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Peri-operative intrastromal corneal segmentation after creation of corneal cuts based on laser induced optical breakdown: A perspective study
No full textRefractive correction techniques, such as Lenticule Extraction and LASIK, are pivotal in corneal surgery. Precise morphological characterization is essential for identifying post-operative complications, which can be compromised by image noise and low contrast. This study introduces an automated image processing algorithm that integrates non-local denoising, the Sobel gradient method, and Bayesian optimization to accurately delineate lenticule volumes and flap surfaces. Validated on 60 ex vivo porcine eyes treated with the SCHWIND ATOS femtosecond laser, the algorithm demonstrated high accuracy compared to the manual gold standard while effectively reducing variability
CellRex: Software platform for managing biological cell data
No full textThis work introduces the software platform CellRex, a research data management system for laboratories capable of storing, searching, and enriching data with biological metadata. CellRex addresses data management challenges by storing data in an ontology-based directory structure within the filesystem, with metadata saved as JSON files and in a document-oriented SQLite database. The framework, deployed as container services in a software-as-a-service model, features a web-based GUI and API for user interaction and machine-readable access, providing functionalities such as duplicate detection, experiment grouping, and templating. CellRex improves research efficiency and facilitates data reuse, providing a targeted solution for laboratories focused on cell analysis research
Parameter optimization for the infrared curing process of powder coatings using the NAPUBEST prototype and optical simulations
No full textIn line with the energy transition, it is desirable to replace fossil fuels in the curing process of industrial powder coatings. Infrared heating is the considered method here. IR-emitter arrangement in the reflective heating chamber, their geometry and the dwell time of the components are crucial for a successful and efficient process. Process optimization has to consider the optical parameter variation of the powder coating during the procedure. Measurements in the NAPUBEST prototype are compared with optical simulations of the setup to get the simulation parameters in agreement with reality and to provide a foundation for the layout of industrial processes
METHODICAL APPROACH FOR ANALYZING LEARNING PATH FITNESS IN AN AI-BASED ADAPTIVE LEARNING SYSTEM
No full textLearning paths are a cornerstone of many adaptive learning systems, particularly those focusing on adaptive navigational techniques. Evaluating and analyzing these paths is therefore crucial to ensure they effectively support both learners and instructors. For eLearning this process must be highly scalable despite minimal oversight and little to no control over learners’ behavior. Consequently, learning path evaluation should be automated, user-friendly, and precise. However, current research on this topic often emphasizes simulations, performance metrics, or mathematical models, without fully considering the broader, learner-centered aspects necessary for meaningful adaptation. The authors prior findings also indicate that approaches to assessing the suitability of learning paths must be optimized. To address these gaps, this paper presents a potential methodological approach for comprehensive learning path evaluation, aiming to enhance both the precision of adaptive learning systems and the overall learning experience.
Three different algorithms, derived from learning style tendencies and a lecturer recommendation, were analyzed as an illustrative example, although the method itself is not constrained by the form or data basis of these algorithms. The adaptive learning system utilizes various measures to gauge the suitability of a learning path, all gathered through real-time learner feedback. These measures include the correlation between students’ preferred path and each algorithm, referred to as it’s fitness, the alignment between students’ actual adherence to a generated path and their own perception of their study behavior as well as their satisfaction with the path, and the connection between algorithm fitness and both actual performance and perceived performance.
To collect data, students were asked to create their own preferred learning paths by digitally arranging the provided learning elements after receiving an introduction to the respective categories. Once they had completed a topic with a generated learning path, they rated their satisfaction with it and indicated whether they had followed its sequence. They also estimated whether their knowledge level had changed. Learning analytics were then employed to compare these self-reports with students’ actual study behavior. Performance was measured using a rating system, while Spearman’s Rho and Kendall’s Tau served as the main correlation metrics for data analysis.
The results indicate that all three algorithms produce paths more closely aligned with students’ preferred learning paths than the lecturer recommendation, although no single algorithm demonstrated clear dominance. Student satisfaction showed some correlation with the fitness of the generated learning path. Additionally, student ratings appeared to have a slight positive correlation with learning path fitness, whereas self-perceived performance showed no discernible difference. Analysis of the link between actual student behavior and their feedback suggested that students were not reliable in judging whether or not they had followed a learning path.
These findings are consistent with the authors earlier work suggesting the potential effectiveness of the learning path algorithms examined, thus supporting this new methodological approach to analyzing learning paths. The study also provided valuable insights for further development; however, its limited sample size remains a challenge for validation
Historical X ray images selected for UNESCO's Memory of the World Register
No full textThe Deutsches Röntgen Museum” in Remscheid (Germany) is the institution that uniquely and comprehensively explores and documents the life and work of Wilhelm Conrad Röntgen and the impact of his discovery. It preserves a collection of X- ray images taken by W. C. Röntgen during his research. Among them are three images of Röntgen's own hands and those of his wife, Anna Bertha. Three more images show Röntgen's hunting rifle, which he was able to analyze internally by using the new X ray technology. These two series of historical pictures from the years 1895 and 1896 provide an outstanding illustration of the scientific revolution that Röntgen's discovery triggered especially in medicine and in materials science. Therefore, his discovery of X-rays ranks among the most groundbreaking scientific achievements of modern times. In April 2025 those very first recorded X ray photographs were added on the UNESCO Memory of the World Register. The corresponding public ceremony took place on September 10 2025 in Röntgen ´ s birth town Remscheid. Representatives of the German UNESCO Commission, of politics, and of the German Röntgen Society were present UNESCO is thus honoring not only Röntgen's groundbreaking discovery of X rays, but also the cultural, scientific, and technological implications of his early radiographs. The "Deutsches Röntgen Museum" presents six famous historical X-ray documents to the public, which are now part of UNESCO ´ s Memory of the World Register
Optik-Simulation für die Energiewende am Beispiel eines industriellen Infrarot-Heizofens
No full textIm Rahmen der Energiewende sollen fossile Brennstoffe auch im Heizofen einer industriellen Pulverlackbeschichtung ersetzt werden. In der Stahlindustrie ist die Infrarottrocknung von ebenen Stahlband-Oberflächen ein bereits seit Jahren bewährtes Verfahren. Pulverlack-Beschichtungen werden jedoch oft auf komplexe Geometrien aufgetragen, bei denen eine Verschattung die Effizienz der Infrarot-Aushärtung mindert. Die Anordnung der Infrarotstrahler in der reflektierenden Heizkammer, deren Geometrie und die Verweilzeit der Bauteile sind daher die Schlüssel für erfolgreiche Prozesse. Zur Verfahrensoptimierung müssen zudem die optischen Parameter der Pulverlacke während des Prozesses bekannt sein, um die nötige Strahlungsleistung an Bauteile und unterschiedliche Lacke anpassen zu können. Messungen in der NAPUBEST-Prototypanlage werden daher mit optischen Simulationen des Aufbaus abgeglichen, um die Simulationsparameter an die Messergebnisse anzupassen und damit die Grundlage für die Auslegung von industriellen Prozessen zu gewährleisten. Hierbei wird Infrarotstrahlung mehrerer Wellenlängen berücksichtigt, um in unterschiedlichen Ofenzonen benötigte Aufheiz- und Haltephasen zu verwirklichen.Poste
Human cerebral organoids model tumor initiation and infiltration in an autologous astrocyte-supported setting
No full textEfforts to efficiently target brain tumors are constrained by the dearth of appropriate models to study tumor behavior towards treatment approaches as well as potential side effects to the surrounding normal tissue. We established a reproducible cerebral organoid model of brain tumorigenesis in an autologous setting by overexpressing c-MYC, a common oncogene in brain tumors. GFP+/c-MYChigh cells were isolated from tumor organoids and used in two different approaches: GFP+/c-MYChigh cells co-cultured with cerebral organoid slices or fused as spheres to whole organoids. GFP+/c-MYChigh cells used in both approaches exhibited tumor-like properties, including an immature phenotype and a highly proliferative and invasive potential. We demonstrate that the latter is influenced by astrocytes supporting the GFP+/c-MYChigh cells while X-ray irradiation significantly kills and impairs tissue infiltration of GFP+/c-MYChigh cells. In summary, the model represents major features of tumorous and adjacent normal tissue and may be used to evaluate appropriate cancer treatments
Strahlungsmessungen beim Erstflug des Stratosphärenballon-Experiments ASTRABAX
No full textDer erste von drei geplanten Ballonflügen beim Aschaffenburger Stratosphären-
Ballon-Experiment („ASTRABAX“) startete im Oktober 2024 in Bad Pyrmont und
erreichte eine Flughöhe von fast 35 km. Der Schwerpunkt der physikalischen
Experimente lag auf der Vermessung des UV-C-Spektralbereichs mit einem
Miniatur-Spektrometer und der Strahlungsdosimetrie mit einem Geigerzähler
Optik-Simulation für die Energiewende am Beispiel eines industriellen Infrarot-Heizofens
No full textUm fossile Brennstoffe in der industriellen Pulverlackbeschichtung zu ersetzen, kann Infrarottrocknung eingesetzt werden. Für komplexe Geometrien, bei denen eine Verschattung die Effizienz der Infrarot-Aushärtung mindert, sind die Anordnung der Infrarotstrahler in der reflektierenden Heizkammer, deren Geometrie und die Verweilzeit der Bauteile die Schlüssel für erfolgreiche Prozesse
Praxisbezogene Lehre mit EMPAMOS motivierend gestalten
No full textDas Lehrmodul "User Experience" nutzt die EMPAMOS-Methode, um eine praxisorientierte, motivierende Hochschullehre zu gestalten. Unter Einbeziehung von Studierenden, Lehrenden und Didaktiker*innen, zielt das Modul darauf ab, durch problemorientiertes Lernen die Theorie-Praxis-Integration zu stärken. Die Beteiligung der Studierenden am Prozess der Lehrkonzeption ermöglicht es, mit Hilfe von EMPAMOS Lernhindernisse effektiv zu identifizieren und kreative Lösungen zu entwickeln, die das Engagement und die Motivation der Studierenden steigern. Praxisnahe Aufgabenstellungen des Unternehmenspartners, unterstützt durch Übertragung der EMPAMOS-Spielelemente in den Lehr-/Lernkontext fördern die aktive und selbstständige Teilnahme der Studierenden