Antimicrobial Resistance in <i>Salmonella enterica</i> Typhi in Asia

Antimicrobial resistance is a major problem in the treatment of typhoid fever; a systemic human infection caused by Salmonella Typhi (S. Typhi). The co-existence of multidrug resistant and fluoroquinolone resistant S. Typhi isolates is increasingly common. Therefore, it is essential to understand the molecular mechanisms and the epidemiology of antimicrobial resistant S. Typhi in endemic countries such as Viet Nam. A cross section of S. Typhi strains isolated from 8 Asian countries and a Vietnamese S. Typhi collection were investigated for antimicrobial resistance patterns. Molecular approaches were used to identify the mechanisms of (fluoro)quinolone resistance in S. Typhi isolates. Specific phenotypic characteristics of each of the naturally mutations were assessed in S. Typhi isolates that were reconstructed in an isogenic strain. The antimicrobial resistance phenotypes of both wild type and reconstructed mutants were calculated using antimicrobial susceptibility tests and time-kill experiments. To predict the relative fitness of these mutants, the strains were subjected to independent and competitive growth assays. Finally, we developed a molecular epidemiological tool which was used to genotype and identify fluoroquinolone resistant S. Typhi strains circulating in Asia. The findings of this study show that antimicrobial resistant S. Typhi is continuing problem in Asian countries, especially in Viet Nam. Fluoroquinolone resistance in S. Typhi is caused by mutations in specific locations of the gyrA and parC genes. The majority of reconstructed mutants had a selective growth advantage when placed in competition with a non-mutant S. Typhi strain. Strains that had the highest level of fluoroquinolone resistance had a selective disadvantage. We conclude that S. Typhi haplotype H58 with associated nalidixic acid resistance is dominant across Asian countries

Exploring Cloud Adoption Possibilities for the Manufacturing Sector: A Role of Third-Party Service Providers

As the manufacturing sector strides towards digitalization under the influence of Industry 4.0, cloud services have emerged as the new norm, driving change and innovation in this rapidly transforming landscape. This study investigates the possibilities of cloud adoption in the manufacturing sector by developing a conceptual model to identify suitable cloud-based solutions and explores the role of third-party service providers in aiding manufacturers throughout their cloud adoption journey. The research methods consist of a comprehensive literature review of the manufacturing industry, digital transformation, cloud computing, etc., followed by qualitative analyses of industrial benchmarks case studies and an investigation into an application of the developed model to a hypothetical food manufacturing company as an example. This study indicates that cloud adoption can yield substantial benefits in the manufacturing sector, including operational efficiency, cost reduction, and innovation, etc. The study concludes that the developed conceptual model provides a practical framework to identify the most suitable cloud-based solutions during the cloud adoption process in the manufacturing context. In addition, third-party service providers like Capgemini are capable of not only filling the technical gaps but also consulting strategic directions and innovations for their client organizations, hence playing a vital role in driving the industrial digital transformation process. With an extensive mapping of their capabilities, a set of recommendations intended to assist Capgemini in enhancing capabilities and improving competitive performance in the market has been offered

Are anonymity-seekers just like everybody else? An analysis of contributions to Wikipedia from Tor

User-generated content sites routinely block contributions from users of privacy-enhancing proxies like Tor because of a perception that proxies are a source of vandalism, spam, and abuse. Although these blocks might be effective, collateral damage in the form of unrealized valuable contributions from anonymity seekers is invisible. One of the largest and most important user-generated content sites, Wikipedia, has attempted to block contributions from Tor users since as early as 2005. We demonstrate that these blocks have been imperfect and that thousands of attempts to edit on Wikipedia through Tor have been successful. We draw upon several data sources and analytical techniques to measure and describe the history of Tor editing on Wikipedia over time and to compare contributions from Tor users to those from other groups of Wikipedia users. Our analysis suggests that although Tor users who slip through Wikipedia's ban contribute content that is more likely to be reverted and to revert others, their contributions are otherwise similar in quality to those from other unregistered participants and to the initial contributions of registered users.Comment: To appear in the IEEE Symposium on Security & Privacy, May 202

Temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of Vietnam.

BACKGROUND: typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi), which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina) assay to type 1,500 single nucleotide polymorphisms (SNPs) and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005. PRINCIPAL FINDINGS: the population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Sông H u branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene. SIGNIFICANCE: the H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2) observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam

An implementation of rotor speed observer for sensorless induction motor drive in case of machine parameter uncertainty

The paper describes observers using model reference adaptive system for sensorless induction motor drive with the pulse width modulator and the direct torque control under the circumstances of incorrect information of induction motor parameters. An approximation based on the definition of the Laplace transformation is used to obtain initial values of the parameters. These values are utilized to simulate sensorless control structures of the induction motor drive in Matlab-Simulink environment. Performance comparison of two typical observers is carried out at different speed areas and in presence of parameter uncertainty. A laboratory stand with the induction motor drive and load unit is set up to verify the properties of observers. Experimental results confirm the expected dynamic properties of selected observer

TEACHERS’ PERCEPTIONS OF SCAFFOLDING EFL STUDENTS’ READING COMPREHENSION AT HIGH SCHOOLS IN THE MEKONG DELTA, VIETNAM

Scaffolding has held great appeal for teachers of English as a foreign language (EFL) and scholars in helping students take greater responsibility or ownership in their language learning and reach academic success. However, little is known about how teachers perceived this type of support as improving students’ reading comprehension in English within the teaching and learning context in Vietnam high schools. This paper therefore reports a descriptive study that explored teachers’ perceptions of scaffolding EFL students’ reading comprehension at high schools in the Mekong Delta, Vietnam. Questionnaires and semi-structured interviews were employed to collect data from seventy-nine high school teachers. The findings provide insightful views into teachers’ perceptions about scaffolding students’ reading comprehension. The findings also reveal how teachers experienced varying degrees of their perceptions of scaffolding and challenges while delivering their scaffolding practices in reading instruction. Article visualizations