Worldwide organic food consumption has registered a consistent rise in recent years. Despite the relevant body of literature on the topic, it is necessary to further understand the antecedents of purchase intention. This article aims to identify the factors that influence the consumer’s intention to purchase organic food. It extends the theory of planned behavior model by including environmental concerns, health concerns, and perceived quality as determinants of attitude toward organic food products. Additionally, it considers the effect of product availability on consumers’ perceived behavioral control. This article includes a quantitative study that was conducted in Portugal in 2020 (n = 206). Structural equation modeling was used to test the proposed set of research hypotheses. In line with extant literature, this study confirmed that attitude toward organic food is the main determinant of purchase intention. Additionally, it demonstrates that health concerns and perceived quality have a significant impact on attitude toward organic food. The impact of environmental concerns on attitude was not confirmed by this study. Based on these findings, it is recommended that managers stress health benefits and quality of organic food in order to foster positive attitudes and consequently leverage purchase intention.

We introduce a set of tools and techniques for increasing the resilience and trustworthiness of identity providers (IdPs) based on OpenID. To this purpose we propose an architecture of specialized components capable of fulfilling the essential requirements for ensuring high availability, integrity and higher confidentiality guarantees for sensitive data and operations. Additionally, we also discuss how trusted components (e.g., TPMs, smart cards) can be used to provide remote attestation on the client and server side, i.e., how to measure the trustworthiness of the system. The proposed solution outperforms related work in different aspects, such as countermeasures for solving different security issues, throughput, and by tolerating arbitrary faults without compromising the system operations. We evaluate the system behavior under different circumstances, such as continuous faults and attacks. Furthermore, the first performance evaluations show that the system is capable of supporting environments with thousands of users.

The PG test was found to be suboptimal as a screening test and, if used (before upper gastrointestinal endoscopy), it is mandatory to repeat it after 3 years.

A operação correta e contínua de provedores de identidade e serviços de controle de acesso são pontos críticos em novas gerações de redes e sistemas online, como redes virtualizadas e serviços sob demanda da computação em nuvem. Nesta perspectiva, este artigo tem como objetivo propor e demonstrar um modelo funcional para arquiteturas de serviços de identificação e autenticação tolerantes a faltas e intrusões. A viabilidade e aplicabilidade do modelo são avaliadas através de protótipos concretizados para os serviços OpenID e RADIUS. Os resultados indicam que um modelo funcional para o desenvolvimento de serviços de identificação e autenticação mais resilientes e confiáveis é viável.

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Este artigo apresenta o desenvolvimento de uma arquitetura para provedores OpenID resilientes e seguros, cujo objetivo é garantir propriedades essenciais como integridade, alta disponibilidade e confidencialidade de dados sensitivos. Para este fim são utilizados algoritmos para tolerar falhas arbitrárias, é proposto um componente seguro, com uma interface bem definida, e é detalhada a arquitetura que provê as propriedades almejadas ao sistema. A solução proposta supera trabalhos similares em diferentes aspectos, como vazão, latência, tolerância a falhas arbitrárias e confidencialidade (sem comprometer a escalabilidade do sistema). Os resultados demonstram que uma única instância do sistema suporta demandas de ambientes, como infraestruturas de rede e sistemas Web, com mais de 200k usuários.

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