2,880 research outputs found

    Understanding the production of dual BEC with sympathetic cooling

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    We show, both experimentally and theoretically, that sympathetic cooling of 87^{87}Rb atoms in the ∣F=2,mF=2>|F=2,m_F=2> state by evaporatively cooled atoms in the ∣F=1,mF=−1>|F=1,m_F=-1> state can be precisely controlled to produce dual or single condensate in either state. We also study the thermalization rate between two species. Our model renders a quantitative account of the observed role of the overlap between the two clouds and points out that sympathetic cooling becomes inefficient when the masses are very different. Our calculation also yields an analytical expression of the thermalization rate for a single species.Comment: 3 figure

    Sympathetic Cooling with Two Atomic Species in an Optical Trap

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    We simultaneously trap ultracold lithium and cesium atoms in an optical dipole trap formed by the focus of a CO2_2 laser and study the exchange of thermal energy between the gases. The cesium gas, which is optically cooled to 20μ20 \muK, efficiently decreases the temperature of the lithium gas through sympathetic cooling. The measured cross section for thermalizing 133^{133}Cs-7^7Li collisions is 8×10−128 \times 10^{-12} cm2^2, for both species in their lowest hyperfine ground state. Besides thermalization, we observe evaporation of lithium purely through elastic cesium-lithium collisions (sympathetic evaporation).Comment: 4 pages 3 fig

    High-throughput screening of tick-borne pathogens in Europe

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    Due to increased travel, climatic, and environmental changes, the incidence of tick-borne disease in both humans and animals is increasing throughout Europe. Therefore, extended surveillance tools are desirable. To accurately screen tick-borne pathogens (TBPs), a large scale epidemiological study was conducted on 7050 Ixodes ricinus nymphs collected from France, Denmark, and the Netherlands using a powerful new high-throughput approach. This advanced methodology permitted the simultaneous detection of 25 bacterial, and 12 parasitic species (including; Borrelia, Anaplasma, Ehrlichia, Rickettsia, Bartonella, Candidatus Neoehrlichia, Coxiella, Francisella, Babesia, and Theileria genus) across 94 samples. We successfully determined the prevalence of expected (Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia helvetica, Candidatus Neoehrlichia mikurensis, Babesia divergens, Babesia venatorum), unexpected (Borrelia miyamotoi), and rare (Bartonella henselae) pathogens in the three European countries. Moreover we detected Borrelia spielmanii, Borrelia miyamotoi, Babesia divergens, and Babesia venatorum for the first time in Danish ticks. This surveillance method represents a major improvement in epidemiological studies, able to facilitate comprehensive testing of TBPs, and which can also be customized to monitor emerging diseases
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