999 resultados para Modelo Soft Soil


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Studying patterns of species distributions along elevation gradients is frequently used to identify the primary factors that determine the distribution, diversity and assembly of species. However, despite their crucial role in ecosystem functioning, our understanding of the distribution of below-ground fungi is still limited, calling for more comprehensive studies of fungal biogeography along environmental gradients at various scales (from regional to global). Here, we investigated the richness of taxa of soil fungi and their phylogenetic diversity across a wide range of grassland types along a 2800 m elevation gradient at a large number of sites (213), stratified across a region of the Western Swiss Alps (700 km(2)). We used 454 pyrosequencing to obtain fungal sequences that were clustered into operational taxonomic units (OTUs). The OTU diversity-area relationship revealed uneven distribution of fungal taxa across the study area (i.e. not all taxa are everywhere) and fine-scale spatial clustering. Fungal richness and phylogenetic diversity were found to be higher in lower temperatures and higher moisture conditions. Climatic and soil characteristics as well as plant community composition were related to OTU alpha, beta and phylogenetic diversity, with distinct fungal lineages suggesting distinct ecological tolerances. Soil fungi, thus, show lineage-specific biogeographic patterns, even at a regional scale, and follow environmental determinism, mediated by interactions with plants.

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Aquest treball vol implementar un projecte de mineria de dades en l'àrea de la petrologia ígnia, especialitat englobada dins la geologia clàssica.

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Aquest estudi té com a objectiu introduir el lector en dues tecnologies complementàries, XML i RDF. L'estudi mostra els inicis dels llenguatges de marcatge i explica perquè van ser concebuts.

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Telomerase activity (TA) is detected in most human cancers but, with few exceptions, not in normal somatic cells. Little is known about TA in soft tissue tumors. We have examined a series of benign and malignant soft tissue tumors for TA using the telomerase repeat amplification protocol assay. Analysis of the expression of the human telomerase reverse transcriptase was also carried out using RT-PCR. TA was undetectable in benign lesions (15 of 15) and low-grade sarcomas (6 of 6) and was detectable in 50% (19 of 38) of intermediate-/high-grade sarcomas. Although the presence of TA in soft tissue tumors is synonymous with malignancy, it is neither a reliable method in making the distinction between reactive/benign and malignant (especially low-grade) lesions nor a reliable marker of tumor aggressiveness. Leiomyosarcomas and storiform/pleomorphic malignant fibrous histiocytomas rarely showed TA, irrespective of their grade. A strong correlation between human telomerase reverse transcriptase mRNA expression and TA was observed, supporting the close relationship between both parameters. No significant relationship was observed between proliferative activity (as assessed by MIB-1 immunolabeling) and TA. We verified that the absence of telomerase expression was not due to the presence of telomerase inhibitors and therefore alternative mechanism(s) for cell immortalization, yet to be determined, seem to be involved in the development and/or maintenance of some soft tissue sarcomas.

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En els últims anys s'ha produït a Espanya un increment substancial de les revistes digitals de Documentació, tant de tipus acadèmic com merament informatiu o comercial. En la present comunicació, centrada en les revistes de tipus acadèmic, s'analitzen les existents, es realitza una proposta de definició i es presenta un model de revista.

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This article seeks to provide an in depth review about one of the most revolutionary and influential methods used in understanding the variables and processes that explain human health. Based on a new vision in the analysis of the consequences of theNazi Holocaust, a doctor-sociologist—Aaron Antonovsky— managed to influence medicine and behavioral science by facilitating the keys for the optimal development of public health today. Despite the fact that this theory began appearing in the1970s in the 20th century, its real development and expansion have been seen in recent years. In fact, in Spain, there is littlescientific literature that analyses the theoretic keys of the model in depth. This work seek to cover this gap; to achieve this objective, it first presents how the construct of salutogenesis arose, the social-cultural context that promoted it, as well as the importance public health acquires today. This is the aim of this work, which analyses the theoretical bases of the salutogenesis model,with specific emphasis on its background and precursors, aswell as its inception, development and current expansion