Land Use/Land Cover Mapping Using Multitemporal Sentinel-2 Imagery and Four Classification Methods-A Case Study from Dak Nong, Vietnam

Information on land use and land cover (LULC) including forest cover is important for the development of strategies for land planning and management. Satellite remotely sensed data of varying resolutions have been an unmatched source of such information that can be used to produce estimates with a greater degree of confidence than traditional inventory estimates. However, use of these data has always been a challenge in tropical regions owing to the complexity of the biophysical environment, clouds, and haze, and atmospheric moisture content, all of which impede accurate LULC classification. We tested a parametric classifier (logistic regression) and three non-parametric machine learning classifiers (improved k-nearest neighbors, random forests, and support vector machine) for classification of multi-temporal Sentinel 2 satellite imagery into LULC categories in Dak Nong province, Vietnam. A total of 446 images, 235 from the year 2017 and 211 from the year 2018, were pre-processed to gain high quality images for mapping LULC in the 6516 km(2) study area. The Sentinel 2 images were tested and classified separately for four temporal periods: (i) dry season, (ii) rainy season, (iii) the entirety of the year 2017, and (iv) the combination of dry and rainy seasons. Eleven different LULC classes were discriminated of which five were forest classes. For each combination of temporal image set and classifier, a confusion matrix was constructed using independent reference data and pixel classifications, and the area on the ground of each class was estimated. For overall temporal periods and classifiers, overall accuracy ranged from 63.9% to 80.3%, and the Kappa coefficient ranged from 0.611 to 0.813. Area estimates for individual classes ranged from 70 km(2) (1% of the study area) to 2200 km(2) (34% of the study area) with greater uncertainties for smaller classes.Peer reviewe

Graptolites from Silurian (Llandovery Series) sedimentary deposits attributed to a forearc setting, Co To Formation, Co To archipelago, northeast Vietnam

Newly collected graptolites from the Co To Formation, Co To archipelago, NE Vietnam, comprise assemblages indicative of two biostratigraphical levels within the lower Silurian, Llandovery Series, Telychian Stage: the co-occurrence of Spirograptus turriculatus and Torquigraptus proteus? suggests an interval most likely within the upper part of the Spirograptus turriculatus Biozone or 'Monograptus' crispus Biozone, whilst Oktavites spirally and Monoclimacis cf. suhgeinitzi identify the Oktavites spiralis Biozone. The graptolites provide important biostratigraphical evidence for the age of the upper part of the lower Co To Formation, biostratigraphical ties between the NE Vietnamese succession of the Bac Bo Region and graptolite assemblages of the Long Dai Formation in the Viet-Lao Region of central Vietnam, and include the new species Monograptus hanutlus sp. nov. co-occurring with S. turriculatus, which is perhaps an ancestral form to the later Telychian species Monograptus drepanoformis. We also report the lirst chitinozoans, including Belonechitina, from the Co To Formation

SYSTEM THEORY BASED MULTIPLE BEAMFORMING

In this paper, the problem of analysis and design of large-scale multiple beamforming system is considered by system theory approach. We consider the response of system parameters by set of objective functions in a critical condition, which is unable to access measurement data or the data size is large. The reduced-order model is built and the robust solution is found for a multiple beamforming system. The Monte Carlo simulation results show that the proposed multiple beamforming system yields significant performance against over existing methods

Uptake capacity of metals (Al, Cu, Pb, Sn, Zn) by Vetiveria Zizanioides in contaminated water in the Dong Xam metal production trade village, Thai Binh, Vietnam

This study presents an experiment of metal contaminated water treatment under controlled environment conditions to investigate the uptake capacity of metals by Vetiveria Zizanioides to treat contaminated water from a metal production trade village, Dong Xam, Thai Binh, Vietnam. Vetiver was grown in two pot culture experiments TB10, TB6 with solutions containing respective concentrations of Al, Cu, Pb, Sn and Zn of 2.5, 55.6, 0.15, 7.7 and 24.4 mg from contaminated water in the Dong Xam metal production trade village for a period of 36 days. Vetiver has the higher tolerance to Al, Cu, Pb, Sn and Zn than other plant species. The roots (hereafter R) are high Al hyperaccumulators, concentrating 17 up to 30 folds more than “reference plant”. The upper parts of shoots (hereafter S1, S2, and S3) are 1.2 folds higher. Cu concentration in the root and shoot is up to 660 and 46.2 mg/kg, respectively. Vetiver can withstand and survive at Cu concentration of 46 mg/L in contaminated water that is markedly higher than other plants that can last only in solution with Cu concentration ranging 20-100 mg/kg. The translocation of Pb from root to shoot was 41%. Sn is more accumulated in the top, in which shoot/root ratio varied from 82% to 277% in the top, and increased to the top (by order S3/RS2/RS1/R). Zn could be translocated from roots and accumulated in shoots of vetiver. The ratio shoot/root obtains up to 46%. The present results demonstrated that vetiver had the high tolerance to trace metals Al, Cu, Pb, Sn and Zn in vegetation. This plant has a potential phytoremediation of metals in contaminated soil and wastewater from trade villages of Vietnam and other countries.References Adriano D.C., 1992. Biochemistry of trace metals. Lewis Publishers. Boca Raton, New York. 513 pp. Baker D.E., 1976. Acid soils. In Proc. of Workshop on Plant Adaptation to Mineral Stress in Problem Soils. Wright J. Ed. Cornell University. Ithaca. No4, 127. Becker H., 1992. Hedging against erosion. Agric. Res. 12, p.8-10. Braude G.L., Nash A.M., Wols W.J., 1980. Cadmium and lead content of soybean products. J. Food Sci., 45, 1187. Broyer T.C., Johnson C.N. and Paull R.E., 1972. Some aspects of lead in plant nutrition. Plant Soil. V36, p.301. Chiu K.K., Ye Z.H., Wong M.H., 2005. Enhanced uptake of As, Zn, and Cu by Vetiveria zizanioides and Zea mays using chelating agents. Chemosphere, 60, p.1365-1375. Chiu K.K., Ye Z.H., Wong M.H., 2006. Growth of Vetiveria zizanioides and Phragmities australis on Pb/Zn and Cu mine tailings amended with manure compost and sewage sludge: A greenhouse study. Bioresource Technology, 97, p.158-170. Cull, R.H., Hunter, H., Hunter, M., and Truong, P.N.,  2000.  Application of Vetiver Grass Technology in off-site pollution control.  II.  Tolerance of Vetiver grass towards high levels of herbicides under wetland conditions.  Proceedings of the Second International Vetiver Conference, Phetchaburi, Thailand, January 2000. Dabin P., Marafante E. et al., 1978. Adsorption, distribution and binding of cadmium and zinc in irrigated rice plants. Plant soil, 50, p. 329. Foy C.D., Chaney R.L. and White M.C., 1978. The physiology of metal toxicity in plants. Annu. Rev. Physiol. 29, p.511. Frank R., Stonefield K.I. and Suda P. 1979. Metals in agricultural soils of Ontario. Can. J. Soil Sci., 59, p.99. Grimshaw R G., 1989. A review of existing soil conservation technologies, and a proposed method of soil conservation using contour farming practices backed by vetiver grass hedge barriers. In Proc. vetiver Grass Seminar at the Int. Agric. Centre in Wageningen, The Netherlands, January, 1989. Hung-Yu Lai, Zueng-Sang Chen, 2004. Effects of EDTA on solubility of cadmium, zinc, and lead and their uptake by rainbow pink and vetiver grass. Chemosphere, 55, p.421- 430. Jensen K., Stephenson G., Hunt, L., 1977. Detoxification of atrazine in three Gramineae subfamilies. Weed Sci. 25, p.212-220. Kabata-Pendias Alina and Pendias Henryk, 2001. Trace elements in soils and plants. 3rd ed. CRC Press, Inc. Boca Raton, Florida, 413pp. Leckie J. O. and Davis J. A., 1979. Aqueous environmental chemistry of copper. In Copper in Environment (ed. J. O. Nriagu). Wiley, New York, pp.90-121. Markert B., 1992. Establishing of “reference plant” for inorganic characterization of different plant species by chemical fingerprinting. Water, Air, and Soil Pollution, 64: p.533-538. Mejare M., Bulow L., 2001. Metal-binding proteins and peptides in bioremediation and phytoremediation of heavy metals. Trends in Biotechnology, 19, p.67-73. Mickovski S.B., Beek L.P.H van and Salin F., 2005. Uprooting of vetiver uprooting resistance of vetiver grass (Vetiveria zizanioides). Plant and Soil, 278, p.33-41. Rommey E.M., Wallace A., and Alexander G.V., 1975. response of bush bean and barley to tin applied to soil and to solution culture. Plant Soil, 42, p.585. Sanita di Toppi L, Gabbrielli R. 1999. Response to cadmium in higher plants. Environ Exp Bot; 41:p.105-130. Schlesinger W. H. 2004. Treatise on geochemistry. Volume 8 Biogeochemistry. Executive editors H. D. Holland and K. K. Turekian. First edition 2004. Elsevier-Pergamon, Oxford. Steven T. S., Paul R. A., Ricarda N. K., 1999. Aquaculture sludge removal and stabilization within created wetlands. Aquacult. Eng. 19, p.81-92. Sylvie M., Muriel R., Patrick R., Jean-Paul S., 2006. Conjugation of atrazine in vetiver (Chrysopogon zizanioides Nash) grown in hydroponics. Environmental and Exp. Botany, 56, p.205-215. Tordoff G.M., Baker, A.J.M., Willis, A.J., 2000. Current approaches to the revegetation and reclamation of metalliferous mine wastes. Chemosphere, 41, p.219-228. Truong P. and Loch R., 2004. Vetiver System for erosion and sediment control. In Proc. 13th International Soil Conservation Organisation Conference, Brisbane, Australia, July 2004. pp.1-6. Truong P.N., 1996. Vetiver grass for land rehabilitation. In: Proceedings of the First International Vetiver Conferences, Thailand, pp.49-56. Truong P.N. and Baker D., 1998. Vetiver Grass System for Environmental Protection. Technical Bulletin N0. 1998/1.  Pacific Rim Vetiver Network, Office of the Royal Development Projects Board, Bangkok, Thailand. Truong P.N. and Hart B., 2001.  Vetiver System for Wastewater Treatment. Technical Bulletin NO. 2001/2.  Pacific Rim Vetiver Network, Office of the Royal Development Projects Board, Bangkok, Thailand. Veldkamp J. F., 1999. A revision of Chrysopogon Trin., including Vetiveria Bory (Poaceae) in Thailand and Malesia with notes on some other species from Africa and Australia. Austrobaileya 5: p.522-523. Wilde E.W., Brigmon R.L., Dunn D.L., Heitkamp M.A., Dagnan D.C., 2005. Phytoextraction of lead from firing range soil by Vetiver grass. Chemosphere, 61, p.1451-1457. World Bank, 1990. Vetiver Grass - The Hedge Against Erosion, 3rd ed. Washington D.C. Xia H.P., 2004. Ecological rehabilitation and phytoremediation with four grasses in oil shale mined land. Chemosphere, 54, p.345-353. Yahua C., Zhenguo S., Xiangdong L., 2004. The use of vetiver grass (Vetiveria zizanioides) in the phytoremediation of soils contaminated with heavy metals. Applied Geochemistry, 19, p.1553-1565. Yang B., Shu W.S., Ye Z.H., Lan C.Y., Wong M.H., 2003. Growth and metal accumulation in vetiver and two Sesbania species on lead/zinc mine tailings. Chemosphere, 52, p.1593-1600. Zhang J., 1998. Benefit and application future of sandy soils on windy Pingtan island. In: Vetiver Research and Development. Agricultural Science and Technology Press, China, pp.179-191. Zimdahl R.L., 1975. Entry and movement in vegetation of lead derived from air and soil sources. Paper presented at 68th Annu. Meeting of the Air Pollution Control Association, Boston, Mass., June 15, 1975, 2.

Perspective Chapter: Uptake Capacity of Metals (Al, Cu, Pb, Sn, Zn) in Contaminated Water Metal Production Trade Village Dong Xam, Thai Binh, Vietnam by <em>Vetiveria zizanioides</em>

This chapter describes experiments, carried out under controlled environment conditions to investigate the uptake capacity of metals (Al, Cu, Pb, Sn, and Zn) by Vetiveria zizanioides to treat contaminated water from “metal production trade village Dong Xam, Thai Binh, Vietnam.” The roots have a high hyperaccumulation capacity of Al, and it is much more than “reference plant” about 17- up to 30-folds, and the upper parts of shoots S2, and S3 are higher 1.2-fold. In vetiver plant the Cu concentration can be obtained up to 660 mg/kg in root, and 46.2 mg/kg in shoot, and it can withstand and be alive at 46 mg/L of contaminated solution. The lead translocation from root to shoot reached to about 41%. The tin is absorbed in the leaf chop with ratio: Root varied from 82% up to ∼277% in the leaf chop. The zinc may be moved from roots and accumulated by the shoots of vetiver. The ratio shoot: root gets up to 46%. The study shows that vetiver had the high tolerance to trace metals Al, Cu, Pb, Sn, and Zn than other species plants. This plant has potential for usage in the phytoremediation of metals contaminated soil and wastewater from trade villages of Vietnam and other countries

Le portail g-INFO pour surveiller la grippe Influenza A

Le portail g-INFO pour surveiller la grippe Influenza

One-pot preparation of alumina-modified polysulfone-graphene oxide nanocomposite membrane for separation of emulsion-oil from wastewater

In recent years, polysulfone-based nanocomposite membranes have been widely used for contaminated water treatment because they comprise properties such as high thermal stability and chemical resistance. In this study, a polysulfone (PSf) nanocomposite membrane was fabricated using the wet-phase inversion method with the fusion of graphene oxide (GO) and alumina (Al2O3) nanoparticles. We also showed that GO-Al2O3 nanoparticles were synthesised successfully by using a one-pot hydrothermal method. The nanocomposite membranes were characterised by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and water contact angle. The loading of GO and Al2O3 was investigated to improve the hydrophilic and oil rejection of the matrix membrane. It was shown that by using 1.5 wt.% GO-Al2O3 loaded in polysulfone, ~74% volume of oil was separated from the oil/water emulsion at 0.87 bar and 30 min. This figure was higher than that of the process using the unmodified membrane (PSf/GO) at the same conditions, in which only ~60% volume of oil was separated. The pH, oil/water emulsion concentration, separation time, and irreversible fouling coefficient (FRw) were also investigated. The obtained results suggested that the GO-Al2O3 nanoparticles loaded in the polysulfone membrane might have potential use in oily wastewater treatment applications

SCREENING ANTIBACTERIAL ACTIVITY OF VIETNAMESE PLANT EXTRACTS AGAINST HUMAN PATHOGENIC BACTERIA

Objectives: Infectious diseases caused by bacteria are a leading cause of death worldwide. Hence, the objectives of the study are aimed to evaluate the antibacterial activity against five human pathogenic bacteria of methanolic extracts from 66 plants collected from Vietnam. Methods: The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of methanol extracts of 66 plant species against five bacterial strains. Results: In this study, all the plant extracts were active against at least one train with MIC values ranging from 24 to 2048 μg/mL. Twenty-five plant extracts were active against all three Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus). Of these, the extracts of Macaranga trichocarpa (Rchb. f. and Zoll.) Mull. Arg. (Euphorbiaceae), Calophyllum inophyllum L. (Clusiaceae) and Caryodaphnopsis baviensis (Lecomte) Airy Shaw (Lauraceae) exhibited the highest antibacterial activity (MIC =24–128 μg/mL), followed by extracts of Betula alnoides Buch.- Ham. e × . D. Don (Betulaceae), Acronychia pedunculata (L.) Miq. (Rutaceae), Croton alpinus A. Chev. ex Gagnep. (Euphorbiaceae) (MIC =64–256 μg/mL). Furthermore, the extract of Rhus chinensis Mill. (Anacardiaceae) and Annona reticulata L. (Annonaceae) exhibited potent antibacterial activity against the two Bacillus species (MIC =32–64 μg/mL). Conclusion: Results of this study reveal that plant extracts from Vietnam have highly antibacterial activity against Gram-positive bacteria. These results suggest that Vietnamese plant extracts may be a rich source of antibacterial drugs

LBMT team at VLSP2022-Abmusu: Hybrid method with text correlation and generative models for Vietnamese multi-document summarization

Multi-document summarization is challenging because the summaries should not only describe the most important information from all documents but also provide a coherent interpretation of the documents. This paper proposes a method for multi-document summarization based on cluster similarity. In the extractive method we use hybrid model based on a modified version of the PageRank algorithm and a text correlation considerations mechanism. After generating summaries by selecting the most important sentences from each cluster, we apply BARTpho and ViT5 to construct the abstractive models. Both extractive and abstractive approaches were considered in this study. The proposed method achieves competitive results in VLSP 2022 competition.Comment: In Proceedings of the 9th International Workshop on Vietnamese Language and Speech Processing (VLSP 2022