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Assessment of food loss among arable crop farmers in Nigeria: A valuation perspective on constraints, practices and outcomes
(2026) Abulude, Ifeoluwa A.
Food loss remains a critical barrier to the sustainable transformation of global food systems, particularly in the Global South, where food insecurity coexists with substantial losses at the primary production stage. Nigeria exemplifies this paradox, ranking low in food availability despite widespread cultivation of staple crops such as maize, rice, and cassava. Addressing food loss is therefore essential for improving food security, optimising resource use, and advancing sustainability goals. However, existing research remains fragmented, with limited attention to the social, institutional, and context-specific processes through which food loss emerges and persists. This thesis addresses these gaps by developing a cumulative analysis that integrates evidence synthesis with qualitative empirical investigation, grounded in the sociology of valuation. It advances the central argument that food loss is not simply the result of technical inefficiencies or isolated constraints, but emerges through the interaction between multidimensional agricultural challenges, farmers’ valuation processes, and the broader socio-material and institutional conditions within which these processes are embedded. The study first establishes that food loss in Nigeria is concentrated at the production and postharvest stages and is shaped by the interaction of natural, social, and material constraints. These include climate variability, pest and disease pressures, limited access to inputs and infrastructure, and weak institutional support systems. However, these constraints do not operate in isolation. Rather, farmers interpret and prioritise them through ongoing processes of valuation, which guide farming decisions. Building on this, the analysis demonstrates that valuation is socially embedded and relational. Farmers assess what is feasible, worthwhile, and manageable within specific contexts shaped by resource limitations, past experiences, and social interactions. These evaluations often lead to the adoption of practices that are rational in the short term but may increase vulnerability to food loss over time. In this way, food loss is not only a consequence of constraints but also of how those constraints are understood and acted upon in practice. The findings further show that these valuation processes are structured by broader agrarian systems, including infrastructures, market arrangements, and institutional conditions that define what is possible within agricultural production and exchange. Limited access to storage, transport, credit, and advisory services constrains farmers’ ability to maintain crop quality and access markets, thereby reinforcing patterns of loss. Food loss thus emerges from the interaction between farmers’ decision-making processes and the structural environments within which those decisions are made. By integrating these insights, the thesis reconceptualises food loss as a socially embedded and systemically produced outcome. It demonstrates that valuation serves as the mechanism linking structural constraints to farming practices and outcomes, explaining how food loss persists despite technological and policy interventions. These findings highlight the need for more integrated approaches to food loss reduction that go beyond technical solutions to engage with farmers’ lived realities, strengthen institutional linkages, and support context-sensitive decision-making. By foregrounding valuation as a central analytical lens, this research contributes to a more nuanced understanding of food loss and provides a foundation for designing policies and interventions that are both effective and sustainable in Nigeria and similar contexts.
Establishing the coral Galaxea fascicularis as a model for symbiosis research
(2026-04) Puntin, Giulia
Coral reefs, among the planet’s most diverse and productive ecosystems, are under increasing threat from climate change and other anthropogenic stressors. Central to coral reef survival is the health and resilience of the coral holobiont—a complex assemblage comprising the coral animal, its symbiotic microalgae (Symbiodiniaceae), and a dynamic microbial community that includes bacteria, archaea, fungi, and viruses. Despite remarkable research progress, key functional roles of holobiont members remain poorly understood, particularly the mechanisms governing coral health under environmental stress and the factors determining susceptibility to holobiont breakdown, which leads to coral bleaching, disease, and mortality. To close these knowledge gaps, this thesis aimed to establish a convenient yet representative new model organism to research coral holobiont dynamics through the experimental manipulation of host-microbial associations. As such, Galaxea fascicularis (Linnaeus, 1767) was identified as an ideal candidate, serving as the “missing link” between established (non-”true coral”) cnidarian models (such as Hydra, Aiptasia, etc.) and actual reef-building corals, and was evaluated for its suitability as a model system. For this purpose, this work: 1) reviewed the state of model organism-based coral research, identifying the scope of G. fascicularis and helping to refine the direction of the experimental chapters of this thesis (Chapter 2); 2) tested the suitability of G. fascicularis to laboratory studies by evaluating its tractability in terms of long-term aquarium maintenance, reproduction in captivity, and symbiosis manipulation (Chapter 3); 3) characterized the bacterial microbiome’s response to chemically-induced bleaching in long-term aquarium reared colonies (Chapter 4); and 4) discussed and outlined future research directions to further enhance the utility of G. fascicularis to address remaining gaps in the understanding of coral holobiont functioning (Chapter 5). The findings support the practical advantages of using G. fascicularis as a model organism. Key achievements include the species demonstrated compatibility with long-term rearing and reproduction in captivity, including compatibility with simplified experimental systems, physiological stress experiments, and symbiosis manipulation. Protocols for producing aposymbiotic fragments through menthol bleaching were refined, enabling reliable production of aposymbiotic fragments for use in experiments, including subsequent re-establishment of symbiosis with novel Symbiodiniaceae strains. Additionally, an initial evaluation of the bacterial microbiome’s response to bleaching revealed insights into how rearing conditions, host identity, and symbiont type influence microbial community composition. Future directions are discussed (Chapter 5) and include refining methodologies for maintaining bleached corals, expanding the range of symbiont strains used for experimental manipulations, and establishing clonal host lines to minimize genetic variability. Further research should also systematically explore holobiont dynamics under varied environmental and rearing conditions to enhance the ecological relevance and reproducibility of findings. These results contribute to a growing body of research aimed at mitigating coral reef decline and highlight the importance of a holobiont-centered approach to coral conservation, where a deeper understanding of microbial roles could inform strategies to enhance coral resilience.
Depression and somatization in Turkish migrants in Germany : the role of migration-related stressors
(2025) Hanewald, Bernd; Hahn, Eric; Ta, Tam Thi Minh; Elguen, Yasemin; Stingl, Markus
Introduction: Migration-related stressors (MRS), such as loss, cultural conflict, and language barriers, are linked to increased psychological distress. This study investigates the impact of MRS on de-pressive symptoms and somatization among Turkish-speaking first-generation migrants in Germany. Method: In a cross-sectional study, 60 psychiatric outpatients completed standardized measures as-sessing MRS, depressive symptoms (BDI-II), and somatization (PHQ-15). Regression analy-ses controlled for age, gender, and socioeconomic status. Results: Higher MRS significantly predicted both depressive symptoms and somatization. Somatic complaints were particularly associated with language difficulties, separation experiences, and intergenerational value conflicts. Conclusion: Findings support the need to integrate cultural humility—defined as clinician self-awareness, openness, and contextual sensitivity—into evidence-based care. Symptom interpretation must consider patients’ migration histories and cultural frameworks. Culturally adapted, person-centered interventions may improve diagnostic accuracy and treatment outcomes for migrant populations.
sORFdb – a database for sORFs, small proteins, and small protein families in bacteria
(2025) Hahnfeld, Julian M.; Schwengers, Oliver; Jelonek, Lukas; Diedrich, Sonja; Cemic, Franz; Goesmann, Alexander
The protein interactome of p65/RELA, the most active subunit of the transcription factor (TF) NF-κB, has not been previously determined in living cells. Using p65-miniTurbo fusion proteins and biotin tagging, we identify >350 RELA interactors from untreated and IL-1α-stimulated cells, including many TFs (47% of all interactors) and >50 epigenetic regulators belonging to different classes of chromatin remodeling complexes. A comparison with the interactomes of two point mutants of p65 reveals that the interactions primarily require intact dimerization rather than DNA-binding properties. A targeted RNAi screen for 38 interactors and subsequent functional transcriptome and bioinformatics studies identify gene regulatory (sub)networks, each controlled by RELA in combination with one of the TFs ZBTB5, GLIS2, TFE3/TFEB, or S100A8/A9. The large, dynamic and versatile high-resolution interactome of RELA and its gene regulatory logics provides a rich resource and a new framework for explaining how RELA cooperativity determines gene expression patterns.
Transmissible Staphylococcus pseudintermedius thwarts neutrophil extracellular trap-driven containment to promote invasive disease
(2025) Haller, Rita; Cai, Yiyang; de Buhr, Nicole; Rieder, Johanna C.; Schlüter, Dirk; Baier, Claas; Rohde, Holger; von Köckritz-Blickwede, Maren; Vital, Marius; Winstel, Volker
Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an emerging zoonotic pathogen that causes a variety of clinical diseases in mammalian hosts. While it frequently causes infections in dogs and other domestic animals, accumulating evidence indicates that zoonotic spillover and cross-species transmission events favour local and invasive S. pseudintermedius infections in humans. However, immuno-evasive maneuvers that shape S. pseudintermedius pathogenicity and survival in diseased hosts remain enigmatic. Powered by multi-tech imaging and a mouse model of bloodstream infection, we illustrate that S. pseudintermedius adopted a virulence mechanism from predominant bacterial pathogens to surmount neutrophilic responses and neutrophil extracellular trap (NET)-mediated killing. Specifically, release of NucB, a thermostable nuclease, helps MRSP coping with the antimicrobial and pathogen-immobilizing properties of NETs and even promotes intra-neutrophil survival upon phagocytosis, thereby contributing to S. pseudintermedius pathogenesis and persistence within hepatic abscesses. Combined with the analysis of genetically distinct human clinical isolates, all of which display nuclease activity and features of resistance to NETosis-induced killing, our data highlight how zoonotic staphylococci overcome innate immune responses and concurrently uncover a mechanism that may exacerbate animal-borne MRSP infections in humans.