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Human sensitivity to wetness plays a role in many aspects of daily life. Whether feeling humidity, sweat or a damp towel, we often encounter stimuli that feel wet. Though it seems simple, feeling that something is wet is quite a feat because our skin does not have receptors that sense wetness. The concept of wetness, in fact, may be more of a “perceptual illusion” that our brain evokes based on our prior experiences with stimuli that we have learned are wet.
So how would a person know if he has sat on a wet seat or walked through a puddle? Researchers at Loughborough University and Oxylane Research proposed that wetness perception is intertwined with our ability to sense cold temperature and tactile sensations such as pressure and texture. They also observed the role of A-nerve fibers — sensory nerves that carry temperature and tactile information from the skin to the brain — and the effect of reduced nerve activity on wetness perception. Lastly, they hypothesized that because hairy skin is more sensitive to thermal stimuli, it would be more perceptive to wetness than glabrous skin (e.g., palms of the hands, soles of the feet), which is more sensitive to tactile stimuli. More here Why wet feels wet: Understanding the illusion of wetness
Many of the choices we make are informed by experiences we’ve had in the past. But occasionally we’re better off abandoning those lessons and exploring a new situation unfettered by past experiences. Scientists at the Howard Hughes Medical Institute’s Janelia Research Campus have shown that the brain can temporarily disconnect information about past experience from decision-making circuits, thereby triggering random behavior.
In the study, rats playing a game for a food reward usually acted strategically, but switched to random behavior when they confronted a particularly unpredictable and hard-to-beat competitor. The animals sometimes got stuck in a random-behavior mode, but the researchers, led by Janelia lab head Alla Karpova and postdoctoral fellow Gowan Tervo, found that they could restore normal behavior by manipulating activity in a specific region of the brain. Because the behavior of animals stuck in this random mode bears some resemblance to that of patients affected by a psychological condition called learned helplessness, the findings may help explain that condition and suggest strategies for treating it. Karpova, Tervo and their colleagues published their findings in the September 25, 2012, issue of the journal Cell.
The brain excels at integrating information from past experiences to guide decision-making in new situations. But in certain circumstances, random behavior may be preferable. An animal might have the best chance of avoiding a predator if it moves unpredictably, for example. And in a new environment, unrestricted exploration might make more sense than relying on an internal model developed elsewhere. So scientists have long speculated that the brain may have a way to switch off the influence of past experiences so that behavior can proceed randomly, Karpova says. But others disagreed. “They argue that it’s inefficient, and that it would be at odds with what some people call one of the most central operating principles of the brain – to use our past experience and knowledge to optimize behavioral choices,” she notes. Via Strategic or random? In the face of uncertainty, the brain chooses randomness as the best strategy.
Here is a great insight into the spread of Ebola by Deskarati favourite Prof. Hans Rosling.
When you think about it, passwords are a pretty terrible solution to online security. They’re difficult to remember – especially now that it’s recommended that you have a different, extremely complex one for every website you log into – and frighteningly easy to hack, so we obviously need a better way to keep our data under wraps.
So a US-based design company called Bionym partnered with identification technology experts, Brivo Labs, to create the Nymi bracelet. This wearable device uses your unique cardiac rhythm, or ‘heartwave pattern’, to act like a form of identification so only you can unlock your online accounts. Right now, the bracelet only works with computers, but the team is now working on getting it to work with physical doors, in an effort to do away with keys and swipe cards forever.
“Your heartbeat is consistent, which makes it different from an iris or fingerprint which needs to be scanned. This makes it a frictionless form of identification, since you don’t need to stop to be verified,” Lee Odess, general manager at Brivo Labs, told Elizabeth Segran from Fast Company. “It’s not just about a signing in. It’s about bringing attributes about yourself so that you can have a curated experience.” Via This wearable device replaces passwords using the unique patterns of your heart beats.
The ability to make measurements of the biomolecular interactions that occur inside living cells is essential for understanding complex biological processes. But probing the inside of living cells without damaging them is a challenge. The cell membrane shields electrical fields, prohibiting the use of electrophoresis, a technique that is commonly used to analyze biological samples in a variety of areas outside living cells.
Now in a new paper, researchers have demonstrated for the first time that thermophoresis—the movement of molecules due to a temperature gradient rather than an electric field—can be used to measure the movement of DNA and other molecules inside living cells. The paper, by Maren R. Reichl and Dieter Braun at the Ludwig Maximilian University of Munich, is published in a recent issue of The Journal of the American Chemical Society.
“Our work shows that the measurement of thermophoresis in living cells is possible—moreover, in parallel across the cell and not at one single point,” Braun told Phys.org.
In the new technique, a temperature gradient is applied across a cell by an infrared laser. Fluorescently marked molecules inside the cell move along this temperature gradient from hotter to colder regions. A camera can record this thermophoretic movement, with every camera pixel measuring thermophoresis simultaneously and independently. The technique can be performed in the natural environment of cells in vivo. Via Scientists manipulate molecules inside living cells with temperature gradients.
Destino is an animated short film released in 2003 by The Walt Disney Company. Destino is unique in that its production originally began in 1945, 58 years before its eventual completion. The project was a collaboration between American animator Walt Disney and Spanish painter Salvador Dalí.
The music in the video is a Lulu Rouge remix of a song by Nina Simone called “Will He Come”. I consider this to be my personal reinterpretation of the animation. The original soundtrack was composed by Mexican songwriter Armando Dominguez and performed by Dora Luz.
The stethoscope revolutionised the way doctors interacted with their patients and became a symbol of the profession. Now that electronic alternatives are becoming a common sight on the wards, maybe it’s time to update our idea of what a doctor is for?
“Every medical student remembers the day when they bought their first stethoscope,” says Professor of Cardiology Petros Nihoyannopoulos. “They remember the name of the stethoscope, they remember the colour of the stethoscope – and possibly the day when their first stethoscope was stolen and replaced by another one.”
But in Hammersmith Hospital in London, where Dr Nihoyannopoulos works, the noble instrument is under threat from a little white box. Looking like a smartphone circa 2005, the handheld ultrasound scanner is connected by wire to a probe which is laid against a patient’s chest. Flip the lid of the scanner and a black and white image appears on the scanner of the patient’s heart. At the push of a button the patient’s blood flow is highlighted, if all is well, in red and blue. An abnormal flow is painted in lurid yellows and greens.
“Every single consultant and junior doctor is hooked on these devices,” says Nihoyannopoulos. “When one breaks down or goes missing, it’s a disaster – everyone is panicking. It’s like when you lose your stethoscope as a medical student.” Lots more here An electronic revolution in the doctor’s bag.
This remarkably slender green vine snake, Oxybelis fulgidus, is a colubrid from Central America and northern South America. It is mildly venomous and is shown here opening its mouth in threat display. Image: Suhaas Premkumar
A police helicopter flies past the Soyuz TMA-14M spacecraft is transported to its launch pad at Baikonur cosmodrome September 23, 2014. The Soyuz is scheduled to carry Barry Wilmore of the U.S., Elena Serova and Alexander Samokutyaev of Russia to the International Space Station on September 26. Image: REUTERS/Shamil Zhumatov
Researchers at Sandia National Laboratories’ Z machine have produced a significant output of fusion neutrons, using a method fully functioning for only little more than a year. The experimental work is described in a paper to be published in the Sept. 24 Physical Review Letters online. A theoretical PRL paper to be published on the same date helps explain why the experimental method worked. The combined work demonstrates the viability of the novel approach.
“We are committed to shaking this [fusion] tree until either we get some good apples or a branch falls down and hits us on the head,” said Sandia senior manager Dan Sinars. He expects the project, dubbed MagLIF for magnetized liner inertial fusion, will be “a key piece of Sandia’s submission for a July 2015 National Nuclear Security Administration review of the national Inertial Confinement Fusion Program.”
Inertial confinement fusion creates nanosecond bursts of neutrons, ideal for creating data to plug into supercomputer codes that test the safety, security and effectiveness of the U.S. nuclear stockpile. The method could be useful as an energy source down the road if the individual fusion pulses can be sequenced like an automobile’s cylinders firing. MagLIF uses a laser to preheat hydrogen fuel, a large magnetic field to squeeze the fuel and a separate magnetic field to keep charged atomic particles from leaving the scene.
It only took the two magnetic fields and the laser, focused on a small amount of fusible material called deuterium (hydrogen with a neutron added to its nucleus), to produce a trillion fusion neutrons (neutrons created by the fusing of atomic nuclei). Had tritium (which carries two neutrons) been included in the fuel, scientific rule-of-thumb says that 100 times more fusion neutrons would have been released. (That is, the actual release of 10 to the 12th neutrons would be upgraded, by the more reactive nature of the fuel, to 10 to the 14th neutrons.) Still, even with this larger output, to achieve break-even fusion—as much power out of the fuel as placed into it—100 times more neutrons (10 to the 16th) would have to be produced. More here Sandia magnetized fusion technique produces significant results.
A couple of great pics from the mail online‘s interview with Phil Collins today. – Deskarati
As you probably guessed, we read a lot of blogs as we look for interesting articles to recommend to you. So we decided to add a new category of ‘Recommended Blogs’ which we hope you will find interesting. Our first is by Paul Lay over at History Today, Paul is always coming up with unusual and interesting stuff. If you know of any good blogs please let us know. – Deskarati
Joseph Banks, patron of the natural sciences and a president of the Royal Society, did not approve of tattoos. As a young man on Captain Cook’s first great voyage into the Pacific, he was baffled by the sight of the illustrated peoples of Polynesia. Musing on the reasons for their tattoos, he observed in 1769 that:
“possibly superstition may have something to do with it. Nothing else in my opinion could be a sufficient cause for so apparently absurd a custom”.
Though tattoos had an aristocratic moment during the late Victorian and Edwardian periods – Jennie Churchill, Winston’s mother, had a snake etched on her wrist, which she would cover up discreetly with a diamond bracelet – they were long associated in the West with criminals and sailors. At the beginning of the 20th century around 90 per cent of men serving in the Royal Navy were tattooed, usually with symbols that marked – literally – a particular rite of passage: a turtle for having passed the Equator, an anchor for crossing the Atlantic, a dragon symbolising a posting on a China station. One could track the arc of a sailor’s service from his tattoos. Yet outside of ports and prisons the tattoo, in Britain at least, was a rare sighting.
That is not the case today. Walking down any British high street, one is as astonished as Banks would be by the ubiquity of the tattoo, to the point where unblemished skin is more an indicator of eccentricity and rebellion than an elaborately inked limb. But the people of Britannia – the Pretanni, the ‘painted ones’ – are, whether they know it or not, returning to their roots. Marc Morris, the medieval historian, pointed this passage out to me from the 12th-century chronicler, William of Malmesbury, describing the locals on the eve of the Battle of Hastings:
“The English at that time wore short garments, reaching to the mid-knee; they had their hair cropped, their beards shaven, their arms laden with gold bracelets, their skin adorned with tattooed designs. They were accustomed to eat till they became surfeited, and to drink till they were sick.”
‘Plus ça change, plus c’est la même chose’, as their conquerors might have said. Catch Paul Lay’s blog over at History Today
Black holes have long captured the public imagination and been the subject of popular culture, from Star Trek to Hollywood. They are the ultimate unknown – the blackest and most dense objects in the universe that do not even let light escape. And as if they weren’t bizarre enough to begin with, now add this to the mix: they don’t exist.
By merging two seemingly conflicting theories, Laura Mersini-Houghton, a physics professor at UNC-Chapel Hill in the College of Arts and Sciences, has proven, mathematically, that black holes can never come into being in the first place. The work not only forces scientists to reimagine the fabric of space-time, but also rethink the origins of the universe. “I’m still not over the shock,” said Mersini-Houghton. “We’ve been studying this problem for a more than 50 years and this solution gives us a lot to think about.”…
…In 1974, Stephen Hawking used quantum mechanics to show that black holes emit radiation. Since then, scientists have detected fingerprints in the cosmos that are consistent with this radiation, identifying an ever-increasing list of the universe’s black holes. But now Mersini-Houghton describes an entirely new scenario. She and Hawking both agree that as a star collapses under its own gravity, it produces Hawking radiation. However, in her new work, Mersini-Houghton shows that by giving off this radiation, the star also sheds mass. So much so that as it shrinks it no longer has the density to become a black hole. Before a black hole can form, the dying star swells one last time and then explodes. A singularity never forms and neither does an event horizon. The take home message of her work is clear: there is no such thing as a black hole. Continue reading
The date has been fixed for Europe’s daring attempt to land on a comet: Wednesday 12 November. It will see the Rosetta satellite, which is currently orbiting the huge “ice mountain” known as 67P, drop a small robot from a height of 20km. If all goes well, the lander will free-fall towards the comet, making contact with the surface somewhere in a 1km-wide zone at roughly 15:35 GMT.
The European Space Agency (Esa) says the challenges ahead are immense. Imagine pushing a washing machine out the back of an airliner at twice cruising altitude and expecting it to hit Regent’s Park in London – all while the ground is moving underneath. Although not really analogous for many reasons, this scenario does give a sense of the difficulties involved. The chances of failure are high. Via Rosetta: Date fixed for historic comet landing attempt.
Astronomers know how stellar-mass black holes form: A massive star collapses under its own gravity. But such a process would seem unable to explain how much larger black holes arise, because they can only gobble material up to a rate known as the Eddington limit, and the universe isn’t old enough for them to have grown from stellar mass to supermassive, said Cole Miller, an astronomer also at the University of Maryland.
“If you feed matter to the black hole too fast, it produces so much radiation that it blows away the matter that’s trying to ,” Miller told Live Science.
How, then, might supermassive black holes form? Some theories suggest these strange behemoths grew from intermediate-mass black holes — which act as “seeds” — that formed in the early stages of the universe from the collapse of giant clouds of gas. Others say these black hole giants started out as stellar-mass black holes that somehow gobbled up material at a rate much faster than the typical limit. Miller has theorized that maybe a dense cluster of stars merged in the early universe, “colliding with each other and sticking together like wet clay,” producing a black hole that gathers mass at a rate exceeding the normal limit. “If you can evade that limit, you might be able to build bigger black holes,” he said. Continue reading
The very neat defensive pose of a southern three banded armadillo. Via Facebook.
This underwater video is impossibly surreal but the makers of the video, Francisco and Armando del Rosario and Armiche Ramos, say that no computer special effects were used in the video, just some camera tricks to make it look like the ocean world can be sideways and water can be walked upside down on. Via Sploid
Sandro Miller (1958) is an American portrait photographer (working professionally as “Sandro”) known for his expressive images, and his close work with John Malkovich and the other ensemble members of Chicago’s Steppenwolf Theatre Company. At the Cannes Lions International Festival of Creativity in July 2011, Sandro was acknowledged with a Saatchi & Saatchi Best New Director Award for his short video “Butterflies” featuring John Malkovich. For the past five years, in juried competition within the industry, Sandro has been voted one of the top 200 advertising photographers in the world.
In 2001 Sandro was invited by the Cuban government to photograph their Olympic athletes. This project was the first US/Cuban collaboration since the trade embargo was imposed in 1960. Sandro shoots all the promotional photography for Dance for Life, the Midwest’s largest performance-based AIDS fundraiser. He also sits on the board of directors for the Museum of Contemporary Photography and is a member of the Chicago Arts Club.
Here we have picked three of our favourites including Dennis Hopper, Al Pacino and one of Sando’s most photographed, John Malkovich. You can find Sandro’s work here – Sandrofilm – Deskarati