USING ROLE PLAY TO MOTIVATE HIGH-SCHOOL STUDENTS IN EFL SPEAKING CLASSES

The recurrent problem among Vietnamese high school students in learning English is the ability to communicate effectively in the target language. The question of how to motivate students to speak English confidently and effectively has driven the researcher to search and experiment with various pedagogical techniques. Therefore, this study is conducted to investigate to what extent using role play can increase students’ motivation in EFL speaking classes. The role play technique has been implemented with a group of 33 Math-majored students at a specialised high school in Vietnam. Data collected from observation notes and interviews with 6 student participants revealed that students’ motivation to speak English was high. The results also indicate that role play can be fruitfully deployed in EFL-speaking classes to increase students’ engagement in language production.  Article visualizations

EMI in Vietnam: What High School Teachers Think and Do

The current case study was driven by a recent policy on using English as a medium of instruction (EMI) in the mainstream school system in Vietnam. It aimed to explore what science teachers believed and reported doing about EMI in teaching science subjects in the high school context. Nine EMI teachers of different science subjects at a specialized high school in the Mekong Delta of Vietnam participated in a semi-structured interview. Thematic analysis revealed the perceived positive impacts on teachers’ and students’ English proficiency, and negative influences on science content coverage. In practice, the teachers reported a focus on simple contents, explaining specialized terminologies and key concepts as the input. They mainly employed a lecture style and teacher initiation-student response interaction, switching between English and Vietnamese during their lessons. These results imply that EMI across the curriculum has the potential to improve English proficiency of students, but the EMI policy needs to consider its transparency in goals and communication to stakeholders especially teachers and school managers.  &nbsp

Transcriptome profiling of infected chickens with newly emerged genotype VI I Newcastle disease virus strains

Since it was reported in Indonesia in 1926, Newcastle disease (ND) is an endemic disease in Indonesia resulting in devastating economic losses in poultry. Despite heavy vaccination programs, NDV infection still occurs among commercial chicken farms, including vaccinated birds in Southeast Asia, especially in Indonesia. Therefore, the first objective was to detect and perform full genome sequencing of highly virulent circulating NDVs in vaccinated chicken flocks to identify the most adequate NDV strains as vaccine candidates. Our full genome sequencing analysis on two selected isolates from vaccinated birds in Indonesia has shown that both of them belong to highly virulent NDV-GVII.2 strains, while only 0.4% of the vaccine strains used in this country are genotype VII. Moreover, sequencing analysis of the existing genotype VII vaccine revealed that it has significant differences from GI vaccine strain, which is not sufficiently representative of genotype VII viruses. This finding illustrates that virulent NDV-GVII.2 strains are mainly responsible for the high morbidity and mortality of recent ND outbreaks in poultry in Indonesia. Virulent NDV-GVII strains were previously characterised as immunopathological phenotypes triggering severe tissue damage probably through apoptosis and necrosis of lymphoid tissues. However, the underlying molecular mechanism of pathogenesis of ND remains to be fully understood. Hence, the second objective was to identify and characterise the molecular mechanism of lymphotropic behaviour of NDV-GVII by focusing on detecting key biomarkers and cellular immune response signalling pathways that contribute to severe lymphocyte destruction in infected birds using RNA sequencing, bioinformatics tools and PPI network analysis. Transcriptomic profiling indicates that virulent NDV-GVII significantly downregulates immunologically regulated genes and innate immune regulating pathways including fMLP signalling in neutrophils, Fcy receptor-mediated phagocytosis in macrophages and monocytes, and leukocyte extravasation signalling and NF-kB activation by viruses. These transcriptional changes may lead to widespread immunosuppression and enhanced replication of the virus. As a result, the host’s immune response may be diminished, delayed, incomplete or display overly strong induction that can cause severe tissue damage. This finding also implies that virulent NDV-GVII strains appear to possess the capability to inhibit the induction of immune responses by targeting lymphocytes and destroying these cells, which may be one indispensable factor of the pathogenesis of NDV-GVII. Moreover, PPI network analysis revealed that the top three significantly enriched gene modules were phagocytosis, immune response-related terms, and glutamate receptor signalling pathway. We identified novel genes EGF, LPAR5, AGT, AGTR1, RAC2, CD4, CD3D, IL7R, NPY, GRM3, and GRAP2 as potential biomarkers. This study provides valuable information to help understand novel immune evading mechanisms of highly pathogenic NDV-GVII from a host-pathogen interaction point of view. Interactions between the virus and the host determine the success of the viral infection. Hence, the third objective was to identify any particular genes of the virus that may have an important role in virulence and pathogenicity by profiling the transcription of virus in infected birds. This study revealed the transcriptional gradient of these highly pathogenic NDV-GVII genes: NP:P:M:F:HN:L, in which there were a slight attenuations at the NP:P and HN:L gene boundaries. Our result also provides a fully comprehensive qRT-PCR protocol for measuring viral transcript abundance that may be more convenient for laboratories where accessing HTS is not feasible.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 202

Post-mortem Reproduction from a Vietnamese Perspective—an Analysis and Commentary

Post-mortem reproduction is a complex and contested matter attracting attention from a diverse group of scholars and resulting in various responses from a range of countries. Vietnam has been reluctant to deal directly with this matter and has, accordingly, permitted post-mortem reproduction implicitly. First, by analysing Vietnam’s post-mortem reproduction cases, this paper reflects on the manner in which Vietnamese authorities have handled each case in the context of the contemporary legal framework, and it reveals the moral questions arising therefrom. The article then offers an account of Vietnamese social norms as an explanation for the tendency to conduct post-mortem reproduction. In arguing that a deeper and more thorough examination of the moral and ethical reasoning is required, the paper advocates in favour of supportive post-mortem reproduction regulation. In doing so, the paper seeks to reconcile the Vietnamese legal framework and post-mortem reproduction experiences of other countries. The article concludes that Vietnam and countries sharing the similar cultural traits should permit post-mortem reproduction explicitly. This would require full engagement with the ethical and legal issues arising, and careful promulgation of regulations and guidelines based on comparative experiences of a range of countries in handling this matter

The effectiveness of MgCeAl11O19:Tb3+ phosphor in enhancing the luminous efficacy and color quality of multi-chip white LEDs

In this research paper, we introduced yellow-green MgCeAl11O19:Tb3+ asa new phosphor ingredient to adapt to the quality requirements onthe chromatic homogeneity and emitted luminous flux of modern multi-chip white LED lights (MCW-LEDs). The results from experiments and simulation show that employing MgCeAl11O19:Tb3+ phosphor can lead to much better optical properties and therefore is a perfect supporting material to achieve the goals of the research. When the MgCeAl11O19:Tb3+ phosphor is added into the phosphorus composite which already contains YAG: Ce3+ particles, and the silicone glue, it affects the optical properties significantly. In other words, the concentration of this phosphor can determine the efficiency of lumen output and chromatic homogeneity of WLEDs. In specific, as the concentration of MgCeAl11O19:Tb3+ go up, the luminous yield will increase accordingly, though there is an insignificant decrease in CQS. Moreover, if the MgCeAl11O19:Tb3+ concentration reduce a little bit, it is possible to better the correlated color temperature uniformity and lumen efficacy of LED packages. In addition, the Mie scattering theory, Monte Carlo simulation and LightTools 8.3.2 software are employed to analyze and simulate the LED packages’ structure as well as the phosphor compound

Na3Ce(PO4)2:Tb3+ and Na(Mg2–xMnX)LiSi4O10F2:Mn phosphors: a suitable selection for enhancing color quality and luminous flux of remote white light-emitting diodes

This study proposed the TRP, a remote phosphor structure that has 3 phosphor layers, to ehance the chromatic quality and lumen output for white light-emitting diodes devices (WLEDs). The arrangment of phosphor layers is yellow YAG:Ce3+ phosphor, green Na3Ce(PO4)2:Tb3+ phosphor, and red Na(Mg2–xMnX)LiSi4O10F2:Mn phosphor from bottom to top. Red Na(Mg2–xMnX)LiSi4O10F2:Mn phosphor is used for the red light component to boost color rendering index (CRI). The green layer Na3Ce(PO4)2:Tb3+ phosphor is utilized for the green light component to produce higher luminous flux (LF). With the addition of red and green phosphor, the yellow YAG:Ce3+ concentration must decrease to maintain the 6000 K color temperature. The research results show that red phosphor Na(Mg2–xMnX)LiSi4O10F2:Mn concentration is beneficial for CRI, while green phosphor Na3Ce(PO4)2:Tb3+ is detrimental to CRI. Morever, CQS reaction with red and green phosphor is also studied, which show notable improvement when Na(Mg2–xMnX)LiSi4O10F2:Mn concentration is from 10%-14%, regardless of Na3Ce(PO4)2:Tb3+. The luminous flux (LF) can also increase for more than 40% with the reduced light loss and added green phosphor. Research results are valuable references for producers to enhance the color quality and the light emission of WLEDs

The application of double-layer remote phosphor structures in increasing WLEDs color rendering index and lumen output

The remote phosphor structure often has inferior color quality but better luminous flux in than conformal or in-cup configurations. Therefore, numerous researches study remote phosphor structure for methods to enhance it chromatic quality. This study introduces the use of dual-layer remote phosphor structure in WLEDs with identical structure but at different color temperature, 6600K and 7700K, to demonstrate their effect on quality indicators. The concept is placing a green phosphor layer (Ce,Tb)MgAl11O19:Ce:Tb or a red phosphor layer MgSr3Si2O8:Eu2+,Mn2+ on the layer of yellow-emitting phosphor YAG:Ce3+ and find the suitable concentration of the additional phosphor to create the best color quality. The results showed that the increase of CRI and CQS are affected by MgSr3Si2O8:Eu2+,Mn2+, in particular, the higher the concentration of red phosphor gets the better CRI and CQS because the emitted red light in enhanced. The green phosphor layer (Ce,Tb)MgAl11O19:Ce:Tb, on the other hand, is beneficial for the luminous flux. The concentration of MgSr3Si2O8:Eu2+,Mn2+ and (Ce,Tb)MgAl11O19:Ce:Tb, however, need to be adjusted properly to avoid decreasing the luminous flux due to overgrowth. The Mie scattering theory and Beer’s law are the verification tools for these conclusions, which gives them the credibility to be applied in producing better quality WLEDs

LaSiO3Cl:Ce3+,Tb3+ and Mg2TiO4:Mn4+: quantum dot phosphors for improving the optical properties of WLEDs

In this research, we focus on the solutions to enhance the lighting properties as well as the heat regulation of the white light-emitting diodes (WLEDs) with conventional phosphor and quantum dots (QDs). Although receiving lots of attention for being an innovative lighting solution with good color rendering index, the potentials of WLEDs conjugated with quantum dots (QDS), especially the QDs-phosphor mixed nanocomposites ones, are restrained due to the lacking performance in the aspects mentioned above. The crucial requirement to produce better WLEDs is finding solutions that improve the lacking aspects, therefore, through observing previous studies and applying advanced technique, this research suggest an effective and unique packaging configuration, in which the nanocomposites QDs-phosphor layer is set horizontally to the WLED. This novel packaging configuration allow WLED performance in terms of lighting and heating to reach it peaks. This is the first time four different types of WLEDs, single-layer phosphor, dual-layer remote phosphor with yellow-red and yellow-green, and triple-layer phosphor, were simulated, utilized and compared in one study to decide the best WLED configuration. The results show that the triple-layer phosphor configurations improve the color rendering ability and lumen output better than the other configurations

SrBaSiO4:Eu2+ phosphor: a novel application for improving the luminous flux and color quality of multi-chip white LED lamps

This paper described in detail the chromatic homogeneity and luminous flux influences in producing better quality white LED devices with various phosphor layers (MCW-LEDs). The method is to let Eu2+-activated strontium–barium silicate (SrBaSiO4:Eu2+) mixed with their phosphor compounding, which results in notable impact on lighting performance. The increase in concentration of yellow-green-emitting SrBaSiO4:Eu2+ phosphor also promotes the color performance and lumen output of WLED devices at high correlated color temperature around 8500K. This is the first time this approach is applied and it results can be utilized for better understanding of optical properties interaction with phosphor materials. Although SrBaSiO4:Eu2+ receives many positive responses, we still need to limit it concentration for high SrBaSiO4:Eu2+ concentration is detrimental to CQS. The appropriate choice of concentration and size of SrBaSiO4:Eu2+ is the principal factor to decide the performance of MCW-LEDs

Y2O3:Ho3+ and ZnO:Bi3+: a selection for enhancing color quality and luminous flux of WLEDs

As the luminescence industry develops, the white light light-emitting diode (LED) package with a single chip and a single phosphor although produces good luminous flux but has a poor color rendering index (CRI) can no longer fulfill the requirements of modern lighting applications. Therefore, this research is conducted to response to the urgent demands of improving other lighting qualities of WLED while maintaining high luminous efficiency. To achieve this target, we applied the new WLED package, which contains multi-chips and multi-phosphor layers, and have obtained outstanding results in both CRI and luminous efficacy. Two types of phosphor used in the WLED package are Y2O3:Ho3+ and ZnO:Bi3+. A color configuration model is also developed to adjust the shading of the white-light LED module. The results of this research show that the triple-layer phosphorhas the best performance when applied in a white-light LED package, which is demonstrated through better color quality, CRI and luminous efficacy, The manufacturers can rely on this research to produce the optimal-quality WLED, or WLED that is appropriate to their quality demands