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

Transfer in Vietnamese-English bilingualism : prosody effects in the interpretation of relative clauses

1 online resource (31 pages) : graphs, chartsIncludes abstract and appendices.Includes bibliographical references (pages 26-28).This thesis examined the interpretation of ambiguous sentences with relative clauses (RCs) in English as a second language (L2). In Jimmy met the brother of the engineer who has a smart dog, the RC who has a smart dog can refer to either the first noun phrase (NP1; the brother) or the second one (NP2; the engineer). Previous research has shown that, although L2 learners of English often transfer their interpretation for these sentences from their first language (L1), they can use prosodic cues, such as pauses, to infer their intended meaning. However, most of the previous studies focused on L1-L2 pairings with different default interpretation preferences. It is unclear what learners’ interpretations are when L1 and L2 have the same default interpretation preference. This thesis addresses this gap by examining how Vietnamese learners of English interpret RCs, using a sentence interpretation task with auditory stimuli. In both Vietnamese and English, the default interpretation is the one where the RC refers to NP2. In the task, participants (16 English native speakers, 15 Vietnamese learners of English) were presented with ambiguous sentences containing RCs recorded in three ways: with no pauses, with a pause after NP1, or with a pause after NP2. While a pause after NP1 is more likely to yield the interpretation that the RC attaches to NP2, a pause after NP2 is more likely to yield the interpretation that the RC attaches to NP1. The results indicate that English native speakers and advanced learners, but not intermediate learners, showed sensitivity to the use of pauses for disambiguation. For sentences with no pauses, both native speakers and learners preferred the interpretation where the RC refers to NP2, consistent with the literature

Recurrent Neural Networks for Oil Well Event Prediction

We have conducted a comparison between three types of recurrent neural networks and their ability to predict anomalies occurring in oil wells using a publicly available dataset. We have included two types of well-known state-of-the-art recurrent neural networks and a new type with neurons evolved specifically for the dataset using automatic programming. We show that the new type of recurrent neuron offers a massive improvement over the state of the art. The overall test accuracy of the new network type is 94.6%, which is an improvement by 18.3%, or 14.6 percentage points. We also show that a network with the new neuron performs better than any other solution proposed for the dataset.publishedVersio

Heat Stress Affects Seed Set and Grain Quality of Vietnamese Rice Cultivars during Heading and Grain Filling Period

Environmental stress trigger a variety of rice plant response, ranging from alters seed set, grain yield and grain quality during flowering and grain filling stage.&nbsp; Efforts are required to improve our understanding of the impact of heat stress on rice production, which are essential strategies in rice cultivation. This article investigated the seed set, yield components and grain yield of Vietnamese rice cultivars (Indica germplasm) under high temperature environment during the flowering and grain filling stage. Six rice cultivars, including popular cultivars and new cultivars of Cuu Long Delta Rice Research Institute, and one popular extraneous cultivar with differences in maturing time, were grown in pots at high temperature (HT) and natural temperature condition as control (CT). All rice cultivars were subjected to the high temperature starting from the heading stage to the harvest maturity, applied by greenhouse effect. The greenhouse has about 25 cm window opening on 3 sides for air ventilation. The seed set rate of the heat-sensitive rice genotypes decreased significantly under HT, leading to a significant reduction in grain yield. The lowest seed set was recorded in “OM4900” (44.3%) and “OM18” (39.9%) under high temperature environment. The lower yield in all rice cultivars at an elevated temperature resulted in a dramatic decrease of filled grains and contributed to a loss of 1000-grain weight. ‘“OM892” is a potential rice cultivar for heat tolerant breeding program due to the seed set percentage was above 80% in both HT and CT conditions. High temperature during the grain filling stage resulted in a decreased amylose and increased chalkiness for all OM cultivars

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

THE RELATIONSHIPS BETWEEN STUDENTS’ SELF-CONFIDENCE AND THEIR ENGLISH-SPEAKING PERFORMANCE: A CASE STUDY OF ENGLISH-MAJORED STUDENTS AT A PRIVATE UNIVERSITY IN VIETNAM

This research aimed to discover the relationships between students' self-confidence and their English-speaking performance. In our research, self-confidence was divided into three components which are affective confidence, behavioral confidence, and cognitive confidence. In addition, speaking performance included eight components which are vocabulary, grammar, pronunciation, fluency, coherence, comprehension, task, and content. A sample of 150 English-majored students at a university in Vietnam was surveyed in this study by using a convenience sampling technique, and then conducting semi-structured interviews to seek for qualitative information from 10 participants out of 150. The result from our study showed that there are significant relationships between the two variables. The more confident the students are, the more accomplished they would be in the presenting procedure since they have superior cognition and understand how to modify their learning methods to build a comprehensive individual in learning English language. We expect that these findings can help students adjust their learning methods to improve their self-confidence as well as English speaking performance and by that way, universities can add more speaking-related subjects so that students can have more opportunities to speak and learn more speaking skills.  Article visualizations

Dynamic association between energy transition technologies, renewable energy production, trade openness, green investment, carbon tax, and carbon neutrality: empirical evidences from China

The existing millennium documents the most adverse consequences of global warming which in contrast to pre-industrial era are more devastating. Thus, these prevailing consequences raise numerous concerns regarding the well-being of future and current generation. Scholars, in this regard, are putting efforts punctiliously towards methods that could halt the surging emissions. This paper also attempts to contributes to existing literature by reporting the empirical evidences regarding the role of energy transition technologies, renewable energy production (REP), trade openness, green investment, and carbon taxes in carbon neutrality in Chinse economy covering the time span of 1980–2020. By employing Dynamic Auto-regressive Distributed Lags (DARDL) model to check the association, findings exposed that electricity production from water sources, electricity production from solar sources, REP, trade openness, green investment, and carbon taxes are negatively correlated with CO2 emissions. Study offers policymakers a help in formulating policies related to achieve carbon neutrality using renewable sources of energy production, carbon taxes, and green investmen

WATER ENVIRONMENT AND POLLUTION OF HUONG RIVER IN HUE CITY, CENTRAL VIETNAM

Joint Research on Environmental Science and Technology for the Eart

Groundwater recharge in Mekong River Delta: An application of the water-table fluctuation method in the Long Xuyen Quadrangle and the Ca Mau Peninsula

Local groundwater recharge was determined using the Water Table Fluctuation method in the Long Xuyen Quadrangle and the Ca Mau Peninsula to refine existing estimates in a range of aquifer lithologies in light of climate change. The approach takes advantage of long term monthly water level records of Vietnam by Division of Water Resources Planning and Investigation for the South of Vietnam. An analysis of water levels in eight observation wells during four climatically distinct years (2005, 2009, 2013, and 2020) was used in combination with the monthly meteorological data. Groundwater recharge was estimated by the Water Table Fluctuation method to vary from 95.7 to 150.4 mm/year and account for 5.3 to 7.5% of the total rainfall. The estimates fall within the range of values used in regional-scale recharge models and demonstrate the potential of the Water Table Fluctuation method for resolving spatial and temporal variations of groundwater recharge

Impact of Educational Intervention Concerning Awareness and Behaviors Relating to Avian Influenza (H5N1) in a High-Risk Population in Vietnam

BACKGROUND: Early initiation of treatment is essential for treatment of avian influenza A/H5N1 viral infection in humans, as the disease can lead to rapid development of severe pneumonia which can result in death. Contact with infected poultry is known to be a significant risk factor for contraction of H5N1 infection. However, handling and encountering poultry are a part of most peoples' daily lives, especially in rural communities in Vietnam where epidemic outbreaks among poultry have been continuously reported. Enhancing proper knowledge relating to H5N1 and to the importance of early initiation of treatment are crucial. The aim of this study was to develop an effective educational program to enhance awareness of H5N1 and motivate people to access to health care earlier when H5N1 infection is suspected or likely. METHODOLOGY AND PRINCIPAL FINDINGS: A study was conducted in two agricultural communities (intervention and control groups) in the Ninh Binh province in Vietnam, where epidemic outbreaks of avian influenza have recently occurred in birds. A unique educational intervention was developed and provided to the intervention group, and no intervention was provided to the control group. A knowledge, attitude and practice (KAP) survey was conducted in both groups with a face-to-face interview by trained local healthcare workers at time points before and after the educational intervention. KAP scores were compared between the different time points and between the groups. How educational intervention influenced awareness relating to H5N1 and accessibility of healthcare in the population was analyzed. The study indicated an increased awareness of H5N1 and increased reliance on local health care workers. CONCLUSIONS: The novel educational program which was developed for this study impacted awareness of H5N1, and resulted in more people seeking early access to healthcare, and also resulted in earlier medical intervention for patients with H5N1 avian influenza infection in Vietnam