@article{64979,
  abstract     = {{We investigate homogeneous coupled cell systems with high-dimensional internal dynamics. In many studies on network dynamics, the analysis is restricted to networks with one-dimensional internal dynamics. Here, we show how symmetry explains the relation between dynamical behavior of systems with one-dimensional internal dynamics and with higher dimensional internal dynamics, when the underlying network topology is the same. Fundamental networks of homogeneous coupled cell systems (B. Rink, J. Sanders. Coupled Cell Networks and Their Hidden Symmetries. SIAM J. Math. Anal. 46.2 (2014)) can be expressed in terms of monoid representations, which uniquely decompose into indecomposable subrepresentations. In the high-dimensional internal dynamics case, these subrepresentations are isomorphic to multiple copies of those one computes in the one-dimensional internal dynamics case. This has interesting implications for possible center subspaces in bifurcation analysis. We describe the effect on steady state and Hopf bifurcations in l-parameter families of network vector fields. The main results in that regard are that (1) generic one-parameter steady state bifurcations are qualitatively independent of the dimension of the internal dynamics and that, (2) in order to observe all generic l-parameter bifurcations that may occur for internal dynamics of any dimension, the internal dynamics has to be at least l-dimensional for steady state bifurcations and 2l-dimensional for Hopf bifurcations. Furthermore, we illustrate how additional structure in the network can be exploited to obtain even greater understanding of bifurcation scenarios in the high-dimensional case beyond qualitative statements about the collective dynamics. One-parameter steady state bifurcations in feedforward networks exhibit an unusual amplification in the asymptotic growth rates of individual cells, when these are one-dimensional (S. von der Gracht, E. Nijholt, B. Rink. Amplified steady state bifurcations in feedforward networks. Nonlinearity 35.4 (2022)). As another main result, we prove that (3) the same cells exhibit this amplifying effect with the same growth rates when the internal dynamics is high-dimensional.}},
  author       = {{von der Gracht, Sören and Nijholt, Eddie and Rink, Bob}},
  issn         = {{0960-0779}},
  journal      = {{Chaos, Solitons & Fractals}},
  keywords     = {{Coupled cell systems, Network dynamics, Dimension reduction, Bifurcation theory, Symmetry, Monoid representation theory}},
  publisher    = {{Elsevier BV}},
  title        = {{{Homogeneous coupled cell systems with high-dimensional internal dynamics}}},
  doi          = {{10.1016/j.chaos.2026.118196}},
  volume       = {{208}},
  year         = {{2026}},
}

@article{64978,
  abstract     = {{The degrees of freedom (DoFs) of light determine the maximum number of independent signal
channels an optical system can support. However, the polarization DoF is intrinsically limited to two by
orthogonality, which causes unavoidable crosstalk and often forces position multiplexing, where different
channels are assigned to distinct spatial locations to suppress crosstalk. This research introduces a multilayer
synchronous polarization projection method that fundamentally increases the DoF for polarization
multiplexing. The DoF equals twice the number of projection layers. We experimentally demonstrate six-
channel polarization multiplexing holography without position multiplexing. The six-channel multiplexing
results indicate that our approach exceeds the conventional polarization multiplexing method, yielding an
average 3.79 dB improvement in extinction ratio across the six channels. Compared with the theoretical
limit of traditional polarization multiplexing, our method reduces crosstalk by an average of 6.52 dB across
all channels in a seven-channel design. The polarization projection method breaks the DoF limitation
of polarization multiplexing, opening a path toward high-dimensional photonic information encoding for
communication, encryption, and imaging.}},
  author       = {{Jin, Xiao and Zentgraf, Thomas}},
  issn         = {{2577-5421}},
  journal      = {{Advanced Photonics}},
  number       = {{02}},
  publisher    = {{SPIE-Intl Soc Optical Eng}},
  title        = {{{Increasing the design degree of freedom for polarization through multilayer synchronous polarization projection}}},
  doi          = {{10.1117/1.ap.8.2.026010}},
  volume       = {{8}},
  year         = {{2026}},
}

@inbook{60018,
  author       = {{Grauthoff, Fabian and Kreter, Maximilian}},
  booktitle    = {{Speak Up! Einblicke in das ostbelgische Innovationslabor zum Umgang mit Fake News und Hate Speech}},
  editor       = {{Kirschner, Sabrina and Lask, Tomke}},
  pages        = {{247--278}},
  publisher    = {{transcript}},
  title        = {{{"I WON THIS ELECTION, BY A LOT!" - Fake News und die Frage nach Wahrheit. Donald Trump durch die Linsen von Arendt und Rüsen}}},
  year         = {{2026}},
}

@book{65056,
  editor       = {{Kalusche, Katinka and Bormuth, Heike and Meyer-Hamme, Johannes}},
  title        = {{{Selbstständig. Geschichtslernen als Befähigung zum historischen Denken. Festschrift für Andreas Körber}}},
  year         = {{2026}},
}

@unpublished{65073,
  abstract     = {{We study the large-time behavior of the continuous-time heat kernel and of solutions to the heat equation on homogeneous trees. First, we derive sharp asymptotic formulas for the heat kernel as $t\to\infty$. Second, using them, we show that solutions with initial data in weighted $\ell^1$ classes, asymptotically factorize in $\ell^p$ norms, $p\in[1,\infty]$, as the product of the heat kernel, times a $p$-mass function, dependent on the initial condition and $p$. The  $p$-mass function is described in terms of boundary averages associated with Busemann functions for $p<2$, while for $p\ge 2$, it is expressed through convolution with the ground spherical function. For comparison, the case of the integers shows that a single constant mass determines the asymptotics of solutions to the heat equation for all $p$, emphasizing the influence of the graph geometry on heat diffusion.}},
  author       = {{Papageorgiou, Efthymia}},
  booktitle    = {{2603.11232}},
  title        = {{{Long-time asymptotics for the heat kernel and for heat equation solutions on homogeneous trees}}},
  year         = {{2026}},
}

@article{65095,
  abstract     = {{<jats:p>
                    We provide experimental validation of tight entropic uncertainty relations for the Shannon entropies of observables with mutually unbiased eigenstates in high dimensions. In particular, we address the cases of dimensions
                    <a:math xmlns:a="http://www.w3.org/1998/Math/MathML">
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                      </a:mrow>
                    </a:math>
                    , 4, and 5 and consider from 2 to
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                      <b:mrow>
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                    mutually unbiased bases. The experiment is based on pulsed frequency bins measured with a multioutput quantum pulse gate, which can perform projective measurements on a complete high-dimensional basis in the time-frequency domain. Our results fit the theoretical predictions: the bound on the sum of the entropies is never violated and is saturated by the states that minimize the uncertainty relations.
                  </jats:p>}},
  author       = {{Serino, Laura Maria and Chesi, Giovanni and Brecht, Benjamin and Maccone, Lorenzo and Macchiavello, Chiara and Silberhorn, Christine}},
  issn         = {{2469-9926}},
  journal      = {{Physical Review A}},
  number       = {{3}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Experimental entropic uncertainty relations in dimensions three to five}}},
  doi          = {{10.1103/f6c4-jtlc}},
  volume       = {{113}},
  year         = {{2026}},
}

@unpublished{61151,
  abstract     = {{In this paper, we discuss the application of retrospective video recall for the assessment of cognitive processes in explanatory interactions, such as understanding and mental models. Our purpose is to reflect on the benefits and limitations of video recall compared to another self-report method, ‘thinking-aloud’. To do so, we reveal empirical results from the application of video recall in three interdisciplinary research projects that applied the method for the qualitative and quantitative assessment of cognitive and behavioral phenomena in everyday explanations. In all three projects, video recall was applied as a post-hoc procedure following the recording of dyadic face-to-face explanations of board games. The design of the video recall procedure differed between individual projects because they pursued different research objectives – that is the investigation of (1) an interlocutor's multimodal signals of understanding, (2) the change in assumptions about an interlocutor's dispositional and situational knowledge, and (3) the differentiated assessment of an interlocutor's developing understanding of domain knowledge aspects by distinguishing between mechanistic and functional explanatory stances. By discussing the benefits and the limitations of each procedure, this article provides critical reflections on video recall as a versatile research method applied for the analysis of human multimodal behavior in interaction and cognitive processing.}},
  author       = {{Lazarov, Stefan Teodorov and Schaffer, Michael and Gladow, Viviane and Buschmeier, Hendrik and Buhl, Heike M. and Grimminger, Angela}},
  pages        = {{29}},
  title        = {{{Retrospective video recall for analyzing cognitive processes in naturalistic explanations}}},
  year         = {{2026}},
}

@article{65182,
  abstract     = {{<jats:p>The aggregation of rating metrics in reputation systems is crucial for mitigating information overload by condensing customer rating distributions into singular valence scores. While platforms typically employ technical aggregation functions, such as the arithmetic mean to capture product quality, it remains unclear whether these functions align with customers' innate aggregation patterns. To address this knowledge gap, we designed a controlled economic decision experiment to elicit customers' aggregation principles by analyzing their product ranking decisions and contrasting these with various reference functions. Our findings indicate that, on average, customers aggregate rating information in accordance with the arithmetic mean. However, a granular analysis at the individual level reveals significant heterogeneity in aggregation behavior, with a substantial cluster exhibiting binary patterns that focus equally on negative (1-2 star) and positive (4-5 star) ratings. Additional clusters concentrate on negative feedback, particularly 1-star ratings or 1-2 star ratings collectively. Notably, these inherent aggregation patterns exhibit stability across variations in numerical information presentation and are not significantly influenced by individual characteristics, such as online shopping experience, risk attitudes, or demographics. These findings suggest that while the arithmetic mean captures average consumer behavior, platforms could benefit from offering customizable aggregation options to better cater to diverse user preferences for processing rating distributions. By doing so, platforms can enhance the effectiveness of their reputation systems and improve the overall quality of decision-making for consumers.</jats:p>}},
  author       = {{van Straaten, Dirk and Mir Djawadi, Behnud and Melnikov, Vitalik and Hüllermeier, Eyke and Fahr, René}},
  journal      = {{SSRN Electronic Journal}},
  publisher    = {{Elsevier BV}},
  title        = {{{Aggregation Processes in Customer Rating Systems - Insights from an Economic Decision Experiment}}},
  doi          = {{http://dx.doi.org/10.2139/ssrn.6201258}},
  year         = {{2026}},
}

@article{65181,
  abstract     = {{<jats:p>In many Western societies, mass immigration has been one of the most divisive policy issues in recent years. Seemingly moderate inflows of migrants can have substantial demographic consequences in the long run, due to (1) higher fertility of the migrant population, (2) its younger age distribution, and (3) the possibility of family reunification. Yet, demography hardly appears in the policy debate, even in media outlets that are critical of mass immigration. This may indicate that the mechanics of population dynamics are not widely understood. We design a laboratory experiment in which we confront subjects with 30 different migration scenarios. Subjects have to decide when to stop a given inflow of migrants to achieve a target share of migrants after 60 years. In line with all our pre-registered hypotheses, in scenarios that contain elements of usual mass immigration the growth of the migrant population is systematically underestimated. This bias is even stronger in scenarios that closely resemble the German situation since the opening of the borders during the 2015 refugee crisis.</jats:p>}},
  author       = {{Abbink, Klaus and Mir Djawadi, Behnud}},
  journal      = {{SSRN Electronic Journal}},
  publisher    = {{Elsevier BV}},
  title        = {{{Migration and Long-Term Demographic Change: Can We Control the Numbers?}}},
  doi          = {{http://dx.doi.org/10.2139/ssrn.6343618}},
  year         = {{2026}},
}

@article{64863,
  abstract     = {{Traditional dyadic customer-provider interactions are being shifted to polyadic interactions involving diverse participants in digital service ecosystems. Especially, artificial intelligence (AI) is increasingly integrated into these ecosystems, so that they comprise non-human participants (e.g., AI-based chatbots)—fundamentally altering the nature of value (co-)creation. While existing literature examines human-to-human interactions, knowledge of service interactions between human actors and AI-based systems is still underexplored. To address this research gap, we develop a taxonomy, comprising six iterations, that explores the peculiarities of AI as either a resource or a (non-human) agent in digital service ecosystems. We evaluate our taxonomy using a multiple case study and derive the four archetypes of AI in digital service ecosystems: (1) discriminative experience enhancer, (2) protective ecosystem orchestrator, (3) ecosystem innovation companion, and (4) personalized service composer. Our results extend the knowledge on service science by showing how AI-based systems—discriminative or generative, and focusing on the interaction in the ecosystem or the individual service encounter—assume the role of resources and non-human agents. Researchers and practitioners can utilize our results to augment their ecosystems with AI.</jats:p>}},
  author       = {{Hansmeier, Philipp and Schäfer, Jannika Marie and zur Heiden, Philipp}},
  issn         = {{1019-6781}},
  journal      = {{Electronic Markets}},
  number       = {{1}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Artificial intelligence in digital service ecosystems—Towards a taxonomy and archetypes}}},
  doi          = {{10.1007/s12525-026-00879-y}},
  volume       = {{36}},
  year         = {{2026}},
}

@book{65256,
  editor       = {{Scheytt, Johann Christoph and Kress, Christian and Berroth, Manfred and Pachnicke, Stephan and Witzens, Jeremy}},
  isbn         = {{9783032083395}},
  publisher    = {{Springer Nature Switzerland}},
  title        = {{{Electronic-Photonic Integrated Systems for Ultrafast Signal Processing}}},
  doi          = {{10.1007/978-3-032-08340-1}},
  year         = {{2026}},
}

@misc{65356,
  author       = {{Droß-Krüpe, Kerstin and Ghetta, Marcello}},
  booktitle    = {{RAC}},
  pages        = {{968--980}},
  publisher    = {{Hiersemann}},
  title        = {{{Viehhaltung }}},
  volume       = {{33}},
  year         = {{2026}},
}

@inbook{65406,
  author       = {{Jacke, Christoph}},
  booktitle    = {{Angriff aufs Schlaraffenland. Ein Deutschpunk-Mixtape.}},
  editor       = {{Engelmann, Jonas}},
  isbn         = {{978-3-95575-257-6}},
  pages        = {{65--68}},
  publisher    = {{Ventil Verlag}},
  title        = {{{Palais Schaumburg: Gute Luft (1981). Grünes Winkelkanu im Tischtenniskeller.}}},
  year         = {{2026}},
}

@article{65443,
  abstract     = {{<jats:title>Abstract</jats:title>
                  <jats:p>Social media is integral to adolescents’ daily lives and plays an important role in their health- and fitness-related behavior, particularly through trends such as #fitspiration, a portmanteau of “fit” and “inspiration.” This trend has become a prominent aspect of adolescents’ fitness culture. Empirical studies demonstrate that while #fitspiration holds the potential to motivate adolescents to be physically active, it also perpetuates gender-stereotyped, predominantly White, ableist, and normative body ideals associated with fitness and an idealized weight. This trend can be linked to an increased risk of body image concerns or disordered eating among adolescents. Understanding adolescents’ engagement with fitspiration content is crucial for tailoring health and media literacy education within physical education. Therefore, a systematic review of qualitative and quantitative studies was conducted. A search of five electronic databases yielded 312 abstracts, of which 12 met the inclusion criteria. The analysis of the selected studies was based on thematic analysis and included both primary and secondary data. Seven analytical themes emerged: (1) 37–56% of adolescents actively engage with fitspiration content on social media; (2) it fulfills their need for informal and accessible participation; (3) it fosters a sense of social connection; (4) they derive inspiration from peers and influencers; (5) they aspire to idealized body standards; (6) they seek quick solutions when dissatisfied with their bodies; and (7) a few become demotivated and critical when unable to achieve these ideals. Consequently, educators should balance the potential benefits with media literacy interventions to mitigate risks such as body image issues and eating disorders.</jats:p>}},
  author       = {{Grimminger-Seidensticker, Elke and Korte, Johanna}},
  issn         = {{2509-3142}},
  journal      = {{German Journal of Exercise and Sport Research}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Adolescents’ engagement with #fitspiration content—a systematic review of qualitative and quantitative studies and pedagogical implications for physical education Der Umgang von Jugendlichen mit Inhalten zu #fitspiration - Ein systematisches Review qualitativer und quantitativer Studien sowie pädagogische Implikationen für den Sportunterricht}}},
  doi          = {{10.1007/s12662-026-01107-7}},
  year         = {{2026}},
}

@article{65375,
  abstract     = {{<jats:title>Abstract</jats:title>
                  <jats:p>Vitamin D has been associated with depression, potentially via anti-inflammatory mechanisms, yet data is scarce, particularly in adolescence. We investigated (1) whether lower vitamin D status is associated with greater depression severity and (2) whether this association is statistically moderated by inflammation in patients of a child and adolescent psychiatry department. At admission fasting morning venous blood was drawn. Serum vitamin D (25(OH)D) and C-reactive protein (CRP) were analyzed in all participants [n=465 (64.7%♀; 11.3-18.9 years)]. In a subsample [n=177], we additionally measured tumor necrosis factor-alpha, interferon-gamma and interleukin (IL)-1β, IL-6, IL-8, IL-10. Depression severity was assessed by the Beck Depression Inventory-II (BDI-II) [n=450], the Diagnostic System for Mental Disorders in Childhood and Adolescence via self-assessment (DISYPS Self) [n=441], and parent-assessment (DISYPS Proxy) [n=422]. Overall, 43.2% [n=201] were at risk for vitamin D deficiency (&lt;30nmol/L), and 73.5%-83.2% –depending on assessment tool– showed at least mild depression. Linear regression revealed an inverse association between 25(OH)D and BDI-II in both crude and CRP-adjusted full-sample models. Logistic regressions showed a robust inverse association between 25(OH)D and DISYPS Proxy, but not for DISYPS Self. Although 25(OH)D was inversely correlated with some pro-inflammatory markers, neither their inclusion in regression models nor formal mediation analyses supported inflammation as a mediator of the vitamin D–depression association. Overall, our results suggest that vitamin D relates modestly to both depression and inflammation in adolescence. However, based on the measured parameters, we cannot confirm that anti-inflammatory effects are the link between vitamin D and depression.</jats:p>}},
  author       = {{Schlarbaum, Laura and Jankovic, Nicole and Bühlmeier, Judith and Engler, Harald and Hirtz, Raphael and Grasemann, Corinna and Peters, Triinu and Hinney, Anke and Antel, Jochen and Hebebrand, Johannes and Föcker, Manuel and Libuda, Lars}},
  issn         = {{0007-1145}},
  journal      = {{British Journal of Nutrition}},
  pages        = {{1--37}},
  publisher    = {{Cambridge University Press (CUP)}},
  title        = {{{Does inflammation explain the association between vitamin D and depression? Results of a cross-sectional study in children and adolescents}}},
  doi          = {{10.1017/s0007114526106928}},
  year         = {{2026}},
}

@inbook{57405,
  author       = {{Huybrechts, Yves}},
  booktitle    = {{Les noms de lieux à Bruxelles. Enjeux passés et présents}},
  editor       = {{Kesteloot, Chantal and Degryse, Iadine and Wayens, Benjamin and Matthijs, Degraeve}},
  pages        = {{239--241}},
  publisher    = {{Éditions de l'Université de Bruxelles}},
  title        = {{{Focus. La rue de Brabant ou la rue de Bavière, vestiges d'un souverain 'étranger`aux Pays-Bas espagnols}}},
  volume       = {{8}},
  year         = {{2026}},
}

@book{55650,
  editor       = {{Eke, Norbert Otto and Ludwig , Janine   and  Vaßen, Florian  }},
  pages        = {{172}},
  title        = {{{1.	Heiner-Müller-Jahrbuch 1: Heiner Müllers Natur.}}},
  year         = {{2025}},
}

@inbook{57020,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>In this symposium we investigate students’ agency of selecting and using (digital) resources for developing their own learning paths. For that, we first review the literature related to students’ selection and use of resources in mathematics education in different pedagogical settings (presentation 1). Second, we develop insights from the different studies that participate in this symposium (presentation 2–6), at school as well as at university level. Results show that attempts have been made to provide students opportunities to develop agency of their mathematics learning, in particular with the development and provision of numerous digital tools and learning resources at university level and related to innovative pedagogical approaches. At the same time, it is not obvious how these tools and resources help students to develop deeper conceptual understandings. Certainly, students often ‘demand’ more student-centered and autonomous education approaches (e.g., at university level), also in mathematics education. Further, it seems that authentic problem-based education approaches are more motivating for students. These ‘innovative’ approaches necessitate particular types of structure and support for students. Moreover, they require different ways of providing resources that students can and want to interact with, and that help students to navigate through the curriculum to develop their own learning paths. At the same time, teachers also need support on how to orchestrate student learning with the available resources in such environments, so to be able to attend to students’ individual needs. The symposium comprised altogether six presentations:</jats:p><jats:p>Birgit Pepin &amp; Sebastian Rezat: Students’ agency of selecting and using (digital) resources for developing their own learning paths: An overview</jats:p><jats:p>Annalisa Cusi &amp; Agnese I. Telloni: Learning through digital curriculum resource design: students’ reflections on their role as designers</jats:p><jats:p>Vilma Mesa, Lelia Burley-Sanford, Xinyi Hao, &amp; Carlos Quiroz: Interactive features in university textbooks and their use by teachers and students</jats:p><jats:p>Sebastian Rezat: Fostering university students’ reading and understanding of mathematical text in a flipped classroom approach with a digital marking tool</jats:p><jats:p>Birgit Pepin &amp; Ulises Salinas: Challenge/problem-based mathematics learning at university level: The case of the modeling week</jats:p><jats:p>Farzad Radmehr: Problem-posing: An inclusive activity for improving teaching and learning of mathematics at university level</jats:p>}},
  author       = {{Pepin, Birgit and Rezat, Sebastian}},
  booktitle    = {{Recent Advances in Mathematics Textbook Research and Development}},
  editor       = {{Qi, Chunxia and Fan, Lianghuo and Liu, Jian and Liu, Qimeng and Dong, Lianchun}},
  isbn         = {{9789819784257}},
  pages        = {{123–126}},
  publisher    = {{Springer Nature}},
  title        = {{{Symposium—Towards innovative practices in mathematics education: Teachers’ and students’ choice and use of digital resources}}},
  doi          = {{10.1007/978-981-97-8426-4_17}},
  year         = {{2025}},
}

@inbook{58313,
  author       = {{Mildorf, Jarmila}},
  booktitle    = {{Pandemic Storytelling}},
  editor       = {{Alber, Jan and de Muijnck, Deborah and Jumpertz, Jessica }},
  isbn         = {{978-90-04-51985-5 }},
  pages        = {{83--96}},
  publisher    = {{Brill}},
  title        = {{{Crisis and Creativity: Poetry in Times of Corona}}},
  volume       = {{3}},
  year         = {{2025}},
}

@inbook{58398,
  author       = {{Leineweber, Jonas}},
  booktitle    = {{Immaterielles Kulturerbe und Regionale Identität. Schützenwesen in Nordwestdeutschland}},
  editor       = {{Leineweber, Jonas and Seng, Eva-Maria}},
  isbn         = {{978-3-8376-6126-2}},
  pages        = {{67--97}},
  publisher    = {{transcript}},
  title        = {{{Reflexion – Repräsentation – Partizipation. Das Aufnahmeverfahren in das Bundesweite Verzeichnis des Immateriellen Kulturerbes und der Bewerbungsprozess des Schützenwesens}}},
  year         = {{2025}},
}