Browsing by Issue Date, starting with "2023-08"
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- Influence of intensive and super-intensive Olive grove management on soil quality—Nutrients content and enzyme activitiesPublication . Reyes-Martín, Marino Pedro; Fernández-Ondoño, Emilia; Ortiz-Bernad, Irene; Abreu, Maria ManuelaAgricultural soil quality is an issue that has been widely debated in the literature in recent decades. Three olive grove areas (one in Lisbon and the others in Santarém, Portugal) with different management techniques (intensive and super-intensive) were selected. Nutrient concentrations and enzyme activities of soils were determined, as well as the C and N of litter and pruning waste (mulch) to estimate the influence of management techniques on the quality of olive grove soils and to assess the extent to which they are affected by organic covers and different cultivation intensities. Organic C and total N concentrations in soils of the intensive olive grove in Lisbon were the highest when compared with those in the intensive and super-intensive olive groves soils of Santarém. The concentrations of Ca, Mg, Na, and K were the main differences between the Lisbon olive groves and the other two from Santarém. Phosphatase, cellulase, and urease activities were related to the Na, extractable K, extractable P, Zn, Mn, organic C, and total N soil concentrations. Soil management and agricultural practices are determining factors for these enzymatic activities of Santarém olive groves, although climate conditions and soil properties play an important role in the soil enzymatic activities.
- Exploring the multifaceted potential of a peptide fraction derived from Saccharomyces cerevisiae metabolism: antimicrobial, antioxidant, antidiabetic, and anti-inflammatory propertiesPublication . Branco, Patrícia; Maurício, Elisabete Muchagato; Costa, Ana; Ventura, Diogo; Roma-Rodrigues, Catarina; Duarte, Maria Paula; Fernandes, Alexandra R.; Prista, CatarinaThe rising demand for minimally processed, natural, and healthier food products has led to the search for alternative and multifunctional bioactive food components. Therefore, the present study focuses on the functional proprieties of a peptide fraction derived from Saccharomyces cerevisiae metabolism. The antimicrobial activity of the peptide fraction is evaluated against various foodborne pathogens, including Candida albicans, Candida krusei, Escherichia coli, Listeria monocytogenes, and Salmonella sp. The peptide fraction antioxidant properties are assessed using FRAP and DPPH scavenging capacity assays. Furthermore, the peptide fraction’s cytotoxicity is evaluated in colorectal carcinoma and normal colon epithelial cells while its potential as an antidiabetic agent is investigated through -amylase and -glucosidase inhibitory assays. The results demonstrate that the 2–10 kDa peptide fraction exhibits antimicrobial effects against all tested microorganisms, except C. krusei. The minimal inhibitory concentration for E. coli, L. monocytogenes, and Salmonella sp. remains consistently low, at 0.25 mg/mL, while C. albicans requires a higher concentration of 1.0 mg/mL. Furthermore, the peptide fraction displays antioxidant activity, as evidenced by DPPH radical scavenging activity of 81.03%, and FRAP values of 1042.50 32.5 M TE/mL at 1.0 mg/mL. The peptide fraction exhibits no cytotoxicity in both tumor and non-tumoral human cells at a concentration up to 0.3 mg/mL. Moreover, the peptide fraction presents anti-inflammatory activity, significantly reducing the expression of the TNF gene by more than 29.7% in non-stimulated colon cells and by 50% in lipopolysaccharide-stimulated colon cells. It also inhibits the activity of the carbohydrate digestive enzymes -amylase (IC50 of 199.3 0.9 g/mL) and -glucosidase (IC20 of 270.6 6.0 g/mL). Overall, the findings showed that the peptide fraction exhibits antibacterial, antioxidant, anti-inflammatory, and antidiabetic activity. This study represents a step forward in the evaluation of the functional biological properties of S. cerevisiae bioactive peptides.
- Rethinking corporate taxation in the European Union : how and where to tax multinational enterprisesPublication . Vicente, Joana AndradeIn this paper we conduct an empirical analysis to assess the redistributional impact of implementing a Formulary Apportionment approach in the European Union, compared to the current system based on the separate entity approach, aiming to contribute with databased evidence to the ongoing sensitive political debate about the much-needed change in the international (and, specifically, European) corporate tax regime. We update and extend prior research to estimate which Member States will likely gain and lose in terms of corporate tax base and revenues from the implementation of the ‘Business in Europe: Framework for Income Taxation’ (BEFIT) initiative, planned to be soon launched by the European Commission. Using recently published Country-by-Country Reporting data released by the Internal Revenue Service, our findings show that the redistributional impact among Member States would be significant. Results are in line with international tax literature: larger economies with higher tax rates (such as Germany and France) would experience a considerable tax base increase, transferred from smaller countries with lower tax rates (like the Netherlands and Ireland), as multinational enterprises would have more restricted opportunities to engage in artificial profit shifting activities.
- A circular economy approach in the development of superabsorbent Polymeric matrices: evaluation of the mineral retentionPublication . Álvarez-Castillo, Estefanía; Oliveira, Sónia; Bengoechea, Carlos; Sousa, Isabel; Raymundo, Anabela; Guerrero, AntonioThis manuscript focuses on the production of polymeric matrices enriched in minerals and antioxidant compounds. The biopolymers employed are obtained from different by-products of the agro-food industry (porcine plasma protein, pea protein concentrate and soy protein isolate), which helps to revalorize them. Two different manufacturing techniques are employed to produce these matrices: 3D-printing and injection molding. Bioactivity was enhanced through immersion of the samples in magnesium glutamate and iron lactate solutions. To incorporate these minerals and bioactive compounds into the matrices, two additional stages are required: (1) an immersion stage in a mineral/bioactive containing solution, which allows simultaneous removal of the glycerol employed as plasticizer and entrapment of the minerals and bioactive compounds; and (2) a subsequent freezedrying stage. Matrices produced through these manufacturing processes were assessed through water uptake capacity, mineral analysis, bioactivity and color measurements. The studied matrices have great potential in the food industry, as the threshold for claiming a significant mineral content was reached after the immersion stage. The presence of bioactive compounds could avoid the degradation of these matrices when food processing includes stages at relatively high temperatures.
- Tuning the Bioactive Properties of Dunaliella salina Water Extracts by Ultrasound-Assisted ExtractionPublication . Ferreira, Joana P. A.; Grácio, Madalena; Sousa, Isabel; Pagarete, António; Nunes, M. Cristiana; Raymundo, Anabela(1) Background: Microalgae are promising feedstock for obtaining valuable bioactive compounds. To facilitate the release of these important biomolecules from microalgae, effective cell disruption is usually necessary, where the use of ultrasound has achieved considerable popularity as an alternative to conventional methods. (2) Methods: This paper aims to evaluate the use of ultra- sound technology in water medium as a green technology to recover high added-value compounds from Dunaliella salina and improve its sensory profile towards a high level of incorporation into novel food products. (3) Results: Among the variables, the solid concentration and extraction time have the most significant impact on the process. For the extraction of protein, or fat, the most influential factor is the extraction time. Total polyphenols are only significantly affected by the extraction time. The antioxidant capacity is strongly affected by the solid to liquid ratio and, to a small extent, by the extraction time. Ultrasound-assisted extraction improves the overall odor/aroma of D. salina with good acceptability by the panelists. (4) Conclusions: The application of ultrasonic-assisted extraction demonstrates a positive overall effect on enhancing the sensory profile, particularly the odor of microalgal biomass, while the bioactive properties are preserved. Notably, the intense sea/fish odors are reduced, while earthy and citrus notes become more prominent, resulting in an improved overall sensory profile score. This is the first time, to our knowledge, that this innovative, green, and efficient technology has been used to upgrade the aroma profile of microalgae.
- No evidence of inbreeding depression despite a historical severe bottleneck in the endangered Bermuda petrel (Pterodroma cahow)Publication . Afonso, Rita O; Pina-Martins, Francisco; Friesen, Vicki; Sun, Zhengxin; Campioni, Letizia; Madeiros, Jeremy; Silva, Mónica CThe Bermuda petrel Pterodroma cahow is an island endemic seabird that belongs to the Procellariiformes, one of the most endangered orders of birds. Historical records suggest a significant population size decline following human settlement in Bermuda, bringing the species to near extinction. Since the 1950s, the population has been recovering aided by the implementation of an ongoing conservation plan. However, it still faces several threats, and negative genetic effects resulting from that drastic decline are to be expected, including inbreeding and genetic drift. We studied genetic diversity and levels of inbreeding, and their effects on individual fitness and mating choice. We also tested for a genetic signature of the recent demographic bottleneck. For this, we analyzed variation in thousands of nuclear single-nucleotide polymorphisms derived from double digest restriction site-associated DNA sequencing and 1 mitochondrial gene (cytochrome oxidase I). The results revealed that the Bermuda petrel suffered a recent genetic bottleneck and shows low mitochondrial diversity compared with other petrel species. Conversely, nuclear diversity was similar to that of other endangered petrels. Inbreeding levels were not high overall, although some individuals were highly inbred. However, we found no evidence that individual inbreeding or relatedness between mates affected hatching success, or that mate choice is influenced by kinship in this very small population.
- Insights into the habitat associations, phylogeny, and diet of Pipistrellus maderensis in Porto Santo, northeastern MacaronesiaPublication . Nóbrega, Eva K.; Toshkova, Nia; Gonçalves, Angelina; Reis, André; Soto, Elena J.; Ruiz, Sergio Puertas; Mata, Vanessa A.; Rato, Catarina; Rocha, RicardoAround 60% of all bat species occur in islands, and nearly one in four is an insular endemic. Bats are often the only native terrestrial mammals in oceanic islands, and despite increasing anthropogenic pressures, little is known about the distribution, natural history, and population status of most insular bat populations. The sub-tropical archipelago of Madeira is composed of the volcanic islands of Madeira, Porto Santo, and Desertas and is home to the Macaronesian endemic Pipistrellus maderensis, to the endemic subspecies Nyctalus leisleri verrucosus, and to Plecotus austriacus. Pipistrellus maderensis is known to both Madeira and Porto Santo, whereas the other two species have only been recorded in the former. However, no bats have been recorded in Porto Santo for over 15 years, raising fears that bats are probably extinct in the island. In July 2021, we conducted an island-wide acoustic survey using AudioMoth passive acoustic recorders, leading to the detection of Pipistrellus maderensis in 28 out of the 46 sampling sites (60 %). The species’ activity was strongly associated with artificial water sources, and genetic samples from six captured individuals revealed that the populations of Pipistrellus maderensis in Porto Santo and Madeira have a close phylogenetic affinity. Furthermore, using DNA metabarcoding, we found that the species feeds on a wide variety of insects, including several economically important pest species and disease vectors. These findings emphasise the need to target more conservation and research efforts towards extant island bat populations and the potential ecosystem services they provide.
- Unravelling relationships between in vivo effects on plants and detected pesticide mixtures in freshwaters of a South-European agro-ecosystemPublication . Silva, Emília; Narciso, Guilherme Anágua; Castro, Joel CarvalhoThe multiple benefits agriculture provides to society depend on the long-term sustainable management of water resources, including the preservation of a good ecological and good chemical status of the water bodies. Presently, this good chemical status has not been reached in the majority of European river basins. Implemented monitoring strategies are targeted to identify the presence and magnitude of the ecological impacts that come from mixtures of chemicals but fail to give information on the causes of the ecosystem disruptions. This work aims to contribute to assessing the quality of surface waters used for irrigation in the LGVFX agricultural area (Central Portugal) by applying non-conventional in vivo phytotoxicity tests on three primary producers, a monocotyledon (Sorghum saccharatum) and two dicotyledons (Lepidium sativum and Sinapsis alba), complemented by chemical screening and mixture-risk modelling with component-based methods (summation of risk quotients) based on the classic concept of concentration addition (CA). Although inhibition percentages of the phytotoxicity parameter germination and root and shoot growth may be related to the presence of mixtures of pesticides, it was not possible to establish the fingerprinting of the detected compounds with the observed biological effects, mostly due to the large gap of ecotoxicological data on terrestrial plants exposed to contaminated water. In addition, pesticides can interact within the plant, leading to antagonism and synergism phenomena.
- Multitemporal land use and cover analysis coupled with climatic change scenarios to protect the endangered Taxon Asphodelus bento-rainhae subsp. bento-rainhaePublication . Almeida, Alice Maria; Delgado, Fernanda; Roque, Natália; Ribeiro, Maria Margarida; Fernandez, PauloClimate change and land use and land cover (LULC) change are impacting the species’ geographic distribution, causing range shifts and reducing suitable habitats. Asphodelus bento-rainhae subsp. bento-rainhae (AbR) is an endangered endemic plant restricted to Serra da Gardunha (Portugal), and knowledge of those changes will help to design conservation measures. MaxEnt was used to model AbR’s current distribution and project it into the future, 2050, using the Shared Socioeconomic Pathway SSP3-7. The Portuguese LULC maps from 1951–1980, 1995, 2007, and 2018 were used to assess and quantify LULC changes over time. The results showed that the AbR current predicted distribution matches its actual known distribution, which will not be affected by future predicted climate change. The significant LULC changes were observed during the study periods 1951–1980 to 2018, particularly between 1951–1980 and 1995. Scrubland and Agriculture decreased by 5% and 2.5%, respectively, and Forests increased by 4% in the study area. In the occurrence area, Agriculture increased, and Forests decreased between 1980 and 2018, due to Orchard expansion (34%) and declines in Chestnut (16.9%) and Pine (11%) areas, respectively. The use of species distribution models and the LULC change analysis contributed to understanding current and future species distribution. The LULC changes will have a significant impact on future species distribution. To prevent the extinction of this endemic species in the future, it is crucial to implement conservation measures, namely species monitoring, replantation, and germplasm conservation, in addition to guidelines for habitat conservation.
- Tipos de despesa pública e crescimento económico o caso de Angola (2002-2020)Publication . Andrade, Valter Rossano Gambôa de; Escária, VitorNesta dissertação analisamos a relação de causalidade dinâmica entre diferentes tipos de despesa pública e crescimento económico. Para o cumprimento deste objetivo, o estudo utilizou séries temporais das diferentes rubricas da despesa pública angolana, recorremos ao teste de causalidade à Granger para identificar a relação de causalidade entre as diferentes tipologias de despesas pública e o PIB. A abordagem de Autoregressão Vetorial (VAR) foi também utilizada, permitindo modelar os dados em três modelos distintos e realizar testes dinâmicos como a decomposição da variância e funções de impulso-resposta (FIR). Os resultados apontam para um contributo significativo da despesa realizada com o setor da Comunicação e Tecnologia de Informação sobre o crescimento económico. Por outro lado constatamos que um choque na despesa com o setor da saúde apresenta um efeito praticamente nulo sobre o crescimento económico e choques na despesa com setor da indústria (extrativa e transformadora) e construção e agricultura produzem efeitos oscilantes sobre o produto e que se dissipam ao longo do tempo.