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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Accounting for ecosystem assets using remote sensing in the Colombian Orinoco River Basin lowlands
Vargas Barbosa, Leonardo ; Hein, Lars ; Remme, Roy P. - \ 2017
Journal of Applied Remote Sensing 11 (2017)2. - ISSN 1931-3195
condition - ecosystem services - measurement - moderate resolution imaging spectroradiometer - net primary productivity

Worldwide, ecosystem change compromises the supply of ecosystem services (ES). Better managing ecosystems requires detailed information on these changes and their implications for ES supply. Ecosystem accounting has been developed as an environmental-economic accounting system using concepts aligned with the System of National Accounts. Ecosystem accounting requires spatial information from a local to national scale. The objective of this paper is to explore how remote sensing can be used to analyze ecosystems using an accounting approach in the Orinoco River Basin. We assessed ecosystem assets in terms of extent, condition, and capacity to supply ES. We focus on four specific ES: grasslands grazed by cattle, timber harvesting, oil palm fresh fruit bunches harvesting, and carbon sequestration. We link ES with six ecosystem assets: savannahs, woody grasslands, mixed agroecosystems, very dense forests, dense forest, and oil palm plantations. We used remote sensing vegetation and productivity indexes to measure ecosystem assets. We found that remote sensing is a powerful tool to estimate ecosystem extent. The enhanced vegetation index can be used to assess ecosystems condition, and net primary productivity can be used for the assessment of ecosystem assets capacity to supply ES. Integrating remote sensing and ecological information facilitates efficient monitoring of ecosystem assets.

How to measure health improvement? : assessment of subtle shifts in metabolic phenotype
Fazelzadeh, Parastoo - \ 2017
University. Promotor(en): Sander Kersten; John van Duynhoven, co-promotor(en): Mark Boekschoten. - Wageningen : Wageningen University - ISBN 9789463430739 - 187
health promotion - improvement - measurement - metabolic profiling - elderly - obesity - microarrays - rna - peripheral blood mononuclear cells - gezondheidsbevordering - verbetering - meting - metabolische profilering - ouderen - obesitas - perifere mononucleaire bloedcellen

Human health is impacted by a complex network of interactions between biological pathways, mechanisms, processes, and organs, which need to be able to adapt to a continuously changing environment to maintain health. This adaptive ability is called ‘phenotypic flexibility’. It is thought that health is compromised and diseases develop when these adaptive processes fail. As the product of interactions between several factors such as genetic makeup, diet, lifestyle, environment and the gut microbiome, the ‘metabolic phenotype’ provides a readout of the metabolic state of an individual. Understanding these relationships will be one of a major challenges in nutrition and health research in the next decades. To address this challenge, the development of high-throughput omics tools combined with the application of elaborate statistical analyses will help characterize the complex relationship of (bio) chemicals in human systems and their interaction with other variables including environment and lifestyle to produce the measured phenotype. An important aim of this thesis was to identify phenotype shifts by looking at effect of prolonged resistance-type exercise training on skeletal muscle tissue in older subjects and the possible shift toward the features of younger subjects as a reference for a healthier phenotype. A second aim was to identify phenotype shifts by looking at the response to a challenge in obese subjects and the possible shift toward lean subjects as a reference for a healthier phenotype.

Chapter 2 and 3 of this thesis show how the significant remaining plasticity of ageing skeletal muscle can adapt to resistance-type exercise training. The data indicate that frail and healthy older subjects have two distinct phenotypes according to the skeletal muscle tissue metabolite profiles and that exercise training shifts aged muscle towards a younger phenotype. We showed that the effect of exercise on amino acid derived acylcarnitines (AAAC’s) in older subjects points towards decreased branched chain amino acid catabolism, likely due to compromised activation of the branched chain α-keto acid hydrogenase (BCKDH) complex. Furthermore, we found that the protocadherin gamma gene cluster might be involved in aged-muscle denervation and re-innervation. Finally, plasma was found to be a poor indicator of muscle metabolism, emphasizing the need for direct assessment of metabolites in muscle tissue.

Chapter 4 of this thesis examines whether a mixed meal challenge response provides a readout for a shift in phenotype upon weight loss in obese male subjects. We concluded that weight loss moderately affects the mixed meal challenge response of both plasma metabolome and transcriptome of peripheral blood mononuclear cells in obese subjects. Measurements at the fasted and postprandial state also provide us with a different type of information.

In Chapter 5 it is demonstrated that the global testing of pathways could provide a concise summary of the multiple univariate testing approach used in Chapter 4. In Chapter 6 it is discussed how the findings of this thesis increase our understanding of how to measure phenotypic flexibility as a proxy of health. In this thesis it is shown that the correlations between tissue and plasma metabolites are rather weak, emphasising the need to perform organ-specific studies. Availability of less invasive/painful sampling techniques and the use of small amounts of tissue would enable larger scale human studies on adipose tissue and skeletal muscle to more accurately define phenotypical shifts due to diet or lifestyle interventions. With respect to the assessment of phenotypical flexibility by omics approaches, significant complications can be expected in trying to relate plasma metabolism to PBMC gene expression. Organ-focussed approaches that integrate multiple omics levels using system biology approaches are considered to be a lot more promising.

Two and a half years of country-wide rainfall maps using radio links from commercial cellular telecommunication networks
Overeem, A. ; Leijnse, H. ; Uijlenhoet, R. - \ 2016
Water Resources Research 52 (2016)10. - ISSN 0043-1397 - p. 8039 - 8065.
measurement - microwave links - precipitation - remote sensing

Although rainfall estimation employing microwave links from cellular telecommunication networks is recognized as a new promising measurement technique, its potential for long-term large-scale operational rainfall monitoring remains to be demonstrated. This study contributes to this endeavor by deriving a continuous series of rainfall maps from a large 2.5 year microwave link data set of, on average, 3383 links (2044 link paths) covering Netherlands (∼3.5 × 104 km2), a midlatitude country (∼5°E, ∼52°N) with a temperate climate. Maps are extensively verified against an independent gauge-adjusted radar rainfall data set for different temporal (15 min, 1 h, 1 day, 1 month) and spatial (0.9, 74 km2) scales. The usefulness of different steps in the rainfall retrieval algorithm, i.e., a wet-dry classification method and a filter to remove outliers, is systematically assessed. A novel dew filter is developed to correct for dew-induced wet antenna attenuation, which, although a relative underestimation of 6% to 9% is found, generally yields good results. The microwave link rainfall estimation technique performs well for the summer months (June, July, August), even outperforming interpolation of automatic rain gauge data (with a density of ∼1 gauge per 1000 km2), but large deviations are found for the winter months (December, January, February). These deviations are generally expected to be related to frozen or melting precipitation. Hence, our results show the potential of commercial microwave links for long-term large-scale operational rainfall monitoring.

Robot meet fotosynthese
Aarts, Mark ; Harbinson, Jeremy - \ 2016
photosynthesis - robots - measurement - agricultural research - plant breeding - genetics
Met goedgekeurde installatie kan teler voldoen aan wet op lozingen : markt voor zuiveringstechnieken is in beweging
Ruijven, Jim van - \ 2016
horticulture - greenhouse horticulture - water management - water treatment - measurement - purification plants - testing - drainage water - legislation - netherlands - agricultural research

Vanaf 1 januari 2018 moet elk glastuinbouwbedrijf een apparaat gebruiken dat 95% van de gewasbeschermingsmiddelen uit het lozingswater zuivert. Hoe gaat de overheid dat controleren? Dat gebeurt via de leverancier van de installatie. Als die aantoont dat zijn techniek dat voor elkaar krijgt, komt deze op een positieve lijst. Maakt de ondernemer op de juiste manier gebruik van zo’n goedgekeurde installatie, dan voldoet hij aan de wet.

Grasgroei meten met de grashoogtemeter
Holshof, G. ; Stienezen, M.W.J. - \ 2016
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 925) - 23 p.
grassen - groei - meting - opbrengsten - graslandbeheer - grasses - growth - measurement - yields - grassland management
Inzicht en Zichtbaar Weerbaar: meetmethoden nodig voor teelt-zeker weerbaar telen
Wurff, A.W.G. van der; Streminska, M.A. ; Boer, F.A. de; Cuesta Arenas, Y. ; Janse, J. - \ 2015
Wageningen UR
cropping systems - horticulture - plant protection - hydroponics - greenhouse horticulture - conferences - chrysanthemum - soilless culture - substrates - measurement - interactions - markers - plant development - climate - cultivars - tuinbouw - glastuinbouw - teeltsystemen - cultuur zonder grond - substraten - meting - interacties - merkers - plantenontwikkeling - klimaat
Aandacht wordt geschonken aan: voedingswater, micro-leven, rasverschillen, en oud stekmateriaal. Poster van PlantgezondheidEvent 12 maart 2015.
Evaluatie van methaanemissieberekeningen en -metingen in de veehouderij
Groenestein, C.M. ; Mosquera Losada, J. - \ 2015
Wettelijke Onderzoekstaken Natuur & Milieu (WOt-technical report 54) - 46 p.
veehouderij - mest - methaan - emissie - meting - berekening - varkens - livestock farming - manures - methane - emission - measurement - calculation - pigs
Wageningen UR Livestock Research heeft een deskstudie uitgevoerd om te analyseren waarom berekende en
gemeten methaanemissies verschillen en doet aanbevelingen voor nader onderzoek. Het blijkt dat zowel aan
de kant van de meetwaarden als aan de kant van de berekeningen vragen kunnen worden gesteld. De
aanbevelingen betreffen een nadere beschouwing van mestsamenstelling (met name organische stof (OS),
de fractie van de organische stof die afbreekbaar is (Bo) en het deel van de afbreekbare fractie die
daadwerkelijk wordt afgebroken tot CH4 (MCF)) met in achtneming van Nederlandse omstandigheden.
Tevens wordt geadviseerd te bestuderen wat de oorzaak kan zijn van de grote variatie in gemeten
methaanemissie met oog voor de leeftijd van de mest, effect van ammoniakemissie-reducerende
maatregelen, mestmanagement en enterische methaanemissie door varkens
OM 2.0
Rijgersberg, H. ; Wigham, M.L.I. ; Willems, D.J.M. ; Top, J.L. - \ 2015
Wageningen : Wageningen UR - Food & Biobased Research (Report / Wageningen UR Food & Biobased Research 1596) - ISBN 9789462575264 - 9
ontologieën - eenheden - meting - gegevensbeheer - computer software - informatiesystemen - ontologies - units - measurement - data management - information systems
Systematische fouten in metingen van grondwaterstanden met drukopnemers : verslag van een data-analyse
Pleijter, M. ; Hamersveld, L. ; Knotters, M. - \ 2015
Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2666) - 23
grondwaterstand - grondwater - fouten - meting - gegevensanalyse - groundwater level - groundwater - errors - measurement - data analysis
Handmetingen zijn onmisbaar bij het gebruik van automatische grondwaterstandopnemers om meetfouten te kunnen opsporen. Wij onderzochten de verschillen tussen handmetingen van de grondwaterstand en metingen uitgevoerd met drukopnemers. Hierbij analyseerden we van 474 locaties meetreeksen van ca. twee jaar lang. We keken of de opgetreden verschillen systematisch zijn en of er trends te ontdekken zijn die duiden op drift van het nulpunt van de drukopnemers. Bij 144 locaties (30%) is een significante lineaire toename van de verschilwaarden aangetoond, die zowel positief als negatief kan zijn. Een algemeen verloop van de verschilwaarden kon niet worden aangetoond. Voor metingen van individuele drukopnemers bevelen we aan om, als de verschillen binnen twee jaar oplopen tot meer dan 2 cm, de metingen van de drukopnemer met behulp van een lineair regressiemodel aan te passen aan de handmetingen. We bevelen aan om ten minste vier handmetingen per jaar te verrichten en om eenmaal per twee jaar een eventuele correctie uit te voeren. Deze handmeting moet in het veld worden gecontroleerd met de gecompenseerde meting van de drukopnemer. Hierdoor wordt de kans op het maken van een fout in de handmeting verkleind.
Water geven naar behoefte komt stapje dichterbij : Het mysterie van de verdwenen stikstof
Kierkels, T. ; Voogt, W. - \ 2015
Onder Glas 12 (2015)5. - p. 20 - 21.
glastuinbouw - potplanten - plantenvoeding - nutriëntenuitspoeling - stikstof - irrigatie - meting - voedingsstoffenbalans - sensors - vochtmeters - waterbehoefte - greenhouse horticulture - pot plants - plant nutrition - nutrient leaching - nitrogen - irrigation - measurement - nutrient balance - moisture meters - water requirements
De variatie in uitspoeling van mineralen is groot tussen verschillende chrysantenbedrijven. Voor een deel ligt dat aan ondernemersbeslissingen. Om goed te kunnen sturen op minimale uitspoeling en maximale productkwaliteit zijn goede tools nodig. Een betere vochtsensor is zeer welkom, geeft teler Jos Ammerlaan aan.
Hiep hiep hulpsel!
Kleis, R. ; Dijksma, R. - \ 2015
Resource: weekblad voor Wageningen UR 10 (2015)4. - ISSN 1874-3625 - p. 12 - 13.
hydrologie - waterlopen - achterhoek - studenten - meting - universitair onderzoek - stroomgebieden - hydrology - streams - students - measurement - university research - watersheds
Diep in de Achterhoek ligt een van de best bemeten en begrepen beken van de wereld. Al vijftig jaar zijn Wageningse wetenschappers en studenten hier kind aan huis.
Metingen aan het windveld van een ventilator van een kippenstal
Pronk, A.A. ; Holterman, H.J. ; Meurs, E.J.J. ; Geerts, R.H.E.M. - \ 2015
Wageningen : Plant Research International, Business Unit Agrosysteemkunde (Rapport / Plant Research International 612) - 28
huisvesting van kippen - stallen - ventilatoren - meting - pluimveehouderij - emissie - luchtkwaliteit - fijn stof - ammoniakemissie - chicken housing - stalls - ventilators - measurement - poultry farming - emission - air quality - particulate matter - ammonia emission
Dust, both coarse and fine (PM10), is emitted mainly through the exhaust fans of livestock housing and especially through the exhaust fans of poultry housing. There is little known about the dispersion of the emission plume of an exhaust fans of funnel ventilation systems at a short distance of the housing (30 to 40 m). It is known that a hedgerow has a profound effect on an emission plume as both wind speed and wind direction are affected. However, up till now it is not clear how an emission plume is changed.
Aromameter onthult smaakverlies groente en fruit
Woltering, E.J. - \ 2015
WageningenWorld (2015)2. - ISSN 2210-7908 - p. 5 - 5.
groenten - fruit - smaak - bemonsteren - meting - apparatuur - innovaties - houdbaarheid (kwaliteit) - reductie - aroma - verandering - vegetables - taste - sampling - measurement - apparatus - innovations - keeping quality - reduction - change
Een tomaat in de koelkast verliest al snel onomkeerbaar zijn smaak. Dat blijkt uit metingen met een nieuw apparaat, ontwikkeld door Wageningen UR. Dat kan snel en nauwkeurig veranderingen in het aroma vaststellen.
'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 - 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.
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.
Eindrapportage implementatie welzijnsmonitor vleeskuikens : rapportage voor deelnemende vleeskuikenhouders, slachterijen en dierenartspraktijken/
Jong, I.C. de; Gunnink, H. ; Hindle, V.A. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 840) - 33
dierenwelzijn - vleeskuikens - pluimveehouderij - monitoring - diergezondheid - meting - protocollen - voetzolen - laesies - huisvesting van kippen - animal welfare - broilers - poultry farming - animal health - measurement - protocols - footpads - lesions - chicken housing
In this report the results of the project ‘Implementation of the broiler welfare assessment protocol’ are summarised and presented for the participating broiler farmers, slaughter plants and veterinarians. The following topics are discussed: validity and feasibility of measures, which measures need to be improved; possibility for simplification of the assessment protocol (reduction of assessment time); management changes and the effects: is the assessment protocol suitable to support farmers’ management?; feedback from the participants.
Praktijkproef LED Alstroemeria : invloed licht spectrum op bladkwaliteit : bouwstenen voor energiebesparing
Garcia, N. ; Helm, F.P.M. van der; Warmenhoven, M.G. - \ 2015
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1337) - 48
glastuinbouw - cultuurmethoden - teelt onder bescherming - alstroemeria - belichting - led lampen - meting - fotosynthese - gewasanalyse - temperatuur - energiebesparing - greenhouse horticulture - cultural methods - protected cultivation - illumination - led lamps - measurement - photosynthesis - plant analysis - temperature - energy saving
Energy efficient cultivation of Alstroemeria requires more than just saving on heat. The total energy demand could be reduced by 40% if saving on lighting is possible. LED lighting can save 20% thanks to the higher efficiency of lamp and installation. If the morphology and quality of the foliage can be improved by manipulating the spectrum of the artificial light, then light interception and photosynthesis efficiency could improve too. The test at a commercial farm in winter 2013/2014 showed that plants grown under the conventional High Pressure Sodium lamps or under LED lamps (spectrum Valoya R300 AP67) did not differ in production and quality; this gives opportunities for energy savings with LED. The spectrum of Valoya R300 AP67 gave a slightly higher conductance of stomata and a higher photosynthesis was measured immediately after the dark period. However, this did not result in a higher production, more flowers or greener leaves, but it lead to a modest reduction in the number of necrotic leaf tips. The photosynthesis measurements suggest that low leaf temperatures in combination with long artificial light period may negatively influence leaf quality. A test with better insulation (transparent second screen) combined with dehumidification and shorter light period is therefore recommended.
Measuring crosswind using scintillometry
Dinther, D. van - \ 2015
University. Promotor(en): Bert Holtslag, co-promotor(en): Oscar Hartogensis. - Wageningen : Wageningen University - ISBN 9789462571815 - 161
scintillometrie - meteorologische waarnemingen - wind - methodologie - meting - scintillometry - meteorological observations - methodology - measurement

This thesis demonstrates that a scintillometer is able to obtain a path-averaged value of the crosswind (i.e., wind component perpendicular to a path). A scintillometer consists of a transmitter and a receiver spaced a few hundred meters to a few kilometres apart. The transmitter emits light with a certain wavelength, which is refracted by scintillations in the atmosphere (eddies with a different temperature and moisture content than their surrounding). The atmosphere is turbulent, thus the receiver of the scintillometer measures the intensity of the fluctuations of the light. Two scintillometer setup next to each other in principle measure the same eddy field except for a time-shift. It is known that this time-shift is linked to the crosswind: the lower the time shift the stronger the crosswind. This thesis shows that experimental calibration in the field to measure the crosswind with a scintillometer is not necessary. Also we developed two new algorithms, which are able to obtain the crosswind from the scintillometer signal. First, the algorithms were validated with measurements made above a flat grassland field. Later, measurements took place over more complex terrains (i) above the city of Helsinki, Finland and (ii) next to a runway at Schiphol airport, the Netherlands. We highlight that even in these complex terrains the scintillometer was able to obtain the crosswind correctly. At Schiphol airport also other applications of scintillometry were investigated: visibility measurements, and wake vortex detection. To use scintillometers as a visibility sensor, more research is necessary. In contrast, the scintillometer proved to be able to detect wake vortices created by airplanes during the night, when the atmospheric turbulence is low.

Grondwaterstand handmatig meten blijkt best nauwkeurig
Knotters, M. ; Meij, T. de; Pleijter, M. - \ 2014
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 47 (2014)1. - ISSN 0166-8439 - p. 28 - 28.
grondwaterstand - nauwkeurigheid - meting - experimenteel veldonderzoek - overijssel - groundwater level - accuracy - measurement - field experimentation
Het valt reuze mee met de nauwkeurigheid van handmatig gemeten grondwaterstanden. Wie de grondwaterstand op een zeer traditionele manier meet (via meetlint in de peilbuis) of met een elektronisch peilapparaat met geluidssignaal, maakt meetfouten van hooguit enkele centimeters. Een experiment bij het Boetelerveld wijst dat uit.
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