866 resultados para Zonas de sutura
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Refletindo a importância actual da qualidade do ambiente urbano na sustentabilidade global do planeta, há uma tendência crescente em reconhecer a importância dos espaços verdes na zonas urbanes e como uma das componentes essenciais da morfologia urbana.
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Climate change scenarios comprise significant modifications of the marine realm, notably ocean acidification and temperature increase, both direct consequences of the rising atmospheric CO2 concentration. These changes are likely to impact marine organisms and ecosystems, namely the valuable seagrass-dominated coastal habitats. The main objective of this thesis was to evaluate the photosynthetic and antioxidant responses of seagrasses to climate change, considering CO2, temperature and light as key drivers of these processes. The methodologies used to determine global antioxidant capacity and antioxidant enzymatic activity in seagrasses were optimized for the species Cymodocea nodosa and Posidonia oceanica, revealing identical defence mechanisms to those found in terrestrial plants. The detailed analysis and identification of photosynthetic pigments in Halophila ovalis, H.stipulacea, Zostera noltii, Z marina, Z. capricorni, Cymodocea nodosa and Posidonia oceanica, sampled across different climatic zones and depths, also revealed a similarity with terrestrial plants, both in carotenoid composition and in the pigment-based photoprotection mechanisms. Cymodocea nodosa plants from Ria Formosa were submitted to the combined effect of potentially stressful light and temperature ranges and showed considerable physiological tolerance, due to the combination of changes in the antioxidant system, activation of the VAZ cycle and accumulation of leaf soluble sugars, thus preventing the onset of oxidative stress. Cymodocea nodosa plants living in a naturally acidified environment near submarine volcanic vents in Vulcano Island (Italy) showed to be under oxidative stress despite the enhancement of the antioxidant capacity, phenolics concentration and carotenoids. Posidonia oceanica leaves loaded with epiphytes showed a significant increase in oxidative stress, despite the increase of antioxidant responses and the allocation of energetic resources to these protection mechanisms. Globally, the results show that seagrasses are physiologically able to deal with potentially stressful conditions from different origins, being plastic enough to avoid stress in many situations and to actively promote ulterior defence and repair mechanisms when under effective oxidative stress.
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The fact that the adult brain is able to produce new neurons or glial cells from neural stem cells (NSC) became one of the most interesting and challenging fields of research in neuroscience. Endogenous adult neurogenesis occurs in two main regions of the brain: the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) in the dentate gyrus. Brain injury may be accompanied by increased neurogenesis, although neuroinflammation promotes the activation of microglial cells that can be detrimental to the neurogenic process. Nitric oxide (NO) is one of the factors released by microglia that can be proneurogenic. The mechanism by which NO promotes the proliferation of NSCs has been intensively studied. However, little is known about the role of NO in migration, survival and differentiation of the newborn cells. The aim of this work was to investigate the role of NO from inflammatory origin in proliferation, migration, differentiation and survival of NSCs from the dentate gyrus in a mouse model of status epilepticus. We also assessed neuroinflammation in the same injury model. Our work showed that NO increased proliferation of the early-born cells after seizures, but is detrimental for their survival. NO also increased migration of neuroblasts. Moreover, NO was important to maintain long-term neuroinflammation. Taken together, these results show that NO may be a good target to promote proliferation and migration of NSCs following seizures, but compromises survival of early-born cells.
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Tese de doutoramento, Ciências do Mar, da Terra e do Ambiente (Modelação), Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014
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Dissertação de Mestrado, Gestão Costeira, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Universidade do Algarve, 1996
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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidadde do Algarve, 2015
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Dissertação de mestrado, Arquitetura Paisagista, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Tese de doutoramento, Turismo, Faculdade de Economia, Universidade do Algarve, 2015
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Dissertação de mestrado, Tecnologia de Alimentos, Instituto Superior de Engenharia, Universidade do Algarve, 2015
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Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Univerdade do Algarve, 2015