The combination of antimicrobial agents has been proposed as a therapeutic strategy to control bacterial diseases and to reduce the emergence of antibiotic-resistant strains in clinical environments. In this study, the interaction between the lantibiotic bovicin HC5 with chloramphenicol, gentamicin, nisin, lysostaphin and hydrogen peroxide against Staphylococcus aureus O46 was evaluated by MIC assays. The central composite rotatable design (CCRD), a robust and economic statistical design, was used to combine concentration levels of different antimicrobials agents with distinct mechanisms of action and the presence of significant interactions among the antimicrobials was determined by regression analysis. According to the adjusted model, there were no significant interactions between bovicin HC5 and gentamicin, lysostaphin, nisin or hydrogen peroxide. However, bovicin HC5 showed a significant interaction (P < 0.02) with chloramphenicol. This is the first study applying the CCRD approach to evaluate the combined effect of antimicrobials against S. aureus. Based on our results, this approach is an effective strategy to determine synergistic interactions between antimicrobial agents applied in human and veterinary medicine against bacterial pathogens.

Companies seek to improve service level, aiming to meet the most demanding customers that enable it survives in a complex and competitive marketplace. The article presents a study in a company of repair and maintenance of industrial equipment and instruments, located in Campos dos Goytacazes (RJ), aiming to identify the factors that influence the execution time of the operators' activities in the manometer calibration process. For this scope, the study of times and movements and statistical analyzes, such as Linear Regression and ANOVA, were applied. The survey revealed that operators who have completed their technical courses in mechanics perform the activities in standard time greater than those who have not yet completed and that working on board and being married do not change the execution time. It also revealed that employees of lower age and longer experience are preferable because of shorter operating times and that the age was statistically significant, revealing that the most appropriate age to have a shorter time is approximately 27 years.

Em geral, o nitrogênio é o macronutriente requerido em maior quantidade pelas plantas. Para a cultura do sorgo, o nitrogênio também é essencial na formação de proteínas e fundamental no crescimento das plantas. Características agronômicas do sorgo podem ser avaliadas por meio dos requisitos desejáveis do produto em resposta à adubação. Objetivou-se, neste estudo, analisar a resposta de três linhagens de sorgo vassoura a diferentes dosagens de nitrogênio, bem como avaliar a qualidade das panículas para a fabricação de vassouras. O trabalho foi realizado em área experimental localizada no município de Campos dos Goytacazes, RJ. A adubação por cobertura foi realizada com dosagens crescentes de nitrogênio. Observou-se que o uso da adubação nitrogenada proporcionou elevado crescimento das plantas e panículas grandes e pesadas. Essas características não foram desejáveis para a produção de vassouras de qualidades, porque plantas altas estão mais propícias a sofrerem tombamento com aincidência de ventos. Para reduzir custos com adubação de cobertura e alturas menores de plantas, recomenda-se a linhagem L2, por não ser sensível à redução de nitrogênio, ou a L1 para doses de nitrogênio até 90 kg.ha-1 .

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