2,199 research outputs found

    Structure of Gallobicchulite. A Combined EXAFS/Neutron Powder Diffraction Refinement

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    Abolishment of morphology‑based taxa and change to binomial species names: 2022 taxonomy update of the ICTV bacterial viruses subcommittee

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    This article summarises the activities of the Bacterial Viruses Subcommittee of the International Committee on Taxonomy of Viruses for the period of March 2021−March 2022. We provide an overview of the new taxa proposed in 2021, approved by the Executive Committee, and ratifed by vote in 2022. Signifcant changes to the taxonomy of bacterial viruses were introduced: the paraphyletic morphological families Podoviridae, Siphoviridae, and Myoviridae as well as the order Caudovirales were abolished, and a binomial system of nomenclature for species was established. In addition, one order, 22 families, 30 subfamilies, 321 genera, and 862 species were newly created, promoted, or moved

    Magnetic phase diagram of cubic perovskites SrMn_1-xFe_xO_3

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    We combine the results of magnetic and transport measurements with Mossbauer spectroscopy and room-temperature diffraction data to construct the magnetic phase diagram of the new family of cubic perovskite manganites SrMn_1-xFe_xO_3. We have found antiferromagnetic ordering for lightly and heavily Fe-substituted material, while intermediate substitution leads to spin-glass behavior. Near the SrMn_0.5Fe_0.5O_3 composition these two types of ordering are found to coexist and affect one another. The spin glass behavior may be caused by competing ferro- and antiferromagnetic interactions among Mn^4+ and observed Fe^3+ and Fe^5+ ions.Comment: 8 pages, 10 figures, revtex, accepted to Phys. Rev.

    Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System

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    The study of extra-solar planetary systems has emerged as a new discipline of observational astronomy in the past few years with the discovery of a number of extra-solar planets. The properties of most of these extra-solar planets were not anticipated by theoretical work on the formation of planetary systems. Here we report observations and light curve modeling of gravitational microlensing event MACHO-97-BLG-41, which indicates that the lens system consists of a planet orbiting a binary star system. According to this model, the mass ratio of the binary star system is 3.8:1 and the stars are most likely to be a late K dwarf and an M dwarf with a separation of about 1.8 AU. A planet of about 3 Jupiter masses orbits this system at a distance of about 7 AU. If our interpretation of this light curve is correct, it represents the first discovery of a planet orbiting a binary star system and the first detection of a Jovian planet via the gravitational microlensing technique. It suggests that giant planets may be common in short period binary star systems.Comment: 11 pages, with 1 color and 2 b/w Figures included (published version

    ‘Lest we forget’*: a veteran and son share a ‘warfare tourism’ experience

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    Warfare tourism’ represents an increasingly significant dimension of contemporary tourism. This paper provides a fresh perspective on participation in ‘warfare tourism’ by investigating the behaviour and experiences of a living veteran and his son returning to two theatres of war in which the veteran had served in the Royal Navy during the Second World War. Active interviews with the two family members were used to gather rich data regarding the two extended trips, which had been funded by ‘Heroes Return’, to Australia in 2012 and Sri Lanka in 2013. The findings indicate that some of the facets of visiting the fallen at other dark tourism sites, such as empathetic identification and personal connection, are also very relevant to trips shared between the living. However, with the living these contribute to a powerful co-created experience in which ‘closer’ bonds between the travellers can be developed. Furthermore, whilst the experiences at times represented ‘bitter-sweet’ nostalgia for the veteran, they also provided the son with the opportunity to ‘look through his father’s eyes’ from both a past and current perspective. Given that there will be war veterans as long as conflicts exist, the results have valuable messages for all those dealing with veterans in the futur

    Experiences Marketing: A Cultural Philosophy for Contemporary Hospitality Marketing Studies

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    This article explores the landscape of contemporary hospitality marketing. It is argued that the teaching and academic discussions that surround the subject area adopt a predominantly positivistic approach; although important, that does not adequately reflect the nature of the industry or the products offered. Such a metrics-oriented position, although significant in the formulation of marketing strategy, does not reflect the complex experiential, nontangible nature of the hospitality product. This article presents a culturally located philosophy that reflects the multifaceted nature of the industry. The philosophy is underpinned by three precepts that draw from a multidisciplinary theoretical framework to create a more subject-specific approach to marketing, that when woven with traditional approaches can create a more effective and informed contemporary approach

    Pollution, habitat loss, fishing and climate change as critical threats to penguins

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    Cumulative human impacts across the world’s oceans are considerable. We therefore examined a single model taxonomic group, the penguins (Spheniscidae), to explore how marine species and communities might be at risk of decline or extinction in the southern hemisphere. We sought to determine the most important threats to penguins and to suggest means to mitigate these threats. Our review has relevance to other taxonomic groups in the southern hemisphere and in northern latitudes, where human impacts are greater. Our review was based on an expert assessment and literature review of all 18 penguin species; 49 scientists contributed to the process. For each penguin species, we considered their range and distribution, population trends, and main anthropogenic threats over the past approximately 250 years. These threats were harvesting adults for oil, skin, and feathers and as bait for crab and rock lobster fisheries; harvesting of eggs; terrestrial habitat degradation; marine pollution; fisheries bycatch and resource competition; environmental variability and climate change; and toxic algal poisoning and disease. Habitat loss, pollution, and fishing, all factors humans can readily mitigate, remain the primary threats for penguin species. Their future resilience to further climate change impacts will almost certainly depend on addressing current threats to existing habitat degradation on land and at sea. We suggest protection of breeding habitat, linked to the designation of appropriately scaled marine reserves, including in the High Seas, will be critical for the future conservation of penguins. However, large-scale conservation zones are not always practical or politically feasible and other ecosystem-based management methods that include spatial zoning, bycatch mitigation, and robust harvest control must be developed to maintain marine biodiversity and ensure that ecosystem functioning is maintained across a variety of scales.Los impactos humanos acumulativos a lo largo de los océanos del planeta son considerables. Por eso examinamos un solo modelo de grupo taxonómico, los pingüinos (Sphenischidae), para explorar cómo las especies y las comunidades marinas pueden estar en riesgo de disminuir o de extinguirse en el hemisferio sur. Buscamos determinar la amenaza más importante para los pingüinos y sugerir métodos para mitigar estas amenazas. Nuestra revisión tiene relevancia para otros grupos taxonómicos en el hemisferio sur y en las latitudes norteñas, donde los impactos humanos son mayores. Nuestra revisión se basó en una evaluación experta y una revisión de literaratura de las 18 especies de pingüinos; 49 científicos contribuyeron al proceso. Para cada especie de pingüino, consideramos su rango y distribución, tendencias poblacionales y las principales amenazas antropogénicas en aproximadamente los últimos 250 años. Estas amenazas fueron la captura de adultos para obtener aceite, piel y plumas y el uso como carnada para la pesca de cangrejos y langostas: la recolección de huevos; la degradación del hábitat terrestre; la contaminación marina; la pesca accesoria y la competencia por recursos; la variabilidad ambiental y el cambio climático; y el envenenamiento por algas tóxicas y enfermedades. La pérdida de hábitat, la contaminación y la pesca, todos factores que los humanos pueden mitigar, siguen siendo las amenazas principales para las especies de pingüinos. Su resiliencia futura a más impactos por cambio climático dependerá certeramente de que nos enfoquemos en las amenazas actuales a la degradación de hábitats existentes en tierra y en el mar. Sugerimos que la protección de hábitats de reproducción, en conjunto con la designación de reservas marinas de escala apropiada, incluyendo alta mar, será crítica para la conservación futura de los pingüinos. Sin embargo, las zonas de conservación a gran escala no son siempre prácticas o políticamente viables, y otros métodos de manejo basados en ecosistemas que incluyen la zonificación espacial, la mitigación de captura accesoria, y el control fuerte de captura deben desarrollarse para mantener la biodiversidad marina y asegurar que el funcionamiento de los ecosistemas se mantenga a lo largo de una variedad de escalas.Fil: Trathan, Phil N.. British Antartic Survey; Reino UnidoFil: Garcia Borboroglu, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Boersma, P. Dee. University of Washington; Estados UnidosFil: Bost, Charles André. Centre d´Etudes Biologiques de Chizé; FranciaFil: Crawford, Robert J. M.. Department of Environmental Affairs; SudáfricaFil: Crossin, Glenn T.. Dalhousie University Halifax; CanadáFil: Cuthbert, Richard. Royal Society for the Protection of Birds; Reino UnidoFil: Dann, Peter. Phillip Island Nature Parks; AustraliaFil: Davis, Lloyd Spencer. University Of Otago; Nueva ZelandaFil: de la Puente, Santiago. Universidad Cayetano Heredia; PerúFil: Ellenberg, Ursula. University Of Otago; Nueva ZelandaFil: Lynch, Heather J.. Stony Brook University; Estados UnidosFil: Mattern, Thomas. University Of Otago; Nueva ZelandaFil: Pütz, Klemens. Antarctic Research Trust; AlemaniaFil: Seddon, Philip J.. University Of Otago; Nueva ZelandaFil: Trivelpiece, Wayne. Southwest Fisheries Science Center; Estados UnidosFil: Wienecke, Bárbara. Australian Antarctic Division; Australi

    Characterisation of Laser Wakefield Acceleration Efficiency with Octave Spanning Near-IR Spectrum Measurements

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    We report on high efficiency energy transfer in a GeV-class laser wakefield accelerator. Both the transfer of energy from the laser to the plasma wakefield, and from the plasma to the accelerated electron beam were diagnosed experimentally by simultaneous measurement of the deceleration of laser photons and the accelerated electrons as a function of acceleration length. The extraction efficiency, which we define as the ratio of the energy gained by the electron beam to the energy lost by the self-guided laser mode, was maximised at 27±227\pm2 % by tuning of the plasma density, plasma length and incident laser pulse compression. At higher densities, the laser was observed to fully redshift over an entire octave, from 800~nm to 1600~nm.Comment: 7 pages, 5 figure
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