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

Sex discrimination based on morphological traits in Mystus mysticetus Roberts, 1992

This study supplemented the way of sex determination of fish based on the regression relationship of some morphological indicators of Mystus mysticetus. A total of 425 fish specimens were collected by trawl nets at Cai Rang - Can Tho and Long Phu - Soc Trang from January to July 2022. After collection, the fish were transferred to the laboratory to determine their total length (TL), standard length (SL), eye diameter (ED), eye distance (DE), body height (BD), head length (HL), and mouth width (MD) before anatomy for sex determination based on gonads. The regression analysis results of TL-SL, TL-ED, TL-DE, TL-BD, TL-HL, and TL-MD showed that SL, DE, and MD could be used to determine the sex of this fish species because SL and DE were dominant in growth in males, and MD was prevalent in females. In addition, SL could be used to determine the sampling time and HL to determine the distribution environment

Phytoremediation of heavy metal polluted soil and water in Vietnam

Phytoremediation has been intensively studied during the past decade due to its cost-effectiveness and environmental harmonies. Most of the studies on treatment of heavy metal pollution in soil and water by plant species have been done in developed countries but are limited in Vietnam. In this study, we presented some research results of phytoremediation of polluted soils and water with heavy metals that were done by Institute of Environmental Technology for several last years. For treatment of heavy metal pollution in the water, some plants have great ability to accumulate heavy metals such as Vetiveria zizanioides, Phragmites australis, Eichhornia crassipes, Pistia stratiotes, Ipomoea aquatica, Nypa fruticans and Enhydra fluctuans. The heavy metal uptake into shoots and roots of 33 indigenous plant species in Thai Nguyen province was also determined. Two species of the plants investigated, Pteris vittata L. and Pityrogramma calomelanos L. were As hyperaccumulators, containing more than 0.1% As in their shoots while Eleusine indica, Cynodon dactylon, Cyperus rotundus and Equisetum ramosissimum accumulated very high Pb (0.15-0.65%) and Zn (0.22-1.56%) concentrations in their roots. Some experiments to clarify the potential of several plants as good candidates for phytoremediation of polluted soil by heavy metals were carried out in our institute.Phương pháp sử dụng thực vật để xử lý ô nhiễm đã được nghiên cứu nhiều trong thập kỷ qua do chi phí thấp và thân thiện với môi trường. Hầu hết các nghiên cứu về xử lý ô nhiễm kim loại nặng trong đất và nước bằng thực vật đã được thực hiện ở các nước phát triển nhưng ít có tại Việt Nam. Trong nghiên cứu này, chúng tôi giới thiệu một số kết quả dùng công nghệ thực vật để xử lý ô nhiễm kim loại nặng trong đất và nước tại Viện Công nghệ môi trường trong những năm gần đây. Dối với xử lý ô nhiễm kim loại nặng trong nước, một số thực vật có khả năng tích lũy tốt kim loại nặng như Vetiveria zizanioides, Phragmites australis, Eichhornia crassipes, Pistia stratiotes, Ipomoea aquatica, Nypa fruticans và Enhydra fluctuans. Sự hấp thụ và tích lũy kim loại nặng trong phần trên mặt đất và rễ của 33 loài thực vật bản địa tại Thái Nguyên cũng đã được xác định. Hai loài thực vật khảo sát là Pteris vittata và Pityrogramma calomelanos là những loài siêu tích lũy As, chứa hơn 0,1% As trong phần trên mặt đất của cây. leusine indica, Cynodon dactylon, Cyperus rotundus và Equisetum ramosissimum tích lũy Pb (0,15-0,65%) và Zn (0,22-1,56%) rất cao trong rễ. Một số thí nghiệm đánh giá tiềm năng của một số thực vật là đối tượng tốt cho xử lý ô nhiễm kim loại nặng trong đất đã được tiến hành trong phòng thí nghiệm của Viện Công nghệ môi trường

Factors Affecting Consumers’ Impulsive Purchasing Behavior in Circle K Convenience Stores in Hanoi, Vietnam

Impulsive purchasing behavior has been observed as one of the important studies conducted by marketers and researchers, as impulse buying has become a prevalent phenomenon in every retail format. The study was conducted to assess factors affecting consumers’ impulsive purchasing behavior in Circle K convenience stores in Hanoi, Vietnam. After reviewing a group of previous studies, the authors indicated 05 factors that affected consumers' impulsive purchasing behavior including impulsiveness, instant gratification, visual appeal, promotions and money availability. The study had selected 05 experts in the field of economics to conduct the expert interview. Moreover, the research team had also handed out the questionnaire and received 310 observations. Specifically, Impulsiveness had the strongest influence on the impulsive purchasing behavior of Circle K’s consumers in Hanoi. Keywords: factors, Impulsive purchasing behavior, Circle K convenience stores DOI: 10.7176/JESD/14-8-03 Publication date: April 30th 2023

Hemorrhagic Meningioma With Symptom of Convulsion: A Rare Presentation of Parietal Meningioma

Meningioma is the most common, extra-axial, non-glial intracranial tumor with an incidence of 2.3-5.5/100 000, accounting for 20%-30% of all primary brain tumor diagnoses in adults. Meningiomas associated with intratumoral hemorrhage are very rare occurring in 0.5%-2.4%. of individuals. Herein, we report a rare case of hemorrhagic meningioma with the symptom of convulsion. The case was a 68-year-old woman admitted to the hospital with severe headache and convulsions. Computed tomography revealed an increase in heterogeneous lesion measuring 4 × 3 × 2.5 cm at the right parietal lobe. Brain magnetic resonance imaging (MRI) showed a grossly stable homogeneously enhancing extra-axial mass measuring 43 × 33 × 28 mm, small calcified peripheral, intratumoral hemorrhage. Histopathology showed a multi-celled meningioma with bleeding areas (WHO grade I)

HMU fluorinze mouthwash enhances enamel remineralization: An in vitro study

BACKGROUND: Fluoride therapy has long been used extensively to prevent dental caries. Fluoride appears in variety of dental care products such as mouthrinse, dentifrice, gel, etc. HMU fluorinze is the first mouthwash containing fluoride in Vietnam. AIM: This research was conducted to evaluate the efficacy of HMU Fluorinze mouthwash on remineralizing enamel in laboratory conditions. METHODS: 20 third molars teeth were cleaned and covered with nail polish , except for a 3x3 mm square on their buccal surfaces. These teeth went through two steps: demineralization using Coke and remineralization for 20 days: 1) using standard calcifying solution (control group) and 2) using standard calcifying solution + HMU Fluorinze mouthwash 2 times/day (experimental group). The mineralization index of enamel structure after demineralization and remineralization was assessed by DIAGNOdent pen 2190. RESULTS: The mineralization indexes of the control group and experimental group at baseline were 3.65 ± 0.76 and 3.35 ± 0.64, after demineralization were in turn of 21.78 ± 4.48 and 20.25 ± 2.26; and after remineralization were 6.30 ± 1.03 and 3.90 ± 1.24. The different figures  between the two groups after remineralization shows statistical significance (p<0.01). Group B using HMU fluorinze mouthwash after 20 days did not differ from the original results (p = 0.272), in contrast with the control group (p<0.01). CONCLUSIONS: HMU fluorinze mouthwash has better mineralization effect than standard calcifying solution

A NOVEL DATASET FOR VIETNAMESE NEW YEAR FOOD CLASSIFICATION

Food classification has always piqued the interest of both domestic and international researchers, but numerous challenges remain. We present the dataset UIT-TASTET21, which contains over 77,000 color images of 18 traditional Vietnamese Lunar New Year dishes. We have experimented with classification using feature vectors from network architectures such as VGG16, Inception-v3, ResNet-50, Xception, and MobileNet-v2 to train support vector machines (SVMs), meeting the dataset’s challenges and laying the groundwork for the development of many optimal methods in the future that promise scientific breakthroughs in the service and commercial industries. At the same time, the authors desire to share a piece of Vietnamese cuisine’s distinctiveness with worldwide friends

COMPARISON EFFICACY OF ITS AND 18S rDNA PRIMERS FOR DETECTION OF FUNGAL DIVERSITY IN COMPOST MATERIAL BY PCR-DGGE TECHNIQUE

Through composting process, biosolid wastes are gradually transformed into compost material which can be used as soil fertilizer. Among microorganisms involved in composting process, fungi play important roles because they break down complex substrates, such as ligno-cellulose. Recently, PCR-DGGE technique has been considered as a useful tool for analysis of fungal diversity in environmental samples. Among other factors, primer set selection is necessary for successful of the PCR-DGGE analysis. There are several PCR primer sets targeting fungal variable regions of 18S ribosomal DNA (rDNA) and internal transcribed spacer (ITS) for the use in community analyses, however there exist just few reports on efficacy of these primers in studying fungal communities in compost materials. In this study, four different primer sets were tested, including EF4/Fung5 (followed by EF4/NS2-GC), EF4/ITS4 (followed by ITS1F-GC/ITS2), NS1/GC-Fung, and FF390/FR1-GC. Extracted DNA from compost materials often contains co-extracted humic substances and other PCR inhibitors. Therefore, the primers were tested for (i) tolerance to the PCR inhibitors presenting in the DNA extracted from compost materials, and (ii) efficacy and specificity of the PCR. The results showed that of the four primer sets, only FF390/FR1-GC achieved both criteria tested whereas the other three did not, i.e. primer EF4/ITS4 had low tolerance to PCR inhibitors, primers EF4/Fung5 was low in PCR amplification efficacy, whereas primers EF4/ITS4 created unspecific products. DGGE analyses of PCR products amplified with the primer set FF390/FR1-GC showed single bands for reference pure cultures Penicillium sp., Aspergillus sp., and Trichoderma sp., as well as distinctly separated bands for the fungal communities of three different composting materials. Thus, the primer set FF390/FR1-GC could be suitable for studying structure and dynamic of fungal communities in compost materials

Sex differentiation via the relationship between some morphological measurements of Mystus albolineatus caught from Cai Rang - Can Tho and Long Phu - Soc Trang

This study supplements the gender determination methodology based on the relationship of some morphological indicators in Mystus albolineatus. A total of 229 specimens were caught by trawl nets at Cai Rang – Can Tho and Long Phu – Soc Trang in four months from April to July 2023. After collection, the samples were transferred to the laboratory to determine the total length (TL), standard length (SL), eye diameter (ED), eye distance (DE), body height (BH), head length (HL), and mouth diameter (MD) before surgery to determine the sex based on the gonad. The results showed that the TL-SL regression relationship could be used to determine the sex of this fish. Besides, TL-BH and TL-MD growth relations were relatively balanced in females versus males. In addition, based on SL, DE, and MD, it was also possible to determine whether the sampling time was the wet or dry seasons. These findings form the basis for the initial study of the biological characteristics of this fish in the Mekong Delta

A Comparative Study of Optical Bistability in Three-Level EIT Configurations

We present a comparative study of optical bistability (OB) in three-level atomic configurations, including $\Lambda$-, cascade-, and V- types under the conditions of electromagnetically induced transparency (EIT). In the steady regime, the input-output intensity relations for the OB in each configuration have been derived in analytical form. The model allows one to construct a clear picture on how the threshold intensity, and other characteristics of the OB are continuously modified with respects to controllable parameters of the laser fields, cooperation parameter, and other physical parameters of atomic system. The results showed that the threshold intensity of OB in $\Lambda$-type system is much less than the other ones and the threshold intensity of OB in V-type system is the largest one. The analytical result is convenient to choose excitation configuration for experimental observations and related applications in photonic devices