Chemical composition and antimicrobial activity of the essential oil from leaves of Magnolia coriacea (Hung T. Chang & B. L. Chen) figlar growing in Vietnam

Leaf essential oil of Magnolia coriacea (Hung T. Chang B. L. Chen) Figlar growing wild in the Bat Dai Son Nature Reserve, Ha Giang Province, Viet Nam was obtained by hydrodistillation and its chemical composition was analyzed using GC/MS. In total, 45 compounds were detected in the essential oil, accounting for 87.1% of the oil, in which 37 compounds were identified accounting for 66.9%. Bicyclogermacrene (12.6%) and spathulenol (17.0%) were the main components of the leaf essential oil of M. coriacea. Antimicrobial activity of the essential oil sample was tested against three microorganism strains using an agar disk diffusion method. The results show that the inhibitory zone diameters ranged from 8.5 to 20.5 mm. Median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) of the essential oil was determined using microdilution broth susceptibility assay against seven test microorganism strains. Bacillus subtilis had the highest sensitivity with IC50 and MIC values of 185.9 and 512 µg/mL, respectively. 

Factors affecting intention to purchase organic agriculture products among Vietnamese

Globally, customer intention to purchase has become the essential part of the product and organization's success in the market. More recently, the idea has captured the attention of academic and policymakers alike. Therefore, the current article analyses product quality features such as agreeableness, emotional stability conscientiousness, openness to experience and extroversion on the intention to purchase organic agricultural products in the context of Vietnam. The study also analyses the mediating role of customer satisfaction between the association of product quality features and intention to purchase organic products in Vietnam. The present study uses questionnaires to collect data pertaining to the health sector of Vietnam. The current study employs the smart-PLS to analyze the constructs and items' reliability as well as the association among constructs. The results show that product quality features except extroversion have a positive and significant association with intention to purchase organic products in Vietnam. The results also reveal that customer satisfaction significantly and positively mediates among the associations of product quality features and intention to purchase organic products in Vietnam. This study is suitable for policymakers while formulating policies that may directly or indirectly affect customers' intention to purchase organic agricultural products.Luong Thu Thuy (Faculty of Economics, Academy of Finance, Vietnam), Tran Thi Phuong Diu (Faculty of Economics, Academy of Finance, Vietnam), Nguyen Dinh Hoan (Faculty of Economics, Academy of Finance, Vietnam), Vu Viet Ninh (Faculty of Economics, Academy of Finance, Vietnam), Nguyen Thi Thuy Nga (Faculty of Economics, Academy of Finance, Vietnam)Includes bibliographical reference

Payment Methods in Acquisitions of Association of Southeast Asian Nations Bidders

This paper examines the determinants of methods of payment in M&A transactions in ASEAN countries. We take into account the effects of characteristics of bidders, targets and countries on the choice of method of payment. The findings document the importance of bidders' technology status, targets' ownership status, relative size of bidders and targets, and especially the corporate governance variables in the countries that involved in those M&A transactions. In addition, crisis periods also distinguish the choices of payment method for domestic and cross-border M&As in ASEAN countries. Keywords: Methods of payment, ASEAN countries, Mergers, Acquisitions JEL Classifications: G32, G34, G3

Production of gamma-aminobutyric acid by lactic acid bacteria of marine origin from Vietnam

Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid, which functions as a neurotransmitter in the central nervous system. GABA has been shown to have several positive effects on human health, including reducing anxiety and promoting relaxation. In this study, various fermented fish products were screened for their ability to produce GABA. A total of 35 acid lactic producing strains were isolated from 8 samples of marine organism, 10 strains were found to have GABA-producing abilities. These strains were identified using 16S rDNA sequencing. The GABA concentrations produced by the 10 isolates ranged from 725 to 5590 mg/L. Lactobacillus brevis GB111 is the best isolated GABA producing strain, with a conversion rate up to 90.3%, which suggests that these strains may have potential applications in the food and pharmaceutical industries as a source of GABA

COMPARATIVE STUDY ON VOLATILE COMPOUNDS OF AGARWOOD FROM KHANH HOA PROVINCE EXTRACTED BY DIFFERENT METHODS

Agarwood from Aquilaria crassna cultivated in Khanh Hoa province was extracted by 5 methods, including simple, enzyme-assited, and microwave-assisted hydrodistillation, extraction with solvent and supercritical carbon dioxide. The volatile compounds of the products were analyzed by GC-MS. Almost all samples contain some common characteristic components, such as Valerianol, Agarospirol, Eudesmol b-, Eudesmol 10-epi-g-, 2-Allyl-4-methylphenol, Guaiol and Neopetasone. However, there were obvious differences in yields, composition, and number of identified components. The application of the more advanced methods for the extraction of agarwood resulted in saving of time and energy, and some improvement of product yield. However, these methods also lead to unconventional products with many unknown components, what requires further investigations

Morphodynamic modeling and causes of closure of My A inlet

Morphodynamics and sediment transport of the My A inlet in the low flow season are modeled using Delft3D. The simulation model takes into account the forcing of waves, tides and river flows. Model outputs of sediment transport and morphological changes of allow analysing the mechanism and cause of inlet closure. The analysis shows that longshore sediment is accreted on the northern side of the inlet both on the ebb tidal delta and along the north coast, but onshore sediment transport by wave reworking is the main process to close the inlet

Estimating Water Content and Grain Size of Intertidal Flat Sediments Using Visible to Shortwave-Infrared Reflectance and Sentinel 2A Data: A Case Study of the Red River Delta, Vietnam

Sediment properties such as water content (WC) and grain size (GS) are essential to characterize the environmental conditions of tidal flats. This article aimed to develop appropriate models to estimate the WC and GS of surface sediments for an intertidal flat on the Red river delta (Vietnam) using Sentinel 2A (S2A) images. The spectral reflectance, WC, and GS of 96 sub-samples from 12 sediment samples collected on December 17, 2017 were measured to clarify their relationships. The WC was highly correlated with the reflectance ratio of two shortwave-infrared bands, R(2190)/R(1610) (R² = 0.93). The median GS (D₅₀) at 0%, 15%, and 20% of WC was significantly correlated with the reflectance ratio of the near-infrared band (842 nm) versus the visible-green band (560 nm) (R² > 0.78). Next, D₅₀ was estimated from a multivariate regression model using this band ratio, the visible-red band (665 nm), and WC. The accuracy of the models was verified by comparisons with WC and D₅₀ from 20 samples collected on March 12th 2019 (RMSE of both WC and D₅₀ 30%) in very fine sediments (silts), which is consistent with other intertidal flats with similar sediment types. This article was limited to fine sediment samples. Therefore, our next step is to incorporate coarse sediments into the models to provide more universal mapping of WC and sediment types

Reimagining the language of disability and inclusion in primary teacher education through a translanguaging framework

© 2023 The Authors. Published by Taylor & Francis. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1080/25783858.2023.2215936Whilst words such as ‘disability’ and ‘inclusion’ have some shared meanings across cultural and linguistic contexts, they also have meanings that are fluid and changing according to individual, institutional, and environmental dimensions. Deconstructing these differential understandings in special education needs and disabilities (SEND) provision is essential to challenge deeply-rooted societal deficit-based assumptions and stigmatisation that can have detrimental impacts on children and young people’s life experiences. In this UK-Vietnam collaborative project we aimed to uncover the ‘languaging of disability and inclusion’, using Vietnamese primary teacher education as an illustrative case study with experiential insights gathered from primary school teachers, leaders and teacher educators. This paper presents findings from our six in-depth qualitative interviews. Our analytical framework, informed by key concepts in translanguaging and affective pedagogies, enables us to uncover nuances in meanings that went beyond solely Vietnamese-English linguistic translations, to take account of semiotic understandings, body language, and movement. Key findings revealed a prevailing medical-based terminology associated with SEND, practice-based contradictions attached to bureaucratic recognitions of disability, as well as repertoires associated with ‘circles of friendship’. Our paper opens up an international dialogue that both challenges potentially homogenising and harmful labelling processes and celebrates the sharing of asset-based languaging practices

An Analytical Framework Considering the Effects of Online Teaching Quality on Student Satisfaction

COVID-19 spreads across the world in late 2019 has affected to several aspects of social life. One of the most important sectors, which face difficulties was education, thus most universities have transferred from traditional education to online education through the internet to make their academic year going. This study aims to review the effects of online teaching quality on student satisfaction, a positive attitude resulting from an evaluation of students’ online teaching experience in higher education. Through applying the SERVQUAL model to measure the effects of online teaching quality on students’ satisfaction, it can be expected to get better the online teaching quality of higher education institutions in Vietnam. Keywords: Online teaching, student satisfaction, higher education, COVID-19, educational institution. DOI: 10.7176/EJBM/13-6-08 Publication date:March 31st 202

Nanoparticles as a control for cyanobacterial bloom

This study aims to investigate the toxicity of copper material synthesized by chemical reduction method and effects of environmental variables on growth of phytoplankton community (dominated by Microcystis genus) in the Tien eutrophic lake, Hanoi, Vietnam. The variables analyzed include: physical (pH and Turbidity), chemical (content of NH4+, PO43- and copper metal), biological (content of Chlorophyll-a, cell density). The characteristic of nanomaterial was confirmed by using UVvisible spectrophotometer, XRD, SEM and TEM methods. The CuNPs showed they spherical form and uniform size about 20-40 nm. The experimental results showed that the treated with CuNPs inhibition on growth against phytoplankton after 8 days. The cell density of phytoplankton community and Microcystis genus in samples exposure with CuNPs declined after 8 days from 647.037 and 467.037 down to 381.111 and 202.592, respectively.Mục đích của nghiên cứu này là khảo sát độc tính của vật liệu nano đồng được tổng hợp bằng phương pháp khử hóa học và ảnh hưởng của các yếu tố môi trường đến sinh trưởng và phát triển của quần xã thực vật nổi (chủ yếu là chi Microcystis) trong nước hồ Tiền phú dưỡng, tại Hà Nội, Việt Nam. Các thông số phân tích bao gồm: thủy lý (pH và độ đục), hóa học (hàm lượng amoni, photphat và hàm lượng đồng kim loại), sinh học (hàm lượng chất diệp lục, mật độ tế bào). Đặc trưng của vật liệu được xác định bằng các phương pháp quang phổ UV-VIS, XRD, SEM và TEM. Vật liệu nano đồng có dạng hình cầu, kích thước đồng nhất từ 20 đến 40 nm. Kết quả thử nghiệm sau 8 ngày cho thấy các mẫu có bổ sung vật liệu nano đồng ức chế sinh trưởng quần xã thực vật nổi ở nồng độ 1mg/l. Mật độ quần xã thực vật nổi và chi Microcystis trong mẫu xử lý với CuNPs đã giảm tương ứng sau 8 ngày từ 647.037 và 467.037 xuống còn 381.111 và 202.592