1,721,059 research outputs found
Application of Ulva biomass for bioremediation of wastewater
No full textThe remarkable growth rate and environmental adaptability of Ulva species have attracted considerable interest for their potential applications in aquaculture and bioremediation. Ulva's capacity to absorb nutrients from various wastewaters, including those originating from the dairy industry, positions it as a promising solution for addressing soluble contaminants. To identify Ulva strains with enhanced tolerance to low salinity to support applications with typical terrestrial wastewater streams, a series of laboratory and pilot scale experiments were performed. These experiments involved the co-cultivation of multiple strains from three distinct Ulva species(Ulva lacinulata, Ulva gigantea and Ulva compressa) under different conditions, encompassing varying salinity levels (17.5 PPT and 35 PPT salinity) and diverse wastewater sources. Waters tested included Final Effluent (FEF) water (treated water ready for release downstream), reverse osmosis reject (RO) water (by-product of reverse osmosis process containing concentrated impurities (high nitrate levels) which of often used for treatment of fats), river water (water from River Deel running parallel to factory), balance water (raw sewage which has undergone pH alteration and fat removal) and filtered balance water (balance water filtered to reduce turbidity). The findings from these experiments revealed that filtered balance water supported superior growth rates compared to unfiltered balance water. The co-cultivation studies highlights the strain-specific nature of Ulva's tolerance to low salinity, with certain strains exhibiting higher growth and survival rates under specific conditions. The investigation unveiled fluctuations in the characteristics of FEF water as growth media over a seven-day period. The presence of precipitate (identified as aragonite, a crystal form of CaCO3) on Ulva biomass cultivated in FEF and ASW (Artificial Seawater) dilution was associated with diminished growth and nutrient uptake, emphasizing the intricate relationship between environmental factors and Ulva's growth dynamics. Additionally, the study demonstrated that while FEF water alone did not sustain Ulva growth, the supplementation of F/2 nutrients to FEF water resulted in enhanced growth rates compared to F/2 + ASW alone, which also facilitated a prolonged selection process, allowing for the coexistence of multiple Ulva species. The final aspect of the project focused on the outdoor cultivation trials of the best performing Ulva species (Ulva lacinulata), coupled with detailed biochemical analyses, to elucidate the impact of growth conditions on biomass quality. The results indicated that a density of 2 g/L was excessive for outdoor Ulva cultivation, leading to self-shading and reduced growth rates. Reducing the density to 1 g/L resulted in improved growth performance, suggesting its suitability for outdoor cultivation under optimal conditions. The addition of river water failed to mitigate the formation of precipitate on Ulva biomass when combined with FEF or RO water. Metabolite analysis revealed variations in ash and ulvan content in Ulva cultivated in RO + FEF + river water. Ulva grown in river water exhibits higher ulvan and lower protein content, consistent with the low nitrate levels in river water. Although river water alone did not support Ulva growth due to its low nitrate content, continuous water flow was identified as a potential factor that could enhance Ulva cultivation in such conditions. To conclude, this project shows that wastewater type, time of collection, salinity and strain of Ulva all play important roles in the use of Ulva for bioremediation. Indicating the potential of Ulva spp. in bioremediation of dairy factory effluent. Moreover, conducting additional trials has potential to develop a reliable treatment protocol, capable of not only remedying polluted waters but also generating valuable compounds for diverse downstream applications.2025-01-2
Impact of environmental factors on the life cycle and physiology of the green seaweed Ulva spp.
No full textSea lettuce Ulva spp., known for its worldwide distribution and remarkable growth rate, remains a largely under-exploited natural resource. Recently, this macroalga has established itself as a valuable biomass in aquaculture, thanks to its diverse applications in the food, feed, pharmaceutical, nutraceutical, biofuel and bioremediation sectors. Ulva's rapid growth and high capacity to assimilate carbon, nitrogen and phosphorus make it an attractive option for use as a biological filter. This project investigated the potential of Ulva for nutrient removal in brackish waters, focusing on the impact of reduced salinity on Ulva's metabolism. It also looked at the more fundamental biology of this genus, focusing on its primary carbon metabolism and the strategies it employs to maintain its rapid growth rate. Using isotopic 13C labelling, it was demonstrated that Ulva has a unique diurnal growth pattern, with a disconnect between the building of structural compounds occurring largely in the daylight, and cell expansion growth occurring at night. Then, extensive screening was conducted to identify Ulva strains that maintain valuable metabolic content and high growth rates under low salinity conditions, alongside with the development of a fast-screening method known as the “common-garden experiment”. This approach enabled the selection of the most suitable strains for the desired conditions in a reduced period of time, in a cost-effective way. Species and even strains varied significantly in their tolerance to low salinity, highlighting the importance of genetic/natural variation. A brief exposure to low salinity enhances the biochemical composition of Ulva, notably increasing carbohydrates in certain foliose species. This variability highlights the need for careful selection of species and strains to optimize Ulva biomass valorization for specific applications. In conclusion, the results presented in this thesis have advanced fundamental scientific knowledge of Ulva biology and provided insights into the use of Ulva spp. for nutrient removal in brackish waters
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Reduced levels of NADH-dependent glutamate dehydrogenase decrease the glutamate content of ripe tomato fruit but have no effect on green fruit or leaves
Get PDFGlutamate (Glu) is a taste enhancer that contributes to the characteristic flavour of foods. In fruit of tomato (Solanum lycopersicum L.), the Glu content increases dramatically during the ripening process, becoming the most abundant free amino acid when the fruit become red. There is also a concomitant increase in NADH-dependent glutamate dehydrogenase (GDH) activity during the ripening transition. This enzyme is located in the mitochondria and catalyses the reversible amination of 2-oxoglutarate to Glu. To investigate the potential effect of GDH on Glu metabolism, the abundance of GDH was altered by artificial microRNA technology. Efficient silencing of all the endogenous SlGDH genes was achieved, leading to a dramatic decrease in total GDH activity. This decrease in GDH activity did not lead to any clear morphological or metabolic phenotype in leaves or green fruit. However, red fruit on the transgenic plants showed markedly reduced levels of Glu and a large increase in aspartate, glucose and fructose content in comparison to wild-type fruit. These results suggest that GDH is involved in the synthesis of Glu in tomato fruit during the ripening processes. This contrasts with the biological role ascribed to GDH in many other tissues and species. Overall, these findings suggest that GDH has a major effect on the control of metabolic composition during tomato fruit ripening, but not at other stages of development.Fil: Ferraro, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: D'angelo, Matilde Elvira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Sulpice, Ronan. Botany and Plant Science; IrlandaFil: Stitt, Mark. Max Planck Institute of Molecular Plant Physiology; AlemaniaFil: Valle, Estela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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