Even before the dawn of civilization, trade was important to the inhabitants of Mesopotamia. In the southern part, where the first cities were built, the only natural resource of importance was dirt. With proper care and irrigation, the dirt could produce what was, for its time, an impressive crop yield. The results of this were twofold. First, people had time to devote to pursuits other than t...

We established a straightforward experimental system to investigate directly the requirements for nucleocytoplasmic transport in live cells. For this purpose, substrates were created containing nuclear localization signals (NLS) or nuclear export signals (NES) linked to a chimeric protein composed of the glutathione S-transferase (GST) fused to the green fluorescent protein (GFP). The combinati...

I. Introduction During the past three decades, there has been a paradigm shift from import substitution strategies towards export‐oriented industrialization. It is in this context that countries saw the need to create special economic zones (SEZs) and export processing zones (EPZs), so‐called ecozones, to cope with the increasingly competitive environment of the global market.

The rsbml package supports the import, validation, and export of SBML data. It is similar in purpose to the SBMLR package [Radivoyevitch, 2004], except rsbml relies on the external library libsbml [Bornstein, 2006] for its speed and reliability. With rsbml, the user may import an SBML model as a graph object or an S4-based Document Object Model (DOM). Parsed models may be checked for consistenc...

Nuclear targeting of beta-catenin is an obligatory step in Wnt signal transduction, but the factors that control import and export remain to be clarified. In this issue, Hendriksen et al. (p. 785) show that the RanBP3 export factor antagonizes beta-catenin/T cell factor (TCF) transcription by targeting the signaling-competent form of beta-catenin. We speculate that cells may use multiple export...