2,046 research outputs found

    Assessment of the allelochemical activity and biochemical profile of different phenotypes of picocyanobacteria from the genus synechococcus

    Get PDF
    Organisms belonging to Synechococcus sp. genera are observed in all freshwater, brackish, and marine waters of the world. They play a relevant role in these ecosystems, since they are one of the main primary producers, especially in open ocean. Eventually, they form mass blooms in coastal areas, which are potentially dangerous for the functioning of marine ecosystems. Allelopathy could be an important factor promoting the proliferation of these organisms. According to the authors’ best knowledge, there is no information on the allelopathic activity and allelopathic compounds exhibited by different Synechococcus sp. phenotypes. Therefore, the research conducted here aimed to study the bioactivity of compounds produced by three phenotypes of Synechococcus sp. by studying their influence on the growth, chlorophyll fluorescence, and photosynthetic pigments of eighteen cyanobacteria and microalgae species. We demonstrated that three different Synechococcus sp. phenotypes, including a phycocyanin (PC)-rich strain (Type 1; green strain) and phycoerythrin (PE)-rich strains containing phycoerythrobilin (PEB) and phycocyanobilin (PCB) (Type 2; red strain and Type 3a; brown strain), had a significant allelopathic effect on the selected species of cyanobacteria, diatoms, and green algae. For all green algae, a decrease in cell abundance under the influence of phenotypes of donor cyanobacteria was shown, whereas, among some target cyanobacteria and diatom species, the cell-free filtrate was observed to have a stimulatory effect. Our estimates of the stress on photosystem II (Fv/Fm) showed a similar pattern, although for some diatoms, there was an effect of stress on photosynthesis, while a stimulatory effect on growth was also displayed. The pigment content was affected by allelopathy in most cases, particularly for chlorophyll a, whilst it was a bit less significant for carotenoids. Our results showed that Synechococcus sp. Type 3a had the strongest effect on target species, while Synechococcus sp. Type 1 had the weakest allelopathic effect. Furthermore, GC-MS analysis produced different biochemical profiles for the Synechococcus strains. For every phenotype, the most abundant compound was different, with oxime-, methoxy-phenyl- being the most abundant substance for Synechococcus Type 1, eicosane for Synechococcus Type 2, and silanediol for Synechococcus Type 3aThis research was founded by BMN grant number 539-O140-B416-20, FCT Projects UIDB/04423/2020and UIDP/04423/2020

    Potential control of toxic cyanobacteria blooms with Moroccan seaweed extracts

    Get PDF
    Marine macroalgae are a promising source of diverse bioactive compounds with applications in the biocontrol of harmful cyanobacteria blooms (cyanoHABs). In this work, we evaluated the potential algicidal activities of 14 species of seaweed collected from the coast of Souiria Laqdima, Morocco. Methanol extracts were screened in solid and liquid medium against the growth of the toxic cyanobacteria Microcystis aeruginosa and the microalgae Chlorella sp. used as food supplement. The results in solid medium revealed that the algicidal activity was limited to M. aeruginosa with the extract of Bornetia secundiflora showing the highest growth inhibition activity against Microcystis (27.33 ± 0.33 mm), whereas the extracts of Laminaria digitata, Halopytis incurvus, Ulva lactuca, and Sargasum muticum showed no inhibition. In liquid medium, the results indicated that all methanolic extracts of different macroalgae tested have a significant inhibitory effect on M. aeruginosa compared with that of the negative control. The maximum inhibition rates of M. aeruginosa were produced by the extracts of Bifurcaria tuberculata, Codium elongatum, and B. secundiflora. Moreover, the extracts of B. secundiflora recorded the maximum inhibition rate of Chlorella sp. Overall, the results highlight the potential of the extracts from macroalgae to control toxic cyanobacteria species.We acknowledge the projects TOXICROP (823860) funded by the H2020 program MSCA-RISE-2018 and the project VALORMAR (24517) of the 10/SI/2016-I&DT Empresarial- Programas Mobilizadores funded by the European Regional Development Fund (ERDF) and by the European Social Fund (ESF)

    Omni-{DETR}: {O}mni-Supervised Object Detection with Transformers

    Get PDF

    Reducing Prediction volatility in the surgical workflow recognition of endoscopic pituitary surgery

    Get PDF
    PURPOSE: Workflow recognition can aid surgeons before an operation when used as a training tool, during an operation by increasing operating room efficiency, and after an operation in the completion of operation notes. Although several methods have been applied to this task, they have been tested on few surgical datasets. Therefore, their generalisability is not well tested, particularly for surgical approaches utilising smaller working spaces which are susceptible to occlusion and necessitate frequent withdrawal of the endoscope. This leads to rapidly changing predictions, which reduces the clinical confidence of the methods, and hence limits their suitability for clinical translation. METHODS: Firstly, the optimal neural network is found using established methods, using endoscopic pituitary surgery as an exemplar. Then, prediction volatility is formally defined as a new evaluation metric as a proxy for uncertainty, and two temporal smoothing functions are created. The first (modal, Mn) mode-averages over the previous n predictions, and the second (threshold, Tn) ensures a class is only changed after being continuously predicted for n predictions. Both functions are independently applied to the predictions of the optimal network. RESULTS: The methods are evaluated on a 50-video dataset using fivefold cross-validation, and the optimised evaluation metric is weighted-F1 score. The optimal model is ResNet-50+LSTM achieving 0.84 in 3-phase classification and 0.74 in 7-step classification. Applying threshold smoothing further improves these results, achieving 0.86 in 3-phase classification, and 0.75 in 7-step classification, while also drastically reducing the prediction volatility. CONCLUSION: The results confirm the established methods generalise to endoscopic pituitary surgery, and show simple temporal smoothing not only reduces prediction volatility, but actively improves performance

    Collaborative process design for waste management: co-constructing strategies with stakeholders

    Get PDF
    Funding Information: Thanks are due to all UrbanWINS project partners. Also, the authors acknowledge FCT - Foundation for Science and Technology (Portugal) through the strategic project UIDB/04292/2020 granted to MARE - Marine and Environmental Sciences Centre. And to NOVA School of Science and Technology - NOVA University Lisbon, to several other team members Ana Gomes, Pedro Santos and Mario Ramos Waste@nova team members that collaborate in several activities of the project, as well as to Prof. Joaquim Pina and Prof. Ana Silveira. The UrbanWINS project presented in this paper was funded by the European Union's Horizon 2020 research and innovation program under grant agreement no.690047.Waste management is currently facing multiple challenges worldwide. The population growth in urban areas and related environmental concerns have increased the need to promote urban sustainability, namely where urban waste is a challenge. Thus, research on efficient waste management to reduce resources overload and to develop more sustainable production and consumption is key. Having this in mind, modern society is now seeking for an active voice and to be part of the decision-making processes that directly affect citizens. Citizens need to play an active role on decision-making to co-construct action guidelines, aiming a higher implementation success for an effective and inclusive management of urban waste. In this sense, UrbanWINS project was developed to promote co-construction and implementation of pilot actions involving citizens. In this paper the authors described the framework developed, and reflect critically on the results achieved.publishersversionepub_ahead_of_prin

    Avaliação da cultura de segurança do paciente na Amazônia Ocidental

    Get PDF
    Introdução: A cultura de segurança do paciente é fator contribuinte para a manutenção do bem-estar do usuário no sistema de saúde, pois por meio dela obtém-se uma sistematização organizada e de qualidade do cuidado ao paciente, prevenindo possíveis intercorrências que possam trazer danos. Objetivo: Analisar a Cultura de Segurança do Paciente (CSP) na perspectiva dos profissionais de saúde no Hospital de Referência do Alto Rio Juruá, na Amazônia Ocidental Brasileira. Método: Trata-se de um estudo transversal desenvolvido em um hospital público de médio porte em um município da Amazônia Ocidental. O questionário Hospital Survey on Patient Safety Culture, da Agency for Healthcare Research and Quality foi aplicado em 280 profissionais, no período dezembro de 2016 a fevereiro de 2017. Foi realizada a análise descritiva dos dados e a consistência interna do instrumento. Resultados: Os resultados apontam as melhores avaliações nas dimensões de Trabalho em equipe nos âmbitos das unidades (60%) e Aprendizado organizacional (60%). Os aspectos com os piores resultados foram as dimensões de Respostas não punitivas aos erros (18%) e Frequência de eventos relatados (32%). A análise de confiabilidade interna (Alpha de Cronbach) das dimensões variou entre 0,35 a 0,90. Conclusão: A cultura do medo parece predominar nesse hospital, contudo o estudo demonstrou que há possibilidades de melhoria em todas as dimensões da CSP. Os valores do Alpha de Cronbach apresentaram semelhança com os resultados obtidos pelo processo de validação.Introduction: The safety culture of the patient is a contributing factor for the maintenance of the user’s well-being in the health system because, through it, an organized systematization and quality of patient care are obtained, preventing possible intercurrences that can cause damages. Objective: To analyze the Patient Safety Culture (PSC) from the perspective of health professionals at the Reference Hospital of the Upper Juruá River, in the Brazilian Western Amazon. Methods: This is a cross-sectional study developed in a medium-sized public hospital in a municipality in Western Amazonia. The Survey for Patient Safety Culture survey of the Agency for Healthcare Research and Quality was applied to 280 professionals from December 2016 to February 2017. Descriptive analysis of the data and the internal consistency of the instrument were performed. Results: The results indicate the best evaluations in the dimensions of Teamwork in the scopes of the units (60%) and Organizational learning (60%). The aspects with the worst results were the dimensions of non-punitive responses to errors (18%) and frequency of events reported (32%). The internal reliability (Cronbach’s Alpha) analysis of the dimensions ranged from 0.35 to 0.90. Conclusion: The "culture of fear" seems to predominate in this hospital, however, the study showed that there is scope for improvement in all dimensions of CSP. The values of Cronbach’s Alpha presented similarity to the results obtained by the validation process
    • …
    corecore