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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    Instructievideo Cuvet
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    meetinstrumenten - instrumenten (meters) - absorptiegraad - indicating instruments - instruments - absorbance
    Instructievideo over het gebruik van een cuvet
    Conductometer Schott
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    geleidingsvermogen - instrumenten (meters) - meetinstrumenten - chemie - conductivity - instruments - indicating instruments - chemistry
    Instructievideo over het gebruik van de Schott Conductometer
    Kalibratie pH meter Inolab
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    ph - zuurgraad - meetinstrumenten - instrumenten (meters) - kalibratie - ph - acidity - indicating instruments - instruments - calibration
    Instructievideo over de kalibratie van de InoLab pH meter
    pH meter Inolab
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    ph - zuurgraad - instrumenten (meters) - meetinstrumenten - ph - acidity - instruments - indicating instruments
    Instructievideo over het gebruik van de Inolab pH meter
    Spectrofotometer VWR
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    absorptiegraad - meetinstrumenten - instrumenten (meters) - optische instrumenten - spectra - absorbance - indicating instruments - instruments - optical instruments - spectra
    Instructievideo over het gebruik van de VWR spectofotometer
    Spectrofotometer LKB
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    spectra - absorptiegraad - instrumenten (meters) - meetinstrumenten - spectra - absorbance - instruments - indicating instruments
    Instructievideo over het gebruik van de LKB Spectofotometer
    Metrohm Buret
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    titratie - chemie - instrumenten (meters) - titration - chemistry - instruments
    Instructievideo over het gebruik van de Metrohm Buret
    Kalibratie pH meter Schott
    Bom, Jesse ; Dijksman, J.A. ; Lageschaar, Luuk ; Galen, Martijn van; Hoogendam, C.W. ; Wegh, R.A.J. - \ 2016
    Wageningen : Wageningen UR
    ph - zuurgraad - meetinstrumenten - instrumenten (meters) - kalibratie - ph - acidity - indicating instruments - instruments - calibration
    Instructievideo over de kalibratie van de Schott pH meter
    Beehold : the colony of the honeybee (Apis mellifera L) as a bio-sampler for pollutants and plant pathogens
    Steen, J.J.M. van der - \ 2016
    Wageningen University. Promotor(en): Huub Rijnaarts, co-promotor(en): Tim Grotenhuis; Willem Jan de Kogel. - Wageningen : Wageningen University - ISBN 9789462577510 - 206
    apis mellifera - honey bees - honey bee colonies - biological indicators - sampling - instruments - pollution - pollutants - heavy metals - plant pathogenic bacteria - erwinia amylovora - erwinia pyrifoliae - analytical methods - apis mellifera - honingbijen - honingbijkolonies - biologische indicatoren - bemonsteren - instrumenten (meters) - verontreiniging - verontreinigende stoffen - zware metalen - plantenziekteverwekkende bacteriën - erwinia amylovora - erwinia pyrifoliae - analytische methoden

    Bio-sampling is a function of bio-indication. Bio-indication with honeybee colonies (Apis mellifera L) is where the research fields of environmental technology and apiculture overlap. The honeybees are samplers of the environment by collecting unintentionally and simultaneously, along with nectar, pollen, water and honeydew from the flowers or on the leaves, other matter (in bio-indication terms: target matter) and accumulating this in the colony. Collected target matter, in this thesis heavy metals, the plant pathogens Erwinia pyrifoliae and Erwinia amylovora and the soil pollutant γ-HCH, is collected from the colony by subsampling. Subsampling the honeybee colony is done by taking and killing bees from the hive (sacrificial) or by collecting target matter from the bee’s exterior without killing the bee (non-sacrificial). In environmental technology terms the application of the honeybee colony is a Passive Sampling Method (PSM). In this thesis the possibilities and restrictions of the PSM honeybee colony are explored.

    Bio-indication is a broad research field with one common factor: a living organism (bio) is applied to record an alteration of the environment (indication). The environment may be small such as a laboratory or big such as an ecosystem. Alterations in the organism may vary from detecting substances foreign to the body to mortality of the organism. In environmental technology the concept Source-Path-Receptor (SPR) is applied to map the route of a pollutant. It describes where in the environment the pollution is, how it moves through the environment and where it ends. This environment is the same environment of all living organisms, ergo also honeybees. Honeybees depend on flowers for their food. In the SPR concept, a flower can be a source, path or receptor. Along with collecting pollen, nectar, water and honeydew, target matter is collected by honeybees. Each honeybee functions as a micro-sampler of target matter in the environment, in this case the flower. Each honeybee is part of a honeybee colony and in fact the honeybee colony is the bio-sampler. The honeybee colony is a superorganism. The well-being of the colony prevails over the individual honeybee. Food collection is directed by the colony’s need. Foragers are directed to the most profitable food sources by the bee dance and food exchange (trophallaxis). The result of this feature is that mainly profitable sources are exploited and poor food sources less or not at all. During the active foraging period hundreds to thousands of flowers are visited daily. The nectar, pollen, water and honeydew plus the unintentionally collected target matter is accumulated in the honeybee colony. In order to obtain target matter the colony must be subsampled. This is done by picking bees from the hive-entrance (hive-entering bees) or inside the hive (in-hive bees) and processing them for analysis (sacrificial). This is the most commonly applied method. However, it is possible to subsample the colony without picking and processing the bees by collecting target matter from the hive-entering bee’s exterior (non-sacrificial). For non-sacrificial subsampling of the honeybee colony the Beehold device with the sampling part Beehold tube has been developed. The results of bio-indication with honeybee colonies are qualitative and indicative for follow up study (Chapter 1).

    Six bio-indication studies with honeybee colonies for bio-indication of heavy metals, the plant pathogens Erwinia pyrifoliae and Erwinia amylovora and the soil pollutant γ-HCH are presented. Chapter 2 describes how the concentration of eighteen heavy metals in honeybees fluctuate throughout the period of July, August and September (temporal) at the study sites: the city of Maastricht, the urban location with an electricity power plant in Buggenum and along the Nieuwe Waterweg at Hoek van Holland (spatial). A number of the metals have not been previously analysed in honeybees. To study whether honeybees can be used for bio-indication of air pollution, the concentrations of cadmium, vanadium and lead were compared to concentrations found in honeybees. The honeybee colonies were placed next to the air samplers. Only significant differences of metal concentrations in the ambient air also show in honeybees. This was the case with vanadium in ambient air and honeybees. The spatial and temporal differences of cadmium and lead were too futile to demonstrate a correspondence (Chapter 3). In a national surveillance study in 2008 the concentration of eighteen metals in honeybees has been analysed. The results showed a distinct regional pattern. Honeybees in the East of the Netherlands have higher concentrations of heavy metals compared to the bees in the West. Besides regional differences local differences were also recorded. An approximate description of the land use around 148 apiaries (> 50% agriculture, > 50% wooded area, > 50% urban area and mixed use) indicated the impact of land use on metal concentrations in honeybees. In areas with > 50% wood significantly higher concentrations of heavy metals were detected (Chapter 4). Subsampling of the honeybee colonies in Chapter 2, 3 and 4 was done sacrificially. In the studies presented in Chapter 5, 6, and 7 the honeybee colonies were subsampled non-sacrificially or simultaneously non-sacrificially and sacrificially. The plant pathogen E. pyrifoliae causes a flower infection in the strawberry cultivation in greenhouses. In greenhouse strawberry cultivation honeybees are applied for pollination. In Chapter 5 the combination pollination / bio-indication by honeybee colonies is studied. This proved to be a match. E. pyrifoliae could be detected on in-hive bees prior to any symptom of the infection in the flowers. In the Beehold tube, the bacterium was detected at the same time as the first tiny symptoms of the infection. In Chapter 5 the principles on which the Beehold tube is based are presented and discussed. The plant pathogen E. amylovora causes fireblight in orchards. The combination pollination / bio-indication has also been applied in this study performed in Austria in 2013. It is known that E. amylovora can be detected on honeybees prior to any symptom in the flower or on the fruit tree. A fireblight outbreak depends on flowering period, humidity and temperature. In 2013 no fireblight infection emerged in the orchards where the study was performed. Therefore, the bacterium could not be detected on the honeybees. γ-HCH (Lindane) is one of the soil pollutants in the Bitterfeld region in Saxony-Anhalt in Germany. It is the result of dumping industrial waste around the production locations. Although γ-HCH is bound to soil particles there is a flux to groundwater and surface water. Consequently, the pollution may end up in the sediments of the streambed and flood plains. The study objective was to investigate the hypothetic route of γ-HCH from polluted soil (source), via soil erosion and atmospheric deposition (route) to the receptor (flowering flowers) by detecting γ-HCH in the Beehold tube. Although on average over 17000 honeybees passed through the Beehold tube daily for a maximal period of 28 days, no γ-HCH has been detected. The pollen pattern in the Beehold tube revealed where the bees collected the food (Chapter 7).

    The application of the honeybee colony has pros and cons. Distinctive pros are many micro samplers, the extensive collection of matter (both food and target matter) and the accumulation in the colony. For successful bio-indication with honeybee colonies, determining factors are: the target matter, location of the target matter, distance between target matter and the honeybee colony, individual or pooled subsampling, the minimal sampling frequency and sample size, and sacrificial or non-sacrificial subsampling applied solely or in combination. Taking bees from a colony impacts upon the colony’s performance and consequently the passive sampling method. Based on a long-years’ experience and inter-collegial discussion it is stated that 3% of the forager bees (hive-entering) and 1.5% of the in-hive bees can be sampled safely without impacting upon the colony. This restriction does not apply when carrying out non-sacrificial subsampling of the honeybee colony (Chapter 8).

    Performing bio-indication with honeybee colonies has more applications than have been exploited so far. Further research can make a change. In particular I mention here the combination of pollination and bio-indication and the application of non-sacrificial subsampling solely or in combination with sacrificial subsampling.

    Everywhere Apiculture is practiced (all over the world except the polar areas) bio-indication with honeybee colonies can be applied in a simple, practical and low cost way.

    Origin authentication of distillers' dried grains and solubles (DDGS) - application and comparison of different analytical strategies
    Vermeulen, P. ; Nietner, T. ; Haughey, S.A. ; Yang, Z. ; Tena, N. ; Chmelarova, H. ; Ruth, S.M. van; Tomaniova, M. ; Boix, A. ; Han, L. ; Elliott, C.T. ; Baeten, V. ; Fauhl-Hassek, C. - \ 2015
    Analytical and Bioanalytical Chemistry 407 (2015)21. - ISSN 1618-2642 - p. 6447 - 6461.
    flight mass-spectrometry - geographical origin - calibration transfer - chemometric tools - fatty-acid - feed - transferability - instruments - food - ms
    In the context of products from certain regions or countries being banned because of an identified or non-identified hazard, proof of geographical origin is essential with regard to feed and food safety issues. Usually, the product labeling of an affected feed lot shows origin, and the paper documentation shows traceability. Incorrect product labeling is common in embargo situations, however, and alternative analytical strategies for controlling feed authenticity are therefore needed. In this study, distillers' dried grains and solubles (DDGS) were chosen as the product on which to base a comparison of analytical strategies aimed at identifying the most appropriate one. Various analytical techniques were investigated for their ability to authenticate DDGS, including spectroscopic and spectrometric techniques combined with multivariate data analysis, as well as proven techniques for authenticating food, such as DNA analysis and stable isotope ratio analysis. An external validation procedure (called the system challenge) was used to analyze sample sets blind and to compare analytical techniques. All the techniques were adapted so as to be applicable to the DDGS matrix. They produced positive results in determining the botanical origin of DDGS (corn vs. wheat), and several of them were able to determine the geographical origin of the DDGS in the sample set. The maintenance and extension of the databanks generated in this study through the analysis of new authentic samples from a single location are essential in order to monitor developments and processing that could affect authentication.
    'Geen appels met peren vergelijken' : tuinen bij Wageningen UR Glastuinbouw
    Strating, J. ; Vries, J.W. de; Kaashoek, B. - \ 2015
    Kas techniek 2015 (2015)3. - p. 44 - 45.
    glastuinbouw - kastechniek - sensors - instrumenten (meters) - controle - meting - normen - afwijkingen - gebreken - proeven op proefstations - greenhouse horticulture - greenhouse technology - sensors - instruments - control - measurement - standards - abnormalities - defects - station tests
    Telers zien de informatie die zij verkrijgen via hun sensoren doorgaans als de waarheid. Maar wat als de gebruikte sensoren in de kas een afwijking hebben en daardoor onjuiste informatie verstrekken? Vooral wanneer meerdere bedrijven of afdelingen in een proef worden vergeleken, kan dit tot verkeerde conclusies leiden, met alle gevolgen van dien.
    Waterbesparing door slimme en betaalbare sensor
    Balendonck, J. - \ 2015
    Kas techniek 2015 (2015)april. - p. 34 - 37.
    teelt onder bescherming - cultuurmethoden - kunststoftunnels - irrigatie - sensors - instrumenten (meters) - waterbehoefte - vochtmeters - watergebruik - efficiëntie - watergebruiksrendement - irrigatiesystemen - protected cultivation - cultural methods - plastic tunnels - irrigation - sensors - instruments - water requirements - moisture meters - water use - efficiency - water use efficiency - irrigation systems
    Onderzoekers van Wageningen UR Glastuinbouw hebben in het kader van een Partners voor Water-project laten zien dat Turkse telers met behulp van de AquaTag veel efficiënter kunnen irrigeren. Sturen op vochtsensoren is niet nieuw, maar beschikbare sensoren zijn relatief duur en meten alleen lokaal, terwijl het vochtgehalte sterk kan variëren binnen een kraanvak. Met de AquaTag is nu een goedkope en slimme oplossing voor handen.
    Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses
    Cambra-Lopez, M. ; Winkel, A. ; Mosquera Losada, J. ; Ogink, N.W.M. ; Aarnink, A.J.A. - \ 2015
    Atmospheric Environment 111 (2015). - ISSN 1352-2310 - p. 20 - 27.
    particulate matter - aerosol monitors - indoor - dust - instruments - emissions - devices - pm2.5 - teom
    The objective of this study was to compare co-located real-time light scattering devices and equivalent gravimetric samplers in poultry and pig houses for PM10 mass concentration, and to develop animal-specific calibration factors for light scattering samplers. These results will contribute to evaluate the comparability of different sampling instruments for PM10 concentrations. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside animal houses. Sampling was conducted in 32 animal houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. Deviations between samplers were calculated and discussed. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg m-3 and a correlation coefficient of 0.91 (excluding turkeys). Results in turkeys showed a regression coefficient equal to 1.1 (P = 0.49), an intercept of 0.06 mg m-3 (P <0.0001) and a correlation coefficient of 0.98. In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg m-3 and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in both poultry and pig housing systems compared with cyclone pre-separators. Absolute, relative, and random deviations increased with concentration. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in animal houses. We recommend linear regression equations as animal-specific calibration factors for DustTraks instead of manufacturer calibration factors, especially in heavily dusty environments such as animal houses
    Proeven werpen nieuw licht op meten fotosynthese
    Reinders, U. ; Dieleman, J.A. - \ 2015
    Kas techniek 2015 (2015)april. - p. 28 - 29, 31.
    glastuinbouw - kastechniek - proeven - meting - fotosynthese - licht - instrumenten (meters) - gewasmonitoring - greenhouse horticulture - greenhouse technology - trials - measurement - photosynthesis - light - instruments - crop monitoring
    In recente projecten, gefinancierd door Kas als Energiebron, zijn drie systemen onderzocht waarmee de fotosynthese van planten kan worden bepaald. Ze werden gebruikt om efficiëntie van het gebruik van licht voor de fotosynthese te meten. De systemen op basis van ETR-meting functioneerden goed. Voor het gewasmonitoringssysteem bleek de praktijk nog weerbarstig.
    The dictator effect: how long years in office affect economic development
    Papaioannou, K.I. ; Zanden, J.L. van - \ 2015
    Journal of Institutional Economics 11 (2015)1. - ISSN 1744-1374 - p. 111 - 139.
    panel-data - measuring democracy - government size - cross-section - cause growth - institutions - power - democratization - instruments - countries
    This paper contributes to the growing literature on the links between political regimes and economic development by studying the effects of years in office on economic development. The hypothesis is that dictators who stay in office for a long time period will find it increasingly difficult to carry out sound economic policies. We argue that such economic policies are the result of information asymmetries inherent to dictatorships (known as the ‘dictator dilemma’) and of changes in the personality of dictators (known as the ‘winner effect’). We call the combination of these two terms the ‘dictator effect’. We present evidence to suggest that long years in office impacts on economic growth (which is reduced), inflation (which increases) and the quality of institutions (which deteriorates). The negative effect of long years of tenure (i.e. the ‘dictator effect’) is particularly strong in young states and in Africa and the Near East.
    Watergift en emissie "De lysimeter en vochtsensoren"
    Helm, Frank van der - \ 2014
    greenhouse horticulture - cropping systems - lysimeters - irrigation water - sensors - instruments - monitoring - emission
    Project emissiemanagement implementatie 'de lysimeter en vochtsensoren' : stand van zaken
    Voogt, Wim - \ 2014
    greenhouse horticulture - cropping systems - lysimeters - sensors - emission - irrigation water - instruments - models - greenhouse crops
    De emissiemanagement-tool : vochtsensoren
    Balendonck, Jos - \ 2014
    greenhouse horticulture - sensors - lysimeters - cropping systems - instruments - irrigation water - decision making - control
    Watergift en emissie bij alstroemeria, toepassing lysimeter en vochtsensoren
    Voogt, Wim - \ 2014
    greenhouse horticulture - alstroemeria - cultural methods - sensors - lysimeters - instruments - irrigation water - emission
    Use of Two-Part Regression Calibration Model to Correct for Measurement Error in Episodically Consumed Foods in a Single-Replicate Study Design: EPIC Case Study
    Agogo, G.O. ; Voet, H. van der; Veer, P. van 't; Ferrari, P. ; Leenders, M. ; Muller, D.C. ; Sánchez-Cantalejo, E. ; Bamia, C. ; Braaten, T. ; Knüppel, S. ; Johansson, I. ; Eeuwijk, F.A. van; Boshuizen, H.C. - \ 2014
    PLoS ONE 9 (2014)11. - ISSN 1932-6203 - 15 p.
    dietary self-report - nutrition - cancer - instruments - outcomes - disease - markers
    In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.
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