Repositório RCAAP

Neste estudo, eu investigo a conectividade dinâmica do retorno e da volatilidade entre os tokens não fungíveis (NFTs) e o sentimento do mercado de maio de 2018 a junho de 2022 usando um modelo de Autorregressão de Parâmetros Variáveis no Tempo (TVPVAR). Nesta investigação, eu descubro que certos segmentos de NFTs, como Art, Collectibles, Metaverse, Games e Utilities, são relativamente independentes do sentimento do mercado. Também descubro que os segmentos Collectibles e Games são os principais recetores do transbordo de volatilidade enquanto os restantes segmentos de NFTs considerados são principalmente transmissores. Essas descobertas fornecem conhecimentos particularmente importantes para investidores.

The paper is well documented and has quite relevant and updated information on key social and economic indicators over the period under analysis. Moreover, it openly brings up the major economic dilemmas of similar labor political experiences (like that “opposing” growth a nd redistribution), and to some extent, also of many developing countries that have tried to upgrade their economic and social status, as shown in the literature references. Based on their deep knowledge of the Brazilian economy, particularly at its present stage, the authors provide a subtle analysis of this issue and related topics.

Portuguese and Spanish universities have adopted well-defined royalty sharing arrangements over the last fifteen years. We investigate whether such royalty sharing arrangements have been effective in stimulating inventors’ efforts and in ultimately improving university outcomes. We base our empirical analysis on university-level data and two new self-collected surveys for both inventors and Technology Transfer Offices (TTOs). Evidence from the inventors’ survey indicates that one third of respondents are incentivised by current royalty sharing arrangements, one third could be incentivised by higher royalty shares, and the remaining third is totally insensitive to royalty sharing. Plain regressions on university level datasets suggest that the incentive effects documented by the inventors’ survey fail to translate into increased patenting or licensing income. It would seem that inventor royalty shares are not as influential as they could be, due to the poor commercial prospects of university inventions. Among other possible reasons, these poor prospects appear to reflect the fact that inventors are unable to produce potentially licensable inventions, or that eventually TTOs may not be focussing enough on commercialising their inventions.

High-pressure processing (HPP) is a non-thermal treatment in which, for microbial inactivation, foodsare subjected to isostatic pressures (P) of 400–600 MPa with common holding times (t) from 1.5 to6 min. The main factors that influence the efficacy (log10reduction of vegetative microorganisms) ofHPP when applied to foodstuffs are intrinsic (e.g. water activity and pH), extrinsic (P and t) andmicroorganism-related (type, taxonomic unit, strain and physiological state). It was concluded thatHPP of food will not present any additional microbial or chemical food safety concerns when comparedto other routinely applied treatments (e.g. pasteurisation). Pathogen reductions in milk/colostrumcaused by the current HPP conditions applied by the industry are lower than those achieved by thelegal requirements for thermal pasteurisation. However, HPP minimum requirements (P/t combinations)could be identified to achieve specific log10reductions of relevant hazards based on performancecriteria (PC) proposed by international standard agencies (5–8 log10reductions). The most stringentHPP conditions used industrially (600 MPa, 6 min) would achieve the above-mentioned PC, except forStaphylococcus aureus. Alkaline phosphatase (ALP), the endogenous milk enzyme that is widely used to verify adequate thermal pasteurisation of cows’milk, is relatively pressure resistant and its usewould be limited to that of an overprocessing indicator. Current data are not robust enough to supportthe proposal of an appropriate indicator to verify the efficacy of HPP under the current HPP conditionsapplied by the industry. Minimum HPP requirements to reduceListeria monocytogeneslevels byspecific log10reductions could be identified when HPP is applied to ready-to-eat (RTE) cooked meatproducts, but not for other types of RTE foods. These identified minimum requirements would result inthe inactivation of other relevant pathogens (SalmonellaandEscherichia coli) in these RTE foods to asimilar or higher extent.

This paper analyzes explanations identified in the literature for the subpar economic performance of the so-called peripheral member states of the Euro Area since the mid-1990s. It argues that a key factor was a Dutch disease-like transmission mechanism, as the adoption of the euro led to a capital inflow shock. This resulted in a structural shift in the productive structure of the peripheral economies away from technologically advanced manufactured goods, which are characterized by higher productivity growth. As a consequence, the peripheral member states specialized in non-tradable sectors, and in low-technology and labor-intensive tradable goods sectors, which largely explains the peripherals’ low economic growth, low productivity growth, and growing macroeconomic imbalances.

The pasteurization of beer occurs at the end of the industrial production, after fermentation. Generally, a mild thermal process (60°C) is employed aiming to inactivate the fermenting yeast and potential spoilage microorganisms, thus extending the beer shelf-life at room temperature. The heat treatment negatively affects the original beer freshness and flavor. In this study, beer pasteurization using emerging non-thermal technologies, namely, highpressure processing (HPP), pulsed electric fields (PEF), and ultrasound (US), was reviewed, including the effect on microbial inactivation and beer quality. The combination of non-thermal methods with mild heat for more efficient pasteurization of beer was also reviewed. All technologies caused microbial inactivation in beer. However, room temperature HPP treatment was the most efficient method, delivering the minimum 15 PU (pasteurization units) to beer after seconds (e.g., 300 MPa for 27 s), as opposed to thermal and TS treatments which required several minutes, while causing a negative impact on beer sensory. As expected, PEF + heat caused a higher microbial inactivation than PEF alone, and yeast ascospores were more resistant than vegetative yeast cells. Non-thermal PEF (35–45 kV/cm) caused 3–5.8 log reductions in vegetative bacteria. Studies on thermal assisted PEF and ultrasound combined with low heat (50–55°C) showed processing times in the magnitude of microseconds for PEF pasteurization and 0.5–2min (depending on the temperature) for TS pasteurization. With respect to impact of these technologies on beer quality, HPP, thermosonication (TS), high pressure homogenization (HPH), and dense phase CO2 (DPCD) treatments revealed less effect on beer sensory properties, better retaining the freshness of original beer, compared to thermally processed beers.

This study investigated how the COVID 19 pandemic impacted the STI literature. We addressed this question by comparing the contents of the STI literature before COVID19 and since the pandemic's beginning, using bibliometric and clustering techniques as well as a systematic qualitative review of key publications. We find that the concentration in the top ten countries was lower in the Covid Publications than in the non-Covid ones and that the countries hit hard by the pandemic had a higher participation rate in the Covid publications set. Of the 27 selected journals, only 18 had Covid-related publications, and of these, only six journals had a higher participation rate in the Covid set. For the nonCovid publications set, the bibliographic coupling of the journals revealed a clear distinction between two groups, a management/business related one and one of core STI journals. For the 2019 and 2020_21 non-Covid publications set, we obtained a similar result of four clusters that were interpreted as representing the following topics: Firm Innovation, Innovation Management, Scientometrics, and Gender, respectively. With regard to the Covid publications, the cluster analysis revealed that the Covid related STI literature can be divided into four different thematic clusters: Economic Dynamics and Entrepreneurship; New Innovation Models; Scientometrics and Education. The overlay map analysis revealed that most of the shared terms between the non-Covid and Covid sets belonged the Scientometrics cluster, a research theme identified as central by clusters in both sets. Also, we found an intersection in the “Firm Innovation” cluster of the nonCovid publications centered around small business and entrepreneurship topics. However, the publications within the Covid set focused on their role in the economic dynamics and recovery. The Covid pandemic will have lasting effects on several dimensions of science, technology and innovation-related areas and this research aims to help to identify and gain insight into the potential STI knowledge fields related to the impact of Covid-19

The emergence of resistant microorganisms towards standard antibiotics has stimulated an on-going exploration for new sources of antimicrobials. The microbial susceptibility of extracts produced from leaf, bark, or rhizome parts of nine different New Zealand bushes was investigated using liquid broth dilution and agar plating techniques. Minimum inhibitory (MIC) and lethal concentrations (MLC) were expressed in micrograms of dry extract per milliliters of solution. The lowest MIC of 62.5 µg/mL was determined for methanol extract of Kunzea ericoides against Bacillus cereus and Candida albicans, and ethyl acetate extract of Pseudowintera colorata against Staphylococcus aureus. Additionally, K. ericoides also presented the lowest MLC of 250 µg/mL against S. aureus and B. cereus (methanol extract), and against S. aureus (ethyl acetate extract). The methanol extract of Weinmannia racemosa was lethal to B. cereus (MLC = 250 µg/mL). Some of the extracts of Phormium tenax, Schefflera digitata, and Pomaderris kumeraho were antimicrobial against S. aureus and B. cereus (MIC = 500 µg/mL). The extracts of Geniostoma ligustrifolium and Melicytus ramiflorus plants did not exhibit antimicrobial activity.

No contexto atual as organizações procuram muitas vezes posicionar-se através de patrocínios, sendo uma forma mais leve de mostrar a marca sem ser estritamente comercial. Deste modo, é importante perceber os fatores que influenciam um consumidor quando é exposto a um patrocínio, e também os antecedentes da intenção de compra, de maneira a poder otimizar a imagem de marca que têm do patrocínio, como também a sua atitude a estas marcas que pretendem associar-se ao seu clube de futebol. A presente dissertação investiga os antecedentes da intenção de compra de um adepto e por sua vez, os antecedentes da atitude em relação à marca a associada e à imagem de marca do patrocínio. Para isso, foi realizado um estudo de natureza explanatória, visto que pretende verificar a relação de causa e efeito das variáveis, recorrendo à elaboração de um questionário partilhado online, que obteve 225 respostas, para deste modo perceber a atitude em relação à marca associada, a imagem de marca e por fim, os antecedentes da intenção de compra. Ao analisar os resultados, verifica-se que a congruência entre o clube e o patrocínio é o fator que mais influencia positivamente quer a atitude em relação à marca associada, quer a imagem de marca do patrocínio, embora o envolvimento do adepto também seja um fator importante. Estes dois fatores influenciam positivamente a intenção de compra, especialmente a atitude em relação à marca associada. Deste modo, as organizações que pretendem entrar no mercado desportivo devem dar importância à atitude em relação à marca associada e à imagem de marca do patrocínio, melhorando através da congruência entre o clube e o patrocínio, como também do envolvimento do adepto, para conseguir deste modo otimizar a intenção de compra do consumidor.

Nos dias que correm os consumidores são cada vez mais bombardeados com uma grande quantidade de informação. Uma marca precisa de ecoar na mente dos consumidores. É cada vez mais importante que os gestores em conjunto com os designers analisem estratégias para se destacarem e chamarem a atenção do consumidor. Uma das estratégias consideradas mais eficazes são os diferentes elementos de marca, tais como como Logótipos, Jingles, Slogans, Embalagens, Nome e as Personagens. Neste estudo, foram então investigados os principais elementos da marca considerando a sua influência na imagem da marca e na intenção de compra do consumidor. Para responder a esta questão foi realizado uma pesquisa explanatória, com recurso a realização de um questionário que recolheu a resposta de 238 inquiridos, para assim conseguir perceber como os elementos da marca influenciam a imagem da marca na mente do consumidor e como isso influencia a sua intenção de compra. Considerando os resultados, é possível verificar que existe uma influência significativamente positiva dos elementos na imagem de marca e na intenção de compra. Contudo, apenas quatro dos seis elementos analisados influenciam de facto a imagem da marca, os jingles e os slogans apesar de ajudarem a chamar a atenção do consumidor não são significativos para a imagem que o consumidor cria da marca. Desta forma, as marcas devem focar-se em criar elementos que representem a sua personalidade e missão e que consigam ir de acordo com a imagem que o consumidor tem de si para criar um sentimento de pertença e familiaridade para levar a que o consumidor finalize a sua intenção de compra.

This paper assesses the performance of GAPIs and OTICs, two different types of university technology transfer offices that have been active in Portuguese higher education institutions, since 2000 and 2006, respectively. Data originating from a survey of these offices were analysed through both cluster analysis and the estimation of a Partial Least Squares-Structural Equation Modelling (PLS-SEM) model. Results show that the institutional nature of each of the surveyed organisations implies different behaviours and outputs. Furthermore, it is shown that the resources and activities of the surveyed offices determine their performance concurrently with regard to technology transfer, licencing contracts and technology-based spin-offs. The results of this study may be particularly relevant for countries that are in the process of developing their university technology transfer activities, as they can help to shape policies in relation to TTOs’ funding and resource allocation during the earlier stages of these activities.

In this paper we measure the relative efficiency of Portuguese local municipalities in a non-parametric framework approach using Data Envelopment Analysis. As an output measure we compute a composite local government output indicator of municipal performance. This allows assessing the extent of municipal spending that seems to be "wasted" relative to the "best-practice" frontier. Our results suggest that most municipalities could achieve, on average, the same level of output using fewer resources, improving performance without necessarily increasing municipal spending. Inefficiency scores are afterwards explained by means of a Tobit analysis with a set of relevant explanatory variables playing the role of non-discretionary inputs.

A interpretabilidade de um modelo pode ser definida como o grau de compreensão sobre o funcionamento interno de um modelo, permitindo perceber as causas sobre o qual recai o resultado. Na modelação estatística, pode verificar-se um trade-off entre a interpretabilidade e a precisão da previsão: modelos de interpretabilidade natural revelam uma menor precisão relativamente a modelos mais complexos. A previsão do Produto Interno Bruto é um aspeto fundamental para a aplicação de políticas económicas, com particular atenção para políticas monetárias e políticas orçamentais. Nesse sentido e tendo em conta que os modelos de machine learning preveem melhor a volatilidade económica, tem se vindo a assistir a uma revolução do método de previsão macroeconómico utilizado pelas principais organizações políticas nacionais e internacionais. O objetivo deste trabalho prende-se em investigar se um black-box, Extreme Gradient Boosting (XGBoost) pode superar os métodos de interpretabilidade natural selecionados, Regressão linear e Árvore de decisão na previsão do Produto Interno Bruto (PIB) per capita para dados de painel e identificar medidas de importância das variáveis para melhorar a transparência dos modelos de machine learning. Se as organizações políticas e financeiras forem capazes de prever e interpretar corretamente os fatores, podem implementar políticas mais eficazes. Para a análise de interpretabilidade de XGBoost, utilizam-se os seguintes métodos, Shapley Additive ExPlanations (SHAP), Permutation Feature Importance e Partial Dependence Plot. Através destes métodos pretendemos mostrar que os resultados obtidos por XGBoost podem ser interpretados sem um grande esforço computacional e garantir maior vantagem competitiva. Contudo, como será aprofundado durante este trabalho, verifica-se que o modelo XGBoostserá o modelo com melhor precisão de previsão para os dados de painel.

taly and Portugal have characteristics in common and some relevant differences, both of which provide useful inputs for a comparative analysis. Lucchese et al. (Industrial policy and technology in Italy, 2016) argue that deindustrialization in Italy stems partially from the shortcomings of industrial policy, which has been unable to promote the development of more knowledge-intensive activities. In contrast, our assessment of industrial policy in Portugal indicates that the absence of structural change towards more knowledge-intensive activities does not seem to result from the absence of adequate industrial policy measures. Even though most of the policy instruments that have been put in place in Portugal being of a ‘horizontal’ nature, support has been unevenly distributed across industries, often being concentrated in more technology-intensive industries. We conclude that despite existing room for improvements in the industrial policies, overcoming the current crisis in the Southern belt of the euro zone will require decisive changes in macroeconomic policies.

The application of pulsed electric fields (PEFs) for the inactivation of Escherichia coli, suspended in a protein shake beverage and diluted with sterilized distilled water was carried out. Square bipolar pulses in the range of 25–40 kV/cm electric field intensities were applied at different frequencies (400–900 Hz) to investigate the effect of different PEF conditions on the microbial population and proteins relevant to this functional beverage. The treatment temperature was kept below the lethal temperature of the microorganism under investigation. As power consumption plays an important role in the efficiency of the PEF application, the dissipated power was also estimated. Four log reductions in the E. coli population were obtained with 10 pulses at a 40 kV/cm field intensity and 25 pulses at a 25 kV/cm field intensity. PEF-treated whey-protein concentrates showed less denaturation in proteins than thermally treated concentrates, especially for lower electric field intensities (0% denaturation ± 0.007 at 25 kV/cm and 900 Hz, 4.41% denaturation ± 0.008 at 40 kV/cm and 400 Hz). Soy protein isolates manifested high sensitivity to PEF processing and resulted in denaturation and aggregation in the protein structure.

Atualmente, cada vez mais os fatores ambientais, sociais e éticos têm uma maior importância no processo de tomada de decisão. No entanto, a diversidade cultural tem influência no desempenho financeiro de uma empresa e na sua adoção de práticas de responsabilidade social. Deste modo, a presente dissertação tem como objetivo perceber de que forma a cultura de um país e as características sociais de um indivíduo influenciam o desempenho ESG. De forma a analisar esta relação, recorreu-se a uma amostra de 747 empresas cotadas no índice bolsista e às dimensões culturais definidas por Geert Hofstede. Os resultados obtidos sugerem que a dimensão Individualismo, Masculinidade, Aversão à Incerteza e Indulgência têm um papel fundamental na adoção de medidas de responsabilidade social. O presente estudo enriquece a literatura existente uma vez que aborda o efeito de cada vertente do ESG individualmente.

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DSGE are for a time the favorite models in the simulation of monetary policies at the central banks. Two of its basic assumptions are discussed in this paper: (a) the absence of endogenous nonlinearities and the exogenous nature of shocks and (b) the persistence of or the return to equilibrium after a shock, or the absence of dynamics. Our analysis of complex financial markets, using historical data of S&P500, suggests otherwise that financial regimes endogenously change and that equilibrium is an artifact.

This dissertation presents evidence that there is a relationship between the stock market and non-regulated crypto markets, particularly in times of uncertainty of the macroeconomic environment, as the year 2020. I exploit the relationship between the S&P500 and DAX stock indices and the cryptocurrency markets of Bitcoin and Ethereum, using a dataset that comprehends daily price variations between 2017 and 2022. A breaking point was created in 2020 in order to understand the relationship between the stock and cryptocurrency markets in two subsamples that shape different market environments. Before 2020, there is no evidence found in volatility spillovers from the S&P500 to Bitcoin market at a 5% significance level. However, the findings suggest that after the breaking point, there are volatility spillovers from the stock market (mainly S&P500) to Bitcoin and Ethereum markets, particularly in the year 2020, a critical period of the pandemic crisis. Vector Autoregressive methods were used in order to model the time series, allowing for the study of Granger causality relations and perform Impulse Response Functions. A triangular VAR-GARCH model is also estimated to further incorporate heteroskedasticity in the series.

Nos últimos anos a produção de morango tem diminuído em Portugal devido à desatualização do setor. Face aos atuais problemas há uma grande necessidade de inovar, recorrendo a tecnologias de produção com as plantas ‘tray’. O ensaio teve como objetivo avaliar a dinâmica da floração destas plantas nas cultivares ‘Darselect’, ‘Deluxe’, ‘Donna’ e ‘Dream’ no primeiro ciclo de produção (outono-inverno) e a viabilidade de se obter uma segunda produção na primavera com recurso à tecnologia de luz LED. De setembro a outubro deu-se a evolução dos primórdios florais diferenciados no viveiro, não se verificando diferenciação floral e encontrando-se os meristemas em estado vegetativo. A ‘Donna’ apresentou maior número de meristemas reprodutivos diferenciados no viveiro, com mais 8 meristemas planta-1 que as outras cultivares. Contudo, estes meristemas não se traduziram num maior potencial produtivo. Na segunda metade do ciclo verificou-se a diferenciação floral de novos gomos, com um incremento acentuado no número de meristemas florais e com a ‘Darselect’ a apresentar maior número de estruturas reprodutivas, traduzindo-se numa maior produtividade (2,54 kg/m2 ). As restantes cultivares apresentaram uma produtividade semelhante (valor médio 1,47 kg/m2 ). A dinâmica da floração foi semelhante entre as cultivares. No segundo ciclo, as luzes LED tiveram influência principalmente no comprimento médio do pecíolo e do pedúnculo. A ‘Deluxe’ apresentou maior vigor vegetativo, sendo na maioria das datas de amostragem diferente das outras cultivares (P<0,001). A luz LED influenciou a produção precoce das cultivares ‘Donna’, ‘Dream e ‘Darselect’, não tendo efeito na produção total das cultivares (6,0 kg/m2 LED vs 5,9 kg/m2 controlo).