396 research outputs found

    Scientific rationale for inclusion of a new nature complex Belyj Kolodez (Russia, Belgorod Region) into the emerald network

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    The article shows that there are resources for extending the national list of potential Areas of Special Conservation Interest (ASCI's) of the Emerald network in densely populated and old-developed regions. The representativeness of the Belyj Kolodez nature complex (Russia, Belgorod region) is substantiated. Based on the survey of the territory, the types of priority habitats were identified according to the EUNIR classificatio

    Principles and experience of justification of ecological representativeness of Emerald network potential sites

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    The article presents the results of the multi-method research to provide justification of Emerald network potential site, which meets the requirements of environmental representativeness. Flora and vegetation of the core natural habitat, species composition and prevalence of the species of European importance and from the Red books of the country and region, as well as the habitats of European importance were systematized with the use of methods of botanical and geobotanical studie

    Topological constraints on spiral wave dynamics in spherical geometries with inhomogeneous excitability

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    We analyze the way topological constraints and inhomogeneity in the excitability influence the dynamics of spiral waves on spheres and punctured spheres of excitable media. We generalize the definition of an index such that it characterizes not only each spiral but also each hole in punctured, oriented, compact, two-dimensional differentiable manifolds and show that the sum of the indices is conserved and zero. We also show that heterogeneity and geometry are responsible for the formation of various spiral wave attractors, in particular, pairs of spirals in which one spiral acts as a source and a second as a sink -- the latter similar to an antispiral. The results provide a basis for the analysis of the propagation of waves in heterogeneous excitable media in physical and biological systems.Comment: 5 pages, 6 Figures, major revisions, accepted for publication in Phys. Rev.

    Morphological variation of Astyanax species, subgenus Zygogaster (Teleostei, Characidae)

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    Astyanax es un género diverso de peces neotropicales, cuyas especies habitan gran variedad de ambientes acuáticos. La situación taxonómica de los subgéneros y de sus especies, no difiere de la problemática que presenta el género Astyanax. Basándonos en 354 individuos, se analizó la variación morfológica de cuatro especies del subgénero Zygogaster (A. atratoensis, A. caucanus, A. filiferus y A. magdalenae) mediante un análisis morfogeométrico comparado con dos especies del grupo hermano Poecilurichthys (A. orthodus y A. superbus). El ACP (Análisis de Componentes Principales) y AVC (Análisis de Variables Canónicas) evidenciaron afinidad morfológica entre los subgéneros e indicaron varianza en la profundidad del cuerpo, tendencia anterior del origen de la aleta dorsal y mancha humeral, depresión sobre la superficie dorsal del cráneo, y desplazamiento ventral de la orbita y el hocico. La variación entre las especies indicó aislamiento del tercer infraorbital del preopérculo y protrusión del extremo ventral del maxilar. La variación en estas estructuras evidencia especiación adaptativa como posible alternativa a la especiación por aislamiento geográfico. Palabras clave: Astyanax, Characido, Morfogeometría, Disparidad, Colombia.Astyanax es un género diverso de peces neotropicales, cuyas especies habitan gran variedad de ambientes acuáticos. La situación taxonómica de los subgéneros y de sus especies, no difiere de la problemática que presenta el género Astyanax. Basándonos en 354 individuos, se analizó la variación morfológica de cuatro especies del subgénero Zygogaster (A. atratoensis, A. caucanus, A. filiferus y A. magdalenae) mediante un análisis morfogeométrico comparado con dos especies del grupo hermano Poecilurichthys (A. orthodus y A. superbus). El ACP (Análisis de Componentes Principales) y AVC (Análisis de Variables Canónicas) evidenciaron afinidad morfológica entre los subgéneros e indicaron varianza en la profundidad del cuerpo, tendencia anterior del origen de la aleta dorsal y mancha humeral, depresión sobre la superficie dorsal del cráneo, y desplazamiento ventral de la orbita y el hocico. La variación entre las especies indicó aislamiento del tercer infraorbital del preopérculo y protrusión del extremo ventral del maxilar. La variación en estas estructuras evidencia especiación adaptativa como posible alternativa a la especiación por aislamiento geográfico. Palabras clave: Astyanax, Characido, Morfogeometría, Disparidad, Colombia.The diverse Neotropical fish genus Astyanax inhabits a variety of aquatic environments. As with other species in this genus, the taxonomic status and phylogenetic relationships of species of this subgenus remain largely undetermined. Based on 354 individuals, we analyzed the morphological variation of four species of the subgenus Zygogaster (A. atratoensis, A. caucanus, A. filiferus, and A. magdalenae) using procrustes analysis and compared findings with two species of the sister group: subgenus Poecilurichthys (A. orthodus y A. superbus). The PCA (Principal Component Analysis) and CVA (Canonical Variates Analysis) showed morphological affinity between the subgenera and indicated variance in body depth, anterior trend of dorsal fin origin and humeral spot, depression on the dorsal surface of the skull, and ventral displacement of the orbit and snout. The variation in these structures may provide evidence supporting adaptive speciation as an alternative to speciation driven by geographical isolation. Key words: Astyanax, Characid fish, Morphogeometry, Disparity, Colombia

    Variación morfológica de las especies de Astyanax, subgénero Zygogaster (Teleostei, Characidae)

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    Morphological variation of Astyanax species, subgenus Zygogaster (Teleostei, Characidae) The diverse Neotropical fish genus Astyanax inhabits a variety of aquatic environments. As with other species in this genus, the taxonomic status and phylogenetic relationships of species of this subgenus remain largely undetermined. Based on 354 individuals, we analyzed the morphological variation of four species of the subgenus Zygogaster (A. atratoensis, A. caucanus, A. filiferus, and A. magdalenae) using procrustes analysis and compared findings with two species of the sister group: subgenus Poecilurichthys (A. orthodus and A. superbus). The PCA (Principal Component Analysis) and CVA (Canonical Variates Analysis) showed morphological affinity between the subgenera and indicated variance in body depth, anterior trend of dorsal fin origin and humeral spot, depression on the dorsal surface of the skull, and ventral displacement of the orbit and snout. The variation in these structures may provide evidence supporting adaptive speciation as an alternative to speciation driven by geographical isolation

    The use of morphobiological characteristics in the selection of Phacelia Tanacetifolia Benth

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    The aim of the work is to create new adapted varieties resistant to the complex of biotic and abiotic factors on the basis of the use of Phacelia tanacetifolia Benth. morphological and biological characteristic

    Determination of number of sections in a gravity-flow flotation plant

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    A flow diagram for gas treatment of water contaminated with insoluble liquid impurities in an n-section gravity-flow flotation plant is examined. material-balance equations are presented for each section of the unit; simultaneous solution of these equations will permit determination of the ultimate design value of impurities in the treated water. An example is given for the calculation based on a given output of the flotation plant, the content of transformer oil in the initial water, and the cleaning efficiency of the water as a function of the water that enters a section. © 2013 Springer Science+Business Media New York
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