https://opus4.kobv.de/opus4-uni-koblenz

Effects of Perfluorotetradecanoic Acid (PFTeDA) and Biostimulants on Soil Bacterial Community Structure and Diversity and the Growth of Amaranthus cruentus

Wed, 12 Aug 2026 08:21:11 +0200

Perfluorotetradecanoic acid (PFTeDA), a long-chain per- and polyfluoroalkyl substance (PFAS), is highly persistent and bioaccumulative, yet its effects on soil bacterial communities remain poorly understood. This study evaluated the impact of PFTeDA on the taxonomic composition, diversity, and functional potential of soil bacteria, and assessed whether biostimulants (Shigeki and Aminoprim) could mitigate these effects and improve the growth of Amaranthus cruentus. A pot experiment was conducted using Eutric Cambisols soil (pH 4.62), and bacterial communities were analyzed by 16S rRNA gene sequencing. PFTeDA significantly altered bacterial community composition, reducing the abundance of Actinomycetota, Chloroflexota, and Gemmatimonadota, while also changing alpha and beta diversity and predicted functional profiles. Biostimulant application partially alleviated these effects by promoting recovery of the soil bacterial communities and bacteria associated with nitrogen cycling and organic matter degradation, indicating partial restoration of soil ecosystem functions. PFTeDA reduced aboveground biomass but increased root biomass of A. cruentus , without affecting leaf greenness (SPAD). Both biostimulants enhanced plant growth and SPAD values, with Aminoprim exerting a stronger effect on shoot biomass and Shigeki stimulating root development. This study demonstrates that PFTeDA affects not only the taxonomic composition of the soil bacterial communities but, above all, its stability and predicted functional potential, representing a key mechanism underlying its impact on the soil–plant system. It also highlights that biostimulation may serve as an effective tool supporting the potential improvement in soils contaminated with persistent organic compounds.

Shifting from cubical to equitable spatial task designs reduces gender differences in children’s mental rotation performance

Michelle Lennon-Maslin; Vera Ruthsatz; Claudia Quaiser-Pohl — Mon, 10 Aug 2026 10:51:10 +0200

Spatial ability, particularly mental rotation, has been widely studied in relation to gender differences. Ensuring equitable assessment of spatial skills is especially relevant for sustainability-related STEM (Science, Technology, Engineering and Mathematics) domains, where early educational experiences may shape later participation patterns. This study examined gender differences using a newly developed computerised Mental Rotation Test (nMRT) measuring accuracy and response time across 28 items varying in stimulus type and difficulty. To enhance inclusivity in task design, the test included concrete objects (e.g., cars, dolls, animals) and abstract figures (cubes, pellets, polyhedra), comprising male-stereotyped, female-stereotyped, and neutral objects. Stimuli were presented in two test parts, with rotations in picture plane followed by rotations in depth. Participants were 279 German primary school children ( Mage = 8.66 years; 134 girls, 145 boys), tested in classroom settings. Reliability analyses indicated high overall internal consistency of the nMRT ( α = 0.86). Multivariate analyses revealed no overall gender differences in accuracy or response time ( ps > 0.05), indicating broadly comparable performance across the full test. A small but reliable accuracy advantage for girls emerged only for picture-plane rotations of animals and letters ( ηp 2 = 0.03). Although boys demonstrated a small advantage for female-stereotyped stimuli rotated in depth, this effect did not remain statistically significant following correction for multiple comparisons. Controlling for age did not substantially alter the overall pattern of findings. Improved performance on some abstract stimuli across test parts was consistent with the effects of task familiarity. Overall, the findings suggest that gender differences in childhood mental rotation performance are sensitive to contextual and task-related factors, including stimulus content and rotation format, rather than emerging uniformly across spatial tasks.

Mitteilungsblatt der Universität Koblenz, Nr. 4/2026

Mon, 10 Aug 2026 09:44:55 +0200

Erste Ordnung zur Änderung der Antidiskriminierungsrichtlinie der Universität Koblen7

Toxicological effects of a difenoconazole fungicide on a non-target butterfly

Klaus Fischer; Jawaria Khalid; Mine Yilmazer; Ange Raharivololoniaina — Mon, 10 Aug 2026 09:15:07 +0200

Agricultural intensification, driven by increasing food demand, is one of the main drivers of global biodiversity loss. Pesticides, including fungicides, may increase crop yield but pose substantial threats to the environment. However, our current knowledge on the effects of fungicides on biodiversity suffers from less research interest compared to other pesticides and a neglect of insect herbivores. We here investigate the effects of a commercially available, ready-to-use difenoconazole fungicide on a non-target insect, the butterfly Pieris napi , under controlled laboratory conditions. When being fed with fungicide-treated host plants, butterfly larvae showed a strongly reduced survival (15%) compared to controls (60%). Survival in larvae treated with the fungicide plus an insecticide was only 1%. Sublethal effects of the fungicide included prolonged development and reduced adult size. Our results indicate a surprisingly high toxicity of the tested fungicide formulation on P. napi . Based on the available literature, we speculate that triazole fungicides may be in general toxic to Lepidoptera and potentially other herbivorous insects. This study contributes to the growing evidence that fungicides may well be involved in the loss of insect biodiversity in agricultural landscapes at the global scale.

Die Inszenierung von Empörung. Eine Untersuchung der Körpersprache bei Politikerinnen und Politikern

Christine Campen — Wed, 29 Jul 2026 13:10:03 +0200

Die vorliegende Dissertation untersucht die mimische Inszenierung von Empörung bei Politikerinnen und Politikern. Ausgangspunkt ist die Beobachtung, dass Empörung in politischen Auseinandersetzungen eine zentrale Rolle spielt, ihre mimische Ausdrucksform jedoch bislang nur unzureichend empirisch erschlossen ist. Während die sozialwissenschaftliche Forschung Empörung größtenteils als sprachlich artikulierte moralische Bewertung oder als individuelle emotionale Reaktion behandelt, bleibt ihre mimische Darstellung in konkreten Interaktionssituationen weitgehend unbeachtet. Vor diesem Hintergrund zielt die Arbeit darauf, Empörung als beobachtbare und intersubjektiv verstehbare Ausdruckshandlung zu rekonstruieren. Die leitende Forschungsfrage lautet: Wie wird Empörung von politischen Akteurinnen und Akteuren mimisch inszeniert? Empörung wird als moralische Emotion gefasst, deren soziologische Relevanz nicht in einem inneren Zustand, sondern in ihrer öffentlichen Inszenierung liegt. Sie wird als soziale Handlung begriffen, die in mimischen Ausdrucksformen hervorgebracht wird und a intersubjektiv verstehbar ist. In dieser Perspektive fungiert Empörung als Form öffentlicher Bewertung, durch die normative Grenzen markiert und politische Positionierungen vorgenommen werden. Die empirische Untersuchung basiert auf der Analyse audiovisuellen Aufnahmen parlamentarischer Debatten des Deutschen Bundestages sowie eines politischen Statements. Zur systematischen Erfassung mimischer Ausdrucksbewegungen wird das Facial Action Coding System (FACS) in einen soziologischen Untersuchungsrahmen integriert und methodisch angepasst, um mimische Ausdrucksformen in ihrer konkreten Struktur empirisch rekonstruieren zu können und soziologisch nutzbar zu machen. Die Ergebnisse zeigen, dass die mimische Inszenierung von Empörung durch einen stabilen Ausdruckskern gekennzeichnet ist, der ihre intersubjektive Verstehbarkeit gewährleistet. Dieser wird situativ durch weitere emotionale und gestische Elemente variiert und eingebettet in szenische Interaktionsverläufe. Zugleich ist Empörung maßgeblich durch Debattenlogiken und Darstellungsbedingungen strukturiert. Empörung ist demnach eine kontextgebundene und strategisch einsetzbare Ausdruckshandlung Die Arbeit trägt zur soziologischen Emotionsforschung bei, indem sie Empörung als mimisch sichtbare Inszenierungsform politischer Kommunikation rekonstruiert und mit der Integration des FACS einen methodischen Zugang zur Analyse mimischer Ausdrucksformen etabliert.

Happiness Meanders: A cross-cultural dataset on happiness, emotions, and models of selfhood from 48 countries

Wed, 29 Jul 2026 07:52:33 +0200

This data paper presents a dataset, of 12,361 observations compiled from the Happiness Meanders project, which explores cultural variations in individual and family well-being, ideal and actual happiness, emotional experiences and expressions, and cultural models of selfhood across 48 countries. Participants were recruited through academic networks. Data were collected using standardised scales, including the Satisfaction with Life Scale, the Interdependent Happiness Scale, the Cultural Models of Selfhood Scale, and the Emotional Experience and Expression inspired by Affect Valuation Index. The dataset underwent thorough technical validation, including checks for variable consistency, handling missing data, and identifying potential response biases. A filter for data quality was applied, with potentially unreliable data flagged for exclusion. This dataset offers a valuable resource for examining cultural influences on emotional dynamics (frequence of experience and expression), individual and family oriented evaluations of happiness, ideal and actual evaluation of happiness, cultural models of selfhood, and can support further research in cross-cultural psychology and related social sciences.

Distribution and Relative Abundance of Bean Leaf Beetles (Ootheca spp.) (Insecta: Coleoptera: Chrysomelidae) in Uganda

Fri, 24 Jul 2026 07:50:57 +0200

Bean leaf beetles (Ootheca spp.) (Insecta: Coleoptera: Chrysomelidae) are one of Africa’s most destructive pests of common bean and other leguminous crops. The beetles are widely distributed in Africa where they are estimated to cause annual crop yield losses of 116,400 tons of crop yields in sub-Saharan Africa. Despite their importance, little is known about the distribution, relative abundance and damage caused by bean leaf beetles in Uganda. As a result, the development of effective management methods has been hampered. We conducted surveys in six key Ugandan agro-ecological zones to determine the species distribution and relative abundance of bean leaf beetles. Findings indicate that leaf beetles belonging to 12 genera are present, including members of the genera Afrophthalma Medvedev, 1980, Buphonella Jacoby, 1903, Chrysochrus Chevrolat in Dejean, 1836, Diacantha Dejean, 1845, Exosoma Jacoby, 1903, Lamprocopa Hincks, 1949, Lema Fabricius, 1798, Nisotra Baly, 1864, Neobarombiella Bolz and Wagner, 2012, Ootheca Dejean, 1935, Parasbecesta Laboissière, 1940, and Plagiodera Dejean, 1835. We identified only three species belonging to the genus Ootheca: O. mutabilis, O. proteus, and O. orientalis. Seventy percent of all the beetles collected were O. mutabilis and these were present in all agro-ecological zones studied. The Northern Moist Farmlands (21.9%), West Nile Farmlands (12.9%), Central Wooded Savanna (4.4%) and Southern and Eastern Lake Kyoga Basin (1.4%) were the only agro-ecological zones where O. proteus was found. Only one specimen of O. orientalis was found at a single site in the Central Wooded Savanna. The Northern Moist Farmlands had a significantly (p < 0.05) higher bean leaf beetle density than the West Nile Farmlands and Southwestern Highlands. Similarly, the Northern Moist Farmlands had the highest beetle foliar damage per plant (1.15 ± 0.05), while the Southwestern Highlands had the lowest (0.03 ± 0.02). We provide the first information on Ootheca species distribution, abundance and damage in Uganda. Our findings provide a foundation for assessing the importance of Ootheca spp. as common bean pests in Uganda.

Maßnahmenvorschläge zur Erhöhung der Biodiversität von Arthropoden in Erwerbsobstanlagen

Doris Dannenmann; Elke Hietel; Thomas Wagner — Thu, 23 Jul 2026 08:57:29 +0200

Gerade Dauerkulturen, welche über viele Jahre bestehen bleiben, können einen großen ökologischen Wert für Insekten und Spinnentiere darstellen, wenn die negativen Einflüsse durch die Bewirtschaftung durch gezielte Maßnahmen minimiert werden. Im Rahmen eines Forschungsprojektes wurde von 2016 bis 2019 an der TH Bingen in Zusammenarbeit mit der Gemeinde Zornheim (Rheinhessen), zwei dort ansässigen Obstbauern, dem Dienstleistungszentrum Ländlicher Raum Rheinhessen-Nahe-Hunsrück (DLR RNH) und der Universität Koblenz-Landau (Campus Koblenz), gefördert durch die Stiftung Natur- und Umwelt Rheinland-Pfalz die Biodiversität von Obstanlagen untersucht. Es wurde eine intensive Erfassung der Insekten und Spinnentiere auf Basis von Individuenzahlen, Verteilung der Tiere auf Großgruppen, Artenzahlen der Käfer (inkl. Rote Liste) und Wanzen, deren Diversität und der sie beeinflussenden Faktoren auf vier Erwerbsobstflächen und einer Streuobstwiese als Referenzfläche untersucht. Mittels eines im Projekt erarbeiteten Bewertungsbogens, wurden die Auswirkungen der fünf Faktorenkomplexe: Sonderstrukturen, Anlagenstruktur, Beschattung, Mahdregime und Einsatz von Pflanzenschutzmitteln erhoben. Die visuelle Darstellung der Einflussfaktoren mittels Netzdiagramm zeigt biodiversitätsbeeinträchtigende Faktoren und ermöglicht so Empfehlungen zur Aufwertung der Biodiversität. Die hier vorgeschlagenen Maßnahmen zielen auf eine Erhöhung der Biodiversität und Minimierung der negativen Auswirkungen der Bewirtschaftung in Erwerbsobstanlagen. Durch eine möglichst große, an die Kultur angepasste Strukturvielfalt soll die Verfügbarkeit von Nistplätzen, Nahrung und Überwinterungsmöglichkeiten für Insekten und Spinnentiere deutlich erhöht werden und damit zur Ausbildung stabiler Populationen führt.

Tracing Safety- and Security-Critical Artifacts and Where to Find Them

Thu, 23 Jul 2026 08:35:17 +0200

Context: Tracing is a core competence in requirements engineering. Particularly, in safety & security critical domains, tracing is often not only beneficial but even required by industry or government standards. In the tracing process, linked artifacts and the activities that process or create them are essential. To capture trace link candidates and provide recommendations to developers, it is necessary to identify which artifacts and activities exist and how they relate to one another. However, there is currently no comprehensive overview of safety & security-relevant artifacts and activities. Objectives: We aim to compile a collection of all relevant artifacts and activities that employ tracing in security- and safety-critical domains. We would also like to suggest potential trace-link candidates to facilitate tracing. Methods: In our approach, we conduct a literature review and examine the well-documented Corona Warn App as the subject of our investigation. Results: We examined n=259publications from safety & security-related traceability research for artifacts and activities. We identified and compiled 437 artifact types and 254 activities into a comprehensive data collection. Our findings include (1) the most frequently appearing artifacts and activities, (2) the most common co-appearing artifacts and activities, and (3) the most frequently appearing artifacts and activities related to specific domains such as military defense, aerospace, and software management and (4) an example how to use our collection on an example to the Corona Warn App. Conclusion: We discuss recommendations for developers, the importance of collaboration and communication in tracing processes, the identification of patterns in artifacts and activities during tracing, and the implications of our findings for industry settings, as well as directions for future work.

Migration und Erwachsenenbildung

Wed, 22 Jul 2026 08:17:42 +0200

IndustryConnect: WI-Forschung mit und für die Praxis

Petra Schubert; Susan P. Williams — Wed, 22 Jul 2026 08:02:44 +0200

Der Beitrag beschreibt ein Rahmenwerk für praxisorientierte Langzeitforschung, das an Boyers vier Scholarships angelehnt ist. Das Modell wird im Rahmen der Initiative IndustryConnect seit mehr als fünf Jahren erfolgreich für die gemeinsame Forschung im Themengebiet Digitaler Arbeitsplatz eingesetzt. Die besonderen Erfolgsfaktoren der gemeinsamen Arbeit zwischen Wissenschaft und Praxis werden erläutert, wie zum Beispiel die Schaffung einer gemeinsamen Begriffswelt und das Anlegen einer gemeinsamen Wissensbasis. Das Rahmenwerk umfasst einen ausgewählten Methodenmix, inklusive der speziell entwickelten Methoden eXperience Fallstudien und Milestories, und der damit verbundenen Methodenausbildung für Doktoranden. Typische Ergebnisse aus dieser Art der Forschung sind Erklärungs- und Klassifikationsmodelle, Methoden und Prototypen, für die exemplarische Publikationen aufgeführt werden. Am Ende des Beitrags findet sich ein Bericht über Erfahrungen und Erkenntnisse aus der gemeinsamen Forschungsarbeit „mit und für die Praxis“ sowie eine Ermutigung, dem Aufruf von Nunamaker et al. zu folgen, die „letzte Meile in der WI-Forschung zu gehen“.

Against Interlocking Forms of Discrimination and Exclusion (in Higher Education): Concepts, Struggles, and Strategies

Stefanie Kröber; Bahar Oghalai — Tue, 21 Jul 2026 11:31:33 +0200

“I have Learned Non-Euclidean Geometry Just from this Book” - Some facets of the correspondence between Friedrich Engel and David Hilbert

Peter Ullrich — Tue, 21 Jul 2026 08:15:28 +0200

Friedrich Engel and David Hilbert learned to know each other at Leipzig in 1885 and exchanged letters in particular during the next 15 years which contain interesting information on the academic life of mathematicians at the end of the 19th century. In the present article we will mainly discuss a statement by Hilbert himself on Moritz asch’s influence on his views of geometry, and on personnel politics concerning Hermann Minkowski and Eduard Study but also Engel himself.

A novel p-harmonic descent approach applied to fluid dynamic shape optimization

Tue, 21 Jul 2026 08:01:47 +0200

We introduce a novel method for the implementation of shape optimization for non-parameterized shapes in fluid dynamics applications, where we propose to use the shape derivative to determine deformation fields with the help of the p− Laplacian for p > 2 . This approach is closely related to the computation of steepest descent directions of the shape functional in the W1,∞ − topology and refers to the recent publication Deckelnick et al. (A novel W1,∞ approach to shape optimisation with Lipschitz domains, 2021), where this idea is proposed. Our approach is demonstrated for shape optimization related to drag-minimal free floating bodies. The method is validated against existing approaches with respect to convergence of the optimization algorithm, the obtained shape, and regarding the quality of the computational grid after large deformations. Our numerical results strongly indicate that shape optimization related to the W1,∞-topology—though numerically more demanding—seems to be superior over the classical approaches invoking Hilbert space methods, concerning the convergence, the obtained shapes and the mesh quality after large deformations, in particular when the optimal shape features sharp corners.

Protistan Predators Outshine Fungi in Forest Soil Activity

Longfei Kang; Kenneth Dumack — Mon, 20 Jul 2026 08:25:00 +0200

Despite extensive research on fungal communities in forest soils, our understanding of the whole eukaryotic diversity and distribution remains limited. Moreover, traditional amplicon sequencing methods often introduce severe PCR and primer biases, further hindering accurate assessment of the microbial community composition in forest soils. To address these challenges, this study used a public metatranscriptomic data set to analyze 51 forest soil samples comprising four countries (Canada, France, Spain, and Sweden). Our results reveal that Arcellinida , a eukaryotic order of shell‐bearing amoebae, represent the most abundant eukaryotic taxon in forest soils, with an average relative abundance of 12.6%. This finding challenges the conventional view that fungi dominate eukaryotic diversity in these ecosystems. Furthermore, our study demonstrates that Arcellinida ( R 2 = 0.066, p = 0.006) and soil pH ( R 2 = 0.126, p < 0.001) are key biological and environmental drivers, respectively, shaping the composition of eukaryotic communities in forest soils, suggesting distinct impact on the microbial community through predation. These findings offer novel insights into the ecological significance of microbial eukaryotes in forest ecosystems and provide a new framework for investigating the predatory dynamics centered on Arcellinida in forest soil microbial networks.

Landscape heterogeneity affects developmental and dispersal‐related traits of a butterfly in agricultural landscapes

Mon, 20 Jul 2026 08:16:42 +0200

The loss and fragmentation of natural habitats due to the intensification of agricultural land use have detrimental impacts on the biodiversity of arthropods. The reduction of natural habitats results in a decreased availability of essential resources, which may select for rapid development and phenotypes enhancing dispersal ability. We here compared replicated populations of the butterfly Coenonympha pamphilus in field‐caught females and their laboratory‐reared offspring across two landscape types: highly fragmented and intensified “modern” and less fragmented “traditional” agricultural landscapes. We also examined the effects of food stress and landscape parameters representing compositional and configurational landscape heterogeneity on intraspecific trait variation at different spatial scales. The differences between the two landscape types in butterfly traits were nonsignificant throughout, but both field‐caught females and their offspring exhibited various responses to the measured landscape parameters. In particular, landscapes with (1) high heterogeneity of habitat patches (i.e., relatively smaller grassland patches with high boundary length), (2) higher proportion of non‐crop habitats (i.e., grassland, forests, and woodland), and (3) lower proportion of crop fields seemed to select for phenotypes enhancing dispersal ability. Flight propensity of male offspring was increased under food stress, indicating plastic responses to resource scarcity. In conclusion, our findings suggest that the compositional and configurational landscape heterogeneity, namely parameters indicative of agricultural intensification, select for enhanced dispersal in C. pamphilus . As higher investment in dispersal often comes at a cost to reproduction, such trait shifts may reduce population viability, which may have important implications for insect declines in agricultural landscapes.

Sleepwalking as a curiosity: visual representations and knowledge on social media

Nico Wettmann; Frederik Peper; Leonie Scheuering — Fri, 17 Jul 2026 10:25:46 +0200

On online platforms, users document and stage sleepwalking episodes in videos, influencing the social understanding of sleepwalking. This article uses digital ethnography to examine how sleepwalking is visually represented on social media and the knowledge these representations convey. The analysis identifies three central themes: first, sleepwalking is presented as a subject for self-observation; second, it is depicted as a humorous violation of social norms; and third, it is portrayed as an eerie spectacle associated with horror. These representations produce and reproduce historical, cultural and medical knowledge about sleepwalking. Finally, we argue that social media presents sleepwalking as a curiosity: a fascinating phenomenon that breaks norms and stimulates public discourse, but which also reinforces myths. The results demonstrate how digital platforms shape the visibility and interpretation of sleepwalking, thereby creating new epistemic spaces. The article concludes by calling for an interdisciplinary debate that combines historical, cultural and medical perspectives.

An Anuran-Based Biotic-Integrity Index for Prioritizing Wetland Conservation Sites in Rwanda

Selina Glebsattel; J. Maximilian Dehling — Thu, 16 Jul 2026 12:54:24 +0200

We introduce an index based on the composition of amphibian communities that can be used to assess and monitor over time the biotic integrity of wetlands and to evaluate the priority of these sites for conservation. The Rwanda Anuran-based Biotic-Integrity Index (RABI) integrates three sub-indices, which reflect the conservation priority of species based on their distribution in Rwanda, their conservation status, and their susceptibility to habitat alteration. The functionality of the RABI was tested on 51 wetland sites distributed over the five ecozones of Rwanda. The wetland sites showed a wide range of RABI values, with marked differences between the different ecozones. The RABI reliably identified sites with a high number of threatened, range-restricted, and habitat-sensitive species and sites with high species richness. Although wetlands in agriculturally exploited areas often had high anuran-species numbers, their assemblages contained mostly widespread generalist species, resulting in lower RABI values compared to sites with lower species numbers but with threatened, specialized species. Wetlands within the four Rwandan national parks had particularly high RABI values, confirming that these areas require special protection. We identified five sites with high conservation value outside the national parks that should be considered for future protection.

Beyond Polishing: An Exploratory Comparison of Editor- and Challenger-Style AI Prompts on Problem Framing in Data Science Education

Chisom Onwumere — Wed, 15 Jul 2026 11:42:35 +0200

Generative AI tutoring tools predominantly refine the wording, structure, and feasibility of a student’s initial problem framing. Whether AI assistance that instead poses counter-proposals – alternative framings, stakeholder perspectives, and questioned assumptions – changes the originality of the resulting framing is an open empirical question for data science education. This thesis investigates that Question in an exploratory study with thirty postgraduate students at Universität Koblenz. Each participant interacted with a bespoke web platform that walked them through three fixed-order stages on a sharedWi-Fi-dormitory dataset description: an Editorstyle AI stage, a Challenger-style AI stage, and a final unassisted synthesis. The final synthesis topic was rated on four dimensions (originality, feasibility, reasoning quality, clarity) by a human expert rater and an LLM second rater (Anthropic Claude) blinded to group assignment. Because the planned counterbalanced within-subjects crossover could not be implemented, participants were sorted post hoc into an Editor-influenced and a Challengerinfluenced group based on triangulated self-reported impact and preference. Topics from the Challenger-influenced group were rated substantially higher on originality (Cohen’s d = 3.67, 95% CI [2.50, 4.84], p < .001, ICC = 0.859); topics from the Editor-influenced group were rated higher on feasibility (d = −2.04, 95% CI [−2.92,−1.16]) and clarity (d = −1.07, 95% CI [−1.84,−0.30]); a secondary unexpected association favoured the Challenger-influenced group on reasoning Quality (d = 1.03, 95% CI [0.27, 1.79]). The latter three dimensions had inter-rater reliability below the pre-specified 0.70 threshold and their effect-size magnitudes are interpreted as exploratory estimates. Perception data and open-ended responses suggested participants treated the two AI styles as functional complements assigned to distinct task-contexts, and 94% indicated interest in an integrated switcher mode. Because the analytic groups were defined by self-report and because the stage order was fixed, these results should be read as associations rather than causal effects of prompt style. The thesis contributes (a) empirical evidence of large betweengroup differences in framing originality consistent with a counter-proposal mechanism; (b) a methodological case study of a hybrid human-LLM rating protocol with dimension-specific reliability documentation; and (c) design directions for educational AI tools that surface, rather than choose for the learner, the kind of cognitive assistance offered.

When and Why to Help: Timing and Reflection Strategies for Calibrated AI Support in Data-Science Problem Framing

Ark Ikhu — Wed, 15 Jul 2026 11:39:35 +0200

The rapid advancement of large language models (LLMs) has introduced powerful artificial intelligence (AI) tools into educational environments. While AI assistants offer potential benefits for learning, concerns about over-reliance, reduced critical thinking, and impaired skill development have emerged. This thesis investigates how the timing of AI support (Just-in-Time vs. Always-On) and reflective mandates (Rationale-Required vs. Rationale-Optional) influence creative performance, learner autonomy, and critical engagement in AI-assisted data-science problem framing. Through a controlled 2x2 within-subjects factorial experimental design with 66 postgraduate participants, the study examines expert-rated idea quality, semantic diversity, perceived agency, AI reliance, cognitive load, and reflective reasoning across four AI-assisted conditions. The results show that Just-in-Time support and required reflection are independently associated with higher idea quality, greater agency, lower AI dependence, and more selective engagement with AI suggestions. The study does not assess delayed or long-term learning transfer; future work with longitudinal designs is needed to determine whether the immediate benefits observed here translate into durable skill development.

Initial Upper Palaeolithic lithic industry at Cueva Millán in the hinterlands of Iberia

Tue, 14 Jul 2026 13:46:00 +0200

The extended period of coexistence between Neanderthals and Homo sapiens in Europe coincided with the emergence of regionally distinctive lithic industries, signalling the onset of the Upper Palaeolithic. The Iberian Peninsula was on the periphery of pioneering Upper Palaeolithic developments, with archaeological remains primarily found in northern territories. We report the discovery of an initial Upper Palaeolithic lithic industry at Cueva Millán in the hinterlands of Iberia. This industry, termed here Arlanzian, not only represents the earliest and southernmost evidence of such industries in Iberia but also lacks a direct counterpart. However, it exhibits chronological and technological parallels with the lithic industries associated with the earliest expansion of Homo sapiens throughout Eurasia. We interpret this as potential evidence of its intrusive nature, but not necessarily associated with a migration event, as more complex scenarios derived from inter-population connectivity must be also considered. The biological identity of the Arlanzian makers remains unknown, but they coexisted with declining Neanderthal groups from neighbouring territories.

A globally declining endemic under pressure: effects of habitat and climate change on Citril Finches in the Bavarian Alps

Tue, 14 Jul 2026 13:05:57 +0200

The ongoing global biodiversity loss is a major challenge of our time. It affects all groups of organisms, but is particularly well documented in birds. The Citril Finch Carduelis citrinella , one of the few bird species endemic to Europe, is one example currently suffering from substantial population declines. We here set out to document its population development over the past 14 years (records in 2011 and 2025) in a part of the Bavarian Alps and to identify the environmental factors being crucial for the occurrence of the species. In our study area around Garmisch-Partenkirchen, the Citril Finch has declined by about 48% between 2011 and 2025. Currently occupied territories, as compared to former territories or control sites, were characterised by a richer supply of flowers, particularly of the Asteraceae family, higher numbers of solitary trees, and a concentration on south-facing slopes. Moreover, areas with stable rather than declining populations showed a shorter distance to the nearest water source, a higher proportion of Mountain Pine, and a longer distance to forest edges. These findings indicate negative impacts of reduced grazing intensity and climate change (drought periods). Our results highlight that preserving the Citril Finch’s alpine habitats depends strongly on traditional, low-intensity farming and appropriate pasture care to maintain the necessary flower-rich, open to semi-open habitats with solitary trees. Providing supplementary water sources would help to counteract the increasing water shortage caused by climate change. Given the documented population decline, targeted conservation measures in the Bavarian Alps, the species’ stronghold in Germany, are urgently needed.

Location-specific wage effects from offshoring and backshoring

Torben Dall Schmidt; Timo Mitze — Mon, 13 Jul 2026 09:25:05 +0200

Offshoring and backshoring are essential components of firms’ internationalization strategies and influence the spatial organization of global value chains (GVCs). This paper examines how such strategies affect the wage development of incumbent workers in multinational firms across urban and rural labor markets. First, we develop a theoretical framework that extends standard urban wage models by incorporating GVC-induced productivity and cost effects, yielding spatially differentiated wage responses to firms’ strategic choices. Second, we empirically estimate the relationship between wage dynamics and GVC reorganization combining data on offshoring and backshoring activities by Danish firms with linked employer-employee register data for the period 2001–2016. Methodically, we apply a difference-in-difference type treatment model with internationalization strategies as treatment variables. The results show GVC-related wage growth heterogeneity across space. Offshoring raises wage growth by 2.4 % in urban areas but by roughly 30 % in rural areas relative to average wage growth of incumbent workers in non-internationalizing firms. In contrast, backshoring increases wage growth vis-à-vis comparison workers by 10 % in urban areas compared to 1.5 % in rural areas. Together with the theoretical model predictions, these findings indicate that cost-driven gains from offshoring accrue disproportionately to peripheral regions, while productivity gains from recombining production stages through backshoring are concentrated in dense urban environments, where agglomeration economies and knowledge spillovers amplify returns.

The transformative potential of AI in software engineering: a case study on LeetCode and ChatGPT

Manuel Merkel; Jens Dörpinghaus — Mon, 13 Jul 2026 08:51:33 +0200

The recent surge in the field of generative artificial intelligence (GenAI) has the potential to bring about transformative changes across a range of sectors, including software engineering and education. As GenAI tools, such as OpenAI’s ChatGPT, are increasingly utilised in software engineering, it becomes imperative to understand the impact of these technologies on the software product. This study employs a methodological approach, comprising web scraping and data mining from LeetCode, with the objective of comparing the software quality of Python programs produced by LeetCode users with that generated by GPT-4o. In order to gain insight into these matters, this study addresses the question whether GPT-4o produces software of superior quality to that produced by humans. The findings indicate that GPT-4o does not present a considerable impediment to code quality, understandability, or runtime when generating code on a limited scale. Indeed, the generated code even exhibits significantly better values across all the three code quality dimensions in comparison to the user-written code. However, no significantly superior values were observed for the generated code in terms of memory usage in comparison to the user code, which contravened the expectations. Furthermore, it will be demonstrated that GPT-4o encountered challenges in generalising to problems that were not included in the training data set. This contribution presents a first large-scale study comparing generated code with human-written code based on LeetCode platform based on multiple measures including code quality, code understandability, time behaviour and resource utilisation. All data is publicly available for further research.

Single-Particle X‑ray Scattering Reveals a High Local Supersaturation of Precursors as the Origin of CoO Assembly Formation

Mon, 13 Jul 2026 08:14:36 +0200

Single-particle small-angle X-ray scattering (SP-SAXS) at X-ray free electron lasers (XFELs) enables quantitative analysis of morphological heterogeneity that is fundamentally inaccessible to ensemble-averaged in situ techniques. By recording diffraction snapshots from isolated particles, SP-SAXS resolves low-contrast, less abundant, or transient species within heterogeneous particle populations that would otherwise remain hidden to conventional X-ray techniques. We demonstrate this unique capability by investigating the solvothermal formation of CoO nanocrystal assemblies from a Co(acac)3 precursor in benzyl alcohol. The single-particle data revealed amorphous, uniform-density Co(acac)2 spheres as transient intermediates that directly crystallize into cavernous CoO nanocrystal assemblies, explaining why CoO forms as hierarchical aggregates rather than as isolated nanocrystals. These results establish SP-SAXS as a uniquely powerful framework for uncovering nonclassical nanoparticle formation pathways hidden in ensemble measurements.