High level of hybridisation in three species of Indian major carps

Thirty individuals of each species of Indian major carps, i.e., Catla catla, Cirrhinus cirrhosus (C. mrigala) and Labeo rohita, obtained from a nursery near Mymensingh, Bangladesh were analysed by means of allozyme electrophoresis. Twenty-one loci were studied. Several loci revealed significant deviation from Hardy-Weinberg expectations caused by deficiency of heterozygotes, indicating Wahlund effects due to problems with species identification. Moreover, bimodal distributions of individual heterozygosity within the three putative species indicated hybridisation. This was confirmed using analysis of individual admixture proportions, as individuals misidentified to species and hybrids between species were observed. Furthermore, factorial correspondence analysis to visualize genetic relationships among individuals revealed three distinct groups containing misclassified individuals, along with some intermediate individuals interpreted as hybrids. Ten per cent of all C. catla and L. rohita had been erroneously identified to species, and 40 per cent of all presumptive C. catla were hybrids between C. catla x C. cirrhosus and C. catla x L. rohita. In the case of C. cirrhosus, 37 per cent of the samples were C. cirrhosus x L. rohita hybrids. Thirty per cent of all presumptive L. rohita turned out to be hybrids between L. rohita x C. catla and L. rohita x C. cirrhosus. The high incidence of hybrids in C. catla might be responsible for slower growth of the fish in aquaculture

High level of hybridisation in three species of Indian major carps

Thirty individuals of each species of Indian major carps, i.e., Catla catla, Cirrhinus cirrhosus (C. mrigala) and Labeo rohita, obtained from a nursery near Mymensingh, Bangladesh were analysed by means of allozyme electrophoresis. Twenty-one loci were studied. Several loci revealed significant deviation from Hardy-Weinberg expectations caused by deficiency of heterozygotes, indicating Wahlund effects due to problems with species identification. Moreover, bimodal distributions of individual heterozygosity within the three putative species indicated hybridisation. This was confirmed using analysis of individual admixture proportions, as individuals misidentified to species and hybrids between species were observed. Furthermore, factorial correspondence analysis to visualize genetic relationships among individuals revealed three distinct groups containing misclassified individuals, along with some intermediate individuals interpreted as hybrids. Ten per cent of all C. catla and L. rohita had been erroneously identified to species, and 40 per cent of all presumptive C. catla were hybrids between C. catla x C. cirrhosus and C. catla x L. rohita. In the case of C. cirrhosus, 37 per cent of the samples were C. cirrhosus x L. rohita hybrids. Thirty per cent of all presumptive L. rohita turned out to be hybrids between L. rohita x C. catla and L. rohita x C. cirrhosus. The high incidence of hybrids in C. catla might be responsible for slower growth of the fish in aquaculture.Hybridization, DNA, Freshwater fish, Fish culture, Allozymes, Growth, Bangladesh, Catla catla, Cirrhinus cirrhosus, Cirrhinus mrigala, Labeo rohita

Local partnership approach for urban development in Bangladesh: a comparative study of four participatory urban development projects

Support for Implementation of National Plans of Action or SINPA is a programme that aims to implement some of the ideas of Habitat II and National Plans of Action for Human Settlements by supporting efforts of pilot cities and disseminating the results. SINPA activities are carried out in three countries, Bangladesh, Bolivia and Zambia in three continents. Apart from these three programmes in three countries, SINPA also has a core programme at the Institute for Housing and Urban Development Studies (IHS) in Rotterdam, the Netherlands, responsible for overall coordination of the country specific programmes, research and dissemination. Under this core programme, a third country research component was designed to conduct a joint research together with a local research institute. There were two considerations for undertaking this research. First, the subject matter of the research should be relevant for the ongoing programmes in the three SINPA countries, as well as being suitable for wider international dissemination. And second, the selection criteria for the research subject should be manageable in such a manner that adequate secondary data and documentations are available to make the study feasible within budget and time limits. The responsibility of the present study on “Local Partnership Approach for Urban Development in Bangladesh” has been given by IHS to the Centre for Urban Studies, Dhaka, under the SINPA Core Programme Research Component

Allozyme and morphological variation in four hatchery stocks of Thai pangas, Pangasius hypophthalmus in Mymensingh, Bangladesh

Genetic and morphological characters of four hatchery population (Shambhuganj, Brahmaputra, Anudan and Bhai-Bhai) of Thai pangas, Pangasius hypophthalmus in Mymensingh region of Bangladesh was studied using morphological characters and allozyme markers from 29 November 2001 to 29 November 2002. A total of 14 morphometric and 6 meristic characters were verified, among which 3 morphometric (BDA, PELFL and HW) and 2 meristic characters (AFR, CFR) of Anudan hatchery population were found to be significantly higher (p>0.001) than those of the other three hatchery populations. Brahmaputra hatchery population was also significantly higher in two meristic characters (PCFR and CFR). For allozyme electrophoresis nine enzyme markers were used viz.: Esr-1*, G3pdh-2*, Gpi-1*, Gpi-2*, Ldh-1*, Ldh-2*, Mdh-1*, Mdh-2* and Pgm* where three loci (Esr-1*, Gpi-2* and Pgm*) were polymorphic (p>0.95) in Anudan and Brahmaputra hatchery populations. The mean proportion of polymorphic loci per population was higher (33.3%) in Brahmaputra and Anudan hatchery populations. Also the expected heterozygosity levels were 0.149 and 0.177 in Brahmaputra and Anudan hatchery populations, respectively. Based on Nei's (1972) genetic distances, the UPGMA dendrogram grouped the populations into two clusters. The Brahmaputra and Anudan populations are in one group; Shambhuganj, and Bhai-Bhai populations are in the second group. High genetic variation in Thai pangas was observed in the Brahmaputra and Anudan hatchery populations and less variation in the other two hatchery populations

Year-round and rotational freshwater prawn, Macrobrachium rosenbergii and paddy farming: soil quality, production and economics

A study was carried out at five upazillas (Dumuria, Fakirhat, Pirojpur sadar, Gopalgonj sadar and Kalia) of five southern districts of Khulna, Bagerhat, Pirojpur, Gopalgonj and Narail to understand the comparative production performance and any effect on soil quality in case of year-round golda (Macrobrachium rosenbergii), alternate prawn-paddy and year-round paddy farming. A direct interview of 55 farmers was taken, using pretested questionnaire, and soil samples were taken from selected farms before and after each crop. Among the five upazillas, farmers in Gopalgonj sadar and Kalia are not practicing year-round golda. Rotational golda-paddy farming has been recorded to result in maximum profit, with the highest of Tk. 310,912/ha/year in 2003 at Dumuria. Only paddy farming is less profitable than other two cropping patterns, irrespective of study sites. The nutrient status of soil in rotational golda and paddy farming has been found improved, compared to that of only golda or paddy farming

Smoking of shrimp and fish from coastal village of north-west Bangladesh

Traditional smoking of mixed shrimp species is a method of preservation in coastal region of Bangladesh. Besides traditional smoked shrimp, attempt had been made to produce smoked shrimp from brown shrimp, Metapenaeus monoceros and fish from mugil, Liza parsia and the quality of smoked product was found good very on the basis of physical properties, proximate composition and mineral contents of the products

Sub-Micron CMOS Characterisation for Single Chip Wireless Applications

This paper describes a multifunctional, electronically reconfigurable, small/large signal load pull measurement system and its integrated use with BSIM 3v3 for modelling of sub-micron CMOS transistors and sub-circuits. This turnkey measurement system can be electronically configured from a battery of instruments in order to characterise minimum noise, optimum power, intermodulation, dc and S-parameters, together with harmonic response and dynamic load line information under both source and load pull conditions. The instrumentation provides validation data against the BSIM physical model simulator. Hence, for the first time measurement of all of the significant devices parameters can be made for the device operated under all possible primary modes for model validation so that optimal circuit design can be carried out in a holistic fashion

Polyculture of carps using over-wintered fingerlings under different stocking densities

An on-farm trial was undertaken in twelve earthen ponds (1200-1600 m') to evaluate the growth and production of over-wintered fingerlings of rohu (Labeo rohita), catla (Carla catla) and mrigal (Cirrhinus rnrigala) in polyculture at three stocking densities. The stocking densities were 2,250; 3,250 and 4,250 fish/ha in treatment-1, treatment-2 and treatment-3, respectively. Fish in all ponds were fed with rice bran and mustard oil cake at the ratio of 3:1. Fish production obtained in three treatments were 2325±74.75, 2620±49.66 and 2982±171.52 kg/ha. The results demonstrated higher mean growth in T-1 than in T-2 and T-3. However, the highest production as well as net benefit was obtained in treatment-3

Identification of Flash floods using Soil Flux and CO2: An implementation of Neural Network with Less False Alarm Rate

Flash floods are very sudden and abrupt and are the major root cause of casualties and loss of infrastructure. Flash floods can be regarded as the topmost natural disasters in many countries. Usually floods are due to high precipitation, wind velocity, water wave current and melting of ice bergs. Diversified strategies have been designed and applied to identify the flash floods. Mainly dozen of sensors have been utilized to detect the flash floods like upstream level, rainfall intensity, run-off magnitude, run-off speed, color of the water, precipitation velocity, pressure, temperature, wind speed, wave current pattern and cloud to ground (CG flashes). Ultrasonic and passive infrared (PIR) sensors have also been utilized for this purpose. Sensors generate high amount of fake alerts due to the incompetent algorithms. In our research we have proposed a novel approach analysis of soil flux depicting atmospheric carbon dioxide level as the plants take smaller amount of water from the soil due to the heightened levels of carbon dioxide. Due to this newly discovered research the soil is saturated abruptly causes more floods and run-offs. In our research we have reduced the false alarms and reduced the false alarms by using scaled conjugate gradient back propagation. Simulation results showed that scaled conjugate gradient propagation performed better than the other previous methods