Browsing by Issue Date, starting with "2022"
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- Cauchy problem for the Navier–Stokes–Voigt model governing nonhomogeneous flowsPublication . Antontsev, S. N.; Oliveira, H. B. deThe Navier-Stokes-Voigt model that governs flows with non-constant density of incompressible fluids with elastic properties is considered in the whole space domain R-d and in the entire time interval. If d is an element of{2,3,4}, we prove the existence of weak solutions (velocity, density and pressure) to the associated Cauchy problem. We also analyse some issues of regularity of the weak solutions to the considered problem and the large time behavior in special unbounded domains.
- Corrigendum to “Visitor preferences and satisfaction in Attica zoological park, Greece” [Heliyon 9 (9) (September 2020) e04935]Publication . Karanikola, Paraskevi; Panagopoulos, Thomas; Tampakis, Stilianos; Tampakis, AntoniosIn the original published version of this article, there were 2 minor typos in the Abstract and Conclusion sections, which reversed the intended meaning of these statements.
- Opuntia ficus indica waste as a cost effective carbon source for lactic acid production by Lactobacillus plantarumPublication . Derabli, Besma; Nancib, Aicha; Nancib, Nabil; Aníbal, Jaime; Raposo, Sara; Rodrigues, Brígida; Boudrant, JosephOpuntia ficus indica (OFI) waste was evaluated as a fermentation feedstock for lactic acid production using Lactobacillus plantarum. Dilute acid pretreatment of the OFI cladodes (OFIC) was performed for extracting maximum fermentable sugars by optimizing process parameters using statistical optimization method. The best results were obtained with HCl 1% (v/v), temperature 120 ◦C, residence time 40 min, granulation 350 μm and substrate loading 5% (w/v), the sugar concentration reached 24 g/L with low concentration of hydroxymethylfurfural. The feasibility of producing lactic acid from OFI fruit peel (OFIFP) as a source of carbon was also investigated. Lactobacillus plantarum was shown to have a capacity for lactic acid production from OFIC350 (granulation 350 μm) hydrolysate and OFIFP extract without detoxification. The highest lactic acid yields of 0.46 and 0.78 g/g were obtained from enzymatic hydrolysate of pretreated OFIC350 and OFIFP extract, respectively.
- A global synthesis of ecosystem services provided and disrupted by freshwater bivalve molluscsPublication . Zieritz, Alexandra; Sousa, Ronaldo; Aldridge, David C.; Douda, Karel; Esteves, Eduardo; Ferreira-Rodriguez, Noe; Mageroy, Jon H.; Nizzoli, Daniele; Osterling, Martin; Reis, Joaquim; Riccardi, Nicoletta; Daill, Daniel; Gumpinger, Clemens; Vaz, Ana SofiaIdentification of ecosystem services, i.e. the contributions that ecosystems make to human well-being, has proven instrumental in galvanising public and political support for safeguarding biodiversity and its benefits to people. Here we synthesise the global evidence on ecosystem services provided and disrupted by freshwater bivalves, a heterogenous group of >1200 species, including some of the most threatened (in Unionida) and invasive (e.g. Dreissena polymorpha) taxa globally. Our systematic literature review resulted in a data set of 904 records from 69 countries relating to 24 classes of provisioning (N = 189), cultural (N = 491) and regulating (N = 224) services following the Common International Classification of Ecosystem Services (CICES). Prominent ecosystem services included (i) the provisioning of food, materials and medicinal products, (ii) knowledge acquisition (e.g. on water quality, past environments and historical societies), ornamental and other cultural contributions, and (iii) the filtration, sequestration, storage and/or transformation of biological and physico-chemical water properties. About 9% of records provided evidence for the disruption rather than provision of ecosystem services. Synergies and trade-offs of ecosystem services were observed. For instance, water filtration by freshwater bivalves can be beneficial for the cultural service ‘biomonitoring’, while negatively or positively affecting food consumption or human recreation. Our evidence base spanned a total of 91 genera and 191 species, dominated by Unionida (55% of records, 76% of species), Veneroida (21 and 9%, respectively; mainly Corbicula spp.) and Myoida (20 and 4%, respectively; mainly Dreissena spp.). About one third of records, predominantly from Europe and the Americas, related to species that were non-native to the country of study. The majority of records originated from Asia (35%), with available evidence for 23 CICES classes, as well as Europe (29%) and North America (23%), where research was largely focused on ‘biomonitoring’. Whilst the earliest record (from 1949) originated from North America, since 2000, annual output of records has increased rapidly in Asia and Europe. Future research should focus on filling gaps in knowledge in lesser-studied regions, including Africa and South America, and should look to provide a quantitative valuation of the socio-economic costs and benefits of ecosystem services shaped by freshwater bivalves.
- Relatório final do estudo para a criação do Núcleo Museológico da Antiga Tipografia União (Faro, Algarve)Publication . Gonçalves, Alexandra; Palma, Patrícia de JesusRelatório das atividades desenvolvidas no âmbito do estudo científico de investigação, conceptualização e adequação dos espaços da extinta Tipografia União a espaço museológico dedicado à imprensa, no âmbito do contrato n.º 35/2021, celebrado pela Câmara Municipal de Faro e a Universidade do Algarve, a 26 de maio de 2021.
- A letra da tabuleta do cronista José SaramagoPublication . Carmo, CarinaDefende Saulo Gomes Thimóteo que a obra cronística de José Saramago, "não deve ser vista como prenúncio do romancista a haver, mas sim como uma espécie de umbra futurorum que reverberaria por toda a produção saramaguiana, uma vez que é o autor empreendendo sua busca questionadora".
- Decavanadate and metformin-decavanadate effects in human melanoma cellsPublication . de Sousa-Coelho, Ana Luísa; Aureliano, Manuel; Fraqueza, Gil; Serrão, Gisela; Gonçalves, João; Sánchez-Lombardo, Irma; Link, Wolfgang; Ferreira, BibianaDecavanadate is a polyoxometalate (POMs) that has shown extensive biological activities, including antidiabetic and anticancer activity. Importantly, vanadium-based compounds as well as antidiabetic biguanide drugs, such as metformin, have shown to exert therapeutic effects in melanoma. A combination of these agents, the metformin-decavanadate complex, was also recognized for its antidiabetic effects and recently described as a better treatment than the monotherapy with metformin enabling lower dosage in rodent models of diabetes. Herein, we compare the effects of decavanadate and metformin-decavanadate on Ca2+-ATPase activity in sarcoplasmic reticulum vesicles from rabbit skeletal muscles and on cell signaling events and viability in human melanoma cells. We show that unlike the decavanadate-mediated non-competitive mechanism, metformin-decavanadate inhibits Ca2+-ATPase by a mixed-type competitive-non-competitive inhibition with an IC50 value about 6 times higher (87 mu M) than the previously described for decavanadate (15 mu M). We also found that both decavanadate and metformin-decavanadate exert antiproliferative effects on melanoma cells at 10 times lower concentrations than monomeric vanadate. Western blot analysis revealed that both, decavanadate and metformin-decavanadate increased phosphorylation of extracellular signal-regulated kinase (ERK) and serine/ threonine protein kinase AKT signaling proteins upon 24 h drug exposure, suggesting that the anti-proliferative activities of these compounds act independent of growth-factor signaling pathways.
- Quantifying dominant bacterial genera detected in metagenomic data from fish eggs and larvae using genus‐specific primersPublication . Najafpour, Babak; Pinto, Patricia; Canario, Adelino; Power, DeborahThe goal of this study was to design genus-specific primers for rapid evaluation of the most abundant bacterial genera identified using amplicon-based sequencing of the 16S rRNA gene in fish-related samples and surrounding water. Efficient genus-specific primers were designed for 11 bacterial genera including Alkalimarinus, Colwellia, Enterovibrio, Marinomonas, Massilia, Oleispira, Phaeobacter, Photobacterium, Polarbacerium, Pseudomonas, and Psychrobium. The specificity of the primers was confirmed by the phylogeny of the sequenced polymerase chain reaction (PCR) amplicons that indicated primers were genus-specific except in the case of Colwellia and Phaeobacter. Copy number of the 16S rRNA gene obtained by quantitative PCR using genus-specific primers and the relative abundance obtained by 16S rRNA gene sequencing using universal primers were well correlated for the five analyzed abundant bacterial genera. Low correlations between quantitative PCR and 16S rRNA gene sequencing for Pseudomonas were explained by the higher coverage of known Pseudomonas species by the designed genus-specific primers than the universal primers used in 16S rRNA gene sequencing. The designed genus-specific primers are proposed as rapid and cost-effective tools to evaluate the most abundant bacterial genera in fish-related or potentially other metagenomics samples.
- Early experiments on automatic annotation of Portuguese medieval textsPublication . Bico, Maria Inês; Baptista, Jorge; Batista, Fernando; Cardeira, EsperançaThis paper presents the challenges and solutions adopted to the lemmatization and part-of-speech (PoS) tagging of a corpus of Old Portuguese texts (up to 1525), to pave the way to the implementation of an automatic annotation of these Medieval texts. A highly granular tagset, previously devised for Modern Portuguese, was adapted to this end. A large text (similar to 155 thousand words) was manually annotated for PoS and lemmata and used to train an initial PoS-tagger model. When applied to two other texts, the resulting model attained 91.2% precision with a textual variant of the same text, and 67.4% with a new, unseen text. A second model was then trained with the data provided by the previous three texts and applied to two other unseen texts. The new model achieved a precision of 77.3% and 82.4%, respectively.
- Plant‐based diets fed to juvenile meagre Argyrosomus regius with low methionine and taurine supplementation led to an overall reduction in fish performance and to an increase in muscle fibre recruitmentPublication . Saavedra, Margarida; Pereira, Teresa G.; Barata, Marisa; Aragão, Cláudia; Requeijo, Bárbara; Conceição, Luís E.C.; Pousão‐Ferreira, PedroMethionine and taurine are amino acids (AA) that are usually deficient when fish meal is replaced by plant proteins. In this study, three diets were tested in juvenile meagre (initial weight: 13.4 g) for 8 weeks. The D1 diet had 0.2% methionine and 1% taurine supplementation; the D2 and D3 diets had 0.6% methionine and 1% and 2% taurine supplementation, respectively. The results showed that meagre fed the D1 diet had lower specific growth rate (2.2 to 2.5), lower feed efficiency (0.9 to 1.2) and higher food conversion rate (FCR, 1.1 to 0.8) as well as a lower activity of the alanine aminotransferase (ALAT) enzyme. Furthermore, a higher recruitment of muscle fibres (46% compared to 36%) as well as a higher fibre density was observed (1019 compared to 870 fibres mm(-2)). This study shows that meagre requires a sufficient quantity of methionine in plant-based diets to avoid a reduction in fish performance. Furthermore, taurine supplementation in the D1 diet was not able to mitigate the effects of methionine deficiency. A higher taurine supplementation did not improve meagre performance.