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Barddhamān, India

Mukherjee D.,Vivekananda College
Nonlinear Analysis: Real World Applications | Year: 2016

This paper considers the effect of immigration and refuge on the dynamics of a three species system in which one predator feeds on one of two competing species. Immigration is assumed only for the species which is not attacked by the predator. The main results address the stability of the system. Namely, it is shown that increasing the number of refuges stabilizes the system, whereas the opposite holds true by increasing the immigration rate. Also, one result about the persistence of the system and one concerning the global stability of the coexistence equilibrium are presented. Some numerical simulations illustrate the obtained results. © 2016 Elsevier Ltd. All rights reserved.


Amutha S.,Vivekananda College
International Journal of Pharma and Bio Sciences | Year: 2014

Lantana camara Linn is an important weed with a vast array of medicinal uses. In this study, antimicrobial activities of methanol, chloroform, acetone, petroleum ether and hexane extracts of L. camara seed was investigated by using Agar Well Diffusion Method. This activity was tested against four human pathogenic bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris and Escherichia coli. The extracts were used in three different concentrations (75,150 and 250 ug/ml). Among the extracts, methanolic extract of Lantana camara seed showed maximum inhibition against S. aureus, P.aeruginosa and E. coli and no inhibitory against P. vulgaris. Similarly the acetone extracts of L.camara seed also found to have enormous inhibition against S.aureus, P. vulgaris and lesser activity E. coli.. On the other hand, the other extract of chloroform proved to have no antibacterial activity against the bacterial strains used in this study. The result of phytochemical analysis exposes the presence of saponin, reducing sugar, steroids and flavonoids in the seed extract of Lantana camara.


Amutha S.,Vivekananda College
International Journal of Pharma and Bio Sciences | Year: 2014

Antimicrobial efficiency of Solanum melongena seed extracts was examined using methanol, chloroform, acetone and petroleum ether, as solvents and tested against four human pathogenic bacteria such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Proteus vulgaris using Agar Well Diffusion Method. The phytochemical analysis of Solanum melongena seed was also made. The methanolic and acetone extract of Solanum melongena seed showed maximum inhibition against Staphylococcus aureus at all concentrations (75, 150 and 250 ug/ml) significant inhibition was proved at the higher concentration of petroleum ether extract while no inhibition was shown in the chloroform extract of Solanum melongena seed at any level of concentration against Staphylococcus aureus. The methanol extract of the Solonum melongena extract showed enormous inhibitory activity at all concentrations against Escherichia coli while the acetone and petroleum ether extracts of the same plant seed showed significant activity only at the higher concentration against Escherichia coli. The result of phytochemical analysis shows the presensce of reducing sugar, steroid, terpenoid and flavonoid in the seed extract of Solanum melongena.


Mukherjee D.,Vivekananda College
Differential Equations and Dynamical Systems | Year: 2014

A refuge model is developed for a resource-based ecosystem. The predator functional responses are taken to be of Holling type I and II, respectively. Stability analyses are carried out for both the cases. Bifurcation phenomenon occurred only for system with Holling type II predator functional response. We identify the parameter which ensures long-term survival of all the populations. The effects of refuges have been established on equilibrium densities of prey and predator population, respectively. The results show that the effects of refuges used by prey increase the equilibrium density of prey population. As far as the predator population is concerned, when prey density at equilibrium level remains below a certain threshold value, increasing the amount of prey refuge can decrease the predator densities. Numerical examples are provided to support our results. © 2013, Foundation for Scientific Research and Technological Innovation.


Mukherjee D.,Vivekananda College
Differential Equations and Dynamical Systems | Year: 2016

This paper analyzes a prey–predator system where the prey population is infected by a microparasite. The predator functional response is of a Holling type II. We study three cases for the predator food choice. Persistence conditions are derived when predators attack the healthy and infected prey simultaneously. A persistence condition is also derived when predators consume infected prey only. It is shown that when predators attack healthy prey only, then the system cannot be uniformly persistent. The role of delay is also discussed for a system with the predator consuming both types of prey. The parameters are identified which influence the persistence of all the populations as well as impermanence. Numerical examples are provided to support our results. © 2014, Foundation for Scientific Research and Technological Innovation.

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