Hans van den Berg

General theoretical aspects are reviewed of models for microbial growth and endogenous metabolism. The focus is on a generic cell model with two components. Growth is represented as the increase of one of these components (the structural scaffolding or 'frame'). A novel feature of the present generic model is the explicit modelling of (partial) metabolic shutdown under conditions where maintenance requirements cannot be met.Two different approaches to mechanistic underpinnings for the classic models are outlined. The first approach is based on a bimolecular reaction between the non-permanent biomass component and the permanent biomass component. The second approach is based on cellular control systems.

Meta-theories, base-theories and theories of practice in Pratical Theology The problem of meta-theories and base-theories, their interaction and the influence of each on the scientific process, have widely been debated in practical theology. In South Africa two meta-theories namely the system- theory together with the theory that social science is busy with the study of actions, are having the greater deal of attention. The purpose of this article is to point out the fact that an early and absolute choice of particular meta-theories, restricts the work of practical theology because it will influence your base-theories, and can weaken the theological content of practical theology. An attempt is made to offer a model by which the interaction between, meta-theories, base-theories and theories of practice can he understood and which can also help the theologian, busy with practical theology, to steer clear of problems and understand the meta- influences in his own scientific work.