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Archive for November, 2010
An entire world follows the march of the army ants
Army ants have a reputation as destroyers. As they march through the jungle in battalions several thousand-strong, they supposedly kill all in their path. But this infamy is overblown. There’s no doubting their success as predators, but army ants also bring life wherever they march. They have an entourage of over 550 species that hang around their legions, of which 300 or so depend on the ants for their survival.
Carl and Marian Rettenmeyer spent much of their lives studying army ants. Carl passed away in 2009, but this year, Marian has completed the couple’s masterpiece – a comprehensive catalogue of the animals associated with a single species of army ant Eciton burchellii. Their record is incredible – a menagerie of animals running alongside the columns, tracking them by air, living within the nests and garbage dumps, and even riding on the ants themselves.
The dark side of oxytocin, much more than just a “love hormone”
There’s a chemical that can subtly shift your childhood memories of your own mother. In some people, it paints mum in a more saintly light, making them remember her as closer and more caring. In others, the chemical has a darker influence, casting mum as a less caring and more distant parent.
All of this becomes heavily ironic when you consider that the chemical in question – a hormone called oxytocin – is often billed as the “hormone of love”, and even marketed as “Liquid Trust”. As a new study shows, the reality is much more complicated. Describing oxytocin as the “hormone of love” is like describing a computer as a “writing tool” – it does other things too, some of which aren’t pleasant.
I've got your missing links right here – 27th November 2010
Top ten picks
Piece of the week: “In the eery silence that followed Mary Stastch quietly strangled her infant.” Eric Michael Johnson has a superb piece in Scientific American on why mothers kill their kids. David Dobbs has an insightful reply too.
Coolest story of the week: here’s a guy who uses electric fish to make music. The best bit about this is that it was posted at Discover’s Science Not Fiction blog, just hours after I posted my piece on electric fish. And my post was about convergence, where two species evolve the same traits independently of one another!
Strange deaths have been linked to unregulated stem-cell therapies. “The latest cases highlight the difficulty of policing these therapies or determining their safety, because some companies are setting up operations around the globe, taking advantage of loopholes in other countries’ regulations.” Awesome story by David Cyranoski at Nature.
The Rock Stars of Science campaign in GQ has launched a flurry of controversy. Martin Robbins isn’t happy, saying that “if you have to resort to rockstars make science cool, you’re really not very good at communicating science.” SciCurious weighs in and brings some cheerleaders into the mix too. “Rather, it’s because, to make science cool, you can’t just associate scientists with cool or popular things, like cheerleaders or rock stars. You have to make it cool to DO SCIENCE.” Chris Mooney hit back with a great retort of his own (“To which the American public responds “!#$@^ you, I liked The Da Vinci Code” and returns to watching Dancing With the Stars.”) Gimpy has a sharp analysis of GQ’s demographics: “making science cool to educated, white men with high incomes.” And I probably like John Pavlus’s comment best of all.
The Houdini fly inflates head to break walls. It breaks down barriers! And has an inflated head! It’s like a blogger, only it breaks down barriers!
Carl Zimmer pens a wonderful portrait of Columbia’s virus-hunter Ian Lipkin in the NYT
It’s a bird! It’s a plane! No it’s a.. FLYING SNAKE! They don’t need planes…
A major trial shows that men can reduce their risk of HIV infection by taking routine doses of AIDS treatment drugs. Maggie Fox at Reuters has a good write-up and FAQ. Maryn McKenna has an excellent analysis with important caveats, and the New England Journal of Medicine has a thorough comment piece
Flashers lit by bacteria flashes. This art installation has shots of naked people photographed by light of luminous bacteria
“It is proposed that happiness be classified as a psychiatric disorder: Major affective disorder, pleasant type” This is satire, but brilliantly so.
15-minute writing exercise closes the gender gap in university-level physics
Think about the things that are important to you. Perhaps you care about creativity, family relationships, your career, or having a sense of humour. Pick two or three of these values and write a few sentences about why they are important to you. You have fifteen minutes. It could change your life.
This simple writing exercise may not seem like anything ground-breaking, but its effects speak for themselves. In a university physics class, Akira Miyake from the University of Colorado used it to close the gap between male and female performance. In the university’s physics course, men typically do better than women but Miyake’s study shows that this has nothing to do with innate ability. With nothing but his fifteen-minute exercise, performed twice at the beginning of the year, he virtually abolished the gender divide and allowed the female physicists to challenge their male peers.
How birds see magnetic fields – an interview with Thorsten Ritz
This is the second of two interviews, to accompany my latest New Scientist feature on how birds sense magnetic fields. Thorsten Ritz was one of two scientists who blew this field of research open in 2000, with a landmark paper that suggested how migrating birds could detect the faint traces of the Earths’ magnetic field. My interview with his partner, Klaus Schulten, is elsewhere on the blog, along with more background on the topic.
These interviews are meant to provide bonus extras to the other freelance writing I do, acting as a home for great material that would otherwise be cut and lost. And Ritz’s interview is great material. He talks eloquently about the science of the magnetic sense but more importantly, he talks about what it’s like to work in this field – the reasons why progress has been slow, the thrill of crossing disciplines, and the feeling of doing “19th-century science”. I’ve edited the transcript for length, but it’s still long – if you read any of it, read that second half (starting from the fourth question).
How birds see magnetic fields – an interview with Klaus Schulten
It’s now winter in Europe and many small birds are well on their way to warmer climes, migrating over large tracts of land in search of better weather. Along the way, they keep their course with a remarkable supersense – the ability to sense magnetic fields.
This sense is known as magnetoreception. It sounds like a party for an X-Men villain, and it’s also the subject of my latest feature, out in this week’s issue of New Scientist. I talk about how birds sense magnetic fields, using a compass in the eye and a map in the beak. I look at why the magnetic sense has been so fiendishly difficult to study and why it has taken five decades to unravel some of its details.
For the full details, you’ll have to read the feature, but this is the quick version: when light enters the eyes of birds, it excites a molecule called cryptochrome, shunting it into a state when it can be affected by the earth’s magnetic field. The upshot is that you can ‘blind’ a bird to magnetic fields by covering its eyes (and sometimes, just the right one). It’s possible that they may even be able to see the fields as patterns overlaid on top of their normal vision.
One of the reasons that magnetoreception is such a tricky topic (for scientists as well as science writers!) is that it straddles incredible diverse fields of research, including quantum physics, neuroscience and animal behaviour. Only a few scientists can bridge such divides, and I had the pleasure of interviewing two of them for my piece: Klaus Schulten and Thorsten Ritz. Both gave eloquent, insightful and funny interviews that were inevitably pared down into a few short quotes for the feature. Fortunately, I have all the space I need to make that material publicly available.
First up is Schulten, who talks with marvellous clarity about the early days of the research and where it expects it to go. He was warm and jovial, and gave a great insight into how discoveries are made – by connecting dots that no one else can see. I’ve edited it very gently for length, but the words are all his.
On jargon, and why it matters in science writing
Whenever I compile my list of weekly links, I usually end up with more articles from mainstream news sources than I do from science blogs. When I do link to blogs, I tend to go with those written by professional journalists and science writers than those written by scientists. That’s not a reflection on the quality of their writing. I do it simply because I write this blog for a general audience and I want to direct them to material of a similar type. And a lot of science blogs can be far too opaque for the average reader.
There is much talk of blogs being part of a golden age of science writing, where learned people can talk directly to large audiences. I certainly believe this, but I see jargon as one of the biggest barriers in the way. Many blogs fall into the trappings of scientific writing: passive voice, laboured constructions, and roundabout sentences (see this wonderful list for translations of the most common offenders).
And then, there are the words themselves. Some are technical, others are simple words clothed in extra syllables (“armamentarium” anyone?) Every field has its own list; they can be so familiar that it beggars belief that people could not understand them. Skeptical bloggers throw about terms like RCT and placebo, and catchphrases like “correlation is not causality”, as if everyone knows what they mean. Technological writers casually speak of visualisations, infographics and crowdsourcing. Have a look at Carl Zimmer’s famous list of “banned words” for more examples.
Meet the squidworm: half-worm, half-squid… er, actually all-worm
Some scientific discoveries are exciting because they have the potential to save lives and revolutionise the way we live. Others are exciting because they fundamentally change the way we view ourselves and the world around us. And others are exciting because they involve a worm with tentacles on its head.
This is the third kind of discovery.
The squidworm looks like a fusion animal, half-squid and half-worm. In fact, it’s all worm, a member of the group that includes familiar earthworms and leeches. It just happens to have ten long tentacles on its head.
The tentacles are elastic and extendable, and they can be longer than the squidworm’s ten-centimetre body. Two of them – the yellower ones – are used for feeding. The other eight are used to breathe, or possibly to feel its way around. Its head also carries two feathery, brush-like structures called ‘nuchal organs’ that act like a nose, picking up chemical smells in the water.
It’s formal name – Teuthidodrilus samae – means squidworm of the Sama, the people who live in the local Philippine islands. “The name was suggested by the Philippino collaborators that took part in the expedition that discovered the animal,“ says Karen Osborn from the Scripps Institution of Oceanography, who first discovered the worm in 2007. Using remote-controlled submarines, Osborn explored the depths of the western Celebes Sea off the eastern coast of Borneo.
Osborn announced the squidworm’s existence last year (although it hadn’t been formally described then). The animal made its debut alongside six other species of deep-sea worms that it’s closely related to. Four of these are ‘bomber’worms – they release glowing fluid-filled capsules from their heads, probably as decoys to draw the attention of predators.
The squidworm has no such defence and it doesn’t seem to be a very strong swimmer either. Like the bomber worms, its flanks are lined by rows of bristled oars that beat in hypnotic waves. But unlike the bombers, the squidworm has a more leisurely pace. It’s certainly no predator; instead, Osborn thinks that it filters food from the bits of matter that sink down from the upper ocean.
Over seven dives, Osborn found 17 of these distinctive creatures and she expects to find many more. She thinks it’s probably fairly common and other related species will soon be discovered. The fact that such a striking animal has only just been discovered says a lot about our ignorance of the deep sea.
The squidworm lives in one of the richest but most mysterious layers – the demersal zone, just above the ocean floor. It’s the largest habitat on Earth, and a haven for undiscovered life. Here, animals can easily evade collection devices towed along the seafloor, while staying under the reach of mid-water nets dragged overhead. To appreciate the richness of life in these waters, you need special submersibles like the ones that Osborn used, which can move about easily and collect local animals without damaging their frail bodies. Who knows what else the subs will discover?
Reference: Biology Letters http://dx.doi.org/10.1098/rsbl.2010.0923
Related: Marine worms release glowing “bombs” to fool predators
If the citation link isn’t working, read why here
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Two fish families evolved electric powers by tweaking the same gene
The rivers of Africa and South America are full of shocking conversations. Both continents are home to fish that can talk to each other using electric fields: the elephantfishes of Africa, and the knifefishes of South America (including the famous electric eel). Both groups live in dark, murky water where it’s hard to see where you’re swimming. Both have adapted by using electricity to guide their way. Their bodies have become living batteries and their muscles can produce electric currents that help them communicate, hunt, navigate and court.
But both elephantfishes and knifefishes evolved their electric powers independently. Their common ancestors had no such abilities. They are a great example of how two groups of animals, faced with a similar problem, can arrive at the same solution. And this similarity is all the more striking because it is based on the same gene. For a fish, it seems there are only so many ways to be electric.
Fake CVs reveal discrimination against Muslims in French job market
Meet Khadija Diouf. She is 24 years old, she’s single, she lives in France and she has spent the last three years working in secretarial and accounting jobs. Her surname tells us that she’s descended from Senegalese immigrants, and her first name strongly suggests that she’s Muslim. Hundreds of employers across France will have seen Khadija’s name and none of them would have known the most important thing about her: she doesn’t exist.
Khadija is one of three fake women invented by Claire Adida from the University of California, San Diego. They are all part of a clever experiment that reveals how the French job market is rife with discrimination against Muslims. Adida found that in at least two sectors, a Muslim candidate is around 2.5 times less likely to get a job interview than a Christian one, with all else being equal. These results were backed up by a large survey, which showed that among second-generation Senegalese immigrants, Muslim households earn far less than Christian equivalents.
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