515 research outputs found

    Assessing the efficiency of protected areas to represent biodiversity : a small island case study

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    Protected areas (PAs) have been selected using either subjective or objective criteria applied to an extremely limited subset of biodiversity. Improved availability of species distribution data, better statistical tools to predict species distributions and algorithms to optimize spatial conservation planning allow many impediments to be overcome, particularly on small islands. This study analyses whether 219 species are adequately protected by PAs on Pico Island (theAzores, Portugal), and if they are as efficient as possible, maximizing species protection while minimizing costs. We performed distribution modelling of species’ potential distributions, proposed individual conservation targets (considering the context of each species in the archipelago and their current conservation status) to determine the efficiency of current PAs in meeting such targets and identify alternative or complementary areas relevant for conservation. Results showed that current PAs do not cover all taxa, leaving out important areas for conservation. We demonstrate that by using optimization algorithms it is possible to include most species groups in spatial conservation planning in the Azores with the current resources. With increasing availability of data and methods, this approach could be readily extended to other islands and regions with high endemism levels.info:eu-repo/semantics/publishedVersio

    Difference in Virulence of Mycobacterium avium Isolates Sharing Indistinguishable DNA Fingerprint Determined in Murine Model of Lung Infection

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    Background: Opportunistic Mycobacterium avium typically causes disease in immunocompromised patients and in some groups of apparently healthy individuals. the high virulence of some bacterial lineages increases the disease risk. High-resolution molecular genotyping studies of M. avium clinical isolates demonstrated that some genotype patterns were more prevalent than others, suggesting that close genetic relatedness of these successful isolates sharing a similar genotype could determine similar biological properties associated with high virulence.Methods and Findings: in this study, we aimed to compare the virulence and pathogenic properties of two epidemiologically unrelated M. avium isolates sharing an indistinguishable DNA fingerprint in a well-characterized model of pulmonary infection in mice, resistant or susceptible to mycobacteria. the mice, C57BL/6 wild-type or IFN-gamma gene disrupted (GKO), respectively, were intratracheally infected with two isolates, H27 (human blood isolate) and P104 (pig lymph node isolate), and the lungs were examined for bacterial loads, histopathology and cytokine gene expression. the obtained data demonstrated significant differences in the virulence properties of these strains. Although the H27 strain grew significantly faster than P104 in the early stage of infection, this bacterium induced protective immunity that started to reduce bacterial numbers in the wild-type mice, whereas the P104 strain established a chronic infection. in the GKO mice, both strains were capable of causing a chronic infection, associated with higher bacterial burdens and severe lung pathology, in a similar manner.Conclusions/Significance: the results demonstrated that the studied isolates differed in the pathogenic properties although were indistinguishable by actually widely used genotyping techniques demonstrating that the genotype similarity does not predict similarity in virulence of M. avium isolates.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Estadual Norte Fluminense, Lab Biol Recognit, Rio de Janeiro, BrazilUniv Estadual Norte Fluminense, Lab Anim Morphol & Pathol, Rio de Janeiro, BrazilInst Butantan, Lab Immunochem, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilFAPERJ: E-26/111.6111CNPq: 410555Web of Scienc

    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

    Recuperação de área degradada com sistema agroflorestal no Vale do Rio Doce, Minas Gerais.

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    O Vale do Rio Doce, MG, apresenta um histórico de ocupação e uso do solo que favorece a degradação ambiental, em que predominam pastagens sob o uso constante de queimadas. Os sistemas agroflorestais têm se mostrado eficientes na recuperação de áreas degradadas. Neste estudo foram avaliados os efeitos de um sistema agroflorestal na recuperação do solo em área degradada por pastagem na comunidade de Ilha Funda,Município de Periquito, Minas Gerais. A implantação do sistema se deu em 1994 e está sendo conduzido segundo os princípios agroecológicos, potencializando a regeneração natural e a sucessão de espécies. Em 1998, foram coletadas amostras de solo na área em recuperação e em duas áreas adjacentes: uma área degradada, que se encontrava em condições semelhantes às da área em recuperação no início do processo, e outra ocupada por pastagem. Foram determinados atributos químicos do solo e realizada a caracterização da matéria orgânica. O solo da área em recuperação com sistema agroflorestal mostrou-se em melhores condições do que o solo sob pastagem e o da área degradada, apresentando maior dinâmica do carbono orgânico e maior disponibilidade de nutrientes. Embora o teor de carbono orgânico total apresentado pelo solo sob pastagem tenha sido maior que nas demais condições avaliadas, o solo do sistema agroflorestal já está se igualando ao da pastagem no acúmulo das formas mais estáveis de carbono e apresentando maior dinâmica das frações orgânicas menos estáveis. Este estudo comprovou a eficiência dos sistemas agroflorestais, conduzidos segundo os princípios agroecológicos, na recuperação de áreas degradadas

    Avaliar a eficiência das áreas protegidas para representar a biodiversidade: o caso de estudo de uma pequena ilha

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    A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Nos Açores podem ser encontradas inúmeras espécies endémicas que tornam este arquipélago importante, do ponto de vista da conservação dos valores naturais. A rede de APs nos Açores está organizada em Parques Naturais de Ilha, no Parque Marinho dos Açores e em APs de importância local. O Parque Natural de Ilha (PNI) engloba diferentes categorias de áreas terrestres e marinhas, que possuem diferentes objectivos de conservação. No sentido de avaliar a adequação dos actuais limites das APs do ponto de vista da conservação das espécies, tendo a Ilha do Pico como caso de estudo, foram analisadas 219 espécies nativas dos Açores (briófitos, plantas vasculares, moluscos, artrópodes e vertebrados), na sua maioria endémicas. […].info:eu-repo/semantics/publishedVersio

    A Gene Expression Signature to Select Hepatocellular Carcinoma Patients for Liver Transplantation

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    Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.OBJECTIVE: To propose a new decision algorithm combining biomarkers measured in a tumor biopsy with clinical variables, to predict recurrence after liver transplantation (LT). SUMMARY BACKGROUND DATA: Liver cancer is one of the most frequent causes of cancer-related mortality. LT is the best treatment for hepatocellular carcinoma (HCC) patients but the scarcity of organs makes patient selection a critical step. Additionally, clinical criteria widely applied in patient eligibility decisions miss potentially curable patients while selecting patients that relapse after transplantation. METHODS: A literature systematic review singled out candidate biomarkers whose RNA levels were assessed by quantitative PCR in tumor tissue from 138 HCC patients submitted to LT (>5 y follow up, 32% beyond Milan criteria). The resulting four gene signature was combined with clinical variables to develop a decision algorithm using machine learning approaches. The method was named HepatoPredict. RESULTS: HepatoPredict identifies 99% disease-free patients (>5 y) from a retrospective cohort, including many outside clinical criteria (16%-24%), thus reducing the false negative rate. This increased sensitivity is accompanied by an increased positive predictive value (88,5%-94,4%) without any loss of long-term overall survival or recurrence rates for patients deemed eligible by HepatoPredict; those deemed ineligible display marked reduction of survival and increased recurrence in the short and long term. CONCLUSIONS: HepatoPredict outperforms conventional clinical-pathologic selection criteria, (Milan, UCSF) providing superior prognostic information. Accurately identifying which patients most likely benefit from LT enables an objective stratification of waiting lists and information-based allocation of optimal versus suboptimal organs.publishersversionepub_ahead_of_prin

    Susceptibility of neuron-like cells derived from bovine Wharton’s jelly to bovine herpesvirus type 5 infections

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    Background: Bovine herpesvirus type 5 (BoHV-5), frequently lethal in cattle, is associated with significant agricultural economic losses due to neurological disease. Cattle and rabbits are frequently used as models to study the biology and pathogenesis of BoHV-5 infection. In particular, neural invasion and proliferation are two of the factors important in BoHV-5 infection. The present study investigated the potential of bovine Wharton's jelly mesenchymal stromal cells (bWJ-MSCs) to differentiate into a neuronal phenotype and support robust BoHV-5 replication.Results: Upon inducing differentiation within a defined neuronal specific medium, most bWJ-MSCs acquired the distinctive neuronal morphological features and stained positively for the neuronal/glial markers MAP2 (neuronal microtubule associated protein 2), N200 (neurofilament 200), NT3 (neutrophin 3), tau and GFAP (glial fibrillary acidic protein). Expression of nestin, N200, beta-tubulin III (TuJI) and GFAP was further demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR). Following BoHV-5 inoculation, there were low rates of cell detachment, good cell viability at 96 h post-infection (p.i.), and small vesicles developed along neuronal branches. Levels of BoHV-5 antigens and DNA were associated with the peak in viral titres at 72 h p.i. BoHV-5 glycoprotein C mRNA expression was significantly correlated with production of progeny virus at 72 h p.i. (p < 0.05).Conclusion: The results demonstrated the ability of bWJ-MSCs to differentiate into a neuronal phenotype in vitro and support productive BoHV-5 replication. These findings constitute a remarkable contribution to the in vitro study of neurotropic viruses. This work may pave the way for bWJ-MSCs to be used as an alternative to animal models in the study of BoHV-5 biology
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