302 research outputs found

    Stimulation of macromolecular synthesis by ascorbate in Neurospora

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    Stimulation of macromolecular synthesis by ascorbat

    Matter-positronium interaction: An exact diagonalization study of the He atom - positronium system

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    The many-body system comprising a He nucleus, three electrons, and a positron has been studied using the exact diagonalization technique. The purpose has been to clarify to which extent the system can be considered as a distinguishable positronium (Ps) atom interacting with a He atom and, thereby, to pave the way to a practical atomistic modeling of Ps states and annihilation in matter. The maximum value of the distance between the positron and the nucleus is constrained and the Ps atom at different distances from the nucleus is identified from the electron and positron densities, as well as from the electron-positron distance and center-of-mass distributions. The polarization of the Ps atom increases as its distance from the nucleus decreases. A depletion of the He electron density, particularly large at low density values, has been observed. The ortho-Ps pick-off annihilation rate calculated as the overlap of the positron and the free He electron densities has to be corrected for the observed depletion, specially at large pores/voids.Comment: 18 pages, 8 figure

    Role of Silicon in Boron Potassium Nitrate System.

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    To examine the possibility of improving the ignition characteristics of the commonly used pyrotechnic ignition system based on B-KNO/sub -Binder (30:70:10), B was gradually replaced by Si in its composition. The addition of Si was found to reduce the maximum pressure find increase the ignition delay. Maximum dp/dr value was observed with the composition containing 5 per cent Si. The differential thermal analysis results showed single sharp peaks for ignition in the temperature range 500-570 degreeC. The heat of combustion and burning rate decreased with increase in Si content. Impact sensitivity of the compositions increased with increase in the percentage of Si, whereas no change was observed in the friction sensitivity in comparison with the base composition

    Conservation of high Phosphorous high Manganese ores by Sintering of Dephosphorised concentrate

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    The ores of manganese enjoy a high order of import- ance since no quality steel can be produced without the addition of small amounts of manganese. In view of its economic importance it becomes imperative to take stock of the facts about this mineral in a comprehensive manner. According to an IBM estimate, the recoverable rese-rves of manganese ore as on 1-1-1983 are 138.00 million tonnes comprising 18 million tonnes in measured category 32.00 million tonnes in indicated category and 88.00 million tonnes in inferred category

    Sintering characteristics of manganese ore fines from Balaghat and Ukwa mines of Manganese Ore (India) Limited

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    Indian manganese ore reserves are depleting very fast Manganese ore (India) Ltd. realised that utilisation of Manganese ore fines will pave the way for conservation of lumpy high grade manganese ore. Manganese ore fines generated at Balaghat and Ukwa mines of MOIL were subjected to sintering studies at the R&D Centre of Paramount Sinters Pvt. Ltd. The studies indicated that fluxed sinter with very good strength and porosity could be produced. The sinters showed a high degree of reduction and even metalization was noticed. The chemical and physical characteristics indicated that sinters can be used in ferro manganese furnaces. Advantages of using sinter in the ferro alloy manufacture has been highlighted in this report. The authors have conc-luded that from the point of view of conservation and reduction of manufacturing cost, sintering has a vital role to play in ferro alloy industries

    Genome analysis of amaranths: determination of inter- and intra-species variations

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    Amaranths are an important group of plants and include grain, vegetable and ornamental types. Despite the economic importance of the amaranths, there is very little information available about the extent and nature of genetic diversity present in the genus Amaranthus at molecular level. We now report the randomly amplified polymorphic DNA (RAPD) profiles of different species of Amaranthus as well as different accessions of the species. These RAPD analyses have been carried out using 65 arbitrary sequence decamer primers. From the RAPD data, an UPGMA dendrogram illustrating the inter-as well as intra-species relationships has been computed. The putative hybrid origin of A.dubious from A. hybridus and A. spinosus is also ruled out by the RAPD data. The trends of species relationships amongst the amaranths determined by RAPDs is consistent with their cytogenetic and evolutionary relationships that have already been determined

    Sulphanilamides. Part II. In vitro synergism with anionic surface-active compounds

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    1. The bacteriostatic properties of sulphanilamide and five N1-substituted sulphanilamides, and of three anionic surface-active compounds, have been studied, singly and together, against the organisms, S. aureus, E. coli, and E. typhosa, using peptone-broth and a synthetic medium. 2. With incubation temperatures of 37° and 43° the concentration of sulphanilamide for bacteriostasis in peptone medium is independent of the age of the culture and the concentration of the inoculum at the higher temperature only. In the synthetic medium, the effects of age of cells and size of inocula are less pronounced at both temperatures of incubation. 3. The minimum effective concentrations of sulpha drugs needed for growth inhibition are more in peptone broth than in the synthetic medium. Similar but less pronounced differences are seen with the surface-active compounds against S. aureus. 4. While the surface-active compounds are by themselves ineffective against the Gram-negative organisms, they have potentiating activity with the sulpha drugs. 5. The synergic effects of sulphanilamide and surface-active compound are unaltered even when the organism is rendered resistant to sulphanilamide or when the antibacterial property of the surface-active compound is neutralized by lecithin

    Evidence for facultative migratory flight behavior in Helicoverpa armigera (Noctuidae: Lepidoptera) in India

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    Despite its deleterious impact on farming and agriculture, the physiology and energetics of insect migration is poorly understood due to our inability to track their individual movements in the field. Many insects, e.g. monarch butterflies, Danaus plexippus (L.), are facultative migrants. Hence, it is important to establish whether specific insect populations in particular areas migrate. The polyphagous insect, Helicoverpa armigera (Hubner), is especially interesting in this regard due to its impact on a variety of crops. Here, we used a laboratory based flight mill assay to show that Helicoverpa armigera populations clearly demonstrate facultative migration in South India. Based on various flight parameters, we categorized male and female moths as long, medium or short distance fliers. A significant proportion of moths exhibited long-distance flight behaviour covering more than 10 km in a single night, averaging about 8 flight hours constituting 61% flight time in the test period. The maximum and average flight speeds of these long fliers were greater than in the other categories. Flight activity across sexes also varied; male moths exhibited better performance than female moths. Wing morphometric parameters including forewing length, wing loading, and wing aspect ratio were key in influencing long-distance flight. Whereas forewing length positively correlated with flight distance and duration, wing loading was negatively correlated

    Co-circulation of SARS-CoV-2 Alpha and Gamma variants in Italy, February and March 2021

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    Background. Several SARS-CoV-2 variants of concern (VOC) have emerged through 2020 and 2021. There is need for tools to estimate the relative transmissibility of emerging variants of SARS-CoV-2 with respect to circulating strains.AimWe aimed to assess the prevalence of co-circulating VOC in Italy and estimate their relative transmissibility.Methods. We conducted two genomic surveillance surveys on 18 February and 18 March 2021 across the whole Italian territory covering 3,243 clinical samples and developed a mathematical model that describes the dynamics of co-circulating strains.Results. The Alpha variant was already dominant on 18 February in a majority of regions/autonomous provinces (national prevalence: 54%) and almost completely replaced historical lineages by 18 March (dominant across Italy, national prevalence: 86%). We found a substantial proportion of the Gamma variant on 18 February, almost exclusively in central Italy (prevalence: 19%), which remained similar on 18 March. Nationally, the mean relative transmissibility of Alpha ranged at 1.55-1.57 times the level of historical lineages (95% CrI: 1.45-1.66). The relative transmissibility of Gamma varied according to the assumed degree of cross-protection from infection with other lineages and ranged from 1.12 (95% CrI: 1.03-1.23) with complete immune evasion to 1.39 (95% CrI: 1.26-1.56) for complete cross-protection.Conclusion. We assessed the relative advantage of competing viral strains, using a mathematical model assuming different degrees of cross-protection. We found substantial co-circulation of Alpha and Gamma in Italy. Gamma was not able to outcompete Alpha, probably because of its lower transmissibility
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