Saturday, September 08, 2012

Decoding Nature's ENCODE iPad app - OMG it's full of ePUB

The release of the ENCODE (ENCyclopedia Of DNA Element) project has generated much discussion (see Fighting about ENCODE and junk). Perhaps perversely, I'm more interested in the way Nature has packaged the information than the debate about how much of our DNA is "junk."

Nature has a website ( that demonstrates the use of "threads" to navigate through a set of papers. Instead of having to read every paper you can pick a topic and Nature has collected a set of extracts on that topic (such as a figure and its caption) from the relevant papers and linked them together as a thread. Here is a video outlining the rationale behind threads.

Threads can be viewed on Nature's web site, and also in the iPad app. The iPad app is elegant, and contains full text for articles from Nature, Genome Research, Genome Biology, BMC Genetics. Despite being from different journals the text and figures from these articles are displayed in the same format in the app. Curious as to how this was done I "disassembled" the iPad app (see Extract and Explore an iOS App in Mac OS X for how to do this. If you've downloaded the app on your iPad and synced the iPad with your Mac, then the apps are in the folder "iTunes/iTunes Media/Mobile Applications" folder inside your "Music" folder. The app contains a file called, and inside that folder are the articles and threads, all as ePub files. ePub is the format used by a number of book-reading apps, such as Apple's iBooks. Nature has a lot of experience with ePub, using it in their iPhone and iPad journal apps (see my earlier article on these apps, and my web-based clone for more details).

ePub has several advantages in this context over, say, PDFs. Because it ePUb is essentially HTML, the text and images can be reflowed, and it is possible to style the content consistently (imagine how much clunkier things would have looked if the app had used PDFs of the articles, each in the different journals' house style). Having the text in ePub also makes creating threads easy, you simply extract the relevant chunks and combine them into a new ePub file.

Threads are an interesting approach, particularly as they cut across the traditional boundaries of individual articles to create a kind of "mash up." Of course, in the ENCODE app these are preselected for you, you can't create your own thread. But you could imagine having an app that would enable you to not just collect the papers relevant to a topic (as we do with bibliographic software), but enable you to extract the relevant chunks and create a personalised mash up across papers from multiple journals, each linked back to the original article (much like Ted Nelson envisioned for the Xanadu project). It will be interesting to see whether thread-like approaches get more widely adopted. Whatever happens, Nature are consistently coming up with innovative approaches to displaying and navigating the scientific literature.