7 research outputs found

    Phase slip scaling relationship for the 59 K and 143 K charge-density-waves in NbSe3

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    Selective area irradiation was used to create irradiated/unmodifïed/irradiated CDW heterostructures with well-defined interfaces on a single NbSe3 crystal. The temperature dependence of the extra voltage required for carrier conversion (phase slip voltage, Vps0) is extracted from length dependent studies. We find that the temperature dependence of Vps0 for the 143 K and 59 K CDW transitions are identical if properly scaled by the transition temperature. The Vps0 temperature dependence is not thermally activated, but contains an upper and lower temperature branch. The crossover temperature for the two branches is 0.75TP. For the 59 K CDW we observe a zero-bias resistance anomaly near a single irradiated/unmodified interface. This anomaly abruptly changes with temperature near 44 K suggesting a qualitative change in the phase slip mechanism near 0.75TP

    The Argonaute CSR-1 and its 22G-RNA cofactors are required for holocentric chromosome segregation.

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    RNAi-related pathways regulate diverse processes, from developmental timing to transposon silencing. Here, we show that in C. elegans the Argonaute CSR-1, the RNA-dependent RNA polymerase EGO-1, the Dicer-related helicase DRH-3, and the Tudor-domain protein EKL-1 localize to chromosomes and are required for proper chromosome segregation. In the absence of these factors chromosomes fail to align at the metaphase plate and kinetochores do not orient to opposing spindle poles. Surprisingly, the CSR-1-interacting small RNAs (22G-RNAs) are antisense to thousands of germline-expressed protein-coding genes. Nematodes assemble holocentric chromosomes in which continuous kinetochores must span the expressed domains of the genome. We show that CSR-1 interacts with chromatin at target loci but does not downregulate target mRNA or protein levels. Instead, our findings support a model in which CSR-1 complexes target protein-coding domains to promote their proper organization within the holocentric chromosomes of C. elegans.

    Cyclooxygenase-2 Inhibitors as a Therapeutic Target in Inflammatory Diseases

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