Browsing by Issue Date, starting with "2024-11-15"
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- Machine learning-driven GLCM analysis of structural MRI for Alzheimer’s disease diagnosisPublication . Oliveira, Maria João; Ribeiro, Pedro; Rodrigues, Pedro MiguelBackground: Alzheimer’s disease (AD) is a progressive and irreversible neurodegenerative condition that increasingly impairs cognitive functions and daily activities. Given the incurable nature of AD and its profound impact on the elderly, early diagnosis (at the mild cognitive impairment (MCI) stage) and intervention are crucial, focusing on delaying disease progression and improving patients’ quality of life. Methods: This work aimed to develop an automatic sMRI-based method to detect AD in three different stages, namely healthy controls (CN), mild cognitive impairment (MCI), and AD itself. For such a purpose, brain sMRI images from the ADNI database were pre-processed, and a set of 22 texture statistical features from the sMRI gray-level co-occurrence matrix (GLCM) were extracted from various slices within different anatomical planes. Different combinations of features and planes were used to feed classical machine learning (cML) algorithms to analyze their discrimination power between the groups. Results: The cML algorithms achieved the following classification accuracy: 85.2% for AD vs. CN, 98.5% for AD vs. MCI, 95.1% for CN vs. MCI, and 87.1% for all vs. all. Conclusions: For the pair AD vs. MCI, the proposed model outperformed state-of-the-art imaging source studies by 0.1% and non-imaging source studies by 4.6%. These results are particularly significant in the field of AD classification, opening the door to more efficient early diagnosis in real-world settings since MCI is considered a precursor to AD.
- SLIPPERY discourses of intertwined crises: migration and Covid-19 pandemic in a postcolonial nationPublication . Minga, EsterThe outbreak of a pandemic inevitably links with migration as containment measures usually involve the closure of borders. In the Portuguese context, mediated discourses of these intertwined crises were varied and multifaceted, reflecting the country’s postcolonial peculiarity as both a provider of emigrants and host country to distinct fluxes of migrants. Through a qualitative analysis of selected items published in Portuguese newspapers Expresso, Diário de Notícias, and Correio da Manhã, I will show how similar issues involving Portuguese emigrants and distinct groups of migrants have been differently framed in news items related to the Covid-19 pandemic. The aim is to discuss how this unstable coverage speaks to, and collides with, the deep social imaginary of Portuguese emigration and the widespread idea of a Lusophone space characterized by the harmonious conviviality of different people. I argue that the fragmented frames represent a symptom of crisis themselves, revealing unsettled discourses and alternating anxieties.
- All you need is [somebody’s] love “third-party reproduction” and the existential density of biological affinityPublication . Madureira, Diogo Morais SarmentoWhat is the true significance of biological kinship? During the last decades, it seemed to be uncontroversial that abandoned and even adopted people feel the negative impact of biological parents’ absence throughout life in several ways (Miller et al. 2000; Keyes, Margaret A., Anu Sharma, Irene J Elkins, and William G. Iacono, Matt McGue. 2008. The Mental Health of US Adolescents Adopted in Infancy. Archive Pediatric Adolescense Medicine 162(5): 419–425.). However, in the case of people conceived via “third-party reproduction”, especially in sperm donation, the disruption of the kinship network derived from natural bonds tends to be presented as something irrelevant. This article disputes that assumption, explores its relationship with a deconstructivist vision that presents kinship as a purely social construct and defends the personal and existential value of a person’s biological bonds with her parents. While analysing the anthropological shift inherent to the way some political discourses present the nuclear family and heterologous biotechnology, it proposes renewed philosophical attention on the significance of filiation and human affinity. This article argues for the density of genealogical ties and defends that the consecration of an individual “right to a child”, namely (but not exclusively) through the normalised access to sperm banks, is incompatible with the rights of the child, since it deprives people from knowing not only who but also how is their father.
- AI and decision-making under risk : a behavioural study exploring how large language models may affect our risk preferencesPublication . Seabra, Lucas Bagnari de; Almeida, Ana Filipa Martinho deThis dissertation investigates the role of AI, particularly Large Language Models, in influencing risk-taking behaviours in a decision-making context, hypothesizing a diffusion of responsibility in human-AI interactions. A Randomized-Control Trial was employed, with participants completing a risk elicitation task – the Bomb Risk Elicitation Task – across two sequential rounds. Participants were either assisted by an AI-powered chatbot during the task or placed in a control group without AI assistance. Measures such as Trust and Attitudes towards AI, and general risk aversion were collected, to serve as control variables. Participant’s locus of control was also measured to test the diffusion of responsibility hypothesis. A total of 138 participants completed an online experiment. Results indicate that AI assistance had a significant effect on participants’ risk preferences, particularly in the second round of the task. Notably, the outcome of the first round showed to be an important factor in this dynamic. Among those who did not have a successful outcome in the first round, participants in the control group exhibited greater risk aversion in the subsequent round, a pattern that was not observed in the AI-assisted group. Further analyses indicated that trust in AI and an external locus of control marginally moderated this effect, pointing to a diffusion of responsibility with the AI. Additional findings suggest the rational effect AI assistance had on participants. Particularly, the proportion of risk-neutral participants increased from 6% in the control group to 28% in the treatment group, indicating an approximation of rational decisionmaking with AI assistance. The findings suggest that AI assistance can alter risk preferences, potentially through mechanisms of increased confidence or diffusion of responsibility. This dissertation contributes to our understanding of human-AI interaction and highlights the need for further studies to disentangle these effects and explore their implications for decision-making in high-stakes environments.
- O impacto da inteligência artificial no seio da corporate governancePublication . Flórido, Diogo de Sousa; Antunes, José Augusto Quelhas Lima EngráciaA presente dissertação analisa a integração da Inteligência Artificial (IA) na corporate governance, destacando suas vantagens e riscos. A IA, com a sua capacidade superior de coleta, armazenamento e processamento de dados, quando combinada com machine learning, pode desenvolver-se autonomamente, tomando decisões com base no ambiente que a rodeia. Este avanço tecnológico gera especulações sobre o seu impacto nas empresas, especialmente no órgão de administração, onde as suas potencialidades são mais evidentes. Ao longo deste estudo vamo-nos debruçar sobre o significado de inteligência artificial e corporate governance, com o objetivo de estabelecermos os fundamentos que nos permitam refletir sobre a influência que a inteligência artificial terá no funcionamento e na organização societária. Neste contexto, o objetivo desta dissertação será, considerando as capacidades atuais e futuras da inteligência artificial, compreender de que formas esta tecnologia poderá influenciar a dinâmica societária, em especial o funcionamento do órgão de administração.