Eberhardt, P. | Search bioRxiv

bioRxiv2024

Field size as a predictor of "excellence." The selection of subject fields in Germany's Excellence Initiative.

We investigate the selection of subject fields in Germanys "excellence initiative," a two-phase funding scheme administered by the German Research Foundation (DFG) from 2005 to 2017 to increase international competitiveness of scientific research at German universities. While most empirical studies have examined the "excellence initiatives" effects at the university level ("elite universities"), we focus on subject fields within universities. Based on both descriptive and logistic regression analyses, we find that the "excellence initiative" reveals a stable social order of public universities based on organizational size, that field selection is biased toward those fields with many professors and considerable grant funding, and that funding success in the second phase largely follows decisions from the first phase. We discuss these results and suggest avenues for future research.

scientific communication and education↗

bioRxiv2020

Temperature Dependence of the Krokinobacter rhodopsin 2 Kinetics

Here we applied target analysis to a temperature dependent flash photolysis dataset of the light-driven sodium ion pump Krokinobacter rhodopsin 2 (KR2) at sodium pumping conditions. With an increase in temperature from 10 - 40 {degrees}C, the overall photocycle duration was accelerated by a factor of six, while single transitions like the L to M transition increased by a factor of 40. Using kinetic modeling with the Eyring constraint as well as spectral corrections on the datasets the spectral position as well as the equilibria of the different photointermediates could be resolved. The results provide further insight into KR2s photocycle and energetics. STATEMENT OF SIGNIFICANCEKR2 is the most prominent member of the new class of non-proton cation pumps, as it represents an interesting new optogenetic tool. Despite widespread biophysical investigations, the molecular mechanisms of light-induced sodium pumping in KR2 are still not sufficiently understood. Therefore, an expanded set of thermodynamic parameters is essential for a complete picture. Our study of the KR2 photocycle shows that different steps in the photocycle are affected differently by temperature changes. Rigorous data analysis provides strong evidence that the transient states observed in time-resolved experiments represent rather equilibria between the different photocycle intermediates than pure intermediates. Gaining access to the dynamics and energetics of KR2 helps to answer long standing open questions concerning the molecular mechanism of cation pumping.

biophysics↗