Suitability of rich-fish culture under mono and polyculture systems in the boro rice ecosystem

An experiment was conducted in farmers’ fields under Paikgacha thana, Khulna to study the suitability of integrated rice-cum-fish culture. Three treatments namely T1 (Puntius gonionotus), T2 (Puntius gonionotus and Cyprinus carpio) and T3 ( Cyprinus carpio) were included for the study each having three replicates. The fish were stocked at a density of 3750/ha in all the rice plots. The physicochemical parameters of water viz., water depth, temperature, dissolved oxygen, pH, salinity, nitrate and phosphate etc. recorded during the study period were found within optimum range. Of the two cultured species C. carpio attained the highest average individual weight (160g) and survival (81.06%). With respect to biomass and income, highest average fish production and net profit per hectare (306.74kg and Tk. 8177.91) were obtained in T2 and the lowest (184.17kg and Tk. 2049.41) obtained in T1 and a significant variation (p<0.05) in fish production was observed among the treatments while for rice production, it was insignificant. The cost benefit ratio of fish production found were 1:1.29, 1:2.14 and 1:1.90 for T1, T2 and T3, respectively.

Sustainable livelihood approach of prawn production and marketing systems in Mymensingh, Bangladesh

An investigation was carried out in Phulpur upazila, Mymensingh to examine the current production practices of freshwater giant prawn, Macrobrachium rosenbergii and its marketing systems with sustainable livelihood approach. The livelihoods of a considerable number of rural poor are associated with prawn production in Phulpur upazila. Based on a sample of 50 farmers, about 94% farmers were found to culture prawn with fish in their ponds. Only 4% and 2% farmers were found to culture prawn-fish-dike crops and only prawn respectively. Prawn marketing is almost exclusively a preserve of the private sector where the livelihoods of a large number of people are associated with its distribution and marketing systems. The market chain from producers to consumers passes through a number of intermediaries. About 40% of the produced prawns are exported and the rest 60% are sold to local markets. The price of prawn depends on quality, size and weight. The average farm-gate price of prawn varied from Tk. 110 to 160/kg, whereas it's [sic] market price varied from Tk. 150 to 350/kg. Most of the farmers and traders have improved their socio-economic conditions through prawn farming and marketing activities. However, concerns arise about the long-term sustainability of prawn farming and marketing systems due to lack of technical knowledge of prawn farming, poor road and transport facilities, higher transport cost, poor supply of ice, lack of cash and credit facilities. It is therefore essential to provide institutional and organizational support and credit facilities for sustainable prawn production and marketing systems.

Report of the sub-regional workshop to validate the scoping study of nutrient pollution on the coastal and marine systems of South Asia, Colombo, Sri Lanka, 21-22 May, 2014

The workshop agenda included: presentations from collaborative institutions, national governments and resource persons; a draft scoping study on nutrient loading; and an ecosystem approach to pollution management was tested.

LES of heat transfer in electronics

Numerical methods based on the Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) equations are applied to the thermal prediction of flows representative of those found in and around electronics systems and components. Low Reynolds number flows through a heated ribbed channel, around a heated cube and within a complex electronics system case are investigated using linear and nonlinear LES models, hybrid RANS-LES and RANS-Numerical-LES (RANS-NLES) methods. Flow and heat transfer predictions using these techniques are in good agreement with each other and experimental data for a range of grid resolutions. Using second order central differences, the RANS-NLES method performs well for all simulations. © 2011 Elsevier Inc.

Microsatellite marker isolation and cultured strain identification in Carassius auratus gibelio

Microsatellites have become the preferred molecular markers for strain selection and genetic breeding in fish. In this study a total of 105 microsatellites were isolated and identified in gibel carp (Carassius auratus gibelio) by microsatellite sequence searches in GenBank and other databases and by screening and sequencing of positive clones from the genomic library enriched for AG and GATA repeats. Moreover, nineteen microsatellites were randomly selected to design locus-specific primer pairs, and these were successfully used to identify and discriminate different cultured strains of gibel carp including strains A, D, L, and F. Three different types of microsatellite pattern were distinguished by the number and length of fragments amplified from the 19 primer pairs, and some microsatellite primer pairs were found to produce different microsatellite patterns among strains and strain-specific fragments. In addition, some duplicated alleles were also detected in two microsatellite patterns. Therefore, the current study provides direct molecular markers to discriminate among different cultured strains for selective breeding and aquaculture practice of gibel carp.