2,949 research outputs found
On the large values of the Riemann zeta-function on short segments of the critical line
In this paper, we obtain a series of new conditional lower bounds for the
modulus and the argument of the Riemann zeta function on very short segments of
the critical line, based on the Riemann hypothesis. In particular, the
conditional solution of one problem of A.A.Karatsuba is given. Some typos of
the previous versions are corrected (in particular, the important remark of
Prof. Yan Fyodorov is taken into account). The reference to the grant of
Russian Scientific Fund is also added.Comment: 40 pages, 4 figure
Nonlocal pseudopotentials and magnetic fields
We show how to describe the coupling of electrons to non-uniform magnetic
fields in the framework of the widely used norm-conserving pseudopotential
appro ximation for electronic structure calculations. Our derivation applies to
magnetic fields that are smooth on the scale of the core region. The method is
validated by application to the calculation of the magnetic susceptibility of
molecules. Our results are compared with high quality all electron quantum
chemical results, and another recently proposed formalism.Comment: 4 pages, submitted to Physical Review Letter
\u3cem\u3ePlasmodium falciparum\u3c/em\u3e SSB Tetramer Wraps Single-Stranded DNA with Similar Topology but Opposite Polarity to \u3cem\u3eE. coli\u3c/em\u3e SSB
Single-stranded DNA binding (SSB) proteins play central roles in genome maintenance in all organisms. Plasmodium falciparum, the causative agent of malaria, encodes an SSB protein that localizes to the apicoplast and likely functions in the replication and maintenance of its genome. P. falciparum SSB (Pf-SSB) shares a high degree of sequence homology with bacterial SSB proteins but differs in the composition of its C-terminus, which interacts with more than a dozen other proteins in Escherichia coli SSB (Ec-SSB). Using sedimentation methods, we show that Pf-SSB forms a stable homo-tetramer alone and when bound to single-stranded DNA (ssDNA). We also present a crystal structure at 2.1 Å resolution of the Pf-SSB tetramer bound to two (dT)35 molecules. The Pf-SSB tetramer is structurally similar to the Ec-SSB tetramer, and ssDNA wraps completely around the tetramer with a “baseball seam” topology that is similar to Ec-SSB in its “65 binding mode”. However, the polarity of the ssDNA wrapping around Pf-SSB is opposite to that observed for Ec-SSB. The interactions between the bases in the DNA and the amino acid side chains also differ from those observed in the Ec-SSB–DNA structure, suggesting that other differences may exist in the DNA binding properties of these structurally similar proteins
On the kinetic equation approach to pair production by time-dependent electric field
We investigate the quantum kinetic approach to pair production from vacuum by
time-dependent electric field. Equivalence between this approach and the more
familiar S-matrix approach is explicitly established for both scalar and
fermion cases. For the particular case of a constant electric field exact
solution for kinetic equations is provided and the accuracy of low-density
approximation is estimated.Comment: 8 pages, 4 figure
On the Rate of Convergence for a Characteristic of Multidimensional Birth-Death Process
We consider a multidimensional inhomogeneous birth-death process (BDP) and
obtain bounds on the rate of convergence for the corresponding one-dimensional
processes
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