Effectiveness of the Vietnamese Good Agricultural Practice (VietGAP) on plant growth and quality of Choy Sum (Brassica rapa var. Parachinensis) in Northern Vietnam

In response to the recent concerns about human health, ecosystem sustainability and thus demands for food safety, production of clean produce, particularly daily-consumed vegetables, is essential. The study was carried out in Thai Nguyen city (northern Vietnam) during August – November 2011 to evaluate impacts of a VietGAP guideline on plant growth and quality of Choy Sum, one of the major vegetables in the research area. The experiment comprised two treatments, a control (local farmers’ conventional practice) and an experimental treatment (plants grown according to the VietGAP guideline). Plant samples of the latter treatment were collected for quality test at the end of the experiment. Results showed that the experimental plants had significant higher growth parameters with regards to leaf areas (7.13 dm2) and average top plant weight (3.33 kg m-2), while those of the control treatment were 5.80 dm2 and 2.77 kg m-2, respectively. Lab test results showed the experimental plant samples met the national quality standards to be certified as a clean product. The participatory on-field experiment would facilitate critical reflections, transformative learning and readiness for adoption of eco-friendly production practices by the local farmer

Developing an Integrated Pest Management Program for Tomatoes in the Red River Delta of Vietnam: a Mini Review

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

Effectiveness of the Vietnamese Good Agricultural Practice (VietGAP) on plant growth and quality of Choy Sum (Brassica rapa var. Parachinensis) in Northern Vietnam

In response to the recent concerns about human health, ecosystem sustainability and thus demands for food safety, production of clean produce, particularly daily-consumed vegetables, is essential. The study was carried out in Thai Nguyen city (northern Vietnam) during August – November 2011 to evaluate impacts of a VietGAP guideline on plant growth and quality of Choy Sum, one of the major vegetables in the research area. The experiment comprised two treatments, a control (local farmers’ conventional practice) and an experimental treatment (plants grown according to the VietGAP guideline). Plant samples of the latter treatment were collected for quality test at the end of the experiment. Results showed that the experimental plants had significant higher growth parameters with regards to leaf areas (7.13 dm2) and average top plant weight (3.33 kg m-2), while those of the control treatment were 5.80 dm2 and 2.77 kg m-2, respectively. Lab test results showed the experimental plant samples met the national quality standards to be certified as a clean product. The participatory on-field experiment would facilitate critical reflections, transformative learning and readiness for adoption of eco-friendly production practices by the local farmer

Migration patterns and winter population dynamics of rice planthoppers in Indochina: New perspectives from field surveys and atmospheric trajectories

This is the author accepted manuscript. The final version is available from Elsevier Masson via the DOI in this record.Rice planthoppers (RPH) are the most serious insect pests of rice production in East Asia, frequently out-breaking in China, Korea and Japan each summer. They are unable to overwinter in temperate East Asia, and summer populations arise anew each year via northward spring migration from south-east Asia. The annual migration cycle is generally believed to be a closed loop with mass returns to south-east Asia in the autumn, but this leg of the journey and the overwintering dynamics are much less studied than the spring immigrations. Previous studies have indicated that the north-central Vietnam (NCV) region is a key location for both the spring colonisation of China and for receiving return migrants from southern China each autumn. However, NCV experiences a three-month rice-free fallow period during mid-winter, and so it cannot be the principal over-wintering region for RPH populations. In this study, the continental-scale migration patterns of RPH in East Asia were explored using data from light trap catches, field surveys and atmospheric trajectory simulations. Our results confirmed that large numbers of return migrants arrive in NCV from southern China each autumn, but that they are unable to survive there over winter. The NCV region is recolonised in the early-spring (mid-February to mid-March) of each year by migrants from winter rice-growing regions in north-east Thailand, southern Laos and south-central coastal Vietnam, which are transported on favourable high-altitude synoptic winds. The following generation initiates the colonisation of East Asia from a large source population in NCV. Our results provide a new perspective on RPH migration patterns and over-wintering dynamics in East Asia, which is governed by crop production, environmental conditions and synoptic wind patterns at a continental scale.National Natural Science Foundation of China (NSFC)Natural Science Foundation of Jiangsu ProvinceBiotechnology and Biological Sciences Research Council (BBSRC)Science and Technology Facilities Council (STFC

Necessary and Sufficient Conditions for Agribusiness Success of Small-scale Farming Systems in Northern Vietnam

This study was conducted in Haiphong (Vietnam) during 2013-2014 to analyse the requirements for the success of small-scale agribusinesses. Following two baseline studies on the current state of the local farming systems and market situations, various stakeholders were engaged in a number of workshops with support of a causal loop diagram (CLD) modelling tool to redefine the pre-requisites for agribusiness success and their interplays. As a result, multi-stakeholder collaboration and government support via its policies and development programs were identified as the necessary conditions for success. Nonetheless, strengthening the capacity of local cooperatives and investing in human and social capitals are of equal importance as sufficient conditions, which generate multiple benefits towards achieving agribusiness success. Values of full participation by all stakeholders and the use of the CLD in defining systemic interventions are also discussed

Network Coding with Multimedia Transmission and Cognitive Networking: An Implementation based on Software-Defined Radio

Network coding (NC) is considered a breakthrough to improve throughput, robustness, and security of wireless networks. Although the theoretical aspects of NC have been extensively investigated, there have been only few experiments with pure NC schematics. This paper presents an implementation of NC under a two-way relay model and extends it to two\ua0non-straightforward scenarios: (i) multimedia transmission with layered coding and multiple-description coding, and (ii) cognitive radio with Vandermonde frequency division multiplexing (VFDM). The implementation is in real time and based on software-defined radio (SDR). The experimental results show that, by combining NC and source coding, we can control the quality of the received multimedia content in an on-demand manner. Whereas in the VFDM-based cognitive radio, the quality of the received content in the primary receiver is low (due to imperfect channel estimation) yet retrievable. Our implementation results serve as a proof for the practicability of network coding in relevant applications

Effect of surfactants on the deformation and break-up of an aqueous drop in oils under high electric field strengths

Understanding the deformation and break-up of drops is of great significance in various applications such as emulsification and phase separation. Most practical systems contain surface-active agents that are present as impurities affecting the properties of the system, e.g. modifying the rigidity of the film that affects emulsion stability. In this paper, the effect of surfactants on the deformation and break-up of an aqueous drop in an immiscible dielectric oil under the action of an electric field is addressed. The experiments were carried out on a single drop in a microscopic cell under an applied external electric field. A nonionic surfactant, polyethylene glycol sorbitan monolaurate (Tween 20), and an ionic surfactant, sodium dodecyl sulfate (SDS), were used at different concentrations. The drop adopted in most cases a prolate shape. However, the presence of the surfactant affected both the extent of deformation and the modes of break-up. The drop deformation extent increased rapidly with the surfactant concentration, while smaller drops deformed less under the same external electric field strength. When the surfactant concentration was high, the position of break-up could be from both poles along the main axis of the drops in the direction of the electric field

Social entrepreneurs in challenging places: A Delphi study of experiences and perspectives

Social Enterprises have grown in number and scope in response to reductions in state-provided welfare and increasing ambition to improve social conditions. While a range of issues have been identified in the literature as affecting the ability of Social Enterprises to successfully conduct their activities, there is currently a dearth of research into the relative influence of these factors. This study explores and ranks the challenges faced by social entrepreneurs in South Wales. Based on a Delphi study with 21 social entrepreneurs, government policy-developers and scholars, it presents a hierarchy of 14 factors, useful instruments for informing social entrepreneurs and policy-makers about the way social enterprises are managed, and how national and local policy should be developed. As part of this, the study also identifies four novel factors that affect the sustainability of social enterprises: ‘Professionalisation of Marketing’, ‘Perception of Validity’, ‘Leadership’ and ‘Situatedness’

Energy-efficient precoding in multicell networks with full-duplex base stations

© 2017, The Author(s). This paper considers multi-input multi-output (MIMO) multicell networks, where the base stations (BSs) are full-duplex transceivers, while uplink and downlink users are equipped with multiple antennas and operate in a half-duplex mode. The problem of interest is to design linear precoders for BSs and users to optimize the network’s energy efficiency. Given that the energy efficiency objective is not a ratio of concave and convex functions, the commonly used Dinkelbach-type algorithms are not applicable. We develop a low-complexity path-following algorithm that only invokes one simple convex quadratic program at each iteration, which converges at least to the local optimum. Numerical results demonstrate the performance advantage of our proposed algorithm in terms of energy efficiency

Protective and Enhancing HLA Alleles, HLA-DRB1*0901 and HLA-A*24, for Severe Forms of Dengue Virus Infection, Dengue Hemorrhagic Fever and Dengue Shock Syndrome

Dengue has become one of the most common viral diseases transmitted by infected mosquitoes (with any of the four dengue virus serotypes: DEN-1, -2, -3, or -4). It may present as asymptomatic or illness, ranging from mild to severe disease. Recently, the severe forms, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), have become the leading cause of death among children in Southern Vietnam. The pathogenesis of DHF/DSS, however, is not yet completely understood. The immune response, virus virulence, and host genetic background are considered to be risk factors contributing to disease severity. Human leucocyte antigens (HLA) expressed on the cell surface function as antigen presenting molecules and those polymorphism can change individuals' immune response. We investigated the HLA-A, -B (class I), and -DRB1 (class II) polymorphism in Vietnamese children with different severity (DHF/DSS) by a hospital-based case-control study. The study showed persons carrying HLA-A*2402/03/10 are about 2 times more likely to have severe dengue infection than others. On the other hand, HLA-DRB1*0901 persons are less likely to develop DSS with DEN-2 virus infection. These results clearly demonstrated that HLA controlled the susceptibility to severe forms of DV infection