For instance, subtelomeric chromatin could preclude the activity of E. coli topoisomerase I during transcription and thus helical tension could not built up; or subtelomeric chromatin could constrain helical tension in a way that allowed transcription to proceed close to normal rates.
A boundary control was proposed for station keeping of a tethered satellite system in the literature, but the proposed boundary controller does not constrain the tension in the tether to be positive.
Second, our results suggest that frictional restrictions to DNA twist diffusion might be an important determinant for constraining helical tension along eukaryotic chromatin.
The Lagrangean description of the motion of the viscous melt in the drops, as constrained by surface tension and the developing contact with the target, has been coupled to an analysis of transient thermal phenomena accounting also for the solidification of the material.
How DNA helical tension is constrained along the linear chromosomes of eukaryotic cells is poorly understood.
One possible answer is that helical tension is constrained within topologically closed DNA domains all along each linear chromosome, with the sole exception of their terminal compartments that are topologically open.
Therefore, the issue of whether DNA is organized into closed topological domains in which helical tension is constrained is less clear and remains controversial (Eissenberg et al, 1985; Esposito and Sinden, 1988; Freeman and Garrard, 1992).
The same doggedness was evident against the Irish, when the game was so tightly balanced that tension might have constrained the home side.
Another approach to quantifying long-range interactions involves regarding the glassy water films covering protein chains as surface chain packages constrained by water-protein interfacial tension that are deformed by the combined effects of mutational and dynamical conformational differences.
Because hydrogen bonds that are more symmetric than this are stretched by the repulsion between X and Y, the X−H and H··· X bonds are in tension and are constrained to be linear, that is, the X−H··· Y angle is 180°, and eq 26 no longer strictly applies as can be seen from an inspections of the bond-valence - bond-length correlation for H−O bonds shown in Figure 19.
