Diffusion through semipermeable structures arises in a wide range of processes the physical and life sciences. Examples at microscopic level from artificial membranes for reverse osmosis to lipid bilayers regulating molecular transport biological cells chemical electrical gap junctions. There are also macroscopic analogs such as animal migration heterogeneous landscapes. It has recently been sh...

© 2009 Stephen Finlay S ince its publication in 1979, Bernard Williams’ “Internal and External Reasons”1 has been one of the most influential and widely discussed papers in ethics. I suggest here that the paper’s argument has nevertheless been universally misunderstood.2 On the standard interpretations, his argument — which he subsequently elaborated and de...

Although object-orientation has been around for several decades, its key concept abstraction has not been exploited for proper application of object-orientation in other phases of software development than the implementation phase. We mention some issues that lead to a lot of confusion and obscurity with object-orientation and its application in software development. We describe object-orientat...

This Special Issue of BioSystems is devoted to clarifying the concept, and to showing how it’s being used in various examples of empirical research. Given the obscurity that still attends the concept, however, we shouldn’t expect to find that all the ’clarifications’ are equivalent--or even mutually consistent. Similarly, we shouldn’t expect to find that the notion is applied identically in all...