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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A comparison of global agricultural monitoring systems and current gaps
Fritz, Steffen ; See, Linda ; Bayas, Juan Carlos Laso ; Waldner, François ; Jacques, Damien ; Becker-Reshef, Inbal ; Whitcraft, Alyssa ; Baruth, Bettina ; Bonifacio, Rogerio ; Crutchfield, Jim ; Rembold, Felix ; Rojas, Oscar ; Schucknecht, Anne ; Velde, Marijn Van der; Verdin, James ; Wu, Bingfang ; Yan, Nana ; You, Liangzhi ; Gilliams, Sven ; Mücher, Sander ; Tetrault, Robert ; Moorthy, Inian ; McCallum, Ian - \ 2019
Agricultural Systems 168 (2019). - ISSN 0308-521X - p. 258 - 272.
Crop area - Crop calendars - Crop production - Earth observation - Gaps - Global agricultural monitoring - In-situ data - Spatial resolution - Yield

Global and regional scale agricultural monitoring systems aim to provide up-to-date information regarding food production to different actors and decision makers in support of global and national food security. To help reduce price volatility of the kind experienced between 2007 and 2011, a global system of agricultural monitoring systems is needed to ensure the coordinated flow of information in a timely manner for early warning purposes. A number of systems now exist that fill this role. This paper provides an overview of the eight main global and regional scale agricultural monitoring systems currently in operation and compares them based on the input data and models used, the outputs produced and other characteristics such as the role of the analyst, their interaction with other systems and the geographical scale at which they operate. Despite improvements in access to high resolution satellite imagery over the last decade and the use of numerous remote-sensing based products by the different systems, there are still fundamental gaps. Based on a questionnaire, discussions with the system experts and the literature, we present the main gaps in the data and in the methods. Finally, we propose some recommendations for addressing these gaps through ongoing improvements in remote sensing, harnessing new and innovative data streams and the continued sharing of more and more data.

Optimizing sprayer boom design for bed-grown crops
Holterman, H.J. ; Zande, J.C. van de; Velde, P. van - \ 2018
In: International Advances in Pesticide Application. - Warwick UK : Association of Applied Biologists Warwick Enterprise Park (Aspects of Applied Biology ) - p. 123 - 130.
bed sprayer - optimizing distribution - simulation - model - patternator
For bed-grown crops, ideally the spray is applied evenly to the bed only, while no spray should be applied onto the paths between the beds. Usually these criteria cannot be fulfilled easily. The current study describes the development and use of a model to design adequate set-ups of nozzles on a sprayer boom optimized for bed-grown crops. Spray patterns of various single nozzles at different boom heights have been measured on a patternator. The model combines these spray patterns while varying nozzle types, nozzle spacing and the position and angling of end nozzles. Examples are given for designs using Lechler Varioselect fourfold nozzle bodies to find optimal solutions for beds with widths between 1.1 and 1.5 m and boom heights of 0.2 to 0.6 m above the crop, while being able to apply different dose rates depending on crop canopy height. A large number of potential set-ups are simulated, but only relatively few meet the requirements that can be defined by the user.
Lessons learned from monitoring the stable water isotopic variability in precipitation and streamflow across a snow-dominated subarctic catchment
Lyon, Steve W. ; Ploum, Stefan W. ; Velde, Ype van der; Rocher-Ros, Gerard ; Mörth, Carl Magnus ; Giesler, Reiner - \ 2018
Arctic, Antarctic and Alpine Research 50 (2018)1. - ISSN 1523-0430
Catchment hydrology - freshet - spring flood - stable water isotopes - tracers

This empirical study explores shifts in stable water isotopic composition for a subarctic catchment located in northern Sweden as it transitions from spring freshet to summer low flows. Relative changes in the isotopic composition of streamflow across the main catchment and fifteen nested subcatchments are characterized in relation to the isotopic composition of precipitation. With our sampling campaign, we explore the variability in stream-water isotopic composition that originates from precipitation as the input shifts from snow to rain and as landscape flow pathways change across scales. The isotopic similarity of high-elevation snowpack water and early season rainfall water seen through our sampling scheme made it difficult to truly isolate the impact of seasonal precipitation phase change on stream-water isotopic response. This highlights the need to explicitly consider the complexity of arctic and alpine landscapes when designing sampling strategies to characterize hydrological variability via stable water isotopes. Results show a potential influence of evaporation and source water mixing both spatially (variations with elevation) and temporally (variations from post-freshet to summer flows) on the composition of stream water across Miellajokka. As such, the data collected in this empirical study allow for initial conceptualization of the relative importance of, for example, hydrological connectivity within this mountainous, subarctic landscape.

The hupsel brook catchment : Insights from five decades of lowland observations
Brauer, C.C. ; Velde, Y. van der; Teuling, A.J. ; Uijlenhoet, R. - \ 2018
Vadose Zone Journal 17 (2018)1. - ISSN 1539-1663

The 6.5-km2 Hupsel Brook catchment has been used as an example rural lowland area to understand rainfall–runoff processes, land–atmosphere interactions, and solute transport and to investigate how they are affected by changes in land use and water management. Meteorological and hydrological variables have been measured nearly continuously since 1964, including the 1976 drought and 2010 flood. In addition, more than 2200 water quality samples have been analyzed since the 1980s, with dedicated field campaigns focused on soil physics, evapotranspiration, and rainfall measurement. Novel insights based on these observations include the conclusion that shallow groundwater tables result in a coupled saturated–unsaturated zone and sustain evaporation in dry periods. Partitioning of rainwater between various flow paths is storage driven and therefore catchment wetness determines, together with groundwater–surface water interaction, the response of runoff to rainfall as well as solute transport.

Meta-analysis of genome-wide association studies of aggressive and chronic periodontitis identifies two novel risk loci
Munz, Matthias ; Richter, Gesa M. ; Loos, Bruno G. ; Jepsen, Søren ; Divaris, Kimon ; Offenbacher, Steven ; Teumer, Alexander ; Holtfreter, Birte ; Kocher, Thomas ; Bruckmann, Corinna ; Jockel-Schneider, Yvonne ; Graetz, Christian ; Ahmad, Ilyas ; Staufenbiel, Ingmar ; Velde, Nathalie Van Der; Uitterlinden, André G. ; Groot, Lisette C.P.G.M. De; Wellmann, Jürgen ; Berger, Klaus ; Krone, Bastian ; Hoffmann, Per ; Laudes, Matthias ; Lieb, Wolfgang ; Franke, Andre ; Erdmann, Jeanette ; Dommisch, Henrik ; Schaefer, Arne S. - \ 2018
European Journal of Human Genetics (2018). - ISSN 1018-4813
Periodontitis is one of the most common inflammatory diseases, with a prevalence of 11% worldwide for the severe forms and an estimated heritability of 50%. It is classified into the widespread moderate form chronic periodontitis (CP) and the rare early-onset and severe phenotype aggressive periodontitis (AgP). These different disease manifestations are thought to share risk alleles and predisposing environmental factors. To obtain novel insights into the shared genetic etiology and the underlying molecular mechanisms of both forms, we performed a two step-wise meta-analysis approach using genome-wide association studies of both phenotypes. Genotypes from imputed genome-wide association studies (GWAS) of AgP and CP comprising 5,095 cases and 9,908 controls of North-West European genetic background were included. Two loci were associated with periodontitis at a genome-wide significance level. They located within the pseudogene MTND1P5 on chromosome 8 (rs16870060-G, P = 3.69 × 10−9, OR = 1.36, 95% CI = [1.23–1.51]) and intronic of the long intergenic non-coding RNA LOC107984137 on chromosome 16, downstream of the gene SHISA9 (rs729876-T, P = 9.77 × 10−9, OR = 1.24, 95% CI = [1.15–1.34]). This study identified novel risk loci of periodontitis, adding to the genetic basis of AgP and CP.
Genome-wide association meta-analysis of coronary artery disease and periodontitis reveals a novel shared risk locus
Munz, Matthias ; Richter, Gesa M. ; Loos, Bruno G. ; Jepsen, Søren ; Divaris, Kimon ; Offenbacher, Steven ; Teumer, Alexander ; Holtfreter, Birte ; Kocher, Thomas ; Bruckmann, Corinna ; Jockel-Schneider, Yvonne ; Graetz, Christian ; Munoz, Loreto ; Bhandari, Anita ; Tennstedt, Stephanie ; Staufenbiel, Ingmar ; Velde, Nathalie Van Der; Uitterlinden, André G. ; Groot, Lisette C.P.G.M. De; Wellmann, Jürgen ; Berger, Klaus ; Krone, Bastian ; Hoffmann, Per ; Laudes, Matthias ; Lieb, Wolfgang ; Franke, Andre ; Dommisch, Henrik ; Erdmann, Jeanette ; Schaefer, Arne S. - \ 2018
Scientific Reports 8 (2018)1. - ISSN 2045-2322
Evidence for a shared genetic basis of association between coronary artery disease (CAD) and periodontitis (PD) exists. To explore the joint genetic basis, we performed a GWAS meta-analysis. In the discovery stage, we used a German aggressive periodontitis sample (AgP-Ger; 680 cases vs 3,973 controls) and the CARDIoGRAMplusC4D CAD meta-analysis dataset (60,801 cases vs 123,504 controls). Two SNPs at the known CAD risk loci ADAMTS7 (rs11634042) and VAMP8 (rs1561198) passed the pre-assigned selection criteria (PAgP-Ger < 0.05; PCAD < 5 × 10−8; concordant effect direction) and were replicated in an independent GWAS meta-analysis dataset of PD (4,415 cases vs 5,935 controls). SNP rs1561198 showed significant association (PD[Replication]: P = 0.008 OR = 1.09, 95% CI = [1.02–1.16]; PD [Discovery + Replication]: P = 0.0002, OR = 1.11, 95% CI = [1.05–1.17]). For the associated haplotype block, allele specific cis-effects on VAMP8 expression were reported. Our data adds to the shared genetic basis of CAD and PD and indicate that the observed association of the two disease conditions cannot be solely explained by shared environmental risk factors. We conclude that the molecular pathway shared by CAD and PD involves VAMP8 function, which has a role in membrane vesicular trafficking, and is manipulated by pathogens to corrupt host immune defense.
CTDAS-Lagrange v1.0 : A high-resolution data assimilation system for regional carbon dioxide observations
He, Wei ; Velde, Ivar R. van der; Andrews, Arlyn E. ; Sweeney, Colm ; Miller, John ; Tans, Pieter ; Laan-Luijkx, Ingrid T. van der; Nehrkorn, Thomas ; Mountain, Marikate ; Ju, Weimin ; Peters, Wouter ; Chen, Huilin - \ 2018
Geoscientific Model Development 11 (2018)8. - ISSN 1991-959X - p. 3515 - 3536.

We have implemented a regional carbon dioxide data assimilation system based on the CarbonTracker Data Assimilation Shell (CTDAS) and a high-resolution Lagrangian transport model, the Stochastic Time-Inverted Lagrangian Transport model driven by the Weather Forecast and Research meteorological fields (WRF-STILT). With this system, named CTDAS-Lagrange, we simultaneously optimize terrestrial biosphere fluxes and four parameters that adjust the lateral boundary conditions (BCs) against CO2 observations from the NOAA ESRL North America tall tower and aircraft programmable flask packages (PFPs) sampling program. Least-squares optimization is performed with a time-stepping ensemble Kalman smoother, over a time window of 10 days and assimilating sequentially a time series of observations. Because the WRF-STILT footprints are pre-computed, it is computationally efficient to run the CTDAS-Lagrange system. To estimate the uncertainties in the optimized fluxes from the system, we performed sensitivity tests with various a priori biosphere fluxes (SiBCASA, SiB3, CT2013B) and BCs (optimized mole fraction fields from CT2013B and CTE2014, and an empirical dataset derived from aircraft observations), as well as with a variety of choices on the ways that fluxes are adjusted (additive or multiplicative), covariance length scales, biosphere flux covariances, BC parameter uncertainties, and model-data mismatches. In pseudo-data experiments, we show that in our implementation the additive flux adjustment method is more flexible in optimizing net ecosystem exchange (NEE) than the multiplicative flux adjustment method, and our sensitivity tests with real observations show that the CTDAS-Lagrange system has the ability to correct for the potential biases in the lateral BCs and to resolve large biases in the prior biosphere fluxes. Using real observations, we have derived a range of estimates for the optimized carbon fluxes from a series of sensitivity tests, which places the North American carbon sink for the year 2010 in a range from -0.92 to -1.26PgCyr-1. This is comparable to the TM5-based estimates of CarbonTracker (version CT2016, -0.91±1.10PgCyr-1) and CarbonTracker Europe (version CTE2016, -0.91±0.31PgCyr-1). We conclude that CTDAS-Lagrange can offer a versatile and computationally attractive alternative to these global systems for regional estimates of carbon fluxes, which can take advantage of high-resolution Lagrangian footprints that are increasingly easy to obtain.

Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental scale
Peters, W. ; Velde, I.R. van der; Schaik, Erik van; Miller, John B. ; Ciais, Philippe ; Duarte, Henrique F. ; Laan-Luijkx, I.T. van der; Molen, M.K. van der; Scholze, M. ; Schaefer, Kevin ; Vidale, Pier Luigi ; Verhoef, Anne ; Wårlind, D. ; Zhu, Dan ; Tans, Pieter P. ; Vaughn, Bruce ; White, James W.C. - \ 2018
Nature geoscience 11 (2018). - ISSN 1752-0894 - p. 744 - 748.
Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO2 growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the 13C/12C stable isotope ratio in atmospheric CO2 to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of recent climate variability. We find strong and spatially coherent increases in WUE along with widespread reductions of net carbon uptake over the Northern Hemisphere during severe droughts that affected Europe, Russia and the United States in 2001–2011. The impact of those droughts on WUE and carbon uptake by vegetation is substantially larger than simulated by the land-surface schemes of six state-of-the-art climate models. This suggests that drought-induced carbon–climate feedbacks may be too small in these models and improvements to their vegetation dynamics using stable isotope observations can help to improve their drought response.
Bodemvocht uit satellietdata: wat kan de Nederlandse waterbeheerder ermee?
Velde, R. van der; Benninga, H.J. ; Pezij, M. ; Augustijn, D. ; Carranza, C. ; Ploeg, M. van der; Hendriks, D. - \ 2018
H2O online 2018 (2018)21 augustus. - 11
Het onderzoeksproject ‘Optimizing Water Availability with Sentinel-1 Satellites’ heeft als doel te onderzoeken hoe satellietdata gebruikt kan worden in het Nederlandse waterbeheer. Het onderzoek laat zien dat de satelliet Sentinel-1 buiten het groeiseizoen om al een vrij goed beeld geeft van het bodemvochtgehalte. Hiermee kan bijvoorbeeld de berijdbaarheid van landbouwpercelen in kaart gebracht kan worden. Ook is met Deltares en HKV een data-assimilatietool ontwikkeld die ingezet kan worden om simulaties met het Landelijk Hydrologisch Model te verbeteren.
Driftreductie Munckhof MAS 3 rijen boomgaardspuit : effect van VARIMAS variabele luchtondersteuning en Randrijen instelling
Stallinga, H. ; Velde, P. van; Michielsen, J.M.G.P. ; Wenneker, M. ; Zande, J.C. van de - \ 2018
Wageningen : Stichting Wageningen Research, Busines Unit Agrosystems (Rapport WPR 759) - 37
Results of spray drift experiments are presented of the Munckhof MAS 3-row orchard sprayer in comparison with a reference spray technique for fruit crop spraying in The Netherlands. The Munckhof MAS 3-row orchard sprayer was equipped with a 90% drift reducing nozzle (Albuz TVI8001; 7 bar spray pressure), low level of air assistance (400 rpm PTO) and the VARIMAS variable air system and an Edge-Row setting. During the spray drift experiments the downwind outside 24 m of an apple orchard was sprayed at the full leaf stage (BBCH 91/92) using the fluorescent tracer Acid Yellow 250. Spray drift deposition was collected downwind of the sprayed orchard on a mowed grass area up to 25 m distance from the last tree row. Airborne spray drift was measured at 7.5 m distance from the last tree row on a pole at which two lines with collectors were attached at 1 m spacing up to 10 m height. The spray drift experiments showed that spraying an apple orchard at the full leaf stage
(BBCH 91/92) with a Munckhof MAS 3-row orchard sprayer equipped with 90% drift reducing Albuz TVI8001 nozzles (7 bar), low level of air assistance (400 rpm PTO) and VARIMAS-system (last tree row sprayed from both sides) spray drift reduction at 4.5-5.5 m distance from the last tree row was 98.9% in comparison with the reference spray application. Using the VARIMAS-system with EdgeRow-setting the spray drift reduction was 99.5%. Airborne spray drift
reduction at 7.5 m distance from the last tree row averaged over 10 m height was for the Munckhof MAS 3-row orchard sprayer equipped with 90% drift reducing Albuz TVI8001 nozzles (7 bar), low level of air assistance (400 rpm PTO) and VARIMAS-system 98.8% and for the VARIMAS-system with EdgeRow
-setting 98.6%.
Regional soil moisture monitoring network in the Raam catchment in the Netherlands - 2016-04 / 2017-04 (corrected)
Benninga, H.F. ; Carranza, C.D. ; Pezij, M. ; Ploeg, M.J. van der; Augustijn, D.C.M. ; Velde, R. van der - \ 2018
agriculture - hydrology - soil moisture - soil temperature - unsaturated zone - water management
When do Indians feel hot? : Internet searches indicate seasonality suppresses adaptation to heat
Singh, T. ; Siderius, C. ; Velde, Y. van der - \ 2018
Environmental Research Letters 13 (2018)5. - ISSN 1748-9326 - 10 p.
In a warming world an increasing number of people are being exposed to heat, making a comfortable thermal environment an important need. This study explores the potential of using Regional Internet Search Frequencies (RISF) for air conditioning devices as an indicator for thermal discomfort (i.e. dissatisfaction with the thermal environment) with the aim to quantify the adaptation potential of individuals living across different climate zones and at the high end of the temperature range, in India, where access to health data is limited. We related RISF for the years 2011–2015 to daily daytime outdoor temperature in 17 states and determined at which temperature RISF for air conditioning starts to peak, i.e. crosses a 'heat threshold', in each state. Using the spatial variation in heat thresholds, we explored whether people continuously exposed to higher temperatures show a lower response to heat extremes through adaptation (e.g. physiological, behavioural or psychological). State-level heat thresholds ranged from 25.9 °C in Madhya Pradesh to 31.0 °C in Orissa. Local adaptation was found to occur at state level: the higher the average temperature in a state, the higher the heat threshold; and the higher the intra-annual temperature range (warmest minus coldest month) the lower the heat threshold. These results indicate there is potential within India to adapt to warmer temperatures, but that a large intra-annual temperature variability attenuates this potential to adapt to extreme heat. This winter 'reset' mechanism should be taken into account when assessing the impact of global warming, with changes in minimum temperatures being an important factor in addition to the change in maximum temperatures itself. Our findings contribute to a better understanding of local heat thresholds and people's adaptive capacity, which can support the design of local thermal comfort standards and early heat warning systems.
Diet quality in childhood : the Generation R Study
Velde, Laura A. van der; Nguyen, Anh N. ; Schoufour, Josje D. ; Geelen, Anouk ; Jaddoe, Vincent W.V. ; Franco, Oscar H. ; Voortman, Trudy - \ 2018
European Journal of Nutrition (2018). - ISSN 1436-6207 - p. 1 - 11.
Determinants - Diet quality - Dietary patterns - Epidemiology - Tracking - Validation
Purpose: We aimed to evaluate diet quality of 8-year-old children in the Netherlands, to identify sociodemographic and lifestyle correlates of child diet quality, and to examine tracking of diet quality from early to mid-childhood. Methods: For 4733 children participating in a population-based cohort, we assessed dietary intake using a validated food-frequency questionnaire at a median age of 8.1 years (interquartile range 8.0–8.2) (2011–2014). Based on dietary guidelines, we developed and validated a food-based diet quality score for children consisting of ten components (score 0–10): sufficient intake of vegetables; fruit; whole grains; fish; legumes; nuts; dairy; oils and soft fats; and low intake of sugar-containing-beverages; and high-fat and processed meat. Results: We observed a mean (± SD) diet quality score of 4.5 (± 1.2) out of a maximum of 10. On average, intake of legumes, nuts, and oils or soft fats was below recommendations, whereas intake of sugar-containing beverages and high-fat or processed meat was higher than recommended. The main factors associated with higher diet quality were higher maternal educational level (β = 0.29, 95% CI 0.21, 0.37 versus low education), higher household income (β = 0.15, 95% CI 0.05, 0.25 versus low income), no maternal smoking (β = 0.13, 95% CI 0.02, 0.25 versus current smoking), and less screen time (β = 0.31, 95% CI 0.24, 0.38)—all independent of each other. For children with available dietary data at age 1 year (n = 2608), we observed only weak tracking of diet quality from early to mid-childhood (Pearson’s r = 0.19, k = 0.11 for extreme quartiles). Conclusion: Overall diet quality of 8-year-old children did not conform to dietary guidelines, especially for children having more screen time, children of lower educated or smoking mothers, or from lower-income households.
Corrigendum to: A genome-wide association study identifies nucleotide variants at SIGLEC5 and DEFA1A3 as risk loci for periodontitis
Munz, Matthias ; Willenborg, Christina ; Richter, Gesa M. ; Jockel-Schneider, Yvonne ; Graetz, Christian ; Staufenbiel, Ingmar ; Wellmann, Jürgen ; Berger, Klaus ; Krone, Bastian ; Hoffmann, Per ; Velde, Nathalie Van Der; Uitterlinden, André G. ; Groot, C.P.G.M. De; Sawalha, Amr H. ; Direskeneli, Haner ; Saruhan-Direskeneli, Güher ; Guzeldemir-Akcakanat, Esra ; Keceli, Huseyin Gencay ; Laudes, Matthias ; Noack, Barbara ; Teumer, Alexander ; Holtfreter, Birte ; Kocher, Thomas ; Eickholz, Peter ; Meyle, Jörg ; Doerfer, Christof ; Bruckmann, Corinna ; Lieb, Wolfgang ; Franke, Andre ; Schreiber, Stefan ; Nohutcu, Rahime M. ; Erdmann, Jeanette ; Loos, Bruno G. ; Jepsen, Soeren ; Dommisch, Henrik ; Schaefer, Arne S. - \ 2018
Human Molecular Genetics 27 (2018)5. - ISSN 0964-6906 - p. 941 - 942.
Serum folate and vitamin B12 are associated with body composition in elderly: The B-PROOF study
Oliai Araghi, S. ; Braun, K.V.E. ; Velde, Nathalie van der; Dijk, S. van; Schoor, Natasja M. van; Zillikens, M.C. ; Groot, C.P.G.M. de; Uitterlinden, André G. ; Stricker, B.H. ; Voortman, Trudy ; Kiefte-de Jong, J.C. - \ 2018
Genome-wide association study in 79,366 European-ancestry individuals informs the genetic architecture of 25-hydroxyvitamin D levels
Jiang, Xia ; O'Reilly, Paul F. ; Aschard, Hugues ; Hsu, Yi Hsiang ; Richards, J.B. ; Dupuis, Josée ; Ingelsson, Erik ; Karasik, David ; Pilz, Stefan ; Berry, Diane ; Kestenbaum, Bryan ; Zheng, Jusheng ; Luan, Jianan ; Sofianopoulou, Eleni ; Streeten, Elizabeth A. ; Albanes, Demetrius ; Lutsey, Pamela L. ; Yao, Lu ; Tang, Weihong ; Econs, Michael J. ; Wallaschofski, Henri ; Völzke, Henry ; Zhou, Ang ; Power, Chris ; McCarthy, Mark I. ; Michos, Erin D. ; Boerwinkle, Eric ; Weinstein, Stephanie J. ; Freedman, Neal D. ; Huang, Wen Yi ; Schoor, Natasja M. van; Velde, Nathalie van der; Groot, Lisette C.P.G.M. de; Enneman, Anke ; Cupples, L.A. ; Booth, Sarah L. ; Vasan, Ramachandran S. ; Liu, Ching Ti ; Zhou, Yanhua ; Ripatti, Samuli ; Ohlsson, Claes ; Vandenput, Liesbeth ; Lorentzon, Mattias ; Eriksson, Johan G. ; Shea, M.K. ; Houston, Denise K. ; Kritchevsky, Stephen B. ; Liu, Yongmei ; Lohman, Kurt K. ; Ferrucci, Luigi ; Peacock, Munro ; Gieger, Christian ; Beekman, Marian ; Slagboom, Eline ; Deelen, Joris ; Deelen, Joris ; Heemst, Diana van; Kleber, Marcus E. ; März, Winfried ; Boer, Ian H. De; Wood, Alexis C. ; Rotter, Jerome I. ; Rich, Stephen S. ; Robinson-Cohen, Cassianne ; Heijer, Martin Den; Jarvelin, Marjo Riitta ; Jarvelin, Marjo Riitta ; Cavadino, Alana ; Cavadino, Alana ; Joshi, Peter K. ; Wilson, James F. ; Hayward, Caroline ; Lind, Lars ; Michaëlsson, Karl ; Trompet, Stella ; Zillikens, M.C. ; Uitterlinden, Andre G. ; Rivadeneira, Fernando - \ 2018
Nature Communications 9 (2018)1. - ISSN 2041-1723
Vitamin D is a steroid hormone precursor that is associated with a range of human traits and diseases. Previous GWAS of serum 25-hydroxyvitamin D concentrations have identified four genome-wide significant loci (GC, NADSYN1/DHCR7, CYP2R1, CYP24A1). In this study, we expand the previous SUNLIGHT Consortium GWAS discovery sample size from 16,125 to 79,366 (all European descent). This larger GWAS yields two additional loci harboring genome-wide significant variants (P = 4.7×10 -9 at rs8018720 in SEC23A, and P = 1.9×10 -14 at rs10745742 in AMDHD1). The overall estimate of heritability of 25-hydroxyvitamin D serum concentrations attributable to GWAS common SNPs is 7.5%, with statistically significant loci explaining 38% of this total. Further investigation identifies signal enrichment in immune and hematopoietic tissues, and clustering with autoimmune diseases in cell-type-specific analysis. Larger studies are required to identify additional common SNPs, and to explore the role of rare or structural variants and gene-gene interactions in the heritability of circulating 25-hydroxyvitamin D levels.
The CarbonTracker Data Assimilation System for CO2 and δ13C (CTDAS-C13 v1.0) : Retrieving information on land-atmosphere exchange processes
Velde, Ivar R. Van Der; Miller, John B. ; Molen, Michiel K. Van Der; Tans, Pieter P. ; Vaughn, Bruce H. ; White, James W.C. ; Schaefer, Kevin ; Peters, Wouter - \ 2018
Geoscientific Model Development 11 (2018)1. - ISSN 1991-959X - p. 283 - 304.
To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS). The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO2) along with observed ratios of its stable isotopologues 13CO2/12CO2 (δ13C). The latter is in particular a valuable tracer to untangle CO2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of 13CO2 and 12CO2 molecules removed from the atmosphere by plants is dependent on moisture conditions. The dual-species CTDAS system varies the net exchange fluxes of both 13CO2 and CO2 in ocean and terrestrial biosphere models to create an ensemble of 13CO2 and CO2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated 13CO2 and CO2 mole fractions (and thus δ13C) our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions. With this system, we are able to estimate changes in terrestrial δ13C exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal conductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO2 and δ13C constraints as done in this work. The additional constraints on surface CO2 exchange from δ13C observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO2 variations. The prototype presented here can be of great benefit not only to study the global carbon balance but also to potentially function as a data-driven diagnostic to assess multiple leaf-level exchange parameterizations in carbon-climate models that influence the CO2, water, isotope, and energy balance.
The Raam regional soil moisture monitoring network in the Netherlands
Benninga, H.F. ; Carranza, C.D.U. ; Pezij, M. ; Santen, Pim van; Ploeg, M.J. van der; Augustijn, Denie C.M. ; Velde, Rogier van der - \ 2018
Earth System Science Data 10 (2018). - ISSN 1866-3508 - p. 61 - 79.
We have established a soil moisture profile monitoring network in the Raam region in the Netherlands. This region faces water shortages during summers and excess of water during winters and after extreme precipitation events. Water management can benefit from reliable information on the soil water availability and water storing capacity in the unsaturated zone. In situ measurements provide a direct source of information on which water managers can base their decisions. Moreover, these measurements are commonly used as a reference for the calibration and validation of soil moisture content products derived from earth observations or obtained by model simulations. Distributed over the Raam region, we have equipped 14 agricultural fields and 1 natural grass field with soil moisture and soil temperature monitoring instrumentation, consisting of Decagon 5TM sensors installed at depths of 5, 10, 20, 40 and 80 cm. In total, 12 stations are located within the Raam catchment (catchment area of 223 km2), and 5 of these stations are located within the closed sub-catchment Hooge Raam (catchment area of 41 km2). Soil-specific calibration functions that have been developed for the 5TM sensors under laboratory conditions lead to an accuracy of 0.02 m3 m−3. The first set of measurements has been retrieved for the period 5 April 2016–4 April 2017. In this paper, we describe the Raam monitoring network and instrumentation, the soil-specific calibration of the sensors, the first year of measurements, and additional measurements (soil temperature, phreatic groundwater levels and meteorological data) and information (elevation, soil physical characteristics, land cover and a geohydrological model) available for performing scientific research. The data are available at
Innovation For Society: Towards a Typology of Developing Innovations by Social Entrepreneurs
Lubberink, R.J.B. ; Blok, V. ; Ophem, J.A.C. van; Velde, Gerben van der; Omta, S.W.F. - \ 2018
The Journal of Social Entrepreneurship 9 (2018)1. - ISSN 1942-0676 - p. 52 - 78.
Social entrepreneurs develop important innovative solutions for complex societal challenges. This exploratory article provides a typology of different approaches by which social entrepreneurs develop such innovations. This typology is based on their engagement in anticipation, reflexivity, stakeholder inclusion and deliberation, responsiveness and knowledge management, during the development of their innovation. Following from quantitative analyses of data from self-assessment questionnaires and subsequent contextualization, the findings reveal four distinctive ways to successfully develop innovative solutions for societal problems. This article therefore contributes to our understanding of the innovation process by which social entrepreneurs develop social innovations.
An improved vitrification protocol for equine immature oocytes, resulting in a first live foal
Ortiz-Escribano, N. ; Bogado Pascottini, O. ; Woelders, H. ; Vandenberghe, L. ; Schauwer, C. De; Govaere, J. ; Abbeel, E. Van den; Vullers, T. ; Ververs, C. ; Roels, K. ; De Velde, M. Van; Soom, A. van; Smits, K. - \ 2018
Equine Veterinary Journal 50 (2018)3. - ISSN 0425-1644 - p. 391 - 397.
Cumulus cells - Horse - Oocytes - Vitrification
Background: The success rate for vitrification of immature equine oocytes is low. Although vitrified-warmed oocytes are able to mature, further embryonic development appears to be compromised. Objectives: The aim of this study was to compare two vitrification protocols, and to examine the effect of the number of layers of cumulus cells surrounding the oocyte during vitrification of immature equine oocytes. Study design: Experimental in vitro and in vivo trials. Methods: Immature equine oocytes were vitrified after a short exposure to high concentrations of cryoprotective agents (CPAs), or a long exposure to lower concentrations of CPAs. In Experiment 1, the maturation of oocytes surrounded by multiple layers of cumulus cells (CC oocytes) and oocytes surrounded by only corona radiata (CR oocytes) was investigated. In Experiment 2, spindle configuration was determined for CR oocytes vitrified using the two vitrification protocols. In Experiment 3, further embryonic development was studied after fertilisation and culture. Embryo transfer was performed in a standard manner. Results: Similar nuclear maturation rates were observed for CR oocytes vitrified using the long exposure and nonvitrified controls. Furthermore, a lower maturation rate was obtained for CC oocytes vitrified with the short exposure compared to control CR oocytes (P = 0.001). Both vitrification protocols resulted in significantly higher rates of aberrant spindle configuration than the control groups (P<0.05). Blastocyst development only occurred in CR oocytes vitrified using the short vitrification protocol, and even though blastocyst rates were significantly lower than in the control group (P<0.001), transfer of five embryos resulted in one healthy foal. Main limitations: The relatively low number of equine oocytes and embryo transfer procedures performed. Conclusions: For vitrification of immature equine oocytes, the use of 1) CR oocytes, 2) a high concentration of CPAs, and 3) a short exposure time may be key factors for maintaining developmental competence.
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