Search

Climate change increase the probability of soil waterlogging due to severe rainfall. A low oxygen concentration in soil (hypoxia) is a major problem associated with waterlogging, and root development is an important indicator of resistance. However, little is known about the root development responses of sweet potato to hypoxia under waterlogging. In this study, the root hypoxia tolerance of four sweet potato cultivars was investigated using three environments (hydroponics, soil in pots, and upland field). In the hydroponic experiment, at 4 days after transplanting (DAT), the plants were transferred to either normoxia (control) or hypoxia and grown for 7 more days. In the soil pot experiment, seedlings at 7 DAT were grown for another 7 days under one of two treatments: drained (control) or waterlogging conditions. The root systems of individual plants were scanned with an image scanner using the WinRhizo software to measure root morphological traits. All the cultivars were tested for tuberous root performance under field waterlogging conditions imposed at the seedling stage. The obtained results showed that the root development responses to hypoxia were clearly associated and contributed to waterlogging tolerance in sweet potato plants. Of the four sweet potato varieties investigated, we identified Cuc Nhanh as the most waterlogging-tolerant variety and hence, it was noted as a promising and important genetic plant resource. The results of this study on root responses, hypoxia, and waterlogging relationships are fundamental towards exploring the mechanisms underlying hypoxia and waterlogging adaptation.

Many news publishers have integrated their news on Facebook to attract wider readership. On this popular social networking site, online news readers can contribute their comments to the news post and interact with their fellow readers. This form of user-generated contents has attracted increasing scholarship and raised concerns over the salient conflict and incivility in its language, the low quality of polarized argumentation, and the complex interaction among news commenters. To contribute to the current lack of in-depth qualitative description of such reader-reader interaction, the current study explores the types of communicative moves performed by Facebook users in their news comments, the patterning of those moves, and the attitudinal language used to realize such moves. Based on the two Systemic Functional Linguistic (SFL) frameworks of speech functions and appraisal for a close analysis of the moves and attitudinal lexis in Facebook news readers’ comments to one news article, the research has shown that exchanges of Facebook news comments developed in different directions with varying levels and complex patterns of support and confrontation between interactants as well as different appraisal language use. Besides substantiating the existing description of online news readers’ interaction, the paper argues that the SFL frameworks of conversation analysis are helpful for understanding CMC but more updated descriptions and a more visual approach to presentation of findings are needed to make the frameworks more relevant for online interactive discourses.

Water can make a substantial contribution to human life for drinking as well as purposes related to human life and human nature. Because of increasing demand for water, there is a need for dam construction in preparation for agricultural purposes, drinking, industry and also flood control, power generation, etc. Simultaneously, they have had a considerable impact on the environment. A large range of potential impacts and hazards linked to the exploitation of dams and reservoirs, such as: (i) Major change in flow regime, thermal regime, physico-chemical cycles, (ii) reduction or loss of biological diversity, particular in aquatic species, (iii) greenhouse gas emissions, (iv) increases in the number of infectious disease and accumulation of heavy metals in food web...Therefore, there are various potential health risks of the environment and residents. However, whilst dam effects are very well documented elsewhere in the world, little or no information about negative effects of dams on the environment is available from Vietnam. Consequently, this paper provides a brief review of the environmental impact of dam constructions and after that, we will investigate some strategies to deal with the effects for Vietnam. By the way, we give some insight into ​​the first studies on the impacts of dams on the environment, which focuses on aquatic species was also noted in paper.