Abstract
Machine learning has been facing significant challenges over the last years, much of which stem from the new characteristics of machine learning problems, such as learning from streaming data or incorporating human feedback into existing datasets and models. In these dynamic scenarios, data change over time and models must adapt. However, new data do not necessarily mean new patterns. The main goal of this paper is to devise a method to predict a model's performance metrics before it is trained, in order to decide whether it is worth it to train it or not. That is, will the model hold significantly better results than the current one? To address this issue, we propose the use of meta-learning. Specifically, we evaluate two different meta-models, one built for a specific machine learning problem, and another built based on many different problems, meant to be a generic meta-model, applicable to virtually any problem. In this paper, we focus only on the prediction of the root mean square error (RMSE). Results show that it is possible to accurately predict the RMSE of future models, event in streaming scenarios. Moreover, results also show that it is possible to reduce the need for re-training models between 60% and 98%, depending on the problem and on the threshold used.

Abstract
Microsatellite Instability (MSI) is an important biomarker in cancer patients, showing a defective DNA mismatch repair system. Its detection allows the use of immunotherapy to treat cancer, an approach that is revolutionizing cancer treatment. MSI is especially relevant for three types of cancer: Colon Adenocarcinoma (COAD), Stomach Adenocarcinoma (STAD), and Uterus corpus endometrial cancer (UCEC). In this work, learning algorithms were employed to predict MSI using RNA-seq data from The Cancer Genome Atlas (TCGA) database, with a focus on the selection of the most informative genomic features. The Multi-Layer Perceptron (MLP) obtained the best score (AUC = 98.44%), showing that it is possible to exploit information from RNA-seq data to find relevant relationships with the instability levels of microsatellites (MS). The accurate prediction of MSI with transcription data from cancer patients will help with the correct determination of MSI status and adequate prescription of immunotherapy, creating more precise and personalized patient care. At the genetic level, the study revealed a high expression of genes related to cell regulation functions, and a low expression of genes responsible for Mismatch Repair functions, in patients with high instability.

Abstract
Despite the increasing importance of business angels (BAs) as crucial players in the growth of high-potential early-stage startups, their motivations are not fully understood. Many of the perceptions of BAs deviate significantly from more conventional views of conventional economic and financial models. To gain a comprehensive understanding of BAs' goals, qualitative techniques from marketing and consumer behaviour as additional lenses (including laddering and means-ends chains) were employed to allow currently active BAs to articulate their goals in ways that forced-choice, quantitative methods do not achieve. Additionally, to determine if entrepreneurs perceive BAs in the same way BAs see themselves, entrepreneurs were asked to provide their perspectives on why BAs choose to become angel investors, based on their experiences with BAs. The findings reveal that traditional financial viewpoints do not adequately capture the depth and driving force behind BAs' goals, while entrepreneurs appear to be overly influenced by conventional assumptions about these goals. The study also provides valuable insights into the relationships and hierarchy among BAs' goals, and on the relevance of each goal. The paper ends with reflections on the practical implications of this research for BAs, entrepreneurs and policymakers.

Abstract
The internet massification and e-commerce growth that have been driven by “millennials” and the coronavirus pandemic cannot remain indifferent to luxury brands. These brands have had to adapt to e-commerce and develop an online shopping experience which satisfies its customers, so that they repeat purchase. Therefore, the main objective of this research is to understand the main impacts of shopping experience on luxury brand websites on satisfaction and loyalty. A model which analyzes the relationship between the three constructs was developed and information was gathered through an online survey, from which resulted 356 valid answers. Through the analysis of data collected and using a structural equation model, using SmartPLS software, we realized that online shopping experience is positively related to satisfaction. Loyalty, in turn, is positively affected by brand satisfaction. This study makes an important contribution to luxury brands and to people in charge of marketing and online platforms selling luxury goods. It helps brands understand that enhancing online shopping experience can positively impact satisfaction and loyalty levels. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Abstract

Abstract
INTRODUÇÃO: De forma a contribuir para a diminuição da incidência e prevalência das doenças relacionadas com os hábitos alimentares, implementou-se o Projeto de Otimização das Dietas Escolares que pretende contribuir para uma oferta alimentar escolar alinhada com as premissas de uma alimentação saudável. OBJETIVOS: Comparar qualitativa e quantitativamente a oferta alimentar escolar referente à refeição do almoço considerando os modelos de gestão direta e concessionada. METODOLOGIA: Estudo observacional de desenho transversal. O Projeto de Otimização das Dietas Escolares, implementado em 34 escolas do ensino público do distrito de Viana do Castelo, tem como objetivo garantir a oferta de refeições variadas, normoenergéticas, nutricionalmente equilibradas e que garantam os critérios de higiene e segurança alimentar. Analisaram-se dados correspondentes a uma avaliação mensal de cada escola, entre 2014 e 2019. RESULTADOS: Os refeitórios com gestão direta cumpriram maior percentagem (82%), em mediana, de critérios qualitativos do Projeto de Otimização das Dietas Escolares, relativamente aos de gestão concessionada (p = 0,022). Todos os refeitórios com gestão direta cumpriram a periodicidade de oferta de peixe rico em ómega-3 (?3) exigida. Estes utilizaram uma maior quantidade de gordura e gordura saturada comparativamente aos de gestão concessionada (p = 0,030 e 0,040, respetivamente). O contrário ocorreu na oferta de fibra (p = 0,016). CONCLUSÕES: Considerando a avaliação qualitativa, os refeitórios com gestão direta cumpriram melhor os critérios do Projeto de Otimização das Dietas Escolares e ofereceram peixe rico em ?3 com maior periodicidade, relativamente aos com gestão concessionada. Quantitativamente, os refeitórios com gestão concessionada ofereceram refeições com menor quantidade de gordura e gordura saturada e maior quantidade de fibra.