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.

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    The origin and widespread occurrence of Sli-based self-compatibility in potato
    Clot, Corentin R. ; Polzer, Clara ; Prodhomme, Charlotte ; Schuit, Cees ; Engelen, Christel J.M. ; Hutten, Ronald C.B. ; Eck, Herman J. van - \ 2020
    Theoretical and Applied Genetics (2020). - ISSN 0040-5752

    Self-compatible (SC) diploid potatoes allow innovative potato breeding. Therefore, the Sli gene, originally described in S. chacoense, has received much attention. In elite S. tuberosum diploids, spontaneous berry set is occasionally observed. We aimed to map SC from S. tuberosum origin. Two full-sib mapping populations from non-inbred diploids were used. Bulks were composed based on both pollen tube growth and berry set upon selfing. After DNA sequencing of the parents and bulks, we generated k-mer tables. Set algebra and depth filtering were used to identify bulk-specific k-mers. Coupling and repulsion phase k-mers, transmitted from the SC parent, mapped in both populations to the distal end of chromosome 12. Intersection between the k-mers from both populations, in coupling phase with SC, exposed a shared haplotype of approximately 1.5 Mb. Subsequently, we screened read archives of potatoes and wild relatives for k-mers specific to this haplotype. The well-known SC clones US-W4 and RH89-039-16, but surprisingly, also S. chacoense clone M6 were positives. Hence, the S. tuberosum source of SC seems identical to Sli. Furthermore, the candidate region drastically reduced to 333 kb. Haplotype-specific KASP markers were designed and validated on a panel of diploid clones including another renown SC dihaploid G254. Interestingly, k-mers specific to the SC haplotype were common in tetraploid varieties. Pedigree information suggests that the SC haplotype was introduced into tetraploid varieties via the founder “Rough Purple Chili”. We show that Sli is surprisingly widespread and indigenous to the cultivated gene pool of potato.

    Effect of growth conditions on the efficiency of cell disruption of Neochloris oleoabundans
    Safi, C. ; Olivieri, G. ; Engelen-Smit, N. ; Spekking, W. ; Veloo, R. ; Broek, L.A.M. van den; Sijtsma, L. - \ 2020
    Bioresource Technology 300 (2020). - ISSN 0960-8524
    Cell disintegration - Enzymes - High-pressure homogenization - Nitrogen deplete - Nitrogen replete

    The impact of four different growth conditions on the cell disruption efficiency of Neochloris oleoabundans was investigated. A mechanical and biological cell disruption methods were evaluated separately and combined. It has been established that microalgae grown in marine water under nitrogen deprivation were the most resistant against cell disruption methods and released the lowest amount of proteins. The release of lipids, however, followed the “hindered molecule diffusion phenomenon” because it did not follow the same release pattern as proteins. The enzymatic treatment was efficient enough to release the majority of the proteins without combining it with high-pressure homogenization. Regarding energy input, Neochloris oleoabundans grown in marine water under nitrogen deprivation required the highest energy input to release proteins (Ep = 13.76 kWh.kg−1) and to break the cells by high-pressure homogenization (Ex – HPH = 1.14 kWh.kg−1) or by the combination of enzymes and High-pressure homogenization (Ex – ENZ = 2.79 kWh.kg−1).

    Het langetermijngeheugen van de zoet-zoutverdeling
    Louw, Perry de; Oude Essink, Gualbert ; Delsman, Joost ; Baaren, Esther S. van; America, Ilja ; Engelen, van, Joeri - \ 2019
    Stromingen : vakblad voor hydrologen 25 (2019)1. - ISSN 1382-6069 - p. 43 - 60.
    Dit artikel beschrijft de ontwikkeling van de zoetzoutverdeling in het Nederlandse grondwater. Deze verdeling is sterk bepaald door de paleogeografische ontwikkeling gedurende het Holoceen en kent een groot langetermijngeheugen. Er worden twee typen grondwatersystemen beschreven: het West-Nederland systeem, waar autonome verzilting en wellen sleutelbegrippen zijn, en het Zeeuwse systeem, waar drie typen zoetwaterlenzen worden besproken. We laten aan de hand van de FRESHEM-Zeeland-resultaten zien dat airborne-elektromagnetische meettechnieken zeer geschikt zijn voor het in beeld brengen van de zoet-zoutverdeling. Vervolgens wordt ingegaan op het modelleren van de initiële zoet-zoutverdeling, waarbij de combinatie van paleomodellering en gebruik van metingen een geschikte methode lijkt. De initiële zoet-zoutverdeling is een belangrijke modelparameter bij het voorspellen van toekomstige veranderingen van zoete grondwatervoorraden als gevolg van ingrepen, klimaatverandering en zeespiegelstijging.
    Quantification of proteins in seaweeds
    Safi, Carl ; Leeuwen, J.J.A. van; Telleman, Yvette ; Engelen-Smit, N.P.E. ; Broek, L.A.M. van den; Harmsen, P.F.H. - \ 2018
    In: Protocols for Macroalgae Research / Charrier, B., Wichard, T., Reddy, C.R.K., Boca Raton : CRC Press, Taylor & Francis - ISBN 9781498796422 - p. 211 - 224.
    The protein quality and the amino acid composition are key elements for the valorization of seaweeds. Proteins represent a significant part of the primary composition of seaweeds. In this chapter, we describe several protocols for the characterization and quantification of proteins in seaweeds and in the crude extracts. The protocols described are hydrolysis methods, colorimetric methods, amino acid determination, and the determination of the nitrogen to protein conversion factor.
    Letter to the Editor : A response to Huhtanen and Hristov (2018)
    Bovenhuis, Henk ; Engelen, Sabine van; Visker, Marleen H.P.W. - \ 2018
    Journal of Dairy Science 101 (2018)11. - ISSN 0022-0302 - p. 9621 - 9622.
    Pathogenen in dierlijke mest: Riskant?
    Os, J. van; Hoeksma, P. ; Mevius, D.J. ; Overbeek, L.S. van; Engelen, E. van; Lahr, J. - \ 2018
    Tijdschrift Milieu : Vereniging van milieuprofessionals 2018 (2018)5. - p. 47 - 52.
    Door aanscherping van mestgebruiksnormen worden transport en verwerking van dierlijke mest in Nederland steeds noodzakelijker. Dat leidt tot een afname van de Milieubelasting door mineralen in de mest, maar wat betekent het voor de veiligheid? bij de Q-koortsepidemie kon een verband worden gezien met het uitrijden van mest van besmette bedrijven. Bestaat dit risico nog steeds en hoe zit het eigenlijk met andere ziekteverwekkers? Uit een verkennende brainstorm met deskundigen blijkt dat we momenteel niet geconfronteerd worden met grote risico's. Wel zijn er punten naar voren gekomen die de aandacht verdienen om deze risico's beperkt te houden.
    The genetic background of methane emission by dairy cows
    Engelen, Sabine van - \ 2018
    Wageningen University. Promotor(en): H. Bovenhuis, co-promotor(en): M.H.P. Visker. - Wageningen : Wageningen University - ISBN 9789463437325 - 144

    Dairy products are important food sources which contain nutrients that are essential for human development and healthy ageing. Greenhouse gasses are formed during the production of dairy of which methane (CH4) emission by dairy cows is the single largest source. A reduction in CH4 emission could be achieved via selective breeding, though this requires genetic variation in CH4 emission. In order to quantify the genetic variation in CH4 emission, 3 different indicators were used. The first indicator was CH4 emission predicted based on milk fatty acids (FA) which were measured using gas chromatography. Different FA based CH4 prediction equations were used and 12 to 44% of the variation was due to genetic differences between cows. The second indicator was CH4 emission measured with breath sensors. The breath of cows was analysed during milking in automatic milking systems. Genetics explained 3 to 12% of the total variation in this CH4 indicator. The third indicator was CH4 emission predicted based on milk mid-infrared (MIR) spectra. Of this indicator, between 17 and 21% of the total variation could be attributed to genetic factors. These results suggest that there is genetic variation in CH4 emission and selective breeding for lower CH4 emission is possible. The correlations between sensor measured CH4 emission and milk MIR predicted CH4 emission were low, indicating that both indicators explain a different part of the variation in true CH4 emission. The accuracy of the estimated breeding values (EBV) of these CH4 indicators confirms this suggestion. Combining information from sensor measured CH­4 emission with milk MIR predicted CH4 emission increases the accuracy of the EBV compared to using them separately. Correlations of sensor measured CH4 emission and milk MIR predicted CH4 emission with breeding goal traits (production and fertility traits) were low to medium. Genetic correlations between CH4 emission and production traits ranged between -0.61 and 0.65, and genetic correlations between CH4 emission and fertility traits ranged between -0.32 and 0.38. These results suggest that inclusion of CH4 emission in the breeding goal has a minor impact on the breeding goal traits studied. These correlations, however, are estimated on relatively small datasets. Increasing the amount of data by using EBV, correlations between the EBV of the CH4 indicators and the EBV of six breeding goal traits were also low to medium. In conclusion, there is a possibility to use selective breeding to reduce CH4 emission by dairy cows with an anticipated minor impact on other breeding goal traits.

    Genetic background of methane emission by Dutch Holstein Friesian cows measured with infrared sensors in automatic milking systems
    Engelen, S. van; Bovenhuis, H. ; Tol, P.P.J. van der; Visker, M.H.P.W. - \ 2018
    Journal of Dairy Science 101 (2018)3. - ISSN 0022-0302 - p. 2226 - 2234.
    AMS - Dairy cow - Methane emission - Nondispersive infrared sensor
    International environmental agreements have led to the need to reduce methane emission by dairy cows. Reduction could be achieved through selective breeding. The aim of this study was to quantify the genetic variation of methane emission by Dutch Holstein Friesian cows measured using infrared sensors installed in automatic milking systems (AMS). Measurements of CH4 and CO2 on 1508 Dutch Holstein Friesian cows located on 11 commercial dairy farms were available. Phenotypes per AMS visit were the mean of CH4, mean of CO2, mean of CH4 divided by mean of CO2, and their log10-transformations. The repeatabilities of the log10-transformated methane phenotypes were 0.27 for CH4, 0.31 for CO2, and 0.14 for the ratio. The log10-transformated heritabilities of these phenotypes were 0.11 for CH4, 0.12 for CO2, and 0.03 for the ratio. These results indicate that measurements taken using infrared sensors in AMS are repeatable and heritable and, thus, could be used for selection for lower CH4 emission. Furthermore, it is important to account for farm, AMS, day of measurement, time of day, and lactation stage when estimating genetic parameters for methane phenotypes. Selection based on log10-transformated CH4 instead of the ratio would be expected to give a greater reduction of CH4 emission by dairy cows.
    Bioimpuls aardappelveredeling : samenwerking tussen boeren, veredelaars en onderzoekers
    Lammerts Van Bueren, E. ; Engelen, C.J.M. ; Hutten, R.C.B. - \ 2017
    - 1 p.
    Bioimpuls aardappelveredeling, phytophtora-resistentie en moleculaire merkers
    Engelen, C.J.M. ; Hutten, R.C.B. ; Kodde, L.P. ; Vossen, J.H. ; Lammerts Van Bueren, E. - \ 2017
    BIOIMPULS-2 2015-2019: Een rijk palet aan phytophthora resistentiegenen voor bescherming van de aardappel in blad en knol : Groene Veredeling Aardappel
    Lammerts Van Bueren, E. ; Dullaert, H. ; Hutten, R.C.B. ; Engelen, C.J.M. ; Alles, R. ; Boer, A.E.J. de - \ 2017
    Wageningen : Wageningen University & Research - 6 p.
    Over ruimte en het publieke domein : Globalisering en democratie
    Schuurman, A.J. - \ 2017
    In: Van historische informatiekunde naar historische sensatie / Engelen, Theo, Riswick, Tim, Valkhof Pers - ISBN 9789056254827 - p. 117 - 128.
    Reproducibility and relative validity of a food frequency questionnaire to estimate intake of dietary phylloquinone and menaquinones
    Zwakenberg, S.R. ; Engelen, A.I.P. ; Dalmeijer, G.W. ; Booth, S.L. ; Vermeer, C. ; Drijvers, J.J.M.M. ; Ocke, M.C. ; Feskens, E.J.M. ; Schouw, Y.T. van der; Beulens, J.W.J. - \ 2017
    European Journal of Clinical Nutrition 71 (2017). - ISSN 0954-3007 - p. 1423 - 1428.
    Background/Objectives: This study aims to investigate the reproducibility and relative validity of the Dutch food frequency questionnaire (FFQ), to estimate intake of dietary phylloquinone and menaquinones compared with 24-h dietary recalls (24HDRs) and plasma markers of vitamin K status.
    Subjects/Methods: In a cross-sectional study among 63 men and 58 women, the FFQ was completed three times over a 1-year period and the reproducibility was calculated over these measurements. Twelve-monthly 24HDR were collected to estimate relative validity. In addition, the relative validity of the FFQ, compared with plasma phylloquinone and desphospho-uncarboxylated matrix Gla protein (dpucMGP), was assessed cross-sectionally among 507 postmenopausal women.
    Results: Intraclass correlations showed a good reproducibility, with correlations ranging from 0.65 to 0.83. The relative validity for phylloquinone intake compared with 24HDR was lower for women (rs=0.28) than men (rs=0.40). The relative validity, compared with 24HDR, for intake of short-chain menaquinones were ranging between 0.30 and 0.34. Long-chain menaquinones showed good relative validity (rs=0.60–0.69). Plasma phylloquinone concentrations were weakly correlated with phylloquinone intake (rs=0.16 (0.07-0.24). Plasma dpucMGP was negatively but weakly correlated with phylloquinone intake (rs=−0.09 (−0.18; −0.01)) and long-chain menaquinones (rs=−0.13 (−0.21; −0.04)), but not with short-chain menaquinones (rs=−0.04 (−0.13; 0.05)).
    Conclusions: The FFQ is reproducible to rank subjects for phylloquinone and menaquinone intake.The relative validity of our FFQ, compared with 24HDR, to estimate intake of phylloquinone and short-chain menaquinones was low, but the relative validity for long-chain menaquinones was good. The relative validity of our FFQ, compared with plasma phylloquinone and dpucMGP, was relatively low for both phylloquinone and menaquinone intake.
    Energy consumption and water-soluble protein release by cell wall disruption of Nannochloropsis gaditana
    Safi, C. ; Cabas Rodriguez, L. ; Mulder, W.J. ; Engelen-Smit, N. ; Spekking, W. ; Broek, L.A.M. van den; Olivieri, G. ; Sijtsma, L. - \ 2017
    Bioresource Technology 239 (2017). - ISSN 0960-8524 - p. 204 - 210.
    Bead milling - Enzymes - High-pressure homogenization - Pulsed Electric Field - Soluble proteins
    Several cell disruption methods were tested on Nannochloropsis gaditana, to evaluate their efficiency in terms of cell disintegration, energy input and release of soluble proteins. High-pressure homogenization (HPH) and bead milling were the most efficient with >95% cell disintegration, ±50% (w/w) release of total proteins and low energy input (<0.5 kWh.kg−1 biomass). Enzymatic treatment required low energy input (<0.34 kWh.kg−1 biomass), but it only released ±35% protein (w/w). Pulsed Electric Field (PEF) was neither energy-efficient (10.44 kWh.kg−1 biomass) nor successful for protein release (only 10% proteins w/w) and cell disintegration. The release of proteins after applying HPH and bead milling always required less intensive operating conditions for cell disruption. The energy cost per unit of released protein ranged from 0.15–0.25 €.kgProtein −1 in case of HPH, and up to 2–20 €.kgProtein −1 in case of PEF.
    Methaanreductie op de proef gesteld
    Bovenhuis, Henk ; Middelaar, Corina van; Dijkstra, Jan ; Engelen, Sabine van - \ 2017

    Wereldwijd wordt er hard gezocht naar manieren om de uitstoot van het schadelijke broeikasgas methaan te verlagen. Wetenschappelijk onderbouwd en praktisch inzetbaar zijn alle oplossingen nog niet, zo bleek uit vier jaar onderzoek in Wageningen.

    Genetic background of predicted methane based on milk mid-infrared spectra of Dutch Holstein Friesian cows
    Engelen, S. van; Bovenhuis, H. ; Mollenhorst, H. ; Rademaker, J.L.W. ; Visker, M.H.P.W. - \ 2017
    Methane produced by dairy cows is an important greenhouse gas that is partially responsible for global warming and impacts the sustainability of the dairy sector. Breeding for lower methane production could give a long-term and cumulative reduction of methane production, but requires methane phenotypes of many animals obtained at a relative ease. Methane production phenotypes in this study were acquired via two methods: 1) measured from breath samples in automatic milking systems (AMS) via sensors; 2) predicted from milk samples via mid-infrared (MIR) spectroscopy obtained from regular milk production registration. These methods provide efficient and cost-effective methane production phenotypes on large number of cows. The aim of this study is to explore the genetic background of phenotypes acquired via milk MIR and relate these phenotypes to phenotypes acquired via sensors in AMS. Data were collected on 11 commercial dairy farms in the Netherlands with in total 23 individual AMS. Data consisted of 123,374 AMS visits of 1,511 cows with sensor methane production phenotypes. Milk MIR methane prediction models were based on approximately 200 animals with methane measurements in climate respiration chambers and milk MIR. In total, 2,378 MIR methane phenotypes of 1,412 cows were predicted based on routine milk production registration samples of 11 farms. Heritabilities, i.e. the fraction of phenotypic variation due to genetics, of milk MIR methane phenotypes will be calculated to study its potential for breeding for reduced methane production. Furthermore, correlations between milk MIR methane phenotypes and sensor methane phenotypes will be calculated to study the relationship between both types of phenotypes. The results of the analysis of the genetic background of milk MIR methane phenotypes and their correlations with sensor methane phenotypes will be presented.
    Biorefinery of microalgal soluble proteins by sequential processing and membrane filtration
    Safi, C. ; Olivieri, G. ; Pina Campos, Rui ; Engelen-Smit, N. ; Mulder, W.J. ; Broek, L.A.M. van den; Sijtsma, L. - \ 2017
    Bioresource Technology 225 (2017). - ISSN 0960-8524 - p. 151 - 158.
    Biorefinery - Cell disruption - Fractionation - Proteins - Ultrafiltration

    A mild biorefinery process was investigated on the microalga Nannochloropsis gaditana, to obtain an enriched fraction of water soluble proteins free from chlorophyll. After harvesting, a 100 g.L−1 solution of cells was first subjected to cell disruption by either high-pressure homogenization (HPH) or enzymatic treatment (ENZ). HPH resulted in a larger release of proteins (49%) in the aqueous phase compared to the Alcalase incubation (35%). In both cases, an ultrafiltration/diafiltration (UF/DF) was then performed on the supernatant obtained from cell disruption by testing different membrane cut-off (1000 kDa, 500 kDa and 300 kDa). After optimising the process conditions, the combination of ENZ → UF/DF ended in a larger overall yield of water soluble proteins (24.8%) in the permeate compared to the combination of HPH → UF/DF (17.4%). A gel polarization model was implemented to assess the maximum achievable concentration factor during ultrafiltration and the mass transfer coefficient related to the theoretical permeation flux rate.

    Vitamin K intake and all-cause and cause specific mortality
    Zwakenberg, Sabine ; Braver, Nicole den; Engelen, A.I.P. ; Feskens, E.J.M. ; Vermeer, C. ; Boer, J.M.A. ; Verschuren, W.M. ; Schouw, Y.T. van der; Beulens, J.W.J. - \ 2017
    Clinical Nutrition 36 (2017)5. - ISSN 0261-5614 - p. 1294 - 1300.
    Background & aims Vitamin K has been associated with various health outcomes, including non-fatal cardiovascular diseases (CVD) and cancer. However, little is known about the association between vitamin K intake and all-cause and cause specific mortality. This study aims to investigate the association between vitamin K intake and all-cause and cause-specific mortality. Methods This prospective cohort study included 33,289 participants from the EPIC-NL cohort, aged 20–70 years at baseline and recruited between 1993 and 1997. Dietary intake was assessed at baseline with a validated food frequency questionnaire and intakes of phylloquinone, and total, short chain and long chain menaquinones were calculated. Information on vital status and causes of death was obtained through linkage to several registries. The association between the different forms of vitamin K intake and mortality was assessed with Cox proportional hazards, adjusted for risk factors for chronic diseases and nutrient intake. Results During a mean follow-up of 16.8 years, 2863 deaths occurred, including 625 from CVD (256 from coronary heart disease (CHD)), 1346 from cancer and 892 from other causes. After multivariable adjustment, phylloquinone and menaquinones were not associated with all-cause mortality with hazard ratios for the upper vs. the lowest quartile of intake of 1.04 (0.92;1.17) and 0.94 (0.82;1.07) respectively. Neither phylloquinone intake nor menaquinone intake was associated with risk of CVD mortality. Higher intake of long chain menaquinones was borderline significantly associated (ptrend = 0.06) with lower CHD mortality with a HR10μg of 0.86 (0.74;1.00). None of the forms of vitamin K intake were associated with cancer mortality or mortality from other causes. Conclusions Vitamin K intake was not associated with all-cause mortality, cancer mortality and mortality from other causes.
    Sustainable protein production with microalgae : A chain approach
    Sijtsma, L. ; Kootstra, A.M.J. ; Dijk, W. ; Blanco, A. ; Kamermans, P. ; Corre, W.J. ; Mulder, W.J. ; Engelen-Smit, N.P.E. ; Janssens, S.R.M. ; Rijk, P.J. - \ 2016
    Hevige phytophthora-uitbraak 2016 benadrukt noodzaak resistente rassen
    Lammerts Van Bueren, E. ; Hutten, R.C.B. ; Engelen, C.J.M. - \ 2016
    Aardappelwereld 2016 (2016)9. - ISSN 0169-653X - p. 32 - 33.
    phytophthora infestans - aardappelen - biologische landbouw - ziekteresistentie - resistentie van variëteiten - rassen (planten) - plantenveredeling - phytophthora infestans - potatoes - organic farming - disease resistance - varietal resistance - varieties - plant breeding
    De biologische aardappelteelt heeft het in 2016 weer zwaar te verduren gehad met de hevige uitbraak van Phytophtora infestans. Door aanhoudende regenval in juni en juli waren veel telers genoodzaakt om hun percelen met aangetaste aardappelen al vroeg in het seizoen te branden. Gecombineerd met de late pootdatum hebben velen een (te) lage opbrengst van hun vatbare rassen dit jaar. "DIt bevestigt nog maar weer eens de noodzaak van resistente rassen", zo stellen Edith Lammerts van Bueren, Ronald Hutten en Christel Engelen, van het project Bioimpuls waar de deelnemers hard aan nieuwe resistente rassen werken.
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