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Curvature perception of mesenchymal cells on mesoscale topographies
Get PDFCells can sense geometrical cues with sizes of several tens of micrometers in their vicinity. Recent in vitro studies show that cells can adapt their shape, align along specific directions, or regulate other cellular functions when grown on surfaces with curvatures larger than their size. Although possible mechanisms for such responses like the alignment along axial cues have been suggested, a detailed understanding of the involved cellular processes remains open. This work addresses this gap by systematically investigating mesenchymal cell and nucleus orientation responses using a low‐cost model surface platform, the CurvChip. Using an array of cylindrically curved topographies with radii of curvatures ranging from tens to hundreds of micrometers, the contact guidance response of cells and nuclei is quantified in dependence on substratum curvature and manipulation of cytoskeletal components. Results suggest a desired perceived curvature for the investigated cells, and a very sensitive and robust curvature perception mechanism, as the effect of pharmacological manipulation of cytoskeletal components is relatively small. Furthermore, a comparison with previously published work strengthens the hypothesis of an involvement of the nucleus in the cell response to three‐dimensional (3D) curvatures
Direct current electrical fields inhibit cancer cell motility in microchannel confinements
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The capability of cells to sense and respond to endogenous electrical fields plays a crucial role in processes like nerve regeneration, wound healing, and development. In vitro, many cell types respond to electrical fields by migrating along the corresponding electrical field vectors. This process is known as galvano- or electrotaxis. Here we report on the combined impact of micro-confinements and direct current electrical fields (dcEFs) on the motility of MDA-MB-231 human breast cancer cells using a self-developed, easy-to-use platform with microchannels ranging from 3 μm to 11 μm in width and 11 μm height. We found that MDA-MB-231 cells respond to exogenous electrical fields ranging from 100 mV mm^{-1} to 1000 mV mm^{-1} with altered cell motility depending on the confinement size. Our data show an overall inhibited galvanotaxis in confinements, while in contrast an enhancing effect in unconfined galvanotaxis is found. The application of direct current electrical fields to microchannels not only caused a reduction in migration speed but also decreased the number of permeating cells. By applying 1000 mV mm^{-1}, single-cell permeation could be prevented in confinements of 5 μm and smaller
Digital strategy patterns for next intelligent systems and services
No full textThe introduction of intelligent technologies is shaping the era of digital transformation, while companies face the challenge of evolving in a dynamic environment. Intelligent systems and services are the target of many current digitalization efforts and are part of this digital transformation. Artificial intelligence in particular acts as a key driver of digitalization and has a strong influence on new opportunities for shared value creation. This article presents digital strategy patterns that facilitate the implementation of digital strategies and the effective integration of new technologies in companies. The motivation stems from the need to prepare for the upcoming wave of intelligent systems and services and to develop innovative solutions. The methodology is based on the development of a pattern catalog that supports the implementation of digital strategies. The Digital Strategy Patterns enable organizations to combine digital strategies and artificial intelligence. The findings emphasize the key role of artificial intelligence and offer a structured approach to overcoming future challenges in corporate development
Longer days, better performance? The impact of all-day primary schools in Germany
Get PDFThis paper investigates the effects of voluntary all-day programs in German primary schools on student outcomes. To address selection bias, we use federal construction subsidies as an instrument for all-day school expansion. The program significantly increased all-day school attendance. However, second-stage results are mixed and suffer from statistical imprecision. While no significant effects are found on test scores or math grades, there are positive impacts on German grades and academic track attendance after primary school. Results indicate that all-day programs improve student satisfaction and reduce bullying; yet, we find no evidence of a reduction in educational inequality
Kurz innehalten : wie man in Teams Reflexionen nutzt, um achtsamere Entscheidungen zu treffen
No full textReflexion wird oft als eine Retrospektive, eine Art Rückschau, verstanden. Lotte Svalgaard, Wirtschaftspsychologin aus Dänemark, hält es hingegen für viel effektiver, bereits während eines Team-Prozesses zu reflektieren, damit wir unsere dysfunktionalen Verhaltensmuster und Routine-Mechanismen nicht wiederholen. ZOE-Redakteur Arjan Kozica sprach mit der Autorin von „The Elephant in the Room“ über die Kraft der Reflexion „mitten im Geschehen“
Enhancing transparency in space metrics use : insights from an initial study
No full textSoftware has become a key component in spacecraft development. Due to the size and complexity of spacecraft development projects, multiple project stakeholders need to coordinate and exchange development data that must be integrated to provide a big picture. In this context, metrics as for instance defined in the standards such as the European Cooperation for Space Standardization (ECSS) are important. To provide benefits, transparency and clear information regarding the selection and use of software metrics is critical. A lack of transparency and comprehensibility of the process for selecting and collecting key figures by the actors can lead to risks, e.g., important data is not collected or is collected incorrectly. In this paper, to support the streamlined AENEAS measurement tool chain, we developed a tool that helps manage and configure measurement packages that include agreed metrics to be collected in spacecraft development projects. To evaluate the tool, we populated it with 43 metrics from the ECSS-Q-HB-80-04A standard and used it in a case study within a student project. The case study revealed that while the tool facilitated the selection and definition of project metrics, its overall usefulness and clarity received mixed reviews, indicating the need for further improvements
Towards generating compliance action plans : a discussion of needs and opportunities
No full textEnsuring compliance with industry standards and regulations is a critical challenge in software and systems engineering, particularly in domains such as automotive or aerospace in which adherence to standards is mandatory. Compliance checking is often manually connected, e.g., through reviews based on project-specific rules, which is a costly process. This paper proposes a structured, tool-supported approach to compliance analysis. The proposed approach is based on providing a computable reference model, which lays the foundation for the tailoring of project-specific processes, and an automated analysis of the degree of implemented compliance-relevant activities. A proof of concept was is presented, which includes the development of an ECSS-based reference model for software systems engineering, which was developed in close collaboration with practitioners from the aerospace domain. Based on this reference model, the process management tool Stages was used to provide means to generate assessments and action plans. To demonstrate the concept, an exemplary systems development process was modeled and analyzed, which allowed us to identify missing elements in the planed project activities
On the derivation of quality assurance plans from process model descriptions
No full textIn domains such as aerospace, automotive, and medical devices, high-quality software is key due to the critical nature of these applications and the low margin for failure. Ensuring the quality of software is essential to prevent potentially catastrophic outcomes. In this paper, we present an approach to derive quality assurance plans from well-defined process models. Utilizing the GQM model, we derive quality requirements and metrics based on a process example, which we realize in the process management tool Stages. Based on the exemplary realization, we simulate 100 projects to provide data used in a recommendation system that enriches the process model such that quality assurance plans including the metrics of interest can be generated from the process model. Our findings show that, given sufficient data is available, context-specific quality assurance plans can be generated and which particular steps have to be taken to realize the overall concept in the studied tool
Coupled finite element model of the middle and inner ear as virtual test environment for stapes surgery
Get PDFIn order to evaluate the performance of different types of middle‐ear prostheses, a model of human ear was developed. The model was created using finite element (FE) method with the ossicles modeled as rigid bodies. First, the middle‐ear FE model was developed and validated using the middle‐ear transfer function measurements available in literature including pathological cases. Then, the inner‐ear FE model was developed and validated using tonotopy, impedance, and relative BM motion level curves from literature. Both models are based on preexisting research with some improvements and were combined into one coupled FE model. The stapes in the coupled FE ear model was replaced with a model of a stapes prosthesis to create a reconstructed ear model that can be used to estimate how different types of stapes protheses perform relative to each other as well as to the natural ear. The influence of the diameter of the prosthesis as well as the influence of the sealing and opening of the gap in the footplate were investigated along with different measures such as maximum basilar membrane displacement, intracochlear pressure, pressure in scala vestibuli, oval and round window volume displacements, and prosthesis displacement. This will help in designing new innovative types of stapes prostheses or any other type of middle‐ear prostheses, as well as to improve the ones that are already available on the market
Entscheidend ist eine vernetzte IT-Infrastruktur
No full textDie Herausforderung ist groß: Um eine bundesweite gemeinsame Dateninfrastruktur für Forschungsprojekte in Hausarztpraxen aufzubauen, müssen regionale Infrastrukturen innerhalb der Netze geschaffen werden. Erste Erfolge gibt es bereits