The effect of noise on the dynamics of a complex map at the period-tripling accumulation point

As shown recently (O.B.Isaeva et al., Phys.Rev E64, 055201), the phenomena intrinsic to dynamics of complex analytic maps under appropriate conditions may occur in physical systems. We study scaling regularities associated with the effect of additive noise upon the period-tripling bifurcation cascade generalizing the renormalization group approach of Crutchfield et al. (Phys.Rev.Lett., 46, 933) and Shraiman et al. (Phys.Rev.Lett., 46, 935), originally developed for the period doubling transition to chaos in the presence of noise. The universal constant determining the rescaling rule for the intensity of the noise in period-tripling is found to be $\gamma=12.2066409...$ Numerical evidence of the expected scaling is demonstrated.Comment: 9 pages, 4 figure

The model of externship organization for future teachers: qualimetric approach

The aim of the paper is to present author’s model for bachelors – future teachers of vocational training. The model is been worked out from the standpoint of qualimetric approach and provides a pedagogical training. Methods. The process is based on the literature analysis of externship organization for students in higher education and includes the SWOT-analysis techniques in pedagogical training. The method of group expert evaluation is the main method of pedagogical qualimetry. Structural components of professional pedagogical competency of students-future teachers are defined. It allows us to determine a development level and criterion of estimation on mastering programme «Vocational training (branch-wise)». Results. This article interprets the concept «pedagogical training»; its basic organization principles during students’ practice are stated. The methods of expert group formation are presented: self-assessment and personal data. Scientific novelty. The externship organization model for future teachers is developed. This model is based on pedagogical training, using qualimetric approach and the SWOT-analysis techniques. Proposed criterion-assessment procedures are managed to determine the developing levels of professional and pedagogical competency. Practical significance. The model is introduced into pedagogical training of educational process of Kalashnikov’s Izhevsk State Technical University, and can be used in other similar educational establishmentsЦель статьи – представить авторскую модель организации практики студентов бакалавриата – будущих педагогов профессионального обучения, разработанную с позиций квалиметрического подхода и предусматривающую проведение педагогических тренингов. Методология и методики исследования. На основе анализа научно-педагогической литературы смоделирован процесс организации практики студентов в высшей школе, включающей технику SWOT-анализа в педагогических тренингах. С использованием метода групповых экспертных оценок – основного метода педагогической квалиметрии – определены структурные компоненты профессионально-педагогической компетентности студентов, обучающихся по направлению подготовки «Профессиональное обучение (по отраслям)», а также уровни ее сформированности и критерии оценивания. Результаты. На основе обобщения практического опыта уточнено понятие «педагогический тренинг», определены основные принципы его организации в период практики. Представлены методы формирования экспертной группы: самооценки и анкетных данных. Научная новизна. Разработана модель организации практики студентов – будущих педагогов профессионального обучения, предусматривающая проведение педагогических тренингов. Особенностью модели является использование квалиметрического подхода и техники SWOT-анализа. Предложены критериально-оценочные процедуры для определения уровня сформированности профессионально-педагогической компетентности. Практическая значимость. Модель организации педагогической практики внедрена в образовательный процесс Ижевского государственного технического университета им. М. Т. Калашникова и может быть использована в других аналогичных образовательных организация

Trends of the major porin gene (ompF) evolution

OmpF is one of the major general porins of Enterobacteriaceae that belongs to the first line of bacterial defense and interactions with the biotic as well as abiotic environments. Porins are surface exposed and their structures strongly reflect the history of multiple interactions with the environmental challenges. Unfortunately, little is known on diversity of porin genes of Enterobacteriaceae and the genus Yersinia especially. We analyzed the sequences of the ompF gene from 73 Yersinia strains covering 14 known species. The phylogenetic analysis placed most of the Yersinia strains in the same line assigned by 16S rDNA-gyrB tree. Very high congruence in the tree topologies was observed for Y. enterocolitica, Y. kristensenii, Y. ruckeri, indicating that intragenic recombination in these species had no effect on the ompF gene. A significant level of intra- and interspecies recombination was found for Y. aleksiciae, Y. intermedia and Y. mollaretii. Our analysis shows that the ompF gene of Yersinia has evolved with nonrandom mutational rate under purifying selection. However, several surface loops in the OmpF porin contain positively selected sites, which very likely reflect adaptive diversification Yersinia to their ecological niches. To our knowledge, this is a first investigation of diversity of the porin gene covering the whole genus of the family Enterobacteriaceae. This study demonstrates that recombination and positive selection both contribute to evolution of ompF, but the relative contribution of these evolutionary forces are different among Yersinia species

Syntheses, crystal structure and magnetic properties of Tl9RETe6 (RE = Ce, Sm, Gd)

The three compounds Tl9RETe6 with RE = Ce, Sm, Gd were synthesized from the elements at 1020 K. Their isostructural crystal structures are ordered derivatives of the Tl5Te3 type with rare-earth metal and thallium occupying different Wyckoff positions. The structures can be understood as charge-ordered in accordance with the Zintl-Klemm concept: 9 Tl+ + RE3+ + 6 Te2-. DFT calculations for Tl9GdTe6, however, result in a low, but finite density of states at the Fermi level. Magnetic data confirm trivalent Gd, but indicate a small amount of Ce4+ in Tl9CeTe6; no indications for long-range magnetic order was found down to T = 2 K