Influences of Dark Energy and dark matter on Gravitational Time Advancement

The effect of dark matter/energy on gravitational time advancement (negative effective time delay) has been investigated considering few dark energy/matter models including cosmological constant. It is found that dark energy gives only (positive) gravitational time delay irrespective of the position of the observer whereas pure Schwarzschild geometry leads to gravitational time advancement when the observer is situated at relatively stronger gravitational field point in the light trajectory. Consequently, there will be no time advancement effect at all at radial distances where gravitational field due to dark energy is stronger than the gravitational field of Schwarzschild geometry.Comment: 7 pages, no figur

Seeking the best practices of assessment in maritime simulator training

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Rotational Variability and Detection of Superflares in a Young Brown Dwarf by TESS

We present a comprehensive analysis of a Transiting Exoplanet Survey Satellite (TESS) high-quality light curve for a young brown dwarf, MHO~4 having spectral type M7.0, in the Taurus star-forming region. We investigate the rotation periods and characterize the BD's dynamic atmosphere and surface features. We present light curve analysis of MHO~4, and estimate the rotation period to be around 2.224~d. Remarkably, MHO~4 exhibits two significant flaring events. Furthermore, we also estimated bolometric flare energies to be within the energy range of $10^{34}$ to $10^{35}$ erg, which sits in the superflare category.Comment: 10 pages, 5 figure

SILVER NANOPARTICLES OF MORINGA OLEIFERA – GREEN SYNTHESIS,CHARACTERISATION AND ITS ANTIMICROBIAL EFFICACY

Abstract : The traditional medicinal plant Moringa oleifera is an integral part of the Indian diet and has notable beneficial effects in its leaves, stems, flowers, roots, bark and seeds. It has reported properties like antimicrobial, anti inflammatory, ant diabetic, anti oxidative, anti tumorogenic amongst many other properties. In the present study we have devised a new green method of synthesis of silver nanoparticles to evaluate its antimicrobial efficacy using the aqueous plant extract as the reductant as well as the stabilizer. A cold method of synthesis of silver nanoparticles using silver nitrate solution is performed. After the synthesis step, the nanoparticles are characterised using UV VIS spectroscopy, scanning electron microscopy and transmission electron microscopy. The results show the incorporation of the silver ions in the extract and also the reduction of the particle size to the nano range. The antimicrobial potential of these nanoparticles synthesized is tested against various gram positive and gram negative strains of bacteria keeping streptomycin as the standard positive control antibiotic. The antibiotic assay is performed using agar well diffusion method and comparable results are obtained in comparison to the standard antibiotic. It is seen that the nanoparticles have good antibacterial efficacy against the tested strains. Hence nanoparticles of Moringa oleifera aqueous extracts can be used as a potential alternative to traditional antibiotics using this non toxic safe way of green synthesis. Keywords: Moringa oleifera, silver nanoparticles, antimicrobia

Comparative transcriptome profiling provides insights into the growth promotion activity of Pseudomonas fluorescens strain SLU99 in tomato and potato plants

The use of biocontrol agents with plant growth-promoting activity has emerged as an approach to support sustainable agriculture. During our field evaluation of potato plants treated with biocontrol rhizobacteria, four bacteria were associated with increased plant height. Using two important solanaceous crop plants, tomato and potato, we carried out a comparative analysis of the growth-promoting activity of the four bacterial strains: Pseudomonas fluorescens SLU99, Serratia plymuthica S412, S. rubidaea AV10, and S. rubidaea EV23. Greenhouse and in vitro experiments showed that P. fluorescens SLU99 promoted plant height, biomass accumulation, and yield of potato and tomato plants, while EV23 promoted growth in potato but not in tomato plants. SLU99 induced the expression of plant hormone-related genes in potato and tomato, especially those involved in maintaining homeostasis of auxin, cytokinin, gibberellic acid and ethylene. Our results reveal potential mechanisms underlying the growth promotion and biocontrol effects of these rhizobacteria and suggest which strains may be best deployed for sustainably improving crop yield

Bioactive Silver Phosphate/Polyindole Nanocomposites

Materials capable of releasing reactive oxygen species (ROS) can display antibacterial and anticancer activity, and may also have anti-oxidant capacity if they suppress intracellular ROS (e.g. nitric oxide, NO) resulting in anti-inflammatory activity. Herein we report silver phosphate (Ag3PO4)/polyindole (Pln) nanocomposites which display antibacterial, anticancer and anti-inflammatory activity, and have therefore potential for a variety of biomedical applications