21 research outputs found

    Sedimentary sterols as indicators of environmental conditions in Southeastern Guanabara Bay, Brazil

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    As enseadas de Icaraí e Jurujuba, localizadas na porção sudoeste da Baía de Guanabara, são sujeitas a impactos ambientais decorrentes da ocupação humana nas suas bacias de drenagem. No presente trabalho foi determinada a composição elementar (C e N) e molecular (esteróides) da matéria orgânica em amostras de sedimentos superficiais (n = 24) e de um testemunho curto (c = 47 cm) nas enseadas. As concentrações de coprostanol, em comparação com outras áreas da Baía de Guanabara, indicaram elevado nível de contaminação por esgotos nas estações mais próximas ao ponto de lançamento de efluentes, na Enseada de Icaraí. A Enseada de Jurujuba, mais enclausurada e eutrófica, apresentou uma maior contribuição de matéria orgânica autóctone, conforme evidenciado pelos marcadores colesterol, dinosterol, e parcialmente, também , brassicasterol. A presença de estigmasterol e b-sitosterol indicaram leve contribuição de matéria orgânica oriunda de vegetação terrestre, conforme revelou a análise por componentes principais. No registro sedimentar, foram observados maiores teores de matéria orgânica e esteróis na camada superior, corroborando a acumulação recente de esgotos e de matéria orgânica fitoplanctônica, como conseqüência do processo de eutrofização do sistema. A presença de processos de degradação da matéria orgânica foi evidenciada pelas razões entre esteróis/estanóis, e o perfil do dinosterol indicou que na Enseada predomina o acúmulo de material fitoplanctônico anteriormente ao processo de eutrofização.The interconnected Icaraí and Jurujuba embayments, set within the lower south-eastern portion of Guanabara Bay, SE-Brazil, have been subject to the direct input of domestic effluents and other associated contaminants from human activities in their watersheds. This study addresses the composition of carbon, nitrogen and molecular steroid markers of surface sediments (n = 24) and a short core (L = 47 cm), in order to evaluate the impact by sewage, the contribution between allochthonous and autochthonous derived organic matter and eutrophication of the embayments. Coprostanol concentrations revealed, when compared to other regions in Guanabara Bay, high contamination by sewage close to the point of sewage discharge in Icaraí embayment. In contrast, the more enclosed and eutrophic Jurujuba embayment exhibited a larger contribution of autochthonous organic matter, as shown by the combination of cholesterol, dinosterol and, partially, also brassicasterol. The presence of stigmasterol and b-sitosterol also indicated a minor contribution of organic matter from terrestrial plants, as revealed by principal component analysis. The sedimentary record of the Jurujuba embayment exhibited highest concentrations of all sterol markers in the top layer, corroborating the recent increase in the accumulation of sewage, plankton derived organic carbon and also eutrophication. Trend in degradation of organic matter was evidenced by sterol/stanol ratios and the behavior of dinosterol indicated that the embayment has been dominated by the accumulation of phytoplankton derived organic matter since earlier times

    On the accumulation of organic matter on the southeastern Brazilian continental shelf: A case study based on a sediment core from the shelf off Rio de Janeiro

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    Sterol and fatty acid biomarkers and isotopic composition (delta 13C and delta 15N) of bulk organic matter (OM) were quantified in a sediment core to characterize the accumulation of autochthonous OM in an area on the continental shelf adjacent to Rio de Janeiro State. In the sediment surface (0-1 cm) the concentration of total sterols and fatty acids was at least one order of magnitude higher than that measured deeper down in the core and was dominated by labile and planktonic-derived biomarker compounds. These results suggest, as is confirmed by multivariate statistical analysis, the occurrence of an event of enhanced primary production in the water column and efficient export of particles to the bottom. Similar conditions have been observed at Cabo Frio, located 150 km to the north of our study site, during an upwelling event, suggesting that such events may exert a regional influence on primary production on the south-eastern Brazilian continental shelf. Beyond the signatures from this event, the presence of biomarker compounds from vascular plants suggests the additional influence of an outflow from Guanabara Bay at the study site. These results point to the need for further investigation of the relative influence of physical forcings and continental inputs on the biogeochemical processes on the section of the continental shelf considered in the present study

    ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

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    Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ

    Esterois como indicadores do acúmulo de esgotos domésticos em sedimentos de um sistema estuarino-lagunar tropical (Mundaú-Manguaba, AL)

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    The history of sewage contamination in the Mundaú-Manguaba estuarine lagoon system (NE Brazilian coastal zone) was evaluated through the concentration of sterols in sediment cores. The concentration of coprostanol increased towards the surface sediments, with the maximum of 5.65 µg g-1 at 0-2 cm sediment layer in Mundaú. Manguaba exhibited a lower level of contamination. The ratio cholestanol/cholesterol suggested degradation of coprostanol only before the burial of organic matter in the sediment. This feature, together with information of population growth in the watershed, allowed the estimation of a sedimentation rate of 0.90 cm year-1 to the Mundaú lagoon

    Fuzzy Logic: adding natural uncertainties into environmental assessment

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    This research study sought to evaluate aimed at evaluating the possible advantages of using Fuzzy Logic as opposed to Boolean Logic to assess environmental contamination and source appraisal for polycyclic aromatic hydrocarbons (PAH). Results obtained through traditional assessment tools for two different tropical coastal areas through using traditional clustering and principal components analysis were compared with those derived from the Fuzzy Logic, using the by Fuzzy C-means algorithm. The feedings achieved through Fuzzy Logic showed a greater qualitative detail than those derived from traditional tools. The abrupt and unnatural changes obtained from the usual classification methods were avoided by having membership values varying continuously in space, providing a more accurate picture of environmental contamination in complex and multiple sources environments. Furthermore, by not depending on statistic suppositions distribution of data like other methods, becomes more suitable for environmental data. Although Fuzzy Logic does not produce quantitative interpretations, its application generates adequate the data needed to avoid environmental management bias in the inference of contamination sources

    Spatial distribution of organic and inorganic contaminants in Ria de Aveiro Lagoon: A fundamental baseline dataset

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    This paper presents baseline data of sediments characterization from Ria de Aveiro lagoon (Portugal). Twenty-two intertidal surface sediments were collected and analysed for their pseudo-total content of 25 major and trace elements and for their total content of PAHs (Sum16) and PCBs (Sum13). The fine fraction percentage and total organic carbon content were also determined. Ria de Aveiro Lagoon has been the target of several studies during the last decades, and it has been pointed out as a hot spot in terms of contamination García-Seoane et al., 2016. Nevertheless, data about sediments contamination is mostly focused on Hg Lillebø et al.,2011, and in a specific area of the lagoon Grilo et al., 2013, and there is not a clear and global picture about the spatial distribution of other elements, and especially of organic contaminants. Thus, this baseline dataset is of utmost importance for researchers and planners and it can be used to monitor the effect of disturbances, such as: dredging activities; hydrodynamic changes (either due to human activities or extreme events); external inputs (new discharges from industries and wastewater plants, etc)

    Fístula de enxerto coronariano da artéria torácica interna esquerda para artéria pulmonar esquerda após cirurgia de revascularização miocárdica: causa rara de isquemia miocárdica Left internal thoracic artery to left pulmonary artery fistula after coronary artery bypass graft surgery: a rare cause of myocardial ischemia

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    Descrevemos o caso de um paciente que, seis anos após cirurgia de revascularização do miocárdio, desenvolveu dispnéia aos pequenos esforços. Foi documentada isquemia miocárdica por método de medicina nuclear e a cineangiocoronariografia mostrou todos os enxertos patentes com grande fístula da artéria torácica interna esquerda para artéria pulmonar esquerda. O paciente foi tratado com fechamento cirúrgico da fístula, tendo ótima evolução pós-operatória.<br>We report a patient who developed dyspnea on mild exertion six years after coronary artery bypass graft surgery (CABG). Myocardial ischemia was documented by radionuclide imaging, and coronary angiography showed patency of all grafts and a large fistula between the left internal thoracic artery (LITA) and the left pulmonary artery (LPA). The patient was submitted to surgical closure of the fistula and made an excellent recovery

    Uso da alga Lithothamnium calcareum como fonte alternativa de cálcio nas rações de frangos de corte Use of algae Lithothamnium calcareum as alternative source of calcium in diets for broiler chickens

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    Objetivou-se, com este trabalho, avaliar o uso da alga Lithothamnium calcareum (Pallas) Areschoug nas rações para frangos de corte de 1 a 21 e 21 a 42 dias de idade, em substituição à fonte de cálcio tradicional (calcário calcítico). Para isso, foram utilizados 300 pintos machos, da linhagem Cobb®, que receberam rações contendo o calcário calcítico e a alga Lithothamnium calcareum (colhida de inteira e na forma de areia biodentrítica) como fontes de cálcio. O delineamento experimental utilizado foi o inteiramente casualizado, com três tratamentos e cinco repetições de 20 aves cada. As variáveis analisadas foram: ganho de peso (g/ave), consumo de ração (g/ave) e conversão alimentar (g/g). No final do experimento foram avaliados os parâmetros ósseos: peso da tíbia (g), comprimento da tíbia (mm), diâmetro da tíbia (mm) e teor de cinzas na tíbia (%). Na fase inicial (1 a 21 dias) houve efeito (P<0,05) entre os tratamentos para o ganho de peso e conversão alimentar, sendo que o tratamento controle apresentou melhores resultados. Para a fase de crescimento (21 a 42 dias) e período total (1 a 42 dias) não houve efeito entre os tratamentos estudados. A utilização da alga Lithothamnium calcareum (independente da forma de colheita) em substituição à fonte de cálcio tradicional (calcário calcítico) pode ser recomendada para as rações de frangos de corte, sem prejudicar o desempenho zootécnico. Porém, deve-se levar em consideração a viabilidade econômica do uso dessa fonte alternativa nas rações.<br>The objective of this study was to evaluate the use of the algae Lithothamnium calcareum (Pallas) Areschoug in diets for broiler chickens from 1 to 21 and 21 to 42 days, to replace the traditional source of calcium (limestone). 300 male chicks from Cobb® strain, which received diets containing limestone and Lithothamnium calcareum algae (as a whole and as sand biodentritic) were used as sources of calcium. The experimental design was completely randomized, with three treatments and five replicates of 20 birds each. The variables analyzed were: weight gain (g / bird), feed intake (g / bird), feed per again (g / g). At the end of the experiment the bone parameters: weight of the tibia (g), tibia length (mm), diameter of the tibia (mm) and ash content in the tibia (%). Were evaluated in the initial phase (1 to 21 days) there was an effect (P <0.05) between treatments for weight gain and feed per again, and the control treatment showed better results. For the growing phase (21 to 42 days) and total period (1 to 42 days) there was no effect among the treatments studied. The use of the algae Lithothamnium calcareum (independently of the harvest) to replace the traditional source of calcium (limestone) can be recommended for diets of broilers without affecting the growth performance. However, one should take into consideration the economic feasibility of using this alternative source in the diets
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