Revisiting coupled CDM-massive neutrino perturbations in diverse cosmological backgrounds

Massive neutrinos are well-known to cause a characteristic suppression in the growth of structures at scales below the neutrino free-streaming length. A detailed understanding of this suppression is essential in the era of precision cosmology we are entering into, enabling us to better constrain the total neutrino mass and possibly probe (beyond)-$\Lambda$CDM cosmological model(s). Instead of the usual N-body simulation or Boltzmann solver, in this article we consider a two-fluid framework at the linear scales, where the neutrino fluid perturbations are coupled to the CDM (+ baryon) fluid via gravity at redshifts of interest. Treating the neutrino mass fraction $f_\nu$ as a perturbative parameter, we find solutions to the system with redshift-dependent neutrino free-streaming length in $\Lambda$CDM background via two separate approaches. The perturbative scale-dependent solution is shown to be in excellent agreement with numerical solution of the two-fluid equations valid to all orders in $f_{\nu}$, and also agrees with results from {\texttt{CLASS}} to a good accuracy. We further generalize the framework to incorporate different evolving dark energy backgrounds and found sub-percent level differences in the suppression, all of which lie within the observational uncertainty of BOSS-like surveys. We also present a brief discussion on the prospects of the current analysis in the context of upcoming missions.Comment: 20 pages, 6 sets of figures. Major update: An alternate method to perform the perturbative analysis is added. Accepted in JCA

Evaluation of Antifungal and Antibacterial Activities of the Plant Coccinia grandis (L.) Voigt. (Family- Cucurbitaceae)

Coccinia grandis, family-Cucurbitaceae, a perennial tendril climber plant, possessing significant antidiabetic property. Other plants in the family Cucurbitaceae possessing diuretic, aphrodisiac, bitter stomachic, purgative and emetic properties. But antimicrobial activity of C. grandis has not been evaluated extensively. We have paid more importance on antimicrobial activities against various fungal strains and different gram positive and gram negative bacteria. Aqueous and ethanolic extract were used to evaluate antifungal and antibacterial activities. Antifungal activity was observed on Candida albicans and Aspergillus niger and antibacterial activity was observed on gram positive bacteria like Bacillus subtilis UC564, Bacillus pumilus-8241, Enterococcus faecalis ATCC-29212, Bacillus licheniformis, Staphylococcus aureus ATCC6571, Streptococcus  faecalis-52 and gram negative bacteria like Shigella boydii-Type12, Shigella flexneri E03429, Shigella dysenteriae-3 , Pseudomonas aeruginosa , Escherichia coli-K88, Salmonella typhi-62 , Salmonella choleraesuis-36 , Shigella boydii-8, Shigella flexneri NICED, Shigella sonnei E08869.Key words: Coccinia grandis, MIC, antifungal and antibacterial activities Bolay Bhattacharya et al. Evaluation of Antifungal and Antibacterial Activities of the Plant Coccinia grandis (L.) Voigt. (Family- Cucurbitaceae).  J Phytol 2/11 (2010) 52-5

Stability analysis of an eco-epidemiological model incorporating a prey refuge

The present paper deals with the problem of a predator-prey model incorporating a prey refuge with disease in the prey-population. We assume the predator population will prefer only infected population for their diet as those are more vulnerable. Dynamical behaviours such as boundedness, permanence, local and global stabilities are addressed. We have also studied the effect of discrete time delay on the model. The length of delay preserving the stability is also estimated. Computer simulations are carried out to illustrate our analytical findings

Packing of aromatic rings against tryptophan residues in proteins

The geometry of the interaction of the aromatic side chains of phenylalanine (Phe), tyrosine (Tyr), tryptophan (Trp) and histidine (His) with the indole ring of Trp has been analyzed using the structures in the Protein Data Bank in order to understand the dependence of the packing behaviour on the size and chemical nature of the aromatic rings. The Phe ring prefers to interact either perpendicularly, with its edge pointing towards the Trp face, or in an offset-stacked arrangement. The edge-to-face motif is typical of a Trp-Trp pair. While parallel stacking is the dominant feature of Trp-His interaction, Tyr packs in a more uniform manner around Trp with a higher than expected occurrence at the edge and a few cases of possible OH-Π interaction

Assessment of Groundwater Potential Zone in Paschim Medinipur District, West Bengal – A Meso-scale study using GIS and Remote Sensing Approach

The investigation of groundwater in hard rock terrains is a complex task. To overcome this complexity, the integrated approach based on advanced applications of remote sensing and GIS lends itself to evaluate groundwater prospective zone based on multi-criteria evaluation approach (e.g. seasonal land use/land cover and vegetation, hydro-geology, geomorphology, soil, drainage density, monsoon and post monsoon water level and elevation). A probability weightage index overlay method was adopted that allows a linear combination of probability weights of each thematic map with the individual impact value using Bayesian statistics. These capability values are then multiplied with the respective probability weight of each thematic map. The result shows groundwater potentiality of Paschim Medinipur is stretched along the eastern part and in small pockets in northern and southern part. The hydrologic parameters-based groundwater potential zone map also indicated, 8.08% of the study area was classified as having very high potential, 11.99% high potential and 17.72% moderate potential. The groundwater abstractions structures feasible in each of the various potential zones have also been suggested. This study also provides a methodological approach for an evaluation of the water resources in hard rock terrain and enables an opening of the scope for further development and management practices. Keywords: Remote Sensing, GIS, probability weightage index , Groundwater potentialit

Anthelmintic activity of Hygrophila difformis Blume

This study evaluated the anthelmintic activity of the petroleum ether, benzene, chloroform, ethanol extracts of aerial parts of Hygrophila difformis (Family: Acanthaceae).  The Pheretima posthuma were used for all the experimental protocol due to their anatomical and physiological resemblance with the intestinal roundworms of human beings and other ruminants. The worms were treated with the extract solutions containing three different concentrations (10, 25 and 30 mg/ml), for each extracts supplemented with 1% gum acacia in normal saline at 37 ± 1°C. Albendazole at a dose of 10 mg/ml was used as reference. The effectiveness of the extracts was judged on the basis of the loss of spontaneous movement and/or death of the worms. Qualitative phytochemical analysis of different extracts of the plant was carried out following the standard procedure. All extracts at different dose levels effectively paralyzed and killed the worm in dose-dependent fashion (***p < 0.001). Maximum anthelmintic activity was found with benzene extract. Cardiac glycosides, tannins, steroids, flavonoids and saponins were found positive in phytochemical analysis. The present study established the anthelmintic activity of H. difformis and can be utilized for the ruminants

Stability and Bifurcation Analysis of a Delayed Three Species Food Chain Model with Crowley-Martin Response Function

In this paper we have studied the dynamical behaviors of three species prey-predator system. The interaction between prey and middle-predator is Crowley-Martin type functional response. Positivity and boundedness of the system are discussed. Stability analysis of the equilibrium points is presented. Permanence and Hopf-bifurcation of the system are analyzed under some conditions. The effect of discrete time-delay is studied, where the delay may be regarded as the gestation period of the super-predator. The direction and the stability criteria of the bifurcating periodic solutions are determined with the help of the normal form theory and the center manifold theorem. Extensive numerical simulations are carried out to validate our analytical findings. Implications of our analytical and numerical findings are discussed critically