Browsing by Issue Date, starting with "2025-05"
Now showing 1 - 10 of 122
Results Per Page
Sort Options
- Revelar o potencial das cúpulas de carvalho como matéria prima de base biológicaPublication . Caeiro, Ana; Costa, Ricardo; Neiva, Duarte; Gominho, Jorge; Paulo, Joana Amaral
- Does the Russia-Ukraine war cause exchange rate depreciation? Evidence from the rouble exchange ratePublication . Jia, Haibo; Yun, Hao; Khan, Khalid; SpringerThis paper aims to examine the impact of the Russian-Ukraine war on the USD/ RUB rate. The outcome reveals that war has severe adverse consequences for the USD/RUB rate. It implies that the exchange rate witnessed rapid depreciation following the outbreak of war in February 2022. The findings suggest a significant deviation from the predicted value and show that the USD/RUB exchange rate consistently remained lower than would have been anticipated in the absence of the conflict. On the other hand, the regression discontinuity method supports the finding that the USD/RUB exchange rate has significantly depreciated after the war. The study indicates that war has increased uncertainty and affects exchange rates, causing a noticeable difference between predicted and actual rates. These findings highlight the significance of contingency planning, efficient disaster management, access to market information, and accurate predictive modeling.
- The heterogeneous effects of motorways on urban sprawl: causal evidence from PortugalPublication . Rocha, Bruno T.; Melo, Patrícia C.; Colaço, Rui; Silva, João de Abreu e; Afonso, NunoAs urban land increased in mainland Portugal by 55.9% between 1990 and 2012 and the country developed an extensive motorway network between the 1980s and the early 2010s, we set out to investigate the effect of motorways on urban sprawl across mainland municipalities. We document the evolution of urban sprawl for these 275 municipalities across several dimensions, including the population density of urban land, its degree of fragmentation and shape irregularity (which we combine in a summary “total interface” indicator), and the differences between the central urban unit and the remaining “peripheral” urban land. Given that the spatial distribution of motorways is likely to be endogenous, we use road itineraries from the 18th century as an instrumental variable. Our results suggest that motorways contributed to the fragmentation of urban land into numerous urban patches. Also, we identify important within-municipality heterogenous effects, in that motorways did not cause the contiguous growth of the central urban unit (typically the largest urban unit in each municipality) but, conversely, appeared to contribute in a significant manner to the development of peripheral urban land. There is also some evidence that motorways contributed to an increase in the shape irregularity of urban areas. Finally, we show that motorways caused a decrease in urban population density, but only in the relatively small group of more urbanised municipalities.
- The ECB’s pandemic emergency purchase programme and fiscal policy: synergies or conflict?Publication . Afonso, António; Ferreira, Jorge BragaWe assess how countries’ fiscal policies during COVID-19 pandemic influenced the effects of the Pandemic Emergency Purchase Programme (PEPP) on sovereign bond Option-Adjusted Spreads. Using a cross-sectional regression model with country and time-fixed effects, we analyse a sample of 1,368 euro-denominated sovereign bonds issued between Q1:2018 and Q1:2022 in 19 Eurozone countries. We consider the PEPP net purchases by country, and the fiscal policy is measured through changes in debt-to-GDP ratio and net lending/borrowing as a percentage of GDP. The results indicate that PEPP’s effectiveness in reducing spreads was strongly conditional on fiscal conditions, and then fiscal fundamentals condition the effectiveness of ECB interventions. In high-debt countries, PEPP did not lower spreads, which suggests that fiscal concerns remained dominant. PEPP was more effective in low-debt countries, but its effects diminished as the level of debt increased, which suggest rising fiscal risks. Furthermore, eligibility status was more important in economies with low debt levels, where eligible bonds were seen as riskier assets. Finally, the results suggests that PEPP’s effectiveness was stronger for higher-rated bonds, longer-maturity bonds, and central government bonds, in fiscally sound countries.
- The devil’s dung? Money as a mechanism of generalized reciprocity in human societiesPublication . Ferraciolli, Eduardo C.; Renzini, Francesco; Araújo, Tanya V.; Squazzoni, FlaminioSt. Francis of Assisi (1181/82-1226) famously called money the devil’s dung, and indeed money is often associated with greed, inequality, and corruption. Drawing on Nowak’s five rules for the evolution of cooperation, we argue here that money promotes the formation of circuits of generalized reciprocity across human groups that are fundamental to social evolution. In an evolutionary tournament, we show that money exchange is an evolutionarily stable strategy that promotes cooperation without relying on the cognitive demands of direct reciprocity or reputation mechanisms. However, we also find that excessive liquidity can be detrimental because it can distort the informational value of money as a signal of past cooperation, making defection more profitable. Our results suggest that, in addition to institutions that promoted trust and punishment, the emergence of institutions that regulated the money supply was key to maintaining generalized reciprocity within and across human groups.
- Innovative pathways to sustainability in injection moulding: a multi-criteria analysis for choosing sustainable plasticsPublication . Boeken, Ina; Lourenço, Tiago CapelaPlastics play a vital role in modern society, but their widespread use poses significant sustainability challenges, particularly in the face of environmental degradation and climate change. Injection moulding, as a core manufacturing process, is central to shaping the future of sustainable plastics production. Innovation strategies, such as the integration of sustainable plastics into injection moulding processes are seen as key to reduce environmental impacts and comply with European sustainability regulations. This study presents a novel decision support framework that facilitates the adoption of sustainable plastic alternatives in injection moulding. A structured literature review informed the development of a multi-criteria analysis tool, which was subsequently applied and tested in the packaging, household appliances and automotive parts sectors. The multi-criteria analysis evaluated five types of alternative plastics based on material properties, sustainability criteria and industrial feasibility. Key findings show that while bioplastics and recycled polymers offer significant environmental benefits, challenges such as data availability, performance trade-offs and infrastructure limitations remain, hindering the full potential of a plastic sustainability transition. The study highlights the need to advance recycling technologies, standardise sustainability assessment tools and foster collaboration between policy makers, scientists and industry leaders. The proposed framework serves as a practical guide for companies, helping them to evaluate plastic alternatives by balancing sustainability goals with technical feasibility. Future research should focus on improving material databases and investigating the economic impact of a transition to sustainable plastics
- Azorean Cryptomeria japonica immature female cones essential oil: Effect of hydrodistillation fractionation on the chemical composition and in vitro antifungal activity against Thielaviopsis paradoxaPublication . Arruda, Filipe; Lima, Ana; Janeiro, Alexandre; Rodrigues, Tânia; Baptista, José; Rosa, José S.; Machado, Alexandra; Figueiredo, Ana Cristina; Lima, ElisabeteCryptomeria japonica's wood production in Azores generates large amounts of underutilized biomass residues, such as immature female cones (Az–CJIFC), that can be used to produce essential oils (EOs). Hydrodistillation (HD) can be used both to obtain and to fractionate EOs. In this study, EOs from Az–CJIFC, grinded (GR) and non-grinded (NGr) fresh samples, were obtained via HD over 4 h, yielding 1.0 % and 0.5 %, w/w, respectively. Thus, GR Az–CJIFC was chosen to obtain six EO fractions (Frs. 1–6), collected at sequential HD timeframes (HDTs: 0–2, 2–10, 10–30, 30–60, 60–120, and 120–240 min). The obtained EO samples (crude EOs and fractions) were evaluated for their chemical composition (GC–FID/GC–MS analyses) and antifungal activity (micro-atmosphere method) against phytopathogenic fungi (Penicillium italicum, P. digitatum and Thielaviopsis paradoxa). Results indicated that all samples were active only towards T. paradoxa, however, with a differential efficacy, due to their specific composition. Fraction 4 vapor treatment displayed the strongest activity, but lower than that of (–)-terpinen-4-ol, a key oxygen-containing monoterpene (OCM) of Az–CJIFC EO, peaking its concentration in Fr3 (14.5 %) and Fr4 (13.8 %). This latter fraction was the richest in the OCM α-terpineol (a minor Az–CJIFC EOs' component). On the other hand, Frs.1–3 and EOs were dominated by monoterpene hydrocarbons (65.0–96.5 %), mainly α-pinene (19.0–28.4 %) and sabinene (19.9–50.5 %), while Frs.5 and 6 were the richest in oxygen-containing sesquiterpenes (47.1–70.8 %; chiefly elemol plus α-, β- and γ-eudesmol) and diterpene hydrocarbons (5.2–6.4 %; mostly phyllocladene). In conclusion, new high value-added products can now be targeted in Az–CJIFC EO by adjusting the HDT, with potential importance in pineapple fruit black rot disease management caused by T. paradoxa on Ananas comosus in the Azores, and also contributing for the local C. japonica’s EO industry development and sustainable circular bio-economy.
- Research on the influence mechanisms of digital economy on tourism economic resilience—empirical evidence from ChinaPublication . Zhou, Min; Chen, Xue-JunIn recent years, the vulnerability of the tourism economy has been highlighted by public security incidents. To ensure high-quality development of the tourism industry, it is crucial to enhance tourism economic resilience (TER). Despite this adverse trend, the digital economy (DE) continues to develop robustly, bringing new vitality to the tourism industry and becoming an important means to enhance its resilience. Based on this, a panel fxed time efect model and a spatial lag model are constructed to study the impact mechanism of the DE on TER. The study fnds that the DE has a signifcant direct positive impact on TER. Moreover, industrial structure optimization, innovation capacity, and human capital stock are all efective mediating mechanisms for the digital economy to enhance TER, and the mediating efect of industrial structure optimization is more obvious. The spatial spillover efect of the DE on TER is negative.
- From subject matter expert to first-time leader: a grounded theory approach on learning challenges for first-time leaders in NorwayPublication . Hendricks, Patrick Fiskaa; Gonçalves, Tiago Emanuel RodriguesThe transition from Subject Matter Expert (SME) to first-time leader is a critical yet underexplored career milestone with significant implications for individual growth and organisational effectiveness. Understanding this transition is essential, as SMEs often face unique challenges when moving into leadership roles, including balancing technical expertise with relational and strategic skills. This research addresses this gap by investigating the learning challenges and strategies experienced by first-time leaders in Norwegian organisations. Employing a grounded theory methodology, this research utilised a qualitative, inductive approach to explore the lived experiences of seven first-time leaders across diverse industries. Semi-structured interviews formed the core of data collection and were analysed through thematic analysis to derive key patterns and themes. The findings reveal three major themes: (1) building relationships and trust, (2) transitioning into leadership, and (3) learning challenges. Candidates emphasised the importance of credibility, active listening, and effective delegation to establish trust and foster collaboration, particularly when managing experienced teams. Experiential learning—through trial and error, reflective practices, and peer feedback—emerged as a primary mechanism for skill development in the absence of structured mentorship and onboarding programs. This research provides actionable insights for organisations seeking to better support first-time leaders by designing tailored development frameworks. It contributes to the academic discourse on leadership transitions by highlighting the complex interplay of technical expertise, interpersonal dynamics, and psychological resilience. Ultimately, the study underscores the transformative potential of transitioning from SME to leadership, offering pathways for enhanced individual and organisational outcomes.
- A mixed approach to the heterogeneity of the short-term rentals’ regulation in SpainPublication . Viana-Lora, Alba; Sánchez-Cubo, FranciscoThis paper aims to analyse the current situation of STRs and their regulation in Spain in order to determine whether the restrictions applied contributed to alleviating the volume of STRs. For this purpose, a database from the experimental statistics on tourist accommodation on houses provided by the National Institute of Statistics of Spain and the regional and municipal regulations on STRs have been used. The upward or downward trends of STRs have been examined and linked to the existing regulation. Then, the municipalities were classifed according to the type of regulatory measure: laissez-faire, limitation or prohibition. The trend and the problems linked to STRs lead us to believe that more and more municipalities will opt to regulate the activity, seeking a balance between the economic beneft and the social impact of tourism.