RCAAP Repository

Bases de dados de entidades científicas, como compostos químicos, doenças e objetos astronómicos, têm crescido em tamanho e complexidade, chegando a milhares de milhões de itens por base de dados. Os investigadores precisam de ferramentas novas e inovadoras para auxiliar na escolha desses itens. Este trabalho propõe o uso de Sistemas de Recomendação para auxiliar os investigadores a encontrar itens de interesse. Identificamos como um dos maiores desafios para a aplicação de sistemas de recomendação em áreas científicas a falta de conjuntos de dados padronizados e de acesso aberto com informações sobre as preferências dos utilizadores. Para superar esse desafio, desenvolvemos uma metodologia denominada LIBRETTI - Recomendação Baseada em Literatura de Itens Científicos, cujo objetivo é a criação de conjuntos de dados <utilizador, item, classificação>, relacionados com campos científicos. Estes conjuntos de dados são criados com base no principal recurso de conhecimento que a Ciência possui: a literatura científica. A metodologia LIBRETTI permitiu o desenvolvimento de novos algoritmos de recomendação específicos para vários campos científicos. Além do LIBRETTI, as principais contribuições desta tese são conjuntos de dados de recomendação padronizados nas áreas de Astronomia, Química e Saúde (relacionado com a doença COVID-19), um sistema de recomendação semântica híbrido para compostos químicos em conjuntos de dados de grande escala, uma abordagem híbrida baseada no enriquecimento sequencial (SeEn) para recomendações sequenciais, um pipeline baseado em semântica de vários campos para recomendar entidades biomédicas relacionadas com a doença COVID-19.

Aims. – To test the influence of caffeine on the lower and upper motor neuron excitability. Methods. – In Experiment A, 18 healthy subjects received 200 mg of caffeine or placebo, in a randomized, double-blind, placebo-controlled design protocol. Mean F-waves amplitude, amplitude of the motor response evoked by magnetic stimulation (MEP), MEP duration, cortical silent period (CSP), central conduction time, and cortical threshold were evaluated. In Experiment B, 6 healthy controls received 400 mg of caffeine, the peripheral silent period (PSP) and CSP were evaluated. CSP was recorded bilaterally in biceps brachii (intensity 10% above threshold) and abductor digiti minimi (ADM) (intensity at 10% and 50% above threshold). Muscle contraction was above 50% of the maximum force in both experiments. Latencies were defined by a technician who was not aware of this investigation. Serum caffeine level was evaluated. Results. – In Experiment A, only the CSP, recorded in both ADM with intensity at 10% above threshold showed a significant change after caffeine (decrease of 17.1 ± 34.0 ms, about 12% reduction). In Experiment B, PSP did not change, but CSP tested with intensities 10% above threshold was significantly decreased by 20.8 ± 34.4 ms in ADM and 13.5 ± 13.8 ms in biceps (about 13 and 16%, respectively). Serum caffeine level clearly increased after consumption but no correlation could be found between these levels and CSP reduction. Conclusions. – In our investigation, caffeine elicited a consistent decrease of the CSP, suggesting that caffeine increases cortical neuronal excitability.

Climate change effects vary with region, season, and time of the day. Existing annual and diurnal temperature cycles will shift and be reshaped, leading to increased air temperatures earlier and later in the year. Buildings will be affected by these changes, especially the ones using passive design strategies, whose performance is highly weather dependent. Building energy simulation (BES) is key for building energy design and optimization. Since most buildings last 50+ years, BES must use future weather data accounting for climate change. Presently, photovoltaic (PV) energy self-consumption must be maximized through building demand flexibility and energy storage, because of grid and economic interests. However, clouds can shade PV systems, reducing production and increasing grid demand, particularly in the cooling season. This thesis addresses three complementary research topics that build on the use of high-resolution state-of-the-art historical and future climate data. First, two methods to produce future climate data for BES are compared. Secondly, upcoming changes in temperature, their interaction with solar radiation, and the consequent impacts on passive building strategies are analysed in the EU 43 most populated cities. Finally, cloud shading periods capable of triggering demand flexibility events are analysed and simulated. The results show that current methods used to produce future climate data for BES, produce reliable results when correctly applied. Upcoming climate change will impact diurnal temperature cycle by increasing or decreasing the daily temperature range depending on season and region. Further, natural ventilation and shading seasons will be affected, with a higher impact on energy consumption in Southern Europe. Finally, cloud shading periods vary with climate but, on average, clouds last 20 minutes and occur predominately in the afternoon. The simulation results show that grid energy demand can be reduced by 60 % while maintaining comfortable indoor conditions.

In the last decades there has been an expansion in the use of building mechanical cooling systems. This increase is due to several factors such as global warming, higher internal heat gains, widespread use of unshaded glazed façades and more stringent thermal comfort requirements. In mild to warm climates, buildings without operable windows require mechanical cooling during most of the year, even in moments when the outdoor conditions would allow for natural cooling by ventilation. To reverse this trend designers are encouraged to use natural cooling strategies such as natural ventilation (NV). A well-designed building NV system can reduce building energy use and contain the increasing demand for mechanical cooling systems in buildings. Unfortunately, building designers often struggle when trying to predict the performance of an NV system due, in part, to the lack of precision of the existing simple models for NV airflow in real-world conditions. This thesis investigates the wind driven NV airflow over a multitude of NV systems: night ventilation (NVC), single sided ventilation (SS1), pumping ventilation (SS2 and CR2), and corner ventilation (CR2). For these NV systems, this thesis developed simplified correlations that improve existing models for predicting these NV airflows. The results of this research show that NV systems can be modeled using simple correlations that can assist designers in the integration of these systems in modern buildings. The experimental study of NVC showed that this strategy can significantly reduce mechanical cooling load. The study of window effects on wind driven NV in SS1 systems showed that the window geometry can significantly increase the ventilation flow. Finally, the studies on pumping ventilation showed that this recently discovered ventilation mechanism is very prevalent in isolated buildings with SS rooms with two or more openings.

Quando, há cerca de dez anos, assisti à disciplina leccionada pelo Prof. Rui Nobre Moreira, “O que é uma teoria física?”, fiquei espantado com duas coisas. Primeiro, existia uma notável semelhança entre alguns aspectos do pensamento de Alfred North Whitehead, que eu na altura conhecia apenas superficialmente, e o trabalho desenvolvido na Universidade de Lisboa pelo grupo de investigação sobre os fundamentos da mecânica quântica coordenado pelo físico José Ramalho Croca. O segundo aspecto que me surpreendeu foi que nem o Prof. Moreira nem o Prof. Croca, nem os outros membros do grupo – que desde então passei a chamar de “Escola de Lisboa” - conheciam a obra de Whitehead, senão indirectamente. Como mostrei na minha dissertação de Mestrado, há uma sensível sintonia entre a visão da natureza proposta por Whitehead e a defendida pela Escola de Lisboa, mas não há influência directa. Como explicar tal comunhão de visões? É possível que exista tanta proximidade filosófica sem uma relação de filiação? E se não, quais os factores internos ao desenvolvimento científico que permitem articular estes dois episódios da aventura das ideias? A minha investigação foi guiada pela exigência de satisfazer aquele meu espanto seminal. A presente dissertação encerra os resultados que obtive no esforço de esclarecer esta ressonância ideal. Como qualquer outra investigação, pode-se entender quanto se apresenta a seguir como uma viagem, e, como tal, contendo uma ida e uma volta. Para enfrentar os celebérrimos problemas conceptuais inerentes aos fundamentos da física, seguiremos o percurso feito pelo próprio Whitehead. Enquadraremos o seu pensamento no seu contexto histórico, tanto científico como filosófico, visando ilustrar a sua posição em relação à crise nos fundamentos da matemática, antes, e nos fundamentos da física, a seguir. Ambas as crises colocaram em questão algum dos pressupostos filosóficos comummente aceites e apelaram para um renovado esforço conceptual. Não apenas muitas “verdades” foram rejeitadas, mas o próprio método científico teve que ser repensado. Whitehead viveu as duas crises na primeira pessoa e tentou elaborar uma síntese filosófica para lhes fazer face. Os aspectos do pensamento de Whitehead, que se podem genericamente definir como humanistas – os seus originais contributos à filosofia da educação, da religião e da civilização – estarão quase completamente excluídos da presente analise, que se limitará às componentes científicas da sua filosofia. Nomeadamente, ocupar-nos-emos do Whitehead físico-matemático. O valor científico e filosófico da sua obra tem sido em larga medida subestimado ou esquecido. Quer a comunidade dos matemáticos e dos físicos, quer a comunidade dos filósofos parece não ter ainda reconhecido o seu valor e a sua importância, embora, tanto na sua altura como hoje, o alto gabarito dos seus contributos lhe seja reconhecido. Neste sentido, tentaremos salientar a sua fertilidade nos actuais debates filosóficos em volta das mais problemáticas facetas dos fundamentos da física. A dissertação está dividida em três partes. Na primeira parte trataremos da situação problemática oriunda da matemática e mostraremos as lições epistemológicas que Whitehead soube extrair dela. A sua filosofia da matemática e os conceitos que orbitam em seu redor constituem um alicerce que nunca será removido por si por altura da posterior construção do seu sistema metafisico e cosmológico. A sua corrente de pensamento produziu um campo em expansão, mantendo uma intrínseca continuidade. Na segunda parte argumentaremos que Michael Faraday foi o fundador de um programa de investigação científica e subjacente programa metafísico, alternativo ao programa newtoniano. O programa inaugurado por Faraday é ainda o programa em desenvolvimento na física contemporânea. Whitehead foi um entusiasta continuador deste programa e a sua posição a respeito da física quântica (assim como a respeito da teoria da relatividade) deve-se entender neste quadro programático. Na terceira parte proporemos ao leitor uma experiência de pensamento: convidamo-lo a imaginar que Whitehead participou na famosa quinta conferência de Solvay, na qual os maiores físicos discutiram as novidades experimentais e teóricas mais espantosas da época. De facto, se a filosofia nasce do espanto, como foi dito por Aristóteles e repetido por Whitehead, os físicos também não puderam esquivar-se aos desafios lançados pelos fenómenos observados, recorrendo à especulação filosófica. Neste campo noético, enfrentaram-se posições divergentes quanto à interpretação da fenomenologia experimental. O maior problema conceptual que Whitehead se propôs resolver foi a separação e o sempre maior afastamento entre o conhecimento científico e o senso comum. Pois, de certa forma, já antes do surgir da mecânica quântica propriamente dita, Whitehead tinha sentido com irritação o cisma entre realistas e não realistas de que falara Karl Popper na sua obra A teoria dos quanta e o cisma na física. O objectivo da presente dissertação é, portanto, analisar a filosofia de Whitehead, assim como mostrar de que forma a mesma não pode ser colocada lado a lado com os intérpretes ortodoxos da mecânica quântica, tendo, pelo contrário, lugar entre os realistas.

Human-induced changes in the environment dramatically shape the distribution of many species by restricting their access to resources such as food or nest-sites. Ongoing biodiversity loss has prompted conservation projects and large-scale nest-site provisioning to halt species declines. While successful at recovering endangered populations, artificial nests may turn into ecological traps by attracting animals to sites that end up reducing their fitness, or into conservation traps by making populations fully reliant on continuous conservation actions. Particularly, these new artificial nesting landscapes may alter the structure and functioning of communities, and modify or promote new species interactions, with unknown consequences for the conservation of target species. In Europe, large-scale nest-site provisioning aimed at recovering lesser kestrel (Falco naumanni) populations attracted several other bird species forming mixed colonies. The main objective of this thesis was to investigate the consequences of these breeding assemblages for the conservation of the lesser kestrel and the European roller (Coracias garrulus) in Portugal. Using long-term monitoring data and a wide range of field techniques, this thesis first addresses the challenges and opportunities of artificial nests for the successful persistence of populations. Then, it investigates how costs and benefits typically associated with group living, such as increased transmission of parasites, competition for resources, and protection from predators, may affect the conservation of lesser kestrels and rollers. Overall, this thesis demonstrates that artificial nesting landscapes may cause target species to become fully reliant on conservation actions and could concentrate species with similar niches in supra-optimal breeding densities. Ectoparasite burden was influenced by the relative abundance of each host species, most species highly overlapped in their trophic niche, and rollers acquired clear anti-predatory benefits from nesting near lesser kestrels. Understanding the impacts of nest-provisioning beyond the recovery of target populations, by considering how they attract other species and shape the interactions between them and their resources, will help researchers and conservation managers to draw and adapt conservation actions that guarantee the long-term persistence of wildlife populations.

In this work, we catalog several scalar extensions of the Standard Model (SM) that provide suitable dark matter (DM) and/or novel charge-parity (CP)-violating interactions. We categorize these scalar extensions in terms of their phenomenology and study the impact of current and future experimental data on the models allowed parameter spaces. This thesis encompasses several works, developed during the course of this doctorate, that aim to providing unique signatures for the models and distinguish them experimentally, ultimately providing potential guidelines for the discovery of new physics.

The plan which gave purpose to this thesis was purposefully ambitious. Instead of focus-sing on a single theme, we chose to follow a path that would ultimately lead to a greater overall understanding of several ongoing processes within the atmospheres of planets in the Solar System. Our goal was to combine different techniques in a single project so that by the end of this PhD, not only did the candidate obtain valuable results and a worthy contribution to the scientific community, but also became proficient in multiple ways to study planetary atmospheres. With images from multiple spacecraft, we employed the Cloud-Tracking technique to study the winds on multiple layers of Venus’cloud deck, and at the tropospheric level of Jupiter’s atmosphere. We used the most modern instruments such as those on board the japanese Akatsuki mission, retrieving multiple wind profiles to study the variability and evolution of the atmosphere across several altitude layers. Along with capturing winds, we set out to gather the most complete survey of atmospheric gravity waves on the lower clouds of Venus. This effort will help not only to understand their role in powering su-perrotation but also provide general circulation models valuable data on this previously under-explored feature. From the ground we performed a unique Doppler velocimetry method to complement our analysis, proving that the wind results obtained from this method can be competitive with those gathered from spacecraft data at significantly lower costs and greater flexibility. The capabilities of the team in which I am inserted have enabled multiple collaborations on other projects, further reinforcing that science is a joint effort. In this document, I attempt to provide further proof that my contribution is not only to academia but the larger society as well.

A contaminação da água por contaminantes biológicos e poluentes orgânicos emergentes é um problema global que acarreta graves consequências socioeconómicas, ambientais e de saúde pública. Nesta tese apresentam-se duas metodologias inovadoras de controlo da bioincrustação, um fenómeno indesejável que ocorre em superfícies em contacto com a água e promotor de biocontaminação, e uma metodologia de remediação de poluentes orgânicos aquáticos, passível de promover sinergias para com a bio-descontaminação. Numa primeira metodologia antivegetativa não-lixiviante, revestimentos de diferentes bases poliméricas (polidimetilsiloxano e poliuretano) contendo o biocida Econea® enxertado, obtidos por um processo de imobilização previamente desenvolvido e patenteado, foram investigados para a proteção de superfícies metálicas e de filtros cerâmicos aplicados em diferentes sistemas em meio aquático. Esta metodologia revelou resultados antivegetativos promissores sob condições hidrodinâmicas de formação de biofilmes e quasi-estáticas simuladas, bem como de campo (condições reais), em particular para os revestimentos de base polidimetilsiloxano. Nestes revestimentos também se obtiveram reduções consideráveis na lixiviação do biocida para o meio aquático, compreendidas entre 34% a 100% (lixiviação indetetável), dependendo da matriz. Na segunda metodologia antivegetativa, desenvolveram-se espumas de poliuretano contendo Econea enxertado na sua estrutura celular com efeitos antivegetativos igualmente promissores, e similares aos obtidos pela metodologia de revestimentos não-lixiviantes, demonstrando a versatilidade da estratégia de imobilização de biocida, neste caso para estruturas poliméricas capazes de atuar como filtros bioativos por si só. Para a remedição de poluentes orgânicos, fotocatalisadores de TiO₂ anatase co-dopadas com cobalto e nitrogénio sintetizados revelaram atividades promissoras, com uma remoção de triclosan superior a 99%, em apenas 20 min sob irradiação de luz LED ultravioleta (365 nm) e visível (450 nm). A dopagem com cobalto revelou ainda poder potenciar efeitos antimicrobianos contra bactérias patogénicas, em particular para a Legionella pneumophila. Os fotocatalisadores demonstraram também compatibilidade para com revestimentos poliméricos inferindo a sua atividade fotocatalítica nos mesmos.

A questão central desta investigação pode ser assim enunciada: como pensar a mediação entre som e música, a passagem do sonoro ao musical, sem pressupor qualquer tipo de esquema transcendental — estruturas matemáticas ou formais, gramáticas ou qualquer tipo de código que delimite a priori as possibilidades da música? Como pensar um sentido musical que não esteja dado a priori numa regra de síntese qualquer? A problemática que investigamos tem reaparecido com alguma frequência na filosofia, ao menos desde a última crítica de Immanuel Kant, e sobretudo em pensadores do século XX como Theodor Adorno e Gilles Deleuze. Com efeito, há uma forte tradição musical — teórica e prática, de Pitágoras ao Programa — segundo a qual o sentido musical só é gerado quando, sobre os sons musicalmente desinformados, se sobrepõe algum tipo de esquema racional (i.e. razões, proporções, logoi). É, pois, no limite dessa abordagem — que hoje, na era da programação ubíqua, abunda — que surge o referido tema desta investigação. Podemos dizer que o problema em pauta nos é reimposto pelo próprio avanço dos esquemas matemáticos transcendentais em todas as áreas do pensamento, inclusive do pensamento musical. Mas não propomos, aqui, meramente re-ativar os autores que, antes da revolução digital, investigaram o que há para além dos programas ou esquemas musicais. Da nossa parte, introduzimos a seguinte hipótese: o conceito de diagrama, proposto por Charles S. Peirce como substituto pragmati(ci)sta, incorporado, sensível e nãoalgorítmico, do esquema transcendental kantiano, indica um caminho ainda não investigado, nomeadamente, o conceito de diagrama musical. Assim, para amplificar e dar corpo (musical) ao pensamento que há para além do programado e do programável, atentamos para a dinâmica mediadora dos diagramas visuais, gestuais e sobretudo sónicos, que a história da música (suas tecnologias e suas práticas) nos legou, e que chegam até este trabalho por intermédio de variadas escutas compostas, verbalizadas e anotadas por compositores, teóricos, escritores, artistas, músicos e filósofos.

We study the effects of disorder in epithelial confluent tissues through the Voronoi model for dense tissues. The modeling of epithelial tissues relies on three different mechanisms: cell-cell and cell-medium interactions, and propulsion or activity. First, we focus on the role of cell-cell interaction in this model by exploring, in the athermal limit, its anomalous jamming behavior. We introduce a new metric that allows us to find a hierarchical structure in its energy landscape similar to colloidal particle systems. We then introduce a cell-medium interaction by explicitly considering an interaction between the cells and their underlying substrate. We consider that the targeted geometry of the cells changes according to their spatial position and in turn affects the cells motility. We show that when the characteristic length scale of the disorder is smaller than the cell size, the cell motility increases when compared to its homogeneous counterpart. This result is in sharp contrast to what has been reported for tissues with heterogeneity in the mechanical properties of the individual cells, where the disorder favors rigidity. Due to the internal biological complexity of the cells, changes to the cell-substrate interaction should trigger a hierarchy of biochemical responses in the cell that lead to its adaptation to the new substrate region. As such, the process of cell adaptation to its underlying structure is not instantaneous but requires a finite time that in many cases competes with other relevant timescales for the dynamics such as, for example, the diffusion timescale. With this in mind, we then introduce a characteristic adaptation time of the cells to the cell-substrate interaction changes. We study how the competition between the adaptation of the cells and their mobility can compromise the fidelity of the substrate and by relating this with the previous disordered substrate propose a typical time scale for the adaptation of cells that is relevant for experiments. Lastly, we consider non-confluent tissues by allowing the cells to break from one another and create empty spaces. This change opens the door to the study of the surface properties of cell colonies and it is a first step towards the study of the transition from a single cell to confluent tissue. Implications of our findings in the field of Soft Condensed Matter Physics are discussed.

Aspects of gauge theories in two, three and five dimensions are investigated using matrix models. Specifically, we consider pure Yang–Mills theory and its deformations in two dimensions, and supersymmetric Yang–Mills and Chern–Simons-matter theories in three and five dimensions. The random matrix approach allows us to explore a vast range of features of the gauge theories, including phase transitions, one-form symmetries and integrability. Partition functions and Wilson loops are studied in these setups by exploiting their matrix model presentation derived by localization. Two main lines of research are pursued: the computation of exact results at fixed and the quest for quantum phase transitions at large . The partition functions of several three-dimensional quiver Chern–Simons-matter theories are computed exactly using Mordell integrals, and we put forward a character expansion in terms of Schur polynomials, with coefficients given by topological invariants. A correspondence between two matrix models is provided as well, one computing topological invariants in pure Chern–Simons theory and the other arising from a two-dimensional, noncommutative scalar field theory. The correspondence is extended to supermatrix models, with ABJ(M) theory replacing topological Chern–Simons theory in this case. Partition functions and Wilson loop expectation values in three-dimensional = 4 gauge theories are also computed, uncovering a relation with Calogero–Moser integrable systems. Furthermore, we apply localization to five-dimensional supersymmetric Yang–Mills theory on compact product manifolds 3 × Σ, where Σ is a closed oriented Riemann surface, and introduce in this way a novel, “squashed” deformation of q-deformed Yang–Mills theory on Σ. Proceeding in the study of deformations of two-dimensional Yang–Mills theory, we analyze their perturbation by the operator ⊤₸ and prove that Abelianization still holds, although other characteristic properties such as factorization of the partition function break down. The analysis of large quantum phase transitions in matrix models and gauge theories constitutes the core of the thesis. We present a systematic study and classification of phase transitions for supersymmetric gauge theories on three- and five-dimensional spheres of large radius. The transitions are always third order for gauge theories connected to a known superconformal point, but are second order for generic five-dimensional () theories. Several multi-parameter families of unitary matrix models are also considered and their phase diagrams are established. Finally, we show how the Douglas–Kazakov transition of two-dimensional Yang–Mills on the sphere extends to its newly derived deformations. When both ⊤₸ and q-deformations are turned on, the two effects compete, and the system has two phases in the most part of the parameter space, but the weak coupling phase is removed in the regime of strong ⊤₸ -deformation, whereas the strong coupling phase is removed in the strong q-deformation regime.

No summary/description provided

The isolation process of Island parasite populations has revealed a remarkable set of changes in their characteristics, termed parasite island syndromes. Improving knowledge of the effect of insularity on parasite communities from hosts with different time scales of isolation, is essential for understanding the processes involved in the evolution of parasitism and how the period of host isolation, manifests itself on parasite island syndromes. This thesis addresses the ectoparasite communities of Turdus merula, Sylvia atricapilla, Fringilla coelebs and Erithacus rubecula, from mainland Portugal and three Islands of the Azores Archipelago, specifically São Miguel, Terceira and Flores. The Azores Archipelago, geographically positioned as the Northernmost Archipelago of Macaronesia and composed of nine Oceanic Islands recognized as biodiversity hotspots, make it an important area to study the patterns of insular evolution. Live birds were captured with mist nets and sampled for presence of ectoparasites using the modified fumigation chamber method. Traditional methods were used for microscopic identification of hippoboscid flies, fleas and chewing lice. Insular ectoparasite communities of host species were compared with continental communities based on parasite island syndromes (species richness, prevalence and host specificity). Additionally, insular species richness was compared between the area of the Islands and their distance from the mainland. The present study showed that ectoparasites do not failed to establish to the Azores Islands, and furthermore, the diversity of the ectoparasites communities, especially to chewing lice, was clearly enriched on the Azores Islands, with more 3 species than mainland birds. The results also revealed a high insular prevalence of ectoparasites. In regards to host specificity, insular ectoparasites have retained the characteristic specificity of the mainland. Even though island syndromes were not correlated with Island area and distance from the mainland, the overall findings indicate that characteristics associated with the Islands, specifically ambient humidity, the parasites, mainly ability to tolerate ambient humidity, and the hosts, particularly population densities, body size, and nest sanitation, influence the structuring of insular ectoparasite assemblages. Parasite island syndromes were especially notable in T. merula, a bird with two colonization events on the Azores Islands, which suggest that the host isolation on Islands may influence the evolution of insular parasite communities.

Tsunami disasters pose a significant threat to coastal communities. In the last decades, tsunamis caused enormous destruction and exceeding 250000 fatalities. International efforts led to sig-nificant advances in tsunami science and research, but recent events demonstrated some limi-tations. Thus, it is essential to increase our knowledge of the source to coast tsunami phenom-enon. A better understanding of potential tectonic structures and other generation mechanisms is needed, especially in complex geologic domains or where sources are unknown. Furthermore, we need to improve Tsunami Warning Systems (TWSs) to provide timely alerts for communi-ties in the near field. Therefore, potential tsunamigenic sources in the diffuse plate boundary setting and the near field of the southwest Iberian margin (SWIM) are investigated. For the March 31, 1761, trans-atlantic tsunami, numerical modelling has been used to propose a structure that agrees with tsunami travel times, tsunami observations, macroseismic data, and kinematic plate modelling. Since there exists a description of a tsunami for the November 11, 1858, Sétubal earthquake, its source has been investigated using macroseismic analysis. The analysis suggests a local structure in a compressive regime with weak to moderate tsunamigenic potential. Future tsu-nami hazard assessments need to include the sources of the investigated events. To quickly estimate the tsunami impact, the Tsunami Runup Predictor (TRP), an empirical source-to-coast method to instantly provide first-order estimates of the tsunami runup based on waveform parameters has been developed. The TRP is helpful for emergency managers and evacuation planning for near-field events. Moreover, the author of this thesis contributed to the tsunami impact assessment of September 28, 2018, Palu tsunami, where tsunamis generated by multiple sources caused runup heights up to 9.2 m. However, for local sources, tsunami warning remains challenging; thus, communities need to be prepared how to respond appropriately to earthquakes and tsunamis with or without warning.

This research wants to explore the diversity of (trans)local transformative initiatives and how they can synergistically generate broad societal change towards sustainability and democracy. I want to seize doable alternatives to deal with existing institutional barriers and social impasses and explore possible approaches and instruments for ‘governing’ transition. I want to address the research gap related to sensible ways of governing the later phase of transitions in a context of rapid and profound change. The research question is therefore: “What would be an applicable and comprehensive governance instrument to support the development of (trans)local transitions, facing the challenge of tipping point times?”. I adopted transdisciplinary participatory action research and focused on developing spaces where renewal can be nurtured in the context of reorganization (in the resilience sense). This approach is expected to lead to new agreements and actions. Still, it is primarily designed to facilitate multi-stakeholder learning processes and open the floor for the emergence of new shared meanings. I assumed that the complexity of the sustainability challenge demands for collaboration between different actors, namely local governments and community-led initiatives. Existing research revealed that many tensions and obstacles to partnership still persist, and results are far from meaningful, while providing insights on how to overcome these challenges. I summarized the state of the art in a Compass for Transformative Collaborations. The research process was based in two projects nested in the Transition movement, namely the Municipalities in Transition and the Dive Deep & Dream Big. The Transition movement is one of the most significant examples of local communities leading the way to a post‐carbon society. The movement is spread world‐wide and demonstrates a distinctive openness for collaborations, providing therefore, an experimental space with transformational ambition. Both these action research projects were supported by the University of Lisbon, anchored by its role within ECOLISE (European Network for Community‐Led Initiatives on Climate Change and Sustainability), with the broad participation of other organizations. I played the role of an embedded researcher, fully partaking as an observer and participant, contributing actively and reflectively to the codesign and facilitation. The Municipalities in Transition project started in 2017 and aimed at exploring how municipalities and civil society could work better together. The research included codesigning a systemic and operational instrument that could boost the transformative reach of cooperation between local actors of sustainability and testing in six pilots in five countries. Local actors can use this instrument together to capture the governance imprint of transformational efforts and are challenged to reorganize and expand it, improving the stock of change actions and related experiences. Quite drastic changes occurred in all the six communities that tested the governance instrument. These changes were the product of the reflexive experimentation, the new social relations, the empowerment process, the changing tensions, the translocal connectivity, the discourse formation, the new (or reinforced) institutional homes and the strategic actions. New ways of doing, organising, framing and/or knowing, as expressed in the theory of Transformative Social Innovation, used as analytical framework. The Dive Deep & Dream Big project started in 2019 and was set as a collaborative inquiry to support break-through change at the municipal scale. Individuals and organizations working in different contexts got together to share knowledge and develop new transition pathways. Creating a social learning environment gave visibility to barriers that prevented effective action by fractally reproducing patterns of polarization. There was an agreement on the building blocks of a new integral governance framework based on reconciliation and imagination. These two action research projects provided complementary information, opening the floor to a holistic approach to transition. As an answer to my research question, I present a structured and replicable transformative governance approach that involves connecting the support of change makers, the welcoming of trauma, and the exercise of creativity, together with the acceleration of systemic collaboration. It can be used as a heuristic in the design of (trans)local regenerative interventions, able to catalyse and support ambitious and inclusive systemic change at the local scale and act as a leverage point for wider societal transformation.

Microalgae and seaweeds, a natural source of highly valuable bioactive compounds, are considered one of the most promising and innovative sources of novel functional foods that can favourably affect human health. This study focused on the bioprospection of bioactive compounds from freeze-dried biomasses and extracts of selected microalgae (Chlorella vulgaris, Arthrospira platensis, Isochrysis galbana, Tetraselmis IMP3, Tetraselmis CTP4, Skeletonema sp.) and seaweeds (Petalonia binghamiae, Halopteris scoparia, Osmundea pinnatifida, Gelidium sesquipedale, Pterocladiella capillacea) species. The benefits associated with the utilization of these as nutraceuticals or functional ingredients were assessed taking into consideration the nutritional composition, biological activities (antioxidant, anticancer, anti-inflammatory, hypocholesterolemic), and bioaccessibility of target compounds. The bioprospection studied revealed that the microalga I. galbana exhibited the highest phenolic content in both aqueous and ethanolic extracts. The aqueous extracts of the microalgae Skeletonema sp., I. galbana and A. platensis and of the seaweeds P. binghamiae and H. scoparia displayed a strong antioxidant activity (above 90% inhibition). The microalga Skeletonema sp. and seaweeds H. scoparia and P. capillacea ethanolic extracts exhibited high anti-inflammatory potential (above 70% of COX-2 inhibition). Freeze-dried biomass and ethanolic extract of the I. galbana showed to be highly cytotoxic against HeLa human cervical cancer cells, inducing a cell line viability decrease upper 99%, demonstrating anticancer potential. This microalga aqueous extract also presented hypocholesterolemic capacity, inducing a significant decrease of cholesterol absorption through Caco-2 monolayers. I. galbana was also the richest in ω3 long chain polyunsaturated fatty acids (ω3 LC-PUFAs), with high contents of α-linolenic, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Based on I. galbana potential, it was chosen to formulate a high-value functional food by the incorporation of 2% (w/w) of freeze-dried biomass and ethyl acetate lipid extract, as value-added food ingredients in the yogurts’ preparation, in order to increase and improve the bioaccessibility of lipids. When comparing to the original yogurt, the obtained results showed an increasing of ω3 LC-PUFAs level, specially of DHA, and ω3/ω6 ratio reached a more desirable level. The bioaccessibility study using in vitro digestion model showed a poor bioaccessibility of ω3 LC-PUFAs. The obtained results pave the way for future application of these algae species for pharmaceutical, nutraceutical and food industries.

Esta dissertação tem como objetivo principal o estudo de modelos de crescimento populacional. Neste contexto foi realizado um levantamento dos modelos de crescimento populacional existentes, a partir de pesquisa bibliográfica. Deste levantamento, resultou a seleção de quatro modelos clássicos de crescimento populacional: Malthus, Verhulst, Gompertz e Montroll. Posteriormente os modelos cuja aplicação tinha viabilidade utilizando-se os dados disponíveis relativos a São Tomé e Príncipe, foram aplicados e os resultados comparados. Os dados disponíveis, relativos à população residente em São Tomé e Príncipe, foram obtidos a partir do site do Instituto Nacional de Estatística (INE) de São Tomé e Príncipe.

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 importantes para a prática clínica, com base na melhor evidência científica disponível. 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).

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 importantes para a prática clínica, com base na melhor evidência científica disponível. 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).