[CENTRAAL] Wetenschap & Technologie in het Nieuws 3

WORLD FIRST: MASSIVE COSMIC RADIO BURST DETECTED IN REAL TIME

For the first time, scientists in Australia have detected a gigantic burst of radio waves from outside our galaxy in real time. Called blitzars, these bursts generate as much energy as the Sun does in a day, but they do it in mere milliseconds.

BEC CREW 20 JAN 2015

Astronomers manning the Parkes radio telescope in New South Wales have detected the first real-time burst of radio waves from outside our Milky Way galaxy. Unlike similar cosmic events, such as gamma ray bursts or supernovae, which emit energy across several wavelengths, all the energy given off by blitzars is contained within the single band of the radio light spectrum.

The source of these ‘blitzars’ has so far remained a mystery, but finds like this could help scientists figure out what’s causing them.

Blitzars were first discovered by researchers at Swinburne University of Technology in Melbourne using the Parkes telescope. Also known as ‘fast radio bursts’ (FRB’s), seven more were discovered - six more using the Parkes telescope, and one using Arecibo telescope in Puerto Rico - but each of these were found up to several years, after the actual event. That’s what makes this latest discovery so special - the Swinburne researchers were able to detect the blitzar as soon as the resulting radiation reached Earth.

“These bursts were generally discovered weeks, months or even more than a decade after they happened,” PhD student Emily Petroff, who witnessed the event, said in a university press release. “We are the first to catch one in real time.”

Petroff has gotten to know these bursts of radio waves so well, that once she was confident she’d see a ‘live’ one, she let astronomers around the world know so they could make follow-up observations as soon as it was detected. So the aftermath was watched by scientists manning 12 telescopes in Australia, California, the Canary Islands, Chile, Germany, Hawaii, and India, plus the Swift Gamma Ray Burst Explorer in space, who captured it at wavelengths ranging from radio to X-ray.

Michael Slezek reports at New Scientist that the fact that, several hours after the explosion, no one saw an afterglow, makes it less likely that long gamma-ray bursts or supernovae were the source.

"Nobody knows what to make of it,” astronomer Keith Bannister from Australia's national science agency, the CSIRO, told Slezek. "All the ideas are very exotic so ruling them out is all you can do at the moment."

“We can rule out some ideas because no counterparts were seen in the optical, infrared, ultraviolet or X-ray,” Head of Astrophysics at CSIRO, Simon Johnston, added in the press release. "However, the neat idea that we are seeing a neutron star imploding into a black hole remains a possibility.”

So the team is thinking that perhaps an oversized neutron star - which has the strongest magnetic field of anything in the known universe - collapsed. Normally, this would see it be consumed by a black hole, but perhaps it was spinning so fast, says Slezek, that relativity made it appear light enough to avoid that particular fate. “Other possibilities include a flare from a magnetar, a type of neutron star with an extremely strong magnetic field,” he says.

Publishing their findings in The Monthly Proceedings of the Royal Astronomical Society, the team says they’ve calculated the blitzar to be up to 5.5 billion light-years away from Earth. “This means it could have given off as much energy in a few milliseconds as the Sun does in a day,” she said in the press release.

Now that they’ve managed it once, Petroff thinks it’s only a matter of time before they detect another ‘real time' blitzar. “We’ve set the trap. Now we just have to wait for another burst to fall into it.”

http://www.sciencealert.c(...)etected-in-real-time

Ook op nu.nl

http://www.nu.nl/wetensch(...)ngen-telescoop-.html

GM MICROBES CREATED THAT CAN'T ESCAPE THE LAB

Engineered bacteria kept in check with a designer diet.



Synthetic biologists hope to treat disease in the gut by making Lactobacillus bacteria (pictured) that are dependent on an artificial amino acid.

Critics of genetic engineering have long worried about the risk of modified organisms escaping into the environment. A biological-containment strategy described this week in Nature1, 2 has the potential to put some of those fears to rest and to pave the way for greater use of engineered organisms in areas such as agriculture, medicine and environmental clean-up.

Two US teams have produced genetically modified (GM) bacteria that depend on a protein building block — an amino acid — that does not occur in nature. The bacteria thrive in the laboratory, growing robustly as long as the unnatural amino acid is included in their diet. But several experiments involving 100 billion or more cells and lasting up to 20 days did not reveal a single microbe capable of surviving in the absence of the artificial supplement.

“Our strains, to the extent that we can test them, won’t escape,” says Dan Mandell, a synthetic biologist at Harvard Medical School in Boston, Massachusetts, and an author on one of the two studies describing the strategy.

The microbes also do not swap their engineered DNA with natural counterparts because they no longer speak life’s shared biochemical language. “Establishing safety and security from the get-go will really enable broad and open use of engineered organisms,” says Farren Isaacs, a synthetic biologist at Yale University in New Haven, Connecticut, who led the other study.

Biocontainment could provide added safety in the biological production of drugs or fuels, where microbes can be kept separate from their surroundings. But the modified bacteria could also permit controlled release into the human body or the environment. “Containment might no longer be of the physical kind,” says Tom Ellis, a synthetic biologist at Imperial College London who was not involved in the research.

The new technique originated in the laboratory of George Church, a geneticist at Harvard Medical School. Two years ago, Church and his team (which included Isaacs) reported the synthesis of a strain of Escherichia coli that had a reprogrammed genetic code3. Instead of recognizing a particular DNA triplet known as the amber stop codon as an order to terminate protein synthesis, the recoded bacterium read the same instruction as a directive to incorporate a new kind of amino acid into its proteins.

Church and Isaacs have independently made this engineered microbe reliant on unnatural amino acids. The Isaacs team used genomic sequencing to identify sites in essential bacterial proteins where the microbes could incorporate synthetic amino acids without affecting overall function, whereas Church’s group started with the protein structures and added elements to help integrate and accommodate the artificial amino acids.

“This is really the culmination of a decade of work,” says Church.

These organisms are also more resistant to viruses than their natural counter­parts because of the mismatch between the genetic code of the virus and that of its host3. Looking ahead, Church and his team are working to co-opt seven different codons, instead of just one. “That would be more than enough to be resistant to all viruses and to create a lot of opportunity for safety,” Church says.

Isaacs has also developed a different safeguarding system, in which E. coli can grow only in environments containing synthetic chemicals needed for gene expression. He described the work this month in Nucleic Acids Research4. Another research team led by Jef Boeke at the New York University Langone Medical Center and Patrick Yizhi Cai at the University of Edinburgh, UK, has been working on a similar strategy in yeast. Commonly used in industry and biotechnology, yeast has its genetic mater­ial packaged in chromosomes similarly to animals and plants rather than bacteria.

“That’s a strategy that is going to be more easily adaptable to other organisms beyond E. coli,” says Isaacs. His team is now engineering a bacterium that is dependent on synthetic chemicals as well as on artificial protein building blocks. “I think ultimate solutions for robust biocontainment will involve multiple approaches that are deployed at the same time in a single organism,” he says.

Such a beast will present a real challenge for regulators, says Todd Kuiken, senior research associate for the Science and Technology Innovation Program at the Woodrow Wilson International Center for Scholars in Washington DC. “What we’re now starting to talk about is a really, completely synthetic organism,” Kuiken says. “How do you evaluate that once you put it out into the field?”

http://www.nature.com/new(...)cape-the-lab-1.16758

SCIENTISTS MAY HAVE FOUND THE PART OF THE BRAIN THAT ENABLES LUCID DREAMING

People who are aware, and often in control, during their dreams have one thing in common, researchers have found.

FIONA MACDONALD 26 JAN 2015

Do a quick Google search for lucid dreaming - the phenomenon where someone is aware during their dreams - and you'll quickly be overwhelmed with tips and techniques for unlocking the ability.

Despite lucid dreaming being relatively rare in most people, knowing when you're dreaming and potentially even being able to change the course of your dreams is clearly desirable to a lot of people.

Now scientists from Germany believe they may have found the neurological key to the ability. After scanning the brains of regular dreamers and those who are frequently lucid, they've found that the region of the brain that enables self reflection is larger among lucid dreamers.

"Our results indicate that self-reflection in everyday life is more pronounced in persons who can easily control their dreams," said Elisa Filevich, a research at the Centre for Lifespan Psychology at the Max Planck Institute for Human Development, who was one of the leaders of the research, in a press release.

Although research has previously shown that people who lucid dream appear to have more pronounced awareness of their own thought processes, known as metacognition, this is one of the first studies to explore the link between the two at a neural level.

To do this, the team asked volunteers to complete a questionnaire on their lucid dreaming ability, and then split them into two groups depending on whether they were highly lucid, or never or rarely lucid during dreams.

The team then performed structural and functional MRI scans on the two different groups to compare the volume of different regions of their brains.

What they found was that participants who were highly lucid during dreams had larger anterior prefrontal cortexes, which is the region of the brain that controls conscious cognitive processes and plays an important role in our ability to self reflect.

The team also took scans while the participants were solving waking self awareness tests. The scans revealed that lucid dreamers also had more brain activity happening in their prefrontal cortex than regular dreamers. This suggests that the same brain region is connected to both abilities. Their research has now been published in The Journal of Neuroscience.

"Our results indicate that self-reflection in everyday life is more pronounced in persons who can easily control their dreams," said Filevich in the release.

The researchers are now eager to find out whether these self awareness skills can be taught. Their next study will attempt to teach volunteers to lucid dream, and then see whether their self-reflection also improves as a result.

As someone who’s had plenty of lucid dreams myself, I’m still not entirely sure of the appeal. All the dreams that I'm lucid during, and particularly those I have some control over, are frustrating and exhausting and feel more like a mental marathon than rest.

But I can’t deny that it’s fascinating to discover more about how our brains work - both when we’re awake, and during sleep. Even if it is occasionally nice to have a little escape from awareness.

You can find out more about the science of lucid dreaming thanks to the guys over at AsapSCIENCE.

http://www.sciencealert.c(...)ables-lucid-dreaming

quote:

'Vogels in V-formatie werken onbaatzuchtig samen'

Vogels werken onbaatzuchtig samen bij het vliegen in een V-formatie. Dat blijkt uit een nieuwe studie met noordelijke kale ibissen.

Deze trekvogels vliegen in een zwerm allemaal net zo lang op de koppositie als in de slipstream van anderen.

Zo'n eerlijk verdeelde samenwerking is bijzonder zeldzaam in de dierenwereld.

Dat melden onderzoekers in het wetenschappelijk tijdschrift Proceedings of the National Academy of Sciences.
Vliegtuigje

De wetenschappers kwamen tot hun bevindingen door een uniek Oostenrijks project, waarbij noordelijke kale ibissen van jongs af aan hebben geleerd om te migreren door achter een vliegtuigje aan te vliegen.

Een zwerm van veertien van deze getrainde vogels werd door de wetenschappers van Oostenrijk naar Italië geleid. Elke ibis was uitgerust met een GPS-tag, zodat de posities van de vogels ten opzichte van elkaar zeer nauwkeurig in de gaten konden worden gehouden.

Na afloop van de tocht bleek uit een analyse van de GPS-gegevens dat er geen profiteurs in de zwerm zaten. "We vonden voor alle vogels een sterke correlatie tussen de tijd dat ze op kop vlogen en de tijd dat ze andere vogels volgden", verklaart hoofdonderzoeker Bernhard Voelkl op BBC News.
Evolutie

Dat gedrag is opmerkelijk, vooral omdat acht van de veertien vogels geen familieband hadden. Vanuit evolutionair oogpunt zouden dieren alleen gericht moeten zijn op hun eigen welzijn of dat van hun nakomelingen.

De wetenschappers vermoeden dat de vogels in zwermen onbaatzuchtig gedrag vertonen omdat positiewisselingen onmiddellijk invloed hebben op hun energieverbruik.

Als ze verzaken om de kop over te nemen, valt de formatie uit elkaar en moeten ze meer krachten verspillen. "Door hun energieverbruik te verminderen, verbeteren ze hun overlevingskansen", aldus Voelkl.http://www.nu.nl/wetensch(...)tzuchtig-samen-.html

SCIENTISTS HAVE FIGURED OUT HOW TO STOP THE COMMON COLD IN ITS TRACKS


1 billion infections per year - in the US alone
Plus Ebola, hepatitis C, HIV, polio, and many others.

BEC CREW 9 FEB 2015

We're still a long way off developing new drugs to combat them, but scientists have finally cracked the code used by a major group of virus to spread infections such as the common cold, Ebola, hepatitis C, HIV, and polio around the body.

This newly discovered code has been hiding inside the sequence of ribonucleic acid (RNA) - a nucleic acid involved in the coding, decoding, regulation, and expression of genes - that makes up the genome of the single-stranded RNA viruses group, which is considered one of the most potent and debilitating of groups of infectious pathogens. And once the scientists found it, they were able to decipher it.

“We have understood for decades that the RNA carries the genetic messages that create viral proteins, but we didn’t know that, hidden within the stream of letters we use to denote the genetic information, is a second code governing virus assembly,” one of the team, biophysicist Roman Tuma from the University of Leeds in the UK, told Laura Donnelly at The Telegraph. “It is like finding a secret message within an ordinary news report and then being able to crack the whole coding system behind it.”

Single-stranded RNA viruses are the most simple type of viruses known to science, and it’s thought that they were probably one of the first to evolve. And being around for a long time means they’re super-effective at what they do. Rhinovirus, which is the predominant cause of the common cold, is responsible for 1 billion infections per year - in the US alone.

The discovery has taken the team several years to complete, the first big step occurring in 2012, when Tuma and his colleagues published the first observations taken at a single-molecule level of how a single-stranded RNA virus fit its core into its outer shell. And it’s not just a case of stuffing it in like vacation wear into a suitcase - the core has to be very precisely folded in order to fit within the shape of the shell, made from a protective protein coating, and the virus has figured out how to do this in mere milliseconds. But how?

The next step involved mathematicians at the University of York in the UK, who worked with the Leeds group to come up with algorithms that could read the encrypted code that controls the complex folding process. Computer models were then built to replicate this coding system so the team had a better chance of cracking it.

The team compared these computer models to the Enigma machine, used famously during the 20th century to encipher and decipher secret messages, particularly during World War II.

Now, publishing in the Proceedings of the National Academy of Sciences, the team reports that they’ve finally done it. Using a visualising technique called single-molecule fluorescence spectroscopy, they watched the common plant disease - a single stranded RNA plant virus called the tobacco necrosis virus - use the code to replicate itself.

“The Enigma machine metaphor is apt,” says one of the team, Reidun Twarock from the University of York, in a press release. "The first observations pointed to the existence of some sort of a coding system, so we set about deciphering the cryptic patterns underpinning it using novel, purpose-designed computational approaches. We found multiple dispersed patterns working together in an incredibly intricate mechanism and we were eventually able to unpick those messages. We have now proved that those computer models work in real viral messages.”

Not only can the team read these coded messages within the genomes of the viruses, but they now know how to jam them and stop the spread of the virus in its tracks. The way to do this, says Tuma, is by designing molecules that can interfere with this secret code and scramble it, so the virus cannot fold its core properly and replicate. The team plans to work on this and start testing the method out on animal viruses.

http://www.sciencealert.c(...)n-cold-in-its-tracks

Alien star system buzzed the Sun



An alien star passed through our Solar System just 70,000 years ago, astronomers have announced.

No other star is known to have approached this close to us.

An international team of researchers says it came five times closer than our current nearest neighbour - Proxima Centauri.

The object, a red dwarf known as Scholz's star, cruised through the outer reaches of the Solar System - a region known as the Oort Cloud.

Scholz's star was not alone; it was accompanied on its travels by an object known as a brown dwarf. These are essentially failed stars that lacked the necessary mass to get fusion going in their cores.

The findings are published in Astrophysical Journal Letters.

Observations of the dim star's trajectory suggest that 70,000 years ago this cosmic infiltrator passed within 0.8 light years of the Sun. By comparison, Proxima Centauri is 4.2 light years away.

Close encounter

In the paper, astronomers led by Eric Mamajek at the University of Rochester, New York, say they are 98% certain that Scholz's star travelled through what is known as the "outer Oort Cloud" - a region at the edge of the Solar System filled with trillions of comets a mile or more across.

This region is like a spherical shell around the Solar System and may extend out to as much as 100,000 Astronomical Units, or AU (one AU is the distance between the Earth and the Sun).



The Oort Cloud is thought to give rise to long-period comets that can swing past the Sun when their orbits are disturbed.

Oort Cloud The Oort Cloud in perspective: 1 Astronomical Unit (AU) represents the distance from the Earth to the Sun
To determine the trajectory of the star, the researchers needed two pieces of information: the change in distance from the Sun to the star (its radial velocity) and the star's motion across the sky (its tangential velocity).

Scholz's star currently lies 20 light years away - making it a fairly nearby system. But it showed very slow tangential motion for a star this close. This indicated that it was either moving away from us or towards a future close encounter with the Solar System.

The radial velocity measurements confirmed that the binary star system was actually speeding away from us. By tracing its movements back in time, they found its close shave with the Sun occurred some 70,000 years ago.

Grand theft Oort-o?

A star passing through the Oort Cloud could potentially play gravitational havoc with the orbits of comets there, sending them on trajectories into the inner Solar System. But Dr Mamajek believes the effects of Scholz's star on our cosmic neighbourhood were "negligible".

"There are trillions of comets in the Oort cloud and likely some of them were perturbed by this object," he told BBC News.

"But so far it seems unlikely that this star actually triggered a significant 'comet shower'."

The effect of a passing star on the Oort Cloud is a function of the star's mass, speed and proximity. The worst case scenario for stirring up comets would be a slow-moving, massive star that came close to the Sun.

Scholz's star came relatively close, but the binary system (the red dwarf and its brown dwarf companion) has a low mass and it was speeding by. These factors conspired to make its effect on the Oort Cloud very small.

While this is the closest flyby detected so far, Dr Mamajek thinks it's not uncommon for alien stars to buzz the Sun. He says a star probably passes through the Oort Cloud every 100,000 years, or so.

But he suggests an approach as close - or closer - than that made by Scholz's star is somewhat rarer. Dr Mamajek said mathematical simulations show such an event occurs on average about once every nine million years.

"So it is a bit of a strange coincidence that we happen to have caught one that passed so close within the past 100,000 years or so," he said.

bron

20 February 2015 Last updated at 00:02 GMT

EVOLUTION 'FAVOURS BIGGER SEA CREATURES'

By Jonathan Webb
Science reporter, BBC News


Whales and other modern sea animals tend to be much larger than Cambrian sea creatures

The animals in the ocean have been getting bigger, on average, since the Cambrian period - and not by chance.

That is the finding of a huge new survey of marine life past and present, published in the journal Science.

It describes a pattern of increasing body size that cannot be explained by random "drift", but suggests bigger animals generally fare better at sea.

In the past 542 million years, the average size of a marine animal has gone up by a factor of 150.

It appears that the explosion of different life forms near the start of that time window eventually skewed decisively towards bulkier animals.

Today's tiniest sea critter is less than 10 times smaller than its Cambrian counterpart, measured in terms of volume; both are minuscule crustaceans. But at the other end of the scale, the mighty blue whale is more than 100,000 times the size of the largest animal the Cambrian could offer: another crustacean with a clam-like, hinged shell.

Big bias


The idea that natural selection might lead to animal lineages gradually gaining weight is far from new. It is set out in a proposal known as Cope's rule, after American fossil specialist Edward Drinker Cope.

19th-Century palaeontologists noticed that the ancient ancestors of modern mammals often tended to be smaller; horses, for example, can be traced to the dog-sized Eohippus genus of 50 million years ago.

The pattern is not consistent across the animal kingdom, however. Most groups of dinosaurs got bigger until they died out - but the birds that evolved from them grew smaller and lighter with the necessity of flight.

Dr Noel Heim, from Stanford University in California, set out to give Cope's rule its most thorough test yet - in the vast realm of the ocean.


One of the team's key sources was the 50-volume "Treatise on Invertebrate Paleontology"

He enlisted the help of colleagues, undergraduates and even high school interns, to scour the scientific record for body size data - including measuring countless illustrations from venerable palaeontological tomes.

"We've had at least 50 high school students working on it over the last five years," Dr Heim told BBC News.

"It would have taken many, many, many more years doing it on my own!"

Eventually the team had amassed information on more than 17,000 groups of species, called genera. This represents over 60% of all the animal genera ever to have lived.

It was detailed analysis of this formidable set of figures that revealed the trend towards increasing size.

But Dr Heim and his colleagues say the consistent trend does not mean that every single genus of animals evolved to grow larger.

Instead, the branches of the family tree that were populated by larger animals divided many more times - diversifying and expanding so that the ocean gradually built up a greater variety of bigger and bigger beasts.

Faster movers, better eaters

The team also wanted to work out whether this bigness bias was really driven by evolutionary advantage, or was simply a matter of chance.

To this end, they put their size data from the oldest animals into a computer model and ran multiple simulations of how the family tree might evolve. Each species could die out, stay the same, or get bigger or smaller.

In some simulations, the scientists allowed the animals' size to drift randomly without affecting each species' success; in others, they tweaked the rules so that bigger animals were more likely to survive and flourish.

The version that best matched the real fossil history was one with a genuine size advantage.

"The degree of increase in both mean and maximum body size just aren't well explained by neutral drift," said Dr Heim. "It appears that you actually need some active evolutionary process that promotes larger sizes."

As for what those benefits of extra bulk might be, the researchers cannot be sure - but larger species likely took advantage of being able to move faster, burrow better in sediment, or eat larger prey.

The changing chemistry of the ocean, including an increase in oxygen, may also have played a role, Dr Heim suggested.


Breathing air helped marine reptiles to maintain their extra body size

Dr Michael Berenbrink, an evolutionary physiologist at the University of Liverpool, said the US team had compiled "an incredible data set".

He cautioned that the results should be interpreted carefully, noting particularly that the size increase was not just the gradual progression that a straightforward application of Cope's rule might predict.

Certain key events, also highlighted by the study's authors, deliver an extra boost. Most obviously, at the stages when land animals like reptiles and, later, mammals returned to the water, the size graph lurched upward.

It was the return of mammals, after all, that eventually produced the modern giants of the sea: whales.

"You can see in the data, there is this trend to increasing size - but a real kick comes when you have these air-breathers re-entering the water," Dr Berenbrink told the BBC.

"Then you have a sort of a step change in size."

Breathing air delivers extra oxygen to an animal's tissues, he explained, allowing them to sustain bigger bodies beneath the waves.

Dr Heim agrees that these events are important, but emphasises the huge diversity of other life forms - the fish, molluscs and other invertebrates - which together continued on a trajectory of expanding size.

"[Marine mammals and reptiles] are not driving the trend," he said. "They're really big, but in terms of diversity there's just not that many of them.

"They actually have a fairly small impact on the mean size."

http://www.bbc.com/news/science-environment-31533744

INCREDIBLE DRONE FOOTAGE OF THE WORLD'S LARGETS CAVE

It's like its own little ecosystem.

http://www.sciencealert.c(...)world-s-largest-cave

SCIENTISTS CAN NOW TELL IF YOU'RE IN LOVE BY SCANNING YOUR BRAIN

And they know if you're faking it.

FIONA MACDONALD 16 MAR 2015

Love is one of the biggest human mysteries - people write songs about it, die for it and dedicate their lives to it. But what, exactly, is it? Scientists believe that they may finally have found the answer, after discovering the first evidence of changes in the love-struck brain.

The team scanned the brains of 100 students recruited from Southwest University in China and found clear changes in the areas of the brain involved in reward, motivation, emotion and social interactions when someone was in love. Their results have been published in Frontiers in Human Neuroscience, and you can see the full figure above here.

"The results shed light on the underlying neural mechanisms of romantic love, and demonstrate the possibility of applying a resting-state fMRI approach for investigating romantic love," the authors wrote in the paper.

The researchers used resting state functional magnetic resonance imaging (fMRI) to compare the brain activity of three different groups - 34 people who had been in love for between four and 18 months, 34 who had recently broken up with someone they loved, and 32 who had never been in love at all. Across the three groups there was no significant difference in age, personal monthly expenses, family income, or years of education.

During the scans, the participants were told to think of nothing in particular, so the scientists could get an understanding of how their brains worked overall.

They found that those who were "in love" had increased activity in several areas of their brains, including the dorsal anterior cingulate cortex, insula, caudate, amygdala, and nucleus accumbens, as well as the temporo-parietal junction, posterior cingulate cortex, medial prefrontal cortex, inferior parietal, precuneus, and temporal lobe.

In many of these brain regions, the amount of activity they saw was linked to the amount of time someone had been in love. So, the longer they'd loved someone, the more activity they experienced.

On the other hand, the longer the "ended love" group had been broken up, the lower activity in these regions. They also showed that one area of the brain, the caudate nucleus, seemed to be involved in helping people cope with the end of a love affair.

Of course, knowing this isn't really going to help you work out whether or not your boyfriend or girlfriend really loves you, or even whether your love is the kind of love that's going to last. But the researchers believe it could lead to a better understanding of the emotion, and could give scientists the ability to 'diagnose' whether someone really is in love or not.

However, before we get too carried away, there are a few flaws the study, the biggest being that its findings are all based on students self-classifying whether or not they were in love in the first place. And there's also not a clear base level of brain activity established. An interesting follow-up would be to compare people's brain activity between when they're in love to when they aren't to eliminate individual neural differences.

The researchers acknowledge this, and explain that longitudinal studies are now needed to verify their findings. And they also put forward another (slightly depressing) limitation of their study: "We do not know exactly whether love-related alterations are adaptation, or maladaptation in lovers." Which basically means they're not sure whether the brain-changing experience of falling head over heels in love is doing us more harm than good, and they suggest future studies determine this.

So there's still a lot to learn about love, but as far as taking steps towards understanding the biological basis of human emotions go, this is a pretty big one. We can't wait to find out more.

http://www.sciencealert.c(...)-scanning-your-brain

YOUR EYES ARE WIRED BACKWARDS: HERE'S WHY

Mystery SOLVED.

SCIENCEALERT STAFF

19 MAR 2015

This article was written by Erez Ribak from the Technion - Israel Institute of Technology, and was originally published at The Conversation.

The human eye is optimised to have good colour vision at day and high sensitivity at night. But until recently it seemed as if the cells in the retina were wired the wrong way round, with light travelling through a mass of neurons before it reaches the light-detecting rod and cone cells. New research presented at a meeting of the American Physical Society has uncovered a remarkable vision-enhancing function for this puzzling structure.

About a century ago, the fine structure of the retina was discovered. The retina is the light-sensitive part of the eye, lining the inside of the eyeball. The back of the retina contains cones to sense the colours red, green and blue. Spread among the cones are rods, which are much more light-sensitive than cones, but which are colour-blind.

Before arriving at the cones and rods, light must traverse the full thickness of the retina, with its layers of neurons and cell nuclei. These neurons process the image information and transmit it to the brain, but until recently it has not been clear why these cells lie in front of the cones and rods, not behind them. This is a long-standing puzzle, even more so since the same structure, of neurons before light detectors, exists in all vertebrates, showing evolutionary stability.

Researchers in Leipzig found that glial cells, which also span the retinal depth and connect to the cones, have an interesting attribute. These cells are essential for metabolism, but they are also denser than other cells in the retina. In the transparent retina, this higher density (and corresponding refractive index) means that glial cells can guide light, just like fibre-optic cables.

SELECTIVE VISION

In view of this, my colleague Amichai Labin and I built a model of the retina, and showed that the directional of glial cells helps increase the clarity of human vision. But we also noticed something rather curious: the colours that best passed through the glial cells were green to red, which the eye needs most for daytime vision. The eye usually receives too much blue – and thus has fewer blue-sensitive cones.

Further computer simulations showed that green and red are concentrated five to 10 times more by the glial cells, and into their respective cones, than blue light. Instead, excess blue light gets scattered to the surrounding rods.

This surprising result of the simulation now needed an experimental proof. With colleagues at the Technion Medical School, we tested how light crosses guinea pig retinas. Like humans, these animals are active during the day and their retinal structure has been well-characterised, which allowed us to simulate their eyes just as we had done for humans. Then we passed light through their retinas and, at the same time, scanned them with a microscope in three dimensions. This we did for 27 colours in the visible spectrum.

The result was easy to notice: in each layer of the retina we saw that the light was not scattered evenly, but concentrated in a few spots. These spots were continued from layer to layer, thus creating elongated columns of light leading from the entrance of the retina down to the cones at the detection layer. Light was concentrated in these columns up to 10 times, compared to the average intensity.

Even more interesting was the fact that the colours that were best guided by the glial cells matched nicely with the colours of the cones. The cones are not as sensitive as the rods, so this additional light allowed them to function better – even under lower light levels. Meanwhile, the bluer light, that was not well-captured in the glial cells, was scattered onto the rods in its vicinity.

These results mean that the retina of the eye has been optimised so that the sizes and densities of glial cells match the colours to which the eye is sensitive (which is in itself an optimisation process suited to our needs). This optimisation is such that colour vision during the day is enhanced, while night-time vision suffers very little. The effect also works best when the pupils are contracted at high illumination, further adding to the clarity of our colour vision.The Conversation

This article was originally published at The Conversation. Read the original article.

http://www.sciencealert.c(...)backwards-here-s-why

STAR'S BIRTH GLIMPSED 'IN REAL TIME'

3 April 2015



Data from 1996 - illustrated here as a 3D simulation - showed a compact, round blast of wind (in blue)

Astronomers have witnessed a key stage in the birth of a very heavy star, using two radio telescope views of the process taken 18 years apart.


The young star is 4,200 light-years from Earth and appears to be surrounded by a doughnut-shaped cloud of dust.

That cloud slows down the hot, ionised wind that the star blasts into space, causing it to form an elongated column perpendicular to the dusty ring.

The new results represent "before and after" glimpses of that column forming.

They were captured by the Very Large Array, a battery of 27 antennae in the New Mexico desert, and are published in the journal Science.

"The comparison is remarkable," said first author Carlos Carrasco-Gonzalez, from the National Autonomous University of Mexico. The compact, rounded wind indicated by data from 1996 transforms - just 18 years later in 2014 - into a "distinctly elongated outflow".

One to watch

The infant star is about 300 times brighter than the Sun and goes by the catchy name of W75N(B)-VLA2.

Being able to observe its dramatic growing pains in real time is unique, according to Prof Huib van Langevelde from Leiden University in the Netherlands, another of the study's authors.


The 2014 data revealed the wind to be much more elongated, emerging from the presumed ring of dust

"This object is providing us an exciting opportunity to watch the developments over the next few years, as this very young star develops the characteristic bipolar outflow morphology," said Prof van Langevelde, who also works at the Joint Institute for VLBI in Europe (JIVE).

VLBI - very long baseline interferometry - is the method of comparing signals between widely-spaced antennae, effectively simulating one massive telescope.

One of the major findings that has already emerged from studying W75N(B)-VLA2 relates to earlier work led by JIVE scientists, who in 2009 traced the large-scale magnetic field in that region of space and reported that the field surrounding the young star was neatly aligned with it.

Now, it seems the elongated outflow that has burst forth in just 18 years is also aligned with that magnetic field - suggesting that magnetism is playing a crucial role in the star's formation.

The team hopes to watch and learn more as the "protostar" continues its turbulent development.

"Our understanding of how massive young stars develop is much less complete than our understanding of how Sun-like stars develop," said Dr Gabriele Surcis, another co-author from JIVE.

"It's going to be really great to be able to watch one as it changes."

http://www.bbc.com/news/science-environment-32168507

quote:

Op donderdag 9 april 2015 08:47 schreef ExperimentalFrentalMental het volgende:
08-04-2015

Terminaal zieke man krijgt mogelijk eerste complete hoofdtransplantatie ooit

[ afbeelding ]
© Twitter, Daily Mail, Daily Mirror.

De 30-jarige Valery Spiridonov heeft zich aangemeld om de eerste mens ooit te worden die een complete hoofdtransplantatie zal ondergaan. Je hoort het goed, zijn hoofd wordt mogelijk integraal op het lichaam van iemand anders geplaatst. "Mijn beslissing is genomen en ik ben niet van plan om van gedacht te veranderen", zegt hij vastberaden.

De Russische Valery werd geboren met een ernstige genetische spierziekte. Hij wil de radicale operatie graag ondergaan omdat zijn toestand elk jaar verergert. "Als ik deze kans niet grijp, dan ziet mijn lot er heel triestig uit", zegt hij. "Ben ik bang? Natuurlijk. Maar het is niet alleen beangstigend, het is ook heel interessant."

[ afbeelding ]

De controversiële Italiaanse dokter Sergio Canavero, die de operatie zal uitvoeren, wordt door vele sceptici 'gestoord' genoemd. Maar hij is er rotsvast van overtuigd dat een complete hoofdtransplantatie wel degelijk mogelijk is.

[ afbeelding ]

Hij kreeg al heel wat aanvragen (?), maar staat erop dat de eerste patiënten, net zoals Valery, aan een spierziekte lijden en dus echt een nieuw lichaam kunnen gebruiken. Hij heeft Valery nu geïdentificeerd als eerste patiënt. De twee hebben elkaar nog niet in het echt ontmoet, maar hebben wel al contact gehad via Skype. De chirurg wil nu nog zeker twee jaar tijd om alle nodige voorbereidingen te treffen. In 2017 wil hij de operatie uitvoeren.

'Dr. Frankenstein' of wereldverbeterende pionier?
In 1970 onderging een aap voor het eerst een hoofdtransplantatie. Het aapje stierf acht dagen later omdat het lichaam het nieuwe hoofd afstootte. Voor de aap stierf bleek hij niet te kunnen bewegen omdat onder andere de ruggengraat niet voldoende verbonden was. De aap kon ook niet zelfstandig ademen. Volgens dokter Canavero staat hij met zijn plannen ondertussen al heel wat verder en bestaan nu ook alle technieken om een hoofd over te zetten op een donorlichaam.

Critici noemen Canavero 'Dr. Frankenstein' en vinden zijn plannen pure fictie. Moest dokter Canavero toch in dit huzarenstukje slagen, bezorgt hij met zijn pionierende operatie wel meteen voor hoop voor heel wat verlamde en gehandicapte mensen. "Voor de eerste man de ruimte in ging dacht men ook aan alles wat er fout kon gaan", zegt Valery. "Als je wil dat iets lukt, moet je er aan participeren", concludeert hij moedig.

Head transplantation -- The future is now | Dr. Sergio Canavero | TEDxLimassol

(HLN)

Ik geloof er geen fuck van

quote:

Op donderdag 9 april 2015 09:00 schreef ExperimentalFrentalMental het volgende:

[..]

Het is niks nieuws hoor, ze hebben al sinds de vorige eeuw experimenten gedaan met honden en apen, Ik ben echter ook sceptisch of het al binnen 2 jaar mogelijk zal zijn.bij een mens. En dan hebben we t nog niet over ethische implicaties...

Ze kunnen een dwarslesie nog steeds niet herstellen maar dit zou wel moeten lukken? Of neemt hij genoegen met een gevoelloos lichaam en leven in een rolstoel, weinig verschil met de huidige situatie behalve dat hij er langer mee kan leven.

13-04-2015

Universum dijt mogelijk toch niet zo snel uit als gedacht



Wetenschappers hebben ontdekt dat supernova’s die gebruikt worden om afstanden in het heelal te meten niet zo uniform zijn als gedacht. Het zou kunnen betekenen dat het universum toch niet zo snel uitdijt als gedacht.

Onderzoekers bestudeerden de supernova’s van type Ia. Aangenomen werd dat deze supernova’s allemaal evenveel licht geven. Door de helderheid van deze sterren te meten, kunnen onderzoekers dan ook vaststellen op welke afstand de supernova’s vanaf de aarde staan. Tenminste: dat dachten we. Nieuw onderzoek suggereert namelijk dat supernova’s van het type Ia helemaal niet zo uniform zijn.

Wetenschappers hebben ontdekt dat er verschillen zijn in de helderheid van deze supernova’s en dat de supernova’s op basis van die verschillen in twee groepen in te delen zijn. “De groep die nabij ons in de minderheid is, is op grotere afstanden – en dus toen het universum jonger was – in de meerderheid,” legt onderzoeker Peter Milne uit. “Er is sprake van verschillende populaties en dat hebben we niet eerder erkend. We namen altijd aan dat hoe ver ze ook van je verwijderd zijn, supernova’s van het type Ia altijd hetzelfde zijn. Maar dat blijkt niet zo te zijn.”

Het onderzoek heeft mogelijk implicaties voor de uitdijing van het heelal. Wetenschappers hebben namelijk onder meer supernova’s van het type Ia gebruikt om de snelheid waarmee het heelal uitdijt, vast te stellen. Uit hun onderzoek bleek dat veel supernova’s minder helder zijn, omdat ze door een versnelde uitdijing van het heelal tegenwoordig op grotere afstand van de aarde staan. “Het idee achter deze redenering was dat supernova’s van het type Ia allemaal dezelfde helderheid hebben en er dus – ongeacht waar ze ontploffen – hetzelfde uitzien. De verre supernova’s zouden er net zo uitzien als de supernova’s die dichtbij ons staan, maar omdat ze minder helder zijn dan verwacht gingen mensen ervan uit dat ze op een grotere afstand stonden. En dat heeft geleid tot de conclusie dat het universum nu sneller uitdijt dan in het verleden.”

(scientias.nl)

14-04-2015

Eerste gedetailleerde kaart van donkere materie is een feit

Onderzoekers hebben voor het eerst een gedetailleerde kaart afgeleverd waarop te zien is hoe donkere materie in het heelal verspreid is. Vooralsnog lijkt deze kaart onze ideeën over donkere materie te bevestigen.

Ongeveer een kwart van het universum bestaat naar schatting uit donkere materie. Maar donkere materie is onzichtbaar en dus niet zo gemakkelijk in kaart te brengen. Om een beeld te krijgen van de verdeling van donkere materie in het heelal, moeten onderzoekers dan ook kijken naar de zwaartekrachtsinvloed die donkere materie op de omgeving heeft. “We maten de bijna niet waarneembare verstoringen in de vormen van ongeveer twee miljoen sterrenstelsels om deze nieuwe kaarten te maken,” vertelt onderzoeker Vinu Vikram.


_{De kaart laat de verspreiding van donkere materie zien. De kleuren vertellen iets over de dichtheid: de dichtheid van de materie is groter in de rode en gele gebieden. De grijze stippen zijn clusters (hoe groter de stip, hoe groter het cluster). Afbeelding: Dark Energy Survey.}

Dark Energy Camera
De kaarten zijn gemaakt met behulp van de Dark Energy Camera. Deze camera bevindt zich op een telescoop in Chili. Vooralsnog hebben de onderzoekers één kaart vrijgegeven. Deze kaart beslaat ongeveer drie procent van het deel van het heelal dat de Dark Energy Camera tijdens zijn vijf jaar durende missie zal bestuderen.

Toets de theorie
Met behulp van de kaarten hopen onderzoekers te achterhalen of hun ideeën over de vrij mysterieuze donkere materie kloppen. Eén van die ideeën stelt bijvoorbeeld dat – omdat er veel meer donkere materie is dan zichtbare materie – sterrenstelsels zullen ontstaan op plekken waar de concentratie donkere materie groot is. Tot op heden lijkt de Dark Energy Camera dat idee te onderschrijven. De kaarten laten lange ‘slierten’ materie zien waarin zich veel sterrenstelsels en clusters bevinden en ‘lege gebieden’ waarin heel weinig sterrenstelsels te vinden zijn.

“Onze analyse is tot zover in lijn met wat we voorspelden,” stelt onderzoeker Chihway Chang. “Door in te zoomen op de kaarten hebben we kunnen meten hoe donkere materie sterrenstelsels van verschillende typen omwikkelt en hoe zij samen door de tijd heen evolueren. We kijken ernaar uit om de nieuwe gegevens die nu binnenkomen te gebruiken om theoretische modellen nog verder te beproeven.”

(scientias.nl)