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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Implementation and evaluation of an antimicrobial stewardship programme in companion animal clinics: A stepped-wedge design intervention study
Hopman, Nonke E.M. ; Portengen, Lützen ; Hulscher, Marlies E.J.L. ; Heederik, Dick J.J. ; Verheij, T.J.M. ; Wagenaar, Jaap A. ; Prins, Jan M. ; Bosje, Tjerk ; Schipper, Louska ; Geijlswijk, Ingeborg M. Van; Broens, Els M. - \ 2019
PLoS ONE 14 (2019)11. - ISSN 1932-6203

Background To curb increasing resistance rates, responsible antimicrobial use (AMU) is needed, both in human and veterinary medicine. In human healthcare, antimicrobial stewardship programmes (ASPs) have been implemented worldwide to improve appropriate AMU. No ASPs have been developed for and implemented in companion animal clinics yet. Objectives The objective of the present study was to implement and evaluate the effectiveness of an ASP in 44 Dutch companion animal clinics. The objectives of the ASP were to increase awareness on AMU, to decrease total AMU whenever possible and to shift AMU towards 1st choice antimicrobials, according to Dutch guidelines on veterinary AMU. Methods The study was designed as a prospective, stepped-wedge, intervention study, which was performed from March 2016 until March 2018. The multifaceted intervention was developed using previous qualitative and quantitative research on current prescribing behaviour in Dutch companion animal clinics. The number of Defined Daily Doses for Animal (DDDAs) per clinic (total, 1st, 2nd and 3rd choice AMU) was used to quantify systemic AMU. Monthly AMU data were described using a mixed effect time series model with auto-regression. The effect of the ASP was modelled using a step function and a change in the (linear) time trend. Results A statistically significant decrease of 15% (7%-22%) in total AMU, 15% (5%-24%) in 1st choice AMU and 26% (17%-34%) in 2nd choice AMU was attributed to participation in the ASP, on top of the already ongoing time trends. Use of 3rd choice AMs did not significantly decrease by participation in the ASP. The change in total AMU became more prominent over time, with a 16% (4%-26%) decrease in (linear) time trend per year. Conclusions This study shows that, although AMU in Dutch companion animal clinics was already decreasing and changing, AMU could be further optimised by participation in an antimicrobial stewardship programme.

Herkomst Nutriënten in het landelijk gebied van Schieland
Schipper, Peter ; Gerven, Luuk van; Boekel, Erwin van; Renaud, Leo ; Ros, Gerard - \ 2019
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2969) - 71
De Europese Kaderrichtlijn Water (KRW) schrijft voor dat het oppervlaktewater in 2027 voldoende schoon en ecologisch gezond is. In veel Nederlandse wateren is de nutriëntenbelasting (nog) te hoog om de doelen voor de KRW te halen. Het Hoogheemraadschap van Schieland en de Krimpenerwaard (HHSK) wil ter voorbereiding van besluiten over verbetering van de waterkwaliteit beter inzicht krijgen in de herkomst van de nutriënten in hun wateren. In dit onderzoek is de nutriëntenbelasting van de oppervlaktewateren (en herkomst daarvan) gekwantificeerd voor de periode 2000-2013 voor negen polders in het landelijke gebied van Schieland. Ook zijn effecten van autonoom mestbeleid en enkele landbouwmaatregelen indicatief berekend en zijn de fosfaat- en stikstoftoestand van de toplaag van de landbouwgronden ruimtelijk in kaart gebracht.De nutriëntenbelasting (en herkomst daarvan) in de beschouwde polders verschilt sterk door de grote verschillen in landgebruik, bodemtype en hydrologie. De totale nutriëntenbelasting per hectare is het grootst in polders met veel glastuinbouw, gevolgd door polders met veel akkerbouw. Af- en uitspoeling vanuit landbouwgronden leveren de grootste bijdrage aan de stikstofbelasting (gemiddeld 44%). Dit komt vooral door actuele mestgiften. De rest van de stikstofbelasting komt vooral door diffuse lozingen vanuit glastuinbouw en diffuse bronnen in stedelijk gebied. Af- en uitspoeling leveren ook voor fosfor de grootste bijdrage (gemiddeld 52%). Deze af- en uitspoeling worden niet zozeer door actuele mestgiften bepaald, maar meer door nalevering, historische mestgiften en kwel. De rest van de fosforbelasting komt – net als stikstof – vooral door glastuinbouw en diffuse bronnen in stedelijk gebied. De berekeningen geven aan dat met autonoom mestbeleid en de beschouwde additionele landbouwmaatregelen de nutriëntenbelasting weinig zal afnemen. Wel levert volledige aansluiting van de glastuinbouw een aanzienlijke verlaging van de belasting in de polders met veel glastuinbouw. Dit is al enkele jaren in gang gezet. Vooral in Bleiswijk zal de belasting hierdoor naar verwachting verder afnemen. Trefwoorden: Kaderrichtlijn Water, oppervlaktewater kwaliteit, nutriënten belasting, stikstof, fosfor, herkomst, uitspoeling, afspoeling, bemesting, glastuinbouw, bodemverbetering, kringloopwijzer, fosfaattoestand, stikstof leverend vermogen.
Projecting terrestrial biodiversity intactness with GLOBIO 4
Schipper, Aafke M. ; Hilbers, Jelle P. ; Meijer, Johan R. ; Antão, Laura H. ; Benítez-López, Ana ; Jonge, Melinda M.J. de; Leemans, Luuk H. ; Scheper, Eddy ; Alkemade, Rob ; Doelman, Jonathan C. ; Mylius, Sido ; Stehfest, Elke ; Vuuren, Detlef P. van; Zeist, Willem Jan van; Huijbregts, Mark A.J. - \ 2019
Global Change Biology (2019). - ISSN 1354-1013
anthropocene - biodiversity scenarios - global environmental change - land-use downscaling - mean species abundance

Scenario-based biodiversity modelling is a powerful approach to evaluate how possible future socio-economic developments may affect biodiversity. Here, we evaluated the changes in terrestrial biodiversity intactness, expressed by the mean species abundance (MSA) metric, resulting from three of the shared socio-economic pathways (SSPs) combined with different levels of climate change (according to representative concentration pathways [RCPs]): a future oriented towards sustainability (SSP1xRCP2.6), a future determined by a politically divided world (SSP3xRCP6.0) and a future with continued global dependency on fossil fuels (SSP5xRCP8.5). To this end, we first updated the GLOBIO model, which now runs at a spatial resolution of 10 arc-seconds (~300 m), contains new modules for downscaling land use and for quantifying impacts of hunting in the tropics, and updated modules to quantify impacts of climate change, land use, habitat fragmentation and nitrogen pollution. We then used the updated model to project terrestrial biodiversity intactness from 2015 to 2050 as a function of land use and climate changes corresponding with the selected scenarios. We estimated a global area-weighted mean MSA of 0.56 for 2015. Biodiversity intactness declined in all three scenarios, yet the decline was smaller in the sustainability scenario (−0.02) than the regional rivalry and fossil-fuelled development scenarios (−0.06 and −0.05 respectively). We further found considerable variation in projected biodiversity change among different world regions, with large future losses particularly for sub-Saharan Africa. In some scenario-region combinations, we projected future biodiversity recovery due to reduced demands for agricultural land, yet this recovery was counteracted by increased impacts of other pressures (notably climate change and road disturbance). Effective measures to halt or reverse the decline of terrestrial biodiversity should not only reduce land demand (e.g. by increasing agricultural productivity and dietary changes) but also focus on reducing or mitigating the impacts of other pressures.

Evaluating the ecological realism of plant species distribution models with ecological indicator values
Hellegers, Marjon ; Ozinga, Wim A. ; Hinsberg, Arjen ; Huijbregts, Mark A.J. ; Hennekens, Stephan M. ; Schaminée, Joop H.J. ; Dengler, Jürgen ; Schipper, Aafke M. - \ 2019
Ecography (2019). - ISSN 0906-7590
BioScore - ecological niche model - Ellenberg indicator values - model selection - scale dependency - validation

Species distribution models (SDMs) are routinely applied to assess current as well as future species distributions, for example to assess impacts of future environmental change on biodiversity or to underpin conservation planning. It has been repeatedly emphasized that SDMs should be evaluated based not only on their goodness of fit to the data, but also on the realism of the modeled ecological responses. However, possibilities for the latter are hampered by limited knowledge on the true responses as well as a lack of quantitative evaluation methods. Here we compared modeled niche optima obtained from European-scale SDMs of 1476 terrestrial vascular plant species with empirical ecological indicator values indicating the preferences of plant species for key environmental conditions. For each plant species we first fitted an ensemble SDM including three modeling techniques (GLM, GAM and BRT) and extracted niche optima for climate, soil, land use and nitrogen deposition variables with a large explanatory power for the occurrence of that species. We then compared these SDM-derived niche optima with the ecological indicator values by means of bivariate correlation analysis. We found weak to moderate correlations in the expected direction between the SDM-derived niche optima and ecological indicator values. The strongest correlation occurred between the modeled optima for growing degree days and the ecological indicator values for temperature. Correlations were weaker for SDM-derived niche optima with a more distal relationship to ecological indicator values (notably precipitation and soil moisture). Further, correlations were consistently highest for BRT, followed by GLM and GAM. Our method gives insight into the ecological realism of modeled niche optima and projected core habitats and can be used to improve SDMs by making a more informed selection of environmental variables and modeling techniques.

Suiker in drinkpakjes: Chocomel spant de kroon
Vet, Emely de - \ 2019
The science base of a strategic research agenda - Executive Summary
Bray, A.W. ; Kim, J.H. ; Schrumpf, M. ; Peacock, C. ; Banwart, S. ; Schipper, L. ; Angers, D. ; Chirinda, N. ; Lopes Zinn, Y. ; Albrecht, A. ; Kuikman, P.J. ; Jouquet, P. ; Demenois, J. ; Farrell, M. ; Fontaine, S. ; Soussana, J.F. ; Kuhnert, M. ; Milne, E. ; Taghizadeh-Toosi, A. ; Cerri, C.E.P. ; Corbeels, M. ; Cardinael, R. ; Alcántara Cervantes, V. ; Olesen, J.E. ; Batjes, N.H. ; Heuvelink, G.B.M. ; Maia, S.M.F. ; Keesstra, S.D. ; Claessens, L.F.G. ; Madari, B.E. ; Verchot, L. ; Nie, W. - \ 2019
EU - 16 p.
A summary presenting the challenges for soil carbon sequestration research, hypotheis to be further tested and key research (and innvation) products.
How to measure, report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal
Smith, Pete ; Soussana, Jean Francois ; Angers, Denis ; Schipper, Louis ; Chenu, Claire ; Rasse, Daniel P. ; Batjes, Niels H. ; Egmond, Fenny van; McNeill, Stephen ; Kuhnert, Matthias ; Arias-Navarro, Cristina ; Olesen, Jorgen E. ; Chirinda, Ngonidzashe ; Fornara, Dario ; Wollenberg, Eva ; Álvaro-Fuentes, Jorge ; Sanz-Cobena, Alberto ; Klumpp, Katja - \ 2019
Global Change Biology (2019). - ISSN 1354-1013
measurement - monitoring - MRV - reporting - soil organic carbon - soil organic matter - verification

There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long-term experiments and space-for-time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.

Effect on BMI of a multi-component treatment with E-modules for 3–8-year-old obese children
Hoek, Esther Van; Feskens, Edith J.M. ; Bouwman, Laura I. ; Verburgt, Wilma H. ; Jager, Wilco De; Schipper, Henk S. ; Vrijkotte, Tanja G.M. ; Janse, Arieke J. - \ 2019
Child and Adolescent Obesity 2 (2019)1. - ISSN 2574-254X - p. 79 - 95.
Introduction: Childhood obesity has serious health risks including the development of metabolic syndrome, cardiovascular disease and mortality later in life. The critical growth period from 3 to 7 years provides a window of opportunity for interventions. The goal of this study is to evaluate a one year, multidisciplinary, low-intensity treatment program for young obese children, complemented with web-based modules, called “AanTafel!”, on body composition, cardiometabolic risk profile, quality of life (HRQoL), eating behavior and physical activity.
Methods: In the pre-post-test design all measures were taken at baseline, 4 months, at the end of treatment and 3 years after baseline.
Results: Thirteen boys and 27 girls with median BMI z-score of, respectively, 4.2 and 3.3 aged 3 to 8 started “AanTafel!”. Eighty percent (n = 32) completed treatment. BMI z-score decreased with 0.45 (end of treatment) and sustained after 3 years. At the start, 16.7% of the children had all four components of metabolic syndrome which decreased to 0%. HDL cholesterol significantly increased. Concentrations of the markers IL18, e-selectin, and sICAM significantly decreased indicating a reduction of inflammation.
Conclusion: “AanTafel!” is effective in improving health of obese young children. The reduction of overweight is clinically relevant and sustained after 3 years
Visualizing trypanosomes in a vertebrate host reveals novel swimming behaviours, adaptations and attachment mechanisms
Dóró, Éva ; Jacobs, Sem H. ; Hammond, Ffion R. ; Schipper, Henk ; Pieters, Remco P.M. ; Carrington, Mark ; Wiegertjes, Geert F. ; Forlenza, Maria - \ 2019
eLife 8 (2019). - ISSN 2050-084X
host-pathogen interaction - infectious disease - microbiology - swimming behavior - Trypanosoma carassii - zebrafish

Trypanosomes are important disease agents of humans, livestock and cold-blooded species, including fish. The cellular morphology of trypanosomes is central to their motility, adaptation to the host's environments and pathogenesis. However, visualizing the behaviour of trypanosomes resident in a live vertebrate host has remained unexplored. In this study, we describe an infection model of zebrafish (Danio rerio) with Trypanosoma carassii. By combining high spatio-temporal resolution microscopy with the transparency of live zebrafish, we describe in detail the swimming behaviour of trypanosomes in blood and tissues of a vertebrate host. Besides the conventional tumbling and directional swimming, T. carassii can change direction through a 'whip-like' motion or by swimming backward. Further, the posterior end can act as an anchoring site in vivo. To our knowledge, this is the first report of a vertebrate infection model that allows detailed imaging of trypanosome swimming behaviour in vivo in a natural host environment.

Exploring the functional role of the digital mucus glands and their secretions in tree frog attachment
Langowski, J.K.A. ; Singla, Saranshu ; Nyarko, Alex ; Schipper, H. ; Berg, Frank van den; Kaur, Sukhmanjot ; Astley, Henry C. ; Gussekloo, S.W.S. ; Dhinojwala, Ali ; Leeuwen, J.L. van - \ 2019
- 1 p.
Comparative and functional analysis of the digital mucus glands and secretions of tree frogs
Langowski, Julian K.A. ; Singla, Saranshu ; Nyarko, Alex ; Schipper, Henk ; Berg, Frank T. van den; Kaur, Sukhmanjot ; Astley, Henry C. ; Gussekloo, Sander W.S. ; Dhinojwala, Ali ; Leeuwen, Johan L. Van - \ 2019
Frontiers in Zoology 16 (2019). - ISSN 1742-9994
Cryo-histochemistry - Hyla cinerea - Infrared spectroscopy - Lubrication - Macrogland - Mucosubstance - Sum frequency generation spectroscopy - Synchrotron micro-computer-tomography - Wet adhesion

Background: Mucus and mucus glands are important features of the amphibian cutis. In tree frogs, the mucus glands and their secretions are crucial components of the adhesive digital pads of these animals. Despite a variety of hypothesised functions of these components in tree frog attachment, the functional morphology of the digital mucus glands and the chemistry of the digital mucus are barely known. Here, we use an interdisciplinary comparative approach to analyse these components, and discuss their roles in tree frog attachment.

Results: Using synchrotron micro-computer-tomography, we discovered in the arboreal frog Hyla cinerea that the ventral digital mucus glands differ in their morphology from regular anuran mucus glands and form a subdermal gland cluster. We show the presence of this gland cluster also in several other - not exclusively arboreal - anuran families. Using cryo-histochemistry as well as infrared and sum frequency generation spectroscopy on the mucus of two arboreal (H. cinerea and Osteopilus septentrionalis) and of two terrestrial, non-climbing frog species (Pyxicephalus adspersus and Ceratophrys cranwelli), we find neutral and acidic polysaccharides, and indications for proteinaceous and lipid-like mucus components. The mucus chemistry varies only little between dorsal and ventral digital mucus in H. cinerea, ventral digital and abdominal mucus in H. cinerea and O. septentrionalis, and between the ventral abdominal mucus of all four studied species.

Conclusions: The presence of a digital mucus gland cluster in various anuran families, as well as the absence of differences in the mucus chemistry between arboreal and non-arboreal frog species indicate an adaptation towards generic functional requirements as well as to attachment-related requirements. Overall, this study contributes to the understanding of the role of glands and their secretions in tree frog attachment and in bioadhesion in general, as well as the evolution of anurans.

ICON.NL: coastline observatory to examine coastal dynamics in response to natural forcing and human interventions
Aarninkhof, Stefan ; Schipper, Matthieu De; Luijendijk, Arjen ; Ruessink, Gerben ; Bierkens, Marc ; Wijnberg, Kathelijne ; Roelvink, Dano ; Limpens, J. ; Baptist, M.J. ; Riksen, Michel ; Bouma, Tjeerd ; Vries, Sierd de; Reniers, Ad ; Hulscher, Suzanne ; Wijdeveld, Arjan ; Dongeren, Ap van; Gelder-Maas, Carola van; Lodder, Quirijn ; Spek, Ad van der - \ 2019
- 8 p.
In the light of challenges raised by a changing climate and increasing population pressure in coastal regions, it has become clear that theoretical models and scattered experiments do not provide the data we urgently need to understand coastal conditions and processes. We propose a Dutch coastline observatory named ICON.NL, based at the Delfland Coast with core observations focused on the internationally well-known Sand Engine experiment, as part of an International Coastline Observatories Network (ICON). ICON.NL will cover the physics and ecology from deep water to the dunes. Data will be collected continuously by novel remote sensing and in-situ sensors, coupled to numerical models to yield unsurpassed long-term coastline measurements. The combination of the unique site and ambitious monitoring design enables new avenues in coastal science and a leap in interdisciplinary research.
Potential of novel desert microalgae and cyanobacteria for commercial applications and CO2 sequestration
Schipper, Kira ; Muraikhi, Mariam Al; Alghasal, Ghamza Saed H.S. ; Saadaoui, Imen ; Bounnit, Touria ; Rasheed, Rihab ; Dalgamouni, Tasneem ; Jabri, Hareb Mohammed S.J. Al; Wijffels, René H. ; Barbosa, Maria J. - \ 2019
Journal of Applied Phycology 31 (2019)4. - ISSN 0921-8971 - p. 2231 - 2243.
Carbon capture - CO - Cyanobacteria - Microalgae - Thermotolerance
CO2 fixation by phototrophic microalgae and cyanobacteria is seen as a possible global carbon emissions reducer; however, novel microalgae and cyanobacterial strains with tolerance to elevated temperatures and CO2 concentrations are essential for further development of algae-based carbon capture. Four novel strains isolated from the Arabian Gulf were investigated for their thermotolerance and CO2-tolerance, as well as their carbon capture capability. Two strains, Leptolyngbya sp. and Picochlorum sp., grew well at 40 °C, with productivities of 106.6 ± 10.0 and 87.5 ± 2.1 mg biomass L−1 d−1, respectively. Tetraselmis sp. isolate showed the highest biomass productivity and carbon capture rate of 157.7 ± 10.3 mg biomass L−1 d−1 and 270.8 ± 23.9 mg CO2 L−1 d−1, respectively, both at 30 °C. Under 20% CO2, the biomass productivity increased over 2-fold for both Tetraselmis and Picochlorum isolates, to 333.8 ± 41.1 and 244.7 ± 29.5 mg biomass L−1 d−1. These two isolates also presented significant amounts of lipids, up to 25.6 ± 0.9% and 28.0 ± 2.0% (w/w), as well as presence of EPA and DHA. Picochlorum sp. was found to have a suitable FAME profile for biodiesel production. Both Tetraselmis and Picochlorum isolates showed promising characteristics, making them valuable strains for further investigation towards commercial applications and CO2 capture.
Partial replacement of red and blue by green light increases biomass and yield in tomato
Kaiser, E. ; Weerheim, C. ; Schipper, R. ; Dieleman, J.A. - \ 2019
Scientia Horticulturae 249 (2019). - ISSN 0304-4238 - p. 271 - 279.
Light spectrum; Green light; Light use efficiency; Solanum lycopersicum
Effects of green light on plant growth are relatively understudied, and published results are contradictory. Although per unit leaf area, green light drives photosynthesis less efficiently than does red light, on a whole-plant level green light may increase growth due to changes in vertical light distribution, leaf light acclimation and canopy architecture. As most studies were conducted on small plants with compact stems, positive effects may have remained unnoticed. In a greenhouse experiment, a tomato (Solanum lycopersicum) crop was exposed to 7, 20 or 39% of green light in a background of narrow bandwidth red and blue light, as well as sunlight, for 76 days. The intensity supplied by lamps (171 μmol m−2 s−1) and the red:blue ratio were similar between treatments. Adding green light (+32%) to the spectrum significantly and linearly increased plant biomass and yield (+6.5%). With increasing green light percentage, there were tendencies for linear increases in leaf biomass (P = 0.06), specific leaf area (P = 0.09), stem biomass (P = 0.07), stem length (P = 0.05) and number of internodes (P = 0.05). In the top and middle leaf layers of the canopy, net photosynthesis rate, stomatal conductance and leaf thickness were unaffected by the treatment while in leaves in the middle leaf layer, chlorophyll a:b ratio and carotenoid concentrations increased with the percentage of green light. This study shows that partial replacement of red by green light increases growth of plants in dense canopies and suggests that the combined effects of a light spectrum on plant growth are more than the sum of wavelength effects on photosynthetic efficiency.
Adding Blue to Red Supplemental Light Increases Biomass and Yield of Greenhouse-Grown Tomatoes, but Only to an Optimum
Kaiser, M.E. ; Ouzounis, Theoharis ; Giday, Habtamu ; Schipper, R. ; Heuvelink, E. ; Marcelis, L.F.M. - \ 2019
Frontiers in Plant Science 9 (2019). - ISSN 1664-462X - 11 p.
LED, biomass, blue light, red light, photosynthesis, tomato, greenhouse, yield
Greenhouse crop production in northern countries often relies heavily on supplemental lighting for year-round yield and product quality. Among the different spectra used in supplemental lighting, red is often considered the most efficient, but plants do not develop normally when grown solely under monochromatic red light (“red light syndrome”). Addition of blue light has been shown to aid normal development, and typical lighting spectra in greenhouse production include a mixture of red and blue light. However, it is unclear whether sunlight, as part of the light available to plants in the greenhouse, may be sufficient as a source of blue light. In a greenhouse high-wire tomato (Solanum lycopersicum), we varied the percentage of blue supplemental light (in a red background) as 0, 6, 12, and 24%, while keeping total photosynthetically active radiation constant. Light was supplied as a mixture of overhead (99 μmol m-2 s-1) and intracanopy (48 μmol m-2 s-1) LEDs, together with sunlight. Averaged over the whole experiment (111 days), sunlight comprised 58% of total light incident onto the crop. Total biomass, yield and number of fruits increased with the addition of blue light to an optimum, suggesting that both low (0%) and high (24%) blue light intensities were suboptimal for growth. Stem and internode lengths, as well as leaf area, decreased with increases in blue light percentage. While photosynthetic capacity increased linearly with increases in blue light percentage, photosynthesis in the low blue light treatment (0%) was not low enough to suggest the occurrence of the red light syndrome. Decreased biomass at low (0%) blue light was likely caused by decreased photosynthetic light use efficiency. Conversely, decreased biomass at high (24%) blue light was likely caused by reductions in canopy light interception. We conclude that while it is not strictly necessary to add blue light to greenhouse supplemental red light to obtain a functional crop, adding some (6–12%) blue light is advantageous for growth and yield while adding 24% blue light is suboptimal for growth.
PCLake+ : A process-based ecological model to assess the trophic state of stratified and non-stratified freshwater lakes worldwide
Janssen, Annette B.G. ; Teurlincx, Sven ; Beusen, Arthur H.W. ; Huijbregts, Mark A.J. ; Rost, Jasmijn ; Schipper, Aafke M. ; Seelen, Laura M.S. ; Mooij, Wolf M. ; Janse, Jan H. - \ 2019
Ecological Modelling 396 (2019). - ISSN 0304-3800 - p. 23 - 32.
Deep lake - Food web model - Lake ecology - Limnology - Shallow lake - Thermal stratification

The lake ecosystem model PCLake is a process-based model that was developed to simulate water quality based on ecological interactions in shallow, non-stratifying lakes in the temperate climate zone. Here we present PCLake+, which extends the PCLake model to cover a wide range of freshwater lakes that differ in stratification regime and climate-related processes. To this end, the model was extended with a hypolimnion layer that can be invoked and configured by forcing functions or by simple built-in empirical relationships that impose stratification. Further adjustments to the original PCLake model have been made with respect to the calculation of 1) light irradiation in the water column, 2) evaporation processes and 3) phenology of macrophytes. The simulation output of PCLake+ for different types of lakes complies well with generally accepted limnological knowledge, thus holding promise for future contributions to ecological theory and application to lakes around the globe.

Bronnenanalyse nutriënten stroomgebied Maas
Schipper, Peter ; Renaud, Leo ; Boekel, Erwin van - \ 2019
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2931) - 81
De waterkwaliteit in Nederland – en ook in het Maasstroomgebied (Noord-Brabant en Limburg) – verbetert wel, maar dit gaat niet snel genoeg om de doelen die voor de Europese Kaderrichtlijn Water (KRW) zijn gesteld op tijd te halen. De stoffen stikstof en fosfor (nutriënten) zijn belangrijke factoren voor het bereiken van waterkwaliteitsdoelen. Om effectieve maatregelen te vinden, zijn gedegen gebiedsgerichte analyses nodig om bronnen van de belasting van het (grond)watermilieu door stoffen te kwantificeren. Deze analyses vormen de basis voor de maatregelen die in 2021 worden vastgesteld in de nationale stroomgebiedbeheerplannen (derde generatie SGBP’en) en regionale (water)plannen. De waterschappen en provincies in het Maasstroomgebied hebben behoefte aan een eenduidige analyse van de herkomst van de nutriënten in het oppervlaktewater. In opdracht van het Programmabureau KRW-DHZ Maasregio is onderzoek uitgevoerd naar de nutriëntenbelasting en de bronnen die deze belasting veroorzaken. Uit het onderzoek blijkt dat de totale nutriëntenbelasting van het oppervlaktewater in hoofdzaak worden bepaald door de diffuse uit- en afspoeling vanuit landbouwgronden, effluenten van rioolwaterzuiveringsinstallaties (RWZI’s), toestroming vanuit het buitenland en inlaat vanuit rijkswateren. Voor stikstof heeft actuele bemesting een groot aandeel (72%) in de uit- en afspoeling. Voor fosfor is dit aandeel kleiner (gemiddeld 33%). Binnen debeheersgebieden van de vier waterschappen zijn er per vanggebied grote verschillen tussen de belasting en herkomst. Enerzijds door de regionale verschillen tussen de af- en uitspoeling en het aandeel van de bemesting hierin, anderzijds door de lozingslocaties van RWZI’s, de toestroom vanuit het buitenland, inlaat vanuit rijkswater en de doorvoer van bovenstrooms gelegen waterlichamen, hetgeen sterk verschilt per gebied. Deze resultaten bieden de basis om scenario’s voor maatregelen op te stellen en effecten ervan op de waterkwaliteit te kwantificeren.
Light-dark rhythms during incubation of broiler chicken embryos and their effects on embryonic and post hatch leg bone development
Pol, C.W. van der; Roovert-Reijrink, Inge Van; Maatjens, C.M. ; Gussekloo, S.W.S. ; Kranenbarg, S. ; Wijnen, H.J. ; Pieters, R.P.M. ; Schipper, H. ; Kemp, B. ; Brand, H. van den - \ 2019
PLoS ONE (2019). - ISSN 1932-6203 - 17 p.
There are indications that lighting schedules applied during incubation can affect leg health at hatching and during rearing. The current experiment studied effects of lighting schedule: continuous light (24L), 12 hours of light, followed by 12 hours of darkness (12L:12D), or continuous darkness (24D) throughout incubation of broiler chicken eggs on the development and strength of leg bones, and the role of selected hormones in bone development. In the tibiatarsus and femur, growth and ossification during incubation and size and microstructure at day (D)0, D21, and D35 post hatching were measured. Plasma melatonin, growth hormone, and IGF-I were determined perinatally. Incidence of tibial dyschondroplasia, a leg pathology resulting from poor ossification at the bone’s epiphyseal plates, was determined at slaughter on D35. 24L resulted in lower embryonic ossification at embryonic day (E)13 and E14, and lower femur length, and lower tibiatarsus weight, length, cortical area, second moment of area around the minor axis, and mean cortical thickness at hatching on D0 compared to 12L:12D especially. Results were long term, with lower femur weight and tibiatarsus length, cortical and medullary area of the tibiatarsus, and second moment of area around the minor axis, and a higher incidence of tibial dyschondroplasia for 24L. Growth hormone at D0 was higher for 24D than for 12L:12D, with 24L intermediate, but plasma melatonin and IGF-I did not differ between treatments, and the role of plasma melatonin, IGF-I, and growth hormone in this process was therefore not clear. To conclude, in the current experiment, 24L during incubation of chicken eggs had a detrimental effect on embryonic leg bone development and later life leg bone strength compared to 24D and 12L:12D, while the light-dark rhythm of 12L:12D may have a stimulating effect on leg health.
Tissue specific expression and genomic organization of bitter sesquiterpene lactone biosynthesis in Cichorium intybus L. (Asteraceae)
Bogdanovic, Milica ; Cankar, K. ; Todorovic, Sladana ; Dragicevic, Milan ; Simonovic, Ana ; Houwelingen, A.M.M.L. van; Schijlen, E.G.W.M. ; Schipper, A. ; Gagneul, David ; Hendriks, Theo ; Quillet, Marie-Christine ; Bouwmeester, H.J. ; Bosch, H.J. ; Beekwilder, M.J. - \ 2019
Industrial Crops and Products 129 (2019). - ISSN 0926-6690 - p. 253 - 260.
Chicory (Cichorium intybus L.) produces bitter sesquiterpene lactones (STLs). Some enzymes in the biosynthetic pathway towards these compounds have been characterized. However, the genomic organization and tissue specificity of their biosynthesis is largely unknown. Concentrations of two sesquiterpene lactones and expression of genes involved in the first dedicated biosynthetic step were measured in different chicory tissues. BAC clones containing different genes encoding germacrene A synthase were sequenced, and revealed several tightly linked paralogs. Promoters of genes encoding two germacrene A synthases were fused to GFP and expressed in plants regenerated from transformed chicory hairy root cultures. Highest expression was observed in the epidermis of
leaves and external root tissue. This work opens the possibility to select for chicory germplasm diversified in STL content, and to study their role in chicory in defence and physiology.
Functional interpretation of the force-transmitting structures in a tree frog's toe pad
Langowski, J.K.A. ; Schipper, H. ; Berg, Frank van den; Blij, Anne ; Gussekloo, S.W.S. ; Leeuwen, J.L. van - \ 2018
In: SEB Florence 2018 abstract book 2: Animal biology abstracts. - - p. 152 - 152.
The morphology of tree frogs’ toe pads is adapted towards attachment, allowing these animals to move through their arboreal habitat. Whereas the superficial pad morphology has been studied extensively in previous research, little is known about the internal pad morphology and its functional relevance in attachment. We present the results of a 3-D characterisation and functional analysis of the internal toe pad morphology in the tree frog Hyla cinerea, combining histology, immunohistochemistry, synchrotron micro-computer-tomography, and finite element analysis. The morphology of force-transmitting pad structures, in particular of a collagen layer connecting the ventral epidermis with the medial phalanx, agrees in several aspects with the geometry of a pad model that is topologically optimised towards shear loading. This suggests that tree frogs’ toe pads are primarily adapted towards the transmission of shear loads, as experienced by the frogs while hanging on a vertical substrate. A collagenous septum running from the distal tip of the distal phalanx to the ventral cutis may play a role in peeling and detachment. Furthermore, we show that the adhesive toe pads of tree frogs contain smooth muscle fibre bundles with yet unknown functionality. Overall, our study contributes to the functional understanding of tree frog attachment, hence offering novel perspectives on the ecology, phylogeny, and evolution of anurans, as well as the design of tree-frog-inspired adhesives for technological applications.
Impacts of nitrogen addition on plant species richness and abundance : A global meta-analysis
Midolo, Gabriele ; Alkemade, Rob ; Schipper, Aafke M. ; Benítez-López, Ana ; Perring, Michael P. ; Vries, Wim de - \ 2018
Global Ecology and Biogeography (2018). - ISSN 1466-822X
anthropogenic impacts - biodiversity - eutrophication - global change - GLOBIO - soil acidification - vegetation

Aim: Experimental nitrogen (N) addition (fertilization) studies are commonly used to quantify the impacts of increased N inputs on plant biodiversity. However, given that plant community responses can vary considerably among individual studies, there is a clear need to synthesize and generalize findings with meta-analytical approaches. Our goal was to quantify changes in species richness and abundance in plant communities in response to N addition across different environmental contexts, while controlling for different experimental designs. Location: Global. Time period: Data range: 1985–2016; Publication years: 1990–2018. Major taxa studied: Plants. Methods: We performed a meta-analysis of 115 experiments reported in 85 studies assessing the effects of N addition on terrestrial natural and semi-natural plant communities. We quantified local-scale changes in plant biodiversity in relationship to N addition using four metrics: species richness (SR), individual species abundance (IA), mean species abundance (MSA) and geometric mean abundance (GMA). Results: For all metrics, greater amounts of annual N addition resulted in larger declines in plant diversity. Additionally, MSA decreased more steeply with N that was applied in reduced (NH4 +) rather than oxidized ((NO 3)) form. Loss of SR with increasing amounts of N was found to be larger in warmer sites. Furthermore, greater losses of SR were found in sites with longer experimental durations, smaller plot sizes and lower soil cation exchange capacity. Finally, reductions in the abundance of individual species were larger for N-sensitive plant life-form types (legumes and non-vascular plants). Main conclusions: N enrichment decreases both SR and abundance of plants in N-addition experiments, but the magnitude of the response differs among biodiversity metrics and with the environmental and experimental context. This underlines the importance of integrating multiple dimensions of biodiversity and relevant modifying factors into assessments of biodiversity responses to global environmental change.

A protocol for an intercomparison of biodiversity and ecosystem services models using harmonized land-use and climate scenarios
Kim, Hyejin ; Rosa, Isabel M.D. ; Alkemade, Rob ; Leadley, Paul ; Hurtt, George ; Popp, Alexander ; Vuuren, Detlef P. van; Anthoni, Peter ; Arneth, Almut ; Baisero, Daniele ; Caton, Emma ; Chaplin-Kramer, Rebecca ; Chini, Louise ; Palma, Adriana De; Fulvio, Fulvio Di; Marco, Moreno Di; Espinoza, Felipe ; Ferrier, Simon ; Fujimori, Shinichiro ; Gonzalez, Ricardo E. ; Gueguen, Maya ; Guerra, Carlos ; Harfoot, Mike ; Harwood, Thomas D. ; Hasegawa, Tomoko ; Haverd, Vanessa ; Havlík, Petr ; Hellweg, Stefanie ; Hill, Samantha L.L. ; Hirata, Akiko ; Hoskins, Andrew J. ; Janse, Jan H. ; Jetz, Walter ; Johnson, Justin A. ; Krause, Andreas ; Leclère, David ; Martins, Ines S. ; Matsui, Tetsuya ; Merow, Cory ; Obersteiner, Michael ; Ohashi, Haruka ; Poulter, Benjamin ; Purvis, Andy ; Quesada, Benjamin ; Rondinini, Carlo ; Schipper, Aafke M. ; Sharp, Richard ; Takahashi, Kiyoshi ; Thuiller, Wilfried ; Titeux, Nicolas - \ 2018
Geoscientific Model Development 11 (2018)11. - ISSN 1991-959X - p. 4537 - 4562.

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts of land-use and climate change on biodiversity and ecosystem services (i.e., nature's contributions to people) over the coming decades, compared to the 20th century, using a set of common metrics at multiple scales, and (2) to identify model uncertainties and research gaps through the comparisons of projected biodiversity and ecosystem services across models. BES-SIM uses three scenarios combining specific Shared Socio-economic Pathways (SSPs) and Representative Concentration Pathways (RCPs)-SSP1xRCP2.6, SSP3xRCP6.0, SSP5xRCP8.6-to explore a wide range of land-use change and climate change futures. This paper describes the rationale for scenario selection, the process of harmonizing input data for land use, based on the second phase of the Land Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem services models used, the core simulations carried out, the harmonization of the model output metrics, and the treatment of uncertainty. The results of this collaborative modeling project will support the ongoing global assessment of IPBES, strengthen ties between IPBES and the Intergovernmental Panel on Climate Change (IPCC) scenarios and modeling processes, advise the Convention on Biological Diversity (CBD) on its development of a post-2020 strategic plans and conservation goals, and inform the development of a new generation of nature-centred scenarios.

Force-transmitting structures in the digital pads of the tree frog Hyla cinerea : a functional interpretation
Langowski, Julian K.A. ; Schipper, Henk ; Blij, Anne ; Berg, Frank T. van den; Gussekloo, Sander W.S. ; Leeuwen, Johan L. van - \ 2018
Journal of Anatomy 233 (2018)4. - ISSN 0021-8782 - p. 478 - 495.
attachment organ - bioadhesion - collagen - connective tissue - fibre-matrix-composite - material stiffness - shear load - smooth muscle

The morphology of the digital pads of tree frogs is adapted towards attachment, allowing these animals to attach to various substrates and to explore their arboreal habitat. Previous descriptions and functional interpretations of the pad morphology mostly focussed on the surface of the ventral epidermis, and little is known about the internal pad morphology and its functional relevance in attachment. In this study, we combine histology and synchrotron micro-computer-tomography to obtain a comprehensive 3-D morphological characterisation of the digital pads (in particular of the internal structures involved in the transmission of attachment forces from the ventral pad surface towards the phalanges) of the tree frog Hyla cinerea. A collagenous septum runs from the distal tip of the distal phalanx to the ventral cutis and compartmentalises the subcutaneous pad volume into a distal lymph space and a proximal space, which contains mucus glands opening via long ducts to the ventral pad surface. A collagen layer connects the ventral basement membrane via interphalangeal ligaments with the middle phalanx. The collagen fibres forming this layer curve around the transverse pad-axis and form laterally separated ridges below the gland space. The topological optimisation of a shear-loaded pad model using finite element analysis (FEA) shows that the curved collagen fibres are oriented along the trajectories of the maximum principal stresses, and the optimisation also results in ridge-formation, suggesting that the collagen layer is adapted towards a high stiffness during shear loading. We also show that the collagen layer is strong, with an estimated tensile strength of 2.0–6.5 N. Together with longitudinally skewed tonofibrils in the superficial epidermis, these features support our hypothesis that the digital pads of tree frogs are primarily adapted towards the generation and transmission of friction rather than adhesion forces. Moreover, we generate (based on a simplified FEA model and predictions from analytical models) the hypothesis that dorsodistal pulling on the collagen septum facilitates proximal peeling of the pad and that the septum is an adaptation towards detachment rather than attachment. Lastly, by using immunohistochemistry, we (re-)discovered bundles of smooth muscle fibres in the digital pads of tree frogs. We hypothesise that these fibres allow the control of (i) contact stresses at the pad–substrate interface and peeling, (ii) mucus secretion, (iii) shock-absorbing properties of the pad, and (iv) the macroscopic contact geometry of the ventral pad surface. Further work is needed to conclude on the role of the muscular structures in tree frog attachment. Overall, our study contributes to the functional understanding of tree frog attachment, hence offering novel perspectives on the ecology, phylogeny and evolution of anurans, as well as the design of tree-frog-inspired adhesives for technological applications.

Effectief bodembeheer voor een duurzaam watersysteem stroomgebied de Raam : pilot onderzoeksprogramma Lumbricus, pijler bewuste bodem
Schipper, P.N.M. ; Massop, H. ; Kros, H. ; Eekeren, N. van; Zaanen, M. ; Groenendijk, P. ; Goor, S. van; Ros, G.H. - \ 2018
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2894) - 49
Ecosysteemdiensten in terreinen van Staatsbosbeheer
Hendriks, Kees ; Schuiling, Rini ; Schipper, Peter ; Bouwma, Irene - \ 2018
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2893) - 31
Herkomtst nutriënten Alblasserwaard en Vijfheerenlanden
Boekel, Erwin van; Hendriks, Rob ; Schipper, Peter - \ 2018
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2891) - 61
De regionale waterkwaliteit voldoet op veel plaatsen nog niet aan de doelen die voor de Europese Kaderrichtlijn Water zijn gesteld. Een belangrijke oorzaak hiervan is de hoge nutriëntenbelasting. Het generieke mestbeleid zal naar verwachting niet voor 2027 leiden tot de voor de ecologie gewenste verlaging van nutriëntenbelasting. In de Stroomgebiedsbeheerplannen voor de 3e periode (2022-2027) moet Nederland de definitieve keuzes maken over de doelen van de waterlichamen en in te zetten maatregelen. Met name voor de waterlichamen in de Alblasserwaard (Nederwaard en Overwaard) wil Waterschap Rivierenland bij het definitief vaststellen van de doelen en maatregelen goed rekening kunnen houden met de achtergrondbelasting door nutriëntenrijke kwel, stikstofdepositie, mineralisatie en uitloging van veenbodems. In dit onderzoek is de nutriëntenbelasting voor de periode 2004-2013 gekwantificeerd voor de
Nederwaard, Overwaard en het aangrenzende afwateringsgebied vijfheerenlanden. Met de methodiek ECHO zijn voor het kwantificeren van de uit- en afspoeling van nutriënten de rekenplots van het landelijk modelinstrumentarium STONE regiospecifieker toebedeeld op basis van actuele informatie over het landgebruik, bodemtype en de grondwaterstanden. Per gebied zijn de hoeveelheden inlaatwater en uitgemalen water gekwantificeerd (watervolume en nutriëntenvrachten) op basis van de meetdata en regiospecifieke kennis die het Waterschap voor het onderzoek heeft aangedragen. De belasting met nutriënten vanuit overige bronnen zijn ontleend aan de EmissieRegistratie. Na kwantificering en validatie van de berekende waterbalansen en nutriëntenbalansen is de belasting onderverdeeld naar de bronnen van herkomst. Uit het onderzoek blijkt dat de totale nutriëntenbelasting van het oppervlaktewater voornamelijk wordt bepaald door de uit- en afspoeling uit landbouwgronden (83 à 95%). Voor stikstof levert de actuele bemesting het grootste aandeel (Nederwaard 38%, Overwaard 42%, Vijfheerenlanden 55%), gevolgd door de nalevering vanuit landbouwgronden (respectievelijk 20%, 17% en 8%). Met het modelinstrumentarium zijn de effecten van het 5e Nitraat Actie Programma op de uit- en afspoeling van nutriënten berekend. Evenals de landelijke evaluatie komt hieruit naar voren dat het effect hiervan op de nutriëntenbelasting in de beschouwde gebieden gering is (kleiner dan 5%).
Fysisch-chemische inductie van systemic acquired resistance (SAR): elicitors & stuurlicht
Stevens, L.H. ; Breeuwsma, S.J. ; Rutgers, B. ; Griekspoor, Y. ; Noordam, Marianne ; Vos, C.H. de; Schipper, A. ; Leiss, K.A. - \ 2018
Severe interpersonal violence against children in sport : Associated mental health problems and quality of life in adulthood
Vertommen, Tine ; Kampen, Jarl ; Schipper-van Veldhoven, Nicolette ; Uzieblo, Kasia ; Eede, Filip Van Den - \ 2018
Child Abuse and Neglect 76 (2018). - ISSN 0145-2134 - p. 459 - 468.
Abuse - Child maltreatment - Long-term consequences - Psychological symptoms - Sequelae - Youth sport
In a recent large-scale prevalence study of interpersonal violence (IV) against child athletes in the Netherlands and Belgium we found that 9% of adult respondents who participated in organized sports before the age of 18 had experienced severe psychological violence, 8% severe physical violence, and 6% severe sexual violence in various sport settings. While the general literature has repeatedly shown that exposure to IV during childhood is associated with mental health problems in adulthood and to a lesser extent with reduced quality of life (QOL), these relationships have not been demonstrated in (former) athletes. Thus, the current study aims to assess the association of severe childhood IV in sport and adult wellbeing. Depression, anxiety, and somatization were assessed in the same general population sample (N = 4043) using the Brief Symptom Inventory (BSI-18) and QOL with the World Health Organization Quality of Life questionnaire (WHOQOL-Brèf). The association between severe IV in sport and adult wellbeing was investigated using multiple linear regression while controlling for demographics, recent life events, and relatives’ psychological problems. We found severe sexual, physical, and psychological childhood IV in sport to be associated with more adult psychological distress and reduced QOL. Polyvictimization shows the strongest correlation with poorer wellbeing and QOL. Recent life events, relatives’ psychological problems, marital status, and level of education were significant covariates in the psychological symptoms and QOL assessed. We hope that these new insights prompt sport administrators to implement broad spectrum child protection measures and raise the awareness of mental health professionals about the necessity to also screen for adverse childhood experiences in the sport context.
Alnetea glutinosae
Janssen, J.A.M. ; Hommel, P.W.F.M. - \ 2017
In: Revisie Vegetatie van Nederland / Schaminée, J.H.J., Haveman, R., Hommel, P.W.F.M., Janssen, J.A.M., de Ronde, I., Schipper, P.C., Weeda, E.J., van Dort, K.W., Bal, D., Westerlaan Publisher (Stratiotes 50/51) - ISBN 9789491705106 - p. 161 - 162.
Honckenyo-Elymetea arenarii
Janssen, J.A.M. - \ 2017
In: Revisie Vegetatie van Nederland / Schaminée, J.H.J., Haveman, R., Hommel, P.W.F.M., Janssen, J.A.M., de Ronde, I., Schipper, P.C., Weeda, E.J., van Dort, K.W., Bal, D., Westerlaan Publisher (Stratiotes 50/51) - ISBN 9789491705106 - p. 82 - 86.
Janssen, J.A.M. - \ 2017
In: Revisie Vegetatie van Nederland / Schaminée, J.H.J., Haveman, R., Hommel, P.W.F.M., Janssen, J.A.M., de Ronde, I., Schipper, P.C., Weeda, E.J., van Dort, K.W., Bal, D., Westerlaan Publisher (Stratiotes 50/51) - ISBN 9788481705106 - p. 87 - 88.
Quercetea robori-petraeae
Hommel, P.W.F.M. ; Haveman, Rense ; Janssen, J.A.M. ; Ronde, I. de - \ 2017
In: Revisie Vegetatie van Nederland / Schaminée, J.H.J., Haveman, R., Hommel, P.W.F.M., Janssen, J.A.M., de Ronde, I., Schipper, P.C., Weeda, E.J., van Dort, K.W., Bal, D., Westerlaan Publisher (Stratiotes 50/51) - ISBN 9789491705106 - p. 168 - 176.
Data from sediment sampling campaign, Sand Motor
Huisman, B.J.A. ; Bart, L. ; Schipper, M.A. de; Meirelles, S. ; Sirks, E.E. ; Tonnon, P.K. ; Zwaag, J. van der; Wijsman, J.W.M. - \ 2017
composition - NeMo project - sampling - Sand Motor - sediment
Sediment sampling data from measurement campaign at the Sand Motor
Why plants are little solar panels
Schipper, R. - \ 2017
Wageningen :
biobased economy - plants - miscanthus - bioenergy - fibres - biofuels - breeding methods
What are plants contributing to a biobased society?
Werkdocument Afstemming regionale en landelijke analyses
Klein, Janneke ; Schipper, Peter ; Beekman, Jappe ; Kools, Stefen - \ 2017
Delft : Deltares - 93
Aanpassing Modelinstrumentarium NVK : Tussenrapportage WOT-04-011-034.33
Pouwels, R. ; Schipper, P.N.M. - \ 2017
Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOT-interne notitie 185)
Effect of dietary lipid structure in early life improves metabolic function of adult adipose tissue in mice
Baars, Annemarie ; Schipper, Lidewij ; Mischke, M. ; Klein Hazebroek, Marlou ; Schothorst, E.M. van; Beek, Eline van der; Oosting, Annemarie - \ 2017
Journal of Developmental Origins of Health and Disease 8 (2017)Supplement 1. - ISSN 2040-1744 - p. S52 - S53.
Revisie vegetatie van Nederland
Schaminee, J.H.J. ; Haveman, R. ; Hommel, P.W.F.M. ; Janssen, J.A.M. ; Ronde, I. de; Schipper, P.C. ; Weeda, E.J. ; Dort, K.W. van; Bal, D. - \ 2017
In: Revisie vegetatie van Nederland / Schaminée, J.H.J., Haveman, R., Hommel, P.W.F.M., Janssen, J.A.M., de Ronde, I., Weeda, E.J., van Dort, K.W., Bal, D., Westerlaan Publisher (Stratiotes 50/51 ) - p. 5 - 20.
Best-response potential for Hotelling pure location games
Iimura, Takuya ; Mouche, Pierre van; Watanabe, Takahiro - \ 2017
Economics Letters 160 (2017). - ISSN 0165-1765 - p. 73 - 77.
Best-response potential games - Location games - Pure Nash equilibrium existence - Symmetric games
We revisit two-person one-dimensional pure location games à la Anderson et al. (1992) and show that they admit continuous best-response potential functions (Voorneveld, 2000) if demand is sufficiently elastic (to the extent that the Principle of Minimum Differentiation fails); if demand is not that elastic (or is completely inelastic) they still admit continuous quasi-potential functions (Schipper, 2004). We also show that, even if a continuous best-response potential function exists, a generalized ordinal potential function (Monderer and Shapley, 1996) need not exist.
Kansen voor meer natuurlijkheid in Natura 2000-gebieden
Bijlsma, R.J. ; Jansen, A.J.M. ; Janssen, J.A.M. ; Maas, G.J. ; Pleijte, M. ; Schipper, P.C. ; Wondergem, H.E. - \ 2017
Landschap : tijdschrift voor landschapsecologie en milieukunde 34 (2017)3. - ISSN 0169-6300 - p. 144 - 153.
Aan alle Natura 2000-gebieden zijn instandhoudingsdoelstellingen toegewezen voor soorten en/of habitattypen
van de Vogel- en Habitatrichtlijn. De bezorgdheid groeit dat beheerplannen te weinig rekening
houden met noodzakelijke natuurlijke dynamiek en uitwijkmogelijkheden voor soorten. En hoe staat het
met andere natuurwaarden? Een expliciete landschapsecologische benadering biedt uitkomst en kan goed
aansluiten op het beheerplanproces en richtlijnen bieden voor vergunningverlening en handhaving.
Multiscale scenarios for nature futures
Rosa, Isabel M.D. ; Pereira, Henrique Miguel ; Ferrier, Simon ; Alkemade, J.R.M. ; Acosta, Lilibeth A. ; Resit Akcakaya, H. ; Belder, E. den; Fazel, Asghar M. ; Fujimori, Shinichiro ; Harfoot, Mike ; Harhash, Khaled A. ; Harrison, Paula A. ; Hauck, Jennifer ; Hendriks, Rob J.J. ; Hernández, Gladys ; Jetz, Walter ; Karlsson-Vinkhuyzen, S.I.S.E. ; Kim, Hyejin ; King, Nicholas ; Kok, Marcel ; Kolomytsev, Grygoriy O. ; Lazarova, Tanya ; Leadley, Paul ; Lundquist, Carolyn J. ; García Márquez, Jaime ; Meyer, Carsten ; Navarro, Laetitia M. ; Nesshöver, Carsten ; Ngo, Hien T. ; Ninan, Karachepone N. ; Palomo, Maria G. ; Pereira, Laura ; Peterson, G.D. ; Pichs, Ramon ; Popp, Alexander ; Purvis, Andy ; Ravera, Federica ; Rondinini, Carlo ; Sathyapalan, Jyothis ; Schipper, Aafke ; Seppelt, Ralf ; Settele, Josef ; Sitas, Nadia ; Vuuren, D. van - \ 2017
Nature Ecology & Evolution 1 (2017)10. - ISSN 2397-334X - p. 1416 - 1419.
Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship
with nature to inform decision-making at multiple scales.
Multifunctionele gewasrobot op veengrond
Dalfsen, P. van; Schipper, A.A. - \ 2017
Randwijk : Wageningen University & Research, Bloembollen, Boomkwekerij & Fruit - 14 p.
Effecten van verbetering bodemkwaliteit op waterhuishouding en waterkwaliteit : deelstudies Goede Grond voor een duurzaam watersysteem
Groenendijk, Piet ; Schipper, Peter ; Hendriks, Rob ; Akker, Jan van den; Heinen, Marius - \ 2017
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2811) - 127
bodemkwaliteit - watersystemen - bodemverdichting - maatregelen - uitspoelen - soil quality - water systems - soil compaction - measures - leaching
Het doel van het onderhavige onderzoek is om een antwoord te geven op de vrasag: 'hoe kunnen effecten van maatregelen ter verbetering van de bodemkwaliteit op het watersysteem gekwantificeerd worden, welke meetgegevens zijn daarvoor nodig en hoe kunnen de effecten kwantitatief in beeld gebracht worden zodat ze meegewogen kunnen worden in besluitvormingsprocessen?'
Revisie vegetatie van Nederland
Schaminée, Joop ; Haveman, Rense ; Hommel, Patrick W.F.M. ; Janssen, John A.M. ; Ronde, Iris de; Schipper, Piet C. ; Weeda, Eddy J. ; Dort, Klaas W. van; Bal, Dick - \ 2017
Lichtenvoorde : Westerlaan Publisher - ISBN 9789491705106 - 232
The impact of hunting on tropical mammal and bird populations
Benítez-López, A. ; Alkemade, R. ; Schipper, A.M. ; Ingram, D.J. ; Verweij, P.A. ; Eikelboom, J.A.J. ; Huijbregts, M.A.J. - \ 2017
Science 356 (2017)6334. - ISSN 0036-8075 - p. 180 - 183.

Hunting is a major driver of biodiversity loss, but a systematic large-scale estimate of hunting-induced defaunation is lacking. We synthesized 176 studies to quantify hunting-induced declines of mammal and bird populations across the tropics. Bird and mammal abundances declined by 58% (25 to 76%) and by 83% (72 to 90%) in hunted compared with unhunted areas. Bird and mammal populations were depleted within 7 and 40 kilometers from hunters' access points (roads and settlements). Additionally, hunting pressure was higher in areas with better accessibility to major towns where wild meat could be traded. Mammal population densities were lower outside protected areas, particularly because of commercial hunting. Strategies to sustainably manage wild meat hunting in both protected and unprotected tropical ecosystems are urgently needed to avoid further defaunation.

Space and economics : an introduction to regional economics
Klijs, Jeroen ; Heijman, Wim J.M. ; Peerlings, Jack H.M. ; Rouwendal, Jan ; Schipper, Rob A. - \ 2017
Wageningen : Wageningen Academic Publishers - ISBN 9789086863044 - 360
The subject area Regional Economics has become topical. This means that in economic analyses the production factor 'space' is of increasing importance. This study book aims to integrate space in the area of General Economics in an analytical way. Models and their applications play a major role in the book's approach. The subject of regional economics contains two broad fields. The first is the theory of location, including the basic principles of the economic theory of land use, which has a microeconomic character. The second subject is regional economic development, including spatial equilibrium theory, which is mainly macroeconomic in nature. In the book, both fields will be elaborated in detail. Basic principles of economics are included as background information in order to study the more advanced subjects addressed in the book. Another important feature of the book is its European character which is rather unique. In fact the majority of the applications here are from Europe. Regional statistical data and maps available in Eurostat have been used. The spreadsheet programme Excel is used as a convenient tool for the computation of model results. The description of major applications of Excel is included in the book, which makes it self-contained.
Natuur- en landschapscriteria voor Nationale Parken van Wereldklasse – Naar Nederlandse natuur van internationale allure : Adviesrapport
Vries, Daisy de; Schaminee, J.H.J. ; Schipper, P.C. ; Tersteeg, J.L. - \ 2017
WING Process Consultancy - 73 p.
Om tot de gewenste opschaling en kwaliteitsimpuls voor de Nationale Parken van Wereldklasse te komen zijn afwegingscriteria nodig met betrekking tot de ruimtelijke positie en dimensies van zo’n park. Hiervoor is een studie naar de landschapsecologische en cultuurhistorische kwaliteiten nodig waarop dergelijke afwegingscriteria gefundeerd kunnen zijn. Bovendien wil de programmadirectie Na-tionale Parken weten in hoeverre deze kwaliteiten aansluiten bij internationaal gangbare criteria. De vraag waar dit adviesrapport antwoord op moet geven, luidt dan ook: ‘Wat zijn de natuur- en land-schapscriteria op basis waarvan natuur van internationaal belang in Nederland geïdentificeerd, be-grensd en verder ontwikkeld kunnen worden, in relatie tot Nationale Parken van Wereldklasse?’
Profiling perpetrators of interpersonal violence against children in sport based on a victim survey
Vertommen, Tine ; Kampen, Jarl ; Schipper-van Veldhoven, Nicolette ; Wouters, Kristien ; Uzieblo, Kasia ; Eede, Filip Van Den - \ 2017
Child Abuse and Neglect 63 (2017). - ISSN 0145-2134 - p. 172 - 182.
The current article reports on perpetrator characteristics gathered in the first large-scale prevalence study on interpersonal violence against children in sport in the Netherlands and Belgium. Using retrospective web survey design, 4043 adults answered questions on their experiences in youth sport. The study looks at the number of perpetrators as well as individual descriptive characteristics (sex, age, and role in the sport organization) of perpetrators of psychological, physical and sexual violence as reported retrospectively by victim-respondents. This information was then clustered to provide an overview of the most common perpetrator profiles. Results show that in all types of interpersonal violence in sport, perpetrators are predominantly male peer athletes who frequently operate together in (impromptu) groups. Several differences between the three types of interpersonal violence are highlighted. While incidents of physical violence perpetrated by coaches tend to be less severe compared to those by other perpetrators, acts of sexual violence committed by a coach are significantly more severe. The presented findings shed new light on perpetrators of interpersonal violence in sport, nuancing the predominant belief that the male coach is the main perpetrator while providing nuanced information that can be utilized to improve prevention and child protection measures and other safeguarding initiatives in sport.
Bioscore 2.0 : a species-by-species model to assess anthropogenic impacts on terrestrial biodiversity in Europe
Clement, Jan ; Hendriks, Marjon ; Marco, Moreno Di; Hennekens, Stephan ; Hinsberg, Arjen van; Huijbregts, Mark ; Janssen, Peter ; Kampichler, Christian ; Knegt, Bart de; Knol, Onno ; Mylius, Sido ; Ozinga, Wim ; Pouwels, Rogiere ; Rondinini, Carlo ; Santini, Luca ; Schaminée, Joop ; Schipper, Aafke ; Sierdsema, Henk ; Swaay, Chris van; Tol, Sandy van; Visser, Hans ; Wiertz, Jaap - \ 2016
The Hague : PBL Netherlands Environmental Assessment Agency - 95
Effectief inlaatregiem zoetwatervoorziening Pilot modellering €ureyeopener voor het Hoogheemraadschap Hollands Noorderkwartier
Schipper, Peter ; Veldhuizen, Ab ; Kroes, Joop - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2757) - 35
waterbeheer - zoet water - regionaal beleid - verzilting - beschadigingen door zout - landbouw - noord-holland - polders - water management - fresh water - regional policy - salinization - salt injury - agriculture
In de Nederlandse delta is een uitgekiend waterbeheer van wezenlijk belang voor veiligheid en zoetwatervoorziening. Nu het klimaat verandert en kapitaal intensievere landbouw en andere watergebruikers meer zekerheid willen over de levering van zoet water, is de vraag hoe de zoetwatervoorziening kan worden verbeterd en robuust kan worden gemaakt. In veel gebieden hebben de waterbeheerders nog geen goed overzicht hoe het complexe systeem van zoetwateraanvoer tijdens droge perioden functioneert. Dit komt omdat de zoet-zoutpatronen sterk van plaats tot plaats verschillen, inlaten vaak diffuus van aard zijn en niet worden bemeten en watergebruik voor beregening niet wordt geregistreerd. Zij weten daarom in veel gebieden niet hoe effectief het huidige inlaatregiem is en welke maatregelen geschikt zijn om de zoetwatervoorziening te verbeteren. Het modelconcept de €ureyeopener is ontwikkeld om inzichten te bieden in de effectiviteit van de huidige zoetwateraanvoer en effecten van maatregelen. Het model berekent de wateraanvoerbehoefte, zoutgehalten, gewasschades en de kosten en baten van maatregelen. Voor het Hoogheemraadschap Hollands Noorderkwartier (HHNK) zijn de toepassingsmogelijkheden van dit modelconcept voor HHNK onderzocht door voor de Anna Paulownapolder een €ureyeopener model te maken. In dit gebied spelen voor HHNK nadrukkelijk beleidsvragen voor het voorzieningenniveau, de effecten van de nieuwe sluis bij IJmuiden, slim water management (efficiënter doorspoelen) en de extra zoet watervraag vanuit het Markermeer. Tot vóór de modelstudie had HHNK weinig zicht op de effectiviteit van het doorspoelregiem en de consequenties daarvan voor beregening en mogelijk optredende zoutschade. Het opgezette model geeft transparant inzicht in de uitwerking van het doorspoelregiem en de opbrengstderving van gewassen als het zoutgehalte van het polderwater verandert. In deze rapportage worden de stappen en het resulterende model beschreven. Ten opzichte van eerdere modellen is specifiek aandacht besteed aan de modellering van tulpen en de wijze waarop in het model de waterinlaat kan worden geoptimaliseerd. Met het oog op de samenwerking met Deltares en Bakelse Stroom voor het ontwikkelen van regio-specifieke €ureyeopener modellen hebben zij meegewerkt aan een interne werksessie om een conceptversie van het model te beoordelen en verbeterpunten te identificeren. Ook heeft Deltares bijgedragen aan het formuleren van aanbevelingen.
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