Validation and adaptation of the Physical Activity Enjoyment Scale (PACES) in fitness group exercisers

Background: Recently, Mullen et al. (2011) presented an 8-item version of the Physical Activity Enjoyment Scale (PACES) providing a valid instrument for assessing enjoyment in physical activity. The present paper investigated the psychometric properties of a Portuguese adaptation of PACES.Methods: After a process of back-to-back translation into Portuguese, 395 members of fitness centers who ranged in age from 18 to 66 years (31.11 ± 8.90, mean ± SD) completed the translated version of the PACES. On average, participants had 3.2 years of experience in fitness group classes and practiced for approximately 3.3 times per week.Results: An initial exploratory factor analysis (n = 139) revealed a unidimensional structure with factor loadings ranging from 0.79 to 0.89. Results also showed acceptable internal consistency. A confirmatory factor analysis in an independent sample (n = 256) provided additional support for the unidimensional structure of the questionnaire. In addition, moderate positive correlations between enjoyment and intrinsic and identified regulation, and moderate negative correlations between enjoyment and external and amotivation demonstrate the convergent validity of the instrument. Finally, measurement invariance between two independent samples was also found.Conclusion: The 8-item Portuguese version of PACES is a valid and reliable instrument for measuring enjoyment of physical activity in Portuguese adult's fitness exercisers, therefore suitable to use as a measure of affect in exercise adherence interventions studies

La calificación de las entidades extranjeras como transparentes o no transparentes en los impuestos sobre la renta

En este trabajo se analiza el método de calificación de la legislación española para determinar si una entidad extranjera debe ser tratada en España como transparente o no transparente. Aunque la normativa parece establecer un sistema de calificación basado en el método de la comparabilidad, en la práctica las consultas de la Dirección General de Tributos están aplicando el método basado en el régimen fiscal de la entidad en el país de origenThis article analyzes the criterion envisaged under Spanish law to classify foreign entities as transparent or opaque. Although the wording of the Spanish statutory rule seems to establish a resemblance test, the rulings of the Spanish General Directorate for Taxation reveal that the classifi cation is mainly based on how the entity is treated for tax purposes in its home countryEste trabajo se ha realizado en el marco del proyecto DER2012-31931, financiado por el Ministerio de Economía y Competitivida

Circular economy for healthy cities

Os locais onde as pessoas vivem e trabalham, consomem e desperdiçam, têm um papel fundamental na transição para a economia circular. A crise da covid-19 destacou o caráter insustentável de determinadas tendências ambientais e sociais, e levou a reconsiderar os atuais padrões de produção e consumo, motivando a recuperação verde. Um dos aspetos mais relevantes prende-se com a governação e o território, em especial as zonas urbanas onde viverá mais de 80 por cento da população em 2050. Novas fontes de energia, tecnologias mais limpas e aumentar a resiliência urbana através das funções e serviços dos ecossistemas, são apenas exemplos de como melhorar o ambiente, combater as alterações climáticas, aumentar a circularidade da economia e promover a saúde humana. Usando o exemplo da cidade do Porto, os resultados contribuíram para o conhecimento da estrutura urbana, podendo ser de grande importância para os decisores políticos no combate aos impactos das alterações climáticas nas cidades.The places where people live and work, consume and throw away, play a key role in the transi-tion to the circular economy. The covid-19 cri-sis highlighted the unsustainable character of certain environmental and social trends, and led to a reconsideration of current production and consumption patterns, motivating green recovery. One of the most relevant aspects is related to governance and territory, especially urban zones where more than 80 percent of the population will live in 2050. New energy sources, cleaner technologies and the increase of urban resilience through ecosystem services and func-tions, are just examples of how to improve the environment, combat climate change, enlarge the circularity of the economy and promote human health. Using the example of the city of Porto, the results contributed to the urban structure knowledge and could be of great importance for policy makers in combating the impacts of climate change on cities.publishe

Applications in security and evasions in machine learning : a survey

In recent years, machine learning (ML) has become an important part to yield security and privacy in various applications. ML is used to address serious issues such as real-time attack detection, data leakage vulnerability assessments and many more. ML extensively supports the demanding requirements of the current scenario of security and privacy across a range of areas such as real-time decision-making, big data processing, reduced cycle time for learning, cost-efficiency and error-free processing. Therefore, in this paper, we review the state of the art approaches where ML is applicable more effectively to fulfill current real-world requirements in security. We examine different security applications' perspectives where ML models play an essential role and compare, with different possible dimensions, their accuracy results. By analyzing ML algorithms in security application it provides a blueprint for an interdisciplinary research area. Even with the use of current sophisticated technology and tools, attackers can evade the ML models by committing adversarial attacks. Therefore, requirements rise to assess the vulnerability in the ML models to cope up with the adversarial attacks at the time of development. Accordingly, as a supplement to this point, we also analyze the different types of adversarial attacks on the ML models. To give proper visualization of security properties, we have represented the threat model and defense strategies against adversarial attack methods. Moreover, we illustrate the adversarial attacks based on the attackers' knowledge about the model and addressed the point of the model at which possible attacks may be committed. Finally, we also investigate different types of properties of the adversarial attacks

ICEER2019@Aveiro: Energy and environment - challenges towards circular economy

The 6th edition of the International Conference on Energy and Environment Research, ICEER 2019, took place in the end of July 2019, at the University of Aveiro, Portugal. With most of the participants coming from academia, and a few from the professional field, ICEER series is still growing and attracting increased interest. Energy production, distribution and use are fundamental for the Sustainable Development of nations, showing a clear link between the energy and environment issues. Nevertheless, these matters are frequently dealt with separately, reflecting the way they are taught, and causing strong negative impacts, and hindering progress. With a growing trend in circular economy models applied to common goods production and commercialization, ICEER 2019 had as focus theme the challenges posed by energy and environment research in a circular economy-based model. This paper presents the main achievements and conclusions of ICEER 2019 participants, through their research in the fields of energy and environment, including a brief analysis of the current requirements of Education on Sustainable Development applied to the modern technological curricula.info:eu-repo/semantics/publishedVersio

Endeavouring to be in the good books : awarding DTN network use for acknowledging the reception of bundles

This paper describes an incentive scheme for promoting the cooperation, and, therefore, avoiding selfish behaviours, in Delay Tolerant Networks (DTN) by rewarding participant nodes with cryptographic keys that will be required for sending bundles. DTN are normally sparse, and there are few opportunistic contacts, so forwarding of other's bundles can be left out. Moreover, it is difficult to determine the responsible nodes in case of bundle loss. The mechanism proposed in this paper contributes to both problems at the same time. On one hand, cryptographic receipts are generated using time-limited Identity Based Cryptography (IBC) keys to keep track of bundle transmissions. On the other hand, these receipts are used to reward altruistic behaviour by providing newer IBC keys. Finally, these nodes need these IBC keys to send their own bundles. When all nodes behave in a cooperative way, this incentive scheme works as a virtuous circle and achieves a Nash equilibrium, improving very much the network performance in terms of latency. The scheme is not difficult to implement, and it can use an already existing IBC infrastructure used for other purposes in a DTN

Information System for Supporting Location-based Routing Protocols

This article presents an information system for location-based routing protocols that does not compromise the privacy of the involved nodes. This information system provides a representational model of the most frequented locations of a node, this most frequented zone is called its habitat, and a protocol to compare these habitats among nodes given a target location of interest. Then, the protocol can determine which of the neighbors of a node is nearer or farther from this target location and provides this information to the underlying routing protocol. As it is designed for DTNs, the protocol does not require a trusted third party, instead, it implements a secure multi-party computation based on homomorphic encryption. The protocol is demonstrated to be secure against passive and active adversaries.This work was partly supported by grant TIN2010-15764 from the Ministerio de Ciencia e Innovación of Spain and by grant 2014SGR-691 from Generalitat de Catalunya