Introduction: Distributed ledger networks, chiefly those based on blockchain technologies, currently are heralding a next-generation of computer systems that aims to suit modern users’ demands. Over the recent years, several technologies for blockchains, off-chaining strategies, as well as decentralised and respectively self-sovereign identity systems have shot up so fast that standardisation of the protocols is lagging behind, severely hampering the interoperability of different approaches. Moreover, most of the currently available solutions for distributed ledgers focus on either home users or enterprise use case scenarios, failing to provide integrative solutions addressing the needs of both.

Methods: Herein, we introduce the OpenDSU platform that allows to interoperate generic blockchain technologies, organised–and possibly cascaded in a hierarchical fashion–in domains. To achieve this flexibility, we seamlessly integrated a set of well conceived components that orchestrate off-chain data and provide granularly resolved and cryptographically secure access levels, intrinsically nested with sovereign identities across the different domains. The source code and extensive documentation of all OpenDSU components described herein are publicly available under the MIT open-source licence at https://opendsu.com.

Results: Employing our platform to PharmaLedger, an inter-European network for the standardisation of data handling in the pharmaceutical industry and in healthcare, we demonstrate that OpenDSU can cope with generic demands of heterogeneous use cases in both, performance and handling substantially different business policies.

Discussion: Importantly, whereas available solutions commonly require a pre-defined and fixed set of components, no such vendor lock-in restrictions on the blockchain technology or identity system exist in OpenDSU, making systems built on it flexibly adaptable to new standards evolving in the future.

In recent years, it has been found that screen content images (SCI) can be effectively compressed based on appropriate probability modelling and suitable entropy coding methods such as arithmetic coding. The key objective is determining the best probability distribution for each pixel position. This strategy works particularly well for images with synthetic (textual) content. However, usually screen content images not only consist of synthetic but also pictorial (natural) regions. These images require diverse models of probability distributions to be optimally compressed. One way to achieve this goal is to separate synthetic and natural regions. This paper proposes a segmentation method that identifies natural regions enabling better adaptive treatment. It supplements a compression method known as Soft Context Formation (SCF) and operates as a pre-processing step. If at least one natural segment is found within the SCI, it is split into two subimages (natural and synthetic parts) and the process of modelling and coding is performed separately for both. For SCIs with natural regions, the proposed method achieves a bit-rate reduction of up to 11.6% and 1.52% with respect to HEVC and the previous version of the SCF.

Kulturelle Bildung – ein Containerbegriff, welcher mit verschiedensten Merkmalen assoziiert ist. Wie verstehen lokale Akteur*innen Kulturelle Bildung, und wie kann dies zur Begriffsschärfung bezüglich der Strukturen, Angebote, Dimensionen und Wirkung Kultureller Bildung beitragen?
Für eine erste Annäherung an diese Frage wurden 34 Akteur*innen aus verschiedenen Sektoren Kultureller Bildung aus der Region und Stadt Coburg in leitfadengestützten Expert*inneninterviews befragt und die Interviews mittels qualitativer Inhaltsanalyse ausgewertet. Die Ergebnisse geben einen Überblick über die Perspektive lokaler Akteur*innen auf die aktuelle Lage Kultureller Bildung in der Stadt und Region Coburg (Oberfranken), auf Wirkpotenziale sowie Vernetzungs- und Förderbedarfe. Der besondere Zeitpunkt der Erhebung (August – Dezember 2020) ermöglicht darüber hinaus Einblicke in die Kulturelle Bildung während der COVID-19 Pandemie, beschreibt diesbezügliche Veränderungen und hinterfragt diese kritisch.  Darüber hinaus setzt die differenziert kategorisierende Analyse von Begriffsverständnissen, Strukturen und Dimensionen aus der Perspektive lokaler Akteur*innen Impulse für zukünftige, auch konturiert quantifizierende Forschung im Feld der Kulturellen Bildung.

Due to increasingly ageing populations and a rising demand on quality of life hip replacement became one of the most common operations in orthopedics and trauma surgery over the last decades and even continues to gain importance. However, in more than 10 percent of cases, loosening of the implanted prosthesis occurs within the first 15 years after surgical implantation. As a result, the prosthesis usually has to be completely replaced in a complex operation which often leads to complications. The later the prosthesis loosening is detected, the more difficult the initial situation for a successful and complication-free prosthesis replacement is. In addition to early diagnosis, it is essential to distinguish between purely mechanical (aseptic) loosening and loosening caused by bacterial infection (septic). Due to a lack of accuracy, conventional diagnostic methods such as projection radiography cannot reliably diagnose loosening in its early stages or detect whether it is associated with the formation of a biofilm in the bone-implant interface.

In this work, we developed a non-invasive ultrasound-based measurement procedure for quantifying the thickness of the layer between the bone and the stem of a hip prosthesis as a correlate to loosening. In principle, it also allows for material characterization of the interface.

The introduced method is based on a well-known analytical model of the reflection of sound waves in a three-layer system being mainly used for characterizing the thickness of thin lubricant films. For the desired medical application of characterizing the bone-implant interface which comes along with rough surfaces, inhomogeneous materials and the impossiblity of reference measurements, we adapted and extended this model and developed suitable data processing algorithms for analyzing the interface.

With respect to determining the layer thickness, the procedure was experimentally validated at different idealized test systems and a more realistic bone-implant system within in the range of approx. 200 µm to 2 mm. Consequently, our procedure is able to quantify the thickness of thin interlayers even at rough, porous and inhomogeneous materials and without a reference measurement.

After further optimization and adaptation, as well as further experimental tests, the procedure offers great potential to significantly improve the diagnosis of prosthesis loosening at an early stage and may also bei applicable to detect the formation of a biofilm.