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Abstract Edwardsiella ictaluri is a causative agent of enteric septicemia of catfish (ESC), a seriously lethal disease in Vietnamese catfish (Pangasius hypophthalmus). A safe and effective vaccine against ESC is currently an urgent demand due to antibiotic overuse in pangasius farms has led to an alarming antimicrobial resistance. In this study, two E. ictaluri wzz E mutants (WzM-L3, deficient in a 1038bp-entire wzz E gene and WzM-S3, a 245bp-partial deletion of wzz E) were developed and their protection efficiacy was evaluated in hatched pangasius against ESC by immersion vaccination. As comparing to the high virulent wild-type strain who caused 73.33% of death on pangasius fingerlings immersed at 7.1 × 106 CFU ml−1, both mutants showed extremely low mortality rates at 3.33% (WzM-S3) and 0% (WzM-L3) on pangasius fingerlings immersed at high concentration of 1.5 × 107 CFU mL−1 and 9.7 × 106 CFU ml−1, respectively. Interestingly, both WzM-S3 and WzM-L3 had a remarkably high protection against ESC, as RPS % were found at 89.29% and 90%, respectively. The mutant WzM-L3 is a potential live attenuated vaccine against ESC in Vietnamese catfish farms with good protection and simple practice. Highlights • ECA chain length is modulated by WzzE, a vital scaffold protein in ECA biosynthesis pathway. • WzzE, encoded by wzz E in wec cluster, is conserved and prevalent among Enterobacteria. • Mutant Δ wzz E of E. ictaluri showed attenuated and effective in protecting pangasius against ESC disease by immersion [ABSTRACT FROM AUTHOR]

We propose and analyze in details the revised model of XPROB, an infinite family of pool-based anonymous communication systems that can be used in various applications including high performance computing environments. XPROB overcomes the limitations of APROB Channel that only resists a global delaying adversary (GDA). Each instance of XPROB uses a pool mix as its core component to provide resistance against a global active adversary (GAA), a stronger yet more practical opponent than a GDA. For XPROB, a GAA can drop messages from users but cannot break the anonymity of the senders of messages. Analysis and experimental evaluations show that each instance of XPROB provides greater anonymity than APROB Channel for the same traffic load and user behaviors (rate and number of messages sent). In XPROB, any message can be delivered with high probability within a few rounds after its arrival into the system; thus, an opponent cannot be certain when a message will be delivered. Furthermore, users can choose their own preference balance between anonymity and delay. Through the evaluation, we prove that XPROB can provide anonymity for users in high-performance computing environments. [ABSTRACT FROM AUTHOR]

In many developing countries there is a prevailing conflict between biodiversity conservation and the need for poverty alleviation. One possible solution for solving that conflict is to find ways that help poor people directly benefit from conservation activities. This approach has been tested in a wetland conservation project in Phu My village, Kien Luong District, Kien Giang Province in Vietnam. The 2,000-hectare seasonally inundated grassland, dominated by the sedge Lepironia articulata (Cyperaceae), in Phu My Village is the last of its kind remaining in the Mekong Delta. In November 2004, a new model of protected area was therefore established. Unlike other protected areas in Vietnam where resource exploitation is prohibited, this is an “open” protected area in the sense that the local Khmer ethnic minority people are still allowed to harvest Lepironia as they have been doing for hundreds of years. The project provides local people with skills training and production equipment so that they can make fine handicrafts from the Lepironia they harvest. The project also helps with marketing handicraft products to higher profitable export markets. After three years of operating, the daily income of people who participated was on average twice as much as it was before the project began. The unique remnant wetland is protected, which would otherwise have been turned into a rice cultivation area according to the previous land use planning of Kien Giang Province. [ABSTRACT FROM AUTHOR]

Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth. The Indo-Pacific region holds most of the world's mangrove forests, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers. This decline is of particular concern because the Indo-Pacific region is expected to have variable, but high, rates of future sea-level rise. Here we analyse recent trends in mangrove surface elevation changes across the Indo-Pacific region using data from a network of surface elevation table instruments. We find that sediment availability can enable mangrove forests to maintain rates of soil-surface elevation gain that match or exceed that of sea-level rise, but for 69 per cent of our study sites the current rate of sea-level rise exceeded the soil surface elevation gain. We also present a model based on our field data, which suggests that mangrove forests at sites with low tidal range and low sediment supply could be submerged as early as 2070. [ABSTRACT FROM AUTHOR]

Abstract: Plantations released from management are vulnerable to transient oscillations until cohort dynamics are broken and the vertical and horizontal structures of the plantation are transformed to those of more natural forests. Cohort-desynchronizing factors such as canopy disturbances are expected to accelerate this process. Using well-established mangrove plantations in Can Gio (Viet Nam) as an example, we tested whether lightning gaps can affect transition dynamics of plantations to more natural forests by damping the amplitude or by shortening the period of oscillations in tree densities. This was done by applying point pattern analyses to remotely sensed data, and by further combining statistical and individual-based modelling. The occurrence of lightning gaps was biased by the forest matrix, which presented a challenge for the point pattern analysis. This problem was solved by using the scattered forest area as a binary mask. A Matern cluster process model was found to be suitable for describing the lightning regime. This statistical model was incorporated into the individual-based mangrove model KiWi, and simulation experiments revealed that: (i) the evenly spaced distribution of the tree cohorts in the plantation supports non-linear transition behaviour, i.e. oscillation of tree density, and (ii) the lightning regime in Can Gio damps the oscillation amplitude but is not sufficient to prevent the latter nor to decrease the length of the period of oscillations. [Copyright &y& Elsevier]