Unlike graph-based paths which may only include the main compounds and reactions in a pathway, elementary flux modes and extreme pathways provides a more complete summary of the requisite intermediate compounds and enzymes while conforming to steady-state constraints.
SMDA's approach of evaluating the activation/inactivation scenarios of the metabolic network at steady state is related to metabolic network analysis techniques, such as MCA (1), FBA (2), metabolic flux analysis (20) and, finally, metabolic pathway analysis (elementary flux modes and extreme pathways) (21).
Thus elementary modes and extreme pathways play a growing role in the analysis of complex biochemical reaction networks [9].
The use of structural analysis tools such as elementary modes and extreme pathways [ 1], suffers from the problem of a combinatorial explosion [ 2] of the number of such modes in a complex network.
For instance, elementary modes and extreme pathways have been used to exhaustively describe the independent metabolic routes occurring in newly reconstructed models, often sorted by metabolic function (Schilling & Palsson, 2000; Van Dien & Lidstrom, 2002; Papin et al., 2002).
To assess modes of reproduction and pathways of embryo formation, flow cytometric seed screening (FCSS) is a highly efficient method (Matzk et al., 2000).
The unprecedented substrate binding mode and cleavage pathway for phenylpyruvate-type structures at the 3-His center of Dke1 suggest that the metal binding motif may contribute to stabilizing the substrate ligand in the correct ionization state.
However, both elementary mode and extreme pathway analysis [ 13] cannot be scaled up to analyze genome-scale metabolic networks, and to circumvent these problems, Schuster and colleagues have recently developed the concept of elementary flux patterns [ 14] closely related to elementary modes which can be applied to genome-scale networks.
For the steady state approach we used two software products, one computing elementary modes and the other extreme pathways.
Both the mode of delivery and pathway of care provider training have a significant impact on the cost of delivering the intervention and, as a result, the likelihood of implementation in routine care.
