941 resultados para STRATA
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Some Upper Permian conchostracans from the Rio do Rasto Formation (Paraná Basin, South Brazil) have very characteristic recurved growth lines at the dorsal margin. All previously described specimens were classified as Palaeolimnadiopsis subalata (Reed) Raymond. However, a re-analysis of these fossils and of additional recently- collected specimens demonstrated that not all can be included in a single species, nor only in the Family Palaeolimnadiopseidae. According to their shape and the size of the umbo, they are classified into three species. The sub-elliptic carapaces with small anterior umbo are maintained in Palaeolimnadiopsis subalata (Reed, 1929) Raymond, 1946. The sub-circular carapaces with small sub-central umbo correspond to the new species Palaeolimnadiopsis riorastensis. The small size of the umbo is a character of the Family Palaeolimnadiopseidae. The small elliptic valves with large anterior umbo are assigned to the new species Falsisca brasiliensis of the Family Perilimnadiidae, which is characterized by large umbos. Palaeolimnadiopsis has a wide chronostratigraphic distribution, but Falsisca is restricted to the Upper Permian-Lower Triassic of Europe and Asia. This interval is in agreement with the probable Late Permian age of the respective strata of the Rio do Rasto Formation. Falsisca was not previously recorded in Gondwana.
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Conectivity between the hydrologic regimen and the distribution of the vegetation there is already a lot is recognized by several researchers in the works of fluvial ecology. It can be affirmed that the geomorphology of the alluvial plain has an important paper in the constitution of the riparian vegetation. On the proposed study, traverse topographical profiles were elaborated in the island, recognition of the distribution of the vegetation and the zoning geomorphologic presented in profiles for the Mutum Island. It's located in the upper course of the Parana River, between the mouth of the Paranapanema River and the mouth of the Ivinhema River. It elapses of this study the succession of the strata of the riparian vegetation and the relationship with the morphology of the surface, in this case the relief as the main controller abiotic and selective of the species in the environmental. For the whole island it was possible to define three classes: Mutum Upper Unit, Mutum Lower Unit and Paleochannel. The presented discussion is resulted partial of the project called Processes of Conectivity and the Riparian Vegetacion in the high course of the Parana River, PR/MS.
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This study was done to determine compactness of soil strata in the urban area of Bauru, central São Paulo State using standard penetration test (SPT) and seismic refraction methods. Frequency distribution within boreholes was measured every meter to a depth of 30 meters. The geometric mean of standard penetration test values was computed every meter. A biplot graph showing the relationship of SPT with depth indicates soil stratification. In addition, five sections of seismic refraction values, which also indicate the compactness of soil strata, were obtained. A comparison of the two methods shows significant correlation between the results obtained from each.
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Some species of bird are closely associated with bamboos (bamboo specialists) but community-wide studies comparing the avian assemblages in bamboo and non-bamboo habitats are lacking. Using point counts, we compared the species richness, abundance and composition of the avian assemblages in bamboo and non-bamboo habitats in the Brazilian Atlantic forest. Apart from considering bamboo specialists and non-specialist species, we contrasted birds from different categories of forest dependence, forest strata and diet. We recorded a total of 81 species of birds (74 in bamboo, 55 in non-bamboo habitats), including 15 bamboo specialists. Species richness was greater in bamboo habitats in all categories of diet and forest dependence. Bamboo and non-bamboo habitats had a similar number of canopy species, but bamboo habitats had a greater number of non-canopy species. The abundance of the whole avian community or of each of the dietary categories did not differ between habitats. The overall species composition differed between habitats, with a more homogeneous composition in non-bamboo habitats. A great number of species use bamboo habitats, even if they are not bamboo specialists. The initial expansion of bamboos, forming discrete patches of bamboo within mature forest, represents an intermediate-level disturbance that enhances forest heterogeneity and promotes the diversity of avian communities. © BirdLife Australia 2013.
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New material collected in Albian and Cenomanian strata from Brazil helps us to better understand the structure of a poorly known dasycladacean alga, Holosporella nkossaensis P. Masse, in Bull Centr Rech Explor-Prod elf aquitaine, 19: 301-317, 1995: each of its fertile laterals, which are regularly arranged in verticils along the cylindrical algal thallus, consists of a distally inXated primary bearing two vesicular ampullae in terminal position. These traits are not known in representatives of the genus Holosporella Pia, 1930 nor in any genera described to date. On this basis, we introduce the new genus Brasiliporella with Brasiliporella nkossaensis emend. nov. comb. as its typespecies. We also discuss the systematic aYnity of the new taxon: it is ascribed to the Tribe Batophoreae, and in a broader manner the current paleontological 'interpretation of the concept' (in French: 'acception') of the Order Dasycladales, with the creation of two new families and accordingly with the emendation of two other families. © Springer-Verlag Berlin Heidelberg 2012.
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In Brazil, the state of São Paulo contains both preserved areas (Juréia-Itatins Ecological Station) and extremely impacted ones (Cubatão Municipality). This study evaluated the concentrations of five metals (Cu, Cd, Cr, Pb, and Hg) in two mangroves with different levels of anthropogenic impact and the apparent genotoxicity to Ucides cordatus. Water and sediment samples were obtained, and metal concentrations were determined with an atomic absorption spectrophotometer. The genotoxic impact was quantified based on the number of micronucleated cells per 1,000 analyzed (MN‰), using hemolymph slides stained with Giemsa. Metal concentrations in water were below the detection limit, except for lead, although no significant difference was observed between the areas (P > 0.05). Sediment from Cubatão had higher concentrations of Cd, Pb, Cr, and Cu than sediment from Juréia-Itatins (P < 0.05), but no significant differences in metal concentrations were detected among depth strata of the sediment (P > 0.05). Crabs from Cubatão had a 2.6 times higher mean frequency of micronucleated cells (5.2 ± 1.8 MN‰) than those from Juréia-Itatins (2.0 ± 1.0 MN‰; P < 0.0001). The more-polluted conditions found in the mangrove sediments of Cubatão were reflected in the micronucleus assay, demonstrating their genotoxic effect; however, genetic damage should be attributed to a synergistic effect with other kinds of pollutants previously recorded in different environments of Cubatão. U. cordatus proved to be an excellent bioindicator of mangrove pollution. This study established, for the first time, the normal frequency of MN‰ in a population of this species within an ecological station. © 2013 Springer Science+Business Media Dordrecht.