.

Previous work showed that HeLa cells, like many tumours, have bizarre, error-filled genomes, with one or more extra copies of many chromosomes. To get a closer look at these alterations, a team led by Lars Steinmetz, a geneticist at the European Molecular Biology Laboratory in Heidelberg, Germany, sequenced the popular 'Kyoto' version of the cell line and compared the sequence with that of a reference human genome.


Steinmetz’s team confirmed that HeLa cells contain one extra version of most chromosomes, with up to five copies of some. Many genes were duplicated even more extensively, with four, five or six copies sometimes present, instead of the usual two.  Furthermore, large segments of chromosome 11 and several other chromosomes were reshuffled like a deck of cards, drastically altering the arrangement of the genes.


Without the genome sequence of Lacks’ healthy cells or that of her original tumor, it is difficult to trace the origin of these alterations. Steinmetz points out that other cervical tumours have massive rearrangements on chromosome 11, so the changes in the HeLa cell may have contributed to Lacks’ tumor.


Having been replicating in labs around the world for six decades, HeLa cells have also accrued errors not present in the original tumor DNA. Moreover, not all HeLa cells are identical, and Steinmetz says that it would be interesting to chart the cell’s evolution. Whatever their origin, the genetic changes raise questions over the widespread use of HeLa cells as models for human cell biology, Steinmetz says. For instance, his team found that around 2000 genes are expressed at levels higher than those of normal human tissues because of the duplications. Alternative cell lines, such as induced pluripotent stem cells generated from patient skin cells, offer a more accurate window on human biology, he says.

In recent years, the genomes of many cervical tumors have been sequenced, and so it should be possible to see how these compare with the HeLa genome. Steinmetz also points out that thousands of research papers based on HeLa cells, along with HeLa resources such as genetically manipulated lines and now a genome, means that labs will continue to stock the cells, even if they are not a perfect model of human biology. “These are not going to go out of fashion over the next 10 years,” he says. "I’m not sure where we’re going to be 20 years from now."

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More HIV patients 'cured': first a baby, now 14 adults

More HIV patients 'cured': first a baby, now 14 adults | Amazing Science |

A small group of adults given rapid drug treatment after HIV infection no longer need drugs to keep the virus in check. Last week, a baby was reported to have been "functionally cured" of HIV after receiving a three-drug regime of ARVs almost immediately after birth. Early treatment seems crucial, but does not guarantee success.


Asier Sáez-Cirión of the Pasteur Institute's unit for regulation of retroviral infections in Paris analysed 70 people with HIV who had been treated with antiretroviral drugs (ARVs) between 35 days and 10 weeks after infection – much sooner than people are normally treated.


All of the participants' drug regimes had been interrupted for one reason or another. For example, some people had made a personal choice to stop taking the drugs, others had been part of a trial of different drug protocols.


Most of the 70 people relapsed when their treatment was interrupted, with the virus rebounding rapidly to pre-treatment levels. But 14 of them – four women and 10 men – were able to stay off of ARVs without relapsing, having taken the drugs for an average of three years.


On average, the 14 adults have been off medication for seven years. One has gone 10-and-a-half years without drugs. "It's not eradication, but they can clearly live without pills for a very long period of time," says Sáez-Cirión. The 14 adults still have traces of HIV in their blood, but at such low levels that their body can naturally keep it in check without drugs.


Sáez-Cirión warns that rapid treatment doesn't work for everyone, but the new study reinforces the conclusion that early intervention is important.

"There are three benefits to early treatment," says Sáez-Cirión. "It limits the reservoir of HIV that can persist, limits the diversity of the virus and preserves the immune response to the virus that keeps it in check."


Further analysis confirmed that the 14 adults were not "super-controllers" – the 1 per cent of the population that are naturally resistant to HIV – since they lack the necessary protective genes. Also, natural controllers rapidly suppress their infections, whereas these 14 mostly had severe symptoms which led to their early treatment. "Paradoxically, doing badly helped them do better later," says Sáez-Cirión.


The researchers are trying to identify additional factors that could explain why early intervention only works on some people, hopefully extending the scope for more functional cures. "This whole area is fascinating, and we've been looking very closely at issues of early initiation of treatment, and the potential for functional cures," says Andrew Ball, senior adviser on HIV/AIDS strategy at the World Health Organization in Geneva.


"The big challenge is identifying people very early in their infection," says Ball, adding that many people resist testing because of the stigma and potential discrimination. "There's a good rationale for being tested early, and the latest results may give some encouragement to do that," he says.

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The Future Of Education Eliminates The Classroom -- Because The World Is Your Class

The Future Of Education Eliminates The Classroom -- Because The World Is Your Class | Amazing Science |

Massive Open Online Courses (MOOCs) might seem like best way to use the Internet to open up education, but you’re thinking too small. Technology can turn our entire lives into learning experiences.

Socialstructed learning is an aggregation of microlearning experiences drawn from a rich ecology of content and driven not by grades but by social and intrinsic rewards. The microlearning moment may last a few minutes, hours, or days, if you are absorbed in reading something, tinkering with something, or listening to something from which you just can’t walk away. Socialstructed learning may be the future, but the foundations of this kind of education lie far in the past. Leading philosophers of education --from Socrates to Plutarch, Rousseau to Dewey-- talked about many of these ideals centuries ago. Today, we have a host of tools to make their vision finally a reality.

Think of a simple augmented reality apps on the iPhone such as Yelp Monocle. When you point the phone’s camera toward a particular location, it displays “points of interest” in that location, such as restaurants, stores, and museums. Augmented reality -- but this is just the beginning. What if, instead of restaurant and store information, we could access historical, artistic, demographic, environmental, architectural, and other kinds of information embedded in the real world? All our cultural inheritance is only a click away.


This is exactly what a project from USC and UCLA called HyperCities is doing: layering historical information on the actual city terrain. As you walk around with your cell phone, you can point to a site and see what it looked like a century ago, who lived there, what the environment was like. Not interested in architecture, passionate about botany and landscaping instead? The Smithsonian’s free iPhone and iPad app, Leafsnap, responds when you take a photo of a tree leaf by instantly searching a growing library of leaf images amassed by the Smithsonian Institution. In seconds, it displays a likely species name along with high-resolution photographs of and information on the tree’s flowers, fruit, seeds, and bark. We are turning each pixel of our geography into a live textbook and a live encyclopedia.

So look beyond MOOCs (Massive Open Online Courses) in thinking about the future education. In our focus on MOOCs and how they are likely to disrupt existing classrooms and educational institutions, particularly colleges and universities, we are missing the much larger story. Today’s obsession with MOOCs is a reminder of the old forecasting paradigm: In the early stages of technology introduction we try to fit new technologies into existing social structures in ways that have become familiar to us.


MOOCs today are our equivalents of early TV, when TV personalities looked and sounded like radio announcers (or often were radio announcers). People are thinking the same way about MOOCs, as replacements of traditional lectures or tutorials, but in online rather than physical settings. In the meantime, a whole slew of forces is driving a much larger transformation, breaking learning (and education overall) out of traditional institutional environments and embedding it in everyday settings and interactions, distributed across a wide set of platforms and tools. They include a rapidly growing and open content commons (Wikipedia is just one example), on-demand expertise and help (from Mac Forums to Fluther, Instructables, and WikiHow), mobile devices and geo-coded information that takes information into the physical world around us and makes it available any place any time, new work and social spaces that are, in fact, evolving as important learning spaces (TechShop, Meetups, hackathons, community labs).


We are moving away from the model in which learning is organized around stable, usually hierarchical institutions (schools, colleges, universities) that, for better and worse, have served as the main gateways to education and social mobility. Replacing that model is a new system in which learning is best conceived of as a flow, where learning resources are not scarce but widely available, opportunities for learning are abundant, and learners increasingly have the ability to autonomously dip into and out of continuous learning flows.

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Every School Used To Have It --Chalk : What Is It Made Of? Coccolithophores!

Every School Used To Have It --Chalk : What Is It Made Of? Coccolithophores! | Amazing Science |

When a school teacher writes her name on a blackboard on the first day of class, what she's really doing is crushing the skeletons of terribly ancient earthlings into a form that spells out the name "Mrs. ...".


A piece of chalk, when you think about too much, is a miracle. What is it, exactly? Well, if you look under a microscope, as British naturalist Thomas Huxley did in the 1860s, what you see is this (see figure). Chalk is composed of extremely small white globules. They look, up close, like snowballs made from brittle paper plates. Those plates, it turns out, are part of ancient skeletons that once belonged to roundish little critters that lived and floated in the sea, captured a little sunshine and carbon, then died and sank to the bottom. There still are trillions of them floating about in the oceans today, sucking up carbon dioxide, pocketing the carbon. Over the millennia, so many have died and plopped on top of each other, the weight of them and the water above has pressed them into a white blanket of rock, entirely composed of teeny skeletons. Scientists call these ancient plates "coccoliths." Technically, they are single-celled phytoplankton algae.


Chalk doesn't proclaim itself. It is usually out of view, buried in the ground below. Every so often, when a highway is being carved through a mountain, or when the sea and wind erode the side of a hill, that's when the green cover comes off, then you can see it. The White Cliffs of Dover are all chalk, piled hundreds of feet high.


In 1853, when the transatlantic cable was being laid, engineers would occasionally yank thick loops of wire up 10,000 feet from the ocean bottom, and every time, they found the same coating of white muck: chalk again. It turns out, writes biologist Bernd Heinrich, "the Atlantic mud, which stretches over a huge plain thousands of square miles, is raw chalk."

“A great chapter of the history of the world is written in chalk.


Since then geologists have found a chalk layer stretching 3,000 miles across Europe into Asia. It's under France, Germany, Russia, Egypt, Syria. How did it get there?


That, said Thomas Huxley (who first saw those teeny skeletons under his microscope) is one of the "most startling conclusions of physical science." In 1868, he gave a lecture to the "working men of Norwich" where he declared that "a great chapter of the history of the world is written in chalk."



Ron Peters's curator insight, December 10, 2013 2:32 PM

Chalks Undersea Connection...

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NASA Starts Making its own plutonium-238 to be used in a radioisotope thermoelectric generator for space missions

NASA Starts Making its own plutonium-238 to be used in a radioisotope thermoelectric generator for space missions | Amazing Science |

After a 25-year hiatus, the Unites States has produced its first non-weapons grade plutonium needed to power space probes when solar energy won’t suffice.

NASA has been using a radioactive material called plutonium-238 to power its deep space probes since the 1970s. The nuclear-powered spacecraft include the twin Voyager probes, now heading out of the solar system, the Mars Viking landers, the Galileo and Cassini missions at Jupiter and Saturn, respectively, and most recently the Mars Curiosity rover, which is seven months into a planned two-year mission.

The plutonium naturally radiates heat as it decays, which can be converted into electricity with a device known as a radioisotope thermoelectric generator, or RTG. The U.S. produced its own supply of plutonium-238 until the late 1980s, when the Department of Energy’s reactors at the Savannah River Site in South Carolina, where the plutonium was generated, were shut down for safety and environmental issues. NASA then turned to Russia to purchase plutonium, but that supply line dried up in 2010. Since then, the Department of Energy (DOE), working in collaboration with NASA, has been trying to restart domestic production of plutonium-238. Early results are promising.


After encapsulating the radioactive starter material neptunium, putting it into a reactor at Oak Ridge National Laboratory in Tennessee and radiating it for a month, the DOE did successfully generate plutonium, said Jim Green, chief of NASA’s planetary science division.


“This is a major step forward,” Green said at recent Mars exploration planning group meeting. “We’re expecting reports from (the DOE) later this year on a complete schedule that would then put plutonium on track to be generated at about 1.5 kilograms (3.3 pounds) a year, so it’s going quite well,” Green said. The fresh plutonium has the added benefit of reviving NASA's small and decaying supply of older plutonium still in storage.


“It fairly old -- more than 20 years,” Green said, “When we add newly generated plutonium through this process to the older plutonium in a mixture of one new-to-two old units, we can actually revive that and get he energy density we need. So for every 1 kilogram (2.2 pounds), we really revive two other kilograms of the older plutonium by mixing it.”


“It’s a critical part of our process to be able to utilize our existing supply at the energy density that we want it at,” he added. Among the upcoming missions that likely will need nuclear power is a follow-on Mars rover based on Curiosity’s design and now-proven sky crane landing system.


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'The Hoyle State' -- Is the Universe Fine-Tuned for the Formation of Carbon and Oxygen?

'The Hoyle State' -- Is the Universe Fine-Tuned for the Formation of Carbon and Oxygen? | Amazing Science |

Is the Universe fine-tuned for life? A team of physicists is looking at the conditions necessary to the formation of carbon and oxygen two elements in the universe that are the foundation of life as we currently know it. They’ve found that when it comes to supporting life, the universe leaves very little margin for error.


“The Hoyle state of carbon is key,” says NC State physicist Dean Lee. “If the Hoyle state energy was at 479 keV or more above the three alpha particles, then the amount of carbon produced would be too low for carbon-based life. The same holds true for oxygen,” he adds. “If the Hoyle state energy were instead within 279 keV of the three alphas, then there would be plenty of carbon. But the stars would burn their helium into carbon much earlier in their life cycle. As a consequence, the stars would not be hot enough to produce sufficient oxygen for life. In our lattice simulations, we find that more than a 2 or 3 percent change in the light quark mass would lead to problems with the abundance of either carbon or oxygen in the universe.”


Both carbon and oxygen are produced when helium burns inside of giant red stars. Carbon-12, an essential element we’re all made of, can only form when three alpha particles, or helium-4 nuclei, combine in a very specific way. The key to formation is an excited state of carbon-12 known as the Hoyle state, and it has a very specific energy – measured at 379 keV (or 379,000 electron volts) above the energy of three alpha particles. Oxygen is produced by the combination of another alpha particle and carbon.


The international team -- Lee and German colleagues Evgeny Epelbaum, Hermann Krebs, Timo Laehde and Ulf-G. Meissner-- had previously confirmed the existence and structure of the Hoyle state with a numerical lattice that allowed the researchers to simulate how protons and neutrons interact. These protons and neutrons are made up of elementary particles called quarks. The light quark mass is one of the fundamental parameters of nature, and this mass affects particles’ energies.


In new lattice calculations done at the Juelich Supercomputer Centre the physicists found that just a slight variation in the light quark mass will change the energy of the Hoyle state, and this in turn would affect the production of carbon and oxygen in such a way that life as we know it wouldn’t exist.carbon and oxygen production and the viability of carbon-based life.

In new lattice calculations done at the Juelich Supercomputer Center the physicists found that just a slight variation in the light quark mass will change the energy of the Hoyle state, and this in turn would affect the production of carbon and oxygen in such a way that life as we know it wouldn’t exist.

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Whole brain cellular-level activity mapping in one second

Whole brain cellular-level activity mapping in one second | Amazing Science |

Neuroscientists at Howard Hughes Medical Institute have mapped the activity of nearly all the neurons in a vertebrate brain at cellular resolution, with signficant implications for neuroscience research and projects like the proposed Brain Activity Map (BAM).


Fast volumetric imaging of the larval zebrafish brain with light-sheet microscopy (credit: Misha B Ahrens, Philipp J Keller/Nature Methods)

The researchers used high-speed light sheet microscopy to image the activity of 80% of the neurons in the brain (which is composed of ~100,000 neurons) of a fish larva at 0.8 Hz (an image every 1.3 seconds), with single-cell resolution.


This represents the first technology that achieves whole brain imaging of a vertebrate brain at cellular resolution with speeds that approximate neural activity patterns and behavior, as Nature Methodsmethagora blog noted.

The authors saw correlated activity patterns at the cellular level that spanned large areas of the brain — pointing to the existence of broadly distributed functional circuits.


The next steps will be to determine the causal role that these circuits play in behavior — something that will require improvements in the methods for 3D optogenetics, the blog said. Obtaining the detailed anatomical map of these circuits will also be key to understand the brain’s organization at its deepest level.

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The Mariana trench, deepest point in the ocean is teeming with life

The Mariana trench, deepest point in the ocean is teeming with life | Amazing Science |

Hollywood director James Cameron found little evidence of life when hedescended nearly 11,000 metres to the deepest point in the world's oceans last year. If only he had taken a microscope and looked just a few centimetres deeper.


Ronnie Glud at the University of Southern Denmark in Odense, and his colleagues, have discovered unusually high levels of microbial activity in the sediments at the site of Cameron's dive – Challenger Deep at the bottom of the western Pacific's Mariana Trench.


Glud's team dispatched autonomous sensors and sample collectors into the trench to measure microbial activity in the top 20 centimetres of sediment on the sea bed. The pressure there is almost 1100 times greater than at the surface. Finding food, however, is an even greater challenge than surviving high pressures for anything calling the trench home.


Any nourishment must come in the form of detritus falling from the surface ocean, most of which is consumed by other organisms on the way down. Only 1 per cent of the organic matter generated at the surface reaches the sea floor's abyssal plains, 3000 to 6000 metres below sea level. So what are the chances of organic matter making it even deeper, into the trenches that form when one tectonic plate ploughs beneath another?


Surprisingly, the odds seem high. Glud's team compared sediment samples taken from Challenger Deep and a reference site on the nearby abyssal plain. The bacteria at Challenger Deep were around 10 times as abundant as those on the abyssal plain, with every cubic centimetre of sediment containing 10 million microbes. The deep microbes were also twice as active as their shallower kin.


These figures make sense, says Glud, because ocean trenches are particularly good at capturing sediment. They are broad as well as deep, with a steep slope down to the deepest point, so any sediment falling on their flanks quickly cascades down to the bottom in muddy avalanches. Although the sediment may contain no more than 1 per cent organic matter, so much of it ends up at Challenger Deep that the level of microbial activity shoots up.


"There is much more than meets the eye at the bottom of the sea," says Hans Røy, at Aarhus University in Denmark. Last year, he studied seafloor sediments below the north Pacific gyre – an area that, unlike Challenger Deep, is almost devoid of nutrients. Remarkably, though, even here Røy found living microbes.

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Red blood cell production relies on white blood cell help

Red blood cell production relies on white blood cell help | Amazing Science |

Red blood cell production in the bone marrow is a precarious process. Too few RBCs and you can become anemic; too many and you could be suffering from polycythemia vera, a rare, so-called ‘myeloproliferative’ genetic disorder marked by an abnormally high RBC count. Now, researchers have identified a surprising player in the regulation of RBC production under these disease conditions. Reporting online today in Nature Medicine, two independent teams describe the pivotal role of macrophages—amoeba-like white blood cells responsible for digesting harmful foreign microbes and removing old or dying cells—for generating RBCs in both anemic and over-proliferative conditions.


In one study, geneticist Stefano Rivella and his colleagues at the Weill Cornell Medical College in New York administered a drug that selectively kills macrophages in a mouse model of polycythemia vera. In these mice, RBCs are generated at almost twice the normal amount, leading to viscous blood, enlarged organs and increased risk for strokes and heart disease. The drug, called clodronate, appeared to cure these symptoms, however, drastically lowering macrophage population and bringing RBC counts back to normal levels compared with a control group of animals treated with saline.


These findings were independently confirmed by Paul Frenette, a stem cell biologist at the Albert Einstein College of Medicine, also in New York. His team used a genetically modified mouse in which macrophages expressed a gene that made them vulnerable to a toxin and arrived at similar conclusions. “When we depleted macrophages in this disease, we actually corrected the disease,” Frenette says. “Maybe this could be a new therapy for this type of disease, which is unexpected.”


Rivella and his group also studied beta-thalassemia, another inherited blood disorder characterized by lowered RBC counts and severe anemia. Paradoxically, RBC precursor cells are actually overproduced in this disease, but they never fully mature and subsequently build up in the spleen and liver, leading to organ enlargement. When treated with clodronate, however, genetically modified mice with a beta-thalassemia-like condition showed statistically significant increased RBC counts. Rivella chalks this effect up to reduced precursor cell numbers and organ size, allowing better circulation of healthy cells. “Take out the macrophages and the ability of RBC precursors to expand and proliferate is decreased,” he says.


Interestingly, when normal mice were macrophage-depleted, there were no observable effects on RBC levels. Both Frenette and Rivella believe that this indicates macrophages modulate RBC production only during stress or abnormal conditions. The precise mechanisms for this new stress-related role remain opaque, although Frenette’s group showed evidence that an adhesion molecule known as VCAM1 and a bone marrow protein known as BMP 4 could play a part.


For now, patients suffering from disorders such as polycythemia vera and beta-thalassemia will have to wait until these mechanisms are fully understood. Macrophage depletion in both studies was temporary, as cessation of treatment led to macrophage and symptom recovery. In addition, macrophage depletion can have severe consequences in immunity, bone formation and many other systems. Clodronate “is a really great drug to do these experiments, but it’s not something I’d suggest to patients,” says Rivella.

On the flipside, boosting macrophage levels could prove beneficial in some settings. For instance, Frenette’s group gave mice bone marrow transplants and showed that wiping out macrophage levels significantly delayed RBC recovery. The finding, Frenette says, “would suggest that methods to improve macrophage functional recovery might be useful in a situation such as bone marrow transplantation where you need to make more red blood cells faster.”

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Astronomers Detect Extremely Rare Triple Quasar

Astronomers Detect Extremely Rare Triple Quasar | Amazing Science |

By combining multiple telescope observations and advanced modeling, a multinational team of astronomers has discovered an extremely rare triple quasar system – only the second such object ever found.


Quasars are powerful sources of energy that sit in the center of a galaxy, surrounding a black hole. In systems with multiple quasars, the bodies are held together by gravity and are believed to be the product of galaxies colliding.


It is very difficult to observe triplet quasar systems, because of observational limits that prevent researchers from differentiating multiple nearby bodies from one another at astronomical distances.


The team combined observations from ESO’s New Technology Telescope at La Silla, Chile, and from the Calar Alto Observatory in Spain with advanced modelling. This enabled them to find the quasar, labeled QQQ J1519+0627.


The light from this object has traveled 9 billion light years to reach us, which means the light was emitted when the Universe was only a third of its current age.


Advanced analysis confirmed that what the team found was indeed three distinct sources of quasar energy and that the phenomenon is extremely rare.


“Honing our observational and modeling skills and finding this rare stellar phenomenon will help us understand how cosmic structures assemble in our universe and the basic processes by which massive galaxies form,” said Dr Michele Fumagalli from Princeton University and Carnegie Observatories.


Two members of the triplet are closer to each other than the third. This means that the system could have been formed by interaction between the two adjacent quasars, but was probably not triggered by interaction with the more-distant third quasar. Furthermore, no evidence was seen of any ultra-luminous inferred galaxies, which is where quasars are commonly found. As a result, the astronomers propose that this triplet quasar system is part of some larger structure that is still undergoing formation.


“Further study will help us figure out exactly how these quasars came to be and how rare their formation is,” said lead author Dr Emanuele Farina of the Universita degli Studi dell’Insubria and the Universit`a degli Studi di Milano-Bicocca.



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Breakthrough Research Shows Chemical Reactions in Real Time

Breakthrough Research Shows Chemical Reactions in Real Time | Amazing Science |

The ultrafast, ultrabright X-ray pulses of the Linac Coherent Light Source (LCLS) have enabled unprecedented views of a catalyst in action, an important step in the effort to develop cleaner and more efficient energy sources.


Scientists at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory used LCLS, together with computerized simulations, to reveal surprising details of a short-lived early state in a chemical reaction occurring at the surface of a catalyst sample. The study offers important clues about how catalysts work and launches a new era in probing surface chemistry as it happens.


"To study a reaction like this in real time is a chemist's dream," said Anders Nilsson, deputy director for the Stanford and SLAC SUNCAT Center for Interface Science and Catalysis and a leading author in the research, published March 15 in Science. "We are really jumping into the unknown."


In the LCLS experiment, researchers looked at a simple reaction in a crystal composed of ruthenium, a catalyst that has been extensively studied, in reaction with carbon monoxide gas. The scientists zapped the crystal's surface with a conventional laser, which caused carbon monoxide molecules to begin to break away. They then probed this state of the reaction using X-ray laser pulses, and observed that the molecules were temporarily trapped in a near-gas state and still interacting with the catalyst.


"We never expected to see this state," Nilsson said. "It was a surprise."


Not only was the experiment the first to confirm the details of this early stage of the reaction, it also found an unexpectedly high share of molecules trapped in this state for far longer than what was anticipated, raising new questions about the atomic-scale interplay of chemicals that will be explored in future research.

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3D-Printed Skull Implant Ready for Operation

3D-Printed Skull Implant Ready for Operation | Amazing Science |

3D printing technology has helped replace 75 percent of a patient's skull with the approval of U.S. regulators. The 3D-printed implant can replace the bone in people's skulls damaged by disease or trauma, according to Oxford Performance Materials. The company announced it had received approval from the U.S. Food and Drug Administration for its skull implant on Feb. 18, 2013— a decision that led to the first U.S. surgical operation on March 4.

"We see no part of the orthopedic industry being untouched by this," said Scott DeFelice, president of Oxford Performance Materials.

DeFelice's company is already selling 3D-printed implants overseas as a contract manufacturer. But the FDA decision has opened the door for U.S. operations using the implants. [Video: A 3D Printer of Your Own]

3D printing's advantage comes from taking the digitally scanned model of a patient's skull and "printing" out a matching 3D object layer by layer. The precise manufacturing technique can even make tiny surface or edge details on the replacement part that encourage the growth of cells and allow bone to attach more easily.


About 300 to 500 U.S. patients could use skull bone replacements every month, according to DeFelice. The possible patients include people with cancerous bone in their skulls, as well as car accident victims and U.S. military members suffering from head trauma.

Deb Nystrom, REVELN's curator insight, March 16, 2013 3:36 AM

What are the implications?  For 3-D printing, it seems vast. ~ Deb

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Phytoplankton, which produces half the world's oxygen, has declined 40% since 1950

Phytoplankton, which produces half the world's oxygen, has declined 40% since 1950 | Amazing Science |

Two weeks ago, a group of sailors off the coast of New Zealand leaned over the side of their boat, dropped a contraption into the Pacific Ocean and watched it disappear. Using an app they’d downloaded to a smartphone, they logged a reading from the underwater device, along with their GPS location and the water temperature. In just a few minutes’ time, they had become the first participants in a new program launched by the UK’s Plymouth University Marine Institute which allows citizen scientists to help climatologists study the effects of climate change on the oceans.


The Kiwi sailors were measuring the concentration of phytoplankton, a microorganism that lives at the sea surface. Phytoplankton, also called microalgae, produce half of the oxygen in the air we breathe and are responsible for 50 percent of the Earth’s photosynthesis. Whales, jellyfish, shrimp and other marine life feast on it, making it a critical part of the marine food chain.


Phytoplankton require a certain water temperature to thrive (this varies regionally), and without these favored conditions, they either decrease in number or migrate in search of optimal water. As the upper levels of the Earth’s oceans have warmed by 0.59 degrees Fahrenheit in the past century, the amount of phytoplankton worldwide dips by roughly 1 percent each year, according to a 2010 study published in the journal Nature.

In fact, phytoplankton concentrations have decreased by a total of 40 percent since 1950. The decline joins coral bleaching, sea-level rise, ocean acidification and a slowing of deep-water circulation (which effects water temps and weather patterns) as the known tolls of climate change on the oceans.


This drop in phytoplankton population is troubling because of this organism’s role in the marine food web. “Despite their microscopic size, phytoplankton… are harbingers of climate change in aquatic systems,” wrote the authors of a 2011 study on phytoplankton and climate change published in the journal Proceedings of the Royal Society. So understanding how other sea creatures will fare as climate changes depends on how drastically phytoplankton levels continue to drop.

Peter Phillips's comment, March 15, 2013 4:30 PM
Sounds alarmist, could we simply be observing change in ocean currents and distribution?
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Scientists have managed to grow brand new teeth complete with roots using cells from human adult gum tissue

Scientists have managed to grow brand new teeth complete with roots using cells from human adult gum tissue | Amazing Science |
Researchers mix cells from human adult gum tissue with tooth-inducing cells from mouse embryos to grow new hybrid teeth complete with roots.


Cells taken from adult human gums can be combined with cells from the molars of fetal mice to form teeth with viable roots, according to research published this week in the Journal of Dental Research. The method remains a long way from clinical use, but the findings represent a step toward the goal of growing bioengineered replacements for lost teeth.


Teeth develop when embryonic epithelial cells in the mouth combine with mesenchymal cells derived from the neural crest. Previous studies have shown that these cells can be combined in the lab to formal normal teeth, but the challenge was to find non-embryonic source of the cells that could be used in the clinic.


To test one such source, a team lead by King’s College London stem cell biologist Paul Sharpe extracted epithelial cells from the gums of adult humans, cultured them in the lab, and mixed them with mesenchymal tooth cells derived from embryonic mice. After a week, the researchers transplanted this mixture into the protective tissue around the kidneys of living mice, where some of the cells developed into hybrid human/mouse teeth containing dentine and enamel, and with growing roots.


The research showed that the epithelial cells from adult human gum tissue responded to tooth-inducing signals from the embryonic mouse tooth mesenchyme, making the gum cells a realistic source for clinical use, said Sharpe in a press release. He added that “the next major challenge is to identify a way to culture adult human mesenchymal cells to be tooth-inducing, as at the moment we can only make embryonic mesenchymal cells do this.”

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Brain Researchers Can Detect Who We Are Thinking About

Brain Researchers Can Detect Who We Are Thinking About | Amazing Science |

Scientists scanning the human brain can now tell whom a person is thinking of, the first time researchers have been able to identify what people are imagining from imaging technologies.


Work to visualize thought is starting to pile up successes. Recently, scientists have used brain scans to decode imagery directly from the brain, such as what number people have just seen and what memory a person is recalling. They can now even reconstruct videos of what a person has watched based on their brain activity alone. Cornell University cognitive neuroscientist Nathan Spreng and his colleagues wanted to carry this research one step further by seeing if they could deduce the mental pictures of people that subjects conjure up in their heads.


“We are trying to understand the physical mechanisms that allow us to have an inner world, and a part of that is how we represent other people in our mind,” Spreng says. His team first gave 19 volunteers descriptions of four imaginary people they were told were real. Each of these characters had different personalities. Half the personalities were agreeable, described as liking to cooperate with others; the other half were less agreeable, depicted as cold and aloof or having similar traits. In addition, half these characters were described as outgoing and sociable extroverts, while the others were less so, depicted as sometimes shy and inhibited. The scientists matched the genders of these characters to each volunteer and gave them popular names like Mike, Chris, Dave or Nick, or Ashley, Sarah, Nicole or Jenny.


The researchers then scanned volunteers’ brains using functional magnetic resonance imaging (fMRI), which measures brain activity by detecting changes in blood flow. During the scans, the investigators asked participants to predict how each of the four fictitious people might behave in a variety of scenarios — for instance, if they were at a bar and someone else spilled a drink, or if they saw a homeless veteran asking for change.


“Humans are social creatures, and the social world is a complex place,” Spreng says. “A key aspect to navigating the social world is how we represent others.” The scientists discovered that each of the four personalities were linked to unique patterns of brain activity in a part of the organ known as the medial prefrontal cortex. In other words, researchers could tell whom their volunteers were thinking about.


“This is the first study to show that we can decode what people are imagining,” Spreng says. The medial prefrontal cortex helps people deduce traits about others. These findings suggest this region is also where personality models are encoded, assembled and updated, helping people understand and predict the likely behavior of others and prepare for the future.

Phillip Heath's curator insight, March 18, 2013 4:55 PM

Always interested in how brain research might impact education. The more we know, the more we affirm instinctively good practice. We know more about why it works. We also better know what we don't know. 

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Einstein for Everyone - March 14th is Einstein's Birthday

Einstein for Everyone - March 14th is Einstein's Birthday | Amazing Science |

The Einstein of popular thought is the young Einstein. This is the intellectual rebel of 1905 who, in one year, laid out the special theory of relativity and E=mc2, postulated the light quantum and used Brownian motion to make the case for the reality of atoms. These achievements were made prior to Einstein holding an academic position. He was then still a patent examiner in the Bern patent office. The years that followed brought Einstein a succession of ever more prestigious academic appointments; and, in the mid 1910s, he delivered his masterpiece, the general theory of relativity.


In all this, there was a real sense that Einstein was ahead of his peers, leading the way. The special theory of relativity was absorbed into the mainstream of physics fairly quickly. The general theory of relativity was not quite so readily accommodated. This was in part due to its burdensome mathematical demands of the theory, at least relative to the standards of mathematical expertise then found among physicists. But the tide was flowing with Einstein. When the eclipse expeditions of 1919 vindicated Einstein's theory and he became a popular hero, critics risked being seen as unimaginative reactionaries.


Einstein's work on the light quantum did not fare so well. It was regarded by many as an odd aberration from an otherwise brilliant mind. Even in the early 1920s, it was doubted by Niels Bohr, who had a decade before developed the first quantum model of the atom.


By the end of the 1920s, however, another Einstein began to emerge. As the quantum theory enjoyed success after success, Einstein found himself unconvinced. He took on the role of critic, complaining that the new quantum theory, for all its virtues, could not be the final theory. This was Einstein's new place in the physics community for his final quarter century, ending with his death in 1955. He remained a revered figure. But he became increasingly isolated and marginalized, as he labored on his alternative theories with the help of a few assistants. In the years after his death, it became clear that Einstein's objection to quantum theory failed, but not, for the reasons articulated by his arch antagonist Niels Bohr.


The old Einstein is a recalcitrant Einstein, unwilling to swim with the new quantum tide that flooded over physics. We should not judge that harshly. No thinker can ever think purely new thoughts. We all sit at the junction of the old and the new. Einstein was one of the first of new physicists of the twentieth century. His discoveries and methods exercised a profound, defining influence on the development of twentieth century physics. However, there is also a strong sense in which he was one of the last of the nineteenth century physicists. Perhaps he was the greatest of them.

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March 14 is Pi Day, finding strength in numbers

March 14 is Pi Day, finding strength in numbers | Amazing Science |

March 14 is Pi Day, 3-14! Daniel Tammet painted this picture of how he sees the first 20 digits of pi. He set the European record for memorizing and reciting digits in 2004.

In Daniel Tammet's mind, three is a dotted green crescent moon shape, one is a sort of white sunburst and four is a blue boomerang. Every number has a distinct color and shape, making the number pi, which begins with 3.14, unfold like a beautiful poem.


For math enthusiasts around the world, March 14 (3-14) is Pi Day, honoring the number pi, which is the ratio of circumference to diameter of a circle. On Thursday, Tammet is promoting France's first Pi Day celebration at the Palace of Discovery science museum in Paris.

Tammet's relationship to this number is special: At age 25, he recited 22,514 digits of pi from memory in 2004, scoring the European record. For an audience at the Museum of the History of Science in Oxford, he said these numbers aloud for 5 hours and 9 minutes. Some people cried -- not out of boredom, but from sheer emotion from his passionate delivery.


"What my brain was doing was inventing a meaning, like a story," Tammet said. "What I did was make a poem or a novel out of pi, and took those colors and those emotions and used them to perceive patterns, or at least to perceive patterns in my mind that were memorable, that were meaningful to me."

Many people around the world have been interested enough in this number, or in memorization itself, to see how many digits they can bank. Pi has infinitely many digits with no discernible pattern, yet it mathematically explains the shape of all circles. This makes memorizing it a difficult, yet somehow meaningful, challenge. Serious pi memorizers such as Tammet have become fascinating subjects of study for scientists, too. They bring up fundamental questions about innate ability vs. learned skills. Are the brains of people with superior memory somehow different? Or can anyone learn thousands of random digits?

Superior memorizers, according to the research of K. Anders Ericsson, professor of psychology at Florida State University, have three special skills. They use knowledge and patterns that they already know to encode information in their long-term memory. They associate that information with retrieval cues, so that they can trigger the information again. They also get faster at all this by becoming better at encoding and retrieval through intense practice and effort.


This theory appears to explain Chao Lu, who set the current world record for pi recitation at 67,890 digits in 2005, at age 23. Creating associated meanings in numbers played a big part of that. He used mnemonics relating to the sounds of numbers as well as the shapes or meanings of particular digits and images, according to a 2009 study by Ericsson and colleagues.

Strangely, if presented with one number at a time, at one digit per second, Lu's recall is no better than the average person's, Ercisson and colleagues found. With that rate of presentation of numbers, he is forced to rehearse numbers in his head just like everyone else, Ericsson said.

But with large blocks of numbers, it's a different story. Lu and a previous pi-memorizing record holder, Hideaki Tomoyori, who recited 40,000 digits of pi, have said they linked words or images to groups of two, three or four numbers. Then they created stories connecting them. Tomoyori practiced daily, spending between 9,000 and 10,000 hours total memorizing before his recitation.


A rare case was Rajan Mahadevan, who set a record at 31,811 digits of pi and did not report using any mnemonics. When tested by researchers, it appeared he sequentially memorized numbers in blocks of 10. While some argued that Mahadevan may have an innate ability to memorize, Ericsson and colleagues found in their experiments with Mahadevan that he learned his unusual methods for memorizing numerical patterns after a thousand hours of practice.

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Alcohol consumption linked to increased brain uptake and oxidation of acetate in heavy drinkers

Alcohol consumption linked to increased brain uptake and oxidation of acetate in heavy drinkers | Amazing Science |

Alcohol is the most used recreational substance and one of the most widely abused drugs in the world. Alcohol use is characterized by CNS intoxication symptoms, impaired brain activity, poor motor coordination, and behavioral changes. The impairments in CNS activities are due to alcohol’s effect on synthesis, release, and signaling of neuron transmitters, including glutamate, GABA, and other neuron transmitters. Alcohol use also affects insulin sensitivity that regulates protein, carbohydrate, and fat metabolism. Chronic abuse of alcohol can result in tolerance and physical dependence. Although significant advances in understanding of alcohol’s effects have been made over the past decades, the pathogenesis of alcohol use and abuse is not fully understood. Understanding the mechanisms that lead to tolerance and dependence may give valuable insight into alcohol addiction and vulnerability and ultimately result in effective therapeutic intervention to facilitate detoxification.


When a person consumes ethanol, the body quickly begins to convert it to acetic acid, which circulates in the blood and can serve as a source of energy for the brain and other organs. This recently conducted study used 13C magnetic resonance spectroscopy to test whether chronic heavy drinking is associated with greater brain uptake and oxidation of acetic acid, providing a potential metabolic reward or adenosinergic effect as a consequence of drinking. Seven heavy drinkers, who regularly consumed at least 8 drinks per week and at least 4 drinks per day at least once per week, and 7 light drinkers, who consumed fewer than 2 drinks per week were recruited. The subjects were administered [2-13C]acetate for 2 hours and scanned throughout that time with magnetic resonance spectroscopy of the brain to observe natural 13C abundance of N-acetylaspartate (NAA) and the appearance of 13C-labeled glutamate, glutamine, and acetate. Heavy drinkers had approximately 2-fold more brain acetate relative to blood and twice as much labeled glutamate and glutamine. The results show that acetate transport and oxidation are faster in heavy drinkers compared with that in light drinkers. Our finding suggests that a new therapeutic approach to supply acetate during alcohol detoxification may be beneficial.

 In brain, glucose is the major supply of mitochondrial energy oxidation; however, acetate can also be used as an alternative energy source, and it is almost exclusively used by astrocytes. Heavy alcohol drinking has been reported to lead to hypoglycemia. Previously, studies on acetate metabolism of patients with diabetes who had previous recurrent hypoglycemia and healthy rats that underwent 3 days of antecedent recurrent hypoglycemia showed increased brain acetate transport and oxidation. Although acetate metabolism has been characterized in situations other than drinking, links between acetate metabolism and alcohol consumption are not clear. Recent data show that alcohol decreases brain glucose utilization and increases acetate uptake. Thus, one hypothesis is: upon chronic heavy alcohol intake, brain can use more acetate as a source of energy. The ethanol-based elevation of blood acetate persists for up to 24 hours, so heavy drinkers are exposed to high levels of acetate for long periods of times, and dependent drinkers likely always have elevated acetate. If acetate consumption by brain is higher, then adenosine effects can be expected to be enhanced. Faced with persistent elevation of adenosine, the brain likely adapts, and during withdrawal, the loss of adenosine may contribute to symptoms.

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