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Abstract In this paper, we study the formation of optical bistability (OB) and optical multistability (OM) in a degenerate four-level atomic system by an external magnetic field that is excited by a probe laser field, a coupling laser field and a signal laser field. The coupling field can cause electromagnetically induced transparency (EIT) for the probe field in the atomic medium, while the signal field and/or external magnetic field can switch between single-EIT and two-EIT regimes. Based on these properties, OB and OM effects can be formed at two different frequency regions of the probe field (two channels). By adjusting the magnetic field or the intensity and the frequency of laser fields, the threshold intensity and the width of OB or OM can also be changed simply. The model can be useful for experimental observations and applications in modern photonic devices.

Abstract Background Helicobacter pylori eradication therapy based on antimicrobial susceptibility in Vietnamese children currently get low efficiency. There are causes of treatment failure, among host genetic factors namely MDR1 C3435T and CYP2C19 affect the absorption and metabolism of proton pump inhibitors - a crucial component of eradication therapy. The study aimed to investigate the effect of MDR1 C3435T and CYP2C19 genetic polymorphisms on the cure rate. Methods 207 pediatric patients with gastritis and peptic ulcer infecting Helicobacter pylori completed the eradication therapy based on antimicrobial susceptibility with proton pump inhibitor esomeprazole. Eradication efficacy was assessed after at least 4 weeks by the urease breath test. MDR1 C3435T genetic polymorphism and CYP2C19 genotype were determined using a sequencing method based on Sanger’s principle. Results Among 207 children recruited in this study, the ratio of CYP2C19 EM, IM, and PM phenotypes was 40.1%, 46.4%, and 16.9%, respectively. The patient with MDR1 3435 C/C polymorphism accounted for 43.0%, MDR1 3435 C/T was 40.1%, and MDR1 3435T/T was 16.9%. The cure rate of Helicobacter pylori infection in patients with CYP2C19 EM genotype was 78.3%; 83.3% of those with the IM genotype, and PM genotype was 96,4% (p = 0.07). Successful eradication rates for Helicobacter pylori were 85.4%, 86.7%, and 68.6% in patients with the MDR1 3435 C/C, C/T, and T/T, respectively (p = 0.02). Multiple logistic regression analysis found that MDR1 C3435T genetic polymorphisms of patients were significant independent risk factors for treatment failure, and CYP2C19 genotype did not affect Helicobacter pylori eradication. Conclusions The Helicobacter pylori eradication rates by regimens based on antibiotic susceptibility and esomeprazole were not significantly different between the CYP2C19 phenotypes. The MDR1 C3435T polymorphism is one of the factors impacting Helicobacter pylori eradication results in children.

Objective: Obesity is a complex disease that involves interactions between environmental and genetic factors in its pathogenesis. The aims of this present study were to analyse the overall effects of some nutritional, physical and genetic factors with childhood obesity, and to build predictive models of childhood obesity. Material and Methods: A case-control study was conducted on 559 Hanoi primary school children (278 obese cases and 281 normal controls). Genetic analysis was performed to evaluate genotype on the rs6265 gene BDNF, rs6548238 gene TMEM18, rs6499640 gene FTO, and rs17782313 gene MC4R. Univariate and multivariate regression analysis were conducted to compare the two groups of children, so as to draw conclusions regarding influencing factors and to establish predictive models of obesity for Hanoi primary school children. Results: Factors increasing the risk of obesity found included: urban living areas (odds ratio (OR)=1.5), caesarean section (OR=2.1), high birth weight (OR=1.9-3.1), parental overweight and obesity (OR=2.1-5.1), short night sleeping times (OR=2.6), characteristics of child feeding; including early weaning (OR=2.1), gluttony (OR=19.1), no snacking (OR=2.4), controlled eating (OR=2.4) fat food hobbies (OR=2.7), and CC rs6548238-TMEM18 genotype (OR=1.8). A predictive model of childhood obesity for Hanoi primary school children was built, based on the BMI of parents, gluttonous characteristics, unrestricted eating with ROC=0.871. Conclusion: Childhood obesity develops as a result of interaction between eating habits, lifestyle characteristics of the child and genetic characteristics inherited from over nutritious parents. Encouraging parents to manage both their own weight and their children’s eating habits such as allowing children to consume food without undue restriction and reducing gluttony can serve as effective interventions to diminish the prevalence of childhood obesity within the community.

The aim of this study was to investigate the factors influencing Body Fat Percentage (BFP) among Vietnamese adolescents aged 11 to 15 employing machine learning techniques for predictive analysis. A total of 1,208 adolescents, comprising 598 boys and 610 girls, drawn from nine junior high schools in Vietnam's capital, were enrolled in the study. Body composition measurements were conducted using the HBF 375 (Omron) device by Bioelectrical Impedance Analysis method. The study questionnaire, initially validated by The National Institute of Nutrition, encompassed inquiries related to dietary behaviors, meal frequencies, physical activities, sedentary habits, and nutritional knowledge. A machine learning methodology employing a decision tree algorithm was employed to discern the primary determinants most significantly correlated with BFP. This study successfully identified six distinct predictor groups associated with BFP among adolescents, leveraging the decision tree model, with Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE) values of 4.80 and 3.80, respectively. Among these predictors, frequency of fruit consumption, snacking habits, mode of transportation to school, and screen time (computer and/or cell phone usage) emerged as the most influential factors linked to BFP in adolescents. The combination of these factors and interactions with gender and pubertal status can BFP in Vietnamese adolescents. This research sheds light on the complex and diverse factors impacting BFP in Vietnamese adolescents. This study's results underscore the practical importance of promoting healthy eating and exercise habits among adolescents, offering valuable insights for parents and schools to enhance their childcare strategies.

AbstractUsing the GJR-GARCH method, this study examines the safe-haven role of gold, US dollar, and Bitcoin over a period including the global financial crisis, the COVID-19 pandemic and the Russia-Ukraine conflict from 3 April 2006 to 19 May 2023. The study supports the hypothesis that the safe-haven role of assets changes over periods of crisis. Specifically, gold loses its role as a safe-haven asset during the COVID-19 pandemic, but this role has been restored in the Dutch, US and German markets during the Russia-Ukraine conflict. Similarly, Bitcoin is not a safe-haven asset during the COVID-19 pandemic but is a strong safe-haven asset for the stock markets of some European countries, and a weak safe-haven asset for China when the Russia-Ukraine conflict occurred. Only the USD acts as a stable safe-haven asset through periods of crisis. However, this role is weakened in Russia. These results partly help investors and portfolio managers choose a safe haven for their assets, especially during volatile market periods.

Vietnam is a rapidly developing country associated with changes in socio-economic activities, especially both public and private services. The service industry is making a practical contribution to economic growth and is gaining a great position. To help a society develop harmoniously, the economy must satisfy people's ability to access services, especially basic services such as education, healthcare, legality, transportation, security and safety. The aims of the study are to estimate factors affecting legal service quality, and based on the survey in three provinces in Vietnam: Lam Dong, Dak Lak, Gia Lai and through quantitative analysis, the research results show that there are five factors that positively affect service quality, which are: (1) government; (2) head of the unit; ⁠(3) influencer; (4) opinions of people around; and (5) organizations and individuals providing services. The research results also discuss some solutions to increase service quality and sustainable development of Vietnam in the coming time.

Background: Hypertrophic cardiomyopathy (HCM) is a primary cardiac disorder characterized by myocardial hypertrophy without increased afterload. This study set out to describe the cardiac magnetic resonance (CMR) imaging characteristics of HCM and to evaluate correlations of selected CMR parameters with echocardiography. Methods: This cross-sectional study enrolled 46 patients diagnosed at the Vietnam Heart Institute with HCM and underwent CMR at the Radiology Center, Bach Mai Hospital, from July 2021 to September 2022. Results: A left ventricular outflow tract (LVOT)/aortic valve (AO) diameter ratio of ≥0.38 on CMR was consistent with an LVOT pressure gradient (PG) of

Small wind turbines operating in low wind speed regions have not had any significant success. In addition, small wind speed regions occupy a large area of the world, so they represent a potential area for installing small wind turbines in the future. In this paper, a method to design an efficient airfoil for small wind turbines in low wind speed conditions using XFLR5 and CFD simulations is implemented. Because the impact of the airflow on the blade surface under low Re number conditions can change suddenly for small geometries, designing the airfoil shape to optimize the aerodynamic performance is essential. The tuning of the key geometric parameters using inversion techniques for better aerodynamic performance is presented in this study. A two-dimensional model was used to consider the airflow on the airfoil surface with differences in the angle of attack. The original S1010 airfoil was used to design a new airfoil for increasing the aerodynamic efficiency by using V6.57 XFLR5 software. Subsequently, the new VAST-EPU-S1010 airfoil model was adjusted to the maximum thickness and the maximum thickness position. It was simulated in low wind speed conditions of 4–6 m/s by a computational fluid dynamics simulation. The lift coefficient, drag coefficient, and CL/CD coefficient ratio were evaluated under the effect of the angle of attack and the maximum thickness by using the k-ε model. The simulation results show that the VAST-EPU-S1010 airfoil achieved the greatest aerodynamic efficiency at an angle of attack of 3°, a maximum thickness of 8%, and a maximum thickness position of 20.32%. The maximum value of CL/CD of the new airfoil at 6 m/s was higher than at 4 m/s by about 6.25%.

This article presents a research approach to enhancing the quality of short-term power output forecasting models for photovoltaic plants using a Long Short-Term Memory (LSTM) recurrent neural network. Typically, time-related indicators are used as inputs for forecasting models of PV generators. However, this study proposes replacing the time-related inputs with clear sky solar irradiance at the specific location of the power plant. This feature represents the maximum potential solar radiation that can be received at that particular location on Earth. The Ineichen/Perez model is then employed to calculate the solar irradiance. To evaluate the effectiveness of this approach, the forecasting model incorporating this new input was trained and the results were compared with those obtained from previously published models. The results show a reduction in the Mean Absolute Percentage Error (MAPE) from 3.491% to 2.766%, indicating a 24% improvement. Additionally, the Root Mean Square Error (RMSE) decreased by approximately 0.991 MW, resulting in a 45% improvement. These results demonstrate that this approach is an effective solution for enhancing the accuracy of solar power output forecasting while reducing the number of input variables.

This cross-sectional study aimed to evaluate the nutritional status of 24–60-month-old children in Hanoi, Vietnam, and explore parents’ perception of their child's body shape, as well as related factors. The study found that parents’ wishes had a significant impact on their children’s nutritional status, as reflected in the high percentage of parents dissatisfied with their child’s weight and shape. Malnutrition, overweight, and obesity were defined based on WHO 2006 standards, and children's anthropometric indices were measured. A self-reported questionnaire was used to collect information on parents’ perception of their child’s health based on body shape and their satisfaction with it. The results showed highest dissatisfaction with the child's shape in malnourished children (86.8 %), then in the obese group (60.4 %), and lowest in overweight children (28 %). Correct parental perception about the child’s nutritional status and the healthiest shape was only 61.1 % and 34.5 %, respectively. Several related factors to parental correct perception about the child’s shape was found and it was higher 22.5 % with the parent living in suburban area than those living in urban area, 20 % with the parent of girls than those of boys, it decreased to 54 % in group of malnourished children, and 66 % in group of obese and overweight children. The findings of this study highlight the importance of parental education on healthy child development and the need for interventions to address the high prevalence of malnutrition, overweight, and obesity in preschool children.

Peer observation is considered as a useful tool to enhance teachers’ professional development. Limited research on how peer observation is carried out in Vietnamese higher institutions and how teachers experience peer observation in their educational contexts. This study investigates the experiences of peer observation among Vietnamese teachers of English and their perceptions of the benefits and challenges of peer observation. The study employed a quantitative research method to collect data. Survey questionnaires were completed online via Google Forms by 22 teachers of English working in different universities and colleges in Ho Chi Minh City. The findings show that teachers’ perceptions and experiences of peer observation varied among academic institutions. The purposes of peer observation were different among different educational settings. Peer observation sessions tend to focus more on evaluation purposes than on professional development purposes which aim to improve the teaching performance of EFL teachers. Also, the procedures for implementing peer observation were not unanimous among academic institutions. The findings have several implications for stakeholders to reflect on the current practices of peer observation in their respective institutions with a view to improving the quality of this professional development tool to enhance English language teachers’ professional development.

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.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Despite the substantial role that chickens have played in human societies across the world, both the geographic and temporal origins of their domestication remain controversial. To address this issue, we analyzed 863 genomes from a worldwide sampling of chickens and representatives of all four species of wild jungle fowl and each of the five subspecies of red jungle fowl (RJF). Our study suggests that domestic chickens were initially derived from the RJF subspecies Gallus gallus spadiceus whose present-day distribution is predominantly in southwestern China, northern Thailand and Myanmar. Following their domestication, chickens were translocated across Southeast and South Asia where they interbred locally with both RJF subspecies and other jungle fowl species. In addition, our results show that the White Leghorn chicken breed possesses a mosaic of divergent ancestries inherited from other subspecies of RJF. Despite the strong episodic gene flow from geographically divergent lineages of jungle fowls, our analyses show that domestic chickens undergo genetic adaptations that underlie their unique behavioral, morphological and reproductive traits. Our study provides novel insights into the evolutionary history of domestic chickens and a valuable resource to facilitate ongoing genetic and functional investigations of the world's most numerous domestic animal.

This article studies the linkage between financial inclusion, monetary policy and financial stability in 58 countries including 31 high financial development countries (HFDCs) and 27 low financial development countries (LFDCs) from 2004 to 2020 using the PVAR method. Results of impulse – response function suggest that in LFDCs, while financial inclusion and financial stability are positively correlated, they are negatively correlated with the inflation rate and the money supply growth rate. In HFDCs, financial inclusion is positively corelated with inflation rate and money supply growth rate, while financial stability is negatively correlated with financial inclusion, inflation rate and money supply growth rate. These findings imply that in LFDCs, financial inclusion increases financial stability and reduces inflation. In HFDCs, on the contrary, financial inclusion increases financial instability, leading to long-term inflation. The results of the variance decomposition confirm the above outcomes, specifically, this relationship is clearer in HFDCs. From the above findings, we propose some policy recommendations on financial inclusion and monetary policy for financial stability for each group of countries.

The desired performance of nucleic acid testing (NAT) may vary if used for disease diagnosis or for the evaluation of the therapeutic efficacy of a treatment, although in most cases, the same assay is used. However, these tests may not be affordable in many situations including in low/middle income countries that in response have developed domestic assays. Given the example of HCV NAT among people who inject drugs in Vietnam, we aimed at evaluating a domestic assay versus an FDA- and CE-approved assay. This cross-evaluation revealed that (i) the domestic assay had a poorer sensitivity with a threshold of detection above 104 IU/mL, and (ii) the FDA-approved assay had a percentage of false negative results close to 1%. Together, in the present study, the domestic assay had a performance compatible with diagnosis purposes (given that this population was 70% HCV seropositive) but not compatible with HCV treatment monitoring (given that treatment failures are rare and the observed viremia frequently below the threshold of detection). This study highlights the need for a proper evaluation of HCV RNA domestic assays in order to efficiently contribute to the WHO HCV elimination target by 2030.