Entropy involved in fidelity of DNA replication

Information has an entropic character which can be analyzed within the Statistical Theory in molecular systems. R. Landauer and C.H. Bennett showed that a logical copy can be carried out in the limit of no dissipation if the computation is performed sufficiently slowly. Structural and recent single-molecule assays have provided dynamic details of polymerase machinery with insight into information processing. We introduce a rigorous characterization of Shannon Information in biomolecular systems and apply it to DNA replication in the limit of no dissipation. Specifically, we devise an equilibrium pathway in DNA replication to determine the entropy generated in copying the information from a DNA template in the absence of friction. Both the initial state, the free nucleotides randomly distributed in certain concentrations, and the final state, a polymerized strand, are mesoscopic equilibrium states for the nucleotide distribution. We use empirical stacking free energies to calculate the probabilities of incorporation of the nucleotides. The copied strand is, to first order of approximation, a state of independent and non-indentically distributed random variables for which the nucleotide that is incorporated by the polymerase at each step is dictated by the template strand, and to second order of approximation, a state of non-uniformly distributed random variables with nearest-neighbor interactions for which the recognition of secondary structure by the polymerase in the resultant double-stranded polymer determines the entropy of the replicated strand. Two incorporation mechanisms arise naturally and their biological meanings are explained. It is known that replication occurs far from equilibrium and therefore the Shannon entropy here derived represents an upper bound for replication to take place. Likewise, this entropy sets a universal lower bound for the copying fidelity in replication.Comment: 25 pages, 5 figure

Optical photometry of the UCM Lists I and II

We present Johnson B CCD photometry for the whole sample of galaxies of the Universidad Complutense de Madrid (UCM) Survey Lists I and II. They constitute a well-defined and complete sample of galaxies in the Local Universe with active star formation. The data refer to 191 S0 to Irr galaxies at an averaged redshift of 0.027, and complement the already published Gunn r, J and K photometries. In this paper the observational and reduction features are discussed in detail, and the new colour information is combined to search for clues on the properties of the galaxies, mainly by comparing our sample with other surveys.Comment: 14 pages, 7 PostScript figures, accepted for publication in A&AS, also available vi ftp at ftp://cutrex.fis.ucm.es/pub/OUT/pag/PAPERS

Global analysis of the negative parity non-strange baryons in the 1/Nc expansion

A global study of the negative parity non-strange baryon observables is performed in the frame- work of the 1/Nc expansion. Masses, partial decay widths and photo-couplings are simultaneously analyzed. A main objective is to determine the composition of the spin 1/2 and 3/2 nucleon states, which come in pairs and involve two mixing angles which can be determined and tested for consistency by the mentioned observables. The issue of the assignment of those nucleon states to the broken SU(4) x O(3) mixed-symmetry multiplet is studied in detail, with the conclusion that the assignment made in the old studies based on the non-relativistic quark model is the preferred one. In addition, the analysis involves an update of the input data with respect to previous works.Comment: 30 pages, 3 figure

Weyl geometry, anti-De Sitter space, and Φ4\Phi^4-theory

We study the Gaussian approximation to the quantum fluctuations of the metric of the four dimensional anti-De Sitter spacetime. The associated massless scalar field has a quartic self interaction, for which we construct the generating functional of the $n$-point correlation functions. The concomitant infrared divergence is cured by a mass renormalization provided by the cosmological constant, which is also responsible for the renormalization of the coupling constant of the field theory.Comment: 9 pages, 1 figur

Statistics of the fractional polarisation of extragalactic dusty sources in Planck HFI maps

We estimate the average fractional polarisation at 143, 217 and 353 GHz of a sample of 4697 extragalactic dusty sources by applying stacking technique. The sample is selected from the second version of the Planck Catalogue of Compact Sources at 857 GHz, avoiding the region inside the Planck Galactic mask (fsky ~ 60 per cent). We recover values for the mean fractional polarisation at 217 and 353 GHz of (3.10 \pm 0.75) per cent and (3.65 \pm 0.66) per cent, respectively, whereas at 143 GHz we give a tentative value of (3.52 \pm 2.48) per cent. We discuss the possible origin of the measured polarisation, comparing our new estimates with those previously obtained from a sample of radio sources. We test different distribution functions and we conclude that the fractional polarisation of dusty sources is well described by a log-normal distribution, as determined in the radio band studies. For this distribution we estimate {\mu}_{217GHz} = 0.3 \pm 0.5 (that would correspond to a median fractional polarisation of {\Pi}_{med} = (1.3 \pm 0.7) per cent) and {\mu}_{353GHz} = 0.7 \pm 0.4 ({\Pi}_{med} = (2.0 \pm 0.8) per cent), {\sigma}_{217GHz} = 1.3 \pm 0.2 and {\sigma}_{353GHz} = 1.1 \pm 0.2. With these values we estimate the source number counts in polarisation and the contribution given by these sources to the CMB B-mode angular power spectrum at 217, 353, 600 and 800 GHz. We conclude that extragalactic dusty sources might be an important contaminant for the primordial B-mode at frequencies > 217 GHz.Comment: arXiv admin note: text overlap with arXiv:1703.0995

Two-Dimensional Supersymmetric Quantum Mechanics: Two Fixed Centers of Force

The problem of building supersymmetry in the quantum mechanics of two Coulombian centers of force is analyzed. It is shown that there are essentially two ways of proceeding. The spectral problems of the SUSY (scalar) Hamiltonians are quite similar and become tantamount to solving entangled families of Razavy and Whittaker-Hill equations in the first approach. When the two centers have the same strength, the Whittaker-Hill equations reduce to Mathieu equations. In the second approach, the spectral problems are much more difficult to solve but one can still find the zero-energy ground states.Comment: This is a contribution to the Proc. of the Seventh International Conference ''Symmetry in Nonlinear Mathematical Physics'' (June 24-30, 2007, Kyiv, Ukraine), published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA