952 resultados para Thematic composition or per species and chronological composition


Relevância:

100.00% 100.00%

Publicador:

Resumo:

En este artículo se estudia la biografía del emperador Trajano (98-117 DC) en la Estoria de Espanna de Alfonso X (capítulos 192-95). Siguiendo ciertos principios compositivos heredados de Suetonio (ya través de Vicente de Beauvais), la semblanza se articula por 'rúbricas' descriptivas (per species) o por orden narrativo y cronológico (per temporal, dando lugar a cuatro propiedades del discurso historiográfico alfonsí: falta de datación de los hechos, anulación de los marcos temporales establecidos para cada capítulo, narratividad de varios segmentos y unificación de los mismos por sus similaridades temáticas. En base a estas categorías, se estudiarán las varias líneas argumentales de la biografía: las campañas militares de Trajano contra germanos, dacios y partos, las insurrecciones contra Roma, los desastres naturales, las relaciones con los cristianos, las anécdotas y retratos de Trajano y su muerte y vida póstuma

Relevância:

100.00% 100.00%

Publicador:

Resumo:

En este artículo se estudia la biografía del emperador Trajano (98-117 DC) en la Estoria de Espanna de Alfonso X (capítulos 192-95). Siguiendo ciertos principios compositivos heredados de Suetonio (ya través de Vicente de Beauvais), la semblanza se articula por 'rúbricas' descriptivas (per species) o por orden narrativo y cronológico (per temporal, dando lugar a cuatro propiedades del discurso historiográfico alfonsí: falta de datación de los hechos, anulación de los marcos temporales establecidos para cada capítulo, narratividad de varios segmentos y unificación de los mismos por sus similaridades temáticas. En base a estas categorías, se estudiarán las varias líneas argumentales de la biografía: las campañas militares de Trajano contra germanos, dacios y partos, las insurrecciones contra Roma, los desastres naturales, las relaciones con los cristianos, las anécdotas y retratos de Trajano y su muerte y vida póstuma

Relevância:

100.00% 100.00%

Publicador:

Resumo:

En este artículo se estudia la biografía del emperador Trajano (98-117 DC) en la Estoria de Espanna de Alfonso X (capítulos 192-95). Siguiendo ciertos principios compositivos heredados de Suetonio (ya través de Vicente de Beauvais), la semblanza se articula por 'rúbricas' descriptivas (per species) o por orden narrativo y cronológico (per temporal, dando lugar a cuatro propiedades del discurso historiográfico alfonsí: falta de datación de los hechos, anulación de los marcos temporales establecidos para cada capítulo, narratividad de varios segmentos y unificación de los mismos por sus similaridades temáticas. En base a estas categorías, se estudiarán las varias líneas argumentales de la biografía: las campañas militares de Trajano contra germanos, dacios y partos, las insurrecciones contra Roma, los desastres naturales, las relaciones con los cristianos, las anécdotas y retratos de Trajano y su muerte y vida póstuma

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The effect of poultry species (broiler or turkey) and genotype (Wrolstad or BUT T8 turkeys and Ross 308 or Cobb 500 broilers) on the efficiency with which dietary longchain n-3 PUFA were incorporated into poultry meat was determined. Broilers and turkeys of both genotypes were fed one of six diets varying in FA composition (two replicates per genotype x diet interaction). Diets contained 50 g/kg added oil, which was either blended vegetable oil (control), or partially replaced with linseed oil (20 or 40 g/kg diet), fish oil (20 or 40 g/kg diet), or a mixture of the two (20 g linseed oil and 20 g fish oil/kg diet). Feeds and samples of skinless breast and thigh meat were analyzed for FA. Wrolstad dark meat was slightly more responsive than BUT T8 (P = 0.046) to increased dietary 18:3 concentrations (slopes of 0.570 and 0.465, respectively). The Ross 308 was also slightly more responsive than the Cobb 500 (P= 0.002) in this parameter (slopes of 0.557 and 0.449). There were no other significant differences between the genotypes. There was some evidence (based on the estimates of the slopes and their associated standard errors) that white turkey meat was more responsive than white chicken meat to 20:5 (slopes of 0.504 and 0.289 for turkeys and broilers, respectively). There was no relationship between dietary 18:3 n-3 content and meat 20:5 and 22:6 contents. If birds do convert 18:3 to higher FA, these acids are not then deposited in the edible tissues.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Benthic foraminiferal assemblages are a widespread tool to understand changes in organic matter flux and bottom-water oxygenation and their relation to paleoceanographic changes in the Upper Cretaceous oceans. In this study, assemblage data (diversity, total number, and number per species and gram) from Deep Sea Drilling Project (DSDP) Site 390 (Blake Nose, western North Atlantic) were processed for the lower Maastrichtian (Globotruncana falsostuarti - Gansserina gansseri Planktic Foraminiferal Zone). These data document significant changes in nutrient flux to the sea floor as well as bottom-water oxygenation during this time interval. Parallel to the observed changes in the benthic foraminiferal assemblages the number of inoceramid shells decreases, reflecting also a significant increase in bottom-water oxygenation. We speculate, that these data could reflect the onset of a shift from warmer low-latitude to cooler high-latitude deep-water sources. This speculation will predate the major reorganization of the oceanic circulation resulting in a circulation mode similar to today at the Early/Late Maastrichtian boundary by ~1 Ma and therefore improves our understanding of Late Cretaceous paleoceanography.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Observations of hummock and string-like microrelief features were made in High Arctic hydric meadows. Thermal shearing of thick bryophyte mats, and subsequent roll back during spring flooding appears to be one way in which this topography is formed. Hummocky and non-hummocky (flat) meadows show distinct floristic differences which may in part be due to observed differences in temperature, nutrient concentrations and moisture relations.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The spatial and temporal dynamics of seagrasses have been studied from the leaf to patch (100 m**2) scales. However, landscape scale (> 100 km**2) seagrass population dynamics are unresolved in seagrass ecology. Previous remote sensing approaches have lacked the temporal or spatial resolution, or ecologically appropriate mapping, to fully address this issue. This paper presents a robust, semi-automated object-based image analysis approach for mapping dominant seagrass species, percentage cover and above ground biomass using a time series of field data and coincident high spatial resolution satellite imagery. The study area was a 142 km**2 shallow, clear water seagrass habitat (the Eastern Banks, Moreton Bay, Australia). Nine data sets acquired between 2004 and 2013 were used to create seagrass species and percentage cover maps through the integration of seagrass photo transect field data, and atmospherically and geometrically corrected high spatial resolution satellite image data (WorldView-2, IKONOS and Quickbird-2) using an object based image analysis approach. Biomass maps were derived using empirical models trained with in-situ above ground biomass data per seagrass species. Maps and summary plots identified inter- and intra-annual variation of seagrass species composition, percentage cover level and above ground biomass. The methods provide a rigorous approach for field and image data collection and pre-processing, a semi-automated approach to extract seagrass species and cover maps and assess accuracy, and the subsequent empirical modelling of seagrass biomass. The resultant maps provide a fundamental data set for understanding landscape scale seagrass dynamics in a shallow water environment. Our findings provide proof of concept for the use of time-series analysis of remotely sensed seagrass products for use in seagrass ecology and management.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Investigations were carried out in wet and dry pasture. Coenological recordings were taken in three zones. The first zone (“A”) located 0-50 m near the stable, second zone (“B”) located 50-150 m from the stable, while the third zone (“C”) located farther than 150 m. We have carried out analyses of ecological and environmental factors and life form types. Based on our results for both dry and wet grasslands, quadrates of “A” zone were well isolated from the rest of the zones. Overgrazing, which involves considerable trampling, vanishes differences among vegetations, thereby promotes weed and disturbance tolerant rich vegetation. The lowest species number and diversity could be found here. Due to the nitrogen enrichment due to the constant presence of livestock, drier and less heat demanding habitat developed in the “A” zones, according to the environmental indicators. Because of the change in management, conservation and diversity values of “C” zone increased, however, according to nature protection values it underperformed compared to “B” zone. According to the sample area, wet grasslands from the sandy areas of Kiskunság, preserve nature protection values and grass composition better moving away from stables, due to less grazing pressure. Drier backgrounds tolerate stronger grazing pressure.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The assemblages inhabiting the continental shelf around Antarctica are known to be very patchy, in large part due to deep iceberg impacts. The present study shows that richness and abundance of much deeper benthos, at slope and abyssal depths, also vary greatly in the Southern and South Atlantic oceans. On the ANDEEP III expedition, we deployed 16 Agassiz trawls to sample the zoobenthos at depths from 1055 to 4930 m across the northern Weddell Sea and two South Atlantic basins. A total of 5933 specimens, belonging to 44 higher taxonomic groups, were collected. Overall the most frequent taxa were Ophiuroidea, Bivalvia, Polychaeta and Asteroidea, and the most abundant taxa were Malacostraca, Polychaeta and Bivalvia. Species richness per station varied from 6 to 148. The taxonomic composition of assemblages, based on relative taxon richness, varied considerably between sites but showed no relation to depth. The former three most abundant taxa accounted for 10-30% each of all taxa present. Standardised abundances based on trawl catches varied between 1 and 252 individuals per 1000 m2. Abundance significantly decreased with increasing depth, and assemblages showed high patchiness in their distribution. Cluster analysis based on relative abundance showed changes of community structure that were not linked to depth, area, sediment grain size or temperature. Generally abundances of zoobenthos in the abyssal Weddell Sea are lower than shelf abundances by several orders of magnitude.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The ADH (alcohol dehydrogenase) system is one of the earliest known models of molecular evolution, and is still the most studied in Drosophila. Herein, we studied this model in the genus Anastrepha (Diptera, Tephritidae). Due to the remarkable advantages it presents, it is possible to cross species with different Adh genotypes and with different phenotype traits related to ethanol tolerance. The two species studied here each have a different number of Adh gene copies, whereby crosses generate polymorphisms in gene number and in composition of the genetic background. We measured certain traits related to ethanol metabolism and tolerance. ADH specific enzyme activity presented gene by environment interactions, and the larval protein content showed an additive pattern of inheritance, whilst ADH enzyme activity per larva presented a complex behavior that may be explained by epistatic effects. Regression models suggest that there are heritable factors acting on ethanol tolerance, which may be related to enzymatic activity of the ADHs and to larval mass, although a pronounced environmental effect on ethanol tolerance was also observed. By using these data, we speculated on the mechanisms of ethanol tolerance and its inheritance as well as of associated traits.