Pattern 16.1 Decoupling

The adjacent groups of protons (J, splitting patterns). Decoupling experiments identify the neighbouring groups of protons. 

Section 7.4 discusses package-level decoupling. Design patterns (such as Pattern 16.15, Role Decoupling, or Pattern 16.17, Observer) provide specific techniques for decoupling. 

What objects should be chosen The first draft is the static model we used for the type specification, although it is modified by design patterns to improve decoupling. 

Packages can be structured in many different ways. The separation of an interface from classes in separate packages provides a pattern for setting up the project package structure. Combined with consistent naming conventions, it makes certain aspects of the architecture very visible in the project development stmcture (see Section 7.4.1, Role-based Decoupling of Classes). 

Use Pattern 16.8, Basic Desiga to sketch interactions between subcomponents. While drafting a basic design, also apply appropriate design patterns (see Section 16.2, Detailed Design Patterns) to improve decoupling. 

Work with particular cases first and then generalize using decoupling patterns. 

Apply generalizations after you complete the basic design. A wide variety of design patterns are directed at generalization and decouphng. Most notable are Pattern 16.15, Role Decoupling and Pattern 16.16, Factories. 

Each type knows about the other (see Pattern 6.4, Refinement Is a Relation and Not a Sequence), something that is frequently represented using a two-way link. Although simple, this link often results in excessive coupling. A simple measure would be to decouple using types (see Section 7.4.1, Role-based Decoupling of Classes). 

This section highlights some essential patterns and shows how they serve the major objectives of decoupling. References to more-detailed discussion on these patterns can be found in the Bibliography. 

Pattern 16.15, Role Decoupling, is used to minimize the Subject s dependence on the Observer. All it knows about is a type that can receive the update messages (see Figure 16.10). Several Observers can watch one Subject at a time. 

Move variation points into separate objects and have only one basic class of principal object (see Figure 16.11). Use Pattern 16.15, Role Decoupling, to keep the principal independent of the various plug-ins. 

In conventional NMR experiments the multiplet pattern (Fig. 10.3) has routinely been collapsed by decoupling on JH. The XH decoupling flips the spin H and concomitantly the sign of BDD(t). Thus, during 15N-evolution each 15N spin is perturbed during half of the evolution time by BCSA(t)+BDD(t) and during the other half of the evolution time by BCSA(t)-BDD(t), which leads to a less favorable relaxation when compared with the relaxation of the component S12 selected by TROSY. 

Parichy DM, Turner JM (2003) Zebrafish puma mutant decouples pigment pattern and somatic metamorphosis. Dev Biol 256 242-257... 

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