755 research outputs found

    Zoo-FISH in the European mole (Talpa europaea) detects all ancestral Boreo-Eutherian human homologous chromosome associations

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    Zoo-FISH with human whole-chromosome paint probes delineated syntenic association of human homologous chromosome segments 3-21, 14-15, 16-19, 4-8, 7-16 and 12-22 (twice) in the European mole (Talpa europaea, Talpidae, Eulipotyphla, Mammalia). These segment associations represent shared ancestral Boreo-Eutherian traits, half of which were previously not described for Eulipotyphla. The karyotype of the European mole acquired a minimum of 19 translocations and six inversions compared to the presumed Boreo-Eutherian ancestor. Copyright (c) 2006 S. Karger AG, Basel

    A Simple Assembly for Carbon Determination in Water

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    The classical assembly for carbon and hydrogen analysis in organic compounds was modified for the determination of carbon in water samples. Numerous analyses of known solutions and of waste and surface waters containing 5 mg-10 g carbon/I were performed. The accuracy and reproducibility of results were satisfactory. The range of applicability is limited by the sensitivity of the gravimetric determination: on one side and on the other by the sample volume accessible

    The PLATO End-to-End CCD Simulator -- Modelling space-based ultra-high precision CCD photometry for the assessment study of the PLATO Mission

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    The PLATO satellite mission project is a next generation ESA Cosmic Vision satellite project dedicated to the detection of exo-planets and to asteroseismology of their host-stars using ultra-high precision photometry. The main goal of the PLATO mission is to provide a full statistical analysis of exo-planetary systems around stars that are bright and close enough for detailed follow-up studies. Many aspects concerning the design trade-off of a space-based instrument and its performance can best be tackled through realistic simulations of the expected observations. The complex interplay of various noise sources in the course of the observations made such simulations an indispensable part of the assessment study of the PLATO Payload Consortium. We created an end-to-end CCD simulation software-tool, dubbed PLATOSim, which simulates photometric time-series of CCD images by including realistic models of the CCD and its electronics, the telescope optics, the stellar field, the pointing uncertainty of the satellite (or Attitude Control System [ACS] jitter), and all important natural noise sources. The main questions that were addressed with this simulator were the noise properties of different photometric algorithms, the selection of the optical design, the allowable jitter amplitude, and the expected noise budget of light-curves as a function of the stellar magnitude for different parameter conditions. The results of our simulations showed that the proposed multi-telescope concept of PLATO can fulfil the defined scientific goal of measuring more than 20000 cool dwarfs brighter than mV =11 with a precision better than 27 ppm/h which is essential for the study of earth-like exo-planetary systems using the transit method.Comment: 5 pages, submitted for the Proceedings of the 4th HELAS International Conference: Seismological Challenges for Stellar Structur

    Massive Superparticle with Tensorial Central Charges

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    We construct the manifestly Lorenz-invariant formulation of the N=1 D=4 massive superparticle with tensorial central charges. The model contains a real parameter k and at k0k\ne 0 possesses one κ\kappa-symmetry while at k=0 the number of κ\kappa-symmetry is two. The equivalence of the formulations at all k0k\ne 0 is obtained. The local transformations of κ\kappa-symmetry are written out. It is considered the using of index spinor for construction of the tensorial central charges. It is obtained the equivalence at classical level between the massive D=4 superparticle with one κ\kappa-symmetry and the massive D=4 spinning particleComment: 20 pages, Late

    Line-profile variations of stochastically excited oscillations in four evolved stars

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    Since solar-like oscillations were first detected in red-giant stars, the presence of non-radial oscillation modes has been debated. Spectroscopic line-profile analysis was used in the first attempt to perform mode identification, which revealed that non-radial modes are observable. Despite the fact that the presence of non-radial modes could be confirmed, the degree or azimuthal order could not be uniquely identified. Here we present an improvement to this first spectroscopic line-profile analysis. Aims: We aim to study line-profile variations of stochastically excited solar-like oscillations in four evolved stars to derive the azimuthal order of the observed mode and the surface rotational frequency. Methods: Spectroscopic line-profile analysis is applied to cross-correlation functions, using the Fourier Parameter Fit method on the amplitude and phase distributions across the profiles. Results: For four evolved stars, beta Hydri (G2IV), epsilon Ophiuchi (G9.5III), eta Serpentis (K0III) and delta Eridani (K0IV) the line-profile variations reveal the azimuthal order of the oscillations with an accuracy of ~1. Furthermore, our analysis reveals the projected rotational velocity and the inclination angle. From these parameters we obtain the surface rotational frequency. Conclusions: We conclude that line-profile variations of cross-correlation functions behave differently for different frequencies and that they provide additional information in terms of the surface rotational frequency and azimuthal order.Comment: Accepted for publication in Astronomy and Astrophysics, 9 pages, 10 figures and 3 tables. A version with figure 1 in full resolution can be obtained upon request from first autho

    Uniform Twistor-Like Formulation of Massive and Massless Superparticles with Tensorial Central Charges

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    We construct the manifestly Lorentz-invariant twistorial formulation of N=1 D=4 superparticle with tensorial central charges which describes massive and massless cases in a uniform manner. The tensorial central charges are realized in terms of even spinor variables and central charge coordinates. The full analysis of the number of conserved supersymmetries has been carried out. In the massive case the superparticle preserves 1/4 or 1/2 of target-space supersymmetries whereas the massless superparticle preserves two or three supersymmetries.Comment: LaTex2e file, espcrc2.sty, 7 pages. Based on talk given at the D. V. Volkov Memorial Conference "Supersymmetry and Quantum Field Theory" (25-29 July, 2000, Kharkov, Ukraine). To be published in Nuclear Physics B Conference Supplement

    An asteroseismic study of the beta Cephei star 12 Lacertae: multisite spectroscopic observations, mode identification and seismic modelling

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    We present the results of a spectroscopic multisite campaign for the beta Cephei star 12 (DD) Lacertae. Our study is based on more than thousand high-resolution high S/N spectra gathered with 8 different telescopes in a time span of 11 months. In addition we make use of numerous archival spectroscopic measurements. We confirm 10 independent frequencies recently discovered from photometry, as well as harmonics and combination frequencies. In particular, the SPB-like g-mode with frequency 0.3428 1/d reported before is detected in our spectroscopy. We identify the four main modes as (l1,m1) = (1, 1), (l2,m2) = (0, 0), (l3,m3) = (1, 0) and (l4,m4) = (2, 1) for f1 = 5.178964 1/d, f2 = 5.334224 1/d, f3 = 5.066316 1/d and f4 = 5.490133 1/d, respectively. Our seismic modelling shows that f2 is likely the radial first overtone and that the core overshooting parameter alpha_ov is lower than 0.4 local pressure scale heights.Comment: 16 pages, 11 figures, accepted in MNRA
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