On finite groups with disconnected prime graph

All finite simple nonabelian groups that have the same prime graph as a Frobenius group or a 2-Frobenius group are found. © 2013 Pleiades Publishing, Ltd

Design and Goedel theorems

Рассматриваются математические модели восприятия текстов, основанные на распознавании образов и математической логике, а также на пределах формализации.The mathematical models are proposed, described the perception processes through pattern recognition and mathematical logics, and limits of formalization

Interpretation of contradictory images by means of systems of linear inequalities

We consider the problem of interpretation of three-dimensional images from their flat projections up to the set of visible faces. For projections of convex polyhedra, we present an interpretation algorithm based on maximal feasible subsystems of a certain infeasible system of linear inequalities modeling the visibility requirement for faces. A number of model examples are given; in particular, the algorithm is applied to the interpretation of the Necker cube. © 2013 Pleiades Publishing, Ltd

Unsolved Problems in Group Theory. The Kourovka Notebook

This is a collection of open problems in group theory proposed by hundreds of mathematicians from all over the world. It has been published every 2-4 years in Novosibirsk since 1965. This is the 19th edition, which contains 111 new problems and a number of comments on about 1000 problems from the previous editions.Comment: A few new solutions and references have been added or update

Minimal Committee Problem for Inconsistent Systems of Linear Inequalities on the Plane

A representation of an arbitrary system of strict linear inequalities in R^n as a system of points is proposed. The representation is obtained by using a so-called polarity. Based on this representation an algorithm for constructing a committee solution of an inconsistent plane system of linear inequalities is given. A solution of two problems on minimal committee of a plane system is proposed. The obtained solutions to these problems can be found by means of the proposed algorithm.Comment: 29 pages, 2 figure

Finite groups isospectral to simple groups

The spectrum of a finite group is the set of element orders of this group. The main goal of this paper is to survey results concerning recognition of finite simple groups by spectrum, in particular, to list all finite simple groups for which the recognition problem is solved

Geometric estimation of volcanic eruption column height from GOES-R near-limb imagery-Part 2: Case studies

In a companion paper (Horváth et al., 2021), we introduced a new technique to estimate volcanic eruption column height from extremely oblique near-limb geostationary views. The current paper demonstrates and validates the technique in a number of recent eruptions, ranging from ones with weak columnar plumes to subplinian events with massive umbrella clouds and overshooting tops that penetrate the stratosphere. Due to its purely geometric nature, the new method is shown to be unaffected by the limitations of the traditional brightness temperature method, such as height underestimation in subpixel and semitransparent plumes, ambiguous solutions near the tropopause temperature inversion, or the lack of solutions in undercooled plumes. The side view height estimates were in good agreement with plume heights derived from ground-based video and satellite stereo observations, suggesting they can be a useful complement to established techniques

The association of polymorphic alleles of folate metabolism genes with ivf and et failures

The purpose of the study was to determine the effects of polymorphic variants of folate cycle genes with pregnancy rate in IVF and ET protocols.Materials and methods: a comparative is satisfied an open prospective cohort study in 87 patients with IVF failure and 46 patients, who became pregnant and gave birth after IVF and ET. All patients performed a survey of genetic polymorphisms of MTHFR C677T, MTR A2756G and MTRR A66G genes. Results. Revealed that patients in the group with IVF failed statistically significant increase in the proportion of polymorphic allele 677T (p = 0,030, OR -1,71 (0,96-3,03)), and allele 677T with allele 66G combination (p = 0,049, OR -1,86 (0,87-3,96)).Conclusions. The presence of homozygous or heterozygous form of mutation of the gene MTHFR (genotype 677C/T and 677ТЯ), as well as any form of combination of this mutation with a mutation of the gene MTRR (genotype 66A/G, 66G/G) is associated with a reduction in the effectiveness of IVF and ET.Цель работы заключалась в определении влияния полиморфных вариантов генов фолатного цикла на частоту наступления беременности в протоколе ЭКО и ПЭ. Материалы и методы: выполнено открытое сравнительное проспективное когортное исследование 87 пациенток с неудачами ЭКО и ПЭ и 46 пациенток, забеременевших и родивших в результате ЭКО и ПЭ. Всем пациенткам выполнено обследование на генетические полиморфизмы генов MTHFR (С677Т), MTR (A2756G), MTRR (A66G). Результаты. Выявлено, что у пациенток из группы с неудачной попыткой ЭКО и ПЭ отмечается достоверное увеличение доли полиморфного аллеля 677Т (р=0,030, OR -1,71 (0,96-3,03)), а так же увеличение доли сочетания аллеля 677Т с аллелем 66G (р=0,049. OR - 1,86 (0,87-3,96)).Выводы. Наличие гомозиготной или гетерозиготной формы мутации гена MTHFR (генотип 677СЯ и 677ТЯ), а так же сочетание любой формы данной мутации с мутацией гена MTRR (генотип 66A/G, 66G/G) ассоциировано со снижением эффективности программы ЭКО и ПЭ