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How Many Earths? Interactive Kepler Data

How Many Earths? Interactive Kepler Data | Amazing Science | Scoop.it

This interactive graphic is based on the data for candidate planets identified by NASA's Kepler Space Telescope. Kepler found these planets by recording the slight dimming of the light from a star caused by a planet passing in front of it.

 

About 10 per cent of the candidate planets will probably turn out to be no such thing – it's possible to mistake the second star in a binary star system for a giant planet, for example. On the other hand, Kepler probably missed around 10 per cent of the planets that passed in front of target stars because the dimming of the star's light was too slight to detect against the natural variability in the stars' light output. These two numbers roughly cancel each another out, so they are not included in our calculations.

 

The first step in answering "How many Earths?" was to ignore planets twice the Earth's diameter or larger: these are likely to be gas giants like Jupiter, not rocky worlds like ours. However, such planets may possess rocky moons, which could well host life.

 

Not all of the remaining planets will be hospitable to life. For example, carbon-rich planets could have a graphite crust with layers of diamond below and rivers of oil and tar.

 

Kepler could not determine a planet's composition, but to calculate how many planets might be friendly to life, we estimated the number in stars' habitable zones – orbits where a planet will be neither too hot nor too cold for water to exist in liquid form.

 

Defining a star's habitable zone is a complex process, but as a reasonable proxy we used Kepler's estimates of planets' equilibrium temperature. This is the temperature that would be measured at a planet's surface if it were a black body heated by its parent star without any atmospheric greenhouse effect.

 

The next step – the most uncertain part of our quest – was extrapolating to the total number of roughly Earth-sized planets likely to be orbiting Kepler's 150,000 target stars. Simple geometry tells us that Kepler will have missed most of these planets: the tilts of their orbits mean they never passed between their parent stars and the telescope. And the farther out a planet orbits, the harder it was for Kepler to detect.

 

Taking everything into account, the best estimate for the average number of roughly Earth-sized planets in each star's habitable zone is 0.15, according to simulations based on Kepler data thatCourtney Dressing and David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, performed. Applying this average to Kepler's 150,000 target stars gave our estimate of 22,500 potentially habitable, roughly Earth-sized planets.

 

There is an important caveat, though. Dressing and Charbonneau's calculations are for class M stars, which have a reddish hue and account for about three-quarters of the stars in our galaxy. But about 80 per cent of Kepler's target stars are class G stars, like our sun, which are yellowish. Nobody knows for sure whether these different classes of stars have similar populations of planets.

 

The final step in our quest was to extrapolate to the entire galaxy. Estimates of the number of stars in the Milky Way vary from 100 billion to 200 billion. Applying the same estimate of 0.15 potentially Earth-like planets per star gave our figure of between 15 and 30 billion.

 

If we had displayed all these potential planets in the final view, the sky would have become a mass of green. To give a meaningful view for someone here on Earth, we selected stars from the European Space Agency's Tycho-2 catalogue with an apparent magnitude of 10.5 or brighter – these stars would be visible on a dark night with a good pair of binoculars. We have displayed a random sample of 15 per cent of these stars, corresponding to Dressing and Charbonneau's estimate of stars with potentially habitable, roughly Earth-sized planets.

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The Planetary Archives / San Francisco, California's curator insight, September 30, 2013 3:56 PM

2500 years ago, the Buddha is said to have remarked that there are "many, many" planets with beings just like us..... 

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New gut bacterium discovered mainly responsible for termites' capability to digest wood

New gut bacterium discovered mainly responsible for termites' capability to digest wood | Amazing Science | Scoop.it

When termites munch on wood, the small bits are delivered to feed a community of unique microbes living in their guts, and in a complex process involving multiple steps, these microbes turn the hard, fibrous material into a nutritious meal for the termite host. One key step uses hydrogen to convert carbon dioxide into organic carbon -- a process called acetogenesis -- but little is known about which gut bacteria play specific roles in the process. Utilizing a variety of experimental techniques, researchers from the California Institute of Technology (Caltech) have now discovered a previously unidentified bacterium -- living on the surface of a larger microorganism in the termite gut -- that may be responsible for most gut acetogenesis.

 

"In the termite gut, you have several hundred different species of microbes that live within a millimeter of one another. We know certain microbes are present in the gut, and we know microbes are responsible for certain functions, but until now, we didn't have a good way of knowing which microbes are doing what," says Jared Leadbetter, professor of environmental microbiology at Caltech, in whose laboratory much of the research was performed.

 

Acetogenesis is the production of acetate (a source of nutrition for termites) from the carbon dioxide and hydrogen generated by gut protozoa as they break down decaying wood. In their study of "who is doing what and where," Leadbetter and his colleagues searched the entire pool of termite gut microbes to identify specific genes from organisms responsible for acetogenesis.

 

The researchers began by sifting through the microbes' RNA -- genetic information that can provide a snapshot of the genes active at a certain point in time. Using RNA from the total pool of termite gut microbes, they searched for actively transcribed formate dehydrogenase (FDH) genes, known to encode a protein necessary for acetogenesis. Next, using a method called multiplex microfluidic digital polymerase chain reaction (digital PCR), the researchers sequestered the previously unstudied individual microbes into tiny compartments to identify the actual microbial species carrying each of the FDH genes. Some of the FDH genes were found in types of bacteria known as spirochetes -- a previously predicted source of acetogenesis. Yet it appeared that these spirochetes alone could not account for all of the acetate produced in the termite gut.

 

Initially, the Caltech researchers were unable to identify the microorganism expressing the single most active FDH gene in the gut. However, the first authors on the study, Adam Rosenthal, a postdoctoral scholar in biology at Caltech, and Xinning Zhang (PhD '10, Environmental Science and Engineering), noticed that this gene was more abundant in the portion of the gut extract containing wood chunks and larger microbes, like protozoans. After analyzing the chunkier gut extract, they discovered that the single most active FDH gene was encoded by a previously unstudied species from a group of microbes known as the deltaproteobacteria. This was the first evidence that a substantial amount of acetate in the gut may be produced by a non-spirochete.

 

Because the genes from this deltaproteobacterium were found in the chunky particulate matter of the termite gut, the researchers thought that perhaps the newly identified microbe attaches to the surface of one of the chunks. To test this hypothesis, the researchers used a color-coded visualization method called hybridization chain reaction-fluorescent in situ hybridization, or HCR-FISH.

 

The technique -- developed in the laboratory of Niles Pierce, professor of applied and computational mathematics and bioengineering at Caltech, and a coauthor on the PNAS study -- allowed the researchers to simultaneously "paint" cells expressing both the active FDH gene and a gene identifying the deltoproteobacterium with different fluorescent colors simultaneously. "The microfluidics experiment suggested that the two colors should be expressed in the same location and in the same tiny cell," Leadbetter says. And, indeed, they were. "Through this approach, we were able to actually see where the new deltaproteobacterium resided. As it turns out, the cells live on the surface of a very particular hydrogen-producing protozoan."

 

This association between the two organisms makes sense based on what is known about the complex food web of the termite gut, Leadbetter says. "Here you have a large eukaryotic single cell -- a protozoan -- which is making hydrogen as it degrades wood, and you have these much smaller hydrogen-consuming deltaproteobacteria attached to its surface," he says. "So, this new acetogenic bacterium is snuggled up to its source of hydrogen just as close as it can get."

 

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Biologists Confirm Role of Sperm Competition in Formation of New Species

Biologists Confirm Role of Sperm Competition in Formation of New Species | Amazing Science | Scoop.it

Biologists in Syracuse University’s College of Arts and Sciences have confirmed that reproductive isolation, a critical step in the formation of new species, can arise from diversifying sperm competition. Their findings, which have major implications for the study of biodiversity, are the subject of a groundbreaking article in the Oct. 7th issue of Current Biology (Elsevier, 2013).

 

Female promiscuity—something that occurs in a majority of species, including humans—results in the ejaculates from two or more males overlapping within her reproductive tract. When this happens, sperm compete for fertilization of the female’s eggs. In addition, the female has the opportunity to bias fertilization of her eggs in favor of one male’s sperm over others.

 

These processes, collectively known as postcopulatory sexual selection, drive a myriad of rapid, coordinated evolutionary changes in ejaculate and female reproductive tract traits. These changes have been predicted to be an important part of speciation, the process by which new biological species arise.

 

Until now, traits and processes that influence fertilization success have been poorly understood, due to the challenges of observing what sperm do within the female’s body and of discriminating sperm among different males. Almost nothing is known about what determines the sperm’s fate in hybrid matings where there may be an evolutionary mismatch between ejaculate and female reproductive tract traits.

 

Professor John Belote has overcome these challenges by genetically engineering closely related species of fruit flies with different colors of glow-in-the-dark-sperm. Working closely with Scott Pitnick, Mollie Manier, and other colleagues in SU’s Pitnick Lab, he is able to observe ejaculate-female interactions and sperm competition in hybrid matings.

 

“How new species arise is one of the most important questions facing biologists, and we still have a lot to learn,” says Pitnick, a professor in SU's Department of Biology, adding that the mechanisms maintaining the genetic boundary between species is difficult to pin down. “This paper [in Current Biology] is perhaps the most important one of my career. It has been six years in the making.”

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Number of Confirmed Alien Planets Nears 1,000 (Unconfirmed 3,500)

Number of Confirmed Alien Planets Nears 1,000 (Unconfirmed 3,500) | Amazing Science | Scoop.it

Just two decades after discovering the first world beyond our solar system, astronomers are closing in on alien planet No. 1,000.

 

Four of the five main databases that catalog the discoveries of exoplanets  now list more than 900 confirmed alien worlds, and two of them peg the tally at 986 as of today (Sept. 26). So the 1,000th exoplanet may be announced in a matter of days or weeks, depending on which list you prefer.

 

That's a lot of progress since 1992, when researchers detected two planets orbiting a rotating neutron star, or pulsar, about 1,000 light-years from Earth. Confirmation of the first alien world circling a "normal" star like our sun did not come until 1995.

 

And the discoveries will keep pouring in, as astronomers continue to hone their techniques and sift through the data returned by instruments on the ground and in space.

 

The biggest numbers in the near future should come from NASA'sKepler space telescope, which racked up many finds before being hobbled in May of this year when the second of its four orientation-maintaining reaction wheels failed.

 

Kepler has identified 3,588 planet candidates to date. Just 151 of these worlds have been confirmed so far, but mission scientists have said they expect at least 90 percent will end up being the real deal.

 

But even these numbers, as impressive as they are, represent just the tip of our Milky Way galaxy's immense planetary iceberg. Kepler studied a tiny patch of sky, after all, and it only spotted planets that happened to cross their stars' faces from the instrument's perspective.

 

Many more planets are thus out there, zipping undetected around their parent stars. Indeed, a team of researchers estimated last year that every Milky Way star hosts, on average, 1.6 worlds — meaning that our galaxy perhaps harbors 160 billion planets.

 

And those are just the worlds with obvious parent stars. In 2011, a different research team calculated that "rogue planets" (which cruise through space unbound to a star) may outnumber "normal" exoplanets by 50 percent or so.

 

Nailing down the numbers is of obvious interest, but what astronomers really want is a better understanding of the nature and diversity of alien worlds.

And it's becoming more and more apparent that this diversity is stunning. Scientists have found exoplanets as light and airy as Styrofoam, for example, and others as dense as iron. They've also discovered a number of worlds that appear to orbit in their stars' habitable zone — that just-right range of distances that could support the existence of liquid water and thus, perhaps, life as we know it.

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Human robot getting closer: iCub robot must learn from its experiences

Human robot getting closer: iCub robot must learn from its experiences | Amazing Science | Scoop.it
A robot that feels, sees and, in particular, thinks and learns like us. It still seems like science fiction, but new research hints that it could happen. Scientists are working to implement the cognitive process of the human brain in robots.

 

The research should lead to the arrival of the latest version of the iCub robot in Twente. This human robot (humanoid)blurs the boundaries between robot and human.


Decades of scientific research into cognitive psychology and the brain have given us knowledge about language, memory, motor skills and perception. We can now use that knowledge in robots, but Frank van der Velde's research goes even further. "The application of cognition in technical systems should also mean that the robot learns from its experiences and the actions it performs. A simple example: a robot that spills too much when pouring a cup of coffee can then learn how it should be done."


The arrival of the iCub robot at the University of Twente should signify the next step in this research. Van der Velde submitted an application together with other UT researchers Stefano Stramigioli, Vanessa Evers, Dirk Heylen and Richard van Wezel, all active in the robotics and cognitive research. At the moment, twenty European laboratories have an iCub, which was developed in Italy (thanks to a European FP7 grant for the IIT). The Netherlands is still missing from the list. Moreover, a newer version is currently being developed, with for example haptic sensors. In February it will be announced whether the robotics club will actually bring the latest iCub to the UT. The robot costs a quarter of a million Euros and NWO (Netherlands Organisation for Scientific Research) will reimburse 75% of the costs. Then the TNO (Netherlands Organisation for Applied Scientific Research) and the universities of Groningen, Nijmegen, Delft and Eindhoven can also make use of it. Within the UT, the iCub can be deployed in different laboratories thanks to a special transport system.


The possibilities are endless, according to Van der Velde. "The new iCub has a skin and fingers that have a much better sense of touch and can feel strength. That makes interaction with humans much more natural. We want to ensure that this robot continues to learn and understands how people function. This research ensures, for example, that robots actually gather knowledge by focusing on certain objects or persons. In areas of application like healthcare and nursing, such robots can play an important role. A good example would be that in ten years' time you see a blind person walking with a robot guide dog."


Video: http://www.youtube.com/watch?v=ZcTwO2dpX8A

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Alien frontier: See the haunting, beautiful weirdness of Mars in Hi-Res Pictures

Alien frontier: See the haunting, beautiful weirdness of Mars in Hi-Res Pictures | Amazing Science | Scoop.it

Mounted to the Mars Reconnaissance Orbiter as it floats high above the red planet is the HiRISE telescope, an imaging device capable of taking incredibly high-resolution photos of the martian landscape. It's sent back nearly 30,000 photos during its time above the planet, which have been used by NASA to find clear landing spots for rovers, and by researchers to learn more about the features of Mars' surface.

 

The stunning views captured by HiRISE have inspired a book from the publisher Aperture, called This is Mars, which includes 150 of its finest looks at the planet. The entire collection is in black and white, however, as that's how HiRISE's images naturally turn out.

 

But by combining different color filters on the telescope, NASA is able to produce colored versions of most images too. They're known as "false color" images, since they won't perfectly match up with what the human eye would see. False color images are still useful, however, in helping researchers distinguish between different elements of Mars' landscape. They're also downright gorgeous to look through. Below, we've collected our own series of some of the most incredible sights taken by HiRISE throughout 2013.

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Adrian Rojas's comment, October 7, 2013 11:36 PM
Well I thought Aliens didn't exist? And if they didn't why are they saying they have found alien made things on Mars. I believe in aliens because there is proof but then you hear someone say no and they try to find some scientific way of proving that aliens don't exist. And some of the pictures here don't really show or prove that aliens made them because I could have just been eroded or gravity formed it like that. There is many explanation that these photographs are not alien made because it could of just been naturally made like that.

How do we have photos of Mars if we have never been there? And there was an article that said they have found water on Mars so it's not impossible if there was life on the planet. But you can't just jump on the conclusion that there are aliens on Mars.
Dr. Stefan Gruenwald's comment, October 8, 2013 2:32 AM
Alien in the title is used as an adjective and means "strange, foreign". It has NOTHING to do with actual aliens. Where do you get this idea from?
alenav09's curator insight, October 11, 2013 7:42 PM

Wow aliens that's crazy and to think some people actually think that there are no aliens we'll just wow. If you really think about it then you can see that we can't be the only possible life forms out there!!!!!

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Scientists create never-before-seen form of matter

Scientists create never-before-seen form of matter | Amazing Science | Scoop.it
Harvard and MIT scientists are challenging the conventional wisdom about light, and they didn't need to go to a galaxy far, far away to do it.

 

Working with colleagues at the Harvard-MIT Center for Ultracold Atoms, a group led by Harvard Professor of Physics Mikhail Lukin and MIT Professor of Physics Vladan Vuletic have managed to coax photons into binding together to form molecules – a state of matter that, until recently, had been purely theoretical. The work is described in a September 25, 2013, paper in Nature.

 

The discovery, Lukin said, runs contrary to decades of accepted wisdom about the nature of light. Photons have long been described as massless particles which don't interact with each other – shine two laser beams at each other, he said, and they simply pass through one another.

 

"Photonic molecules," however, behave less like traditional lasers and more like something you might find in science fiction – the light saber.

 

"Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other," Lukin said. "What we have done is create a special type of medium in which photons interact with each other so strongly that they begin to act as though they have mass, and they bind together to form molecules. This type of photonic bound state has been discussed theoretically for quite a while, but until now it hadn't been observed.

 

"It's not an in-apt analogy to compare this to light sabers," Lukin added. "When these photons interact with each other, they're pushing against and deflect each other. The physics of what's happening in these molecules is similar to what we see in the movies."

 

To get the normally-massless photons to bind to each other, Lukin and colleagues, including Harvard post-doctoral fellow Ofer Fisterberg, former Harvard doctoral student Alexey Gorshkov and MIT graduate students Thibault Peyronel and Qiu Liang couldn't rely on something like the Force – they instead turned to a set of more extreme conditions.

 

Researchers began by pumped rubidium atoms into a vacuum chamber, then used lasers to cool the cloud of atoms to just a few degrees above absolute zero. Using extremely weak laser pulses, they then fired single photons into the cloud of atoms.

 

As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically. As the photon moves through the cloud, that energy is handed off from atom to atom, and eventually exits the cloud with the photon.

 

"When the photon exits the medium, its identity is preserved," Lukin said. "It's the same effect we see with refraction of light in a water glass. The light enters the water, it hands off part of its energy to the medium, and inside it exists as light and matter coupled together, but when it exits, it's still light. The process that takes place is the same it's just a bit more extreme – the light is slowed considerably, and a lot more energy is given away than during refraction."

 

When Lukin and colleagues fired two photons into the cloud, they were surprised to see them exit together, as a single molecule.

 

The reason they form the never-before-seen molecules?

 

An effect called a Rydberg blockade, Lukin said, which states that when an atom is excited, nearby atoms cannot be excited to the same degree. In practice, the effect means that as two photons enter the atomic cloud, the first excites an atom, but must move forward before the second photon can excite nearby atoms.

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Martian Top Soil Contains Two Percent Water

Martian Top Soil Contains Two Percent Water | Amazing Science | Scoop.it

NASA's Mars Science Laboratory rover Curiosity has found that the Mars topsoil is laced with surprisingly high quantities of water.

 

By now, we probably all know that there was once significant quantities of water on the Martian surface and, although the red planet is bone dry by terrestrial standards, water persists as ice just below the surface to this day.

Now, according to a series of new papers published in the journal Science, NASA’s Mars Science Laboratory rover Curiosity has found that the Mars topsoil is laced with surprisingly high quantities of the wet stuff.

 

“One of the most exciting results from this very first solid sample ingested by Curiosity is the high percentage of water in the soil,” said Laurie Leshin, Dean of Science at the Rensselaer Polytechnic Institute, N.Y., and lead author of one of the studies focusing on SAM analysis of Mars ‘fines.’ “About 2 percent of the soil on the surface of Mars is made up of water, which is a great resource, and interesting scientifically.”

 

Once scooped out of the ground by the rover’s robotic arm-mounted scoop (called the Collection and Handling for In-Situ Martian Rock Analysis, or, simply, CHIMRA), a small amount of the powder was sieved and dropped into SAM where it was heated to 835 degrees Celsius (1,535 degrees Fahrenheit). SAM then used its gas chromotograph, mass spectrometer and tunable laser spectrometer to identify the chemicals contained within the sample and the ratios of the different isotopes of elements contained within.

 

When heated, the instrument detected the abundance of water plus significant quantities of carbon dioxide, oxygen and sulfur compounds, according to the researchers. Carbonate materials — compounds that form in the presence of water — were also identified. The experiment confirmed the presence of oxygen- and chlorine-containing compounds — likely chlorates or perchlorates. Originally discovered by NASA’s 2008 Phoenix Mars Lander (and likely detected by NASA’s Viking landers in 1976), perchlorates were found in the soil of high-latitude arctic regions. This indicates that perchlorates occur globally over Mars.

 

 Though highly toxic to human biology, some microbes are known to use the oxidizing chemical for energy. This finding intensified the debate over whether hypothetical microbes on Mars could metabolize perchlorates in a similar way.

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New Treatment for Gonorrhea Prevents Reinfection

New Treatment for Gonorrhea Prevents Reinfection | Amazing Science | Scoop.it

A first step has been taken toward a treatment for gonorrhea, a sexually transmitted disease (STD) notorious for its high reinfection rates. This news comes within days of a troubling update from the U.S. Centers for Disease Control that placed the STD on a list of “urgent threats” in the fight against drug-resistant bacteria. According to the CDC, Neisseria gonorrhoeae, the bacteria that causes the malady in humans—which can initially result in painful inflammation and discharge, and can cause infertility and even death if not treated—requires urgent and aggressive action from the medical research community. Researchers from the University at Buffalo, S.U.N.Y., think the answer may lie in marshaling the immune system against gonorrhea.

 

The study, published in The Journal of Infections Diseases, found gonococcal infections in mice could be cured by introducing into the genital tract a cytokine, or immunoregulatory protein, known asinterleukin-12 (IL-12), which is also being investigated as a cancer-fighting agent. Michael Russell, a microbiologist and immunologist at S.U.N.Y. Buffalo and one of the study’s authors, says that his 20-year investigation into gonorrhea and its resilience led him to suspect that it was actively altering immune systems, preventing human hosts from developing long-term resistance to it.

 

The exact mechanism of the alteration remains unclear, but Russell thinks it has to do with the two distinct “arms” of vertebrate immune systems: innate and adaptive. Russell observed high levels of a cytokine called interleukin-10 (IL-10) in gonococcal infections, and observed that it induces an innate immune response. IL-10 seems to suppress adaptive responses—like the formation of antibodies that can be used again to fight later infections—in favor of more general, short-term innate responses. Meanwhile, the innate responses, such as inflammation, are easy for N. gonorrhoeaeto beat. If IL-12 could counteract the effects of IL-10, Russell hypothesized, it could help the body fight gonorrhea more effectively, and could be used in a treatment for the STD. When his colleague Nejat Egilmez developed a new delivery mechanism for the otherwise toxic IL-12, in which microspheres of slow-releasing nanoparticles of the cytokine could be targeted directly onto immunosuppressant tumors, Russell’s team decided to try injecting them into the vaginal tracts of infected mice.

 

“And it worked,” he says, “very nicely.” Not only did mice treated with IL-12 respond more quickly to antibiotics, they were also significantly less likely to be reinfected than controls when exposed to the same strain a month later. “We found that the IL-12 treatment allows the development of an adaptive immune response not usually seen,” Russell says. It seems that by counteracting the IL-10 present at gonococcal infections, the treatment prevents immune systems from being tricked out of developing adaptive responses to the disease. The effect, he says, lasts for several months.

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Unsolved phenomenum: Why a Voltage-Generated Water Bridge Doesn't Collapse

Unsolved phenomenum: Why a Voltage-Generated Water Bridge Doesn't Collapse | Amazing Science | Scoop.it

If you apply an electric voltage across two water-filled beakers and separate them, something strange happens: The water stretches from beaker to beaker, creating a bridge that defies gravity. Water bridges were discovered 120 years ago, but no one has ever been sure why they do not collapse. One theory is that the voltage makes the water molecules line up, creating a “dielectric” tension that stops the bridge from falling. Another argues that surface tension—the tendency of a water’s surface to shrink inwards—keeps the bridge aloft.


Now, researchers believe that water bridges rely on both strategies. Reza Namin at the Sharif University of Technology in Tehran and colleagues measured various parameters across the length of a water bridge, including voltage, current, and bridge diameter. Then they plugged the data into a computer simulation to calculate the forces involved. The results, to be published next month in Physical Review E, reveal that dielectric tension and surface tension each carry about half a water bridge’s weight. The results, the researchers believe, could help engineers develop electrowetting, a method of using electricity to adjust the adhesion of fluids to a screen that is expected to be used in the next generation of e-book readers.

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NASA's Hubble and Chandra Find The Densest Nearby Galaxy

NASA's Hubble and Chandra Find The Densest Nearby Galaxy | Amazing Science | Scoop.it

Observations from the W. M. Keck Observatory on the summit of Mauna Kea, Hawaii, characterized it as the most luminous known galaxy of its type and one of the most massive, weighing 200 million times more than our Sun.

 

What makes M60-UCD1 so remarkable is that about half of this mass is found within a radius of only about 80 light years. This would make the density of stars about 15,000 times greater than found in Earth’s neighborhood in the Milky Way, meaning that the stars are about 25 times closer.

 

"Traveling from one star to another would be a lot easier in M60-UCD1 than it is in our galaxy," said Jay Strader of Michigan State University in Lansing, first author of a new paper describing these results. "But it would still take hundreds of years using present technology."

 

The 6.5-meter Multiple Mirror Telescope in Arizona was used to study the amount of elements heavier than hydrogen and helium in stars in M60-UCD1. The values were found to be similar to our Sun.

 

"The abundance of heavy elements in this galaxy makes it a fertile environment for planets and, potentially, life to form," said co-author Anil Seth of the University of Utah.

 

Another intriguing aspect of M60-UCD1 is that the Chandra data reveal the presence of a bright X-ray source in its center. One explanation for this source is a giant black hole weighing in at some 10 million times the mass of the Sun.

 

Astronomers are trying to determine if M60-UCD1 and other ultra-compact dwarf galaxies are either born as jam-packed star clusters or if they are galaxies that get smaller because they have stars ripped away from them.

 

Large black holes are not found in star clusters, so if the X-ray source is in fact due to a massive black hole, it was likely produced by collisions between the galaxy and one or more nearby galaxies. The mass of the galaxy and the Sun-like abundances of elements also favor the idea that the galaxy is the remnant of a much larger galaxy.

 

"We think nearly all of the stars have been pulled away from the exterior of what once was a much bigger galaxy," said co-author Duncan Forbes of Swinburne University in Australia. "This leaves behind just the very dense nucleus of the former galaxy, and an overly massive black hole."

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Nuclear fusion, anyone? Not quite yet, but we've come very close

Nuclear fusion, anyone? Not quite yet, but we've come very close | Amazing Science | Scoop.it

The dream of igniting a self-sustained fusion reaction with high yields of energy, a feat likened to creating a miniature star on Earth, is getting closer to becoming reality, according the authors of a new review article in the journal Physics of Plasmas. The image shows the preamplifiers of the National Ignition Facility. The unified lasers deliver 1.8 megajoules of energy and 500 terawatts of power -- 1,000 times more than the United States uses at any one moment.

 

Researchers at the National Ignition Facility (NIF) engaged in a collaborative project led by the Department of Energy's Lawrence Livermore National Laboratory, report that while there is at least one significant obstacle to overcome before achieving the highly stable, precisely directed implosion required for ignition, they have met many of the demanding challenges leading up to that goal since experiments began in 2010.

 

The project is a multi-institutional effort including partners from the University of Rochester's Laboratory for Laser Energetics, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory, and the Massachusetts Institute of Technology.

 

To reach ignition (defined as the point at which the fusion reaction produces more energy than is needed to initiate it), the NIF focuses 192 laser beams simultaneously in billionth-of-a-second pulses inside a cryogenically cooled hohlraum (from the German word for "hollow room"), a hollow cylinder the size of a pencil eraser. Within the hohlraum is a ball-bearing-size capsule containing two hydrogen isotopes, deuterium and tritium (D-T). The unified lasers deliver 1.8 megajoules of energy and 500 terawatts of power—1,000 times more than the United States uses at any one moment—to the hohlraum creating an "X-ray oven" which implodes the D-T capsule to temperatures and pressures similar to those found at the center of the sun.

 

"What we want to do is use the X-rays to blast away the outer layer of the capsule in a very controlled manner, so that the D-T pellet is compressed to just the right conditions to initiate the fusion reaction," explained John Edwards, NIF associate director for inertial confinement fusion and high-energy-density science. "In our new review article, we report that the NIF has met many of the requirements believed necessary to achieve ignition—sufficient X-ray intensity in the hohlraum, accurate energy delivery to the target and desired levels of compression—but that at least one major hurdle remains to be overcome, the premature breaking apart of the capsule."

 

In the article, Edwards and his colleagues discuss how they are using diagnostic tools developed at NIF to determine likely causes for the problem. "In some ignition tests, we measured the scattering of neutrons released and found different strength signals at different spots around the D-T capsule," Edwards said. "This indicates that the shell's surface is not uniformly smooth and that in some places, it's thinner and weaker than in others. In other tests, the spectrum of X-rays emitted indicated that the D-T fuel and capsule were mixing too much—the results of hydrodynamic instability—and that can quench the ignition process."

 

Edwards said that the team is concentrating its efforts on NIF to define the exact nature of the instability and use the knowledge gained to design an improved, sturdier capsule. Achieving that milestone, he said, should clear the path for further advances toward laboratory ignition.

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Fraunhofer Institute for Solar Energy: World Record Solar Cell with 44.7% Efficiency

Fraunhofer Institute for Solar Energy: World Record Solar Cell with 44.7% Efficiency | Amazing Science | Scoop.it

The Fraunhofer Institute for Solar Energy Systems ISE, Soitec, CEA-Leti and the Helmholtz Center Berlin jointly announced today having achieved a new world record for the conversion of sunlight into electricity using a new solar cell structure with four solar subcells. Surpassing competition after only over three years of research, and entering the roadmap at world class level, a new record efficiency of 44.7% was measured at a concentration of 297 suns. This indicates that 44.7% of the solar spectrum's energy, from ultraviolet through to the infrared, is converted into electrical energy. This is a major step towards reducing further the costs of solar electricity and continues to pave the way to the 50% efficiency roadmap.

Back in May 2013, the German-French team of Fraunhofer ISE, Soitec, CEA-Leti and the Helmholtz Center Berlin had already announced a solar cell with 43.6% efficiency. Building on this result, further intensive research work and optimization steps led to the present efficiency of 44.7%. 

These solar cells are used in concentrator photovoltaics (CPV), a technology which achieves more than twice the efficiency of conventional PV power plants in sun-rich locations. The terrestrial use of so-called III-V multi-junction solar cells, which originally came from space technology, has prevailed to realize highest efficiencies for the conversion of sunlight to electricity. In this multi-junction solar cell, several cells made out of different III-V semiconductor materials are stacked on top of each other. The single subcells absorb different wavelength ranges of the solar spectrum.

“We are incredibly proud of our team which has been working now for three years on this four-junction solar cell,” says Frank Dimroth, Department Head and Project Leader in charge of this development work at Fraunhofer ISE. “This four-junction solar cell contains our collected expertise in this area over many years. Besides improved materials and optimization of the structure, a new procedure called wafer bonding plays a central role. With this technology, we are able to connect two semiconductor crystals, which otherwise cannot be grown on top of each other with high crystal quality. In this way we can produce the optimal semiconductor combination to create the highest efficiency solar cells.” 

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Patricia Nicoll's curator insight, October 6, 2013 9:39 PM

I can't wait for the day that solar energy takes over all of our needs!

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3D printed objects outgrow their printers: How to create really big objects?

3D printing may be set to change the world by letting us make all sorts of bespoke objects, but there's one little problem: the printers can only print items smaller than themselves. Until now, that is.

 

Skylar Tibbits at the Massachusetts Institute of Technology's Self-Assembly Lab and colleague Marcelo Coelho have come up with a way for standard 3D printers to print out large-scale objects. "It's challenging the notion that we always need a machine that's bigger than the thing it's printing," says Tibbits.

The approach, called Hyperform, converts the object to be printed into a single long chain made from interlocking links. An algorithm works out how that chain can be packed together into the smallest cube possible using a Hilbert curve – a fractal-based pattern that is the most efficient way of squeezing a single line into a small as space as possible. The resulting cube is small enough to be printed inside a standard printer.

Once this cube is printed, the chain can be unravelled and assembled by hand to create the desired object. That's possible because each link in the chain has notches that allow it to bend only in a certain way. "You have to fold it by hand and click it into place," says Tibbits. Hyperform won the "The Next Idea" prize at the Ars Electronica 2013 technology festival in Linz, Austria, earlier this month.

But printing cubes made of such densely packed chains was too much for most of the consumer printers that Tibbits and his team tried. "We blew a lot of printers at first," he says. So they teamed up with Formlabs who, after a successful Kickstarter crowdfunding campaign, have just started shipping their Form 1 3D printer.

 

The Form 1 is capable of much higher resolution than standard consumer 3D printers. Instead of printing out layer upon layer of plastic, it uses stereolithography, in which a pool of liquid plastic is added to the base of the printer and a laser traces out the pattern required, causing the liquid plastic to cure and solidify. The technique can form layers just 25 microns thick, with details as small as 300 microns.

 

Hyperform has so far been used to create large structures such as a chandelier, and Tibbits sees it as being perfect for producing large 3D-printed consumer products. But the Form 1 printer uses resins which have limitations in terms of strength. "There is a range of things that are largish that we can do right away," says Tibbits. "But if you want to make large-scale furniture or buildings, there needs to be an approach to make them stronger."

Manually clicking each link into place isn't ideal either. That's where Tibbits' other work in so-called 4D printing might help. 4D printing uses materials that are 3D-printed to produce an intermediate object which, when exposed to water, will bend and twist itself into the final structure. "You can see how Hyperform and 4D printing are pointing towards each other," he says.

Clément Moreau, CEO of French 3D printing firm Sculpteo, says projects like Hyperform are shaping the future of 3D printing. "This is yet another example of how 3D printing is more of a flexible manufacturing process than injection moulding because it constantly opens up new possibilities in terms of materials used and shapes which can be printed."

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Undoing Down syndrome? Sonic Hedgehog reverses learning deficits in mice with trisomy 21 traits

Undoing Down syndrome? Sonic Hedgehog reverses learning deficits in mice with trisomy 21 traits | Amazing Science | Scoop.it

For people with trisomy 21 – more commonly known as Down syndrome – learning and remembering important concepts can be a struggle, since some of their brain’s structures do not develop as fully as they should.

But now, researchers may have found a way to reverse the learning deficits associated with Down syndrome, after having discovered a compound that can significantly bolster cognition in mice with a condition very similar to trisomy 21.

 

In a new study published in the Sept. 4 issue of Science Translational Medicine, scientists injected a small protein known as a sonic hedgehog pathway agonist into the brains of genetically engineered mice on the day of their birth.  The treatment enabled the rodents’ cerebellums to grow to a normal size, allowing them to perform just as well as unmodified mice in behavioral tests.

 

“We’ve been working for some time to characterize the basis for how people with trisomy 21 diverge in development from people without trisomy 21,” Roger Reeves, a professor in the McKusick-Nathans Institute of Genetic Medicine at the Johns Hopkins University School of Medicine, told FoxNews.com. “One of the early things we see is that people with Down syndrome have very small cerebellums, which does a lot more things than we used to think it did.”

 

Down syndrome is a condition that occurs when people receive three – rather than the typical two – copies of chromosome 21. Because of this “trisomy,” Down syndrome patients have extra copies of the more than 300 genes contained in that chromosome.  This leads to a range of symptoms, including mild to moderate intellectual disability, distinct facial features, heart defects and other health problems.

 

Through previous research, Reeves found that another distinct trait of people with Down syndrome is a cerebellum that’s approximately 60 percent of the normal size.  In order for this important brain region to grow and form, a small population of cells in the brain must quickly divide and multiply shortly after birth. This cell population requires a specific growth factor known as the sonic hedgehog pathway to stimulate the cells, triggering them to divide.

 

However, the trisomic cells in people with Down syndrome do not respond as well to this growth factor, stunting the development of the cerebellum – a region of the brain found to be important in cognitive processing and emotional control.

 

“We thought if we could stimulate these cells a bit at birth, we could make up the deficit,” Reeves said.  To test this theory, Reeves and his research team created a series of genetically engineered mice, all of which had extra copies of about half of the genes found in chromosome 21.  According to Reeves, this caused the mice to have many of the same characteristics seen in patients with Down syndrome, such as a smaller cerebellum and learning difficulties.

 

The researchers then injected the mice with a sonic hedgehog pathway agonist, which stimulates the growth factor pathway needed to trigger cerebellum development.   The compound was given to the mice just once on the day of birth. “From that one injection, we were able to normalize the growth of the cerebellum, and they continued to have a structurally normal cerebellum when they grew up,” Reeves said.

 

Going one step further, the researchers conducted a series of behavioral tests on the mice to better understand how normalizing this brain structure would affect their overall performance.  One of these tests was the Morris water maze test, an experiment that involves placing the mice in a pool of water and seeing how long it takes them to escape using a platform hidden below the water’s surface.  The test measures the rodents’ spatial learning and memory capabilities, which are primarily controlled by the hippocampus.

 

The sonic hedgehog agonist has yet to be proven effective in humans with Down syndrome, and future research is needed to determine exactly how the injection improved the mice’s cognitive abilities and whether or not the agonist has any side effects.  But Reeves remains hopeful that these findings could have translational potential.

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Elizabeth W.'s curator insight, March 25, 2014 10:40 AM

This article is proposing the possibility of treating people born with Down syndrome. It has been found that people with Down syndrome  have cerebellum's that are 60% of the size of a normal cerebellum which we plays a part in our cognitive and emotional functioning. The researchers are now studying if they can help the cerebellum grow at birth with an injected agonist. The study has been done with mice and showed some promising results but whether or not the mice are healthy overall still hasn't been determined. It will also take awhile before this is used on anybody with Down syndrome. 

If this is able to work and show promising results to help people with Down syndrome, it would be an amazing and radical change. However, from my perspective it seems that this type of thing would naturally have costs or risks associated with injecting the agonist and also there could be some ethical issues. "Do I inject my child with this agonist in hopes they will not experience the obstacles with Down syndrome or do I not knowing there could be a risk child?" I'm not sure what procedures would be taken place for this but I could see this issue coming up. 

Nick Ure's curator insight, December 17, 2014 11:18 AM

?- Questions 

Star- Important

Vocab- words you dont understand

HgI- How you get it

E- Effects on Life

D- Description of disease

 

in text citation (tristomy)

 

Vocab- Trisomy also know as down syndrome

 

E- Learning and remembering important concepts can be a real struggle  

 

E- Their brain structure does not fully develop as fully as they should

 

* They injected a small molecule known as a sonic hedgehog pathway agonist  into the brains of little mice that just were born. it enabled them to grow a normal size, allowing them to perform just as well.

 

D- One thing we see is that people with down syndrome have very small cerebellums.

 

D- Down syndrome is a common condition that occurs when people receive three. Than a two copies of chromosome 21. Patients have extra copies of more than 300 genes in the chromosome. This will lead to many symptoms like mild to moderate intellectual disability, distinct features, heart and other problems.

 

Cerebellum- is a region of the brain that plays an important role in motor control

 

HgI- If a small population of cells in the brain dont quickly divide and multiply shortly after birth you could get it. This requirers a current growth factor known as the sonic hedgehog pathway to stimulate the cells.  

 

D- They thought they could fix this disease a bit and they tried there medicine on mice first. They would inject them one on the day of birth.  From this one inject they are able to normalize the growth of the cerebellum and they continue to have a normal Cerebellum when they grow up. 

 

* This medicine has yet to be texted on humans with this disability and future research will be needed before they try and find how what the injection will do and why it improves the micas abilities. They dont know yet if it has side effects yet. If this works that would be amazing cause it could help a lot of people with down syndrome. 

 

 

 

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Description and first application of a new technique to measure the gravitational mass of antimatter

Description and first application of a new technique to measure the gravitational mass of antimatter | Amazing Science | Scoop.it

Researchers at Cern in Switzerland have tested a novel way to find out if antimatter is the source of a force termed "antigravity". Antimatter particles are the "mirror image" of normal matter, but with opposite electric charge.

How antimatter responds to gravity remains a mystery, however; it may "fall up" rather than down.

 

Now researchers reporting in Nature Communications have made strides toward finally resolving that notion. Antimatter presents one of the biggest mysteries in physics, in that equal amounts of matter and antimatter should have been created at the Universe's beginning.


Yet when the two meet, they destroy each other in what is called annihilation, turning into pure light. Why the Universe we see today is made overwhelmingly of matter, with only tiny amounts of antimatter, has prompted a number of studies to try to find some difference between the two.

 

Tests at Cern's LHCb experiment and elsewhere, for example, have been looking for evidence that exotic particles decay more often into matter than antimatter.

 

Last week, the LHCb team reported a slight difference in the decay of particles called Bs mesons - but still not nearly enough to explain the matter mystery.

 

One significant difference between the two may be the way they interact with gravity - antimatter may be repelled by matter, rather than attracted to it.

But it is a difference that no one has been able to test - until the advent of Cern's Alpha experiment. It's the first time that anyone has even been able to talk about doing this”, says Jeffrey Hangst, Alpha experiment spokesperson.


There are many compelling experimental and theoretical arguments that suggest that the gravitational mass of antimatter cannot differ from the gravitational or inertial mass of normal matter, that is, that the weak equivalence principle holds. For instance, one such argument comes from the absence of anomalies in Eötvös experiments conducted with differing atoms; the differing number of virtual particle–antiparticle pairs in such atoms might have caused gravitational anomalies to occur. However, all of these arguments are indirect and are not universally accepted. They rely on assumptions about the gravitational interactions of virtual antimatter, on postulates such as CPT invariance, or on other theoretical premises.

 

Although these arguments may well be correct, in a world in which physicists have only recently discovered that we cannot account for most of the matter and energy in the universe, it would be presumptuous to categorically assert that the gravitational mass of antimatter necessarily equals its inertial mass.

 

Moreover, the baryogenesis problem suggests that our understanding of antimatter is incomplete; gravitational asymmetries have been proposed as an explanation. 

 

There have not yet been any direct, free-fall or gravitational balance, tests of the gravitational interactions of observable matter and antimatter. Direct gravitational experiments with non-neutral antimatter, for example, isolated positrons or antiprotons, are exceedingly difficult because the electrical forces overwhelm the gravitational forces. Employing neutral antihydrogen or positronium eliminates this complication. The AEGIS project at CERN was formed to conduct direct experimental tests of gravity on antihydrogen, and is now in its final construction phase. A second experiment, GBAR, has recently been approved at CERN, and a third experiment was proposed at Fermilab.

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How to make ceramics that bend without breaking: Self-deploying medical devices?

How to make ceramics that bend without breaking: Self-deploying medical devices? | Amazing Science | Scoop.it
New materials could lead to actuators on a chip and self-deploying medical devices. Ceramics are not known for their flexibility: they tend to crack under stress.

 

The team has developed a way of making minuscule ceramic objects that are not only flexible, but also have a "memory" for shape: When bent and then heated, they return to their original shapes. The surprising discovery is reported this week in the journalScience, in a paper by MIT graduate student Alan Lai, professor Christopher Schuh, and two collaborators in Singapore.


Shape-memory materials, which can bend and then snap back to their original configurations in response to a temperature change, have been known since the 1950s, explains Schuh, the Danae and Vasilis Salapatas Professor of Metallurgy and head of MIT's Department of Materials Science and Engineering. "It's been known in metals, and some polymers," he says, "but not in ceramics."

 

In principle, the molecular structure of ceramics should make shape memory possible, he says -- but the materials' brittleness and propensity for cracking has been a hurdle. "The concept has been there, but it's never been realized," Schuh says. "That's why we were so excited."

 

The key to shape-memory ceramics, it turns out, was thinking small.

 

The team accomplished this in two key ways. First, they created tiny ceramic objects, invisible to the naked eye: "When you make things small, they are more resistant to cracking," Schuh says. Then, the researchers concentrated on making the individual crystal grains span the entire small-scale structure, removing the crystal-grain boundaries where cracks are most likely to occur.

Those tactics resulted in tiny samples of ceramic material -- samples with deformability equivalent to about 7 percent of their size. "Most things can only deform about 1 percent," Lai says, adding that normal ceramics can't even bend that much without cracking.

 

"Usually if you bend a ceramic by 1 percent, it will shatter," Schuh says. But these tiny filaments, with a diameter of just 1 micrometer -- one millionth of a meter -- can be bent by 7 to 8 percent repeatedly without any cracking, he says.

 

While a micrometer is pretty tiny by most standards, it's actually not so small in the world of nanotechnology. "It's large compared to a lot of what nanotech people work on," Lai says. As such, these materials could be important tools for those developing micro- and nanodevices, such as for biomedical applications. For example, shape-memory ceramics could be used as microactuators to trigger actions within such devices -- such as the release of drugs from tiny implants.


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A hidden genetic code for better designer genes

A hidden genetic code for better designer genes | Amazing Science | Scoop.it

Scientists routinely seek to reprogram bacteria to produce proteins for drugs, biofuels and more, but they have struggled to get those bugs to follow orders. But a hidden feature of the genetic code, it turns out, could get bugs with the program. The feature controls how much of the desired protein bacteria produce, a team from the Wyss Institute for Biologically Inspired Engineering at Harvard University reported in the September 26 online issue of Science.

The findings could be a boon for biotechnologists, and they could help synthetic biologists reprogram bacteria to make new drugs and biological devices.

 

By combining high-speed "next-generation" DNA sequencing and DNA synthesis technologies, Sri Kosuri, Ph.D., a Wyss Institute staff scientist, George Church, Ph.D., a core faculty member at the Wyss Institute and professor of genetics at Harvard Medical School, and Daniel Goodman, a Wyss Institute graduate research fellow, found that using more rare words, or codons, near the start of a gene removes roadblocks to protein production.

"Now that we understand how rare codons control gene expression, we can better predict how to synthesize genes that make enzymes, drugs, or whatever you want to make in a cell," Kosuri said.

 

To produce a protein, a cell must first make working copies of the gene encoding it. These copies, called messenger RNA (mRNA), consist of a specific string of words, or codons. Each codon represents one of the 20 different amino acids that cells use to assemble proteins. But since the cell uses 61 codons to represent 20 amino acids, many codons have synonyms that represent the same amino acid.

 

In bacteria, as in books, some words are used more often than others, and molecular biologists have noticed over the last few years that rare codons appear more frequently near the start of a gene. What's more, genes whose opening sequences have more rare codons produce more protein than genes whose opening sequences do not.

 

No one knew for sure why rare codons had these effects, but many biologists suspected that they function as a highway on-ramp for ribosomes, the molecular machines that build proteins. According to this idea, called the codon ramp hypothesis, ribosomes wait on the on-ramp, then accelerate slowly along the mRNA highway, allowing the cell to make proteins with all deliberate speed. But without the on-ramp, the ribosomes gun it down the mRNA highway, then collide like bumper cars, causing traffic accidents that slow protein production. Other biologists suspected rare codons acted via different mechanisms. These include mRNA folding, which could create roadblocks for ribosomes that block the highway and slow protein production.

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Astronomers Uncover a Millisecond 'Transformer' Pulsar with Magnetic Field Structure

Astronomers Uncover a Millisecond 'Transformer' Pulsar with Magnetic Field Structure | Amazing Science | Scoop.it

An international team of scientists using a fleet of orbiting X-ray telescopes, including NASA's Swift and Chandra X-ray Observatory, has discovered a millisecond pulsar with a dual identity. In a feat that has never before been observed, the star readily shifts back and forth between two mutually exclusive styles of pulsed emission -- one in X-rays, the other in radio.

 

The discovery, say scientists, represents a long-sought intermediate phase in the life of these powerful objects.

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Ancient oxygen discovery - 700 million years earlier - shakes up history of life on Earth

Ancient oxygen discovery - 700 million years earlier - shakes up history of life on Earth | Amazing Science | Scoop.it

Oxygen appeared in the Earth’s atmosphere up to 700 million years earlier than thought, according to a study led by a B.C. scientist, suggesting that revisions need to be made to current theories about how life evolved on Earth.

Up until now, scientists thought photosynthesis — the ability of living things such as algae and plants to harvest energy from the sun  — first evolved in single-celled organisms about 2.7 billion years ago.

 

Because oxygen is produced during photosynthesis, early photosynthetic organisms are thought to have given rise to the Great Oxygenation Event, also known as the Great Oxidation Event, about 2.3 billion years ago.

The incident was thought to be the first time the atmosphere began accumulating significant amounts of oxygen. That is significant because complex multicellular organisms such as humans require an oxygen-rich atmosphere to survive.

 

The new study led by biogeochemist Sean Crowe has found surprising evidence that as far back as three billion year ago, there were levels of oxygen in the atmosphere too high to have been produced without living organisms.

 

Crowe, an assistant professor in the department of Microbiology and Immunology and the department of Earth, Ocean and Atmospheric Sciences at the University of British Columbia, said people have detected traces of oxygen before in samples older than 2.3 billion years, but the signals were never strong enough to make a conclusion. That is partly because most ancient samples analyzed were marine sediments from the bottom of the ocean, which aren’t in direct contact with the atmosphere, and therefore don’t show very strong oxygen signals at the best of times.


However, researchers in South Africa recently discovered an ancient land-based soil sample called a paleosol that dated back three billion years.

Crowe, in collaboration with colleagues at the University of Southern Denmark, where he was previously a postdoctoral researcher, decided to test the samples for oxygen. The researchers employed a new, more sensitive technique that involves looking for forms of chromium that only occur following reaction with oxygen.

 

Given the age of the samples, Crowe didn’t expect to find any oxygen. So he was surprised when the tests showed “low but appreciable concentrations.”

 “Initially we thought we must have done something wrong or there was something wrong with the samples,” Crowe said.

 

To verify the results, researchers tested marine samples that were about the same age. Using the new chromium technique, they too showed a positive signal for oxygen.

 

“We were very excited,” Crowe said. “Immediately we knew there was oxygen in the atmosphere well before we understood it to be.”

 

The oxygen levels detected in the samples were only a 10,000th of present day levels of 20 per cent of the atmosphere, and a 200th to a 500th of the levels that immediately followed the Great Oxygenation Event.


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Wesley M Leonhardt's comment, October 1, 2013 8:34 PM
The earth's history will always be a mystery, and this article proves it. We have always been taught that the first oxygen on earth came from single celled organisms doing photosynthesis. This new study shows evidence of oxygen existing before these singled celled organisms. Using a soil sample called a paleosol, they discovered proof of oxygen in the soil billions of years ago. Even though oxygen levels were not as high as they are today, it still is a huge scientific discovery that will affect the learning of people in the future.
Wesley M Leonhardt's comment, October 1, 2013 8:39 PM
I feel like this will really affect the scientific thought of the evolution of the earth. The order of evolution will have to be reworked (yay for Adam and Eve!). I do believe that the earth will always have mysteries that we cant solve, but we can always try to solve them.
Wesley M Leonhardt's comment, October 1, 2013 8:41 PM
Chung, Emily. "Ancient Oxygen Discovery Shakes up History of Life on Earth - Technology & Science - CBC News." CBCnews. CBC/Radio Canada, 25 Sept. 2013. Web. 01 Oct. 2013. <http://www.cbc.ca/news/technology/ancient-oxygen-discovery-shakes-up-history-of-life-on-earth-1.1867976>.
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Breakthrough: A man controls robotic leg using thoughts alone

A man missing his lower leg has gained precise control over a prosthetic limb, just by thinking about moving it – all because his unused nerves were preserved during the amputation and rerouted to his thigh where they can be used to communicate with a robotic leg.

 

The man can now seamlessly switch from walking on level ground to climbing stairs and can even kick a football around.

 

During a traditional limb amputation, the main sensory nerves are severed and lose their function. In 2006, Todd Kuiken and his colleagues at the Rehabilitation Institute of Chicago in Illinois realised they could preserve some of that functionality by carefully rerouting sensory nerves during an amputation and attaching them to another part of the body.

They could then use the rerouted nerve signals to control a robotic limb, allowing a person to control their prosthesis with the same nerves they originally used to control their real limb.

 

Kuiken's team first attempted the procedure – which is called targeted muscle reinnervation (TMR) – on people who were having their arm amputated. Now, Kuiken's team has performed TMR for the first time on a man with a leg amputation.

 

First, the team rerouted the two main branches of the man's sciatic nerve to muscles in the thigh above the amputation. One branch controls the calf and some foot muscles, the other controls the muscle running down the outside leg and some more foot muscles.

 

After a few months, the man could control his thigh muscles by thinking about using his missing leg. The next step was to link up a prosthesis.

 

The robot leg in question is a sophisticated prosthesis: it carries a number of mechanical sensors including gyroscopes and accelerometers, and can be trained to use the information from these sensors to perform certain walking styles. Kuiken's team reckoned that the leg would perform even better if it could infer the user's intended walking style with information from the sciatic nerve.

 

To do so, the researchers asked their volunteer to attempt to perform certain movements with his missing leg – for instance, flexing the foot – while they monitored the pattern of electric signals from the rerouted nerves in the thigh muscles. The researchers then programmed the robot leg to flex its foot whenever it detected that particular pattern of electrical activity.

 

Using just the mechanical sensor data, the robotic leg made the correct movement about 87 per cent of the time. With additional data from the nerves, the success rate rose to 98 per cent, and there were no so-called critical errors – errors that increase the risk of the user losing balance and falling. Those kinds of errors are most common when the user suddenly shifts walking style – when they begin to climb stairs, for instance, but with the additional information from the nerves, the robotic leg can make a seamless, natural transition between walking styles (see video).

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Carlos Garcia Pando's comment, September 27, 2013 3:11 AM
Great idea. Thanks for posting
Madison Punch's comment, April 13, 2014 2:51 PM
Aha, where psychology meets physiology. I think this is amazing and definitely the best way for prosthetic limb users to activate their faux leg/arm/etc. Very cool!
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Next generation sequencing study finds ‘microbial profile’ may help determine time of death

Next generation sequencing study finds ‘microbial profile’ may help determine time of death | Amazing Science | Scoop.it

Using high-technology gene sequencing techniques on both bacteria and microbial eukaryotic organisms like fungi, nematodes and amoeba postmortem, the researchers were able to pinpoint time of mouse death after a 48-day period to within roughly four days. The results were even more accurate following an analysis at 34 days, correctly estimating the time of death within about three days, said Jessica Metcalf, a CU-Boulder postdoctoral researcher and first author on the study.

 

The paper on the subject was published Sept. 23, 2013, in the new online science and biomedical journal, eLIFE, a joint initiative of the Howard Hughes Medical Institute, the Max Planck Society and the Wellcome Trust Fund. The study was funded by the National Institute of Justice.

 

The researchers tracked microbial changes on the heads, torsos, body cavities and associated grave soil of 40 mice at eight different time points over the 48-day study. The stages after death include the “fresh” stage before decomposition, followed by “active decay” that includes bloating and subsequent body cavity rupture, followed by “advanced decay,” said Chaminade University forensic scientist David Carter, a co-author on the study.

 

“At each time point that we sampled, we saw similar microbiome patterns on the individual mice and similar biochemical changes in the grave soil,” said Laura Parfrey, a former CU-Boulder postdoctoral fellow and now a faculty member at the University of British Columbia who is a microbial and eukaryotic expert. “And although there were dramatic changes in the abundance and distribution of bacteria over the course of the study, we saw a surprising amount of consistency between individual mice microbes between the time points -- something we were hoping for.”

 

As part of the project, the researchers also charted “blooms” of a common soil-dwelling nematode well known for consuming bacterial biomass that occurred at roughly the same time on individual mice during the decay period. “The nematodes seem to be responding to increases in bacterial biomass during the early decomposition process, an interesting finding from a community ecology standpoint,” said Metcalf.

 

“This work shows that your microbiome is not just important while you’re alive,” said CU-Boulder Associate Professor Rob Knight, the corresponding study author who runs the lab where the experiments took place. “It might also be important after you're dead.”

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NASA's Innovative Ion Space Thruster Sets Endurance World Record

NASA's Innovative Ion Space Thruster Sets Endurance World Record | Amazing Science | Scoop.it

A five-year test of NASA's latest ion drive for future spacecraft has set a new world record for the longest single space engine test.

 

The space agency's Evolutionary Xenon Thruster (NEXT) project completed a continuous test the ion engine for more than 48,000 hours — over five and a half years — longer than any other space propulsion system ever tested. With low fuel weight and long-running efficiency, ion engines have become strong contenders for deep space missions.

 

Spacecraft traveling through miles of space require energy to keep moving. Ion propulsion engines can help to minimize the bulkiness of fuel, allowing for increased scientific exploration in smaller packages. Over the course of nearly six years, NEXT consumed only 1,900 pounds (860 kilograms) of fuel, compared to the 22,000 pounds (10,000 kg) a conventional rocket would burn to create the same momentum.

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World won't cool without substantial geoengineering, report finds

World won't cool without substantial geoengineering, report finds | Amazing Science | Scoop.it
The latest draft of the IPCC climate report says global warming is irreversible without schemes to suck carbon dioxide out of the atmosphere

 

Global warming is irreversible without massive geoengineering of the atmosphere's chemistry. This stark warning comes from the draft summary of the latest climate assessment by the Intergovernmental Panel on Climate Change.

 

Delegates from national governments are discussing the draft this week, prior to its release on Friday morning.

 

According to one of its lead authors, and the latest draft seen by New Scientist, the report will say: "CO2-induced warming is projected to remain approximately constant for many centuries following a complete cessation of emission. A large fraction of climate change is thus irreversible on a human timescale, except if net anthropogenic CO2 emissions were strongly negative over a sustained period."

 

In other words, even if all the world ran on carbon-free energy and deforestation ceased, the only way of lowering temperatures would be todevise a scheme for sucking hundreds of billions of tonnes of carbon dioxide out of the atmosphere.

 

Much of this week's report, the fifth assessment of the IPCC working group on the physical science of climate change, will reaffirm the findings of the previous four assessments, published regularly since 1990.

 

It will point out that to limit global warming to 2 °C will require cumulative CO2emissions from all human sources since the start of the industrial revolution to be kept below about a trillion tonnes of carbon. So far, we have emitted about half this. Current emissions are around 10.5 billion tonnes of carbon annually, and rising.

 

Since the last assessment, published in 2007, the IPCC has almost doubled its estimate of the maximum sea-level rise likely in the coming century to about 1 metre. They also conclude that it is now "virtually certain" that sea levels will continue to rise for many centuries, even if warming ceases, due to the delayed effects of thermal expansion of warming oceans and melting ice sheets.

 

The draft report says the available evidence now suggests that above a certain threshold of warming, the Greenland ice sheet will almost disappear within approximately 1000 years, which will result in 7 metres of global sea-level rise. It estimates that the threshold may lie between 1 °C and 4 °C of warming, but is not confident of this figure.

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Google Converted Language Translation Into a Problem of Vector Space Mathematics

Google Converted Language Translation Into a Problem of Vector Space Mathematics | Amazing Science | Scoop.it
To translate one language into another, find the linear transformation that maps one to the other. Simple, say a team of Google engineers

 

Computer science is changing the nature of the translation of words and sentences from one language to another. Anybody who has tried BabelFish or Google Translate will know that they provide useful translation services but ones that are far from perfect.

 

The basic idea is to compare a corpus of words in one language with the same corpus of words translated into another. Words and phrases that share similar statistical properties are considered equivalent.

 

The problem, of course, is that the initial translations rely on dictionaries that have to be compiled by human experts and this takes significant time and effort.

 

Now Tomas Mikolov and a couple of pals at Google in Mountain View have developed a technique that automatically generates dictionaries and phrase tables that convert one language into another. The new technique does not rely on versions of the same document in different languages. Instead, it uses data mining techniques to model the structure of a single language and then compares this to the structure of another language.

 

“This method makes little assumption about the languages, so it can be used to extend and refine dictionaries and translation tables for any language pairs,” they say. The new approach is relatively straightforward. It relies on the notion that every language must describe a similar set of ideas, so the words that do this must also be similar. For example, most languages will have words for common animals such as cat, dog, cow and so on. And these words are probably used in the same way in sentences such as “a cat is an animal that is smaller than a dog.”

 

The same is true of numbers. The image above shows the vector representations of the numbers one to five in English and Spanish and demonstrates how similar they are. This is an important clue. The new trick is to represent an entire language using the relationship between its words. The set of all the relationships, the so-called “language space”, can be thought of as a set of vectors that each point from one word to another. And in recent years, linguists have discovered that it is possible to handle these vectors mathematically. For example, the operation ‘king’ – ‘man’ + ‘woman’ results in a vector that is similar to ‘queen’.

 

It turns out that different languages share many similarities in this vector space. That means the process of converting one language into another is equivalent to finding the transformation that converts one vector space into the other.

 

Having identified this mapping, it is then a simple matter to apply it to the bigger language spaces. Mikolov and co say it works remarkably well. “Despite its simplicity, our method is surprisingly effective: we can achieve almost 90% precision@5 for translation of words between English and Spanish,” they say.

 

The method can be used to extend and refine existing dictionaries, and even to spot mistakes in them. Indeed, the Google team do exactly that with an English-Czech dictionary, finding numerous mistakes. Finally, the team point out that since the technique makes few assumptions about the languages themselves, it can be used on argots that are entirely unrelated. So while Spanish and English have a common Indo-European history, Mikolov and co show that the new technique also works just as well for pairs of languages that are less closely related, such as English and Vietnamese.

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