Variant structures

In fixed structures, as described in Fixed structure type on page 25, the sequence of the attribute definitions is fixed. In case of a variant structure type the structure attribute number and the structure attribute definitions of the structure type can be dependent on the value of variant parameters. A variant structure attribute definition is denoted by the sequence 

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Courtois S, de Fromentel CC, Hainaut P. p53 protein variants Structural and functional similarities with p63 and p73 isoforms. Oncogene 2004 23(3) 631-8. 

According to Lehn et al. [34], in the case of the template mediated selfconstruction of a supramolecular system, amidst a set of possibilities, a combination of building blocks is realized, which leads to the best receptor for the substrate. Therefore, it is possible that the six-membered cyclic structure Na c Fe(i[N(CH2CH20)3]5 Cl 19 is exclusively selected from all the imaginable iron triethanolamine oligomers, when sodium ions are present. Thus, in the presence of cations with ionic radii that differ from that of sodium, variant structures are expected. 

As will be illustrated in subsequent chapters, numerous variants of the apatite atomic arrangement exist. The variant structures, all sub-symmetries of the atomic arrangement of apatite sensu stricto, result principally from chemical substitutions (or, in the case of pure chlorapatite and pure hydroxylapatite, lack of chemical substitutions) on cation and/or anion sites. To provide a framework for discussion, we here describe the holosymmetric apatite structure, in space group PGs/m ( 176). 

Allaix, D.L., Carbone, V.I. Mandni, G. 2009. Recent advances in the modelling of space-variant structural properties. In H. Furuta, D.M. Frangopol M. Shinozuka (eds.), Proa ICOSSAR 2009, Osdca, 13-17 September 2009. Leiden CRC Press/Balkema. 

Wen YK. and H-C., Chen, On Fast Integration for Time Variant Structural Reliability, Probabilistic Engineering Mechanics, Vol. 2, No.3, 1987. 

In case of a generic structure, PARAMETRIC TYPE is either a parametric fixed structure or a variant structure. The parameter types have to be class types (see Classes on page 28) or, in case of a generic variant structure, enumeration types. 

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