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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Self-initiated nature conservation by farmers: ananalysis of Dutch farming
Runhaar, Hens ; Polman, N.B.P. ; Dijkshoorn-Dekker, M.W.C. - \ 2018
International Journal of Agricultural Sustainability (2018). - ISSN 1473-5903
In Europe, the active contribution of farmers to nature conservation is mainly voluntary. Whereas participation in agri-environmental schemes (AES) has been studied in detail, less is known about self-initiated nature conservation. Given the alarming decline in species diversity and abundance in agricultural landscapes, it is important to explore this form of conservation in more detail. In this paper we report on the results of a survey of Dutch dairy and arable farmers. We conclude that a large majority of farmers conduct self-initiated conservation activities on their farmyards and fields with varying ecological impacts and impacts on farming system. Helping birds was the most often mentioned activity. Farm size, on-farm side activities (in dairy farming), organic farming, the quality of the surrounding area and the absence of external constraints have a positive effect on the number of activities. Intensity has a negative effect on both the number of activities and on the probability that farmers conduct activities with substantial ecological impacts. There is no unambiguous evidence of a ‘crowding-out effect’ due to participation in AES. More research in this area can help contributing to a maximal exploitation of the conservation potential by farmers and to creating synergies with agri-environmental policies.
The sound of salts by Broadband Acoustic Resonance Dissolution Spectroscopy
Ruth, Saskia van; Dekker, Pieter ; Brouwer, Erwin ; Rozijn, Maikel ; Erasmus, Sara ; Fitzpatrick, Dara - \ 2018
Food Research International (2018). - ISSN 0963-9969 - 12 p.
Authenticity - BARDS - Food identity - Provenance - Resonance - Sound spectroscopy

Salts are available in different grades and in a wide price range. Some contain more impurities than others, while some have special culinary traits that determine their identity. Acoustic profiling, which is based on the ‘hot chocolate effect’ may provide an interesting strategy to characterise salts of various origins to underpin their identity. In this study, the link between the identity of 60 food grade and technical salts and their acoustic properties was examined by Broad Acoustic Resonance Dissolution Spectroscopy. In particular, the influence of the composition of the salts and the impact of the salts’ particle size distributions on their acoustic profiles were examined. Sodium and potassium contents were measured by flame photometry and the salts’ particle size distributions by laser light diffraction. Reference salts (NaCl, KCl, MgCl2) and mixtures thereof were analysed for comparison, as well as intact and ground versions of the salt samples. The results show that both the composition and morphology of the salt crystals determine the down-slope of the resonance frequency, which is caused by the rate of release of entrained and dissolved gas. Coarse salts with high levels of non-NaCl constituents showed a rapid decline in sound frequency, which corresponds to a high gas release rate. On the other hand fine salts composed of pure NaCl revealed a slower change in sound frequency and thus lower gas release rates. The frequency minimums were however not affected by the salts’ compositions nor particle size distributions. It is primarily the particle size distribution that affects the rate at which gas is released, and thus the change in sound frequency. Only when the particles are more similar in size, the composition also starts playing a role. Since both particle size distribution and composition is unique for each salt, the various salts show distinct acoustic profiles. Evidently, the current study shows that ‘listening’ to the sound of salts reveals interesting information about their identity and origin.

Global DNA Compaction in Stationary-Phase Bacteria Does Not Affect Transcription
Janissen, Richard ; Arens, Mathia M.A. ; Vtyurina, Natalia N. ; Rivai, Zaïda ; Sunday, Nicholas D. ; Eslami-Mossallam, Behrouz ; Gritsenko, Alexey A. ; Laan, Liedewij ; Ridder, Dick de; Artsimovitch, Irina ; Dekker, Nynke H. ; Abbondanzieri, Elio A. ; Meyer, Anne S. - \ 2018
Cell 174 (2018)5. - ISSN 0092-8674 - p. 1188 - 1199.e14.
DNA condensation - Dps - magnetic tweezers - nucleoid - RNA polymerase - single-molecule biophysics - stationary phase - stress response - transcription

In stationary-phase Escherichia coli, Dps (DNA-binding protein from starved cells) is the most abundant protein component of the nucleoid. Dps compacts DNA into a dense complex and protects it from damage. Dps has also been proposed to act as a global regulator of transcription. Here, we directly examine the impact of Dps-induced compaction of DNA on the activity of RNA polymerase (RNAP). Strikingly, deleting the dps gene decompacted the nucleoid but did not significantly alter the transcriptome and only mildly altered the proteome during stationary phase. Complementary in vitro assays demonstrated that Dps blocks restriction endonucleases but not RNAP from binding DNA. Single-molecule assays demonstrated that Dps dynamically condenses DNA around elongating RNAP without impeding its progress. We conclude that Dps forms a dynamic structure that excludes some DNA-binding proteins yet allows RNAP free access to the buried genes, a behavior characteristic of phase-separated organelles. Despite markedly condensing the bacterial chromosome, the nucleoid-structuring protein Dps selectively allows access by RNA polymerase and transcription factors at normal rates while excluding other factors such as restriction endonucleases.

Effects of a soil surfactant on grass performance and soil wetting of a fairway prone to water repellency
Dekker, Louis W. ; Ritsema, Coen J. ; Oostindie, Klaas ; Wesseling, Jan G. ; Geissen, Violette - \ 2018
Geoderma (2018). - ISSN 0016-7061 - 12 p.
Actual soil water repellency - Critical soil water content - N mineralization - Surfactant - Time Domain Reflectometry - Water drop penetration time (WDPT) test

This study reports on the effects of applications of a soil surfactant on improvement of grass performance and wetting of a sandy golf course fairway, located near Arnhem, the Netherlands. In addition, the influence of the surfactant on soil water repellency and the nitrogen contents in grass leaves, roots and upper 18 cm of the soil profile was investigated. The sandy soil of the fairway exhibits a water repellent behaviour resulting in a lot of localized dry spots (LDS) and poor turf quality during dry periods in spring and summer. In 2012 an experimental site on fairway 10 was divided into eight plots of 2 m by 2 m. Four plots were used as control and on four plots the surfactant was applied 6 times. The effects of the surfactant were studied on the wetting of the soil by measuring the volumetric water content at depths of 0–5 cm with a hand-held Time Domain Reflectometry (TDR) device. The grass performance was estimated in 3 distinct classes with percentages of the existence of green grass. Actual water repellency was assessed by putting water drops at regular distances along soil cores which were taken to a depth of 25 cm with a small, 1.5 cm diameter, auger. Applications of the soil surfactant resulted in dramatically improved soil wetting and turfgrass performance. Surfactant applications also resulted in more homogeneous wetting of the soil, reduced development of water repellency and preferential flow paths, and higher N concentration in soil. Since microbial mediated N mineralization is affected by moisture content, the higher N concentrations in the soil are thought to be related to the higher and more homogeneous moisture levels in the treated versus untreated plots. In addition to improved moisture availability, the better turf performance is likely affected by the increased plant available N in the soil which resulted from the more desirable and uniform moisture levels.

Isothiocyanates from Brassica Vegetables-Effects of Processing, Cooking, Mastication, and Digestion
Oliviero, Teresa ; Verkerk, Ruud ; Dekker, Matthijs - \ 2018
Molecular Nutrition & Food Research 62 (2018)18. - ISSN 1613-4125
Digestion - Glucosinolates - Isothiocyanates - Mastication - Processing

The formation of health-beneficial isothiocyanates (ITCs) from glucosinolates depends on a wide variety of plant-intrinsic factors (e.g., concentration of glucosinolates, activity of myrosinase, and specifier proteins) and on a multitude of extrinsic postharvest factors such as the conditions used during industrial processing, domestic preparation, mastication, and digestion. All of these factors contribute to a large variability in the formation of ITCs (and other breakdown products), as well as their intake and absorption upon consumption of Brassica vegetables. This uncertainty in ITC intake and absorption is a barrier for the determination of an optimal Brassica vegetable consumption pattern. In this review, the intrinsic and extrinsic factors that affect the formation, intake, and absorption of ITCs are described according to the most recent findings. The focus of this review includes the hydrolysis reaction mechanisms, the elucidation of the primary factors that play a role in the hydrolysis reaction, the influence of processing and cooking conditions, the effect of chewing, and the roles of the gastric and upper intestinal phases, including the effect of the meal composition (e.g., the effect of other meal compounds present during digestion) on the potential formation of ITCs.

A Global Analysis of Future Water Deficit Based On Different Allocation Mechanisms
Bijl, David L. ; Biemans, Hester ; Bogaart, Patrick W. ; Dekker, Stefan C. ; Doelman, Jonathan C. ; Stehfest, Elke ; Vuuren, Detlef P. van - \ 2018
Water Resources Research 54 (2018)8. - ISSN 0043-1397 - p. 5803 - 5824.
integrated assessment model - irrigation - socioeconomic development - water demand - water scarcity - water-food-energy nexus

Freshwater scarcity is already an urgent problem in some areas but may increase significantly in the future. To assess future developments, we need to understand how future population growth, agricultural production patterns, energy use, economic development, and climate change may impact the global freshwater cycle. Integrated models provide opportunities for quantitative assessment. In this paper, we further integrate models of hydrology and economics, using the models IMAGE and LPJmL, with explicit accounting for (1) electricity, industry, and municipal and irrigation water use; (2) intersectoral water allocation rules at the 0.5° × 0.5°grid scale; and (3) withdrawal, consumption, and return flows. With the integration between hydrology and economy we are able to understand competition dynamics between the different freshwater users at the basin and grid scale. We run model projections for three Shared Socioeconomic Pathways (SSPs), more efficient water use, and no expansion of irrigated areas to understand the competition dynamics of these different allocation mechanisms. We conclude that (1) global water withdrawal is projected to increase by 12% in SSP-1, 26% in SSP-2, and 29% in SSP-3 during 2010–2050; (2) water deficits (demand minus allocated water) for nonagricultural uses are small in 2010 but become significant around 2050; (3) interannual variability of precipitation results in variability of water deficits; (4) water use efficiency improvements reduce water withdrawal but have little impact on water deficits; and (5) priority rules at the local level have a large effect on water deficits, whereas limiting the expansion of irrigation has virtually no effect.

Resilience of tropical tree cover : The roles of climate, fire, and herbivory
Staal, Arie ; Nes, Egbert H. van; Hantson, Stijn ; Holmgren, Milena ; Dekker, Stefan C. ; Pueyo, Salvador ; Xu, Chi ; Scheffer, Marten - \ 2018
Global Change Biology 24 (2018)11. - ISSN 1354-1013 - p. 5096 - 5109.
alternative stable states - bistability - forest - grasslands - livestock - model - regime shifts - remote sensing - tipping points - wildfire

Fires and herbivores shape tropical vegetation structure, but their effects on the stability of tree cover in different climates remain elusive. Here, we integrate empirical and theoretical approaches to determine the effects of climate on fire- and herbivore-driven forest-savanna shifts. We analyzed time series of remotely sensed tree cover and fire observations with estimates of herbivore pressure across the tropics to quantify the fire–tree cover and herbivore–tree cover feedbacks along climatic gradients. From these empirical results, we developed a spatially explicit, stochastic fire-vegetation model that accounts for herbivore pressure. We find emergent alternative stable states in tree cover with hysteresis across rainfall conditions. Whereas the herbivore–tree cover feedback can maintain low tree cover below 1,100 mm mean annual rainfall, the fire–tree cover feedback can maintain low tree cover at higher rainfall levels. Interestingly, the rainfall range where fire-driven alternative vegetation states can be found depends strongly on rainfall variability. Both higher seasonal and interannual variability in rainfall increase fire frequency, but only seasonality expands the distribution of fire-maintained savannas into wetter climates. The strength of the fire–tree cover feedback depends on the spatial configuration of tree cover: Landscapes with clustered low tree-cover areas are more susceptible to cross a tipping point of fire-driven forest loss than landscapes with scattered deforested patches. Our study shows how feedbacks involving fire, herbivores, and the spatial structure of tree cover explain the resilience of tree cover across climates.

Osmotic dehydration of mango : Effect of vacuum impregnation, high pressure, pectin methylesterase and ripeness on quality
Sulistyawati, Ita ; Dekker, Matthijs ; Fogliano, Vincenzo ; Verkerk, Ruud - \ 2018
Food Science and Technology = Lebensmittel-Wissenschaft und Technologie 98 (2018). - ISSN 0023-6438 - p. 179 - 186.
High pressure - Mango fruit - Maturity - Osmotic dehydration - Vacuum impregnation

The effects of pretreatment with vacuum impregnation (VI) and high pressure (HP) and adding pectin methylesterase (PME) with calcium on the quality of osmotic dehydrated mango of different ripeness were investigated. Unripe and ripe ‘Kent’ mango cubes were osmotic dehydrated (OD at 50 °C in 60 °Brix sucrose solution containing 2 g calcium lactate/100 g and 0 or 0.48 mL PME/100 g), preceded either by VI (OD-VI) or HP (OD-HP). Use of unripe mango in OD showed two to five-fold higher soluble solid gain (SSG) compared to ripe mango for all treatments. Unripe mango pretreated with OD-VI showed the lowest water loss (WL) and the highest SSG. OD-HP had a similar but less pronounced effect as OD-VI on WL and SSG. Hue (h*) were generally preserved and color intensity (C*) were maintained or only slightly increased in both ripeness in all treatments. Lightness (L*) was greatly reduced in unripe mango but stable in ripe mango. In general, firmness and work of shear slightly increased when adding PME.

Groen in de stad : het perspectief van de vastgoedsector
Dijkshoorn-Dekker, Marijke ; Kortstee, Harry ; Michels, Rolf ; Polman, Nico - \ 2018
Den Haag : Wageningen Economic Research - 36
Resilience of tropical forest and savanna: bridging theory and observation
Staal, Arie - \ 2018
Wageningen University. Promotor(en): Marten Scheffer, co-promotor(en): Egbert van Nes; S.C. Dekker. - Wageningen : Wageningen University - ISBN 9789463438353 - 221
Bewustwording (toekomstige) ondernemers natuurinclusieve landbouw
Dijkshoorn-Dekker, Marijke - \ 2018
Body-fat indicators and kidney function decline in older post-myocardial infarction patients : The Alpha Omega Cohort Study
Esmeijer, Kevin ; Geleijnse, Johanna M. ; Giltay, Erik J. ; Stijnen, Theo ; Dekker, Friedo W. ; Fijter, Johan W. de; Kromhout, Daan ; Hoogeveen, Ellen K. - \ 2018
European Journal of Preventive Cardiology 25 (2018)1. - ISSN 2047-4873 - p. 90 - 99.
Cardiovascular disease - Kidney function - Obesity - Risk factors

Background: Obesity increases risk of hypertension and diabetes, the leading causes of end-stage renal disease. The effect of obesity on kidney function decline in stable post-myocardial infarction patients is poorly documented. This relation was investigated in a large cohort of older post-myocardial infarction patients. Design: Data were analysed from 2410 post-myocardial infarction patients in the Alpha Omega Trial, aged 60–80 years receiving optimal pharmacotherapy treatment (79% men, 18% diabetes). Methods: Cystatin C based estimated glomerular filtration rate (eGFRcysC) was calculated at baseline and after 41 months, using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Obesity was defined as body mass index ≥ 30 kg/m2 and high waist circumference as ≥102 and ≥88 cm for men and women. The relation between body mass index, waist circumference and annual eGFRcysC decline was evaluated by linear regression. Results: At baseline, mean (standard deviation) eGFRcysC was 81.5 (19.6) ml/min/1.73 m2, 23% of all patients were obese. After multivariable adjustment, the annual mean (95% confidence interval) eGFRcysC decline in men and women was –1.45 (–1.59 to –1.31) and –0.92 (–1.20 to –0.63) ml/min/1.73 m2, respectively (p = 0.001). Obese versus non-obese patients and patients with high versus normal waist circumference experienced greater annual eGFRcysC decline. Men and women showed an additional annual eGFRcysC decline of –0.35 (–0.56 to –0.14) and –0.21 (–0.55 to 0.14) ml/min/1.73 m2 per 5 kg/m2 body mass index increment (p for interaction 0.3). Conclusions: High compared to normal body mass index or waist circumference were associated with more rapid kidney function decline in older stable post-myocardial infarction patients receiving optimal drug therapy.

Forest-rainfall cascades buffer against drought across the Amazon
Staal, Arie ; Tuinenburg, Obbe A. ; Bosmans, Joyce H.C. ; Holmgren, Milena ; Nes, Egbert H. van; Scheffer, Marten ; Zemp, Delphine Clara ; Dekker, Stefan C. - \ 2018
Nature Climate Change 8 (2018)6. - ISSN 1758-678X - p. 539 - 543.

Tree transpiration in the Amazon may enhance rainfall for downwind forests. Until now it has been unclear how this cascading effect plays out across the basin. Here, we calculate local forest transpiration and the subsequent trajectories of transpired water through the atmosphere in high spatial and temporal detail. We estimate that one-third of Amazon rainfall originates within its own basin, of which two-thirds has been transpired. Forests in the southern half of the basin contribute most to the stability of other forests in this way, whereas forests in the south-western Amazon are particularly dependent on transpired-water subsidies. These forest-rainfall cascades buffer the effects of drought and reveal a mechanism by which deforestation can compromise the resilience of the Amazon forest system in the face of future climatic extremes.

Leaching and degradation kinetics of glucosinolates during boiling of Brassica oleracea vegetables and the formation of their breakdown products
Hanschen, Franziska S. ; Kühn, Carla ; Nickel, Marie ; Rohn, Sascha ; Dekker, Matthijs - \ 2018
Food Chemistry 263 (2018). - ISSN 0308-8146 - p. 240 - 250.
Brassica - Epithionitriles - Epithiospecifier protein - Glucosinolates - Isothiocyanates - Modeling - Nitriles - Processing
Domestic processing methods, such as boiling, significantly affect the glucosinolate content and the formation of breakdown products in Brassica vegetables. Here, we comprehensively describe the effect of aqueous heat treatment on the degradation and leaching kinetics of glucosinolates on the formation of their enzymatic and non-enzymatic hydrolysis and breakdown products. The results were correlated with the inactivation kinetics of myrosinase and epithiospecifier protein activity in the Brassica oleracea vegetables kohlrabi, white cabbage, and red cabbage. Short-term heating increased isothiocyanate formation due to inactivation of the epithiospecifier protein. Myrosinase was inactivated shortly after that. Boiling led to leaching of glucosinolates and their hydrolysis products into the boiling water. Heating to 99 °C resulted in thermally-induced glucosinolate breakdown and nitrile formation, both in vegetables and boiling water. Finally, kinetic modeling not only revealed differences in myrosinase inactivation among the vegetables, but also glucosinolate leaching and degradation kinetics differed between individual glucosinolates and vegetables.
Effect of Vacuum Frying on Quality Attributes of Fruits
Ayustaningwarno, Fitriyono ; Dekker, Matthijs ; Fogliano, Vincenzo ; Verkerk, Ruud - \ 2018
Food Engineering Reviews 10 (2018)3. - ISSN 1866-7910 - p. 154 - 164.
Fruit - Matrix - Phytochemicals - Quality attributes - Vacuum frying
Vacuum frying of fruits enables frying at lower temperatures compared to atmospheric frying, thereby improving quality attributes of the fried product, such as oil content, texture, retention of nutrients, and color. Producing high-quality vacuum-fried fruit is a challenge, especially because of the high initial water content of fruits that requires long frying times. Factors influencing vacuum-fried fruit quality attributes are the type of equipment, pre-treatments, processing conditions, fruit type, and fruit matrix. Pre-treatments such as hot air, osmotic drying, blanching, freezing, impregnation, anti-browning agents, and hydrocolloid application strongly influence the final quality attributes of the products. The vacuum-frying processing parameters, namely frying time, temperature, and vacuum pressure, have to be adjusted to the fruit characteristics. Tropical fruits have different matrix properties, including physical and chemical, which changed during ripening and influenced vacuum-fried tropical fruit quality. This paper reviews the state of the art of vacuum frying of fruit with a specific focus on the effect of fruit type and matrix on the quality attributes of the fried product.
The effect of chewing on oral glucoraphanin hydrolysis in raw and steamed broccoli
Sarvan, Irmela ; Klauw, Michelle van der; Oliviero, Teresa ; Dekker, Matthijs ; Verkerk, Ruud - \ 2018
Journal of Functional Foods 45 (2018). - ISSN 1756-4646 - p. 306 - 312.
Brassicaceae - Broccoli - Chewing - Glucosinolate - Sulforaphane - Thermal treatment
Chewing disrupts broccoli cells, and myrosinase can effectively hydrolyze the glucosinolate glucoraphanin into the biological active sulforaphane. The influence of chewing time and steaming time on glucoraphanin hydrolysis as well as sulforaphane and sulforaphane nitrile formation in broccoli was studied. To study the effect of chewing time on differently steamed broccoli, broccoli was chewed for 11 s, 22 s, 30 s and 40 s by volunteers. To determine the effect of steaming time, raw and steamed broccoli samples were chewed for 22 s. Glucoraphanin, sulforaphane and sulforaphane nitrile were analyzed in all samples. Longer chewing times of raw, 0.5-min and 1-min steamed broccoli, which contained active myrosinase, lead to a higher hydrolysis. The highest hydrolysis rate of glucoraphanin was found in 0.5-min steamed broccoli (38%) and 2-min steamed samples which contained the highest sulforaphane concentration. This could lead to a recommendation to steam broccoli for a short time before consumption.
Bioavailability of Isothiocyanates From Broccoli Sprouts in Protein, Lipid, and Fiber Gels
Oliviero, Teresa ; Lamers, Simone ; Capuano, Edoardo ; Dekker, Matthijs ; Verkerk, Ruud - \ 2018
Molecular Nutrition & Food Research 62 (2018)18. - ISSN 1613-4125
Bioavailability - Fibers - Gels - Isothiocyanates - Lipids - Proteins
Scope: Optimization of bioavailability of dietary bioactive health-beneficial compounds is as important as increasing their concentration in foods. The aim of this study is to explore the change in bioavailability of isothiocyanates (ITCs) in broccoli sprouts incorporated in protein, fiber, and lipid gels. Methods and results: Five participants took part in a cross-over study and collected timed urine samples up to 24 h after consumption of proteins, dietary fibers, and lipid gels containing broccoli sprouts powder. Sulforaphane and iberin metabolites were determined in the urine samples. Samples in which sulforaphane and iberin were preformed by myrosinase led to a higher bioavailability of those compounds. Compared to the control broccoli sprout, incorporation of sprouts in gels led to lower bioavailability for preformed sulforaphane and iberin (although for sulforaphane the lower bioavailability was not significantly different) whereas for the gels rich in their precursors, glucoraphanin and glucoiberin, the opposite trend was observed (although not significantly different). Conclusion: This explorative study suggests that ITCs bioavailability can be modulated by food structure and composition and further and deeper investigations are needed to develop food products that lead to an optimized ITCs bioavailability.
Ervaringen met het Ventilation Jet systeem bij Dekker Chrysanten : als onderdeel van het monitoringsproject
Vanthoor, B.H.E. ; Tsafaras, I. - \ 2018
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport / Wageningen University & Research, BU Glastuinbouw WPR-743) - 22
The purpose of the Ventilation Jet (VJ) system at Dekker Chrysanten is to reduce the temperature of the grow pipe in order to save energy. Dekker Chrysanten encountered problems with circles in the crop in the VJ compartment in many cultivation rounds in 2016 and 2017. Early flowering took place at these circles, which occasionally resulted in poorer quality and shorter stems. Due to these cultivation problems, Dekker Chrysanten did not want to reduce yet the minimum grow pipe in the Ventilation Jet compartment. Due to the efforts of the growers and the monitoring project, potential causes have been identified and solved such as (1) the prevention of dry spots in the soil by: switching off the VJ when there is irrigation, switching on the VJ later in the short day period and by irrigating more (this is done companywide); (2) lowering the relative humidity setpoint in the VJ compartment at night so that a higher night evaporation is achieved; (3) improving the air flow profile of the bottom fan and (4) adjusting the climate computer software, resulting in a much more stable temperature and RH in the VJ compartment. The above learning experiences are now applied which has resulted in a good quality chrysanthemum in the past cultivation period (harvest January 2018).
Circulating Polyunsaturated Fatty Acids as Biomarkers for Dietary Intake across Subgroups : The CODAM and Hoorn Studies
Wanders, Anne J. ; Alssema, Marjan ; Hoon, Sabine E.M. De; Feskens, Edith J.M. ; Woudenbergh, G.J. van; Kallen, Carla J. van der; Zock, Peter L. ; Refsum, Helga ; Drevon, Christian A. ; Elshorbagy, Amany ; Schalkwijk, Casper G. ; Stehouwer, Coen D.A. ; Dekker, Jacqueline M. ; Greevenbroek, Marleen M.J. van - \ 2018
Annals of Nutrition & Metabolism 72 (2018)2. - ISSN 0250-6807 - p. 117 - 125.
Biomarker - Circulating fatty acids - Dietary fat - Polyunsaturated fat
Aims: To evaluate whether participant characteristics and way of expressing circulating fatty acids (FA) influence the strengths of associations between self-reported intake and circulating levels of linoleic acid (LA), alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Methods: Cross-sectional analyses were performed in pooled data from the CODAM (n = 469) and Hoorn (n = 702) studies. Circulating FA were measured by gas liquid chromatography and expressed as proportions (% of total FA) and concentrations (µg/mL). Dietary intakes were calculated from a validated food frequency questionnaire. Effects of participant characteristics on associations between dietary and circulating FA were calculated using interaction analyses. Results: Standardized regression coefficients between dietary FA and proportions of circulating FA (% of total FA) were LA β = 0.28, ALA β = 0.13, EPA β = 0.34, and DHA β = 0.45. Body mass index (BMI), waist circumference, and presence of CVD influenced associations for LA; gender influenced LA, EPA, and DHA; alcohol intake influenced LA and DHA; and glucose tolerance status influenced ALA (p values interaction <0.05). Coefficients for circulating FA as concentrations were LA β = 0.19, ALA β = 0.10, EPA β = 0.31, and DHA β = 0.41. Conclusions: This study suggests that characteristics such as BMI, alcohol intake, and expressing circulating FA as proportions or concentrations, influence associations between dietary and circulating FA.
A foot-and-mouth disease SAT2 vaccine protects swine against experimental challenge with a homologous virus strain, irrespective of mild pathogenicity in this species
Mouton, Laure ; Dekker, Aldo ; Bleijenberg, Meindert ; Blanchet, Michel ; Coco-Martin, Jose ; Hudelet, Pascal ; Goutebroze, Sylvain - \ 2018
Vaccine 36 (2018)15. - ISSN 0264-410X
Challenge - Foot-and-mouth disease - Pigs - Serotype SAT - Vaccine efficacy
FMDV serotype SAT2 is most frequently associated with outbreaks in ruminants. However, the risk of it spreading from cattle to pigs cannot be excluded. To assess the efficacy of an SAT2-type FMD inactivated vaccine against homologous challenge in pigs, a suitable challenge strain adapted to pigs was produced. After two passages in two pigs each, a FMDV stock of SAT2 challenge strain was produced. This material was used to infect two groups of five pigs. The first group being vaccinated 28 days before challenge and the other one left as an unvaccinated control. Clinical signs were recorded, virus shedding was assessed on mouth swabs, and neutralising antibody titres were determined. At least 80% of the vaccinated pigs were protected against clinical disease. Furthermore, no virus shedding was observed in any of the vaccinated pigs. This study shows that experimentally inoculated pigs can become infected with a SAT2 serotype. Furthermore, vaccination offers protection against generalisation and viral excretion, confirming the potential of vaccination as an important tool in the control of FMD in pigs.
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