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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Data from: Below-ground resource partitioning alone cannot explain the biodiversity–ecosystem function relationship: a field test using multiple tracers
Jesch, Annette ; Barry, Kathryn E. ; Ravenek, Janneke M. ; Bachmann, Dörte ; Strecker, Tanja ; Weigelt, Alexandra ; Buchmann, Nina ; Kroon, Hans de; Gessler, Arthur ; Mommer, L. ; Roscher, Christiane ; Scherer-Lorenzen, Michael - \ 2018
ecosystem function and services - Jena Experiment - Levins B - resource uptake - water uptake - stable isotopes - rare element tracers - complementarity - proportional similarity
Contrasting the roles of section length and instream habitat enhancement for river restoration success: a field study on 20 European restoration projects
Hering, D. ; Aroviita, J. ; Baattrup-Pedersen, A. ; Brabec, K. ; Buijse, T. ; Ecke, F. ; Friberg, N. ; Gielczewski, Marek ; Januschke, K. ; Köhler, J. ; Kupilas, Benjamin ; Lorenz, A.W. ; Muhar, S. ; Paillex, Amael ; Poppe, Michaela ; Schmidt, T. ; Schmutz, S. ; Vermaat, J. ; Verdonschot, R.C.M. ; Verdonschot, P.F.M. ; Wolter, Christian ; Kail, J. - \ 2015
aquatic macrophytes - benthic invertebrates - fish - floodplain - flow patterns - food web - ground beetles - riparian vegetation - stable isotopes
1. Restoration of river hydromorphology often has limited detected effects on river biota. One frequently discussed reason is that the restored river length is insufficient to allow populations to develop and give the room for geomorphologic processes to occur. 2. We investigated ten pairs of restored river sections of which one was a large project involving a long, intensively restored river section and one represented a smaller restoration effort. The restoration effect was quantified by comparing each restored river section to an upstream non-restored section. We sampled the following response variables: habitat composition in the river and its floodplain, three aquatic organism groups (aquatic macrophytes, benthic invertebrates and fish), two floodplain-inhabiting organism groups (floodplain vegetation, ground beetles), as well as food web composition and land–water interactions reflected by stable isotopes. 3. For each response variable, we compared the difference in dissimilarity of the restored and nearby non-restored section between the larger and the smaller restoration projects. In a second step, we regrouped the pairs and compared restored sections with large changes in substrate composition to those with small changes. 4. When comparing all restored to all non-restored sections, ground beetles were most strongly responding to restoration, followed by fish, floodplain vegetation, benthic invertebrates and aquatic macrophytes. Aquatic habitats and stable isotope signatures responded less strongly. 5. When grouping the restored sections by project size, there was no difference in the response to restoration between the projects targeting long and short river sections with regard to any of the measured response variables except nitrogen isotopic composition. In contrast, when grouping the restored sections by substrate composition, the responses of fish, benthic invertebrates, aquatic macrophytes, floodplain vegetation and nitrogen isotopic composition were greater in sections with larger changes in substrate composition as compared to those with smaller changes. 6. Synthesis and applications. The effects of hydromorphological restoration measures on aquatic and floodplain biota strongly depend on the creation of habitat for aquatic organisms, which were limited or not present prior to restoration. These positive effects on habitats are not necessarily related to the restored river length. Therefore, we recommend a focus on habitat enhancement in river restoration projects.
Indirect calorimetry during incubation of hatching eggs
Brand, H. van den; Heetkamp, M.J.W. ; Kemp, B. - \ 2015
In: Indirect Calorimetry : Techniques, computations and applications / W.J.J., Gerrits, E., Labussière, Wageningen : Wageningen Academic Publishers - ISBN 9789086862610 - p. 231 - 246.
chickens - stable isotopes - oxygen - carbon dioxide - eggshell temperature
Indirect calorimetry can be used during incubation of avian eggs to monitor the quality of the incubation process, the development of the embryo and the utilization of nutrients. Indirect calorimetry has several benefits above direct calorimetry, particularly in hatching eggs. However, to obtain reliable measurements, some aspects of indirect calorimetry need to be taken into account. First, some attention is given to the use of respiration chambers for only one single egg or more eggs at the same time, with the advantages and disadvantages. Furthermore, attention is paid to the importance of using embryo or eggshell temperature as a tool to adjust the temperature in the respiration chamber. Since there is a strong relationship between embryo temperature and heat production (Q), the incubator temperature should be controlled depending on the desired eggshell temperature. Additionally, it is important to consider oxygen and carbon dioxide levels in the chamber, as low partial O2 pressure is related to incubation at high altitude and high CO2 levels can result from insufficient ventilation. Besides abiotic factors affecting Q, such as temperature, biotic factors, like egg weight and age of the breeder, affect Q as well. Finally, the use of stable isotopes during incubation to determine oxidation of different nutrients during the incubation process will be addressed. We conclude that indirect calorimetry during incubation of hatching eggs can give insight in the development of the embryo and the utilization of egg nutrients throughout incubation. However, to prevent misinterpretation of the results, some incubation factors (like temperature, O2 and CO2 concentration) and egg characteristics (like weight, breed and breeder age) need to be monitored and controlled.
How much bio is in there? Can stable isotopes be used to determine the bio-based content of products?
Broek, L.A.M. van den; Veer, G. van der; Zee, M. van der - \ 2015
Bioplastics Magazine 10 (2015)5. - ISSN 1862-5258 - p. 18 - 22.
isotopen - stabiele isotopen - biobased economy - materialen uit biologische grondstoffen - samenstelling - analytische methoden - isotopes - stable isotopes - biobased materials - composition - analytical methods
Can stable isotopes be used to determine the bio-based content of products?
Passage of feed in dairy cows : use of stable isotopes to estimate passage kinetics through the digestive tract of dairy cows
Warner, D. - \ 2013
Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Wilbert Pellikaan; Jan Dijkstra. - S.l. : s.n. - ISBN 9789461736833 - 163
melkkoeien - melkvee - voer - voedingsstoffen - spijsvertering - spijsverteringskanaal - kinetica - stabiele isotopen - verteerbaarheidsmerkers - rundveevoeding - diervoeding - voedingsfysiologie - dairy cows - dairy cattle - feeds - nutrients - digestion - digestive tract - kinetics - stable isotopes - digestibility markers - cattle feeding - animal nutrition - nutrition physiology

Dairy cows possess a unique digestive system to digest fibre-rich diets. Ingested feed is retained and degraded in the rumen by the enteric microbial population and is passed from the rumen to the following segments of the digestive tract. Passage of feed determines energy and protein supply to the animal and is a key parameter in several feed evaluation models for ruminants. Yet, quantitative data on passage of feed and particularly of single feed components are limited. Common techniques used to determine fractional passage rates of feed typically include indigestible markers that are not able to describe passage of distinct feed components. This thesis describes the use of stable isotope labelled feed components as a novel marker to determine feed type and feed component specific fractional passage rates. In a series of in vivoexperiments, fractional passage rates of a typical dairy ration, including grass silage, maize silage and concentrates, were determined. The use of carbon (13C) and nitrogen (15N) stable isotopes as an internal marker inherent to the diet allowed to specifically determine fractional passage rates of plant cell walls such as structural fibre, fibre-bound nitrogen, n-alkanes, and intracellular components such as starch and total nitrogen. For grass silage and maize silage, stable isotopes gave slower fractional rumen passage rates compared to the commonly used external marker chromium mordanted fibre; for concentrates, stable isotopes gave faster rates than the external marker. Among isotopic labelled fractions, 13C-labelled fibre and 15N-labelled fibre-bound nitrogen gave the slowest rates. The isotopic signature of single feed components and further application of stable isotopes on a wider range of feeds and feed components offers scope for the future for a more detailed insight into nutrient-specific passage kinetics. This will ultimately allow to quantify nutrient supply in response to changes in diet composition and quality, and model animal response in relation to optimal animal performance, environmental and animal-health issues.

Letter: Variable and complex food web structures revealed by exploring missing trophic links between birds and biofilm
Kuwae, T. ; Miyoshi, E. ; Hosokawa, S. ; Amano, T. ; Moriya, T. ; Kondoh, M. ; Ydenberg, R.C. ; Elner, R.W. - \ 2012
Ecology Letters 15 (2012)4. - ISSN 1461-023X - p. 347 - 356.
knots calidris-canutus - western sandpipers - ecological networks - stable isotopes - dunlin - stability - dynamics - mauri - size - populations
Food webs are comprised of a network of trophic interactions and are essential to elucidating ecosystem processes and functions. However, the presence of unknown, but critical networks hampers understanding of complex and dynamic food webs in nature. Here, we empirically demonstrate a missing link, both critical and variable, by revealing that direct predator-prey relationships between shorebirds and biofilm are widespread and mediated by multiple ecological and evolutionary determinants. Food source mixing models and energy budget estimates indicate that the strength of the missing linkage is dependent on predator traits (body mass and foraging action rate) and the environment that determines food density. Morphological analyses, showing that smaller bodied species possess more developed feeding apparatus to consume biofilm, suggest that the linkage is also phylogenetically dependent and affords a compelling re-interpretation of niche differentiation. We contend that exploring missing links is a necessity for revealing true network structure and dynamics.
Speuren in het allerkleinste (interview met Grishja van der Veer)
Veer, Grishja van der - \ 2012
stable isotopes - forensic science - authenticity - analytical methods - food analysis - isotopes
Reproductive biology and induced sterility as determinants for genetic control of mosquitoes with the Sterile Insect Technique
Helinski, M. - \ 2008
Wageningen University. Promotor(en): Marcel Dicke, co-promotor(en): B.G.J. Knols. - S.l. : S.n. - ISBN 9789085049555 - 203
steriele insecten techniek - genetische gewasbescherming - sterilisatie - ioniserende straling - stabiele isotopen - ziekten overgebracht door muskieten - malaria - anopheles arabiensis - paarconcurrentie - sudan - sterile insect release - genetic control - sterilization - ionizing radiation - stable isotopes - mosquito-borne diseases - mating competitiveness
Malaria remains an important health issue in sub-Saharan Africa, and new methods to reduce the disease are needed. In this thesis, the use of the Sterile Insect Technique (SIT) against the African malaria vector Anopheles arabiensis was explored. The SIT relies on the releases of large numbers of sterilised males. If the sterile males are successful in competing for mates and the females use their sperm for fertilisation, the wild population is reduced. Ultimately, this can lead to a reduction in disease incidence. Sterilisation of the sperm cells occurs by ionising radiation, resulting in the death of the developing embryo after fertilisation. Somatic cells are also damaged, which can lead to a reduced mating competitiveness of the males.
In this thesis I investigated 1) the relationship between dose and induced sterility for pupal or adult stage irradiation, 2) sperm quantity and sperm length polymorphism and the influence of irradiation, 3) the use of stable isotopes to determine mating in mosquitoes, 4) the incidence of multiple mating in relation to irradiation, 5) the fitness of irradiated males in terms of survival and mating competitiveness, and 6) the use of a field cage for mating studies, and the small-scale feasibility of the SIT in Sudan.
Results showed that even though the dose-response curves between dose and induced sterility were largely similar for pupae and adults, irradiation of adults resulted in a better competitiveness compared to pupal irradiation. A negative relationship between dose and competitiveness was observed for pupal stage irradiation. In addition, radiation during the pupal stage affected the number of spermatozoa in the testes and the distribution of sperm lengths, but no impact on the incidence of multiple mating could be observed. Stable isotopes were used successfully to determine paternity in mating. Mating competitiveness of males irradiated as pupae could be improved by a three-fold increase in their number compared to un-irradiated males, but only for the partially-sterilising dose. The small-scale irradiation and transportation of insects in Sudan was feasible, and the preparation of the field cage for experiments successful.
It is concluded that from a biological viewpoint the irradiation of adults would be recommended; however, the feasibility of adult irradiation on a large scale is questionable. The next steps would be to scale up irradiation procedures to accommodate much larger numbers of insects, and to determine male competitiveness in the semi-field system in Sudan. However, many other factors including mass rearing, sexing, and release methodology, are of importance for an SIT programme and only when all components are in place can the true feasibility of the SIT in Sudan be determined.

Uit de mest- en mineralenprogramma's : Gebruik van stabiele isotopen in mest- en mineralenonderzoek
Groenigen, J.W. van - \ 2005
Wageningen : Alterra (Informatieblad mest- en mineralenprogramma's 398.63) - 2
nitraat - mineralen - denitrificatie - stabiele isotopen - analytische methoden - isotopenlabelling - meting - bereikt resultaat - nitrate - minerals - denitrification - stable isotopes - analytical methods - isotope labeling - measurement - achievement
De commissie Spiertz II heeft in 2000 aanbevolen om geavanceerde en veelbelovende onderzoeksmethodieken toe te passen in het mest- en mineralenonderzoek. Dit heeft geleid tot een aantal proeven waarin het gebruik van stabiele isotopen is verkend. Deze proeven lopen in 2005 ten einde en in dit informatieblad wordt een voorlopige balans opgemaakt van het gebruik van stabiele isotopen in het mest- en mineralen onderzoek
Nitraatconcentraties in het bovenste grondwater in een bufferstrook en aangrenzende akker; resultaten van twee jaar experimenteel ondezoek aan een grasbufferstrook op zandgrond op akkerbouwbedrijf Vredepeel
Beek, C.L. ; Heinen, M. ; Clevering, O.A. ; Kleef, J. van - \ 2005
Wageningen : Alterra (Alterra-rapport 1263) - 78
nitraat - fosfaat - bodemwater - denitrificatie - uitspoelen - stabiele isotopen - akkerbouw - nederland - bodemchemie - bufferzones - de peel - nitrate - phosphate - soil water - soil chemistry - denitrification - leaching - stable isotopes - arable farming - netherlands - buffer zones
Gedurende twee uitspoelseizoenen zijn hydrologische en chemische bepalingen uitgevoerd in een grasbufferstrook en in de aangrenzende akker op een akkerbouwbedrijf op zandgrond. Nitraatconcentraties in het (bovenste) grondwater waren lager onder de bufferstrook dan onder de akker. Stabiele isotopen-ratio’s, ondersteund door Cl/NO3-N verhoudingen, gaven aan dat deze daling in een aantal gevallen veroorzaakt werd door denitrificatie in de bodem. De nitraatconcentraties in de bufferstrook waren gemiddeld 40% tot 55% lager dan in de akker. Echter, omdat het hier een observationele proef betreft konden geen causale verbanden worden gelegd
Isotopic tracer techniques for studying the bioavailabitity and bioefficacy of dietary carotenoids, particularly ß-carotene, in humans: a review
Lieshout, M. van; West, C.E. ; Breemen, R.B. van - \ 2003
American Journal of Clinical Nutrition 77 (2003). - ISSN 0002-9165 - p. 12 - 28.
performance liquid-chromatography - vitamin-a status - ionization mass-spectrometry - pressure chemical-ionization - total-body stores - stable isotopes - adult volunteer - plasma kinetics - alpha-carotene - animal-models
Vitamin A deficiency is a serious health problem in many developing countries. Provitamin A carotenoids in fruit and vegetables are the major source of vitamin A for a large proportion of the world's population. However, the contribution of plant foods is substantial only when both the consumption and provitamin A content of such food is high and, at the same time, the bioefficacy of the provitamin A is high. With respect to provitamin A carotenoids, the term bioefficacy is defined as the product of the fraction of the ingested amount that is absorbed (bioavailability) and the fraction of that which is converted to retinol in the body (bioconversion). Isotopic tracer techniques can meet the need for accurate and precise estimates of the bioavailability, bioconversion, and bioefficacy of dietary carotenoids in humans. Use of such techniques will enable proper evaluation of food-based approaches to eliminating vitamin A deficiency. In addition, the putative antioxidant capacities of carotenoids can be better understood if their bioavailability is known. Here, we discuss how tracer techniques can be applied to obtain reliable and representative data. A step-by-step discussion of aspects related to these techniques is provided, including study design, choice of isotopic tracers, dosing regimen, collection of samples, chemical analysis of samples, and data analysis.
Tracing 15N through landscapes: potential uses and precautions
Bedard-Haughn, A. ; Groenigen, J.W. van; Kessel, C. van - \ 2003
Journal of Hydrology (2003)1-4. - ISSN 0022-1694 - p. 175 - 190.
biological nitrogen-fixation - natural-abundance - isotopic fractionation - scale variations - ground-water - nitrate contamination - dinitrogen fixation - fertilizer nitrogen - spatial variability - stable isotopes
Stable N isotopes are used to examine the source, flow and fate of N at scales ranging from greenhouse pots to landscapes. There are two main approaches: the 15N-enriched method applies an artificially enriched source of 15N and the 15N natural abundance (15N) method uses natural 15N differences between N sources and sinks.The 15N method is good for semi-quantitative estimates of N flow in undisturbed ecosystems, for analyzing patterns, and for developing new hypotheses, particularly when spatial variability across a landscape or watershed can be explained. The spatial variability of 15N across a landscape is often non-random, following predictable spatial patterns. Topographic features control the rate of various hydrological and biological processes, resulting in significantly different 15N between lower and upper slope positions. However, if the difference between source-15N and sink-15N is small due to inherent background variability and/or if fractionating processes have a large effect on the isotopic signature of the N to be traced, 15N will not work as a tracer.With the 15N-enriched method, the isotopic signature of the enriched tracer can be pre-determined to ensure a significant difference in atom%15N between source and background levels, even when fractionation occurs. In most situations, the 15N-enriched method can be successfully used as a tracer to test hypotheses and to quantify N cycling through the landscape, regardless of background variability in 15N. Limitations of the 15N-enriched method include the cost associated with applying an enriched tracer, especially at the landscape scale, and the potentially confounding effects of applying N to a previously undisturbed landscape.
Stable nitrogen isotopes : study about its use in the assessment of denitrification and N fixation
Carratala Sanchez, C. - \ 2001
Wageningen : Plant Research International (Note / Plant Research International 145) - 19
stikstof - stikstofkringloop - stabiele isotopen - stikstoffixatie - denitrificatie - meting - methodologie - nitrogen - nitrogen cycle - stable isotopes - nitrogen fixation - denitrification - measurement - methodology
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