3,967 research outputs found

    Water erosion in a Yellow-Red Ultisol under different patterns of simulated rain

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    Visou-se, neste trabalho, determinar as perdas de solo, água e nutrientes em um Argissolo Vermelho-Amarelo submetido a quatro diferentes padrões de chuva simulada. O estudo foi conduzido no Campo Experimental da Embrapa-Agrobiologia, localizado no município de Seropédica, RJ, e consistiu na aplicação de chuvas simuladas com diferentes padrões caracterizados como avançado (AV), intermediário (IN), atrasado (AT) e constante (CT), em uma área amostral de 0,80 m de largura por 1,0 m de comprimento. As chuvas tiveram duração de 60 min com uma lâmina total aplicada de 30 mm e um pico de 110 mm h-1, para os padrões de intensidade variável. Os resultados obtidos possibilitaram concluir que após 60 min de chuva simulada as perdas de solo e água observadas para o padrão atrasado foram, em média, superiores em 61,6, 46,4 e 13,6%, respectivamente, para o CT, AV e IN (solo), e de 42,0, 19,0 e 19,0%, respectivamente, para o AV, IN e CT (água) e as perdas de nutrientes não diferiram entre os padrões de precipitação, sendo mais influenciadas pelas perdas de água escoada superficialmente que pelo material sólido em suspensão.This study was carried out in order to determine the soil, water and nutrient losses in a Yellow-Red Ultisol, under four different patterns of simulated rainfall. The experiment was conducted at the Embrapa Agrobiologia experimental field, located in the municipality of Seropédica, Rio de Janeiro, Brazil. The study consisted in the application of simulated rains using variable rainfall intensity classified in different patterns as: advanced (AD), intermediate (IN), delayed (DE), and constant (CT), in plots 0.8 m wide and 1.0 m long. The rain had a duration of 60 min, with a total applied depth of 30 mm, and a peak of 110 mm h-1, for the variable intensity patterns. With the results obtained it was possible to verify that after 60 min of simulated DE pattern provided losses higher than CT, AD and IN, in 61.6, 46.4 and 13.6%, respectively (soil), and 42.0, 19.0 and 19.0% (run-off), respectively, for the AD, IN and CT patterns; and the nutrients losses did not differ among the rainfall patterns, being more affected by water run-off than solid material in suspension

    Dose-dependent protective and inductive effects of xanthohumol on oxidative DNA damage in Saccharomyces cerevisiae

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    The effect of xanthohumol, a prenylflavonoid isolated from the hop plant (Humulus lupulus L.), on Saccharomyces cerevisiae DNA oxidative damage and viability was evaluated. Yeast cultures under oxidative stress, induced by H2O2, displayed stronger growth in the presence of 5 mg/L of xanthohumol than cultures with only H2O2. Likewise, DNA damage assessed by the comet assay was significantly lower in cells co-incubated with xanthohu- mol and H2O2. Accordingly, fluorescence of dichlorofluorescein in cells treated with H2O2 and xanthohumol was considerably lower than in cells exclusively treated with H2O2, in- dicative of a reactive oxygen species scavenging mechanism and consequent formation of oxidation products, as detected by mass spectrometry. However, at concentrations above 5 mg/L, xanthohumol elicited an opposite effect, leading to a slower growth rate and signifi- cant increase in DNA damage. A yeast yap1 deletion mutant strain sensitive to oxidative stress grew more slowly in the presence of at least 5 mg/L of xanthohumol than cultures of the wild type, suggesting that xanthohumol toxicity is mediated by oxidative stress. This evidence provides further insight into the impact of xanthohumol on yeast cells, support- ing dose-dependent antioxidant/antigenotoxic and prooxidant/genotoxic effects.This work was funded by FEDER through the Operational Programme for Competitiveness Factors – COMPETE and by National Funds through FCT – Foundation for Science and Technology, under the projects UID/ QUI/50006/2013 and NORTE-07-0124-FEDER-000069. DC wishes to acknowledge FCT for his PhD studentship (SFRH/BD/79939/2011). BJ acknowledges the support of FCT through project PTDC/AAC-AMB/120940/2010 'MYCOFAT'. DC wishes to acknowledge FCT for his PhD studentship (SFRH/BD/79939/2011). We thank Martin Biendl, from Hopsteiner (New York, NY, USA), for donating the xanthohumol and Cristina Ribeiro for help in fl ow cytometry analyses. Mass spectrometry analyses were conducted at CEMUP (Materials Centre of the University of Porto, Portugal).info:eu-repo/semantics/publishedVersio

    Reference Structure Model for Degree Alert Classification During Seasonal Hydrological Events for Humanitarian Assistence in the Brazilian Amazon

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    AbstractRecent events in the rivers of the Amazon region show the distinct need for concern in this region and the vulnerability of the Amazonian people in regards to these events. Organizations for humanitarian aid developed procedures in the Amazon region. But to what extent are these actions effective if little is done prior to disasters? This work seeks to develop a frame of reference for classifying alertness in cities likely to suffer from flooding and ebbing of the hydrographic network in the Amazon Basin. The objective is to serve warning to the riverside communities in the state of Amazonas, establish future provisions of supplies and to form a solid database of information concerning the needs and impacts of these events, hence creating a historical record

    Brewer’s spent grains protects against oxidative DNA damage in Saccharomyces cerevisiae

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    Brewer’s spent grain (BSG), obtained from barley malt during brewing, contains high amounts of phenolic acids, predominantly ferulic and p-coumaric acids. The protective effects of BSG extracts against oxidative DNA damage induced by H2O2 in Saccharomyces cerevisiae cells were investigated using an optimized yeast comet assay and flow cytometry. The results indicated that BSG extracts from black malt exhibited a 5-fold reduction in the genotoxic effects of H2O2, compared to the 2-fold decrease by the BSG extracts from pilsen malts. Flow cytometry analysis with dichlorofluorescein diacetate demonstrated that the intracellular oxidation of S. cerevisiae is also reduced to approximately 50% in the presence of 20-fold diluted BSG extracts. BSG extracts obtained from pilsen and black malt types exert dose-dependent protective properties against the genotoxic effects induced by ROS and decrease intracellular oxidation of yeast cells.This work received financial support from the European Union (FEDER Funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e a Tecnologia) through project Pest-C/EQB/LA0006/2013 and PEst-C/BIA/UI4050/2011. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124-FEDER-000069. DOC receives a postdoc grant through the project Operação Norte-01-0145-FEDER-000011. MMM wishes to acknowledge to FCT for her postdoctoral grant (SFRH/BPD/97049/2013). The authors also thank Unicer – Bebidas de Portugal, S. A. for the supply of BSG samples.info:eu-repo/semantics/publishedVersio

    A New Environmentally Safe Formulation and of Low Cost for Prolonged Release System of Atrazine and Diuron

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    Diuron and atrazine were incorporated in new formulations developed with the purpose to improve herbicides action through release systems, as well as to reduce the environmental toxicity. A low cost formulation (ALG/ESC) was obtained by combining sodium alginate (ALG) with fish scales of the Piau fish (ESC) from the Leporinus elongatus species. From the crosslinking of ALG/ESC with CaCl2, the formulation ALG/ESC-CaCl2 was obtained. For ALG/ESC-CaCl2, the results are successful, showing a prolonged release of 3.5 and 4.5 days for atrazine and diuron, respectively. Based on parameters of an empirical equation used to fit the herbicide release data, it appears that the release systems of diuron and atrazine from ALG/ESC-CaCl2 are by diffusion processes due to anomalous transport, which did not follow Fick’s laws of diffusion. DOI: http://dx.doi.org/10.17807/orbital.v9i3.99

    Gone With the Water: The Loss of Genetic Variability in Black and Gold Howler Monkeys (Alouatta caraya) Due to Dam Construction

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    Black and gold howler monkeys (Alouatta caraya) inhabit several eco-regions in South America with the highest population densities in riverine forests. Dam construction for electricity production represents a severe human alteration of ecosystems with consequences for primate conservation. To evaluate the possible loss of genetic diversity in A. caraya, we analysed and compared the genetic structure of the species across 22 study sites in Argentina (14), Paraguay (1), and Brazil (7). Four of these study sites (referred to as flooded) were sampled before dam-linked flooding which most likely caused a drastic decline or functional extinction of these populations. The genetic variability of 256 individuals was evaluated using 10 autosomal microsatellites (STRs) and 112 individuals by sequencing a fragment of 507 bp of mtDNA. DNA was extracted from tissue, blood, and faecal samples. Significantly higher values of genetic variability were observed for the flooded populations both in mtDNA and STRs. Population genetic structure showed a K = 1, 2, or 5 depending on the method, separating Argentinian and Paraguayan sites from Brazilian sites and, in the case of K = 5, two clusters were mostly represented by flooded populations. Isolation-by-distance analyses showed that geographic distances influence gene flow. Analytical methods, such as Pairwise Fst’s and Nei’s and regression model of Harpending and Ward, were concordant in detecting significant genetic structuring between flooded and remaining sites examined. Although some sites have very low sample sizes, these samples are of great importance since these sampling sites are currently flooded. Our results show that the study sites where dams were built had the greatest genetic diversity. As A. caraya is currently severely threatened by yellow fever outbreaks, the remaining populations may be more vulnerable to disease outbreaks due to impoverished genetic variability. Accordingly, it is essential to implement management actions to conserve the remaining populations. Our results underline the importance for Environmental Impact Assessments (EIA) to include data on the genetic structure of species in the affected sites prior to their alteration or destruction. These genetic data are also remarkably important for determining where to relocate specific individuals to help avoid biodiversity loss.Fil: Oklander, Luciana Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Caputo, Mariela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Genética y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Fernández, Gabriela Paula. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Pergamino); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Jerusalinsky, Leandro. Centro Nacional de Pesquisa e Conservação de Primatas Brazileiros; BrasilFil: de Oliveira, Silviene F.. Universidade do Brasília; BrasilFil: Bonatto, Sandro Luis. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Corach, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Genética y Biología Molecular; Argentin

    Brazilian gamma detection device for sentinel lymph node biopsy

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    OBJECTIVE: To test the effectiveness of an intra-operative gamma detection Brazilian device (IPEN) on sentinel lymph node biopsy (SLNB) procedures. METHODS: Forty melanoma or breast cancer patients with indication for undergoing SLNB were studied. Lymphoscintigraphy was done 2 to 24 hours prior to surgery. Lymphatic mapping with vital dye and gamma detection were performed intraoperatively. For gamma detection Neoprobe ® 1500 was used followed by IPEN (equipment under test) in the first 20 patients and for the remaining half IPEN was used first to verify its ability to locate the sentinel node (SN). Measurements were taken from the radiopharmaceutical product injection site, from SN (in vivo and ex vivo) and from background. It was recorded if the SN was stained or not and if it was found easily by surgeon. RESULTS: There were 33 (82.5%) breast cancer and 7 (17.5%) melanoma patients. Ages varied from 21 to 68 year-old (median age of 46). Sex distribution was 35 (87.5%) women and 5 (12.5%) men. Sentinel node was found in all but one patient. There was no statistical difference between the reasons ex vivo/ background obtained with the measures of both equipments (p=0, 2583-ns). The SN was easily found by the surgeon with both devices. CONCLUSION: The SLNB was successfully performed using either equipment. It was possible to do SLNB with the Brazilian device developed by IPEN without prejudice for the patient.OBJETIVO: Testar a eficácia de equipamento de detecção gama intra-operatória (DGI) desenvolvido pelo IPEN (Brasil), em procedimentos de biópsia de linfonodo sentinela (BLS) no melanoma e no câncer de mama. MÉTODOS: Foram estudados 40 pacientes portadores de melanoma ou câncer de mama com indicação para realização de BLS.Todos pacientes foram submetidos à linfocintilografia e a BLS ocorreu entre 2 a 24 horas após a mesma. Concomitantemente à DGI, realizou-se o mapeamento linfático com corante vital. Foram feitas leituras com o equipamento convencional Neoprobe® 1500 e com o equipamento em teste (IPEN) dos valores de captação do sítio de injeção do radiofármaco, do LS in vivo e ex vivo e da captação de fundo. Foi registrado se o LS estava corado e se o cirurgião teve facilidade para encontrá-lo. Nos primeiros 20 pacientes utilizou-se o equipamento convencional e depois o de teste; nos outros 20, utilizou-se primeiro o equipamento em teste, com objetivo de verificar se o mesmo identificava primariamente o LS. RESULTADOS: Dos quarenta pacientes, 33 eram portadores de tumor de mama e sete de melanoma cutâneo; variação da idade: 21 a 68 anos (mediana= 46 anos); 35 mulheres e 5 homens. Em apenas um paciente o LS não foi encontrado, nem pela DGI nem pelo corante vital. Não houve diferença estatística entre as razões ex vivo/fundo obtidas com os dois equipamentos (p=0, 2583-ns). CONCLUSÃO: É possível realizar o procedimento de BLS com o equipamento brasileiro desenvolvido pelo IPEN, com facilidade e sem prejuízo para o paciente.Hospital Israelita Albert EinsteinIPENUniversidade Federal de São Paulo (UNIFESP)Faculdade de Medicina Anhembi-MorumbiUNIFESPSciEL

    Crescimento de plantulas da especie invasora Calotropis procera em solos de campos rupestres ferruginosos e floresta seca sazonal

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    The present study evaluated the growth, biomass allocation and nutrient content in seedlings of the invasive and exotic especies Calotropis procera (Aiton) W.T. Aiton (Apocynaceae), cultured in greenhouse, in soils from two different ecosystems: ironstone rupestrian fields (Canga) of Brumadinho, Minas Gerais; and seasonally dry forest (Caatinga), of Serra Talhada, Pernambuco. Seedlings from the Canga treatment were significantly higher in concern to stem length, leaf biomass and total biomass. In respect to nutrient content there were higher phosphorus, iron and zinc levels in the seedlings from the Canga treatment. The iron accumulation indicates the capacity of C. procera to tolerate high levels of iron, which is characteristic of Canga soils. In the Caatinga treatment there was a higher root/ shoot ratio and a higher potassium accumulation in the plant tissues. The obtained results suggest that C. procera displays a good adaptation to the edaphic conditions of the Canga treatment, which indicates an invasive potential towards the Canga ecosystem. Key words: Caatinga, Calotropis procera, Canga, early growth, invasion.O presente estudo avaliou o crescimento, a alocação de biomassa e os teores de nutrientes em plântulas da espécie exótica e invasora Calotropis procera (Aiton) W.T. Aiton (Apocynaceae), cultivadas em casa de vegetação, em solos provenientes de dois ecossistemas distintos: campo rupestre ferruginoso (Canga, Brumadinho, Minas Gerais) e floresta seca sazonal (Caatinga, Serra Talhada, Pernambuco). Plântulas do tratamento Canga foram significativamente maiores em relação ao comprimento do caule, biomassa de folhas e biomassa total. Em relação aos teores de nutrientes, houve maior teor de fósforo, ferro e zinco nos tecidos de plântulas do tratamento Canga. O acumulo de ferro indica a capacidade de C. procera em tolerar os altos teores de ferro característicos dos solos de Canga. No tratamento Caatinga, houve uma maior razão raiz-ramo e maior acúmulo de potássio em seus tecidos. Os resultados obtidos sugerem que C. procera demonstra boa adaptação às condições dos solos do tratamento Canga, indicando um potencial para invasão no ecossistema de Canga. Palavras-chave: Caatinga, Calotropis procera, Canga, crescimento inicial, invasão biológica
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