Strategic positioning

Combinations of non-selective and/or single-selective relaxation-rates, or both, with n.0.e. values may conveniently be performed with reliable results, especially when other methods seem impractical. However, these experiments are time-consuming, as they entail the determination of a rather large number of experimental values. Moreover, the n.O.e. parameters carry their own systematic and random errors, which are magnified in the calculation of interproton distances. The deuterium-substitution method requires specific deuteration at a strategic position, which, in many cases, may be inconvenient or impractical. Also, this technique is valid only when the relaxation rates obtained after deuterium substitution are at least 5% enhanced, relative to the relaxation rates of the unsubstituted compound, and it requires that, for a meaningful experiment, the following condition " be satisfied. 

Methyl substitution in strategic positions in polyarenes frequently results in notable enhancement of carcinogenic activity. Thus, methyl substitution at a bay region tends to markedly increase the biological activity (14). Moreover, carcinogenic activities of PAHs are often strongly affected by fluorine substitution at proper molecular sites (3, 15). 

The aim of introducing additional binding sites at strategic positions near the cavity of the crown ether is to create a three-dimensional array of binding sites without calling in the help of the macrobicyclic effect. Gramain and Frere (1979) have studied the effect of two additional OH sites on the complexing... 

The histone variants of H2A form the largest family of identified histone variants (Redon et al, 2002 Sarma and Reinberg, 2005). This could be associated with both the strategic position that has the histone H2A within the histone octamer and the less stable interaction of the H2A-H2B dimmer with both DNA and the (H3-H4)2 tetramer within the nucleosome (Luger et al, 1997). Most of the histone H2A variants exhibit a unique property in addition to the N-terminal tail domain, they also posses an unstructured C-terminal tail. To date four variants of histone H2A have been discovered. These include, H2AZ, H2A.X, macroH2A and H2A.Bbd. The highest differences in the primary structure of these H2A variants are observed in their C-terminal portion. Each of these variants could be efficiently incorporated in the nucleosome in vitro and in vivo. The presence of these variants alter the structural and functional properties of the nucleosome distinctly. 

Strategic position, organic growth, and financial performance... 

Boron rods provide an alternative wood preservative, which is considered safe for people and the environment. They are made of boron compounds that have been subjected to high temperatures to form water-soluble, glassllke rods. These rods are Inserted Into drilled holes In the wood, strategically positioned where decay is most likely the holes are then plugged to keep the rods In place. When the wood becomes wet, boric acid is released, which prevents fungal decay. Boron pastes have a similar effect. Manufacturers of boron rods are seeking to make these rods available for home use. 

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