A model of mother tongue-based bilingual education in Vietnam: Achievements and lessons learnt

This articlesummarizes findings from the implementation of the mother tongue-based bilingual education model and the tracer study on the students who participated in the mother tongue-based bilingual education program at preschool and primary schools and transitioned to higher levels of education in the framework of the UNICEFfunded "Learning for children" project. The research team would like to thank UNICEF Viet Nam,the Vietnam National Institute of Educational Sciences, Departments of Education and Training of Lao Cai, Gia Lai and Tra Vinh provinces, and educational managers, teachers and students in the three provinces for their support and cooperation.Education practices in ethnic minority areas in Vietnam with regional and ethnic differences influence its educational development. In particular, the language difference is a factor because the language used in teaching and learning is Vietnamese, not the mother tongue. Therefore, the mother tonguebased bilingual education model was developed to provide quick and convenient access to Vietnamese (the nation’s official language) and knowledge for students in ethnic minority areas. Its approach is to use the ethnic students’ mother tongues as the initial foundation in their first schooling years. The outstanding results of the successfully tested model have contributed to the improvement of the quality of ethnic minority education in Vietnam

KẾT QUẢ BƯỚC ĐẦU NGHIÊN CỨU TỐC ĐỘ LẮNG ĐỌNG, NGUỒN TRẦM TÍCH ĐÁY VỊNH HẠ LONG: DẤU HIỆU TỪ KHOÁNG VẬT SÉT, ĐỒNG VỊ 210Pb VÀ 137Cs

Ha Long bay is the World Natural Heritage, which annaually attracts a lot of foreign and domestic tourists. Nevertheless, in recent years, the landscape of Ha Long bay is devastated by many negative impacts-the shallowing of the bottom of bay is one of the great negative impacts. How is the shallowing of the bottom of Ha Long bay? What are reasons for the negative impacts? Based on the approach “source-to-sink” combined with results of clay mineral contents, results of 210Pb and 137Cs radionuclides, this study will contribute to clarifying the shallowing of the bottom of Ha Long bay. Results of smectite, illite and smectite/(illite+chlorite) ratios indicated that the sediment in Ha Long bay not only derives from the surrounding region of Ha Long bay but also derives from Red river system. Results of 210Pbex and 137Csex revealed the sedimentation rates in the Ha Long bay have varied between 0.47 - 0.75 cm/year over the last 100 years. It can be divided into four periods: period I (1920 - 1930); period II (1930 - 1960); period III (1960 - 1990); and period IV (1990 - 2011) with the average rate of 0.45 cm/year; 0.66 cm/year; 0.50 cm/year; and 0.85 cm/year respectively. The shallowing of the bottom of Ha Long bay was impacted by human activities such as building reservoirs, mining, urbanization or aquaculture etc.Vịnh Hạ Long là một trong những di sản thiên nhiên thế giới, hàng năm, vịnh thu hút nhiều du khách trong và ngoài nước. Tuy nhiên, trong những năm gần đây, cảnh quan vịnh bị tác động bởi hàng loạt các tác động tiêu cực - bồi lắng đáy vịnh là một trong những tác động tiêu cực lớn. Đáy vịnh Hạ Long bồi cạn ra sao? nguyên nhân nào gây ra? Theo cách tiếp cận từ nguồn cung cấp đến bồn lắng đọng trầm tích “source-to-sink” và phối hợp với kết quả thành phần khoáng vật sét và đồng vị phóng xạ 210Pb và 137Cs, nghiên cứu này sẽ góp phần là sáng tỏ vấn đề trên. Kết quả hàm lượng smectite, illite và chỉ số smectite/( illite+chlorite) chỉ thị: trầm tích chuyển vào vịnh Hạ Long không chỉ nhận từ vùng xung quanh vịnh mà nó còn nhận từ hệ thống sông Hồng. Kết quả 210Pb và 137Cs cho thấy: tốc độ lắng đọng trầm tích tại vịnh Hạ Long trong vòng 100 năm qua, dao động trong khoảng 0,47 - 0,75 cm/năm, và có thể chia làm 4 giai đoạn: giai đoạn I (từ năm 1920 - 1930), giai đoạn II (từ năm 1930 - 1960); giai đoạn III (1960 - 1990) và giai đoạn IV (từ năm 1990 - 2011) với tốc độ lắng đọng trung bình lần lượt là 0,45 cm/năm; 0,66 cm/năm; 0,50 cm/năm; và 0,85 cm/năm tương ứng. Các hoạt động của con người như: xây hồ chứa, khai thác mỏ, đô thị hóa, nuôi trồng thủy sản ... là nguyên nhân gây bồi cạn đáy vịnh

Kinetics of cardiovascular and inflammatory biomarkers in paediatric dengue shock syndrome

Glycocalyx disruption and hyperinflammatory responses are implicated in the pathogenesis of dengue-associated vascular leak, however little is known about their association with clinical outcomes of patients with dengue shock syndrome (DSS). We investigated the association of vascular and inflammatory biomarkers with clinical outcomes and their correlations with clinical markers of vascular leakage. We performed a prospective cohort study in Viet Nam. Children ≥5 years of age with a clinical diagnosis of DSS were enrolled into this study. Blood samples were taken daily during ICU stay and 7–10 days after hospital discharge for measurements of plasma levels of Syndecan-1, Hyaluronan, Suppression of tumourigenicity 2 (ST-2), Ferritin, N-terminal pro Brain Natriuretic Peptide (NT-proBNP), and Atrial Natriuretic Peptide (ANP). The primary outcome was recurrent shock. Ninety DSS patients were enrolled. Recurrent shock occurred in 16 patients. All biomarkers, except NT-proBNP, were elevated at presentation with shock. There were no differences between compensated and decompensated DSS patients. Glycocalyx markers were positively correlated with inflammatory biomarkers, haematocrit, percentage haemoconcentration, and negatively correlated with stroke volume index. While Syndecan-1, Hyaluronan, Ferritin, and ST-2 improved with time, ANP continued to be raised at follow-up. Enrolment Syndecan-1 levels were observed to be associated with developing recurrent shock although the association did not reach the statistical significance at the P < 0.01 (OR = 1.82, 95% CI 1.07–3.35, P = 0.038). Cardiovascular and inflammatory biomarkers are elevated in DSS, correlate with clinical vascular leakage parameters and follow different kinetics over time. Syndecan-1 may have potential utility in risk stratifying DSS patients in ICU

Rifampicin tolerance and growth fitness among isoniazid-resistant clinical Mycobacterium tuberculosis isolates: an in-vitro longitudinal study.

Antibiotic tolerance in Mycobacterium tuberculosis leads to less effective bacterial killing, poor treatment responses and resistant emergence. There is limited understanding of antibiotic tolerance in clinical isolates of M. tuberculosis . Therefore, we investigated the rifampicin tolerance of M. tuberculosis isolates, with or without pre-existing isoniazid-resistance. In-vitro rifampicin survival fractions determined by minimum duration of killing assay in isoniazid susceptible (n=119) and resistant (n=84) M. tuberculosis isolates. Rifampicin tolerance was correlated with bacterial growth, rifampicin minimum inhibitory concentrations (MICs) and isoniazid-resistant mutations. The longitudinal isoniazid-resistant isolates were analyzed for rifampicin tolerance based on collection time from patients and associated emergence of genetic variants. The median duration of rifampicin exposure reducing the M. tuberculosis surviving fraction by 90% (minimum duration of killing-MDK90) increased from 1.23 (95%CI 1.11; 1.37) and 1.31 (95%CI 1.14; 1.48) to 2.55 (95%CI 2.04; 2.97) and 1.98 (95%CI 1.69; 2.56) days, for IS and IR respectively, during 15 to 60 days of incubation respectively. Increase in MDK90 time indicated the presence of fast and slow growing tolerant sub-populations. A range of 6 log 10 -fold survival fraction enabled classification of tolerance as low, medium or high and revealed isoniazid-resistance association with increased tolerance with faster growth (OR=2.68 for low vs. medium, OR=4.42 for low vs. high, P -trend=0.0003). The high tolerance in longitudinal isoniazid-resistant isolates was specific to those collected during rifampicin treatment in patients and associated with bacterial genetic microvariants. Our study identifies a range of rifampicin tolerance and reveals that isoniazid resistance is associated with higher tolerance with growth fitness. Furthermore, rifampicin treatment may select isoniazid-resistant isolate microvariants with higher rifampicin tolerance, with survival potential similar to multi-drug resistant isolates. These findings suggest that isoniazid-resistant tuberculosis needs to be evaluated for rifampicin tolerance or needs further improvement in treatment regimen

A modified Sequential Organ Failure Assessment score for dengue: development, evaluation and proposal for use in clinical trials

Background Dengue is a neglected tropical disease, for which no therapeutic agents have shown clinical efficacy to date. Clinical trials have used strikingly variable clinical endpoints, which hampers reproducibility and comparability of findings. We investigated a delta modified Sequential Organ Failure Assessment (delta mSOFA) score as a uniform composite clinical endpoint for use in clinical trials investigating therapeutics for moderate and severe dengue. Methods We developed a modified SOFA score for dengue, measured and evaluated its performance at baseline and 48 h after enrolment in a prospective observational cohort of 124 adults admitted to a tertiary referral hospital in Vietnam with dengue shock. The modified SOFA score included pulse pressure in the cardiovascular component. Binary logistic regression, cox proportional hazard and linear regression models were used to estimate association between mSOFA, delta mSOFA and clinical outcomes. Results The analysis included 124 adults with dengue shock. 29 (23.4%) patients required ICU admission for organ support or due to persistent haemodynamic instability: 9/124 (7.3%) required mechanical ventilation, 8/124 (6.5%) required vasopressors, 6/124 (4.8%) required haemofiltration and 5/124 (4.0%) patients died. In univariate analyses, higher baseline and delta (48 h) mSOFA score for dengue were associated with admission to ICU, requirement for organ support and mortality, duration of ICU and hospital admission and IV fluid use. Conclusions The baseline and delta mSOFA scores for dengue performed well to discriminate patients with dengue shock by clinical outcomes, including duration of ICU and hospital admission, requirement for organ support and death. We plan to use delta mSOFA as the primary endpoint in an upcoming host-directed therapeutic trial and investigate the performance of this score in other phenotypes of severe dengue in adults and children

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Research Influence of Flux Air Gaps on Electromagetic Components of Shunt Reactors

This paper introduces an evaluation of the flux air gaps of Shunt Reactors (SRs) to effectively mitigate fringing and leakage fluxes along the height of the iron core. The assessment of these discretely distributed flux air gaps in SRs is a rigorous and challenging process. To define their exact number, the case of one flux air gap is analyzed and investigated to observe/simulate the influence of the flux density distribution and the leakage flux along the air gaps on the reactive power and the operation conditions of the SR. Based on that, to reduce leakage flux, a large flux air gap is divided into smaller ones. Initially, an analytic model is presented to define the main parameters of the SRs. Then, a finite element method is developed to simulate electromagnetic quantities, such as the magnetic flux density, leakage flux, and electromagnetic force. The obtained results can help manufacturers define the exact number of flux air gaps along the iron core of the SR. From that, a suitable technology can be given in manufacturing high voltage SRs applied to high or super high voltage transmission lines

Experimental Study on Impact of Thermal-Assisted Machining on SKD11 Steel Machinability

Machining in a heated environment has been used in pressure machining and metal cutting. Thermal-assisted machining is a new machining method performed on conventional machine tools, CNC machines, in which the workpiece is heated before machining. Different heat sources do the thermal-assisted: electrical energy, laser beam, magnetic induction. However, there is very little research on thermal-assisted machining when milling SKD11 steel, a difficult-in-processing material but widely used in the industry. Material machinability refers to the ability of material machining that is difficult or easy. Material machinability is measured by tool life, material removal ability, shear force, cutting vibration, surface roughness. The material's machinability is directly influenced by its microscopic structure and is related to the cutting mode. This paper has highlighted the study of material machinability when thermal-assisted machining and compared to the conventional one. This study also highlights the crucial role in assessing the effect of heating on the SKD11 steel machinability. This study analyzed the technological parameters' role on the shear force, chip shrinkage, surface roughness, and shear vibrations during normal machining and SKD11 steel heating. The study results showed that the material's microstructure and the amplitude of vibration did not change under the heating process's effect with a temperature range of 200oC - 400oC. However, the shearing force during heat processing is drastically reduced compared to conventional machining. Chip shrinkage increased by 31.7% when heated to 400oC, while roughness decreased by 47.1%

Ultrasound-Assisted Enzymatic Extraction of Adenosine from Vietnamese Cordyceps militaris and Bioactivity Analysis of the Extract

Vietnamese Cordyceps militaris (C. militaris) has long been recognized as one of the most valuable traditional Chinese medicines. In this study, adenosine was extracted from Vietnamese C. militaris by ultrasound-assisted enzymatic extraction method (UAEE) using water as a solvent. Then, the effects of five single factors on adenosine content including pH, enzyme-to-material ratio, ultrasonic power, ultrasonic time, and ultrasonic temperature were determined. After that, three factors consisting of ultrasonic power, ultrasonic time, and ultrasonic temperature were chosen based on their effects on adenosine content. The simultaneous influence of these factors on the adenosine content was investigated by response surface method using central composite design. The adenosine content was evaluated by high-performance liquid chromatography method. Under the optimal conditions, the extract was evaluated for antioxidant and anticancer bioactivities. In addition, different extraction methods including aqueous extraction (AE), ultrasound-assisted extraction (UAE), and enzyme-assisted extraction (EAE) methods were carried out to compare with UAEE. As a result, it can be concluded that UAEE is a promising method for adenosine extraction and further studies regarding isolation and purification need to be conducted

Emission reduction opportunities in a rapidly growing economy:\ua0a case study of Ho Chi Minh City

Vietnam’s Green Growth Action Plan for the period 2014–2020 sets out an overall plan for the sustainable development of the country. One of the cornerstones of that plan is the development of a greenhouse gas inventory and emission reduction opportunity assessment for Ho Chi Minh City. This provides a basis for the roadmap towards green growth in Ho Chi Minh City, one of Vietnam’s largest cities. Marginal costs of 38 emission reduction measures were determined for two main economy sectors, namely energy (32 measures) and agriculture, forestry, and other land use (6 measures). From that analysis, a marginal abatement cost curve was compiled for the energy sector. The total emission reduction opportunities available in 2020 are estimated to be 8.97 million tCO2e, which represents a 14.7% reduction compared to business as usual. Even when the city only implements reduction measures with negative marginal costs (i.e., abatement that saves money), significant reductions of 5.25 MtCO2e (8.6% reduction compared to business as usual) would be achieved. There are significant similarities in abatement opportunities between Ho Chi Minh City and Hanoi, Vietnam’s capital. The case study shows significant reduction in greenhouse gas emissions can be achieved in fast-growing cities with an appropriate level of investment and government support