Ciências e Tecnologia | Artigos em revistas internacionais / Papers in international journals
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- Direct crosstalk between adult human retinas as suggested by interocular transfer of neurovascular coupling through photic stimulationPublication . Jordão, João; Figueira, João; Morgado, António Miguel; Guimarães, Pedro; Serranho, Pedro; Castro-Farías, Daniela; DeBuc, Delia Cabrera; Castelo-Branco, Miguel; Paques, Michel; Bernardes, RuiCrosstalk mechanisms between retinas were never documented in humans despite being documented for several other species, including non-human primates. Results of the first-in-human study that documents the crosstalk between retinas by measuring the vascular response in one retina to the photic stimulation of the contralateral eye in health and disease are reported herein. A stimulation apparatus was developed and integrated into an adaptive-optics fundus camera to image 32 healthy control (HC) subjects and 20 type 1 diabetes mellitus (DM) patients. Ipsilateral and contralateral neurovascular coupling effects were documented, and criteria were established to consider an actual response and find positive and negative responses. Ten (31.2%) and two (6.2%) subjects of the HC group presented contralateral positive and negative responses, respectively, and three (15.0%) positive and four (20.0%) negative responses were found for the DM group. Also, statistically significant differences in the ipsilateral (p < 0.001) and contralateral (p = 0.027) responses were found for the HC group, rejecting the null (non-response) hypothesis. This finding raises the need to revisit the current knowledge of neurovascular coupling mechanisms and the association between its dysregulation and neurological disorders. Further studies involving distinct populations and imaging centers are necessary to validate the findings herein.
- Early retinal changes in type 2 diabetes detected by texture-based OCT analysis: potential approach for subclinical diabetic retinopathy diagnosisPublication . Oliveira, Sara; Guimarães, Pedro; Roque-Rosado, Ângelo; Campos, Elisa Julião; Serranho, Pedro; Matafome, Paulo; Bernardes, Rui; Ambrósio, António FranciscoBackground: Diabetic retinopathy (DR) is often diagnosed many years after diabetes onset, highlighting the need for early diagnosis. The current study aimed to assess whether texture analysis of computed optical coherence tomography (OCT) retinal images can identify (very) early retinal changes. We previously reported retinal texture changes in a type 1 diabetes animal model. This study extends this approach to a type 2 diabetes model exhibiting subtler, more gradually developing retinal alterations to further explore its potential for detecting texture changes when DR-related retinal alterations are minor, strengthening its promising value. Methods: OCT scans and electroretinograms were acquired at baseline and 4, 8, and 12 weeks after initiating the diabetes induction protocol. Automated OCT segmentation, retinal thickness computation, and texture analysis were performed. Blood-retinal barrier permeability, glial reactivity, neuroinflammation, and nitrosative stress were assessed. Results: Retinal texture was affected in the inner plexiform layer and inner/outer photoreceptor segments. At weeks 8 and 12, autocorrelation, cluster prominence, correlation, homogeneity, information measure of correlation II, inverse difference moment normalised, inverse difference normalised, and sum average texture metrics significantly increased/decreased. Importantly, seven of these metrics were also altered in our previous study with type 1 diabetic animals. Type 2 diabetic retinas presented subtle thinning and impaired function, along with a slight reduction in tight junction proteins immunoreactivity, without affecting the blood-retinal barrier. Conclusions: The findings from this study indicate that texture analysis can identify subtle retinal changes during early, clinically silent stages of disease, when biological alterations remain minimal. This highlights its potential utility for the early diagnosis of diabetic retinopathy, though further clinical validation is needed.
- Impact of a master data management framework to trigger data governance maturity: a systematic literature reviewPublication . Guerreiro, Leonardo; Martins, José; Bernardo, Maria do Rosário ; São Mamede, Henrique; Branco, FredericoData governance plays a crucial role for organizations aiming to improve data quality, security, and compliance, yet research reveals ongoing challenges in implementation, maturity, and the practical effectiveness of current frameworks. Despite the availability of numerous concepts, models, and assessments, their actual impact and relevance remain fragmented and insufficiently explored. This Systematic Literature Review (SLR) investigates how data governance frameworks influence maturity and identifies the factors that drive their effectiveness. Through the synthesis of existing research, the review aims to clarify the relationship between governance frameworks and maturity levels, highlight operational benefits, and examine implementation challenges, ultimately contributing to both academic understanding and practical advancements in data governance. Analyzing the most relevant studies, the review seeks to uncover the main governance mechanisms, frameworks, and trends shaping this field, with a central question in focus: How can a structured master data management framework improve data governance maturity?.
- "The implementation of public chatbots to raise awareness of computer crime"Publication . Pimentel, Luis; Bernardo, Maria do Rosário ; Rocha, TâniaRecent technological advancements have increased computer crime, requiring public authorities to implement structured mitigation strategies. While initiatives exist to improve digital literacy on device security, they must also address the complexities of computer crime. Using Design Science Research, this study investigated the applicability of chatbots to raise awareness of computer crime in a public administration setting. A systematic literature review highlighted the issue’s relevance and identified knowledge gaps. A scoping review gathered concepts, methodologies, technologies, architectures, and tools for developing and evaluating an effective chatbot. The design and development phase included a detailed proposal for a sophisticated chatbot architecture. During the demonstration and evaluation phases, the utility of the chatbot was tested in the domain of conversational flow efficiency and usability. The study’s primary results and contributions are to assess the chatbot’s effectiveness in raising awareness of computer crime on public websites. Future work should focus on implementing the chatbot in the actual context of public administration, proposing a network of specialized conversational assistants, and improving public service interoperability to enhance computer crime awareness.
- Assessment of recreational boat anglers’ practices and perceptions in the Faial-Pico Channel marine protected area, AzoresPublication . Silva, Cliff; Seixas, SóniaThe Faial-Pico Channel Marine Protected Area (MPA), located in the Azores, Portugal, encompasses approximately 240 km² and is divided into two main zones: Faial and Pico. Unlike the broader regulations across mainland Portugal, the unique licensing requirements in the Azores only mandate boat owners to obtain licenses. This study aims to fill the existing research gap on recreational boat anglers in the Faial-Pico Channel MPA by employing face-to-face survey interviews with local boat anglers to understand their fishing practices, target species, and perceptions regarding marine resource management. Results from experienced recreational boat anglers indicate a predominant fishing duration of 11 to 30 days per year, with fishing efforts primarily targeting species such as forkbeard and blackspot seabream. The estimated annual capture is enormous, comprising a significant portion of the total fishing yield on Faial Island. Most boat anglers support specific conservation measures such as minimum length regulations and closed seasons, though there are varied opinions on the broader impacts of recreational fishing. Boat anglers largely attribute the decline in certain fish stocks to commercial overfishing. While the existing restrictions in Monte da Guia are accepted, proposals for additional MPAs face resistance. This study underscores the need for more comprehensive management strategies, such as improving communication between stakeholders and employing a licensing system to regulate fishing activities better and conserve marine biodiversity in the MPA.
- A machine learning framework for uplift modeling through customer segmentationPublication . Pinheiro, Paulo; Cavique, LuísIn uplift modeling, the goal is to identify high-value customers based on persuadable customers, those who make a purchase only if contacted. To achieve this, uplift modeling combines machine learning techniques with causal inference, allowing businesses to refine their customer targeting strategies and focus efforts where they are most profitable. This study proposes a practical and reproducible two-phase procedure for identifying highvalue customers. In the first phase, customers are segmented using decision trees, which offer a transparent and data-driven approach to grouping individuals with similar characteristics. This segmentation lays the groundwork for a meaningful interpretation of customer behavior. In the second phase, uplift is calculated for each customer segment by comparing the outcomes of the treatment and control groups. This enables the identification of customer groups with the highest uplift. A real-world use case further illustrates the value and applicability of the proposed method. To validate model performance, the procedure employs established metrics such as the Qini index and Cohen’s kappa, which provide insights into both the effectiveness and reliability of the uplift estimates. This work presents a decoupled procedure for uplift modeling that leverages well-established libraries, fostering transparency and a clear understanding of the analytical process. A key contribution to uplift modeling and causal inference is the use of decision trees for stratification, which enables the creation of meaningful segments and their evaluation through the average treatment effect. By integrating theory with practical implementation, this work offers a comprehensive framework for uplift modeling that bridges academic rigor and business usability.
- The reproductive ecology of Loligo squids (Cephalopoda: Myopsida) in Lusitanian zoogeographical provincePublication . Laptikhovsky, Vladimir; Moreno, Ana; Oesterwind, Daniel; Perales-Raya, C.; Pierce, Graham; Robin, J.-P.; Sobrino, Ignacio; Valls, M.; Villanueva, R.; Allen, A.; Abad, E.; Bello, G.; Bobowski, B.; Fernández-Álvarez, F.; Cabanellas-Reboredo, M.; González, Á.; Hernández-Urcera, J.; Krstulović-Šifner, S.; Lefkaditou, E.; MacLeod, E.; Valeiras , J.; Onsoy, B.; Pereira, João; Salman, A.; Seixas, Sónia; Power, A. M.Analysis of the temporal and spatial distribution of 686 records of egg masses and egg mass groups from (i) recreational divers and posted in the various public media, (ii) scientific survey data collected during research programs and (iii) publications in peer-reviewed literature plus published and unpublished information on the seasonality of the occurrence of mature females, demonstrated that the reproduction of Loligo squids occurs throughout the Lusitanian zoogeographical province all year round with varying seasonal peaks. This may be due to high phenotypic plasticity, with the life cycle adapting to local conditions, or the existence of small discrete stock units related to individual water features. In warmer and relatively productive waters the spawning peak is more extended, and percentage of mature females in catches is lower In the Mediterranean the peak of occur rence of both mature females and spawned eggs gradually shifts to earlier dates from the west to the east, which is consistent with respective changes of the earlier peak of productivity. There is little or no gap between peak of occurrence of mature females and peak of the egg mass records. Spawning grounds of L. vulgaris extend in the Mediterranean area much deeper than thought before and they extend from 3 m to 550 m. Egg masses were reported by recreational scuba divers from deeper locations in the central Mediterranean than in other areas. Loligo forbesii egg masses were found between 170 and 720 m.
- Mitigating false negatives in imbalanced datasets: an ensemble approachPublication . Cavique, Luís; Vasconcelos, MarceloImbalanced datasets present a challenge in machine learning, especially in binary classification scenarios where one class significantly outweighs the other. This imbalance often leads to models favoring the majority class, resulting in inadequate predictions for the minority class, specifically in false negatives. In response to this issue, this work introduces the MinFNR ensemble algorithm, designed to minimize False Negative Rates (FNR) in imbalanced datasets. The new approach strategically combines data-level, algorithmic-level, and hybrid-level approaches to enhance overall predictive capabilities while minimizing computational resources using the Set Covering Problem (SCP) formulation. Through a comprehensive evaluation of diverse datasets, MinFNR consistently outperforms individual algorithms, showing its potential for applications where the cost of false negatives is substantial, such as fraud detection and medical diagnosis. This work also contributes to ongoing efforts to improve the reliability and effectiveness of machine learning algorithms in real imbalanced scenarios.
- A data science maturity model applied to students' modelingPublication . Cavique, Luís; Pombalinho, Paulo; Correia, LuísMaturity models define a series of levels, each representing an increased complexity in information systems. Data Science appears in the Business Intelligence (BI) and Business Analytics (BA) literature. This work applies the _IABE maturity model, which includes two additional levels: Data Engineering (DE) at the bottom and Business Experimentation (BE) at the top. This study uses the _IABE model for students' modeling in the ModEst project. For this purpose, the Public Administration organism is the Directorate-General for Statistics of Education and Science (DGEEC) of the Portuguese Education Ministry. DGEEC provided vast data on two million students per year in the Portuguese school system, from pre-scholar to doctoral programs. This work presents the comprehensible _IABE maturity model to extract new knowledge from the DGEEC dataset. The method applied is _IABE, where after the DE level, wh-questions are formulated and answered with the most appropriate techniques at each maturity level. This work's novelty is applying the maturity model _IABE to a unique dataset for the first time. Wh-questions are stated at the BI level using data summarization; at the BA level, predictive models are performed, and counterfactual approaches are presented at the BE level.
- Implications of causality in artificial intelligencePublication . Cavique, LuísOver the last decade, investment in artificial intelligence (AI) has grown significantly, driven by technology companies and the demand for PhDs in AI. However, new challenges have emerged, such as the ‘black box’ and bias in AI models. Several approaches have been developed to reduce these problems. Responsible AI focuses on the ethical development of AI systems, considering social impact. Fair AI seeks to identify and correct algorithm biases, promoting equitable decisions. Explainable AI aims to create transparent models that allow users to interpret results. Finally, Causal AI emphasizes identifying cause-andeffect relationships and plays a crucial role in creating more robust and reliable systems, thereby promoting fairness and transparency in AI development. Responsible, Fair, and Explainable AI has several weaknesses. However, Causal AI is the approach with the slightest criticism, offering reassurance about the ethical development of AI.