Characters multistate

In this chapter, we discuss the multistate/multifunctional character of the chemistry of synthetic photochromic flavylium compounds and show that the examination of complex chemical systems from novel viewpoints may reveal very interesting features and may be useful to introduce new concepts in the field of chemical... 

Fig. 13. A schematic representation of the multistate and continuum models for metal-amine and metal-ether solutions at (a) high and (b) low temperatures. The multistate picture shown here assumes, for simplicity, two species of atomic character X, and X2. The continuum model suggests a single species with an atomic character ofX(n and X(U> at the extremes of high and low temperatures, respectively. P(X) is a measure of the number of states with a given percent atomic character.

The equilibrium thermodynamical approach implies the unfolding process to be reversible. Reversibility is a consequence of native structure being a minimum energy conformation, and it is in close relation to the highly cooperative character of the transition from the native to the completely unfolded state [33-35]. Cooperativity is reflected in the negligible amount of stable intermediate states between the native and unfolded conformations (two-state behavior), or in the small number of these states as compared to the very large number of possible intermediates (multistate transitions) [33],... 

The ratio r = gD/Af/vH is frequently used as a touchstone to check in a simple way whether the transition departs appreciably from a two-state one [35,40,49]. A ratio significantly higher than 1 would point to a multistate process, even though only one calorimetric peak were observed. However, Freire [43,44] has recently drawn attention to the fact that r does not provide an accurate assessment of the character of the transition and actually can be misleading [43,44,48]. A ratio r< 1 is considered as indicative of an irreversible process, generally due to aggregation of the unfolded species [40],... 

The series is rather like a multistate character ... an initial hypothesis of homology among character states, all states are assumed to be homologous, but no particular relationships are specified (Mabee, 2000 93). Some years ago Griffiths commented on multistate characters (see also Patterson, 1982 68) ... 

As mentioned above. Discrete can analyse only binary characters and any multistate character has to be either excluded from the analyses or transformed into binary ones. For some of the characters used in the present analyses, multistate codings are possible. For instance, the presence of dwarf males (character 1 state 1) can be coded as simple and unbranched, as for Garovaglia, or larger and branched, as for Euptychium, Glyphothecium and Cladomnion. It is therefore possible that the uncertainties in ancestral character state reconstructions might be an artifact of the binary... 

This character is known in few taxa However, it is unlikely to be a multistate character and should be easily coded in future analyses. The rays are typically crescent-like in Hyllingea swanbergi and needle-like in Boreosomus arcticus. 

---