By Maggie Koerth-Baker at 11:25 am Tuesday, Oct 25
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I've talked here before about how difficult it is to attribute any individual climactic catastrophe to climate change, particularly in the short term. Patterns and trends can be said to link to a rise in global temperature, which is linked to a rise in greenhouse gas concentrations in the atmosphere. But a heatwave, or a tornado, or a flood? How can you say which would have happened without a rising global temperature, and which wouldn't?
Some German researchers are trying to make that process a little easier, using a computer model and a whole lot of probability power. They published a paper about this method recently, using their system to estimate an 80% likelihood that the 2010 Russian heatwave was the result of climate change. Wired's Brandon Keim explains how the system works:
The new method, described by Rahmstorf and Potsdam geophysicist Dim Coumou in an Oct. 25 Proceedings of the National Academy of Sciences study, relies on a computational approach called Monte Carlo modeling. Named for that city’s famous casinos, it’s a tool for investigating tricky, probabilistic processes involving both defined and random influences: Make a model, run it enough times, and trends emerge.
“If you roll dice only once, it doesn’t tell you anything about probabilities,” said Rahmstorf. “Roll them 100,000 times, and afterwards I can say, on average, how many times I’ll roll a six.”
Rahmstorf and Comou’s “dice” were a simulation made from a century of average July temperatures in Moscow. These provided a baseline temperature trend. Parameters for random variability came from the extent to which each individual July was warmer or cooler than usual.
After running the simulation 100,000 times, “we could see how many times we got an extreme temperature like the one in 2010,” said Rahmstorf. After that, the researchers ran a simulation that didn’t include the warming trend, then compared the results.
“For every five new records observed in the last few years, one would happen without climate change. An additional four happen with climate change,” said Rahmstorf. “There’s an 80 percent probability” that climate change produced the Russian heat wave.
By Maggie Koerth-Baker at 7:41 am Thursday, Sep 22
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A new paper is arguing that epigenetic variation—basically, what happens when an environmental trigger turns genes on and off, or makes them express differently—may not survive over many generations and, thus,
would not have much of an impact on evolution in general. Expect a lot of dissent. This will be an interesting debate and I'm looking forward to seeing how the evidence shakes out over a few more papers.
By Maggie Koerth-Baker at 1:07 pm Tuesday, Sep 20
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A couple of years ago, I told you about Foldit, a computer game that harnesses the power of human putzing to help scientists unravel the mysteries of protein structure. There's a new research paper out that uses results from Foldit as a basis for a new proposed structure of a key protein in a virus that is a relative of HIV.
As important as proteins are, we know relatively little about how and why these complex chains of amino acids fold and twist the way they do and how that structure relates to function. Foldit takes advantage of the fact that, given the right rules, people can come up with possible, plausible protein structures far faster than a computer program can factor out all the possible permutations. And that's why Foldit players—citizen scientists of a sort—were so useful in this case. Ed Yong at Not Exactly Rocket Science explains:
They discovered the structure of a protein belonging to the Mason-Pfizer monkey virus (M-PMV), a close relative of HIV that causes AIDS in monkeys.
These viruses create many of their proteins in one big block. They need to be cut apart, and the viruses use a scissor enzyme –a protease – to do that. Many scientists are trying to find drugs that disable the proteases. If they don’t work, the virus is hobbled – it’s like a mechanic that cannot remove any of her tools from their box.
To disable M-PMV’s protease, we need to know exactly what it looks like. Like real scissors, the proteases come in two halves that need to lock together in order to work. If we knew where the halves joined together, we could create drugs that prevent them from uniting. But until now, scientists have only been able to discern the structure of the two halves together. They have spent more than ten years trying to solve structure of a single isolated half, without any success.
The Foldit players had no such problems. They came up with several answers, one of which was almost close to perfect. In a few days, Khatib had refined their solution to deduce the protein’s final structure, and he has already spotted features that could make attractive targets for new drugs.
“This is the first instance that we are aware of in which online gamers solved a longstanding scientific problem,” writes Khatib. “These results indicate the potential for integrating video games into the real-world scientific process: the ingenuity of game players is a formidable force that, if properly directed, can be used to solve a wide range of scientific problems.”
By Maggie Koerth-Baker at 11:53 am Thursday, Sep 15
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Really interesting new study of 20,000 women suggests that the use of
IUDs might reduce the risk of both major types of cervical cancer, even in women who contracted cancer-causing HPV. The researchers speculate that the IUD's presence—it is, after all, a foreign object in your lady bits—may serve to stimulate immune responses that fight off HPV infection early and prevent it from progressing to cancer. This needs follow up. But it's intriguing.
(Via Colleen McCaffery)
By Maggie Koerth-Baker at 10:44 am Thursday, Aug 18
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Earlier this week, I told you about a new study tracking radioactive fallout from the nuclear power plant disaster in Fukushima, Japan.
It started with a team of researchers in California, who had been monitoring radioactive sulfur in the atmosphere since 2009. Last spring, after an earthquake and tsunami critically damaged several reactors at the Fukushima Daiichi power plant, those researchers watched the levels of radioactive sulfur skyrocket, relatively speaking. The amounts of radioactive sulfur that reached the California coast weren't high enough to be a threat to humans, but they made a big impact on extremely sensitive monitoring equipment.
Using that data, the researchers were able to figure out where the radioactive sulfur came from and back-calculate how much would have been produced at the site of the disaster—information that can tell us something about how dangerous the disaster really was to people living nearby.
But these researchers weren't the first to collect radioactive isotopes from Fukushima on American shores. And they weren't the first to offer up improved estimations of how much radiation leaked from the damaged power plant in the early days of the disaster. I thought this study was interesting. But, like a lot of you, I was left wondering why it was important.
Then yesterday, I interviewed Antra Priyadarshi, the lead author on the peer-reviewed paper that was published about this study. And I realized I'd gotten the story all wrong. This paper is about radioactive sulfur from the Fukushima disaster. But it isn't about the Fukushima disaster. It's not even about nuclear power. Not really.
In reality, this is a paper about coal. And it's important because of what it can tell us about the sort of air pollution that is much more mundane—and more deadly—than the fallout from a single nuclear disaster.
Read the rest
By Maggie Koerth-Baker at 9:30 am Wednesday, Aug 3
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One traditional way to kill a lot of bison: Run them off the edge of a cliff. Now, anthropologists are studying the landing patterns of buffalo at a Montana kill site by recreating the hunt ...
with the help of some old truck tires. (Via Alex Witze)
