21 research outputs found
Secondary school studentsâ understanding of sampling variability
PID2019-105601GB-I00/AEI/10.13039/501100011033, Research group FQM-126
A remote sensing approach for regional-scale mapping of agricultural land-use systems based on NDVI time series.
In response to the need for generic remote sensing tools to support large-scale agricultural monitoring, we present a new approach for regional-scale mapping of agricultural land-use systems (ALUS) based on object-based Normalized Difference Vegetation Index (NDVI) time series analysis. The approach consists of two main steps. First, to obtain relatively homogeneous land units in terms of phenological patterns, a principal component analysis (PCA) is applied to an annual MODIS NDVI time series, and an automatic segmentation is performed on the resulting high-order principal component images. Second, the resulting land units are classified into the crop agriculture domain or the livestock domain based on their land-cover characteristics. The crop agriculture domain land units are further classified into different cropping systems based on the correspondence of their NDVI temporal profiles with the phenological patterns associated with the cropping systems of the study area. A map of the main ALUS of the Brazilian state of Tocantins was produced for the 2013-2014 growing season with the new approach, and a significant coherence was observed between the spatial distribution of the cropping systems in the final ALUS map and in a reference map extracted from the official agricultural statistics of the Brazilian Institute of Geography and Statistics (IBGE). This study shows the potential of remote sensing techniques to provide valuable baseline spatial information for supporting agricultural monitoring and for large-scale land-use systems analysis
The active metabolite of leflunomide, A77 1726, inhibits the production of prostaglandin E2, matrix metalloproteinase 1 and interleukin 6 in human fibroblastâlike synoviocytes
Objectives. To investigate the effects of the active metabolite of leflunomide, A77 1726, on fibroblastâlike synoviocytes. In rheumatoid arthritis (RA) synoviocytes participate in tissue destruction by producing metalloproteinases (MMP), prostaglandin E2 (PGE2) and interleukin (IL) 6, which are involved in extracellular matrix degradation, resorption of the mineral phase and osteoclastâmediated bone resorption. Methods. Human synoviocytes were stimulated with ILâ1α or tumour necrosis factor α (TNFâα) in the presence of A77 1726. Culture supernatants were analysed for production of interstitial collagenase (MMPâ1), tissueâinhibitor of metalloproteinases 1 (TIMPâ1), PGE2 and ILâ6. Total RNA was isolated and analysed for steadyâstate levels of MMPâ1, cyclooxygenaseâ2 (COXâ2) and ILâ6 mRNA. Results. A77 1726 inhibited the production of PGE2 in synoviocytes activated by TNFâα and ILâ1α with median inhibitory concentrations (IC50) of 7 and 3â”m respectively. In contrast, MMPâ1 and ILâ6 production was inhibited at high A77 1726 concentrations (> 10â”m), whereas TIMPâ1 was not affected. The inhibition of MMPâ1 and ILâ6 production was due to the known inhibitory effect of A77 1726 on pyrimidine synthesis, as it was reversed by the addition of uridine. This did not apply to PGE2 production, which was inhibited via direct action of A77 1726 on COXâ2, as shown by the increasing amount of substrate (arachidonic acid) in the culture medium. Conclusion. This study shows that some of the beneficial effect of leflunomide in RA patients may be due to the inhibition of PGE2, ILâ6 and MMPâ1 production in synoviocytes. This effect, coupled with its multiple inhibitory effects on T lymphocyte functions, might account for the significant reduction in the rate of disease progression in RA patients treated with leflunomid
AnĂĄlisis de la complejidad semiĂłtica y el contexto de las tablas estadĂsticas en los libros de texto españoles de secundaria
El objetivo del presente trabajo es analizar el nivel de complejidad semiĂłtica, junto con los contextos en que se plantean de los propuestos por PISA, en las tablas estadĂsticas incluidas en una muestra de 18 libros de texto españoles dirigidos a la educaciĂłn secundaria de tres editoriales diferentes. Para ello se realiza un anĂĄlisis de contenido del tema de estadĂstica y probabilidad en cada texto seleccionado. Los resultados muestran la complejidad creciente del tipo de tabla estadĂstica al avanzar el curso escolar, siendo la tabla de distribuciĂłn de una variable la mĂĄs frecuente, especialmente la que presenta frecuencias ordinarias. El contexto que aparece con mayor fuerza es el personal y se observa tambiĂ©n un incremento de tareas sin contexto, especialmente en el Ășltimo curso de secundaria
Sensoriamento remoto e anålise espacial: uma contribuição para o mapeamento dos sistemas integrados de produção agropecuåria.
No ano de 2009, o Governo do Brasil apresentou o Plano de Agricultura de Baixa Emissão de Carbono, cujo objetivo é a organização de açÔes para a adoção de tecnologias de produção de alimentos alinhadas aos compromissos de redução de emissÔes de GEE. Entre diversas pråticas destaca-se a implementação da integração lavoura-pecuåria (iLP). No entanto, a falta de procedimentos de monitoramento limita a governança do Plano. Os sistemas iLP podem ser adotados em duas abordagens distintas: Inter-anual e intra-anual. Este artigo tem como objetivo utilizar dados provenientes de sensoriamento remoto para identificar åreas de iLP na abordagem interanual no estado do Mato Grosso, na contribuição de um protocolo de monitoramento. Com o resultado, identificou-se que a implantação dos iLP tem seu auge em 2016 quando chega a 5% de toda årea de agricultura e pecuåria do estado do Mato Grosso
Molecular phylogenetic analysis of nuclear genes suggests a Cenozoic over-water dispersal origin for the Cuban solenodon
The Cuban solenodon (Solenodon cubanus) is one of the most enigmatic mammals and is an extremely rare species with a distribution limited to a small part of the island of Cuba. Despite its rarity, in 2012 seven individuals of S. cubanus were captured and sampled successfully for DNA analysis, providing new insights into the evolutionary origin of this species and into the origins of the Caribbean fauna, which remain controversial. We conducted molecular phylogenetic analyses of five nuclear genes (Apob, Atp7a, Bdnf, Brca1 and Rag1; total, 4,602 bp) from 35 species of the mammalian order Eulipotyphla. Based on Bayesian relaxed molecular clock analyses, the family Solenodontidae diverged from other eulipotyphlan in the Paleocene, after the bolide impact on the Yucatan Peninsula, and S. cubanus diverged from the Hispaniolan solenodon (S. paradoxus) in the Early Pliocene. The strikingly recent divergence time estimates suggest that S. cubanus and its ancestral lineage originated via over-water dispersal rather than vicariance events, as had previously been hypothesised
mafft-nexus-edge-trimmed-clean-50p_noPartitionTaxonsets
Nexus file for phylogenetic analyse