Was Alan Turing right about the mechanism behind tiger stripes?

https://simonsfoundation.org/features/science-news/biologists-home-in-on-turing-patterns/

by nature24 • 13 years ago

106 24 13 years ago

simonsfoundation.org

blauwbilgorgel2• 13 years ago

You can generate your own Turing patterns with OpenCV.

Watching them slowly change and with different parameters can be very mesmerizing:

Video: http://www.youtube.com/watch?v=KKwbDKRKG7k multiscale turing pattern (python+opencv)

Code (Python): https://code.ros.org/trac/opencv/browser/trunk/opencv/sample...

Paper: http://www.jonathanmccabe.com/Cyclic_Symmetric_Multi-Scale_T...

goostavos• 13 years ago

Wow, that is awesome!

I spent the past weekend tying to wrap my head around OpenCV. After 3 days of bagging my head against the wall trying to get template matching to work, I determined that I am not yet smart enough for computer vision. The domain knowledge required seems to be very deep.

So, seeing the cool things people do with the library is inspirational, (but also makes me incredibly jealous).

femto2• 13 years ago

Have you looked at the book "Learning OpenCV", by Bradski and Kaehler, published by O'Reilly? I haven't done much work with OpenCV, but I have read the entire book and it seemed to be a good introduction. A companion collection of examples is available online, consisting of a set of programs that can be compiled and used as a starting point for further hacking. A Google search on the title, happens to yield a link to the full text.

skore• 13 years ago

That video also seems to be a pretty good way to demonstrate the limits of lossy video encoding.

blauwbilgorgel2• 13 years ago

These are a little sharper: http://vimeo.com/58321857 http://www.youtube.com/watch?v=sCJjvqjyCCg (720p)

Demo Turing pattern-like fluid in WebGL: http://cake23.de/turing-fluid.html

kingkawn2• 13 years ago

No mention of recent developments in biology related to pattern expression or the older idea of heterozygous genetic expression:

The Notch signaling pathway: http://en.wikipedia.org/wiki/Notch_signaling_pathway

Heterozygous genetic expresson: http://en.wikipedia.org/wiki/Calico_cat http://en.wikipedia.org/wiki/Barr_body

robbiep2• 13 years ago

Perhaps because those systems aren't chemical gradient systems such as elucidated by Turing?

It's meant to be an interest story/article, not a comprehensive analysis of cell signalling and phenotype display

toufka• 13 years ago

However, the question is about tiger stripes. And modern cell-signaling analysis has given us the answer. So why no discussion about the answer?

tolmasky• 13 years ago

BBC's "The Secret Life of Chaos" covers some of this from kind of a historical perspective. It's a nice pretty superficial documentary, I enjoyed it: http://topdocumentaryfilms.com/secret-life-chaos/

omegaworks• 13 years ago

>convicted of engaging in homosexual acts and sentenced to chemical castration. Amid that personal drama, he still found the time to publish a visionary paper

Even in the face of his entire society condemning him to a crippled existence, it's a testament to his fortitude that he continued producing brilliant works, unfettered. We're left to wonder what other insights Turing might have contributed to human progress had he not been stifled and squandered by the people in power in his day.

History is filled with examples of intellect being trampled on by the establishment: Galileo, Socrates, and even now Aaron Swartz. We still haven't grown out of it. We still need to fight it.

rayiner• 13 years ago

Your comparisons don't even make sense. Turing wasn't "trampled on by the establishment." He was part of the establishment. He spent most of his career working for the government, first in the war effort then later in a national research lab. He was the victim of backwards social policy, not someone who was attacked by the establishment because his intellect was a threat.

duaneb• 13 years ago

I enjoy Turing's contributions as much as the next man, but this really isn't an apt comparison. Socrates talked his way into his own grave when he could have easily gotten out of it. Galileo is probably closer, but the church beefed with his work, not the man per se. Meanwhile, Turing worked for the establishment directly and was very definitely embraced as a researcher. His persecution is completely unrelated to his genius; he seems to serve more as a figurehead for examples of homophobic bigotry because of his success and successive fame and recognition, not because his case was unusual.

That said, I'm happy with the situation; I don't see anything wrong with using him for that purpose. I just don't see much of a parallel because his anti-establishment status wasn't tied to his genius, and is in fact completely separate.

Guthur• 13 years ago

Wiki has a slightly different account of the conviction.

He was not sentenced to chemical castration, though that was the result, the treatment was to reduce the libido.

Interestingly Arnold Murray was released on probation.

Source is wiki of course so possibilities of inaccuracies.

http://en.wikipedia.org/wiki/Alan_Turing#Conviction_for_inde...

Also apparently jail sentences for 'gross indecency' were rarer at the time, "(only 174 of the 746 men convicted of 'gross indecency' in 1951 received prison sentences-typically less than six months)"

According to this: http://drvitelli.typepad.com/providentia/2011/04/the-turing-...

spot2• 13 years ago

what source has no possibility of inaccuracy?

lifeisstillgood• 13 years ago

I feel I have to defend your comment here, as t

The conviction for gross indeceny was socially backwards, yes, but the establishment (which Turing was not a part of ) Completely fumbled his genius - just look at the treatment von Braun and others got because their rocketry work was valuable.

Had the establishment recognised the value of Turing I am quite sure records could have easily been expunged.

But they did not aNd there is no reliable indicator we have learnt our lessons

acheron• 13 years ago

Turing, Galileo, Socrates, Aaron Swartz.

Talk about "one of these things doesn't belong".

j2labs• 13 years ago

I wonder if these patterns are related to male pattern baldness too?

gosub• 13 years ago

How Mathematicians Think About Patterns - Professor Ian Stewart FRS

http://www.youtube.com/watch?v=xLkQFC-Z-Vk

there is a section about tiger stripes, leopard spots etc etc

kbenson• 13 years ago

> A protein called fibroblast growth factor (FGF) serves as the activator, and a gene variant dubbed Sonic hedgehog (Shh) acts as an inhibitor.

That brightened my day just a little bit...

Was Alan Turing right about the mechanism behind tiger stripes?

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