180 research outputs found

    An efficient algorithm for the retarded time equation for noise from rotating sources

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    This study concerns modelling of noise emanating from rotating sources such as helicopter rotors. We present an accurate and efficient algorithm for the solution of the retarded time equation, which can be used both in subsonic and supersonic flow regimes. A novel approach for the search of the roots of the retarded time function was developed based on considerations of the kinematics of rotating sources and of the bifurcation analysis of the retarded time function. It is shown that the proposed algorithm is faster than the classical Newton and Brent methods, especially in the presence of sources rotating supersonically

    The Fission Yeast XMAP215 Homolog Dis1p Is Involved in Microtubule Bundle Organization

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    Microtubules are essential for a variety of fundamental cellular processes such as organelle positioning and control of cell shape. Schizosaccharomyces pombe is an ideal organism for studying the function and organization of microtubules into bundles in interphase cells. Using light microscopy and electron tomography we analyzed the bundle organization of interphase microtubules in S. pombe. We show that cells lacking ase1p and klp2p still contain microtubule bundles. In addition, we show that ase1p is the major determinant of inter-microtubule spacing in interphase bundles since ase1 deleted cells have an inter-microtubule spacing that differs from that observed in wild-type cells. We then identified dis1p, a XMAP215 homologue, as factor that promotes the stabilization of microtubule bundles. In wild-type cells dis1p partially co-localized with ase1p at regions of microtubule overlap. In cells deleted for ase1 and klp2, dis1p accumulated at the overlap regions of interphase microtubule bundles. In cells lacking all three proteins, both microtubule bundling and inter-microtubule spacing were further reduced, suggesting that Dis1p contributes to interphase microtubule bundling

    Mto2 multisite phosphorylation inactivates non-spindle microtubule nucleation complexes during mitosis

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    Microtubule nucleation is highly regulated during the eukaryotic cell cycle, but the underlying molecular mechanisms are largely unknown. During mitosis in fission yeast Schizosaccharomyces pombe, cytoplasmic microtubule nucleation ceases simultaneously with intranuclear mitotic spindle assembly. Cytoplasmic nucleation depends on the Mto1/2 complex, which binds and activates the γ-tubulin complex and also recruits the γ-tubulin complex to both centrosomal (spindle pole body) and non-centrosomal sites. Here we show that the Mto1/2 complex disassembles during mitosis, coincident with hyperphosphorylation of Mto2 protein. By mapping and mutating multiple Mto2 phosphorylation sites, we generate mto2-phosphomutant strains with enhanced Mto1/2 complex stability, interaction with the γ-tubulin complex and microtubule nucleation activity. A mutant with 24 phosphorylation sites mutated to alanine, mto2[24A], retains interphase-like behaviour even in mitotic cells. This provides a molecular-level understanding of how phosphorylation ‘switches off' microtubule nucleation complexes during the cell cycle and, more broadly, illuminates mechanisms regulating non-centrosomal microtubule nucleation

    Chemical and protein structural basis for biological crosstalk between PPARα and COX enzymes

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    We have previously validated a probabilistic framework that combined computational approaches for predicting the biological activities of small molecule drugs. Molecule comparison methods included molecular structural similarity metrics and similarity computed from lexical analysis of text in drug package inserts. Here we present an analysis of novel drug/target predictions, focusing on those that were not obvious based on known pharmacological crosstalk. Considering those cases where the predicted target was an enzyme with known 3D structure allowed incorporation of information from molecular docking and protein binding pocket similarity in addition to ligand-based comparisons. Taken together, the combination of orthogonal information sources led to investigation of a surprising predicted relationship between a transcription factor and an enzyme, specifically, PPARα and the cyclooxygenase enzymes. These predictions were confirmed by direct biochemical experiments which validate the approach and show for the first time that PPARα agonists are cyclooxygenase inhibitors

    Open rotors: Modelling of coupled open rotor intakes: TP400 analysis

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    Open rotor inlet duct modelling

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    Open rotors: Modelling of coupled open rotor intakes: TP400 analysis

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    Per un nuovo patto di solidarietà. Il ruolo della Pedagogia nella costruzione dipercorsi identitari, spazi di cittadinanza e dialoghi interculturali. Note introduttive

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    Nelle Note introduttive si focalizza l'attenzione sul nesso tra sapere pedagogico e progetto interculturale. Vengono poi presentati i contenuti dei vari saggi presenti nel volum

    Per un nuovo patto di solidarietà. Il ruolo della pedagogia nella costruzione di percorsi identitari, spazi di cittadinanza e dialoghi interculturali

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    Il volume raccoglie idee, suggestioni, riflessioni, proposte emerse nel corso del seminario Siped sul tema: Per un nuovo patto di solidarietà. Il ruolo della Pedagogia nella costruzione di percorsi identitari, spazi di cittadinanza e dialoghi interculturali, tenutosi presso l'Università di Foggia nei giorni 31 marzo e 1 aprile 2016
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