Two mice run headfirst into one another in a narrow plastic tube that isn’t wide enough for both of them. One of them must give way. In their earlier encounter, the first mouse exerted its dominance by forcing its rival to reverse down the tube. This time, things are different; the second mouse pulls rank and the first one backs down.
Mouse hierarchies don’t change this readily, but the second mouse has been given a boon by Fei Wang at the Chinese Academy of Science. By injecting a single gene into one part of its brain, Wang turned the subordinate animal into a dominant one.
Twitter is either an indispensible professional and personal tool, or the downfall of humanity, depending on who you believe. But to Scott Golder and Michael Macy from Cornell University, it is something more: an unparalleled source of data. The duo has used the popular social networking site to eavesdrop upon the world’s moods, as they rise and fall throughout the day and across the week. By analysing half a billion tweets from 2.4 million people in 84 different countries, they turned Twitter into a giant global mood ring.
They found that, on average, people wake up in a good mood, which falls away over the course of the day. Positive feelings peak early in the morning and again nearer midnight, while negative feelings peak between 9pm and 3am. Unsurprisingly, people get happier as the week goes on. They’re most positive on Saturdays and Sundays and they tend to lie in for an extra two hours, as shown by the delayed peak in their positive feelings. The United Arab Emirates provide an interesting exception. There, people work from Sunday to Thursday, and their tweets are most positive on Friday and Saturday.
Folks, the Open Laboratory – a yearly anthology of the best of the science blogging world – is closing for submissions on Monday. If any of you wanted to nominate any of my posts for the anthology, I’d be very grateful. Here’s the submission form, and the full list of posts to jog your memory.
I’ve got a new piece in Nature News about a cool new technique that uses glowing bacteria to send encrypted messages. There’s lots to like about this: they call the technique SPAM, they reference Mission Impossible in the paper, and the whole thing is actually funded by DARPA (the US Defense Advanced Research Projects Agency).
But most importantly of all, it allowed me to get Godwin’s Law into Nature (3rd paragraph from bottom). Thanks Meredith L Patterson!
From the piece (do read the full one):
For millennia, people have written secret messages in invisible ink, which could only be read under certain lights or after developing with certain chemicals. Now, scientists have come up with a way of encoding messages in the colours of glowing bacteria.
The technique, dubbed steganography by printed arrays of microbes (SPAM), creates messages that can be sent through the post, unlocked with antibiotics and deciphered using simple equipment.
Manuel Palacios, a chemist at Tufts University in Medford Massachusetts, [encrypted] messages using seven strains of Escherichia coli bacteria. Each one was engineered to produce a different fluorescent protein, which glows in a different colour under the right light.
Colonies of bacteria are grown in rows of paired spots, every combination of two colours corresponding to a different letter, digit or symbol. For example, two yellow spots signify a ‘t’, whereas an orange and a green spot denote a ‘d’. Once grown, the pattern of colonies is imprinted onto a nitrocellulose sheet, which is posted in an envelope. The recipient can use the sheet to regrow the bacteria in the same pattern and decipher the message.
Reference: Palacios, Benito-Pena, Manesse, Mazzeo, LaFratta, Whitesides & Walt. 2011. InfoBiology by printed arrays of microorganism colonies for timed and on-demand release of messages. PNAS http://dx.doi.org/10.1073/pnas.1109554108
Pop a “miracle berry” into your mouth, and you might wonder if it was named by an overreaching marketing department. The small red fruit tastes of very little – it has a “mildly sweet tang… [like] a less flavorful cranberry”. But it’s not the taste of the fruit itself that matters. To understand why the berry gets its name, you need to eat something acidic. The berries have the ability to make sour foods taste deliciously sweet. Munch one, and you can swig vinegar like it was a milkshake, or bite lemons as if they were candy.
The secret to the fruit’s taste-transforming powers is a protein called miraculin. Now, Ayako Koizumi from the University of Tokyo has discovered just how the protein acts upon our tongues.
If you go down to the woods of California today, you might be in for a big surprise. At night, the forests crawl with sinuous shapes that glow with an eerie greenish-blue colour. They are Motyxia millipedes and they shine brightly whenever they’re disturbed. “If you go to the right forest and you let your eyes get adjusted to the night, then you can see them everywhere,” says Paul Marek from the University of Arizona. Some big oak tress can shelter 1 glowing millipede in every square metre. They look like fields of stars.
There are around 12,000 known species of millipedes, and only the eight Motyxia species glow. Marek says, “[They] would definitely be on my top 10 for my imaginary “millipede biodiversity global tour” (along with the shocking pink millipede in Thailand & the longest millipede in Africa).”
But why do the Californian ones glow? Marek knows the answer. With hundreds of millipedes, some clay, and a bit of paint, he has shown that they light up to ward off predators. You might expect that the light shows would make the millipedes easier to find and eat. In fact, it deters hungry mouths.
My piece on sushi-digesting genes that hitched a ride from ocean bacteria to Japanese guts has been included in this year’s anthology.
I’m honoured for several reasons. The anthology was edited by the incredible father-and-daughter team of Floyd and Rebecca Skloot, she who wrote one of the best science books of last year. It features writing from some of the best in the business like Carl Zimmer and Deborah Blum. And I’m proud to represent the fine world of science blogging in an anthology that’s traditionally dominated by mainstream publications; this is actually the first time a blog has been included. Represent!
My only regret is that my attempt to sneak “favourite” into an American book was foiled by an eagle-eyed editor.
During its lifetime, a frog will snap up thousands of insects with its sticky, extendable tongue. But if it tries to eat an Epomis beetle, it’s more likely to become a meal than to get one. These Middle Eastern beetles include two species – Epomis circumscriptus and Epomis dejeani – that specialise at killing frogs, salamanders, and other amphibians.
Their larvae eat nothing else, and they have an almost 100 percent success rate. They lure their prey, encouraging them to approach and strike. When the sticky tongue lashes out, the larva dodges and latches onto its attacker with wicked double-hooked jaws. Hanging on, it eats its prey alive. The adult beetle has a more varied diet but it’s no less adept at hunting amphibians. It hops onto its victim’s back and delivers a surgical bite that paralyses the amphibian, giving the beetle time to eat at its leisure.
Tak-Sing Wong from Harvard University has created a synthetic material so slippery that it makes a duck’s back look like a sponge. It is “omniphobic” – it repels everything. All manner of liquids, from water to blood to crude oil, roll straight off it. Ice cannot form on it. It even heals itself when damaged. It’s an extraordinary material and it was inspired by the lips of a flesh-eating plant.