38 research outputs found

    Stryphnodendron adstringens (Mart.) Coville (Fabaceae) proanthocyanidins quantitation by RP-HPLC

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    Stryphnodendron adstringens (Mart.) Coville (barbatimão) is a tree belonging to the Fabaceae family, and it is commonly found in the southeastern Brazilian cerrado. The stem bark of this tree is traditionally used as an anti-inflammatory and antiseptic agent to treat leucorrhea and diarrhea, as well as to promote wound healing (owing to the presence of proanthocyanidins). Proanthocyanidins were obtained from the ethanolic extract of S. adstringens stem bark and assessed by reversed phase-high performance liquid chromatography with an ultraviolet/diode array detector. The identified compounds included gallic acid, catechin, gallocatechin (GC), epigallocatechin, and epigallocatechin gallate (EGCG). The selected markers, GC and EGCG, were simultaneously used for chromatographic validation (linearity range: 30-330 ng, equivalent to 3-33 µg/mL; r>;0.998). The method showed precision (intra-day relative standard deviation [RSD]: 1.72% for GC; 1.16% for EGCG; inter-day RSD: 1.74%-2.60% for both markers), accuracy, robustness, and selectivity. The limits of detection and quantitation were 0.29 µg/ml and 0.89 µg/ml for GC, and 0.88 µg/mL and 2.67 µg/mL for EGCG, respectively. In addition, S. obovatum was evaluated and showed an average of 12.2 µg/mL for GC (equivalent to 1.22% w/w) and 14.2 µg/mL for EGCG (equivalent to 1.42% w/w) in the ethanolic extract. The quantitative results were compared to those obtained for S. adstringens, which showed that the markers are present in both species.Stryphnodendron adstringens (Mart.) Coville (barbatimão) é uma árvore da família Fabaceae encontrada no cerrado do sudeste do Brasil. As cascas do caule das espécies são tradicionalmente utilizadas como agente antiinflamatório e antisséptico para o tratamento de diarreia e leucorreia, bem como para promover a cicatrização de feridas, devido à presença de proantocianidinas. Estas substâncias obtidas a partir do extracto etanólico (EE) de cascas do caule de S. adstringens foram avaliadas por cromatografia líquida de alta eficiência de fase reversa. As substâncias identificadas foram ácido gálico, catequina, galocatequina (GC), epigalocatequina e galato de epigalocatequina (EGCG). Os marcadores selecionados, GC e EGCG, foram utilizados simultaneamente para validação cromatográfica (intervalo de linearidade 30-330 ng, equivalente a 3-33 µg/mL, r>;0,998). O método mostrou precisão (intra-dia DPR 1,72% para GC; 1,16% para EGCG; inter-dia DPR 1,74%-2,60% para ambos os marcadores), exatidão, robustez e seletividade. Os limites de detecção e de quantificação de 0,29 µg/mL e 0,89 µg/mL para a GC, e 0,88 ng/mL e 2,67 µg/mL para EGCG, respectivamente. Outra espécie (S. obovatum) avaliada, mostrou valores médios 12,2 µg/mL de GC (equivalente a 1,22% p/p) e 14,2 µg/mL de EGCG (equivalente a 1,42% p/p) encontrados no EE. Os resultados quantitativos comparam-se aos de S. adstringens e mostram que tais marcadores estão presentes em ambas as espécies

    Busca harmônica aplicada à sintonia do regulador linear quadrático/ Harmonic search applied to the tuning of quadratic linear regulator

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    Este trabalho apresenta a aplicação do algoritmo de Busca Harmônica (Harmony Search - HS) na ponderação automática das matrizes Q e R do Regulador Linear Quadrático (Linear Quadratic Regulator - LQR) com Ação Integral. O projeto do LQR possui como principal obstáculo a dificuldade na ponderação das matrizes Q e R, sendo que, a busca adequada é de vital importância para que o controlador garanta as especificações do projeto. Para solucionar esta limitação, o presente artigo propõe o uso do HS, meta-heurística baseada em conceitos musicais, para a busca das melhores matrizes para o projeto LQR. O controlador foi otimizado usando HS e Algoritmo Genético (AG), e foi aplicado à planta do helicóptero militar CH-47B. Os resultados das simulações foram comparados e pôde-se constatar que algoritmo de Busca Harmônica obteve melhor desempenho, analisando o custo do controlador, índice de estabilidade, índice de tempo de estabilização e sinal de controle, quando comparado com o AG, uma abordagem mais tradicional para esse problema

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Stryphnodendron adstringens (Mart.) Coville (Fabaceae) proanthocyanidins quantitation by RP-HPLC

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    Stryphnodendron adstringens (Mart.) Coville (barbatimão) is a tree belonging to the Fabaceae family, and it is commonly found in the southeastern Brazilian cerrado. The stem bark of this tree is traditionally used as an anti-inflammatory and antiseptic agent to treat leucorrhea and diarrhea, as well as to promote wound healing (owing to the presence of proanthocyanidins). Proanthocyanidins were obtained from the ethanolic extract of S. adstringens stem bark and assessed by reversed phase-high performance liquid chromatography with an ultraviolet/diode array detector. The identified compounds included gallic acid, catechin, gallocatechin (GC), epigallocatechin, and epigallocatechin gallate (EGCG). The selected markers, GC and EGCG, were simultaneously used for chromatographic validation (linearity range: 30-330 ng, equivalent to 3-33 µg/mL; r>0.998). The method showed precision (intra-day relative standard deviation [RSD]: 1.72% for GC; 1.16% for EGCG; inter-day RSD: 1.74%-2.60% for both markers), accuracy, robustness, and selectivity. The limits of detection and quantitation were 0.29 µg/ml and 0.89 µg/ml for GC, and 0.88 µg/mL and 2.67 µg/mL for EGCG, respectively. In addition, S. obovatum was evaluated and showed an average of 12.2 µg/mL for GC (equivalent to 1.22% w/w) and 14.2 µg/mL for EGCG (equivalent to 1.42% w/w) in the ethanolic extract. The quantitative results were compared to those obtained for S. adstringens, which showed that the markers are present in both species
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