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Is the Universe a Simulation and are there Ways to Test it?

Is the Universe a Simulation and are there Ways to Test it? | Amazing Science | Scoop.it
If so, that would help explain some mysterious things about math.


Mathematical knowledge is unlike any other knowledge. Its truths are objective, necessary and timeless. What kinds of things are mathematical entities and theorems, that they are knowable in this way? Do they exist somewhere, a set of immaterial objects in the enchanted gardens of the Platonic world, waiting to be discovered? Or are they mere creations of the human mind?


This question has divided thinkers for centuries. It seems spooky to suggest that mathematical entities actually exist in and of themselves. But if math is only a product of the human imagination, how do we all end up agreeing on exactly the same math? Some might argue that mathematical entities are like chess pieces, elaborate fictions in a game invented by humans. But unlike chess, mathematics is indispensable to scientific theories describing our universe. And yet there are many mathematical concepts — from esoteric numerical systems to infinite-dimensional spaces — that we don’t currently find in the world around us. In what sense do they exist?


Many mathematicians, when pressed, admit to being Platonists. The great logician Kurt Gödel argued that mathematical concepts and ideas “form an objective reality of their own, which we cannot create or change, but only perceive and describe.” But if this is true, how do humans manage to access this hidden reality?


We don’t know. But one fanciful possibility is that we live in a computer simulation based on the laws of mathematics — not in what we commonly take to be the real world. According to this theory, some highly advanced computer programmer of the future has devised this simulation, and we are unknowingly part of it. Thus when we discover a mathematical truth, we are simply discovering aspects of the code that the programmer used.


This may strike you as very unlikely. But the Oxford philosopher Nick Bostrom has argued that we are more likely to be in such a simulation than not. If such simulations are possible in theory, he reasons, then eventually humans will create them — presumably many of them. If this is so, in time there will be many more simulated worlds than nonsimulated ones. Statistically speaking, therefore, we are more likely to be living in a simulated world than the real one.


Very clever. But is there any way to empirically test this hypothesis? Indeed, there may be. In a recent paper, “Constraints on the Universe as a Numerical Simulation,” the physicists Silas R. Beane, Zohreh Davoudi and Martin J. Savage outline a possible method for detecting that our world is actually a computer simulation. Physicists have been creating their own computer simulations of the forces of nature for years — on a tiny scale, the size of an atomic nucleus. They use a three-dimensional grid to model a little chunk of the universe; then they run the program to see what happens. This way, they have been able to simulate the motion and collisions of elementary particles.


But these computer simulations, Professor Beane and his colleagues observe, generate slight but distinctive anomalies — certain kinds of asymmetries. Might we be able to detect these same distinctive anomalies in the actual universe, they wondered? In their paper, they suggest that a closer look at cosmic rays, those high-energy particles coming to Earth’s atmosphere from outside the solar system, may reveal similar asymmetries. If so, this would indicate that we might — just might — ourselves be in someone else’s computer simulation.


Are we prepared to take the “red pill,” as Neo did in “The Matrix,” to see the truth behind the illusion — to see “how deep the rabbit hole goes”? Perhaps not yet. The jury is still out on the simulation hypothesis. But even if it proves too far-fetched, the possibility of the Platonic nature of mathematical ideas remains — and may hold the key to understanding our own reality.


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Rice’s carbon nanotube fibers outperform copper in regards to carry electrical current

Rice’s carbon nanotube fibers outperform copper in regards to carry electrical current | Amazing Science | Scoop.it

On a pound-per-pound basis, carbon nanotube-based fibers invented at Rice University have greater capacity to carry electrical current than copper cables of the same mass, according to new research.


While individual nanotubes are capable of transmitting nearly 1,000 times more current than copper, the same tubes coalesced into a fiber using other technologies fail long before reaching that capacity.

But a series of tests at Rice showed the wet-spun carbon nanotube fiber still handily beat copper, carrying up to four times as much current as a copper wire of the same mass.


That, said the researchers, makes nanotube-based cables an ideal platform for lightweight power transmission in systems where weight is a significant factor, like aerospace applications.


The analysis led by Rice professors Junichiro Kono and Matteo Pasquali appeared online this week in the journal Advanced Functional Materials. Just a year ago the journal Science reported that Pasquali’s lab, in collaboration with scientists at the Dutch firm Teijin Aramid, created a very strong conductive fiber out of carbon nanotubes.


Present-day transmission cables made of copper or aluminum are heavy because their low tensile strength requires steel-core reinforcement.


Scientists working with nanoscale materials have long thought there’s a better way to move electricity from here to there. Certain types of carbon nanotubes can carry far more electricity than copper. The ideal cable would be made of long metallic “armchair” nanotubes that would transmit current over great distances with negligible loss, but such a cable is not feasible because it’s not yet possible to manufacture pure armchairs in bulk, Pasquali said.


In the meantime, the Pasquali lab has created a method to spin fiber from a mix of nanotube types that still outperforms copper. The cable developed by Pasquali and Teijin Aramid is strong and flexible even though at 20 microns wide, it’s thinner than a human hair.

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Zircon crystal found on an Australian sheep ranch is the oldest known piece of our planet

Zircon crystal found on an Australian sheep ranch is the oldest known piece of our planet | Amazing Science | Scoop.it
Scientists have shown that a tiny zircon crystal found on a sheep ranch in western Australia is the oldest known piece of our planet, dating to 4.4 billion years ago.


John Valley, a University of Wisconsin geoscience professor who led the research, said the findings suggest that the early Earth was not as harsh a place as many scientists have thought.

To determine the age of the zircon fragment, the scientists first used a widely accepted dating technique based on determining the radioactive decay of uranium to lead in a mineral sample.


But because some scientists hypothesised that this technique might give a false date due to possible movement of lead atoms within the crystal over time, the researchers turned to a second sophisticated method to verify the finding.


They used a technique known as atom-probe tomography that was able to identify individual atoms of lead in the crystal and determine their mass, and confirmed that the zircon was indeed 4.4 billion years old.


To put that age in perspective, the Earth itself formed 4.5 billion years ago as a ball of molten rock, meaning that its crust formed relatively soon thereafter, 100 million years later. The age of the crystal also means that the crust appeared just 160 million years after the very formation of the solar system.


The finding supports the notion of a "cool early Earth" where temperatures were low enough to sustain oceans, and perhaps life, earlier than previously thought, Professor Valley said.


This period of Earth history is known as the Hadean eon, named for ancient Greek god of the underworld Hades because of hellish conditions including meteorite bombardment and an initially molten surface.


"One of the things that we're really interested in is: when did the Earth first become habitable for life? When did it cool off enough that life might have emerged?" Professor Valley said.


The discovery that the zircon crystal, and thereby the formation of the crust, dates from 4.4 billion years ago suggests that the planet was perhaps capable of sustaining microbial life 4.3 billion years ago, Valley said.

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Evidence of an asteroid encountering a pulsar

Evidence of an asteroid encountering a pulsar | Amazing Science | Scoop.it
Asteroids hit the Earth, the Moon and even, it seems, distant stars.


Scientists using CSIRO's Parkes telescope and another telescope in South Africa have found evidence that a tiny star called PSR J0738-4042 is being pounded by asteroids — large lumps of rock from space. "One of these rocks seems to have had a mass of about a billion tonnes," CSIRO astronomer and member of the research team Dr Ryan Shannon said. PSR J0738-4042 lies 37,000 light-years from Earth in the constellation of Puppis. The environment around this star is especially harsh, full of radiation and violent winds of particles. "If a large rocky object can form here, planets could form around any star. That's exciting," Dr Shannon said. The star is a special one, a 'pulsar' that emits a beam of radio waves.


As the star spins, its radio beam flashes over Earth again and again with the regularity of a clock. In 2008 Dr Shannon and a colleague predicted how an infalling asteroid would affect a pulsar. It would, they said, alter the slowing of the pulsar's spin rate and the shape of the radio pulse that we see on Earth. "That is exactly what we see in this case," Dr Shannon said.


"We think the pulsar's radio beam zaps the asteroid, vaporising it. But the vaporised particles are electrically charged and they slightly alter the process that creates the pulsar's beam." Asteroids around a pulsar could be created by the exploding star that formed the pulsar itself, the scientists say.


The material blasted out from the explosion could fall back towards the forming pulsar, forming a disk of debris. Astronomers have found a dust disk around another pulsar called J0146+61.


"This sort of dust disk could provide the 'seeds' that grow into larger asteroids," said Mr Paul Brook, a PhD student co-supervised by the University of Oxford and CSIRO who led the study of PSR J0738-4042.

In 1992 two planet-sized objects were found around a pulsar called PSR 1257+12.  But these were probably formed by a different mechanism, the astronomers say.

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Amazing Muscle Made of Fishing Line Is 100 Times Stronger Than Biological Muscle

Amazing Muscle Made of Fishing Line Is 100 Times Stronger Than Biological Muscle | Amazing Science | Scoop.it

The high cost of powerful, large-stroke, high-stress artificial muscles has combined with performance limitations such as low cycle life, hysteresis, and low efficiency to restrict applications.


A team of material scientists at the University of Texas at Dallas have just discovered a new way to create powerful artificial muscles—synthetic sinew that forcefully expands and contracts on command—from low-cost, everyday fibers such as fishing line and high-tension sewing thread. In a study published today in the journal Science¸ the researchers described how they're doing it: by twisting the materials into springy and energy-dense coils. 

Extreme twisting produces coiled muscles that can contract by 49%, lift loads over 100 times heavier than can human muscle of the same length and weight, and generate 5.3 kilowatts of mechanical work per kilogram of muscle weight, similar to that produced by a jet engine. Woven textiles that change porosity in response to temperature and actuating window shutters that could help conserve energy were also demonstrated. Large-stroke tensile actuation was theoretically and experimentally shown to result from torsional actuation.


The researchers take polyethylene or nylon string, the plastics that can make up fishing line, and twist it under high tension over and over again. Once the plastic can't twist any more, it starts to coil up on itself like a curled telephone cord. This tightly bound coil is then temperature treated so that it's locked into place. 

When this coil is heated, the plastic tries to untwist. But this causes the entire thing to compress. "At first it seems confusing, but you can think of it kind of like a Chinese finger-trap," Baughman says. "Expanding the volume of the finger-trap, or heating the coil, actually makes the device shorten." And this is compounded by the fact that the molecules in polyethylene and nylon string also naturally contract lengthwise ever-so-slightly when they're heated. Together these effects make the plastic coil contract with incredible power—like a muscle. 

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Taylor Godbolt's curator insight, March 7, 2014 8:09 AM

This article was factual

Taylor Godbolt's comment, March 12, 2014 12:54 PM
Amazing Muscle Made of Fishing Line Is 100 Times Stronger Than Biological Muscle<br><br>Author: William Herkewitz<br>Date: Feb. 20, 2014<br><br>Main Idea: Newest material that is stronger than the stuff we have stuck in our body, muscle.<br><br>Summary: This material is artificial muscle that is flexible, dynamic, and can be used many times.<br><br>Importance: It was an experiment in which you have to use many things and test.<br><br>www.populermechanics.com <br>
Celest Ybarra's curator insight, March 30, 2014 4:38 PM

Title: Amazing Muscle Made of Fishing Line is 100 Times Stronger Than Biological Muscle

Author: William Herkewitz

Main Idea: A new type of material that is made with a fishing line is used to make artificial muscles

Summary:

1) The material is flexible, dynamic, reusable, and is designed to be better and stronger compared to our biological muscle

2) The 'muscles' are made of inexpensive plastic strings and wires

3) Can be used in many things

Opinion: The text was factual

Question: How was it created? Will it help further advances for humans or technology?

Is this article important to science?: Yes, because it shows how much we are advancing in technology.

Source: http://www.popularmechanics.com/science/health/breakthroughs/synthetic-muscle-made-of-fishing-line-is-100-times-stronger-than-the-real-thing-16514805

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Monkeys control each other's movement via computer link

Monkeys control each other's movement via computer link | Amazing Science | Scoop.it

Scientists have successfully used computer chips to link two monkeys together, allowing one monkey's brain to control the other's body movement. Researchers say they hope their work - partly inspired by Hollywood blockbuster Avatar - will lead to the development of implants for patients who have nerve or spinal cord paralysis.


Harvard neurosurgeon Ziv Williams, who co-authored the study published in the journal Nature Communications, says the paper aimed to find possible ways to treat people with cervical spinal cord injuries and are quadriplegic or have had brain stem strokes.


"What we basically did was create a functional cortical to spinal bypass where we're able to record neural signals in the brain, extract information about what the monkey is intending on doing and then basically stimulating the spinal cord to produce movements in their paralysed limb to those same intended target locations," Dr Williams said.


"For example, if the monkey is intending on moving upwards, we would select specific electrode contacts in the spinal cord to stimulate a movement that reaches that exact same target location. "In some cases actually the first monkey just needed to think about what they wanted to do and then the other monkey would make the movement."


Dr Williams said the "master monkey" was implanted with a microchip in the area of their brain responsible for thinking about movement and the neurons were recorded, based on the patterns of activity.


"We could figure out what the monkey was intending on moving or intending on doing - for example you know, moving up, down, left, right - and then at the same time we implanted a microchip in the spinal cord of the avatar and then we stimulated those areas based on what the other monkey was thinking," he said.


"So the hook-up was basically a computational link where we basically matched everything that the monkey, that the master, was thinking about and then matched that with movements produced in the avatar.

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2 Billion years-old trapped helium-4 gas released in large quantities at Yellowstone National Park

2 Billion years-old trapped helium-4 gas released in large quantities at Yellowstone National Park | Amazing Science | Scoop.it

Vast stores of helium are escaping from the steam vents and hot springs of Yellowstone National Park after being trapped within Earth's crust for up to 2 billion years, according to new research.


In fact, researchers say, the escaping helium -- about 60 tons per year --  is enough to fill one Goodyear blimp every week.

They also calculate that this "sudden" release of gas began roughly 2 million years ago, with the advent of volcanic activity there.

"That might seem like a really, really long time to people, but in the geologic time scale, the volcanism is a recent phenomenon," said study coauthor Bill Evans, a research chemist at the USGS office in Menlo Park, Calif.


Helium, or more accurately the isotope helium-4, is produced in Earth's crust as uranium and thorium decay. Often, this nonradioactive, crustal helium is swept away by groundwater, or freed as a result of tectonic movement.


But in areas where there is little groundwater or movement in Earth's crust, helium-4 can remain trapped and build up over time. This is especially true at Yellowstone, where inactive rocks, or what geologists call "craton," have been estimated to be 2.5 billion years old. The park is located primarily in Wyoming.


"The Yellowstone crust is among the oldest on Earth, and for most of its history had been part of the tectonically moribund core of North America," said lead study author Jacob Lowenstern, a research geologist and scientist-in-charge of the Yellowstone Volcano Observatory.


Things began to change roughly 2 million years ago, however,  when hot magma intruded on the crustal system from below and triggered several enormous volcanic eruptions, the most recent about 640,000 years ago.  


"Think of it this way: You have these old crustal rocks just sitting around for hundreds of millions, perhaps billions of years," Evans said. "They have this boring little existence, and then suddenly somebody puts the heat on under them and they start giving up all their long-held secrets."


Yellowstone's so-called magma "hot spot" still exists, and gives rise to the park's numerous and crowd-pleasing geysers, hot springs and fumaroles.


The researchers said the discovery of high levels of helium was a result of their investigations into volcanic activity at the park, and came as a surprise.

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Katie Vazquez's curator insight, February 23, 2014 7:48 PM

Title: 2 Billion years-old trapped helium-4 gas released in large quantities at Yellowstone National Park

Author: Monte Morin

Date: February 19, 2014

 

Main Idea: Large quantities of helium that's up to 2 billion years old is escaping from steam vents and hot springs of Yellowstone National Park.

 

Summary:

1. 60 tons of the escaping helium per year is enough to fill one Goodyear blimp every week.

2. Helium is created in the Earth's crust as uranium and thorium decay.

3. Helium can remain trapped and build up as time goes in areas where there's little groundwater or movement in the Earth's crust.

 

Opinion/POV: I didn't see an opinion nor POV in this article.

 

Question: Is it dangerous to have that much helium escape at once?

 

Is this article important to science? Why? 

 

Yes, this article is important to science because it talks about what can happen if helium is trapped within the Earth's crust for a long period of time.

 

Source: http://www.latimes.com/science/sciencenow/la-sci-sn-yellowstone-helium-degassing-20140218,0,1665876.story#axzz2toFIavqe

Celest Ybarra's curator insight, March 29, 2014 8:43 PM

Title: 2 Billion years- old trapped helium-4 gas released in large quantities at Yellowstone National Park

Author: Monte Morin

Main Idea: Large amounts of helium-4 gas was escaping from the steam vents and hot springs of Yellowstone National Park after being trapped within Earth's crust for up to 2 billion years

Summary:

1) The national park was releasing hundreds -- if not thousands -- of times more helium than anticipated.

2) Helium is produced in Earth's crust as uranium and thorium decay. 3) Swept away by groundwater, or freed as a result of tectonic movement

Opinion: There was no opinion in this article because it was based off of facts

Question: Can this be harmful to our environment?

Is this article important to science?: Yes, because it gives readers insight on what can happen to the Earth when helium is trapped inside of it for too long.
Sources: http://www.latimes.com/science/sciencenow/la-sci-sn-yellowstone-helium-degassing-20140218,0,1665876.story#axzz2toFIavqe

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Researchers propose a better way to make sense of 'Big Data'

Researchers propose a better way to make sense of 'Big Data' | Amazing Science | Scoop.it

Two researchers at Cold Spring Harbor Laboratory challenge the most recent advances in this Big Data analysis, using a classic mathematical concept to tackle the outstanding problems in this field. Mutual information is able to uncover patterns in large lists of numbers, revealing entirely new, unexpected patterns.

Big Data is everywhere, and we are constantly told that it holds the answers to almost any problem we want to solve. Companies collect information on how we shop, doctors and insurance companies gather our medical test results, and governments compile logs of our phone calls and emails. In each instance, the hope is that critical insights are hidden deep within massive amounts of information, just waiting to be discovered.

But simply having lots of data is not the same as understanding it. Increasingly, new mathematical tools are needed to extract meaning from enormous data sets. In work published online today, two researchers at Cold Spring Harbor Laboratory (CSHL) now challenge the most recent advances in this field, using a classic mathematical concept to tackle the outstanding problems in Big Data analysis.


What does it mean to analyze Big Data? A major goal is to find patterns between seemingly unrelated quantities, such as income and cancer rates. Many of the most common statistical tools are only able to detect patterns if the researcher has some expectation about the relationship between the quantities. Part of the lure of Big Data is that it may reveal entirely new, unexpected patterns. Therefore, scientists and researchers have worked to develop statistical methods that will uncover these novel relationships.


In 2011, a distinguished group of researchers from Harvard University published a highly influential paper in the journal Science that advanced just such a tool. But in a paper published today in Proceedings of the National Academy of Sciences, CSHL Quantitative Biology Fellow Justin Kinney and CSHL Assistant Professor Gurinder "Mickey" Atwal demonstrate that this new tool is critically flawed. "Their statistical tool does not have the mathematical properties that were claimed," says Kinney.


Kinney and Atwal show that the correct tool was hiding in plain sight all along. The solution, they say, is a well known mathematical measure called "mutual information," first described in 1948. It was initially used to quantify the amount of information that could be transmitted electronically through a telephone cable; the concept now underlies the design of the world's telecommunications infrastructure. "What we've found in our work is that this same concept can also be used to find patterns in data," Kinney explains. "This beautiful mathematical concept has the potential to greatly benefit modern data analysis, in biology and in biology and many other important fields.

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Quantum Microscope May Be Able to See Fine Details Inside Living Cells

Quantum Microscope May Be Able to See Fine Details Inside Living Cells | Amazing Science | Scoop.it

By combining quantum mechanical quirks of light with a technique called photonic force microscopy, scientists can now probe detailed structures inside living cells like never before. This ability could bring into focus previously invisible processes and help biologists better understand how cells work.


Photonic force microscopy is similar to atomic force microscopy, where a fine-tipped needle is used to scan the surface of something extremely small such as DNA. Rather than a needle, researchers used extremely tiny fat granules about 300 nanometers in diameter to map out the flow of cytoplasm inside yeast cells with high precision.


To see where these miniscule fat particles were, they shined a laser on them. Here, the researchers had to rely on what’s known as squeezed light. Photons of light are inherently noisy and because of this, a laser beam’s light particles won’t all hit a detector at the same time. There is a slight randomness to their arrival that makes for a fuzzy picture. But squeezed light uses quantum mechanical tricks to reduce this noise and clear up the fuzziness.


“The essential idea was to use this noise-reduced light to locate the nano-particles inside a cell,” said physicist Warwick Bowen of the University of Queensland in Australia, co-author of a paper that came out Feb. 4 in Physical Review X.


The reason behind all this was to overcome a fundamental optical limit that has always caused headaches for biologists. The diffraction limit of light puts a constraint on the size of something you can resolve with a microscope for a given wavelength of light. For visible wavelengths, this limit is about 250 nanometers. Anything smaller can’t be easily seen. The trouble is, a lot of structures inside of cells, including organelles, cytoskeletons, and individual proteins, are much smaller than this.


Scientists have come up with clever ways to get around the diffraction limit and resolve things as small as 20 nanometers. But the new quantum technique has pushed that limit even farther. Instead of using light, Bowen’s team passed a nano-particle over the surface of cellular structures, sort of like running your finger over a bumpy surface. They held onto their fat granule probe using optical tweezers, which are basically a nanoscale version of a tractor beam. In an optical tweezer, scientists create a laser beam with an electromagnetic field along its length. The field is strongest at the center of the beam, allowing tiny objects to be drawn to this point and held there.


Because the fat granules occur naturally, the cells don’t need to be prepared like they would for atomic force microscopy, which generally involves killing the cells. That’s a big deal because it means photonic force microscopy can be used to visualize processes inside living cells. The team has tracked these granules with a resolution of about 10 nanometers.

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Curves alter crystallization, study finds

Curves alter crystallization, study finds | Amazing Science | Scoop.it
A new study has uncovered a previously unseen phenomenon — that curved surfaces can dramatically alter the shape of crystals as they form.


Scientists have studied crystallization since the time of Galileo, so it’s easy to imagine there’s nothing new to learn about the process. Harvard researchers might beg to differ.


A new study has uncovered a previously unseen phenomenon — that curved surfaces can dramatically alter the shape of crystals as they form. The finding could have applications ranging from applying coatings to nanoparticles used in industry to aiding in drug delivery, and may even help shed light on how viruses assemble. The work, conducted by researchers at Harvard’s Materials Research Science and Engineering Center and funded by the National Science Foundation, is described in a recent paper in Science.


To investigate how curved surfaces affect crystallization, Vinothan Manoharan, the Gordon McKay Professor of Chemical Engineering and a professor of physics, worked with physics postdoc Guangnan Meng to develop a system in which nanoscale colloidal particles were injected into water droplets. As the particles — about 10,000 times larger than atoms or molecules — organized themselves into crystalline structures, researchers were able to observe the process in real time.


“If you have the particles on a flat surface, like a piece of glass, they form a regular lattice, and they’re compact, with no preferred direction for crystal growth,” Manoharan said. “On a curved surface, however, they form a very different pattern. It looks like strips — almost like ribbons — and they branch out from different points.”


Importantly, Manoharan said, researchers found that changing the curvature of the surface — by changing the radius of the water droplet — resulted in changes to the crystalized “ribbons.”

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Ronan Delisle's curator insight, October 21, 2014 5:42 AM

ajouter votre point de vue ...

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Eagle eyes versus human eyes

Eagle eyes versus human eyes | Amazing Science | Scoop.it
Eagle vision would mean 20/4 resolution, built-in magnifying glasses, and the ability to perceive an inconceivable array of colors.


Eagles fly at an altitude of thousands of meters, in a manner similar to modern war planes, yet are able to comb the landscape below in staggering detail. The eagle can detect even the slightest of movements or color changes while in flight. It owes this ability to a very special eye structure. However, eagle's eyes cannot zoom. It can see sharp images from a distance. 

In humans, the portion of the retina with the most acute vision is the fovea centralis, which has the highest concentration of cone cells. Eagles have two foveae, giving them an incredibly sharp sense of sight. Humans have only one fovea in each eye-for binocular, or forward vision. When we look at an object, both our eyes are directed toward the object. This allows our brain to merge both the images to create a sense of depth. The eagle contains a binocular fovea like ours, but also has a fovea for monocular vision that allows each eye to look sideways and see a separate image. So eagles can see both forward and to the side at the same time. 

The eagle has a visual perspective of some 300 degrees, as well as an extra focusing power. Humans change the shape of their lenses to focus. But an eagle can change the shape of both lens and cornea. This gives it extra focusing power. It can also scan a 30,000-hectare (116-square mile) field from an altitude of 4,500 meters (14,700 feet), or spot a camouflaged rabbit from 90 meters (300 feet) with ease. 

To attain this super-sharp vision, an eagle's retinal cells are tinted with special colored oil droplets, increasing the contrast for objects seen against the blue sky or green forest. Thanks to this, the eagle can spot minute changes in contrast from thousands of meters above and swoop down to hunt. 

Coming to lenses, they are made glasses and can be focussed and/or zoomed according to our wish. There can be a variety of different lenses, from wide-angle to telephoto lengths. A camera lens can create a brighter picture with less light than an eye can, simply because it can collect light over a period of time. The eye can only use the light visible at one instant.


If you swapped your eyes for an eagle's, you could see an ant crawling on the ground from the roof of a 10-story building. You could make out the expressions on basketball players' faces from the worst seats in the arena. Objects directly in your line of sight would appear magnified, and everything would be brilliantly colored, rendered in an inconceivable array of shades.


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A Secret World Lies Beneath The Waves: Ocean Drifters

"Ocean Drifters, a secret world beneath the waves" is written, produced and directed by Dr Richard Kirby (Marine Institute Research Fellow, Plymouth University) with a narration by Sir David Attenborough and music by Richard Grassby-Lewis.


Drawing upon Richard Kirby's plankton imagery, Ocean Drifters reveals how the plankton have shaped life on Earth and continue to influence our lives in ways that most of us never imagine.


Further information about the plankton can be found at the Ocean Drifters website (oceandrifters.org) and in the popular book about plankton also titled "Ocean Drifters, a secret world beneath the waves".

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Marian Locksley's curator insight, March 10, 2014 4:22 AM

10.3.14 ~ 

Citizen science study to map the oceans' plankton

By Mark KinverEnvironment reporter, BBC News

 

http://www.bbc.co.uk/news/science-environment-26483166

 

 

Without these ancient cells, you wouldn’t be here BY REBECCA JACOBSON  March 6, 2014 

http://www.pbs.org/newshour/updates/tiny-ocean-organism-brought-earth-life/

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Strange Star Chemistry May Reveal Secrets of Planetary Disks

Strange Star Chemistry May Reveal Secrets of Planetary Disks | Amazing Science | Scoop.it
The observation of unexpected chemicals in the planet-forming disk around a young star indicate that such disks may be more complicated than previously anticipated.


An international team of scientists used the giant ALMA radio telescope in Chile's Atacama Desert to detect significant chemical changes in the star's dust cloud along a region known as the centrifugal barrier, where the pull of gravity no longer overcomes the centrifugal force rotating the gas.


"Spectral lines of these minor [chemical] species are faint, because of their low abundances," lead scientist Nami Sakai of the University of Tokyo told Space.com in an email. Sakai led the team of scientists that studied the young star and its gas cloud about 450 light-years from Earth. "But we were able to observe them, thanks to the high sensitivity of ALMA, and succeeded in discovering the drastic chemical change at the centrifugal barrier. No such exploration has been done before."


Gravity draws clouds of gas in space together to form new stars at their center. The gas left behind after the stellar birth continues to rotate around the new star, forming a disk that is further surrounded by an envelope of gas. Using the changing chemistry that exists at the border, the team could precisely mark the boundary of the two.


Scientists can probe these regions by studying the spectral lines emitted by simple molecules such as carbon monoxide. As technology has improved, other simple gases have been observed within such clouds, and the completion of ALMA and its high sensitivity and spatial resolution is expected to result in even more molecules, such as the cyclic-cyclopropenylidene (C3H2) and sulfur monoxide (SO) detected by Sakai's team.


Cyclic-C3H2 has been detected in a variety of regions of space, where it plays a key role in producing other hydrocarbons, but the highly-reactive molecule can only be found on laboratories on Earth. It survives in environments like interstellar clouds because the density and temperatures are lower than those of Earth.


Sakai had previously studied the young star, which is located in the Taurus molecular cloud. The dense cloud is about 450 light-years from the sun, making it the closest large star-forming region to Earth. Her team had previously found rich carbon-chain molecules, and was eager to use ALMA to explore their origin and fate. The rotation that helped birth the young star continues after its formation. Gravity pulls the gas toward the star, but distance limits its reach. At the centrifugal barrier, the force of rotation outweighs the force of gravity, and the star can longer fall inward.


Gas containing cyclic-C3H2 piles up at the outer edge of the barrier, increasing the density. Temperatures of the jammed up gas spike suddenly from minus 243 degrees Celsius (minus 405 degrees Fahrenheit) to temperatures of minus 213 C (minus 351 F) or higher. The heat increase allowed the particles of SO to jump directly from the solid to gas phase in a process known as sublimation. The complex chemicals only exist outside of the barrier; inside, both would be frozen out on dust grains, causing their spectral lines to disappear and marking the boundary between the disk and the envelope.

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Tiny single-chip device to provide real-time ultrasonic 3D images from inside the heart and blood vessels

Tiny single-chip device to provide real-time ultrasonic 3D images from inside the heart and blood vessels | Amazing Science | Scoop.it

Georgia Institute of Technology researchers have developed the technology for a catheter-based device that would provide forward-looking, real-time, three-dimensional imaging from inside the heart, coronary arteries and peripheral blood vessels. With its volumetric imaging, the new device could better guide surgeons working in the heart, and potentially allow more of patients’ clogged arteries to be cleared without major surgery.


The device integrates ultrasound transducers with processing electronics on a single 1.4 millimeter  CMOS silicon chip. On-chip processing of signals allows data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, permitting it to easily travel through circuitous blood vessels. The forward-looking images produced by the device would provide significantly more information than existing cross-sectional ultrasound.


“Our device will allow doctors to see the whole volume that is in front of them within a blood vessel,” said F. Levent Degertekin, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels.”


“If you’re a doctor, you want to see what is going on inside the arteries and inside the heart, but most of the devices being used for this today provide only cross-sectional images,” Degertekin explained. “If you have an artery that is totally blocked, for example, you need to see the front, back and sidewalls altogether. That kind of information is basically not available at this time.”


The single chip device combines capacitive micromachined ultrasonic transducer (CMUT) arrays with front-end CMOS electronics technology to provide three-dimensional intravascular ultrasound (IVUS) and intracardiac echography (ICE) images.


Researchers have developed and tested a prototype able to provide image data at 60 frames per second. The researchers expect to conduct animal trials to demonstrate the device’s potential applications. They ultimately expect to license the technology to an established medical diagnostic firm to conduct the clinical trials necessary to obtain FDA approval.


For the future, Degertekin hopes to develop a version of the device that could guide interventions in the heart under magnetic resonance imaging (MRI). Other plans include further reducing the size of the device to place it on a 400-micron diameter guide wire.


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Global warming makes Arctic Ocean surfaces darker, Scripps team determines how much the planet’s albedo diminished

Global warming makes Arctic Ocean surfaces darker, Scripps team determines how much the planet’s albedo diminished | Amazing Science | Scoop.it

The retreat of sea ice in the Arctic Ocean is diminishing Earth’s albedo, or reflectivity, by an amount considerably larger than previously estimated, according to researchers at Scripps Institution of Oceanography, UC San Diego.


As the sea ice melts, its white reflective surface is replaced by a relatively dark ocean surface. This diminishes the amount of sunlight being reflected back to space, causing the Earth to absorb an increasing amount of solar energy.


The Arctic has warmed by 2° C (3.6° F) since the 1970s. The summer minimum Arctic sea ice extent has decreased by 40 percent during the same time period. These factors have decreased the region’s albedo.


Scripps graduate student Kristina Pistone and climate scientists Ian Eisenman and Veerabhadran Ramanathan used satellite measurements to calculate changes in the albedo of the Arctic region associated with the changing sea ice cover. Albedo is measured as a percentage. A perfectly black surface has an albedo of zero percent and a perfectly white surface has an albedo of 100 percent. The albedo of fresh snow is typically between 80 and 90 percent whereas the albedo of the ocean surface is less than 20 percent. Clouds and other factors also influence the albedo of the Earth.


The researchers calculated that the albedo of the Arctic region fell from 52 percent to 48 percent between 1979 and 2011.  


 “It’s fairly intuitive to expect that replacing white, reflective sea ice with a dark ocean surface would increase the amount of solar heating,” said Kristina Pistone. “We used actual satellite measurements of both albedo and sea ice in the region to verify this and to quantify how much extra heat the region has absorbed due to the ice loss.  It was quite encouraging to see how well the two datasets – which come from two independent satellite instruments – agreed with each other.”


The National Science Foundation-funded study appears in the journal Proceedings of the National Academy of Sciences 45 years after atmospheric scientists Mikhail Budyko and William Sellers hypothesized that the Arctic would amplify global warming as sea ice melted.

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'Extremely Red' Brown Dwarf Discovered With Water, Methane and Ammonia in Atmosphere

'Extremely Red' Brown Dwarf Discovered With Water, Methane and Ammonia in Atmosphere | Amazing Science | Scoop.it
European astronomers led by Dr Federico Marocco from the University of Hertfordshire have discovered a brown dwarf with unusually red skies.


Brown dwarfs are too big to be considered as planets; yet they do not have sufficient material to fuse hydrogen in their cores to fully develop into stars. Sometimes described as failed stars, they are midway in mass between stars, like our Sun, and giant planets, like Jupiter and Saturn.


Using ESO’s Very Large Telescope in Chile and an innovative data analysis technique, Dr Marocco’s team detected a very thick layer of clouds in the upper atmosphere the brown dwarf ULAS J222711-004547. “These are not the type of clouds that we are used to seeing on Earth. The thick clouds on this particular brown dwarf are mostly made of mineral dust, like enstatite and corundum. Not only have we been able to infer their presence, but we have also been able to estimate the size of the dust grains in the clouds,” Dr Marocco said.


The giant planets of the Solar System, like Jupiter and Saturn, show various cloud layers including ammonia and hydrogen sulfide as well as water vapor. The atmosphere observed in ULAS J222711-004547 is hotter – with water vapor, methane and probably some ammonia but, unusually, it is dominated by clay-sized mineral particles. Getting a good understanding of how such an extreme atmosphere works will help us to better understand the range of atmospheres that can exist.


“Being one of the reddest brown dwarfs ever observed, ULAS J222711-004547 makes an ideal target for multiple observations to understand how the weather is in such an extreme atmosphere,” said Dr Avril Day-Jones from the University of Hertfordshire, who is a co-author of the paper published in the Monthly Notices of the Royal Astronomical Society(arXiv.org).

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Celest Ybarra's curator insight, March 29, 2014 9:07 PM

Title: 'Extremely Red' Brown Dwarf Discovered With Water, Methane and Ammonia in Atmosphere

Author: Science News

Main Idea: European astronomers discovered a brown dwarf with unusually red skies.

Summary:

1) The atmosphere observed is hotter – with water vapor, methane and some ammonia but, it is dominated by clay-sized mineral particles

2) Brown dwarfs are too big to be considered as planets; yet they do not have sufficient material to fuse hydrogen in their cores to fully develop into stars.

3) Being one of the reddest brown dwarfs ever observed, it makes an ideal target for multiple observations to understand how the weather is in such an extreme atmosphere

Opinion: No, it was based off of a discovery

Question: Why is it called a dwarf?

Is this article important to science?: Yes, because it can help us better understand the range of atmospheres that can exist.

Source: http://www.sci-news.com/astronomy/science-red-brown-dwarf-01770.html

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Is vibration energy the secret to self-powered electronics in the near future?

Is vibration energy the secret to self-powered electronics in the near future? | Amazing Science | Scoop.it

A multi-university team of engineers has developed what could be a promising solution for charging smartphone batteries on the go — without the need for an electrical cord.


Incorporated directly into a cell phone housing, the team's nanogenerator could harvest and convert vibration energy from a surface, such as the passenger seat of a moving vehicle, into power for the phone. "We believe this development could be a new solution for creating self-charged personal electronics," says Xudong Wang, an assistant professor of materials science and engineering at the University of Wisconsin-Madison.


The nanogenerator takes advantage of a common piezoelectric polymer material called polyvinylidene fluoride, or PVDF. Piezoelectric materials can generate electricity from a mechanical force; conversely, they also can generate a mechanical strain from an applied electrical field.


Rather than relying on a strain or an electrical field, the researchers incorporated zinc oxide nanoparticles into a PVDF thin film to trigger formation of the piezoelectric phase that enables it to harvest vibration energy. Then, they etched the nanoparticles off the film; the resulting interconnected pores — called "mesopores" because of their size — cause the otherwise stiff material to behave somewhat like a sponge.


That sponge-like material is key to harvesting vibration energy. "The softer the material, the more sensitive it is to small vibrations," says Wang.


The nanogenerator itself includes thin electrode sheets on the front and back of the mesoporous polymer film, and the researchers can attach this soft, flexible film seamlessly to flat, rough or curvy surfaces, including human skin. In the case of a cell phone, it uses the phone's own weight to enhance its displacement and amplify its electrical output.

The nanogenerator could become an integrated part of an electronic device — for example, as its back panel or housing — and automatically harvest energy from ambient vibrations to power the device directly.

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MRI study shows, dog brains respond to human voice the same way humans do

MRI study shows, dog brains respond to human voice the same way humans do | Amazing Science | Scoop.it

A voice gives you a lot of information in just a few seconds. How do our brains make sense of this rich vocal stream, and so quickly? In 2000, scientists scanned people’s brains and discovered a piece of neural real estate that’s dedicated to the task: a spot above the ear that responds to vocal sounds more strongly than other types of sounds.


This result was intriguing partly because the neuroscience world was buzzing about the specificity of other brain areas, notes Pascal Belin, a neuroscientist at the University of Glasgow and the lead author of the 2000 voice study. Just a few years earlier, another group had shown that a region in the visual cortex, the fusiform face area, is tuned to faces. These studies posed obvious evolutionary questions, Belin says. “These voice regions respond to speech and non-speech. So, are they uniquely human, or not?”


That was answered in 2008, when another lab reported that macaque monkeys have a similar voice-sensitive region in their brains. The area responded more to the voices of other macaques than to vocalizations of other species or non-voice sounds. “With that paper, it became clear: these regions didn’t just appear with humans,” Belin says. “It’s evolutionarily much older.”


You can imagine how interpreting the voices of other members of your species would be evolutionarily advantageous, whether for discerning a rival’s fury or a lover’s desire. That monkey paper suggested that voice-sensitive brain regions existed in the last common ancestor of humans and macaques, which roamed the earth some 30 million years ago.

A brain-scanning study published today in Current Biology reports similar voice regions in the dog brain. One region responds selectively to dog vocalizations, while a nearby area responds to the emotional cues of a voice, regardless of whether the voice came from a dog or from a human. Researchers don’t agree on the evolutionary implications of these results (more on that later). Still, the study may shed light on why dogs and people get on so well.


“Dogs use very similar brain mechanisms to process social and emotional information as humans do,” says Attila Andics, a researcher in the MTA-ELTE Comparative Ethology Research Group in Budapest, who led the new study. “This probably helps the dogs tune in to the feelings of their owners, and also probably helps humans tune in to the feelings of their dog.”

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Prions Are Key to Preserving Long-Term Memories

Prions Are Key to Preserving Long-Term Memories | Amazing Science | Scoop.it

The famed protein chain reaction that made mad cow disease a terror may be involved in helping to ensure that our recollections don't fade.


Prions are proteins with two unusual properties: First, they can switch between two possible shapes, one that is stable on its own and an alternate conformation that can form chains. Second, the chain-forming version has to be able to trigger others to change shape and join the chain. Say that in the normal version the protein is folded so that one portion of the protein structure—call it "tab A"—fits into its own "slot B." In the alternate form, though, tab A is available to fit into its neighbor's slot B. That means the neighbor can do the same thing to the next protein to come along, forming a chain or clump that can grow indefinitely.


For a brain cell, keeping a memory around is a lot of work. A variety of proteins need to be continually manufactured at the synapse, the small gap that interfaces one cell to another. But whereas a cell may have a multitude of synapses, the protein synthesis that grows and maintains the connection only occurs at specific ones that have been activated. Work in the sea slug Aplysia (a favorite of neuroscientists because of its large cells) showed that a protein called CPEB, for cytoplasmic polyadenylation element binding, is necessary to keep a synapse activated. CPEB acts as a prion.


Once the prion's chain reaction gets started it's self-perpetuating, and thus the synapse can be maintained after the initial trigger is gone—perhaps for a lifetime. But that still doesn't explain how the first prion is triggered or why it only happens in certain synapses and not others.


An answer comes from Si's work on fruit flies, published February 11 in PLoS Biology. Sex—and, in particular, male courtship behavior—is an ideal realm in which to test memory: If a female is unreceptive, the male will remember this and stop trying to court her. Earlier, Si’s team showed that if the fly's version of CPEB, called Orb2, is mutated so that it cannot act as a prion, the insect briefly remembers that the female is unreceptive but that memory fades over the course of a few days.


Now, Si's team has figured out how the cell turns on the machinery responsible for the persistence of memory—and how the memory can be stabilized at just the right time and in the right place.


Before the memory is formed a fly's neuron is full of a version of the prion called Orb2B. Although this version can switch shapes to form prions' characteristic clumps, it can't get started without the related protein Orb2A. In this week's paper Si and colleagues untangled the multipartnered dance that controls Orb2A's role. First, a protein called TOB binds to Orb2A, allowing it to persist intact in the cell. (Normally, it would be broken down within a few hours.) Once stabilized it needs to have a phosphate tag attached, and this is done by another protein called Lim kinase.


Crucially, Lim kinase is only activated when the cell receives an electrical impulse—and only targeted at that synapse, not any other synaptic connections the cell might also be making. That means that the prion chain reaction is turned on in the specific time and place it's needed. This, researchers say, means the cell has a mechanism to stabilize some synapses but not others—potentially explaining why some of our memories fade, whereas others last a lifetime.


Although work so far on these proteins has been in yeast, sea slugs, flies and mice, the human CPEB may operate in the same way to preserve memories. The next steps, both researchers agree, are to develop better techniques to see where in the brain prions are activated, and to dig into more questions about how the prion process is regulated. One burning question: When we forget, does that mean that the prion's chain reaction has been halted?

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Eli Levine's curator insight, February 20, 2014 3:35 PM

They may try to make us forget, and, indeed, they may actually succeed.

 

However, science works both ways, for positive uses and for negative as well.

 

Memory loss may be helpful to some, while memory retention is good for all.

Way cool science.

 

Hope it doesn't effect us negatively in some way.

 

Think about it. 

Nacho Vega's curator insight, February 21, 2014 3:20 PM

"For a #brain cell, keeping a #memory around is a lot of work"

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Circle of Life: The Beautiful New Way to Visualize Biological Data

Circle of Life: The Beautiful New Way to Visualize Biological Data | Amazing Science | Scoop.it

Via Claudia Mihai
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Eli Levine's curator insight, February 20, 2014 12:24 PM

Way cool.

 

This just emphasizes the fact that we're all of one basic, biological species origin and not of a kind of "Creation orchard" as Mr. Ken Ham put it in his debate with Bill Nye.

 

"We are one, and one is all." - Gorillaz.

 

Think about it.

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Steve Perlman's Amazing Wireless Machine Is Finally Here

Steve Perlman's Amazing Wireless Machine Is Finally Here | Amazing Science | Scoop.it

Entrepreneur Steve Perlman unveils a new version of his wireless technology, which could give each mobile device its own super-fast connection.


Steve Perlman is ready to give you a personal cell phone signal that follows you from place to place, a signal that’s about 1,000 times faster than what you have today because you needn’t share it with anyone else.

Perlman — the iconic Silicon Valley inventor best known for selling his web TV company to Microsoft for half a billion dollars — started work on this new-age cellular technology a decade ago, and on Wednesday morning, he’ll give the first public demonstration at Columbia University in New York, his alma mater.Previously known as DIDO, the technology is now called pCell — short for “personal cell” — and judging from the demo Perlman gave us at his lab in San Francisco last week, it works as advertised, streaming video and other data to phones with a speed and a smoothness you’re unlikely to achieve over current cell networks.


“It’s a complete rewrite of the wireless rulebook,” says Perlman, who also helped Apple create QuickTime, the technology that brought video to the Macintosh. “Since the invention of wireless, people have moved around the coverage area. Now, the coverage area follows you.”


“That will shock people,” Perlman said in an interview. “It means we have hundreds of millions of devices out there that are ready to go.”


Under Perlman’s pCell system, interference from the cells is not an issue. Instead of blasting out a dumb signal across a given area, Perlman and his team of researchers have developed a smart transmission system. Their networking equipment locates a device like a smartphone and uses complex mathematical operations to create a unique signal—hence the personal cell idea—just for that device. The upshot of this is that you can place the pCell transmitters anywhere and not worry about their signals bleeding into each other. And instead of sharing a signal, each person gets to tap into close to the full capacity of the transmitter. “We believe this is the largest increase in capacity in the history of wireless technology,” says Perlman. “It’s like the wireless equivalent of fiber-optic cables.”


Artemis Networks is the company Perlman has formed to sell this technology. It’s in the process of putting pCell transmitters on about 350 rooftops in San Francisco, and Perlman is looking to work with a telco or technology company like Google(GOOG) or Microsoft (MSFT) to get a commercial service running in the fourth quarter. “We’ll do San Francisco first and then do New York, Chicago, Dallas, and other congested cities,” says Perlman.


To work properly, a company backing the pCell technology would need to build out a large data center in addition to deploying the transmitters. It’s in the data center where servers constantly crunch away on the algorithms that form the unique wireless stream aimed at each device. As people move about, the servers must keep recalculating and processing a new stream. Perlman expects that a single data center could satisfy the needs of a city like San Francisco.


Perlman has spent about 10 years working on this technology with a handful of employees. I paid a recent visit to their San Francisco laboratory and saw the technology working firsthand. Perlman had put a few of the transmitters up near the ceiling and was able to direct a wireless beam right at a device in my hand. Despite such demonstrations, Perlman has been unable to tempt venture capitalists with the technology. “They invariably bring in experts who say it doesn’t really work,” he says. “I am showing them a demo, but they remain convinced that it’s something else.”

Perlman, who made millions selling WebTV to Microsoft, has funded all of this himself, and he declines to reveal the exact amount spent so far. He will show off the pCell technology at Columbia University on Wednesday during a midday lecture.


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Casper Pieters's comment, February 21, 2014 4:39 PM
by the time we have the NBN we don't need it anymore... or way before
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Frozen bacteria repair their DNA at -15ºC

Frozen bacteria repair their DNA at -15ºC | Amazing Science | Scoop.it

Bacteria encased in ice can be resuscitated after thousands, perhaps even millions of years. How these hardy bugs manage to survive deep freeze is something of a mystery.


P. articus is an innocuous little bacteria that is famous for one thing: it really likes the cold. It can grow and metabolize at -10 ºC, making it one of the most psychrophilic organisms on Earth. To investigate P. articus’’s ability to repair DNA in deep freeze, Dieser and colleagues isolated viable P. articus cells from Siberian permafrost that has been frozen for 20 to 30 thousand years. In the lab, the researchers dosed their cell cultures with a large pulse of ionizing radiation- roughly equal to what P. articus might experience over 225 thousand years of field exposure. By using such an intense burst of radiation, the team hoped to induce many “double-strand breaks”, or breaks that cause small DNA fragments to separate off from P. articus’s main chromosome.They incubated the irradiated cultures at -15ºC and monitored their survival over the course of 505 days.


Rather astoundingly, the scientists found no significant difference between the survival rates of irradiated and non-irradiated bacteria over the year and a half long study. While this finding alone suggests P. articus can repair its DNA at subzero temperatures, Dieser and colleagues wanted direct evidence.  They used pulse-field electrophoresis, a technique which separates DNA fragments by size, to determine how may DNA double-strand breaks occurred after radiation exposure, and whether the DNA fragments reassembled themselves over time. Like Humpty Dumpty rebuilding himself, the scientists could literally watch P. articus reassemble its genome. On average, P. articus was able to patch thirteen double-strand DNA breaks over the course of the study-  quite close to the roughly sixteen breaks inducted by radiation.


Not only can P. articus repair its DNA at subzero temperatures, it can do so really fast. Using annual radiation exposure data collected in the field, Dieser estimates that P. articus can repair double-strand breaks 100,000 times faster than they occur. The discovery has important implications for the survival of life in extreme environments, including cold extraterrestrial environments. For instance on the surface of Mars, where radiation levels are ~400 times greater than the Siberian permafrost, P. articus can still patch DNA breaks 280 times faster than they would accrue. As scientists continue exploring the “cold limit” to essential cellular functions such as DNA repair, they will continue to refine, and perhaps expand, our understanding of the fundamental boundaries for life.


Markus Dieser, John R. Battista, & Brent C. Christner (2013). DNA Double-Strand Break Repair at −15°C Applied and Environmental Microbiology DOI: 10.1128/AEM.02845-13

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Zeolite–polymer composite adsorbs uremic toxins

Zeolite–polymer composite adsorbs uremic toxins | Amazing Science | Scoop.it

Scientists in Japan have developed a nanofiber mesh that can adsorb creatinine from blood with the hope that it can eventually be developed into a wearable blood-cleaning device for patients with kidney failure.


Kidney failure causes dangerous concentrations of waste products, such as potassium, urea and creatinine, to build-up in the body. Apart from having a kidney transplant, the next best solution for patients is dialysis. Dialysis, however, is far from ideal. It is time-consuming and relies on access to specialist equipment, clean water, electricity, dialysate, and, usually, a hospital. Often these requirements aren’t accessible in rural parts of developing countries and disaster areas.


Dialysis works according to the principles of diffusion, but Mitsuhiro Ebara and his team at the National Institute of Materials Science in Ibaraki have taken a different approach and developed a material that cleans blood by adsorption.


Zeolites are adsorbent minerals commonly used in water purification technologies. Different zeolites have different pore sizes meaning they can be used to selectively adsorb specific solutes. Ebara’s group trapped a zeolite into a composite mesh by electrospinning it with the biocompatible polymer, poly(ethylene-co-vinylalcohol) (EVOH), to prevent the zeolite from being released into the bloodstream. They then tested the ability of the composite mesh to adsorb creatinine from solution. The team had worried that the properties of EVOH would disable the adsorption properties of the zeolite, but instead they found the adsorption capacity of the mesh was 67% of the free zeolites.


The greatest challenge was precisely controlling the crystallinity of the polymer-zeolite fibers so that they were both insoluble and hydrophilic, says Ebara. ‘The fibers have to be hydrophilic so that the uremic toxin could access the embedded zeolites, but hydrophilic fibers are not stable in water.’


Ebara’s team calculated that a 16g mesh is enough to remove all the creatinine produced in one day by the human body. They are now designing a wrist-watch sized device that can be connected to the shunt that hemodialysis patients generally have inserted under their skin, as a more accessible and cheap alternative to dialysis treatment.


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Rabbit Fever: Uncovering the Secrets of Tularemia

Rabbit Fever: Uncovering the Secrets of Tularemia | Amazing Science | Scoop.it

Tularemia, aka "rabbit fever," is endemic in the northeastern United States, and is considered to be a significant risk to biosecurity -- much like anthrax or smallpox -- because it has already been weaponized in various regions of the world.


At the 58th Annual Biophysical Society Meeting, which takes place Feb. 15-19, 2014, Geoffrey K. Feld, a Postdoctoral researcher in the Physical & Life Sciences Directorate at Lawrence Livermore National Laboratory (LLNL), describes his work to uncover the secrets of the bacterium Francisella tularensis, which causes tularemia.


"Despite its importance for both public health and biodefense, F. tularensis pathogenesis isn't entirely understood, nor do we fully understand how the organism persists in the environment," explained Feld.


Previous efforts, funded by both the National Institutes of Health and LLNL, demonstrated that amoebae may serve as a potential reservoir for the bacteria in nature. "Specifically, we demonstrated that amoebae exposed to fully virulent F. tularensis rapidly form cysts -- dormant, metabolically inactive cells -- that allow the amoebae to survive unfavourable conditions," said Amy Rasley, the research team leader.


This encystment phenotype was rapidly induced by F. tularensis in the laboratory and was required for the long-term survival of the bacteria. Further exploration led to the identification of secreted F. tularensis proteins, which are responsible for induction of the rapid encystment phenotype (REP) observed in amoebae.


In the new work, Feld and colleagues characterized two of these REP proteins -- called REP24 and REP34 -- and began to describe their functions based on their three-dimensional crystal structures.


A big surprise finding was that these proteins resembled "proteases," which are proteins that cut other proteins in a specific manner. "Our preliminary data indicate that F. tularensis bacteria lacking these proteins are diminished in their ability to infect or survive in human immune cells, which indicates that these proteins may also contribute to F. tularensis virulence," Feld said.


Rasley and colleagues believe that careful characterization of these two novel F. tularensis proteins may shed light on how this organism persists in the environment and causes disease.


"Ultimately, this type of research could inform efforts to combat the disease, although there is much work to do. Currently, we don't know the protein targets in the host -- amoeba, human, etc. -- that the REP proteins act on, nor do we know the mechanism by which the proteins could help F. tularensis survive in the environment or cause disease," Feld said.

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1918 influenza pandemic probably sprang from domestic and wild birds, not from human and swine virus mixture

1918 influenza pandemic probably sprang from domestic and wild birds, not from human and swine virus mixture | Amazing Science | Scoop.it

A study published recently in Nature1 reconstructs the origins of influenza A virus and traces its evolution and flow through different animal hosts over two centuries. The virus that caused the 1918 influenza pandemic probably sprang from North American domestic and wild birds, not from the mixing of human and swine viruses.


“The methods we’ve been using for years and years, and which are crucial to figuring out the origins of gene sequences and the timing of those events, are all flawed,” says lead author Michael Worobey, an ecologist and evolutionary biologist at the University of Arizona in Tucson.


Worobey and his colleagues analysed more than 80,000 gene sequences from flu viruses isolated from humans, birds, horses, pigs and bats using a model they developed to map evolutionary relationships between viruses from different host species. The branched tree that resulted showed that the genes of the deadly 1918 pandemic virus are of avian origin.


Birds have been implicated in the deadly strain’s origins before. A 2005 genetic analysis of the 1918 pandemic virus pulled from a victim’s preserved tissue concluded that it most closely matched viruses of avian origin2. But a 2009 study3 found instead that the viral genes circulated in humans and swine for at least 2 to 15 years before the pandemic and combined to make the lethal virus.


Gavin Smith, an evolutionary biologist at Duke-NUS Graduate Medical School at the National University of Singapore, calls the current study “an important contribution to how we analyse data”. Smith, a co-author of the 2009 study, notes that it identified an avian relationship for two genes in the 1918 virus, but not for six genes, as the latest study has done.


Worobey's study is highly persuasive, says Oliver Pybus, an evolutionary biologist at the University of Oxford, UK. “It shows the evidence for a pig origin is a lot weaker, but it’s almost impossible to completely shut the door on that.”

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