28 research outputs found

    Factors controlling recent diatom assemblages across a steep local nutrient gradient in central-eastern Finland

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    The Iisalmi Route, a chain of lakes in central-eastern Finland, is more eutrophic than its surroundings. We used multivariate analyses to study the influence of selected environmental factors (water quality, basin characteristics, and subcatchment surficial geology) on the recent diatom assemblages across this steep local nutrient gradient. In addition to the spatial analysis of surface sediment diatom assemblages from 51 sampling sites (48 lakes), temporal changes in the total phosphorus (TP) concentrations of one Iisalmi Route lake (Lake Kirmanjärvi) were analyzed using weighted averaging partial least squares regression and 27 fossil diatom samples. Both TP and electrical conductivity (EC) showed statistically significant independent signals in the modern diatom data. The TP gradient was related to till grain size variation suggesting that geological factors affect the spatial TP variation directly or indirectly through differences in land use. Based on the temporal study, the direct effect of geology is most likely behind the steep nutrient gradient in the area because Lake Kirmanjärvi was found to be naturally eutrophic. EC, on the other hand, seems related to anthropogenic disturbance. Our study highlights the importance of taking the local geology into account when assessing past or present water quality or planning for lake management.</p

    Wall‐modeled large‐eddy simulation in a finite element framework

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    This work studies the implementation of wall modeling for large‐eddy simulation in a finite element context. It provides a detailed description of how the approach used by the finite volume and finite differences communities is adapted to the finite element context. The new implementation is as simple and easy to implement as the classical finite element one, but it provides vastly superior results. In the typical approach used in finite elements, the mesh does not extend all the way to the wall, and the wall stress is evaluated at the first grid point, based on the velocity at the same point. Instead, we adopt the approach commonly used in finite differences, where the mesh covers the whole domain and the wall stress is obtained at the wall grid point, with the velocity evaluated at the first grid point off the wall. The method is tested in a turbulent channel flow at R e τ =2003, a neutral atmospheric boundary layer flow, and a flow over a wall‐mounted hump, with significant improvement in the results compared to the standard finite element approach. Additionally, we examine the effect of evaluating the input velocity further away from the walThis work was supported by the Energy oriented Centre of Excellence II (EoCoE‐II), grant agreement number 824158, funded within the Horizon2020 framework of the European Union. We would also like to acknowledge PRACE for awarding us access to the following resources: GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (www.lrz.de), Marconi at CINECA (http://www.hpc.cineca.it/), and TGCC Curie at CEA‐GENCI (http://www‐hpc.cea.fr). The authors thankfully acknowledges the computer resources at MareNostrum and the technical support provided by Barcelona Supercomputing Center (RES‐AECT‐2018‐3‐0028).Peer ReviewedPostprint (author's final draft

    The Ultraviolet radiation (UV-C) for the microbiological stabilization of red wine

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    O procedimento tradicional de controlo da estabilidade microbiológica no vinho consiste na adição de dióxido de enxofre (SO2), que atua como agente antimicrobiano e também antioxidante. A procura de métodos alternativos de controlo microbiológico é importante e necessária, dado que o dióxido de enxofre é um potencial alérgeno e os consumidores procuram cada vez mais produtos saudáveis e livres de conservantes. A radiação ultravioleta tem sido estudada como uma tecnologia inovadora que pode auxiliar na redução do teor de dioxido de enxofre em enologia. O objectivo deste trabalho foi optimizar as condições do processo, face aos resultados já obtidos anteriormente, e avaliar a eficiência na estabilização microbiologica, e a sua influência nos parâmetros fisico-quimicos, na composição fenólica, e nas caracteristicas sensoriais. Assim, o vinho tinto com teor muito baixo em SO2 foi submetido a radiação UV-C com duas doses diferentes, 424J/L e 778J/L, e procedeu-se ainda à preparação de um controlo, a que foi adicionado 30 mg/L de dióxido de enxofre. Os vinhos (UV0, UV1 e UV2) foram analisados ao longo do tempo (de 0 a 4 meses). Os resultados mostram que o tratamento com menor dose é eficaz no controlo microbiológico do produto. A análise sensorial mostrou que o tratamento com radiação UV-C não afectou o aroma e o sabor dos vinhos, inclusivamente estes vinhos foram mais pontuados no descritor intensidade da cor.The traditional procedure for the control of the microbiological stability of wine consists of the addition of sulfur dioxide (SO2), which acts as an antimicrobial agent and also as an antioxidant. The search for alternative methods of microbiological control is important and necessary, since SO2 is a potential allergen and consumers are increasingly looking for healthier and preservative free products. Ultraviolet radiation was tested as an innovative technology that can help reduce the amount of sulphur dioxide used in winemaking. The object of this study was to optimize the process conditions compared to the results obtained previously, and to evaluate the efficiency of microbiological stabilization and its influence on the physico-chemical characteristics, the phenolic composition and sensory profile. Thus, red wine with very low content of sulphur dioxide was subjected to UV-C radiation in two different doses 424J/l e 778J/l, and the preparation of a control wine was carried out to which 30 mg/l sulfur dioxide was added. The wines (control=UV0, UV1 and UV2) were analyzed over time (from 0 to 4 months). The results show that treatment with a lower dosage is effective in the microbiological control of the product. The wines subjected to treatment with UV-C showed an increase in intensity of colour, and the treatment does not affect the flavour and taste of the wine.info:eu-repo/semantics/publishedVersio

    Soil-app: a tool for soil analysis interpretation

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    New apps have changed the traditional way of learning and teaching; they are also applied as a quickly executed and effective method in agriculture. Soil-app is a web application with a friendly click-point interface built through packages lodged in R software. The app is an advanced model of an open-source platform to support teaching and learning activities in soil analyses and fertilizer recommendations. Soil-app includes soil test interpretation, soil amendment calculations (lime and gypsum), the fertilizer rate for the most important crops in Brazil, an NPK blend calculator, and NPK blend evaluation. It also includes experimental statistical analysis as applied to soil science. Soil-app is a user-friendly and high-performance tool, garnering fast adoption by both students and professionals. It is available for network use through the following link: http://www.genetica.esalq.usp.br/alogamas/R.htm

    Design Constraints on a Synthetic Metabolism

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    A metabolism is a complex network of chemical reactions that converts sources of energy and chemical elements into biomass and other molecules. To design a metabolism from scratch and to implement it in a synthetic genome is almost within technological reach. Ideally, a synthetic metabolism should be able to synthesize a desired spectrum of molecules at a high rate, from multiple different nutrients, while using few chemical reactions, and producing little or no waste. Not all of these properties are achievable simultaneously. We here use a recently developed technique to create random metabolic networks with pre-specified properties to quantify trade-offs between these and other properties. We find that for every additional molecule to be synthesized a network needs on average three additional reactions. For every additional carbon source to be utilized, it needs on average two additional reactions. Networks able to synthesize 20 biomass molecules from each of 20 alternative sole carbon sources need to have at least 260 reactions. This number increases to 518 reactions for networks that can synthesize more than 60 molecules from each of 80 carbon sources. The maximally achievable rate of biosynthesis decreases by approximately 5 percent for every additional molecule to be synthesized. Biochemically related molecules can be synthesized at higher rates, because their synthesis produces less waste. Overall, the variables we study can explain 87 percent of variation in network size and 84 percent of the variation in synthesis rate. The constraints we identify prescribe broad boundary conditions that can help to guide synthetic metabolism design

    Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

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    Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

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    The enormous quantity of food wastes discarded annually force to look for alternatives for this interesting feedstock. Thus, food bio-waste valorisation is one of the imperatives of the nowadays society. This review is the most comprehensive overview of currently existing technologies and processes in this field. It tackles classical and innovative physical, physico-chemical and chemical methods of food waste pre-treatment and extraction for recovery of added value compounds and detection by modern technologies and are an outcome of the COST Action EUBIS, TD1203 Food Waste Valorisation for Sustainable Chemicals, Materials and Fuels

    Real-world outcomes of anti-VEGF treatment for retinal vein occlusion in Portugal

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    PURPOSE: Retinal vein occlusion (RVO) is an important cause of visual disability in the modern world. We aim to evaluate the real-world outcomes of patients with RVO treated with anti-vascular endothelial growth factor (VEGF) in Portugal. METHODS: We performed a retrospective, observational, multicenter study including 8 centers across Portugal and 200 patients treated with either ranibizumab or bevacizumab. Data were collected at 3 time points: time of diagnosis (0 time point) and 6 and 12 months after initiating treatment. Demographic and clinical data were collected. RESULTS: Median visual acuity (VA) and central macular thickness (CMT) improved in the branch RVO (BRVO), central RVO (CRVO), bevacizumab, and ranibizumab groups at 6 and 12 months compared to baseline, with CMT improving further only in the CRVO and ranibizumab groups between 6 and 12 months (p = 0.002 and p = 0.001, respectively). The CMT was lower in the ranibizumab group compared to the bevacizumab group both at 6 and 12 months (p<0.02). Median CMT improved in both the good and poor baseline VA groups at 6 and 12 months compared to baseline (p<0.001). Median VA only improved for the group with poor baseline VA at 6 and 12 months of follow-up (p<0.001). Regression analysis identified several baseline variables as predictors of visual outcomes at 6 and 12 months, with different results depending on the analyzed group. CONCLUSIONS: Both treatments were effective, although less effective than results reported in clinical trials. The morphologic response was better with ranibizumab compared to bevacizumab, although functionally there were no differences.info:eu-repo/semantics/publishedVersio
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