241 research outputs found

    Responses of Functional and Taxonomic Phytoplankton Diversity to Environmental Gradients in Subtropical and Tropical Reservoirs

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    Understanding the influence of environmental conditions on biodiversity is a major task in ecology. We investigated how phytoplankton taxonomic (TD) and functional (FD) diversities vary with environmental factors in eight subtropical and tropical reservoirs. We hypothesized that i) environmental variables affect phytoplankton TD and FD; ii) FD provides better relationships to environmental changes than TD, and; iii) indices based on biomass are better related to the environment than those based on identities. The relationships between phytoplankton diversities and environmental drivers were assessed through generalized linear models. Our hypotheses were partly confirmed. TD and FD were, in fact, dependent on the environment, with higher values occurring in warmer, clearer, and more enriched systems, under lower zooplankton grazing pressure; but FD based on identities was not predicted better from environmental conditions than TD based on identities. As expected, indices based on biomass are better related to the environment than their counterpart based on identities

    Downstream transport processes modulate the effects of environmental heterogeneity on riverine phytoplankton

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    Environmental heterogeneity (EH) in space and time promotes niche-partition, which leads to high variation in biological communities, such as in algae. In streams, EH is highly related to the intensity of the water flow and may lead to community variation mainly during the low flow conditions. Despite the wide knowledge on the responses of phytoplankton communities to EH in lentic and semi-lentic systems, studies of riverine phytoplankton community variation are still scarce. Here, we first investigated the relationship between phytoplankton community variation and EH in different courses of the river and between seasons. We expected that under low or intermediate flow conditions, there is a positive correlation between community variation and EH. Alternatively, we did not expect any relationship between EH and community variation under high flow condition because stronger downstream transport would mask environmental filtering. We sampled nine sites monthly (May 2012 to April 2013) in a tropical river of Brazilian Southeast. We calculated EH from abiotic data whereas for community variation, here community distinctiveness (CD), we used Sorensen (CDSor) and Bray-Curtis (CDBray) dissimilarities. Differences in EH, CDSor and CDBray were tested at between-season and among-course levels. We found lower distinctiveness during the dry season when EH was the highest. Contrastingly, phytoplankton CD was the highest even when EH was low during the wet season. We found that this pattern raised from the increasing in individuals dispersal during the wet season, promoting mass effects. Finally, our results thus reject the first hypothesis and show a negative relationship between EH and distinctiveness. However, results support our alternative hypothesis and show that during the wet season, distinctiveness is not driven by EH. These results provide new insights into how EH drives community variation, being useful for both basic research about riverine algal communities and biomonitoring programs using phytoplankton communities as bioindicators. (C). 2019 Elsevier B.V. All rights reserved.Peer reviewe

    Auto anti oxLDL, IgM and IgG: comparison between sedentary and athletes

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    Introduction: The practice of regular physical activity contributes to reduce the prevalence of coronary hearth disease (CHD) and aerobic exercises are associated with beneficial changes in the profile of circulating lipids and lipoproteins. However in the past years the oxidative hypothesis assumed great importance in the pathogenesis of CHD. During exhaustive exercises there is a greater possibility of oxidation of LDL, forming oxidized LDL (oxLDL) that has a key role in atherogenesis. However the incidence of coronary events in athletes is lower than in sedentary persons. It is described in the literature that we can found in serum auto autoantibodies anti-oxLDL, of the isotypes IgG and IgM. The former involved with atherogenesis and the latter with an atheroprotective function. The aim of this study was to verify if there are differences in the prevalence of the different autoantibodies between athletes and sedentary persons. Methods: Twenty male recreational runners and twenty male sedentary individuals living in the city of São Paulo were recruited for the study. Both the study protocol and consent form had been approved by the UNIFESP-EPM Ethics Committee. None of the participants were using lipid-lowering medications, no smokers, addicted to alcohol consumption, obese or had systemic arterial hypertension, neither liver, renal, metabolic, inflammatory or neoplastic diseases. Blood sample were collected at rest. Blood draws for all the individuals were performed after 12 hours of fasting. IgM and IgG anti ox LDL specific reactivity in serum, were measured by ELISA using previously stored serum. Student’s t-test was used to analyze differences in age and body mass index (BMI). The Mann-Whitney test was used to determine if the differences between the results for sedentary individuals and those for runners at rest were significant. Results: We found that at rest the group of athletes studied showed a statistically higher concentration of IgM autoantibodies against ox-LDL than controls (figure 1 a). At the same time, IgG autoantibodies anti ox-LDL presented the same concentration in controls and athletes (Figure 1 b). Conclusion: This finding is of extreme importance when we consider the prevalence of CHD in those different populations and the opposite actions of these two isotypes of antibodies

    Evaluation of mutagenicity and antimutagenicity of different fractions of Pterogyne nitens (Leguminosae), using Tradescantia pallida micronuclei assay

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    Pterogyne nitens (Fabaceae-Caesalpinioideae) é uma árvore nativa da América do Sul, onde é empregada na medicina popular para o tratamento da ascaridíase. Recentemente, descrevemos o efeito mutagênico do extrato etanólico das folhas de P. nitens. Dessa forma, o presente estudo teve por objetivo aprofundar a avaliação do potencial mutagênico das frações isoladas das folhas de Pterogyne nitens, acetato de etila (AcOEt), n-butanólica (BuOH) e hidroalcóolica (HA). Quando o efeito mutagênico foi observado somente nas maiores concentrações testadas, o potencial antimutagênico também foi avaliado. Os ensaios mutagênicos e antimutagênicos foram realizados utilizando ensaio de micronúcleo em Trandescantia pallida. Na avaliação de mutagenicidade, observou-se o efeito nas frações AcOEt (0,460 mg/mL), BuOH (0,142, 0,285, 0,570 e 1,14 mg/mL) e HA (0,050, 0,100, 0,200 e 0,400 mg/mL). Considerando que o efeito mutagênico da fração AcOEt foi observado somente na concentração mais elevada (0,460 mg/mL), o potencial antimutagênico da mesma foi avaliado. As concentrações de 0,115 e 0,230 mg/mL da fração AcOEt demonstraram atividade antimutagênica. A partir dos resultados do presente estudo, conclui-se que determinadas frações de P. nitens apresentam mutagenicidade (BuOH e HA), enquanto a fração AcOEt apresentou efeito antimutagênico nas maiores concentrações. Esses resultados tornam o estudo da P. nitens bastante promissor, considerando que esta planta possui distribuição geográfica ampla e tem sido pouco estudada.Pterogyne nitens (Fabaceae-Caesalpinioideae) is a tree native to South American, where it is used in folk treatment of ascaridiasis. Recently, we have been describing the mutagenic effect of the ethanol extract of leaves of P. nitens. Thus, the present study aimed at evaluating the mutagenic potential of the ethyl acetate (EtOAc), n- butanol (BuOH) and hydroalcoholic (HA) fractions. When the mutagenic effect was observed only in the highest tested concentrations, the antimutagenic activity was also evaluated. Both mutagenic and antimutagenic assays were performed using T. pallida micronuclei assay. Mutagenicity was observed between different concentrations of the P nitens fractions, EtOAc (0.460 mg/mL), BuOH (0.142, 0.285, 0.570 and 1.14 mg/mL) and HA (0.050, 0.100, 0.200 and 0.400 mg/mL). Whereas the mutagenic effect of the EtOAc fraction was observed in the highest concentration (0.460 mg/mL), its antimutagenic potential was evaluated. The 0.115 and 0.230 mg/mL concentrations of the EtOAc fraction demonstrated antimutagenic activity. Based on the results of the present study we can conclude that some P. nitens fractions (BuOH and HA) demonstrated mutagenic effects whereas the EtOAc fraction shown low mutagenicity and amtimutagenicity in the two higher concentrations. Those results stimulate the studies with P. nitens, which possess spread geographic distribution and it is still low studied

    Cymbopogon winterianus essential oil attenuates bleomycin-induced pulmonary fibrosis in a murine model

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    The essential oil of Cymbopogon winterianus (EOCW) is a natural product with antioxidant, anti-inflammatory, and antifibrotic properties. We studied the effect of EOCW in the progression of histological changes of pulmonary fibrosis (PF) in a rodent model. The oil was obtained by hydrodistillation and characterized using gas chromatographymass spectrometry. Intratracheal instillation of bleomycin was performed in 30 rats to induce PF, while Sham animals were subjected to instillation of saline solution. The treatment was performed using daily oral administration of distilled water, EOCW at 50, 100, and 200 mg/kg, and deflazacort (DFC). After 28 days, hemogram and bronchoalveolar lavage fluid (BALF), tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were assayed. Histological grading of PF, immunohistochemical expression of -smooth muscle actin (-SMA), and transforming growth factor- (TGF-) were also analyzed. The EOCW major compounds were found to be citronellal, geraniol, and citronellol. EOCW significantly reduced inflammation in BALF, reduced MDA levels, and increased SOD activity. EOCW attenuated histological grading of PF and reduced immunohistochemical expression of -SMA and TGF- in a dose-dependent way, likely due to the reduction of oxidative stress, inflammation, and TGF--induced myofibroblast differentiation.This research was financed by the Coordenação Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de Sergipe (FAPITEC), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). EBS wishes to acknowledge the sponsorship of the project UIDB/04469/2020 (strategic fund) from the Portuguese Science and Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and was co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

    Nasal bot : an emerging parasitic disease in small ruminants in the Brazilian Northeast

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    No período de janeiro de 2011 a dezembro de 2014 foram diagnosticados 9 surtos (A, B, C, D, E, F, G, H e I) de Oestrus ovis em pequenos ruminantes no estado da Bahia. No surto A obteve-se 0,5% (1/200); B 2,2% (2/90); C 0,8% (1/120); D 2% (2/100); E 1% (1/100); F 3% (1/33); G 0,6% (1/150); H 2,5% (5/200); I com 11,4% (8/70) em ovinos e 5% (2/40) em caprinos. Os sinais clínicos associados ao parasitismo pelas larvas nos surtos foram respiração ruidosa, espirro seguido de secreção nasal catarral, inquietação, movimentação excessiva da cabeça e andar em círculo. Macroscopicamente havia nos seios e conchas nasais hiperemia, edema da mucosa e presença de larvas. Todas as larvas coletadas dos cornetos e conchas nasais variavam desde o primeiro ao terceiro estágio de desenvolvimento. Algumas larvas L3 coletadas nas necropsias foram incubadas e o imago obtido das pupas mediram aproximadamente 10mm de cor acinzentada e abdômen escurecido. Realizada análise descritiva das condições climáticas, ano e positividade de casos de oestrose, demonstrou que a ocorrência tem tendência de crescimento com os anos (p˂0,001) e que houve casos com menor média de temperatura mínima (p˂0,001), possibilitando o desenvolvimento da mosca de O. ovis, demonstrando que houve a introdução da mosca enTtre o rebanho de ovinos e caprinos do estado da Bahia, e que as condições climáticas são ideais para perpetuação da espécie.From January 2011 to December 2014 were diagnosed 9 outbreaks of Oestrus ovis infection in small ruminants (Outbreaks A-I) in the State of Bahia. The incidence of oestrosis in sheep in outbreak A was 0.5% (1/200), in B 2.2% (2/90), in C 0.8% (1/120), in D 2% (2/100), in E 1% (1/100), in F 3% (1/33), in G 0.6% (1/150), in H 2.5% (5/200), and in I 11.42% (8/70), and 5% (2/40) in goats. Clinical signs associated with parasitism were wheezing, sneezing followed by catarrhal nasal secretion, some restlessness, excessive head movement and walking in circles. The breasts and turbinates were hyperemic, with mucosal edema and presence of O. ovis larvae. All larvae collected from the turbinates ranged from the first to the third stage of development. Some L3 larvae collected at necropsy were incubated and the gray colored Imago with dark abdomen obtained from the pupae measured about 10mm. A descriptive analysis of the climatic conditions was carried out; in the year of investigation the incidence of O. ovis infection has grown (p<0.001), and the lowest mean minimum temperature (p<0.001) caused the development the O. ovis fly, so that there was an introduction of an increased number of these flies into the sheep and goat flocks in state of Bahia with the ideal climatic conditions for their perpetuation
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