30 research outputs found

    Linking Morphology, Toxicokinetic, and Toxicodynamic Traits of Aquatic Invertebrates to Pyrethroid Sensitivity

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    Pyrethroid insecticides are known to be highly toxic to most aquatic nontarget organisms, but little is known about the mechanisms causing some species to be highly sensitive while others are hardly affected by the pyrethroids. The aim of the present study was to measure the sensitivity (EC50-values) of 10 aquatic invertebrates toward a 24 h pulse of the pyrethroid cypermethrin and subsequently test if the difference in sensitivity could be explained by measured morphological and physiological traits and modeled toxicokinetic (TK) and toxicodynamic (TD) parameters. Large differences were observed for the measured uptake and elimination kinetics, with bioconcentration factors (BCFs) ranging from 53 to 2337 at the end of the exposure. Similarly, large differences were observed for the TDs, and EC50-values after 168 h varied 120-fold. Modeling the whole organism cypermethrin concentrations indicated compartmentation into a sorbed fraction and two internal fractions: a bioavailable and non-bioavailable internal fraction. Strong correlations between surface/volume area and the TK parameters (sorption and uptake rate constants and the resulting BCF) were found, but none of the TK parameters correlated with sensitivity. The only parameter consistently correlating with sensitivity across all species was the killing rate constant of the GUTS-RED-SD model (the reduced general unified threshold models of survival assuming stochastic death), indicating that sensitivity toward cypermethrin is more related to the TD parameters than to TK parameters.</p

    EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I: General aspects (Short Version)

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    This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (short version; the long version is published online)

    Inference of missing data in photovoltaic monitoring datasets

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    This is an Open Access Article. It is published by IET publishing under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Photovoltaic (PV) systems are frequently covered by performance guarantees, which are often based on attaining a certain performance ratio (PR). Climatic and electrical data are collected on site to verify that these guarantees are met or that the systems are working well. However, in-field data acquisition commonly suffers from data loss, sometimes for prolonged periods of time, making this assessment impossible or at the very best introducing significant uncertainties. This study presents a method to mitigate this issue based on back-filling missing data. Typical cases of data loss are considered and a method to infer this is presented and validated. Synthetic performance data is generated based on interpolated environmental data and a trained empirical electrical model. A case study is subsequently used to validate the method. Accuracy of the approach is examined by creating artificial data loss in two closely monitored PV modules. A missing month of energy readings has been replenished, reproducing PR with an average daily and monthly mean bias error of about −1 and −0.02%, respectively, for a crystalline silicon module. The PR is a key property which is required for the warranty verification, and the proposed method yields reliable results in order to achieve this

    Comparação de substratos com diferentes quantidades de carboidratos solĂșveis utilizando a tĂ©cnica in vitro semi-automĂĄtica de produção de gases Comparison among substrates with different soluble carbohydrates concentration using the in vitro semi-automatic gas production technique

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    Estudou-se a diferença entre a produção de gases (PG) e a degradação da matĂ©ria seca (DMS) para substratos com diferentes quantidades de carboidratos solĂșveis avaliados pela tĂ©cnica in vitro de produção de gases. Foram utilizados cinco substratos (cana-de-açĂșcar, silagem de milho, capim-coloniĂŁo, milho em grĂŁo e ração comercial para vacas em lactação) antes e apĂłs a retirada parcial dos carboidratos solĂșveis (lavados). A PG foi maior e a DMS menor para o material lavado. A concentração de carboidratos solĂșveis influenciou os resultados obtidos pela tĂ©cnica de produção de gases.<br>The difference between the gas production (GP) and the dry matter degradation (DMD) of substrates with different amounts of soluble carbohydrates using the in vitro gas production technique was studied. Five substrates (sugarcane, maize silage, Panicum maximum grass, corn grain, 20% CP commercial lactating cow ration and soybean meal) and the same substrates with part of its soluble carbohydrate removed (washed materials) were evaluated. The GP was higher and DMD was lower for washed materials than for the original materials. The carbohydrate concentration affects the results of the gas production technique
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