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Turing's theory of chemical morphogenesis validated 60 years after his death

Turing's theory of chemical morphogenesis validated 60 years after his death | Communicating Science | Scoop.it

Alan Turing's accomplishments in computer science are well known, but lesser known is his impact on biology and chemistry. In his only paper on biology, Turing proposed a theory of morphogenesis, or how identical copies of a single cell differentiate, for example, into an organism with arms and legs, a head and tail.

Now, 60 years after Turing's death, researchers from Brandeis University and the University of Pittsburgh have provided the first experimental evidence that validates Turing's theory in cell-like structures.

 

The team published their findings in the Proceedings of the National Academy of Sciences on Monday, March 10.

 

Turing was the first to offer an explanation of morphogenesis through chemistry. He theorized that identical biological cells differentiate, change shape and create patterns through a process called intercellular reaction-diffusion. In this model, a system of chemicals react with each other and diffuse across a space—say between cells in an embryo. These chemical reactions need an inhibitory agent, to suppress the reaction, and an excitatory agent, to activate the reaction. This chemical reaction, diffused across an embryo, will create patterns of chemically different cells.

 

Turing predicted six different patterns could arise from this model. At Brandeis, Seth Fraden, professor of physics, and Irv Epstein, the Henry F. Fischbach Professor of Chemistry, created rings of synthetic, cell-like structures with activating and inhibiting chemical reactions to test Turing's model. They observed all six patterns plus a seventh unpredicted by Turing.


Via Dr. Stefan Gruenwald
The Science & Education team's insight:

Turings achievements continue to amaze:

http://www.abc.net.au/radionational/programs/scienceshow/alan-turing-e28093-thinker-ahead-of-his-time/4034006

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Vale Oliver Sacks

Vale Oliver Sacks | Communicating Science | Scoop.it
Sacks was able to communicate the fascinating workings of the brain in ways that evoked understanding and compassion.

 

Oliver Sacks achieved global public renown because his writings melded two particular traits that cut across his dual role as doctor and writer: his focus on single patients rather than large populations and his profound empathy.

These unique characteristics underpinned the distinctive contribution that the famed neuroscientist – who this week died of cancer at age 82 – made to the public’s understanding of medicine.

Like no other writer, he showed readers how a compassionate doctor can treat the most misunderstood and marginalized patients by accessing their mysterious inner worlds.

People over data

Scientists who study neurological conditions such as Parkinson’s will often study the condition across hundreds or thousands of patients, searching for common traits that will lead clinicians to the core of the disorder.

The more patients in a study, the stronger the evidence for scientists to draw general conclusions about the condition. One case is viewed as the weakest form of evidence. (Old joke: what is the plural of anecdote? Data.)

But Sacks, in contrast, saw the nature of neuroscience written in the lives of single patients. And he rendered those lives in vivid prose.

Dr P, the eponymous character in his bestselling collection of essays The Man Who Mistook His Wife for a Hat, was not a generalized abstraction. He was a charming man, a singer and music teacher.

But, wrote Sacks, a massive tumor or degenerative process in the visual parts of the brain meant he could not recognize objects in the world. When asked by Sacks to put on his hat, he reached and grabbed his wife’s head.

Through a step-by-step process of observation and reflection, Sacks shows readers how Dr P used music to navigate the world: he could only perform tasks, like getting dressed, while singing quietly to himself.

Sacks' focus on the detailed description of single cases also differentiated him from other scientist-writers. Stephen Hawking’s A Brief History of Time and Richard Dawkins’ The Ancestor’s Tale are examples of books that presented sweeping narratives, taking place over eons.

Sacks, instead, went for vivid description of the single life.

For Sacks, it was both a scientific method and a literary device. Its wider consequence was that popular science books became ways to transmit original, compelling scientific evidence and ideas to mainstream audiences.

Penetrating the mind

The second characteristic that underpinned his success as a doctor and writer was his uncanny empathy.

As Sacks wrote in An Anthropologist on Mars:

The realities of patients, the ways in which they and their brains construct their own worlds, cannot be comprehended wholly from the observation of behavior, from the outside.

 

In order to do this, he needed to infiltrate their consciousness. He needed to see the world as they did. He needed to understand them from the inside.

In one chapter, Sacks introduces readers to Dr Carl Bennett, a surgeon with Tourette’s. Sacks travels to Bennett’s house and hospital in British Columbia, where he witnesses the surgeon’s incessant tics and twitches at home – but flawless composure in the operating room.

Sacks shows readers how the manifestations of Tourette’s vanish once Bennett assumes the role of surgeon and engages in the rhythmic routine of surgery.

On a personal level, I identified with this technique, and in a way, Sacks diagnosed me through popular science. Browsing in a bookstore as a student, I flipped through Sacks’ Migraine, first published in 1970. I read descriptions of patients with the condition. I saw in its pages drawings by migraine sufferers showing how their vision was disturbed at the onset of a crippling headache.

For years, I’d had the same (then unexplained) headaches, the same visual disturbances – zigzag lines in front of my face, half my vision blurred.

Sacks had described my experience perfectly – from the inside.

The New York Times once called Sacks “a kind of poet laureate of contemporary medicine.” But that description, for me, does not fully describe Sacks’ distinctive ability to move between the roles of doctor and writer, putting the individual at the center of medicine and understanding one single patient at once objectively and subjectively.

The preface to An Anthropologist on Mars describes his work best. There, Sacks explains that he gave up much of his hospital work in order to visit patients where they lived their lives, offering “house calls at the far borders of human experience.”

His distinctive sensibility as a doctor-writer explains why one million copies of his books are still in print in the United States – and will continue to be read and used as models for future forays by other writers into the human condition.

The Science & Education team's insight:

See also:

https://theconversation.com/celebrating-oliver-sacks-romantic-science-and-a-life-now-ending-42242

`
https://www.ted.com/talks/oliver_sacks_what_hallucination_reveals_about_our_minds

 

http://www.nytimes.com/2015/08/31/science/oliver-sacks-dies-at-82-neurologist-and-author-explored-the-brains-quirks.html?emc=eta1&_r=0 ;

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A colour scheme for a feathered dinosaur

A colour scheme for a feathered dinosaur | Communicating Science | Scoop.it

Researchers have taken cues from tiny, 150-million-year-old fossilized organelles to figure out the color of a feathered dinosaur from the Jurassic period, R&D Magazine reports. The study, published in Scientific Reports, looks at fossilized organelles (called melanosomes) that contain melanin, a type of pigment that suggests a color scheme for the birdlike dinosaur: gray feathers on its body, a reddish mohawk down the center of its head, and white feathers with black tips that line the creature’s wings and legs.

The Science & Education team's insight:

Fascinating that we can actually identify the colour of dinosaurs

http://www.rdmag.com/articles/2015/09/chemical-analysis-finds-pigments-persist-dino-feathers

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Artificial photosynthesis developments

Artificial photosynthesis developments | Communicating Science | Scoop.it
A new solar fuel generation system, or artificial leaf, developed by researchers at JCAP safely creates fuel from sunlight and water with record-setting efficiency and stability.
The Science & Education team's insight:

Progress (10% efficiency) but still some distance to go

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The physics of pulling apart interleaved books

The physics of pulling apart interleaved books | Communicating Science | Scoop.it
Take two phone books and lie them face up, with the spines facing away from each other. Then interleave the pages and try to pull the books apart. You will fail.

 

eople, trucks and even military tanks have tried and failed the task of pulling apart two phone books lying face up with their pages interleaved, like a shuffled deck of cards. While physicists have long known that this must be due to enormous frictional forces, exactly how these forces are generated has been an enigma – until now.

A team of physicists from France and Canada has discovered that it is the layout of the books coupled with the act of pulling that is producing the force.

 

The power of approximation

Finding an approximate solution to a complex problem is an essential skill in science (and in life). Often we are faced with questions that we can’t answer exactly, but sometimes good enough is, well, good enough. Enrico Fermi, one of the greatest physicists in the 20th century, has given his name to such “Fermi Questions” – as he was famous for encouraging this skill in his students.

Here’s one example: “How many piano tuners are there in Chicago?”. I have no idea, and I’m not sure Fermi knew either. But by estimating the population of Chicago, the fraction that might play the piano, and how often a piano needs tuning, you can come up with a pretty good guess, without diving into the phone book (it’s probably closer to 100 than to 1,000).

Doing these “back-of-an-envelope” calculations is usually the first step in approaching a scientific question. Sometimes that is as far as you need to go. Sometimes it tells us that the question is worth investigating more to find the exact answer.

Not even Brian Blessed can do it.

This is exactly what the team investigating the friction of phone books did. The back-of-the-envelope answer is friction between the pages. However, assuming the friction is proportional to the number of pages drastically underestimates the total force that is generated (which seems to rise exponentially with the number of pages). But previous attempts to improve this simple model – by including the effects of gravity and air pressure pushing the pages of the books together – have all failed to explain the result.

 

Surprisingly simple

So, when the back-of-the-envelope calculation fails, things get serious. In this case, the traction instrument was brought out (think the opposite of a vice), it was used to pull books apart while measuring the force required to do so. But not just any books. Rigorously prepared test books with specific numbers of pages, built from paper sheets of exact dimensions, interleaved to high precision.

Data in hand, a mathematical model was put together, and it turned out to be driven by a surprisingly simple fact. The pages of each book are separated by the interleaving and end up “spreading out”, lying at a slight angle from the spine. When the books are pulled away from each other, the pages want to move back closer together and end up squeezing the interleaved pages from the other book. And gripping something tightly greatly increases the friction.

Just impossible.

As an example, imagine a person with long hair in a swimming pool. While floating underwater, their hair can spread out – much like the pages of the books are spread out by the interleaving. Then, if our volunteer swims off, their hair will naturally move close together, following their head which is pulling it along. The pages of our books also want to move close together behind the thing pulling them (the spine of the book), but instead just squeeze more tightly on the pages of the other book, which are in the way. Pulling harder on the books only increases the friction.

This is an example of the geometrical amplification of friction, or how the layout of the books produces forces far beyond what is expected. Knots are another example, looping a rope around itself greatly increases the friction, resulting in a secure grip. The authors point out the recent resurgence of interest in this kind of problem and the general field of tribology, the study of surfaces in relative motion.

This is being driven by the need to understand the structure and behaviour of new micro and nano-engineered materials, which have impact on many aspects of life from medical applications to solar cells. Interleaved carbon nano-tubes as the material of the future anyone?

The Science & Education team's insight:

A lovely piece of science communication including videos and (some) subheadings

 

Shows the virtue of taking an old science problem and looking at it again.

 

http://arxiv.org/abs/1508.03290

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Gamma Ray Bursts linked to Galaxy Collisions

Gamma Ray Bursts linked to Galaxy Collisions | Communicating Science | Scoop.it

Gamma ray bursts (GRBs) are among the most dramatically explosive events in the universe. They’re often dubbed the largest explosions since the Big Bang (it’s pretty hard to quantify how big the Big Bang was, but suffice it to say it was quite large). There are two classes of GRBs: long-duration and short-duration. Long-duration GRBs (which interest us today) are caused when extremely massive stars go bust.

 

Fig 1. – Long-duration GRBs are thought to form during the deaths of the most massive stars. As the stars run out of fuel (left to right) they star fusing heavier elements together until reaching iron (Fe). Iron doesn’t fuse, and the star can collapse into a black hole. As the material is sucked into the black hole, a powerful jet can burst out into the universe (bottom left), which we would observe as a GRB.

The most massive stars burn through their fuel much faster, and die out much more quickly than smaller stars. Therefore, long-duration GRBs should only be seen in galaxies with a lot of recent star formation. All the massive stars will have already died in a galaxy which isn’t forming new stars. Lots of detailed observations have been required to confirm this connection between GRBs and their host galaxies. It’s, in fact, one of the main pieces of evidence for the massive-star explanation.

The authors of today’s paper studied the host galaxy of a long-duration GRB with an additional goal in mind. Rather than just show that this galaxy is forming lots of stars, they wanted to look at its gas to explain why it’s forming so many stars. So, they went looking for neutral hydrogen gas in the galaxy. Neutral gas is a galaxy’s fuel for forming new stars. Understanding the properties of the gas should tell us about the way in which the galaxy is forming stars.

Hot, ionized hydrogen is easy to observe, because it emits a lot of light in the UV and optical ranges. This ionized hydrogen is found right around young, star-forming regions, and so has been seen in GRB hosts before. But the cold, neutral hydrogen – which makes up most of a galaxy’s gas – is much harder to observe directly. It doesn’t emit much light on its own, but one of the main places it does emit is in the radio band: the 21-cm line. For more information on the physics involved, see this astrobite page, but suffice it to say that pretty much all neutral hydrogen emits weakly at 21 cm.

This signal is weak enough that it hasn’t been detected in the more distant GRB hosts. Today’s authors observed the host galaxy of the closest-yet-observed GRB (980425), which is only 100 million light-years away: about 50 times farther away than the Andromeda galaxy. This is practically just next-door, compared to most GRBs. This close proximity allowed them to make the first ever detection of 21-cm hydrogen emission from a GRB host galaxy.

Using powerful radio observations – primarily from the Giant Metrewave Radio Telescope – the authors made maps of hydrogen 21-cm emission across the galaxy. They found a large disk of neutral gas, which was thickest in the region around where the GRB went off. Denser gas leads to more ongoing star formation, which as we know can mean that very massive stars may still be around to become GRBs.

The most important finding, however, was that the gas disk had been disturbed: more than 21% of the gas wasn’t aligned with the disk. This disturbance most likely came from a merger with a smaller galaxy, that mixed up the disk when passing by. The authors argue that this merger could have helped get the star-formation going. By shock-compressing the gas, the disturbance would have kick-started the galaxy into forming stars and, eventually, resulted in the GRB.

This paper is quite impressive, as it shows that astronomers are probing farther into the link between GRBs and their host galaxies. Astronomers have known for a while that GRBs are sign-posts to galaxies which are forming lots of stars. But today’s paper used radio observations of the gas to connect that star formation to a recent merger. Most GRB hosts are much farther away, and similar observations will be difficult. But with more sensitive observatories – like ALMA or the VLA – it may be possible to see whether the gas of more GRB hosts show evidence of mergers. Perhaps GRBs are telling us even more about their galaxies than we had thought before?

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News - Meteorite Impacts Can Create DNA Building Blocks | Tohoku University Global Site

News - Meteorite Impacts Can Create DNA Building Blocks | Tohoku University Global Site | Communicating Science | Scoop.it

 Researchers from Tohoku University, National Institute for Materials Science and Hiroshima University discovered this after conducting impact experiments simulating a meteorite hitting an ancient oceanct on earth.

With precise analysis of the products recovered after impacts, the team found the formation of nucleobases and amino acids from inorganic compounds. The research is reported this week in the journal Earth and Planetary Science Letters.

All the genetic information of modern life is stored in DNA as sequences of nucleobases. However, formation of nucleobases from inorganic compounds available on prebiotic Earth had been considered to be difficult.

In 2009, this team reported the formation of the simplest amino acid, glycine, by simulating meteorite impacts. This time, they replaced the carbon source with bicarbonate and conducted hypervelocity impact experiments at 1 km/s using a single stage propellant gun (Figure 2).

Figure 2: Single stage propellant gun at National Institute for Materials Science Japan used for the hypervelocity impact experiments.

They found the formation of a far larger variety of life's building blocks, including two kinds of nucleobases and nine kinds of proteinogenic amino acids. The results suggest a new route for how genetic molecules may have first formed on Earth.

Publication Details :
Nucleobases and amino acids formation through impacts of meteorites on the early ocean. Authors: Furukawa Y., Nakazawa H., Sekine T., Kobayashi T., Kakegawa T.,
Journal: Earth and Planetary Science Letters (2015), http://dx.doi.org/10.1016/j.epsl.20015.07.049
The Science & Education team's insight:

An interesting study reported in a straightforward manner which highlights how little we know about the formation of life on earth (and even less elsewhere)

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Turkish whistled language processed equally on both sides of the brain

Turkish whistled language processed equally on both sides of the brain | Communicating Science | Scoop.it
Study challenges traditional model of how the brain processes language

 

 Listen closely in Kusköy, a mountainous region of northeast Turkey, and you might hear something like this whistled phrase trill across a steep valley. What you hear is not birdsong, but a version of the Turkish language that is whistled instead of spoken, a method that can convey messages across distances of up to 5 kilometers. In kuş dili, or “bird language,” the phrase means “thank you very much” (çok teşekkür ederim in spoken Turkish). Now, a new study shows that the brain processes kuş dili very differently from spoken Turkish, a finding that challenges conventional wisdom about how language works in the brain. The research could also have implications for stroke victims suffering from language loss. 

One of a handful of whistled languages throughout the world, whistled Turkish is still Turkish—it has the same words and the same grammatical structure—but it has a different physical form. A whistle replaces the voice, just as written words replace speech in languages around the world, says bioacoustician and linguist Julien Meyer, at France's National Center for Scientific Research in Bron, France, who was not involved in the new study. People who use kuş dili speak ordinary Turkish as well; the whistled version probably arose as a way for villagers to stay in touch when they were far apart.

 

 

Onur Güntürkün

“Speakers” of whistled Turkish process the language equally on the left and right sides of the brain.

Whistled Turkish tickles both sides of the brain 

Emily is a staff writer at Science.

Email EmilyByEmily Underwood17 August 2015 1:15 pm3 Comments

 Listen closely in Kusköy, a mountainous region of northeast Turkey, and you might hear something like this whistled phrase trill across a steep valley. What you hear is not birdsong, but a version of the Turkish language that is whistled instead of spoken, a method that can convey messages across distances of up to 5 kilometers. In kuş dili, or “bird language,” the phrase means “thank you very much” (çok teşekkür ederim in spoken Turkish). Now, a new study shows that the brain processes kuş dili very differently from spoken Turkish, a finding that challenges conventional wisdom about how language works in the brain. The research could also have implications for stroke victims suffering from language loss. 

One of a handful of whistled languages throughout the world, whistled Turkish is still Turkish—it has the same words and the same grammatical structure—but it has a different physical form. A whistle replaces the voice, just as written words replace speech in languages around the world, says bioacoustician and linguist Julien Meyer, at France's National Center for Scientific Research in Bron, France, who was not involved in the new study. People who use kuş dili speak ordinary Turkish as well; the whistled version probably arose as a way for villagers to stay in touch when they were far apart.

 

In general, the brain’s left hemisphere plays a far more active role than the right in processing language, whether spoken, written, or signed, says study author and biopsychologist Onur Güntürkün of the Institut of Cognitive Neuroscience in Bochum, Germany. Because whistled languages use melody to convey their meaning, however, Güntürkün and others wondered whether the right hemisphere, which processes melodic tones, might play a larger role than normal.

To explore that hypothesis, Güntürkün and colleagues put a new twist on a classic test, they report today in Current Biology. In the original experiment, researchers feed two slightly different syllables, such as “ba,” and “da,” into subjects’ right and left ears at precisely the same time, using headphones. Then, they ask the participants to say which syllable they’re hearing.

If “ba” is being piped into the right ear, most people will hear “ba” instead of “da,” Güntürkün says. That’s because auditory nerves in the right ear shuttle signals to the left side of the brain and its language-processing centers, whereas nerves in the left ear carry signals to the right side of the brain before relaying them back to the left hemisphere. When a signal from the left ear finally arrives at its final destination, the left hemisphere is already busy processing the right ear’s speech sound, Güntürkün says. Throughout the experiment, participants are “completely unaware” that they are hearing different signals, he adds.

To see whether the brain processes whistled language in a similar fashion, the team repeated the experiment by playing syllables of kuş dili for native whistlers. All showed left-hemisphere dominance for spoken Turkish. But when the team fed whistled Turkish syllables into the headphones, the two hemispheres became “balanced,” with subjects identifying syllables from the left and right ears with roughly equal frequency. That suggests that the right hemisphere plays a larger role in comprehending whistled languages than in spoken ones, Güntürkün says.

Precisely why the asymmetry normally seen in language processing seems to vanish is “still open to debate,” Meyer says. But the results, he says, are convincing.

The findings could inform treatments for people who have suffered from language loss after a stroke, Güntürkün says. People who lose their speech after a left hemispheric stroke can sometimes learn to sing their words. Similarly, Güntürkün says, “I would expect that people with a left hemispheric stroke could still use whistled Turkish.”

But that will require further studies of kuş dili users, whose numbers—now at roughly 10,000—are dwindling rapidly as cell phones oust whistling as the main method of long-distance communication. One reason whistled Turkish is disappearing? “You can gossip with a mobile phone, but you can’t do that with whistling because the whole valley hears,” Güntürkün says.

The Science & Education team's insight:

A fascinating piece of research and beautifully presented with video and audio clips and clear explanation.

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When The Media Get It Wrong

When The Media Get It Wrong | Communicating Science | Scoop.it
I was on the verge of spluttering my muesli across the living room all because of a report spewing from the ABC Breakfast program. “New research challenges Darwinian Evolution” is probably not a phrase that would invoke reflux in most people but to an evolutionary biologist and professional science communicator, that simple phrase caused my bile to boil. And my outrage was fuelled by comments about ‘random evolution’. I smelt a piece of reporting on some scientific research that had missed the point and perpetrated a few myths in the process – all the hallmarks of a non-specialist reporter trying to tackle a story out of their depth.

But, when I looked into the incident, I was surprised to find a variety of other factors that had all contributed to the near loss of my breakfast. Herein lays a cautionary tale for science communicators and reporters, researchers intent on taking their stories to the media and a plea for specialist reporters.

At the centre of this saga is a very interesting paper where researchers have reconstructed the abundance of trace elements in the world’s oceans over the last 700 million years. The paper went on to draw a correlation between trace element concentration and various tectonic events over that period of time (as mountain chains rise and erode there is an increase in supply of trace elements and a subsequent decrease when the Earth’s crust is more quiescent). And lastly a link was made between the supply of trace elements and the history of life, what can be thought of as The Fertilizer Effect: during periods of high trace element concentrations, life blossoms but some periods of low trace element supply are correlated with extinction events. It’s a good story that’s been emerging gradually over the last few years.

But the original ABC report claimed this research ‘challenged’ Darwinian Evolution and suggested that evolution was thought to be random. Not only are these terms red rags to this old bull (as I explain below), it was quite obvious that this research did not match this news report.

Getting onto social media, it was apparent that I was not the only one who had picked up on these errors and was seriously offended by them. As the day progressed the on-line report changed.

The Science & Education team's insight:

Here are relevant articles, starting with Paul’s article from the RIA

http://riaus.org.au/articles/when-the-media-get-it-wrong/

Then the modified news report

http://www.abc.net.au/news/2015-07-09/researchers-challenge-darwins-theory-of-evolution/6607706

The press release which stimulated it

http://www.utas.edu.au/latest-news/utas-homepage-news/evolution-driven-by-regular-collision-of-continents,-research-finds

A better article from the Conversation

https://theconversation.com/plate-tectonics-may-have-driven-the-evolution-of-life-on-earth-44571

and the original article (if you are a Deakin person)

http://ezproxy.deakin.edu.au/login?url=http://www.sciencedirect.com/science/article/pii/S1342937X15001537

or not

http://www.sciencedirect.com/science/article/pii/S1342937X15001537

A couple of minor comments on this good case study of science reporting:

It was an interesting piece of research and I am glad that Paul’s article alerted me to it.The Conversation article was more accurate and informative but that is because it was written by scientists for a sophisticated audience. Selina Ross’ article was written by a working journalist for the general public and this gets me to the heart of my article.It is unrealistic to expect the employment of more science journalists or that journalists will get the scientists to check the articles before they go to press. As most publishing and information is online, what we can expect, and need to ensure is the standard, is what happened, to some extent, in this case: when incorrect or misleading information is published then activists and experts, such as ourselves, talk to the journalists and improve the copy.One quibble I would have is the use of the phrase “laser technology” (Conversation) and “They used lasers on the samples” (ABC): they used a mass spectrometer, admittedly “Laser Ablation-Inductively Coupled Plasma Mass Spectrometry” (original paper) but still it is the ratio of mass to charge which is at the heart of the measurement although getting the ions is much more sophisticated and I am glad that my quibble got me to investigate LA-ICP-MS.It is interesting that the press release was not the source of any of the misdirection, as against the BMJ report from last year: Sumner, P., Vivian-Griffiths, S., Boivin, J., Williams, A., Venetis, C. A., Davies, A., . . . Chambers, C. D. (2014). The association between exaggeration in health related science news and academic press releases: retrospective observational study. British Medical Journal, 349(7015). doi: 10.1136/bmj.g7015Thanks Paul for stimulating an important discussion
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Photo unrealism: seeing birds differently

Photo unrealism: seeing birds differently | Communicating Science | Scoop.it
National Geographic Photo Blog
The Science & Education team's insight:

A really interesting use of digital photography to add extra information.

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Monitoring a Waking Black Hole

Monitoring a Waking Black Hole | Communicating Science | Scoop.it
NASA's Swift satellite detected a rising tide of high-energy X-rays from the constellation Cygnus on June 15, just before 2:23 p.m. EDT.

 

An X-ray nova is a bright, short-lived X-ray source that reaches peak intensity in a few days and then fades out over a period of weeks or months. The outburst occurs when stored gas abruptly rushes toward a neutron star or black hole. By studying the patterns of the X-rays produced, astronomers can determine the kind of object at the heart of the eruption.

"Relative to the lifetime of space observatories, these black hole eruptions are quite rare," said Neil Gehrels, Swift's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "So when we see one of them flare up, we try to throw everything we have at it, monitoring across the spectrum, from radio waves to gamma rays."

Astronomers classify this type of system as a low-mass X-ray binary. In V404 Cygni, a star slightly smaller than the sun orbits a black hole 10 times its mass in only 6.5 days. The close orbit and strong gravity of the black hole produce tidal forces that pull a stream of gas from its partner. The gas travels to a storage disk around the black hole and heats up to millions of degrees, producing a steady stream of X-rays as it falls inward.

But the disk flips between two dramatically different conditions. In its cooler state, the gas resists inward flow and just collects in the outer part of the disk like water behind a dam. Inevitably the build-up of gas overwhelms the dam, and a tsunami of hot bright gas rushes toward the black hole.

Astronomers relish the opportunity to collect simultaneous multiwavelength data on black hole binaries, especially one as close as V404 Cygni. In 1938 and 1956, astronomers caught V404 Cygni undergoing outbursts in visible light. During its eruption in 1989, the system was observed by Ginga, an X-ray satellite operated by Japan, and instruments aboard Russia's Mir space station.

"Right now, V404 Cygni shows exceptional variation at all wavelengths, offering us a rare chance to add to this unique data set," said Eleonora Troja, a Swift team member at Goddard.

Ongoing or planned satellite observations of the outburst involve NASA’s Swift satellite, Chandra X-ray Observatory and Fermi Gamma-ray Space Telescope, as well as Japan’s MAXI, the European Space Agency's INTEGRAL satellite, and the Italian Space Agency's AGILE gamma-ray mission. Ground-based facilities following the eruption include the 10.4-meter Gran Telescopio Canarias operated by Spain in the Canary Islands, the University of Leicester's 0.5-meter telescope in Oadby, U.K., the Nasu radio telescope at Waseda University in Japan, and amateur observatories.

V404 Cygni has flared many times since the eruption began, with activity ranging from minutes to hours. "It repeatedly becomes the brightest object in the X-ray sky -- up to 50 times brighter than the Crab Nebula, which is normally one of the brightest sources," said Erik Kuulkers, the INTEGRAL project scientist at ESA's European Space Astronomy Centre in Madrid. "It is definitely a 'once in a professional lifetime' opportunity."

In a single week, flares from V404 Cygni generated more than 70 "triggers" of the Gamma-ray Burst Monitor (GBM) aboard Fermi. This is more than five times the number of triggers seen from all objects in the sky in a typical week. The GBM triggers when it detects a gamma-ray flare, then it sends numerous emails containing increasingly refined information about the event to scientists on duty.

Every time the GBM recovered from one trigger, V404 Cygni set it off again, resulting in a torrent of emails. The event prompted David Yu, a GBM scientist at the Max Planck Institute of Extraterrestrial Physics in Garching, Germany, to comment on social media: "Achievement Unlocked: Mailbox spammed by a blackhole."

Related Links

Swift detects the V404 Cygni outburst
http://gcn.gsfc.nasa.gov/gcn/gcn3/17929.gcn3

Alert notice from the American Association of Variable Star Observers
www.aavso.org/aavso-alert-notice-520

NASA's Swift Satellite Discovers a New Black Hole in our Galaxy
www.nasa.gov/mission_pages/swift/bursts/new-black-hole.html

The Science & Education team's insight:

Astronomy is a science in which, often, you are dependent on what the universe throws at you. You have to be prepared (and patient).

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The largest flies in the world

The largest flies in the world | Communicating Science | Scoop.it
If you think bluebottles are big flies, think again. Two obscure groups of tropical flies are the giants of the fly world

 

Houseflies are annoying. The buzzing sound they make is infuriating, and they just can't grasp that glass is impossible to fly through even though it's transparent. Noisy and stupid: the worst possible combination.

They're also dangerous, as they carry a host of diseases. All in all, houseflies aren't welcome in our homes.

But they're not the only kind of fly, not by a long shot. The insects we call "flies" belong to a group called the Diptera, which contains at least 110,000 species.

That huge diversity means some flies have become truly spectacular. Two groups, the Mydas flies and timber flies, are in contention for the title of largest flies in the world.

Gauromydas heros, the largest species of Mydas fly (Credit: Natural History Museum)

Mydas flies are technically known as the Mydidae. They are found all around the world, but mostly in hot places with scrub vegetation. There are about 400 species.

The largest species, which is often trotted out as the largest fly in the world, is Gauromydas heros (or sometimes Mydas heros). It has been reported to grow to 7cm long.

However, when Erica McAlister of the Natural History Museum in London, UK measured her specimens, she found they were only about 6cm.

This may be close to the upper size limit for flies, at least with Earth's climate and atmospheric makeup the way it is. According to a 2005 study, ambient temperature sets a limit on the metabolic rate a fly can achieve, and thus on how big it can afford to grow.

An unidentified species of Mydas fly (Credit: biologoandre, CC by 4.0)

We don't know much about Mydas flies' lifestyles.

Adult males have been observed feeding from flowers, perhaps drinking nectar. However, the larvae seem to be predators. G. heros larvae live in or near the ants of leafcutter ants (Atta sp.), where they may feed on the larvae of other insects that are eating the ants' waste.

Male G. heros defend territories centred on the mounds made by the ants. The females lay their eggs there, so a male that controls the area will secure plenty of matings.

The males of another species, Mydas ventralis, are also mildly territorial. They perch on elevated rocks, giving them an excellent view of their surroundings, and fly aggressively at rival males.

An adult timber fly (Pantophthalmus tabaninus) (Credit: PREMAPHOTOS/NPL)

So if the Mydas flies aren't quite as big as has sometimes been reported, what about the timber flies?

They are technically called the Pantophthalmidae. They live in Central and South America, from Mexico in the north to Brazil and Paraguay in the south.

They get their common name because their larvae live in trees. Female timber flies lay their eggs on dying trees, and the larvae drill their way inside. To do this, they have evolved massive mandibles. If there are lots in one tree, they can reportedly be heard munching from several metres away.

They probably feed on the fermenting sap at the heart of the decaying tree, and may remain there for many months while they steadily grow. The wood doesn't contain much nutrition, says McAlister. "Because they eat such awful food, they take ages to develop."

When they eventually emerge as adults, they are giants.

A specimen of a timber fly (Pantophthalmus bellardi) (Credit: Natural History Museum)

"The largest ones we've got are around 8cm head to abdomen," says McAlister, who recently re-examined the Natural History Museum's collection of timber flies. Pantophthalmus bellardi can have a wingspan of 8.5cm. This convincingly trumps the Mydas flies.

The adults only live for a few weeks. They don't seem to eat, and accordingly have under-developed mouthparts. Instead, like many adult insects, they only do one thing: mate and lay eggs.

They don't move much. One study found that P. tabaninus doesn't try to fly unless disturbed. They seem to be quite shy and reclusive, and are hard to find.

In fact, despite their intimidating size the adults are quite harmless.

Male and female timber flies (Pantophthalmidae) (Credit: Natural History Museum)

"They look just like horseflies so they scare the bejesus out of everyone, but they're pathetic," says McAlister. "They just eat wood."

Female timber flies have a long, sharp organ jutting out of their rear ends. "It looks like a massive sting but it's just the female's egg-laying tube," says McAlister.

Rather than having powerful defences, many of them mimic other insects that are more ferocious. They have modelled themselves on tarantula hawk wasps, which famously hunt large spiders such as tarantulas. These are fearsome insects, but the timber flies are nothing of the sort.

The head of a timber fly (Opetiops alienus) (Credit: Natural History Museum)

While the timber flies do seem to be the largest flies in the world, there is one another contender. There is a crane fly or daddy-long-legs known as Holorusia brobdignagius, which has very long legs.

According to the naturalist Mark Carwardine in his book Animal Records, if you stretch out its legs so they are straight they would reach 23cm. It's up to you if you think that counts.

The Science & Education team's insight:

Flies at the upper limit of insect size. The peculiarities of this family of insects are fascinating and this is why we love biology

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AI algorithm learns to ‘see’ features in galaxy images | KurzweilAI

AI algorithm learns to ‘see’ features in galaxy images | KurzweilAI | Communicating Science | Scoop.it
Hubble Space Telescope image of the cluster of galaxies MACS0416.1-2403, one of the Hubble “Frontier Fields” images. Bright yellow “elliptical”

 

A team of astronomers and computer scientists at the University of Hertfordshire have taught a machine to “see” astronomical images, using data from the Hubble Space Telescope Frontier Fields set of images of distant clusters of galaxies that contain several different types of galaxies.

The technique, which uses a form of AI called unsupervised machine learning, allows galaxies to be automatically classified at high speed, something previously done by thousands of human volunteers in projects like Galaxy Zoo.

 

“We have not told the machine what to look for in the images, but instead taught it how to ‘see,’” said graduate student Alex Hocking.

“Our aim is to deploy this tool on the next generation of giant imaging surveys where no human, or even group of humans, could closely inspect every piece of data. But this algorithm has a huge number of applications far beyond astronomy, and investigating these applications will be our next step,” said University of Hertfordshire Royal Society University Research Fellow James Geach, PhD.

The scientists are now looking for collaborators to make use of the technique in applications like medicine, where it could for example help doctors to spot tumors, and in security, to find suspicious items in airport scans.

The Science & Education team's insight:

A nice example of machine learning and worrying for one aspect of citizen science projects.

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Indigenous science: Helping understand the world around us

Indigenous science: Helping understand the world around us | Communicating Science | Scoop.it
Whether it's ancient astronomical observations, restoring biodiversity in Kakadu National Park or using plants as a sustainable building material, Indigenous science continues to contribute to our ...
The Science & Education team's insight:

The photo gallery is where the heart of the message is

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How termite mounds ‘breathe’

How termite mounds ‘breathe’ | Communicating Science | Scoop.it
Changes in temperature between day and night ventilates towering structures

For decades, scientists have marveled at the towering mounds some termites construct and wondered how they work. Although it’s now widely believed the 1- to 2-meter-high structures (seen above) help with ventilation—exchanging stale air for fresh in the insect’s hidden nest—the mechanics behind such a system have remained a puzzle. Now, by using thermal imagery and installing tiny air-flow sensors in about two dozen termite (Odontotermes obesus) mounds, scientists think they have solved the mystery. Their investigation revealed that the mounds act like an “external lung,” harnessing the change in temperature as day becomes night to drive ventilation. Here’s how it works: Inside the hill is a large central chimney connected to a system of conduits located in the mound’s thin, flutelike buttresses. During the day, the air in the thin buttresses warms more quickly than the air in the insulated chimney. As a result, the warm air rises, whereas the cooler, chimney air sinks—creating a closed convection cell that drives circulation, not external pressure from wind as had been hypothesized. At night, however, the ventilation system reverses, as the air in the buttresses cools quickly, falling to a temperature below that of the central chimney. The reversal in air flow, in turn, expels the carbon dioxide–rich air—a result of the termites’ metabolism—that builds up in the subterranean nest over the course of the day, the researchers report online this week in the Proceedings of the National Academy of Sciences. Although the scientists only examined one termite species, the ventilation system is likely the same in others with similar mounds. Such insight could inspire developments in passive architecture, which seeks to eliminate the need for active heating and cooling systems in buildings using strategies such as natural ventilation and efficient insulation, the scientists say.  

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A nice piece of research

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Lack of sleep puts you at higher risk for colds

Lack of sleep puts you at higher risk for colds | Communicating Science | Scoop.it
Researchers show sleep deprivation dampens immune response to cold virus

 

Moms and sleep researchers alike have stressed the importance of solid shuteye for years, especially when it comes to fighting off the common cold. Their stance is a sensible one—skimping on sleep weakens the body’s natural defense system, leaving it more vulnerable to viruses. But the connection relied largely on self-reported, subjective surveys—until now. For the first time, a team of scientists reports that they have locked down the link experimentally, showing that sleep-deprived individuals are more than four times more likely to catch a cold than those who are well-rested.

“It’s very nice to see an experiment looking at sleep as an important regulator for specific antiviral immune responses,” says Michael Irwin, a psychoneuroimmunologist at University of California (UC), Los Angeles, who is not involved with the study. “In this particular case, there’s a hard clinical outcome showing [sleep deprivation] and susceptibility to the common cold.”

In a carefully controlled two-part experiment, scientists began by collecting nightly sleep data on 164 healthy individuals for 1 week. Participants were asked to record the times at which they went to bed and woke up. They also wore small watchlike devices that use a technique called wrist actigraphy to monitor movement (much like a Fitbit tracks activity) while they slept. Aric Prather, lead author of the study and a sleep researcher at UC San Francisco, says that he and his colleagues associate the wrist actigraphy data with being awake—if during a reported sleep period, the wrist band records movement, they take that as an indication of wakefulness, and subtract the time spent moving from the hours asleep.

Then came part two: the cold infections. Scientists quarantined participants in a hotel and gave them nose drops containing rhinovirus—the virus responsible for the common cold. They then closed off the hotel floor for 5 days, letting the hosts’ immune system do the rest. To ensure the most accurate results, researchers drew participants’ blood before the viral exposure to test for levels of rhinovirus antibody, a defensive agent in the immune system that recognizes and attacks rhinovirus. If they found high, preexisting levels of the protective protein, they removed the participant from the study so that prior immunity would not bias the infection rates of the group.

In order to officially register as “sick,” participants had to exhibit one “objective sign of illness” and one other immune response. Signs of illness revolved around mucus production. After viral exposure, scientists collected used tissues daily and, essentially, weighed the snot. Ten grams or more counted as a sign of illness. They also looked at congestion. The researchers dripped a harmless dye into participants’ noses and waited to see how long it took to reach the back of their throats; longer than 35 minutes tallied as a sign of illness. A valid immune response required one of two things: A mucus sample flushed from a participant’s nasal passage had to show signs of viral replication or blood work needed to show new levels of the rhinovirus-fighting antibody.

 

Of the 164 participants, 124 received the actual virus instead of the control, and 48 of them got sick. By checking the sleep duration of the sick participants, researchers report in the current issue of SLEEP that individuals who slept fewer than 5 hours a night were 4.5 times more likely to get sick than those who slept 7 hours or more. Those who slept 5 to 6 hours were 4.2 times more likely to get sick, but those who slept 6 to 7 hours per night were at no greater risk of catching the cold than those who slept 7 hours or more, suggesting that there’s a sleep threshold for potent immune defense.

“Sleep often takes a back seat to other health behaviors like nutrition and exercise,” Prather says. “I think this [experiment] provides some really clear evidence for those people who get less than 5 or 6 hours of sleep—there really is a clear biological cost.”

The Science & Education team's insight:

I think I am gong to bed

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An example of Academic Fraud

An example of Academic Fraud | Communicating Science | Scoop.it
Diederik Stapel, a Dutch social psychologist, perpetrated an audacious academic fraud by making up studies that told the world what it wanted to hear about human nature.
The Science & Education team's insight:

 

An old story but very well told. It is worth quoting the report of the university investigation:

 

"The field of psychology was indicted, too, with a finding that Stapel’s fraud went undetected for so long because of “a general culture of careless, selective and uncritical handling of research and data.” If Stapel was solely to blame for making stuff up, the report stated, his peers, journal editors and reviewers of the field’s top journals were to blame for letting him get away with it. The committees identified several practices as “sloppy science” — misuse of statistics, ignoring of data that do not conform to a desired hypothesis and the pursuit of a compelling story no matter how scientifically unsupported it may be. ... Fraud like Stapel’s — brazen and careless in hindsight — might represent a lesser threat to the integrity of science than the massaging of data and selective reporting of experiments. The young professor who backed the two student whistle-blowers told me that tweaking results — like stopping data collection once the results confirm a hypothesis — is a common practice. “I could certainly see that if you do it in more subtle ways, it’s more difficult to detect,”"

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Two thirds of psychology experiment not reproducible

Two thirds of psychology experiment not reproducible | Communicating Science | Scoop.it
Of 100 studies published in top-ranking journals in 2008, 75% of social psychology experiments and half of cognitive studies failed the replication test

 

A major investigation into scores of claims made in psychology research journals has delivered a bleak verdict on the state of the science.

An international team of experts repeated 100 experiments published in top psychology journals and found that they could reproduce only 36% of original findings.

The study, which saw 270 scientists repeat experiments on five continents, was launched by psychologists in the US in response to rising concerns over the reliability of psychology research.

 

“There is no doubt that I would have loved for the effects to be more reproducible,” said Brian Nosek, a professor of psychology who led the study at the University of Virgina. “I am disappointed, in the sense that I think we can do better.”

“The key caution that an average reader should take away is any one study is not going to be the last word,” he added. “Science is a process of uncertainty reduction, and no one study is almost ever a definitive result on its own.”

All of the experiments the scientists repeated appeared in top ranking journals in 2008 and fell into two broad categories, namely cognitive and social psychology. Cognitive psychology is concerned with basic operations of the mind, and studies tend to look at areas such as perception, attention and memory. Social psychology looks at more social issues, such as self esteem, identity, prejudice and how people interact.

In the investigation, a whopping 75% of the social psychology experiments were not replicated, meaning that the originally reported findings vanished when other scientists repeated the experiments. Half of the cognitive psychology studies failed the same test. Details are published in the journal Science.

Even when scientists could replicate original findings, the sizes of the effects they found were on average half as big as reported first time around. That could be due to scientists leaving out data that undermined their hypotheses, and by journals accepting only the strongest claims for publication.

Despite the grim findings, Nosek said the results presented an opportunity to understand and fix the problem. “Scepticism is a core part of science and we need to embrace it. If the evidence is tentative, you should be sceptical of your evidence. We should be our own worst critics,” he told the Guardian. One initiative now underway calls for psychologists to submit their research questions and proposed methods to probe them for review before they start their experiments.

John Ioannidis, professor of health research and policy at Stanford University, said the study was impressive and that its results had been eagerly awaited by the scientific community. “Sadly, the picture it paints - a 64% failure rate even among papers published in the best journals in the field - is not very nice about the current status of psychological science in general, and for fields like social psychology it is just devastating,” he said.

But he urged people to focus on the positives. The results, he hopes, will improve research practices in psychology and across the sciences more generally, where similar problems of reproducibility have been found before. In 2005, Ioannidis published a seminal study that explained why most published research findings are false.

Marcus Munafo, a co-author on the study and professor of psychology at Bristol University, said: “I think it’s a problem across the board, because wherever people have looked, they have found similar issues.” In 2013, he published a report with Ioannidis that found serious statistical weaknesses were common in neuroscience studies.

 

Nosek’s study is unlikely to boost morale among psychologists, but the findings simply reflect how science works. In trying to understand how the world works, scientists must ask important questions and take risks in finding ways to try and answer them. Missteps are inevitable if scientists are not being complacent. As Alan Kraut at the Association for Psychological Science puts it: “The only finding that will replicate 100% of the time is likely to be trite, boring and probably already known: yes, dead people can never be taught to read.”

There are many reasons why a study might not replicate. Scientists could use a slightly different method second time around, or perform the experiment under different conditions. They might fail to find the original effect by chance. None of these would negate the original finding. Another possibility is that the original result was a false positive.

Among the experiments that stood up was one that found people are equally adept at recognising pride in faces from different cultures. Another backed up a finding that revealed the brain regions activated when people were given fair offers in a financial game. One study that failed replication claimed that encouraging people to believe there was no such thing as free will made them cheat more.

Munafo said that the problem of poor reproducibility is exacerbated by the way modern science works. “If I want to get promoted or get a grant, I need to be writing lots of papers. But writing lots of papers and doing lots of small experiments isn’t the way to get one really robust right answer,” he said. “What it takes to be a successful academic is not necessarily that well aligned with what it takes to be a good scientist.”

The Science & Education team's insight:

This problem is not confined to psychology

 

For the original article:

http://www.sciencemag.org/content/349/6251/aac4716.full

 

As Mike Cole has pointed out, part of the problem is the failure to consider the context and measures which are not "ecologically valid" but I suspect there is a lot more going on here.

 

Also worth looking at: Ioannidis, J. P. A. (2005). Why Most Published Research Findings Are False. PLoS Med, 2(8), e124. doi: 10.1371/journal.pmed.0020124

http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020124

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‘Superpredator’ humans are hunting other animals out of existence

‘Superpredator’ humans are hunting other animals out of existence | Communicating Science | Scoop.it
People kill other species at up to 14 times the rate of other predators

 

A new study drives home the destructive power of our species. Not only do we kill other animals at much higher rates than other predators, but our ability to bring down larger adults can make it very difficult for some prey populations to recover. This superpredator status may fill our bellies, but it has darker implications. "Any predator capable of exerting such impact will eventually drive its prey to extinction," warns Gerardo Ceballos, an ecologist at the National Autonomous University of Mexico in Mexico City.

It’s happened before. About 14,000 years ago, humans entering North America caused many large species, such as the mammoth, to disappear. And our hunting technologies have only improved since then, particularly when it comes to catching fish. Overfishing is a severe problem in some parts of the world, and a recent report concludes that because of human activity, more than 90 fish species are at risk of extinction.

The new study originated in a casual observation. Thomas Reimchen, an evolutionary ecologist at the University of Victoria in Canada, has spent years studying how predators impact the stickleback fish on an island 130 kilometers off the Canadian Pacific coast. Over the decades he determined that each species never kills more than 2% of the sticklebacks per year and usually attacks juveniles. Yet off that same island, fishermen seemed to be taking a far higher percentage of salmon, mostly adults. The contrast bothered him, so Reimchen and a few former students searched the scientific literature for data on the rate at which humans and other animals were killing other species.

After a decade compiling and analyzing about 300 studies, the team came to some grim conclusions, says Chris Darimont, a conservation scientist also at the University of Victoria who helped lead the study. Humans and other predators—like lions, wolves, and grizzly bears—kill wild herbivores at about the same rate, but humans kill large carnivores at nine times the rate of other predators, Darimont, Reimchen, and their colleagues report today in Science. We kill those carnivores not for food, but for trophies and—sometimes—to eliminate them as competitors, Darimont says. Because they naturally don’t face much predation, they have not evolved ways to successfully avoid humans or reproduce fast enough to make up for human-induced losses.

The Science & Education team's insight:

I like this because it confirms my prejudices: eg the elimination of the Australian and American megafauna at the same time humans arrived.

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Spiders glide to safety

Spiders glide to safety | Communicating Science | Scoop.it
Study is first to demonstrate controlled gliding flight in spiders

 

Living high in the rainforest canopies of South America, selenopid spiders are at constant risk of falling. Because they don’t have wings, scientists had assumed they had little control over their fate. But a new study published online today in the Journal of the Royal Society Interface shows that they might have more than we realized: These arboreal spiders can control their falls, gliding from tree to tree to avoid the dangerous forest floor, just like flying squirrels. But the spiders don’t use webbing between their legs. Instead, they manage to stay aloft because of their wide, flat bodies. To find out just how agile the canopy-dwelling spiders are, the team went to Panama and Peru, where they dropped them from a height and filmed their descent (shown above). They found that 86% of selenopid spiders directed their falls toward nearby tree trunks, rather than simply plummeting to the ground. The researchers also filmed spiders’ movements in a wind tunnel, and found that they opt to fall head first, orienting their front legs to steer them to safety. Although small spiders commonly use a behavior called “ballooning,” in which they use a silk line to catch the wind and carry them to new locations, this is the first time that controlled gliding has been demonstrated in arachnids. Some ants and bristletails can also glide, and the authors say their trajectories are strikingly similar to the spiders, even though they use different techniques. Gliding ants fall backwards and steer with their back legs, while bristletails fall forwards and flex their abdomens for steering.

The Science & Education team's insight:

Mainly an opportunity to show some video but fun research

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The siren song of a sticky plant: trap passing insects, attract predators which eat the insects that are attacking you

The siren song of a sticky plant: trap passing insects, attract predators which eat the insects that are attacking you | Communicating Science | Scoop.it
Many plants provide predatory arthropods with food or shelter. Glandular trichomes entrap insects and may provision predators with insect carrion, though it has not been clear whether this putative benefit functions with natural amounts of carrion, whether plants actively attract insect "tourists", and how common this provisioning system is. We tested the hypothesis that a sticky columbine (Aquilegia eximia: Ranunculaceae) attracts passerby arthropods (a siren song leading them to their demise); that these entrapped arthropods increased predators on the plant; and that these predators reduced damage to the plant. Sticky traps baited with columbine peduncles entrapped more arthropod carrion than unbaited control traps. Predator abundance correlated positively with carrion abundance observationally, and experimental removal of carrion reduced predator numbers. Experimental removal of carrion also increased damage to reproductive structures, likely due to reductions in predator numbers. This indirect defense may be common; we compiled a list of insect-trapping sticky plants which includes over 110 genera in 49 families, suggesting a widespread convergence of this trait, even in non-carnivorous plants. The ubiquity of this trait combined with these experiments suggest that carrion entrapment should be viewed as a common and active process mediated by the plant for indirect defense.The siren song of a sticky plant: columbines provision mutualist arthropods by attracting and killing passerby insects.Eric F. LoPresti, Ian Seth Pearse, Grace K. CharlesEcology doi: http://dx.doi.org/10.1890/15-0342.1
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My title says it all

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Plate tectonics may have driven the evolution of life on Earth

Plate tectonics may have driven the evolution of life on Earth | Communicating Science | Scoop.it
The rise and fall of the essential elements for life could have influenced the way life evolved over many millions of years.

 

When Charles Darwin published his theory of evolution by natural selection in 1859, the world hadn’t even heard of plate tectonics. The notion that continents drifted on molten rock currents deep in the Earth’s mantle was unimaginable.

So it would have come as a shock to Darwin to think the movement of the Earth’s continental plates could have been a major driver of evolutionary change in all life.

In our research, published this month in Gondwana Research, we suggest that the regular collision of tectonic plates over the past 700 million years has been a prime driver of evolutionary change on Earth.

The essentials for life

We used laser technology housed in the Earth Science laboratories at the University of Tasmania to analyse more than 4,000 pyrite grains from seafloor mudstone samples collected from around the globe.

This enabled us to determine how concentrations of trace elements in the oceans have varied over the 700 million years. Trace elements included copper, zinc, phosphorus, cobalt and selenium, which are necessary for nearly all life – from marine phytoplankton through to humans – to function.

The most surprising finding was that there were certain periods in Earth’s history when nutrient trace elements were highly enriched in the oceans, and other periods when levels of these critical trace elements were very low.

The nutrient-rich periods promoted rapid plankton growth in the short term, and this appears to correlate with periods of increased evolutionary change. An example of this is the rapid rise in trace elements preceding the Ediacaran (635 to 542 million years ago) and Cambrian (541 to 485 mya) periods, a time when multicellular animal life took off in a big way.

The Cambrian explosion, around 540 million years ago, is when most major groups of living animals appeared. This corresponds to a time when essential trace elements were peaking in the oceans, thus nutrient levels were very high.

 The Cambrian explosion about 540 million years ago was when all the major living groups (phyla) of animal life appeared. Did a rise in oceanic trace elements initiate this event? Wikia, CC BY-SAClick to enlarge

The nutrient-poor periods caused depletion of plankton and promoted a slow-down in rates of diversification and ultimately could have played a role in three major mass extinction events. These occurred at the end of the Ordovician, Devonian and Triassic periods.

Although several possible explanations are given for these extinctions events, depletion in oceanic trace elements might be another plausible factor. Work is currently underway demonstrating that these events are tied to rapid declines in certain essential trace elements, particularly selenium.

Plate tectonics and nutrient cycles

Nutrients in the oceans ultimately come from weathering and erosion of rocks on the continents. Weathering breaks down the minerals in the rocks and releases the nutrient trace elements, which nourish life. Thus when weathering and erosion rates increase for extended periods, more nutrients are supplied to the oceans.

In the long term of geological history, erosion rates rise dramatically during mountain building events caused by the gradual collision of tectonic plates.

Geologists have known since the 1960s that collisions of tectonic plates lead to the formation of huge mountain ranges. The Himalayas were formed when India, drifting northwards after splitting off from the supercontinent of Gondwana, slammed into Asia and pushed up the Tibetan Plateau. These collisions are called called orogenic events and their timing through Earth’s history is now well established.

Continued erosion eventually depletes the surface of nutrients, causing a drop in the ocean’s nutrients. This might have lead to extinction events in the seas.

When tectonic plates collide, mountains are pushed upwards and erosion causes an increase in nutrients in the oceans. Ross Large, University of Tasmania, Author providedClick to enlarge

This is the first time nutrient trace element curves have been developed that demonstrate the relationship between tectonic collisions and the generation of cycles of nutrients.

While the link between these nutrient cycles as drivers of evolution and factors in mass extinction events remains to be proven, it really makes us think about evolution in a broad sense. Plate tectonics and evolution both operate on the same time scale of millions of years, and it seems logical that they could be causally related.

The relationship between increased nutrients in the oceans with bursts of evolutionary change are clearly correlated for the early part of the cycles, but less clear is the correlation with the evolution of advanced land animals.

Life out of the oceans

The origin of the first land animals, tetrapods about 370 million years ago, corresponds with a decrease in oceanic nutrients and a series of mass extinction events in the oceans. This could explain why certain sarcopterygian fishes with robust limbs left the seas when they did in order to leave the nutrient-poor ocean and make out on land.

But the first appearance of dinosaurs and mammals in the early Triassic, about 225 million years ago, has no correlation with trace element abundance.

Perhaps the cycles pertain mainly to biodiversity in the oceans. There is certainly a close correlation with the drop in nutrients and some global oceanic mass extinctions. These events are being tested and explored further in further research on selenium, to be released soon.

 

The Science & Education team's insight:

It is an exciting time in the investigation of the drivers (and retarders) of evolution with new mechanisms coming up all the time. It will be interesting to put them all together and assess the relative importance.

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What children think about Pluto

As the world's greatest scientists and engineers wait to hear from the New Horizons mission, we asked Australia's young scientists to tell us what they think...
The Science & Education team's insight:

It is easy to get children enthusiastic about science. Why do we fail so often?

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Pseudoscience: Using Scientology as an example

Scientology is supposed to be the "science of certainty" but how much science is really there? L. Ron Hubbard was a con man and he used pseudoscience to convince his gullible and uninformed followers that he was a scientific genius who knew more about physics, molecular phenomena, biology and physiology than any actual trained professional, despite the fact that Hubbard not only had no formal education in these subjects but in fact had flunked out of high school and college. Here I break down the pseudoscience behind the dangerous Purification Rundown, a drug detox program the Church of Scientology offers to this day.

You can find out more at my blog, http://mncriticalthinking.com.

The Science & Education team's insight:

A lecture on Scientology's detox claims which is a good, if pedestrian example of debunking pseudoscience.

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What lives here? DNA sequencing analysis shows what lives in a stream of water

What lives here? DNA sequencing analysis shows what lives in a stream of water | Communicating Science | Scoop.it

Industry, agriculture and human settlement put a strain on bodies of water; some organisms cannot survive due to the changing conditions in streams and rivers. Accordingly, their existence sheds light on the quality of the habitat. However, the number of experts able to identify the small animals on the basis of their appearance is in decline; only a few junior researchers are active in this field. RUB researchers from the Department Animal Ecology, Evolution and Biodiversity help preserve expert knowledge.

 

Database with "DNA barcodes"

For this purpose, they are creating a database in collaboration with the "German Barcode of Life Project": in the first step, qualified experts identify the water organisms based on their appearance. Subsequently, a short characteristic segment of the animals' genome – i.e. the barcode – is decoded and fed into the database. Someone who wishes to find out which species are represented in a body of water, takes a water sample, sequences the DNA of the organisms contained therein and matches it against the database. Vasco Elbrecht and Dr Florian Leese have developed an innovative lab protocol which renders this so-called DNA barcoding much faster than hitherto. They are able to identify more than thousand animals within a week after taking the sample. Even now in the development stage, the method identifies more than 80 per cent of the species correctly. It is thus more reliable than species identification based on external characteristics, and the biologists from Bochum are convinced that they will optimise the quota in the near future.

 

Assessment systems have to be adjusted to the new method

In their study, the Bochum-based biologists have also demonstrated the limitations of DNA barcoding. Using this method, it cannot be determined how many individuals of a certain species can be found in a body of water. The established assessment criteria for water quality, on the other hand, do include such data. "This is a problem for available assessment systems," says Florian Leese. "However, running waters are very dynamic; the frequency of species varies strongly for natural reasons over time. Therefore, it makes sense to record the quality based on conclusive species lists, without focusing too much on frequency.”

 

V. Elbrecht, F. Leese (2015): Can DNA-based ecosystem assessments quantify species abundance? Testing primer bias and biomass - sequence relationships with an innovative metabarcoding protocol,

 

PLOS ONE, DOI: 10.1371/journal.pone.0130324, http://dx.plos.org/10.1371/journal.pone.0130324


Via Dr. Stefan Gruenwald
The Science & Education team's insight:

Again, a good example of how, as Floridi terms it, second generation ICT is transforming our work.

 

Floridi, L. (2014). The 4th revolution. Oxford: Oxford University Press.

 

... and I can also recommend Stefan Gruenwald's 'Amazing Science' scoop.it feed.

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The secret of great drumming is in the mathematics

The secret of great drumming is in the mathematics | Communicating Science | Scoop.it
Slight variations in tempo and loudness follow fractal patterns

 

People have long known that professional musicians don’t keep time with the dogged precision of a metronome. However, in deviating from a perfectly steady beat, one professional drummer makes patterns in his timing and loudness that have a particular mathematical form—a fractal—a new study shows. Previous research has shown that the fractal nature of time deviations makes music sound distinctly human.

A fractal is a pattern that looks "self-similar" on many different scales. For example, statistically, a coastline may look just as jagged on the scale of 10 kilometers as it does on the scale of 1000 kilometers. Fractals can emerge in temporal patterns, too, and researchers have observed rhythmic fractal patterns in many controlled musical experiments. Such work sheds light on the unique signatures that musicians impart into their work, and it could help researchers make the rhythmically perfect music generated by computers and drum machines sound more human.

Holger Hennig, a physicist at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, and colleagues decided to analyze the technique of prolific drummer Jeff Porcaro, one of the more famous musicians most people have never heard of. For more than a decade he drummed for the band Toto, and as a session musician he kept time for an extensive list of musical icons including Pink Floyd, Steely Dan, Michael Jackson, and Madonna. Porcaro died of a heart attack in 1992. Hennig and his colleagues chose to study Porcaro’s technique because the paper’s lead author, physicist Esa Räsänen of the Tampere University of Technology in Finland, is himself a drummer and admires Porcaro’s work.

As a representative sample of Porcaro’s timekeeping skills, the research team focused on the studio recording of the 1982 hit “I Keep Forgettin’ ” by singer Michael McDonald. The rapid, high-pitched tink-tink-tink-tink keeping the beat is the hi-hat, a clamshell arrangement of two small cymbals that a drummer opens and closes with a foot pedal and simultaneously strikes with a drumstick. With one hand, Porcaro hit the hi-hat four times on every beat, in subbeats known as sixteenth notes, and motored out almost 400 of them in every minute of the song.

To the listener, the tinks sound flawlessly steady. But Hennig knew that the fractallike deviations he’d observed in previous studies were imperceptible to the human ear, and he wondered whether Porcaro’s rhythm would obey the same mathematical laws. He was also curious about what he’d find if he analyzed the volumes of the tinks, which Porcaro clearly modulates. So Hennig and his team pored over the 1982 recording and statistically analyzed the onset times, interbeat intervals, and amplitudes of Porcaro’s sixteenth notes.

Both the intervals between sixteenth notes and their volumes wavered throughout the piece. Moreover, those variations were similar on time scales ranging from a few seconds to the length of the entire song (3 minutes and 39 seconds), showing that the pattern formed fractals, the researchers reported on 3 June in PLOS ONE. “It seems that the timekeeper in the brain not only produces fractal timing,” Hennig says, “but likely also fractal intensity or, in this case, loudness.”

Psychologist Edward Large, director of the Music Dynamics Laboratory at the University of Connecticut, Storrs, who was not involved in the study, agrees that the fractal patterns Hennig’s team discovered in amplitude are exciting. “That, in a way, is the stronger analysis in this particular paper,” he says.

What’s more, timing and volume varied independently, so that the fractals formed by each were different. That observation surprised and enticed Large. “If most of my colleagues had seen that [loudness and timing] were highly correlated, they would have said, ‘of course,’” Large says, because musicians tend to play faster music louder, and vice versa. But instead, “there’s some independent control going on that’s really subtle.”

Hennig plans to continue studying rhythmic patterns found in recorded music and produced by multiple players. That work should help him hone a computer algorithm he developed to introduce “humanizing” imperfections into computer-generated music. His software is already being used by electronic musician James Holden and many other recording artists.

Hennig doesn’t feel that his work demystifies a raw human art form. In fact, he thinks the study shows how beautiful and mysterious the human brain can be. “I would say that we are totally unpredictable and somewhat predictable at the same time,” he says. “But on top of that, we expect that there’s some Jeff Porcaro magic in there.”

The Science & Education team's insight:

A riposte to all the drummer jokes

 

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