Wednesday, February 23, 2011

A bookmarklet for

shortDOI is a URL shortening service that takes DOIs and converts them to short URLs such as, which is nice for emails and Twitter. You can add the bookmarklet by dragging this link to your bookmarks: shortDOI. It will try to find the DOI in the current page and direct you to shortDOI.

A shortDOI URL is probably more persistent than, say,, as it's backed by the organization that maintains the DOI infrastructure. However, if would go down, you could always use a search engine if you have the original DOI, but the shortDOI URL will be worthless.

Update 24.02.2011: Use some majority voting to find the right DOI.
Update 01.03.2011: Expand the list of allowed characters. Does anybody know which characters can be part of the DOI?
Update 29.07.2015: Be strict about having a prefix and suffix. First check for the "citation_doi" meta tag before looking in the rest of the document.

Monday, February 21, 2011

Why should we apply Moore's Law to DNA sequencing?

In this chart of cost per megabase of DNA sequence, an extrapolation based on Moore's Law has been added. What's wrong with this? It starts in 2001, the year of the human genome.

In 2001, only few animal genomes had been published (starting with worm in 1998). If I had to compare the human genome to a computer, I'd pick ENIAC. Moore's Law, however, was stated in 1965, some 20 years after the first "real" (i.e. Turing-complete) computers like the Zuse Z3 or ENIAC. When you go back, Moore's law doesn't hold anymore:

Source: Hans Moravec
The overall rate of progress in the pre-transistor era is lower than the rate of the transistor era–which is perhaps no wonder, as Moore's law had originally been defined as the number of transistors per chip.

With which rate will DNA sequencing progress? Perhaps the sharp decrease in sequencing costs between 2008 and 2010 is comparable to the transition from vacuum tubes to transistors, and Moore's Law will be followed from now on (extrapolating from three data points...). But perhaps we'll see more sharp decreases, and should overcome the desire to extrapolate using Moore's Law from arbitrary starting points.

(HT Deepak.)