Assessment of the biological quality of riverine water using pathogenicity islands (PAIs) of coliform bacteria as pollution indicator

The biological methods of quality assessment of water include the determination of harmful biological entities. In this study, quality of water from two riverine study sites was monitored in terms of the most probable number (MPN index) and pathogenicity. MPN index was found to be 0.11 and 0.15/100 mL which was also confirmed by membrane filtration technique (MFT). The isolated pure cultures were subjected to various pathogenicity tests including blood haemolysis and biofilm formation. Out of ten isolates, six showed positive results and these potentially pathogenic isolates were found to be resistant to various antibiotics like erythromycin (E), vancomycin (VA), chloramphenicol (C), tetracyclin (TE), acidoclav (AC) and kanamycin (K). Genetic analysis of these six isolates confirms the presence of flanking regions of virulence cassettes pathogenicity island (PAI) in their genome. Hence, in addition to the MPN test, the pathogenicity tests using the amplification of flanking regions of PAI can be used as a marker for determination of biological quality of water.     

Statefinder description of a cosmological model based on a mixture of five fluids

In this paper, we have considered a model of our universe containing five components as its constituents. Then, we have done here the statefinder diagnostics for this model. This model can successfully explain the accelerated expansion of the universe given that it satisfies a certain condition. Here we have considered the modified Chaplygin gas as the dynamically changing part of the dark energy component of our universe. Chaplygin gas provides early deceleration and late time acceleration of the universe. The graphical representation of statefinder parameters shows that the total evolution of the universe starts from radiation era to phantom model.     

Dynamical behavior of size-graded dust grains levitated in rotating magnetized astroplasmas

Our purpose is to examine the formation of different sheaths in rotating astroplasmas embedded in an ambient magnetic field. Sequel to our recent work (Das and Chakraborty in Astrophys. Space Sci., 2011) we remodeled our present study with the view to finding of robust sheath over the Earth’s Moon along with the formation of dust clouds therein. Based on using the pseudopotential analysis, a modified Sagdeev potential equation has been derived, which, in turns, quantifies the interaction of Coriolis force and magnetic field and to derive the different natures of sheath and dust atmosphere. The application of this result to the input numeric data of the lunar environment and dynamical behaviors of dust levitation has been studied. Our study finds that the dust particles having a spatial segregation within the sheath region form dust clouds in spaces.     

Surface complexation modeling of Cu(II) adsorption on mixtures of hydrous ferric oxide and kaolinite

Background  

The application of surface complexation models (SCMs) to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids.