Abstract

Abstract
Cyber-security is the practice of protecting computing systems and networks from digital attacks, which are a rising concern in the Information Age. With the growing pace at which new attacks are developed, conventional signature based attack detection methods are often not enough, and machine learning poses as a potential solution. Adversarial machine learning is a research area that examines both the generation and detection of adversarial examples, which are inputs specially crafted to deceive classifiers, and has been extensively studied specifically in the area of image recognition, where minor modifications are performed on images that cause a classifier to produce incorrect predictions. However, in other fields, such as intrusion and malware detection, the exploration of such methods is still growing. The aim of this survey is to explore works that apply adversarial machine learning concepts to intrusion and malware detection scenarios. We concluded that a wide variety of attacks were tested and proven effective in malware and intrusion detection, although their practicality was not tested in intrusion scenarios. Adversarial defenses were substantially less explored, although their effectiveness was also proven at resisting adversarial attacks. We also concluded that, contrarily to malware scenarios, the variety of datasets in intrusion scenarios is still very small, with the most used dataset being greatly outdated.

Abstract
e13070 Background: Bone is one of the main sites of breast cancer metastasis. Staging of this kind of disease spread can be performed in locally advanced cases with PET-CT in conjunction with Bone Scintigraphy. The purpose of this work is to compare the efficiency of bone metastasis detection between PET-CT and bone scintigraphy. Methods: Prospective analysis of locally advanced breast cancer patients treated in a Comprehensive Cancer Center between 2014 and 2019 that performed PET-CT and Bone Scintigraphy in the staging. Interval between the two exams could not exceed 2 months. Clinical and pathological characteristics of the disease were collected from electronic files and independently clinical images reports were considered to evaluate the ability of each imaging modalities to identify bone disease. In discrepancy cases a re-analysis of the images by two independent nuclear physicians was performed to validate the findings. Results: We analyzed 204 cases. The majority of them had ductal carcinomas (72.5%), cT2/3 (70%), cN1/2(61.8%) and G2/3 (94.6%), luminal B- like, HER2 positive disease (49.2%). In this cohort, bone metastasis was documented in 52 (25.5%) patients. PET-CT presented 97.0% of accuracy, surpassing the 94.1% presented by Bone Scintigraphy. The latter failed to correctly detect bone metastasis in 11 (5.4%) patients and only outperformed PET-CT in 3 (1.5%) patients. The main difference between the two modalities was the non-detection of cranium lesions in PET-CT images. Conclusions: PET-CT showed higher efficiency in bone metastasis detection than Bone Scintigraphy, probably because it detects lytic lesions. The non-detection of cranium ones can be harmful and so modifications in the image acquisition are required to improve the quality of PET-CT, avoiding other exams in bone staging.

Abstract
This chapter is based on consumer behavior theories and analyses consumers' perspectives about camping as a tourism alternative. It explores motivations and several relevant factors that influence the attitudes and behaviors of tourists regarding camping activities. The methodology was qualitative and used focus groups as a data collection tool. A content and thematic analysis was adopted as data mining technique. Results provide empirical support to the influence of subjective norms, relevant others' preference for camping, and sustainable consumer profile on attitudes toward camping which influence camping intention. Moreover, camping intention, motivations, relevant others' preference for camping, perceived control, and past experience affect camping behavior. Overall, this chapter shows that consumer behavior theories and models provide very interesting cues on campers' decision process, offering alternative and complementing views to the extant literature, namely to the studies using the popular push-pull approach.

Abstract
This paper aims to study the perceptions of Vocational Education and Training (VET) students and VET teachers about the image of vocational education in Portugal and the contributions of VET to the achievement of the goals set in the 2030 Agenda. For this purpose, a qualitative study was conducted in Portugal in 2020 with a sample of 5 former VET students and 12 VET teachers. The objective was for participants to provide their views, experiences, and opinions on the inclusiveness and quality of VET education at the secondary level and how it may contribute to students’ lifelong opportunities, employability, and social inequality reduction. Various perspectives were offered, including divergent views between teachers and students. Topics such as equity, stigma, social status, employability and empowerment resulting from professional recognition, namely due to continuing studies at a higher level, were also discussed. Overall, this study provides valuable insights on the possible roles of VET in what concerns the 2030 Agenda, demonstrating that this topic deserves urgent attention from researchers.

Abstract
Despite the growing popularity of Vocational Education and Training (VET), which is mainly oriented towards labour market inclusion, literature shows that there is still stigmatization and association of those programmes with lower quality training offers when compared to the so-called general secondary education. The main aim of this article is to shed light on the differences in students' sociodemographic profiles between the two education alternatives. It adopts a quantitative approach, exploring secondary data collected by national (e.g., Ministry of Education) and international (e.g., OECD) organizations regarding secondary education students in Portugal. Results confirm that students in VET secondary education have a different sociodemographic profile, namely in terms of income, parents' academic qualifications and professional activities, thus presenting a clear lower social status than students in general secondary education. Indeed, VET is more common in Portuguese secondary schools with a student population originating from more disadvantaged socioeconomic backgrounds. This study also highlights the limitations of the available secondary data, suggesting a set of variables and hypotheses built on contributions from extant literature that may enable a better understanding of the reasons behind the differences in students' profiles. Implications for schools and decision makers, as well as suggestions for future research, are also presented.