244 research outputs found
Structural features of geostrophic circulation in open region of the South China Sea
On the basis of observation data of water temperature and salinity the mean seasonal geostrophic circulation in open region of the South China Sea (SCS) was computed by the dynamic method relative to the 800 decibar reference surface. The results of computation let go to following notices:
In both main monsoons (winter and summer) there are two main geostrophic eddies: the anticlockwise eddy in the northern and northwestern part, and the clockwise eddy in the southern part of the SCS with corresponding divergent and convergent zones. The main frontal zones go along the middle latitudes of the sea from the southern continental shelf of Vietnam to the area west of Luzon Island. The strength and stability of the current in winter are higher than in summer. The Kuroshio has an enough strong branch intruding into the SCS through Bashi Strait in winter creating in the sea the water structure similar to that of the Northwest Pacific subtropical and tropical regions. In summer the Kuroshio water can intrude directly only into the area southwest of Taiwan
Parasite Infection, Carcinogenesis and Human Malignancy.
Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity
HIỆN TRẠNG VÀ BIẾN ĐỘNG DIỆN TÍCH CÁC HỆ SINH THÁI BIỂN TIÊU BIỂU TRONG VỊNH NHA TRANG
Assessments of status and temporal changes in distribution of marine habitats in Nha Trang bay were conducted by using interpretation of remote sensing (Orbview 3, SPOT5, ALOS-AVNIR2 and Landsat 8-LCM) and aerial images in combination with ground truthing at 50 key sites representing coral reefs (25 sites), seagrass beds (10 sites), mangroves (5 sites), rocks (5 sites) and sand (5 sites) in 2015. A total of 812 ha of key marine habitats was recorded in 2015 including 754.1 ha of coral reefs, 52.4 ha of seagrass beds and 5.4 ha of mangroves. There was a notable decline in areas of the above marine habitats in the period of 2002 - 2015, in which 64 ha of seagrass beds (equivalent to 45%; mainly at Bai Tien, Phu Quy, Mui Nam and Vung Me, Đam Gia, Song Lo) and 117.4 ha of coral reefs (equivalent to 13.5%; mainly at Dam Gia, Duong De, Song Lo, Bai Tien and Eo Co) have been lost with an exception of increase of 3.1 ha of mangroves by new transplantation project conducted by Nha Trang MPA authority in Dam Bay during the last few years. The decline in the areas of coral reefs and seagrass beds has been caused by expansion and reclaimation of infrastructure for community and tourism development in recent years.Đánh giá hiện trạng phân bố các hệ sinh thái biển tiêu biểu (rừng ngập mặn, thảm cỏ biển và rạn san hô) trong vịnh Nha Trang được thực hiện bằng việc giải đoán ảnh viễn thám Landsat 8-LCM đa phổ, ảnh Google Earth kết hợp với kiểm định thực địa tại 50 điểm chìa khóa (san hô: 25 điểm, cỏ biển: 10 điểm, cây ngập mặn: 5 điểm, đá: 5 điểm và cát: 5 điểm) trong năm 2015. Việc đánh giá sự biến động phân bố các hệ sinh thái nói trên được thực hiện bằng phương pháp phân tích hồi cố dựa trên kết quả giải đoán ảnh viễn thám và ảnh máy bay theo các đợt đánh giá tổng thể đa dạng sinh học tiến hành trong năm 2002 (Orbview 3 và ảnh máy bay), 2005 (SPOT5) và 2007 (ALOS-AVNIR2). Kết quả nghiên cứu xác định có trên 812 ha diện tích các hệ sinh thái tiêu biểu (gồm 754,1 ha rạn san hô, 52,4 ha thảm cỏ biển và 5,4 ha rừng ngập mặn) phân bố trong vịnh Nha Trang vào năm 2015. Nhìn chung, có sự biến động khá lớn diện tích các hệ sinh thái tiêu biểu trong giai đoạn 2002 - 2015, trong đó thảm cỏ biển bị mất 64 ha (tương đương 45%; chủ yếu ở khu vực Bãi Tiên, Phú Quý, Mũi Nam và Vũng Me, Đầm Già, Sông Lô) và rạn san hô bị mất 117,4 ha (tương đương 13,5%, Đầm Già, Đường Đệ, Sông Lô, Bãi Tiên, Eo Cỏ); riêng rừng ngập mặn tăng 3,1 ha do trồng mới ở khu vực Đầm Báy trong giai đoạn nói trên. Nguyên nhân làm mất diện tích các hệ sinh thái là do việc phát triển cơ sở hạ tầng ven bờ và ven đảo để phát triển khu dân cư và cơ sở du lịch trong thời gian qua
Dairy Value Chain In Vietnam: Evidences from Bavi Area
Dairy farming, in Vietnam, existed in the early twentieth century thanks to the favorable natural advantage. During many difficult periods, the Vietnam’s dairy industry has developed constantly and contributed significantly to the food needs ensuring. However, Vietnam’s dairy industry still could not satisfy the domestic milk demand. Retail milk prices in Vietnam are very high, whereas the price of milk sold by the dairy farmers is very low. The cause stems from the control of dairy companies in the quantity and quality of milk. Moreover, that control caused an imbalance in the profits and benefits of each actor in the dairy value chain. This study, hence, finds out the distribution of benefits, costs, value-added among the actors, and problems in the practical management in dairy milk value chain with specific focus on Bavi as the case study
Inverse analysis for transmissivity and the Red river bed's leakage factor for Pleistocene aquifer in Sen Chieu, Hanoi by pumping test under the river water level fluctuation
Aquifer parameters and riverbed hydraulic resistance to an aquifer have an important role in the quantitative assessment of groundwater sources, especially the aquifer recharge from river. The analytical determination of aquifer parameters and riverbed hydraulic resistance to the aquifer is rather complicated in case if the water level in the river fluctuates before and during the pumping test time. This is especially true for Pleistocene aquifer along the Red River in Hanoi city, where the riverbed has been changed very much during the recent decades. A trial-error inverse analysis in the parameters' determination by a group pumping test data obtained with a test located close to the Red river bank in Sen Chieu area, Phuc Tho district, Hanoi city was carried out. Before and during the pumping test time the water level in the river changed five times. The results have shown that the Pleistocene aquifer has a relatively high hydraulic conductivity of 55.5 m/day, which provides a good role in the transport of a large volume of water recharged by the river to the abstraction wells located near the river. The aquifer storage coefficient had lightly decreased with the pumping time, which is corresponding to the physical nature of that the aquifer stativity is a function of the aquifer pressure. A special point is worthwhile to be noted that the Red river bed resistance to the Pleistocene is very low, about 0.537 days, which is corresponding to the increase of the distance from the river bank further from the well in 28.4 m to have the river as a specified water level boundary of the aquifer. In contrast, the 1990's investigations had found that the Red river bed resistance to the Pleistocene aquifer to be about 130 days (Tran Minh, 1984), which is corresponding to the increase of the distance from the river bank further from the well in a thousand of meters to have the river as a specified water level boundary for the aquifer.ReferencesChristensen S., 2000. On the estimation of stream flow depletion parameters by drawdown analysis. Ground Water, 38(5), 726-734. Fetter C.W., 2001. Applied Hydrogeology. Prentice Hall-Upper Saddle River, NJ 07458. Fletcher G. Driscoll., 1987. Groundwater and Wells. Published by Johnson Division, St. Paul, Minnesota 55112, USA.Fox G.A., 2004. Evaluation of a stream aquifer analysis test using analytical solutions and field data. Journal of the American Water Resources Association. 40(3), 455-763. Hunt B., Wei J. and Clausen B., 2001. A stream depletion field experiment. Ground Water 39(2), 283-289. John H. Cushman and Daniel M. Tartakovsky (Editors), 2017. The Handbook of Groundwater Engineering. Third Edition. CRC Press. Taylors Francis Group. 6000 Broken Sound Parkway NW, Suite 300.Lough H.K. and Hunt B., 2006. Pumping test evaluation of stream depletion parameters. Ground Water. Jul-Aug, 44(4), 540-546. Mironhenco V.A. and Shestakov V.M., 1974. Fundamentals of hydromechanics. Publishers "Nedra", Moscow, Russia. Ne-Zheng Sun, 1994. Inverse Problems in Groundwater Modeling. Cluwer Academic Publishers. Nguyen Minh Lan, 2014. Report on "Study of the relationship between the Red river and groundwater, proposal of methods of determination of groundwater abstraction potential along the Red river from Son Tay to Hung Yen". Code: TNMT.02.33. Nguyen Quoc Thanh and Nguyen Van Hoang, 2007. Hydrogeomechanical processes affecting the stability of Red river dike's foundation and in the Son Tay-Ha Noi area. Hanoi Geoengineering 2007. International Conference Proceedings, 120-123. Nguyen The Chuyen, Vu Ngoc Duc, Dao Trong Tu, Nguyen Van Hoang, 2017. Study on determination of effective porosity and longitudinal dispersivity of aquifer and the application to field tracer injection test in Mo Lao, Ha Dong area, Hanoi, Vietnam. Vietnam National University Journal of Science, 33(1), 1-15. Nguyen Van Giang, Nguyen Ba Duan, Le Ngoc Thanh, Noboru Hida, 2014. Hydro-geophysical Techniques to Aquifer Locating and Monitoring for Industrial zone north Thang Long and Quang Minh, Hanoi. Vietnam J. Earth Sci., 36(3), 221-232. Doi: 10.15625/0866-7187/36/3/5905. Nguyen Van Hoang, 2016. Modelling of water pollution. Vietnam Academy of Science and Technology Publishers. Pham Dinh, 2016. Report on "Study of the effects of the sand and gravel excavation in the Red river and Thai Binh river system on the flow regime and bed load regime for supporting sustainable management and planning of sand and gravel excavation" code ĐTĐL.2012-T/27. Vietnam Academy of Water Resources. Sophocleous M., 2001. Interactions between groundwater and surface water: the state of the science. Hydrogeology Journal, 10, 52-67. Tong Ngoc Thanh, Trieu Duc Huy, Nguyen Van Kenh, Tong Thanh Tung, Pham Ba Quyen, Nguyen Van Hoang, 2017. Methodology of determining effective porosity and longitudinal dispersivity of aquifer and the application to field tracer injection test in Southern Hanoi, Vietnam. Vietnam J. Earth Sci., 39(1), 57-75. Doi: 10.15625/0866-7187/39/1/9228. Tran Minh, 1984. Report on "Results of groundwater investigation in Hanoi area". Northern Union for Water Resources Planning and Investigation. Trieu Duc Huy (Project head), 2015. Proposal "Groundwater protection in large cities (Hanoi city)" and the project's implementation data and materials. Vietnam National Center for Water Resources Planning and Investigation. Vu Tat Uyen and Le Manh Hung, 2011. Warning on the consequences of sand and gravel excavation in the Red river more than the annual bed load supply. Journal of Water Resources Science and Technology, 3, 2-6
Optimization of Total Flavonoid Extraction From the Helicteres hirsuta Lour. Roots by Bath Ultrasound Assisted method and cytotoxic activities of these Flavonoids
This study was carried out to optimize the various approaches to analyze the effects of various variables on the total flavonoid content extraction from the roots of Helicteres hirsuta L. The existence of various compounds in the methanol fraction was accessed by using LC-MS/MS analysis. The results of the study identified the ideal parameters such as times (30 minutes); methanol solvent concentration (50%); ultrasonic frequency (12 Hz); and material/solvent ratio [1:30 (w/v)] for extracting the highest total flavonoids from the roots of H. Hirsuta. The study's results suggested that the total flavonoid value was 3.52684 (mg Catechin/g extract). The verified experiment obtained an actual value of 5.205 (mg Catechin/g extract). Further, the results of the study suggested the presence of 20 compounds of a flavonoid nature (66.667%) appearing in the purified methanol fractional extract. These compounds can inhibit DPPH free radicals at 50%, with an IC50 value of 536.760 g/mL, and they also have inhibitory activity on the growth of cancer cell lines with IC50 values ranging from 115.81 and 219.17g/mL. The human leukemia cell line (HL-60) exhibits the most significant cytotoxic response to a methanol extract from H. hirsuta root with an IC50 value of 115.81 g/mL
Methodology of determining effective porosity and longitudinal dispersivity of aquifer and the application to field tracer injection test in Southern Hanoi, Vietnam
Groundwater field pumping out and tracer injection test had been carried out at Nghiem Xuyen commune, Thuong Tin district, Hanoi where salinized and fresh groundwater boundary exist in the Pleistocene aquifer. The test was executed with pumping out rate of 9l/sec and tracer injection rate of 0.7l/sec of water with the salt concentration of 5g/l. The interpretation and analysis of the groundwater solute transport parameters by the field pumping out and tracer injection test is a rather complicated and delicate task due to the variability of the temporal boundary conditions. The test results have shown that although the tracer injection time is rather long (up to 60 hours), the tracer breakthrough curve of the tracer concentration of the pumped out water has its very specific characteristic shape, however with some variation due to the test invisible variability of conditions. The results of the parameter identification based on the method of least squares have given effective porosity of 0.32 and longitudinal dispersivity of 2.5m (which give the hydrodynamic dispersion of from D=250m2/day right outside the pumping well screen to D=18m2/day right outside the injection well screen). The minimal sum of squares of the differences between the observed and model normalized tracer concentration is 0.00119, which is corresponding to the average absolute difference between observed and model normalized concentrations of 0.0355 (while 1 is the worse and 0 is the best). The results have also shown that the maximal tracer concentration right outside the pumping out well screen is 6.1 times greater than the tracer concentration of the pumped out water. The distortion flow coefficient αW (the ratio between the flow rate through the injection well section without its presence) and the groundwater flow into the tracer injection well is from 18.66 (at the early testing time) to 10.76 (at the later testing time).References Bear J. and Verruijt A., 1987. Modeling groundwater flow and pollution, D. Reidel Publishing Company, Dordrecht, Holand, 414pp. Brouyère S. 2008. Modeling tracer injection and well-aquifer interactions: a new mathematical and numerical approach. Water Resour. Res, 39(3), 1070-1075. Drost, W., D. Klotz, A. Koch, H. Moser, F. Neumaier, and W. Rauert, 1968. Point dilution methods of investigating ground water flow by means of radioisotopes. Water Resour. Res., 4(1), 125-146. Fetter C.W., 2001. Applied Hydrogeology. Prentice Hall Inc. New Jersey 07458, 598pp. Hall, S.H., 1996. Practical single-well tracer methods for aquifer testing, In: Tenth National Outdoor Action Conference and Exposition, National Groundwater Association, Colombus, Ohio, USA, 11pp. Huyakorn P.S., and Pinder G. F., 1983. Computational Methods in Subsurface Flow. Academic Press, New York, 473pp. Nguyen Van Hoang, 2016. Modeling of pollutant transport in water environment. Vietnam Academy of Science and Technology Publishers, 201pp. Nguyen Van Hoang (project head) (2014-2017). Science and Technology Proposal: Study on the finite element modeling software for simulation of groundwater flow and solute transport by groundwater-application to aquifer in Central plain of Vietnam" codded ĐT.NCCB-ĐHƯD.2012-G/04 supported by NAFOSTED-MOST. Nguyen Van Hoang, Dinh Van Thuan, Nguyen Duc Roi, Le Duc Luong, 2012. Study on the impact of the Tri An reservoir on its downstream groundwater level regime. Vietnam Journal of Earth Sciences, 34(4), 465-476. Nguyen Van Hoang, Pham Lan Hoa, Le Thanh Tung, 2014. Study on the accuracy of the numerical modeling of the groundwater movement due to spatial and temporal discretization. Vietnam Journal of Earth Sciences, 36(4), 424-431. Nguyen Van Hoang and Nguyen Duc Roi, 2015. Finite element method in estimation of lag time of rainfall recharge to Holocene groundwater aquifer in Hung Yen province. Vietnam Journal of Earth Sciences, 37(4), 355-362. Nguyen Van Hoang, Nguyen Thanh Cong, Pham Lan Hoa, Le Thanh Tung, 2016. Study on the characteristics of salinity transport in 2D cross-section unconfined aquifer. Vietnam Journal of Earth Sciences, 38(1), 66-78. Novakowski, K.S., 1992. An evaluation of boundary conditions for one-dimensional solute transport, 1, Mathematical development. Water Resour. Res., 28(9), 2399-2410. Polubarinova-Kotrina P. IA., 1977. Theory of Groundwater. Moscow Science Publishers. 664pp. Tong Thanh Tung, 2015. Specialized report: Interpretation and analysis of aquifer parameters for pumping test at group-well test CHN5 in Nghiem Xuyen-Thuong Tin-Hanoi. Project "Groundwater protection in large cities (city: Hanoi)". Vietnam National Center for Water Resources Planning and Investigation-MoNRE, 16pp. Trieu Duc Huy (Project head), 2015. Science and Technology Proposal: Groundwater protection in large cities (city: Hanoi) approved by MoNRE Minister in Decision 1557/QD-BTNMT dated 30th Aug. 2013. Vietnam National Center for Water Resources Planning and Investigation-MoNRE. Vitaly A. Zlotnik and John David Logan, 1996. Boundary Conditions for Convergent Radial Tracer Tests and Effect of Well Bore Mixing Volume. Papers in the Earth and Atmospheric Sciences, 159pp. Zienkiewicz O. C. and Morgan K., 1983. Finite Elements and Approximation. Academic Press, 328p.
Circulating Biomarkers for Early Diagnosis of Hepatocellular Carcinoma
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, which is also often fatal. An early and accurate diagnosis is a decisive step towards the survival of the patients. Molecular biology improved significantly the prognosis of liver cancers through learned use of tumor markers like proteantigens, cytokines, enzymes, isoenzymes, circulating RNAs, gene mutations and methylations. Nevertheless, much improvement is still achievable and needed in this area, which is crucial in order to make an early diagnosis and monitor the progression of the disease. We present in this review what we believe to be the most relevant data regarding tissue and serum biomarkers related to HCC
Genetic Evidence of Functional Ficolin-2 Haplotype as Susceptibility Factor in Cutaneous Leishmaniasis
Background: Ficolin-2 coded by FCN2 gene is a soluble serum protein that plays an important role in innate immunity. In this study, we analyzed five functional polymorphisms of the FCN2 gene for their possible association with cutaneous leishmaniasis. Methods: Initially we screened 40 Syrian Arabs for the entire FCN2 gene. We investigated the contribution of FCN2 functional variants in 226 patients with cutaneous leishmaniasis and 286 healthy controls from Syria. Polymorphisms in the promoter regions (2986G/A, 2602G/A, 24A/G) of the FCN2 gene were assessed by TaqMan real time PCR, whereas polymorphisms in exon8 (+6359C/T and +6424G/T) were assessed by DNA sequencing. We also measured serum ficolin-2 levels in 70 control Syrian Arabs and correlated the serum concentrations to FCN2 genotypes and haplotypes respectively. Results: Nine new FCN2 variants including two with non synonymous substitutions in exon6 and exon8 were observed. The homozygous genotypes +6424T/T were distributed more in controls and none in patients (P = 0.04). The AGACG haplotype were observed more in patients than in controls (OR = 2.0, 95%CI 1.2–3.4, P = 0.006). The serum ficolin-2 levels were significantly distributed among the reconstructed ficolin-2 haplotypes (P,0.008) and the haplotype AGACG was observed with higher ficolin-2 levels in 70 control individuals. Conclusion: Our results demonstrate a significant association of FCN2 AGACG haplotype with cutaneous leishmaniasis in a Syrian Arab population. These first results provide a basis for a future study that could confirm or disprove possibl
- …