Sexual reproduction vs. clonal propagation in the recovery of a seagrass meadow after an extreme weather event

Marine flowering plants can reproduce sexually and clonally, and the relative contribution of these two modes can be dependent on the environmental conditions. Zostera marina, a seagrass widely distributed in the northern hemisphere, can form annual and perennial meadows with different proportions of sexual versus clonal propagation depending on the environmental disturbance regime. We study the hypothesis that the contribution of sexual propagation varies during the recovery of a seagrass meadow. In this case study, we compare the proportion of sexual versus clonal propagation of a perennial Z. marina meadow before its disappearance due to winter storms and after recovery. Before disturbance, genotypic diversity was high, indicating frequent sexual reproduction events likely to create an abundant seed bank. Seedling germination allowed the population to recover after the extreme disturbance. As months passed, seedlings became rare and finally absent, giving place to adult shoots. In an advanced stage of colonization, the shoots colonized the area by vegetative growth, which lowered the genotypic diversity. Despite this reduction over time, the genotypic diversity of the new meadow is still high, demonstrating the importance of sexual reproduction in meadow recovery and persistence.info:eu-repo/semantics/publishedVersio

Exergy Analysis of a Turbofan Engine

In this thesis, exergetic methodology is applied to a high bypass turbofan engine at cruise flight phase. Exergy analysis is a powerful tool, which has been used in the design, operation, and performance of energy systems by many engineers and researchers. Among its advantages, it is primary used since it allows the determination of the locations, types, and true magnitudes of wastes and destruction of exergy. The engine selected for this analysis, is the CFM56-5A1 turbofan engine. It has two spools and the components that are exergetically evaluated are the fan, low pressure compressor, high pressure compressor, combustion chamber, high pressure turbine and low pressure turbine. In order to perform an exergy analysis, the modelling of the engine has to be performed first, for the cruise mission. It is modelled by using a genuine code in the software Matlab R2015A and was verified and validated by using the software Gasturb 13. Next, the exergy analysis is performed according to the thermodynamic laws. The exergy analysis is carried out by conducting mass, energy and exergy balance of each component of the engine. The figures of merit used to evaluate the engine are as follows: exergy efficiency, improvement potential, relative exergy destruction, fuel depletion rate and productivity lack. The most irreversible component of the engine is found to be the combustion chamber with 9.31 MW. The exergetic efficiencies of the fan, LPC, HPC, CC, HPT and LPT are 92.13%, 95.91%, 97.52%, 76.71%, 90.74%, 90.32%, respectively.Nesta tese, é realizado um estudo exergético, aplicado a um motor turbofan de alta razão de bypass, para as condições de voo de cruzeiro. A análise exergética é considerada uma “ferramenta” extremamente importante, utilizada no design, operação e performance de sistemas energéticos. Entre todas as suas vantagens, é principalmente utilizada para determinar e calcular as localizações, tipos e magnitudes das perdas e destruições de exergia num sistema energético. O motor escolhido para a análise exergética, foi o motor turbofan CFM56-5A1. Este motor é constituído por dois eixos, sendo que os componentes que foram submetidos à análise são respetivamente o fan, compressor de baixa pressão, compressor de alta pressão, câmara de combustão, turbina de alta pressão e turbina de baixa pressão. De forma a realizar a análise exergética, foi necessário primeiro criar um modelo matemático do motor, com o fim de gerar os dados de performance do motor para as condições de cruzeiro. A modelação foi feita com recurso a um código criado no software Matlab R2015A. Adicionalmente foi utilizado o software Gasturb 13, como método de comparação e validação dos dados gerados do código em Matlab. Na análise exergética, os componentes do motor foram definidos com recurso a equações de balanço de massa, energia e exergia. As figuras de mérito utilizadas para avaliar exergeticamente o motor, foram respectivamente a eficiência exergética, potencial de melhoramento, destruição de exergia relativa, “fuel depletion ratio” e “productivity lack”. Após realizada a análise exergética, o componente determinado como o mais irreversível foi a câmara de combustão, com uma destruição de exergia de 9.31 MW. As eficiências exergéticas do fan, LPC, HPC, CC, HPT, LPT, são respetivamente 92.13%, 95.91%, 97.52%, 76.71%, 90.74%, 90.32%

Information profiles for DNA pattern discovery

Finite-context modeling is a powerful tool for compressing and hence for representing DNA sequences. We describe an algorithm to detect genomic regularities, within a blind discovery strategy. The algorithm uses information profiles built using suitable combinations of finite-context models. We used the genome of the fission yeast Schizosaccharomyces pombe strain 972 h- for illustration, unveilling locations of low information content, which are usually associated with DNA regions of potential biological interest.Comment: Full version of DCC 2014 paper "Information profiles for DNA pattern discovery

First description of seagrass distribution and abundance in Sao Tome and Principe

Seagrass meadows in Sao Tome and Principe, eastern Atlantic Ocean, are described here for the first time. Specifically, we quantified the biomass and density of seagrasses, characterized the plant morphology and measure their nutrient content as a proxy of the nutrient environmental conditions where the meadows develop. The seagrass Halodule wrightii was found in two locations of the northeastern coast of the island of Sao Tome: 1) developing throughout an estimated area of 1500 ha surrounding Cabras islet, at a depth range of 4-10 m, on sandy bottom; and 2) at Santana bay with an area of 1500 m(2) at 5-10 m depth, on sandy bottom. A highly morphologically different population of Halodule wrightii was found on the northeastern coast of the island of Principe, off Abade beach, covering an area of 135 m2 at 4 m depth. Further research is needed to assess if this is a different species. Shoot biomass and density was 10 and 4-fold higher in Sao Tome than in Principe, respectively. CN ratios of above and belowground tissues of plants collected in Sao Tome were also significantly higher than in Principe. The carbon content of Halodule leaves from Sao Tome and Principe (41%) was much higher than that reported for other Halodule species, suggesting that meadows may have an important ecological role for carbon fixation. The presence of H. wrightii in Sao Tome and Principe raises ecological and evolutionary questions that warrant further research.PADI Foundation [21670

Field studies of seahorse population density, structure and habitat use in a semi-closed north-eastern Mediterranean marine area (Stratoni, north Aegean Sea)

The present study was carried out in the marine area of Stratoni, Greece, where two seahorse species are present (Hippocampus hippocampus and H. guttulatus). Two surveys were conducted (September 2016, May 2019) to gather information regarding seahorse species’ abundance, distribution and habitat characteristics. Four different seahorse natural and artificial habitat types were identified. Results revealed that the abundance of H. hippocampus was relatively high, especially at sites with artificial structures, while the presence of H. guttulatus was rare. Data collected can provide baseline information for future population assessments.Project Seahorse. This work was supported by Hellas Gold (https://www.hellas-gold.com/). FCT - Foundation for Science and Technology through project UIDB/04326/2020, and from the operational programmes CRESC Algarve 2020 and COMPETE 2020 through project EMBRC.PT ALG-01-0145-FEDER-022121info:eu-repo/semantics/acceptedVersio

Integrating 3D Objects and Pose Estimation for Multimodal Video Annotations

With the recent technological advancements, using video has become a focal point on many ubiquitous activities, from presenting ideas to our peers to studying specific events or even simply storing relevant video clips. As a result, taking or making notes can become an invaluable tool in this process by helping us to retain knowledge, document information, or simply reason about recorded contents. This thesis introduces new features for a pre-existing Web-Based multimodal anno- tation tool, namely the integration of 3D components in the current system and pose estimation algorithms aimed at the moving elements in the multimedia content. There- fore, the 3D developments will allow the user to experience a more immersive interaction with the tool by being able to visualize 3D objects either in a neutral or 360º background to then use them as traditional annotations. Afterwards, mechanisms for successfully integrating these 3D models on the currently loaded video will be explored, along with a detailed overview of the use of keypoints (pose estimation) to highlight details in this same setting. The goal of this thesis will thus be the development and evaluation of these features seeking the construction of a virtual environment in which a user can successfully work on a video by combining different types of annotations.Ao longo dos anos, a utilização de video tornou-se um aspecto fundamental em várias das atividades realizadas no quotidiano como seja em demonstrações e apresentações profissionais, para a análise minuciosa de detalhes visuais ou até simplesmente para preservar videos considerados relevantes. Deste modo, o uso de anotações no decorrer destes processos e semelhantes, constitui um fator de elevada importância ao melhorar potencialmente a nossa compreensão relativa aos conteúdos em causa e também a ajudar a reter características importantes ou a documentar informação pertinente. Efetivamente, nesta tese pretende-se introduzir novas funcionalidades para uma fer- ramenta de anotação multimodal, nomeadamente, a integração de componentes 3D no sistema atual e algorítmos de Pose Estimation com vista à deteção de elementos em mo- vimento em video. Assim, com estas features procura-se proporcionar um experiência mais imersiva ao utilizador ao permitir, por exemplo, a visualização preliminar de objec- tos num plano tridimensional em fundos neutros ou até 360º antes de os utilizar como elementos de anotação tradicionais. Com efeito, serão explorados mecanismos para a integração eficiente destes modelos 3D em video juntamente com o uso de keypoints (pose estimation) permitindo acentuar pormenores neste ambiente de visualização. O objetivo desta tese será, assim, o desenvol- vimento e avaliação continuada destas funcionalidades de modo a potenciar o seu uso em ambientes virtuais em simultaneo com as diferentes tipos de anotações já existentes

Bathymetric surveys from SAR satellite images using wavelets

When waves propagate in coastal areas they sufer changes in the wavelength and wave direction resulting from the interaction with the sea bottom. In SAR images, the waves can be identify through variations in the gray tones of the image, making it possible to infer the bathymetry from the variations in the wavelength. Commonly, the fast Fourier transform (FFT) is used to estimate the wavelength in domains close to the coast, recognizing, however, that this method has some limitations, mainly for small depths. To overcome the limitations of FFT, this work uses wavelet spectral analysis to estimate bathymetric data. The new image processing methodology shows positive and promising results for mapping shallow marine environments.Peer Reviewe

Lean and quality management integration: improvement program implementation in a service company

Lean Thinking is an important pillar in the success of any program of continuous improvement process. Its tools are useful means in the analysis, control and organization of important data for correct decision making in organizations. This project had as main objective the design of a program of quality improvement in Eurico Ferreira, S.A., based on the evaluation of customer satisfaction and the implementation of 5S. Subsequently, we have selected which business area of the company to address. After the selection, there was an initial diagnostic procedure, identifying the various points of improvement to which some tools of Lean Thinking have been applied, in particular Value Stream Mapping and 5S methodology. With the first, we were able to map the current state of the process in which all stakeholders were represented as well as the flow of materials and information throughout the process. The 5S methodology allowed to act on the wastage, identifying and implementing various process improvements