Trends in overweight by socio-economic status in Vietnam: 1992 to 2002

OBJECTIVE: To explore socio-economic factors associated with rising rates of overweight among Vietnamese adults. DESIGN: The study was based on three national surveys of socio-economic factors and health conducted over a 10-year period. The studies were: the Vietnamese Living Standard Survey 1992-1993 (11 982 participants); the Vietnamese Living Standard Survey 1997-1998 (15 975 participants); and the Vietnamese National Health Survey 2001-2002 (94 656 participants). SUBJECTS: Male and female adults >18 years old were stratified by gender, age group, area of residence, occupation, education and relative food expenditures. Overweight was defined using body mass index (BMI) > or = 25 kg m(-2). RESULTS: Overweight rates in Vietnam more than doubled between 1992 and 2002 (from 2.0 to 5.7%). Significant increases were observed for men and women, in urban and rural areas, and for all age groups. In univariate analyses, both age and higher socio-economic status were associated with higher rates of overweight. Using the most recent survey, urban populations were more likely to be overweight than rural ones (odds ratio (OR) = 1.79), white-collar workers were more likely to be overweight than manual labourers (OR = 1.95) and persons in the top level of food expenditures were more likely to be overweight than persons in the bottom level (OR = 4.96) after adjustment for other factors. Education was inversely associated with overweight after adjusting for covariates. CONCLUSION: Economic growth and improved standard of living are associated with higher rates of overweight in nations in early stages of economic development. In Vietnam, higher rates of overweight were observed among the higher income and occupation groups.     

A xenia effect on number and volume of cotyledon cells and on seed weight in faba bean (Vicia faba L.)

The female line 1709, carrying the recessivecharacter green cotyledon, marker of the embryogenotype, was cross-pollinated by bees in the presenceof either male line HG115 or male line Dial63. In thecomparison of seeds which resulted either fromintercrossing or from selfing, a xenia effect wasobserved on volume and number of cotyledon cells andon individual seed weight which was dependent on themale line. The increase of hybrid seed weight inducedby the small-seeded male line Dial63 was larger thanthe one induced by the large-seeded male line HG115.The xenia effect on seed weight was correlated withthe level of heterosis in the F1 plant's growth.     

Main Characteristics of Statistical Data and the Statistical System for Wood and Wood-processing Products in Vietnam

This paper describes the characteristics of data about wood and wood-processing products published in Vietnam. The characteristics include inconsistency of data published by major data sources, lack of necessary data, and irregular publication frequency. Reasons are identified for the existence of the above characteristics of data for the wood and wood-processing industries, including recent changes in the functions of state statistical organizations and unclear concepts of data published. These characteristics create difficulties for researchers and policy-makers working at the Ministry of Agriculture and Rural Development for analysing policies and establishing supply targets for the wood and wood-processing industries in 5-year economic plans. To improve the statistical system, co-operation between state organisations and the information network (e.g. computers and internet connection) requires strengthening.     

How do earthworms influence organic matter quantity and quality in tropical soils?

Earthworms are important regulators of soil structure and soil organic matter (SOM) dynamics; however, quantifying their influence on SOM cycling in tropical ecosystems remains little studied. Simulated rainfall was used to disrupt casts produced by Amynthas khami and their surrounding soil (control) into a range of small sized aggregates (50-250, 250-500, 500-2000 and 2000-5000 μm). To gain insight into how earthworms influence SOM biogeochemical composition in the aggregates, we carried out elemental and stable isotope analysis, and analytical pyrolysis (Py GC/MS). We also characterized their lignin component after oxidation with cupric oxide (CuO).The C content of smaller size fractions (<500 μm) in the control soil was higher than in the larger fractions. Our study therefore suggests that the aggregate hierarchy concept, which is used to understand soil aggregates and SOM dynamics in temperate soils, may not be applicable to the tropical Acrisol studied here. Earthworms modified SOM organization in soil aggregates. Although the isotope analyses were useful for highlighting SOM enrichment in the earthworm casts, aggregate fractions could not be classified according to particle size. Molecular analyses were necessary to indicate that SOM in all size fractions of casts consisted of relatively undecomposed material. Protection of the most labile SOM structures occurred in the smallest aggregate size fraction (50-250 μm). Py GC/MS showed that earthworm casts and control aggregates <2000 μm could be clearly distinguished according to the molecular properties of their SOM. Aggregates larger than 2000 μm, however, were most probably composed of all fractions and were not different. As a consequence, our results indicate that studies to determine the impact of earthworms on SOM turnover in soil are spatially dependant on the scale of observation.     

Detection and molecular characterization of sugarcane grassy shoot phytoplasma in Vietnam

Sugarcane is an important cash crop in Vietnam and has been widely promoted at national and provincial level. In 2006, a new disease was discovered in sugarcane in the Nghean Tate&Lyle Sugar Mill in Nghean Province in north-central Vietnam. The key symptoms were the formation of green grassy shoots around the base of mature stools. We applied nested polymerase chain reaction (PCR) using P1/P7 and R16F2n/R16R2 for detection and characterization of phytoplasma from the symptomatic tissues. PCR products of the expected size (approx. 1200?bp) were obtained from the 16S rDNA of the phytoplasma. The restriction fragment length polymorphism profiles indicated that all samples were infected by the same phytoplasma. Phylogenetic analysis confirmed that the SCGS phytoplasma from Vietnam belong to the 16SrXI group, formerly Rice Yellow Dwarf group.     

Genetic studies on saline and sodic tolerances in soybean

Salt-affected soils are generally classified into two main categories: saline and sodic (alkaline). Developing and using soybean (Glycine max (L.) Merr) cultivars with high salt tolerance is an effective way of maintaining sustainable production in areas where soybean growth is threatened by salt stress. Early classical genetics studies revealed that saline tolerance was conditioned by a single dominant gene. Recently, a series of studies consistently revealed a major quantitative trait locus (QTL) for saline tolerance located on linkage group N (chromosome 3) around the SSR markers Satt255 and Sat_091; other minor QTLs were also reported. In the case of sodic tolerance, most studies focused on iron deficiency caused by a high soil pH, and several QTLs associated with iron deficiency were identified. A wild soybean (Glycine soja Sieb. & Zucc.) accession with high sodic tolerance was recently identified, and a significant QTL for sodic tolerance was detected on linkage group D2 (chromosome 17). These studies demonstrated that saline and sodic tolerances were controlled by different genes in soybean. DNA markers closely associated with these QTLs can be used for marker-assisted selection to pyramid tolerance genes in soybean for both saline and sodic stresses.     

Growth and wood basic density of acacia hybrid clones at three locations in Vietnam

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P < 0.001) differences in height and diameter at breast height (DBH) among 22 tested clones at 4 years. At Long Thanh, twelve hybrid clones did not differ significantly in DBH at age 3 years, but did (P < 0.001) at age 5 years. At the two northern sites the acacia hybrid clones had significantly greater DBH than control seedlots of the parental species. At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m⁻³ at Yen Thanh at age 8 years, and 473 kg m⁻³ at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m⁻³. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.     

High yield and nutritional quality of rice for animal feed achieved by continuous irrigation with treated municipal wastewater

Paddy and Water Environment - Two consecutive pilot-scale experiments were conducted to investigate the potential reuse of treated municipal wastewater (TWW) as an irrigation source for cultivating...