Crumpled polymer with loops recapitulates key features of chromosome organization.

Chromosomes are exceedingly long topologically-constrained polymers compacted in a cell nucleus. We recently suggested that chromosomes are organized into loops by an active process of loop extrusion. Yet loops remain elusive to direct observations in living cells; detection and characterization of myriads of such loops is a major challenge.

Communities in C. elegans connectome through the prism of non-backtracking walks.

The fundamental relationship between the mesoscopic structure of neuronal circuits and organismic functions they subserve is one of the major challenges in contemporary neuroscience. Formation of structurally connected modules of neurons enacts the conversion from single-cell firing to large-scale behaviour of an organism, highlighting the importance of their accurate profiling in the data. While connectomes are typically characterized by significant sparsity of neuronal connections, recent advances in network theory and machine learning have revealed fundamental limitations of traditionally used community detection approaches in cases where the network is sparse.

Stretching of a Fractal Polymer around a Disc Reveals Kardar-Parisi-Zhang Scaling.

While stretching of a polymer along a flat surface is hardly different from the classical Pincus problem of pulling chain ends in free space, the role of curved geometry in conformational statistics of the stretched chain is an exciting open question. We use scaling analysis and computer simulations to examine stretching of a fractal polymer chain around a disc in 2D (or a cylinder in 3D) of radius R. We reveal that the typical excursions of the polymer away from the surface and curvature-induced correlation length scale as Δ∼R^{β} and S^{*}∼R^{1/z}, respectively, with the Kardar-Parisi-Zhang (KPZ) growth β=1/3 and dynamic exponents z=3/2.

Order and stochasticity in the folding of individual Drosophila genomes.

Mammalian and Drosophila genomes are partitioned into topologically associating domains (TADs). Although this partitioning has been reported to be functionally relevant, it is unclear whether TADs represent true physical units located at the same genomic positions in each cell nucleus or emerge as an average of numerous alternative chromatin folding patterns in a cell population. Here, we use a single-nucleus Hi-C technique to construct high-resolution Hi-C maps in individual Drosophila genomes.

Effect of Architecture on Micelle Formation and Liquid-Crystalline Ordering in Solutions of Block Copolymers Comprising Flexible and Rigid Blocks: Rod-Coil vs Y-Shaped vs Comblike Copolymers.

Micelle formation of amphiphilic block copolymers of various architectures comprising both flexible and rodlike blocks were studied in a selective solvent via dissipative particle dynamics (DPD) simulations. Peculiarities of self-assembly of Y-shaped (insoluble rigid block and two flexible soluble arms) and comblike (soluble flexible backbone with insoluble rigid side chains) copolymers are compared with those of equivalent rod-coil diblock copolymers. We have shown that aggregation of the rigid blocks into the dense core of the micelles is accompanied by their nematic ordering.