Modeling activation dynamics

Modeling Activation Dynamics. As noted is Sec. 6.5.1 ( Neural Excitation of Muscle ), muscle cannot activate or relax instantaneously. The delay between excitation and activation (or the development of muscle force) is due mainly to the time taken for calcium pumped out of the sarcoplasmic reticulum to travel down the T-tubule system and bind to troponin (Ebashi and Endo, 1968). This delay is often modeled as a first-order process (Zajac and Gordon 1989 Pandy et al., 1992) ... 

The present discussion of continuum modeling of dynamic fracture is not an exhaustive review. Rather, it points out the variety of approaches which have been, and are still being, pursued to provide methods for calculating dynamic fracture phenomena. Such work is still quite active and considerable effort... 

Briihl, C., and Crutzen, P.J. (1988) Scenarios of possible changes in atmospheric temperatures and ozone concentrations due to man s activities, estimated with a one-dimensional coupled photochemical climate model. Climate Dynamics 2,173-203. 

J. Li, P. Beroza, L. Noodleman and D.A. Case. Quantum mechanical modeling of active sites in metalloproteins. In L. Banci and P. Comba, (ed), Molecular Modeling and Dynamics of Bioinorganic Systems, Proceedings of NATO ASI Workshop, Kluwer, Dordrecht, pp. 279, 1997. 

Very fast electron transfers from P+ to bacteriochlorophyl (Bchl) and from (Bchl)- to QA do not depend on media dynamics and occur via conformationally non-equilibrium states (Fig.3.18). The dual fluorophore-nitroxide molecules (D-A) are also convenient objects for analysing the activity-dynamics relationship. The marked irreversible photoreduction of the nitroxide fragment of the dual probe incorporated into the binding site of HSA only took place when the nanosecond dynamical processes around the probe traced by ESR and fluorescence methods were detected (Rubtsova et al., 1993, Fogel et al, 1994 Likhtenshtein, 1986 Lozinsky et al., 2002). Similar results were reported for another model protein system, i.e. a-chymotrypsin with spin labeled methionin-92 groups (Belonogova et al., 1997). In the latter enzyme, the excited tryptophan group serves as an electron donor. 

Currently suggested models for tunneling increasingly invoke protein dynamics . These models envision either a series of conformational fluctuations that lead to a suitable tunneling configuration ( passive dynamics ) or a more active role for the enzyme motions ( active dynamics or gating ).64 On the model of... 

In the case of actor-oriented simulation models, system dynamics are produced by actors (persons or organizational units) based on specific activities [261, 426, 599, 604, 771, 813]. 

In process-oriented simulation models, system dynamics are produced by activities through the usage of resources (persons, tools) [571, 596, 597, 691, 925]. 

Current activities in modelling adsorption dynamics are restricted to transport phenomena involving only simple flow geometries. More complicated problems of dynamic adsorption layers (DAL) remain to be solved. 

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