31 research outputs found

    Cetaceans of Venezuela: Their distribution and conservation status.

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    Sighting, stranding, and capture records of whales and dolphins for Venezuela were assembled and analyzed to document the Venezuelan cetacean fauna and its distribution in the eastern Caribbean. An attempt was made to confirm species identification for each of the records, yielding 443 that encompass 21 species of cetaceans now confirmed to occur in Venezuelan marine, estuarine, and freshwater habitats. For each species, we report its global and local distribution, conservation status and threats, and the common names used, along with our proposal for a Spanish common name. Bryde’s whale (Balaenoptera edeni) is the most commonly reported mysticete. The long-beaked common dolphin (Delphinus capensis) is the most frequent of the odontocetes in marine waters. The boto or tonina (Inia geoffrensis) was found to be ubiquitous in the Orinoco watershed. The distribution of marine records is consistent with the pattern of productivity of Venezuelan marine waters, i.e., a concentration at 63°07′W through 65°26′W with records declining to the east and to the west. An examination of the records for all cetaceans in the Caribbean leads us to conclude that seven additional species may be present in Venezuelan waters. (PDF file contains 61 pages.

    Bell State Preparation using Pulsed Non-Degenerate Two-Photon Entanglement

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    We report a novel Bell state preparation experiment. High-purity Bell states are prepared by using femtosecond pulse pumped \emph{nondegenerate} collinear spontaneous parametric down-conversion. The use of femtosecond pump pulse {\em does not} result in reduction of quantum interference visibility in our scheme in which post-selection of amplitudes and other traditional mechanisms, such as, using thin nonlinear crystals or narrow-band spectral filters are not used. Another distinct feature of this scheme is that the pump, the signal, and the idler wavelengths are all distinguishable, which is very useful for quantum communications.Comment: 4 pages, submitted to PR

    The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND)

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    The observation of neutrinoless double-beta decay (0νββ{\nu}{\beta}{\beta}) would show that lepton number is violated, reveal that neutrinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of \sim0.1 count /(FWHM\cdott\cdotyr) in the region of the signal. The current generation 76^{76}Ge experiments GERDA and the MAJORANA DEMONSTRATOR utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ{\nu}{\beta}{\beta} signal region of all 0νββ{\nu}{\beta}{\beta} experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76^{76}Ge experiment. The collaboration aims to develop a phased 0νββ{\nu}{\beta}{\beta} experimental program with discovery potential at a half-life approaching or at 102810^{28} years, using existing resources as appropriate to expedite physics results.Comment: Proceedings of the MEDEX'17 meeting (Prague, May 29 - June 2, 2017

    LEGEND-1000 Preconceptual Design Report

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    We propose the construction of LEGEND-1000, the ton-scale Large Enriched Germanium Experiment for Neutrinoless ββ\beta \beta Decay. This international experiment is designed to answer one of the highest priority questions in fundamental physics. It consists of 1000 kg of Ge detectors enriched to more than 90% in the 76^{76}Ge isotope operated in a liquid argon active shield at a deep underground laboratory. By combining the lowest background levels with the best energy resolution in the field, LEGEND-1000 will perform a quasi-background-free search and can make an unambiguous discovery of neutrinoless double-beta decay with just a handful of counts at the decay QQ value. The experiment is designed to probe this decay with a 99.7%-CL discovery sensitivity in the 76^{76}Ge half-life of 1.3×10281.3\times10^{28} years, corresponding to an effective Majorana mass upper limit in the range of 9-21 meV, to cover the inverted-ordering neutrino mass scale with 10 yr of live time

    The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND)

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    Scanning electron microscopy analysis of the antennal sensilla in therare saproxylic beetle Elater ferrugineus (Coleoptera: Elateridae)

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    This work provides the first morphological analysis (both at gross and fine level) of the antennal structures in the genusElater (Coleoptera, Elateridae). The typology, number and distribution patterns of the antennal sensilla in the rare saproxylicElater ferrugineus (both male and female) were studied using scanning electron microscopy (SEM). The serrate antennae ofE. ferrugineus consisted of a scape, a pedicel, and nine flattened flagellomeres. Overall, 10 types of sensilla were identifiedaccording to their morphological features: one type of sensilla chaetica (Ch), one type of Böhm sensilla (Bo), three types ofsensilla trichodea (Tr.1–3), two types of sensilla basiconica (Ba.1–2), one type of sensilla styloconica (St), one type ofgrooved peg sensilla (Gp) and one type of sensilla campaniformia (Ca). A marked sexual dimorphism was found at bothgross and fine scale. The male antenna was bigger (8.6 mm) than the female one (7.0 mm) and carried one type of sensillatrichodea (Tr.2) absent in female antennae possibly responsible for reception of the female-emitted sex pheromone. Thefemale antenna carried a higher number of sensilla (~ 9800) than the male one did (~7,000), with more abundant sensillachaetica (Ch) and basiconica (Ba.1 and Ba.2)
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