On the concept of virtual states

The technique of the decomposed Feynman propagator is used to establish the equivalence between the Feynman and field theoretic formalisms. It is shown that for an nth order process, each of the 2n−1 decomposed Feynman diagrams is equivalent to a certain group in the n! field theoretic diagrams. This is demonstrated for the fourth order Compton scattering of an electron by identifying the energy denominators in the two formalisms

Plant growth promoting bacteria from cow dung based biodynamic preparations

Not AvailableIndigenous formulations based on cow dung fermentation are commonly used in organic farming. Three biodynamic preparations viz., Panchagavya (PG), BD500 and ‘Cow pat pit’ (CPP) showed high counts of lactobacilli (109 ml-1) and yeasts (104 ml-1). Actinomycetes werepresent only in CPP (104 ml-1) and absent in the other two. Seven bacterial isolates from these ferments were identified by a polyphasic approach: Bacillus safensis (PG1), Bacillus cereus (PG2, PG4 PG5), Bacillus subtilis (BD2) Lysinibacillus xylanilyticus (BD3) and Bacillus licheniformis (CPP1). This is the first report of L. xylanilyticus and B. licheniformis in biodynamic preparations. Only three carbon sources—dextrose, sucrose and trehalose out of 21 tested were utilized by all the bacteria. None could utilizearabinose, dulcitol, galactose, inositol, inulin, melibiose,raffinose, rhamnose and sorbitol. All the strains producedindole acetic acid (1.8–3.7 lg ml-1 culture filtrate) and ammonia. None could fix nitrogen; but all except B. safensis and B. licheniformis could solubilize phosphorous from insoluble tri-calcium phosphate. All the strains except L. xylaniliticus exhibited antagonism to the plant pathogen Rhizoctonia bataticola whereas none could inhibit Sclerotium rolfsi. In green house experiment in soil microcosms, bacterial inoculation significantly promoted growth of maize; plant dry weight increased by *21 % due to inoculation with B. cereus (PG2). Results provide a basis forunderstanding the beneficial effects of biodynamic preparations and industrial deployment of the strainsNot Availabl

Media Comparison for Enumeration of Actinobacteria and their Catabolic Diversity in the Crop Rhizosphere of Arid, Semi-Arid and Humid Regions (AER 3 and AER 6) of India

Not AvailableRhizosphere soils of sorghum, pearl millet, pigeon pea, finger millet and groundnut from sub-tropical arid and semi-arid regions (Karnataka, Andhra Pradesh and Rajasthan) and from humid pristine forest soils of Karnataka were used to enumerate actinobacterial populations and their catabolic diversity. The pH of the soils ranged from 5.7 to 9.1 and organic carbon content from 0.075 to 4.3%. Of five different cultural media used, Humic acid vitamin agar was found to be superior for enumeration of Actinobacteria. Forty one (41) Actinobacterial isolates were characterised for morphological and biochemical attributes and tentatively assigned to four genera - Streptomyces (26 no.), Nocardia (12), Micromonospora (1) and Saccharopolyspora (2). The catabolic diversity of Actinobacterial isolates (21 carbon compounds) showed that Shannon-Weaver diversity index (H) was high (3.54). Dendrogram of Actinobacterial isolates showed some degree of catabolic relatedness among arid and semi-arid zone isolates. All the isolates had 18% similarity. At 66% level of similarity there were 18 clusters and this diversity in carbon utilization was much more in the alkaline arid and semi-arid soils (2.81) than in the acidic humid soils (1.94). The species evenness in humid zone isolates (1.00) was slightly higher to that of arid and semi-arid zone (0.993) isolates. The results show that arid and semi-arid regions represent extremely rich reservoir for the isolation of a significant diversity of Actinobacteria and that Humic acid- Vitamin agar is best for recovering greater numbers and diversity.Not Availabl

Actinobacteria of Arid and Semi-arid Soils: Antagonism to Fungal Pathogens and Plant Growth Promoting Potential

Biological control of plant pathogens is assuming increasing importance in organic and low input sustainable agriculture. Forty one Actinobacterial strains isolated from the arid, semi arid and humid regions of Rajasthan, Karnataka, Andhra Pradesh in India were tested for their antagonism to four plant pathogenic fungi viz., Macrophomina phaseolina, Sclerotium rolfsii, Rhizoctonia solani and Fusarium oxysporum. The Streptomyces strains from humid regions were more effective in inhibiting mycelial growth of Macrophomina phaseolina (62.8%). Arid and semi arid region strains (40.8 and 40.6%) were almost similar in inhibiting mycelial growth of Sclerotium rolfsii compared to humid region strains. Semi arid region strains (24.2%) were more effective in inhibiting the mycelial growth of Rhizoctonia solani followed by arid and humid region strains. However only the arid region strains (44.5%) showed inhibition towards Fusarium oxysporum. The strains with best antogonistic ability (10 no.s) also exhibited other plant growth promoting traits like production of Indole acetic acid (1.9 - 5.7 mg ml-1) and Gibberellic acid (24.1-41.4 mg ml-1). All the strains except Streptomyces A30 could solubilize P from inorganic tri-calcium phosphate. The amount of P solubilization ranged from 3.2 - 6.8%. All the strains except Streptomyces A40 produced alkaline phosphatase which ranged from 60.0-160.9 µg p-nitrophenol/ml /h. Some strains produced ammonia whereas none of the strains produced HCN, siderophore or exhibited chitinase activity. In a glass house evaluation in soil microcosms, among the ten strains Streptomyces A6 was found best for promoting maize and Streptomyces A17 for chickpea growth

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Why fertility is low in Tamil Nadu : some plausible explanations using focus group discussion

Meeting: Workshop on Demographic Tranisition in Tamil Nadu, 21-23 Aug. 1995, Madras, INPage 82 missin