6,280 research outputs found

    Collective resonance modes of Josephson vortices in sandwiched stack of Bi2_{2}Sr2_{2}CaCu2_{2}O8+x_{8+x} intrinsic Josephson junctions

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    We observed splitting of the low-bias vortex-flow branch in a dense-Josephson-vortex state into multiple sub-branches in current-voltage characteristics of intrinsic Josephson junctions (IJJs) of Bi2_{2}Sr2_{2}CaCu2_{2}O8+x_{8+x} single crystals in the long-junction limit. Each sub-branch corresponds to a plasma mode in serially coupled Josephson junctions. Splitting into low-bias linear sub-branches with a spread in the slopes and the inter-sub-branch mode-switching character are in good quantitative agreement with the prediction of the weak but finite inter-junction capacitive-coupling model incorporated with the inductive coupling. This suggests the importance of the role of the capacitive coupling in accurately describing the vortex dynamics in serially stacked IJJs.Comment: 4 pages, 3 figures, 1 tabl

    Perspectives Provided by Leopard and Other Cat Genomes: How Diet Determined the Evolutionary History of Carnivores, Omnivores, and Herbivores

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    Recent advances in genome sequencing technologies have enabled humans to generate and investigate the genomes of wild species. This includes the big cat family, such as tigers, lions, and leopards. Adding the first high quality leopard genome, we have performed an in-depth comparative analysis to identify the genomic signatures in the evolution of felid to become the top predators on land. Our study focused on how the carnivore genomes, as compared to the omnivore or herbivore genomes, shared evolutionary adaptations in genes associated with nutrient metabolism, muscle strength, agility, and other traits responsible for hunting and meat digestion. We found genetic evidence that genomes represent what animals eat through modifying genes. Highly conserved genetically relevant regions were discovered in genomes at the family level. Also, the Felidae family genomes exhibited low levels of genetic diversity associated with decreased population sizes, presumably because of their strict diet, suggesting their vulnerability and critical conservation status. Our findings can be used for human health enhancement, since we share the same genes as cats with some variation. This is an example how wildlife genomes can be a critical resource for human evolution, providing key genetic marker information for disease treatment

    The Globular Cluster System of M60 (NGC 4649). I. CFHT MOS Spectroscopy and Database

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    We present the measurement of radial velocities for globular clusters in M60, giant elliptical galaxy in the Virgo cluster. Target globular cluster candidates were selected using the Washington photometry based on the deep 16\arcmin \times 16\arcmin images taken at the KPNO 4m and using the VIVI photometry derived from the HST/WFPC2 archive images. The spectra of the target objects were obtained using the Multi-Object Spectrograph (MOS) at the Canada-France-Hawaii Telescope (CFHT). We have measured the radial velocity for 111 objects in the field of M60: 93 globular clusters (72 blue globular clusters with 1.0(CT1)<1.71.0\le(C-T_1)<1.7 and 21 red globular clusters with 1.7(CT1)<2.41.7\le(C-T_1)<2.4), 11 foreground stars, 6 small galaxies, and the nucleus of M60. The measured velocities of the 93 globular clusters range from 500\sim 500 km s1^{-1} to 1600\sim 1600 km s1^{-1}, with a mean value of 107025+271070_{-25}^{+27} km s1^{-1}, which is in good agreement with the velocity of the nucleus of M60 (vgal=1056v_{\rm gal}=1056 km s1^{-1}). Combining our results with data in the literature, we present a master catalog of radial velocities for 121 globular clusters in M60. The velocity dispersion of the globular clusters in the master catalog is found to be 23414+13234_{-14}^{+13} km s1^{-1} for the entire sample, 22316+13223_{-16}^{+13} km s1^{-1} for 83 blue globular clusters, and 25831+21258_{-31}^{+21} km s1^{-1} for 38 red globular clusters.Comment: 29 pages, 8 figures. To appear in Ap
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