Rural Nonfarm Employment Under Trade Reform Evidence From Vietnam, 1993-2002

Vietnam?s rural economy has substantially diversified over the past two decades. The rural nonfarm sector has grown rapidly and became an important source of employment and income for rural households. This growing nonfarm employment was associated with radical changes in the trade policy reform that has put the country to the top two or three performers in the developing world. This paper examines the potential effect of the trade policy reform on nonfarm employment in rural Vietnam during the period 1993-2002. It proposes two trade openness indices that allow changes in the trade policy at the macro level to be transmitted to rural households. The results reveal that the trade policy reform does have a material impact on rural nonfarm employment. While a more liberalized agricultural sector encourages nonfarm diversification, a lower protection level in the nonfarm sector discourages individual participation in nonfarm income-generating activities.Trade liberalization, trade policy reform, rural nonfarm employment, Vietnam

An optimization and analysis framework for TCO minimization of plug-in hybrid heavy-duty electric vehicles

This paper develops an optimization framework to minimize the Total Cost of Ownership (TCO) for Plug-in Hybrid Electric Vehicles (PHEVs). In this paper, TCO is the summation of operational and main vehicle powertrain components cost. The developed optimization framework is formulated via combining convex optimization and Dynamic Programming technique. This framework aims at minimizing TCO by optimizing not only the sizing of the main powertrain components but also the powertrain topology. Using the developed optimization framework, this paper elaborates relevant design factors for a considered bus application namely: i) the value of equipping a HEV with plug-in functionality; ii) the effect of battery aging and replacement cost; iii) the sensitivity to fuel and electricity cost; Simulation results show that the TCO can be reduced by having plug-in functionality in the HEVs. However, this may not hold if the electricity price (in Euros/kWh) is higher than certain times of the fuel price (in Euros/kWh), e.g. 2.25 for the simulated cases in this paper. Simulation results also suggest that it is more profitable to equip the vehicle with a big enough battery to avoid replacing it during the vehicle economical life

Quantitative near-infrared spectroscopy of cervical dysplasia in vivo

The aims of this study were: (i) to quantify near-infrared optical properties of normal cervical tissues and high-grade squamous intra-epithelial lesions (H-SIL); (ii) to assess the feasibility of differentiating normal cervical tissues from H-SIL on the basis of these properties; and (iii) to determine how cervical tissue optical properties change following photodynamic therapy (PDT) of H-SIL in vivo. Using the frequency domain photon migration technique, non-invasive measurements of normal and dysplastic ecto-cervical tissue optical properties, i.e. absorption (μa) and effective scattering coefficients, and physiological parameters, i.e. tissue water and haemoglobin concentration, percentage oxygen saturation (%SO2), were performed on 10 patients scheduled for PDT of histologically-proven H-SIL. Cervix absorption and effective scattering parameters were up to 15% lower in H-SIL sites compared with normal cervical tissue for all wavelengths studied (674, 811, 849, 956 nm). Following PDT, all μa values increased significantly, due to elevated tissue blood and water content associated with PDT-induced hyperaemia and oedema. Tissue total haemoglobin concentration ([TotHb]) and arterio-venous oxygen saturation measured in H-SIL sites were lower than normal sites ([TotHb]: 88.6 ± 35.8 μmol/l versus 124.7 ± 22.6 μmol/l; %SO2: 76.5 ± 14.7% versus 84.9 ± 3.4%

Enhanced critical current density of YBa2Cu3Ox films grown on Nd1/3Eu1/3Gd1/3Ba2Cu3Ox with nano-undulated surface morphology

We report a simple and easily controllable method where a nano-undulated surface morphology of Nd1/3Eu1/3Gd1/3Ba2Cu3Ox (NEG) films leads to a substantial increase in the critical current density in superconducting YBa2Cu3Ox (YBCO) films deposited by pulsed laser deposition on such NEG layers. The enhancement is observed over a wide range of fields and temperatures. Transmission electron microscopy shows that such YBCO films possess a high density of localized areas, typically 20 x 20 nm2 in size, where distortion of atomic planes give rotational (2 to 5 degrees) moire patterns. Their distribution is random and uniform, and expected to be the origin of the enhanced flux pinning. Magneto-optical imaging shows that these films have excellent macroscopic magnetic uniformity.Comment: 4 pages, 4 figure

Root rot pathogens of Cinnamomum cassia in Vietnam

A study was conducted to determine the pathogens causing root rot, wilt and dieback disease of Cinnamomum cassia (Chinese cinnamon or cassia) in Vietnam, in nurseries and plantations in the Yen Bai, Quang Ninh, Thanh Hoa and Quang Nam provinces, and streams in the Yen Bai province. Pathogens were identified using morphology and internal transcribed spacer (ITS) sequence analysis. The 204 isolates obtained included 125 Phytophthora isolates and 79 from other oomycete genera. There were 112 isolates of P. cinnamomi, four P. heveae, two P. virginiana, three P. multibullata and four P. × vanyenensis. The pathogenicity and virulence of 16 P. cinnamomi, two P. heveae, two P. multibullata and four P. × vanyenensis isolates were assessed using lesion size after under-bark inoculation of C. cassia stems, and root damage following inoculation of 4-month-old C. cassia seedlings. The most virulent isolate from both assessments was a P. cinnamomi from the Quang Nam plantation. Isolates of P. cinnamomi showed a wide range of virulence, with isolates from healthy trees or seedlings showing the lowest virulence. Isolates of P. × vanyenensis, P. multibullata and P. heveae showed moderate or low pathogenicity. This study showed that although P. cinnamomi is the most common pathogen associated with dieback disease in Vietnamese C. cassia plantations, other Phytophthora species may also cause this disease. Knowledge of the presence of these soil- and waterborne pathogens will encourage improved soil and water hygiene in nurseries and implement measures to prevent the spread of the pathogens in plantations

A comprehensive study in efficacy of Vietnamese herbal extracts on whiteleg shrimp (<em>Penaeus vannamei</em>) against <em>Vibrio parahaemolyticus</em> causing acute hepatopancreatic necrosis disease (AHPND)

Traditional Vietnamese herbal species were examined for their antimicrobial activity and disease resistance in whiteleg shrimp. In-vitro screening, the extracts of ten herbs were conducted to test the inhibition ability against Vibrio parahaemolyticus, causing acute hepatopancreatic necrosis disease. The results showed that five out of ten herbal species, including Pithecellobium dulce, Melaleuca leucadendron, Eucalyptus globulus, Mimosa pirga, and Hibiscus sabdariffa displayed potent antibacterial activity. Besides, three types of extracts of H. sabdariffa, E. globulus, and M. pirga were coated to the pellet feed at a concentration of 1%. After 30 days of feeding, the whiteleg shrimp (Penaeus vannamei) were challenged by V. parahaemolyticus through immersion. The growth performance (such as growth rate in length and weight, survival rate), hematological parameters of total hemocytes (THC), hyaline hemocytes (HC), and granulocytes (GC), and hepatopancreas recovery under the treatments with herbal extracts of the whiteleg shrimp were significantly enhanced as compared with the control (without herbal extract). The mortality and the bacterial density in the hepatopancreas of shrimp decreased. Specifically, the mortality of shrimp in the treatment supplemented with the methanol extract of H. sabdariffa was the lowest, followed by M. pirga and E. globulus. The experimental results also indicated that H. sabdariffa, E. globulus, and M. pirga could improve immune parameters and disease resistance; therefore, they should be employed in sustainable shrimp, practical farming

Effects of salinity and alkalinity on growth and survival of all-male giant freshwater prawn (Macrobrachium rosenbergii De Man, 1879) juveniles

All-male giant freshwater prawns (AMGFPs) have been a popular crop cultivated in the Mekong Delta, Vietnam, due to their proven production efficiency compared to all-female or mixed-sex prawn cultures. However, the crucial water quality factors impacting AMGFP aquaculture efficiency have yet to be elaborately investigated. Two separate experiments were randomly arranged with three replicates to evaluate the effects of salinity or alkalinity on the growth and survival of AMGFP juveniles during the grow-out period. The results show that the prawn survival rate in the salinity range of 0–15‰ varied from 66.1 to 74.8％ and in a salinity range of 0–5‰ was relatively low compared to the range of 10-15‰; however, the difference was not significant among salinities after 90 days of culture (p > 0.05). All the prawn growth performance parameters significantly decreased with increasing salinities of 0, 5, 10, and 15‰ after 30, 60, and 90 days of culture (p 0.05), and both were significantly higher than those at salinities of 10 and 15‰ (p < 0.05) after 90 days of culture. In addition, the survival rate reached 82.5–84.4％ and did not significantly differ among alkalinities of 80, 100, 120, 140, and 160 mgCaCO3 L−1. However, the growth performance parameters and yield of AMGFPs at an alkalinity of 160 mg L−1 were significantly higher than those at lower alkalinities (80, 100, 120, and 140 mg CaCO3 L−1) after 90 days of culture. Therefore, it is recommended that a salinity range of 0–5‰ and alkalinity of 160 mgCaCO3 L−1 is optimal for the growth-out culture of AMGFP juveniles