The universal anomalies in the normal state of Cu-0 high-temperature superconductors follow from a single hypothesis: There exist chargeand spin-density excitations with the absorptive part of the polarizability at low frequencies co proportional to co/T, where T is the temperature, and constant otherwise. The behavior in such a situation may be characterized as that of a marginal Fermi liquid. The consequences of this hypothesis are worked out for a variety of physical properties including superconductivity.PACS numbers: 74.70.VyThe normal-state properties of the Cu-0 superconductors are as perplexing as their high transition temperatures. The electrical resistivity p(T), ' the thermal conductivity x(T), the optical conductivity cr(co), the Raman scattering intensity S(ro), the tunneling conductance as a function of voltage g(V), the nuclear relaxation rate T~' (T), and the Hall coefficient RH(T) (Ref.

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RNA chain elongation is a highly processive and accurate process that is finely regulated by numerous intrinsic and extrinsic signals. Here we describe a general mechanism that governs RNA polymerase (RNAP) movement and response to regulatory inputs such as pauses, terminators, and elongation factors. We show that E.coli RNAP moves by a complex Brownian ratchet mechanism, which acts prior to phosphodiester bond formation. The incoming substrate and the flexible F bridge domain of the catalytic center serve as two separate ratchet devices that function in concert to drive forward translocation. The adjacent G loop domain controls F bridge motion, thus keeping the proper balance between productive and inactive states of the elongation complex. This balance is critical for cell viability since it determines the rate, processivity, and fidelity of transcription.

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