A Framework for Task-Based Flipped Classroom in EFL Education in Vietnam

When it comes to language teaching in general education in Vietnam, there are many challenges for teachers to overcome. Such as time constraints, examination wash-back effects, students’ demotivation and students’ individualization causes of learning. Various innovative teaching methods and approaches have been applied to address these concerns, such as task-based language learning and flipped classrooms (FCs). However, each mode of teaching has its advantages and disadvantages. Due to this, it is essential to carefully examine the combination of TBLT and the flipped classroom (FC). This paper reviews the effects of the implementation of task-based language learning in the clipped classroom, discusses the integration of both teaching approaches, and suggests the applied model for English as a Foreign Language (EFL) education in Vietnam

Synthesis and Characterization of Ag/PEDOT:PSS Films Used for NH3_3 Selective Sensing

Nano-Ag/PEDOT-PSS films were prepared by spin-coating technique. SEM surface morphology, Raman spectra and gas sensing of methanol, humidity and NH3 were studied. The obtained results showed that the resistance of Ag/PEDOT:PSS sheets exposed to gases related to the generation of electrons from the gases adsorption that eliminated holes as the major carriers in PEDOT:PSS. For NH3 gas the largest change of the resistance of Ag/PEDOT:PSS was observed. The less sensitivity of humidity and ethanol sensing was explained due to less dedoping reaction between H2O and ethanol vapor with Ag/PEDOT:PSS, respectively. This suggests a potential application of the nano-Ag/PEDOT-PSS sensors for  the selective monitoring NH3 gas in environment

Short Tandem Repeats Used in Preimplantation Genetic Testing of Î’-Thalassemia: Genetic Polymorphisms For 15 Linked Loci in the Vietnamese Population

BACKGROUND: β-thalassemia is one of the most common monogenic diseases worldwide. Preimplantation genetic testing (PGT) of β-thalassemia is performed to avoid affected pregnancies has become increasingly popular worldwide. In which, the indirect analysis using short tandem repeat (STRs) linking with HBB gene to detect different β-globin (HBB) gene mutation is a simple, accurate, economical and also provides additional control of contamination and allele-drop-out ADO. AIM: This study established microsatellite markers for PGT of Vietnamese β-thalassemia patient. METHODS: Fifteen (15) STRs gathered from 5 populations were identified by in silico tools within 1 Mb flanking the HBB gene. The multiplex PCR reaction was optimized and performed on 106 DNA samples from at-risk families. RESULTS: After estimating, PIC values were ≥ 0.7 for all markers, with expected heterozygosity and observed heterozygosity values ranged from 0.81 to 0.92 and 0.53 to 0.86, respectively. One hundred percent of individuals had at least seven heterozygous markers and were found to be heterozygous for at least two markers on either side of the HBB gene. The STRs panel was successfully performed on one at-risk family. CONCLUSION: In general, a pentadecaplex marker (all < 1 Mb from the HBB gene) assay was constituted for β-thalassemia PGT on Vietnamese population

Screening for actinomyces isolated from soil with the ability to inhibit Xanthomonas oryzae pv. oryzae causing rice bacterial blight disease in Vietnam

Bacterial blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the major diseases in rice culture of Northen Vietnam, as well as other rice-growing regions of the world. In this study, we isolated and screened for actinomycete strains from Vietnam with the ability to inhibit Xoo isolates from northern Vietnam. From 90 actinomycete strains taken from soil in northern Vietnam in 2010, we screened for their antagonistic activity against 10 races of Xoo causing rice bacterial blight disease. Three actinomycete strains were found to inhibit all 10 Xoo races. Among the three strains, a strain namely VN10-A-44 was shown not to have the ability to produce toxic compounds and was selected for further study. The strain was identified as Streptomyces virginiae by 16S ribosomal RNA gene sequencing. We replaced soybean meal with tofu waste in antibiotic producing medium to improve antagonistic activity of VN10-A-44 against the Xoo pathogen and to make use of tofu waste for large-scale fermentation of VN10-A-44. We found that replacing soybean meal with 20 and 30 g of tofu waste/litter in the antibiotic producing medium gave the largest inhibition zone against the Xoo pathogen.Key words: Xanthomonas oryzae pv. oryzae, rice bacterial blight disease, Streptomyces virginiae, Vietnam

Farming systems in the sandy area of the Thua Thien Hue Province, Central Vietnam, survey of socio-economic situation and constraints identified by farmers

peer reviewe

A multi locus sequence analysis scheme for phylogeny of the Bacillus subtilis species complex and its advantages over 16S rRNA genes

A multi locus sequence analysis (MLSA approach) was studied on the Bacillus genus, or the Bacillus subtilis species complex for specific, including 08 strains from four species (B. subtilis, B. pumilus, B. licheniformis and B. amyloliquefaciens) were provided by Biotechnology Center of Ho Chi Minh City. The research was based on sequences of 16S rRNA genes, the concatenation of five protein-coding housekeeping genes: glpF, pta, purH, pycA, and rpoD. After PCR amplification and sequencing the phylogenetic tree of 16S rRNA sequences, concatenate sequences (as well as the phylogenetic tree of each housekeeping gene) are constructed for comparison and discussion. The aim of this study is reach for better resolution and differentiation of strains and species within the B. subtilis species and to determine whether MLSA scheme show advantages in 16S rRNA gene-based studies

Facile Synthesis of Carbon Quantum Dots by Plasma-liquid Interaction Method

Carbon quantum dots (CQDs) are a novel type of fluorescent nano-materials with various unique properties. They are recently attracting enormous interest due to their superiority in water solubility, chemical inertness, low toxicity, ease of functionalization as well as resistance to photo-bleaching and potential applications in biomedical indication, photo-catalysis, energy conversion, optoelectronics, and sensing. In this work, we present a facile and environmentally friendly synthesis of CQDs based on plasma - liquid interaction method. This is a single-step method and does not use toxic chemicals. The size distribution of obtained CQDs is rather uniform at approximately 3 nm. The emission peak of CQDs shifts from 427 nm to 523 nm as the excitation wavelength is varied from 340 nm to 460 nm. The non-equilibrium reactive chemistry of plasma liquid interaction is responsible for acceleration of the CQDs formation process

Investigation of Thermal Annealing Condition on the Optical and Electrical Properties of Hybrid Silver Nanowires/Reduced Graphene Oxide (AgNWS/rGO) Films

Herein we report a electrode in the hybrid  structure of the silver nanowires (AgNWs) with reduced graphene oxide (rGO) deposited on glass or PET substrate. The assembly and contacting in procedures of this hybrid film have been strongly affected by preparation conditions, especially annealing temperature. In this work, we have investigated the effects of thermal annealing on interconnected at nanowire junctions and between AgNWS network and rGO films via their sheet resistance and transmission. The annealing temperature was varied from 120$^{\circ}$C to 180$^{\circ}$C with 10$^{\circ}$C step to find out optimal temperature at which the wires can be joined together. The results show that at 170$^{\circ}$C, the sheet resistance and transmission of the hybrid rGO/Ag NW film are $R_{s} = 10.7\;\Omega$ sq$^{ - 1 }$ and $T = 77$% (at wavelength 550 nm) corresponding to the ratio of direct conductivity to optical conductivity $\sigma _{DC}/\sigma _{OP} = 126$ which is the best obtained value. It is expected that the hybrid AgNWS/rGO film can replace ITO film in the near future

Observation of whispering gallery modes in InGaN/GaN multi-quantum well microdisks with Ag plasmonic nanoparticles on Si pedestals

In this study, plasmonic freestanding InGaN/GaN multi-quantum well (MQW) microdisks were fabricated on Si (111) pedestals using wet chemical undercut etching, followed by decorating of Ag nanoparticles on microdisks to improve whispering gallery mode (WGM) resonance emission. The enhancement resulted from the plasmonic coupling effect between excitons in MQWs and localized surface plasmons of Ag. The radial resonance of WGMs from optically pumped microdisk cavities were observed in the photoluminescence spectra at a threshold optical pumping power density of 4.7 kW/cm2 with a WGM mode spacing of Δλ = 1.3 nm