We study perfect matchings, or close-packed dimer coverings, of finite sections the eleven Archimedean lattices and give a constructive proof showing that any two matchings can be transformed into each other using small sets local ring-exchange moves. This result has direct consequences for formulating quantum models with resonating valence bond ground state, i.e., superposition all coverings c...

Although OWL 2 is widely used to describe complex objects such as chemical molecules, it cannot represent ‘structural’ features of chemical entities (e.g., having a ring). A combination of rules and description graphs (DGs) has been proposed as a possible solution, but it still exhibits several drawbacks. In this paper we present a radically different approach that we call Description Graph Log...

We report a silicon DQPSK receiver whose symbol rate can be varied by a tunable one-bit delay line including an all-pass micro-ring slow-light device. It also consists of Si-wire waveguides with spot-size converters, optimized splitters/couplers, heater-controlled Mach-Zehnder attenuators and phase shifters, 90° hybrid with a low-loss crossing and balanced Ge photodiodes, all of which are fabri...

We report a rare case of pancreatic acinar cell carcinoma with widespread metastases in a 68-year-old woman who presented with subcutaneous nodules as the initial symptom. Computed tomography showed a pancreatic mass with hepatic tumors and enlarged lymph nodes besides ring-enhanced subcutaneous nodules. Magnetic resonance diffusionweighted imaging detected the presence of lesions in other orga...

Among the descriptors of the molecular structure of carbohydrates, the conformation of the pyranose ring is usually the most problematic one to tackle. We present the results of a systematic study oriented at determining the ring-inversion properties of all d-hexopyranoses in the form of monosaccharides, O1-methylated monosaccharides and homotrisaccharides. Contrary to the existing studies, bas...

A module MR is called right principally quasi-Baer (or simply right p.q.-Baer) if the right annihilator of a principal submodule of R is generated by an idempotent. Let R be a ring. Let α be an endomorphism of R and MR be a α-compatible module and T = R[[x;α]]. It is shown that M [[x]]T is right p.q.-Baer if and only if MR is right p.q.-Baer and the right annihilator of any countably-generated ...

We study a class of simply connected manifolds in all odd dimensions greater than 3 that exhibit an infinite number of toric contact structures of Reeb type that are inequivalent as contact structures. We compute the cohomology ring of our manifolds by using the join construction for Sasaki manifolds and show that all such contact structures admit a ray of compatible Sasaki metrics of constant ...

Abstract The algebraic notions of separable extension and split extension of rings, S ⊂ A, are defined dually. If compatible sections and retracts can be found, A is said to be a finite separable extension of S. Then the endomorphism ring homS(A,A) is a finite separable extension of A with a special cyclic idempotent. This construction may be iterated as in Jones theory. The Jones polynomial is...

Koebner phenomenon is observed in a number of inflammatory skin diseases. Psoriasis is one of the most common skin diseases associated with Koebner phenomenon. Nail psoriasis may be developed independently from inflammatory arthritis and skin psoriasis. This study reports on the reconstruction of third web of a 30-year-old woman, which performed on her right, due to congenital syndactyly. Four ...

A K3 surface X over a p-adic field K is said to have good reduction if it admits a proper smooth model over the integer ring of K. Assuming this, we say that a subgroup G of Aut(X) is extendable if X admits a proper smooth model equipped with G-action (compatible with the action on X). We show that G is extendable if it is of finite order prime to p and acts symplectically (that is, preserves t...