The ColR/S two-component system is a conserved determinant of host association across Pseudomonas species

Members of the bacterial genus Pseudomonas form mutualistic, commensal and pathogenic associations with diverse hosts. The prevalence of host association across the genus suggests that symbiosis may be a conserved ancestral trait and that distinct symbiotic lifestyles may be more recently evolved. Here we show that the ColR/S two-component system, part of the Pseudomonas core genome, is functionally conserved between Pseudomonas aeruginosa and Pseudomonas fluorescens. Using plant rhizosphere colonization and virulence in a murine abscess model, we show that colR is required for commensalism with plants and virulence in animals. Comparative transcriptomics revealed that the ColR regulon has diverged between P. aeruginosa and P. fluorescens and deleting components of the ColR regulon revealed strain-specific, but not host specific, requirements for ColR-dependent genes. Collectively, our results suggest that ColR/S allows Pseudomonas to sense and respond to a host, but that the ColR-regulon has diverged between Pseudomonas strains with distinct lifestyles.

On the S-25 anti-aircraft missile system. Part 1

The paper introduces and analyzes the results of research into the development of anti-aircraft missile systems through the example of the first Russian anti-aircraft missile system S-25. The study describes the capabilities of the anti-aircraft missile system as the implementation of the requirements specifications in the context of the development of military aviation technology and electronic warfare means and emphasizes the importance of cooperation between enterprises — developers of guided missile weapons. Although the latter issue is poorly covered in the Russian scientific, technical, and educational literature, it is an important problem in organizing the development of missile systems. The paper is the first to provide detailed data on the content and timing of the stages of modernization of the S-25 system, and also presents graphic material that clearly demonstrates the change in the capabilities of the S-25 system due to an intensive change in the characteristics of military aircraft.