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INTERACTIONS. “Modules can be insulated from or connected to each other. Insulation allows the cell to carry out many diverse reactions without cross-talk that would harm the cell, whereas connectivity allows one function to influence another. The higher-level properties of cells, such as their ability to integrate information from multiple sources, will be described by the pattern of connections among their functional modules.” https://www.nature.com/articles/35011540 View in LinkedIn

MULTIPLE MECHANISMS. “The melting of the surface of a solid can be induced in different ways: by changing the pressure or temperature or by adding impurities. Similarly, different organisms induce the transition between different patterns of microtubule organization that occurs during cell division by changing different members of the set of kinetic parameters that govern microtubule polymerization.” https://www.nature.com/articles/35011540 View in LinkedIn

KEY THESIS. “We have argued that most functional properties of a module are collective properties, arising from the properties of the underlying components and their interactions. Collective properties have long been studied in statistical physics and share attributes that rise above the details.” https://www.nature.com/articles/35011540 View in LinkedIn

SYSTEM TEMPLATE DESIGNS. “Modules may also be related by shared design or functional principles, even if they are not related by descent. The pheromone-detection system of budding yeast and the chemotactic machinery of bacteria use unrelated components, but both pathways achieve a sensitive response over a wide range of pheromone or chemoattractant concentrations by using reactions that specifically turn off active forms of the signalling receptors.” https://www.nature.com/articles/35011540 View in LinkedIn

RELATEDNESS. “Understanding the relatedness of modules is useful because knowledge about one member of a class can inform the study of the others. Relatedness by descent is often apparent from the homology of chemical components.” https://www.nature.com/articles/35011540 View in LinkedIn

STASIS BY NECESSITY. “But if the function of a protein is restricted to one module, and the connections of that module to other modules are through individual proteins, it will be much easier to modify, make and prune connections to other modules. This idea is supported by the analogous observation that proteins that interact with many other proteins, such as histones, actin and tubulin, have changed very little during evolution, and by theoretical arguments that proteins are difficult to evolve once they are participating in many different interactions.” https://www.nature.com/articles/35011540 View in LinkedIn

CONSTITUTIVELY CONSERVED. “If the function of a protein were to directly affect all properties of the cell, it would be hard to change that protein, because an improvement in one function would probably be offset by impairments in others.” https://www.nature.com/articles/35011540 View in LinkedIn

MEASUREMENTS. “From solar observations alone, it is impossible to detect either the solar wind speed in interplanetary space (which is different from the speed near the solar surface) or the structure of the magnetic field and hence the intensity and duration of the geoeffective southward field direction.” https://link.springer.com/article/10.12942/lrsp-2007-1 View in LinkedIn