Changes of benthic macroinvertebrates in Thi Vai River and Cai Mep Estuaries under polluted conditions with industrial wastewater

The pollution on the Thi Vai River has been spreading out rapidly over the two lasted decades caused by the wastewater from the industrial parks in the left bank of Thi Vai River and Cai Mep Estuaries. The evaluation of the benthic macroinvertebrate changes was very necessary to identify the consequences of the industrial wastewater on water quality and aquatic ecosystem of Thi Vai River and Cai Mep Estuaries. In this study, the variables of benthic macroinvertebrates and water quality were investigated in Thi Vai River and Cai Mep Estuaries, Southern Vietnam. The monitoring data of benthic macroinvertebrates and water quality parameters covered the period from 1989 to 2015 at 6 sampling sites in Thi Vai River and Cai Mep Estuaries. The basic water quality parameters were also tested including pH, dissolved oxygen (DO), total nitrogen, and total phosphorus. The biodiversity indices of benthic macroinvertebrates were applied for water quality assessment. The results showed that pH ranged from 6.4 – 7.6 during the monitoring. The DO concentrations were in between 0.20 – 6.70 mg/L. The concentrations of total nitrogen and total phosphorous ranged from 0.03 – 5.70 mg/L 0.024 – 1.380 mg/L respectively. Macroinvertebrate community in the study area consisted of 36 species of polychaeta, gastropoda, bivalvia, and crustacea, of which, species of polychaeta were dominant in species number. The benthic macroinvertebartes density ranged from 0 – 2.746 individuals/m2 with the main dominant species of Neanthes caudata, Prionospio malmgreni, Paraprionospio pinnata, Trichochaeta carica, Maldane sarsi, Capitella capitata, Terebellides stroemi, Euditylia polymorpha, Grandidierella lignorum, Apseudes vietnamensis. The biodiversity index values during the monitoring characterized for aquatic environmental conditions of mesotrophic to polytrophic. Besides, species richness positively correlated with DO, total nitrogen, and total phosphorus. The results confirmed the advantage of using benthic macroinvertebrates and their indices for water quality assessment

Antibacterial activity of Piper betle extracts on Helicobacter pylori and identification of potential compounds

Helicobacter pylori is one of the most common infectious bacteria in the world that causes gastric diseases leading to cancer. The increase of multiple antibiotic resistance rates of H. pylori have been reported worldwide. Thus, development of novel drugs is urgently required. Piper betle has many therapeutic values in traditional medicine. In this study, therefore, we investigated antibacterial activity of P. betle extracts and their fractions against a H. pylori strain isolated in Vietnam. The agar disk diffusion assay showed inhibition zone of ethyl acetate extract and methanol extract from P. betle leaf that of were 46 mm and 32 mm in diameter, respectively. After fractionation of the ethyl acetate extract through silica gel column chromatography, two peaks, PD2 and PD3, out of 12 fractions showed the strongest antibacterial activity. PD2 was sub-fractionated further by re-chromatography on the silica gel column, and subfraction TK12 gave best resolution on LC-MS analysis. Finally, 4 potential compounds, quercetrin, calodenin B, vitexin and plicatipyrone, were identified in TK12 fraction.

Developments in the Right to Defence for Juvenile Offenders Since Vietnam’s Ratification of the Convention on the Rights of the Child

This article examines Vietnam’s legal changes and law enforcement practices in regards to the right to defence of juvenile offenders since Vietnam ratified the United Nations Convention on the Rights of the Child in 1990. A combination of research methods is employed, including document analysis, statistical analysis, and selected case studies. The findings of the research indicate that Vietnam has demonstrated considerable improvement in acknowledging the right to defence of juvenile offenders in its law. The contemporary Vietnamese regulations are similar to the CRC’s requirements about legal assistance for juvenile offenders. The implementation of the law, however, confronts difficulties as juvenile offenders and their parents’ misunderstand the right to defence, and the procedure-conducting persons and defence councils’ lack commitment to their responsibilities. Therefore, Vietnam needs more effective mechanisms in order to realise the right to defence for juvenile offenders, closing the gap between the rights on paper and in practice

The impacts of talent management and organizational justice on turnover intention in the public sector : Regional differences in Vietnam

政策研究大学院大学 / National Graduate Institute for Policy Studies博士（政策研究） / Ph.D. in Advanced Policy Studies論文審査委員: 高田 寛文（主査）, 高橋 和志, Guanie LIM, 菊地 端夫（明治大学）, 諸星 穂積application/PDFGRIPS Global Governance Program (G-cube)doctoral thesi

The roles of teachers in implementing educational innovation

Since the late 1990s there has been a top-down movement to reform teaching and learning approaches in Vietnam. An important component of this reform is to change the traditional teaching and learning approach into cooperative learning. However, cooperative learning has failed to make its impact on the current teaching and learning approach. This paper examines one of the most important constraints on the implementation of cooperative learning in Vietnam, namely, perceptions of Vietnamese teachers toward the roles and responsibilities of teachers in class. It argues that many principles of cooperative learning are in serious conflict with traditional perceptions of Vietnamese teachers regarding the nature of teaching and learning. Therefore, policymakers and educators need to take cautious steps when implementing such radical approaches in Vietnamese educational settings. If they want to obtain support from teachers, they cannot merely borrow the original version of the innovation. Rather, they need to take various modifications into consideration

Current and Future Household Livelihood Adaptation to Changing Social-Ecological Context - A Case Study in the Rural Coastal Areas of the Vietnamese Mekong Delta and Red River Delta

The Vietnamese Mekong Delta and Red River Delta are among global coastal deltas pronounced for their high vulnerability to hazards and climate variability while playing a key role in socio-economic development nationally. Therefore, examining the patterns and details of adaptation in these deltas are significant in the future under climate change. The two deltas have experienced drastic social-ecological changes in the last three decades which are projected to become more extensive. This dissertation offers a conceptual framework to study their changing complex context in response to firstly, the knowledge gaps in understanding the details and process of adaptation of these vulnerable communities, and secondly, the research need of framing and operationalizing the social-ecological integrative approach. This dissertation thus contributes to the interdisciplinary literature by addressing the fragmentation caused by separating disciplines and the case-study based research on environmental change adaptation. The findings show that the households’ livelihood shifts in the case study are determined by the combination and interaction of social and climatic drivers. The livelihood-change typology approach considers multiple dimensions and the dynamics of livelihood shifts at the household level and thereby allows further identification of enablers and barriers to adaptation. The future adaptation is examined using scenarios hypothesizing social and environmental changes to project emerging trends of change. Linking to the concepts of integrative social-ecological relationship, livelihood dynamics, and processual approach to adaptation, these results emphasize the process of change with the interactions between the society and the environment, as well as among actors or scales of adaptive actions. The insights into the diverse coastal areas of the two Vietnamese deltas showcase a good example of the complex social-ecological context which proves the need for an integrative approach to study adaptation. Based on the main findings complemented by an in-depth discussion on the critical role of policy interventions in Viet Nam, implications and outlook were made to call for further efforts of researchers and practitioners to facilitate more adaptive pathways of vulnerable communities

Online Load Balancing for Network Functions Virtualization

Network Functions Virtualization (NFV) aims to support service providers to deploy various services in a more agile and cost-effective way. However, the softwarization and cloudification of network functions can result in severe congestion and low network performance. In this paper, we propose a solution to address this issue. We analyze and solve the online load balancing problem using multipath routing in NFV to optimize network performance in response to the dynamic changes of user demands. In particular, we first formulate the optimization problem of load balancing as a mixed integer linear program for achieving the optimal solution. We then develop the ORBIT algorithm that solves the online load balancing problem. The performance guarantee of ORBIT is analytically proved in comparison with the optimal offline solution. The experiment results on real-world datasets show that ORBIT performs very well for distributing traffic of each service demand across multipaths without knowledge of future demands, especially under high-load conditions

Zooplankton from Can Giuoc River in Southern Vietnam

In this study, the variables of zooplankton and water quality were investigated in the Can Giuoc River, Southern Vietnam. Zooplankton was monitored in April and September 2015 at 5 sampling sites in the river. Some basic water quality parameters were also tested, including pH, total suspended solid (TSS), dissolved oxygen (DO), biological oxygen demand (BOD5), inorganic nitrogen (NH4+), dissolved phosphorus (PO43-), and coliform. The zooplankton biodiversity indices were applied for the water quality assessment. The results showed that pH ranged from 6.7 to 7.6 during the monitoring. The TSSs were between 34–117 mg/L. The DO and BOD5 were from 0.6 to 3.8 mg/L and from 6.3 to 13.2 mg/L, respectively. The NH4+ and PO43- concentrations ranged from 0.44 to 3.23 and from 0.08 to 1.85 mg/L, respectively. The coliform number was between 9.3x103–9.3x104 MPN/100 mL. The zooplankton analyses showed that there were 31 species of coelenterates, rotatoria, oligochaetes, cladocerans, copepods, ostracods, mysidacea, and 8 larval types. Thereof, the species of copepods were dominant in the species number. The zooplankton density ranged from 9 500 to 23 600 individuals/m3 with the main dominant species of Moina dubia (Cladocera), Thermocyclops hyalinus, Acartia clausi, Oithona similis (Copepoda), and nauplius copepods. The biodiversity index values during the monitoring were from 1.47 to 1.79 characteristic of mesotrophic conditions of the aquatic environment. Besides, the species richness positively correlated with pH, TSS, DO, BOD5, NH4+, PO43-, and coliform, while the zooplankton densities got a positive correlation with DO, BOD5, NH4+, PO43-, and coliform. The results confirmed the advantage of using zooplankton and its indices for water quality assessment