The impact of higt speed technology on demand and productivity in European Railways : An econometric analysis

Tese de doutoramento. Faculdade de Engenharia. Universidade do Porto. 199

Enhancement of apparent resistance to ethanol in Lactobacillus hilgardii

The survival of Lactobacillus hilgardii, a highly ethanol-tolerant organism, after an ethanol challenge at 25% (v/v) for 10 min, increased by several log cycles when cells, grown in the absence of ethanol, were pre-treated with 10% (v/v) ethanol, 15% (v/v) methanol or 2% (v/v) butanol for 4 h. A temperature upshift (25 to 40°C) before ethanol challenge demonstrated a similar enhancement of apparent resistance to ethanol. Ethanol shock enhanced apparent resistance to methanol, butanol and heat challenges. The addition of chloramphenicol to cells prior to any pre-treatment did not significantly diminish the increase in ethanol tolerance, suggesting that de novo protein synthesis is not required for induced tolerance in this organis

From requirements to UI prototypes: a semi-automated approach

Software development poses multiple challenges, from requirements specification to final software production. We have developed two approaches, focused on complementary aspects of the problem. On the one hand, SCARP supports obtaining architectural models (hence, business layer code) from requirements models. On the other, MODUS produces UI prototypes from architectural models. This work presents their integration to obtain a development cycle going from requirements to executable prototypes, supported by semi-automated processes.Este trabalho e financiado por Fundos FEDER através do Programa Operacional Competitividade e Internacionalização – COMPETE 2020 e por Fundos Nacionais atraves da FCT – Fundação para a Ciência e a Tecnologia no âmbito do projeto POCI-01-0145-FEDER-006961.info:eu-repo/semantics/publishedVersio

Usability evaluation of the uCat tool

The uCat tool supports use cases specification, aiming at the generation of architectural prototypes, as per the SCARP approach. This short paper reports on the evaluation of its usability, a major factor in tool adoption by potential users.Este trabalho e financiado por Fundos FEDER através do Programa Operacional Competitividade e Internacionalização – COMPETE 2020 e por Fundos Nacionais atraves da FCT - Fundação para a Ciência e a Tecnologia no âmbito do projeto «POCI-01-0145-FEDER-006961».info:eu-repo/semantics/publishedVersio

Activity of Dekkera bruxellensis and the effect on the aroma profile of monovarietal wines

info:eu-repo/semantics/publishedVersio

Relational contracting and its combination with the BIM methodology in mitigating asymmetric information problems in construction projects

Project management in the construction sector is a complex and uncertain process and companies tend to look for the lowest value in the procurement of services and materials. However, contractors do not share the necessary information with the contracted parties and thus give rise to the asymmetric information (AI) phenomenon. The aim of this study is to perform an analysis of the determining factors in the adoption of relational contracting (RC) in combination with Building Information Modelling (BIM) to reduce AI. The results of a questionnaire survey, which was e-mailed to 14 specialists with solid experience (over twenty years) and knowledge in construction projects, revealed that the probability of the AI phenomenon occurring in Portugal is very high, and its impact on construction projects is equally high. The results also show that RC in combination with the BIM methodology contributes very positively to the mitigation of AI problems in construction projects in Portugal. Approximately 85% of respondents consider that the government should seek to reduce AI in the public works sector through the use of RC and its combination with the BIM methodology in the Portuguese Public Contracts Code

Noticiários de horário nobre em Portugal: duração e valor-notícia

Dado o papel que a informação, designadamente os jornais televisivos de horário nobre, têm nos canais televisivos generalistas e as estratégias de captação de audiências cada vez mais competitivas, vários modelos têm sido adoptados com implicações ao nível da estrutura, alinhamento e conteúdos. Considerando diversos estudos que utilizam uma metodologia de comparação de jornais televisivos de horário nobre em vários países, e partindo da ideia de que os jornais televisivos portugueses são em média demasiado longos, esta abordagem considera como eixo central de análise a sua duração. Pretende-se estudar a relação entre a duração do jornal televisivo e o seu modelo, ao nível da estrutura, alinhamento e conteúdos. Neste estudo adopta-se a perspectiva metodológica desenvolvida no projecto internacional “News definitions across cultures”, sendo a análise das notícias centrada, sobretudo, nos valores notícia (valência, desviância e significância). Dos resultados obtidos é possível concluir que há diferenças, quer quanto ao conteúdo, quer quanto à estrutura das notícias em função da duração dos jornais televisivos. Já ao nível do alinhamento do noticiário não foram encontradas diferenças significativas

The antimicrobial effect of wine on Listeria innocua in a model stomach system

A model stomach, containing a food matrix and a synthetic gastric Xuid, was used to study the bactericidal eVect of ingested wine on Listeria innocua. Volumes of wine equivalent to the ingestion of one glass and half a bottle, led, over a period of less than 2 h, to a reduction of 3 and 4 logarithmic cycles of the initial population respectively. The inXuence of ethanol and organic acids, wine constituents with known antimicrobial properties, was investigated. Ethanol exhibited a higher bactericidal eVect than the mixture of the main wine organic acids. When testing the organic acids separately, malic and lactic acids were found to have the strongest eVect. The combination of ethanol with the organic acids acted synergistically but to a lesser extent than wine itself. The results suggest that the ingestion of wine during a meal may diminish the quantity of Listeria persisting further in the alimentary tract

Factors influencing the production of volatile phenols by wine lactic acid bacteria

This work aimed to evaluate the effect of certain factors on the production of volatile phenols from the metabolism of p-coumaric acid by lactic acid bacteria (LAB) (Lactobacillus plantarum, L. collinoides and Pediococcus pentosaceus). The studied factors were: pH, L-malic acid concentration, glucose and fructose concentrations and aerobic/anaerobic conditions. It was found that, in the pH range of 3.5 to 4.5, the higher the pH the greater the production of volatile phenols. This behaviour is correlated with the effect of pH on bacterial growth. Increasing levels of L-malic acid in the medium diminished the production of 4-vinylphenol (4VP) and stimulated the production of 4-ethylphenol (4EP) by L. plantarum NCFB 1752 and L. collinoides ESB 99. The conversion of 4VP into 4EP by the activity of the vinylphenol reductase may be advantageous to the cells in the presence of L-malic acid, presumably due to the generation of NAD(+), a cofactor required by the malolactic enzyme. Relatively high levels of glucose (20 g/L) led to an almost exclusive production of 4VP by L. plantarum NCFB 1752, while at low concentrations (<= 5 g/L), 4EP is mainly or solely produced. Part of the glucose may be diverted to the production of mannitol as an alternative pathway to regenerate NAD+. This is corroborated by the experiments done with fructose, a compound that can be used as an electron acceptor by some bacteria becoming reduced to mannitol. In anaerobiosis, the reduction of 4VP into 4EP is clearly favoured, which is consistent with the need to increase the availability of NAD(+) in these conditions. This study shows that the amount and the ratio 4VP/4EP produced by LAB are greatly affected by certain environmental and medium composition factors. The behaviour of the bacteria seems to be driven by the intracellular NAD(+)/NADH balance.info:eu-repo/semantics/acceptedVersio