586 research outputs found

    Rapid toxicity assessment of six antifouling booster biocides using a microplate-based chlorophyll fluorescence in Undaria pinnatifida gametophytes

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    Biocides of antifouling agents can cause problems in marine ecosystems by damaging to non-target algal species. Aquatic bioassays are important means of assessing the quality of water containing mixtures of contaminants and of providing a safety standard for water management in an ecological context. In this study, a rapid, sensitive and inexpensive test method was developed using free-living male and female gametophytes of the brown macroalga Undaria pinnatifida. A conventional fluorometer was employed to evaluate the acute (48 h) toxic effects of six antifouling biocides: 4,5-Dichloro-2-octyl-isothiazolone (DCOIT), diuron, irgarol, medetomidine, tolylfluanid, zinc pyrithione (ZnPT). The decreasing toxicity in male and female gametophytes as estimated by EC50 (effective concentration at which 50% inhibition occurs) values was: diuron (0.037 and 0.128 mg l(-1), respectively) > irgarol (0.096 and 0.172 mg l(-1), respectively) > tolylfluanid (0.238 and 1.028 mg l(-1), respectively) > DCOIT (1.015 and 0.890 mg l(-1), respectively) > medetomidine (12.032 and 12.763 mg l(-1), respectively). For ZnPT, 50% fluorescence inhibition of U. pinnatifida gametophytes occurred at concentrations above 0.4 mg l(-1). The Undaria method is rapid, simple, practical, and cost-effective for the detection of photosynthesis-inhibiting biocides, thus making a useful tool for testing the toxicity of antifouling agents in marine environments

    K-MHaS: A Multi-label Hate Speech Detection Dataset in Korean Online News Comment

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    Online hate speech detection has become an important issue due to the growth of online content, but resources in languages other than English are extremely limited. We introduce K-MHaS, a new multi-label dataset for hate speech detection that effectively handles Korean language patterns. The dataset consists of 109k utterances from news comments and provides a multi-label classification using 1 to 4 labels, and handles subjectivity and intersectionality. We evaluate strong baseline experiments on K-MHaS using Korean-BERT-based language models with six different metrics. KR-BERT with a sub-character tokenizer outperforms others, recognizing decomposed characters in each hate speech class.Comment: Accepted by COLING 202

    Toxicity testing of cosmetic ingredients using gametophyte beads of the brown alga Undaria pinnatifida (Laminariales, Phaeophyta)

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    File embargoed until 03.01.2020 (publisher’s embargo period).A 6-h toxicity test of cosmetic ingredients (methylparaben, 2-phenoxyethanol, sodium dodecyl sulfate, triethanolamine) was developed, based on the photosynthetic maximum quantum yield (Fv/Fm) of immobilized gametophytes of the brown macroalga Undaria pinnatifida. From calculated EC50 values, the toxicity ranking of the tested ingredients is: SDS (0.0060%) > MP (0.0634%) > 2-PE (0.2418%) > TEA (3.7023%). Compared to the results from conventional endpoints with other ecotoxicity test organisms, measurements of Fv/Fm is a more sensitive indicator of the toxic effects of cosmetic ingredients. The present technique is simple, rapid, practical, accurate, and requires little space to carry out. This novel method will be a useful tool for assessing the toxicity of a wide range of cosmetic ingredients once the respective sensitivities are fully established

    Reappraisal of the toxicity test method using the green alga Ulva pertusa Kjellman (Chlorophyta),

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    This study was aimed to develop an objective way of quantifying the reproductive status of the green macroalga, Ulva pertusa using a vital stain and programmed automated analysis (by Image J program). The EC50 values (with 95% CI), the concentrations of toxicants inducing a reduction of 50% in sporulation after 96 h exposure, from the newly developed method were similar to those obtained by the conventional method: 0.651 (0.598-0.705) mg l(-1) for Cd, 0.144 (0.110-0.162) mg l(-1) for Cu, 0.180 (0.165-0.195) mg l(-1) for atrazine, 0.076 (0.049-0.094) mg l(-1) for diuron and 30.6 (26.5-34.4) ml l(-1) for DMSO, respectively. When the EC50 values from this study were compared to that those from literatures, the sensitivity for some toxicants was similar or higher than that of U. fasciata (1.930 mg l(-1) for germination for Cd), U. armoricana (0.250 mg l(-1) for Fv/Fm for Cu), U. reticulata (0.126-1.585 mg l(-1) for growth for Cu), and U. intestinalis (0.650 mg l(-1) for Fv/Fm for atrazine). The subjective views of the experimental performers can be eliminated using the newly developed method. The Ulva method gave consistent responses to Cu and Cd of internationally allowable ranges for effluents, implying that the method is a useful tool for monitoring industrial wastewaters containing these metals

    Thallus differentiation of photosynthesis, growth, reproduction, and UV-B sensitivity in the green alga Ulva pertusa (Chlorophyceae)

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    The chlorophyte Ulva is perceived as a simple and uniform algal form, with little functional differentiation within a thallus. We compared morphology, pigmentation, photosynthesis, growth, reproduction, and UV-B sensitivity between different thallus regions of Ulva pertusa Kjellman. Thallus thickness and cell size were significantly greater, whereas cell number was less in the basal region than in other regions. Photosynthetic pigment contents were lowest in the basal region and increased toward the marginal region. Photosynthetic capacity and photosynthetic efficiency normalized to fresh weight, area, volume, and cell number showed a progressive increase from the basal to marginal parts; however, on a ch1 basis those values were equal regardless of thallus part. Values of light saturation point were not statistically different between regions. Growth rates increased from marginal to basal and to middle parts of the thallus, whereas sporulation was highest in marginal (100%) followed by middle (30%) and basal parts (0%). Daily observation over 9 days showed that 56% of the basal cells divided once and did not produce spores, whereas every marginal cell went through its first division and 89% of the primary daughter cells also divided, resulting in 100% sporulation. A 7-day treatment with PAR and PAR + UV-A caused a significant decrease in the effective quantum yield of all thallus regions, followed by a recovery toward the initial values, whereas PAR + UV-A + UV-B irradiation led to greater photoinhibition and less recovery. Marked differences in the UV-B sensitivity were observed, with marginal parts being more sensitive and basal parts most resistant

    A novel marine algal toxicity bioassay based on sporulation inhibition in the green macroalga Ulva pertusa (Chlorophyta)

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    Abstract A 5-day aquatic toxicity test based on sporulation inhibition of the green macroalga Ulva pertusa Kjellman has been developed. Optimal test conditions determined for photon irradiance, salinity and temperature were 60-200 mol photons m . The bioassay indicated also that the sporulation endpoint could be a sensitive indicator of toxicity effects of elutriates of sludge as reflected from the NOEC values equal to or lower than the lowest concentration employed (6.25%). Sporulation was significantly inhibitied in all elutriates with the greatest and least effects observed in elutriates of sludge from industrial waste (EC 50 6.78%) and filtration bed (EC 50 15.0%), respectively. The results of the Spearman rank correlation analysis for EC 50 data versus the concentrations of toxicants in the sludge presented a significant correlation between toxicity and four heavy metals (Cd 2+ , Cu 2+ , Pb 2+ , Zn 2+ ). Introduction of the concept of toxicity unit (TU) showed that these metals were the main cause of toxicity in elutriates of at least four out of nine sludge samples. Members of the order Ulvales show a wide geographic distribution and have similar reproductive characteristics, thus making it possible to apply the present test method to other algae of this taxa, elsewhere. This novel method will be a useful tool for assessing the aquatic toxicity of a wide range of toxicants, once the respective sensitivities are demonstrated

    Purified <i>Pyropia yezoensis</i> Pigment Extract-Based Tandem Dye Synthesis

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    Red phycoerythrin (R-PE) is a highly valuable protein found in an edible seaweed, Pyropia yezoensis. It is used extensively in biotechnological applications due to its strong fluorescence and stability in diverse environments. However, the current methods for extracting and purifying R-PE are costly and unsustainable. The aim of the present study was to enhance the financial viability of the process by improving the extraction and purification of R-PE from dried P. yezoensis and to further enhance R-PE value by incorporating it into a tandem dye for molecular biology applications. A combination of ultrafiltration, ion exchange chromatography, and gel filtration yielded concentrated (1 mg·mL–1) R-PE at 99% purity. Using purified PE and Cyanine5 (Cy5), an organic tandem dye, phycoerythrin-Cy5 (PE-Cy5), was subsequently established. In comparison to a commercially available tandem dye, PE-Cy5 exhibited 202.3% stronger fluorescence, rendering it suitable for imaging and analyzes that require high sensitivity, enhanced signal-to-noise ratio, broad dynamic range, or shorter exposure times to minimize potential damage to samples. The techno-economic analysis confirmed the financial feasibility of the innovative technique for the extraction and purification of R-PE and PE-Cy5 production

    Plasma based Particle Acceleration Data Modeling by Using Alpha Shapes

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    Plasma based particle accelerator hasmainly used in nuclear field only because ofthe large scale of the facility. However, sincelaser-plasma particle accelerator which hassmaller size and spends less cost. Developed,the availability of this accelerator is expendedto various research fields such as industrialand medical. In these, real-time and interactiveapplications, accelerating the compute time isa critical problem. We conduct a simulationdiscussed the method of visualization ofmultivariate data in three dimensional spaceby using colored volume rendering and surfacerendering. We also suggest new method tovisualize plasma data by using alpha shape toachieve a different level of detail for the givenplasma based particle acceleration data. Inthis paper, alpha shapes method is applied forthe shake of multiresolution visualization.Level of detail increases the efficiency ofrendering by decreasing the workload

    SUPER-Rec: SUrrounding Position-Enhanced Representation for Recommendation

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    Collaborative filtering problems are commonly solved based on matrix completion techniques which recover the missing values of user-item interaction matrices. In a matrix, the rating position specifically represents the user given and the item rated. Previous matrix completion techniques tend to neglect the position of each element (user, item and ratings) in the matrix but mainly focus on semantic similarity between users and items to predict the missing value in a matrix. This paper proposes a novel position-enhanced user/item representation training model for recommendation, SUPER-Rec. We first capture the rating position in the matrix using the relative positional rating encoding and store the position-enhanced rating information and its user-item relationship to the fixed dimension of embedding that is not affected by the matrix size. Then, we apply the trained position-enhanced user and item representations to the simplest traditional machine learning models to highlight the pure novelty of our representation learning model. We contribute the first formal introduction and quantitative analysis of position-enhanced item representation in the recommendation domain and produce a principled discussion about our SUPER-Rec to the outperformed performance of typical collaborative filtering recommendation tasks with both explicit and implicit feedback.Comment: There was a testing environment issue so it is required to re-conduct the model evaluatio
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