Sites In Vietnam Research Articles

A new species of Fansipaniana from Northern Vietnam (Lepidoptera: Tortricidae: Olethreutinae: Olethreutini).

Vietnam micro-moths remain poorly known, and new species are discovered year after year among the Tortricidae (Kuznetzov 1992, 2000; Razowski 2003, 2008; Heppner 2010; Heppner and Bae 2015a, b) and other families (e.g., Park et al. 2007). Razowski (2009) described the genus Fansipaniana for a single new species from the high mountains in northern Vietnam close to the border with China. Recent exploration of many areas in Vietnam has resulted in the discovery of a second species of Fansipan-iana from a lower elevation mountain range near Hanoi. The new species is from Tam Dao, one of the most well known sites in Vietnam for moth collecting.

Halogenated Polycyclic Aromatic Hydrocarbons in Soil and River Sediment from E-waste Recycling Sites in Vietnam

Halogenated Polycyclic Aromatic Hydrocarbons in Soil and River Sediment from E-waste Recycling Sites in Vietnam

Occurrence of emerging flame retardants from e-waste recycling activities in the northern part of Vietnam

Abstract This study investigated the contamination status of 21 emerging flame retardants (FRs) in soils (n = 32) and river sediments (n = 8) from an e-waste recycling (EWR) site in the northern part of Vietnam. Among analyzed FRs, higher levels of decabromodiphenyl ethane (DBDPE) (ND–4200 ng/g dw), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) (ND–350 ng/g dw) and Dechlorane Plus isomers (DPs) (ND–65 ng/g dw) were found in soils near EWR workshops and open burning places. The highest concentrations of DBDPE (20 ng/g dw), BTBPE (5.7 ng/g dw) and DPs (6.7 ng/g dw) were also detected in sediments collected from the middle of the EWR site. The levels decreased concomitantly with increasing distance from the EWR site. These results indicate that these FRs were released to the surrounding environment from improper recycling activities, such as manual dismantling of devices and open burning of e-wastes. Moreover, the estimated daily intakes of those FRs via soil ingestion were approximately ten times higher for children than adults. To our knowledge, this is a first comprehensive study on characterization of soil and sediment contamination by a series of emerging FRs at an EWR site in Vietnam.

Chronic diseases among the elderly in a rural Vietnam: prevalence, associated socio-demographic factors and healthcare expenditures

BackgroundGlobally, the population of elderly persons is increasing as well as the prevalence of chronic diseases. This change is causing increased healthcare costs to health care systems threatening to push many households into poverty. Low and middle income countries are projected to experience the greatest impact from this change. This study aims to describe the prevalence of common chronic diseases (CCDs) among the elderly in Vietnam, the associated socio-demographic factors and healthcare expenditures.MethodsThis is a cross-sectional study in the FilaBavi demographic surveillance site in Vietnam. 2873 persons over 60 years were randomly sampled. Prevalence of CCDs was reported from study subjects who previously were informed by physicians. Healthcare expenditures were determined from recall of expenses during the last hospital visit. Binomial logistic regression was done to determine the socio demographic predictors of having a CCD or multiple CCDs. Mean healthcare expenditures for the elderly with CCDs and those without CCDs were summarised and compared.ResultsForty two percent of the elderly were found to have at least one CCD. Joint problems were the most common CCD at 35 %, followed by hypertension at 15 % and chronic bronchitis at 11 %. Being female (OR = 1.51, 95 % CI = 1.03–2.21, p-value = 0.036), higher education (OR = 2.54, 95 % CI = 1.13–5.74, p-value = 0.025) and having advanced age (OR = 1.92, 95 % CI = 1.22–3.00, p-value = 0.005), were associated with common chronic diseases in the elderly. Outpatient healthcare expenditures were found to be significantly higher for the elderly with CCDs than those without CCDs.ConclusionsHigher education and being female are important key predictors of having a CCD, while wealth quintile is a predictor of multimorbidity, in the elderly. Healthcare expenditures for outpatient health services are higher for elderly persons with CCDs and these costs should be targeted when planning for financial protection.

Sustained impacts of Kaizen training

We conducted a randomized controlled trial of short-term management training for small manufacturers in two study sites in Vietnam and collected follow-up data repeatedly for two years to assess longer-term impacts than the existing studies of management training. Our training programs introduced participants to Kaizen, a common-sense approach to production management. In both sites, many participants started to recognize the importance of learning about management and improved their management skills. The impacts on management skills were statistically significant two years after the programs. Our results suggest that the training program increased participants’ value added in one of the two study sites, likely because they learned how to eliminate wastes in production.

Biogeographic distribution and metric dental variation of fossil and living orangutans (Pongo spp.).

The genus Pongo has a relatively richer Quaternary fossil record than those of the African great apes. Fossil materials are patchy in terms of anatomical parts represented, limited almost exclusively to isolated teeth, jaw and bone fragments. Fossil evidence indicates that the genus Pongo had a broadly continuous distribution across the southern part of the Indomalayan biogeographic region, ranging in time from Early Pleistocene to Holocene: southern China (77 fossil sites), Vietnam (15), Laos (6), Cambodia (2), Thailand (4), Peninsular Malaysia (6), Sumatra (4), Borneo (6) and Java (4). Within this distribution range, there are major geographical gaps with no known orangutan fossils, notably central and southern Indochina, central and southern Thailand, eastern Peninsular Malaysia, northern and southern Sumatra, and Kalimantan. The geological time and place of origin of the genus remain unresolved. Fossil orangutan assemblages usually show greater extent of dental metrical variation than those of modern-day populations. Such variability shown in prehistoric populations has partially contributed to confusion regarding past taxonomic diversity and systematic relationships among extinct and living forms. To date, no fewer than 14 distinct taxa have been identified and named for Pleistocene orangutans. Clear cases suggestive of predation by prehistoric human are few in number, and limited to terminal Pleistocene-Early Holocene sites in Borneo and a Late Pleistocene site in Vietnam.

Tourist Satisfaction and Destination Image of Vietnam's Ha Long Bay

Although considerable work has been done on destination image as a whole, far less research has investigated the differences in destination image assessments for domestic versus international visitors in developing countries. This study offers findings that illustrate the differences in perception of destination image, satisfaction attributes, and intention among domestic and international visitors to Ha Long Bay, a United Nations Educational Scientific and Cultural Organization World Heritage Site in Vietnam. The results of a survey on 650 tourists suggest that international visitors to the Ha Long Bay region have higher standards and are more critical in their evaluation of services than domestic visitors when judging this destination. Destination image is a common factor determining the level of satisfaction of both groups. Basic and augmented services were found to influence international visitors’ future intention toward the destination. This finding implies that the destination managers of Ha Long Bay need to improve current standard of augmented services to yield higher visitors’ propensity to recommend and return to the destination.

Sequential anaerobic–aerobic biodegradation of 2,3,7,8-TCDD contaminated soil in the presence of CMC-coated nZVI and surfactant

Enriched microorganisms in sediment collected from a dioxin-contaminated site in Vietnam (Bien Hoa airbase) were used for examining the effectiveness in biological treatment of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in soil. Four bio-treatments were investigated using a sequential anaerobic (17 weeks) followed by an aerobic (6 weeks) incubation. The maximum removal efficiency was approximately 60% even at an extremely low pH (approx. 3.6) condition. Surfactant Tween-80 was added to enhance the bioavailability of dioxin in two treatments, but it appeared to biostimulate methanogens rather than dechlorinators. As a result, methane production was the highest while the dioxin removal efficiency was the lowest, as compared with the other bio-treatments. Carboxymethylcellulose (CMC) coated on nanoscale zero valent iron (nZVI) surface used in two treatments could prevent the direct contact between bacterial cell surface and nZVI which prevented cell death and lysis, hence enhancing dioxin removal. The presence of CMC­­_nZVI in bio-treatments gradually released H2 required for microbiological processes, but the amount used in the experiments were likely too high to maintain optimum H2 levels for biostimulating dechlorinators rather than methanogens.

Genetic variation in growth, stem straightness, pilodyn and dynamic modulus of elasticity in second-generation progeny tests of Acacia mangium at three sites in Vietnam

164 open-pollinated families of Acacia mangium from six different genetic groups were tested in three second-generation progeny tests planted at Tuyen Quang and Ba Vi in northern Vietnam and Bau Bang in the south. All trees were measured to estimate individual heritabilities and genetic correlations for growth traits, stem straightness and pilodyn in the three trials, and dynamic modulus of elasticity (MoEd) of standing trees was only assessed in Tuyen Quang. There were significant differences between families for growth traits, stem straightness, pilodyn penetration and predicted MoEd. Heritabilities of growth traits, stem straightness, pilodyn and dynamic modulus of elasticity were low to moderate (h2 = 0.11–0.30). The coefficient of additive genetic variation for DBH, pilodyn and MoEd were moderate at age 3 or 4 years (CVa = 4.9–9.4 %). Genetic correlations between stem straightness, pilodyn and growth traits were favourable but weak, while those between growth traits and dynamic modulus of elasticity were weak and unfavourable. The substantial coefficients of additive genetic variation and significant heritabilities for all traits indicate that it should be possible to use a selection strategy that combines improvements in growth, stem straightness, and wood quality for A. mangium in Vietnam. The site–site genetic correlations between the two northern trials and Bau Bang site were low for growth traits, indicating that G × E effects are of practical importance for growth and different deployment populations will be required for different sites.

Solar resources and power potential mapping in Vietnam using satellite-derived and GIS-based information

The present paper presents maps of the solar resources in Vietnam and of the solar potential for concentrating solar power (CSP) and for grid-connected photovoltaic (PV) technology. The mapping of solar radiation components has been calculated from satellite-derived data combined with solar radiation derived from sunshine duration and other additional sources of information based on reanalysis for several atmospheric and meteorological parameters involved. Two scenarios have been selected for the study of the solar potential: CSP Parabolic Trough of 50MWe and grid-connected Flat Plate PV plant of around 1MWe. For each selected scenario plant performance simulations have been computed for developing simple expressions that allow the estimation of the solar potential from the annual solar irradiation and the latitude of every site in Vietnam. Finally, Geographic Information Systems (GIS) have been used for combining the solar potential with the land availability according each scenario to deliver the technical solar potential maps of Vietnam.

ONLINE GROUP BUYING: AN INVESTIGATION ON SERVICE QUALITY AND CUSTOMER SATISFACTION IN VIETNAM

ABSTRACT Online group buying has been gaining momentum in Vietnam as a type of online shopping. We develop a causal model to identify determinants to the level of satisfaction with online group buying sites in Vietnam. Adapting scales tested in the previous research on service quality of websites, we measure Vietnamese customers’ perception on efficiency, fulfillment, system availability, privacy, responsiveness, and contact along with price discount, trust, and salience of brand of group buying websites. We find that those websites are low in privacy, trust, and responsiveness. Although online service quality as a whole is a critical factor to customer satisfaction, there is uniqueness in the relation between service quality and customer satisfaction in Vietnamese group buying services. That is, responsiveness and privacy have no significant relationships with satisfaction; contact and fulfillment have the largest impacts. The empirical results suggest that there is a variety of ways for Vietnamese group buying sites to differentiate themselves and enhance customers’ perception on service quality. Keywords customer satisfaction, group buying websites, marketing, online service quality, Vietnam.

Mitochondrial genetic differentiation and morphological difference of Miniopterus fuliginosus and Miniopterus magnater in China and Vietnam.

Because of its complicated systematics, the bent-winged bat is one of the most frequently studied bat species groups. In China, two morphologically similar bent-winged bat species, Miniopterus fuliginosus and Miniopterus magnater were identified, but their distribution range and genetic differentiation are largely unexplored. In this study, we applied DNA bar codes and two other mitochondrial DNA genes including morphological parameters to determine the phylogeny, genetic differentiation, spatial distribution, and morphological difference of the M. fuliginosus and M. magnater sampled from China and one site in Vietnam. Mitochondrial DNA gene genealogies revealed two monophyletic lineages throughout the Tropic of Cancer. According to DNA bar code divergences, one is M. fuliginosus corresponding to the Chinese mainland and the other is M. magnater corresponding to tropical regions including Hainan and Guangdong provinces of China and Vietnam. Their most recent common ancestor was dated to the early stage of the Quaternary glacial period (ca. 2.26 million years ago [Ma] on the basis of D-loop data, and ca. 1.69–2.37 Ma according to ND2). A population expansion event was inferred for populations of M. fuliginosus at 0.14 Ma. The two species probably arose in separate Pleistocene refugia under different climate zones. They significantly differed in forearm length, maxillary third molar width, and greatest length of the skull.

Cause-specific childhood mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites

Background Childhood mortality, particularly in the first 5 years of life, is a major global concern and the target of Millennium Development Goal 4. Although the majority of childhood deaths occur in Africa and Asia, these are also the regions where such deaths are least likely to be registered. The INDEPTH Network works to alleviate this problem by collating detailed individual data from defined Health and Demographic Surveillance sites. By registering deaths and carrying out verbal autopsies to determine cause of death across many such sites, using standardised methods, the Network seeks to generate population-based mortality statistics that are not otherwise available. Objective To present a description of cause-specific mortality rates and fractions over the first 15 years of life as documented by INDEPTH Network sites in sub-Saharan Africa and south-east Asia. Design All childhood deaths at INDEPTH sites are routinely registered and followed up with verbal autopsy (VA) interviews. For this study, VA archives were transformed into the WHO 2012 VA standard format and processed using the InterVA-4 model to assign cause of death. Routine surveillance data also provided person-time denominators for mortality rates. Cause-specific mortality rates and cause-specific mortality fractions are presented according to WHO 2012 VA cause groups for neonatal, infant, 1–4 year and 5–14 year age groups. Results A total of 28,751 childhood deaths were documented during 4,387,824 person-years over 18 sites. Infant mortality ranged from 11 to 78 per 1,000 live births, with under-5 mortality from 15 to 152 per 1,000 live births. Sites in Vietnam and Kenya accounted for the lowest and highest mortality rates reported. Conclusions Many children continue to die from relatively preventable causes, particularly in areas with high rates of malaria and HIV/AIDS. Neonatal mortality persists at relatively high, and perhaps sometimes under-documented, rates. External causes of death are a significant childhood problem in some settings.

Estimates of genetic parameters for growth and wood properties in Eucalyptus pellita F. Muell. to support tree breeding in Vietnam

Eucalyptus pellita demonstrated good growth and wood quality traits in this study, with young plantation grown timber being suitable for both solid and pulp wood products. All traits examined were under moderate levels of genetic control with little genotype by environment interaction when grown on two contrasting sites in Vietnam. Eucalyptus pellita currently has a significant role in reforestation in the tropics. Research to support expanded of use of this species is needed: particularly, research to better understand the genetic control of key traits will facilitate the development of genetically improved planting stock. This study aimed to provide estimates of the heritability of diameter at breast height over bark, wood basic density, Kraft pulp yield, modulus of elasticity and microfibril angle, and the genetic correlations among these traits, and understand the importance of genotype by environment interactions in Vietnam. Data for diameter and wood properties were collected from two 10-year-old, open-pollinated progeny trials of E. pellita in Vietnam that evaluated 104 families from six native range and three orchard sources. Wood properties were estimated from wood samples using near-infrared (NIR) spectroscopy. Data were analysed using mixed linear models to estimate genetic parameters (heritability, proportion of variance between seed sources and genetic correlations). Variation among the nine sources was small compared to additive variance. Narrow-sense heritability and genetic correlation estimates indicated that simultaneous improvements in most traits could be achieved from selection among and within families as the genetic correlations among traits were either favourable or close to zero. Type B genetic correlations approached one for all traits suggesting that genotype by environment interactions were of little importance. These results support a breeding strategy utilizing a single breeding population advanced by selecting the best individuals across all seed sources. Both growth and wood properties have been evaluated. Multi-trait selection for growth and wood property traits will lead to more productive populations of E. pellita both with improved productivity and improved timber and pulp properties.

Occurrence of Perchlorate and Thiocyanate in Human Serum From E-Waste Recycling and Reference Sites in Vietnam: Association With Thyroid Hormone and Iodide Levels

Perchlorate (ClO4 (-)) and thiocyanate (SCN(-))interfere with iodide (I(-)) uptake by the sodium/iodide symporter, and thereby these anions may affect the production of thyroid hormones (THs) in the thyroid gland. Although human exposure to perchlorate and thiocyanate has been studied in the United States and Europe, few investigations have been performed in Asian countries. In this study, we determined concentrations of perchlorate, thiocyanate, and iodide in 131 serum samples collected from 2 locations in Northern Vietnam, Bui Dau (BD; electrical and electronic waste [e-waste] recycling site) and Doung Quang (DQ; rural site) and examined the association between serum levels of these anions with levels of THs. The median concentrations of perchlorate, thiocyanate, and iodide detected in the serum of Vietnamese subjects were 0.104, 2020, and 3.11ngmL(-1), respectively. Perchlorate levels were significantly greater in serum of the BD population (median 0.116ngmL(-1)) than those in the DQ population (median 0.086ngmL(-1)), which indicated greater exposure from e-waste recycling operations by the former. Serum concentrations of thiocyanate were not significantly different between the BD and DQ populations, but increased levels of this anion were observed among smokers. Iodide was a significant positive predictor of serum levels of FT3 and TT3 and a significant negative predictor of thyroid-stimulating hormone in males. When the association between serum levels of perchlorate or thiocyanate and THs was assessed using a stepwise multiple linear regression model, no significant correlations were found. In addition to greater concentrations of perchlorate detected in the e-waste recycling population, however, given that lower concentrations of iodide were observed in the serum of Vietnamese females, detailed risk assessments on TH homeostasis for females inhabiting e-waste recycling sites, especially for pregnant women and their neonates, are required.

Buccal misoprostol for treatment of fetal death at 14–28 weeks of pregnancy: a double-blind randomized controlled trial

ObjectiveTo assess whether buccal misoprostol is effective for the treatment of intrauterine fetal death. Study DesignThis double-blind randomized trial was conducted at five tertiary-level hospitals in the United States and Vietnam. One hundred fifty-three women with an intrauterine fetal death at 14–28 weeks of pregnancy received either 100 mcg buccal misoprostol or 200 mcg buccal misoprostol every 6 h for a maximum of 8 doses. The main outcome measure was the fetal-placental delivery rate within 48 hours of prostaglandin commencement without any additional intervention. ResultsMost of the women (140/153) were recruited at the study site in Vietnam. Expulsion of both fetus and placenta within 48 hours of prostaglandin commencement without any additional interventions occurred in 61.8% (47/76) of women receiving misoprostol 100 mcg and 77.9% (60/77) of women receiving misoprostol 200 mcg. The 200 mcg dose was significantly more effective than the 100 mcg dose at expelling the fetus and placenta within 48 h [RR 0.68 (95% CI: 0.50–0.92; p=.03)]. The mean time to expulsion was significantly shorter using the 200 mcg dose (18.5±11.9 h) than the 100 mcg dose (23.9±12.5 h) (p=.02). Most women in both groups found the procedure satisfactory or very satisfactory (100 mcg: 76.7% (56/73); 200 mcg: 89.5% (68/76) [RR 0.86 (95% CI: 0.74–1.00)]. ConclusionBuccal misoprostol is an effective method for medical induction of labor after intrauterine fetal demise. A 200 mcg dose is significantly more effective than 100 mcg for evacuating the uterus within 48h. The treatment is highly acceptable to women. ImplicationsAdministration of 200 mcg buccal misoprostol every six hours is an effective and acceptable method to effect the delivery of a demised fetus at 14–28 weeks that can be feasibly implemented in a wide variety of settings.

Lasting Monuments and Durable Institutions: Labor, Urbanism, and Statehood in Northern Vietnam and Beyond

Archaeological research on monumentality, early urbanism, and emergent statehood in Southeast Asia and Vietnam has grown dramatically in recent years, and our understanding of social evolution in Southeast Asia has moved beyond traditional models of Sinicization and Indianization. Although many researchers recognize the significance of the historic and classical states of the first and second millennia AD, the seeds of statehood and urbanism can be seen in a moated settlement pattern during the first millennium BC. The largest in this category of Iron Age settlements, the heavily fortified Co Loa site in Vietnam’s Red River Valley, is emblematic of a tradition of settlements marked by earthworks and moat systems. The scale and extent of Co Loa’s massive earthen rampart system, involving a complex construction enterprise, reflect planning and implementation by a highly centralized, multigenerational, and institutionalized authority. Dating to the last centuries BC, Co Loa represents one of the earlier ancient state-level societies in Vietnam and the wider Southeast Asian region. Ultimately, the durability of Co Loa’s institutions of power and governance is suggested by the nature of its rampart system and construction process, and a package of variables contributed to emergent complexity. In particular, the presence of a monumental system of defensive works, combined with other archaeological markers for intraregional competition and violence, underscores the potential role of warfare and physical coercion in the course of political centralization.

The open-air site of Huai Hin (Northwestern Thailand): Chronological perspectives for the Hoabinhian

The Hoabinhian is well known in Southeast Asian prehistoric studies, where it has been considered both a chronological period and a cultural entity. However, recent work suggests it should more appropriately be considered a functional technocomplex. Although most often described from sites in Vietnam and Thailand, it has also been recognized in northern Sumatra and Cambodia. Here, we present a series of Hoabinhian stone tools discovered during fieldwork carried out by the Thai-French Paleosurvey at the Huai Hin site found on the eastern bank of the Salaween River near the Thai-Burmese border. Although the technological analysis of this material supplies new evidence for Hoabinhian regional variability, new dates from this open-air site also provide a useful reference point for constructing a regional chrono-cultural sequence for Southeast Asian prehistory.

Geogene Versus Anthropogene Origin of Trace Metals in Sediments in Cua Luc Estuary and Ha Long Bay, Vietnam

In the present study, the geochemistry of 49 surficial-bed and 101 core sediment samples is investigated to clarify the origin of trace metals in the Cua Luc Estuary and Ha Long Bay, which is a famous World Natural Heritage Site in Vietnam. Moreover, the potential mobility of trace metals is also assessed and their relationship with reference elements (Al, Fe, and Ca) and organic matter is established in order to make recommendations for sediment management and monitor future pollution. Generally, trace metals display higher concentrations in Ha Long Bay compared to the Cua Luc Estuary. However, this is controlled by the distribution of the fine (clay + silt) fraction, and hence the concentrations of Al, Fe, Ca, and organic matter (OM). The comparison of concentrations of trace metals (normalized towards Al) between the surficial sediments and the subsurface core sediments based on 137Cs datings indicates that almost all surficial-sediment data fall inside or deviate slightly from the 95 % prediction interval of a background regression line. In addition, as determined by a Community Bureau of Reference three-step extraction, trace metals mainly dominate in the residual fraction (assumed to relate to crystal lattice of primary and secondary minerals), and this fraction does not change much in recent sediment layers. Therefore, trace metals are supposed to be derived from natural bio/geochemical processes and are characterized by a low potential mobility. Consequently, the established linear regression relationships of trace metal vs. Al or multiple regression relationships of trace metal vs. multi-elements (Al, Fe, Ca, and OM) are useful for the prediction of background levels of trace metals in sediments in future pollution monitoring and assessment programs.

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

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; <1.4-100, <1.2-100, and <0.5-20 ng/L, respectively). Interestingly, there were specific PFC profiles: perfluoroheptanoic acid and perfluorohexanoic acid (88 and 77 ng/L, respectively) were almost as abundant as PFOA in MD leachate (100 ng/L), whereas PFNA was prevalent in ER and BR (mean, 17 and 6.2 ng/L, respectively) and PFUDA was the most abundant in municipal wastewater (mean, 5.6 ng/L), indicating differences in PFC contents in different waste materials.