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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    de Toekomst van Natuur en Energie in Nederland
    Hattum, Tim van; Rooij, Bertram de - \ 2020

    de Toekomst van Natuur en Energie in Nederland n.a.v. Kaart NL2120, interview van Marlies Dekkers met Tim van Hattum en Bertram de Rooij

    Identification and in silico bioinformatics analysis of PR10 proteins in cashew nut
    Bastiaan-Net, Shanna ; Pina-Pérez, Maria C. ; Dekkers, Bas J.W. ; Westphal, Adrie H. ; America, Antoine H.P. ; Ariëns, Renata M.C. ; Jong, Nicolette W. de; Wichers, Harry J. ; Mes, Jurriaan J. - \ 2020
    Protein Science 29 (2020)7. - ISSN 0961-8368 - p. 1581 - 1595.
    Anacardium occidentale - Bet v 1-like - cashew nut - in silico allergenicity analysis - oral allergy syndrome (OAS) - PR10 - RNA-seq

    Proteins from cashew nut can elicit mild to severe allergic reactions. Three allergenic proteins have already been identified, and it is expected that additional allergens are present in cashew nut. pathogenesis-related protein 10 (PR10) allergens from pollen have been found to elicit similar allergic reactions as those from nuts and seeds. Therefore, we investigated the presence of PR10 genes in cashew nut. Using RNA-seq analysis, we were able to identify several PR10-like transcripts in cashew nut and clone six putative PR10 genes. In addition, PR10 protein expression in raw cashew nuts was confirmed by immunoblotting and liquid chromatography–mass spectrometry (LC–MS/MS) analyses. An in silico allergenicity assessment suggested that all identified cashew PR10 proteins are potentially allergenic and may represent three different isoallergens.

    Process history of calcium caseinate affects fibre formation
    Wang, Zhaojun ; Dekkers, Birgit L. ; Goot, Atze Jan van der - \ 2020
    Journal of Food Engineering 275 (2020). - ISSN 0260-8774
    Calcium caseinate - Drying - Fibre - Mechanical properties - Roller - Spray drying - Thermal history

    In this study, we compared the physical properties and structuring potential of spray-dried calcium caseinate (Scaca) and roller-dried calcium caseinate (Rcaca). Scaca formed more pronounced fibrous materials upon shearing compared with Rcaca. The rheological measurements revealed that the Scaca dispersion exhibited more solid-like behaviour. Besides, the particle size in excess water was larger for Rcaca (2–300 μm), while Scaca mainly contained small caseinate aggregates (<800 nm). Finally, Rcaca was less susceptible to enzymatic crosslinking with transglutaminase. The different physical properties and structuring potentials were explained by the intensive thermal treatment during roller drying for Rcaca. The application of a similar thermal process to Scaca resulted in similar properties as Rcaca. We concluded that the process history of calcium caseinate has major consequences for its fibre formation potential.

    GSE's 50th anniversary : Where do we go from now?
    Boichard, Didier ; Dekkers, Jack ; Hayes, Helene ; Werf, Julius van der; Bovenhuis, Henk ; Calus, Mario ; Groenen, Martien - \ 2019
    Genetics, Selection, Evolution 51 (2019). - ISSN 0999-193X
    Toasting as a tool to improve the functional properties of fababean protein concentrate
    Bühler, J. ; Dekkers, B.L. ; Bruins, M.E. ; Goot, A.J. van der - \ 2019
    Wageningen University & Research - 1 p.
    Toasting as a tool - protein concentration
    Protein Oxidation and in Vitro Gastric Digestion of Processed Soy-Based Matrices
    Duque-Estrada, Patrícia ; Berton-Carabin, Claire C. ; Nieuwkoop, Matthijs ; Dekkers, Birgit L. ; Janssen, Anja E.M. ; Goot, Atze Jan Van Der - \ 2019
    Journal of Agricultural and Food Chemistry 64 (2019)34. - ISSN 0021-8561 - p. 9591 - 9600.
    gastric digestion - meat analogues - processing - protein oxidation - soy proteins

    Process conditions that are applied to make structured soy-protein-based food commonly include high temperatures. Those conditions can induce protein oxidation, leading to a decrease in their susceptibility to proteolysis by digestive enzymes. We aimed to investigate the effects of thermomechanical processing on oxidation and in vitro gastric digestion of commercial soy protein ingredients. Samples were sheared at 100 to 140 °C and characterized for acid uptake, carbonyl content, electrophoresis, and surface hydrophobicity. The enzymatic hydrolysis was determined in simulated gastric conditions. Protein ingredients were already oxidized and showed higher surface hydrophobicity and hydrolysis rate compared with those of the processed matrices. However, no clear correlation between the level of carbonyls and the hydrolysis rate was found. Therefore, we conclude that gastric digestion is mostly driven by the matrix structure and composition and the available contact area between the substrate and proteolytic enzymes.

    DELAY OF GERMINATION 1-LIKE 4 acts as an inducer of seed reserve accumulation
    Sall, Khadidiatou ; Dekkers, Bas J.W. ; Nonogaki, Mariko ; Katsuragawa, Yoshihiko ; Koyari, Ryosuke ; Hendrix, David ; Willems, Leo A.J. ; Bentsink, Leónie ; Nonogaki, Hiroyuki - \ 2019
    The Plant Journal 100 (2019)1. - ISSN 0960-7412 - p. 7 - 19.
    abscisic acid - dormancy - hormone - seed development - seed maturation - storage proteins

    More than 70% of global food supply depends on seeds. The major seed reserves, such as proteins, lipids, and polysaccharides, are produced during seed maturation. Here, we report that DELAY OF GERMINATION 1-LIKE 4 (DOGL4) is a major inducer of reserve accumulation during seed maturation. The DOGL family proteins are plant-specific proteins of largely unknown biochemical function. DOGL4 shares only limited homology in amino acid sequence with DOG1, a major regulator of seed dormancy. DOGL4 was identified as one of the outstanding abscisic acid (ABA)-induced genes in our RNA sequencing analysis, whereas DOG1 was not induced by ABA. Induction of DOGL4 caused the expression of 70 seed maturation-specific genes, even in germinating seeds, including the major seed reserves ALBUMIN, CRUCIFERIN and OLEOSIN. Although DOG1 affects the expression of many seed maturation genes, the major seed reserve genes induced by DOGL4 are not altered by the dog1 mutation. Furthermore, the reduced dormancy and longevity phenotypes observed in the dog1 seeds were not observed in the dogl4 mutants, suggesting that these two genes have limited functional overlap. Taken together, these results suggest that DOGL4 is a central factor mediating reserve accumulation in seeds, and that the two DOG1 family proteins have diverged over the course of evolution into independent regulators of seed maturation, but retain some overlapping function.

    Mug en daas in Baronie worden aangepakt
    Verdonschot, P.F.M. ; Dekkers, T.B.M. - \ 2019
    Met kennis de markt op
    Dekkers, B.L. ; Kortekaas, J.A. ; Meiling, Jan ; Houthoff, Iris ; Goot, A.J. van der; Berendse, Sebastiaan - \ 2019
    Marketing knowledge
    Kortekaas, J.A. ; Meiling, Jan ; Goot, A.J. van der; Dekkers, B.L. ; Houthoff, Iris ; Wijffels, R.H. ; Lindner, F. - \ 2019

    Researchers and students are increasingly being challenged to think about how they can market their knowledge. Various startups and spin-offs are already under development. ‘We no longer wait until an enterprising researcher wants to go into business.’

    Comparing structuring potential of pea and soy protein with gluten for meat analogue preparation
    Schreuders, Floor K.G. ; Dekkers, Birgit L. ; Bodnár, Igor ; Erni, Philipp ; Boom, Remko M. ; Goot, Atze Jan van der - \ 2019
    Journal of Food Engineering 261 (2019). - ISSN 0260-8774 - p. 32 - 39.
    Fibrous structures - Food processing - Plant protein - Shear cell processing - Shear-induced structuring

    Pea protein isolate can be combined with wheat gluten into materials with a fibrous morphology using shear induced structuring combined with heating. Results are partly in-line with soy protein isolate-wheat gluten blends, but the latter yields anisotropic materials in a much broader temperature range. Both blends also have the ability to include air. Air bubbles were aligned and deformed at process conditions that gave the most pronounce fibrous products. Mechanically, the pea protein-gluten materials processed at 140 °C had a similar strength as soy protein blends. At 110 and 120 °C, the pea protein blends had a strength that was comparable to a chicken meat reference (50–100 kPa) but weaker than their counterparts with soy (220–300 kPa). Blends of pea protein-gluten show potential for preparing structured plant protein materials, but the application area might be different compared with potential applications of soy protein-gluten blends.

    Maltodextrin promotes calcium caseinate fibre formation through air inclusion
    Wang, Zhaojun ; Dekkers, Birgit L. ; Boom, Remko ; Goot, Atze Jan van der - \ 2019
    Food Hydrocolloids 95 (2019). - ISSN 0268-005X - p. 143 - 151.
    Air bubble - Anisotropy - Calcium caseinate - Fibrous appearance - Maltodextrin

    Commercial calcium caseinate is available as spray-dried and roller-dried powder. Shearing a dense spray-dried calcium caseinate dispersion gives rise to a fibrous material, whereas shearing dense roller-dried calcium caseinate yields a layered material with only slight anisotropy in mechanical strength. The addition of a polysaccharide phase in a continuous protein phase may lead to formation of fibrous structures after shearing, which is hypothesized to be a result of the elongation and orientation of the dispersed polysaccharide domains. We report the effect of the addition of maltodextrin to roller-dried calcium caseinate on structure formation. The strength of the material increased with the addition of maltodextrin, which is partly caused by the withdrawal of water from the caseinate phase towards the maltodextrin phase, leading to a higher local caseinate concentration. The anisotropy of fracture stress and fracture strain were enhanced with up to 5 wt% maltodextrin. The effect of maltodextrin on the mechanical anisotropy and fibrous appearance could be ascribed to the greater air incorporation as a result of the presence of maltodextrin.

    Towards a sustainable banana supply chain in Colombia : Rainforest Alliance Certification and economic, social and environment conditions on small-scale banana plantations in Magdalena, Colombia
    Beekman, G. ; Dekkers, M. ; Koster, T. - \ 2019
    Wageningen : Wageningen Economic Research (Wageningen Economic Research report 2019-019) - ISBN 9789463435581 - 48
    De bodemfauna van het Markermeer : Markermeer bodemfaunakartering 2016 en MWTL-analyse
    Riel, M.C. van; Verdonschot, P.F.M. ; Dekkers, D.D. - \ 2018
    Wageningen : Zoetwaterecosystemen, Wageningen Environmental Research (Notitie Zoetwatersystemen, Wageningen Environmental Research ) - ISBN 9789463437516 - 48
    Software Development for Deterministic Prediction of Selection Response in Livestock Breeding Programs Using Genomic Information
    Su, H. ; Bijma, P. ; Werf, Julius van der; Dekkers, J.C.M. - \ 2018
    Journal of Animal Science 96 (2018)Supplement 2. - ISSN 0021-8812 - p. 19 - 19.
    Theory to predict selection response in traditional livestock breeding programs has been well developed, validated and implemented in software in the past decades, for example in SelAction (Rutten et al. 2002), which has been successful as a tool to predict selection response in traditional livestock breeding programs for a wide range of population structures and selection strategies. This software used standard quantitative genetics theory and selection index theory to develop deterministic recursive equations, which model changes of trait means and variance-covariance structures to predict asymptotic response to multiple trait selection using best linear unbiased prediction (BLUP) estimated breeding values (EBV). Nowadays genetic improvement can further be enhanced by genomic predictions, which provide more accurate estimates of breeding values of animals in their earlier life and can improve the efficiency of breeding programs. While statistical methods to estimate genomic breeding values are now widely available, optimizing the use of genomics in practical livestock breeding programs is limited due to the lack of computer software that implements available theories. We're hereby to present a computer program that extends SelAction. Genomic information is included as the average phenotype of groups of individuals with both genotypic and phenotypic information following Wientjes et al. (2016). The heterogeneity of genomic information is considered in terms of the degree of relationship between selection candidates and the individuals that are both genotyped and phenotyped (van der Werf et al., 2015). This software can be used by breeders to reliably compare alternative breeding programs and for investment decisions for breeding programs that include genomic information.
    Plant-Based Meat Analogues
    Kyriakopoulou, K. ; Dekkers, B.L. ; Goot, A.J. van der - \ 2018
    In: Sustainable Meat Production and Processing / Galanakis, Charis, Academic Press - ISBN 9780128148747 - p. 103 - 126.
    As the world's population increases, the need for reliable protein sources is growing. Meat is considered a good source of high biological value protein, but meat is not sustainable. In Western countries, the shift toward a diet with reduced meat consumption demands healthy and tasteful meat-free food products. Following this trend, the market turned toward vegetable proteins, such as pulses, wheat gluten and soy protein, which are processed into meat-like products, also known as meat analogues. These products approximate certain aesthetic qualities, such as texture, flavor, and color, and nutritional characteristics of specific types of meat. The development of new, attractive food products is a challenge already, but this challenge becomes even greater considering that these products are meant as a substitute for meat. This chapter discusses the insights concerning plant-based meat analogues, their production and future developments.
    Harnessing longitudinal information to identify genetic variation in tolerance of pigs to Porcine Reproductive and Respiratory Syndrome virus infection
    Lough, Graham ; Hess, Andrew ; Hess, Melanie ; Rashidi, Hamed ; Matika, Oswald ; Lunney, Joan K. ; Rowland, Raymond R.R. ; Kyriazakis, Ilias ; Mulder, Han A. ; Dekkers, Jack C.M. ; Doeschl-Wilson, Andrea - \ 2018
    Genetics, Selection, Evolution 50 (2018). - ISSN 0999-193X

    Background: High resistance (the ability of the host to reduce pathogen load) and tolerance (the ability to maintain high performance at a given pathogen load) are two desirable host traits for producing animals that are resilient to infections. For Porcine Reproductive and Respiratory Syndrome (PRRS), one of the most devastating swine diseases worldwide, studies have identified substantial genetic variation in resistance of pigs, but evidence for genetic variation in tolerance has so far been inconclusive. Resistance and tolerance are usually considered as static traits. In this study, we used longitudinal viremia measurements of PRRS virus infected pigs to define discrete stages of infection based on viremia profile characteristics. These were used to investigate host genetic effects on viral load (VL) and growth at different stages of infection, to quantify genetic variation in tolerance at these stages and throughout the entire 42-day observation period, and to assess whether the single nucleotide polymorphism (SNP) WUR10000125 (WUR) with known large effects on resistance confers significant differences in tolerance. Results: Genetic correlations between resistance and growth changed considerably over time. Individuals that expressed high genetic resistance early in infection tended to grow slower during that time-period, but were more likely to experience lower VL and recovery in growth by the later stage. The WUR genotype was most strongly associated with VL at early- to mid-stages of infection, and with growth at mid- to late-stages of infection. Both, single-stage and repeated measurements random regression models identified significant genetic variation in tolerance. The WUR SNP was significantly associated only with the overall tolerance slope fitted through all stages of infection, with the genetically more resistant AB pigs for the WUR SNP being also more tolerant to PRRS. Conclusions: The results suggest that genetic selection for improved tolerance of pigs to PRRS is possible in principle, but may be feasible only with genomic selection, requiring intense recording schemes that involve repeated measurements to reliably estimate genetic effects. In the absence of such records, consideration of the WUR genotype in current selection schemes appears to be a promising strategy to improve simultaneously resistance and tolerance of growing pigs to PRRS.

    Structuring processes for meat analogues
    Dekkers, Birgit L. ; Boom, Remko M. ; Goot, Atze Jan van der - \ 2018
    Trends in Food Science and Technology 81 (2018). - ISSN 0924-2244 - p. 25 - 36.
    Anisotropy - Fibrous products - Meat analogues - Plant protein - Structuring

    Background: Animal-derived protein foods, such as meat, have a large impact on the environment. Meat analogues are products that replace meat in its functionality, i.e. have similar product properties and sensory attributes, which is achieved by the fibrous nature of those products. Scope and approach: The techniques used to make fibrous products that mimic muscle meats are outlined and categorized based on their approach. The bottom-up approach refers to assembly of structural elements that are combined. The top-down approach refers to structuring of biopolymer blends using an overall force field. The strengths and weaknesses of these approaches are discussed in terms of ingredient and equipment use, (achievable) product resemblance, robustness, scalability, and resource efficiency. To enlarge the theoretical framework, the techniques with the top-down strategy are further contextualized by relating to structure formation processes of materials with other applications, and the methods to analyse the fibrous structures are further outlined. Key findings and conclusions: Techniques that follow the bottom-up strategy have the potential to resemble the structure of meat most closely, by structuring the proteins hierarchically through assembly of individual structural components. The top-down strategy is better scalable, is more efficient in its use of resources, but can only create the desired structure on larger length scales. Significant progress has been made on the methods to analyse structured products from the last category. Most analysis methods focussed on the (micro)structural anisotropy of the fibrous products, however there is also a need for methods that allow in situ analysis of the evolution of the structure during processing.

    Creation of fibrous plant protein foods
    Dekkers, Birgit L. - \ 2018
    Wageningen University. Promotor(en): A.J. van der Goot; R.M. Boom. - Wageningen : Wageningen University - ISBN 9789463433198 - 204
    cum laude

    A transition from animal to plant-based protein is required to produce sufficient protein for the growing world population, while at the same time mitigates climate change. Especially the production of meat imposes a burden on the environment. Meat analogues, which are products that are similar to meat in its functionality, can help consumers to lower their meat consumption. The anisotropic, fibrous nature of meat is perhaps the most important characteristic of meat, which can be mimicked by structuring biopolymers, such as proteins and polysaccharides with the shear cell technology. The aim of this thesis is to obtain insight in the key mechanisms that play a role in the transformation of plant-based biopolymer blends into anisotropic/fibrous structures with shear cell technology. These two key mechanisms are the deformation of the two phases present in biopolymer blends, and the subsequent entrapment of this deformation during solidification. It was concluded that successful structure formation requires matching of the properties of the two phases. During structuring at elevated temperature, the two phases are deformed, while subsequent cooling ensures entrapment of the deformed dispersed phase(s) in the (continuous) phase. Ideally, the continuous and dispersed phase have different strength in the final product,.

    Chapter 2 presents a method to determine the water distribution in soy protein isolate (SPI) – wheat gluten (WG) blends. The concentration of water in each separate phase was directly determined with time-domain nuclear magnetic resonance relaxometry (TD-NMR), and oscillatory rheology was used to indirectly asses the water distribution by determining the viscoelastic properties of the separate phases and the blend. It was shown that water distributes unevenly in SPI-WG blends: more water was absorbed by the SPI as compared to the WG phase. This methodology was developed for SPI-WG blends at room temperature and subsequently also applied to heated and sheared samples in Chapter 3. First, water distribution in the blend after a heat and/or shear treatment was assessed with TD-NMR and the outcomes were then used to predict the viscoelastic properties of the SPI and WG phase in the blend. This yielded insight in the deformability of the two phases in the blend. The viscoelastic properties were measured under conditions that are relevant for structure formation, i.e. during and after heating and shearing. It was shown that the water distribution was hardly affected by a heat or shear treatment, whereas the viscoelastic properties of the two phases changed significantly. The viscoelastic properties of SPI and WG became more similar due to water redistribution in the blend, which allows deformation and alignment of the dispersed phase during structuring.

    Chapter 4 describes a study using a model blend that mimics soy protein concentrate (SPC). It consists of a relatively pure protein phase, soy protein isolate (SPI), and a soluble, more or less pure polysaccharide phase, pectin. This SPI-pectin blend formed fibrous materials at a similar heating temperature as SPC, being 140°C. Pectin formed the dispersed phase and was deformed when heated and sheared at optimal conditions. Chapter 5 extends the study on structure formation with SPI-pectin blends. Here, the deformation of the dispersed pectin phase and the influence of incorporated air were considered. The fibrous nature of these products appears upon tearing, and originates from detachment through or along the long side of the weak dispersed phase(s), being pectin and/or air. A model based on the rule of mixing was used to predict the mechanical anisotropy based on the volume fraction and the deformation of the weak, dispersed phase. The size and orientation of the dispersed phases, tailored by using different shear rates, were related to differences in fracture behavior when deforming the structures. Besides deformation, the strength and volume fraction of the weak phase(s) were important when composing a blend for fibrous structure formation. In Chapter 6, the behavior of the SPI and pectin phases in a blend was investigated by determining the viscoelastic properties while shearing and heating over time. A closed cavity rheometer (CCR) was used to determine these properties under similar conditions as used during fibrous structure formation. The addition of a small amount of pectin (2.2 wt.%) to a SPI dispersion (41.8 wt.%) resulted in viscoelastic behavior that changed in time during a shear treatment at elevated temperatures. Although one can clearly discern two distinct phases with SEM, the viscoelastic behavior of the SPI-pectin blend is more complex than that of a simple composite material.

    Chapter 7 demonstrates the importance of the fractionation process on the structuring potential of soy proteins. An enriched soy protein fraction was obtained through an aqueous fractionation process. Those fractions could be used to make fibrous structures when: i) the soy protein fractions were toasted, which is a dry heating step, and ii) when a concentrate (75% protein) was combined with full fat flour, in such a ratio that the protein content was similar to commercial SPC. Toasting results in decreased protein solubility, increased water holding capacity and increased viscosity of the fractions, and these changes turned out to be important for fibrous structure formation.

    Lastly, literature was reviewed to put all findings in perspective (Chapter 8). An overview is presented of all techniques that are commercially used and currently investigated to create meat-like structures. Structuring techniques are compared in their approach, being either bottom-up, which refers to assembly of structural elements that are then combined, or top-down, which refers to structuring of biopolymer blends using an overall force field. A bottom-up strategy has the potential to resemble the structure of meat most closely, by structuring the molecules including proteins into structural components (e.g. muscle cells) followed by assembly of individual structural components. A top-down strategy is more efficient in its use of resources and is better scalable, but can only create the desired structure on larger length scales. The techniques with a top-down strategy were further investigated by reviewing literature on similar processes outside this particular field of application, i.e. not meant to create fibrous structures. These insights were subsequently translated to the conditions as used in structure formation for meat analogues.

    Chapter 9 concludes with a general discussion of all results presented in this thesis. The different chapters are integrated in design rules for fibrous structure formation. Furthermore, the complexity encountered when studying material and conditions during fibrous structure formation are discussed. Then, the potential and the challenges for understanding and applying fibrous structure formation with simple shear flow are summarized.

    The overall societal goal of developing meat analogue food products is to help consumers in the transition from animal-based to a more plant-based diet. The scientific goal to obtain insight in fibrous structure formation with the shear technology as developed in this thesis is of importance, and can be the basis for developing the technology for the next generation meat analogues.

    Towards sustainable cocoa in Côte d'Ivoire : The impacts and contribution of UTZ certification combined with services provided by companies
    Ingram, V. ; Rijn, F. van; Waarts, Y. ; Dekkers, M. ; Vos, B. de; Koster, T. ; Tanoh, R. ; Galo, A. - \ 2018
    Wageningen : Wageningen Economic Research (Wageningen Economic Research rapport 2018-041) - ISBN 9789463437769 - 137
    Stekende insecten Griendtsveen 2017 : notitie
    Verdonschot, Piet F.M. ; Dekkers, T.B.M. - \ 2018
    Wageningen : Zoetwaterecosystemen, Wageningen Environmental Research - ISBN 9789463432924 - 58
    De inventarisatie van steekmuglarven leverde in 2016 4 kleinere gebiedsdelen op met hoge aantallen steekmuglarven (de zogenaamde ‘hotspots’). In april-mei 2017 is de larveninventarisatie herhaald. Hieruit bleek dat de larven van de moerassteekmug A. cinereus over het gehele gebied verspreid zijn met op de ‘hotspots’ opnieuw hoogste aantallen. In de periode daarna vielen de meeste locaties droog. Het jaar 2017 was een droog jaar waarbij al vroeg in het voorjaar, mogelijk zelfs in de winter, veel potentiële tijdelijke wateren al droog stonden. Het patroon van ontwikkeling van volwassen steekmuggen liet over 2017 een ‘klassiek’ beeld van een moerassteekmuggenpopulatie zien met hoge aantallen in het voorjaar die daarna snel uitdoven. Alleen in juni trad additioneel een kleine populatie van plantenboorsteekmuggen op. Dit beeld is een gevolg van het opdrogen van tijdelijke wateren in het gebied in het voorjaar. De in totaal lagere aantallen in het gehele gebied en de beperking van deze aantallen tot de maand mei hebben ertoe geleid dat in het dorp Griendtsveen in 2017 geen overlast is ervaren. De verdeling van de aantallen over de jaren 2015, 2016 en 2017 naar zone rondom en in het dorp laat zien dat er ieder jaar een afname van de aantallen optreedt richting de dorpskern. In de periode 2015-2017 is het aantallen verzamelde knutten toegenomen met een factor 3. Dit kan samenhangen met nattere weilanden aan de zuidzijde, in het dorp en aan de westzijde. De adviezen voor maatregelen om de ‘hotspots’ aan te pakken zijn in 2017 in gang gezet en ten dele uitgevoerd
    DNA methylation as a mediator of the association between prenatal adversity and risk factors for metabolic disease in adulthood
    Tobi, Elmar W. ; Slieker, Roderick C. ; Luijk, René ; Dekkers, Koen F. ; Stein, Aryeh D. ; Xu, Kate M. ; Slagboom, P.E. ; Zwet, Erik W. Van; Lumey, L.H. ; Heijmans, Bastiaan T. ; T'Hoen, Peter A. ; Pool, René ; Greevenbroek, Marleen M. Van; Stehouwer, Coen D. ; Kallen, Carla J. Van Der; Schalkwijk, Casper G. ; Wijmenga, Cisca ; Zhernakova, Sasha ; Tigchelaar, Ettje F. ; Beekman, Marian ; Deelen, Joris ; Heemst, Diana Van; Veldink, Jan H. ; Berg, Leonard H. Van Den; Duijn, Cornelia M. Van; Hofman, Albert ; Uitterlinden, André G. ; Jhamai, P.M. ; Verbiest, Michael ; Verkerk, Marijn ; Breggen, Ruud Van Der; Rooij, Jeroen Van; Lakenberg, Nico ; Mei, Hailiang ; Bot, Jan ; Zhernakova, Dasha V. ; Hof, Peter Van 't; Deelen, Patrick ; Nooren, Irene ; Moed, Matthijs ; Vermaat, Martijn ; Jan Bonder, Marc ; Dijk, Freerk Van; Arindrarto, Wibowo ; Kielbasa, Szymon M. ; Swertz, Morris A. ; Isaacs, Aaron ; Franke, Lude - \ 2018
    Science Advances 4 (2018)1. - ISSN 2375-2548
    Although it is assumed that epigenetic mechanisms, such as changes in DNA methylation (DNAm), underlie the relationship between adverse intrauterine conditions and adult metabolic health, evidence from human studies remains scarce. Therefore, we evaluated whether DNAm in whole blood mediated the association between prenatal famine exposure and metabolic health in 422 individuals exposed to famine in utero and 463 (sibling) controls. We implemented a two-step analysis, namely, a genome-wide exploration across 342, 596 cytosine-phosphate-guanine dinucleotides (CpGs) for potential mediators of the association between prenatal famine exposure and adult body mass index (BMI), serum triglycerides (TG), or glucose concentrations, which was followed by formalmediation analysis.DNAm mediated the association of prenatal famine exposure with adult BMI and TG but not with glucose. DNAm at PIM3 (cg09349128), a gene involved in energy metabolism, mediated 13.4% [95% confidence interval (CI), 5 to 28%] of the association between famine exposure and BMI. DNAm at six CpGs, including TXNIP (cg19693031), influencing b cell function, and ABCG1 (cg07397296), affecting lipid metabolism, together mediated 80% (95% CI, 38.5 to 100%) of the association between famine exposure and TG. Analyses restricted to those exposed to famine during early gestation identified additional CpGs mediating the relationship with TG near PFKFB3 (glycolysis) and METTL8 (adipogenesis). DNAm at the CpGs involved was associated with gene expression in an external data set and correlated with DNAm levels in fat depots in additional postmortem data. Our data are consistent with the hypothesis that epigenetic mechanisms mediate the influence of transient adverse environmental factors in early life on long-termmetabolic health. The specific mechanism awaits elucidation.
    Viscoelastic properties of soy protein isolate - pectin blends: Richer than those of a simple composite material
    Dekkers, B.L. ; Boom, R.M. ; Goot, A.J. van der - \ 2018
    Food Research International 107 (2018). - ISSN 0963-9969 - p. 281 - 288.
    Concentrated soy protein isolate (SPI) – pectin blends acquire fibrous textures by shear-induced structuring while heating. The objective of this study was to determine the viscoelastic properties of concentrated SPI-pectin blends under similar conditions as during shear-induced structuring, and after cooling. A closed cavity rheometer was used to measure these properties under these conditions. At 140 °C, SPI and pectin had both a lower G* than the blend of the two and also showed a different behavior in time. Hence, the viscoelastic properties of the blend are richer than those of a simple composite material with stable physical phase properties. In addition, the G′pectin was much lower compared with the G′SPI and G′SPI-pectin upon cooling, confirming that pectin formed a weak dispersed phase. The results can be explained by considering that the viscoelastic properties of the blend are influenced by thermal degradation of the pectin phase. This degradation leads to: i) release of galacturonic acid, ii) lowering of the pH, and iii) water redistribution from the SPI towards the pectin phase. The relative importance of those effects are evaluated.
    Metabolic imaging of fatty kidney in diabesity : Validation and dietary intervention
    Jonker, Jacqueline T. ; Heer, Paul De; Engelse, Marten A. ; Rossenberg, Evelien H. Van; Klessens, Celine Q.F. ; Baelde, Hans J. ; Bajema, Ingeborg M. ; Koopmans, Sietse Jan ; Coelho, Paulo G. ; Streefland, Trea C.M. ; Webb, Andrew G. ; Dekkers, Ilona A. ; Rabelink, Ton J. ; Rensen, Patrick C.N. ; Lamb, Hildo J. ; Vries, Aiko P.J. De - \ 2018
    Nephrology Dialysis Transplantation 33 (2018)2. - ISSN 0931-0509 - p. 224 - 230.
    chronic kidney disease - fatty kidney - proton magnetic - renal triglyceride content - resonance spectroscopy - type 2 diabetes mellitus
    Background Obesity and type 2 diabetes have not only been linked to fatty liver, but also to fatty kidney and chronic kidney disease. Since non-invasive tools are lacking to study fatty kidney in clinical studies, we explored agreement between proton magnetic resonance spectroscopy (1 H-MRS) and enzymatic assessment of renal triglyceride content (without and with dietary intervention). We further studied the correlation between fatty kidney and fatty liver. Methods Triglyceride content in the renal cortex was measured by 1 H-MRS on a 7-Tesla scanner in 27 pigs, among which 15 minipigs had been randomized to a 7-month control diet, cafeteria diet (CAF) or CAF with low-dose streptozocin (CAF-S) to induce insulin-independent diabetes. Renal biopsies were taken from corresponding MRS-voxel locations. Additionally, liver biopsies were taken and triglyceride content in all biopsies was measured by enzymatic assay. Results Renal triglyceride content measured by 1 H-MRS and enzymatic assay correlated positively (r = 0.86, P < 0.0001). Compared with control diet-fed minipigs, renal triglyceride content was higher in CAF-S-fed minipigs (137 ± 51 nmol/mg protein, mean ± standard error of the mean, P < 0.05), but not in CAF-fed minipigs (60 ± 10 nmol/mg protein) compared with controls (40 ± 6 nmol/mg protein). Triglyceride contents in liver and kidney biopsies were strongly correlated (r = 0.97, P < 0.001). Conclusions Non-invasive measurement of renal triglyceride content by 1 H-MRS closely predicts triglyceride content as measured enzymatically in biopsies, and fatty kidney appears to develop parallel to fatty liver. 1 H-MRS may be a valuable tool to explore the role of fatty kidney in obesity and type 2 diabetic nephropathy in humans in vivo.
    Novel processing concepts for making fibrous food products
    Dekkers, B.L. ; Goot, A.J. van der - \ 2018
    In: Intensification of Biobased Processes / Górak, Andrzej, Stankiewicz, Andrzej, Royal Society of Chemistry (RSC Green Chemistry 55) - ISBN 9781782628552 - p. 462 - 477.
    A route to make Western diets more sustainable is through reduction of the consumption of animal-derived products. The simplest route to achieve this is to replace animal-derived products with vegetables, beans or pulses. However, modern consumers highly appreciate the texture and juiciness of meat. That is why scientists and food engineers aim to mimic the structure of meat using plant-derived ingredients. In this book chapter, we describe the need to reduce meat consumption in more detail and outline current processes to make today's meat analog products. However, the current products do not satisfy all consumer demands with respect to taste, texture and/or price. That is why we present novel routes and processing concepts currently being studied to make meat analogs. Those routes include concepts that aim to rebuild structures using molecular orientation, cellular imitation and methods that aim to alter naturally present structures in plant materials. The chapter ends by reviewing possible raw materials to be used in those applications and the importance of understanding the effect on functional properties when preparing the ingredients.
    The phase properties of soy protein and wheat gluten in a blend for fibrous structure formation
    Dekkers, B.L. ; Azad Emin, M. ; Boom, R.M. ; Goot, A.J. van der - \ 2018
    Food Hydrocolloids 79 (2018). - ISSN 0268-005X - p. 273 - 281.
    Fibrous macrostructures can be obtained from among others soy protein isolate (SPI) - wheat gluten (WG) blends, when deformed with simple shear flow while heating. This SPI-WG blend consists of two phases, which are separated on a micrometer scale. The properties, especially the rheological properties, of SPI- andWG-phases determine the structure formation process largely. The objective of this study was to determine the properties of the phases present in SPI-WG blends using conditions relevant for fibrous structure formation. Since, the rheological properties are dependent on the concentration of each protein
    in its respective phase, we determined the water content in the two phases with a methodology based on time-domain nuclear magnetic resonance. The spatial distribution of the two phases was studied with confocal scanning laser microscopy, and the rheological properties were measured with three types of
    oscillatory rheology. The experiments showed that the SPI-phase absorbed more water than the WGphase, which resulted in a larger volume fraction than mass fraction of the SPI-phase and vice versa for WG. The absorption of more water by SPI resulted in a lower concentration of SPI in that phase, remarkably leading to a G0-value for SPI that was similar to the rheological properties of WG. Similarities
    in rheological properties seem to be required to strongly deform and align the dispersed phase and form fibrous macrostructures.
    Aqueous fractionation processes of soy protein for fibrous structure formation
    Geerts, Marlies E.J. ; Dekkers, Birgit L. ; Padt, Albert van der; Goot, Atze Jan van der - \ 2018
    Innovative Food Science and Emerging Technologies 45 (2018). - ISSN 1466-8564 - p. 313 - 319.
    Desired properties of ingredients differ for various applications. Here, we use a reverse engineering approach to obtain soy protein fractions targeted for the application of meat analogs. Aqueous fractionation was used to produce these soy protein fractions, which were structured with simple shear flow deformation while heating. The water holding capacity (WHC), nitrogen solubility index (NSI), enthalpy of transition, and viscoelastic properties were determined. We found that a soy protein fraction/full fat flour blend resulted in distinct fibrous structures but only when the soy protein fraction was toasted at 150 °C. At this optimum toasting temperature (150 °C), the protein fractions had a high WHC, intermediate NSI and its viscoelastic property was characterized as G* between 1 and 10 kPa. These functional properties were shown to be key for fibrous structure formation, whereas, the influence of the state of the proteins was limited. Industrial relevance The market for meat analogs is growing. Nowadays, most of the meat analogs are produced with soy protein concentrates and isolates. These concentrates and isolates are obtained with conventional fractionation processes that involve organic solvents to extract the oil first. As a result, the application of these ingredients is limited, e.g. the product cannot be classified as organic. In this study, we therefore investigated aqueous fractionation of soy to obtain a soy protein fraction with desired functionality that can be used for the application of meat analogs and satisfy the values of consumers.
    Understanding fiber formation in a concentrated soy protein isolate - Pectin blend
    Dekkers, Birgit L. ; Hamoen, Remco ; Boom, Remko M. ; Goot, Atze Jan van der - \ 2018
    Journal of Food Engineering 222 (2018). - ISSN 0260-8774 - p. 84 - 92.
    Droplet breakup - Droplet coalescence - Mechanical properties - Microstructure - Shear-induced deformation - Water-in-water emulsion
    Concentrated blends of pectin in soy protein, subjected to simple shear flow while heated form solid, fibrous materials that are a basis for meat analogues. The commonly accepted ‘rule of mixing’ based on the cross-sectional area of a weak dispersed phase was used to predict mechanical anisotropy of the material. Experimentally, two different dispersed phases were observed in the continuous soy protein matrix; air and pectin. An optimum in shape anisotropy of the air and pectin droplets, and mechanical anisotropy was found for a shear rate of 39 s−1. At higher shear rates, air was expelled and break-up of pectin droplets was found, resulting in materials with hardly any mechanical anisotropy. There was discrepancy between the modeled and experimental data when using the same mass fraction and volume fraction of pectin, whereas the model fitted better when assuming that the pectin phase absorbs more water relatively to the soy phase.
    The phase behaviour of soy protein and wheat gluten blends used for fibrous structure formation
    Dekkers, Birgit - \ 2017
    Klimaatverandering in de Grote Polder en Polder Groenendijk : Workshopverslag
    Goosen, H. ; Rooij, L.L. de; Steingröver, E.G. ; Opdam, P.F.M. ; Haan, E. de; Dekkers, F. - \ 2017
    Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport ) - 18
    Het klimaat verandert en dat merken we langzaam maar zeker. Maar wat zijn hiervan de gevolgen op lokaal niveau? Om hier een beeld van te vormen is informatie over klimaatverandering en (land)gebruik samengebracht voor de Grote Polder en Polder Groenendijk. Kunnen we een eerste beeld vormen van wat klimaatverandering betekent voor het bedrijfsleven op het bedrijvenpark, voor de Heineken-brouwerij, voor de gemeente Zoeterwoude, voor het Hoogheemraadschap van Rijnland, voor de boeren, voor de natuur, en voor de mensen die er wonen en recreëren? Tijdens een bijeenkomst op 28 september 2017, georganiseerd door het Hoogheemraadschap van Rijnland in het kader van de Groene Thema Cirkel Water, is met diverse partijen uit het gebied het beeld besproken en zijn een aantal verhaallijnen afgeleid. Deze verhaallijnen worden verder verwerkt in de ‘story maps’ van de klimaateffectatlas Zuid Holland.
    De kracht van sport in de wijk voor: Kwetsbare jongeren
    Goor, Roel van; Super, Sabina ; Holman, Marije - \ 2017
    In: Kracht van Sport in de Wijk / Vervoorn, Cees, Deutekom, Marije, Dekkers, Vera, - p. 29 - 46.
    Lezingenreeks 2017: Kracht van Sport in de Wijk

    Biedt sport kwetsbare jongeren meer structuur in hun dagelijkse leven? Voelt een vluchteling zich eerder welkom door sportdeelname? Leert sport mensen met psychiatrische problemen beter om te gaan met tegenslag? In de vijfdelige lezingreeks ‘Kracht van Sport’ stond in 2017 de problematiek en inzet van sport bij diverse doelgroepen in de wijk centraal.

    In de lezingenreeks Kracht van Sport in de Wijk gingen experts op zoek naar manieren waarop welzijnswerkers, zorgverleners en professionals sport gezamenlijk als middel kunnen inzetten om de leefkwaliteit van wijkbewoners te verhogen.
    De kracht van sport in de wijk voor: Mensen met een beperking
    Kampen, Thomas ; Leenaars, Karlijn ; Weidemann, Kim - \ 2017
    In: Kracht van Sport in de Wijk / Vervoorn, Cees, Deutekom, Marije, Dekkers, Vera, - p. 13 - 28.
    Lezingenreeks 2017: Kracht van Sport in de Wijk

    Biedt sport kwetsbare jongeren meer structuur in hun dagelijkse leven? Voelt een vluchteling zich eerder welkom door sportdeelname? Leert sport mensen met psychiatrische problemen beter om te gaan met tegenslag? In de vijfdelige lezingreeks ‘Kracht van Sport’ stond in 2017 de problematiek en inzet van sport bij diverse doelgroepen in de wijk centraal.

    In de lezingenreeks Kracht van Sport in de Wijk gingen experts op zoek naar manieren waarop welzijnswerkers, zorgverleners en professionals sport gezamenlijk als middel kunnen inzetten om de leefkwaliteit van wijkbewoners te verhogen.
    Genome-wide analysis of bacterial determinants of plant growth promotion and induced systemic resistance by Pseudomonas fluorescens
    Cheng, X. ; Etalo, Desalegn W. ; Mortel, J.E. van de; Dekkers, E. ; Nguyen, Linh ; Medema, M.H. ; Raaijmakers, J.M. - \ 2017
    Environmental Microbiology 19 (2017)11. - ISSN 1462-2912 - p. 4638 - 4656.
    Pseudomonas fluorescens strain SS101 (Pf.SS101) promotes growth of Arabidopsis thaliana, enhances greening and lateral root formation, and induces systemic resistance (ISR) against the bacterial pathogen Pseudomonas syringae pv. tomato (Pst). Here, targeted and untargeted approaches were adopted to identify bacterial determinants and underlying mechanisms involved in plant growth promotion and ISR by Pf.SS101. Based on targeted analyses, no evidence was found for volatiles, lipopeptides and siderophores in plant growth promotion by Pf.SS101. Untargeted, genome-wide analyses of 7488 random transposon mutants of Pf.SS101 led to the identification of 21 mutants defective in both plant growth promotion and ISR. Many of these mutants, however, were auxotrophic and impaired in root colonization. Genetic analysis of three mutants followed by site-directed mutagenesis, genetic complementation and plant bioassays revealed the involvement of the phosphogluconate dehydratase gene edd, the response regulator gene colR and the adenylsulfate reductase gene cysH in both plant growth promotion and ISR. Subsequent comparative plant transcriptomics analyses strongly suggest that modulation of sulfur assimilation, auxin biosynthesis and transport, steroid biosynthesis and carbohydrate metabolism in Arabidopsis are key mechanisms linked to growth promotion and ISR by Pf.SS101.
    The genetic and biological basis of feed efficiency in mid-lactation Holstein dairy cows
    Hardie, L.C. ; VandeHaar, M.J. ; Tempelman, R.J. ; Weigel, K.A. ; Armentano, L.E. ; Wiggans, G.R. ; Veerkamp, R.F. ; Haas, Y. de; Coffey, M.P. ; Connor, E.E. ; Hanigan, M.D. ; Staples, C.R. ; Wang, Z. ; Dekkers, J.C.M. ; Spurlock, D.M. - \ 2017
    Journal of Dairy Science 100 (2017)11. - ISSN 0022-0302 - p. 9061 - 9075.
    Dairy - Feed efficiency - Genome-wide association study - Residual feed intake

    The objective of this study was to identify genomic regions and candidate genes associated with feed efficiency in lactating Holstein cows. In total, 4,916 cows with actual or imputed genotypes for 60,671 single nucleotide polymorphisms having individual feed intake, milk yield, milk composition, and body weight records were used in this study. Cows were from research herds located in the United States, Canada, the Netherlands, and the United Kingdom. Feed efficiency, defined as residual feed intake (RFI), was calculated within location as the residual of the regression of dry matter intake (DMI) on milk energy (MilkE), metabolic body weight (MBW), change in body weight, and systematic effects. For RFI, DMI, MilkE, and MBW, bivariate analyses were performed considering each trait as a separate trait within parity group to estimate variance components and genetic correlations between them. Animal relationships were established using a genomic relationship matrix. Genome-wide association studies were performed separately by parity group for RFI, DMI, MilkE, and MBW using the Bayes B method with a prior assumption that 1% of single nucleotide polymorphisms have a nonzero effect. One-megabase windows with greatest percentage of the total genetic variation explained by the markers (TGVM) were identified, and adjacent windows with large proportion of the TGVM were combined and reanalyzed. Heritability estimates for RFI were 0.14 (±0.03; ±SE) in primiparous cows and 0.13 (±0.03) in multiparous cows. Genetic correlations between primiparous and multiparous cows were 0.76 for RFI, 0.78 for DMI, 0.92 for MBW, and 0.61 for MilkE. No single 1-Mb window explained a significant proportion of the TGVM for RFI; however, after combining windows, significance was met on Bos taurus autosome 27 in primiparous cows, and nearly reached on Bos taurus autosome 4 in multiparous cows. Among other genes, these regions contain β-3 adrenergic receptor and the physiological candidate gene, leptin, respectively. Between the 2 parity groups, 3 of the 10 windows with the largest effects on DMI neighbored windows affecting RFI, but were not in the top 10 regions for MilkE or MBW. This result suggests a genetic basis for feed intake that is unrelated to energy consumption required for milk production or expected maintenance as determined by MBW. In conclusion, feed efficiency measured as RFI is a polygenic trait exhibiting a dynamic genetic basis and genetic variation distinct from that underlying expected maintenance requirements and milk energy output.

    Zinc absorption from milk is affected by dilution but not by thermal processing, and milk enhances absorption of Zinc from high-phytate rice in young dutch women
    Talsma, Elise F. ; Moretti, Diego ; Ly, Sou Chheng ; Dekkers, Renske ; Heuvel, Ellen G.H.M. van den; Fitri, Aditia ; Boelsma, Esther ; Stomph, Tjeerd Jan ; Zeder, Christophe ; Melse-Boonstra, Alida - \ 2017
    The Journal of Nutrition 147 (2017)6. - ISSN 0022-3166 - p. 1086 - 1093.
    Absorption - Food processing - Human - Isotope dilution - Milk - Phytate - Rice - Thermal processing - Zinc

    Background: Milk has been suggested to increase zinc absorption. The effect of processing and the ability of milk to enhance zinc absorption from other foods has not been measured directly in humans. Objective: We aimed to assess zinc absorption from 1) milk undergoing various processing and preparatory steps and 2) from intrinsically labeled high-phytate rice consumed with milk or water. Methods: Two randomized crossover studies were conducted in healthy young women [age:18-25 y; body mass index (in kg/m2): 20-25]: 1) a milk study (n = 19) comparing the consumption of 800 mL full-fat ultra-high temperature (UHT) milk [heat-treated milk (HTM)], full-fat UHT milk diluted 1:1 with water [heat-treated milk and water (MW)], water, or unprocessed (raw) milk (UM), each extrinsically labeled with 67Zn, and 2) a rice study (n = 18) comparing the consumption of 90 g intrinsically 67Zn-labeled rice with 600 mL of water [rice and water (RW)] or fullfat UHT milk [rice and milk (RM)]. The fractional absorption of zinc (FAZ) was measured with the double-isotope tracer ratio method. In vitro, we assessed zinc extraction from rice blended into water, UM, or HTM with or without phytate. Results: FAZ from HTM was 25.5% (95% CI: 21.6%, 29.4%) and was not different from UM (27.8%; 95% CI: 24.2%, 31.4%). FAZ from water was higher (72.3%; 95% CI: 68.7%, 75.9%), whereas FAZ fromMWwas lower (19.7%; 95% CI: 17.5%, 21.9%) than HTM and UM (both P < 0.01). FAZ from RM (20.7%; 95% CI: 18.8%, 22.7%) was significantly higher than from RW (12.8%; 95% CI: 10.8%, 14.6%; P < 0.01). In vitro, HTM and UM showed several orders of magnitude higher extraction of zinc from rice with HTM than from rice with water at various phytate concentrations. Conclusions: Milk enhanced human FAZ from high-phytate rice by 62% compared with water. Diluting milk with water decreases its absorption-enhancing proprieties, whereas UHT processing does not.

    Use of multi-trait and random regression models to identify genetic variation in tolerance to porcine reproductive and respiratory syndrome virus
    Lough, Graham ; Rashidi, Hamed ; Kyriazakis, Ilias ; Dekkers, Jack C.M. ; Hess, Andrew ; Hess, Melanie ; Deeb, Nader ; Kause, Antti ; Lunney, Joan K. ; Rowland, Raymond R.R. ; Mulder, Herman ; Doeschl-Wilson, Andrea - \ 2017
    Genetics, Selection, Evolution 49 (2017)1. - ISSN 0999-193X - p. 1 - 15.

    Background: A host can adopt two response strategies to infection: resistance (reduce pathogen load) and tolerance (minimize impact of infection on performance). Both strategies may be under genetic control and could thus be targeted for genetic improvement. Although there is evidence that supports a genetic basis for resistance to porcine reproductive and respiratory syndrome (PRRS), it is not known whether pigs also differ genetically in tolerance. We determined to what extent pigs that have been shown to vary genetically in resistance to PRRS also exhibit genetic variation in tolerance. Multi-trait linear mixed models and random regression sire models were fitted to PRRS Host Genetics Consortium data from 1320 weaned pigs (offspring of 54 sires) that were experimentally infected with a virulent strain of PRRS virus to obtain genetic parameter estimates for resistance and tolerance. Resistance was defined as the inverse of within-host viral load (VL) from 0 to 21 (VL21) or 0 to 42 (VL42) days post-infection and tolerance as the slope of the reaction-norm of average daily gain (ADG21, ADG42) on VL21 or VL42. Results: Multi-trait analysis of ADG associated with either low or high VL was not indicative of genetic variation in tolerance. Similarly, random regression models for ADG21 and ADG42 with a tolerance slope fitted for each sire did not result in a better fit to the data than a model without genetic variation in tolerance. However, the distribution of data around average VL suggested possible confounding between level and slope estimates of the regression lines. Augmenting the data with simulated growth rates of non-infected half-sibs (ADG0) helped resolve this statistical confounding and indicated that genetic variation in tolerance to PRRS may exist if genetic correlations between ADG0 and ADG21 or ADG42 are low to moderate. Conclusions: Evidence for genetic variation in tolerance of pigs to PRRS was weak when based on data from infected piglets only. However, simulations indicated that genetic variance in tolerance may exist and could be detected if comparable data on uninfected relatives were available. In conclusion, of the two defense strategies, genetics of tolerance is more difficult to elucidate than genetics of resistance.

    Semi-quantitative proteomics of mammalian cells upon short-term exposure to nonionizing electromagnetic fields
    Kuzniar, Arnold ; Laffeber, Charlie ; Eppink, Berina ; Bezstarosti, Karel ; Dekkers, Dick ; Woelders, Henri ; Zwamborn, A.P.M. ; Demmers, Jeroen ; Lebbink, Joyce H.G. ; Kanaar, Roland - \ 2017
    PLoS ONE 12 (2017)2. - ISSN 1932-6203

    The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein-and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture.

    Stekende insecten rondom de Groote Peel : nulmeting 2016
    Verdonschot, Piet F.M. ; Dekkers, Dorine D. - \ 2017
    Wageningen : Wageningen Environmental Research (Alterra), Zoetwatersystemen (Notitie / Zoetwaterecosystemen, Wageningen Environmental Research ) - ISBN 9789463431231 - 40
    culicidae - steken (activiteit) - insecten - hoogveengebieden - moerassen - noord-brabant - culicidae - stinging - insects - moorlands - marshes - noord-brabant
    Het doel van het project ‘Stekende insecten rondom de Groote Peel’ is tweeledig: a) Het verrichten van een Quick-scan risico-analyse van het gebied Groote Peel en met name de mogelijke effecten van de voorgenomen maatregelen in het project LIFE+ op eventuele overlast veroorzaakt door steekmuggen en knutten. b) Het in 2016 rondom de Groote Peel uitvoeren van een nulmeting om inzicht te krijgen in en het vastleggen van het voorkomen van steekmuggen en knutten rondom de lokaal aanwezige bebouwing en nabij natte randzones.
    Stekende insecten Griendtsveen 2016
    Verdonschot, Piet F.M. ; Dekkers, Dorine D. - \ 2017
    Wageningen : Wageningen Environmental Research (Alterra), Zoetwatersystemen (Notitie / Zoetwaterecosystemen, Wageningen Environmental Research ) - ISBN 9789463431248 - 81
    insecten - steken (activiteit) - culicidae - moerassen - hoogveengebieden - noord-brabant - insects - stinging - culicidae - marshes - moorlands - noord-brabant
    Het doel van het project is het terugdringen van de steekmuggenoverlast in Griendtsveen door: 1) Het in het maatregelenpakket van LIFE+ in de Mariapeel opnemen van een aangepast peilbeheer om de ontwikkeling van langdurig tijdelijke wateren tegen te gaan en de isolatie van langdurig tijdelijke wateren op te heffen. Hiervoor dienen de langdurig tijdelijke wateren die functioneren als broedplaats voor moerassteekmuggen te worden gekarteerd en dient de gebiedshydrologie en –morfologie te worden vastgelegd om doelgerichte maatregelen te kunnen formuleren. 2) Het instellen van een monitoringsmeetnet om de overlast van stekende insecten in en rondom het dorp Griendtsveen te kunnen volgen in de tijd. 3) Eventueel de verbindingszone waarlangs moerassteekmuggen migreren van het natuurgebied naar het dorp zo in te richten dat deze dient als barrière voor stekende insecten.
    Monitoring effecten zandsuppletie Leuvenumse beek 2016
    Verdonschot, Ralf ; Dekkers, Dorine ; Verdonschot, Piet - \ 2017
    Wageningen : Wageningen Environmental Research - ISBN 9789463431170 - 34
    waterlopen - herstel - ecologisch herstel - zandsuppletie - macrofauna - gelderland - streams - rehabilitation - ecological restoration - sand suppletion - macrofauna - gelderland
    In de Leuvenumse beek wordt vanaf 2014 het suppleren van zand als beekherstelmaatregel toegepast door Waterschap Vallei en Veluwe en Natuurmonumenten. Omdat over deze relatief nieuwe maatregel nog niet veel kennis voorhanden is, worden sindsdien de hydromorfologische en biologische ontwikkelingen gevolgd. In 2016 zijn in een aantal suppletietrajecten metingen verricht aan het profiel van de beekbodem, zijn substraatschattingen en metingen aan stroomsnelheid en diepte van de beek verricht en is de samenstelling van de macrofaunalevensgemeenschap onderzocht met behulp van een quickscan-techniek. De macrofauna- en substraatmetingen zijn een herhaling van metingen in 2014, zodat de ontwikkeling in de tijd is vastgelegd.
    The Gediz River fluvial archive : A benchmark for Quaternary research in Western Anatolia
    Maddy, D. ; Veldkamp, A. ; Demir, T. ; Gorp, W. van; Wijbrans, J.R. ; Hinsbergen, D.J.J. van; Dekkers, M.J. ; Schreve, D. ; Schoorl, J.M. ; Scaife, R. - \ 2017
    Quaternary Science Reviews 166 (2017). - ISSN 0277-3791 - p. 289 - 306.
    Buried river terraces - Fluvial archive - Gediz River - Pleistocene
    The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River Project (2001-2010) and present new data which leads to a revised stratigraphical model for the Early Pleistocene development of this fluvial system.In previous work we confirmed the preservation of eleven buried Early Pleistocene fluvial terraces of the Gediz River (designated GT11, the oldest and highest, to GT1, the youngest and lowest) which lie beneath the basalt-covered plateaux of the Kula Volcanic Province. Deciphering the information locked in this fluvial archive requires the construction of a robust geochronology. Fortunately, the Gediz archive provides ample opportunity for age-constraint based upon age estimates derived from basaltic lava flows that repeatedly entered the palaeo-Gediz valley floors. In this paper we present, for the first time, our complete dataset of 40Ar/39Ar age estimates and associated palaeomagnetic measurements. These data, which can be directly related to the underlying fluvial deposits, provide age constraints critical to our understanding of this sequence.The new chronology establishes the onset of Quaternary volcanism at ∼1320ka (MIS42). This volcanism, which is associated with GT6, confirms a pre-MIS42 age for terraces GT11-GT7. Evidence from the colluvial sequences directly overlying these early terraces suggests that they formed in response to hydrological and sediment budget changes forced by climate-driven vegetation change. The cyclic formation of terraces and their timing suggests they represent the obliquity-driven climate changes of the Early Pleistocene. By way of contrast the GT5-GT1 terrace sequence, constrained by a lava flow with an age estimate of ∼1247ka, span the time-interval MIS42 - MIS38 and therefore do not match the frequency of climate change as previously suggested. The onset of volcanism breaks the simple linkage of terracing to climate-driven change. These younger terraces more likely reflect a localized terracing process triggered by base level changes forced by volcanic eruptions and associated reactivation of pre-existing faults, lava dam construction, landsliding and subsequent lava-dammed lake drainage.Establishing a firm stratigraphy and geochronology for the Early Pleistocene archive provides a secure framework for future exploitation of this part of the archive and sets the standard as we begin our work on the Middle-Late Pleistocene sequence. We believe this work forms a benchmark study for detailed Quaternary research in Turkey.
    DELAY OF GERMINATION 1 plays a role in Arabidopsis seed maturation
    Dekkers, Bas ; He, Hanzi ; Hanson, Johannes ; Willems, Leo ; Cueff, Gwendal ; Rajjou, Loïc ; Hilhorst, Henk ; Bentsink, Leonie - \ 2016
    Wageningen University
    GSE65471 - Arabidopsis thaliana - GSE65471 - Arabidopsis thaliana - PRJNA274129
    We analysed the transcriptome of dry seeds (the end product of seed maturation) of three genotypes with different DOG1 expression levels. These included the WT Ler (low DOG1 expression), the near isogenic line NILDOG1-Cvi (strong DOG1 expression) and the non-dormant dog1-1 mutant (absence of DOG1 expression). NILDOG1-Cvi is the Ler WT containing an introgression of the Cvi accession on chromosome 5, which includes the DOG1 gene (Bentsink et al., 2006). The dog1-1 mutant is in the NILDOG1-Cvi genetic background.
    Dormant and after-ripened seeds are distinguished by early transcriptional differences in the imbibed state
    Dekkers, Bas ; Pearce, Simon P. ; Bolderen-Veldkamp, Marieke van; Holdsworth, Michael J. ; Bentsink, Leonie - \ 2016
    Wageningen University
    Arabidopsis thaliana - GSE76907 - Arabidopsis thaliana - GSE76907 - PRJNA308922
    We analyzed the transcriptome of dormant and after-ripened imbibed seeds of the Arabidopsis accession Cape verde Islands.
    Can we select for both resistance and tolerance of pigs to PRRS?
    Lough, G. ; Rashidi, H. ; Kyriazakis, Ilias ; Deeb, N. ; Dekkers, J.C.M. ; Lunney, J.K. ; Rowland, R. ; Mulder, H.A. ; Doeschl-Wilson, A. - \ 2016
    In: Book of Abstracts of the 67st Annual Meeting of the European Federation of Animal Science. - Wageningen Academic Publishers (Book of abstracts 22) - ISBN 9789086862849 - p. 318 - 318.
    Dormant and after-ripened Arabidopsis thaliana seeds are distinguished by early transcriptional differences in the imbibed state
    Dekkers, Bas J.W. ; Pearce, Simon P. ; Bolderen-Veldkamp, Marieke van; Holdsworth, Michael J. ; Bentsink, Leónie - \ 2016
    Frontiers in Plant Science 7 (2016). - ISSN 1664-462X
    After-ripening - Arabidopsis - Dormancy - Embryo - Endosperm - Seed - Transcriptome

    Seed dormancy is a genetically controlled block preventing the germination of imbibed seeds in favorable conditions. It requires a period of dry storage (after-ripening) or certain environmental conditions to be overcome. Dormancy is an important seed trait, which is under selective pressure, to control the seasonal timing of seed germination. Dormant and non-dormant (after-ripened) seeds are characterized by large sets of differentially expressed genes. However, little information is available concerning the temporal and spatial transcriptional changes during early stages of rehydration in dormant and nondormant seeds. We employed genome-wide transcriptome analysis on seeds of the model plant Arabidopsis thaliana to investigate transcriptional changes in dry seeds upon rehydration. We analyzed gene expression of dormant and after-ripened seeds of the Cvi accession over four time points and two seed compartments (the embryo and surrounding single cell layer endosperm), during the first 24 h after sowing. This work provides a global view of gene expression changes in dormant and non-dormant seeds with temporal and spatial detail, and these may be visualized via a web accessible tool ( A large proportion of transcripts change similarly in both dormant and non-dormant seeds upon rehydration, however, the first differences in transcript abundances become visible shortly after the initiation of imbibition, indicating that changes induced by after-ripening are detected and responded to rapidly upon rehydration. We identified several gene expression profiles which contribute to differential gene expression between dormant and non-dormant samples. Genes with enhanced expression in the endosperm of dormant seeds were overrepresented for stress-related Gene Ontology categories, suggesting a protective role for the endosperm against biotic and abiotic stress to support persistence of the dormant seed in its environment.

    The price of Dutch (Urban) Design: Measuring the impact of neighbourhood layout on house values - Presenting the research framework’
    Dekkers, J. ; Groot, J. de; Brink, A. van den - \ 2016
    Food Structure and Functionality Forum
    Dekkers, Birgit - \ 2016
    Presentation with subject: Towards understanding of the formation of layered and fibrous structures in dense biopolymer blends
    Food Colloids 2016
    Dekkers, Birgit - \ 2016
    Presentation with subject: Fibrous structures from a condensed water-in-water emulsion by simple shear flow deformation
    Impact of fitting dominance and additive effects on accuracy of genomic prediction of breeding values in layers
    Heidaritabar, M. ; Wolc, A. ; Arango, J. ; Zeng, J. ; Settar, P. ; Fulton, J.E. ; O'Sullivan, N.P. ; Bastiaansen, J.W.M. ; Fernando, R.L. ; Garrick, D.J. ; Dekkers, J.C.M. - \ 2016
    Journal of Animal Breeding and Genetics 133 (2016). - ISSN 0931-2668 - p. 334 - 346.
    Additive effect - Dominance effect - Genomic selection - Layer

    Most genomic prediction studies fit only additive effects in models to estimate genomic breeding values (GEBV). However, if dominance genetic effects are an important source of variation for complex traits, accounting for them may improve the accuracy of GEBV. We investigated the effect of fitting dominance and additive effects on the accuracy of GEBV for eight egg production and quality traits in a purebred line of brown layers using pedigree or genomic information (42K single-nucleotide polymorphism (SNP) panel). Phenotypes were corrected for the effect of hatch date. Additive and dominance genetic variances were estimated using genomic-based [genomic best linear unbiased prediction (GBLUP)-REML and BayesC] and pedigree-based (PBLUP-REML) methods. Breeding values were predicted using a model that included both additive and dominance effects and a model that included only additive effects. The reference population consisted of approximately 1800 animals hatched between 2004 and 2009, while approximately 300 young animals hatched in 2010 were used for validation. Accuracy of prediction was computed as the correlation between phenotypes and estimated breeding values of the validation animals divided by the square root of the estimate of heritability in the whole population. The proportion of dominance variance to total phenotypic variance ranged from 0.03 to 0.22 with PBLUP-REML across traits, from 0 to 0.03 with GBLUP-REML and from 0.01 to 0.05 with BayesC. Accuracies of GEBV ranged from 0.28 to 0.60 across traits. Inclusion of dominance effects did not improve the accuracy of GEBV, and differences in their accuracies between genomic-based methods were small (0.01-0.05), with GBLUP-REML yielding higher prediction accuracies than BayesC for egg production, egg colour and yolk weight, while BayesC yielded higher accuracies than GBLUP-REML for the other traits. In conclusion, fitting dominance effects did not impact accuracy of genomic prediction of breeding values in this population.

    Shear-induced fibrous structure formation from a pectin/SPI blend
    Dekkers, Birgit L. ; Nikiforidis, Costas ; Goot, Atze Jan van der - \ 2016
    Innovative Food Science and Emerging Technologies 36 (2016). - ISSN 1466-8564 - p. 193 - 200.
    Biopolymer incompatibility - Fibrous structure - High temperature shear cell - Protein-polysaccharide blend - Shear-induced structuring

    Well-defined shear flow can be applied to create fibrous, anisotropic samples from biopolymers when present at sufficiently high dry matter contents. Anisotropic biopolymer structures are of high interest especially when made from plant-based polymer blends due to novel food applications, like meat replacers. We investigate shear-induced structuring of a pectin/soy protein isolate (SPI) blend under heating. Scanning Electron Microscope analysis revealed that shear-induced structuring resulted in elongated pectin filaments, oriented in the direction of the shear flow, being entrapped in a continuous protein phase, inducing anisotropy in the blend. The length of the pectin filaments increased upon higher pectin concentrations and shearing temperatures, leading both to higher anisotropy, as measured with the tensile strength analysis. The fibrous appearance of samples became more evident when deforming the product by tearing, which effect was thought to be caused by detachment through or along the long side of the pectin filament. Industrial relevance The efficient preparation of fibrous products based on plant materials is of interest, because these products can be a starting point for the development of meat replacers. Meat replacers made from plant material are a promising, innovative, and sustainable source of protein for human consumption. With an increasing world population, creation of innovative sources of protein are needed to be able to feed everyone (United Nations - Department of Economic and Social Affairs, 2015). Proteins from plant sources, such as soy, are preferred over proteins from animal origin because plant based materials, for example, have lower environmental impact (Day, 2013; Mogensen, Hermansen, Halberg, Dalgaard, R., Vis, & Smith, 2009). In order to replace meat by a plant-based meat replacer, it is important that a similar product in terms of structural properties is developed to improve consumer acceptance (Hoek et al., 2011). Meat replacers are often produced with extrusion cooking, which is a process that has been applied for texturization of plant materials in the application of meat replacers for decades (Campbell, 1981; Harper & Clark, 1978). Previous research showed that a novel technique based on well-defined shear flow can also be used to create fibrous, anisotropic structures from plant-based biopolymers at sufficiently high dry matter contents, with a cone–cone device (Shear Cell) or a concentric cylinder device (Couette Cell) (Grabowska, Tekidou, Boom, & van der Goot, 2014; G. A. Krintiras, Göbel, Bouwman, van der Goot, & Stefanidis, 2014; Manski, van der Goot, & Boom, 2007). This novel technique uses milder conditions for structure formation, due to lower applied shear forces, and has therefore a lower specific mechanical energy input (Grabowska et al., 2016; G.A. Krintiras, Gadea Diaz, van der Goot, Stankiewicz, & Stefanidis, 2015).

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