Exploring the role of O-Mannosylation in the modulation of E-Cadherin function in Gastric Cancer cell line models

Dissertação de mestrado em Bioquímica Aplicada – Biomedicina

Evaluating biomaterial-and microfluidic-based 3D tumor models

Cancer is a major cause of morbidity and mortality worldwide, with a disease burden estimated to increase in the coming decades. Disease heterogeneity and limited information on cancer biology and disease mechanisms are aspects that 2D cell cultures fail to address. We review the current "state-of-the-art" in 3D Tissue Engineering (TE) models developed for and used in cancer research. Scaffold-based TE models and microfluidics, are assessed for their potential to fill the gap between 2D models and clinical application. Recent advances in combining the principles of 3D TE models and microfluidics are discussed, with a special focus on biomaterials and the most promising chip-based 3D models.

Utilização de modelos de simulação para a melhoria de um sistema de restauração: estudo de caso de uma cantina universitária

Dissertação de mestrado em Engenharia Industrial

Single line for assembly just-in-sequence multiple models

Programa Doutoral em Líderes para as Indústrias Tecnológicas

O ajustamento psicossocial de jovens com consumos de substâncias psicoativas em escolas profissionais do grande Porto

Tese de Doutoramento em Estudos da Criança (Área de Especialidade Psicologia do Desenvolvimento e Educação)

Metabolic engineering with multi-objective optimization of kinetic models

Kinetic models have a great potential for metabolic engineering applications. They can be used for testing which genetic and regulatory modifications can increase the production of metabolites of interest, while simultaneously monitoring other key functions of the host organism. This work presents a methodology for increasing productivity in biotechnological processes exploiting dynamic models. It uses multi-objective dynamic optimization to identify the combination of targets (enzymatic modifications) and the degree of up- or down-regulation that must be performed in order to optimize a set of pre-defined performance metrics subject to process constraints. The capabilities of the approach are demonstrated on a realistic and computationally challenging application: a large-scale metabolic model of Chinese Hamster Ovary cells (CHO), which are used for antibody production in a fed-batch process. The proposed methodology manages to provide a sustained and robust growth in CHO cells, increasing productivity while simultaneously increasing biomass production, product titer, and keeping the concentrations of lactate and ammonia at low values. The approach presented here can be used for optimizing metabolic models by finding the best combination of targets and their optimal level of up/down-regulation. Furthermore, it can accommodate additional trade-offs and constraints with great flexibility.

Development of computational and experimental methods for biomass composition and evaluation of its impact in genome-scale models prediction

The use of genome-scale metabolic models has been rapidly increasing in fields such as metabolic engineering. An important part of a metabolic model is the biomass equation since this reaction will ultimately determine the predictive capacity of the model in terms of essentiality and flux distributions. Thus, in order to obtain a reliable metabolic model the biomass precursors and their coefficients must be as precise as possible. Ideally, determination of the biomass composition would be performed experimentally, but when no experimental data are available this is established by approximation to closely related organisms. Computational methods however, can extract some information from the genome such as amino acid and nucleotide compositions. The main objectives of this study were to compare the biomass composition of several organisms and to evaluate how biomass precursor coefficients affected the predictability of several genome-scale metabolic models by comparing predictions with experimental data in literature. For that, the biomass macromolecular composition was experimentally determined and the amino acid composition was both experimentally and computationally estimated for several organisms. Sensitivity analysis studies were also performed with the Escherichia coli iAF1260 metabolic model concerning specific growth rates and flux distributions. The results obtained suggest that the macromolecular composition is conserved among related organisms. Contrasting, experimental data for amino acid composition seem to have no similarities for related organisms. It was also observed that the impact of macromolecular composition on specific growth rates and flux distributions is larger than the impact of amino acid composition, even when data from closely related organisms are used.

Predicting SO2 pollution incidents by means of additive models with optimum variable selection

The aim of this paper is to predict time series of SO2 concentrations emitted by coal-fired power stations in order to estimate in advance emission episodes and analyze the influence of some meteorological variables in the prediction. An emission episode is said to occur when the series of bi-hourly means of SO2 is greater than a specific level. For coal-fired power stations it is essential to predict emission epi- sodes sufficiently in advance so appropriate preventive measures can be taken. We proposed a meth- odology to predict SO2 emission episodes based on using an additive model and an algorithm for variable selection. The methodology was applied to the estimation of SO2 emissions registered in sampling lo- cations near a coal-fired power station located in Northern Spain. The results obtained indicate a good performance of the model considering only two terms of the time series and that the inclusion of the meteorological variables in the model is not significant.

The Portuguese programme one laptop per child: political, educational and social impact

In 2008, the XVII Portuguese Constitutional Government launched the ‘e.escolinha’ programme, within the Technological Plan for Education, which set out the distribution of a computer, called ‘Magalhães’, designed for chil-dren attending the 1st cycle of basic education. Suspended in 2011 by the XIX Government, this programme has allowed, however, almost 500 000 children to have access to a personal computer. It was expected that this political measure would “revolutionise” the national education system by bringing changes to the pedagogical practices of teachers and the learning processes of children and by achieving educational success, in general. Based on documental analysis and on a set of interviews with key decision-makers in conceiving, implementing and monitoring this governmental initiative, the fi rst part of this chapter presents and analyses the ‘e.escolinha’ initiative and the policies be-hind that governmental programme, seeking to disassemble those objectives and provide some insights into the relationship between discourses, rhetoric, and reality. After that, the chapter focuses on children’s uses and practices with the ‘Magalhães’ laptop, at school and at home. Based on the results of questionnaires fi lled in by approximately 1500 children from 32 First Cycle public schools of the municipality of Braga (north of Portugal) and also from questionnaires applied to their parents and teachers, this chapter intends to analyse the real impact of this initiative for children, family and school. It also seeks to discuss the contribution of this educational policy to children’s digital literacy and also to their own and their families’ social and digital inclusion. To understand if it represented an added value to teachers’ pedagogical practice is another of its aims. The fi ndings point out a major focus on technology and access rather than on uses and competences or even on social, educational and cultural change. In fact, a major conclusion is the existence of a strong gap between the policy and the practices, typical of a top-down policy design. This study is an integrant part of a research project titled “Navigating with ‘Magalhães’: Study on the Impact of Digital Media in Schoolchildren” conducted at the University of Minho, Portugal, financed by the Portuguese Foundation for Science and Technology [PTDC/CCI-COM/101381/2008] and co-funded by the European Regional Development Fund [COMPETE: FCOMP-01-0124-FEDER-009056].

Mediação Penal Juvenil: um novo paradigma de resposta à delinquência

Dissertação de mestrado em Direito Judiciário (Direitos Processuais e Organização Judiciária)

Avaliação externa de escolas e avaliação externa de aprendizagens no contexto institucional: um estudo paralelo sobre Brasil e Portugal

Dissertação de mestrado em Ciências da Educação (área de especialização em Desenvolvimento Curricular e Inovação Educativa)

Modelos de regressão multinível no estudo do desempenho escolar

Dissertação de mestrado em Estatística

A critical evaluation of methods for the reconstruction of tissue-specific models

Under the framework of constraint based modeling, genome-scale metabolic models (GSMMs) have been used for several tasks, such as metabolic engineering and phenotype prediction. More recently, their application in health related research has spanned drug discovery, biomarker identification and host-pathogen interactions, targeting diseases such as cancer, Alzheimer, obesity or diabetes. In the last years, the development of novel techniques for genome sequencing and other high-throughput methods, together with advances in Bioinformatics, allowed the reconstruction of GSMMs for human cells. Considering the diversity of cell types and tissues present in the human body, it is imperative to develop tissue-specific metabolic models. Methods to automatically generate these models, based on generic human metabolic models and a plethora of omics data, have been proposed. However, their results have not yet been adequately and critically evaluated and compared. This work presents a survey of the most important tissue or cell type specific metabolic model reconstruction methods, which use literature, transcriptomics, proteomics and metabolomics data, together with a global template model. As a case study, we analyzed the consistency between several omics data sources and reconstructed distinct metabolic models of hepatocytes using different methods and data sources as inputs. The results show that omics data sources have a poor overlapping and, in some cases, are even contradictory. Additionally, the hepatocyte metabolic models generated are in many cases not able to perform metabolic functions known to be present in the liver tissue. We conclude that reliable methods for a priori omics data integration are required to support the reconstruction of complex models of human cells.

Introduction [to Contact force models for multibody dynamics]

"Series: Solid mechanics and its applications, vol. 226"

Pure elastic contact force models

"Series: Solid mechanics and its applications, vol. 226"