Toxicological study of plant extracts on termite and laboratory animals

Toxic activity of leaf extracts of Polygonum hydropiper L. and Pogostemon parviflorus Benth. were tested in the laboratory against tea termite, Odontotermes assamensis Holm. Both the tested extracts caused mortality of the termite. The highest toxic activity (100%) was found in the 2.0% chloroform extracts of P. hydropiper. The chloroform extract of P. hydropiper was explored for possible mammalian toxicological effects. The LD50 was 758.58 mg/kg in male albino mice. Subcutaneous injection of sub-lethal dose of extract into male mice once a week for 6 weeks failed to express any significant influence on WBC, RBC count and blood cholesterol.     

Variations in seasonal phytoplankton assemblages as a response to environmental changes in the surface waters of a hypo saline coastal station along the Bhagirathi�CHooghly estuary

Due to the close proximity of the Bay of Bengal and the freshwater inflow of Bhagirathi-Hooghly, Diamond Harbour appeared as an important coastal station of the Bhagirathi-Hooghly estuary. The spatial and temporal composition and abundance of microphytoplankton species was examined in relation to physical and chemical surface water variables (i.e., salinity, nutrient, and temperature).The primary objective of the study was to observe the variations in phytoplankton species assemblages as a response to environmental variables. Hierarchical cluster analysis and non-metric multidimensional scaling were used to find out distinct seasonal groups based on the composition of phytoplankton. The results indicate that several key environmental factors like temperature, DIN content, and molar ratio of nutrients like DIN-DIP and DIN-DSi influenced seasonal phytoplankton assemblages within the estuary. The distribution of phytoplankton population showed two main groups where the blue-green and green algal populations favored the warmer conditions of summer and monsoon months, whereas the diatom population primarily flourished in the cooler months of autumn and winter.     

A study on the phytotoxicity of nano mullite and metal-amended nano mullite on mung bean plants

The presence of engineered nanoparticles is continuously increasing in our environment and causing potential risks to the ecosystem. Researchers from various fields report many articles on the effects of different nanoparticles on plants, animals and microorganisms. Here we have studied for the first time the effect of nano mullite (NMu) and their metal- amended derivatives on the growth of mung bean plants. Results shows that the metal- amended NMu exerts adverse effects on the growth and biomass production of plants compared to NMu. For toxicity studies, we measured the germination index and relative root elongation, while leakage of electrolytes and root oxidizability were measured to study the effect of NMu on mung bean seeds and seedling tissues. Translocation and accumulation of NMu within different parts of the plant body were proved by elemental analysis of dried plant samples.     

A semi-coupled model for determining the distribution of two-dimensional coherent structures in open channel flow

Environmental Fluid Mechanics - Mixing layers and associated large-scale turbulent structures are some of the most common features of turbulent shallow water flow. Due to their...