Zelluläre Verteilung und Einfluss von rtPA und Hypothermie auf die Calpainaktivität bei zerebraler Ischämie/Reperfusion

Charakterisierung der Protease Calpain und ihres zellulären Verteilungsmusters in Abhängigkeit von der Reperfusionsdauer. Steigender Anteil nicht-neuronaler Zellen, v.a. Endothelzellen und Mikroglia, mit zunehmender Dauer. Größte Fraktion stellen die Neuronen dar. Desweiteren Einfluß von rtPA und Hypothermie auf Calpainaktivität. rtPA führt dosisunabhängig nicht zu erhöhter Calpainaktivität, Hypothermie verringert die Aktivität signifikant, ebenso Kombination aus rtPA/Hypothermie

Fractional covers of hypergraphs with bounded multi-intersection

Fractional (hyper-)graph theory is concerned with the specific problems that arise when fractional analogues of otherwise integer-valued (hyper-)graph invariants are considered. The focus of this paper is on fractional edge covers of hypergraphs. Our main technical result generalizes and unifies previous conditions under which the size of the support of fractional edge covers is bounded independently of the size of the hypergraph itself. We show how this combinatorial result can be used to extend previous tractability results for checking if the fractional hypertree width of a given hypergraph is ≤k for some constant k. Moreover, we show a dual version of our main result for fractional hitting sets

Semantic Width and the Fixed-Parameter Tractability of Constraint Satisfaction Problems

Constraint satisfaction problems (CSPs) are an important formal framework for the uniform treatment of various prominent AI tasks, e.g., coloring or scheduling problems. Solving CSPs is, in general, known to be NP-complete and fixed-parameter intractable when parameterized by their constraint scopes. We give a characterization of those classes of CSPs for which the problem becomes fixed-parameter tractable. Our characterization significantly increases the utility of the CSP framework by making it possible to decide the fixed-parameter tractability of problems via their CSP formulations. We further extend our characterization to the evaluation of unions of conjunctive queries, a fundamental problem in databases. Furthermore, we provide some new insight on the frontier of PTIME solvability of CSPs. In particular, we observe that bounded fractional hypertree width is more general than bounded hypertree width only for classes that exhibit a certain type of exponential growth. The presented work resolves a long-standing open problem and yields powerful new tools for complexity research in AI and database theory.Comment: Full and extended version of the IJCAI2020 paper with the same titl

Modelling and model assessment of grid based Multi-Energy Systems

Two main strategies should be implemented to decarbonise the energy sector: substituting fossil fuels with renewable energies, and increasing system efficiency. Both strategies pose challenges for today's energy systems and their operators, because renewable energy is mainly decentralized, not always predictable, and introduces a degree of volatility into grids. Multi-energy systems, which incorporate multiple energy sectors, allow flexibility options to be used across energy carriers and thus further increase system flexibility. In addition, these multi-energy systems can also improve the overall energy efficiency. They enable cascaded energy use and allow for seasonal storage between different energy carriers. A comprehensive system modelling framework should consider all profound interactions between relevant system control variables. The aim of this proposed paper is to show the correlation between major aspects of grid based MES and how they can be combined in a system modelling framework