405 research outputs found

    Fish brain development in a changing ocean

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    Tese de mestrado em Ecologia Marinha, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, em 2018Uma das prioridades da Ecologia Marinha relacionada com as alterações climáticas (aquecimento e acidificação dos oceanos) tem sido perceber como as espécies marinhas investem em tecidos cerebrais (ou regiões cerebrais) de modo a adaptarem-se às necessidades cognitivas relevantes para a aptidão ditada pelo ambiente em mudança. Neste contexto, esta dissertação teve como objetivo avaliar os efeitos combinados do aquecimento (Δ 4° C) e acidificação (Δ 700 μatm pCO2 e Δ 0,4 pH) oceânicos no desenvolvimento encefálico (relação massa encéfalo/ massa corporal e crescimento das macro-regiões do encéfalo) de várias espécies juvenis de peixes de diferentes regiões climáticas, a saber: três espécies adaptadas a um ambiente mais estável (tropical) (o peixe-palhaço Amphiprion ocellaris, o orquídea dottyback Pseudochromis fridmani e o neon-goby-azul Elacatinus oceanops), e outras três adaptadas a um ambiente menos estável (sazonal, temperado) (o sargo Diplodus sargus, o linguado Solea senegalensis e a corvina Argyrosomus regius). Os resultados mostram que as espécies temperadas usadas neste estudo são afetadas apenas pela acidificação do oceano, tanto ao nível da totalidade do encéfalo, como de cada macro-região específica, enquanto as espécies tropicais usadas são afetadas pela acidificação dos oceanos, aquecimento dos oceanos e também pela interação entre aquecimento dos oceanos e acidificação dos oceanos. De facto, tanto a totalidade do encéfalo como as macro-regiões encefálicas, exceto o telencéfalo, são afetados de maneira diferente pelas condições futuras de aquecimento dos oceanos e acidificação dos oceanos de acordo com cada espécie. A falta de respostas ao aquecimento dos oceanos pelas espécies temperadas é aqui atribuída à ampla distribuição latitudinal dessas espécies e, portanto, à adaptação a uma faixa de temperatura mais ampla que as espécies tropicais. Curiosamente, todas as interações significativas entre os dois fatores estudados são interações antagonísticas com um mecanismo de tolerância cruzada, o que significa que nessas interações, o peso do cérebro está mais próximo dos níveis das condições controlo do que sob cada um dos fatores separadamente. Possíveis implicações comportamentais e ecológicas desses resultados também são discutidas. Apesar do padrão dicotómico bem definido entre habitats temperados e tropicais, os resultados entre espécies de peixes e macro-regiões encefálicas específicas não exibem um padrão subjacente. Estes diferentes resultados destacam a ideia de respostas fenotípicas específicas de cada espécie em resposta às condições de alterações climáticas futuras.Unravelling how marine species invest in brain tissues (or brain regions) matching the fitness-relevant cognitive demands dictated by a changing environment is a priority in climate change-related (ocean warming and acidification) research. Within this context, this dissertation aimed to assess the combined effects of ocean warming (Δ 4 °C) and acidification (Δ 700 μatm pCO2 and Δ 0.4 pH) in the brain development (brain/body mass ratio and brain macro-region growth) of several juvenile fish species from different climate regions. Namely: three species adapted to a more stable (tropical) environment (clown anemonefish Amphiprion ocellaris, orchid dottyback Pseudochromis fridmani and neon goby Elacatinus oceanops), and other three adapted to a less stable (more seasonal; temperate) environment (seabream Diplodus sargus, flatfish Solea senegalensis and meagre Argyrosomus regius). The results show that the temperate species used in this study are only affected by ocean acidification in both total brain and specific brain regions, while the used tropical species are affected by ocean acidification, ocean warming and also by the interaction of ocean warming and ocean acidification. In fact, both total brain and every brain-region except for Telencephalon are affected by future conditions of ocean warming and ocean acidification differently according to each species. The lack of responses to ocean warming by the temperate species is here attributed to the widespread latitudinal distribution of those species, and thus the adaptation to a wider temperature range than tropical species. Curiously, all the significant interactions between the two studied stressors are antagonistic interactions with a cross-tolerance mechanism, meaning that under those interactions, the brain weight is closer to control levels than under each of the stressors separately. Possible behavioural and ecological implications of those results are also discussed. Despite the distinct dichotomic pattern between temperate and tropical habitats, the results among fish species and specific brain macro-regions do not exhibit a subjacent pattern. These different results highlight the idea of species-specific phenotypic responses to these climate change-related stressors

    Assessment of direct radiological risk and indirect associated toxic risks originated by Coal-Fired Power Plants

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    Over the past few decades there has been some discussion concerning the increase of the natural background radiation originated by coal-fired power plants, due to the uranium and thorium content present in combustion ashes. The radioactive decay products of uranium and thorium, such as radium, radon, polonium, bismuth and lead, are also released in addition to a significant amount of 40K. Since the measurement of radioactive elements released by the gaseous emissions of coal power plants is not compulsory, there is a gap of information concerning this situation. Consequently, the prediction of dispersion and mobility of these elements in the environment, after their release, is based on limited data and the radiological impact from the exposure to these radioactive elements is unknown. This paper describes the methodology that is being developed to assess the radiological impact due to the raise in the natural background radiation level originated by the release and dispersion of the emitted radionuclides. The current investigation is part of a research project that is undergoing in the vicinity of Sines coal-fired power plant (south of Portugal) until 2013. Data from preliminary stages are already available and possible of interpretation

    Radiation dose rates and exposure associated to Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) at locations of a Portuguese coal-fired power plant

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    Coal contains trace quantities of natural radionuclides such as Th-232, U-235, U-238, as well as their radioactive decay products and 40K. These radionuclides can be released as fly ash in atmospheric emissions from coal-fired power plants, dispersed into the environment and deposited on the surrounding top soils. Therefore, the natural radiation background level is enhanced and consequently increase the total dose for the nearby population. A radiation monitoring programme was used to assess the external dose contribution to the natural radiation background, potentially resulting from the dispersion of coal ash in past atmospheric emissions. Radiation measurements were carried out by gamma spectrometry in the vicinity of a Portuguese coal-fired power plant. The radiation monitoring was achieved both on and off site, being the boundary delimited by a 20 km circle centered in the stacks of the coal plant. The measured radionuclides concentrations for the uranium and thorium series ranged from 7.7 to 41.3 Bq/kg for Ra-226 and from 4.7 to 71.6 Bq/kg for Th-232, while K-40 concentrations ranged from 62.3 to 795.1 Bq/kg. The highest values were registered near the power plant and at distances between 6 and 20 km from the stacks, mainly in the prevailing wind direction. The absorbed dose rates were calculated for each sampling location: 13.97-84.00 ηGy/h, while measurements from previous studies carried out in 1993 registered values in the range of 16.6-77.6 ηGy/h. The highest values were registered at locations in the prevailing wind direction (NW-SE). This study has been primarily done to assess the radiation dose rates and exposure to the nearby population in the surroundings of a coal-fired power plant. The results suggest an enhancement or at least an influence in the background radiation due to the coal plant past activities

    Benzene biodegradability tests on a residual granitic soil

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    Benzene is a component of most fuels and an important industrial solvent. It is widely spread in soils, sediments and groundwater near diesel/gasoline service stations, refineries and in other industrial areas. For benzene, as other BTEXs, the most used in-situ remediation technology is Soil Vapour Extraction followed by bioremediation. In the present work, a bacterial consortium was developed for the systematic study of the benzene bioremediation of soils contaminated. The effectiveness of biodegradation was studied in a residual granitic soil. The developed microorganism consortium was collected from a protection area of crude storage tanks in a refinery. Our results showed that the developed consortium was efficient in degrading benzene (about 18 days for soil remediation contaminated with 140 mg of benzene per kg of residual granitic soil in lab-scale studies)

    Evaluation of xylene bioventing in a residual granitic soil remediation

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    In the present study a residual granitic soil contaminated with xylene was submitted to bioventing tests.The mostadequate range for the growth of the microbial consortia, developed from a soil sample collected in a refinery area, wasdetermined by extensive kinetic studies in flasks, using different contaminant concentrations. The selected xylenedegrader consortium of bacteria was used in custom-built soil bioventing columns, subject to a contamination levelpreviously established by kinetic studies, a constant air flow and room temperature. Control was done simultaneously byrespirometry, measuring O2, CO2 and moisture, by Gas Chromatography and by measuring biomass, counting colonyformingunits by spreading on Petri plates. Bioventing results a mathematical model contemplating different kineticsrates for the volatilized and for the biodegraded fractions of the contaminant

    PNAUM: abordagem integradora da Assistência Farmacêutica, Ciência, Tecnologia e Inovação

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    O artigo apresenta o processo de construção da Pesquisa Nacional sobre Acesso, Utilização e Promoção do Uso Racional de Medicamento a partir de uma concepção integradora da Assistência Farmacêutica, Ciência, Tecnologia e Inovação. Inicia-se contextualizando a saúde e o desenvolvimento no País e apresenta elementos da Política Nacional de Ciência Tecnologia e Inovação em Saúde no Brasil e da Política Nacional de Assistência Farmacêutica. Ao apresentar as diretrizes das Políticas Farmacêuticas, destaca-se a carência de dados de abrangência nacional. A presente pesquisa, encomendada pelo Ministério da Saúde, foi estruturada em dois componentes: inquérito domiciliar e avaliação dos serviços de assistência farmacêutica na atenção básica. As perspectivas dos resultados representam, além do incremento das políticas públicas farmacêuticas e de saúde pública, resultados de ações governamentais voltadas ao desenvolvimento do complexo econômico-industrial da saúde, visando a melhoria das condições de saúde da população brasileira.This paper describes the development process of the Pesquisa Nacional sobre Acesso, Utilização e Promoção do Uso Racional de Medicamentos (PNAUM – National Survey on Access, Use and Promotion of Rational Use of Medicines) based on an integrated approach to pharmaceutical services, science, technology and innovation. It starts by contextualizing health and development in Brazil and features elements of the National Policy for Science, Technology and Innovation in Health in Brazil and the National Policy for Pharmaceutical Services. On presenting pharmaceutical policy guidelines, it stresses the lack of nationwide data. This survey, commissioned by the Brazilian Ministry of Health, has two components: household survey and evaluation of pharmaceutical services in primary care. The findings point to perspectives that represent, besides the enhancement of public policy for pharmaceutical services and public health, results of government action aimed at developing the economic and industrial health care complex to improve the health conditions of the Brazilian population

    Libertação discriminatória de minérios : uma abordagem simulacional integrada

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    Tese de doutoramento. Ciências de Engenharia. Faculdade de Engenharia. Universidade do Porto. 199

    Assessment of Natural Radioactivity, Heavy Metals and Particulate Matter in Air and Soil around a Coal-Fired Power Plant—An Integrated Approach

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    A comprehensive study of the environmental radioactivity covered in a distance up to 20 km from a point source—two stacks of a coal-fired power plant. Airborne particulate matter was collected, and the element composition on the 30 cm soil profile was determined. The range of activity concentrations of 226Ra, 232Th and 40K from the studied areas varies from 8 Bq/kg to 41 Bq/kg, 5 to 72 Bq/kg and 62 to 795 Bq/kg, respectively. The activities values are increased by 44% for 226Ra, 37% for 40K, and 75% for 232Th in the prevailing wind direction. For some elements, the respective concentration in the soil is above the maximum permissible level for all types of soil use, particularly for the arsenic concentration. The deposition flux ranged from 0.36 to 5.70 (g m−2 per month) in the first sampling campaign and from 0.02 to 3.10 (g m−2 per month) for the second sampling campaign. Maps on the spatial distribution of gamma dose rates, radionuclides activity concentrations, deposition flux and trace metals in topsoil were developed for the study region. These maps are in accordance with higher values in specific locations in the vicinity of the coal-fired power plant, showing the influence of point sources, and for locations within 6 and 20 km from the stacks, particularly in the prevailing wind direction

    Assessment of heavy metals in the surroundings of coal-fired power plant

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    This paper aims to survey metal concentrations in soils in the vicinity of a coal-firedpower plant located in southwest of Portugal. Two annual sampling campaigns were carried out to measure a hypothetical soil contamination around the coal plant. The sampling area was divided into two subareas, both centered in the emission source, delimited by two concentric circles with radius of 6 km and 20 km. About 40 samplings points were defined in the influence area. Metals measurements were performed with a portable analytical X-ray dispersive energy fluorescence spectrometer identifying about 20 different elements in each sampling point. The most relevant elements measured included As, Cu, Fe, Hg, Pb, Ti and Zn in both sampling areas. Considering the results obtained in the first sampling campaign, arsenic is predominantly higher within the 6-20 km sampling area. The second sampling campaign showed that both sampling areas presented relatively similar metal concentrations except for Fe, Mn, Sr and Zn which concentration is higher within the 6-20 km sampling area. Also, As, Fe, Mn and Ti concentrations decreased significantly from the first to the second sampling campaign and their concentration were predominately higher in the NE-E and E-SE directions
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