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- Fast decellularization process using supercritical carbon dioxide for trabecular bonePublication . Duarte, Marta M.; Ribeiro, Nilza; Silva, Inês V.; Dias, Juliana R.; Alves, Nuno M.; Oliveira, Ana L.Decellularization is a process that consists on the removal of immunogenic cellular material from a tissue, so that it can be safely implanted as a functional and bioactive scaffold. Most decellularization protocols rely on the use of harsh chemicals and very long washing processes, leading to severe changes in the ultrastructure and loss of mechanical integrity. To tackle these challenges, supercritical carbon dioxide (scCO2) is herein proposed as an alternative methodology for assisting decellularization of porcine trabecular bone tissue and is combined, for the first time, with Tri(n-butyl) phosphate (TnBP). Histological and DNA analysis revealed that both TnBP and scCO2 were able to extract the DNA content from the scaffolds, being this effect more pronounced in treatments that used TnBP as a co-solvent. The combined protocol led to a decrease in DNA content by at least 90%, demon- strating the potential of this methodology and opening new possibilities for future optimizations.
- The influence of generalized and arbitrary institutional inefficiencies on the ownership decision in cross-border acquisitionsPublication . Falaster, Christian; Ferreira, Manuel Portugal; Li, DanExtant studies have focused on conceptualizing and measuring the general quality of the institutions and their impact on an array of firms’ strategies. We distinguish two dimensions of institutional inefficiencies in a host country – generalized and arbitrary – and theorize from a knowledge perspective their impact on the acquirers’ ownership decisions in cross-border acquisitions (CBAs). Our empirical examination of 5522 CBAs by firms entering emerging economies reveals that, when exposed to a higher level of host-country generalized institutional inefficiencies, the acquirer tends to take a lower ownership in a CBA. When exposed to higher levels of arbitrary institutional inefficiencies, however, the acquirer tends to take a higher ownership in a CBA. We further find that these relationships are contingent upon the acquirer’s experience in the host region and technological nature.
- Context matters less than leadership in preventing unethical behaviorPublication . Alvez, Marlond; Marques, Tânia; Ramalho, NelsonEver since corporate scandals became a concern of public interest, leaders have been a common target for attributing responsibilities and ethical leadership has been suggested as a solution to prevent it. However, organizations, especially MNCs, are permeable to their social environment, and therefore, a contextual approach is called for. This study is set to empirically test a sequential mediation model bridging ethical leadership to employees’ unethical behavior via instrumental ethical climate and employee displacement of responsibility embedded in its society’s ethical standards represented by the country’s corruption index that acts as a moderator. A total of 184 participants comprised in 39 teams across 13 countries, answered a dyadic two-waved survey. Findings show that ethical leadership has an indirect influence on unethical behavior avoidance by diminishing the instrumental ethical climate and frustrating the displacement of responsibility of individuals. In addition, results suggest this process is not sensible to the corruption levels of countries. Such findings suggest organizations are less prone to adjust their ethical standards to the environment than usually expected. The unavoidable conclusion is that in MNCs, ethical leaders may suffice to counter any corruption-like pressure from the social environment but likewise, may be what it takes to foster a corrupted organization in a society that values ethical principles in business.
- Cuidar em Situação de Catástrofe: Um desafio para a educação em EnfermagemPublication . Santos, Paulo; Rabiais, Isabel; Amendoeira, José Joaquim Penedos; Henriques, CarolinaA necessidade de educação na área de catástrofe surge como uma prioridade e deve ser encarada como uma preocupação multidimensional (Veenema, et al., 2017). A educação em enfermagem deve promover o desenvolvimento do conhecimento e o raciocínio clínico sobre os valores e os princípios fundamentais dos cuidados de enfermagem nesta área específica.
- Swanwick, HelenaPublication . Lucas, Eugénio
- O Impacto da Liderança e das Recompensas no Sucesso da Gestão de Projetos, mediado pela coesão de equipas de trabalhoPublication . Santos, Miguel Alcobia; Marques, Alzira Maria Ascensão; Espírito Santo, Pedro Manuel doCom o objetivo de estudar o impacto da liderança e das recompensas no sucesso da gestão de projetos, mediado pela coesão de equipas de trabalho, foi estimado um modelo de equações estruturais com recurso ao software SmartPLS, tendo por base os dados recolhidos por questionário numa amostra de 102 indivíduos que trabalham em equipas de gestão de projetos. Os resultados obtidos, verifica-se que a liderança diretiva e a liderança de suporte influenciam positivamente a coesão de equipas de trabalho. Neste trabalho, verificou-se também que a liderança diretiva tem um impacto positivo no sucesso da gestão de projetos para o cliente e que as recompensas financeiras têm um efeito inverso.
- Performance analysis of AES encryption operation modes for IoT devicesPublication . Serra, Luís Filipe Dias; Gonçalves, Pedro Gonçalo Baptista; Frazão, Luís Alexandre Lopes; Antunes, Mário João GonçalvesDaily activities have been increasingly supported by intelligent devices and applications. Smart devices are constantly communicating through the Internet of Things (IoT) networks, either by sending collected data and notifying the actions taken or by receiving instructions for actions to be taken. Most of this communication requires the confidentiality of data through the usage of encryption algorithms, being the Advanced Encryption Standard (AES) algorithm one of the most used. However, how do the operation modes of AES algorithm perform in a resource-constraint device? This paper aims to evaluate the impact on the time to encrypt and decrypt different sized messages in IoT devices when using each one of the five AES modes of operation and the three key sizes defined. The test scenario was implemented using two programming languages, running on a Raspberry Pi device. The results achieved infers that Python was quicker and had a more homogeneous result set than JavaScript implementation in most AES operation modes. These results help to understand the trade-off between IoT devices' security needs and delays in communication caused by the selection of the AES algorithm operation mode.
- An easy-to-use tool to inject DoS and spoofing networking attacksPublication . Almeida, Rafaela; Pacheco, Vasco; Antunes, Mário; Frazão, LuísComputer network attacks are vast and negatively impact the infrastructure and its applicational services. From a cyber offensive and defensive perspective, there are a plethora of tools to craft and inject customized malicious packets in the network and exploit operating systems and application vulnerabilities. Those tools are however hard to operate by practitioners with less knowledge on networking fundamentals and students in the early stage of their studies. This paper proposes an easy-to-use application tool that can produce customized Denial of Service (DoS) and spoofing attacks. It was developed in Python and takes advantage of scapy library to process and inject network packets. A set of experiments was made, and the results obtained show the efficiency and accuracy of the attacks, by impairing the proper functioning of the victim's machines.
- An end-to-end cryptography based real-time chatPublication . Melo, Tiezer; Barros, António; Antunes, Mário; Frazão, LuísConfidentiality protects users' data from digital eavesdroppers when traveling through the Internet. Confidentiality is complex and costly, especially on applications that involve communication and data exchange between multiple users. Cryptography has been the most used medium to achieve confidentiality, being the greatest challenge the sharing of a secret key to a group of people in a safe and effective way. This paper presents a chat application that implements an innovative way of sending messages with end-to-end encryption, in real-time, with a dynamic key store, and without the existence of data persistence. The application stands out from the others by the fact that it innovates the way the keys are shared with multiple users.
- O impacto da utilização das TIC no exercício da profissão de contabilista certificado A perceção dos contabilistas certificados do distrito de LeiriaPublication . Martins, José Luís Pereira; Francisco, Tiago Miguel MonizA rápida evolução das tecnologias de informação e comunicação (TIC) tem colocado muitos desafios à profissão do contabilista. Neste trabalho examinamos como se tem processado esta evolução, tentando destacar os maiores impactos, principais vantagens e desvantagens da utilização das TIC. Pretendemos contribuir para um melhor conhecimento do impacto da utilização das TIC no exercício da profissão de contabilista, avaliado pela perceção dos profissionais sobre o uso da tecnologia no seu contexto profissional. Os nossos resultados mostram que a utilização destas tecnologias é fundamental e confere aos seus utilizadores um conjunto de benefícios, nomeadamente em termos de aumento de eficiência e rapidez no acesso e processamento de informação, redução do tempo necessário para realização de algumas tarefas, permitindo melhorar a qualidade, fiabilidade e disponibilidade da informação financeira.