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Related papers: A Random Loop Model for Long Polymers

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We propose a model for the formation of chromatin loops based on the diffusive sliding of a DNA-bound factor which can dimerise to form a molecular slip-link. Our slip-links mimic the behaviour of cohesin-like molecules, which, along with…

Biological Physics · Physics 2017-10-04 C. A. Brackley , J. Johnson , D. Michieletto , A. N. Morozov , M. Nicodemi , P. R. Cook , D. Marenduzzo

We investigate the kinetics of a polymer collapse due to the formation of irreversible crosslinks between its monomers. Using the contact probability $P(s)$ as a scale-dependent order parameter depending on the chemical distance $s$, our…

Soft Condensed Matter · Physics 2018-08-15 Vittore F. Scolari , Guillaume Mercy , Romain Koszul , Annick Lesne , Julien Mozziconacci

Condensation of hundreds of mega-base-pair-long human chromosomes in a small nuclear volume is a spectacular phenomenon. This process is driven by the formation of chromosome loops. ATP consuming motor, condensin, interacts with chromatin…

Soft Condensed Matter · Physics 2021-10-27 Ryota Takaki , Atreya Dey , Guang Shi , Dave Thirumalai

Certain polymer models are known to exhibit path localization in the sense that at low temperatures, the average fractional overlap of two independent samples from the Gibbs measure is bounded away from $0$. Nevertheless, the question of…

Probability · Mathematics 2021-08-27 Erik Bates

We argue that complex systems must possess long range correlations and illustrate this idea on the example of the mean field spin glass model. Defined on the complete graph, this model has no genuine concept of distance, but the long range…

Disordered Systems and Neural Networks · Physics 2011-02-23 Alain Billoire , Imre Kondor , Jovanka Lukic , Enzo Marinari

We argue that the mean crossing number of a random polymer configuration is simply a measure of opacity, without being closely related to entanglement as claimed by several authors. We present an easy way of estimating its asymptotic…

Statistical Mechanics · Physics 2009-10-31 Peter Grassberger

We employ 3D Langevin Dynamics simulations to study the dynamics of polymer chains translocating through a nanopore in presence of asymmetric solvent conditions. Initially a large fraction ($>$ 50%) of the chain is placed at the…

Soft Condensed Matter · Physics 2010-06-09 Christopher Lorscher , Tapio Ala-Nissila , Aniket Bhattacharya

Consider directed polymers in a random environment on the complete graph of size $N$. This model can be formulated as a product of i.i.d. $N\times N$ random matrices and its large time asymptotics is captured by Lyapunov exponents and the…

Probability · Mathematics 2018-01-22 Francis Comets , Gregorio R. Moreno Flores , Alejandro F. Ramirez

Loop formation between monomers in the interior of semiflexible chains describes elementary events in biomolecular folding and DNA bending. We calculate analytically the interior distance distribution function for semiflexible chains using…

Soft Condensed Matter · Physics 2009-11-11 Changbong Hyeon , D. Thirumalai

By means of a minimal physical model, we investigate the interplay of two phase transitions at play in chromatin organization: (1) liquid-liquid phase separation (LLPS) within the fluid solvating chromatin, resulting in the formation of…

Biological Physics · Physics 2024-09-24 Reda Tiani , Marie Jardat , Vincent Dahirel

This paper leads with a random polymer model in $\Z^2$ having long-range self-repulsive interactions. By comparison with a long range one-dimensional ferromagnetic Ising model we shown that the polymer models we considered here undergo a…

Probability · Mathematics 2014-05-29 Leandro Cioletti , Chang Dorea , Simone Vasconcelos

Tethered particle experiments use light microscopy to measure the position of a micrometer-sized bead tethered to a microscope slide via a ~micrometer length polymer, in order to infer the behavior of the invisible polymer. Currently, this…

Biological Physics · Physics 2009-11-13 John F. Beausang , Chiara Zurla , Carlo Manzo , David Dunlap , Laura Finzi , Philip C. Nelson

We investigate the phase transition properties of the polymer-Potts model, a chain composed of monomers with magnetic degrees of freedom, with the motivation to study the conformation and mark switching dynamics of chromatin. By the…

Biological Physics · Physics 2019-12-18 Kyosuke Adachi , Kyogo Kawaguchi

Long-distance regulatory interactions between enhancers and their target genes are commonplace in higher eukaryotes. Interposed boundaries or insulators are able to block these long distance regulatory interactions. The mechanistic basis…

Subcellular Processes · Quantitative Biology 2015-05-27 Swagatam Mukhopadhyay , Paul D. Schedl , Vasily M. Studitsky , Anirvan M. Sengupta

Through extensive Monte Carlo simulations, we systematically study the effect of chain stiffness on the packing ability of linear polymers composed of hard spheres in extremely confined monolayers, corresponding effectively to 2D films.…

We investigate mutual local chain order in systems of fully flexible polymer melts in a simple generic bead-spring model. The excluded-volume interaction together with the connectivity leads to local ordering effects which are independent…

Soft Condensed Matter · Physics 2015-06-25 Roland Faller , Mathias Puetz , Florian Mueller-Plathe

We use an off-lattice microscopic model for solutions of equilibrium polymers (EP) in a lamellar shear flow generated by means of a self-consistent external field between parallel hard walls. The individual conformations of the chains are…

Soft Condensed Matter · Physics 2009-10-31 A. Milchev , J. P. Wittmer , D. P. Landau

Epigenetics is a driving force of important and ubiquitous phenomena in nature such as cell differentiation or even metamorphosis. Oppositely to its widespread role, understanding the biophysical principles that allow epigenetics to control…

Soft Condensed Matter · Physics 2020-01-08 Davide Colì , Davide Michieletto , Davide Marenduzzo , Enzo Orlandini

We investigated the viscoelastic response of model interphase chromosomes by tracking the three-dimensional motion of hundreds of dispersed Brownian particles of sizes ranging from the thickness of the chromatin fiber up to slightly above…

Biomolecules · Quantitative Biology 2015-01-06 Manon Valet , Angelo Rosa

We study the conformational properties of heteropolymers containing two types of monomers A and B, modeled as self-avoiding random walks on a regular lattice. Such a model can describe in particular the sequences of hydrophobic and…

Disordered Systems and Neural Networks · Physics 2014-09-01 Viktoria Blavatska , Wolfhard Janke