Completed Projects

Effects of uranium on zebrafish: biomarkers and history life traits

Investigator: Mrs S. Augustine
Period: 2008/12/01 - 2012/05/30
Collaboration: IRSN, Dr. Christelle Adam; Dr. Béatrice Gagnaire
Support: IRSN
Description: The aim of this project is to understand how the long term dynamics of Danio rerio are affected by exposure to environmentally relevant concentrations of waterborne uranium. Three previous theses within the LRE have worked on how uranium interacts with D. rerio. Using the data collected as well as experimental protocols put in place this fourth project seeks to understand how early responses of the immune and the oxidative stress systems (measured at molecular and cellular levels) are coupled to responses measured at the level of the individual (mortality, reproduction) or even the population. The main focus of this work will be on linking these different levels of biological organisation through the DEB theory and understanding the mechanisms at stake. More
Definition: Full text in pdf format

Biology-based methods for risk assessment

Investigator: T. Jager
Period: 2006/10/01 - 2007/10/01
Collaboration: European Chemicals Bureau (ECB) (Hélène Magaud, Erik van de Plassche)
Support: JRC-ECB
Code: BMecb in Biomass cluster, FALW 2956.301, CCR.IHCP.C432545.X0
Description: In the European Union, risk assessment for chemicals is based, amongst others, on simple summary statistics for ecotoxicological effects, such as the LC50 and the NOEC. These statistics have severe limitations that endanger the relevance of risk assessments. Biologically-based methods, such as DEBtox, offer better ways to analyze toxicity data, but at this moment, such methods are not used within the regulatory context. However, biologically-based methods are discussed (next to the more classical approaches of hypothesis testing and regression analysis) in a recent ISO/OECD guidance document on the statistical analysis of ecotoxicity data (OECD, 2006). It is the purpose of this contract to introduce these methods to the regulatory community, and explore the possibilities for implementation in risk assessment methodology. More
Definition: Full text in pdf format

Toxicity of mixtures of compounds

Investigator: J. Baas
Period: 2005/10/01 - 2009/10/01 (start project 2004/11/01)
Collaboration: VU-Institute for Ecological Sciences (Kees van Gestel, Mieke Broerse)
Support: EU-Sixth-Framework Programme "Global Change and Ecosystems":
"Development of Risk Assessment Methodologies"
Code: Nomiracle, FALW 2947.306
Description: Each chemical compound can occur in three concentration ranges: "too little", "enough" and "too much". The physiological response to changes in concentration is weak in the "enough"-range. Some chemicals have a similar mode of action and one chemical can enhance the effect of the other compound. This affects the boundaries of the "enough"-range. This project aims to evaluate the possible forms of interaction between two compounds (including the ionic and molecular form of a single compound), and to give an adequate statistical description of a mixture of many compounds in terms of frequency distributions of kinetic and effect parameters. This theoretical study will be done in close collaboration with an experimentally oriented ecological group. More.
Definition: Intro, aims, detail the focus is on Research Pillar 4

Toxic effects on canonical communities

Investigator: D. Bontje & B. Kooi
Period:2005/04/01 - 2010/01/31
Collaboration: ECT Oekotoxicologie Gmbh (Thomas Knacker, Markus Liebig)
UFZ-Umweltforschungzentrum Leipzig-Halle (Mechthild Schmitt-Jansen, Christina Klünder)
VU-IVM Environmental Studies (Bert van Hattum)
Support: EU-Sixth-Framework Programme "Global Change and Ecosystems":
"Integrating and Strengthening the European Research Area"
Code: Modelkey; FALW 2947305
Description: Toxic effects on individuals of a particular species or group of species can have complex implications for an integrated ecosystem. We study the relationships between these levels of organisation with canonical communities (closed ecosystems with three species (groups): producers, consumers and decomposers). This theoretical analysis will be in close collaboration with experimentally oriented groups that will study effects in simple closed communities and in biofilms. Moreover, we collaborate with people who try to interprete the field data that will be collected in several river systems, and link observed effects to internal concentrations of selected compounds in species that have links in a food chain.
Definition: Full text in pdf format; the focus is on Work Package Effect 3

Temperature dependence of predation on estuarine bivalves

Investigator: Mrs V. Freitas
Period:2005/01/01 - 2010/02/01
Collaboration: Netherlands Institute for Sea Research, Texel, The Netherlands (H. van der Veer & J. van der Meer).
Support: Portugese FCT (Fundação para a Ciência e a Tecnologia)
Code: biv_prey
Description: Estuaries and coastal areas are important nursery areas for various fish species and resting and fuelling stations for migratory- and shorebirds. A main food source is formed by bivalves and the food availability is to a large extent determined by annual recruitment of spat, determined by the survival of the bivalve youngest stages after a period of severe predation by a complex of epibenthic predators (shrimps, shore crabs, gobies and flatfish). At present, no insight is available on how the key predator-prey factors and processes are acting and are affected and determined by temperature. Processes such as climate change, in this context referred to the expected increase in average water temperatures, might affect the regulating mechanisms and the overall survival. The main objectives of this project are to: [1] Analyze the various predator-prey relationships in relation to temperature with the aim to [2] Predict the impact of climate change on the functioning of various European estuaries as fuelling stations for migratory birds. More;
Definition: Text in pdf format

Growth and reproduction of the Pacific oyster

Investigator: Y. Bourles
Period:2004/12/01 - 2007/12/01
Collaboration: IFREMER, UMR PE2M, Station Expérimentale d'Argenton, Presqu'île du Vivier, 29840 Argenton en Landunvez (Stéphane Pouvreau).
IFREMER, UMR 6217, Centre de Recherche sur les Ecosystèmes Marins Anthropisés - CRELA, Place du Séminaire, B.P. 5, 17137 L'Houmeau (Marianne Alunno-Bruscia).
Station IFREMER de La Tremblade, (Philippe Goulletquer).
Netherlands Institute for Sea Research, Texel, The Netherlands (H. van der Veer & J. van der Meer).
Support: IFREMER, Région Poitou-Charentes
Code: DEBoyster
Description: The Pacific oyster Crassostrea gigas is widely distributed around the world (New Zealand, Australia, United States, Japan etc.). Within Europe the species is found from the Norwegian Sea to the coasts of Morocco. Its wide distribution is accompanied by high spatial and temporal variability in growth performance. This project is to build a model which will be able to capture this high variability of oyster growth performance. Such a model would have to simulate the growth and reproduction of the Pacific oyster in all the different environments where it lives along French coasts. This new model, generic, is based on the DEB theory. More;
Definition: Text in pdf format

Bifurcation analysis of community models

Investigator: G. A. K. van Voorn
Period:2004/03/01 - 2009/03/01
Collaboration: Dept Mathematics, Utrecht University (Yu. A. Kuznetsov)
Inst for Chem & Biol of the Mar Environ., Oldenburg University (Mrs U. Feudel)
Support: Computational Life Sciences program (NWO-CLS)
Code: Globif; NWO 635.100.013; FALW 2947211
Description: Community models are often formulated as a continuous-time system of (autonomous) ordinary differential equations. Realistic medium-scale DEB-based community models (number of populations greater than 7 less than, say, 20) are studied using bifurcation theory including the study of local as well as global bifurcations. When complex dynamics occurs global bifurcations play an important role in so-called crises where under parameter variation chaotic behaviour disappears abruptly. So, continuation of these global bifurcations in the parameter space mark regions where chaos is to be expected. Other global bifurcations mark regions in the parameter space where invasion of a population into an existing food web leads to replacement or coexistence. Shil'nikov bifurcation form the `skeleton' in the parameter space for chaotic dynamics. More
Definition: Full text in pdf format

DOC degradation by marine bacteria in the water column

Investigator: Mrs M. Eichinger
Period:2004/10/01 - 2007/10/01
Collaboration: Laboratory of Microbiology Geochemistry and Marine Ecology, France, (Prof. J.C. Poggiale, Prof. R. Sempéré D. Lefévre, G. Grégori, B. Charriére).
Support: French National Program of Coastal Environment
Code: DEBdoc
Description: Dissolved organic carbon (DOC) is one of the largest pools of reduced carbon on the planet and is almost exclusively consumed by bacteria. We use the DEB theory to improve the quantification of the biodegradation in models for marine ecosystems and use it partition DOC in living biomass and refractory organic carbon that resists rapid biodegradation.

Organic carbon pump in meso-scale ocean flows

Investigator: J. Bruggeman & A. W. Omta & M. H. van Raalte
Period:2004/03/15 - 2009/03/15
Collaboration: Centrum voor Wiskunde en Informatica, Amsterdam (B. P. Sommeijer, M. van Raalte)
IMAU, Utrecht University (H. Dijkstra)
Support: Computational Life Sciences program (NWO-CLS)
Code: Cpump; NWO 635.100.009; FALW 2947210
Description: The 'organic carbon pump' is the rate at which algae bind atmospheric carbon dioxide, and transport it to deep waters in the form of organic carbon. In this project, a systematic 'first principle' multidisciplinary approach is followed to determine the effect of transport properties of oceanic meso-scale flows on the efficiency of the organic carbon pump. We do so by combining a realistic algal physiology model, based on the Dynamic Energy Budget theory, with simulations in a very high-resolution ocean model. The simulation results will be tested against in-situ data obtained during the Dutch MARE (Mixing of Agulhas Rings Experiment) project and the SeaWiFS (Sea-viewing Wide Field-of-View Sensor) satellite data. Our approach is unique in the combination of (i) the biological model which contains explicit energy and nutrient balances, while biomass composition is variable, (ii) the high-resolution ocean model to simulate flows details of the meso-scale flows and (iii) the advanced numerical methods used for determining the transport properties of nutrients and biomass. More
Definition: Full text in pdf format

Modelling brown ring disease in the manila clam

Brown ring disease (BRD) in the manila clam Ruditapes philippinarum is caused by the bacterial pathogen Vibrio tapetis. This disease affects shell growth and induces a brown conchiolin deposit on the inner shell. BRD development was shown to be controlled by (i) the environment, low temperature beeing suspected to enhance the disease, and (ii) the host physiology, a high variability in the disease development and recovery ability being observed. New results suggest that the disease is able to affect the host energy balance. A DEB model will be developed to better understand the complex interactions between the environment, the host and the pathogen.
Investigator: J. Flye Sainte Marie
Period:2004/01/01 - 2007/01/01
Collaboration: LEMAR (Laboratoire des sciences de l'Environnement MARin)
(Fred Jean), IUEM (Institut Universitaire européen de la mer - European Institute for Marine Studies)
Place Nicolas Copernic, 29280 PLOUZANE, FRANCE
Support: Programme de Recherche d'Interét Régional Bretagne
Description: More
Definition: Full text in pdf format

Growth and reproduction of Biscay anchovy

Investigator: Mrs L. Pecquerie
Period:2003/12/01 - 2006/12/01
Collaboration: Ifremer, Dept Ecologie & Modèles pour l'Halieutique, Rue de l'Ile d'Yeu BP 21105, 44311 Nantes Cedex 3
(Pierre Petitgas)
Support: Ifremer, Region Pays de la Loire, EU FISBOAT
Code: Anchovy
Description: Anchovy is an important target for fishery, which is presently under threat. The aim of the project is to understand the influence of the environment on the length of the spawning season. DEB theory is used in combination with primary production coupled to hydrodynamic-models to quantify growth and predict spawning events. Data on size and (otolith) growth are used to estimate parameters and test model predictions.

The role of the brown shrimp in the functioning of coastal estuaries

Investigator: Mrs J. Campos
Period:2003/08/01 - 2008/03/01
Collaboration: NIOZ, (H. van der Veer, J. van der Meer)
Support: Portugese FCT (Fundação para a Ciência e a Tecnologia)
Code: shrimp
Description: The brown shrimp Cragnon cragnon occurs along the European coast from the White till the Black Sea, including the North and Mediterranean seas. It copes with a wide range of temperatures and salinity conditions. The northern edge of its distribution is formed by temperature limitation in egg and larval development, and at the southern one by maintenance costs. Patterns in life history parameters are observed in North Atlantic subpopulations, most likely reflecting trends in temperature conditions. At present it is unclear whether the population dynamics of the species is top down or bottom up controlled; the brown shrimp might regulate some of their prey species. The project focusses on [1] the analysis of the genetic population structure by means of molecular tools; [2] the study of growth conditions in relation to latitude; [3] the application of Dynamic Energy Budgets for the analysis in terms of energy of the various trade-offs, including growth versus reproduction; and [4] the analysis of the mechanisms determining recruitment, especially whether top down or bottom up control is occurring.

Thermodynamic analysis of environmental systems

Investigator: Mrs T. Sousa
Period:2003/01/01 - 2006/11/01
Collaboration: Technical University Lisboa, program DEBbee (T. Domingos)
Support: PRODEP - Program for the Portuguese Educational Development
Code: DEBheat
Description: Economic systems have a lot in common with biological (eco)systems. This project aims to make the links and differences explicit, tries to generalize the Dynamic Energy Budget theory to include applications to economic systems and substantiate the notion of sustainability. The framework of thermodynamics will be used to analyse and compare the economic and biological systems. More

Dynamics of synthesising units

Investigator: J. Rodrigues
Period:2002/10/01 - 2006/10/01
Collaboration: Technical University Lisboa, program DEBbee (T. Domingos)
Support: Foundation for Science & Technology (Portugal)
Code: DEBsu
Description: A Synthetizing Unit (SU) is an enzyme whose dynamics generalize classical enzyme kinetics, but operate on substrate fluxes rather than concentrations. The dynamics of SUs have been worked out for some important situations but others remain to be explored. The goal of this project is to work out the dynamics of a spatially explicit SU network processing an arbitrary number of partially substitutable substrates. SUs appear in two different contexts in the DEB theory: assimilation and growth/maintenance. The results of this project are important to derive a generalized functional response (how assimilation responds to the abundance of substrates) and possibly suggests mechanisms that lead to the DEB rules for growth/maintenance. More
Definition: Full text in pdf format

Heterotrophic bacteria in marine sediments

Investigator: Mrs C. Tolla
Period:2002/10/01 - 2005/12/31
Collaboration: Laboratory of Microbiology Geochemistry and Marine Ecology, France, Prof. Dr. J.C. Poggiale
Institut de Recherche pour le Développement (IRD), France
, Prof. Dr. P. Auger
Support: French government
Code: DEBsed
Description: Most of substrate degradation or bacterial dynamical models have been validated on data obtained from laboratory experiments with fixed environmental conditions. In the natural environment, however, substrate concentrations are rarely constant and spatial or temporal variability of substrate supplies implies significant periods of near or actual famine. Indeed, as standard models don't describe the intrinsic mechanisms for the microbial transformations of substrates precisely, they do not describe microbial interactions appropriately in the case of environmental perturbations. The aim of this work is to improve the previous models analysing the bacterial dynamics, by taking explicitly into account the functionality of the community, microbial interactions and stoichiometric constraints on transformations. For this, we propose a new mechanistic model, based on the DEB theory, describing these processes at the enzymatic scale in order to study the effects of individuals response to variable environmental conditions. More; Poster
Definition: Full text in pdf format

Self organisation of community metabolism

Investigator: Mrs T. A. Troost
Period:2002/01/01 - 2006/01/01
Collaboration: Theoretical Biology, Leiden University (J. A. J. Metz)
IMAU, Utrecht University (H. Dijkstra)
Support: Vrije Universiteit, Amsterdam
Code: DEBorg
Description: The theory on adaptive dynamics is about quantitative changes at an evolutionary time scale in characteristics of species, as described by parameter values. These characteristics include rules for the (sloppy) heridity of parameter values in parent-offspring transitions. The theory can predict under what circumstances the scatter distribution of individual-specific parameters values breaks up, a process that corresponds with speciation. We want to apply this theory in a closed ecosystem, where the processes for substrate uptake and use are specified by the Dynamic Energy Budget (DEB) theory. Starting from a single-species community of mixotrophs, we will study the speciation into auto- and heterotrophs, and the evolution of food webs, using the body size scaling relationships that are implied by the DEB theory. We will select parameter values that are realistic for planktontic systems, and we will use ocean circulation models to judge the large-scale implications of the most simple ecosystems. More
Definition: Full text in pdf format

Toxic effects on reproduction

Investigator: D. T. Jager
Period:2002/01/01 - 2005/11/15
Collaboration: Lab of Nematology, Wageningen University (J. E. Kamminga, Mrs O. Alda Alvarez)
Support: STW-NWO, Procter & Gamble, Bruxelles
Code: DEBtox; STW-WEB.5509; FALW 2375209
Description: Toxicants can affect reproduction in a number of ways, with different consequences for how population dynamics depends on feeding conditions. We compare effects of a number of compounds with different modes of action for a number of nematode species which differ in their reproductive biology. The aim is to relate effects on individuals with those on population dynamics. The project has an experimental component (in Wageningen), and a theoretical one (in Amsterdam). The latter component aims to extend software package DEBtox with a more-sample analysis and with a module that allows an evaluation of population consequences, given effects on individuals. The more-sample analysis can be used to analyse different types of effects (e.g. on survival, growth and reproduction) simultaneously, and differences in effects between samples. More
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Modelling the ecosystem of the North Sea

Investigator: Mrs. C.D.P. Mulder
Period:2000/03/01 - 2000/12/01
Collaboration: RIKZ, Den Haag (R. Laane)
Support: RIKZ-RWS, Den Haag
Code: DEBsea
Description: Models for the North Sea ecosystem are analyzed for their contribution to understand the dynamics of the ecosystem. Attemps are made to apply and extend the Dynamic Energy Budget theory to model hierarchies in its organisation.
Definition: Full text in pdf format

Time scale separation in ecosystem dynamics

Investigator: B. W. Kooi & S. A. L. M. Kooijman
Period:2000/01/01 - 2007/12/31
Collaboration: Institut de Recherche pour le Développement (IRD), France, Prof. Dr. P. Auger
Laboratory of Microbiology Geochemistry and Marine Ecology, France, Prof. Dr. J.C. Poggiale
Support: van Gogh (NWO, Den Haag)
Code: van Gogh; NWO VGP62-550; FALW 2375207
Description: We study the process of model simplification by separation of time scales in models for ecosystems and foodwebs. We try to extract general principles from a collection of examples, where we compare the asymptotic behaviour the full model with the simplified ones.
Definition: Full text in pdf format

Role of food web structures

Investigator: L. D. J. Kuijper
Period:2000/02/01 - 2004/02/01
Collaboration: dept Ecol. Ecotox. VUA (M. Berg), Southampton Oceanography Centre ( T. Anderson), NIOO-Limnologisch Lab (A. Verschoor)
Support: Vrije Universiteit, Amsterdam
Code: DEBsys
Description: Models for ecosystems of increasing complexity are analyzed for their long-term nutrient cycling on the basis of the Dynamic Energy Budget theory. The project starts with a one-species community of mixotrophs; then follows a canonical communitie with producers, consumers and decomposers. The single-species consumers are then replaced by food web of increasing complexity, to study the relationship between structure and function on an ecosystem. More.
Definition: Full text in pdf format

Tumor-induction potential of chemicals

Investigator: Mrs. I. M. M. van Leeuwen , Mrs. F. D. L. Kelpin
Period:1999/03/01 - 2003/07/15
Collaboration: RIVM, Bilthoven (W. Slob, C.F. van Kreyl, H.J. van Kranen), OpdenKamp (W.K. de Raat), J. Kruse, DSM, (W.F. ten Berge)
Support: STW-NWO, Utrecht; DSM, Heerlen
Code: DEBtum; STW-VBI.4692; FALW 2375205
Description: A software package is written to analyse the results of standardized tests on the tumor-induction potential of chemicals for mice. The purpose is to combine the molecular biology of tumor induction with the physiology of tumor growth, and effects at the population level, in a way that is consistent with the Dynamic Energy Budget theory. More.
Definition: Full text in pdf format

Biological production in oceans

Investigator: B. W. Kooi, S. A. L. M. Kooijman & Mrs T. A. Troost
Period:1998/10/30 - 2004/02/01
Collaboration: IMAU ( H. Dijkstra)
Code: DEBmixo
Description: We incorporate a DEB-based model for nutrients and organic matter recycling by a single species community of mixotrophs in an ocean circulation model. One of the aims is to quantify the organic carbon pump by which carbon dioxide is extracted from the atmosphere, and brought to the deep ocean by biota. To understand the patterns, we first study what happens in a closed homogeneous environment, in a water column with a light and temperature gradient, and in Agulha rings.

Analysis of routine biodegradation tests

Investigator: M. Luger, P. Hanegraaf , B.W. Brandt
Period:1997/03/01 - 2002/02/01
Collaboration: TNO-Nutrition, Delft (A.O. Hanstveit), BKH, Delft (H. Blok), RIVM, Bilthoven (W. Slob, J. Struys), Procter & Gamble, Bruxelles (P. Masscheleyn, Mrs. J. Jaworska), Technical University Denmark, Lyngby (N. Nyholm)
Support: STW-NWO, Utrecht; Procter & Gamble, Bruxelles; IMW-TNO, Delft
Code: DEBdeg; SLW-805.39.751; STW-790.44.151; FALW 2375204
Description: A software package is written to analyse the results of routine biodegradation tests on the basis of the DEB model. Central to this effort is to find useful characterizations of rates the degradation process. More.
Definition: Full text in pdf format

Individual-based population dynamics

Investigator: Mrs. F. D. L. Kelpin
Period:1996/09/01 - 2001/03/01
Collaboration: University of Amsterdam (J. Kaandorp, P. Sloot), University of Leiden (J.A.J. Metz), University of Utrecht (O. Diekmann), CWI, Amsterdam (B. Sommeijer, M. Kirkilionis)
Support: priority program Massive Parallel Computation (NWO, Den Haag)
Code: MPR; NWO-94T057
Description: In situations of constant, or slowly changing, population sizes, the the reproduction rate of individuals can drop to levels where the behaviour of models that treat reproductive output as a continuous function can deviate from models that account for individuals as discrete units. Variations in parameter values between individuals also affects individuals. Parallel computational mehtods are used to find useful approximations to individual-based population dynamics. This project is part of the NWO program on Massive Parallel Computation. More.
Definition: Full text in pdf format

Impact of Emiliania on the global carbon flux

Investigator: C. Zonneveld
Period:1996/04/01 - 2001/06/30
Collaboration: University of Leiden (P. Westbroek), NIOZ, Texel (R. Riegman), University of Groningen (W. Gieskes, Mrs M. van Rijssel), CEMO-NIOO, Ierseke (J. Kromkamp)
Support: NOP2 Global Change (VROM, Bilthoven; NWO, Den Haag)
Code: NOP2; FALW 2375208
Description: Due to its capacity to utilize bicarbonate as carbon source, the coccolithophore Emiliania produces calcium carbonate scales in amounts such that its affects the global carbon flux and so climate. This project in the National Research Program on Global Change (NOP 2) aims at modelling the growth of Emiliania as function of nutrient concentrations, light and temperature. The second phase aims at modelling primary production in oceans.

Analysis of routine toxicity tests

Investigator: M. Luger
Period:1995/05/01 - 1996/05/01
Collaboration: TNO-Nutrition (A.O. Hanstveit, R. Hooftman), Technical University of Denmark, Lyngby (N. Nyholm), OECD (Mrs. N. Grandy), VROM (J. de Bruijn, C. van Leeuwen), RIVM (W. Slob)
Support: VROM, Den Haag
Description: A software package named DEBtox is written to analyse the results of routine toxicity tests on the basis of the deb model. Central to this effort is the statistical analysis of No-effect concentrations.

Sulphur and carbon fluxes in microbial mats

Investigator: H.A. van den Berg
Period:1994/04/01 - 1998/04/01
Collaboration: University of Amsterdam (L.J. Stal), University of Groningen (H. van Gemerden)
Support: priority program Perturbated Earth Systems (NWO, Den Haag)
Description: Microbial mats of coastal areas are known for their high physiological activity. When undisturbed, the production of sulphur compounds is limited, but when disturbed, high production rates might affect albedo and so climate. The eco-physiology of such mats is modelled to reveal the role of the various groups of microbes that are participating. The project is part of the NWO Program on Perturbation of Earth Systems.

Structured population dynamics

Investigator: M.P. Boer
Period: 1993/03/01 - 1998/03/01
Collaboration: University of Amsterdam (A. de Roos)
Support: priority program Non-Linear Systems (NWO, Den Haag)
Description: Study of the pay off between model complexity and realism in population dynamics. When DEB-structured individuals in a population are stripped from most of their physiological behaviour, (simple) classic models for population dynamics result that are thought to be less realistic. This will be tested and the best combination of simplicity and realism will be used to study the dynamics of food webs.

Global Emiliania Modelling initiative

Investigator: C. Zonneveld
Period: 1993/01/01 - 1995/12/31
Collaboration: Vrije Universiteit, Fac. Geology (J. v. Hinte), Leiden University, biochemistry (P. Westbroek), Plymouth Marine Laboratory (R. Harris, A. Taylor), Bergen University (B. Heimdal, J. Egge, D. Aksness), Trondheim University (M. Nielsen, E. Sakshaug), Oslo University (E. Paasche, S. Kristainsen), Britsh Museum (J. Young), Swansea Universit College (M. Merrett), Bristol University, Biogeogemistry Center (G. Eglinton), Southhampton University (D. Purdie), Marine Biological Association (C. Brownlee), Oviedo Universidad (E. Fernandez)
Support: MAST II (EU, Bruxelles)
Description: This EU-project aims to couple primary production in the oceans to sedimentation of carbonate that originates from the coccolithophore Emiliania huxleyii, in order to reconstruct paleoclimate from sediment samples. To this end, models are constructed for the growth of Emiliania as functions of concentrations of nutrients, light and temperature. The explanation for the occurence of large blooms is a point of focus.

Computers aided biological education

Investigator: V. Meulenbroek
Period: 1993/01/01 - 1995/11/15
Collaboration: Bureau Advies Onderwijs (R. Thijsse), Onderwijs Cordinator (Mrs. M. de Jong-Brink)
Support: OKF-Vrije Universiteit, Amsterdam (Onderwijs Kwaliteits Fonds)
Description: Existing software (`Course of Action', `Authorware') will be used to implement `knowledge' as parts of courses in biology and mathematics; the first purpose being to identify gaps in background knowledge of the participants of the courses.
Results: Software has been written, no papers

Physiologically based toxicokinetics

Investigator: Mrs. G.W. van der Molen
Period:1992/09/01 - 1996/09/01
Collaboration: RIVM (W. Slob)
Support: RIVM, Bilthoven
Description: Physiological realistic models for toxicokinetics are formulated in relation with risk assessment for human health problems. This models will be placed in an ecotoxicological context.

Moral argumentation in applied biotechnology

Investigator: Mrs. S. Kasanmoentalib, Mrs. E. Bos
Period: 1992/09/01 - 1996/09/01
Support: USF-Vrije Universiteit, Amsterdam (Universitair Stimulerings Fonds)
Description: Methodological evaluation of scientific information is poorly developed in existing models for moral argumentation and models for technology assessment. This complicates the evaluation of applications of biotechnology. A number of case studies in biotechnology will be used to develop a model for moral argumentation based on the methodological status of empirical background theories. Existing models for moral argumentation and for technology assessment will be critically evaluated.

Analysis of likelihood functions for small samples

Investigator: Mrs. E.J.M.F. Persoon
Period: 1992/03/01 - 1996/03/01
Collaboration: Vrije Universiteit (van Vliet), Leiden University, Theor. Biol (E. Meelis)
Support: PAD-VROM, Den Haag (Platform Alternatieven Dierproeven)
Description: On the basis of computer simulation studies, an effective methodology will be developed to design experiments, to estimate parameter values and to test theories about these values in cases where large sample theory no longer applies. Concrete biological experimental problems are used to evaluate theoretical results.

The methodology of applied biotechnology

Investigator: A.M. van Dommelen
Period: 1992/02/01 - 1997/02/01
Collaboration: George Washington University, Washington (Schaffner)
Support: NWO, Den Haag
Description: Methodological analysis is applied to research on the release of genetically modified organisms and on the human gnome project. This analysis is motivated by observed shortcomings of research in these fields so far.

Modelling of plant growth and reproduction

Investigator: R.J. Bijlsma
Period: 1992/01/01 - 1998/03/01
Collaboration: IBN (H.G.J.M. Koop), University of Utrecht (J.T. Lambers)
Support: IBN-DLO, Wageningen
Description: Modelling of plant growth and reproduction on the basis of the DEB theory for energy uptake and use. Special attention is given to the coupling between energy and mass fluxes and the characterization of biomass measures.

Modelling penicillin production

Investigator: S.A.L.M. Kooijman
Period: 1991/01/01 - 1991/09/01
Collaboration: Gist Brocades (J.A. de Hollander)
Support: Gist Brocades, Delft
Description: The applicability of the DEB theory for optimization of product production is studied, with special emphasis on penicillin.
Results: No papers available

Control of potato cyst nematodes

Investigator: R. van Haren
Period: 1990/10/01 - 1994/10/01
Collaboration: Res. Inst. for Plant Protection, Wageningen
Support: IPO, Wageningen
Description: The DEB theory is applied to potato cyst nematodes (Globodera pallida and G. rostochiensis) to predict population growth on behalf of control programs. Individual bases measurements are used to the estimate parameters values that are relevant for population dynamics.

A philosophical study of natural history in biology

Investigator: Mrs. C.N. van der Weele
Period: 1990/06/01 - 1994/04/31
Collaboration: Open University (P. Sloep)
Support: NWO, Den Haag
Description: In biology, unlike physics, `natural history' is more important then laws and theories in any strict sense. The project is designed to show by philosophical analysis that putatively general, integrative theories of biology are better described as loosely interconnected `local' theories. More specifically, proposals for integration of evolution and developmental theory are studied.

Ethics, methodology and the life sciences

Investigator: W.J. van der Steen
Period: 1990/01/01 - 0000/00/00
Support: FdB-Vrije Universiteit, Amsterdam (Faculteit der Biologie)
Description: Relationships between the life sciences (biology and medicine), philosophy and ethics are charted, first and foremost from a methodological perspective. Major aims are: development of better methodological tools for ethics to facilitate an integration of ethics and the life sciences; development of philosophical tools that suit the purposes of the life sciences. Further, various case studies aim to show how philosophy is best applied to the life sciences.
Results: See list of publications

Physiological energetics of microorganisms

Investigator: P. Hanegraaf
Period: 1990/01/01 - 1997/09/25
Support: Vrije Universiteit, Amsterdam
Description: The transformation of substrates into microbial biomass and inorganic and organic products can be understood terms of simple rules for energetics in combination with mass balances. It leads to accurate descriptions of a wide variety of experimental results for bacteria, yeasts and fungi. Attemps are made to extend the theory to situations of simultaneous limitations of growth.

Data base for botanical collections

Investigator: Mrs. M. Verhaar
Period: 1989/10/15 - 1991/06/01
Collaboration: Vrije Universiteit, Hortus (D. Smit)
Support: FdB-Vrije Universiteit, Amsterdam (Faculteit der Biologie)
Description: Software will be written of construct a database for plant collections, such as present in the hortus botanicus of the Vrije Universiteit.

Kinetics of metals and organic pollutants in mussels

Investigator: R. van Haren
Period: 1989/05/01 - 1990/10/01
Collaboration: RIKZ, Den Haag (J. Schobben, J. van der Meer)
Support: RIKZ-RWS, Den Haag
Description: The model for toxicokinetics is developed that allows for changes in lipid content as described by the DEB theory. This model is used to analyse monitor data from mussels in the Westerschelde, as collected by RIKZ.

Reduction of sludge formation through grazing

Investigator: P.J.M. Bruijn, Mrs. C. Ratsak
Period: 1989/01/01 - 1993/12/15
Collaboration: Vrije Universiteit (Stouthamer, van Verseveld), IMW-TNO (D. Eikelboom)
Support: RWZI 2000 (STOWA-VROM, Utrecht; RIZA-RWS, Lelystad)
Description: The formation of sludge during the aerobic decomposition of organic compounds in urban waste water grows into an environmental problem. In mixed theoretical/experimental research possibilities are studied to graze (bacterial) sludge by ciliates, oligochaetes etc. in order to reduce output. Computer simulations are used to study the dynamics and stability of biomass transfer through controlled food webs.

Reduction of sludge formation through selection

Investigator: E.B. Muller
Period: 1988/10/01 - 1992/10/01
Collaboration: Vrije Universiteit (Stouthamer, van Verseveld), IMW-TNO (Eikelboom)
Support: RWZI 2000 (STOWA-VROM, Utrecht; RIZA-RWS, Lelystad)
Description: The formation of sludge during the aerobic decomposition of organic compounds in urban wastewater grows into an environmental problem. In mixed theoretical/experimental research possibilities are studied to select for micro-organisms with high energy costs for growth and maintenance in order to reduce output.

Dynamic Enery Budgets for the pond snail

Investigator: C. Zonneveld
Period: 1988/07/01 - 1992/06/30
Collaboration: Vrije Universiteit (A. ter Maat, N. de With, G. Ernsting)
Support: BION-NWO, Den Haag
Description: The implications of the Dynamic Energy Budget theory for the pond snail Lynaea stagnalis are tested against experimental data at the level of the individual; this includes aspects of growth, reproduction, starvation, respiration. The pond snail serves as an example of an ectothermic animal, other species will be included as well.

Protandry in butterflies

Investigator: C. Zonneveld
Period: 1988/07/01 - 1994/13/30
Collaboration: Leiden University, Theor. Biol. (J.A.J. Metz)
Support: FdB-Vrije Universiteit, Amsterdam (Faculteit der Biologie)
Description: In temperate regions, adults of most insect species appear in discrete generations. If so, males emerge often a few days before females. The explanation for this is that females normally mate only once, whereas males are capable and willing to mate more than once. To maximize expected mating success, males should be out before the females emerge. The opposing force to an early emergence is the possibility of an untimely death. This standard pattern in not seen in some species of butterflies though, for instance the whites (Pieridae). In this project an explanation is given for the absence of protandry in some species, and the conditions that may favour absence of protandry.

Dynamic Enery Budgets for micro-organisms

Investigator: E. Evers
Period: 1986/09/01 - 1990/08/31
Collaboration: Vrije Universiteit (A.H. Stouthamer, H.W. van Verseveld), IMW-TNO (A.O. Hanstveit, D.M.M. Adema)
Support: IMW-TNO, Delft
Description: A theory for the energy budgets of bacteria and algae will be developed that is consistent with the existing theory for ecothermic animals. Changes in surface area to volume ratios in cells are of importance, in relation to their population dynamics.

Effects of toxicants on microbial degradation of leaf litter

Investigator: Mrs. J. van Wensem
Period: 1986/03/01 - 1990/12/31
Collaboration: Vrije Universiteit (N. van Straalen, H. Verhoef), IMW-TNO (A.O. Hanstveit, D.M.M. Adema, H. Vonk)
Support: IMW-TNO, Delft
Description: A bioassay is developed to quantify the effect of toxic compounds on the microbial degradation of leaf litter, including the contribution of the macro-fauna (isopods) on the process.

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