5,115 research outputs found

    Does the anaesthetic influence behavioural transmission of the monogenean Gyrodactylus gasterostei Glaser, 1974 off the host?

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    The aim of this study was to investigate the use of the anaesthetic 2-phenoxyethanol on the transmission factors of gyrodactylid and to ascertain how this may affect in the colonisation of new hosts using the Gyrodactylus gasterostei Glaser, 1974 - Gasterosteus aculeatus L. model which is a simple and successful system to examine aspects of transmission of parasites from live and dead fish. Laboratory experiments include determining the maturity (presence of male copulate organ) and reproductive (presence of daughter) status of transmitting worms, in order to consider the factors that influence parasite option to migrate to a new individual of the same host species. This study demonstrates that parasites with a Male Copulate Organ (MCO) present are more likely to abandon the host and attempt a host transfer. The use of the anaesthetic 2-phenoxyethanol does not affect transmission of gyrodactylids which leave the host to colonise a new host. Finally, the use of other anaesthetic although its relative importance with respect to transmission remains uncertain.Department of the Environment, Food and Rural Affairs (Defra); Overseas Research Students Awards Scheme (ORSAS) UK; Consejo Nacional Ciencia y Tecnologia, Mexico CONACyT [171032]info:eu-repo/semantics/publishedVersio

    Tunnel spectroscopy in ac-driven quantum dot nanoresonators

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    Electronic transport in a triple quantum dot shuttle device in the presence of an ac field is analyzed within a fully quantum mechanical framework. A generalized density matrix formalism is used to describe the time evolution for electronic state occupations in a dissipative phonon bath. In the presence of an ac gate voltage, the electronic states are dressed by photons and the interplay between photon and vibrational sidebands produces current characteristics that obey selection rules. Varying the ac parameters allows to tune the tunneling current features. In particular, we show that coherent destruction of tunneling can be achieved in our device

    MS-288: Creation and Preservation of Martin Puryear’s Sentinel

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    This collection includes records from Gettysburg College’s application process to the NEA, the selection process of the artist, images from the installation process of Sentinel, correspondence and an interview with Martin Puryear, newspaper cutouts of Sentinel’s reception. As well as records from Molly Hutton’s efforts to seek awareness and funding for the preservation and conservation of Sentinel in the early 2000s. Records from the application for an assessment award under Save Outdoor Sculpture! (SOS!), and a manuscript for a story on Sentinel to be featured in the GETTYSBURG alumni magazine are also included. Special Collections and College Archives Finding Aids are discover tools used to describe and provide access to our holdings. Finding aids include historical and biographical information about each collection in addition to inventories of their contnet. More informaiton about our collections can be found on our website https://www.gettysburg.edu/special-collections/collections/.https://cupola.gettysburg.edu/findingaidsall/1223/thumbnail.jp

    Tunneling spectroscopy of the superconducting state of URu2Si2

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    We present measurements of the superconducting gap of URu2_2Si2_2 made with scanning tunneling microscopy (STM) using a superconducting tip of Al. We find tunneling conductance curves with a finite value at the Fermi level. The density of states is V shaped at low energies, and the quasiparticle peaks are located at values close to the expected superconducting gap from weak coupling BCS theory. Our results point to rather opened gap structures and gap nodes on the Fermi surface

    Radiative decay Z_H-> \gamma A_H in the little Higgs model with T-parity

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    In the little Higgs model with T-parity (LHTM), the only tree-level kinematically allowed two-body decay of the Z_H boson is Z_H-> A_H H and thus one-loop induced two-body decays may have a significant rate. We study the Z_H-> \gamma A_H decay, which is induced at the one-loop level by a fermion triangle and is interesting as it depends on the mechanism of anomaly cancellation of the model. All the relevant two- and three-body decays of the Z_H gauge boson arising at the tree-level are also calculated. We consider a small region of the parameter space where the scale of the symmetry breaking f is still allowed to be as low as 500 GeV by electroweak precision data. We first analyze the scenario of a Higgs boson with a mass of 120 GeV. We found that the Z_H->\gamma A_H branching ratio can be of the order of a tree-level three-body decay and may be at the reach of detection at the LHC for f close to 500 GeV, but it may be difficult to detect for f=1 TeV. There is also an scenario where the Higgs boson has an intermediate mass such that the Z_H-> A_H H decay is closed, the Z_H-> \gamma A_H gets considerably enhanced and the chances of detection get a large boost.Comment: 19 pages, 9 figures, 2 table

    Primera cita de Leptodactylus ocellatus (Linnaeus, 1758) (Amphibia, Anura, Leptodactylidae) en Bolivia y comentarios sobre especies próximas

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    The distributions of Leptodactylus ocellatus, L. chaquensis, and L. macrosternum in Bolivia are reviewed and discussed. Leptodactylus chaquensis and L. ocellatus are easily distinguished morphologically but L. chaquensis and L. macrosternum are indistinguishable. In Bolivia, L. ocellatus is known only from a single locality in the Paraguay River basin, which is reported here for the first time. Leptodactylus chaquensis occurs in the Chaco region of southeastern Bolivia, but it is unknown to what extent this species enters the Cerrado. The distribution boundaries and putative overlapping areas of L. chaquensis and L. macrosternum are unknown.Se revisa y discute la distribución de Leptodactylus ocellatus, L. chaquensis y L. macrosternum en Bolivia. Mientras que, morfológicamente, L. chaquensis y L. ocellatus se diferencian fácilmente, L. chaquensis y L. macrosternum son imposibles de distinguir. Leptodactylus ocellatus se encuentra en la parte boliviana de la cuenca del río Paraguay, aunque de momento se conoce solamente de una localidad, que se cita aquí por primera vez. Leptodactylus chaquensis habita en el Chaco, pero se deconoce hasta dónde penetra en el Cerrado. No se conocen los límites de las áreas de distribución y posibles zonas de solapamiento de L. chaquensis y L. macrosternum
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