3,072 research outputs found

    A tale of two Bethe ans\"atze

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    We revisit the construction of the eigenvectors of the single and double-row transfer matrices associated with the Zamolodchikov-Fateev model, within the algebraic Bethe ansatz method. The left and right eigenvectors are constructed using two different methods: the fusion technique and Tarasov's construction. A simple explicit relation between the eigenvectors from the two Bethe ans\"atze is obtained. As a consequence, we obtain the Slavnov formula for the scalar product between on-shell and off-shell Tarasov-Bethe vectors.Comment: 28 pages; v2: 30 pages, added proof of (4.40) and (5.39), minor changes to match the published versio

    New species and synonymies in Hexoplonini Martins, 2006 (Coleoptera, Cerambycidae), with notes and new records on Cerambycinae Latreille, 1802

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    Glyptoscapus letiziae, a new species of Hexoplonini Martins, 2006, is described from Brazil (Minas Gerais). Glyptoscapus cicatricosus Aurivillius, 1899 and G. vanettii Martins, 1959 are synonymized with G. pallidulus (White, 1855). A key to species of Glyptoscapus is provided. New state records are presented for Thoracibidion io (Thomson, 1867) (Neoibidionini), Coleoxestia rafaeli Santos-Silva & Wappes, 2017 and C. denticornis (Gahan, 1892) (Cerambycini). The female of C. rafaeli is described for the first time

    Two new genera of Desmiphorini (Coleoptera, Cerambycidae, Lamiinae) with description of a species with non-retractile parameres

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    In this study, two new genera of Desmiphorini (Lamiinae) are proposed: Cleidaria gen. nov., to include Cleidaria cleidae sp. nov. from the state of Chiapas in Mexico, and Obscenoides gen. nov. for Desmiphora (D.) compta Martins & Galileo, 2005. The shape of tarsal claws of Cleidaria cleidae sp. nov. (abruptly narrowed from basal half) is so far, not found in any current genera of the tribe. With respect to Obscenoides compta (Martins & Galileo, 2005) comb. nov., the genitalia of males have an unusual shape with non-retractile parameres. The character combination related to this genital structure is unknown to us in other species in the family, and hypotheses about its function are suggested

    Predicción de la expansión hacia el norte de la distribución de una especie intermareal debido a alteraciones climáticas

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    Accurate distributional models can be used to reliably predict the response of organisms to climatic changes. Though such models have been extensively applied to terrestrial organisms, they have hardly ever been applied to the marine environment. Recent changes in the distribution of the marine gastropod Patella rustica (L.) were previously modelled with Classification and Regression Tree (CART) and the results revealed that increases in temperature were the major driver of those changes. However, the accuracy scores during the validation of the model were unsatisfactory, preventing its use for forecasting purposes. To fulfil this objective, in the present study a more robust method, Artificial Neural Network (ANN), was employed to produce a model suited to forecasting changes in the distribution of P. rustica. Results confirmed that the ANN model behaved better than the CART, and that it could be used for forecasting future distributional scenarios. The model forecasts that by the 2020s P. rustica is likely to expand its range at least 1000 km northwards. These results should be interpreted with caution considering the dispersal limitations of this species, but if such an expansion took place, major changes in the colonized ecosystems are expected due to the key role of limpets in intertidal communities.Los modelos de distribución de especies son una herramienta utilizada para predecir con exactitud la respuesta de organismos a las alteraciones climáticas. Aunque estos modelos han sido frecuentemente aplicados a organismos terrestres, casi nunca han sido aplicados en ambientes marinos. Estudios sobre la distribución del gasterópodo Patella rustica (L.) utilizando el método de árboles de clasificación y regresión (Classification and Regression Tree: CART) revelaron que el aumento de temperatura sería el principal impulsor de estos cambios. Sin embargo, la precisión de este modelo no permitió la predicción de la distribución de P. rustica en el siglo XXI. En el presente trabajo presentamos un método más robusto, las redes neuronales artificiales (Artificial Neural Networks: ANN), para producir un modelo adecuado que permita predecir futuros cambios en la distribución de P. rustica. Los resultados confirman que las ANN pueden ser utilizadas para la previsión de futuros escenarios de distribución y muestran que en la década de 2020 esta especie podría ampliar su rango de distribución al menos 1.000 kilómetros en dirección norte. Estos resultados deben ser interpretados teniendo en cuenta las limitaciones de dispersión de este organismo, pero si esa expansión se produce, se esperan grandes cambios en los ecosistemas debido al papel fundamental de las lapas en las comunidades intermareales

    New species and synonymies in Hexoplonini Martins, 2006 (Coleoptera, Cerambycidae), with notes and new records on Cerambycinae Latreille, 1802

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    Glyptoscapus letiziae, a new species of Hexoplonini Martins, 2006, is described from Brazil (Minas Gerais). Glyptoscapus cicatricosus Aurivillius, 1899 and G. vanettii Martins, 1959 are synonymized with G. pallidulus (White, 1855). A key to species of Glyptoscapus is provided. New state records are presented for Thoracibidion io (Thomson, 1867) (Neoibidionini), Coleoxestia rafaeli Santos-Silva & Wappes, 2017 and C. denticornis (Gahan, 1892) (Cerambycini). The female of C. rafaeli is described for the first time

    A new synonymy in Anisopodus White (Coleoptera, Cerambycidae, Lamiinae, Acanthocinini)

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    Anisopodus subarmatus Melzer, 1931 is synonymized with A. jaculus (Gyllenhal, 1817) and a discussion about the type-locality of the latter is provided. Photographs of the lectotype of the former and of the holotype of the latter are provided
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