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Scooped by Dr. Stefan Gruenwald!

The brain’s visual data-compression algorithm

The brain’s visual data-compression algorithm | Amazing Science |
Data compression in the brain: When the primary visual cortex processes sequences of complete images and images with missing elements --- here vertical

Researchers have assumed that visual information in the brain was transmitted almost in its entirety from its entry point, the primary visual cortex (V1). “We intuitively assume that our visual system generates a continuous stream of images, just like a video camera,” said Dr. Dirk Jancke from the Institute for Neural Computation at Ruhr University.

“However, we have now demonstrated that the visual cortex suppresses redundant information and saves energy by frequently forwarding image differences,” similar to methods used for video data compression in communication technology.

Using recordings in cat visual cortex, Jancke and associates recorded the neurons’ responses to natural image sequences such as vegetation, landscapes, and buildings. They created two versions of the images: a complete one, and one in which they had systematically removed vertical or horizontal contours.

If these individual images were presented at 33Hz (30 milliseconds per image), the neurons represented complete image information. But at 10Hz (100 milliseconds), the neurons represented only those elements that were new or missing, that is, image differences.

To monitor the dynamics of neuronal activities in the brain in the millisecond range, the scientists used voltage-dependent dyes. Those substances fluoresce when neurons receive electrical impulses and become active, measured across a surface of several square millimeters. The result is a temporally and spatially precise record of transmission processes within the neuronal network.

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Mutation in plant flowering hormone postpones when a plant stops producing flowers, yielding many more fruits

Mutation in plant flowering hormone postpones when a plant stops producing flowers, yielding many more fruits | Amazing Science |

Cold Spring Harbor researchers announced that they have determined a way to dramatically increase tomato production. Their research has revealed a genetic mechanism for hybrid vigor, a property of plant breeding that has long been exploited to boost yield.

Every gardener knows the look of a ripe tomato. That bright red color, that warm earthy smell, and the sweet juicy flavor are hard to resist. But commercial tomato plants have a very different look from the backyard garden variety, which can grow endlessly under the right conditions to become tall and lanky. Tomatoes that will be canned for sauces and juice are harvested from plants that stop growing earlier than classic tomato varieties, and are therefore more like bushes. While the architecture of these compact bushy plants allows mechanical harvesters to reap the crop, the early end of growth means that each plant produces fewer fruits than their home garden cousins.

But what if commercial tomato growers could coax plants into producing more fruit without sacrificing that unique and necessary bushy plant shape? Today, CSHL researchers announced that they have determined a way to accomplish this. Their research has revealed one genetic mechanism for hybrid vigor, a property of plant breeding that has been exploited to boost yield since the early 20th century. Teasing out the hidden subtleties of a type of hybrid vigor involving just one gene has provided the scientists with means to tweak the length of time that bushy tomato varieties can produce flowers. In these plants, longer flowering time substantially raises fruit yield.

First identified at CSHL by George Shull in 1908, hybrid vigor – or heterosis, as biologists call it – involves interbreeding genetically distinct plants to generate offspring more robust than either inbred parent. It has been used for decades to improve agricultural productivity, but scientists have long debated how and why it works.

They found that bushy plants with a mutation in one of the two copies of the florigen gene, producing half as much florigen as plants without the mutation do, postpone the moment when they stop producing flowers.

This, in turn, leads to many more fruits overall. "This is because," Lippman explains, "bushy tomato varieties are highly sensitive to the amount, or dosage, of the florigen hormone, which alters plant architecture – that is, how many flowers can form before growth ends. These discoveries lead to an exciting prediction: that it may be possible to tweak florigen levels to increase yields even further."

Lippman's team also studied florigen mutants in another plant, the crucifer weed known as Arabidopsis that is a cousin of crops like broccoli and cauliflower. Although they did not see the same increase in yield, they did observe similar changes in plant architecture because of florigen dosage sensitivities. These results suggest that it may be possible to manipulate florigen in a wide variety of flowering species to increase yields.


"Tomato Yield Heterosis is Triggered by a Dosage Sensitivity of the Florigen Pathway that Fine-Tunes Shoot Architecture" appears online in PLOS Genetics on December 26, 2013. The authors are: Ke Jiang, Katie Liberatore, Soon Ju Park, John Alvarez, and Zach Lippman. []

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Engineer designs self-powered nanoscale devices that never need new batteries

Engineer designs self-powered nanoscale devices that never need new batteries | Amazing Science |

It's relatively simple to build a device capable of detecting wireless signals if you don't mind making one that consumes lots of power.

That's what Peter Kinget, a professor of electrical engineering, works on. He and his colleagues at the Engineering School are attempting to build self-powered systems using nanoscale devices that can transmit and receive wireless signals using so little power that their batteries never need replacing.

Rather, they rely on tiny bits of ambient solar energy to recharge themselves. Such energy efficiencies could dramatically cut down on the cost to operate a variety of these devices at once, while eliminating the need for maintenance. These sensors would only need to be installed once, and could remain in place functioning autonomously—practically until they wear out or disintegrate on their own.

Kinget's work is made possible by recent advances in nanotechnology—in general, he explains, the smaller the components of the tiny devices, the less energy is required to allow them to operate.

"We are using and exploiting the fact that power consumption—and the energy you need to do things—becomes very, very low as you pack more and more functionality into smaller and smaller spaces," he says.

"The bad news," he adds, "is that as the transistors become smaller, there are also clear disadvantages—nanoscale transistors are not as reliable, they cannot sustain large signal levels. The only way to deal with them is to come up with new design concepts."

Kinget's chips—some of them 100 times more energy efficient than most standard technologies—could be deployed for many different uses in future. Embedded in clothing, they could transmit the location of victims during disasters. They could be affixed to the walls of apartments across New York City and monitor heating or energy consumption patterns, which could then be analyzed to manage the heating systems or the power grid better. They could even collect and transmit data about humidity and temperature to computers designed to recognize and predict weather patterns.

Via Ioannis
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The Tortoise Beetles - Amazing Metallic Arthropods

The Tortoise Beetles - Amazing Metallic Arthropods | Amazing Science |

Tortoise beetles look almost manufactured.   Many tortoise beetles have transparent cuticles, the tough but flexible outer covering which gives the insect family its name protects the delicate creature within.  The living tissue is often metallic in color and can in some species even change color.  The combination is as diverse as it is extraordinary – many look like tiny robots assembled to infiltrate, the ultimate bug. Take a look in at the amazing variations of tortoise beetle our world holds.

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First structure of enzyme (tet) that modifies methylated cytosine modification

First structure of enzyme (tet) that modifies methylated cytosine modification | Amazing Science |
Scientists have obtained the first detailed molecular structure of a member of the Tet family of enzymes.

Cytosine residues in mammalian DNA occur in five forms: cytosine (C), 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). The ten-eleven translocation (Tet) dioxygenases convert 5mC to 5hmC, 5fC and 5caC in three consecutive, Fe(II)- and α-ketoglutarate-dependent oxidation reactions [1234]. The Tet family of dioxygenases is widely distributed across the tree of life [5], including in the heterolobosean amoeboflagellate Naegleria gruberi. The genome of Naegleria [6] encodes homologues of mammalian DNA methyltransferase and Tet proteins [7]. Here we study biochemically and structurally one of the Naegleria Tet-like proteins (NgTet1), which shares significant sequence conservation (approximately 14% identity or 39% similarity) with mammalian Tet1. Like mammalian Tet proteins, NgTet1 acts on 5mC and generates 5hmC, 5fC and 5caC. The crystal structure of NgTet1 in complex with DNA containing a 5mCpG site revealed that NgTet1 uses a base-flipping mechanism to access 5mC. The DNA is contacted from the minor groove and bent towards the major groove. The flipped 5mC is positioned in the active-site pocket with planar stacking contacts, Watson–Crick polar hydrogen bonds and van der Waals interactions specific for 5mC. The sequence conservation between NgTet1 and mammalian Tet1, including residues involved in structural integrity and functional significance, suggests structural conservation across phyla.

The finding is important for the field of epigenetics because Tet enzymes chemically modify DNA, changing signposts that tell the cell's machinery "this gene is shut off" into other signs that say "ready for a change."

Tet enzymes' roles have come to light only in the last five years; they are needed for stem cells to maintain their multipotent state, and are involved in early embryonic and brain development and in cancer.

Researchers led by Xiaodong Cheng, PhD, determined the structure of a Tet family member from Naegleria gruberi by X-ray crystallography. The structure shows how the enzyme interacts with its target DNA, bending the double helix and flipping out the base that is to be modified. "This base flipping mechanism is also used by other enzymes that modify and repair DNA, but we can see from the structure that the Tet family enzymes interact with the DNA in a distinct way," Cheng says. Mammalian Tet enzymes appear to have an additional regulatory domain that the Naegleria forms do not; understanding how that domain works will be a new puzzle opened up by having the Naegleria structure, Cheng says.

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Bizarre Silk Structures in the Amazon: Is it the Work of a Spider?

Bizarre Silk Structures in the Amazon: Is it the Work of a Spider? | Amazing Science |

After six months of speculation, we finally know what’s building these bizarre silk structures in the Amazon: a spider! But its precise identity is still a mystery that scientists are scrambling to solve.

The bizarre structures first surfaced on the internet late this summer, when graduate student Troy Alexander posted photos to Reddit and Facebook, hoping that somebody could tell him what the structures were. He had discovered them on a small island near the Tambopata Research Center, deep in the Peruvian Amazon.

Made out of silk, the intricate constructions have two parts: a tall, central tower, and a circular fence that’s about 6 millimeters across. Back then, we asked as many entomologists as we could find, but no one had any idea what the structures were, or what made them. Until now.

Last week we followed these spider-hunting scientists, led by entomologist Phil Torres, deep into the Amazon rainforest as they attempted to find the tiny silk towers and figure out where they came from. It has not been an easy case to crack.

Before sunrise on Dec. 10, Torres’ team went to the same small island. As the skies brightened and the mists lifted, they started walking through the forest. A half-hour later, Torres had spotted the first of the tiny towers. Much smaller than he had expected, the structure was on the bark of a cecropia tree, nestled near some branches.

“With a lot of other weird mysteries, once you make an observation of some sort, spend enough time out there, the pieces kind of fit together,” said Torres, a graduate student at Rice University. “I’m surprised by how difficult this one is to solve.”

Via Chuck Sherwood, Senior Associate, TeleDimensions, Inc
Vloasis's curator insight, December 27, 2013 1:19 AM

It takes an unusual critter to fashion those!

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Graphene Effectively Filters Electrons According to the Direction of Their Spin

Graphene Effectively Filters Electrons According to the Direction of Their Spin | Amazing Science |
New research from MIT shows that graphene can effectively filter electrons according to the direction of their spin, something that cannot be done by any conventional electronic system.

Graphene has become an all-purpose wonder material, spurring armies of researchers to explore new possibilities for this two-dimensional lattice of pure carbon. But new research at MIT has found additional potential for the material by uncovering unexpected features that show up under some extreme conditions — features that could render graphene suitable for exotic uses such as quantum computing.

The research is published in Nature in a paper by professors Pablo Jarillo-Herrero and Ray Ashoori, postdocs Andrea Young and Ben Hunt, graduate student Javier Sanchez-Yamaguchi, and three others. Under an extremely powerful magnetic field and at extremely low temperature, the researchers found, graphene can effectively filter electrons according to the direction of their spin, something that cannot be done by any conventional electronic system.

Under typical conditions, sheets of graphene behave as normal conductors: Apply a voltage, and current flows throughout the two-dimensional flake. If you turn on a magnetic field perpendicular to the graphene flake, however, the behavior changes: Current flows only along the edge, while the bulk remains insulating. Moreover, this current flows only in one direction — clockwise or counterclockwise, depending on the orientation of the magnetic field — in a phenomenon known as the quantum Hall effect.

In the new work, the researchers found that if they applied a second powerful magnetic field — this time in the same plane as the graphene flake — the material’s behavior changes yet again: Electrons can move around the conducting edge in either direction, with electrons that have one kind of spin moving clockwise while those with the opposite spin move counterclockwise.

“We created an unusual kind of conductor along the edge,” says Young, a Pappalardo Postdoctoral Fellow in MIT’s physics department and the paper’s lead author, “virtually a one-dimensional wire.” The segregation of electrons according to spin is “a normal feature of topological insulators,” he says, “but graphene is not normally a topological insulator. We’re getting the same effect in a very different material system.”

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Penn Researchers Grow Liquid Crystal 'Flowers' That Can Be Used as Lenses

Penn Researchers Grow Liquid Crystal 'Flowers' That Can Be Used as Lenses | Amazing Science |

A team of material scientists, chemical engineers and physicists from the University of Pennsylvania has made another advance in their effort to use liquid crystals as a medium for assembling structures.

In their earlier studies, the team produced patterns of “defects,” useful disruptions in the repeating patterns found in liquid crystals, in nanoscale grids and rings. The new study adds a more complex pattern out of an even simpler template: a three-dimensional array in the shape of a flower.      

And because the petals of this “flower” are made of transparent liquid crystal and radiate out in a circle from a central point, the ensemble resembles a compound eye and can thus be used as a lens.  

The team consists of Randall Kamien, professor in the School of Arts and Sciences’ Department of Physics and AstronomyKathleen Stebe, the School of Engineering and Applied Science’s deputy dean for research and professor in Chemical and Biomolecular Engineering and Shu Yang, professor in Engineering’s departments of Materials Science and Engineering and Chemical and Biomolecular Engineering. Members of their labs also contributed to the new study, including lead author Daniel Beller, Mohamed Gharbi and Apiradee Honglawan.    

Their work was published in Physical Review X.   

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One small click for a man: NASA releases more than 17,000 photos from the Apollo program

One small click for a man: NASA releases more than 17,000 photos from the Apollo program | Amazing Science |
The archive, released through the Nasa-funded Lunar And Planetary Institute, shows both famous photos of Apollo 11 and everyday work for the astronauts in other missions.

This time 45 years ago, three Americans were orbiting the moon in the Apollo 8 space craft - the furthest from the Earth that any man had ever gone - and were paving the way for humanity's first successful mission to another celestial body. Astronauts Frank Borman, James Lovell and William Anders even read sections of the Book of Genesis as part of a Christmas Eve television broadcast. They were the first to photograph the Earth from far away and the moon up close - also capturing the now-famous 'Earthrise' photo while in lunar orbit.

Now Nasa has released more than 17,000 photos from the 33 Apollo astronauts who made it into space for the lunar missions, including the 12 men who set foot on the moon's surface.

Sharrock's curator insight, December 25, 2013 9:18 PM

pics for students and teachers to use and explore.

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DNA motor 'walks' along nanotube and transports a tiny particle

DNA motor 'walks' along nanotube and transports a tiny particle | Amazing Science |
Researchers have created a new type of molecular motor made of DNA and demonstrated its potential by using it to transport a nanoparticle along the length of a carbon nanotube.

The design was inspired by natural biological motors that have evolved to perform specific tasks critical to the function of cells, said Jong Hyun Choi, a Purdue University assistant professor of mechanical engineering.

Whereas biological motors are made of protein, researchers are trying to create synthetic motors based on DNA, the genetic materials in cells that consist of a sequence of four chemical bases: adenine, guanine, cytosine and thymine. The walking mechanism of the synthetic motors is far slower than the mobility of natural motors. However, the natural motors cannot be controlled, and they don't function outside their natural environment, whereas DNA-based motors are more stable and might be switched on and off, Choi said.

"We are in the very early stages of developing these kinds of synthetic molecular motors," he said. The new findings were detailed in a research paper published in the journal Nature Nanotechnology.

In coming decades, such molecular motors might find uses in drug delivery, manufacturing and chemical processing. The new motor has a core and two arms made of DNA, one above and one below the core. As it moves along a carbon-nanotube track it continuously harvests energy from strands of RNA, molecules vital to a variety of roles in living cells and viruses.

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European space probe on course for a landing on a comet

European space probe on course for a landing on a comet | Amazing Science |
European spacecraft is headed for a landing on a comet next year; 'Nobody has ever done this'

The European Space Agency is planning to land an unmanned spacecraft on a comet next year in an unprecedented and exquisitely tricky mission that has been underway for almost a decade and is about to enter a critical new phase.

The agency announced Tuesday that its Rosetta probe, which has been journeying through space since its launch in 2004, will be awakened from hibernation next month and will aim to drop a lander onto the icy surface of comet 67P/Churyumov-Gerasimenko on Nov. 11, 2014.

The plan is different from NASA's Deep Impact mission, which used a probe to fire a projectile into a comet in 2005 and create a plume of matter for scientists to study. That was just a drive-by compared with the rendezvous the Europeans are planning.

Scientists hope that by flying Rosetta alongside the comet and sending down a barrel-size lander to collect and analyze samples, they will get an even better idea of what comets are made of and what role they played in the formation of our solar system.

"Nobody has ever done this before," said Paolo Ferri, head of mission operations at the European Space Agency. Ferri noted that while NASA managed to land a probe on an asteroid in 2001, comets are much more volatile places because they constantly release dust and gas that can harm a spacecraft. A comet is essentially a dirty snowball; an asteroid is a rock.

To catch 67P as it orbits the sun at up to 100,000 kph (62,000 mph), Rosetta has made several fly-bys of Earth, Mars and the sun, using their gravity to accelerate.

Once the spacecraft picked up sufficient speed and was on course to rendezvous with the comet, ESA put Rosetta into hibernation for more than two years to conserve energy.

This also gave engineers the time to find workarounds for two glitches that threatened the mission: a problem with two of the four reaction wheels used to turn the spacecraft, and a small helium leak that could affect the thrusters vital for its final maneuvers.

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MIT: Colored Plastic Doubles Solar Cell Power

MIT: Colored Plastic Doubles Solar Cell Power | Amazing Science |
Using plastic to absorb light could lower the cost of solar power.

A thin sheet of dyed plastic could cut the cost of solar power, particularly for applications that require solar cells to be highly efficient and flexible. Researchers at the University of Illinois at Urbana-Champaign are using the plastic to gather sunlight and concentrate it onto a solar cell made of gallium arsenide in an experimental setup. Doing so doubled the power output of the cells.

So far, the researchers have shown that the approach works with a single solar cell, but they plan to make larger sheets of plastic dotted with arrays of many tiny solar cells. The approach could either let a smaller solar panel produce more electricity, or make a panel cheaper by reducing the amount of photovoltaic material needed.

“It’s lower cost compared to what you would have to do to get the same efficiency by completely coating the surface with active solar material,” says John Rogers, professor of materials science and engineering and chemistry at the University of Illinois. The work was presented at the Materials Research Society conference in Boston this week.

As light hits the plastic sheet, a specially selected dye absorbs it. The dye is luminescent—meaning that after it absorbs light, it reëmits it. But the light it emits is largely confined inside the plastic sheet. So it bounces along inside the plastic until it reaches a solar cell, much in the same way light is guided along inside a fiber optic cable. The dye absorbs only part of the solar spectrum. So to further boost power output, the researchers added a reflective material that directs some of the light that the dye doesn’t absorb to the solar cell.

The approach could be compatible with another innovation from the same group of researchers—a technique for making flexible and stretchable solar cells that can conform to irregular surfaces (see “Making Stretchable Electronics”).

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Narcolepsy confirmed to be an autoimmune disease

Narcolepsy confirmed to be an autoimmune disease | Amazing Science |
Results also partly explain why the 2009 swine flu virus, and a vaccine against it, led to spikes in the sleep disorder.

As the H1N1 swine flu pandemic swept the world in 2009, China saw a spike in cases of narcolepsy — a mysterious disorder that involves sudden, uncontrollable sleepiness. Meanwhile, in Europe, around 1 in 15,000 children who were given Pandemrix — a now-defunct flu vaccine that contained fragments of the pandemic virus — also developed narcolepsy, a chronic disease.

Immunologist Elizabeth Mellins and narcolepsy researcher Emmanuel Mignot at Stanford University School of Medicine in California and their collaborators have now partly solved the mystery behind these events, while also confirming a longstanding hypothesis that narcolepsy is an autoimmune disease, in which the immune system attacks healthy cells.

Narcolepsy is mostly caused by the gradual loss of neurons that produce hypocretin, a hormone that keeps us awake. Many scientists had suspected that the immune system was responsible, but the Stanford team has found the first direct evidence: a special group of CD4+ T cells (a type of immune cell) that targets hypocretin and is found only in people with narcolepsy.

“Up till now, the idea that narcolepsy was an autoimmune disorder was a very compelling hypothesis, but this is the first direct evidence of autoimmunity,” says Mellins. “I think these cells are a smoking gun.” The study is published today in Science Translational Medicine1.

Thomas Scammell, a neurologist at Harvard Medical School in Boston, Massachusetts, says that the results are welcome after “years of modest disappointment”, marked by many failures to find antibodies made by a person's body against their own hypocretin. “It’s one of the biggest things to happen in the narcolepsy field for some time.”

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Brains on Trial: Determine criminal fate based on high-tech images of the brain

Brains on Trial: Determine criminal fate based on high-tech images of the brain | Amazing Science |
What if we could peer into a brain and see guilt or innocence? Brain scanning technology is trying to break its way into the courtroom, but can we—and should we—determine criminal fate based on high-tech images of the brain?

Join a distinguished group of neuroscientists and legal experts who will debate how and if neuroscience should inform our laws and how we treat criminals. This World Science Festival program is based on a two-part PBS special, “Brains on Trial with Alan Alda,” which aired on September 11 and 18, 2013, supported by the Alfred P. Sloan Foundation.

Laura E. Mirian, PhD's curator insight, December 30, 2013 10:32 AM

Although this may be possible there is always the chance it could be wrong and then we have Vanilla Sky.

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Rabies may not be the invincible killer we thought: Treating rabies with an induced coma

Rabies may not be the invincible killer we thought: Treating rabies with an induced coma | Amazing Science |

The immune system may be able to defeat rabies even after it reaches the brain – could there be an alternative therapy to the Milwaukee protocol?

Rabies is caused by single-stranded negative-sense RNA viruses in the genus of Lyssavirus. Rabies virus (RABV; genotype I) is the most prolific of the 12 viral species classified within the genus, and it is responsible for greater than 55,000 human deaths annually[1]. Typically, RABV is transmitted in the saliva after the bite of an infected mammal. In the Americas, bats and carnivores are the major reservoirs of RABV[2]. Multiple insectivorous bat species play a role in RABV transmission to humans in the United States[3].

In 2011, 8-year-old Precious Reynolds of California became only the sixth person known to survive rabies without receiving a vaccine shortly after infection. At the University of California Davis Children's Hospital doctors treated Reynolds with the Milwaukee protocol – an experimental procedure that plunges the patient into a drug-induced coma, taking the brain "offline" while the immune system scours the virus from infected neurons. But the Milwaukee protocol is not a miracle cure for rabies – far from it. Since Rodney Willoughby of the Children's Hospital of Wisconsin in Milwaukee developed the treatment in 2004, the protocol has been tried at least 35 times around the world in attempts to save people with rabies. Including Reynolds, only five have ostensibly benefited from the treatment.

Why has the Milwaukee protocol worked in only a few cases? The answer may be that the survivors owe their lives not to the experimental treatment, but to a combination of fortunate circumstances and a robust response from their own immune systems. New research suggests that rabies is not quite the unequivocally fatal disease we think it is. The six known survivors may have been infected with weak strains of the rabies virus that their immune systems were able to eventually scrub from their brains – with or without the Milwaukee protocol.

Evidence of Rabies Virus Exposure among Humans in the Peruvian Amazon

  1. Re-evaluating the burden of rabies in Africa and Asia. Bull World Health Organ 83360368 (2005)Medline
  2. Rabies re-examined.Lancet Infect Dis 2327343 (2002)Medline
  3. Emerging epidemiology of bat-associated cryptic cases of rabies in humans in the United States. Clin Infect Dis 35738747 (2002)Medline
  4. Human rabies and rabies in vampire and nonvampire bat species, southeastern Peru, 2007. Emerg Infect Dis 15:13081310 (2009)Medline
  5. Rabies virus in insectivorous bats: implications of the diversity of the nucleoprotein and glycoprotein genes for molecular epidemiology. Virology 405352360 (2010)Medline
  6. Antigenic analysis of rabies-virus isolates from Latin America and the Caribbean. Zoonoses Public Health41153160 (1994)Google Scholar

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Using genetic algorithms to discover new nanostructured materials

Using genetic algorithms to discover new nanostructured materials | Amazing Science |

Researchers at Columbia Engineering, led by Chemical Engineering Professors Venkat Venkatasubramanian and Sanat Kumar, have developed a new approach to designing novel nanostructured materials through an inverse design framework using genetic algorithms. The study, published in the October 28 edition of Proceedings of the National Academy of Sciences (PNAS), is the first to demonstrate the application of this methodology to the design of self-assembled nanostructures, and shows the potential of machine learning and "big data" approaches embodied in the new Institute for Data Sciences and Engineering at Columbia.

"Our framework can help speed up the materials discovery process," says Venkatasubramanian, Samuel Ruben-Peter G. Viele Professor of Engineering, and co-author of the paper. "In a sense, we are leveraging how nature discovers new materials—the Darwinian model of evolution—by suitably marrying it with computational methods. It's Darwin on steroids!"

Using a genetic algorithm they developed, the researchers designed DNA-grafted particles that self-assembled into the crystalline structures they wanted. Theirs was an "inverse" way of doing research. In conventional research, colloidal particles grafted with single-stranded DNA are allowed to self-assemble, and then the resulting crystal structures are examined. "Although this Edisonian approach is useful for a posteriori understanding of the factors that govern assembly," notes Kumar, Chemical Engineering Department Chair and the study's co-author, "it doesn't allow us to a priori design these materials into desired structures. Our study addresses this design issue and presents an evolutionary optimization approach that was not only able to reproduce the original phase diagram detailing regions of known crystals, but also to elucidate previously unobserved structures."

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Insulin pill may soon become a reality

Insulin pill may soon become a reality | Amazing Science |

The idea of oral insulin has been around since the 1930s, but the difficulties of making it seemed too big to overcome. First, insulin is a protein – when it comes in contact with stomach enzymes, it is quickly destroyed. Second, if insulin can pass through the stomach safely, it is too big a molecule (about 30 times the size of aspirin) to be absorbed into the bloodstream, where it needs to be in order to regulate blood-sugar levels.

Sanyog Jain at India’s National Institute of Pharmaceutical Education and Research and his colleagues have been working on delivering insulin in the oral form for many years. Their first fully-successful attempt came in 2012, when they developed a formulation that successfully controlled blood-sugar level in rats. But the materials used were too expensive to consider commercialising the technology.

Now, in a paper published in the journal Biomacromolecules, they have found a cheaper and more reliable way of delivering insulin. They overcome the two main hurdles by, first, packing insulin in tiny sacs made of lipids (fats), and, second, attaching to it folic acid (vitamin B9) to help improve its absorption into the bloodstream.

The lipids they use are cheap and have been successfully employed to deliver other drugs before. These help to protect insulin from being digested by stomach enzymes, which gets it to the small intestine. When the lipid-covered sacs enter the small intestine, special cells on its lining called microfold cells are attracted to the folic acid in them. The folic acid helps activate a transport mechanism that can let big molecules pass through into the blood. The amount of folic acid used in the formulation also seems to be in the safe region.

In rats, Jain’s formulation was as effective as injected insulin, although the relative amounts that entered the blood stream differed. However, it was better in one key aspect. Whereas the effects of an injection are quickly lost (in less than 6 to 8 hours), Jain’s formulation helped control blood-sugar level for more than 18 hours.

The most important part of the research comes after successful testing in animals – the formulation needs to be given to human volunteers. But, Jain said, “at a government institute like ours, we don’t have the sort of money needed for clinical trials.”

He may not have to wait for long, as big pharma companies have been searching for an insulin pill formulation for decades. Two of them, Danish pharma giant Novo Nordisk and Israeli upstart Oramed are in a race to come up with a solution. Google’s venture capital arm, Google Ventures, recently invested $10m in Rani Therapeutics with the hope it will help develop oral insulin. Indian firm Biocon also does oral insulin research, and it recently signed an agreement with pharma giant Bristol-Myers Squibb.

Oramed is ahead, with their oral insulin product soon to enter phase-II clinical trials, which is the most advanced stage any oral insulin formulation has ever reached. Its chief scientist, Miriam Kidron, said of Jain’s research: “Most people have the same basic idea to develop an insulin pill, but its the little differences that will determine ultimate success.”

While Kidron did not reveal Oramed’s formulation, she said, “we attempted liposomal delivery before, just like Jain’s work, but we weren’t successful.” She warned that translating success from rats to humans is very difficult. And she is right – most drugs have a high cull-rate at each stage of their development. Even so, research like Jain’s give hope that an insulin pill may not remain a dream for long.

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Enzyme that produces melatonin originated 500 million years ago, NIH study shows

Enzyme that produces melatonin originated 500 million years ago, NIH study shows | Amazing Science |

An international team of scientists led by National Institutes of Health researchers has traced the likely origin of the enzyme needed to manufacture the hormone melatonin to roughly 500 million years ago. Their work indicates that this crucial enzyme, which plays an essential role in regulating the body’s internal clock, likely began its role in timekeeping when vertebrates (animals with spinal columns) diverged from their nonvertebrate ancestors.

An understanding of the enzyme’s function before and after the divergence may contribute to an understanding of such melatonin-related conditions as seasonal affective disorder, jet lag, and to the understanding of disorders involving vision. The findings provide strong support for the theory that the time-keeping enzyme originated to remove toxic compounds from the eye and then gradually morphed into the master switch for controlling the body’s 24-hour cyclic changes in function. The researchers isolated a second, nonvertebrate form of the enzyme from sharks and other contemporary animals thought to resemble the prototypical early vertebrates that lived 500 million years ago.

Melatonin is a key hormone that regulates the body’s day and night cycle. Dr. Klein explained that it is manufactured in the brain’s pineal gland and is found in small amounts in the retina of the eye. Melatonin is produced from the hormone serotonin, the end result of a multistep sequence of chemical reactions. The next-to-last step in the assembly process consists of attaching a small molecule — the acetyl group — to the nearly finished melatonin molecule. This step is performed by an enzyme called arylalkylamine N-acetyltransferase, or AANAT.

After analyzing DNA from sea creatures thought to resemble early vertebrates, researchers have pieced together a theory of pertaining to the origin of melatonin, which regulates the body’s circadian rythms. The AANAT enzyme, or timezyme, is essential for producing melatonin. One form of AANAT is found only in non-vertebrates, and appears to detoxify potentially hazardous compounds. The researchers contend that a second copy of the gene for producing AANAT appeared about 500 million years ago, when the original gene was duplicated. As vertebrate animals evolved, the second copy of the AANAT gene evolved, eventually specializing in producing melatonin. The theory also holds that the original copy of the AANAT gene later disappeared, and its function was taken over by other genes. In support of their theory, the researchers discovered that two animals thought to be like early vertebrates, the elephant shark and the ratfish, produce both the non-vertebrate and vertebrate forms of AANAT. Two other animals thought to have originated later in vertebrate evolution, the catshark and the sea lamprey, had only the vertebrate AANAT gene.

Before the current study, the researchers lacked proof of their theory, particularly in regard to the question of how the vertebrate form of the enzyme originated because it did not appear to exist in non-vertebrates and had been found only in bony fishes, reptiles, birds, and mammals — all of which lacked the non-vertebrate form.

The first evidence of how the vertebrate form of the enzyme originated came when study co-author Steven L. Coon, also of NICHD, discovered genes for the nonvertebrate and vertebrate forms of AANAT in genomic sequences from the elephant shark, considered to be a living representative of early vertebrates.

This finding indicated that the vertebrate form of AANAT may have resulted after a phenomenon known as gene duplication, Dr. Klein said. Gene duplication, he added, typically results from any of a number of genetic mishaps during cell division. Instead of one copy of a gene resulting from the process, an additional copy results, so that there are two versions of a gene where only one existed previously. The phenomenon is thought to be a major factor influencing evolutionary change.

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Replacement Parts: Engineering pigs, growing organs in the lab or 3D printing them?

Replacement Parts: Engineering pigs, growing organs in the lab or 3D printing them? | Amazing Science |

In the race to solve the organ shortage, xenotransplantation is like the slow and steady tortoise, still taking small steps after a long run-up, while organ engineering is more like a sprinting hare, racing towards a still-distant finish line. Most of those betting on the race are backing the hare. Industry support has dried up for xenotransplantation after years of slow progress, leaving public funders to pick up the expensive tab. Stem cells, meanwhile, continue to draw attention and investment. But both fields have made important advances in recent years, and the likely winner of their race—or whether it will result in a draw—is far from clear.

Pigs could provide all the organs that we need. They are the right size, and we already have the infrastructure to breed them in large numbers. For decades, people have been fitted with heart valves from pigs, and diabetics injected themselves with pig insulin before we learned how to synthesize the human version of the hormone. Whole-organ transplants, however, are another matter.

In 2008, Harald Ott of Massachusetts General Hospital and Doris Taylor of the University of Minnesota dramatically demonstrated the potential of organ engineering by growing a beating heart in the laboratory. As physician-scientists, the two often see patients in dire need of transplantation. They started by using detergents to strip the cells from the hearts of dead rats, leaving behind the extracellular matrix—a white, ghostly, heart-shaped frame of connective proteins like collagen and laminin. Ott and Taylor used this matrix as a scaffold. They seeded it with cells from newborn rats and incubated it in a bioreactor—a vat that provides cells with the right nutrients, and simulates blood flow. After 4 days, the muscles of the newly formed heart began contracting. After 8 days, it started to beat.

This laborious technique, known as whole organ decellularization, is like knocking down a house’s walls to reveal its frame, only to replaster it again. It works because the frame is perfect—it retains the complicated three-dimensional architecture of the organ, including the branching network of blood vessels that provide the cells with nutrients and oxygen. It also preserves the array of complex sugars and growth factors that covers the matrix and provides signposts for growing cells, nudging them into the right shapes and structures. “The matrix really is smart,” says Taylor. “If we put human cells on human heart matrix, they organise in remarkable ways. We can spend the next 20 years trying to understand what’s in a natural matrix and recreate that, or we can take advantage of the fact that nature’s put it together perfectly.”

Ott and Taylor’s groundbreaking feat has since been duplicated for several other organs, including livers, lungs, and kidneys. Rodent versions of all have been grown in labs, and some have been successfully transplanted into animals. Recellularized organs have even found their way into human patients. Between 2008 and 2011, Paolo Macchiarini from the Karolinska Institute in Sweden fitted nine people with new tracheas, built from their own cells grown on decellularized scaffolds. Most of these operations were successful (although three of the scaffolds partially collapsed for unknown reasons after implantation).

Decellularization has one big drawback: it still depends on having an existing organ, either from a donor or an animal. Frustrated by the wait, Macchiarini tried a different approach. In March 2011, he transplanted the first trachea built on an artificial, synthetic polymer scaffold. His patient, an Eritrean man named Andemariam Teklesenbet Beyene, had advanced tracheal cancer and had been given 6 months to live. “He’s now doing well. He’s employed, and his family have come over from Eritrea. He has no need for immunosuppression and doesn’t take any drugs at all,” says Macchiarini. A few months later, he treated a second patient—an American named Christopher Lyles—in the same way, although Lyles later died for reasons unrelated to the transplantation.

Macchiarini now has approval from the US Food and Drug Administration to perform these transplants in the United States on a compassionate basis, for patients who have no other options. “The final organ will never ever be as beautifully perfect as a natural organ,” says Macchiarini, “but the difference is that you don’t need a donation. It can be offered to a patient in need within days or weeks.” By contrast, even if a donor is found, a simple trachea can take a few months to regrow using a decellularized scaffold. Other scientists have enjoyed similar success with other organs. In 1999, Anthony Atala of the Wake Forest Institute for Regenerative Medicine grew bladders using artificial scaffolds, and transplanted them into seven children with spina bifida. By 2006, all the children had gained better urinary control. Atala has just completed Phase II trials of his artificial bladders.

Artificial scaffolds are the future of organ engineering, and the only way in which organs for transplantation could be mass-produced. In future, it will be possible to simulate their architecture with computer models, and fabricate them with modern printing technology (see “3-D Printing,” The Scientist, July 2012.) But even if the architecture is correct, the scaffold would still need to contain the right surface molecules to guide the growth of any added cells.

Xenotransplantation and organ engineering offer different solutions to the organ crisis, but they share similarities. After decades of research, both fields are in the middle of important clinical trials involving simpler tissues and organs, but complex ones like lungs or liver remain a distant goal. “I think we’re still 2 decades away from something that’s clinically realizable,” says Niklason.


Xenotransplants will always have to deal with an immune clash of some degree, so growing an organ that is perfectly matched to a patient would be preferable. The question is whether tissue-engineering technologies will reach that point before genetic engineering enables the first transgenic pig hearts or kidneys to be successfully installed in patients. Sachs says, “I consider xenotransplantation still the nearest-term, best hope for solving the organ shortage, but in the long run, I think tissue engineering will replace it.”

There is also the matter of scale. Platt thinks that organ engineering is too costly to meet the needs of everyone waiting for a transplant. “You’d have to turn over the entire GDP of a country to accomplish that,” he says. On the other hand, “I could get a pig for a couple of hundred dollars.” But Macchiarini argues that organ engineering is in its infancy, and every advance improves efficiency and lowers cost. “What we did in 2008 in 6 months, we can now do in a few weeks,” he says. “We do care about getting this to every patient.”  Mass-producing artificial scaffolds will make organ engineering even more cost-effective. “When you scale them up, the bulk materials and manufacturing tech are extremely cheap,” he says. “I think it’s going to be cheaper than growing lots of pigs.”

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Hawking predicts uploading of the brain into a computer, but not with current technology

Hawking predicts uploading of the brain into a computer, but not with current technology | Amazing Science |

Prof. Hawking, the cosmologist, 71, said the brain operates in a similar way to a computer program, meaning it could in theory be kept running without a body to power it. He made these comments at the 33rd Cambridge Film Festival, featuring a special gala screening of Hawking presented by the documentary’s subject, Professor Stephen Hawking.

Asked about whether a person's consciousness can live on after they die, he said: "I think the brain is like a programme in the mind, which is like a computer, so it's theoretically possible to copy the brain onto a computer and so provide a form of life after death.

"However, this is way beyond out present capabilities. I think the conventional afterlife is a fairy tale for people afraid of the dark." The film tells the story of Prof Hawking's life, from his childhood in Oxford to his current home in Cambridge where he lives with the help of a group of carers.

Carlos Garcia Pando's comment, December 26, 2013 11:50 AM
O.K. Assume we can upload it to a computer. How are we supposed to download it again to a living brain and body? That's the key for me.
Lawrence Lanoff's curator insight, December 29, 2013 1:38 AM

It's facinating to think about - especially when it comes to thinking...

Tomasz Śledzinski's curator insight, January 3, 2014 9:48 AM

Czy Hawkings ma racje co do transportowania mózgu człowieka na dysk?

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The inside of a neutron star is superconducting as well as superfluid

The inside of a neutron star is superconducting as well as superfluid | Amazing Science |

The Crab Nebula and the pulsar at its center are endlessly fascinating. The pulsar is a neutron star, with the same mass as our Sun but only the size of a city. It rotates 30 times per second, flashing like a lighthouse as it does so. It is very nearly, but not quite, an ideal clock, without any outside influence to disturb it. At Jodrell Bank Observatory, astronomers have been watching the pulsar for over 40 years, timing it without missing a beat while it rotated more than 30 billion times. Putting together the results from our radio observations with data from the opposite end of the electromagnetic spectrum has proved remarkably rewarding.

The pulsar has slowed down from 30.2 to 29.7 rotations per second while astronomers have been watching it. This is not unexpected: the energy stored in the rapid rotation powers not only the pulses which we observe but the whole of the Crab Nebula. This little neutron star is acting as a huge electrical generator, spinning at the same speed as a dynamo in a terrestrial power station but with a magnetic field billions of times greater. So far so good, but as is often the case, it is the odd things that seem to be going wrong that we are really interested in.

Astronomers also discovered so-called "glitches", sudden changes in the regular sequence of pulses, showing that the rotation has suddenly sped up, then recovered and started on a new regime of slowing down. We have seen this happen a couple of dozen times. The explanation involves some very strange physics inside the star. Although it is so condensed, the whole of the inside is liquid and only a thin crust is solid. Furthermore, the inside is superfluid, which allows it to rotate independently of the crust. Some times, however, it clutches onto the crust and the whole rotation rate suddenly changes; this is what causes the glitch.

What researchers have found recently is less obvious, having taken the whole of the 40 years to show up. The radio pulse is actually double, like a lighthouse with two beams. These two beams are nearly, but not quite, in opposite directions; how are they formed? Fortunately the Fermi gamma-ray telescope has helped to understand the strange geometry of the atmosphere outside the star, where the beams are formed. The whole of this atmosphere is rotating with the star itself, swept round by the powerful magnetic field. It is called a magnetosphere, and it is forced to move so fast that it reaches relativistic speeds; the radiation appears to originate at a location so far outside the surface that it is moving with half the velocity of light. Now comes some more new physics.

The inside of a neutron star is superconducting as well as superfluid. This means that the strength and shape of the huge dipole magnetic field is fixed, or can change only very slowly. So the pattern of the magnetic field in the magnetosphere, where the radiated beams are formed, is fixed. But the star is less than 1000 years old (it was formed in a supernova explosion in the year 1054), so we have been observing it for an appreciable fraction of its lifetime. And we have indeed found a change in the pattern of the double pulse. The two parts are moving apart, at the rate of 3o in the whole lifetime of the star. What this means is that the dipole is not tidily arranged at a right angle to the rotation, as it would be in a power station dynamo, but it is tilted at around 45o and slowly moving to wards the expected orthogonal arrangement. Now the theorists have to take over and explain how that can happen!

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Chasing the Higgs: How 2 Teams of Rivals Searched for Physics’ Most Elusive Particle

Chasing the Higgs: How 2 Teams of Rivals Searched for Physics’ Most Elusive Particle | Amazing Science |
At the Large Hadron Collider near Geneva, two armies of physicists struggled to close in on the Higgs boson, the Great White Whale of modern science.

Last year, the discovery of the particle credited with giving others mass was cheerfully announced to a packed and jubilant auditorium at CERN near Geneva, Switzerland. The moment marked the end of a 50-year hunt. But although the boson has been found, there is still plenty we do not know about the celebrated particle.

When the particle's discovery was announced, researchers working with the Large Hadron Collider (LHC) at CERN resisted calling their quarry the Higgs boson outright, preferring the vaguer "Higgs-like boson", or "particle resembling the Higgs". They knew the particle they had glimpsed was a brand new boson, one of two types of elementary particle. But it was not clear if its properties corresponded exactly to those laid out for the Higgs in the standard model of particle physics, which describes all known particles and the forces acting on them.

In fact, many physicists were hoping the boson would prove to be something more exotic, because this would suggest ways to extend the standard model, which currently cannot explain dark matter or gravity, for example.

A year on, key properties known as spin and parity, as well as the exact particles the boson decays into, are gradually being pinned down, and the boson seems to be behaving as expected, leading to the award of official Higgs status in March. "We have made enough property measurements to start to convince ourselves that what we are looking at is a Higgs boson," says Oliver Buchmueller of Imperial College London, a member of the LHC's CMS collaboration, one of the two teams that announced evidence for the Higgs.

But even though it fulfils the minimum requirements of a Higgs boson, that doesn't mean it is vanilla, says Buchmueller. "The precision with which we are measuring these properties today is not sufficient to say whether this is the minimal realisation of the Higgs mechanism – or something more." One mystery that remains is why the Higgs boson decays into more photons than expected. This excess was initially reported last July. In the latest analyses, ATLAS still sees the Higgs decaying into too many photons, while in data collected by CMS there is no excess.

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Worlds Around Other Worlds: First Possible Exomoon Spotted

Worlds Around Other Worlds: First Possible Exomoon Spotted | Amazing Science |

Worlds around other worlds may be habitable. Even as the number of planets known beyond the Solar System climbs above 1,000, the discovery of an accompanying exomoon has remained elusive — until, perhaps, now.

Many exoplanets probably have moons orbiting them. Some of those moons might even be large enough, and have an atmosphere, to host extraterrestrial life.

On a June night two years ago, a telescope in New Zealand captured a momentary brightening of a star in the constellation Sagittarius. It was an occurence of a rare phenomenon known as microlensing, in which a star or planet or other celestial object passes directly between Earth and a more distant star, gravitationally magnifying the light of the faraway star.

After sifting through detailed observations of this event, astronomers proposed that the intervening object could be either a smallish star with a Neptune-sized planet orbiting it, or a largish planet with a moon orbiting it. If the latter possibility is confirmed, it would be the first ever detection of an exomoon. The problem is that there is no way to repeat the observation and know for sure.

The possible discovery was reported in a paper posted on 13 December on the arXiv preprint server1. It comes from a group of scientists studying microlensing that is led by David Bennett, an astrophysicist at the University of Notre Dame in Indiana.

  1. Bennett, D. P. et alPreprint available at (2013).

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NASA: 1 in 63,000 chance that asteroid 2013 TV135 will hit Earth in 2032

NASA: 1 in 63,000 chance that asteroid 2013 TV135 will hit Earth in 2032 | Amazing Science |
The probability asteroid 2013 TV135 could impact Earth is only one in 63,000. Additional observations are likely to result in a dramatic reduction, or complete elimination, of any risk of Earth impact.

Newly discovered asteroid 2013 TV135 made a close approach to Earth on Sept. 16, 2013, when it came within about 4.2 million miles (6.7 million kilometers). The asteroid is initially estimated to be about 1,300 feet (400 meters) in size and its orbit carries it as far out as about three quarters of the distance to Jupiter's orbit and as close to the sun as Earth's orbit. It was discovered by astronomers working at the Crimean Astrophysical Observatory in Ukraine. As of Oct. 14, asteroid 2013 TV135 is one of 10,332 near-Earth objects that have been discovered. 

With only a week of observations for an orbital period that spans almost four years, its future orbital path is still quite uncertain, but this asteroid could be back in Earth's neighborhood in 2032. However, NASA's Near-Earth Object Program Office states the probability this asteroid could then impact Earth is only one in 63,000. The object should be easily observable in the coming months and once additional observations are provided to the Minor Planet Center in Cambridge, Mass., the initial orbit calculations will be improved and the most likely result will be a dramatic reduction, or complete elimination, of any risk of Earth impact. 

"To put it another way, that puts the current probability of no impact in 2032 at about 99.998 percent," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. "This is a relatively new discovery. With more observations, I fully expect we will be able to significantly reduce, or rule out entirely, any impact probability for the foreseeable future." 

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them and identifies their orbits to determine if any could be potentially hazardous to our planet. 

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. More information about asteroids and near-Earth objects is at:

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New artificial cartilage mimics strength and suppleness of native cartilage

New artificial cartilage mimics strength and suppleness of native cartilage | Amazing Science |

Tiny interwoven fibers make up the three-dimensional fabric scaffold into which a strong, pliable hydrogel is integrated and injected with stem cells, forming.

Articular cartilage is the tissue on the ends of bones where they meet at joints in the body — including in the knees, shoulders and hips. It can erode over time or be damaged by injury or overuse, causing pain and lack of mobility. While replacing the tissue could bring relief to millions, replicating the properties of native cartilage — which is strong and load-bearing, yet smooth and cushiony — has proven a challenge.  

In 2007 Guilak and his team developed a three-dimensional fabric scaffold into which stem cells could be injected and successfully “grown” into articular cartilage tissue. Constructed of minuscule woven fibers, each of the scaffold’s seven layers is about as thick as a human hair. The finished product is about 1 millimeter thick.

Since then, the challenge has been to develop the right medium to fill the empty spaces of the scaffold — one that can sustain compressive loads, provide a lubricating surface and potentially support the growth of stem cells on the scaffold. Materials supple enough to simulate native cartilage have been too squishy and fragile to grow in a joint and withstand loading. “Think Jell-O,” says Guilak. Stronger substances, on the other hand, haven’t been smooth and flexible enough.

That’s where the partnership with Zhao comes in. Zhao proposed a theory for the design of durable hydrogels(water-based polymer gels) and in 2012 collaborated with a team from Harvard University to develop an exceptionally strong yet pliable interpenetrating-network hydrogel.

“It’s extremely tough, flexible and formable, yet highly lubricating,” Zhao says. “It has all the mechanical properties of native cartilage and can withstand wear and tear without fracturing.”

He and Guilak began working together to integrate the hydrogel into the fabric of the 3-D woven scaffolds in a process Zhao compares to pouring concrete over a steel framework.


Rosamaria's curator insight, December 23, 2013 8:22 PM

La informática integrada a la Medicina provocará un salto en la especie humana. Y todo apunta a que la ley de Moore aplicará también a la biotecnología. La Era de la información nos depara sorpresas Insospechadas.