As is the case for predicting the structural modifications resulting from biotransformation, a purely experimental approach will likely be intractable to determine the regulatory effects of xenobiotic chemicals on CYP enzymes, which may be mediated by ligand-activated nuclear receptors [ 70] controlling the expression of the enzymes.
The available materials are always massively incomplete and you're always having to think of ways of deriving some kind of reasonably likely answer from intractable data.
Note first that the problem of deciding whether a given formula is a tautology is \ \textbf{coNP}\ -complete, and hence very likely to be intractable.
The resolution of names to concepts (see paragraph 3, below) is far more difficult and is likely to be intractable for universal coverage.
These findings reproduce an earlier study where postoperative seizures in the context of AED reduction were more likely to become intractable than those starting after AED discontinuation.
However, the country is going through a period of adjustment, Mr Kissinger said, and as a result, its leaders will be preoccupied with domestic issues at a time when tensions are escalating in the region over the sovereignty of the Diaoyu Islands (even the name is disputed, the islands are called the Senkaku in Japan).Syria, Mr Kissinger said, is likely to remain an intractable problem in 2014.
For the more common scenario where researchers wish to produce a multivariable prognostic model and all model variables are potentially equally important, basing sample size on the significance of numerous individual variables is likely to be an intractable problem.
Despite significant research effort, many merozoite surface ligands have no known erythrocyte binding partner, most likely due to the intractable biochemical nature of membrane-tethered receptor proteins and their interactions.
It is safe to say that the more ethical a political dispute is, the more heated and intractable it is likely to become... [M]oral claims like 'honor killing is wrong' are not good candidates for being simply true or false statements.
"But it is the corporate restructuring necessary to reduce high corporate savings rates that is likely to prove most politically intractable, requiring authoritarian and semi-authoritarian governments to relinquish state control of economic resources and activity on which their political power is partly based," Ms. Lim added.
