Thermal Fluctuations of Biomolecules : An Approach to Understand Subdiffusion in the Internal Dynamics of Peptides and Proteins

Auf der Basis von Molekulardynamik-Simulationen werden die thermischen Fluktuationen in den inneren Freiheitsgraden von Biomolekülen, wie Oligopeptiden oder einer Beta-Schleife, untersucht, unter besonderer Beachtung der zeitgemittelten, mittleren quadratischen Verschiebung (MSD). Die Simulationen lassen in einem Bereich von Pikosekunden bis einige zehn Nanosekunden Subdiffusion im thermischen Gleichgewicht erkennen. Mögliche Modelle subdiffusiver Fluktuationen werden vorgestellt und diskutiert. Der zeitkontinuierliche Zufallslauf (CTRW), dessen Wartezeitenverteilung einem Potenzgesetz folgt, wird als mögliches Modell untersucht. Während das ensemble-gemittelte MSD eines freien CTRW Subdiffusion zeigt, ist dies beim zeitgemittelten MSD nicht der Fall. Hier wird gezeigt, dass der CTRW in einem begrenzten Volumen ein zeitgemitteltes MSD aufweist, das ab einer kritischen Zeit subdiffusiv ist. Eine analytische Näherung des zeitgemittelten MSD wird hergeleitet und mit Computersimulationen von CTRW-Prozessen verglichen. Ein Vergleich der Parameter des begrenzten CTRW mit den Ergebnissen der Molekulardynamik-Simulationen zeigt, dass CTRW die Subdiffusion der inneren Freiheitgrade nicht erklären kann. Eher muss die Subdiffusion als Konsequenz der fraktalartigen Struktur des zugänglichen Volumens im Konfigurationsraum betrachtet werden. Mit Hilfe von Übergangsmatrizen kann der Konfigurationsraum durch ein Netzwerkmodell angenähert werden. Die Hausdorff-Dimension der Netzwerke liegt im fraktalen Bereich. Die Netzwerkmodelle erlauben eine gute Modellierung der Kinetik auf Zeitskalen ab 100 ps

Énoncés métalangagiers en contraste :

Cet article se propose d’étudier le discours puriste sur la langue française dans une perspective comparative par l’opposition de deux genres d’interactionnisme discursif. Partant d’un aperçu sur la tradition métalinguistique en France et sur la notion d’aménagement linguistique, nous nous consacrons d’abord aux recherches liées au programme de la linguistique populaire. Dans ce contexte, notre contribution essaie tout d’abord de situer les acteurs du discours puriste et leurs actions verbales sur un axe qui oppose les constructions savantes aux constructions ‘populaires’. Dans le but de définir les lieux communs idéologiques véhiculés dans les énoncés des acteurs puristes, s’exprimant dans des lieux et par des genres de communication différents, les approches de l’analyse de discours (AD) nous serviront de cadre méthodologique. Dans cette optique, l’analyse s’intéresse principalement aux topoï structurant le discours puriste, dans lequel savoirs et représentations méta­linguistiques spécifiques et récurrents constituent un inventaire de réflexions partagées par les puristes.This article considers the purist discourse of French language from a comparative perspective by analyzing the opposition of two discursive genres of metalinguistic interaction. Firstly, the article will be introduced by a discussion of the metalinguistic discourse tradition in France and the field of language planning. Secondly, the folk linguistic research and its interests will be illustrated. Considering the verbalized forms of cognitive representations in linguistic discourse, the focus will be on defining the actor’s opinion of the continuum between an expert and a layperson. The ideologically constructed commonplaces conveyed by purist actors using different communication areas and genres lead to the introduction of discourse linguistics as an appropriate approach within the field of Applied Linguistics. Following this theoretical background, the objective of this paper is to reveal specific topical structures and argumentative layouts in order to gain new insights into the underlying beliefs of purism

Zur Methodenkombination in angewandten diskurslinguistischen Untersuchungen: Ein Beitrag aus Perspektive der romanischen Sprachwissenschaft

Der Beitrag befasst sich mit dem Potenzial der Kombination qualitativer und quantitativer Analyseverfahren in diskurslinguistischen Forschungsarbeiten bei der Arbeit mit sprachvergleichenden Korpora. Ausgehend von den Zielen und Forschungsdesideraten der romanistischen Linguistik versteht sich der Beitrag als Plädoyer für eine disziplinen- und fächerübergreifende Diskurslinguistik sowie die Entwicklung eines forschungsgegenstandsangemessenen Methodenbewusstseins

3D Image Based Structural Analysis of Leather for Macroscopic Structure- Property Simulation

Content: The intrinsic structure significantly influences the mechanical properties of leather. In consequence, knowledge of leather’s hierarchical structure is essential in order to find the most suited leather for specific application. Leather structure based parameters are of major importance for both manufacturing and leather processing industries. In this respect, intensive structure investigations have been subjected in continuous research work. Quantitative image analysis combined with stochastic micro-structure modelling and numerical simulation of macroscopic properties is a promising approach to gain a deeper understanding of complex relations between material’s micro-structure geometry and macroscopic properties. Key ingredient is a reliable geometric description provided by the quantitative analysis of 3D images of the material micro-structures. For leather, both imaging and image analysis are particularly challenging, due to the multi-scale nature of the leather’s micro-structure. Scales in leather are not well separated. Previously, high resolution computed tomography allowed 3D imaging of purely vegetable tanned leather samples at micro- and submicro- scale. Segmentation of leather structure as well as of typical structural elements in resulting image data is however hampered by a strong heterogeneity caused by lower scale structural information. The first method for automatic segmentation of typical structural elements at varying scales combined morphological smoothing with defining and iteratively coarsening regions using the waterfall algorithm on local orientations. It yields a hierarchical segmentation of the leather into coarse and fine structural elements that can be used to analyze and compare the structure of leather samples. Size and shape of the structural elements as well as their sub-structure yield information, e. g. on undulation, branching, thickness, cross-sectional shape, and preferred directions. In order to compare the micro-structure of leather samples from various body parts or even species, the segmentation has to be applicable without extensive pre-processing and parameter tuning. Robustness can be gained by applying smoothing methods that are adapted to the goal of defining image regions by similar local orientation. The challenge is that the space of fiber orientations in 3D is not equipped with an order. Motivated by a recent approach for nevertheless defining erosion and dilation on the sphere, we suggest new definitions for these morphological base transformations on the space of directions in 3D. We present segmentation results for 3D images of leather samples derived by these new morphological smoothing methods. Take-Away: The intrinsic structure significantly influences the mechanical properties of leather. Leather’s hierarchical structure can be analyzed by quantitative 3D image analysis combined with stochastic micro-structure modelling. Segmentation results for 3D images of leather samples derived by new morphological smoothing methods

Avant-propos

En 2008 est paru en France un numéro de Pratiques sous la direction de Guy Achard-Bayle et Marie-Anne Paveau, intitulé Linguistique populaire ?, qui interroge pour la première fois de façon approfondie cette étiquette et le(s) domaine(s) de recherche qu’elle désigne. Le numéro s’appuie sur des travaux, rares en France à cette époque, portant sur l’activité métalinguistique des non-expert·e·s, sur le statut du sujet parlant et sur les questions épistémologiques qui s’ensuivent (Beacco 2004, Ho..

Economic Value of Peer Support Program in German Hospitals

ObjectivesAcknowledging peer support as the cornerstone in mitigating the psychosocial burden arising from the second victim phenomenon, this study assesses the economic benefits of a Peer Support Program (PSP), compared to data of the Resilience In Stressful Events (RISE) program in the US, within the acute inpatient care sector in Germany.MethodsEmploying a Markov model, this economic evaluation analyzes the cost benefits, including sick day and dropout costs, over a 1-year period, comparing scenarios with and without the Peer Support Program from a hospital perspective. The costs were calculated as an example based on a hospital with 1,000 employees. The estimations are considered conservative.ResultsThe anticipated outcomes demonstrate an average cost saving of €6,672 per healthcare worker participating in the Peer Support Program, leading to an annual budgetary impact of approximately €6,67 Mio. for the studied hospital.ConclusionThe integration of a PSP proves economically advantageous for German hospitals, not only preserving financial resources but also reducing absenteeism, and mitigating turnover, thereby enhancing overall patient care

Lysine acetylation regulates moonlighting activity of the E2 subunit of the chloroplast pyruvate dehydrogenase complex in Chlamydomonas

The dihydrolipoamide acetyltransferase subunit DLA2 of the chloroplast pyruvate dehydrogenase complex (cpPDC) in the green alga Chlamydomonas reinhardtii has previously been shown to possess moonlighting activity in chloroplast gene expression. Under mixotrophic growth conditions, DLA2 forms part of a ribonucleoprotein particle (RNP) with the psbA mRNA that encodes the D1 protein of the photosystem II (PSII) reaction center. Here, we report on the characterization of the molecular switch that regulates shuttling of DLA2 between its functions in carbon metabolism and D1 synthesis. Determination of RNA‐binding affinities by microscale thermophoresis demonstrated that the E3‐binding domain (E3BD) of DLA2 mediates psbA‐specific RNA recognition. Analyses of cpPDC formation and activity, as well as RNP complex formation, showed that acetylation of a single lysine residue (K197) in E3BD induces the release of DLA2 from the cpPDC, and its functional shift towards RNA binding. Moreover, Förster resonance energy transfer microscopy revealed that psbA mRNA/DLA2 complexes localize around the chloroplast's pyrenoid. Pulse labeling and D1 re‐accumulation after induced PSII degradation strongly suggest that DLA2 is important for D1 synthesis during de novo PSII biogenesis.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Peer Reviewe