Effect of geomorphology and nitrogen deposition on rate of vegetation succession in inland drift sands
Sparrius, L.B. ; Kooijman, A.M. ; Riksen, M.J.P.M. ; Sevink, J. - \ 2013
Applied Vegetation Science 16 (2013)3. - ISSN 1402-2001 - p. 379 - 389.
campylopus-introflexus - soil development - organic-matter - coastal dunes - netherlands - dry - erosion - wind - moss
Questions (1) At what rate does succession take place in active and more stabilized drift sands in regions with low and high N deposition in the Netherlands? (2) What is the present composition of pioneer vegetation in active and more stabilized drift san
The physical chemistry of the enigmatic phospholipid diacylglycerol pyrophosphate
Strawn, Liza ; Babb, Amy ; Testerink, Christa ; Kooijman, Edgar Eduard - \ 2012
Frontiers in Plant Science 3 (2012). - ISSN 1664-462X
Dgpp - Diacylglycerol pyrophosphate - Effective lipid shape - Electrostatic hydrogen bond switch - Ionization - Lipid second messenger - Phosphatidic acid - Phospholipid signaling
Phosphatidic acid (PA) is a lipid second messenger that is formed transiently in plants in response to different stress conditions, and plays a role in recruiting protein targets, ultimately enabling an adequate response. Intriguingly, this increase in PA concentration in plants is generally followed by an increase in the phospholipid diacylglycerolpyrophosphate (DGPP), via turnover of PA. Although DGPP has been shown to induce stress-related responses in plants, it is unclear to date what its molecular function is and how it exerts its effect. Here, we describe the physicochemical properties, i.e., effective molecular shape and charge, of DGPP. We find that unlike PA, which imparts a negative curvature stress to a (phospho)lipid bilayer, DGPP stabilizes the bilayer phase of phosphatidylethanolamine (PE), similar to the effect of phosphatidylcholine (PC). DGPP thus has zero curvature. The pKa2 of the phosphomonoester of DGPP is 7.44 ± 0.02 in a PC bilayer, compared to a pKa2 of 7.9 for PA. Replacement of half of the PC with PE decreases the pKa2 of DGPP to 6.71 ± 0.02, similar to the behavior previously described for PA and summarized in the electrostatic-hydrogen bond switch model. Implications for the potential function of DGPP in biomembranes are discussed.
Rapid recognition at 10 months as a predictor of language development
Junge, C. ; Kooijman, V.M. ; Hagoort, P. ; Cutler, A. - \ 2012
Developmental Science 15 (2012)4. - ISSN 1363-755X - p. 463 - 473.
event-related potentials - word segmentation - continuous speech - phonotactic knowledge - sound patterns - infants - brain - acquisition - nonsense - memory
Infants' ability to recognize words in continuous speech is vital for building a vocabulary. We here examined the amount and type of exposure needed for 10-month-olds to recognize words. Infants first heard a word, either embedded within an utterance or in isolation, then recognition was assessed by comparing event-related potentials to this word versus a word that they had not heard directly before. Although all 10-month-olds showed recognition responses to words first heard in isolation, not all infants showed such responses to words they had first heard within an utterance. Those that did succeed in the latter, harder, task, however, understood more words and utterances when re-tested at 12 months, and understood more words and produced more words at 24 months, compared with those who had shown no such recognition response at 10 months. The ability to rapidly recognize the words in continuous utterances is clearly linked to future language development.
Autonomic nervous system responses on and facial expressions to the sight, smell and taste of liked and disliked foods
Wijk, R.A. de; Kooijman, V.M. ; Verhoeven, R.H.G. ; Holthuysen, N.T.E. ; Graaf, C. de - \ 2012
Food Quality and Preference 26 (2012)2. - ISSN 0950-3293 - p. 196 - 203.
Abstract Traditional sensory and consumer tests predict long term consumer acceptance of new products rather poorly, as evidenced by the high failure rates of new market introductions. These tests typical reflect conscious processes whereas consumer acceptance may also be based on unconscious processes, which may be measured by implicit physiological and behavioral measures. This study with 16 children (aged 8–10 years) and 15 young adults (mean age 22 years) explored the use of selected physiological and behavioral measures of the autonomic nervous system (ANS) in the study of foods. Three liked and three disliked foods were selected for each participant and their responses were measured during the first sight of each food and when they received the instruction to either visually inspect, smell or taste the foods. The first sight of disliked foods compared to liked foods resulted in increased skin conductance responses (p = 0.05) and increased facial expressions of sadness, disgust, and angriness (p = 0.05). Skin conductance responses (SCRs) varied significantly with the type of instruction (p <0.001), with relatively small SCRs when participants were instructed to visually inspect the foods and larger SCRs when they are instructed to taste or smell the foods. When instructed to taste the foods, children showed increased SCRs for disliked foods while young adults showed decreased SCRs (p = 0.02). Heart rate varied with instruction and age group (p = 0.03). Children showed increased heart rate when instructed to visual inspect or taste the foods and reduced heart rate they were instructed to smell them. In contrast, young adults showed reduced heart rate when instructed to visual inspect and increased heart rate with instructed to taste or smell. Finger temperature was higher for liked foods than for disliked foods, irrespective of instruction and age group (p <0.01). It is concluded that implicit ANS and behavioral responses provide detailed information on food preferences in relation to specific food properties and phases of food sampling that may not be provided by other more explicit tests.
Youth, Nutrition and Behaviour
Voordouw, J. ; Snoek, H.M. ; Broek, E. van den; Reinders, M.J. ; Meeusen, M.J.G. ; Veggel, R.J.F.M. van; Kooijman, V.M. ; Stijnen, D.A.J.M. ; Trentelman, I. - \ 2012
Den Haag : LEI, onderdeel van Wageningen UR - 9
voeding en gezondheid - jeugd - schoollunches - gedrag - kinderen - schoolmaaltijden - schoolkinderen - schoolontbijten - nutrition and health - youth - school lunches - behaviour - children - school meals - school children - school breakfasts
Healthy nutrition is widely assumed to have a beneficial influence on educational performance and social behaviour. Yet research in developed countries about the effects of food intake on children's behaviour and school performance is limited. We propose a randomised controlled field experiment to study the effects of a school lunch programme in the Netherlands, based on an overview of studies by LEI and Food and Biobased Research, both part of Wageningen UR.
Effects of Visual Priming on Taste-Odor Interaction
Beilen, M. van; Bult, J.H.F. ; Renken, R. ; Stieger, M.A. ; Thumfart, S. ; Cornelissen, F. ; Kooijman, V.M. - \ 2011
PLoS ONE 6 (2011)9. - ISSN 1932-6203 - 9 p.
olfactory perception - sucrose solutions - perceived flavor - color - sweetness - discrimination - intensity - mixtures - texture - vision
Little is known about the influence of visual characteristics other than colour on flavor perception, and the complex interactions between more than two sensory modalities. This study focused on the effects of recognizability of visual (texture) information on flavor perception of odorized sweet beverages. Participants rated the perceived sweetness of odorized sucrose solutions in the presence or absence of either a congruent or incongruent visual context. Odors were qualitatively reminiscent of sweet foods (strawberry and caramel) or not (savoury). Visual context was either an image of the same sweet foods (figurative context) or a visual texture derived from this product (non-figurative context). Textures were created using a texture synthesis method that preserved perceived food qualities while removing object information. Odor-taste combinations were rated sweeter within a figurative than a non-figurative context. This behaviour was exhibited for all odor-taste combinations, even in trials without images, indicating sustained priming by figurative visual context. A non-figurative context showed a transient sweetening effect. Sweetness was generally enhanced most by the strawberry odor. We conclude that the degree of recognizability of visual information (figurative versus non-figurative), influences flavor perception differently. Our results suggest that this visual context priming is mediated by separate sustained and transient processes that are differently evoked by figurative and non-figurative visual contexts. These components operate independent of the congruency of the image-odor-taste combinations.
The "covariation method" for estimating the parameters of the standard Dynamic energy Budget model I: Philosophy and apporach
Lika, K. ; Kearney, M.R. ; Freitas, V. ; Veer, H.W. van der; Meer, J. van der; Wijsman, J.W.M. ; Pecquerie, L. ; Kooijman, S.A.L.M. - \ 2011
Journal of Sea Research 66 (2011)4. - ISSN 1385-1101 - p. 270 - 277.
multiple end-points - life-cycle - deb theory - toxicity - biology
The Dynamic Energy Budget (DEB) theory for metabolic organisation captures the processes of development, growth, maintenance, reproduction and ageing for any kind of organism throughout its life-cycle. However, the application of DEB theory is challenging because the state variables and parameters are abstract quantities that are not directly observable. We here present a new approach of parameter estimation, the covariation method, that permits all parameters of the standard Dynamic Energy Budget (DEB) model to be estimated from standard empirical datasets. Parameter estimates are based on the simultaneous minimization of a weighted sum of squared deviations between a number of data sets and model predictions or the minimisation of the negative log likelihood function, both in a single-step procedure. The structure of DEB theory permits the unusual situation of using single data-points (such as the maximum reproduction rate), which we call “zero-variate” data, for estimating parameters. We also introduce the concept of “pseudo-data”, exploiting the rules for the covariation of parameter values among species that are implied by the standard DEB model. This allows us to introduce the concept of a generalised animal, which has specified parameter values. We here outline the philosophy behind the approach and its technical implementation. In a companion paper, we assess the behaviour of the estimation procedure and present preliminary findings of emerging patterns in parameter values across diverse taxa.
Inland dunes in The Netherlands: soil, vegetation, nitrogen deposition and invasive species
Sparrius, L.B. - \ 2011
University of Amsterdam (UvA). Promotor(en): J. Sevink; Leo Stroosnijder, co-promotor(en): A.M. Kooijman. - Amsterdam :
eolisch zand - stikstof - vegetatie - invasieve soorten - bodemchemie - nederland - aeolian sands - nitrogen - vegetation - invasive species - soil chemistry - netherlands
Zandverstuivingen, zoals het Kootwijkerzand en de Loonse en Drunense Duinen, ontstonden door overbegrazing en het gebruik van heideplaggen voor het bemesten van akkerland. Door de industriële revolutie veranderde het landgebruik en zijn er nu nog maar enkele zandverstuivingen over. Vanwege de bijzondere planten en dieren en de cultuurhistorische achtergrond zijn veel van deze natuurgebieden nu Europees beschermd. Zandverstuivingen verdwijnen zonder gericht beheer. Laurens Sparrius onderzocht acht zandverstuivingen en vond dat het oppervlak aan kaal zand sinds 1950 is gehalveerd. Ook bleek dat stikstof uit de landbouw het dichtgroeien versnelt. In provincies met weinig luchtvervuiling, zoals Friesland en Drenthe, bleken zandverstuivingen over de laatste vijftig jaar stabieler dan op de Veluwe, met meer intensieve veehouderij. Verder neemt door stikstof de kwaliteit van de begroeiing van stuifzandgebieden af en verdwijnt de oorspronkelijke korstmossenbegroeiing. In plaats hiervan komen dikke tapijten van het invasieve mos Grijs kronkelsteeltje, een uitheemse plantensoort die rond 1960 naar Nederland is gekomen. Het verdwijnen van zandverstuivingen kan volgens Sparrius worden tegengegaan door het verminderen van de stikstofdepositie, uitbreiden van zandverstuivingen door naaldbos te kappen en verwijderen van jonge bomen in stuifzanden.
|Vegetation succession in eight inland drift sands to geomorphology and nitrogen deposition
Sparrius, L.B. ; Kooijman, A.M. ; Riksen, M.J.P.M. ; Sevink, J. - \ 2011
In: Inland dunes in the Netherlands: soil, vegetation, nitrogen deposition and invasive species / Sparrius, L.B., Amsterdam : Universiteit van Amsterdam - p. 30 - 49.
Phosphatidic acid: An electrostatic/ hydrogen-bond switch?
Kooijman, Edgar Eduard ; Testerink, Christa - \ 2010
In: Lipid Signaling in Plants / Munnik, Teun, Springer (Plant Cell Monographs ) - ISBN 9783642038723 - p. 203 - 222.
Phosphatidic acid (PA) has been shown to be an important bioactive lipid that is specifically recognized by various proteins. As such, it plays a crucial role in cellular signaling in all eukaryotes. An important determinant for PA's role in its diverse functions is its anionic headgroup that resides very close to the hydrophobic interior of the lipid bilayer. In this chapter, we describe a new model, the electrostatic/ hydrogen-bond switch that describes PA's ionization properties and its specific interaction with proteins. Furthermore, we will allude to the broader implications of the model for all phosphomonoester moieties found in biological compounds. Recent data in support of the model, as well as biological predictions arising from it, are also discussed.
Editorial for the Special Food Summit 2008 Issue of Chemosensory Perception
Kooijman, V.M. ; Stafleu, A. ; Stieger, M.A. ; Hamer, R.H. ; Graaf, C. de - \ 2010
Chemosensory Perception 3 (2010)1. - ISSN 1936-5802
Extrapolating toxic effects on individuals to the population level: the role of dynamic energy budgets
Jager, T. ; Klok, T.C. - \ 2010
Philosophical Transactions of the Royal Society B. Biological sciences 365 (2010)12. - ISSN 0962-8436 - p. 3531 - 3540.
earthworm dendrobaena-octaedra - multiple end-points - lumbricus-rubellus - intrinsic rate - growth rate - life-cycle - models - reproduction - copper - tests
The interest of environmental management is in the long-term health of populations and ecosystems. However, toxicity is usually assessed in short-term experiments with individuals. Modelling based on dynamic energy budget (DEB) theory aids the extraction of mechanistic information from the data, which in turn supports educated extrapolation to the population level. To illustrate the use of DEB models in this extrapolation, we analyse a dataset for life cycle toxicity of copper in the earthworm Dendrobaena octaedra. We compare four approaches for the analysis of the toxicity data: no model, a simple DEB model without reserves and maturation (the Kooijman–Metz formulation), a more complex one with static reserves and simplified maturation (as used in the DEBtox software) and a full-scale DEB model (DEB3) with explicit calculation of reserves and maturation. For the population prediction, we compare two simple demographic approaches (discrete time matrix model and continuous time Euler–Lotka equation). In our case, the difference between DEB approaches and population models turned out to be small. However, differences between DEB models increased when extrapolating to more field-relevant conditions. The DEB3 model allows for a completely consistent assessment of toxic effects and therefore greater confidence in extrapolating, but poses greater demands on the available data.
Preadvies mossen en korstmossen.
Bijlsma, R.J. ; Aptroot, A. ; Dort, K.W. van; Haveman, R. ; Herk, C.M. van; Kooijman, A.M. ; Sparrius, L.B. ; Weeda, E.J. - \ 2009
Ede : Directie Kennis, Ministerie van Landbouw, Natuur en Voedselkwaliteit (Rapport DK nr. 2009/dk104-O ) - 255
mossen - bryophyta - korstmossen - soorten - bedreigde soorten - landschap - milieubeheer - nederland - natuurbeheer - natura 2000 - mosses - bryophyta - lichens - species - endangered species - landscape - environmental management - netherlands - nature management - natura 2000
Binnen het in OBN-kader uitgevoerd onderzoek was tot nu toe vaak aandacht voor de ruim 580 soorten mossen (inclusief variëteiten) en 800 soorten korstmossen die in Nederland voorkomen. Uit de Rode Lijsten blijkt dat er alle aanleiding is om meer aandacht te geven aan deze groepen. De achteruitgang van mossen en korstmossen speelt landelijk en in alle landschappen. Het Deskundigenteam Heuvellandschap heeft het preadvies begeleid namens alle deskundigenteams (droog zandlandschap, nat zandlandschap en beekdallandschap; rivierenlandschap; laagveenlandschap; zeekleilandschap; duin- en kustlandschap). Bij dit onderwerp zijn betrokken geweest: Universiteit Utrecht, Universiteit van Amsterdam, B ware (Radboud Universiteit), BLWG, Forestfun ecologisch advies en onderzoek, Alterra
Paradoxical differences in N-dynamics between Luxembourg soils: litter quality or parent material?
Kooijman, A.M. ; Smit, A. - \ 2009
European Journal of Forest Research 128 (2009)6. - ISSN 1612-4669 - p. 555 - 565.
gross nitrogen transformations - organic-matter - beech forests - terrestrial ecosystems - humus forms - mineralization - decomposition - availability - patterns - earthworms
To explore whether litter quality could alter differences in N-dynamics between soil types, we compared spruce and beech growing on soils with parent material sandstone and limestone, and beech and hornbeam on acid marl and limestone. We measured pH, organic matter content, C:N ratio, soil respiration and net N-mineralization of the organic layer and the mineral topsoil in a laboratory incubation experiment and estimated gross N-mineralization and immobilization with a simulation model. Species effects were restricted to the organic layer, but higher mass for low-degradable species was compensated by higher process rates for high-degradable ones, so N-dynamics per square metre did not differ. Also, the mineral topsoil was not affected by litter quality, which may have been overruled by soil conditions. Forest soils formed from different parent materials, however, clearly differed in N-dynamics, although different from expectations for net N-mineralization. Sandstone showed low respiration and gross N-mineralization, but net N-mineralization was higher than expected, probably due to low microbial N-demand. In contrast, limestone, and to some extent acid marl, showed high respiration and gross N-release, but lower net N-mineralization than expected, because microbial immobilization was also high. Simulated gross N-mineralization even showed a negative instead of positive correlation with net N-mineralization, probably due to the strong increase in immobilization when gross N-mineralization is high. The shift in microbial N-demand may in turn be related to a more general shift from bacteria to fungi over pH-gradients.
|Onderzoek naar effectgerichte maatregelen voor het herstel en beheer van stuifzanden
Sparrius, L.B. ; Kooijman, A. ; Nijssen, M. ; Esselink, H. ; Burg, A. Van den; Riksen, M. ; Kuiters, A.T. ; Bijlsma, R.J. ; Waal, R.W. de; Dobben, H.F. van; Ketner-Oostra, R. ; Jongerius, P. ; Turnhout, C. van; Swaay, C. van - \ 2008
Amsterdam, Nijmegen, Wageningen : Stichting Bargerveen, Universiteit van Amsterdam, Radboud Universiteit, Alterra, Wageningen Universiteit (Tweede tussenrapport, februari 2008 ) - 86 p.
|Geoloketten leert: hanteerbaarheid voor de gebruiker is grootste knelpunt
Hoogerwerf, M.R. ; Kuyper, M.C. ; Kooijman, J. ; Vermeij, B. ; Bulens, J.D. - \ 2008
VI Matrix 16 (2008)3. - ISSN 0929-6107 - p. 22 - 25.
informatiesystemen - geoinformatie - information systems - geoinformation
Het project GeoLoketten wil geo-informatie in Nederland optimaal toegankelijk maken via webservices. In het kader van het innovatieprogramma Ruimte voor Geo-informatie worden daarvoor methoden en technieken ontwikkeld. Innoveren moet je leren, maar dit leertraject bleek bijzonder dynamisch. Al is de geosector nog zo snel, de ict-wereld achterhaalt haar wel
Ureidobenzotriazine Multiple H-Bonding Arrays: The Importance of Geometrical Details on the Stability of H-Bonds
Ligthart, G.B.W.L. ; Guo, D. ; Spek, A.L. ; Kooijman, H. ; Zuilhof, H. ; Sijbesma, R.P. - \ 2008
Journal of Organic Chemistry 73 (2008)1. - ISSN 0022-3263 - p. 111 - 117.
3-amino-1,2,4-benzotriazine 1,4-dioxide tirapazamine - donor-acceptor interaction - pyridine n-oxides - hydrogen-bonds - heterocyclic ureas - molecular recognition - guanine-cytosine - guanidine base - complexes - polymers
A 3-ureidobenzo-1,2,4-triazine 1-N-oxide (1) was synthesized successfully. The derivative displays an acceptor-donor-acceptor-acceptor (ADAA) hydrogen-bonding motif in CDCl3 and DMSO-d6 solution as well as in the solid state. Although moderately strong association of 1 was observed with DAD motifs, nonspecific binding is observed with ureidopyridines featuring a complementary DADD array. Density functional calculations of conformations 1a and 1b together with two complexes revealed the clearly nonplanar geometry of the multiply hydrogen-bonded complex, in which some bonds are significantly longer (3.2 Å) than is optimal for H-bonds. As a result, only very small free energies of association were calculated, in line with the experimentally observed absence of specific assembly of the components.
An electrostatic/hydrogen bond switch as the basis for the specific interaction of phosphatidic acid with proteins
Kooijman, Edgar E. ; Tieleman, D.P. ; Testerink, Christa ; Munnik, Teun ; Rijkers, Dirk T.S. ; Burger, Koert N.J. ; Kruijff, Ben De - \ 2007
Journal of Biological Chemistry 282 (2007)15. - ISSN 0021-9258 - p. 11356 - 11364.
Phosphatidic acid (PA) is a minor but important phospholipid that, through specific interactions with proteins, plays a central role in several key cellular processes. The simple yet unique structure of PA, carrying just a phosphomonoester head group, suggests an important role for interactions with the positively charged essential residues in these proteins. We analyzed by solid-state magic angle spinning 31P NMR and molecular dynamics simulations the interaction of low concentrations of PA in model membranes with positively charged side chains of membrane-interacting peptides. Surprisingly, lysine and arginine residues increase the charge of PA, predominantly by forming hydrogen bonds with the phosphate of PA, thereby stabilizing the protein-lipid interaction. Our results demonstrate that this electrostatic/hydrogen bond switch turns the phosphate of PA into an effective and preferred docking site for lysine and arginine residues. In combination with the special packing properties of PA, PA may well be nature's preferred membrane lipid for interfacial insertion of positively charged membrane protein domains.
A new class of non-linear stochastic population models with mass conservation
Kooijman, S.A.L.M. ; Grasman, J. ; Kooi, B.W. - \ 2007
Mathematical Biosciences 210 (2007)2. - ISSN 0025-5564 - p. 378 - 394.
dynamics - ecosystems - quality - time
We study the effects of random feeding, growing and dying in a closed nutrient-limited producer/consumer system, in which nutrient is fully conserved, not only in the mean, but, most importantly, also across random events. More specifically, we relate these random effects to the closest deterministic models, and evaluate the importance of the various times scales that are involved. These stochastic models differ from deterministic ones not only in stochasticity, but they also have more details that involve shorter times scales. We tried to separate the effects of more detail from that of stochasticity. The producers have (nutrient) reserve and (body) structure, and so a variable chemical composition. The consumers have only structure. so a constant chemical composition. The conversion efficiency from producer to consumer, therefore, varies. The consumers use reserve and structure of the producers as complementary compounds, following the rules of Dynamic Energy Budget theory. Consumers die at constant specific rate and decompose instantaneously. Stochasticity is incorporated in the behaviour of the consumers, where the switches to handling and searching, as well as dying are Poissonian point events. We show that the stochastic model has one parameter more than the deterministic formulation without time scale separation for conversions between searching and handling consumers, which itself has one parameter more than the deterministic formulation with time scale separation for these conversions. These extra parameters are the contributions of a single individual producer and consumer to their densities, and the ratio of the two, respectively. The tendency to oscillate increases with the number of parameters. The focus bifurcation point has more relevance for the asymptotic behaviour of the stochastic model than the Hopf bifurcation point, since a randomly perturbed damped oscillation exhibits a behaviour similar to that of the stochastic limit cycle particularly near this bifurcation point. For total nutrient values below the focus bifurcation point, the system gradually becomes more confined to the direct neighbourhood of the isocline for which the producers do not change. (C) 2007 Elsevier Inc. All rights reserved.
Material flows in a social context : a Vietnamese case study combining the materials flow analysis and action-in-context frameworks
Hobbes, M. ; Stalpers, S.I.P. ; Kooijman, J. - \ 2007
Journal of Industrial Ecology 11 (2007)1. - ISSN 1088-1980 - p. 141 - 159.
Materials flow analysis (MFA) is one of the central achievements of industrial ecology. One direction in which one can move MFA beyond mere accounting is by putting the material flows in their social context. This "socially extended MFA" may be carried out at various levels of aggregation. In this article, specific material flows will be linked to concrete actors and mechanisms that cause these flows¿using the action-in-context (AiC) framework, which contains, inter alia, both proximate and indirect actors and factors. The case study site is of Tat hamlet in Vietnam, set in a landscape of paddy fields on valley floors surrounded by steep, previously forested slopes. Out of the aggregate MFA of Tat, the study focuses on material flows associated with basic needs and sustainability. The most important actors causing these material flows are farming households, politicians, traders, and agribusiness firms¿of which local politicians turned out to be pivotal. The study shows the value of combining MFA with actor-based social analysis. MFA achieves the balanced quantification of the physical system, thus helping to pinpoint key processes. Actor-based analysis adds the causal understanding of what drives these key processes, leading to improved scenarios of the future and the effective identification of target groups and instruments for policy making.