Learning a Generative Transition Model for Uncertainty-Aware Robotic Manipulation

Peer reviewedPreprin

Self-Supervised Learning for Precise Pick-and-Place Without Object Model

ACKNOWLEDGEMENT We would like to thank Tamim Asfour for his helpful suggestions and discussions.Peer reviewedPostprin

Extension of the turbulent spot method towards arbitrary reynolds stresses and integral lengths

The paper presents an extension of the Turbulent Spot method which enables to obey the continuity of the fluctuations while producing arbitrarily high anisotropy at the same time. The derivation of the structures is summarized and expressions for their Reynolds stresses and length scales are presented. Finally, the newly derived structures are applied to a turbulent channel flow simulation and compared with other means of turbulence synthesis

Fine-tuning spermidine binding modes in the putrescine binding protein PotF

A profound understanding of the molecular interactions between receptors and ligands is important throughout diverse research, such as protein design, drug discovery, or neuroscience. What determines specificity and how do proteins discriminate against similar ligands? In this study, we analyzed factors that determine binding in two homologs belonging to the well-known superfamily of periplasmic binding proteins, PotF and PotD. Building on a previously designed construct, modes of polyamine binding were swapped. This change of specificity was approached by analyzing local differences in the binding pocket as well as overall conformational changes in the protein. Throughout the study, protein variants were generated and characterized structurally and thermodynamically, leading to a specificity swap and improvement in affinity. This dataset not only enriches our knowledge applicable to rational protein design but also our results can further lay groundwork for engineering of specific biosensors as well as help to explain the adaptability of pathogenic bacteria

The local structure of molecular reaction intermediates at surfaces

A critical review is presented of the results of (experimental) quantitative structural studies of molecular reaction intermediates at surfaces; i.e. molecular species that do not exist naturally in the gas phase and, in most cases, are implicated in surface catalytic processes. A brief review of the main experimental methods that have contributed to this area is followed by a summary of the main results. Investigated species include: carboxylates, RCOO– (particularly formate, but also deprotonated amino acids); methoxy, CH3O–; carbonate, CO3; ethylidyne, CH3C–; NHx and SOx species; cyanide, CN. As far as possible in the limited range of systems studied, a few general trends are identified

Quantitative local structure determination of R,R-tartaric acid on Cu(110): Monotartrate and bitartrate phases

The local adsorption site of the monotartrate and bitartrate species of R,R-tartaric acid deposited on Cu(110) have been determined by scanned-energy mode photoelectron diffraction (PhD). In the monotartrate phase the molecule is found to adsorb upright through the O atoms of the single deprotonated carboxylic acid (carboxylate) group, which are located in different off-atop sites with associated Cu―O bond lengths of 1.92 ± 0.08 Å and 1.93 ± 0.06 Å; the plane of the carboxylate group is tilted by 17 ± 6° off the surface normal. The bitartrate species adopts a ‘lying down’ orientation, bonding to the surface through all four O atoms of the two carboxylate groups, also in off-atop sites. Three slightly different models give comparably good fits to the PhD data, but only one of these is similar to that predicted by earlier density functional theory calculations. This model is found to have Cu―O bond lengths of 1.93 ± 0.08 Å and 1.95 ± 0.08 Å, while the planes of the carboxylate groups are tilted by 38 ± 6° from the surface normal. -------------------------------------------------------------------------------