Talks
Invited Talks
 
  * Lower Bounds for Algorithmic Meta Theorems, Logic Colloquium 2009, Annual Meeting of the Association for Symbolic Logic, 2009.
  * Graph Searching Games, Games Spring School 2009, organised by the ESF network Games for Design and Verification, 2009.
  * Algorithmic Meta-Theorems, International Workshop on Parameterized and Exact Computation (IWPEC), 2008.
  * Complexity of First- and Monadic Second-Order Logic, Spring School of the ESF network Model Theory (MODNET), 2008.
  * Graph Searching Games, Fall School on algorithmic graph minor theory, organised by the graduate school "Methods for Discrete Structres", Berlin, 2007.
  * (Finite) Model Theory of Trees and Tree-Like Structures, Workshop on "Finite and Algorithmic Model Theory", Durham, UK, 2006.
  * Approximation through Logic, Logic Colloquium, Annual meeting of the Association for Symbolic Logic, Athens, Greece, 2005.
  * Expressive Equivalence of Least and Inflationary Fixed-Point Logic, Colloquium Logicum / PhD Colloquium, Münster, Germany, 2002.
Talks at Conferences
 
  * On the Parameterised Intractability of Monadic Second-Order Logic, International Conference on Computer Science Logic (CSL), 2009.
  * On Datalog vs. LFP, International Coloquium on Automata, Languages and Programming (ICALP), 2008.
  * Locally Excluding a Minor, IEEE Symposium on Logic in Computer Science (LICS), 2007.
  * Digraph Measures: Kelly Width, Games, and Orderings, ACM-SIAM Symposium on Discrete Algorithms (SODA), 2007.
  * Approximation Schemes for First-Order Definable Optimisation Problems, IEEE Symposium on Logic in Computer Science (LICS), 2006.
  * Backtracking Games, International Colloquium on Automata, Logic, and Programming (ICALP), 2004.
  * An Alternative Semantics for Partial Fixed-Point Logic, Conference of the European Association for Computer Science Logic (CSL), 2002.
  * Expressive Equivalence of Least and Inflationary Fixed-Point Logic, IEEE Symposium on Logic in Computer Science (LICS), 2002.
  * Inflationary Fixed Points in Modal Logic, Conference of the European Association for Computer Science Logic (CSL), 2001.
  * Query-Languages for Constraint Databases: First-Order Logic, Fixed-Points, and Convex Hulls, International Conference on Database Theory (ICDT), 2001.
  * Fixed-Point Query Languages for Linear Constraint Databases, 19th ACM Symposium on Principles of Database Systems (PODS), 2000.
  * Descriptive Complexity Theory for Constraint Databases, Conference of the European Association for Computer Science Logic (CSL), 1999.
Departmental Seminar
 
  * Computing Excluded Minors, University of Leeds, Department of Pure Mathematics, Logic Seminar, Leeds, UK, 25.2.2009.
  * Graph Searching Games, Departmental Seminar, University of Durham, Durham, UK, 25.2.2008.
  * Graph Searching Games, Departmental Seminar, Royal Holloway, University of London, Egham, UK, invited by Prof. Gutin, 12.2.2008.
  * Digraph Decompositions, Oxford University Computing Laboratory, invited by Prof. Gottlob, Oxford, UK, 25.5.2006.
  * Graph Decompositions and Applications, Short Course am Isaac Newton Institute for Mathematical Sciences, Cambridge, 25.4., 27.4., 2.5., 4.5.2006.
  * Approximation Schemes for First-Order definable Optimisation Problems, Isaac Newton Institute for Mathematical Sciences, Cambridge, 4.4.2006.
  * DAG-Decompositions and Parity Games, European Graduate School “Combinatorics, Geometry, Computation”, TU Berlin, 13.2.2006.
  * DAG-Decompositions and Parity Games, Mathematical Institute, Warsaw University, invited by Prof. Niwinski, 18.11.2005.
  * DAG-Decompositions and Parity Games, Seminarvortrag an der Graduiertenschule “Mathematical Logic and Applications”, Albert-Ludwigs-Universität Freiburg, invited by Prof. Lausen, 5.12.2005.
  * Fixed-Point Logics and Inductive Definitions, Seminarvortrag an der Graduiertenschule “Mathematical Logic and Applications” Albert-Ludwigs-Universität Freiburg, invited by Prof. Flum, 28.6.2004.
  * Kleinste und Inflationäre Fixpunktlogik, University of Bonn, invited by Prof. Köpke, 20.1.2004.
  * Once Upon a Time in the West, “Logic and Semantics Seminar”, University of Cambridge, invited by Dr. Dawar, 29.5.2003.
  * Least and Inflationary Fixed-Point Logic, University of Athens, invited by Professor Moschovakis, 5.10.2001.
Workshops
 
  * Dominating Sets and Network Centres in Nowhere-Dense Classes of Graphs, Workshop Algorithmic Graph Theory, Warwick, 2009.
  * On the fixed-parameter intractability of monadic second-order logic, AlMoTh-Seminar, Dortmund 2009.
  * Logical Methods in Graph Minor Theory, Workshop on Graph Minors, BIRS, Banff, Canada, 2008.
  * Locally Excluded Minors, Dagstuhl-Seminar on parameterized complexity, 2007.
  * Locally Excluding a Minor, AlMoTh-Seminar, Aachen, 2007.
  * Digraph Decompositions, Workshop on Graph Searching, Theory, and Applications, Anogia, Kreta, 2006.
  * DAG-Width and Parity Games, AFM-Seminar, Aachen, 2006.
  * Backtracking Games, Annual Meeting of the EU Training- and Research Network “Games and Automata for Synthesis and Validation (GAMES)”, Bordeaux, France, 2006.
  * Backtracking Spiele, AFM-Seminar, Berlin, 2004.
  * Once Upon a Time in the West, Annual Meeting of the EU Training- and Research Network “Games and Automata for Synthesis and Validation (GAMES)”, Vienna, 2003.
  * Generalising Automaticity to Modal Properties of Finite Structures, AFM-seminar, Aachen, 2002.
  * Least vs. Inflationary Fixed-Point Logic, Workshop “Parameterised Complexity”, AFM-seminar, Freiburg, 2001.
  * Fixed-Point Logics on Constraint Databases - Model-Theoretical vs. Operational Semantics, AFM-seminar, Mainz, 2001.
  * View-Based Query Processing, Workshop "Semi-Structured Data Models", AFM-Seminar, 2000.
  * Fixed-Point Query Languages for Linear Constraint Databases, Workshop on Finite Model Theory, CIRM, Luminy, Marseille, Frankreich, 2000.
  * Descriptive Complexity Theory for Constraint Databases, Workshop on Finite Model Theory and its Applications, LICS 1999, Trento, Italien, 1999.
  * Query Safety with Constraints, Workshop "Spatial Databases", AFM-Seminar, Mainz, 1999.