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Submission + - Acid bath offers easy path to stem cells (nature.com)

Submitted by ananyo
ananyo writes: In 2006, Japanese researchers reported a technique for creating cells that have the embryonic ability to turn into almost any cell type in the mammalian body — the now-famous induced pluripotent stem (iPS) cells. In papers published this week in Nature, another Japanese team says that it has come up with a surprisingly simple method — exposure to stress, including a low pH — that can make cells that are even more malleable than iPS cells, and do it faster and more efficiently.
The work so far has focused on mouse white blood cells but the group are now trying to make the method work with cells adult humans. If they're succesful, that would dramatically speed up the process of creating stem cells for potential clinical applications.

Submission + - Stephen Hawking claims "there are no black holes" (nature.com)

Submitted by ananyo
ananyo writes: Stephen Hawking has proposed a new solution to the black-hole firewall paradox, which has been vexing physicists for almost two years, after its discovery by theoretical physicists Joe Polchinski at the Kavli Institute for Theoretical Physics in Santa Barbara, California, and colleagues. The paradox troubles physicists because if the firewall scenario is correct, Einstein’s general theory of relativity is flouted. But the classical theory black hole cannot be reconciled to the quantum mechanical prediction that energy and information can escape from a black hole.
Now Hawking has proposed a tantalizingly simple solution to the paradox which allows both quantum mechanics and general relativity to remain intact--black holes simply do not have an event horizon to catch fire. The key to his claim is that quantum effects around the black hole cause spacetime to fluctuate too wildly for a sharp boundary surface to exist. As Hawking writes in his paper, "The absence of event horizons mean that there are no black holes — in the sense of regimes from which light can't escape to infinity."

Submission + - Why 'irrational' choices can be rational (nature.com)

Submitted by ananyo
ananyo writes: Organisms, including humans, are often assumed to be hard-wired by evolution to try to make optimal decisions, to the best of their knowledge. Ranking choices consistently — for example, in selecting food sources — would seem to be one aspect of such rationality. If A is preferred over B, and B over C, then surely A should be selected when the options are just A and C? This seemingly logical ordering of preferences is called transitivity.
Furthermore, if A is preferred when both B and C are available, then A should ‘rationally’ remain the first choice when only A and B are at hand — a principle called the independence of irrelevant alternatives (IIA).
But sometimes animals do not display such logic. For example, honeybees (Apis mellifera) and gray jays (Perisoreus canadensis) have been seen to violate IIA, and so have hummingbirds (Selasphorus rufus).
Researchers have now used a theoretical model to show that, in fact, violations of transitivity can sometimes be the best choice for the given situation, and therefore rational. The key is that the various choices might appear or disappear in the future. Then the decision becomes more complicated than a simple, fixed ranking of preferences. So while these choices look irrational, they aren’t necessarily.

Submission + - Physicists explain 'gravity-defying' chain trick (nature.com)

Submitted by ananyo
ananyo writes: Leaping up out of a jar in an arc before falling to the floor, the fountain-like motion of a chain of beads has puzzled millions around the world with its apparently gravity-defying behaviour. Now physicists think they have an explanation.
British science presenter Steve Mould, who made the experiment famous, explained the phenomenon as simply one of inertia: the falling chain has downward momentum, causing an upward momentum in beads leaving the pot. This, in turn, makes them leap before gravity can slowly reverse their momentum.
Mould’s explanation was clever, but wrong, says physicist John Biggins of the University of Cambridge, UK. The only way to account for the rise is for the chain to receive a 'kick' from the pot from which it is being pulled. This challenges not only the explanation given by Mould, but the conventional mathematics of chains, Biggins says.

Submission + - Ampere could be redefined after experiments track single electrons crossing chip (nature.com)

Submitted by ananyo
ananyo writes: Physicists have tracked electrons crossing a semiconductor chip one at a time — an experiment that should at last enable a rational definition of the ampere, the unit of electrical current.
At present, an ampere is defined as the amount of charge flowing per second through two infinitely long wires one metre apart, such that the wires attract each other with a force of 2×107 newtons per metre of length. That definition, adopted in 1948 and based on a thought experiment that can at best be approximated in the laboratory, is clumsy — almost as much of an embarrassment as the definition of the kilogram, which relies on the fluctuating mass of a 125-year-old platinum-and-iridium cylinder stored at the International Bureau of Weights and Measures in Paris.
The new approach, described in a paper posted onto the arXiv server on 19 December, would redefine the amp on the basis of e, a physical constant representing the charge of an electron.

Submission + - First recorded observation of freshwater fish preying on birds in flight (nature.com)

Submitted by ananyo
ananyo writes: The waters of the African lake seem calm and peaceful. A few migrant swallows flit near the surface. Suddenly, leaping from the water, a fish grabs one of the famously speedy birds straight out of the air.
“The whole action of jumping and catching the swallow in flight happens so incredibly quickly that after we first saw it, it took all of us a while to really fully comprehend what we had just seen,” says Nico Smit, director of the Unit for Environmental Sciences and Management at North-West University in Potchefstroom, South Africa.
After the images did sink in, he adds, “the first reaction was one of pure joy, because we realized that we were spectators to something really incredible and unique”.
  Rumours of such behaviour by the African tigerfish (Hydrocynus vittatus), which has been reported as reaching one metre in length, have circulated since the 1940s. But this is the first confirmed record of a freshwater fish preying on birds in flight, the team reports in the Journal of Fish Biology (PDF).

Submission + - Swarms of small satellites set to deliver close to real-time imagery of Earth (nature.com) 1

Submitted by ananyo
ananyo writes: A swarm of small satellites set to deliver close to real-time imagery of swathes of the planet is launching today. San Francisco-based Planet Labs, founded in 2010 by three former NASA scientists, is scheduled to launch 28 of its ‘Doves’ on 9 January. Each toaster-sized device weighs about 5 kilograms and can take images at a resolution of 3–5 metres.
Meanwhile Skybox Imaging plans to launch a swarm of 24 satellites, each weighing about 100 kilograms, which will take images of 1 metre resolution or better. Skybox launched its first satellite on 21 November (and captured the first HD video of the world from space) and plans to launch another this year, followed by the remainder between 2015 and 2017. In a first — at least for civilian satellites — Skybox’s devices will also stream short segments of near-live high-resolution video footage of the planet. So, too, will UrtheCast, a start-up based in Vancouver, Canada, whose cameras will hitch a ride on the International Space Station.
Because the swarms are still to be launched, scientists have yet to fully assess the quality of the imagery. But the satellites’ spatial resolutions of 1–5 metres are much higher than those of most scientific satellites. Landsat, NASA’s Earth-observation workhorse, for example, has a resolution of 15–100 metres depending on the spectral frequency, with 30 metres in the visible-light range.

Comment Re:Meaningless values are meaningless. (Score 1) 134

by ananyo (#45898691) Attached to: China Tops Europe In R&D Intensity

Proportion of GDP spent on research is not a 'meaningless' number. The EU spent a great deal of time trying to (unsuccessfully) urging its member states to push their total spending up to 3%. They've since realized that no single metric can adequately measure a nation's capacity to innovate in science - but this measure is still part of a basket of metrics that it's perfectly reasonable to use to examine a country's commitment to science.
To be clear - there's little evidence that spending a lot of money science will get you a Google or a Genentech, but on the other hand, a fair bit of evidence that spending nothing will make it extremely unlikely. ie science spending is necessary but not sufficient.

Submission + - China tops Europe in R&D intensity (nature.com)

Submitted by ananyo
ananyo writes: By pouring cash into science and technology faster than its economy has expanded, China has for the first time overtaken Europe on a key measure of innovation: the share of its economy devoted to research and development.
In 2012, China invested 1.98% of its gross domestic product (GDP) into R&D — just edging out the 28 member states of the European Union, which together managed 1.96%, according to the latest estimates of research intensity, to be released this month by the OECD.
The figures show that China’s research intensity has tripled since 1998, whereas Europe’s has barely increased (see graph). The numbers are dominated by business spending, reflecting China’s push in the manufacturing and information- and communication-technology industries.

Submission + - Bizarre star could host a neutron star in its core (nature.com) 1

Submitted by ananyo
ananyo writes: Astronomers say that they have discovered the first example of a long-sought cosmic oddity: a bloated, dying star with a surprise in its core — an ultradense neutron star.
Such entities, known as Thorne-Zytkow objects, are theoretically possible but would alter scientists' understanding of how stars can be powered. Since Thorne-Zytkow objects were first proposed in 19751, researchers have occasionally offered up candidates, but none have been confirmed.

Submission + - World's oldest decimal multiplication table discovered (nature.com)

Submitted by ananyo
ananyo writes: From a few fragments out of a collection of 23-century-old Chinese bamboo strips, historians have pieced together what they say is the world's oldest example of a multiplication table in base 10.
Each strip is about 7 to 12 millimetres wide and half a metre long, and has a vertical line of ancient Chinese calligraphy painted on it in black ink. The bamboo pieces constitute 65 ancient texts and are thought to be among the most important artefacts from the Warring States period before the unification of China. But 21 bamboo strips contained only numbers and, on closer inspection, turned out to be a multiplication table.
As in a modern multiplication table, the entries at the intersection of each row and column in the matrix provide the results of multiplying the corresponding numbers. The table can also help users to multiply any whole or half integer between 0.5 and 99.5. The researchers suspect that officials used the multiplication table to calculate surface area of land, yields of crops and the amounts of taxes owed.

Submission + - Researchers use electroconvulsive therapy to disrupt recall of nasty events (nature.com)

Submitted by ananyo
ananyo writes: In the film Eternal Sunshine of the Spotless Mind, unhappy lovers undergo an experimental brain treatment to erase all memories of each other from their minds. No such fix exists for real-life couples, but researchers report in Nature Neuroscience that a targeted medical intervention helps to reduce specific negative memories in patients who are depressed.
The technique, called electroconvulsive (ECT) or electroshock therapy, induces seizures by passing current into the brain through electrode pads placed on the scalp. Despite its sometimes negative reputation, ECT is an effective last-resort treatment for severe depression, and is used today in combination with anaesthesia and muscle relaxants.
Marijn Kroes, a neuroscientist at Radboud University Nijmegen in the Netherlands, and his colleagues found that by strategically timing ECT bursts, they could target and disrupt patients' memory of a disturbing episode.

Submission + - Study confirms narcolepsy is an autoimmune disease (nature.com)

Submitted by ananyo
ananyo writes: As the H1N1 swine flu pandemic swept the world in 2009, China saw a spike in cases of narcolepsy — a mysterious disorder that involves sudden, uncontrollable sleepiness. Meanwhile, in Europe, around 1 in 15,000 children who were given Pandemrix — a now-defunct flu vaccine that contained fragments of the pandemic virus — also developed narcolepsy, a chronic disease.
Immunologist Elizabeth Mellins and narcolepsy researcher Emmanuel Mignot at Stanford University School of Medicine in California and their collaborators have now partly solved the mystery behind these events, while also confirming a longstanding hypothesis that narcolepsy is an autoimmune disease, in which the immune system attacks healthy cells.
Narcolepsy is mostly caused by the gradual loss of neurons that produce hypocretin, a hormone that keeps us awake. Many scientists had suspected that the immune system was responsible, but the Stanford team has found the first direct evidence: a special group of CD4+ T cells (a type of immune cell) that targets hypocretin and is found only in people with narcolepsy.

Submission + - Academics should not remain silent on hacking (nature.com)

Submitted by ananyo
ananyo writes: The Guardian's technology editor, Charles Arthur, asks in an opinion piece in Nature why researchers have remained largely silent in the wake of the revelation that the US National Institute of Standards and Technology's standard for random numbers used for cryptography had been weakened by the NSA:
"The nature of the subversions sounds abstruse: the random-number generator, the 'Dual EC DRBG' standard, had been hacked by the NSA and the UK's GCHQ so that its output would not be as random as it should have been. That might not sound like much, but if you are trying to break an encrypted message, the knowledge that it is hundreds or thousands of times weaker than advertised is a great encouragement."
Arthur attributes the silence of UK academics, at least, to pressure from GCHQ. He goes on to say:
"For those who do care, White and Matthew Green, who teaches cryptography at Johns Hopkins University in Baltimore, Maryland, have embarked on an ambitious effort to clean up the mess — one that needs help.
They have created a non-profit organization called OpenAudit.org, which aims to recruit experts to provide technical assistance for security projects in the public interest, especially open-source security software."

Comment Polynesians DIDN'T invent binary (Score 1) 170

by ananyo (#45713311) Attached to: Polynesians May Have Invented Binary Math

http://www.nature.com/news/polynesian-people-used-binary-numbers-600-years-ago-1.14380
>>Cognitive scientist Rafael Nuñez at the University of California, San Diego, points out that the idea of binary systems is actually older than Mangarevan culture. “It can be traced back to at least ancient China, around the 9th century bc”, he says, and it can be found in the I Ching, a millennia-old Chinese text that inspired Leibniz. Nuñez adds that “other ancient groups, such as the Maya, used sophisticated combinations of binary and decimal systems to keep track of time and astronomical phenomena. Thus, the cognitive advantages underlying the Mangarevan counting system may not be unique.”

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