Guided Modes in the Plane Array of Optical Waveguides

It is known that for an isolated dielectric cylinder waveguide there exists the cutoff frequency $\omega_\ast$ below which there is no guided mode. It is shown in the paper that the infinite plane periodic array of such waveguides possesses the guided modes in the frequency domain which is below the frequency $\omega_\ast$. In the case of a finite array, the modes in this frequency domain are weakly radiating ones, but their quality factor $Q$ increases with the number of waveguides $N$ as $Q(N)\sim N^3$. This dependence is obtained both numerically, using the multiple scattering formalism, and is justified with a simple analytical model

Development of human resources structure for health resort facilities of the Republic of Crimea

The subject matter of this study focuses on the laws and mechanisms of employment in various sectors of the labor market of the Republic of Crimea. The article is devoted to the research of staffing structure for the development of business activities in the Republic of Crimea, in particular, for the health resort complex, to identify priority areas of regional employment policy. The main hypothesis of the research is as follows: there is a discrepancy between the basic parameters of the Crimean labor market transformation and the educational system that makes their proper interaction impossible, causing inconsistencies between the needs and demands of the labor market and the level of training (in particular, in the health resort complex) and the formal qualification of graduates of educational establishments. The methodological framework of the research is based on a systemic approach in studying the labor market of the Republic of Crimea and the use of statistical methods of analysis of the labor market conjuncture. The study analyzed the dynamics of socio-economic development of the Crimean region. The Crimean regional labor market conjuncture was studied, allowing the identification of the main causes of the imbalances in the development of the labor market. The analysis was made with regard to the qualifications of medical professionals graduating from educational establishments and groups of factors affecting the staffing structure were properly identified. The study of reasons of the Crimean labor market discrepancies showed that the current imbalance was caused by both objective and subjective reasons. Priority directions for employment policies have been suggested for the health resort complex. Their implementation will make the stabilization of the situation related to medical staff possible, including for the health resort complex. Such steps will also help improve the potential of human resources, capable of providing highly professional services to holidaymakers; contribute to the effective solution of problems of development of the Republic of Crimea under new economic conditions.The research has been supported by the Russian Foundation for Basic Research and the State Council of Republic of Crimea within the framework of the Project 14-46-01016 r_yug_a (Regional projects)

Technological approaches to the extraction and purification by ultrafiltration techniques of target protein molecules from animal tissues: a review

Effective isolation and purification of protein is a great challenge nowadays. The key aspect is protein stability and solubility, which primarily depend on protein structure and its amino acid sequence. Manipulations with pH and ionic strength are the first at  tempts to increase protein stability and solubility. Different additives that are allowed or prohibited in the food industry are applied for overcoming protein aggregation. Sugars, polyhydric alcohols and amino acids are the most attractive among them. Trehalose, glycerol, arginine, glycine and proline demonstrated outstanding properties that make them perspective for application during iso  lation and purification of proteins singly or in combination with each other or othercompounds. However, the algorithm of effective isolation and purification of protein could be significantly varied depending on its structure. Effective isolation and purification of protein is a great challenge nowadays. The key aspect is protein stability and solubility, which primarily depend on protein structure and its amino acid sequence. Manipulations with pH and ionic strength are the first at  tempts to increase protein stability and solubility. Different additives that are allowed or prohibited in the food industry are applied for overcoming protein aggregation. Sugars, polyhydric alcohols and amino acids are the most attractive among them. Trehalose, glycerol, arginine, glycine and proline demonstrated outstanding properties that make them perspective for application during iso  lation and purification of proteins singly or in combination with each other or othercompounds. However, the algorithm of effective isolation and purification of protein could be significantly varied depending on its structure

Cohomology Groups of Deformations of Line Bundles on Complex Tori

The cohomology groups of line bundles over complex tori (or abelian varieties) are classically studied invariants of these spaces. In this article, we compute the cohomology groups of line bundles over various holomorphic, non-commutative deformations of complex tori. Our analysis interpolates between two extreme cases. The first case is a calculation of the space of (cohomological) theta functions for line bundles over constant, commutative deformations. The second case is a calculation of the cohomologies of non-commutative deformations of degree-zero line bundles.Comment: 24 pages, exposition improved, typos fixe

Connexin-Mediated Signaling in Nonsensory Cells Is Crucial for the Development of Sensory Inner Hair Cells in the Mouse Cochlea

Mutations in the genes encoding for gap junction proteins connexin 26 (Cx26) and connexin 30 (Cx30) have been linked to syndromic and nonsyndromic hearing loss in mice and humans. The release of ATP from connexin hemichannels in cochlear nonsensory cells has been proposed to be the main trigger for action potential activity in immature sensory inner hair cells (IHCs), which is crucial for the refinement of the developing auditory circuitry. Using connexin knock-out mice, we show that IHCs fire spontaneous action potentials even in the absence of ATP-dependent intercellular Ca(2+) signaling in the nonsensory cells. However, this signaling from nonsensory cells was able to increase the intrinsic IHC firing frequency. We also found that connexin expression is key to IHC functional maturation. In Cx26 conditional knock-out mice (Cx26(Sox10-Cre)), the maturation of IHCs, which normally occurs at approximately postnatal day 12, was partially prevented. Although Cx30 has been shown not to be required for hearing in young adult mice, IHCs from Cx30 knock-out mice exhibited a comprehensive brake in their development, such that their basolateral membrane currents and synaptic machinery retain a prehearing phenotype. We propose that IHC functional differentiation into mature sensory receptors is initiated in the prehearing cochlea provided that the expression of either connexin reaches a threshold level. As such, connexins regulate one of the most crucial functional refinements in the mammalian cochlea, the disruption of which contributes to the deafness phenotype observed in mice and DFNB1 patients. SIGNIFICANCE STATEMENT: The correct development and function of the mammalian cochlea relies not only on the sensory hair cells, but also on the surrounding nonsensory cells. Although the nonsensory cells have been largely implicated in the general homeostasis in the mature cochlea, their involvement in the initial functional differentiation of the sensory inner hair cells is less clear. Using mutant mouse models for the most common form of congenital deafness in humans, which are knock-outs for the gap-junction channels connexin 26 and connexin 30 genes, we show that defects in nonsensory cells prevented the functional maturation of inner hair cells. In connexin knock-outs, inner hair cells remained stuck at a prehearing stage of development and, as such, are unable to process sound information

Matrix Factorizations and Homological Mirror Symmetry on the Torus

We consider matrix factorizations and homological mirror symmetry on the torus T^2 using a Landau-Ginzburg description. We identify the basic matrix factorizations of the Landau-Ginzburg superpotential and compute the full spectrum, taking into account the explicit dependence on bulk and boundary moduli. We verify homological mirror symmetry by comparing three-point functions in the A-model and the B-model.Comment: 41 pages, 9 figures, v2: reference added, minor corrections and clarifications, version published in JHE

Bis(dihydrogen norfloxacinium) tri-μ2-chlorido-bis­[trichloridobismuthate(III)] chloride dihydrate

The title compound, {systematic name: (3-carb­oxy-1-ethyl-6-fluoro-7-piperazin-4-ium-1-yl-1H-quinolin-4-yl­idene)oxonium tri-μ2-chlorido-bis­[trichloridobismuthate(III)] chloride dihydrate], (C16H20FN3O3)2[Bi2Cl9]Cl·2H2O, is composed of [Bi2Cl9]3− anions lying on crystallographic twofold rotation axes, Cl− anions also on twofold axes, C16H20FN3O3 2+ cations, and water mol­ecules. The BiIII coordination polyhedron is a distorted octa­hedron and two such octa­hedra share a triangular face to form the complex anion. There are three short terminal Bi—Cl bonds [2.5471 (6)–2.5781(5 Å] and three longer bridging bonds [2.8599 (5)–2.9984 (6) Å] in each octa­hedron. Anions, cations and water mol­ecules are linked by hydrogen bonds to form a three-dimensional network. There are also π–π stacking inter­actions between quinoline ring systems, with an inter­planar distance of 3.27 (1) Å