Random loop model for long polymers

Random loop model for long polymers.

Remarkably little is known about the higher-order folding motifs of the chromatin fiber inside the cell nucleus. Folding depends among others on local gene density and transcriptional activity and plays an important role in gene regulation. Strikingly, at fiber lengths above 5 to 10 Mb the measured mean square distance between any two points on the chromatin fiber is independent of polymer...

Constrained random-force model for weakly bending semiflexible polymers.

The random-force (Larkin) model of a directed elastic string subject to quenched random forces in the transverse directions has been a paradigm in the statistical physics of disordered systems. In this Brief Report, we investigate a modified version of the above model where the total transverse force along the polymer contour and the related total torque, in each realization of disorder, vanish...

a Comparative Theoretical Analysis for a Knitted Loop Model

The theory presented in this paper differs from previous ones in that no arbitrary loop shape is assumed. Rather a strophoid curve, that is similar to knitted fabric Loop shape, has been assumed as the basic mathematical function. Additionally, the theory is improved by adapting buckled elastic rod theory, leading to a new equation from a certain mathematical curve. This loop model is assumed t...

Polymers with Random Self - Interactions

Crowding-induced structural alterations of random-loop chromosome model.

We investigate structural alterations of random-loop polymers due to changes in the crowding condition, as a model to study environmental effects on the structure of chromosome subcompartments. The polymer structure is changed in a nonmonotonic fashion with an increasing density of crowders: condensed at small volume fractions; decondensed at high crowding volume fractions. The nonmonotonic beh...