Biblioteca Digital do IPB
Repositório de Publicações do Instituto Politécnico de Bragança
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Machine learning prediction of adolescent obesity using physical fitness data
Publication . Sampaio, Tatiana; Encarnação, Samuel; Amaro, Bruna; Ribeiro, Joana; Branquinho, Luís; Monteiro, António M.; Teixeira, José Eduardo; Hattabi, Soukaina; Sortwell, Andrew; Leite, Luciano Bernardes; Malheiro, Alexandra; Rodrigues, Pedro M.; Beat Knechtle; Flores, Pedro Miguel; Forte, Pedro
The escalating prevalence of obesity among adolescents has emerged as a critical global public health challenge. Machine learning techniques have been used to predict obesity in adolescents. This study aimed to develop and validate a robust obesity prediction model for adolescents using this hybrid approach, leveraging data from a diverse cross-sectional population-based study. The hybrid method combines statistical inference with non-linear machine learning to enhance prediction accuracy. Physical fitness data were collected from the FITescola® tests. Multiple tests were employed to evaluate physical fitness. Multiple Poisson's multiple regression method was applied to identify the most predictive variables set of the adolescent's body mass index (BMI) classification. The model's goodness-of-fit statistics indicate a strong fit, with a log-likelihood of 8068.6 and a Pseudo R-squared value of 0.8853, where the aerobic fitness (AF), upper limb strength (ULS) and lower limb flexibility (LLF) presented an inverse association with the adolescent's BMI. In contrast the adolescent's core strength presented a positive association with their body mass. The random forest regression showed that an average of 35 repetition on the yo-yo test predicted a healthy BMI percentile [predBMIperc = 0.31]. In addition, the model presented good validity [MAE = 0.36, MSE = 0.20, RMSE = 0.45, R2 = 0.54]. The model's strong fit and accurate random forest regression's predictions suggest that physical fitness components, such as aerobic fitness, upper limb strength, lower limb power, and core strength, play a significant role in obesity risk among adolescents.
An experimental analysis on the thermal performance of rammed earth walls
Publication . Luso, Eduarda; Cabello, Isabel; Silva, Rui A.; Briga-Sá, Ana
Earth has been used as a building material since the beginning of civilizations and its utilization was widespread to most regions of the world, promoted by the high availability, easy access and low cost of the material. As result of the generalised use of raw earth as building material, many earthen building techniques were developed through time, where adobe masonry, rammed earth and wattle-and-daub are among the most important. Currently, it is estimated that one quarter of the world's population lives in buildings made of earth. However, during the last century, earthen materials fell into disuse in several developed countries with the popularization of concrete, steel and fire bricks. Nevertheless, earthen architecture has been receiving increasing attention in the last few decades, driven by its green building potential and by other features of earthen materials, which includes, among others, unique aesthetics and hygrothermal regulation capacity.
Several studies have been developed to characterize earthen solutions concerning physical and mechanical properties. However, regarding the thermal behaviour, it is known that the thermal conductivity of rammed earth is a parameter that depends on the characteristics of the soil (particle size distribution, mineralogy, etc.) and moisture content. Thus, given the soils variability, it becomes clear that further investigation should be addressed to characterize the thermal performance of rammed earth solutions, contributing to define more accurate thermal conductivity values for the design of rammed earth buildings. On this regard, this paper presents an experimental study that aims to characterize the thermal behaviour of rammed earth built with different soils and with different thicknesses. A continuous measurement allowed to obtain heat fluxes, inner surface temperatures and the thermal transmission coefficient of the tested rammed earth walls solutions. The results obtained so far confirmed that the type of soil and thickness significantly influences the thermal behaviour of the earthen material. It was also observed that the thermal transmission coefficient of a 50 cm thick wall is about 30% lower than the one verified for the wall with 35 cm, built with the same soil.
Avaliação e caracterização do ambiente rural construído do Parque Natural de Montesinho, Portugal. O projeto INHAVIT
Publication . Luso, Eduarda; Ferreira, Débora
Em Portugal, nas últimas décadas, tem-se verificado um aumento da população e das cidades situadas no litoral e, pelo contrário, uma diminuição em localidades do interior, com maior gravidade nas zonas rurais. As causas são complexas e não consensuais, mas percebe-se claramente que fatores como a falta de investimento no interior, a emigração e migração para um litoral cada vez mais autista na sua relação com o resto do território, o abandono da agricultura e o envelhecimento da população constituem ingredientes suficientes para potenciar a desertificação de algumas zonas do país.
O abandono e desertificação de aldeias não é no entanto, um problema só de Portugal. Embora Portugal seja um dos países mais afetados por esta problemática que atinge todo o território nacional, trata-se de um problema europeu que se tem vindo a acentuar a partir da segunda metade do século XX.
Preocupados com este facto, que põe em risco o elevado abandono de aldeias e lugares do interior de Portugal, em particular os situados no nordeste transmontano, o Projeto InHaVit - Abordagens sustentáveis para a reabilitação e revitalização do património cultural construído no Parque Natural do Montesinho (PNM), financiado pela FCT – Fundação de Ciência e Tecnologia, tem como objetivo principal a avaliação e caracterização: (1) do ambiente rural construído do PNM, ao nível dos edifícios e ao nível das aldeias; e (2) de fatores socioeconómicos e ambientais que contribuam para a vulnerabilidade das aldeias e arquitetura vernacular do PNM. O conhecimento profundo destes aspetos ajudará a compreender as razões pelas quais se deu o abandono progressivo das aldeias. No final, o projeto irá propor estratégias de mitigação de riscos, reabilitação e conservação do património edificado, reconhecendo que a valorização e preservação da arquitetura vernácula é um elemento chave da identidade cultural e que se pode tornar um fator privilegiado para o desenvolvimento local.
Este artigo pretende mostrar a metodologia de trabalho relativo ao levantamento “in-situ” efetuada até ao momento, relativos ao ponto (1), bem como de alguns aspetos muito particulares desta região nomeadamente dos telhados em lousa e dos moinhos de água.
Biomonitoring of wildfire emissions exposure among firefighters during active fire missions
Publication . Barros, B.; Paiva, A.M.; Azevedo, R.; Alves, Sara Elisa Brás;; Esteves, F.; Fernandes, Adília; Vaz, Josiana A.; Slezakova, K.; Pereira, M.C.; Costa, S.; Almeida, A.; Teixeira, J. P.; Oliveira, M.; Morais, S.
The aim of this study was to conduct a multidisciplinary biomonitoring assessment of the exposure and health
impacts of wildfire emissions on firefighters from the Northern Portugal, one of the regions most affected by
wildfires. Firefighters from fourteen fire stations participated in pre- and post-exposure sampling campaigns
during two consecutive years. Self-reporting biometric characteristics, lifestyle, clinical information, career
years, environmental/occupational exposure along with urinary biomarkers of polycyclic aromatic
hydrocarbons metabolites (OHPAHs), metal(loid)s [from the priority pollutant lists compiled by the Agency
for Toxic Substances and Disease Registry 14, United States Environmental Protection Agency 11, and the
Human Biomonitoring for Europe Initiative priority 4], lung injury, lipid peroxidation, DNA damage, blood
pressure, cardiac frequency, and hemogram were evaluated (Barros et al., 2025; Esteves et al., 2025; Paiva et
al., 2024a; Paiva et al., 2024b). Stronger correlations were found between OHPAHs and metal(loid) levels and
effect biomarkers after wildfire combat in comparison to pre-exposure. Wildfire exposure increased urinary
-smokers. For the latter,
copper, cadmium and barium ions correlated with lung injury; antimony and cadmium correlated with lipid
peroxidation; DNA oxidation correlated with antimony, cadmium, copper, lead, zinc, selenium, and rubidium
levels. Moreover, arsenic, antimony, lead, and copper induced lipid peroxidation, and lead was linked with
DNA oxidation among wildfire-exposed smokers. Significant positive correlations were found for age and/or
career length with cadmium, lead, barium, strontium, and mercury, and for body mass index with arsenic.
These results point to an increased risk of health effects both in non-smoking and smoking firefighters because
of their occupation, highlighting the necessity to strengthen prevention strategies.
Understanding Dropout in Postgraduate Education: Challenges and Institutional Responses
Publication . Fernandes, Joana M.S.R.
Despite growing enrolment in postgraduate education, completion rates remain low, often falling below those of undergraduate programmes. This disparity has raised concerns about the adequacy of current retention strategies, which are frequently designed with undergraduate students in mind and may overlook the specific needs of postgraduate learners. Master’s students often face distinct challenges, including balancing professional responsibilities, aca-demic demands, and family obligations, all of which contribute to a heightened risk of dropout. This study investigates the institutional factors contributing to non-completion in master’s education through a qualitative case study at a pub-lic higher education institution in Portugal. Using an adapted Delphi methodol-ogy, data were collected through semi-structured interviews with first-year stu-dents and follow-up interviews with postgraduates to validate and deepen the findings. The results reveal three key areas influencing student retention: the early alignment between coursework and dissertation topics, the consistency and support provided by thesis supervisors, and the degree of flexibility in insti-tutional scheduling and workload management. Based on these insights, the study proposes practical recommendations such as structured dissertation time-lines and increased opportunities for academic engagement, including participa-tion in conferences. These measures can help higher education institutions re-duce attrition and improve the postgraduate experience by aligning academic structures with students' lived realities.