NOPR Collection:

Predation and searching efficiency of a ladybird beetle, Coccinella septempunctata Linnaeus in laboratory environment

2003-01-01T00:00:00Z

Title: Predation and searching efficiency of a ladybird beetle, Coccinella septempunctata Linnaeus in laboratory environment Authors: Omkar; Srivastava, Shefali Abstract: The predation and searching efficiency of fourth instar of predatory C. septempunctata at various densities of mustard aphid, Lipaphis erysimi (Kaltenbach) and predator was investigated under laboratory conditions. The feeding rate of predatory stage decreased at increased prey- and predator densities. Highest percent (92.80%) prey consumption was observed at initial prey density and lowest percent (40.86%) prey consumption at highest prey density by the fourth instar, though the total prey consumption increased with increase in either prey- or predator densities. Similarly, the individual prey consumption was also highest at initial predator density and lowest at highest predator density owing to the mutual interference between the predators at higher densities. The area of discovery (searching efficiency) also decreased with increase in preyand predator densities. Handling time of predator was highest at lower prey densities, which decreased with increased prey densities. The highest percentage of prey consumption at the prey density of 50 revealed that 1:50 predator-prey ratio was the best to reduce the pest population. Page(s): 82-84

Effect of oophorectomy on expression of calcium sensing receptor mRNA in rat duodenal mucosa

2003-01-01T00:00:00Z

Title: Effect of oophorectomy on expression of calcium sensing receptor mRNA in rat duodenal mucosa Authors: Mehrotra, M; Gupta, S K; Tiwari, S; Agarwal, A; Kumar, K; Awasthi, P K; Godbole, M M Abstract: Calcium sensing receptor (CaR) in duodenal mucosa may be involved in active calcium absorption. Estrogen deficiency results in decreased intestinal calcium absorption. Effects of bilateral oophorectomy (OVX) have been studied on calcium homeostasis, bone mineral density (BMD) and CaR mRNA levels in duodenal mucosa at 4 weeks in adult female Sprague Dawley rats and compared with those in sham-operated and control group. There was no significant change in serum corrected calcium, inorganic phophorous, calcidiol and intact parathyroid hormone in all the three groups. OVX rats had a significant decline in serum estrogen (E₂) levels and alkaline phosphatase. They also had a significant decrease in BMD (DXA) at lumbar spine in vivo, and proximal and d istal tibia in vitro while there was no significant change in serum E₂and BMD parameters in sham-operated and control rats. Northern blot analysis revealed no significant change in the CaR mRNA expression in duodenal mucosa in all three groups. The results suggests that CaR mRNA expression in duodenal mucosa is not affected by physiological circulating concentrations of estradiol in rats. Page(s): 41-46

Effect of phenol on ultra structure and plasmid DNA of Xanthomonas oryzae pv. oryzae

2003-01-01T00:00:00Z

Title: Effect of phenol on ultra structure and plasmid DNA of Xanthomonas oryzae pv. oryzae Authors: Mohan, N; Mahadevan, A Abstract: Most phenolic substances of plant origin are toxic to microorganisms and they confer some degree of protection to plants against phytopathogens. Xanthomonas oryzae pv. oryzae, bacterial blight pathogen of rice (Oryza sativa) was treated with phenol (monohydroxy benzene) and its effects on the morphology and cytological changes of the bacterium were studied. Total lysis of cells occurred with 5 mM cone of phenol while at 2 mM cone, the cell walls became rough and cell contents started shrinking. Plasmids isolated from both treated (2 mM) and control cells did not show any marked difference under electron mi croscope except that they differed in their quantity and might influence pathogenicity. Page(s): 78-81

Enhanced esterase activity in salivary gland and midgut of Aedes aegypti mosquito infected with dengue-2 virus

2003-01-01T00:00:00Z

Title: Enhanced esterase activity in salivary gland and midgut of Aedes aegypti mosquito infected with dengue-2 virus Authors: Mourya, D T; Rohankhedkar, M S; Yadav, P; Dighe, V; Deobagkar, D N Abstract: Mosquitoes were infected by intrathoracic inoculation. About 95% head squashes were positive for dengue virus antigen on the 15^th post infection day (PID). Esterase activity was determined in the homogenates prepared from the salivary glands and midguts on different PIDs of dengue virus inoculated and control mosquitoes showed that it was consistently higher in the virus- infected batches. Page(s): 91-93