Friday 5 December 2014

Origins and functional consequences of somatic mitochondrial DNA mutations in human cancer

http://elifesciences.org/content/3/e02935

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Wednesday 3 December 2014

Explicit Tracking of Uncertainty Increases the Power of Quantitative Rule-of-Thumb Reasoning in Cell Biology

http://www.cell.com/biophysj/abstract/S0006-3495%2814%2901124-2

Biological quantities often come with substantial associated uncertainty, either because experimental measurements have errors, or biological systems are naturally variable (or both). This uncertainty sometimes makes it hard to fully interpret rough calculations in biology, because uncertainties in quantities can combine in non-obvious ways. This (awesome :-) ) paper introduces an approach and web tool designed to perform calculations while explicitly tracking uncertainty, so that a calculation doesn't result in a single number but rather a descriptive interpretable distribution. The web tool is linked to the BioNumbers database of experimental measurements in biology, facilitating quick and easy "back-of-the-envelope" calculations in biology.


As a mitochondrial example, here's a toy calculation of the number of protons in a mitochondrion. BioNumber #100438 gives us a guess at the volume of a mitochondrion; BioNumber #105939 tells us the internal pH (each quantity has an uncertainty). We can use the two values to estimate the number of protons in a mitochondrion:
http://www.caladis.org/compute/?q=10^%28-%24105939%29*6e23*%24100438*1e-15&v=105939%3Alogn%2C7.98%2C0.07%3B100438%3Alogn%2C0.5%2C0.25&x=off&n=m&h=fd&a=rad