300 research outputs found

    Spatial Factors Play a Major Role as Determinants of Endemic Ground Beetle Beta Diversity of Madeira Island Laurisilva

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    The development in recent years of new beta diversity analytical approaches highlighted valuable information on the different processes structuring ecological communities. A crucial development for the understanding of beta diversity patterns was also its differentiation in two components: species turnover and richness differences. In this study, we evaluate beta diversity patterns of ground beetles from 26 sites in Madeira Island distributed throughout Laurisilva – a relict forest restricted to the Macaronesian archipelagos. We assess how the two components of ground beetle beta diversity (βrepl – species turnover and βrich - species richness differences) relate with differences in climate, geography, landscape composition matrix, woody plant species richness and soil characteristics and the relative importance of the effects of these variables at different spatial scales. We sampled 1025 specimens from 31 species, most of which are endemic to Madeira Island. A spatially explicit analysis was used to evaluate the contribution of pure environmental, pure spatial and environmental spatially structured effects on variation in ground beetle species richness and composition. Variation partitioning showed that 31.9% of species turnover (βrepl) and 40.7% of species richness variation (βrich) could be explained by the environmental and spatial variables. However, different environmental variables controlled the two types of beta diversity: βrepl was influenced by climate, disturbance and soil organic matter content whilst βrich was controlled by altitude and slope. Furthermore, spatial variables, represented through Moran’s eigenvector maps, played a significant role in explaining both βrepl and βrich, suggesting that both dispersal ability and Madeira Island complex orography are crucial for the understanding of beta diversity patterns in this group of beetles.Peer reviewe

    Structural characterization of human Vaccinia-Related Kinases (VRK) bound to small-molecule inhibitors identifies different P-loop conformations

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    The human genome encodes two active Vaccinia-related protein kinases (VRK), VRK1 and VRK2. These proteins have been implicated in a number of cellular processes and linked to a variety of tumors. However, understanding the cellular role of VRKs and establishing their potential use as targets for therapeutic intervention has been limited by the lack of tool compounds that can specifically modulate the activity of these kinases in cells. Here we identified BI-D1870, a dihydropteridine inhibitor of RSK kinases, as a promising starting point for the development of chemical probes targeting the active VRKs. We solved co-crystal structures of both VRK1 and VRK2 bound to BI-D1870 and of VRK1 bound to two broad-spectrum inhibitors. These structures revealed that both VRKs can adopt a P-loop folded conformation, which is stabilized by different mechanisms on each protein. Based on these structures, we suggest modifications to the dihydropteridine scaffold that can be explored to produce potent and specific inhibitors towards VRK1 and VRK2

    Educação do campo nos governos FHC e Lula da Silva: potencialidades e limites de acesso à educação no contexto do projeto neoliberal

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    O artigo trata de uma análise sobre as contradições da política pública de educação do campo desencadeada em meio à luta pela Reforma Agrária por parte dos trabalhadores rurais frente ao projeto neoliberal do Governo Fernando Henrique Cardoso (1998-2002) e Governo Lula da Silva (2003-2010). A análise está pautada pela histórica resistência dos trabalhadores do campo na defesa da garantia do direito à educação pública de qualidade e o papel que os governos tiveram na estruturação de programas e de aprovação de marcos legais que acabaram por dar uma sustentação parcial às demandas. No entanto, como a Reforma Agrária não se materializou e o agronegócio continuou avançando no meio rural, a educação continua sendo a pauta importante dos movimentos sociais para que possam alimentar a esperança e conquistas contra o latifúndio, a exploração, o extermínio e a criminalização dos mais pobres

    Trophic dynamics of methylmercury and trace elements in a remote Amazonian Lake.

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    peer reviewedInformation on pollutant trophodynamics can be crucial for public health, as contaminated food consumption may lead to deleterious effects. This study was performed in Puruzinho Lake, a remote body of water in the Brazilian Amazon from which a riparian human population obtains an important part of its animal protein intake. Samples from 92 individuals, comprising 13 species and four trophic guilds (iliophagous, planktivorous, omnivorous, and piscivorous fish) were analysed for the determination of trace elements (Fe, Cr, Mn, Ni, Zn, Ca, Sr, Cd, Sn, Tl and Pb) and methylmercury concentrations. Samples from the same individuals had already been analysed for stable isotope (SI) measurements (δ13C and δ15N) in a previous investigation and the SI data have been statistically treated with those generated in this study for the evaluation of trophic dynamics of contaminants. Methylmercury was the only analyte that biomagnified, presenting TMF values of 4.65 and 4.55 for total and resident ichthyofauna, respectively. Trace elements presented either trophic dilution or independence from the trophic position, constituting a behaviour that was coherent with that found in the scientific literature. The similarity between Ni behaviour through the trophic web to that of essential elements contributes to the discussion on the essentiality of this metal to fish. Considering the Non-cancer Risk Assessment, the calculated Target Hazard Quotient (THQ) values were higher than 1.0 for all analysed individuals for methylmercury, as well as for only one individual for nickel. No other analyte rendered THQ values higher than 1.0.14. Life below wate

    The national inventory of geological heritage: methodological approach and results

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    A existência de um inventário nacional de património geológico é fundamental para se poderem implementar estratégias de geoconservação. Este trabalho apresenta a metodologia usada no desenvolvimento do mais completo inventário de geossítios, realizado até ao momento em Portugal, assim como os principais resultados obtidos. O inventário vai integrar o Sistema de Informação do Património Natural e o Cadastro Nacional dos Valores Naturais Classificados, ambos geridos pelo Instituto de Conservação da Natureza e da Biodiversidade.The existence of a national inventory of the geological heritage is of paramount importance for the implementation of a geoconservation strategy. This paper presents the methodological approach used to produce the most complete geosites inventory in Portugal, so far, and the obtained results. This inventory will be uploaded into the National Database of Natural Heritage managed by the Portuguese authority for nature conservation.Este trabalho é apoiado pela Fundação para a Ciência e a Tecnologia, através do financiamento plurianual do CGUP e do projecto de investigação “Identificação, caracterização e conservação do património geológico: uma estratégia de geoconservação para Portugal” (PTDC/CTE-GEX/64966/2006).info:eu-repo/semantics/publishedVersio

    Quality of life in liver transplant recipients and the influence of sociodemographic factors

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    Abstract OBJECTIVE To verify the influence of sociodemographic factors on the quality of life of patients after liver transplant. METHOD Cross-sectional study with 150 patients who underwent liver transplant at a referral center. A sociodemographic instrument and the Liver Disease Quality of Life questionnaire were applied. The analysis of variance (ANOVA) was performed, as well as multiple comparisons by the Tukey test and Games-Howell tests when p <0.05. RESULTS Old age had influence on domains of symptoms of liver disease (p = 0.049), sleep (p = 0.023) and sexual function (p = 0.03). Men showed better significant mean values than women for the loneliness dimension (p = 0.037). Patients with higher educational level had higher values for the domain of stigma of liver disease (p = 0.014). There was interference of income in the domains of quality of social interaction (p = 0.033) and stigma of the disease (p = 0.046). CONCLUSION In half of the quality of life domains, there was influence of some sociodemographic variable
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