• Title/Summary/Keyword: Vietnam National University

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Sources of Resistance to Bacterial Wilt Found in Vietnam Collections of Pepper (Capsicum annuum) and Their Nuclear Fertility Restorer Genotypes for Cytoplasmic Male Sterility

  • Tran, Ngoc Hung;Kim, Byung-Soo
    • The Plant Pathology Journal
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    • v.28 no.4
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    • pp.418-422
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    • 2012
  • Eleven hot pepper accessions collected in Vietnam showed stable resistance to bacterial wilt as well-known resistance sources, MC4 and MC5, in repeated inoculation tests with different Ralstonia solanacearum isolates conducted from 2004 to 2010. Seven of these accessions (specifically KC981, KC1006, KC1021, KC1027, KC1045, KC1050, and KC1055) resulted in stable male sterile F1 plants in the crosses with a cytoplasmically male sterile (CMS) Chilseong (CMS-A, Srfrf ), and therefore, they were maintainers (CMS-B) with a genotype of Nrfrf. The rest (KC980, KC995, KC999, and KC1009) produced stable male fertile F1 plants in the crosses, and therefore, were restorers (CMS-C) with a genotype of N(S)RfRf. Therefore, the maintainer and restorer sources of resistance may be used in preference in breeding maternal (CMS and their maintainers) and paternal parents (restorers) for resistance to bacterial wilt, respectively, in the hybrid breeding system utilizing cytoplasmic male sterility.

RISK ANALYSIS FOR INDUSTRIAL PROJECT IN CONSTRUCTION PHASE: A MONTE-CARLO SIMULATION APPROACH

  • Soo-Yong Kim;Luu Truong Van;Han-Ki Ha;Nguyen Quoc Tuan
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.130-139
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    • 2007
  • This paper presents a study on risk analysis in terms of contractor's costs in construction phase in which Crystal ball (software of Decisioneering, UK) has been utilized as a main tool. To realize it, a questionnaire survey has been carried out to identify the dominant factors that strongly influence contractor costs in Vietnam. Based on results of questionnaire investigation, the survey identified three factors which were duration of each construction task, costs of reinforcing steel, and cement. Then a spreadsheet model was created in order to analyze risks. The study also indicates that the cost of reinforcing steel and cement are the cause of risks for contractors. According to the suggested model, contractors may foresee the probability of completion within the approved budget, and the possibility of earning in accordance with owner's payment conditions.

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CONSTRUCTION FATAL ACCIDENTS IN VIETNAM: AN EXPLORATORY STUDY

  • Soo-Yong Kim;Luu Truong Van;Yurl Hur
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.327-336
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    • 2007
  • Construction activities are characterized as hazardous work. Therefore, it is very imperative to explore comprehensively fatal accidents and safety performance in both developed and developing countries. The goal of this study was to look at the reasons behind fatal accidents in HCMC, Vietnam's largest city. The survey sample consists of 91 fatal accident cases in total that occurred in construction sites during the years 1996-2005 and were reported to the Department of Labor-Invalids-Social Affairs in HCMC. The study was conducted by means of field surveys with relevant individuals working in construction sites and statistical analyses. The research resulted in failing to wear/use PPE as unsafe acts and in poor safety management procedures/methods in sites as insecurely working conditions behind serious accidents in the construction. The paper stresses that accidents tended to occur more in state-owned companies than in others and involved more with masonry/welding people and workers without labor contracts than with other workers.

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Alpha-Glucosidase Inhibitory Activity of Saponins Isolated from Vernonia gratiosa Hance

  • Pham Van Cong;Hoang Le Tuan Anh;Le Ba Vinh;Yoo Kyong Han;Nguyen Quang Trung;Bui Quang Minh;Ngo Viet Duc;Tran Minh Ngoc;Nguyen Thi Thu Hien;Hoang Duc Manh;Le Thi Lien;Ki Yong Lee
    • Journal of Microbiology and Biotechnology
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    • v.33 no.6
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    • pp.797-805
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    • 2023
  • Species belonging to the Vernonia (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 - 3), designated as vernogratiosides A-C, from whole plants of V. gratiosa. Their structures were elucidated based on infrared spectroscopy (IR), one-dimensional (1D) and two-dimensional nuclear magnetic resonance (2D NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and electronic circular dichroism analyses (ECD), as well as chemical reactivity. Molecular docking analysis of representative saponins with α-glucosidase inhibitory activity was performed. Additionally, the intended substances were tested for their ability to inhibit α-glucosidase activity in a laboratory setting. The results suggested that stigmastane-type steroidal saponins from V. gratiosa are promising candidate antidiabetic agents.

In vitro gas and methane production of some common feedstuffs used for dairy rations in Vietnam and Thailand

  • N. T. D., Huyen;J. Th. Schonewille;W. F. Pellikaan;N. X. Trach;W. H. Hendriks
    • Animal Bioscience
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    • v.37 no.3
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    • pp.481-491
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    • 2024
  • Objective: This study determined fermentation characteristics of commonly used feedstuffs, especially tropical roughages, for dairy cattle in Southeast Asia. This information is considered relevant in the context of the observed low milk fat content and milk production in Southeast Asia countries. Methods: A total of 29 feedstuffs commonly used for dairy cattle in Vietnam and Thailand were chemically analysed and subjected to an in vitro gas production (GP) test. For 72 h, GP was continuously recorded with fully automated equipment and methane (CH4) was measured at 0, 3, 6, 9, 12, 24, 30, 36, 48, 60, and 72 h of incubation. A triphasic, nonlinear, regression procedure was applied to analyse GP profiles while a monophasic model was used to obtain kinetics related to CH4 production. Results: King grass and VA06 showed a high asymptotic GP related to the soluble- and non-soluble fractions (i.e. A1 and A2, respectively) and had the highest acetate to propionate ratio in the incubation fluid. The proportion of CH4 produced (% of GP at 72 h) was found to be not different (p>0.05) between the various grasses. Among the selected preserved roughages (n = 6) and whole crops (n = 4), sorghum was found to produce the greatest amount of gas in combination with a relatively low CH4 production. Conclusion: Grasses belonging to the genus Pennisetum, and whole crop sorghum can be considered as suitable ingredients to formulate dairy rations to enhance milk fat content in Vietnam/Thailand.

Metagenomic analysis of bacterial community structure and diversity of lignocellulolytic bacteria in Vietnamese native goat rumen

  • Do, Thi Huyen;Dao, Trong Khoa;Nguyen, Khanh Hoang Viet;Le, Ngoc Giang;Nguyen, Thi Mai Phuong;Le, Tung Lam;Phung, Thu Nguyet;Straalen, Nico M. van;Roelofs, Dick;Truong, Nam Hai
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.5
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    • pp.738-747
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    • 2018
  • Objective: In a previous study, analysis of Illumina sequenced metagenomic DNA data of bacteria in Vietnamese goats' rumen showed a high diversity of putative lignocellulolytic genes. In this study, taxonomy speculation of microbial community and lignocellulolytic bacteria population in the rumen was conducted to elucidate a role of bacterial structure for effective degradation of plant materials. Methods: The metagenomic data had been subjected into Basic Local Alignment Search Tool (BLASTX) algorithm and the National Center for Biotechnology Information non-redundant sequence database. Here the BLASTX hits were further processed by the Metagenome Analyzer program to statistically analyze the abundance of taxa. Results: Microbial community in the rumen is defined by dominance of Bacteroidetes compared to Firmicutes. The ratio of Firmicutes versus Bacteroidetes was 0.36:1. An abundance of Synergistetes was uniquely identified in the goat microbiome may be formed by host genotype. With regard to bacterial lignocellulose degraders, the ratio of lignocellulolytic genes affiliated with Firmicutes compared to the genes linked to Bacteroidetes was 0.11:1, in which the genes encoding putative hemicellulases, carbohydrate esterases, polysaccharide lyases originated from Bacteroidetes were 14 to 20 times higher than from Firmicutes. Firmicutes seem to possess more cellulose hydrolysis capacity showing a Firmicutes/Bacteroidetes ratio of 0.35:1. Analysis of lignocellulolytic potential degraders shows that four species belonged to Bacteroidetes phylum, while two species belonged to Firmicutes phylum harbouring at least 12 different catalytic domains for all lignocellulose pretreatment, cellulose, as well as hemicellulose saccharification. Conclusion: Based on these findings, we speculate that increasing the members of Bacteroidetes to keep a low ratio of Firmicutes versus Bacteroidetes in goat rumen has resulted most likely in an increased lignocellulose digestion.

Formation and Change of Production Network based on Customer-following Overseas Expansion of Korean Subcontractors: Electronic Industries in Hanoi Red River Delta, Vietnam (한국 하청기업의 해외동반진출과 생산 네트워크 형성 및 변화: 베트남 하노이 권역 전자산업을 사례로)

  • Kim, Seonghun
    • Journal of the Economic Geographical Society of Korea
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    • v.23 no.2
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    • pp.147-165
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    • 2020
  • The aim of this study is to find out Korean electronic industries' production network in Hanoi Red River Delta, Vietnam and its change based on customer-following overseas expansion. In-depth interviews with Korean subcontractors were conducted to examine the characteristics of customer-following overseas expansion of Korean subcontractors. Korean subcontracting corporations in electronic industries have expanded into Vietnam as the suppliers to Korean transnational corporations. Since 1990s, Korean corporations have invested into Vietnam but since late 2000s its industrial and geographical concentration has been shifted from textile and clothing industries in Southern Vietnam to electronics in Northern Vietnam. The customer-following overseas expansion of the subcontractors has emerged in three aspects: physical proximity, asymmetrical inter-firm relations and organizational embeddedness. During the process of customer-following overseas expansion, Korean electronic industry production network was transplanted into Vietnam and partially modified. This is because the company's hierarchy and difficulties in changing its trading relationship have affected the process of advancing into overseas markets. Korean transnational corporations seek to establish a stable suppliers through expansion accompanying with its subcontractors, and providing financial and non-financial support to its subcontractors.

The Impact of Earnings Quality on Firm Value: The Case of Vietnam

  • DANG, Hung Ngoc;NGUYEN, Thi Thu Cuc;TRAN, Dung Manh
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.3
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    • pp.63-72
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    • 2020
  • The study aims to investigate the impact level of earnings quality on firm value. The study has used data with 3,910 observations at listed firms on Vietnam Stock Exchange for the period from 2010 to 2018, and GLS regression analysis is employed in this research. Earnings quality is measured in the aspects of earnings management, earnings persistence, and timeliness of profitability. This study also considers a number of controlled variables that positively influence the firm's value such as firm size, fixed asset investment rate and dividend payout ratio. The results show that earnings quality is positively associated with firm value with having statistical significance. In contrast, some determinants negatively influence firm value such as financial leverage, ratio of market value to book value, and revenue growth. Determinants of firm size, the rate of investment in fixed assets, the rate of dividend payment positively affect the firm value. In contrast, determinants of financial leverage, revenue growth rate and market value to book value ratio are inversely related to firm value according to economic value, Tobin's Q or Price. Based on the findings, some recommendations are proposed for investors, management and policy makers as well in the context of emerging countries including Vietnam.

The Influence of Post-Traumatic Stress and Social Support on Depression of Vietnam Veterans (베트남 참전군인의 외상 후 스트레스와 사회적 지지가 우울에 미치는 영향)

  • Hyun, Hye-Sun;Kim, Tae-Yeol;Kim, Yun-Young
    • The Korean Journal of Health Service Management
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    • v.12 no.1
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    • pp.137-147
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    • 2018
  • Objectives : The purpose of this study was to identify the post-traumatic stress, social support, and depression of Vietnam veterans and the effects of post-traumatic stress and social support on depression. Methods : This study was carried out from June 2017 to September 2017 with the cooperation of the Korean Society of Veterans' Affairs and 250 Vietnamese veterans from D city were randomly sampled and collected. The collected data were used by SPSS 24.0 Statistics Program. Results : Social support was inversely correlated with post-traumatic stress (r=-.268, p<.001) and depression (r=-.333, p<.001), and post-traumatic stress and depression (r=.592, p<.001) were positively correlated. Post-traumatic stress and social support of veterans had a significant effect on depression, and post-traumatic stress and social support showed an explanatory power of 37.7% in depression. Conclusions : It is necessary to improve soldiers' mental health by mediating their post-traumatic stress and reducing their depression level by establishing a social support system.