we give a survey of recent applications of group rings to combinatorics and tocryptography, including their use in the di erential cryptanalysis of block ciphers.

The transport of Balbiani ring (BR) premessenger RNP particles in the larval salivary gland cells of the dipteran Chironomus tentans can be followed using electron microscopy. A BR RNP particle consists of an RNP ribbon bent into a ringlike structure. Upon translocation through the nuclear pore complex (NPC), the ribbon is straightened and enters the central channel of the NPC with the 5' end o...

An efficient N-heterocyclic carbene (NHC) catalyzed sulfenylation reaction of α,β-unsaturated aldehydes with N-(arylthio)phthalimide has been developed. A wide variety of α-thioenals can be obtained with good to excellent yields and excellent Z-configuration.

In this paper we construct a q-deformation of the Witt-Burnside ring of a profinite group over a commutative ring, where q ranges over the ring of integers. When q = 1, this coincides with the Witt-Burnside ring introduced by A. To achieve our goal we show that there exists a q-deformation of the necklace ring of a profinite group over a commutative ring. As in the classical case, i.e., the cas...

The following result is proved: Let R be a 2-torsion free semiprime ring, and let T : R → R be an additive mapping, related to a surjective homomorphism θ : R → R, such that 2T (x2) = T (x)θ(x) + θ(x)T (x) for all x ∈ R. Then T is both a left and a right θ-centralizer.

We present new self-gravitating solutions in five dimensions that describe circular strings, i.e., rings, electrically coupled to a two-form potential (as e.g., fundamental strings do), or to a dual magnetic one-form. The rings are prevented from collapsing by rotation, and they create a field analogous to a dipole, with no net charge measured at infinity. They can have a regular horizon, and w...

We show that interactions of inherently chaotic oscillators can lead to coexistence regular oscillatory regimes and oscillations in the rings coupled provided level interaction between exceeds a threshold value. The transformation initially dynamics into number is shown result from suppression chaos by separation certain oscillation periods continuous spectra, which are characteristic oscillati...

Abstract We are dealing with projective classes (in short $\textrm {PC}$) over first-order vocabularies no restrictions on the (possibly infinite) arities of relation or operation symbols. verify that {PC}(\mathbin {\mathscr {L}}_{\infty \lambda })=\textrm {RPC}(\mathbin })$ for any infinite cardinal $\lambda $, and if $ is singular, then ^+})$. If regular, a class structures $-ary vocabulary }...

Let X be a k-vector space, and U a maximal proper filter of subspaces of X. Then the ring of endomorphisms of X that are ‘‘continuous’’ with respect to U modulo the ideal of those that are ‘‘trivial’’ with respect to U forms a division ring E(U ). (These division rings can also be described as the endomorphism rings of the simple left End( X )-modules.) We study this and the dual construction, ...