The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

An Improvement in Welded Joint Using Vibration Assisted Arc Welding

Welding is one of the important processes in mechanical engineering. In engineering sector, welding is a common phenomenon. To improve the quality of joining process, essential changes are necessary in regular welding process. According to the research in welding process, it has been found that vibration can improve mechanical properties of the joining section. However, welding joint quality varies with different ranges of parameters in different conditions. This study has performed to analyze those ranges of parameters in some selected conditions. Here are some input parameters like vibration amplitude, vibration frequency, welding speed and electrode angle are selected to analyze the variation in welded joint. For analyzing the results, output parameters – hardness and deposition rate are calculated. It can be seen that welding process assisted by vibration increases strength and quality of welding joint

An Improvement in Welded Joint Using Vibration Assisted Arc Welding

Welding is one of the important processes in mechanical engineering. In engineering sector, welding is a common phenomenon. To improve the quality of joining process, essential changes are necessary in regular welding process. According to the research in welding process, it has been found that vibration can improve mechanical properties of the joining section. However, welding joint quality varies with different ranges of parameters in different conditions. This study has performed to analyze those ranges of parameters in some selected conditions. Here are some input parameters like vibration amplitude, vibration frequency, welding speed and electrode angle are selected to analyze the variation in welded joint. For analyzing the results, output parameters – hardness and deposition rate are calculated. It can be seen that welding process assisted by vibration increases strength and quality of welding joint