Search

Vietnamese rivers are among the top ten contributors of anthropogenic debris to the ocean. However, there is limited empirical research documenting debris and its effects in Northern Vietnam. The goal of our research was to conduct the first baseline assessment of anthropogenic debris in the Red River. We aimed to understand the sources, accumulation patterns, and ecological effects of anthropogenic debris in the Red River (Song Hong) estuary. To assess debris patterns, we conducted standing stock debris surveys at sites in the mouth, and upstream of the Red River. To assess the ecological effects of anthropogenic debris on mangrove ecosystems, we measured mangrove diameter, canopy cover, and number of crab burrows/m2 in the same debris transects. Anthropogenic debris was found at all sites, and plastic was the most common material. We identified a non-significant trend, whereby ecological indices declined with increasing amounts of debris. Overall, our results demonstrate that anthropogenic debris is ubiquitous in the Red River estuary, composition varies among sites, and this debris may have adverse or neutral ecological effects on mangrove ecosystem health. Future work will assess community-level impacts of debris and other anthropogenic stressors (invasive species, chemical contaminants) at a larger spatial scale, and will assess the ecosystem-level impacts of debris removal. This research informs our fundamental understanding of how litter and other stressors impact biota in the Red River, while also contributing to our understanding of how management strategies for debris removal may be effective in large, Southeast Asian rivers. Also see: https://micro2022.sciencesconf.org/421425/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Cockroach is one of environmental bacterial indicator organism. Warm and humid condition, crowded population, street market and unseparated hospital sector in Ho Chi Minh city facilitate growth and propagate of pathogens in population with help of cockroaches. Study of enterobacterial profile of 40 household cockroaches captured in central districts of Ho Chi Minh city showed high percent of Klebsiella (50.8%) and Enterobacter (25.4%). Furthermore, we isolated 3 strains that resistant to 6 tested antibiotics (Ampicilline, Cefotaxime, Cefoxitin, Gentamicin, Streptomycine and Tetracyclin) such as Klebsiella pneumoniae, Enterobacter aerogenes and Enterobacter cloacae. These results showed that there are multidrug-resistant pathogen bacterial populations that could propagate via household cockroaches and threaten public health in Ho Chi Minh city.

Siderite pseudomorphous are formed by a natural hydrothermal transformation of ferrous carbonates into various iron oxides and hydroxides. In these compounds, small antiferromagnetic particles of αFe 2 O 3 and a FeOOH are bound by hydrated organic and inorganic (silicates, carbonates,... ) materials. N.G.R. along with magnetic studies have been performed. Mossbauer spectra show relaxation behaviour which cannot be related to superparamagnetism. Along with these studies, X rays, chemical and thermogravimetric analysis show that the sample composition is about 50% of αFe 2 O 3 , 50% of αFeOOH, 0.5% of γFeOOH. The mean size of the particles is about 250 A.