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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    Zonder vaccinatie geen kinderopvang : Mazelen op de kinderopvang: voorkom noodmaatregelen maar kies niet voor schijnveiligheid.
    Verweij, M.F. ; Pierik, R. - \ 2019
    De Volkskrant (2019).
    Kamer, wat gaan we doen als de vaccinatiegraad verder daalt? : Opinie
    Verweij, M.F. ; Pierik, R. - \ 2019
    Trouw (2019). - p. 21 - 21.
    Wetsvoorstel vaccinatie spant het paard achter de wagen : Opinieartikel over D66 wetsvoorstel over vaccinatie in de kinderopvang
    Verweij, M.F. ; Pierik, R. - \ 2019
    Trouw (2019).
    Een vertrouwenswaardig vaccinatiebeleid
    Verweij, M.F. - \ 2019
    In: Hoe nu verder met de vaccinatietwijfel? / Pierik, Roland, Universiteit van Amsterdam - ISBN 9789090317144 - p. 43 - 45.
    Vaccinatie op de kinderopvang : Een wetsvoorstel dat tekort schiet, en een alternatief
    Pierik, R. ; Verweij, M.F. - \ 2019
    Nederlands Juristenblad (2019)21. - ISSN 0165-0483 - p. 1523 - 1590.
    De registratie van vaccinatiegegevens in de kinderopvang binnen het regime van de Algemene Verordening Gegevensbescherming
    Evers, G.H. ; Pierik, R.H.M. ; Verweij, M.F. - \ 2019
    Privacy & Informatie (2019)4. - ISSN 1388-0241 - p. 130 - 136.
    Actuele ontwikkeling resultaten en inkomens in land-en tuinbouw 2019
    Hietbrink, Olaf ; Pierik, C. ; Meulen, Harold van der - \ 2019
    Far-red radiation increases dry mass partitioning to fruits but reduces Botrytis cinerea resistance in tomato
    Ji, Yongran ; Ouzounis, Theoharis ; Courbier, Sarah ; Kaiser, Elias ; Nguyen, Phuong T. ; Schouten, Henk J. ; Visser, Richard G.F. ; Pierik, Ronald ; Marcelis, Leo F.M. ; Heuvelink, Ep - \ 2019
    Environmental and Experimental Botany 168 (2019). - ISSN 0098-8472
    Botrytis cinerea - Dry mass partitioning - Far red - Growth component analysis - LED lighting - Solanum lycopersicum

    The addition of far-red (FR, 700–800 nm) radiation to standard growth light triggers a set of photomorphogenic responses collectively termed shade avoidance syndrome. Recent research showed that additional FR increased fruit yield in greenhouse tomato production. However, the mechanism behind this increase is not clear; nor is it known whether there is a trade-off between growth and defense against plant diseases in tomato under additional FR. The aims of this study were 1) to quantify the effect of additional FR on tomato fruit growth, 2) to explain this effect based on underlying growth components and 3) to examine the FR effect on resistance against the necrotrophic fungus Botrytis cinerea. Tomato (Solanum lycopersicum ‘Moneymaker’) plants were grown for four months with 30 or 50 μmol m−2 s−1 of FR added to 150 μmol m−2 s−1 red + blue or white background LED lighting. Growth and development parameters were recorded, and a growth component analysis was conducted. Bioassays for resistance against B. cinerea were conducted on leaf samples collected from each light treatment. Additional FR increased total fruit dry mass per plant by 26–45%. FR affected multiple growth components, among which the fraction of dry mass partitioned to fruits was the most prominent with a 15–35% increase. Truss appearance rate was increased 11–14% by FR while instantaneous net photosynthesis rate was not affected. FR also resulted in more severe disease symptoms upon infection with B. cinerea. In conclusion, additional FR increases tomato fruit production mainly by increasing dry mass partitioning to fruits, rather than improving photosynthesis or increasing total plant biomass. However, FR also reduces resistance of tomato leaves against B. cinerea.

    Variation in plastic responses to light results from selection in different competitive environments-A game theoretical approach using virtual plants
    Bongers, Franca J. ; Douma, Jacob C. ; Iwasa, Yoh ; Pierik, Ronald ; Evers, Jochem B. ; Anten, Niels P.R. - \ 2019
    PLoS Computational Biology 15 (2019)8. - ISSN 1553-734X - p. e1007253 - e1007253.

    Phenotypic plasticity is a vital strategy for plants to deal with changing conditions by inducing phenotypes favourable in different environments. Understanding how natural selection acts on variation in phenotypic plasticity in plants is therefore a central question in ecology, but is often ignored in modelling studies. Here we present a new modelling approach that allows for the analysis of selection for variation in phenotypic plasticity as a response strategy. We assess selection for shade avoidance strategies of Arabidopsis thaliana in response to future neighbour shading signalled through a decrease in red:far-red (R:FR) ratio. For this, we used a spatially explicit 3D virtual plant model that simulates individual Arabidopsis plants competing for light in different planting densities. Plant structure and growth were determined by the organ-specific interactions with the light environment created by the vegetation structure itself. Shade avoidance plastic responses were defined by a plastic response curve relating petiole elongation and lamina growth to R:FR perceived locally. Different plasticity strategies were represented by different shapes of the response curve that expressed different levels of R:FR sensitivity. Our analyses show that the shape of the selected shade avoidance strategy varies with planting density. At higher planting densities, more sensitive response curves are selected for than at lower densities. In addition, the balance between lamina and petiole responses influences the sensitivity of the response curves selected for. Combining computational virtual plant modelling with a game theoretical analysis represents a new step towards analysing how natural selection could have acted upon variation in shade avoidance as a response strategy, which can be linked to genetic variation and underlying physiological processes.

    Soil Salinity Limits Plant Shade Avoidance
    Hayes, Scott ; Pantazopoulou, Chrysoula K. ; Gelderen, Kasper van; Reinen, Emilie ; Tween, Adrian Louis ; Sharma, Ashutosh ; Vries, Michel de; Prat, Salomé ; Schuurink, Robert C. ; Testerink, Christa ; Pierik, Ronald - \ 2019
    Current Biology 29 (2019)10. - ISSN 0960-9822 - p. 1669 - 1676.e4.
    abscisic acid - brassinosteroids - phytochrome - phytohormones - PIF - plant photobiology - salt response - salt stress

    Global food production is set to keep increasing despite a predicted decrease in total arable land [1]. To achieve higher production, denser planting will be required on increasingly degraded soils. When grown in dense stands, crops elongate and raise their leaves in an effort to reach sunlight, a process termed shade avoidance [2]. Shade is perceived by a reduction in the ratio of red (R) to far-red (FR) light and results in the stabilization of a class of transcription factors known as PHYTOCHROME INTERACTING FACTORS (PIFs) [3, 4]. PIFs activate the expression of auxin biosynthesis genes [4, 5] and enhance auxin sensitivity [6], which promotes cell-wall loosening and drives elongation growth. Despite our molecular understanding of shade-induced growth, little is known about how this developmental program is integrated with other environmental factors. Here, we demonstrate that low levels of NaCl in soil strongly impair the ability of plants to respond to shade. This block is dependent upon abscisic acid (ABA) signaling and the canonical ABA signaling pathway. Low R:FR light enhances brassinosteroid (BR) signaling through BRASSINOSTEROID SIGNALING KINASE 5 (BSK5) and leads to the activation of BRI1 EMS SUPPRESSOR 1 (BES1). ABA inhibits BSK5 upregulation and interferes with GSK3-like kinase inactivation by the BR pathway, thus leading to a suppression of BES1:PIF function. By demonstrating a link between light, ABA-, and BR-signaling pathways, this study provides an important step forward in our understanding of how multiple environmental cues are integrated into plant development. Intensively farmed crops often experience multiple stresses simultaneously. Here, Hayes et al. show that low-level soil salinity suppresses shade avoidance in plants. Through investigation of the mechanisms underlying this trait, they uncover a regulatory pathway that converges at the level of brassinosteroid signaling.

    Maak vaccinatie verplicht
    Verweij, M.F. ; Pierik, R. - \ 2018
    De Volkskrant (2018).
    Geen vaccinatie, geen kinderopvang
    Verweij, M.F. ; Pierik, R. - \ 2018
    Nederlands Dagblad (2018). - ISSN 1570-7970
    Verplicht vaccineren: de tijd van vrijblijvendheid is voorbij
    Verweij, M.F. ; Pierik, R. - \ 2018
    NRC (2018).
    Angst voor Vaccinatie nu betekent later veel doden
    Verweij, M.F. ; Pierik, R. - \ 2018
    Algemeen Dagblad (2018).
    OP002 Assessment of disease activity patterns during the first 10 years after diagnosis in a population-based Crohn’s disease cohort shows a quiescent disease course for a substantial proportion of the population
    Wintjens, D. ; Bergey, F. ; Saccenti, E. ; Jeuring, S. ; Romberg-Camps, M. ; Oostenbrug, L. ; Masclee, A. ; Jonkers, D. ; Martins Dos Santos, V. ; Pierik, M. - \ 2018
    Journal of Crohn's and Colitis 12 (2018)supplement 1. - ISSN 1873-9946 - p. S001 - S003.
    Background Representative studies concerning the long-term prognosis and disease course in Crohn’s disease (CD) primarily describe steroid exposure, need for surgery or hospitalisations, and disease progression as characteristics of an unfavourable outcome. Real-life data on long-term disease activity are lacking. We aimed to define clusters with different disease activity patterns in the population-based IBDSL cohort. Methods All CD patients from the IBDSL cohort with at least 10 years follow-up (>18 years, diagnosed between 1991 and 2004) were included. Data on demographics, disease phenotype, medication use, hospitalisations, and surgery were available. In addition, all endoscopy and imaging reports were scrutinised. Since diagnosis, active disease was defined for each yearly quarter by (i) active disease on endoscopy or imaging, (ii) hospitalisation, (iii) surgery, or (iv) treatment adjustment for increased symptoms. Subsequently, formula-based clusters were generated based on four previously published questionnaire-based disease activity patterns,1 completed with two additional clusters (Figure 1). Prediction models were created using discriminant analysis with PLS regression based on characteristics at baseline and 6 months after diagnosis. Results In total, 432 patients were included. During 10 years follow-up after diagnosis, patients experienced 4.2 (SD 3.8) quarters of active disease on average. The distribution of patients over different clusters is shown in Figure 1. Notably, 128 patients (29.6%) were classified as quiescent and, of these, 89.8% never received immunomodulators or biologics. Ileocolonic disease location (OR 0.45; 95% CI 0.21–0.91) and smoking at diagnosis (OR 0.44; 95% CI 0.26–0.70) were negatively associated with a quiescent disease course, while surgery at diagnosis (OR 3.02; 95% CI 1.39–6.64) was positively associated. Our best prediction model for a quiescent course had an area under the ROC curve of 0.72 (p < 0.001) at baseline and 0.75 (p < 0.001) at 6 months after diagnosis.
    Holocene drift-sand activity in the Netherlands
    Pierik, Harm J. ; Lanen, Rowin J. van; Gouw-Bouman, Marjolein T.I.J. ; Groenewoudt, Bert J. ; Wallinga, J. ; Hoek, Wim Z. - \ 2018
    drift sand activity - stuifzandvoorkomen
    This dataset contains a new national overview of the occurrence of drift sand activity in the Netherlands from ca. 5000 BC to AD 1700. The dataset has been compiled from overview studies, field studies and new data.
    Controls on late-Holocene drift-sand dynamics : The dominant role of human pressure in the Netherlands
    Pierik, Harm J. ; Lanen, Rowin J. van; Gouw-Bouman, Marjolein T.I.J. ; Groenewoudt, Bert J. ; Wallinga, Jakob ; Hoek, Wim Z. - \ 2018
    Holocene 28 (2018)9. - ISSN 0959-6836 - p. 1361 - 1381.
    chronology - climate - drift-sand activity - Holocene - human impact - vegetation development

    Holocene drift-sand activity in the northwest European sand belt is commonly directly linked to population pressure (agricultural activity) or to climate change (e.g. storminess). In the Pleistocene sand areas of the Netherlands, small-scale Holocene drift-sand activity began in the Mesolithic, whereas large-scale sand drifting started during the Middle Ages. This last phase not only coincides with the intensification of farming and demographic pressure but also is commonly associated with a colder climate and enhanced storminess. This raises the question to what extent drift-sand activity can be attributed to either human activities or natural forcing factors. In this study, we compare the spatial and temporal patterns of drift-sand occurrence for the four characteristic Pleistocene sand regions in the Netherlands for the period between 1000 BC and AD 1700. To this end, we compiled a new supra-regional overview of drift-sand activity based on age estimates (14C, optically stimulated luminescence (OSL), archaeological and historical ages). The occurrence of sand drifting was then compared in time and space with historical-route networks, relative vegetation openness and climate. Results indicate a constant but low drift-sand activity between 1000 BC and AD 1000, interrupted by a remarkable decrease in activity around the BC/AD transition. It is evident that human pressure on the landscape was most influential on initiating sand drifting: this is supported by more frequent occurrences close to routes and the uninterrupted increase of drift-sand activity from AD 900 onwards, a period of high population density and large-scale deforestation. Once triggered by human activities, this drift-sand development was probably further intensified several centuries later during the cold and stormier ‘Little Ice Age’ (LIA; AD 1570–1850).

    Subtle variation in shade avoidance responses may have profound consequences for plant competitiveness
    Bongers, Franca J. ; Pierik, Ronald ; Anten, Niels P.R. ; Evers, Jochem B. - \ 2018
    Annals of Botany 121 (2018)5. - ISSN 0305-7364 - p. 863 - 873.
    Background and Aims: Although phenotypic plasticity has been shown to be beneficial for plant competitiveness for light, there is limited knowledge on how variation in these plastic responses plays a role in determining competitiveness. Methods: A combination of detailed plant experiments and functional–structural plant (FSP) modelling was used that captures the complex dynamic feedback between the changing plant phenotype and the within-canopy light environment in time and 3-D space. Leaf angle increase (hyponasty) and changes in petiole elongation rates in response to changes in the ratio between red and far-red light, two important shade avoidance responses in Arabidopsis thaliana growing in dense population stands, were chosen as a case study for plant plasticity. Measuring and implementing these responses into an FSP model allowed simulation of plant phenotype as an emergent property of the underlying growth and response mechanisms. Key Results: Both the experimental and model results showed that substantial differences in competitiveness may arise between genotypes with only marginally different hyponasty or petiole elongation responses, due to the amplification of plant growth differences by small changes in plant phenotype. In addition, this study illustrated that strong competitive responses do not necessarily have to result in a tragedy of the commons; success in competition at the expense of community performance. Conclusions: Together, these findings indicate that selection pressure could probably have played a role in fine-tuning the sensitive shade avoidance responses found in plants. The model approach presented here provides a novel tool to analyse further how natural selection could have acted on the evolution of plastic responses.
    Voorkom dwang en laat je kind gewoon vaccineren
    Verweij, M.F. ; Pierik, R. - \ 2017
    NRC (2017).
    P316 New approaches for IBD management based on text mining of digitalised medical reports and latent class modelling
    Bergey, F. ; Saccenti, E. ; Jonkers, D. ; Heuvel, T. Van Den; Jeuring, S. ; Pierik, M. ; Martins Dos Santos, V. - \ 2017
    Journal of Crohn's and Colitis 11 (2017)suppl_1. - ISSN 1873-9946 - p. S237 - S238.
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