AN ANALYSIS OF TECHNICAL FACTORS AND FINANCIAL EFFICIENCY OF INTEGRATED IMPROVED EXTENSIVE SHRIMP FARMING SYSTEMS IN CA MAU PROVINCE, VIETNAM

The study was conducted from May to September 2020 to evaluate technical factors and the financial efficiency of integrated shrimp farming models. Forty-five inte grated rice-shrimp rotation farming and fortyfive integrated mangrove-shrimp farming households in Ca Mau were subjects of the survey. The results show that farm sizes were relatively large (2.47-5.30 ha). Stocking density was 4.70 ind./m2 (shrimp-rice) and 17.8 ind./m2 (mangrove-shrimp), reaching the productivity of 229.3 and 267.8 kg/ha/crop, respectively. Besides, the rice-shrimp model harvested 1.36 tons/ha/crop of rice and 11.8kg/ha/crop of crab. The mangrove-shrimp model could harvest 69.3kg/ha/crop of crab, 79.3 kg of wild shrimp and 73.5 kg of wild fish. The total production cost for the rice-shrimp model was 6.80 million VND/ha/crop, producing a profit of 33.4 million VND/ha/crop. The mangrove-shrimp model required a production cost at 19.9 million VND/ha/crop and brought a profit of 60.1 million VND/ha/crop. The productivity of shrimp was influenced negatively by stocking density, positively by cultured area (rice-shrimp model), and the ratio of forest area (for mangrove-shrimp model)

Effect of Molecular Charge Asymmetry on Even-to-odd Ratio of High-order Harmonic Generation

Recently, asymmetric molecules, such as HeH$_2^+$, CO, OCS, HCl, have been evolved much attention since its rich information in the high-order harmonic generation (HHG), whose ratio of adjacent even and odd harmonics characterizes the asymmetry of molecules. In this paper, we study the dependence of even-to-odd ratio on the asymmetric parameters, in particular, the nuclear-charge ratio, and the permanent dipole, by exploiting a simple but general model of asymmetric molecules $Z_1Z_2$ subjected to an intense laser pulse. The HHG is simulated by the numerical method of solving the time-dependent Schrödinger equation. We find out that this even-to-odd ratio strongly depends on the nuclear-charge ratio. In particular, the even-to-odd ratio reaches its maximum when the nuclear-charge ratio is about from 0.5 to 0.7. Besides, the dependence on the permanent dipole of the even-to-odd ratio has a non-trivial law. To explain, we calculate the analytical ratio of the transition dipole according to the emission of even and odd harmonics, and this ratio is well consistent with the even-to-odd ratio of the HHG

SOCIAL-EMOTIONAL SKILLS IN STUDENTS’ LEARNING IN CAN THO UNIVERSITY, VIETNAM

Based on an overview of domestic and foreign research related to the research field of the topic; the research of the topic has determined the urgency of the topic, research objectives, research objects and scope, research hypotheses, research tasks, and methods. The research on the topic has systematized the theoretical basis for the concept and manifestation of social-emotional skills in student learning: generalizing the picture of the current situation of recognizing the importance of social-emotional skills in student learning, the level of assessment of the manifestation and educational measures of social-emotional skills in learning, and finding out the factors that affect social emotions in student learning such as from the external environment, at school, family and external social relationships. Factors from the internal environment are the self-awareness of each student. From the current situation of the problem, the study has proposed educational measures for 504 students from 8 schools and colleges in Can Tho University (CTU), Vietnam. Some measures were to educate social-emotional skills for students through soft skills topics, teach soft skills to students through extracurricular activities, and soft skills education for students through integrated teaching.  Article visualizations

Growth and development of transgenic peanut (Arachis hypogaea) lines containing chitinase 42 kDa gene from Trichoderma asperellum SH16

Peanut (Arachis hypogaea L.) is vulnerable to many diseases. Vietnam and other regions where peanut is widely cultivated have a high threat of fungal and other plant diseases. Various fungicides are available to control the fungal disease but these have various harmful effects on the natural flora, fauna, and environment. Transgenic peanut lines which possess antifungal activity provide a possible solution in managing fungal diseases apart from the traditional resistance and fungicide usage. Therefore, this study evaluated the probable growth and development of chitinase transgenic peanut lines against Sclerotium rolfsii, a pathogen that causes “southern blight” in plants, under greenhouse conditions. This study provided evidence that through Agrobacterium itumefaciens mediated transformation, 42 kDa chitinase genes from Trichoderma asperellum, which is under the regulation of 35S promoter, were successfully incorporated into the peanut’s (A. hypogaea L.) genome and expressed in their plants. This evidence also demonstrated that transgenic peanut lines were suitable for growing and developing in the greenhouse. Further, it was reported that transgenic peanut lines took approximately 133 to 145 days from planting to maturity. These results also revealed that various growth characteristics of transgenic peanut lines having two synthetic genes (syncod Chi42-2 i.e. S2-2, S2-4, S2-6, and syncod Chi42-1 i.e. S1-1, S1-2, S1-3) were greater than that from the wild-type Chi42 (WT-1, WT-2, and WT-3). In addition, yield-related parameters including the number of mature pods, 100 pods weight and 100 seeds weight for all the transgenic peanut lines were higher than that of the non-transformed plant. Among the transgenic lines, line S2-4 exhibited significantly higher growth and yield than the other transgenic lines. These results demonstrated that 42 kDa chitinase genes overexpressing peanut lines could be a candidate for improvement against plants to phytopathogenic fungus S. rolfsii and high yield.

Transmission of Japanese Encephalitis (JE) Virus in Gia Luong District, Ha Bac Province, Vietnam, After Je Vaccination, 1993-1994

A total of 15,183 children under 10 years old (37% of target population) was immunized with JE vaccine in Gia Luong District, Ha Bac Province, Vietnam, in 1993 to 1994. JE virus transmission was investigated by swine antibody survey and virus isolation from field mosquitoes. By the hemagglutination inhibition (HI) test, 73-90% of swine were antibody positive all year round, with high geometric mean titer (GMT) of 92.67-95.14 in May and June. By suckling mouse brain inoculation, 6 JE virus strains were isolated from Culex tritaeniorhynchus and Cx. vishuni, as well as laboratory reared F1 from field-caught Cx. tritaeniorhynchus. Serodiganosis by IgM-capture ELISA (MAC-ELISA) carried out on 60 of 85 clinical encephalitis cases detected 43 positives (71.66%). All these serologically confirmed JE cases had not been vaccinated. The results supported the vaccine efficacy to prevent overt JE

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

Age-time-specific transmission of hand-foot-and-mouth disease enterovirus serotypes in Vietnam: a catalytic model with maternal immunity

Hand, foot and mouth disease (HFMD) is highly prevalent in the Asia Pacific region, particularly in Vietnam. To develop effective interventions and efficient vaccination programs, we inferred the age-time-specific transmission patterns of HFMD serotypes enterovirus A71 (EV-A71), coxsackievirus A6 (CV-A6), coxsackievirus A10 (CV-A10), coxsackievirus A16 (CV-A16) in Ho Chi Minh City, Vietnam from a case data collected during 2013–2018 and a serological survey data collected in 2015 and 2017. We proposed a catalytic model framework with good adaptability to incorporate maternal immunity using various mathematical functions. Our results indicate the high-level transmission of CV-A6 and CV-A10 which is not obvious in the case data, due to the variation of disease severity across serotypes. Our results provide statistical evidence supporting the strong association between severe illness and CV-A6 and EV-A71 infections. The HFMD dynamic pattern presents a cyclical pattern with large outbreaks followed by a decline in subsequent years. Additionally, we identify the age group with highest risk of infection as 1-2 years and emphasise the risk of future outbreaks as over 50% of children aged 6-7 years were estimated to be susceptible to CV-A16 and EV-A71. Our study highlights the importance of multivalent vaccines and active surveillance for different serotypes, supports early vaccination prior to 1 year old, and points out the potential utility for vaccinating children older than 5 years old in Vietnam

Assessing the efficacy and safety of magnesium sulfate for management of autonomic nervous system dysregulation in Vietnamese children with severe hand foot and mouth disease.

BACKGROUND: Brainstem encephalitis is a serious complication of hand foot and mouth disease (HFMD) in children. Autonomic nervous system (ANS) dysregulation and hypertension may occur, sometimes progressing to cardiopulmonary failure and death. Vietnamese national guidelines recommend use of milrinone if ANS dysregulation with Stage 2 hypertension develops. We wished to investigate whether magnesium sulfate (MgSO4) improved outcomes in children with HFMD if used earlier in the evolution of the ANS dysregulation (Stage 1 hypertension). METHODS: During a regional epidemic we conducted a randomized, double-blind, placebo-controlled trial of MgSO4 in children with HFMD, ANS dysregulation and Stage 1 hypertension, at the Hospital for Tropical Diseases in Ho Chi Minh city. Study participants received an infusion of MgSO4 or matched placebo for 72 h. We also reviewed data from non-trial HFMD patients in whom milrinone failed to control hypertension, some of whom received MgSO4 as second line therapy. The primary outcome for both analyses was a composite of disease progression within 72 h - addition of milrinone (trial participants only), need for ventilation, shock, or death. RESULTS: Between June 2014 and September 2016, 14 and 12 participants received MgSO4 or placebo respectively, before the trial was stopped due to futility. Among 45 non-trial cases with poorly controlled hypertension despite high-dose milrinone, 33 received MgSO4 while 12 did not. There were no statistically significant differences in the composite outcome between the MgSO4 and the placebo/control groups in either study (adjusted relative risk (95%CI) of [6/14 (43%) vs. 6/12 (50%)], 0.84 (0.37, 1.92), p = 0.682 in the trial and [1/33 (3%) vs. 2/12 (17%)], 0.16 (0.01, 1.79), p = 0.132 in the observational cohort). The incidence of adverse events was similar between the groups. Potentially toxic magnesium levels occurred very rarely with the infusion regime used. CONCLUSION: Although we could not demonstrate efficacy in these studies, there were no safety signals associated with use of 30-50 mg/kg/hr. MgSO4 in severe HFMD. Intermittent outbreaks of HFMD are likely to continue across the region, and an adequately powered trial is still needed to evaluate use of MgSO4 in controlling hypertension in severe HFMD, potentially involving a higher dose regimen. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01940250 (Registered 22 AUG 2013). Trial sponsor: University of Oxford