Learning achievement and knowledge transfer: the impact factor of e-learning system at Bach Khoa University, Vietnam

E-learning is the application of innovative ICT platforms and Internet in education to make it easier, spacious, and more efficient. Advantages of e-learning are recognized, but its impact on learning achievement and knowledge transferring are not confirmed clearly. Learning is considered the skills of students and knowledge gained through experience in the training process. Learning achievement has been defined as students' knowledge, skills and study habits in a training course and effectiveness of their application to their work. Based on previous research, this study suggested that learning achievement as a dependent variable affected by the capacity factors, such as: computer self efficacy, ease of use, perceived usefulness, face to face interaction, e-mail interaction, and social presence. Besides, knowledge transfer is also affected by learning achievement. The study result showed that 3 factors: easiness & usefulness, e-mail interaction, and social presence have positive impacts on learning & transferring knowledge through the e-learning system of Bach Khoa University (BKU). Based on analysis results, some managerial implications are suggested for improving the effectiveness of e-learning system at BKU

A conceptual framework of virtual team effectiveness from the socio-technical perspective

In the era of globalization and technologization, virtual teamwork has become a routine part of professional activity in the software industry and other industries. Understanding virtual team effectiveness helps the management to improve the overall effectiveness of organizations. In this paper, we conduct a literature review of team research to set up a conceptual framework of virtual team effectiveness based on the socio-technical perspective and Inputs-Mediators- Outputs-Inputs model. Our framework includes some salient inputs, mediators and outputs of virtual team life-cycle; specifically, technology readiness and intention to explore are two technical antecedents; team learning and transactive memory system are two social antecedents; and team performance is a socio-technical output representing virtual team effectiveness. After that, a 27-item measuring instrument of aforesaid concepts is proposed after a qualitative survey of 19 virtual team leaders and a quantitative survey of 151 virtual team members from 19 companies locating in Vietnam. The results are references for those interested in improving virtual team effectiveness

Knowledge sharing in virtual teams: A research in information technology companies in Vietnam

Nowadays, virtual teams bring both benefits and drawbacks to companies, especially to information technology companies. Improving virtual team performance is a requisite to speed up the development of information technology companies. This article conducts quantitative research on virtual team members in Vietnam’s information technology companies to investigate the relationships between social capital, risk of opportunistic behaviors, knowledge sharing, and team performance in the situation of virtual teams. The study uses SPSS and AMOS to analyze data collected from 268 valid samples. We find out a reliable 15-variable scale which can be used to measure structural social capital, cognitive social capital, rational social capital, risk of opportunistic behaviors, knowledge sharing and virtual team performance. The results show the positive effects of structural social capital and cognitive social capital on knowledge sharing and virtual team performance. The findings also reveal the negative effects of risk of opportunistic behaviors on knowledge sharing and virtual team performance and a positive correlation between knowledge sharing and virtual team performance. This article can be used as a reference for managers to build solutions for improving virtual team performance in information technology companies in Vietnam

Impacts of κ- oligocarrageenan application on photosynthesis, nutrient uptake and bean yield of coffee (Coffea robusta)

κ-Oligocarrgeenan (OC) is well known as an effective and green plant growth promoter and elicitor. However, its effect on coffee plant has not been investigated so far. This study aimed to examine the impacts of OC on biophysical activity, vegetative growth and productivity of coffee plant (Coffea robusta). OC with average molecular weight (AMW) of 4.0 kDa was prepared by depolymerization of carrageenan using ascorbic acid. Field experiments were conducted by foliar spray four times per year at various OC concentrations (50, 100, 150, 200, and 250 ppm) for three years (2017-2019). The results showed that OC promoted growth of coffee plant in all tested concentrations, and an optimized concentration was found at 150 ppm which showed a significant increase compared to the control plant in total chlorophyll (24.79%), carotenoid (31.65%), uptakes of N (15.66%), P (15.81%), and K (22.25%) minerals in leaves, crop yield (19.80%) and bean size (13.10%). Therefore, OC is potentially promising to apply as a promoter to enhance yield of crops for sustainable coffee plantation

THÀNH PHẦN HÓA HỌC VÀ HOẠT TÍNH KHÁNG VI SINH VẬT GÂY BỆNH CỦA TINH DẦU TỪ VỎ BƯỞI DA XANH (Citrus maxima (Burm.) Merr.)

Pomelo is a Vietnam’s plant species with high nutritional and economic value. Besides, pomelo essential oil contains numerous compounds with high biological activity. The essential oil is extracted by using steam distillation, and its chemical composition is determined by means of GC-MS. The major components are limonene (91.19%), b-myrcene (2.92%), a-phellandrene (1.98%), and a-pinene (1.19%). The antimicrobial activity of essential oils is tested against pathogenic Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and Aspergillus flavus at different concentrations with the agar well diffusion method. This essential oil is active against B. cereus, S. aureus, and E. coli with inhibition diameter zones at 8.3–11.3, 10.3–18.7, and 9.0–11.7 mm, respectively, and inhibits A. flavus mold with 18.9–65.0% efficiency.Bưởi là loài cây không chỉ có giá trị cao về mặt dinh dưỡng mà còn có giá trị cao về mặt kinh tế và được trồng phổ biến ở Việt Nam. Ngoài ra, tinh dầu bưởi chứa nhiều hợp chất có hoạt tính sinh học cao. Tinh dầu bưởi được chiết xuất bằng phương pháp chưng cất lôi cuốn hơi nước và thành phần hóa học được phân tích bằng phương pháp GC-MS. Thành phần chính của tinh dầu gồm limonene (91,19%), b-myrcene (2,92%), a-phellandrene (1,98%) và a-pinene (1,19%). Hoạt tính kháng vi sinh vật của tinh dầu được khảo sát với vi khuẩn Gram dương (Bacillus cereus, Staphylococcus aureus), Gram âm (Escherichia coli) và nấm mốc Aspergillus flavus ở nồng độ 5, 10, 25 và 50% bằng phương pháp khuếch tán giếng thạch. Tinh dầu có khả năng kháng B. cereus, S. aureus và E. coli với đường kính vòng kháng khuẩn lần lượt là 8,3–11,3, 10,3–18,7 và 9,0–11,7 mm và ức chế sự phát triển của A. flavus (18,9–65,0%)

Cider Production from King Mandarin (Citrus nobilis Lour.) and Its Antioxidant Activity

With the necessity of diversifying alcoholic beverages, cider has become a kind of drink that can fulfill this demand. This is because the cider will be diversified depending on the kinds of fruit that are chosen to be used for the cider fermentation. Therefore, this study aims to investigate the effects of dilution ratio, Brix, pH, and yeast concentration on the production of cider from king mandarin (Citrus nobilis Lour.), and to evaluate the analytical characteristics and antioxidant activity of the product. After the investigation, it can be claimed that the dilution of the juice causes the ethanol content to decrease, whereas the increase of Brix, pH, and yeast concentration makes the ethanol content increase. However, the proportional increase in the ethanol content with Brix, pH, and yeast concentration has its limitations. Specifically, when the Brix and the yeast concentrations were, respectively, higher than 16°Brix and 0.04%, the ethanol content tended to maintain the same. This is also the same when the pH was lower than 4.5. In addition, by using the DPPH and ABTS●+ methods, the antioxidant activity of cider is estimated to be lower than the one of the juice before fermentation, which is smaller than 3.78 times for the DPPH method and 3.76 times for the ABTS●+ method

TextANIMAR: Text-based 3D Animal Fine-Grained Retrieval

3D object retrieval is an important yet challenging task, which has drawn more and more attention in recent years. While existing approaches have made strides in addressing this issue, they are often limited to restricted settings such as image and sketch queries, which are often unfriendly interactions for common users. In order to overcome these limitations, this paper presents a novel SHREC challenge track focusing on text-based fine-grained retrieval of 3D animal models. Unlike previous SHREC challenge tracks, the proposed task is considerably more challenging, requiring participants to develop innovative approaches to tackle the problem of text-based retrieval. Despite the increased difficulty, we believe that this task has the potential to drive useful applications in practice and facilitate more intuitive interactions with 3D objects. Five groups participated in our competition, submitting a total of 114 runs. While the results obtained in our competition are satisfactory, we note that the challenges presented by this task are far from being fully solved. As such, we provide insights into potential areas for future research and improvements. We believe that we can help push the boundaries of 3D object retrieval and facilitate more user-friendly interactions via vision-language technologies.Comment: arXiv admin note: text overlap with arXiv:2304.0573

Genome evolution of dengue virus serotype 1 under selection by <i>Wolbachia pipientis</i> in <i>Aedes aegypti</i> mosquitoes.

The introgression of antiviral strains of Wolbachia into Aedes aegypti mosquito populations is a public health intervention for the control of dengue. Plausibly, dengue virus (DENV) could evolve to bypass the antiviral effects of Wolbachia and undermine this approach. Here, we established a serial-passage system to investigate the evolution of DENV in Ae. aegypti mosquitoes infected with the wMel strain of Wolbachia. Using this system, we report on virus genetic outcomes after twenty passages of serotype 1 of DENV (DENV-1). An amino acid substitution, E203K, in the DENV-1 envelope protein was more frequently detected in the consensus sequence of virus populations passaged in wMel-infected Ae. aegypti than wild-type counterparts. Positive selection at residue 203 was reproducible; it occurred in passaged virus populations from independent DENV-1-infected patients and also in a second, independent experimental system. In wild-type mosquitoes and human cells, the 203K variant was rapidly replaced by the progenitor sequence. These findings provide proof of concept that wMel-associated selection of virus populations can occur in experimental conditions. Field-based studies are needed to explore whether wMel imparts selective pressure on DENV evolution in locations where wMel is established