Indeed, one of the most important advantages of using the lingual straight wire technique is that sliding mechanics enable extraction spaces to be closed without the need for difficult modelling of the closing loop used in non-frictional extraction space closure [3, 5].
His secret weapon was Bezout's Theorem from geometry, which he used to guide him to solutions of very difficult model theoretic problems; for example his theorem that no totally categorical theory can be axiomatised by a finite number of axioms.
Therefore, complexity due to various interactions between different levels is lucrative for nature in many ways although difficult to model for scientists as it obstructs simple abstraction (see also Section 1.2.1).
If the environmental pathway is multimedia, then the number of potential measurements (and hence costs) to assess this cumulative exposure increases dramatically, and the data are more difficult to model for the purpose of predicting human exposures and particularly the internal doses.
The lack of a posterior tibial attachment of the lateral meniscus makes the New Zealand white rabbit a difficult natural history model for lateral meniscal pathology.
These effects are complex and difficult to computationally model, for the 'consequences of the substitution of arginines for lysines is also modulated by the nature of the peptide into which the substitution is made'.
Testing the role of the backbone amide in positioning D101 to, in turn, position R166 will be difficult, but the model for D153 is readily testable: mutation of the nearby side chains is predicted to eliminate the ability of D153 to stimulate R166 function.
In such a model, the diffusion coefficient depends on the degree of saturation, which makes it difficult to use the model for predictions.
This does not mean that the model is adequate, but rather that it is difficult to find any model for these heterogeneous data.
One generalist, scoring heat-related mortality at 'full PDF', suggested that it shouldn't be difficult to "tune a model for mortality surveillance or expected mortality".
