Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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EmiStatR: a simplified and scalable urban water quality model for simulation of combined sewer overflows
Torres-Matallana, Jairo Arturo ; Leopold, Ulrich ; Klepiszewski, Kai ; Heuvelink, Gerard B.M. - \ 2018
Water 10 (2018)6. - ISSN 2073-4441
Fast surrogate model - Parallel computing - Urban water modelling

Many complex urban drainage quality models are computationally expensive. Complexity and computing times may become prohibitive when these models are used in a Monte Carlo (MC) uncertainty analysis of long time series, in particular for practitioners. Computationally scalable and fast "surrogate" models may reduce the overall computation time for practical applications in which often large data sets would be needed otherwise. We developed a simplified semi-distributed urban water quality model, EmiStatR, which brings uncertainty and sensitivity analyses of urban drainage water quality models within reach of practitioners. Its lower demand in input data and its scalability allow for simulating water volume and pollution loads in combined sewer overflows in several catchments fast and efficiently. The scalable code implemented in EmiStatR reduced the computation time significantly (by a factor of around 24 when using 32 cores). EmiStatR can be applied efficiently to test hypotheses by using MC uncertainty studies or long-term simulations.

Changes in shoot and root architecture of Arabidopsis thaliana by increasing inoculum densities of the cyst nematode Heterodera schachtii
Willig, J. ; Sonneveld, Devon ; Sterken, M.G. ; Lozano Torres, J.L. ; Goverse, A. ; Bakker, J. ; Smant, G. - \ 2018
Some crop varieties show significant loss in biomass even though these are resistant to cyst nematodes. Interestingly, some non-resistant varieties show no symptoms at all. This phenotypical variation is also known as tolerance. In agronomic context, tolerant crop varieties are able to withstand injury and produce acceptable yields. Because of environmental and practical reasons, it is difficult to eradicate below-ground pathogens. Despite the increasing need for tolerance to below-ground pathogens, breeding for tolerance is not yet applied. This has 4 reasons:
1. Disease tolerance for soil-pathogens is difficult to quantify.
2. Unknown if there is enough useful quantitative variation in disease tolerance to soil-pathogens in different ecotypes.
3. The genetic complexity of disease tolerance is not well understood.
4. It is unclear whether disease tolerance has a negative effect on desirable traits.
This research focusses on investigating whether Arabidopsis thaliana could be used as a model plant to detect polymorphic alleles and the recombination or segregation of these alleles that are coding for tolerance.
stUPscales : An R-package for spatio-temporal uncertainty propagation across multiple scales with examples in urbanwater modelling
Torres-Matallana, Jairo Arturo ; Leopold, Ulrich ; Heuvelink, Gerard B.M. - \ 2018
Water 10 (2018)7. - ISSN 2073-4441
Input uncertainty propagation - Space-time ordinary kriging - Spatio-temporal uncertainty characterisation - Temporal aggregation

Integrated environmental modelling requires coupling sub-models at different spatial and temporal scales, thus accounting for change of support procedures (aggregation and disaggregation). We introduce the R-package spatio-temporal Uncertainty Propagation across multiple scales, stUPscales, which constitutes a contribution to state-of-the-art open source tools that support uncertainty propagation analysis in temporal and spatio-temporal domains. We illustrate the tool with an uncertainty propagation example in environmental modelling, specifically in the urban water domain. The functionalities of the class setup and the methods and functions MC.setup, MC.sim, MC.analysis and Agg.t are explained, which are used for setting up, running and analysing Monte Carlo uncertainty propagation simulations, and for spatio-temporal aggregation. We also show how the package can be used to model and predict variables that vary in space and time by using a spatio-temporal variogram model and space-time ordinary kriging. stUPscales takes uncertainty characterisation and propagation a step further by including temporal and spatio-temporal auto- and cross-correlation, resulting in more realistic (spatio-)temporal series of environmental variables. Due to its modularity, the package allows the implementation of additional methods and functions for spatio-temporal disaggregation of model inputs and outputs, when linking models across multiple space-time scales.

The influence of aggregate size fraction and horizon position on microbial community composition
Fox, Aaron ; Ikoyi, Israel ; Torres-Sallan, Gemma ; Lanigan, Gary ; Schmalenberger, Achim ; Wakelin, Steve ; Creamer, Rachel - \ 2018
Applied Soil Ecology 127 (2018). - ISSN 0929-1393 - p. 19 - 29.
Aggregate sized fraction - Bacteria - Community profiling - Fungi - Horizon position - Next generation sequencing
The influence of horizon position and aggregate size on bacterial and fungal community composition was determined. From nine sites, soils were collected from the top three horizon positions (H1, H2 and H3). Physical fractionation separated samples into large macroaggregate (LM, >2000 μm), macroaggregate (MAC, >250 μm), microaggregate (MIC, <250 μm), and silt and clay (SC, 53 μm) fractions. In all samples, the structure of the bacterial and fungal community composition was assessed via restriction fragment length polymorphism (T-RFLP), and for the four aggregate sizes from the top two horizons positions an in-depth analysis of the bacterial community was conducted using next generation sequencing (NGS). Bacterial and fungal communities both differed between aggregate-sizes. Changes in the composition of the bacterial and fungal communities also occurred among horizon positions, with a significant interaction between aggregate size and horizon position evident for the bacterial community. Using NGS, it was shown that aggregate-size had a significant effect on the bacterial community in both horizon positions at both the phyla and family taxonomic levels. MAC and MIC significantly differed in the % relative abundance of bacterial groups, potentially indicating differing predation pressures. These results indicate that both horizon position and aggregate size support distinct microbial communities. Understanding these parameters is critical in our comprehension of the patterns of microbial diversity in soil.
Quantifying in situ phenotypic variability in the hydraulic properties of four tree species across their distribution range in Europe
González-Muñoz, N. ; Sterck, F. ; Torres-Ruiz, J.M. ; Petit, G. ; Cochard, H. ; Arx, G. von; Lintunen, A. ; Caldeira, M.C. ; Capdeville, G. ; Copini, P. ; Gebauer, R. ; Grönlund, L. ; Hölttä, T. ; Lobo-do-Vale, R. ; Peltoniemi, M. ; Stritih, A. ; Urban, J. ; Delzon, S. - \ 2018
PLoS One 13 (2018)5. - ISSN 1932-6203
Many studies have reported that hydraulic properties vary considerably between tree species, but little is known about their intraspecific variation and, therefore, their capacity to adapt to a warmer and drier climate. Here, we quantify phenotypic divergence and clinal variation for embolism resistance, hydraulic conductivity and branch growth, in four tree species, two angiosperms (Betula pendula, Populus tremula) and two conifers (Picea abies, Pinus sylvestris), across their latitudinal distribution in Europe. Growth and hydraulic efficiency varied widely within species and between populations. The variability of embolism resistance was in general weaker than that of growth and hydraulic efficiency, and very low for all species but Populus tremula. In addition, no and weak support for a safety vs. efficiency trade-off was observed for the angiosperm and conifer species, respectively. The limited variability of embolism resistance observed here for all species except Populus tremula, suggests that forest populations will unlikely be able to adapt hydraulically to drier conditions through the evolution of embolism resistance.
The Ozone Monitoring Instrument : Overview of 14 years in space
Levelt, Pieternel F. ; Joiner, Joanna ; Tamminen, Johanna ; Veefkind, J.P. ; Bhartia, Pawan K. ; Zweers, Deborah C.S. ; Duncan, Bryan N. ; Streets, David G. ; Eskes, Henk ; Der, Ronald A. Van; McLinden, Chris ; Fioletov, Vitali ; Carn, Simon ; Laat, Jos De; Deland, Matthew ; Marchenko, Sergey ; McPeters, Richard ; Ziemke, Jerald ; Fu, Dejian ; Liu, Xiong ; Pickering, Kenneth ; Apituley, Arnoud ; Abad, Gonzalo González ; Arola, Antti ; Boersma, Folkert ; Miller, Christopher Chan ; Chance, Kelly ; Graaf, Martin De; Hakkarainen, Janne ; Hassinen, Seppo ; Ialongo, Iolanda ; Kleipool, Quintus ; Krotkov, Nickolay ; Li, Can ; Lamsal, Lok ; Newman, Paul ; Nowlan, Caroline ; Suleiman, Raid ; Tilstra, Lieuwe Gijsbert ; Torres, Omar ; Wang, Huiqun ; Wargan, Krzysztof - \ 2018
Atmospheric Chemistry and Physics 18 (2018)8. - ISSN 1680-7316 - p. 5699 - 5745.
This overview paper highlights the successes of the Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years. Data from OMI has been used in a wide range of applications and research resulting in many new findings. Due to its unprecedented spatial resolution, in combination with daily global coverage, OMI plays a unique role in measuring trace gases important for the ozone layer, air quality, and climate change. With the operational very fast delivery (VFD; direct readout) and near real-time (NRT) availability of the data, OMI also plays an important role in the development of operational services in the atmospheric chemistry domain.
Genome-wide association mapping of the architecture of susceptibility to the root-knot nematode Meloidogyne incognita in Arabidopsis thaliana
Warmerdam, S. ; Sterken, M.G. ; Schaik, C.C. van; Oortwijn, M.E.P. ; Sukarta, O.C.A. ; Lozano Torres, J.L. ; Dicke, M. ; Helder, J. ; Kammenga, J.E. ; Goverse, A. ; Bakker, J. ; Smant, G. - \ 2018
Heligmosomoides polygyrus Venom Allergen-like Protein-4 (HpVAL-4) is a sterol binding protein
Asojo, Oluwatoyin A. ; Darwiche, Rabih ; Gebremedhin, Selam ; Smant, Geert ; Lozano-Torres, Jose L. ; Drurey, Claire ; Pollet, Jeroen ; Maizels, Rick M. ; Schneiter, Roger ; Wilbers, Ruud H.P. - \ 2018
International Journal for Parasitology 48 (2018)5. - ISSN 0020-7519 - p. 359 - 369.
Heligmosomoides polygyrus bakeri is a model parasitic hookworm used to study animal and human helminth diseases. During infection, the parasite releases excretory/secretory products that modulate the immune system of the host. The most abundant protein family in excretory/secretory products comprises the venom allergen-like proteins (VALs), which are members of the SCP/TAPS (sperm-coating protein/ Tpx/antigen 5/pathogenesis related-1/Sc7) superfamily. There are >30 secreted Heligmosomoides polygyrus VAL proteins (HpVALs) and these proteins are characterised by having either one or two 15 kDa CAP (cysteine-rich secretory protein (CRISP)/antigen 5/pathogenesis related-1) domains. The first known HpVAL structure, HpVAL-4, refined to 1.9 Å is reported. HpVAL-4 was produced as a homogeneously glycosylated protein in leaves of Nicotiana benthamiana infiltrated with recombinant plasmids, making this plant expression platform amenable for the production of biological products. The overall topology of HpVAL-4 is a three layered aba sandwich between a short N-terminal loop and a C-terminal cysteine rich extension. The C-terminal cysteine rich extension has two strands stabilized by two disulfide bonds and superposes well with the previously reported extension from the human hookworm Necator americanus Ancylostoma secreted protein-2 (Na-ASP-2). The N-terminal loop is connected to alpha helix 2 via a disulfide bond previously observed in Na-ASP-2. HpVAL-4 has a central cavity that is more similar to the Nterminal CAP domain of the two CAP Na-ASP-1 from Necator americanus. Unlike Na-ASP-2, mammalian CRISP, and the C-terminal CAP domain of Na-ASP-1, the large central cavity of HpVAL-4 lacks the two histidines required to coordinate divalent cations. HpVAL-4 has both palmitate-binding and sterol-binding cavities and is able to complement the in vivo sterol export phenotype of yeast mutants lacking their endogenous CAP proteins. More studies are required to determine endogenous binding partners of HpVAL-4 and unravel the possible impact of sterol binding on immune-modulatory functions.
Genome-wide association mapping of the architecture of susceptibility to the root-knot nematode Meloidogyne incognita in Arabidopsis thaliana
Warmerdam, Sonja ; Sterken, Mark G. ; Schaik, Casper van; Oortwijn, Marian E.P. ; Sukarta, Octavina C.A. ; Lozano-Torres, Jose L. ; Dicke, Marcel ; Helder, Johannes ; Kammenga, Jan E. ; Goverse, Aska ; Bakker, Jaap ; Smant, Geert - \ 2018
New Phytologist 218 (2018)2. - ISSN 0028-646X - p. 724 - 737.
Susceptibility to the root-knot nematode Meloidogyne incognita in plants is thought to be a complex trait based on multiple genes involved in cell differentiation, growth and defence. Previous genetic analyses of susceptibility to M. incognita have mainly focused on segregating dominant resistance genes in crops. It is not known if plants harbour significant genetic variation in susceptibility to M. incognita independent of dominant resistance. To study the genetic architecture of susceptibility to M. incognita, we analysed nematode reproduction on a highly diverse set of 340 natural inbred lines of Arabidopsis thaliana with genome-wide association mapping. We observed a surprisingly large variation in nematode reproduction among these lines. Genome-wide association mapping revealed four quantitative trait loci (QTLs) located on chromosomes 1 and 5 of A. thaliana significantly associated with reproductive success of M. incognita, none of which harbours typical resistance gene homologues. Mutant analysis of three genes located in two QTLs showed that the transcription factor BRASSINAZOLE RESISTANT1 and an F-box family protein may function as (co-)regulators of susceptibility to M. incognita in Arabidopsis.
Our data suggest that breeding for loss-of-susceptibility, based on allelic variants critically involved in nematode feeding, could be used to make crops more resilient to root-knot nematodes.
Fire effects and ecological recovery pathways of tropical montane cloud forests along a time chronosequence
Oliveras, Imma ; Román-Cuesta, Rosa M. ; Urquiaga-Flores, Erickson ; Quintano Loayza, Jose A. ; Kala, Jose ; Huamán, Vicky ; Lizárraga, Nohemi ; Sans, Guissela ; Quispe, Katia ; Lopez, Efrain ; Lopez, David ; Cuba Torres, Israel ; Enquist, Brian J. ; Malhi, Yadvinder - \ 2018
Global Change Biology 24 (2018)2. - ISSN 1354-1013 - p. 758 - 772.
carbon allocation - forest structure - metabolic scaling theory - regeneration - species diversity
Tropical montane cloud forests (TMCFs) harbour high levels of biodiversity and large carbon stocks. Their location at high elevations make them especially sensitive to climate change, because a warming climate is enhancing upslope species migration, but human disturbance (especially fire) may in many cases be pushing the treeline downslope. TMCFs are increasingly being affected by fire, and the long-term effects of fire are still unknown. Here, we present a 28-year chronosequence to assess the effects of fire and recovery pathways of burned TMCFs, with a detailed analysis of carbon stocks, forest structure and diversity. We assessed rates of change of carbon (C) stock pools, forest structure and tree-size distribution pathways and tested several hypotheses regarding metabolic scaling theory (MST), C recovery and biodiversity. We found four different C stock recovery pathways depending on the selected C pool and time since last fire, with a recovery of total C stocks but not of aboveground C stocks. In terms of forest structure, there was an increase in the number of small stems in the burned forests up to 5–9 years after fire because of regeneration patterns, but no differences on larger trees between burned and unburned plots in the long term. In support of MST, after fire, forest structure appears to approximate steady-state size distribution in less than 30 years. However, our results also provide new evidence that the species recovery of TMCF after fire is idiosyncratic and follows multiple pathways. While fire increased species richness, it also enhanced species dissimilarity with geographical distance. This is the first study to report a long-term chronosequence of recovery pathways to fire suggesting faster recovery rates than previously reported, but at the expense of biodiversity and aboveground C stocks.
Effects of soil type and depth on carbon distribution within soil macroaggregates from temperate grassland systems
Torres-Sallan, Gemma ; Creamer, Rachel E. ; Lanigan, Gary J. ; Reidy, Brian ; Byrne, Kenneth A. - \ 2018
Geoderma 313 (2018). - ISSN 0016-7061 - p. 52 - 56.
Grassland - Soil aggregation - Soil organic carbon - Subsoil

Grassland soils have been highlighted as a global soil carbon (C) sink, and have the potential to sequester additional C. Sequestration of C can occur through incorporation of soil organic carbon (SOC) within microaggregates and the silt and clay fractions. The distribution of SOC within macroaggregate fractions gives an insight into both SOC dynamics and its incorporation into the soil. Research to date on soil C has tended to focus on the topsoil (0–30 cm). While many studies have assessed the changes in aggregation and SOC dynamics after land use or management change, this paper assesses aggregation and SOC dynamics in the topsoil and subsoil of twenty-one temperate grassland sites covering four soil types (Haplic Luvisol, Haplic Stagnosol, Haplic Cambisol, Stagnic Cambisol). Results show that there are no differences in SOC between soil types in the surface 0–30 cm, except a decrease in the quantity of microaggregates within macroaggregates in Haplic Stagnosols. In the subsoil, the silt and clay fraction of clay-illuviated soils had a lower percentage of SOC. Soils with clay illuviation and reducing conditions had a decreased proportion of SOC in microaggregates and silt plus clay within small macroaggregates in the subsoil. This could be caused by a combination of (i) reduced incorporation of SOC into smaller fractions, because POM inputs could be limited due to soil saturation limiting root growth, and (ii) reduced mineralisation and subsequent incorporation of POM into microaggregates and silt plus clay within macroaggregates. These results enable elucidation of the mechanisms driving aggregate formation (and thus C sequestration in microaggregates and silt plus clay fractions) in topsoil and subsoil. This study shows that the dynamics of SOC in subsoil horizons is soil-type dependant and that differences between soil types cannot be elucidated when the sampling is limited to 30 cm. This suggests that the IPCC guidelines for SOC measurements should also include the sampling of subsoil horizons in order to get valuable information that allows discerning between soil types.

Lower tier toxicity risk assessment of agriculture pesticides detected on the Río Madre de Dios watershed, Costa Rica
Arias-Andrés, M. ; Rämö, R. ; Mena Torres, F. ; Ugalde, R. ; Grandas, L. ; Ruepert, C. ; Castillo, L.E. ; Den Brink, P.J. van; Gunnarsson, J.S. - \ 2018
Environmental Science and Pollution Research 25 (2018)14. - ISSN 0944-1344 - p. 13312 - 13321.
Ecotoxicology - Pesticides - Risk assessment - Tropics

Costa Rica is a tropical country with one of the highest biodiversity on Earth. It also has an intensive agriculture, and pesticide runoff from banana and pineapple plantations may cause a high toxicity risk to non-target species in rivers downstream the plantations. We performed a first tier risk assessment of the maximum measured concentrations of 32 pesticides detected over 4 years in the River Madre de Dios (RMD) and its coastal lagoon on the Caribbean coast of Costa Rica. Species sensitivity distributions (SSDs) were plotted in order to derive HC5 values for each pesticide, i.e., hazard concentrations for 5 % of the species, often used as environmental criteria values in other countries. We also carried out toxicity tests for selected pesticides with native Costa Rican species in order to calculate risk coefficients according to national guidelines in Costa Rica. The concentrations of herbicides diuron and ametryn and insecticides carbofuran, diazinon, and ethoprophos exceeded either the HC5 value or the lower limit of its 90 % confidence interval suggesting toxic risks above accepted levels. Risk coefficients of diuron and carbofuran derived using local guidelines indicate toxicity risks as well. The assessed fungicides did not present acute toxic risks according to our analysis. Overall, these results show a possible toxicity of detected pesticides to aquatic organisms and provide a comparison of Costa Rican national guidelines with more refined methods for risk assessment based on SSDs. Further higher tier risk assessments of pesticides in this watershed are also necessary in order to consider pesticide water concentrations over time, toxicity from pesticide mixtures, and eventual effects on ecosystem functions.

A new reference genome sequence for genotyping virulence in continental European field populations of Globodera pallida
Holterman, M.H.M. ; Blokhina, T. ; Elsen, S.J.J. van den; Lozano Torres, J.L. ; Smant, G. ; Helder, J. - \ 2017
Plant-parasitic nematodes form an increasingly important problem in agriculture, causing significant crop losses worldwide. The majority of these losses are caused by a small number of species, such as cyst nematodes (e.g., Globodera rostochiensis and G. pallida), root-knot nematodes (Meloidogyne spp.) and stem nematodes (Ditylenchus spp.). With a regulatory ban on most nematicidal agrochemicals, the main method of control at the moment is the use of resistant crop cultivars. However, the current spectrum of nematode resistance genes used in major crops is extremely narrow. Prolonged exposure of field populations to a narrow range of resistance genes can result in the appearance of nematode genotypes with modified virulence characteristics.
To better understand the genetic mechanisms underlying selection for virulence in the potato cyst nematode G. pallida in the Netherlands, we needed to generate a new reference genome. For this, we deliberately chose an old isolate; a population that had not been exposed to potato cultivars harbouring the resistance genes that were most widely used over the past thirty years. We generated a new genome sequence of this G. pallida isolate with PacBio sequencing technology. This resulted in a new genome sequence which consists of significantly fewer and longer contigs than the publicly available genome sequence of this species. An automated procedure was used to create an initial annotation. After a further manual refinement of the annotation with a particular focus on effector families, this genome sequence will serve as a reference for the elucidation of virulence characteristics in G. pallida populations from The Netherlands and surrounding countries.
Improving sustainability of maize to ethanol processing by plant breeding and process optimization
Slegers, P.M. ; Torres Salvador, A.F. ; Boxtel, A.J.B. van; Trindade, L.M. - \ 2017
In: Proceedings of the 25th European Biomass Conference. - Stockholm : EUBCE (European Biomass Conference and Exhibition Proceedings ) - ISBN 9788889407172 - p. 1031 - 1033.
Efficient management of plant resources is essential for a sustainable biobased economy. The biomass conversion efficiency and sustainability performance depend greatly on the choice of feedstock and the applied processing technology. The aim of this research was to enhance the biomass use of maize stover for bioethanol production, by combining plant breeding of the maize feedstock with various pretreatment severities and applying an exploratory assessment of the environmental and economic impacts. We found that systematic genetic gains of cell wall digestibility can lead to significant advances in the total glucose productivity and also in the sustainability performance. The best maize characteristics tested led to a total glucose productivity of 3.7 ton per hectare using mild processing conditions. This matches the highest realizable yields under severe processing conditions. In the best scenarios the environmental and economic impacts of operating conditions were reduced by 15% compared to the benchmark.
Scientific opinion on the evaluation of substances as acceptable previous cargoes for edible fats and oils
Knutsen, Helle Katrine ; Alexander, Jan ; Barregård, Lars ; Bignami, Margherita ; Brüschweiler, Beat ; Ceccatelli, Sandra ; Cottrill, Bruce ; Dinovi, Michael ; Edler, Lutz ; Hogstrand, Christer ; Hoogenboom, L.A.P. ; Nebbia, Carlo ; Oswald, Isabelle ; Petersen, Annette ; Rose, Martin ; Roudot, Alain-Claude ; Schwerdtle, Tanja ; Vollmer, Günter ; Wallace, Heather ; Grasl-Kraupp, Bettina ; Grob, Konrad ; Penninks, André ; Binaglia, Marco ; Roldán Torres, Ruth ; Vleminckx, Christiane - \ 2017
EFSA Journal 15 (2017)1. - ISSN 1831-4732
Shipping of edible fats and oils into Europe is permitted in bulk tanks, provided that the previous cargo is included in a positive list. The European Commission requested EFSA to evaluate the acceptability as previous cargoes for fats and oils the substances calcium lignosulphonate, methyl acetate, ethyl tert-butyl ether (ETBE) and ammonium sulphate. The evaluation was based on the same criteria as those used for the evaluation of the substances currently on the list in the Annex to Commission Directive 96/3/EC as acceptable previous cargoes for edible fats and oils. Methyl acetate and ETBE meet the criteria for acceptability as previous cargoes. Due to uncertainties, mainly with regard to the composition and toxicity of the low molecular mass fraction, and the fact that the toxicological database is limited to the 40–65 grade and does not cover all grades of calcium lignosulphonate shipped as previous cargoes, the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) concluded that calcium lignosulphonate does not meet the criteria for acceptability as a previous cargo. Only food-grade ammonium sulphate meets the criteria for acceptability as a previous cargo due to uncertainties about impurities in other (non-food) grades.
Scientific opinion: Risks for animal health related to the presence of zearalenone and its modified forms in feed
Knutsen, Helle-Katrine ; Alexander, Jan ; Barregård, Lars ; Bignami, Margherita ; Brüschweiler, Beat ; Ceccatelli, Sandra ; Cottrill, Bruce ; Dinovi, Michael ; Edler, Lutz ; Grasl-Kraupp, Bettina ; Hogstrand, Christer ; Hoogenboom, L.A.P. ; Nebbia, Carlo Stefano ; Petersen, Annette ; Rose, Martin ; Roudot, Alain-Caude ; Schwerdtle, Tanja ; Vleminckx, Christiane ; Vollmer, Günter ; Wallace, Heather ; Dall'asta, Chiara ; Dänicke, Sven ; Eriksen, Gunnar-Sundstøl ; Altieri, Andrea ; Roldán-Torres, Ruth ; Oswald, Isabelle P. - \ 2017
EFSA Journal 15 (2017)7. - ISSN 1831-4732
Zearalenone (ZEN), a mycotoxin primarily produced by Fusarium fungi, occurs predominantly in cereal grains. The European Commission asked EFSA for a scientific opinion on the risk to animal health related to ZEN and its modified forms in feed. Modified forms of ZEN occurring in feed include phase I metabolites α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL), zearalanone (ZAN) and phase II conjugates. ZEN has oestrogenic activity and the oestrogenic activity of the modified forms of ZEN differs considerably. For ZEN, the EFSA Panel on Contaminants in the Food Chain (CONTAM) established no observed adverse effect levels (NOAELs) for pig (piglets and gilts), poultry (chicken and fattening turkeys), sheep and fish (extrapolated from carp) and lowest observed effect level (LOAEL) for dogs. No reference points could be established for cattle, ducks, goats, horses, rabbits, mink and cats. For modified forms, no reference points could be established for any animal species and relative potency factors previously established from rodents by the CONTAM Panel in 2016 were used. The dietary exposure was estimated on 17,706 analytical results with high proportions of left-censored data (ZEN about 60%, ZAN about 70%, others close to 100%). Samples for ZEN were collected between 2001 and 2015 in 25 different European countries, whereas samples for the modified forms were collected mostly between 2013 and 2015 from three Member States. Based on exposure estimates, the risk of adverse health effects of feed containing ZEN was considered extremely low for poultry and low for sheep, dog, pig and fish. The same conclusions also apply to the sum of ZEN and its modified forms.
Exploring the relationships between the components of argumentation competence and their relationships with domain-specific knowledge
Valero Haro, A. ; Noroozi, O. ; Biemans, H.J.A. ; Mulder, M. - \ 2017
In: EDULEARN17 proceedings. - IATED - ISBN 9788469737774 - p. 3954 - 3954.
Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes
Shah, Syed Jehangir ; Anjam, Muhammad Shahzad ; Mendy, Badou ; Anwer, Muhammad Arslan ; Habash, Samer S. ; Lozano-Torres, Jose L. ; Grundler, Florian M.W. ; Siddique, Shahid - \ 2017
Journal of Experimental Botany 68 (2017)21-22. - ISSN 0022-0957 - p. 5949 - 5960.
When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in plant–nematode interactions remain unexplored. Here, we characterized the role of a group of cell wall receptor proteins in Arabidopsis, designated as polygalacturonase-inhibiting proteins (PGIPs), during infection with the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. PGIPs are encoded by a family of two genes in Arabidopsis, and are involved in the formation of active OG elicitors. Our results show that PGIP gene expression is strongly induced in response to cyst nematode invasion of roots. Analyses of loss-of-function mutants and overexpression lines revealed that PGIP1 expression attenuates infection of host roots by cyst nematodes, but not root-knot nematodes. The PGIP1-mediated attenuation of cyst nematode infection involves the activation of plant camalexin and indole-glucosinolate pathways. These combined results provide new insights into the molecular mechanisms underlying plant damage perception and response pathways during infection by cyst and root-knot nematodes, and establishes the function of PGIP in plant resistance to cyst nematodes.
Multivariate autoregressive modelling and conditional simulation of precipitation time series for urban water models
Torres-Matallana, J.A. ; Leopold, U. ; Heuvelink, G.B.M. - \ 2017
European Water 57 (2017). - p. 299 - 306.
Precipitation is the most active flux and major input of hydrological systems. Precipitation controls hydrological states (soil moisture and groundwater level), and fluxes (runoff, evapotranspiration and groundwater recharge).
Hence, precipitation plays a paramount role in urban water systems. It controls the fluxes towards combined sewer tanks and the dilution of chemical and organic compounds in the wastewater. Furthermore, small catchments (i.e.,
areas of about 20 ha) have a fast response to precipitation. Therefore, catchment average precipitation is a key component in urban water models. However, average catchment precipitation is not always accurately known when
measured at rain gauges, because the location of the gauge might be outside the catchment boundaries or does not reflect the entire catchment. The objective of this paper is to develop a method to estimate the precipitation in a
catchment given a known precipitation time series at a location outside of the catchment, while quantifying the uncertainty associated with the estimation. We developed a multivariate autoregressive time series model for conditional simulation of precipitation time series. The case study is a small sub-catchment (16.5 ha) in Luxembourg.The time series of precipitation outside of the sub-catchment are available for two stations and cover the year 2010.
We calibrated the model using the R-package ‘mAr’ and applied the developed conditional simulation algorithm to generate multiple realisations of precipitation time series. The results show that the proposed method is suitable to estimate time series of precipitation at ungauged sites and can quantify the associated uncertainty.
A values-based approach to exploring synergies between livestock farming and landscape conservation in Galicia (Spain)
Swagemakers, Paul ; Garcia, Maria Dolores Dominguez ; Torres, Amanda Onofa ; Oostindie, Henk ; Groot, Jeroen C.J. - \ 2017
Sustainability 9 (2017)11. - ISSN 2071-1050
Ecological capital - Farming styles - Natural resource management - Rural development
The path to sustainable development involves creating coherence and synergies in the complex relationships between economic and ecological systems. In sustaining their farm businesses farmers' differing values influence their decisions about agroecosystem management, leading them to adopt diverging farming practices. This study explores the values of dairy and beef cattle farmers, the assumptions that underpin them, and the various ways that these lead farmers to combine food production with the provision of other ecosystem services, such as landscape conservation and biodiversity preservation. This paper draws on empirical research from Galicia (Spain), a marginal and mountainous European region whose livestock production system has undergone modernization in recent decades, exposing strategic economic, social and ecological vulnerabilities. It applies a Q-methodology to develop a values-based approach to farming. Based on a sample of 24 livestock farmers, whose practices promote landscape conservation and/or biodiversity preservation, the Q-methodology allowed us to identify four 'farming styles'. Further analysis of the practices of the farmers in these groups, based on additional farm data and interview material, suggests that all 24 farmers valorize landscape and nature and consider cattle production and nature conservation to be compatible within their own farm practices. However, the groups differed in the extent to which they have developed synergies between livestock farming and landscape conservation. We conclude by discussing how rural development policy in Galicia could strengthen such practices by providing incentives to farmers and institutionally embedding a shift towards more diversified farming and product development.
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