Characterization of Structural Transition and Heterogeneity under Compression for Liquid Al2O3 Using Molecular Dynamics Simulation

We have performed a simulation of the structural transition and Structural Heterogeneity (SH) in liquid Al2O3 at 3500 K, in the range of 0–100 GPa. The results confirmed that the network structure of liquid alumina is built mainly from AlOx (x = 3, 4, 5, 6, 7) units, which are related to each other through the common oxygen atoms. The existence of separate AlO3-, AlO4-, AlO5-, AlO6- and AlO7- phases, where SH of the network structure can be sufficiently determined, besides, the existence of separate phases is clarified for SH in the liquid of Al2O3. In particular, at a pressure below 10 and beyond 20 GPa, AlOx units are uniformly distributed in the space and non-uniformly distributed in the range 10-20 GPa. Our study is expected to contribute to a simple way to determine the structural heterogeneity and diffusion coefficients of oxide systems. Doi: 10.28991/HIJ-2022-03-02-08 Full Text: PD

ENGLISH-MAJORED STUDENTS’ LISTENING DIFFICULTIES AND USE OF STRATEGIES AT MIEN DONG UNIVERSITY OF TECHNOLOGY, VIETNAM

Through the years, difficulties in English listening and listening strategies have been conducted by many researchers. Most of studies have pointed out the common difficulties and strategies which students often have. Focusing on the same subject with a new perspective, this research aimed at understanding English majors’ difficulties in listening and use of listening strategies. A total of ninety eight freshmen English-majored students at Mien Dong University took part in answering the questionnaire and five students answered the semi-structure interview questions. The data gained from the questionnaire were analyzed by SPSS version 20.0 in terms of descriptive statistic. The findings revealed that English-majored students had many difficulties in listening such as the difficulties related to the listener, the content of the dialogue, the speaker, the physical setting and the linguistic factors. In terms of listening strategies, the finding showed that the cognitive listening strategies were used more frequently than metacognitive and socio-affective strategies. Based on the findings, some implications were made to contribute to the administrations, teachers and students at Mien Dong University of Technology.  Article visualizations

AN INVESTIGATION INTO THE USE OF COLLOCATIONS IN ACADEMIC ESSAYS OF ENGLISH-MAJORED STUDENTS OF THE HIGH-QUALITY PROGRAM AT CAN THO UNIVERSITY, VIETNAM

One of the main goals of language learners is to master all four skills of listening, speaking, reading and writing when it comes to their acquisition of the target language. However, during the process of learning English, learners inevitably face a variety of challenges related to their writing including grammatical errors, word choice, organization, idea development, and most importantly their difficulties in using collocations (Duong & Nguyen, 2021). Therefore, this study has been conducted to investigate the students’ use of English collocations in their academic essays associated with their difficulties so that appropriate pedagogical approaches and practices would be taken into consideration in order to help students improve their English collocational competences in academic writing. This descriptive study was carried out with 103 English-majored students of the High-quality program of the School of Foreign Languages at Can Tho University, Vietnam. A 5-point Likert scale survey with 18 questionnaire items was employed to examine the frequency of students' exposure to as well as their usage of English collocations, and their difficulties in using English collocations. The results of this study have shown that the most commonly used collocations in the students’ academic essays were ‘verb + noun’, and ‘adjective + noun’ lexical collocations. Additionally, the research outcomes have revealed that the types of English collocations that the students were more likely to make the most mistakes belonged to ‘verb + adverb’, and ‘adjective + noun’ lexical collocations.  Article visualizations

Factors affecting to digital skills and adaptability of students in the context of digital transformation at the Ho Chi Minh city University of Technology and Education

The article focuses on analyzing the factors affecting students' digital skills and adaptability in the context of digital transformation. The study identified influencing factors: Environment, Behavior, Individuals, Teachers, Time of use, and access. However, the results of an online survey of 1.282 students of the Ho Chi Minh City University of Technology and Education (HCMUTE) with Cronbach's Alpha test method, EFA analysis, correlations, and regression analysis, showed that there are 3/5 factors identified in the hypothesis that affect digital skills and adaptability of HCMUTE students in the context of digital transformation, specifically: behavior (Beta = 0.177, Sig. = 0.000); individuals (Beta = 0.181, Sig. = 0.027); teacher (Beta = 0.547, Sig. = 0.000). Besides, the environment does not affect digital skills and adaptability (KNSKNTU) due to Beta = 0.017 and Sig.=0.384>0.05. Sig does not involve usage and access time factors. >0.05 in the table Correlations not be further analyzed in the regression model. The research results are expected to help provide a more objective view of the reality of digital adoption and student adaptability in the digital transformation context at HCMUTE

Factors affecting to digital skills and adaptability of students in the context of digital transformation at the Ho Chi Minh city University of Technology and Education

The article focuses on analyzing the factors affecting students' digital skills and adaptability in the context of digital transformation. The study identified influencing factors: Environment, Behavior, Individuals, Teachers, Time of use, and access. However, the results of an online survey of 1.282 students of the Ho Chi Minh City University of Technology and Education (HCMUTE) with Cronbach's Alpha test method, EFA analysis, correlations, and regression analysis, showed that there are 3/5 factors identified in the hypothesis that affect digital skills and adaptability of HCMUTE students in the context of digital transformation, specifically: behavior (Beta = 0.177, Sig. = 0.000); individuals (Beta = 0.181, Sig. = 0.027); teacher (Beta = 0.547, Sig. = 0.000). Besides, the environment does not affect digital skills and adaptability (KNSKNTU) due to Beta = 0.017 and Sig.=0.384>0.05. Sig does not involve usage and access time factors. >0.05 in the table Correlations not be further analyzed in the regression model. The research results are expected to help provide a more objective view of the reality of digital adoption and student adaptability in the digital transformation context at HCMUTE

EVALUATION OF GENETIC DIVERSITY OF THE BLACK GLUTINOUS RICE BASED ON AGRO-MORPHOLOGICAL CHARACTERS

The study assessed the variations in nine agro-morphological characters among and within the black glutinous rice (Oryza sativa) population from Chau Thanh District, Tra Vinh Province. The nine quantitative agromorphological characters that were measured include culm length, leaf length, leaf width, number of panicles, panicle length, grain length, grain width, number of firm grain, and number of grain per panicle. The unweighted pair group method with arithmetic mean method and principal coordinate analysis by the NTSYS program were applied in this study to classify the nine agro-morphological characters. In addition, to compare the variations in quantitative characters between O. sativa populations, one-way analysis of variance (ANOVA) was used. The results showed significant differences between the black glutinous rice populations for all quantitative agro-morphological characters. Moreover, some agro-morphological characters showed positive correlations to each other. The dendrogram generated from the analysis process of the agromorphological data divided the O. sativa populations into two groups with unfamiliar features. However, the O. sativa populations assessed exhibited a wide range of variations in morphological characteristics, both within the same population and among other populations with the same strains

HỢP CHẤT STEROID VÀ FLAVONE TỪ THÂN RỄ THIÊN NIÊN KIỆN LÁ LỚN (Homalomena pendula)

Phytochemical investigation of the rhizomes of Homalomena pendula resulted in the isolation of one flavone and three steroids. These compounds were determined as tangeretin (1), ergosterol peroxide (2), sitoindoside I (3), and stigmasterol (4) on the basis of 1D and 2D NMR data and in comparison with the available data in the literature. Compounds 1‒3 were found for the first time from the genus Homamomena. The n-hexane and ethyl acetate extracts show NO production inhibitory activity in RAW 264.7 macrophage cells with IC50 values of 46.8 and 75.52 µg·mL–1.Hợp chất flavone, tangeretin (1), và ba hợp chất steroid: ergosterol peroxide (2), sitoindoside I (3) và stigmasterol (4) đã được phân lập từ thân rễ của cây thiên niên kiện lá lớn (Homalomena pendula). Cấu trúc hóa học của chúng được xác định dựa trên phân tích dữ liệu phổ cộng hưởng từ hạt nhân (1D và 2D NMR) và so sánh với các tài liệu đã công bố. Các hợp chất (1-3) được phân lập lần đầu tiên từ chi Homalomena. Cao chiết n-hexane và ethyl acetate của cây này có hoạt tính ức chế sản sinh NO trên đại thực bào RAW 264.7 kích thích bằng lipopolysaccharide với các giá trị IC50 là 46,80 và 75,52 µg·mL–1

Multiple Wolbachia strains provide comparative levels of protection against dengue virus infection in Aedes aegypti.

The insect bacterium Wolbachia pipientis is being introgressed into Aedes aegypti populations as an intervention against the transmission of medically important arboviruses. Here we compare Ae. aegypti mosquitoes infected with wMelCS or wAlbB to the widely used wMel Wolbachia strain on an Australian nuclear genetic background for their susceptibility to infection by dengue virus (DENV) genotypes spanning all four serotypes. All Wolbachia-infected mosquitoes were more resistant to intrathoracic DENV challenge than their wildtype counterparts. Blocking of DENV replication was greatest by wMelCS. Conversely, wAlbB-infected mosquitoes were more susceptible to whole body infection than wMel and wMelCS. We extended these findings via mosquito oral feeding experiments, using viremic blood from 36 acute, hospitalised dengue cases in Vietnam, additionally including wMel and wildtype mosquitoes on a Vietnamese nuclear genetic background. As above, wAlbB was less effective at blocking DENV replication in the abdomen compared to wMel and wMelCS. The transmission potential of all Wolbachia-infected mosquito lines (measured by the presence/absence of infectious DENV in mosquito saliva) after 14 days, was significantly reduced compared to their wildtype counterparts, and lowest for wMelCS and wAlbB. These data support the use of wAlbB and wMelCS strains for introgression field trials and the biocontrol of DENV transmission. Furthermore, despite observing significant differences in transmission potential between wildtype mosquitoes from Australia and Vietnam, no difference was observed between wMel-infected mosquitoes from each background suggesting that Wolbachia may override any underlying variation in DENV transmission potential

The acceptability of and willingness to pay for a herpes zoster vaccine: A systematic review

Patients, predominantly the elderly, with Herpes Zoster (HZ) not only suffer symptoms of the disease but also bear considerable expenses. This study systematically reviewed the acceptability of and willingness to pay for the HZ vaccine. This review was registered in PROSPERO 2023 (CRD42023403062). We used “acceptance”, “willing to pay”, and “HZ vaccine” (and variations thereof) as keywords in a systematic search for original English research articles published up to April 7, 2023. The search was conducted over Scopus, PubMed, ScienceDirect, Cochrane, and Google Scholar in accordance with PRISMA 2020 guidelines. The inclusion criteria were as follows: studies (1) that mentioned HZ vaccination, (2) related to acceptability or willingness to pay, and (3) with full texts available and peer-reviewed prior to final publication. Grey literature, letters to editors, commentaries, case reports or series, systematic reviews, meta-analyses, articles of poor quality, and articles with ambiguously defined and measured outcome variables were excluded. The Joanna Briggs Institute (JBI) critical appraisal checklist was used to evaluate the methodological quality of the studies. Finally, the search yielded 24 studies, of which 9 were conducted in Asia, 8 in Europe, and 7 in America. General adults or patients aged 50 or older were often the target populations, for whom treatments were accompanied by healthcare providers’ recommendations. The willingness to pay and willingness to accept the vaccine ranged from $8 to$150 and 16.6% to 85.8%, respectively. Compared to the US, Asia and Europe had higher acceptance rates for HZ immunization. The most frequent excuses given for not being vaccinated are side effects, cost, lack of recommendations, anti-vaccination views, ignorance about the HZ vaccine, and the belief that one is not at risk for the disease. National campaigns should be developed to increase public awareness of HZ, and more international research should be conducted to understand the WTA and WTP for HZ immunizations

Transitions in diatom assemblages and pigments through dry and wet season conditions in the Red River, Hanoi (Vietnam)

Background and aims – Biomonitoring is an important tool for assessing river water quality, but is not routinely applied in tropical rivers. Marked hydrological changes can occur between wet and dry season conditions in the tropics. Thus, a prerequisite for ecological assessment is that the influence of ‘natural’ hydrological change on biota can be distinguished from variability driven by water quality parameters of interest. Here we aimed to (a) assess seasonal changes in water quality, diatoms and algal assemblages from river phytoplankton and artificial substrates through the dry-wet season transition (February–July 2018) in the Red River close to Hanoi and (b) evaluate the potential for microscopic counts and high-performance liquid chromatography (HPLC) analysis of chlorophyll and carotenoid pigments for biomonitoring in large tropical rivers.Methods – River water (phytoplankton) and biofilms grown on artificial glass substrates were sampled monthly through the dry (February–April) to wet (May–August) season transition and analysed via microscopic and HPLC techniques.Key results – All phototrophic communities shifted markedly between the dry and wet seasons. Phytoplankton concentrations were low (ca. thousands of cells/mL) and declined as the wet season progressed. The dominant phytoplankton taxa were centric diatoms (Aulacoseira granulata and Aulacoseira distans) and chlorophytes (Scenedesmus and Pediastrum spp.), with chlorophytes becoming more dominant in the wet season. Biofilm diatoms were dominated by Melosira varians, and areal densities declined in the wet season when fast-growing pioneer diatom taxa (e.g. Achnanthidium minutissimum, Planothidium lanceolatum) and non-degraded Chlorophyll a concentrations increased, suggesting active phytobenthos growth in response to scour damage. Otherwise, a-phorbins were very abundant in river seston and biofilms indicating in situ Chlorophyll a degradation which may be typical of tropical river environments. The very large range of total suspended solids (reaching > 120 mg L-1) and turbidity appears to be a key driver of photoautotrophs through control of light availability.Conclusions – Hydrological change and associated turbidity conditions exceed nutrient influences on photoautotrophs at inter-seasonal scales in this part of the Red River. Inter-seasonal differences might be a useful measure for biomonitoring to help track how changes in suspended solids, a major water quality issue in tropical rivers, interact with other variables of interest