40,707 research outputs found

    Lucifer and the Arabic palaeography. A contribution on the Oriental glosses of the bible of Cava de' Tirreni

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    This contribution is intended to fill a gap in the series of studies already devoted to the glosses of the famous codex Cava 1, a Biblical manuscript written in early 9th-century Spain, and to contribute to its better understanding from a cultural and historical point of view. Sixteen glosses in Arabic language and script and one gloss in Hebrew script and Arabic language will be examined from a paleographical point of view, trying to propose a date and a place for their execution. Moreover, the paper will discuss the con- tents of these glosses, until now discarded by scholars

    Experimental observation of Frohlich superconductivity in high magnetic fields

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    Resistivity and irreversible magnetisation data taken within the high-magnetic-field CDWx phase of the quasi-two-dimensional organic metal alpha-(BEDT-TTF)2KHg(SCN)4 are shown to be consistent with a field-induced inhomogeneous superconducting phase. In-plane skin-depth measurements show that the resistive transition on entering the CDWx phase is both isotropic and representative of the bulk.Comment: ten pages, four figure

    Bees (Hymenoptera: Apoidea) of the Kitty Todd Preserve, Lucas County, Ohio

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    A survey of the bees occurring on the The Nature Conservancy’s Kitty Todd Preserve in the Oak Openings region of Lucas County Ohio was conducted in 2002-2004, using hand-netting techniques. Collecting effort totaled 24.5 hours spread over 11 different days in the three years. All sampling was done in natural communities. One hundred twenty-four species of bees were identified from fifty-one species of flowering plants, including several bee species poorly known or infrequently collected. Comments are provided about the faunistics, bee-plant relationships, oligolecty, management, and natural community dependency of the bees found on the Kitty Todd Preserve

    Anisotropic Impurity-States, Quasiparticle Scattering and Nematic Transport in Underdoped Ca(Fe1-xCox)2As2

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    Iron-based high temperature superconductivity develops when the `parent' antiferromagnetic/orthorhombic phase is suppressed, typically by introduction of dopant atoms. But their impact on atomic-scale electronic structure, while in theory quite complex, is unknown experimentally. What is known is that a strong transport anisotropy with its resistivity maximum along the crystal b-axis, develops with increasing concentration of dopant atoms; this `nematicity' vanishes when the `parent' phase disappears near the maximum superconducting Tc. The interplay between the electronic structure surrounding each dopant atom, quasiparticle scattering therefrom, and the transport nematicity has therefore become a pivotal focus of research into these materials. Here, by directly visualizing the atomic-scale electronic structure, we show that substituting Co for Fe atoms in underdoped Ca(Fe1-xCox)2As2 generates a dense population of identical anisotropic impurity states. Each is ~8 Fe-Fe unit cells in length, and all are distributed randomly but aligned with the antiferromagnetic a-axis. By imaging their surrounding interference patterns, we further demonstrate that these impurity states scatter quasiparticles in a highly anisotropic manner, with the maximum scattering rate concentrated along the b-axis. These data provide direct support for the recent proposals that it is primarily anisotropic scattering by dopant-induced impurity states that generates the transport nematicity; they also yield simple explanations for the enhancement of the nematicity proportional to the dopant density and for the occurrence of the highest resistivity along the b-axis

    Time step rescaling recovers continuous-time dynamical properties for discrete-time Langevin integration of nonequilibrium systems

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    When simulating molecular systems using deterministic equations of motion (e.g., Newtonian dynamics), such equations are generally numerically integrated according to a well-developed set of algorithms that share commonly agreed-upon desirable properties. However, for stochastic equations of motion (e.g., Langevin dynamics), there is still broad disagreement over which integration algorithms are most appropriate. While multiple desiderata have been proposed throughout the literature, consensus on which criteria are important is absent, and no published integration scheme satisfies all desiderata simultaneously. Additional nontrivial complications stem from simulating systems driven out of equilibrium using existing stochastic integration schemes in conjunction with recently-developed nonequilibrium fluctuation theorems. Here, we examine a family of discrete time integration schemes for Langevin dynamics, assessing how each member satisfies a variety of desiderata that have been enumerated in prior efforts to construct suitable Langevin integrators. We show that the incorporation of a novel time step rescaling in the deterministic updates of position and velocity can correct a number of dynamical defects in these integrators. Finally, we identify a particular splitting that has essentially universally appropriate properties for the simulation of Langevin dynamics for molecular systems in equilibrium, nonequilibrium, and path sampling contexts.Comment: 15 pages, 2 figures, and 2 table

    Assessing the benefits of international portfolio diversification in bonds and stocks.

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    This paper considers a stylized asset pricing model where the returns from exchange rates, stocks and bonds are linked by basic risk-arbitrage relationships. Employing GMM estimation and monthly data for 18 economies and the US (treated as the domestic country), we identify through a simple test the countries whose assets strongly comove with US assets and the countries whose assets might other larger diversification benefits. We also show that the strengthening of the comovement of returns across countries is neither a gradual process nor a global phenomenon, reinforcing the case for international diversification. However, our results suggest that fund managers are better other constructing portfolios selecting assets from a subset of countries than relying on either fully inter-nationally diversified or purely domestic portfolios. JEL Classification: F31, G10asset pricing, Exchange Rates, international parity conditions, market integration, stochastic discount factor

    Stark broadening of B IV lines for astrophysical and laboratory plasma research

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    Stark broadening parameters for 36 multiplets of B IV have been calculated using the semi-classical perturbation formalism. Obtained results have been used to investigate the regularities within spectral series and temperature dependence.Comment: 8 pages, 6 figures, 1 table, in press in Advances in Space Researc

    Sticky wages: evidence from quarterly microeconomic data

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    This paper documents nominal wage stickiness using an original quarterly firm-level dataset. We use the ACEMO survey, which reports the base wage for up to 12 employee categories in French firms over the period 1998 to 2005, and obtain the following main results. First, the quarterly frequency of wage change is around 35 percent. Second, there is some downward rigidity in the base wage. Third, wage changes are mainly synchronized within firms but to a large extent staggered across firms. Fourth, standard Calvo or Taylor schemes fail to match micro wage adjustment patterns, but fixed duration "Taylor-like" wage contracts are observed for a minority of firms. Based on a two-thresholds sample selection model, we perform an econometric analysis of wage changes. Our results suggest that the timing of wage adjustments is not state-dependent, and are consistent with existence of predetermined of wage changes. They also suggest that both backward- and forward-looking behavior is relevant in wage setting. JEL Classification: E24, J3wage predetermination, Wage stickiness
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