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Sample records for delta vietnam electronic

  1. Holocene delta plain development in the Song Hong (Red River) delta, Vietnam

    Science.gov (United States)

    Funabiki, Ayako; Haruyama, Shigeko; Quy, Nguyen Van; Hai, Pham Van; Thai, Dinh Hung

    2007-05-01

    Holocene delta plain development was investigated based on three sediment cores analyzed in detail from the Song Hong (Red River) delta plain in Vietnam. Two cores (DA and PD) from the western delta plain showed both the landward limit of the transgressive estuarine system in the valley incised during the last glacial maximum and floodplain evolution since the middle Holocene. On the other hand, a core (TL) from the eastern delta plain revealed a Pleistocene terrace buried under the deltaic sediments and a slow accumulation rate compared with that in the west. At 8 cal ky BP, the shoreline migrated very close to the present Hanoi city area, and the sedimentary environment changed to tidal flat or salt marsh. Hanoi city marks the northern limit of shoreline transgression. The mangrove swamp expanded from 8 to 5 cal ky BP to the landward limit of the delta plain. Subsequently, the shoreline migrated seaward as a result of delta progradation and sea-level lowering. From 5 cal ky BP, the emerged area evolved into a floodplain and natural levees formed along the abandoned river channels on the western delta plain, but at 2 cal ky, archeological sites indicate that the Holocene terrace in the eastern delta plain was still inundated.

  2. Biological Observations on the Mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, R. H.; Meilvang, A. S.; Cedhagen, Tomas;

    2009-01-01

    Aspects of the population biology of the mudskipper, Pseudapocryptes elongatus, (Cuvier, 1816) were studied in Bac Lieu Province in the Lower Mekong Delta, Vietnam, including sex ratio, length–frequency distribution, sexual dimorphism, hepatosomatic index (HSI), female gonadosomatic index (GSI...

  3. Livelihood Capabilities and Pathways of Shrimp Farmers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Phung Ha, Ha; Dijk, van J.W.M.; Bosma, R.H.; Sinh, L.X.

    2013-01-01

    Shrimp farming is a major livelihood activity in the Mekong Delta in the southernmost part of Vietnam. The Vietnamese government has promoted shrimp farming as a way to reduce poverty, provide employment opportunities and increase exports to support economic development. The shrimp farming system,

  4. Global and local governance of shrimp farming in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Thu, H.

    2012-01-01

    The Mekong Delta is one of seven ecological regions in Vietnam where aquaculture and shrimp products are internationally traded and the shrimp farmers are firmly embedded in a global system of production and trade. The growth of shrimp aquaculture, in addition to population growth and higher levels

  5. Rice-freshwater prawn (Macrobrachium rosenbergii) farms in the Mekong Delta, Vietnam

    OpenAIRE

    Quang, Nguyen

    1993-01-01

    Aquaculture in riceland has been practiced in Mekong Delta, Vietnam for a long time and integrated rice-freshwater prawn (Macrobrachium rosenbergii) farming has become more and more popular. The integrated farming systems developed and practiced by farmers in the area to produce more food and more cash crops are presented and discussed.

  6. Water pollution by Pangasius production in the Mekong Delta, Vietnam: causes and options for control

    NARCIS (Netherlands)

    Pham Thi Ahn,; Kroeze, C.; Bush, S.R.; Mol, A.P.J.

    2010-01-01

    In this paper, we analyse water pollution caused by farming and processing Pangasianodon hypophthalmus in the Mekong Delta of Vietnam. The results show that 1 tonne of frozen fillets releases 740 kg BOD, 1020 kg COD, 2050 kg TSS, 106 kg nitrogen and 27 kg phosphorus, of which wastewater from fish po

  7. Developing Permanent Vegetable Production Systems for the Red River Delta, Vietnam

    NARCIS (Netherlands)

    Pham Thi Thu Huong, Huong; Everaarts, A.P.; Neeteson, J.J.; Struik, P.C.

    2012-01-01

    The year-round demand for commercially produced vegetables in South-East Asia is growing rapidly because of ongoing population growth and urbanisation. Vegetable production plays an important role in the rural economy of the Red River Delta, the economic centre of northern Vietnam. Field vegetables,

  8. Exploring the climate change concerns of striped catfish producers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, L.A.; Truong, M.H.; Verreth, J.A.J.; Leemans, R.; Bosma, R.H.; Silva, De S.S.

    2015-01-01

    This study investigated the perceptions on and adaptations to climate change impacts of 235 pangasius farmers in the Mekong Delta, Vietnam. Data were collected using semi-structured household surveys in six provinces, from three regions along the Mekong river branches. A Chi-Square test was used to

  9. Livelihood Capabilities and Pathways of Shrimp Farmers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Phung Ha, Ha; Dijk, van J.W.M.; Bosma, R.H.; Sinh, L.X.

    2013-01-01

    Shrimp farming is a major livelihood activity in the Mekong Delta in the southernmost part of Vietnam. The Vietnamese government has promoted shrimp farming as a way to reduce poverty, provide employment opportunities and increase exports to support economic development. The shrimp farming system, h

  10. Farmers' knowledge, perceptions and practices in mango pest management in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, van P.; Cuc, N.T.T.; Huis, van A.

    2001-01-01

    A survey of mango farmers' knowledge, perceptions and practices in pest management was conducted during the dry season of 1998 in the Mekong Delta, Vietnam. Identification and control of pests was often based on damage symptoms, rather than on recording of causal agents. Damage caused by the seed-bo

  11. Morphodynamics of a cyclic prograding delta: the Red River, Vietnam

    NARCIS (Netherlands)

    Maren, D.S. van

    2004-01-01

    River deltas are inhabited by over 60% of the world population, and are, consequently, of paramount agricultural and economical importance. They constitute unique wetland envi ronments which gives river deltas ecological importance as well. Additionally, many deltas contain large accumulations of oi

  12. Magnitude of arsenic pollution in the Mekong and Red River Deltas - Cambodia and Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Michael [Swiss Federal Institute of Aquatic Science and Technology (Eawag), CH-8600 Dubendorf (Switzerland)]. E-mail: michael.berg@eawag.ch; Stengel, Caroline [Swiss Federal Institute of Aquatic Science and Technology (Eawag), CH-8600 Dubendorf (Switzerland); Trang, Pham Thi Kim [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Hung Viet, Pham [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Sampson, Mickey L. [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Leng, Moniphea [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Samreth, Sopheap [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Fredericks, David [Phnom Penh (Cambodia)

    2007-01-01

    Large alluvial deltas of the Mekong River in southern Vietnam and Cambodia and the Red River in northern Vietnam have groundwaters that are exploited for drinking water by private tube-wells, which are of increasing demand since the mid-1990s. This paper presents an overview of groundwater arsenic pollution in the Mekong delta: arsenic concentrations ranged from 1-1610 {mu}g/L in Cambodia (average 217 {mu}g/L) and 1-845 {mu}g/L in southern Vietnam (average 39 {mu}g/L), respectively. It also evaluates the situation in Red River delta where groundwater arsenic concentrations vary from 1-3050 {mu}g/L (average 159 {mu}g/L). In addition to rural areas, the drinking water supply of the city of Hanoi has elevated arsenic concentrations. The sediments of 12-40 m deep cores from the Red River delta contain arsenic levels of 2-33 {mu}g/g (average 7 {mu}g/g, dry weight) and show a remarkable correlation with sediment-bound iron. In all three areas, the groundwater arsenic pollution seem to be of natural origin and caused by reductive dissolution of arsenic-bearing iron phases buried in aquifers. The population at risk of chronic arsenic poisoning is estimated to be 10 million in the Red River delta and 0.5-1 million in the Mekong delta. A subset of hair samples collected in Vietnam and Cambodia from residents drinking groundwater with arsenic levels > 50 {mu}g/L have a significantly higher arsenic content than control groups (< 50 {mu}g/L). Few cases of arsenic related health problems are recognized in the study areas compared to Bangladesh and West Bengal. This difference probably relates to arsenic contaminated tube-well water only being used substantially over the past 7 to 10 years in Vietnam and Cambodia. Because symptoms of chronic arsenic poisoning usually take more than 10 years to develop, the number of future arsenic related ailments in Cambodia and Vietnam is likely to increase. Early mitigation measures should be a high priority.

  13. Sedimentation patterns in floodplains of the Mekong Delta - Vietnam

    Science.gov (United States)

    Van Manh, Nguyen; Merz, Bruno; Viet Dung, Nguyen; Apel, Heiko

    2013-04-01

    Quantification of floodplain sedimentation during the flood season in the Mekong Delta (MD) plays a very important role in the assessment of flood deposits for a sustainable agro-economic development. Recent studies on floodplain sedimentation in the region are restricted to small pilot sites because of the large extend of the Delta, and the complex channel. This research aims at a quantification of the sediment deposition in floodplains of the whole Mekong Delta, and to access the impacts of the upstream basin development on the sedimentation in the Delta quantitatively. To achieve this, a suspended sediment transport model is developed based on the quasi-2D hydrodynamic model of the whole Mekong Delta developed by Dung et al. (2011). The model is calibrated and validated using observed data derived from several sediment measurement campaigns in channel networks and floodplains. Measured sediment data and hydrodynamic model quantify the spatio-temporal variability of sediment depositions in different spatial units: individual dyke compartments, and the sub-regions Plain of Reeds, Long Xuyen Quadrangle and the area between Tien River and Hau River. It is shown that the distribution of sediment deposition over the delta is highly depended on the flood magnitude, that in turn drives the operation policy of flood control systems in floodplains of the Mekong Delta. Thus, the sedimentation distribution is influenced by the protection level of the dyke systems in place and the distance to the Tien River and Hau River, the main branches of the Mekong in the Delta. This corroborates the main findings derived from data analysis obtained from a small scale test site by Hung et al, (2011, 2012a). Moreover, the results obtained here underlines the importance of the main channels for the sediment transport into the floodplains, and the deposition rate in floodplains is strongly driven by the intake locations and the distance from these to the main channels as well.

  14. Climate Change Impact On Mekong Delta of Vietnam in recent years

    Science.gov (United States)

    Le, L. T. X., III

    2015-12-01

    In recent years, the climate change signal increase globally. Abnormal changes of weather tends increasingly detrimental to human life, such as natural disasters occur with increasing level of more severe. Climate change is one the biggest challenges, and is a potential threat to humans. The impact of climate change increases the number and extent of the disaster fierce exists as typhoons, floods, droughts ... Global warming and sea level rise increases the area of flooding, saline intrusion and erosion in the delta region may cause farmers to lose the opportunity to produce, source of life their only. Impact of climate change on people in the community, but poor farmers in the developing countries like our country, women are the most severe consequences In this section, we summarize changes in climate on the territory of Vietnam, especially in Mekong Delta evaluate causes and its relationship to changes in global climate and region. Along with the analysis of characteristics of climate changes over time and through space to help the evolution of the standard deviation (average deviation from the standard of the period from 1971 to 2015) may indicate that the characteristic gas scenes took place related to global climate change ... Vietnam's territory stretches over approximately 15 latitude, the terrain is very complex, located in the interior full of tropical Southeast Asia. Vietnam climate strongly influenced by the Asian monsoon, monsoon and Northern Hemisphere especially the ENSO activity in the equatorial region and the Pacific Ocean. Climate Vietnam abundant and diversified, with strong ties to the region and globally.

  15. Biological Observations on the Mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, R. H.; Meilvang, A. S.; Cedhagen, Tomas

    2009-01-01

    Aspects of the population biology of the mudskipper, Pseudapocryptes elongatus, (Cuvier, 1816) were studied in Bac Lieu Province in the Lower Mekong Delta, Vietnam, including sex ratio, length–frequency distribution, sexual dimorphism, hepatosomatic index (HSI), female gonadosomatic index (GSI), ...... in salinities ranging from freshwater to 50 ppt. Gut content analysis revealed that P. elongatus is a herbivore, feeding mainly on pennate diatoms (93% of the diet)....

  16. The spatial distribution of vulnerability to the health impacts of flooding in the Mekong Delta, Vietnam

    Science.gov (United States)

    Phung, Dung; Rutherford, Shannon; Dwirahmadi, Febi; Chu, Cordia; Do, Cuong Manh; Nguyen, Thuy; Duong, Nam Chi

    2016-06-01

    Flooding causes significant public health issues. The Mekong Delta has been considered the region to be the most vulnerable to flooding in Vietnam. This study assessed the spatial vulnerability of the health impacts of flooding in the Mekong Delta region, Vietnam. This study applied a vulnerability assessment framework which was computed as the function of three dimensions: exposure, sensitivity, and adaptive capacity. The indicators for each dimension were derived from the relevant literature, consultations with experts, and data availability. An analytic hierarchy process (AHP) and a principal component analysis (PCA) were used to determine the weight of indicators. Vulnerability indexes (VIs) were then computed for each province. A total of 29 indicators (sensitivity index, 14; adaptive capacity index, 13; and exposure index, 2) were employed to evaluate the vulnerability to the health impacts of flooding at a provincial level. The results of AHP revealed that the highest VIs were found in the Dong Thap and An Giang provinces (VI, 1.948 and 1.574, respectively). VIs were distributed with higher indexes in upstream provinces close to a river than in coastal provinces. PCA generated three components from the 29 indicators, and the VIs computed from the PCA method are in substantial agreement with the AHP method (ICC = 0.71, p Vietnam. Individual plans for health preparedness and adaption to flooding should be developed for each province in the Mekong Delta region.

  17. Groundwater arsenic in the Red River delta, Vietnam

    DEFF Research Database (Denmark)

    Jessen, Søren

    Afhandlingen omhandler problemerne med høje koncentrationer af arsen i grundvandet i Den Røde Flod deltaet (Vietnam), der bebos af omkring 11 millioner mennesker. Forgiftning med arsen fra grundvand brugt til drikkevand kan give alvorlige og ultimativt dødelige sygdomme. Afhandlingen beskriver...... hvorledes koncentrationen af arsen i grundvandet er styret af den geologiske dannelseshistorie. Denne viden er væsentlig i forbindelse med planlægningen af den indsats, der er nødvendig for at afhjælpe arsenproblemet i Den Røde Flod deltaet. I afhandlingen beskrives desuden de hydrogeologiske og geokemiske...... processer, der medfører forhøjede koncentrationer af arsen i grundvandet. Blandt forskere er der generelt udbredt enighed om, at kilden til arsen i grundvandet er naturlig, og at arsen sidder bundet til oxider af jern (rust-partikler) på sedimenter af ler og sand, der transporteres fra Himalaya og aflejres...

  18. Late Holocene depositional environments and coastal evolution of the Mekong River Delta, Southern Vietnam

    Science.gov (United States)

    Lap Nguyen, Van; Ta, Thi Kim Oanh; Tateishi, Masaaki

    2000-08-01

    The Mekong River Delta in Southern Vietnam is a tide-dominated delta and has been formed by the Mekong River system. The sediments are dominantly fine grained and were deposited in the receiving basin with slight inclination of pre-existing deposits in the South China Sea and Gulf of Thailand. Around 6000 to 5000 yr BP maximum Holocene transgression occurred and seawaves surrounded uplands of the Late Pleistocene terrace, basement rock and weathered land in the northern parts of the delta. Double notches were undercut by seawaves on the limestone hill in Hatien at about 4.5 and 2.5 m above present sea level. Marine deposits prevailed throughout the delta. During the highstand and regressions of relative sea level over the last 4550 yr BP, delta progradation has produced a great flat-plain of 62,520 km 2. This extremely fast progradation could be due to: (a) very high sediment supply depositing in the slight inclination of the receiving basin; (b) neotectonic movements and relative sea-level changes; (c) widespread mangrove forests playing an important role to enhance sediment accumulation. Former mangrove marshy deposits were significantly developed in the Plain of Reeds and Longxuyen Quadrangle. Mangrove marshes have also been developing well in the Camau Peninsula and present coastlines. Moreover, regressions over the last 4550 yr BP have produced many distinct sets of relict beach ridges which are useful in distinguishing the former coastlines and evolutionary history of the delta.

  19. Bathymetry of the Hong and Luoc River Junction, Red River Delta, Vietnam, 2010

    Science.gov (United States)

    Kinzel, Paul J.; Nelson, Jonathan M.; Toan, Duong Duc; Thanh, Mung Dinh; Shimizu, Yasuyuki

    2012-01-01

    The U.S. Geological Survey, in collaboration with the Water Resources University in Hanoi, Vietnam, conducted a bathymetric survey of the junction of the Hong and Luoc Rivers. The survey was done to characterize the channel morphology of this delta distributary network and provide input for hydrodynamic and sediment transport models. The survey was carried out in December 2010 using a boat-mounted multibeam echo sounder integrated with a global positioning system. A bathymetric map of the Hong and Luoc River junction was produced which was referenced to the datum of the Trieu Duong tide gage on the Luoc River.

  20. Hydrogeologic reconnaissance of the Mekong Delta in South Vietnam and Cambodia

    Science.gov (United States)

    Anderson, Henry R.

    1978-01-01

    The present report describes the results of a hydrogeologic reconnaissance in the Mekong Delta region by the writer, a hydrogeologist of the U.S. Geological Survey, while on assignment as an adviser to the Vietnamese Directorate of Water Supply from October 1968 to April 1970 under the auspices of the U.s. Agency for International Development. The delta of the Mekong River, comprising an area of about 70,000 square kilometres in South Vietnam and Cambodia, is an almost featureless plain rising gradually from sea level to about 5 metres above sea level at its apex 300 kilometres inland. Most of the shallow ground water in the Holocene Alluvium of the delta in Vietnam is brackish or saline down to depths of 50 to 100 metres. Moreover, in the Dong Thap Mu?oi (Plain of Reeds) the shallow ground water is alum-bearing. Locally, however, perched bodies of fresh ground water occur in ancient beach and dune ridges and are tapped by shallow dug wells or pits for village and domestic water supply. The Old Alluvium beneath the lower delta contains freshwater in some areas, notably in the Ca Mau Peninsula and adjacent areas, in the viciniy of Bau Xau near Saigon, and in the Tinh Long An area. Elsewhere in the lower delta both the Holocene and Old Alluvium may contain brackish or saline water from the land surface to depths of as much as 568 metres, as for example in Tinh Vinh Binh. Ground water in the outcrop area of Old Alluvium northwest of Saigon is generally fresh and potable, but high iron and low pH are locally troublesome. Although considerable exploratory drilling for ground water down to depths of as much as 568 metres has already been completed, large areas of the delta remain yet to be explored before full development of the ground-water potential can be realized. With careful development and controlled management to avoid saltwater contamination, however, it is estimated that freshwater aquifers could provide approximately 80 percent of existing needs for village

  1. Development of sea level rise scenarios for climate change assessments of the Mekong Delta, Vietnam

    Science.gov (United States)

    Doyle, Thomas W.; Day, Richard H.; Michot, Thomas C.

    2010-01-01

    Rising sea level poses critical ecological and economical consequences for the low-lying megadeltas of the world where dependent populations and agriculture are at risk. The Mekong Delta of Vietnam is one of many deltas that are especially vulnerable because much of the land surface is below mean sea level and because there is a lack of coastal barrier protection. Food security related to rice and shrimp farming in the Mekong Delta is currently under threat from saltwater intrusion, relative sea level rise, and storm surge potential. Understanding the degree of potential change in sea level under climate change is needed to undertake regional assessments of potential impacts and to formulate adaptation strategies. This report provides constructed time series of potential sea level rise scenarios for the Mekong Delta region by incorporating (1) aspects of observed intra- and inter-annual sea level variability from tide records and (2) projected estimates for different rates of regional subsidence and accelerated eustacy through the year 2100 corresponding with the Intergovernmental Panel on Climate Change (IPCC) climate models and emission scenarios.

  2. PermVeg: A model to design crop sequences for permanent vegetable production systems in the Red River Delta, Vietnam

    NARCIS (Netherlands)

    Pham Thi Thu Huong, Huong; Everaarts, A.P.; Berg, van den W.; Neeteson, J.J.; Struik, P.C.

    2014-01-01

    The constraints in current vegetable production systems in the Red River Delta, Vietnam, in which vegetables are rotated with flooded rice, called for the design of alternative systems of permanent vegetable production. The practical model, PermVeg, was developed to generate vegetable crop sequences

  3. The Innovative Structure Solution for Preventing Salt Intrusion and Retaining Freshwater In Mekong Delta VietNam

    NARCIS (Netherlands)

    Hong, S.T.; Vrijling, J.K.; Stive, M.J.F.

    2013-01-01

    In the Mekong Delta Vietnam, the construction of sluices with the purpose of retaining fresh water and preventing salt water intrusion potentially plays a very important role. However, the structures constructed in small rivers according to local or traditional technology revealed many disadvantages

  4. Influence of pesticide information sources on citrus farmer's knowledge, perception and practices in pest management, Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, van P.; Hai, T.V.; Thas, O.; Huis, van A.

    2002-01-01

    In 1998-99, about 150 citrus farmers and 120 pesticide sellers were interviewed in Can Tho and Dong Thap province, Mekong Delta, Vietnam. Media, pesticide sellers and extension staff had different influences on farmers' pest perception and management practices depending on the region and intensity

  5. Using fuzzy logic modelling to simulate farmers’ decision-making on diversification and integration in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Bsma, R.; Kaymak, U.; Van den Berg, J.; Udo, H.

    2010-01-01

    To reveal farmers’ motives for on-farm diversification and integration of farming components in the Mekong Delta, Vietnam, we developed a fuzzy logic model (FLM) using a 10-step approach. Farmers’ decision-making was mimicked in a three-layer hierarchical architecture of fuzzy inference systems, usi

  6. Using fuzzy logic modelling to simulate farmers' decision-making on diversification and integration in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Bosma, R.H.; Kaymak, U.; Berg, van den J.; Udo, H.M.J.; Verreth, J.A.J.

    2011-01-01

    To reveal farmers’ motives for on-farm diversification and integration of farming components in the Mekong Delta, Vietnam, we developed a fuzzy logic model (FLM) using a 10-step approach. Farmers’ decision-making was mimicked in a three-layer hierarchical architecture of fuzzy inference systems, usi

  7. Simulated Impacts of Climate Change on Current Farming Locations of Striped Catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, L.A.; Dang, V.H.; Bosma, R.H.; Verreth, J.A.J.; Leemans, R.; Silva, De S.S.

    2014-01-01

    In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta's economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these i

  8. Influence of pesticide information sources on citrus farmer's knowledge, perception and practices in pest management, Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, van P.; Hai, T.V.; Thas, O.; Huis, van A.

    2002-01-01

    In 1998-99, about 150 citrus farmers and 120 pesticide sellers were interviewed in Can Tho and Dong Thap province, Mekong Delta, Vietnam. Media, pesticide sellers and extension staff had different influences on farmers' pest perception and management practices depending on the region and intensity o

  9. Evaluating farmers' knowledge, perceptions and practices: a case study of pest management by fruit farmers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, van P.

    2000-01-01

    After the Doi moi policy reform of Vietnam in 1986, the government has increasingly emphasized diversification of agricultural production into high value crops. Over the period 1985-1995, fruit production in the Mekong Delta increased from 92,100 to 175,700 ha mainly due to better land tenure securi

  10. The Innovative Structure Solution for Preventing Salt Intrusion and Retaining Freshwater In Mekong Delta VietNam

    NARCIS (Netherlands)

    Hong, S.T.; Vrijling, J.K.; Stive, M.J.F.

    2013-01-01

    In the Mekong Delta Vietnam, the construction of sluices with the purpose of retaining fresh water and preventing salt water intrusion potentially plays a very important role. However, the structures constructed in small rivers according to local or traditional technology revealed many disadvantages

  11. The Influence of Changes in the Market Environment on Economic Production Characteristics of Pangasius Farming in the Mekong Delta (Vietnam)

    NARCIS (Netherlands)

    Binh, Van T.; Haese, D' M.F.C.; Speelman, S.; Haese, D' L.

    2010-01-01

    The Mekong Delta in Vietnam has become an important production area for pangasius. The importance of the sector in providing an income to many households means that it is relevant to study its economic production characteristics. In this article we use a stochastic cost frontier model to assess the

  12. Mosquitoes and their potential predators in rice agroecosystems of the Mekong Delta, southern Vietnam.

    Science.gov (United States)

    Ohba, Shin-Ya; Huynh, T T Trang; Le, Loan Luu; Ngoc, Huu Tran; Hoang, San Le; Takagi, Masahiro

    2011-12-01

    Culex tritaeniorhynchus, Cx. gelidus, and Cx. quinquefasciatus, known vectors of Japanese encephalitis (JE), are distributed in rice agroecosystems in Asian countries. Very few integrated studies on the breeding habitats of rice-field mosquitoes, including JE vectors, have been conducted in Vietnam. We investigated the mosquito fauna and potential predators in 8 rice growing areas in the Mekong Delta region of southern Vietnam, during the wet and dry seasons of 2009. Mosquitoes and their predators were collected from a variety of aquatic habitats (rice fields, ponds, wetlands, shrimp ponds, ditches, canals, and rivers). We collected 936 Culex spp. (354 Cx. tritaeniorhynchus, 240 Cx. vishnui s.l., 189 Cx. fuscocephala, and 42 Cx. gelidus), 33 Uranotaenia, 25 Anopheles, and 9 Mimomyia (4 Mi. chamberlaini) in the dry season. During the rainy season, we collected 1,232 Culex spp. (132 Cx. vishnui s.l., 66 Cx. tritaeniorhynchus, 9 Cx. gelidus, 4 Cx. fuscocephala, and 2 Cx. bitaeniorhynchus), 236 Anopheles spp. (40 An. vagus and 1 An. sinensis), and 7 Uranotaenia (3 Ur. lateralis). Heteroptera such as Micronecta, Veliidae, and Pleidae were abundant and widely distributed in both seasons. Based on a stepwise generalized linear model, the abundance of mosquitoes and their predators in rice fields was high when the rice plant length was short and water depth was shallow. Therefore, the use of insecticides during the earlier stages of rice growth should be avoided in order to preserve the predator populations.

  13. Gender relations and sexual communication among female students in the Mekong River Delta of Vietnam.

    Science.gov (United States)

    Bui, Thanh Cong; Diamond, Pamela M; Markham, Christine; Ross, Michael W; Nguyen-Le, Thanh-An; Tran, Ly Hai Thi

    2010-08-01

    Young women's ability to pursue a safer-sex life in line with their wishes is crucial to their sexual health. Although some previous observations have suggested that young women's lack of ability to negotiate safer sex is due to gender power imbalances in the culture of Vietnam, studies that have tested this hypothesis explicitly and quantitatively are few and far between. The present study aimed to test the association between perceived gender relations and perceived self-efficacy in communicating sexual matters among undergraduate female students in the Mekong River Delta of Vietnam. The analysis involved secondary data from 260 subjects from a larger survey regarding gender equity. Structural equation modeling was used to examine the study's hypothesis. Results showed that adherence to traditional gender roles and norms was significantly associated with female students' reduced self-efficacy to communicate on safer-sex matters, such as refusing unwanted sex or requesting condom use. This association remained invariant in the cross-validation process between partnered and unpartnered groups. Programmes that aim to promote safer-sex negotiation and practices for this population may need to address the influence of gender relations and power.

  14. Clonal occurrence of Salmonella Weltevreden in cultured shrimp in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Uddin, Gazi Md Noor; Larsen, Marianne Halberg; Barco, Lisa

    2015-01-01

    This study investigated the occurrence, serovar and antimicrobial resistance of Salmonella spp. in shrimp samples from intensive and extensive farms located in three different provinces in the Mekong Delta, Vietnam. Shrimp from 11 of the 48 farms all contained S. Weltevreden, except for one farm...... yielding S. Agona, with no difference in Salmonella occurrence between the two production systems. Pulsed field gel electrophoresis (PFGE) of S. Weltevreden showed closely related XbaI pulse types, suggesting a clonal relationship despite the farms and shrimp samples being epidemiologically unrelated. S....... Weltevreden was susceptible to most antimicrobials tested, with a few strains being resistant to florfenicol, chloramphenicol, sulfamethoxazole or trimethoprim. Future studies of the ecology of S. Weltevreden should establish if this serovar may survive better and even multiply in warm-water shrimp farm...

  15. Clonal Occurrence of Salmonella Weltevreden in Cultured Shrimp in the Mekong Delta, Vietnam.

    Directory of Open Access Journals (Sweden)

    Gazi Md Noor Uddin

    Full Text Available This study investigated the occurrence, serovar and antimicrobial resistance of Salmonella spp. in shrimp samples from intensive and extensive farms located in three different provinces in the Mekong Delta, Vietnam. Shrimp from 11 of the 48 farms all contained S. Weltevreden, except for one farm yielding S. Agona, with no difference in Salmonella occurrence between the two production systems. Pulsed field gel electrophoresis (PFGE of S. Weltevreden showed closely related XbaI pulse types, suggesting a clonal relationship despite the farms and shrimp samples being epidemiologically unrelated. S. Weltevreden was susceptible to most antimicrobials tested, with a few strains being resistant to florfenicol, chloramphenicol, sulfamethoxazole or trimethoprim. Future studies of the ecology of S. Weltevreden should establish if this serovar may survive better and even multiply in warm-water shrimp farm environments compared to other Salmonella serovars.

  16. Exploring the climate change concerns of striped catfish producers in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, Anh Lam; Truong, Minh Hoang; Verreth, Johan Aj; Leemans, Rik; Bosma, Roel H; De Silva, Sena S

    2015-01-01

    This study investigated the perceptions on and adaptations to climate change impacts of 235 pangasius farmers in the Mekong Delta, Vietnam. Data were collected using semi-structured household surveys in six provinces, from three regions along the Mekong river branches. A Chi-Square test was used to determine the association between variables, and a logit regression model was employed to identify factors correlated with farmer's perception and adaptation. Less than half of respondents were concerned about climate change and sought suitable adaptation measures to alleviate its impacts. Improving information on climate change and introducing early warning systems could improve the adaptive capacity of pangasius farmers, in particularly for those farmers, who were not concerned yet. Farmers relied strongly on technical support from government agencies, but farmers in the coastal provinces did not express the need for training by these institutions. This contrasting result requires further assessment of the effectiveness of adaptation measures such as breeding salinity tolerant pangasius.

  17. Temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of Vietnam.

    Directory of Open Access Journals (Sweden)

    Kathryn E Holt

    Full Text Available BACKGROUND: typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi, which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina assay to type 1,500 single nucleotide polymorphisms (SNPs and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005. PRINCIPAL FINDINGS: the population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Sông H u branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene. SIGNIFICANCE: the H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2 observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam.

  18. Vietnam.

    Science.gov (United States)

    1984-05-01

    Attention in this discussion of Vietnam is directed to the following: people; geography; history; government; the economy (agriculture and industry, trade and balance of payments); foreign relations; and relations between the US and Vietnam. In mid-1983 the population was estimated at 57,610,000 with an annual growth rate of 2.4%. Ethnic Vietnamese constitute almost 90% of the population. Various ethnic groups make up the remaining 10% of the population, with approximately 1.2 million Chinese being the most numerous and concentrated in southern Vietnam. The 2nd largest minority, the Montagnards (mountain tribesmen) comprise 2 main ethnolinguistic groups--Malayo Polynesia and Mon-Khmer. The most important political institution in Vietnam is the Vietnamese Communisty Party. All but 4 party Politburo members concurrently hold high positions in the government. The most important powers within the Vietnamese government, as opposed to the Communisty Party, are the executive agencies. Under the overly ambitious initial 5 year plan and the more conservative 1981-85 plan, the Vietnamese have made little progress in raising output and living standards beyond the levels of the 1960s. Guidelines of the 1981-85 plan call for attaining food self sufficiency, strengthening export and consumer industries, as well as the heavy industries that support them, and improving transport and energy production. The US does not have diplomatic relations with Vietnam.

  19. Perceptions of water, sanitation and health: a case study from the Mekong Delta, Vietnam.

    Science.gov (United States)

    Herbst, S; Benedikter, S; Koester, U; Phan, N; Berger, C; Rechenburg, A; Kistemann, T

    2009-01-01

    In the Mekong Delta in the south of Vietnam about 5.7 million people lack access to safe drinking water and 10 million people in rural areas live without adequate sanitation. Between May and August, 2007 a survey was carried out in An Bin, a peri-urban ward in the Mekong Delta, to gain insight into water, sanitation and health as well as to health-related hygiene behaviour. The study employed a combination of quantitative (standardized questionnaire) and qualitative (focus group discussions, semi-structured interviews) methods. The most important features in the choice of drinking water sources are matters of hygiene and the taste of the water. The majority (74%) of the 120 households surveyed indicated their ownership of a sanitation facility, but the fish pond toilet (64%) which is predominantly utilized is considered to be unimproved sanitation. The local peri-urban population link water and hygiene to health, but sanitation instead to environmental pollution. This and other outcomes lead to the assumption that people have a basic knowledge of proper hygiene behaviour. However, hygiene measures such as hand washing are put into practice in an untimely manner, most likely due to a misconception of risks and/or a lack of background knowledge of cause-effect relationships as well as ingrained habits.

  20. Trace Gas Emissions from Extensive Aquaculture Systems in the Red River Delta, Vietnam

    Science.gov (United States)

    Beman, J.; Seto, K. C.

    2002-12-01

    The Red River Delta of Vietnam is an area undergoing rapid land use change. Aquaculture development is among the most significant of these transformations, with important economic, social and environmental effects. We explored the potential for managed mangrove' and `converted paddy' aquaculture systems in the Delta to produce and/or consume greenhouse gasses. We measured dissolved concentrations of the radiatively-important trace gasses methane (CH4) and nitrous oxide (N2O), as well as associated parameters. All ponds were super-saturated with CH4, with concentrations ranging from 132-1203 nM, (mean 561 nM) in managed mangrove, and 28-521 nM (mean 110 nM) in converted paddy. Surprisingly, none of the ponds was measurably supersaturated with N2O. Methane fluxes were calculated for all ponds using five well-accepted models of gas flux based on wind speed. Mean flux values ranged from 1.04 to 17.09 mg CH4 m-2 d-1 for managed mangrove, falling somewhere between fluxes reported for natural systems and those receiving sewage inputs. Further measurements should be made in more intensive systems to better understand the potential for trace gas production-particularly N2O-in aquaculture systems.

  1. Bottom sediments affect Sonneratia mangrove forests in the prograding Mekong delta, Vietnam

    Science.gov (United States)

    Nardin, William; Woodcock, Curtis E.; Fagherazzi, Sergio

    2016-08-01

    Mangrove forests exert a strong influence on tropical deltas by trapping sediments discharged by rivers and by stabilizing the substrate with roots. Understanding the dynamics of sediments and morphology in and around mangrove forests is critical in order to assess the resilience of coastlines in a period of accelerated sea level rise. In this research, sediment samples, mangrove forest characteristics, and remote sensing data are used to investigate the relationship between mangroves and sediment substrate in the Mekong Delta, Vietnam. Our data show a significant correlation between percent of sand in bottom sediments and density of Sonneratia caseolaris forest. We ascribe this result to higher sediment disturbance in muddy areas that prevents seedling establishment. This correlation potentially allows the determination of substrate characteristics from vegetation attributes detected by remote sensing, despite the impenetrability of the forest canopy. The results presented herein suggest that a supply of sand from the river and hydrodynamic processes moving the sand ashore control the density of the Sonneratia mangrove forests at this location, promoting tidal flat colonization and canopy expansion.

  2. Antimicrobial usage in chicken production in the Mekong Delta of Vietnam.

    Science.gov (United States)

    Carrique-Mas, Juan J; Trung, Nguyen V; Hoa, Ngo T; Mai, Ho Huynh; Thanh, Tuyen H; Campbell, James I; Wagenaar, Jaap A; Hardon, Anita; Hieu, Thai Quoc; Schultsz, Constance

    2015-04-01

    Antimicrobials are used extensively in chicken production in Vietnam, but to date no quantitative data are available. A 2012-2013 survey of 208 chicken farms in Tien Giang province, stratified by size (10-200 chickens; >200-2000), was carried out to describe and quantify the use of antibacterial antimicrobials (usage per week per chicken and usage per 1000 chickens produced) in the Mekong Delta and to investigate factors associated with usage. Twenty-eight types of antimicrobial belonging to 10 classes were reported. Sixty-three per cent of all commercial formulations contained at least two antimicrobials. On 84% occasions, antimicrobials were administered with a prophylactic purpose. The overall adjusted quantities of antimicrobials used/week/chicken and per 1000 chickens produced (g) were 26.36 mg (SE ± 3.54) and 690.4 g (SE ± 203.6), respectively. Polypeptides, tetracyclines, penicillins and aminoglycosides were the antimicrobials used by most farms (18.6% farms, 17.5%, 11.3% and 10.1% farms, respectively), whereas penicillins, lincosamides, quinolones, and sulphonamides/trimethoprim were quantitatively the most used compounds (8.27, 5.2, 3.16 and 2.78 mg per week per chicken, respectively). Factors statistically associated with higher levels of usage (per week per chicken) were meat farms (OR = 1.40) and farms run by a male farmer (OR = 2.0). All-in-all-out farming systems (correlated with medium farms) were associated with reduced levels of antimicrobial usage (OR = 0.68). Usage levels to produced meat chickens were considerably higher than those reported in European countries. This should trigger the implementation of surveillance programmes to monitor sales of antimicrobials that should contribute to the rational administration of antimicrobials in order to preserve the efficacy of existing antimicrobials in Vietnam.

  3. Copper use and accumulation in catfish culture in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Marcussen, Helle; Løjmand, Helle; Dalsgaard, Anders; Hai, Dao M; Holm, Peter E

    2014-01-01

    Aquaculture of Pangasius hypophthalmus (striped catfish) in Vietnam reached 1.1 million tonnes in 2011 and catfish fillets are exported worldwide. The intensive cultures of catfish mainly in earth ponds have made it necessary to apply CuSO4 and other chemicals to control external parasites and other pathogens. However, accumulation of Cu in aquaculture ponds may pose a hazard to growth of fish or to the aquatic environment. The aim of this study was to determine accumulation of Cu in sediment, water and fish in a catfish pond with a history of repeated treatment with CuSO4 in the Mekong Delta, Vietnam. Copper concentrations in pond sediment were in the interval 21.3-45.7 mg kg(-1) dw and did not exceed the Vietnamese values for soil to be used for agricultural production (70 mg kg(-1) dw.). During three samplings the total mean concentration of Cu in pond water (4 μg L(-1)) did not exceed the LC50-value (70 μg L(-1)) for catfish and the mean dissolved concentration of Cu (0.986 μg L(-1)) did not seem to constitute a risk for the stability of the aquatic ecosystem. No significant variation in Cu concentrations between sampling sites in the pond and depth of sediment profile were determined. The accumulation of Cu in catfish was highest in the liver compared to the skin, gills and muscle tissue. With the current practice of removing pond sludge three to four times during a production cycle little if any Cu seems to accumulate in catfish ponds despite repeated anti-parasite treatments with CuSO4. Further studies are needed to assess the eco-toxicity and impact on agricultural production when pond sediment is discharged into aquatic recipients and used as soil fertilizer.

  4. Piped-Water Supplies in Rural Areas of the Mekong Delta, Vietnam: Water Quality and Household Perceptions

    OpenAIRE

    Gert-Jan Wilbers; Zita Sebesvari; Renaud, Fabrice G.

    2014-01-01

    In the Mekong Delta (MD) in Vietnam, piped-water supply stations are being intensively built to reach the millennium development goal (MDG) to provide safe and clean drinking water resources to communities. However, studies focusing on the effectiveness of supply stations in reaching these goals are scarce to date. Water samples from 41 water supply stations in the MD were collected between June and October 2012. Water samples were analyzed for general parameters, salinity, nutrients, metal(l...

  5. The influence of changes in the market environment on economic production characteristics of Pangasius farming in the Mekong Delta (Vietnam)

    OpenAIRE

    Tu, V.B.; D'Haese, M.; Speelman, S.; D'Haese, L.

    2010-01-01

    The Mekong Delta in Vietnam has become an important production area for pangasius. The importance of the sector in providing an income to many households means that it is relevant to study its economic production characteristics. In this article we use a stochastic cost frontier model to assess the adaptability of the sector. We are particularly interested in the effect of the changing market environment and the exponential growth of the sector on the evolution of production characteristics. ...

  6. Greenhouse gas emissions of different land uses in the delta region of Red River, Vietnam

    Science.gov (United States)

    Zhou, Minghua; Ha, Thu; An, Ngo The; Brüggemann, Nicolas

    2017-04-01

    Agricultural activities are responsible for up to a third of total anthropogenic GHG emissions. The subtropical/tropical delta areas of the large rivers in Southeast Asia are long-term history agricultural regions in the world. However, due to lack of field measurements, the estimation of the contribution of agro-ecosystems in the subtropical/tropical delta areas to global greenhouse gas emissions remains largely uncertain. Here, we conducted field experiments since January 2016 to quantify greenhouse gases (CO2, CH4 and N2O) emissions from four agricultural land uses of annual rice-rice, rice-vegetable, continuous vegetable system and fish pond in Red River delta region of Vietnam by using the transparent static chamber-gas chromatography technique. Higher N2O emissions were observed in the rice-vegetable and continuous vegetable systems, while lower N2O emissions were observed in the rice-rice and find pond systems. Compared to rice-rice system the cumulative N2O fluxes were on average twenty-fold higher in the rice-vegetable and continuous vegetable systems but significantly lower (75%) in the fish pond. Overall the net CO2 sinks were observed in the rice-rice system while other three land uses of rice-vegetable, continuous vegetable and fish pond acted as the net CO2 sources. The rice-rice and fish pond showed net CH4 emissions while variations of CH4 emissions (i.e. shifting between sources and sinks) along variations of soil moisture and temperature were observed in rice-vegetable and continuous vegetable systems. Compared to rice-rice system, the cumulative CH4 fluxes were significantly decreased by 100% for continuous vegetable system, 94% for rice-vegetable system and 89% for fish pond. Overall, the data suggest that conversion of traditional rice-rice paddy system to rice-vegetable, continuous vegetable system and find pond, which are currently undergoing driven by the economical requests and environmental changes (e.g., salinity intrusion) in this delta

  7. Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam.

    Directory of Open Access Journals (Sweden)

    Chau Nguyen Dang Giang

    Full Text Available The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX, 4 ng L-1 sulfadiazine (SDZ, 17 ng L-1 trimethoprim (TRIM, and 12 ng L-1 enrofloxacin (ENRO. These concentrations were lower than the predicted no effect concentrations (PNECs and minimum inhibitory concentrations (MICs, suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from <1 to 44 days, depending on the availability of sunlight and sediment. Among the studied antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks

  8. Application of the Water Needs Index: Can Tho City, Mekong Delta, Vietnam

    Science.gov (United States)

    Moglia, Magnus; Neumann, Luis E.; Alexander, Kim S.; Nguyen, Minh N.; Sharma, Ashok K.; Cook, Stephen; Trung, Nguyen H.; Tuan, Dinh D. A.

    2012-10-01

    SummaryProvision of urban water supplies to rapidly growing cities of South East Asia is difficult because of increasing demand for limited water supplies, periodic droughts, and depletion and contamination of surface and groundwater. In such adverse environments, effective policy and planning processes are required to secure adequate water supplies. Developing a Water Needs Index reveals key elements of the complex urban water supply by means of a participatory approach for rapid and interdisciplinary assessment. The index uses deliberative interactions with stakeholders to create opportunities for mutual understanding, confirmation of constructs and capacity building of all involved. In Can Tho City, located at the heart of the Mekong delta in Vietnam, a Water Needs Index has been developed with local stakeholders. The functional attributes of the Water Needs Index at this urban scale have been critically appraised. Systemic water issues, supply problems, health issues and inadequate, poorly functioning infrastructure requiring attention from local authorities have been identified. Entrenched social and economic inequities in access to water and sanitation, as well as polluting environmental management practices has caused widespread problems for urban populations. The framework provides a common language based on systems thinking, increased cross-sectoral communication, as well as increased recognition of problem issues; this ought to lead to improved urban water management. Importantly, the case study shows that the approach can help to overcome biases of local planners based on their limited experience (information black spots), to allow them to address problems experienced in all areas of the city.

  9. Early growth stage of a large delta — Transformation from estuarine-platform to deltaic-progradational conditions (the northeastern Mekong River Delta, Vietnam)

    Science.gov (United States)

    Hanebuth, Till J. J.; Proske, Ulrike; Saito, Yoshiki; Nguyen, Van Lap; Ta, Thi Kim Oanh

    2012-06-01

    The initial growth stage of a river delta can be defined either as the beginning geomorphologic expansion of the river-dominated coastal lowland or as the starting basinward-directed progradation of the geological/stratigraphic delta body. Differentiating between these two perspectives is necessary for understanding the sensitive reaction of a deltaic system to dynamic changes in sea-level and sediment availability. The Holocene evolution of the northeastern part of the Mekong River delta (Southern Vietnam) offers a great chance to depict these two different definitions and relate them genetically to each other since the transition between an old abrasion platform (inner delta) and the continental-shelf basin (outer delta) is well developed in this marginal part of the delta. The early stage of delta growth taking place during transgression-related inundation between 8 cal ka BP (maximum flooding) and 5.7 (6.0-4.8) cal ka BP (sea-level highstand) was characterized by tide-and saltwater-influenced nearshore conditions allowing extensive mangrove and tidal-flat deposits to aggradate on the wide abrasion platform. With the onset of regression around 4.8 cal ka BP the depositional center shifted immediately beyond the seaward margin of this estuarine platform and thus true deltaic progradation could develop leading to rapid construction of a delta body (and, in addition, to subsidence/tilting of the inner delta zone). Directly at the transition of these two deposystems, remains of shore-related deposits indicate the sudden breakdown of the estuarine platform conditions around 4.6 cal ka BP.

  10. Intraspecific diversity of Edwardsiella ictaluri isolates from diseased freshwater catfish, Pangasianodon hypophthalmus (Sauvage), cultured in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Bartie, K L; Austin, F W; Diab, A; Dickson, C; Dung, T T; Giacomini, M; Crumlish, M

    2012-09-01

    A molecular epidemiology study was conducted on 90 Edwardsiella ictaluri isolates recovered from diseased farmed freshwater catfish, Pangasianodon hypophthalmus, cultured in the Mekong Delta, Vietnam. Thirteen isolates of E. ictaluri derived from diseased channel catfish, Ictalurus punctatus, cultured in the USA were included for comparison. All the E.ictaluri isolates tested were found to be biochemically indistinguishable. A repetitive (rep)-PCR using the single (GTG)(5) primer was shown to possess limited discriminatory power, yielding two similar DNA profiles categorized as (GTG)(5) -PCR group 1 or 2 among the Vietnam isolates and (GTG)(5) -PCR group 1 within the USA isolates. Macrorestriction analysis identified 14 and 22 unique pulsotypes by XbaI and SpeI, respectively, among a subset of 59 E. ictaluri isolates. Numerical analysis of the combined macrorestriction profiles revealed three main groups: a distinct cluster formed exclusively of the USA isolates, and a major and minor cluster with outliers contained the Vietnam isolates. Antibiotic susceptibility and plasmid profiling supported the existence of the three groups. The results indicate that macrorestriction analysis may be regarded as a suitable typing method among the E. ictaluri species of limited intraspecific diversity. Furthermore, the findings suggest that E. ictaluri originating from Vietnam may constitute a distinct genetic group.

  11. Pesticide pollution of multiple drinking water sources in the Mekong Delta, Vietnam: evidence from two provinces.

    Science.gov (United States)

    Chau, N D G; Sebesvari, Z; Amelung, W; Renaud, F G

    2015-06-01

    Pollution of drinking water sources with agrochemicals is often a major threat to human and ecosystem health in some river deltas, where agricultural production must meet the requirements of national food security or export aspirations. This study was performed to survey the use of different drinking water sources and their pollution with pesticides in order to inform on potential exposure sources to pesticides in rural areas of the Mekong River delta, Vietnam. The field work comprised both household surveys and monitoring of 15 frequently used pesticide active ingredients in different water sources used for drinking (surface water, groundwater, water at public pumping stations, surface water chemically treated at household level, harvested rainwater, and bottled water). Our research also considered the surrounding land use systems as well as the cropping seasons. Improper pesticide storage and waste disposal as well as inadequate personal protection during pesticide handling and application were widespread amongst the interviewed households, with little overall risk awareness for human and environmental health. The results show that despite the local differences in the amount and frequency of pesticides applied, pesticide pollution was ubiquitous. Isoprothiolane (max. concentration 8.49 μg L(-1)), fenobucarb (max. 2.32 μg L(-1)), and fipronil (max. 0.41 μg L(-1)) were detected in almost all analyzed water samples (98 % of all surface samples contained isoprothiolane, for instance). Other pesticides quantified comprised butachlor, pretilachlor, propiconazole, hexaconazole, difenoconazole, cypermethrin, fenoxapro-p-ethyl, tebuconazole, trifloxystrobin, azoxystrobin, quinalphos, and thiamethoxam. Among the studied water sources, concentrations were highest in canal waters. Pesticide concentrations varied with cropping season but did not diminish through the year. Even in harvested rainwater or purchased bottled water, up to 12 different pesticides were detected at

  12. Bartonella species and trombiculid mites of rats from the Mekong Delta of Vietnam.

    Science.gov (United States)

    Loan, Hoang Kim; Cuong, Nguyen Van; Takhampunya, Ratree; Klangthong, Kewalin; Osikowicz, Lynn; Kiet, Bach Tuan; Campbell, James; Bryant, Juliet; Promstaporn, Sommai; Kosoy, Michael; Hoang, Nguyen Van; Morand, Serge; Chaval, Yannick; Hien, Vo Be; Carrique-Mas, Juan

    2015-01-01

    A survey of Bartonella spp. from 275 rats purchased in food markets (n=150) and trapped in different ecosystems (rice field, forest, and animal farms) (n=125) was carried out during October, 2012-March, 2013, in the Mekong Delta of Vietnam. The overall Bartonella spp. prevalence detected by culture and PCR in blood was 14.9% (10.7-19.1%), the highest corresponding to Rattus tanezumi (49.2%), followed by Rattus norvegicus (20.7%). Trapped rats were also investigated for the presence and type of chiggers (larvae of trombiculid mites), and Bartonella spp. were investigated on chigger pools collected from each rat by RT-PCR. A total of five Bartonella spp. were identified in rats, three of which (B. elizabethae, B. rattimassiliensis, and B. tribocorum) are known zoonotic pathogens. Among trapped rats, factors independently associated with increased prevalence of Bartonella spp. included: (1) Rat species (R. tanezumi); (2) the number of Trombiculini-Blankaartia and Schoengastiini-Ascoschoengastia mites found on rats; and (3) the habitat of the rat (i.e., forest/fields vs. animal farms). The prevalence of Bartonella infection among chiggers from Bartonella spp.-positive R. tanezumi rats was 5/25 (25%), compared with 1/27 (3.7%) among Bartonella spp.-negative R. tanezumi rats (relative risk [RR]=5.4, 95% confidence interval [CI] 0.68-43.09). The finding of Bartonella spp.-positive chiggers on Bartonella spp.-negative rats is strongly suggestive of a transovarial transmission cycle. Rats are ubiquitous in areas of human activity and farms in the Mekong Delta; in addition, trapping and trading of rats for food is common. To correctly assess the human risks due to rat trapping, marketing, and carcass dressing, further studies are needed to establish the routes of transmission and cycle of infection. The widespread presence of these zoonotic pathogens in rats and the abundance of human-rat interactions suggest that surveillance efforts should be enhanced to detect any human

  13. Impact of the Hoa Binh Dam (Vietnam on water and sediment budgets in the Red River basin and delta

    Directory of Open Access Journals (Sweden)

    D. V. Vu

    2014-01-01

    Full Text Available The Hoa Binh Dam, located on a tributary of the Red River in Vietnam, has a capacity of 9.45 × 109 m3 and was commissioned in December 1988. Although being important for flood prevention, electricity production, and irrigation in northern Vietnam, the Hoa Binh Dam has also highly influenced the suspended sediment distribution in the lower Red River basin, in the delta and in the coastal zone. Its impact was analysed from 50 yr dataset of water discharge and suspended sediment concentration (1960–2010 and the distribution of water and sediment across the nine mouths of the delta was calculated using the MIKE 11 numerical model before and after the dam settlement. Although water discharge at the delta inlet decreased by only 8.8%, the yearly suspended sediment flux dropped, on average from 119 to 43 × 106 t yr−1 at Son Tay near Hanoi, and from 85 to 35 × 106 t yr−1 in the river mouths. Water regulation has led to decreased water discharge in the wet season and increased water discharge in the dry season. Suspended sediment discharge proportionally increased in northern and southern estuaries and decreased through the main and central Ba Lat mouth. Tidal pumping, which causes a net sediment flux from the coast to the estuary at low discharge, is high in the northern delta, as a consequence of the high tidal range (up to 4.5 m in spring tide; diurnal tide. The shifts in the dynamic and characteristics of the turbidity maximum zone in the Cam-Bach Dang estuary are probably the cause of the enhanced sediment deposition in the Haiphong harbor. Along the coast, the reduced sedimentation rates are coincident with the lower sediment delivery that has been observed since the impoundment of the Hoa Binh Dam.

  14. Governance of ‘long term delta planning’ in Bangladesh, Vietnam and the Netherlands

    NARCIS (Netherlands)

    Staveren, van M.F.

    2014-01-01

    The Deltas in Times of Climate Change Conference II, taking place in September 2014, Rotterdam, presented a suitable occasion to discuss both delta challenges and interesting approaches to how ‘delta dynamics’ are being dealt with worldwide.1 Delta dynamics include here both environmental (including

  15. An evaluation of fish health-management practices and occupational health hazards associated with Pangasius catfish (Pangasianodon hypophthalmus) aquaculture in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Phu, Tran Minh; Phuong, Nguyen Thanh; Dung, Tu Thanh; Hai, Dao Minh; Son, Vo Nam; Rico Artero, Andreu; Clausen, Jesper Hedegaard; Madsen, Henry; Murray, Francis; Dalsgaard, Anders

    2016-01-01

    This study aimed to evaluate the current status on the use of probiotics, disinfectants and antimicrobials in hatcheries, nurseries and grow-out farms producing Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. Semi-structured interviews were conducted with 83 aquacult

  16. An evaluation of fish health-management practices and occupational health hazards associated with Pangasius catfish (Pangasianodon hypophthalmus) aquaculture in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Phu, TranMinh; Nguyen Thanh, Phuong; Dung, Tu Thanh

    2016-01-01

    This study aimed to evaluate the current status on the use of probiotics, disinfectants and antimicrobials in hatcheries, nurseries and grow-out farms producing Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. Semi-structured interviews were conducted with 83...

  17. Impact of the Hoa Binh dam (Vietnam) on water and sediment budgets in the Red River basin and delta

    Science.gov (United States)

    Vinh, V. D.; Ouillon, S.; Thanh, T. D.; Chu, L. V.

    2014-10-01

    The Hoa Binh dam (HBD), located on a tributary of the Red River in Vietnam, has a capacity of 9.45 × 109 m3 and was commissioned in December 1988. Although it is important for flood prevention, electricity production and irrigation in northern Vietnam, the Hoa Binh dam has also highly influenced the suspended sediment distribution in the lower Red River basin, in the delta and in the coastal zone. Its impact was analysed from a 50-year data set of water discharge and suspended sediment concentration (1960-2010), and the distribution of water and sediment across the nine mouths of the delta was simulated using the MIKE11 numerical model before and after the dam settlement. Although water discharge at the delta inlet decreased by only 9%, the yearly suspended sediment flux dropped, on average, by 61% at Son Tay near Hanoi (from 119 to 46 × 106 t yr-1). Along the coast, reduced sedimentation rates are coincident with the lower sediment delivery observed since the impoundment of the Hoa Binh dam. Water regulation has led to decreased water discharge in the wet season (-14% in the Red River at Son Tay) and increased water discharge in the dry season (+12% at the same station). The ratios of water and suspended sediment flows, as compared to the total flows in the nine mouths, increased in the northern and southern estuaries and decreased in the central, main Ba Lat mouth. The increasing volume of dredged sediments in the Haiphong harbour is evidence of the silting up of the northern estuary of Cam-Bach Dang. The effect of tidal pumping on enhanced flow occurring in the dry season and resulting from changed water regulation is discussed as a possible cause of the enhanced siltation of the estuary after Hoa Binh dam impoundment.

  18. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam

    Science.gov (United States)

    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwate...

  19. Agricultural Innovation - Multiple grounds for technology policies in the Red River Delta of Vietnam

    NARCIS (Netherlands)

    Nguyen Van Linh,

    2001-01-01

    Food security, a lingering concern although is not as critical as in the past, remains one of the most important strategies for agricultural development in Vietnam. In conjunction with this strategy, productivity is very much a concern of the government. However, growth in agricultural productivity

  20. Amorphophallus kienluongensis (Araceae), a new species from the Mekong Delta, Southern Vietnam

    NARCIS (Netherlands)

    Nguyen, V.D.; Luu, H.T.; Nguyen, Q.D.; Hetterscheid, W.L.A.

    2016-01-01

    Amorphophallus kienluongensis is described as a new species from southern Vietnam. It is morphologically close to A. brevispathus Gagnep. (Thailand) and A. prolificus Hett. & A.Galloway (Thailand). However, it differs from both these species by a stigma with a central depression and an obconic male

  1. Agricultural innovation : multiple grounds for technology policies in the Red River Delta of Vietnam

    NARCIS (Netherlands)

    Nguyen Van Linh,

    2001-01-01

    Food security, a lingering concern although is not as critical as in the past, remains one of the most important strategies for agricultural development in Vietnam. In conjunction with this strategy, productivity is very much a concern of the government. However, growth in agricultural

  2. Spatial modelling for nitrogen leaching from intensive farming in Red River Delta of Vietnam

    NARCIS (Netherlands)

    Mai, V.T.; Hoanh, C.T.; Keulen, van H.; Hessel, R.

    2013-01-01

    In this study, a spatial dynamic model was developed, to simulate nitrogen dynamics in Van Hoi commune, Tam Duong district, Vietnam, for different soil and land use types, under different irrigation and fertilizer regimes. The model has been calibrated using measured nitrogen concentrations in soil

  3. Resilience and livelihood dynamics of shrimp farmers and fishers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Phung, H.

    2012-01-01

    Shrimp aquaculture and fishery, the two important economic sectors in Vietnam, have been promoted by the government to reduce poverty, provide job opportunities, and to increase exports to support economic development. However, this expansion of fishery and aquaculture has also had negative effects.

  4. Developing an Integrated Pest Management Program for Tomatoes in The Red River Delta of Vietnam: A mini review

    Directory of Open Access Journals (Sweden)

    Tuan M. Ha

    2015-08-01

    Full Text Available Ecologically based approaches to pest management in crop production have been embraced in recent decades due to their validity and effectiveness. Integrated Pest Management (IPM is not a new concept. It has been adopted in various regions in Vietnam, particularly in tomato production, an economically important vegetable crop in the Red River Delta (RRD. Given the occurrence and development of tomato pests are influenced by many factors such as soil types, crop varieties and growth habits, production practices, local climatic conditions, and growing seasons, this paper therefore developed an IPM program for tomatoes in the RRD based on the defined major pests in the region. Detailed factsheets for six major pests were developed and different components of the IPM were explored and employed for the ease of identification and management. Practical suggestions for tomato growers were also presented.

  5. Prevalence of risk factors for non-communicable diseases in the Mekong Delta, Vietnam: results from a STEPS survey

    Directory of Open Access Journals (Sweden)

    Pham Luc H

    2009-08-01

    Full Text Available Abstract Background Despite the increasing burden of non-communicable diseases (NCD in Vietnam, information on the prevalence of preventable risk factors for NCD is restricted to the main urban centres of Ha Noi, and Ho Chi Minh City (HCMC. This population-based survey aimed to describe the prevalence of risk factors for NCD in a rural Vietnamese sample. Methods This survey was conducted using the WHO "STEPwise approach to surveillance of non-communicable diseases" (STEPS methodology. Participants (n = 1978 were residents of the Mekong Delta region selected by multi-stage sampling. Standardised international protocols were used to measure behavioural risk factors (smoking, alcohol consumption, fruit and vegetable consumption, physical activity, physical characteristics (weight, height, waist and hip circumferences, blood pressure – BP, fasting blood glucose (BG and total cholesterol (TC. Data were analysed using complex survey analysis methods. Results In this sample, 8.8% of men and 12.6% of women were overweight (body mass index (BMI ≥ 25 kg/m2 and 2.3% of men and 1.5% of women were obese (BMI ≥ 30 kg/m2. The prevalence of hypertension (systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg, or taking medication for hypertension was 27.3% for men and 16.2% for women. There were 1.0% of men and 1.1% of women with raised BG (defined as capillary whole BG of at least 6.1 mmol/L. Conclusion We provide the first NCD risk factor profile of people living in the Mekong Delta of Vietnam using standardised methodology. Our findings for this predominantly rural sample differ from previous studies conducted in Ha Noi and HCMC, and suggest that it is inappropriate to generalise findings from the big-city surveys to the other 80% of the population.

  6. Discrimination rice cropping systems using multi-temporal Proba-V data in the Mekong Delta, Vietnam

    Science.gov (United States)

    Son, Nguyen-Thanh; Chen, Chi-Farn; Chen, Cheng-Ru; Chang, Ly-Yu; Chiang, Shou-Hao; Lau, Khin-Va

    2016-04-01

    Rice is considered a main source of livelihoods for several billions of people worldwide and plays an important role in the economy of many Asian countries. More than just a food source, rice production is regarded as one of the most important components to maintaining political stability and is also a national subject of economic policy due to domestic food consumption and grain exports. Vietnam is globally one of the largest rice producers and suppliers with more than 80% of the exported rice amount produced from the Mekong River Delta. This delta is one of the three deltas in the world most vulnerable to the climate change, causing the potential loss of rice yields. Thus, spatiotemporal information of rice cropping systems is important for agricultural management to ensure food security and rice grain exports. Coarse resolution satellite data such as MODIS demonstrates the applicability for rice mapping at a large scale. However, the use of MODIS data for such a monitoring purpose still reveals a challenging task due to mixed-pixel issues. The Proba-V satellite launched on 7 May 2013 is a potential candidate for this monitoring purpose because the data include four spectral bands (blue, red, near-infrared and mid-infrared) with a swath of 2,285 km with a spatial resolution of 100 m and temporal resolution of 5 days. This study aimed to investigate the applicability of multi-temporal Proba-V data for mapping rice cropping systems in Mekong Delta River, South Vietnam. The data were processed for 2014-2015 rice cropping seasons, following three main steps: (1) construction of smooth time-series NDVI data, (2) classification of rice cropping systems using crop phenological metrics, and (3) accuracy assessment of the mapping results. The results indicated that the smooth time-series NDVI profiles characterized the temporal spectral responses of rice fields through different growing stages of rice plant, which was critically important for understanding rice crop

  7. Financial Impacts of Priority Swine Diseases to Pig Farmers in Red River and Mekong River Delta, Vietnam.

    Science.gov (United States)

    Pham, H T T; Antoine-Moussiaux, N; Grosbois, V; Moula, N; Truong, B D; Phan, T D; Vu, T D; Trinh, T Q; Vu, C C; Rukkwamsuk, T; Peyre, M

    2017-08-01

    A study was conducted between May 2013 and August 2014 in three provinces of Vietnam to investigate financial impacts of swine diseases in pig holdings in 2010-2013. The aim of the study was to quantify the costs of swine diseases at producer level in order to understand swine disease priority for monitoring at local level. Financial impacts of porcine reproductive and respiratory syndrome (PRRS), foot and mouth disease (FMD), and epidemic diarrhoea were assessed for 162 pig holders in two Red River Delta provinces and in one Mekong River Delta province, using data on pig production and swine disease outbreaks at farms. Losses incurred by swine diseases were estimated, including direct losses due to mortality (100% market value of pig before disease onset) and morbidity (abortion, delay of finishing stage), and indirect losses due to control costs (treatment, improving biosecurity and emergency vaccination) and revenue foregone (lower price in case of emergency selling). Financial impacts of swine diseases were expressed as percentage of gross margin of pig holding. The gross margin varied between pig farming groups (P swine disease priorities to better inform surveillance and control at both national and local level. © 2016 Blackwell Verlag GmbH.

  8. Promotion of biogas plant application in the Mekong Delta of Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Vo Chau Ngan

    2012-06-11

    The study focuses on waste management in the Mekong Delta of Vietnam (MD) through the application of biogas plants to livestock and agricultural waste treatment. As the biggest ''rice bowl'' in the country, the MD produces more than 50% of the national aquaagricultural production, in which livestock sector contributes more than 20% of agricultural growth. The increasing livestock sector, however, has been attributed to the environmental problems, particularly in relation to the free discharge of waste/wastewater into the water open sources in the region. Such the environmental problems have become more serious in the rural areas of the MD where the water from the canal network is used as the main water supply sources to the 60% of local communities. Biogas technology was introduced as an environmentally-friendly treatment for animal and human wastes in the MD in the 1980s. Nonetheless, the number of biogas plants already constructed is considerably limited in comparison to the actual demand on livestock waste treatment in the region. The study, therefore, aims at seeking for possible solutions to promote the widespread application of biogas plants in the MD in order to help improve the sanitary condition of the local communities. In this study, a survey of 110 farmers was conducted in the three provinces of the MD. The farmers included biogas user households, non-biogas user households, and biogas masons. The interviews with the three groups of farmers provided profound and comprehensive information on the actual application and demand of biogas plants in the MD. Accordingly, a large number of the local people have acknowledged the great benefits of biogas application. However, the interviews revealed that there are some impediments to the development of biogas plants in the region such as high investment cost, shortage of input to biogas plants, and limited possibilities of application of by-products from biogas plants. In an attempt to search

  9. Water Supply or ‘Beautiful Latrines’? Microcredit for Rural Water Supply and Sanitation in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Nadine Reis

    2012-01-01

    Full Text Available Around half of the Mekong Delta’s rural population lacks year-round access to clean water. In combination with inadequate hygiene and poor sanitation this creates a high risk of diseases. Microcredit schemes are a popular element in addressing such problems on the global policy level. The present paper analyses the contradictory results of such a microcredit programme for rural water supply and sanitation in the context of the Mekong Delta, Vietnam, through a qualitative study primarily based on semi-structured interviews in rural communes of Can Tho City. We come to the conclusion that the programme has a positive effect regarding the safer disposal of human excreta as well as surface water quality, but a marginal impact on poverty reduction as it only reaches better-off households already having access to clean water. The paper shows how the outcome of rural water supply and sanitation policies are strongly influenced by the local ecological, technological, and social settings, in particular by stakeholders’ interests. The authors challenge the assumption that water supply and sanitation should be integrated into the same policy in all circumstances. ----- Etwa die Hälfte der ländlichen Bevölkerung des Mekong-Deltas hat nicht das ganze Jahr über Zugang zu sauberem Wasser. Zusammen mit unzureichender Hygiene und mangelnder sanitärer Grundversorgung erhöht diese Situation das Krankheitsrisiko. Auf globaler Ebene sind Mikrokreditprogramme eine gefragte Strategie, um diese Probleme zu behandeln. Der vorliegende Artikel analysiert die widersprüchlichen Ergebnisse eines solchen Mikrokreditprogramms für ländliche Wasser- und sanitäre Grundversorgung im Mekong-Delta in Vietnam im Rahmen einer qualitativen Studie, die auf halbstrukturierten Interviews im Raum Can Tho City basiert. Die Studie kommt zu dem Schluss, dass das Programm eine positive Wirkung in Bezug auf die sichere Entsorgung von Fäkalien und die Qualität des Regenwassers

  10. Pesticide management and their residues in sediments and surface and drinking water in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Toan, Pham Van; Sebesvari, Zita; Bläsing, Melanie; Rosendahl, Ingrid; Renaud, Fabrice G

    2013-05-01

    Public concern in Vietnam is increasing with respect to pesticide pollution of the environment and of drinking water resources. While established monitoring programs in the Mekong Delta (MD) focus on the analysis of organochlorines and some organophosphates, the environmental concentrations of more recently used pesticides such as carbamates, pyrethroides, and triazoles are not monitored. In the present study, household level pesticide use and management was therefore surveyed and combined with a one year environmental monitoring program of thirteen relevant pesticides (buprofezin, butachlor, cypermethrin, α-endosulfan, β-endosulfan, endosulfan-sulfate, fenobucarb, fipronil, isoprothiolane, pretilachlor, profenofos, propanil, and propiconazole) in surface water, soil, and sediment samples. The surveys showed that household level pesticide management remains suboptimal in the Mekong Delta. As a consequence, a wide range of pesticide residues were present in water, soil, and sediments throughout the monitoring period. Maximum concentrations recorded were up to 11.24 μg l(-1) in water for isoprothiolane and up to 521 μg kg(-1) dm in sediment for buprofezin. Annual average concentrations ranged up to 3.34 μg l(-1) in water and up to 135 μg kg(-1) dm in sediment, both for isoprothiolane. Occurrence of pesticides in the environment throughout the year and co-occurrence of several pesticides in the samples indicate a considerable chronic exposure of biota and humans to pesticides. This has a high relevance in the delta as water for drinking is often extracted from canals and rivers by rural households (GSO, 2005, and own surveys). The treatment used by the households for preparing surface water prior to consumption (flocculation followed by boiling) is insufficient for the removal of the studied pesticides and boiling can actually increase the concentration of non-volatile pollutants.

  11. Estimation of nitrogen and phosphorus in effluent from the striped catfish farming sector in the Mekong Delta, Vietnam.

    Science.gov (United States)

    De Silva, Sena S; Ingram, Brett A; Nguyen, Phuong T; Bui, Tam M; Gooley, Geoff J; Turchini, Giovanni M

    2010-11-01

    In this study an attempt is made to estimate nitrogen and phosphorus discharged to the environment from the striped catfish (Pangasianodon hypophthalmus) farming sector in the Mekong Delta (8 degrees 33'-10 degrees 55' N, 104 degrees 30'-106 degrees 50' E), South Vietnam. The sector accounted for 687,000 t production in 2007 and 1,094,879 t in 2008, with over 95% of the produce destined for export to over 100 countries. Commercial and farm-made feeds are used in catfish farming, currently the former being more predominant. Nitrogen discharge levels were similar for commercial feeds (median 46.0 kg/t fish) and farm-made feeds (median 46.8 kg/t fish); whilst, phosphorus discharge levels for commercial feeds (median 14.4 kg/t fish) were considerably lower than for farm-made feeds (median 18.4 kg/t fish). Based on the median nutrient discharge levels for commercial feeds, striped catfish production in the Mekong Delta discharged 31,602 t N and 9,893 t P, and 50,364 t N and 15,766 t P in 2007 and 2008, respectively. However, the amount of nutrients returned directly to the Mekong River may be substantially less than this as a significant proportion of the water used for catfish farming as well as the sludge is diverted to other agricultural farming systems. Striped catfish farming in the Mekong Delta compared favourably with other cultured species, irrespective of the type of feed used, when the total amounts of N and P discharged in the production of a tonne of production was estimated.

  12. Pesticides in soil and sediment of a dyke-protected area of the Red River Delta, Vietnam

    Science.gov (United States)

    Braun, Gianna; Bläsing, Melanie; Kruse, Jens; Amelung, Wulf; Renaud, Fabrice; Sebesvari, Zita

    2017-04-01

    Coastal regions are densely populated but at the same time represent important agricultural areas for food production of the growing world population. To sustain high agricultural yields, in monocultures such as permanent rice systems, pesticides are used in high quantity and frequency. While earlier studies monitored the fate of pesticides in paddy rice systems, the overall fate of these compounds is altered nowadays due to the construction of dykes, which are needed in many delta regions to protect them from high tides, storm surges and salt water intrusion such as in the Red River Delta. The dyke system regulates the discharge and water exchange inside the diked area including irrigation channels for the paddy rice production. Local authorities observed increasing pollution towards the sea (highest pollution close to the dykes) and hypothesized that the dyke system would prevent water exchange and thus lead to an accumulation of pollutants within the diked area. Hence, the purpose of this study was to investigate the effect of dykes on pesticide pollution patterns in coastal delta regions of the Red River Delta. The study was conducted in the district Giao Thuy of the Red River Delta, Vietnam. This area is surrounded by a sea and river dyke; both have several inlet and outlet gates to control the water level in the irrigation channels. We determined the pesticide pollution pattern in a diked agricultural area, as well as along salinity gradients in and outside the diked areas. Samples were taken from rice fields and sediments from irrigation channels inside the diked area as well from saline aquaculture fields located outside the dyke. Pesticide analysis was conducted by accelerated solvent extraction (ASE), followed up by the clean-up process described by Laabs et al. (2007) and analyses using gas chromatography coupled with a mass selective detector (MSD). Preliminary results suggest that out of the 26 analysed compounds chlorpyrifos, propiconazole and

  13. HIV infection, risk factors, and preventive services utilization among female sex workers in the Mekong Delta Region of Vietnam.

    Directory of Open Access Journals (Sweden)

    Bach Xuan Tran

    Full Text Available BACKGROUND: Risk behaviors among female sex workers (FSW are considerable drivers of HIV infections in Vietnam, especially transmission between high-risk and low-risk groups. We assessed HIV prevalence and its correlates among FSWs, and the use of preventive services among this community in the Mekong Delta region, southern Vietnam. METHODS: A cross-sectional survey of 1,999 FSWs was carried out in five provinces including Ben Tre, Hau Giang, Kien Giang, Tien Giang, and Vinh Long between June, 2006 and June, 2007. We interviewed participants face-to-face in order to elicit information about their lives and potential risk factors, and we tested their sera to determine their HIV status. We then performed multivariate logistic regression analyses to investigate factors associated with HIV infection. RESULTS: Seventeen percent of the participating FSWs were street-based sex workers (SSWs and the rest (83% were entertainment establishment-based sex workers (ESWs. Unprotected sex with regular and casual clients in the past month was frequent among study participants (40.5% and 33.5% respectively. However, few respondents (1.3% had ever injected drugs. Only 2.1% (95% confidence interval (CI: 1.6%-2.8% of FSWs were found to be infected with HIV. HIV prevalence among SSWs was greater than among ESWs (3.8% vs. 1.8%, p = 0.02, respectively. Increased risk for HIV infection was significantly associated with the number of clients per month (adjusted odd ratio (aOR = 2.65, 95% CI: 1.26-5.59. CONCLUSIONS: Interventions to reduce unsafe sex and drug injection, and to increase uptake of HIV testing among FSWs are necessary. Differences in HIV prevalence and its correlates by type of sex work emphasize the importance of constrained contexts in shaping risk behaviors among FSWs; that should be considered in designing HIV prevention programs.

  14. Application of discrete choice experiment to assess farmers' willingness to report swine diseases in the Red River Delta region, Vietnam.

    Science.gov (United States)

    Pham, Hoa T T; Peyre, Marisa; Trinh, Tuyen Quang; Nguyen, Oanh Cong; Vu, Ton Dinh; Rukkwamsuk, Theera; Antoine-Moussiaux, Nicolas

    2017-03-01

    A discrete choice experiment (DCE) is carried out to value socio-economic factors influencing the farmer's decision to report swine diseases and to assess the willingness of farmers to report swine diseases. Data were collected between March and July 2015 in two provinces in the Red River Delta, Northern Vietnam, from 196 pig producers by face-to face interview. A conditional logit model is used to measure the relative importance of the socio-economic factors and calculate the expected probability of disease reporting under changes of levels of these factors. Results of the study indicated that the likelihood of compensation and the type of culling implemented (all or only unrecovered pigs) are the two most important factors influencing farmer reporting. Compensation level, movement restriction and delay in compensation payment also have significant impacts on farmer's decision to report animal disease but they are not as important as the above factors. Three different scenarios including changes in six different factors (attributes) are tested to predict probability of animal disease reporting. Under the current situation (uncertainty of being compensated), only 4% of the farmers would report swine disease outbreak to the official surveillance system if the culling policy involves all pigs in affected farms. This number is increased to 26% if culling in affected farms is restricted to unrecovered pigs only. Ensuring certainty of compensation increases reporting probability by up to 50% and 90% if all or only unrecovered pigs are destroyed, respectively. The results of this study are important for improving the performance and sustainability of swine disease surveillance system in Vietnam. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Rodents and risk in the Mekong Delta of Vietnam: seroprevalence of selected zoonotic viruses in rodents and humans.

    Science.gov (United States)

    Van Cuong, Nguyen; Carrique-Mas, Juan; Vo Be, Hien; An, Nguyen Ngoc; Tue, Ngo Tri; Anh, Nguyet Lam; Anh, Pham Hong; Phuc, Nguyen The; Baker, Stephen; Voutilainen, Liina; Jääskeläinen, Anne; Huhtamo, Eili; Utriainen, Mira; Sironen, Tarja; Vaheri, Antti; Henttonen, Heikki; Vapalahti, Olli; Chaval, Yannick; Morand, Serge; Bryant, Juliet E

    2015-01-01

    In the Mekong Delta in southern Vietnam, rats are commonly traded in wet markets and sold live for food consumption. We investigated seroprevalence to selected groups of rodent-borne viruses among human populations with high levels of animal exposure and among co-located rodent populations. The indirect fluorescence antibody test (IFAT) was used to determine seropositivity to representative reference strains of hantaviruses (Dobrava virus [DOBV], Seoul virus [SEOV]), cowpox virus, arenaviruses (lymphocytic choriomeningitis virus [LCMV]), flaviviruses (tick-borne encephalitis virus [TBEV]), and rodent parechoviruses (Ljungan virus), using sera from 245 humans living in Dong Thap Province and 275 rodents representing the five common rodent species sold in wet markets and present in peridomestic and farm settings. Combined seropositivity to DOBV and SEOV among the rodents and humans was 6.9% (19/275) and 3.7% (9/245), respectively; 1.1% (3/275) and 4.5% (11/245) to cowpox virus; 5.4% (15/275) and 47.3% (116/245) for TBEV; and exposure to Ljungan virus was 18.8% (46/245) in humans, but 0% in rodents. Very little seroreactivity was observed to LCMV in either rodents (1/275, 0.4%) or humans (2/245, 0.8%). Molecular screening of rodent liver tissues using consensus primers for flaviviruses did not yield any amplicons, whereas molecular screening of rodent lung tissues for hantavirus yielded one hantavirus sequence (SEOV). In summary, these results indicate low to moderate levels of endemic hantavirus circulation, possible circulation of a flavivirus in rodent reservoirs, and the first available data on human exposures to parechoviruses in Vietnam. Although the current evidence suggests only limited exposure of humans to known rodent-borne diseases, further research is warranted to assess public health implications of the rodent trade.

  16. Factors affecting farmers' adoption of integrated rice-fish farming systems in the Mekong delta, Vietnam

    NARCIS (Netherlands)

    Bosma, R.H.; Nhan, D.K.; Udo, H.M.J.; Kaymak, U.

    2012-01-01

    This study investigated the determinants of the adoption of improved rice–fish farming systems in the Mekong delta to support policy making, agricultural land-use planning and extension of integrated rice–fish farming. Recently these systems have been referred to as adaptations to climate change, wh

  17. Present status of radiation processing and its future development by using electron accelerator in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Tran Khac An; Tran Tich Canh; Doan Binh [Research and Development Center for Radiation Technology (VINAGAMMA), Ho Chi Minh (Viet Nam); Nguyen Quoc Hien [Nuclear Research Institute (NRI), Dalat (Viet Nam)

    2003-02-01

    In Vietnam, studies on Radiation Processing have been carried out since 1983. Some results are applicable in the field of agriculture, health and foodstuff, some researches were developed to commercial scale and others have high potential for development by using electron accelerator. The paper offers the present status of radiation processing and also give out the growing tendency of using electron accelerator in the future. (author)

  18. Learning from the Neighbors: Economic and Environmental Impacts from Intensive Shrimp Farming in the Mekong Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Thuy T.H. Nguyen

    2010-07-01

    Full Text Available Intensive shrimp farming is a lucrative and highly risky business. Before entering this industry, most farmers spend time observing the operation of pilot farms. This stage is important to master essential techniques and judge the profitability and risk associated with shrimp farming. Learning is a complex process that leads to misconceptions about the nature of short-term and long-term risks. This paper uses computer simulation to illuminate the dynamic nature of the learning processes, land conversion, shrimp production and environmental contamination. The model is based on conditions of the Dai Hoa Loc Commune in the Mekong Delta of Vietnam. Initial simulations match statistical data by revealing the high risk: high initial profits from the pilot farms followed by conversion from rice land to shrimp farms. When rapid conversion occurs, the region is vulnerable to excessive accumulation of nutrients, a decline in shrimp yields and financial failure. In contrast, low stock densities deliver a lower profit which is insufficient to stimulate mass land conversion. The paper concludes with testing recovery strategies for farmers who have suffered the longer term impacts of high stocking density. Results show that yield recovery is possible by improving the channel and imposing regulatory control over stocking density.

  19. Sex pheromones of three citrus leafrollers, Archips atrolucens, Adoxophyes privatana, and Homona sp., inhabiting the Mekong Delta of Vietnam.

    Science.gov (United States)

    Van Vang, Le; Thuy, Ho Nhu; Khanh, Chau Nguyen Quoc; Son, Pham Kim; Yan, Qi; Yamamoto, Masanobu; Jinbo, Utsugi; Ando, Tetsu

    2013-06-01

    Archips atrolucens, Adoxophyes privatana, and Homona sp. are serious defoliators of citrus trees in the Mekong Delta of Vietnam. In order to establish a sustainable pest-management program for the three species, their female-produced sex pheromones were investigated by GC-EAD and GC-MS analyses, and the following multi-component pheromones were identified: (Z)-11-tetradecenyl acetate (Z11-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc), and tetradecyl acetate (14:OAc) in a ratio of 64:32:4 for A. atrolucens; Z11-14:OAc and (Z)-9-tetradecenyl acetate (Z9-14:OAc) in a ratio of 92:8 for A. privatana; and Z11-14:OAc and (Z)-9-dodecenyl acetate (Z9-12:OAc) in a ratio of 96:4 for Homona sp. Each lure baited with synthetic components as a mimic of the natural pheromone attracted males of the target species specifically, indicating that each monounsaturated minor component plays a significant role for mating communication and reproductive isolation of the three species inhabiting the same citrus orchards. In an extract of the pheromone glands of A. atrolucens females, the content of 14:OAc was very low, but a synergistic effect was observed clearly when the saturated compound was mixed at the same level as the E11-14:OAc. The synthetic lures will provide useful tools for monitoring flights of adults of the three species.

  20. Simulated impacts of climate change on current farming locations of striped catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, Anh L; Dang, Vinh H; Bosma, Roel H; Verreth, Johan A J; Leemans, Rik; De Silva, Sena S

    2014-12-01

    In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta's economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these influences. In this study, water level rise and salt water intrusion for three sea level rise (SLR) scenarios (i.e., +30, +50, and +75 cm) were simulated. The results showed that at SLR +50, the 3-m-flood level would spread downstream and threaten farms located in AnGiang, DongThap and CanTho provinces. Rising salinity levels for SLR +75 would reduce the window appropriate for the culture in SocTrang and BenTre provinces, and in TienGiang's coastal districts. Next to increasing dikes to reduce the impacts, the most tenable and least disruptive option to the farming community would be to shift to a salinity tolerant strain of catfish.

  1. Effects of local and spatial conditions on the quality of harvested rainwater in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Wilbers, Gert-Jan; Sebesvari, Zita; Rechenburg, Andrea; Renaud, Fabrice G

    2013-11-01

    The objective of this study was to assess the quality of harvested rainwater in the Mekong Delta (MD), Vietnam for local (roof types, storage system and duration) and spatial (proximity of industry, main roads, coastline) conditions. 78 harvested rainwater samples were collected in the MD and analyzed for pH, turbidity, TDS, COD, nutrients (NH4, NO3, NO2, o-PO4), trace metals and coliforms. The results show that thatch roofs lead to an increase of pollutants like COD (max 23.2 mgl(-1)) and turbidity (max 10.1 mgl(-1)) whereas galvanized roofs lead to an increase of Zn (max 2.2 mgl(-1)). The other local and spatial parameters had no or only minor influence on the quality of household harvested rainwater. However, lead (Pb) (max. 16.9 μgl(-1)) and total coliforms (max. 102 500 CFU100 ml(-1)) were recorded at high concentrations, probably due to a variety of household-specific conditions such as rainwater storage, collection and handling practices.

  2. Hydraulic Bureaucracy in a Modern Hydraulic Society – Strategic Group Formation in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Hans-Dieter Evers

    2009-10-01

    Among these strategic groups, the hydraulic bureaucracy and hydraulic construction business are the most crucial in terms of the specific role they play in the hydraulic landscape of the Mekong delta. Both groups exert considerable influence on water resources management and strive for the same resources, namely public funds (including Overseas Development Aid that is directed to hydraulic infrastructure development. This paper illustrates how both groups have emerged due to the growing need for water resources management in the delta and how they have set up alliances for mutually sharing resources in the long run. Furthermore, it is shown how both groups have adapted their resource-oriented strategies and actions to respond to the changes in the economic and political environment in Vietnam’s recent history.

  3. Holocene evolution of the Song Hong (Red River) delta system, northern Vietnam

    Science.gov (United States)

    Tanabe, Susumu; Saito, Yoshiki; Lan Vu, Quang; Hanebuth, Till J. J.; Lan Ngo, Quang; Kitamura, Akihisa

    2006-05-01

    The Song Hong (Red River) delta, located on the western coast of the Gulf of Bac Bo (Tonkin) in the South China Sea, formed as a result of the Song Hong sediment discharge throughout the Holocene. The river's sedimentary basin upstream from the delta plain is not large. The delta plain comprises emerged tidal/mangrove flats formed during the sea-level highstand at + 2-3 m (6-4 cal. kyr BP) and a beach-ridge strandplain, with straight-to-lobate beach ridges, on the landward and seaward sides of the delta plain, respectively. The delta affords us the opportunity to examine river-mouth morphodynamics comprehensively in relation to sediment discharge and sea-level changes. In this paper, we describe the Holocene evolution of the Song Hong delta system and the river-mouth morphodynamics on the basis of seven sediment cores, each 30-70 m long, taken from the delta plain during 1999-2001 and 101 radiocarbon dates obtained from the core sediments. Sediments from the seven cores, consisting of incised-valley fills since the last glacial maximum, can be divided, in ascending order, into fluvial sediments composed of gravelly sand and mottled clay, tide-influenced estuarine sediments containing shell and wood fragments, and deltaic sediments composed of tide-influenced sand and mud deposits, in which the contents of sand and wood fragments increase upward. By applying sequence stratigraphic concepts, a transgressive surface can be identified at the gravelly sand-mottled clay boundary, and the maximum flooding surface can be identified at the estuarine-deltaic sediments boundary. The lowstand systems tract, transgressive systems tract, and highstand systems tract record ˜15, 15-9, and 9-0 cal. kyr BP, respectively. During the past 9 kyr, the majority of the sediment discharged by the Song Hong accumulated in the incised valley and enhanced progradation at the river mouth. The river mouth prograded from the bay head toward the gulf, and its morphology changed from funnel

  4. Soil salinity and sodicity in a shrimp farming coastal area of the Mekong Delta, Vietnam

    Science.gov (United States)

    Tho, Nguyen; Vromant, N.; Hung, Nguyen Thanh; Hens, L.

    2008-06-01

    Soil salinity and sodicity are environmental problems in the shrimp farming areas of the Cai Nuoc district, Ca Mau province, Vietnam. In 2000, farmers in the district switched en masse from rice cropping to shrimp culture. Due to recent failure in shrimp farming, many farmers wish to revert to a rotational system with rice in the wet season and shrimps in the dry season. So far, all their attempts to grow rice have failed. To assess soil salinity and sodicity, 25 boreholes in shrimp ponds were analysed in four consecutive seasons from 2002 to 2004. The results showed that soil salinity was quite serious (mean ECe 29.25 dS m-1), particularly in the dry season (mean ECe 33.44 dS m-1). In the wet season, significant amounts of salts still remained in the soil (mean ECe 24.65 dS m-1) and the highest soil salinity levels were found near the sea. Soil sodicity is also a problem in the district (exchangeable sodium percentage range 9.63-72.07%). Sodicity is mainly a phenomenon of topsoils and of soils near the sea. Both soil salinity and sodicity are regulated by seasonal rainfall patterns. They could together result in disastrous soil degradation in the Cai Nuoc district.

  5. Electronic properties of delta -doped GaAs

    Science.gov (United States)

    Gold, A.; Ghazali, A.; Serre, J.

    1992-07-01

    For temperature zero the authors study the effects of disorder on the electronic properties of the two-dimensional electron gas which exists in planar-doped ( delta -doped) GaAs. The density of states, the Fermi level, the single-particle relaxation time and the electron mobility are calculated as functions of the dopant concentration. The transition from a band tail to an impurity band and the nature of the metal-insulator transition are discussed. The authors compare the theoretical results on the mobility with some available experimental data.

  6. The combined impact on the flooding in Vietnam's Mekong River delta of local man-made structures, sea level rise, and dams upstream in the river catchment

    Science.gov (United States)

    Le, Thi Viet Hoa; Nguyen, Huu Nhan; Wolanski, Eric; Tran, Thanh Cong; Haruyama, Shigeko

    2007-01-01

    The Mekong River delta plays an important role in the Vietnamese economy and it has been severely impacted during this century by a series of unusually large floods. In the dry season the delta is also impacted by salinity intrusion and tides. These effects have caused severe human hardship. To mitigate these impacts, a large number of engineering structures, primarily dykes and weirs, have been built in the delta in recent years and are still being built, mainly to control floods and saltwater intrusion. These control measures are still being upgraded. A GIS-linked numerical model shows that the flood levels in the delta depend on the combined impacts of high river flows in the Mekong River, storm surges, sea level rise, and the likely, future siltation of the Mekong Estuary resulting from the construction of dams in China as well as many other dams proposed throughout the remaining river catchment. The model suggests that the engineering structures in the delta increase the flow velocities in the rivers and canals, increasing bank erosion, and cause the water to be deeper in the rivers and canals. This increases flooding in the non-protected areas of the delta and increases the risk of catastrophic failure of the dykes in the protected areas. The model also predicts that a sea level rise induced by global warming will enhance flooding in the Mekong River delta in Vietnam, and that flooding may worsen in the long term as a result of estuarine siltation resulting from the construction of dams. At the scale of the Mekong River basin, a multinational water resources management plan is needed that includes the hydrological needs of the delta. At the scale of the delta, a compromise is needed between allowing some flooding necessary for agriculture and preventing catastrophic flooding to alleviate human suffering.

  7. Osmoregulatory and immunological status of the pond-raised striped catfish (Pangasianodon hypophthalmus S.) as affected by seasonal runoff and salinity changes in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Schmitz, Mélodie; Baekelandt, Sébastien; Tran Thi, Lam Khoa; Mandiki, Syaghalirwa N M; Douxfils, Jessica; Nguyen, Thinh Quoc; Do Thi Thanh, Huong; Kestemont, Patrick

    2017-02-01

    In Vietnam, the production of striped catfish Pangasianodon hypophthalmus S. reached more than 1.2 millions of tons in 2014 and is mainly gathered in the Mekong Delta (South Vietnam). A survey was carried out during the dry season 2013 (March-April) and rainy season 2014 (July-August) in 12 fish farms of the lower (Tra Vinh Province) and higher (Can Tho Province) Mekong River Delta. This study allowed drawing up current key osmoregulatory and innate immune parameters of striped catfish in aquaculture depending on the geographical location, particularly the proximity to the River Mekong Estuary and the seasonal surface runoff. In the dry season, plasma osmolality was positively correlated with salinity. Gill Na(+)K(+) ATPase dropped in the rainy season, while kidney Na(+)K(+) ATPase remained stable. Abundance of immune blood cells, especially thrombocytes and monocytes, tended to increase in farms located in tidal area. Production of reactive oxygen species in the spleen, kidney lysozyme activity and plasma complement activity did not vary whatever the season or the proximity to the estuary. Plasma lysozyme activity was 50-fold higher than in kidney and increased in the rainy season as well as in tidal sites. Kidney complement activity decreased in the dry season, especially in tidal sites. In conclusion, regarding key osmoregulatory and immune factors, striped catfish farms located in the Mekong Delta may be affected by seasonal and regional salinity and runoff fluctuations.

  8. Piped-Water Supplies in Rural Areas of the Mekong Delta, Vietnam: Water Quality and Household Perceptions

    Directory of Open Access Journals (Sweden)

    Gert-Jan Wilbers

    2014-07-01

    Full Text Available In the Mekong Delta (MD in Vietnam, piped-water supply stations are being intensively built to reach the millennium development goal (MDG to provide safe and clean drinking water resources to communities. However, studies focusing on the effectiveness of supply stations in reaching these goals are scarce to date. Water samples from 41 water supply stations in the MD were collected between June and October 2012. Water samples were analyzed for general parameters, salinity, nutrients, metal(loids and microbial indicator bacteria and compared with World Health Organization (WHO and Vietnamese drinking water guidelines. In addition, 542 household interviews were conducted to investigate the connection rate to piped-water and people’s perceptions regarding piped-water supplies. The results show that water guidelines were exceeded for pH (min. 6.2, turbidity (max. 10 FTU, Cl (max. 1,576 mg·L−1, NH4 (max. 7.92 mg·L−1, Fe (431.1 µg·L−1, Hg (11.9 µg·L−1, and microbial indicator bacteria (max. total coliform 50,000 CFU 100 mL−1. Moreover, more than half of the interviewed households with access to a piped-water supply did not use this supply as a source of drinking water due to (i high connection fees; (ii preference for other water sources; and (iii perceived poor quality/quantity. Our study shows that the maintenance and distribution of water supply stations should significantly improve in order for piped-water to become a reliable drinking water source. Additionally, alternatives, such as rainwater harvesting and decentralized treatment facilities, should also be considered.

  9. A Phenology-Based Classification of Time-Series MODIS Data for Rice Crop Monitoring in Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen-Thanh Son

    2013-12-01

    Full Text Available Rice crop monitoring is an important activity for crop management. This study aimed to develop a phenology-based classification approach for the assessment of rice cropping systems in Mekong Delta, Vietnam, using Moderate Resolution Imaging Spectroradiometer (MODIS data. The data were processed from December 2000, to December 2012, using empirical mode decomposition (EMD in three main steps: (1 data pre-processing to construct the smooth MODIS enhanced vegetation index (EVI time-series data; (2 rice crop classification; and (3 accuracy assessment. The comparisons between the classification maps and the ground reference data indicated overall accuracies and Kappa coefficients, respectively, of 81.4% and 0.75 for 2002, 80.6% and 0.74 for 2006 and 85.5% and 0.81 for 2012. The results by comparisons between MODIS-derived rice area and rice area statistics were slightly overestimated, with a relative error in area (REA from 0.9–15.9%. There was, however, a close correlation between the two datasets (R2 ≥ 0.89. From 2001 to 2012, the areas of triple-cropped rice increased approximately 31.6%, while those of the single-cropped rain-fed rice, double-cropped irrigated rice and double-cropped rain-fed rice decreased roughly −5.0%, −19.2% and −7.4%, respectively. This study demonstrates the validity of such an approach for rice-crop monitoring with MODIS data and could be transferable to other regions.

  10. Salt intrusion in multi-channel estuaries: a case study in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    A. D. Nguyen

    2006-01-01

    Full Text Available There is a well-tested theory for the computation of salt intrusion in alluvial estuaries that is fully analytical and predictive. The theory uses analytical equations to predict the mixing behaviour of the estuary based on measurable quantities, such as channel topography, river discharge and tidal characteristics. It applies to single-channel topographies and estuaries that demonstrate moderate tidal damping. The Mekong delta is a multi-channel estuary where the tide is damped due to a relatively strong river discharge (in the order of 2000 m3/s, even during the dry season. As a result the Mekong is a strongly riverine estuary. This paper aims to test if the theory can be applied to such a riverine multi-channel estuary, and to see if possible adjustments or generalisations need to be made. The paper presents salt intrusion measurements that were done by moving boat in 2005, to which the salt intrusion model was calibrated. The theory has been expanded to cater for tidal damping. Subsequently the model has been validated with observations made at fixed locations over the years 1998 and 1999. Finally it has been tested whether the Mekong calibration fits the overall predictive equations derived in other estuaries. The test has been successful and led to a slight adjustment of the predictive equation to cater for estuaries that experience a sloping bottom.

  11. Farmers' Perceived Risks of Climate Change and Influencing Factors: A Study in the Mekong Delta, Vietnam

    Science.gov (United States)

    Le Dang, Hoa; Li, Elton; Nuberg, Ian; Bruwer, Johan

    2014-08-01

    Many countries are confronting climate change that threatens agricultural production and farmers' lives. Farmers' perceived risks of climate change and factors influencing those perceived risks are critical to their adaptive behavior and well-planned adaptation strategies. However, there is limited understanding of these issues. In this paper, we attempt to quantitatively measure farmers' perceived risks of climate change and explore the influences of risk experience, information, belief in climate change, and trust in public adaptation to those perceived risks. Data are from structured interviews with 598 farmers in the Mekong Delta. The study shows that perceived risks to production, physical health, and income dimensions receive greater priority while farmers pay less attention to risks to happiness and social relationships. Experiences of the events that can be attributed to climate change increase farmers' perceived risks. Information variables can increase or decrease perceived risks, depending on the sources of information. Farmers who believe that climate change is actually happening and influencing their family's lives, perceive higher risks in most dimensions. Farmers who think that climate change is not their concern but the government's, perceive lower risks to physical health, finance, and production. As to trust in public adaptation, farmers who believe that public adaptive measures are well co-ordinated, perceive lower risks to production and psychology. Interestingly, those who believe that the disaster warning system is working well, perceive higher risks to finance, production, and social relationships. Further attention is suggested for the quality, timing, and channels of information about climate change and adaptation.

  12. Status and changes of mangrove forest in Mekong Delta: Case study in Tra Vinh, Vietnam

    Science.gov (United States)

    Thu, Phan Minh; Populus, Jacques

    2007-01-01

    Because shrimp culture in the Mekong Delta develops rapidly, it has negatively impacted the environment, socio-economics and natural resources. In particular, mangrove forests have been altered by the shrimp culture. The area of mangrove forests in the region has been reduced and this is seen especially in Tra Vinh province. The results obtained from GIS (Geography Information System) and RS (Remote Sensing) show the status of mangrove forests in Tra Vinh province in 1965, 1995 (Northeastern part of Tra Vinh Province) and 2001. In 1965, the area of mangrove forests was 21,221 ha making up 56% of total land-use, while in 2001 it was 12,797 ha making up 37% of total land-use. Also based on GIS analysis, over the 36 years (1965-2001), the total coverage of mangrove forests have decreased by 50% since 1965. However, the speed of mangrove forest destruction in the period from 1965 to 1995 was much less than that in the period from 1995 to 2001. The average annual reduction in mangrove forest coverage in the first period (1965-1995) was 0.2% whereas it was 13.1% in the later period (1995-2001). For the long time, mangrove deforestation has been caused by war, collection of firewood and clearing for agriculture, and recently, shrimp farming has significantly contributed rate of mangrove destruction.

  13. Spatial and temporal variability of surface water pollution in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Wilbers, Gert-Jan; Becker, Mathias; Nga, La Thi; Sebesvari, Zita; Renaud, Fabrice G

    2014-07-01

    Surface water pollution in the Vietnamese Mekong Delta (MD) could threaten human, animal and ecosystem health given the fact that this water source is intensively used for drinking, irrigation and domestic services. We therefore determined the levels of pollution by organic pollutants, salts, metals and microbial indicators by (bi)monthly monitoring of canals between November 2011 and July 2012 at 32 sampling locations, representing fresh and saline/brackish environments. The results were compared with national water quality guidelines, between the studied regions and with water quality data from main waterways. Key factors explaining the observed levels of pollution in surface water were identified through principal component analysis (PCA). Temporal variations due to tidal regime and seasonality were also assessed. Based on regression models, the spatial variability of five water quality parameters was visualized using GIS based maps. Results indicate that pH (max. 8.6), turbidity (max. 461 FTU), maximum concentrations of ammonium (14.7 mg L(-1)), arsenic (44.1 μg L(-1)), barium (157.5 μg L(-1)), chromium (84.7 μg L(-1)), mercury (45.5 μg L(-1)), manganese (1659.7 μg L(-1)), aluminum (14.5 mg L(-1)), iron (17.0 mg L(-1)) and the number of Escherichia coli (87,000 CFU 100 mL(-1)) and total coliforms (2,500,000 CFU 100 mL(-1)) in canals exceed the thresholds set by Vietnamese quality guidelines for drinking and domestic purposes. The PCA showed that i) urbanization; ii) metal leaching from soils; iii) aquaculture; and iv) tidal regime explain 85% of the variance of surface water quality attributes. Significant differences in water quality were found due to daily tidal regime and as a result of seasonality. Surface water quality maps for dissolved oxygen, ammonium, ortho-phosphate, manganese and total coliforms were developed to highlight hot-spot areas of pollution. The results of this study can assist policy makers in developing water management strategies

  14. Antagonism of local isolates of Trichoderna spp.on citrus root rot disease by Fusarium solani in the mekong delta of vietnam

    Institute of Scientific and Technical Information of China (English)

    Duong Minh; Jozef Coosemans; Le Lam Cuong; Ester Vandersmissen; Pham Van Kim

    2004-01-01

    @@ The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.

  15. Genesis of economic relevant fresh groundwater resources in Pleistocene/ Neogene aquifers in Nam Dinh (Red River Delta, Vietnam).

    Science.gov (United States)

    Wagner, F.; Ludwig, R. R.; Noell, U.; Hoang, H. V.; Pham, N. Q.; Larsen, F.; Lindenmaier, F.

    2012-04-01

    In the Southern Red River Delta (Nam Dinh Province, Vietnam), a local lens of low saline pore water of high quality has been identified in unconsolidated Pleistocene and Neogene aquifers, which are regionally known to contain brackish and saline pore waters. Since the 1990ies, ongoing overexploitation of the fresh groundwater results in decreasing GW heads up to 0.6 m/a and the development of a regional abstraction cone. The presented study focuses on distribution and genesis of fresh and saline pore waters and reflects the results in frame of the regional hydrogeological context. Observations of the geological structure and groundwater dynamics combined with hydrochemical and isotopic studies suggest adjacent Triassic hard rock aquifers as the major source for fresh Pleistocene and Neogene groundwater. Salinization status in the economically most relevant Pleistocene aquifer has been studied based on archive and new hydrochemical and geophysical data. Own hydrochemical field studies as well as laboratory measurements of the specific resistivity of dry sediment samples allow the translation of induction logging data from existing monitoring wells into vertical pore water salinity profiles. This approach suggests the regional occurrence of saline pore water in shallow Holocene sediments in the working area, as confirmed by pore water studies in Hoan et al. (2010). Interpretation of induction logging and stable isotope data suggest vertical diffusion of saline pore water in shallow Holocene sediments as a source for high saline pore water in deeper aquifers. Analytical diffusion modeling for a period of 3000 years confirms that vertical diffusion of Holocene paleo-sea water can explain saline pore water in Pleistocene and Neogene aquifers in a stagnant environment. The constant influx of fresh groundwater from adjacent Triassic hard rocks results in flushing of the primary Pleistocene and Neogene pore water and inhibits the infiltration of saline water from marine

  16. Mapping the irrigated rice cropping patterns of the Mekong delta, Vietnam, through hyper - temporal SPOT NDVI image analysis

    NARCIS (Netherlands)

    Nguyen, T.T.H.; Bie, de C.A.J.M.; Ali, A.; Smaling, E.M.A.

    2012-01-01

    Successful identification and mapping of different cropping patterns under cloudy conditions of a specific crop through remote sensing provides important baseline information for planning and monitoring. In Vietnam, this information is either missing or unavailable; several ongoing projects studying

  17. Mapping the irrigated rice cropping patterns of the Mekong delta, Vietnam through hyper-temporal SPOT NDVI image analysis

    NARCIS (Netherlands)

    Nguyen, Thi Thu Ha; Bie, de C.A.J.M.; Ali, A.; Smaling, E.M.A.; Hoanh, C.T.

    2012-01-01

    Successful identification and mapping of different cropping patterns under cloudy conditions of a specific crop through remote sensing provides important baseline information for planning and monitoring. In Vietnam, this information is either missing or unavailable; several ongoing projects studying

  18. Geochemical processes underlying a sharp contrast in groundwater arsenic concentrations in a village on the Red River delta, Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Eiche, Elisabeth [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany)], E-mail: elisabeth.eiche@img.uni-karlsruhe.de; Neumann, Thomas [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany); Berg, Michael [Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Duebendorf (Switzerland); Weinman, Beth [Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240 (United States); Geen, Alexander van [Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964 (United States); Norra, Stefan; Berner, Zsolt [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany); Pham Thi Kim Trang; Pham Hung Viet [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Stueben, Doris [Institute of Mineralogy and Geochemistry, Universitaet Karlsruhe - TH, 76131 Karlsruhe (Germany)

    2008-11-15

    The spatial variability of As concentrations in aquifers of the Red River Delta, Vietnam, was studied in the vicinity of Hanoi. Two sites, only 700 m apart but with very different As concentrations in groundwater (site L: <10 {mu}g/L vs. site H: 170-600 {mu}g/L) in the 20-50 m depth range, were characterized with respect to sediment geochemistry and mineralogy as well as hydrochemistry. Sequential extractions of the sediment were carried out in order to understand why As is released to groundwater at one site and not the other. No major differences were observed in the bulk mineralogy and geochemistry of the sediment, with the exception of the redox state of Fe oxyhydroxides inferred from sediment colour and diffuse spectral reflectance. At site H most of the As in the sediment was adsorbed to grey sands of mixed Fe(II/III) valence whereas at site L As was more strongly bound to orange-brown Fe(III) oxides. Higher dissolved Fe and low dissolved S concentrations in groundwater at site H ({approx}14 mg Fe/L, <0.3 mg S/L) suggest more strongly reducing conditions compared to site L (1-2 mg Fe/L, <3.8 mg S/L). High concentrations of NH{sub 4}{sup +} ({approx}10 mg/L), HCO{sub 3}{sup -} (500 mg/L) and dissolved P (600 mg/L), in addition to elevated As at site H are consistent with a release coupled to microbially induced reductive dissolution of Fe oxyhydroxides. Other processes such as precipitation of siderite and vivianite, which are strongly supersaturated at site H, or the formation of amorphous Fe(II)/As(III) phases and Fe sulfides, may also influence the partitioning of As between groundwater and aquifer sands. The origin of the redox contrast between the two sites is presently unclear. Peat was observed at site L, but it was embedded within a thick clayey silt layer. At site H, instead, organic rich layers were only separated from the underlying aquifer by thin silt layers. Leaching of organic matter from this source could cause reducing conditions and therefore

  19. Survey of current crop management practices in a mixed-ricefield landscape, Mekong Delta, Vietnam - potential of habitat manipulation for improved control of citrus leafminer and citrus red mite

    NARCIS (Netherlands)

    Mele, van P.; Lenteren, van J.C.

    2002-01-01

    In the Mekong Delta, Vietnam, the citrus leafminer Phyllocnistis citrella (CLM) and the citrus red mite Panonychus citri are major pests in both sweet orange (Citrus sinensis) and Tieu mandarin (C. reticulata). Survey data indicate that these pest problems might be aggravated after farmers have comp

  20. Impacts of changes in mangrove forest management practices on forest accessibility and livelihood: A case study in mangrove-shrimp farming system in Ca Mau Province, Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Ha, T.T.P.; Dijk, van J.W.M.; Visser, L.E.

    2014-01-01

    This paper documents how the implementation of forest tenure policy affects the decision-making of farmers in mangrove-shrimp farming systems with regard to their access to and management of mangrove forest in Ca Mau, Mekong Delta, which is the largest remaining mangrove forest in Vietnam. Policies

  1. Early Performance of Duong Mandarin (Citrus reticulata Blanco on Three Rootstock under Acid Sulfate Soil Fields at Mekong Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Khoe Thi Le

    2016-01-01

    Full Text Available Abstract About 1.6 billion hectare area of acid sulfate soils is at Mekong Delta of Vietnam, and Duong mandarin fruits are valued for the fresh market due to the easy peeling, attractive flavor, and health and nutritional properties; thereby, the investigation on early performance of Duong mandarin on three rootstock under acid sulfate soil fields (pH below 4 at Mekong Delta of Vietnam was undertaken from 2009 to 2012 for determination of the most promising scion stock combination of Duong mandarin, which introduced to growers for expanding citrus production to increase in income of farmers, and helping to use the sustainable and efficient land resource at acid sulfate soil region of Mekong Delta. Primary results showed that Duong mandarin grafted on Mat orange, Tau lemon and Carrizo citrange were significant differenence in vegetative parameters, fruit yield and quality. It proved that Duong mandarin trees grafted on Tau lemon were better growth and development on acid sulfate soil fields with below 4 pH in soil and water suspension of 1:2.5 ratio as compared to those grafted on Mat orange and Carrizo citrange rootstocks; whereby, that induced trees with 171.48 cm height, 6.65 m3 canopy volume and 51.84 mm trunk diameter, 1.08 scion/ stock ratio in third year after growing. Moreover, Duong mandarin trees grafted on Tau lemon were with spreading growth performance. In regarding to fruit yield and quality, Duong mandarin trees grafted on Tau lemon produced highest fruit yield of 9.21 kg per tree per year in third year after planting, and fruit with 115.30g weight, 8.85 brix juice, thinner and somewhat easy peel rind. 

  2. Rice market integration in the Mekong River Delta : The transition to market rules in the domestic food market in Vietnam

    NARCIS (Netherlands)

    Lutz, C.H.M.; Praagman, C.; Hai, L.T.D.

    2006-01-01

    In the last decades Vietnam has become a major supplier in the world's rice market. This position is the result of the policy reforms that have been implemented in the agricultural sector. This paper assesses the impact of the liberalization policies and focuses on the spatial price differences in t

  3. Assessment of the sustainability of the rice-maize cropping system in the Red River Delta of Vietnam and developing reduced tillage practices in rice-maize system in the area

    OpenAIRE

    Le, Thi Thanh Ly

    2015-01-01

    Rice and maize are global staple food and play an important role in world’s food security strategy. Vietnam is one of rice leading export countries but annually it has to import a considerate amount of maize for cattle food processing. Red River Delta in the north of Vietnam is the second rice bucket of the country, which is responsible formore than 20% of total rice production. The priority crops in the areas are rice and maize and rice-maize system is the leading cropping system in the area...

  4. Rice market integration in the Mekong river delta : the successful liberalisation of the domestic food market in Vietnam

    NARCIS (Netherlands)

    Hai, Luu Thanh Duc; Lutz, Clemens; Praagman, Cornelis

    2004-01-01

    This article analyses the spatial price differences in the rice market of the Mekong River Delta to assess the impact of the liberalisation policies on its functioning. The results of these policies carried out during the last two decades are impressive. The rice market system in the Delta is

  5. Molecular characterization of HIV-1 CRF01_AE in Mekong Delta, Vietnam, and impact of T-cell epitope mutations on HLA recognition (ANRS 12159.

    Directory of Open Access Journals (Sweden)

    Estibaliz Lazaro

    Full Text Available BACKGROUND: To date, 11 HIV-1 subtypes and 48 circulating recombinant forms have been described worldwide. The underlying reason why their distribution is so heterogeneous is not clear. Host genetic factors could partly explain this distribution. The aim of this study was to describe HIV-1 strains circulating in an unexplored area of Mekong Delta, Vietnam, and to assess the impact of optimal epitope mutations on HLA binding. METHODS: We recruited 125 chronically antiretroviral-naive HIV-1-infected subjects from five cities in the Mekong Delta. We performed high-resolution DNA typing of HLA class I alleles, sequencing of Gag and RT-Prot genes and phylogenetic analysis of the strains. Epitope mutations were analyzed in patients bearing the HLA allele restricting the studied epitope. Optimal wild-type epitopes from the Los Alamos database were used as reference. T-cell epitope recognition was predicted using the immune epitope database tool according to three different scores involved in antigen processing (TAP and proteasome scores and HLA binding (MHC score. RESULTS: All sequences clustered with CRF01_AE. HLA class I genotyping showed the predominance of Asian alleles as A*11:01 and B*46:01 with a Vietnamese specificity held by two different haplotypes. The percentage of homology between Mekong and B consensus HIV-1 sequences was above 85%. Divergent epitopes had TAP and proteasome scores comparable with wild-type epitopes. MHC scores were significantly lower in divergent epitopes with a mean of 2.4 (±0.9 versus 2 (±0.7 in non-divergent ones (p<0.0001. CONCLUSIONS: Our study confirms the wide predominance of CRF01_AE in the Mekong Delta where patients harbor a specific HLA pattern. Moreover, it demonstrates the lower MHC binding affinity among divergent epitopes. This weak immune pressure combined with a narrow genetic diversity favors immune escape and could explain why CRF01_AE is still predominant in Vietnam, particularly in the Mekong area.

  6. Sex pheromone components and control of the citrus pock caterpillar, Prays endocarpa, found in the Mekong Delta of Vietnam.

    Science.gov (United States)

    Vang, Le Van; Do, Nguyen Duc; An, Le Ky; Son, Pham Kim; Ando, Tetsu

    2011-01-01

    The citrus pock caterpillar, Prays endocarpa (Yponomeutidae; Praydinae), is a pest of pomelo (Citrus grandis L.) in Vietnam. Gas chromatography-mass spectrometry analyses of pheromone gland extracts from female moths identified three monoenyl compounds, (Z)-7-tetradecenal (Z7-14:Ald), (Z)-7-tetradecenyl acetate (tentatively identified, Z7-14:OAc), and (Z)-7-tetradecen-1-ol (Z7-14:OH), in a ratio of about 10:3:10. In the field, traps baited with synthetic Z7-14:Ald (0.5 mg) caught male P. endocarpa. The other two compounds, either alone or when added to Z7-14:Ald, did not elicit increases in trap catch (relative to the appropriate treatment). Synthetic Z7-14:Ald was used to monitor and control this species in pomelo orchards in Vinh Long Province. Monitoring revealed that adults were present throughout the year with discernible peaks in December, March, and April. A mass-trapping trial, using 20 traps in a 0.1 ha pomelo orchard, effectively suppressed fruit damage to levels similar to that achieved by an insecticide (Karate 2.5EC). Mating disruption trials, using polyethylene-tube dispensers, each filled with 80 mg of Z7-14:Ald at a rate of 200 or 400 dispensers/ha, also controlled damage by this pest to levels below that achieved by an insecticide treatment. This work demonstrates the potential for pheromone-based control of this pest in Vietnam.

  7. Water and nutrient budgets of ponds in integrated agriculture-aquaculture systems in the Mekong Delta, Vietnam.

    NARCIS (Netherlands)

    Nhan, D.K.; Verdegem, M.C.J.; Milstein, A.; Verreth, J.A.J.

    2008-01-01

    A participatory on-farm study analysed water and nutrient budgets of six low and four high water-exchange ponds of integrated agriculture-aquaculture (IAA) farms in the Mekong delta. Water, nitrogen (N), organic carbon (OC) and phosphorus (P) flows through the ponds were monitored, and data on fish

  8. Silvicultural management and land characteristics affecting the growth of rhizopora apiculata in Thanh Phu, Ben Tre Province, Mekong delta, Vietnam

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.; McKenzie, P.

    2002-01-01

    During the Indo-China war an estimated 200,000 ha of Vietnamese mangrove forests were destroyed by chemical warfare. Since the war clearance for aquaculture and population pressure caused further deforestation, particularly in the Mekong delta. Mangrove reforestation is desired. At the state farm at

  9. Evaluating sustainable adaptation strategies for vulnerable mega-deltas using system dynamics modelling: Rice agriculture in the Mekong Delta's An Giang Province, Vietnam.

    Science.gov (United States)

    Chapman, Alexander; Darby, Stephen

    2016-07-15

    Challenging dynamics are unfolding in social-ecological systems around the globe as society attempts to mitigate and adapt to climate change while sustaining rapid local development. The IPCC's 5th assessment suggests these changing systems are susceptible to unforeseen and dangerous 'emergent risks'. An archetypal example is the Vietnamese Mekong Delta (VMD) where the river dyke network has been heightened and extended over the last decade with the dual objectives of (1) adapting the delta's 18 million inhabitants and their livelihoods to increasingly intense river-flooding, and (2) developing rice production through a shift from double to triple-cropping. Negative impacts have been associated with this shift, particularly in relation to its exclusion of fluvial sediment deposition from the floodplain. A deficit in our understanding of the dynamics of the rice-sediment system, which involve unintuitive delays, feedbacks, and tipping points, is addressed here, using a system dynamics (SD) approach to inform sustainable adaptation strategies. Specifically, we develop and test a new SD model which simulates the dynamics between the farmers' economic system and their rice agriculture operations, and uniquely, integrates the role of fluvial sediment deposition within their dyke compartment. We use the model to explore a range of alternative rice cultivation strategies. Our results suggest that the current dominant strategy (triple-cropping) is only optimal for wealthier groups within society and over the short-term (ca. 10years post-implementation). The model suggests that the policy of opening sluice gates and leaving paddies fallow during high-flood years, in order to encourage natural sediment deposition and the nutrient replenishment it supplies, is both a more equitable and a more sustainable policy. But, even with this approach, diminished supplies of sediment-bound nutrients and the consequent need to compensate with artificial fertilisers will mean that smaller

  10. Combined fluvial and pluvial urban flood hazard analysis: method development and application to Can Tho City, Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    H. Apel

    2015-08-01

    Full Text Available Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas, and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either fluvial or pluvial flood hazard, studies of combined fluvial and pluvial flood hazard are hardly available. Thus this study aims at the analysis of fluvial and pluvial flood hazard individually, but also at developing a method for the analysis of combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as example. In this tropical environment the annual monsoon triggered floods of the Mekong River can coincide with heavy local convective precipitation events causing both fluvial and pluvial flooding at the same time. Fluvial flood hazard was estimated with a copula based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. Pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data, and a stochastic rain storm generator. Inundation was simulated by a 2-dimensional hydrodynamic model implemented on a Graphical Processor Unit (GPU for time-efficient flood propagation modelling. All hazards – fluvial, pluvial and combined – were accompanied by an uncertainty estimation considering the natural variability of the flood events. This resulted in probabilistic flood hazard maps showing the maximum inundation depths for a selected set of probabilities of occurrence, with maps showing the expectation (median

  11. A Model of Clean Water Supply and Improvement of Enviromental Sanitary Conditions in Residential Clusters in The Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Chi Nguyen Thuy Lan

    2015-12-01

    Full Text Available In accordance with Decision 99/TTg dated 9/2/1996 and Decision 173/TTg dated 6/11/2001 of the Prime Minister regarding the construction program of residential clusters (residential flood free areas, these residential areas as constructed would be fully equipped with critical infrastructures and services such as water supply and drainage works, toilets with sanitary appropriateness, etc. to ensure environmental sanitary conditions in the residential clusters. However, the actual surveys done in residential clusters in the Mekong Delta show that many arising problems must be addressed to enable the local communities to have better living conditions and ensure the sanitary conditions and environmental safety.

  12. Molecular characterization of antibiotic resistance in Pseudomonas and Aeromonas isolates from catfish of the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, Hoang Nam Kha; Van, Thi Thu Hao; Nguyen, Huu Thinh; Smooker, Peter M; Shimeta, Jeff; Coloe, Peter J

    2014-07-16

    A collection of 116 motile Pseudomonas spp. and 92 Aeromonas spp. isolated from 15 Vietnamese intensive catfish farms was analyzed to examine the molecular antibiotic resistance characteristics and the transferability of resistance markers within and between species. High levels of resistance to ampicillin, trimethoprim/sulfamethoxazole, nalidixic acid, chloramphenicol, and nitrofurantoin were observed. The percentage of multiple drug resistance of Pseudomonas spp. and Aeromonas spp. isolates was 96.6% and 61.9%, respectively. The multiple antibiotic resistance (MAR) index mean values of 0.457 and 0.293 of Pseudomonas and Aeromonas isolates, respectively, indicated that these isolates were exposed to high risk sources of contamination where antibiotics were commonly used. Approximately 33% of Pseudomonas spp. and 28% of Aeromonas spp. isolates from catfish contained class 1 integrons, but no class 2 integrons were detected. Several common resistance genes including aadA, dfrA and catB were harbored in class 1 integrons. Large plasmids (>55 kb) were frequently detected in 50% and 71.4% of the plasmids extracted from Pseudomonas and Aeromonas isolates, respectively. Conjugation and transformation experiments demonstrated the successful transfer of all or part of the resistance phenotypes of catfish isolates to the recipient strains, including laboratory strains and strains isolated from this study. These results highlight the likely role of catfish bacteria as a reservoir of antibiotic resistant, Gram-negative bacteria harboring a pool of mobile genetic elements that can readily be transferred intra- and interspecies. To our knowledge, this is the first report on molecular characterization of antibiotic resistance of bacteria isolated from catfish in Vietnam.

  13. Combined fluvial and pluvial urban flood hazard analysis: concept development and application to Can Tho city, Mekong Delta, Vietnam

    Science.gov (United States)

    Apel, Heiko; Martínez Trepat, Oriol; Nghia Hung, Nguyen; Thi Chinh, Do; Merz, Bruno; Viet Dung, Nguyen

    2016-04-01

    Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either a fluvial or pluvial flood hazard, studies of a combined fluvial and pluvial flood hazard are hardly available. Thus this study aims to analyse a fluvial and a pluvial flood hazard individually, but also to develop a method for the analysis of a combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as an example. In this tropical environment the annual monsoon triggered floods of the Mekong River, which can coincide with heavy local convective precipitation events, causing both fluvial and pluvial flooding at the same time. The fluvial flood hazard was estimated with a copula-based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. The pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data and a stochastic rainstorm generator. Inundation for all flood scenarios was simulated by a 2-dimensional hydrodynamic model implemented on a Graphics Processing Unit (GPU) for time-efficient flood propagation modelling. The combined fluvial-pluvial flood scenarios were derived by adding rainstorms to the fluvial flood events during the highest fluvial water levels. The probabilities of occurrence of the combined events were determined assuming independence of the two flood types and taking the seasonality and probability of

  14. HIV voluntary testing and perceived risk among female sex workers in the Mekong Delta region of Vietnam

    Directory of Open Access Journals (Sweden)

    Bach Xuan Tran

    2013-07-01

    Full Text Available Introduction: HIV voluntary counseling and testing (VCT comprise an effective preventive measure and an entry point to care and support services. We sought to assess VCT uptake and HIV-related knowledge and perceived risk among female sex workers (FSWs in five provinces of the Mekong Delta region. Methods: A cross-sectional survey was carried out in 1998 FSWs, including both street-based sex workers (SSWs and entertainment-based sex workers (ESWs. Results: High proportions of FSWs were aware that using condoms (94.6%, and clean needles (34.1% are preventive measures that reduce the risk of HIV transmission. Some FSWs reported avoiding public toilet use (8.6%, physical contacts (16.1%, or sharing meals (10.9% with people living with HIV/AIDS, and preventing mosquito bites (20.8%. Twenty-nine percent (29.0% of FSWs perceived themselves as being at risk of HIV infection. Only 32.7% had ever tested for HIV, of whom 54% were voluntary for testing. FSWs who ever injected drugs (OR = 0.03, p=0.05, had drug-injecting clients (OR = 0.07, p<0.01, and had inconsistent condom use with husbands or lovers (OR = 0.10, p=0.01 were less likely to have a voluntary test. Inconsistent condom use with clients (OR = 13.86, p<0.01, and receiving HIV information from radio (OR = 13.28, p<0.05 and communication campaigns (OR = 6.69, p<0.05, increased the likelihood of VCT uptake. Conclusion: Inadequate knowledge and some misconceptions about HIV transmission routes and preventive measures, low perceived risk of HIV infection, and low VCT uptake were observed among FSWs in the Mekong Delta region. Interventions to improve their knowledge and self-efficacy, reduce risky behaviors, and encourage VCT uptake and early access to health care services are necessary to prevent HIV transmission in this region.

  15. Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach.

    Science.gov (United States)

    Phong, Ngo Dang; Hoanh, Chu Thai; Tuong, To Phuc; Malano, Hector

    2014-07-01

    Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000 ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A Decision Tree Analysis to Support Potential Climate Change Adaptations of Striped Catfish Farming in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen, LA.

    2016-01-01

    Full Text Available This study uses the decision tree framework to analyse possible climate change impact adaptation options for pangasius (Pangasianodon hypopthalmus Sauvage farming in the Mekong Delta. Here we present the risks for impacts and the farmers' autonomous and planned public adaptation by using primary and secondary data. The latter studies showed that a proportion of the pangasius farms located in the coastal provinces will be affected by salinity intrusion in the dry season. Options to adapt to this are: modify pangasius farming practice, stock other species or stock saline-tolerant pangasius. With research and extension support, farmers can further improve their already adapted practice to deal with salinity or use water recirculation systems for prolonged nursery rearing. A breeding program for saline-tolerant striped catfish requires a medium-to long-term investment (0.4% of the production cost from government and/or private company. Pangasius farms in up- and mid-stream regions and in coastal areas, which are not located within upgraded government dyke-protected areas, will be affected by flooding at the end of each rainy season. This implies an increased cost for dykes to about 0.34% and 0.25% of the total variable costs for one harvest per ha in the up- and mid-stream regions, and in the downstream region, respectively.

  17. Rice crop mapping and change prediction using multi-temporal satellite images in the Mekong Delta, Vietnam

    Science.gov (United States)

    Chen, C. R.; Chen, C. F.; Nguyen, S. T.

    2014-12-01

    The rice cropping systems in the Vietnamese Mekong Delta (VMD) has been undergoing major changes to cope with developing agro-economics, increasing population and changing climate. Information on rice cropping practices and changes in cropping systems is critical for policymakers to devise successful strategies to ensure food security and rice grain exports for the country. The primary objective of this research is to map rice cropping systems and predict future dynamics of rice cropping systems using the MODIS time-series data of 2002, 2006, and 2010. First, a phenology-based classification approach was applied for the classification and assessment of rice cropping systems in study region. Second, the Cellular Automata-Markov (CA-Markov) models was used to simulate the rice-cropping system map of VMD for 2010. The comparisons between the classification maps and the ground reference data indicated satisfactory results with overall accuracies and Kappa coefficients, respectively, of 81.4% and 0.75 for 2002, 80.6% and 0.74 for 2006 and 85.5% and 0.81 for 2010. The simulated map of rice cropping system for 2010 was extrapolated by CA-Markov model based on the trend of rice cropping systems during 2002~2006. The comparison between predicted scenario and classification map for 2010 presents a reasonably closer agreement. In conclusion, the CA-Markov model performs a powerful tool for the dynamic modeling of changes in rice cropping systems, and the results obtained demonstrate that the approach produces satisfactory results in terms of accuracy, quantitative forecast and spatial pattern changes. Meanwhile, the projections of the future changes would provide useful inputs to the agricultural policy for effective management of the rice cropping practices in VMD.

  18. Lateral shifts of spin electron beams in antiparallel double {delta}-magnetic-barrier nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Kong Yonghong [Department of Electronic Engineering, Hunan University Science and Engineering, Hunan 425100 (China); Lu Maowang, E-mail: m_w_lu@126.com [Department of Electronic Engineering, Hunan University Science and Engineering, Hunan 425100 (China); Chen Saiyan; Zhang Guilian [Department of Electronic Engineering, Hunan University Science and Engineering, Hunan 425100 (China)

    2012-08-15

    We investigate the Goos-Haenchen (GH) effect of spin electron beams in a magnetic-barrier (MB) nanostructure consisting of antiparallel double {delta}-MBs, which can be experimentally realized by depositing two ferromagnetic (FM) stripes on top and bottom of the semiconductor heterostructure. GH shifts for spin electron beams across this type of MB nanostructures, is derived exactly, with the help of the stationary phase method. It is shown that GH shifts depend strongly on the spin directions for double {delta}-MBs with unidentical magnetic strengths, giving rise to a considerable spin polarization effect. It also is shown that spin polarization of GH shifts is closely relative to the separation and magnetic-strength difference of two {delta}-MBs. These interesting properties may provide an alternative scheme to spin-polarize electrons into the semiconductor, and the devices can serve as tunable spin beam splitters. - Highlights: Black-Right-Pointing-Pointer Spin Goos-Haenchen effect of electron beams through a kind of MB nanostructures. Black-Right-Pointing-Pointer GH shift depends greatly on electron-spins, which is used to spin polarize electrons in semiconductor. Black-Right-Pointing-Pointer Spin polarization in GH shift is tunable. Black-Right-Pointing-Pointer A tunable spin beam splitter is achieved.

  19. AC Stark effect in ThO $H^3\\Delta_1$ for the electron EDM search

    CERN Document Server

    Petrov, A N

    2015-01-01

    A method and code for calculations of diatomic molecules in the external variable electromagnetic field have been developed. Code applied for calculation of systematics in the electron's electric dipole moment search experiment on ThO $H^3\\Delta_1$ state related to geometric phases, including dependence on $\\Omega$-doublet, rotational level, and external static electric field. It is found that systematics decrease cubically with respect to the frequency of the rotating transverse component of the electric field. Calculation confirms that experiment on ThO $H^3\\Delta_1$ state is very robust against systematic errors related to geometric phases.

  20. Comparative assessment of the vulnerability and resilience of 10 deltas : work document

    NARCIS (Netherlands)

    Bucx, T.; Marchand, M.; Makaske, B.; Guchte, van de C.

    2010-01-01

    Background information about: Nile delta (Egypt), Incomati delta (Mozambique), Ganges-Brahmaputra-Meghna (Bangladesh), Yangtze (China), Ciliwung (Indonesia), Mekong (Vietnam), Rhine-Meuse (The Netherlands), Danube (Romania), California Bay-Delta, Mississippi River Delta (USA)

  1. Learning Environment in Vietnamese Physics Teacher Education Programme through the Lens of Constructivism: A Case Study of a State University in Mekong Delta Region, Vietnam

    Science.gov (United States)

    Thao-Do, Thi Phuong; Bac-Ly, Dang Thi; Yuenyong, Chokchai

    2016-01-01

    Constructivism was introduced to Vietnam through many ways such as workshops, books, the Internet, and so on. However, due to the lack of professional education, fundamental ideas of constructivist learning perhaps were missing or neglected through classroom activities. Furthermore, due to the influence of culture and society, Vietnamese…

  2. Learning Environment in Vietnamese Physics Teacher Education Programme through the Lens of Constructivism: A Case Study of a State University in Mekong Delta Region, Vietnam

    Science.gov (United States)

    Thao-Do, Thi Phuong; Bac-Ly, Dang Thi; Yuenyong, Chokchai

    2016-01-01

    Constructivism was introduced to Vietnam through many ways such as workshops, books, the Internet, and so on. However, due to the lack of professional education, fundamental ideas of constructivist learning perhaps were missing or neglected through classroom activities. Furthermore, due to the influence of culture and society, Vietnamese…

  3. Prospects for Measuring $\\Delta$G from Jets at HERA with Polarized Protons and Electrons

    CERN Document Server

    Rädel, G; Feltesse, Joel; Kunne, Fabienne; Maul, M; Mirkes, E; Schäfer, A; Wu, C Y

    1996-01-01

    The measurement of the polarized gluon distribution function Delta G(x) from photon-gluon fusion processes in electron-proton deep inelastic scattering producing two jets has been investigated. The study is based on the MEPJET and PEPSI simulation programs. The size of the expected spin asymmetry and corresponding statistical uncertainties for a possible measurement with polarized beams of electrons and protons at HERA have been estimated. The results show that the asymmetry can reach a few percent, and is not washed out by hadronization and higher order processes.

  4. Prospects for measuring {Delta}G from jets at HERA with polarized protons and electrons

    Energy Technology Data Exchange (ETDEWEB)

    Roeck, A. de [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Feltesse, J. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de Physique des Particules, de Physique Nucleaire et de l`Instrumentation Associee (DAPNIA); Kunne, F. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de Physique des Particules, de Physique Nucleaire et de l`Instrumentation Associee (DAPNIA); Maul, M. [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Schaefer, A. [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Wu, C.Y. [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Mirkes, E. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Theoretische Teilchenphysik; Raedel, G. [European Organization for Nuclear Research, Geneva (Switzerland). Div. Particle Physics Experiments

    1996-09-01

    The measurement of the polarized gluon distribution function {Delta}G(x) from photon-gluon fusion processes in electron-proton deep inelastic scattering producing two jets has been investigated. The study is based on the MEPJET and PEPSI simulation programs. The size of the expected spin asymmetry and corresponding statistical uncertainties for a possible measurement with polarized beams of electrons and protons at HERA have been estimated. The results show that the asymmetry can reach a few percent, and is not washed out by hadronization and higher order processes. (orig.)

  5. Electron beam asymmetry measurements from exclusive pi0 electroproduction in the Delta(1232) resonance region

    Energy Technology Data Exchange (ETDEWEB)

    K. Joo

    2003-05-01

    The polarized longitudinal-transverse structure function sigma_LT'in the p(e,e'p)pi^0 reaction has been measured for the first time in the Delta(1232) resonance region for invariant mass W = 1.1 - 1.3 GeV and at four-momentum transfer Q^2 = 0.40 and 0.65 GeV^2. Data were taken at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at an energy of 1.515 GeV. This newly measured sigma_LT' provides new and unique information on the interference between resonant and non-resonant amplitudes in the Delta(1232) resonance region. The comparison to recent phenomenological calculations shows sensitivity to the description of non-resonant amplitudes and higher resonances.

  6. Electron beam asymmetry measurements from exclusive pi0 electroproduction in the Delta(1232) resonance region

    Energy Technology Data Exchange (ETDEWEB)

    K. Joo

    2003-05-01

    The polarized longitudinal-transverse structure function sigma_LT'in the p(e,e'p)pi^0 reaction has been measured for the first time in the Delta(1232) resonance region for invariant mass W = 1.1 - 1.3 GeV and at four-momentum transfer Q^2 = 0.40 and 0.65 GeV^2. Data were taken at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at an energy of 1.515 GeV. This newly measured sigma_LT' provides new and unique information on the interference between resonant and non-resonant amplitudes in the Delta(1232) resonance region. The comparison to recent phenomenological calculations shows sensitivity to the description of non-resonant amplitudes and higher resonances.

  7. Challenges, Approaches and Experiences from Asian Deltas and the Rhine-Meuse Delta : Regional Training Workshop on Delta Planning and Management

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2013-01-01

    River delta's, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Ayeyarwady Delta (Myanmar), Nile (Egypt) and Ciliwung Delta (Indonesia) are developing rapidly and are characterised by large-scale urbanisation and industrialization processes. They are facing serious planning ch

  8. Electronic and physico-chemical properties of nanometric boron delta-doped diamond structures

    Energy Technology Data Exchange (ETDEWEB)

    Chicot, G., E-mail: gauthier.chicot@neel.cnrs.fr; Fiori, A.; Tran Thi, T. N.; Bousquet, J.; Delahaye, J.; Grenet, T.; Eon, D.; Omnès, F.; Bustarret, E. [Université Grenoble Alpes, Institut NEEL, 38042 Grenoble (France); CNRS, Institut NEEL, 38042 Grenoble (France); Volpe, P. N.; Tranchant, N.; Mer-Calfati, C.; Arnault, J. C. [CEA, LIST, Diamond Sensors Laboratory, 91191 Gif-sur-Yvette (France); Gerbedoen, J. C.; Soltani, A.; De Jaeger, J. C. [IEMN, UMR-CNRS 8520, Avenue Poincaré, Université de Lille 1, 59652 Villeneuve d' Ascq (France); Alegre, M. P.; Piñero, J. C.; Araújo, D. [Dpto Ciencia de los Materiales, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real (Cádiz) (Spain); Jomard, F. [Groupe d' Étude de la Matière Condensée (GEMaC), UMR 8635 du CNRS, UVSQ, 45 Avenue des États-Unis, 78035 Versailles Cedex (France); and others

    2014-08-28

    Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called delta-doped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6 K < T < 450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.6 ± 0.8 cm{sup 2}/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.

  9. Electronic structure of delta-Pu and PuCoGa[sub 3] from photoemission and the mixed level model

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, J. J. (John Joseph); Wills, J. M. (John M.); Durakiewicz, T. (Tomasz); Butterfield, M. T. (Martin T.); Guziewicz, E. (Elzbieta); Sarrao, John L.,; Arko, A. J. (Aloysius J.); Moore, D. P. (David P.); Morales, L. A. (Luis A.); Eriksson, O. (Olle)

    2004-01-01

    The electronic structure of {delta}-phase Pu metal and the Pu-based superconductor PuCoGa{sub 5} is explored using photoelectron spectroscopy and a novel theoretical scheme. Excellent agreement between calculation and experiment defines a path forward for understanding electronic structure aspects of Pu-based materials. The photoemission results show two separate regions of 5f electron spectral intensity, one at the Fermi energy and another centered 1.2 eV below the Fermi level. A comparison is made between the photoemission data and five computational schemes for {delta}-Pu. The results for {delta}-Pu and PuCoGa{sub 5} indicate 5f electron behavior on the threshold between localized and itinerant and a broader framework for understanding the fundamental electronic properties of the Pu 5f levels in general within two configurations, one localized and one itinerant.

  10. A novel electronic configuration of the 5f states in {delta}-plutonium as revealed by the photo-electron spectra

    Energy Technology Data Exchange (ETDEWEB)

    Wills, J.M.; Eriksson, O. E-mail: olle.eriksson@fysik.uu.se; Delin, A.; Andersson, P.H.; Joyce, J.J.; Durakiewicz, T.; Butterfield, M.T.; Arko, A.J.; Moore, D.P.; Morales, L.A

    2004-04-01

    We present a theoretical model, the mixed-level model, aiming at describing metals with very complex, strongly correlated, electronic structures. As a demonstration, it is applied to the electronic structure of {delta}-Pu. The model reproduces the electronic-structure related properties of this complex metal; in particular, the theory is capable of reproducing the valence band photoemission spectrum of {delta}-Pu. We also report new experimental photoemission spectra at several photon energies. Taken together, our results provide strong evidence that the electronic structure of {delta}-Pu involves a 5f shell with four electrons in a localized multiplet hybridizing with valence states, and approximately one 5f electron forming a completely delocalized band state.

  11. Zeeman interaction in ThO $H^3\\Delta_1$ for the electron EDM search

    CERN Document Server

    Petrov, A N; Titov, A V; Hutzler, N R; Hess, P W; O'Leary, B R; Spaun, B; DeMille, D; Gabrielse, G; Doyle, J M

    2014-01-01

    The current limit on the electron's electric dipole moment, $|d_\\mathrm{e}|<8.7\\times 10^{-29} e {\\cdotp} {\\rm cm}$ (90% confidence), was set using the molecule thorium monoxide (ThO) in the $J=1$ rotational level of its $H ^3\\Delta_1$ electronic state [Science $\\bf 343$, 269 (2014)]. This state in ThO is very robust against systematic errors related to magnetic fields or geometric phases, due in part to its $\\Omega$-doublet structure. These systematics can be further suppressed by operating the experiment under conditions where the $g$-factor difference between the $\\Omega$-doublets is minimized. We consider the $g$-factors of the ThO $H^3\\Delta_1$ state both experimentally and theoretically, including dependence on $\\Omega$-doublets, rotational level, and external electric field. The calculated and measured values are in good agreement. We find that the $g$-factor difference between $\\Omega$-doublets is smaller in $J=2$ than in $J=1$, and reaches zero at an experimentally accessible electric field. This ...

  12. Spin-polarized electron tunneling across a Si delta-doped GaMnAs/n-GaAs interface

    DEFF Research Database (Denmark)

    Andresen, S.E.; Sørensen, B.S.; Lindelof, P.E.;

    2003-01-01

    Spin-polarized electron coupling across a Si delta-doped GaMnAs/n-GaAs interface was investigated. The injection of spin-polarized electrons was detected as circular polarized emission from a GaInAs/GaAs quantum well light emitting diode. The angular momentum selection rules were simplified...

  13. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing

    Directory of Open Access Journals (Sweden)

    Huyen Mai NT

    2013-02-01

    Full Text Available Abstract Background In comparison to restriction fragment length polymorphism (RFLP typing, variable number of tandem repeat (VNTR typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard in typing of Mycobacterium tuberculosis. However, some reports indicated that VNTR typing may be less suitable for Beijing genotype isolates. We therefore compared the performance of internationally standardized RFLP and 24 loci VNTR typing to discriminate among 100 Beijing genotype isolates from the Southern Vietnam. Methods Hundred Beijing genotype strains defined by spoligotyping were randomly selected and typed by RFLP and VNTR typing. The discriminatory power of VNTR and RFLP typing was compared using the Bionumerics software. Results Among 95 Beijing strains available for analysis, 14 clusters were identified comprising 34 strains and 61 unique profiles in 24 loci VNTR typing ((Hunter Gaston Discrimination Index (HGDI = 0.994. 13 clusters containing 31 strains and 64 unique patterns in RFLP typing (HGDI = 0.994 were found. Nine RFLP clusters were subdivided by VNTR typing and 12 VNTR clusters were split by RFLP. Five isolates (5% revealing double alleles or no signal in two or more loci in VNTR typing could not be analyzed. Conclusions Overall, 24 loci VNTR typing and RFLP typing had similar high-level of discrimination among 95 Beijing strains from Southern Vietnam. However, loci VNTR 154, VNTR 2461 and VNTR 3171 had hardly added any value to the level of discrimination.

  14. Vietnam Land Policy - Adjusting to Globalization

    Science.gov (United States)

    2013-11-01

    Conflicts over Land in Vietnam’s Red River Delta," Journal of Southeast Asian Studies, (2007): 317, accessed 6 September 2013, JSTOR . 5...Responsibility and No Rice,”: The Rise and Fall of Agricultural Collectivization in Vietnam,” Agricultural History: vol 82, no. 1, (2008), 54, JSTOR . 18...Performance and Communist Legitimacy,” World Politics, vol. 38 no. 3, (1986): 463, accessed 22 October 2013, JSTOR . 32 Ibid., 463. 33 Elliott

  15. Use of black carp (Mylopharyngodon piceus) in biological control of intermediate host snails of fish-borne zoonotic trematodes in nursery ponds in the Red River Delta, Vietnam

    DEFF Research Database (Denmark)

    Hung, Nguyen M.; Duc, Nguyen V.; Stauffer, Jay R.

    2013-01-01

    the first intermediate host (i.e., freshwater gastropods), would be an attractive approach, if feasible. The black carp, Mylopharyngodon piceus, is a well-known predator of freshwater snails and is already used successfully for biological control of snails in various parts of the world including Vietnam....... Here we report the first trials using it for biological control of intermediate host snails in nursery ponds stocked with 1-week old fry (10-12 mm in length) of Indian carp, Labeo rohita. Methods. Semi-field and field experiments were set up to test the effect of black carp on snail populations....... In the semi-field experiment a known quantity of snails was initially introduced into a pond which was subsequently stocked with black carp. In the field trial in nursery ponds, density of snails was estimated prior to a nursing cycle and at the end of the cycle (after 9 weeks). Results: The results showed...

  16. Correlation between HIV and sexual behavior, drug use, trichomoniasis and candidiasis among female sex workers in a Mekong Delta province of Vietnam.

    Science.gov (United States)

    Nguyen, Thuong Vu; Khuu, Nghia Van; Truong, Phong Hoai; Nguyen, Anh Phuong; Truong, Lien Xuan Thi; Detels, Roger

    2009-10-01

    To determine the prevalence of HIV and correlates of HIV infection among female sex workers (FSWs) in Soc Trang province, Vietnam, a survey of 406 FSWs in Soc Trang province was conducted between May and August, 2003. The participants were interviewed, using a standardized interview, to obtain information about socio-demographic and behavioral characteristics, and gynecologic and sexually transmitted infection (STI) history. The prevalence of HIV was 3.3%. An increased risk for HIV was associated with ever using illicit drugs, direct sex work, early sexual debut, age of FSWs, and infection with candidiasis and trichomoniasis. Reduced likelihood of HIV was only associated with withdrawal as a contraceptive method. A strong association of HIV with drug use and candidiasis and trichomoniasis infection among FSWs was found. Needle/syringe exchange, STI treatment, and methadone programs targeting FSWs should be implemented, and should include 100% condom use promotion.

  17. A Decision Tree Analysis to Support Potential Climate Change Adaptations of Striped Catfish (Pangasianodon hypophthalmus Sauvage) Farming in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, L.A.; Verreth, J.A.J.; Leemans, H.B.J.; Bosma, R.H.; Silva, De S.

    2016-01-01

    This study uses the decision tree framework to analyse possible climate change impact adaptation options for pangasius (Pangasianodon hypopthalmus Sauvage) farming in the Mekong Delta. Here we present the risks for impacts and the farmers' autonomous and planned public adaptation by using primary an

  18. A Decision Tree Analysis to Support Potential Climate Change Adaptations of Striped Catfish (Pangasianodon hypophthalmus Sauvage) Farming in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, L.A.; Verreth, J.A.J.; Leemans, H.B.J.; Bosma, R.H.; Silva, De S.

    2016-01-01

    This study uses the decision tree framework to analyse possible climate change impact adaptation options for pangasius (Pangasianodon hypopthalmus Sauvage) farming in the Mekong Delta. Here we present the risks for impacts and the farmers' autonomous and planned public adaptation by using primary

  19. Regional year-round sypply of vegetables in North Vietnam

    NARCIS (Netherlands)

    Everaarts, A.P.; Wijk, van M.S.; Pham Van Hoi,

    2008-01-01

    A discussion is presented about the patterns in the present year-round supply of vegetables to large cities in the Red River Delta in North Vietnam. Especially during the hot summer season, vegetables are supplied from Dalat in South Vietnam or from Kunming Province in China. Generally speaking, imp

  20. Massively parallel full configuration interaction. Benchmark electronic structure calculations on the Intel Touchstone Delta

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, R.J. [Argonne National Lab., IL (United States); Stahlberg, E.A. [Pacific Northwest Lab., Richland, WA (United States)

    1994-10-01

    We describe an implementation of the benchmark ab initio electronic structure full configuration interaction model on the Intel Touchstone Delta. Its performance is demonstrated with several calculations, the largest of which (95 million configurations, 418 million determinants) is the largest full-CI calculation yet completed. The feasibility of calculations with over one billion configurations is discussed. A sustained computation rate in excess of 4 GFLOP/s on 512 processors is achieved, with an average aggregate communication rate of 155 Mbytes/s. Data-compression techniques and a modified diagonalization method were required to minimize I/O. The object-oriented design has increased portability and provides the distinction between local and non-local data essential for use of a distributed-data model.

  1. Water metagenomic analysis reveals low bacterial diversity and the presence of antimicrobial residues and resistance genes in a river containing wastewater from backyard aquacultures in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nakayama, Tatsuya; Tuyet Hoa, Tran Thi; Harada, Kazuo; Warisaya, Minae; Asayama, Megumi; Hinenoya, Atsushi; Lee, Joon Won; Phu, Tran Minh; Ueda, Shuhei; Sumimura, Yoshinori; Hirata, Kazumasa; Phuong, Nguyen Thanh; Yamamoto, Yoshimasa

    2017-03-01

    The environmental pathways for the dissemination of antibiotic resistance have recently received increased attention. Aquatic environments act as reservoirs or sources of antimicrobial-resistant bacteria, antimicrobial residues, and antimicrobial resistance genes (ARGs). Therefore, it is imperative to identify the role of polluted water in the dissemination of antimicrobial resistance. The aim of this study was to evaluate the antimicrobial residues, ARGs, and microbiota in the freshwater systems of the Mekong Delta. We selected 12 freshwater sites from aquacultures and rivers in Can Tho, Vietnam and analyzed them for 45 antimicrobial residues and 8 ARGs by LC/MS/MS and real-time PCR, respectively. A 16S rDNA-based metagenomic analysis was conducted to characterize the water microbiota. Residues of sulfamethoxazole (10/12) and sulfadimidine (7/12) were widely detected, together with the sulfa-resistance genes sul1 (11/12) and sul2 (9/12). Additionally, sulfamethoxazole residues and the β-lactamase-resistance gene blaCTX-M-1 were detected in eight freshwater systems (8/12), suggesting that these freshwater systems may have been polluted by human activity. The metagenomic analysis showed that all the tested freshwater systems contained the phyla Proteobacteria, Actinobacteria, and Bacteroidetes, representing 64% of the total microbiota. Moreover, the Cai Rang River site (Ri-E), which is located at the merge point of wastewaters from backyard-based aquacultures, contained the genera Polynucleobacter, Variovorax, and Limnohabitans, representing more than 78.4% of the total microbiota. Bacterial diversity analysis showed that the Ri-E exhibited the lowest diversity compared with other regions. Principal coordinate analysis showed that the differences among water microbiotas in backyard-based aquacultures could be explained by the farmers' aquaculture techniques. In conclusion, this study demonstrated a collapse of bacterial diversity at the merge point of wastewaters

  2. Dynamics of Land Cover/Land Use Changes in the Mekong Delta, 1973–2011: A Remote Sensing Analysis of the Tran Van Thoi District, Ca Mau Province, Vietnam

    Directory of Open Access Journals (Sweden)

    Hanh Tran

    2015-03-01

    Full Text Available The main objective of this study is to assess the spatio-temporal dynamics of land cover/land use changes in the lower Mekong Delta over the last 40 years with the coastal Tran Van Thoi District of Ca Mau Province, Vietnam as a case study. Land cover/land use change dynamics are derived from moderate to high spatial resolution (Landsat and SPOT satellite imagery in six time intervals ranging from 1973 to 2011. Multi-temporal satellite images were collected, georeferenced, classified using per-pixel method, validated, and compared in post classification for the land use/land cover change detection in decades. Seven major land cover/land use classes were obtained, including cultivated lands, aquaculture ponds, mangrove forest, melaleuca forest, built up areas, bare lands, and natural water bodies. The accuracies of the land cover/land use maps for 1973, 1979, 1989, 1995, 2004, and 2011 were 81%, 82%, 86%, 87%, 89%, and 89%, respectively. The results show that the area of cultivated lands reduced over the period 1973–2011, however, it still represents the dominant land use in the case study. Aquaculture ponds were almost absent in 1973 but greatly increased from 1995 to 2004, to represent 20% of the land surface in 2011. Overall, from 1973 to 2011, bare lands, cultivated lands, mangrove forest, and melaleuca forest decreased by 104 km2, 77 km2, 61 km2, and 5 km2, respectively. In contrast, aquaculture lands and built up areas increased by 123 km2 and 120 km2, respectively. Temporal analysis highlights that these changes took place mostly between 1995 and 2004. This study is a first step to identify the main drivers of land use changes in this delta region, which include economical policies as well as demographic, socio-economic, and environmental changes.

  3. Effect of the hydrostatic pressure on the electron mobility in delta-doped systems

    Energy Technology Data Exchange (ETDEWEB)

    Oubram, O; Mora-Ramos, M E; Gaggero-Sager, L M, E-mail: 1gaggero@uaem.m [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico)

    2009-05-01

    The influence of hydrostatic pressure on the electron states and low-temperature mobility in n-type GaAs delta-doped single quantum wells is studied. Values of hydrostatic pressure consider are below the so-called GAMMA-X crossover, keeping all attention in the electronic properties at the Brillouin zone center. The effect of the pressure on the electron mobility is described via a relative quantity that is proportional to the ratio between P not = 0 and zero pressure results. Calculation is performed using an analytical description of the potential energy function profile, based on the Thomas-Fermi approach, taking explicitly into account the dependence upon P of the main input parameters: effective masses and dielectric constant. The relative mobility increases for higher values of P. The cases of zero and finite -although small- temperature are studied, showing that the influence of T is mainly to lower the values of the relative mobility in the entire range of P considered. Numerical results are reported for a two-dimensional density of ionized impurities equals to 7.5 x 10{sup 12} cm{sup -2}.

  4. Spatio-Temporal Occurrence Modeling of Highly Pathogenic Avian Influenza Subtype H5N1: A Case Study in the Red River Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Chinh C. Tran

    2013-11-01

    Full Text Available Highly Pathogenic Avian Influenza (HPAI subtype H5N1 poses severe threats to both animals and humans. Investigating where, when and why the disease occurs is important to help animal health authorities develop effective control policies. This study takes into account spatial and temporal occurrence of HPAI H5N1 in the Red River Delta of Vietnam. A two-stage procedure was used: (1 logistic regression modeling to identify and quantify factors influencing the occurrence of HPAI H5N1; and (2 a geostatistical approach to develop monthly predictive maps. The results demonstrated that higher average monthly temperatures and poultry density in combination with lower average monthly precipitation, humidity in low elevation areas, roughly from November to January and April to June, contribute to the higher occurrence of HPAI H5N1. Provinces near the Gulf of Tonkin, including Hai Phong, Hai Duong, Thai Binh, Nam Dinh and Ninh Binh are areas with higher probability of occurrence of HPAI H5N1.

  5. A hydrological model for interprovincial water resource planning and management: A case study in the Long Xuyen Quadrangle, Mekong Delta, Vietnam

    Science.gov (United States)

    Hanington, Peter; To, Quang Toan; Van, Pham Dang Tri; Doan, Ngoc Anh Vu; Kiem, Anthony S.

    2017-04-01

    In this paper we present the results of the development and calibration of a fine-scaled quasi-2D hydrodynamic model (IWRM-LXQ) for the Long Xuyen Quadrangle - an important interprovincial agricultural region in the Vietnamese Mekong Delta. We use the Long Xuyen Quadrangle as a case study to highlight the need for further investment in hydrodynamic modelling at scales relevant to the decisions facing water resource managers and planners in the Vietnamese Mekong Delta. The IWRM-LXQ was calibrated using existing data from a low flood year (2010) and high flood year (2011), including dry season and wet season flows. The model performed well in simulating low flood and high flood events in both dry and wet seasons where good spatial and temporal data exists. However, our study shows that there are data quality issues and key data gaps that need to be addressed before the model can be further refined, validated and then used for decision making. The development of the IWRM-LXQ is timely, as significant investments in land and water resource development and infrastructure are in planning for the Vietnamese Mekong Delta. In order to define the scope of such investments and their feasibility, models such as the IWRM-LXQ are an essential tool to provide objective assessment of investment options and build stakeholder consensus around potentially contentious development decisions.

  6. Electronic Structure of TIBa(sub 2)CaCu(sub 2)O(sub 7-delta)

    Science.gov (United States)

    Vasquez, R. P.; Novikov, D. L.; Freeman, A. J.; Siegal, M. P.

    1996-01-01

    The core levels of TIBa(sub 2)CaCu(sub 2)O(sub 7-delta) epitaxial films have been measured with x-ray photoelectron spectroscopy (XPS). The valence electronic structure has been determined using the full-potential linear muffin tin orbital band structure method and measured with XPS.

  7. Assessment of climate change impact on river flow regimes in The Red River Delta, Vietnam – A case study of the Nhue-Day River Basin

    Directory of Open Access Journals (Sweden)

    Phan Cao Duong

    2016-09-01

    Full Text Available Global warming has caused dramatic changes in regional climate variability, particularly regarding fluctuations in temperature and rainfall. Thus, it is predicted that river flow regimes will be altered accordingly. The purpose of this paper is to present the results of modeling such changes by simulating discharge using the HEC-HMS model. The precipitation was projected using super-high resolution multiple climate models (20 km resolution with newly updated emission scenarios as the input for the HEC-HMS model for flow analysis at the Red River Basin in the northern area of Vietnam. The findings showed that climate change impact on the river flow regimes tend towards a decrease in the dry season and a longer duration of flood flow. A slight runoff reduction is simulated for November while a considerable runoff increase is modeled for July and August amounting to 30% and 25%, respectively. The discharge scenarios serve as a basis for water managers to develop suitable adaptation methods and responses on the river basin scale.

  8. Electronic structure of p type Delta doped systems; Estructura electronica de sistemas dopadas con Delta de tipo p

    Energy Technology Data Exchange (ETDEWEB)

    Gaggero S, L.M.; Perez A, R. [Departamento de Fisica de los Materiales, Universidad Nacional de Educacion a Distancia, Senda del Rey s/n, 28040 Madrid (Spain)

    1998-12-31

    We summarize of the results obtained for the electronic structure of quantum wells that consist in an atomic layer doped with impurities of p type. The calculations are made within the frame worth of the wrapper function approach to independent bands and with potentials of Hartree. We study the cases reported experimentally (Be in GaAs and B in Si). We present the levels of energy, the wave functions and the rate of the electronic population between the different subbands, as well as the dependence of these magnitudes with the density of impurities in the layer. The participation of the bans of heavy holes is analysed, light and split-off band in the total electronic population. The effect of the temperature is discussed and we give a possible qualitative explanation of the experimental optical properties. (Author)

  9. Association between salinity and hospital admission for hypertension: an ecological case-control study in the Mekong Delta Region in Vietnam.

    Science.gov (United States)

    Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Chu, Cordia; Hieu Nguyen, Trung; Phung, Dung

    2017-04-13

    Drinking water in the Mekong Delta Region (MDR) is highly vulnerable to salinity intrusion and this problem is expected to increase with the projected climate change and sea level rise. Despite this, research on health effects of saline contaminated water is scarce in this region. This study examines the risk of hospital admission for hypertension in salinity-affected areas of the MDR. Cases and controls were obtained from national/provincial hospital admission records for 2013. The cases were adult patients whom hypertension (ICD10-code: I10-I15) was primary diagnosis for admission. Of the 13 provinces in the MDR, we identified seven as 'salinity exposed' and the remaining as 'non-exposed' areas. A multi-level logistic regression model was used to examine the association between salinity exposure and hypertension outcome. Of the total 573 650 hospital admissions, 22 382 (~3.9%) were hypertensive cases. The multi-level logistic model combining both individual and ecological factors showed a 9% increase in risk (95% CI: 3-14%) of hypertension admission among individuals in exposed areas compared to those in non-exposed areas. In order to develop and promote appropriate adaptation strategies, further research is recommended to identify the salt exposure pathways and consumption behaviours in the salinity exposed areas.

  10. Electronic structure of {alpha}- and {delta}-Pu from photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arko, A. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Joyce, J. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Morales, L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Wills, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lashley, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Wastin, F. [European Commission, Joint Research Centre, Institute for Transuranic Elements, P.O. Box 2340, D-76175 Karlsruhe, (Germany); Rebizant, J. [European Commission, Joint Research Centre, Institute for Transuranic Elements, P.O. Box 2340, D-76175 Karlsruhe, (Germany)

    2000-07-15

    We report photoemission results on {alpha}- and {delta}-Pu using a laser plasma light source (LPLS) as well as He light as the exciting radiation. The LPLS is a pseudocontinuum tunable light source with intensities rivaling some second-generation synchrotrons. Both phases of Pu display a narrow, temperature-independent, 5f-related feature at the Fermi energy, which is narrower in {delta}-Pu than in {alpha}-Pu, suggestive of possible heavy-fermion-like behavior. In both {alpha}-Pu and {delta}-Pu the photon-energy dependence of this feature suggests some 6d admixture, albeit somewhat smaller in {delta}-Pu. In this respect it differs qualitatively from Ce and U heavy fermions. (c) 2000 The American Physical Society.

  11. Dimensions of gender relations and reproductive health inequity perceived by female undergraduate students in the Mekong Delta of Vietnam: a qualitative exploration

    Directory of Open Access Journals (Sweden)

    Bui Thanh

    2012-10-01

    Full Text Available Abstract Introduction Increasing evidence indicates that gender equity has a significant influence on women’s health; yet few culturally specific indicators of gender relations exist which are applicable to health. This study explores dimensions of gender relations perceived by female undergraduate students in southern Vietnamese culture, and qualitatively examines how this perceived gender inequity may influence females’ sexual or reproductive health. Methods Sixty-two female undergraduate students from two universities participated in eight focus group discussions to talk about their perspectives regarding national and local gender equity issues. Results Although overall gender gaps in the Mekong Delta were perceived to have decreased in comparison to previous times, several specific dimensions of gender relations were emergent in students’ discussions. Perceived dimensions of gender relations were comparable to theoretical structures of the Theory of Gender and Power, and to findings from several reports describing the actual inferiority of women. Allocation of housework and social paid work represented salient dimensions of labor. The most salient dimension of power related to women in positions of authority. Salient dimensions of cathexis related to son preference, women’s vulnerability to blame or criticism, and double standards or expectations. Findings also suggested that gender inequity potentially influenced women’s sexual and reproductive health as regards to health information seeking, gynecological care access, contraceptive use responsibility, and child bearing. Conclusion Further investigations of the associations between gender relations and different women’s sexual and reproductive health outcomes in this region are needed. It may be important to address gender relations as a distal determinant in health interventions in order to promote gender-based equity in sexual and reproductive health.

  12. Dimensions of gender relations and reproductive health inequity perceived by female undergraduate students in the Mekong Delta of Vietnam: a qualitative exploration

    Science.gov (United States)

    2012-01-01

    Introduction Increasing evidence indicates that gender equity has a significant influence on women’s health; yet few culturally specific indicators of gender relations exist which are applicable to health. This study explores dimensions of gender relations perceived by female undergraduate students in southern Vietnamese culture, and qualitatively examines how this perceived gender inequity may influence females’ sexual or reproductive health. Methods Sixty-two female undergraduate students from two universities participated in eight focus group discussions to talk about their perspectives regarding national and local gender equity issues. Results Although overall gender gaps in the Mekong Delta were perceived to have decreased in comparison to previous times, several specific dimensions of gender relations were emergent in students’ discussions. Perceived dimensions of gender relations were comparable to theoretical structures of the Theory of Gender and Power, and to findings from several reports describing the actual inferiority of women. Allocation of housework and social paid work represented salient dimensions of labor. The most salient dimension of power related to women in positions of authority. Salient dimensions of cathexis related to son preference, women’s vulnerability to blame or criticism, and double standards or expectations. Findings also suggested that gender inequity potentially influenced women’s sexual and reproductive health as regards to health information seeking, gynecological care access, contraceptive use responsibility, and child bearing. Conclusion Further investigations of the associations between gender relations and different women’s sexual and reproductive health outcomes in this region are needed. It may be important to address gender relations as a distal determinant in health interventions in order to promote gender-based equity in sexual and reproductive health. PMID:23095733

  13. A climate-based prediction model in the high-risk clusters of the Mekong Delta region, Vietnam: towards improving dengue prevention and control.

    Science.gov (United States)

    Phung, Dung; Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Chu, Cordia

    2016-10-01

    To develop a prediction score scheme useful for prevention practitioners and authorities to implement dengue preparedness and controls in the Mekong Delta region (MDR). We applied a spatial scan statistic to identify high-risk dengue clusters in the MDR and used generalised linear-distributed lag models to examine climate-dengue associations using dengue case records and meteorological data from 2003 to 2013. The significant predictors were collapsed into categorical scales, and the β-coefficients of predictors were converted to prediction scores. The score scheme was validated for predicting dengue outbreaks using ROC analysis. The north-eastern MDR was identified as the high-risk cluster. A 1 °C increase in temperature at lag 1-4 and 5-8 weeks increased the dengue risk 11% (95% CI, 9-13) and 7% (95% CI, 6-8), respectively. A 1% rise in humidity increased dengue risk 0.9% (95% CI, 0.2-1.4) at lag 1-4 and 0.8% (95% CI, 0.2-1.4) at lag 5-8 weeks. Similarly, a 1-mm increase in rainfall increased dengue risk 0.1% (95% CI, 0.05-0.16) at lag 1-4 and 0.11% (95% CI, 0.07-0.16) at lag 5-8 weeks. The predicted scores performed with high accuracy in diagnosing the dengue outbreaks (96.3%). This study demonstrates the potential usefulness of a dengue prediction score scheme derived from complex statistical models for high-risk dengue clusters. We recommend a further study to examine the possibility of incorporating such a score scheme into the dengue early warning system in similar climate settings. © 2016 John Wiley & Sons Ltd.

  14. Electronic transport measurements in the electron-doped high-temperature superconductor Praseodymium(2-x) Cerium(x) Copper (II) oxide(4+-delta)

    Science.gov (United States)

    Bach, Paul Leonard

    2011-12-01

    This thesis is composed of four major parts centered around the electron-doped superconductor Pr2-xCexCuO4+/-delta: angular magnetoresistance studies of antiferromagnetism, doping effects of oxygenation, Tc enhancement by the creation of superlattices, and comparison of high-temperature resistivity with the pnictides. The first part focuses on transport measurements of the magnetism in Pr2-xCexCuO4+/-delta and La 2-xCexCuO4+/-delta. It was found that the thermal evolution of the angular dependence of magnetoresistance in Pr 2-xCexCuO4+/-delta can be used to determine the Neel temperature in that material. This angular magnetoresistance technique was also applied to La2-xCexCuO4+/-delta ; evidence for antiferromagnetism in this system was observed as well. This section additionally develops angular magnetoresistance as a useful probe in other cuprate projects here described. The second part investigates over-oxygenated and irradiated Pr2-x CexCuO4+/-delta, in under- and optimal dopings. Resistivity, Hall effect, and angular magnetoresistance measurements show oxygen both doping and disordering the system, in agreement with over-doped films. The evolution of both the Hall effect and angular magnetoresistance shows that over-oxygenation results in significant changes in the number of charge carriers, regardless of the increase in scattering incurred. Additionally, this study indicates that annealing primarily removes apical oxygen, rather than other proposed behaviors. The third part studies multi-layer films of Pr2-xCex CuO4+/-delta and La2-xCexCuO 4+/-delta. These superlattices exhibit a significant Tc enhancement over component layers' T cs. Interface effects are excluded as a source of this Tc increase based upon critical current measurments. The Tc enhancement is found to be due to charge redistribution. Based on Hall and angular magnetoresistance measurements, the result of this redistribution is slightly net-under-doped films. The fourth part uses Pr2-xCexCuO4

  15. Comment on "Theoretical study of thorium monoxide for the electron electric dipole moment search: Electronic properties of ${H}^3\\Delta_1$ in ThO"

    CERN Document Server

    Denis, Malika

    2016-01-01

    We present an updated EDM effective electric field of $E_{\\text{eff}} = 75.2\\left[\\frac{\\rm GV}{\\rm cm}\\right]$ and the electron-nucleon scalar-pseudoscalar interaction constant $W_S=107.8$ [kHz] for the ${^3\\Delta}_1$ science state of ThO. The criticisms made in reference [J. Chem. Phys. 142, 024301 (2015)] are addressed and largely found to be unsubstantiated within the framework of our approach.

  16. Performance evaluation of partial differential equation models in electronic speckle pattern interferometry and the delta-mollification phase map method.

    Science.gov (United States)

    Tang, Chen; Zhang, Fang; Li, Botao; Yan, Haiqing

    2006-10-01

    The ordinary differential equation (ODE) and partial differential equation (PDE) image- processing methods have been applied to reduce noise and enhance the contrast of electronic speckle pattern interferometry fringe patterns. We evaluate the performance of a few representative PDE denoising models quantitatively with two parameters called image fidelity and speckle index, and then we choose a good denoising model. Combining this denoising model with the ODE enhancement method, we make it possible to perform contrast enhancement and denoising simultaneously. Second, we introduce the delta-mollification method to smooth the unwrapped phase map. Finally, based on PDE image processing, delta mollification and some traditional techniques, an approach of phase extraction from a single fringe pattern is tested for computer-simulated and experimentally obtained fringe patterns. The method works well under a high noise level and limited visibility and can extract accurate phase values.

  17. Deep Impact Delta II Launch Vehicle Cracked Thick Film Coating on Electronic Packages Technical Consultation Report

    Science.gov (United States)

    Cameron, Kenneth D.; Kichak, Robert A.; Piascik, Robert S.; Leidecker, Henning W.; Wilson, Timmy R.

    2009-01-01

    The Deep Impact spacecraft was launched on a Boeing Delta II rocket from Cape Canaveral Air Force Station (CCAFS) on January 12, 2005. Prior to the launch, the Director of the Office of Safety and Mission Assurance (OS&MA) requested the NASA Engineering and Safety Center (NESC) lead a team to render an independent opinion on the rationale for flight and the risk code assignments for the hazard of cracked Thick Film Assemblies (TFAs) in the E-packages of the Delta II launch vehicle for the Deep Impact Mission. The results of the evaluation are contained in this report.

  18. Bilayer splitting in the electronic structure of heavily overdoped Bi(2)Sr(2)CaCu(2)O(8+delta).

    Science.gov (United States)

    Feng, D L; Armitage, N P; Lu, D H; Damascelli, A; Hu, J P; Bogdanov, P; Lanzara, A; Ronning, F; Shen, K M; Eisaki, H; Kim, C; Shen, Z X; Shimoyama, J; Kishio, K

    2001-06-11

    The electronic structure of heavily overdoped Bi(2)Sr(2)CaCu(2)O(8+delta) is investigated by angle-resolved photoemission spectroscopy. The long-sought bilayer band splitting in this two-plane system is observed in both normal and superconducting states, which qualitatively agrees with the bilayer Hubbard model calculations. The maximum bilayer energy splitting is about 88 meV for the normal state feature, while it is only about 20 meV for the superconducting peak.

  19. Réformes, croissance, et augmentation des inégalités dans le delta du fleuve Rouge – Việt Nam (1980-2000 Reform, Growth and Increase of Inequalities in the Red River delta - Vietnam (1980-2000

    Directory of Open Access Journals (Sweden)

    Christophe Gironde

    2009-10-01

    Full Text Available Cet article est une analyse de l’évolution des inégalités dans les campagnes vietnamiennes, basée sur une recherche de terrain dans le delta du fleuve Rouge. Les transformations respectives des systêmes d’activités productives des foyers étudiées dans la province de Hưng Yên remettent en cause l’idée dominante selon laquelle l’augmentation des inégalités serait faible et récent. L’accumulation réalisée par un quart des exploitations et la prolétarisation partielle d’une majorité de la population rurale révèlent, quelques années après la distribution des terres de 1994, une différenciation significative en termes de richesses et d’accès aux ressources. Les mécanismes de cette différenciation se sont mis en place dès les premières mesures de la décollectivisation de l’agriculture au tournant des années 1970-1980, contrairement à une autre idée courante selon laquelle les réformes n’auraient pas eu d’effet sur les inégalités à l’intérieur des campagnes. Les inégalités de départ augmentent avec la croissance, et sont aggravées par les orientations du gouvernement, et notamment l’action des pouvoirs locaux.Based on a field research in the Red River delta, this article analyses the augmentation and accentuation of inequalities within rural Vietnam. The various changes of livelihood systems in Hung Yen province challenge the mainstream idea whereby inequalities have increased only slightly and are of recent date. In the second half of the 1990s, the widening gap between wealth accumulation among one fourth of households, and the gradual proletarianization of a majority of the rural population is already significant. Contrary to another common idea whereby institutional reforms have been associated with almost no change in inequality within rural areas, I argue that the mechanisms inciting this differentiation were set in motion during the implementation of the first decollectivisation

  20. Multiplet effects in the electronic structure of {delta}-Pu, Am and their compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shick, A.; Kolorenc, J.; Drchal, V. [Institut of Physics, ASCR, Prague (Czech Republic); Kolorenc, J. [North Carolina State Univ., Dept. of Physics, Raleigh, NC (United States); Havela, L. [Charles Univ. Dept. of Condensed Matter Physics, Faculty of Mathematics and Physics, Prague (Czech Republic); Gouder, T. [Joint Research Centre, Institute for Transuranium Elements, European Commission, Karlsruhe (Germany)

    2007-01-15

    We propose a straightforward and efficient procedure to perform dynamical mean-field (DMFT) calculations on the top of the static mean-field LDA+U (local density approximation) approximation. Starting from self-consistent LDA+U ground state we included multiplet transitions using the Hubbard-I approximation, which yields a very good agreement with experimental photoelectron spectra of {delta}-Pu, Am, and their selected compounds. (authors)

  1. DEVELOPMENT ELECTRONIC MAPS OF ECOLOGICAL STATUS OF WATER OBJECTS OF THE VOLGA RIVER DELTA

    Directory of Open Access Journals (Sweden)

    Z. N. Isenalieva

    2016-01-01

    Full Text Available Abstract. Aim. The aim of this work was the comprehensive study of the ecological state of water objects of the Volga River delta. Methods. The following methods were used: field (collection, observation, organoleptic, uniform chemical analysis techniques are based on colorimetric, settlement, photometric, spectrometric measurement methods. Results. On the basis of results of researches for 2010-2014 performed a comparative analysis of the dynamics of the content of hydro-chemical indicators of environmental quality in waters of the Volga River delta and the residential areas of the background. Applying an integrated approach to the study of biological indicators of water quality. Created digitized map of the quality of aquatic ecosystems of the Volga River delta. Displaying modern ecological condition of watercourses investigated, determined the degree of contamination, the overall trophic and saprobic. Main conclusions. The work has identified adverse environmental situation in water objects of the Astrakhan and the surrounding areas. Average annual concentrations of toxicological substances water objects in the background zone 10 times less than in the water objects of settlements. As a result of work on the basis of ArcGis 10.2.2 created information environment "Eco-monitor", which is a systematic set of information, and quantitatively characterizing the ecological status of water objects. Created on the basis of ArcGis 10.2.2 information environment monitoring system of waterways allows for a temporary and spatial analysis, to assess the quality of different streams in the control sections.

  2. Vietnam: Historians at War

    Science.gov (United States)

    Moyar, Mark

    2008-01-01

    Although the Vietnam War ended more than thirty years ago, historians remain as divided on what happened as the American people were during the war. Mark Moyar maps the ongoing battle between "orthodox" and "revisionist" Vietnam War historians: the first group, those who depict Vietnam as a bad war that the United States should…

  3. Vietnam: Historians at War

    Science.gov (United States)

    Moyar, Mark

    2008-01-01

    Although the Vietnam War ended more than thirty years ago, historians remain as divided on what happened as the American people were during the war. Mark Moyar maps the ongoing battle between "orthodox" and "revisionist" Vietnam War historians: the first group, those who depict Vietnam as a bad war that the United States should…

  4. Investigation of transient processes at the DELTA electron storage ring using a digital bunch-by-bunch feedback system

    Energy Technology Data Exchange (ETDEWEB)

    Hoener, Markus

    2015-07-01

    At the 1.5-GeV synchrotron radiation source DELTA, operated by the TU Dortmund University, intensive synchrotron radiation in the spectral range from hard X-rays to THz radiation is generated by the circular deflection of highly relativistic electron bunches. Interacting with the vacuum chamber wall, the electron bunches create electric fields, which can act back on subsequent bunches. With increasing beam current, the excitation is enhanced so that the electron beam is unstable, which means that the electron bunches oscillate longitudinally or transversely relative to their reference position. The oscillations reduce the quality of the synchrotron radiation and limit the maximum storable beam current. Within the scope of this thesis, the beam instabilities at the storage ring were systematically investigated. A digital bunch-by-bunch feedback system was installed and commissioned, which allows to detect and digitize the position of each electron bunch at each turn. Based on the input signal, a correction signal is calculated in order to suppress transverse and longitudinal oscillation of the bunches. In addition, it is possible to excite dedicated bunches. The systematic excitation of all coupled-bunch modes allowed for the first time to determine the damping rates of all 192 eigenmodes of the electron beam. The current dependence of the damping rates was investigated and an instability threshold was found. Besides the investigation of multibunch instabilities, single-bunch instabilities are discussed. In addition, the acquisition unit of the digital feedback system can be triggered on external events. This was used to investigate the injection process and beam losses. It was shown that the transverse feedback system increases the injection efficiency. Another aspect of this thesis is the improvement of the signal quality of ultrashort coherent synchrotron radiation pulses, which are generated by the short-pulse facility at DELTA. The short-pulse facility is based

  5. Vietnam and the sustainable development of the Mekong river basis.

    Science.gov (United States)

    Quang, Nguyen Nhan

    2002-01-01

    Vietnam is a riparian country located in most downstream area of the Mekong river basin which is also shared by other states namely China, Myanmar, Laos, Thailand and Cambodia. While the Central Highlands of Vietnam has a great potential for hydropower development in tributaries of Mekong river, the Mekong delta in Vietnam territory is rich in natural resources which are favorable for agricultural development. However, besides local constraints which being gradually remedied by Vietnam, the development of the Mekong delta is subject to, in both terms of quantity and quality, availability of water resources which relates to the water use of or discharge into the river of upper riparians. With a view to co-developing these resources in a sustainable and mutually beneficial manner, Vietnam has cooperated with other states through framework of the Mekong River Commission set up by the 1995 Mekong Agreement. This paper describes the strategy and action plan applied by Viet Nam National Mekong Committee to reach the sustainable development of the Mekong river basin in general and of Vietnam parts located in the Mekong basin in particular.

  6. Estimation of the Unregistered Inflow of Electrical and Electronic Equipment to a Domestic Market: A Case Study on Televisions in Vietnam.

    Science.gov (United States)

    Tran, Ha Phuong; Wang, Feng; Dewulf, Jo; Huynh, Trung-Hai; Schaubroeck, Thomas

    2016-03-01

    Waste electrical and electronic equipment (WEEE) constitutes one of the most problematic waste streams worldwide, and accurately estimating the scale of WEEE can assist in tackling its associated issues. However, obtaining an accurate estimation of WEEE remains a challenge because a share of the waste is difficult to calculate. This share stems from the administratively unregistered (so-called "invisible") inflow of electrical and electronic equipment (EEE) into the domestic market. As a first attempt to qualitatively and quantitatively investigate this invisible inflow, this study discusses the nature of this flow in detail and proposes a calculation pathway for quantifying its magnitude. The size of the invisible inflow to a domestic market (assumed equal to invisible sales) is calculated by subtracting the registered, also called "visible", sales from the total sales. The total sales are modeled, whereas the visible sales are derived from statistical data. The method is illustrated by a case study on televisions (TVs) in Vietnam. The results show that from 2002 to 2013, the invisible TV inflow contributed, on average, 15% to the total TV sales (coefficient of variation: 0.21). This average share would increase by approximately 1.0% when the maximum number of TVs used per household increased by 1.0%. However, it would decrease by 1.7% when the visible sales increased by 1.0%. Additionally, the average share of the invisible TV inflow would change from 15% to 27% when an unadjusted constant instead of an adjusted time-varying lifespan is employed. This first estimation of the invisible EEE inflow to the domestic market can be improved with additional knowledge and data in the future.

  7. Ocean Dynamics: Vietnam DRI

    Science.gov (United States)

    2014-09-30

    Dynamics: Vietnam DRI Robert Pinkel Marine Physical Laboratory Scripps Institution of Oceanography La Jolla California 92093-0213 Phone: (858) 534...DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Ocean Dynamics: Vietnam DRI 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...cycle.. The Thorpe-scale estimates are local to Site III. South China Sea Process Cruise 2014 Under Vietnam DRI funding, Researcher Drew Lucas

  8. Capacity Building in Vietnam

    OpenAIRE

    Adam McCarty

    2001-01-01

    This report is the outcome of a study commissioned to examine the capacity building needs in Vietnam, and is a supplementary document to the Asian Development Bank's Country Operational Strategy for Vietnam. Vietnam's needs in terms of capacity building are particularly important given that is it a transitional economy and also one with little institutional experience in dealing with the international donor community. This paper examines the international awareness of capacity building and ca...

  9. DELTAS: A new Global Delta Sustainability Initiative (Invited)

    Science.gov (United States)

    Foufoula-Georgiou, E.

    2013-12-01

    , Vietnam, and Canada. Key components of the DELTAS Sustainability Initiative are: integrated research on deltas as coupled socio-ecological systems undergoing change (Delta-SRES), a global delta data depository (Delta-DAT), a suite of open access delta risk assessment and decision support modeling tools (Delta-RADS), and the coordinated demonstration of these activities in deltas around the world (Delta-ACT).

  10. EU and Vietnam

    DEFF Research Database (Denmark)

    Kokko, Ari

    was limited to aid. The reason is largely Vietnam’s historical experiences from the aid relationship with the Soviet Union, which created dependence and eventually an economic crisis when aid flows dried up in the late 1980s. Instead, there has been substantial tension between the donor community and Vietnam...... towards Vietnam. However, it is likely that the antidumping measures used by the EU are not primarily directed at Vietnam, but rather at China. This means that Vietnam is affected by the re-polarization of the world economy through its proximity to and links with China, but that the relation is perhaps...

  11. Mangrove restoration in Vietnam: Key considerations and a practical guide

    NARCIS (Netherlands)

    Marchand, M.

    2008-01-01

    In Vietnam mangrove rehabilitation has a long history and gained momentum after the war that destroyed huge forested areas, especially in the Mekong Delta. In addition, in various places mangrove have been and still are being planted specifically as a way to protect shorelines and sea-dykes from wav

  12. Integrated Coastal Management in the Province Ca Mau - Vietnam

    NARCIS (Netherlands)

    Stoop, B.; Bouziotas, D.; Hanssen, J.L.J.; Dunnewolt, J.; Postma, M.G.

    2015-01-01

    The province of Ca Mau is the southernmost part of Vietnam and the Mekong Delta. The water system of Ca Mau faces multiple challenges, both in its coastal zone and in its inland regions. the coastal zone in the province. In view of this, this study presents an integrated approach for combined coasta

  13. Magnetic state of f electrons in {delta}-phase of Pu-Ga alloys studied by Ga NMR

    Energy Technology Data Exchange (ETDEWEB)

    Verkhovskii, S. [Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Kovalevskaya Str. 18, 620041 Ekaterinburg (Russian Federation); Piskunov, Yu. [Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Kovalevskaya Str. 18, 620041 Ekaterinburg (Russian Federation)], E-mail: piskunov@imp.uran.ru; Mikhalev, K.; Buzlukov, A.; Arkhipov, V. [Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Kovalevskaya Str. 18, 620041 Ekaterinburg (Russian Federation); Zouev, Yu. [RFNC-VNII Technical Physics named after acad. E.I. Zababakhin, Snezhinsk (Russian Federation); Korolev, A. [Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Kovalevskaya Str. 18, 620041 Ekaterinburg (Russian Federation); Lekomtsev, S.; Svyatov, I. [RFNC-VNII Technical Physics named after acad. E.I. Zababakhin, Snezhinsk (Russian Federation); Pogudin, A.; Ogloblichev, V. [Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Kovalevskaya Str. 18, 620041 Ekaterinburg (Russian Federation)

    2007-10-11

    {sup 69}Ga nuclear magnetic resonance (NMR) line shift ({sup 69}K) and nuclear spin-lattice relaxation rate ({sup 69}T{sub 1}{sup -1}) are measured for Pu{sub 0.95}Ga{sub 0.05} alloy, stabilized in {delta}-phase, in the temperature range 10 and 650 K at magnetic field of 9.4 T. The shift and {sup 69}T{sub 1}{sup -1} are determined correspondingly by the static and fluctuating-in-time parts of the local magnetic fields arisen at Ga due to transferred hyperfine coupling with the nearest f electron environment of more magnetic Pu. At T > 200 K, the temperature dependent part of the shift {sup 69}K(T) scales macroscopic magnetic susceptibility {chi}(T), following the Curie-Weiss law, and the product ({sup 69}T{sub 1}T) increases with temperature proportionally (T + 255){sup 1.5(1)}. Both of the NMR observations are typical of the incoherent spin fluctuation regime of f electrons in nonmagnetic 3D Kondo lattice. An estimate of the effective magnetic moment {mu}{sub eff,5f}(g{sub e} = 2) = 0.15(5){mu}{sub B} per Pu atom points out a strong suppression of the spin magnetism in the alloy.

  14. Reaction of protonated tyrosine with electronically excited singlet molecular oxygen (a1Delta(g)): an experimental and trajectory study.

    Science.gov (United States)

    Fang, Yigang; Liu, Jianbo

    2009-10-22

    Reaction of protonated tyrosine with the lowest electronically excited singlet state of molecular oxygen, (1)O(2) (a(1)Delta(g)), is reported over the center-of-mass collision energy (E(col)) range from 0.1 to 3.0 eV, using an electrospray-ionization, guided-ion-beam scattering instrument, in conjunction with ab initio electronic structure calculations and direct dynamics trajectory simulations. Only one product channel is observed, corresponding to generation of hydrogen peroxide via transfer of two hydrogen atoms from protonated tyrosine. Despite being exoergic, the reaction is in competition with physical quenching of (1)O(2) and is very inefficient. At low E(col), the reaction may be mediated by intermediate complexes and shows strong inhibition by collision energy. At high E(col), the reaction efficiency drops to approximately 1% and starts to have contribution from a direct mechanism. Quasi-classical trajectory simulations were performed to probe the mechanism at high collision energies. Analysis of trajectories shows that, at E(col) of 3.0 eV, a small fraction of hydrogen peroxide (25%) is produced via a direct, concerted mechanism where two hydrogen atoms are transferred simultaneously, but most hydrogen peroxide (75%) is formed by dissociation of hydroperoxide intermediates. According to ab initio calculations and trajectory simulations, collisions also lead to formation of various endoperoxides, and dissociation of endoperoxides may play a role in physical quenching of (1)O(2). The apparatus and experimental techniques are described in detail.

  15. Effect of two intermediate electron donors, NADPH and FADH(2), on Spirulina Delta (6)-desaturase co-expressed with two different immediate electron donors, cytochrome b (5) and ferredoxin, in Escherichia coli.

    Science.gov (United States)

    Kurdrid, Pavinee; Subudhi, Sanjukta; Cheevadhanarak, Supapon; Tanticharoen, Morakot; Hongsthong, Apiradee

    2007-12-01

    When the gene desD encoding Spirulina Delta(6)-desaturase was heterologously expressed in E. coli, the enzyme was expressed without the ability to function. However, when this enzyme was co-expressed with an immediate electron donor, i.e. the cytochrome b (5) domain from Mucor rouxii, the results showed the production of GLA (gamma-linolenic acid), the product of the reaction catalyzed by Delta(6)-desaturase. The results revealed that in E. coli cells, where cytochrome b (5) is absent and ferredoxin, a natural electron donor of Delta(6)-desaturase, is present at a very low level, the cytochrome b (5) domain can complement for the function of ferredoxin in the host cells. In the present study, the Spirulina-ferredoxin gene was cloned and co-expressed with the Delta(6)-desaturase in E. coli. In comparison to the co-expression of cytochrome b ( 5 ) with the Delta(6)-desaturase, the co-expression with ferredoxin did not cause any differences in the GLA level. Moreover, the cultures containing the Delta(6)-desaturase co-expressed with cytochrome b (5) and ferredoxin were exogenously supplied with the intermediate electron donors, NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) and FADH(2) (flavin adenine dinucleotide, reduced form), respectively. The GLA level in these host cells increased drastically, by approximately 50%, compared to the cells without the intermediate electron donors. The data indicated that besides the level of immediate electron donors, the level of intermediate electron donors is also critical for GLA production. Therefore, if the pools of the immediate and intermediate electron donors in the cells are manipulated, the GLA production in the heterologous host will be affected.

  16. Theoretical study of thorium monoxide for the electron electric dipole moment search, II: Electronic properties of $H^3\\Delta_1$ in ThO

    CERN Document Server

    Skripnikov, L V

    2014-01-01

    Recently an improved limits on the electron electric dipole moment, \\eEDM, and dimensionless constant, $k_{T,P}$, characterizing the strength of the T,P-odd pseudoscalar$-$scalar electron$-$nucleus neutral current interaction in the $H^3\\Delta_1$ state of ThO molecule were obtained by ACME collaboration [Science 343, 269 (2014)]. The interpretation of the experiment in terms of fundamental quantities \\eEDM\\ and $k_{T,P}$ is based on the results of theoretical study of appropriate ThO characteristics, the effective electric field acting on electron, \\Eeff, and a parameter of the T,P-odd pseudoscalar$-$scalar interaction, $W_{T,P}$, given in [J.Chem.Phys.\\ 139, 221103 (2013)] by St.Petersburg group. To reduce the uncertainties of the given limits we report improved calculations of the molecular state$-$specific quantities \\Eeff, 81.5~GV/cm, and $W_{T,P}$, 112~kHz, with the uncertainty within 7\\% of the magnitudes. Thus, the values recommended to use for the upper limits of the quantities are 75.8~GV/cm and 104~...

  17. Doing Business in Vietnam

    DEFF Research Database (Denmark)

    Meyer, Klaus E.; Tran, Thi Thu Yen; Nguyen, Hung Vo

    2005-01-01

    still reflects inheritances from the central plan system, Vietnam today has a vibrant economy with small businesses springing up at every street corner. Foreign investors have been flogging to Vietnam since the early 1990s, with a new peak of FDI inflow in 2004. This paper reviews the Vietnamese economy...

  18. Southern Vietnam since 1975.

    Science.gov (United States)

    Dat, Bao

    1995-01-01

    Discusses social and political changes in southern Vietnam since the end of the Vietnam War. Describes anti-U.S. propaganda used in the schools and media in the years immediately following the war. Contends that younger Vietnamese look forward to a closer relationship with the United States and its people. (CFR)

  19. Climate Change and Vietnam

    Science.gov (United States)

    2013-11-01

    expansion of large hydropower and reservoir construction can increase social resilience through associated economic development . However, the same...of the most vulnerable countries globally to the consequences of climate change, Vietnam is highly likely to experience a variety of negative...iii ABSTRACT Climate Change and Vietnam As one of the most vulnerable countries globally to the consequences

  20. Emergency medicine in Vietnam.

    Science.gov (United States)

    Richards, J R

    1997-04-01

    The Socialist Republic of Vietnam is one of the poorest countries in the world. Recent economic developments, as the country attempts to start a market economy, have had a profound impact on its health care system. This report describes the state of prehospital and emergency medical care in Vietnam and possibilities for the future.

  1. Challenges and Approaches in River Delta Planning - report on training workshop

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2012-01-01

    River delta’s, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Irrawady (Myanmar) and Ciliwung Delta (Indonesia) are developing rapidly and characterized by large-scale urbanization and industrialization processes. They are facing serious planning challenges related to issues

  2. Lifetime improvement and beam stabilization by longitudinal phase modulation at the DELTA electron storage ring; Lebensdauerverbesserung und Strahlstabilisierung durch longitudinale Phasenmodulation am Elektronenspreicherring DELTA

    Energy Technology Data Exchange (ETDEWEB)

    Fuersch, Jonathan

    2014-10-16

    In DELTA especially at high beam currents often the occurence of an instability of a longitudinal oscillation mode is observed. In the framework of the present thesis first with different procedure the cause of the longitudinal oscillation mode, which is especially strongly excited at high beam currents, is searched for. Thereby connections between the occurrence of this mode and parameters from the region of the storage-ring high-frequency system is observed. It is shown by comparison of different procedures, simulation calculations, and experimental pre-examinations, that especially by a phase modulation of the storage-ring high frequency an essential improvement of especially the longitudinal beam stability and the beam lifetime can be reached. For the durable and reliable improvement of these beam properties in the framework of the present thesis a system for the longitudinal phase modulation of the after-acceleration voltage in the cavity resonator of the DELTA storage ring is concipated, developed, constructed, taken in operation, and tested. Finally the results aimed hereby are presented and discussed.

  3. Electronic structure and the van Hove singularity scenario in high-T(sub c)H(g)Ba2CuO(4+delta) superconductors

    Science.gov (United States)

    Agrawal, Bal K.; Agrawal, Savitri

    1995-01-01

    The electronic structure and the hole concentrations in the high Tc superconductor HgBa2CuO(4+delta) (delta = O, 1) has been investigated by employing a first principles full potential self-consistent LMTO method with the local density functional theory. The scalar relativistic effects have been considered. The hole concentrations of the Cu-d and O-p(x,y) orbitals are seen to be larger for the HgBaCuO5 system than those of the HgBaCuO4 solid. However, the van Hove singularity (vHs) induced Cu-d and O-p peak which is seen to lie comparatively away and above the Fermi level in the delta = 1 system shifts towards the Fermi level in the delta = 0 system. Thus, the superconducting behavior appears to originate from the occurrence of the vHs peak at the Fermi level. The Fermi surface nesting area in the delta = 0 compound is seen to be larger than in the delta = 1 compound. The calculation reveals that the increase in pressure on the crystal enhances the hole concentrations but without showing any optimum value, On the other hand, the vHs peak approaches to-wards the Fermi level with pressure and crosses the Fermi surface near V/Vo approximately equals 0.625 (V and Vo are the crystal volumes at high and normal pressures, respectively). Our calculated value of the bulk modulus equal to 0.626 Mbar predicts the occurrence of this crossover at about 24 GPa which is in complete agreement with the experimental value. At this pressure the compound has maximum nesting area and self-doped behavior.

  4. Electronic Raman scattering in heavily overdoped (Y,Ca)Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Limonov, M.; Masui, T.; Uchiyama, H.; Lee, S.; Tajima, S.; Yamanaka, A

    2003-10-15

    In order to get insight into the overdoped electronic state, Raman scattering in heavily overdoped detwinned (Y,Ca)Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} crystals (T{sub c}=65 K) has been investigated. In the A{sub 1g} and B{sub 1g} polarizations, the electronic pair-breaking peak is located at nearly the same energy of about 220 cm{sup -1}, in contrast to the polarization dependent position of the peak in optimally doped YBa{sub 2}Cu{sub 3} O{sub 7-{delta}} crystals. The result is in favor of d + s-pairing symmetry in this overdoped material. The spectra also show the strong superconductivity induced XY-anisotropy in intensity of the pair-breaking peak, which indicates the existence of quantum interference between CuO{sub 2} planes and CuO-chains in this compound.

  5. Low-temperature electronic transport measurements on a gated delta -doped GaAs sample: magnetoresistance, quantum Hall effect and conductivity fluctuations

    OpenAIRE

    Dötzer, R.; Friedland, K. J.; Hey, R.; Kostial, H; Miehling, H.; Schoepe, Wilfried

    1994-01-01

    We present magnetotransport measurements (up to 7 T) performed at very low temperatures (down to 20 mK) on a GaAs sample containing two parallel delta -doped layers whose carrier concentration can be varied by means of a gate electrode. With increasing negative gate voltage the resistance becomes more strongly temperature-dependent, indicating a more localized electron system. The magnetoresistance is found to be strongly anisotropic. When the field is parallel to the layers we find a large p...

  6. Doing Business in Vietnam

    DEFF Research Database (Denmark)

    Meyer, Klaus E.; Tran, Thi Thu Yen; Nguyen, Hung Vo

    2005-01-01

    Over the last thirty years, Vietnam evolved from `war after war' to an emerging economy with an attractive foreign investment policy and commitment to a liberalized economy. Although the GDP per capita is still considerably lower than in the Asian Tiger economies, and the institutional framework...... still reflects inheritances from the central plan system, Vietnam today has a vibrant economy with small businesses springing up at every street corner. Foreign investors have been flogging to Vietnam since the early 1990s, with a new peak of FDI inflow in 2004. This paper reviews the Vietnamese economy......, society, culture, and policies towards foreign investment to inform those considering to invest in Vietnam, and to provide some practical advice....

  7. An Alternative Vaccination Approach for The Prevention of Highly Pathogenic Avian Influenza Subtype H5N1 in The Red River Delta, Vietnam —A Geospatial-Based Cost-Effectiveness Analysis

    Directory of Open Access Journals (Sweden)

    Chinh C. Tran

    2016-02-01

    Full Text Available This study addresses the tradeoff between Vietnam’s national poultry vaccination program, which implemented an annual two-round HPAI H5N1 vaccination program for the entire geographical area of the Red River Delta during the period from 2005–2010, and an alternative vaccination program which would involve vaccination for every production cycle at the recommended poultry age in high risk areas within the Delta. The ex ante analysis framework was applied to identify the location of areas with high probability of HPAI H5N1 occurrence for the alternative vaccination program by using boosted regression trees (BRT models, followed by weighted overlay operations. Cost-effectiveness of the vaccination programs was then estimated to measure the tradeoff between the past national poultry vaccination program and the alternative vaccination program. Ex ante analysis showed that the focus areas for the alternative vaccination program included 1137 communes, corresponding to 50.6% of total communes in the Delta, and located primarily in the coastal areas to the east and south of Hanoi. The cost-effectiveness analysis suggested that the alternative vaccination program would have been more successful in reducing the rate of disease occurrence and the total cost of vaccinations, as compared to the national poultry vaccination program.

  8. Ultrafast electron relaxation in superconducting Bi(2)Sr(2)CaCu(2)O(8+delta) by time-resolved photoelectron spectroscopy.

    Science.gov (United States)

    Perfetti, L; Loukakos, P A; Lisowski, M; Bovensiepen, U; Eisaki, H; Wolf, M

    2007-11-09

    Time-resolved photoelectron spectroscopy is employed to study the dynamics of photoexcited electrons in optimally doped Bi{2}Sr{2}CaCu{2}O{8+delta} (Bi-2212). Hot electrons thermalize in less than 50 fs and dissipate their energy on two distinct time scales (110 fs and 2 ps). These are attributed to the generation and subsequent decay of nonequilibrium phonons, respectively. We conclude that 20% of the total lattice modes dominate the coupling strength and estimate the second momentum of the Eliashberg coupling function lambdaOmega{0}{2}=360+/-30 meV{2}. For the typical phonon energy of copper-oxygen bonds (Omega{0} approximately 40-70 meV), this results in an average electron-phonon coupling lambda<0.25.

  9. STIRAP preparation of a coherent superposition of ThO $H^3\\Delta_1$ states for an improved electron EDM measurement

    CERN Document Server

    Panda, C D; West, A D; Baron, J; Hess, P W; Hoffman, C; Kirilov, E; Overstreet, C B; West, E P; DeMille, D; Doyle, J M; Gabrielse, G

    2016-01-01

    Experimental searches for the electron electric dipole moment (EDM) probe new physics beyond the Standard Model. The current best EDM limit was set by the ACME Collaboration [Science \\textbf{343}, 269 (2014)], constraining time reversal symmetry ($T$) violating physics at the TeV energy scale. ACME used optical pumping to prepare a coherent superposition of ThO $H^3\\Delta_1$ states that have aligned electron spins. Spin precession due to the molecule's internal electric field was measured to extract the EDM. We report here on an improved method for preparing this spin-aligned state of the electron by using STIRAP. We demonstrate a transfer efficiency of $75\\pm5\\%$, representing a significant gain in signal for a next generation EDM experiment. We discuss the particularities of implementing STIRAP in systems such as ours, where molecular ensembles with large phase-space distributions are transfered via weak molecular transitions with limited laser power and limited optical access.

  10. STM studies of the electronic structure of vortex cores in Bi(2)Sr(2)CaCu(2)O(8+delta)

    Science.gov (United States)

    Pan; Hudson; Gupta; Ng; Eisaki; Uchida; Davis

    2000-08-14

    We report on low temperature scanning tunneling microscopy (STM) studies of the electronic structure of vortex cores in Bi 2Sr 2CaCu 2O (8+delta). At the vortex core center, an enhanced density of states is observed at energies near Omega = +/-7 meV. Spectroscopic imaging at these energies reveals an exponential decay of these "core states" with a decay length of 22+/-3 A. The fourfold symmetry sometimes predicted for d-wave vortices is not seen in spectroscopic vortex images. A locally nodeless order parameter induced by the magnetic field may be consistent with these measurements.

  11. The Vietnam War

    DEFF Research Database (Denmark)

    Godbolt, James; Larsen, Chris Holmsted; Rasmussen, Søren Hein

    2009-01-01

    This article investigates the role of the Vietnam War in Danish and Norwegian politics. We argue that Danish and Norwegian membership in NATO and an unstable parliamentary situation may explain why these countries, unlike Sweden, did not take on the lead in the international protest against the war...... in Denmark, Sweden and Norway, and in all three countries powerful protest movements emerged that were remarkably similar. The Vietnam War strengthened the left in general and promoted a leftist politics of solidarity that influenced Swedish, Danish and Norwegian foreign policy-making of the 1970s....

  12. Upstream profitability in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Ingeberg, K.

    1993-12-01

    This report outlines the main characteristics of the petroleum industry in Vietnam. First, it discusses the exploration history and the fiscal regime and concession system for international companies searching for new exploration ventures in the country. Second, it presents an economic analysis of exploration and field development decisions. The analysis is based on a cash flow tax model reflecting the current economic framework. Calculations of upstream profitability are based on typical offshore oil project assumptions. The analysis includes the effects of different levels of exploration risks, tax position and tax agreements. The report also compares fiscal terms in Vietnam and Malaysia and their effect on attractivity. 20 refs., 3 figs., 19 tabs.

  13. Percolation and electronic properties of superconducting (YBa sub 2 Cu sub 3 O sub 7 minus. delta. ) sub 1 minus x Ag sub x ceramics and thick films

    Energy Technology Data Exchange (ETDEWEB)

    Dwir, B.; Pavuna, D.; Affronte, M.; Berger, H. (Swiss Federal Institute of Technology, Lausanne (Switzerland)); Tholence, J.L. (C.R.T.B.T., Grenoble (France))

    1989-09-01

    The authors present the percolation and electronic properties of (Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}){sub 1{minus}x}Ag{sub x} compounds in which silver fills the intergranular space without reducing {Tc}, which remains at 92 {plus minus} 1 K. Normal-state resistivity is decreased by up to two orders of magnitude when adding up to 50 wt.% Ag({Tc} = 87 K), and samples exhibit improved contact resistance, better mechanical properties, and resistance to water. They analyzed the percolation properties of these compounds and found that the critical indices t, s are in agreement with percolation theory, but p{sub c} is higher than expected, probably due to the effect of holes. The J{sub c} estimated from magnetization reaches 5 {center dot} 10{sup 4} A/cm{sup 2} (at T = 4.2 K, H = 0) and shows enhancement of 15-50% by addition of {approximately} 10 wt.% Ag, which exists also in samples having a higher J{sub c} due to preparation conditions (temperature). They present preliminary results on the 2D percolation problem in (Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}){sub 1{minus}x}Ag{sub x} samples, obtained by preparing Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thick films using the spin-on technique. Preliminary results show good adhesion but a reduced {Tc} of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} films compared with bulk samples.

  14. Two-year intervention trial to control of fish-borne zoonotic trematodes in giant gourami (Osphronemus goramy) and striped catfish (Pangasianodon hypophthalmus) in nursery ponds in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Madsen, H; Thien, P C; Nga, H T N; Clausen, J H; Dalsgaard, A; Murrell, K D

    2015-12-01

    Fish-borne zoonotic trematode parasites (FZT) pose a food safety and public health problem in Vietnam. The transmission cycle is complex as domestic animals, especially dogs, cats, fish-eating birds and pigs together with humans serve as reservoir hosts and contribute to FZT egg contamination of aquaculture ponds and the environment. This intervention trial was conducted to determine the effectiveness of various on-farm interventions, including reduction in FZT egg contamination through treatment of infected people and domestic animals, reduction in snail density through mud removal from aquaculture ponds prior to fish stocking, and various other measures in reducing FZT infection in juvenile striped catfish (Pangasianodon hypophthalmus) and giant gourami (Osphronemus goramy). Interventions were implemented on 5 farms for each fish species during production cycles in 2009 and 2010 while 5 similar farms for each species served as control. For both fish species, both prevalence and intensity of infection did not differ significantly between intervention and non-intervention farms prior to the interventions. The interventions significantly reduced both prevalence and intensity of FZT infection in the juvenile fish compared to control ponds. For giant gourami, odds of infection in intervention ponds was 0.13 (95% CL: 0.09-0.20; p<0.001) of that in non-intervention ponds after the 2009 trial and 0.07 (0.03-0.14; p<0.001) after the 2010 trial. For striped catfish, these figures were 0.17 (0.08-0.35; p<0.001) after the 2009 trial while after the 2010 trial all ponds with interventions were free from infection. Metacercariae intensity (no. of metacercariae/fish) in giant gourami from intervention ponds was 0.16 (0.11-0.23; p<0.001) of that in fish from non-intervention ponds after the 2009 trial and 0.07 (0.04-0.15; p<0.001) after the 2010 trial; for striped catfish these figures were 0.18 (0.09-0.36; p<0.001) and 0.00 (confidence limits not estimated), respectively. The

  15. Vietnam in Childrens' Books.

    Science.gov (United States)

    United Nations Children's Fund, New York, NY. United States Committee.

    Twenty-five nonfiction and 18 fiction and folklore listings are included in this bulletin on Vietnam in childrens' books. Slides, filmstrips, and film listings are also included. Each listing is accompanied by a brief annotation. Subjects include customs and culture, the country and the people, Ho Chi Min, the Vietnamese revolution, Vietnamese…

  16. Rural Credit in Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel Christoffer; Tarp, Finn

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders, but formal loans are almost entirely for production and asset accumulation. Interest rates fell from 1997...... to credit policy is clearly inappropriate....

  17. China and Vietnam tourism electronic commercial cooperation research and conception%中越旅游电子商务合作研究与构想

    Institute of Scientific and Technical Information of China (English)

    梁海跃

    2011-01-01

    China and Viet Nam linked land,After the Chinese-Association of Southeast Asian Nations free trading area completes,China and Vietnam continue to strengthen tourism cooperation.With the growing maturity of e-commerce technology and the continuous developm%中国和越南国土相连,中国—东盟自由贸易区建成后,中国与越南的旅游合作不断加强。随着电子商务技术日趋成熟,全球旅游电子商务的不断发展,开展中越旅游电子商务合作是中越旅游业进一步发展与合作的要求和选择。

  18. Chinese Commodities and Vietnam Market

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Last April, with the support of China Machinery Industry Federation and Vietnam Em bassy in China, the Society of Automotive Engineers of CCPIT successfully held "China Famous Brand Auto Vietnam Show". I am informed that the Organizing Committee plans to hold the 3rd China Auto International Exhibition Tour in this November. According to the agenda, this activity will extend from Vietnam to other ASEAN member countries, therefore, it will have a larger scale, a longer route and a richer content. On beha...

  19. Vietnam's Labour Market in Transition

    OpenAIRE

    Adam McCarty

    2001-01-01

    This report examines the employment structure and structural change (1986-1999) of Vietnam, discusses Vietnam's labour market regulations and examines how Vietnam's labour markets could become more efficient. Vietnam’s labour policies remain focused on control of state enterprises: who they employ, how many, and what they pay them. The Labour Code of 1995 saw a move to extend state worker privileges throughout the economy. This is a futile exercise to establish a welfare state in a country wi...

  20. The U.S. Community College Model and Vietnam's Higher Education System.

    Science.gov (United States)

    Oliver, Diane

    This paper reports on research conducted to determine if United States' community college model can be applied to higher education systems in developing countries. The author examined Vietnam's higher education system and conducted a case study of Can Tho University (CTU) in the Mekong Delta. First, common characteristics found among community…

  1. Observational $\\Delta\

    CERN Document Server

    Hernández, Antonio García; Monteiro, Mário J P F G; Suárez, Juan Carlos; Reese, Daniel R; Pascual-Granado, Javier; Garrido, Rafael

    2015-01-01

    Delta Scuti ($\\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\\delta$ Sct stars.

  2. Electronic standing waves on the surface of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Vershinin, M.; Misra, S.; Abe, Y.; Ono, S.; Ando, Y.; Yazdani, A

    2004-08-01

    Scanning tunneling microscopy (STM) measurements have shown that electronic states at the surface of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single crystals form standing wave patterns at temperatures far below the superconducting transition. It has been shown that these patterns are consistent with those expected from the interference of well-defined quasi-particles around the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} Fermi surface. We have extended STM measurements of these standing wave patterns to higher temperatures and have found that four unit-cell periodicity patterns observed in the superconducting state persist well above T{sub C}, in the pseudogap state. In this regime, many different experimental studies of the cuprates have long claimed the absence of well-defined quasi-particles. If the pseudogap regime is indeed devoid of any coherent quasi-particles then our results suggest that other phenomena, such as stripe formation, must play a role in formation of these patterns.

  3. Electronic structure of {delta}-Ta{sub 2}O{sub 5} with oxygen vacancy: ab initio calculations and comparison with experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Maxim V.; Perevalov, Timofey V.; Aliev, Vladimir S.; Gritsenko, Vladimir A. [A. V. Rzhanov Institute of Semiconductor Physics SB RAS, Novosibirsk, 630090 (Russian Federation); Kaichev, Vasily V. [Boreskov Institute of Catalysis SB RAS, Novosibirsk, 630090 (Russian Federation)

    2011-07-15

    Electronic structure of oxygen vacancies in Ta{sub 2}O{sub 5} have been studied theoretically by first-principles calculations and experimentally by x-ray photoelectron spectroscopy. Calculations of {delta}-Ta{sub 2}O{sub 5} were performed using density functional theory within gradient-corrected approximation with the +U approach. Results indicate that the oxygen vacancy causes a defect level in the energy gap at 1.2 eV above the top of the valence band. To produce oxygen vacancies, amorphous films of Ta{sub 2}O{sub 5} were bombarded with Ar{sup +} ions. XPS results indicate that the Ar-ion bombardment leads to the generation of the oxygen vacancies in Ta{sub 2}O{sub 5} that characterize the peak at 2 eV above the valence band. The calculated spectrum of crystalline {delta}-Ta{sub 2}O{sub 5} demonstrates qualitative correspondence with the XPS spectrum of the amorphous Ta{sub 2}O{sub 5} film after Ar-ion bombardment.

  4. Site-specific electronic structure of Pr in $Pr_{1+x} Ba_{2-x} Cu _{3} O_{7-} \\delta$

    CERN Document Server

    Staub, U; O'Conner, A G; Kramer, M J; Knapp, M

    2001-01-01

    We report on resonant X-ray powder-diffraction measurements in the vicinity of the Pr L/sub 3/ absorption edge of Pr/sub 1+x/Ba/sub 2-x /Cu/sub 3/O/sub 7- delta /. The Pr site occupation has been accurately determined: 6+or-2% of the Pr is on the Ba site. From an analysis of the energy dependence of selected Bragg reflections, the site-specific oxidation state of Pr has been obtained. These results are discussed in the context of models describing the suppression of superconductivity by Pr, and they indicate that Pr on the R site is responsible for T/sub c/ suppression. (34 refs).

  5. Teaching in Vietnam

    CERN Multimedia

    Vitale,B

    1974-01-01

    Monsieur B.Vitale porte depuis plusieurs années un grand interêt aux questions d'enseignement dans les pays du tiers monde et a recemment eu l'occasion de faire un séjour dans la république démocratique du Vietnam. Il va nous faire part de ses impressions dans le domaine de l'enseignement, qu'il a vu, entrevu et essayé de comprendre

  6. Flood loss assessment in Can Tho City, Vietnam

    Science.gov (United States)

    Do, T. C.; Kreibich, H.

    2012-04-01

    Floods are recurring events in the Lower Mekong Basin resulting in loss of life and property, causing damage to agriculture and rural infrastructure, and disrupting social and economic activities. Flood management and mitigation has become a priority issue at the national and regional levels. Besides, it is expected that large areas of the Mekong delta, the Red River delta and the central coast will be flooded by sea-level rise due to climate change. Can Tho City is ranked under the five most flood-tide-influenced cities of Vietnam. It is the biggest city in the Mekong delta and it is located near the Hau river. Like other region of the Mekong delta, Can Tho suffers due to floods from upstream and flood tides from the sea. In the flood season large rural areas of the city are flooded, particularly during tidal days. Flood risk management policy includes preparative measures for living with floods and to minimise the damage caused by floods as well as to take advantage of floods for sustainable development. An intensive literature review, including administrative reports as well as expert interviews have been undertaken to gain more insight into flood characteristics, their consequences and risk mitigation. Therefore, flood damaging processes and trends have been reviewed for Can Tho City and the Mekong Basin in Vietnam. Additionally, suitable flood damage estimation methodologies have been collected as important input for flood risk analyses. On this basis it has been investigated which flood risk mitigation and management strategies promise to be effective in Can Tho City, Vietnam.

  7. The Lessons of the Vietnam War.

    Science.gov (United States)

    Starr, Jerold M., Ed.

    This text book on the Vietnam War is to be used in teaching high students. Each of the volume's 12 chapters is a self-contained unit on an aspect of the War. The chapters are: (1) Introduction to Vietnam: land, history, and culture; (2) America at war in Vietnam: decisions and consequences; (3) Was the Vietnam War legal? (4) who fought for the…

  8. Developing School Psychology in Vietnam

    Science.gov (United States)

    Le, Phuong; Hagans, Kristi; Powers, Kristin; Hass, Michael

    2011-01-01

    Like China, Vietnam is a communist country with increasingly capitalist economic policies. A fundamental change occurred in these policies with the enactment of Vietnam's "doi moi" (renovation) policy in 1986 that called for a "free market with socialist orientations." However, this economic modernization has inadvertently…

  9. Vietnam in the English Classroom.

    Science.gov (United States)

    Johannessen, Larry R.

    Vietnam War literature offers students a unique mix of themes which in many ways speak directly to them as, perhaps, no other literature is able to. This literature can help them better understand literature, history, the world they live in, and themselves, as well as the Vietnam War. A sequence of classroom activities (beginning with an…

  10. Developing School Psychology in Vietnam

    Science.gov (United States)

    Le, Phuong; Hagans, Kristi; Powers, Kristin; Hass, Michael

    2011-01-01

    Like China, Vietnam is a communist country with increasingly capitalist economic policies. A fundamental change occurred in these policies with the enactment of Vietnam's "doi moi" (renovation) policy in 1986 that called for a "free market with socialist orientations." However, this economic modernization has inadvertently changed the social…

  11. Delta Electroproduction in 12-C

    Energy Technology Data Exchange (ETDEWEB)

    Steven McLauchlan

    2003-01-31

    The Delta-nucleus potential is a crucial element in the understanding of the nuclear system. Previous electroexcitation measurements in the delta region reported a Q2 dependence of the delta mass indicating that this potential is dependent on the momentum of the delta. Such a dependence is not observed for protons and neutrons in the nuclear medium. This thesis presents the experimental study of the electroexcitation of the delta resonance in 12C, performed using the high energy electron beam at the Thomas Jefferson National Accelerator Facility, and the near 4(pie) acceptance detector CLAS that enables the detection of the full reaction final state. Inclusive, semi inclusive, and exclusive cross sections were measured with an incident electron beam energy of 1.162GeV over the Q2 range 0.175-0.475 (GeV/c)2. A Q2 dependence of the delta mass was only observed in the exclusive measurements indicating that the delta-nucleus potential is affected by the momentum of the delta.

  12. Delta robot

    NARCIS (Netherlands)

    Herder, J.L.; Van der Wijk, V.

    2010-01-01

    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  13. Delta robot

    NARCIS (Netherlands)

    Herder, J.L.; Van der Wijk, V.

    2010-01-01

    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  14. Rural Credit in Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel Christoffer; Tarp, Finn

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders, but formal loans are almost entirely for production and asset accumulation. Interest rates fell from 1997...... to 2002, reflecting increased market integration; but the determinants of formal and informal credit demand are distinct. Credit rationing depends on education and credit history, but we find no evidence of a bias against women. Regional differences are striking, and a ‘one size fits all’ approach...

  15. Sustainable urbanization in Vietnam.

    Science.gov (United States)

    Drakakis-smith, D; Dixon, C

    1997-01-01

    "This paper examines the nature of [urban-based economic growth in Vietnam] and contends that the present size of Ho Chi Minh City and Hanoi are much greater than official figures suggest. It then goes on to review the situation with regard to urban poverty, basic needs and the environment to illustrate the extent to which this unacknowledged growth is not only threatening the sustained expansion of those cities, but also the sustainability of the economic growth on which the country is so reliant."

  16. Social and ecological challenges of market-oriented shrimp farming in Vietnam.

    Science.gov (United States)

    Lan, Ngo Thi Phuong

    2013-01-01

    Vietnam is one of the largest shrimp exporters in the world. Since 2010, Vietnam has earned about two billion dollars annually through shrimp exports. As a fertile area of greatest potential for agricultural production in Vietnam, the Mekong Delta has been a major contributor to the country's achievements, especially in the agricultural sector. During recent decades, trade liberation along with various policies in support of aquaculture has accelerated the development of shrimp production in the Delta. Based on an ethnographic study of shrimp farming in the Mekong Delta of Vietnam, I assert that along with great rewards arising from the expansion of shrimp farming areas, productivity, and export value, the shrimp industry has brought various environmental, economic and social challenges. Consequently, shrimp farming is a risky business and local inhabitants have relied on various strategies to cope with these challenges. Risk mitigation in shrimp production and labor migration are the two important strategies of local inhabitants for securing their livelihoods. Water pollution and poor quality post-larvae shrimp are direct consequences of market-oriented production.

  17. Pharmacy Education in Vietnam

    Science.gov (United States)

    Bedouch, Pierrick; Nguyen, Thi-Hoai; Nguyen, Thi-Lien-Huong; Hoang, Thi-Kim-Huyen; Calop, Jean; Allenet, Benoît

    2013-01-01

    Pharmacy education programs in Vietnam are complex and offer various career pathways. All include theory and laboratory modules in general, foundation, and pharmaceutical knowledge; placements in health facilities; and a final examination. The various pharmacy degree programs allow specialization in 1 or more of 5 main fields: (1) drug management and supply, (2) drug development and production, (3) pharmacology and clinical pharmacy, (4) traditional medicine and pharmacognosy, and (5) drug quality control, which are offered as main specialization options during the reformed undergraduate and postgraduate programs. However, pharmacy education in Vietnam in general remains product oriented and clinical pharmacy training has not received adequate attention. Only students who have obtained the bachelor of pharmacy degree, which requires a minimum of 5 years of study, are considered as fully qualified pharmacists. In contrast, an elementary diploma in pharmacy awarded after 1 year of pharmacy study permits entry into more junior pharmacy positions. Since the 2000s, there has been a surge in the number and types of schools offering pharmacy qualifications at various levels. PMID:23966717

  18. Vietnam: achievements and challenges.

    Science.gov (United States)

    Tran Tien Duc

    1999-01-01

    The Vietnamese Government's successful development of the National Population and Family Planning Program has contributed in raising people's awareness on population issues and changing their attitudes and behavior regarding fostering small families. It has also been found to be very effective in substantially decreasing fertility level. In addition, economic levels of many households have been greatly improved since the adoption of a renovation policy. The advancement of welfare accompanied by the provision of better basic social services, including health services, has boost people's health. Several factors behind the achievements of the National Population and Family Planning Program include: 1) Strengthening of the political commitment of national and local leaders; 2) Nationwide mobilization of mass organizations and NGOs; 3) A strong advocacy and information, education and communication program; 4) Provision of various kinds of contraceptives; 5) Effective management of the program by priority; and 6) Support of the international community. Despite such successes, Vietnam is facing a number of new issues such as enlargement of the work force, shifting migration patterns and accelerating urbanization, aging of population, and change of household structure. Nevertheless, the Government of Vietnam is preparing a New Population Strategy aimed to address these issues.

  19. Deformation characteristics of {delta} phase in the delta-processed Inconel 718 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.Y., E-mail: haiyanzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, S.H., E-mail: shzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cheng, M. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Z.X. [Beijing Institute of Aeronautica1 Materials, Beijing 100095 (China)

    2010-01-15

    The hot working characteristics of {delta} phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 deg. C and strain rate of 0.005 s{sup -1}, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like {delta} phase and the precipitation of spherical {delta} phase particles coexisted during the deformation, and the content of {delta} phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like {delta} phase was spheroidized and transferred to spherical {delta} phase particles. In the center with largest strain, the plate-like {delta} phase disappeared and spherical {delta} phase appeared in the interior of grains and grain boundaries.

  20. Magnetic susceptibility measurements of {sigma} plutonium alloys. Contribution to the study of the 5f electrons localization in the plutonium; Mesure de la susceptibilite magnetique d`alliages de plutonium en phase delta. Contribution a l`etude de la localisation des electrons 5f dans le plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Meot-Reymond, S

    1996-12-31

    Physical properties of actinide metals are essentially ruled by the 5f electrons localization. From a theoretically point of view, this localization is more important in the {delta}-phase than in the {alpha}-one. To compare their magnetic behaviour, low temperature magnetic susceptibility measurements have been performed and previous-resistivity data have been analysed. Experimental results and theoretical data can be conciliate by the existence of a Kondo effect in the {delta}-Pu phase. (author) 63 refs.

  1. What is $\\Delta m^2_{ee}$ ?

    CERN Document Server

    Parke, Stephen

    2016-01-01

    The current short baseline reactor experiments, Daya Bay and RENO (Double Chooz) have measured (or are capable of measuring) an effective $\\Delta m^2$ associated with the atmospheric oscillation scale of 0.5 km/MeV in electron anti-neutrino disappearance. In this paper, I compare and contrast the different definitions of such an effective $\\Delta m^2$ and argue that the simple, L/E independent, definition given by $\\Delta m^2_{ee} \\equiv \\cos^2 \\theta_{12} \\Delta m^2_{31}+ \\sin^2 \\theta_{12} \\Delta m^2_{32}$, i.e. "the $\

  2. Vietnam, Four American Perspectives: Lectures

    OpenAIRE

    McGovern, George S.; Westmoreland, William C.; Luttwak, Edward N.; McCormick, Thomas J.; Hearden, Patrick F.

    1990-01-01

    This collection of speeches delivered in 1987 presents the widely diverging opinions of four men: an eminent politician, a professional soldier, a government consultant, and a distinguished scholar. The first contributor, Senator George S. McGovern, ran as the Democratic candidate for president in 1972 on a platform that called for the withdrawal of American troops from Vietnam. The second speaker, General William C. Westmoreland, commanded American military forces in Vietnam until growing ba...

  3. Identification of new isolates of Bacillus thuringiensis using rep-PCR products and delta-endotoxin electron microscopy

    Directory of Open Access Journals (Sweden)

    A.S.G. Lima

    2002-01-01

    Full Text Available PCR has been used to analyze the distribution of REP (Repetitive Extragenic Palindromic and ERIC (Enterobacterial Repetitive Intergenic Consensus sequences (rep-PCR found within the genome of the bacterium Bacillus thuringiensis, with the purpose to analyze the genetic similarities among 56 subspecies samples and 95 field isolates. The PCR products were analyzed by EB-AGE (ethidium bromide-agarose electrophoresis and then submitted to banding comparisons, based on the Phyllip software algorithm. When the banding similarities were considered for comparison purposes among all the strains, the phylogenic tree patterns varied according to the rep-PCR primers considered, but, from a broader point of view, the ERIC sequences produced better results, which, together with electron microscopy analysis of the released parasporal bodies and colony morphology characteristics, allowed to detect two possible new subspecies of B. thuringiensis.

  4. Structural, electronic and flux dynamics of Gd(Ba2-xPrxCu3O7+& delta superconductor

    Directory of Open Access Journals (Sweden)

    M. R. Mohammadizadeh and M Akhavan

    2004-06-01

    Full Text Available   The Gd(Ba2-xPrxCu3O single phase polycrystalline samples with 0.00 ≤ x ≤ 1.00 were investigated for structural, electronic and flux dynamic properties. An unusual hump on the resistivity vs. temperature curve of the samples has been observed for particular values of Pr doping. We have found that the Ba atom substitution at the rare earth site could lead to superconductivity in some parts of the grains at Tm~80-90K, which appears as a hump on the (T curve. For all the samples, the two-dimensional variable range hopping (VRH is a dominant conduction mechanism in the normal state. The Pr doping strongly localizes the carriers in the normal state, and finally causes the suppression of superconductivity. The effect of Pr substitution in 123 structure of HTSC at R or Ba site is to increase the pseudo gap temperature Ts, although, Pr at Ba site has a stronger effect on the increase of Ts and suppression of superconductivity. We have also extracted the two dimensionality aspects of HTSC through the similarities between superconductors, two-dimensional electron gas (2D-EG i.e., MOSFETs, and the ultra thin films of conventional superconductors. The magneto resistance of the samples have been studied within thermally activated flux creep and the Ambegaokar and Halperin phase slip models. The derived critical current density, Hc2(T, Hc2(0, and superconducting coherence length show that the Pr- doping, like weak links, decreases the vortex flux pinning energy. Our results imply that understanding the real suppression mechanism of superconductivity by Pr doping in HTSC is connected unavoidably to determination of the exact position of Pr in the structure.

  5. Accurate measurement of electron beam polarization using Compton effect at TJNAF for the experiments G{sup p}{sub E} and N-{delta}; Mesure precise de la polarisation du faisceau d'electrons a TJNAF par polarimetrie compton pour les experiences G{sup p}{sub E} et N-{delta}

    Energy Technology Data Exchange (ETDEWEB)

    Escoffier, St

    2001-10-01

    This work deals with electron beam polarization measurements using Compton effect at TJNAF, for experiments of the proton electromagnetic form factors measurement and for nucleon response functions determination in the pion electroproduction reaction near the {delta}(1232) region. The Compton polarimeter, whose principle is built on elastic electron-photon scattering, was designed and built around a high finesse Fabry-Perot cavity (finesse = 25000). The incident Nd:YAG laser power is amplified by an optical cavity which provides a luminosity such as the statistical uncertainty on the electron polarization measurement is at the level of 1% in one hour. Using Pound-Drever method, laser frequency is locked on one of interferometer resonance frequencies. Circularly photon polarization inside the optical cavity was measured to be 99.6+/-0.45%. The electron beam polarization is deduced from the measurements of the photon polarization, experimental asymmetry and analysing power of our detector. The analysing power is determined by a measurement of the response function of the photon detector, composed of 25 PbWO{sub 4} crystals, thanks to coincidence events detected with the electron detector made up of 4 plans of 48 silicon strips. Measurement uncertainties come meanly from detector's response function modelling, pile up effect and photon beam polarization. Total relative uncertainty on the electron beam polarization measurement is about 1.4% for 40 minutes data taking. Moreover, the Compton polarimeter allows to estimate the electron helicity difference between two polarization reversals. This effect was found compatible with zero at 0.3%. (author)

  6. Historical perspectives on typhoons and tropical storms in the natural and socio-economic system of Nam Dinh (Vietnam)

    NARCIS (Netherlands)

    Kleinen, J.

    2007-01-01

    This contribution starts with a brief introduction of the effects of typhoons and tropical storms on Vietnam, focusing in particular on the coastal region of Nam Dinh, a province in the northern part of the country and part of the Red River Delta. The magnitude of damage caused by a natural disaster

  7. Investigations of the electron phase space dynamics in triggered whistler wave emissions using low noise \\delta f method

    Science.gov (United States)

    Tao, Xin; Zonca, Fulvio; Chen, Liu

    2017-09-01

    The evolution of the electron phase space structures during excitation of a triggered emission is investigated using the nonlinear δ f method. Previous studies suggested that the dynamics of phase space structures due to nonlinear wave particle interactions is critical to the excitation of triggered emissions with frequency chirping. We introduce the use of the nonlinear δ f method to simulate triggered emissions. Compared with full-f particle-in-cell method, the nonlinear δ f method significantly reduces numerical noise, therefore making the phase space structures more identifiable. Specific to the simulation of triggered emissions, the nonlinear δ f method also does not show numerical distortion of the distribution function due to reflecting particle boundary conditions. Using the nonlinear δ f method, we show that during the main portion of the chirping element, the phase space structure roughly maintains a shape so that the resonant island moves a distance in phase space that is on the same order as its width during one phase space bounce period of deeply trapped particles, supporting that the interaction is non-adiabatic. We also demonstrate the disappearance of the phase space structure near the end of the chirping. Our work suggests that the nonlinear δ f method could be very useful for the study of excitation of triggered emissions and to understand the mechanism of frequency chirping.

  8. Improved two-dimensional electron mobility in asymmetric barrier delta-doped GaAs/AlGaAs modulation-doped field-effect transistor structures

    Science.gov (United States)

    Das, Sudhakar; Mohapatra, Meryleen; Nayak, Rasmita K.; Panda, Ajit K.; Sahu, Trinath

    2017-03-01

    We study the enhancement of electron mobility μ in barrier delta-doped GaAs/AlGaAs quantum-well-based modulation-doped field-effect transistor (MODFET) structures. We asymmetrically vary the doping concentrations N d1 and N d2 in the barriers on the substrate and surface sides, respectively, to obtain a nonlinear enhancement of μ as a function of the well width w through multi-subband effects. We show that an increase in doping concentration increases the surface electron density N s, which in turn enhances μ. Interchanging N d1 and N d2 leads to no change in N s but rather, an enhancement of μ as a function of w for N d2 > N d1 owing to asymmetric variation of subband wave functions, thereby implying a higher channel conductivity in a surface-doped structure than in an inverted doped structure. By keeping (N d1 + N d2) unchanged, the conductivity of a single-channel MODFET, N d1 (N d2) ≠ 0 and N d2 (N d1) = 0, can be enhanced by considering a MODFET based on an asymmetrically doped (N d1 ≠ N d2 ≠ 0) quantum well structure. We show that the highest N s and μ product for these structures occurs almost before the onset of the occupation of the second subband. Our analysis of the effect of asymmetric doping profiles on channel conductivity can be utilized for the performance improvement of MODFET-like devices.

  9. E- and M-Commerce and Payment Sector Development in Vietnam

    OpenAIRE

    International Finance Corporation

    2014-01-01

    This study investigates the state of the electronic (e) and mobile (m)-commerce sector in Vietnam and its impact on the development of cashless payments and online financial services. The e- and m-commerce sector in Vietnam is growing organically. Although still immature and small in volume, advances in the region suggest that the sector will continue to expand and that investment is incre...

  10. Flexibility, Reach, and the Vietnam Fire Base

    Science.gov (United States)

    2014-05-22

    48 v ACRONYMS AVRN Army of the Republic of Vietnam COIN Counterinsurgency DRV Democratic Republic of Vietnam DOD Department of...insect-transmitted diseases like malaria, dengue, and encephalitis. Cholera , hepatitis, and typhoid were common in the countryside because of a...watch? v =Q-m96RoxwrI (accessed 18 January 2014). 75PBS, “Battlefield: Vietnam; The Siege at Khe Sanh,” Battlefield Vietnam Web Site, Adobe Shockwave

  11. Study on nuclear power introduction into Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Vuong Huu Tan [Vietnam Atomic Energy Commission, 59 Ly Thuong Kiet, Hanoi (Viet Nam)

    2000-03-01

    The report presents main results of the study on nuclear power introduction into Vietnam which have been carried out at Vietnam Atomic Energy Commission in collaboration with Ministry of Industry of Vietnam and other countries like Japan, Canada and Korea. The study covers all topics related to the nuclear power introduction into Vietnam such as electricity demands and supply, economics, finance, technology, safety, manpower, site selection etc. (author)

  12. Higher Education in Vietnam: Change and Response.

    Science.gov (United States)

    Sloper, David, Ed.; Le, Thac Can, Ed.

    This collection of 12 essays examines the development of higher education in Vietnam, focusing on current issues related to educational reform, expansion, and funding. They are: (1) "Higher Education in Vietnam: The Door Opens--From Inside" (Le Thac Can and David Sloper); (2) "Socio-Economic Background of Vietnam Since 1986: Impact on Education…

  13. Electronic structure of delta-doped La:SrTiO{sub 3} layers by hard x-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, A. M. [Department of Physics, University of California, Davis, California 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Peter-Gruenberg-Institut PGI-6, Forschungszentrum Juelich, 52425 Juelich (Germany); Gray, A. X. [Department of Physics, University of California, Davis, California 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Conti, G.; Fadley, C. S. [Department of Physics, University of California, Davis, California 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Jalan, B. [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States); Department of Chemical Engineering and Materials Science, University of Minnesota, Twin Cities, Minnesota 55455 (United States); Kajdos, A. P.; Stemmer, S. [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States); Gloskovskii, A. [Institut fuer Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Ueda, S.; Yamashita, Y.; Kobayashi, K. [NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan); Drube, W. [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

    2012-06-25

    We have employed hard x-ray photoemission (HAXPES) to study a delta-doped SrTiO{sub 3} layer that consisted of a 3-nm thickness of La-doped SrTiO{sub 3} with 6% La embedded in a SrTiO{sub 3} film. Results are compared to a thick, uniformily doped La:SrTiO{sub 3} layer. We find no indication of a band offset for the delta-doped layer, but evidence of the presence of Ti{sup 3+} in both the thick sample and the delta-layer, and indications of a density of states increase near the Fermi energy in the delta-doped layer. These results further demonstrate that HAXPES is a powerful tool for the non-destructive investigation of deeply buried doped layers.

  14. Interface structure and electronic properties of SrTiO{sub 3} and YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} crystals and thin films

    Energy Technology Data Exchange (ETDEWEB)

    Thiess, S.

    2007-07-01

    Two new extensions of the X-ray standing wave (XSW) technique, made possible by the intense highly collimated X-ray beams from undulators at the ESRF, are described in this thesis. First, the XSW method was applied in a structural study to solve the nucleation mechanism of the high temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} on the (001) surface of SrTiO{sub 3}. Second, the valence electronic structures of SrTiO{sub 3} and YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} were investigated. Finally, recent developments in the field of photoelectron spectroscopy in the hard X-ray region are described. The X-ray standing wave method is used in combination with fluorescence, Auger or photoelectron spectroscopy and lends very high spatial resolution power to these analytical techniques. Previously, the XSW method has been used for structure determination of surfaces and interfaces. The currently available X-ray intensities permit extensions to the XSW technique. Two recently established applications, described in this thesis, are XSW real space imaging and XSW valence electronic structure analysis. XSW real space imaging was employed to analyse the atomic structure of 0.5 and 1.0 layers of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} deposited on SrTiO{sub 3}(001). Three-dimensional images of the atomic distributions were reconstructed for each of the elements from experimentally determined Fourier components of the atomic distribution functions. The images confirmed the formation of a perovskite precursor phase prior to the formation of the YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} phase during the growth of the first monolayer of the film. XSW valence electronic structure analysis applied to SrTiO{sub 3} identified the valence band contributions arising from the strontium, titanium, and oxygen sites of the crystal lattice. Relations between the site-specific valence electronic structure and the lattice structure were established. The experimental results agree very well with

  15. Adaptive Delta Management: cultural aspects of dealing with uncertainty

    Science.gov (United States)

    Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan

    2016-04-01

    Hofstede's (1983) cultural dimensions, of which uncertainty avoidance and long-term orientation are of particular relevance for our analysis. Our conclusions comment on the suitability of approaches in Adaptive Delta Management rooted in different management theories are more suitable for specific delta countries than others. The most striking conclusion is the unsuitability of rational policy analytic approaches for The Netherlands. Although surprising this conclusion finds some support in the process dominated approach taken in the Dutch Delta Program. In addition, the divergence between Vietnam, Bangladesh and Myanmar, all located in South East Asia, is striking. References Hofstede, G. (1983). The cultural relativity of organizational practices and theories. Journal of international business studies, 75-89. Jos Timmermans, Marjolijn Haasnoot, Leon Hermans, Jan Kwakkel, Martine Rutten and Wil Thissen (2015). Adaptive Delta Management: Roots and Branches, IAHR The Hague 2015.

  16. High and low value fish chains in the Mekong Delta: challenges for livelihoods and governance

    NARCIS (Netherlands)

    Vo Thi Thanh Loc,; Bush, S.R.; Xuan Sinh, Le; Nguyen Tri Khiem,

    2010-01-01

    This paper investigates the structure, function and wealth distribution within the Pangasius hypophthalmus and Henicorhynchus spp./Labiobarbus spp. value chains in the Mekong Delta of Vietnam. The analysis is driven by key questions relating to the form and function of value chains, their contributi

  17. AB035. Thalassemia in Vietnam

    OpenAIRE

    Nguyen, Hoang Nam

    2015-01-01

    Thalassemia is a common inherited hemoglobin disorder in Vietnam. The alpha thalassemia, beta thalassemia, and HbE are popular in Vietnam but its variance depends on ethnics. The research for frequency of some ethnics almost in electrophoresis includes: Kinh (beta thalassemia carrier 1.49%, HbE 1.24%), Muong (beta thalassemia carrier 10.7%, HbE 11.7%), Tay (beta thalassemia carrier 11%, HbE 1%). In the recent years, we have conducted researches on thalassemia gene in the Northern and Southern...

  18. Charged current weak electroproduction of $\\Delta$ resonance

    CERN Document Server

    Alvarez-Ruso, L; Vacas, M J V

    1998-01-01

    We study the weak production of $\\Delta$ (i.e. $e^{-} + p \\to \\Delta^{0}+ energy range corresponding to the Mainz and TJNAF electron accelerators. The differential cross sections $\\sigma(\\theta)$ are found to be of the order of $ 10^{-39}$ cm$^2$/sr, over a range of angles which increases with energy. The possibility of observing these reactions with the high luminosities available at these accelerators, and studying the weak N-$\\Delta$ transition form factors through these reactions is discussed. The production cross section of N$^*(1440)$ in the kinematic region of $\\Delta$ production is also estimated and found to be small.

  19. Delta III—an evolutionary delta growth

    Science.gov (United States)

    Arvesen, R. J.; Simpson, J. S.

    1996-03-01

    In order to remain competitive in the future and expand the McDonnell Douglas Aerospace market share, MDA has developed an expendable launch system strategy that devices cost-effective launch systems from the Delta II with a growth vehicle configuration called Delta III. The Delta III evolves from the Delta II launch system through development of a larger payload fairing (4-meter diameter), new cryogenically propelled upper stage, new first stage fuel tank, and larger strap-on solid rocket motors. We are developing the Delta III using Integrated Product Development Teams that capitalize on the experience base that has led us to a world record breaking mission success of 49 consecutive Delta II missions. The Delta III first-launch capability is currently planned for the spring of 1998 in support of our first spacecraft customer, Hughes Space and Communications International.

  20. Data on Vietnam Era Veterans.

    Science.gov (United States)

    Veterans Administration, Washington, DC. Office of the Controller.

    Statistical data are presented on Vietnam era veterans for the following topics: employment status, medical status, compensation and pension, education, housing assistance, expenditures, and demographic information. The estimated number and age of veterans in civil life, categorized by sex and state, and the educational attainment of veterans at…

  1. The Vietnam Experience in Perspective.

    Science.gov (United States)

    Nurse, Ronald J.; Fleming, Dan B.

    1982-01-01

    Ten recent editions of secondary school-level United States history textbooks were analyzed to determine coverage and balance of the Vietnam War. Treatment of topics such as Vietnamese culture, the roles of wartime leaders, the aims of the United States government, the antiwar movement, and costs of the war are discussed. (PP)

  2. Universal service policy in Vietnam

    DEFF Research Database (Denmark)

    Do Manh, Thai; Falch, Morten; Von Salakpi, Simeon

    2016-01-01

    Universal service provision is a key to bridge the digital divide. This paper provides an empirical examination of the Vietnamese universal policy introduced in 2015 for implementation up to 2020. Using the framework of King et al. (1994) the paper analyses the universal services policy in Vietnam...

  3. Greening textile industry in Vietnam

    NARCIS (Netherlands)

    Nguyen Thi Phuong, L.

    2011-01-01

        The textile and garment industry has made a remarkable contribution to the economic development of Vietnam and employs currently a large labor force of 2.5 million people.However, the textile industry is also seen as a most polluting and unsustainable industry due to the use of exces

  4. Vietnam recommended dietary allowances 2007.

    Science.gov (United States)

    Khan, Nguyen Cong; Hoan, Pham Van

    2008-01-01

    It has been well acknowledged that Vietnam is undergoing a nutrition transition. With a rapid change in the country's reform and economic growth, food supply at the macronutrient level has improved. Changes of the Vietnamese diet include significantly more foods of animal origin, and an increase of fat/oils, and ripe fruits. Consequently, nutritional problems in Vietnam now include not only malnutrition but also overweight/obesity, metabolic syndrome and other chronic diseases related to nutrition and lifestyles. The recognition of these shifts, which is also associated with morbidity and mortality, was a major factor in the need to review and update the Recommended Dietary Allowances (RDA) for the Vietnamese population. This revised RDA established an important science-based tool for evaluation of nutrition adequacy, for teaching, and for scientific communications within Vietnam. It is expected that the 2007 Vietnam RDA and its conversion to food-based dietary guidelines will facilitate education to the public, as well as the policy implementation of programs for prevention of non-communicable chronic diseases and addressing the double burden of both under and over nutrition.

  5. Vulnerability in north- central Vietnam

    DEFF Research Database (Denmark)

    Casse, Thorkil; Milhøj, Anders; Nguyen, Thao Phuong

    2015-01-01

    This article examines changes in livelihood strategies in response to flooding. It does so on the basis of a household survey which was undertaken in three provinces in north central Vietnam. All households in the survey were regularly affected by flooding, but only poor households experience...

  6. Greening textile industry in Vietnam

    NARCIS (Netherlands)

    Nguyen Thi Phuong, L.

    2011-01-01

        The textile and garment industry has made a remarkable contribution to the economic development of Vietnam and employs currently a large labor force of 2.5 million people.However, the textile industry is also seen as a most polluting and unsustainable industry due to the use of

  7. Population dynamics of rice planthoppers, Nilaparvata lugens and Sogatella furcifera (Hemiptera, Delphacidae) in Central Vietnam and its effects on their spring migration to China.

    Science.gov (United States)

    Hu, G; Lu, M-H; Tuan, H A; Liu, W-C; Xie, M-C; McInerney, C E; Zhai, B-P

    2017-06-01

    Rice planthopper (RPH) populations of Nilaparvata lugens and Sogatella furcifera periodically have erupted across Asia. Predicting RPH population dynamics and identifying their source areas are crucial for the management of these migratory pests in China, but the origins of the migrants to temperate and subtropical regions in China remains unclear. In particular, their early migration to China in March and April have not yet been explored due to a lack of research data available from potential source areas, Central Vietnam and Laos. In this study, we examined the population dynamics and migratory paths of N. lugens and S. furcifera in Vietnam and South China in 2012 and 2013. Trajectory modeling showed that in March and April in 2012 and 2013, RPH emigrated from source areas in Central Vietnam where rice was maturing to the Red River Delta and South China. Early migrants originated from Southern Central Vietnam (14-16°N), but later most were from Northern Central Vietnam (16-19°N). Analysis of meteorological and light-trap data from Hepu in April (1977-2013) using generalized linear models showed that immigration increased with precipitation in Southern Central Vietnam in January, but declined with precipitation in Northern Central Vietnam in January. These results determined that the RPH originate from overwintering areas in Central Vietnam, but not from southernmost areas of Vietnam. Winter precipitation, rather than temperature was the most important factor determining the number of RPH migrants. Based on their similar population dynamics and low population densities in Central Vietnam, we further speculated that RPH migrate to track ephemeral food resources whilst simultaneously avoiding predators. Migrations do not seem to be initiated by interspecific competition, overcrowding or host deterioration. Nevertheless, S. furcifera establishes populations earlier than N. lugens South China, perhaps to compensate for interspecific competition. We provide new

  8. Agro-environmental determinants of avian influenza circulation: a multisite study in Thailand, Vietnam and Madagascar.

    Science.gov (United States)

    Paul, Mathilde C; Gilbert, Marius; Desvaux, Stéphanie; Andriamanivo, Harena Rasamoelina; Peyre, Marisa; Khong, Nguyen Viet; Thanapongtharm, Weerapong; Chevalier, Véronique

    2014-01-01

    Outbreaks of highly pathogenic avian influenza have occurred and have been studied in a variety of ecological systems. However, differences in the spatial resolution, geographical extent, units of analysis and risk factors examined in these studies prevent their quantitative comparison. This study aimed to develop a high-resolution, comparative study of a common set of agro-environmental determinants of avian influenza viruses (AIV) in domestic poultry in four different environments: (1) lower-Northern Thailand, where H5N1 circulated in 2004-2005, (2) the Red River Delta in Vietnam, where H5N1 is circulating widely, (3) the Vietnam highlands, where sporadic H5N1 outbreaks have occurred, and (4) the Lake Alaotra region in Madagascar, which features remarkable similarities with Asian agro-ecosystems and where low pathogenic avian influenza viruses have been found. We analyzed H5N1 outbreak data in Thailand in parallel with serological data collected on the H5 subtype in Vietnam and on low pathogenic AIV in Madagascar. Several agro-environmental covariates were examined: poultry densities, landscape dominated by rice cultivation, proximity to a water body or major road, and human population density. Relationships between covariates and AIV circulation were explored using spatial generalized linear models. We found that AIV prevalence was negatively associated with distance to the closest water body in the Red River Delta, Vietnam highlands and Madagascar. We also found a positive association between AIV and duck density in the Vietnam highlands and Thailand, and with rice landscapes in Thailand and Madagascar. Our findings confirm the important role of wetlands-rice-ducks ecosystems in the epidemiology of AI in diverse settings. Variables influencing circulation of the H5 subtype in Southeast Asia played a similar role for low pathogenic AIV in Madagascar, indicating that this area may be at risk if a highly virulent strain is introduced.

  9. Agro-environmental determinants of avian influenza circulation: a multisite study in Thailand, Vietnam and Madagascar.

    Directory of Open Access Journals (Sweden)

    Mathilde C Paul

    Full Text Available Outbreaks of highly pathogenic avian influenza have occurred and have been studied in a variety of ecological systems. However, differences in the spatial resolution, geographical extent, units of analysis and risk factors examined in these studies prevent their quantitative comparison. This study aimed to develop a high-resolution, comparative study of a common set of agro-environmental determinants of avian influenza viruses (AIV in domestic poultry in four different environments: (1 lower-Northern Thailand, where H5N1 circulated in 2004-2005, (2 the Red River Delta in Vietnam, where H5N1 is circulating widely, (3 the Vietnam highlands, where sporadic H5N1 outbreaks have occurred, and (4 the Lake Alaotra region in Madagascar, which features remarkable similarities with Asian agro-ecosystems and where low pathogenic avian influenza viruses have been found. We analyzed H5N1 outbreak data in Thailand in parallel with serological data collected on the H5 subtype in Vietnam and on low pathogenic AIV in Madagascar. Several agro-environmental covariates were examined: poultry densities, landscape dominated by rice cultivation, proximity to a water body or major road, and human population density. Relationships between covariates and AIV circulation were explored using spatial generalized linear models. We found that AIV prevalence was negatively associated with distance to the closest water body in the Red River Delta, Vietnam highlands and Madagascar. We also found a positive association between AIV and duck density in the Vietnam highlands and Thailand, and with rice landscapes in Thailand and Madagascar. Our findings confirm the important role of wetlands-rice-ducks ecosystems in the epidemiology of AI in diverse settings. Variables influencing circulation of the H5 subtype in Southeast Asia played a similar role for low pathogenic AIV in Madagascar, indicating that this area may be at risk if a highly virulent strain is introduced.

  10. The medical libraries of Vietnam--a service in transition.

    Science.gov (United States)

    Brennen, P W

    1992-07-01

    The medical libraries of Vietnam maintain high profiles within their institutions and are recognized by health care professionals and administrators as an important part of the health care system. Despite the multitude of problems in providing even a minimal level of medical library services, librarians, clinicians, and researchers nevertheless are determined that enhanced services be made available. Currently, services can be described as basic and unsophisticated, yet viable and surprisingly well organized. The lack of hard western currency required to buy materials and the lack of library technology will be major obstacles to improving information services. Vietnam, like many developing nations, is about to enter a period of technological upheaval, which ultimately will result in a transition from the traditional library limited by walls to a national resource that will rely increasingly on electronic access to international knowledge networks. Technology such as CD-ROM, Integrated Services Digital Network (ISDN), and satellite telecommunication networks such as Internet can provide the technical backbone to provide access to remote and widely distributed electronic databases to support the information needs of the health care community. Over the long term, access to such databases likely will be cost-effective, in contrast to the assuredly astronomical cost of building a comparable domestic print collection. The advent of new, low-cost electronic technologies probably will revolutionize health care information services in developing nations. However, for the immediate future, the medical libraries of Vietnam will require ongoing sustained support from the international community, so that minimal levels of resources will be available to support the information needs of the health care community. It is remarkable, and a credit to the determination of Vietnam's librarians that, in a country with a legacy of war, economic deprivation, and international isolation

  11. The Delta 2 launcher

    Science.gov (United States)

    Ousley, Gilbert W., Sr.

    1991-12-01

    The utilization of the Delta 2 as the vehicle for launching Aristoteles into its near Sun synchronous orbit is addressed. Delta is NASA's most reliable launch vehicle and is well suited for placing the present Aristoteles spacecraft into a 400 m circular orbit. A summary of some of the Delta 2 flight parameters is presented. Diagrams of a typical Delta 2 two stage separation are included along with statistics on delta reliability and launch plans.

  12. Mineral resources of Vietnam

    Directory of Open Access Journals (Sweden)

    Kušnír Imrich

    2000-06-01

    Full Text Available Vietnam je bohatý na nerastné suroviny, ktoré sa nachádzajú prevažne na severe krajiny. Ložiská bauxitov, fosfátov, vzácnych zemín (REE, majú svetový význam. Ale i zásoby celého radu ïalších surovín (ropy, uhlia, zlata, železných rúd, chromitu, cínu, ilmenitu, medi, grafitu, atï. sú významné, ekonomicky ažite¾né a ich potenciál je obrovský. Za uvedené nerastné bohatstvo je „zodpovednᓠrozmanitá geologická stavba krajiny. Taktiež i morfológia a klíma (vlhká, tropická prispeli ku vytvoreniu niektorých ložísk (bauxity v krasových priehlbniach, atï.. Súèasná produkcia, okrem ropy (3,5 Mt/rok, zahròuje: 10,7 Mt uhlia, 3,5 Mt chromitu, asi 1 000 kg zlata, grafitu, kaolínu a mnohé iné minerály. Napriek tomu, je banícky priemysel v porovnaní so surovinovou základòou slabo vyvinutý. K jeho rozvoju urèite prispeje i úèas zahranièných spoloèností, odnedávna prítomných pri prieskume a ažbe surovín urèených pre export. Okrem struèného úvodu do geológie krajiny, obsahuje tento èlánok krátky popis nerastného bohatstva Vietnamu.

  13. Investment climate in Vietnam: potentials and limitations

    OpenAIRE

    Nguyen Thi Hong Bach Lien; Shatokhina, Anastasia Olegovna

    2016-01-01

    Due to economic renovation in 1986, Vietnam has gained a number of convincing social-economic achievements. One of the factors determining the success of Vietnam's economy is the support of foreign direct investment. Thus, the study and analysis of the determinants, affecting the ability to attract foreign investment have become more practically oriented and necessary. The main purpose of the article is to clarify the definition of investment climate and its characteristics in Vietnam. The ar...

  14. China-Vietnam Friendship Bringing Light Tour

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>At the invitation of the Vietnam Union of Friendship Organizations (VUFO),a delegation headed by CPAFFC Vice President Feng Zuoku and composed of a medical team from Beijing Tongren Hospital made a"China-Vietnam Friendship Bringing Light Tour to Vietnam"from November 13 to 20,2009 and gave free cataract surgery to about 100 patients in Bac Giang Province.

  15. The First Chinese Emperor in Vietnam

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>Vietnam,a close neighbor of China,was influenced by the Chinese Culture for generations.In history,Vietnam had been under the administration and protection of ancient Chinese imperial court for a long period of time.The first Chinese emperor in Vietnam,who can be traced far back to Qin and Han dynasty,is referred to as the oldest emperor worldwide, His name was Zhao Tuo,

  16. [Vietnam and its population].

    Science.gov (United States)

    Veron, J

    1993-01-01

    80% rural. The population is concentrated in the Red River delta, the Mekong delta, and the southeastern region including Ho Chi Minh City. The 4 main cities are Ho Chi Minh City with 3.2 million inhabitants,. Hanoi with 1.1 million, Hai Phong with 456,000, and Da Nang with 371,000. Although internal migration has not yet assumed great weight, there has been some rural exodus and movement from poor to richer regions. The policy of population redistribution to reduce density in the Red River delta and central coastal plain and to control city growth has led to some movement. 88% of the population over 10 was literate in 1989. Almost 75% of the population over age 13 is economically active. 71% of the economically active population is employed in agriculture, 12% in industry, and 7% in commerce. If current growth trends continue, Viet Nam is projected to have a population of 80 million in 2000 and 96 million in 2014.

  17. Negative quantum interference between the electronic Raman scattering processes of CuO chains and CuO2 planes of heavily overdoped (Y, Ca)Ba2Cu3O(7-delta).

    Science.gov (United States)

    Masui, T; Limonov, M; Uchiyama, H; Tajima, S; Yamanaka, A

    2005-11-11

    We found a strong X-Y anisotropy of the pair-breaking peak in the Raman scattering of heavily overdoped (Y, Ca)Ba2Cu3O(7-delta) (T(c) = 65 K). The pair-breaking peak is radically suppressed in the YY-polarized spectrum. We ascribe this anomaly to the effect of quantum interference between the Raman processes of the CuO-chain and the CuO2-plane electronic excitations that might take place as a result of the increase in the transfer matrix due to overdoping.

  18. Vietnam and the regional crisis

    DEFF Research Database (Denmark)

    Masina, Pietro Paolo

    2002-01-01

    inflows, should be understood in the broader frame of regional contingencies, and not be simplistically explained as investors' discontent (i.e., in order to pressure Vietnamese authorities into implementing a more orthodox neo-liberal agenda). And in a post-crisis regional economic reorganisation......The paper explores the linkages between Vietnam and the regional economy before and after the East Asian financial crisis of 1997 and 1998, indicating that the country is more closely associated with the region than normally assumed. Thus, key indicators, such as falling foreign direct investment...... (including a restructuring of the so-called 'flying geese' pattern) Vietnam's chances of benefitting from closer integration in the world economy will depend on a clearcut industrial and trade policy, rather than on embarking a so-called 'neutral trade regime'. Preliminary evidence seems to indicate...

  19. Dilemmas in examining understanding of nature of science in Vietnam

    Science.gov (United States)

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2015-12-01

    Scholars proved nature of science (NOS) has made certain contributions to science teaching and learning. Nonetheless, what, how and how much NOS should be integrated in the science curriculum of each country cannot be a benchmark, due to the influence of culture and society. Before employing NOS in a new context, it should be carefully studied. In assessing views of NOS in Vietnam, a developing country with Eastern culture where the NOS is not consider a compulsory learning outcome, there are several issues that researchers and educators should notice to develop an appropriate instrument that can clearly exhibit a NOS view of Vietnamese. They may include: time for the survey; length, content, type, and terms of the questionnaire; Vietnamese epistemology and philosophy; and some other Vietnamese social and cultural aspects. The most important reason for these considerations is that a Vietnamese view of NOS and NOS assessment possibly differs from the Western ideas due to the social and cultural impact. As a result, a Western assessment tool may become less effective in an Eastern context. The suggestions and implications in this study were derived from a prolonged investigation on Vietnamese science teacher educators and student teachers of School of Education, at Can Tho University, a State University in Mekong Delta region, Vietnam.

  20. Dilemmas in examining understanding of nature of science in Vietnam

    Science.gov (United States)

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2017-06-01

    Scholars proved nature of science (NOS) has made certain contributions to science teaching and learning. Nonetheless, what, how and how much NOS should be integrated in the science curriculum of each country cannot be a benchmark, due to the influence of culture and society. Before employing NOS in a new context, it should be carefully studied. In assessing views of NOS in Vietnam, a developing country with Eastern culture where the NOS is not consider a compulsory learning outcome, there are several issues that researchers and educators should notice to develop an appropriate instrument that can clearly exhibit a NOS view of Vietnamese. They may include: time for the survey; length, content, type, and terms of the questionnaire; Vietnamese epistemology and philosophy; and some other Vietnamese social and cultural aspects. The most important reason for these considerations is that a Vietnamese view of NOS and NOS assessment possibly differs from the Western ideas due to the social and cultural impact. As a result, a Western assessment tool may become less effective in an Eastern context. The suggestions and implications in this study were derived from a prolonged investigation on Vietnamese science teacher educators and student teachers of School of Education, at Can Tho University, a State University in Mekong Delta region, Vietnam.

  1. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  2. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  3. Vietnam: The Political Economy of Education in a "Socialist" Periphery

    Science.gov (United States)

    London, Jonathan D.

    2006-01-01

    In this article I examine historic changes in the goals, conduct and outcomes of education policies in Vietnam from the 1940s to the present, under the Communist Party of Vietnam. Recent studies of Vietnam's education system centre on econometric and demographic analysis of education data dating back to the early 1990s, when Vietnam began an…

  4. Vietnam kan nieuwe bron voor kokkels worden

    NARCIS (Netherlands)

    Poelman, M.

    2012-01-01

    Wageningse onderzoekers gaan Vietnam helpen om de puntjes op de i te zetten bij hun monitoringsprogramma voor de voedselveiligheid van schaal- en schelpdieren, en ze bijscholen in risicomanagement en HACCP-audits. Want Vietnam wil graag de controles op visproductie verbeteren en meer kokkels, mossel

  5. Chinese Friendly Personages’ Delegation Visits Vietnam

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>A 50-member "Meeting at Uncle Ho’s Hometown" Chinese friendly personages’delegation led by Wang Yunze, vice president of the China-Vietnam Friendship Association (CVFA), paid a visit to Vietnam from May 15 to 23. Nguyen Minh Triet, Vietnamese president;

  6. Electronic structure of YBa/sub 2/Cu/sub 3/O/sub 7-//sub delta/ including strong correlation effects

    Energy Technology Data Exchange (ETDEWEB)

    Costa-Quintana, J.; Lopez-Aguilar, F.; Balle, S.; Salvador, R.

    1989-05-01

    The occupied and unoccupied valence-band density of states of YBa/sub 2/Cu/sub 3/O/sub 7-//sub delta/ is determined considering a coherent potential which includes the Coulomb intrasite d-d correlation. The p states tend to be all occupied and, as a consequence, the most localized d states with the XZ symmetry tend to be unoccupied giving rise to an upper Hubbard band. This picture is in good agreement with the direct and inverse photoemission spectroscopies.

  7. Crossover from coherent to incoherent electronic excitations in the normal state of Bi(2)Sr(2)CaCu(2)O(8+delta).

    Science.gov (United States)

    Kaminski, A; Rosenkranz, S; Fretwell, H M; Li, Z Z; Raffy, H; Randeria, M; Norman, M R; Campuzano, J C

    2003-05-23

    Angle resolved photoemission spectroscopy (ARPES) and resistivity measurements are used to explore the overdoped region of the high temperature superconductor Bi(2)Sr(2)CaCu(2)O(8+delta). We find evidence for a new crossover line in the phase diagram between a coherent metal phase, for lower temperatures and higher doping, and an incoherent metal phase, for higher temperatures and lower doping. The former is characterized by two well-defined spectral peaks in ARPES due to coherent bilayer splitting and superlinear behavior in the resistivity, whereas the latter is characterized by a single broad spectral feature in ARPES and a linear temperature dependence of the resistivity.

  8. Quality of antimicrobial products used in striped catfish (Pangasianodon hypophthalmus) aquaculture in Vietnam

    OpenAIRE

    Tran Minh Phu; Nguyen Thanh Phuong; Marie-Louise Scippo; Anders Dalsgaard

    2015-01-01

    Antimicrobial usage is common in Asian aquaculture. This study aimed to determine the quality of antimicrobial products used by Vietnamese striped catfish (Pangasianodon hypophthalmus) farmers. Twenty one antimicrobial products (11 products contained a single antimicrobial and 10 products contained a mixture of two different antimicrobials) commonly used by catfish farmers were obtained from so-called chemical shops located in the Mekong Delta, Vietnam. Ultra High Performance Liquid Chromatog...

  9. Toxic metal levels in children residing in a smelting craft village in Vietnam: a pilot biomonitoring study

    OpenAIRE

    Sanders, Alison P.; Miller, Sloane K.; Nguyen, Viet; Kotch, Jonathan B; Fry, Rebecca C.

    2014-01-01

    Background In Vietnam, environmental pollution caused by small-scale domestic smelting of automobile batteries into lead ingot is a growing concern. The village of Nghia Lo is a smelting craft village located roughly 25 km southeast of Hanoi in the Red River Delta. Despite the concern of toxic metal exposure in the village, biomonitoring among susceptible populations, such as children, has not been previously conducted. The aim of this study was to determine the body burden of toxic metals in...

  10. Impact of insecticide-treated nets on wild pyrethroid resistant Anopheles epiroticus population from southern Vietnam tested in experimental huts

    OpenAIRE

    Trung Ho; Speybroeck Niko; Berkvens Dirk; Chinh Vu; Van Bortel Wim; Coosemans Marc

    2009-01-01

    Abstract Background In this study, the efficacy of insecticide-treated nets was evaluated in terms of deterrence, blood-feeding inhibition, induced exophily and mortality on a wild resistant population of Anopheles epiroticus in southern Vietnam, in order to gain insight into the operational consequences of the insecticide resistance observed in this malaria vector in the Mekong delta. Method An experimental station, based on the model of West Africa and adapted to the behaviour of the target...

  11. Freshwater aquaculture nurseries and infection of fish with zoonotic trematodes, Vietnam.

    Science.gov (United States)

    Phan, Van Thi; Ersbøll, Annette Kjær; Nguyen, Thanh Thi; Nguyen, Khue Viet; Nguyen, Ha Thi; Murrell, Darwin; Dalsgaard, Anders

    2010-12-01

    Residents of the Red River Delta region of northern Vietnam have a long tradition of eating raw fish. Fish-borne zoonotic trematodes (FZTs) are estimated to infect ≈1 million persons in Vietnam. It remains uncertain at what stages in the aquaculture production cycle fish become infected with FZTs. Newly hatched fish (fry) from 8 hatcheries and juveniles from 27 nurseries were therefore examined for FZT infection. No FZTs were found in fry from hatcheries. In nurseries, FZT prevalence in juveniles was 14.1%, 48.6%, and 57.8% after 1 week, 4 weeks, and when overwintered in ponds, respectively. FZT prevalence was higher in grass carp (paquaculture management practices, particularly in nurseries, to minimize the risk of distributing infected juveniles to grow-out ponds and, subsequently, to markets for human consumption.

  12. U.S.-Vietnam Relations in 2010: Current Issues and Implications for U.S. Policy

    Science.gov (United States)

    2010-08-06

    U.S.-Vietnam Economic and Trade Relations: Issues for the 111th Congress, by Michael F. Martin. 18 Peru and Australia are the other two countries...plan emphasized lighter industries such as foodstuffs, textiles , and electronics. According to some sources, many if not most of Vietnam’s SOEs are

  13. Stellar delta matter with delta-meson coupling constants constrained by QCD sum rule

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Antonio Ferreira da [Secretaria de Educacao, Cultura e Desportos do Estado de Roraima (SECD/RR), Boa Vista, RR (Brazil); Oliveira, Jose Carlos Teixeira de [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil); Rodrigues, Hilario [Centro Federal de Educacao Tecnologica (CEFET-RJ), Rio de Janeiro, RJ (Brazil); Duarte, Sergio Barbosa [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Chiapparini, Marcelo [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

    2010-07-01

    The considerable presence of delta-resonances (30% of baryonic population) in the dense phase of relativistic heavy ion collisions leads to a great interest in the study of the delta matter formation in the deep interior of compact stars. In the present work we determine the equation of state and the population of baryons and leptons and discuss the effects of the baryon-meson coupling constants to the formation of delta matter in the stellar medium. We use the non-linear Walecka model consisting of the octet of baryons of spin 1=2 (n, p, {Lambda}{sup 0}, {Sigma}{sup -}, {Sigma}{sup 0}, {Sigma}{sup +}, {Xi}{sup -}, {Xi}{sup 0}) and baryonic resonances of spin 3=2, represented by the delta resonances ({Delta}{sup -}, ({Delta}{sup 0}, ({Delta}{sup +}, ({Delta}{sup ++}) and {Omega}{sup -}, in the baryonic sector. In the leptonic sector we consider the electrons and muons. The coupling constants between the hyperons {Lambda}, {Sigma}, and {Xi} and the mesons {omega} and {rho} are fixed by using SU(6) symmetry, while the hyperons-{sigma} coupling constants are constrained by the consistence of the hypernuclear potential in the nuclear matter with hypernuclear data. In addition, we use the finite density QCD sum rule to determine the possible values of delta-meson coupling constants. (author)

  14. Cancer incidence in Australian Vietnam veterans

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, E.; Horsley, K. [Australian Government Department of Veterans' Affairs (Australia); Hoek, R. van der [Australian Institute of Health and Welfare (Australia)

    2004-09-15

    Australian Defence Force (ADF) personnel participated in the Vietnam Conflict from 1962 to 1973, involving nearly 60,000 personnel, of whom over 500 died during service and 3131 were severely physically wounded. Service in the Vietnam conflict presented distinct health challenges. Besides the hazards of combat conditions for extended periods, herbicides and other toxic chemicals were used extensively. The United States military sprayed more than 76,000,000L of herbicide over Vietnam in their Air Force Ranch Hand and Operation Trail Dust programs. The most heavily used herbicide was Agent Orange, contaminated with 2,3,7,8-tetrachlorodibenzo-pdioxin. Since the Vietnam conflict, ex-Service organisations (ESOs) have maintained that Vietnam service adversely affected the health of veterans. Initial studies showed no excess risk attributable to their service. However, more recent studies have shown that Vietnam veterans have excess incidence and mortality rates from several conditions such as cancers and heart disease. This paper describes the first cancer incidence study for all ADF Vietnam veterans.

  15. Gap distributions and spatial variation of electronic states in superconducting and pseudogap states of Bi{sub 2}Sr{sub 2}Ca{sub 2}CuO{sub 8+{delta}}

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, K.K.; Pasupathy, A.; Pushp, A. [Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Ono, S.; Ando, Y. [Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511 (Japan); Yazdani, A. [Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States)], E-mail: yazdani@princeton.edu

    2007-09-01

    High-resolution scanning tunneling microscopy has been used to study the tunneling density of states in lightly underdoped samples of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}Ca{sub 2}CuO{sub 8+{delta}} in both the superconducting and pseudogap states. We demonstrate that the tunneling gaps observed in these two states have identical spatial distributions and correlation lengths. This observation suggests that the two gaps, and hence the two phenomena, cannot have a competing origin. In addition, we present measurements that show that in contrast to the superconducting state, in which low energy quasi-particles are homogenous in real space, the states near the Fermi level are spatially inhomogeneous in the pseudogap state. The variation of the low-energy electronic states is spatially correlated with local changes in the pseudogap.

  16. Building an Extension Network in Vietnam.

    Science.gov (United States)

    Poussard, H.

    1999-01-01

    Agricultural extension in Vietnam is in transition as the economy moves to a market orientation. The national extension service created in 1993 is constrained by lack of funding, staff, and access to current extension knowledge. (SK)

  17. 2009 China-Vietnam Border Friendship Gala

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>International dragon boat races at sea, youth ex- changes, art performances and a symbolic friendship tree plant- ing ceremony were among the many colourful activities held during the 2009 China-Vietnam

  18. Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2005-09-01

    Full Text Available The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions. One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam, the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland. The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sediment transport, and the long-term morphodynamics of the river outlets. Salinity and water level are also discussed, the latter also in the context of the anticipated global effect of accelerated sea level rise. The analysis shows that the climatic and environmental conditions associated with geographical zones give rise to fundamental differences in the generation and dynamic evolution of the river mouths.

  19. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    'electronic signature' means data attached to, incorporated in, or logically ... See Cwele v S 2012 4 All SA 497 (SCA); Mohlabeng v Minister of Safety and Security ... ZAKZPHC 51 (2 September 2010); Delta Finance, a Division of Wesbank, ...

  20. Rotifers from Thuy Tien lake and Nhu Y river in central Vietnam, with a description of Ploesoma asiaticum new species (Rotifera: Monogononta

    Directory of Open Access Journals (Sweden)

    Mau Trinh Dang

    2013-08-01

    Full Text Available We surveyed Thuy Tien lake and Nhu Y river, Thua Thien Hue province, Vietnam, for rotifers from March to August 2010, and additionally in February 2012 in Thuy Tien lake. A total of 98 species-level taxa are identified, belonging to 31 genera and 21 families. Of there, 52 are first records for Vietnam, Filinia minuta (Smirnov, 1928 is new to the Oriental region and Ploesoma asiaticum n. sp. is new to science. These results increase the rotifer record for Vietnam from 122 to 174 taxa. In addition to describing the new taxon, we provide comparative illustrations including trophi scanning electron microscopy photographs of Ploesoma hudsoni (Imhof 1891.

  1. Vietnam and ASEAN: Should They Integrate?

    Science.gov (United States)

    2013-11-01

    into ASEAN and its trade liberalization policies. Despite Vietnam’s compliance with the Common Effective Preferential Tariff (CEPT) Scheme in the... Preferential Tariff (CEPT) Scheme in the ASEAN Free Trade Area (AFTA), Vietnam’s use of non-tariff barriers conflicts with ASEAN policies. Vietnam uses...a full member of ASEAN, Vietnam agreed to fulfill the mandates, policies and agreements of the ASEAN Free Trade Area (AFTA). 6 AFTA facilitates

  2. Computational assessment of the electronic structures of cyclohexa-1,2,4-triene, 1-oxacyclohexa-2,3,5-triene (3delta(2)-pyran), their benzo derivatives, and cyclohexa-1,2-diene. An experimental approach to 3delta(2)-pyran.

    Science.gov (United States)

    Engels, Bernd; Schöneboom, Jan C; Münster, Arno F; Groetsch, Stefan; Christl, Manfred

    2002-01-16

    The six-membered cyclic allenes given in the title have been studied theoretically by means of an MR-CI approach. For all compounds, the allene structures were found to be the ground states in the gas phase. In the cases of cyclohexa-1,2-diene (1), the isobenzene 2, and the isonaphthalene 7, the most stable structures having a planar allene moiety are the diradicals 1b, 2b, and 7b, representing the transition states for the racemization of 1a, 2a, and 7a and being less stable than the latter by 14.1, 8.9, and 11.2 kcal/mol, respectively. At variance with this order, the 3delta(2)-pyran 4 and the chromene 5 have the zwitterions 4c and 5c as the most stable planar structures, which lie only 1.0 and 5.4 kcal/mol above 4a and 5a, respectively. According to the simulation of the solvent effect, 4c even becomes the ground state of 4 in THF solution. The frontier orbitals of the respective states of 2 and 4 suggest different rates and sites for the reaction with nucleophiles. For the first time, the pyran 4 has been generated and trapped. As a precursor for 4, 3-bromo-4H-pyran (9) was chosen, the synthesis of which was achieved on two routes from 4H-pyran. The treatment of 9 with potassium tert-butoxide (KOt-Bu)/18-crown-6 gave 4-tert-butoxy-4H-pyran as the only discernible product, whether styrene or furan was present, indicating the interception of 4 by KOt-Bu. Finally, the disagreement between the experiment and the theory concerning the heat of formation and the electronic nature of the isobenzene 2 is resolved by demonstrating that the experimental data can provide only an upper limit of the DeltaH(f) degrees value.

  3. Paragonimus and paragonimiasis in Vietnam: an update.

    Science.gov (United States)

    Doanh, Pham Ngoc; Horii, Yoichiro; Nawa, Yukifumi

    2013-12-01

    Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.

  4. Delta hedging strategies comparison

    DEFF Research Database (Denmark)

    De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.

    2008-01-01

    In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model ...

  5. Potential Economic Impacts of the Vietnam-Korea Free Trade Agreement on Vietnam

    Directory of Open Access Journals (Sweden)

    Thanh Hoan Phan

    2016-03-01

    Full Text Available This paper provides an assessment of the potential economic impacts of the Vietnam-Korea free trade agreement on Vietnam, by using general equilibrium modeling. The results show that Vietnam-Korea FTA will increase aggregate welfare for both countries in the long run. The most important gains accrue from better allocation of resources consequent to trade liberalization. All the sectoral differences and changes are consistent with the trade profiles of the two countries, and the long-run results are more pronounced than those of the short-run. In comparison with other ASEAN countries, the CGE analysis suggests that Vietnam's agriculture exports to Korea would especially rise in the long run. However, there will be strong competition in this sector among ASEAN members. Thus, an earlier conclusion of a comprehensive FTA with Korea is expected to be a good strategy for Vietnam, so as to avoid the direct competition with ASEAN members in the future.

  6. Horizontal Symmetries $\\Delta(150)$ and $\\Delta(600)$

    CERN Document Server

    Lam, C S

    2013-01-01

    Using group theory of mixing to examine all finite subgroups of SU(3) with an order less than 512, we found recently that only the group $\\Delta(150)$ can give rise to a correct reactor angle $\\th_{13}$ of neutrino mixing without any free parameter. It predicts $\\sin^22\\th_{13}=0.11$ and a sub-maximal atmospheric angle with $\\sin^22\\th_{23}=0.94$, in good agreement with experiment. The solar angle $\\th_{12}$, the CP phase $\\d$, and the neutrino masses $m_i$ are left as free parameters. In this article we provide more details of this case, discuss possible gain and loss by introducing right-handed symmetries, and/or valons to construct dynamical models. A simple model is discussed where the solar angle agrees with experiment, and all its mixing parameters can be obtained from the group $\\Delta(600)$ by symmetry alone. The promotion of $\\Delta(150)$ to $\\Delta(600)$ is on the one hand analogous to the promotion of $S_3$ to $S_4$ in the presence of tribimaximal mixing, and on the other hand similar to the extens...

  7. Industrial Clustering Policy and Economic Restructuring in Vietnam

    OpenAIRE

    Pham, Thi Thanh Hong; Nguyen, Binh Giang

    2012-01-01

    This paper reviews the industrial agglomeration and evaluates the industrial clustering policy in Vietnam. Base on the Kuchiki flowchart on the building of industrial clustering policy for developing countries, the authors suggest a policy framework for Vietnam.

  8. Soil knowledge for farmers, farmer knowledge for soil scientists : the case of acid sulphate soils in the Mekong delta, Viet Nam

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.

    1996-01-01


    Half the Mekong delta in Vietnam, i.e. around 2 million hectares, suffers soil related problems due to acid sulphate soils. These soils generate sulphuric acid due to the oxidation of pyrite after aeration. Pyrite is most easily formed in tidal swamps. Human interference through land

  9. Integrated soil and water management in acid sulphate soils. Balancing agricultural production and environmental requirements in the Mekong Delta, Viet Nam.

    NARCIS (Netherlands)

    Le Quang Minh,

    1996-01-01

    The objectives of this study in the Mekong delta, Vietnam, were: (1) to obtain a better understanding of the effects of soil physical properties and flow types on solute transport in ASS emphasing aluminum; (2) to quantify environmental hazards resulting from amelioration activities in acid sulphate

  10. Integrated soil and water management in acid sulphate soils : balancing agricultural production and environmental requirements in the Mekong Delta, Viet Nam

    NARCIS (Netherlands)

    Le, Q.M.

    1996-01-01


    The objectives of this study in the Mekong delta, Vietnam, were: (1) to obtain a better understanding of the effects of soil physical properties and flow types on solute transport in ASS emphasing aluminum; (2) to quantify environmental hazards resulting from amelioration activities in

  11. Soil knowledge for farmers, farmer knowledge for soil scientists. The case of acid sulphate soils in the Mekong delta, Viet Nam.

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.

    1996-01-01

    Half the Mekong delta in Vietnam, i.e. around 2 million hectares, suffers soil related problems due to acid sulphate soils. These soils generate sulphuric acid due to the oxidation of pyrite after aeration. Pyrite is most easily formed in tidal swamps. Human interference through land drainage is the

  12. U.S.-Vietnam Military Relations: Game Theory Perspective

    Science.gov (United States)

    2012-06-01

    13 Andrew X. Pham, Catfish and Mandala : A Two-Wheeled Voyage through the Landscape and Memory of Vietnam...140. 17 Karnow, Vietnam: A History, 141; Pham, Catfish and Mandala , 229. 10 U.S. Prisoners of War/Missing in Action (POW/MIAs).18 Vietnam did not...22, 2011. Pham, Andrew X. Catfish and Mandala : A Two-Wheeled Voyage through the Landscape and Memory of Vietnam, Picador, New York, 1999. Phong

  13. Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    As a Party to the United Nations Framework Convention on Climate Change (UNFCCC) Viet Nam will make its strong effort to implement the UNFCCC through effective activities in order to reduce GHG emissions as well as enhance carbon sinks in the country. The UNEP/GEF Project `Economics of GHG Limitation - Phase 1: Establishment of a Methodological Framework for Climate Change Mitigation Assessment` developed by the UNEP Collaborating Centre on Energy and Environment (UCCEE) in cooperation with Lawrence Berkeley Laboratory has been deployed in Viet Nam since 1996. The project deals with GHG mitigation analysis and options, focusing on the main issues: a) Associated macro-economics, b) Energy, c) Land use and forestry. For this study, a number of different data related to energy, industry, forestry and agriculture sectors as well as Viet Nam socio-economic development up to the year 2030, are collected. Besides, several models such as MEDEE-S, EFOM-ENV, COMAP are applied for development and assessment of GHG mitigation options in the next decades. The MEDEE-S and EFOM-ENV models are used as a tool for determining the cost-effective strategies to abate GHG emissions for energy sector while COMAP model is applied for forestry sector. (au) 39 refs.

  14. 78 FR 7452 - Steel Wire Garment Hangers From Vietnam; Determinations

    Science.gov (United States)

    2013-02-01

    ... COMMISSION Steel Wire Garment Hangers From Vietnam; Determinations On the basis of the record \\1\\ developed... imports of steel wire garment hangers from Vietnam, provided for in subheading 7326.20.00 of the... countervailing and antidumping duty orders on steel wire garment hangers from Vietnam. Background The...

  15. Framework for Naval Cooperation between Vietnam and the United States

    Science.gov (United States)

    2017-06-09

    the Vietnam-United States relationship has taken giant steps forward in virtually every aspect, especially solidified by a Comprehensive Partnership... platform for future relationship between Vietnam and the United States. Finally, this research suggests a framework for naval cooperation between Vietnam...United States relationship has taken giant steps forward in virtually every aspect, especially solidified by a Comprehensive Partnership Agreement signed

  16. On the width of N-Delta and Delta-Delta states

    CERN Document Server

    Niskanen, J A

    2016-01-01

    It is seen by a coupled-channel calculation that in the two-baryon N-Delta or Delta-Delta system the width of the state is greatly diminished due to the relative kinetic energy of the two baryons, since the internal energy of the particles, available for pionic decay, is smaller. A similar state dependent effect arises from the centrifugal barrier in N-Delta or Delta-Delta systems with non-zero orbital angular momentum. The double-Delta width can become even smaller than the free width of a single Delta. This has some bearing to the interpretation of the d'(2380) resonance recently discovered at COSY.

  17. The Lessons of the Vietnam War: Unit 13. Teacher's Manual: Strategies and Resources for Teaching the Vietnam War.

    Science.gov (United States)

    Center for Social Studies Education, Pittsburgh, PA.

    This teacher's manual is designed to accompany the curriculum "The Lessons of the Vietnam War." For each of 12 units of the curriculum, this manual suggests projects for student research and classroom activities. The 12 units are entitled: (1) Introduction to Vietnam: land, history and culture; (2) America at war in Vietnam: decisions and…

  18. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam

    Science.gov (United States)

    Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano

    2017-01-01

    Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with ‘King’ mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch’s postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on ‘Carrizo’ citrange (C. sinensis ‘Washington Navel’ x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity. PMID:28208159

  19. Entry modes of European firms in Vietnam

    Directory of Open Access Journals (Sweden)

    Daniel Simonet

    2012-09-01

    Full Text Available Purpose: The purpose of the paper is to explore the entry modes of EU firms setting up operations in Vietnam. Design/methodology/approach: we use a case study approach on Haymarket, Cadbury, Creative Education, Fairchild, Aventis and Artemisinin and Farming International using interviews from managerial professionals in Vietnam. Findings: Despite the fact that Vietnam has been opening up for more than 20 years, licensing is the preferred entry mode because of the risks involved in venturing with local firms; that preference signals a low level commitment and a high perception of risk and state interference. In line with Vietnam transition to state - rather than private market - capitalism, a foreign company opting for a joint-venture will do so with a state-owned rather than privately-owned company. The choice of a subsidiary can be explained by the lack of trust in partners and institutions, not by improvement in the socio-political environment. Limitations: In determining the entry mode strategy, the paper focuses on the Uppsala school’s “psychic distance” (e.g. cultural distance, lack of trust rather than on firm-specific advantages (Rugman, 1980; 2006. Key-words: international entry mode; emerging markets; subsidiary; joint-venture; India; Vietnam

  20. geomorphology_delta

    Data.gov (United States)

    California Department of Resources — Surficial geology of the Delta area of California by Brian Atwater of the U.S. Geological Survey. Source maps are from the USGS publication MF-1401. This digital...

  1. Delta-Reliability

    OpenAIRE

    Eugster, P.; Guerraoui, R.; Kouznetsov, P.

    2001-01-01

    This paper presents a new, non-binary measure of the reliability of broadcast algorithms, called Delta-Reliability. This measure quantifies the reliability of practical broadcast algorithms that, on the one hand, were devised with some form of reliability in mind, but, on the other hand, are not considered reliable according to the ``traditional'' notion of broadcast reliability [HT94]. Our specification of Delta-Reliability suggests a further step towards bridging the gap between theory and...

  2. Selectively delta-doped Al(x)Ga(1-x)As/GaAs heterostructures with high two-dimensional electron-gas concentrations (n2DEG) of not less than 1.5 x 10 to the 12th/sq cm for field-effect transistors

    Science.gov (United States)

    Schubert, E. F.; Cunningham, J. E.; Tsang, W. T.; Timp, G. L.

    1987-10-01

    Selectively delta-doped heterostructures in the Al(x)Ga(1-x)As/GaAs material system, combining the delta-doping and selectively doped heterostructure concepts, are considered. From Shubnikov-de Haas measurements, two-dimensional electron-gas concentrations of 1.1 x 10 to the 12th/sq cm at 300 mK and at a spacer thickness of 25 A are found, and it is suggested that such high values are due to size quantization in Al(x)Ga(1-x)As and the localization of donor impurities within one atomic monolayer. Selectively delta-doped heterostructure transistors are fabricated, showing a transconductance of about 360 mS/mm at a gate length of 1.2 microns and a temperature of 300 K.

  3. Technique de lombriculture au Sud Vietnam

    Directory of Open Access Journals (Sweden)

    Haubruge E.

    2003-01-01

    Full Text Available Vermicomposting technique in South Vietnam. Earthworms play a major role in organic matter transformation. The vermicomposting allows to combine several advantages: the management of diversified organic wastes, and the production of earthworms and vermicompost. Crop residues and other plant wastes mixed with animal manure from individual farms can be used. In South Vietnam, farmers are rearing some livestock and growing a few number of crop species. From several years, an increasing number of vermicomposting units were set in many farms from the Ho Chi Minh City region. Two kinds of infrastructure materials are used: baked clay blocks or bamboo stems with plastic covers. In South Vietnam, all conditions are pooled to ensure an efficient earthworm production: suitable climate, available organic wastes and materials to build the vermicomposting structures. Both field plot fertility and protein feed for livestock (pigs, poultry, etc. can be provided by rearing earthworms.

  4. Lightning protection for wind turbines in Vietnam

    Directory of Open Access Journals (Sweden)

    Thuan Nguyen

    2017-01-01

    Full Text Available Wind energy has become increasingly important in the total electrical energy supply mix in Vietnam over the last few years. Small, kW turbines were installed in isolated areas a decade ago, while wind farms of several MW to few hundred MW are now being connected directly to national grid, with many additional projects in planning or under construction to fulfill an objective of 6% of the total installed capacity by 2030 (approximately 6200 MW of wind energy component. The increase in wind farm generation results in increased damage from lightning. In this paper, the annual frequency of lightning strikes to wind turbines in Vietnam is calculated using electrogeometric model. Reported lightning incidents to three major wind farms in Vietnam are summarized. Possible causes of failure are discussed, and an EMTP simulation for each incident was performed accordingly. The simulations suggest the failure mechanisms as well the potential of improved grounding to reduce lightning induced damage in future windfarms.

  5. [Health and health care in Vietnam].

    Science.gov (United States)

    Flessa, S

    2003-05-01

    The South East Asian state of Vietnam is currently undergoing a transition from a centralised socialism to a so-called socialist market economy strongly promoting the private sector. For the last 17 years economy experienced an impressive growth. If the assumption is true that economic growth is positively correlated with the health status of the population, the strengthened economy of Vietnam must go along with an improved health situation and health care system of this country. The following paper evaluates this assumption. It is demonstrated that there is indeed a strongly positive correlation between health and development in many aspects. However, it becomes obvious that economic growth is definitely accompanied by increasing regional and social disparity challenging the health care policy of Vietnam and her international partners.

  6. Tetanus in Southern Vietnam: Current Situation

    Science.gov (United States)

    Thuy, Duong Bich; Campbell, James I.; Thanh, Tran Tan; Thuy, Cao Thu; Loan, Huynh Thi; Hao, Nguyen Van; Minh, Yen Lam; Tan, Le Van; Boni, Maciej F.; Thwaites, C. Louise

    2017-01-01

    In Vietnam, there are no accurate data on tetanus incidence to allow assessment of disease burden or vaccination program efficacy. We analyzed age structure of 786 tetanus cases admitted to a tertiary referral center in Vietnam for three separate years during an 18-year period to examine the impact of tetanus prevention programs, namely the Expanded Program on Immunization (EPI) and the Maternal and Neonatal Tetanus (MNT) initiative. Most cases were born before the initiation of EPI. Median age increased from 33 (interquartile range: 20–52) in 1994, to 46 (32–63) in 2012 (P anti-tetanus antibody compared with 24.4% (95% CI: 15.9–34.7%) of men, indicating continued tetanus vulnerability in older men in Vietnam. PMID:27821690

  7. The role of trade unions in Vietnam

    DEFF Research Database (Denmark)

    Torm, Nina Elisabeth

    2014-01-01

    On the basis of matched employer–employee data from 2007 to 2009, this paper examines the union wage gap among small and medium non-state manufacturing enterprises in Vietnam. Controlling for both worker and firm characteristics, the results provide evidence that union members earn higher wages...... than non-members, and are more likely to receive social benefits.Within unionised firms, a substantial wage premium is revealed for workers employed in Southern firms, a finding which among other factors may be attributed to historical differences between the North and South of Vietnam....

  8. The 2003 Merged Model for Vietnam

    DEFF Research Database (Denmark)

    Jensen, Henning Tarp; Tarp, Finn

    This monograph documents the 2003 Merged Model for Vietnam. The initialization and calibration of the model is based on a financial 2003 SAM framework and an auxiliary 2002-3 data set. The recursive nature of the solution of the Merged Model is discussed with reference to the four main sectors...... domestic credit, private domestic credit, and private net foreign debt, are discussed with reference to historical time series data. Accordingly, the current monograph facilitates the future implementation of the Merged Model for Vietnam by going through the main considerations necessary...

  9. English in Vietnam and Its Features

    Institute of Scientific and Technical Information of China (English)

    李琼璐; 张婷

    2014-01-01

    English spoken by people from different countries takes on different characteristics. Many linguists conducted researches on World Englishes. Focusing on the pronunciation,grammar, vocabulary and literature achievement, these studies present the target English’s environment and features. However,there is rare achievement of study.in English in Vietnam. Under the economy boom, Vietnamese government attached importance to the English education, which led to the wide utilization of English. This article analyzes English in Vietnam and its features,including pronunciation, grammar and vocabulary, in the hope of making complements to world Englishes.

  10. English in Vietnam and Its Features

    Institute of Scientific and Technical Information of China (English)

    李琼璐; 张婷

    2014-01-01

    English spoken by people from different countries takes on different characteristics. Many linguists conducted researches on World Englishes. Focusing on the pronunciation, grammar, vocabulary and literature achievement, these studies present the target English's environment and features. However, there is rare achievement of study.in English in Vietnam. Under the economy boom, Vietnamese government attached importance to the English education, which led to the wide utilization of English. This article analyzes English in Vietnam and its features , including pronunciation, grammar and vocabulary, in the hope of making complements to world Englishes.

  11. Vietnam anthracite - current situation and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Doan van Kien [Vietnam National Coal Corporation (Vietnam)

    2004-07-01

    A resume is given of Vietnam's resources of anthracite, sub-bituminous coal, peat, coking coal and brown coal. Details are given of anthracite produced by the Vietnam National Coal Corporation (VINACOAL). Sales, coal quality and markets are discussed. Markets include the steel, non-ferrous metal and cement industries, power generation, water treatment and electrode and calcium carbide manufacture. VINACOAL is aiming to increase anthracite production especially for PCI, and is investing in coal mining and coal preparation plants and expansion of Cam Pha port. A series of eight slides/overheads accompanies the presentation (file Doan van Kien.pdf).

  12. 78 FR 55676 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Preliminary Results of the...

    Science.gov (United States)

    2013-09-11

    ... calculated in accordance with section 772 of the Act. Because Vietnam is a non-market economy (``NME... Countervailing Duty Centralized Electronic Service System (``IA ACCESS''). IA ACCESS is available to registered... discussion of this practice, see Non-Market Economy Antidumping Proceedings: Assessment of Antidumping Duties...

  13. The United States and Vietnam Relationship: Benefits and Challenges for Vietnam

    Science.gov (United States)

    2016-06-10

    and security, protection and promotion of human rights, and culture, sports, and tourism .33 When it comes to political and diplomatic relations, the...Stern and Walter Lohman, the Heritage Foundation think tank, believe that, at present, the U.S. and Vietnam have mutual, though not identical ...interests in mitigating the negative impacts of China’s rise. Closer defense cooperation between the U.S. and Vietnam is in the interests of both

  14. Essential oils from five species of Annonaceae from Vietnam.

    Science.gov (United States)

    Thang, Tran D; Dai, Do N; Hoi, Tran M; Ogunwande, Isiaka A

    2013-02-01

    The essential oils obtained by hydrodistillation from the leaves of five species of Annonaceace grown in Vietnam were analyzed by gas chromatography (GC) coupled with mass spectrometry (GC/MS). The main constituents of Artabotrys hongkongensis Hance were the sesquiterpenes spathulenol (13.1%), beta-caryophyllene (6.6%), gamma-elemene (6.3%) and delta-cadinene (6.3%). beta-Caryophyllene (12.1%), bicycloelemene (11.2%) and bicyclogermacrene (11.6%) were the predominant components of the oil of Melodorum fruticosum Lour, whereas the oil of Polyalthia longifolia var. pendula Hort was comprised mainly of beta-caryophyllene (30.0%), alpha-zingiberene (21.7%), aromadendrene (15.2%) and beta-selinene (9.1%). The main constituents of Fissistigma maclurei Merr. were germacrene D (26.1%), alpha-terpinene (8.2%), spathulenol (10.0%), and bicyclogermacrene (6.6%), while alpha-santalene (14.3%), beta-caryophyllene (6.3%), terpinen-4-ol (6.3%), caryophyllene oxide (5.7%), trans-alpha-bergamotene (5.3%) and allo-ocimene (5.3%) were identified in significant quantity from Fissistigma rufinerve (Hook.f. & Thomson) Merr.

  15. {\\delta}M Formalism

    CERN Document Server

    Talebian-Ashkezari, Alireza; Abolhasani, Ali Akbar

    2016-01-01

    We study the evolution of the "non-perturbative" metric perturbations in a Bianchi background in the long-wavelength limit. By applying the gradient expansion to the equations of motion we exhibit a generalized "Separate Universe" approach to the cosmological perturbation theory. Having found this consistent separate universe picture, we introduce the "{\\delta}M formalism" for calculating the evolution of the tensor perturbations in anisotropic inflation models in almost similar way as the so-called {\\delta}N formula for the super-horizon dynamics of the curvature perturbations. Likewise its ancestor, {\\delta}N formalism, this new method can substantially reduce the amount of calculations related to the evolution of the tensor modes.

  16. 77 FR 55186 - Executive-Led Indonesia Vietnam Infrastructure Business Development Mission Statement...

    Science.gov (United States)

    2012-09-07

    ... International Trade Administration Executive-Led Indonesia Vietnam Infrastructure Business Development Mission...-Led Indonesia Vietnam Infrastructure Business Development Mission Statement, 77 FR, No. 131, July 9... Applications section of the Notice of the Indonesia Vietnam Infrastructure Business Development Mission...

  17. Land Titles and Rice Production in Vietnam

    DEFF Research Database (Denmark)

    Van Den Broeck, Katleen; Newman, Carol; Tarp, Finn

    In most of the empirical literature on land titling, the household is regarded as unitary, and land rights are found to have ambiguous effects on land allocation, investment and productivity. Using data from 12 provinces in Vietnam, we diversify land titles, and show in a household fixed effects ...

  18. Health utilities of hypertensive patients in Vietnam

    NARCIS (Netherlands)

    Nguyen, T.P.; Postma, M.J.; Veninga, Catharina

    2015-01-01

    Objectives: With a lack of an essential evidence on utilities to support cost-effectiveness analysis of hypertension management in Vietnam, we aimed to gather data on health utilities for hypertensive patients and identify predictors of utility. Methods: Hypertensive patients, from 40 to 80 years ol

  19. Decentralized forest governance in central Vietnam

    NARCIS (Netherlands)

    Tran Nam, T.; Burgers, P.P.M.

    2012-01-01

    A major challenge in decentralized forest governance in Vietnam is developing a mechanism that would support both reforestation and poverty reduction among people in rural communities. To help address this challenge, Forest Land Allocation (FLA) policies recognize local communities and individuals a

  20. Learning Vocabulary in Group Work in Vietnam

    Science.gov (United States)

    Huong, Le Pham Hoai

    2006-01-01

    This study investigated learning vocabulary in group work at university in Vietnam. The students were studied in two kinds of group settings, "unassisted" and "assisted", the first consisting of five students from the same class level and the second of four from the same class and a student from a higher class. Differences were…

  1. Governing pesticide in vegetable production in Vietnam

    NARCIS (Netherlands)

    Hoi, Van P.

    2010-01-01

    The economic liberalization in Vietnam, initiated in the middle of the 1980s, contributed to the further intensification and expansion of private actor-engagement in agriculture and food-supply. Vietnamese farmers, who already considered applying pesticides the most effective manner to protect their

  2. Social networks and wage outcomes in Vietnam

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Torm, Nina Elisabeth

    2011-01-01

    This paper analyzes the relationship between the use of informal contacts and wage outcomes using matched employer-employee data from small and medium firms in Vietnam. We find that obtaining a job through knowing another worker in the firm generally is positively associated with individual wages...

  3. Learning Vocabulary in Group Work in Vietnam

    Science.gov (United States)

    Huong, Le Pham Hoai

    2006-01-01

    This study investigated learning vocabulary in group work at university in Vietnam. The students were studied in two kinds of group settings, "unassisted" and "assisted", the first consisting of five students from the same class level and the second of four from the same class and a student from a higher class. Differences were observed in both…

  4. Treatment Failure for Malaria in Vietnam

    Centers for Disease Control (CDC) Podcasts

    2017-06-05

    WHO malaria expert, Dr. Charlotte Rasmussen, discusses anti-malarial drug resistance in Vietnam.  Created: 6/5/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/5/2017.

  5. Value Chain Development of Avocado in Vietnam

    NARCIS (Netherlands)

    Wertheim-Heck, S.C.O.; Quaedackers, P.; Nguyen Trung Anh,; Wijk, van S.

    2010-01-01

    Rapid economic development, urbanisation and rising income levels, in Vietnam offer potential for pro-poor development, by creating new market opportunities for producers, traders and retailers. This article describes the process of value chain development, which involves all actors in the broad cha

  6. Governing pesticide in vegetable production in Vietnam

    NARCIS (Netherlands)

    Hoi, Van P.

    2010-01-01

    The economic liberalization in Vietnam, initiated in the middle of the 1980s, contributed to the further intensification and expansion of private actor-engagement in agriculture and food-supply. Vietnamese farmers, who already considered applying pesticides the most effective manner to protect their

  7. Ichthyofauna of the reservoirs of Central Vietnam

    Directory of Open Access Journals (Sweden)

    I. A. Stolbunov

    2012-01-01

    Full Text Available Species composition, distribution and abundance of fish in the pelagic and littoral zone of four reservoirs of Central Vietnam (Suoi Chau, Kam Lam, Da Ban and Suoi Dau were studied first. According to the research data the fish community of the reservoirs is represented by 43 species of 19 fish families.

  8. Assessing the National Logistics System of Vietnam

    Directory of Open Access Journals (Sweden)

    Ruth Banomyong

    2015-03-01

    Full Text Available The purpose of this research is to present and analyse the current situation regarding the capability of the national logistics system in Vietnam. A national assessment framework for macro-logistics is utilised in combination with semi-structured interviews of key Vietnamese stakeholders to reflect on the current situation in the country. There are still numerous shortcomings in the Vietnamese logistics system. These shortcomings are not purely infrastructure based but also from a regulatory and commercial perspective. The presented national logistics system assessment framework can be replicated in other countries or regions when assessing national logistics capability. The findings can help foreign investors, international logistics providers wanting to provide their services in Vietnam to understand the logistics context within the country. These findings are also helpful for policy makers in Vietnam on how to improve their national logistics system. This study proposes a template to assess national logistics systems and provides an in-depth understanding of logistics in Vietnam, a country that has not been much studied in the literature.

  9. Land Titles and Rice Production in Vietnam

    DEFF Research Database (Denmark)

    Van Den Broeck, Katleen; Newman, Carol; Tarp, Finn

    In most of the empirical literature on land titling, the household is regarded as unitary, and land rights are found to have ambiguous effects on land allocation, investment and productivity. Using data from 12 provinces in Vietnam, we diversify land titles, and show in a household fixed effects...

  10. Deep Friendship Between Vietnam And China

    Institute of Scientific and Technical Information of China (English)

    Vu; Xuan; Hong

    2014-01-01

    <正>Vietnam and China are neighbors joined by rivers and mountains.Geographical location and history ensure close friendship.This is especially true since they both endured a long revolutionary struggle to achieve national liberation,forging what Chairman Ho Chi Minh once praised as"deep friendship between comrades and brothers".The history of the past 60 years

  11. MOTIVATION OF CHINESE INVESTMENT IN VIETNAM

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China attracted a record ofUS$52.7×109 in foreign direct investment (FDI) in the year 2002, surpassing the United States to become the world's largest FDI recipient. China's success in attracting FDI has received significant attention from academics. Several theoretical approaches have been developed to explain the determinants of FDI in China.However, it seems to be ignored that China has also become a growing provider of significant FDI to the rest of the world.According to United Nations Conference on Trade and Development (UNCTAD)'s 2004 report, as a developing country,replacing Japan, China has made the list of the expected top five home countries worldwide for the first time in terms of geographical coverage (2004-2005). Vietnam is second largest market and another emerging transition tiger in Southeast Asia. Both China and Vietnam were and are experiencing transitions from centrally planned economy to free market economy. This paper, therefore, attempts to explore the development of Chinese investment in Vietnam, analysing the main motives for, and characteristics of, Chinese Multinational Enterprises' (MNEs) investment in Vietnam.

  12. Land Titles and Rice Production in Vietnam

    DEFF Research Database (Denmark)

    Van Den Broeck, Katleen; Newman, Carol; Tarp, Finn

    In most of the empirical literature on land titling, the household is regarded as unitary, and land rights are found to have ambiguous effects on land allocation, investment and productivity. Using data from 12 provinces in Vietnam, we diversify land titles, and show in a household fixed effects...

  13. Political Connections and Investment in Rural Vietnam

    DEFF Research Database (Denmark)

    Markussen, Thomas; Tarp, Finn

    This paper uses household panel data from rural Vietnam to explore the effects of having a relative in a position of political or bureaucratic power on farmers’ agricultural investment decisions. Our main result is that households significantly increase their investment in land improvement...

  14. Abortion in Vietnam: measurements, puzzles, and concerns.

    Science.gov (United States)

    Goodkind, D

    1994-01-01

    This report summarizes current knowledge about abortion in Vietnam, drawing upon government statistics, survey data, and fieldwork undertaken by the author in Vietnam throughout 1993 and part of 1994. The official total abortion rate in Vietnam in 1992 was about 2.5 per woman, the highest in Asia and worrisome for a country with a still-high total fertility rate of 3.7 children per woman. Vietnamese provinces exhibited substantial variation in both the rate of abortion and the type of procedures performed. Among the hypotheses explored to explain Vietnam's high rate of abortion are the borrowing of family planning strategies from other poor socialist states where abortion is common; current antinatal population policies that interact with a lack of contraceptive alternatives; and a rise in pregnancies among young and unmarried women in the wake of recent free-market reforms. Because family-size preferences are still declining, abortion rates may continue to increase unless the incidence of unwanted pregnancy can be reduced, a goal that Vietnamese population specialists are seeking to achieve.

  15. Technology network for machine tools in Vietnam

    OpenAIRE

    Mizuno, Junko

    2012-01-01

    When Vietnam joined the WTO, it accepted foreign direct investment and started to grow. Technically, it was then greatly influenced by the enterprises that entered the country through direct investment. This report shows that the technology network for machine tools is formed via direct investment and subcontracting.

  16. Social networks and wage outcomes in Vietnam

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Torm, Nina Elisabeth

    2011-01-01

    This paper analyzes the relationship between the use of informal contacts and wage outcomes using matched employer-employee data from small and medium firms in Vietnam. We find that obtaining a job through knowing another worker in the firm generally is positively associated with individual wages...

  17. Recent morphological changes in the Mekong and Bassac river channels, Mekong delta: The marked impact of river-bed mining and implications for delta destabilisation

    Science.gov (United States)

    Brunier, Guillaume; Anthony, Edward J.; Goichot, Marc; Provansal, Mireille; Dussouillez, Philippe

    2014-11-01

    The Mekong delta, in Vietnam, is the world's third largest delta. Densely populated, the delta has been significantly armoured with engineering works and dykes to protect populations and infrastructure from storms, and shrimp farms from saltwater intrusion. Considerable development pressures in Vietnam and in the upstream countries have resulted in the construction of several dams in China and in important channel-bed aggregate extractions especially in Cambodia. The effects of these developments impact the delta dynamics in various ways. In this study, changes in the channel morphology of the Mekong proper and the Bassac, the two main distributaries in the 250 km-long deltaic reach from the Cambodian border to the coast, were analysed using channel depth data for 1998 and 2008. The channels display important and irregular bed changes over the 10-year comparison period, including significant incision and expansion and deepening of numerous pools. The mean depth of both channels increased by more than 1.3 m. Both channels also showed correlative significant bed material losses: respectively 90 million m3 in the Mekong and 110 million m3 in the Bassac over the 10-year period. These important losses over a relatively short period, and weak correlations between bed incision and hydraulic parameters suggest that the marked morphological changes are not in equilibrium with flow and sediment entrainment conditions, and are therefore not related to changes in river hydrology. We claim that aggregate extraction, currently practised on a very large scale in the Mekong delta channels and upstream of the delta, is the main cause of these recent morphological changes. These changes are deemed to contribute actively to rampant bank erosion in the delta as well as to erosion of the Mekong delta shoreline. Other contributory activities include the numerous dykes and embankments. The role of existing dams in bed losses remains unclear in the absence of reliable data on the Mekong

  18. Influence of illumination on the quantum mobility of a two-dimensional electron gas in Si delta-doped GaAs/In sub 0 sub . sub 1 sub 5 Ga sub 0 sub . sub 8 sub 5 As quantum wells

    CERN Document Server

    Cavalheiro, A; Quivy, A A; Takahashi, E K; Martini, S; Silva, M J D; Meneses, E A; Leite, J R

    2003-01-01

    A series of GaAs/InGaAs quantum wells with a silicon delta-doped layer in the top barrier was investigated by Shubnikov-de Haas measurements as a function of the illumination time of the samples. During the illumination process strong modifications of the electronic density and the quantum mobility of each occupied subband were observed. Based on self-consistent calculations, the dominant mechanism which caused the changes in the subband quantum mobilities with illumination was elucidated.

  19. The Niger Delta Crisis

    African Journals Online (AJOL)

    chifaou.amzat

    2013-09-28

    Sep 28, 2013 ... lions de barils par jour à environ 1 million au plus fort de la crise du Delta ... (JTF) between 13 May 2009 and 4 October 2009 (the deadline for embrac- ..... He had just ended his welcome address as the occasion's chairman.

  20. The magnetic and electronic properties of Methanobacterium thermoautotrophicum (strain delta H) methyl coenzyme M reductase and its nickel tetrapyrrole cofactor F430. A low temperature magnetic circular dichroism study.

    Science.gov (United States)

    Hamilton, C L; Scott, R A; Johnson, M K

    1989-07-15

    Variable temperature magnetic circular dichroism (MCD) spectroscopy has been used to characterize the magnetic and electronic properties of the Ni(II) tetrapyrrole, F430, which is the cofactor of the S-methyl coenzyme M methylreductase enzyme from Methanobacterium thermoautotrophicum (strain delta H). 4-Coordinate forms are found to be diamagnetic (S = 0 ground state), whereas 6-coordinate forms are paramagnetic (S = 1 ground state). MCD studies, together with parallel low temperature UV-visible absorption and resonance Raman investigations, show that the equilibrium distribution of 4-coordinate square-planar and 6-coordinate bis-aquo forms of the native isomer of F430 in aqueous solution is affected by both temperature and the presence of glycerol. In the presence of 50% glycerol, the 12,13-diepimer of F430 is shown to be partially 6-coordinate in frozen solution at low temperature. Low temperature MCD magnetization data allow the determination of the axial zero-field splitting (D) of the S = 1 ground state of bis-ligand complexes of F430. The value of D is sensitive to the nature of the Ni(II) axial ligands: bis-aquo F430, D = +9 +/- 1 cm-1; bis-imidazole F430, D = -8 +/- 2 cm-1. Measurement of D = +10 +/- 1 cm-1 for F430 in the methylreductase holoenzyme argues strongly against histidine imidazole coordination to Ni(II) in the enzyme. The possible existence of alcoholic or phenolic oxygen-containing ligands (serine, threonine, tyrosine, water) to Ni(II) in the enzyme-bound cofactor is discussed.

  1. Vietnam's Foreign Policy toward China since the 1970s

    OpenAIRE

    2007-01-01

    There is much debate about how Southeast Asia views China's ascendance on the world stage. Beijing's expanding economic, diplomatic, and military influence has countries in the region concerned about how China will use its new power and influence. Vietnam is particularly concerned, since it shares a border with China and for many centuries was under China's control. Vietnam's experience with China may shed some light on how Southeast Asia is adapting to China's rise. Today, Vietnam find...

  2. Contamination by perfluorinated compounds in water near waste recycling and disposal sites in Vietnam.

    Science.gov (United States)

    Kim, Joon-Woo; Tue, Nguyen Minh; Isobe, Tomohiko; Misaki, Kentaro; Takahashi, Shin; Viet, Pham Hung; Tanabe, Shinsuke

    2013-04-01

    There are very few reports on the contamination by perfluorinated chemicals (PFCs) in the environment of developing countries, especially regarding their emission from waste recycling and disposal sites. This is the first study on the occurrence of a wide range of PFCs (17 compounds) in ambient water in Vietnam, including samples collected from a municipal dumping site (MD), an e-waste recycling site (ER), a battery recycling site (BR) and a rural control site. The highest PFC concentration was found in a leachate sample from MD (360 ng/L). The PFC concentrations in ER and BR (mean, 57 and 16 ng/L, respectively) were also significantly higher than those detected in the rural control site (mean, 9.4 ng/L), suggesting that municipal solid waste and waste electrical and electronic equipment are potential contamination sources of PFCs in Vietnam. In general, the most abundant PFCs were perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUDA; waste materials.

  3. Determinants of foreign direct investment in Vietnam 1988-2009

    OpenAIRE

    Bui, Anh Tuan

    2011-01-01

    This thesis analyses the determinants of Foreign Direct Investment in Vietnam from 1988-2009. It examines the nature, motivation and impact of FDI upon the Vietnam economy and its contribution to the subsequent leap forward in economic growth. The focus is on developing Dunning’s eclectic theory through case study analysis of Honda-Vietnam Motorbike Company and ANZ-Vietnam Bank. The prominent theories on FDI generally used in the thesis focus on Vernon’s Product Life Cycle (PLC) model, the Ma...

  4. The lived experience of women military nurses in Vietnam during the Vietnam War.

    Science.gov (United States)

    Scannell-Desch, E A

    1996-01-01

    The lived experience of 24 military nurses during the Vietnam war is described in addition to common elements of their lives after returning from Vietnam. In-depth interviews generated data about personal and professional aspects of the lives of women nurses in the war zone. Data analysis incorporated the qualitative methods of Colaizzi, Lincoln and Guba, and Van Manen. Findings revealed that the nurses struggled with moral and ethical dilemmas of wartime nursing, felt out-of-place, and lacked privacy. The nurses described a deep and special bonding, and many found serving in Vietnam to be the most rewarding experience in their careers. The Vietnam War continues to have an effect on the lives of the nurses who served there. They balance their personal and professional growth gleaned from this experience with the physical and emotional stresses experienced during the war and since the war. The findings of this study have implications for further research about nurses in Vietnam and nurses who have served in other wars.

  5. Performance evaluation of photonic Sigma Delta ADCS

    OpenAIRE

    Tan, Yean Wee

    2010-01-01

    Approved for public release; distribution is unlimited The integration of photonic and electronic components to realize a photonic sigma delta ADC is considered in this thesis. The integration process was broken up into steps. First, the performance of a pair of dual-port Mach-Zehnder interferometers (MZI) modulating a train of narrow high-speed laser pulses from a mode-locked laser was investigated. Various parameters like the half-wave voltage (V) and insertion loss were verified. Nex...

  6. Nationwide investigation of the pyrethroid susceptibility of mosquito larvae collected from used tires in Vietnam.

    Science.gov (United States)

    Kawada, Hitoshi; Higa, Yukiko; Nguyen, Yen T; Tran, Son H; Nguyen, Hoa T; Takagi, Masahiro

    2009-01-01

    Pyrethroid resistance is envisioned to be a major problem for the vector control program since, at present, there are no suitable chemical substitutes for pyrethroids. Cross-resistance to knockdown agents, which are mainly used in mosquito coils and related products as spatial repellents, is the most serious concern. Since cross-resistance is a global phenomenon, we have started to monitor the distribution of mosquito resistance to pyrethroids. The first pilot study was carried out in Vietnam. We periodically drove along the national road from the north end to the Mekong Delta in Vietnam and collected mosquito larvae from used tires. Simplified susceptibility tests were performed using the fourth instar larvae of Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus. Compared with the other species, Ae. aegypti demonstrated the most prominent reduction in susceptibility. For Ae. aegypti, significant increases in the susceptibility indices with a decrease in the latitude of collection points were observed, indicating that the susceptibility of Ae. aegypti against d-allethrin was lower in the southern part, including mountainous areas, as compared to that in the northern part of Vietnam. There was a significant correlation between the susceptibility indices in Ae. aegypti and the sum of annual pyrethroid use for malaria control (1998-2002). This might explain that the use of pyrethroids as residual treatment inside houses and pyrethroid-impregnated bed nets for malaria control is attributable to low pyrethroid susceptibility in Ae. aegypti. Such insecticide treatment appeared to have been intensively administered in the interior and along the periphery of human habitation areas where, incidentally, the breeding and resting sites of Ae. aegypti are located. This might account for the strong selection pressure toward Ae. aegypti and not Ae. albopictus.

  7. Clinical microbiology during the Vietnam War.

    Science.gov (United States)

    Washington, Michael; Brown, Matthew; Palys, Thomas; Tyner, Stuart; Bowden, Robert

    2009-11-01

    During the period of 1965-1968, over two dozen Army microbiologists were deployed to various locations in Southeast Asia in support of the Vietnam War. Their role was to serve both a clinical laboratory mission/function at the mobile Army surgical hospital and mobile laboratory level as well as to perform research roles in all of the facilities. They were essential to the formulation of medical intelligence as well as to the practice of operational medicine in the deployed environment. The results of their laboratory investigations provided commanders and military physicians with critical medical information for patient care, outbreak investigation, and forensic analysis. As with many soldiers in support of the infantry and armor combat forces, most of the work occurs behind the scenes and their contributions are often left out of the historical literature. This article presents a brief overview of microbiology performed by Army microbiologists during the Vietnam War.

  8. Plasmodium knowlesi malaria in Vietnam: some clarifications

    Directory of Open Access Journals (Sweden)

    Hung Le

    2010-01-01

    Full Text Available Abstract A recently published comment on a report of Plasmodium knowlesi infections in Vietnam states that this may not accurately represent the situation in the study area because the PCR primers used may cross-hybridize with Plasmodium vivax. Nevertheless, P. knowlesi infections have been confirmed by sequencing. In addition, a neighbour-joining tree based on the 18S S-Type SSUrRNA gene shows that the Vietnamese samples clearly cluster with the P. knowlesi isolates identified in Malaysia and are distinct from the corresponding P. vivax sequences. All samples came from asymptomatic individuals who did not consult for fever during the months preceding or following the survey, indicating that asymptomatic P. knowlesi infections occur in this population, although this does not exclude the occurrence of symptomatic cases. Large-scale studies to determine the extent and the epidemiology of P. knowlesi malaria in Vietnam are further needed.

  9. Viral Advertising on Facebook in Vietnam

    OpenAIRE

    Tran, Phuong

    2014-01-01

    The purpose of this thesis is to explore which factors affect the effectiveness of viral advertising on Facebook in Vietnam. The quantitative research method is applied in this research and the sample is Vietnamese Facebook users. After the data analysis stage using SPSS, it became clear that weak ties, perceptual affinity and emotions have an impact on the effectiveness of viral advertising. The results provide a pratical implication of how to make an Ad which can go viral on Facebook. Moreo...

  10. Assessing the National Logistics System of Vietnam

    OpenAIRE

    Ruth Banomyong; Vinh V. Thai; Kum Fai Yuen

    2015-01-01

    The purpose of this research is to present and analyse the current situation regarding the capability of the national logistics system in Vietnam. A national assessment framework for macro-logistics is utilised in combination with semi-structured interviews of key Vietnamese stakeholders to reflect on the current situation in the country. There are still numerous shortcomings in the Vietnamese logistics system. These shortcomings are not purely infrastructure based but also from a regulatory ...

  11. Limited effectiveness of household sand filters for removal of arsenic from well water in North Vietnam.

    Science.gov (United States)

    Ilmiawati, Cimi; Thang, Nguyen Dinh; Iida, Machiko; Maeda, Masao; Ohnuma, Shoko; Yajima, Ichiro; Ohgami, Nobutaka; Oshino, Reina; Al Hossain, M M Aeorangajeb; Ninomiya, Hiromasa; Kato, Masashi

    2016-12-01

    Since well water utilized for domestic purposes in the Red River Delta of North Vietnam has been reported to be polluted by arsenic, barium, iron, and manganese, household sand filters consisting of various components are used. Information regarding the effectiveness of various sand filters for removal of the four toxic elements in well water is limited. In this study, arsenic levels in 13/20 of well water samples and 1/7 of tap water samples exceeded World Health Organization (WHO) health-based guideline value for drinking water. Moreover, 2/20, 6/20, and 4/20 of well water samples had levels exceeding the present and previous guideline levels for barium, iron, and manganese, respectively. Levels of iron and manganese, but not arsenic, in well water treated by sand filters were lower than those in untreated water, although previous studies showed that sand filters removed all of those elements from water. A low ratio of iron/arsenic in well water may not be sufficient for efficient removal of arsenic from household sand filters. The levels of barium in well water treated by sand filters, especially a filter composed of sand and charcoal, were significantly lower than those in untreated water. Thus, we demonstrated characteristics of sand filters in North Vietnam.

  12. A renewal of astronomy education in Vietnam

    Science.gov (United States)

    Wentzel, Donat G.

    Vietnam was scientifically completely isolated for almost 30 years. With French help, several lecture courses have introduced modern astrophysics to Vietnamese physicists, and four students are studying abroad. The IAU program "Teaching for Astronomy Development" (TAD) has concentrated on modernizing the on-going astronomy course for students in the third year of the pedagogical universities. Three one-to-two week "Teachers' Workshops" have served to introduce selected up-to-date astronomical topics and a few modern teaching methods. The TAD program has also provided appropriate journals, books, a PC and educational software. A new text, Astrophysics, in Vietnamese and English on facing pages and with color pictures - apparently a first for any textbook in Vietnam - will first be used starting in September 2000. Future aditional activities: collaboration to plan a new astronomy course in the twelfth grade of the natural science branch of the secondary schools; collaboration so that the 41-cm telescope and astronomers in Hanoi can produce some simple quality science; helping the only planetarium in Vietnam to acquire a wider range of offerings; helping to create a set of B.Sc.-level astrophysics courses for three universities; and supporting the Vietnamese Astronomical Society in effective public outreach.

  13. Simulation and optimisation modelling approach for operation of the Hoa Binh Reservoir, Vietnam

    DEFF Research Database (Denmark)

    Ngo, Long le; Madsen, Henrik; Rosbjerg, Dan

    2007-01-01

    Hoa Binh, the largest reservoir in Vietnam, plays an important role in flood control for the Red River delta and hydropower generation. Due to its multi-purpose character, conflicts and disputes in operating the reservoir have been ongoing since its construction, particularly in the flood season......, the hydro-meteorological conditions, and the time of the year. A heuristic global optimisation tool, the shuffled complex evolution (SCE) algorithm, is adopted for optimising the reservoir operation. The optimisation puts focus on the trade-off between flood control and hydropower generation for the Hoa....... This paper proposes to optimise the control strategies for the Hoa Binh reservoir operation by applying a combination of simulation and optimisation models. The control strategies are set up in the MIKE 11 simulation model to guide the releases of the reservoir system according to the current storage level...

  14. Use of physical/chemical mutagens in plant breeding program in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich [Agricultural Genetics Institute, Hanoi (Viet Nam)

    2001-03-01

    Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN{sub 3}). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

  15. Electronic structure of the gold/Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8 and gold/EuBa sub 2 Cu sub 3 O sub 7 minus. delta. interfaces as studied by photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dessau, D.S.; Shen, Z.; Wells, B.O.; Spicer, W.E. (Stanford Electronics Laboratories, Stanford University, Stanford, California 94305 (USA)); List, R.S.; Arko, A.J.; Bartlett, R.J.; Fisk, Z.; Cheong, S. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA)); Mitzi, D.B.; Kapitulnik, A. (Department of Applied Physics, Stanford University, Stanford, California 94305 (USA)); Schirber, J.E. (Sandia National Laboratories, Sandia, New Mexico 87185 (USA))

    1990-07-16

    High-resolution photoemission has been used to probe the electronic structure of the gold/Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} and gold/EuBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} interface formed by a low-temperature (20 K) gold evaporation on cleaved high quality single crystals. We find that the metallicity of the EuBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} substrate in the near surface region ({similar to}5 A) is essentially destroyed by the gold deposition, while the near surface region of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} remains metallic. This has potentially wide ranging consequences for the applicability of the different types of superconductors in real devices.

  16. Remote Sensing of River Delta Inundation: Exploiting the Potential of Coarse Spatial Resolution, Temporally-Dense MODIS Time Series

    Directory of Open Access Journals (Sweden)

    Claudia Kuenzer

    2015-07-01

    Full Text Available River deltas belong to the most densely settled places on earth. Although they only account for 5% of the global land surface, over 550 million people live in deltas. These preferred livelihood locations, which feature flat terrain, fertile alluvial soils, access to fluvial and marine resources, a rich wetland biodiversity and other advantages are, however, threatened by numerous internal and external processes. Socio-economic development, urbanization, climate change induced sea level rise, as well as flood pulse changes due to upstream water diversion all lead to changes in these highly dynamic systems. A thorough understanding of a river delta’s general setting and intra-annual as well as long-term dynamic is therefore crucial for an informed management of natural resources. Here, remote sensing can play a key role in analyzing and monitoring these vast areas at a global scale. The goal of this study is to demonstrate the potential of intra-annual time series analyses at dense temporal, but coarse spatial resolution for inundation characterization in five river deltas located in four different countries. Based on 250 m MODIS reflectance data we analyze inundation dynamics in four densely populated Asian river deltas—namely the Yellow River Delta (China, the Mekong Delta (Vietnam, the Irrawaddy Delta (Myanmar, and the Ganges-Brahmaputra (Bangladesh, India—as well as one very contrasting delta: the nearly uninhabited polar Mackenzie Delta Region in northwestern Canada for the complete time span of one year (2013. A complex processing chain of water surface derivation on a daily basis allows the generation of intra-annual time series, which indicate inundation duration in each of the deltas. Our analyses depict distinct inundation patterns within each of the deltas, which can be attributed to processes such as overland flooding, irrigation agriculture, aquaculture, or snowmelt and thermokarst processes. Clear differences between mid

  17. Hot deformation behavior of delta-processed superalloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-03-25

    Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

  18. Delta Electroproduction in 12-C

    Energy Technology Data Exchange (ETDEWEB)

    McLauchlan, Steven [Univ. of Glasgow, Scotland (United Kingdom)

    2003-01-01

    The Δ-nucleus potential is a crucial element in the understanding of the nuclear system. Previous electroexcitation measurements in the delta region reported a Q2 dependence of the Δ mass indicating that this potential is dependent on the momentum of the Δ. Such a dependence is not observed for protons and neutrons in the nuclear medium. This thesis presents the experimental study of the electroexcitation of the Δ resonance in 12C, performed using the high energy electron beam at the Thomas Jefferson National Accelerator Facility, and the near 4π acceptance detector CLAS that enables the detection of the full reaction final state. Inclusive, semi inclusive, and exclusive cross sections were measured with an incident electron beam energy of 1.162GeV over the Q2 range 0.175-0.475 (GeV/c)2. A Q2 dependence of the Δ mass was only observed in the exclusive measurements indicating that the Δ-nucleus potential is affected by the momentum of the Δ.

  19. 77 FR 51514 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary Affirmative...

    Science.gov (United States)

    2012-08-24

    ... International Trade Administration Steel Wire Garment Hangers From the Socialist Republic of Vietnam... of steel wire garment hangers from the Socialist Republic of Vietnam (``Vietnam'').\\1\\ On August 2... Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary Determination of Sales...

  20. 77 FR 46044 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary Determination of...

    Science.gov (United States)

    2012-08-02

    ... Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary Determination of Sales at Less... preliminarily determine that steel wire garment hangers from the Socialist Republic of Vietnam (``Vietnam'') are... (``AD'') petition concerning imports of steel wire garment hangers from Vietnam filed in proper form...

  1. 77 FR 32930 - Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Preliminary...

    Science.gov (United States)

    2012-06-04

    ... International Trade Administration Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam... garment hangers (garment hangers) from the Socialist Republic of Vietnam (Vietnam). For information on the... received a countervailing duty (CVD) petition concerning imports of garment hangers from Vietnam filed...

  2. 75 FR 55740 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Preliminary...

    Science.gov (United States)

    2010-09-14

    ... International Trade Administration Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam... frozen warmwater shrimp from the Socialist Republic of Vietnam (``Vietnam''). The review covers the... of the antidumping duty orders on certain frozen warmwater shrimp from Vietnam and the...

  3. 38 CFR 3.313 - Claims based on service in Vietnam.

    Science.gov (United States)

    2010-07-01

    ... in Vietnam. 3.313 Section 3.313 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... Evaluations; Service Connection § 3.313 Claims based on service in Vietnam. (a) Service in Vietnam. Service in Vietnam includes service in the waters offshore, or service in other locations if the conditions...

  4. Timelike gamma* N -> Delta form factors and Delta Dalitz decay

    CERN Document Server

    Ramalho, G

    2012-01-01

    We extend a covariant model, tested before in the spacelike region for the physical and lattice QCD regimes, to a calculation of the gamma* N -> Delta reaction in the timelike region, where the square of the transfered momentum, q^2, is positive (q^2>0). We estimate the Dalitz decay Delta -> Ne+e- and the Delta distribution mass distribution function. The results presented here can be used to simulate the NN -> NNe+e- reactions at moderate beam kinetic energies.

  5. Health economics of screening for hypertension in Vietnam

    NARCIS (Netherlands)

    Nguyen, Thi Phuong Lan

    2016-01-01

    The studies aims to identify the burden of a cardiovascular diseases and solutions to manage it in Vietnam, notably hypertension screening. The studies confirmed that hypertension creates a great burden in Vietnam in terms of cardiovascular diseases, from economic, clinical and social perspectives.

  6. Education and Economic, Political, and Social Change in Vietnam

    Science.gov (United States)

    Huong, Pham Lan; Fry, Gerald W.

    2004-01-01

    This paper provides an overview of the complex relations among history, education, political economy, and social change in Vietnam. Vietnam has a long history of education and a literate culture. The evolution of Vietnamese culture and society is characterized by both persistence and change. Social and political persistence and change have been…

  7. Strategies for Long Term Economic Growth in Vietnam

    Science.gov (United States)

    2013-11-01

    Report Vietnam," EBSCO Host, April 4, 2013, Accessed September 6, 2013, http://search.ebscohost.com/login.aspx?direct=true&db=bth&AN=86710391&-site...IHS Global Insight. "Country Report Vietnam." EBSCO Host. April 4, 2013. Accessed September 6, 2013. http://search.ebscohost.com/login.aspx?direct

  8. Transgender at Work: Livelihoods for Transgender People in Vietnam

    NARCIS (Netherlands)

    Hoang, T.A.; Oosterhoff, P.

    2016-01-01

    The laws in the Socialist Republic of Vietnam promote equality for all citizens and refer to ‘persons’ rather than ‘men’ or ‘women’. However, because of traditional gender norms, transgender people in Vietnam are facing severe stigma and discrimination in public, in schools, at home and in the workp

  9. Refighting the Last War: Afghanistan and the Vietnam Template

    Science.gov (United States)

    2009-12-01

    exact political and military reenactment of the Vietnam War, and the lack of self-awareness of the repetition of events 50 years ago is deeply...as in the Bill Murray film ) epitomized by the paradigmatic tragedy of Hamburger Hill in Vietnam. Instead of “clear, hold and build,” what the U.S

  10. Changing forestry discourses in Vietnam in the past 20 years

    NARCIS (Netherlands)

    Dang, T.K.P.; Turnhout, E.; Arts, B.J.M.

    2012-01-01

    Governance and sustainability are important topics of debate in global forest policy. It is however crucial to understand how these ideas have impacted national and local forest policy and management. The case of Vietnam is interesting and relevant because since the late 1980s, Vietnam's state fores

  11. Vietnam: Education Financing. A World Bank Country Study.

    Science.gov (United States)

    World Bank, Washington, DC.

    This study examines the system of education and training in Vietnam and poses the question: what changes in educational policies will ensure that students who pass through the system today will acquire the knowledge, skills, and attitudes needed for Vietnam to successfully complete the transition from a planned to a market economy? The report…

  12. Teaching the New Vietnam: It's a Country, Not a War

    Science.gov (United States)

    McCornac, Dennis C.

    2008-01-01

    Vietnam has made remarkable progress over the past two decades in its transition to a market economy resulting in numerous changes to both its social and economic institutions. It is a nation at peace focusing on economic development and integrating into the world economy. Although the tragic events in Vietnam's history cannot be forgotten, the…

  13. Transforming Vietnam's Medical Education through E-Learning

    Science.gov (United States)

    Churton, Michael W.

    2011-01-01

    The costs for providing medical school education and services in Vietnam's universities continue to increase. Through a collaborative project between the Government of the Netherlands and Vietnam's Ministry of Health, a five year experimental program to develop in-country capacity and reduce the dependence upon a foreign medical service delivery…

  14. The History and Future of Community Colleges in Vietnam

    Science.gov (United States)

    Le, Anh T.

    2013-01-01

    Since 1986, with the creation of the Renovation ("Doi moi") policy, Vietnam has demonstrated a strong commitment to the improvement of its higher education system. After 25 years of opening its doors to the global educational environment, Vietnam has achieved some notable accomplishments. The country's higher educational system has…

  15. Transgender at Work: Livelihoods for Transgender People in Vietnam

    NARCIS (Netherlands)

    Hoang, T.A.; Oosterhoff, P.

    2016-01-01

    The laws in the Socialist Republic of Vietnam promote equality for all citizens and refer to ‘persons’ rather than ‘men’ or ‘women’. However, because of traditional gender norms, transgender people in Vietnam are facing severe stigma and discrimination in public, in schools, at home and in the workp

  16. Emergence of Integrated Water Resources Management: measuring implementation in Vietnam

    NARCIS (Netherlands)

    Akkerman, M.; Khanh, N.T.; Witter, M.; Rutten, M.M.

    2015-01-01

    Recently, the changes in laws and regulations, such as the revised Law on Water Resources in 2012, have sought to provide a legal framework for the internationally recognized practices of Integrated Water Resources Management (IWRM) in Vietnam. With IWRM being a novel approach for Vietnam, it would

  17. Analysis on Rice Production and International Trade in Vietnam

    Institute of Scientific and Technical Information of China (English)

    RUAN Liu-qing; JIANG Yun-zhu; LU Li-xiang; LIN Hai; PANG Qian-lin

    2011-01-01

    This paper introduces Vietnam’s climate condition,main rice production regions and analyses the expansion of rice planting area,rice cropping system during the last decades.The result from the change of rice production,planting area,yield,and rice trade indicates that the economic reforms in Vietnam from 1986 have contributed to a spectacular rise in rice production and exports.However,there are still problems and opportunities for rice production and export in Vietnam.The paper suggests that Vietnam should make the most use of the advanced international rice cultivars and technology to improve irrigation and water conservancy facilities to benefit rice farmer and consolidate Vietnam to be the major exporter of rice in the world market.%This paper introduces Vietnam's climate condition,main rice production regions and analyses the expansion of rice planting area,rice cropping system during the last decades.The result from the change of rice production,planting area,yield,and rice trade indicates that the economic reforms in Vietnam from 1986 have contributed to a spectacular rise in rice production and exports.However,there are still problems and opportunities for rice production and export in Vietnam.The paper suggests that Vietnam should make the most use of the advanced international rice cultivars and technology to improve irrigation and water conservancy facilities to benefit rice farmer and consolidate Vietnam to be the major exporter of rice in the world market.

  18. Trade patterns facilitating highly pathogenic avian influenza virus dissemination in the free-grazing layer duck system in Vietnam.

    Science.gov (United States)

    Meyer, A; Dinh, T X; Han, T A; Do, D V; Nhu, T V; Pham, L T; Nguyen, T T T; Newman, S; Häsler, B; Pfeiffer, D U; Vergne, T

    2017-08-16

    Highly pathogenic avian influenza (HPAI) viruses continue to threaten smallholder poultry producers in several South-east Asian countries, including Vietnam. In particular, the free-grazing duck system has been repeatedly highlighted as a major risk factor for HPAI outbreaks. Free-grazing ducks, which scavenge on rice paddies after the harvest, account for a large proportion of the duck population in Vietnam and the wider South-east Asian region. However, the structure and dynamics of the free-grazing duck production from farm to consumption has not been described for Vietnam. In this study, we used a value chain approach to provide a complete picture of the actors involved in the production and marketing of free-grazing duck eggs and spent layer ducks, as well as to investigate the governance structure of this food system. Group interviews and key informant interviews were conducted in two provinces located in the Mekong River Delta (MRD) and the Red River Delta (RRD). The results presented here highlight similarities and differences in farming and trade practices between the two provinces. The trade of spent layer ducks involved large volumes of live ducks being sent to China and Cambodia for consumption, generating a substantial risk of transboundary spread of pathogens, including HPAI viruses. We describe the major role of "duck yards", which act as hubs in the northbound trade of spent layer ducks. These yards should be considered as essential links in the value chain of spent layer ducks when considering HPAI surveillance and control. The veterinary authorities are only marginally involved in the value chain activities, and their influence could be strengthened by increasing surveillance activities for instance in duck yards. Last, we discuss the dynamics of the duck value chain and further implications for future HPAI management policies. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

  19. SLIPTA e-Tool improves laboratory audit process in Vietnam and Cambodia

    Directory of Open Access Journals (Sweden)

    Thuong T. Nguyen

    2014-09-01

    Full Text Available Background: The Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA checklist is used worldwide to drive quality improvement in laboratories in developing countries and to assess the effectiveness of interventions such as the Strengthening Laboratory Management Toward Accreditation (SLMTA programme. However, the paperbased format of the checklist makes administration cumbersome and limits timely analysis and communication of results.Development of e-Tool: In early 2012, the SLMTA team in Vietnam developed an electronic SLIPTA checklist tool. The e-Tool was pilot tested in Vietnam in mid-2012 and revised. It was used during SLMTA implementation in Vietnam and Cambodia in 2012 and 2013 and further revised based on auditors’ feedback about usability.Outcomes: The SLIPTA e-Tool enabled rapid turn-around of audit results, reduced workload and language barriers and facilitated analysis of national results. Benefits of the e-Tool will be magnified with in-country scale-up of laboratory quality improvement efforts and potential expansion to other countries.

  20. Wicked problems: a value chain approach from Vietnam's dairy product.

    Science.gov (United States)

    Khoi, Nguyen Viet

    2013-12-01

    In the past few years, dairy industry has become one of the fastest growing sectors in the packaged food industry of Vietnam. However, the value-added creation among different activities in the value chain of Vietnam dairy sector is distributed unequally. In the production activities, the dairy farmers gain low value-added rate due to high input cost. Whereas the processing activities, which managed by big companies, generates high profitability and Vietnamese consumers seem to have few choices due to the lack of dairy companies in the market. These wicked problems caused an unsustainable development to the dairy value chain of Vietnam. This paper, therefore, will map and analyze the value chain of the dairy industry in Vietnam. It will also assess the value created in each activity in order to imply solutions for a sustainable development of Vietnam's dairy industry. M10, M11.

  1. Collaborative Disaster Preparedness: Vietnam, the United States, and Regional Experiences (Proceedings from Da Nang, Vietnam, August 1820, 2015)

    Science.gov (United States)

    2016-05-19

    reiterated what other presenters highlighted—rather than provide materials or goods, if the market is open , the humanitarian organizations are encouraged...Department of Defense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 USAID/OFDA Operations in Vietnam...from Da Nang, Vietnam, August 18–20, 2015) Operation Damayan

  2. Delta II commercial space transportation

    Science.gov (United States)

    Meyers, J. F.

    1988-07-01

    Delta II is an upgraded variant of the Delta family of launch vehicles that has been in use by NASA since 1960. Among the design improvements incorporated by Delta II is a cryogenic-propellant second stage, a 2.89-m diameter satellite-protecting nose fairing, graphite/epoxy solid rocket motor cases, and 12:1 main engine expansion nozzle. The manufacturer/operator offers Delta II customers a dedicated, single satellite launch capability fully tailored to the given spacecraft's unique mission requirements.

  3. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

  4. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia wh

  5. Peat compaction in deltas : implications for Holocene delta evolution

    NARCIS (Netherlands)

    van Asselen, S.|info:eu-repo/dai/nl/304838101

    2010-01-01

    Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

  6. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia wh

  7. Soil potassium dynamics under intensive rice cropping. A case study in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, M.H.

    2003-01-01

    Keywords:potassium, nutrient budgets, nutrient depletion, fertilizer, kinetics, adsorption,desorption, fixation, release, modeling, rice cropping system,NaTPB-extra

  8. Sustainable Development of Integrated Rice-fish Polyculture Systems in the Mekong Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Duong Nhut Long

    2003-01-01

    Full Text Available Huit variétés de niébé améliorées et une locale (témoin ont été testées en champ pendant trois ans en vue d'évaluer leur performance à produire à la fois des graines et du fourrage. Les résultats obtenus montrent que les taux de germination et de croissance étaient élevés (80% pour toutes les variétés étudiées. Les moyennes de rendement étaient respectivement de 1262 à 3598 kg/ha pour la production de fourrage sec et de 528 à 1149 kg/ha pour la production de graines. Les variétés IAR 4/48/15-1, IAR 72 et TVU 12349 ont produit la plus grande quantité de feuilles vertes (&amp;amp;amp;amp;gt; 50% au stade de la récolte de graines durant la saison sèche tandis que les variétés IAR 4/48/15-1, IAR 7/180-4-5 et TVU 12349 ont produit le plus grand nombre de gousses par plant. Le poids de 100 graines le plus élevé a été produit par la variété IT89KD-288 et la variété témoin (Kananado. Le pourcentage moyen de la matière protéique variait de 15,2 à 21,6%.Une faible corrélation a été observée entre les rendements en graines, les rendements en fourrage et le rapport gousses/plant. Pour l'augmentation du revenu des fermiers, les variétés TVU 12349, IT89KD-288, IAR 7/180-4-12 et IAR 4/48/15-1 s'avèrent les plus performantes pour ces paramètres étudiés et sont à recommander dans un système de production intégré.

  9. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    and 2842 g fresh aboveground biomass of Ipomoea aquatica Forssk., Lactuca sativa L. and C. glauca, respectively, were produced. The leafy vegetables provide some extra income besides fish products, whereas C. glauca provides nice flowers and contributes to a significant nutrient removal with annual uptake...

  10. Improving sustainability of striped catfish (Pangasianodon hypophthalmus) farming in the Mekong Delta, Vietnam through recirculation technology

    NARCIS (Netherlands)

    Nguyen, Nhut

    2016-01-01

    The aim of this thesis was to document improvements in sustainability indicators of striped catfish (Pangasianodon hypophthalmus, Sauvage, 1878) production through the application of recirculation and waste treatment techniques. To be able to document improvements in sustainability, in each system s

  11. Vegetable production after flooded rice improves soil properties in the Red River Delta, Vietnam

    NARCIS (Netherlands)

    Everaarts, A.P.; Neeteson, J.J.; Pham Thi Thu, H.; Struik, P.C.

    2015-01-01

    Vegetable production in South East Asia often is in rotation with °ooded rice. The puddling of the soil with flooded rice production may result in unfavourable soil conditions for the subsequent production of dry land crops. To establish whether permanent vegetable production results in favourable s

  12. Biological observations on the mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, Rikke Hagstrøm; Meilvang, A. S.; Cedhagen, T.

    2009-01-01

    ), gonad histology, fecundity and some observations on post-larvae and juveniles. In the population studied the sex ratio was skewed toward males. Females had a shorter mean length and a lower mean growth rate than males. No mature males or females were observed among mudskippers sampled in estuarine...

  13. Soil potassium dynamics under intensive rice cropping. A case study in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, M.H.

    2003-01-01

    Keywords:potassium, nutrient budgets, nutrient depletion, fertilizer, kinetics, adsorption,desorption, fixation, release, modeling, rice cropping system,

  14. Clonal occurrence of Salmonella Weltevreden in cultured shrimp in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Uddin, Gazi Md Noor; Larsen, Marianne Halberg; Barco, Lisa;

    2015-01-01

    . Weltevreden was susceptible to most antimicrobials tested, with a few strains being resistant to florfenicol, chloramphenicol, sulfamethoxazole or trimethoprim. Future studies of the ecology of S. Weltevreden should establish if this serovar may survive better and even multiply in warm-water shrimp farm...

  15. Economic and nutrient discharge tradeoffs of excreta-fed aquaculture in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nhan, D.K.; Verdegem, M.C.J.; Binh, N.T.; Duong, L.T.; Milstein, A.; Verreth, J.A.J.

    2008-01-01

    The present study quantifies the effects on production, nutrient discharge and economic return of the use of pig and human excreta in pond tanning. On-farm data from various studies were integrated and analyzed applying single and multiple regression methods. Pond-dissolved oxygen concentration, wat

  16. [Tapeworm fauna of gallinaceans (Galliformes) of Vietnam].

    Science.gov (United States)

    Nguen Thi, K y; Dubinina, M N

    1978-01-01

    131 specimens of 3 species of Galliformes from Vietnam were investigated (Gallus gallus dom., G. g. jaboruillei, Francolinus pintadeanus and Lophora nycthemerus). In them 9 species of cestodes were found as follows: Davainea proglottina (Davainea, 1860), Cotugnia digonopora (Pasquale, 1890), Raillietina tetragona (Molin, 1858), R. echinobothrida (Megnin, 1880), Skrjabinia cesticillus (Molin, 1858), Paroniella tinguiana Tubangui et Masilungan, 1937, Amoebotaenia cuneata (Linstow, 1872), Echinolepis carioca (Magalhaes, 1898), Dilepidoides bauchei (Joyeux, 1924). In domestic hens there were found all 9 species of cestodes while in wild Galliformes--only 7, which are mentioned for them for the first time.

  17. The 2003 Merged Model for Vietnam

    OpenAIRE

    Jensen, Henning Tarp; Tarp, Finn

    2006-01-01

    This paper documents the 2003 Merged Model for Vietnam. The initialization and calibration of the model is based on a financial 2003 SAM framework and an auxiliary 2002-3 data set. The recursive nature of the solution of the Merged Model is discussed with reference to the four main sectors of the model, including (i) the goods market and private sector budget, (ii) the government budget, (iii) the money market, and (iv) the balance of payments, and the initialization and solution of individua...

  18. Firm-Level Corruption in Vietnam

    DEFF Research Database (Denmark)

    Rand, John; Tarp, Finn

    2012-01-01

    and government contracts. Third, the observed decrease in bribe incidence between 2005 and 2007 is largely driven by significant behavioral changes. These behavioral changes seem to be associated with policy initiatives to improve law enforcement and increased media focus on punitive actions against corruption.......This article uses panel data from a survey of small- and medium-sized enterprises in Vietnam to uncover which firms pay bribes and which do not. We also study how bribe paying evolved between 2005 and 2007 and test how the determinants of bribes changed between the two years. Three sets of insights...

  19. $\\Delta$-N Electromagnetic Transition

    CERN Document Server

    Loan, M

    1999-01-01

    The EM ratio for a free Delta electromagnetic transition is discussed within the frame work of nonrelativistic approach. Such an approach gives a good account of data for a free Delta but is less important for an intrinsically relativistic nuclear many body problem.

  20. Mida pakub Delta? / Teele Kurm

    Index Scriptorium Estoniae

    Kurm, Teele

    2011-01-01

    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  1. Mida pakub Delta? / Teele Kurm

    Index Scriptorium Estoniae

    Kurm, Teele

    2011-01-01

    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  2. Mackenzie River Delta, Canada

    Science.gov (United States)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789. The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  3. DELTA 3D PRINTER

    Directory of Open Access Journals (Sweden)

    ȘOVĂILĂ Florin

    2016-07-01

    Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.

  4. Proposed Training Plan to Improve Building Energy Efficiency in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Sha; Evans, Meredydd

    2013-01-01

    Vietnam has experienced fast growth in energy consumption in the past decade, with annual growth rate of over 12 percent. This is accompanied by the fast increase in commercial energy use, driven by rapid industrialization, expansion of motorized transport, and increasing energy use in residential and commercial buildings. Meanwhile, Vietnam is experiencing rapid urbanization at a rate of 3.4 percent per year; and the majority of the growth centered in and near major cities such as Hanoi and Ho Chi Minh City. This has resulted in a construction boom in Vietnam.

  5. Exporting a Scandinavian Learning Model to Egypt and Vietnam

    DEFF Research Database (Denmark)

    Youssef, Sandra Safwat; Bygholm, Ann; Jæger, Kirsten

    2013-01-01

    many challenges. In this paper, we will present findings from an ethnographic study of the learning systems in higher education in Denmark, Egypt and Vietnam. The sample includes undergraduate level classes taught in Denmark, Egypt and Vietnam. The selected learning setting include an 'Academic...... Communication and Grammar' class in Denmark, a 'Financial Management' class in Vietnam and a 'Marketing Management' class in Egypt. To analyze the data collected, the researcher developed a model based on a constructivist understanding of learning processes. Three detailed descriptions of observations made......, and the LS observed in Egypt is predominantly student-materials centered...

  6. Formal and Informal Rural Credit in Four Provinces of Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel Christoffer; Tarp, Finn

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders. Formal loans are almost entirely for production and asset accumulation, while informal loans are used for co...... are striking. A ‘one size fits all' approach to credit policy in Vietnam would be inappropriate......This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders. Formal loans are almost entirely for production and asset accumulation, while informal loans are used...

  7. Delta self-consistent field method to obtain potential energy surfaces of excited molecules on surfaces

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Olsen, Thomas; Engelund, Mads;

    2008-01-01

    We present a modification of the Delta self-consistent field (Delta SCF) method of calculating energies of excited states in order to make it applicable to resonance calculations of molecules adsorbed on metal surfaces, where the molecular orbitals are highly hybridized. The Delta SCF approximation...... is a density-functional method closely resembling standard density-functional theory (DFT), the only difference being that in Delta SCF one or more electrons are placed in higher lying Kohn-Sham orbitals instead of placing all electrons in the lowest possible orbitals as one does when calculating the ground......-state energy within standard DFT. We extend the Delta SCF method by allowing excited electrons to occupy orbitals which are linear combinations of Kohn-Sham orbitals. With this extra freedom it is possible to place charge locally on adsorbed molecules in the calculations, such that resonance energies can...

  8. Essays on Impact evaluation: new empirical evidence from Vietnam

    NARCIS (Netherlands)

    Nguyen Viet Cuong, N.

    2009-01-01

    Keywords: Credit, cash transfers, remittances, migration, poverty, inequality, impact evaluation, Vietnam, Asia This study estimates the impact of various economic flows including government-subsidized micro-credit, informal credit, public and private transfers, international remittances, and migr

  9. Understanding Presidential Rhetoric: The Vietnam Statements of Lyndon Johnson

    Science.gov (United States)

    Sigelman, Lee; Miller, Lawrence

    1978-01-01

    Focuses on Lyndon Johnson's public statements about Vietnam during the final eighteen months of his presidency in an attempt to gain a perspective on the factors which shape presidential rhetoric. (MH)

  10. Dendrobium roseiodorum (Orchidaceae): a new species from Vietnam

    NARCIS (Netherlands)

    Sathapattayanon, A.; Yukawa, T.; Seelanan, T.

    2010-01-01

    In the course of revisionary work of Dendrobium section Formosae, we found some misinterpretations of Dendrobium kontumense. Dendrobium schildhaueri is placed as a synonym of D. kontumense and D. roseiodorum, a new species from Vietnam, is described.

  11. Vestalaria vinnula spec. nov. from southern Vietnam (Odonata: Calopterygidae)

    NARCIS (Netherlands)

    Hämäläinen, M.

    2006-01-01

    Vestalaria vinnula spec.nov. (holotype male, southern Vietnam, Lam Dong province, Blao, 1962) is described in both sexes and compared with other species of Vestalaria May, 1935 (= the Vestalis smaragdina - group), which is ranked as valid genus.

  12. Delegation of Chinese Advisers And Veterans Visits Vietnam

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>At the invitation of the Vietnam Union of Friendship Organizations (VUFO),Jing Dunquan, vice president of the CPAFFC, led the delegation of Chinese advisers and veterans who had participated in China’s aid mission to help

  13. Vestalaria vinnula spec. nov. from southern Vietnam (Odonata: Calopterygidae)

    NARCIS (Netherlands)

    Hämäläinen, M.

    2006-01-01

    Vestalaria vinnula spec.nov. (holotype male, southern Vietnam, Lam Dong province, Blao, 1962) is described in both sexes and compared with other species of Vestalaria May, 1935 (= the Vestalis smaragdina - group), which is ranked as valid genus.

  14. Current status of soil-transmitted helminths in Vietnam

    DEFF Research Database (Denmark)

    van der Hoek, Wim; De, Nguyen Van; Konradsen, Flemming

    2003-01-01

    This paper provides a review of surveys on soil-transmitted helminths that were done in Vietnam between 1990 and 2001. Prevalence estimates could be obtained for 29 of the 61 provinces. Extrapolating from this, it is estimated that 33.9 million people in Vietnam are infected with Ascaris (prevale......This paper provides a review of surveys on soil-transmitted helminths that were done in Vietnam between 1990 and 2001. Prevalence estimates could be obtained for 29 of the 61 provinces. Extrapolating from this, it is estimated that 33.9 million people in Vietnam are infected with Ascaris...... is more evenly distributed throughout the country, but is concentrated in peri-urban and rural agricultural areas. Vegetable cultivation in which nightsoil is used as fertilizer is a risk factor for hookworm infection, especially among adult women. Helminth control programs should be targeted at school...

  15. WORLD DELTAS AND THEIR EVOLUTION

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In August 1998, an international symposium on the world deltas was held in New Orleans, Louisiana, USA. This symposium attracted discussion about more than 25 deltas from around the world with emphasis placed on those that are most densely populated and impacted by humans. Keynote papers printed details about the physical, biological, engineering and socioeconomic aspects of six deltas including the Mississippi, Nile, Ganges-Brahmaputra, Rhine-Meuse, Changjiang and Po. The main purpose of this symposium was to inform scientists, engineers and decision-makers about information that is currently available and to provide them a basis for working in such environments.

  16. Dynamical Casimir effect with $\\delta-\\delta^{\\prime}$ mirrors

    CERN Document Server

    Silva, Jeferson Danilo L; Alves, Danilo T

    2016-01-01

    We calculate the spectrum and the total rate of created particles for a real massless scalar field in $1+1$ dimensions, in the presence of a partially transparent moving mirror simulated by a Dirac $\\delta-\\delta^{\\prime}$ point interaction. We show that, strikingly, a partially reflecting mirror can produce a larger number of particles in comparison with a perfectly reflecting one. In the limit of a perfect mirror, our formulas recover those found in the literature for the Robin boundary condition.

  17. Towards improving perinatal maternal mental health in Vietnam

    OpenAIRE

    Niemi, Maria

    2012-01-01

    Major depression is increasing world-wide, and is the third leading cause of the global disease burden. In Vietnam, perinatal depression is underdiagnosed and under-treated, leading to severe consequences for the pregnant mother, her child and surroundings. AIMS: The overall aim was to improve knowledge about perinatal depression to contribute to evidence based development of prevention and treatment strategies in Vietnam. The specific aims were: To generate a report of the mental health prio...

  18. Air Freight Service Development Plan : Case: CMA CGM Logistics Vietnam

    OpenAIRE

    Nguyen, Giang

    2014-01-01

    Being one of the fastest-growing nations in the world, Vietnam is trading across the border actively and at the same time attracting multiple foreign investments. Import and export activities are occurring vigorously which leads to a huge potential for international transportation sectors, particularly for aviation industry. Hence, the ultimate goal of this thesis is to establish a development plan of air freight service for the case company – CMA CGM Logistics Vietnam (CCLOG VN). The stu...

  19. Rewriting the Vietnam Narrative: Strategic Partnership Opportunities in Southeast Asia

    Science.gov (United States)

    2013-03-01

    subjected the people of Vietnam to their colonial policies remaining in tight control with the exception of World War II when Japan seized Vietnam and...awards/benefit2005/vietnamese_essay.shtml (accessed December 22, 2012). 4 Nguyen Hong Thao and Ramses Amer, “Managing Vietnam’s Maritime Boundary...Disputes,” Ocean Development & International Law 38, no. 3 (August 2007): 306 5 Ibid., 306. 6 Ramses Amer, “The Territorial Disputes between China and

  20. Students' expectation toward service of recruiment agencies in Vietnam

    OpenAIRE

    Tran, Hanh

    2010-01-01

    The objective of the thesis was to explore the expectations of students studying abroad to recruitment agencies in Vietnam. The study aims at recommend the right service for recruit-ment agencies offer to students to find a job and explore the culture obstacles for their career development when return home. The study originated from author’s own experience when finding an internship in Vietnam. The theoretical framework is based on relevant areas of theories of recruitment process, na-...

  1. State-Owned Enterprises and Economic Reform in Vietnam

    Science.gov (United States)

    2013-11-01

    FDI ), and prevents the effective development of required infrastructure. Vietnam cannot enjoy sustained economic growth while grand corruption... FDI ) has also suffered. Research shows that systemic corruption has a significant negative impact on FDI and the impact is cumulative with higher...levels of corruption resulting in a greater loss of FDI . 9 This is particularly unfortunate for Vietnam whose economy is riddled with corruption but

  2. Vietnam’s Drive to Modernize Militarily - Causes and Implications

    Science.gov (United States)

    2014-12-01

    The SCS is of utmost importance to Vietnam because of its role in economic activities, which include fishing, tourism , and oil and gas exploitation...shifted [Vietnam’s] foreign policy from one of confrontation to one of accommodation with former foes.”366 Essentially, Vietnam’s defense ministry...pursued a similar accommodating and omnidirectional strategy with the international community. Hiep notes, “Facing a far more powerful China, Vietnam

  3. Transverse response functions in the $\\Delta$-resonance region

    CERN Document Server

    Rost, E; Shepard, J R

    1992-01-01

    We calculate transverse response functions for quasi-elastic electron scattering at high momentum transfers in a relativistic Hartree approximation in configuration space. We treat the excitation of the $\\Delta$ resonance using its free mass and width. Good agreement with experiment is found in the dip region.

  4. PARAMETRIC DESIGN OF DELTA ROBOT

    Directory of Open Access Journals (Sweden)

    Mert Gürgen

    2016-09-01

    Full Text Available This article describes a sophisticated determination and presentation of a workspace volume for a delta robot, with consideration of its kinematic behavior. With the help of theoretical equations, optimization is performed with the aid of the stiffness and dexterity analysis. Theoretical substructure is coded in Matlab and three-dimensional (3D data for delta robot are developed in computer-aided design (CAD environment. In later stages of the project, both 3D and theoretical data are linked together and thus, with the changing design parameter of the robot itself, the Solidworks CAD output adapts and regenerates output with a new set of parameters. To achieve an optimum workspace volume with predefined parameters, a different set of robot parameters are iterated through design optimization in Matlab, and the delta robot design is finalized and illustrated in the 3D CAD environment, Solidworks. This study provides a technical solution to accomplish a generic delta robot with optimized workspace volume.

  5. Multimode delta-E effect magnetic field sensors with adapted electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, Sebastian; Fichtner, Simon; Kirchhof, Christine; Quandt, Eckhard; Faupel, Franz, E-mail: ff@tf.uni-kiel.de [Faculty of Engineering, Institute for Materials Science, Kiel University, Kaiserstraße 2, 24143 Kiel (Germany); Reermann, Jens; Schmidt, Gerhard [Faculty of Engineering, Institute for Electrical Engineering, Kiel University, Kaiserstraße 2, 24143 Kiel (Germany); Wagner, Bernhard [Fraunhofer Institute for Silicon Technology ISIT, Fraunhoferstraße 1, 25524 Itzehoe (Germany)

    2016-05-30

    We present an analytical and experimental study on low-noise piezoelectric thin film resonators that utilize the delta-E effect of a magnetostrictive layer to measure magnetic fields at low frequencies. Calculations from a physical model of the electromechanical resonator enable electrode designs to efficiently operate in the first and second transversal bending modes. As predicted by our calculations, the adapted electrode design improves the sensitivity by a factor of 6 and reduces the dynamic range of the sensor output by 16 dB, which significantly eases the requirements on readout electronics. Magnetic measurements show a bandwidth of 100 Hz at a noise level of about 100 pTHz{sup −0.5}.

  6. Multimode delta-E effect magnetic field sensors with adapted electrodes

    Science.gov (United States)

    Zabel, Sebastian; Reermann, Jens; Fichtner, Simon; Kirchhof, Christine; Quandt, Eckhard; Wagner, Bernhard; Schmidt, Gerhard; Faupel, Franz

    2016-05-01

    We present an analytical and experimental study on low-noise piezoelectric thin film resonators that utilize the delta-E effect of a magnetostrictive layer to measure magnetic fields at low frequencies. Calculations from a physical model of the electromechanical resonator enable electrode designs to efficiently operate in the first and second transversal bending modes. As predicted by our calculations, the adapted electrode design improves the sensitivity by a factor of 6 and reduces the dynamic range of the sensor output by 16 dB, which significantly eases the requirements on readout electronics. Magnetic measurements show a bandwidth of 100 Hz at a noise level of about 100 pTHz-0.5.

  7. Forecasting the Cumulative Impacts of Dams on the Mekong Delta: Certainties and Uncertainties

    Science.gov (United States)

    Kondolf, G. M.; Rubin, Z.; Schmitt, R. J. P.

    2016-12-01

    The Mekong River basin is undergoing rapid hydroelectric development, with 7 large mainstem dams on the upper Mekong (Lancang) River in China and 133 dams planned for the Lower Mekong River basin (Laos, Cambodia, Thailand, Vietnam), 11 of which are on the mainstem. Prior analyses have shown that all these dams built as initially proposed would trap 96% of the natural sediment load to the Mekong Delta. Such a reduction in sediment supply would compromise the sustainability of the delta itself, but there are many uncertainties in the timing and pattern of land loss. The river will first erode in-channel sediment deposits, partly compensating for upstream sediment trapping until these deposits are exhausted. Other complicating factors include basin-wide accelerated land-use change, road construction, instream sand mining, dyking-off floodplains, and changing climate, accelerated subsidence from groundwater extraction, and sea level rise. It is certain that the Mekong Delta will undergo large changes in the coming decades, changes that will threaten its very existence. However, the multiplicity of compounding drivers and lack of good data lead to large uncertainties in forecasting changes in the sediment balance on the scale of a very large network. We quantify uncertainties in available data and consider changes due to additional, poorly quantified drivers (e.g., road construction), putting these drivers in perspective with the overall sediment budget. We developed a set of most-likely scenarios and their implications for the delta's future. Uncertainties are large, but there are certainties about the delta's future. If its sediment supply is nearly completely cut off (as would be the case with `business-as-usual' ongoing dam construction and sediment extraction), the Delta is certainly doomed to disappear in the face of rising seas, subsidence, and coastal erosion. The uncertainty is only when and how precisely the loss will progress.

  8. Exporting and Productivity: Learning from Vietnam

    DEFF Research Database (Denmark)

    Newman, Carol; Rand, John; Tarp, Finn;

    2017-01-01

    different policy stance than typical in Africa. This is especially so in promoting export-oriented industry. If learning by exporting is a key driver of progress, then a fundamental reason for Africa's lack of transformation is likely to be the low policy priority given to export promotion in the past....... To enlarge the body of empirical evidence, we use an extensive 2005–2012 firm-level panel data set from Vietnam and separate out productivity effects of exporting due to self-selection. This allows us to conclude that firms actually learn by exporting. We also examine how this learning takes place. Our...... findings suggest that productivity gains are associated with moving to larger scale for foreign-owned firms with little evidence of subsequent learning on export markets. We find strong evidence to suggest that private domestic firms learn and accumulate knowledge from export markets with learning...

  9. Political Connections and Investment in Rural Vietnam

    DEFF Research Database (Denmark)

    Markussen, Thomas; Tarp, Finn

    as a result of relatives moving into public office. Connections to office holders appear to be important for investment because they strengthen de facto land property rights and improve access to off-farm employment and to informal loans. The findings underline the importance of informal networks for economic......This paper uses household panel data from rural Vietnam to explore the effects of having a relative in a position of political or bureaucratic power on farmers’ agricultural investment decisions. Our main result is that households significantly increase their investment in land improvement...... behaviour in environments with developing institutions and markets. They also suggest the presence of an untapped potential for economic development: if households without connections could obtain equally strong property rights and access to credit and insurance as the well-connected households, investment...

  10. Recent progress in radioisotope production in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Le Van So [Radioisotope Dept., Nuclear Research Institute, Dalat (Viet Nam)

    1998-10-01

    This is a report on the recent progress in radioisotope production in Vietnam. Using a nuclear research reactor of 500 KW with continuous operation cycles of 100 hours a month, the production of some important radioisotopes used in nuclear medicine and research was routinely carried out. More than 80 per cent of irradiation capacity of reactor for radioisotope production were exploited. The radioactivity of more than 150 Ci of {sup 131}I, {sup 99}Mo-{sup 99m}Tc, {sup 32}P, {sup 51}Cr, {sup 153}Sm, {sup 46}Sc, {sup 192}Ir was produced annually. Radiopharmaceuticals such as {sup 131}I-Hippuran and in-vivo Kits for {sup 99m}Tc labelling were also prepared routinely and regularly. More than 10 in-vivo Kits including modern radiopharmaceuticals such as HmPAO kit were supplied to hospitals in Vietnam. The research on the improvement of dry distillation technology for production of {sup 131}I was carried out. As a result obtained a new distillation apparatus made from glass was successfully put to routine use in place of expensive quartz distillation furnace. We have also continued the research programme on the development of {sup 99m}Tc generators using low power research reactors. Gel technology using Zr- and Ti- molybdate gel columns for {sup 99m}Tc generator production was developed and improved continually. Portable {sup 99m}Tc generator using Zr-({sup 99}Mo) molybdate gel column and ZISORB adsorbent column for {sup 99m}Tc concentration were developed. The ZISORB adsorbent of high adsorption capacity for {sup 99}Mo and other parent radionuclides was also studied for the development purpose of alternative technology of {sup 99m}Tc and other different radionuclide generator systems. The studies on the preparation of therapeutic radiopharmaceuticals labelling with {sup 153}Sm and {sup 131}I such as {sup 153}Sm-EDTMP, {sup 131}I-MIBG were carried out. (author)

  11. Nutrient dynamics in mangrove areas of the Red River Estuary in Vietnam

    Science.gov (United States)

    Wösten, J. H. M.; de Willigen, P.; Tri, N. H.; Lien, T. V.; Smith, S. V.

    2003-05-01

    Nutrient dynamics of mangrove in the 107 km 2 large estuary of the Red River Delta in Vietnam are studied using the existing LOICZ-CABARET budget model. The methodology and assumptions underlying this model are described. Input data for evaporation, rainfall, river discharge, and concentrations of salt, phosphorus and nitrogen are obtained during measurement campaigns in Vietnam. The calculated P-balance of the estuary together with measured data on the C/P ratio of mangroves yield a calculated mangrove biomass growth rate of 80 kg dry matter ha -1 d -1. Direct measurements of mangrove growth show a rate of 31 kg dry matter ha -1 d -1. Considering the uncertainties involved in this study where nutrient exchange with mineral particles is ignored, the nutrient budget model established for the Red River Estuary proves to give acceptable results. The model demonstrates that the mangroves in the estuary act as clear sinks of nutrients and sequester some 26 000 kg N d -1 and some 3100 kg P d -1 for their biomass production. Next the model is used in an explorative way to investigate effects of realistic future scenarios. Increasing river discharge in combination with constant or proportionally increasing river nutrient concentration results in increasing nutrient concentrations in the estuary. Increasing river discharge in combination with decreasing river nutrient concentration results in decreasing nutrient concentrations in the estuary. Constant river discharge in combination with increasing river nutrient concentration results in increasing nutrient concentrations in the estuary. The scenario analysis helps to understand the different interactions in the nutrient dynamics of the Red River mangrove area.

  12. Electromagnetic excitation of the delta resonance in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, J.S.; Dodge, W.R.; Lightbody J.W. Jr.; Maruyama, X.K.; Adler, J.h.; Hansen, K.; Schro-dash-barder, B.; Bernstein, A.M.; Blomqvist, K.I.; Cottman, B.H.; and others

    1987-03-01

    Inclusive cross sections for the proton and nuclear targets of A = 4, 9, 12, and 16 were measured for 537 and 730 MeV electrons scattered at 37.1 deg. Systematic features of the continuum scattering data are compared with other electron scattering data and with photoabsorption measurements. A model calculation based on the isobar-hole formalism is compared with the data in the delta resonance region.

  13. Delta-Sigma Modulated Photodetection Method to Reduce Laser Power Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This delta-sigma technique may be thought of as a form of analog-to-digital converter (ADC). The proposed network offers a means of processing electronic signals...

  14. Identifying and Improving the image of Vietnam Tourism as a Tourism destination among Finnish tourist

    OpenAIRE

    Pham, Anh Van

    2012-01-01

    This writing attempts to identify the images of Vietnam as a tourism destination for Finnish tourists and suggests marketing solution for Vietnamese traveling company to improve the images of Vietnam by enhancing marketing activities in the Finnish market. Saigontourist Transportation Corporation (STC), Vietnam which is a commissioner of this thesis project, has provided updated information about the current situation of tourism in Vietnam as well as marketing activities of company durin...

  15. The Sixth Meeting of China-Vietnam People’s Forum Held in Nanning

    Institute of Scientific and Technical Information of China (English)

    Xu; Yan

    2015-01-01

    The CPA FFC,the China Vietnam Friendship Association(CVFA),Vietnam Union of Friendship Organizations(VUFO)and the Vietnam-China Friendship Association(VCFA)jointly held the Sixth Meeting of China-Vietnam People’s Forumin Nanning,capital of China’s Guangxi Zhuang Autonomous Region,from December1 to 3,2014,attracting delegates from political,economic,academic

  16. Advantages and Disadvantages in setting up and managing a Captive Center in Vietnam

    OpenAIRE

    Nguyen, An; Nguyen, Thanh

    2015-01-01

    This work concerns factors that Captive Centers would face when they operate in Vietnam. In other words, it purposes to perceive in detail what Vietnam offers to Captive Centers by identifying the advantages and disadvantages in establishing and managing Captive Centers in Vietnam from the perspective of foreign companies. Under the qualitative research method, the authors have done three interviews with the managers of two Captive Centers operating in Ho Chi Minh City, Vietnam, by sending th...

  17. Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers.

    Science.gov (United States)

    Rizzetto, M; Canese, M G; Aricò, S; Crivelli, O; Trepo, C; Bonino, F; Verme, G

    1977-01-01

    A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed delta, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and delta antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the delta antigen could be identified under the electron microscope. delta antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and delta antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera. Images Figure PMID:75123

  18. 77 FR 9701 - Steel Wire Garment Hangers From Taiwan And Vietnam

    Science.gov (United States)

    2012-02-17

    ... COMMISSION Steel Wire Garment Hangers From Taiwan And Vietnam Determinations On the basis of the record \\1... injured by reason of imports from Taiwan and Vietnam of steel wire garment hangers, provided for in... the United States at less than fair value (LTFV) and steel wire garment hangers from Vietnam that...

  19. 78 FR 8105 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Antidumping Duty Order

    Science.gov (United States)

    2013-02-05

    ... International Trade Administration Steel Wire Garment Hangers From the Socialist Republic of Vietnam... order on steel wire garment hangers from the Socialist Republic of Vietnam (``Vietnam''). DATES... sales at less than fair value in the antidumping duty investigation of steel wire garment hangers...

  20. 75 FR 57501 - Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam

    Science.gov (United States)

    2010-09-21

    ... COMMISSION Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam AGENCY: United States... orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam. SUMMARY: The... orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam would be likely...

  1. 75 FR 60730 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping...

    Science.gov (United States)

    2010-10-01

    ... International Trade Administration Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam... antidumping duty order on certain frozen warmwater shrimp (``shrimp'') from the Socialist Republic of Vietnam...: Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam, 70 FR 5152 (February 1,...

  2. 75 FR 48724 - Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam

    Science.gov (United States)

    2010-08-11

    ... COMMISSION Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam AGENCY: United States... orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam. SUMMARY: The... orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam would be likely...

  3. U.S.-Vietnam Economic and Trade Relations: Issues for the 111th Congress

    Science.gov (United States)

    2010-05-03

    9 The Vietnam-U.S. Textile Agreement of 2003 ..................................................................... 10...interest in joining the TPP was quickly followed by similar expressions of interest by Australia, Peru , and Vietnam. In the President’s 2009 Annual...separate bilateral textile agreement and later in the form of a unilateral monitoring program that expired in January 2009.28 In both cases, Vietnam

  4. 75 FR 22842 - Polyethylene Retail Carrier Bags From Indonesia, Taiwan, and Vietnam

    Science.gov (United States)

    2010-04-30

    ... COMMISSION Polyethylene Retail Carrier Bags From Indonesia, Taiwan, and Vietnam Determinations On the basis... imports from Vietnam of polyethylene retail carrier bags (PRCBs), provided for in subheading 3923.21.00 of... Commerce (Commerce) to be subsidized by the Government of Vietnam.\\2\\ The Commission further...

  5. Stratification and the Emergence of the Postsecondary Private Education Sector in Vietnam

    Science.gov (United States)

    Goyette, Kimberly Ann

    2012-01-01

    Vietnam has a strong public postsecondary education sector that has only recently begun to experience growth in nonpublic institutions. I investigate how the growth of nonpublic institutions may be related to stratification in Vietnam. I find that these institutions are more likely to serve more advantaged students from South Vietnam. Students pay…

  6. 77 FR 9700 - Utility Scale Wind Towers From China and Vietnam

    Science.gov (United States)

    2012-02-17

    ... COMMISSION Utility Scale Wind Towers From China and Vietnam Determinations On the basis of the record \\1... with material injury by reason of imports from Vietnam of utility scale wind towers, provided for in... wind towers from China and Vietnam. Accordingly, effective December 29, 2011, the Commission...

  7. 77 FR 39613 - Presidential Determination on a U.S. Export Import Bank Transaction with Vietnam

    Science.gov (United States)

    2012-07-03

    ...--Presidential Determination on a U.S. Export-Import Bank Transaction With Vietnam #0; #0; #0; Presidential... Presidential Determination on a U.S. Export Import Bank Transaction with Vietnam Memorandum for the Secretary... States to extend a loan in the amount of approximately $125,870,890 to the Vietnam Post...

  8. 78 FR 45271 - Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam

    Science.gov (United States)

    2013-07-26

    ... COMMISSION Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam Determination On the... injured by reason of imports from Malaysia, Thailand, and Vietnam of welded stainless steel pressure pipe... pipe from Malaysia, Thailand, and Vietnam. Accordingly, effective May 16, 2013, the...

  9. 78 FR 10210 - Utility Scale Wind Towers From China and Vietnam

    Science.gov (United States)

    2013-02-13

    ... COMMISSION Utility Scale Wind Towers From China and Vietnam Determinations On the basis of the record \\1... with material injury by reason of imports of utility scale wind towers from China and Vietnam, provided... of imports of utility scale wind towers from China and Vietnam. Commissioner Dean A....

  10. Tentative checklist of the mosquitoes of Vietnam employing new classification for tribe Aedini (Diptera, Culicidae).

    Science.gov (United States)

    Bui, Phuong; Darsie, Richard F

    2008-06-01

    The new classification of tribe Aedini is used in a tentative checklist of the mosquitoes found in Vietnam, which contains 34 genera, 28 subgenera, and 191 species and subspecies. Mosquito-borne diseases in Vietnam are mentioned. Mosquito records from U.S. military sources during the Vietnam War are also considered.

  11. Structural Insights into Clostridium perfringens Delta Toxin Pore Formation.

    Science.gov (United States)

    Huyet, Jessica; Naylor, Claire E; Savva, Christos G; Gibert, Maryse; Popoff, Michel R; Basak, Ajit K

    2013-01-01

    Clostridium perfringens Delta toxin is one of the three hemolysin-like proteins produced by C. perfringens type C and possibly type B strains. One of the others, NetB, has been shown to be the major cause of Avian Nectrotic Enteritis, which following the reduction in use of antibiotics as growth promoters, has become an emerging disease of industrial poultry. Delta toxin itself is cytotoxic to the wide range of human and animal macrophages and platelets that present GM2 ganglioside on their membranes. It has sequence similarity with Staphylococcus aureus β-pore forming toxins and is expected to heptamerize and form pores in the lipid bilayer of host cell membranes. Nevertheless, its exact mode of action remains undetermined. Here we report the 2.4 Å crystal structure of monomeric Delta toxin. The superposition of this structure with the structure of the phospholipid-bound F component of S. aureus leucocidin (LukF) revealed that the glycerol molecules bound to Delta toxin and the phospholipids in LukF are accommodated in the same hydrophobic clefts, corresponding to where the toxin is expected to latch onto the membrane, though the binding sites show significant differences. From structure-based sequence alignment with the known structure of staphylococcal α-hemolysin, a model of the Delta toxin pore form has been built. Using electron microscopy, we have validated our model and characterized the Delta toxin pore on liposomes. These results highlight both similarities and differences in the mechanism of Delta toxin (and by extension NetB) cytotoxicity from that of the staphylococcal pore-forming toxins.

  12. Potential economic corridors between Vietnam and Lao PDR: Roles played by Vietnam

    OpenAIRE

    Nguyen, Binh Giang

    2012-01-01

    The Third Thai-Lao Friendship over the Mekong officially opened on 11th November 2011 facilitates the cross-border trade along Asian Highway 15 and Asian Highway 131 between Northeast Thailand, Central Lao PDR and North Central Vietnam. Since the establishment of East-West Economic Corridor (EWEC) which based on the Asian Highway 16, the cross-border trade among countries in Greater Mekong Sub-region has been much facilitated. The success of EWEC encourages local governments in the region to...

  13. 77 FR 75980 - Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Final Determination of Sales...

    Science.gov (United States)

    2012-12-26

    ... International Trade Administration Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Final... antidumping investigation of steel wire garment hangers from the Socialist Republic of Vietnam (``Vietnam... continue to determine that steel wire garment hangers from Vietnam are being, or are likely to be, sold...

  14. 78 FR 8107 - Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Countervailing Duty Order

    Science.gov (United States)

    2013-02-05

    ... International Trade Administration Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam... order on certain steel wire garment hangers from the Socialist Republic of Vietnam (Vietnam). DATES... duty investigation of certain steel wire garment hangers from Vietnam.\\1\\ On January 28, 2013, the...

  15. The Vietnam Drug User Returns. Final Report. Special Action Office Monograph, Series A, Number 2, May 1974.

    Science.gov (United States)

    Robins, Lee N.

    This report, based upon case records and follow-up interviews with 965 U.S. Servicemen returning from Vietnam investigates: (1) the availability and utilization of narcotics, marihuana and alcohol in Vietnam; (2) the psychosocial and demographic predictors of pre- and post-Vietnam narcotic use; and (3) the post-Vietnam adjustment difficulties of…

  16. Sister Lab Program Prospective Partner Nuclear Profile: Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Bissani, M; Tyson, S

    2006-12-14

    Vietnam's nuclear program began in the 1960s with the installation at Dalat of a 250 kW TRIGA Mk-II research reactor under the U.S. Atoms for Peace Program. The reactor was shut down and its core removed only a few years later, and the nuclear research program was suspended until after the end of the civil war in the late 1970s. The Soviet Union assisted Vietnam in restoring the Dalat reactor to an operational status in 1984, trained a cadre of scientific and technical staff in its operation, and contributed to the development of nuclear science for the medical and agricultural sectors. In the agricultural area in particular, Vietnamese experts have been very successful in developing mutant strains of rice, and continue to work with the IAEA to yield strains that have a shorter growing period, increased resistance to disease, and other desirable characteristics. Rice has always been the main crop in Vietnam, but technical cooperation with the IAEA and other states has enabled the country to become one of the top rice producers in the world, exporting much of its annual crop to over two dozen countries annually. More recently, Vietnam's government has shown increasing interest in developing a civil nuclear program to supplement its fossil fuel and other energy resources. Projections from a variety of open sources, ranging from the IAEA, the U.S. Department of Energy's Energy Information Administration (EIA), the Vietnamese government, energy corporations, and think tanks all predict a massive increase in energy consumption--especially electricity--within Vietnam and the region as a whole. This growth in consumption will require a corresponding increase in energy production, which in Vietnam is currently satisfied mainly by fossil fuels (coal) and renewable energy (hydropower and biomass); Vietnam has a refining capacity of about 800 barrels/day. Most of its crude oil is exported to generate export income, and is not used to generate electricity

  17. Student Difficulties with the Dirac Delta Function

    CERN Document Server

    Wilcox, Bethany R

    2014-01-01

    The Dirac delta function is a standard mathematical tool used in multiple topical areas in the undergraduate physics curriculum. While Dirac delta functions are usually introduced in order to simplify a problem mathematically, students often struggle to manipulate and interpret them. To better understand student difficulties with the delta function at the upper-division level, we examined responses to traditional exam questions and conducted think-aloud interviews. Our analysis was guided by an analytical framework that focuses on how students activate, construct, execute, and reflect on the Dirac delta function in physics. Here, we focus on student difficulties using the delta function to express charge distributions in the context of junior-level electrostatics. Challenges included: invoking the delta function spontaneously, constructing two- and three-dimensional delta functions, integrating novel delta function expressions, and recognizing that the delta function can have units.

  18. Taxonomy and conservation of Vietnam's primates: a review.

    Science.gov (United States)

    Blair, Mary E; Sterling, Eleanor J; Hurley, Martha M

    2011-11-01

    Vietnam has the highest number of primate taxa overall (24-27) and the highest number of globally threatened primate taxa (minimum 20) in Mainland Southeast Asia. Conservation management of these species depends in part on resolving taxonomic uncertainties, which remain numerous among the Asian primates. Recent research on genetic, morphological, and acoustic diversity in Vietnam's primates has clarified some of these uncertainties, although a number of significant classification issues still remain. Herein, we summarize and compare the major current taxonomic classifications of Vietnam's primates, discuss recent advances in the context of these taxonomies, and suggest key areas for additional research to best inform conservation efforts in a region crucial to global primate diversity. Among the most important next steps for the conservation of Vietnam's primates is a new consensus list of Asian primates that resolves current differences between major taxonomies, incorporates recent research advances, and recognizes units of diversity at scales below the species-level, whether termed populations, morphs, or subspecies. Priority should be placed on recognizing distinct populations, regardless of the species concept in use, in order to foster the evolutionary processes necessary for primate populations to cope with inevitable environmental changes. The long-term conservation of Vietnam's primates depends not only on an accepted and accurate taxonomy but also on funding for on-the-ground conservation activities, including training, and the continued dedication and leadership of Vietnamese researchers and managers.

  19. Estimating the extra cost of living with disability in Vietnam.

    Science.gov (United States)

    Minh, Hoang Van; Giang, Kim Bao; Liem, Nguyen Thanh; Palmer, Michael; Thao, Nguyen Phuong; Duong, Le Bach

    2015-01-01

    Disability is shown to be both a cause and a consequence of poverty. However, relatively little research has investigated the economic cost of living with a disability. This study reports the results of a study on the extra cost of living with disability in Vietnam in 2011. The study was carried out in eight cities/provinces in Vietnam, including Hanoi and Ho Chi Minh cities (two major metropolitan in Vietnam) and six provinces from each of the six socio-economic regions in Vietnam. Costs are estimated using the standard of living approach whereby the difference in incomes between people with disability and those without disability for a given standard of living serves as a proxy for the cost of living with disability. The extra cost of living with disability in Vietnam accounted for about 8.8-9.5% of annual household income, or valued about US$200-218. Communication difficulty was shown to result in highest additional cost of living with disability and self-care difficulty was shown to lead to the lowest levels of extra of living cost. The extra cost of living with disability increased as people had more severe impairment. Interventions to promote the economic security of livelihood for people with disabilities are needed.

  20. Breastfeeding practices in urban and rural Vietnam

    Directory of Open Access Journals (Sweden)

    Thu Huong

    2012-11-01

    Full Text Available Abstract Background The aim of this study was to describe and compare breastfeeding practices in rural and urban areas of Vietnam and to study associations with possibly influencing person and household factors. This type of study has not been conducted in Vietnam before. Methods Totally 2,690 children, born from 1st March 2008 to 30th June 2010 in one rural and one urban Health and Demographic Surveillance Site, were followed from birth to the age of 12 months. Information about demography, economy and education for persons and households was obtained from household surveys. Standard statistical methods including survival and regression analyses were used. Results Initiation of breastfeeding during the first hour of life was more frequent in the urban area compared to the rural (boys 40% vs. 35%, girls 49% vs. 40%. High birth weight and living in households with large number of assets significantly increased the probability for early initiation of breastfeeding. Exclusive breastfeeding at three months of age was more commonly reported in the rural than in the urban area (boys 58% vs. 46%, girls 65% vs. 53%. The duration of exclusive breastfeeding as well as of any breastfeeding was longer in the rural area than in the urban area (medians for boys 97 days vs. 81 days, for girls 102 days vs. 91 days. The percentages of children with exclusive breastfeeding lasting at least 6 months, as recommended by WHO, were low in both areas. The duration of exclusive breastfeeding was significantly shorter for mothers with three or more antenatal care visits or Caesarean section in both areas. High education level of mothers was associated with longer duration of exclusive breastfeeding in the rural area. No significant associations were found between duration of exclusive breastfeeding and mother’s age, household economy indicators or household size. Conclusion Intervention programs with the aim to promote breastfeeding are needed. Mothers should

  1. {Delta}I = 3/2 and {Delta}S = 2 Hyperon decays in chiral perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    He, X.G. [University of Melbourne, Parkville, VIC (Australia). School of Physics; Valencia, G. [Iowa State University, Ames, Iowa (United States). Department of Physics and Astronomy

    1997-05-01

    We study the| {Delta}I| = 3/2 and |{Delta}S| = 2 amplitudes for hyperon decays of the form B {yields} B`{pi} at lowest order in chiral perturbation theory. At this order, the {Delta}I = 3/2 amplitudes depend on only one constant. We extract the value of this constant from experiment and find a reasonable description of these processes within experimental errors. The same constant determines the {Delta}S = 2 transitions which, in the standard model, are too small to be observed. We find that new physics with parity odd {Delta}S = 2 interactions can produce observable rates in hyperon decays while evading the bounds from K{sup 0} - K-bar{sup 0} mixing. (authors) 10 refs., 3 tabs.

  2. A review of foodborne bacterial and parasitic zoonoses in Vietnam.

    Science.gov (United States)

    Carrique-Mas, Juan J; Bryant, J E

    2013-12-01

    Vietnam has experienced unprecedented economic and social development in recent years, and the livestock sector is undergoing significant transformations. Although food animal production is still dominated by small-scale 'backyard' enterprises with mixed crop-livestock or livestock-aquatic systems, there is a trend towards more intensive and vertically integrated operations. Changes in animal production, processing and distribution networks for meat and animal products, and the shift from wet markets to supermarkets will undoubtedly impact food safety risks in Vietnam in unforeseen and complex ways. Here, we review the available published literature on bacterial and parasitic foodborne zoonoses (FBZ) in Vietnam. We report on clinical disease burden and pathogen prevalence in animal reservoirs for a number of important FBZ, and outline opportunities for future research.

  3. The pursuit of sustainable livelihoods in Vietnam's Northern uplands

    DEFF Research Database (Denmark)

    Thulstrup, Andreas Waaben

    Despite remarkable achievements in economic growth and poverty reduction, disparities between upland & lowland areas in Vietnam still exist. Numerous development programs have been implemented in upland areas but have frequently failed to achieve their objectives. The top-down approach of the gov......Despite remarkable achievements in economic growth and poverty reduction, disparities between upland & lowland areas in Vietnam still exist. Numerous development programs have been implemented in upland areas but have frequently failed to achieve their objectives. The top-down approach...... of the government & its failure to recognize both local informal institutions & the strategies that shape household decision-making has produced unintended results. International NGOs have started working and delivering services in rural areas of Vietnam. Unlike government intervention, NGOs often employ a bottom...

  4. Extreme floods in the Mekong River Delta under climate change: combined impacts of upstream hydrological changes and sea level rise

    Science.gov (United States)

    Hoang, Long; Nguyen Viet, Dung; Kummu, Matti; Lauri, Hannu; Koponen, Jorma; van Vliet, Michelle T. H.; Supit, Iwan; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2016-04-01

    Extreme floods cause huge damages to human lives and infrastructure, and hamper socio-economic development in the Mekong River Delta in Vietnam. Induced by climate change, upstream hydrological changes and sea level rise are expected to further exacerbate future flood hazard and thereby posing critical challenges for securing safety and sustainability. This paper provides a probabilistic quantification of future flood hazard for the Mekong Delta, focusing on extreme events under climate change. We developed a model chain to simulate separate and combined impacts of two drivers, namely upstream hydrological changes and sea level rise on flood magnitude and frequency. Simulation results show that upstream changes and sea level rise substantially increase flood hazard throughout the whole Mekong Delta. Due to differences in their nature, two drivers show different features in their impacts on floods. Impacts of upstream changes are more dominant in floodplains in the upper delta, causing an increase of up to +0.80 m in flood depth. Sea level rise introduces flood hazard to currently safe areas in the middle and coastal delta zones. A 0.6 m rise in relative sea level causes an increase in flood depth between 0.10 and 0.70 m, depending on location by 2050s. Upstream hydrological changes and sea level rise tend to intensify each other's impacts on floods, resulting in stronger combined impacts than linearly summed impacts of each individual driver. Substantial increase of future flood hazard strongly requires better flood protection and more flood resilient development for the Mekong Delta. Findings from this study can be used as quantified physical boundary conditions to develop flood management strategies and strategic delta management plans.

  5. Reactive versus anticipative adaptive management of Deltas: The Sacramento-San Joaquin Delta and the Rhine-Meuse Delta compared

    NARCIS (Netherlands)

    Vlieg, T.J.; Zandvoort, M.

    2013-01-01

    In this paper Californian Adaptive Management (AM) and Dutch Adaptive Delta Management (ADM) are compared. The concepts are introduced in a policy context to deal with prevailing types of uncertainty in water management in the Californian Sacramento-San Joaquin Delta and the Dutch Rhine-Meuse Delta

  6. Facts About Delta Pi Epsilon

    Science.gov (United States)

    Delta Pi Epsilon Journal, 1976

    1976-01-01

    The article discusses the purpose and structure of Delta Pi Epsilon and the general qualifications for membership. Service projects and publications, research awards, timely facts, the year of each chapter's origination, national presidents, and executive secretaries for the last 40 years are listed. (BP)

  7. Ensemble climate projections of mean and extreme rainfall over Vietnam

    Science.gov (United States)

    Raghavan, S. V.; Vu, M. T.; Liong, S. Y.

    2017-01-01

    A systematic ensemble high resolution climate modelling study over Vietnam has been performed using the PRECIS model developed by the Hadley Center in UK. A 5 member subset of the 17-member Perturbed Physics Ensembles (PPE) of the Quantifying Uncertainty in Model Predictions (QUMP) project were simulated and analyzed. The PRECIS model simulations were conducted at a horizontal resolution of 25 km for the baseline period 1961-1990 and a future climate period 2061-2090 under scenario A1B. The results of model simulations show that the model was able to reproduce the mean state of climate over Vietnam when compared to observations. The annual cycles and seasonal averages of precipitation over different sub-regions of Vietnam show the ability of the model in also reproducing the observed peak and magnitude of monthly rainfall. The climate extremes of precipitation were also fairly well captured. Projections of future climate show both increases and decreases in the mean climate over different regions of Vietnam. The analyses of future extreme rainfall using the STARDEX precipitation indices show an increase in 90th percentile precipitation (P90p) over the northern provinces (15-25%) and central highland (5-10%) and over southern Vietnam (up to 5%). The total number of wet days (Prcp) indicates a decrease of about 5-10% all over Vietnam. Consequently, an increase in the wet day rainfall intensity (SDII), is likely inferring that the projected rainfall would be much more severe and intense which have the potential to cause flooding in some regions. Risks due to extreme drought also exist in other regions where the number of wet days decreases. In addition, the maximum 5 day consecutive rainfall (R5d) increases by 20-25% over northern Vietnam but decreases in a similar range over the central and southern Vietnam. These results have strong implications for the management water resources, agriculture, bio diversity and economy and serve as some useful findings to be

  8. Exporting a Scandinavian Learning Model to Egypt and Vietnam

    DEFF Research Database (Denmark)

    Youssef, Sandra Safwat; Bygholm, Ann; Jæger, Kirsten

    2013-01-01

    many challenges. In this paper, we will present findings from an ethnographic study of the learning systems in higher education in Denmark, Egypt and Vietnam. The sample includes undergraduate level classes taught in Denmark, Egypt and Vietnam. The selected learning setting include an 'Academic......The recent advances in technology have made the process of exporting Western education more easy, and Blended Learning techniques is often the method of choice for exported educational programs. Although, in theory, this make perfect sense, yet in practice, the export of education has encountered...

  9. Formal and informal credit in four provinces of Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel; Tarp, Finn

    2008-01-01

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in Vietnam. Households obtain credit through formal and informal lenders. Formal loans are almost entirely for production and asset accumulation, while informal loans are used for consumption...... smoothening. The determinants of formal and informal credit demand are distinct. While credit rationing depends on education and credit history, in particular, regional differences in the demand for credit are striking. A 'one size fits all' approach to credit policy in Vietnam would be inappropriate...

  10. Childhood disability and parental moral responsibility in northern Vietnam

    DEFF Research Database (Denmark)

    Gammeltoft, Tine

    2008-01-01

    This article explores the roles played by parents living in Hanoi, Vietnam, in shaping the subjectivities of children who are categorized as physically or intellectually impaired. In an effort to comprehend disability in terms of an active and embodied engagement with the world, I employ...... a phenomenologically inspired 'intercorporeal' perspective as a conceptual alternative to 'medical' and 'social' models of disability. Through this approach I show how, in northern Vietnam, disability in children brings into question the moral integrity of their parents and how this compels parents to define...

  11. Supplement to Vietnam 1964-1973: An American Dilemma

    Science.gov (United States)

    2005-10-01

    T48 T78 1994) Vick, Alan . Snakes in the Eagle’s Nest; A FHistory of Ground Attacks on Air Bases. Santa Monica, CA: Rand Corp, 1995. (Report Lit RAND-MR...Return of Rambo: War and Culture in the Post-Vietnam Era." In America at Century’s End. Ed. Alan Wolfe. Berkeley: University of California Pr, 1991. 376...3-57. (Gov Doc D 114.2: J89) Brinkley , Douglas. Tour of Duty: John Kerry and the Vietnam War. New York: William Morrow, 2004. (E 840.8 .K427 B75 2004

  12. Globalization Crises, Trade,and Development in Vietnam

    DEFF Research Database (Denmark)

    Abbott, Philip; Tarp, Finn

    Vietnam has been among the most successful East Asian economies, especially in weathering the external shocks of recent globalization crises—the 1997-98 Asian financial crisis and the 2008-09 great recession, financial crisis and collapse of global trade. Its success contradicts its characterizat......Vietnam has been among the most successful East Asian economies, especially in weathering the external shocks of recent globalization crises—the 1997-98 Asian financial crisis and the 2008-09 great recession, financial crisis and collapse of global trade. Its success contradicts its...

  13. Hydrological and Climatic Significance of Martian Deltas

    Science.gov (United States)

    Di Achille, G.; Vaz, D. A.

    2017-10-01

    We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

  14. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2010-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta. The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  15. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2011-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta.The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  16. On the modelling of river delta formation

    NARCIS (Netherlands)

    Geleynse, N.

    2013-01-01

    This thesis presents approaches to the modelling of river delta formation. In particular, it provides results of numerical stratigraphic-morphodynamic modelling of river delta formation under various environmental forcings.

  17. Adaptive delta management: Roots and branches

    NARCIS (Netherlands)

    Timmermans, J.S.; Haasnoot, M.; Hermans, L.M.; Kwakkel, J.H.; Rutten, M.M.; Thissen, W.A.H.

    2015-01-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy, metropoli

  18. Delta Vegetation and Land Use [ds292

    Data.gov (United States)

    California Department of Resources — Vegetation and land use are mapped for the approximately 725,000 acres constituting the Legal Delta portion of the Sacramento and San Joaquin River Delta area....

  19. EVALUATION OF THE TRADE RELATIONSHIP BETWEEN VIETNAM AND CHINA; VIETNAM AND UNITED STATES: A COMPARISON USING GRAVITY MODEL

    Directory of Open Access Journals (Sweden)

    Lien Thi Dinh

    2017-06-01

    Full Text Available This study aims to evaluate the determinants of trade relationship between two largest trading partners of Vietnam, United States and China. Using gravity model for time series data from 1986 to 2015, the study found that economic growth rate plays a crucial role in stimulating the trade flow. Both trade relationships fit with the practical approach of Heckscher-Ohlin theory, stating that trade flow increases between countries with different income levels. The most important finding of this study lines on the results regarding the impact of trade agreements. While United States-Vietnam bilateral agreement creates trade, the trade agreement between ASEAN and China produced trade diversion. As China expands its markets among ASEAN countries, Vietnam should diversify its export markets to improve its export flow.

  20. Formation of aligned CrN nanoclusters in Cr-delta-doped GaN

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y K; Kimura, S; Emura, S; Hasegawa, S; Asahi, H [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)], E-mail: zhou21@sanken.osaka-u.ac.jp

    2009-02-11

    Cr-delta-doped GaN layers were grown by radio-frequency plasma-assisted molecular-beam epitaxy on GaN template substrates. Cr flux was supplied without nitrogen flow during Cr-delta-doping. Cr incorporation into a narrow thin layer region was confirmed with the depth profile measured by secondary ion mass spectrometry. Structural properties and Cr atom alignments were studied with transmission electron microscopy. It was found that Cr-delta-doped GaN layers were coherently grown with Cr or CrGa nanoclusters in the delta-doped region for low temperature growth (350, 500 deg. C). It was also found that aligned CrN nanoclusters (approximately 5 nm vertical thickness) with NaCl-type structure were formed in the delta-doped region for the growth at 700 deg. C.

  1. Reexamination of the Electronic Structure of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8 +{delta}} and Bi{sub 2}Sr{sub 2}Cu{sub 1}O{sub 6+{delta}} : Electronlike Portions of the Fermi Surface and Depletion of Spectral Weight near {bar M}

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Y.; Gromko, A.D.; Dessau, D.S. [Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States); Aiura, Y.; Yamaguchi, Y.; Oka, K. [Electrotechnical Laboratory (ETL), 1-1-4 Umezono, Tsukuba, Ibaraki 305 (Japan); Arko, A.J.; Joyce, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Eisaki, H.; Uchida, S.I. [Department of Superconductivity, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113 (Japan); Nakamura, K.; Ando, Y. [Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwato-Kita, Komae, Tokyo 201-8511 (Japan)

    1999-11-01

    We present a reexamination of the electronic structure and Fermi surface (FS) topology of Bi-Sr-Ca-Cu-O (BSCCO) as obtained from angle-resolved photoemission experiments. By applying a stricter set of FS crossing criteria as well as by varying the incident photon energy outside the usual range, we have found very different behavior from that previously observed. In particular, we have found a FS that is centered around the {Gamma} point and contains electronlike portions, and we observe a depletion of spectral weight around {bar M} . The flat bands observed at other photon energies may indicate the presence of two electronic components in the cuprates. {copyright} {ital 1999} {ital The American Physical Society }

  2. 福特-后福特二元生产系统下的企业创新行为——以珠江三角洲电子产业为例%Firm Innovation Behavior Under the Fordism-post Fordism Dual Production System: A Case Study of Electronics Industry in the Zhujiang River Delta

    Institute of Scientific and Technical Information of China (English)

    符文颖

    2013-01-01

    With the advent of knowledge economy,innovation has become the key element in growth and development.Ample literature in regional innovation system suggests that firm network under the support of knowledge-related institution underlies the success of clusters.In the innovation studies,firm-level innovation strategies and behaviors are among the most important aspects in investigating the regional innovation prospect.Unlike the mechanic comparison between regional innovation systems among places,this article begs the question of what constitutes the innovation drives for the clustering firms in the Zhujiang River Delta,China,where the Fordist production sector relocated by multi-national corporations is intricately intertwined with post-Fordist mode of flexible production among small and medium sized supplier firms.Based on a random-sampled electronics firm questionnaire survey in the Zhujiang River Delta,this article begins by analyzing the Fordist-post Fordist way of production system in terms of production network,labor market,financial system,innovation system and business mode in the Zhujiang River Delta,concluding a close-oriented Fordist character in labor market,financial system and innovation system with relatively flexible way of production and business relations under the support of social capital.The study further investigates the innovation mechanism within this context of production system by building a probit model.In the model,the effect of firm scale,R&D investment,CEO background,staff turnover rate and urbanization economies on firm innovation have been examined.Moreover,the model succeeds in differentiating the effect of these factors between four types of innovation,i.e.product innovation,process innovation,organizational innovation and market innovation.The results show that while the production relations among the firms has become more vertically fragmented and flexible,innovation activities still keep the Fordist "in-house" characteristic

  3. Comprehensive studies for the crystal structures and electronic properties of the superconducting system Fe1 + δSe1 - xTex with \\delta \\simeq 0.037 and x \\simeq 0.55

    Science.gov (United States)

    Onoda, Masashige; Kawasaki, Yasuna; Tsubokawa, Masashi; Koyano, Tamotsu

    2010-12-01

    Structural aspects and electronic properties for the Fe1 + δSe1 - xTex system with 0.04 125Te. The crystal structures with an excess Fe site are refined precisely with obvious constraints. For the superconducting composition, the transport properties are explained in terms of the two-band model, where an electron carrier band gives a linear-in-T resistivity and another hole band leads to nearly temperature-independent behaviour. The magnetic susceptibility and the Knight shift are explained with the idea that the electron correlation is enhanced with increasing x and it is reduced with annealing. The spin-lattice relaxation rates for the normal state that show the apparent Korringa relation may also be understood in this framework. These evidences suggest that the superconductivity may emerge in a regime where the correlation is relatively weak in this system.

  4. Limited junctional diversity of V delta 5-J delta 1 rearrangement in multiple sclerosis patients.

    Science.gov (United States)

    Nowak, J S; Michałowska-Wender, G; Januszkiewicz, D; Wender, M

    1997-01-01

    T-cell receptor (TCR) delta gene repertoire, as assessed by V delta-J delta rearrangements, has been analyzed in nine multiple sclerosis (MS) cases and in 30 healthy individuals by seminested PCR technique. Among the V delta-J delta junctional diversities studied, the most striking result has been observed in V delta 5-J delta 1 rearrangement. The detection of repeated V delta 5-J delta 1 nucleotide sequences in all analyzed clones from seven out of nine patients studied proved the monoclonal nature of gamma delta T-cells with V delta 5-J delta 1 rearrangement. The clonal nature of this rearrangement proved by PAGE and sequencing analysis may suggest an antigen-driven expansion of gamma delta T cells and argues for a significant role of gamma delta T-cells with V delta 5-J delta 1 rearrangement in MS pathogenesis. However, it cannot be excluded that clonal expansion of these lymphocytes may represent secondary change to central nervous system damage.

  5. Reflections on Development Strategy of Pearl River Delta: In Comparison with Yangtze River Delta

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>1. A comparison between Pearl River Delta and Yangtze River Delta 1.1 Basic conditions 1.1.1 Location, area and scope Located in the southeast of Guangdong Province, the Pearl River Delta (PRD) as an economic zone is a compound delta

  6. Poverty, economic growth, deprivation, and water: the cases of Cambodia and Vietnam.

    Science.gov (United States)

    Varis, Olli

    2008-05-01

    Poverty reduction decorates all development agendas, but the complexity of the poverty issue is too often hidden behind simplistic indicators and development goals. Here, a closer look is taken at the concepts of "deprivation" and "vulnerability" as outcomes of poverty. Deprivation leads typically to social exclusion and marginalization; such groups are particularly weak in getting themselves out of poverty by "self-help," and economic growth does not trickle down to these people. When looking at the connections between poverty reduction and economic growth, special emphasis should be put on the differences between modern and more traditional sectors: development of the modern sector should not marginalize and exclude those dependent on more traditional livelihoods. Two case studies--The Tonle Sap area, Cambodia, and the Mekong Delta, Vietnam--reveal that investment in education, empowerment of small-scale entrepreneurship and other means of microeconomic environment, along with good governance, infrastructure, and income distribution can ensure that economic growth includes the poorer echelons of society.

  7. Quality of Antimicrobial Products Used in Striped Catfish (Pangasianodon hypophthalmus) Aquaculture in Vietnam.

    Science.gov (United States)

    Phu, Tran Minh; Phuong, Nguyen Thanh; Scippo, Marie-Louise; Dalsgaard, Anders

    2015-01-01

    Antimicrobial usage is common in Asian aquaculture. This study aimed to determine the quality of antimicrobial products used by Vietnamese striped catfish (Pangasianodon hypophthalmus) farmers. Twenty one antimicrobial products (11 products contained a single antimicrobial and 10 products contained a mixture of two different antimicrobials) commonly used by catfish farmers were obtained from so-called chemical shops located in the Mekong Delta, Vietnam. Ultra High Performance Liquid Chromatography Mass Spectrometry was used to analyze concentration of sulfonamides, trimethoprim, amoxicillin, cefalexin and ciprofloxacin whereas concentrations of florfenicol and doxycycline were analyzed by High Performance Liquid Chromatography with UV detection. Results revealed that only 4/11 products with a single antimicrobial and 2/10 products with a mixture of antimicrobials contained active substances within ±10% of the concentration declared on the product label. Two products with antimicrobial mixtures did not contain any of the declared antimicrobials. Comparing two batches, analysis of 11 products revealed that only one product contained a concentration of active compound that varied with less than 10% in both batches. Several product labels provided inadequate information on how to calculate therapeutic dosage and further stated withdrawal time despite lack of pharmacokinetic data on the antimicrobials in catfish. There is an urgent need to strengthen approval procedures and in particular regularly to monitor the quality of antimicrobials used in Vietnamese aquaculture.

  8. Quality of Antimicrobial Products Used in Striped Catfish (Pangasianodon hypophthalmus Aquaculture in Vietnam.

    Directory of Open Access Journals (Sweden)

    Tran Minh Phu

    Full Text Available Antimicrobial usage is common in Asian aquaculture. This study aimed to determine the quality of antimicrobial products used by Vietnamese striped catfish (Pangasianodon hypophthalmus farmers. Twenty one antimicrobial products (11 products contained a single antimicrobial and 10 products contained a mixture of two different antimicrobials commonly used by catfish farmers were obtained from so-called chemical shops located in the Mekong Delta, Vietnam. Ultra High Performance Liquid Chromatography Mass Spectrometry was used to analyze concentration of sulfonamides, trimethoprim, amoxicillin, cefalexin and ciprofloxacin whereas concentrations of florfenicol and doxycycline were analyzed by High Performance Liquid Chromatography with UV detection. Results revealed that only 4/11 products with a single antimicrobial and 2/10 products with a mixture of antimicrobials contained active substances within ±10% of the concentration declared on the product label. Two products with antimicrobial mixtures did not contain any of the declared antimicrobials. Comparing two batches, analysis of 11 products revealed that only one product contained a concentration of active compound that varied with less than 10% in both batches. Several product labels provided inadequate information on how to calculate therapeutic dosage and further stated withdrawal time despite lack of pharmacokinetic data on the antimicrobials in catfish. There is an urgent need to strengthen approval procedures and in particular regularly to monitor the quality of antimicrobials used in Vietnamese aquaculture.

  9. Building Forecast Maps Of Water Quality For Main Rivers And Canals In Tien Giang Province, Vietnam

    Directory of Open Access Journals (Sweden)

    Anh Duc Pham

    2015-09-01

    Full Text Available This study aims to enhance the mapping of forecast for water quality assessment in Mekong Delta provinces. The data from 32 sites from main rivers and canals in an area of around 2,482 km2 in Tien Giang Province, Vietnam, were used for calculation and mapping. The ArcGIS 9.3 software, Inverse Distance Weighting (IDW interpolation method, hydrologic data, and water quality parameters in March (2010-2014 were applied to build the maps showing 2020 water quality predictions for main rivers and canals in Tien Giang Province. The estimation was based on the Water Quality Index (WQI with 6 parameters such as pH, total suspended solid (TSS, dissolved oxygen (DO, biochemical oxygen demand (BOD, total nitrogen (T_N, and coliform. The results showed that water quality in the studied area in dry season will not be improved by the year 2020. The finding could be a scientific reference for the selection of effective approaches to improve water quality in main rivers and canals in Tien Giang Province.

  10. A second species of Euscorpiops Vachon from caves in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae). Cave Euscorpiops scorpion from Vietnam.

    Science.gov (United States)

    Lourenço, Wilson R; Pham, Dinh-Sac

    2014-09-01

    Euscorpiops dakrong sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of one male and one female collected in the Dakrong Nature Reserve cave system, Dakrong District, Quang Tri Province, Vietnam. The new species presents most features exhibited by scorpions of the genus Euscorpiops, but it is characterized by a slender body and elongated pedipalps. This new scorpion taxon represents the second species of Scorpiopinae discovered in a cave system and may be yet another endemic element in the fauna of Vietnam. Some taxonomic propositions on the generic position of Scorpiops oligotrichus Fage, 1933 are also suggested.

  11. Changes in contraceptive use in Vietnam.

    Science.gov (United States)

    Thang, Nguyen Minh; Huong, Vu Thu

    2003-10-01

    This analysis used data, primarily from the 1997 Vietnamese Demographic and Health Survey (VN-DHS 1997), to determine the changes in contraceptive use in Vietnam. A descriptive analysis of individual, household and community characteristics was made to obtain a general description of contraceptive use. Multinomial logistic regression analyses were also performed on the currently married in (a) a sample of all women and (b) only those women who live in rural areas, to identify the strength of association that each variable has with the use of modern contraceptives. The use of any contraceptive method and the use of modern methods increased from 1988 to 1997. The primary contraceptive method utilized is the IUD and its use has increased substantially from 1988 to 1997. Younger women (aged 15-24) were less likely to use any contraceptive method. Women not desiring additional children were significantly more likely to use contraceptive methods than those desiring more children. Education has a clear impact on both contraceptive knowledge and use by women, with higher educated women being more likely to use a contraceptive method. Illiterate women with no formal education were significantly less likely to use modern methods of contraception. Differentials in contraceptive use exist regarding place of residence. Urban women are more likely than rural women to use contraception, but the difference is not large. Women living in mountainous areas are less likely to use contraception, compared with women living in the lowlands. Living standards, especially the availability of electricity in the community, have a large effect on the methods of contraception adopted by women. Religion is not strongly related to the contraceptive behaviour of women. There were significant differences in the use of contraceptives in communities with good quality of care, with increased contraceptive use corresponding to the increase in availability of family planning workers at communes

  12. Monitoring rice farming activities in the Mekong Delta region

    Science.gov (United States)

    Nguyen, S. T.; Chen, C. F.; Chen, C. R.; Chiang, S. H.; Chang, L. Y.; Khin, L. V.

    2015-12-01

    Half of the world's population depends on rice for survival. Rice agriculture thus plays an important role in the developing world's economy. Vietnam is one of the largest rice producers and suppliers on earth and more than 80% of the exported rice was produced from the Mekong Delta region, which is situated in the southwestern Vietnam and encompasses approximately 40,000 km2. Changes in climate conditions could likely trigger the increase of insect populations and rice diseases, causing the potential loss of rice yields. Monitoring rice-farming activities through crop phenology detection can provide policymakers with timely strategies to mitigate possible impacts on the potential yield as well as rice grain exports to ensure food security for the region. The main objective of this study is to develop a logistic-based algorithm to investigate rice sowing and harvesting activities from the multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS)-Landsat fusion data. We processed the data for two main cropping seasons (i.e., winter-spring and summer-autumn seasons) through a three-step procedure: (1) MODIS-Landsat data fusion, (2) construction of the time-series enhanced vegetation index 2 (EVI2) data, (3) rice crop phenology detection. The EVI2 data derived from the fusion results between MODIS and Landsat data were compared with that of Landsat data indicated close correlation between the two datasets (R2 = 0.93). The time-series EVI2 data were processed using the double logistic method to detect the progress of sowing and harvesting activities in the region. The comparisons between the estimated sowing and harvesting dates and the field survey data revealed the root mean squared error (RMSE) values of 8.4 and 5.5 days for the winter-spring crop and 9.4 and 12.8 days for the summer-autumn crop, respectively. This study demonstrates the effectiveness of the double logistic-based algorithm for rice crop monitoring from temporal MODIS-Landsat fusion data

  13. What's on the Surface? Physics and Chemistry of Delta-Doped Surfaces

    Science.gov (United States)

    Hoenk, Michael

    2011-01-01

    Outline of presentation: 1. Detector surfaces and the problem of stability 2. Delta-doped detectors 3. Physics of Delta-doped Silicon 4. Chemistry of the Si-SiO2 Interface 5. Physics and Chemistry of Delta-doped Surfaces a. Compensation b. Inversion c. Quantum exclusion. Conclusions: 1. Quantum confinement of electrons and holes dominates the behavior of delta-doped surfaces. 2. Stability of delta-doped detectors: Delta-layer creates an approx 1 eV tunnel barrier between bulk and surface. 3. At high surface charge densities, Tamm-Shockley states form at the surface. 4. Surface passivation by quantum exclusion: Near-surface delta-layer suppresses T-S trapping of minority carriers. 5. The Si-SiO2 interface compensates the surface 6. For delta-layers at intermediate depth, surface inversion layer forms 7. Density of Si-SiO2 interface charge can be extremely high (>10(exp 14)/sq cm)

  14. Structural transformation, biased technological change, and employment in Vietnam

    DEFF Research Database (Denmark)

    Abbott, Philip; Tarp, Finn; Wu, Ce

    Employment in Vietnam and elsewhere in Asia has grown more slowly than GDP over the last several decades. This means GDP per capita is rising. Vietnamese policymakers, however, are concerned that ongoing structural transformation is creating too few jobs. We use data for seven aggregated sectors ...

  15. Blacks in Vietnam; A Holistic Perspective Through Fiction and Journalism.

    Science.gov (United States)

    Harris, Norman

    1986-01-01

    Examining Afro-Americans in Vietnam in three novels reveals three components of their war experience: (1) a positive opportunity to prove fighting skills; (2) disillusionment when treated discriminatorily by white commanding officers; and (3) a cultural-historical search to make sense of their involvement in the war. (LHW)

  16. Traditional medicinal plants in Ben En National Park, Vietnam

    NARCIS (Netherlands)

    Van Sam, Hoang; Baas, P.; Keßler, P.J.A.

    2008-01-01

    This paper surveys the medicinal plants and their traditional use by local people in Ben En National Park, Vietnam. A total of 230 medicinal plant species (belonging to 200 genera and 84 families) is used by local people for treatment of 68 different diseases. These include species that are collecte

  17. Student Plagiarism in Higher Education in Vietnam: An Empirical Study

    Science.gov (United States)

    Do Ba, Khang; Do Ba, Khai; Lam, Quoc Dung; Le, Dao Thanh Binh An; Nguyen, Phuong Lien; Nguyen, Phuong Quynh; Pham, Quoc Loc

    2017-01-01

    This paper assesses and compares the prevalence of plagiarism across different student and assignment characteristics at a university in Vietnam, using the similarity index reported by the text-matching software Turnitin as a proxy measure of plagiarism on a sample of 681 student papers. The findings present a level of match higher than reported…

  18. After Access: Divergent Learning Profiles in Vietnam and India

    Science.gov (United States)

    Rolleston, Caine; James, Zoe

    2015-01-01

    In recent decades, both India and Vietnam have successfully expanded access to schooling to near-universal levels and have shifted their focus to quality-oriented policy reform. Yet, international and national evidence shows strongly contrasting learning profiles for children within the two systems. Simple indicators of numeracy suggest similar…

  19. Review of Power System Expansion Planning in Vietnam

    OpenAIRE

    Pereira, Mario

    2008-01-01

    This report assesses current energy expansion planning practices in Vietnam. This assessment comprises both technical aspects (methodology, planning criteria, construction of scenarios, sensitivity analysis and others) and evaluation of recent planning studies. In addition to an assessment of planning practices, it includes proposing a number of scenarios for the local consultant to carry ...

  20. An Empirical Analysis of Primary Teacher Standards in Vietnam

    Science.gov (United States)

    Griffin, Patrick; Cuc, Nguyen Thi Kim; Gillis, Shelley; Thanh, Mai Thi

    2006-01-01

    This article presents an account of the development of competency standards and profiles for primary teachers in Vietnam. The development project has taken more than four years and used a combination of consultative, actuarial, and item response modeling procedures to develop and validate a scale of teacher competence. In the overall project, more…