This work addresses the challenge of capturing the complexities of legal knowledge by proposing a multi-layered embedding-based retrieval method for legal and legislative texts. Creating embeddings not only for individual articles but also for their components (paragraphs, clauses) and structural groupings (books, titles, chapters, etc), we seek to capture the subtleties of legal information through the use of dense vectors of embeddings, representing it at varying levels of granularity. Our method meets various information needs by allowing the Retrieval Augmented Generation system to provide accurate responses, whether for specific segments or entire sections, tailored to the user's query. We explore the concepts of aboutness, semantic chunking, and inherent hierarchy within legal texts, arguing that this method enhances the legal information retrieval. Despite the focus being on Brazil's legislative methods and the Brazilian Constitution, which follow a civil law tradition, our findings should in principle be applicable across different legal systems, including those adhering to common law traditions. Furthermore, the principles of the proposed method extend beyond the legal domain, offering valuable insights for organizing and retrieving information in any field characterized by information encoded in hierarchical text.

In the absence of abundant reliable annotations for challenging tasks and contexts, how can we expand the frontier of LLM capabilities with potentially wrong answers? We focus on two research questions: (1) Can LLMs generate reliable preferences among wrong options? And if so, (2) Would alignment with such wrong-over-wrong preferences be helpful? We employ methods based on self-consistency, token probabilities, and LLM-as-a-judge to elicit wrong-over-wrong preferences, and fine-tune language models with preference optimization approaches using these synthesized preferences. Extensive experiments with seven LLMs and eight datasets demonstrate that (1) LLMs do have preliminary capability in distinguishing various shades of wrong, achieving up to 20.9% higher performance than random guess; (2) Alignment with wrong-over-wrong preferences helps LLMs to produce less wrong and sometimes even outright correct answers, while overall improving model calibration.

Brazil's national data protection authority has ordered Meta to halt the use of data originating from the country to train its AI models. Meta's current privacy policy enables the company to use data from its platforms, including Facebook, Instagram, and WhatsApp to train its artificial intelligence models. However, that practice will no longer be permitted in Brazil after its national data protection authority gave the company five days to change its policy on Tuesday. Brazil said the company will need to confirm it has stopped using the data or face a daily non-compliance fine of 50,000 Brazilian Reals (almost 9000), citing "the imminent risk of serious and irreparable or difficult-to-repair damage to the fundamental rights of the affected data subjects." Meta said it was "disappointed" with the Brazilian authority's decision, saying it was a "step backward for innovation."

Prime Minister Fumio Kishida will visit France, Brazil and Paraguay from Wednesday through May 6, the government said Friday. In Paris on Thursday, Kishida plans to give a keynote speech at a ministerial council meeting of the OECD and meet with French President Emmanuel Macron. The speech will reflect Kishida's intention to lead discussions to resolve socio-economic challenges for the international community, Chief Cabinet Secretary Yoshimasa Hayashi said at a news conference. Kishida is also set to deliver speeches at OECD events themed on generative artificial intelligence and on cooperation with Southeast Asia. In Brasilia on May 3, Kishida will meet with President Luiz Inacio Lula da Silva, this year's chair of the Group of 20 major economies, and hold a joint news conference.

Femicide refers to the killing of a female victim, often perpetrated by an intimate partner or family member, and is also associated with gender-based violence. Studies have shown that there is a pattern of escalating violence leading up to these killings, highlighting the potential for prevention if the level of danger to the victim can be assessed. Machine learning offers a promising approach to address this challenge by predicting risk levels based on textual descriptions of the violence. In this study, we employed the Long Short Term Memory (LSTM) technique to identify patterns of behavior in Brazilian police reports preceding femicides. Our first objective was to classify the content of these reports as indicating either a lower or higher risk of the victim being murdered, achieving an accuracy of 66%. In the second approach, we developed a model to predict the next action a victim might experience within a sequence of patterned events. Both approaches contribute to the understanding and assessment of the risks associated with domestic violence, providing authorities with valuable insights to protect women and prevent situations from escalating.

In today's digital age, images have emerged as powerful tools for politicians to engage with their voters on social media platforms. Visual content possesses a unique emotional appeal that often leads to increased user engagement. However, research on visual communication remains relatively limited, particularly in the Global South. This study aims to bridge this gap by employing a combination of computational methods and qualitative approach to investigate the visual communication strategies employed in a dataset of 11,263 Instagram posts by 19 Brazilian presidential candidates in 2018 and 2022 national elections. Through two studies, we observed consistent patterns across these candidates on their use of visual political communication. Notably, we identify a prevalence of celebratory and positively toned images. They also exhibit a strong sense of personalization, portraying candidates connected with their voters on a more emotional level. We note a substantial presence of screenshots from news websites and other social media platforms. Furthermore, text-edited images with portrayals emerge as a prominent feature. In light of these results, we engage in a discussion regarding the implications for the broader field of visual political communication. This article serves as a testament to the pivotal role that Instagram has played in shaping the narrative of two fiercely polarized Brazilian elections, casting a revealing light on the ever-evolving dynamics of visual political communication in the digital age. Finally, we propose avenues for future research in the realm of visual political communication. Introduction In the ever-evolving arena of election campaigns, candidates rely heavily on the media as their megaphone to amplify their messages to the masses. Over the years, the landscape of political communication has undergone a profound transformation. This transformation has been driven by the rise of online social media platforms, which have emerged as indispensable tools for candidates in their quest to gauge public sentiment and rally support from the electorate (Boulianne & Olof Larsson, 2023; Farkas & Bene, 2021). The significance of this transformation has been further accentuated by the global ascent of populist leaders, spanning diverse nations, who have wholeheartedly embraced social media as their primary mode of communication (Bernardi & Costa, 2020; Novoselova, 2020).

Training machine learning models for predicting stock market share prices is an active area of research since the automatization of trading such papers was available in real time. While most of the work in this field of research is done by training Neural networks based on past prices of stock shares, in this work, we use iFeel 2.0 platform to extract 19 sentiment features from posts obtained from microblog platform Twitter that mention the company Petrobras. Then, we used those features to train XBoot models to predict future stock prices for the referred company. Later, we simulated the trading of Petrobras' shares based on the model's outputs and determined the gain of R$88,82 (net) in a 250-day period when compared to a 100 random models' average performance.

Video segmentation consists of a frame-by-frame selection process of meaningful areas related to foreground moving objects. Some applications include traffic monitoring, human tracking, action recognition, efficient video surveillance, and anomaly detection. In these applications, it is not rare to face challenges such as abrupt changes in weather conditions, illumination issues, shadows, subtle dynamic background motions, and also camouflage effects. In this work, we address such shortcomings by proposing a novel deep learning video segmentation approach that incorporates residual information into the foreground detection learning process. The main goal is to provide a method capable of generating an accurate foreground detection given a grayscale video. Experiments conducted on the Change Detection 2014 and on the private dataset PetrobrasROUTES from Petrobras support the effectiveness of the proposed approach concerning some state-of-the-art video segmentation techniques, with overall F-measures of $\mathbf{0.9535}$ and $\mathbf{0.9636}$ in the Change Detection 2014 and PetrobrasROUTES datasets, respectively. Such a result places the proposed technique amongst the top 3 state-of-the-art video segmentation methods, besides comprising approximately seven times less parameters than its top one counterpart.

Every other day, my WhatsApp bursts with messages from friends in Brazil and abroad expressing equal parts of excitement and apprehension as Sunday's Brazilian presidential elections approach. On Wednesday, my best friend who lives in the country's capital, Brasília, texted to say she was scared of wearing red clothes to go vote this weekend because red is the color associated with the Worker's Party of former President Luiz Inácio Lula da Silva. Lula, the current front-runner, has a real, if slim, chance to beat far-right incumbent President Jair Bolsonaro in the first round by getting more than 50 percent of valid votes. "The mood is terrible," she wrote, later adding that in the last 48 hours, four instances of political violence had been recorded across the country. My friend's worries are justified.

Brazil's House of Representatives has approved a bill that sets out legal regulations for artificial intelligence (AI). Bill No. 21/20 outlines guidelines to develop and utilize AI in Brazil. The bill will regulate transparency regarding the use of AI in the public sector, promote the creation of AI for the public sector, and require the "adoption of regulatory instruments that promote innovation." AI can predict and make decisions when implemented into computer systems and machines. The innovation in society and the regulations that have been introduced have been welcomed by the author of the project, Deputy Eduardo Bismarck (PDT-CA). He stated that "the time is now to outline principles: rights and duties and responsibilities" to account for this innovation already integrated into reality.