866 resultados para Solos arenosos - Lisboa (Portugal)


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Tem havido uma preocupação crescente com a qualidade do ar interior (QAI) nas escolas em muitos países. Muitos estudos epidemiológicos têm encontrado diferenças regionais entre ambientes interiores. Apesar da elevada incidência de asma e rinite na população infantil, praticamente nada se sabia sobre a QAI em escolas portuguesas. A percepção dos problemas de QAI é crucial para avaliar os riscos para a saúde e rendimento dos estudantes, e para sugerir meios de reduzir a exposição a poluentes indesejáveis. Neste estudo procurou-se obter as concentrações de poluentes de interesse em estabelecimentos de ensino do 1º ciclo de Lisboa e Aveiro, estimar o estado atual de casos de asma e rinite em escolas primárias da capital, avaliar a influência de diferentes materiais das salas de aula/construção e hábitos escolares na QAI, identificar potenciais fontes de poluentes nos interiores e exteriores das salas de aula e propor medidas mitigadoras. Catorze escolas de Lisboa foram visitadas para obter a caracterização física das construções em termos de estrutura, ventilação, materiais de acabamento, produtos de limpeza, densidade de ocupação e potenciais fontes interiores de poluição. Os estudantes foram questionados sobre os seus hábitos e sintomas respiratórios através de inquéritos do modelo ISAAC (International Study of Asthma and Allergies in Childhood). Durante a primavera, outono e inverno (2008-2010), nas salas de aula e pátios, foram monitorizados, por amostragem passiva, compostos orgânicos voláteis (COVs), carbonilos e dióxido de azoto (NO2). Foram também medidos parâmetros de conforto e níveis de microrganismos. Duas escolas localizadas, uma no centro da cidade e outra na região suburbana, em Aveiro foram estudadas em 2010. Parâmetros de conforto, microrganismos, COVs, NO2, material particulado (PM10) foram medidos no interior e no exterior de ambas escolas. Os iões solúveis, carbono orgânico e elementar (OC e EC), e compostos orgânicos presentes no material particulado foram subsequentemente analisados em laboratório. Uma medida mitigadora - fitoremediação - foi avaliada na escola do centro da cidade de Aveiro em 2011. Os resultados do estudo mostraram que a QAI é pior do que a do ar exterior. Em geral, os níveis de CO2 e dos bioaerosóis excederam os níveis máximos aceitáveis para o conforto dos ocupantes estipulado pelas regulamentações portuguesas. Quase todos os COVs e carbonilos identificados mostraram razões interior/exterior (I/E) maiores que uma unidade, o que demonstra a importante contribuição de fontes interiores em todas as escolas. As razões I/E das concentrações de NO2 nunca excederam a unidade. Os níveis interiores diários de PM10 foram sempre maiores que os exteriores, exceto nos fins de semana. Após a colocação de plantas numa das salas de aula, observou-se uma redução estatisticamente significativa nos níveis de CO2, COVs, carbonilos, PM10, OC, e dos iões nitrato, sulfato, amónia, cálcio e carbonato. A possível redução dos níveis de poluentes no interior após a colocação de plantas pode representar uma solução de baixo custo para reduzir a exposição a muitos compostos, melhorar o rendimento e aumentar o bem estar dos alunos e professores em sala de aula.

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This investigation focused on the development, test and validation of methodologies for mercury fractionation and speciation in soil and sediment. After an exhaustive review of the literature, several methods were chosen and tested in well characterised soil and sediment samples. Sequential extraction procedures that divide mercury fractions according to their mobility and potential availability in the environment were investigated. The efficiency of different solvents for fractionation of mercury was evaluated, as well as the adequacy of different analytical instruments for quantification of mercury in the extracts. Kinetic experiments to establish the equilibrium time for mercury release from soil or sediment were also performed. It was found that in the studied areas, only a very small percentage of mercury is present as mobile species and that mobility is associated to higher aluminium and manganese contents, and that high contents of organic matter and sulfur result in mercury tightly bound to the matrix. Sandy soils tend to release mercury faster that clayey soils, and therefore, texture of soil or sediment has a strong influence on the mobility of mercury. It was also understood that analytical techniques for quantification of mercury need to be further developed, with lower quantification limits, particularly for mercury quantification of less concentrated fractions: water-soluble e exchangeable. Although the results provided a better understanding of the distribution of mercury in the sample, the complexity of the procedure limits its applicability and robustness. A proficiency-testing scheme targeting total mercury determination in soil, sediment, fish and human hair was organised in order to evaluate the consistency of results obtained by different laboratories, applying their routine methods to the same test samples. Additionally, single extractions by 1 mol L-1 ammonium acetate solution, 0.1 mol L-1 HCl and 0.1 mol L-1 CaCl2, as well as extraction of the organometallic fraction were proposed for soil; the last was also suggested for sediment and fish. This study was important to update the knowledge on analytical techniques that are being used for mercury quantification, the associated problems and sources of error, and to improve and standardize mercury extraction techniques, as well as to implement effective strategies for quality control in mercury determination. A different, “non chemical-like” method for mercury species identification was developed, optimised and validated, based on the thermo-desorption of the different mercury species. Compared to conventional extraction procedures, this method has advantages: it requires little to no sample treatment; a complete identification of species present is obtained in less than two hours; mercury losses are almost neglectable; can be considered “clean”, as no residues are produced; the worldwide comparison of results obtained is easier and reliable, an important step towards the validation of the method. Therefore, the main deliverables of this PhD thesis are an improved knowledge on analytical procedures for identification and quantification of mercury species in soils and sediments, as well as a better understanding of the factors controlling the behaviour of mercury in these matrices.

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Urban soil quality may be severely affected by hydrophobic organic contaminants (HOCs), impairing environmental quality and human health. A comprehensive study was conducted in two contrasting Portuguese urban areas (Lisbon and Viseu) in order to assess the levels and potential risks of these contaminants, to identify sources and study their behaviour in soils. The concentrations of HOCs were related to the size of the city, with much higher contamination levels observed in Lisbon urban area. Source apportionment was performed by studying the HOCs profiles, their relationship with potentially toxic elements and general characteristics of soil using multivariate statistical methods. Lisbon seems to be affected by nearby sources (traffic, industry and incineration processes) whereas in Viseu the atmospheric transport may be playing an important role. In a first tier of risk assessment (RA) it was possible to identify polycyclic aromatic hydrocarbons (PAHs) in Lisbon soils as a potential hazard. The levels of PAHs in street dusts were further studied and allowed to clarify that traffic, tire and pavement debris can be an important source of PAHs to urban soils. Street dusts were also identified as being a potential concern regarding human and environmental health, especially if reaching the nearby aquatic bodies. Geostatistical tools were also used and their usefulness in a RA analysis and urban planning was discussed. In order to obtain a more realistic assessment of risks of HOCs to environment and human health it is important to evaluate their available fraction, which is also the most accessible for organisms. Therefore, a review of the processes involved on the availability of PAHs was performed and the outputs produced by the different chemical methods were evaluated. The suitability of chemical methods to predict bioavailability of PAHs in dissimilar naturally contaminated soils has not been demonstrated, being especially difficult for high molecular weight compounds. No clear relationship between chemical and biological availability was found in this work. Yet, in spite of the very high total concentrations found in some Lisbon soils, both the water soluble fraction and the body residues resulting from bioaccumulation assays were generally very low, which may be due to aging phenomena. It was observed that the percentage of soluble fraction of PAHs in soils was found to be different among compounds and mostly regulated by soil properties. Regarding bioaccumulation assays, although no significant relationship was found between soil properties and bioavailability, it was verified that biota-to-soil bioaccumulation factors were sample dependent rather than compound dependent. In conclusion, once the compounds of potential concern are targeted, then performing a chemical screening as a first tier can be a simple and effective approach to start a RA. However, reliable data is still required to improve the existing models for risk characterization.

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Os efetivos autóctones de pequenos ruminantes têm vindo a diminuir,em parte devido ao seu baixo potencial produtivo. A necessidade de encontrar formas mais expeditas de aumentar o potencial produtivo das nossas raças, e assim promover a sua manutenção bem como a sustentabilidade dos sistemas extensivos onde são explorados, levou à procura de marcadores moleculares, nomeadamente no gene da hormona de crescimento (GH), associados com a produção e qualidade do leite em pequenos ruminantes. Nas raças ovinas Churra da Terra Quente, Merino da Beira Baixa, Saloia e Serra da Estrela e caprinas Algarvia e Serrana verificou -se que o gene da GH é muito polimórfico, tendo sido encontrados polimorfismos específicos em algumas das raças. Os resultados sugerem que os polimorfismos do gene da GH, entre outros (e.g., nas caseínas), poderão vir a ser utilizados na seleção assistida por marcadores genéticos, de modo a melhorar da produção de leite sem afetar a sua qualidade. Contudo, a resposta à seleção será sempre condicionada pela prática de um correto maneio alimentar dos animais.

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Tese de mestrado, Arte, Património e Teoria do Restauro, Universidade de Lisboa, Faculdade de Letras, 2011

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The phytochemical study of Euphorbia piscatoria yielded jolkinol D (1) in a large amount, whose derivatization gave rise to 12 ester derivatives (2–13) and hydrolysis to compound 14. The in vitro modulation of P-gp of compounds 1–14 was evaluated through a combination of transport and chemosensitivity assays, using the L5178 mouse T lymphoma cell line transfected with the human MDR1 gene. Apart from jolkinol D, all derivatives (2–14) showed potential as MDR reversal agents. In this small library of novel bioactive macrocyclic lathyrane diterpene derivatives, designed to evaluate structure–activity relationships essential in overcoming multidrug resistance (MDR), some correlations between MDR reversal and molecular weight, accessible solvent areas, and octanol/water partition coefficient were identified that can contribute to the development of new selective P-gp reversal agents.

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The relevance of the relationship between evaluation and learning is widely acknowledged; as well as the importance of this learning process to support policy decision making and to judge the value of “what was done”, “how” and “with what results”. Although the activity of evaluation is not something new, but a field of knowledge with its own theories and practices, it is important to notice that there is great variability in the tradition and cultures of evaluation between countries. This paper presents and compares different conceptual and methodological frameworks created for the assessment of the European initiative Urban II, including the one that was used by the author in the context of an academic evaluation in the city of Porto. The comparative analysis of the results leads us to the recommendation for more democratic processes of evaluation and intervention, in order to improve their quality and accountability and promote the important goal of learning with this type of experimental initiatives.

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Artigo baseado na comunicação proferida na Conferência “O Lugar da Cultura no Jornalismo Contemporâneo”, realizado na Faculdade de Ciências Sociais e Humanas, (FCSH), Lisboa, Portugal, 22 de maio de 2014

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Artigo baseado na comunicação proferida no 8º Congresso SOPCOM: Comunicação Global, Cultura e Tecnologia, realizado na Escola Superior de Comunicação Social (ESCS-IPL), Lisboa, Portugal, 17-19 de outubro de 2013

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Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes

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Web 2.0 software in general and wikis in particular have been receiving growing attention as they constitute new and powerful tools, capable of supporting information sharing, creation of knowledge and a wide range of collaborative processes and learning activities. This paper introduces briefly some of the new opportunities made possible by Web 2.0 or the social Internet, focusing on those offered by the use of wikis as learning spaces. A wiki allows documents to be created, edited and shared on a group basis; it has a very easy and efficient markup language, using a simple Web browser. One of the most important characteristics of wiki technology is the ease with which pages are created and edited. The facility for wiki content to be edited by its users means that its pages and structure form a dynamic entity, in permanent evolution, where users can insert new ideas, supplement previously existing information and correct errors and typos in a document at any time, up to the agreed final version. This paper explores wikis as a collaborative learning and knowledge-building space and its potential for supporting Virtual Communities of Practice (VCoPs). In the academic years (2007/8 and 2008/9), students of the Business Intelligence module at the Master's programme of studies on Knowledge Management and Business Intelligence at Instituto Superior de Estatistica e Gestao de Informacao of the Universidade Nova de Lisboa, Portugal, have been actively involved in the creation of BIWiki - a wiki for Business Intelligence in the Portuguese language. Based on usage patterns and feedback from students participating in this experience, some conclusions are drawn regarding the potential of this technology to support the emergence of VCoPs; some provisional suggestions will be made regarding the use of wikis to support information sharing, knowledge creation and transfer and collaborative learning in Higher Education.

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The temporal lobe epilepsy (TLE) is the most common type of refractory epilepsy in adults. There is a wide consensus regarding the commitment of memory in temporal lobe epilepsy with hippocampal sclerosis. However, the consensus is not as widespread with respect to the other functions such as attention, executive functions, language and intellectual performance. For this study we analyzed retrospectively a group of 76 patients with refractory epilepsy, 48 patients with temporal lobe epilepsy (23 with right lateralization and 25 with left lateralization) and 28 patients with extratemporal epilepsy. We applied a battery of neuropsychological tests used in the Epilepsy Surgery Program at Hospital de Egas Moniz, Lisbon, Portugal. Our results show that the battery of neuropsychological tests is internally consistent in the evaluation of patients with TLE. We have also found that patients with TLE have standard generalized deficits witch could be indicative of areas of engagement besides the hippocampus. One interesting finding was the fact that interference verbal memory (long term memory) remains adequate, suggesting that this function is not compromised in TLE. In addition to the general pattern of cognitive deficits, we can see the impact of the disease at the socio-demographic level, and we can also establish a relationship with neurobiological findings previously described in the literature

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JosÒo Pedro da Ponte es profesor del Departamento de Educación y Centro de Investigación en Educación, Facultad de Ciencias de la Universidad de Lisboa, Portugal. Resumen basado en la revista

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Análisis del empleo de software educativo en los centros escolares portugueses. Analizar la utilización de software en la enseñanza de Ciencias Naturales y Biología de los ciclos segundo y tercero del sistema educativo portugués, así como los posibles problemas y dificultades que surgen con su uso. Conocer el nivel de formación específica que poseen los profesores de las instituciones educativas de la zona de Lisboa, Portugal, en el empleo de software educativo, así como sus opiniones sobre la integración de software educativo en las disciplinas de Ciencias Naturales y Biología. Se trabajó con 9 escuelas, ubicadas en las subregiones de Lisboa, cinco de las cuales participaron en el Proyecto Pedactice con la Universidad de Lisboa de 1998-2000, y 4 colegios privados escogidos al azar. Se involucraron las escuelas del proyecto Practice por considerarse que estaban un poco más sensibilizadas con trabajos relacionados en el empleo de tecnologías en el ámbito de la enseñanza. El cuestionario fue aplicado a los profesores del área de Ciencias Naturales y Biología en los niveles educativos de segundo y tercer ciclo, previa concertación con los directores y los Consejos Directivos de los centros. Las variables analizadas son: A.- Edad del profesorado participante. B.- Situación administrativa del profesorado. C.- Conocimiento sobre la utilización de los medios. D.- Forma en la que adquirieron la información. E.- Funciones en la utilización del software. F.- Medios utilizados en la motivación de la enseñanza de las Ciencias Naturales. G.- Causas de la no utilización de software educativo.- H.- Conocimiento de software educativo en Ciencias Naturales.- I.- Papel del profesor en el uso de software educativo. Cuestionario de 21 ítems para recoger información sobre el nivel de utilización del software educativo por parte de los profesores, las dificultades y problemas en la utilización de este medio y la formación específica que poseen o demandan sobre la temática. Análisis estadístico descriptivo: obtención de frecuencias, porcentajes, medias, varianza y desviación típica. Análisis de estadísticos inferenciales: aplicación de la prueba no paramétrica de Chi cuadrado para comprobar si existían o no diferencias en función de la edad de los profesores o la titularidad del centro. Los datos obtenidos en la investigación permiten concluir que el porcentaje de profesores en el área de Ciencias Naturales y Biología que integra el software educativo en el desarrollo de sus actividades docentes en Primaria es aún bajo, hecho que puede justificarse porque el profesorado no ha recibido información sobre las tecnologías de la información y la comunicación y los medios didácticos en sus estudios, lo que se traduce en su desinterés por la utilización de medios informáticos y especialmente el software educativo que hace que el esfuerzo institucional realizado por el Ministerio de Educación de Portugal a través de los distintos programas no obtenga los resultados esperados. Se considera prioritario incentivar al profesorado en las instituciones de formación inicial y continua que se desarrollen actividades formativas dirigidas a fomentar las posibilidades del software educativo y el conocimiento de la integración del ordenador en la enseñanza. Las condiciones de las escuelas respecto al uso de medios informáticos no son las adecuadas, siendo necesario mejorar las infraestructuras y las dotaciones de ordenadores en los centros. El profesorado coincide en que las dos funciones principales del software educativo son las de motivar y explorar conceptos, que el software educativo en Ciencias Naturales debe dar énfasis a la comprensión de significados, de modelos, de representaciones, permitiendo potenciar un espíritu crítico ante las los diferentes mensajes y lenguajes utilizados. Los medios más utilizados en los procesos de motivación y enseñanza son los medios impresos seguidos del material audiovisual; la mayoría del profesorado indica no conocer los títulos más relevantes de software educativo para Ciencias Naturales, manifiestan que no utilizan los programas por no ajustarse a los objetivos y contenidos de la disciplina. Los aspectos considerados más relevantes por los participantes son: contribuir a la adquisición de capacidades de autoaprendizaje (64,6 por ciento), mejorar el rendimiento académico y ayudar a disminuir el fracaso escolar (66,2 por ciento) y estimular en el alumnado la iniciativa y originalidad y la imaginación; destacan la posibilidad de facilitar los procesos de adaptaciones curriculares. El uso de software educativo como medio integrado en el currículo requiere una metodología activa en la enseñanza de Ciencias Naturales y Biología, permitiendo a los alumnos la construcción del conocimiento de una manera más significativa, acorde con sus intereses y necesidades. El profesor ha de ser orientador de la actividad, planificador de las tareas y animador de los aprendizajes.