Mathematical Simulations of Deformation for the Rotation Shells with Variable Wall Thickness

Well-posed boundary value problems are constructed for calculating rotation shells of with a stiffness variable along the meridian in two directions, and also with variable bilateral with respect to the reference surface with the shell wall thickness. Algorithms for the numerical integration of systems of differential equations with variable coefficients are discussed.Well-posed boundary value problems are constructed for calculating rotation shells of with a stiffness variable along the meridian in two directions, and also with variable bilateral with respect to the reference surface with the shell wall thickness. Algorithms for the numerical integration of systems of differential equations with variable coefficients are discussed

Complete genome sequence and epigenetic profile of Bacillus velezensis UCMB5140 used for plant and crop protection in comparison with other plant-associated Bacillus strains

The application of biocontrol biopesticides based on plant growth–promoting rhizobacteria (PGPR), particularly members of the genus Bacillus, is considered a promising perspective to make agricultural practices sustainable and ecologically safe. Recent advances in genome sequencing by third-generation sequencing technologies, e.g., Pacific Biosciences’ Single Molecule Real-Time (PacBio SMRT) platform, have allowed researchers to gain deeper insights into the molecular and genetic mechanisms of PGPR activities, and to compare whole genome sequences and global patterns of epigenetic modifications. In the current work, this approach was used to sequence and compare four Bacillus strains that exhibited various PGPR activities including the strain UCMB5140, which is used in the commercial biopesticide Phytosubtil. Whole genome comparison and phylogenomic inference assigned the strain UCMB5140 to the species Bacillus velezensis. Strong biocontrol activities of this strain were confirmed in several bioassays. Several factors that affect the evolution of active PGPR B. velezensis strains were identified: (1) horizontal acquisition of novel non-ribosomal peptide synthetases (NRPS) and adhesion genes; (2) rearrangements of functional modules of NRPS genes leading to strain specific combinations of their encoded products; (3) gain and loss of methyltransferases that can cause global alterations in DNA methylation patterns, which eventually may affect gene expression and regulate transcription. Notably, we identified a horizontally transferred NRPS operon encoding an uncharacterized polypeptide antibiotic in B. velezensis UCMB5140. Other horizontally acquired genes comprised a possible adhesin and a methyltransferase, which may explain the strain-specific methylation pattern of the chromosomal DNA of UCMB5140.The South African National Research Foundation (NRF), the joint NRF/COSTECH (Tanzanian Commission for Science and Technology), joint TIA (Technology Innovation Agency of South Africa)/COSTECHPhD and MSc student fellowship grants from Southern African Biochemistry and Informatics for Natural Products (SABINA, http://www.sabina-africa.org/) and Agroscope through its research program Microbial Biodiversity.http://link.springer.com/journal/2532021-07-10hj2020BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

The ecology and evolutionary dynamics of meiotic drive

Meiotic drivers are genetic variants that selfishly manipulate the production of gametes to increase their own rate of transmission, often to the detriment of the rest of the genome and the individual that carries them. This genomic conflict potentially occurs whenever a diploid organism produces a haploid stage, and can have profound evolutionary impacts on gametogenesis, fertility, individual behaviour, mating system, population survival, and reproductive isolation. Multiple research teams are developing artificial drive systems for pest control, utilising the transmission advantage of drive to alter or exterminate target species. Here, we review current knowledge of how natural drive systems function, how drivers spread through natural populations, and the factors that limit their invasion