A Lisbon story: short-term rental platforms and the housing market

Throughout Europe, many mayors have argued that house rental platforms such as Airbnb price locals out of city housing. Lisbon is an interesting case study on how to regulate this market. The median real estate price per square meter in the city increased more than 70% between the first quarter of 2016 and the last quarter of 2019. The number of overnight stays in Lisbon reached more than 11 million in 2019, about 20 times its resident population. João Pereira dos Santos writes about the causal impact of short-term rental regulations on the housing market and suggests policy implications

Establishing a high titer transient gene expression process in conditioned media for CHO-DG44 cells

Dissertação para obtenção do Grau de Mestre em BiotecnologiaTransient gene expression (TGE) allows for fast protein production in mammalian cells and has become a very important technology in the product development pipeline of biopharmaceuticals. Polyethylenimine (PEI) mediated, high-density transfections have allowed for transient processes exceeding ~300mg/L in CHO-DG44 cells. As such, the bottleneck of TGE is no more in the titers, but in the scale-up to volumes higher than 1L, because of the need for a medium exchange before transfection. It is known that if the transfection is done in a running culture, without a medium exchange (i.e in conditioned medium), the yields obtained are very low (~5 mg/L). In CHO-DG44 cells, this problem was explored from the point of view of transfection efficiency, gene delivery and transcription. A new insight is presented in this work: The low productivities are not due to a deficient gene delivery, but instead, to lower mRNA levels that we hypothesize to be related to a lower gene accessibility of the transfected plasmid. Further, the yields were improved from ~5mg/L to ~90mg/L (18-fold) by optimizing the conditions for transfecting in conditioned medium and utilizing sodium butyrate as a transcription enhancer. These results are expected to open paths for the successful scale-up of TGE

A simulation model for lean, agile, resilient and green supply chain management: practices and interoperability assessment

Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão IndustrialIn today’s global market, the environment of unpredictable events has imposed a competitiveness improvement that requires a greater coordination and collaboration among Supply Chain (SC) entities, i.e., an effective Supply Chain Management (SCM). In this context, Lean, Agile, Resilient and Green (LARG) strategies emerged as a response. However, interoperability issues are always presents in operations among SC entities. From the Information Technology (IT) perspective, among all the multi-decisional techniques supporting a logistics network, simulation appears as an essential tool that allow the quantitative evaluation of benefits and issues deriving from a co-operative environment. The present work provides a SC simulation model for analysing the effect of the interoperability degree of LARG practices in the SC performance, through Key Performance Indicators (KPI’s) such as cost, lead time and service level. The creation of two scenarios with a different point of view about the LARG practices allowed to analyse which one contributes to the best SC performance. Since some of the inputs were assumed, it was made a sensitivity analysis to validate the output of the simulation model. Based on the creation of six types of math expressions, it was possible to establish the connection between the effect of the interoperability degree of LARG practices and the SC performance. This analysis was applied on a case study that was conducted at some entities of a Portuguese automotive SC. The software used to develop the simulation model is Arena, which is considered a user-friendly and dynamic tool. It was concluded that SCM, interoperability and simulation subjects must be applied together to help organisations to achieve overall competitiveness, focusing their strategies on a co-operative environment

The effect of Brexit on British workers living in the EU

The effect of Brexit is an important topic in the European and British political agendas. This study examines the perspective of the EU countries, with regards how British citizens working in an EU country reacted to the end of free movement of workers. Employing synthetic control methods and using data from Portugal, we estimate how the behaviour of UK citizens working in Portugal would have evolved if the Remain vote had won the referendum. Our results suggest that the Brexit referendum reduced the number of UK citizens working in Portugal, particularly in the case of non-university educated, male individuals with temporary employment contracts. This reduction is explained by the decrease in the number of incomers. We also find that those UK citizens who were already working in Portugal before Brexit are less likely to leave the country.info:eu-repo/semantics/publishedVersio

The impact of a soda tax on prices and consumption

Increasing obesity-related problems and rising healthcare expenditures have led governments in developed countries to consider the introduction of soda taxes. We study a recent such tax, implemented in Portugal in February 2017 —one of the first soda taxes worldwide that increases with sugar content (0.08 euros per liter for drinks with less than 80 g of sugar per liter, and 0.16 euros per liter for drinks with 80 g or more sugar per liter, plus VAT). We use extremely detailed panel data from one of the two largest retailers in the country, covering the period between February 2015 and January 2018. We take advantage of the tax breakdown by sugar levels to examine how soda prices and quantities purchased reacted. For identification, we rely on difference-in-differences models with various vectors of fixed effects, comparing each group of products to water. For drinks with more than 80 g of sugar per liter, results indicate almost full price pass-through to the consumer. For drinks with less than 80 g of sugar per liter, price pass-through surpassed 100%. Regarding consumption, our findings suggest stockpiling behavior in the quarter when the tax was approved and before it was actually implemented. In the implementation period, there are no significant changes in quantities purchased for most beverages vis-à-vis water, with the exception of soda drinks with comparatively low levels of sugar. This suggests that benefits of the soda tax in terms of reducing sugar intake are mainly due to reformulation, as producers reduced the sugar content of some drinks to fall below the 80 g per liter threshold.preprintpublishe

Investigation of the Adhesive Properties of Bacterial Medium-Chain-Length Polyhydroxyalkanoates (mcl-PHA) for Medical Applications

Poly(hydroxyalkanoates) (PHAs) are a class of biodegradable and biocompatible polyesters with potential applications in biomedicine (Sodian et al., 2000). PHA are produced inside bacterial cells in the form of granules as carbon and energy storage compounds. There are three different PHA polymers, namely, short-chain-length PHAs (scl-PHA), medium-chain-length PHAs (mcl-PHA) and long-chain-length PHAs (lcl-PHA), depending on the size of their monomers. These polymers are formed during fermentation processes where bacteria grow with some defiant conditions (i.e. limitation in phosphorus, nitrogen, trace elements and/or oxygen), but with an excess supply of a suitable carbon source (Lee, 1996; Zinn and Hany, 2005). However, the use of effective carbon sources for production of PHA represent high costs to the fermentation process (Cruz et al., 2016). Therefore, the use of wastes or by-products as carbon sources, such as waste glycerol generated by the biodiesel industry, is important to reduce substantially the production costs of mcl-PHA (Muhr et al., 2013). In this work, a group of known mcl-PHA-accumulating bacteria, was studied for the accumulation of mcl-PHA using waste glycerol, from the biodiesel industry as the sole carbon source. Pseudomonas chlororaphis was found to be the most suitable candidate to produce mcl-PHA from glycerol, with a final CDW concentration of 3.28 g/L, among the tested strains, and with a polymer composed by hydroxyhexanoate (HHx), hydroxyoctanoate (HO), hydroxydecanoate (HD) and hydroxydodecanoate (HDd) monomers. Pseudomonas chlororaphis was studied in bioreactor cultivation experiments, in three different cultivation modes, namely, batch, pulse feeding and repeated batch and productivities of 0.026, 0.023 and 0.025 g/L h, respectively, were achieved. The polymer was recovered from the bacterial cells by Soxhlet extraction with chloroform. For the purification process, a standard technique with the re-dissolution of the mcl-PHA in chloroform followed by precipitation in ice cold ethanol was used. However, chloroform is a hazard solvent and cannot be used for industrial production. Hence, alternative recovery methods were also studied, using less hazardous solvents and the highest purity values were achieved by acetone, ethyl acetate and hexane solvents. Mcl-PHAs have unique mechanical properties that were studied by preforming an axial tensile test in a mcl-PHA film. In this assay, a tension at break values between 2.91 to 4.89 MPa were achieved in four replicates, together with an elongation at break of 212.39 to 296.87% and a Young modulus of 0.60 to 0.90 MPa. Since the main objective in this work was to develop a new fully natural bio-based adhesive to be used in medical applications, mcl-PHA, due to his tacky behaviour, presents its self as perfect candidate for this issue. So for that purpose some adhesion tests, using mcl-PHA and porcine skin as a model substrate, were made. It was performed a tension test, in three replicates, where it was attained values of tension at separation between 45.02 and 90.13 kPa. It was also made some shear tests, in three replicates and a tension at separation values of 10.02 to 12.87 kPa were achieved

Perspectivas sobre o conhecimento científico no ensino da filosofia no ensino secundário - O estatuto do conhecimento científico segundo Karl Popper e Thomas Kuhn

Numa primeira parte do meu relatório, apresento uma descrição resumida do meu estágio na Escola Secundária de Miraflores, durante o ano lectivo 2019/2020, onde faço uma descrição desta escola. Descrevo as minhas aprendizagens no núcleo de estágio em que me inseri, nas iniciativas organizadas no Plano Anual de Actividades (P.A.A.) e nas aulas assistidas da professora Alice Santos e do meu colega de estágio. Para terminar esta parte, conto a minhas primeiras experiências de leccionação no ensino oficial, começando por fazer uma apresentação geral das minhas turmas, para enumerar, de seguida, alguns objectivos presentes na orientação das minhas aulas e algumas considerações sobre os recursos e as estratégias que empreguei. Na segunda parte, elaboro um estudo sobre as epistemologias de Popper e Kuhn. Neste estudo, concentro-me primeiramente num aspecto que considero ser importante para compreender estas duas concepções da ciência: a circunstância de haver um movimento ou uma mudança constantes das teorias em ciência. De seguida, exponho algumas das consequências mais benéficas de considerarmos este aspecto das teorias científicas: a convicção de que não podemos aceitar as teorias sem as questionar. Rejeitado o dogmatismo, considero as duas alterativas possíveis: o espírito crítico e o cepticismo. Para terminar, examino o impacto destas perspectivas num contexto educativo