58 research outputs found

    Totally Umbilical Pseudo-Slant Submanifolds of a Nearly Cosymplectic Manifold

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    2000 Mathematics Subject Classification: 53C40, 53B25.In the present note we study totally umbilical pseudo-slant submanifolds of a nearly cosymplectic manifold. We have obtained a classification theorem for totally umbilical pseudo-slant submanifolds of a nearly cosymplectic manifold

    Wheat streak mosaic virus: a century old virus with rising importance worldwide

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    Wheat streak mosaic virus (WSMV) causes wheat streak mosaic, a disease of cereals and grasses that threatens wheat production worldwide. It is a monopartite, positive-sense, single-stranded RNA virus and the type member of the genus Tritimovirus in the family Potyviridae. The only known vector is the wheat curl mite (WCM, Aceria tosichella), recently identified as a species complex of biotypes differing in virus transmission. Low rates of seed transmission have been reported. Infected plants are stunted and have a yellow mosaic of parallel discontinuous streaks on the leaves. In the autumn, WCMs move from WSMV-infected volunteer wheat and other grass hosts to newly emerged wheat and transmit the virus which survives the winter within the plant, and the mites survive as eggs, larvae, nymphs or adults in the crown and leaf sheaths. In the spring/summer, the mites move from the maturing wheat crop to volunteer wheat and other grass hosts and transmit WSMV, and onto newly emerged wheat in the fall to which they transmit the virus, completing the disease cycle. WSMV detection is by enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR) or quantitative RT-PCR (RT-qPCR). Three types of WSMV are recognized: A (Mexico), B (Europe, Russia, Asia) and D (USA, Argentina, Brazil, Australia, Turkey, Canada). Resistance genes Wsm1, Wsm2 and Wsm3 have been identified. The most effective, Wsm2, has been introduced into several wheat cultivars. Mitigation of losses caused by WSMV will require enhanced knowledge of the biology of WCM biotypes and WSMV, new or improved virus detection techniques, the development of resistance through traditional and molecular breeding, and the adaptation of cultural management tactics to account for climate change

    Identification and molecular characterization of the putative immunophilins (IMMs) in the oilseed rape pathogens Leptosphaeria maculans, Leptosphaeria biglobosa, and Plasmodiophora brassicae

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    Oilseed rape is largely infected by several phytopathogens and two most economical important diseases are blackleg caused by fungus species complex Leptosphaeria maculans and L. biglobosa and clubroot caused by protist P. brassicae. The sequenced genomes of these phytopathogens provide opportunity to uncover various aspects related to disease infection, host pathogen interactions, plant disease resistance, and evolution of pathogens. Considering these we focused on one of the most conserved family called immunophilins (IMMs) in these genomes. IMMs are comprised of three structurally unrelated sub-families including cyclophilins (CYPs), FK506-binding proteins (FKBPs), and parvulin-like proteins (PARs). We identified putative members of IMMs in each phytopathogen using bioinformatics approaches. We further characterized the IMMs based on domain architecture, subcellular localization, exon-intron organization, transcriptomic expression patterns, gene ontology terms, conserved motifs presents and evolutionary analyses. IMMs are performing several vital roles in plants, animals and fungi. However, in phytopathogens their roles are not well established except for cyclophilin that implicates in pathogenicity in some phytopathogens. Therefore, we exploited the role of cyclophilin in L. maculans and L. biglobosa using expression profiles and in P. brassicae using Magnaporthe oryzae cyclophilin deletion mutant. Overall, we concluded that the cyclophilin acts as a virulence determinant in our studied phytopathogens. However, delineating the precise role of other IMMs would also be imperative. Taken together, our findings for the first time shed light on the highly conserved IMM family in the oilseed rape pathogens

    Khushwantnama: the lessons of my life

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    In Khushwantnama, the writer reflects on a life lived fully and the lessons it has taught him. Here is his distilled wisdom on subjects as diverse as old age and the fear of death, on the joy of sex, the pleasures of poetry and the importance of laughter, on how to cope with retirement and live a long, happy and healthy life. Here, too, are his reflections on politics, politicians and the future of India, on what it takes to be a writer and on what religion means to hi
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