Elke Zimmer, PhD-Project DEB-1 Supervisors: Tjalling Jager, Bas Kooijman (VU Amsterdam) Co-Supervisor: Virginie Ducrot (INRA, Rennes) Elke Zimmer CREAM startup-meeting Machern, Germany, Department of Theoretical Biology, Vrije Universiteit Amsterdam No text at all DEB-1: Impact of toxic stress on embryogenesis and the consequences for the population level

Elke Zimmer, PhD-Project DEB-1 My background My studies: Marine Environmental Science, Carl-von-Ossietzky Universität Oldenburg, Germany My diploma thesis: Analyzing endocytosis by generalized modeling, Max Planck Institute for the Physics of Complex Systems in Dresden, Germany Recently: Research assistant at TU Dresden, application of GM to dynamics of stress and coping in humans Research interest: learning new ways to describe and understand the dynamics of organisms/ecosystems No text

Elke Zimmer, PhD-Project DEB-1 My project Standard toxicity tests: adults or juveniles BUT: embryogenesis is closely linked to the rest of the life-cycle! Change in embryonic parameters  life-history  population level? DEB Dynamic Energy Budget theory Impact of toxic stress on embryogenesis and the consequences for the population level

Elke Zimmer, PhD-Project DEB-1 Metabolic organization Important life-history traits: reproduction rate, growth, maturation,… Embryo: hatchling size, hatching time & success The change of one trait influences all others!

Elke Zimmer, PhD-Project DEB-1 Standard DEB scheme Constant conditions: DEB parameters invariant during the life-cycle (e.g. maintenance rate per unit of structure) foodfaeces assimilation reserve feeding defecation structure somatic maintenance growth  1-  maturity maintenance maturity offspring maturation reproduction

Elke Zimmer, PhD-Project DEB-1 Standard DEB scheme reserve structure somatic maintenance growth  1-  maturity maintenance maturity maturation Embryo: non-feeding animal Constant conditions: DEB parameters invariant during the life-cycle (e.g. maintenance rate per unit of structure)

Elke Zimmer, PhD-Project DEB-1 Modeling Basic DEB parameters for L. stagnalis (data from INRA, France) DEB for the embryonic development (hatching time, size at birth…)? Simulations: theoretical analysis of toxic effects on different metabolic processes (individual model in Matlab/Octave)  embryonic vs. other life stages Population: first estimations Lotka-Euler equation, later IBM

Elke Zimmer, PhD-Project DEB-1 Parameterization red: ad libitum blue: 50 % green: 25 % Data: Virginie Ducrot and Laurent Lagadic (INRA, Rennes)

Elke Zimmer, PhD-Project DEB-1 Challenges General Understand the most important aspects of 30 years of research on DEB theory to be able to add something new Find the right data to work with DEB (embryonic development) Languages: English and Dutch Decision which experiments I really need to do

Elke Zimmer, PhD-Project DEB-1 Challenges Specific Juvenile growth Hermaphrodite  two reproduction buffers (behavior?) reserves invested per egg trigger for hatching embryo development under toxic stress

Elke Zimmer, PhD-Project DEB-1 Thanks for your attention! Information about DEB: DEB tele course: February to April 2011 DEB symposium: April 2011 in Lisbon Questions?

Elke Zimmer, PhD-Project DEB-1

Example: parameterization Nematode Acrobeloides nanus with different concentrations of Pentachlorobenzene (Alda Álvarez et al, 2006) time cumulative offspring per female Good guess for the mode of action: decrease of ingestion rate  allows estimation of all basic parameters