https://hst.opus.hbz-nrw.de

Concepts for a cost-efficient, additively manufactured WR90 coaxial waveguide transition

Marius Falk; Simon Müller; Volker Lücken; Andreas R. Diewald — Tue, 27 Jan 2026 11:53:58 +0100

This publication focuses on the production of low-cost prototypes of coaxial-waveguide transitions (CWTs) that achieve the performance level of industrial WR90 and WR187 CWTs. The assembly consists of a specially designed coupling element in stripline technology that merges into an SMA connector. It is embedded into a 3D printed housing treated with a metallic surface finishing to achieve compatibility with hollow waveguides. In the first part of this study, a copper spray varnish is used to create a conductive surface on the device under test (DUT). After assembly of the prototypes, network parameters will be extracted for one pair of transitions by carrying out a set of 2-port measurements. The individual performance of a singular DUT is then deembedded by using reference measurements of commercial-grade waveguides. This analysis shows that also S-parameter extraction on connectors with a poor transition is valid. Subsequently, the procedure for the developed WR90 CWT is applied to a WR187 waveguide standard, again followed by a performance analysis. The procedure briefly addresses the modified parameters and illustrates the results as S-parameters. A comparative analysis of the measurement results for each deembedded WR90 and WR187 prototype respectively, indicates a better performance for larger waveguide standards. In consistency with this observation, larger relative tolerances in manufacturing and difficulties in controlling a uniform metallization process are identified as the limiting factors of miniaturization. In the second part of this work, an alternative concept utilizing aluminum coating and a segmented manufacturing approach is developed, targeting reduced insertion loss but keeping the mechanical tolerance level. The redesign is based on the geometry of the prior WR90 prototype, but forming a plug-in kit with each body segment being clad in multiple thin layers of aluminum foil. The measurement results of these samples reveal the effects of increased conductivity and reduced irregularities in terms of significantly improved reflection and transmission parameters. The DUTs investigated in the third part of this work again originate from the initially manufactured variants. To investigate the effects of different metallic coatings, the copper varnish is now replaced by a silver based ink, which provides high conductivity and is therefore commonly used in additive manufacturing. The network measurements are repeatedly carried out with a varying number of layers of lacquer applications on the body's surface. By deembedding a singular part from the measurements, it is shown that increasing surface conductivity leads to a significant impact on transmission parameters. In direct comparison, the silver coated CWT outperforms both preceding variants with copper varnish or aluminum clad. With more than 95 % transmitted power, it is indeed competitive compared to the industrially manufactured WR90 CWT reference. To conclude, the study focuses on a comparison of three different additive manufacturing processes for equal hollow waveguide geometries at moderate frequencies. It proves that CWT parts are producible in a simple and rapid process. The production stages with the strongest impact on performance are identified and demonstrated to be controllable. The variant presented finally is able to achieve competitive performance compared to commercial-grade parts, especially when considering the enormous cost reduction. In addition, it is proven that the RF parameter extraction method for symmetric two-port networks presented earlier by the authors is also applicable when the DUT exhibits high insertion losses. The central aim of this work is to demonstrate that additive manufacturing combined with low-cost metallization techniques can produce coaxial-waveguide transitions that approach the performance of industrial WR90 standards. This novelty highlights the feasibility of achieving near-commercial-grade quality at a fraction of the cost, thereby extending the accessibility of high-frequency components to research and prototyping applications.

Simulation of speckle interferometric results for enhanced measurement and automated defect detection

Jessica Plaßmann; Michael Schuth; Georg von Freymann — Thu, 22 Jan 2026 14:04:54 +0100

Techniques like speckle holography and shearography are rarely applied due to the complexity of instrument setup and lack of automated result analysis, despite their potential. By simulating speckle interferometric outcomes, we seek to address these challenges, enabling more efficient measurement processes and paving the way for automated defect recognition. This research focuses on developing a simulation code for speckle interferometric results derived from finite element analyses. The aim is to improve the parameter settings of speckle interferometry measurements and create specific datasets, which will be used to develop machine learning-based methods for automation in series production.

Modulation of cellular adhesion, contractility, and migration by MiuA: A comprehensive analysis of its biomechanical impact

Thu, 22 Jan 2026 13:44:30 +0100

Cellular adhesion and contractility are essential for cell movement. In this study, we investigated the effects of actin stabilization on adhesion properties, contractility, and cell migration. For this, we used the recently synthesized actin stabilizer miuraenamide A (MiuA), which has been discussed as a more reliable alternative to the otherwise commonly used actin stabilizer jasplakinolide. We investigated the number and size of focal adhesions in RPE-1 cells and used single-cell force spectroscopy to evaluate the adhesion properties of those cells after MiuA treatment. We showed that MiuA increases the number of focal adhesions while decreasing their size and reduces adhesion energy and force. Additionally, we investigated its effects on the contractility of RPE-1 cells by measuring their contractile energy using pattern-based contractility screening (PaCS). We found no significant change in contractility after MiuA treatment. Finally, we confined RPE-1 cells in PDMS microchannels and analyzed their migration after treatment with MiuA, showing that neither their speed nor their persistence is affected by MiuA. To check that these effects are not specific to RPE-1 cells, we also analyzed the effects of MiuA treatment in MEF cells and neutrophils. Both MEF cells and neutrophils showed the same results as the RPE-1 cells. Our measurements indicate that, although altering focal adhesions significantly reduces adhesion, it does not impact cell contractility. This finding also clarifies why amoeboid migration, which operates independently of adhesion, remains unaffected. Additionally, it explains the previously observed reduction in mesenchymal migration, which relies on adhesion-based mechanisms.

Effects of kilohertz versus low-frequency electrical stimulation of the wrist extensors in patients after stroke: A randomized crossover trial

Thu, 22 Jan 2026 12:29:51 +0100

Background: Electrical stimulation is an effective treatment method for improving motor function after stroke, but the optimal current type for patients with stroke and arm paresis remains unclear. Objective: To compare the effects of kilohertz frequency with low-frequency current on stimulation efficiency, electrically induced force, discomfort, and muscle fatigue in patients with stroke. Design: A randomized crossover study. Setting: Neurological inpatient rehabilitation clinic in Germany. Participants: A total of 23 patients with arm paresis after stroke within the last 6 months were recruited, 21 were enrolled, and 20 completed the study (7 females; mean ± SD: 66 ± 12 years; 176 ± 11 cm; 90 ± 19 kg; 57 ± 34 days since stroke). Intervention: All patients underwent both kilohertz and low-frequency stimulation in a randomized order on 2 days (48-hour washout). Each day included a step protocol with a gradual increase in stimulation intensity, starting at the first measurable force (up to 12 steps, 1 mA increments, 8 seconds stimulation, 60 second rest) and a fatigue protocol (30 repetitions, 8 second stimulation, 3 second rest). Main Outcome Measure: Primary outcome was stimulation efficiency (electrically induced force/stimulation intensity) [N/mA], measured during each step of the stepwise increase in current intensity protocol. Results: Linear-mixed-effects models showed significantly higher stimulation efficiency for low-frequency stimulation (mean difference 0.14 [95% confidence interval, 0.01–0.27 N/mA], p = .031). However, current type did not significantly affect electrically induced force, level of discomfort, or muscle fatigue (p > .05). Conclusion: The findings suggest that low-frequency stimulation is more efficient than kilohertz-frequency stimulation. However, both current types yield similar effects on force, discomfort, and fatigue, making them both viable options for wrist extensor stimulation in patients after stroke. Considering the variability among individuals, customizing the current type based on electrically induced force and perceived discomfort may enhance therapeutic outcomes. Further research on the long-term treatment effects of both current types is warranted.

A Two-Layer HiMPC Planning Framework for High-Renewable Grids: Zero-Exchange Test on Germany 2045

Alexander Blinn; Joshua Bunner; Fabian Kennel — Thu, 22 Jan 2026 11:48:30 +0100

High-renewables grids are planned in min but judged in milliseconds; credible studies must therefore resolve both horizons within a single model. Current adequacy tools bypass fast frequency dynamics, while detailed simulators lack multi-hour optimization, leaving investors without a unified basis for sizing storage, shifting demand, or upgrading transfers. We present a two-layer Hierarchical Model Predictive Control framework that links 15-min scheduling with 1-s corrective action and apply it to Germany’s four TSO zones under a stringent zero-exchange stress test derived from the NEP 2045 baseline. Batteries, vehicle-to-grid, pumped hydro and power-to-gas technologies are captured through aggregators; a decentralized optimizer pre-positions them, while a fast layer refines setpoints as forecasts drift; all are subject to inter-zonal transfer limits. Year-long simulations hold frequency within ±2 mHz for 99.9% of hours and below ±10 mHz during the worst multi-day renewable lull. Batteries absorb sub-second transients, electrolyzers smooth surpluses, and hydrogen turbines bridge week-long deficits — none of which violate transfer constraints. Because the algebraic core is modular, analysts can insert new asset classes or policy rules with minimal code change, enabling policy-relevant scenario studies from storage mandates to capacity-upgrade plans. The work elevates predictive control from plant-scale demonstrations to system-level planning practice. It unifies adequacy sizing and dynamic-performance evaluation in a single optimization loop, delivering an open, scalable blueprint for high-renewables assessments. The framework is readily portable to other interconnected grids, supporting analyses of storage obligations, hydrogen roll-outs and islanding strategies.

Impact of Autoclaving on the Material Properties of Vat-Photopolymerization-Produced Components Intended for Bioprocess Engineering

Thu, 22 Jan 2026 10:48:08 +0100

Due to a lack of investigated materials for the additive manufacturing of multi-use functional parts in bioprocess engineering, this study aimed to evaluate the influence of multiple autoclaving cycles on the properties of a heat-resistant material (xPeek147) printed with vat photopolymerization. Sample bodies were tested regarding their mechanical properties of tensile strength, elongation at break, and Charpy impact, as well as surface properties of roughness and wettability after up to 50 autoclaving cycles (121 °C, 2 bars, 15 min). The tightness was checked after up to 20 cycles, and accuracy was inspected for manufactured benchmark bodies after up to 10 autoclaving cycles. The reported results showed no significant changes in tensile strength, elongation at break and Charpy impact after 20 cycles, but a significant decrease after 50 autoclaving cycles, accompanied by microcracks in the structure. Regarding the surface properties the material retained its hydrophilicity, and the surface roughness was not affected significantly. No changes in tightness occurred, and the benchmark bodies for dimensional changes showed no process-relevant deviations. Through the investigations, a material for the additive manufacturing of multi-use functional parts for bioprocess engineering was identified. Additionally, a testing method for materials with the same intended application was provided.

Increased backpack weight might lead to increased trunk stiffness during walking in primary school aged children: A pilot study

Juliane Müller; Julia Simmer; Stefan Schmid; Christoph Zinnen; Steffen Müller — Thu, 22 Jan 2026 10:14:49 +0100

Background: Backpacks are essential in the daily lives of children. Carrying a heavy backpack affects trunk posture during standing. It remains unclear, whether this effect is also observed during gait. Research question: How do different backpack weights affect trunk kinematics during walking in children? Methods: Sixteen children stood and walked on a 5 m walkway with a custom load-carrying-system simulating unloaded and loaded backpacks (10 %;20 %;30 % of body mass (BM). A marker-based 3D motion analysis system captured whole-body kinematics (Rizzoli model). During walking, the primary outcomes were the maximum ranges of motion (RoM;[°]) of thoracic and lumbar trunk segmental angles in three planes. During standing, the average angles over 5 s were measured in three planes. Secondary measures included stride length, stride time, and velocity during walking. The children's own backpacks' weights were measured and expressed as a percentage of body mass. Statistical analysis was performed using repeated-measures ANOVA (α=0.05) and Tukey-Kramer post hoc test. Results: The average weight of the children’s own backpack was 15.4 ± 7.4 %BM. For the experimental conditions, the average weights added to the load-carrying system were 3.3 ± 0.8 kg (10 %BM), 6.5 ± 1.7 kg (20 %BM), and 9.8 ± 2.5 kg (30 %BM). During standing, the average trunk flexion angles (sagittal plane) of the lumbar trunk segment significantly increased with increased backpack weight (p = 0.002). During walking, no changes in sagittal plane RoM but significant decreases in lumbar and thoracic transversal and frontal plane RoM (p < 0.001), stride length (p = 0.047) and velocity (p = 0.041) were observed with additional weight. No significant differences were observed for stride time between the conditions. Significance: Added backpack weight led to a more flexed trunk posture during standing and reduced transversal and frontal plane trunk movement, stride length, and gait velocity during walking. These adjustments likely compensate for the dorsally displaced center of mass and minimize energy expenditure by reducing trunk-backpack-angular momentum during walking.

Characterizing surface roughness evolution in copper conductors under mechanical strain using power spectral density analysis

Christoph Maier; Paul Rachwalsky; Armin Wittmann; Klaus P. Koch; Georg Fischer — Wed, 21 Jan 2026 13:12:05 +0100

This study investigates the effects of mechanical strain on the surface roughness of copper conductors, focusing on the electrolyte-refined copper (Cu-ETP, CW004A) used in H07V-U 1.5 mm2 single-core cables. For the first time, the surface roughness evolution is characterized using the power spectral density (PSD) function, enabling a detailed roughness analysis across different spatial length scales. Conductors were subjected to mechanical stress, with measurements taken at multiple stages of service life. The study confirms the results from other studies that surface roughness increases significantly in the early stages of loading, with a plateau observed in 50 % - 75 % of cycles to failure. Micro crack formation and material extrusion are identified as key mechanisms driving roughness growth, especially at small length scales, with a shift towards larger length scales as strain intensifies. The increasing Hurst exponent suggests a transformation from a random to a more persistent and correlated surface. The results underscore the potential of power spectral density analysis in understanding surface behavior in copper conductors.

Automated photo content classification of Instagram posts to identify patterns of human uses in peri-urban protected areas: A case study from Vienna, Austria

Tue, 20 Jan 2026 13:48:02 +0100

Blue and green spaces in cities provide essential ecosystem services to their inhabitants, including recreational and experiential opportunities. Their importance became further highlighted during the COVID-19 pandemic as urbanites sought to relieve some of the associated pressure. However, urban ecosystems are threatened by degradation and pollution, but also by other activities, including recreation. In this context, protected areas face the challenge of balancing visitor interests with conservation objectives, particularly in peri-urban areas. Social media provides an opportunity to analyse human activities in such areas. This study investigates spatial and temporal patterns in Instagram photos at three case study sites in Vienna, Lainzer Tiergarten, Lobau, and Nussberg with different protection statuses between 2018 and 2022. Automated content labeling using Google's Cloud Vision API and subsequent classification identified 19 clusters from 54,751 downloaded photos. Seasonal variations were observed, such as the prevalence of Plant and Insect photos in spring and summer, and Landscape content in autumn and winter. The COVID-19 pandemic coincided with and contributed to an increase in user activity, but seasonal trends were unaffected. Site-specific patterns also emerged, with Panoramas dominating in Nussberg, the Riverscape characterizing Lobau, and Woodlands dominating in Lainzer Tiergarten. Our findings demonstrate that automated social media photo content analysis can capture spatial and temporal variations in visitor behavior and landscape preferences, providing valuable insights for targeted visitor management and the establishment of conservation strategies in peri-urban ecosystems. Integrating these analyses with other methods, such as surveys or mobile phone tracking, can provide a more comprehensive understanding of human-environment interactions.

Applying the Cultural Values Model to assess biocultural change in Eastern European wood-pastures

Tue, 20 Jan 2026 13:10:24 +0100

1. Traditional wood-pastures are emblematic of multifunctional farming systems. Despite their exceptional ecological and cultural value, these systems are undergoing rapid transformation under the combined pressures of modernization, land-use intensification and shifting societal values. 2. We apply the Stephenson's Cultural Values Model to assess the biocultural complexity of 110 ancient wood-pastures across Transylvania, Romania, a unique region of Eastern Europe, where traditional land-use systems persist amidst accelerating institutional and economic change. The three dimensions of the Cultural Values Model—‘Forms’ (material structures), ‘Practices’ (land-use activities) and ‘Relationships’ (cultural meanings and memories)—were quantified through field surveys and 32 semi-structured interviews with local stakeholders. 3. Our results reveal diverse biocultural profiles, with traditional and modern elements (i.e. ‘Forms’ and ‘Practices’) frequently co-occurring. While many sites retain legacy features such as scattered veteran trees and extensive grazing, signs of social-ecological reconfiguration are evident, including electric fencing, mechanized infrastructure, and declining communal governance. Landscape-level analyses show that traditional features (‘Forms’, ‘Practices’ in the Cultural Values Model framework) persist more often in rugged terrains, whereas modernization predominates in flatter, more accessible areas. Interview data show an erosion of cultural engagement, stewardship norms and local agency. 4. Our findings suggest that the transformation of ancient wood-pastures can be effectively traced through the three pillars of the Cultural Values Model: ‘Forms’, ‘Practices’ and ‘Relationships’. The framework proved especially valuable in disentangling how material, functional and symbolic dimensions of these landscapes evolve in response to socio-economic and institutional pressures. We also showed that the Cultural Values Model can be a practical tool for assessing biocultural complexity and identifying early signs of system reconfiguration of traditional farming systems.

Arithmetic fact retrieval deficits in chronic stroke – A deficit of relearning?

Stefan Smaczny; Stefanie Jung; Klaus Willmes; Hans-Otto Karnath; Elise Klein — Tue, 20 Jan 2026 12:36:03 +0100

In acute stroke patients, arithmetic fact retrieval deficits have been observed due to disrupted white matter connections within a left-hemispheric network centered around the angular gyrus and middle temporal gyrus (Smaczny et al., 2023). However, it remains unclear which specific structural disconnections also hinder successful remediation in the chronic stage of stroke. In this study, 92 patients were examined to determine which impairments continue to affect multiplication performance even in the chronic phase after a first-time unilateral left-hemispheric stroke. Our results revealed a strong association between impaired multiplication performance and the disconnection of left long-term memory (para)hippocampal areas from left frontal and right parietal regions. Thus, unlike previous findings in the acute stroke phase, our results in the chronic phase emphasize the importance of (para)hippocampal regions for successful multiplication performance. We suggest that the affected areas and connections in chronic patients with persistent multiplication problems not only indicate areas that are crucial for the relearning of arithmetic facts, but also those crucial for the learning of arithmetic facts in general. More generally, we suggest that the acquisition of arithmetic facts depends on structural integrity of a network centered around the left (para)hippocampus, while the retrieval of consolidated arithmetic facts from memory relies on the integrity of a left-hemispheric network involving angular gyrus and middle temporal gyrus.

Analysis of Microphony at Electrodes under Dynamic Flow by Mechanical Excitation

Marie-Claire Weisgerber; Ngoc Minh Huy Thai; Frank Kirchhoff; Klaus P. Koch — Tue, 20 Jan 2026 11:55:10 +0100

Relative movements between electrodes and tissue are a potential source of interference signals that can affect the accuracy of signal recordings and data analyses. To address this challenge, a test bench is developed that utilises mechanical excitation to impose dynamic flow on the electrodes under various conditions to characterize the influence on signal quality. The generated data can then be recorded and analysed with the Fast Fourier Transformation.

Staphylococcus aureus Adhesion on Hydrophobin Coatings: Adhesion Forces and the Influence of Surface Charge

Tue, 20 Jan 2026 10:53:46 +0100

Staphylococcus aureus (S. aureus) is one of the bacterial species capable of forming multilayered biofilms on implants. Such biofilms formed on implanted medical devices often require the removal of the implant in order to avoid sepsis or, in the worst case, even the death of the patient. To address the problem of unwanted S. aureus biofilm formation, its first step, i.e., adhesion, must be understood and prevented. Thus, the development of adhesion-reducing surface coatings for implant materials is of utmost importance. In this work, we used single-cell force spectroscopy to analyze the adhesion of the biofilm-forming S. aureus strain SA113 on naive and protein-coated silicon surfaces (SiO2). In addition to the wild type, we used the SA113 ΔdltA knockout mutant to further investigate the effect of d-alanylation of lipoteichoic acids of the cell wall. In order to examine how the surface charge affects adhesion, we coated silanized SiO2 surfaces with amphiphilic class II hydrophobins. The naturally occurring hydrophobin HFBI was used as well as the HFBI variant D40Q/D43N, which is less negatively charged at physiological pH due to the exchange of two acidic aspartate residues. These two types of hydrophobin-coated surfaces resemble each other in roughness and wettability but differ only in charge. By measurement of the forces with which each S. aureus strain binds to hydrophobin-coated surfaces, we show that the adhesion of S. aureus at surfaces can be influenced by the charges exposed by the target surfaces. Therefore, in addition to hydrogen bonding, electrostatic interactions between the cell and the hydrophilic surface govern adhesion on these surfaces. Moreover, we found that for both HFBI coatings, the adhesion strength of S. aureus is reduced by nearly a factor of 30 compared to silanized SiO2 surfaces. Therefore, hydrophobin coatings are of great interest for further use in the field of biomedical surface coating.

Human contributions to global soundscapes are less predictable than the acoustic rhythms of wildlife

Mon, 19 Jan 2026 14:55:36 +0100

Across the world, human (anthropophonic) sounds add to sounds of biological (biophonic) and geophysical (geophonic) origin, with human contributions including both speech and technophony (sounds of technological devices). To characterize society’s contribution to the global soundscapes, we used passive acoustic recorders at 139 sites across 6 continents, sampling both urban green spaces and nearby pristine sites continuously for 3 years in a paired design. Recordings were characterized by bird species richness and by 14 complementary acoustic indices. By relating each index to seasonal, diurnal, climatic and anthropogenic factors, we show here that latitude, time of day and day of year each predict a substantial proportion of variation in key metrics of biophony — whereas anthropophony (speech and traffic) show less predictable patterns. Compared to pristine sites, the soundscape of urban green spaces is more dominated by technophony and less diverse in terms of acoustic energy across frequencies and time steps, with less instances of quiet. We conclude that the global soundscape is formed from a highly predictable rhythm in biophony, with added noise from geophony and anthropophony. At urban sites, animals experience an increasingly noisy background of sound, which poses challenges to efficient communication.

An active ensemble classifier for detecting animal sequences from global camera trap data

Thu, 15 Jan 2026 13:12:30 +0100

1. Camera traps can generate huge amounts of images, and thus reliable methods for their automated processing are in high demand: in particular to find those images or image sequences that actually include animals. Automatically filtering out images that are empty or contain humans can be challenging, as images can be taken in different landscapes, habitats and light. Weather and seasonal conditions can vary greatly. Most of the images can be empty, because cameras using passive infrared sensors (PIR) trigger easily due to moving vegetation or rapidly varying shadows and sunny spots. Animals in images are often hiding behind vegetation, and camera traps will see them from previously unseen angles. Therefore, conventional animal image detection methods based on deep learning need huge training sets to achieve good accuracy. 2. We present a novel background removal approach based on movement masked images computed using sequences of images. Our deep vision classifier uses these movement images for classification instead of the original images. Additionally, we apply a deep active learning (active learning for deep models) for collecting training samples to reduce the number of annotations required from the user. 3. Our method performed well in singling out image sequences that actually include animals, thus filtering out the majority of images that were empty or contained humans. Most importantly, the method performed well also for backgrounds and animal species not seen in the training data. Active learning brought good separation between classes already with small training sets, without the need for laborious large-scale pre-annotation. 4. We present a reliable and efficient method for filtering out empty image sequences and sequences containing humans. This greatly facilitates camera trapping research by enabling researchers to restrict the task of animal classification to only those image sequences that actually contain animals.

Perceptions and beliefs of physical therapists regarding the mechanisms of manual therapy

Thu, 15 Jan 2026 12:40:10 +0100

Background: Manual therapy (MT) is a widely utilized approach for managing musculoskeletal pain and functional disorders, particularly through joint mobilizations. Traditionally explained by immediate biomechanical processes, a paradigm shift has occurred in the last few decades, recognizing neurophysiological mechanisms as crucial contributors. Objectives: To evaluate whether this shift is also reflected by clinicians, this study explores the beliefs and perceptions of physical therapists regarding the mechanisms underlying MT through an online survey design. The focus was if dominantly peripheral biomechanical model or a neurophysiological explanatory model prevails. Methods: The study involved a national cross-sectional survey of 569 physical therapists, average age 36.5y (9.7), and 58 % female. Based on a fictitious case scenario, participants rated on a scale from 0 % to 100 %, the involvement of anatomical structures and physiological mechanisms and provided additional suggestions. Results: The majority of responders attributed significant involvement to the brain (75 %), myofascial structures (71 %), peripheral nervous system (68 %), and cervical joints (60 %). Mechanisms such as endogenous pain modulation (73 %), placebo effects (72 %), muscle activity (68 %), and neuromuscular responses (62 %) were commonly endorsed. The data indicated that socio-demographic and work-related characteristics are weakly associated to specific beliefs, emphasizing the complex nature of these perspectives. The findings underscore the diversity in physical therapists' beliefs and highlight the importance of understanding the mechanisms, as they significantly contribute to the perceived effectiveness of MT. Conclusion: This study provides valuable insights into the current landscape of beliefs among German physical therapists, contributing to the ongoing dialogue between basic research and clinical practice in MT.

New Methods in Food Processing and Analysis

Marc Regier — Tue, 13 Jan 2026 12:59:36 +0100

The food industry is currently undergoing a profound transformation. Growing demands for sustainable production; heightened expectations of safety, quality, and quantity; and the urgent need for greater efficiency call for innovative solutions (see, for example, and the references therein). The transformation of the food system is supported and simultaneously demanded by the UN Sustainable Development Goals and related initiatives such as the Global Panel. An important task in this regard is assigned to production, processing and analysis. This Special Issue on New Methods in Food Processing and Analysis brings together research that highlights how new technologies can help shape the future of food, addressing some of these demands. The articles in this collection present advances that, in part, go beyond incremental improvements. They showcase novel processing technologies, ranging from ultrasound to pulsed electric fields as pretreatment for innovative extraction processes and drying to ethanol pickling. At the same time, state-of-the-art analytical tools, such as laser-induced breakdown and fluorescence spectroscopy (combined with machine learning) for olive oil authentication and real-time-monitoring of dough mixing, open new avenues for controlling and optimizing food production. What unites these diverse approaches is their relevance to current challenges being faced. Ensuring sustainability, maintaining authenticity, and safeguarding traceability in complex supply chains are not merely technical issues—they are a concern of public trust and global food security. The contributions to this Special Issue therefore not only expand the scientific frontier but also provide practical strategies for industry and policy.

Mechanoelectrical Effects in Natural Fiber-Reinforced Polymers as Structural Health Monitoring

Christoph Maier; Philipp Huber; Armin Wittmann; Klaus P. Koch; Georg Fischer — Tue, 13 Jan 2026 12:34:35 +0100

Natural fiber-reinforced polymers are gaining popularity as sustainable structural materials. However, their inherent variability can limit their reliability in load-bearing applications. To address this issue, we investigate a novel structural health monitoring method that leverages mechanoelectrical effects in flax fiber-reinforced epoxy composites. In our study, a contactless capacitive coupled measurement setup records electrical polarization during fatigue testing at four load levels. The polarization signals we observed increased with increasing load levels. Additionally, changes in polarization correlate with changes in dynamic modulus, providing early indicators of potential failure. This work lays the foundation for a new type of structural health monitoring in natural fiber-reinforced polymers.

Determining the natal origin of the reintroduced allis shad (Alosa alosa) in the Rhine River using otolith microchemistry

Tue, 13 Jan 2026 11:58:18 +0100

Locally extinct since the 1960s, the anadromous allis shad (Alosa alosa) was reintroduced into the Rhine system through a restocking programme beginning in 2007. The population is now showing positive signs of recovery, with natural reproduction occurring for several years and a decreasing proportion of stocked fish. These findings suggest the future establishment of a self-sustaining population. Our study aimed to identify the spawning sites in the Rhine system. We conducted a tank experiment and kept shad larvae in water from four sub-catchments of the Rhine system. We analysed trace substance concentrations in water samples and the microchemical composition of otoliths from reared larvae. Using a random forest model, we were able to correctly attribute the larvae to the sub-catchment where they were raised based on elemental/ratio (Sr/Ca) and strontium isotopes (87Sr/86Sr). From the 66 allis shad caught in the Rhine system between 2017 and 2020, seven individuals (11%) were identified as being stocked. Of the 59 remaining individuals that came from natural reproduction, 37 were attributed to the Rhine, 7 to the Neckar and 4 to the Lippe sub-catchments with high certainty. We also observed allis shads dispersed in adjacent catchment areas and a homing behaviour. A total of 27% of the adults (n = 9) and 8% of the juveniles (n = 2) were assigned to any of the four sub-catchments included in our model, suggesting the need to expand the model and include additional sub-catchments to cover all spawning sites in the Rhine system and adjacent catchments.

Traditional bone setting in Nigeria from the perspectives of patients and physiotherapists — clinical insights for low back pain management

Mishael Adje; Sven Karstens; Chidozie Mbada; Jost Steinhäuser — Mon, 12 Jan 2026 15:59:05 +0100

Background: Traditional bone setting (TBS) remains a prevalent healthcare practice in Nigeria, offering complementary treatments for musculoskeletal conditions such as low back pain (LBP). This study explores the perspectives of both patients and physiotherapists regarding TBS and its implications for the management of LBP. Methods: A qualitative research approach was employed, utilizing semi-structured interviews with 25 participants (13 patients who had utilized TBS services for LBP, and 12 physiotherapists). Theoretical sampling was employed in participant recruitment until saturation. Recordings were transcribed and thematic analysis was conducted as a secondary analysis. Reporting was informed by the Consolidated Criteria for Reporting Qualitative Research (COREQ). Results: Eleven (11) participants were female and 14 were male; with a mean age of 35 years. Five themes were identified from this study: driving impetus for TBS, influencing perceptions with information, turning to TBS as a final recourse, exploring the primary alternative, and integrating TBS. The shift towards TBS for LBP stems from deficiencies in prevailing healthcare practices in Nigeria. Patients and physiotherapists hold varying perspectives regarding cultural significance, and effectiveness and safety of TBS compared to professional physiotherapy interventions. Accessibility, affordability, and perceived efficacy are common facilitators for the patronage of TBS among patients, while others were hesitant and viewed it as a last resort. Negative perception of physiotherapists about TBS for LBP were based on concerns regarding the lack of scientific evidence, standardized practices, and potential complications associated with the procedures. Conclusion: Participants consider TBS viable when professional physiotherapy fails, citing expectations for therapist-guided techniques, affordability, and cultural factors. Physiotherapists remain cautious, stressing the need for evidence-based care and noting severe TBS complications. Some participants advocate for integrating TBS with professional healthcare through collaboration and better communication. This study, supported by literature, highlights the potential for TBS integration, with open communication and training fostering collaboration. Future studies could investigate the practicality of this integration, prioritizing culturally appropriate, safe, and effective approaches to LBP management.

Feasibility and user experience of augmented reality psychoeducation and mindfulness body scan for chronic low back pain

Robin Conen; Nikolai Hepke; Jörg Lohscheller; Steffen Müller; Ana N. Tibubos — Mon, 12 Jan 2026 14:50:44 +0100

Background: Chronic low back pain (CLBP) is prevalent and a multimodal therapy is indicated, including psychological treatment. Effective conventional treatments involve psychoeducation and mindfulness-based body scans, while virtual reality offers superior but temporary pain relief. Augmented Reality (AR), which combines conventional and virtual methods, is a novel therapeutic strategy. Methods: We investigated the viability and acceptability of an AR intervention for CLBP by incorporating psychoeducation and mindfulness-based body scan techniques. 40 participants in two studies with a one-arm design underwent an educational AR intervention (Study I, n1 = 18) and an enhanced version with an additional body scan (Study II, n2 = 22). The studies focused on evaluating technical feasibility and multiple facets of user experience. Results: The results demonstrated high feasibility with low dropout rates (Study I: 10%, Study II: 0%). User experience ratings ranged from “Above Average” to “Excellent,” with the advanced intervention receiving higher ratings. While Study I showed no significant changes in affect pre- vs. post-intervention, Study II exhibited a significant reduction in negative affect and improved valence. Qualitative analysis provided insights into technical requirements and user perceptions. Discussion: The AR prototype emerges as a promising psychoeducational tool for CLBP, aligning with current treatment guidelines and providing a basis for future controlled clinical trials. Limitations include the absence of a high-pain intervention group, as Study I reported a pain intensity of M = 1.05 and Study II reported M = 1.77 (Range: 0–10). Further research such as clinical trials with control groups is required to validate the efficacy of the piloted approach. The AR-based psychoeducation and mindfulness body scan intervention for CLBP demonstrated technical feasibility and a good user experience.

Overlooked – Presence and awareness cues in the metaverse

Rene Arnold; Anna Schneider — Mon, 12 Jan 2026 14:19:34 +0100

This article examines how “Presence and Awareness Cues” (PAACs) such as read receipts, online status indicators, and typing notifications shape data disclosure in computer-mediated communication (CMC), with particular focus on emerging metaverse contexts. PAACs are often overlooked in current policy debates despite their potential to reveal sensitive behavioral, relational, and even physiological information. Drawing on a broad review of related literature, we propose a conceptual framework outlining four pillars of mediated presence (PAACs, content, aesthetics, and fidelity), offering policymakers a technology-agnostic lens for anticipating developments in augmented and virtual settings. We then present findings from a six-country survey (n = 18,358) examining whether and how users notice, interpret, and control PAACs, as well as their willingness to share additional cues in advanced AR/VR environments. Results indicate that most users recognize PAACs across diverse online services and adapt their behavior accordingly. These insights underscore potential policy gaps when biosignals such as heart rate and gaze become integral to projected availability or emotional states. We conclude that balancing consumer protection with user-friendly interfaces calls for more nuanced oversight, especially as the European AI Act and related legislation could inadvertently limit the adoption of intuitive PAACs. Future research should probe how users negotiate these cues in fully interoperable metaverse environments, particularly when multiple identities or cross-application interactions come into play.

Analysis of water-in-gasoline emulsions via experiments and direct numerical simulations

Benjamin Blau; Oscar Krzeczek; Christoph Heinrich; Markus Klein — Mon, 12 Jan 2026 13:50:44 +0100

This work explores the combination of direct numerical simulations (DNSs) and experimental approaches for studying technical emulsification processes. Although emulsions have long been used in a variety of industries and many important research papers have been published over the years, quantifying and predicting the dispersion of droplets in another liquid remains challenging because of the complex multiphase nature and microscopic droplet scales. This study focuses on water-in-gasoline emulsions, which have the potential to improve efficiency and reduce emissions in combustion-based power generation. Experimental data from two different emulsion injection systems are complemented with DNS to gain insight into emulsification and the resulting droplet size distribution. In situ shadow imaging is used to acquire the experimental droplet size distributions, whereas DNS is performed via the geometric volume of fluid (VoF) method with the open-source code PARIS. The results indicate consistent agreement between the experimental and simulation results. Additionally, a corresponding trend of increasing droplet size is observed as the volume fraction of the dispersed phase increases. Furthermore, a detailed analysis of various probability density functions for modeling droplet size distributions (DSDs) reveals that the gamma distribution is the most appropriate. Overall, this work demonstrates that DNS can be successfully combined with experiments to increase the understanding of emulsification processes.

Catch effectiveness, complementarity and costs of five sampling techniques for flying insects across different land use types

Lara Hoffmann; Stefan Stoll — Mon, 12 Jan 2026 13:17:06 +0100

1. In times of insect decline, sampling programmes are fundamental for monitoring and protecting insect populations. Different types of traps are currently used for insect monitoring, which makes trap selection more challenging and impedes the comparability of results among methods. 2. Trap comparisons, which reveal the species richness, complementarity and costs for the materials and operation of different trap types, help identify sampling designs that ensure (cost-)efficient insect capture. 3. For our study, we selected five sampling techniques for flying insects: canopy Malaise traps (CAMTs), caterpillar traps, branch sampling and white and blue pan traps. We compared them across four habitats (forest, margin and centre of short rotation coppices and maize fields) using detected Barcode Index Numbers (BINs). Comparisons were performed for the total arthropod community and separately for the Coleoptera, Diptera, Lepidoptera and Hymenoptera orders. 4. Our trap selection demonstrated high complementarities of 66–77% depending on the habitat. Our findings indicate that, in most cases, CAMTs, branch sampling and caterpillar traps were the most effective and cost-efficient options when used individually or in combination. Caterpillar traps were particularly effective in forests and detected far more taxa than only lepidopterans. Pan traps demonstrated the lowest species richness and poorest cost efficiency. Nevertheless, it is important to consider individual groups and habitats, such as Diptera, Coleoptera and maize fields, for which pan traps can also be an effective method.

Spinning ethical plates in times of pandemic and sustainability [new layout]

Milena Valeva; Lurie Yotam — Thu, 09 Oct 2025 15:04:16 +0200

This article discusses ethics in times of pandemic crisis (COVID-19) taking into consideration the sustainability paradigm. Two related ethical approaches are discussed and contrasted. On the one hand, the relational embodied ethics of the commons is discussed in the background of the pandemic of COVID-19. On the other hand, "lifeboat ethics" is interpreted in considering the pandemic situation. The main goal of the article is to compare the two ethical approaches as a way of dealing with our shared predicament in times of a pandemic, a state of exception, and based on that, to additionally derive conclusions about their application in further crises in the Anthropocene, whereby the primacy of sustainability is presumed.