Efficacy of disinfectants and hand sanitizers against avian respiratory viruses     

Patnayak DP  Prasad AM  Malik YS  Ramakrishnan MA  Goyal SM 《Avian diseases》2008,52(2):199-202

Disinfectants play a major role in the control of animal diseases by decontaminating the farm environment. We evaluated the virucidal efficacy of nine commonly used disinfectants on a nonporous surface contaminated experimentally with avian metapneumovirus (aMPV), avian influenza virus, or Newcastle disease virus (NDV). Phenolic compounds and glutaraldehyde were found to be the most effective against all three viruses. Quaternary ammonium compounds were effective against aMPV but not against the other two viruses. In addition, efficacy of commercially available hand sanitizers was evaluated on human fingers contaminated with aMPV and NDV. All three hand sanitizers tested were found to be effective against both viruses within 1 min of application on fingers.  相似文献   

Methane production in unamended and rice-straw-amended soil at different moisture levels   总被引：3，自引：0，他引：3  

A. K. Rath  S. R. Mohanty  S. Mishra  S. Kumaraswamy  B. Ramakrishnan  N. Sethunathan 《Biology and Fertility of Soils》1999,28(2):145-149

 CH₄ production in an alluvial soil, unamended or amended with rice straw (1% w/w), was examined under nonflooded [–1.5 MPa, –0.01 MPa and 0 MPa (saturated) and flooded (1 : 1.25 soil to water ratio)] conditions during a 40-day incubation in closed Vacutainer tubes. CH₄ production was negligible at –1.5 MPa, but increased with an increase in the moisture level. Addition of rice straw distinctly increased CH₄ production in the soil at all moisture levels including –1.5 MPa. Evidence, in terms of the drop in redox potential and Fe²⁺ accumulated, suggested that the addition of rice straw hastened the reduction of the soil, even under nonflooded conditions; thus its addition stimulated even the nonflooded soil to produce CH₄ in substantial amounts. Our results indicate that many currently unidentified sources of CH₄, possibly including organic-amended nonflooded soils, may make a significant contribution to the global CH₄ budget. Received: 10 July 1997  相似文献   

Granuloma-specific expression of Mycobacterium virulence proteins from the glycine-rich PE-PGRS family     

Ramakrishnan L  Federspiel NA  Falkow S 《Science (New York, N.Y.)》2000,288(5470):1436-1439

Pathogenic mycobacteria, including the agent of tuberculosis, Mycobacterium tuberculosis, must replicate in macrophages for long-term persistence within their niche during chronic infection: organized collections of macrophages and lymphocytes called granulomas. We identified several genes preferentially expressed when Mycobacterium marinum, the cause of fish and amphibian tuberculosis, resides in host granulomas and/or macrophages. Two were homologs of M. tuberculosis PE/PE-PGRS genes, a family encoding numerous repetitive glycine-rich proteins of unknown function. Mutation of two PE-PGRS genes produced M. marinum strains incapable of replication in macrophages and with decreased persistence in granulomas. Our results establish a direct role in virulence for some PE-PGRS proteins.  相似文献   

Wetland rice soils as sources and sinks of methane: a review and prospects for research   总被引：5，自引：0，他引：5  

S. Kumaraswamy  Arun Kumar Rath  B. Ramakrishnan  N. Sethunathan 《Biology and Fertility of Soils》2000,31(6):449-461

 Rice paddies are an important human-made ecosystem for the global CH₄ budget. CH₄, which is produced in the predominantly anaerobic bulk soil layers, is oxidized significantly before it reaches the atmosphere. Roots of rice, in addition to supporting the consumption of CH₄, contribute to the total CH₄ production in the soil. The various controls of CH₄ emission from this ecosystem depend on the structure of plant and microbial communities and their interactions. Availability of organic substrates, electron acceptors and other soil- and plant-related factors influence the activities of microbial communities. Agronomic practices including fertilization and application of pesticides have effects on CH₄ emission. Recent studies using molecular retrieval approaches with small subunit rRNA-encoding gene (rDNA) sequences and functional genes, showed the richness of diversity of the microbial community in rice paddy soils, which includes members of the Archaea and methanotrophs. There is need for further research to know the consequences, at the ecosystem level, of changes in microbial diversity and microbial communities in paddy soils. This will aid in understanding the mechanisms involved in the mitigating effects of certain agricultural practices. Received: 13 July 1999  相似文献   

Insights into translational termination from the structure of RF2 bound to the ribosome     

Weixlbaumer A  Jin H  Neubauer C  Voorhees RM  Petry S  Kelley AC  Ramakrishnan V 《Science (New York, N.Y.)》2008,322(5903):953-956

The termination of protein synthesis occurs through the specific recognition of a stop codon in the A site of the ribosome by a release factor (RF), which then catalyzes the hydrolysis of the nascent protein chain from the P-site transfer RNA. Here we present, at a resolution of 3.5 angstroms, the crystal structure of RF2 in complex with its cognate UGA stop codon in the 70S ribosome. The structure provides insight into how RF2 specifically recognizes the stop codon; it also suggests a model for the role of a universally conserved GGQ motif in the catalysis of peptide release.  相似文献   

Effect of the herbicide butachlor on methane emission and ebullition flux from a direct-seeded flooded rice field     

S. R. Mohanty  K. Bharati  B. T. S. Moorthy  B. Ramakrishnan  V. R. Rao  N. Sethunathan  T. K. Adhya 《Biology and Fertility of Soils》2001,33(3):175-180

 Application of a commercial formulation of the herbicide butachlor (N-butoxymethyl-2-chloro-2′,6′-diethyl acetanilide) at 1 kg a.i. ha^–1 to an alluvial soil planted with direct-seeded flooded rice (cv. Annada), significantly inhibited both crop-mediated emission and ebullition fluxes of methane (CH₄). Over a cropping period of 110 days, the crop-mediated cumulative emission flux of CH₄ was lowered by ∼20% in butachlor-treated field plots compared with that of an untreated control. Concurrently, ebollition flux of CH₄ was also retarded in butachlor-treated field plots by about 81% compared with that of control plots. Significant relationships existed between CH₄ emission and redox potential (E _h) and Fe²⁺ content of the flooded soil. Application of butachlor retarded a drop in soil redox potential as well as accumulation of Fe²⁺ in treated field plots. Methanogenic bacterial population, counted at the maturity stage of the crop, was also low in butachlor-treated plots, indicating both direct and indirect inhibitory effects of butachlor on methanogenic bacterial populations and their activity. Results indicate that butachlor, even at field-application level, can effectively abate CH₄ emission and ebollition from flooded soils planted to rice whilst maintaining grain yield. Received: 15 March 2000  相似文献   

Role of earthworms in nitrogen cycling during the cropping phase of shifting agriculture (Jhum) in north-east India   总被引：1，自引：0，他引：1  

Tunira Bhadauria  P. S. Ramakrishnan 《Biology and Fertility of Soils》1996,22(4):350-354

We investigated the role of earthworms in the N cycle in a shifting agriculture system under a 5- and a 15-year Jhum system fallow period intervening between two croppings on the same site. Earthworms participated in the N cycle through worm cast egestion, mucus production, and dead tissue decomposition. Soil N was initially depleted by volatilization during slash and burn operations, and subsequently during cultivation processes. These losses were more pronounced under the 15-year Jhum system. We also studied the addition of N to the system in crop residues, through weed recycling, or in compost applied as organic manure under both the 5- and the 15-year Jhum systems. The total soil N made available for uptake by the plant through the activity of earthworms in this agro-ecosystem was higher than the total input of N to the soil through the addition of slashed vegetation, inorganic and organic manure, and recycled crop residue and weeds. Therefore, in highly leached soils of the humid tropics, worm activity is particularly, important because of rapid incorporation of litter into the mineral soils and because of local concentrations of nutrients in the surface soil layers.  相似文献   

Molecular biology. The eukaryotic ribosome     

Ramakrishnan V 《Science (New York, N.Y.)》2011,331(6018):681-682

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Biomass allocation strategies and productivity of tropical trees related to successional status     

R.P. Shukla  P.S. Ramakrishnan 《Forest Ecology and Management》1984,9(4):315-324

The productivity and biomass allocation strategies of two early successional (ES) and two late successional (LS) tropical tree species were compared and related to their successional status. Apart from distinct differences in clean bole length, crown depth, maximum crown width and leaf area index (LAI), the ES species showed higher allocation to the shoot, particularly to the bole, whereas the LS species had higher allocation to the root. The ES species with shallow root system had more root biomass within the upper 20 cm of the soil profile while the LS species with deeper roots had a higher proportion of root biomass distributed below the 20 cm depth. The productivity of the shoot of ES species was significantly higher than that of LS species. However, root productivity for ES species was higher only up to 4 years of age; the differences were not significant between 5 and 7 years. The implication of these results for agroforestry and mixed plantation forestry is emphasized.  相似文献   

Horn cancer in bulls.     

S Damodaran  A Sundararaj  R Ramakrishnan 《The Indian veterinary journal》1979,56(3):248-249

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