Overcome challenges in influenza virus-like particles downstream process

The development of new vaccines for influenza virus introduced a new generation of vaccines using virus-like particles (VLPs). The lack of genetic material, possibility of production on cell lines and presence of antigens with immunogenicity are the main advantages over the traditional vaccines. The development of a cost-effective downstream process while maintaining the high purity, potency and quality of VLPs is a challenge. In this thesis, several purification steps – clarification, concentration, chromatography, polishing and sterile filtration – were studied to develop a new downstream proves for influenza VLPs. In clarification step, a strategy using D0HC followed by Opticap XL SHC filters presented the best result. For concentration step, the cassette with cut-off of 300 kDa presented a higher yield on hemagglutinin recovery and the lowest process time. For chromatography step, the membrane Sartobind Q and the resin HiTrap Q HP were evaluated, concluding that resin HiTrap presented higher dynamic binding capacity and better resolution on elution. For polishing step, size-exclusion chromatography and multimodal chromatography operate in flow-through mode were compared. The last presented higher recovery yield on hemagglutinin and it was select due to the non-limitation for scale-up. Different materials were analysed for the final sterile filtration. A proof of concept run was performed were the optimized conditions and best devices were evaluated. In the end of process, it was obtained influenza VLPs with concentration and quality enough to advance for animal in vivo studies and for clinical phase I. Additionally, a new tool – magnetic sulphated cellulose particles – was evaluated with the goal to obtain purified and concentrated samples to use in characterization techniques. Overall, this thesis contributes to introduce a new tool and a novel cost-effective downstream purification process with high purity, potency and quality for the next generation of influenza vaccines - VLPs.O desenvolvimento de novas vacinas para o vírus de influenza introduziu uma nova geração de vacinas utilizando partículas semelhantes a vírus (VLPs). A ausência de material genético, possibilidade de produção em linhas celulares e presença de antigénios com imunogenicidade são as principais vantagens em relação às vacinas tradicionais. O desenvolvimento de um processo de purificação de baixo custo mantendo a elevada pureza, potencia e qualidade das VLPs é um desafio. Nesta tese, alguns passos de purificação – clarificação, concentração, cromatografia, polimento e filtração estéril final – foram estudados para desenvolver um novo processo de purificação de VLPs de influenza. Na clarificação, a estratégia usando os filtros D0HC seguido do Opticap XL SHC apresentaram os melhores resultados. Na concentração, a cassete com cut-off de 300 kDa apresentou um maior rendimento na recuperação de hemaglutinina e o mais baixo tempo de operação. Na cromatografia, a membrana Sartobind Q e a resina HiTrap Q HP foram avaliadas, concluindo-se que a resina apresenta maior capacidade de ligação dinâmica e maior resolução na eluição. No polimento, a cromatografia de exclusão molecular e a cromatografia multimodal, operada em flow-through comparadas. Esta última apresentou valores superiores de recuperação de hemaglutinina sendo escolhida por não conter limitações no escalamento. Diferentes materiais foram analisados na filtração estéril final. Na realização da corrida de prova de conceito as condições ótimas e os melhores materiais foram estudadas. No final do processo, obteve-se VLPs de influenza na concentração e qualidade suficiente para avançar para estudos em animais in vivo e para fase clínica I. Adicionalmente, uma nova ferramenta – partículas magnéticas de celulose sulfatada – foram estudadas com objetivo de obter VLPs purificadas e concentradas para utilização em técnicas de caracterização. Em geral, esta tese contribuiu para introduzir uma nova ferramenta e um novo processo de purificação mais económico com elevada pureza, potência e qualidade, para a nova geração de vacinas - VLPs.iBE

Co-designing an eHealth Intervention to Support the Self-Management of Fibromyalgia

Fibromyalgia is a rheumatic pathology that causes a wide range of symptoms that can appear individually, or in sets, such as fatigue, sleep disorders, attention, and concentration deficit, also having connection with musculoskeletal, psychological, cardiovascular, gastrointestinal disorders. This pathology has a greater predominance in women and, in Portugal, for every man there are six women with the diagnosis and a total of approximately two hundred thousand people (2.1% of the population). The non-pharmaceutical way to mitigate these symptoms is through physical therapy. Considering the pandemic moment in which we live, there have been many difficulties in having physical therapy sessions because of the fear of infection through contact with their physical therapists. There are also people who live in more isolated areas and with little access to healthcare, who often must travel to larger urban centers to get the care they need. Moreover, these people have difficulties in self-managing their illness, where depending on the day their symptoms can get worse, and they do not know how to deal with them. Currently, there is no specialized solution for people with this diagnosis that solves these problems, so this dissertation aims to study and design a solution that allows people diagnosed with fibromyalgia to self-manage their pathology, as well as have a closer contact with their physical therapist, by being able to perform their sessions in a hybrid way, i.e., in person or remotely. This solution was designed using a Co-Design approach, following the Design Thinking methodology, where the community (people with the diagnosis, physiotherapists, researchers and academics) were involved in all stages of the process, from problem identification and idealization of their solutions, to prototyping and its validation. This solution involved the development of a mobile application, having several important components, such as self management, telerehabilitation, motivation, community and communication. In order to evaluate the whole process and the usability of the solution, tests were performed with end users who had not yet participated in the design of the solution

Automatic plan generation and adaptation by observation : supporting complex human planning

Tese de doutoramento. Engenharia Informática. Universidade do Porto. Faculdade de Engenharia. 201

A study about E-WOM on an economic crisis context: The case of telecommunications

The study analyses the characteristics and effects of electronic Word-Of-Mouth (e-WOM) within online forums and social networks on Portuguese telecommunication consumers, considering Portugal is one of the European countries most affected by the economic crisis. The examination is focused on the present four major telecommunication operators running in the country – Portugal Telecom, ZON OPTIMUS, Vodafone and Cabovisão – but it also addresses emerging low cost operators, as Lycamobile. Through an exploratory methodology (Netnography), the obtained results demonstrate that these platforms have the potential to highly influence consumers’ decision making process and consumers’ attitudes towards brands; as well as that discussions on “price” and negotiations are avid and increasing on Consumer-to-Consumer (C2C) communication. However “quality”, “innovation” or “customer service” also demonstrate to be important for the observed consumers. Additionally, the absence of binding periods on telecommunication services appears not to be enough reason for the observed consumers to switch operators if those services are inferior to the ones with restraining periods of time, especially on home telecommunication services. The study also compares the ways by which telecommunication brands communicate on Facebook and exposes that MEO is, by far, leader on online Business-to-Consumer (B2C) communication because it effectively engages with its audience; as its strategy focuses on sharing content which is diversified and relevant for its followers, as well as demonstrating to care about feedback and adopting a sympathetic tone of voice. In the end, the study presents suggestions for telecommunication operators to enhance consumers’ satisfaction and increase their brand equity.O presente estudo analisa as características e efeitos do Word-Of-Mouth eletrónico (e-WOM) em fóruns online e redes sociais entre consumidores de telecomunicações Portugueses, considerando que Portugal é um dos países europeus mais afetados pela crise económica. A análise é focada nos atuais quatro maiores operadores de telecomunicações a atuar no país – Portugal Telecom, ZON OPTIMUS, Vodafone e Cabovisão – mas também aborda operadores low cost emergentes, como a Lycamobile. Servindo-se de uma metodologia exploratória (Netnografia), os resultados obtidos demonstram que estas plataformas têm potencial para altamente influenciar o processo de decisão dos consumidores e as suas atitudes perante as marcas; assim como as discussões sobre “preço” e negociações são ávidas e crescentes na comunicação entre consumidores (C2C). No entanto, “qualidade”, “inovação” ou “atendimento ao cliente” também demonstram ser importantes para estes consumidores. Adicionalmente, a liberdade na fidelização em serviços de telecomunicações não aparenta ser motivo suficiente para estes consumidores mudarem de operador, no caso de os serviços serem inferiores àqueles com fidelização. O estudo compara ainda as formas como as marcas de telecomunicações comunicam no Facebook, expondo que o MEO é, de longe, o líder online na comunicação entre empresa e consumidor (B2C), dado que se envolve eficazmente com a sua audiência; passando a sua estratégia por partilhar conteúdos diversificados e relevantes para os seus seguidores, e demonstrando apreciar o feedback enquanto adota um tom de voz simpático. No final, o estudo apresenta sugestões para que os operadores possam melhorar a satisfação dos seus consumidores e aumentar o seu brand equity

Arquitetura de elevada disponibilidade para bases de dados na cloud

Dissertação de mestrado em Computer ScienceCom a constante expansão de sistemas informáticos nas diferentes áreas de aplicação, a quantidade de dados que exigem persistência aumenta exponencialmente. Assim, por forma a tolerar faltas e garantir a disponibilidade de dados, devem ser implementadas técnicas de replicação. Atualmente existem várias abordagens e protocolos, tendo diferentes tipos de aplicações em vista. Existem duas grandes vertentes de protocolos de replicação, protocolos genéricos, para qualquer serviço, e protocolos específicos destinados a bases de dados. No que toca a protocolos de replicação genéricos, as principais técnicas existentes, apesar de completa mente desenvolvidas e em utilização, têm algumas limitações, nomeadamente: problemas de performance relativamente a saturação da réplica primária na replicação passiva e o determinismo necessário associado à replicação ativa. Algumas destas desvantagens são mitigadas pelos protocolos específicos de base de dados (e.g., com recurso a multi-master) mas estes protocolos não permitem efetuar uma separação entre a lógica da replicação e os respetivos dados. Abordagens mais recentes tendem a basear-se em técnicas de repli cação com fundamentos em mecanismos distribuídos de logging. Tais mecanismos propor cionam alta disponibilidade de dados e tolerância a faltas, permitindo abordagens inovado ras baseadas puramente em logs. Por forma a atenuar as limitações encontradas não só no mecanismo de replicação ativa e passiva, mas também nas suas derivações, esta dissertação apresenta uma solução de replicação híbrida baseada em middleware, o SQLware. A grande vantagem desta abor dagem baseia-se na divisão entre a camada de replicação e a camada de dados, utilizando um log distribuído altamente escalável que oferece tolerância a faltas e alta disponibilidade. O protótipo desenvolvido foi validado com recurso à execução de testes de desempenho, sendo avaliado em duas infraestruturas diferentes, nomeadamente, um servidor privado de média gama e um grupo de servidores de computação de alto desempenho. Durante a avaliação do protótipo, o standard da indústria TPC-C, tipicamente utilizado para avaliar sistemas de base de dados transacionais, foi utilizado. Os resultados obtidos demonstram que o SQLware oferece uma aumento de throughput de 150 vezes, comparativamente ao mecanismo de replicação nativo da base de dados considerada, o PostgreSQL.With the constant expansion of computational systems, the amount of data that requires durability increases exponentially. All data persistence must be replicated in order to provide high-availability and fault tolerance according to the surrogate application or use-case. Currently, there are numerous approaches and replication protocols developed supporting different use-cases. There are two prominent variations of replication protocols, generic protocols, and database specific ones. The two main techniques associated with generic replication protocols are the active and passive replication. Although generic replication techniques are fully matured and widely used, there are inherent problems associated with those protocols, namely: performance issues of the primary replica of passive replication and the determinism required by the active replication. Some of those disadvantages are mitigated by specific database replication protocols (e.g., using multi-master) but, those protocols do not allow a separation between logic and data and they can not be decoupled from the database engine. Moreover, recent strategies consider highly-scalable and fault tolerant distributed logging mechanisms, allowing for newer designs based purely on logs to power replication. To mitigate the shortcomings found in both active and passive replication mechanisms, but also in partial variations of these methods, this dissertation presents a hybrid replication middleware, SQLware. The cornerstone of the approach lies in the decoupling between the logical replication layer and the data store, together with the use of a highly scalable distributed log that provides fault-tolerance and high-availability. We validated the prototype by conducting a benchmarking campaign to evaluate the overall system’s performance under two distinct infrastructures, namely a private medium class server, and a private high performance computing cluster. Across the evaluation campaign, we considered the TPCC benchmark, a widely used benchmark in the evaluation of Online transaction processing (OLTP) database systems. Results show that SQLware was able to achieve 150 times more throughput when compared with the native replication mechanism of the underlying data store considered as baseline, PostgreSQL.This work was partially funded by FCT - Fundação para a Ciência e a Tecnologia, I.P., (Portuguese Foundation for Science and Technology) within project UID/EEA/50014/201

Configuração e interrogação com sistemas federados

Apesar da existência de produtos comerciais e da investigação na área, a construção de sistemas de informação com diversos componentes distribuídos, heterogéneos e autónomos - conhecidos como sistemas de informação federados - é ainda um desafio. Estes sistemas de informação oferecem uma visão global unificada sobre os vários modelos de dados (parciais). No entanto, a modelação destes sistemas é um desafio, já que modelos de dados como o relacional não incluem informação sobre a distribuição e tratamento de heterogeneidade. É também necessário interagir com estes sistemas de informação, através de interrogações sobre os diversos componentes dos sistemas, sem ser necessário conhecer os detalhes dos mesmos. Este trabalho propõe uma abordagem a estes desafios, através da utilização de modelos para descrição semântica, e.g. linguagem OWL (Ontology Web Language), para construir uma descrição unificada dos seus diversos modelos parciais. O modelo criado para dar suporte a esta descrição é, em parte, baseado em ontologias existentes, que foram alteradas e extendidas para resolver diversos desafios de modelação. Sobre este modelo, é criado um componente de software que permite a execução de interrogações SQL (Structured Query Language) sobre o sistema federado, resolvendo os problemas de distribuição e heterogeneidade existentes

Organizational innovativeness and addiction: moderator mediation effect through perceived usefulness on technostress

The goal of thisstudy isto explorethe effects of innovative organizations on employee’stechnostress and howaddiction to mobile Information and Communication Technologies (ICTs)mediates the relationship. We also includedthe moderator perceived usefulness of mobile ICTsto the model. By applying a survey in three differentmomentsto a final sample of 157 employees, we analyzedwhether addiction mediated the relationship between organizational innovativeness and two technostressors: techno overload and techno invasion. Additionally, we examineif individuals’perceived usefulness moderates the relationship between organizational innovativeness and addiction. Finally, we aimed to analyze whether the indirect effects of organizational innovativeness on techno overload and techno invasion, through addiction, are dependent on the level of perceived usefulness of mobile ICTs. Results haves hown a significant indirect effect between organizational innovativeness and both techno overload and techno invasion, through addiction, when perceived usefulness is high

Elastic scattering of protons and oxygen ions from light nuclei

This work presents the experimental study of elastic scattering of protons and oxygen ions, namely of the reactions 6Li(p,p)6Li, 7Li(p,p)7Li, 12C(p,p)12C, 19F(p,p)19F, 31P(p,p)31P, 16O(16O,16O)16O and 12C(16O,16O)12C in the energy range from 1.6 MeV to 3.9 MeV for 12C(p,p)12C scattering, 1 MeV to 2.7 MeV for 6Li(p,p)6Li, 7Li(p,p)7Li and 19F(p,p)19F scattering, 2.6 MeV to 4 MeV for 31P(p,p)31P scattering, 8 MeV for 16O(16O,16O)16O scattering and 2.8 MeV, 5.1 MeV and 8.1 MeV for 12C(16O,16O)12C scattering. Elastic scattering is always present in nuclear reactions and its study gives us information that can be used for theoretical calculations. The need for more precise values for the corresponding cross sections gives a motivation for its measurement, along with the measurement at different energies and angles, especially forward ones. The experimental work has been performed at LATR (Laboratório de Aceleradores e Tecnologias de Radiação) of CTN-IST (Campus Tecnológico e Nuclear – Instituto Superior Técnico) Sacavém, Portugal. It involved the use of the main experimental facilities of the laboratory. Improvements to the experimental setup needed for the measurements were made. Target preparation and characterization was also subject of intensive study, since it represents a struggle in nuclear experiments especially when high accuracy in measurements is required. Some of the cross sections were measured with more than one target, adding trust to the results obtained. Comparison with theoretical calculations was done, especially with the optical potential parameters available in the literature, showing that these calculations need some fine tuning, mainly for light elements. Our results showed that the accurate measurement of elastic scattering cross sections, especially at forward angles, where there is little data available, can provide reliable information both for obtaining accurate optical model parameters as well as for the characterization of excited states of nuclides

Seismic vulnerability assessment of existing reinforced concrete buildings in urban centers

Despite the recent advances in the analysis of the seismic performance of reinforced concrete structures, the assessment of large building inventories aimed at defining and prioritizing structural retrofitting strategies is still a technically challenging task. This paper aims to contribute to bridging this gap by presenting a simplified methodology for assessing the seismic vulnerability of reinforced concrete buildings, which is then applied to a group of 91 buildings affected by recent earthquakes with different macroseismic intensities. The presented methodology is based on the evaluation of eight parameters associated with different factors that affect the seismic response of the building, namely its structural features, foundation conditions, and position within the urban mesh. The formulation of each parameter and the relative weight attributed to each one of them were defined on the basis of post-earthquake damage observation and expert opinion. After defined, the proposed methodology is applied to Faro city center. Based on the results obtained, a cost benefit analysis is made considering a strengthening solution to the buildings with soft-story irregularity