Emergent property model

The reader is encouraged to run this model and collect the average cluster size of amphiphile cells. Observing the run reveals a view of the emergent property known as micelle formation. Periodic halting of the run when these micelles are prominent will be of interest. Try a screen grab of several good examples. 

Ants are a remarkably snccessfnl gronp of social insects. They are almost everywhere only Iceland, Greenland, Polynesia, and Antarctica lack ants. There are 10,000 known species of these insects. Their engineering and social coordination is amazing, particnlarly given that no one is in charge. Steven Johnson has employed the ants as a model of emergence— properties of a system not possessed by any member of that system. Johnson notes ... 

We can say of the full spectrum of systems that each system is complex, i.e. itself composed of subsystems, and that it is an ingredient of a larger system. Each system loses characteristics in the development of the emergent properties of its next-up neighbour, those things lost being subsumed into the characteristics of the more complex neighbour. Perhaps only some philosophers of science would embrace this complete spectrum of nature s systems in their studies and models. 

The model of a molecule derived from the circle of research (Fig. 4) must be critically evaluated as to whether it contains the information associated with the emergent behaviour of the molecule. In other words, the question must be asked whether information from the atom level exceeds the logical depth necessary to understand the emergent properties of molecules as they relate to drug research (Kier and Hall, 1992). 

FIGURE 10 The relationships between evapotranspiration and net primary production as they emerge from the Century model, applied globally. The near-linear realtionship between evaporation and NPP, very similar to those observed In semi-arid lands, is an emergent property. The differences in slope between biomes are largely due to differences in the C N ratio of different plant functional types. Indicating that ecosystem composition has direct effects on biogeochemistry (Scholes et al., 1999). 

As a model of the material universe it promises the detailed characterization of any object as predicted by the properties of less complex entities. The feasibility of this process seems to be supported by the reductionist argument whereby the properties of any complex system can be logically reduced to those of a more elementary system. In this way the properties of a complex molecule can be shown to be consistent with the properties of its atomic constituents, which in turn, can be reduced to those of their sub-atomic building blocks. To the frustration of many a philosopher the inverse, constructionist procedure, after many attempts, appears not to be feasible. At each level of higher complexity unpredictable, so-called emergent properties, invariably show up. 

Respiratory rhythmicity is an emergent property of the RCPG resulting from mutual inhibition of inspiratory and expiratory related neurons. A minimal model due to Duffin [1991] postulated the early-burst inspiratory (I) neurons and Botzinger complex expiratory (E) neurons to be the mutually inhibiting pair. Adaptation of the I neurons (e.g., by calcium-activated potassium conductance) results in sustained relaxation oscillation in the network under constant chemical excitation. Both neuron groups are assumed to have monosynaptic inhibitory projections to bulbospinal inspiratory (Ir) output neurons (Figure 11.3). The model equations are ... 

The new model of accidents introduced in part II of this book incorporates the basic systems theory idea of hierarchical levels, where constraints or lack of constraints at the higher levels control or allow lower-level behavior. Safety is treated as an emergent property at each of these levels. Safety depends on the enforcement of constraints on the behavior of the components in the system, including constraints on their potential interactions. Safety in the batch chemical reactor in the previous chapter, for example, depends on the enforcement of a constraint on the relationship between the state of the catalyst valve and the water valve. 

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