Cross-Infectivity of Ralstonia solanacearum from Marigold Grown in Andaman Islands

Bacterial wilt disease, caused by Ralstonia solanacearum, is one of the major concerns for marigold cultivation in Andaman Islands. Cross-infectivity potential of the bacterial wilt pathogen, isolated from marigold, was tested in other common vegetable-hosts of the Island. Pathogen identity was confirmed by morphological identification and Biolog based phenotypic fingerprinting. Cross-infectivity tests revealed tomato to be the most susceptible among the three solanaceous hosts tested. Highest wilt incidence was observed in tomato and marigold (100%) plants, followed by 55.6% in brinjal and 22.3% in chilli, upon artificial soil inoculation. Our study enlightens pathogenic potential of the bacterial wilt pathogen in important vegetable crops of Andaman Islands and can help formulate suitable management practices for successful management of the pathogen

Lasing without inversion in the absence of a coherent coupling field

We analyze the inversionless gain in a three-level ladder system by replacing the usual coherent coupling field with an incoherent field. Surprisingly, it is found that one can obtain inversionless amplification of a weak probe even in the absence of a coherent field in the model. We conclude that gain is determined by the ensemble average of the product of the two-photon coherence and the "effective Rabi frequency" of the field. Thus, even though the incoherent pump reduces the two-photon coherence, gain can be restored by choosing sufficiently high strengths of the incoherent field

SPECTRAL AND BIOLOGICAL EVALUATION OF SOME ORGANORUTHENIUM COMPLEXES LIGATED WITH SECONDARY THIOMIDE

ABSTRACT ] (where, HL = 1-paraethoxy phenyl tetrazoline-5-thione, E = P/As; X = Cl/Br) has been described. The heterocyclic thioamide ligand behaves as monoanionic N,S -chelating bidentate ligand. The structure of complexes have been deduced by elemental analysis, conductivity, magnetic and spectral (IR, electronic and 1 H NMR) analysis. The in vitro antimicrobial activity of the investigated compounds was tested against the bacteria such as S. aureus, B. subtilis and E. coli and fungi A. Flacus, A. Parasiticus and C. Albicans. The data reveal that all complexes are more active than free ligand molecule

Nitramine Double Base Propellants

This review paper broadly covers the studies conducted on nitramine double base (DB) propellants, particularly in the field of formulations, evaluation, catalysis and combustion mechanism . Addition of RDX and HMX in double base matrix shows relatively low burn rates and high paper index values. Further, the burn rate of this class of propellants enhances in the presence of energetic binders/plasticisers like glycidyl azide polymer. This paper also discusses the combustion mechanism of HMX/RDX-based DB propellants, especially in the presence of catalytic salts. As scanty data is available on extruded nitramine DB propellants, further work is needed in the field of formulation as well as evaluation with a view to generate exhaustive data

Use of Tetra-ammonium Tetrakis(4-Sulphonato)Phenyl Porphyrin for Pseudomonas and Bacillus Cell Imaging

The use of tetraammonium tetrakis(4-sulphonato)phenyl porphyrin (TPPS), a water-soluble anionic compound, as a stain to analyse bacterial cells using fluorescent microscopy was investigated. TPPS was effectively used to analyse two different bacteria: Pseudomonas aeruginosa and Bacillus cereus. The variation in brightness with varying concentrations of TPPS was studied. The patterns of variations for these bacteria were found to be the same, but with consistently higher brightness for Bacillus cereus

Characterization of Degree of Eco-restoration by Tree-Grass Interaction in Degraded Lands of Semi-Arid Tropics

Land degradation majorly declines soil health. Eco-restoration through tree-grass interaction provides a perfect solution to restore degraded lands. The study was carried out at Jhansi district of India during 2010 to 2019 with three fodder trees viz namely, Ficus infectoria, Morus alba, and Acacia nilotica and a shrub Leucaena leucocephala (along with three grasses (Cenchrus ciliaris, Chrysopogon fulvus and Panicum maximum). The main objectives of these study were to a) assess the changes in soil organic carbon pools and responses of soil enzymes as impacted by different eco-restoration strategies involving trees and grasses; and b) develop an index to measure efficiency of eco-restoration strategies to aid the community.Grass and tree biomass yield were the highest for Panicum maximum and Ficus infectoria, respectively.After 9 years, land under Ficus, Morus, and Acacia had ~ 63, 105, and 87% greater total organic carbon and Cenchrus, Panicum, and Chrysopogon increased total organic carbon by 84, 91 and 77% at surface layers, respectively, over fallow land. Microbial biomass C increased by 2-2.5 folds in both soil layers after. There were positive correlation among all the C fractionsand eco-restoration efficiency. Carbon management index (CMI) enhanced by 51, 84, and 70% at surface layers under Ficus, Morus, and Acacia based systems, respectively over fallow land. Similarly, grasses also improved CMI by \u3e60%. Accumulation of soil organic carbon under Ficus, Morus, and Acacia were ~55, 91, and 77 % higher than fallow land at surface layers. By combining CMI and biological activity index, we developed eco-restoration efficiency index and found Morus + Panicum, Acaia + Panicum to be effective restoration strategies for eco-restoration under degraded lands of tropical climates. Our study indicated that implementation of these eco-restoration strategies could be a quantitatively important component of climate change mitigation strategies in India and should be continually paid a great attention

Mesoscale convection system and occurrence of extreme low tropopause temperatures: observations over Asian summer monsoon region

The present study examines the process of how tropospheric air enters the stratosphere, particularly in association with tropical mesoscale convective systems (TMCS) which are considered to be one of the causative mechanisms for the observation of extremely low tropopause temperature over the tropics. The association between the phenomena of convection and the observation of extreme low tropopause temperature events is, therefore, examined over the Asian monsoon region using data from multiple platforms. Satellite observations show that the area of low outgoing long wave radiation (OLR), which is a proxy for the enhanced convection, is embedded with high altitude clouds top temperatures (&le;193 K). A detailed analysis of OLR and 100 hPa temperature shows that both are modulated by westward propagating Rossby waves with a period of ~15 days, indicating a close linkage between them. The process by which the tropospheric air enters the stratosphere may, in turn, be determined by how the areas of convection and low tropopause temperature (LTT) i.e. <I>T</I>&le;191 K are spatially located. In this context, the relative spatial distribution of low OLR and LTT areas is examined. Though, the locations of low OLR and LTT are noticed in the same broad area, the two do not always overlap, except for partial overlap in some cases. When there are multiple low OLR areas, the LTT area generally appears in between the low OLR areas. Implications of these observations are also discussed. The present analysis also shows that the horizontal mean winds have a role in the spatial distribution of low OLR and LTT

Application of polarization ellipse technique for analysis of ULF magnetic fields from two distant stations in Koyna-Warna seismoactive region, West India

A new approach is developed to find the source azimuth of the ultra low frequency (ULF) electromagnetic (EM) signals believed to be emanating from well defined seismic zone. The method is test applied on magnetic data procured from the seismoactive region of Koyna-Warna, known for prolonged reservoir triggered seismicity. Extremely low-noise, high-sensitivity LEMI-30 search coil magnetometers were used to measure simultaneously the vector magnetic field in the frequency range 0.001–32 Hz at two stations, the one located within and another ~100 km away from the seismic active zone. During the observation campaign extending from 15 March to 30 June 2006 two earthquakes (EQs) of magnitude (M&lt;sub&gt;&lt;I&gt;L&lt;/I&gt;&lt;/sub&gt;&amp;gt;4) occurred, which are searched for the presence of precursory EM signals. &lt;br&gt;&lt;br&gt; Comparison of polarization ellipses (PE) parameters formed by the magnetic field components at the measurement stations, in select frequency bands, allows discrimination of seismo-EM signals from the natural background ULF signals of magnetospheric/ionospheric origin. The magnetic field components corresponding to spectral bands dominated by seismo-EM fields define the PE plane which at any instant contains the source of the EM fields. Intersection lines of such defined PE planes for distant observation stations clutter in to the source region. Approximating the magnetic-dipole configuration for the source, the magnetic field components along the intersection lines suggest that azimuth of the EM source align in the NNW-SSE direction. This direction well coincides with the orientation of nodal plane of normal fault plane mechanism for the two largest EQs recorded during the campaign. More significantly the correspondence of this direction with the tectonic controlled trend in local seismicity, it has been surmised that high pressure fluid flow along the fault that facilitate EQs in the region may also be the source mechanism for EM fields by electrokinetic effect