87 research outputs found

    The Prometheus Taxonomic Model: a practical approach to representing multiple classification.

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    A model for representing taxonomic data in a flexible and dynamic system capable of handling and comparing multiple simultaneous classifications is presented. The Prometheus Taxonomic Model takes as its basis the idea that a taxon can be circumscribed by the specimens or taxa of a lower rank which are said to belong to it. In this model alternative taxon concepts are therefore represented in terms of differing circumscriptions. This provides a more objective way of expressing taxonomic concepts than purely descriptive circumscriptions have been published. Using specimens as the fundamental elements of taxon circumscription also allows for the automatic naming of taxa based upon the distribution and priority of types within each circumscription, and by application of the International Code of Botanical Nomenclature. This approach effectively separates the process of naming taxa (nomenclature) from that of classification, and therefore enables the system to store multiple classifications. The derivation of the model, how it compares with other models, and the implications for the construction of global data sets and taxonomic working practice are discussed

    Dancing for Food in the Deep Sea: Bacterial Farming by a New Species of Yeti Crab

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    Vent and seep animals harness chemosynthetic energy to thrive far from the sun's energy. While symbiont-derived energy fuels many taxa, vent crustaceans have remained an enigma; these shrimps, crabs, and barnacles possess a phylogenetically distinct group of chemosynthetic bacterial epibionts, yet the role of these bacteria has remained unclear. We test whether a new species of Yeti crab, which we describe as Kiwa puravida n. sp, farms the epibiotic bacteria that it grows on its chelipeds (claws), chelipeds that the crab waves in fluid escaping from a deep-sea methane seep. Lipid and isotope analyses provide evidence that epibiotic bacteria are the crab's main food source and K. puravida n. sp. has highly-modified setae (hairs) on its 3rd maxilliped (a mouth appendage) which it uses to harvest these bacteria. The ε- and γ- proteobacteria that this methane-seep species farms are closely related to hydrothermal-vent decapod epibionts. We hypothesize that this species waves its arm in reducing fluid to increase the productivity of its epibionts by removing boundary layers which may otherwise limit carbon fixation. The discovery of this new species, only the second within a family described in 2005, stresses how much remains undiscovered on our continental margins

    The Lesser Known Challenge of Climate Change: Thermal Variance and Sex-Reversal in Vertebrates with Temperature-Dependent Sex Determination

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    Climate change is expected to disrupt biological systems. Particularly susceptible are species with temperature-dependent sex determination (TSD), as in many reptiles. While the potentially devastating effect of rising mean temperatures on sex ratios in TSD species is appreciated, the consequences of increased thermal variance predicted to accompany climate change remain obscure. Surprisingly, no study has tested if the effect of thermal variance around high-temperatures (which are particularly relevant given climate change predictions) has the same or opposite effects as around lower temperatures. Here we show that sex ratios of the painted turtle (Chrysemys picta) were reversed as fluctuations increased around low and high unisexual mean-temperatures. Unexpectedly, the developmental and sexual responses around female-producing temperatures were decoupled in a more complex manner than around male-producing values. Our novel observations are not fully explained by existing ecological models of development and sex determination, and provide strong evidence that thermal fluctuations are critical for shaping the biological outcomes of climate change

    Abstracts of presentations on plant protection issues at the fifth international Mango Symposium Abstracts of presentations on plant protection issues at the Xth international congress of Virology: September 1-6, 1996 Dan Panorama Hotel, Tel Aviv, Israel August 11-16, 1996 Binyanei haoma, Jerusalem, Israel

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    General Introduction Definition of the Delta Format

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    This document is primarily for the benefit of programmers, and contains more detail than would usuall

    Sinopse das espécies neotropicais do grupo brasiliensis do gênero Apenesia (Hymenoptera, Bethylidae) Synopsis of neotropical species of brasiliensis group genus Apenesia (Hymenoptera, Bethylidae)

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    São descritas e ilustradas Apenesia longa sp. nov., A. peccata sp. nov., A. magna sp. nov., A. permaxima sp. nov., A. perconcava sp. nov. e A. recta sp. nov. da região Neotropical. São adicionados dados novos de variações estruturais e distribuição geográfica de A. transversa Evans, 1963, A. spinipes Evans, 1969, A. tlahuicana Evans, 1963, A. triangula Azevedo & Batista, 2002, A. megaventris Azevedo & Batista, 2002, A. venezuelana Evans, 1963, A. acia Lanes & Azevedo, 2004 e A. ventosa Azevedo & Batista, 2002. Duas sinonímias novas são propostas: A. peruana Evans, 1963 como sinônimo junior de A. brasiliensis (Kieffer, 1910); A. subangulata Azevedo & Batista, 2002 como sinônimo junior de A. fulvicollis (Westwood, 1874), esta ultima considerada dentro ao grupo nitida. É fornecida uma chave de identificação para as espécies do grupo, baseada em machos.<br>Apenesia longa sp. nov., A. peccata sp. nov., A. magna sp. nov., A. permaxima sp. nov., A. perconcava sp. nov., and A. recta sp. nov., from Neotropical region are described and illustrated. Additional material of A. transversa Evans, 1963, A. spinipes Evans, 1969, A. tlahuicana Evans, 1963, A. triangula Azevedo & Batista, 2002, A. megaventris Azevedo & Batista, 2002, A. venezuelana Evans, 1963, A. acia Lanes & Azevedo, 2004 and A. ventosa Azevedo & Batista, 2002 had their structural variations and known distribution broadened. Two new synonyms are proposed: A. peruana Evans, 1963 as junior synonym of A. brasiliensis (Kieffer, 1910); A. subangulata Azevedo & Batista, 2002 as junior synonym of A. fulvicollis (Westwood, 1874), and the latter considered in the nitida group. An identification key to species of the group based on males is provided

    BEYOND HYPERTAXONOMY

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