Global Dimension of Polynomial Rings in Partially Commuting Variables

For any free partially commutative monoid $M(E,I)$, we compute the global dimension of the category of $M(E,I)$-objects in an Abelian category with exact coproducts. As a corollary, we generalize Hilbert's Syzygy Theorem to polynomial rings in partially commuting variables.Comment: 11 pages, 2 figure

Environmental impact assessment activities of mining and processing enterprises of the South Urals on a grassy, treekostenoglou and woody vegetation

В статье приведен анализ экологических последствий наносимых горно-обогатительными комбинатами Южного Урала на травянистую, древесно-кустарниковую и древесную растительность. При помощи метода пробных площадей был подсчитан видовой состав растительного покрова, определено количество лекарственных видов на каждом объекте. Данный анализ помог рассмотреть экологические последствия деятельности исследуемых горно-обогатительных комбинатов, а также разработать методы снижения риска негативного воздействия. The article presents the analysis of the environmental effects of the applied mining and processing plant southern Urals on the grassy, tree-shrub and woody vegetation. Using the sample plots were counted species composition of vegetation determine the number of medicinal species at each site. This analysis helped to consider the environmental impact of the activities of the studied mining and processing, and to develop methods to reduce the risk of adverse effects

Estimations of solutions convergence of hybrid systems consisting of linear equations with delay

The logic-dynamical hybrid system given by a set of subsystems which are linear differential-difference equations with constant coefficients and constant delay is investigated in the paper. The estimations of disturbances of such system are obtained. We consider the cases of stable and unstable subsystems. Besides the estimations of solutions of hybrid system given by a set of scalar subsystems are obtained

In vitro Reconstitution of the S. aureus 30S Ribosomal Subunit and RbfA Factor Complex for Structural Studies

© 2020, Pleiades Publishing, Ltd. Abstract: Ribosome-binding factor A (RbfA) from Staphylococcus aureus is a cold adaptation protein that is required for the growth of pathogenic cells at low temperatures (10-15°C). RbfA is involved in the processing of 16S rRNA, as well as in the assembly and stabilization of the small 30S ribosomal subunit. Structural studies of the 30S–RbfA complex will help to better understand their interaction, the mechanism of such complexes, and the fundamental process such as 30S subunit assembly that determines and controls the overall level of protein biosynthesis. This article describes protocols for preparation of RbfA and the small 30S ribosomal subunits and reconstitution and optimization of the 30S–RbfA complex to obtain samples suitable for cryo-electron microscopy studies

Mechanism of ribosome shutdown by RsfS in Staphylococcus aureus revealed by integrative structural biology approach

© 2020, The Author(s). For the sake of energy preservation, bacteria, upon transition to stationary phase, tone down their protein synthesis. This process is favored by the reversible binding of small stress-induced proteins to the ribosome to prevent unnecessary translation. One example is the conserved bacterial ribosome silencing factor (RsfS) that binds to uL14 protein onto the large ribosomal subunit and prevents its association with the small subunit. Here we describe the binding mode of Staphylococcus aureus RsfS to the large ribosomal subunit and present a 3.2 Å resolution cryo-EM reconstruction of the 50S-RsfS complex together with the crystal structure of uL14-RsfS complex solved at 2.3 Å resolution. The understanding of the detailed landscape of RsfS-uL14 interactions within the ribosome shed light on the mechanism of ribosome shutdown in the human pathogen S. aureus and might deliver a novel target for pharmacological drug development and treatment of bacterial infections