Search

Building a representative model of a complex dynamical system from empirical evidence remains a highly challenging problem. Classically, these models are described by systems of differential equations that depend on parameters that need to be optimized by comparison with data. In this tutorial, we introduce the most common multi-parameter estimation techniques, highlighting their successes and limitations. We demonstrate how to use the adjoint method, which allows efficient handling of large systems with many unknown parameters, and present prototypical examples across several fields of physics. Our primary objective is to provide a practical introduction to adjoint optimization, catering for a broad audience of scientists and engineers. Multiple parameter estimation techniques are employed to empirically validate theoretical propositions regarding complex systems by discerning relevant free parameters from often scarce experimental data. In this tutorial, the authors provide a beginner's guide to parameter estimation via adjoint optimization, and show its efficiency in prototypical problems across different fields of physics. [ABSTRACT FROM AUTHOR]

The aims of this study were to, first, determine the intracellular aminopeptidase activity (APEi) and second, purify and biochemically characterize one intracellular aminopeptidase enzyme from the phytopathogen fungus Sporisorium reilianum (psrAPEi), the causal agent of head smut in corn. The fungus produced APEi activity in all media cultures evaluated. The psrAPEi was purified by a procedure that involved ammonium sulfate fractionation and four chromatographic steps using an FPLC system (Fast Protein Liquid Chromatography). Results showed an estimated molecular mass of 52.2 kDa. Enzymatic activity was optimal at pH 7.0 and 35 °C and was inhibited by EDTA-Na2, 1,10-phenanthroline, bestatin, and PMSF. This aminopeptidase showed a preference for leucine, arginine, and lysine at the N-position. The Km and Vmax values were 3.72 μM and 188.0 μmol/min, respectively, for l-lysyl-4-nitroanilide. This is the first study to report on intracellular aminopeptidase activity in S. reilianum and the purification and characterization of an intracellular metallo-serine-aminopeptidase (psrAPEi). [ABSTRACT FROM AUTHOR]