Browsing by Issue Date, starting with "2025-01-31"
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- myAURA: a personalized health library for epilepsy management via knowledge graph sparsification and visualizationPublication . Correia, Rion Brattig; Rozum, Jordan C.; Cross, Leonard; Felag, Jack; Gallant, Michael; Guo, Ziqi; Herr II, Bruce W.; Min, Aehong; Sanchez-Valle, Jon; Rocha, Deborah Stungis; Valencia, Alfonso; Wang, Xuan; Börner, Katy; Miller, Wendy; Rocha, Luis M.Objectives: Report the development of the patient-centered myAURA application and suite of methods designed to aid epilepsy patients, caregivers, and clinicians in making decisions about self-management and care. Materials and Methods: myAURA rests on an unprecedented collection of epilepsy-relevant heterogeneous data resources, such as biomedical databases, social media, and electronic health records (EHRs). We use a patient-centered biomedical dictionary to link the collected data in a multilayer knowledge graph (KG) computed with a generalizable, open-source methodology. Results: Our approach is based on a novel network sparsification method that uses the metric backbone of weighted graphs to discover important edges for inference, recommendation, and visualization. We demonstrate by studying drug-drug interaction from EHRs, extracting epilepsy-focused digital cohorts from social media, and generating a multilayer KG visualization. We also present our patient-centered design and pilot-testing of myAURA, including its user interface. Discussion: The ability to search and explore myAURA’s heterogeneous data sources in a single, sparsified, multilayer KG is highly useful for a range of epilepsy studies and stakeholder support. Conclusion: Our stakeholder-driven, scalable approach to integrating traditional and nontraditional data sources enables both clinical discovery and data-powered patient self-management in epilepsy and can be generalized to other chronic conditions.
- Synergistic effect of ultrasound and osmotic pretreatment on the drying kinetics and antioxidant properties of Satkara (Citrus macroptera)Publication . Hossain, Mohammad Afzal; Shaha, Limon Chandra; Romen, Tasnim Islam; Sarkar, Animesh; Biswas, Rahul; Ahmed, Shafi; Islam, Md. Atiqual; Muntasir, Fahim; Patwary, Md. Amjad; Morais, Rui M. S. C.; Morais, Alcina M. M. B.This study aimed to investigate the effects of combined ultrasound and osmotic pretreatment conditions on the drying kinetics and antioxidant properties, such as total phenolic content (TPC), total flavonoid content (TFC), vitamin C content, and DPPH radical scavenging activity, of dried Citrus macroptera (Satkara) fruits. The fruit slices were immersed in 10% aqueous solutions of sucrose (S), glucose (G), and fructose (F) followed by an ultrasound treatment (40 kHz) for 10, 20, or 30 min. The samples were then dried in a convective oven at 50, 60, or 70 ◦C and 30% relative humidity with a constant air velocity of 3 m s−1 . Four thin-layer kinetic models, namely Page, Newton, Henderson and Pabis, and Logarithmic, were evaluated. Among these, Page was found to be the most suitable model for predicting the drying kinetics. The pretreatment process accelerated the drying process significantly, reducing the drying time up to 6 h. Additionally, the pretreated samples exhibited improved retention of quality attributes, with vitamin C being best preserved in S solutions, TPC in both S and F solutions, TFC in F solutions, and DPPH in all three sugar solutions (S, F, and G). The application of ultrasound during osmotic treatment also had a positive impact on TPC and TFC retention, whereas it presented a negative effect on vitamin C when used for a prolonged duration and a negligible one on the antioxidant capacity. Overall, this study provides a new perspective on the drying kinetics of Satkara fruits, and their respective properties after drying, and being subjected to combined ultrasound and osmotic pretreatment. These findings will contribute to the development of effective and efficient drying methods suitable for industrial applications to produce dried Satkara products with a minimum quality degradation.
- (Welfare) effects of joint versus independent bargainingPublication . Borsi, Dominik Luis Pablo; Brito, DuarteThis thesis examines the impact of joint bargaining on market outcomes and welfare in comparison to individual negotiations. Using theoretical models rooted in game theory and industrial organization, it introduces the Nash-in-Nash bargaining framework into the Hotelling model for the first time. The analysis considers three distinct scenarios: individual firm price setting, collective consumer bargaining with producers, and collective bargaining on both sides of the market. These scenarios are further investigated under both symmetric and asymmetric cost structures. With respect to the bargaining setup, the findings reveal that negotiating jointly, rather than independently, can improve a party's outcome (surplus), a result that applies to both consumers and producers. Bargaining power primarily influences the distribution of welfare without affecting the total amount of welfare generated. However, the presence of cost asymmetry adds an efficiency dimension to the bargaining process, where greater consumer bargaining power can enhance total welfare by aligning prices and demand allocation more effectively with cost structures. The study contributes to the understanding of bargaining dynamics by offering policy recommendations and identifying pathways for further research, including for example the incorporation of heterogeneous consumer preferences and dynamic negotiation strategies.
- Backward partial cross-ownership and upstream R&DPublication . Ruivo, Pedro Vilas; Brito , DuarteIn this article, we investigate the welfare effects of vertical backward ownership in vertical markets with upstream cost-reducing RD investments, emphasizing the role of input price discrimination. We first examine how backward partial cross- ownerships among firms influences welfare outcomes under uniform input pricing and input price discrimination. Under uniform input pricing, we replicate the in- variance result of Greenlee and Raskovich (2006) but demonstrate that this in- variance disappears when investment is incorporated. In this case, vertical partial cross-ownerships consistently enhance welfare. Under input price discrimination, the results are more nuanced: increasing cross ownership may either improve or reduce welfare. Finally, we take the ownership structure as given and study the welfare effects of input price discrimination. We find that transitioning from uniform input pricing to input price discrimination can have both positive and negative welfare implications, depending on specific parameter configurations.
- O desempenho académico em função da qualidade do sono, atenção executiva e ansiedade em período de exames universitários de diferentes cursosPublication . Ferreira, Carina Sofia Correia; Rato, Joana Maria Rodrigues; Caldas, Alexandre CastroEnquadramento Teórico: O desempenho académico de estudantes universitários pode ser influenciado por diversos fatores, desde a qualidade do sono aos agentes stressores, especialmente durante os períodos de exames. Estes fatores, já discutidos na literatura, são críticos para a compreensão das variações no sucesso académico no ensino superior. O presente estudo investigou a relação entre a qualidade do sono, a atenção executiva e os estados de ansiedade, identificando possíveis preditores do sucesso académico em estudantes de diferentes áreas de curso. Metodologia: Foi adotada uma abordagem correlacional e comparativa com uma amostra de 51 estudantes universitários de uma universidade privada na zona geográfica da grande Lisboa, oriundos de cursos de Medicina, Economia e Direito. Os instrumentos de medida foram aplicados no período de exames e incluíram o Índice de Qualidade do Sono de Pittsburgh (PSQI), a Escala de Sonolência Epworth (ESE), o Inventário de Ansiedade Estado-Traço (STAI), o Inventário de Depressão de Beck (BDI-II) e testes neuropsicológicos como o Teste Stroop e a tarefa de controlo inibitório Go/No-Go. Resultados: Os resultados evidenciaram diferenças significativas entre estudantes dos diferentes cursos, com os estudantes de Medicina a apresentar uma qualidade de sono inferior e os de Direito a demonstrar pior desempenho na atenção executiva. Identificouse a qualidade do sono e a ansiedade-estado como preditores significativos do desempenho académico, enquanto a atenção executiva não demonstrou predição relevante. Conclusão: Os resultados destacam a necessidade de promover estratégias que melhorem a qualidade do sono e regulem a ansiedade nos estudantes universitários, independentemente da área de estudo. O suporte institucional é crucial para ajudar os estudantes a gerir as exigências académicas e a saúde mental, particularmente durante os períodos de maior stress, como os exames.
- Safe bets : forecasting who’ll buy home alarmsPublication . Azenha, Ricardo Jorge Pinto; Paiva, NunoTelecommunications companies face constant pressure to adapt to technological advancements and updates. Simultaneously, these organizations explore new revenue streams to sustain growth and address competitive pressures. NOS expanded its operations into the home alarm market in 2022 in partnership with Securitas, a European leader in the security sector. This strategy aligns with the prospects of increased demand for smart devices in Portugal and the increased benefits of targeting adjacencies. Cross-selling to existing customers is one of the growth levers of this new service. NOS already has segmentation criteria for the next best offer system. However, for Alarms specifically, business rules are used to select the most likely-to-buy customers due to its recency. The aim of this thesis is to (1) collaborate with the marketing product team to identify key drivers influencing the purchase of alarm products and (2) develop a propensity model using features that best capture these drivers. Logistic Regression, Decision Tree, Random Forest, and XGBoost were tested. Emphasis was placed on geographical variables, as significant work had already been conducted to map alarm installations at specific coordinates across Portugal. The results of this study showed that financial variables play a crucial role in calculating the likelihood of a customer buying this service, together with the previous relationship with NOS. Geographical variables showed relevance for improving the performance of the models but with a low degree of significance. Finally, it was possible to develop models with higher performance compared with NOS current approach.
- Research framework for food security and sustainabilityPublication . Papargyropoulou, Effie; Ingram, John; Poppy, Guy M.; Quested, Tom; Valente, Clara; Jackson, Lee Ann; Hogg, Tim; Achterbosch, Thom; Sicuro, Emanuele Paolo; Bryngelsson, Susanne; Guelinckx, Isabelle; Dael, Peter Van; Dye, LouiseThis article presents a framework for food security and sustainability research, developed by industry, academia, and public sector experts. Key priorities for collaborative research include reassessing food system contexts and drivers, adapting food system activities, transforming food system outcomes, developing and applying food system methodologies, and adopting an ethical and just lens. The framework emphasises the need for coordinated action across multiple scales and sectors, focusing on synergies and trade-offs as opposed to isolated food activities, to address complex challenges in food security and sustainability.
- The dual impact of carbon emissions and financial performancePublication . Bohus, Ádám Gábor; Venter, ZoëThis thesis examines the relationship between carbon emissions and financial performance in Asian markets, employing Panel Vector Autoregression (PVAR) and pooled Ordinary Least Squares (OLS) regression. The study utilizes a comprehensive dataset covering firm-level data from 2007 to 2022, allowing for a robust analysis of the complex relationships between environmental and financial factors. The findings provide weak evidence for a carbon premium, suggesting that investors may demand higher returns from firms with high carbon emissions to compensate for environmental risks. Additionally, the results indicate that emission-intensive firms may face financial risks, as higher emission intensity is associated with increased leverage. However, other financial metrics, such as Return on Assets (ROA) and Market-to-Book Ratio, show inconsistent relationships with carbon emissions. These results highlight the challenges of reducing emissions and their limited influence on financial outcomes in emerging markets where regulatory pressures and market dynamics differ significantly from those in advanced economies. The study underscores the importance of tailored regulatory frameworks and strategic investments in sustainability, offering insights for policymakers and firms trying to find the golden path between environmental and financial goals.
- Independence and crises : how central bank independence is affected by financial crisesPublication . Mendes, Bruno Lopes; Correia, Isabel HortaThis study examines the impact of different types of financial crises—banking, debt, and currency—on changes in Central Bank Independence (CBI), revealing that the effects vary depending on the crisis type. Using data on financial crises and central bank independence, this analysis introduces an innovative approach that accounts for the duration and dynamics of crises. Banking crises are found to reduce independence, particularly in areas such as the formulation of monetary policy, the institution’s financial independence, and a shift away from focusing on price stability. In contrast, currency and debt crises generally enhance CBI. Currency crises primarily strengthen independence in monetary policy formulation, the institution’s financial independence, reporting responsibilities, and restrictions on lending to the government. Debt crises, on the other hand, increase reporting responsibilities, reinforce the central bank’s focus on price stability, and introduce additional restrictions on government lending. These findings underscore the pivotal role of financial crises in reshaping central banks. Understanding how central banks adapt and respond to financial crises is crucial for explaining their current roles, the evolution of their mandates, and the reasons behind their growing independence and responsibilities over time.