Repositório RCAAP

As simbioses entre espécies representam adaptações face a mudanças ambientais no meio marinho. Uma das simbioses mais carismáticas é o mutualismo entre peixes limpadores e os seus clientes. Estes ocupam territórios específicos conhecidos como “estações de limpeza” e prestam um serviço aos seus clientes, comendo ectoparasitas e tecidos mortos. Para interagir com os seus clientes os bodiões limpadores (Labroides dimidiatus) desenvolveram um conjunto de ferramentas cognitivas e comportamentais. No entanto, as condições em que estas simbioses evoluíram estão a mudar devido ao aquecimento e à acidificação dos oceanos. Esta dissertação tem como objetivo compreender como as simbioses de limpeza respondem ao aquecimento e à acidificação dos oceanos (AAO), utilizando uma abordagem integrativa. Mais especificamente, esta dissertação centrou-se em duas questões principais: 1) “O comportamento cooperativo de limpeza é afetado por AAO? Quais são os mecanismos neurobiológicos e há potencial para adaptação? ” e 2)“ Os parasitas são resistentes a AAO? Como estes afetam os peixes e como a sua abundância pode ser controlada? ”. Nos capítulos 2 e 3, é revelado que AAO pode afetar o comportamento de limpeza através de disrupção dos sistemas neurobiológicos. Por outro lado, o Capítulo 4 demonstra que o desempenho cognitivo do peixe limpador, embora afetado pela acidificação, ainda apresenta potencial de adaptação. Em relação à segunda questão, o capítulo 5 revela que os ectoparasitas são tolerantes à acidificação. No capítulo 6, apenas clientes sem acesso a serviços de limpeza foram fisiologicamente afetados pela acidificação. Por fim, o capítulo 7 mostra que os corais controlam a abundância de parasitas e a perda de corais devido a eventos extremos pode diminuir a predação de parasitas. Em conclusão, esta dissertação mostra que o AAO podem perturbar as simbioses da limpeza através de alterações comportamentais causadas por perturbações neurobiológicas. Embora exista algum potencial de adaptação, a combinação destes stressores climáticos e a imprevisibilidade de eventos extremos tornam a probabilidade de adaptação menor. Por último, é importante frisar que esta disrupção de simbioses da limpeza pode levar a efeitos de cascata nos ecossistemas dos recifes de coral, uma vez que a necessidade de peixes nos serviços de limpeza pode aumentar com uma maior abundância de ectoparasitas gnatídeos tolerantes a CO2 (devido à diminuição no controlo da abundância).

A qualidade das plantas para os herbívoros depende de características da planta (e.g. nutrientes e defesas), de fatores abióticos (e.g. metais) e da presença de outros herbívoros e antagonistas na planta. O intuito desta tese foi caracterizar o efeito de diferentes qualidades da planta nas interações planta-herbívoro e herbívoro-herbívoro nos ácaros-aranha, Tetranychus urticae e T.evansi. Primeiro descrevemos a criação de populações com elevada consanguinidade e com elevada diversidade, ferramentas com importantes aplicações em estudos laboratoriais, que utilizámos durante a tese. Depois, estudámos o efeito da competição interespecífica na distribuição dos ácaros na planta. Em plantas sem heterospecíficos ambas as espécies tiveram maior desempenho reprodutivo em folhas jovens, preferindo colonizar estas. Em plantas com heterospecíficos esta preferência perdeu-se, substituída por diferentes comportamentos em resposta aos heterospecíficos. T. urticae evitando folhas com o competidor e T. evansi distribuindo-se uniformemente entre as folhas. T. urticae também aumentou a dispersão de hospedeiros com T. evansi. Não encontrámos, no entanto, uma correlação genética entre o dano causado à planta e dispersão para outro hospedeiro. O desempenho reprodutivo das duas espécies também mostrou ser afetado da mesma forma pela acumulação de cádmio em tomateiros, correspondendo a uma resposta hormética. Durante exposições mais longas T. evansi mostrou ser mais negativamente afetado pela acumulação de cádmio do que T. urticae. Não houve interações entre a indução/supressão de defesas do tomateiro (inibidores de proteínas) e acumulação de cádmio, sendo este último um mecanismo passivo, não induzido por herbivoria. Finalmente, mostrámos variação intraespecífica nos ácaros, na resposta hormética à acumulação de cádmio em tomateiros, sendo a hormesis potenciada diretamente pelo metal e não por alterações na planta. Esta tese demonstra a importância do sistema planta-metal-ácaro no estudo das consequências ecológicas da acumulação de metais e revelou novas perspetivas sobre as interações entre T. urticae e T. evansi em diferentes contextos.

If we are interested in the way people understand art, this means that there must be something in art that it is worth being understood. Increasingly, education should be intrinsically coupled with the world of art, as it is a world in which one’s own personal affirmation and creativity take a prominent place in the life of every human being. This thesis has intended to verify that the contact between children in nursery school and images of works of art and visual culture helps them to acquire new knowledge in the context of aesthetics and visual language, as well as it leaves them more and more comfortably to express their feelings and opinions. Through an action research methodology carried out in the classroom with children aged 5-6 years old, it was noticed that the veracity of the initial hypothesis, that is, children who regularly live together with the world of art (works of art or images of works of art and visual culture), not only learn to look at it, trying through their own experiences their reading of sense, but also start to understand a new language, the visual one, which comes from the aesthetic reflection and appreciation they are submitted to. Children will restructure their understanding as far as their knowledge of visual culture increases, which, in this case, turns into a better comprehension of the observed works and the images that integrate their involvement

Among climate extremes, droughts are a major source of risk to agriculture and food security, which are expected to be increasingly affected considering the tendency towards a warmer climate. Within the context of climate change, the Iberian Peninsula (IP) is one of the regions recurrently highlighted as one of the areas expected to be particularly affected by drought episodes, due to the strong variations in the precipitation regime that make the region prone to drought events. In this way, this dissertation aimed the development of an agricultural drought risk model to contribute to more resilient systems in the IP. The skills of several drought indicators (SPEI, VCI, TCI and VHI) in predicting wheat and barley yields were firstly assessed based on neural networks and multiple linear regression models. Afterwards, copula-based models were designed to assess the joint probability of crop yields and droughts for a probabilistic risk assessment. The agricultural drought risk was then defined as the conditional probability of crop-loss under drought conditions and mapped at the province level of the IP. Ultimately, the additional risk associated with the occurrence of extreme temperatures during droughts was evaluated to characterize how the interaction between dry and hot conditions may exacerbate the impacts of the individual hazards in agriculture. The results showed the good performance of drought indicators in predicting the occurrence of crop failures. In general, barley exhibits greater agricultural drought risk in comparison to wheat. Overall, the risk of crop-loss increases with the severity of drought conditions, and drought-related risks increase with the interaction with extreme temperatures. Although compound dry and hot conditions lead to the larger damages in crop yield than the individual drought- or heat-stress, drought is still the dominant factor. From an operational point of view, this research intends contributing to the agricultural decision-making.

Esta Newsletter (NL) resulta de uma parceria entre o Instituto de Saúde Baseada na Evidência e a Cochrane Portugal, e tem como objectivo disponibilizar informação sobre áreas interessantes para a prática clínica, com base na melhor evidência científica. São incluídos estudos relevantes, criticamente avaliados pela sua validade, importância dos resultados e aplicabilidade prática, resumidos numa óptica de suporte à decisão. É dada prioridade a estudos de causalidade incluindo-se ainda, quando justificado, estudos qualitativos e metodológicos, assim como revisões científicas. O conteúdo da NL é da exclusiva responsabilidade do(s) seu(s) autor(es).

Cystic Fibrosis (CF) is caused by mutations in the CFTR gene. The relationship between CFTR and differentiation has been firmly documented. However, the mechanisms that regulate this relationship are still unclear. The aim of this work was to further characterize the differentiation defect in CF and to identify the underlying molecular mechanisms. In the first chapter, our results show that CF cells display increased proliferation, acquire lower levels of TEER upon polarization, display slower wound healing, and have altered differentiation. Moreover, our data suggest that partial epithelial-mesenchymal transition occurs in CF cells. Given that Krüppel-like factors (KLFs) play pivotal roles in the regulation of differentiation, in the second chapter we tested the levels of KLF2, 4 and 5 and found that only KLF4 is differentially expressed in CF vs non-CF cells. Therefore, we then assessed whether KLF4 modulation had an impact in CFTR levels and function. Our data show that KLF4 acts as a negative regulator of wt-CFTR expression and function. Noteworthy, F508del cells are relatively insensitive to KLF4 modulation. Next, we tested possible pathways by which KLF4 action can impact CFTR in the CF and non-CF contexts. Our data showed that AKT signalling acts as a modulator of CFTR in a KLF4-dependent way, whilst GSK3β was observed to be a negative regulator of CFTR independent of KLF4 in CF cells. In chapter three, our data show that KLF4 knock-out has no major impact in proliferation but modulates TEER acquisition, wound healing, and differentiation markers differentially in CF vs non-CF cells. Moreover, we characterized the levels of KLFs, CFTR and proteins of interest during epithelial differentiation and showed that maximum KLF4 expression occurs prior to maximum CFTR expression. Altogether these data contribute to mechanistic clarification of the relationship between CFTR and epithelial differentiation.

In clinical decision making, myocardial viability is defined as myocardium in acute or chronic coronary artery disease and other conditions with contractile dysfunction but maintained metabolic and electrical function, having the potential to improve dysfunction upon revascularization or other therapy. Several pathophysiological conditions may coexist to explain this phenomenon. Cardiac imaging may allow identification of myocardial viability through different principles, with the purpose of prediction of therapeutic response and selection for treatment. This expert consensus document reviews current insight into the underlying pathophysiology and available methods for assessing viability. In particular the document reviews contemporary viability imaging techniques, including stress echocardiography, single photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and computed tomography and provides clinical recommendations for how to standardize these methods in terms of acquisition and interpretation. Finally, it presents clinical scenarios where viability assessment is clinically useful.

Purpose: Current treatment recommendations emphasize early loading, with preservation of tendon length and physiologic tension. The objective of this systematic review and network meta-analysis was to compare failure load and elongation after cyclic loading of Achilles tendon repair techniques at time-zero. Methods: The databases PubMed, CENTRAL and Web of Science were searched for all published in-vitro studies comparing Achilles tendon repair techniques, or augmentation with autografts/biomaterials, and reports of failure load or elongation after cyclic loading. Only studies using human cadaveric Achilles tendons and matched pairs, or randomized specimen allocation, were selected for quantitative synthesis. A network meta-analysis per primary outcome was performed. Results were summarized as P score rankings and their validity was assessed using statistical methods. Results: Sixteen studies, comprising 367 tendon repairs, were included. The following repair techniques were used (n = number of studies): Krackow (n = 8), Achillon (n = 4), double Krackow (n = 3), Bunnell (n = 3), Percutaneous Achilles Repair System (n = 3), Percutaneous Achilles Repair System Midsubstance (n = 2), Kessler (n = 3), double Kessler (n = 1), modified triple Kessler (n = 1), triple bundle (n = 1), a multifilament stainless steel cable-crimp technique (n = 1) and a double loop knot stitch (n = 1). Five studies assessed augmentation with autografts/biomaterials. Regarding the failure load, biomaterial augmented Krackow repairs occupied the first four positions in the ranking, followed by the multifilament stainless steel cable-crimp and Percutaneous Achilles Repair System Midsubstance techniques. Concerning elongation after cyclic loading, the triple Kessler was ranked first, followed by the Achillon and Percutaneous Achilles Repair System Midsubstance techniques. A negligible correlation between ranks was found (rs = 0.11; p = 0.75n.s.), meaning that a higher repair tensile strength is not necessarily related to improved performance in regard to avoidance of elongation. Conclusion: In the failure load network meta-analysis, biomaterial augmented Krackow repairs ranked highest, but noticeable statistical heterogeneity was found. Regarding elongation with cyclic loading, the modified triple Kessler stitch showed the highest probability of ranking first.

A proper determination of the exercise intensity is important for the rehabilitation of patients with cardiovascular disease (CVD) since it affects the effectiveness and medical safety of exercise training. In 2013, the European Association of Preventive Cardiology (EAPC), together with the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation, published a position statement on aerobic exercise intensity assessment and prescription in cardiovascular rehabilitation (CR). Since this publication, many subsequent papers were published concerning the determination of the exercise intensity in CR, in which some controversies were revealed and some of the commonly applied concepts were further refined. Moreover, how to determine the exercise intensity during resistance training was not covered in this position paper. In light of these new findings, an update on how to determine the exercise intensity for patients with CVD is mandatory, both for aerobic and resistance exercises. In this EAPC position paper, it will be explained in detail which objective and subjective methods for CR exercise intensity determination exist for aerobic and resistance training, together with their (dis)advantages and practical applications.

Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease.

Mesenchymal stem cells (MSCs) have emerged as a promising strategy to the repair of damaged tissues, due to characteristics such as immunomodulation, anti-inflammatory properties, homing, protective and reparative effects. Additionally, MSCs have shown to exert their therapeutic activity by homing into injured tissues, cellular crosstalk and inducing tissue regeneration response through paracrine signalling, namely through exosomes. This thesis aimed to evaluate the role of the secretome (CM) and exosomes (Exo) derived from umbilical cord tissue (UC)-MSCs for damaged tissue treatment. Three-dimensional (3D) cultures were employed to prime UC-MSCs towards a healing-inducing secretome (CM3D); whereas the mechanism by which Exo/CM induced tissue regeneration was further explored including the stimulation of endogenous regeneration programmes. The use of two disease models, rheumatoid arthritis, and cutaneous wounds, highlighted the different UC-MSC functions, namely their immunomodulatory and tissue regeneration abilities. Moreover, the administration of CM3D in adjuvant-induced rat model for arthritis, ameliorated the arthritic signs and accelerated the remission of local and systemic arthritic manifestations. The analysis of relevant trophic factors in CM3D confirmed the prevalence of anti-inflammatory cytokines, along with trophic factors involved in different mechanisms leading to tissue regeneration. Accordingly, CM3D-treated wounds also presented signs of faster and better wound resolution, with a more mature vascular system already showing glands and hair follicles. Deeper and integrated analysis of the secretome unveiled the role of exosomes and its content on cutaneous wound healing. Furthermore, loading of Exo with an immunosuppressive oligodeoxynucleotide resulted in reduced systemic levels of pro-inflammatory cytokines at the late stage of wound healing. Lastly, mechanistic studies disclosed the role of granulocyte colony-stimulating factor (G-CSF) on UC-MSC homing and recruitment capacities that further contributed to accelerated closure of impaired wounds. Overall, this thesis set up the technical grounds for the development of an effective and novel advanced therapy medicinal product (ATMP) for injured tissue treatment.

O Capítulo 1 apresenta os principais desafios clínicos em idosos com diabetes tipo 2 e enfatiza a lacuna de conhecimento a respeito de duas das síndromes geriátricas mais importantes, a polifarmácia e o tratamento excessivo em ensaios clínicos randomizados e diretrizes de prática clínica. Para preencher essa lacuna de conhecimento na prática clínica de rotina, uma revisão sistemática e metanálise de estudos observacionais, de coorte e de desenho transversal, seguido por três estudos de desenho observacional e transversal, com os critérios de inclusão de ser idosos com tipo 2 diabetes e com 65 anos ou mais foram todos conduzidos e implementados no Capítulo 2. Uma breve descrição dos métodos de pesquisa foi apresentada no Capítulo 2.1. Os resultados da revisão sistemática e da meta-análise (Capítulo 2.2) mostraram que a polifarmácia em idosos com diabetes tipo 2 foi associada de 62%, 96%, 33% e 72% de probabilidade de mortalidade, enfarte do miocárdio, acidente vascular cerebral e hospitalização, respectivamente. A análise de dados baseados em farmácia (Capítulo 2.3) revela que a polifarmácia, interações medicamentosas potencialmente graves e clinicamente relevantes e medicamentos potencialmente inadequados foram associados a 80%, 34% e 57% de chances de menor qualidade de vida relacionada à saúde em idosos adultos com diabetes tipo 2, respectivamente. A análise de uma base de dados administrativa (Capítulo 2.4) mostrou que a polifarmácia e medicamentos potencialmente inadequados foram associados a probabilidades 2 a 2.5 vezes maiores de alteração do controle glicêmico, e os medicamentos potencialmente inadequados também podem estar associados a 5.5 vezes maior probabilidade de alterações da função renal graves em adultos idosos com diabetes tipo 2. Além disso, a análise de dados administrativos de instituições especializadas em tratamento de diabetes (Capítulo 2.5) também conclui que mais de 60% dos adultos mais velhos com diabetes tipo 2 foram potencialmente supertratados e mais de 12% foram potencialmente subtratados. Os doentes com sobretratamento, mostraram ser mais homens, pré-obesos, têm maior compromisso macrovascular, neuropatia e pé diabético, e associados estão a uma maior prevalência de doença renal crônica grave. Os doentes, e potencialmente subtratados eram maioritariamente do sexo feminino, obesos, com uma maior prevalência de dislipidemia , doenças vasculares periféricas, infecções e pé diabético, e usavam mais insulina em comparação com aqueles que cumpriam os objectivos terapêuticos. No capítulo (Capítulo 3), apresenta-se uma discussão compreensiva dos resultados. Os estudos realizados mostraram que a polifarmácia e o sobretratamento em idosos com diabetes tipo 2 podem estar associados a vários resultados relacionados com a saúde na prática clínica do mundo real, onde estes conceitos são subestimados em ensaios clínicos randomizados e diretrizes de prática clínica, que podem induzir mais danos do que benefícios. A terapia individualizada dos doentes e a otimização da medicação podem ser a maneira de reduzir o risco dessas importantes síndromes geriátricas.

A atividade antropogénica está a libertar dióxido de carbono para a atmosfera, que se traduz em alterações físicas e químicas dos nossos oceanos outrora pristinos. Os níveis de dióxido de carbono estão a aumentar a uma velocidade sem precedentes o que resulta no aumento de temperatura (incluindo um aumento de ondas de calor marinhas) e acidificação dos oceanos. Simultaneamente as populações de tubarões estão a diminuir e, como elementos essenciais dos ecossistemas marinhos, é imperativo determinar a sua vulnerabilidade aos potenciais riscos que um oceano em mudança acarreta. Assim, o objetivo da presente dissertação foi investigar os impactos que uma onda de calor marinha e a acidificação dos oceanos poderão ter na ecofisiologia de tubarões temperados (Scyliorhinus canicula) e tropicais (Chiloscyllium plagiosum) juvenis bentónicos, incluindo respostas de stress oxidativo, parâmetros hematológicos, crescimento e performance natatória. Os resultados sugerem que a espécie temperada estudada é mais sensível ao aquecimento que à acidificação, uma vez que a exposição a uma onda de calor marinha alterou a contagem de células sanguíneas e aumentou a taxa de ventilação enquanto a acidificação não surtiu efeitos significativos. Além disso, a acidificação só afetou a espécie tropical estudada, uma vez que uma curta exposição foi suficiente para reduzir a taxa de crescimento, o tempo de natação e a atividade da acetilcolinesterase no cérebro. Os impactos observados parecem indicar alguma resiliência às alterações climáticas. Contudo, até estes efeitos subletais podem reduzir o estado físico e a sustentabilidade destes tubarões a longo curso, com potenciais efeitos cascata ao longo do ecossistema.

This research project is about the art work of Joana Vasconcelos, intends to challenge the issue of feminism present in many of their artistic creations, highlighting, simultaneously, in the informal context, visual education and citizenship. It’s, at one time, the assumption of the educational functionality of Art in a non-networked role controversial, challenging, mobilizing and dynamic. The Artist as a persona that moves in a single weaving, where to be it’s having in your hands the thread of the viewer's gaze, which draws crowds, influencing a new generation, a whole new stream of public. Revere here studies on the art of education by some authors who contributed to a significant change in arts education and contributed to the human being becomes more complete, gifted with sensitivity and sense. We call on gender studies, including exhortations about feminism, to explain their historical achievements such as human and who have cooperated in a social development which gained equality between men and women. Thus we talk about the merging of art and feminism by showing examples and opportunities created and achieved by women in a world dominated by men. Constant fights that have lasted to these days. Finally our thread of Ariadne, the artist Joana Vasconcelos, shows us how to take on feminine identity, a mix of attraction and retraction upon to clarify the concept. It turns out the duplicity, the duality, in short, the ambiguity in the work as much in the speech. The process of informal education, formal fascination, but rather the action of citizenship exercised by his works the viewer can go for some unseen, however they shouldn’t be ignored

Upstream open reading frames (uORFs) are cis-acting elements located within the 5’ leader sequence (or 5’ untranslated region; 5’UTR) of transcripts that can regulate translation of the correspondent main open reading frame (mORF). During basal conditions, uORFs are typically considered to be repressors of downstream translation, as they can impede the ribosomes to access the mORF or even induce mRNA degradation by the nonsense-mediated mRNA decay (NMD) pathway. However, during stress conditions, phosphorylation of the eukaryotic initiation factor 2α (eIF2α) allows the expression of several stress-responsive proteins through uORF-mediated mechanisms, while global mRNA translation is inhibited. During endoplasmic reticulum (ER) stress, for instance, the accumulation of unfolded proteins leads to activation of the ER-resident PKR-like ER kinase (PERK) that phosphorylates eIF2α as part of the stress-protective mechanisms of the unfolded protein response (UPR) and the integrated stress response (ISR). This results in the selective uORF-mediated translation of downstream effectors, like the activating transcription factor 4 (ATF4), the CCAAT-enhancer-binding protein homologous protein (CHOP) and the growth arrest and DNA damage-inducible protein 34 (GADD34), which drive stress resolution or, in the case of a prolonged stress, cell death. The dual role of PERK in regulating cell fate has been reported to be involved in the outcome of several human diseases, including diabetes, neurodegenerative disorders and cancer. Moreover, mutations in the EIF2AK3 gene that encodes PERK have been implicated in the development of the rare genetic disease, Wolcott-Rallison Syndrome (WRS). Interestingly, data from ribosome-profiling (Ribo-seq) studies suggested the existence of uORFs within PERK 5’UTR, which could be involved in the regulation of PERK expression. In this work, we aimed to study the translational regulatory role of five AUG- and three non-AUG-uORFs identified in the PERK 5’UTR and assess its impact in cell homeostasis and human disease. While uORF2 and the non-AUG-uORFs 5, 6 and 7 do not seem to have a significant regulatory role, uORF1, uORF3, uORF4 and uORF8 together present a strong repressive effect over mORF translation in basal conditions, possibly by providing a barrier to the scanning ribosomes and precluding translation reinitiation at the mORF, without affecting the PERK mRNA levels. Curiously, we found that when we induce PERK overexpression, it leads to the spontaneous activation of a portion of PERK in the absence of any stress stimulus, possibly highlighting the biological relevance of its uORF-mediated translational regulation in maintaining its physiological basal levels. Conversely, during stress conditions, increased bypass of uORF1 results in a modest degree of translational de-repression, which may help to counterbalance the increased rate of PERK protein turnover observed in these conditions. We also found that alteration of the PERK uORFs by mutations found in WRS patients modify PERK expression, providing a possible link with the disease phenotype. Finally, we tested the impact of PERK unbalanced expression in the viability of HCT116 cells but, at least in our experimental conditions, no differences were found. Altogether, we provide a new example of a transcript containing uORFs that fine-tune mORF translation. Moreover, we highlight the importance of including 5’UTRs, like the one of PERK, in the screening of disease-related mutations and the necessity of functional studies to assess their relevance in the pathogenesis of human diseases. This may provide vital information for the development of new therapeutic strategies.

A long-term history of multi-functional management and natural disturbances have transformed many woodlands of Europe into unique landscapes that integrate forests, open grazed pastures with scattered shrubs and trees, in addition to various semi-natural vegetation elements. These landscapes, named wood-pastures, often represent economically valuable and biodiversity-rich habitats with a characteristic semi-open and heterogeneous vegetation structure and can be found throughout different European bioregions. In the Western Mediterranean the most important types of wood-pastures have a tree cover dominated by oaks and are known as “montados” (in Portugal) and dehesas (in Spain). Wood-pastures are increasingly fragile due to conflicting land-use regimes associated with intensification and abandonment, which influence vegetation structure and overall habitat heterogeneity leading to impacts on biodiversity and ecosystem processes. This situation highlights the urgent need to improve low-cost and biodiversity-friendly management strategies that have minimal negative effects on production to preserve the balance between natural and economic values of wood-pastures. The main objective of this thesis, which focuses on Mediterranean woodpastures, is to explore the biodiversity patterns of multiple taxa using the advantages of functional diversity approaches to reveal how land-use driven changes influence biodiversity, ecosystem functioning and ecosystem services in wood-pastures, and use these insights to improve sciencebased, sustainable management plans. For these aims, this thesis evaluated the role of small ungrazed patches within the wood-pasture matrix in enhancing (1) taxonomic and (2) functional diversity of multi-taxa (plants, beetles, lichens). The results revealed the contribution of allowing shrub growth within ungrazed patches to species richness and functional diversity of plants, beetles and lichens by facilitating the presence of distinct species and trait assemblages compared to woodpasture matrix. This work also assessed how changes in habitat structure associated with a management intensity gradient ranging from active management towards land abandonment affected (3) species and trait assemblages of breeding birds in wood-pastures and (4) of insectivore birds in particular to evaluate the potential consequences for natural pest regulation in woodpastures. The findings showed the role of sustaining non-intensive and active management, which prevented excessive shrub growth and loss of habitat heterogeneity, in facilitating the distribution of more diverse bird guilds and in potential contributions to the natural pest control provision in woodpastures. Overall, the key findings of this thesis highlight the importance of maintaining small ungrazed patches and non-intensive, active management strategy to preserve the semi-open and heterogeneous habitat structure that increase biodiversity of plants, beetles, lichens and birds, leading to positive influences on ecosystem functioning and service provision in wood-pastures. Finally, this work contributes to ongoing efforts to improve low-cost and sustainable management actions conciliating the natural and economic values of wood-pastures.

Os nanomateriais (NMs) apresentam características físico-químicas únicas que os tornam ideais para várias aplicações em inúmeras áreas. Com o incremento do uso de NMs em algumas indústrias e produtos de consumo, entre outros, a exposição humana e ambiental a essas substâncias tem aumentado cada vez mais, sendo necessários mais estudos para compreender os potenciais perigos associados a essa exposição. Atualmente, o ensaio do micronúcleo (MN) é um dos testes mais utilizados na avaliação da genotoxicidade de substâncias sendo considerado mais vantajoso quando comparado com outros testes similares. Mesmo sendo um teste apropriado, a comparação dos resultados do ensaio MN é difícil devido aos resultados inconsistentes reportados. Assim, há a necessidade de desenvolver protocolos harmonizados e selecionar as linhas celulares mais sensíveis, dadas as particularidades dessas substâncias, a fim de validar técnicas como esta. Este trabalho, que se insere num estudo internacional mais amplo envolvendo comparações interlaboratoriais, tem como objetivo otimizar o ensaio do micronúcleo in vitro de forma a obter um ensaio mais sensível e fiável para a avaliação da genotoxicidade dos NMs em linhas celulares de mamíferos. Foi avaliada a toxicidade de NMs, nomeadamente, dióxido de cério (CeO2), sulfato de bário (BaSO4), sílica (SiO2), celulose nanofibrilada (CNF) e celulose nanocristalina (CNC), todos eles com aplicações variadas na indústria e produtos de consumo. Fibroblastos de pulmão de hamster chinês (células V79) foram expostos a diferentes concentrações de cada NM durante 1 ciclo celular (17 horas) para avaliação da citotoxicidade através do ensaio MTT e por 4 dias através do ensaio clonogénico. A genotoxicidade foi avaliada pelo ensaio do MN após exposição durante 17 horas às mesmas concentrações dos NMs. Os resultados mostraram uma diminuição significativa da viabilidade celular após exposição ao BaSO4 nas concentrações mais elevadas (64, 128 e 256 μg/mL). A exposição por 4 dias a BaSO4, CNF ou CNC levou a um decréscimo da proliferação celular, verificando-se efeitos citotóxicos positivos para esses NMs. Quanto a efeitos genotóxicos, avaliados pelo ensaio do MN, os resultados revelaram aumento significativo de frequência de células micronucleadas após exposição a CNF, assim como à concentração mais baixa de BaSO4. Os NMs de CeO2 e SiO2 não revelaram ser genotóxicos. O conhecimento gerado através deste trabalho contribuirá para o conjunto de dados produzidos através do uso do ensaio do MN in vitro para a avaliação da genotoxicidade dos NMs. Os resultados obtidos para os diversos NMs avaliados sugerem que o protocolo utilizado para o ensaio de MN permitiu distinguir efeitos diferenciais quanto à sua genotoxicidade. Além disso, os resultados gerados contribuirão para a avaliação de segurança dos NMs em estudo, contribuindo assim para sua aplicação segura na indústria, produtos de consumo e nanoteranósticos. Uma futura comparação interlaboratorial permitirá avaliar a reprodutibilidade e adequação do ensaio, considerando as características físico-químicas dos NMs em teste, e o uso de protocolos padronizados melhorará a comparação dos resultados.

Habitat loss and fragmentation have long been recognized as major drivers of biodiversity depletion. In Amazonia, forest fragmentation constitutes a major cause of environmental stress for many organisms. Here, we addressed the effects of differential fragment sizes on the mandible phenotype of four species of small mammals (Proechymis longicaudatus, Necromys lasiurus, Micoureus demerarae and Monodelphis glirina) using a geometric morphometry approach. This technique allowed to address: i) the symmetrical component, assessing population variation in shape and size; ii) fluctuating asymmetry, inferring disturbance during embryonic development; iii) morphological integration and modularity, allowing to identify deviations in the mandible’s morphological structure. The study area encompasses a hyper-fragmented area in southern Amazonia, characterised by forest landscape surrounded by pasture, with some highly isolated patches. Sampling and data collection were performed in 17 forest fragments grouped according to size: ten small fragments (4-26 hectares), seven large fragments (106-1763 hectares), and two surrounding areas of continuous forest (C≥30,000 hectares). Our results reveal that morphometric distances between groups of animals inhabiting different sized fragments are significantly higher when pairwise comparison involve small fragments. Fluctuating asymmetry was also significantly higher in small fragments but only for both species of larger body size (long- tailed spiny rat, P. longicaudatus, and woolly mouse opossum, M. demerarae). More isolated fragments were positively correlated with higher fluctuating asymmetry levels, although not significantly. Finally, in small fragments, changes in the expected pattern of modularity and morphological integration were also detected for all but one study species (M. demerarae), with putative consequences for the structure and morphological functionality of individuals. Based on empirical morphological data, we highlight the need for the maintenance of large forest patches as repositories of somewhat similar levels of morphological diversity and functionality in contrast with small fragments, where most deleterious effects were detected.

The Cape Verde archipelago is an interesting region to study plate-hotspot interactions, considering hotspots as enigmatic surface features that are not easily explained in the plate tectonics theory. The horseshoe geometry and the surrounding seafloor morphology and bathymetry of the Cape Verde archipelago play a significant role in the generation of ambient seismic noise in this region. In order to improve ambient noise based studies, it is important to understand the distribution of the sources of ambient noise, as they affect the estimates of empirical Green's function, and consequently the resulting isotropic and anisotropic tomographic models of velocity and attenuation. We analyzed microseisms recorded in Cape Verde and determined the number of signals polarized as Rayleigh waves, as well as their back azimuth as a function of time and frequency. We determined that the local bathymetry around the Cape Verde Islands strongly amplifies local secondary microseismic sources. Furthermore, we confirmed that Cape Verde stations mostly record local sources. In order to study the properties of the crust and upper mantle below Cape Verde, we performed surface wave studies using two different types of data: ambient noise and teleseismic data. By applying a recent implementation of the surface-wave two-station method we measured the phase velocities of Rayleigh-wave fundamental modes in a broad period range (8–250 s). This method is based on cross-correlating teleseismic earthquake seismograms between pairs of stations. From these signals, we derived a robust, average, phase-velocity curve for the Cape Verde region, which we inverted in order to obtain a shear-wave velocity profile. Our results show significantly low velocities of ∼ 4.2 km/s in the asthenosphere, indicating the presence of anomalously high temperatures and, eventually, partial melting. The temperature anomaly is probably responsible for the thermal rejuvenation of the lithosphere to an effective age as young as about 30 Ma. For ambient-noise tomography we computed phase cross-correlations between all station pairs, which were then stacked, yielding empirical Green's functions. Based on these, we derived group-velocity maps for the period band between 10 - 24 s and the corresponding 3D shear-wave velocity structure. The final tomographic model shows the main velocity anomalies, which are associated with tectonic and volcanic activity in Cape Verde. A clear low-velocity anomaly is observed beneath the active volcanic area of the Fogo - Brava islands. This anomaly extends to the islands of Boavista and Maio, even though with less expression. On the contrary, the islands of the Northwestern group display velocities higher than the average at all depths.

The Figueira de Castelo Rodrigo–Lumbrales Anatectic Complex (FCR-LAC) is an example of a granite-migmatite complex formed during the Variscan Orogeny located within the autochthonous terrane of the Central Iberian Zone. The FCR-LAC contacts with an Ediacaran–Cambrian metasedimentary sequence (Douro–Beiras Supergroup – DBSG) through the Huebra and Juzbado–Penalva do Castelo shear zones. New U–Pb zircon and apatite ages constrain emplacement and migmatization ages, inherited ages and unprecedented cooling rates for the FCR–LAC lithologies. The granites emplacement ages cluster around 313–317 Ma while the migmatization age constrains the prograde metamorphic path (344 – 315 Ma) and the metamorphic peak at 316.8 ± 2.0 Ma. The migmatization/peak metamorphic ages suggest that the anatexis started during the D2 and culminated during the D3 Variscan phase, concomitantly with the emplacement of the S-type granites. The cooling (7 to 54 ºC/Ma) and exhumation rates (0.2 and 1.3 mm a-1) of the FCR–LAC imply fast cooling/exhumation conditions which are compatible with a tectonically-assisted mechanism where the shear zones have an important role. The elemental composition of the FCR-LAC reveals the existence of two distinct diatexite groups: diatexites type-1 produced via dehydration-melting of muscovite; and the diatexites type-2 formed by a fluid-present melting reaction. These two diatexite groups evolved in different stages of the prograde metamorphic path: 343.7 ± 2.5 Ma for diatexite type-2, 328.8 ± 3.4 Ma for a diatexite type-1, culminating in the metamorphic peak at 318.8 ± 2.6 Ma with a diatexite type-1. The different melting reactions justify the isotopic variability observed in the FCR-LAC. The U-Pb detrital zircon ages of the FCR-LAC and the DBSG reveal an important input of the Cadomian sediments. The zircon distribution ages of the Pinhão Formation (Douro Group) compared to the Beiras Group reinforce the existence of a physical barrier at south of the FCR-LAC. Younger inherited zircon from the anatectic rocks can be linked to the Ollo de Sapo magmatic rocks indicating that they melted alongside the DBSG showing the existence of source heterogeneity. This fact is also supported by the Sr-Nd isotopic compositions of the FCR-LAC and explains the existence of two groups with distinct initial isotopic compositions, both composed by metatexites, diatexites and granites.