46,605 research outputs found

    3C 345: the historical light curve (1967-1990) from the digitized plates of the Asiago Observatory

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    In the frame of a large project to digitize the plate archives of the Italian and Vatican Astronomical Observatories, we have already performed the digitization of all available plates of the field of the quasar 3C345. The plates, approximately 100, were taken with the three telescopes of the Asiago Observatory (122 cm, 182 cm, 67/90 cm Schmidt Telescope) in the period from 1967 to 1990. We present here essentially new data, mostly in the B band, about the variability of 3C 345 and also of other four objects (3 quasars and the active galaxy NGC 6212) in the same field, in that period. Beyond the well known 3C 345 itself, also the other three quasars show variability, with a range of 2.0 mag for Q1 and Q2, 1 mag for Q3. The low level variability detected for the nucleus of NGC 6212 is more suspicious, and should be confirmed by linear detector data.Comment: 8 pages, 9 figures, 7 tables, submitted to MNRA

    A novel iterative strategy for protein design

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    We propose and discuss a novel strategy for protein design. The method is based on recent theoretical advancements which showed the importance to treat carefully the conformational free energy of designed sequences. In this work we show how computational cost can be kept to a minimum by encompassing negative design features, i.e. isolating a small number of structures that compete significantly with the target one for being occupied at low temperature. The method is succesfully tested on minimalist protein models and using a variety of amino acid interaction potentials.Comment: 9 pages, 8 figure

    Scalar Dark Matter in light of LEP and ILC Experiments

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    In this work we study a scalar field dark matter model with mass of the order of 100 MeV. We assume dark matter is produced in the process e−+e+→ϕ+ϕ∗+γe^-+e^+\to \phi +\phi^*+\gamma, that, in fact, could be a background for the standard process e−+e+→ν+νˉ+γe^-+e^+\to \nu +\bar\nu+\gamma extensively studied at LEP. We constrain the chiral couplings, CLC_L and CRC_R, of the dark matter with electrons through an intermediate fermion of mass mF=100m_F=100 GeV and obtain CL=0.1(0.25)C_L=0.1(0.25) and CR=0.25(0.1)C_R=0.25(0.1) for the best fit point of our χ2\chi^2 analysis. We also analyze the potential of ILC to detect this scalar dark matter for two configurations: (i) center of mass energy s=500\sqrt{s}=500 GeV and luminosity L=250\mathcal{L}=250 fb−1^{-1}, and (ii) center of mass energy s=1\sqrt{s}=1 TeV and luminosity L=500\mathcal{L}=500 fb−1^{-1}. The differences of polarized beams are also explored to better study the chiral couplings.Comment: 15 pages, 6 figures and 1 table. New references added and improvements in the text. Conclusions unchange
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