85 research outputs found

    Optical guided dispersions and subwavelength transmissions in dispersive plasmonic circular holes

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    The light transmission through a dispersive plasmonic circular hole is numerically investigated with an emphasis on its subwavelength guidance. For a better understanding of the effect of the hole diameter on the guided dispersion characteristics, the guided modes, including both the surface plasmon polariton mode and the circular waveguide mode, are studied for several hole diameters, especially when the metal cladding has a plasmonic frequency dependency. A brief comparison is also made with the guided dispersion characteristics of a dispersive plasmonic gap [K. Y. Kim, et al., Opt. Express 14, 320-330 (2006)], which is a planar version of the present structure, and a circular waveguide with perfect electric conductor cladding. Finally, the modal behavior of the first three TM-like principal modes with varied hole diameters is examined for the same operating mode.Comment: 20 pages, 5 figures, 1 tabl

    Susceptibility amplitude ratio for generic competing systems

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    We calculate the susceptibility amplitude ratio near a generic higher character Lifshitz point up to one-loop order. We employ a renormalization group treatment with LL independent scaling transformations associated to the various inequivalent subspaces in the anisotropic case in order to compute the ratio above and below the critical temperature and demonstrate its universality. Furthermore, the isotropic results with only one type of competition axes have also been shown to be universal. We describe how the simpler situations of mm-axial Lifshitz points as well as ordinary (noncompeting) systems can be retrieved from the present framework.Comment: 20 pages, no figure

    Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World.

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    Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites

    Transpiração e crescimento foliar de crisântemo em função da fração de água transpirável no substrato

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    The objective of this work was to evaluate the response of transpiration and leaf growth of chrysanthemum (Dendranthema grandiflorum) cultivars to available water in the substrate, represented by the fraction of transpirable substrate water (FTbSW). The experiments were performed in two periods, in a completely randomized design, with four chrysanthemum cultivars (Cherie White, Bronze Repin, Yoapple Valley, and Calabria), under two substrate water conditions (with or without water stress), with 10 replicates. Plants were grown in a greenhouse, in 2.8-L pots with substrate. FTSbW, transpiration, and leaf growth were measured daily, during the period of water deficit. The average threshold FTSbW, indicating that transpiration and leaf growth began to be affected, was respectively 0.63 and 0.68 for 'Cherie White', 0.60 and 0.69 for 'Bronze Repin', 0.53 and 0.59 for 'Yoapple Valley', and 0.51 and 0.54 for 'Calabria'. Available water decrease in the substrate reduces leaf growth before restricting transpiration. The Cherie White and Bronze Repin cultivars are more tolerant to water deficit by closing the stomata earlier and retaining more water in the substrate than the Yoapple Valley and Calabria cultivars.O objetivo deste trabalho foi avaliar a resposta da transpiração e do crescimento foliar de cultivares de crisântemo (Dendranthema grandiflorum) ao conteúdo de água disponível no substrato, representado pela fração de água transpirável no substrato (FATSb). Os experimentos foram realizados em dois períodos, em delineamento inteiramente casualizado, com quatro cultivares de crisântemo (Cherie White, Bronze Repin, Yoapple Valley e Calabria), em duas condições hídricas (com ou sem deficiência hídrica), com 10 repetições. As plantas foram cultivadas em casa de vegetação, em vasos de 2,8 L preenchidos com substrato. A FATSb, a transpiração e o crescimento foliar foram determinados diariamente durante o período de deficiência hídrica. As FATSb críticas médias, indicativas de que a transpiração e o crescimento foliar começam a ser afetados, foram respectivamente de 0,63 e 0,68 para 'Cherie White', 0,60 e 0,69 para 'Bronze Repin', 0,53 e 0,59 para 'Yoapple Valley', e 0,51 e 0,54 para 'Calabria'. A diminuição da água disponível no substrato provoca a redução do crescimento foliar antes de restringir a transpiração. As cultivares Cherie White e Bronze Repin são mais tolerantes ao deficit hídrico por fechar os estômatos antes e conservar mais a água no substrato do que as cultivares Yoapple Valley e Calabria
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