Posts – Page 2

Levien van Zon


In September and October 2007, I wrote some material on Enzyme Kinetics for a first-year Biochemistry course for the VU University Amsterdam. The document is in Dutch, and as I wrote it on my own initiative, I grant permission to use it freely under the terms of the Creative Commons ...


PDF Tips & Tricks

Repairing a damaged PDF-file

Ghostscript can “repair” some damaged or buggy PDF-files, by regenerating them. Try something like:

ps2pdf damaged.pdf fixed.pdf

Believe it or not but ps2pdf will happily accept PDF as input, and from it create a new PDF… You can use all the usual Ghostscript options ...


Use and abuse of the Facebook "Like"-code

A while ago I noticed that a lot of my Facebook friends “liked” a page called “This Man Took A Photo Of Himself Everyday For 15 Years In A Row, Look at the Results!”, or something similar. Curious as to what that was about, I clicked on the link. It ...


Useful tricks with spatial data

For my research on Avian Influenza in waterbirds, I recently needed data on lakes and marsh-areas in Europe. I ended up compiling a spatial dataset from a number of different sources, including the EU Corine Land Cover database (CLC2000v13), the lake depth dataset compiled by Ekaterina Kourzeneva for the FLake ...


Scientific Software Favourites

Here’s a little list of software I regularly use for science-related work.

Zotero A highly useful reference manager implemented as a Firefox plugin (although there’s now also a Standalone-version, which works with Chrome, Safari and, well, stand-alone ;-). Especially useful are its features to retrieve citations and PDFs while ...

levien / LibreOffice Tips & Tricks

Installing LibreOffice on Ubuntu 10.04 LTS (Lucid Lynx)

LibreOffice was forked from after Ocracle acquired Sun and started charging money for previously free products (such as the ODF import filter for Microsoft Office). The 3.3 release of LibreOffice has a number of interesting features (such as ...



Zo dat was een gezellig feestje in Den Haag: zo’n 15000 mensen die ongenuanceerde dingen roepen over het kabinetsbeleid, zoals dat hoort in een fatsoenlijke demonstratie. ;-) Des te opvallender dus dat de kamerleden van VVD en CDA op het podium schijnbaar geen beter argument wisten te verzinnen dan “economie ...


Fun With Shapefiles

Shapefiles are a format developed by ESRI (the makers of ArcGIS) to store and share geospatial data. Many interesting datasets are freely available in shapefile format. Shapefiles can be viewed with a number of freely available applications, such as ArcGIS Explorer (which requires the .NET framework or Silverlight) or ArcReader ...


Faxing in Ubuntu

It seems hard to believe, but fax-machines have been around for over a century, and the current digital fax technology stems from the 1980s. Back in the days, for most people faxing a document was the only fast alternative to sending it by normal (as in non-electronic) mail. These days ...


Changing the evolutionary dynamics of Influenza?

An interesting news-article appeared today, claiming a possible breakthrough in the development of a universal influenza vaccine. It describes the development of a new influenza vaccine at the Jenner Institute. Traditional influenza vaccines prime the adaptive immune system against the hemagglutinin (HA) and neuraminidase (NA) proteins (the H and N ...