University of Potsdam

About: University of Potsdam is a education organization based out in Potsdam, Germany. It is known for research contribution in the topics: Population & Computer science. The organization has 9629 authors who have published 26740 publications receiving 759745 citations. The organization is also known as: Universität Potsdam.

Metabolomic and transcriptomic stress response of Escherichia coli

Abstract: Environmental fluctuations lead to a rapid adjustment of the physiology of Escherichia coli, necessitating changes on every level of the underlying cellular and molecular network. Thus far, the majority of global analyses of E. coli stress responses have been limited to just one level, gene expression. Here, we incorporate the metabolite composition together with gene expression data to provide a more comprehensive insight on system level stress adjustments by describing detailed time-resolved E. coli response to five different perturbations (cold, heat, oxidative stress, lactose diauxie, and stationary phase). The metabolite response is more specific as compared with the general response observed on the transcript level and is reflected by much higher specificity during the early stress adaptation phase and when comparing the stationary phase response to other perturbations. Despite these differences, the response on both levels still follows the same dynamics and general strategy of energy conservation as reflected by rapid decrease of central carbon metabolism intermediates coinciding with downregulation of genes related to cell growth. Application of co-clustering and canonical correlation analysis on combined metabolite and transcript data identified a number of significant condition-dependent associations between metabolites and transcripts. The results confirm and extend existing models about co-regulation between gene expression and metabolites demonstrating the power of integrated systems oriented analysis.

Towards adaptive classification for BCI.

Abstract: Non-stationarities are ubiquitous in EEG signals. They are especially apparent in the use of EEG-based brain–computer interfaces (BCIs): (a) in the differences between the initial calibration measurement and the online operation of a BCI, or (b) caused by changes in the subject's brain processes during an experiment (e.g. due to fatigue, change of task involvement, etc). In this paper, we quantify for the first time such systematic evidence of statistical differences in data recorded during offline and online sessions. Furthermore, we propose novel techniques of investigating and visualizing data distributions, which are particularly useful for the analysis of (non-)stationarities. Our study shows that the brain signals used for control can change substantially from the offline calibration sessions to online control, and also within a single session. In addition to this general characterization of the signals, we propose several adaptive classification schemes and study their performance on data recorded during online experiments. An encouraging result of our study is that surprisingly simple adaptive methods in combination with an offline feature selection scheme can significantly increase BCI performance.

How to Make over 20% Efficient Perovskite Solar Cells in Regular (n-i-p) and Inverted (p-i-n) Architectures

Abstract: Perovskite solar cells (PSCs) are currently one of the most promising photovoltaic technologies for highly efficient and cost-effective solar energy production. In only a few years, an unprecedented progression of preparation procedures and material compositions delivered lab-scale devices that have now reached record power conversion efficiencies (PCEs) higher than 20%, competing with most established solar cell materials such as silicon, CIGS, and CdTe. However, despite a large number of researchers currently involved in this topic, only a few groups in the world can reproduce >20% efficiencies on a regular n–i–p architecture. In this work, we present detailed protocols for preparing PSCs in regular (n–i–p) and inverted (p–i–n) architectures with ≥20% PCE. We aim to provide a comprehensive, reproducible description of our device fabrication protocols. We encourage the practice of reporting detailed and transparent protocols that can be more easily reproduced by other laboratories. A better reporting sta...

Chokeberry (Aronia melanocarpa) - A review on the characteristic components and potential health effects.

Abstract: The intention of this review is to contribute to a better understanding of the potentials of the nutritional contribution of Aronia berries (Aronia melanocarpa). The paper gives a short background to their botanical classification and cultivation practice, going in detail to describe the chemical composition of the berries. The emphasis is laid thereby upon the phenolic constituents. The paper finally gives a short resume of their beneficial effects in biological systems in vitro, in animals, and in humans, thus underlining their medicinal potential.