The interaction between two stiff parallel DNA molecules is discussed using linear Debye-Hückel screening theory with and without inclusion of the dielectric discontinuity at the DNA surface, taking into account the helical symmetry of DNA. The pair potential furthermore includes the amount and distribution of counterions adsorbed on the DNA surface. The interaction does not only depend on the ...

In a spin-glass system on a random graph, some vertices have their spins changing among different configurations of a ground-state domain. Long-range frustrations may exist among these unfrozen vertices in the sense that certain combinations of spin values for these vertices may never appear in any configuration of this domain. We present a mean field theory to tackle such long-range frustratio...

In the laboratory, IM7 has been found to have an unusual folding mechanism in which an "on-pathway" intermediate with nonnative interactions is formed. We show that this intermediate is a consequence of an unusual cluster of highly frustrated interactions in the native structure. This cluster is involved in the binding of IM7 to its target, Colicin E7. Redesign of residues in this cluster to el...

The article is devoted to the subjective reaction of patients at different stages of disabling disease, in the context of the formation of a specific cognitive-emotional and motivational model of "internal picture of disability", depending on the severity of social frustration as the most important deconditioning factor. We wanted to identify psychological determinant of the specificity of adap...

We analyze the frustrated Heisenberg antiferromagnet defined on a honeycomb lattice using a Schwinger-boson mean-field theory. The spin-wave velocity and the susceptibility are presented as functions of the strength of the frustrating interaction for spin S = 12 , and the dynamic structure factor is calculated for various temperatures and frustrations. For large S, we find an increased Néel sta...

We study a triangular frustrated antiferromagnetic Heisenberg model with nearest-neighbor interactions J(1) and third-nearest-neighbor interactions J(3) by means of Schwinger-boson mean-field theory. By setting an antiferromagnetic J(3) and varying J(1) from positive to negative values, we disclose the low-temperature features of its interesting incommensurate phase. The gapless dispersion of q...

The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S=1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounti...

The phase diagram of the frustrated 2D classical and 1D quantum XY models is calculated analytically. Four transitions are found: the vortex unbinding transitions triggered by strong fluctuations occur above and below the chiral transition temperature. Vortex interaction is short range on small and logarithmic on large scales. The chiral transition, though belonging to the Ising universality cl...