Browsing by Issue Date, starting with "2023-09"
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- Piece‐wise constant cluster modelling of dynamics of upwelling patternsPublication . Nascimento, Susana; Martins, Alexandre; Relvas, Paulo; Luis, Joaquim; Mirkin, BorisA comprehensive approach is presented to analyse season's coastal upwelling represented by weekly sea surface temperature (SST) image grids. Our three-stage data recovery clustering method assumes that the season's upwelling can be divided into shorter periods of stability, ranges, each to be represented by a constant core and variable shell parts. Corresponding clustering algorithms parameters are automatically derived by using the least-squares clustering criterion. The approach has been successfully applied to real-world SST data covering two distinct regions: Portuguese coast and Morocco coast, for 16 years each.
- Curiosity saved the cat: socio-emotional skills mediate the relationship between parental support and career explorationPublication . GAMBOA, VITOR; Rodrigues, Suzi; Bértolo, Filipa; Marcelo, Beatriz; Paixão, OlímpioAccording to career literature, greater parental support seems to be associated with higher levels of career exploration. This relationship may be mediated by self-regulatory processes, such as social-emotional skills, as curiosity. However, despite the large number of empirical studies that analyze the antecedents of career exploration, there are no references, to our knowledge, to the role of socio-emotional skills. Following this gap, the present study aims to examine the extent to which perceived parental support is associated with career exploration through the mediating effect of curiosity (socio-emotional skill), among a group of 8th and 9th grade students from public schools in southern Portugal (N = 540). An integrated model was conducted using AMOS 20.0 and the results revealed that curiosity is a partial mediator of the relationship between perceived parental support and career exploration. These results highlight the importance of considering socio-emotional skills (such as curiosity) when designing interventions to foster adaptive career behaviors. Theoretical and practical implications are discussed to open the opportunity to progressively extend the participation of proximal contexts (e.g., families) to career and socio-emotional skills development processes.
- Engineering novel phenolic foams with lignin extracted from pine wood residues via a new levulinic-acid assisted processPublication . Melro, Elodie; Duarte, Hugo; Antunes, Filipe E.; Valente, Artur J.M.; Romano, Anabela; Norgren, Magnus; Medronho, BrunoPhenolic foams are typically produced from phenolic resins, using phenol and formaldehyde precursors. Therefore, common phenolic foams are non-sustainable, comprising growing environmental, health, and economic concerns. In this work, lignin extracted from pine wood residues using a "green" levulinic acid-based solvent, was used to partially substitute non-sustainable phenol. The novel engineered foams were systematically compared to foams composed of different types of commercially available technical lignins. Different features were analyzed, such as foam density, microstructure (electron microscopy), surface hydrophilicity (contact angle), chemical grafting (infrared spectroscopy) and mechanical and thermal features. Overall, it was observed that up to 30 wt% of phenol can be substituted by the new type of lignin, without compromising the foam properties. This work provides a new insights on the development of novel lignin-based foams as a very promising sustainable and renewable alternative to petrol-based counterparts.
- Incised valleys on the Algarve inner shelf, northern Gulf of Cadiz margin: stratigraphic architecture and controlling factors in a low fluvial supply settingPublication . Carrión-Torrente, Álvaro; Lobo, Francisco José; Puga-Bernabéu, Ángel; Luján, María; Mendes, Isabel; Hanebuth, Till J. J.; Lebreiro, Susana; García, Marga; Reguera, María Isabel; Antón, Laura; Van Rooij, David; Cerrillo-Escoriza, JavierA network of cross-shelf paleovalleys has been recognized over the paleo-inner shelf off the Gila & SIM;o-Almargem Estuary, a small fluvial drainage system that presently receives minor sediment supply in the eastern Algarve shelf, northern margin of the Gulf of Cadiz (SW Iberian Peninsula). This study is aimed at determining the driving controls that triggered substantially different paleohydrological conditions and sedimentary dynamics of ancient fluvial systems in this margin. We focus on evidences of secondary controls on valley genesis and evolution, superimposed to primary glacio-eustatic control such as antecedent geology, low fluvial supply and changing hydrodynamic regimes. The architecture and spatial distribution of these paleovalleys were interpreted based on a grid of seismic profiles with different resolutions. Likewise, a sediment core obtained in a distal position of the paleovalley system provided information about sedimentary processes during the most recent stage of valley infilling. The chronostratigraphic framework was constructed based on regional seismic horizons defined in previous studies and complemented with two AMS 14C dates obtained from bivalve shells.The inner shelf paleovalley system is composed of several incised valley features which exhibit a remarkable similar internal architecture. These inner valley features exhibit two major incision phases (from oldest to youngest; IP 2 and IP 1) that are thought to constitute a simple paleovalley system formed during the last glacial cycle. The origins of the incision are considered to be different. The older one is related to fluvial incision during the sea-level fall leading into the Last Glacial Maximum, whereas the recent one is interpreted as the result of tidal scour during the postglacial transgression. Their corresponding infillings are interpreted, respectively, as estuarine bay-fill deposits and estuary-mouth sands. Overlying the paleovalley infilling, a distinctive reflective unit is in agreement with the generation of coastal barriers and related depositional systems.The formation of the paleo-inner-shelf paleovalley system was strongly conditioned by antecedent geology, which strongly limited the generation of wide incised valleys and determined the amount of incision landward of a well-defined break of slope. Its postglacial infilling was mainly estuarine in nature, likely involving the development of a dendritic system, with numerous barriers interrupted by tidal inlets and channels in a mixed estuarine system with low fluvial supply.
- A global and comparative assessment of the level of economic circularity in the EUPublication . Martínez Moreno, María Magdalena; Buitrago, Eva M.; Yñiguez, Rocío; Puig-Cabrera, MiguelThe European Union (EU) stands as one of the pioneering areas worldwide in the planning of the Circular Economy (CE), despite the fact that practical advances in this area are currently ahead of the related research. Significant gaps remain to be filled, particularly with regard to the measurement of circularity. This work is based on the need for global tools to measure the circular transition which, in turn, can be useful in evaluating the implementation of the action plans under development by the EU. A composite index of economic circularity (CECI) has been built for the EU and its Member States with which to approximate the progress after completion of the first Action Plan for the Circular Economy (APCE): 2014-2020. This index is based on recycling and downcycling, which is the main strategy developed by APCE. In contrast to previous indicators, CECI globally and rigorously summarises the transition towards the circular economy throughout the period of validity of the plan, by using a simple and easy-to-interpret calculation methodology known as Principal Component Analysis. Likewise, the results of the CECI make it possible to establish a ranking of the EU Member States based on their CE performances for each year under consideration. The results of the CECI show that the EU as a whole has advanced in economic circularity by 17.9%, which is almost 3% on average per year. The situation is very uneven across the various Member States and, although differences have narrowed during the APCE period, in recent years this rapprochement has deaccelerated. The countries that continue to lead the circular transition of the EU are the Netherlands, Belgium, and Germany, while trailing behind are Romania, Malta, and Cyprus. In light of the results of the CECI and with the aim of achieving greater convergence in the transition to economic circularity in the EU, it would be advisable to intensify actions in those Member States whose starting situation is comparatively worse.
- Effects of ocean warming and pollution on Sargassum forestsPublication . Peres, Letícia M. Costa; Gouvêa, Lidiane; Hayden, Juliana; Burle, Giulia; Bastos, Eduardo; Carneiro, Alessandra; Horta, Paulo A.The combined effects of climate change and ocean pollution have resulted in a noteworthy decline of canopyforming species, impacting marine biodiversity and ecosystem functioning significantly. In this context, Sargassum cymosum, which is widely distributed along the southwestern Atlantic Ocean, serves as an excellent model among canopy-forming species to investigate these impacts on populations in different regions and environmental conditions. Here, we evaluate the ecophysiological responses of two populations of S. cymosum, from Florianopolis (warm-temperate province; WTP) and Fernando de Noronha (tropical province, TP), through of interaction of temperatures and nutrient concentrations, representing marine heatwaves and acute pollution levels. Our findings revealed a decrease in biomass in both populations, highlighting the significance of nutrient enrichment as an anthropogenic filter that might potentially inhibit the expansion of the populations from tropical regions and temperature for WTP ones. These stressors directly impacted the physiological performance of S. cymosum populations, including relative growth rates, photosynthesis, chlorophylls, carotenoids and phenolic compound levels. Although there was an increase in both parameters for the TP population, a significant loss of biomass was observed, with growth rates reaching -1.5% per day. Our results highlight the need for urgent actions to manage the eutrophication process due to its negative association with global warming, which can enhance the impacts and preclude the settlement and survival of Sargassum in warm-temperate areas considering the observed and predicted tropicalization process.
- Ioxynil and diethylstilbestrol impair cardiac performance and shell growth in the mussel Mytilus coruscusPublication . Li, Yi-Feng; Lin, Yue-Tong; Wang, Yu-Qing; Ni, Ji-Yue; Power, DeborahThe herbicide ioxynil (IOX) and the synthetic estrogen diethylstilbestrol (DES) are environmentally relevant contaminants that act as endocrine disruptors (EDCs) and have recently been shown to be cardiovascular disruptors in vertebrates. Mussels, Mytilus coruscus, were exposed to low doses of IOX (0.37, 0.037 and 0.0037 mg/ L) and DES (0.27, 0.027 and 0.0027 mg/L) via the water and the effect monitored by generating whole animal transcriptomes and measuring cardiac performance and shell growth. One day after IOX (0.37 and 0.037 mg/L) and DES (0.27 and 0.027 mg/L) exposure heart rate frequency was decreased in both groups and 0.27 mg/L DES significantly reduced heart rate frequency with increasing time of exposure (P < 0.05) and no acclimatization occurred. The functional effects were coupled to significant differential expression of genes of the serotonergic synapse pathway and cardiac-related genes at 0.027 mg/L DES, which suggests that impaired heart function may be due to interference with neuroendocrine regulation and direct cardiac effect genes. Multiple genes related to detoxifying xenobiotic substances were up regulated and genes related to immune function were down regulated in the DES group (vs. control), indicating that detoxification processes were enhanced, and the immune response was depressed. In contrast, IOX had a minor disrupting effect at a molecular level. Of note was a significant suppression (P < 0.05) by DES of shell growth in juveniles and lower doses (< 0.0027 mg/L) had a more severe effect. The shell growth depression in 0.0027 mg/L DES-treated juveniles was not accompanied by abundant differential gene expression, suggesting that the effect of 0.0027 mg/L DES on shell growth may be direct. The results obtained in the present study reveal for the first time that IOX and DES may act as neuroendocrine disrupters with a broad spectrum of effects on cardiac performance and shell growth, and that DES exposure had a much more pronounced effect than IOX in a marine bivalve.
- Changing webs—Variation of complex networks over a tidal cycle in an intertidal rocky reefPublication . Vinagre, Catarina; Mendonça, VanessaIncorporating temporal variation in models is one of the most important challenges in food web research. One of the environments where time causes profound changes is the intertidal zone, where the immersion-emersion cycle drastically changes the abiotic and biotic conditions. Intertidal rocky shores have been intensively studied, however the variation in the complex food web network that occurs during a tidal cycle remains undescribed. Highly resolved food web networks were assembled for an intertidal reef depicting the food web during low and high tide, and with and without tide pools. It was concluded that high tide adds new species to the web, but it does not add complexity since network connectance was not changed. This occurs because incoming species are mostly highly generalist fish, which add many new links to the web. Tide pools, however, add not only diversity but also complexity. Webs were dominated by intermediate species, with the proportion of top consumers fluctuating throughout the tidal cycle, being lowest during low tide and highest at high tide, due to the incoming larger vertebrate predators. Consumer taxa outnumbered resource taxa, except at low tide when pools are present. Mean trophic level was lowest at low tide (2.3) and highest at high tide with pools (2.6). Omnivory was high and showed little change. "Chain", the number of links connecting top to basal species, was stable but low. This implies that disturbance can rapidly travel bottom-up or top-down through predator-prey links. The increased connectance given by the addition of tide pools likely increases robustness to disturbances, an important feature in coastal areas so often impacted by human action.
- Levelling-up rhodolith-bed science to address global-scale conservation challengesPublication . Tuya, Fernando; Schubert, Nadine; Aguirre, Julio; Basso, Daniela; Bastos, Eduardo O.; Berchez, Flávio; Bernardino, Angelo F.; Bosch, Néstor E.; Burdett, Heidi L.; Espino, Fernando; Fernández-Gárcia, Cindy; Francini-Filho, Ronaldo B.; Gagnon, Patrick; Hall-Spencer, Jason M.; Haroun, Ricardo; Hofmann, Laurie C.; Horta, Paulo A.; Kamenos, Nicholas A.; Le Gall, Line; Magris, Rafael A.; Martin, Sophie; Nelson, Wendy A.; Neves, Pedro; Olivé, Irene; Otero-Ferrer, Francisco; Peña, Viviana; Pereira-Filho, Guilherme H.; Ragazzola, Federica; Rebelo, Ana Cristina; Ribeiro, Cláudia; Rinde, Eli; Schoenrock, Kathryn; Silva, João; Sissini, Marina N.; Tâmega, Frederico T. S.Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mit-igation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp for-ests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and eco-system services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.
- Identification of hub genes in digestive system of mandarin fish (Siniperca chuatsi) fed with artificial diet by weighted gene co-expression network analysisPublication . Shen, Yawei; Song, Lingyuan; Chen, Tiantian; Jiang, Hewei; Yang, Guokun; Zhang, Yanmin; Zhang, Xindang; Lim, Kah Kheng; Meng, Xiaolin; Zhao, Jinliang; Chen, XiaowuMandarin fish (Siniperca chuatsi) is a carnivorous freshwater fish and an economically important species. The digestive system (liver, stomach, intestine, pyloric caecum, esophagus, and gallbladder) is an important site for studying fish domestication. In our previous study, we found that mandarin fish undergoes adaptive changes in histological morphology and gene expression levels of the digestive system when subjected to artificial diet domestication. However, we are not clear which hub genes are highly associated with domestication. In this study, we performed WGCNA on the transcriptomes of 17 tissues and 9 developmental stages and combined differentially expressed genes analysis in the digestive system to identify the hub genes that may play important functions in the adaptation of mandarin fish to bait conversion. A total of 31,657 genes in 26 samples were classified into 23 color modules via WGCNA. The modules midnightblue, darkred, lightyellow, and darkgreen highly associated with the liver, stomach, esophagus, and gallbladder were extracted, respectively. Tan module was highly related to both intestine and pyloric caecum. The hub genes in liver were cp, vtgc, c1in, c9, lect2, and klkb1. The hub genes in stomach were ghrl, atp4a, gjb3, muc5ac, duox2, and chia2. The hub genes in esophagus were mybpc1, myl2, and tpm3. The hub genes in gallbladder were dyst, npy2r, slc13a1, and slc39a4. The hub genes in the intestine and pyloric caecum were slc15a1, cdhr5, btn3a1, anpep, slc34a2, cdhr2, and ace2. Through pathway analysis, modules highly related to the digestive system were mainly enriched in digestion and absorption, metabolism, and immune-related pathways. After domestication, the hub genes vtgc and lect2 were significantly upregulated in the liver. Chia2 was significantly downregulated in the stomach. Slc15a1, anpep, and slc34a2 were significantly upregulated in the intestine. This study identified the hub genes that may play an important role in the adaptation of the digestive system to artificial diet, which provided novel evidence and ideas for further research on the domestication of mandarin fish from molecular level.