Hand gesture recognition system based in computer vision and machine learning: Applications on human-machine interaction

Tese de Doutoramento em Engenharia de Eletrónica e de Computadores

Zeolite-based nanomaterials for the control of opportunistic pathogenic microorganisms

Dissertação de mestrado em Applied Biochemistry (área de especialização em Biomedicine)

All different or all the same? Exploring the diversity of professional practices in Portuguese school psychology

"Published online: 29 March 2016"

The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration

Abstract This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with periodic acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD.

Forecasting human entrances at a commercial store using facial recognition data

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Actividade física e qualidade de vida na gravidez

Pouco se conhece acerca da actividade física e qualidade de vida da mulher na gravidez. Este estudo teve como objectivos 1) comparar os padrões de actividade física antes e durante a gravidez, 2) avaliar a percepção da qualidade de vida relacionada com a saúde durante os primeiros seis meses de gestação, e 3) comparar a percepção da qualidade de vida nas mulheres activas e insuficientemente activas considerando as recomendações de saúde pública. Método: Estudo longitudinal com 59 grávidas seleccionadas em consultórios médicos privados. Às 10-15 semanas foi recolhida informação sociodemográfica e médica, bem como informação sobre a actividade física três meses antes da concepção. Medidas de auto-relato foram administradas entre as 10-15 semanas e as 19-24 semanas de gestação para avaliar o tempo de actividade física (QAFG) (no trabalho, lazer, deslocações) e a qualidade de vida (SF-36). Resultados: A prevalência de actividade física recomendada é menor durante do que antes da gravidez (16.7% e 17.5% nos 1.º e 2.º trimestres, respectivamente vs. 47.4% antes da gravidez). Com a gravidez, não se verificaram alterações no tempo médio em diferentes tipos de actividade física, mas a actividade física no lazer registou uma diminuição significativa no 1.º trimestre face ao período anterior à concepção. Em comparação com uma amostra normativa de mulheres portuguesas, as grávidas apresentam, nos dois primeiros trimestres de gestação, uma percepção de qualidade da vida mais positiva na generalidade das dimensões do SF-36. No 2.º trimestre, o nível de limitação é significativamente maior nas dimensões físicas, à excepção da Dor Corporal, e nos resultados sumários do Componentes Físico e Mental. As mulheres que no 1.º trimestre atingem os níveis recomendados de actividade física no lazer (≥150 minutos por semana) apresentam melhor estado de saúde geral e estados de humor mais positivos do que as menos activas. Conclusão: A actividade física no lazer, embora diminua após a concepção, tem um impacto positivo na percepção do estado saúde geral e estados de humor da grávida, o que sugere a sua importância para a saúde da mulher também durante este período da vida.

Development and characterization of lipid-based nanosystems for controlled release of bioactive compounds

Tese de Doutoramento em Engenharia Química e Biológica.

Transcranial direct current stimulation based metaplasticity protocols in working memory

It has been already shown that delivering tDCS that are spaced by an interval alters its impact on motor plasticity. These effects can be explained, based on metaplasticity in which a previous modification of activity in a neuronal network can change the effects of subsequent interventions in the same network. But to date there is limited data assessing metaplasticity effects in cognitive functioning.

Fine time scaling of purifying selection on human nonsynonymous mtDNA mutations based on the worldwide population tree and mother-child pairs

A high-resolution mtDNA phylogenetic tree allowed us to look backward in time to investigate purifying selection. Purifying selection was very strong in the last 2,500 years, continuously eliminating pathogenic mutations back until the end of the Younger Dryas (∼11,000 years ago), when a large population expansion likely relaxed selection pressure. This was preceded by a phase of stable selection until another relaxation occurred in the out-of-Africa migration. Demography and selection are closely related: expansions led to relaxation of selection and higher pathogenicity mutations significantly decreased the growth of descendants. The only detectible positive selection was the recurrence of highly pathogenic nonsynonymous mutations (m.3394T>C-m.3397A>G-m.3398T>C) at interior branches of the tree, preventing the formation of a dinucleotide STR (TATATA) in the MT-ND1 gene. At the most recent time scale in 124 mother-children transmissions, purifying selection was detectable through the loss of mtDNA variants with high predicted pathogenicity. A few haplogroup-defining sites were also heteroplasmic, agreeing with a significant propensity in 349 positions in the phylogenetic tree to revert back to the ancestral variant. This nonrandom mutation property explains the observation of heteroplasmic mutations at some haplogroup-defining sites in sequencing datasets, which may not indicate poor quality as has been claimed.

Systems biology approaches for the design of novel Saccharomyces cerevisiae winemaking strains for enhanced flavour compounds synthesis

Tese de Doutoramento em Biologia Ambiental e Molecular

Development of a poly(L-Lactic acid) based drug release system

Dissertação de mestrado em Biofísica e Bionanossistemas

Differences in muscular activity between obese and non-obese workers during manual lifting

The prevalence of obesity is increasing throughout the workforce. Manual lifting tasks are common and can produce significant muscle loading. This study compared muscular activity between obese and non-obese subjects, using surface Electromyography (EMG), during manual lifting. Six different lifting tasks (with 5, 10 and 15 kg loads in free and constrained styles) were performed by 14 participants with different obesity levels. EMG data normalization was based on the percentage of Maximum Contraction during each Task (MCT). Muscle Activation Times (AT) before each task were also evaluated. The study suggests that obesity can increase MCT and delay muscle AT. These findings reinforce the need to develop further studies focused on obesity as a risk factor for the development of musculoskeletal disorders.

Physical activity, health-related quality of life and depression during pregnancy

This study examines physical activity patterns among women, from pre-pregnancy to the second trimester of pregnancy, and the relationship between physical activity status based on physical activity guidelines and health-related quality of life (HRQoL) and depression over pregnancy. 56 healthy pregnant women self reported physical activity, HRQoL and depression at 10-15 and 19-24 weeks of pregnancy and physical activity before pregnancy. Whereas vigorous leisure physical activity decreased after conception, moderate leisure physical activity and work related physical activity remained stable over time. The prevalence of recommended physical activity was 39.3% and 12.5% in the 1st and 2nd trimesters of pregnancy respectively, and 14.3% pre-pregnancy. From the 1st to the 2nd pregnancy trimester, most physical HRQoL dimensions scores decreased and only mental component increased, independently of physical activity status. No changes in mean depression scores were observed. These data suggest that physical activity patterns change with pregnancy and that physical and mental components are differentially affected by pregnancy course, independently of physical activity status.