Browsing by Author "Ribeiro, Jorge"
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- Evaluation of PVA biodegradable electric conductive membranes for nerve regeneration in axonotmesis injuries: the rat sciatic nerve animal modelPublication . Ribeiro, Jorge; Caseiro, Ana Rita; Pereira, Tiago; Armada‐da‐Silva, Paulo Alexandre; Pires, Isabel; Prada, Justina; Irina, Amorim; Reis, Inês Leal; Amado, Sandra; Santos, José Domingos; Bompasso, Simone; Raimondo, Stefania; Varejão, Artur Severo Proença; Geuna, Stefano; Luís, Ana Lúcia; Maurício, Ana ColetteThe therapeutic effect of three polyvinyl alcohol (PVA) membranes loaded with electrically conductive materials - carbon nanotubes (PVA-CNTs) and polypyrrole (PVA-PPy) - were tested in vivo for neuro-muscular regeneration after an axonotmesis injury in the rat sciatic nerve. The membranes electrical conductivity measured was 1.5 ± 0.5 × 10-6 S/m, 579 ± 0.6 × 10-6 S/m, and 1837.5 ± 0.7 × 10-6 S/m, respectively. At week-12, a residual motor and nociceptive deficit were present in all treated groups, but at week-12, a better recovery to normal gait pattern of the PVA-CNTs and PVA-PPy treated groups was observed. Morphometrical analysis demonstrated that PVA-CNTs group presented higher myelin thickness and lower g-ratio. The tibialis anterior muscle, in the PVA-PPy and PVA-CNTs groups showed a 9% and 19% increase of average fiber size area and a 5% and 10% increase of the "minimal Feret's diameter," respectively. No inflammation, degeneration, fibrosis or necrosis were detected in lung, liver, kidneys, spleen, and regional lymph nodes and absence of carbon deposits was confirmed with Von Kossa and Masson-Fontana stains. In conclusion, the membranes of PVA-CNTs and PVA-PPy are biocompatible and have electrical conductivity. The higher electrical conductivity measured in PVA-CNTs membrane might be responsible for the positive results on maturation of myelinated fibers. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1267-1280, 2017
- Psychosocial risk managementPublication . Fernandes, Ana; Figueiredo, Margarida; Ávidos, Liliana; Ribeiro, Jorge; Vicente, Dinis; Neves, José; Vicente, HenriqueA number of guidelines for Psychosocial Risk Management in organizations have been proposed in recent decades; however, some reviews on the subject also highlights that the terms Stress and Psychosocial Risks (PRs) are not mentioned explicitly in most pieces of legislation, leading to lack of clarity on the terminology used. To improve the way of dealing with this type of vulnerability and to allow organizations to successfully manage PRs, this work proposes and characterizes a workable problem-solving method in which the PRs can be evaluated for the entropy they generate within the organization. The analysis and development of such a system is based on a series of logical formalisms for Knowledge Representation and Reasoning that are grounded on Logic Programming, complemented with an Artificial Neural Network approach to computing.
- Social Role in Organizational Management Understanding People Behavior and MotivationPublication . Maia, Nuno; Neves, Mariana; Barbosa, Agostinho; Carrulo, Bruno; Araújo, Nuno; Fernandes, Ana; Vicente, Dinis; Ribeiro, Jorge; Vicente, Henrique; Neves, JoséThe aim of this work is to respond to the need to rethink the behavior and motivation of employees in their relationship with managers and social groups, i.e., one’s main goal is based on increasing engagement in order to reach organizational goals and job workers satisfaction, a complex concept that is influenced by different causes. Indeed, in this work it is analyzed the impact of working conditions on job satisfaction. This is where attention is drawn to the concept of entropy, since we are not focusing on the value a variable can take, but on the effort that has been expended to obtain it. The idea of entropy comes from a principle of thermodynamics dealing with energy. It usually refers to the idea that everything in the universe eventually moves from order to disorder, and entropy is the measurement of that change, that is used here to understand and assess the workers behavior and motivation. The subsequent formal model is based on a set of logical structures for knowledge representation and reasoning that conform to the above entropic view, then leading to an Artificial Neural Network approach to computation, an archetypal that considers the motive behind the action.
- A Thermodynamic Assessment of the Cyber Security Risk in Healthcare FacilitiesPublication . Fernandes, Filipe; Alves, Victor; Machado, Joana; Miranda, Filipe; Vicente, Dinis; Ribeiro, Jorge; Vicente, Henrique; Neves, JoséOver the last decades a number of guidelines have been proposed for best practices, frameworks, and cyber risk assessment in present computational environments. In order to improve cyber security vulnerability, in this work it is proposed and characterized a feasible methodology for problem solving that allows for the evaluation of cyber security in terms of an estimation of its entropic state, i.e., a predictive evaluation of its risk and vulnerabilities, or in other words, the cyber security level of such ecosystem. The analysis and development of such a model is based on a line of logical formalisms for Knowledge Representation and Reasoning, consistent with an Artificial Neural Networks approach to computing, a model that considers the cause behind the action.