Browsing by Issue Date, starting with "2024-02"
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- Assessing sleep quality of professional drivers: an analysis based on self-perceived and sleep companions' feedbackPublication . Lopes, T.; Faria, Brigida Monica; Oliveira, Alexandra; Pimenta, Rui; Reis, L. P.Portugal has been ranked as the fourth European country with the highest incidence of falling asleep while driving. The quality of sleep comprises both quantitative aspects, such as sleep duration and sleep latency, and qualitative aspects, such as mood and health status. Neglecting the quality and quantity of sleep can result in fatigue, affecting multiple aspects of safe driving, such as attentiveness to the road. Although quantitative measures of sleep are easy to assess, evaluating subjective aspects of sleep is more challenging. Poor sleep quality and habits were the most commonly cited reasons for falling asleep at the wheel. Given the high prevalence of road accidents in Portugal and the significant impact of sleep quality on driving safety, there is a need for comprehensive research on the sleep quality of professional drivers. Adult sleep is often a shared activity between sleep companions, making it a crucial aspect to investigate for a better understanding of sleep perceptions. The main objective of this study is to analyze the sleep quality of a population of Portuguese professional drivers and compare it with the responses given by their sleep companions.
- Data-Agnostic Model Poisoning against Federated Learning: A Graph Autoencoder ApproachPublication . Li, Kai; Zheng, Jingjing; Yuan, Xin; Ni, Wei; Akan, Ozgur B.; Poor, H. VincentThis paper proposes a novel, data-agnostic, model poisoning attack on Federated Learning (FL), by designing a new adversarial graph autoencoder (GAE)-based framework. The attack requires no knowledge of FL training data and achieves both effectiveness and undetectability. By listening to the benign local models and the global model, the attacker extracts the graph structural correlations among the benign local models and the training data features substantiating the models. The attacker then adversarially regenerates the graph structural correlations while maximizing the FL training loss, and subsequently generates malicious local models using the adversarial graph structure and the training data features of the benign ones. A new algorithm is designed to iteratively train the malicious local models using GAE and sub-gradient descent. The convergence of FL under attack is rigorously proved, with a considerably large optimality gap. Experiments show that the FL accuracy drops gradually under the proposed attack and existing defense mechanisms fail to detect it. The attack can give rise to an infection across all benign devices, making it a serious threat to FL.
- Analyzing the key decision factors for selecting the appropriate project management approachPublication . Reis, Ana Beatriz Gonçalves; Amaral, António Manuel Pereira da SilvaProjectization has emerged as a transformative approach to streamline work, bolstering companies’ competitive advantage and enabling the swift and high-quality execution of projects. However, this transition presents significant challenges in project management, especially when managers are deeply entrenched in a specific approach. To significantly enhance the chances of success, companies must choose the appropriate project management. This research conducted an in-depth review of the existing literature on project management, resulting in the selection of 45 highly relevant articles from a vast pool of 113 sources. Next, an interview protocol was developed and used in semi-structured interviews with ten experienced project managers. These project managers have experience using different methodologies and across various industries. A comparative analysis between literature and selected practitioners allowed for a comprehensive understanding of project management. The study's findings underscore the paramount significance of several key factors, namely, project scope, client culture, team culture, project duration and business sector. The first three factors have been discussed in prior literature. The fourth factor has been mentioned in prior work, but it has not been specifically discussed in detail how this factor can be used to guide the selection of the project management approach. The fifth factor is a new criterion proposed based on the results of the data analysis. This research contributes to science by highlighting which factors are important for project management and identifying a new factor to the literature. This study also contributes to practice by underscoring the vital role of selecting appropriate project management in an ever-evolving business landscape and by proposing the specific factors that must be considered to achieve project success.
- Polymorphisms and haplotypes of TOLLIP and MUC5B are associated with susceptibility and survival in patients with fibrotic hypersensitivity pneumonitisPublication . Mota, P.C.; Soares, M.L.; Ferreira, A.C.; F. Santos, Rita; Cavaleiro Rufo, J; Vasconcelos, D.; Carvalho, A.; Guimarães, S.; Vasques-Novo, F.; Cardoso, C.; Melo, N.; Alexandre, A.T.; Coelho, D.; Novais-Bastos, H.; Morais, A.Hypersensitivity pneumonitis (HP) is an interstitial lung disease with diverse clinical features that can present a fibrotic phenotype similar to idiopathic pulmonary fibrosis (IPF) in genetically predisposed individuals. While several single nucleotide polymorphisms (SNPs) have been associated with IPF, the genetic factors contributing to fibrotic HP (fHP) remain poorly understood. This study investigated the association of MUC5B and TOLLIP variants with susceptibility, clinical presentation and survival in Portuguese patients with fH. A case-control study was undertaken with 97 fHP patients and 112 controls. Six SNPs residing in the MUC5B and TOLLIP genes and their haplotypes were analyzed. Associations with risk, survival, and clinical, radiographic, and pathological features of fHP were probed through comparisons among patients and controls. MUC5B rs35705950 and three neighboring TOLLIP variants (rs3750920, rs111521887, and rs5743894) were associated with increased susceptibility to fHP. Minor allele frequencies were greater among fHP patients than in controls (40.7% vs 12.1%, P<0.0001; 52.6% vs 40.2%, P = 0.011; 22.7% vs 13.4%, P = 0.013; and 23.2% vs 12.9%, P = 0.006, respectively). Haplotypes formed by these variants were also linked to fHP susceptibility. Moreover, carriers of a specific haplotype (G-T-G-C) had a significant decrease in survival (adjusted hazard ratio 6.92, 95% CI 1.73–27.64, P = 0.006). Additional associations were found between TOLLIP rs111521887 and rs5743894 variants and decreased lung function at baseline, and the MUC5B SNP and radiographic features, further highlighting the influence of genetic factors in fHP. These findings suggest that TOLLIP and MUC5B variants and haplotypes may serve as valuable tools for risk assessment and prognosis in fibrotic hypersensitivity pneumonitis, potentially contributing to its patient stratification, and offer insights into the genetic factors influencing the clinical course of the condition.
- Metodologia Kaizen aplicada aos processos de após venda automóvelPublication . Brito, Miguel Lourenço Barca Rocha de; Mota, Luísa Maria Gaspar Morgado daA presente dissertação aborda a otimização dos processos de backoffice da Hyundai Portugal, o importador da marca automóvel no país. Para alcançar esse objetivo, foi adotada a metodologia Kaizen, visando a análise, o planeamento e a implementação de ações de melhorias. A base teórica para a compreensão desses métodos incluiu uma revisão bibliográfica que abrangeu a história da filosofia Kaizen, ferramentas de qualidade e a utilização de indicadores de desempenho (KPIs). A pesquisa incluiu uma análise dos processos em questão, investigando o estado atual de cada um e identificando oportunidades de melhoria. Três áreas de melhoria foram selecionadas para implementação. Primeiramente, foi introduzida a digitalização de contratos de extensão de garantia, o que resultou numa economia de aproximadamente 21.000 euros. Esta alteração não só reduziu custos, mas também minimizou o desperdício de tempo associado à gestão de processos, reduziu o consumo de papel e facilitou o armazenamento dos processos, que até então se baseava no arquivo físico. Foi também implementado um formulário "Hotline", que possibilitou aos reparadores autorizados submeterem dúvidas técnicas de forma padronizada. Tal resultou na diminuição do número de processos, redução do tempo médio gasto em cada um e melhoria na qualidade das informações submetidas. A terceira melhoria concentrou-se na viabilização da reparação das caixas redutoras de veículos elétricos, em oposição à substituição integral anteriormente praticada de forma exclusiva. Esta ação de melhoria reduziu os custos com veículos de substituição, gerou uma economia de cerca de 275 euros por caso, diminuiu os custos de reparação para os clientes em cerca de 4.300 euros. Permitiu ainda reduzir o tempo de imobilização dos veículos em 15 dias, aumentando a satisfação dos clientes e a eficiência da gestão da oficina. As implementações propostas demonstraram ganhos significativos, incluindo uma redução substancial de custos, diminuição do desperdício de tempo, agilização dos processos e aumento da satisfação do cliente. Estes resultados reforçam a relevância das ações de melhoria implementadas, e reforçam a eficácia da metodologia Kaizen na implementação, quotidiano de uma organização e aplicação de uma cultura de melhoria continua organizacional.
- Betulinic acid for glioblastoma treatment: Reality, challenges and perspectivesPublication . Fernandes, Sílvia; Vieira, Mariana; Prudêncio, Cristina; Ferraz, RicardoBetulinic acid is a naturally occurring compound that can be obtained through methanolic or ethanolic extraction from plant sources, as well as through chemical synthesis or microbial biotransformation. Betulinic acid has been investigated for its potential therapeutic properties, and exhibits anti-inflammatory, antiviral, antimalarial, and antioxidant activities. Notably, its ability to cross the blood–brain barrier addresses a significant challenge in treating neurological pathologies. This review aims to compile information about the impact of betulinic acid as an antitumor agent, particularly in the context of glioblastoma. Importantly, betulinic acid demonstrates selective antitumor activity against glioblastoma cells by inhibiting proliferation and inducing apoptosis, consistent with observations in other cancer types. Compelling evidence published highlights the acid’s therapeutic action in suppressing the Akt/NFκB-p65 signaling cascade and enhancing the cytotoxic effects of the chemotherapeutic agent temozolomide. Interesting findings with betulinic acid also suggest a focus on researching the reduction of glioblastoma’s invasiveness and aggressiveness profile. This involves modulation of extracellular matrix components, remodeling of the cytoskeleton, and secretion of proteolytic proteins. Drawing from a comprehensive review, we conclude that betulinic acid formulations as nanoparticles and/or ionic liquids are promising drug delivery approaches with the potential for translation into clinical applications for the treatment and management of glioblastoma.
- Lightweight data bridge for connecting self-service end-user analytic tools to NGSI-based IoT systemsPublication . Pereira, Rui HumbertoThe FIWARE and related projects aim to provide an open, sustainable ecosystem based on public standards and royalty-free that accelerates the development of Smart Solutions. The broker (Orion, Scorpio and Stellio) and additional components, named Generic Enablers (GE), provide means for collecting IoT data and feeding a data layer. The NGSI standard has a structural role in terms of interoperability, thus promoting the development of new GEs. However, this standard is not being adopted in analytic tools. In general, these tools connect to the IoT backend databases, which poses problems regarding data access control management and requires specialised IT support. Thus, it is not well suited for enterprise scenarios like, for instance, smart agriculture or smart industry, in which self-service tools, such as Power BI, Tableau and Qlik, are frequently used. We propose a lightweight connector for data analytic tools and IoT ecosystems based on NGSIv2/NGSI-LD/NGSI-TSDB. The proposed system provides web services based on JSON and CSV formats that those tools use without applying complex transformations in the data. Thus, nontechnical business users can consume IoT data on demand and use all the analytical capabil ities of these tools. We tested the system in an educational scenario where dashboards and an alytics processes were developed with minimal effort. The system has implemented a mechanism for access control management at the service/tenant level and several querying features. The system is now being implemented in a real public service scenario. In future versions, we intend to improve the system in terms of performance, security and add more query features.
- Autistic traits and event-related potentials in the general population: A scoping review and meta-analysisPublication . Mazer, Prune; Garcez, Helena; Macedo, Inês; Pasion, Rita; Silveira, Celeste; Sempf, Frederieke; Ferreira-Santos, FernandoDifferences in short and long-latency Event-Related Potentials (ERPs) can help us infer abnormalities in brain processing, considering early and later stages of stimuli processing across tasks and conditions. In autism research, the adult population remains largely understudied compared to samples at early stages of development. In this context, this scoping review briefly summarises what has been described in community and subclinical adult samples of autism. The current scoping review and meta-analysis includes 50 records (N = 1652) and comprehensively explores short and long-latency ERP amplitudes and their relationship with autistic traits in adult community samples. This meta-analysis identified, with small to medium effect sizes, distinctive patterns in late ERP amplitudes, indicating enhanced responses to visual stimuli and the opposite patterns to auditory tasks in the included sample. Additionally, a pattern of higher amplitudes was also found for the component P3b in autistic traits. Differential effects in visual and auditory domains are explored in light of the predictive processing framework for Autism. It remains possible that different brain mechanisms operate to explain symptoms related with different sensory modalities. P3b is discussed as a possible component of interest in future studies as it revealed a more robust effect for differentiating severity in the expression of autistic traits in adulthood
- Harvesting the power of green synthesis: gold nanoparticles tailored for prostate cancer therapyPublication . Oliveira, Marco; Sousa, André; Sá, Sara; Soares, Sílvia; Pereira, Ana Cláudia; Rocha, Ana Catarina; Pais, Patrick; Ferreira, Diogo; Almeida, Cátia; Luís, Carla; Lima, Cláudio; Almeida, Fábio; Gestoso, Álvaro; Duarte, Miguel-Correa; Barata, Pedro; Martins-Mendes, Daniela; Baylina, Pilar; Pereira, Carla F.; Fernandes, RúbenBiosynthetic gold nanoparticles (bAuNPs) present a promising avenue for enhancing biocompatibility and offering an economically and environmentally responsible alternative to traditional production methods, achieved through a reduction in the use of hazardous chemicals. While the potential of bAuNPs as anticancer agents has been explored, there is a limited body of research focusing on the crucial physicochemical conditions influencing bAuNP production. In this study, we aim to identify the optimal growth phase of Pseudomonas aeruginosa cultures that maximizes the redox potential and coordinates the formation of bAuNPs with increased efficiency. The investigation employs 2,6-dichlorophenolindophenol (DCIP) as a redox indicator. Simultaneously, we explore the impact of temperature, pH, and incubation duration on the biosynthesis of bAuNPs, with a specific emphasis on their potential application as antitumor agents. Characterization of the resulting bAuNPs is conducted using ATR-FT-IR, TEM, and UV-Vis spectroscopy. To gain insights into the anticancer potential of bAuNPs, an experimental model is employed, utilizing both non-neoplastic (HPEpiC) and neoplastic (PC3) epithelial cell lines. Notably, P. aeruginosa cultures at 9 h/OD600 = 1, combined with biosynthesis at pH 9.0 for 24 h at 58 ◦C, produce bAuNPs that exhibit smaller, more spherical, and less aggregated characteristics. Crucially, these nanoparticles demonstrate negligible effects on HPEpiC cells while significantly impacting PC3 cells, resulting in reduced viability, migration, and lower IL-6 levels. This research lays the groundwork for the development of more specialized, economical, and ecologically friendly treatment modalities.
- Otimização de um sistema híbrido de armazenamento de energia para melhor desempenho em custo e vida útilPublication . Preto, Miguel André Pinto; Silveira, Alexandre Miguel Marques daO desenvolvimento em larga escala das energias renováveis introduz novos desafios nos sistemas de energia, resultando em maior volatilidade no equilíbrio entre a geração e produção de energia nos mercados de eletricidade liberalizados. O armazenamento de energia desempenha um papel essencial na redução desse desequilíbrio, aliviando o congestionamento da rede e, assim, aprimorando a estabilidade e a confiabilidade do sistema. A escolha de um sistema de armazenamento de energia depende de vários fatores, incluindo a localização, a carga, a fonte de energia elétrica, os custos associados, bem como os impactos ambientais. As soluções de armazenamento híbrido têm o potencial polivalente e flexível e por esse motivo tem recebido atenção especial com visto o seu desempenho superior em algumas aplicações especificas. Este projeto tem como objetivo comparar o desempenho de um sistema híbrido de armazenamento de energia com o de uma única bateria, levando em consideração o custo de fornecimento de energia e o impacto ambiental. Para isso, aplicam-se dois problemas de otimização sendo que o modelo de programação linear gera um despacho de carregamento ótimo da bateria para fornecimento de energia, seja minimizando os custos ou o impacto ambiental, para uma carga genérica, incluindo a parcela responsável pelos custo da energia e a degradação das baterias. Foram analisados dois cenários, considerando o custo comparativo e o impacto ambiental aplicados a um edifício. Para cada cenário, foi feita a comparação de um sistema singular composto por uma bateria de lítio, com um sistema híbrido composto por um grupo de uma bateria de lítio e uma de cada uma das outras 6 tecnologias. Os resultados demonstram que parâmetros de desempenho, como eficiência e curva de degradação, exercem um impacto significativo nos custos finais e no impacto ambiental de várias tecnologias de armazenamento.
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