No abstract

Coastal wetlands, such as saltmarshes and mangroves that fringe transitional waters, deliver important ecosystem services that support human development. Coastal wetlands are complex social-ecological systems that occur at all latitudes, from polar regions to the tropics. This overview covers wetlands in five continents. The wetlands are of varying size, catchment size, human population and stages of economic development. Economic sectors and activities in and around the coastal wetlands and their catchments exert multiple, direct pressures. These pressures affect the state of the wetland environment, ecology and valuable ecosystem services. All the coastal wetlands were found to be affected in some ways, irrespective of the conservation status. The main economic sectors were agriculture, animal rearing including aquaculture, fisheries, tourism, urbanization, shipping, industrial development and mining. Specific human activities include land reclamation, damming, draining and water extraction, construction of ponds for aquaculture and salt extraction, construction of ports and marinas, dredging, discharge of effluents from urban and industrial areas and logging, in the case of mangroves, subsistence hunting and oil and gas extraction. The main pressures were loss of wetland habitat, changes in connectivity affecting hydrology and sedimentology, as well as contamination and pollution. These pressures lead to changes in environmental state, such as erosion, subsidence and hypoxia that threaten the sustainability of the wetlands. There are also changes in the state of the ecology, such as loss of saltmarsh plants and seagrasses, and mangrove trees, in tropical wetlands. Changes in the structure and function of the wetland ecosystems affect ecosystem

The Mekong River Delta (MRD) is one of two primary rice-growing areas in Vietnam. Flooding in the Mekong River is a recurrent event and is not only one of the most destructive natural disasters but also a natural resource in this area. The cultivated surface soil layer in the Mekong Delta has a thickness of only about 50 cm, and is heavily polluted by acidic water infiltrating from deeper soil layers during the dry season. The annual floods carry fertile silt to farmland and fresh water to wash away the acidic water and provide the water needed to grow vast rice fields. The flood water carries with it various fish species that facilitate aquaculture development in the area. The floods also wash away polluted water and provide the whole delta with clean water.Owing to these different factors, the flooding in this area has a positive impact on agriculture and a negative impact on regional planning. Recent infrastructural changes designed to mitigate flood damage and protect crops and residents' lives make the inundation regime more complicated. To understand the role of infrastructure in the flood regime in this area as well as the mechanism of the flood regime, it is necessary to apply an integrated method of study including numerical modelling, a geographic information system (GIS), and statistical analyses. This study includes a brief presentation of the measured data analysis of flood variation trends over the 43-year period from 1961 to 2004 and an analysis of the hydrological effects of infrastructure changes associated with human activities in the period from 1996 to 2001 based on the integrated hydraulic model known as HydroGis.

Extensive studies regarding complete coverage problems have been conducted, but a few tackle scenarios where the mobile robot is equipped with reconfigurable modules. The reconfigurability of these robots creates opportunities to develop new navigation strategies with higher dexterity; however, it also simultaneously adds in constraints to the direction of movements. This paper aims to develop a valid navigation strategy that allows tetromino-based self-reconfigurable robots to perform complete coverage tasks. To this end, a novel graph theory-based model to simulate the workspace coverage and make use of dynamic programming technique for optimal path searching and adaptive robot morphology shifting algorithms is proposed. Moreover, the influence of algorithms starting variables on workspace coverage outcome is analyzed thoughtfully in this paper. The simulation results showed that the proposed method is capable of generating navigation paths throughout the workspace, which ensures complete workspace coverage while minimizing the total number of actions performed by the robot.INDEX TERMS Complete coverage path planning, self-reconfigurable robots, graph theory, dynamic programming, Dijkstra algorithm.

Context: Eurycomanone is found in the Eurycoma longifolia Jack (Simaroubaceae) tree, exhibits significant antimalarial activity, improves spermatogenesis, suppresses expression of lung cancer cell tumour markers and regulates signalling pathways involved in proliferation, cell death and inflammation.Objectives: Establishment of cell suspension culture of E. longifolia to determine the eurycomanone accumulation during cultures.Materials and methods: Callus of E. longifolia was cultured in MS medium supplemented with 0.8% agar, 30/L sucrose, 1.25 mg/L NAA and 1 mg/L KIN for biomass production. Cell suspension culture was established by transferring friable calli to the same medium without agar. Eurycomanone content during cell culture was determined by HPLC with a C18 column, flow rate of 0.8 mL/min, run time of 17.5 min, detector wavelength of 254 nm. The stationary phase was silica gel and the mobile phase was acetonitric:H2O. Roots of 5 year-old trees were used as the control.Results: The cells from 3 g of inoculum increased in biomass with a maximum value of 16 g fresh weight (0.7 g dry weight) at 14th day of culture. The cell growth then decreased from day 14 to day 20. Eurycomanone was produced during culture from the beginning to 20th day, its highest content (1.7 mg/g dry weight) also obtained at 14th day (the control is 2.1 mg/g dry weight).Discussion and conclusions: Cell suspension culture of E. longifolia is a suitable procedure to produce eurycomanone. The yield of eurycomanone biosynthesis in 14 days-old cells are relatively high, approximately 0.8 times the control.