69 resultados para Tetrapterys mucronata
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Antioxidant capacities of seven species of Passiflora were evaluated through comparation of the free radical DPPH scavenging activity. The studied species included cultivated and traditionally used P. edulis, P. incarnata and P. alata and less common species P. coccinea, P. laurifolia, P. mucronata and P. gardneri. The experimental design was completely randomized with ANOVA and Tukey test as main statistical analyses. The results showed that species of Passiflora had variable antioxidant capacities, ranging from 28 to 95% of free radical DPPH scavenging activity.
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Antioxidant capacities of seven species of Passiflora were evaluated through comparation of the free radical DPPH scavenging activity. The studied species included cultivated and traditionally used P. edulis, P. incarnata and P. alata and less common species P. coccinea, P. laurifolia, P. mucronata and P. gardneri. The experimental design was completely randomized with ANOVA and Tukey test as main statistical analyses. The results showed that species of Passiflora had variable antioxidant capacities, ranging from 28 to 95% of free radical DPPH scavenging activity.
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The genus Crotalaria is one of the largest within the family Leguminosae-Papilionoideae, with more than 600 species. However, few karyotypes have been described. In the present paper, five species belonging to the section Hedriocarpae were studied (subsection Machrostachyae), in order to better understand chromosomal evolution in Crotalaria. The results reveals that all species presented 2n = 2x = 16 with symmetrical karyotypes, and slight differences in the chromosome morphology. A secondary constriction was identified at short arm of the pair 1. The 45S rDNA was mapped in the secondary constriction and adjacent heterochromatin (NOR-heterochromatin) and a minor site was identified in C. ochroleuca. The 5S rDNA was mapped linked to 45S rDNA at chromosome 1 short arm in all species. Additional sites for 5S rDNA were identified in C. pallida, C. striata and C. mucronata. Heterochromatin blocks around the centromeres are not CMA(+) neither DAPI(+). The karyotypes of the subsection Macrostachyae are characterized by an inversion at chromosome pair one in relation to previous specialized floral species analyzed. Additional sites of 45S and 5S rDNA were assumed to be a result of transposition events by different ways. The results suggest heterochromatin differentiation and the position of ribosomal genes indicates chromosomal rearrangements during evolution. Karyotype characteristics corroborate the morphological infrageneric classification.
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This paper concentrates on the Early Oligocene palaeoclimate of the southern part of Eastern and Central Europe and gives a detailed climatological analysis, combined with leaf-morphological studies and modelling of the palaeoatmospheric CO2 level using stomatal and d13 C data. Climate data are calculated using the Coexistence Approach for Kiscellian floras of the Palaeogene Basin (Hungary and Slovenia) and coeval assemblages from Central and Southeastern Europe. Potential microclimatic or habitat variations are considered using morphometric analysis of fossil leaves from Hungarian, Slovenian and Italian floras. Reconstruction of CO2 is performed by applying a recently introduced mechanistic model. Results of climate analysis indicate distinct latitudinal and longitudinal climate patterns for various variables which agree well with reconstructed palaeogeography and vegetation. Calculated climate variables in general suggest a warm and frost-free climate with low seasonal variation of temperature. A difference in temperature parameters is recorded between localities from Central and Southeastern Europe, manifested mainly in the mean temperature of the coldest month. Results of morphometric analysis suggest microclimatic or habitat difference among studied floras. Extending the scarce information available on atmospheric CO2 levels during the Oligocene, we provide data for a well-defined time-interval. Reconstructed atmospheric CO2 levels agree well with threshold values for Antarctic ice sheet growth suggested by recent modelling studies. The successful application of the mechanistic model for the reconstruction of atmospheric CO2 levels raises new possibitities for future climate inference from macro-flora studies.
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Ostracodes are less common than might be normally expected at Sites 642, 643, and 644, perhaps pointing to the fact that the marine habitat below the overlying Pleistocene ice covers was a severe environment. This explanation, however, would not apply to the Pliocene and Miocene deposits from which ostracodes are just as poorly represented. In the latter case the Iceland-Faeroe Ridge might still have acted as a submerged barrier that did not allow an open ocean circulation of bottom waters. Thus the barrier presumably prevented an exchange of cold subarctic bottom water with that of the open Atlantic and therefore benthic deep-sea migration from the south was impeded. Some Quaternary species are, for the first time, recorded to extend to the Pliocene and/or Miocene.
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Up to now 19 species of Cladocera have been found in ponds of the Varanger Peninsula (Eastern Finnmark, Norway), which are presented here. A comparison with other regions in the northern Holarctic shows, that the limits of distribution of Cladocera mainly run parallel to latitudes. Using the number of Cladocera-species as an indicator, certain regions seem to be either favoured or unfavoured with respect to the climate in inland-waters. The Varanger Peninsula can be reckoned as a favoured region.
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The book is devoted to stratigraphy of Cretaceous deposits from high latitudes of the southern hemisphere (subantarctic part of the ocean), as well as to geological and climatic Cretaceous history of the area. Correlation with Cretaceous sediments from warm water regions is carried out. Description and photos of characteristic species of planktonic and benthic foraminifera and calcispherulides are given.