1,640 research outputs found

    Formation of H3−_3^- by radiative association of H2_2 and H−^- in the interstellar medium

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    We develop the theory of radiative association of an atom and a diatomic molecule within a close-coupling framework. We apply it to the formation of H3−_3^- after the low energy collision (below 0.5 eV) of H2_2 with H−^-. Using recently obtained potential energy and permanent dipole moment surfaces of H3−_3^-, we calculate the lowest rovibrational levels of the H3−_3^- electronic ground state, and the cross section for the formation of H3−_3^- by radiative association between H−^- and ortho- and para-H2_2. We discuss the possibility for the H3−_3^- ion to be formed and observed in the cold and dense interstellar medium in an environment with a high ionization rate. Such an observation would be a probe for the presence of H−^- in the interstellar medium

    Phase information revealed by interferences in the ionization of rotational wavepackets

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    Time-resolved photoelectron spectra are proposed for the measurement of classical information recorded in the quantum phases of a molecular rotational wavepacket. Taking Li2 as a prototypical system, we show that an interference arises from the electron-nuclei entanglement induced by the molecular anisotropy. This phenomenon is used to transfer the information which has been stored initially in the nuclear rotational degree of freedom into the electronic degree of freedom

    Observation of diffractive orbits in the spectrum of excited NO in a magnetic field

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    We investigate the experimental spectra of excited NO molecules in the diamagnetic regime and develop a quantitative semiclassical framework to account for the results. We show the dynamics can be interpreted in terms of classical orbits provided that in addition to the geometric orbits, diffractive effects are appropriately taken into account. We also show how individual orbits can be extracted from the experimental signal and use this procedure to reveal the first experimental manifestation of inelastic diffractive orbits.Comment: 4 fig

    Evidence of a Louse-Borne Outbreak Involving Typhus in Douai, 1710-1712 during the War of Spanish Succession

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    Background: The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR. Methods: We identified a mass grave in Douai, France dating from the early XVIII th century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples. Results and Discussion: In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XX th century. Conclusion: Louse-borne outbreaks were raging during the XVIII th century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America

    Relative Riemann-Zariski spaces

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    In this paper we study relative Riemann-Zariski spaces attached to a morphism of schemes and generalizing the classical Riemann-Zariski space of a field. We prove that similarly to the classical RZ spaces, the relative ones can be described either as projective limits of schemes in the category of locally ringed spaces or as certain spaces of valuations. We apply these spaces to prove the following two new results: a strong version of stable modification theorem for relative curves; a decomposition theorem which asserts that any separated morphism between quasi-compact and quasi-separated schemes factors as a composition of an affine morphism and a proper morphism. (In particular, we obtain a new proof of Nagata's compactification theorem.)Comment: 30 pages, the final version, to appear in Israel J. of Mat

    Epidemic typhus imported from Algeria.

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    We report epidemic typhus in a French patient returning from Algeria. The diagnosis was confirmed by serologic testing and the isolation of Rickettsia prowazekii in blood. Initially the patient was thought to have typhoid fever. Because body lice are prevalent in industrialized regions, the introduction of typhus to pediculosis-endemic areas poses a serious public health risk

    Synergistic activity of sulbactam combined with colistin against colistin-resistant Acinetobacter baumannii

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    Acinetobacter baumannii is an emerging multidrug-resistant (MDR) pathogen that is responsible for community- and hospital-acquired infections that are difficult to control and treat [1]. With increasing antimicrobial resistance to carbapenems, colistin is often the treatment of last resort, however colistin-resistant clinical isolates have already been reported. Since therapeutic options are very limited or absent in some cases of infection with pandrug-resistant bacteria, there is an urgent need to find new antibiotic strategies
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