Hauptinhalt
Topinformationen
22. Systemwissenschaftliches Kolloquium
Wintersemester 2015/16
Das Kolloquium findet nur im Wintersemester jeweils mittwochs von 16:15 bis 18:00 Uhr im Institut für Umweltsystemforschung, Barbarastr. 12, Raum 66/E01 statt.
Programmübersicht
14.10.2015
Dr. Udo Hommen, Fraunhofer Institute for Molecular Biologie and Applied Ecology, Schmallenberg:
Protecting surface waters against plant protection products – regulatory practice and scientific claims.
28.10.2015 Inaugural Lecture (Private Lectureship)
Dr. Marcus Schulz, Osnabrück University:
Meeresmüll trifft auf multivariate Methoden - eine anwendungsbezogene Einführung in statistische Analysen.
11.11.2015
Dr. Antonios Zagaris, Central Veterinary Institute, Wageningen UR Epidemiology, Crisis Organisation and Diagnostics, Lelystad (NL):
Spatiality in ecological and epidemic dynamics.
25.11.2015
Dr. Stephanie Kramer-Schadt, Leibniz-Institut für Zoo- und Wildtierforschung, Berlin:
Landscape-ecological modelling in applied wildlife research.
02.12.2015
Prof. Dr. Hans Bressers, Institute for Innovation and Governance Studies, University of Twente (NL):
Assessment of governance conditions for the implementation of environmental measures.
09.12.2015
Prof. Dr. Johan van de Koppel, Royal Netherlands Institute for Sea Research, Yerseke (NL):
A multidisciplinary approach to pattern formation in ecosystems.
16.12.2015 ## CANCELED ##
Dr.Tobias Wünscher, Zentrum für Entwicklungsforschung, Universität Bonn:
Environmental auctions.
13.01.2016
Prof. Dr. Andreas Deutsch, Zentrum für Informationsdienste und Hochleistungsrechnen, Technische Universität Dresden:
Analyzing emergent behaviour in cellular automaton models of glioma growth and invasion.
20.01.2016
Prof. Dr. Jens Rademacher, Fachbereich 3 Mathematik, Universität Bremen:
A mathematical perspective on striped patterns and critical transitions in an arid ecosystem model.
27.01.2016 ## CANCELED ##
Dr. Luděk Berec, Institute of Entomology, Biology Centre of the Czech Academy of Sciences, Ceské Budejovice (CR):
Infectious diseases, mating, and a bit of Allee effects.
03.02.2016
Dr. Nanda Wijermans, Stockholm Resilience Centre, Stockholm University (SE):
On (agent-based) modelling human decision making in social-ecological systems.
Kurzfassung der Vorträge
14.10.2015
Dr. Udo Hommen, Fraunhofer Institute for Molecular Biologie and Applied Ecology, Schmallenberg
Protecting surface waters against plant protection products – regulatory practice and scientific claims
The impact of plant protection products on non-target organisms in waters is assessed prospectively during the processes of authorisation of active substances and products and retrospectively under the water framework directive. In the prospective assessments the exposure of organisms in small water bodies near agricultural areas is predicted by models and the potential effects are analysed in experiments, while the assessment of the chemical quality of waters is based on monitoring pesticide concentrations mostly in larger waterbodies like rivers and comparing those with standards derived from ecotoxicological tests. In ecotoxicological studies, other stressors than the test item are excluded as far as possible. In contrast to this, monitoring studies have to deal with a large number of variable environmental factors, including exposure to other chemicals, which makes a clear identification of the effects of individual plant protection products often problematic.
Recently a new guidance documents on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters was provided by the European authority for food safety guidance document (EFSA) that picks up on the developments of the last few years. Examples of this are the clearer drafting of a tiered risk assessment and better taking into account of the often very variable exposures. But still, some questions remain unanswered as the formulation of operational protection goals and how the results of ecotoxicological tests can be linked to such goals.
The presentation will introduce the tiered scheme for aquatic risk assessment of plant protection products and will present examples from recent research activities, i.e. the use of mechanistic effect models.
28.10.2015 Inaugural Lecture (Private Lectureship)
Dr. Marcus Schulz, Osnabrück University:
Meeresmüll trifft auf multivariate Methoden - eine anwendungsbezogene Einführung in statistische Analysen
Meeresmüll ist in den letzten Jahren in den umweltwissenschaftlichen Fokus gerückt, da Meeresorganismen durch Fressen von Müllpartikeln und durch Verwicklung in Netzen, Seilen und Bändern geschädigt werden können. Seit einigen Jahrzehnten sind räumlich verteilte Monitoringdaten von Müll in allen Meereskompartimenten erhoben worden. Diese Rohdaten weisen häufig arbiträre Muster auf und entziehen sich daher teilweise einfachen statistischen Analysen.
Multivariate Analyseverfahren wie Cluster- und Faktorenanalysen kamen zum Einsatz, um die Quellen des Mülls zu identifizieren und um räumliche und zeitliche Muster zu entdecken, die wiederum auf Transport- und Verlustprozesse zurückzuführen sind. Clusteranalysen können Müllkategorien und Monitoringstandorte nach ähnlichen zeitlichen Trends oder nach ähnlichen Mengen von Müll gruppieren, je nachdem, ob Ähnlichkeits- oder Unähnlichkeitsmaße verwendet werden. Der gewählte Fusionierungsalgorithmus spielt bei der Gruppierung von Objekten ebenfalls eine wesentliche Rolle. In diesem Beispiel konnten anhand von Clusteranalysen an Strandmülldaten Regionen gegeneinander abgegrenzt und Müllkategorien teilweise sinnvoll gleichen Quellen zugeordnet werden. Faktorenanalysen bündeln Eingangsvariablen wie z.B. Zeitreihen einzelner Strandmüllkategorien zu Faktoren. Anhand von Strandmülldaten sollten mit Hauptachsenanalysen Faktoren extrahiert werden, die man inhaltlich Müllquellen wie Schifffahrt, Tourismus und Fischerei zuordnen kann. Doch selbst mit zusätzlich eingesetzten Rotationsverfahren wurde mittels der Faktorenladungen keine plausible Zuordnung erzielt.
Das Beispiel ‚Meeresmüll‘ zeigt, dass auch komplexe Analyseverfahren nicht immer eindeutige Ergebnisse liefern, die einer inhaltlichen Interpretation standhalten. Eine Alternative stellen künstliche neuronale Netze dar, mit denen z.B. Zeitreihen von Strandmüll simuliert werden können.
11.11.2015
Dr. Antonios Zagaris, Central Veterinary Institute, Wageningen UR Epidemiology, Crisis Organisation and Diagnostics, Lelystad (NL)
Spatiality in ecological and epidemic dynamics
For mathematicians, their understanding of spatial self-organization in ecosystems began with the concept of pattern formation. Since then, theoretical insights have shed light on the complex behavior within spatially extended food webs. And yet, a comprehensive theory of ecological interactions embracing spatiality is missing, with the literature largely focusing on compartment models. Summarily dispensing with spatial processes raises many red flags, particularly in the presence of strong spatial heterogeneity. In this talk, we will first examine spatially extended consumer-resource models, zeroing in on the onset of pattern formation. We will unveil a destabilization mechanism driven by passive spatial processes, discuss its implications, and use it to outline the limitations of spatially homogeneous models. If time allows, we will shift our attention to veterinary epidemic models, presenting a framework that integrates spatial and genetic information for epidemic prediction.
25.11.2015
Dr. Stephanie Kramer-Schadt, Leibniz-Institut für Zoo- und Wildtierforschung, Berlin
Landscape-ecological modelling in applied wildlife research
Conservation and management of rare and endangered species first needs an understanding of their requirements for long-term survival. A complicating factor is that many species of conservation concern tend to be difficult to study because of their elusive behaviour and low population densities. Vice versa, the management of abundant species e.g. for controlling disease spread also covers understanding spatial requirements and fluctuations in population parameters. Here, I will cover a number of examples where different modelling frameworks based on various data sources have been used to address questions of (terrestrial mammal) conservation and management. These models range from tracing origins of migratory species via stable isotopes to habitat analyses and species distribution models via resource selection functions based on telemetry or occurrence data. Individual-based spatially-explicit modelling approaches are used to simulate population dynamics to assess population viability and/ or disease spread.
02.12.2015
Prof. Dr. Hans Bressers, Institute for Innovation and Governance Studies, University of Twente (NL)
Assessment of governance conditions for the implementation of environmental measures
As a result of climate change, it is expected that extreme events influencing water management (flooding or drought) will increase. Early adaptation to this trend of increasing climatic extremes is therefore required. Governance plays a crucial role in the adaptation process particularly in restricting or facilitating the implementation of adaptation measures. In-depth knowledge about the governance setting of a given region and how to influence governance processes is therefore essential in realizing effective adaptation.
This colloquium will present the work of the team of scientists that have been working in the project “Benefits of Governance in Drought Adaptation” (in short: the DROP project), which is included in the INTERREG IVB NWE programme of the European Union. Based on previous work at the University of Twente during the last 15 years, the governance team of DROP has developed a Governance Assessment Tool, through which the governance setting of a given region for planning and realizing adaptation measures can be assessed. Based on this assessment, recommendations can be developed to regional water authorities on how to operate most effectively in this governance context.
The tool has been applied to the six regions in Northwest Europe that were part of the DROP-project: Twente and Salland in the Netherlands, Eifel-Rur in Germany, Brittany in France, Somerset in the United Kingdom, and Flanders in Belgium. However, the Governance Assessment Tool can be, and has been, applied more broadly, to a range of governance contexts for water management and beyond. As such the colloquium may be of interest to a range of stakeholders with an interest in governance conditions for the implementation of measures and the realization of projects, whether that context is about water, more specifically about drought or flooding events, or other environmental issues.
09.12.2015
Prof. Dr. Johan van de Koppel, Royal Netherlands Institute for Sea Research, Yerseke (NL)
A multidisciplinary approach to pattern formation in ecosystems
Most examples of self-organized spatial patterns in ecosystems are based on Turing’s activator-inhibitor principle, where pattern formation is driven by spatial variation in growth conditions. I will highlight a new mechanism of pattern formation in ecosystems that is based on animal movement, and is akin to the Cahn-Hilliard principle for phase separation, known to explain pattern formation in alloys such as steel or bronze. I will reveal using models and experiments that in some ecosystems, both processes can occur simultaneously, and interact to determine the resilience of ecosystems to disturbances and changing environmental conditions.
16.12.2015
Dr.Tobias Wünscher & Dr. Sven Wunder, Zentrum für Entwicklungsforschung, Universität Bonn
Environmental auctions
The number of payments for environmental service schemes (PES) in developing countries has grown more rapidly than in developed countries. Yet, scarce funding among potential service buyers in developing countries arguably makes it even more important to design PES cost-effectively. Tendering conservation contracts is one possible way to improve the cost-effectiveness of PES schemes. However, experience with conservation tenders in developing countries remains limited to a handful of scientifically motivated experimental trials. Larger roll-outs can so far only be found in developed countries, mainly the US and Australia. How different would rolled-out PES tenders perform in developing countries, and would they require distinct design features? Here, we identify specific opportunities and challenges for implementing conservation tenders in developing countries. Conceptually, we examine each implementation step of a tendered PES for typical developing country characteristics. Some may affect the design requirements for successful implementation, both in positive and negative ways, as compared to the typical developed country case. Imperfect markets and information about production systems, high subsistence incomes, high variability in prices and yields, and risk-averse behavior all constitute constraints which conservation tenders may be particularly suited to overcome. Conversely, lack of expertise and infrastructure can hamper tender design and the dissemination of information to potential participants. Also, collective integrity and strong communal leadership can increase the risk of collusion, especially in small-scale programs. Some of these challenges can be dealt with, but solutions unavoidably increase transaction costs which, in turn, may affect scalability. While tenders may reduce poverty alleviation effects when informational rents of service providers are being squeezed, tendered PES programs do not reduce rents to zero under normal circumstances, and they may actually be more equitable in the distribution of rents than alternative payment allocations.
13.01.2016
Prof. Dr. Andreas Deutsch, Zentrum für Informationsdienste und Hochleistungsrechnen, Technische Universität Dresden
Analyzing emergent behaviour in cellular automaton models of glioma growth and invasion
Glioma make up a major part of all malignant brain tumors. Deciphering the principles of glioma growth and invasion is crucial for the development of novel therapy concepts. Of particular interest is the precise regulation of glioma cell migration and proliferation. Mathematical modelling and computer simulation is needed for investigating collective effects as the formation of a glioma invasion front. Here, we demonstrate how cellular automaton models can be used for an adequate description of individual glioma cell behaviour [1]. We will show how analysis of the cellular automaton models allows for prediction of emerging properties (e.g. invasion speed) arising from the „go or grow“ dynamics which is characteristic of glioma cells [2]. Furthermore, we use our models for the interpretation of data from in vitro glioma cancer cell invasion assays [3] and will also demonstrate implications of the „go or grow“ dichotomy for glioma growth and persistence [4].
References:
[1] A. Deutsch, S. Dormann: Cellular Automaton Modeling of Biological Pattern Formation: Characterization, Applications, and Analysis, Birkhäuser, Boston, 2005
[2] H. Hatzikirou, D. Basanta, M. Simon, K. Schaller, A. Deutsch: ‘Go or grow’: the key to the emergence of invasion in tumour progression? Math. Med. Biol., 29, 1, 49-65, 2012
[3] M. Tektonidis, H. Hatzikirou, A. Chauviere, M. Simon, K. Schaller, A. Deutsch: Identification of intrinsic mechanisms for glioma invasion. J. Theor. Biol., 287, 131-147, 2011
[4] K. Böttger, H. Hatzikirou, A. Voss-Boehme, E. A. Cavalcanti-Adam, M. A. Herrero, A. Deutsch: An emerging Allee effect is critical for tumor initiation and persistence, PloS Comp. Biol. 2015
20.01.2016
Prof. Dr. Jens Rademacher, Fachbereich 3 Mathematik, Universität Bremen
A mathematical perspective on striped patterns and critical transitions in an arid ecosystem model
Coming from a mathematical perspective, some aspects of pattern formation and critical transitions will be discussed by way of a model for water-limited arid ecosystems. On sloped terrains, stripe patterns of vegetation aligned in bands has been observed ubiquitously. The appearance, stability, and bifurcations of striped patterns in the model will be discussed. Near onset and in the long wavelength regime, rigorous mathematical analysis is possible. The intermediate regime can be bridged by numerical computations, in particular, numerical continuation for stability boundaries and ramping simulations for critical parameters. This highlights that the resilience of the vegetation bands is larger on steeper slopes, and provides early warning thresholds for critical transitions to vegetation loss.
Mathematically, it can be shown that long wavelength striped patterns are unstable against transverse perturbations and a “Squire theorem” holds for the onset of patterns: unstable modes in the direction of advection dominate. While this naturally leads to striped patterns, stability near onset is a more subtle issue.
This is mainly joint work with Arjen Doelman, Eric Siero (Leiden) and Max Rietkerk, Maarten Eppinga and Koen Siteur (Utrecht), supported by the Complexity Program of the Dutch Science Fund (NWO), and Daniel Wetzel (Bremen).
27.01.2016
Dr. Luděk Berec, Institute of Entomology, Biology Centre of the Czech Academy of Sciences, Ceské Budejovice (CR)
Infectious diseases, mating, and a bit of Allee effects
Infectious diseases can seriously impact both ecology and evolution of their animal hosts. As far as vertically or sexually transmitted diseases are concerned, mating becomes a key player as it mediates both host reproduction and pathogen transmission. While this coupling of reproduction and transmission processes arises naturally in mathematical models of vertically transmitted diseases, it has been entirely neglected in mathematical models of sexually transmitted diseases. In this talk I will present a framework for modeling sexually transmitted diseases that takes the consistency between host reproduction and pathogen transmission into account, and illustrate it with the harmonic mean mating function and a mating function triggering an Allee effect. Using this framework and an evolutionary analysis, I will also address the question of why have parasites promoting mating success have been observed so rarely. Finally, I will talk about the evolution of early male-killers, vertically transmitted bacteria that kill the infected male embryos, and about a potential role of these bacteria in control of insect pests already targeted by the sterile insect technique (the sterile insect technique creates an Allee effect). It turns out that male-killing bacteria may counteract some of the reasons for which the sterile insect technique may fail, and allow for pest eradication where the sterile insect technique alone causes pest suppression only.
03.02.2016
Dr. Nanda Wijermans, Stockholm Resilience Centre, Stockholm University (SE)
On (agent-based) modelling human decision making in social-ecological systems
In understanding of environmental challenges human decision making is crucial to include in our models of social-ecological systems. However, the individual level of human behaviour is often neglected; and when included, we often typically (implicitly) resort to one type of decision making (a form of a bounded rational agent). In this talk I will share some of the ongoing work on 1) incorporating different models/assumptions of human decision making and its impact on our understanding and 2) the exploration of explanations of observable patterns by including the individual level in our models.
