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Ontwikkeling van een quickscan ecologische kwaliteit voor langzaam stromende wateren in Zuid-Nederland op basis van macrofauna
Get PDFEr is een groeiende behoefte aan methoden die op een eenvoudige en snelle wijze een globale uitspraak kunnen doen over de ecologische toestand van een oppervlaktewater. Op basis van macrofaunamonsters van waterschap Brabantse Delta, de Dommel, Aa en Maas, Limburg en Rivierenland genomen in de periode 2014-2019 is daarom een quickscan ontwikkeld waarmee op basis van een beperkte set relatief gemakkelijk herkenbare indicatortaxa de kwaliteit van een langzaam stromende beek of riviertje (KRW-typen R4, R5 en R6) in drie kwaliteitsklassen kan worden ingeschat. Eerst zijn de indicatoren voor de verschillende toestanden vastgesteld en heeft een selectie en/of aanpassing van het taxonomisch niveau op basis van herkenbaarheid plaatsgevonden. Vervolgens is op basis van deze indicatorlijst de quickscan-ontwikkeling gestart. Hiervoor zijn drie benaderingswijzen getest, gebaseerd op positieve en negatieve indicatoren, indicatiewaarden en specifieke taxonomische groepen (EPT). Het bleek dat een quickscan die werkt met de som van de indicatiewaarden van specifieke taxa, die is uitgedrukt in een score van laag tot hoog, welke gedeeld wordt door het totaal aantal scorende taxa om te kunnen corrigeren voor de taxonrijkdom in het monster de beste resultaten gaf bij een vergelijking met de toestandsbepaling op basis van de KRW maatlatten. Met deze benadering, de quickscan ecologische kwaliteit (QS-EK) voor langzaam stromende wateren in Zuid-Nederland, werd circa driekwart van de monsters in dezelfde kwaliteitsklasse ingedeeld
Pilots naar de vermindering van fijnstofemissie uit pluimveestallen: Granovi warmtewisselaar met absoluutfilter en recirculatie
Get PDFTo mitigate the concentrations of fine particulate matter in livestock farming areas, techniques are needed which reduce emissions from poultry barns. In this pilot study, measurements were carried out on the Granovi heat exchanger with absolute filter and recirculation, installed inside a broiler barn. In deviation from the measurement protocols, the so called “fine dust pilots” included one (instead of two) farm locations. The measurements show that the system reduces the emission of fine particulate matter (PM10) with 22%
Genotypic and phenotypic characterization of Phytophthora infestans in South Korea during 2009–2016 reveals clonal reproduction and absence of EU_13_A2 genotype
No full textIn order to better understand the Phytophthora infestans population structure in South Korea, 172 isolates were collected between 2009 and 2016 from four major potato cultivation areas. Fungicide (metalaxyl and dimethomorph) response, mating type, and microsatellite (SSR) genetic fingerprints were analysed to characterize these isolates. Ten isolates collected in Gyeongnam Province, which specializes in protected winter cultivation in polytunnels, were A2 mating type. All other isolates were A1 mating type. Overall, 42% of the isolates were resistant to metalaxyl, and 43% were sensitive. All isolates were sensitive to dimethomorph. From the SSR fingerprints, 45 distinct genotypes were identified, which could be clustered into four clonal lineages: KR_1_A1, KR_2_A2, SIB-1, and US-11. KR_1_A1 was the predominant P. infestans genotype in South Korea. KR_2_A2 was only found in Gyeongnam Province; all isolates were A2 mating type and resistant to metalaxyl. SIB-1 was dominant until 2013 but its frequency has gradually decreased in more recent years. US-11 was first found in 2014, after which its frequency has increased to become codominant with KR_1_A1. The calculated standardized index of association (IA) suggests that the South Korean P. infestans population is undergoing clonal reproduction. When compared with populations of P. infestans from the Netherlands, it has less genetic diversity and the dominant Netherlands P. infestans genotype, EU_13_A2 (Blue_13), was not found in South Korea. Such monitoring of the pathogen population contributes to a more efficient integrated pest management-based control strategy for potato late blight control in South Korea.</p
How to compare sampling designs for mapping?
Get PDFIf a map is constructed through prediction with a statistical or non-statistical model, the sampling design used for selecting the sample on which the model is fitted plays a key role in the final map accuracy. Several sampling designs are available for selecting these calibration samples. Commonly, sampling designs for mapping are compared in real-world case studies by selecting just one sample for each of the sampling designs under study. In this study, we show that sampling designs for mapping are better compared on the basis of the distribution of the map quality indices over repeated selection of the calibration sample. In practice this is only feasible by subsampling a large dataset representing the population of interest, or by selecting calibration samples from a map depicting the study variable. This is illustrated with two real-world case studies. In the first case study a quantitative variable, soil organic carbon, is mapped by kriging with an external drift in France, whereas in the second case a categorical variable, land cover, is mapped by random forest in a region in France. The performance of two sampling designs for mapping are compared: simple random sampling and conditioned Latin hypercube sampling, at various sample sizes. We show that in both case studies the sampling distributions of map quality indices obtained with the two sampling design types, for a given sample size, show large variation and largely overlap. This shows that when comparing sampling designs for mapping on the basis of a single sample selected per design, there is a serious risk of an incidental result. Highlights: We provide a method to compare sampling designs for mapping. Random designs for selecting calibration samples should be compared on the basis of the sampling distribution of the map quality indices.</p
Naturally selected Varroa resilient honeybees act as resource for re-wilding
No full textHoney bee colonies naturally selected for cohabitation with Varroa mites can be used as a resource for re-introduction of honey bees in the wild. Here we describe a project started in the Netherlands in 2019 on three locations. So far some colonies now have settled in nest boxes in the wild
Towards a multiscale crop modelling framework for climate change adaptation assessment
No full textPredicting the consequences of manipulating genotype (G) and agronomic management (M) on agricultural ecosystem performances under future environmental (E) conditions remains a challenge. Crop modelling has the potential to enable society to assess the efficacy of G × M technologies to mitigate and adapt crop production systems to climate change. Despite recent achievements, dedicated research to develop and improve modelling capabilities from gene to global scales is needed to provide guidance on designing G × M adaptation strategies with full consideration of their impacts on both crop productivity and ecosystem sustainability under varying climatic conditions. Opportunities to advance the multiscale crop modelling framework include representing crop genetic traits, interfacing crop models with large-scale models, improving the representation of physiological responses to climate change and management practices, closing data gaps and harnessing multisource data to improve model predictability and enable identification of emergent relationships. A fundamental challenge in multiscale prediction is the balance between process details required to assess the intervention and predictability of the system at the scales feasible to measure the impact. An advanced multiscale crop modelling framework will enable a gene-to-farm design of resilient and sustainable crop production systems under a changing climate at regional-to-global scales.</p
How common is avian hybridization on an individual level?
No full textHybridization among different bird species is relatively common, but the hybridization rate of individuals is not well known. Justyn et al. use data from the citizen science project eBird to assess the individual hybridization rate in birds, showing that 0.064% of individuals are hybrids. The accuracy of this new estimate is affected by potential biases introduced by birdwatchers, such as over-reporting of rare hybrids and under-reporting of difficult-to-identify hybrids.</p
Multimeric single-domain antibody complexes protect against bunyavirus infections
Get PDFThe World Health Organization has included three bunyaviruses posing an increasing threat to human health on the Blueprint list of viruses likely to cause major epidemics and for which no, or insufficient countermeasures exist. Here, we describe a broadly applicable strategy, based on llama-derived single-domain antibodies (VHHs), for the development of bunyavirus biotherapeutics. The method was validated using the zoonotic Rift Valley fever virus (RVFV) and Schmallenberg virus (SBV), an emerging pathogen of ruminants, as model pathogens. VHH building blocks were assembled into highly potent neutralizing complexes using bacterial superglue technology. The multimeric complexes were shown to reduce and prevent virus-induced morbidity and mortality in mice upon prophylactic administration. Bispecific molecules engineered to present two different VHHs fused to an Fc domain were further shown to be effective upon therapeutic administration. The presented VHH-based technology holds great promise for the development of bunyavirus antiviral therapies.</p
Improving the chromatographic selectivity of β-lactam residue analysis in milk using phenyl-column chemistry prior to detection by tandem mass spectrometry
No full textAnalyte isobaric interferences can limit the development of a comprehensive analytical method for the quantitative liquid chromatography-tandem mass spectrometry profiling of an important cohort of veterinary drugs. In this work, a selective chromatographic separation was developed for the analysis of 32 β-lactam antibiotic residues (12 penicillins, 14 cephalosporins, five carbapenems and faropenem) in milk samples. A range of analytical columns with different stationary phases and mobile phases were evaluated for retention and separation of the β-lactam compounds. Results showed that, among the columns tested, only phenyl-hexyl could adequately separate ampicillin from cephalexin and amoxicillin from cefadroxil, which had shown isobaric interferences on a number of stationary phases. Chromatography was performed using a water/acetonitrile binary gradient with formic acid and ammonium acetate. The β-lactam residues were extracted from the milk samples using a water:acetonitrile solution and purified by C18 dispersive solid-phase extraction (d-SPE) clean-up, followed by concentration under nitrogen and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) determination. Analytes were monitored in positive electrospray ionisation mode (ESI(+)). Possible interfering matrix effects were overcome by using 13 internal standards. The method was fully validated according to 2002/657/EC guidelines, showing satisfactory performance characteristics. Under within-laboratory reproducibility conditions, trueness and precision ranged from 91 to 130% and from 1.4 to 38.6%, respectively. Decision limits (CCα) were in the range 2.1–133 μg kg−1. Limits of detection (LODs) and quantitation (LOQs) ranged between 0.0090 and 1.5 μg kg−1 and from 0.030 to 5.0 μg kg−1, respectively.</p
“How uncertainties are tackled in multi-disciplinary science? A review of integrated assessments under global change”
No full textThe authors regret the Acknowledgements section was incorrect. The corrected version is provided below: Acknowledgements Pastor A.V. is funded by an EU H2020 project ‘LOCOMOTION – Low carbon society: an enhanced modelling tool for transition to sustainability’. Vieira D.C.S is funded by national funds (OE), through FCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen – DL57/2016 (CDL-CTTRI-97-ARH/2018 – REF.191-97-ARH/2018), and acknowledges CESAM financial support through ( UIDP/50017/2020+UIDB/50017/2020). Soudijn F.H. is funded by the E&P Sound and Marine Life Joint Industry Programme (JIP). We acknowledge the Young Scientific Summer Program (YSSP) 2014 to have brought together three authors of this study. The authors would like to apologise for any inconvenience caused.</p