Modelação 3D de teores de depósitos minerais condicionados por tipos de mineralização. O caso de estudo do depósito mineral do Zambujal, Minas de Neves-Corvo

Dissertação para obtenção do Grau de Mestre em Engenharia Geológica (Georrecursos)

Cape Verde’s foreign policy: an economic perspective

The virtuous cycle between development success and foreign policy in Cape Verde reflects a positive interaction between globalization and governance. Development success under globalization entails positive market perceptions regarding the orientation and predictability of policies as well as the accompanying institutional arrangements, thereby making foreign policy salient beyond the comparator group, or “aspirational”. Even if there is no universally applicable development model, an aspirational foreign policy can be built on positive rankings with respect to comparator groups. In Macedo and Pereira (2010), macrolevel policy and institutional combinations underpinning trade diversification and income convergence in West and Southern Africa are used to establish development success for Cape Verde and Mozambique respectively. Here, the narrative of long-term development helps identify the following drivers: moving towards a market economy; opening up to regional and global trade; increasing economic and political freedom; pursuing macroeconomic stability and financial reputation; ensuring policy continuity (especially in trade and industrial sectors) and focusing on human development (especially poverty reduction and education). Looking at GDP per capita and indicators of financial reputation and good governance of sub-regional peers is not sufficient to conclude that Cape Verde’s convergence will be sustained. Nevertheless, the positive interaction between trade and financial globalization, on the one hand, and democracy and good governance, on the other, have positive implications for the effectiveness of foreign policy across the region as well as in the Portuguese-speaking community.

The ethical dilemma of expatriates in emerging economies: A liminal perspective

Adjustment to emerging economies is benefited if Western expatriates recognise they are experiencing a liminal situation, which can lead to the instrumental utilisation of coping strategies as equivalent to rites of passage between distinct ethical frameworks. Given the characteristics ascribed to rites, the ethical dilemma resulting from the simultaneous demand to abide by local rules and to respect Western ethical principles is more easily solved. Consequently, effective and sustainable adjustment is favoured. Implications for organisations and individuals are discussed.

Non–profit and investment attractiveness – best practices under a national perspective

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Estruturas 3D porosas com gradiente de funcionalidade produzidas por Freeze-casting

Dissertação para obtenção do Grau de Mestre em Engenharia de Materiais

A Constructivist perspective on EU'S democracy promotion in Turkey

The European Union, as a regional actor and an example of stability and well-being, has embraced a set of principles it has stood for and which constitute its own identity. The diffusion of these values among third countries is one of the objectives of EU’s External Policy. Democracy can be found among the principles that are sought to be exported through comprehensive and complex strategies within different frameworks, such as neighbourhood relations, trade partnerships and the accession process. Focusing on the latter, candidates are object of an intensive process of Europeanisation that operates through different mechanisms like socialisation and conditionality. Turkey, on the other side, has decided to apply for full membership several decades ago and, ever since, it has been pressured to Europeanise, which includes improving its unstable democracy. This case, however, is different from all other previous enlargements; for its special socio-cultural and civilisational features, Turkey constitutes a more complex novelty for the European Union. Therefore, this thesis aims to study the influence of the European Union on the democratisation process of Turkey, focusing on the period ranging between 1999, the year the European Council recognised Turkey’s candidacy status, and 2009 that marks the 10-year period of that condition. It is the intention of this project to assess the impact of the European Union at that level through the study of the democratic evolution of the country and its co-relation with other variables related to the presence or pressure of the EU. As this is a challenging objective, it will require a deep reflection upon central concepts like democracy and democratic consolidation, and a diversified use of methodological techniques, such as statistical analysis and mathematical co-relations, historical analysis, literature review and in-depth interviews. This study will privilege a Constructivist approach, emphasising the social construction of reality and the role of the ideational aspects – identity, perceptions and the broader socio-cultural dimension – in Turkey-EU relations.

Amorphous silicon e 3D sensors applied to object detection

Nowadays, existing 3D scanning cameras and microscopes in the market use digital or discrete sensors, such as CCDs or CMOS for object detection applications. However, these combined systems are not fast enough for some application scenarios since they require large data processing resources and can be cumbersome. Thereby, there is a clear interest in exploring the possibilities and performances of analogue sensors such as arrays of position sensitive detectors with the final goal of integrating them in 3D scanning cameras or microscopes for object detection purposes. The work performed in this thesis deals with the implementation of prototype systems in order to explore the application of object detection using amorphous silicon position sensors of 32 and 128 lines which were produced in the clean room at CENIMAT-CEMOP. During the first phase of this work, the fabrication and the study of the static and dynamic specifications of the sensors as well as their conditioning in relation to the existing scientific and technological knowledge became a starting point. Subsequently, relevant data acquisition and suitable signal processing electronics were assembled. Various prototypes were developed for the 32 and 128 array PSD sensors. Appropriate optical solutions were integrated to work together with the constructed prototypes, allowing the required experiments to be carried out and allowing the achievement of the results presented in this thesis. All control, data acquisition and 3D rendering platform software was implemented for the existing systems. All these components were combined together to form several integrated systems for the 32 and 128 line PSD 3D sensors. The performance of the 32 PSD array sensor and system was evaluated for machine vision applications such as for example 3D object rendering as well as for microscopy applications such as for example micro object movement detection. Trials were also performed involving the 128 array PSD sensor systems. Sensor channel non-linearities of approximately 4 to 7% were obtained. Overall results obtained show the possibility of using a linear array of 32/128 1D line sensors based on the amorphous silicon technology to render 3D profiles of objects. The system and setup presented allows 3D rendering at high speeds and at high frame rates. The minimum detail or gap that can be detected by the sensor system is approximately 350 μm when using this current setup. It is also possible to render an object in 3D within a scanning angle range of 15º to 85º and identify its real height as a function of the scanning angle and the image displacement distance on the sensor. Simple and not so simple objects, such as a rubber and a plastic fork, can be rendered in 3D properly and accurately also at high resolution, using this sensor and system platform. The nip structure sensor system can detect primary and even derived colors of objects by a proper adjustment of the integration time of the system and by combining white, red, green and blue (RGB) light sources. A mean colorimetric error of 25.7 was obtained. It is also possible to detect the movement of micrometer objects using the 32 PSD sensor system. This kind of setup offers the possibility to detect if a micro object is moving, what are its dimensions and what is its position in two dimensions, even at high speeds. Results show a non-linearity of about 3% and a spatial resolution of < 2µm.

Writing/erasing 3D micro and nano wrinkles in flexible elastomers for volatile organic compounds sensor

Micro/nano wrinkled patterns on cross-linked urethane/urea polymeric flexible free standing films with two soft segments, polypropylene oxide and polybutadiene, can be induced by UV-irradiation. The ability to write/erase these 3D structures, in a controlled manner, is the main focus of this work. The imprinting of the wrinkled structures was accomplished by swelling in an appropriate solvent followed by drying the membranes after the cross-linking process and UV irradiation. The surface tailoring of the elastomeric membranes was imaged by optical microscopy, scanning electronic microscopy and by atomic force microscopy. To erase the wrinkled structures the elastomers were swollen. The swelling as well as the sol/gel fraction and the UV radiation were tuned in order to control the wrinkles characteristics. It was found that the wrinkles wavelength, in the order of microns (1±0,25μm), was stamped by the UV radiation intensity and exposure time while the wrinkles' amplitude, in the order of nanometers (150-450 nm), was highly dependent on the swelling and sol/gel fraction. A prototype for volatile organic compounds detection was developed taking advantage of the unique 3D micro/nano wrinkles features.

Complex networks and data mining: toward a new perspective for the understanding of complex systems

Complex systems, i.e. systems composed of a large set of elements interacting in a non-linear way, are constantly found all around us. In the last decades, different approaches have been proposed toward their understanding, one of the most interesting being the Complex Network perspective. This legacy of the 18th century mathematical concepts proposed by Leonhard Euler is still current, and more and more relevant in real-world problems. In recent years, it has been demonstrated that network-based representations can yield relevant knowledge about complex systems. In spite of that, several problems have been detected, mainly related to the degree of subjectivity involved in the creation and evaluation of such network structures. In this Thesis, we propose addressing these problems by means of different data mining techniques, thus obtaining a novel hybrid approximation intermingling complex networks and data mining. Results indicate that such techniques can be effectively used to i) enable the creation of novel network representations, ii) reduce the dimensionality of analyzed systems by pre-selecting the most important elements, iii) describe complex networks, and iv) assist in the analysis of different network topologies. The soundness of such approach is validated through different validation cases drawn from actual biomedical problems, e.g. the diagnosis of cancer from tissue analysis, or the study of the dynamics of the brain under different neurological disorders.

Resilience in organizations: The perspective of managers in Portugal and Germany

The concept of organizational resilience has become popular in Organizational Studies during the last decades - yet researchers have not been able to find one commonly accepted definition for what exactly it is. What are the drivers of resilience in organizations? Are there certain cultural factors and national differences regarding the perception of the concept? This paper aims to answer these questions from a perspective of within institutions. A group of managers from different corporations in Portugal and Germany has been interviewed in order to understand how managers experience and characterize organizational resilience. Based on qualitative inductive research the results show that organizational resilience is built on four main drivers: a sense of proximity, a sense of openness, a sense of challenge and a sense for structure.

Produção de matrizes porosas 3D baseadas em réplicas invertidas de cristais coloidais

A Engenharia de Tecidos surge da necessidade recorrente de regenerar ou recriar órgãos e tecidos danificados devido a vários tipos de trauma. A carência de funcionalidades resultante pode ser resolvida através da implantação de substitutos bio-sintéticos. O presente trabalho consiste na produção de matrizes porosas 3D baseadas em réplicas invertidas de cristais coloidais com futura aplicação em substituintes ósseos sintéticos para fraturas de não-união. O substituinte ósseo consiste numa estrutura denominada Inverse colloidal crystal (ICC), em que a sua organização singular resulta numa homogénea proliferação celular e num aumento das propriedades mecânicas, quando comparada com outros substituintes. O primeiro passo para a obtenção desta estrutura é a produção de microesferas de poliestireno, por uma técnica baseada em microfluídica. Posteriormente as microesferas são empacotadas resultando numa estrutura coesa com ligações entre microesferas vizinhas. O preenchimento dos espaços vazios entre microesferas pelo biomaterial pretendido e posterior remoção das microesferas dá origem à estrutura porosa do ICC. ICCs poliméricos (ϕCs = 1,00) e compósitos (ϕCs = 0,86 e ϕHA = 0,14; ϕCs = 0,67 e ϕHA = 0,33; ϕCs = ϕHA = 0,50) são produzidos e as suas propriedades mecânicas são testadas através de ensaios de compressão e comparadas com outros substituintes sintéticos. Para avaliação do comportamento dos materiais em contacto com meio biológico, foram realizados testes de citotoxicidade que revelaram uma viabilidade celular acima dos 80% em todos os ICCs.

Development of 3D in vitro models for prediction of hepatic metabolism and toxicity

The development of human cell models that recapitulate hepatic functionality allows the study of metabolic pathways involved in toxicity and disease. The increased biological relevance, cost-effectiveness and high-throughput of cell models can contribute to increase the efficiency of drug development in the pharmaceutical industry. Recapitulation of liver functionality in vitro requires the development of advanced culture strategies to mimic in vivo complexity, such as 3D culture, co-cultures or biomaterials. However, complex 3D models are typically associated with poor robustness, limited scalability and compatibility with screening methods. In this work, several strategies were used to develop highly functional and reproducible spheroid-based in vitro models of human hepatocytes and HepaRG cells using stirred culture systems. In chapter 2, the isolation of human hepatocytes from resected liver tissue was implemented and a liver tissue perfusion method was optimized towards the improvement of hepatocyte isolation and aggregation efficiency, resulting in an isolation protocol compatible with 3D culture. In chapter 3, human hepatocytes were co-cultivated with mesenchymal stem cells (MSC) and the phenotype of both cell types was characterized, showing that MSC acquire a supportive stromal function and hepatocytes retain differentiated hepatic functions, stability of drug metabolism enzymes and higher viability in co-cultures. In chapter 4, a 3D alginate microencapsulation strategy for the differentiation of HepaRG cells was evaluated and compared with the standard 2D DMSO-dependent differentiation, yielding higher differentiation efficiency, comparable levels of drug metabolism activity and significantly improved biosynthetic activity. The work developed in this thesis provides novel strategies for 3D culture of human hepatic cell models, which are reproducible, scalable and compatible with screening platforms. The phenotypic and functional characterization of the in vitro systems performed contributes to the state of the art of human hepatic cell models and can be applied to the improvement of pre-clinical drug development efficiency of the process, model disease and ultimately, development of cell-based therapeutic strategies for liver failure.

Leprosy and pregnancy in the State of Para: an epidemiological perspective

Introduction A few older publications describe leprosy associated with pregnancy, a situation that has been linked to leprosy exacerbation. This study aimed to describe the detection rate of this association in the State of Pará by county and Integration Region (IR) from 2007 to 2009 via an analysis of sociodemographic, epidemiological and operational indices. Methods This was a descriptive study using information generated by the SINAN. The Detection Coefficient of the Leprosy and Pregnancy Association (DCLP) epidemiological index was constructed to help interpret the endemicity parameters. The disease was considered hyperendemic when greater than two cases per 10,000 inhabitants were identified. Results During the study period, 149 associations were detected, with 14 hyperendemic counties: seven in 2007, five in 2008 and two in 2009. The Carajás Integrated Region displayed the highest DCLP index in the period. Eldorado dos Carajás had the single highest DCLP index (5.7/10,000 inhabitants, 2008), whereas the DCLP index in Conceição do Araguaia was very high in all three years. However, most counties displayed low or medium DCLP indices. The annual averages were 0.31 DCLP (2007), bass; 0.30 (2008), bass and 0.19 (2009), bass. The average DCLP index was 0.26, which is considered low. Three clusters of medium endemicity were identified by the average DCLP in the study period. Conclusions The analyses indicated that the surveillance program is still unsatisfactory in Pará. The interpretation of the endemicity parameters enabled qualitative and quantitative analyses to determine the epidemiological panorama of this association. The identification of high endemicity requires further clarification.

Produção e caracterização de espumas 3D obtidas por electrofiação para aplicação em engenharia de tecidos

A produção de estruturas tridimensionais poliméricas tem sido foco de estudo por parte da Engenharia de Células e Tecidos, pelo que mimetizam melhor as condições in vivo dos tecidos. A conjugação das propriedades eléctricas com arquitectura 3D permite uma regeneração tecidual mais eficaz. Desta forma este estudo incidiu na construção de scaffolds, que conjugasse as propriedades mecânicas, eléctricas e biológicas num só suporte. O processo utilizado para produção de scaffolds baseou-se na electrofiação de soluções poliméricas de PCL (8% m/m) com incorporação de óxido de grafeno em diferentes concentrações: 0.01%, 0.1% e 0.25% (m/V). Foram avaliados os parâmetros de electrofiação que permitiram a organização tridimensional. A composição química e a morfologia das membranas foram avaliadas por FTIR-ATR e por microscopia electrónica de varrimento (MEV), respectivamente. Através de ensaios de tracção e de permeabilidade estudou-se a influência de óido de grafeno na matriz polimérica. Foram feitas experiências de redução de óxido de grafeno nas fibras electrofiadas, tanto nas membranas como das espumas, através do uso de vapores de hidrazina. Este mecanismo mostrou-se ineficaz, uma vez que afectou a sua morfologia. As espumas foram avaliadas quanto à sua bioactividade e propriedades mecânicas (ensaios de compressão). Também foram realizados testes de viabilidade celular nas membranas e de adesão celular nas espumas, de forma a avaliar o seu potencial para aplicação biomédica. Os resultados destes ensaios revelaram que óxido de grafeno não apresenta efeitos citotóxicos para o organismo e a sua presença promove a adesão celular ao scaffold.

Jogo 3D online para reabilitação de pacientes afásicos

Esta plataforma foi projetada como auxílio complementar ao processo de reabilitação de doentes afásicos lusófonos. Uma gama de exercícios são disponibilizados de forma a induzir diferentes estímulos (compreensão escrita e auditiva e expressão escrita) sendo a grande maioria destes realizados dentro de um ambiente virtual em três dimensões onde o utilizador (dependendo da tarefa) pode interagir com objetos presentes dentro de uma casa. A principal particularidade desta plataforma reside no facto desta estar alojada online, dispensando instalações e permitindo um acompanhamento mais próximo por parte do terapeuta da fala do progresso feito pelo paciente. A ferramenta desenvolvida está disponível para visualização e teste no endereço www.weblisling.net.