Classical Langevin dynamics of a charged particle moving on a sphere and diamagnetism: A surprise

It is generally known that the orbital diamagnetism of a classical system of charged particles in thermal equilibrium is identically zero -- the Bohr-van Leeuwen theorem. Physically, this null result derives from the exact cancellation of the orbital diamagnetic moment associated with the complete cyclotron orbits of the charged particles by the paramagnetic moment subtended by the incomplete orbits skipping the boundary in the opposite sense. Motivated by this crucial, but subtle role of the boundary, we have simulated here the case of a finite but \emph{unbounded} system, namely that of a charged particle moving on the surface of a sphere in the presence of an externally applied uniform magnetic field. Following a real space-time approach based on the classical Langevin equation, we have computed the orbital magnetic moment which now indeed turns out to be non-zero, and has the diamagnetic sign. To the best of our knowledge, this is the first report of the possibility of finite classical diamagnetism in principle, and it is due to the avoided cancellation.Comment: Accepted for publication in EP

Can re-entrance be observed in force induced transitions?

A large conformational change in the reaction co-ordinate and the role of the solvent in the formation of base-pairing are combined to settle a long standing issue {\it i.e.} prediction of re-entrance in the force induced transition of DNA. A direct way to observe the re-entrance, i.e a strand goes to the closed state from the open state and again to the open state with temperature, appears difficult to be achieved in the laboratory. An experimental protocol (in direct way) in the constant force ensemble is being proposed for the first time that will enable the observation of the re-entrance behavior in the force-temperature plane. Our exact results for small oligonucleotide that forms a hairpin structure provide the evidence that re-entrance can be observed.Comment: 12 pages and 5 figures (RevTex4). Accepted in Europhys Lett. (2009

Isolation and Screening of Azo Dyes Tolerant Bacteria in Semi-Scale Industrial Effluents

Dyes are organic compound have colouring properties of the object which used in industrial application. Huge effluent are releasing by industrial processing, where the microorganism may naturally adopted against particular problems. Present work focused over the selection and screening few best native candidates from diverse bacteria from semi-skilled dye industrial effluent. From eleven isolated bacterial colonies only two are found resistant against azo dyes (Methyl orange and Trypan blue). During the screening it observed that isolates of bacteria (VN1 and VN2) were tolerates and decolorize azo dye up to 500 ppm. These bacterial strain can be used efficientlyremoval of dyes contamina-tion from ex-situ and in-situ

GIS-based air pollution distribution mapping of emissions from public buses for Coimbatore Corporation, Tamil Nadu, India

947-951Vehicle transport on roads is a dominant source of air pollution, and hence spatial assessment of its risks is necessary for the decision makers to evaluate its impact on the public. Indian road transport, especially buses, contribute significantly to air pollution, that too in highly accessible areas like bus stands and bus stops. This paper proposes a three-step integrated method to map relative pollution levels of bus stops and bus routes of Coimbatore Corporation using spatial analysis tools of ArcGIS and suggestion of routes for eco-friendly buses and vehicles

Antimicrobial effects of Indian medicinal plants against acne-inducing bacteria

Propionibacterium acnes and Staphylococcus epidermidis have been recognized as pus-forming bacteria triggering an inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Indian medicinal plants against these etiologic agents of acne vulgaris. Ethanolic extracts of Hemidesmus indicus (roots), Eclipta alba (fruits), Coscinium fenestratum (stems), Curcubito pepo (seeds), Tephrosia purpurea (roots), Mentha piperita (leaves), Pongamia pinnata (seeds), Symplocos racemosa (barks), Euphorbia hirta (roots), Tinospora cordyfolia (roots), Thespesia populnea (roots), and Jasminum officinale (flowers) were tested for antimicrobial activities by disc diffusion and broth dilution methods. The results from the disc diffusion method showed that 07 medicinal plants could inhibit the growth of Propionibacterium acnes. Among those Hemidesmus indicus, Coscinium fenestratum, Tephrosia purpurea, Euphorbia hirta, Symplocos racemosa, Curcubito pepo and Eclipta alba had strong inhibitory effects. Based on a broth dilution method, the Coscinium fenestratum extract had the greatest antimicrobial effect. The MIC values were the same (0.049 mg/ml) for both bacterial species and the MBC values were 0.049 and 0.165 mg/ml against Propionibacterium acnes and Staphylococcus epidermidis, respectively. In bioautography assay, the Coscinium fenestratum extract produced strong inhibition zones against Propionibacterium acnes. Phytochemical screening of Coscinium fenestratum revealed the presence of alkaloid which could be responsible for activity. Taken together, our data indicated that Coscinium fenestratum had a strong inhibitory effect on Propionibacterium acnes and Staphylococcus epidermidis. . Keywords: Acne; Propionibacterium acnes; Staphylococcus epidermidis; Antimicrobial activity > Tropical Journal of Pharmaceutical Research Vol. 6 (2) 2007: pp. 717-72