315 research outputs found
CENPHER five year report 2009-2014: From a research project to a research center
Beginning in 2009 with a postdoc project working on environmental sanitation and health issues, the Hanoi School of Public Health (HSPH) research group gradually established other projects and activities that have been both nationally and internationally funded. This was the basis for the upgrade of the research group to a research center in 2012, Public Health and Ecosystem Research (CENPHER). The creation and the development of CENPHER reflects not only North- South partnership in research and public health action, but also how great issues in national public health and global health can be tackled through ecosystems/ecohealth approaches
EVALUATING FUTURE WATER QUALITY OF URBAN RIVERS IN HANOI UNDER EFFECT OF URBANIZATION AND CLIMATE CHANGE - THE APPLICATION OF WEAP MODEL FOR CAU BAY RIVER
Every day, up to 750,000 cubic meters of wastewater in Hanoi metropolitan areas is discharged directly into rivers and lake, of which only 10% is treated to the Vietnamese standards. According to the water drainage development master plan for the capital city of Hanoi until 2030, the government aim at dealing with flooding and improve environmental sanitation for local residents. With respect to the baseline and Master plan implementation scenarios, this study evaluates the future water quality of urban rivers in Hanoi under the effect of urbanization and climate change using Water Evaluation And Planning tool (WEAP) and take the Cau Bay catchment as the case study. The result shows that, without implementation of wastewater treatment plant, the water quality of Cau Bay River will be worse with the DO in dry season is 0.2-1.2 mg/l and BOD is 52.0-55.0 mg/l. With the implementation of Master plan, the level of DO and BOD would be 7.1-7.3 mg/l and 7.0-13.8 mg/l respectively in the dry season whereas the values are 3.7 mgO/l and 36.1-41.8 mg/l in the wet season. The degradation of wastewater during the wet season is results from the combine- overflow sewage system as designed in the master plan
Performance Investigation of High-Speed Train OFDM Systems under the Geometry-Based Channel Model
The high-speed of train (HST) in combination with the high carrier frequency of HST systems leads to the severe inter carrier interference (ICI) in the HST orthogonal frequency division multiplexing (HST-OFDM) systems. To avoid the complexity in OFDM receiver design for ICI eliminations, the OFDM system parameters such as symbol duration, signal bandwidth, and the number of subcarriers should be chosen appropriately. This paper aims to propose a process of HST-OFDM system performance investigation to determine these parameters in order to enhance spectral efficiency and meet a given quality-of-service (QoS) level. The signal-to-interference-plus-noise ratio (SINR) has been used as a figure of merit to analyze the system performance instead of signal-to-noise ratio (SNR) as most of recent research studies. Firstly, using the non-stationary geometry-based stochastic HST channel model, the SINR of each subcarrier has been derived for different speeds of the train, signal bandwidths, and number of subcarriers. Consequently, the system capacity has been formulated as the sum of all the single channel capacity from each sub-carrier. The constraints on designing HST-OFDM system parameters have been thoughtfully analyzed using the obtained expressions of SINR and capacity. Finally, by analyzing the numerical results, the system parameters can be found for the design of HST-OFDM systems under different speeds of train. The proposed process can be used to provide hints to predict performance of HST communication systems before doing further high cost implementations as hardware designs
Do Parents Choose the Sex of their Children? Evidence from Vietnam
The paper finds imbalance of sex ratio at birth and analyzes some possible determinants on sex ratio at birth in Viet Nam by using the Vietnam Population Census 2009. This paper concentrates to analyze the parental interference of child sex. Although the magnitude of correlation between the parental characteristics and the gender of children is not high, this correlation is statistically significant. The result of this paper concludes that gender of the firstborn, birth order, ethnicity of parents, the age of parents as well as their education level are associated with the sex of children. More specifically, having the firstborn boy reduces the probability of having boys in the next birth. Children with higher birth order are more likely to be male. It implies that parents follow male-preferring stopping rule. Several households are more likely to have children until they get a boy. Kinh parents with higher education are more likely to have boys than ethnic minority parents with lower education
Do Parents Choose the Sex of their Children? Evidence from Vietnam
The paper finds imbalance of sex ratio at birth and analyzes some possible determinants on sex ratio at birth in Viet Nam by using the Vietnam Population Census 2009. This paper concentrates to analyze the parental interference of child sex. Although the magnitude of correlation between the parental characteristics and the gender of children is not high, this correlation is statistically significant. The result of this paper concludes that gender of the firstborn, birth order, ethnicity of parents, the age of parents as well as their education level are associated with the sex of children. More specifically, having the firstborn boy reduces the probability of having boys in the next birth. Children with higher birth order are more likely to be male. It implies that parents follow male-preferring stopping rule. Several households are more likely to have children until they get a boy. Kinh parents with higher education are more likely to have boys than ethnic minority parents with lower education
Status of acute hepatopancreatic necrosis disease (AHPND) and other emerging diseases of penaeid shrimps in Viet Nam
Acute hepatopancreatic necrosis disease (AHPND), formerly called early mortality syndrome (EMS), was first reported in 2010 among penaeid shrimps cultivated in the Mekong Delta Region of Viet Nam albeit without any laboratory confirmation. The disease subsequently spread to a wide range of shrimp production areas in the same region (Soc Trang: 1,719 ha; Bac Lieu: 346 ha; and Ca Mau: 3,493 ha), so that the Government of Viet Nam requested for technical assistance from the Food and Agriculture Organization (FAO) of the United Nations in 2011. In 2012, FAO supported Viet Nam through the project TCP/VIE/3304 Emergency assistance to control the spread of an unknown disease affecting shrimps in Viet Nam, under which the Department of Animal Health of Viet Nam (DAH) collaborated with the University of Arizona and FAO experts to carry out indepth studies to identify the etiologic agent of the disease. As a result, unique isolates of Vibrio parahaemolyticus was identified as the causative agent of AHPND in 2013. Viet Nam has been vigilant and transparent with regard to aquatic animal diseases through official notifications to the World Organization for Animal Health (OIE) and the Network of Aquaculture Centres in Asia-Pacific (NACA). AHPND outbreaks have no clear temporal pattern with black tiger (Penaeus monodon) and whiteleg (P. vannamei) shrimps showing similar incidence risk. The disease occurs at any stage of shrimp cultivation, i.e. on average about 35 days after stocking. To date, unwarranted outbreaks of AHPND in major shrimp-producing provinces in Viet Nam have been apparently regulated. Aside from AHPND, white spot disease (WSD) has also been a persistent problem responsible for serious economic losses in many shrimp-producing areas in Viet Nam. To prevent and control the further spread of infectious diseases of shrimps including AHPND and WSD, multiple control measures have been implemented including guidance of farmers to improve production conditions, facilities and biosecurity application, active surveillance of shrimp production areas for early warning, screening of broodstock and postlarvae for any OIE listed diseases, regulation on movement of stocks, and collaboration with regional and international organizations in carrying out in-depth epidemiological studies that will be needed in the formulation of pragmatic and holistic disease interventions
A PORTABLE CAPILLARY ELECTROPHORESIS SYSTEM FOR INORGANIC ARSENIC DETERMINATION
Joint Research on Environmental Science and Technology for the Eart
Assesment of antidermatophyte activity of oil from Curcuma longa L. in vitro
Curcuma longa L. is a rhizomatous herbaceous perennial plant, and its essential oil showed antifungal, antibacterial, antioxydant, antivenom, and antitumor effects. The antidermatophytes of oil from turmeric was demonstrated. This study was carried out in order to evaluate inhibition activity of oil from Vietnamese turmeric against two strains dermatophyte, Trychophytol mentargrohytes and Candida albicans. The oil from Vietnamese turmeric was obtained by hydrodistillation method and its chemical composition was determined by GC/MS. By comparing with authentic reference compounds in mass spectra library Nist 98.1 and Wiley 275.L, 13 compounds of oil from Vietnamese turmeric were identified. The received results showed that, the oil is rich in turmerones (about 44%), which has been recognized as major constituent attributing to antimicrobial activity. By disc diffusion method, the antifungal activity of the turmeric essential oil against T. mentargrophyte and C. albicans was demonstrated. The MICs of the turmeric oil for T. mentargrophytes và C. albicans were 0.5%. The minimal killing time for C. albicans was 60 minutes and for T. mentargrophyte was 90 minutes after treatment with the turmeric oil
Fostering innovative behavior in the aviation industry: The role of perceived supervisor support and work group diversity
The research primarily seeks to understand how supervisor support can directly and indirectly enhance the service innovative behavior (SIB) of flight attendants via work engagement. Moreover, although there has been some research on the effect of group diversity on organizational performance, the results have not been consistent. Thus, this study addresses this gap by investigating how work group diversity can make variance in the relationship between work engagement and innovative behavior of flight attendants. The sample size of 242 flight attendants working at the central airport in Ho Chi Minh City, Vietnam, has been taken for the study. To test hypotheses, structural equation modeling and bootstrapping were employed. This study provided an evidence for the positive nexus between perceived supervisor support and SIB. Additionally, the results shed light on a mediation mechanism of work engagement for the association between flight attendants' perception of their supervisor and innovative behavior. Furthermore, tenure diversity and job position diversity in a work group were proved to play a moderating role in the relationship between work engagement and service innovative behavior. Specifically, flight attendants are more willing to exhibit innovative behaviors when working in a homogeneous group in terms of tenure and job position rather than in a heterogeneous group. The empirical results contributed to the diversity management literature and broadened the understanding of how to activate the service innovative behavior of employees. From a managerial perspective, managers should pay attention to the characteristics of employees when organizing teamwork. © Long Nguyen Le Hoang, Huong Nguyen Thi Thu, Viet-Anh Ho, 202
Economic Inequality and Happiness: A quantitative study among the elderly in Rural Vietnam
By combining data from the 2011 Vietnam National Aging Survey and the 2011 Rural, Agricultural and Fishery Census, we examined whether expenditure inequality has any effect on happiness or life satisfaction among the elderly in rural Vietnam. We find that individuals who live in the communes with high inequality tend to self-report as being less happy, even after controlling for various individual and household attributes. The results are robust to the choice of inequality measures and the specification of econometric models. We also find that older rural people who are farmers or poor are more sensitive to inequality. Given that these people tend to be less happy than others, the result shows the risk that inequality further lowers their subjective well-being. The result supports the view that rural Vietnam is a less mobile society
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