824 research outputs found

    A review and comparison of methodologies

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    Funding Information: This work received national funds through Fundação para a Ciência e Tecnologia (FCT) through the Research units CENSE “Center for Environmental and Sustainability Research”, (PTDC/CTA-AMB/6587/2020) and LAQV/REQUIMTE (UID/QUI/ 50006/2020). FCT is also acknowledged for J. Brinco (UI/BD/150867/2021) fellowship, and P. Guedes Contract established under Individual Call to Scientific Employment Stimulus (CEECIND/01969/2020). This research is anchored at RESOLUTION LAB, an infrastructure at NOVA School of Science and Technology. Funding Information: This work received national funds through Fundação para a Ciência e Tecnologia (FCT) through the Research units CENSE “Center for Environmental and Sustainability Research”, (PTDC/CTA-AMB/6587/2020) and LAQV/REQUIMTE (UID/QUI/ 50006/2020). FCT is also acknowledged for J. Brinco (UI/BD/150867/2021) fellowship, and P. Guedes Contract established under Individual Call to Scientific Employment Stimulus (CEECIND/01969/2020). This research is anchored at RESOLUTION LAB, an infrastructure at NOVA School of Science and Technology. Publisher Copyright: © 2023 The Author(s)This work reviews recently developed methodologies for multiclass pesticide residue analysis in soil and evaluates them under the focus of Green Analytical Chemistry principles, cost and time. Different extraction, clean-up and determination techniques are highlighted. QuEChERS was found to be the dominant form of extraction reported, although extractions using pressurized fluid, ultrasound and simple solid–liquid partitioning are still widely employed. GC–MS and LC-MS remain the standard analytical techniques, with the latter becoming more prevalent due to its greater versatility in analysing different chemical classes of pesticide residues, namely poorly volatile compounds. A selection of twelve representative methods was compared using the analytical eco-scale and AGREE metrics, as well as in terms of instrumental and operational cost, and time. The analysis shows that the choice of reagents and other operational parameters are more important towards the greenness of a method than the extraction and determination techniques used, but cost and time are more dependent on the techniques themselves.publishersversionpublishe

    Species pool structure determines the level of generalism of island parasitoid faunas

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    Copyright © 2011 Blackwell Publishing Ltd.AIM To examine whether island parasitoid faunas are biased towards generalists when compared with the mainland and their species pool, and to evaluate the effects of climate, island characteristics and regional factors on the relative proportions of idiobionts (i.e. generalists) and koinobionts (i.e. specialists) of two parasitic wasp families, Braconidae and Ichneumonidae. LOCATION Seventy-three archipelagos distributed world-wide. METHODS We used data on the distribution and biology obtained from a digital catalogue and several literature sources. We related level of generalism, measured as the ratio between the number of idiobiont and koinobiont species, to climatic, physiographic and regional factors using generalized linear models. We compared models by means of Akaike weighting, and evaluated the spatial structure of their residuals. We used partial regressions to determine whether the final models account for all latitudinal structure in the level of generalism. RESULTS Islands host comparatively more idiobionts than continental areas. Although there is a latitudinal gradient in the level of generalism of island faunas correlating with both environmental factors and island characteristics, the most important determinant of island community structure is their source pool. This effect is stronger for ichneumonids, where generalism is higher in the Indomalayan region, arguably due to the higher diversity of endophytic hosts in its large rain forests. MAIN CONCLUSIONS The level of generalism of island parasitoid faunas is largely constrained by regional factors, namely by the structure of the species pool, which emphasizes the importance of including regional processes in our understanding of the functioning of ecological communities. The fact that generalist species are more predominant in islands with a large cover of rain forests pinpoints the importance of the indirect effects of ecological requirements on community structure, highlighting the complex nature of geographical gradients of diversity

    Automated recognition of lung diseases in CT images based on the optimum-path forest classifier

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    The World Health Organization estimated that around 300 million people have asthma, and 210 million people are affected by Chronic Obstructive Pulmonary Disease (COPD). Also, it is estimated that the number of deaths from COPD increased 30% in 2015 and COPD will become the third major cause of death worldwide by 2030. These statistics about lung diseases get worse when one considers fibrosis, calcifications and other diseases. For the public health system, the early and accurate diagnosis of any pulmonary disease is mandatory for effective treatments and prevention of further deaths. In this sense, this work consists in using information from lung images to identify and classify lung diseases. Two steps are required to achieve these goals: automatically extraction of representative image features of the lungs and recognition of the possible disease using a computational classifier. As to the first step, this work proposes an approach that combines Spatial Interdependence Matrix (SIM) and Visual Information Fidelity (VIF). Concerning the second step, we propose to employ a Gaussian-based distance to be used together with the optimum-path forest (OPF) classifier to classify the lungs under study as normal or with fibrosis, or even affected by COPD. Moreover, to confirm the robustness of OPF in this classification problem, we also considered Support Vector Machines and a Multilayer Perceptron Neural Network for comparison purposes. Overall, the results confirmed the good performance of the OPF configured with the Gaussian distance when applied to SIM- and VIF-based features. The performance scores achieved by the OPF classifier were as follows: average accuracy of 98.2%, total processing time of 117 microseconds in a common personal laptop, and F-score of 95.2% for the three classification classes. These results showed that OPF is a very competitive classifier, and suitable to be used for lung disease classification

    Relato de implantação e utilização de uma instância do laboratório remoto VISIR em uma instituição brasileira

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    Considerando laboratórios remotos como ferramentas de potencial para disponibilizar práticas laboratoriais de uma maneira eficiente, percebe-se o crescimento no desenvolvimento dessas soluções, este é o caso do laboratório remoto VISIR, que disponibiliza práticas relacionadas aos conteúdos de circuitos elétricos e eletrônicos, devido às vantagens oferecidas este tipo de tecnologias tem sido replicada e implantada em diversas instituições. Este trabalho visa apresentar o relato de instalação e utilização de uma instância do laboratório remoto VISIR junto a recursos desenvolvidos para facilitar sua utilização, em uma instituição de ensino brasileira, a UFSC, proporcionado a compressão sobre o funcionamento da plataforma e sobre possíveis aplicações da mesma, demonstrando a flexibilidade em relação aos níveis de ensino que a ferramenta pode ser utilizada, bem como os conteúdos que podem ser abordados.info:eu-repo/semantics/publishedVersio

    Instructional materials in a STSE perspective: an analisys of units produced by secondary chemistry teachers in continuant formation

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    Some research has shown that teachers present conceptions that indicate a vision of teaching focused on memorization and transmission of knowledge and do not consider an approach that regards to the STSE aspects. The aim of this study is to investigate the conceptions of contextualization present in instructional materials produced by a group of chemistry secondary teachers. The data were collected in a service course offered to teachers of São Paulo Metropolitan area. One of the strategies of the course was the production of instructional units based on STSE (Science, Technology, Society and Environment) orientations. The data analysis takes into account: presence of problematization, its development throughout the unit; the relations established between experiments or text and the proposed theme, and the nature of information presented in the texts (scientific, social, technological, environmental). Four context profiles were built to characterize the 13 units elaborated by the teachers. Four of the teachers’ units revealed simple contextualization view profiles, although six of them revealed more complex profiles, compatible with STSE orientation

    Atividade tripanocida de flavonoides e limonoides isolados de extratos ativos de plantas de Myrsinaceae e Meliaceae

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    The activity of crude extracts of three Rapanea species (Myrsinaceae) and Cipadessa fruticosa (Meliaceae) was evaluated in vitro against the trypomastigote forms of Trypanosoma cruzi. Thirty-three extracts from different organs of these species were assayed and eleven of them showed significant activity (lysis % >50). The fractionation of an active extract from branches of R. lancifolia (99.5%) led to the isolation of two flavonoids: quercetin and taxifolin, which have weak trypanocidal activity. Additionally, one active extract from fruits of C. fruticosa (97.7%) afforded mexicanolide limonoids: cipadesin, mexicanolide, febrifugin and cipadesin A, that were slightly active on T. cruzi. Moreover, other two flavonoids (flavone and 7-methoxyflavone), previously assayed against T. cruzi, were isolated from the hexane extract from branches of C. fruticosa (100%). The results presented here suggest that the plants evaluated could be a source of new active compounds against T. cruzi.A atividade de extratos brutos de três espécies de Rapanea (Myrsinaceae) e de Cipadessa fruticosa (Meliaceae) foi avaliada in vitro contra formas tripomastigotas de Trypanosoma cruzi. Foram obtidos 33 extratos de diferentes órgãos das espécies estudadas, sendo que onze deles apresentaram atividades significantes (% de lise > 50) nos ensaios realizados. O fracionamento de um extrato ativo dos galhos de R. lancifolia (99,5%) resultou no isolamento de dois flavonoides (quercetina e taxifolina), que apresentaram baixa atividade tripanocida. De um extrato ativo dos frutos de C. fruticosa (97,7%) foram isolados os limonoides mexicanolídeos cipadesina, mexicanolídeo, febrifugina e cipadesina A, que foram moderadamente ativos sobre T. cruzi. Além disso, outros dois flavonoides (flavona e 7-metoxiflavona), previamente ensaiados contra T. cruzi, foram isolados do extrato hexânico dos galhos de C. fruticosa (100%). Os resultados obtidos aqui sugerem que as plantas avaliadas podem constituir fontes de novas substâncias ativas sobre o T. cruzi.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES)FINEP - Financiadora de Estudos e Projeto
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