Browsing by Issue Date, starting with "2020-06"
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- How do external openness and R&D activity influence open innovation management and the potential contribution of social media in the tourism and hospitality industry?Publication . Iglesias-Sanchez, Patricia P.; Lopez-Delgado, Pilar; Correia, Marisol B.; Jambrino-Maldonado, CarmenThis research focuses on how the tourism and hospitality industry is applying the paradigm of open innovation, supported by social media. Open innovation (OI) has been on the topical research agenda, but the previous literature lacks studies in the service sector and specifically for tourism companies. Moreover, the introduction of social media as a tool to implement open innovation is considered the main research gap. Structural equation modelling is applied to data from 181 Portuguese and Spanish companies to study both customer involvement in new product development and the perceptions and results in terms of turnover and competitiveness. The structure of the relationships between research and development, external openness and open innovation management is highlighted with statistical analysis. In addition, the introduction of social media adds value to the proposed model. Currently, there is a lack of available models to give structure to the OI paradigm and to allow us to manage it. The contribution of this research is a comparison of the explanatory power of three models that allow us to test how certain strategic guidelines in tourism companies influence each other and have a mediating or multiplier effect when linked to each other (nested models method). In conclusion, the originality of this research is based on the relationship between open innovation management and social media and the mediating effect of external openness.
- Species-specific plastic accumulation in the sediment and canopy of coastal vegetated habitatsPublication . R Nicastro, Katy; Zardi, Gerardo I.; de los Santos, Carmen B.Plastic waste has become ubiquitous in ecosystems worldwide. Few, recent studies report evidence of coastal vegetated habitats acting as sink for plastics, yet assessments have been completed either for macro or microplastics and focussing on just one type of vegetated habitat. Here, we investigated the role of marine coastal vegetated habitats as sinks for macro (≥5 mm) and microplastics (<5 mm) through a comprehensive, multi-habitat approach. We assessed the occurrence, abundance and physical properties of macro and microplastics in the canopy and superficial sediment of two intertidal (seagrass Zostera noltei, saltmarsh Sporobolus maritimus) and two subtidal (mixed seagrass meadows of Cymodocea nodosa and Zostera marina, rhizophytic macroalga Caulerpa prolifera) habitats in the Ria Formosa lagoon (Portugal). Our results showed that coastal vegetated habitats trapped macro and microplastics in the sediment at variable degrees (1.3-17.3 macroplastics 100 m-2, and 18.2-35.2 microplastics kg-1). Macroplastics accumulated in all vegetated habitat but not in nearby unvegetated areas, yet only S. maritimus habitat presented a significant trapping effect. Microplastics occurred in the sediment of all vegetated and unvegetated areas with similar abundances and high variability. Microplastics, all of type fibre, were recorded on all canopies except for S. maritimus. Overall, the trapping capacity of microplastics in the sediment and on the canopy was higher for subtidal than for intertidal vegetated habitats. We conclude that generalizations in the trapping effect of coastal vegetated areas should be done with caution, since it may be highly variable and may depend on the plastic size, habitat and tidal position. Since these habitats support a high biodiversity, they should be included in assessments of plastic debris accumulation and impacts in coastal areas. Further research, including experimental studies, is needed to shed more light on the role of coastal vegetated habitats as plastic sinks.
- How tryptophan levels in plant-based aquafeeds affect fish physiology, metabolism and proteomePublication . Cerqueira, Marco; Schrama, Denise; Silva, Tome S.; Colen, R.; Engrola, Sofia; Conceicao, Luis E. C.; Rodrigues, Pedro; Farinha, Ana PaulaFish meal replacement by plant-protein sources is a priority in aquaculture feeds. Within this framework, dietary supplementation with essential amino acids (EAA), as tryptophan (TRP), is strategic to ensure that the individual nutritional needs are met, besides promoting enhanced immunological status. The purpose of this study was to examine the beneficial effects of TRP incorporation in plant-protein source diets on fish growth performance and nutritional status. We tested diets with 20% lower (LTRP) and 27% higher (HTRP) of the putative requirements of TRP for seabream (Sparus aurata) and assessed its impact on fish physiology and liver metabolism and proteome. After 12 weeks, growth performance, body proximate, hepatic composition and liver metabolic profiling were similar between diets. Nevertheless, liver proteome analysis indicated a higher accumulation of proteins involved in acute-phase responses, typically triggered by infection, inflammation or trauma, in fish fed with HTRP diet as compared with those fed with LTRP. The overall results obtained suggest a potential beneficial effect of TRP supplementation in terms of immune stimulation, without compromising growth or feed intake. Moreover, proteomics and metabolic profiling demonstrate to be valuable tools in this endeavour. Significance: Nutritional needs are hard to assess in aquaculture fisheries, and many times controversial depending on the methodology employed. The estimated amino acid requirements depend on both fish species and stage development, making it extremely hard to standardise. On the other hand, the substitution of fish-based to plant-based protein sources diets towards a sustainable aquaculture, may imbalance these requirements, being necessary further studies to assess the impact on fish growth and development. Finally, the incorporation of crystalized amino acids such as TRP into diets aims global better performance both at fish health/immune condition and growth development. This work focused on the potential beneficial effects of TRP supplementation into diets with a plant-based protein source, addressing the effects on the liver metabolism and proteome, and on growth performance of Gilthead seabream juveniles, a species with special relevance and economical importance in the Mediterranean region. The present study by employing proteomics together with metabolic profiling shows that TRP supplementation at the tested doses, does not compromise growth performance, and seems to stimulate the immune system. Our findings can contribute to the development of new feed formulations for Gilthead seabream species, therefore, reinforcing the resilience and competitiveness of the on-growing aquaculture industry and impact directly the sustainability of living resources with the decrease of the fisheries needs to fulfil the human search for quality proteins consume.
- Dissolved oxygen dynamics in Ria Formosa Lagoon (South Portugal) - A real time monitoring station observatoryPublication . Cravo, Alexandra; Rosa, Alexandra; Jacob, J.; Correia, CátiaDissolved oxygen (DO) is considered one of the most important environmental variables of water quality. This work aimed to provide, for the first time, insights regarding DO dynamics on a representative site of the productive Ria Formosa coastal lagoon, south Europe, using a real time monitoring station observatory (acquiring data every 15 min) deployed for a period of two and a half years. This comprehensive data set represents an added value contributing to a better understanding of the DO variability throughout analyzing semidiurnal, daily, fortnightly tidal cycles (spring tide vs. neap tide), seasonal and interannual periods. This observational station was able to capture distinct temporal signatures, including episodic upwelling and meteorological events advancing the knowledge about the functioning of Ria Formosa. DO was highly variable presenting an evident seasonal distribution with the maximum concentration in spring and the minimum in summer night periods. Critical values < 5 mg/L were recorded only in 3% of the global data set with negligible hypoxia events, showing infrequent DO stressful conditions in the study area. In addition, the disclosure of its did dynamics over long periods, provided by this data set, allows to determine the impact of biological activity upon the DO variability and related ecosystem metabolism behavior (autotrophic vs. heterotrophic), through the metric estimation of Net Ecosystem Metabolism (NEM). NEM in the study area revealed to be slightly heterotrophic along one year of observation, reflecting the median percentage of DO saturation (93%). The acquired data set is highly valuable and can contribute to Ria Formosa management and protection, which is imperative for building knowledge-based societies.
- Boas práticas de TIC em alinhamento com o Green ITPublication . Landum, Manuel; Moura, Maria Margarida da Cruz Silva Andrade Madeira e Carvalho de; Reis, LeonildeAs Tecnologias de Informação e Comunicação estão de tal forma enraizadas no nosso dia a dia que sem elas seria difícil manter a sociedade em funcionamento. Um desses exemplos é a Administração Pública, onde os processos circulam eletronicamente entre a administração central, regional ou local, permitindo uma maior celeridade, tendo em conta a facilidade de envio e receção da documentação. Esta realidade, conjugada com a pressão exercida pelos munícipes ou cidadãos em geral sobre a administração, conduz à necessidade de modernização e expansão dos serviços, tornando-os ubíquos, permitindo uma maior mobilidade, mais céleres, reduzindo os tempos de resposta, e uma consolidação das infraestruturas tecnológicas. Assim sendo, estas práticas devem assentar em pilares como a sustentabilidade, reforço da segurança da informação e melhoria da qualidade ambiental. O objetivo do artigo centra-se na apresentação de boas práticas das TIC alinhadas com o Green IT, suportadas em standards internacionais e frameworks, para otimização de práticas nas organizações, nomeadamente na Administração Local. Os principais resultados da abordagem vão no sentido de contribuir de forma ativa para a implementação de políticas de sustentabilidade e o alinhamento com as boas práticas do Green IT, na Administração Local.
- Phytoplankton response to nutrient pulses in an upwelling system assessed through a microcosm experiment (Algarrobo Bay, Chile)Publication . Ferreira, A.; Sa, Carolina; Silva, N.; Beltran, C.; Dias, A. M.; Brito, A. C.Nutrient enrichment in coastal areas can lead to severe disturbances in marine ecosystems with implications on ecosystem functioning. The primary goal of this study was to understand the response of phytoplankton, from a region with intense upwelling events, to pulsed nutrient enrichments. A microcosm experiment using natural assemblages was conducted, following the addition of inorganic nitrogen (N) and phosphorus (P) and considering two different nutrient limitation conditions (N:P<16 and N:P>16). Laboratory work included the analysis of nutrients, as well as phytoplankton cell abundances. A fast response to the pulsed nutrient enrichments were observed in both treatments as biomass increased. Although higher biomass values were found under higher N concentrations, the community's composition was similar in both treatments. Centric diatoms, particularly Chaetoceros spp., strengthened their dominance, suggesting that, under these conditions, these may have physiological advantages that promote their growth over other groups. Throughout the experiment, phytoflagellates and pennate diatoms were common, while dinoflagellates were scarce. This study contributes to understanding how phytoplankton communities' growth and composition relate to nutrient pulses. These results provide relevant data for environmental quality assessment and management of marine environments.
- A single drop histamine sensor based on AuNPs/MnO2 modified screen-printed electrodePublication . Knezevic, Sara; Ognjanovic, Milos; Nedic, Nemanja; Mariano, José; Milanovic, Zorana; Petkovic, Branka; Antic, Bratislav; Djuric, Sanja Vranjes; Stankovic, DaliborIn order to ensure high food quality, one of the prime importance is the detection and quantification of histamine, well known marine food poison. In this work, we constructed novel electrochemical biosensor for the detection of histamine based on gold nanoparticles decorated on manganese dioxide (Au/MnO2) and used for modification of screen-printed carbon electrode (Au/MnO2@SPCE). The constructed sensor was then used for the estimation of histamine content in a single drop. Materials used in this study were synthesized and characterized using HR-TEM, XRPD and electrochemical methods. The amperometric detection method was optimized and, under selected operating parameters (supporting electrolyte pH 6, working potential of 1 V), the proposed sensor possesses linear working range from 0.3 mu M to 5.1 mu M, with a detection limit of 0.08 mu M. The effect of selected interferences was investigated and it was found that the developed approach offers accurate, precise, selective, fast and reproducible quantification of histamine using only one drop of the sample. In the end, this work stands as a proof-of-concept of the modified electrodes and electrochemical detection as a promising and prospective approach for the applications in real-time monitoring of the food quality.
- Casting a new light on the seismic risk assessment of stone masonry buildings located within historic centresPublication . Maio, Rui; Estêvão, João M. C.; Ferreira, Tiago Miguel; Vicente, RomeuIn light of the new legal framework in force in Portugal, which defines the terms for reporting the seismic vulnerability assessment and the need for seismic strengthening of existing buildings, this paper aims at investigating the correlation between two well-known approaches for the seismic risk assessment of stone masonry buildings located within historic centres: the vulnerability index method and nonlinear static seismic analyses. The latter were carried out by using a new three-dimensional macroelement model to numerically represent the considered sample of prototype buildings, together with the application of the N2 Method. In this paper, the original purpose of the vulnerability index method, that of ranking the seismic vulnerability of existing urban cultural heritage (UCH) assets within the same building typology, was numerically validated. However, when reverting the use of the vulnerability index method by replacing the Macroseismic Intensity with a response spectrum, the results were not as interesting as envisaged, since the correlations between the vulnerability index and the main properties of the capacity curves derived from numerical models, presented, in general, a poor fitting. Finally, the possible causes for such poor fitting and future lines of investigation are discussed. Despite these results must be understood with due care and diligence, the authors believe that this exercise might encourage new investigations on this topic that could lead to the development of a new code-oriented methodology for the seismic risk assessment of UCH assets within historic centres.
- Cells isolated from regenerating caudal fin of Sparus aurata can differentiate into distinct bone cell lineagesPublication . Vijayakumar, Parameswaran; Cardeira, João; Laizé, Vincent; J. Gavaia, Paulo; Cancela, M. LeonorTeleosts have the ability to regenerate their caudal fin upon amputation. A highly proliferative mass of undifferentiated cells called blastema forms beneath wound epidermis and differentiates to regenerate all missing parts of the fin. To date, the origin and fate of the blastema is not completely understood. However, current hypotheses suggest that the blastema is comprised of lineage-restricted dedifferentiated cells. To investigate the differentiation capacity of regenerating fin-derived cells, primary cultures were initiated from the explants of 2-days post-amputation (dpa) regenerates of juvenile gilthead seabream (Sparus aurata). These cells were subcultured for over 30 passages and were named as BSa2. After 10 passages they were characterized for their ability to differentiate towards different bone cell lineages and mineralize their extracellular matrix, through immunocytochemistry, histology, and RT-PCR. Exogenous DNA was efficiently delivered into these cells by nucleofection. Assessment of lineage-specific markers revealed that BSa2 cells were capable of osteo/chondroblastic differentiation. BSa2 cells were also found to be capable of osteoclastic differentiation, as demonstrated through TRAP-specific staining and pit resorption assay. Here, we describe the development of the first successful cell line viz., BSa2, from S. aurata 2-dpa regenerating caudal fins, which has the ability of multilineage differentiation and is capable of in vitro mineralization. The availability of such in vitro cell systems has the potential to stimulate research on the mechanisms of cell differentiation during fin regeneration and provide new insights into the mechanisms of bone formation.
- Methylation patterns in dysplasia in inflammatory bowel disease patientsPublication . Rosa, Isadora; Silva, Patricia; da Mata, Sara; Magro, Fernando; Carneiro, Fatima; Peixoto, Armando; Silva, Marco; Sousa, Helena Tavares; Roseira, Joana; Parra, Jose; Barosa, Rita; Vieira, Ana; Brito, Maria Jos; Lago, Paula; Coelho, Andre; Moleiro, Joana; da Silva, Joao Pereira; Fonseca, Ricardo; Albuquerque, Cristina; Dias Pereira, A.Background and aims:Inflammatory Bowel Disease (IBD) with colonic involvement increases colorectal cancer risk. However, the distinction between IBD related and sporadic dysplasia in IBD patients is difficult. Some data favors the importance of abnormal DNA methylation in IBD-related carcinogenesis. We aimed to define methylation patterns in patients with colonic cancer or dysplasia diagnosis following an IBD diagnosis. Methods:Multicentric cross-sectional study-91 samples from colonic mucosa with/without dysplasia from 9 patients with IBD-related dysplasia/cancer and 26 patients with IBD and sporadic dysplasia/cancer were included. Methylation patterns of CpG islands in the promoter regions of 67 genes were studied by Methylation-specific Multiplex Ligation-dependent Probe Amplification. Results:Mean age at IBD diagnosis: 42 +/- 16 years;at dysplasia diagnosis: 56 +/- 14 years. Twenty-ninepatients had ulcerative colitis. Twenty-five patients had at least 1 lesion endoscopically described as adenoma-like, 4 at least 1 non-adenoma like, 3 had cancer and 3 had dysplasia in flat mucosa. No patient had both adenoma-like and non-adenoma-like lesions. Patients with an IBD-related lesion were significantly younger at IBD diagnosis (p = .003) and at dysplasia/cancer diagnosis (p = .039). Promoter methylation ofIGF2, RARB, ESR1, CHFR, CDH13, WT1, GATA5, WIF1genes was significantly associated to dysplasia/cancer; methylation ofMSH6, TIMP3was significantly associated to IBD-related dysplasia/cancer. Promoter methylation ofMSH6, MSH3, RUNX3, CRABP1, TP73, RARB, CDH13, PAX5, WT1, THBS1, TP53, SFRP1, WIF1, APAF1,BCL2genes was significantly associated to active IBD. Conclusions:Methylation analysis, namely ofMSH6, may contribute to the classification of dysplastic lesions in IBD- to be further tested in prospective studies.