Stability, effective insulation and heat loss of a salt-gradient solar pond

A relation between salt gradient Gc and temperature gradient GT is derived. Heat losses are estimated for a natural solar pond in a steady state and a thickness of insulating material to achieve the required insulation is suggested. Enlargement of the non-convecting zone in an unsteady state is also discussed. Predicted values are compared with the reported results and good agreement is found.

Integrated crop management strategy for improved chickpea production and its impact on the livelihoods of farmers in Nepal

Chickpea (Cicer arietinum L.) is traditionally an integral component of the rainfed rice-based cropping system of the Terai region of Nepal. However, in the last 20 years frequent crop failures due to out breaks of wilt (Fusarium oxysporum f.sp. ciceris), botrytis gray mold (Botrytis cinerea) and pod borer (Helicoverpa armigera) have made its cultivation unreliable and uneconomical. Surveys have shown that there is a substantial area of rainfed rice-fallow that could grow chickpea and generate additional income if farmers had access to a reliable production system for chickpea. To meet this need an integrated crop management (ICM) technology package was developed for Nepal. This comprised an improved cultivar Avarodhi (ICC 14344), rhizobial and fungicidal treatment of seeds prior to sowing; fertilizer application and need-based foliar applications of fungicides and insecticides to control BGM and pod borer, respectively. This technology package was evaluated and up-scaled through farmers' participatory on-farm research. Over 3000 farmers in 17 villages from 10 districts in the Terai (lowlands) of Nepal participated in conducting ICM validation trials. Severities of wilt, BGM and pod borer were significantly reduced and grain yields more than doubled in ICM plots compared with non-ICM plots in all the five years of study generating a substantial increase in income

Lack of evidence in vivo for nitrergic inhibition by Escherichia coli (STa) enterotoxin of fluid absorption from rat proximal jejunum

Fluid absorption from the proximal jejunum of the anaesthetised rat was measured in vivo by fluid recovery. As expected, heat stable (STa) enterotoxin from E. coli reduced fluid absorption. Neither intraperitoneal L-NAME, thought to inhibit a putative neurally mediated action of STa, nor similar doses of D-NAME, ameliorated the inhibitory effect on jejunal fluid absorption of STa. Luminally perfused 10 mM sodium nitroprusside (SNP) had no effect on fluid absorption when expressed per gram dry weight per hour but reduced fluid absorption when expressed per cm length per hour. Similarly, 80 but not 40 mg/Kg of L-NAME reduced fluid absorption when expressed per cm length per hour, while the same dose of D-NAME did not. L-NAME and SNP significantly increased the wet weight to dry weight and the length to dry weight ratio of perfused loops. We conjecture that smooth muscle relaxation caused by these compounds increases interstitial fluid volumes that can be misconstrued as changes in absorption when this is expressed per cm length or per tissue wet weight. When fluid absorption is expressed per gram dry weight of tissue, there is no evidence for a role of nitric oxide in normal or STa inhibited fluid absorption