Fakultäten der Universität Bonn

Developing zoo visitors' interest in biodiversity conservation – An exploratory study on the role of animal encounters

Fri, 07 Aug 2026 00:00:00 GMT

Developing zoo visitors' interest in biodiversity conservation – An exploratory study on the role of animal encounters Schilbert, Jana The biodiversity crisis represents one of the greatest challenges facing contemporary society. As educational institutions, zoos seek to address the loss of biological diversity through educational initiatives that place biodiversity conservation at the centre. Learning outside formal educational programmes in zoos is largely driven by visitors' prior interests ('free-choice learning'). These interests are primarily directed towards animals and encounters with them, rather than ecology or biodiversity and its conservation. To engage visitors with the topic of biodiversity conservation nonetheless, interest in biodiversity conservation must be deliberately fostered, because interest is a fundamental prerequisite for self-directed learning.
Against this background, the present research project investigates how unguided free-choice zoo visits can be designed to promote interest in biodiversity conservation and if visitors' prior interest in animals and animal encounters can be leveraged in this process. The theoretical framework of the project is provided by the Person–Object Theory of Interest (POI). The aim of this exploratory research was first to investigate interest during unguided free-choice zoo visits and the role of animal encounters. Moreover, biodiversity conservation as an abstract object of interest was to be examined. Ultimately, data-based design hypotheses regarding how free-choice learning environments in zoos should be designed to foster interest in biodiversity conservation were to be derived.
To investigate the promotion of interest in biodiversity conservation, five qualitative studies were conducted: (I) a systematic literature review; (II) an observational study with visitors at the tiger enclosure; (III) an interview study with visitors at the tiger enclosure; (IV) an interview study with zoo professionals; and (V) an interview study with visitors concerning the zoo visit as a whole. Data were analysed using qualitative content analysis.
The findings confirm that visitors' interest in animals is highly pronounced and is primarily stimulated by the animals' physical characteristics and behaviour. Features of the learning environment, such as opportunities for active visitor participation through e.g. signage providing prompts for observational activities or reflection, also have the potential to promote the development of interest. By contrast, interest in biodiversity conservation is considerably less pronounced. Visitors' subjective evaluation of animal welfare influences whether they engage with biodiversity conservation at all, thereby determining whether the development of interest in this topic can occur.
When visitors do engage with biodiversity conservation, their attention is predominantly focused on issues related to threats to biodiversity. Zoo professionals, in contrast, emphasise that engaging more broadly with the topic is essential for understanding biodiversity conservation; this should also encompass the ecosystem level as well as content domains such as nature's contributions to people, the state of biodiversity, conservation measures, and the interrelationships between these areas.
Although zoos provide a wide range of opportunities for engaging with biodiversity conservation, visitors rely predominantly on interpretive signage. Animal encounters themselves, whose educational potential is regarded as particularly high by zoo professionals, rarely lead directly to engagement with biodiversity conservation.
By identifying factors that influence the development of interest during unguided free-choice zoo visits involving animal encounters, and by conceptualising biodiversity conservation as an abstract object of interest, this research made a fundamental contribution to interest research. Based on these findings, evidence-based design hypotheses were developed regarding the promotion of interest in biodiversity conservation. These design hypotheses provide a foundation for the development of learning opportunities that foster interest in biodiversity conservation during unguided free-choice zoo visits. In this way, the study also contributes to the further development of educational practice.; Die Förderung von Interesse an Biodiversitätsschutz bei Zoobesucher*innen – Eine explorative Studie über die Rolle von Tierbegegnungen
Die Biodiversitätskrise ist eine der größten Herausforderungen der heutigen Gesellschaft. Als Lernorte verfolgen Zoos das Ziel, dem Verlust biologischer Vielfalt durch Bildungsarbeit entgegenzuwirken und dabei Biodiversitätsschutz thematisch in den Fokus zu stellen. Lernen außerhalb von Bildungsprogrammen im Zoo wird stark durch das individuelle Interesse der Besucher*innen gesteuert ('free-choice learning'). Dieses Interesse richtet sich hauptsächlich auf Tiere und Tierbegegnungen, weniger auf ökologische Zusammenhänge oder Biodiversität und ihren Schutz. Um das Thema Biodiversitätsschutz dennoch vermitteln zu können, muss das Interesse daran gezielt gefördert werden, da Interesse eine zentrale Grundvoraussetzung für selbstgesteuertes Lernen ist.
Vor diesem Hintergrund untersucht das vorliegende Forschungsprojekt wie ungeführte free-choice-Zoobesuche gestaltet werden können, um das Interesse am Biodiversitätsschutz zu fördern, und ob das bestehende Interesse an Tieren und Tierbegegnungen hierfür genutzt werden kann. Den theoretischen Rahmen des Projekts bildet die Person-Objekt-Theorie des Interesses (POI). Das Ziel dieser explorativen Forschungsarbeit bestand zunächst darin, Interesse in ungeführten free-choice-Zoobesuchen und die Rolle von Tierbegegnungen genauer zu untersuchen. Außerdem sollte Biodiversitätsschutz als abstrakter Interessengegenstand genauer analysiert werden. Schließlich sollten datenbasierte Gestaltungshypothesen abgeleitet werden, wie free-choice-Lernumgebungen in Zoos gestaltet sein sollten, um Interesse an Biodiversitätsschutz zu fördern.
Zur Untersuchung der Interessenförderung an Biodiversitätsschutz wurden fünf qualitative Studien durchgeführt: (I) ein systematisches Literaturreview; (II) eine Beobachtungsstudie mit Besucher*innen an einem Tigergehege; (III) eine Interviewstudie mit Besucher*innen an demselben Tigergehege; (IV) eine Interviewstudie mit Zooexpert*innen; und (V) eine Interviewstudie mit Besucher*innen hinsichtlich ihres gesamten Zoobesuchs. Die Datenanalyse erfolgte mit Hilfe einer qualitativen Inhaltsanalyse.
Die Studien bestätigen, dass das Interesse an Tieren sehr stark ausgeprägt ist und dabei vor allem Aussehens- und Verhaltensmerkmale der Zootiere interessenförderlich sind. Auch Merkmale der Lernumgebung, wie aktive Besucher*innenbeteiligung, z. B. durch Texttafeln mit der Aufforderung zur gezielten Tierbeobachtung oder mit Reflektionsanstößen, können die Interessengenese fördern. Dahingegen ist das Interesse an Biodiversitätsschutz deutlich schwächer ausgeprägt. Die subjektive Bewertung des Tierwohls beeinflusst maßgeblich, ob es zu einer Auseinandersetzung mit Biodiversitätsschutz als Grundlage für eine Interessengenese kommt.
Bei der Auseinandersetzung mit Biodiversitätsschutz stehen Bedrohungsthemen im inhaltlichen Fokus der Besucher*innen. Zooexpert*innen betonen hingegen, dass eine breitere inhaltliche Auseinandersetzung wichtig ist, um Biodiversitätsschutz zu verstehen; diese sollte auch die Ökosystem-Ebene und Themenbereiche wie Beiträge der Natur für den Menschen, Biodiversitätszustand oder Schutzmaßnahmen sowie deren Zusammenhänge umfassen.
Obwohl eine Vielzahl potentieller Angebote zur Auseinandersetzung mit Biodiversitätsschutz im Zoo vorhanden sind, nutzen Besucher*innen vorwiegend Schautafeln. Die Tierbegegnungen an sich, deren Bildungspotential von Zooexpert*innen als besonders hoch bewertet wird, führen selten direkt zu einer Auseinandersetzung mit Biodiversitätsschutz.
Durch die Identifikation von Faktoren, die die Interessenentwicklung in ungeführten free-choice-Zoobesuchen mit Tierbegegnungen beeinflussen, und die Beschreibung von Biodiversitätsschutz, als abstrakter Interessengegenstand, konnte mit dieser Arbeit ein grundlegender Beitrag zur Interessenforschung geleistet werden. Basierend auf den Forschungsergebnissen wurden außerdem evidenzbasierte Gestaltungshypothesen zur Interessenförderung an Biodiversitätsschutz abgeleitet. Die Gestaltungshypothesen bieten eine Grundlage für die Entwicklung von Lernangeboten, die das Interesse am Biodiversitätsschutz in ungeführten free-choice-Zoobesuchen fördern. Damit trägt die Arbeit zugleich zur Weiterentwicklung der Bildungspraxis bei.

Efficient Algorithms for Fractional Load Balancing and Applications to VLSI Global Routing

Fri, 07 Aug 2026 00:00:00 GMT

Efficient Algorithms for Fractional Load Balancing and Applications to VLSI Global Routing Blankenburg, Daniel This thesis studies global routing in chip design, and its generalization, the Load Balancing Problem: finding a minimum-norm element of a structured set built from many "customer" subproblems, each accessible only through a linear minimization oracle.
For the fractional relaxation, we give a new randomized algorithm that samples customers according to a dynamically evolving cost budget and combines non-uniform sampling with a martingale argument to guarantee fast convergence. This requires constructing stable norm approximations via entropic regularization, which are optimal for ordered norms and rely on certain structural properties of a the generalized KL projection to suitable dual spaces. Together these give the first efficient algorithm with a number of oracle calls that is near linear in the number of customers and resources for a broad class of norms beyond the ℓ_∞ norm.
For the integral problem, we show that a simple greedy algorithm, routing each net once in random order, achieves approximation guarantees that asymptotically math those of randomized rounding.
These algorithms are implemented in BonnRouteGlobal, and shown to outperform ts default routing method. The thesis also presents an improved congestion model and a random sub-grid technique that speeds up path search by more than 10x on large instances with almost no notable loss in quality.

The Role of Mco6 in the Biogenesis of the Mitochondrial TOM Complex

Fri, 07 Aug 2026 00:00:00 GMT

The Role of Mco6 in the Biogenesis of the Mitochondrial TOM Complex Chatterjee, Ritwika (noch nicht zugänglich / not yet accessible)

Development and characterization of fusogenic ApoE-liposome complexes for targeted drug delivery to brain endothelial cells

Thu, 06 Aug 2026 00:00:00 GMT

Development and characterization of fusogenic ApoE-liposome complexes for targeted drug delivery to brain endothelial cells Gronemann, Till Benedikt Decay of the cerebral vasculature is a major contributor to age-related cognitive decline, highlighting the need for efficient drug delivery strategies that enable the targeted transport of vasoprotective compounds such as resveratrol (RSV) to the brain endothelium. Against this background, the present study aimed to investigate whether the natural affinity of apolipoprotein E (ApoE) for cationic liposomes can be exploited for the development of brain-specific drug delivery systems. Owing to its central role in cerebral lipid homeostasis, this protein unites pronounced membrane affinity with selective binding to endothelial surface receptors and is thus a promising mediator for the targeted translocation of liposomes into the brain.
Structurally, the system was based on fusogenic liposomes (FL). Unlike conventional liposome formulations, these fuse directly with the cellular plasma membrane and do not rely on endocytic pathways. This property enables rapid and efficient drug delivery while avoiding endosomal degradation. Moreover, the fluid membrane structure of FL is particularly well suited for the transport of hydrophobic compounds such as RSV, as it promotes their intercalation within the lipid bilayer. This results in high partition coefficients and permits the incorporation of significant RSV quantities without compromising liposomal stability and functionality. Quick and reproducible production of homogeneous FL/RSV was achieved via ethanol injection.
The inherent affinity of ApoE for FL was validated by analyzing the composition of the protein corona in blood plasma and investigated further through physicochemical binding studies. Due to extensive and versatile interactions with the lipid membrane, ApoE exhibits exceptionally strong binding to FL, rendering it a persistent element of the protein corona. This creates optimal conditions for protein-mediated targeting, as it facilitates the functionalization of FL/RSV and enhances the stability of the artificial protein corona in the presence of competing protein species. Comprehensive physicochemical characterization and optimization of the ApoE amount used for functionalization resulted in the formation of stable and fully functional protein-liposome complexes.
The potential of these complexes for cerebral drug delivery was confirmed by in vitro and in vivo experiments. Studies on hCMEC/D3 indicated cellular uptake of ApoE-FL/RSV via receptor-mediated docking and subsequent membrane fusion. Moreover, intravenous administration of the complexes in mice led to their accumulation in the cerebral microvasculature, providing additional evidence for the effectiveness of the targeting approach.
Collectively, these findings identify ApoE-functionalized FL as a promising platform for the targeted delivery of RSV to the brain, opening new therapeutic avenues for the treatment of age-related cerebral dysfunctions. Furthermore, the study demonstrates how profound knowledge about the protein corona can guide the rational design of biomimetic targeting strategies that harness the natural affinity of plasma proteins and preserve their functionality by avoiding covalent attachment to the nanomaterial.