The status of southern white-cheeked gibbon (Nomascus siki) in Truong Son key biodiversity area

The Southern white-cheeked crested gibbon, Nomascus siki, is an endemic primate to Vietnam and Laos, and has been identified as a nationally and globally endangered species (EN). However, little information is known on the status of the species in Vietnam generally and in the Truong Son key biodiversity area (Truong Son KBA) particularly. In order to explore the current status of the species in the Truong Son KBA, we conducted field surveys in 2018 and 2019. Analysis of the survey data shows 149 groups of gibbon in the 4 study areas. Combined with results of similar-techniqued survey in 2016 on the same species in Khe Nuoc Trong forest, we identified at least 252 gibbon groups and estimated 425 gibbon groups in the entire Truong Son KBA. These gibbon groups are mainly distributed in medium-rich evergreen closed forests in mountainous areas of the west Truong Son KBA, adjacent to the Vietnam-Laos border.

An anatomical note on Moellendorffia eastlakeana (Mollendorff, 1882) a camaenid land snail from Vietnam (Gastropoda: Pulmonata: Camaenidae)

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Drastic variations in estuarine morphodynamics in Southern Vietnam: investigating riverbed sand mining impact through hydrodynamic modelling and field controls

Recent riverbed sand mining activities have modified estuarine morphology and sedimentation patterns in many Southeast Asian deltas. The Soai Rap Estuary along the Dong Nai River (one of the largest rivers in Southern Vietnam) is one of the most intensively mined areas in the region, where large-scale sand mining activities have started since the 1990′s. In this paper, we used hydrodynamic modelling (TELEMAC-2D) to investigate the estuarine morphological changes and sediment dynamics related to the intensive riverbed mining in the Soai Rap Estuary. After the hydraulic calibration and validation of the model, we simulate four scenarios: two with dredging, one with sand excavation, and a baseline condition. Our results show that dredging substantially changed the hydraulic regimes, morphological and sediment dynamics of the estuary. Compared to the baseline, dredging substantially influences flow velocity and tidal amplitude. These activities reduce the amount of sediment accumulating upstream by 18% to 36%, while increasing sediment deposition in the Soai Rap Estuary by 6% to 13%. Furthermore, sediment accumulation in the Ganh Rai Bay area decrease by 5% to 10% due to increased sediment transport from the sea to the estuary. Our modelled results also show that the mining pits (pockmarks) created by sand extractions efficiently trap sediment, causing discontinuities in the longitudinal transport of sediment and resulting morphological patterns. We conclude that the morphology and sediment transport regime of the Soai Rap estuary has been significantly altered by the river sand dredging. As such, we recommend that the local government put in place measures to ensure that sand extraction is carried out sustainably in the future, to minimise further alterations to the natural sedimentation patterns and geomorphology of this estuary.Ministry of Education (MOE)Nanyang Technological UniversityThis study is funded by University of Natural Resources and Envi-ronment, Ho Chi Minh City, Vietnam under the grant number CS.2022.11. It is also funded by the Nanyang Technological University (#SUG-NAP EP3/19) and Ministry of Education of Singapore (#Tier1 RT06/19, #Tier1 2021-T1-001-056 and #Tier2MOE-T2EP402A20-0001)

Establishment of cancer cell line originating from a patient with high-grade serous ovarian carcinoma

Aim: Ovarian cancer is a serious malignancy with high prevalence and mortality. Methods: We isolated and characterized an ovarian high-grade serous cancer cell line (M4) from a tumor of a Vietnamese patient with ovarian carcinoma. Results: The M4 cancer cell line showed good proliferation and stability in culture. Morphologically, the M4 cells showed similar characteristics to tumor cells such as a polyhedral shape, large irregular nuclei, high nuclear/cytoplasmic ratio, high nuclear density and expressing cancer markers like CA125, p53 and Ki67 markers. Conclusion: We have successfully isolated and characterized the M4 cell line from a Vietnamese patient with ovarian carcinoma