Inhibitory effect of <Emphasis Type="Italic">Pistia</Emphasis> tannin on digestive enzymes of Indian major carps: an in vitro study

Aquatic weeds are one of the major unconventional feed ingredients tested for aquafeed formulation. Tannin content in the water lettuce, Pistia, has been quantified (26.67 mg g⁻¹; dry weight) and graded levels of which (12.5–200 μg) have been incorporated in the reaction mixtures to evaluate any change in the in vitro activity of the principal digestive enzymes from the three Indian major carps (IMC), namely rohu (Labeo rohita), catla (Catla catla) and mrigala (Cirrhinus mrigala). Result of the experiment revealed that the Pistia tannin (PT) significantly inhibit/lower the activities of the digestive enzymes from three IMCs in a dose-dependant manner, even at very low concentration. Significant variation in the reduction of the enzyme activities was noticed between the three fish species, as well as between the three enzymes studied. Among the three species studied, digestive enzymes from L. rohita were found to be the most sensitive to the PT, whereas enzymes from C. catla were found to be comparatively least affected. On the other hand, protease and lipase activities were comparatively more affected than the amylase activity. The results of the study suggest that more stress should be given on the elimination of tannin while incorporating feed ingredients of plant origin in fish diets.     

Comparative analysis of genome of Edwardsiella tarda by BOX-PCR and PCR-ribotyping

The Genus Edwardsiella comprises of bacteria differing strongly in their biochemical characteristics, physiological features, natural habitat and pathogenic properties. The most common species of the genus is Edwardsiella tarda, recovered from a variety of environmental and animal sources. In this study 51 isolates including one reference strain obtained from freshwater culture systems were analyzed for their genomic diversity by BOX-PCR and PCR-ribotyping. By comparison of fingerprint of different isolates 27 and 32 genotypes were obtained by PCR-ribotyping and BOX-PCR respectively. Cluster analysis of genetic profile obtained by BOX-PCR and ribotyping clearly showed 9 and 8 clusters respectively. Some correlation between BOX-PCR and ribotyping was observed. Several clusters delineated on the basis of source of isolation in the dendrogram by BOX-PCR with 70% cut off value had corresponding clusters in the ribotyping with 50% cut off value. Some of the genotypes were found to be habitat specific. However, there was mixing and dispersal of most of the genotypes obtained from water, sediment and fish samples. Of both the techniques, BOX-PCR was found to be more discriminating than ribotyping.     

Landscape and land use effects on soil resources in a Himalayan watershed

Sustainable land management decisions at all scales require solid, science-based information. Soil quality assessment can provide this regarding soil physical, chemical, and biological characteristics and the ability to provide ecosystem and societal services. Our objective was to make a regional assessment of soils in the Garhwal Himalayas to determine their ability to perform various functions and respond to external influences. Five functional categories were assessed using 13 soil parameters focused on ecological sustainability. Human land use effects on soils were referenced to natural woodlands at each landscape position. Within upper-slope regions, flora and fauna habitat, moisture retention, organic matter and nutrient cycling, air and water infiltration and resistance to erosion were decreased 35, 27, 24, 24, and 9%, respectively. At mid-slope positions the order and magnitude of decrease were organic matter and nutrient cycling, flora and fauna habitat, and moisture retention (26, 22, and 16%, respectively). Changes within the valley were lowest, averaging − 3% for flora and fauna habitat and − 13% for organic matter and nutrient cycling. We conclude that the minimum data set (MDS) used provided a representative assessment of soil quality and could serve as a basis for assessment in similar tropical watersheds.     

Neuropharmacological effects of deltamethrin in rats

This study examined the effect of deltamethrin on some of the neuropharmacological paradigms in a rat brain such as the motor co-ordination test using a rotarod, the pentobarbitone-induced sleeping time and pentylenetetrazole (PTZ)-induced convulsion as well as the gamma aminobutyric acid (GABA) level. Albino Wistar rats were used as the experimental animals. Different neuropharmacological paradigms such as the motor co-ordination by the rotarod, pentobarbitone-induced sleeping time and the PTZ-induced convulsion were examined after administering deltamethrin orally at two doses, 150 mg/kg (LD₅₀) and 15 mg/kg (1/10 LD₅₀). The GABA level in the rat brain was estimated by HPLC after a single oral dose of 150mg/kg deltamethrin. Deltamethrin significantly reduced the motor coordination, decreased the onset time and increased the sleeping time duration induced by pentobarbitone. In addition, it also decreased the onset time and increased the duration of convulsions induced by PTZ at 150 mg/kg (LD₅₀) and 15 mg/kg (1/10 LD₅₀), respectively. Further deltamethrin administration decreased the GABA levels in the cerebellum as well as in the whole brain (except the cerebellum) significantly at the LD₅₀ dose level. There was some correlation between the effect of deltamethrin on the central GABA levels and its neuropharmacological effects.     

Imperfect institutional innovation for irrigation management in Bangladesh

This paper discusses the nature and consequences of institutional innovation being pursued in recent years for the organization and management of minor irrigation in Bangladesh. The comparative analysis presented in this paper suggests that there are no significant variations of performance between the mainstream management institutions, except that tubewells under BRDB-Cooperative groups performed less well than others, nor are there any significant associations between major technical factors and irrigation performance (other than nominal pump capacity). What appears to be more important is that the economic institutions such as payment system for water is strongly associated with productivity and equity performance; sharecropping with water, which has emerged, or been popularized, with the privatization programme, has negative impact on productivity and skews benefits of irrigation towards pump owners and managers. It is concluded that so far imperfectly designed institutions, for example privatization of equipment, appear to have failed to give rise to greater technical and allocative efficiency or equity.Abbreviations BADC Bangladesh Agricultural Development Corporation - BRDB Bangladesh Rural Development Board - BKB Bangladesh Krishi (Agricultural) Bank - GB Grameen (Rural) Bank - CARE Cooperative for American Relief Everywhere - KSS Farmers' Cooperative Society - IMP Irrigation Management Programme     

Underutilized and unexploited fruits of Indo-Burma hot spot,Meghalaya, north-east India: ethno-medicinal evaluation,socio-economic importance and conservation strategies

An attempt has been made during 2012–2014 at to enumerate the ethno-medicinal evaluation and socio-economic importance of underutilized and unexploited fruits among the Garo tribe of west Garo hills district, Meghalaya, north-east India. The study was based on extensive field surveys, sample collection and interviews with the traditional healers as well as old aged men and women and survey in rural markets regarding their market demand, price and season of availability. Altogether 66 underutilized and unexploited fruits belonging to 34 families have been enumerated in this paper. The documented fruits were mostly used by the rural people to cure a number of ailments. In addition, these fruits also have socio-economic importance in the rural life of the tribal people like use as constructional timbers, firewood, charcoal, fodder, making dye, yielding oil and a number of value added products. Although, these fruits play an important role in the social and cultural life of Garo people, but these valuable species have been vanishing at very faster rate due to lack of proper documentation. Therefore, the claimed therapeutic values of these species are to be critically studied to establish their safety and effectiveness and both in situ and ex situ conservation measures should be immediately undertaken to safeguard the valuable indigenous rural resources of the world.     

Effect of potassium application on the transformation of zinc fractions in soil and on the zinc nutrition of wetland rice

The effect of different levels of K application on the transformation of native as well as applied Zn fractions in a rice-growing soil was studied under two moisture regimes viz. waterlogged and alternate waterlogged and saturation. Application of K caused an increase in the water-soluble plus exchangeable, organically complexed and carbonates, and other acid-soluble mineral fractions of native soil Zn. Application of K also caused an increase in the transformation of applied Zn into all the above three fractions of the element in soil. The above effects of K were more pronounced in soil under waterlogged than under alternate waterlogged and non-waterlogged moisture regimes. The results of a greenhouse experiment showed that K application caused an increase in Zn uptake and per cent utilization of both native and added Zn by rice. This was attributed to the increase in the water-soluble plus exchangeable and organically complexed forms of Zn in soil due to K application.