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Category Archive: Science

Apr 22 2014

How kinesin actually moves

Horizontal grid lines (dotted lines) are spaced 8 nm apart. Data were median-filtered with a window width of 60 ms. b, Normalized histogram of pairwise distances between all pairs of data points in this record, showing a clear 8-nm periodicity. c, Normalized power spectrum of the data in b, displaying a single prominent peak at the reciprocal of 8 nm (arrow). d, Variance in position, averaged over 28 runs at 2 microM ATP (dots), and line fit over the interval 3.5 ms to 1.1 s. The y-intercept of the fit is determined by equipartition,  left fencex2right fence = kT/alpha, where alpha is the combined stiffness of the optical trap and bead–microtubule linkage. The rapid rise in variance at short times reflects the brownian correlation time for bead position.

Recently, Carl Zimmer made a criticism of the computer animations of molecular events (it’s the same criticism I made 8 years ago): they’re beautiful and they’re informative, but they leave out the critical aspect of stochastic behavior that is important in understanding the biochemistry. He’s talking specifically about kinesin, a transport protein which the animators …

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Apr 22 2014

Got sand in your…?

Do not search for information on getting sand in your genitals. It’s a morass of nonsense out there, with all kinds of bizarre pop culture notions. Most of it seems to be about getting sand in your vagina, which is treated as slogan to mock and trivialize women’s problems, but getting sand under your foreskin…oh, …

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Apr 21 2014

Mary’s Monday Metazoan: Well, I wouldn’t eat it

Australian Geographic

Apr 21 2014

Patterson and Kehoe, and the great lead debate

You know what is really impressing me about Neil deGrasse Tyson’s Cosmos? That he doesn’t hesitate to draw connections between science and how we live our lives — there is an implicit understanding that science has become fundamental to how we see the universe. Last night’s episode was no exception. What started as an explanation …

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Apr 18 2014

Friday Cephalopod: Sparkle magic!

MBARI

Apr 15 2014

Here’s something else oppressing Ken Ham

tiktaaliklimb

He hates Tiktaalik. He hates it so much he even has a hard time spelling its name correctly. Tikaalik is again being popularized through the new PBS series "Your Inner Fish.” it’s really a desperate con job on the part of evolutionists who can’t defend their evolutionary fictional story. He actually surprises me a little …

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Apr 15 2014

Science conspires to make me feel really old now

Virginia Hughes tells us about techniques to look inside the zebrafish brain. The gang at HHMI are using two photon imaging and clever image analysis to get very clear, sharp images of fluorescent neurons. Oy, that’s pretty. This old codger did some of that stuff, many years ago, but you know what we had to …

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Apr 14 2014

Mary’s Monday Metazoan MISANDRY

lemur

That photo is from a lovely new documentary, with this trailer. However, I have to call attention to one troubling fact. “All these lemurs have one thing in common – from the little one to the very largest one – they all have female dominance. The females are the leaders. The females are the ones …

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Apr 14 2014

Years of Living Dangerously

This new documentary on Showtime is pretty good (despite the appearance of Thomas Friedman), and this is the premiere episode. One of the most interesting aspects of the show is that it emphasizes economic issues. The standard tactic of the climate change denialists is to argue that it’s happening, we can’t do anything about it, …

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Apr 14 2014

Fun & games on Reddit

Stephan Lewandowsky, the author of the article that made climate change denialists cry and that was later retracted under pressure from denialists, is doing a Reddit AMA right now. Get in early! Before the kooks flood the questions! (via Greg Laden)

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