Analysis of water, plankton, fish and sediment reveals that the Cauvery River water in the downstream is contaminated by certain heavy metals. Water samples have high carbonate hardness. Concentrations of all elements and ions increase in the downstream. Main ions are in the following order: Na > HCO3>Mg > K > Ca> Cl > SO4. Heavy metal concentration in water was Cr >Cu ≈ Mn > Co > Ni > Pb > Zn, in fish muscles Cr > Mn > Cu > Ni > Co > Pb ≈ Zn, in phytoplanktens Co > Zn > Pb > Mn > Cr and in the sediments the heavy metal concentration was Co > Cr > Ni ≈ Cu > Mn > Zn > Pb. Although, the quality of Cauvery River may be classified as very good based on the salt and sodium for irrigation, Zn, Pb and Cr concentration exceeded the upper limit of standards. Metal concentrations in the downstream indicate an increase in the pollution load due to movement of fertilizers, agricultural ashes, industrial effluents and anthropogenic wastes. An immediate attention from the concerned authorities is required in order to protect the river from further pollution.

The gram-negative soil bacteria Rhizobium spp. infect and establish a nitrogen-fixing symbiosis with legume crops which involves the mutual exchange of diffusable signal molecules. In this study, Rhizobium leguminosarum containing a nod-lacZ gene fusion was used to screen the most effective plant-to-bacteria signal molecules for pea and lentil and the induction conditions. Out of a number of signal compounds including apigenin, daidzein, genistein, hesperetin, kaempferol, luteolin, naringenin, and rutin, hesperetin and naringenin were found to be the most effective plant-to-bacteria signal molecules. The induction of nod genes was temperature-dependent, where nod gene induction was decreased with dropping incubation temperature. The combination of hesperetin at 7 microM and naringenin at 3 microM resulted in better induction of nod gene activities compared to either hesperetin or naringenin alone. Nodulation and plant dry matter accumulation of pea and lentil plants receiving preinduced R. leguminosarum were higher than those of plants receiving uninduced R. leguminosarum cells in controlled environment growth chamber conditions. Preinduced Rhizobium with hesperetin at a concentration of 10 microM increased nodule number on average by 60.5% and dry matter accumulation by 14% in field pea at 17 degrees C, while it was 32% and 9% at 24 degrees C, respectively. Similarly, averaged over two rhizobial strains, a 59% and 6% increase in nodule number and biomass production at 17 degrees C, and a 39% and 27% at 24 degrees C, were obtained from lentil inoculated with hesperetin-induced R. leguminosarum, respectively.

Assessment of heavy metal content in litchens and soil samples from various localities of Hosur Road, Bangalore south was undertaken. Topsoil samples (0-10 cm) were taken at various locations, the metals analysed were Cr, Pb, Fe, Zn, Ni and Cu. The geoaccumulation index of these metals in the soils under study residential areas indicated that they are uncontaminated with Ni, Zn, and Fe and moderately contaminated with Cr and Pb. In Industrial areas and traffic junctions the concentration of Fe, Pb and Ni was maximum. Heavy metal accumulation in few prominent lichens of some localities was analysed. Cr and Pb were maximum inChrysothrix candelaris(L.) Laundon, at the gardens of Madiwala and Silk Board junction with 95.29 and 623.95 µg g–1dry weight respectively. Fe and Cu were maximum inBulbothrix isidiza(Nyl.). Hale andPyxine petricolaNyl at Central Prison campus and Kendriya Sadan campus with 22721 and 338.12 µg g–1dry weight respectively,Lecanora perplexaBrodo at Infosis and Wipro Campus, electronic city have 531.5 and 634 µg g–1dry weight of Zn. While Ni and Fe were maximum in Arthopyreniaceae at Shanti Niketan of MICO Limited with 1100 and 23200 µg g–1dry weight respectively.

The quality of water in four streams of Cauvery River in Mandya District, where many small scale sugar and brewery distilleries are located, was analysed. Sampling was carried out from four streams designated as station 1 (upstream of effluent discharge point), station 2 (effluent discharge point) and station 3 (downstream of effluent discharge) station 4 (fresh water stream) to assess the impact of effluent on the water quality. The river water composition is increasingly dominated by Na and Cl in the downstream region of the river, indicating the influence of airborne salts with oceanic affinities. Significant spatial variation was observed in water level, transparency, turbidity, depth, dissolved oxygen, colour, biochemical oxygen demand, nitrate, nitrite and total hydrocarbon among the physiochemical parameters of the study stations.

The development of polymer-based nanoparticulate delivery systems for siRNA is important for the clinical success of gene therapy. However, there are some major drawbacks that need to be overcome. Short interfering RNA (siRNA) has been investigated as a potential therapeutic drug to silence disease-associated genes, but its usage is limited due to the lack of effective and safe nanocarriers. In this study, DOPE-PEI, a nanoparticle consisting of the fusogenic lipid 1,2dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) conjugated with low-molecular-weight, 600 Da, branched polyethylenimine (PEI) was produced and optimized for siRNA delivery. This delivery system was modified with other components such as 1,2-dioleoyl-sn-glycerol-3phosphoethanolamine-N-[methoxy(polyethyleneglycol)2000] (DOPE-PEG2K), DOPE-PEG3.4K-bombesin and 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine/1,2-dioleoyl-3trimethylammonium-propane (DOPE/DOTAP) and tested on PC-3 cells. The conjugation of DOPE to PEI polymer (DOPE-PEI) improved the efficiency of PEI to deliver siRNA into the cytosol and knockdown genes, but demonstrated high toxicity. The addition of DOPE-PEG2K reduced cellular toxicity by masking the surface positive charge of the DOPE-PEI/siRNA complex, with the incorporation of a gastrin-releasing peptide receptor (GRPR) targeting peptide and DOPE/DOTAP components improving the cellular uptake of siRNA into targeted cells and the siRNA knockdown efficiency.