Assessing coral reef resilience for sustainable resource management (case study in Hon La island, Quang Binh province, Vietnam)

Coral reefs play a crucial role in providing ecosystem services for the coastal communities. However, the resilience of coral reefs is quickly degraded due to both global and local stressors, including climate change and marine pollution. Hon La island in Quang Binh province, Vietnam is one of the most important coral reef ecosystems. However, this area was heavily influenced by human activities and marine pollution. Therefore, the present study is implemented in order to evaluate the resilience of coral reefs in Hon La island for proposing sustainable development solutions. The proposed indicator framework consisted of three dimensions (coral diversity, biodiversity and environment), containing 26 indicators that potentially provided the quantified methods for decision makers to inform a range of management strategies in protecting coral reefs and using natural resources effectively. Results showed that coral reefs in Hon La island had a low resilient index, about 0.369 because of a degradation of diversity, seawater contaminated by oils and the high turbidity. Several solutions were proposed to enhance the resilience of coral reefs, including the establishment of marine protected areas; integrated management of the coastal zone; rehabilitation of coral reefs and application of co-management models. The theoretical framework from the present study could be potentially applied to evaluate the coral reef resilience in other marine areas in Vietnam with appropriate modification

INTEGRATED ASSESSMENT OF RISK LEVEL CAUSED BY HAZARDS IN THE COASTAL ZONE OF VIETNAM (CASES STUDY : CAM RANH-PHAN RI COASTAL ZONE)

Joint Research on Environmental Science and Technology for the Eart

CHARACTERIZATION AND MITIGATION OF VIETNAM COASTAL HAZARDS FOR SUSTAINABLE DEVELOPMENT

Joint Research on Environmental Science and Technology for the Eart

First record of Cantharellus minor from Vietnam with identification support from a combination of nrLSU and nrSSU phylogenetic analysis

Background: A previously identified sample XC02, which was collected from a pine forest (Pinus kesiya Royle ex Gordon), in Xuan Tho Commune, Da Lat, Lam Dong Province, Vietnam, was identified as Cantharellus minor based on morphology and nrLSU phylogeny analysis. Sequence analysis of multiple genes are becoming more and more common for phylogenetic analysis of mushrooms.Method: Total DNA was isolated from sample XC02. The primer NS1, NS4 were applied to amplify the target gene the nuclear ribosomal small subunit DNA (nrSSU). For phylogenetic analysis, individual and concatenated datasets (nrSSU and nrLSU-nrSSU) were constructed. Phylogenetic tree was constructed with MEGA 6.0 with a 1000 replicate bootstrap based on the neighbor joining, maximum likelihood, maximum parsimony method.  Results: A concatenated dataset containing a total of 14 sequences from Cantharellus, Craterellus (Cantharellaceae, Canthraellales) and Hydnum (Hydnaceae, Cantharellales) were constructed. For the specimen XC02, the phylogenies based on the first, second, and third datasets (nrLSU, nrSSU, and nrLSU-nrSSU) and the morphological analysis, reported in our previous study, strongly confirmed the identity of XC02 as Cantharellus minor.Conclusion: The combination between the morphological analysis and phylogenetic analysis is confirmed as the best approach for the identification of Cantharellus and other mushroom species that we collected in the Central Highlands, Vietnam.Keywords: nrLSU; Cantharellus, Cantharellus minor; nrSSU; nrLSU; phylogeny analysis; Vietna

Effect of TiO2 on the Gas Sensing Features of TiO2/PANi Nanocomposites

A nanocomposite of titanium dioxide (TiO2) and polyaniline (PANi) was synthesized by in-situ chemical polymerization using aniline (ANi) monomer and TiCl4 as precursors. SEM pictures show that the nanocomposite was created in the form of long PANi chains decorated with TiO2 nanoparticles. FTIR, Raman and UV-Vis spectra reveal that the PANi component undergoes an electronic structure modification as a result of the TiO2 and PANi interaction. The electrical resistor of the nanocomposite is highly sensitive to oxygen and NH3 gas, accounting for the physical adsorption of these gases. A nanocomposite with around 55% TiO2 shows an oxygen sensitivity of 600–700%, 20–25 times higher than that of neat PANi. The n-p contacts between TiO2 nanoparticles and PANi matrix give rise to variety of shallow donors and acceptor levels in the PANi band gap which enhance the physical adsorption of gas molecules

Statistical estimation of frictional coefficients of faults based on a structural dataset in the Tuy Hoa–Vung Tau Region, Viet Nam

This study estimates the shear friction coefficient from shear friction angles for the prediction of slip tendencies in the Tuy Hoa–Vung Tau region of Southern Vietnam. A dataset consisting of measured data of 355 fractured planes, striations, and unconformities in coastal areas as well as 239 offshore faults was analyzed based on the principles of statistical probability. As a result, 138 friction angles for the onshore and offshore faults were calculated based on shear fracture conjugate pairs. The goodness-of-fit test was used to define the probability distribution of the friction angles, which had a normal distribution. The acceptable average of friction angles for the onshore region with a reliability of more than 95% were in the range of 25.8–31.5°, which corresponds to frictional coefficients of 0.48–0.61. The acceptable average friction angles for the offshore region were relatively low at 23–31°, which corresponds to a frictional coefficient of 0.42–0.60. Owing to the heterogeneity of the fault system, the median value (19.12°) should be used as the lowest threshold value for slipping faults at all conditions. The recommended applicable average friction angles are 28.65° and 27° for the onshore and offshore regions, respectively. The estimation of the frictional coefficients is highly reliable, and it can be applied to other subsurface resource exploitation projects within the study area

Combating the COVID-19 Epidemic: Experiences from Vietnam.

The COVID-19 pandemic is spreading fast globally. Vietnam's strict containment measures have significantly reduced the spread of the epidemic in the country. This was achieved through the use of emergency control measures in the epidemic areas and integration of resources from multiple sectors including health, mass media, transportation, education, public affairs, and defense. This paper reviews and shares specific measures for successful prevention and control of COVID-19 in Vietnam, which could provide useful learning for other countries

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions