Data-analyse algen en waterplanten in relatie tot nutriënten in brakke wateren

Het project “data-analyse algen en waterplanten in relatie tot nutriënten in brakke wateren” was een pilot studie die gericht was op Sleutelfactor 1, Productiviteit (STOWA, 2014). De hoofdvraag die hierbij voorlag was om een analyse uit te voeren van nutriënten in relatie tot algengroei en het voorkomen van ondergedoken waterplanten in brakke watersystemen (range 1000 – 5000 mg/L Cl). Om deze vraag te beantwoorden zijn significante relaties onderzocht tussen nutriëntengehalten (verschillende vormen van fosfaat en stikstof) in het oppervlaktewater, de abundantie van algen (fytoplankton als Chlorofyl-a) en het voorkomen en de abundantie van ondergedoken waterplanten in brakke wateren

Applying electrohydrodynamic atomization to enhance mass transfer of metal salts from an aqueous phase towards ionic liquids

In this work a two coaxial nozzles configuration is used to investigate whether electro hydrodynamic atomization of an ionic liquid in combination with an aqueous metal salt solution could enhance the removal of metal salts. The technique was evaluated for the removal of manganese (II), cobalt (II) calcium and sodium chloride. Good metal salt extraction was observed for the water-presaturated ionic liquid, tetraoctylammonium oleate, at an applied electrical potential of 5 kV, which was slightly lower compared to mechanical mixing, but a higher separation factor was obtained between the transition metals and the alkali and earth alkali metal

The chronic toxicity of emamectin benzoate to three marine benthic species using microcosms

The commercial farming of Atlantic salmon, Salmo salar, may require the periodic application of emamectin benzoate (EB) treatments to reduce the effects of biological pests, such as sea lice. As a result, EB is detected in sediments beneath these fish farms at considerable levels. Literature sediment toxicity data for EB for marine benthic species is only available for 10-day sediment toxicity tests, which might be too short to assess field effects. Here, we present a sediment toxicity test to determine 28-day mortality and growth effect concentrations for the non-target polychaete worm Arenicola marina, the crustacean Corophium volutator and the mollusk Cerastoderma edule using a marine microcosm setup. Results indicate that no concentration-dependent increase of mortality and growth rate was apparent to A. marina and C. edule. But for C. volutator, a concentration-dependent increase in mortality was observed, resulting in a calculated 28-d LC50 of 316 μg/kg dry sediment (95% confidence interval: 267–373 μg/kg dry sediment). There were significant effects on C. volutator growth rate at concentrations of 100 μg/kg dry sediment and above (NOEC = 30 μg/kg dry sediment). These observations show that C. volutator is more sensitive to EB than A. marina, which differs from results reported in previous studies. Comparison to the most sensitive NOEC (30 μg/kg dry sediment) found for C. volutator (organisms of 8–11 mm length), shows that the Environmental Quality Standard, derived by the Scottish Environment Protection Agency in 2017 which based on freshwater species data (NOEC = 1.175 μg/kg dry sediment), are relatively strict and is sufficiently protective for the marine species tested in this paper.</p

Dataset underlying the publication Seasonal dynamics of the macrophyte test species Myriophyllum spicatum over two years in experimental ditches for population modelling application in risk assessment

The dataset covers biotic and abiotic data from the aquatic habitat of a population of the sediment-rooted macrophyte Myriophyllum spicatum in the temperate climate region (The Netherlands). The growth of M. spicatum was monitored in 0.2025 m2 plant baskets installed in an experimental ditch. Parameters monitored included biomass (fresh and dry weight), shoot length, seasonal short-term growth rates of shoots, relevant environmental parameters and weather data. This dataset includes the 2-year experimental biotic (macrophyte biomass and growth data) and environmental data (water quality data, sediment data). A second file includes the statistical data. A third file includes the weather data

Reproducibility of fluorescent expression from engineered biological constructs in E. coli

We present results of the first large-scale interlaboratory study carried out in synthetic biology, as part of the 2014 and 2015 International Genetically Engineered Machine (iGEM) competitions. Participants at 88 institutions around the world measured fluorescence from three engineered constitutive constructs in E. coli. Few participants were able to measure absolute fluorescence, so data was analyzed in terms of ratios. Precision was strongly related to fluorescent strength, ranging from 1.54-fold standard deviation for the ratio between strong promoters to 5.75-fold for the ratio between the strongest and weakest promoter, and while host strain did not affect expression ratios, choice of instrument did. This result shows that high quantitative precision and reproducibility of results is possible, while at the same time indicating areas needing improved laboratory practices.Peer reviewe