An Giang province in the Mekong Delta is the most vulnerable province the impact of flooding and climate variability. Thousand of households are at risk due to severe annual floods. This study applied the LVI （liveli...An Giang province in the Mekong Delta is the most vulnerable province the impact of flooding and climate variability. Thousand of households are at risk due to severe annual floods. This study applied the LVI （livelihood vulnerability index） to estimate flood vulnerability of Phu Huu and Ta Danh villages in An Giang province. Data on socio-demographics, livelihoods, health, social networks, physical, financial and natural resources, natural disasters and climate variability were collected from a survey of 120 households in each village. From these data the LVI of each village was calculated. Results show that the overall LV1 of Phu Huu village, located in the early flooded zone, is higher than that of Ta Danh village, located in the late flooded zone. The analysis also indicated that this practical method can be applied for other purposes such as to monitor vulnerability, evaluate development programs or policy effectiveness by incorporating with scenario comparison.展开更多
GP64 is the major envelope glycoprotein associated with the budded virus (BV) of Autographa californica nucleopolyhedrovirus (AcMNPV) and is essential for attachment and budding of BV particles. Confocal microscopy an...GP64 is the major envelope glycoprotein associated with the budded virus (BV) of Autographa californica nucleopolyhedrovirus (AcMNPV) and is essential for attachment and budding of BV particles. Confocal microscopy and flotation assays established the presence of lipid raft domains within the plasma membranes of AcMNPV-infected Sf9 cells and suggested the association of GP64 with lipid rafts during infection. GP64 and filamentous actin (F-actin) were found to co-localise at the cell cortex at 24 and 48 hpi and an additional restructuring of F-actin during infection was visualised, resulting in a strongly polarised distribution of both F-actin and GP64 at the cell cortex. Depletion of F-actin, achieved by treatment of Sf9 cells with latrunculin B (LB), resulted in the redistribution of GP64 with significant cytoplasmic aggregation and reduced presence at the plasma membrane. Treatment with LB also resulted in reduced production of BV in Sf9 cells. Analysis of virus gene transcription confirmed this reduction was not due to decreased trafficking of nucleocapsids to the nucleus or to decreased production of infectious progeny nucleocapsids. Reduced BV production due to a lack of GP64 at the plasma membrane of AcMNPV-infected Sf9 cells treated with LB, suggests a key role for F-actin in the egress of BV.展开更多
BFT （Biofloc Technology） has been currently applied in Cantho University to a number of targeted species from fresh-to marine and saline water species in the Mekong Delta, e.g. striped catfish （Pangasianodon hypoph...BFT （Biofloc Technology） has been currently applied in Cantho University to a number of targeted species from fresh-to marine and saline water species in the Mekong Delta, e.g. striped catfish （Pangasianodon hypophthalmus）, white leg shrimp （Litopenaeus vannamei）, tiger shrimp （Penaeus monodon） and Artemia Vinhchau strain （Artemia franciscana） for both in the lab-scales or production scales. The best growth and survival rate of striped catfish was obtained in 6%o. For white leg shrimp, the results indicated： （1） C （Carbon） source e.g. rice-flour or molasses supplementary based on the feed provided to promote survival, growth and shrimp biomass harvested; （2） it was fed less than 20% as usual but showed similar to those in the control; （3） combination of rice-flour and molasses at a ratio of 70：30 by weight of C and N （Nitrogen） in a ration of 15：1 enhanced shrimp survival and growth; （4） in intensive culture, shrimp could be against the infection of disease and end up with higher survival, growth in earthen ponds. For tiger shrimp, a set up for larvae till post larvae at different ratios of C and N and C：N of 30 PLI5 displayed with better survival rate （49.73 ± 7.07%） and production （74,596 ± 10.608 PL/m3）. Artemiafranciscana was set up at C：N = 10：1 and salinities from 35, 60, 80 and 100 ppt. After two weeks, there were no significant difference among treatment and the control （without biofloc） in term of survival and growth. Moreover, total embryos per female was not significant different with the control and even the number of embryos as cysts tended to be higher. BFT displayed its advantages when applied on culture system of different targeted species and there is no doubt that it could help to sustain aquaculture and save environment in the Mekong Delta in near future.展开更多
Extreme rainfall events are primary natural hazards, which cause a severe threat to people and their properties in populated cities, which are normally located in coastal areas in Vietnam. Analysing these events by us...Extreme rainfall events are primary natural hazards, which cause a severe threat to people and their properties in populated cities, which are normally located in coastal areas in Vietnam. Analysing these events by using a data series observed over years will support us to draw a picture of how the climate change impact on local environments. The purpose of this report is to understand the characteristics of the extreme rainfall events in MEKONG river delta （south VietNam）. Daily rainfall data in the period of 30 years for a meteorological station in each area were collected from the Vietnam National Hydro-meteorological Service. The extreme rainfall events were defined as those exceeding the 95th percentile for each station. The analytical results show that the rainfall values （95th percentile） are 37.4 mm/day at Nam Can station, 27 mm/day at My Thanh station, 22.4 mm/day at Hoa Binh station, 23.8 mm/day at Binh Dai station and 22.7 mm/day at Ben Trai station. The highest rainfall data ever recorded are 246.4 mm/day （Nam Can）, 174.5 mm/day （My Thanh）, 179 mm/day （Hoa Bin_h）, 187.3 mm/day （Binh Dai） and 136.3 mm/day （Ben Trai） during 1983-2012. The result of the Mann-Kendall tests show that there was a significant creasing of the rainfall at Nam Can, My Thanh station in two periods （1983-2012, 1998-2012） while no clear trend of the rainfall was recoreded at Hoa Birth, Binh Dai, Ben Trai station. In order to estimate the return period of the extreme rainfall events, the method General Extreme Value Distribution was used to calculate frequent distribution. The magnitudes of daily maximum rainfall were from 2 to 100 years. The results of return period show that maximum rainfalls are 46.6 mm at Nam Can station （highest） and 31.4 mm at Hoa Birth station （lowest） during 50 years. Similarly, maximum rainfalls are expected to be about 55.1 mm at Nam Can station and 37.2 mm at Hoa Birth station for 100 years.展开更多
Water quality was investigated in shrimp culture areas in Cau Ngang, Tra Vinh where three culture systems were found in the same area to assess the impact of intensification of shrimp culture on the surrounding enviro...Water quality was investigated in shrimp culture areas in Cau Ngang, Tra Vinh where three culture systems were found in the same area to assess the impact of intensification of shrimp culture on the surrounding environment. Three culture systems were selected including intensive, semi-intensive and rice-shrimp alternated culture for the study. Monthly assessment of physical and chemical parameters of water and biotic parameters were done for a period of one year from March, 2009 to February, 2010 in the canals surrounding the culture systems. The physical chemical parameters of water recorded include temperature, pH, dissolved oxygen, chemical oxygen demand （COD）, total suspended solids （TSS）, total ammonium （TAN）, nitrite （N-NO2）, nitrate （N-NO3） and total nitrogen （TN）, total phosphorus （TP） in both water and sediment. Zooplankton and zoobenthos were determined quantitatively and qualitatively using zooplankton nets and Petersen grabs, respectively. The results indicated that most of water parameters were not significantly different between culture systems and were in suitable ranges for aquatic life within the national standard criteria except DO, TSS and TP at some periods. DO concentration in rice-shrimp system was significantly lower than that in other systems. TSS and TP concentrations both in water and sediment were high exceeding the limit ranges （〉 100 mg/L）. The occurrence of some zooplankton and zoobenthos species indicated that all systems were polluted at 13 level （mesosaprobic） in which the rice-shrimp alternated culture system subjected to more environmental fluctuation not only by shrimp culture but also rice cultivation and salinity variation between dry and rainy seasons.展开更多
文摘An Giang province in the Mekong Delta is the most vulnerable province the impact of flooding and climate variability. Thousand of households are at risk due to severe annual floods. This study applied the LVI （livelihood vulnerability index） to estimate flood vulnerability of Phu Huu and Ta Danh villages in An Giang province. Data on socio-demographics, livelihoods, health, social networks, physical, financial and natural resources, natural disasters and climate variability were collected from a survey of 120 households in each village. From these data the LVI of each village was calculated. Results show that the overall LV1 of Phu Huu village, located in the early flooded zone, is higher than that of Ta Danh village, located in the late flooded zone. The analysis also indicated that this practical method can be applied for other purposes such as to monitor vulnerability, evaluate development programs or policy effectiveness by incorporating with scenario comparison.
基金supported by aBBSRC grant (LAK, RDP)a BBSRC-funded PhDstudentship (FJH)
文摘GP64 is the major envelope glycoprotein associated with the budded virus (BV) of Autographa californica nucleopolyhedrovirus (AcMNPV) and is essential for attachment and budding of BV particles. Confocal microscopy and flotation assays established the presence of lipid raft domains within the plasma membranes of AcMNPV-infected Sf9 cells and suggested the association of GP64 with lipid rafts during infection. GP64 and filamentous actin (F-actin) were found to co-localise at the cell cortex at 24 and 48 hpi and an additional restructuring of F-actin during infection was visualised, resulting in a strongly polarised distribution of both F-actin and GP64 at the cell cortex. Depletion of F-actin, achieved by treatment of Sf9 cells with latrunculin B (LB), resulted in the redistribution of GP64 with significant cytoplasmic aggregation and reduced presence at the plasma membrane. Treatment with LB also resulted in reduced production of BV in Sf9 cells. Analysis of virus gene transcription confirmed this reduction was not due to decreased trafficking of nucleocapsids to the nucleus or to decreased production of infectious progeny nucleocapsids. Reduced BV production due to a lack of GP64 at the plasma membrane of AcMNPV-infected Sf9 cells treated with LB, suggests a key role for F-actin in the egress of BV.
文摘BFT （Biofloc Technology） has been currently applied in Cantho University to a number of targeted species from fresh-to marine and saline water species in the Mekong Delta, e.g. striped catfish （Pangasianodon hypophthalmus）, white leg shrimp （Litopenaeus vannamei）, tiger shrimp （Penaeus monodon） and Artemia Vinhchau strain （Artemia franciscana） for both in the lab-scales or production scales. The best growth and survival rate of striped catfish was obtained in 6%o. For white leg shrimp, the results indicated： （1） C （Carbon） source e.g. rice-flour or molasses supplementary based on the feed provided to promote survival, growth and shrimp biomass harvested; （2） it was fed less than 20% as usual but showed similar to those in the control; （3） combination of rice-flour and molasses at a ratio of 70：30 by weight of C and N （Nitrogen） in a ration of 15：1 enhanced shrimp survival and growth; （4） in intensive culture, shrimp could be against the infection of disease and end up with higher survival, growth in earthen ponds. For tiger shrimp, a set up for larvae till post larvae at different ratios of C and N and C：N of 30 PLI5 displayed with better survival rate （49.73 ± 7.07%） and production （74,596 ± 10.608 PL/m3）. Artemiafranciscana was set up at C：N = 10：1 and salinities from 35, 60, 80 and 100 ppt. After two weeks, there were no significant difference among treatment and the control （without biofloc） in term of survival and growth. Moreover, total embryos per female was not significant different with the control and even the number of embryos as cysts tended to be higher. BFT displayed its advantages when applied on culture system of different targeted species and there is no doubt that it could help to sustain aquaculture and save environment in the Mekong Delta in near future.
文摘Extreme rainfall events are primary natural hazards, which cause a severe threat to people and their properties in populated cities, which are normally located in coastal areas in Vietnam. Analysing these events by using a data series observed over years will support us to draw a picture of how the climate change impact on local environments. The purpose of this report is to understand the characteristics of the extreme rainfall events in MEKONG river delta （south VietNam）. Daily rainfall data in the period of 30 years for a meteorological station in each area were collected from the Vietnam National Hydro-meteorological Service. The extreme rainfall events were defined as those exceeding the 95th percentile for each station. The analytical results show that the rainfall values （95th percentile） are 37.4 mm/day at Nam Can station, 27 mm/day at My Thanh station, 22.4 mm/day at Hoa Binh station, 23.8 mm/day at Binh Dai station and 22.7 mm/day at Ben Trai station. The highest rainfall data ever recorded are 246.4 mm/day （Nam Can）, 174.5 mm/day （My Thanh）, 179 mm/day （Hoa Bin_h）, 187.3 mm/day （Binh Dai） and 136.3 mm/day （Ben Trai） during 1983-2012. The result of the Mann-Kendall tests show that there was a significant creasing of the rainfall at Nam Can, My Thanh station in two periods （1983-2012, 1998-2012） while no clear trend of the rainfall was recoreded at Hoa Birth, Binh Dai, Ben Trai station. In order to estimate the return period of the extreme rainfall events, the method General Extreme Value Distribution was used to calculate frequent distribution. The magnitudes of daily maximum rainfall were from 2 to 100 years. The results of return period show that maximum rainfalls are 46.6 mm at Nam Can station （highest） and 31.4 mm at Hoa Birth station （lowest） during 50 years. Similarly, maximum rainfalls are expected to be about 55.1 mm at Nam Can station and 37.2 mm at Hoa Birth station for 100 years.
文摘Water quality was investigated in shrimp culture areas in Cau Ngang, Tra Vinh where three culture systems were found in the same area to assess the impact of intensification of shrimp culture on the surrounding environment. Three culture systems were selected including intensive, semi-intensive and rice-shrimp alternated culture for the study. Monthly assessment of physical and chemical parameters of water and biotic parameters were done for a period of one year from March, 2009 to February, 2010 in the canals surrounding the culture systems. The physical chemical parameters of water recorded include temperature, pH, dissolved oxygen, chemical oxygen demand （COD）, total suspended solids （TSS）, total ammonium （TAN）, nitrite （N-NO2）, nitrate （N-NO3） and total nitrogen （TN）, total phosphorus （TP） in both water and sediment. Zooplankton and zoobenthos were determined quantitatively and qualitatively using zooplankton nets and Petersen grabs, respectively. The results indicated that most of water parameters were not significantly different between culture systems and were in suitable ranges for aquatic life within the national standard criteria except DO, TSS and TP at some periods. DO concentration in rice-shrimp system was significantly lower than that in other systems. TSS and TP concentrations both in water and sediment were high exceeding the limit ranges （〉 100 mg/L）. The occurrence of some zooplankton and zoobenthos species indicated that all systems were polluted at 13 level （mesosaprobic） in which the rice-shrimp alternated culture system subjected to more environmental fluctuation not only by shrimp culture but also rice cultivation and salinity variation between dry and rainy seasons.
